updated libirecovery to the latest version from greenpois0n. it at least compiles on osx now, I need to test on other systems

19 files changed, 15095 insertions, 22 deletions

diff --git a/include/libirecovery.h b/include/libirecovery.h
index 2ef1ae3..3220669 100644
--- a/include/libirecovery.h
+++ b/include/libirecovery.h
@@ -1,19 +1,20 @@
 /**
- * iRecovery - Utility for DFU 2.0, WTF and Recovery Mode
- * Copyright (C) 2008 - 2009 westbaer
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+  * GreenPois0n iRecovery - libirecovery.h
+  * Copyright (C) 2010 Chronic-Dev Team
+  * Copyright (C) 2010 Joshua Hill
+  *
+  * This program is free software: you can redistribute it and/or modify
+  * it under the terms of the GNU General Public License as published by
+  * the Free Software Foundation, either version 3 of the License, or
+  * (at your option) any later version.
+  *
+  * This program is distributed in the hope that it will be useful,
+  * but WITHOUT ANY WARRANTY; without even the implied warranty of
+  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  * GNU General Public License for more details.
+  *
+  * You should have received a copy of the GNU General Public License
+  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  **/
 
 #ifndef LIBIRECOVERY_H
@@ -23,10 +24,52 @@
 extern "C" {
 #endif
 
+#ifndef WIN32
 #include <libusb-1.0/libusb.h>
+#else
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+#define sleep(n) Sleep(1000 * n)
+#endif
 
 #define APPLE_VENDOR_ID 0x05AC
 
+#define CPID_UNKNOWN        -1
+#define CPID_IPHONE2G     8900
+#define CPID_IPOD1G       8900
+#define CPID_IPHONE3G     8900
+#define CPID_IPOD2G       8720
+#define CPID_IPHONE3GS    8920
+#define CPID_IPOD3G       8922
+#define CPID_IPAD1G       8930
+#define CPID_IPHONE4      8930
+#define CPID_IPOD4G       8930
+#define CPID_APPLETV2     8930
+
+#define BDID_UNKNOWN        -1
+#define BDID_IPHONE2G        0
+#define BDID_IPOD1G          2
+#define BDID_IPHONE3G        4
+#define BDID_IPOD2G          0
+#define BDID_IPHONE3GS       0
+#define BDID_IPOD3G          2
+#define BDID_IPAD1G          2
+#define BDID_IPHONE4         0
+#define BDID_IPOD4G          8
+#define BDID_APPLETV2       10
+
+#define DEVICE_UNKNOWN      -1
+#define DEVICE_IPHONE2G      0
+#define DEVICE_IPOD1G        1
+#define DEVICE_IPHONE3G      2
+#define DEVICE_IPOD2G        3
+#define DEVICE_IPHONE3GS     4
+#define DEVICE_IPOD3G        5
+#define DEVICE_IPAD1G        6
+#define DEVICE_IPHONE4       7
+#define DEVICE_IPOD4G        8
+#define DEVICE_APPLETV2      9
+
 enum {
 	kRecoveryMode1 = 0x1280,
 	kRecoveryMode2 = 0x1281,
@@ -46,6 +89,8 @@ typedef enum {
 	IRECV_E_USB_STATUS = -7,
 	IRECV_E_USB_INTERFACE = -8,
 	IRECV_E_USB_CONFIGURATION = -9,
+	IRECV_E_PIPE = -10,
+	IRECV_E_TIMEOUT = -11,
 	IRECV_E_UNKNOWN_ERROR = -255
 } irecv_error_t;
 
@@ -67,6 +112,7 @@ typedef struct {
 
 struct irecv_client;
 typedef struct irecv_client* irecv_client_t;
+typedef struct irecv_device* irecv_device_t;
 typedef int(*irecv_event_cb_t)(irecv_client_t client, const irecv_event_t* event);
 
 struct irecv_client {
@@ -75,7 +121,18 @@ struct irecv_client {
 	int interface;
 	int alt_interface;
 	unsigned short mode;
+	char serial[256];
+	
+#ifndef WIN32
 	libusb_device_handle* handle;
+#else
+	HANDLE handle;
+	HANDLE hDFU;
+	HANDLE hIB;
+	LPSTR iBootPath;
+	LPSTR DfuPath;
+#endif
+	
 	irecv_event_cb_t progress_callback;
 	irecv_event_cb_t received_callback;
 	irecv_event_cb_t connected_callback;
@@ -84,26 +141,75 @@ struct irecv_client {
 	irecv_event_cb_t disconnected_callback;
 };
 
+struct irecv_device {
+	int index;
+	const char* product;
+	const char* model;
+	unsigned int board_id;
+	unsigned int chip_id;
+	const char* url;
+};
+
+static struct irecv_device irecv_devices[] = {
+	{  0, "iPhone1,1",  "m68ap",  0,  8900,
+	"http://appldnld.apple.com.edgesuite.net/content.info.apple.com/iPhone/061-7481.20100202.4orot/iPhone1,1_3.1.3_7E18_Restore.ipsw" },
+	{  1, "iPod1,1",    "n45ap",  2,  8900,
+	NULL },
+	{  2, "iPhone1,2",  "n82ap",  4,  8900,
+	"http://appldnld.apple.com/iPhone4/061-7932.20100908.3fgt5/iPhone1,2_4.1_8B117_Restore.ipsw" },
+	{  3, "iPod2,1",    "n72ap",  0,  8720,
+	"http://appldnld.apple.com/iPhone4/061-7937.20100908.ghj4f/iPod2,1_4.1_8B117_Restore.ipsw" },
+	{  4, "iPhone2,1",  "n88ap",  0,  8920,
+	"http://appldnld.apple.com/iPhone4/061-7938.20100908.F3rCk/iPhone2,1_4.1_8B117_Restore.ipsw" },
+	{  5, "iPod3,1",    "n18ap",  2,  8922,
+	"http://appldnld.apple.com/iPhone4/061-7941.20100908.sV9KE/iPod3,1_4.1_8B117_Restore.ipsw" },
+	{  6, "iPad1,1",    "k48ap",  2,  8930,
+	"http://appldnld.apple.com/iPad/061-8801.20100811.CvfR5/iPad1,1_3.2.2_7B500_Restore.ipsw" },
+	{  7, "iPhone3,1",  "n90ap",  0,  8930,
+	"http://appldnld.apple.com/iPhone4/061-7939.20100908.Lcyg3/iPhone3,1_4.1_8B117_Restore.ipsw" },
+	{  8, "iPod4,1",    "n81ap",  8,  8930,
+	"http://appldnld.apple.com/iPhone4/061-8490.20100901.hyjtR/iPod4,1_4.1_8B117_Restore.ipsw" },
+	{  9, "AppleTV2,1", "k66ap", 10,  8930,
+	"http://appldnld.apple.com/AppleTV/061-8940.20100926.Tvtnz/AppleTV2,1_4.1_8M89_Restore.ipsw" },
+	{ -1,  NULL,        NULL,   -1,    -1,
+	NULL }
+};
+
 void irecv_set_debug_level(int level);
 const char* irecv_strerror(irecv_error_t error);
+irecv_error_t irecv_open_attempts(irecv_client_t* pclient, int attempts);
 irecv_error_t irecv_open(irecv_client_t* client);
 irecv_error_t irecv_reset(irecv_client_t client);
 irecv_error_t irecv_close(irecv_client_t client);
 irecv_error_t irecv_receive(irecv_client_t client);
 irecv_error_t irecv_send_exploit(irecv_client_t client);
-irecv_error_t irecv_get_cpid(irecv_client_t client, unsigned int* cpid);
-irecv_error_t irecv_get_bdid(irecv_client_t client, unsigned int* bdid);
-irecv_error_t irecv_send_file(irecv_client_t client, const char* filename);
-irecv_error_t irecv_get_ecid(irecv_client_t client, unsigned long long* ecid);
 irecv_error_t irecv_execute_script(irecv_client_t client, const char* filename);
-irecv_error_t irecv_send_command(irecv_client_t client, unsigned char* command);
 irecv_error_t irecv_set_configuration(irecv_client_t client, int configuration);
+
+irecv_error_t irecv_event_subscribe(irecv_client_t client, irecv_event_type type, irecv_event_cb_t callback, void *user_data);
 irecv_error_t irecv_event_unsubscribe(irecv_client_t client, irecv_event_type type);
+
+irecv_error_t irecv_send_file(irecv_client_t client, const char* filename, int dfuNotifyFinished);
+irecv_error_t irecv_send_command(irecv_client_t client, char* command);
+irecv_error_t irecv_send_buffer(irecv_client_t client, unsigned char* buffer, unsigned long length, int dfuNotifyFinished);
+
+irecv_error_t irecv_saveenv(irecv_client_t client);
+irecv_error_t irecv_getret(irecv_client_t client, unsigned int* value);
 irecv_error_t irecv_getenv(irecv_client_t client, const char* variable, char** value);
 irecv_error_t irecv_setenv(irecv_client_t client, const char* variable, const char* value);
 irecv_error_t irecv_set_interface(irecv_client_t client, int interface, int alt_interface);
-irecv_error_t irecv_send_buffer(irecv_client_t client, unsigned char* buffer, unsigned int length);
-irecv_error_t irecv_event_subscribe(irecv_client_t client, irecv_event_type type, irecv_event_cb_t callback, void *user_data);
+irecv_error_t irecv_get_cpid(irecv_client_t client, unsigned int* cpid);
+irecv_error_t irecv_get_bdid(irecv_client_t client, unsigned int* bdid);
+irecv_error_t irecv_get_ecid(irecv_client_t client, unsigned long long* ecid);
+void irecv_hexdump(unsigned char* buf, unsigned int len, unsigned int addr);
+
+void irecv_init();
+void irecv_exit();
+irecv_client_t irecv_reconnect(irecv_client_t client, int initial_pause);
+irecv_error_t irecv_reset_counters(irecv_client_t client);
+irecv_error_t irecv_finish_transfer(irecv_client_t client);
+irecv_error_t irecv_recv_buffer(irecv_client_t client, char* buffer, unsigned long length);
+irecv_error_t irecv_get_device(irecv_client_t client, irecv_device_t* device);
 
 #ifdef __cplusplus
 }
diff --git a/include/libusb-1.0/config.h b/include/libusb-1.0/config.h
new file mode 100644
index 0000000..643d4af
--- /dev/null
+++ b/include/libusb-1.0/config.h
@@ -0,0 +1,105 @@
+/* config.h.  Generated from config.h.in by configure.  */
+/* config.h.in.  Generated from configure.ac by autoheader.  */
+
+/* Default visibility */
+#define DEFAULT_VISIBILITY __attribute__((visibility("default")))
+
+/* Debug message logging */
+/* #undef ENABLE_DEBUG_LOGGING */
+
+/* Message logging */
+#define ENABLE_LOGGING 1
+
+/* Define to 1 if you have the <dlfcn.h> header file. */
+#define HAVE_DLFCN_H 1
+
+/* Define to 1 if you have the <inttypes.h> header file. */
+#define HAVE_INTTYPES_H 1
+
+/* Define to 1 if you have the <memory.h> header file. */
+#define HAVE_MEMORY_H 1
+
+/* Define to 1 if you have the <stdint.h> header file. */
+#define HAVE_STDINT_H 1
+
+/* Define to 1 if you have the <stdlib.h> header file. */
+#define HAVE_STDLIB_H 1
+
+/* Define to 1 if you have the <strings.h> header file. */
+#define HAVE_STRINGS_H 1
+
+/* Define to 1 if you have the <string.h> header file. */
+#define HAVE_STRING_H 1
+
+/* Define to 1 if the system has the type `struct timespec'. */
+#define HAVE_STRUCT_TIMESPEC 1
+
+/* Define to 1 if you have the <sys/stat.h> header file. */
+#define HAVE_SYS_STAT_H 1
+
+/* Define to 1 if you have the <sys/time.h> header file. */
+#define HAVE_SYS_TIME_H 1
+
+/* Define to 1 if you have the <sys/types.h> header file. */
+#define HAVE_SYS_TYPES_H 1
+
+/* Define to 1 if you have the <unistd.h> header file. */
+#define HAVE_UNISTD_H 1
+
+/* Define to the sub-directory in which libtool stores uninstalled libraries.
+   */
+#define LT_OBJDIR ".libs/"
+
+/* Define to 1 if your C compiler doesn't accept -c and -o together. */
+/* #undef NO_MINUS_C_MINUS_O */
+
+/* Darwin backend */
+#define OS_DARWIN 
+
+/* Linux backend */
+/* #undef OS_LINUX */
+
+/* Windows backend */
+/* #undef OS_WINDOWS */
+
+/* Name of package */
+#define PACKAGE "libusb"
+
+/* Define to the address where bug reports for this package should be sent. */
+#define PACKAGE_BUGREPORT "libusb-devel@lists.sourceforge.net"
+
+/* Define to the full name of this package. */
+#define PACKAGE_NAME "libusb"
+
+/* Define to the full name and version of this package. */
+#define PACKAGE_STRING "libusb 1.0.8"
+
+/* Define to the one symbol short name of this package. */
+#define PACKAGE_TARNAME "libusb"
+
+/* Define to the version of this package. */
+#define PACKAGE_VERSION "1.0.8"
+
+/* Define to 1 if you have the ANSI C header files. */
+#define STDC_HEADERS 1
+
+/* Use Posix Threads */
+#define THREADS_POSIX 
+
+/* Backend handles timeout */
+#define USBI_OS_HANDLES_TIMEOUT 
+
+/* timerfd headers available */
+/* #undef USBI_TIMERFD_AVAILABLE */
+
+/* Version number of package */
+#define VERSION "1.0.8"
+
+/* Use GNU extensions */
+#define _GNU_SOURCE 
+
+/* Define to `__inline__' or `__inline' if that's what the C compiler
+   calls it, or to nothing if 'inline' is not supported under any name.  */
+#ifndef __cplusplus
+/* #undef inline */
+#endif
diff --git a/include/libusb-1.0/libusb.h b/include/libusb-1.0/libusb.h
new file mode 100644
index 0000000..8dc3362
--- /dev/null
+++ b/include/libusb-1.0/libusb.h
@@ -0,0 +1,1322 @@
+/*
+ * Public libusb header file
+ * Copyright (C) 2007-2008 Daniel Drake <dsd@gentoo.org>
+ * Copyright (c) 2001 Johannes Erdfelt <johannes@erdfelt.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef __LIBUSB_H__
+#define __LIBUSB_H__
+
+/* MSVC doesn't like inline, but does accept __inline ?? */
+#ifdef _MSC_VER
+#define inline __inline
+#endif
+
+#include <stdint.h>
+#include <sys/types.h>
+#include <time.h>
+#include <limits.h>
+
+#if defined(__linux) || defined(__APPLE__) || defined(__CYGWIN__)
+#include <sys/time.h>
+#endif
+
+/* 'interface' might be defined as a macro on Windows, so we need to
+ * undefine it so as not to break the current libusb API, because
+ * libusb_config_descriptor has an 'interface' member
+ * As this can be problematic if you include windows.h after libusb.h
+ * in your sources, we force windows.h to be included first. */
+#if defined(_WIN32) || defined(__CYGWIN__)
+#include <windows.h>
+#if defined(interface)
+#undef interface
+#endif
+#endif
+
+/** \def LIBUSB_CALL
+ * \ingroup misc
+ * libusb's Windows calling convention.
+ *
+ * Under Windows, the selection of available compilers and configurations
+ * means that, unlike other platforms, there is not <em>one true calling
+ * convention</em> (calling convention: the manner in which parameters are
+ * passed to funcions in the generated assembly code).
+ *
+ * Matching the Windows API itself, libusb uses the WINAPI convention (which
+ * translates to the <tt>stdcall</tt> convention) and guarantees that the
+ * library is compiled in this way. The public header file also includes
+ * appropriate annotations so that your own software will use the right
+ * convention, even if another convention is being used by default within
+ * your codebase.
+ *
+ * The one consideration that you must apply in your software is to mark
+ * all functions which you use as libusb callbacks with this LIBUSB_CALL
+ * annotation, so that they too get compiled for the correct calling
+ * convention.
+ *
+ * On non-Windows operating systems, this macro is defined as nothing. This
+ * means that you can apply it to your code without worrying about
+ * cross-platform compatibility.
+ */
+/* LIBUSB_CALL must be defined on both definition and declaration of libusb
+ * functions. You'd think that declaration would be enough, but cygwin will
+ * complain about conflicting types unless both are marked this way.
+ * The placement of this macro is important too; it must appear after the
+ * return type, before the function name. See internal documentation for
+ * API_EXPORTED.
+ */
+#if defined(_WIN32) || defined(__CYGWIN__)
+#define LIBUSB_CALL WINAPI
+#else
+#define LIBUSB_CALL
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** \def libusb_cpu_to_le16
+ * \ingroup misc
+ * Convert a 16-bit value from host-endian to little-endian format. On
+ * little endian systems, this function does nothing. On big endian systems,
+ * the bytes are swapped.
+ * \param x the host-endian value to convert
+ * \returns the value in little-endian byte order
+ */
+static inline uint16_t libusb_cpu_to_le16(const uint16_t x)
+{
+	union {
+		uint8_t  b8[2];
+		uint16_t b16;
+	} _tmp;
+	_tmp.b8[1] = x >> 8;
+	_tmp.b8[0] = x & 0xff;
+	return _tmp.b16;
+}
+
+/** \def libusb_le16_to_cpu
+ * \ingroup misc
+ * Convert a 16-bit value from little-endian to host-endian format. On
+ * little endian systems, this function does nothing. On big endian systems,
+ * the bytes are swapped.
+ * \param x the little-endian value to convert
+ * \returns the value in host-endian byte order
+ */
+#define libusb_le16_to_cpu libusb_cpu_to_le16
+
+/* standard USB stuff */
+
+/** \ingroup desc
+ * Device and/or Interface Class codes */
+enum libusb_class_code {
+	/** In the context of a \ref libusb_device_descriptor "device descriptor",
+	 * this bDeviceClass value indicates that each interface specifies its
+	 * own class information and all interfaces operate independently.
+	 */
+	LIBUSB_CLASS_PER_INTERFACE = 0,
+
+	/** Audio class */
+	LIBUSB_CLASS_AUDIO = 1,
+
+	/** Communications class */
+	LIBUSB_CLASS_COMM = 2,
+
+	/** Human Interface Device class */
+	LIBUSB_CLASS_HID = 3,
+
+	/** Printer dclass */
+	LIBUSB_CLASS_PRINTER = 7,
+
+	/** Picture transfer protocol class */
+	LIBUSB_CLASS_PTP = 6,
+
+	/** Mass storage class */
+	LIBUSB_CLASS_MASS_STORAGE = 8,
+
+	/** Hub class */
+	LIBUSB_CLASS_HUB = 9,
+
+	/** Data class */
+	LIBUSB_CLASS_DATA = 10,
+
+	/** Wireless class */
+	LIBUSB_CLASS_WIRELESS = 0xe0,
+
+	/** Application class */
+	LIBUSB_CLASS_APPLICATION = 0xfe,
+
+	/** Class is vendor-specific */
+	LIBUSB_CLASS_VENDOR_SPEC = 0xff
+};
+
+/** \ingroup desc
+ * Descriptor types as defined by the USB specification. */
+enum libusb_descriptor_type {
+	/** Device descriptor. See libusb_device_descriptor. */
+	LIBUSB_DT_DEVICE = 0x01,
+
+	/** Configuration descriptor. See libusb_config_descriptor. */
+	LIBUSB_DT_CONFIG = 0x02,
+
+	/** String descriptor */
+	LIBUSB_DT_STRING = 0x03,
+
+	/** Interface descriptor. See libusb_interface_descriptor. */
+	LIBUSB_DT_INTERFACE = 0x04,
+
+	/** Endpoint descriptor. See libusb_endpoint_descriptor. */
+	LIBUSB_DT_ENDPOINT = 0x05,
+
+	/** HID descriptor */
+	LIBUSB_DT_HID = 0x21,
+
+	/** HID report descriptor */
+	LIBUSB_DT_REPORT = 0x22,
+
+	/** Physical descriptor */
+	LIBUSB_DT_PHYSICAL = 0x23,
+
+	/** Hub descriptor */
+	LIBUSB_DT_HUB = 0x29
+};
+
+/* Descriptor sizes per descriptor type */
+#define LIBUSB_DT_DEVICE_SIZE			18
+#define LIBUSB_DT_CONFIG_SIZE			9
+#define LIBUSB_DT_INTERFACE_SIZE		9
+#define LIBUSB_DT_ENDPOINT_SIZE		7
+#define LIBUSB_DT_ENDPOINT_AUDIO_SIZE	9	/* Audio extension */
+#define LIBUSB_DT_HUB_NONVAR_SIZE		7
+
+#define LIBUSB_ENDPOINT_ADDRESS_MASK	0x0f    /* in bEndpointAddress */
+#define LIBUSB_ENDPOINT_DIR_MASK		0x80
+
+/** \ingroup desc
+ * Endpoint direction. Values for bit 7 of the
+ * \ref libusb_endpoint_descriptor::bEndpointAddress "endpoint address" scheme.
+ */
+enum libusb_endpoint_direction {
+	/** In: device-to-host */
+	LIBUSB_ENDPOINT_IN = 0x80,
+
+	/** Out: host-to-device */
+	LIBUSB_ENDPOINT_OUT = 0x00
+};
+
+#define LIBUSB_TRANSFER_TYPE_MASK			0x03    /* in bmAttributes */
+
+/** \ingroup desc
+ * Endpoint transfer type. Values for bits 0:1 of the
+ * \ref libusb_endpoint_descriptor::bmAttributes "endpoint attributes" field.
+ */
+enum libusb_transfer_type {
+	/** Control endpoint */
+	LIBUSB_TRANSFER_TYPE_CONTROL = 0,
+
+	/** Isochronous endpoint */
+	LIBUSB_TRANSFER_TYPE_ISOCHRONOUS = 1,
+
+	/** Bulk endpoint */
+	LIBUSB_TRANSFER_TYPE_BULK = 2,
+
+	/** Interrupt endpoint */
+	LIBUSB_TRANSFER_TYPE_INTERRUPT = 3
+};
+
+/** \ingroup misc
+ * Standard requests, as defined in table 9-3 of the USB2 specifications */
+enum libusb_standard_request {
+	/** Request status of the specific recipient */
+	LIBUSB_REQUEST_GET_STATUS = 0x00,
+
+	/** Clear or disable a specific feature */
+	LIBUSB_REQUEST_CLEAR_FEATURE = 0x01,
+
+	/* 0x02 is reserved */
+
+	/** Set or enable a specific feature */
+	LIBUSB_REQUEST_SET_FEATURE = 0x03,
+
+	/* 0x04 is reserved */
+
+	/** Set device address for all future accesses */
+	LIBUSB_REQUEST_SET_ADDRESS = 0x05,
+
+	/** Get the specified descriptor */
+	LIBUSB_REQUEST_GET_DESCRIPTOR = 0x06,
+
+	/** Used to update existing descriptors or add new descriptors */
+	LIBUSB_REQUEST_SET_DESCRIPTOR = 0x07,
+
+	/** Get the current device configuration value */
+	LIBUSB_REQUEST_GET_CONFIGURATION = 0x08,
+
+	/** Set device configuration */
+	LIBUSB_REQUEST_SET_CONFIGURATION = 0x09,
+
+	/** Return the selected alternate setting for the specified interface */
+	LIBUSB_REQUEST_GET_INTERFACE = 0x0A,
+
+	/** Select an alternate interface for the specified interface */
+	LIBUSB_REQUEST_SET_INTERFACE = 0x0B,
+
+	/** Set then report an endpoint's synchronization frame */
+	LIBUSB_REQUEST_SYNCH_FRAME = 0x0C
+};
+
+/** \ingroup misc
+ * Request type bits of the
+ * \ref libusb_control_setup::bmRequestType "bmRequestType" field in control
+ * transfers. */
+enum libusb_request_type {
+	/** Standard */
+	LIBUSB_REQUEST_TYPE_STANDARD = (0x00 << 5),
+
+	/** Class */
+	LIBUSB_REQUEST_TYPE_CLASS = (0x01 << 5),
+
+	/** Vendor */
+	LIBUSB_REQUEST_TYPE_VENDOR = (0x02 << 5),
+
+	/** Reserved */
+	LIBUSB_REQUEST_TYPE_RESERVED = (0x03 << 5)
+};
+
+/** \ingroup misc
+ * Recipient bits of the
+ * \ref libusb_control_setup::bmRequestType "bmRequestType" field in control
+ * transfers. Values 4 through 31 are reserved. */
+enum libusb_request_recipient {
+	/** Device */
+	LIBUSB_RECIPIENT_DEVICE = 0x00,
+
+	/** Interface */
+	LIBUSB_RECIPIENT_INTERFACE = 0x01,
+
+	/** Endpoint */
+	LIBUSB_RECIPIENT_ENDPOINT = 0x02,
+
+	/** Other */
+	LIBUSB_RECIPIENT_OTHER = 0x03
+};
+
+#define LIBUSB_ISO_SYNC_TYPE_MASK		0x0C
+
+/** \ingroup desc
+ * Synchronization type for isochronous endpoints. Values for bits 2:3 of the
+ * \ref libusb_endpoint_descriptor::bmAttributes "bmAttributes" field in
+ * libusb_endpoint_descriptor.
+ */
+enum libusb_iso_sync_type {
+	/** No synchronization */
+	LIBUSB_ISO_SYNC_TYPE_NONE = 0,
+
+	/** Asynchronous */
+	LIBUSB_ISO_SYNC_TYPE_ASYNC = 1,
+
+	/** Adaptive */
+	LIBUSB_ISO_SYNC_TYPE_ADAPTIVE = 2,
+
+	/** Synchronous */
+	LIBUSB_ISO_SYNC_TYPE_SYNC = 3
+};
+
+#define LIBUSB_ISO_USAGE_TYPE_MASK 0x30
+
+/** \ingroup desc
+ * Usage type for isochronous endpoints. Values for bits 4:5 of the
+ * \ref libusb_endpoint_descriptor::bmAttributes "bmAttributes" field in
+ * libusb_endpoint_descriptor.
+ */
+enum libusb_iso_usage_type {
+	/** Data endpoint */
+	LIBUSB_ISO_USAGE_TYPE_DATA = 0,
+
+	/** Feedback endpoint */
+	LIBUSB_ISO_USAGE_TYPE_FEEDBACK = 1,
+
+	/** Implicit feedback Data endpoint */
+	LIBUSB_ISO_USAGE_TYPE_IMPLICIT = 2
+};
+
+/** \ingroup desc
+ * A structure representing the standard USB device descriptor. This
+ * descriptor is documented in section 9.6.1 of the USB 2.0 specification.
+ * All multiple-byte fields are represented in host-endian format.
+ */
+struct libusb_device_descriptor {
+	/** Size of this descriptor (in bytes) */
+	uint8_t  bLength;
+
+	/** Descriptor type. Will have value
+	 * \ref libusb_descriptor_type::LIBUSB_DT_DEVICE LIBUSB_DT_DEVICE in this
+	 * context. */
+	uint8_t  bDescriptorType;
+
+	/** USB specification release number in binary-coded decimal. A value of
+	 * 0x0200 indicates USB 2.0, 0x0110 indicates USB 1.1, etc. */
+	uint16_t bcdUSB;
+
+	/** USB-IF class code for the device. See \ref libusb_class_code. */
+	uint8_t  bDeviceClass;
+
+	/** USB-IF subclass code for the device, qualified by the bDeviceClass
+	 * value */
+	uint8_t  bDeviceSubClass;
+
+	/** USB-IF protocol code for the device, qualified by the bDeviceClass and
+	 * bDeviceSubClass values */
+	uint8_t  bDeviceProtocol;
+
+	/** Maximum packet size for endpoint 0 */
+	uint8_t  bMaxPacketSize0;
+
+	/** USB-IF vendor ID */
+	uint16_t idVendor;
+
+	/** USB-IF product ID */
+	uint16_t idProduct;
+
+	/** Device release number in binary-coded decimal */
+	uint16_t bcdDevice;
+
+	/** Index of string descriptor describing manufacturer */
+	uint8_t  iManufacturer;
+
+	/** Index of string descriptor describing product */
+	uint8_t  iProduct;
+
+	/** Index of string descriptor containing device serial number */
+	uint8_t  iSerialNumber;
+
+	/** Number of possible configurations */
+	uint8_t  bNumConfigurations;
+};
+
+/** \ingroup desc
+ * A structure representing the standard USB endpoint descriptor. This
+ * descriptor is documented in section 9.6.3 of the USB 2.0 specification.
+ * All multiple-byte fields are represented in host-endian format.
+ */
+struct libusb_endpoint_descriptor {
+	/** Size of this descriptor (in bytes) */
+	uint8_t  bLength;
+
+	/** Descriptor type. Will have value
+	 * \ref libusb_descriptor_type::LIBUSB_DT_ENDPOINT LIBUSB_DT_ENDPOINT in
+	 * this context. */
+	uint8_t  bDescriptorType;
+
+	/** The address of the endpoint described by this descriptor. Bits 0:3 are
+	 * the endpoint number. Bits 4:6 are reserved. Bit 7 indicates direction,
+	 * see \ref libusb_endpoint_direction.
+	 */
+	uint8_t  bEndpointAddress;
+
+	/** Attributes which apply to the endpoint when it is configured using
+	 * the bConfigurationValue. Bits 0:1 determine the transfer type and
+	 * correspond to \ref libusb_transfer_type. Bits 2:3 are only used for
+	 * isochronous endpoints and correspond to \ref libusb_iso_sync_type.
+	 * Bits 4:5 are also only used for isochronous endpoints and correspond to
+	 * \ref libusb_iso_usage_type. Bits 6:7 are reserved.
+	 */
+	uint8_t  bmAttributes;
+
+	/** Maximum packet size this endpoint is capable of sending/receiving. */
+	uint16_t wMaxPacketSize;
+
+	/** Interval for polling endpoint for data transfers. */
+	uint8_t  bInterval;
+
+	/** For audio devices only: the rate at which synchronization feedback
+	 * is provided. */
+	uint8_t  bRefresh;
+
+	/** For audio devices only: the address if the synch endpoint */
+	uint8_t  bSynchAddress;
+
+	/** Extra descriptors. If libusb encounters unknown endpoint descriptors,
+	 * it will store them here, should you wish to parse them. */
+	const unsigned char *extra;
+
+	/** Length of the extra descriptors, in bytes. */
+	int extra_length;
+};
+
+/** \ingroup desc
+ * A structure representing the standard USB interface descriptor. This
+ * descriptor is documented in section 9.6.5 of the USB 2.0 specification.
+ * All multiple-byte fields are represented in host-endian format.
+ */
+struct libusb_interface_descriptor {
+	/** Size of this descriptor (in bytes) */
+	uint8_t  bLength;
+
+	/** Descriptor type. Will have value
+	 * \ref libusb_descriptor_type::LIBUSB_DT_INTERFACE LIBUSB_DT_INTERFACE
+	 * in this context. */
+	uint8_t  bDescriptorType;
+
+	/** Number of this interface */
+	uint8_t  bInterfaceNumber;
+
+	/** Value used to select this alternate setting for this interface */
+	uint8_t  bAlternateSetting;
+
+	/** Number of endpoints used by this interface (excluding the control
+	 * endpoint). */
+	uint8_t  bNumEndpoints;
+
+	/** USB-IF class code for this interface. See \ref libusb_class_code. */
+	uint8_t  bInterfaceClass;
+
+	/** USB-IF subclass code for this interface, qualified by the
+	 * bInterfaceClass value */
+	uint8_t  bInterfaceSubClass;
+
+	/** USB-IF protocol code for this interface, qualified by the
+	 * bInterfaceClass and bInterfaceSubClass values */
+	uint8_t  bInterfaceProtocol;
+
+	/** Index of string descriptor describing this interface */
+	uint8_t  iInterface;
+
+	/** Array of endpoint descriptors. This length of this array is determined
+	 * by the bNumEndpoints field. */
+	const struct libusb_endpoint_descriptor *endpoint;
+
+	/** Extra descriptors. If libusb encounters unknown interface descriptors,
+	 * it will store them here, should you wish to parse them. */
+	const unsigned char *extra;
+
+	/** Length of the extra descriptors, in bytes. */
+	int extra_length;
+};
+
+/** \ingroup desc
+ * A collection of alternate settings for a particular USB interface.
+ */
+struct libusb_interface {
+	/** Array of interface descriptors. The length of this array is determined
+	 * by the num_altsetting field. */
+	const struct libusb_interface_descriptor *altsetting;
+
+	/** The number of alternate settings that belong to this interface */
+	int num_altsetting;
+};
+
+/** \ingroup desc
+ * A structure representing the standard USB configuration descriptor. This
+ * descriptor is documented in section 9.6.3 of the USB 2.0 specification.
+ * All multiple-byte fields are represented in host-endian format.
+ */
+struct libusb_config_descriptor {
+	/** Size of this descriptor (in bytes) */
+	uint8_t  bLength;
+
+	/** Descriptor type. Will have value
+	 * \ref libusb_descriptor_type::LIBUSB_DT_CONFIG LIBUSB_DT_CONFIG
+	 * in this context. */
+	uint8_t  bDescriptorType;
+
+	/** Total length of data returned for this configuration */
+	uint16_t wTotalLength;
+
+	/** Number of interfaces supported by this configuration */
+	uint8_t  bNumInterfaces;
+
+	/** Identifier value for this configuration */
+	uint8_t  bConfigurationValue;
+
+	/** Index of string descriptor describing this configuration */
+	uint8_t  iConfiguration;
+
+	/** Configuration characteristics */
+	uint8_t  bmAttributes;
+
+	/** Maximum power consumption of the USB device from this bus in this
+	 * configuration when the device is fully opreation. Expressed in units
+	 * of 2 mA. */
+	uint8_t  MaxPower;
+
+	/** Array of interfaces supported by this configuration. The length of
+	 * this array is determined by the bNumInterfaces field. */
+	const struct libusb_interface *interface;
+
+	/** Extra descriptors. If libusb encounters unknown configuration
+	 * descriptors, it will store them here, should you wish to parse them. */
+	const unsigned char *extra;
+
+	/** Length of the extra descriptors, in bytes. */
+	int extra_length;
+};
+
+/** \ingroup asyncio
+ * Setup packet for control transfers. */
+struct libusb_control_setup {
+	/** Request type. Bits 0:4 determine recipient, see
+	 * \ref libusb_request_recipient. Bits 5:6 determine type, see
+	 * \ref libusb_request_type. Bit 7 determines data transfer direction, see
+	 * \ref libusb_endpoint_direction.
+	 */
+	uint8_t  bmRequestType;
+
+	/** Request. If the type bits of bmRequestType are equal to
+	 * \ref libusb_request_type::LIBUSB_REQUEST_TYPE_STANDARD
+	 * "LIBUSB_REQUEST_TYPE_STANDARD" then this field refers to
+	 * \ref libusb_standard_request. For other cases, use of this field is
+	 * application-specific. */
+	uint8_t  bRequest;
+
+	/** Value. Varies according to request */
+	uint16_t wValue;
+
+	/** Index. Varies according to request, typically used to pass an index
+	 * or offset */
+	uint16_t wIndex;
+
+	/** Number of bytes to transfer */
+	uint16_t wLength;
+};
+
+#define LIBUSB_CONTROL_SETUP_SIZE (sizeof(struct libusb_control_setup))
+
+/* libusb */
+
+struct libusb_context;
+struct libusb_device;
+struct libusb_device_handle;
+
+/** \ingroup lib
+ * Structure representing a libusb session. The concept of individual libusb
+ * sessions allows for your program to use two libraries (or dynamically
+ * load two modules) which both independently use libusb. This will prevent
+ * interference between the individual libusb users - for example
+ * libusb_set_debug() will not affect the other user of the library, and
+ * libusb_exit() will not destroy resources that the other user is still
+ * using.
+ *
+ * Sessions are created by libusb_init() and destroyed through libusb_exit().
+ * If your application is guaranteed to only ever include a single libusb
+ * user (i.e. you), you do not have to worry about contexts: pass NULL in
+ * every function call where a context is required. The default context
+ * will be used.
+ *
+ * For more information, see \ref contexts.
+ */
+typedef struct libusb_context libusb_context;
+
+/** \ingroup dev
+ * Structure representing a USB device detected on the system. This is an
+ * opaque type for which you are only ever provided with a pointer, usually
+ * originating from libusb_get_device_list().
+ *
+ * Certain operations can be performed on a device, but in order to do any
+ * I/O you will have to first obtain a device handle using libusb_open().
+ *
+ * Devices are reference counted with libusb_device_ref() and
+ * libusb_device_unref(), and are freed when the reference count reaches 0.
+ * New devices presented by libusb_get_device_list() have a reference count of
+ * 1, and libusb_free_device_list() can optionally decrease the reference count
+ * on all devices in the list. libusb_open() adds another reference which is
+ * later destroyed by libusb_close().
+ */
+typedef struct libusb_device libusb_device;
+
+
+/** \ingroup dev
+ * Structure representing a handle on a USB device. This is an opaque type for
+ * which you are only ever provided with a pointer, usually originating from
+ * libusb_open().
+ *
+ * A device handle is used to perform I/O and other operations. When finished
+ * with a device handle, you should call libusb_close().
+ */
+typedef struct libusb_device_handle libusb_device_handle;
+
+/** \ingroup misc
+ * Error codes. Most libusb functions return 0 on success or one of these
+ * codes on failure.
+ * You can use libusb_strerror() to retrieve a short string description of
+ * a libusb_error enumeration value.
+ */
+enum libusb_error {
+	/** Success (no error) */
+	LIBUSB_SUCCESS = 0,
+
+	/** Input/output error */
+	LIBUSB_ERROR_IO = -1,
+
+	/** Invalid parameter */
+	LIBUSB_ERROR_INVALID_PARAM = -2,
+
+	/** Access denied (insufficient permissions) */
+	LIBUSB_ERROR_ACCESS = -3,
+
+	/** No such device (it may have been disconnected) */
+	LIBUSB_ERROR_NO_DEVICE = -4,
+
+	/** Entity not found */
+	LIBUSB_ERROR_NOT_FOUND = -5,
+
+	/** Resource busy */
+	LIBUSB_ERROR_BUSY = -6,
+
+	/** Operation timed out */
+	LIBUSB_ERROR_TIMEOUT = -7,
+
+	/** Overflow */
+	LIBUSB_ERROR_OVERFLOW = -8,
+
+	/** Pipe error */
+	LIBUSB_ERROR_PIPE = -9,
+
+	/** System call interrupted (perhaps due to signal) */
+	LIBUSB_ERROR_INTERRUPTED = -10,
+
+	/** Insufficient memory */
+	LIBUSB_ERROR_NO_MEM = -11,
+
+	/** Operation not supported or unimplemented on this platform */
+	LIBUSB_ERROR_NOT_SUPPORTED = -12,
+
+	/** Other error */
+	LIBUSB_ERROR_OTHER = -99
+
+	/* IMPORTANT: when adding new values to this enum, remember to
+	   update the libusb_strerror() function implementation! */
+};
+
+/** \ingroup asyncio
+ * Transfer status codes */
+enum libusb_transfer_status {
+	/** Transfer completed without error. Note that this does not indicate
+	 * that the entire amount of requested data was transferred. */
+	LIBUSB_TRANSFER_COMPLETED,
+
+	/** Transfer failed */
+	LIBUSB_TRANSFER_ERROR,
+
+	/** Transfer timed out */
+	LIBUSB_TRANSFER_TIMED_OUT,
+
+	/** Transfer was cancelled */
+	LIBUSB_TRANSFER_CANCELLED,
+
+	/** For bulk/interrupt endpoints: halt condition detected (endpoint
+	 * stalled). For control endpoints: control request not supported. */
+	LIBUSB_TRANSFER_STALL,
+
+	/** Device was disconnected */
+	LIBUSB_TRANSFER_NO_DEVICE,
+
+	/** Device sent more data than requested */
+	LIBUSB_TRANSFER_OVERFLOW
+};
+
+/** \ingroup asyncio
+ * libusb_transfer.flags values */
+enum libusb_transfer_flags {
+	/** Report short frames as errors */
+	LIBUSB_TRANSFER_SHORT_NOT_OK = 1<<0,
+
+	/** Automatically free() transfer buffer during libusb_free_transfer() */
+	LIBUSB_TRANSFER_FREE_BUFFER = 1<<1,
+
+	/** Automatically call libusb_free_transfer() after callback returns.
+	 * If this flag is set, it is illegal to call libusb_free_transfer()
+	 * from your transfer callback, as this will result in a double-free
+	 * when this flag is acted upon. */
+	LIBUSB_TRANSFER_FREE_TRANSFER = 1<<2
+};
+
+/** \ingroup asyncio
+ * Isochronous packet descriptor. */
+struct libusb_iso_packet_descriptor {
+	/** Length of data to request in this packet */
+	unsigned int length;
+
+	/** Amount of data that was actually transferred */
+	unsigned int actual_length;
+
+	/** Status code for this packet */
+	enum libusb_transfer_status status;
+};
+
+struct libusb_transfer;
+
+/** \ingroup asyncio
+ * Asynchronous transfer callback function type. When submitting asynchronous
+ * transfers, you pass a pointer to a callback function of this type via the
+ * \ref libusb_transfer::callback "callback" member of the libusb_transfer
+ * structure. libusb will call this function later, when the transfer has
+ * completed or failed. See \ref asyncio for more information.
+ * \param transfer The libusb_transfer struct the callback function is being
+ * notified about.
+ */
+typedef void (LIBUSB_CALL *libusb_transfer_cb_fn)(struct libusb_transfer *transfer);
+
+/** \ingroup asyncio
+ * The generic USB transfer structure. The user populates this structure and
+ * then submits it in order to request a transfer. After the transfer has
+ * completed, the library populates the transfer with the results and passes
+ * it back to the user.
+ */
+struct libusb_transfer {
+	/** Handle of the device that this transfer will be submitted to */
+	libusb_device_handle *dev_handle;
+
+	/** A bitwise OR combination of \ref libusb_transfer_flags. */
+	uint8_t flags;
+
+	/** Address of the endpoint where this transfer will be sent. */
+	unsigned char endpoint;
+
+	/** Type of the endpoint from \ref libusb_transfer_type */
+	unsigned char type;
+
+	/** Timeout for this transfer in millseconds. A value of 0 indicates no
+	 * timeout. */
+	unsigned int timeout;
+
+	/** The status of the transfer. Read-only, and only for use within
+	 * transfer callback function.
+	 *
+	 * If this is an isochronous transfer, this field may read COMPLETED even
+	 * if there were errors in the frames. Use the
+	 * \ref libusb_iso_packet_descriptor::status "status" field in each packet
+	 * to determine if errors occurred. */
+	enum libusb_transfer_status status;
+
+	/** Length of the data buffer */
+	int length;
+
+	/** Actual length of data that was transferred. Read-only, and only for
+	 * use within transfer callback function. Not valid for isochronous
+	 * endpoint transfers. */
+	int actual_length;
+
+	/** Callback function. This will be invoked when the transfer completes,
+	 * fails, or is cancelled. */
+	libusb_transfer_cb_fn callback;
+
+	/** User context data to pass to the callback function. */
+	void *user_data;
+
+	/** Data buffer */
+	unsigned char *buffer;
+
+	/** Number of isochronous packets. Only used for I/O with isochronous
+	 * endpoints. */
+	int num_iso_packets;
+
+	/** Isochronous packet descriptors, for isochronous transfers only. */
+	struct libusb_iso_packet_descriptor iso_packet_desc
+#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)
+	[] /* valid C99 code */
+#else
+	[0] /* non-standard, but usually working code */
+#endif
+	;
+};
+
+int LIBUSB_CALL libusb_init(libusb_context **ctx);
+void LIBUSB_CALL libusb_exit(libusb_context *ctx);
+void LIBUSB_CALL libusb_set_debug(libusb_context *ctx, int level);
+const char * LIBUSB_CALL libusb_strerror(enum libusb_error errcode);
+
+ssize_t LIBUSB_CALL libusb_get_device_list(libusb_context *ctx,
+	libusb_device ***list);
+void LIBUSB_CALL libusb_free_device_list(libusb_device **list,
+	int unref_devices);
+libusb_device * LIBUSB_CALL libusb_ref_device(libusb_device *dev);
+void LIBUSB_CALL libusb_unref_device(libusb_device *dev);
+
+int LIBUSB_CALL libusb_get_configuration(libusb_device_handle *dev,
+	int *config);
+int LIBUSB_CALL libusb_get_device_descriptor(libusb_device *dev,
+	struct libusb_device_descriptor *desc);
+int LIBUSB_CALL libusb_get_active_config_descriptor(libusb_device *dev,
+	struct libusb_config_descriptor **config);
+int LIBUSB_CALL libusb_get_config_descriptor(libusb_device *dev,
+	uint8_t config_index, struct libusb_config_descriptor **config);
+int LIBUSB_CALL libusb_get_config_descriptor_by_value(libusb_device *dev,
+	uint8_t bConfigurationValue, struct libusb_config_descriptor **config);
+void LIBUSB_CALL libusb_free_config_descriptor(
+	struct libusb_config_descriptor *config);
+uint8_t LIBUSB_CALL libusb_get_bus_number(libusb_device *dev);
+uint8_t LIBUSB_CALL libusb_get_device_address(libusb_device *dev);
+int LIBUSB_CALL libusb_get_max_packet_size(libusb_device *dev,
+	unsigned char endpoint);
+int LIBUSB_CALL libusb_get_max_iso_packet_size(libusb_device *dev,
+	unsigned char endpoint);
+
+int LIBUSB_CALL libusb_open(libusb_device *dev, libusb_device_handle **handle);
+void LIBUSB_CALL libusb_close(libusb_device_handle *dev_handle);
+libusb_device * LIBUSB_CALL libusb_get_device(libusb_device_handle *dev_handle);
+
+int LIBUSB_CALL libusb_set_configuration(libusb_device_handle *dev,
+	int configuration);
+int LIBUSB_CALL libusb_claim_interface(libusb_device_handle *dev,
+	int interface_number);
+int LIBUSB_CALL libusb_release_interface(libusb_device_handle *dev,
+	int interface_number);
+
+libusb_device_handle * LIBUSB_CALL libusb_open_device_with_vid_pid(
+	libusb_context *ctx, uint16_t vendor_id, uint16_t product_id);
+
+int LIBUSB_CALL libusb_set_interface_alt_setting(libusb_device_handle *dev,
+	int interface_number, int alternate_setting);
+int LIBUSB_CALL libusb_clear_halt(libusb_device_handle *dev,
+	unsigned char endpoint);
+int LIBUSB_CALL libusb_reset_device(libusb_device_handle *dev);
+
+int LIBUSB_CALL libusb_kernel_driver_active(libusb_device_handle *dev,
+	int interface_number);
+int LIBUSB_CALL libusb_detach_kernel_driver(libusb_device_handle *dev,
+	int interface_number);
+int LIBUSB_CALL libusb_attach_kernel_driver(libusb_device_handle *dev,
+	int interface_number);
+
+/* async I/O */
+
+/** \ingroup asyncio
+ * Get the data section of a control transfer. This convenience function is here
+ * to remind you that the data does not start until 8 bytes into the actual
+ * buffer, as the setup packet comes first.
+ *
+ * Calling this function only makes sense from a transfer callback function,
+ * or situations where you have already allocated a suitably sized buffer at
+ * transfer->buffer.
+ *
+ * \param transfer a transfer
+ * \returns pointer to the first byte of the data section
+ */
+static inline unsigned char *libusb_control_transfer_get_data(
+	struct libusb_transfer *transfer)
+{
+	return transfer->buffer + LIBUSB_CONTROL_SETUP_SIZE;
+}
+
+/** \ingroup asyncio
+ * Get the control setup packet of a control transfer. This convenience
+ * function is here to remind you that the control setup occupies the first
+ * 8 bytes of the transfer data buffer.
+ *
+ * Calling this function only makes sense from a transfer callback function,
+ * or situations where you have already allocated a suitably sized buffer at
+ * transfer->buffer.
+ *
+ * \param transfer a transfer
+ * \returns a casted pointer to the start of the transfer data buffer
+ */
+static inline struct libusb_control_setup *libusb_control_transfer_get_setup(
+	struct libusb_transfer *transfer)
+{
+	return (struct libusb_control_setup *) transfer->buffer;
+}
+
+/** \ingroup asyncio
+ * Helper function to populate the setup packet (first 8 bytes of the data
+ * buffer) for a control transfer. The wIndex, wValue and wLength values should
+ * be given in host-endian byte order.
+ *
+ * \param buffer buffer to output the setup packet into
+ * \param bmRequestType see the
+ * \ref libusb_control_setup::bmRequestType "bmRequestType" field of
+ * \ref libusb_control_setup
+ * \param bRequest see the
+ * \ref libusb_control_setup::bRequest "bRequest" field of
+ * \ref libusb_control_setup
+ * \param wValue see the
+ * \ref libusb_control_setup::wValue "wValue" field of
+ * \ref libusb_control_setup
+ * \param wIndex see the
+ * \ref libusb_control_setup::wIndex "wIndex" field of
+ * \ref libusb_control_setup
+ * \param wLength see the
+ * \ref libusb_control_setup::wLength "wLength" field of
+ * \ref libusb_control_setup
+ */
+static inline void libusb_fill_control_setup(unsigned char *buffer,
+	uint8_t bmRequestType, uint8_t bRequest, uint16_t wValue, uint16_t wIndex,
+	uint16_t wLength)
+{
+	struct libusb_control_setup *setup = (struct libusb_control_setup *) buffer;
+	setup->bmRequestType = bmRequestType;
+	setup->bRequest = bRequest;
+	setup->wValue = libusb_cpu_to_le16(wValue);
+	setup->wIndex = libusb_cpu_to_le16(wIndex);
+	setup->wLength = libusb_cpu_to_le16(wLength);
+}
+
+struct libusb_transfer * LIBUSB_CALL libusb_alloc_transfer(int iso_packets);
+int LIBUSB_CALL libusb_submit_transfer(struct libusb_transfer *transfer);
+int LIBUSB_CALL libusb_cancel_transfer(struct libusb_transfer *transfer);
+void LIBUSB_CALL libusb_free_transfer(struct libusb_transfer *transfer);
+
+/** \ingroup asyncio
+ * Helper function to populate the required \ref libusb_transfer fields
+ * for a control transfer.
+ *
+ * If you pass a transfer buffer to this function, the first 8 bytes will
+ * be interpreted as a control setup packet, and the wLength field will be
+ * used to automatically populate the \ref libusb_transfer::length "length"
+ * field of the transfer. Therefore the recommended approach is:
+ * -# Allocate a suitably sized data buffer (including space for control setup)
+ * -# Call libusb_fill_control_setup()
+ * -# If this is a host-to-device transfer with a data stage, put the data
+ *    in place after the setup packet
+ * -# Call this function
+ * -# Call libusb_submit_transfer()
+ *
+ * It is also legal to pass a NULL buffer to this function, in which case this
+ * function will not attempt to populate the length field. Remember that you
+ * must then populate the buffer and length fields later.
+ *
+ * \param transfer the transfer to populate
+ * \param dev_handle handle of the device that will handle the transfer
+ * \param buffer data buffer. If provided, this function will interpret the
+ * first 8 bytes as a setup packet and infer the transfer length from that.
+ * \param callback callback function to be invoked on transfer completion
+ * \param user_data user data to pass to callback function
+ * \param timeout timeout for the transfer in milliseconds
+ */
+static inline void libusb_fill_control_transfer(
+	struct libusb_transfer *transfer, libusb_device_handle *dev_handle,
+	unsigned char *buffer, libusb_transfer_cb_fn callback, void *user_data,
+	unsigned int timeout)
+{
+	struct libusb_control_setup *setup = (struct libusb_control_setup *) buffer;
+	transfer->dev_handle = dev_handle;
+	transfer->endpoint = 0;
+	transfer->type = LIBUSB_TRANSFER_TYPE_CONTROL;
+	transfer->timeout = timeout;
+	transfer->buffer = buffer;
+	if (setup)
+		transfer->length = LIBUSB_CONTROL_SETUP_SIZE
+			+ libusb_le16_to_cpu(setup->wLength);
+	transfer->user_data = user_data;
+	transfer->callback = callback;
+}
+
+/** \ingroup asyncio
+ * Helper function to populate the required \ref libusb_transfer fields
+ * for a bulk transfer.
+ *
+ * \param transfer the transfer to populate
+ * \param dev_handle handle of the device that will handle the transfer
+ * \param endpoint address of the endpoint where this transfer will be sent
+ * \param buffer data buffer
+ * \param length length of data buffer
+ * \param callback callback function to be invoked on transfer completion
+ * \param user_data user data to pass to callback function
+ * \param timeout timeout for the transfer in milliseconds
+ */
+static inline void libusb_fill_bulk_transfer(struct libusb_transfer *transfer,
+	libusb_device_handle *dev_handle, unsigned char endpoint,
+	unsigned char *buffer, int length, libusb_transfer_cb_fn callback,
+	void *user_data, unsigned int timeout)
+{
+	transfer->dev_handle = dev_handle;
+	transfer->endpoint = endpoint;
+	transfer->type = LIBUSB_TRANSFER_TYPE_BULK;
+	transfer->timeout = timeout;
+	transfer->buffer = buffer;
+	transfer->length = length;
+	transfer->user_data = user_data;
+	transfer->callback = callback;
+}
+
+/** \ingroup asyncio
+ * Helper function to populate the required \ref libusb_transfer fields
+ * for an interrupt transfer.
+ *
+ * \param transfer the transfer to populate
+ * \param dev_handle handle of the device that will handle the transfer
+ * \param endpoint address of the endpoint where this transfer will be sent
+ * \param buffer data buffer
+ * \param length length of data buffer
+ * \param callback callback function to be invoked on transfer completion
+ * \param user_data user data to pass to callback function
+ * \param timeout timeout for the transfer in milliseconds
+ */
+static inline void libusb_fill_interrupt_transfer(
+	struct libusb_transfer *transfer, libusb_device_handle *dev_handle,
+	unsigned char endpoint, unsigned char *buffer, int length,
+	libusb_transfer_cb_fn callback, void *user_data, unsigned int timeout)
+{
+	transfer->dev_handle = dev_handle;
+	transfer->endpoint = endpoint;
+	transfer->type = LIBUSB_TRANSFER_TYPE_INTERRUPT;
+	transfer->timeout = timeout;
+	transfer->buffer = buffer;
+	transfer->length = length;
+	transfer->user_data = user_data;
+	transfer->callback = callback;
+}
+
+/** \ingroup asyncio
+ * Helper function to populate the required \ref libusb_transfer fields
+ * for an isochronous transfer.
+ *
+ * \param transfer the transfer to populate
+ * \param dev_handle handle of the device that will handle the transfer
+ * \param endpoint address of the endpoint where this transfer will be sent
+ * \param buffer data buffer
+ * \param length length of data buffer
+ * \param num_iso_packets the number of isochronous packets
+ * \param callback callback function to be invoked on transfer completion
+ * \param user_data user data to pass to callback function
+ * \param timeout timeout for the transfer in milliseconds
+ */
+static inline void libusb_fill_iso_transfer(struct libusb_transfer *transfer,
+	libusb_device_handle *dev_handle, unsigned char endpoint,
+	unsigned char *buffer, int length, int num_iso_packets,
+	libusb_transfer_cb_fn callback, void *user_data, unsigned int timeout)
+{
+	transfer->dev_handle = dev_handle;
+	transfer->endpoint = endpoint;
+	transfer->type = LIBUSB_TRANSFER_TYPE_ISOCHRONOUS;
+	transfer->timeout = timeout;
+	transfer->buffer = buffer;
+	transfer->length = length;
+	transfer->num_iso_packets = num_iso_packets;
+	transfer->user_data = user_data;
+	transfer->callback = callback;
+}
+
+/** \ingroup asyncio
+ * Convenience function to set the length of all packets in an isochronous
+ * transfer, based on the num_iso_packets field in the transfer structure.
+ *
+ * \param transfer a transfer
+ * \param length the length to set in each isochronous packet descriptor
+ * \see libusb_get_max_packet_size()
+ */
+static inline void libusb_set_iso_packet_lengths(
+	struct libusb_transfer *transfer, unsigned int length)
+{
+	int i;
+	for (i = 0; i < transfer->num_iso_packets; i++)
+		transfer->iso_packet_desc[i].length = length;
+}
+
+/** \ingroup asyncio
+ * Convenience function to locate the position of an isochronous packet
+ * within the buffer of an isochronous transfer.
+ *
+ * This is a thorough function which loops through all preceding packets,
+ * accumulating their lengths to find the position of the specified packet.
+ * Typically you will assign equal lengths to each packet in the transfer,
+ * and hence the above method is sub-optimal. You may wish to use
+ * libusb_get_iso_packet_buffer_simple() instead.
+ *
+ * \param transfer a transfer
+ * \param packet the packet to return the address of
+ * \returns the base address of the packet buffer inside the transfer buffer,
+ * or NULL if the packet does not exist.
+ * \see libusb_get_iso_packet_buffer_simple()
+ */
+static inline unsigned char *libusb_get_iso_packet_buffer(
+	struct libusb_transfer *transfer, unsigned int packet)
+{
+	int i;
+	size_t offset = 0;
+	int _packet;
+
+	/* oops..slight bug in the API. packet is an unsigned int, but we use
+	 * signed integers almost everywhere else. range-check and convert to
+	 * signed to avoid compiler warnings. FIXME for libusb-2. */
+	if (packet > INT_MAX)
+		return NULL;
+	_packet = packet;
+
+	if (_packet >= transfer->num_iso_packets)
+		return NULL;
+
+	for (i = 0; i < _packet; i++)
+		offset += transfer->iso_packet_desc[i].length;
+
+	return transfer->buffer + offset;
+}
+
+/** \ingroup asyncio
+ * Convenience function to locate the position of an isochronous packet
+ * within the buffer of an isochronous transfer, for transfers where each
+ * packet is of identical size.
+ *
+ * This function relies on the assumption that every packet within the transfer
+ * is of identical size to the first packet. Calculating the location of
+ * the packet buffer is then just a simple calculation:
+ * <tt>buffer + (packet_size * packet)</tt>
+ *
+ * Do not use this function on transfers other than those that have identical
+ * packet lengths for each packet.
+ *
+ * \param transfer a transfer
+ * \param packet the packet to return the address of
+ * \returns the base address of the packet buffer inside the transfer buffer,
+ * or NULL if the packet does not exist.
+ * \see libusb_get_iso_packet_buffer()
+ */
+static inline unsigned char *libusb_get_iso_packet_buffer_simple(
+	struct libusb_transfer *transfer, unsigned int packet)
+{
+	int _packet;
+
+	/* oops..slight bug in the API. packet is an unsigned int, but we use
+	 * signed integers almost everywhere else. range-check and convert to
+	 * signed to avoid compiler warnings. FIXME for libusb-2. */
+	if (packet > INT_MAX)
+		return NULL;
+	_packet = packet;
+
+	if (_packet >= transfer->num_iso_packets)
+		return NULL;
+
+	return transfer->buffer + (transfer->iso_packet_desc[0].length * _packet);
+}
+
+/* sync I/O */
+
+int LIBUSB_CALL libusb_control_transfer(libusb_device_handle *dev_handle,
+	uint8_t request_type, uint8_t bRequest, uint16_t wValue, uint16_t wIndex,
+	unsigned char *data, uint16_t wLength, unsigned int timeout);
+
+int LIBUSB_CALL libusb_bulk_transfer(libusb_device_handle *dev_handle,
+	unsigned char endpoint, unsigned char *data, int length,
+	int *actual_length, unsigned int timeout);
+
+int LIBUSB_CALL libusb_interrupt_transfer(libusb_device_handle *dev_handle,
+	unsigned char endpoint, unsigned char *data, int length,
+	int *actual_length, unsigned int timeout);
+
+/** \ingroup desc
+ * Retrieve a descriptor from the default control pipe.
+ * This is a convenience function which formulates the appropriate control
+ * message to retrieve the descriptor.
+ *
+ * \param dev a device handle
+ * \param desc_type the descriptor type, see \ref libusb_descriptor_type
+ * \param desc_index the index of the descriptor to retrieve
+ * \param data output buffer for descriptor
+ * \param length size of data buffer
+ * \returns number of bytes returned in data, or LIBUSB_ERROR code on failure
+ */
+static inline int libusb_get_descriptor(libusb_device_handle *dev,
+	uint8_t desc_type, uint8_t desc_index, unsigned char *data, int length)
+{
+	return libusb_control_transfer(dev, LIBUSB_ENDPOINT_IN,
+		LIBUSB_REQUEST_GET_DESCRIPTOR, (desc_type << 8) | desc_index, 0, data,
+		(uint16_t) length, 1000);
+}
+
+/** \ingroup desc
+ * Retrieve a descriptor from a device.
+ * This is a convenience function which formulates the appropriate control
+ * message to retrieve the descriptor. The string returned is Unicode, as
+ * detailed in the USB specifications.
+ *
+ * \param dev a device handle
+ * \param desc_index the index of the descriptor to retrieve
+ * \param langid the language ID for the string descriptor
+ * \param data output buffer for descriptor
+ * \param length size of data buffer
+ * \returns number of bytes returned in data, or LIBUSB_ERROR code on failure
+ * \see libusb_get_string_descriptor_ascii()
+ */
+static inline int libusb_get_string_descriptor(libusb_device_handle *dev,
+	uint8_t desc_index, uint16_t langid, unsigned char *data, int length)
+{
+	return libusb_control_transfer(dev, LIBUSB_ENDPOINT_IN,
+		LIBUSB_REQUEST_GET_DESCRIPTOR, (LIBUSB_DT_STRING << 8) | desc_index,
+		langid, data, (uint16_t) length, 1000);
+}
+
+int LIBUSB_CALL libusb_get_string_descriptor_ascii(libusb_device_handle *dev,
+	uint8_t desc_index, unsigned char *data, int length);
+
+/* polling and timeouts */
+
+int LIBUSB_CALL libusb_try_lock_events(libusb_context *ctx);
+void LIBUSB_CALL libusb_lock_events(libusb_context *ctx);
+void LIBUSB_CALL libusb_unlock_events(libusb_context *ctx);
+int LIBUSB_CALL libusb_event_handling_ok(libusb_context *ctx);
+int LIBUSB_CALL libusb_event_handler_active(libusb_context *ctx);
+void LIBUSB_CALL libusb_lock_event_waiters(libusb_context *ctx);
+void LIBUSB_CALL libusb_unlock_event_waiters(libusb_context *ctx);
+int LIBUSB_CALL libusb_wait_for_event(libusb_context *ctx, struct timeval *tv);
+
+int LIBUSB_CALL libusb_handle_events_timeout(libusb_context *ctx,
+	struct timeval *tv);
+int LIBUSB_CALL libusb_handle_events(libusb_context *ctx);
+int LIBUSB_CALL libusb_handle_events_locked(libusb_context *ctx,
+	struct timeval *tv);
+int LIBUSB_CALL libusb_pollfds_handle_timeouts(libusb_context *ctx);
+int LIBUSB_CALL libusb_get_next_timeout(libusb_context *ctx,
+	struct timeval *tv);
+
+/** \ingroup poll
+ * File descriptor for polling
+ */
+struct libusb_pollfd {
+	/** Numeric file descriptor */
+	int fd;
+
+	/** Event flags to poll for from <poll.h>. POLLIN indicates that you
+	 * should monitor this file descriptor for becoming ready to read from,
+	 * and POLLOUT indicates that you should monitor this file descriptor for
+	 * nonblocking write readiness. */
+	short events;
+};
+
+/** \ingroup poll
+ * Callback function, invoked when a new file descriptor should be added
+ * to the set of file descriptors monitored for events.
+ * \param fd the new file descriptor
+ * \param events events to monitor for, see \ref libusb_pollfd for a
+ * description
+ * \param user_data User data pointer specified in
+ * libusb_set_pollfd_notifiers() call
+ * \see libusb_set_pollfd_notifiers()
+ */
+typedef void (LIBUSB_CALL *libusb_pollfd_added_cb)(int fd, short events,
+	void *user_data);
+
+/** \ingroup poll
+ * Callback function, invoked when a file descriptor should be removed from
+ * the set of file descriptors being monitored for events. After returning
+ * from this callback, do not use that file descriptor again.
+ * \param fd the file descriptor to stop monitoring
+ * \param user_data User data pointer specified in
+ * libusb_set_pollfd_notifiers() call
+ * \see libusb_set_pollfd_notifiers()
+ */
+typedef void (LIBUSB_CALL *libusb_pollfd_removed_cb)(int fd, void *user_data);
+
+const struct libusb_pollfd ** LIBUSB_CALL libusb_get_pollfds(
+	libusb_context *ctx);
+void LIBUSB_CALL libusb_set_pollfd_notifiers(libusb_context *ctx,
+	libusb_pollfd_added_cb added_cb, libusb_pollfd_removed_cb removed_cb,
+	void *user_data);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/include/libusb-1.0/libusbi.h b/include/libusb-1.0/libusbi.h
new file mode 100644
index 0000000..9b2fa70
--- /dev/null
+++ b/include/libusb-1.0/libusbi.h
@@ -0,0 +1,872 @@
+/*
+ * Internal header for libusb
+ * Copyright (C) 2007-2009 Daniel Drake <dsd@gentoo.org>
+ * Copyright (c) 2001 Johannes Erdfelt <johannes@erdfelt.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef __LIBUSBI_H__
+#define __LIBUSBI_H__
+
+#include <config.h>
+
+#include <stddef.h>
+#include <stdint.h>
+#include <time.h>
+
+#include <libusb.h>
+
+/* Inside the libusb code, mark all public functions as follows:
+ *   return_type API_EXPORTED function_name(params) { ... }
+ * But if the function returns a pointer, mark it as follows:
+ *   DEFAULT_VISIBILITY return_type * LIBUSB_CALL function_name(params) { ... }
+ * In the libusb public header, mark all declarations as:
+ *   return_type LIBUSB_CALL function_name(params);
+ */
+#define API_EXPORTED LIBUSB_CALL DEFAULT_VISIBILITY
+
+#define DEVICE_DESC_LENGTH		18
+
+#define USB_MAXENDPOINTS	32
+#define USB_MAXINTERFACES	32
+#define USB_MAXCONFIG		8
+
+struct list_head {
+	struct list_head *prev, *next;
+};
+
+/* Get an entry from the list
+ * 	ptr - the address of this list_head element in "type"
+ * 	type - the data type that contains "member"
+ * 	member - the list_head element in "type"
+ */
+#define list_entry(ptr, type, member) \
+	((type *)((uintptr_t)(ptr) - (uintptr_t)(&((type *)0L)->member)))
+
+/* Get each entry from a list
+ *	pos - A structure pointer has a "member" element
+ *	head - list head
+ *	member - the list_head element in "pos"
+ *	type - the type of the first parameter
+ */
+#define list_for_each_entry(pos, head, member, type)			\
+	for (pos = list_entry((head)->next, type, member);			\
+		 &pos->member != (head);								\
+		 pos = list_entry(pos->member.next, type, member))
+
+#define list_for_each_entry_safe(pos, n, head, member, type)	\
+	for (pos = list_entry((head)->next, type, member),			\
+		 n = list_entry(pos->member.next, type, member);		\
+		 &pos->member != (head);								\
+		 pos = n, n = list_entry(n->member.next, type, member))
+
+#define list_empty(entry) ((entry)->next == (entry))
+
+static inline void list_init(struct list_head *entry)
+{
+	entry->prev = entry->next = entry;
+}
+
+static inline void list_add(struct list_head *entry, struct list_head *head)
+{
+	entry->next = head->next;
+	entry->prev = head;
+
+	head->next->prev = entry;
+	head->next = entry;
+}
+
+static inline void list_add_tail(struct list_head *entry,
+	struct list_head *head)
+{
+	entry->next = head;
+	entry->prev = head->prev;
+
+	head->prev->next = entry;
+	head->prev = entry;
+}
+
+static inline void list_del(struct list_head *entry)
+{
+	entry->next->prev = entry->prev;
+	entry->prev->next = entry->next;
+}
+
+#define container_of(ptr, type, member) ({                      \
+        const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
+        (type *)( (char *)__mptr - offsetof(type,member) );})
+
+#define MIN(a, b)	((a) < (b) ? (a) : (b))
+#define MAX(a, b)	((a) > (b) ? (a) : (b))
+
+#define TIMESPEC_IS_SET(ts) ((ts)->tv_sec != 0 || (ts)->tv_nsec != 0)
+
+enum usbi_log_level {
+	LOG_LEVEL_DEBUG,
+	LOG_LEVEL_INFO,
+	LOG_LEVEL_WARNING,
+	LOG_LEVEL_ERROR,
+};
+
+void usbi_log(struct libusb_context *ctx, enum usbi_log_level level,
+	const char *function, const char *format, ...);
+
+#if !defined(_MSC_VER) || _MSC_VER > 1200
+
+#ifdef ENABLE_LOGGING
+#define _usbi_log(ctx, level, ...) usbi_log(ctx, level, __FUNCTION__, __VA_ARGS__)
+#else
+#define _usbi_log(ctx, level, ...)
+#endif
+
+#ifdef ENABLE_DEBUG_LOGGING
+#define usbi_dbg(...) _usbi_log(NULL, LOG_LEVEL_DEBUG, __VA_ARGS__)
+#else
+#define usbi_dbg(...)
+#endif
+
+#define usbi_info(ctx, ...) _usbi_log(ctx, LOG_LEVEL_INFO, __VA_ARGS__)
+#define usbi_warn(ctx, ...) _usbi_log(ctx, LOG_LEVEL_WARNING, __VA_ARGS__)
+#define usbi_err(ctx, ...) _usbi_log(ctx, LOG_LEVEL_ERROR, __VA_ARGS__)
+
+#else /* !defined(_MSC_VER) || _MSC_VER > 1200 */
+
+void usbi_log_v(struct libusb_context *ctx, enum usbi_log_level level,
+	const char *function, const char *format, va_list args);
+
+#ifdef ENABLE_LOGGING
+#define LOG_BODY(ctxt, level) \
+{                             \
+	va_list args;             \
+	va_start (args, format);  \
+	usbi_log_v(ctxt, level, "", format, args); \
+	va_end(args);             \
+}
+#else
+#define LOG_BODY(ctxt, level) { }
+#endif
+
+static inline void usbi_info(struct libusb_context *ctx, const char *format,
+	...)
+	LOG_BODY(ctx,LOG_LEVEL_INFO)
+static inline void usbi_warn(struct libusb_context *ctx, const char *format,
+	...)
+	LOG_BODY(ctx,LOG_LEVEL_WARNING)
+static inline void usbi_err( struct libusb_context *ctx, const char *format,
+	...)
+	LOG_BODY(ctx,LOG_LEVEL_ERROR)
+
+static inline void usbi_dbg(const char *format, ...)
+#ifdef ENABLE_DEBUG_LOGGING
+	LOG_BODY(NULL,LOG_LEVEL_DEBUG)
+#else
+{ }
+#endif
+
+#endif /* !defined(_MSC_VER) || _MSC_VER > 1200 */
+
+#define USBI_GET_CONTEXT(ctx) if (!(ctx)) (ctx) = usbi_default_context
+#define DEVICE_CTX(dev) ((dev)->ctx)
+#define HANDLE_CTX(handle) (DEVICE_CTX((handle)->dev))
+#define TRANSFER_CTX(transfer) (HANDLE_CTX((transfer)->dev_handle))
+#define ITRANSFER_CTX(transfer) \
+	(TRANSFER_CTX(__USBI_TRANSFER_TO_LIBUSB_TRANSFER(transfer)))
+
+/* Internal abstractions for thread synchronization and poll */
+#if defined(THREADS_POSIX)
+#include <os/threads_posix.h>
+#elif defined(OS_WINDOWS)
+#include <os/threads_windows.h>
+#endif
+
+#if defined(OS_LINUX) || defined(OS_DARWIN)
+#include <os/poll_posix.h>
+#elif defined(OS_WINDOWS)
+#include <os/poll_windows.h>
+#endif
+
+extern struct libusb_context *usbi_default_context;
+
+struct libusb_context {
+	int debug;
+	int debug_fixed;
+
+	/* internal control pipe, used for interrupting event handling when
+	 * something needs to modify poll fds. */
+	int ctrl_pipe[2];
+
+	struct list_head usb_devs;
+	usbi_mutex_t usb_devs_lock;
+
+	/* A list of open handles. Backends are free to traverse this if required.
+	 */
+	struct list_head open_devs;
+	usbi_mutex_t open_devs_lock;
+
+	/* this is a list of in-flight transfer handles, sorted by timeout
+	 * expiration. URBs to timeout the soonest are placed at the beginning of
+	 * the list, URBs that will time out later are placed after, and urbs with
+	 * infinite timeout are always placed at the very end. */
+	struct list_head flying_transfers;
+	usbi_mutex_t flying_transfers_lock;
+
+	/* list of poll fds */
+	struct list_head pollfds;
+	usbi_mutex_t pollfds_lock;
+
+	/* a counter that is set when we want to interrupt event handling, in order
+	 * to modify the poll fd set. and a lock to protect it. */
+	unsigned int pollfd_modify;
+	usbi_mutex_t pollfd_modify_lock;
+
+	/* user callbacks for pollfd changes */
+	libusb_pollfd_added_cb fd_added_cb;
+	libusb_pollfd_removed_cb fd_removed_cb;
+	void *fd_cb_user_data;
+
+	/* ensures that only one thread is handling events at any one time */
+	usbi_mutex_t events_lock;
+
+	/* used to see if there is an active thread doing event handling */
+	int event_handler_active;
+
+	/* used to wait for event completion in threads other than the one that is
+	 * event handling */
+	usbi_mutex_t event_waiters_lock;
+	usbi_cond_t event_waiters_cond;
+
+#ifdef USBI_TIMERFD_AVAILABLE
+	/* used for timeout handling, if supported by OS.
+	 * this timerfd is maintained to trigger on the next pending timeout */
+	int timerfd;
+#endif
+};
+
+#ifdef USBI_TIMERFD_AVAILABLE
+#define usbi_using_timerfd(ctx) ((ctx)->timerfd >= 0)
+#else
+#define usbi_using_timerfd(ctx) (0)
+#endif
+
+struct libusb_device {
+	/* lock protects refcnt, everything else is finalized at initialization
+	 * time */
+	usbi_mutex_t lock;
+	int refcnt;
+
+	struct libusb_context *ctx;
+
+	uint8_t bus_number;
+	uint8_t device_address;
+	uint8_t num_configurations;
+
+	struct list_head list;
+	unsigned long session_data;
+	unsigned char os_priv[0];
+};
+
+struct libusb_device_handle {
+	/* lock protects claimed_interfaces */
+	usbi_mutex_t lock;
+	unsigned long claimed_interfaces;
+
+	struct list_head list;
+	struct libusb_device *dev;
+	unsigned char os_priv[0];
+};
+
+#define USBI_TRANSFER_TIMED_OUT	 			(1<<0)
+
+enum {
+  USBI_CLOCK_MONOTONIC,
+  USBI_CLOCK_REALTIME
+};
+
+/* in-memory transfer layout:
+ *
+ * 1. struct usbi_transfer
+ * 2. struct libusb_transfer (which includes iso packets) [variable size]
+ * 3. os private data [variable size]
+ *
+ * from a libusb_transfer, you can get the usbi_transfer by rewinding the
+ * appropriate number of bytes.
+ * the usbi_transfer includes the number of allocated packets, so you can
+ * determine the size of the transfer and hence the start and length of the
+ * OS-private data.
