Import libusb 1.0.9-rc3 into third_party

third_party/libusb/libusb/libusb.h

Index: third_party/libusb/libusb/libusb.h
diff --git a/third_party/libusb/libusb/libusb.h b/third_party/libusb/libusb/libusb.h
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index 0000000000000000000000000000000000000000..de2d05050333bd017dad925d35a60edb946acee3
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+++ b/third_party/libusb/libusb/libusb.h
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+/*
+ * 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
+
+#ifdef _MSC_VER
+/* on MS environments, the inline keyword is available in C++ only */
+#define inline __inline
+/* ssize_t is also not available (copy/paste from MinGW) */
+#ifndef _SSIZE_T_DEFINED
+#define _SSIZE_T_DEFINED
+#undef ssize_t
+#ifdef _WIN64
+  typedef __int64 ssize_t;
+#else
+  typedef int ssize_t;
+#endif /* _WIN64 */
+#endif /* _SSIZE_T_DEFINED */
+#endif /* _MSC_VER */
+
+/* stdint.h is also not usually available on MS */
+#if defined(_MSC_VER) && (_MSC_VER < 1600) && (!defined(_STDINT)) && (!defined(_STDINT_H))
+typedef unsigned __int8   uint8_t;
+typedef unsigned __int16  uint16_t;
+typedef unsigned __int32  uint32_t;
+#else
+#include <stdint.h>
+#endif
+
+#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,
+
+	/** Physical */
+	LIBUSB_CLASS_PHYSICAL = 5,
+
+	/** Printer class */
+	LIBUSB_CLASS_PRINTER = 7,
+
+	/** Image class */
+	LIBUSB_CLASS_PTP = 6, /* legacy name from libusb-0.1 usb.h */
+	LIBUSB_CLASS_IMAGE = 6,
+
+	/** Mass storage class */
+	LIBUSB_CLASS_MASS_STORAGE = 8,
+
+	/** Hub class */
+	LIBUSB_CLASS_HUB = 9,
+
+	/** Data class */
+	LIBUSB_CLASS_DATA = 10,
+
+	/** Smart Card */
+	LIBUSB_CLASS_SMART_CARD = 0x0b,
+
+	/** Content Security */
+	LIBUSB_CLASS_CONTENT_SECURITY = 0x0d,
+
+	/** Video */
+	LIBUSB_CLASS_VIDEO = 0x0e,
+
+	/** Personal Healthcare */
+	LIBUSB_CLASS_PERSONAL_HEALTHCARE = 0x0f,
+
+	/** Diagnostic Device */
+	LIBUSB_CLASS_DIAGNOSTIC_DEVICE = 0xdc,
+
+	/** 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 dev
+ * Speed codes. Indicates the speed at which the device is operating.
+ */
+enum libusb_speed {
+    /** The OS doesn't report or know the device speed. */
+    LIBUSB_SPEED_UNKNOWN = 0,
+
+    /** The device is operating at low speed (1.5MBit/s). */
+    LIBUSB_SPEED_LOW = 1,
+
+    /** The device is operating at full speed (12MBit/s). */
+    LIBUSB_SPEED_FULL = 2,
+
+    /** The device is operating at high speed (480MBit/s). */
+    LIBUSB_SPEED_HIGH = 3,
+
+    /** The device is operating at super speed (5000MBit/s). */
+    LIBUSB_SPEED_SUPER = 4,
+};
+
+/** \ingroup misc
+ * Error codes. Most libusb functions return 0 on success or one of these
+ * codes on failure.
+ * You can call \ref libusb_error_name() to retrieve a string representation
+ * of an error code.
+ */
+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,
+
+	/* NB! Remember to update libusb_error_name()
+	   when adding new error codes here. */
+
+	/** Other error */
+	LIBUSB_ERROR_OTHER = -99
+};
+
+/** \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
+	;
+};
+
+/** \ingroup misc
+ * Capabilities supported by this instance of libusb. Test if the running
+ * library supports a given capability by calling
+ * \ref libusb_has_capability().
+ */
+enum libusb_capability {
+	/** The libusb_get_device_speed() API is available. */
+	LIBUSB_CAN_GET_DEVICE_SPEED = 0,
+};
+
+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);
+int LIBUSB_CALL libusb_has_capability(uint32_t capability);
+const char * LIBUSB_CALL libusb_error_name(int 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_device_speed(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_timeout_completed(libusb_context *ctx,
+	struct timeval *tv, int *completed);
+int LIBUSB_CALL libusb_handle_events(libusb_context *ctx);
+int LIBUSB_CALL libusb_handle_events_completed(libusb_context *ctx, int *completed);
+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