+ */
+
+struct usbi_transfer {
+	int num_iso_packets;
+	struct list_head list;
+	struct timeval timeout;
+	int transferred;
+	uint8_t flags;
+
+	/* this lock is held during libusb_submit_transfer() and
+	 * libusb_cancel_transfer() (allowing the OS backend to prevent duplicate
+	 * cancellation, submission-during-cancellation, etc). the OS backend
+	 * should also take this lock in the handle_events path, to prevent the user
+	 * cancelling the transfer from another thread while you are processing
+	 * its completion (presumably there would be races within your OS backend
+	 * if this were possible). */
+	usbi_mutex_t lock;
+};
+
+#define __USBI_TRANSFER_TO_LIBUSB_TRANSFER(transfer) \
+	((struct libusb_transfer *)(((unsigned char *)(transfer)) \
+		+ sizeof(struct usbi_transfer)))
+#define __LIBUSB_TRANSFER_TO_USBI_TRANSFER(transfer) \
+	((struct usbi_transfer *)(((unsigned char *)(transfer)) \
+		- sizeof(struct usbi_transfer)))
+
+static inline void *usbi_transfer_get_os_priv(struct usbi_transfer *transfer)
+{
+	return ((unsigned char *)transfer) + sizeof(struct usbi_transfer)
+		+ sizeof(struct libusb_transfer)
+		+ (transfer->num_iso_packets
+			* sizeof(struct libusb_iso_packet_descriptor));
+}
+
+/* bus structures */
+
+/* All standard descriptors have these 2 fields in common */
+struct usb_descriptor_header {
+	uint8_t  bLength;
+	uint8_t  bDescriptorType;
+};
+
+/* shared data and functions */
+
+int usbi_io_init(struct libusb_context *ctx);
+void usbi_io_exit(struct libusb_context *ctx);
+
+struct libusb_device *usbi_alloc_device(struct libusb_context *ctx,
+	unsigned long session_id);
+struct libusb_device *usbi_get_device_by_session_id(struct libusb_context *ctx,
+	unsigned long session_id);
+int usbi_sanitize_device(struct libusb_device *dev);
+void usbi_handle_disconnect(struct libusb_device_handle *handle);
+
+int usbi_handle_transfer_completion(struct usbi_transfer *itransfer,
+	enum libusb_transfer_status status);
+int usbi_handle_transfer_cancellation(struct usbi_transfer *transfer);
+
+int usbi_parse_descriptor(unsigned char *source, char *descriptor, void *dest,
+	int host_endian);
+int usbi_get_config_index_by_value(struct libusb_device *dev,
+	uint8_t bConfigurationValue, int *idx);
+
+/* polling */
+
+struct usbi_pollfd {
+	/* must come first */
+	struct libusb_pollfd pollfd;
+
+	struct list_head list;
+};
+
+int usbi_add_pollfd(struct libusb_context *ctx, int fd, short events);
+void usbi_remove_pollfd(struct libusb_context *ctx, int fd);
+void usbi_fd_notification(struct libusb_context *ctx);
+
+/* device discovery */
+
+/* we traverse usbfs without knowing how many devices we are going to find.
+ * so we create this discovered_devs model which is similar to a linked-list
+ * which grows when required. it can be freed once discovery has completed,
+ * eliminating the need for a list node in the libusb_device structure
+ * itself. */
+struct discovered_devs {
+	size_t len;
+	size_t capacity;
+	struct libusb_device *devices[0];
+};
+
+struct discovered_devs *discovered_devs_append(
+	struct discovered_devs *discdevs, struct libusb_device *dev);
+
+/* OS abstraction */
+
+/* This is the interface that OS backends need to implement.
+ * All fields are mandatory, except ones explicitly noted as optional. */
+struct usbi_os_backend {
+	/* A human-readable name for your backend, e.g. "Linux usbfs" */
+	const char *name;
+
+	/* Perform initialization of your backend. You might use this function
+	 * to determine specific capabilities of the system, allocate required
+	 * data structures for later, etc.
+	 *
+	 * This function is called when a libusb user initializes the library
+	 * prior to use.
+	 *
+	 * Return 0 on success, or a LIBUSB_ERROR code on failure.
+	 */
+	int (*init)(struct libusb_context *ctx);
+
+	/* Deinitialization. Optional. This function should destroy anything
+	 * that was set up by init.
+	 *
+	 * This function is called when the user deinitializes the library.
+	 */
+	void (*exit)(void);
+
+	/* Enumerate all the USB devices on the system, returning them in a list
+	 * of discovered devices.
+	 *
+	 * Your implementation should enumerate all devices on the system,
+	 * regardless of whether they have been seen before or not.
+	 *
+	 * When you have found a device, compute a session ID for it. The session
+	 * ID should uniquely represent that particular device for that particular
+	 * connection session since boot (i.e. if you disconnect and reconnect a
+	 * device immediately after, it should be assigned a different session ID).
+	 * If your OS cannot provide a unique session ID as described above,
+	 * presenting a session ID of (bus_number << 8 | device_address) should
+	 * be sufficient. Bus numbers and device addresses wrap and get reused,
+	 * but that is an unlikely case.
+	 *
+	 * After computing a session ID for a device, call
+	 * usbi_get_device_by_session_id(). This function checks if libusb already
+	 * knows about the device, and if so, it provides you with a libusb_device
+	 * structure for it.
+	 *
+	 * If usbi_get_device_by_session_id() returns NULL, it is time to allocate
+	 * a new device structure for the device. Call usbi_alloc_device() to
+	 * obtain a new libusb_device structure with reference count 1. Populate
+	 * the bus_number and device_address attributes of the new device, and
+	 * perform any other internal backend initialization you need to do. At
+	 * this point, you should be ready to provide device descriptors and so
+	 * on through the get_*_descriptor functions. Finally, call
+	 * usbi_sanitize_device() to perform some final sanity checks on the
+	 * device. Assuming all of the above succeeded, we can now continue.
+	 * If any of the above failed, remember to unreference the device that
+	 * was returned by usbi_alloc_device().
+	 *
+	 * At this stage we have a populated libusb_device structure (either one
+	 * that was found earlier, or one that we have just allocated and
+	 * populated). This can now be added to the discovered devices list
+	 * using discovered_devs_append(). Note that discovered_devs_append()
+	 * may reallocate the list, returning a new location for it, and also
+	 * note that reallocation can fail. Your backend should handle these
+	 * error conditions appropriately.
+	 *
+	 * This function should not generate any bus I/O and should not block.
+	 * If I/O is required (e.g. reading the active configuration value), it is
+	 * OK to ignore these suggestions :)
+	 *
+	 * This function is executed when the user wishes to retrieve a list
+	 * of USB devices connected to the system.
+	 *
+	 * Return 0 on success, or a LIBUSB_ERROR code on failure.
+	 */
+	int (*get_device_list)(struct libusb_context *ctx,
+		struct discovered_devs **discdevs);
+
+	/* Open a device for I/O and other USB operations. The device handle
+	 * is preallocated for you, you can retrieve the device in question
+	 * through handle->dev.
+	 *
+	 * Your backend should allocate any internal resources required for I/O
+	 * and other operations so that those operations can happen (hopefully)
+	 * without hiccup. This is also a good place to inform libusb that it
+	 * should monitor certain file descriptors related to this device -
+	 * see the usbi_add_pollfd() function.
+	 *
+	 * This function should not generate any bus I/O and should not block.
+	 *
+	 * This function is called when the user attempts to obtain a device
+	 * handle for a device.
+	 *
+	 * Return:
+	 * - 0 on success
+	 * - LIBUSB_ERROR_ACCESS if the user has insufficient permissions
+	 * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since
+	 *   discovery
+	 * - another LIBUSB_ERROR code on other failure
+	 *
+	 * Do not worry about freeing the handle on failed open, the upper layers
+	 * do this for you.
+	 */
+	int (*open)(struct libusb_device_handle *handle);
+
+	/* Close a device such that the handle cannot be used again. Your backend
+	 * should destroy any resources that were allocated in the open path.
+	 * This may also be a good place to call usbi_remove_pollfd() to inform
+	 * libusb of any file descriptors associated with this device that should
+	 * no longer be monitored.
+	 *
+	 * This function is called when the user closes a device handle.
+	 */
+	void (*close)(struct libusb_device_handle *handle);
+
+	/* Retrieve the device descriptor from a device.
+	 *
+	 * The descriptor should be retrieved from memory, NOT via bus I/O to the
+	 * device. This means that you may have to cache it in a private structure
+	 * during get_device_list enumeration. Alternatively, you may be able
+	 * to retrieve it from a kernel interface (some Linux setups can do this)
+	 * still without generating bus I/O.
+	 *
+	 * This function is expected to write DEVICE_DESC_LENGTH (18) bytes into
+	 * buffer, which is guaranteed to be big enough.
+	 *
+	 * This function is called when sanity-checking a device before adding
+	 * it to the list of discovered devices, and also when the user requests
+	 * to read the device descriptor.
+	 *
+	 * This function is expected to return the descriptor in bus-endian format
+	 * (LE). If it returns the multi-byte values in host-endian format,
+	 * set the host_endian output parameter to "1".
+	 *
+	 * Return 0 on success or a LIBUSB_ERROR code on failure.
+	 */
+	int (*get_device_descriptor)(struct libusb_device *device,
+		unsigned char *buffer, int *host_endian);
+
+	/* Get the ACTIVE configuration descriptor for a device.
+	 *
+	 * The descriptor should be retrieved from memory, NOT via bus I/O to the
+	 * device. This means that you may have to cache it in a private structure
+	 * during get_device_list enumeration. You may also have to keep track
+	 * of which configuration is active when the user changes it.
+	 *
+	 * This function is expected to write len bytes of data into buffer, which
+	 * is guaranteed to be big enough. If you can only do a partial write,
+	 * return an error code.
+	 *
+	 * This function is expected to return the descriptor in bus-endian format
+	 * (LE). If it returns the multi-byte values in host-endian format,
+	 * set the host_endian output parameter to "1".
+	 *
+	 * Return:
+	 * - 0 on success
+	 * - LIBUSB_ERROR_NOT_FOUND if the device is in unconfigured state
+	 * - another LIBUSB_ERROR code on other failure
+	 */
+	int (*get_active_config_descriptor)(struct libusb_device *device,
+		unsigned char *buffer, size_t len, int *host_endian);
+
+	/* Get a specific configuration descriptor for a device.
+	 *
+	 * The descriptor should be retrieved from memory, NOT via bus I/O to the
+	 * device. This means that you may have to cache it in a private structure
+	 * during get_device_list enumeration.
+	 *
+	 * The requested descriptor is expressed as a zero-based index (i.e. 0
+	 * indicates that we are requesting the first descriptor). The index does
+	 * not (necessarily) equal the bConfigurationValue of the configuration
+	 * being requested.
+	 *
+	 * This function is expected to write len bytes of data into buffer, which
+	 * is guaranteed to be big enough. If you can only do a partial write,
+	 * return an error code.
+	 *
+	 * This function is expected to return the descriptor in bus-endian format
+	 * (LE). If it returns the multi-byte values in host-endian format,
+	 * set the host_endian output parameter to "1".
+	 *
+	 * Return 0 on success or a LIBUSB_ERROR code on failure.
+	 */
+	int (*get_config_descriptor)(struct libusb_device *device,
+		uint8_t config_index, unsigned char *buffer, size_t len,
+		int *host_endian);
+
+	/* Get the bConfigurationValue for the active configuration for a device.
+	 * Optional. This should only be implemented if you can retrieve it from
+	 * cache (don't generate I/O).
+	 *
+	 * If you cannot retrieve this from cache, either do not implement this
+	 * function, or return LIBUSB_ERROR_NOT_SUPPORTED. This will cause
+	 * libusb to retrieve the information through a standard control transfer.
+	 *
+	 * This function must be non-blocking.
+	 * Return:
+	 * - 0 on success
+	 * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it
+	 *   was opened
+	 * - LIBUSB_ERROR_NOT_SUPPORTED if the value cannot be retrieved without
+	 *   blocking
+	 * - another LIBUSB_ERROR code on other failure.
+	 */
+	int (*get_configuration)(struct libusb_device_handle *handle, int *config);
+
+	/* Set the active configuration for a device.
+	 *
+	 * A configuration value of -1 should put the device in unconfigured state.
+	 *
+	 * This function can block.
+	 *
+	 * Return:
+	 * - 0 on success
+	 * - LIBUSB_ERROR_NOT_FOUND if the configuration does not exist
+	 * - LIBUSB_ERROR_BUSY if interfaces are currently claimed (and hence
+	 *   configuration cannot be changed)
+	 * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it
+	 *   was opened
+	 * - another LIBUSB_ERROR code on other failure.
+	 */
+	int (*set_configuration)(struct libusb_device_handle *handle, int config);
+
+	/* Claim an interface. When claimed, the application can then perform
+	 * I/O to an interface's endpoints.
+	 *
+	 * This function should not generate any bus I/O and should not block.
+	 * Interface claiming is a logical operation that simply ensures that
+	 * no other drivers/applications are using the interface, and after
+	 * claiming, no other drivers/applicatiosn can use the interface because
+	 * we now "own" it.
+	 *
+	 * Return:
+	 * - 0 on success
+	 * - LIBUSB_ERROR_NOT_FOUND if the interface does not exist
+	 * - LIBUSB_ERROR_BUSY if the interface is in use by another driver/app
+	 * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it
+	 *   was opened
+	 * - another LIBUSB_ERROR code on other failure
+	 */
+	int (*claim_interface)(struct libusb_device_handle *handle, int interface_number);
+
+	/* Release a previously claimed interface.
+	 *
+	 * This function should also generate a SET_INTERFACE control request,
+	 * resetting the alternate setting of that interface to 0. It's OK for
+	 * this function to block as a result.
+	 *
+	 * You will only ever be asked to release an interface which was
+	 * successfully claimed earlier.
+	 *
+	 * Return:
+	 * - 0 on success
+	 * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it
+	 *   was opened
+	 * - another LIBUSB_ERROR code on other failure
+	 */
+	int (*release_interface)(struct libusb_device_handle *handle, int interface_number);
+
+	/* Set the alternate setting for an interface.
+	 *
+	 * You will only ever be asked to set the alternate setting for an
+	 * interface which was successfully claimed earlier.
+	 *
+	 * It's OK for this function to block.
+	 *
+	 * Return:
+	 * - 0 on success
+	 * - LIBUSB_ERROR_NOT_FOUND if the alternate setting does not exist
+	 * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it
+	 *   was opened
+	 * - another LIBUSB_ERROR code on other failure
+	 */
+	int (*set_interface_altsetting)(struct libusb_device_handle *handle,
+		int interface_number, int altsetting);
+
+	/* Clear a halt/stall condition on an endpoint.
+	 *
+	 * It's OK for this function to block.
+	 *
+	 * Return:
+	 * - 0 on success
+	 * - LIBUSB_ERROR_NOT_FOUND if the endpoint does not exist
+	 * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it
+	 *   was opened
+	 * - another LIBUSB_ERROR code on other failure
+	 */
+	int (*clear_halt)(struct libusb_device_handle *handle,
+		unsigned char endpoint);
+
+	/* Perform a USB port reset to reinitialize a device.
+	 *
+	 * If possible, the handle should still be usable after the reset
+	 * completes, assuming that the device descriptors did not change during
+	 * reset and all previous interface state can be restored.
+	 *
+	 * If something changes, or you cannot easily locate/verify the resetted
+	 * device, return LIBUSB_ERROR_NOT_FOUND. This prompts the application
+	 * to close the old handle and re-enumerate the device.
+	 *
+	 * Return:
+	 * - 0 on success
+	 * - LIBUSB_ERROR_NOT_FOUND if re-enumeration is required, or if the device
+	 *   has been disconnected since it was opened
+	 * - another LIBUSB_ERROR code on other failure
+	 */
+	int (*reset_device)(struct libusb_device_handle *handle);
+
+	/* Determine if a kernel driver is active on an interface. Optional.
+	 *
+	 * The presence of a kernel driver on an interface indicates that any
+	 * calls to claim_interface would fail with the LIBUSB_ERROR_BUSY code.
+	 *
+	 * Return:
+	 * - 0 if no driver is active
+	 * - 1 if a driver is active
+	 * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it
+	 *   was opened
+	 * - another LIBUSB_ERROR code on other failure
+	 */
+	int (*kernel_driver_active)(struct libusb_device_handle *handle,
+		int interface_number);
+
+	/* Detach a kernel driver from an interface. Optional.
+	 *
+	 * After detaching a kernel driver, the interface should be available
+	 * for claim.
+	 *
+	 * Return:
+	 * - 0 on success
+	 * - LIBUSB_ERROR_NOT_FOUND if no kernel driver was active
+	 * - LIBUSB_ERROR_INVALID_PARAM if the interface does not exist
+	 * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it
+	 *   was opened
+	 * - another LIBUSB_ERROR code on other failure
+	 */
+	int (*detach_kernel_driver)(struct libusb_device_handle *handle,
+		int interface_number);
+
+	/* Attach a kernel driver to an interface. Optional.
+	 *
+	 * Reattach a kernel driver to the device.
+	 *
+	 * Return:
+	 * - 0 on success
+	 * - LIBUSB_ERROR_NOT_FOUND if no kernel driver was active
+	 * - LIBUSB_ERROR_INVALID_PARAM if the interface does not exist
+	 * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it
+	 *   was opened
+	 * - LIBUSB_ERROR_BUSY if a program or driver has claimed the interface,
+	 *   preventing reattachment
+	 * - another LIBUSB_ERROR code on other failure
+	 */
+	int (*attach_kernel_driver)(struct libusb_device_handle *handle,
+		int interface_number);
+
+	/* Destroy a device. Optional.
+	 *
+	 * This function is called when the last reference to a device is
+	 * destroyed. It should free any resources allocated in the get_device_list
+	 * path.
+	 */
+	void (*destroy_device)(struct libusb_device *dev);
+
+	/* Submit a transfer. Your implementation should take the transfer,
+	 * morph it into whatever form your platform requires, and submit it
+	 * asynchronously.
+	 *
+	 * This function must not block.
+	 *
+	 * Return:
+	 * - 0 on success
+	 * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected
+	 * - another LIBUSB_ERROR code on other failure
+	 */
+	int (*submit_transfer)(struct usbi_transfer *itransfer);
+
+	/* Cancel a previously submitted transfer.
+	 *
+	 * This function must not block. The transfer cancellation must complete
+	 * later, resulting in a call to usbi_handle_transfer_cancellation()
+	 * from the context of handle_events.
+	 */
+	int (*cancel_transfer)(struct usbi_transfer *itransfer);
+
+	/* Clear a transfer as if it has completed or cancelled, but do not
+	 * report any completion/cancellation to the library. You should free
+	 * all private data from the transfer as if you were just about to report
+	 * completion or cancellation.
+	 *
+	 * This function might seem a bit out of place. It is used when libusb
+	 * detects a disconnected device - it calls this function for all pending
+	 * transfers before reporting completion (with the disconnect code) to
+	 * the user. Maybe we can improve upon this internal interface in future.
+	 */
+	void (*clear_transfer_priv)(struct usbi_transfer *itransfer);
+
+	/* Handle any pending events. This involves monitoring any active
+	 * transfers and processing their completion or cancellation.
+	 *
+	 * The function is passed an array of pollfd structures (size nfds)
+	 * as a result of the poll() system call. The num_ready parameter
+	 * indicates the number of file descriptors that have reported events
+	 * (i.e. the poll() return value). This should be enough information
+	 * for you to determine which actions need to be taken on the currently
+	 * active transfers.
+	 *
+	 * For any cancelled transfers, call usbi_handle_transfer_cancellation().
+	 * For completed transfers, call usbi_handle_transfer_completion().
+	 * For control/bulk/interrupt transfers, populate the "transferred"
+	 * element of the appropriate usbi_transfer structure before calling the
+	 * above functions. For isochronous transfers, populate the status and
+	 * transferred fields of the iso packet descriptors of the transfer.
+	 *
+	 * This function should also be able to detect disconnection of the
+	 * device, reporting that situation with usbi_handle_disconnect().
+	 *
+	 * When processing an event related to a transfer, you probably want to
+	 * take usbi_transfer.lock to prevent races. See the documentation for
+	 * the usbi_transfer structure.
+	 *
+	 * Return 0 on success, or a LIBUSB_ERROR code on failure.
+	 */
+	int (*handle_events)(struct libusb_context *ctx,
+		struct pollfd *fds, nfds_t nfds, int num_ready);
+
+	/* Get time from specified clock. At least two clocks must be implemented
+	   by the backend: USBI_CLOCK_REALTIME, and USBI_CLOCK_MONOTONIC.
+
+	   Description of clocks:
+	     USBI_CLOCK_REALTIME : clock returns time since system epoch.
+	     USBI_CLOCK_MONOTONIC: clock returns time since unspecified start
+	                             time (usually boot).
+	 */
+	int (*clock_gettime)(int clkid, struct timespec *tp);
+
+#ifdef USBI_TIMERFD_AVAILABLE
+	/* clock ID of the clock that should be used for timerfd */
+	clockid_t (*get_timerfd_clockid)(void);
+#endif
+
+	/* Number of bytes to reserve for per-device private backend data.
+	 * This private data area is accessible through the "os_priv" field of
+	 * struct libusb_device. */
+	size_t device_priv_size;
+
+	/* Number of bytes to reserve for per-handle private backend data.
+	 * This private data area is accessible through the "os_priv" field of
+	 * struct libusb_device. */
+	size_t device_handle_priv_size;
+
+	/* Number of bytes to reserve for per-transfer private backend data.
+	 * This private data area is accessible by calling
+	 * usbi_transfer_get_os_priv() on the appropriate usbi_transfer instance.
+	 */
+	size_t transfer_priv_size;
+
+	/* Mumber of additional bytes for os_priv for each iso packet.
+	 * Can your backend use this? */
+	/* FIXME: linux can't use this any more. if other OS's cannot either,
+	 * then remove this */
+	size_t add_iso_packet_size;
+};
+
+extern const struct usbi_os_backend * const usbi_backend;
+
+extern const struct usbi_os_backend linux_usbfs_backend;
+extern const struct usbi_os_backend darwin_backend;
+extern const struct usbi_os_backend windows_backend;
+
+#endif
+
diff --git a/include/libusb-1.0/os/config.h b/include/libusb-1.0/os/config.h
new file mode 100644
index 0000000..643d4af
--- /dev/null
+++ b/include/libusb-1.0/os/config.h
@@ -0,0 +1,105 @@
+/* config.h.  Generated from config.h.in by configure.  */
+/* config.h.in.  Generated from configure.ac by autoheader.  */
+
+/* Default visibility */
+#define DEFAULT_VISIBILITY __attribute__((visibility("default")))
+
+/* Debug message logging */
+/* #undef ENABLE_DEBUG_LOGGING */
+
+/* Message logging */
+#define ENABLE_LOGGING 1
+
+/* Define to 1 if you have the <dlfcn.h> header file. */
+#define HAVE_DLFCN_H 1
+
+/* Define to 1 if you have the <inttypes.h> header file. */
+#define HAVE_INTTYPES_H 1
+
+/* Define to 1 if you have the <memory.h> header file. */
+#define HAVE_MEMORY_H 1
+
+/* Define to 1 if you have the <stdint.h> header file. */
+#define HAVE_STDINT_H 1
+
+/* Define to 1 if you have the <stdlib.h> header file. */
+#define HAVE_STDLIB_H 1
+
+/* Define to 1 if you have the <strings.h> header file. */
+#define HAVE_STRINGS_H 1
+
+/* Define to 1 if you have the <string.h> header file. */
+#define HAVE_STRING_H 1
+
+/* Define to 1 if the system has the type `struct timespec'. */
+#define HAVE_STRUCT_TIMESPEC 1
+
+/* Define to 1 if you have the <sys/stat.h> header file. */
+#define HAVE_SYS_STAT_H 1
+
+/* Define to 1 if you have the <sys/time.h> header file. */
+#define HAVE_SYS_TIME_H 1
+
+/* Define to 1 if you have the <sys/types.h> header file. */
+#define HAVE_SYS_TYPES_H 1
+
+/* Define to 1 if you have the <unistd.h> header file. */
+#define HAVE_UNISTD_H 1
+
+/* Define to the sub-directory in which libtool stores uninstalled libraries.
+   */
+#define LT_OBJDIR ".libs/"
+
+/* Define to 1 if your C compiler doesn't accept -c and -o together. */
+/* #undef NO_MINUS_C_MINUS_O */
+
+/* Darwin backend */
+#define OS_DARWIN 
+
+/* Linux backend */
+/* #undef OS_LINUX */
+
+/* Windows backend */
+/* #undef OS_WINDOWS */
+
+/* Name of package */
+#define PACKAGE "libusb"
+
+/* Define to the address where bug reports for this package should be sent. */
+#define PACKAGE_BUGREPORT "libusb-devel@lists.sourceforge.net"
+
+/* Define to the full name of this package. */
+#define PACKAGE_NAME "libusb"
+
+/* Define to the full name and version of this package. */
+#define PACKAGE_STRING "libusb 1.0.8"
+
+/* Define to the one symbol short name of this package. */
+#define PACKAGE_TARNAME "libusb"
+
+/* Define to the version of this package. */
+#define PACKAGE_VERSION "1.0.8"
+
+/* Define to 1 if you have the ANSI C header files. */
+#define STDC_HEADERS 1
+
+/* Use Posix Threads */
+#define THREADS_POSIX 
+
+/* Backend handles timeout */
+#define USBI_OS_HANDLES_TIMEOUT 
+
+/* timerfd headers available */
+/* #undef USBI_TIMERFD_AVAILABLE */
+
+/* Version number of package */
+#define VERSION "1.0.8"
+
+/* Use GNU extensions */
+#define _GNU_SOURCE 
+
+/* Define to `__inline__' or `__inline' if that's what the C compiler
+   calls it, or to nothing if 'inline' is not supported under any name.  */
+#ifndef __cplusplus
+/* #undef inline */
+#endif
diff --git a/include/libusb-1.0/os/darwin_usb.c b/include/libusb-1.0/os/darwin_usb.c
new file mode 100644
index 0000000..646c938
--- /dev/null
+++ b/include/libusb-1.0/os/darwin_usb.c
@@ -0,0 +1,1545 @@
+/*
+ * darwin backend for libusb 1.0
+ * Copyright (C) 2008-2010 Nathan Hjelm <hjelmn@users.sourceforge.net>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <config.h>
+#include <ctype.h>
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <mach/clock.h>
+#include <mach/clock_types.h>
+#include <mach/mach_host.h>
+
+#include <mach/mach_port.h>
+#include <IOKit/IOCFBundle.h>
+#include <IOKit/usb/IOUSBLib.h>
+#include <IOKit/IOCFPlugIn.h>
+
+#include "darwin_usb.h"
+
+static mach_port_t  libusb_darwin_mp = 0; /* master port */
+static CFRunLoopRef libusb_darwin_acfl = NULL; /* async cf loop */
+static int initCount = 0;
+
+/* async event thread */
+static pthread_t libusb_darwin_at;
+
+static int darwin_get_config_descriptor(struct libusb_device *dev, uint8_t config_index, unsigned char *buffer, size_t len, int *host_endian);
+static int darwin_claim_interface(struct libusb_device_handle *dev_handle, int iface);
+static int darwin_release_interface(struct libusb_device_handle *dev_handle, int iface);
+static int darwin_reset_device(struct libusb_device_handle *dev_handle);
+static void darwin_async_io_callback (void *refcon, IOReturn result, void *arg0);
+
+static const char *darwin_error_str (int result) {
+  switch (result) {
+  case kIOReturnSuccess:
+    return "no error";
+  case kIOReturnNotOpen:
+    return "device not opened for exclusive access";
+  case kIOReturnNoDevice:
+    return "no connection to an IOService";
+  case kIOUSBNoAsyncPortErr:
+    return "no async port has been opened for interface";
+  case kIOReturnExclusiveAccess:
+    return "another process has device opened for exclusive access";
+  case kIOUSBPipeStalled:
+    return "pipe is stalled";
+  case kIOReturnError:
+    return "could not establish a connection to the Darwin kernel";
+  case kIOUSBTransactionTimeout:
+    return "transaction timed out";
+  case kIOReturnBadArgument:
+    return "invalid argument";
+  case kIOReturnAborted:
+    return "transaction aborted";
+  case kIOReturnNotResponding:
+    return "device not responding";
+  case kIOReturnOverrun:
+    return "data overrun";
+  case kIOReturnCannotWire:
+    return "physical memory can not be wired down";
+  default:
+    return "unknown error";
+  }
+}
+
+static int darwin_to_libusb (int result) {
+  switch (result) {
+  case kIOReturnUnderrun:
+  case kIOReturnSuccess:
+    return LIBUSB_SUCCESS;
+  case kIOReturnNotOpen:
+  case kIOReturnNoDevice:
+    return LIBUSB_ERROR_NO_DEVICE;
+  case kIOReturnExclusiveAccess:
+    return LIBUSB_ERROR_ACCESS;
+  case kIOUSBPipeStalled:
+    return LIBUSB_ERROR_PIPE;
+  case kIOReturnBadArgument:
+    return LIBUSB_ERROR_INVALID_PARAM;
+  case kIOUSBTransactionTimeout:
+    return LIBUSB_ERROR_TIMEOUT;
+  case kIOReturnNotResponding:
+  case kIOReturnAborted:
+  case kIOReturnError:
+  case kIOUSBNoAsyncPortErr:
+  default:
+    return LIBUSB_ERROR_OTHER;
+  }
+}
+
+
+static int ep_to_pipeRef(struct libusb_device_handle *dev_handle, uint8_t ep, uint8_t *pipep, uint8_t *ifcp) {
+  struct darwin_device_handle_priv *priv = (struct darwin_device_handle_priv *)dev_handle->os_priv;
+
+  /* current interface */
+  struct __darwin_interface *cInterface;
+
+  int8_t i, iface;
+
+  usbi_info (HANDLE_CTX(dev_handle), "converting ep address 0x%02x to pipeRef and interface", ep);
+
+  for (iface = 0 ; iface < USB_MAXINTERFACES ; iface++) {
+    cInterface = &priv->interfaces[iface];
+
+    if (dev_handle->claimed_interfaces & (1 << iface)) {
+      for (i = 0 ; i < cInterface->num_endpoints ; i++) {
+	if (cInterface->endpoint_addrs[i] == ep) {
+	  *pipep = i + 1;
+	  *ifcp = iface;
+	  usbi_info (HANDLE_CTX(dev_handle), "pipe %d on interface %d matches", *pipep, *ifcp);
+	  return 0;
+	}
+      }
+    }
+  }
+
+  /* No pipe found with the correct endpoint address */
+  usbi_warn (HANDLE_CTX(dev_handle), "no pipeRef found with endpoint address 0x%02x.", ep);
+
+  return -1;
+}
+
+static int usb_setup_device_iterator (io_iterator_t *deviceIterator) {
+  return IOServiceGetMatchingServices(libusb_darwin_mp, IOServiceMatching(kIOUSBDeviceClassName), deviceIterator);
+}
+
+static usb_device_t **usb_get_next_device (io_iterator_t deviceIterator, UInt32 *locationp) {
+  io_cf_plugin_ref_t *plugInInterface = NULL;
+  usb_device_t **device;
+  io_service_t usbDevice;
+  long result;
+  SInt32 score;
+
+  if (!IOIteratorIsValid (deviceIterator))
+    return NULL;
+
+
+  while ((usbDevice = IOIteratorNext(deviceIterator))) {
+    result = IOCreatePlugInInterfaceForService(usbDevice, kIOUSBDeviceUserClientTypeID,
+					       kIOCFPlugInInterfaceID, &plugInInterface,
+					       &score);
+    if (kIOReturnSuccess == result && plugInInterface)
+      break;
+
+    usbi_dbg ("libusb/darwin.c usb_get_next_device: could not set up plugin for service: %s\n", darwin_error_str (result));
+  }
+
+  if (!usbDevice)
+    return NULL;
+
+  (void)IOObjectRelease(usbDevice);
+  (void)(*plugInInterface)->QueryInterface(plugInInterface, CFUUIDGetUUIDBytes(DeviceInterfaceID),
+					   (LPVOID)&device);
+
+  (*plugInInterface)->Stop(plugInInterface);
+  IODestroyPlugInInterface (plugInInterface);
+
+  /* get the location from the device */
+  if (locationp)
+    (*(device))->GetLocationID(device, locationp);
+
+  return device;
+}
+
+static kern_return_t darwin_get_device (uint32_t dev_location, usb_device_t ***darwin_device) {
+  kern_return_t kresult;
+  UInt32        location;
+  io_iterator_t deviceIterator;
+
+  kresult = usb_setup_device_iterator (&deviceIterator);
+  if (kresult)
+    return kresult;
+
+  /* This port of libusb uses locations to keep track of devices. */
+  while ((*darwin_device = usb_get_next_device (deviceIterator, &location)) != NULL) {
+    if (location == dev_location)
+      break;
+
+    (**darwin_device)->Release(*darwin_device);
+  }
+
+  IOObjectRelease (deviceIterator);
+
+  if (!(*darwin_device))
+    return kIOReturnNoDevice;
+
+  return kIOReturnSuccess;
+}
+
+
+
+static void darwin_devices_detached (void *ptr, io_iterator_t rem_devices) {
+  struct libusb_context *ctx = (struct libusb_context *)ptr;
+  struct libusb_device_handle *handle;
+  struct darwin_device_priv *dpriv;
+  struct darwin_device_handle_priv *priv;
+
+  io_service_t device;
+  long location;
+  CFTypeRef locationCF;
+  UInt32 message;
+
+  usbi_info (ctx, "a device has been detached");
+
+  while ((device = IOIteratorNext (rem_devices)) != 0) {
+    /* get the location from the i/o registry */
+    locationCF = IORegistryEntryCreateCFProperty (device, CFSTR(kUSBDevicePropertyLocationID), kCFAllocatorDefault, 0);
+
+    CFNumberGetValue(locationCF, kCFNumberLongType, &location);
+    CFRelease (locationCF);
+    IOObjectRelease (device);
+
+    usbi_mutex_lock(&ctx->open_devs_lock);
+    list_for_each_entry(handle, &ctx->open_devs, list, struct libusb_device_handle) {
+      dpriv = (struct darwin_device_priv *)handle->dev->os_priv;
+
+      /* the device may have been opened several times. write to each handle's event descriptor */
+      if (dpriv->location == location  && handle->os_priv) {
+	priv  = (struct darwin_device_handle_priv *)handle->os_priv;
+
+	message = MESSAGE_DEVICE_GONE;
+	write (priv->fds[1], &message, sizeof (message));
+      }
+    }
+
+    usbi_mutex_unlock(&ctx->open_devs_lock);
+  }
+}
+
+static void darwin_clear_iterator (io_iterator_t iter) {
+  io_service_t device;
+
+  while ((device = IOIteratorNext (iter)) != 0)
+    IOObjectRelease (device);
+}
+
+static void *event_thread_main (void *arg0) {
+  IOReturn kresult;
+  struct libusb_context *ctx = (struct libusb_context *)arg0;
+
+  /* hotplug (device removal) source */
+  CFRunLoopSourceRef     libusb_notification_cfsource;
+  io_notification_port_t libusb_notification_port;
+  io_iterator_t          libusb_rem_device_iterator;
+
+  usbi_info (ctx, "creating hotplug event source");
+
+  CFRetain (CFRunLoopGetCurrent ());
+
+  /* add the notification port to the run loop */
+  libusb_notification_port     = IONotificationPortCreate (libusb_darwin_mp);
+  libusb_notification_cfsource = IONotificationPortGetRunLoopSource (libusb_notification_port);
+  CFRunLoopAddSource(CFRunLoopGetCurrent (), libusb_notification_cfsource, kCFRunLoopDefaultMode);
+
+  /* create notifications for removed devices */
+  kresult = IOServiceAddMatchingNotification (libusb_notification_port, kIOTerminatedNotification,
+					      IOServiceMatching(kIOUSBDeviceClassName),
+					      (IOServiceMatchingCallback)darwin_devices_detached,
+					      (void *)ctx, &libusb_rem_device_iterator);
+
+  if (kresult != kIOReturnSuccess) {
+    usbi_err (ctx, "could not add hotplug event source: %s", darwin_error_str (kresult));
+
+    pthread_exit ((void *)kresult);
+  }
+
+  /* arm notifiers */
+  darwin_clear_iterator (libusb_rem_device_iterator);
+
+  /* let the main thread know about the async runloop */
+  libusb_darwin_acfl = CFRunLoopGetCurrent ();
+
+  usbi_info (ctx, "thread ready to receive events");
+
+  /* run the runloop */
+  CFRunLoopRun();
+
+  usbi_info (ctx, "thread exiting");
+
+  /* delete notification port */
+  CFRunLoopSourceInvalidate (libusb_notification_cfsource);
+  IONotificationPortDestroy (libusb_notification_port);
+
+  CFRelease (CFRunLoopGetCurrent ());
+
+  libusb_darwin_acfl = NULL;
+
+  pthread_exit (0);
+}
+
+static int darwin_init(struct libusb_context *ctx) {
+  IOReturn kresult;
+
+  if (!(initCount++)) {
+    /* Create the master port for talking to IOKit */
+    if (!libusb_darwin_mp) {
+      kresult = IOMasterPort (MACH_PORT_NULL, &libusb_darwin_mp);
+
+      if (kresult != kIOReturnSuccess || !libusb_darwin_mp)
+	return darwin_to_libusb (kresult);
+    }
+
+    pthread_create (&libusb_darwin_at, NULL, event_thread_main, (void *)ctx);
+
+    while (!libusb_darwin_acfl)
+      usleep (10);
+  }
+
+  return 0;
+}
+
+static void darwin_exit (void) {
+  if (!(--initCount)) {
+    void *ret;
+
+    /* stop the async runloop */
+    CFRunLoopStop (libusb_darwin_acfl);
+    pthread_join (libusb_darwin_at, &ret);
+
+    if (libusb_darwin_mp)
+      mach_port_deallocate(mach_task_self(), libusb_darwin_mp);
+
+    libusb_darwin_mp = 0;
+  }
+}
+
+static int darwin_get_device_descriptor(struct libusb_device *dev, unsigned char *buffer, int *host_endian) {
+  struct darwin_device_priv *priv = (struct darwin_device_priv *)dev->os_priv;
+
+  /* return cached copy */
+  memmove (buffer, &(priv->dev_descriptor), DEVICE_DESC_LENGTH);
+
+  *host_endian = 0;
+
+  return 0;
+}
+
+static int get_configuration_index (struct libusb_device *dev, int config_value) {
+  struct darwin_device_priv *priv = (struct darwin_device_priv *)dev->os_priv;
+  UInt8 i, numConfig;
+  IOUSBConfigurationDescriptorPtr desc;
+  IOReturn kresult;
+
+  /* is there a simpler way to determine the index? */
+  kresult = (*(priv->device))->GetNumberOfConfigurations (priv->device, &numConfig);
+  if (kresult != kIOReturnSuccess)
+    return darwin_to_libusb (kresult);
+
+  for (i = 0 ; i < numConfig ; i++) {
+    (*(priv->device))->GetConfigurationDescriptorPtr (priv->device, i, &desc);
+
+    if (desc->bConfigurationValue == config_value)
+      return i;
+  }
+
+  /* configuration not found */
+  return LIBUSB_ERROR_OTHER;
+}
+
+static int darwin_get_active_config_descriptor(struct libusb_device *dev, unsigned char *buffer, size_t len, int *host_endian) {
+  struct darwin_device_priv *priv = (struct darwin_device_priv *)dev->os_priv;
+  int config_index;
+
+  if (0 == priv->active_config)
+    return LIBUSB_ERROR_INVALID_PARAM;
+
+  config_index = get_configuration_index (dev, priv->active_config);
+  if (config_index < 0)
+    return config_index;
+
+  return darwin_get_config_descriptor (dev, config_index, buffer, len, host_endian);
+}
+
+static int darwin_get_config_descriptor(struct libusb_device *dev, uint8_t config_index, unsigned char *buffer, size_t len, int *host_endian) {
+  struct darwin_device_priv *priv = (struct darwin_device_priv *)dev->os_priv;
+  IOUSBConfigurationDescriptorPtr desc;
+  IOReturn kresult;
+  usb_device_t **device = NULL;
+
+  if (!priv)
+    return LIBUSB_ERROR_OTHER;
+
+  if (!priv->device) {
+    kresult = darwin_get_device (priv->location, &device);
+    if (kresult || !device) {
+      usbi_err (DEVICE_CTX (dev), "could not find device: %s", darwin_error_str (kresult));
+
+      return darwin_to_libusb (kresult);
+    }
+
+    /* don't have to open the device to get a config descriptor */
+  } else
+    device = priv->device;
+
+  kresult = (*device)->GetConfigurationDescriptorPtr (device, config_index, &desc);
+  if (kresult == kIOReturnSuccess) {
+    /* copy descriptor */
+    if (libusb_le16_to_cpu(desc->wTotalLength) < len)
+      len = libusb_le16_to_cpu(desc->wTotalLength);
+
+    memmove (buffer, desc, len);
+
+    /* GetConfigurationDescriptorPtr returns the descriptor in USB bus order */
+    *host_endian = 0;
+  }
+
+  if (!priv->device)
+    (*device)->Release (device);
+
+  return darwin_to_libusb (kresult);
+}
+
+/* check whether the os has configured the device */
+static int darwin_check_configuration (struct libusb_context *ctx, struct libusb_device *dev, usb_device_t **darwin_device) {
+  struct darwin_device_priv *priv = (struct darwin_device_priv *)dev->os_priv;
+
+  IOUSBConfigurationDescriptorPtr configDesc;
+  IOUSBFindInterfaceRequest request;
+  kern_return_t             kresult;
+  io_iterator_t             interface_iterator;
+  io_service_t              firstInterface;
+
+  if (priv->dev_descriptor.bNumConfigurations < 1) {
+    usbi_err (ctx, "device has no configurations");
+    return LIBUSB_ERROR_OTHER; /* no configurations at this speed so we can't use it */
+  }
+
+  /* find the first configuration */
+  kresult = (*darwin_device)->GetConfigurationDescriptorPtr (darwin_device, 0, &configDesc);
+  priv->first_config = (kIOReturnSuccess == kresult) ? configDesc->bConfigurationValue : 1;
+
+  /* check if the device is already configured. there is probably a better way than iterating over the
+     to accomplish this (the trick is we need to avoid a call to GetConfigurations since buggy devices
+     might lock up on the device request) */
+
+  /* Setup the Interface Request */
+  request.bInterfaceClass    = kIOUSBFindInterfaceDontCare;
+  request.bInterfaceSubClass = kIOUSBFindInterfaceDontCare;
+  request.bInterfaceProtocol = kIOUSBFindInterfaceDontCare;
+  request.bAlternateSetting  = kIOUSBFindInterfaceDontCare;
+
+  kresult = (*(darwin_device))->CreateInterfaceIterator(darwin_device, &request, &interface_iterator);
+  if (kresult)
+    return darwin_to_libusb (kresult);
+
+  /* iterate once */
+  firstInterface = IOIteratorNext(interface_iterator);
+
+  /* done with the interface iterator */
+  IOObjectRelease(interface_iterator);
+
+  if (firstInterface) {
+    IOObjectRelease (firstInterface);
+
+    /* device is configured */
+    if (priv->dev_descriptor.bNumConfigurations == 1)
+      /* to avoid problems with some devices get the configurations value from the configuration descriptor */
+      priv->active_config = priv->first_config;
+    else
+      /* devices with more than one configuration should work with GetConfiguration */
+      (*darwin_device)->GetConfiguration (darwin_device, &priv->active_config);
+  } else
+    /* not configured */
+    priv->active_config = 0;
+  
+  usbi_info (ctx, "active config: %u, first config: %u", priv->active_config, priv->first_config);
+
+  return 0;
+}
+
+static int process_new_device (struct libusb_context *ctx, usb_device_t **device, UInt32 locationID, struct discovered_devs **_discdevs) {
+  struct darwin_device_priv *priv;
+  struct libusb_device *dev;
+  struct discovered_devs *discdevs;
+  UInt16                address, idVendor, idProduct;
+  UInt8                 bDeviceClass, bDeviceSubClass;
+  IOUSBDevRequest      req;
+  int ret = 0, need_unref = 0;
+
+  do {
+    dev = usbi_get_device_by_session_id(ctx, locationID);
+    if (!dev) {
+      usbi_info (ctx, "allocating new device for location 0x%08x", locationID);
+      dev = usbi_alloc_device(ctx, locationID);
+      need_unref = 1;
+    } else
+      usbi_info (ctx, "using existing device for location 0x%08x", locationID);
+
+    if (!dev) {
+      ret = LIBUSB_ERROR_NO_MEM;
+      break;
+    }
+
+    priv = (struct darwin_device_priv *)dev->os_priv;
+
+    /* Set up request for device descriptor */
+    req.bmRequestType = USBmakebmRequestType(kUSBIn, kUSBStandard, kUSBDevice);
+    req.bRequest      = kUSBRqGetDescriptor;
+    req.wValue        = kUSBDeviceDesc << 8;
+    req.wIndex        = 0;
+    req.wLength       = sizeof(IOUSBDeviceDescriptor);
+    req.pData         = &(priv->dev_descriptor);
+
+    (*(device))->GetDeviceAddress (device, (USBDeviceAddress *)&address);
+    (*(device))->GetDeviceProduct (device, &idProduct);
+    (*(device))->GetDeviceVendor (device, &idVendor);
+    (*(device))->GetDeviceClass (device, &bDeviceClass);
+    (*(device))->GetDeviceSubClass (device, &bDeviceSubClass);
+
+    /**** retrieve device descriptors ****/
+    /* according to Apple's documentation the device must be open for DeviceRequest but we may not be able to open some
+     * devices and Apple's USB Prober doesn't bother to open the device before issuing a descriptor request */
+    ret = (*(device))->DeviceRequest (device, &req);
+    if (ret != kIOReturnSuccess) {
+      int try_unsuspend = 1;
+#if DeviceVersion >= 320
+      UInt32 info;
+
+      /* device may be suspended. unsuspend it and try again */
+      /* IOUSBFamily 320+ provides a way to detect device suspension but earlier versions do not */
+      (void)(*device)->GetUSBDeviceInformation (device, &info);
+
+      try_unsuspend = info & (1 << kUSBInformationDeviceIsSuspendedBit);
+#endif
+
+      /* the device should be open before to device is unsuspended */
+      (void) (*device)->USBDeviceOpenSeize(device);
+
+      if (try_unsuspend) {
+	/* resume the device */
+	(void)(*device)->USBDeviceSuspend (device, 0);
+
+	ret = (*(device))->DeviceRequest (device, &req);
+
+	/* resuspend the device */
+	(void)(*device)->USBDeviceSuspend (device, 1);
+      }
+
+      (*device)->USBDeviceClose (device);
+    }
+
+    if (ret != kIOReturnSuccess) {
+      usbi_warn (ctx, "could not retrieve device descriptor: %s. skipping device", darwin_error_str (ret));
+      ret = -1;
+      break;
+    }
+
+    /**** end: retrieve device descriptors ****/
+
+    /* catch buggy hubs (which appear to be virtual). Apple's own USB prober has problems with these devices. */
+    if (libusb_le16_to_cpu (priv->dev_descriptor.idProduct) != idProduct) {
+      /* not a valid device */
+      usbi_warn (ctx, "idProduct from iokit (%04x) does not match idProduct in descriptor (%04x). skipping device",
+		 idProduct, libusb_le16_to_cpu (priv->dev_descriptor.idProduct));
+      ret = -1;
+      break;
+    }
+
+    dev->bus_number     = locationID >> 24;
+    dev->device_address = address;
+
+    /* check current active configuration (and cache the first configuration value-- which may be used by claim_interface) */
+    ret = darwin_check_configuration (ctx, dev, device);
+    if (ret < 0)
+      break;
+
+    /* save our location, we'll need this later */
+    priv->location = locationID;
+    snprintf(priv->sys_path, 20, "%03i-%04x-%04x-%02x-%02x", address, idVendor, idProduct, bDeviceClass, bDeviceSubClass);
+
+    ret = usbi_sanitize_device (dev);
+    if (ret < 0)
+      break;
+
+    /* append the device to the list of discovered devices */
+    discdevs = discovered_devs_append(*_discdevs, dev);
+    if (!discdevs) {
+      ret = LIBUSB_ERROR_NO_MEM;
+      break;
+    }
+
+    *_discdevs = discdevs;
+
+    usbi_info (ctx, "found device with address %d at %s", dev->device_address, priv->sys_path);
+  } while (0);
+
+  if (need_unref)
+    libusb_unref_device(dev);
+
+  return ret;
+}
+
+static int darwin_get_device_list(struct libusb_context *ctx, struct discovered_devs **_discdevs) {
+  io_iterator_t        deviceIterator;
+  usb_device_t         **device;
+  kern_return_t        kresult;
+  UInt32               location;
+
+  if (!libusb_darwin_mp)
+    return LIBUSB_ERROR_INVALID_PARAM;
+
+  kresult = usb_setup_device_iterator (&deviceIterator);
+  if (kresult != kIOReturnSuccess)
+    return darwin_to_libusb (kresult);
+
+  while ((device = usb_get_next_device (deviceIterator, &location)) != NULL) {
+    (void) process_new_device (ctx, device, location, _discdevs);
+
+    (*(device))->Release(device);
+  }
+
+  IOObjectRelease(deviceIterator);
+
+  return 0;
+}
+
+static int darwin_open (struct libusb_device_handle *dev_handle) {
+  struct darwin_device_handle_priv *priv = (struct darwin_device_handle_priv *)dev_handle->os_priv;
+  struct darwin_device_priv *dpriv = (struct darwin_device_priv *)dev_handle->dev->os_priv;
+  usb_device_t  **darwin_device;
+  IOReturn kresult;
+
+  if (0 == dpriv->open_count) {
+    kresult = darwin_get_device (dpriv->location, &darwin_device);
+    if (kresult) {
+      usbi_err (HANDLE_CTX (dev_handle), "could not find device: %s", darwin_error_str (kresult));
+      return darwin_to_libusb (kresult);
+    }
+
+    dpriv->device = darwin_device;
+
+    /* try to open the device */
+    kresult = (*(dpriv->device))->USBDeviceOpenSeize (dpriv->device);
+
+    if (kresult != kIOReturnSuccess) {
+      usbi_err (HANDLE_CTX (dev_handle), "USBDeviceOpen: %s", darwin_error_str(kresult));
+
+      switch (kresult) {
+      case kIOReturnExclusiveAccess:
+	/* it is possible to perform some actions on a device that is not open so do not return an error */
+	priv->is_open = 0;
+
+	break;
+      default:
+	(*(dpriv->device))->Release (dpriv->device);
+	dpriv->device = NULL;
+	return darwin_to_libusb (kresult);
+      }
+    } else {
+      priv->is_open = 1;
+
+      /* create async event source */
+      kresult = (*(dpriv->device))->CreateDeviceAsyncEventSource (dpriv->device, &priv->cfSource);
+
+      CFRetain (libusb_darwin_acfl);
+
+      /* add the cfSource to the aync run loop */
+      CFRunLoopAddSource(libusb_darwin_acfl, priv->cfSource, kCFRunLoopCommonModes);
+    }
+  }
+
+  /* device opened successfully */
+  dpriv->open_count++;
+
+  /* create a file descriptor for notifications */
+  pipe (priv->fds);
+
+  /* set the pipe to be non-blocking */
+  fcntl (priv->fds[1], F_SETFD, O_NONBLOCK);
+
+  usbi_add_pollfd(HANDLE_CTX(dev_handle), priv->fds[0], POLLIN);
+
+  usbi_info (HANDLE_CTX (dev_handle), "device open for access");
+
+  return 0;
+}
+
+static void darwin_close (struct libusb_device_handle *dev_handle) {
+  struct darwin_device_handle_priv *priv = (struct darwin_device_handle_priv *)dev_handle->os_priv;
+  struct darwin_device_priv *dpriv = (struct darwin_device_priv *)dev_handle->dev->os_priv;
+  IOReturn kresult;
+  int i;
+
+  if (dpriv->open_count == 0) {
+    /* something is probably very wrong if this is the case */
+    usbi_err (HANDLE_CTX (dev_handle), "Close called on a device that was not open!\n");
+    return;
+  }
+
+  dpriv->open_count--;
+
+  /* make sure all interfaces are released */
+  for (i = 0 ; i < USB_MAXINTERFACES ; i++)
+    if (dev_handle->claimed_interfaces & (1 << i))
+      libusb_release_interface (dev_handle, i);
+
+  if (0 == dpriv->open_count) {
+    if (priv->is_open) {
+      /* delete the device's async event source */
+      if (priv->cfSource) {
+	CFRunLoopRemoveSource (libusb_darwin_acfl, priv->cfSource, kCFRunLoopDefaultMode);
+	CFRelease (priv->cfSource);
+      }
+
+      /* close the device */
+      kresult = (*(dpriv->device))->USBDeviceClose(dpriv->device);
+      if (kresult) {
+	/* Log the fact that we had a problem closing the file, however failing a
+	 * close isn't really an error, so return success anyway */
+	usbi_err (HANDLE_CTX (dev_handle), "USBDeviceClose: %s", darwin_error_str(kresult));
+      }
+    }
+
+    kresult = (*(dpriv->device))->Release(dpriv->device);
+    if (kresult) {
+      /* Log the fact that we had a problem closing the file, however failing a
+       * close isn't really an error, so return success anyway */
+      usbi_err (HANDLE_CTX (dev_handle), "Release: %s", darwin_error_str(kresult));
+    }
+
+    dpriv->device = NULL;
+  }
+
+  /* file descriptors are maintained per-instance */
+  usbi_remove_pollfd (HANDLE_CTX (dev_handle), priv->fds[0]);
+  close (priv->fds[1]);
+  close (priv->fds[0]);
+
+  priv->fds[0] = priv->fds[1] = -1;
+}
+
+static int darwin_get_configuration(struct libusb_device_handle *dev_handle, int *config) {
+  struct darwin_device_priv *dpriv = (struct darwin_device_priv *)dev_handle->dev->os_priv;
+
+  *config = (int) dpriv->active_config;
+
+  return 0;
+}
+
+static int darwin_set_configuration(struct libusb_device_handle *dev_handle, int config) {
+  struct darwin_device_priv *dpriv = (struct darwin_device_priv *)dev_handle->dev->os_priv;
+  IOReturn kresult;
+  int i;
+
+  /* Setting configuration will invalidate the interface, so we need
+     to reclaim it. First, dispose of existing interfaces, if any. */
+  for (i = 0 ; i < USB_MAXINTERFACES ; i++)
+    if (dev_handle->claimed_interfaces & (1 << i))
+      darwin_release_interface (dev_handle, i);
+
+  kresult = (*(dpriv->device))->SetConfiguration (dpriv->device, config);
+  if (kresult != kIOReturnSuccess)
+    return darwin_to_libusb (kresult);
+
+  /* Reclaim any interfaces. */
+  for (i = 0 ; i < USB_MAXINTERFACES ; i++)
+    if (dev_handle->claimed_interfaces & (1 << i))
+      darwin_claim_interface (dev_handle, i);
+
+  dpriv->active_config = config;
+
+  return 0;
+}
+
+static int darwin_get_interface (usb_device_t **darwin_device, uint8_t ifc, io_service_t *usbInterfacep) {
+  IOUSBFindInterfaceRequest request;
+  uint8_t                   current_interface;
+  kern_return_t             kresult;
+  io_iterator_t             interface_iterator;
+
+  *usbInterfacep = IO_OBJECT_NULL;
+
+  /* Setup the Interface Request */
+  request.bInterfaceClass    = kIOUSBFindInterfaceDontCare;
+  request.bInterfaceSubClass = kIOUSBFindInterfaceDontCare;
+  request.bInterfaceProtocol = kIOUSBFindInterfaceDontCare;
+  request.bAlternateSetting  = kIOUSBFindInterfaceDontCare;
+
+  kresult = (*(darwin_device))->CreateInterfaceIterator(darwin_device, &request, &interface_iterator);
+  if (kresult)
+    return kresult;
+
+  for ( current_interface = 0 ; current_interface <= ifc ; current_interface++ ) {
+    *usbInterfacep = IOIteratorNext(interface_iterator);
+    if (current_interface != ifc)
+      (void) IOObjectRelease (*usbInterfacep);
+  }
+
+  /* done with the interface iterator */
+  IOObjectRelease(interface_iterator);
+
+  return 0;
+}
+
+static int get_endpoints (struct libusb_device_handle *dev_handle, int iface) {
+  struct darwin_device_handle_priv *priv = (struct darwin_device_handle_priv *)dev_handle->os_priv;
+
+  /* current interface */
+  struct __darwin_interface *cInterface = &priv->interfaces[iface];
+
+  kern_return_t kresult;
+
+  u_int8_t numep, direction, number;
+  u_int8_t dont_care1, dont_care3;
+  u_int16_t dont_care2;
+  int i;
+
+  usbi_info (HANDLE_CTX (dev_handle), "building table of endpoints.");
+
+  /* retrieve the total number of endpoints on this interface */
+  kresult = (*(cInterface->interface))->GetNumEndpoints(cInterface->interface, &numep);
+  if (kresult) {
+    usbi_err (HANDLE_CTX (dev_handle), "can't get number of endpoints for interface: %s", darwin_error_str(kresult));
+    return darwin_to_libusb (kresult);
+  }
+
+  /* iterate through pipe references */
+  for (i = 1 ; i <= numep ; i++) {
+    kresult = (*(cInterface->interface))->GetPipeProperties(cInterface->interface, i, &direction, &number, &dont_care1,
+							    &dont_care2, &dont_care3);
+
+    if (kresult != kIOReturnSuccess) {
+      usbi_err (HANDLE_CTX (dev_handle), "error getting pipe information for pipe %d: %s", i, darwin_error_str(kresult));
+
+      return darwin_to_libusb (kresult);
+    }
+
+    usbi_info (HANDLE_CTX (dev_handle), "interface: %i pipe %i: dir: %i number: %i", iface, i, direction, number);
+
+    cInterface->endpoint_addrs[i - 1] = ((direction << 7 & LIBUSB_ENDPOINT_DIR_MASK) | (number & LIBUSB_ENDPOINT_ADDRESS_MASK));
+  }
+
+  cInterface->num_endpoints = numep;
+
+  return 0;
+}
+
+static int darwin_claim_interface(struct libusb_device_handle *dev_handle, int iface) {
+  struct darwin_device_priv *dpriv = (struct darwin_device_priv *)dev_handle->dev->os_priv;
+  struct darwin_device_handle_priv *priv = (struct darwin_device_handle_priv *)dev_handle->os_priv;
+  io_service_t          usbInterface = IO_OBJECT_NULL;
+  IOReturn kresult;
+  IOCFPlugInInterface **plugInInterface = NULL;
+  SInt32                score;
+
+  /* current interface */
+  struct __darwin_interface *cInterface = &priv->interfaces[iface];
+
+  kresult = darwin_get_interface (dpriv->device, iface, &usbInterface);
+  if (kresult != kIOReturnSuccess)
+    return darwin_to_libusb (kresult);
+
+  /* make sure we have an interface */
+  if (!usbInterface && dpriv->first_config != 0) {
+    usbi_info (HANDLE_CTX (dev_handle), "no interface found; setting configuration: %d", dpriv->first_config);
+
+    /* set the configuration */
+    kresult = darwin_set_configuration (dev_handle, dpriv->first_config);
+    if (kresult != LIBUSB_SUCCESS) {
+      usbi_err (HANDLE_CTX (dev_handle), "could not set configuration");
+      return kresult;
+    }
+
+    kresult = darwin_get_interface (dpriv->device, iface, &usbInterface);
+    if (kresult) {
+      usbi_err (HANDLE_CTX (dev_handle), "darwin_get_interface: %s", darwin_error_str(kresult));
+      return darwin_to_libusb (kresult);
+    }
+  }
+
+  if (!usbInterface) {
+    usbi_err (HANDLE_CTX (dev_handle), "interface not found");
+    return LIBUSB_ERROR_NOT_FOUND;
+  }
+
+  /* get an interface to the device's interface */
+  kresult = IOCreatePlugInInterfaceForService (usbInterface, kIOUSBInterfaceUserClientTypeID,
+					       kIOCFPlugInInterfaceID, &plugInInterface, &score);
+  if (kresult) {
+    usbi_err (HANDLE_CTX (dev_handle), "IOCreatePlugInInterfaceForService: %s", darwin_error_str(kresult));
+    return darwin_to_libusb (kresult);
+  }
+
+  if (!plugInInterface) {
+    usbi_err (HANDLE_CTX (dev_handle), "plugin interface not found");
+    return LIBUSB_ERROR_NOT_FOUND;
+  }
+
+  /* ignore release error */
+  (void)IOObjectRelease (usbInterface);
+
+  /* Do the actual claim */
+  kresult = (*plugInInterface)->QueryInterface(plugInInterface,
+					       CFUUIDGetUUIDBytes(kIOUSBInterfaceInterfaceID),
+					       (LPVOID)&cInterface->interface);
+  if (kresult || !cInterface->interface) {
+    usbi_err (HANDLE_CTX (dev_handle), "QueryInterface: %s", darwin_error_str(kresult));
+    return darwin_to_libusb (kresult);
+  }
+
+  /* We no longer need the intermediate plug-in */
+  (*plugInInterface)->Release(plugInInterface);
+
+  /* claim the interface */
+  kresult = (*(cInterface->interface))->USBInterfaceOpen(cInterface->interface);
+  if (kresult) {
+    usbi_err (HANDLE_CTX (dev_handle), "USBInterfaceOpen: %s", darwin_error_str(kresult));
+    return darwin_to_libusb (kresult);
+  }
+
+  /* update list of endpoints */
+  kresult = get_endpoints (dev_handle, iface);
+  if (kresult) {
+    /* this should not happen */
+    darwin_release_interface (dev_handle, iface);
+    usbi_err (HANDLE_CTX (dev_handle), "could not build endpoint table");
+    return kresult;
+  }
+
+  cInterface->cfSource = NULL;
+
+  /* create async event source */
+  kresult = (*(cInterface->interface))->CreateInterfaceAsyncEventSource (cInterface->interface, &cInterface->cfSource);
+  if (kresult != kIOReturnSuccess) {
+    usbi_err (HANDLE_CTX (dev_handle), "could not create async event source");
+
+    /* can't continue without an async event source */
+    (void)darwin_release_interface (dev_handle, iface);
+
+    return darwin_to_libusb (kresult);
+  }
+
+  /* add the cfSource to the async thread's run loop */
+  CFRunLoopAddSource(libusb_darwin_acfl, cInterface->cfSource, kCFRunLoopDefaultMode);
+
+  usbi_info (HANDLE_CTX (dev_handle), "interface opened");
+
+  return 0;
+}
+
+static int darwin_release_interface(struct libusb_device_handle *dev_handle, int iface) {
+  struct darwin_device_handle_priv *priv = (struct darwin_device_handle_priv *)dev_handle->os_priv;
+  IOReturn kresult;
+
+  /* current interface */
+  struct __darwin_interface *cInterface = &priv->interfaces[iface];
+
+  /* Check to see if an interface is open */
+  if (!cInterface->interface)
+    return LIBUSB_SUCCESS;
+
+  /* clean up endpoint data */
+  cInterface->num_endpoints = 0;
+
+  /* delete the interface's async event source */
+  if (cInterface->cfSource) {
+    CFRunLoopRemoveSource (libusb_darwin_acfl, cInterface->cfSource, kCFRunLoopDefaultMode);
+    CFRelease (cInterface->cfSource);
+  }
+
+  kresult = (*(cInterface->interface))->USBInterfaceClose(cInterface->interface);
+  if (kresult)
+    usbi_err (HANDLE_CTX (dev_handle), "USBInterfaceClose: %s", darwin_error_str(kresult));
+
+  kresult = (*(cInterface->interface))->Release(cInterface->interface);
+  if (kresult != kIOReturnSuccess)
+    usbi_err (HANDLE_CTX (dev_handle), "Release: %s", darwin_error_str(kresult));
+
+  cInterface->interface = IO_OBJECT_NULL;
+
+  return darwin_to_libusb (kresult);
+}
+
+static int darwin_set_interface_altsetting(struct libusb_device_handle *dev_handle, int iface, int altsetting) {
+  struct darwin_device_handle_priv *priv = (struct darwin_device_handle_priv *)dev_handle->os_priv;
+  IOReturn kresult;
+
+  /* current interface */
+  struct __darwin_interface *cInterface = &priv->interfaces[iface];
+
+  if (!cInterface->interface)
+    return LIBUSB_ERROR_NO_DEVICE;
+
+  kresult = (*(cInterface->interface))->SetAlternateInterface (cInterface->interface, altsetting);
+  if (kresult != kIOReturnSuccess)
+    darwin_reset_device (dev_handle);
+
+  /* update list of endpoints */
+  kresult = get_endpoints (dev_handle, iface);
+  if (kresult) {
+    /* this should not happen */
+    darwin_release_interface (dev_handle, iface);
+    usbi_err (HANDLE_CTX (dev_handle), "could not build endpoint table");
+    return kresult;
+  }
+
+  return darwin_to_libusb (kresult);
+}
+
+static int darwin_clear_halt(struct libusb_device_handle *dev_handle, unsigned char endpoint) {
+  struct darwin_device_handle_priv *priv = (struct darwin_device_handle_priv *)dev_handle->os_priv;
+
+  /* current interface */
+  struct __darwin_interface *cInterface;
+  uint8_t pipeRef, iface;
+  IOReturn kresult;
+
+  /* determine the interface/endpoint to use */
+  if (ep_to_pipeRef (dev_handle, endpoint, &pipeRef, &iface) != 0) {
+    usbi_err (HANDLE_CTX (dev_handle), "endpoint not found on any open interface");
+
+    return LIBUSB_ERROR_NOT_FOUND;
+  }
+
+  cInterface = &priv->interfaces[iface];
+
+#if (InterfaceVersion < 190)
+  kresult = (*(cInterface->interface))->ClearPipeStall(cInterface->interface, pipeRef);
+#else
+  /* newer versions of darwin support clearing additional bits on the device's endpoint */
+  kresult = (*(cInterface->interface))->ClearPipeStallBothEnds(cInterface->interface, pipeRef);
+#endif
+  if (kresult)
+    usbi_err (HANDLE_CTX (dev_handle), "ClearPipeStall: %s", darwin_error_str (kresult));
+
+  return darwin_to_libusb (kresult);
+}
+
+static int darwin_reset_device(struct libusb_device_handle *dev_handle) {
+  struct darwin_device_priv *dpriv = (struct darwin_device_priv *)dev_handle->dev->os_priv;
+  IOReturn kresult;
+
+  kresult = (*(dpriv->device))->ResetDevice (dpriv->device);
+  if (kresult)
+    usbi_err (HANDLE_CTX (dev_handle), "ResetDevice: %s", darwin_error_str (kresult));
+
+  return darwin_to_libusb (kresult);
+}
+
+static int darwin_kernel_driver_active(struct libusb_device_handle *dev_handle, int interface) {
+  struct darwin_device_priv *dpriv = (struct darwin_device_priv *)dev_handle->dev->os_priv;
+  io_service_t usbInterface;
+  CFTypeRef driver;
+  IOReturn kresult;
+
+  kresult = darwin_get_interface (dpriv->device, interface, &usbInterface);
+  if (kresult) {
+    usbi_err (HANDLE_CTX (dev_handle), "darwin_get_interface: %s", darwin_error_str(kresult));
+
+    return darwin_to_libusb (kresult);
+  }
+
+  driver = IORegistryEntryCreateCFProperty (usbInterface, kIOBundleIdentifierKey, kCFAllocatorDefault, 0);
+  IOObjectRelease (usbInterface);
+
+  if (driver) {
+    CFRelease (driver);
+
+    return 1;
+  }
+
+  /* no driver */
+  return 0;
+}
+
+/* attaching/detaching kernel drivers is not currently supported (maybe in the future?) */
+static int darwin_attach_kernel_driver (struct libusb_device_handle *dev_handle, int interface) {
+  return LIBUSB_ERROR_NOT_SUPPORTED;
+}
+
+static int darwin_detach_kernel_driver (struct libusb_device_handle *dev_handle, int interface) {
+  return LIBUSB_ERROR_NOT_SUPPORTED;
+}
+
+static void darwin_destroy_device(struct libusb_device *dev) {
+}
+
+static int submit_bulk_transfer(struct usbi_transfer *itransfer) {
+  struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+  struct darwin_device_handle_priv *priv = (struct darwin_device_handle_priv *)transfer->dev_handle->os_priv;
+
+  IOReturn               ret;
+  uint8_t                is_read; /* 0 = we're reading, 1 = we're writing */
+  uint8_t                transferType;
+  /* None of the values below are used in libusb for bulk transfers */
+  uint8_t                direction, number, interval, pipeRef, iface;
+  uint16_t               maxPacketSize;
+
+  struct __darwin_interface *cInterface;
+
+  /* are we reading or writing? */
+  is_read = transfer->endpoint & LIBUSB_ENDPOINT_IN;
+
+  if (ep_to_pipeRef (transfer->dev_handle, transfer->endpoint, &pipeRef, &iface) != 0) {
+    usbi_err (TRANSFER_CTX (transfer), "endpoint not found on any open interface");
+
+    return LIBUSB_ERROR_NOT_FOUND;
+  }
+
+  cInterface = &priv->interfaces[iface];
+
+  (*(cInterface->interface))->GetPipeProperties (cInterface->interface, pipeRef, &direction, &number,
+						 &transferType, &maxPacketSize, &interval);
+
+  /* submit the request */
+  /* timeouts are unavailable on interrupt endpoints */
+  if (transferType == kUSBInterrupt) {
+    if (is_read)
+      ret = (*(cInterface->interface))->ReadPipeAsync(cInterface->interface, pipeRef, transfer->buffer,
+						      transfer->length, darwin_async_io_callback, itransfer);
+    else
+      ret = (*(cInterface->interface))->WritePipeAsync(cInterface->interface, pipeRef, transfer->buffer,
+						       transfer->length, darwin_async_io_callback, itransfer);
+  } else {
+    if (is_read)
+      ret = (*(cInterface->interface))->ReadPipeAsyncTO(cInterface->interface, pipeRef, transfer->buffer,
+							transfer->length, transfer->timeout, transfer->timeout,
+							darwin_async_io_callback, (void *)itransfer);
+    else
+      ret = (*(cInterface->interface))->WritePipeAsyncTO(cInterface->interface, pipeRef, transfer->buffer,
+							 transfer->length, transfer->timeout, transfer->timeout,
+							 darwin_async_io_callback, (void *)itransfer);
+  }
+
+  if (ret)
+    usbi_err (TRANSFER_CTX (transfer), "bulk transfer failed (dir = %s): %s (code = 0x%08x)", is_read ? "In" : "Out",
+	       darwin_error_str(ret), ret);
+
+  return darwin_to_libusb (ret);
+}
+
+static int submit_iso_transfer(struct usbi_transfer *itransfer) {
+  struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+  struct darwin_transfer_priv *tpriv = usbi_transfer_get_os_priv(itransfer);
+  struct darwin_device_handle_priv *priv = (struct darwin_device_handle_priv *)transfer->dev_handle->os_priv;
+
+  IOReturn                kresult;
+  uint8_t                 is_read; /* 0 = we're writing, 1 = we're reading */
+  uint8_t                 pipeRef, iface;
+  UInt64                  frame;
+  AbsoluteTime            atTime;
+  int                     i;
+
+  struct __darwin_interface *cInterface;
+
+  /* are we reading or writing? */
+  is_read = transfer->endpoint & LIBUSB_ENDPOINT_IN;
+
+  /* construct an array of IOUSBIsocFrames */
+  tpriv->isoc_framelist = (IOUSBIsocFrame*) calloc (transfer->num_iso_packets, sizeof(IOUSBIsocFrame));
+  if (!tpriv->isoc_framelist)
+    return LIBUSB_ERROR_NO_MEM;
+
+  /* copy the frame list from the libusb descriptor (the structures differ only is member order) */
+  for (i = 0 ; i < transfer->num_iso_packets ; i++)
+    tpriv->isoc_framelist[i].frReqCount = transfer->iso_packet_desc[i].length;
+
+  /* determine the interface/endpoint to use */
+  if (ep_to_pipeRef (transfer->dev_handle, transfer->endpoint, &pipeRef, &iface) != 0) {
+    usbi_err (TRANSFER_CTX (transfer), "endpoint not found on any open interface");
+
+    return LIBUSB_ERROR_NOT_FOUND;
+  }
+
+  cInterface = &priv->interfaces[iface];
+
+  /* Last but not least we need the bus frame number */
+  kresult = (*(cInterface->interface))->GetBusFrameNumber(cInterface->interface, &frame, &atTime);
+  if (kresult) {
+    usbi_err (TRANSFER_CTX (transfer), "failed to get bus frame number: %d", kresult);
+    free(tpriv->isoc_framelist);
+    tpriv->isoc_framelist = NULL;
+
+    return darwin_to_libusb (kresult);
+  }
+
+  /* schedule for a frame a little in the future */
+  frame += 2;
+
+  /* submit the request */
+  if (is_read)
+    kresult = (*(cInterface->interface))->ReadIsochPipeAsync(cInterface->interface, pipeRef, transfer->buffer, frame,
+							     transfer->num_iso_packets, tpriv->isoc_framelist, darwin_async_io_callback,
+							     itransfer);
+  else
+    kresult = (*(cInterface->interface))->WriteIsochPipeAsync(cInterface->interface, pipeRef, transfer->buffer, frame,
+							      transfer->num_iso_packets, tpriv->isoc_framelist, darwin_async_io_callback,
+							      itransfer);
+
+  if (kresult != kIOReturnSuccess) {
+    usbi_err (TRANSFER_CTX (transfer), "isochronous transfer failed (dir: %s): %s", is_read ? "In" : "Out",
+	       darwin_error_str(kresult));
+    free (tpriv->isoc_framelist);
+    tpriv->isoc_framelist = NULL;
+  }
+
+  return darwin_to_libusb (kresult);
+}
+
+static int submit_control_transfer(struct usbi_transfer *itransfer) {
+  struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+  struct libusb_control_setup *setup = (struct libusb_control_setup *) transfer->buffer;
+  struct darwin_device_priv *dpriv = (struct darwin_device_priv *)transfer->dev_handle->dev->os_priv;
+  struct darwin_transfer_priv *tpriv = usbi_transfer_get_os_priv(itransfer);
+
+  IOReturn               kresult;
+
+  bzero(&tpriv->req, sizeof(tpriv->req));
+
+  /* IOUSBDeviceInterface expects the request in cpu endianess */
+  tpriv->req.bmRequestType     = setup->bmRequestType;
+  tpriv->req.bRequest          = setup->bRequest;
+  /* these values should be in bus order from libusb_fill_control_setup */
+  tpriv->req.wValue            = OSSwapLittleToHostInt16 (setup->wValue);
+  tpriv->req.wIndex            = OSSwapLittleToHostInt16 (setup->wIndex);
+  tpriv->req.wLength           = OSSwapLittleToHostInt16 (setup->wLength);
+  /* data is stored after the libusb control block */
+  tpriv->req.pData             = transfer->buffer + LIBUSB_CONTROL_SETUP_SIZE;
+  tpriv->req.completionTimeout = transfer->timeout;
+  tpriv->req.noDataTimeout     = transfer->timeout;
+
+  /* all transfers in libusb-1.0 are async */
+  kresult = (*(dpriv->device))->DeviceRequestAsyncTO(dpriv->device, &(tpriv->req), darwin_async_io_callback, itransfer);
+
+  if (kresult != kIOReturnSuccess)
+    usbi_err (TRANSFER_CTX (transfer), "control request failed: %s", darwin_error_str(kresult));
+
+  return darwin_to_libusb (kresult);
+}
+
+static int darwin_submit_transfer(struct usbi_transfer *itransfer) {
+  struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+
+  switch (transfer->type) {
+  case LIBUSB_TRANSFER_TYPE_CONTROL:
+    return submit_control_transfer(itransfer);
+  case LIBUSB_TRANSFER_TYPE_BULK:
+  case LIBUSB_TRANSFER_TYPE_INTERRUPT:
+    return submit_bulk_transfer(itransfer);
+  case LIBUSB_TRANSFER_TYPE_ISOCHRONOUS:
+    return submit_iso_transfer(itransfer);
+  default:
+    usbi_err (TRANSFER_CTX(transfer), "unknown endpoint type %d", transfer->type);
+    return LIBUSB_ERROR_INVALID_PARAM;
+  }
+}
+
+static int cancel_control_transfer(struct usbi_transfer *itransfer) {
+  struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+  struct darwin_device_priv *dpriv = (struct darwin_device_priv *)transfer->dev_handle->dev->os_priv;
+  IOReturn kresult;
+
+  usbi_info (ITRANSFER_CTX (itransfer), "WARNING: aborting all transactions control pipe");
+
+  kresult = (*(dpriv->device))->USBDeviceAbortPipeZero (dpriv->device);
+
+  return darwin_to_libusb (kresult);
+}
+
+static int darwin_abort_transfers (struct usbi_transfer *itransfer) {
+  struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+  struct darwin_device_handle_priv *priv = (struct darwin_device_handle_priv *)transfer->dev_handle->os_priv;
+  struct __darwin_interface *cInterface;
+  uint8_t pipeRef, iface;
+  IOReturn kresult;
+
+  if (ep_to_pipeRef (transfer->dev_handle, transfer->endpoint, &pipeRef, &iface) != 0) {
+    usbi_err (TRANSFER_CTX (transfer), "endpoint not found on any open interface");
+
+    return LIBUSB_ERROR_NOT_FOUND;
+  }
+
+  cInterface = &priv->interfaces[iface];
+
+  usbi_info (ITRANSFER_CTX (itransfer), "WARNING: aborting all transactions on interface %d pipe %d", iface, pipeRef);
+
+  /* abort transactions */
+  (*(cInterface->interface))->AbortPipe (cInterface->interface, pipeRef);
+
+  usbi_info (ITRANSFER_CTX (itransfer), "calling clear pipe stall to clear the data toggle bit");
+
+  /* clear the data toggle bit */
+#if (InterfaceVersion < 190)
+  kresult = (*(cInterface->interface))->ClearPipeStall(cInterface->interface, pipeRef);
+#else
+  /* newer versions of darwin support clearing additional bits on the device's endpoint */
+  kresult = (*(cInterface->interface))->ClearPipeStallBothEnds(cInterface->interface, pipeRef);
+#endif
+
+  return darwin_to_libusb (kresult);
+}
+
+static int darwin_cancel_transfer(struct usbi_transfer *itransfer) {
+  struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+
+  switch (transfer->type) {
+  case LIBUSB_TRANSFER_TYPE_CONTROL:
+    return cancel_control_transfer(itransfer);
+  case LIBUSB_TRANSFER_TYPE_BULK:
+  case LIBUSB_TRANSFER_TYPE_INTERRUPT:
+  case LIBUSB_TRANSFER_TYPE_ISOCHRONOUS:
+    return darwin_abort_transfers (itransfer);
+  default:
+    usbi_err (TRANSFER_CTX(transfer), "unknown endpoint type %d", transfer->type);
+    return LIBUSB_ERROR_INVALID_PARAM;
+  }
+}
+
+static void darwin_clear_transfer_priv (struct usbi_transfer *itransfer) {
+  struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+  struct darwin_transfer_priv *tpriv = usbi_transfer_get_os_priv(itransfer);
+
+  if (transfer->type == LIBUSB_TRANSFER_TYPE_ISOCHRONOUS && tpriv->isoc_framelist) {
+    free (tpriv->isoc_framelist);
+    tpriv->isoc_framelist = NULL;
+  }
+}
+
+static void darwin_async_io_callback (void *refcon, IOReturn result, void *arg0) {
+  struct usbi_transfer *itransfer = (struct usbi_transfer *)refcon;
+  struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+  struct darwin_device_handle_priv *priv = (struct darwin_device_handle_priv *)transfer->dev_handle->os_priv;
+  UInt32 message;
+
+  usbi_info (ITRANSFER_CTX (itransfer), "an async io operation has completed");
+
+  /* send a completion message to the device's file descriptor */
+  message = MESSAGE_ASYNC_IO_COMPLETE;
+  write (priv->fds[1], &message, sizeof (message));
+  write (priv->fds[1], &itransfer, sizeof (itransfer));
+  write (priv->fds[1], &result, sizeof (IOReturn));
+  write (priv->fds[1], &arg0, sizeof (UInt32));
+}
+
+static int darwin_transfer_status (struct usbi_transfer *itransfer, kern_return_t result) {
+  switch (result) {
+  case kIOReturnUnderrun:
+  case kIOReturnSuccess:
+    return LIBUSB_TRANSFER_COMPLETED;
+  case kIOReturnAborted:
+    return LIBUSB_TRANSFER_CANCELLED;
+  case kIOUSBPipeStalled:
+    usbi_warn (ITRANSFER_CTX (itransfer), "transfer error: pipe is stalled");
+    return LIBUSB_TRANSFER_STALL;
+  case kIOReturnOverrun:
+    usbi_err (ITRANSFER_CTX (itransfer), "transfer error: data overrun");
+    return LIBUSB_TRANSFER_OVERFLOW;
+  case kIOUSBTransactionTimeout:
+    usbi_err (ITRANSFER_CTX (itransfer), "transfer error: timed out");
+    return LIBUSB_TRANSFER_TIMED_OUT;
+  default:
+    usbi_err (ITRANSFER_CTX (itransfer), "transfer error: %s (value = 0x%08x)", darwin_error_str (result), result);
+    return LIBUSB_TRANSFER_ERROR;
+  }
+}
+
+static void darwin_handle_callback (struct usbi_transfer *itransfer, kern_return_t result, UInt32 io_size) {
+  struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+  struct darwin_transfer_priv *tpriv = usbi_transfer_get_os_priv(itransfer);
+  int isIsoc      = LIBUSB_TRANSFER_TYPE_ISOCHRONOUS == transfer->type;
+  int isBulk      = LIBUSB_TRANSFER_TYPE_BULK == transfer->type;
+  int isControl   = LIBUSB_TRANSFER_TYPE_CONTROL == transfer->type;
+  int isInterrupt = LIBUSB_TRANSFER_TYPE_INTERRUPT == transfer->type;
+  int i;
+
+  if (!isIsoc && !isBulk && !isControl && !isInterrupt) {
+    usbi_err (TRANSFER_CTX(transfer), "unknown endpoint type %d", transfer->type);
+    return;
+  }
+
+  usbi_info (ITRANSFER_CTX (itransfer), "handling %s completion with kernel status %d",
+	     isControl ? "control" : isBulk ? "bulk" : isIsoc ? "isoc" : "interrupt", result);
+
+  if (kIOReturnSuccess == result || kIOReturnUnderrun == result) {
+    if (isIsoc && tpriv->isoc_framelist) {
+      /* copy isochronous results back */
+
+      for (i = 0; i < transfer->num_iso_packets ; i++) {
+	struct libusb_iso_packet_descriptor *lib_desc = &transfer->iso_packet_desc[i];
+	lib_desc->status = darwin_to_libusb (tpriv->isoc_framelist[i].frStatus);
+	lib_desc->actual_length = tpriv->isoc_framelist[i].frActCount;
+      }
+    } else if (!isIsoc)
+      itransfer->transferred += io_size;
+  }
+
+  /* it is ok to handle cancelled transfers without calling usbi_handle_transfer_cancellation (we catch timeout transfers) */
+  usbi_handle_transfer_completion (itransfer, darwin_transfer_status (itransfer, result));
+}
+
+static int op_handle_events(struct libusb_context *ctx, struct pollfd *fds, nfds_t nfds, int num_ready) {
+  struct usbi_transfer *itransfer;
+  UInt32 io_size;
+  IOReturn kresult;
+  int i = 0, ret;
+  UInt32 message;
+
+  usbi_mutex_lock(&ctx->open_devs_lock);
+  for (i = 0; i < nfds && num_ready > 0; i++) {
+    struct pollfd *pollfd = &fds[i];
+    struct libusb_device_handle *handle;
+    struct darwin_device_handle_priv *hpriv = NULL;
+
+    usbi_info (ctx, "checking fd %i with revents = %x", fds[i], pollfd->revents);
+
+    if (!pollfd->revents)
+      continue;
+
+    num_ready--;
+    list_for_each_entry(handle, &ctx->open_devs, list, struct libusb_device_handle) {
+      hpriv =  (struct darwin_device_handle_priv *)handle->os_priv;
+      if (hpriv->fds[0] == pollfd->fd)
+	break;
+    }
+
+    if (!(pollfd->revents & POLLERR)) {
+      ret = read (hpriv->fds[0], &message, sizeof (message));
+      if (ret < sizeof (message))
+	continue;
+    } else
+      /* could not poll the device-- response is to delete the device (this seems a little heavy-handed) */
+      message = MESSAGE_DEVICE_GONE;
+
+    switch (message) {
+    case MESSAGE_DEVICE_GONE:
+      /* remove the device's async port from the runloop */
+      if (hpriv->cfSource) {
+	if (libusb_darwin_acfl)
+	  CFRunLoopRemoveSource (libusb_darwin_acfl, hpriv->cfSource, kCFRunLoopDefaultMode);
+	CFRelease (hpriv->cfSource);
+	hpriv->cfSource = NULL;
+      }
+
+      usbi_remove_pollfd(HANDLE_CTX(handle), hpriv->fds[0]);
+      usbi_handle_disconnect(handle);
+
+      /* done with this device */
+      continue;
+    case MESSAGE_ASYNC_IO_COMPLETE:
+      read (hpriv->fds[0], &itransfer, sizeof (itransfer));
+      read (hpriv->fds[0], &kresult, sizeof (IOReturn));
+      read (hpriv->fds[0], &io_size, sizeof (UInt32));
+
+      darwin_handle_callback (itransfer, kresult, io_size);
+      break;
+    default:
+      usbi_err (ctx, "unknown message received from device pipe");
+    }
+  }
+
+  usbi_mutex_unlock(&ctx->open_devs_lock);
+
+  return 0;
+}
+
+static int darwin_clock_gettime(int clk_id, struct timespec *tp) {
+  mach_timespec_t sys_time;
+  clock_serv_t clock_ref;
+
+  switch (clk_id) {
+  case USBI_CLOCK_REALTIME:
+    /* CLOCK_REALTIME represents time since the epoch */
+    host_get_clock_service(mach_host_self(), CALENDAR_CLOCK, &clock_ref);
+    break;
+  case USBI_CLOCK_MONOTONIC:
+    /* use system boot time as reference for the monotonic clock */
+    host_get_clock_service(mach_host_self(), SYSTEM_CLOCK, &clock_ref);
+    break;
+  default:
+    return LIBUSB_ERROR_INVALID_PARAM;
+  }
+
+  clock_get_time (clock_ref, &sys_time);
+
+  tp->tv_sec  = sys_time.tv_sec;
+  tp->tv_nsec = sys_time.tv_nsec;
+
+  return 0;
+}
+
+const struct usbi_os_backend darwin_backend = {
+	.name = "Darwin",
+	.init = darwin_init,
+	.exit = darwin_exit,
+	.get_device_list = darwin_get_device_list,
+	.get_device_descriptor = darwin_get_device_descriptor,
+	.get_active_config_descriptor = darwin_get_active_config_descriptor,
+	.get_config_descriptor = darwin_get_config_descriptor,
+
+	.open = darwin_open,
+	.close = darwin_close,
+	.get_configuration = darwin_get_configuration,
+	.set_configuration = darwin_set_configuration,
+	.claim_interface = darwin_claim_interface,
+	.release_interface = darwin_release_interface,
+
+	.set_interface_altsetting = darwin_set_interface_altsetting,
+	.clear_halt = darwin_clear_halt,
+	.reset_device = darwin_reset_device,
+
+	.kernel_driver_active = darwin_kernel_driver_active,
+	.detach_kernel_driver = darwin_detach_kernel_driver,
+	.attach_kernel_driver = darwin_attach_kernel_driver,
+
+	.destroy_device = darwin_destroy_device,
+
+	.submit_transfer = darwin_submit_transfer,
+	.cancel_transfer = darwin_cancel_transfer,
+	.clear_transfer_priv = darwin_clear_transfer_priv,
+
+	.handle_events = op_handle_events,
+
+	.clock_gettime = darwin_clock_gettime,
+
+	.device_priv_size = sizeof(struct darwin_device_priv),
+	.device_handle_priv_size = sizeof(struct darwin_device_handle_priv),
+	.transfer_priv_size = sizeof(struct darwin_transfer_priv),
+	.add_iso_packet_size = 0,
+};
+
diff --git a/include/libusb-1.0/os/darwin_usb.h b/include/libusb-1.0/os/darwin_usb.h
new file mode 100644
index 0000000..a71d464
--- /dev/null
+++ b/include/libusb-1.0/os/darwin_usb.h
@@ -0,0 +1,167 @@
+/*
+ * darwin backend for libusb 1.0
+ * Copyright (C) 2008-2009 Nathan Hjelm <hjelmn@users.sourceforge.net>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#if !defined(LIBUSB_DARWIN_H)
+#define LIBUSB_DARWIN_H
+
+#include "libusbi.h"
+
+#include <IOKit/IOTypes.h>
+#include <IOKit/IOCFBundle.h>
+#include <IOKit/usb/IOUSBLib.h>
+#include <IOKit/IOCFPlugIn.h>
+
+/* IOUSBInterfaceInferface */
+#if defined (kIOUSBInterfaceInterfaceID300)
+
+#define usb_interface_t IOUSBInterfaceInterface300
+#define InterfaceInterfaceID kIOUSBInterfaceInterfaceID300
+#define InterfaceVersion 300
+
+#elif defined (kIOUSBInterfaceInterfaceID245)
+
+#define usb_interface_t IOUSBInterfaceInterface245
+#define InterfaceInterfaceID kIOUSBInterfaceInterfaceID245
+#define InterfaceVersion 245
+
+#elif defined (kIOUSBInterfaceInterfaceID220)
+
+#define usb_interface_t IOUSBInterfaceInterface220
+#define InterfaceInterfaceID kIOUSBInterfaceInterfaceID220
+#define InterfaceVersion 220
+
+#elif defined (kIOUSBInterfaceInterfaceID197)
+
+#define usb_interface_t IOUSBInterfaceInterface197
+#define InterfaceInterfaceID kIOUSBInterfaceInterfaceID197
+#define InterfaceVersion 197
+
+#elif defined (kIOUSBInterfaceInterfaceID190)
+
+#define usb_interface_t IOUSBInterfaceInterface190
+#define InterfaceInterfaceID kIOUSBInterfaceInterfaceID190
+#define InterfaceVersion 190
+
+#elif defined (kIOUSBInterfaceInterfaceID182)
+
+#define usb_interface_t IOUSBInterfaceInterface182
+#define InterfaceInterfaceID kIOUSBInterfaceInterfaceID182
+#define InterfaceVersion 182
+
+#else
+
+#error "IOUSBFamily is too old. Please upgrade your OS"
+
+#endif
+
+/* IOUSBDeviceInterface */
+#if defined (kIOUSBDeviceInterfaceID320)
+
+#define usb_device_t    IOUSBDeviceInterface320
+#define DeviceInterfaceID kIOUSBDeviceInterfaceID320
+#define DeviceVersion 320
+
+#elif defined (kIOUSBDeviceInterfaceID300)
+
+#define usb_device_t    IOUSBDeviceInterface300
+#define DeviceInterfaceID kIOUSBDeviceInterfaceID300
+#define DeviceVersion 300
+
+#elif defined (kIOUSBDeviceInterfaceID245)
+
+#define usb_device_t    IOUSBDeviceInterface245
+#define DeviceInterfaceID kIOUSBDeviceInterfaceID245
+#define DeviceVersion 245
+
+#elif defined (kIOUSBDeviceInterfaceID197)
+
+#define usb_device_t    IOUSBDeviceInterface197
+#define DeviceInterfaceID kIOUSBDeviceInterfaceID197
+#define DeviceVersion 197
+
+#elif defined (kIOUSBDeviceInterfaceID187)
+
+#define usb_device_t    IOUSBDeviceInterface187
+#define DeviceInterfaceID kIOUSBDeviceInterfaceID187
+#define DeviceVersion 187
+
+#elif defined (kIOUSBDeviceInterfaceID182)
+
+#define usb_device_t    IOUSBDeviceInterface182
+#define DeviceInterfaceID kIOUSBDeviceInterfaceID182
+#define DeviceVersion 182
+
+#else
+
+#error "IOUSBFamily is too old. Please upgrade your OS"
+
+#endif
+
+#if !defined(IO_OBJECT_NULL)
+#define IO_OBJECT_NULL ((io_object_t) 0)
+#endif
+
+typedef IOCFPlugInInterface *io_cf_plugin_ref_t;
+typedef IONotificationPortRef io_notification_port_t;
+
+/* private structures */
+struct darwin_device_priv {
+  IOUSBDeviceDescriptor dev_descriptor;
+  UInt32                location;
+  char                  sys_path[21];
+  usb_device_t        **device;
+  int                   open_count;
+  UInt8                 first_config, active_config;
+};
+
+struct darwin_device_handle_priv {
+  int                  is_open;
+  CFRunLoopSourceRef   cfSource;
+  int                  fds[2];
+
+  struct __darwin_interface {
+    usb_interface_t    **interface;
+    uint8_t              num_endpoints;
+    CFRunLoopSourceRef   cfSource;
+    uint8_t            endpoint_addrs[USB_MAXENDPOINTS];
+  } interfaces[USB_MAXINTERFACES];
+};
+
+struct darwin_transfer_priv {
+  /* Isoc */
+  IOUSBIsocFrame *isoc_framelist;
+
+  /* Control */
+#if !defined (LIBUSB_NO_TIMEOUT_DEVICE)
+  IOUSBDevRequestTO req;
+#else
+  IOUSBDevRequest req;
+#endif
+
+  /* Bulk */
+};
+
+enum {
+  MESSAGE_DEVICE_GONE,
+  MESSAGE_ASYNC_IO_COMPLETE
+};
+
+
+
+#endif
diff --git a/include/libusb-1.0/os/libusb.h b/include/libusb-1.0/os/libusb.h
new file mode 100644
index 0000000..8dc3362
--- /dev/null
+++ b/include/libusb-1.0/os/libusb.h
@@ -0,0 +1,1322 @@
+/*
+ * Public libusb header file
+ * Copyright (C) 2007-2008 Daniel Drake <dsd@gentoo.org>
+ * Copyright (c) 2001 Johannes Erdfelt <johannes@erdfelt.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef __LIBUSB_H__
+#define __LIBUSB_H__
+
+/* MSVC doesn't like inline, but does accept __inline ?? */
+#ifdef _MSC_VER
+#define inline __inline
+#endif
+
+#include <stdint.h>
+#include <sys/types.h>
+#include <time.h>
+#include <limits.h>
+
+#if defined(__linux) || defined(__APPLE__) || defined(__CYGWIN__)
+#include <sys/time.h>
+#endif
+
+/* 'interface' might be defined as a macro on Windows, so we need to
+ * undefine it so as not to break the current libusb API, because
+ * libusb_config_descriptor has an 'interface' member
+ * As this can be problematic if you include windows.h after libusb.h
+ * in your sources, we force windows.h to be included first. */
+#if defined(_WIN32) || defined(__CYGWIN__)
+#include <windows.h>
+#if defined(interface)
+#undef interface
+#endif
+#endif
+
+/** \def LIBUSB_CALL
+ * \ingroup misc
+ * libusb's Windows calling convention.
+ *
+ * Under Windows, the selection of available compilers and configurations
+ * means that, unlike other platforms, there is not <em>one true calling
+ * convention</em> (calling convention: the manner in which parameters are
+ * passed to funcions in the generated assembly code).
+ *
+ * Matching the Windows API itself, libusb uses the WINAPI convention (which
+ * translates to the <tt>stdcall</tt> convention) and guarantees that the
+ * library is compiled in this way. The public header file also includes
+ * appropriate annotations so that your own software will use the right
+ * convention, even if another convention is being used by default within
+ * your codebase.
+ *
+ * The one consideration that you must apply in your software is to mark
+ * all functions which you use as libusb callbacks with this LIBUSB_CALL
+ * annotation, so that they too get compiled for the correct calling
+ * convention.
+ *
+ * On non-Windows operating systems, this macro is defined as nothing. This
+ * means that you can apply it to your code without worrying about
+ * cross-platform compatibility.
+ */
+/* LIBUSB_CALL must be defined on both definition and declaration of libusb
+ * functions. You'd think that declaration would be enough, but cygwin will
+ * complain about conflicting types unless both are marked this way.
+ * The placement of this macro is important too; it must appear after the
+ * return type, before the function name. See internal documentation for
+ * API_EXPORTED.
+ */
+#if defined(_WIN32) || defined(__CYGWIN__)
+#define LIBUSB_CALL WINAPI
+#else
+#define LIBUSB_CALL
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** \def libusb_cpu_to_le16
+ * \ingroup misc
+ * Convert a 16-bit value from host-endian to little-endian format. On
+ * little endian systems, this function does nothing. On big endian systems,
+ * the bytes are swapped.
+ * \param x the host-endian value to convert
+ * \returns the value in little-endian byte order
+ */
+static inline uint16_t libusb_cpu_to_le16(const uint16_t x)
+{
+	union {
+		uint8_t  b8[2];
+		uint16_t b16;
+	} _tmp;
+	_tmp.b8[1] = x >> 8;
+	_tmp.b8[0] = x & 0xff;
+	return _tmp.b16;
+}
+
+/** \def libusb_le16_to_cpu
+ * \ingroup misc
+ * Convert a 16-bit value from little-endian to host-endian format. On
+ * little endian systems, this function does nothing. On big endian systems,
+ * the bytes are swapped.
+ * \param x the little-endian value to convert
+ * \returns the value in host-endian byte order
+ */
+#define libusb_le16_to_cpu libusb_cpu_to_le16
+
+/* standard USB stuff */
+
+/** \ingroup desc
+ * Device and/or Interface Class codes */
+enum libusb_class_code {
+	/** In the context of a \ref libusb_device_descriptor "device descriptor",
+	 * this bDeviceClass value indicates that each interface specifies its
+	 * own class information and all interfaces operate independently.
+	 */
+	LIBUSB_CLASS_PER_INTERFACE = 0,
+
+	/** Audio class */
+	LIBUSB_CLASS_AUDIO = 1,
+
+	/** Communications class */
+	LIBUSB_CLASS_COMM = 2,
+
+	/** Human Interface Device class */
+	LIBUSB_CLASS_HID = 3,
+
+	/** Printer dclass */
+	LIBUSB_CLASS_PRINTER = 7,
+
+	/** Picture transfer protocol class */
+	LIBUSB_CLASS_PTP = 6,
+
+	/** Mass storage class */
+	LIBUSB_CLASS_MASS_STORAGE = 8,
+
+	/** Hub class */
+	LIBUSB_CLASS_HUB = 9,
+
+	/** Data class */
+	LIBUSB_CLASS_DATA = 10,
+
+	/** Wireless class */
+	LIBUSB_CLASS_WIRELESS = 0xe0,
+
+	/** Application class */
+	LIBUSB_CLASS_APPLICATION = 0xfe,
+
+	/** Class is vendor-specific */
+	LIBUSB_CLASS_VENDOR_SPEC = 0xff
+};
+
+/** \ingroup desc
+ * Descriptor types as defined by the USB specification. */
+enum libusb_descriptor_type {
+	/** Device descriptor. See libusb_device_descriptor. */
+	LIBUSB_DT_DEVICE = 0x01,
+
+	/** Configuration descriptor. See libusb_config_descriptor. */
+	LIBUSB_DT_CONFIG = 0x02,
+
+	/** String descriptor */
+	LIBUSB_DT_STRING = 0x03,
+
+	/** Interface descriptor. See libusb_interface_descriptor. */
+	LIBUSB_DT_INTERFACE = 0x04,
+
+	/** Endpoint descriptor. See libusb_endpoint_descriptor. */
+	LIBUSB_DT_ENDPOINT = 0x05,
+
+	/** HID descriptor */
+	LIBUSB_DT_HID = 0x21,
+
+	/** HID report descriptor */
+	LIBUSB_DT_REPORT = 0x22,
+
+	/** Physical descriptor */
+	LIBUSB_DT_PHYSICAL = 0x23,
+
+	/** Hub descriptor */
+	LIBUSB_DT_HUB = 0x29
+};
+
+/* Descriptor sizes per descriptor type */
+#define LIBUSB_DT_DEVICE_SIZE			18
+#define LIBUSB_DT_CONFIG_SIZE			9
+#define LIBUSB_DT_INTERFACE_SIZE		9
+#define LIBUSB_DT_ENDPOINT_SIZE		7
+#define LIBUSB_DT_ENDPOINT_AUDIO_SIZE	9	/* Audio extension */
+#define LIBUSB_DT_HUB_NONVAR_SIZE		7
+
+#define LIBUSB_ENDPOINT_ADDRESS_MASK	0x0f    /* in bEndpointAddress */
+#define LIBUSB_ENDPOINT_DIR_MASK		0x80
+
+/** \ingroup desc
+ * Endpoint direction. Values for bit 7 of the
+ * \ref libusb_endpoint_descriptor::bEndpointAddress "endpoint address" scheme.
+ */
+enum libusb_endpoint_direction {
+	/** In: device-to-host */
+	LIBUSB_ENDPOINT_IN = 0x80,
+
+	/** Out: host-to-device */
+	LIBUSB_ENDPOINT_OUT = 0x00
+};
+
+#define LIBUSB_TRANSFER_TYPE_MASK			0x03    /* in bmAttributes */
+
+/** \ingroup desc
+ * Endpoint transfer type. Values for bits 0:1 of the
+ * \ref libusb_endpoint_descriptor::bmAttributes "endpoint attributes" field.
+ */
+enum libusb_transfer_type {
+	/** Control endpoint */
+	LIBUSB_TRANSFER_TYPE_CONTROL = 0,
+
+	/** Isochronous endpoint */
+	LIBUSB_TRANSFER_TYPE_ISOCHRONOUS = 1,
+
+	/** Bulk endpoint */
+	LIBUSB_TRANSFER_TYPE_BULK = 2,
+
+	/** Interrupt endpoint */
+	LIBUSB_TRANSFER_TYPE_INTERRUPT = 3
+};
+
+/** \ingroup misc
+ * Standard requests, as defined in table 9-3 of the USB2 specifications */
+enum libusb_standard_request {
+	/** Request status of the specific recipient */
+	LIBUSB_REQUEST_GET_STATUS = 0x00,
+
+	/** Clear or disable a specific feature */
+	LIBUSB_REQUEST_CLEAR_FEATURE = 0x01,
+
+	/* 0x02 is reserved */
+
+	/** Set or enable a specific feature */
+	LIBUSB_REQUEST_SET_FEATURE = 0x03,
+
+	/* 0x04 is reserved */
+
+	/** Set device address for all future accesses */
+	LIBUSB_REQUEST_SET_ADDRESS = 0x05,
+
+	/** Get the specified descriptor */
+	LIBUSB_REQUEST_GET_DESCRIPTOR = 0x06,
+
+	/** Used to update existing descriptors or add new descriptors */
+	LIBUSB_REQUEST_SET_DESCRIPTOR = 0x07,
+
+	/** Get the current device configuration value */
+	LIBUSB_REQUEST_GET_CONFIGURATION = 0x08,
+
+	/** Set device configuration */
+	LIBUSB_REQUEST_SET_CONFIGURATION = 0x09,
+
+	/** Return the selected alternate setting for the specified interface */
+	LIBUSB_REQUEST_GET_INTERFACE = 0x0A,
+
+	/** Select an alternate interface for the specified interface */
+	LIBUSB_REQUEST_SET_INTERFACE = 0x0B,
+
+	/** Set then report an endpoint's synchronization frame */
+	LIBUSB_REQUEST_SYNCH_FRAME = 0x0C
+};
+
+/** \ingroup misc
+ * Request type bits of the
+ * \ref libusb_control_setup::bmRequestType "bmRequestType" field in control
+ * transfers. */
+enum libusb_request_type {
+	/** Standard */
+	LIBUSB_REQUEST_TYPE_STANDARD = (0x00 << 5),
+
+	/** Class */
+	LIBUSB_REQUEST_TYPE_CLASS = (0x01 << 5),
+
+	/** Vendor */
+	LIBUSB_REQUEST_TYPE_VENDOR = (0x02 << 5),
+
+	/** Reserved */
+	LIBUSB_REQUEST_TYPE_RESERVED = (0x03 << 5)
+};
+
+/** \ingroup misc
+ * Recipient bits of the
+ * \ref libusb_control_setup::bmRequestType "bmRequestType" field in control
+ * transfers. Values 4 through 31 are reserved. */
+enum libusb_request_recipient {
+	/** Device */
+	LIBUSB_RECIPIENT_DEVICE = 0x00,
+
+	/** Interface */
+	LIBUSB_RECIPIENT_INTERFACE = 0x01,
+
+	/** Endpoint */
+	LIBUSB_RECIPIENT_ENDPOINT = 0x02,
+
+	/** Other */
+	LIBUSB_RECIPIENT_OTHER = 0x03
+};
+
+#define LIBUSB_ISO_SYNC_TYPE_MASK		0x0C
+
+/** \ingroup desc
+ * Synchronization type for isochronous endpoints. Values for bits 2:3 of the
+ * \ref libusb_endpoint_descriptor::bmAttributes "bmAttributes" field in
+ * libusb_endpoint_descriptor.
+ */
+enum libusb_iso_sync_type {
+	/** No synchronization */
+	LIBUSB_ISO_SYNC_TYPE_NONE = 0,
+
+	/** Asynchronous */
+	LIBUSB_ISO_SYNC_TYPE_ASYNC = 1,
+
+	/** Adaptive */
+	LIBUSB_ISO_SYNC_TYPE_ADAPTIVE = 2,
+
+	/** Synchronous */
+	LIBUSB_ISO_SYNC_TYPE_SYNC = 3
+};
+
+#define LIBUSB_ISO_USAGE_TYPE_MASK 0x30
+
+/** \ingroup desc
+ * Usage type for isochronous endpoints. Values for bits 4:5 of the
+ * \ref libusb_endpoint_descriptor::bmAttributes "bmAttributes" field in
+ * libusb_endpoint_descriptor.
+ */
+enum libusb_iso_usage_type {
+	/** Data endpoint */
+	LIBUSB_ISO_USAGE_TYPE_DATA = 0,
+
+	/** Feedback endpoint */
+	LIBUSB_ISO_USAGE_TYPE_FEEDBACK = 1,
+
+	/** Implicit feedback Data endpoint */
+	LIBUSB_ISO_USAGE_TYPE_IMPLICIT = 2
+};
+
+/** \ingroup desc
+ * A structure representing the standard USB device descriptor. This
+ * descriptor is documented in section 9.6.1 of the USB 2.0 specification.
+ * All multiple-byte fields are represented in host-endian format.
+ */
+struct libusb_device_descriptor {
+	/** Size of this descriptor (in bytes) */
+	uint8_t  bLength;
+
+	/** Descriptor type. Will have value
+	 * \ref libusb_descriptor_type::LIBUSB_DT_DEVICE LIBUSB_DT_DEVICE in this
+	 * context. */
+	uint8_t  bDescriptorType;
+
+	/** USB specification release number in binary-coded decimal. A value of
+	 * 0x0200 indicates USB 2.0, 0x0110 indicates USB 1.1, etc. */
+	uint16_t bcdUSB;
+
+	/** USB-IF class code for the device. See \ref libusb_class_code. */
+	uint8_t  bDeviceClass;
+
+	/** USB-IF subclass code for the device, qualified by the bDeviceClass
+	 * value */
+	uint8_t  bDeviceSubClass;
+
+	/** USB-IF protocol code for the device, qualified by the bDeviceClass and
+	 * bDeviceSubClass values */
+	uint8_t  bDeviceProtocol;
+
+	/** Maximum packet size for endpoint 0 */
+	uint8_t  bMaxPacketSize0;
+
+	/** USB-IF vendor ID */
+	uint16_t idVendor;
+
+	/** USB-IF product ID */
+	uint16_t idProduct;
+
+	/** Device release number in binary-coded decimal */
+	uint16_t bcdDevice;
+
+	/** Index of string descriptor describing manufacturer */
+	uint8_t  iManufacturer;
+
+	/** Index of string descriptor describing product */
+	uint8_t  iProduct;
+
+	/** Index of string descriptor containing device serial number */
+	uint8_t  iSerialNumber;
+
+	/** Number of possible configurations */
+	uint8_t  bNumConfigurations;
+};
+
+/** \ingroup desc
+ * A structure representing the standard USB endpoint descriptor. This
+ * descriptor is documented in section 9.6.3 of the USB 2.0 specification.
+ * All multiple-byte fields are represented in host-endian format.
+ */
+struct libusb_endpoint_descriptor {
+	/** Size of this descriptor (in bytes) */
+	uint8_t  bLength;
+
+	/** Descriptor type. Will have value
+	 * \ref libusb_descriptor_type::LIBUSB_DT_ENDPOINT LIBUSB_DT_ENDPOINT in
+	 * this context. */
+	uint8_t  bDescriptorType;
+
+	/** The address of the endpoint described by this descriptor. Bits 0:3 are
+	 * the endpoint number. Bits 4:6 are reserved. Bit 7 indicates direction,
+	 * see \ref libusb_endpoint_direction.
+	 */
+	uint8_t  bEndpointAddress;
+
+	/** Attributes which apply to the endpoint when it is configured using
+	 * the bConfigurationValue. Bits 0:1 determine the transfer type and
+	 * correspond to \ref libusb_transfer_type. Bits 2:3 are only used for
+	 * isochronous endpoints and correspond to \ref libusb_iso_sync_type.
+	 * Bits 4:5 are also only used for isochronous endpoints and correspond to
+	 * \ref libusb_iso_usage_type. Bits 6:7 are reserved.
+	 */
+	uint8_t  bmAttributes;
+
+	/** Maximum packet size this endpoint is capable of sending/receiving. */
+	uint16_t wMaxPacketSize;
+
+	/** Interval for polling endpoint for data transfers. */
+	uint8_t  bInterval;
+
+	/** For audio devices only: the rate at which synchronization feedback
+	 * is provided. */
+	uint8_t  bRefresh;
+
+	/** For audio devices only: the address if the synch endpoint */
+	uint8_t  bSynchAddress;
+
+	/** Extra descriptors. If libusb encounters unknown endpoint descriptors,
+	 * it will store them here, should you wish to parse them. */
+	const unsigned char *extra;
+
+	/** Length of the extra descriptors, in bytes. */
+	int extra_length;
+};
+
+/** \ingroup desc
+ * A structure representing the standard USB interface descriptor. This
+ * descriptor is documented in section 9.6.5 of the USB 2.0 specification.
+ * All multiple-byte fields are represented in host-endian format.
+ */
+struct libusb_interface_descriptor {
+	/** Size of this descriptor (in bytes) */
+	uint8_t  bLength;
+
+	/** Descriptor type. Will have value
+	 * \ref libusb_descriptor_type::LIBUSB_DT_INTERFACE LIBUSB_DT_INTERFACE
+	 * in this context. */
+	uint8_t  bDescriptorType;
+
+	/** Number of this interface */
+	uint8_t  bInterfaceNumber;
+
+	/** Value used to select this alternate setting for this interface */
+	uint8_t  bAlternateSetting;
+
+	/** Number of endpoints used by this interface (excluding the control
+	 * endpoint). */
+	uint8_t  bNumEndpoints;
+
+	/** USB-IF class code for this interface. See \ref libusb_class_code. */
+	uint8_t  bInterfaceClass;
+
+	/** USB-IF subclass code for this interface, qualified by the
+	 * bInterfaceClass value */
+	uint8_t  bInterfaceSubClass;
+
+	/** USB-IF protocol code for this interface, qualified by the
+	 * bInterfaceClass and bInterfaceSubClass values */
+	uint8_t  bInterfaceProtocol;
+
+	/** Index of string descriptor describing this interface */
+	uint8_t  iInterface;
+
+	/** Array of endpoint descriptors. This length of this array is determined
+	 * by the bNumEndpoints field. */
+	const struct libusb_endpoint_descriptor *endpoint;
+
+	/** Extra descriptors. If libusb encounters unknown interface descriptors,
+	 * it will store them here, should you wish to parse them. */
+	const unsigned char *extra;
+
+	/** Length of the extra descriptors, in bytes. */
+	int extra_length;
+};
+
+/** \ingroup desc
+ * A collection of alternate settings for a particular USB interface.
+ */
+struct libusb_interface {
+	/** Array of interface descriptors. The length of this array is determined
+	 * by the num_altsetting field. */
+	const struct libusb_interface_descriptor *altsetting;
+
+	/** The number of alternate settings that belong to this interface */
+	int num_altsetting;
+};
+
+/** \ingroup desc
+ * A structure representing the standard USB configuration descriptor. This
+ * descriptor is documented in section 9.6.3 of the USB 2.0 specification.
+ * All multiple-byte fields are represented in host-endian format.
+ */
+struct libusb_config_descriptor {
+	/** Size of this descriptor (in bytes) */
+	uint8_t  bLength;
+
+	/** Descriptor type. Will have value
+	 * \ref libusb_descriptor_type::LIBUSB_DT_CONFIG LIBUSB_DT_CONFIG
+	 * in this context. */
+	uint8_t  bDescriptorType;
+
+	/** Total length of data returned for this configuration */
+	uint16_t wTotalLength;
+
+	/** Number of interfaces supported by this configuration */
+	uint8_t  bNumInterfaces;
+
+	/** Identifier value for this configuration */
+	uint8_t  bConfigurationValue;
+
+	/** Index of string descriptor describing this configuration */
+	uint8_t  iConfiguration;
+
+	/** Configuration characteristics */
+	uint8_t  bmAttributes;
+
+	/** Maximum power consumption of the USB device from this bus in this
+	 * configuration when the device is fully opreation. Expressed in units
+	 * of 2 mA. */
+	uint8_t  MaxPower;
+
+	/** Array of interfaces supported by this configuration. The length of
+	 * this array is determined by the bNumInterfaces field. */
+	const struct libusb_interface *interface;
+
+	/** Extra descriptors. If libusb encounters unknown configuration
+	 * descriptors, it will store them here, should you wish to parse them. */
+	const unsigned char *extra;
+
+	/** Length of the extra descriptors, in bytes. */
+	int extra_length;
+};
+
+/** \ingroup asyncio
+ * Setup packet for control transfers. */
+struct libusb_control_setup {
+	/** Request type. Bits 0:4 determine recipient, see
+	 * \ref libusb_request_recipient. Bits 5:6 determine type, see
+	 * \ref libusb_request_type. Bit 7 determines data transfer direction, see
+	 * \ref libusb_endpoint_direction.
+	 */
+	uint8_t  bmRequestType;
+
+	/** Request. If the type bits of bmRequestType are equal to
+	 * \ref libusb_request_type::LIBUSB_REQUEST_TYPE_STANDARD
+	 * "LIBUSB_REQUEST_TYPE_STANDARD" then this field refers to
+	 * \ref libusb_standard_request. For other cases, use of this field is
+	 * application-specific. */
+	uint8_t  bRequest;
+
+	/** Value. Varies according to request */
+	uint16_t wValue;
+
+	/** Index. Varies according to request, typically used to pass an index
+	 * or offset */
+	uint16_t wIndex;
+
+	/** Number of bytes to transfer */
+	uint16_t wLength;
+};
+
+#define LIBUSB_CONTROL_SETUP_SIZE (sizeof(struct libusb_control_setup))
+
+/* libusb */
+
+struct libusb_context;
+struct libusb_device;
+struct libusb_device_handle;
+
+/** \ingroup lib
+ * Structure representing a libusb session. The concept of individual libusb
+ * sessions allows for your program to use two libraries (or dynamically
+ * load two modules) which both independently use libusb. This will prevent
+ * interference between the individual libusb users - for example
+ * libusb_set_debug() will not affect the other user of the library, and
+ * libusb_exit() will not destroy resources that the other user is still
+ * using.
+ *
+ * Sessions are created by libusb_init() and destroyed through libusb_exit().
+ * If your application is guaranteed to only ever include a single libusb
+ * user (i.e. you), you do not have to worry about contexts: pass NULL in
+ * every function call where a context is required. The default context
+ * will be used.
+ *
+ * For more information, see \ref contexts.
+ */
+typedef struct libusb_context libusb_context;
+
+/** \ingroup dev
+ * Structure representing a USB device detected on the system. This is an
+ * opaque type for which you are only ever provided with a pointer, usually
+ * originating from libusb_get_device_list().
+ *
+ * Certain operations can be performed on a device, but in order to do any
+ * I/O you will have to first obtain a device handle using libusb_open().
+ *
+ * Devices are reference counted with libusb_device_ref() and
+ * libusb_device_unref(), and are freed when the reference count reaches 0.
+ * New devices presented by libusb_get_device_list() have a reference count of
+ * 1, and libusb_free_device_list() can optionally decrease the reference count
+ * on all devices in the list. libusb_open() adds another reference which is
+ * later destroyed by libusb_close().
+ */
+typedef struct libusb_device libusb_device;
+
+
+/** \ingroup dev
+ * Structure representing a handle on a USB device. This is an opaque type for
+ * which you are only ever provided with a pointer, usually originating from
+ * libusb_open().
+ *
+ * A device handle is used to perform I/O and other operations. When finished
+ * with a device handle, you should call libusb_close().
+ */
+typedef struct libusb_device_handle libusb_device_handle;
+
+/** \ingroup misc
+ * Error codes. Most libusb functions return 0 on success or one of these
+ * codes on failure.
+ * You can use libusb_strerror() to retrieve a short string description of
+ * a libusb_error enumeration value.
+ */
+enum libusb_error {
+	/** Success (no error) */
+	LIBUSB_SUCCESS = 0,
+
+	/** Input/output error */
+	LIBUSB_ERROR_IO = -1,
+
+	/** Invalid parameter */
+	LIBUSB_ERROR_INVALID_PARAM = -2,
+
+	/** Access denied (insufficient permissions) */
+	LIBUSB_ERROR_ACCESS = -3,
+
+	/** No such device (it may have been disconnected) */
+	LIBUSB_ERROR_NO_DEVICE = -4,
+
+	/** Entity not found */
+	LIBUSB_ERROR_NOT_FOUND = -5,
+
+	/** Resource busy */
+	LIBUSB_ERROR_BUSY = -6,
+
+	/** Operation timed out */
+	LIBUSB_ERROR_TIMEOUT = -7,
+
+	/** Overflow */
+	LIBUSB_ERROR_OVERFLOW = -8,
+
+	/** Pipe error */
+	LIBUSB_ERROR_PIPE = -9,
+
+	/** System call interrupted (perhaps due to signal) */
+	LIBUSB_ERROR_INTERRUPTED = -10,
+
+	/** Insufficient memory */
+	LIBUSB_ERROR_NO_MEM = -11,
+
+	/** Operation not supported or unimplemented on this platform */
+	LIBUSB_ERROR_NOT_SUPPORTED = -12,
+
+	/** Other error */
+	LIBUSB_ERROR_OTHER = -99
+
+	/* IMPORTANT: when adding new values to this enum, remember to
+	   update the libusb_strerror() function implementation! */
+};
+
+/** \ingroup asyncio
+ * Transfer status codes */
+enum libusb_transfer_status {
+	/** Transfer completed without error. Note that this does not indicate
+	 * that the entire amount of requested data was transferred. */
+	LIBUSB_TRANSFER_COMPLETED,
+
+	/** Transfer failed */
+	LIBUSB_TRANSFER_ERROR,
+
+	/** Transfer timed out */
+	LIBUSB_TRANSFER_TIMED_OUT,
+
+	/** Transfer was cancelled */
+	LIBUSB_TRANSFER_CANCELLED,
+
+	/** For bulk/interrupt endpoints: halt condition detected (endpoint
+	 * stalled). For control endpoints: control request not supported. */
+	LIBUSB_TRANSFER_STALL,
+
+	/** Device was disconnected */
+	LIBUSB_TRANSFER_NO_DEVICE,
+
+	/** Device sent more data than requested */
+	LIBUSB_TRANSFER_OVERFLOW
+};
+
+/** \ingroup asyncio
+ * libusb_transfer.flags values */
+enum libusb_transfer_flags {
+	/** Report short frames as errors */
+	LIBUSB_TRANSFER_SHORT_NOT_OK = 1<<0,
+
+	/** Automatically free() transfer buffer during libusb_free_transfer() */
+	LIBUSB_TRANSFER_FREE_BUFFER = 1<<1,
+
+	/** Automatically call libusb_free_transfer() after callback returns.
+	 * If this flag is set, it is illegal to call libusb_free_transfer()
+	 * from your transfer callback, as this will result in a double-free
+	 * when this flag is acted upon. */
+	LIBUSB_TRANSFER_FREE_TRANSFER = 1<<2
+};
+
+/** \ingroup asyncio
+ * Isochronous packet descriptor. */
+struct libusb_iso_packet_descriptor {
+	/** Length of data to request in this packet */
+	unsigned int length;
+
+	/** Amount of data that was actually transferred */
+	unsigned int actual_length;
+
+	/** Status code for this packet */
+	enum libusb_transfer_status status;
+};
+
+struct libusb_transfer;
+
+/** \ingroup asyncio
+ * Asynchronous transfer callback function type. When submitting asynchronous
+ * transfers, you pass a pointer to a callback function of this type via the
+ * \ref libusb_transfer::callback "callback" member of the libusb_transfer
+ * structure. libusb will call this function later, when the transfer has
+ * completed or failed. See \ref asyncio for more information.
+ * \param transfer The libusb_transfer struct the callback function is being
+ * notified about.
+ */
+typedef void (LIBUSB_CALL *libusb_transfer_cb_fn)(struct libusb_transfer *transfer);
+
+/** \ingroup asyncio
+ * The generic USB transfer structure. The user populates this structure and
+ * then submits it in order to request a transfer. After the transfer has
+ * completed, the library populates the transfer with the results and passes
+ * it back to the user.
+ */
+struct libusb_transfer {
+	/** Handle of the device that this transfer will be submitted to */
+	libusb_device_handle *dev_handle;
+
+	/** A bitwise OR combination of \ref libusb_transfer_flags. */
+	uint8_t flags;
+
+	/** Address of the endpoint where this transfer will be sent. */
+	unsigned char endpoint;
+
+	/** Type of the endpoint from \ref libusb_transfer_type */
+	unsigned char type;
+
+	/** Timeout for this transfer in millseconds. A value of 0 indicates no
+	 * timeout. */
+	unsigned int timeout;
+
+	/** The status of the transfer. Read-only, and only for use within
+	 * transfer callback function.
+	 *
+	 * If this is an isochronous transfer, this field may read COMPLETED even
+	 * if there were errors in the frames. Use the
+	 * \ref libusb_iso_packet_descriptor::status "status" field in each packet
+	 * to determine if errors occurred. */
+	enum libusb_transfer_status status;
+
+	/** Length of the data buffer */
+	int length;
+
+	/** Actual length of data that was transferred. Read-only, and only for
+	 * use within transfer callback function. Not valid for isochronous
+	 * endpoint transfers. */
+	int actual_length;
+
+	/** Callback function. This will be invoked when the transfer completes,
+	 * fails, or is cancelled. */
+	libusb_transfer_cb_fn callback;
+
+	/** User context data to pass to the callback function. */
+	void *user_data;
+
+	/** Data buffer */
+	unsigned char *buffer;
+
+	/** Number of isochronous packets. Only used for I/O with isochronous
+	 * endpoints. */
+	int num_iso_packets;
+
+	/** Isochronous packet descriptors, for isochronous transfers only. */
+	struct libusb_iso_packet_descriptor iso_packet_desc
+#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)
+	[] /* valid C99 code */
+#else
+	[0] /* non-standard, but usually working code */
+#endif
+	;
+};
+
+int LIBUSB_CALL libusb_init(libusb_context **ctx);
+void LIBUSB_CALL libusb_exit(libusb_context *ctx);
+void LIBUSB_CALL libusb_set_debug(libusb_context *ctx, int level);
+const char * LIBUSB_CALL libusb_strerror(enum libusb_error errcode);
+
+ssize_t LIBUSB_CALL libusb_get_device_list(libusb_context *ctx,
+	libusb_device ***list);
+void LIBUSB_CALL libusb_free_device_list(libusb_device **list,
+	int unref_devices);
+libusb_device * LIBUSB_CALL libusb_ref_device(libusb_device *dev);
+void LIBUSB_CALL libusb_unref_device(libusb_device *dev);
+
+int LIBUSB_CALL libusb_get_configuration(libusb_device_handle *dev,
+	int *config);
+int LIBUSB_CALL libusb_get_device_descriptor(libusb_device *dev,
+	struct libusb_device_descriptor *desc);
+int LIBUSB_CALL libusb_get_active_config_descriptor(libusb_device *dev,
+	struct libusb_config_descriptor **config);
+int LIBUSB_CALL libusb_get_config_descriptor(libusb_device *dev,
+	uint8_t config_index, struct libusb_config_descriptor **config);
+int LIBUSB_CALL libusb_get_config_descriptor_by_value(libusb_device *dev,
+	uint8_t bConfigurationValue, struct libusb_config_descriptor **config);
+void LIBUSB_CALL libusb_free_config_descriptor(
+	struct libusb_config_descriptor *config);
+uint8_t LIBUSB_CALL libusb_get_bus_number(libusb_device *dev);
+uint8_t LIBUSB_CALL libusb_get_device_address(libusb_device *dev);
+int LIBUSB_CALL libusb_get_max_packet_size(libusb_device *dev,
+	unsigned char endpoint);
+int LIBUSB_CALL libusb_get_max_iso_packet_size(libusb_device *dev,
+	unsigned char endpoint);
+
+int LIBUSB_CALL libusb_open(libusb_device *dev, libusb_device_handle **handle);
+void LIBUSB_CALL libusb_close(libusb_device_handle *dev_handle);
+libusb_device * LIBUSB_CALL libusb_get_device(libusb_device_handle *dev_handle);
+
+int LIBUSB_CALL libusb_set_configuration(libusb_device_handle *dev,
+	int configuration);
+int LIBUSB_CALL libusb_claim_interface(libusb_device_handle *dev,
+	int interface_number);
+int LIBUSB_CALL libusb_release_interface(libusb_device_handle *dev,
+	int interface_number);
+
+libusb_device_handle * LIBUSB_CALL libusb_open_device_with_vid_pid(
+	libusb_context *ctx, uint16_t vendor_id, uint16_t product_id);
+
+int LIBUSB_CALL libusb_set_interface_alt_setting(libusb_device_handle *dev,
+	int interface_number, int alternate_setting);
+int LIBUSB_CALL libusb_clear_halt(libusb_device_handle *dev,
+	unsigned char endpoint);
+int LIBUSB_CALL libusb_reset_device(libusb_device_handle *dev);
+
+int LIBUSB_CALL libusb_kernel_driver_active(libusb_device_handle *dev,
+	int interface_number);
+int LIBUSB_CALL libusb_detach_kernel_driver(libusb_device_handle *dev,
+	int interface_number);
+int LIBUSB_CALL libusb_attach_kernel_driver(libusb_device_handle *dev,
+	int interface_number);
+
+/* async I/O */
+
+/** \ingroup asyncio
+ * Get the data section of a control transfer. This convenience function is here
+ * to remind you that the data does not start until 8 bytes into the actual
+ * buffer, as the setup packet comes first.
+ *
+ * Calling this function only makes sense from a transfer callback function,
+ * or situations where you have already allocated a suitably sized buffer at
+ * transfer->buffer.
+ *
+ * \param transfer a transfer
+ * \returns pointer to the first byte of the data section
+ */
+static inline unsigned char *libusb_control_transfer_get_data(
+	struct libusb_transfer *transfer)
+{
+	return transfer->buffer + LIBUSB_CONTROL_SETUP_SIZE;
+}
+
+/** \ingroup asyncio
+ * Get the control setup packet of a control transfer. This convenience
+ * function is here to remind you that the control setup occupies the first
+ * 8 bytes of the transfer data buffer.
+ *
+ * Calling this function only makes sense from a transfer callback function,
+ * or situations where you have already allocated a suitably sized buffer at
+ * transfer->buffer.
+ *
+ * \param transfer a transfer
+ * \returns a casted pointer to the start of the transfer data buffer
+ */
+static inline struct libusb_control_setup *libusb_control_transfer_get_setup(
+	struct libusb_transfer *transfer)
+{
+	return (struct libusb_control_setup *) transfer->buffer;
+}
+
+/** \ingroup asyncio
+ * Helper function to populate the setup packet (first 8 bytes of the data
+ * buffer) for a control transfer. The wIndex, wValue and wLength values should
+ * be given in host-endian byte order.
+ *
+ * \param buffer buffer to output the setup packet into
+ * \param bmRequestType see the
+ * \ref libusb_control_setup::bmRequestType "bmRequestType" field of
+ * \ref libusb_control_setup
+ * \param bRequest see the
+ * \ref libusb_control_setup::bRequest "bRequest" field of
+ * \ref libusb_control_setup
+ * \param wValue see the
+ * \ref libusb_control_setup::wValue "wValue" field of
+ * \ref libusb_control_setup
+ * \param wIndex see the
+ * \ref libusb_control_setup::wIndex "wIndex" field of
+ * \ref libusb_control_setup
+ * \param wLength see the
+ * \ref libusb_control_setup::wLength "wLength" field of
+ * \ref libusb_control_setup
+ */
+static inline void libusb_fill_control_setup(unsigned char *buffer,
+	uint8_t bmRequestType, uint8_t bRequest, uint16_t wValue, uint16_t wIndex,
+	uint16_t wLength)
+{
+	struct libusb_control_setup *setup = (struct libusb_control_setup *) buffer;
+	setup->bmRequestType = bmRequestType;
+	setup->bRequest = bRequest;
+	setup->wValue = libusb_cpu_to_le16(wValue);
+	setup->wIndex = libusb_cpu_to_le16(wIndex);
+	setup->wLength = libusb_cpu_to_le16(wLength);
+}
+
+struct libusb_transfer * LIBUSB_CALL libusb_alloc_transfer(int iso_packets);
+int LIBUSB_CALL libusb_submit_transfer(struct libusb_transfer *transfer);
+int LIBUSB_CALL libusb_cancel_transfer(struct libusb_transfer *transfer);
+void LIBUSB_CALL libusb_free_transfer(struct libusb_transfer *transfer);
+
+/** \ingroup asyncio
+ * Helper function to populate the required \ref libusb_transfer fields
+ * for a control transfer.
+ *
+ * If you pass a transfer buffer to this function, the first 8 bytes will
+ * be interpreted as a control setup packet, and the wLength field will be
+ * used to automatically populate the \ref libusb_transfer::length "length"
+ * field of the transfer. Therefore the recommended approach is:
+ * -# Allocate a suitably sized data buffer (including space for control setup)
+ * -# Call libusb_fill_control_setup()
+ * -# If this is a host-to-device transfer with a data stage, put the data
+ *    in place after the setup packet
+ * -# Call this function
+ * -# Call libusb_submit_transfer()
+ *
+ * It is also legal to pass a NULL buffer to this function, in which case this
+ * function will not attempt to populate the length field. Remember that you
+ * must then populate the buffer and length fields later.
+ *
+ * \param transfer the transfer to populate
+ * \param dev_handle handle of the device that will handle the transfer
+ * \param buffer data buffer. If provided, this function will interpret the
+ * first 8 bytes as a setup packet and infer the transfer length from that.
+ * \param callback callback function to be invoked on transfer completion
+ * \param user_data user data to pass to callback function
+ * \param timeout timeout for the transfer in milliseconds
+ */
+static inline void libusb_fill_control_transfer(
+	struct libusb_transfer *transfer, libusb_device_handle *dev_handle,
+	unsigned char *buffer, libusb_transfer_cb_fn callback, void *user_data,
+	unsigned int timeout)
+{
+	struct libusb_control_setup *setup = (struct libusb_control_setup *) buffer;
+	transfer->dev_handle = dev_handle;
+	transfer->endpoint = 0;
+	transfer->type = LIBUSB_TRANSFER_TYPE_CONTROL;
+	transfer->timeout = timeout;
+	transfer->buffer = buffer;
+	if (setup)
+		transfer->length = LIBUSB_CONTROL_SETUP_SIZE
+			+ libusb_le16_to_cpu(setup->wLength);
+	transfer->user_data = user_data;
+	transfer->callback = callback;
+}
+
+/** \ingroup asyncio
+ * Helper function to populate the required \ref libusb_transfer fields
+ * for a bulk transfer.
+ *
+ * \param transfer the transfer to populate
+ * \param dev_handle handle of the device that will handle the transfer
+ * \param endpoint address of the endpoint where this transfer will be sent
+ * \param buffer data buffer
+ * \param length length of data buffer
+ * \param callback callback function to be invoked on transfer completion
+ * \param user_data user data to pass to callback function
+ * \param timeout timeout for the transfer in milliseconds
+ */
+static inline void libusb_fill_bulk_transfer(struct libusb_transfer *transfer,
+	libusb_device_handle *dev_handle, unsigned char endpoint,
+	unsigned char *buffer, int length, libusb_transfer_cb_fn callback,
+	void *user_data, unsigned int timeout)
+{
+	transfer->dev_handle = dev_handle;
+	transfer->endpoint = endpoint;
+	transfer->type = LIBUSB_TRANSFER_TYPE_BULK;
+	transfer->timeout = timeout;
+	transfer->buffer = buffer;
+	transfer->length = length;
+	transfer->user_data = user_data;
+	transfer->callback = callback;
+}
+
+/** \ingroup asyncio
+ * Helper function to populate the required \ref libusb_transfer fields
+ * for an interrupt transfer.
+ *
+ * \param transfer the transfer to populate
+ * \param dev_handle handle of the device that will handle the transfer
+ * \param endpoint address of the endpoint where this transfer will be sent
+ * \param buffer data buffer
+ * \param length length of data buffer
+ * \param callback callback function to be invoked on transfer completion
+ * \param user_data user data to pass to callback function
+ * \param timeout timeout for the transfer in milliseconds
+ */
+static inline void libusb_fill_interrupt_transfer(
+	struct libusb_transfer *transfer, libusb_device_handle *dev_handle,
+	unsigned char endpoint, unsigned char *buffer, int length,
+	libusb_transfer_cb_fn callback, void *user_data, unsigned int timeout)
+{
+	transfer->dev_handle = dev_handle;
+	transfer->endpoint = endpoint;
+	transfer->type = LIBUSB_TRANSFER_TYPE_INTERRUPT;
+	transfer->timeout = timeout;
+	transfer->buffer = buffer;
+	transfer->length = length;
+	transfer->user_data = user_data;
+	transfer->callback = callback;
+}
+
+/** \ingroup asyncio
+ * Helper function to populate the required \ref libusb_transfer fields
+ * for an isochronous transfer.
+ *
+ * \param transfer the transfer to populate
+ * \param dev_handle handle of the device that will handle the transfer
+ * \param endpoint address of the endpoint where this transfer will be sent
+ * \param buffer data buffer
+ * \param length length of data buffer
+ * \param num_iso_packets the number of isochronous packets
+ * \param callback callback function to be invoked on transfer completion
+ * \param user_data user data to pass to callback function
+ * \param timeout timeout for the transfer in milliseconds
+ */
+static inline void libusb_fill_iso_transfer(struct libusb_transfer *transfer,
+	libusb_device_handle *dev_handle, unsigned char endpoint,
+	unsigned char *buffer, int length, int num_iso_packets,
+	libusb_transfer_cb_fn callback, void *user_data, unsigned int timeout)
+{
+	transfer->dev_handle = dev_handle;
+	transfer->endpoint = endpoint;
+	transfer->type = LIBUSB_TRANSFER_TYPE_ISOCHRONOUS;
+	transfer->timeout = timeout;
+	transfer->buffer = buffer;
+	transfer->length = length;
+	transfer->num_iso_packets = num_iso_packets;
+	transfer->user_data = user_data;
+	transfer->callback = callback;
+}
+
+/** \ingroup asyncio
+ * Convenience function to set the length of all packets in an isochronous
+ * transfer, based on the num_iso_packets field in the transfer structure.
+ *
+ * \param transfer a transfer
+ * \param length the length to set in each isochronous packet descriptor
+ * \see libusb_get_max_packet_size()
+ */
+static inline void libusb_set_iso_packet_lengths(
+	struct libusb_transfer *transfer, unsigned int length)
+{
+	int i;
+	for (i = 0; i < transfer->num_iso_packets; i++)
+		transfer->iso_packet_desc[i].length = length;
+}
+
+/** \ingroup asyncio
+ * Convenience function to locate the position of an isochronous packet
+ * within the buffer of an isochronous transfer.
+ *
+ * This is a thorough function which loops through all preceding packets,
+ * accumulating their lengths to find the position of the specified packet.
+ * Typically you will assign equal lengths to each packet in the transfer,
+ * and hence the above method is sub-optimal. You may wish to use
+ * libusb_get_iso_packet_buffer_simple() instead.
+ *
+ * \param transfer a transfer
+ * \param packet the packet to return the address of
+ * \returns the base address of the packet buffer inside the transfer buffer,
+ * or NULL if the packet does not exist.
+ * \see libusb_get_iso_packet_buffer_simple()
+ */
+static inline unsigned char *libusb_get_iso_packet_buffer(
+	struct libusb_transfer *transfer, unsigned int packet)
+{
+	int i;
+	size_t offset = 0;
+	int _packet;
+
+	/* oops..slight bug in the API. packet is an unsigned int, but we use
+	 * signed integers almost everywhere else. range-check and convert to
+	 * signed to avoid compiler warnings. FIXME for libusb-2. */
+	if (packet > INT_MAX)
+		return NULL;
+	_packet = packet;
+
+	if (_packet >= transfer->num_iso_packets)
+		return NULL;
+
+	for (i = 0; i < _packet; i++)
+		offset += transfer->iso_packet_desc[i].length;
+
+	return transfer->buffer + offset;
+}
+
+/** \ingroup asyncio
+ * Convenience function to locate the position of an isochronous packet
+ * within the buffer of an isochronous transfer, for transfers where each
+ * packet is of identical size.
+ *
+ * This function relies on the assumption that every packet within the transfer
+ * is of identical size to the first packet. Calculating the location of
+ * the packet buffer is then just a simple calculation:
+ * <tt>buffer + (packet_size * packet)</tt>
+ *
+ * Do not use this function on transfers other than those that have identical
+ * packet lengths for each packet.
+ *
+ * \param transfer a transfer
+ * \param packet the packet to return the address of
+ * \returns the base address of the packet buffer inside the transfer buffer,
+ * or NULL if the packet does not exist.
+ * \see libusb_get_iso_packet_buffer()
+ */
+static inline unsigned char *libusb_get_iso_packet_buffer_simple(
+	struct libusb_transfer *transfer, unsigned int packet)
+{
+	int _packet;
+
+	/* oops..slight bug in the API. packet is an unsigned int, but we use
+	 * signed integers almost everywhere else. range-check and convert to
+	 * signed to avoid compiler warnings. FIXME for libusb-2. */
+	if (packet > INT_MAX)
+		return NULL;
+	_packet = packet;
+
+	if (_packet >= transfer->num_iso_packets)
+		return NULL;
+
+	return transfer->buffer + (transfer->iso_packet_desc[0].length * _packet);
+}
+
+/* sync I/O */
+
+int LIBUSB_CALL libusb_control_transfer(libusb_device_handle *dev_handle,
+	uint8_t request_type, uint8_t bRequest, uint16_t wValue, uint16_t wIndex,
+	unsigned char *data, uint16_t wLength, unsigned int timeout);
+
+int LIBUSB_CALL libusb_bulk_transfer(libusb_device_handle *dev_handle,
+	unsigned char endpoint, unsigned char *data, int length,
+	int *actual_length, unsigned int timeout);
+
+int LIBUSB_CALL libusb_interrupt_transfer(libusb_device_handle *dev_handle,
+	unsigned char endpoint, unsigned char *data, int length,
+	int *actual_length, unsigned int timeout);
+
+/** \ingroup desc
+ * Retrieve a descriptor from the default control pipe.
+ * This is a convenience function which formulates the appropriate control
+ * message to retrieve the descriptor.
+ *
+ * \param dev a device handle
+ * \param desc_type the descriptor type, see \ref libusb_descriptor_type
+ * \param desc_index the index of the descriptor to retrieve
+ * \param data output buffer for descriptor
+ * \param length size of data buffer
+ * \returns number of bytes returned in data, or LIBUSB_ERROR code on failure
+ */
+static inline int libusb_get_descriptor(libusb_device_handle *dev,
+	uint8_t desc_type, uint8_t desc_index, unsigned char *data, int length)
+{
+	return libusb_control_transfer(dev, LIBUSB_ENDPOINT_IN,
+		LIBUSB_REQUEST_GET_DESCRIPTOR, (desc_type << 8) | desc_index, 0, data,
+		(uint16_t) length, 1000);
+}
+
+/** \ingroup desc
+ * Retrieve a descriptor from a device.
+ * This is a convenience function which formulates the appropriate control
+ * message to retrieve the descriptor. The string returned is Unicode, as
+ * detailed in the USB specifications.
+ *
+ * \param dev a device handle
+ * \param desc_index the index of the descriptor to retrieve
+ * \param langid the language ID for the string descriptor
+ * \param data output buffer for descriptor
+ * \param length size of data buffer
+ * \returns number of bytes returned in data, or LIBUSB_ERROR code on failure
+ * \see libusb_get_string_descriptor_ascii()
+ */
+static inline int libusb_get_string_descriptor(libusb_device_handle *dev,
+	uint8_t desc_index, uint16_t langid, unsigned char *data, int length)
+{
+	return libusb_control_transfer(dev, LIBUSB_ENDPOINT_IN,
+		LIBUSB_REQUEST_GET_DESCRIPTOR, (LIBUSB_DT_STRING << 8) | desc_index,
+		langid, data, (uint16_t) length, 1000);
+}
+
+int LIBUSB_CALL libusb_get_string_descriptor_ascii(libusb_device_handle *dev,
+	uint8_t desc_index, unsigned char *data, int length);
+
+/* polling and timeouts */
+
+int LIBUSB_CALL libusb_try_lock_events(libusb_context *ctx);
+void LIBUSB_CALL libusb_lock_events(libusb_context *ctx);
+void LIBUSB_CALL libusb_unlock_events(libusb_context *ctx);
+int LIBUSB_CALL libusb_event_handling_ok(libusb_context *ctx);
+int LIBUSB_CALL libusb_event_handler_active(libusb_context *ctx);
+void LIBUSB_CALL libusb_lock_event_waiters(libusb_context *ctx);
+void LIBUSB_CALL libusb_unlock_event_waiters(libusb_context *ctx);
+int LIBUSB_CALL libusb_wait_for_event(libusb_context *ctx, struct timeval *tv);
+
+int LIBUSB_CALL libusb_handle_events_timeout(libusb_context *ctx,
+	struct timeval *tv);
+int LIBUSB_CALL libusb_handle_events(libusb_context *ctx);
+int LIBUSB_CALL libusb_handle_events_locked(libusb_context *ctx,
+	struct timeval *tv);
+int LIBUSB_CALL libusb_pollfds_handle_timeouts(libusb_context *ctx);
+int LIBUSB_CALL libusb_get_next_timeout(libusb_context *ctx,
+	struct timeval *tv);
+
+/** \ingroup poll
+ * File descriptor for polling
+ */
+struct libusb_pollfd {
+	/** Numeric file descriptor */
+	int fd;
+
+	/** Event flags to poll for from <poll.h>. POLLIN indicates that you
+	 * should monitor this file descriptor for becoming ready to read from,
+	 * and POLLOUT indicates that you should monitor this file descriptor for
+	 * nonblocking write readiness. */
+	short events;
+};
+
+/** \ingroup poll
+ * Callback function, invoked when a new file descriptor should be added
+ * to the set of file descriptors monitored for events.
+ * \param fd the new file descriptor
+ * \param events events to monitor for, see \ref libusb_pollfd for a
+ * description
+ * \param user_data User data pointer specified in
+ * libusb_set_pollfd_notifiers() call
+ * \see libusb_set_pollfd_notifiers()
+ */
+typedef void (LIBUSB_CALL *libusb_pollfd_added_cb)(int fd, short events,
+	void *user_data);
+
+/** \ingroup poll
+ * Callback function, invoked when a file descriptor should be removed from
+ * the set of file descriptors being monitored for events. After returning
+ * from this callback, do not use that file descriptor again.
+ * \param fd the file descriptor to stop monitoring
+ * \param user_data User data pointer specified in
+ * libusb_set_pollfd_notifiers() call
+ * \see libusb_set_pollfd_notifiers()
+ */
+typedef void (LIBUSB_CALL *libusb_pollfd_removed_cb)(int fd, void *user_data);
+
+const struct libusb_pollfd ** LIBUSB_CALL libusb_get_pollfds(
+	libusb_context *ctx);
+void LIBUSB_CALL libusb_set_pollfd_notifiers(libusb_context *ctx,
+	libusb_pollfd_added_cb added_cb, libusb_pollfd_removed_cb removed_cb,
+	void *user_data);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/include/libusb-1.0/os/libusbi.h b/include/libusb-1.0/os/libusbi.h
new file mode 100644
index 0000000..9b2fa70
--- /dev/null
+++ b/include/libusb-1.0/os/libusbi.h
@@ -0,0 +1,872 @@
+/*
+ * Internal header for libusb
+ * Copyright (C) 2007-2009 Daniel Drake <dsd@gentoo.org>
+ * Copyright (c) 2001 Johannes Erdfelt <johannes@erdfelt.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef __LIBUSBI_H__
+#define __LIBUSBI_H__
+
+#include <config.h>
+
+#include <stddef.h>
+#include <stdint.h>
+#include <time.h>
+
+#include <libusb.h>
+
+/* Inside the libusb code, mark all public functions as follows:
+ *   return_type API_EXPORTED function_name(params) { ... }
+ * But if the function returns a pointer, mark it as follows:
+ *   DEFAULT_VISIBILITY return_type * LIBUSB_CALL function_name(params) { ... }
+ * In the libusb public header, mark all declarations as:
+ *   return_type LIBUSB_CALL function_name(params);
+ */
+#define API_EXPORTED LIBUSB_CALL DEFAULT_VISIBILITY
+
+#define DEVICE_DESC_LENGTH		18
+
+#define USB_MAXENDPOINTS	32
+#define USB_MAXINTERFACES	32
+#define USB_MAXCONFIG		8
+
+struct list_head {
+	struct list_head *prev, *next;
+};
+
+/* Get an entry from the list
+ * 	ptr - the address of this list_head element in "type"
+ * 	type - the data type that contains "member"
+ * 	member - the list_head element in "type"
+ */
+#define list_entry(ptr, type, member) \
+	((type *)((uintptr_t)(ptr) - (uintptr_t)(&((type *)0L)->member)))
+
+/* Get each entry from a list
+ *	pos - A structure pointer has a "member" element
+ *	head - list head
+ *	member - the list_head element in "pos"
+ *	type - the type of the first parameter
+ */
+#define list_for_each_entry(pos, head, member, type)			\
+	for (pos = list_entry((head)->next, type, member);			\
+		 &pos->member != (head);								\
+		 pos = list_entry(pos->member.next, type, member))
+
+#define list_for_each_entry_safe(pos, n, head, member, type)	\
+	for (pos = list_entry((head)->next, type, member),			\
+		 n = list_entry(pos->member.next, type, member);		\
+		 &pos->member != (head);								\
+		 pos = n, n = list_entry(n->member.next, type, member))
+
+#define list_empty(entry) ((entry)->next == (entry))
+
+static inline void list_init(struct list_head *entry)
+{
+	entry->prev = entry->next = entry;
+}
+
+static inline void list_add(struct list_head *entry, struct list_head *head)
+{
+	entry->next = head->next;
+	entry->prev = head;
+
+	head->next->prev = entry;
+	head->next = entry;
+}
+
+static inline void list_add_tail(struct list_head *entry,
+	struct list_head *head)
+{
+	entry->next = head;
+	entry->prev = head->prev;
+
+	head->prev->next = entry;
+	head->prev = entry;
+}
+
+static inline void list_del(struct list_head *entry)
+{
+	entry->next->prev = entry->prev;
+	entry->prev->next = entry->next;
+}
+
+#define container_of(ptr, type, member) ({                      \
+        const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
+        (type *)( (char *)__mptr - offsetof(type,member) );})
+
+#define MIN(a, b)	((a) < (b) ? (a) : (b))
+#define MAX(a, b)	((a) > (b) ? (a) : (b))
+
+#define TIMESPEC_IS_SET(ts) ((ts)->tv_sec != 0 || (ts)->tv_nsec != 0)
+
+enum usbi_log_level {
+	LOG_LEVEL_DEBUG,
+	LOG_LEVEL_INFO,
+	LOG_LEVEL_WARNING,
+	LOG_LEVEL_ERROR,
+};
+
+void usbi_log(struct libusb_context *ctx, enum usbi_log_level level,
+	const char *function, const char *format, ...);
+
+#if !defined(_MSC_VER) || _MSC_VER > 1200
+
+#ifdef ENABLE_LOGGING
+#define _usbi_log(ctx, level, ...) usbi_log(ctx, level, __FUNCTION__, __VA_ARGS__)
+#else
+#define _usbi_log(ctx, level, ...)
+#endif
+
+#ifdef ENABLE_DEBUG_LOGGING
+#define usbi_dbg(...) _usbi_log(NULL, LOG_LEVEL_DEBUG, __VA_ARGS__)
+#else
+#define usbi_dbg(...)
+#endif
+
+#define usbi_info(ctx, ...) _usbi_log(ctx, LOG_LEVEL_INFO, __VA_ARGS__)
+#define usbi_warn(ctx, ...) _usbi_log(ctx, LOG_LEVEL_WARNING, __VA_ARGS__)
+#define usbi_err(ctx, ...) _usbi_log(ctx, LOG_LEVEL_ERROR, __VA_ARGS__)
+
+#else /* !defined(_MSC_VER) || _MSC_VER > 1200 */
+
+void usbi_log_v(struct libusb_context *ctx, enum usbi_log_level level,
+	const char *function, const char *format, va_list args);
+
+#ifdef ENABLE_LOGGING
+#define LOG_BODY(ctxt, level) \
+{                             \
+	va_list args;             \
+	va_start (args, format);  \
+	usbi_log_v(ctxt, level, "", format, args); \
+	va_end(args);             \
+}
+#else
+#define LOG_BODY(ctxt, level) { }
+#endif
+
+static inline void usbi_info(struct libusb_context *ctx, const char *format,
+	...)
+	LOG_BODY(ctx,LOG_LEVEL_INFO)
+static inline void usbi_warn(struct libusb_context *ctx, const char *format,
+	...)
+	LOG_BODY(ctx,LOG_LEVEL_WARNING)
+static inline void usbi_err( struct libusb_context *ctx, const char *format,
+	...)
+	LOG_BODY(ctx,LOG_LEVEL_ERROR)
+
+static inline void usbi_dbg(const char *format, ...)
+#ifdef ENABLE_DEBUG_LOGGING
+	LOG_BODY(NULL,LOG_LEVEL_DEBUG)
+#else
+{ }
+#endif
+
+#endif /* !defined(_MSC_VER) || _MSC_VER > 1200 */
+
+#define USBI_GET_CONTEXT(ctx) if (!(ctx)) (ctx) = usbi_default_context
+#define DEVICE_CTX(dev) ((dev)->ctx)
+#define HANDLE_CTX(handle) (DEVICE_CTX((handle)->dev))
+#define TRANSFER_CTX(transfer) (HANDLE_CTX((transfer)->dev_handle))
+#define ITRANSFER_CTX(transfer) \
+	(TRANSFER_CTX(__USBI_TRANSFER_TO_LIBUSB_TRANSFER(transfer)))
+
+/* Internal abstractions for thread synchronization and poll */
+#if defined(THREADS_POSIX)
+#include <os/threads_posix.h>
+#elif defined(OS_WINDOWS)
+#include <os/threads_windows.h>
+#endif
+
+#if defined(OS_LINUX) || defined(OS_DARWIN)
+#include <os/poll_posix.h>
+#elif defined(OS_WINDOWS)
+#include <os/poll_windows.h>
+#endif
+
+extern struct libusb_context *usbi_default_context;
+
+struct libusb_context {
+	int debug;
+	int debug_fixed;
+
+	/* internal control pipe, used for interrupting event handling when
+	 * something needs to modify poll fds. */
+	int ctrl_pipe[2];
+
+	struct list_head usb_devs;
+	usbi_mutex_t usb_devs_lock;
+
+	/* A list of open handles. Backends are free to traverse this if required.
+	 */
+	struct list_head open_devs;
+	usbi_mutex_t open_devs_lock;
+
+	/* this is a list of in-flight transfer handles, sorted by timeout
+	 * expiration. URBs to timeout the soonest are placed at the beginning of
+	 * the list, URBs that will time out later are placed after, and urbs with
+	 * infinite timeout are always placed at the very end. */
+	struct list_head flying_transfers;
+	usbi_mutex_t flying_transfers_lock;
+
+	/* list of poll fds */
+	struct list_head pollfds;
+	usbi_mutex_t pollfds_lock;
+
+	/* a counter that is set when we want to interrupt event handling, in order
+	 * to modify the poll fd set. and a lock to protect it. */
+	unsigned int pollfd_modify;
+	usbi_mutex_t pollfd_modify_lock;
+
+	/* user callbacks for pollfd changes */
+	libusb_pollfd_added_cb fd_added_cb;
+	libusb_pollfd_removed_cb fd_removed_cb;
+	void *fd_cb_user_data;
+
+	/* ensures that only one thread is handling events at any one time */
+	usbi_mutex_t events_lock;
+
+	/* used to see if there is an active thread doing event handling */
+	int event_handler_active;
+
+	/* used to wait for event completion in threads other than the one that is
+	 * event handling */
+	usbi_mutex_t event_waiters_lock;
+	usbi_cond_t event_waiters_cond;
+
+#ifdef USBI_TIMERFD_AVAILABLE
+	/* used for timeout handling, if supported by OS.
+	 * this timerfd is maintained to trigger on the next pending timeout */
+	int timerfd;
+#endif
+};
+
+#ifdef USBI_TIMERFD_AVAILABLE
+#define usbi_using_timerfd(ctx) ((ctx)->timerfd >= 0)
+#else
+#define usbi_using_timerfd(ctx) (0)
+#endif
+
+struct libusb_device {
+	/* lock protects refcnt, everything else is finalized at initialization
+	 * time */
+	usbi_mutex_t lock;
+	int refcnt;
+
+	struct libusb_context *ctx;
+
+	uint8_t bus_number;
+	uint8_t device_address;
+	uint8_t num_configurations;
+
+	struct list_head list;
+	unsigned long session_data;
+	unsigned char os_priv[0];
+};
+
+struct libusb_device_handle {
+	/* lock protects claimed_interfaces */
+	usbi_mutex_t lock;
+	unsigned long claimed_interfaces;
+
+	struct list_head list;
+	struct libusb_device *dev;
+	unsigned char os_priv[0];
+};
+
+#define USBI_TRANSFER_TIMED_OUT	 			(1<<0)
+
+enum {
+  USBI_CLOCK_MONOTONIC,
+  USBI_CLOCK_REALTIME
+};
+
+/* in-memory transfer layout:
+ *
+ * 1. struct usbi_transfer
+ * 2. struct libusb_transfer (which includes iso packets) [variable size]
+ * 3. os private data [variable size]
+ *
+ * from a libusb_transfer, you can get the usbi_transfer by rewinding the
+ * appropriate number of bytes.
+ * the usbi_transfer includes the number of allocated packets, so you can
+ * determine the size of the transfer and hence the start and length of the
+ * OS-private data.
+ */
+
+struct usbi_transfer {
+	int num_iso_packets;
+	struct list_head list;
+	struct timeval timeout;
+	int transferred;
+	uint8_t flags;
+
+	/* this lock is held during libusb_submit_transfer() and
+	 * libusb_cancel_transfer() (allowing the OS backend to prevent duplicate
+	 * cancellation, submission-during-cancellation, etc). the OS backend
+	 * should also take this lock in the handle_events path, to prevent the user
+	 * cancelling the transfer from another thread while you are processing
+	 * its completion (presumably there would be races within your OS backend
+	 * if this were possible). */
+	usbi_mutex_t lock;
+};
+
+#define __USBI_TRANSFER_TO_LIBUSB_TRANSFER(transfer) \
+	((struct libusb_transfer *)(((unsigned char *)(transfer)) \
+		+ sizeof(struct usbi_transfer)))
+#define __LIBUSB_TRANSFER_TO_USBI_TRANSFER(transfer) \
+	((struct usbi_transfer *)(((unsigned char *)(transfer)) \
+		- sizeof(struct usbi_transfer)))
+
+static inline void *usbi_transfer_get_os_priv(struct usbi_transfer *transfer)
+{
+	return ((unsigned char *)transfer) + sizeof(struct usbi_transfer)
+		+ sizeof(struct libusb_transfer)
+		+ (transfer->num_iso_packets
+			* sizeof(struct libusb_iso_packet_descriptor));
+}
+
+/* bus structures */
+
+/* All standard descriptors have these 2 fields in common */
+struct usb_descriptor_header {
+	uint8_t  bLength;
+	uint8_t  bDescriptorType;
+};
+
+/* shared data and functions */
+
+int usbi_io_init(struct libusb_context *ctx);
+void usbi_io_exit(struct libusb_context *ctx);
+
+struct libusb_device *usbi_alloc_device(struct libusb_context *ctx,
+	unsigned long session_id);
+struct libusb_device *usbi_get_device_by_session_id(struct libusb_context *ctx,
+	unsigned long session_id);
+int usbi_sanitize_device(struct libusb_device *dev);
+void usbi_handle_disconnect(struct libusb_device_handle *handle);
+
+int usbi_handle_transfer_completion(struct usbi_transfer *itransfer,
+	enum libusb_transfer_status status);
+int usbi_handle_transfer_cancellation(struct usbi_transfer *transfer);
+
+int usbi_parse_descriptor(unsigned char *source, char *descriptor, void *dest,
+	int host_endian);
+int usbi_get_config_index_by_value(struct libusb_device *dev,
+	uint8_t bConfigurationValue, int *idx);
+
+/* polling */
+
+struct usbi_pollfd {
+	/* must come first */
+	struct libusb_pollfd pollfd;
+
+	struct list_head list;
+};
+
+int usbi_add_pollfd(struct libusb_context *ctx, int fd, short events);
+void usbi_remove_pollfd(struct libusb_context *ctx, int fd);
+void usbi_fd_notification(struct libusb_context *ctx);
+
+/* device discovery */
+
+/* we traverse usbfs without knowing how many devices we are going to find.
+ * so we create this discovered_devs model which is similar to a linked-list
+ * which grows when required. it can be freed once discovery has completed,
+ * eliminating the need for a list node in the libusb_device structure
+ * itself. */
+struct discovered_devs {
+	size_t len;
+	size_t capacity;
+	struct libusb_device *devices[0];
+};
+
+struct discovered_devs *discovered_devs_append(
+	struct discovered_devs *discdevs, struct libusb_device *dev);
+
+/* OS abstraction */
+
+/* This is the interface that OS backends need to implement.
+ * All fields are mandatory, except ones explicitly noted as optional. */
+struct usbi_os_backend {
+	/* A human-readable name for your backend, e.g. "Linux usbfs" */
+	const char *name;
+
+	/* Perform initialization of your backend. You might use this function
+	 * to determine specific capabilities of the system, allocate required
+	 * data structures for later, etc.
+	 *
+	 * This function is called when a libusb user initializes the library
+	 * prior to use.
+	 *
+	 * Return 0 on success, or a LIBUSB_ERROR code on failure.
+	 */
+	int (*init)(struct libusb_context *ctx);
+
+	/* Deinitialization. Optional. This function should destroy anything
+	 * that was set up by init.
+	 *
+	 * This function is called when the user deinitializes the library.
+	 */
+	void (*exit)(void);
+
+	/* Enumerate all the USB devices on the system, returning them in a list
+	 * of discovered devices.
+	 *
+	 * Your implementation should enumerate all devices on the system,
+	 * regardless of whether they have been seen before or not.
+	 *
+	 * When you have found a device, compute a session ID for it. The session
+	 * ID should uniquely represent that particular device for that particular
+	 * connection session since boot (i.e. if you disconnect and reconnect a
+	 * device immediately after, it should be assigned a different session ID).
+	 * If your OS cannot provide a unique session ID as described above,
+	 * presenting a session ID of (bus_number << 8 | device_address) should
+	 * be sufficient. Bus numbers and device addresses wrap and get reused,
+	 * but that is an unlikely case.
+	 *
+	 * After computing a session ID for a device, call
+	 * usbi_get_device_by_session_id(). This function checks if libusb already
+	 * knows about the device, and if so, it provides you with a libusb_device
+	 * structure for it.
+	 *
+	 * If usbi_get_device_by_session_id() returns NULL, it is time to allocate
+	 * a new device structure for the device. Call usbi_alloc_device() to
+	 * obtain a new libusb_device structure with reference count 1. Populate
+	 * the bus_number and device_address attributes of the new device, and
+	 * perform any other internal backend initialization you need to do. At
+	 * this point, you should be ready to provide device descriptors and so
+	 * on through the get_*_descriptor functions. Finally, call
+	 * usbi_sanitize_device() to perform some final sanity checks on the
+	 * device. Assuming all of the above succeeded, we can now continue.
+	 * If any of the above failed, remember to unreference the device that
+	 * was returned by usbi_alloc_device().
+	 *
+	 * At this stage we have a populated libusb_device structure (either one
+	 * that was found earlier, or one that we have just allocated and
+	 * populated). This can now be added to the discovered devices list
+	 * using discovered_devs_append(). Note that discovered_devs_append()
+	 * may reallocate the list, returning a new location for it, and also
+	 * note that reallocation can fail. Your backend should handle these
+	 * error conditions appropriately.
+	 *
+	 * This function should not generate any bus I/O and should not block.
+	 * If I/O is required (e.g. reading the active configuration value), it is
+	 * OK to ignore these suggestions :)
+	 *
+	 * This function is executed when the user wishes to retrieve a list
+	 * of USB devices connected to the system.
+	 *
+	 * Return 0 on success, or a LIBUSB_ERROR code on failure.
+	 */
+	int (*get_device_list)(struct libusb_context *ctx,
+		struct discovered_devs **discdevs);
+
+	/* Open a device for I/O and other USB operations. The device handle
+	 * is preallocated for you, you can retrieve the device in question
+	 * through handle->dev.
+	 *
+	 * Your backend should allocate any internal resources required for I/O
+	 * and other operations so that those operations can happen (hopefully)
+	 * without hiccup. This is also a good place to inform libusb that it
+	 * should monitor certain file descriptors related to this device -
+	 * see the usbi_add_pollfd() function.
+	 *
+	 * This function should not generate any bus I/O and should not block.
+	 *
+	 * This function is called when the user attempts to obtain a device
+	 * handle for a device.
+	 *
+	 * Return:
+	 * - 0 on success
+	 * - LIBUSB_ERROR_ACCESS if the user has insufficient permissions
+	 * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since
+	 *   discovery
+	 * - another LIBUSB_ERROR code on other failure
+	 *
+	 * Do not worry about freeing the handle on failed open, the upper layers
+	 * do this for you.
+	 */
+	int (*open)(struct libusb_device_handle *handle);
+
+	/* Close a device such that the handle cannot be used again. Your backend
+	 * should destroy any resources that were allocated in the open path.
+	 * This may also be a good place to call usbi_remove_pollfd() to inform
+	 * libusb of any file descriptors associated with this device that should
+	 * no longer be monitored.
+	 *
+	 * This function is called when the user closes a device handle.
+	 */
+	void (*close)(struct libusb_device_handle *handle);
+
+	/* Retrieve the device descriptor from a device.
+	 *
+	 * The descriptor should be retrieved from memory, NOT via bus I/O to the
+	 * device. This means that you may have to cache it in a private structure
+	 * during get_device_list enumeration. Alternatively, you may be able
+	 * to retrieve it from a kernel interface (some Linux setups can do this)
+	 * still without generating bus I/O.
+	 *
+	 * This function is expected to write DEVICE_DESC_LENGTH (18) bytes into
+	 * buffer, which is guaranteed to be big enough.
+	 *
+	 * This function is called when sanity-checking a device before adding
+	 * it to the list of discovered devices, and also when the user requests
+	 * to read the device descriptor.
+	 *
+	 * This function is expected to return the descriptor in bus-endian format
+	 * (LE). If it returns the multi-byte values in host-endian format,
+	 * set the host_endian output parameter to "1".
+	 *
+	 * Return 0 on success or a LIBUSB_ERROR code on failure.
+	 */
+	int (*get_device_descriptor)(struct libusb_device *device,
+		unsigned char *buffer, int *host_endian);
+
+	/* Get the ACTIVE configuration descriptor for a device.
+	 *
+	 * The descriptor should be retrieved from memory, NOT via bus I/O to the
+	 * device. This means that you may have to cache it in a private structure
+	 * during get_device_list enumeration. You may also have to keep track
+	 * of which configuration is active when the user changes it.
+	 *
+	 * This function is expected to write len bytes of data into buffer, which
+	 * is guaranteed to be big enough. If you can only do a partial write,
+	 * return an error code.
+	 *
+	 * This function is expected to return the descriptor in bus-endian format
+	 * (LE). If it returns the multi-byte values in host-endian format,
+	 * set the host_endian output parameter to "1".
+	 *
+	 * Return:
+	 * - 0 on success
+	 * - LIBUSB_ERROR_NOT_FOUND if the device is in unconfigured state
+	 * - another LIBUSB_ERROR code on other failure
+	 */
+	int (*get_active_config_descriptor)(struct libusb_device *device,
+		unsigned char *buffer, size_t len, int *host_endian);
+
+	/* Get a specific configuration descriptor for a device.
+	 *
+	 * The descriptor should be retrieved from memory, NOT via bus I/O to the
+	 * device. This means that you may have to cache it in a private structure
+	 * during get_device_list enumeration.
+	 *
+	 * The requested descriptor is expressed as a zero-based index (i.e. 0
+	 * indicates that we are requesting the first descriptor). The index does
+	 * not (necessarily) equal the bConfigurationValue of the configuration
+	 * being requested.
+	 *
+	 * This function is expected to write len bytes of data into buffer, which
+	 * is guaranteed to be big enough. If you can only do a partial write,
+	 * return an error code.
+	 *
+	 * This function is expected to return the descriptor in bus-endian format
+	 * (LE). If it returns the multi-byte values in host-endian format,
+	 * set the host_endian output parameter to "1".
+	 *
+	 * Return 0 on success or a LIBUSB_ERROR code on failure.
+	 */
+	int (*get_config_descriptor)(struct libusb_device *device,
+		uint8_t config_index, unsigned char *buffer, size_t len,
+		int *host_endian);
+
+	/* Get the bConfigurationValue for the active configuration for a device.
+	 * Optional. This should only be implemented if you can retrieve it from
+	 * cache (don't generate I/O).
+	 *
+	 * If you cannot retrieve this from cache, either do not implement this
+	 * function, or return LIBUSB_ERROR_NOT_SUPPORTED. This will cause
+	 * libusb to retrieve the information through a standard control transfer.
+	 *
+	 * This function must be non-blocking.
+	 * Return:
+	 * - 0 on success
+	 * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it
+	 *   was opened
+	 * - LIBUSB_ERROR_NOT_SUPPORTED if the value cannot be retrieved without
+	 *   blocking
+	 * - another LIBUSB_ERROR code on other failure.
+	 */
+	int (*get_configuration)(struct libusb_device_handle *handle, int *config);
+
+	/* Set the active configuration for a device.
+	 *
+	 * A configuration value of -1 should put the device in unconfigured state.
+	 *
+	 * This function can block.
+	 *
+	 * Return:
+	 * - 0 on success
+	 * - LIBUSB_ERROR_NOT_FOUND if the configuration does not exist
+	 * - LIBUSB_ERROR_BUSY if interfaces are currently claimed (and hence
+	 *   configuration cannot be changed)
+	 * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it
+	 *   was opened
+	 * - another LIBUSB_ERROR code on other failure.
+	 */
+	int (*set_configuration)(struct libusb_device_handle *handle, int config);
+
+	/* Claim an interface. When claimed, the application can then perform
+	 * I/O to an interface's endpoints.
+	 *
+	 * This function should not generate any bus I/O and should not block.
+	 * Interface claiming is a logical operation that simply ensures that
+	 * no other drivers/applications are using the interface, and after
+	 * claiming, no other drivers/applicatiosn can use the interface because
+	 * we now "own" it.
+	 *
+	 * Return:
+	 * - 0 on success
+	 * - LIBUSB_ERROR_NOT_FOUND if the interface does not exist
+	 * - LIBUSB_ERROR_BUSY if the interface is in use by another driver/app
+	 * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it
+	 *   was opened
+	 * - another LIBUSB_ERROR code on other failure
+	 */
+	int (*claim_interface)(struct libusb_device_handle *handle, int interface_number);
+
+	/* Release a previously claimed interface.
+	 *
+	 * This function should also generate a SET_INTERFACE control request,
+	 * resetting the alternate setting of that interface to 0. It's OK for
+	 * this function to block as a result.
+	 *
+	 * You will only ever be asked to release an interface which was
+	 * successfully claimed earlier.
+	 *
+	 * Return:
+	 * - 0 on success
+	 * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it
+	 *   was opened
+	 * - another LIBUSB_ERROR code on other failure
+	 */
+	int (*release_interface)(struct libusb_device_handle *handle, int interface_number);
+
+	/* Set the alternate setting for an interface.
+	 *
+	 * You will only ever be asked to set the alternate setting for an
+	 * interface which was successfully claimed earlier.
+	 *
+	 * It's OK for this function to block.
+	 *
+	 * Return:
+	 * - 0 on success
+	 * - LIBUSB_ERROR_NOT_FOUND if the alternate setting does not exist
+	 * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it
+	 *   was opened
+	 * - another LIBUSB_ERROR code on other failure
+	 */
+	int (*set_interface_altsetting)(struct libusb_device_handle *handle,
+		int interface_number, int altsetting);
+
+	/* Clear a halt/stall condition on an endpoint.
+	 *
+	 * It's OK for this function to block.
+	 *
+	 * Return:
+	 * - 0 on success
+	 * - LIBUSB_ERROR_NOT_FOUND if the endpoint does not exist
+	 * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it
+	 *   was opened
+	 * - another LIBUSB_ERROR code on other failure
+	 */
+	int (*clear_halt)(struct libusb_device_handle *handle,
+		unsigned char endpoint);
+
+	/* Perform a USB port reset to reinitialize a device.
+	 *
+	 * If possible, the handle should still be usable after the reset
+	 * completes, assuming that the device descriptors did not change during
+	 * reset and all previous interface state can be restored.
+	 *
+	 * If something changes, or you cannot easily locate/verify the resetted
+	 * device, return LIBUSB_ERROR_NOT_FOUND. This prompts the application
+	 * to close the old handle and re-enumerate the device.
+	 *
+	 * Return:
+	 * - 0 on success
+	 * - LIBUSB_ERROR_NOT_FOUND if re-enumeration is required, or if the device
+	 *   has been disconnected since it was opened
+	 * - another LIBUSB_ERROR code on other failure
+	 */
+	int (*reset_device)(struct libusb_device_handle *handle);
+
+	/* Determine if a kernel driver is active on an interface. Optional.
+	 *
+	 * The presence of a kernel driver on an interface indicates that any
+	 * calls to claim_interface would fail with the LIBUSB_ERROR_BUSY code.
+	 *
+	 * Return:
+	 * - 0 if no driver is active
+	 * - 1 if a driver is active
+	 * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it
+	 *   was opened
+	 * - another LIBUSB_ERROR code on other failure
+	 */
+	int (*kernel_driver_active)(struct libusb_device_handle *handle,
+		int interface_number);
+
+	/* Detach a kernel driver from an interface. Optional.
+	 *
+	 * After detaching a kernel driver, the interface should be available
+	 * for claim.
+	 *
+	 * Return:
+	 * - 0 on success
+	 * - LIBUSB_ERROR_NOT_FOUND if no kernel driver was active
+	 * - LIBUSB_ERROR_INVALID_PARAM if the interface does not exist
+	 * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it
+	 *   was opened
+	 * - another LIBUSB_ERROR code on other failure
+	 */
+	int (*detach_kernel_driver)(struct libusb_device_handle *handle,
+		int interface_number);
+
+	/* Attach a kernel driver to an interface. Optional.
+	 *
+	 * Reattach a kernel driver to the device.
+	 *
+	 * Return:
+	 * - 0 on success
+	 * - LIBUSB_ERROR_NOT_FOUND if no kernel driver was active
+	 * - LIBUSB_ERROR_INVALID_PARAM if the interface does not exist
+	 * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected since it
+	 *   was opened
+	 * - LIBUSB_ERROR_BUSY if a program or driver has claimed the interface,
+	 *   preventing reattachment
+	 * - another LIBUSB_ERROR code on other failure
+	 */
+	int (*attach_kernel_driver)(struct libusb_device_handle *handle,
+		int interface_number);
+
+	/* Destroy a device. Optional.
+	 *
+	 * This function is called when the last reference to a device is
+	 * destroyed. It should free any resources allocated in the get_device_list
+	 * path.
+	 */
+	void (*destroy_device)(struct libusb_device *dev);
+
+	/* Submit a transfer. Your implementation should take the transfer,
+	 * morph it into whatever form your platform requires, and submit it
+	 * asynchronously.
+	 *
+	 * This function must not block.
+	 *
+	 * Return:
+	 * - 0 on success
+	 * - LIBUSB_ERROR_NO_DEVICE if the device has been disconnected
+	 * - another LIBUSB_ERROR code on other failure
+	 */
+	int (*submit_transfer)(struct usbi_transfer *itransfer);
+
+	/* Cancel a previously submitted transfer.
+	 *
+	 * This function must not block. The transfer cancellation must complete
+	 * later, resulting in a call to usbi_handle_transfer_cancellation()
+	 * from the context of handle_events.
+	 */
+	int (*cancel_transfer)(struct usbi_transfer *itransfer);
+
+	/* Clear a transfer as if it has completed or cancelled, but do not
+	 * report any completion/cancellation to the library. You should free
+	 * all private data from the transfer as if you were just about to report
+	 * completion or cancellation.
+	 *
+	 * This function might seem a bit out of place. It is used when libusb
+	 * detects a disconnected device - it calls this function for all pending
+	 * transfers before reporting completion (with the disconnect code) to
+	 * the user. Maybe we can improve upon this internal interface in future.
+	 */
+	void (*clear_transfer_priv)(struct usbi_transfer *itransfer);
+
+	/* Handle any pending events. This involves monitoring any active
+	 * transfers and processing their completion or cancellation.
+	 *
+	 * The function is passed an array of pollfd structures (size nfds)
+	 * as a result of the poll() system call. The num_ready parameter
+	 * indicates the number of file descriptors that have reported events
+	 * (i.e. the poll() return value). This should be enough information
+	 * for you to determine which actions need to be taken on the currently
+	 * active transfers.
+	 *
+	 * For any cancelled transfers, call usbi_handle_transfer_cancellation().
+	 * For completed transfers, call usbi_handle_transfer_completion().
+	 * For control/bulk/interrupt transfers, populate the "transferred"
+	 * element of the appropriate usbi_transfer structure before calling the
+	 * above functions. For isochronous transfers, populate the status and
+	 * transferred fields of the iso packet descriptors of the transfer.
+	 *
+	 * This function should also be able to detect disconnection of the
+	 * device, reporting that situation with usbi_handle_disconnect().
+	 *
+	 * When processing an event related to a transfer, you probably want to
+	 * take usbi_transfer.lock to prevent races. See the documentation for
+	 * the usbi_transfer structure.
+	 *
+	 * Return 0 on success, or a LIBUSB_ERROR code on failure.
+	 */
+	int (*handle_events)(struct libusb_context *ctx,
+		struct pollfd *fds, nfds_t nfds, int num_ready);
+
+	/* Get time from specified clock. At least two clocks must be implemented
+	   by the backend: USBI_CLOCK_REALTIME, and USBI_CLOCK_MONOTONIC.
+
+	   Description of clocks:
+	     USBI_CLOCK_REALTIME : clock returns time since system epoch.
+	     USBI_CLOCK_MONOTONIC: clock returns time since unspecified start
+	                             time (usually boot).
+	 */
+	int (*clock_gettime)(int clkid, struct timespec *tp);
+
+#ifdef USBI_TIMERFD_AVAILABLE
+	/* clock ID of the clock that should be used for timerfd */
+	clockid_t (*get_timerfd_clockid)(void);
+#endif
+
+	/* Number of bytes to reserve for per-device private backend data.
+	 * This private data area is accessible through the "os_priv" field of
+	 * struct libusb_device. */
+	size_t device_priv_size;
+
+	/* Number of bytes to reserve for per-handle private backend data.
+	 * This private data area is accessible through the "os_priv" field of
+	 * struct libusb_device. */
+	size_t device_handle_priv_size;
+
+	/* Number of bytes to reserve for per-transfer private backend data.
+	 * This private data area is accessible by calling
+	 * usbi_transfer_get_os_priv() on the appropriate usbi_transfer instance.
+	 */
+	size_t transfer_priv_size;
+
+	/* Mumber of additional bytes for os_priv for each iso packet.
+	 * Can your backend use this? */
+	/* FIXME: linux can't use this any more. if other OS's cannot either,
+	 * then remove this */
+	size_t add_iso_packet_size;
+};
+
+extern const struct usbi_os_backend * const usbi_backend;
+
+extern const struct usbi_os_backend linux_usbfs_backend;
+extern const struct usbi_os_backend darwin_backend;
+extern const struct usbi_os_backend windows_backend;
+
+#endif
+
diff --git a/include/libusb-1.0/os/linux_usbfs.c b/include/libusb-1.0/os/linux_usbfs.c
new file mode 100644
index 0000000..a44688d
--- /dev/null
+++ b/include/libusb-1.0/os/linux_usbfs.c
@@ -0,0 +1,2220 @@
+/*
+ * Linux usbfs backend for libusb
+ * Copyright (C) 2007-2009 Daniel Drake <dsd@gentoo.org>
+ * Copyright (c) 2001 Johannes Erdfelt <johannes@erdfelt.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <config.h>
+#include <ctype.h>
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/utsname.h>
+#include <unistd.h>
+
+#include "libusb.h"
+#include "libusbi.h"
+#include "linux_usbfs.h"
+
+/* sysfs vs usbfs:
+ * opening a usbfs node causes the device to be resumed, so we attempt to
+ * avoid this during enumeration.
+ *
+ * sysfs allows us to read the kernel's in-memory copies of device descriptors
+ * and so forth, avoiding the need to open the device:
+ *  - The binary "descriptors" file was added in 2.6.23.
+ *  - The "busnum" file was added in 2.6.22
+ *  - The "devnum" file has been present since pre-2.6.18
+ *  - the "bConfigurationValue" file has been present since pre-2.6.18
+ *
+ * If we have bConfigurationValue, busnum, and devnum, then we can determine
+ * the active configuration without having to open the usbfs node in RDWR mode.
+ * We assume this is the case if we see the busnum file (indicates 2.6.22+).
+ * The busnum file is important as that is the only way we can relate sysfs
+ * devices to usbfs nodes.
+ *
+ * If we also have descriptors, we can obtain the device descriptor and active 
+ * configuration without touching usbfs at all.
+ *
+ * The descriptors file originally only contained the active configuration
+ * descriptor alongside the device descriptor, but all configurations are
+ * included as of Linux 2.6.26.
+ */
+
+/* endianness for multi-byte fields:
+ *
+ * Descriptors exposed by usbfs have the multi-byte fields in the device
+ * descriptor as host endian. Multi-byte fields in the other descriptors are
+ * bus-endian. The kernel documentation says otherwise, but it is wrong.
+ */
+
+static const char *usbfs_path = NULL;
+
+/* Linux 2.6.32 adds support for a bulk continuation URB flag. this basically
+ * allows us to mark URBs as being part of a specific logical transfer when
+ * we submit them to the kernel. then, on any error error except a
+ * cancellation, all URBs within that transfer will be cancelled with the
+ * endpoint is disabled, meaning that no more data can creep in during the
+ * time it takes to cancel the remaining URBs.
+ *
+ * The BULK_CONTINUATION flag must be set on all URBs within a bulk transfer
+ * (in either direction) except the first.
+ * For IN transfers, we must also set SHORT_NOT_OK on all the URBs.
+ * For OUT transfers, SHORT_NOT_OK must not be set. The effective behaviour
+ * (where an OUT transfer does not complete, the rest of the URBs in the
+ * transfer get cancelled) is already in effect, and setting this flag is
+ * disallowed (a kernel with USB debugging enabled will reject such URBs).
+ */
+static int supports_flag_bulk_continuation = -1;
+
+/* clock ID for monotonic clock, as not all clock sources are available on all
+ * systems. appropriate choice made at initialization time. */
+static clockid_t monotonic_clkid = -1;
+
+/* do we have a busnum to relate devices? this also implies that we can read
+ * the active configuration through bConfigurationValue */
+static int sysfs_can_relate_devices = -1;
+
+/* do we have a descriptors file? */
+static int sysfs_has_descriptors = -1;
+
+struct linux_device_priv {
+	char *sysfs_dir;
+	unsigned char *dev_descriptor;
+	unsigned char *config_descriptor;
+};
+
+struct linux_device_handle_priv {
+	int fd;
+};
+
+enum reap_action {
+	NORMAL = 0,
+	/* submission failed after the first URB, so await cancellation/completion
+	 * of all the others */
+	SUBMIT_FAILED,
+
+	/* cancelled by user or timeout */
+	CANCELLED,
+
+	/* completed multi-URB transfer in non-final URB */
+	COMPLETED_EARLY,
+
+	/* one or more urbs encountered a low-level error */
+	ERROR,
+};
+
+struct linux_transfer_priv {
+	union {
+		struct usbfs_urb *urbs;
+		struct usbfs_urb **iso_urbs;
+	};
+
+	enum reap_action reap_action;
+	int num_urbs;
+	unsigned int num_retired;
+	enum libusb_transfer_status reap_status;
+
+	/* next iso packet in user-supplied transfer to be populated */
+	int iso_packet_offset;
+};
+
+static void __get_usbfs_path(struct libusb_device *dev, char *path)
+{
+	snprintf(path, PATH_MAX, "%s/%03d/%03d", usbfs_path, dev->bus_number,
+		dev->device_address);
+}
+
+static struct linux_device_priv *__device_priv(struct libusb_device *dev)
+{
+	return (struct linux_device_priv *) dev->os_priv;
+}
+
+static struct linux_device_handle_priv *__device_handle_priv(
+	struct libusb_device_handle *handle)
+{
+	return (struct linux_device_handle_priv *) handle->os_priv;
+}
+
+static int check_usb_vfs(const char *dirname)
+{
+	DIR *dir;
+	struct dirent *entry;
+	int found = 0;
+
+	dir = opendir(dirname);
+	if (!dir)
+		return 0;
+
+	while ((entry = readdir(dir)) != NULL) {
+		if (entry->d_name[0] == '.')
+			continue;
+
+		/* We assume if we find any files that it must be the right place */
+		found = 1;
+		break;
+	}
+
+	closedir(dir);
+	return found;
+}
+
+static const char *find_usbfs_path(void)
+{
+	const char *path = "/dev/bus/usb";
+	const char *ret = NULL;
+
+	if (check_usb_vfs(path)) {
+		ret = path;
+	} else {
+		path = "/proc/bus/usb";
+		if (check_usb_vfs(path))
+			ret = path;
+	}
+
+	usbi_dbg("found usbfs at %s", ret);
+	return ret;
+}
+
+/* the monotonic clock is not usable on all systems (e.g. embedded ones often
+ * seem to lack it). fall back to REALTIME if we have to. */
+static clockid_t find_monotonic_clock(void)
+{
+	struct timespec ts;
+	int r;
+
+#ifdef CLOCK_MONOTONIC
+	/* Linux 2.6.28 adds CLOCK_MONOTONIC_RAW but we don't use it
+	 * because it's not available through timerfd */
+	r = clock_gettime(CLOCK_MONOTONIC, &ts);
+	if (r == 0)
+		return CLOCK_MONOTONIC;
+	usbi_dbg("monotonic clock doesn't work, errno %d", errno);
+#endif
+
+	return CLOCK_REALTIME;
+}
+
+/* bulk continuation URB flag available from Linux 2.6.32 */
+static int check_flag_bulk_continuation(void)
+{
+	struct utsname uts;
+	int sublevel;
+
+	if (uname(&uts) < 0)
+		return -1;
+	if (strlen(uts.release) < 4)
+		return 0;
+	if (strncmp(uts.release, "2.6.", 4) != 0)
+		return 0;
+
+	sublevel = atoi(uts.release + 4);
+	return sublevel >= 32;
+}
+
+static int op_init(struct libusb_context *ctx)
+{
+	struct stat statbuf;
+	int r;
+
+	usbfs_path = find_usbfs_path();
+	if (!usbfs_path) {
+		usbi_err(ctx, "could not find usbfs");
+		return LIBUSB_ERROR_OTHER;
+	}
+
+	if (monotonic_clkid == -1)
+		monotonic_clkid = find_monotonic_clock();
+
+	if (supports_flag_bulk_continuation == -1) {
+		supports_flag_bulk_continuation = check_flag_bulk_continuation();
+		if (supports_flag_bulk_continuation == -1) {
+			usbi_err(ctx, "error checking for bulk continuation support");
+			return LIBUSB_ERROR_OTHER;
+		}
+	}
+
+	if (supports_flag_bulk_continuation)
+		usbi_dbg("bulk continuation flag supported");
+
+	r = stat(SYSFS_DEVICE_PATH, &statbuf);
+	if (r == 0 && S_ISDIR(statbuf.st_mode)) {
+		usbi_dbg("found usb devices in sysfs");
+	} else {
+		usbi_dbg("sysfs usb info not available");
+		sysfs_has_descriptors = 0;
+		sysfs_can_relate_devices = 0;
+	}
+
+	return 0;
+}
+
+static int usbfs_get_device_descriptor(struct libusb_device *dev,
+	unsigned char *buffer)
+{
+	struct linux_device_priv *priv = __device_priv(dev);
+
+	/* return cached copy */
+	memcpy(buffer, priv->dev_descriptor, DEVICE_DESC_LENGTH);
+	return 0;
+}
+
+static int __open_sysfs_attr(struct libusb_device *dev, const char *attr)
+{
+	struct linux_device_priv *priv = __device_priv(dev);
+	char filename[PATH_MAX];
+	int fd;
+
+	snprintf(filename, PATH_MAX, "%s/%s/%s",
+		SYSFS_DEVICE_PATH, priv->sysfs_dir, attr);
+	fd = open(filename, O_RDONLY);
+	if (fd < 0) {
+		usbi_err(DEVICE_CTX(dev),
+			"open %s failed ret=%d errno=%d", filename, fd, errno);
+		return LIBUSB_ERROR_IO;
+	}
+
+	return fd;
+}
+
+static int sysfs_get_device_descriptor(struct libusb_device *dev,
+	unsigned char *buffer)
+{
+	int fd;
+	ssize_t r;
+
+	/* sysfs provides access to an in-memory copy of the device descriptor,
+	 * so we use that rather than keeping our own copy */
+
+	fd = __open_sysfs_attr(dev, "descriptors");
+	if (fd < 0)
+		return fd;
+
+	r = read(fd, buffer, DEVICE_DESC_LENGTH);;
+	close(fd);
+	if (r < 0) {
+		usbi_err(DEVICE_CTX(dev), "read failed, ret=%d errno=%d", fd, errno);
+		return LIBUSB_ERROR_IO;
+	} else if (r < DEVICE_DESC_LENGTH) {
+		usbi_err(DEVICE_CTX(dev), "short read %d/%d", r, DEVICE_DESC_LENGTH);
+		return LIBUSB_ERROR_IO;
+	}
+
+	return 0;
+}
+
+static int op_get_device_descriptor(struct libusb_device *dev,
+	unsigned char *buffer, int *host_endian)
+{
+	if (sysfs_has_descriptors) {
+		return sysfs_get_device_descriptor(dev, buffer);
+	} else {
+		*host_endian = 1;
+		return usbfs_get_device_descriptor(dev, buffer);
+	}
+}
+
+static int usbfs_get_active_config_descriptor(struct libusb_device *dev,
+	unsigned char *buffer, size_t len)
+{
+	struct linux_device_priv *priv = __device_priv(dev);
+	if (!priv->config_descriptor)
+		return LIBUSB_ERROR_NOT_FOUND; /* device is unconfigured */
+
+	/* retrieve cached copy */
+	memcpy(buffer, priv->config_descriptor, len);
+	return 0;
+}
+
+/* read the bConfigurationValue for a device */
+static int sysfs_get_active_config(struct libusb_device *dev, int *config)
+{
+	char *endptr;
+	char tmp[4] = {0, 0, 0, 0};
+	long num;
+	int fd;
+	size_t r;
+
+	fd = __open_sysfs_attr(dev, "bConfigurationValue");
+	if (fd < 0)
+		return fd;
+
+	r = read(fd, tmp, sizeof(tmp));
+	close(fd);
+	if (r < 0) {
+		usbi_err(DEVICE_CTX(dev), 
+			"read bConfigurationValue failed ret=%d errno=%d", r, errno);
+		return LIBUSB_ERROR_IO;
+	} else if (r == 0) {
+		usbi_err(DEVICE_CTX(dev), "device unconfigured");
+		*config = -1;
+		return 0;
+	}
+
+	if (tmp[sizeof(tmp) - 1] != 0) {
+		usbi_err(DEVICE_CTX(dev), "not null-terminated?");
+		return LIBUSB_ERROR_IO;
+	} else if (tmp[0] == 0) {
+		usbi_err(DEVICE_CTX(dev), "no configuration value?");
+		return LIBUSB_ERROR_IO;
+	}
+
+	num = strtol(tmp, &endptr, 10);
+	if (endptr == tmp) {
+		usbi_err(DEVICE_CTX(dev), "error converting '%s' to integer", tmp);
+		return LIBUSB_ERROR_IO;
+	}
+
+	*config = (int) num;
+	return 0;
+}
+
+/* takes a usbfs/descriptors fd seeked to the start of a configuration, and
+ * seeks to the next one. */
+static int seek_to_next_config(struct libusb_context *ctx, int fd,
+	int host_endian)
+{
+	struct libusb_config_descriptor config;
+	unsigned char tmp[6];
+	off_t off;
+	int r;
+
+	/* read first 6 bytes of descriptor */
+	r = read(fd, tmp, sizeof(tmp));
+	if (r < 0) {
+		usbi_err(ctx, "read failed ret=%d errno=%d", r, errno);
+		return LIBUSB_ERROR_IO;
+	} else if (r < sizeof(tmp)) {
+		usbi_err(ctx, "short descriptor read %d/%d", r, sizeof(tmp));
+		return LIBUSB_ERROR_IO;
+	}
+
+	/* seek forward to end of config */
+	usbi_parse_descriptor(tmp, "bbwbb", &config, host_endian);
+	off = lseek(fd, config.wTotalLength - sizeof(tmp), SEEK_CUR);
+	if (off < 0) {
+		usbi_err(ctx, "seek failed ret=%d errno=%d", off, errno);
+		return LIBUSB_ERROR_IO;
+	}
+
+	return 0;
+}
+
+static int sysfs_get_active_config_descriptor(struct libusb_device *dev,
+	unsigned char *buffer, size_t len)
+{
+	int fd;
+	ssize_t r;
+	off_t off;
+	int to_copy;
+	int config;
+	unsigned char tmp[6];
+
+	r = sysfs_get_active_config(dev, &config);
+	if (r < 0)
+		return r;
+	if (config == -1)
+		return LIBUSB_ERROR_NOT_FOUND;
+
+	usbi_dbg("active configuration %d", config);
+
+	/* sysfs provides access to an in-memory copy of the device descriptor,
+	 * so we use that rather than keeping our own copy */
+
+	fd = __open_sysfs_attr(dev, "descriptors");
+	if (fd < 0)
+		return fd;
+
+	/* device might have been unconfigured since we read bConfigurationValue,
+	 * so first check that there is any config descriptor data at all... */
+	off = lseek(fd, 0, SEEK_END);
+	if (off < 1) {
+		usbi_err(DEVICE_CTX(dev), "end seek failed, ret=%d errno=%d",
+			off, errno);
+		close(fd);
+		return LIBUSB_ERROR_IO;
+	} else if (off == DEVICE_DESC_LENGTH) {
+		close(fd);
+		return LIBUSB_ERROR_NOT_FOUND;
+	}
+
+	off = lseek(fd, DEVICE_DESC_LENGTH, SEEK_SET);
+	if (off < 0) {
+		usbi_err(DEVICE_CTX(dev), "seek failed, ret=%d errno=%d", off, errno);
+		close(fd);
+		return LIBUSB_ERROR_IO;
+	}
+
+	/* unbounded loop: we expect the descriptor to be present under all
+	 * circumstances */
+	while (1) {
+		r = read(fd, tmp, sizeof(tmp));
+		if (r < 0) {
+			usbi_err(DEVICE_CTX(dev), "read failed, ret=%d errno=%d",
+				fd, errno);
+			return LIBUSB_ERROR_IO;
+		} else if (r < sizeof(tmp)) {
+			usbi_err(DEVICE_CTX(dev), "short read %d/%d", r, sizeof(tmp));
+			return LIBUSB_ERROR_IO;
+		}
+
+		/* check bConfigurationValue */
+		if (tmp[5] == config)
+			break;
+
+		/* try the next descriptor */
+		off = lseek(fd, 0 - sizeof(tmp), SEEK_CUR);
+		if (off < 0)
+			return LIBUSB_ERROR_IO;
+
+		r = seek_to_next_config(DEVICE_CTX(dev), fd, 1);
+		if (r < 0)
+			return r;
+	}
+
+	to_copy = (len < sizeof(tmp)) ? len : sizeof(tmp);
+	memcpy(buffer, tmp, to_copy);
+	if (len > sizeof(tmp)) {
+		r = read(fd, buffer + sizeof(tmp), len - sizeof(tmp));
+		if (r < 0) {
+			usbi_err(DEVICE_CTX(dev), "read failed, ret=%d errno=%d",
+				fd, errno);
+			r = LIBUSB_ERROR_IO;
+		} else if (r == 0) {
+			usbi_dbg("device is unconfigured");
+			r = LIBUSB_ERROR_NOT_FOUND;
+		} else if (r < len - sizeof(tmp)) {
+			usbi_err(DEVICE_CTX(dev), "short read %d/%d", r, len);
+			r = LIBUSB_ERROR_IO;
+		}
+	} else {
+		r = 0;
+	}
+
+	close(fd);
+	return r;
+}
+
+static int op_get_active_config_descriptor(struct libusb_device *dev,
+	unsigned char *buffer, size_t len, int *host_endian)
+{
+	if (sysfs_has_descriptors) {
+		return sysfs_get_active_config_descriptor(dev, buffer, len);
+	} else {
+		return usbfs_get_active_config_descriptor(dev, buffer, len);
+	}
+}
+
+/* takes a usbfs fd, attempts to find the requested config and copy a certain
+ * amount of it into an output buffer. */
+static int get_config_descriptor(struct libusb_context *ctx, int fd,
+	uint8_t config_index, unsigned char *buffer, size_t len)
+{
+	off_t off;
+	ssize_t r;
+
+	off = lseek(fd, DEVICE_DESC_LENGTH, SEEK_SET);
+	if (off < 0) {
+		usbi_err(ctx, "seek failed ret=%d errno=%d", off, errno);
+		return LIBUSB_ERROR_IO;
+	}
+
+	/* might need to skip some configuration descriptors to reach the
+	 * requested configuration */
+	while (config_index > 0) {
+		r = seek_to_next_config(ctx, fd, 0);
+		if (r < 0)
+			return r;
+		config_index--;
+	}
+
+	/* read the rest of the descriptor */
+	r = read(fd, buffer, len);
+	if (r < 0) {
+		usbi_err(ctx, "read failed ret=%d errno=%d", r, errno);
+		return LIBUSB_ERROR_IO;
+	} else if (r < len) {
+		usbi_err(ctx, "short output read %d/%d", r, len);
+		return LIBUSB_ERROR_IO;
+	}
+
+	return 0;
+}
+
+static int op_get_config_descriptor(struct libusb_device *dev,
+	uint8_t config_index, unsigned char *buffer, size_t len, int *host_endian)
+{
+	char filename[PATH_MAX];
+	int fd;
+	int r;
+
+	/* always read from usbfs: sysfs only has the active descriptor
+	 * this will involve waking the device up, but oh well! */
+
+	/* FIXME: the above is no longer true, new kernels have all descriptors
+	 * in the descriptors file. but its kinda hard to detect if the kernel
+	 * is sufficiently new. */
+
+	__get_usbfs_path(dev, filename);
+	fd = open(filename, O_RDONLY);
+	if (fd < 0) {
+		usbi_err(DEVICE_CTX(dev),
+			"open '%s' failed, ret=%d errno=%d", filename, fd, errno);
+		return LIBUSB_ERROR_IO;
+	}
+
+	r = get_config_descriptor(DEVICE_CTX(dev), fd, config_index, buffer, len);
+	close(fd);
+	return r;
+}
+
+/* cache the active config descriptor in memory. a value of -1 means that
+ * we aren't sure which one is active, so just assume the first one. 
+ * only for usbfs. */
+static int cache_active_config(struct libusb_device *dev, int fd,
+	int active_config)
+{
+	struct linux_device_priv *priv = __device_priv(dev);
+	struct libusb_config_descriptor config;
+	unsigned char tmp[8];
+	unsigned char *buf;
+	int idx;
+	int r;
+
+	if (active_config == -1) {
+		idx = 0;
+	} else {
+		r = usbi_get_config_index_by_value(dev, active_config, &idx);
+		if (r < 0)
+			return r;
+		if (idx == -1)
+			return LIBUSB_ERROR_NOT_FOUND;
+	}
+
+	r = get_config_descriptor(DEVICE_CTX(dev), fd, idx, tmp, sizeof(tmp));
+	if (r < 0) {
+		usbi_err(DEVICE_CTX(dev), "first read error %d", r);
+		return r;
+	}
+
+	usbi_parse_descriptor(tmp, "bbw", &config, 0);
+	buf = malloc(config.wTotalLength);
+	if (!buf)
+		return LIBUSB_ERROR_NO_MEM;
+
+	r = get_config_descriptor(DEVICE_CTX(dev), fd, idx, buf,
+		config.wTotalLength);
+	if (r < 0) {
+		free(buf);
+		return r;
+	}
+
+	if (priv->config_descriptor)
+		free(priv->config_descriptor);
+	priv->config_descriptor = buf;
+	return 0;
+}
+
+/* send a control message to retrieve active configuration */
+static int usbfs_get_active_config(struct libusb_device *dev, int fd)
+{
+	unsigned char active_config = 0;
+	int r;
+
+	struct usbfs_ctrltransfer ctrl = {
+		.bmRequestType = LIBUSB_ENDPOINT_IN,
+		.bRequest = LIBUSB_REQUEST_GET_CONFIGURATION,
+		.wValue = 0,
+		.wIndex = 0,
+		.wLength = 1,
+		.timeout = 1000,
+		.data = &active_config
+	};
+
+	r = ioctl(fd, IOCTL_USBFS_CONTROL, &ctrl);
+	if (r < 0) {
+		if (errno == ENODEV)
+			return LIBUSB_ERROR_NO_DEVICE;
+
+		/* we hit this error path frequently with buggy devices :( */
+		usbi_warn(DEVICE_CTX(dev),
+			"get_configuration failed ret=%d errno=%d", r, errno);
+		return LIBUSB_ERROR_IO;
+	}
+
+	return active_config;
+}
+
+static int initialize_device(struct libusb_device *dev, uint8_t busnum,
+	uint8_t devaddr, const char *sysfs_dir)
+{
+	struct linux_device_priv *priv = __device_priv(dev);
+	unsigned char *dev_buf;
+	char path[PATH_MAX];
+	int fd;
+	int active_config = 0;
+	int device_configured = 1;
+	ssize_t r;
+
+	dev->bus_number = busnum;
+	dev->device_address = devaddr;
+
+	if (sysfs_dir) {
+		priv->sysfs_dir = malloc(strlen(sysfs_dir) + 1);
+		if (!priv->sysfs_dir)
+			return LIBUSB_ERROR_NO_MEM;
+		strcpy(priv->sysfs_dir, sysfs_dir);
+	}
+
+	if (sysfs_has_descriptors)
+		return 0;
+
+	/* cache device descriptor in memory so that we can retrieve it later
+	 * without waking the device up (op_get_device_descriptor) */
+
+	priv->dev_descriptor = NULL;
+	priv->config_descriptor = NULL;
+
+	if (sysfs_can_relate_devices) {
+		int tmp = sysfs_get_active_config(dev, &active_config);
+		if (tmp < 0)
+			return tmp;
+		if (active_config == -1)
+			device_configured = 0;
+	}
+
+	__get_usbfs_path(dev, path);
+	fd = open(path, O_RDWR);
+	if (fd < 0 && errno == EACCES) {
+		fd = open(path, O_RDONLY);
+		/* if we only have read-only access to the device, we cannot
+		 * send a control message to determine the active config. just
+		 * assume the first one is active. */
+		active_config = -1;
+	}
+
+	if (fd < 0) {
+		usbi_err(DEVICE_CTX(dev), "open failed, ret=%d errno=%d", fd, errno);
+		return LIBUSB_ERROR_IO;
+	}
+
+	if (!sysfs_can_relate_devices) {
+		if (active_config == -1) {
+			/* if we only have read-only access to the device, we cannot
+			 * send a control message to determine the active config. just
+			 * assume the first one is active. */
+			usbi_warn(DEVICE_CTX(dev), "access to %s is read-only; cannot "
+				"determine active configuration descriptor", path);
+		} else {
+			active_config = usbfs_get_active_config(dev, fd);
+			if (active_config == LIBUSB_ERROR_IO) {
+				/* buggy devices sometimes fail to report their active config.
+				 * assume unconfigured and continue the probing */
+				usbi_warn(DEVICE_CTX(dev), "couldn't query active "
+					"configuration, assumung unconfigured");
+				device_configured = 0;
+			} else if (active_config < 0) {
+				close(fd);
+				return active_config;
+			} else if (active_config == 0) {
+				/* some buggy devices have a configuration 0, but we're
+				 * reaching into the corner of a corner case here, so let's
+				 * not support buggy devices in these circumstances.
+				 * stick to the specs: a configuration value of 0 means
+				 * unconfigured. */
+				usbi_dbg("active cfg 0? assuming unconfigured device");
+				device_configured = 0;
+			}
+		}
+	}
+
+	dev_buf = malloc(DEVICE_DESC_LENGTH);
+	if (!dev_buf) {
+		close(fd);
+		return LIBUSB_ERROR_NO_MEM;
+	}
+
+	r = read(fd, dev_buf, DEVICE_DESC_LENGTH);
+	if (r < 0) {
+		usbi_err(DEVICE_CTX(dev),
+			"read descriptor failed ret=%d errno=%d", fd, errno);
+		free(dev_buf);
+		close(fd);
+		return LIBUSB_ERROR_IO;
+	} else if (r < DEVICE_DESC_LENGTH) {
+		usbi_err(DEVICE_CTX(dev), "short descriptor read (%d)", r);
+		free(dev_buf);
+		close(fd);
+		return LIBUSB_ERROR_IO;
+	}
+
+	/* bit of a hack: set num_configurations now because cache_active_config()
+	 * calls usbi_get_config_index_by_value() which uses it */
+	dev->num_configurations = dev_buf[DEVICE_DESC_LENGTH - 1];
+
+	if (device_configured) {
+		r = cache_active_config(dev, fd, active_config);
+		if (r < 0) {
+			close(fd);
+			free(dev_buf);
+			return r;
+		}
+	}
+
+	close(fd);
+	priv->dev_descriptor = dev_buf;
+	return 0;
+}
+
+static int enumerate_device(struct libusb_context *ctx,
+	struct discovered_devs **_discdevs, uint8_t busnum, uint8_t devaddr,
+	const char *sysfs_dir)
+{
+	struct discovered_devs *discdevs;
+	unsigned long session_id;
+	int need_unref = 0;
+	struct libusb_device *dev;
+	int r = 0;
+
+	/* FIXME: session ID is not guaranteed unique as addresses can wrap and
+	 * will be reused. instead we should add a simple sysfs attribute with
+	 * a session ID. */
+	session_id = busnum << 8 | devaddr;
+	usbi_dbg("busnum %d devaddr %d session_id %ld", busnum, devaddr,
+		session_id);
+
+	dev = usbi_get_device_by_session_id(ctx, session_id);
+	if (dev) {
+		usbi_dbg("using existing device for %d/%d (session %ld)",
+			busnum, devaddr, session_id);
+	} else {
+		usbi_dbg("allocating new device for %d/%d (session %ld)",
+			busnum, devaddr, session_id);
+		dev = usbi_alloc_device(ctx, session_id);
+		if (!dev)
+			return LIBUSB_ERROR_NO_MEM;
+		need_unref = 1;
+		r = initialize_device(dev, busnum, devaddr, sysfs_dir);
+		if (r < 0)
+			goto out;
+		r = usbi_sanitize_device(dev);
+		if (r < 0)
+			goto out;
+	}
+
+	discdevs = discovered_devs_append(*_discdevs, dev);
+	if (!discdevs)
+		r = LIBUSB_ERROR_NO_MEM;
+	else
+		*_discdevs = discdevs;
+
+out:
+	if (need_unref)
+		libusb_unref_device(dev);
+	return r;
+}
+
+/* open a bus directory and adds all discovered devices to discdevs. on
+ * failure (non-zero return) the pre-existing discdevs should be destroyed
+ * (and devices freed). on success, the new discdevs pointer should be used
+ * as it may have been moved. */
+static int usbfs_scan_busdir(struct libusb_context *ctx,
+	struct discovered_devs **_discdevs, uint8_t busnum)
+{
+	DIR *dir;
+	char dirpath[PATH_MAX];
+	struct dirent *entry;
+	struct discovered_devs *discdevs = *_discdevs;
+	int r = 0;
+
+	snprintf(dirpath, PATH_MAX, "%s/%03d", usbfs_path, busnum);
+	usbi_dbg("%s", dirpath);
+	dir = opendir(dirpath);
+	if (!dir) {
+		usbi_err(ctx, "opendir '%s' failed, errno=%d", dirpath, errno);
+		/* FIXME: should handle valid race conditions like hub unplugged
+		 * during directory iteration - this is not an error */
+		return LIBUSB_ERROR_IO;
+	}
+
+	while ((entry = readdir(dir))) {
+		int devaddr;
+
+		if (entry->d_name[0] == '.')
+			continue;
+
+		devaddr = atoi(entry->d_name);
+		if (devaddr == 0) {
+			usbi_dbg("unknown dir entry %s", entry->d_name);
+			continue;
+		}
+
+		r = enumerate_device(ctx, &discdevs, busnum, (uint8_t) devaddr, NULL);
+		if (r < 0)
+			goto out;
+	}
+
+	*_discdevs = discdevs;
+out:
+	closedir(dir);
+	return r;
+}
+
+static int usbfs_get_device_list(struct libusb_context *ctx,
+	struct discovered_devs **_discdevs)
+{
+	struct dirent *entry;
+	DIR *buses = opendir(usbfs_path);
+	struct discovered_devs *discdevs = *_discdevs;
+	int r = 0;
+
+	if (!buses) {
+		usbi_err(ctx, "opendir buses failed errno=%d", errno);
+		return LIBUSB_ERROR_IO;
+	}
+
+	while ((entry = readdir(buses))) {
+		struct discovered_devs *discdevs_new = discdevs;
+		int busnum;
+
+		if (entry->d_name[0] == '.')
+			continue;
+
+		busnum = atoi(entry->d_name);
+		if (busnum == 0) {
+			usbi_dbg("unknown dir entry %s", entry->d_name);
+			continue;
+		}
+
+		r = usbfs_scan_busdir(ctx, &discdevs_new, busnum);
+		if (r < 0)
+			goto out;
+		discdevs = discdevs_new;
+	}
+
+out:
+	closedir(buses);
+	*_discdevs = discdevs;
+	return r;
+
+}
+
+static int sysfs_scan_device(struct libusb_context *ctx,
+	struct discovered_devs **_discdevs, const char *devname,
+	int *usbfs_fallback)
+{
+	int r;
+	FILE *fd;
+	char filename[PATH_MAX];
+	int busnum;
+	int devaddr;
+
+	usbi_dbg("scan %s", devname);
+
+	/* determine descriptors presence ahead of time, we need to know this
+	 * when we reach initialize_device */
+	if (sysfs_has_descriptors == -1) {
+		struct stat statbuf;
+
+		snprintf(filename, PATH_MAX, "%s/%s/descriptors", SYSFS_DEVICE_PATH,
+			devname);
+		r = stat(filename, &statbuf);
+		if (r == 0 && S_ISREG(statbuf.st_mode)) {
+			usbi_dbg("sysfs descriptors available");
+			sysfs_has_descriptors = 1;
+		} else {
+			usbi_dbg("sysfs descriptors not available");
+			sysfs_has_descriptors = 0;
+		}
+	}
+
+	snprintf(filename, PATH_MAX, "%s/%s/busnum", SYSFS_DEVICE_PATH, devname);
+	fd = fopen(filename, "r");
+	if (!fd) {
+		if (errno == ENOENT) {
+			usbi_dbg("busnum not found, cannot relate sysfs to usbfs, "
+				"falling back on pure usbfs");
+			sysfs_can_relate_devices = 0;
+			*usbfs_fallback = 1;
+			return LIBUSB_ERROR_OTHER;
+		}
+		usbi_err(ctx, "open busnum failed, errno=%d", errno);
+		return LIBUSB_ERROR_IO;
+	}
+
+	sysfs_can_relate_devices = 1;
+
+	r = fscanf(fd, "%d", &busnum);
+	fclose(fd);
+	if (r != 1) {
+		usbi_err(ctx, "fscanf busnum returned %d, errno=%d", r, errno);
+		return LIBUSB_ERROR_IO;
+	}
+
+	snprintf(filename, PATH_MAX, "%s/%s/devnum", SYSFS_DEVICE_PATH, devname);
+	fd = fopen(filename, "r");
+	if (!fd) {
+		usbi_err(ctx, "open devnum failed, errno=%d", errno);
+		return LIBUSB_ERROR_IO;
+	}
+
+	r = fscanf(fd, "%d", &devaddr);
+	fclose(fd);
+	if (r != 1) {
+		usbi_err(ctx, "fscanf devnum returned %d, errno=%d", r, errno);
+		return LIBUSB_ERROR_IO;
+	}
+
+	usbi_dbg("bus=%d dev=%d", busnum, devaddr);
+	if (busnum > 255 || devaddr > 255)
+		return LIBUSB_ERROR_INVALID_PARAM;
+
+	return enumerate_device(ctx, _discdevs, busnum & 0xff, devaddr & 0xff,
+		devname);
+}
+
+static int sysfs_get_device_list(struct libusb_context *ctx,
+	struct discovered_devs **_discdevs, int *usbfs_fallback)
+{
+	struct discovered_devs *discdevs = *_discdevs;
+	DIR *devices = opendir(SYSFS_DEVICE_PATH);
+	struct dirent *entry;
+	int r = 0;
+
+	if (!devices) {
+		usbi_err(ctx, "opendir devices failed errno=%d", errno);
+		return LIBUSB_ERROR_IO;
+	}
+
+	while ((entry = readdir(devices))) {
+		struct discovered_devs *discdevs_new = discdevs;
+
+		if ((!isdigit(entry->d_name[0]) && strncmp(entry->d_name, "usb", 3))
+				|| strchr(entry->d_name, ':'))
+			continue;
+
+		r = sysfs_scan_device(ctx, &discdevs_new, entry->d_name,
+			usbfs_fallback);
+		if (r < 0)
+			goto out;
+		discdevs = discdevs_new;
+	}	
+
+out:
+	closedir(devices);
+	*_discdevs = discdevs;
+	return r;
+}
+
+static int op_get_device_list(struct libusb_context *ctx,
+	struct discovered_devs **_discdevs)
+{
+	/* we can retrieve device list and descriptors from sysfs or usbfs.
+	 * sysfs is preferable, because if we use usbfs we end up resuming
+	 * any autosuspended USB devices. however, sysfs is not available
+	 * everywhere, so we need a usbfs fallback too.
+	 *
+	 * as described in the "sysfs vs usbfs" comment, sometimes we have
+	 * sysfs but not enough information to relate sysfs devices to usbfs
+	 * nodes. the usbfs_fallback variable is used to indicate that we should
+	 * fall back on usbfs.
+	 */
+	if (sysfs_can_relate_devices != 0) {
+		int usbfs_fallback = 0;
+		int r = sysfs_get_device_list(ctx, _discdevs, &usbfs_fallback);
+		if (!usbfs_fallback)
+			return r;
+	}
+
+	return usbfs_get_device_list(ctx, _discdevs);
+}
+
+static int op_open(struct libusb_device_handle *handle)
+{
+	struct linux_device_handle_priv *hpriv = __device_handle_priv(handle);
+	char filename[PATH_MAX];
+
+	__get_usbfs_path(handle->dev, filename);
+	hpriv->fd = open(filename, O_RDWR);
+	if (hpriv->fd < 0) {
+		if (errno == EACCES) {
+			usbi_err(HANDLE_CTX(handle), "libusb couldn't open USB device %s: "
+				"Permission denied.", filename);
+			usbi_err(HANDLE_CTX(handle),
+				"libusb requires write access to USB device nodes.");
+			return LIBUSB_ERROR_ACCESS;
+		} else if (errno == ENOENT) {
+			return LIBUSB_ERROR_NO_DEVICE;
+		} else {
+			usbi_err(HANDLE_CTX(handle),
+				"open failed, code %d errno %d", hpriv->fd, errno);
+			return LIBUSB_ERROR_IO;
+		}
+	}
+
+	return usbi_add_pollfd(HANDLE_CTX(handle), hpriv->fd, POLLOUT);
+}
+
+static void op_close(struct libusb_device_handle *dev_handle)
+{
+	int fd = __device_handle_priv(dev_handle)->fd;
+	usbi_remove_pollfd(HANDLE_CTX(dev_handle), fd);
+	close(fd);
+}
+
+static int op_get_configuration(struct libusb_device_handle *handle,
+	int *config)
+{
+	int r;
+	if (sysfs_can_relate_devices != 1)
+		return LIBUSB_ERROR_NOT_SUPPORTED;
+
+	r = sysfs_get_active_config(handle->dev, config);
+	if (*config == -1)
+		*config = 0;
+
+	return 0;
+}
+
+static int op_set_configuration(struct libusb_device_handle *handle, int config)
+{
+	struct linux_device_priv *priv = __device_priv(handle->dev);
+	int fd = __device_handle_priv(handle)->fd;
+	int r = ioctl(fd, IOCTL_USBFS_SETCONFIG, &config);
+	if (r) {
+		if (errno == EINVAL)
+			return LIBUSB_ERROR_NOT_FOUND;
+		else if (errno == EBUSY)
+			return LIBUSB_ERROR_BUSY;
+		else if (errno == ENODEV)
+			return LIBUSB_ERROR_NO_DEVICE;
+
+		usbi_err(HANDLE_CTX(handle), "failed, error %d errno %d", r, errno);
+		return LIBUSB_ERROR_OTHER;
+	}
+
+	if (!sysfs_has_descriptors) {
+		/* update our cached active config descriptor */
+		if (config == -1) {
+			if (priv->config_descriptor) {
+				free(priv->config_descriptor);
+				priv->config_descriptor = NULL;
+			}
+		} else {
+			r = cache_active_config(handle->dev, fd, config);
+			if (r < 0)
+				usbi_warn(HANDLE_CTX(handle),
+					"failed to update cached config descriptor, error %d", r);
+		}
+	}
+
+	return 0;
+}
+
+static int op_claim_interface(struct libusb_device_handle *handle, int iface)
+{
+	int fd = __device_handle_priv(handle)->fd;
+	int r = ioctl(fd, IOCTL_USBFS_CLAIMINTF, &iface);
+	if (r) {
+		if (errno == ENOENT)
+			return LIBUSB_ERROR_NOT_FOUND;
+		else if (errno == EBUSY)
+			return LIBUSB_ERROR_BUSY;
+		else if (errno == ENODEV)
+			return LIBUSB_ERROR_NO_DEVICE;
+
+		usbi_err(HANDLE_CTX(handle),
+			"claim interface failed, error %d errno %d", r, errno);
+		return LIBUSB_ERROR_OTHER;
+	}
+	return 0;
+}
+
+static int op_release_interface(struct libusb_device_handle *handle, int iface)
+{
+	int fd = __device_handle_priv(handle)->fd;
+	int r = ioctl(fd, IOCTL_USBFS_RELEASEINTF, &iface);
+	if (r) {
+		if (errno == ENODEV)
+			return LIBUSB_ERROR_NO_DEVICE;
+
+		usbi_err(HANDLE_CTX(handle),
+			"release interface failed, error %d errno %d", r, errno);
+		return LIBUSB_ERROR_OTHER;
+	}
+	return 0;
+}
+
+static int op_set_interface(struct libusb_device_handle *handle, int iface,
+	int altsetting)
+{
+	int fd = __device_handle_priv(handle)->fd;
+	struct usbfs_setinterface setintf;
+	int r;
+
+	setintf.interface = iface;
+	setintf.altsetting = altsetting;
+	r = ioctl(fd, IOCTL_USBFS_SETINTF, &setintf);
+	if (r) {
+		if (errno == EINVAL)
+			return LIBUSB_ERROR_NOT_FOUND;
+		else if (errno == ENODEV)
+			return LIBUSB_ERROR_NO_DEVICE;
+
+		usbi_err(HANDLE_CTX(handle),
+			"setintf failed error %d errno %d", r, errno);
+		return LIBUSB_ERROR_OTHER;
+	}
+
+	return 0;
+}
+
+static int op_clear_halt(struct libusb_device_handle *handle,
+	unsigned char endpoint)
+{
+	int fd = __device_handle_priv(handle)->fd;
+	unsigned int _endpoint = endpoint;
+	int r = ioctl(fd, IOCTL_USBFS_CLEAR_HALT, &_endpoint);
+	if (r) {
+		if (errno == ENOENT)
+			return LIBUSB_ERROR_NOT_FOUND;
+		else if (errno == ENODEV)
+			return LIBUSB_ERROR_NO_DEVICE;
+
+		usbi_err(HANDLE_CTX(handle),
+			"clear_halt failed error %d errno %d", r, errno);
+		return LIBUSB_ERROR_OTHER;
+	}
+
+	return 0;
+}
+
+static int op_reset_device(struct libusb_device_handle *handle)
+{
+	int fd = __device_handle_priv(handle)->fd;
+	int r = ioctl(fd, IOCTL_USBFS_RESET, NULL);
+	if (r) {
+		if (errno == ENODEV)
+			return LIBUSB_ERROR_NOT_FOUND;
+
+		usbi_err(HANDLE_CTX(handle),
+			"reset failed error %d errno %d", r, errno);
+		return LIBUSB_ERROR_OTHER;
+	}
+
+	return 0;
+}
+
+static int op_kernel_driver_active(struct libusb_device_handle *handle,
+	int interface)
+{
+	int fd = __device_handle_priv(handle)->fd;
+	struct usbfs_getdriver getdrv;
+	int r;
+
+	getdrv.interface = interface;
+	r = ioctl(fd, IOCTL_USBFS_GETDRIVER, &getdrv);
+	if (r) {
+		if (errno == ENODATA)
+			return 0;
+		else if (errno == ENODEV)
+			return LIBUSB_ERROR_NO_DEVICE;
+
+		usbi_err(HANDLE_CTX(handle),
+			"get driver failed error %d errno %d", r, errno);
+		return LIBUSB_ERROR_OTHER;
+	}
+
+	return 1;
+}
+
+static int op_detach_kernel_driver(struct libusb_device_handle *handle,
+	int interface)
+{
+	int fd = __device_handle_priv(handle)->fd;
+	struct usbfs_ioctl command;
+	int r;
+
+	command.ifno = interface;
+	command.ioctl_code = IOCTL_USBFS_DISCONNECT;
+	command.data = NULL;
+
+	r = ioctl(fd, IOCTL_USBFS_IOCTL, &command);
+	if (r) {
+		if (errno == ENODATA)
+			return LIBUSB_ERROR_NOT_FOUND;
+		else if (errno == EINVAL)
+			return LIBUSB_ERROR_INVALID_PARAM;
+		else if (errno == ENODEV)
+			return LIBUSB_ERROR_NO_DEVICE;
+
+		usbi_err(HANDLE_CTX(handle),
+			"detach failed error %d errno %d", r, errno);
+		return LIBUSB_ERROR_OTHER;
+	}
+
+	return 0;
+}
+
+static int op_attach_kernel_driver(struct libusb_device_handle *handle,
+	int interface)
+{
+	int fd = __device_handle_priv(handle)->fd;
+	struct usbfs_ioctl command;
+	int r;
+
+	command.ifno = interface;
+	command.ioctl_code = IOCTL_USBFS_CONNECT;
+	command.data = NULL;
+
+	r = ioctl(fd, IOCTL_USBFS_IOCTL, &command);
+	if (r < 0) {
+		if (errno == ENODATA)
+			return LIBUSB_ERROR_NOT_FOUND;
+		else if (errno == EINVAL)
+			return LIBUSB_ERROR_INVALID_PARAM;
+		else if (errno == ENODEV)
+			return LIBUSB_ERROR_NO_DEVICE;
+		else if (errno == EBUSY)
+			return LIBUSB_ERROR_BUSY;
+
+		usbi_err(HANDLE_CTX(handle),
+			"attach failed error %d errno %d", r, errno);
+		return LIBUSB_ERROR_OTHER;
+	} else if (r == 0) {
+		return LIBUSB_ERROR_NOT_FOUND;
+	}
+
+	return 0;
+}
+
+static void op_destroy_device(struct libusb_device *dev)
+{
+	struct linux_device_priv *priv = __device_priv(dev);
+	if (!sysfs_has_descriptors) {
+		if (priv->dev_descriptor)
+			free(priv->dev_descriptor);
+		if (priv->config_descriptor)
+			free(priv->config_descriptor);
+	}
+	if (priv->sysfs_dir)
+		free(priv->sysfs_dir);
+}
+
+static void free_iso_urbs(struct linux_transfer_priv *tpriv)
+{
+	int i;
+	for (i = 0; i < tpriv->num_urbs; i++) {
+		struct usbfs_urb *urb = tpriv->iso_urbs[i];
+		if (!urb)
+			break;
+		free(urb);
+	}
+
+	free(tpriv->iso_urbs);
+	tpriv->iso_urbs = NULL;
+}
+
+static int submit_bulk_transfer(struct usbi_transfer *itransfer,
+	unsigned char urb_type)
+{
+	struct libusb_transfer *transfer =
+		__USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct linux_transfer_priv *tpriv = usbi_transfer_get_os_priv(itransfer);
+	struct linux_device_handle_priv *dpriv =
+		__device_handle_priv(transfer->dev_handle);
+	struct usbfs_urb *urbs;
+	int is_out = (transfer->endpoint & LIBUSB_ENDPOINT_DIR_MASK)
+		== LIBUSB_ENDPOINT_OUT;
+	int r;
+	int i;
+	size_t alloc_size;
+
+	if (tpriv->urbs)
+		return LIBUSB_ERROR_BUSY;
+
+	/* usbfs places a 16kb limit on bulk URBs. we divide up larger requests
+	 * into smaller units to meet such restriction, then fire off all the
+	 * units at once. it would be simpler if we just fired one unit at a time,
+	 * but there is a big performance gain through doing it this way. */
+	int num_urbs = transfer->length / MAX_BULK_BUFFER_LENGTH;
+	int last_urb_partial = 0;
+
+	if (transfer->length == 0) {
+		num_urbs = 1;
+	} else if ((transfer->length % MAX_BULK_BUFFER_LENGTH) > 0) {
+		last_urb_partial = 1;
+		num_urbs++;
+	}
+	usbi_dbg("need %d urbs for new transfer with length %d", num_urbs,
+		transfer->length);
+	alloc_size = num_urbs * sizeof(struct usbfs_urb);
+	urbs = malloc(alloc_size);
+	if (!urbs)
+		return LIBUSB_ERROR_NO_MEM;
+	memset(urbs, 0, alloc_size);
+	tpriv->urbs = urbs;
+	tpriv->num_urbs = num_urbs;
+	tpriv->num_retired = 0;
+	tpriv->reap_action = NORMAL;
+	tpriv->reap_status = LIBUSB_TRANSFER_COMPLETED;
+
+	for (i = 0; i < num_urbs; i++) {
+		struct usbfs_urb *urb = &urbs[i];
+		urb->usercontext = itransfer;
+		urb->type = urb_type;
+		urb->endpoint = transfer->endpoint;
+		urb->buffer = transfer->buffer + (i * MAX_BULK_BUFFER_LENGTH);
+		if (supports_flag_bulk_continuation && !is_out)
+			urb->flags = USBFS_URB_SHORT_NOT_OK;
+		if (i == num_urbs - 1 && last_urb_partial)
+			urb->buffer_length = transfer->length % MAX_BULK_BUFFER_LENGTH;
+		else if (transfer->length == 0)
+			urb->buffer_length = 0;
+		else
+			urb->buffer_length = MAX_BULK_BUFFER_LENGTH;
+
+		if (i > 0 && supports_flag_bulk_continuation)
+			urb->flags |= USBFS_URB_BULK_CONTINUATION;
+
+		r = ioctl(dpriv->fd, IOCTL_USBFS_SUBMITURB, urb);
+		if (r < 0) {
+			int j;
+
+			if (errno == ENODEV) {
+				r = LIBUSB_ERROR_NO_DEVICE;
+			} else {
+				usbi_err(TRANSFER_CTX(transfer),
+					"submiturb failed error %d errno=%d", r, errno);
+				r = LIBUSB_ERROR_IO;
+			}
+	
+			/* if the first URB submission fails, we can simply free up and
+			 * return failure immediately. */
+			if (i == 0) {
+				usbi_dbg("first URB failed, easy peasy");
+				free(urbs);
+				tpriv->urbs = NULL;
+				return r;
+			}
+
+			/* if it's not the first URB that failed, the situation is a bit
+			 * tricky. we may need to discard all previous URBs. there are
+			 * complications:
+			 *  - discarding is asynchronous - discarded urbs will be reaped
+			 *    later. the user must not have freed the transfer when the
+			 *    discarded URBs are reaped, otherwise libusb will be using
+			 *    freed memory.
+			 *  - the earlier URBs may have completed successfully and we do
+			 *    not want to throw away any data.
+			 *  - this URB failing may be no error; EREMOTEIO means that
+			 *    this transfer simply didn't need all the URBs we submitted
+			 * so, we report that the transfer was submitted successfully and
+			 * in case of error we discard all previous URBs. later when
+			 * the final reap completes we can report error to the user,
+			 * or success if an earlier URB was completed successfully.
+			 */
+			tpriv->reap_action = EREMOTEIO == errno ? COMPLETED_EARLY : SUBMIT_FAILED;
+
+			/* The URBs we haven't submitted yet we count as already
+			 * retired. */
+			tpriv->num_retired += num_urbs - i;
+
+			/* If we completed short then don't try to discard. */
+			if (COMPLETED_EARLY == tpriv->reap_action)
+				return 0;
+
+			for (j = 0; j < i; j++) {
+				int tmp = ioctl(dpriv->fd, IOCTL_USBFS_DISCARDURB, &urbs[j]);
+				if (tmp && errno != EINVAL)
+					usbi_warn(TRANSFER_CTX(transfer),
+						"unrecognised discard errno %d", errno);
+			}
+
+			usbi_dbg("reporting successful submission but waiting for %d "
+				"discards before reporting error", i);
+			return 0;
+		}
+	}
+
+	return 0;
+}
+
+static int submit_iso_transfer(struct usbi_transfer *itransfer)
+{
+	struct libusb_transfer *transfer =
+		__USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct linux_transfer_priv *tpriv = usbi_transfer_get_os_priv(itransfer);
+	struct linux_device_handle_priv *dpriv =
+		__device_handle_priv(transfer->dev_handle);
+	struct usbfs_urb **urbs;
+	size_t alloc_size;
+	int num_packets = transfer->num_iso_packets;
+	int i;
+	int this_urb_len = 0;
+	int num_urbs = 1;
+	int packet_offset = 0;
+	unsigned int packet_len;
+	unsigned char *urb_buffer = transfer->buffer;
+
+	if (tpriv->iso_urbs)
+		return LIBUSB_ERROR_BUSY;
+
+	/* usbfs places a 32kb limit on iso URBs. we divide up larger requests
+	 * into smaller units to meet such restriction, then fire off all the
+	 * units at once. it would be simpler if we just fired one unit at a time,
+	 * but there is a big performance gain through doing it this way. */
+
+	/* calculate how many URBs we need */
+	for (i = 0; i < num_packets; i++) {
+		int space_remaining = MAX_ISO_BUFFER_LENGTH - this_urb_len;
+		packet_len = transfer->iso_packet_desc[i].length;
+
+		if (packet_len > space_remaining) {
+			num_urbs++;
+			this_urb_len = packet_len;
+		} else {
+			this_urb_len += packet_len;
+		}
+	}
+	usbi_dbg("need %d 32k URBs for transfer", num_urbs);
+
+	alloc_size = num_urbs * sizeof(*urbs);
+	urbs = malloc(alloc_size);
+	if (!urbs)
+		return LIBUSB_ERROR_NO_MEM;
+	memset(urbs, 0, alloc_size);
+
+	tpriv->iso_urbs = urbs;
+	tpriv->num_urbs = num_urbs;
+	tpriv->num_retired = 0;
+	tpriv->reap_action = NORMAL;
+	tpriv->iso_packet_offset = 0;
+
+	/* allocate + initialize each URB with the correct number of packets */
+	for (i = 0; i < num_urbs; i++) {
+		struct usbfs_urb *urb;
+		int space_remaining_in_urb = MAX_ISO_BUFFER_LENGTH;
+		int urb_packet_offset = 0;
+		unsigned char *urb_buffer_orig = urb_buffer;
+		int j;
+		int k;
+
+		/* swallow up all the packets we can fit into this URB */
+		while (packet_offset < transfer->num_iso_packets) {
+			packet_len = transfer->iso_packet_desc[packet_offset].length;
+			if (packet_len <= space_remaining_in_urb) {
+				/* throw it in */
+				urb_packet_offset++;
+				packet_offset++;
+				space_remaining_in_urb -= packet_len;
+				urb_buffer += packet_len;
+			} else {
+				/* it can't fit, save it for the next URB */
+				break;
+			}
+		}
+
+		alloc_size = sizeof(*urb)
+			+ (urb_packet_offset * sizeof(struct usbfs_iso_packet_desc));
+		urb = malloc(alloc_size);
+		if (!urb) {
+			free_iso_urbs(tpriv);
+			return LIBUSB_ERROR_NO_MEM;
+		}
+		memset(urb, 0, alloc_size);
+		urbs[i] = urb;
+
+		/* populate packet lengths */
+		for (j = 0, k = packet_offset - urb_packet_offset;
+				k < packet_offset; k++, j++) {
+			packet_len = transfer->iso_packet_desc[k].length;
+			urb->iso_frame_desc[j].length = packet_len;
+		}
+
+		urb->usercontext = itransfer;
+		urb->type = USBFS_URB_TYPE_ISO;
+		/* FIXME: interface for non-ASAP data? */
+		urb->flags = USBFS_URB_ISO_ASAP;
+		urb->endpoint = transfer->endpoint;
+		urb->number_of_packets = urb_packet_offset;
+		urb->buffer = urb_buffer_orig;
+	}
+
+	/* submit URBs */
+	for (i = 0; i < num_urbs; i++) {
+		int r = ioctl(dpriv->fd, IOCTL_USBFS_SUBMITURB, urbs[i]);
+		if (r < 0) {
+			int j;
+
+			if (errno == ENODEV) {
+				r = LIBUSB_ERROR_NO_DEVICE;
+			} else {
+				usbi_err(TRANSFER_CTX(transfer),
+					"submiturb failed error %d errno=%d", r, errno);
+				r = LIBUSB_ERROR_IO;
+			}
+
+			/* if the first URB submission fails, we can simply free up and
+			 * return failure immediately. */
+			if (i == 0) {
+				usbi_dbg("first URB failed, easy peasy");
+				free_iso_urbs(tpriv);
+				return r;
+			}
+
+			/* if it's not the first URB that failed, the situation is a bit
+			 * tricky. we must discard all previous URBs. there are
+			 * complications:
+			 *  - discarding is asynchronous - discarded urbs will be reaped
+			 *    later. the user must not have freed the transfer when the
+			 *    discarded URBs are reaped, otherwise libusb will be using
+			 *    freed memory.
+			 *  - the earlier URBs may have completed successfully and we do
+			 *    not want to throw away any data.
+			 * so, in this case we discard all the previous URBs BUT we report
+			 * that the transfer was submitted successfully. then later when
+			 * the final discard completes we can report error to the user.
+			 */
+			tpriv->reap_action = SUBMIT_FAILED;
+
+			/* The URBs we haven't submitted yet we count as already
+			 * retired. */
+			tpriv->num_retired = num_urbs - i;
+			for (j = 0; j < i; j++) {
+				int tmp = ioctl(dpriv->fd, IOCTL_USBFS_DISCARDURB, urbs[j]);
+				if (tmp && errno != EINVAL)
+					usbi_warn(TRANSFER_CTX(transfer),
+						"unrecognised discard errno %d", errno);
+			}
+
+			usbi_dbg("reporting successful submission but waiting for %d "
+				"discards before reporting error", i);
+			return 0;
+		}
+	}
+
+	return 0;
+}
+
+static int submit_control_transfer(struct usbi_transfer *itransfer)
+{
+	struct linux_transfer_priv *tpriv = usbi_transfer_get_os_priv(itransfer);
+	struct libusb_transfer *transfer =
+		__USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct linux_device_handle_priv *dpriv =
+		__device_handle_priv(transfer->dev_handle);
+	struct usbfs_urb *urb;
+	int r;
+
+	if (tpriv->urbs)
+		return LIBUSB_ERROR_BUSY;
+
+	if (transfer->length - LIBUSB_CONTROL_SETUP_SIZE > MAX_CTRL_BUFFER_LENGTH)
+		return LIBUSB_ERROR_INVALID_PARAM;
+
+	urb = malloc(sizeof(struct usbfs_urb));
+	if (!urb)
+		return LIBUSB_ERROR_NO_MEM;
+	memset(urb, 0, sizeof(struct usbfs_urb));
+	tpriv->urbs = urb;
+	tpriv->reap_action = NORMAL;
+
+	urb->usercontext = itransfer;
+	urb->type = USBFS_URB_TYPE_CONTROL;
+	urb->endpoint = transfer->endpoint;
+	urb->buffer = transfer->buffer;
+	urb->buffer_length = transfer->length;
+
+	r = ioctl(dpriv->fd, IOCTL_USBFS_SUBMITURB, urb);
+	if (r < 0) {
+		free(urb);
+		tpriv->urbs = NULL;
+		if (errno == ENODEV)
+			return LIBUSB_ERROR_NO_DEVICE;
+
+		usbi_err(TRANSFER_CTX(transfer),
+			"submiturb failed error %d errno=%d", r, errno);
+		return LIBUSB_ERROR_IO;
+	}
+	return 0;
+}
+
+static int op_submit_transfer(struct usbi_transfer *itransfer)
+{
+	struct libusb_transfer *transfer =
+		__USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+
+	switch (transfer->type) {
+	case LIBUSB_TRANSFER_TYPE_CONTROL:
+		return submit_control_transfer(itransfer);
+	case LIBUSB_TRANSFER_TYPE_BULK:
+		return submit_bulk_transfer(itransfer, USBFS_URB_TYPE_BULK);
+	case LIBUSB_TRANSFER_TYPE_INTERRUPT:
+		return submit_bulk_transfer(itransfer, USBFS_URB_TYPE_INTERRUPT);
+	case LIBUSB_TRANSFER_TYPE_ISOCHRONOUS:
+		return submit_iso_transfer(itransfer);
+	default:
+		usbi_err(TRANSFER_CTX(transfer),
+			"unknown endpoint type %d", transfer->type);
+		return LIBUSB_ERROR_INVALID_PARAM;
+	}
+}
+
+static int cancel_control_transfer(struct usbi_transfer *itransfer)
+{
+	struct linux_transfer_priv *tpriv = usbi_transfer_get_os_priv(itransfer);
+	struct libusb_transfer *transfer =
+		__USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct linux_device_handle_priv *dpriv =
+		__device_handle_priv(transfer->dev_handle);
+	int r;
+
+	if (!tpriv->urbs)
+		return LIBUSB_ERROR_NOT_FOUND;
+
+	tpriv->reap_action = CANCELLED;
+	r = ioctl(dpriv->fd, IOCTL_USBFS_DISCARDURB, tpriv->urbs);
+	if(r) {
+		if (errno == EINVAL) {
+			usbi_dbg("URB not found --> assuming ready to be reaped");
+			return 0;
+		} else {
+			usbi_err(TRANSFER_CTX(transfer),
+				"unrecognised DISCARD code %d", errno);
+			return LIBUSB_ERROR_OTHER;
+		}
+	}
+
+	return 0;
+}
+
+static int cancel_bulk_transfer(struct usbi_transfer *itransfer)
+{
+	struct linux_transfer_priv *tpriv = usbi_transfer_get_os_priv(itransfer);
+	struct libusb_transfer *transfer =
+		__USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct linux_device_handle_priv *dpriv =
+		__device_handle_priv(transfer->dev_handle);
+	int i;
+
+	if (!tpriv->urbs)
+		return LIBUSB_ERROR_NOT_FOUND;
+
+	if (tpriv->reap_action != ERROR)
+		tpriv->reap_action = CANCELLED;
+
+	for (i = 0; i < tpriv->num_urbs; i++) {
+		int tmp = ioctl(dpriv->fd, IOCTL_USBFS_DISCARDURB, &tpriv->urbs[i]);
+		if (tmp && errno != EINVAL)
+			usbi_warn(TRANSFER_CTX(transfer),
+				"unrecognised discard errno %d", errno);
+	}
+	return 0;
+}
+
+static int cancel_iso_transfer(struct usbi_transfer *itransfer)
+{
+	struct linux_transfer_priv *tpriv = usbi_transfer_get_os_priv(itransfer);
+	struct libusb_transfer *transfer =
+		__USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct linux_device_handle_priv *dpriv =
+		__device_handle_priv(transfer->dev_handle);
+	int i;
+
+	if (!tpriv->iso_urbs)
+		return LIBUSB_ERROR_NOT_FOUND;
+
+	tpriv->reap_action = CANCELLED;
+	for (i = 0; i < tpriv->num_urbs; i++) {
+		int tmp = ioctl(dpriv->fd, IOCTL_USBFS_DISCARDURB, tpriv->iso_urbs[i]);
+		if (tmp && errno != EINVAL)
+			usbi_warn(TRANSFER_CTX(transfer),
+				"unrecognised discard errno %d", errno);
+	}
+	return 0;
+}
+
+static int op_cancel_transfer(struct usbi_transfer *itransfer)
+{
+	struct libusb_transfer *transfer =
+		__USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+
+	switch (transfer->type) {
+	case LIBUSB_TRANSFER_TYPE_CONTROL:
+		return cancel_control_transfer(itransfer);
+	case LIBUSB_TRANSFER_TYPE_BULK:
+	case LIBUSB_TRANSFER_TYPE_INTERRUPT:
+		return cancel_bulk_transfer(itransfer);
+	case LIBUSB_TRANSFER_TYPE_ISOCHRONOUS:
+		return cancel_iso_transfer(itransfer);
+	default:
+		usbi_err(TRANSFER_CTX(transfer),
+			"unknown endpoint type %d", transfer->type);
+		return LIBUSB_ERROR_INVALID_PARAM;
+	}
+}
+
+static void op_clear_transfer_priv(struct usbi_transfer *itransfer)
+{
+	struct libusb_transfer *transfer =
+		__USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct linux_transfer_priv *tpriv = usbi_transfer_get_os_priv(itransfer);
+
+	switch (transfer->type) {
+	case LIBUSB_TRANSFER_TYPE_CONTROL:
+	case LIBUSB_TRANSFER_TYPE_BULK:
+	case LIBUSB_TRANSFER_TYPE_INTERRUPT:
+		free(tpriv->urbs);
+		tpriv->urbs = NULL;
+		break;
+	case LIBUSB_TRANSFER_TYPE_ISOCHRONOUS:
+		free_iso_urbs(tpriv);
+		break;
+	default:
+		usbi_err(TRANSFER_CTX(transfer),
+			"unknown endpoint type %d", transfer->type);
+	}
+}
+
+static int handle_bulk_completion(struct usbi_transfer *itransfer,
+	struct usbfs_urb *urb)
+{
+	struct linux_transfer_priv *tpriv = usbi_transfer_get_os_priv(itransfer);
+	struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct linux_device_handle_priv *dpriv = __device_handle_priv(transfer->dev_handle);
+	int urb_idx = urb - tpriv->urbs;
+
+	usbi_mutex_lock(&itransfer->lock);
+	usbi_dbg("handling completion status %d of bulk urb %d/%d", urb->status,
+		urb_idx + 1, tpriv->num_urbs);
+
+	tpriv->num_retired++;
+
+	if (tpriv->reap_action != NORMAL) {
+		/* cancelled, submit_fail, or completed early */
+		usbi_dbg("abnormal reap: urb status %d", urb->status);
+
+		/* even though we're in the process of cancelling, it's possible that
+		 * we may receive some data in these URBs that we don't want to lose.
+		 * examples:
+		 * 1. while the kernel is cancelling all the packets that make up an
+		 *    URB, a few of them might complete. so we get back a successful
+		 *    cancellation *and* some data.
+		 * 2. we receive a short URB which marks the early completion condition,
+		 *    so we start cancelling the remaining URBs. however, we're too
+		 *    slow and another URB completes (or at least completes partially).
+		 *
+		 * When this happens, our objectives are not to lose any "surplus" data,
+		 * and also to stick it at the end of the previously-received data
+		 * (closing any holes), so that libusb reports the total amount of
+		 * transferred data and presents it in a contiguous chunk.
+		 */
+		if (urb->actual_length > 0) {
+			unsigned char *target = transfer->buffer + itransfer->transferred;
+			usbi_dbg("received %d bytes of surplus data", urb->actual_length);
+			if (urb->buffer != target) {
+				usbi_dbg("moving surplus data from offset %d to offset %d",
+					(unsigned char *) urb->buffer - transfer->buffer,
+					target - transfer->buffer);
+				memmove(target, urb->buffer, urb->actual_length);
+			}
+			itransfer->transferred += urb->actual_length;
+		}
+
+		if (tpriv->num_retired == tpriv->num_urbs) {
+			usbi_dbg("abnormal reap: last URB handled, reporting");
+			if (tpriv->reap_action != COMPLETED_EARLY &&
+			    tpriv->reap_status == LIBUSB_TRANSFER_COMPLETED)
+				tpriv->reap_status = LIBUSB_TRANSFER_ERROR;
+			goto completed;
+		}
+		goto out_unlock;
+	}
+
+	if (urb->status == 0 || urb->status == -EREMOTEIO ||
+			(urb->status == -EOVERFLOW && urb->actual_length > 0))
+		itransfer->transferred += urb->actual_length;
+
+
+	switch (urb->status) {
+	case 0:
+		break;
+	case -EREMOTEIO: /* short transfer */
+		break;
+	case -EPIPE:
+		usbi_dbg("detected endpoint stall");
+		if (tpriv->reap_status == LIBUSB_TRANSFER_COMPLETED)
+			tpriv->reap_status = LIBUSB_TRANSFER_STALL;
+		goto cancel_remaining;
+	case -EOVERFLOW:
+		/* overflow can only ever occur in the last urb */
+		usbi_dbg("overflow, actual_length=%d", urb->actual_length);
+		if (tpriv->reap_status == LIBUSB_TRANSFER_COMPLETED)
+			tpriv->reap_status = LIBUSB_TRANSFER_OVERFLOW;
+		goto completed;
+	case -ETIME:
+	case -EPROTO:
+	case -EILSEQ:
+		/* These can happen on *any* urb of a multi-urb transfer, so
+		 * save a status and tear down rest of the transfer */
+		usbi_dbg("low level error %d", urb->status);
+		tpriv->reap_action = ERROR;
+		if (tpriv->reap_status == LIBUSB_TRANSFER_COMPLETED)
+			tpriv->reap_status = LIBUSB_TRANSFER_ERROR;
+		goto cancel_remaining;
+	default:
+		usbi_warn(ITRANSFER_CTX(itransfer),
+			"unrecognised urb status %d", urb->status);
+		if (tpriv->reap_status == LIBUSB_TRANSFER_COMPLETED)
+			tpriv->reap_status = LIBUSB_TRANSFER_ERROR;
+		goto cancel_remaining;
+	}
+
+	/* if we're the last urb or we got less data than requested then we're
+	 * done */
+	if (urb_idx == tpriv->num_urbs - 1) {
+		usbi_dbg("last URB in transfer --> complete!");
+		goto completed;
+	} else if (urb->actual_length < urb->buffer_length) {
+		usbi_dbg("short transfer %d/%d --> complete!",
+			urb->actual_length, urb->buffer_length);
+		if (tpriv->reap_action == NORMAL)
+			tpriv->reap_action = COMPLETED_EARLY;
+	} else
+		goto out_unlock;
+
+cancel_remaining:
+	if (tpriv->num_retired == tpriv->num_urbs) /* nothing to cancel */
+		goto completed;
+
+	/* cancel remaining urbs and wait for their completion before
+	 * reporting results */
+	while (++urb_idx < tpriv->num_urbs) {
+		/* remaining URBs with continuation flag are
+		 * automatically cancelled by the kernel */
+		if (tpriv->urbs[urb_idx].flags & USBFS_URB_BULK_CONTINUATION)
+			continue;
+		int tmp = ioctl(dpriv->fd, IOCTL_USBFS_DISCARDURB, &tpriv->urbs[urb_idx]);
+		if (tmp && errno != EINVAL)
+			usbi_warn(TRANSFER_CTX(transfer),
+				"unrecognised discard errno %d", errno);
+	}
+
+out_unlock:
+	usbi_mutex_unlock(&itransfer->lock);
+	return 0;
+
+completed:
+	free(tpriv->urbs);
+	tpriv->urbs = NULL;
+	usbi_mutex_unlock(&itransfer->lock);
+	return CANCELLED == tpriv->reap_action ?
+		usbi_handle_transfer_cancellation(itransfer) :
+		usbi_handle_transfer_completion(itransfer, tpriv->reap_status);
+}
+
+static int handle_iso_completion(struct usbi_transfer *itransfer,
+	struct usbfs_urb *urb)
+{
+	struct libusb_transfer *transfer =
+		__USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct linux_transfer_priv *tpriv = usbi_transfer_get_os_priv(itransfer);
+	int num_urbs = tpriv->num_urbs;
+	int urb_idx = 0;
+	int i;
+
+	usbi_mutex_lock(&itransfer->lock);
+	for (i = 0; i < num_urbs; i++) {
+		if (urb == tpriv->iso_urbs[i]) {
+			urb_idx = i + 1;
+			break;
+		}
+	}
+	if (urb_idx == 0) {
+		usbi_err(TRANSFER_CTX(transfer), "could not locate urb!");
+		usbi_mutex_unlock(&itransfer->lock);
+		return LIBUSB_ERROR_NOT_FOUND;
+	}
+
+	usbi_dbg("handling completion status %d of iso urb %d/%d", urb->status,
+		urb_idx, num_urbs);
+
+	if (urb->status == 0) {
+		/* copy isochronous results back in */
+
+		for (i = 0; i < urb->number_of_packets; i++) {
+			struct usbfs_iso_packet_desc *urb_desc = &urb->iso_frame_desc[i];
+			struct libusb_iso_packet_descriptor *lib_desc =
+				&transfer->iso_packet_desc[tpriv->iso_packet_offset++];
+			lib_desc->status = urb_desc->status;
+			lib_desc->actual_length = urb_desc->actual_length;
+		}
+	}
+
+	tpriv->num_retired++;
+
+	if (tpriv->reap_action != NORMAL) { /* cancelled or submit_fail */
+		usbi_dbg("CANCEL: urb status %d", urb->status);
+
+		if (tpriv->num_retired == num_urbs) {
+			usbi_dbg("CANCEL: last URB handled, reporting");
+			free_iso_urbs(tpriv);
+			if (tpriv->reap_action == CANCELLED) {
+				usbi_mutex_unlock(&itransfer->lock);
+				return usbi_handle_transfer_cancellation(itransfer);
+			} else {
+				usbi_mutex_unlock(&itransfer->lock);
+				return usbi_handle_transfer_completion(itransfer,
+					LIBUSB_TRANSFER_ERROR);
+			}
+		}
+		goto out;
+	}
+
+	switch (urb->status) {
+	case 0:
+		break;
+	case -ETIME:
+	case -EPROTO:
+	case -EILSEQ:
+		usbi_dbg("low-level USB error %d", urb->status);
+		break;
+	default:
+		usbi_warn(TRANSFER_CTX(transfer),
+			"unrecognised urb status %d", urb->status);
+		break;
+	}
+
+	/* if we're the last urb or we got less data than requested then we're
+	 * done */
+	if (urb_idx == num_urbs) {
+		usbi_dbg("last URB in transfer --> complete!");
+		free_iso_urbs(tpriv);
+		usbi_mutex_unlock(&itransfer->lock);
+		return usbi_handle_transfer_completion(itransfer, LIBUSB_TRANSFER_COMPLETED);
+	}
+
+out:
+	usbi_mutex_unlock(&itransfer->lock);
+	return 0;
+}
+
+static int handle_control_completion(struct usbi_transfer *itransfer,
+	struct usbfs_urb *urb)
+{
+	struct linux_transfer_priv *tpriv = usbi_transfer_get_os_priv(itransfer);
+	int status;
+
+	usbi_mutex_lock(&itransfer->lock);
+	usbi_dbg("handling completion status %d", urb->status);
+
+	if (urb->status == 0)
+		itransfer->transferred += urb->actual_length;
+
+	if (tpriv->reap_action == CANCELLED) {
+		if (urb->status != 0 && urb->status != -ENOENT)
+			usbi_warn(ITRANSFER_CTX(itransfer),
+				"cancel: unrecognised urb status %d", urb->status);
+		free(tpriv->urbs);
+		tpriv->urbs = NULL;
+		usbi_mutex_unlock(&itransfer->lock);
+		return usbi_handle_transfer_cancellation(itransfer);
+	}
+
+	switch (urb->status) {
+	case 0:
+		itransfer->transferred = urb->actual_length;
+		status = LIBUSB_TRANSFER_COMPLETED;
+		break;
+	case -EPIPE:
+		usbi_dbg("unsupported control request");
+		status = LIBUSB_TRANSFER_STALL;
+		break;
+	case -ETIME:
+	case -EPROTO:
+	case -EILSEQ:
+		usbi_dbg("low-level bus error occurred");
+		status = LIBUSB_TRANSFER_ERROR;
+		break;
+	default:
+		usbi_warn(ITRANSFER_CTX(itransfer),
+			"unrecognised urb status %d", urb->status);
+		status = LIBUSB_TRANSFER_ERROR;
+		break;
+	}
+
+	free(tpriv->urbs);
+	tpriv->urbs = NULL;
+	usbi_mutex_unlock(&itransfer->lock);
+	return usbi_handle_transfer_completion(itransfer, status);
+}
+
+static int reap_for_handle(struct libusb_device_handle *handle)
+{
+	struct linux_device_handle_priv *hpriv = __device_handle_priv(handle);
+	int r;
+	struct usbfs_urb *urb;
+	struct usbi_transfer *itransfer;
+	struct libusb_transfer *transfer;
+
+	r = ioctl(hpriv->fd, IOCTL_USBFS_REAPURBNDELAY, &urb);
+	if (r == -1 && errno == EAGAIN)
+		return 1;
+	if (r < 0) {
+		if (errno == ENODEV)
+			return LIBUSB_ERROR_NO_DEVICE;
+
+		usbi_err(HANDLE_CTX(handle), "reap failed error %d errno=%d",
+			r, errno);
+		return LIBUSB_ERROR_IO;
+	}
+
+	itransfer = urb->usercontext;
+	transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+
+	usbi_dbg("urb type=%d status=%d transferred=%d", urb->type, urb->status,
+		urb->actual_length);
+
+	switch (transfer->type) {
+	case LIBUSB_TRANSFER_TYPE_ISOCHRONOUS:
+		return handle_iso_completion(itransfer, urb);
+	case LIBUSB_TRANSFER_TYPE_BULK:
+	case LIBUSB_TRANSFER_TYPE_INTERRUPT:
+		return handle_bulk_completion(itransfer, urb);
+	case LIBUSB_TRANSFER_TYPE_CONTROL:
+		return handle_control_completion(itransfer, urb);
+	default:
+		usbi_err(HANDLE_CTX(handle), "unrecognised endpoint type %x",
+			transfer->type);
+		return LIBUSB_ERROR_OTHER;
+	}
+}
+
+static int op_handle_events(struct libusb_context *ctx,
+	struct pollfd *fds, nfds_t nfds, int num_ready)
+{
+	int r;
+	int i = 0;
+
+	usbi_mutex_lock(&ctx->open_devs_lock);
+	for (i = 0; i < nfds && num_ready > 0; i++) {
+		struct pollfd *pollfd = &fds[i];
+		struct libusb_device_handle *handle;
+		struct linux_device_handle_priv *hpriv = NULL;
+
+		if (!pollfd->revents)
+			continue;
+
+		num_ready--;
+		list_for_each_entry(handle, &ctx->open_devs, list, struct libusb_device_handle) {
+			hpriv =  __device_handle_priv(handle);
+			if (hpriv->fd == pollfd->fd)
+				break;
+		}
+
+		if (pollfd->revents & POLLERR) {
+			usbi_remove_pollfd(HANDLE_CTX(handle), hpriv->fd);
+			usbi_handle_disconnect(handle);
+			continue;
+		}
+
+		r = reap_for_handle(handle);
+		if (r == 1 || r == LIBUSB_ERROR_NO_DEVICE)
+			continue;
+		else if (r < 0)
+			goto out;
+	}
+
+	r = 0;
+out:
+	usbi_mutex_unlock(&ctx->open_devs_lock);
+	return r;
+}
+
+static int op_clock_gettime(int clk_id, struct timespec *tp)
+{
+	switch (clk_id) {
+	case USBI_CLOCK_MONOTONIC:
+		return clock_gettime(monotonic_clkid, tp);
+	case USBI_CLOCK_REALTIME:
+		return clock_gettime(CLOCK_REALTIME, tp);
+	default:
+		return LIBUSB_ERROR_INVALID_PARAM;
+  }
+}
+
+#ifdef USBI_TIMERFD_AVAILABLE
+static clockid_t op_get_timerfd_clockid(void)
+{
+	return monotonic_clkid;
+
+}
+#endif
+
+const struct usbi_os_backend linux_usbfs_backend = {
+	.name = "Linux usbfs",
+	.init = op_init,
+	.exit = NULL,
+	.get_device_list = op_get_device_list,
+	.get_device_descriptor = op_get_device_descriptor,
+	.get_active_config_descriptor = op_get_active_config_descriptor,
+	.get_config_descriptor = op_get_config_descriptor,
+
+	.open = op_open,
+	.close = op_close,
+	.get_configuration = op_get_configuration,
+	.set_configuration = op_set_configuration,
+	.claim_interface = op_claim_interface,
+	.release_interface = op_release_interface,
+
+	.set_interface_altsetting = op_set_interface,
+	.clear_halt = op_clear_halt,
+	.reset_device = op_reset_device,
+
+	.kernel_driver_active = op_kernel_driver_active,
+	.detach_kernel_driver = op_detach_kernel_driver,
+	.attach_kernel_driver = op_attach_kernel_driver,
+
+	.destroy_device = op_destroy_device,
+
+	.submit_transfer = op_submit_transfer,
+	.cancel_transfer = op_cancel_transfer,
+	.clear_transfer_priv = op_clear_transfer_priv,
+
+	.handle_events = op_handle_events,
+
+	.clock_gettime = op_clock_gettime,
+
+#ifdef USBI_TIMERFD_AVAILABLE
+	.get_timerfd_clockid = op_get_timerfd_clockid,
+#endif
+
+	.device_priv_size = sizeof(struct linux_device_priv),
+	.device_handle_priv_size = sizeof(struct linux_device_handle_priv),
+	.transfer_priv_size = sizeof(struct linux_transfer_priv),
+	.add_iso_packet_size = 0,
+};
+
diff --git a/include/libusb-1.0/os/linux_usbfs.h b/include/libusb-1.0/os/linux_usbfs.h
new file mode 100644
index 0000000..bd02edc
--- /dev/null
+++ b/include/libusb-1.0/os/linux_usbfs.h
@@ -0,0 +1,138 @@
+/*
+ * usbfs header structures
+ * Copyright (C) 2007 Daniel Drake <dsd@gentoo.org>
+ * Copyright (c) 2001 Johannes Erdfelt <johannes@erdfelt.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef __LIBUSB_USBFS_H__
+#define __LIBUSB_USBFS_H__
+
+#define SYSFS_DEVICE_PATH "/sys/bus/usb/devices"
+
+struct usbfs_ctrltransfer {
+	/* keep in sync with usbdevice_fs.h:usbdevfs_ctrltransfer */
+	uint8_t  bmRequestType;
+	uint8_t  bRequest;
+	uint16_t wValue;
+	uint16_t wIndex;
+	uint16_t wLength;
+
+	uint32_t timeout;	/* in milliseconds */
+
+	/* pointer to data */
+	void *data;
+};
+
+struct usbfs_bulktransfer {
+	/* keep in sync with usbdevice_fs.h:usbdevfs_bulktransfer */
+	unsigned int ep;
+	unsigned int len;
+	unsigned int timeout;	/* in milliseconds */
+
+	/* pointer to data */
+	void *data;
+};
+
+struct usbfs_setinterface {
+	/* keep in sync with usbdevice_fs.h:usbdevfs_setinterface */
+	unsigned int interface;
+	unsigned int altsetting;
+};
+
+#define USBFS_MAXDRIVERNAME 255
+
+struct usbfs_getdriver {
+	unsigned int interface;
+	char driver[USBFS_MAXDRIVERNAME + 1];
+};
+
+#define USBFS_URB_SHORT_NOT_OK		0x01
+#define USBFS_URB_ISO_ASAP			0x02
+#define USBFS_URB_BULK_CONTINUATION	0x04
+#define USBFS_URB_QUEUE_BULK		0x10
+
+enum usbfs_urb_type {
+	USBFS_URB_TYPE_ISO = 0,
+	USBFS_URB_TYPE_INTERRUPT = 1,
+	USBFS_URB_TYPE_CONTROL = 2,
+	USBFS_URB_TYPE_BULK = 3,
+};
+
+struct usbfs_iso_packet_desc {
+	unsigned int length;
+	unsigned int actual_length;
+	unsigned int status;
+};
+
+#define MAX_ISO_BUFFER_LENGTH		32768
+#define MAX_BULK_BUFFER_LENGTH		16384
+#define MAX_CTRL_BUFFER_LENGTH		4096
+
+struct usbfs_urb {
+	unsigned char type;
+	unsigned char endpoint;
+	int status;
+	unsigned int flags;
+	void *buffer;
+	int buffer_length;
+	int actual_length;
+	int start_frame;
+	int number_of_packets;
+	int error_count;
+	unsigned int signr;
+	void *usercontext;
+	struct usbfs_iso_packet_desc iso_frame_desc[0];
+};
+
+struct usbfs_connectinfo {
+	unsigned int devnum;
+	unsigned char slow;
+};
+
+struct usbfs_ioctl {
+	int ifno;	/* interface 0..N ; negative numbers reserved */
+	int ioctl_code;	/* MUST encode size + direction of data so the
+			 * macros in <asm/ioctl.h> give correct values */
+	void *data;	/* param buffer (in, or out) */
+};
+
+struct usbfs_hub_portinfo {
+	unsigned char numports;
+	unsigned char port[127];	/* port to device num mapping */
+};
+
+#define IOCTL_USBFS_CONTROL	_IOWR('U', 0, struct usbfs_ctrltransfer)
+#define IOCTL_USBFS_BULK		_IOWR('U', 2, struct usbfs_bulktransfer)
+#define IOCTL_USBFS_RESETEP	_IOR('U', 3, unsigned int)
+#define IOCTL_USBFS_SETINTF	_IOR('U', 4, struct usbfs_setinterface)
+#define IOCTL_USBFS_SETCONFIG	_IOR('U', 5, unsigned int)
+#define IOCTL_USBFS_GETDRIVER	_IOW('U', 8, struct usbfs_getdriver)
+#define IOCTL_USBFS_SUBMITURB	_IOR('U', 10, struct usbfs_urb)
+#define IOCTL_USBFS_DISCARDURB	_IO('U', 11)
+#define IOCTL_USBFS_REAPURB	_IOW('U', 12, void *)
+#define IOCTL_USBFS_REAPURBNDELAY	_IOW('U', 13, void *)
+#define IOCTL_USBFS_CLAIMINTF	_IOR('U', 15, unsigned int)
+#define IOCTL_USBFS_RELEASEINTF	_IOR('U', 16, unsigned int)
+#define IOCTL_USBFS_CONNECTINFO	_IOW('U', 17, struct usbfs_connectinfo)
+#define IOCTL_USBFS_IOCTL         _IOWR('U', 18, struct usbfs_ioctl)
+#define IOCTL_USBFS_HUB_PORTINFO	_IOR('U', 19, struct usbfs_hub_portinfo)
+#define IOCTL_USBFS_RESET		_IO('U', 20)
+#define IOCTL_USBFS_CLEAR_HALT	_IOR('U', 21, unsigned int)
+#define IOCTL_USBFS_DISCONNECT	_IO('U', 22)
+#define IOCTL_USBFS_CONNECT	_IO('U', 23)
+
+#endif
diff --git a/include/libusb-1.0/os/poll_posix.h b/include/libusb-1.0/os/poll_posix.h
new file mode 100644
index 0000000..17298a5
--- /dev/null
+++ b/include/libusb-1.0/os/poll_posix.h
@@ -0,0 +1,12 @@
+#ifndef __LIBUSB_POLL_POSIX_H__
+#define __LIBUSB_POLL_POSIX_H__
+
+#include <unistd.h>
+#include <poll.h>
+#define usbi_write write
+#define usbi_read read
+#define usbi_close close
+#define usbi_pipe pipe
+#define usbi_poll poll
+
+#endif /* __LIBUSB_POLL_POSIX_H__ */
diff --git a/include/libusb-1.0/os/poll_windows.c b/include/libusb-1.0/os/poll_windows.c
new file mode 100644
index 0000000..9ae9895
--- /dev/null
+++ b/include/libusb-1.0/os/poll_windows.c
@@ -0,0 +1,860 @@
+/*
+ * poll_windows: poll compatibility wrapper for Windows
+ * Copyright (C) 2009-2010 Pete Batard <pbatard@gmail.com>
+ * With contributions from Michael Plante, Orin Eman et al.
+ * Parts of poll implementation from libusb-win32, by Stephan Meyer et al.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ */
+
+/*
+ * poll() and pipe() Windows compatibility layer for libusb 1.0
+ *
+ * The way this layer works is by using OVERLAPPED with async I/O transfers, as
+ * OVERLAPPED have an associated event which is flagged for I/O completion.
+ *
+ * For USB pollable async I/O, you would typically:
+ * - obtain a Windows HANDLE to a file or device that has been opened in
+ *   OVERLAPPED mode
+ * - call usbi_create_fd with this handle to obtain a custom fd.
+ *   Note that if you need simultaneous R/W access, you need to call create_fd
+ *   twice, once in _O_RDONLY and once in _O_WRONLY mode to obtain 2 separate
+ *   pollable fds
+ * - leave the core functions call the poll routine and flag POLLIN/POLLOUT
+ *
+ * The pipe pollable synchronous I/O works using the overlapped event associated
+ * with a fake pipe. The read/write functions are only meant to be used in that
+ * context.
+ */
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <io.h>
+
+#include <libusbi.h>
+
+// Uncomment to debug the polling layer
+//#define DEBUG_POLL_WINDOWS
+#if defined(DEBUG_POLL_WINDOWS)
+#define poll_dbg usbi_dbg
+#else
+// MSVC6 cannot use a variadic argument and non MSVC
+// compilers produce warnings if parenthesis are ommitted.
+#if defined(_MSC_VER)
+#define poll_dbg
+#else
+#define poll_dbg(...)
+#endif
+#endif
+
+#if defined(_PREFAST_)
+#pragma warning(disable:28719)
+#endif
+
+#if defined(__CYGWIN__)
+// cygwin produces a warning unless these prototypes are defined
+extern int _close(int fd);
+extern int _snprintf(char *buffer, size_t count, const char *format, ...);
+extern int cygwin_attach_handle_to_fd(char *name, int fd, HANDLE handle, int bin, int access_mode);
+// _open_osfhandle() is not available on cygwin, but we can emulate
+// it for our needs with cygwin_attach_handle_to_fd()
+static inline int _open_osfhandle(intptr_t osfhandle, int flags)
+{
+	int access_mode;
+	switch (flags) {
+	case _O_RDONLY:
+		access_mode = GENERIC_READ;
+		break;
+	case _O_WRONLY:
+		access_mode = GENERIC_WRITE;
+		break;
+	case _O_RDWR:
+		access_mode = GENERIC_READ|GENERIC_WRITE;
+		break;
+	default:
+		usbi_err(NULL, "unsupported access mode");
+		return -1;
+	}
+	return cygwin_attach_handle_to_fd("/dev/null", -1, (HANDLE)osfhandle, -1, access_mode);
+}
+#endif
+
+#define CHECK_INIT_POLLING do {if(!is_polling_set) init_polling();} while(0)
+
+// public fd data
+const struct winfd INVALID_WINFD = {-1, INVALID_HANDLE_VALUE, NULL, RW_NONE};
+struct winfd poll_fd[MAX_FDS];
+// internal fd data
+struct {
+	CRITICAL_SECTION mutex; // lock for fds
+	// Additional variables for XP CancelIoEx partial emulation
+	HANDLE original_handle;
+	DWORD thread_id;
+} _poll_fd[MAX_FDS];
+
+// globals
+BOOLEAN is_polling_set = FALSE;
+#if defined(DYNAMIC_FDS)
+HANDLE fd_update = INVALID_HANDLE_VALUE;	// event to notify poll of fd update
+HANDLE new_fd[MAX_FDS];		// overlapped event handles for fds created since last poll
+unsigned nb_new_fds = 0;	// nb new fds created since last poll
+usbi_mutex_t new_fd_mutex;	// mutex required for the above
+#endif
+LONG pipe_number = 0;
+static volatile LONG compat_spinlock = 0;
+
+// CancelIoEx, available on Vista and later only, provides the ability to cancel
+// a single transfer (OVERLAPPED) when used. As it may not be part of any of the
+// platform headers, we hook into the Kernel32 system DLL directly to seek it.
+static BOOL (__stdcall *pCancelIoEx)(HANDLE, LPOVERLAPPED) = NULL;
+#define CancelIoEx_Available (pCancelIoEx != NULL)
+__inline BOOL cancel_io(int index)
+{
+	if ((index < 0) || (index >= MAX_FDS)) {
+		return FALSE;
+	}
+
+	if ( (poll_fd[index].fd < 0) || (poll_fd[index].handle == INVALID_HANDLE_VALUE)
+	  || (poll_fd[index].handle == 0) || (poll_fd[index].overlapped == NULL) ) {
+		return TRUE;
+	}
+	if (CancelIoEx_Available) {
+		return (*pCancelIoEx)(poll_fd[index].handle, poll_fd[index].overlapped);
+	}
+	if (_poll_fd[index].thread_id == GetCurrentThreadId()) {
+		return CancelIo(poll_fd[index].handle);
+	}
+	usbi_warn(NULL, "Unable to cancel I/O that was started from another thread");
+	return FALSE;
+}
+
+// Init
+void init_polling(void)
+{
+	int i;
+
+	while (InterlockedExchange((LONG *)&compat_spinlock, 1) == 1) {
+		SleepEx(0, TRUE);
+	}
+	if (!is_polling_set) {
+		pCancelIoEx = (BOOL (__stdcall *)(HANDLE,LPOVERLAPPED))
+			GetProcAddress(GetModuleHandle("KERNEL32"), "CancelIoEx");
+		usbi_dbg("Will use CancelIo%s for I/O cancellation",
+			CancelIoEx_Available?"Ex":"");
+		for (i=0; i<MAX_FDS; i++) {
+			poll_fd[i] = INVALID_WINFD;
+			_poll_fd[i].original_handle = INVALID_HANDLE_VALUE;
+			_poll_fd[i].thread_id = 0;
+			InitializeCriticalSection(&_poll_fd[i].mutex);
+		}
+#if defined(DYNAMIC_FDS)
+		// We need to create an update event so that poll is warned when there
+		// are new/deleted fds during a timeout wait operation
+		fd_update = CreateEvent(NULL, TRUE, FALSE, NULL);
+		if (fd_update == NULL) {
+			usbi_err(NULL, "unable to create update event");
+		}
+		usbi_mutex_init(&new_fd_mutex, NULL);
+		nb_new_fds = 0;
+#endif
+		is_polling_set = TRUE;
+	}
+	compat_spinlock = 0;
+}
+
+// Internal function to retrieve the table index (and lock the fd mutex)
+int _fd_to_index_and_lock(int fd)
+{
+	int i;
+
+	if (fd <= 0)
+		return -1;
+
+	for (i=0; i<MAX_FDS; i++) {
+		if (poll_fd[i].fd == fd) {
+			EnterCriticalSection(&_poll_fd[i].mutex);
+			// fd might have changed before we got to critical
+			if (poll_fd[i].fd != fd) {
+				LeaveCriticalSection(&_poll_fd[i].mutex);
+				continue;
+			}
+			return i;
+		}
+	}
+	return -1;
+}
+
+OVERLAPPED *create_overlapped(void)
+{
+	OVERLAPPED *overlapped = calloc(1, sizeof(OVERLAPPED));
+	if (overlapped == NULL) {
+		return NULL;
+	}
+	overlapped->hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
+	if(overlapped->hEvent == NULL) {
+		free (overlapped);
+		return NULL;
+	}
+	return overlapped;
+}
+
+void free_overlapped(OVERLAPPED *overlapped)
+{
+	if (overlapped == NULL)
+		return;
+
+	if ( (overlapped->hEvent != 0)
+	  && (overlapped->hEvent != INVALID_HANDLE_VALUE) ) {
+		CloseHandle(overlapped->hEvent);
+	}
+	free(overlapped);
+}
+
+void reset_overlapped(OVERLAPPED *overlapped)
+{
+	HANDLE event_handle;
+	if (overlapped == NULL)
+		return;
+
+	event_handle = overlapped->hEvent;
+	if (event_handle != NULL) {
+		ResetEvent(event_handle);
+	}
+	memset(overlapped, 0, sizeof(OVERLAPPED));
+	overlapped->hEvent = event_handle;
+}
+
+void exit_polling(void)
+{
+	int i;
+
+	while (InterlockedExchange((LONG *)&compat_spinlock, 1) == 1) {
+		SleepEx(0, TRUE);
+	}
+	if (is_polling_set) {
+		is_polling_set = FALSE;
+
+		for (i=0; i<MAX_FDS; i++) {
+			// Cancel any async I/O (handle can be invalid)
+			cancel_io(i);
+			// If anything was pending on that I/O, it should be
+			// terminating, and we should be able to access the fd
+			// mutex lock before too long
+			EnterCriticalSection(&_poll_fd[i].mutex);
+			if ( (poll_fd[i].fd > 0) && (poll_fd[i].handle != INVALID_HANDLE_VALUE) && (poll_fd[i].handle != 0)
+			  && (GetFileType(poll_fd[i].handle) == FILE_TYPE_UNKNOWN) ) {
+				_close(poll_fd[i].fd);
+			}
+			free_overlapped(poll_fd[i].overlapped);
+			if (!CancelIoEx_Available) {
+				// Close duplicate handle
+				if (_poll_fd[i].original_handle != INVALID_HANDLE_VALUE) {
+					CloseHandle(poll_fd[i].handle);
+				}
+			}
+			poll_fd[i] = INVALID_WINFD;
+#if defined(DYNAMIC_FDS)
+			usbi_mutex_destroy(&new_fd_mutex);
+			CloseHandle(fd_update);
+			fd_update = INVALID_HANDLE_VALUE;
+#endif
+			LeaveCriticalSection(&_poll_fd[i].mutex);
+			DeleteCriticalSection(&_poll_fd[i].mutex);
+		}
+	}
+	compat_spinlock = 0;
+}
+
+/*
+ * Create a fake pipe.
+ * As libusb only uses pipes for signaling, all we need from a pipe is an
+ * event. To that extent, we create a single wfd and overlapped as a means
+ * to access that event.
+ */
+int usbi_pipe(int filedes[2])
+{
+	int i;
+	HANDLE handle;
+	OVERLAPPED* overlapped;
+
+	CHECK_INIT_POLLING;
+
+	overlapped = calloc(1, sizeof(OVERLAPPED));
+	if (overlapped == NULL) {
+		return -1;
+	}
+	// The overlapped must have status pending for signaling to work in poll
+	overlapped->Internal = STATUS_PENDING;
+	overlapped->InternalHigh = 0;
+
+	// Read end of the "pipe"
+	handle = CreateFileA("NUL", 0, 0, NULL, OPEN_EXISTING, 0, NULL);
+	if (handle == INVALID_HANDLE_VALUE) {
+		usbi_err(NULL, "could not create pipe: errcode %d", (int)GetLastError());
+		goto out1;
+	}
+	filedes[0] = _open_osfhandle((intptr_t)handle, _O_RDONLY);
+	// We can use the same handle for both ends
+	filedes[1] = filedes[0];
+	poll_dbg("pipe filedes = %d", filedes[0]);
+
+	// Note: manual reset must be true (second param) as the reset occurs in read
+	overlapped->hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
+	if(!overlapped->hEvent) {
+		goto out2;
+	}
+
+	for (i=0; i<MAX_FDS; i++) {
+		if (poll_fd[i].fd < 0) {
+			EnterCriticalSection(&_poll_fd[i].mutex);
+			// fd might have been allocated before we got to critical
+			if (poll_fd[i].fd >= 0) {
+				LeaveCriticalSection(&_poll_fd[i].mutex);
+				continue;
+			}
+
+			poll_fd[i].fd = filedes[0];
+			poll_fd[i].handle = handle;
+			poll_fd[i].overlapped = overlapped;
+			// There's no polling on the write end, so we just use READ for our needs
+			poll_fd[i].rw = RW_READ;
+			_poll_fd[i].original_handle = INVALID_HANDLE_VALUE;
+			LeaveCriticalSection(&_poll_fd[i].mutex);
+			return 0;
+		}
+	}
+
+	CloseHandle(overlapped->hEvent);
+out2:
+	CloseHandle(handle);
+out1:
+	free(overlapped);
+	return -1;
+}
+
+/*
+ * Create both an fd and an OVERLAPPED from an open Windows handle, so that
+ * it can be used with our polling function
+ * The handle MUST support overlapped transfers (usually requires CreateFile
+ * with FILE_FLAG_OVERLAPPED)
+ * Return a pollable file descriptor struct, or INVALID_WINFD on error
+ *
+ * Note that the fd returned by this function is a per-transfer fd, rather
+ * than a per-session fd and cannot be used for anything else but our
+ * custom functions (the fd itself points to the NUL: device)
+ * if you plan to do R/W on the same handle, you MUST create 2 fds: one for
+ * read and one for write. Using a single R/W fd is unsupported and will
+ * produce unexpected results
+ */
+struct winfd usbi_create_fd(HANDLE handle, int access_mode)
+{
+	int i, fd;
+	struct winfd wfd = INVALID_WINFD;
+	OVERLAPPED* overlapped = NULL;
+
+	CHECK_INIT_POLLING;
+
+	if ((handle == 0) || (handle == INVALID_HANDLE_VALUE)) {
+		return INVALID_WINFD;
+	}
+
+	if ((access_mode != _O_RDONLY) && (access_mode != _O_WRONLY)) {
+		usbi_warn(NULL, "only one of _O_RDONLY or _O_WRONLY are supported.\n"
+			"If you want to poll for R/W simultaneously, create multiple fds from the same handle.");
+		return INVALID_WINFD;
+	}
+	if (access_mode == _O_RDONLY) {
+		wfd.rw = RW_READ;
+	} else {
+		wfd.rw = RW_WRITE;
+	}
+
+	// Ensure that we get a non system conflicting unique fd
+	fd = _open_osfhandle((intptr_t)CreateFileA("NUL", 0, 0,
+		NULL, OPEN_EXISTING, 0, NULL), _O_RDWR);
+	if (fd < 0) {
+		return INVALID_WINFD;
+	}
+
+	overlapped = create_overlapped();
+	if(overlapped == NULL) {
+		_close(fd);
+		return INVALID_WINFD;
+	}
+
+	for (i=0; i<MAX_FDS; i++) {
+		if (poll_fd[i].fd < 0) {
+			EnterCriticalSection(&_poll_fd[i].mutex);
+			// fd might have been removed before we got to critical
+			if (poll_fd[i].fd >= 0) {
+				LeaveCriticalSection(&_poll_fd[i].mutex);
+				continue;
+			}
+			wfd.fd = fd;
+			// Attempt to emulate some of the CancelIoEx behaviour on platforms
+			// that don't have it
+			if (!CancelIoEx_Available) {
+				_poll_fd[i].thread_id = GetCurrentThreadId();
+				if (!DuplicateHandle(GetCurrentProcess(), handle, GetCurrentProcess(),
+					&wfd.handle, 0, TRUE, DUPLICATE_SAME_ACCESS)) {
+					usbi_dbg("could not duplicate handle for CancelIo - using original one");
+					wfd.handle = handle;
+					// Make sure we won't close the original handle on fd deletion then
+					_poll_fd[i].original_handle = INVALID_HANDLE_VALUE;
+				} else {
+					_poll_fd[i].original_handle = handle;
+				}
+			} else {
+				wfd.handle = handle;
+			}
+			wfd.overlapped = overlapped;
+			memcpy(&poll_fd[i], &wfd, sizeof(struct winfd));
+			LeaveCriticalSection(&_poll_fd[i].mutex);
+#if defined(DYNAMIC_FDS)
+			usbi_mutex_lock(&new_fd_mutex);
+			new_fd[nb_new_fds++] = overlapped->hEvent;
+			usbi_mutex_unlock(&new_fd_mutex);
+			// Notify poll that fds have been updated
+			SetEvent(fd_update);
+#endif
+			return wfd;
+		}
+	}
+	free_overlapped(overlapped);
+	_close(fd);
+	return INVALID_WINFD;
+}
+
+void _free_index(int index)
+{
+	// Cancel any async IO (Don't care about the validity of our handles for this)
+	cancel_io(index);
+	// close fake handle for devices
+	if ( (poll_fd[index].handle != INVALID_HANDLE_VALUE) && (poll_fd[index].handle != 0)
+	  && (GetFileType(poll_fd[index].handle) == FILE_TYPE_UNKNOWN) ) {
+		_close(poll_fd[index].fd);
+	}
+	// close the duplicate handle (if we have an actual duplicate)
+	if (!CancelIoEx_Available) {
+		if (_poll_fd[index].original_handle != INVALID_HANDLE_VALUE) {
+			CloseHandle(poll_fd[index].handle);
+		}
+		_poll_fd[index].original_handle = INVALID_HANDLE_VALUE;
+		_poll_fd[index].thread_id = 0;
+	}
+	free_overlapped(poll_fd[index].overlapped);
+	poll_fd[index] = INVALID_WINFD;
+}
+
+/*
+ * Release a pollable file descriptor.
+ *
+ * Note that the associated Windows handle is not closed by this call
+ */
+void usbi_free_fd(int fd)
+{
+	int index;
+
+	CHECK_INIT_POLLING;
+
+	index = _fd_to_index_and_lock(fd);
+	if (index < 0) {
+		return;
+	}
+	_free_index(index);
+	LeaveCriticalSection(&_poll_fd[index].mutex);
+}
+
+/*
+ * The functions below perform various conversions between fd, handle and OVERLAPPED
+ */
+struct winfd fd_to_winfd(int fd)
+{
+	int i;
+	struct winfd wfd;
+
+	CHECK_INIT_POLLING;
+
+	if (fd <= 0)
+		return INVALID_WINFD;
+
+	for (i=0; i<MAX_FDS; i++) {
+		if (poll_fd[i].fd == fd) {
+			EnterCriticalSection(&_poll_fd[i].mutex);
+			// fd might have been deleted before we got to critical
+			if (poll_fd[i].fd != fd) {
+				LeaveCriticalSection(&_poll_fd[i].mutex);
+				continue;
+			}
+			memcpy(&wfd, &poll_fd[i], sizeof(struct winfd));
+			LeaveCriticalSection(&_poll_fd[i].mutex);
+			return wfd;
+		}
+	}
+	return INVALID_WINFD;
+}
+
+struct winfd handle_to_winfd(HANDLE handle)
+{
+	int i;
+	struct winfd wfd;
+
+	CHECK_INIT_POLLING;
+
+	if ((handle == 0) || (handle == INVALID_HANDLE_VALUE))
+		return INVALID_WINFD;
+
+	for (i=0; i<MAX_FDS; i++) {
+		if (poll_fd[i].handle == handle) {
+			EnterCriticalSection(&_poll_fd[i].mutex);
+			// fd might have been deleted before we got to critical
+			if (poll_fd[i].handle != handle) {
+				LeaveCriticalSection(&_poll_fd[i].mutex);
+				continue;
+			}
+			memcpy(&wfd, &poll_fd[i], sizeof(struct winfd));
+			LeaveCriticalSection(&_poll_fd[i].mutex);
+			return wfd;
+		}
+	}
+	return INVALID_WINFD;
+}
+
+struct winfd overlapped_to_winfd(OVERLAPPED* overlapped)
+{
+	int i;
+	struct winfd wfd;
+
+	CHECK_INIT_POLLING;
+
+	if (overlapped == NULL)
+		return INVALID_WINFD;
+
+	for (i=0; i<MAX_FDS; i++) {
+		if (poll_fd[i].overlapped == overlapped) {
+			EnterCriticalSection(&_poll_fd[i].mutex);
+			// fd might have been deleted before we got to critical
+			if (poll_fd[i].overlapped != overlapped) {
+				LeaveCriticalSection(&_poll_fd[i].mutex);
+				continue;
+			}
+			memcpy(&wfd, &poll_fd[i], sizeof(struct winfd));
+			LeaveCriticalSection(&_poll_fd[i].mutex);
+			return wfd;
+		}
+	}
+	return INVALID_WINFD;
+}
+
+/*
+ * POSIX poll equivalent, using Windows OVERLAPPED
+ * Currently, this function only accepts one of POLLIN or POLLOUT per fd
+ * (but you can create multiple fds from the same handle for read and write)
+ */
+int usbi_poll(struct pollfd *fds, unsigned int nfds, int timeout)
+{
+	unsigned i;
+	int index, object_index, triggered;
+	HANDLE *handles_to_wait_on;
+	int *handle_to_index;
+	DWORD nb_handles_to_wait_on = 0;
+	DWORD ret;
+
+#if defined(DYNAMIC_FDS)
+	DWORD nb_extra_handles = 0;
+	unsigned j;
+
+	// To address the possibility of missing new fds between the time the new
+	// pollable fd set is assembled, and the ResetEvent() call below, an
+	// additional new_fd[] HANDLE table is used for any new fd that was created
+	// since the last call to poll (see below)
+	ResetEvent(fd_update);
+
+	// At this stage, any new fd creation will be detected through the fd_update
+	// event notification, and any previous creation that we may have missed
+	// will be picked up through the existing new_fd[] table.
+#endif
+
+	CHECK_INIT_POLLING;
+
+	triggered = 0;
+	handles_to_wait_on = malloc((nfds+1)*sizeof(HANDLE));	// +1 for fd_update
+	handle_to_index = malloc(nfds*sizeof(int));
+	if ((handles_to_wait_on == NULL) || (handle_to_index == NULL)) {
+		errno = ENOMEM;
+		triggered = -1;
+		goto poll_exit;
+	}
+
+	for (i = 0; i < nfds; ++i) {
+		fds[i].revents = 0;
+
+		// Only one of POLLIN or POLLOUT can be selected with this version of poll (not both)
+		if ((fds[i].events & ~POLLIN) && (!(fds[i].events & POLLOUT))) {
+			fds[i].revents |= POLLERR;
+			errno = EACCES;
+			usbi_warn(NULL, "unsupported set of events");
+			triggered = -1;
+			goto poll_exit;
+		}
+
+		index = _fd_to_index_and_lock(fds[i].fd);
+		poll_dbg("fd[%d]=%d: (overlapped=%p) got events %04X", i, poll_fd[index].fd, poll_fd[index].overlapped, fds[i].events);
+
+		if ( (index < 0) || (poll_fd[index].handle == INVALID_HANDLE_VALUE)
+		  || (poll_fd[index].handle == 0) || (poll_fd[index].overlapped == NULL)) {
+			fds[i].revents |= POLLNVAL | POLLERR;
+			errno = EBADF;
+			if (index >= 0) {
+				LeaveCriticalSection(&_poll_fd[index].mutex);
+			}
+			usbi_warn(NULL, "invalid fd");
+			triggered = -1;
+			goto poll_exit;
+		}
+
+		// IN or OUT must match our fd direction
+		if ((fds[i].events & POLLIN) && (poll_fd[index].rw != RW_READ)) {
+			fds[i].revents |= POLLNVAL | POLLERR;
+			errno = EBADF;
+			usbi_warn(NULL, "attempted POLLIN on fd without READ access");
+			LeaveCriticalSection(&_poll_fd[index].mutex);
+			triggered = -1;
+			goto poll_exit;
+		}
+
+		if ((fds[i].events & POLLOUT) && (poll_fd[index].rw != RW_WRITE)) {
+			fds[i].revents |= POLLNVAL | POLLERR;
+			errno = EBADF;
+			usbi_warn(NULL, "attempted POLLOUT on fd without WRITE access");
+			LeaveCriticalSection(&_poll_fd[index].mutex);
+			triggered = -1;
+			goto poll_exit;
+		}
+
+		// The following macro only works if overlapped I/O was reported pending
+		if ( (HasOverlappedIoCompleted(poll_fd[index].overlapped))
+		  || (HasOverlappedIoCompletedSync(poll_fd[index].overlapped)) ) {
+			poll_dbg("  completed");
+			// checks above should ensure this works:
+			fds[i].revents = fds[i].events;
+			triggered++;
+		} else {
+			handles_to_wait_on[nb_handles_to_wait_on] = poll_fd[index].overlapped->hEvent;
+			handle_to_index[nb_handles_to_wait_on] = i;
+#if defined(DYNAMIC_FDS)
+			// If this fd from the poll set is also part of the new_fd event handle table, remove it
+			usbi_mutex_lock(&new_fd_mutex);
+			for (j=0; j<nb_new_fds; j++) {
+				if (handles_to_wait_on[nb_handles_to_wait_on] == new_fd[j]) {
+					new_fd[j] = INVALID_HANDLE_VALUE;
+					break;
+				}
+			}
+			usbi_mutex_unlock(&new_fd_mutex);
+#endif
+			nb_handles_to_wait_on++;
+		}
+		LeaveCriticalSection(&_poll_fd[index].mutex);
+	}
+#if defined(DYNAMIC_FDS)
+	// At this stage, new_fd[] should only contain events from fds that
+	// have been added since the last call to poll, but are not (yet) part
+	// of the pollable fd set. Typically, these would be from fds that have
+	// been created between the construction of the fd set and the calling
+	// of poll.
+	// Event if we won't be able to return usable poll data on these events,
+	// make sure we monitor them to return an EINTR code
+	usbi_mutex_lock(&new_fd_mutex); // We could probably do without
+	for (i=0; i<nb_new_fds; i++) {
+		if (new_fd[i] != INVALID_HANDLE_VALUE) {
+			handles_to_wait_on[nb_handles_to_wait_on++] = new_fd[i];
+			nb_extra_handles++;
+		}
+	}
+	usbi_mutex_unlock(&new_fd_mutex);
+	poll_dbg("dynamic_fds: added %d extra handles", nb_extra_handles);
+#endif
+
+	// If nothing was triggered, wait on all fds that require it
+	if ((timeout != 0) && (triggered == 0) && (nb_handles_to_wait_on != 0)) {
+#if defined(DYNAMIC_FDS)
+		// Register for fd update notifications
+		handles_to_wait_on[nb_handles_to_wait_on++] = fd_update;
+		nb_extra_handles++;
+#endif
+		if (timeout < 0) {
+			poll_dbg("starting infinite wait for %d handles...", (int)nb_handles_to_wait_on);
+		} else {
+			poll_dbg("starting %d ms wait for %d handles...", timeout, (int)nb_handles_to_wait_on);
+		}
+		ret = WaitForMultipleObjects(nb_handles_to_wait_on, handles_to_wait_on,
+			FALSE, (timeout<0)?INFINITE:(DWORD)timeout);
+		object_index = ret-WAIT_OBJECT_0;
+		if ((object_index >= 0) && ((DWORD)object_index < nb_handles_to_wait_on)) {
+#if defined(DYNAMIC_FDS)
+			if ((DWORD)object_index >= (nb_handles_to_wait_on-nb_extra_handles)) {
+				// Detected fd update => flag a poll interruption
+				if ((DWORD)object_index == (nb_handles_to_wait_on-1))
+					poll_dbg("  dynamic_fds: fd_update event");
+				else
+					poll_dbg("  dynamic_fds: new fd I/O event");
+				errno = EINTR;
+				triggered = -1;
+				goto poll_exit;
+			}
+#endif
+			poll_dbg("  completed after wait");
+			i = handle_to_index[object_index];
+			index = _fd_to_index_and_lock(fds[i].fd);
+			fds[i].revents = fds[i].events;
+			triggered++;
+			if (index >= 0) {
+				LeaveCriticalSection(&_poll_fd[index].mutex);
+			}
+		} else if (ret == WAIT_TIMEOUT) {
+			poll_dbg("  timed out");
+			triggered = 0;	// 0 = timeout
+		} else {
+			errno = EIO;
+			triggered = -1;	// error
+		}
+	}
+
+poll_exit:
+	if (handles_to_wait_on != NULL) {
+		free(handles_to_wait_on);
+	}
+	if (handle_to_index != NULL) {
+		free(handle_to_index);
+	}
+#if defined(DYNAMIC_FDS)
+	usbi_mutex_lock(&new_fd_mutex);
+	nb_new_fds = 0;
+	usbi_mutex_unlock(&new_fd_mutex);
+#endif
+	return triggered;
+}
+
+/*
+ * close a fake pipe fd
+ */
+int usbi_close(int fd)
+{
+	int index;
+	int r = -1;
+
+	CHECK_INIT_POLLING;
+
+	index = _fd_to_index_and_lock(fd);
+
+	if (index < 0) {
+		errno = EBADF;
+	} else {
+		if (poll_fd[index].overlapped != NULL) {
+			// Must be a different event for each end of the pipe
+			CloseHandle(poll_fd[index].overlapped->hEvent);
+			free(poll_fd[index].overlapped);
+		}
+		if (CloseHandle(poll_fd[index].handle) == 0) {
+			errno = EIO;
+		} else {
+			r = 0;
+		}
+		poll_fd[index] = INVALID_WINFD;
+		LeaveCriticalSection(&_poll_fd[index].mutex);
+	}
+	return r;
+}
+
+/*
+ * synchronous write for fake "pipe" signaling
+ */
+ssize_t usbi_write(int fd, const void *buf, size_t count)
+{
+	int index;
+
+	CHECK_INIT_POLLING;
+
+	if (count != sizeof(unsigned char)) {
+		usbi_err(NULL, "this function should only used for signaling");
+		return -1;
+	}
+
+	index = _fd_to_index_and_lock(fd);
+
+	if ( (index < 0) || (poll_fd[index].overlapped == NULL) ) {
+		errno = EBADF;
+		if (index >= 0) {
+			LeaveCriticalSection(&_poll_fd[index].mutex);
+		}
+		return -1;
+	}
+
+	poll_dbg("set pipe event (fd = %d, thread = %08X)", index, GetCurrentThreadId());
+	SetEvent(poll_fd[index].overlapped->hEvent);
+	poll_fd[index].overlapped->Internal = STATUS_WAIT_0;
+	// If two threads write on the pipe at the same time, we need to
+	// process two separate reads => use the overlapped as a counter
+	poll_fd[index].overlapped->InternalHigh++;
+
+	LeaveCriticalSection(&_poll_fd[index].mutex);
+	return sizeof(unsigned char);
+}
+
+/*
+ * synchronous read for fake "pipe" signaling
+ */
+ssize_t usbi_read(int fd, void *buf, size_t count)
+{
+	int index;
+	ssize_t r = -1;
+
+	CHECK_INIT_POLLING;
+
+	if (count != sizeof(unsigned char)) {
+		usbi_err(NULL, "this function should only used for signaling");
+		return -1;
+	}
+
+	index = _fd_to_index_and_lock(fd);
+
+	if (index < 0) {
+		errno = EBADF;
+		return -1;
+	}
+
+	if (WaitForSingleObject(poll_fd[index].overlapped->hEvent, INFINITE) != WAIT_OBJECT_0) {
+		usbi_warn(NULL, "waiting for event failed: %d", (int)GetLastError());
+		errno = EIO;
+		goto out;
+	}
+
+	poll_dbg("clr pipe event (fd = %d, thread = %08X)", index, GetCurrentThreadId());
+	poll_fd[index].overlapped->InternalHigh--;
+	// Don't reset unless we don't have any more events to process
+	if (poll_fd[index].overlapped->InternalHigh <= 0) {
+		ResetEvent(poll_fd[index].overlapped->hEvent);
+		poll_fd[index].overlapped->Internal = STATUS_PENDING;
+	}
+
+	r = sizeof(unsigned char);
+
+out:
+	LeaveCriticalSection(&_poll_fd[index].mutex);
+	return r;
+}
diff --git a/include/libusb-1.0/os/poll_windows.h b/include/libusb-1.0/os/poll_windows.h
new file mode 100644
index 0000000..a9e3e90
--- /dev/null
+++ b/include/libusb-1.0/os/poll_windows.h
@@ -0,0 +1,120 @@
+/*
+ * Windows compat: POSIX compatibility wrapper
+ * Copyright (C) 2009-2010 Pete Batard <pbatard@gmail.com>
+ * With contributions from Michael Plante, Orin Eman et al.
+ * Parts of poll implementation from libusb-win32, by Stephan Meyer et al.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ */
+#pragma once
+
+#if defined(_MSC_VER)
+// disable /W4 MSVC warnings that are benign
+#pragma warning(disable:4127) // conditional expression is constant
+#endif
+
+// Uncomment to have poll return with EINTR as soon as a new transfer (fd) is added
+// This should result in a LIBUSB_ERROR_INTERRUPTED being returned by libusb calls,
+// which should give the app an opportunity to resubmit a new fd set.
+//#define DYNAMIC_FDS
+
+// Handle synchronous completion through the overlapped structure
+#if !defined(STATUS_REPARSE)	// reuse the REPARSE status code
+#define STATUS_REPARSE ((LONG)0x00000104L)
+#endif
+#define STATUS_COMPLETED_SYNCHRONOUSLY	STATUS_REPARSE
+#define HasOverlappedIoCompletedSync(lpOverlapped)	(((DWORD)(lpOverlapped)->Internal) == STATUS_COMPLETED_SYNCHRONOUSLY)
+
+enum windows_version {
+	WINDOWS_UNSUPPORTED,
+	WINDOWS_XP,
+	WINDOWS_2003,	// also includes XP 64
+	WINDOWS_VISTA_AND_LATER,
+};
+extern enum windows_version windows_version;
+
+#define MAX_FDS     256
+
+#define POLLIN      0x0001    /* There is data to read */
+#define POLLPRI     0x0002    /* There is urgent data to read */
+#define POLLOUT     0x0004    /* Writing now will not block */
+#define POLLERR     0x0008    /* Error condition */
+#define POLLHUP     0x0010    /* Hung up */
+#define POLLNVAL    0x0020    /* Invalid request: fd not open */
+
+struct pollfd {
+    int fd;           /* file descriptor */
+    short events;     /* requested events */
+    short revents;    /* returned events */
+};
+
+typedef unsigned int nfds_t;
+
+// access modes
+enum rw_type {
+	RW_NONE,
+	RW_READ,
+	RW_WRITE,
+};
+
+// fd struct that can be used for polling on Windows
+struct winfd {
+	int fd;				            // what's exposed to libusb core
+	HANDLE handle;                  // what we need to attach overlapped to the I/O op, so we can poll it
+	OVERLAPPED* overlapped;         // what will report our I/O status
+	enum rw_type rw;                // I/O transfer direction: read *XOR* write (NOT BOTH)
+};
+extern const struct winfd INVALID_WINFD;
+
+int usbi_pipe(int pipefd[2]);
+int usbi_poll(struct pollfd *fds, unsigned int nfds, int timeout);
+ssize_t usbi_write(int fd, const void *buf, size_t count);
+ssize_t usbi_read(int fd, void *buf, size_t count);
+int usbi_close(int fd);
+
+void init_polling(void);
+void exit_polling(void);
+struct winfd usbi_create_fd(HANDLE handle, int access_mode);
+void usbi_free_fd(int fd);
+struct winfd fd_to_winfd(int fd);
+struct winfd handle_to_winfd(HANDLE handle);
+struct winfd overlapped_to_winfd(OVERLAPPED* overlapped);
+
+/*
+ * Timeval operations
+ */
+#if defined(DDKBUILD)
+#include <winsock.h>	// defines timeval functions on DDK
+#endif
+
+#if !defined(TIMESPEC_TO_TIMEVAL)
+#define TIMESPEC_TO_TIMEVAL(tv, ts) {                   \
+	(tv)->tv_sec = (long)(ts)->tv_sec;                  \
+	(tv)->tv_usec = (long)(ts)->tv_nsec / 1000;         \
+}
+#endif
+#if !defined(timersub)
+#define timersub(a, b, result)                          \
+do {                                                    \
+	(result)->tv_sec = (a)->tv_sec - (b)->tv_sec;       \
+	(result)->tv_usec = (a)->tv_usec - (b)->tv_usec;    \
+	if ((result)->tv_usec < 0) {                        \
+		--(result)->tv_sec;                             \
+		(result)->tv_usec += 1000000;                   \
+	}                                                   \
+} while (0)
+#endif
+
diff --git a/include/libusb-1.0/os/threads_posix.h b/include/libusb-1.0/os/threads_posix.h
new file mode 100644
index 0000000..dc558d4
--- /dev/null
+++ b/include/libusb-1.0/os/threads_posix.h
@@ -0,0 +1,46 @@
+/*
+ * libusb synchronization using POSIX Threads
+ *
+ * Copyright (C) 2010 Peter Stuge <peter@stuge.se>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef __LIBUSB_THREADS_POSIX_H__
+#define __LIBUSB_THREADS_POSIX_H__
+
+#include <pthread.h>
+
+#define usbi_mutex_static_t		pthread_mutex_t
+#define USBI_MUTEX_INITIALIZER		PTHREAD_MUTEX_INITIALIZER
+#define usbi_mutex_static_lock		pthread_mutex_lock
+#define usbi_mutex_static_unlock	pthread_mutex_unlock
+
+#define usbi_mutex_t			pthread_mutex_t
+#define usbi_mutex_init			pthread_mutex_init
+#define usbi_mutex_lock			pthread_mutex_lock
+#define usbi_mutex_unlock		pthread_mutex_unlock
+#define usbi_mutex_trylock		pthread_mutex_trylock
+#define usbi_mutex_destroy		pthread_mutex_destroy
+
+#define usbi_cond_t			pthread_cond_t
+#define usbi_cond_init			pthread_cond_init
+#define usbi_cond_wait			pthread_cond_wait
+#define usbi_cond_timedwait		pthread_cond_timedwait
+#define usbi_cond_broadcast		pthread_cond_broadcast
+#define usbi_cond_destroy		pthread_cond_destroy
+#define usbi_cond_signal	pthread_cond_signal
+
+#endif /* __LIBUSB_THREADS_POSIX_H__ */
diff --git a/include/libusb-1.0/os/threads_windows.c b/include/libusb-1.0/os/threads_windows.c
new file mode 100644
index 0000000..8a29920
--- /dev/null
+++ b/include/libusb-1.0/os/threads_windows.c
@@ -0,0 +1,208 @@
+/*
+ * libusb synchronization on Microsoft Windows
+ *
+ * Copyright (C) 2010 Michael Plante <michael.plante@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <config.h>
+#include <objbase.h>
+#include <errno.h>
+#include <stdarg.h>
+
+#include "libusbi.h"
+
+
+int usbi_mutex_init(usbi_mutex_t *mutex,
+					const usbi_mutexattr_t *attr) {
+	if(! mutex) return ((errno=EINVAL));
+	*mutex = CreateMutex(NULL, FALSE, NULL);
+	if(!*mutex) return ((errno=ENOMEM));
+	return 0;
+}
+int usbi_mutex_destroy(usbi_mutex_t *mutex) {
+	// It is not clear if CloseHandle failure is due to failure to unlock.
+	//   If so, this should be errno=EBUSY.
+	if(!mutex || !CloseHandle(*mutex)) return ((errno=EINVAL));
+	*mutex = NULL;
+	return 0;
+}
+int usbi_mutex_trylock(usbi_mutex_t *mutex) {
+	DWORD result;
+	if(!mutex) return ((errno=EINVAL));
+	result = WaitForSingleObject(*mutex, 0);
+	if(result == WAIT_OBJECT_0 || result == WAIT_ABANDONED)
+		return 0; // acquired (ToDo: check that abandoned is ok)
+	if(result == WAIT_TIMEOUT)
+		return ((errno=EBUSY));
+	return ((errno=EINVAL)); // don't know how this would happen
+							 //   so don't know proper errno
+}
+int usbi_mutex_lock(usbi_mutex_t *mutex) {
+	DWORD result;
+	if(!mutex) return ((errno=EINVAL));
+	result = WaitForSingleObject(*mutex, INFINITE);
+	if(result == WAIT_OBJECT_0 || result == WAIT_ABANDONED)
+		return 0; // acquired (ToDo: check that abandoned is ok)
+	return ((errno=EINVAL)); // don't know how this would happen
+							 //   so don't know proper errno
+}
+int usbi_mutex_unlock(usbi_mutex_t *mutex) {
+	if(!mutex)                return ((errno=EINVAL));
+	if(!ReleaseMutex(*mutex)) return ((errno=EPERM ));
+	return 0;
+}
+
+int usbi_mutex_static_lock(usbi_mutex_static_t *mutex) {
+	if(!mutex)               return ((errno=EINVAL));
+	while (InterlockedExchange((LONG *)mutex, 1) == 1) {
+		SleepEx(0, TRUE);
+	}
+	return 0;
+}
+int usbi_mutex_static_unlock(usbi_mutex_static_t *mutex) {
+	if(!mutex)               return ((errno=EINVAL));
+	*mutex = 0;
+	return 0;
+}
+
+
+
+int usbi_cond_init(usbi_cond_t *cond,
+				   const usbi_condattr_t *attr) {
+	if(!cond)           return ((errno=EINVAL));
+	list_init(&cond->waiters    );
+	list_init(&cond->not_waiting);
+	return 0;
+}
+int usbi_cond_destroy(usbi_cond_t *cond) {
+	// This assumes no one is using this anymore.  The check MAY NOT BE safe.
+	struct usbi_cond_perthread *pos, *prev_pos = NULL;
+	if(!cond) return ((errno=EINVAL));
+	if(!list_empty(&cond->waiters)) return ((errno=EBUSY )); // (!see above!)
+	list_for_each_entry(pos, &cond->not_waiting, list, struct usbi_cond_perthread) {
+		free(prev_pos);
+		list_del(&pos->list);
+		prev_pos = pos;
+	}
+	free(prev_pos);
+	prev_pos = pos = NULL;
+
+	return 0;
+}
+
+int usbi_cond_broadcast(usbi_cond_t *cond) {
+	// Assumes mutex is locked; this is not in keeping with POSIX spec, but
+	//   libusb does this anyway, so we simplify by not adding more sync
+	//   primitives to the CV definition!
+	int fail = 0;
+	struct usbi_cond_perthread *pos;
+	if(!cond)                      return ((errno=EINVAL));
+	list_for_each_entry(pos, &cond->waiters, list, struct usbi_cond_perthread) {
+		if(!SetEvent(pos->event))
+			fail = 1;
+	}
+	// The wait function will remove its respective item from the list.
+	return fail ? ((errno=EINVAL)) : 0;
+}
+int usbi_cond_signal(usbi_cond_t *cond) {
+	// Assumes mutex is locked; this is not in keeping with POSIX spec, but
+	//   libusb does this anyway, so we simplify by not adding more sync
+	//   primitives to the CV definition!
+	struct usbi_cond_perthread *pos;
+	if(!cond)                      return ((errno=EINVAL));
+	if(list_empty(&cond->waiters)) return 0; // no one to wakeup.
+	pos = list_entry(&cond->waiters.next, struct usbi_cond_perthread, list);
+	// The wait function will remove its respective item from the list.
+	return SetEvent(pos->event) ? 0 : ((errno=EINVAL));
+}
+static int __inline usbi_cond_intwait(usbi_cond_t *cond,
+									  usbi_mutex_t *mutex,
+									  DWORD timeout_ms) {
+	struct usbi_cond_perthread *pos;
+	int found = 0, r;
+	DWORD r2,tid = GetCurrentThreadId();
+	if(!cond || !mutex) return ((errno=EINVAL));
+	list_for_each_entry(pos, &cond->not_waiting, list, struct usbi_cond_perthread) {
+		if(tid == pos->tid) {
+			found = 1;
+			break;
+		}
+	}
+	if(!found) {
+		pos      = malloc(sizeof(struct usbi_cond_perthread));
+		if(!pos) return ((errno=ENOMEM)); // This errno is not POSIX-allowed.
+		pos->tid = tid;
+		pos->event = CreateEvent(NULL, FALSE, FALSE, NULL); // auto-reset.
+		if(!pos->event) {
+			free(pos);
+			return      ((errno=ENOMEM));
+		}
+		list_add(&pos->list, &cond->not_waiting);
+	}
+
+	list_del(&pos->list); // remove from not_waiting list.
+	list_add(&pos->list, &cond->waiters);
+
+	r  = usbi_mutex_unlock(mutex);
+	if(r) return r;
+	r2 = WaitForSingleObject(pos->event, timeout_ms);
+	r  = usbi_mutex_lock(mutex);
+	if(r) return r;
+
+	list_del(&pos->list);
+	list_add(&pos->list, &cond->not_waiting);
+
+	if(r2 == WAIT_TIMEOUT) return ((errno=ETIMEDOUT));
+
+	return 0;
+}
+// N.B.: usbi_cond_*wait() can also return ENOMEM, even though pthread_cond_*wait cannot!
+int usbi_cond_wait(usbi_cond_t *cond, usbi_mutex_t *mutex) {
+	return usbi_cond_intwait(cond, mutex, INFINITE);
+}
+int usbi_cond_timedwait(usbi_cond_t *cond,
+						usbi_mutex_t *mutex,
+						const struct timespec *abstime) {
+	FILETIME filetime;
+	ULARGE_INTEGER rtime;
+	struct timeval targ_time, cur_time, delta_time;
+	struct timespec cur_time_ns;
+	DWORD millis;
+	extern const uint64_t epoch_time;
+
+	GetSystemTimeAsFileTime(&filetime);
+	rtime.LowPart   = filetime.dwLowDateTime;
+	rtime.HighPart  = filetime.dwHighDateTime;
+	rtime.QuadPart -= epoch_time;
+	cur_time_ns.tv_sec = (long)(rtime.QuadPart / 10000000);
+	cur_time_ns.tv_nsec = (long)((rtime.QuadPart % 10000000)*100);
+	TIMESPEC_TO_TIMEVAL(&cur_time, &cur_time_ns);
+
+	TIMESPEC_TO_TIMEVAL(&targ_time, abstime);
+	timersub(&targ_time, &cur_time, &delta_time);
+	if(delta_time.tv_sec < 0) // abstime already passed?
+		millis = 0;
+	else {
+		millis  = delta_time.tv_usec/1000;
+		millis += delta_time.tv_sec *1000;
+		if (delta_time.tv_usec % 1000) // round up to next millisecond
+			millis++;
+	}
+
+	return usbi_cond_intwait(cond, mutex, millis);
+}
+
diff --git a/include/libusb-1.0/os/threads_windows.h b/include/libusb-1.0/os/threads_windows.h
new file mode 100644
index 0000000..2cd1867
--- /dev/null
+++ b/include/libusb-1.0/os/threads_windows.h
@@ -0,0 +1,84 @@
+/*
+ * libusb synchronization on Microsoft Windows
+ *
+ * Copyright (C) 2010 Michael Plante <michael.plante@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef __LIBUSB_THREADS_WINDOWS_H__
+#define __LIBUSB_THREADS_WINDOWS_H__
+
+#define usbi_mutex_static_t     volatile LONG
+#define USBI_MUTEX_INITIALIZER  0
+
+#define usbi_mutex_t            HANDLE
+
+struct usbi_cond_perthread {
+	struct list_head list;
+	DWORD            tid;
+	HANDLE           event;
+};
+struct usbi_cond_t_ {
+	// Every time a thread touches the CV, it winds up in one of these lists.
+	//   It stays there until the CV is destroyed, even if the thread
+	//   terminates.
+	struct list_head waiters;
+	struct list_head not_waiting;
+};
+typedef struct usbi_cond_t_ usbi_cond_t;
+
+// We *were* getting timespec from pthread.h:
+#if (!defined(HAVE_STRUCT_TIMESPEC) && !defined(_TIMESPEC_DEFINED))
+#define HAVE_STRUCT_TIMESPEC 1
+#define _TIMESPEC_DEFINED 1
+struct timespec {
+		long tv_sec;
+		long tv_nsec;
+};
+#endif /* HAVE_STRUCT_TIMESPEC | _TIMESPEC_DEFINED */
+
+// We *were* getting ETIMEDOUT from pthread.h:
+#ifndef ETIMEDOUT
+#  define ETIMEDOUT 10060     /* This is the value in winsock.h. */
+#endif
+
+#define usbi_mutexattr_t void
+#define usbi_condattr_t  void
+
+
+int usbi_mutex_static_lock(usbi_mutex_static_t *mutex);
+int usbi_mutex_static_unlock(usbi_mutex_static_t *mutex);
+
+
+int usbi_mutex_init(usbi_mutex_t *mutex,
+					const usbi_mutexattr_t *attr);
+int usbi_mutex_lock(usbi_mutex_t *mutex);
+int usbi_mutex_unlock(usbi_mutex_t *mutex);
+int usbi_mutex_trylock(usbi_mutex_t *mutex);
+int usbi_mutex_destroy(usbi_mutex_t *mutex);
+
+int usbi_cond_init(usbi_cond_t *cond,
+				   const usbi_condattr_t *attr);
+int usbi_cond_destroy(usbi_cond_t *cond);
+int usbi_cond_wait(usbi_cond_t *cond, usbi_mutex_t *mutex);
+int usbi_cond_timedwait(usbi_cond_t *cond,
+						usbi_mutex_t *mutex,
+						const struct timespec *abstime);
+int usbi_cond_broadcast(usbi_cond_t *cond);
+int usbi_cond_signal(usbi_cond_t *cond);
+
+#endif /* __LIBUSB_THREADS_WINDOWS_H__ */
+
diff --git a/include/libusb-1.0/os/windows_usb.c b/include/libusb-1.0/os/windows_usb.c
new file mode 100644
index 0000000..e37932a
--- /dev/null
+++ b/include/libusb-1.0/os/windows_usb.c
@@ -0,0 +1,4185 @@
+/*
+ * windows backend for libusb 1.0
+ * Copyright (c) 2009-2010 Pete Batard <pbatard@gmail.com>
+ * With contributions from Michael Plante, Orin Eman et al.
+ * Parts of this code adapted from libusb-win32-v1 by Stephan Meyer
+ * HID Reports IOCTLs inspired from HIDAPI by Alan Ott, Signal 11 Software
+ * Major code testing contribution by Xiaofan Chen
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+// COMPILATION OPTIONS:
+// - Should libusb automatically claim (and release) the interfaces it requires?
+#define AUTO_CLAIM
+// - Forces instant overlapped completion on timeouts: can prevents extensive
+//   wait in poll, after a timeout, but might affect subsequent API calls.
+//   ***USE AT YOUR OWN RISKS***
+//#define FORCE_INSTANT_TIMEOUTS
+
+#include <config.h>
+#include <windows.h>
+#include <setupapi.h>
+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <process.h>
+#include <stdio.h>
+#include <inttypes.h>
+#include <objbase.h>  // for string to GUID conv. requires libole32.a
+#include <winioctl.h>
+
+#include <libusbi.h>
+#include "poll_windows.h"
+#include "windows_usb.h"
+
+// The following prevents "banned API" errors when using the MS's WDK OACR/Prefast
+#if defined(_PREFAST_)
+#pragma warning(disable:28719)
+#endif
+
+// The 2 macros below are used in conjunction with safe loops.
+#define LOOP_CHECK(fcall) { r=fcall; if (r != LIBUSB_SUCCESS) continue; }
+#define LOOP_BREAK(err) { r=err; continue; }
+
+extern void usbi_fd_notification(struct libusb_context *ctx);
+
+// Helper prototypes
+static int windows_get_active_config_descriptor(struct libusb_device *dev, unsigned char *buffer, size_t len, int *host_endian);
+static int windows_clock_gettime(int clk_id, struct timespec *tp);
+unsigned __stdcall windows_clock_gettime_threaded(void* param);
+// WinUSB API prototypes
+static int winusb_init(struct libusb_context *ctx);
+static int winusb_exit(void);
+static int winusb_open(struct libusb_device_handle *dev_handle);
+static void winusb_close(struct libusb_device_handle *dev_handle);
+static int winusb_claim_interface(struct libusb_device_handle *dev_handle, int iface);
+static int winusb_release_interface(struct libusb_device_handle *dev_handle, int iface);
+static int winusb_submit_control_transfer(struct usbi_transfer *itransfer);
+static int winusb_set_interface_altsetting(struct libusb_device_handle *dev_handle, int iface, int altsetting);
+static int winusb_submit_bulk_transfer(struct usbi_transfer *itransfer);
+static int winusb_clear_halt(struct libusb_device_handle *dev_handle, unsigned char endpoint);
+static int winusb_abort_transfers(struct usbi_transfer *itransfer);
+static int winusb_abort_control(struct usbi_transfer *itransfer);
+static int winusb_reset_device(struct libusb_device_handle *dev_handle);
+static int winusb_copy_transfer_data(struct usbi_transfer *itransfer, uint32_t io_size);
+// HID API prototypes
+static int hid_init(struct libusb_context *ctx);
+static int hid_exit(void);
+static int hid_open(struct libusb_device_handle *dev_handle);
+static void hid_close(struct libusb_device_handle *dev_handle);
+static int hid_claim_interface(struct libusb_device_handle *dev_handle, int iface);
+static int hid_release_interface(struct libusb_device_handle *dev_handle, int iface);
+static int hid_set_interface_altsetting(struct libusb_device_handle *dev_handle, int iface, int altsetting);
+static int hid_submit_control_transfer(struct usbi_transfer *itransfer);
+static int hid_submit_bulk_transfer(struct usbi_transfer *itransfer);
+static int hid_clear_halt(struct libusb_device_handle *dev_handle, unsigned char endpoint);
+static int hid_abort_transfers(struct usbi_transfer *itransfer);
+static int hid_reset_device(struct libusb_device_handle *dev_handle);
+static int hid_copy_transfer_data(struct usbi_transfer *itransfer, uint32_t io_size);
+// Composite API prototypes
+static int composite_init(struct libusb_context *ctx);
+static int composite_exit(void);
+static int composite_open(struct libusb_device_handle *dev_handle);
+static void composite_close(struct libusb_device_handle *dev_handle);
+static int composite_claim_interface(struct libusb_device_handle *dev_handle, int iface);
+static int composite_set_interface_altsetting(struct libusb_device_handle *dev_handle, int iface, int altsetting);
+static int composite_release_interface(struct libusb_device_handle *dev_handle, int iface);
+static int composite_submit_control_transfer(struct usbi_transfer *itransfer);
+static int composite_submit_bulk_transfer(struct usbi_transfer *itransfer);
+static int composite_submit_iso_transfer(struct usbi_transfer *itransfer);
+static int composite_clear_halt(struct libusb_device_handle *dev_handle, unsigned char endpoint);
+static int composite_abort_transfers(struct usbi_transfer *itransfer);
+static int composite_abort_control(struct usbi_transfer *itransfer);
+static int composite_reset_device(struct libusb_device_handle *dev_handle);
+static int composite_copy_transfer_data(struct usbi_transfer *itransfer, uint32_t io_size);
+
+
+// Global variables
+struct windows_hcd_priv* hcd_root = NULL;
+uint64_t hires_frequency, hires_ticks_to_ps;
+const uint64_t epoch_time = UINT64_C(116444736000000000);	// 1970.01.01 00:00:000 in MS Filetime
+enum windows_version windows_version = WINDOWS_UNSUPPORTED;
+// Concurrency
+static int concurrent_usage = -1;
+#if defined(AUTO_CLAIM)
+usbi_mutex_t autoclaim_lock;
+#endif
+// Timer thread
+// NB: index 0 is for monotonic and 1 is for the thread exit event
+HANDLE timer_thread = NULL;
+HANDLE timer_mutex = NULL;
+struct timespec timer_tp;
+volatile LONG request_count[2] = {0, 1};	// last one must be > 0
+HANDLE timer_request[2] = { NULL, NULL };
+HANDLE timer_response = NULL;
+// API globals
+bool api_winusb_available = false;
+#define CHECK_WINUSB_AVAILABLE do { if (!api_winusb_available) return LIBUSB_ERROR_ACCESS; } while (0)
+bool api_hid_available = false;
+#define CHECK_HID_AVAILABLE do { if (!api_hid_available) return LIBUSB_ERROR_ACCESS; } while (0)
+
+
+/*
+ * Converts a WCHAR string to UTF8 (allocate returned string)
+ * Returns NULL on error
+ */
+static char* wchar_to_utf8(LPCWSTR wstr)
+{
+	int size;
+	char* str;
+
+	// Find out the size we need to allocate for our converted string
+	size = wchar_to_utf8_ms(wstr, NULL, 0);
+	if (size <= 1)	// An empty string would be size 1
+		return NULL;
+
+	if ((str = malloc(size)) == NULL)
+		return NULL;
+
+	if (wchar_to_utf8_ms(wstr, str, size) != size) {
+		safe_free(str);
+		return NULL;
+	}
+
+	return str;
+}
+
+static inline BOOLEAN guid_eq(const GUID *guid1, const GUID *guid2) {
+	if ((guid1 != NULL) && (guid2 != NULL)) {
+		return (memcmp(guid1, guid2, sizeof(GUID)) == 0);
+	}
+	return false;
+}
+
+#if 0
+static char* guid_to_string(const GUID guid)
+{
+	static char guid_string[MAX_GUID_STRING_LENGTH];
+
+	sprintf(guid_string, "{%08X-%04X-%04X-%02X%02X-%02X%02X%02X%02X%02X%02X}",
+		(unsigned int)guid.Data1, guid.Data2, guid.Data3,
+		guid.Data4[0], guid.Data4[1], guid.Data4[2], guid.Data4[3],
+		guid.Data4[4], guid.Data4[5], guid.Data4[6], guid.Data4[7]);
+	return guid_string;
+}
+#endif
+
+/*
+ * Converts a windows error to human readable string
+ * uses retval as errorcode, or, if 0, use GetLastError()
+ */
+static char *windows_error_str(uint32_t retval)
+{
+static char err_string[ERR_BUFFER_SIZE];
+
+	DWORD size;
+	size_t i;
+	uint32_t error_code, format_error;
+
+	error_code = retval?retval:GetLastError();
+
+	safe_sprintf(err_string, ERR_BUFFER_SIZE, "[%d] ", error_code);
+
+	size = FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM, NULL, error_code,
+		MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPTSTR) &err_string[safe_strlen(err_string)],
+		ERR_BUFFER_SIZE - (DWORD)safe_strlen(err_string), NULL);
+	if (size == 0) {
+		format_error = GetLastError();
+		if (format_error)
+			safe_sprintf(err_string, ERR_BUFFER_SIZE,
+				"Windows error code %u (FormatMessage error code %u)", error_code, format_error);
+		else
+			safe_sprintf(err_string, ERR_BUFFER_SIZE, "Unknown error code %u", error_code);
+	} else {
+		// Remove CR/LF terminators
+		for (i=safe_strlen(err_string)-1; ((err_string[i]==0x0A) || (err_string[i]==0x0D)); i--) {
+			err_string[i] = 0;
+		}
+	}
+	return err_string;
+}
+
+/*
+ * Sanitize Microsoft's paths: convert to uppercase, add prefix and fix backslashes.
+ * Return an allocated sanitized string or NULL on error.
+ */
+static char* sanitize_path(const char* path)
+{
+	const char root_prefix[] = "\\\\.\\";
+	size_t j, size, root_size;
+	char* ret_path = NULL;
+	size_t add_root = 0;
+
+	if (path == NULL)
+		return NULL;
+
+	size = safe_strlen(path)+1;
+	root_size = sizeof(root_prefix)-1;
+
+	// Microsoft indiscriminatly uses '\\?\', '\\.\', '##?#" or "##.#" for root prefixes.
+	if (!((size > 3) && (((path[0] == '\\') && (path[1] == '\\') && (path[3] == '\\')) ||
+		((path[0] == '#') && (path[1] == '#') && (path[3] == '#'))))) {
+		add_root = root_size;
+		size += add_root;
+	}
+
+	if ((ret_path = (char*)calloc(size, 1)) == NULL)
+		return NULL;
+
+	safe_strcpy(&ret_path[add_root], size-add_root, path);
+
+	// Ensure consistancy with root prefix
+	for (j=0; j<root_size; j++)
+		ret_path[j] = root_prefix[j];
+
+	// Same goes for '\' and '#' after the root prefix. Ensure '#' is used
+	for(j=root_size; j<size; j++) {
+		ret_path[j] = (char)toupper((int)ret_path[j]);	// Fix case too
+		if (ret_path[j] == '\\')
+			ret_path[j] = '#';
+	}
+
+	return ret_path;
+}
+
+/*
+ * Cfgmgr32 API functions
+ */
+static int Cfgmgr32_init(void)
+{
+	DLL_LOAD(Cfgmgr32.dll, CM_Get_Parent, TRUE);
+	DLL_LOAD(Cfgmgr32.dll, CM_Get_Child, TRUE);
+	DLL_LOAD(Cfgmgr32.dll, CM_Get_Sibling, TRUE);
+	DLL_LOAD(Cfgmgr32.dll, CM_Get_Device_IDA, TRUE);
+	DLL_LOAD(Cfgmgr32.dll, CM_Get_Device_IDW, TRUE);
+
+	return LIBUSB_SUCCESS;
+}
+
+/*
+ * enumerate interfaces for a specific GUID
+ *
+ * Parameters:
+ * dev_info: a pointer to a dev_info list
+ * dev_info_data: a pointer to an SP_DEVINFO_DATA to be filled (or NULL if not needed)
+ * guid: the GUID for which to retrieve interface details
+ * index: zero based index of the interface in the device info list
+ *
+ * Note: it is the responsibility of the caller to free the DEVICE_INTERFACE_DETAIL_DATA
+ * structure returned and call this function repeatedly using the same guid (with an
+ * incremented index starting at zero) until all interfaces have been returned.
+ */
+SP_DEVICE_INTERFACE_DETAIL_DATA *get_interface_details(struct libusb_context *ctx,
+	HDEVINFO *dev_info, SP_DEVINFO_DATA *dev_info_data, GUID guid, unsigned index)
+{
+	SP_DEVICE_INTERFACE_DATA dev_interface_data;
+	SP_DEVICE_INTERFACE_DETAIL_DATA *dev_interface_details = NULL;
+	DWORD size;
+
+	if (index <= 0) {
+		*dev_info = SetupDiGetClassDevs(&guid, NULL, NULL, DIGCF_PRESENT|DIGCF_DEVICEINTERFACE);
+	}
+	if (*dev_info == INVALID_HANDLE_VALUE) {
+		return NULL;
+	}
+
+	if (dev_info_data != NULL) {
+		dev_info_data->cbSize = sizeof(SP_DEVINFO_DATA);
+		if (!SetupDiEnumDeviceInfo(*dev_info, index, dev_info_data)) {
+			if (GetLastError() != ERROR_NO_MORE_ITEMS) {
+				usbi_err(ctx, "Could not obtain device info data for index %u: %s",
+					index, windows_error_str(0));
+			}
+			SetupDiDestroyDeviceInfoList(*dev_info);
+			*dev_info = INVALID_HANDLE_VALUE;
+			return NULL;
+		}
+	}
+
+	dev_interface_data.cbSize = sizeof(SP_DEVICE_INTERFACE_DATA);
+	if (!SetupDiEnumDeviceInterfaces(*dev_info, NULL, &guid, index, &dev_interface_data)) {
+		if (GetLastError() != ERROR_NO_MORE_ITEMS) {
+			usbi_err(ctx, "Could not obtain interface data for index %u: %s",
+				index, windows_error_str(0));
+		}
+		SetupDiDestroyDeviceInfoList(*dev_info);
+		*dev_info = INVALID_HANDLE_VALUE;
+		return NULL;
+	}
+
+	// Read interface data (dummy + actual) to access the device path
+	if (!SetupDiGetDeviceInterfaceDetail(*dev_info, &dev_interface_data, NULL, 0, &size, NULL)) {
+		// The dummy call should fail with ERROR_INSUFFICIENT_BUFFER
+		if (GetLastError() != ERROR_INSUFFICIENT_BUFFER) {
+			usbi_err(ctx, "could not access interface data (dummy) for index %u: %s",
+				index, windows_error_str(0));
+			goto err_exit;
+		}
+	}
+	else {
+		usbi_err(ctx, "program assertion failed - http://msdn.microsoft.com/en-us/library/ms792901.aspx is wrong.");
+		goto err_exit;
+	}
+
+	if ((dev_interface_details = malloc(size)) == NULL) {
+		usbi_err(ctx, "could not allocate interface data for index %u.", index);
+		goto err_exit;
+	}
+
+	dev_interface_details->cbSize = sizeof(SP_DEVICE_INTERFACE_DETAIL_DATA);
+	if (!SetupDiGetDeviceInterfaceDetail(*dev_info, &dev_interface_data,
+		dev_interface_details, size, &size, NULL)) {
+		usbi_err(ctx, "could not access interface data (actual) for index %u: %s",
+			index, windows_error_str(0));
+	}
+
+	return dev_interface_details;
+
+err_exit:
+	SetupDiDestroyDeviceInfoList(*dev_info);
+	*dev_info = INVALID_HANDLE_VALUE;
+	return NULL;
+}
+
+/*
+ * Populate the endpoints addresses of the device_priv interface helper structs
+ */
+static int windows_assign_endpoints(struct libusb_device *dev, int iface, int altsetting)
+{
+	int i, r;
+	struct windows_device_priv *priv = __device_priv(dev);
+	struct libusb_config_descriptor *conf_desc;
+	const struct libusb_interface_descriptor *if_desc;
+
+	r = libusb_get_config_descriptor(dev, 0, &conf_desc);
+	if (r != LIBUSB_SUCCESS) {
+		usbi_warn(NULL, "could not read config descriptor: error %d", r);
+		return r;
+	}
+
+	if_desc = &conf_desc->interface[iface].altsetting[altsetting];
+	safe_free(priv->usb_interface[iface].endpoint);
+
+	if (if_desc->bNumEndpoints == 0) {
+		usbi_dbg("no endpoints found for interface %d", iface);
+		return LIBUSB_SUCCESS;
+	}
+
+	priv->usb_interface[iface].endpoint = malloc(if_desc->bNumEndpoints);
+	if (priv->usb_interface[iface].endpoint == NULL) {
+		return LIBUSB_ERROR_NO_MEM;
+	}
+
+	priv->usb_interface[iface].nb_endpoints = if_desc->bNumEndpoints;
+	for (i=0; i<if_desc->bNumEndpoints; i++) {
+		priv->usb_interface[iface].endpoint[i] = if_desc->endpoint[i].bEndpointAddress;
+		usbi_dbg("(re)assigned endpoint %02X to interface %d", priv->usb_interface[iface].endpoint[i], iface);
+	}
+	libusb_free_config_descriptor(conf_desc);
+
+	return LIBUSB_SUCCESS;
+}
+
+// Lookup for a match in the list of API driver names
+bool is_api_driver(char* driver, uint8_t api)
+{
+	uint8_t i;
+	const char sep_str[2] = {LIST_SEPARATOR, 0};
+	char *tok, *tmp_str;
+	size_t len = safe_strlen(driver);
+
+	if (len == 0) return false;
+	tmp_str = calloc(len+1, 1);
+	if (tmp_str == NULL) return false;
+	memcpy(tmp_str, driver, len+1);
+	tok = strtok(tmp_str, sep_str);
+	while (tok != NULL) {
+		for (i=0; i<usb_api_backend[api].nb_driver_names; i++) {
+			if (safe_strcmp(tok, usb_api_backend[api].driver_name_list[i]) == 0) {
+				free(tmp_str);
+				return true;
+			}
+		}
+		tok = strtok(NULL, sep_str);
+	}
+	free (tmp_str);
+	return false;
+}
+
+/*
+ * auto-claiming and auto-release helper functions
+ */
+#if defined(AUTO_CLAIM)
+static int auto_claim(struct libusb_transfer *transfer, int *interface_number, int api_type)
+{
+	struct libusb_context *ctx = DEVICE_CTX(transfer->dev_handle->dev);
+	struct windows_device_handle_priv *handle_priv = __device_handle_priv(
+		transfer->dev_handle);
+	struct windows_device_priv *priv = __device_priv(transfer->dev_handle->dev);
+	int current_interface = *interface_number;
+	int r = LIBUSB_SUCCESS;
+
+	switch(api_type) {
+	case USB_API_WINUSB:
+	case USB_API_HID:
+		break;
+	default:
+		return LIBUSB_ERROR_INVALID_PARAM;
+	}
+
+	usbi_mutex_lock(&autoclaim_lock);
+	if (current_interface < 0)	// No serviceable interface was found
+	{
+		for (current_interface=0; current_interface<USB_MAXINTERFACES; current_interface++) {
+			// Must claim an interface of the same API type
+			if ( (priv->usb_interface[current_interface].apib == &usb_api_backend[api_type])
+			  && (libusb_claim_interface(transfer->dev_handle, current_interface) == LIBUSB_SUCCESS) ) {
+				usbi_dbg("auto-claimed interface %d for control request", current_interface);
+				if (handle_priv->autoclaim_count[current_interface] != 0) {
+					usbi_warn(ctx, "program assertion failed - autoclaim_count was nonzero");
+				}
+				handle_priv->autoclaim_count[current_interface]++;
+				break;
+			}
+		}
+		if (current_interface == USB_MAXINTERFACES) {
+			usbi_err(ctx, "could not auto-claim any interface");
+			r = LIBUSB_ERROR_NOT_FOUND;
+		}
+	} else {
+		// If we have a valid interface that was autoclaimed, we must increment
+		// its autoclaim count so that we can prevent an early release.
+		if (handle_priv->autoclaim_count[current_interface] != 0) {
+			handle_priv->autoclaim_count[current_interface]++;
+		}
+	}
+	usbi_mutex_unlock(&autoclaim_lock);
+
+	*interface_number = current_interface;
+	return r;
+
+}
+
+static void auto_release(struct usbi_transfer *itransfer)
+{
+	struct windows_transfer_priv *transfer_priv = usbi_transfer_get_os_priv(itransfer);
+	struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	libusb_device_handle *dev_handle = transfer->dev_handle;
+	struct windows_device_handle_priv* handle_priv = __device_handle_priv(dev_handle);
+	int r;
+
+	usbi_mutex_lock(&autoclaim_lock);
+	if (handle_priv->autoclaim_count[transfer_priv->interface_number] > 0) {
+		handle_priv->autoclaim_count[transfer_priv->interface_number]--;
+		if (handle_priv->autoclaim_count[transfer_priv->interface_number] == 0) {
+			r = libusb_release_interface(dev_handle, transfer_priv->interface_number);
+			if (r == LIBUSB_SUCCESS) {
+				usbi_dbg("auto-released interface %d", transfer_priv->interface_number);
+			} else {
+				usbi_dbg("failed to auto-release interface %d (%s)",
+					transfer_priv->interface_number, libusb_strerror(r));
+			}
+		}
+	}
+	usbi_mutex_unlock(&autoclaim_lock);
+}
+#endif
+
+
+/*
+ * init: libusb backend init function
+ *
+ * This function enumerates the HCDs (Host Controller Drivers) and populates our private HCD list
+ * In our implementation, we equate Windows' "HCD" to LibUSB's "bus". Note that bus is zero indexed.
+ * HCDs are not expected to change after init (might not hold true for hot pluggable USB PCI card?)
+ */
+static int windows_init(struct libusb_context *ctx)
+{
+	HDEVINFO dev_info;
+	SP_DEVICE_INTERFACE_DETAIL_DATA *dev_interface_details = NULL;
+	GUID guid;
+	libusb_bus_t bus;
+	int i, r = LIBUSB_ERROR_OTHER;
+	OSVERSIONINFO os_version;
+	HANDLE semaphore;
+	struct windows_hcd_priv** _hcd_cur;
+	TCHAR sem_name[11+1+8]; // strlen(libusb_init)+'\0'+(32-bit hex PID)
+
+	sprintf(sem_name, "libusb_init%08X", (unsigned int)GetCurrentProcessId()&0xFFFFFFFF);
+	semaphore = CreateSemaphore(NULL, 1, 1, sem_name);
+	if (semaphore == NULL) {
+		usbi_err(ctx, "could not create semaphore: %s", windows_error_str(0));
+		return LIBUSB_ERROR_NO_MEM;
+	}
+
+	// A successful wait brings our semaphore count to 0 (unsignaled)
+	// => any concurent wait stalls until the semaphore's release
+	if (WaitForSingleObject(semaphore, INFINITE) != WAIT_OBJECT_0) {
+		usbi_err(ctx, "failure to access semaphore: %s", windows_error_str(0));
+		CloseHandle(semaphore);
+		return LIBUSB_ERROR_NO_MEM;
+    }
+
+	// NB: concurrent usage supposes that init calls are equally balanced with
+	// exit calls. If init is called more than exit, we will not exit properly
+	if ( ++concurrent_usage == 0 ) {	// First init?
+		_hcd_cur = &hcd_root;
+
+		// Detect OS version
+		memset(&os_version, 0, sizeof(OSVERSIONINFO));
+		os_version.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
+		windows_version = WINDOWS_UNSUPPORTED;
+		if ((GetVersionEx(&os_version) != 0) && (os_version.dwPlatformId == VER_PLATFORM_WIN32_NT)) {
+			if ((os_version.dwMajorVersion == 5) && (os_version.dwMinorVersion == 1)) {
+				windows_version = WINDOWS_XP;
+			} else if ((os_version.dwMajorVersion == 5) && (os_version.dwMinorVersion == 2)) {
+				windows_version = WINDOWS_2003;	// also includes XP 64
+			} else if (os_version.dwMajorVersion >= 6) {
+				windows_version = WINDOWS_VISTA_AND_LATER;
+			}
+		}
+		if (windows_version == WINDOWS_UNSUPPORTED) {
+			usbi_err(ctx, "This version of Windows is NOT supported");
+			r = LIBUSB_ERROR_NOT_SUPPORTED;
+			goto init_exit;
+		}
+
+#if defined(AUTO_CLAIM)
+		// We need a lock for proper auto-release
+		usbi_mutex_init(&autoclaim_lock, NULL);
+#endif
+
+		// Initialize pollable file descriptors
+		init_polling();
+
+		// Load missing CFGMGR32.DLL imports
+		if (Cfgmgr32_init() != LIBUSB_SUCCESS) {
+			usbi_err(ctx, "could not resolve Cfgmgr32.dll functions");
+			return LIBUSB_ERROR_NOT_FOUND;
+		}
+
+		// Initialize the low level APIs (we don't care about errors at this stage)
+		for (i=0; i<USB_API_MAX; i++) {
+			usb_api_backend[i].init(ctx);
+		}
+
+		// Because QueryPerformanceCounter might report different values when
+		// running on different cores, we create a separate thread for the timer
+		// calls, which we glue to the first core always to prevent timing discrepancies.
+		r = LIBUSB_ERROR_NO_MEM;
+		for (i = 0; i < 2; i++) {
+			timer_request[i] = CreateEvent(NULL, TRUE, FALSE, NULL);
+			if (timer_request[i] == NULL) {
+				usbi_err(ctx, "could not create timer request event %d - aborting", i);
+				goto init_exit;
+			}
+		}
+		timer_response = CreateSemaphore(NULL, 0, MAX_TIMER_SEMAPHORES, NULL);
+		if (timer_response == NULL) {
+			usbi_err(ctx, "could not create timer response semaphore - aborting");
+			goto init_exit;
+		}
+		timer_mutex = CreateMutex(NULL, FALSE, NULL);
+		if (timer_mutex == NULL) {
+			usbi_err(ctx, "could not create timer mutex - aborting");
+			goto init_exit;
+		}
+		timer_thread = (HANDLE)_beginthreadex(NULL, 0, windows_clock_gettime_threaded, NULL, 0, NULL);
+		if (timer_thread == NULL) {
+			usbi_err(ctx, "Unable to create timer thread - aborting");
+			goto init_exit;
+		}
+		SetThreadAffinityMask(timer_thread, 0);
+
+		guid = GUID_DEVINTERFACE_USB_HOST_CONTROLLER;
+
+		r = LIBUSB_SUCCESS;
+		for (bus = 0; ; bus++)
+		{
+			// safe loop: free up any (unprotected) dynamic resource
+			// NB: this is always executed before breaking the loop
+			safe_free(dev_interface_details);
+			safe_free(*_hcd_cur);
+
+			dev_interface_details = get_interface_details(ctx, &dev_info, NULL, guid, bus);
+			// safe loop: end of loop condition
+			if ((dev_interface_details == NULL) || (r != LIBUSB_SUCCESS))
+				break;
+
+			// Will need to change storage and size of libusb_bus_t if this ever occurs
+			if (bus == LIBUSB_BUS_MAX) {
+				usbi_warn(ctx, "program assertion failed - found more than %d buses, skipping the rest.", LIBUSB_BUS_MAX);
+				continue;
+			}
+
+			// Allocate and init a new priv structure to hold our data
+			if ((*_hcd_cur = malloc(sizeof(struct windows_hcd_priv))) == NULL) {
+				usbi_err(ctx, "could not allocate private structure for bus %u. aborting.", bus);
+				LOOP_BREAK(LIBUSB_ERROR_NO_MEM);
+			}
+			windows_hcd_priv_init(*_hcd_cur);
+			(*_hcd_cur)->path = sanitize_path(dev_interface_details->DevicePath);
+
+			_hcd_cur = &((*_hcd_cur)->next);
+		}
+		// TODO (2nd official release): thread for hotplug (see darwin source)
+	}
+
+	if (hcd_root == NULL)
+		r = LIBUSB_ERROR_NO_DEVICE;
+	else
+		r = LIBUSB_SUCCESS;
+
+init_exit: // Holds semaphore here.
+	if(!concurrent_usage && r != LIBUSB_SUCCESS) { // First init failed?
+		if (timer_thread) {
+			SetEvent(timer_request[1]); // actually the signal to quit the thread.
+			if (WAIT_OBJECT_0 != WaitForSingleObject(timer_thread, INFINITE)) {
+				usbi_warn(ctx, "could not wait for timer thread to quit");
+				TerminateThread(timer_thread, 1); // shouldn't happen, but we're destroying
+												  // all objects it might have held anyway.
+			}
+			CloseHandle(timer_thread);
+			timer_thread = NULL;
+		}
+		for (i = 0; i < 2; i++) {
+			if (timer_request[i]) {
+				CloseHandle(timer_request[i]);
+				timer_request[i] = NULL;
+			}
+		}
+		if (timer_response) {
+			CloseHandle(timer_response);
+			timer_response = NULL;
+		}
+		if (timer_mutex) {
+			CloseHandle(timer_mutex);
+			timer_mutex = NULL;
+		}
+	}
+
+	if (r != LIBUSB_SUCCESS)
+		--concurrent_usage; // Not expected to call libusb_exit if we failed.
+
+	ReleaseSemaphore(semaphore, 1, NULL);	// increase count back to 1
+	CloseHandle(semaphore);
+	return r;
+}
+
+/*
+ * Initialize device structure, including active config
+ */
+static int initialize_device(struct libusb_device *dev, libusb_bus_t busnum,
+	libusb_devaddr_t devaddr, char *path, int connection_index, uint8_t active_config,
+	struct libusb_device *parent_dev)
+{
+	struct windows_device_priv *priv = __device_priv(dev);
+
+	windows_device_priv_init(priv);
+
+	dev->bus_number = busnum;
+	dev->device_address = devaddr;
+	priv->path = path;
+	priv->connection_index = connection_index;
+	priv->parent_dev = parent_dev;
+
+	priv->active_config = active_config;
+
+	if (priv->active_config != 0) {
+		usbi_dbg("active config: %d", priv->active_config);
+	} else {
+		// USB devices that don't have a config value are usually missing a driver
+		// TODO (after first official release): use this for automated driver installation
+		// NB: SetupDiGetDeviceRegistryProperty w/ SPDRP_INSTALL_STATE would tell us
+		// if the driver is properly installed, but driverless devices don't seem to
+		// be enumerable by SetupDi...
+		usbi_dbg("* This device has no driver => libusb will not be able to access it *");
+	}
+
+	return LIBUSB_SUCCESS;
+}
+
+/*
+ * HCD (root) hubs need to have their device descriptor manually populated
+ *
+ * Note that we follow the Linux convention and use the "Linux Foundation root hub"
+ * vendor ID as well as the product ID to indicate the hub speed
+ */
+static int force_hcd_device_descriptor(struct libusb_device *dev, HANDLE handle)
+{
+	DWORD size;
+	USB_HUB_CAPABILITIES hub_caps;
+	USB_HUB_CAPABILITIES_EX hub_caps_ex;
+	struct windows_device_priv *priv = __device_priv(dev);
+	struct libusb_context *ctx = DEVICE_CTX(dev);
+
+	priv->dev_descriptor.bLength = sizeof(USB_DEVICE_DESCRIPTOR);
+	priv->dev_descriptor.bDescriptorType = USB_DEVICE_DESCRIPTOR_TYPE;
+	dev->num_configurations = priv->dev_descriptor.bNumConfigurations = 1;
+
+	// The following is used to set the VIS:PID of root HUBs similarly to what
+	// Linux does: 1d6b:0001 is for 1x root hubs, 1d6b:0002 for 2x
+	priv->dev_descriptor.idVendor = 0x1d6b;		// Linux Foundation root hub
+	if (windows_version >= WINDOWS_VISTA_AND_LATER) {
+		size = sizeof(USB_HUB_CAPABILITIES_EX);
+		if (DeviceIoControl(handle, IOCTL_USB_GET_HUB_CAPABILITIES_EX, &hub_caps_ex,
+			size, &hub_caps_ex, size, &size, NULL)) {
+			// Sanity check. HCD hub should always be root
+			if (!hub_caps_ex.CapabilityFlags.HubIsRoot) {
+				usbi_warn(ctx, "program assertion failed - HCD hub is not reported as root hub.");
+			}
+			priv->dev_descriptor.idProduct = hub_caps_ex.CapabilityFlags.HubIsHighSpeedCapable?2:1;
+		}
+	} else {
+		size = sizeof(USB_HUB_CAPABILITIES);
+		if (!DeviceIoControl(handle, IOCTL_USB_GET_HUB_CAPABILITIES, &hub_caps,
+			size, &hub_caps, size, &size, NULL)) {
+			usbi_warn(ctx, "could not read hub capabilities (std) for hub %s: %s",
+				priv->path, windows_error_str(0));
+			priv->dev_descriptor.idProduct = 1;	// Indicate 1x speed
+		} else {
+			priv->dev_descriptor.idProduct = hub_caps.HubIs2xCapable?2:1;
+		}
+	}
+
+	return LIBUSB_SUCCESS;
+}
+
+/*
+ * fetch and cache all the config descriptors through I/O
+ */
+static int cache_config_descriptors(struct libusb_device *dev, HANDLE hub_handle)
+{
+	DWORD size, ret_size;
+	struct libusb_context *ctx = DEVICE_CTX(dev);
+	struct windows_device_priv *priv = __device_priv(dev);
+	int r;
+	uint8_t i;
+
+	USB_CONFIGURATION_DESCRIPTOR_SHORT cd_buf_short;    // dummy request
+	PUSB_DESCRIPTOR_REQUEST cd_buf_actual = NULL;       // actual request
+	PUSB_CONFIGURATION_DESCRIPTOR cd_data = NULL;
+
+	if (dev->num_configurations == 0)
+		return LIBUSB_ERROR_INVALID_PARAM;
+
+	priv->config_descriptor = malloc(dev->num_configurations * sizeof(PUSB_CONFIGURATION_DESCRIPTOR));
+	if (priv->config_descriptor == NULL)
+		return LIBUSB_ERROR_NO_MEM;
+	for (i=0; i<dev->num_configurations; i++)
+		priv->config_descriptor[i] = NULL;
+
+	for (i=0, r=LIBUSB_SUCCESS; ; i++)
+	{
+		// safe loop: release all dynamic resources
+		safe_free(cd_buf_actual);
+
+		// safe loop: end of loop condition
+		if ((i >= dev->num_configurations) || (r != LIBUSB_SUCCESS))
+			break;
+
+		size = sizeof(USB_CONFIGURATION_DESCRIPTOR_SHORT);
+		memset(&cd_buf_short, 0, size);
+
+		cd_buf_short.req.ConnectionIndex = priv->connection_index;
+		cd_buf_short.req.SetupPacket.bmRequest = LIBUSB_ENDPOINT_IN;
+		cd_buf_short.req.SetupPacket.bRequest = USB_REQUEST_GET_DESCRIPTOR;
+		cd_buf_short.req.SetupPacket.wValue = (USB_CONFIGURATION_DESCRIPTOR_TYPE << 8) | i;
+		cd_buf_short.req.SetupPacket.wIndex = i;
+		cd_buf_short.req.SetupPacket.wLength = (USHORT)(size - sizeof(USB_DESCRIPTOR_REQUEST));
+
+		// Dummy call to get the required data size
+		if (!DeviceIoControl(hub_handle, IOCTL_USB_GET_DESCRIPTOR_FROM_NODE_CONNECTION, &cd_buf_short, size,
+			&cd_buf_short, size, &ret_size, NULL)) {
+			usbi_err(ctx, "could not access configuration descriptor (dummy): %s", windows_error_str(0));
+			LOOP_BREAK(LIBUSB_ERROR_IO);
+		}
+
+		if ((ret_size != size) || (cd_buf_short.data.wTotalLength < sizeof(USB_CONFIGURATION_DESCRIPTOR))) {
+			usbi_err(ctx, "unexpected configuration descriptor size (dummy).");
+			LOOP_BREAK(LIBUSB_ERROR_IO);
+		}
+
+		size = sizeof(USB_DESCRIPTOR_REQUEST) + cd_buf_short.data.wTotalLength;
+		if ((cd_buf_actual = (PUSB_DESCRIPTOR_REQUEST)malloc(size)) == NULL) {
+			usbi_err(ctx, "could not allocate configuration descriptor buffer. aborting.");
+			LOOP_BREAK(LIBUSB_ERROR_NO_MEM);
+		}
+		memset(cd_buf_actual, 0, size);
+
+		// Actual call
+		cd_buf_actual->ConnectionIndex = priv->connection_index;
+		cd_buf_actual->SetupPacket.bmRequest = LIBUSB_ENDPOINT_IN;
+		cd_buf_actual->SetupPacket.bRequest = USB_REQUEST_GET_DESCRIPTOR;
+		cd_buf_actual->SetupPacket.wValue = (USB_CONFIGURATION_DESCRIPTOR_TYPE << 8) | i;
+		cd_buf_actual->SetupPacket.wIndex = i;
+		cd_buf_actual->SetupPacket.wLength = (USHORT)(size - sizeof(USB_DESCRIPTOR_REQUEST));
+
+		if (!DeviceIoControl(hub_handle, IOCTL_USB_GET_DESCRIPTOR_FROM_NODE_CONNECTION, cd_buf_actual, size,
+			cd_buf_actual, size, &ret_size, NULL)) {
+			usbi_err(ctx, "could not access configuration descriptor (actual): %s", windows_error_str(0));
+			LOOP_BREAK(LIBUSB_ERROR_IO);
+		}
+
+		cd_data = (PUSB_CONFIGURATION_DESCRIPTOR)((UCHAR*)cd_buf_actual+sizeof(USB_DESCRIPTOR_REQUEST));
+
+		if ((size != ret_size) || (cd_data->wTotalLength != cd_buf_short.data.wTotalLength)) {
+			usbi_err(ctx, "unexpected configuration descriptor size (actual).");
+			LOOP_BREAK(LIBUSB_ERROR_IO);
+		}
+
+		if (cd_data->bDescriptorType != USB_CONFIGURATION_DESCRIPTOR_TYPE) {
+			usbi_err(ctx, "not a configuration descriptor");
+			LOOP_BREAK(LIBUSB_ERROR_IO);
+		}
+
+		usbi_dbg("cached config descriptor #%d (%d bytes)", i+1, cd_data->wTotalLength);
+
+		// Sanity check. Ensures that indexes for our list of config desc is in the right order
+		if (i != (cd_data->bConfigurationValue-1)) {
+			usbi_warn(ctx, "program assertion failed - config descriptors are being read out of order");
+			continue;
+		}
+
+		// Cache the descriptor
+		priv->config_descriptor[i] = malloc(cd_data->wTotalLength);
+		if (priv->config_descriptor[i] == NULL)
+			return LIBUSB_ERROR_NO_MEM;
+
+		memcpy(priv->config_descriptor[i], cd_data, cd_data->wTotalLength);
+	}
+	return LIBUSB_SUCCESS;
+}
+
+/*
+ * Recursively enumerates and finds all hubs & devices
+ */
+static int usb_enumerate_hub(struct libusb_context *ctx, struct discovered_devs **_discdevs,
+	HANDLE hub_handle, libusb_bus_t busnum, struct libusb_device *parent_dev, uint8_t nb_ports)
+{
+	struct discovered_devs *discdevs = *_discdevs;
+	struct libusb_device *dev = NULL;
+	DWORD size, size_initial, size_fixed, getname_ioctl;
+	HANDLE handle = INVALID_HANDLE_VALUE;
+	USB_HUB_NAME_FIXED s_hubname;
+	USB_NODE_CONNECTION_INFORMATION conn_info;
+	USB_NODE_INFORMATION hub_node;
+	bool is_hcd, need_unref = false;
+	int i, r;
+	LPCWSTR wstr;
+	char *tmp_str = NULL, *path_str = NULL;
+	unsigned long session_id;
+	libusb_devaddr_t devaddr = 0;
+	struct windows_device_priv *priv, *parent_priv;
+
+	// obviously, root (HCD) hubs have no parent
+	is_hcd = (parent_dev == NULL);
+	if (is_hcd)
+	{
+		if (nb_ports != 1) {
+			usbi_warn(ctx, "program assertion failed - invalid number of ports for HCD.");
+			return LIBUSB_ERROR_INVALID_PARAM;
+		}
+		parent_priv = NULL;
+		size_initial = sizeof(USB_ROOT_HUB_NAME);
+		size_fixed = sizeof(USB_ROOT_HUB_NAME_FIXED);
+		getname_ioctl = IOCTL_USB_GET_ROOT_HUB_NAME;
+	}
+	else
+	{
+		parent_priv = __device_priv(parent_dev);
+		size_initial = sizeof(USB_NODE_CONNECTION_NAME);
+		size_fixed = sizeof(USB_NODE_CONNECTION_NAME_FIXED);
+		getname_ioctl = IOCTL_USB_GET_NODE_CONNECTION_NAME;
+	}
+
+	// Loop through all the ports on this hub
+	for (i = 1, r = LIBUSB_SUCCESS; ; i++)
+	{
+		// safe loop: release all dynamic resources
+		if (need_unref) {
+			safe_unref_device(dev);
+			need_unref = false;
+		}
+		safe_free(tmp_str);
+		safe_free(path_str);
+		safe_closehandle(handle);
+
+		// safe loop: end of loop condition
+		if ((i > nb_ports) || (r != LIBUSB_SUCCESS))
+			break;
+
+		memset(&conn_info, 0, sizeof(conn_info));
+		// For non HCDs, check if the node on this port is a hub or a regular device
+		if (!is_hcd) {
+			size = sizeof(USB_NODE_CONNECTION_INFORMATION);
+			conn_info.ConnectionIndex = i;
+			if (!DeviceIoControl(hub_handle, IOCTL_USB_GET_NODE_CONNECTION_INFORMATION, &conn_info, size,
+				&conn_info, size, &size, NULL)) {
+				usbi_warn(ctx, "could not get node connection information: %s", windows_error_str(0));
+				continue;
+			}
+
+			if (conn_info.ConnectionStatus == NoDeviceConnected) {
+				continue;
+			}
+
+			if (conn_info.DeviceAddress == LIBUSB_DEVADDR_MAX) {
+				usbi_warn(ctx, "program assertion failed - device address is %d "
+					"(conflicts with root hub), ignoring device", LIBUSB_DEVADDR_MAX);
+				continue;
+			}
+
+			s_hubname.u.node.ConnectionIndex = i;	// Only used for non HCDs (s_hubname is an union)
+		}
+		else
+		{
+			// HCDs have only 1 node, and it's always a hub
+			conn_info.DeviceAddress = LIBUSB_DEVADDR_MAX;	// using 0 can conflict with driverless devices
+			conn_info.DeviceIsHub = true;
+			conn_info.CurrentConfigurationValue = 1;
+		}
+
+		// If this node is a hub (HCD or not), open it
+		if (conn_info.DeviceIsHub) {
+			size = size_initial;
+			if (!DeviceIoControl(hub_handle, getname_ioctl, &s_hubname, size,
+				&s_hubname, size, &size, NULL)) {
+				usbi_warn(ctx, "could not get hub path (dummy): %s", windows_error_str(0));
+				continue;
+			}
+
+			size = is_hcd?s_hubname.u.root.ActualLength:s_hubname.u.node.ActualLength;
+			if (size > size_fixed) {
+				usbi_warn(ctx, "program assertion failed - hub path is too long");
+				continue;
+			}
+
+			if (!is_hcd) {
+				// previous call trashes some of the data
+				s_hubname.u.node.ConnectionIndex = i;
+			}
+			if (!DeviceIoControl(hub_handle, getname_ioctl, &s_hubname, size,
+				&s_hubname, size, &size, NULL)) {
+				usbi_warn(ctx, "could not get hub path (actual): %s", windows_error_str(0));
+				continue;
+			}
+
+			// Add prefix
+			wstr = is_hcd?s_hubname.u.root.RootHubName:s_hubname.u.node.NodeName;
+			tmp_str = wchar_to_utf8(wstr);
+			if (tmp_str == NULL) {
+				usbi_err(ctx, "could not convert hub path string.");
+				LOOP_BREAK(LIBUSB_ERROR_NO_MEM);
+			}
+
+			path_str = sanitize_path(tmp_str);
+			if (path_str == NULL) {
+				usbi_err(ctx, "could not sanitize hub path string.");
+				LOOP_BREAK(LIBUSB_ERROR_NO_MEM);
+			}
+
+			// Open Hub
+			handle = CreateFileA(path_str, GENERIC_WRITE, FILE_SHARE_WRITE, NULL, OPEN_EXISTING,
+				FILE_FLAG_OVERLAPPED, NULL);
+			if(handle == INVALID_HANDLE_VALUE) {
+				usbi_warn(ctx, "could not open hub %s: %s", path_str, windows_error_str(0));
+				continue;
+			}
+		}
+
+		// Generate a session ID
+		// Will need to change the session_id computation if this assertion fails
+		if (conn_info.DeviceAddress > LIBUSB_DEVADDR_MAX) {
+			usbi_warn(ctx, "program assertion failed - device address is greater than %d, ignoring device",
+				LIBUSB_DEVADDR_MAX);
+			continue;
+		} else {
+			devaddr = (uint8_t)conn_info.DeviceAddress;
+		}
+		// Same trick as linux for session_id, with same caveat
+		session_id = busnum << (sizeof(libusb_devaddr_t)*8) | devaddr;
+		usbi_dbg("busnum %d devaddr %d session_id %ld", busnum, devaddr, session_id);
+
+		// Allocate device if needed
+		dev = usbi_get_device_by_session_id(ctx, session_id);
+		if (dev) {
+			usbi_dbg("using existing device for session %ld", session_id);
+			priv = __device_priv(dev);
+			// Because we are rebuilding the list, there's no guarantee
+			// the parent device pointer is still the same.
+			// Other device data should still be reusable
+			priv->parent_dev = parent_dev;
+		} else {
+			usbi_dbg("allocating new device for session %ld", session_id);
+			if ((dev = usbi_alloc_device(ctx, session_id)) == NULL) {
+				LOOP_BREAK(LIBUSB_ERROR_NO_MEM);
+			}
+			need_unref = true;
+
+			LOOP_CHECK(initialize_device(dev, busnum, devaddr, path_str, i,
+				conn_info.CurrentConfigurationValue, parent_dev));
+			priv = __device_priv(dev);
+
+			path_str = NULL;	// protect our path from being freed
+
+			// Setup the cached descriptors. Note that only non HCDs can fetch descriptors
+			if (!is_hcd) {
+				// The device descriptor has been read with conn_info
+				memcpy(&priv->dev_descriptor, &(conn_info.DeviceDescriptor), sizeof(USB_DEVICE_DESCRIPTOR));
+				dev->num_configurations = priv->dev_descriptor.bNumConfigurations;
+				// If we can't read the config descriptors, just set the number of confs to zero
+				if (cache_config_descriptors(dev, hub_handle) != LIBUSB_SUCCESS) {
+					dev->num_configurations = 0;
+					priv->dev_descriptor.bNumConfigurations = 0;
+				}
+			} else {
+				LOOP_CHECK(force_hcd_device_descriptor(dev, handle));
+			}
+			LOOP_CHECK(usbi_sanitize_device(dev));
+		}
+
+		discdevs = discovered_devs_append(*_discdevs, dev);
+		if (!discdevs) {
+			LOOP_BREAK(LIBUSB_ERROR_NO_MEM);
+		}
+
+		*_discdevs = discdevs;
+
+		// Finally, if device is a hub, recurse
+		if (conn_info.DeviceIsHub) {
+			// Find number of ports for this hub
+			size =  sizeof(USB_NODE_INFORMATION);
+			if (!DeviceIoControl(handle, IOCTL_USB_GET_NODE_INFORMATION, &hub_node, size,
+				&hub_node, size, &size, NULL)) {
+				usbi_warn(ctx, "could not retreive information for hub %s: %s",
+					priv->path, windows_error_str(0));
+				continue;
+			}
+
+			if (hub_node.NodeType != UsbHub) {
+				usbi_warn(ctx, "unexpected hub type (%d) for hub %s", hub_node.NodeType, priv->path);
+				continue;
+			}
+
+			usbi_dbg("%d ports Hub: %s", hub_node.u.HubInformation.HubDescriptor.bNumberOfPorts, priv->path);
+
+			usb_enumerate_hub(ctx, _discdevs, handle, busnum, dev,
+				hub_node.u.HubInformation.HubDescriptor.bNumberOfPorts);
+		}
+	}
+
+	return r;
+}
+
+/*
+ * Composite device interfaces are not enumerated using GUID_DEVINTERFACE_USB_DEVICE,
+ * but instead require a different lookup mechanism
+ */
+static int set_composite_device(struct libusb_context *ctx, DEVINST devinst, struct windows_device_priv *priv)
+{
+// indexes for additional interface GUIDs, not available from "USB"
+// SetupDiGetClassDevs enumeration should go here. Typically, these are
+// device interfaces that begin with something else than "\\?\usb\"
+enum libusb_hid_report_type {
+	HID_DEVICE_INTERFACE_GUID_INDEX   = 0,
+	MAX_DEVICE_INTERFACE_GUID_INDEX   = 1
+};
+
+	DEVINST child_devinst, parent_devinst;
+	unsigned i, j, max_guids, nb_paths, interface_number;
+	uint8_t api;
+	bool found;
+	DWORD type, size;
+	CONFIGRET r;
+	HDEVINFO dev_info;
+	SP_DEVINFO_DATA dev_info_data;
+	SP_DEVICE_INTERFACE_DETAIL_DATA *dev_interface_details = NULL;
+	HKEY key;
+	WCHAR guid_string_w[MAX_GUID_STRING_LENGTH];
+	GUID guid, class_guid;
+	GUID guid_table[MAX_USB_DEVICES];
+	char* sanitized_path[MAX_USB_DEVICES];
+	char* hid_path[MAX_USB_DEVICES]; // An extra path is needed for HID
+	uint8_t api_type[MAX_USB_DEVICES];
+	char* sanitized_short = NULL;
+	char path[MAX_PATH_LENGTH];
+	char driver[MAX_KEY_LENGTH];
+
+	dev_info = SetupDiGetClassDevs(NULL, "USB", NULL, DIGCF_PRESENT|DIGCF_ALLCLASSES);
+	if (dev_info == INVALID_HANDLE_VALUE) {
+		return LIBUSB_ERROR_NOT_FOUND;
+	}
+
+	// Manually add the HID GUID as it cannot be read with DeviceInterfaceGUIDs reg key)
+	// NB the value returned by HidD_GetHidGuid, which is for interface class is different
+	// from GUID_HID, which is the device class GUID
+	HidD_GetHidGuid(&guid_table[HID_DEVICE_INTERFACE_GUID_INDEX]);
+	// NB: for other interface guids, SetupDiClassGuidsFromName can be used
+	max_guids = MAX_DEVICE_INTERFACE_GUID_INDEX;
+
+	// First, retrieve all the device interface GUIDs
+	for (i = 0; ; i++)
+	{
+		dev_info_data.cbSize = sizeof(dev_info_data);
+		if (!SetupDiEnumDeviceInfo(dev_info, i, &dev_info_data)) {
+			break;
+		}
+
+		key = SetupDiOpenDevRegKey(dev_info, &dev_info_data, DICS_FLAG_GLOBAL, 0, DIREG_DEV, KEY_READ);
+		if (key == INVALID_HANDLE_VALUE) {
+			usbi_dbg("could not open registry key");
+			continue;
+		}
+
+		size = sizeof(guid_string_w);
+		r = RegQueryValueExW(key, L"DeviceInterfaceGUIDs", NULL, &type,
+			(BYTE*)guid_string_w, &size);
+		RegCloseKey(key);
+		if (r != ERROR_SUCCESS) {
+			continue;
+		}
+		CLSIDFromString(guid_string_w, &guid);
+
+		// identical device interface GUIDs are not supposed to happen, but are a real possibility
+		// => check and ignore duplicates
+		found = false;
+		for (j=0; j<max_guids; j++) {
+			if (memcmp(&guid_table[j], &guid, sizeof(GUID)) == 0) {
+				found = true;
+				break;
+			}
+		}
+		if (!found) {
+			guid_table[max_guids++] = guid;
+			if (max_guids > MAX_USB_DEVICES) {
+				usbi_warn(ctx, "more than %d devices - ignoring the rest", MAX_USB_DEVICES);
+				break;
+			}
+		}
+	}
+	SetupDiDestroyDeviceInfoList(dev_info);
+
+	// Now let's find the device interface paths for all these devices
+	nb_paths = 0;
+	for (j=0; j<max_guids; j++)
+	{
+		guid = guid_table[j];
+
+		for (i = 0; ; i++)
+		{
+			safe_free(dev_interface_details);
+			dev_interface_details = get_interface_details(ctx, &dev_info, &dev_info_data, guid, i);
+			if (dev_interface_details == NULL)
+				break;
+
+			// HID devices (and possibly other classes) have an extra indirection
+			// for an USB path we can recognize
+			if (j == HID_DEVICE_INTERFACE_GUID_INDEX) {
+				if (CM_Get_Parent(&parent_devinst, dev_info_data.DevInst, 0) != CR_SUCCESS) {
+					usbi_warn(ctx, "could not retrieve HID parent info data for device %s, skipping: %s",
+						dev_interface_details->DevicePath, windows_error_str(0));
+					continue;
+				}
+
+				if (CM_Get_Device_ID(parent_devinst, path, MAX_PATH_LENGTH, 0) != CR_SUCCESS) {
+					usbi_warn(ctx, "could not retrieve HID parent's path for device %s, skipping: %s",
+						dev_interface_details->DevicePath, windows_error_str(0));
+					continue;
+				}
+			}
+
+			// In case we can't read the driver string through SPDRP_SERVICE (which is
+			// the case for HID), we need the ClassGUID for comparison.
+			if(!SetupDiGetDeviceRegistryPropertyW(dev_info, &dev_info_data, SPDRP_CLASSGUID,
+				NULL, (BYTE*)guid_string_w, sizeof(guid_string_w), &size)) {
+				usbi_warn(ctx, "could not read class GUID for device %s, skipping: %s",
+					dev_interface_details->DevicePath, windows_error_str(0));
+				continue;
+			}
+			CLSIDFromString(guid_string_w, &class_guid);
+
+			// Attempt to read the driver string
+			if(!SetupDiGetDeviceRegistryProperty(dev_info, &dev_info_data, SPDRP_SERVICE,
+				NULL, (BYTE*)driver, MAX_KEY_LENGTH, &size)) {
+				driver[0] = 0;
+			}
+
+			for (api=USB_API_WINUSB; api<USB_API_MAX; api++) {
+				if ( (is_api_driver(driver, api))
+				  || (guid_eq(&class_guid, usb_api_backend[api].class_guid)) ) {
+					api_type[nb_paths] = api;
+					if (j == HID_DEVICE_INTERFACE_GUID_INDEX) {
+						hid_path[nb_paths] = sanitize_path(path);
+					} else {
+						hid_path[nb_paths] = NULL;
+					}
+					sanitized_path[nb_paths++] = sanitize_path(dev_interface_details->DevicePath);
+					if (nb_paths > MAX_USB_DEVICES) {
+						usbi_warn(ctx, "more than %d devices - ignoring the rest", MAX_USB_DEVICES);
+						break;
+					}
+				}
+			}
+		}
+	}
+
+	// Finally, match the interface paths with the interfaces. We do that
+	// by looking at the children of the composite device
+	// NB: if the interfaces are not found in their expected position,
+	// claim_interface will issue a warning
+	found = false;
+	memset(&child_devinst, 0, sizeof(DEVINST));	// prevents /W4 warning
+	for (i = 0; i<USB_MAXINTERFACES; i++)
+	{
+		if (i == 0) {
+			r = CM_Get_Child(&child_devinst, devinst, 0);
+		} else {
+			r = CM_Get_Sibling(&child_devinst, child_devinst, 0);
+		}
+		if (r == CR_NO_SUCH_DEVNODE) {	// end of the siblings
+			break;
+		} else if (r != CR_SUCCESS) {
+			usbi_dbg("unable to find interface sibling #%d, error = %X", i, r);
+			break;
+		}
+
+		r = CM_Get_Device_ID(child_devinst, path, MAX_PATH_LENGTH, 0);
+		if (r != CR_SUCCESS) {
+			usbi_err(ctx, "could not retrieve simple path for interface %d: CR error %d",
+				i, r);
+			continue;
+		}
+		sanitized_short = sanitize_path(path);
+		if (sanitized_short == NULL) {
+			usbi_err(ctx, "could not sanitize path for interface %d", i);
+			continue;
+		}
+
+		// Because MI_## are not necessarily in sequential order (some composite HID
+		// devices will have only MI_00 & MI_03 for instance), we retrieve the actual
+		// interface number from the path's MI value
+		interface_number = i;
+		for (j=0; sanitized_short[j] != 0; ) {
+			if ( (sanitized_short[j++] == 'M') && (sanitized_short[j++] == 'I')
+			  && (sanitized_short[j++] == '_') ) {
+				interface_number = (sanitized_short[j++] - '0')*10;
+				interface_number += sanitized_short[j] - '0';
+				break;
+			}
+		}
+		if (sanitized_short[j] == 0) {
+			usbi_warn(ctx, "failure to read interface number for %s. Using default value %d",
+				sanitized_short, interface_number);
+		}
+
+		for (j=0; j<nb_paths; j++) {
+			if ( (safe_strncmp(sanitized_path[j], sanitized_short, safe_strlen(sanitized_short)) == 0)
+			  || (safe_strcmp(hid_path[j], sanitized_short) == 0 ) ) {
+				// HID devices can have multiple collections (COL##) for each MI_## interface
+				if (priv->usb_interface[interface_number].path != NULL) {
+					usbi_dbg("interface_path[%d] already set - ignoring HID collection: %s",
+						interface_number, sanitized_path[j]);
+					if (api_type[j] != USB_API_HID) {
+						usbi_warn(ctx, "program assertion failed - not an HID collection");
+					}
+				} else {
+					priv->usb_interface[interface_number].path = sanitized_path[j];
+					priv->usb_interface[interface_number].apib = &usb_api_backend[api_type[j]];
+					if ((api_type[j] == USB_API_HID) && (priv->hid == NULL)) {
+							priv->hid = calloc(1, sizeof(struct hid_device_priv));
+					}
+					priv->composite_api_flags |= 1<<api_type[j];
+					sanitized_path[j] = NULL;
+				}
+			}
+		}
+		safe_free(sanitized_short);
+
+		if (priv->usb_interface[interface_number].path == NULL) {
+			usbi_warn(ctx, "interface_path[%d]: unhandled API - interface will be disabled",
+				interface_number);
+			continue;
+		}
+		usbi_dbg("interface_path[%d]: %s", interface_number, priv->usb_interface[interface_number].path);
+		found = true;
+	}
+
+	for (j=0; j<nb_paths; j++) {
+		safe_free(sanitized_path[j]);
+		safe_free(hid_path[j]);
+	}
+
+	if (found == 0) {
+		usbi_warn(ctx, "composite device: no interfaces were found");
+		return LIBUSB_ERROR_NOT_FOUND;
+	}
+
+	return LIBUSB_SUCCESS;
+}
+
+/*
+ * Likewise, HID device interfaces's path (\\.\HID\...) are not enumerated through the
+ * generic USB devices GUID, but are actually children of one such device
+ */
+static int set_hid_device(struct libusb_context *ctx, struct windows_device_priv *priv)
+ {
+	char path[MAX_PATH_LENGTH];
+	char *sanitized_path = NULL;
+	HDEVINFO dev_info;
+	SP_DEVICE_INTERFACE_DETAIL_DATA *dev_interface_details = NULL;
+	SP_DEVINFO_DATA dev_info_data;
+	DEVINST parent_devinst;
+	GUID guid;
+	int	r = LIBUSB_SUCCESS;
+	unsigned i, interface_number;
+
+	interface_number = 0;
+	HidD_GetHidGuid(&guid);
+	for (i = 0; ; i++)
+	{
+		// safe loop: free up any (unprotected) dynamic resource
+		safe_free(dev_interface_details);
+		safe_free(sanitized_path);
+
+		dev_interface_details = get_interface_details(ctx, &dev_info, &dev_info_data, guid, i);
+		// safe loop: end of loop condition
+		if ( (dev_interface_details == NULL)
+		  || (r != LIBUSB_SUCCESS) )
+			break;
+
+		// Retrieve parent's path using PnP Configuration Manager (CM)
+		if (CM_Get_Parent(&parent_devinst, dev_info_data.DevInst, 0) != CR_SUCCESS) {
+			usbi_warn(ctx, "could not retrieve parent info data for device %s, skipping: %s",
+				dev_interface_details->DevicePath, windows_error_str(0));
+			continue;
+		}
+
+		if (CM_Get_Device_ID(parent_devinst, path, MAX_PATH_LENGTH, 0) != CR_SUCCESS) {
+			usbi_warn(ctx, "could not retrieve parent's path for device %s, skipping: %s",
+				dev_interface_details->DevicePath, windows_error_str(0));
+			continue;
+		}
+
+		// Fix parent's path inconsistencies before attempting to compare
+		sanitized_path = sanitize_path(path);
+		if (sanitized_path == NULL) {
+			usbi_warn(ctx, "could not sanitize parent's path for device %s, skipping.",
+				dev_interface_details->DevicePath);
+			continue;
+		}
+
+		// NB: we compare strings of different lengths below => strncmp
+		if (safe_strncmp(priv->path, sanitized_path, safe_strlen(sanitized_path)) == 0) {
+			priv->usb_interface[interface_number].path = sanitize_path(dev_interface_details->DevicePath);
+			priv->usb_interface[interface_number].apib = &usb_api_backend[USB_API_HID];
+			usbi_dbg("interface_path[%d]: %s", interface_number, priv->usb_interface[interface_number].path);
+			interface_number++;
+		}
+	}
+
+	return LIBUSB_SUCCESS;
+}
+
+/*
+ * This function retrieves and sets the paths of all non-hub devices
+ * NB: No I/O with device is required during this call
+ */
+static int set_device_paths(struct libusb_context *ctx, struct discovered_devs *discdevs)
+{
+	// Precedence for filter drivers vs driver is in the order of this array
+	struct driver_lookup lookup[3] = {
+		{"\0\0", SPDRP_SERVICE, "driver"},
+		{"\0\0", SPDRP_UPPERFILTERS, "upper filter driver"},
+		{"\0\0", SPDRP_LOWERFILTERS, "lower filter driver"}
+	};
+	struct windows_device_priv *priv;
+	struct windows_device_priv *parent_priv;
+	char path[MAX_PATH_LENGTH];
+	char *sanitized_path = NULL;
+	HDEVINFO dev_info;
+	SP_DEVICE_INTERFACE_DETAIL_DATA *dev_interface_details = NULL;
+	SP_DEVINFO_DATA dev_info_data;
+	DEVINST parent_devinst;
+	GUID guid;
+	DWORD size, reg_type, install_state, port_nr;
+	int r = LIBUSB_SUCCESS;
+	unsigned i, j, k, l;
+	uint8_t api;
+	bool found;
+
+	// TODO (after first official release): MI_## automated driver installation
+	guid = GUID_DEVINTERFACE_USB_DEVICE;
+	for (i = 0; ; i++)
+	{
+		// safe loop: free up any (unprotected) dynamic resource
+		safe_free(dev_interface_details);
+		safe_free(sanitized_path);
+
+		dev_interface_details = get_interface_details(ctx, &dev_info, &dev_info_data, guid, i);
+		// safe loop: end of loop condition
+		if ( (dev_interface_details == NULL)
+		  || (r != LIBUSB_SUCCESS) )
+			break;
+
+		// Check that the driver installation is OK
+		if ( (!SetupDiGetDeviceRegistryProperty(dev_info, &dev_info_data, SPDRP_INSTALL_STATE,
+			&reg_type, (BYTE*)&install_state, 4, &size))
+		  && (size != 4) ){
+			usbi_warn(ctx, "could not detect installation state of driver for %s: %s",
+				dev_interface_details->DevicePath, windows_error_str(0));
+		} else if (install_state != 0) {
+			usbi_warn(ctx, "driver for device %s is reporting an issue (code: %d) - skipping",
+				dev_interface_details->DevicePath, install_state);
+			continue;
+		}
+
+		// The SPDRP_ADDRESS for USB devices should be the device port number on the hub
+		if ( (!SetupDiGetDeviceRegistryProperty(dev_info, &dev_info_data, SPDRP_ADDRESS,
+			&reg_type, (BYTE*)&port_nr, 4, &size))
+		  && (size != 4) ){
+			usbi_warn(ctx, "could not retrieve port number for device %s, skipping: %s",
+				dev_interface_details->DevicePath, windows_error_str(0));
+			continue;
+		}
+
+		// Retrieve parent's path using PnP Configuration Manager (CM)
+		if (CM_Get_Parent(&parent_devinst, dev_info_data.DevInst, 0) != CR_SUCCESS) {
+			usbi_warn(ctx, "could not retrieve parent info data for device %s, skipping: %s",
+				dev_interface_details->DevicePath, windows_error_str(0));
+			continue;
+		}
+
+		if (CM_Get_Device_ID(parent_devinst, path, MAX_PATH_LENGTH, 0) != CR_SUCCESS) {
+			usbi_warn(ctx, "could not retrieve parent's path for device %s, skipping: %s",
+				dev_interface_details->DevicePath, windows_error_str(0));
+			continue;
+		}
+
+		// Fix parent's path inconsistencies before attempting to compare
+		sanitized_path = sanitize_path(path);
+		if (sanitized_path == NULL) {
+			usbi_warn(ctx, "could not sanitize parent's path for device %s, skipping.",
+				dev_interface_details->DevicePath);
+			continue;
+		}
+
+		// With the parent path and port number, we should be able to locate our device
+		// by comparing these values to the ones we got when enumerating hubs
+		found = false;
+		for (j=0; j<discdevs->len; j++) {
+			priv = __device_priv(discdevs->devices[j]);
+
+			if (priv->parent_dev == NULL) {
+				continue;	// ignore HCDs
+			}
+
+			parent_priv = __device_priv(priv->parent_dev);
+
+			// NB: we compare strings of different lengths below => strncmp
+			if ( (safe_strncmp(parent_priv->path, sanitized_path, safe_strlen(sanitized_path)) == 0)
+			  && (port_nr == priv->connection_index) ) {
+
+				priv->path = sanitize_path(dev_interface_details->DevicePath);
+
+				usbi_dbg("path (%d:%d): %s", discdevs->devices[j]->bus_number,
+					discdevs->devices[j]->device_address, priv->path);
+
+				// Check the service & filter names to know the API we should use
+				for (k=0; k<3; k++) {
+					if (SetupDiGetDeviceRegistryPropertyA(dev_info, &dev_info_data, lookup[k].reg_prop,
+						&reg_type, (BYTE*)lookup[k].list, MAX_KEY_LENGTH, &size)) {
+						// Turn the REG_SZ SPDRP_SERVICE into REG_MULTI_SZ
+						if (lookup[k].reg_prop == SPDRP_SERVICE) {
+							// our buffers are MAX_KEY_LENGTH+1 so we can overflow if needed
+							lookup[k].list[safe_strlen(lookup[k].list)+1] = 0;
+						}
+						// MULTI_SZ is a pain to work with. Turn it into something much more manageable
+						// NB: none of the driver names we check against contain LIST_SEPARATOR,
+						// (currently ';'), so even if an unsuported one does, it's not an issue
+						for (l=0; (lookup[k].list[l] != 0) || (lookup[k].list[l+1] != 0); l++) {
+							if (lookup[k].list[l] == 0) {
+								lookup[k].list[l] = LIST_SEPARATOR;
+							}
+						}
+						upperize(lookup[k].list);
+						usbi_dbg("%s(s): %s", lookup[k].designation, lookup[k].list);
+						found = true;
+					} else {
+						if (GetLastError() != ERROR_INVALID_DATA) {
+							usbi_dbg("could not access %s: %s", lookup[k].designation, windows_error_str(0));
+						}
+						lookup[k].list[0] = 0;
+					}
+				}
+
+				for (api=0; api<USB_API_MAX; api++) {
+					for (k=0; k<3; k++) {
+						if (is_api_driver(lookup[k].list, api)) {
+							usbi_dbg("matched %s name against %s", lookup[k].designation, usb_api_backend[api].designation);
+							break;
+						}
+					}
+					if (k >= 3) continue;
+					priv->apib = &usb_api_backend[api];
+					switch(api) {
+					case USB_API_COMPOSITE:
+						set_composite_device(ctx, dev_info_data.DevInst, priv);
+						break;
+					case USB_API_HID:
+						safe_free(priv->hid);
+						priv->hid = calloc(1, sizeof(struct hid_device_priv));
+						if (priv->hid == NULL) {
+							usbi_err(ctx, "could not allocate HID data for %s, skipping",
+								dev_interface_details->DevicePath);
+							priv->apib = &usb_api_backend[USB_API_UNSUPPORTED];
+							safe_free(priv->path);
+						} else {
+							set_hid_device(ctx, priv);
+						}
+						break;
+					default:
+						// For other devices, the first interface is the same as the device
+						priv->usb_interface[0].path = malloc(safe_strlen(priv->path)+1);
+						if (priv->usb_interface[0].path != NULL) {
+							safe_strcpy(priv->usb_interface[0].path, safe_strlen(priv->path)+1, priv->path);
+						}
+						// The following is needed if we want to API calls to work for both simple
+						// and composite devices, as
+						for(k=0; k<USB_MAXINTERFACES; k++) {
+							priv->usb_interface[k].apib = &usb_api_backend[api];
+						}
+						break;
+					}
+				}
+				break;
+			}
+		}
+		if (!found) {
+			usbi_warn(ctx, "could not match %s with a libusb device.", dev_interface_details->DevicePath);
+			continue;
+		}
+	}
+
+	return LIBUSB_SUCCESS;
+}
+
+/*
+ * get_device_list: libusb backend device enumeration function
+ */
+static int windows_get_device_list(struct libusb_context *ctx, struct discovered_devs **_discdevs)
+{
+	struct windows_hcd_priv* hcd;
+	HANDLE handle = INVALID_HANDLE_VALUE;
+	int r = LIBUSB_SUCCESS;
+	libusb_bus_t bus;
+
+	// Use the index of the HCD in the chained list as bus #
+	for (hcd = hcd_root, bus = 0; ; hcd = hcd->next, bus++)
+	{
+		safe_closehandle(handle);
+
+		if ( (hcd == NULL) || (r != LIBUSB_SUCCESS) )
+			break;
+
+		if (bus == LIBUSB_BUS_MAX) {
+			usbi_warn(ctx, "program assertion failed - got more than %d buses, skipping the rest.", LIBUSB_BUS_MAX);
+			continue;
+		}
+
+		handle = CreateFileA(hcd->path, GENERIC_WRITE, FILE_SHARE_WRITE,
+			NULL, OPEN_EXISTING, FILE_FLAG_OVERLAPPED, NULL);
+		if (handle == INVALID_HANDLE_VALUE) {
+			usbi_warn(ctx, "could not open bus %u, skipping: %s", bus, windows_error_str(0));
+			continue;
+		}
+
+		LOOP_CHECK(usb_enumerate_hub(ctx, _discdevs, handle, bus, NULL, 1));
+	}
+
+	// Set the interface path for non-hubs
+	r = set_device_paths(ctx, *_discdevs);
+
+	return r;
+}
+
+/*
+ * exit: libusb backend deinitialization function
+ */
+static void windows_exit(void)
+{
+	struct windows_hcd_priv* hcd_tmp;
+	int i;
+	HANDLE semaphore;
+	TCHAR sem_name[11+1+8]; // strlen(libusb_init)+'\0'+(32-bit hex PID)
+
+	sprintf(sem_name, "libusb_init%08X", (unsigned int)GetCurrentProcessId()&0xFFFFFFFF);
+	semaphore = CreateSemaphore(NULL, 1, 1, sem_name);
+	if (semaphore == NULL) {
+		return;
+	}
+
+	// A successful wait brings our semaphore count to 0 (unsignaled)
+	// => any concurent wait stalls until the semaphore release
+	if (WaitForSingleObject(semaphore, INFINITE) != WAIT_OBJECT_0) {
+		CloseHandle(semaphore);
+		return;
+	}
+
+	// Only works if exits and inits are balanced exactly
+	if (--concurrent_usage < 0) {	// Last exit
+		while (hcd_root != NULL)
+		{
+			hcd_tmp = hcd_root;	// Keep a copy for free
+			hcd_root = hcd_root->next;
+			windows_hcd_priv_release(hcd_tmp);
+			safe_free(hcd_tmp);
+		}
+
+		for (i=0; i<USB_API_MAX; i++) {
+			usb_api_backend[i].exit();
+		}
+		exit_polling();
+
+		if (timer_thread) {
+			SetEvent(timer_request[1]); // actually the signal to quit the thread.
+			if (WAIT_OBJECT_0 != WaitForSingleObject(timer_thread, INFINITE)) {
+				usbi_dbg("could not wait for timer thread to quit");
+				TerminateThread(timer_thread, 1);
+			}
+			CloseHandle(timer_thread);
+			timer_thread = NULL;
+		}
+		for (i = 0; i < 2; i++) {
+			if (timer_request[i]) {
+				CloseHandle(timer_request[i]);
+				timer_request[i] = NULL;
+			}
+		}
+		if (timer_response) {
+			CloseHandle(timer_response);
+			timer_response = NULL;
+		}
+		if (timer_mutex) {
+			CloseHandle(timer_mutex);
+			timer_mutex = NULL;
+		}
+	}
+
+	ReleaseSemaphore(semaphore, 1, NULL);	// increase count back to 1
+	CloseHandle(semaphore);
+}
+
+static int windows_get_device_descriptor(struct libusb_device *dev, unsigned char *buffer, int *host_endian)
+{
+	struct windows_device_priv *priv = __device_priv(dev);
+
+	memcpy(buffer, &(priv->dev_descriptor), DEVICE_DESC_LENGTH);
+	*host_endian = 0;
+
+	return LIBUSB_SUCCESS;
+}
+
+static int windows_get_config_descriptor(struct libusb_device *dev, uint8_t config_index, unsigned char *buffer, size_t len, int *host_endian)
+{
+	struct windows_device_priv *priv = __device_priv(dev);
+	PUSB_CONFIGURATION_DESCRIPTOR config_header;
+	size_t size;
+
+	// config index is zero based
+	if (config_index >= dev->num_configurations)
+		return LIBUSB_ERROR_INVALID_PARAM;
+
+	if ((priv->config_descriptor == NULL) || (priv->config_descriptor[config_index] == NULL))
+		return LIBUSB_ERROR_NOT_FOUND;
+
+	config_header = (PUSB_CONFIGURATION_DESCRIPTOR)priv->config_descriptor[config_index];
+
+	size = min(config_header->wTotalLength, len);
+	memcpy(buffer, priv->config_descriptor[config_index], size);
+
+	return LIBUSB_SUCCESS;
+}
+
+/*
+ * return the cached copy of the active config descriptor
+ */
+static int windows_get_active_config_descriptor(struct libusb_device *dev, unsigned char *buffer, size_t len, int *host_endian)
+{
+	struct windows_device_priv *priv = __device_priv(dev);
+
+	if (priv->active_config == 0)
+		return LIBUSB_ERROR_NOT_FOUND;
+
+	// config index is zero based
+	return windows_get_config_descriptor(dev, (uint8_t)(priv->active_config-1), buffer, len, host_endian);
+}
+
+static int windows_open(struct libusb_device_handle *dev_handle)
+{
+	struct windows_device_priv *priv = __device_priv(dev_handle->dev);
+	struct libusb_context *ctx = DEVICE_CTX(dev_handle->dev);
+
+	if (priv->apib == NULL) {
+		usbi_err(ctx, "program assertion failed - device is not initialized");
+		return LIBUSB_ERROR_NO_DEVICE;
+	}
+
+	return priv->apib->open(dev_handle);
+}
+
+static void windows_close(struct libusb_device_handle *dev_handle)
+{
+	struct windows_device_priv *priv = __device_priv(dev_handle->dev);
+
+	priv->apib->close(dev_handle);
+}
+
+static int windows_get_configuration(struct libusb_device_handle *dev_handle, int *config)
+{
+	struct windows_device_priv *priv = __device_priv(dev_handle->dev);
+
+	if (priv->active_config == 0) {
+		*config = 0;
+		return LIBUSB_ERROR_NOT_FOUND;
+	}
+
+	*config = priv->active_config;
+	return LIBUSB_SUCCESS;
+}
+
+/*
+ * from http://msdn.microsoft.com/en-us/library/ms793522.aspx: "The port driver
+ * does not currently expose a service that allows higher-level drivers to set
+ * the configuration."
+ */
+static int windows_set_configuration(struct libusb_device_handle *dev_handle, int config)
+{
+	struct windows_device_priv *priv = __device_priv(dev_handle->dev);
+	int r = LIBUSB_SUCCESS;
+
+	if (config >= USB_MAXCONFIG)
+		return LIBUSB_ERROR_INVALID_PARAM;
+
+	r = libusb_control_transfer(dev_handle, LIBUSB_ENDPOINT_OUT |
+		LIBUSB_REQUEST_TYPE_STANDARD | LIBUSB_RECIPIENT_DEVICE,
+		LIBUSB_REQUEST_SET_CONFIGURATION, (uint16_t)config,
+		0, NULL, 0, 1000);
+
+	if (r == LIBUSB_SUCCESS) {
+		priv->active_config = (uint8_t)config;
+	}
+	return r;
+}
+
+static int windows_claim_interface(struct libusb_device_handle *dev_handle, int iface)
+{
+	int r = LIBUSB_SUCCESS;
+	struct windows_device_priv *priv = __device_priv(dev_handle->dev);
+
+	if (iface >= USB_MAXINTERFACES)
+		return LIBUSB_ERROR_INVALID_PARAM;
+
+	safe_free(priv->usb_interface[iface].endpoint);
+	priv->usb_interface[iface].nb_endpoints= 0;
+
+	r = priv->apib->claim_interface(dev_handle, iface);
+
+	if (r == LIBUSB_SUCCESS) {
+		r = windows_assign_endpoints(dev_handle->dev, iface, 0);
+	}
+
+	return r;
+}
+
+static int windows_set_interface_altsetting(struct libusb_device_handle *dev_handle, int iface, int altsetting)
+{
+	int r = LIBUSB_SUCCESS;
+	struct windows_device_priv *priv = __device_priv(dev_handle->dev);
+
+	safe_free(priv->usb_interface[iface].endpoint);
+	priv->usb_interface[iface].nb_endpoints= 0;
+
+	r = priv->apib->set_interface_altsetting(dev_handle, iface, altsetting);
+
+	if (r == LIBUSB_SUCCESS) {
+		r = windows_assign_endpoints(dev_handle->dev, iface, altsetting);
+	}
+
+	return r;
+}
+
+static int windows_release_interface(struct libusb_device_handle *dev_handle, int iface)
+{
+	struct windows_device_priv *priv = __device_priv(dev_handle->dev);
+
+	windows_set_interface_altsetting(dev_handle, iface, 0);
+	return priv->apib->release_interface(dev_handle, iface);
+}
+
+static int windows_clear_halt(struct libusb_device_handle *dev_handle, unsigned char endpoint)
+{
+	struct windows_device_priv *priv = __device_priv(dev_handle->dev);
+	return priv->apib->clear_halt(dev_handle, endpoint);
+}
+
+static int windows_reset_device(struct libusb_device_handle *dev_handle)
+{
+	struct windows_device_priv *priv = __device_priv(dev_handle->dev);
+	return priv->apib->reset_device(dev_handle);
+}
+
+// The 3 functions below are unlikely to ever get supported on Windows
+static int windows_kernel_driver_active(struct libusb_device_handle *dev_handle, int iface)
+{
+	return LIBUSB_ERROR_NOT_SUPPORTED;
+}
+
+static int windows_attach_kernel_driver(struct libusb_device_handle *dev_handle, int iface)
+{
+	return LIBUSB_ERROR_NOT_SUPPORTED;
+}
+
+static int windows_detach_kernel_driver(struct libusb_device_handle *dev_handle, int iface)
+{
+	return LIBUSB_ERROR_NOT_SUPPORTED;
+}
+
+static void windows_destroy_device(struct libusb_device *dev)
+{
+	struct windows_device_priv *priv = __device_priv(dev);
+	windows_device_priv_release(priv, dev->num_configurations);
+}
+
+static void windows_clear_transfer_priv(struct usbi_transfer *itransfer)
+{
+	struct windows_transfer_priv *transfer_priv = usbi_transfer_get_os_priv(itransfer);
+
+	usbi_free_fd(transfer_priv->pollable_fd.fd);
+	safe_free(transfer_priv->hid_buffer);
+#if defined(AUTO_CLAIM)
+	// When auto claim is in use, attempt to release the auto-claimed interface
+	auto_release(itransfer);
+#endif
+}
+
+static int submit_bulk_transfer(struct usbi_transfer *itransfer)
+{
+	struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct libusb_context *ctx = DEVICE_CTX(transfer->dev_handle->dev);
+	struct windows_transfer_priv *transfer_priv = usbi_transfer_get_os_priv(itransfer);
+	struct windows_device_priv *priv = __device_priv(transfer->dev_handle->dev);
+	int r;
+
+	r = priv->apib->submit_bulk_transfer(itransfer);
+	if (r != LIBUSB_SUCCESS) {
+		return r;
+	}
+
+	usbi_add_pollfd(ctx, transfer_priv->pollable_fd.fd,
+		(short)((transfer->endpoint & LIBUSB_ENDPOINT_IN)?POLLIN:POLLOUT));
+#if !defined(DYNAMIC_FDS)
+	usbi_fd_notification(ctx);
+#endif
+
+	return LIBUSB_SUCCESS;
+}
+
+static int submit_iso_transfer(struct usbi_transfer *itransfer)
+{
+	struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct libusb_context *ctx = DEVICE_CTX(transfer->dev_handle->dev);
+	struct windows_transfer_priv *transfer_priv = usbi_transfer_get_os_priv(itransfer);
+	struct windows_device_priv *priv = __device_priv(transfer->dev_handle->dev);
+	int r;
+
+	r = priv->apib->submit_iso_transfer(itransfer);
+	if (r != LIBUSB_SUCCESS) {
+		return r;
+	}
+
+	usbi_add_pollfd(ctx, transfer_priv->pollable_fd.fd,
+		(short)((transfer->endpoint & LIBUSB_ENDPOINT_IN)?POLLIN:POLLOUT));
+#if !defined(DYNAMIC_FDS)
+	usbi_fd_notification(ctx);
+#endif
+
+	return LIBUSB_SUCCESS;
+}
+
+static int submit_control_transfer(struct usbi_transfer *itransfer)
+{
+	struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct libusb_context *ctx = DEVICE_CTX(transfer->dev_handle->dev);
+	struct windows_transfer_priv *transfer_priv = usbi_transfer_get_os_priv(itransfer);
+	struct windows_device_priv *priv = __device_priv(transfer->dev_handle->dev);
+	int r;
+
+	r = priv->apib->submit_control_transfer(itransfer);
+	if (r != LIBUSB_SUCCESS) {
+		return r;
+	}
+
+	usbi_add_pollfd(ctx, transfer_priv->pollable_fd.fd, POLLIN);
+#if !defined(DYNAMIC_FDS)
+	usbi_fd_notification(ctx);
+#endif
+
+	return LIBUSB_SUCCESS;
+
+}
+
+static int windows_submit_transfer(struct usbi_transfer *itransfer)
+{
+	struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+
+	switch (transfer->type) {
+	case LIBUSB_TRANSFER_TYPE_CONTROL:
+		return submit_control_transfer(itransfer);
+	case LIBUSB_TRANSFER_TYPE_BULK:
+	case LIBUSB_TRANSFER_TYPE_INTERRUPT:
+		return submit_bulk_transfer(itransfer);
+	case LIBUSB_TRANSFER_TYPE_ISOCHRONOUS:
+		return submit_iso_transfer(itransfer);
+	default:
+		usbi_err(TRANSFER_CTX(transfer), "unknown endpoint type %d", transfer->type);
+		return LIBUSB_ERROR_INVALID_PARAM;
+	}
+}
+
+static int windows_abort_control(struct usbi_transfer *itransfer)
+{
+	struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct windows_device_priv *priv = __device_priv(transfer->dev_handle->dev);
+
+	return priv->apib->abort_control(itransfer);
+}
+
+static int windows_abort_transfers(struct usbi_transfer *itransfer)
+{
+	struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct windows_device_priv *priv = __device_priv(transfer->dev_handle->dev);
+
+	return priv->apib->abort_transfers(itransfer);
+}
+
+static int windows_cancel_transfer(struct usbi_transfer *itransfer)
+{
+	struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+#if defined(FORCE_INSTANT_TIMEOUTS)
+	struct windows_transfer_priv *transfer_priv = usbi_transfer_get_os_priv(itransfer);
+
+	// Forces instant overlapped completion on timeouts - use at your own risks
+	if (itransfer->flags & USBI_TRANSFER_TIMED_OUT) {
+		transfer_priv->pollable_fd.overlapped->Internal &= ~STATUS_PENDING;
+	}
+#endif
+	switch (transfer->type) {
+	case LIBUSB_TRANSFER_TYPE_CONTROL:
+		return windows_abort_control(itransfer);
+	case LIBUSB_TRANSFER_TYPE_BULK:
+	case LIBUSB_TRANSFER_TYPE_INTERRUPT:
+	case LIBUSB_TRANSFER_TYPE_ISOCHRONOUS:
+		return windows_abort_transfers(itransfer);
+	default:
+		usbi_err(ITRANSFER_CTX(itransfer), "unknown endpoint type %d", transfer->type);
+		return LIBUSB_ERROR_INVALID_PARAM;
+	}
+}
+
+static void windows_transfer_callback(struct usbi_transfer *itransfer, uint32_t io_result, uint32_t io_size)
+{
+	struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct windows_device_priv *priv = __device_priv(transfer->dev_handle->dev);
+	int status;
+
+	usbi_dbg("handling I/O completion with errcode %d", io_result);
+
+	switch(io_result) {
+	case NO_ERROR:
+		status = priv->apib->copy_transfer_data(itransfer, io_size);
+		break;
+	case ERROR_GEN_FAILURE:
+		usbi_dbg("detected endpoint stall");
+		status = LIBUSB_TRANSFER_STALL;
+		break;
+	case ERROR_SEM_TIMEOUT:
+		usbi_dbg("detected semaphore timeout");
+		status = LIBUSB_TRANSFER_TIMED_OUT;
+		break;
+	case ERROR_OPERATION_ABORTED:
+		if (itransfer->flags & USBI_TRANSFER_TIMED_OUT) {
+			usbi_dbg("detected timeout");
+			status = LIBUSB_TRANSFER_TIMED_OUT;
+		} else {
+			usbi_dbg("detected operation aborted");
+			status = LIBUSB_TRANSFER_CANCELLED;
+		}
+		break;
+	default:
+		usbi_err(ITRANSFER_CTX(itransfer), "detected I/O error: %s", windows_error_str(0));
+		status = LIBUSB_TRANSFER_ERROR;
+		break;
+	}
+	windows_clear_transfer_priv(itransfer);	// Cancel polling
+	usbi_handle_transfer_completion(itransfer, status);
+}
+
+static void windows_handle_callback (struct usbi_transfer *itransfer, uint32_t io_result, uint32_t io_size)
+{
+	struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+
+	switch (transfer->type) {
+	case LIBUSB_TRANSFER_TYPE_CONTROL:
+	case LIBUSB_TRANSFER_TYPE_BULK:
+	case LIBUSB_TRANSFER_TYPE_INTERRUPT:
+	case LIBUSB_TRANSFER_TYPE_ISOCHRONOUS:
+		windows_transfer_callback (itransfer, io_result, io_size);
+		break;
+	default:
+		usbi_err(ITRANSFER_CTX(itransfer), "unknown endpoint type %d", transfer->type);
+	}
+}
+
+static int windows_handle_events(struct libusb_context *ctx, struct pollfd *fds, nfds_t nfds, int num_ready)
+{
+	struct windows_transfer_priv* transfer_priv = NULL;
+	nfds_t i = 0;
+	bool found = false;
+	struct usbi_transfer *transfer;
+	DWORD io_size, io_result;
+
+	usbi_mutex_lock(&ctx->open_devs_lock);
+	for (i = 0; i < nfds && num_ready > 0; i++) {
+
+		usbi_dbg("checking fd %d with revents = %04x", fds[i].fd, fds[i].revents);
+
+		if (!fds[i].revents) {
+			continue;
+		}
+
+		num_ready--;
+
+		// Because a Windows OVERLAPPED is used for poll emulation,
+		// a pollable fd is created and stored with each transfer
+		usbi_mutex_lock(&ctx->flying_transfers_lock);
+		list_for_each_entry(transfer, &ctx->flying_transfers, list, struct usbi_transfer) {
+			transfer_priv = usbi_transfer_get_os_priv(transfer);
+			if (transfer_priv->pollable_fd.fd == fds[i].fd) {
+				found = true;
+				break;
+			}
+		}
+		usbi_mutex_unlock(&ctx->flying_transfers_lock);
+
+		if (found) {
+			// Handle async requests that completed synchronously first
+			if (HasOverlappedIoCompletedSync(transfer_priv->pollable_fd.overlapped)) {
+				io_result = NO_ERROR;
+				io_size = (DWORD)transfer_priv->pollable_fd.overlapped->InternalHigh;
+			// Regular async overlapped
+			} else if (GetOverlappedResult(transfer_priv->pollable_fd.handle,
+				transfer_priv->pollable_fd.overlapped, &io_size, false)) {
+				io_result = NO_ERROR;
+			} else {
+				io_result = GetLastError();
+			}
+			usbi_remove_pollfd(ctx, transfer_priv->pollable_fd.fd);
+			// let handle_callback free the event using the transfer wfd
+			// If you don't use the transfer wfd, you run a risk of trying to free a
+			// newly allocated wfd that took the place of the one from the transfer.
+			windows_handle_callback(transfer, io_result, io_size);
+		} else {
+			usbi_err(ctx, "could not find a matching transfer for fd %x", fds[i]);
+			return LIBUSB_ERROR_NOT_FOUND;
+		}
+	}
+
+	usbi_mutex_unlock(&ctx->open_devs_lock);
+	return LIBUSB_SUCCESS;
+}
+
+/*
+ * Monotonic and real time functions
+ */
+unsigned __stdcall windows_clock_gettime_threaded(void* param)
+{
+	LARGE_INTEGER hires_counter, li_frequency;
+	LONG nb_responses;
+	int timer_index;
+
+	// Init - find out if we have access to a monotonic (hires) timer
+	if (!QueryPerformanceFrequency(&li_frequency)) {
+		usbi_dbg("no hires timer available on this platform");
+		hires_frequency = 0;
+		hires_ticks_to_ps = UINT64_C(0);
+	} else {
+		hires_frequency = li_frequency.QuadPart;
+		// The hires frequency can go as high as 4 GHz, so we'll use a conversion
+		// to picoseconds to compute the tv_nsecs part in clock_gettime
+		hires_ticks_to_ps = UINT64_C(1000000000000) / hires_frequency;
+		usbi_dbg("hires timer available (Frequency: %"PRIu64" Hz)", hires_frequency);
+	}
+
+	// Main loop - wait for requests
+	while (1) {
+		timer_index = WaitForMultipleObjects(2, timer_request, FALSE, INFINITE) - WAIT_OBJECT_0;
+		if ( (timer_index != 0) && (timer_index != 1) ) {
+			usbi_dbg("failure to wait on requests: %s", windows_error_str(0));
+			continue;
+		}
+		if (request_count[timer_index] == 0) {
+			// Request already handled
+			ResetEvent(timer_request[timer_index]);
+			// There's still a possiblity that a thread sends a request between the
+			// time we test request_count[] == 0 and we reset the event, in which case
+			// the request would be ignored. The simple solution to that is to test
+			// request_count again and process requests if non zero.
+			if (request_count[timer_index] == 0)
+				continue;
+		}
+		switch (timer_index) {
+		case 0:
+			WaitForSingleObject(timer_mutex, INFINITE);
+			// Requests to this thread are for hires always
+			if (QueryPerformanceCounter(&hires_counter) != 0) {
+				timer_tp.tv_sec = (long)(hires_counter.QuadPart / hires_frequency);
+				timer_tp.tv_nsec = (long)(((hires_counter.QuadPart % hires_frequency)/1000) * hires_ticks_to_ps);
+			} else {
+				// Fallback to real-time if we can't get monotonic value
+				// Note that real-time clock does not wait on the mutex or this thread.
+				windows_clock_gettime(USBI_CLOCK_REALTIME, &timer_tp);
+			}
+			ReleaseMutex(timer_mutex);
+
+			nb_responses = InterlockedExchange((LONG*)&request_count[0], 0);
+			if ( (nb_responses)
+			  && (ReleaseSemaphore(timer_response, nb_responses, NULL) == 0) ) {
+				usbi_dbg("unable to release timer semaphore %d: %s", windows_error_str(0));
+			}
+			continue;
+		case 1: // time to quit
+			usbi_dbg("timer thread quitting");
+			return 0;
+		}
+	}
+	usbi_dbg("ERROR: broken timer thread");
+	return 1;
+}
+
+static int windows_clock_gettime(int clk_id, struct timespec *tp)
+{
+	FILETIME filetime;
+	ULARGE_INTEGER rtime;
+	DWORD r;
+	switch(clk_id) {
+	case USBI_CLOCK_MONOTONIC:
+		if (hires_frequency != 0) {
+			while (1) {
+				InterlockedIncrement((LONG*)&request_count[0]);
+				SetEvent(timer_request[0]);
+				r = WaitForSingleObject(timer_response, TIMER_REQUEST_RETRY_MS);
+				switch(r) {
+				case WAIT_OBJECT_0:
+					WaitForSingleObject(timer_mutex, INFINITE);
+					*tp = timer_tp;
+					ReleaseMutex(timer_mutex);
+					return LIBUSB_SUCCESS;
+				case WAIT_TIMEOUT:
+					usbi_dbg("could not obtain a timer value within reasonable timeframe - too much load?");
+					break; // Retry until successful
+				default:
+					usbi_dbg("WaitForSingleObject failed: %s", windows_error_str(0));
+					return LIBUSB_ERROR_OTHER;
+				}
+			}
+		}
+		// Fall through and return real-time if monotonic was not detected @ timer init
+	case USBI_CLOCK_REALTIME:
+		// We follow http://msdn.microsoft.com/en-us/library/ms724928%28VS.85%29.aspx
+		// with a predef epoch_time to have an epoch that starts at 1970.01.01 00:00
+		// Note however that our resolution is bounded by the Windows system time
+		// functions and is at best of the order of 1 ms (or, usually, worse)
+		GetSystemTimeAsFileTime(&filetime);
+		rtime.LowPart = filetime.dwLowDateTime;
+		rtime.HighPart = filetime.dwHighDateTime;
+		rtime.QuadPart -= epoch_time;
+		tp->tv_sec = (long)(rtime.QuadPart / 10000000);
+		tp->tv_nsec = (long)((rtime.QuadPart % 10000000)*100);
+		return LIBUSB_SUCCESS;
+	default:
+		return LIBUSB_ERROR_INVALID_PARAM;
+	}
+}
+
+
+// NB: MSVC6 does not support named initializers.
+const struct usbi_os_backend windows_backend = {
+	"Windows",
+	windows_init,
+	windows_exit,
+
+	windows_get_device_list,
+	windows_open,
+	windows_close,
+
+	windows_get_device_descriptor,
+	windows_get_active_config_descriptor,
+	windows_get_config_descriptor,
+
+	windows_get_configuration,
+	windows_set_configuration,
+	windows_claim_interface,
+	windows_release_interface,
+
+	windows_set_interface_altsetting,
+	windows_clear_halt,
+	windows_reset_device,
+
+	windows_kernel_driver_active,
+	windows_detach_kernel_driver,
+	windows_attach_kernel_driver,
+
+	windows_destroy_device,
+
+	windows_submit_transfer,
+	windows_cancel_transfer,
+	windows_clear_transfer_priv,
+
+	windows_handle_events,
+
+	windows_clock_gettime,
+#if defined(USBI_TIMERFD_AVAILABLE)
+	NULL,
+#endif
+	sizeof(struct windows_device_priv),
+	sizeof(struct windows_device_handle_priv),
+	sizeof(struct windows_transfer_priv),
+	0,
+};
+
+
+/*
+ * USB API backends
+ */
+static int unsupported_init(struct libusb_context *ctx) {
+	return LIBUSB_SUCCESS;
+}
+static int unsupported_exit(void) {
+	return LIBUSB_SUCCESS;
+}
+static int unsupported_open(struct libusb_device_handle *dev_handle) {
+	PRINT_UNSUPPORTED_API(open);
+}
+static void unsupported_close(struct libusb_device_handle *dev_handle) {
+	usbi_dbg("unsupported API call for 'close'");
+}
+static int unsupported_claim_interface(struct libusb_device_handle *dev_handle, int iface) {
+	PRINT_UNSUPPORTED_API(claim_interface);
+}
+static int unsupported_set_interface_altsetting(struct libusb_device_handle *dev_handle, int iface, int altsetting) {
+	PRINT_UNSUPPORTED_API(set_interface_altsetting);
+}
+static int unsupported_release_interface(struct libusb_device_handle *dev_handle, int iface) {
+	PRINT_UNSUPPORTED_API(release_interface);
+}
+static int unsupported_clear_halt(struct libusb_device_handle *dev_handle, unsigned char endpoint) {
+	PRINT_UNSUPPORTED_API(clear_halt);
+}
+static int unsupported_reset_device(struct libusb_device_handle *dev_handle) {
+	PRINT_UNSUPPORTED_API(reset_device);
+}
+static int unsupported_submit_bulk_transfer(struct usbi_transfer *itransfer) {
+	PRINT_UNSUPPORTED_API(submit_bulk_transfer);
+}
+static int unsupported_submit_iso_transfer(struct usbi_transfer *itransfer) {
+	PRINT_UNSUPPORTED_API(submit_iso_transfer);
+}
+static int unsupported_submit_control_transfer(struct usbi_transfer *itransfer) {
+	PRINT_UNSUPPORTED_API(submit_control_transfer);
+}
+static int unsupported_abort_control(struct usbi_transfer *itransfer) {
+	PRINT_UNSUPPORTED_API(abort_control);
+}
+static int unsupported_abort_transfers(struct usbi_transfer *itransfer) {
+	PRINT_UNSUPPORTED_API(abort_transfers);
+}
+static int unsupported_copy_transfer_data(struct usbi_transfer *itransfer, uint32_t io_size) {
+	PRINT_UNSUPPORTED_API(copy_transfer_data);
+}
+
+// These names must be uppercase
+const char* composite_driver_names[] = {"USBCCGP"};
+const char* winusb_driver_names[] = {"WINUSB"};
+const char* hid_driver_names[] = {"HIDUSB", "MOUHID", "KBDHID"};
+const struct windows_usb_api_backend usb_api_backend[USB_API_MAX] = {
+	{
+		USB_API_UNSUPPORTED,
+		"Unsupported API",
+		&CLASS_GUID_UNSUPPORTED,
+		NULL,
+		0,
+		unsupported_init,
+		unsupported_exit,
+		unsupported_open,
+		unsupported_close,
+		unsupported_claim_interface,
+		unsupported_set_interface_altsetting,
+		unsupported_release_interface,
+		unsupported_clear_halt,
+		unsupported_reset_device,
+		unsupported_submit_bulk_transfer,
+		unsupported_submit_iso_transfer,
+		unsupported_submit_control_transfer,
+		unsupported_abort_control,
+		unsupported_abort_transfers,
+		unsupported_copy_transfer_data,
+	}, {
+		USB_API_COMPOSITE,
+		"Composite API",
+		&CLASS_GUID_COMPOSITE,
+		composite_driver_names,
+		sizeof(composite_driver_names)/sizeof(composite_driver_names[0]),
+		composite_init,
+		composite_exit,
+		composite_open,
+		composite_close,
+		composite_claim_interface,
+		composite_set_interface_altsetting,
+		composite_release_interface,
+		composite_clear_halt,
+		composite_reset_device,
+		composite_submit_bulk_transfer,
+		composite_submit_iso_transfer,
+		composite_submit_control_transfer,
+		composite_abort_control,
+		composite_abort_transfers,
+		composite_copy_transfer_data,
+	}, {
+		USB_API_WINUSB,
+		"WinUSB API",
+		&CLASS_GUID_LIBUSB_WINUSB,
+		winusb_driver_names,
+		sizeof(winusb_driver_names)/sizeof(winusb_driver_names[0]),
+		winusb_init,
+		winusb_exit,
+		winusb_open,
+		winusb_close,
+		winusb_claim_interface,
+		winusb_set_interface_altsetting,
+		winusb_release_interface,
+		winusb_clear_halt,
+		winusb_reset_device,
+		winusb_submit_bulk_transfer,
+		unsupported_submit_iso_transfer,
+		winusb_submit_control_transfer,
+		winusb_abort_control,
+		winusb_abort_transfers,
+		winusb_copy_transfer_data,
+	}, {
+		USB_API_HID,
+		"HID API",
+		&CLASS_GUID_HID,
+		hid_driver_names,
+		sizeof(hid_driver_names)/sizeof(hid_driver_names[0]),
+		hid_init,
+		hid_exit,
+		hid_open,
+		hid_close,
+		hid_claim_interface,
+		hid_set_interface_altsetting,
+		hid_release_interface,
+		hid_clear_halt,
+		hid_reset_device,
+		hid_submit_bulk_transfer,
+		unsupported_submit_iso_transfer,
+		hid_submit_control_transfer,
+		hid_abort_transfers,
+		hid_abort_transfers,
+		hid_copy_transfer_data,
+	},
+};
+
+
+/*
+ * WinUSB API functions
+ */
+static int winusb_init(struct libusb_context *ctx)
+{
+	DLL_LOAD(winusb.dll, WinUsb_Initialize, TRUE);
+	DLL_LOAD(winusb.dll, WinUsb_Free, TRUE);
+	DLL_LOAD(winusb.dll, WinUsb_GetAssociatedInterface, TRUE);
+	DLL_LOAD(winusb.dll, WinUsb_GetDescriptor, TRUE);
+	DLL_LOAD(winusb.dll, WinUsb_QueryInterfaceSettings, TRUE);
+	DLL_LOAD(winusb.dll, WinUsb_QueryDeviceInformation, TRUE);
+	DLL_LOAD(winusb.dll, WinUsb_SetCurrentAlternateSetting, TRUE);
+	DLL_LOAD(winusb.dll, WinUsb_GetCurrentAlternateSetting, TRUE);
+	DLL_LOAD(winusb.dll, WinUsb_QueryPipe, TRUE);
+	DLL_LOAD(winusb.dll, WinUsb_SetPipePolicy, TRUE);
+	DLL_LOAD(winusb.dll, WinUsb_GetPipePolicy, TRUE);
+	DLL_LOAD(winusb.dll, WinUsb_ReadPipe, TRUE);
+	DLL_LOAD(winusb.dll, WinUsb_WritePipe, TRUE);
+	DLL_LOAD(winusb.dll, WinUsb_ControlTransfer, TRUE);
+	DLL_LOAD(winusb.dll, WinUsb_ResetPipe, TRUE);
+	DLL_LOAD(winusb.dll, WinUsb_AbortPipe, TRUE);
+	DLL_LOAD(winusb.dll, WinUsb_FlushPipe, TRUE);
+
+	api_winusb_available = true;
+	return LIBUSB_SUCCESS;
+}
+
+static int winusb_exit(void)
+{
+	return LIBUSB_SUCCESS;
+}
+
+// NB: open and close must ensure that they only handle interface of
+// the right API type, as these functions can be called wholesale from
+// composite_open(), with interfaces belonging to different APIs
+static int winusb_open(struct libusb_device_handle *dev_handle)
+{
+	struct libusb_context *ctx = DEVICE_CTX(dev_handle->dev);
+	struct windows_device_priv *priv = __device_priv(dev_handle->dev);
+	struct windows_device_handle_priv *handle_priv = __device_handle_priv(dev_handle);
+
+	HANDLE file_handle;
+	int i;
+
+	CHECK_WINUSB_AVAILABLE;
+
+	// WinUSB requires a seperate handle for each interface
+	for (i = 0; i < USB_MAXINTERFACES; i++) {
+		if ( (priv->usb_interface[i].path != NULL)
+		  && (priv->usb_interface[i].apib->id == USB_API_WINUSB) ) {
+			file_handle = CreateFileA(priv->usb_interface[i].path, GENERIC_WRITE | GENERIC_READ, FILE_SHARE_WRITE | FILE_SHARE_READ,
+				NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED, NULL);
+			if (file_handle == INVALID_HANDLE_VALUE) {
+				usbi_err(ctx, "could not open device %s (interface %d): %s", priv->usb_interface[i].path, i, windows_error_str(0));
+				switch(GetLastError()) {
+				case ERROR_FILE_NOT_FOUND:	// The device was disconnected
+					return LIBUSB_ERROR_NO_DEVICE;
+				case ERROR_ACCESS_DENIED:
+					return LIBUSB_ERROR_ACCESS;
+				default:
+					return LIBUSB_ERROR_IO;
+				}
+			}
+			handle_priv->interface_handle[i].dev_handle = file_handle;
+		}
+	}
+
+	return LIBUSB_SUCCESS;
+}
+
+static void winusb_close(struct libusb_device_handle *dev_handle)
+{
+	struct windows_device_handle_priv *handle_priv = __device_handle_priv(dev_handle);
+	struct windows_device_priv *priv = __device_priv(dev_handle->dev);
+	HANDLE file_handle;
+	int i;
+
+	if (!api_winusb_available)
+		return;
+
+	for (i = 0; i < USB_MAXINTERFACES; i++) {
+		if (priv->usb_interface[i].apib->id == USB_API_WINUSB) {
+			file_handle = handle_priv->interface_handle[i].dev_handle;
+			if ( (file_handle != 0) && (file_handle != INVALID_HANDLE_VALUE)) {
+				CloseHandle(file_handle);
+			}
+		}
+	}
+}
+
+static int winusb_claim_interface(struct libusb_device_handle *dev_handle, int iface)
+{
+	struct libusb_context *ctx = DEVICE_CTX(dev_handle->dev);
+	struct windows_device_handle_priv *handle_priv = __device_handle_priv(dev_handle);
+	struct windows_device_priv *priv = __device_priv(dev_handle->dev);
+	bool is_composite = (priv->apib->id == USB_API_COMPOSITE);
+	HANDLE file_handle, winusb_handle;
+	USB_INTERFACE_DESCRIPTOR if_desc;
+	UCHAR policy;
+	uint8_t endpoint_address;
+	int i;
+
+	CHECK_WINUSB_AVAILABLE;
+
+	// interfaces for composite devices are always independent, therefore
+	// "alt" interfaces are only found on non-composite
+	if ((!is_composite) && (iface != 0)) {
+		winusb_handle = handle_priv->interface_handle[0].api_handle;
+		// It is a requirement on Windows that to claim an interface >= 1
+		// on a non-composite WinUSB device, you must first have claimed interface 0
+		if ((winusb_handle == 0) || (winusb_handle == INVALID_HANDLE_VALUE)) {
+#if defined(AUTO_CLAIM)
+			file_handle = handle_priv->interface_handle[0].dev_handle;
+			if (WinUsb_Initialize(file_handle, &winusb_handle)) {
+				handle_priv->interface_handle[0].api_handle = winusb_handle;
+				usbi_warn(ctx, "auto-claimed interface 0 (required to claim %d with WinUSB)", iface);
+			} else {
+				usbi_warn(ctx, "failed to auto-claim interface 0 (required to claim %d with WinUSB)", iface);
+				return LIBUSB_ERROR_ACCESS;
+			}
+#else
+			usbi_warn(ctx, "you must claim interface 0 before you can claim %d with WinUSB", iface);
+			return LIBUSB_ERROR_ACCESS;
+#endif
+		}
+		if (!WinUsb_GetAssociatedInterface(winusb_handle, (UCHAR)(iface-1),
+			&handle_priv->interface_handle[iface].api_handle)) {
+			handle_priv->interface_handle[iface].api_handle = INVALID_HANDLE_VALUE;
+			switch(GetLastError()) {
+			case ERROR_NO_MORE_ITEMS:   // invalid iface
+				return LIBUSB_ERROR_NOT_FOUND;
+			case ERROR_BAD_COMMAND:     // The device was disconnected
+				return LIBUSB_ERROR_NO_DEVICE;
+			case ERROR_ALREADY_EXISTS:  // already claimed
+				return LIBUSB_ERROR_BUSY;
+			default:
+				usbi_err(ctx, "could not claim interface %d: %s", iface, windows_error_str(0));
+				return LIBUSB_ERROR_ACCESS;
+			}
+		}
+	} else {
+		// composite device (independent interfaces) or interface 0
+		winusb_handle = handle_priv->interface_handle[iface].api_handle;
+		file_handle = handle_priv->interface_handle[iface].dev_handle;
+		if ((file_handle == 0) || (file_handle == INVALID_HANDLE_VALUE)) {
+			return LIBUSB_ERROR_NOT_FOUND;
+		}
+
+		if (!WinUsb_Initialize(file_handle, &winusb_handle)) {
+			usbi_err(ctx, "could not access interface %d: %s", iface, windows_error_str(0));
+			handle_priv->interface_handle[iface].api_handle = INVALID_HANDLE_VALUE;
+
+			switch(GetLastError()) {
+			case ERROR_BAD_COMMAND:	// The device was disconnected
+				return LIBUSB_ERROR_NO_DEVICE;
+			default:
+				usbi_err(ctx, "could not claim interface %d: %s", iface, windows_error_str(0));
+				return LIBUSB_ERROR_ACCESS;
+			}
+		}
+		handle_priv->interface_handle[iface].api_handle = winusb_handle;
+	}
+	if (!WinUsb_QueryInterfaceSettings(winusb_handle, 0, &if_desc)) {
+		usbi_err(ctx, "could not query interface settings for interface %d: %s", iface, windows_error_str(0));
+	} else if (if_desc.bInterfaceNumber != iface) {
+		usbi_warn(ctx, "program assertion failed - WinUSB interface %d found at position %d",
+			if_desc.bInterfaceNumber, iface);
+	}
+
+	usbi_dbg("claimed interface %d", iface);
+	handle_priv->active_interface = iface;
+
+	// With handle and enpoints set (in parent), we can setup the default
+	// pipe properties (copied from libusb-win32-v1)
+	// see http://download.microsoft.com/download/D/1/D/D1DD7745-426B-4CC3-A269-ABBBE427C0EF/DVC-T705_DDC08.pptx
+	for (i=0; i<priv->usb_interface[iface].nb_endpoints; i++) {
+		endpoint_address = priv->usb_interface[iface].endpoint[i];
+		policy = false;
+		if (!WinUsb_SetPipePolicy(winusb_handle, endpoint_address,
+			SHORT_PACKET_TERMINATE, sizeof(UCHAR), &policy)) {
+			usbi_dbg("failed to disable SHORT_PACKET_TERMINATE for endpoint %02X", endpoint_address);
+		}
+		if (!WinUsb_SetPipePolicy(winusb_handle, endpoint_address,
+			IGNORE_SHORT_PACKETS, sizeof(UCHAR), &policy)) {
+			usbi_dbg("failed to disable IGNORE_SHORT_PACKETS for endpoint %02X", endpoint_address);
+		}
+		if (!WinUsb_SetPipePolicy(winusb_handle, endpoint_address,
+			ALLOW_PARTIAL_READS, sizeof(UCHAR), &policy)) {
+			usbi_dbg("failed to disable ALLOW_PARTIAL_READS for endpoint %02X", endpoint_address);
+		}
+		policy = true;
+		if (!WinUsb_SetPipePolicy(winusb_handle, endpoint_address,
+			AUTO_CLEAR_STALL, sizeof(UCHAR), &policy)) {
+			usbi_dbg("failed to enable AUTO_CLEAR_STALL for endpoint %02X", endpoint_address);
+		}
+	}
+
+	return LIBUSB_SUCCESS;
+}
+
+static int winusb_release_interface(struct libusb_device_handle *dev_handle, int iface)
+{
+	struct windows_device_handle_priv *handle_priv = __device_handle_priv(dev_handle);
+	HANDLE winusb_handle;
+
+	CHECK_WINUSB_AVAILABLE;
+
+	winusb_handle = handle_priv->interface_handle[iface].api_handle;
+	if ((winusb_handle == 0) || (winusb_handle == INVALID_HANDLE_VALUE)) {
+		return LIBUSB_ERROR_NOT_FOUND;
+	}
+
+	WinUsb_Free(winusb_handle);
+	handle_priv->interface_handle[iface].api_handle = INVALID_HANDLE_VALUE;
+
+	return LIBUSB_SUCCESS;
+}
+
+/*
+ * Return the first valid interface (of the same API type), for control transfers
+ */
+static int get_valid_interface(struct libusb_device_handle *dev_handle, int api_id)
+{
+	struct windows_device_handle_priv *handle_priv = __device_handle_priv(dev_handle);
+	struct windows_device_priv *priv = __device_priv(dev_handle->dev);
+	int i;
+
+	if ((api_id < USB_API_WINUSB) || (api_id > USB_API_HID)) {
+		usbi_dbg("unsupported API ID");
+		return -1;
+	}
+
+	for (i=0; i<USB_MAXINTERFACES; i++) {
+		if ( (handle_priv->interface_handle[i].dev_handle != 0)
+		  && (handle_priv->interface_handle[i].dev_handle != INVALID_HANDLE_VALUE)
+		  && (handle_priv->interface_handle[i].api_handle != 0)
+		  && (handle_priv->interface_handle[i].api_handle != INVALID_HANDLE_VALUE)
+		  && (priv->usb_interface[i].apib == &usb_api_backend[api_id]) ) {
+			return i;
+		}
+	}
+	return -1;
+}
+
+/*
+ * Lookup interface by endpoint address. -1 if not found
+ */
+static int interface_by_endpoint(struct windows_device_priv *priv,
+	struct windows_device_handle_priv *handle_priv, uint8_t endpoint_address)
+{
+	int i, j;
+	for (i=0; i<USB_MAXINTERFACES; i++) {
+		if (handle_priv->interface_handle[i].api_handle == INVALID_HANDLE_VALUE)
+			continue;
+		if (handle_priv->interface_handle[i].api_handle == 0)
+			continue;
+		if (priv->usb_interface[i].endpoint == NULL)
+			continue;
+		for (j=0; j<priv->usb_interface[i].nb_endpoints; j++) {
+			if (priv->usb_interface[i].endpoint[j] == endpoint_address) {
+				return i;
+			}
+		}
+	}
+	return -1;
+}
+
+static int winusb_submit_control_transfer(struct usbi_transfer *itransfer)
+{
+	struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct libusb_context *ctx = DEVICE_CTX(transfer->dev_handle->dev);
+	struct windows_transfer_priv *transfer_priv = usbi_transfer_get_os_priv(itransfer);
+	struct windows_device_handle_priv *handle_priv = __device_handle_priv(
+		transfer->dev_handle);
+	WINUSB_SETUP_PACKET *setup = (WINUSB_SETUP_PACKET *) transfer->buffer;
+	ULONG size;
+	HANDLE winusb_handle;
+	int current_interface;
+	struct winfd wfd;
+
+	CHECK_WINUSB_AVAILABLE;
+
+	transfer_priv->pollable_fd = INVALID_WINFD;
+	size = transfer->length - LIBUSB_CONTROL_SETUP_SIZE;
+
+	if (size > MAX_CTRL_BUFFER_LENGTH)
+		return LIBUSB_ERROR_INVALID_PARAM;
+
+	current_interface = get_valid_interface(transfer->dev_handle, USB_API_WINUSB);
+	if (current_interface < 0) {
+#if defined(AUTO_CLAIM)
+		if (auto_claim(transfer, &current_interface, USB_API_WINUSB) != LIBUSB_SUCCESS) {
+			return LIBUSB_ERROR_NOT_FOUND;
+		}
+#else
+		usbi_warn(ctx, "no interface available for control transfer");
+		return LIBUSB_ERROR_NOT_FOUND;
+#endif
+	}
+
+	usbi_dbg("will use interface %d", current_interface);
+	winusb_handle = handle_priv->interface_handle[current_interface].api_handle;
+
+	wfd = usbi_create_fd(winusb_handle, _O_RDONLY);
+	// Always use the handle returned from usbi_create_fd (wfd.handle)
+	if (wfd.fd < 0) {
+		return LIBUSB_ERROR_NO_MEM;
+	}
+
+	if (!WinUsb_ControlTransfer(wfd.handle, *setup, transfer->buffer + LIBUSB_CONTROL_SETUP_SIZE, size, NULL, wfd.overlapped)) {
+		if(GetLastError() != ERROR_IO_PENDING) {
+			usbi_err(ctx, "WinUsb_ControlTransfer failed: %s", windows_error_str(0));
+			usbi_free_fd(wfd.fd);
+			return LIBUSB_ERROR_IO;
+		}
+	} else {
+		wfd.overlapped->Internal = STATUS_COMPLETED_SYNCHRONOUSLY;
+		wfd.overlapped->InternalHigh = (DWORD)size;
+	}
+
+	// Use priv_transfer to store data needed for async polling
+	transfer_priv->pollable_fd = wfd;
+	transfer_priv->interface_number = (uint8_t)current_interface;
+
+	return LIBUSB_SUCCESS;
+}
+
+static int winusb_set_interface_altsetting(struct libusb_device_handle *dev_handle, int iface, int altsetting)
+{
+	struct libusb_context *ctx = DEVICE_CTX(dev_handle->dev);
+	struct windows_device_handle_priv *handle_priv = __device_handle_priv(dev_handle);
+	HANDLE winusb_handle;
+
+	CHECK_WINUSB_AVAILABLE;
+
+	if (altsetting > 255) {
+		return LIBUSB_ERROR_INVALID_PARAM;
+	}
+
+	winusb_handle = handle_priv->interface_handle[iface].api_handle;
+	if ((winusb_handle == 0) || (winusb_handle == INVALID_HANDLE_VALUE)) {
+		usbi_err(ctx, "interface must be claimed first");
+		return LIBUSB_ERROR_NOT_FOUND;
+	}
+
+	if (!WinUsb_SetCurrentAlternateSetting(winusb_handle, (UCHAR)altsetting)) {
+		usbi_err(ctx, "WinUsb_SetCurrentAlternateSetting failed: %s", windows_error_str(0));
+		return LIBUSB_ERROR_IO;
+	}
+
+	return LIBUSB_SUCCESS;
+}
+
+static int winusb_submit_bulk_transfer(struct usbi_transfer *itransfer)
+{
+	struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct libusb_context *ctx = DEVICE_CTX(transfer->dev_handle->dev);
+	struct windows_transfer_priv *transfer_priv = usbi_transfer_get_os_priv(itransfer);
+	struct windows_device_handle_priv *handle_priv = __device_handle_priv(transfer->dev_handle);
+	struct windows_device_priv *priv = __device_priv(transfer->dev_handle->dev);
+	HANDLE winusb_handle;
+	bool direction_in, ret;
+	int current_interface;
+	struct winfd wfd;
+
+	CHECK_WINUSB_AVAILABLE;
+
+	transfer_priv->pollable_fd = INVALID_WINFD;
+
+	current_interface = interface_by_endpoint(priv, handle_priv, transfer->endpoint);
+	if (current_interface < 0) {
+		usbi_err(ctx, "unable to match endpoint to an open interface - cancelling transfer");
+		return LIBUSB_ERROR_NOT_FOUND;
+	}
+
+	usbi_dbg("matched endpoint %02X with interface %d", transfer->endpoint, current_interface);
+
+	winusb_handle = handle_priv->interface_handle[current_interface].api_handle;
+	direction_in = transfer->endpoint & LIBUSB_ENDPOINT_IN;
+
+	wfd = usbi_create_fd(winusb_handle, direction_in?_O_RDONLY:_O_WRONLY);
+	// Always use the handle returned from usbi_create_fd (wfd.handle)
+	if (wfd.fd < 0) {
+		return LIBUSB_ERROR_NO_MEM;
+	}
+
+	if (direction_in) {
+		usbi_dbg("reading %d bytes", transfer->length);
+		ret = WinUsb_ReadPipe(wfd.handle, transfer->endpoint, transfer->buffer, transfer->length, NULL, wfd.overlapped);
+	} else {
+		usbi_dbg("writing %d bytes", transfer->length);
+		ret = WinUsb_WritePipe(wfd.handle, transfer->endpoint, transfer->buffer, transfer->length, NULL, wfd.overlapped);
+	}
+	if (!ret) {
+		if(GetLastError() != ERROR_IO_PENDING) {
+			usbi_err(ctx, "WinUsb_Pipe Transfer failed: %s", windows_error_str(0));
+			usbi_free_fd(wfd.fd);
+			return LIBUSB_ERROR_IO;
+		}
+	} else {
+		wfd.overlapped->Internal = STATUS_COMPLETED_SYNCHRONOUSLY;
+		wfd.overlapped->InternalHigh = (DWORD)transfer->length;
+	}
+
+	transfer_priv->pollable_fd = wfd;
+	transfer_priv->interface_number = (uint8_t)current_interface;
+
+	return LIBUSB_SUCCESS;
+}
+
+static int winusb_clear_halt(struct libusb_device_handle *dev_handle, unsigned char endpoint)
+{
+	struct libusb_context *ctx = DEVICE_CTX(dev_handle->dev);
+	struct windows_device_handle_priv *handle_priv = __device_handle_priv(dev_handle);
+	struct windows_device_priv *priv = __device_priv(dev_handle->dev);
+	HANDLE winusb_handle;
+	int current_interface;
+
+	CHECK_WINUSB_AVAILABLE;
+
+	current_interface = interface_by_endpoint(priv, handle_priv, endpoint);
+	if (current_interface < 0) {
+		usbi_err(ctx, "unable to match endpoint to an open interface - cannot clear");
+		return LIBUSB_ERROR_NOT_FOUND;
+	}
+
+	usbi_dbg("matched endpoint %02X with interface %d", endpoint, current_interface);
+	winusb_handle = handle_priv->interface_handle[current_interface].api_handle;
+
+	if (!WinUsb_ResetPipe(winusb_handle, endpoint)) {
+		usbi_err(ctx, "WinUsb_ResetPipe failed: %s", windows_error_str(0));
+		return LIBUSB_ERROR_NO_DEVICE;
+	}
+
+	return LIBUSB_SUCCESS;
+}
+
+/*
+ * from http://www.winvistatips.com/winusb-bugchecks-t335323.html (confirmed
+ * through testing as well):
+ * "You can not call WinUsb_AbortPipe on control pipe. You can possibly cancel
+ * the control transfer using CancelIo"
+ */
+static int winusb_abort_control(struct usbi_transfer *itransfer)
+{
+	// Cancelling of the I/O is done in the parent
+	return LIBUSB_SUCCESS;
+}
+
+static int winusb_abort_transfers(struct usbi_transfer *itransfer)
+{
+	struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct libusb_context *ctx = DEVICE_CTX(transfer->dev_handle->dev);
+	struct windows_device_handle_priv *handle_priv = __device_handle_priv(transfer->dev_handle);
+	struct windows_transfer_priv *transfer_priv = usbi_transfer_get_os_priv(itransfer);
+	HANDLE winusb_handle;
+	int current_interface;
+
+	CHECK_WINUSB_AVAILABLE;
+
+	current_interface = transfer_priv->interface_number;
+	if ((current_interface < 0) || (current_interface >= USB_MAXINTERFACES)) {
+		usbi_err(ctx, "program assertion failed: invalid interface_number");
+		return LIBUSB_ERROR_NOT_FOUND;
+	}
+	usbi_dbg("will use interface %d", current_interface);
+
+	winusb_handle = handle_priv->interface_handle[current_interface].api_handle;
+
+	if (!WinUsb_AbortPipe(winusb_handle, transfer->endpoint)) {
+		usbi_err(ctx, "WinUsb_AbortPipe failed: %s", windows_error_str(0));
+		return LIBUSB_ERROR_NO_DEVICE;
+	}
+
+	return LIBUSB_SUCCESS;
+}
+
+/*
+ * from the "How to Use WinUSB to Communicate with a USB Device" Microsoft white paper
+ * (http://www.microsoft.com/whdc/connect/usb/winusb_howto.mspx):
+ * "WinUSB does not support host-initiated reset port and cycle port operations" and
+ * IOCTL_INTERNAL_USB_CYCLE_PORT is only available in kernel mode and the
+ * IOCTL_USB_HUB_CYCLE_PORT ioctl was removed from Vista => the best we can do is
+ * cycle the pipes (and even then, the control pipe can not be reset using WinUSB)
+ */
+// TODO (2nd official release): see if we can force eject the device and redetect it (reuse hotplug?)
+static int winusb_reset_device(struct libusb_device_handle *dev_handle)
+{
+	struct libusb_context *ctx = DEVICE_CTX(dev_handle->dev);
+	struct windows_device_handle_priv *handle_priv = __device_handle_priv(dev_handle);
+	struct windows_device_priv *priv = __device_priv(dev_handle->dev);
+	struct winfd wfd;
+	HANDLE winusb_handle;
+	int i, j;
+
+	CHECK_WINUSB_AVAILABLE;
+
+	// Reset any available pipe (except control)
+	for (i=0; i<USB_MAXINTERFACES; i++) {
+		winusb_handle = handle_priv->interface_handle[i].api_handle;
+		for (wfd = handle_to_winfd(winusb_handle); wfd.fd > 0;)
+		{
+			// Cancel any pollable I/O
+			usbi_remove_pollfd(ctx, wfd.fd);
+			usbi_free_fd(wfd.fd);
+			wfd = handle_to_winfd(winusb_handle);
+		}
+
+		if ( (winusb_handle != 0) && (winusb_handle != INVALID_HANDLE_VALUE)) {
+			for (j=0; j<priv->usb_interface[i].nb_endpoints; j++) {
+				usbi_dbg("resetting ep %02X", priv->usb_interface[i].endpoint[j]);
+				if (!WinUsb_AbortPipe(winusb_handle, priv->usb_interface[i].endpoint[j])) {
+					usbi_err(ctx, "WinUsb_AbortPipe (pipe address %02X) failed: %s",
+						priv->usb_interface[i].endpoint[j], windows_error_str(0));
+				}
+				// FlushPipe seems to fail on OUT pipes
+				if ( (priv->usb_interface[i].endpoint[j] & LIBUSB_ENDPOINT_IN)
+				  && (!WinUsb_FlushPipe(winusb_handle, priv->usb_interface[i].endpoint[j])) ) {
+					usbi_err(ctx, "WinUsb_FlushPipe (pipe address %02X) failed: %s",
+						priv->usb_interface[i].endpoint[j], windows_error_str(0));
+				}
+				if (!WinUsb_ResetPipe(winusb_handle, priv->usb_interface[i].endpoint[j])) {
+					usbi_err(ctx, "WinUsb_ResetPipe (pipe address %02X) failed: %s",
+						priv->usb_interface[i].endpoint[j], windows_error_str(0));
+				}
+			}
+		}
+	}
+
+	return LIBUSB_SUCCESS;
+}
+
+static int winusb_copy_transfer_data(struct usbi_transfer *itransfer, uint32_t io_size)
+{
+	itransfer->transferred += io_size;
+	return LIBUSB_TRANSFER_COMPLETED;
+}
+
+/*
+ * Internal HID Support functions (from libusb-win32)
+ * Note that functions that complete data transfer synchronously must return
+ * LIBUSB_COMPLETED instead of LIBUSB_SUCCESS
+ */
+static int _hid_get_hid_descriptor(struct hid_device_priv* dev, void *data, size_t *size);
+static int _hid_get_report_descriptor(struct hid_device_priv* dev, void *data, size_t *size);
+
+static int _hid_wcslen(WCHAR *str)
+{
+	int i = 0;
+	while (str[i] && (str[i] != 0x409)) {
+		i++;
+	}
+	return i;
+}
+
+static int _hid_get_device_descriptor(struct hid_device_priv* dev, void *data, size_t *size)
+{
+	struct libusb_device_descriptor d;
+
+	d.bLength = LIBUSB_DT_DEVICE_SIZE;
+	d.bDescriptorType = LIBUSB_DT_DEVICE;
+	d.bcdUSB = 0x0200; /* 2.00 */
+	d.bDeviceClass = 0;
+	d.bDeviceSubClass = 0;
+	d.bDeviceProtocol = 0;
+	d.bMaxPacketSize0 = 64; /* fix this! */
+	d.idVendor = (uint16_t)dev->vid;
+	d.idProduct = (uint16_t)dev->pid;
+	d.bcdDevice = 0x0100;
+	d.iManufacturer = dev->string_index[0];
+	d.iProduct = dev->string_index[1];
+	d.iSerialNumber = dev->string_index[2];
+	d.bNumConfigurations = 1;
+
+	if (*size > LIBUSB_DT_DEVICE_SIZE)
+		*size = LIBUSB_DT_DEVICE_SIZE;
+	memcpy(data, &d, *size);
+	return LIBUSB_COMPLETED;
+}
+
+static int _hid_get_config_descriptor(struct hid_device_priv* dev, void *data, size_t *size)
+{
+	char num_endpoints = 0;
+	size_t config_total_len = 0;
+	char tmp[HID_MAX_CONFIG_DESC_SIZE];
+	struct libusb_config_descriptor *cd;
+	struct libusb_interface_descriptor *id;
+	struct libusb_hid_descriptor *hd;
+	struct libusb_endpoint_descriptor *ed;
+	size_t tmp_size;
+
+	if (dev->input_report_size)
+		num_endpoints++;
+	if (dev->output_report_size)
+		num_endpoints++;
+
+	config_total_len = LIBUSB_DT_CONFIG_SIZE + LIBUSB_DT_INTERFACE_SIZE
+		+ LIBUSB_DT_HID_SIZE + num_endpoints * LIBUSB_DT_ENDPOINT_SIZE;
+
+
+	cd = (struct libusb_config_descriptor *)tmp;
+	id = (struct libusb_interface_descriptor *)(tmp + LIBUSB_DT_CONFIG_SIZE);
+	hd = (struct libusb_hid_descriptor *)(tmp + LIBUSB_DT_CONFIG_SIZE
+		+ LIBUSB_DT_INTERFACE_SIZE);
+	ed = (struct libusb_endpoint_descriptor *)(tmp + LIBUSB_DT_CONFIG_SIZE
+		+ LIBUSB_DT_INTERFACE_SIZE
+		+ LIBUSB_DT_HID_SIZE);
+
+	cd->bLength = LIBUSB_DT_CONFIG_SIZE;
+	cd->bDescriptorType = LIBUSB_DT_CONFIG;
+	cd->wTotalLength = (uint16_t) config_total_len;
+	cd->bNumInterfaces = 1;
+	cd->bConfigurationValue = 1;
+	cd->iConfiguration = 0;
+	cd->bmAttributes = 1 << 7; /* bus powered */
+	cd->MaxPower = 50;
+
+	id->bLength = LIBUSB_DT_INTERFACE_SIZE;
+	id->bDescriptorType = LIBUSB_DT_INTERFACE;
+	id->bInterfaceNumber = 0;
+	id->bAlternateSetting = 0;
+	id->bNumEndpoints = num_endpoints;
+	id->bInterfaceClass = 3;
+	id->bInterfaceSubClass = 0;
+	id->bInterfaceProtocol = 0;
+	id->iInterface = 0;
+
+	tmp_size = LIBUSB_DT_HID_SIZE;
+	_hid_get_hid_descriptor(dev, hd, &tmp_size);
+
+	if (dev->input_report_size) {
+		ed->bLength = LIBUSB_DT_ENDPOINT_SIZE;
+		ed->bDescriptorType = LIBUSB_DT_ENDPOINT;
+		ed->bEndpointAddress = HID_IN_EP;
+		ed->bmAttributes = 3;
+		ed->wMaxPacketSize = dev->input_report_size - 1;
+		ed->bInterval = 10;
+
+		ed++;
+	}
+
+	if (dev->output_report_size) {
+		ed->bLength = LIBUSB_DT_ENDPOINT_SIZE;
+		ed->bDescriptorType = LIBUSB_DT_ENDPOINT;
+		ed->bEndpointAddress = HID_OUT_EP;
+		ed->bmAttributes = 3;
+		ed->wMaxPacketSize = dev->output_report_size - 1;
+		ed->bInterval = 10;
+	}
+
+	if (*size > config_total_len)
+		*size = config_total_len;
+	memcpy(data, tmp, *size);
+	return LIBUSB_COMPLETED;
+}
+
+static int _hid_get_string_descriptor(struct hid_device_priv* dev, int index,
+									  void *data, size_t *size)
+{
+	void *tmp = NULL;
+	size_t tmp_size = 0;
+	int i;
+
+	/* language ID, EN-US */
+	char string_langid[] = {
+		0x09,
+		0x04
+	};
+
+	if ((*size < 2) || (*size > 255)) {
+		return LIBUSB_ERROR_OVERFLOW;
+	}
+
+	if (index == 0) {
+		tmp = string_langid;
+		tmp_size = sizeof(string_langid)+2;
+	} else {
+		for (i=0; i<3; i++) {
+			if (index == (dev->string_index[i])) {
+				tmp = dev->string[i];
+				tmp_size = (_hid_wcslen(dev->string[i])+1) * sizeof(WCHAR);
+				break;
+			}
+		}
+		if (i == 3) {	// not found
+			return LIBUSB_ERROR_INVALID_PARAM;
+		}
+	}
+
+	if(!tmp_size) {
+		return LIBUSB_ERROR_INVALID_PARAM;
+	}
+
+	if (tmp_size < *size) {
+		*size = tmp_size;
+	}
+	// 2 byte header
+	((uint8_t*)data)[0] = (uint8_t)*size;
+	((uint8_t*)data)[1] = LIBUSB_DT_STRING;
+	memcpy((uint8_t*)data+2, tmp, *size-2);
+	return LIBUSB_COMPLETED;
+}
+
+static int _hid_get_hid_descriptor(struct hid_device_priv* dev, void *data, size_t *size)
+{
+	struct libusb_hid_descriptor d;
+	uint8_t tmp[MAX_HID_DESCRIPTOR_SIZE];
+	size_t report_len = MAX_HID_DESCRIPTOR_SIZE;
+
+	_hid_get_report_descriptor(dev, tmp, &report_len);
+
+	d.bLength = LIBUSB_DT_HID_SIZE;
+	d.bDescriptorType = LIBUSB_DT_HID;
+	d.bcdHID = 0x0110; /* 1.10 */
+	d.bCountryCode = 0;
+	d.bNumDescriptors = 1;
+	d.bClassDescriptorType = LIBUSB_DT_REPORT;
+	d.wClassDescriptorLength = (uint16_t)report_len;
+
+	if (*size > LIBUSB_DT_HID_SIZE)
+		*size = LIBUSB_DT_HID_SIZE;
+	memcpy(data, &d, *size);
+	return LIBUSB_COMPLETED;
+}
+
+static int _hid_get_report_descriptor(struct hid_device_priv* dev, void *data, size_t *size)
+{
+	uint8_t d[MAX_HID_DESCRIPTOR_SIZE];
+	size_t i = 0;
+
+	/* usage page (0xFFA0 == vendor defined) */
+	d[i++] = 0x06; d[i++] = 0xA0; d[i++] = 0xFF;
+	/* usage (vendor defined) */
+	d[i++] = 0x09; d[i++] = 0x01;
+	/* start collection (application) */
+	d[i++] = 0xA1; d[i++] = 0x01;
+	/* input report */
+	if (dev->input_report_size) {
+		/* usage (vendor defined) */
+		d[i++] = 0x09; d[i++] = 0x01;
+		/* logical minimum (0) */
+		d[i++] = 0x15; d[i++] = 0x00;
+		/* logical maximum (255) */
+		d[i++] = 0x25; d[i++] = 0xFF;
+		/* report size (8 bits) */
+		d[i++] = 0x75; d[i++] = 0x08;
+		/* report count */
+		d[i++] = 0x95; d[i++] = (uint8_t)dev->input_report_size - 1;
+		/* input (data, variable, absolute) */
+		d[i++] = 0x81; d[i++] = 0x00;
+	}
+	/* output report */
+	if (dev->output_report_size) {
+		/* usage (vendor defined) */
+		d[i++] = 0x09; d[i++] = 0x02;
+		/* logical minimum (0) */
+		d[i++] = 0x15; d[i++] = 0x00;
+		/* logical maximum (255) */
+		d[i++] = 0x25; d[i++] = 0xFF;
+		/* report size (8 bits) */
+		d[i++] = 0x75; d[i++] = 0x08;
+		/* report count */
+		d[i++] = 0x95; d[i++] = (uint8_t)dev->output_report_size - 1;
+		/* output (data, variable, absolute) */
+		d[i++] = 0x91; d[i++] = 0x00;
+	}
+	/* feature report */
+	if (dev->feature_report_size) {
+		/* usage (vendor defined) */
+		d[i++] = 0x09; d[i++] = 0x03;
+		/* logical minimum (0) */
+		d[i++] = 0x15; d[i++] = 0x00;
+		/* logical maximum (255) */
+		d[i++] = 0x25; d[i++] = 0xFF;
+		/* report size (8 bits) */
+		d[i++] = 0x75; d[i++] = 0x08;
+		/* report count */
+		d[i++] = 0x95; d[i++] = (uint8_t)dev->feature_report_size - 1;
+		/* feature (data, variable, absolute) */
+		d[i++] = 0xb2; d[i++] = 0x02; d[i++] = 0x01;
+	}
+
+	/* end collection */
+	d[i++] = 0xC0;
+
+	if (*size > i)
+		*size = i;
+	memcpy(data, d, *size);
+	return LIBUSB_COMPLETED;
+}
+
+static int _hid_get_descriptor(struct hid_device_priv* dev, HANDLE hid_handle, int recipient,
+							   int type, int index, void *data, size_t *size)
+{
+	switch(type) {
+	case LIBUSB_DT_DEVICE:
+		usbi_dbg("LIBUSB_DT_DEVICE");
+		return _hid_get_device_descriptor(dev, data, size);
+	case LIBUSB_DT_CONFIG:
+		usbi_dbg("LIBUSB_DT_CONFIG");
+		if (!index)
+			return _hid_get_config_descriptor(dev, data, size);
+		return LIBUSB_ERROR_INVALID_PARAM;
+	case LIBUSB_DT_STRING:
+		usbi_dbg("LIBUSB_DT_STRING");
+		return _hid_get_string_descriptor(dev, index, data, size);
+	case LIBUSB_DT_HID:
+		usbi_dbg("LIBUSB_DT_HID");
+		if (!index)
+			return _hid_get_hid_descriptor(dev, data, size);
+		return LIBUSB_ERROR_INVALID_PARAM;
+	case LIBUSB_DT_REPORT:
+		usbi_dbg("LIBUSB_DT_REPORT");
+		if (!index)
+			return _hid_get_report_descriptor(dev, data, size);
+		return LIBUSB_ERROR_INVALID_PARAM;
+	case LIBUSB_DT_PHYSICAL:
+		usbi_dbg("LIBUSB_DT_PHYSICAL");
+		if (HidD_GetPhysicalDescriptor(hid_handle, data, (ULONG)*size))
+			return LIBUSB_COMPLETED;
+		return LIBUSB_ERROR_OTHER;
+	}
+	usbi_dbg("unsupported");
+	return LIBUSB_ERROR_INVALID_PARAM;
+}
+
+static int _hid_get_report(struct hid_device_priv* dev, HANDLE hid_handle, int id, void *data,
+						   struct windows_transfer_priv *tp, size_t *size, OVERLAPPED* overlapped,
+						   int report_type)
+{
+	uint8_t *buf;
+	DWORD ioctl_code, read_size, expected_size = (DWORD)*size;
+	int r = LIBUSB_SUCCESS;
+
+	if (tp->hid_buffer != NULL) {
+		usbi_dbg("program assertion failed: hid_buffer is not NULL");
+	}
+
+	if ((*size == 0) || (*size > MAX_HID_REPORT_SIZE)) {
+		usbi_dbg("invalid size (%d)", *size);
+		return LIBUSB_ERROR_INVALID_PARAM;
+	}
+
+	switch (report_type) {
+		case HID_REPORT_TYPE_INPUT:
+			ioctl_code = IOCTL_HID_GET_INPUT_REPORT;
+			break;
+		case HID_REPORT_TYPE_FEATURE:
+			ioctl_code = IOCTL_HID_GET_FEATURE;
+			break;
+		default:
+			usbi_dbg("unknown HID report type %d", report_type);
+			return LIBUSB_ERROR_INVALID_PARAM;
+	}
+
+	// When report IDs are not in use, add an extra byte for the report ID
+	if (id==0) {
+		expected_size++;
+	}
+
+	// Add a trailing byte to detect overflows
+	buf = (uint8_t*)calloc(expected_size+1, 1);
+	if (buf == NULL) {
+		return LIBUSB_ERROR_NO_MEM;
+	}
+	buf[0] = (uint8_t)id;	// Must be set always
+	usbi_dbg("report ID: 0x%02X", buf[0]);
+
+	tp->hid_expected_size = expected_size;
+
+	if (!DeviceIoControl(hid_handle, ioctl_code, buf, expected_size+1,
+		buf, expected_size+1, &read_size, overlapped)) {
+		if (GetLastError() != ERROR_IO_PENDING) {
+			usbi_dbg("Failed to Read HID Report: %s", windows_error_str(0));
+			safe_free(buf);
+			return LIBUSB_ERROR_IO;
+		}
+		// Asynchronous wait
+		tp->hid_buffer = buf;
+		tp->hid_dest = data; // copy dest, as not necessarily the start of the transfer buffer
+		return LIBUSB_SUCCESS;
+	}
+
+	// Transfer completed synchronously => copy and discard extra buffer
+	if (read_size == 0) {
+		usbi_dbg("program assertion failed - read completed synchronously, but no data was read");
+		*size = 0;
+	} else {
+		if (buf[0] != id) {
+			usbi_warn(NULL, "mismatched report ID (data is %02X, parameter is %02X)", buf[0], id);
+		}
+		if ((size_t)read_size > expected_size) {
+			r = LIBUSB_ERROR_OVERFLOW;
+			usbi_dbg("OVERFLOW!");
+		} else {
+			r = LIBUSB_COMPLETED;
+		}
+
+		if (id == 0) {
+			// Discard report ID
+			*size = MIN((size_t)read_size-1, *size);
+			memcpy(data, buf+1, *size);
+		} else {
+			*size = MIN((size_t)read_size, *size);
+			memcpy(data, buf, *size);
+		}
+	}
+	safe_free(buf);
+	return r;
+}
+
+static int _hid_set_report(struct hid_device_priv* dev, HANDLE hid_handle, int id, void *data,
+						   struct windows_transfer_priv *tp, size_t *size, OVERLAPPED* overlapped,
+						   int report_type)
+{
+	uint8_t *buf = NULL;
+	DWORD ioctl_code, write_size= (DWORD)*size;
+
+	if (tp->hid_buffer != NULL) {
+		usbi_dbg("program assertion failed: hid_buffer is not NULL");
+	}
+
+	if ((*size == 0) || (*size > MAX_HID_REPORT_SIZE)) {
+		usbi_dbg("invalid size (%d)", *size);
+		return LIBUSB_ERROR_INVALID_PARAM;
+	}
+
+	switch (report_type) {
+		case HID_REPORT_TYPE_OUTPUT:
+			ioctl_code = IOCTL_HID_SET_OUTPUT_REPORT;
+			break;
+		case HID_REPORT_TYPE_FEATURE:
+			ioctl_code = IOCTL_HID_SET_FEATURE;
+			break;
+		default:
+			usbi_dbg("unknown HID report type %d", report_type);
+			return LIBUSB_ERROR_INVALID_PARAM;
+	}
+
+	usbi_dbg("report ID: 0x%02X", id);
+	// When report IDs are not used (i.e. when id == 0), we must add
+	// a null report ID. Otherwise, we just use original data buffer
+	if (id == 0) {
+		write_size++;
+	}
+	buf = malloc(write_size);
+	if (buf == NULL) {
+		return LIBUSB_ERROR_NO_MEM;
+	}
+	if (id == 0) {
+		buf[0] = 0;
+		memcpy(buf + 1, data, *size);
+	} else {
+		// This seems like a waste, but if we don't duplicate the
+		// data, we'll get issues when freeing hid_buffer
+		memcpy(buf, data, *size);
+		if (buf[0] != id) {
+			usbi_warn(NULL, "mismatched report ID (data is %02X, parameter is %02X)", buf[0], id);
+		}
+	}
+
+	if (!DeviceIoControl(hid_handle, ioctl_code, buf, write_size,
+		buf, write_size, &write_size, overlapped)) {
+		if (GetLastError() != ERROR_IO_PENDING) {
+			usbi_dbg("Failed to Write HID Output Report: %s", windows_error_str(0));
+			safe_free(buf);
+			return LIBUSB_ERROR_IO;
+		}
+		tp->hid_buffer = buf;
+		tp->hid_dest = NULL;
+		return LIBUSB_SUCCESS;
+	}
+
+	// Transfer completed synchronously
+	if (write_size == 0) {
+		usbi_dbg("program assertion failed - write completed synchronously, but no data was written");
+		*size = 0;
+	} else {
+		*size = write_size - ((id == 0)?1:0);
+	}
+	safe_free(buf);
+	return LIBUSB_COMPLETED;
+}
+
+static int _hid_class_request(struct hid_device_priv* dev, HANDLE hid_handle, int request_type,
+							  int request, int value, int index, void *data, struct windows_transfer_priv *tp,
+							  size_t *size, OVERLAPPED* overlapped)
+{
+	int report_type = (value >> 8) & 0xFF;
+	int report_id = value & 0xFF;
+
+	if ( (LIBUSB_REQ_RECIPIENT(request_type) != LIBUSB_RECIPIENT_INTERFACE)
+	  && (LIBUSB_REQ_RECIPIENT(request_type) != LIBUSB_RECIPIENT_DEVICE) )
+		return LIBUSB_ERROR_INVALID_PARAM;
+
+	if (LIBUSB_REQ_OUT(request_type) && request == HID_REQ_SET_REPORT)
+		return _hid_set_report(dev, hid_handle, report_id, data, tp, size, overlapped, report_type);
+
+	if (LIBUSB_REQ_IN(request_type) && request == HID_REQ_GET_REPORT)
+		return _hid_get_report(dev, hid_handle, report_id, data, tp, size, overlapped, report_type);
+
+	return LIBUSB_ERROR_INVALID_PARAM;
+}
+
+
+/*
+ * HID API functions
+ */
+static int hid_init(struct libusb_context *ctx)
+{
+	DLL_LOAD(hid.dll, HidD_GetAttributes, TRUE);
+	DLL_LOAD(hid.dll, HidD_GetHidGuid, TRUE);
+	DLL_LOAD(hid.dll, HidD_GetPreparsedData, TRUE);
+	DLL_LOAD(hid.dll, HidD_FreePreparsedData, TRUE);
+	DLL_LOAD(hid.dll, HidD_GetManufacturerString, TRUE);
+	DLL_LOAD(hid.dll, HidD_GetProductString, TRUE);
+	DLL_LOAD(hid.dll, HidD_GetSerialNumberString, TRUE);
+	DLL_LOAD(hid.dll, HidP_GetCaps, TRUE);
+	DLL_LOAD(hid.dll, HidD_SetNumInputBuffers, TRUE);
+	DLL_LOAD(hid.dll, HidD_SetFeature, TRUE);
+	DLL_LOAD(hid.dll, HidD_GetFeature, TRUE);
+	DLL_LOAD(hid.dll, HidD_GetPhysicalDescriptor, TRUE);
+	DLL_LOAD(hid.dll, HidD_GetInputReport, FALSE);
+	DLL_LOAD(hid.dll, HidD_SetOutputReport, FALSE);
+	DLL_LOAD(hid.dll, HidD_FlushQueue, TRUE);
+	DLL_LOAD(hid.dll, HidP_GetValueCaps, TRUE);
+
+	api_hid_available = true;
+	return LIBUSB_SUCCESS;
+}
+
+static int hid_exit(void)
+{
+	return LIBUSB_SUCCESS;
+}
+
+// NB: open and close must ensure that they only handle interface of
+// the right API type, as these functions can be called wholesale from
+// composite_open(), with interfaces belonging to different APIs
+static int hid_open(struct libusb_device_handle *dev_handle)
+{
+	struct libusb_context *ctx = DEVICE_CTX(dev_handle->dev);
+	struct windows_device_priv *priv = __device_priv(dev_handle->dev);
+	struct windows_device_handle_priv *handle_priv = __device_handle_priv(dev_handle);
+
+	HIDD_ATTRIBUTES hid_attributes;
+	PHIDP_PREPARSED_DATA preparsed_data = NULL;
+	HIDP_CAPS capabilities;
+	HIDP_VALUE_CAPS *value_caps;
+
+	HANDLE hid_handle = INVALID_HANDLE_VALUE;
+	int i, j;
+	// report IDs handling
+	ULONG size[3];
+	char* type[3] = {"input", "output", "feature"};
+	int nb_ids[2];	// zero and nonzero report IDs
+
+	CHECK_HID_AVAILABLE;
+	if (priv->hid == NULL) {
+		usbi_err(ctx, "program assertion failed - private HID structure is unitialized");
+		return LIBUSB_ERROR_NOT_FOUND;
+	}
+
+	for (i = 0; i < USB_MAXINTERFACES; i++) {
+		if ( (priv->usb_interface[i].path != NULL)
+		  && (priv->usb_interface[i].apib->id == USB_API_HID) ) {
+			hid_handle = CreateFileA(priv->usb_interface[i].path, GENERIC_WRITE | GENERIC_READ, FILE_SHARE_WRITE | FILE_SHARE_READ,
+				NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED, NULL);
+			/*
+			 * http://www.lvr.com/hidfaq.htm: Why do I receive "Access denied" when attempting to access my HID?
+			 * "Windows 2000 and later have exclusive read/write access to HIDs that are configured as a system
+			 * keyboards or mice. An application can obtain a handle to a system keyboard or mouse by not
+			 * requesting READ or WRITE access with CreateFile. Applications can then use HidD_SetFeature and
+			 * HidD_GetFeature (if the device supports Feature reports)."
+			 */
+			if (hid_handle == INVALID_HANDLE_VALUE) {
+				usbi_warn(ctx, "could not open HID device in R/W mode (keyboard or mouse?) - trying without");
+				hid_handle = CreateFileA(priv->usb_interface[i].path, 0, FILE_SHARE_WRITE | FILE_SHARE_READ,
+					NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED, NULL);
+				if (hid_handle == INVALID_HANDLE_VALUE) {
+					usbi_err(ctx, "could not open device %s (interface %d): %s", priv->path, i, windows_error_str(0));
+					switch(GetLastError()) {
+					case ERROR_FILE_NOT_FOUND:	// The device was disconnected
+						return LIBUSB_ERROR_NO_DEVICE;
+					case ERROR_ACCESS_DENIED:
+						return LIBUSB_ERROR_ACCESS;
+					default:
+						return LIBUSB_ERROR_IO;
+					}
+				}
+				priv->usb_interface[i].restricted_functionality = true;
+			}
+			handle_priv->interface_handle[i].api_handle = hid_handle;
+		}
+	}
+
+	hid_attributes.Size = sizeof(hid_attributes);
+	do {
+		if (!HidD_GetAttributes(hid_handle, &hid_attributes)) {
+			usbi_err(ctx, "could not gain access to HID top collection (HidD_GetAttributes)");
+			break;
+		}
+
+		priv->hid->vid = hid_attributes.VendorID;
+		priv->hid->pid = hid_attributes.ProductID;
+
+		// Set the maximum available input buffer size
+		for (i=32; HidD_SetNumInputBuffers(hid_handle, i); i*=2);
+		usbi_dbg("set maximum input buffer size to %d", i/2);
+
+		// Get the maximum input and output report size
+		if (!HidD_GetPreparsedData(hid_handle, &preparsed_data) || !preparsed_data) {
+			usbi_err(ctx, "could not read HID preparsed data (HidD_GetPreparsedData)");
+			break;
+		}
+		if (HidP_GetCaps(preparsed_data, &capabilities) != HIDP_STATUS_SUCCESS) {
+			usbi_err(ctx, "could not parse HID capabilities (HidP_GetCaps)");
+			break;
+		}
+
+		// Find out if interrupt will need report IDs
+		size[0] = capabilities.NumberInputValueCaps;
+		size[1] = capabilities.NumberOutputValueCaps;
+		size[2] = capabilities.NumberFeatureValueCaps;
+		for (j=0; j<3; j++) {
+			usbi_dbg("%d HID %s report value(s) found", size[j], type[j]);
+			priv->hid->uses_report_ids[j] = false;
+			if (size[j] > 0) {
+				value_caps = malloc(size[j] * sizeof(HIDP_VALUE_CAPS));
+				if ( (value_caps != NULL)
+				  && (HidP_GetValueCaps(j, value_caps, &size[j], preparsed_data) == HIDP_STATUS_SUCCESS)
+				  && (size[j] >= 1) ) {
+					nb_ids[0] = 0;
+					nb_ids[1] = 0;
+					for (i=0; i<(int)size[j]; i++) {
+						usbi_dbg("  Report ID: 0x%02X", value_caps[i].ReportID);
+						if (value_caps[i].ReportID != 0) {
+							nb_ids[1]++;
+						} else {
+							nb_ids[0]++;
+						}
+					}
+					if (nb_ids[1] != 0) {
+						if (nb_ids[0] != 0) {
+							usbi_warn(ctx, "program assertion failed: zero and nonzero report IDs used for %s",
+								type[j]);
+						}
+						priv->hid->uses_report_ids[j] = true;
+					}
+				} else {
+					usbi_warn(ctx, "  could not process %s report IDs", type[j]);
+				}
+				safe_free(value_caps);
+			}
+		}
+
+		// Set the report sizes
+		priv->hid->input_report_size = capabilities.InputReportByteLength;
+		priv->hid->output_report_size = capabilities.OutputReportByteLength;
+		priv->hid->feature_report_size = capabilities.FeatureReportByteLength;
+
+		// Fetch string descriptors
+		priv->hid->string_index[0] = priv->dev_descriptor.iManufacturer;
+		if (priv->hid->string_index[0] != 0) {
+			HidD_GetManufacturerString(hid_handle, priv->hid->string[0],
+				sizeof(priv->hid->string[0]));
+		} else {
+			priv->hid->string[0][0] = 0;
+		}
+		priv->hid->string_index[1] = priv->dev_descriptor.iProduct;
+		if (priv->hid->string_index[1] != 0) {
+			HidD_GetProductString(hid_handle, priv->hid->string[1],
+				sizeof(priv->hid->string[1]));
+		} else {
+			priv->hid->string[1][0] = 0;
+		}
+		priv->hid->string_index[2] = priv->dev_descriptor.iSerialNumber;
+		if (priv->hid->string_index[2] != 0) {
+			HidD_GetSerialNumberString(hid_handle, priv->hid->string[2],
+				sizeof(priv->hid->string[2]));
+		} else {
+			priv->hid->string[2][0] = 0;
+		}
+	} while(0);
+
+	if (preparsed_data) {
+		HidD_FreePreparsedData(preparsed_data);
+	}
+
+	return LIBUSB_SUCCESS;
+}
+
+static void hid_close(struct libusb_device_handle *dev_handle)
+{
+	struct windows_device_priv *priv = __device_priv(dev_handle->dev);
+	struct windows_device_handle_priv *handle_priv = __device_handle_priv(dev_handle);
+	HANDLE file_handle;
+	int i;
+
+	if (!api_hid_available)
+		return;
+
+	for (i = 0; i < USB_MAXINTERFACES; i++) {
+		if (priv->usb_interface[i].apib->id == USB_API_HID) {
+			file_handle = handle_priv->interface_handle[i].api_handle;
+			if ( (file_handle != 0) && (file_handle != INVALID_HANDLE_VALUE)) {
+				CloseHandle(file_handle);
+			}
+		}
+	}
+}
+
+static int hid_claim_interface(struct libusb_device_handle *dev_handle, int iface)
+{
+	struct windows_device_handle_priv *handle_priv = __device_handle_priv(dev_handle);
+	struct windows_device_priv *priv = __device_priv(dev_handle->dev);
+
+	CHECK_HID_AVAILABLE;
+
+	// NB: Disconnection detection is not possible in this function
+	if (priv->usb_interface[iface].path == NULL) {
+		return LIBUSB_ERROR_NOT_FOUND;	// invalid iface
+	}
+
+	// We use dev_handle as a flag for interface claimed
+	if (handle_priv->interface_handle[iface].dev_handle == INTERFACE_CLAIMED) {
+		return LIBUSB_ERROR_BUSY;	// already claimed
+	}
+
+	handle_priv->interface_handle[iface].dev_handle = INTERFACE_CLAIMED;
+
+	usbi_dbg("claimed interface %d", iface);
+	handle_priv->active_interface = iface;
+
+	return LIBUSB_SUCCESS;
+}
+
+static int hid_release_interface(struct libusb_device_handle *dev_handle, int iface)
+{
+	struct windows_device_handle_priv *handle_priv = __device_handle_priv(dev_handle);
+	struct windows_device_priv *priv = __device_priv(dev_handle->dev);
+
+	CHECK_HID_AVAILABLE;
+
+	if (priv->usb_interface[iface].path == NULL) {
+		return LIBUSB_ERROR_NOT_FOUND;	// invalid iface
+	}
+
+	if (handle_priv->interface_handle[iface].dev_handle != INTERFACE_CLAIMED) {
+		return LIBUSB_ERROR_NOT_FOUND;	// invalid iface
+	}
+
+	handle_priv->interface_handle[iface].dev_handle = INVALID_HANDLE_VALUE;
+
+	return LIBUSB_SUCCESS;
+}
+
+static int hid_set_interface_altsetting(struct libusb_device_handle *dev_handle, int iface, int altsetting)
+{
+	struct libusb_context *ctx = DEVICE_CTX(dev_handle->dev);
+
+	CHECK_HID_AVAILABLE;
+
+	if (altsetting > 255) {
+		return LIBUSB_ERROR_INVALID_PARAM;
+	}
+
+	if (altsetting != 0) {
+		usbi_err(ctx, "set interface altsetting not supported for altsetting >0");
+		return LIBUSB_ERROR_NOT_SUPPORTED;
+	}
+
+	return LIBUSB_SUCCESS;
+}
+
+static int hid_submit_control_transfer(struct usbi_transfer *itransfer)
+{
+	struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct windows_transfer_priv *transfer_priv = usbi_transfer_get_os_priv(itransfer);
+	struct windows_device_handle_priv *handle_priv = __device_handle_priv(transfer->dev_handle);
+	struct windows_device_priv *priv = __device_priv(transfer->dev_handle->dev);
+	struct libusb_context *ctx = DEVICE_CTX(transfer->dev_handle->dev);
+	WINUSB_SETUP_PACKET *setup = (WINUSB_SETUP_PACKET *) transfer->buffer;
+	HANDLE hid_handle;
+	struct winfd wfd;
+	int current_interface, config;
+	size_t size;
+	int r = LIBUSB_ERROR_INVALID_PARAM;
+
+	CHECK_HID_AVAILABLE;
+
+	transfer_priv->pollable_fd = INVALID_WINFD;
+	safe_free(transfer_priv->hid_buffer);
+	transfer_priv->hid_dest = NULL;
+	size = transfer->length - LIBUSB_CONTROL_SETUP_SIZE;
+
+	if (size > MAX_CTRL_BUFFER_LENGTH) {
+		return LIBUSB_ERROR_INVALID_PARAM;
+	}
+
+	current_interface = get_valid_interface(transfer->dev_handle, USB_API_HID);
+	if (current_interface < 0) {
+#if defined(AUTO_CLAIM)
+		if (auto_claim(transfer, &current_interface, USB_API_HID) != LIBUSB_SUCCESS) {
+			return LIBUSB_ERROR_NOT_FOUND;
+		}
+#else
+		usbi_warn(ctx, "no interface available for control transfer");
+		return LIBUSB_ERROR_NOT_FOUND;
+#endif
+	}
+
+	usbi_dbg("will use interface %d", current_interface);
+	hid_handle = handle_priv->interface_handle[current_interface].api_handle;
+	// Always use the handle returned from usbi_create_fd (wfd.handle)
+	wfd = usbi_create_fd(hid_handle, _O_RDONLY);
+	if (wfd.fd < 0) {
+		return LIBUSB_ERROR_NO_MEM;
+	}
+
+	switch(LIBUSB_REQ_TYPE(setup->request_type)) {
+	case LIBUSB_REQUEST_TYPE_STANDARD:
+		switch(setup->request) {
+		case LIBUSB_REQUEST_GET_DESCRIPTOR:
+			r = _hid_get_descriptor(priv->hid, wfd.handle, LIBUSB_REQ_RECIPIENT(setup->request_type),
+				(setup->value >> 8) & 0xFF, setup->value & 0xFF, transfer->buffer + LIBUSB_CONTROL_SETUP_SIZE, &size);
+			break;
+		case LIBUSB_REQUEST_GET_CONFIGURATION:
+			r = windows_get_configuration(transfer->dev_handle, &config);
+			if (r == LIBUSB_SUCCESS) {
+				size = 1;
+				((uint8_t*)transfer->buffer)[LIBUSB_CONTROL_SETUP_SIZE] = (uint8_t)config;
+				r = LIBUSB_COMPLETED;
+			}
+			break;
+		case LIBUSB_REQUEST_SET_CONFIGURATION:
+			if (setup->value == priv->active_config) {
+				r = LIBUSB_COMPLETED;
+			} else {
+				usbi_warn(ctx, "cannot set configuration other than the default one");
+				r = LIBUSB_ERROR_INVALID_PARAM;
+			}
+			break;
+		case LIBUSB_REQUEST_GET_INTERFACE:
+			size = 1;
+			((uint8_t*)transfer->buffer)[LIBUSB_CONTROL_SETUP_SIZE] = 0;
+			r = LIBUSB_COMPLETED;
+			break;
+		case LIBUSB_REQUEST_SET_INTERFACE:
+			r = hid_set_interface_altsetting(transfer->dev_handle, setup->index, setup->value);
+			if (r == LIBUSB_SUCCESS) {
+				r = LIBUSB_COMPLETED;
+			}
+			break;
+		default:
+			usbi_warn(ctx, "unsupported HID control request");
+			r = LIBUSB_ERROR_INVALID_PARAM;
+			break;
+		}
+		break;
+	case LIBUSB_REQUEST_TYPE_CLASS:
+		r =_hid_class_request(priv->hid, wfd.handle, setup->request_type, setup->request, setup->value,
+			setup->index, transfer->buffer + LIBUSB_CONTROL_SETUP_SIZE, transfer_priv,
+			&size, wfd.overlapped);
+		break;
+	default:
+		usbi_warn(ctx, "unsupported HID control request");
+		r = LIBUSB_ERROR_INVALID_PARAM;
+		break;
+	}
+
+	if (r == LIBUSB_COMPLETED) {
+		// Force request to be completed synchronously. Transferred size has been set by previous call
+		wfd.overlapped->Internal = STATUS_COMPLETED_SYNCHRONOUSLY;
+		// http://msdn.microsoft.com/en-us/library/ms684342%28VS.85%29.aspx
+		// set InternalHigh to the number of bytes transferred
+		wfd.overlapped->InternalHigh = (DWORD)size;
+		r = LIBUSB_SUCCESS;
+	}
+
+	if (r == LIBUSB_SUCCESS) {
+		// Use priv_transfer to store data needed for async polling
+		transfer_priv->pollable_fd = wfd;
+		transfer_priv->interface_number = (uint8_t)current_interface;
+	} else {
+		usbi_free_fd(wfd.fd);
+	}
+
+	return r;
+}
+
+static int hid_submit_bulk_transfer(struct usbi_transfer *itransfer) {
+	struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct windows_transfer_priv *transfer_priv = usbi_transfer_get_os_priv(itransfer);
+	struct libusb_context *ctx = DEVICE_CTX(transfer->dev_handle->dev);
+	struct windows_device_handle_priv *handle_priv = __device_handle_priv(transfer->dev_handle);
+	struct windows_device_priv *priv = __device_priv(transfer->dev_handle->dev);
+	struct winfd wfd;
+	HANDLE hid_handle;
+	bool direction_in, ret;
+	int current_interface, length;
+	DWORD size;
+	int r = LIBUSB_SUCCESS;
+
+	CHECK_HID_AVAILABLE;
+
+	transfer_priv->pollable_fd = INVALID_WINFD;
+	transfer_priv->hid_dest = NULL;
+	safe_free(transfer_priv->hid_buffer);
+
+	current_interface = interface_by_endpoint(priv, handle_priv, transfer->endpoint);
+	if (current_interface < 0) {
+		usbi_err(ctx, "unable to match endpoint to an open interface - cancelling transfer");
+		return LIBUSB_ERROR_NOT_FOUND;
+	}
+
+	usbi_dbg("matched endpoint %02X with interface %d", transfer->endpoint, current_interface);
+
+	hid_handle = handle_priv->interface_handle[current_interface].api_handle;
+	direction_in = transfer->endpoint & LIBUSB_ENDPOINT_IN;
+
+	wfd = usbi_create_fd(hid_handle, direction_in?_O_RDONLY:_O_WRONLY);
+	// Always use the handle returned from usbi_create_fd (wfd.handle)
+	if (wfd.fd < 0) {
+		return LIBUSB_ERROR_NO_MEM;
+	}
+
+	// If report IDs are not in use, an extra prefix byte must be added
+	if ( ((direction_in) && (!priv->hid->uses_report_ids[0]))
+	  || ((!direction_in) && (!priv->hid->uses_report_ids[1])) ) {
+		length = transfer->length+1;
+	} else {
+		length = transfer->length;
+	}
+	// Add a trailing byte to detect overflows on input
+	transfer_priv->hid_buffer = (uint8_t*)calloc(length+1, 1);
+	if (transfer_priv->hid_buffer == NULL) {
+		return LIBUSB_ERROR_NO_MEM;
+	}
+	transfer_priv->hid_expected_size = length;
+
+	if (direction_in) {
+		transfer_priv->hid_dest = transfer->buffer;
+		usbi_dbg("reading %d bytes (report ID: 0x%02X)", length, transfer_priv->hid_buffer[0]);
+		ret = ReadFile(wfd.handle, transfer_priv->hid_buffer, length+1, &size, wfd.overlapped);
+	} else {
+		if (!priv->hid->uses_report_ids[1]) {
+			memcpy(transfer_priv->hid_buffer+1, transfer->buffer, transfer->length);
+		} else {
+			// We could actually do without the calloc and memcpy in this case
+			memcpy(transfer_priv->hid_buffer, transfer->buffer, transfer->length);
+		}
+		usbi_dbg("writing %d bytes (report ID: 0x%02X)", length, transfer_priv->hid_buffer[0]);
+		ret = WriteFile(wfd.handle, transfer_priv->hid_buffer, length, &size, wfd.overlapped);
+	}
+	if (!ret) {
+		if (GetLastError() != ERROR_IO_PENDING) {
+			usbi_err(ctx, "HID transfer failed: %s", windows_error_str(0));
+			usbi_free_fd(wfd.fd);
+			safe_free(transfer_priv->hid_buffer);
+			return LIBUSB_ERROR_IO;
+		}
+	} else {
+		// Only write operations that completed synchronously need to free up
+		// hid_buffer. For reads, copy_transfer_data() handles that process.
+		if (!direction_in) {
+			safe_free(transfer_priv->hid_buffer);
+		}
+		if (size == 0) {
+			usbi_err(ctx, "program assertion failed - no data was transferred");
+			size = 1;
+		}
+		if (size > (size_t)length) {
+			usbi_err(ctx, "OVERFLOW!");
+			r = LIBUSB_ERROR_OVERFLOW;
+		}
+		wfd.overlapped->Internal = STATUS_COMPLETED_SYNCHRONOUSLY;
+		wfd.overlapped->InternalHigh = size;
+	}
+
+	transfer_priv->pollable_fd = wfd;
+	transfer_priv->interface_number = (uint8_t)current_interface;
+
+	return r;
+}
+
+static int hid_abort_transfers(struct usbi_transfer *itransfer)
+{
+	struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct windows_transfer_priv *transfer_priv = usbi_transfer_get_os_priv(itransfer);
+	struct windows_device_handle_priv *handle_priv = __device_handle_priv(transfer->dev_handle);
+	HANDLE hid_handle;
+	int current_interface;
+
+	CHECK_HID_AVAILABLE;
+
+	current_interface = transfer_priv->interface_number;
+	hid_handle = handle_priv->interface_handle[current_interface].api_handle;
+	CancelIo(hid_handle);
+
+	return LIBUSB_SUCCESS;
+}
+
+static int hid_reset_device(struct libusb_device_handle *dev_handle)
+{
+	struct windows_device_handle_priv *handle_priv = __device_handle_priv(dev_handle);
+	HANDLE hid_handle;
+	int current_interface;
+
+	CHECK_HID_AVAILABLE;
+
+	// Flushing the queues on all interfaces is the best we can achieve
+	for (current_interface = 0; current_interface < USB_MAXINTERFACES; current_interface++) {
+		hid_handle = handle_priv->interface_handle[current_interface].api_handle;
+		if ((hid_handle != 0) && (hid_handle != INVALID_HANDLE_VALUE)) {
+			HidD_FlushQueue(hid_handle);
+		}
+	}
+	return LIBUSB_SUCCESS;
+}
+
+static int hid_clear_halt(struct libusb_device_handle *dev_handle, unsigned char endpoint)
+{
+	struct libusb_context *ctx = DEVICE_CTX(dev_handle->dev);
+	struct windows_device_handle_priv *handle_priv = __device_handle_priv(dev_handle);
+	struct windows_device_priv *priv = __device_priv(dev_handle->dev);
+	HANDLE hid_handle;
+	int current_interface;
+
+	CHECK_HID_AVAILABLE;
+
+	current_interface = interface_by_endpoint(priv, handle_priv, endpoint);
+	if (current_interface < 0) {
+		usbi_err(ctx, "unable to match endpoint to an open interface - cannot clear");
+		return LIBUSB_ERROR_NOT_FOUND;
+	}
+
+	usbi_dbg("matched endpoint %02X with interface %d", endpoint, current_interface);
+	hid_handle = handle_priv->interface_handle[current_interface].api_handle;
+
+	// No endpoint selection with Microsoft's implementation, so we try to flush the
+	// whole interface. Should be OK for most case scenarios
+	if (!HidD_FlushQueue(hid_handle)) {
+		usbi_err(ctx, "Flushing of HID queue failed: %s", windows_error_str(0));
+		// Device was probably disconnected
+		return LIBUSB_ERROR_NO_DEVICE;
+	}
+
+	return LIBUSB_SUCCESS;
+}
+
+// This extra function is only needed for HID
+static int hid_copy_transfer_data(struct usbi_transfer *itransfer, uint32_t io_size) {
+	struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct libusb_context *ctx = DEVICE_CTX(transfer->dev_handle->dev);
+	struct windows_transfer_priv *transfer_priv = usbi_transfer_get_os_priv(itransfer);
+	int r = LIBUSB_TRANSFER_COMPLETED;
+	uint32_t corrected_size = io_size;
+
+	if (transfer_priv->hid_buffer != NULL) {
+		// If we have a valid hid_buffer, it means the transfer was async
+		if (transfer_priv->hid_dest != NULL) {	// Data readout
+			// First, check for overflow
+			if (corrected_size > transfer_priv->hid_expected_size) {
+				usbi_err(ctx, "OVERFLOW!");
+				corrected_size = (uint32_t)transfer_priv->hid_expected_size;
+				r = LIBUSB_TRANSFER_OVERFLOW;
+			}
+
+			if (transfer_priv->hid_buffer[0] == 0) {
+				// Discard the 1 byte report ID prefix
+				corrected_size--;
+				memcpy(transfer_priv->hid_dest, transfer_priv->hid_buffer+1, corrected_size);
+			} else {
+				memcpy(transfer_priv->hid_dest, transfer_priv->hid_buffer, corrected_size);
+			}
+			transfer_priv->hid_dest = NULL;
+		}
+		// For write, we just need to free the hid buffer
+		safe_free(transfer_priv->hid_buffer);
+	}
+	itransfer->transferred += corrected_size;
+	return r;
+}
+
+
+/*
+ * Composite API functions
+ */
+static int composite_init(struct libusb_context *ctx)
+{
+	return LIBUSB_SUCCESS;
+}
+
+static int composite_exit(void)
+{
+	return LIBUSB_SUCCESS;
+}
+
+static int composite_open(struct libusb_device_handle *dev_handle)
+{
+	struct windows_device_priv *priv = __device_priv(dev_handle->dev);
+	unsigned api;
+	int r;
+	uint8_t flag = 1<<USB_API_WINUSB;
+
+	for (api=USB_API_WINUSB; api<USB_API_MAX; api++) {
+		if (priv->composite_api_flags & flag) {
+			r = usb_api_backend[api].open(dev_handle);
+			if (r != LIBUSB_SUCCESS) {
+				return r;
+			}
+		}
+		flag <<= 1;
+	}
+	return LIBUSB_SUCCESS;
+}
+
+static void composite_close(struct libusb_device_handle *dev_handle)
+{
+	struct windows_device_priv *priv = __device_priv(dev_handle->dev);
+	unsigned api;
+	uint8_t flag = 1<<USB_API_WINUSB;
+
+	for (api=USB_API_WINUSB; api<USB_API_MAX; api++) {
+		if (priv->composite_api_flags & flag) {
+			usb_api_backend[api].close(dev_handle);
+		}
+		flag <<= 1;
+	}
+}
+
+static int composite_claim_interface(struct libusb_device_handle *dev_handle, int iface)
+{
+	struct windows_device_priv *priv = __device_priv(dev_handle->dev);
+	return priv->usb_interface[iface].apib->claim_interface(dev_handle, iface);
+}
+
+static int composite_set_interface_altsetting(struct libusb_device_handle *dev_handle, int iface, int altsetting)
+{
+	struct windows_device_priv *priv = __device_priv(dev_handle->dev);
+	return priv->usb_interface[iface].apib->set_interface_altsetting(dev_handle, iface, altsetting);
+}
+
+static int composite_release_interface(struct libusb_device_handle *dev_handle, int iface)
+{
+	struct windows_device_priv *priv = __device_priv(dev_handle->dev);
+	return priv->usb_interface[iface].apib->release_interface(dev_handle, iface);
+}
+
+static int composite_submit_control_transfer(struct usbi_transfer *itransfer)
+{
+	struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct libusb_context *ctx = DEVICE_CTX(transfer->dev_handle->dev);
+	struct windows_device_priv *priv = __device_priv(transfer->dev_handle->dev);
+	int i, pass;
+
+	// Interface shouldn't matter for control, but it does in practice, with Windows'
+	// restrictions with regards to accessing HID keyboards and mice. Try a 2 pass approach
+	for (pass = 0; pass < 2; pass++) {
+		for (i=0; i<USB_MAXINTERFACES; i++) {
+			if (priv->usb_interface[i].path != NULL) {
+				if ((pass == 0) && (priv->usb_interface[i].restricted_functionality)) {
+					usbi_dbg("trying to skip restricted interface #%d (HID keyboard or mouse?)", i);
+					continue;
+				}
+				usbi_dbg("using interface %d", i);
+				return priv->usb_interface[i].apib->submit_control_transfer(itransfer);
+			}
+		}
+	}
+
+	usbi_err(ctx, "no libusb supported interfaces to complete request");
+	return LIBUSB_ERROR_NOT_FOUND;
+}
+
+static int composite_submit_bulk_transfer(struct usbi_transfer *itransfer) {
+	struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct libusb_context *ctx = DEVICE_CTX(transfer->dev_handle->dev);
+	struct windows_device_handle_priv *handle_priv = __device_handle_priv(transfer->dev_handle);
+	struct windows_device_priv *priv = __device_priv(transfer->dev_handle->dev);
+	int current_interface;
+
+	current_interface = interface_by_endpoint(priv, handle_priv, transfer->endpoint);
+	if (current_interface < 0) {
+		usbi_err(ctx, "unable to match endpoint to an open interface - cancelling transfer");
+		return LIBUSB_ERROR_NOT_FOUND;
+	}
+
+	return priv->usb_interface[current_interface].apib->submit_bulk_transfer(itransfer);
+}
+
+static int composite_submit_iso_transfer(struct usbi_transfer *itransfer) {
+	struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct libusb_context *ctx = DEVICE_CTX(transfer->dev_handle->dev);
+	struct windows_device_handle_priv *handle_priv = __device_handle_priv(transfer->dev_handle);
+	struct windows_device_priv *priv = __device_priv(transfer->dev_handle->dev);
+	int current_interface;
+
+	current_interface = interface_by_endpoint(priv, handle_priv, transfer->endpoint);
+	if (current_interface < 0) {
+		usbi_err(ctx, "unable to match endpoint to an open interface - cancelling transfer");
+		return LIBUSB_ERROR_NOT_FOUND;
+	}
+
+	return priv->usb_interface[current_interface].apib->submit_iso_transfer(itransfer);
+}
+
+static int composite_clear_halt(struct libusb_device_handle *dev_handle, unsigned char endpoint)
+{
+	struct libusb_context *ctx = DEVICE_CTX(dev_handle->dev);
+	struct windows_device_handle_priv *handle_priv = __device_handle_priv(dev_handle);
+	struct windows_device_priv *priv = __device_priv(dev_handle->dev);
+	int current_interface;
+
+	current_interface = interface_by_endpoint(priv, handle_priv, endpoint);
+	if (current_interface < 0) {
+		usbi_err(ctx, "unable to match endpoint to an open interface - cannot clear");
+		return LIBUSB_ERROR_NOT_FOUND;
+	}
+
+	return priv->usb_interface[current_interface].apib->clear_halt(dev_handle, endpoint);
+}
+
+static int composite_abort_control(struct usbi_transfer *itransfer)
+{
+	struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct windows_transfer_priv *transfer_priv = usbi_transfer_get_os_priv(itransfer);
+	struct windows_device_priv *priv = __device_priv(transfer->dev_handle->dev);
+
+	return priv->usb_interface[transfer_priv->interface_number].apib->abort_control(itransfer);
+}
+
+static int composite_abort_transfers(struct usbi_transfer *itransfer)
+{
+	struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct windows_transfer_priv *transfer_priv = usbi_transfer_get_os_priv(itransfer);
+	struct windows_device_priv *priv = __device_priv(transfer->dev_handle->dev);
+
+	return priv->usb_interface[transfer_priv->interface_number].apib->abort_transfers(itransfer);
+}
+
+static int composite_reset_device(struct libusb_device_handle *dev_handle)
+{
+	struct windows_device_priv *priv = __device_priv(dev_handle->dev);
+	unsigned api;
+	int r;
+	uint8_t flag = 1<<USB_API_WINUSB;
+
+	for (api=USB_API_WINUSB; api<USB_API_MAX; api++) {
+		if (priv->composite_api_flags & flag) {
+			r = usb_api_backend[api].reset_device(dev_handle);
+			if (r != LIBUSB_SUCCESS) {
+				return r;
+			}
+		}
+		flag <<= 1;
+	}
+	return LIBUSB_SUCCESS;
+}
+
+static int composite_copy_transfer_data(struct usbi_transfer *itransfer, uint32_t io_size)
+{
+	struct libusb_transfer *transfer = __USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+	struct windows_transfer_priv *transfer_priv = usbi_transfer_get_os_priv(itransfer);
+	struct windows_device_priv *priv = __device_priv(transfer->dev_handle->dev);
+
+	return priv->usb_interface[transfer_priv->interface_number].apib->copy_transfer_data(itransfer, io_size);
+}
diff --git a/include/libusb-1.0/os/windows_usb.h b/include/libusb-1.0/os/windows_usb.h
new file mode 100644
index 0000000..dc90a64
--- /dev/null
+++ b/include/libusb-1.0/os/windows_usb.h
@@ -0,0 +1,784 @@
+/*
+ * Windows backend for libusb 1.0
+ * Copyright (C) 2009-2010 Pete Batard <pbatard@gmail.com>
+ * With contributions from Michael Plante, Orin Eman et al.
+ * Parts of this code adapted from libusb-win32-v1 by Stephan Meyer
+ * Major code testing contribution by Xiaofan Chen
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#pragma once
+
+#if defined(_MSC_VER)
+// disable /W4 MSVC warnings that are benign
+#pragma warning(disable:4127) // conditional expression is constant
+#pragma warning(disable:4100) // unreferenced formal parameter
+#pragma warning(disable:4214) // bit field types other than int
+#pragma warning(disable:4201) // nameless struct/union
+#endif
+
+// Windows API default is uppercase - ugh!
+#if !defined(bool)
+#define bool BOOL
+#endif
+#if !defined(true)
+#define true TRUE
+#endif
+#if !defined(false)
+#define false FALSE
+#endif
+
+#if !defined(libusb_bus_t)
+#define libusb_bus_t uint8_t
+#define LIBUSB_BUS_MAX UINT8_MAX
+#endif
+#if !defined(libusb_devaddr_t)
+#define libusb_devaddr_t uint8_t
+#define LIBUSB_DEVADDR_MAX UINT8_MAX
+#endif
+
+// Missing from MSVC6 setupapi.h
+#if !defined(SPDRP_ADDRESS)
+#define SPDRP_ADDRESS	28
+#endif
+#if !defined(SPDRP_INSTALL_STATE)
+#define SPDRP_INSTALL_STATE	34
+#endif
+
+#if defined(__CYGWIN__ )
+// cygwin produces a warning unless these prototypes are defined
+extern int _snprintf(char *buffer, size_t count, const char *format, ...);
+extern char *_strdup(const char *strSource);
+// _beginthreadex is MSVCRT => unavailable for cygwin. Fallback to using CreateThread
+#define _beginthreadex(a, b, c, d, e, f) CreateThread(a, b, (LPTHREAD_START_ROUTINE)c, d, e, f)
+#endif
+#define safe_free(p) do {if (p != NULL) {free((void*)p); p = NULL;}} while(0)
+#define safe_closehandle(h) do {if (h != INVALID_HANDLE_VALUE) {CloseHandle(h); h = INVALID_HANDLE_VALUE;}} while(0)
+#define safe_min(a, b) min((size_t)(a), (size_t)(b))
+#define safe_strcp(dst, dst_max, src, count) do {memcpy(dst, src, safe_min(count, dst_max)); \
+	((char*)dst)[safe_min(count, dst_max)-1] = 0;} while(0)
+#define safe_strcpy(dst, dst_max, src) safe_strcp(dst, dst_max, src, safe_strlen(src)+1)
+#define safe_strncat(dst, dst_max, src, count) strncat(dst, src, safe_min(count, dst_max - safe_strlen(dst) - 1))
+#define safe_strcat(dst, dst_max, src) safe_strncat(dst, dst_max, src, safe_strlen(src)+1)
+#define safe_strcmp(str1, str2) strcmp(((str1==NULL)?"<NULL>":str1), ((str2==NULL)?"<NULL>":str2))
+#define safe_strncmp(str1, str2, count) strncmp(((str1==NULL)?"<NULL>":str1), ((str2==NULL)?"<NULL>":str2), count)
+#define safe_strlen(str) ((str==NULL)?0:strlen(str))
+#define safe_sprintf _snprintf
+#define safe_unref_device(dev) do {if (dev != NULL) {libusb_unref_device(dev); dev = NULL;}} while(0)
+#define wchar_to_utf8_ms(wstr, str, strlen) WideCharToMultiByte(CP_UTF8, 0, wstr, -1, str, strlen, NULL, NULL)
+inline void upperize(char* str) {
+	size_t i;
+	if (str == NULL) return;
+	for (i=0; i<safe_strlen(str); i++)
+		str[i] = (char)toupper((int)str[i]);
+}
+
+#define MAX_CTRL_BUFFER_LENGTH      4096
+#define MAX_USB_DEVICES             256
+#define MAX_USB_STRING_LENGTH       128
+#define MAX_HID_REPORT_SIZE         1024
+#define MAX_HID_DESCRIPTOR_SIZE     256
+#define MAX_GUID_STRING_LENGTH      40
+#define MAX_PATH_LENGTH             128
+#define MAX_KEY_LENGTH              256
+#define MAX_TIMER_SEMAPHORES        128
+#define TIMER_REQUEST_RETRY_MS      100
+#define ERR_BUFFER_SIZE             256
+#define LIST_SEPARATOR              ';'
+
+// Handle code for HID interface that have been claimed ("dibs")
+#define INTERFACE_CLAIMED           ((HANDLE)(intptr_t)0xD1B5)
+// Additional return code for HID operations that completed synchronously
+#define LIBUSB_COMPLETED            (LIBUSB_SUCCESS + 1)
+
+// http://msdn.microsoft.com/en-us/library/bb663109.aspx
+// http://msdn.microsoft.com/en-us/library/bb663093.aspx
+#if !defined(GUID_DEVINTERFACE_USB_HOST_CONTROLLER)
+const GUID GUID_DEVINTERFACE_USB_HOST_CONTROLLER = { 0x3ABF6F2D, 0x71C4, 0x462A, {0x8A, 0x92, 0x1E, 0x68, 0x61, 0xE6, 0xAF, 0x27} };
+#endif
+#if !defined(GUID_DEVINTERFACE_USB_DEVICE)
+const GUID GUID_DEVINTERFACE_USB_DEVICE = { 0xA5DCBF10, 0x6530, 0x11D2, {0x90, 0x1F, 0x00, 0xC0, 0x4F, 0xB9, 0x51, 0xED} };
+#endif
+
+
+/*
+ * Multiple USB API backend support
+ */
+#define USB_API_UNSUPPORTED 0
+#define USB_API_COMPOSITE   1
+#define USB_API_WINUSB      2
+#define USB_API_HID         3
+#define USB_API_MAX         4
+
+const GUID CLASS_GUID_UNSUPPORTED   = { 0x00000000, 0x0000, 0x0000, {0x00, 0x00, 0x00, 0x00, 0x00, 0x0F, 0x57, 0xDA} };
+const GUID CLASS_GUID_HID           = { 0x745A17A0, 0x74D3, 0x11D0, {0xB6, 0xFE, 0x00, 0xA0, 0xC9, 0x0F, 0x57, 0xDA} };
+const GUID CLASS_GUID_LIBUSB_WINUSB = { 0x78A1C341, 0x4539, 0x11D3, {0xB8, 0x8D, 0x00, 0xC0, 0x4F, 0xAD, 0x51, 0x71} };
+const GUID CLASS_GUID_COMPOSITE     = { 0x36FC9E60, 0xC465, 0x11cF, {0x80, 0x56, 0x44, 0x45, 0x53, 0x54, 0x00, 0x00} };
+
+struct windows_usb_api_backend {
+	const uint8_t id;
+	const char* designation;
+	const GUID *class_guid;  // The Class GUID (for fallback in case the driver name cannot be read)
+	const char **driver_name_list; // Driver name, without .sys, e.g. "usbccgp"
+	const uint8_t nb_driver_names;
+	int (*init)(struct libusb_context *ctx);
+	int (*exit)(void);
+	int (*open)(struct libusb_device_handle *dev_handle);
+	void (*close)(struct libusb_device_handle *dev_handle);
+	int (*claim_interface)(struct libusb_device_handle *dev_handle, int iface);
+	int (*set_interface_altsetting)(struct libusb_device_handle *dev_handle, int iface, int altsetting);
+	int (*release_interface)(struct libusb_device_handle *dev_handle, int iface);
+	int (*clear_halt)(struct libusb_device_handle *dev_handle, unsigned char endpoint);
+	int (*reset_device)(struct libusb_device_handle *dev_handle);
+	int (*submit_bulk_transfer)(struct usbi_transfer *itransfer);
+	int (*submit_iso_transfer)(struct usbi_transfer *itransfer);
+	int (*submit_control_transfer)(struct usbi_transfer *itransfer);
+	int (*abort_control)(struct usbi_transfer *itransfer);
+	int (*abort_transfers)(struct usbi_transfer *itransfer);
+	int (*copy_transfer_data)(struct usbi_transfer *itransfer, uint32_t io_size);
+};
+
+extern const struct windows_usb_api_backend usb_api_backend[USB_API_MAX];
+
+#define PRINT_UNSUPPORTED_API(fname)              \
+	usbi_dbg("unsupported API call for '"         \
+		#fname "' (unrecognized device driver)"); \
+	return LIBUSB_ERROR_NOT_SUPPORTED;
+
+/*
+ * private structures definition
+ * with inline pseudo constructors/destructors
+ */
+
+// HCDs
+struct windows_hcd_priv {
+	char *path;
+	struct windows_hcd_priv *next;
+};
+
+static inline void windows_hcd_priv_init(struct windows_hcd_priv* p) {
+	p->path = NULL;
+	p->next = NULL;
+}
+
+static inline void windows_hcd_priv_release(struct windows_hcd_priv* p) {
+	safe_free(p->path);
+}
+
+// TODO (v2+): move hid desc to libusb.h?
+struct libusb_hid_descriptor {
+	uint8_t  bLength;
+	uint8_t  bDescriptorType;
+	uint16_t bcdHID;
+	uint8_t  bCountryCode;
+	uint8_t  bNumDescriptors;
+	uint8_t  bClassDescriptorType;
+	uint16_t wClassDescriptorLength;
+};
+#define LIBUSB_DT_HID_SIZE              9
+#define HID_MAX_CONFIG_DESC_SIZE (LIBUSB_DT_CONFIG_SIZE + LIBUSB_DT_INTERFACE_SIZE \
+	+ LIBUSB_DT_HID_SIZE + 2 * LIBUSB_DT_ENDPOINT_SIZE)
+#define HID_MAX_REPORT_SIZE             1024
+#define HID_IN_EP                       0x81
+#define HID_OUT_EP                      0x02
+#define LIBUSB_REQ_RECIPIENT(request_type) ((request_type) & 0x1F)
+#define LIBUSB_REQ_TYPE(request_type) ((request_type) & (0x03 << 5))
+#define LIBUSB_REQ_IN(request_type) ((request_type) & LIBUSB_ENDPOINT_IN)
+#define LIBUSB_REQ_OUT(request_type) (!LIBUSB_REQ_IN(request_type))
+
+// The following are used for HID reports IOCTLs
+#define HID_CTL_CODE(id) \
+  CTL_CODE (FILE_DEVICE_KEYBOARD, (id), METHOD_NEITHER, FILE_ANY_ACCESS)
+#define HID_BUFFER_CTL_CODE(id) \
+  CTL_CODE (FILE_DEVICE_KEYBOARD, (id), METHOD_BUFFERED, FILE_ANY_ACCESS)
+#define HID_IN_CTL_CODE(id) \
+  CTL_CODE (FILE_DEVICE_KEYBOARD, (id), METHOD_IN_DIRECT, FILE_ANY_ACCESS)
+#define HID_OUT_CTL_CODE(id) \
+  CTL_CODE (FILE_DEVICE_KEYBOARD, (id), METHOD_OUT_DIRECT, FILE_ANY_ACCESS)
+
+#define IOCTL_HID_GET_FEATURE                 HID_OUT_CTL_CODE(100)
+#define IOCTL_HID_GET_INPUT_REPORT            HID_OUT_CTL_CODE(104)
+#define IOCTL_HID_SET_FEATURE                 HID_IN_CTL_CODE(100)
+#define IOCTL_HID_SET_OUTPUT_REPORT           HID_IN_CTL_CODE(101)
+
+enum libusb_hid_request_type {
+	HID_REQ_GET_REPORT = 0x01,
+	HID_REQ_GET_IDLE = 0x02,
+	HID_REQ_GET_PROTOCOL = 0x03,
+	HID_REQ_SET_REPORT = 0x09,
+	HID_REQ_SET_IDLE = 0x0A,
+	HID_REQ_SET_PROTOCOL = 0x0B
+};
+
+enum libusb_hid_report_type {
+	HID_REPORT_TYPE_INPUT = 0x01,
+	HID_REPORT_TYPE_OUTPUT = 0x02,
+	HID_REPORT_TYPE_FEATURE = 0x03
+};
+
+struct hid_device_priv {
+	uint16_t vid;
+	uint16_t pid;
+	uint8_t config;
+	bool uses_report_ids[3];	// input, ouptput, feature
+	uint16_t input_report_size;
+	uint16_t output_report_size;
+	uint16_t feature_report_size;
+	WCHAR string[3][MAX_USB_STRING_LENGTH];
+	uint8_t string_index[3];	// man, prod, ser
+};
+
+typedef struct libusb_device_descriptor USB_DEVICE_DESCRIPTOR, *PUSB_DEVICE_DESCRIPTOR;
+struct windows_device_priv {
+	struct libusb_device *parent_dev;   // access to parent is required for usermode ops
+	ULONG connection_index;             // also required for some usermode ops
+	char *path;                         // path used by Windows to reference the USB node
+	struct windows_usb_api_backend const *apib;
+	struct {
+		char *path;                     // each interface needs a Windows device interface path,
+		struct windows_usb_api_backend const *apib; // an API backend (multiple drivers support),
+		int8_t nb_endpoints;            // and a set of endpoint addresses (USB_MAXENDPOINTS)
+		uint8_t *endpoint;
+		bool restricted_functionality;	// indicates if the interface functionality is restricted
+										// by Windows (eg. HID keyboards or mice cannot do R/W)
+	} usb_interface[USB_MAXINTERFACES];
+	uint8_t composite_api_flags;        // HID and composite devices require additional data
+	struct hid_device_priv *hid;
+	uint8_t active_config;
+	USB_DEVICE_DESCRIPTOR dev_descriptor;
+	unsigned char **config_descriptor;  // list of pointers to the cached config descriptors
+};
+
+static inline void windows_device_priv_init(struct windows_device_priv* p) {
+	int i;
+	p->parent_dev = NULL;
+	p->connection_index = 0;
+	p->path = NULL;
+	p->apib = &usb_api_backend[USB_API_UNSUPPORTED];
+	p->composite_api_flags = 0;
+	p->hid = NULL;
+	p->active_config = 0;
+	p->config_descriptor = NULL;
+	memset(&(p->dev_descriptor), 0, sizeof(USB_DEVICE_DESCRIPTOR));
+	for (i=0; i<USB_MAXINTERFACES; i++) {
+		p->usb_interface[i].path = NULL;
+		p->usb_interface[i].apib = &usb_api_backend[USB_API_UNSUPPORTED];
+		p->usb_interface[i].nb_endpoints = 0;
+		p->usb_interface[i].endpoint = NULL;
+		p->usb_interface[i].restricted_functionality = false;
+	}
+}
+
+static inline void windows_device_priv_release(struct windows_device_priv* p, int num_configurations) {
+	int i;
+	safe_free(p->path);
+	if ((num_configurations > 0) && (p->config_descriptor != NULL)) {
+		for (i=0; i < num_configurations; i++)
+			safe_free(p->config_descriptor[i]);
+	}
+	safe_free(p->config_descriptor);
+	safe_free(p->hid);
+	for (i=0; i<USB_MAXINTERFACES; i++) {
+		safe_free(p->usb_interface[i].path);
+		safe_free(p->usb_interface[i].endpoint);
+	}
+}
+
+static inline struct windows_device_priv *__device_priv(struct libusb_device *dev) {
+	return (struct windows_device_priv *)dev->os_priv;
+}
+
+struct interface_handle_t {
+	HANDLE dev_handle; // WinUSB needs an extra handle for the file
+	HANDLE api_handle; // used by the API to communicate with the device
+};
+
+struct windows_device_handle_priv {
+	int active_interface;
+	struct interface_handle_t interface_handle[USB_MAXINTERFACES];
+#if defined(AUTO_CLAIM)
+	int autoclaim_count[USB_MAXINTERFACES]; // For auto-release
+#endif
+};
+
+static inline struct windows_device_handle_priv *__device_handle_priv(
+	struct libusb_device_handle *handle)
+{
+	return (struct windows_device_handle_priv *) handle->os_priv;
+}
+
+// used for async polling functions
+struct windows_transfer_priv {
+	struct winfd pollable_fd;
+	uint8_t interface_number;
+	uint8_t *hid_buffer; // 1 byte extended data buffer, required for HID
+	uint8_t *hid_dest;   // transfer buffer destination, required for HID
+	size_t hid_expected_size;
+};
+
+// used to match a device driver (including filter drivers) against a supported API
+struct driver_lookup {
+	char list[MAX_KEY_LENGTH+1];// REG_MULTI_SZ list of services (driver) names
+	const DWORD reg_prop;		// SPDRP registry key to use to retreive list
+	const char* designation;	// internal designation (for debug output)
+};
+
+/*
+ * API macros - from libusb-win32 1.x
+ */
+#define DLL_DECLARE(api, ret, name, args)                     \
+  typedef ret (api * __dll_##name##_t)args; __dll_##name##_t name = NULL
+
+#define DLL_LOAD(dll, name, ret_on_failure)                   \
+	do {                                                      \
+		HMODULE h = GetModuleHandle(#dll);                    \
+	if (!h)                                                   \
+		h = LoadLibrary(#dll);                                \
+	if (!h) {                                                 \
+		if (ret_on_failure) { return LIBUSB_ERROR_NOT_FOUND; }\
+		else { break; }                                       \
+	}                                                         \
+	name = (__dll_##name##_t)GetProcAddress(h, #name);        \
+	if (name) break;                                          \
+	name = (__dll_##name##_t)GetProcAddress(h, #name "A");    \
+	if (name) break;                                          \
+	name = (__dll_##name##_t)GetProcAddress(h, #name "W");    \
+	if (name) break;                                          \
+	if(ret_on_failure)                                        \
+		return LIBUSB_ERROR_NOT_FOUND;                        \
+	} while(0)
+
+
+/*
+ * Windows DDK API definitions. Most of it copied from MinGW's includes
+ */
+typedef DWORD DEVNODE, DEVINST;
+typedef DEVNODE *PDEVNODE, *PDEVINST;
+typedef DWORD RETURN_TYPE;
+typedef RETURN_TYPE CONFIGRET;
+
+#define CR_SUCCESS                              0x00000000
+#define CR_NO_SUCH_DEVNODE                      0x0000000D
+
+#define USB_DEVICE_DESCRIPTOR_TYPE              LIBUSB_DT_DEVICE
+#define USB_CONFIGURATION_DESCRIPTOR_TYPE       LIBUSB_DT_CONFIG
+#define USB_STRING_DESCRIPTOR_TYPE              LIBUSB_DT_STRING
+#define USB_INTERFACE_DESCRIPTOR_TYPE           LIBUSB_DT_INTERFACE
+#define USB_ENDPOINT_DESCRIPTOR_TYPE            LIBUSB_DT_ENDPOINT
+
+#define USB_REQUEST_GET_STATUS                  LIBUSB_REQUEST_GET_STATUS
+#define USB_REQUEST_CLEAR_FEATURE               LIBUSB_REQUEST_CLEAR_FEATURE
+#define USB_REQUEST_SET_FEATURE                 LIBUSB_REQUEST_SET_FEATURE
+#define USB_REQUEST_SET_ADDRESS                 LIBUSB_REQUEST_SET_ADDRESS
+#define USB_REQUEST_GET_DESCRIPTOR              LIBUSB_REQUEST_GET_DESCRIPTOR
+#define USB_REQUEST_SET_DESCRIPTOR              LIBUSB_REQUEST_SET_DESCRIPTOR
+#define USB_REQUEST_GET_CONFIGURATION           LIBUSB_REQUEST_GET_CONFIGURATION
+#define USB_REQUEST_SET_CONFIGURATION           LIBUSB_REQUEST_SET_CONFIGURATION
+#define USB_REQUEST_GET_INTERFACE               LIBUSB_REQUEST_GET_INTERFACE
+#define USB_REQUEST_SET_INTERFACE               LIBUSB_REQUEST_SET_INTERFACE
+#define USB_REQUEST_SYNC_FRAME                  LIBUSB_REQUEST_SYNCH_FRAME
+
+#define HCD_GET_ROOT_HUB_NAME                   258
+#define USB_GET_NODE_INFORMATION                258
+#define USB_GET_NODE_CONNECTION_INFORMATION     259
+#define USB_GET_DESCRIPTOR_FROM_NODE_CONNECTION 260
+#define USB_GET_NODE_CONNECTION_NAME            261
+#define USB_GET_HUB_CAPABILITIES                271
+#if !defined(USB_GET_HUB_CAPABILITIES_EX)
+#define USB_GET_HUB_CAPABILITIES_EX             276
+#endif
+
+#ifndef METHOD_BUFFERED
+#define METHOD_BUFFERED                         0
+#endif
+#ifndef FILE_ANY_ACCESS
+#define FILE_ANY_ACCESS                         0x00000000
+#endif
+#ifndef FILE_DEVICE_UNKNOWN
+#define FILE_DEVICE_UNKNOWN                     0x00000022
+#endif
+#ifndef FILE_DEVICE_USB
+#define FILE_DEVICE_USB                         FILE_DEVICE_UNKNOWN
+#endif
+
+#ifndef CTL_CODE
+#define CTL_CODE(DeviceType, Function, Method, Access)( \
+  ((DeviceType) << 16) | ((Access) << 14) | ((Function) << 2) | (Method))
+#endif
+
+typedef enum _USB_CONNECTION_STATUS {
+	NoDeviceConnected,
+	DeviceConnected,
+	DeviceFailedEnumeration,
+	DeviceGeneralFailure,
+	DeviceCausedOvercurrent,
+	DeviceNotEnoughPower,
+	DeviceNotEnoughBandwidth,
+	DeviceHubNestedTooDeeply,
+	DeviceInLegacyHub
+} USB_CONNECTION_STATUS, *PUSB_CONNECTION_STATUS;
+
+typedef enum _USB_HUB_NODE {
+	UsbHub,
+	UsbMIParent
+} USB_HUB_NODE;
+
+/* Cfgmgr32.dll interface */
+DLL_DECLARE(WINAPI, CONFIGRET, CM_Get_Parent, (PDEVINST, DEVINST, ULONG));
+DLL_DECLARE(WINAPI, CONFIGRET, CM_Get_Child, (PDEVINST, DEVINST, ULONG));
+DLL_DECLARE(WINAPI, CONFIGRET, CM_Get_Sibling, (PDEVINST, DEVINST, ULONG));
+DLL_DECLARE(WINAPI, CONFIGRET, CM_Get_Device_IDA, (DEVINST, PCHAR, ULONG, ULONG));
+DLL_DECLARE(WINAPI, CONFIGRET, CM_Get_Device_IDW, (DEVINST, PWCHAR, ULONG, ULONG));
+
+#ifdef UNICODE
+#define CM_Get_Device_ID CM_Get_Device_IDW
+#else
+#define CM_Get_Device_ID CM_Get_Device_IDA
+#endif /* UNICODE */
+
+#define IOCTL_USB_GET_HUB_CAPABILITIES_EX \
+  CTL_CODE( FILE_DEVICE_USB, USB_GET_HUB_CAPABILITIES_EX, METHOD_BUFFERED, FILE_ANY_ACCESS)
+
+#define IOCTL_USB_GET_HUB_CAPABILITIES \
+  CTL_CODE(FILE_DEVICE_USB, USB_GET_HUB_CAPABILITIES, METHOD_BUFFERED, FILE_ANY_ACCESS)
+
+#define IOCTL_USB_GET_DESCRIPTOR_FROM_NODE_CONNECTION \
+  CTL_CODE(FILE_DEVICE_USB, USB_GET_DESCRIPTOR_FROM_NODE_CONNECTION, METHOD_BUFFERED, FILE_ANY_ACCESS)
+
+#define IOCTL_USB_GET_ROOT_HUB_NAME \
+  CTL_CODE(FILE_DEVICE_USB, HCD_GET_ROOT_HUB_NAME, METHOD_BUFFERED, FILE_ANY_ACCESS)
+
+#define IOCTL_USB_GET_NODE_INFORMATION \
+  CTL_CODE(FILE_DEVICE_USB, USB_GET_NODE_INFORMATION, METHOD_BUFFERED, FILE_ANY_ACCESS)
+
+#define IOCTL_USB_GET_NODE_CONNECTION_INFORMATION \
+  CTL_CODE(FILE_DEVICE_USB, USB_GET_NODE_CONNECTION_INFORMATION, METHOD_BUFFERED, FILE_ANY_ACCESS)
+
+#define IOCTL_USB_GET_NODE_CONNECTION_ATTRIBUTES \
+  CTL_CODE(FILE_DEVICE_USB, USB_GET_NODE_CONNECTION_ATTRIBUTES, METHOD_BUFFERED, FILE_ANY_ACCESS)
+
+#define IOCTL_USB_GET_NODE_CONNECTION_NAME \
+  CTL_CODE(FILE_DEVICE_USB, USB_GET_NODE_CONNECTION_NAME, METHOD_BUFFERED, FILE_ANY_ACCESS)
+
+// Most of the structures below need to be packed
+#pragma pack(push, 1)
+
+typedef struct _USB_INTERFACE_DESCRIPTOR {
+  UCHAR  bLength;
+  UCHAR  bDescriptorType;
+  UCHAR  bInterfaceNumber;
+  UCHAR  bAlternateSetting;
+  UCHAR  bNumEndpoints;
+  UCHAR  bInterfaceClass;
+  UCHAR  bInterfaceSubClass;
+  UCHAR  bInterfaceProtocol;
+  UCHAR  iInterface;
+} USB_INTERFACE_DESCRIPTOR, *PUSB_INTERFACE_DESCRIPTOR;
+
+typedef struct _USB_CONFIGURATION_DESCRIPTOR {
+  UCHAR  bLength;
+  UCHAR  bDescriptorType;
+  USHORT wTotalLength;
+  UCHAR  bNumInterfaces;
+  UCHAR  bConfigurationValue;
+  UCHAR  iConfiguration;
+  UCHAR  bmAttributes;
+  UCHAR  MaxPower;
+} USB_CONFIGURATION_DESCRIPTOR, *PUSB_CONFIGURATION_DESCRIPTOR;
+
+typedef struct _USB_CONFIGURATION_DESCRIPTOR_SHORT {
+	struct {
+		ULONG ConnectionIndex;
+		struct {
+			UCHAR bmRequest;
+			UCHAR bRequest;
+			USHORT wValue;
+			USHORT wIndex;
+			USHORT wLength;
+		} SetupPacket;
+	} req;
+	USB_CONFIGURATION_DESCRIPTOR data;
+} USB_CONFIGURATION_DESCRIPTOR_SHORT;
+
+typedef struct _USB_ENDPOINT_DESCRIPTOR {
+  UCHAR  bLength;
+  UCHAR  bDescriptorType;
+  UCHAR  bEndpointAddress;
+  UCHAR  bmAttributes;
+  USHORT  wMaxPacketSize;
+  UCHAR  bInterval;
+} USB_ENDPOINT_DESCRIPTOR, *PUSB_ENDPOINT_DESCRIPTOR;
+
+typedef struct _USB_DESCRIPTOR_REQUEST {
+	ULONG  ConnectionIndex;
+	struct {
+		UCHAR  bmRequest;
+		UCHAR  bRequest;
+		USHORT  wValue;
+		USHORT  wIndex;
+		USHORT  wLength;
+	} SetupPacket;
+//	UCHAR  Data[0];
+} USB_DESCRIPTOR_REQUEST, *PUSB_DESCRIPTOR_REQUEST;
+
+typedef struct _USB_HUB_DESCRIPTOR {
+	UCHAR  bDescriptorLength;
+	UCHAR  bDescriptorType;
+	UCHAR  bNumberOfPorts;
+	USHORT  wHubCharacteristics;
+	UCHAR  bPowerOnToPowerGood;
+	UCHAR  bHubControlCurrent;
+	UCHAR  bRemoveAndPowerMask[64];
+} USB_HUB_DESCRIPTOR, *PUSB_HUB_DESCRIPTOR;
+
+typedef struct _USB_ROOT_HUB_NAME {
+	ULONG  ActualLength;
+	WCHAR  RootHubName[1];
+} USB_ROOT_HUB_NAME, *PUSB_ROOT_HUB_NAME;
+
+typedef struct _USB_ROOT_HUB_NAME_FIXED {
+	ULONG ActualLength;
+	WCHAR RootHubName[MAX_PATH_LENGTH];
+} USB_ROOT_HUB_NAME_FIXED;
+
+typedef struct _USB_NODE_CONNECTION_NAME {
+	ULONG  ConnectionIndex;
+	ULONG  ActualLength;
+	WCHAR  NodeName[1];
+} USB_NODE_CONNECTION_NAME, *PUSB_NODE_CONNECTION_NAME;
+
+typedef struct _USB_NODE_CONNECTION_NAME_FIXED {
+	ULONG ConnectionIndex;
+	ULONG ActualLength;
+	WCHAR NodeName[MAX_PATH_LENGTH];
+} USB_NODE_CONNECTION_NAME_FIXED;
+
+typedef struct _USB_HUB_NAME_FIXED {
+	union {
+		USB_ROOT_HUB_NAME_FIXED root;
+		USB_NODE_CONNECTION_NAME_FIXED node;
+	} u;
+} USB_HUB_NAME_FIXED;
+
+
+typedef struct _USB_HUB_INFORMATION {
+	USB_HUB_DESCRIPTOR  HubDescriptor;
+	BOOLEAN  HubIsBusPowered;
+} USB_HUB_INFORMATION, *PUSB_HUB_INFORMATION;
+
+typedef struct _USB_MI_PARENT_INFORMATION {
+  ULONG  NumberOfInterfaces;
+} USB_MI_PARENT_INFORMATION, *PUSB_MI_PARENT_INFORMATION;
+
+typedef struct _USB_NODE_INFORMATION {
+	USB_HUB_NODE  NodeType;
+	union {
+		USB_HUB_INFORMATION  HubInformation;
+		USB_MI_PARENT_INFORMATION  MiParentInformation;
+	} u;
+} USB_NODE_INFORMATION, *PUSB_NODE_INFORMATION;
+
+typedef struct _USB_PIPE_INFO {
+	USB_ENDPOINT_DESCRIPTOR  EndpointDescriptor;
+	ULONG  ScheduleOffset;
+} USB_PIPE_INFO, *PUSB_PIPE_INFO;
+
+typedef struct _USB_NODE_CONNECTION_INFORMATION {
+	ULONG  ConnectionIndex;
+	USB_DEVICE_DESCRIPTOR  DeviceDescriptor;
+	UCHAR  CurrentConfigurationValue;
+	BOOLEAN  LowSpeed;
+	BOOLEAN  DeviceIsHub;
+	USHORT  DeviceAddress;
+	ULONG  NumberOfOpenPipes;
+	USB_CONNECTION_STATUS  ConnectionStatus;
+//	USB_PIPE_INFO  PipeList[0];
+} USB_NODE_CONNECTION_INFORMATION, *PUSB_NODE_CONNECTION_INFORMATION;
+
+typedef struct _USB_HUB_CAP_FLAGS {
+	ULONG HubIsHighSpeedCapable:1;
+	ULONG HubIsHighSpeed:1;
+	ULONG HubIsMultiTtCapable:1;
+	ULONG HubIsMultiTt:1;
+	ULONG HubIsRoot:1;
+	ULONG HubIsArmedWakeOnConnect:1;
+	ULONG ReservedMBZ:26;
+} USB_HUB_CAP_FLAGS, *PUSB_HUB_CAP_FLAGS;
+
+typedef struct _USB_HUB_CAPABILITIES {
+  ULONG  HubIs2xCapable : 1;
+} USB_HUB_CAPABILITIES, *PUSB_HUB_CAPABILITIES;
+
+typedef struct _USB_HUB_CAPABILITIES_EX {
+	USB_HUB_CAP_FLAGS CapabilityFlags;
+} USB_HUB_CAPABILITIES_EX, *PUSB_HUB_CAPABILITIES_EX;
+
+#pragma pack(pop)
+
+/* winusb.dll interface */
+
+#define SHORT_PACKET_TERMINATE  0x01
+#define AUTO_CLEAR_STALL        0x02
+#define PIPE_TRANSFER_TIMEOUT   0x03
+#define IGNORE_SHORT_PACKETS    0x04
+#define ALLOW_PARTIAL_READS     0x05
+#define AUTO_FLUSH              0x06
+#define RAW_IO                  0x07
+#define MAXIMUM_TRANSFER_SIZE   0x08
+#define AUTO_SUSPEND            0x81
+#define SUSPEND_DELAY           0x83
+#define DEVICE_SPEED            0x01
+#define LowSpeed                0x01
+#define FullSpeed               0x02
+#define HighSpeed               0x03
+
+typedef enum _USBD_PIPE_TYPE {
+	UsbdPipeTypeControl,
+	UsbdPipeTypeIsochronous,
+	UsbdPipeTypeBulk,
+	UsbdPipeTypeInterrupt
+} USBD_PIPE_TYPE;
+
+typedef struct {
+  USBD_PIPE_TYPE PipeType;
+  UCHAR          PipeId;
+  USHORT         MaximumPacketSize;
+  UCHAR          Interval;
+} WINUSB_PIPE_INFORMATION, *PWINUSB_PIPE_INFORMATION;
+
+#pragma pack(1)
+typedef struct {
+  UCHAR  request_type;
+  UCHAR  request;
+  USHORT value;
+  USHORT index;
+  USHORT length;
+} WINUSB_SETUP_PACKET, *PWINUSB_SETUP_PACKET;
+#pragma pack()
+
+typedef void *WINUSB_INTERFACE_HANDLE, *PWINUSB_INTERFACE_HANDLE;
+
+DLL_DECLARE(WINAPI, BOOL, WinUsb_Initialize, (HANDLE, PWINUSB_INTERFACE_HANDLE));
+DLL_DECLARE(WINAPI, BOOL, WinUsb_Free, (WINUSB_INTERFACE_HANDLE));
+DLL_DECLARE(WINAPI, BOOL, WinUsb_GetAssociatedInterface, (WINUSB_INTERFACE_HANDLE, UCHAR, PWINUSB_INTERFACE_HANDLE));
+DLL_DECLARE(WINAPI, BOOL, WinUsb_GetDescriptor, (WINUSB_INTERFACE_HANDLE, UCHAR, UCHAR, USHORT, PUCHAR, ULONG, PULONG));
+DLL_DECLARE(WINAPI, BOOL, WinUsb_QueryInterfaceSettings, (WINUSB_INTERFACE_HANDLE, UCHAR, PUSB_INTERFACE_DESCRIPTOR));
+DLL_DECLARE(WINAPI, BOOL, WinUsb_QueryDeviceInformation, (WINUSB_INTERFACE_HANDLE, ULONG, PULONG, PVOID));
+DLL_DECLARE(WINAPI, BOOL, WinUsb_SetCurrentAlternateSetting, (WINUSB_INTERFACE_HANDLE, UCHAR));
+DLL_DECLARE(WINAPI, BOOL, WinUsb_GetCurrentAlternateSetting, (WINUSB_INTERFACE_HANDLE, PUCHAR));
+DLL_DECLARE(WINAPI, BOOL, WinUsb_QueryPipe, (WINUSB_INTERFACE_HANDLE, UCHAR, UCHAR, PWINUSB_PIPE_INFORMATION));
+DLL_DECLARE(WINAPI, BOOL, WinUsb_SetPipePolicy, (WINUSB_INTERFACE_HANDLE, UCHAR, ULONG, ULONG, PVOID));
+DLL_DECLARE(WINAPI, BOOL, WinUsb_GetPipePolicy, (WINUSB_INTERFACE_HANDLE, UCHAR, ULONG, PULONG, PVOID));
+DLL_DECLARE(WINAPI, BOOL, WinUsb_ReadPipe, (WINUSB_INTERFACE_HANDLE, UCHAR, PUCHAR, ULONG, PULONG, LPOVERLAPPED));
+DLL_DECLARE(WINAPI, BOOL, WinUsb_WritePipe, (WINUSB_INTERFACE_HANDLE, UCHAR, PUCHAR, ULONG, PULONG, LPOVERLAPPED));
+DLL_DECLARE(WINAPI, BOOL, WinUsb_ControlTransfer, (WINUSB_INTERFACE_HANDLE, WINUSB_SETUP_PACKET, PUCHAR, ULONG, PULONG, LPOVERLAPPED));
+DLL_DECLARE(WINAPI, BOOL, WinUsb_ResetPipe, (WINUSB_INTERFACE_HANDLE, UCHAR));
+DLL_DECLARE(WINAPI, BOOL, WinUsb_AbortPipe, (WINUSB_INTERFACE_HANDLE, UCHAR));
+DLL_DECLARE(WINAPI, BOOL, WinUsb_FlushPipe, (WINUSB_INTERFACE_HANDLE, UCHAR));
+
+/* hid.dll interface */
+
+#define HIDP_STATUS_SUCCESS  0x110000
+typedef void* PHIDP_PREPARSED_DATA;
+
+#pragma pack(1)
+typedef struct {
+	ULONG Size;
+	USHORT VendorID;
+	USHORT ProductID;
+	USHORT VersionNumber;
+} HIDD_ATTRIBUTES, *PHIDD_ATTRIBUTES;
+#pragma pack()
+
+typedef USHORT USAGE;
+typedef struct {
+  USAGE Usage;
+  USAGE UsagePage;
+  USHORT InputReportByteLength;
+  USHORT OutputReportByteLength;
+  USHORT FeatureReportByteLength;
+  USHORT Reserved[17];
+  USHORT NumberLinkCollectionNodes;
+  USHORT NumberInputButtonCaps;
+  USHORT NumberInputValueCaps;
+  USHORT NumberInputDataIndices;
+  USHORT NumberOutputButtonCaps;
+  USHORT NumberOutputValueCaps;
+  USHORT NumberOutputDataIndices;
+  USHORT NumberFeatureButtonCaps;
+  USHORT NumberFeatureValueCaps;
+  USHORT NumberFeatureDataIndices;
+} HIDP_CAPS, *PHIDP_CAPS;
+
+typedef enum _HIDP_REPORT_TYPE {
+  HidP_Input,
+  HidP_Output,
+  HidP_Feature
+} HIDP_REPORT_TYPE;
+
+typedef struct _HIDP_VALUE_CAPS {
+  USAGE  UsagePage;
+  UCHAR  ReportID;
+  BOOLEAN  IsAlias;
+  USHORT  BitField;
+  USHORT  LinkCollection;
+  USAGE  LinkUsage;
+  USAGE  LinkUsagePage;
+  BOOLEAN  IsRange;
+  BOOLEAN  IsStringRange;
+  BOOLEAN  IsDesignatorRange;
+  BOOLEAN  IsAbsolute;
+  BOOLEAN  HasNull;
+  UCHAR  Reserved;
+  USHORT  BitSize;
+  USHORT  ReportCount;
+  USHORT  Reserved2[5];
+  ULONG  UnitsExp;
+  ULONG  Units;
+  LONG  LogicalMin, LogicalMax;
+  LONG  PhysicalMin, PhysicalMax;
+	union {
+	  struct {
+		USAGE  UsageMin, UsageMax;
+		USHORT  StringMin, StringMax;
+		USHORT  DesignatorMin, DesignatorMax;
+		USHORT  DataIndexMin, DataIndexMax;
+	  } Range;
+	  struct {
+		USAGE  Usage, Reserved1;
+		USHORT  StringIndex, Reserved2;
+		USHORT  DesignatorIndex, Reserved3;
+		USHORT  DataIndex, Reserved4;
+	  } NotRange;
+	} u;
+} HIDP_VALUE_CAPS, *PHIDP_VALUE_CAPS;
+
+DLL_DECLARE(WINAPI, BOOL, HidD_GetAttributes, (HANDLE, PHIDD_ATTRIBUTES));
+DLL_DECLARE(WINAPI, VOID, HidD_GetHidGuid, (LPGUID));
+DLL_DECLARE(WINAPI, BOOL, HidD_GetPreparsedData, (HANDLE, PHIDP_PREPARSED_DATA *));
+DLL_DECLARE(WINAPI, BOOL, HidD_FreePreparsedData, (PHIDP_PREPARSED_DATA));
+DLL_DECLARE(WINAPI, BOOL, HidD_GetManufacturerString, (HANDLE, PVOID, ULONG));
+DLL_DECLARE(WINAPI, BOOL, HidD_GetProductString, (HANDLE, PVOID, ULONG));
+DLL_DECLARE(WINAPI, BOOL, HidD_GetSerialNumberString, (HANDLE, PVOID, ULONG));
+DLL_DECLARE(WINAPI, LONG, HidP_GetCaps, (PHIDP_PREPARSED_DATA, PHIDP_CAPS));
+DLL_DECLARE(WINAPI, BOOL, HidD_SetNumInputBuffers, (HANDLE, ULONG));
+DLL_DECLARE(WINAPI, BOOL, HidD_SetFeature, (HANDLE, PVOID, ULONG));
+DLL_DECLARE(WINAPI, BOOL, HidD_GetFeature, (HANDLE, PVOID, ULONG));
+DLL_DECLARE(WINAPI, BOOL, HidD_GetPhysicalDescriptor, (HANDLE, PVOID, ULONG));
+DLL_DECLARE(WINAPI, BOOL, HidD_GetInputReport, (HANDLE, PVOID, ULONG));
+DLL_DECLARE(WINAPI, BOOL, HidD_SetOutputReport, (HANDLE, PVOID, ULONG));
+DLL_DECLARE(WINAPI, BOOL, HidD_FlushQueue, (HANDLE));
+DLL_DECLARE(WINAPI, BOOL, HidP_GetValueCaps, (HIDP_REPORT_TYPE, PHIDP_VALUE_CAPS, PULONG, PHIDP_PREPARSED_DATA));