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      1 /*
      2  * Public libusb header file
      3  * Copyright (C) 2007-2008 Daniel Drake <dsd (at) gentoo.org>
      4  * Copyright (c) 2001 Johannes Erdfelt <johannes (at) erdfelt.com>
      5  *
      6  * This library is free software; you can redistribute it and/or
      7  * modify it under the terms of the GNU Lesser General Public
      8  * License as published by the Free Software Foundation; either
      9  * version 2.1 of the License, or (at your option) any later version.
     10  *
     11  * This library is distributed in the hope that it will be useful,
     12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
     13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     14  * Lesser General Public License for more details.
     15  *
     16  * You should have received a copy of the GNU Lesser General Public
     17  * License along with this library; if not, write to the Free Software
     18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
     19  */
     20 
     21 #ifndef LIBUSB_H
     22 #define LIBUSB_H
     23 
     24 #ifdef _MSC_VER
     25 /* on MS environments, the inline keyword is available in C++ only */
     26 #define inline __inline
     27 /* ssize_t is also not available (copy/paste from MinGW) */
     28 #ifndef _SSIZE_T_DEFINED
     29 #define _SSIZE_T_DEFINED
     30 #undef ssize_t
     31 #ifdef _WIN64
     32   typedef __int64 ssize_t;
     33 #else
     34   typedef int ssize_t;
     35 #endif /* _WIN64 */
     36 #endif /* _SSIZE_T_DEFINED */
     37 #endif /* _MSC_VER */
     38 
     39 /* stdint.h is also not usually available on MS */
     40 #if defined(_MSC_VER) && (_MSC_VER < 1600) && (!defined(_STDINT)) && (!defined(_STDINT_H))
     41 typedef unsigned __int8   uint8_t;
     42 typedef unsigned __int16  uint16_t;
     43 typedef unsigned __int32  uint32_t;
     44 #else
     45 #include <stdint.h>
     46 #endif
     47 
     48 #include <sys/types.h>
     49 #include <time.h>
     50 #include <limits.h>
     51 
     52 #if defined(__linux) || defined(__APPLE__) || defined(__CYGWIN__)
     53 #include <sys/time.h>
     54 #endif
     55 
     56 /* 'interface' might be defined as a macro on Windows, so we need to
     57  * undefine it so as not to break the current libusb API, because
     58  * libusb_config_descriptor has an 'interface' member
     59  * As this can be problematic if you include windows.h after libusb.h
     60  * in your sources, we force windows.h to be included first. */
     61 #if defined(_WIN32) || defined(__CYGWIN__)
     62 #include <windows.h>
     63 #if defined(interface)
     64 #undef interface
     65 #endif
     66 #endif
     67 
     68 /** \def LIBUSB_CALL
     69  * \ingroup misc
     70  * libusb's Windows calling convention.
     71  *
     72  * Under Windows, the selection of available compilers and configurations
     73  * means that, unlike other platforms, there is not <em>one true calling
     74  * convention</em> (calling convention: the manner in which parameters are
     75  * passed to funcions in the generated assembly code).
     76  *
     77  * Matching the Windows API itself, libusb uses the WINAPI convention (which
     78  * translates to the <tt>stdcall</tt> convention) and guarantees that the
     79  * library is compiled in this way. The public header file also includes
     80  * appropriate annotations so that your own software will use the right
     81  * convention, even if another convention is being used by default within
     82  * your codebase.
     83  *
     84  * The one consideration that you must apply in your software is to mark
     85  * all functions which you use as libusb callbacks with this LIBUSB_CALL
     86  * annotation, so that they too get compiled for the correct calling
     87  * convention.
     88  *
     89  * On non-Windows operating systems, this macro is defined as nothing. This
     90  * means that you can apply it to your code without worrying about
     91  * cross-platform compatibility.
     92  */
     93 /* LIBUSB_CALL must be defined on both definition and declaration of libusb
     94  * functions. You'd think that declaration would be enough, but cygwin will
     95  * complain about conflicting types unless both are marked this way.
     96  * The placement of this macro is important too; it must appear after the
     97  * return type, before the function name. See internal documentation for
     98  * API_EXPORTED.
     99  */
    100 #if defined(_WIN32) || defined(__CYGWIN__)
    101 #define LIBUSB_CALL WINAPI
    102 #else
    103 #define LIBUSB_CALL
    104 #endif
    105 
    106 #ifdef __cplusplus
    107 extern "C" {
    108 #endif
    109 
    110 /** \def libusb_cpu_to_le16
    111  * \ingroup misc
    112  * Convert a 16-bit value from host-endian to little-endian format. On
    113  * little endian systems, this function does nothing. On big endian systems,
    114  * the bytes are swapped.
    115  * \param x the host-endian value to convert
    116  * \returns the value in little-endian byte order
    117  */
    118 static inline uint16_t libusb_cpu_to_le16(const uint16_t x)
    119 {
    120 	union {
    121 		uint8_t  b8[2];
    122 		uint16_t b16;
    123 	} _tmp;
    124 	_tmp.b8[1] = x >> 8;
    125 	_tmp.b8[0] = x & 0xff;
    126 	return _tmp.b16;
    127 }
    128 
    129 /** \def libusb_le16_to_cpu
    130  * \ingroup misc
    131  * Convert a 16-bit value from little-endian to host-endian format. On
    132  * little endian systems, this function does nothing. On big endian systems,
    133  * the bytes are swapped.
    134  * \param x the little-endian value to convert
    135  * \returns the value in host-endian byte order
    136  */
    137 #define libusb_le16_to_cpu libusb_cpu_to_le16
    138 
    139 /* standard USB stuff */
    140 
    141 /** \ingroup desc
    142  * Device and/or Interface Class codes */
    143 enum libusb_class_code {
    144 	/** In the context of a \ref libusb_device_descriptor "device descriptor",
    145 	 * this bDeviceClass value indicates that each interface specifies its
    146 	 * own class information and all interfaces operate independently.
    147 	 */
    148 	LIBUSB_CLASS_PER_INTERFACE = 0,
    149 
    150 	/** Audio class */
    151 	LIBUSB_CLASS_AUDIO = 1,
    152 
    153 	/** Communications class */
    154 	LIBUSB_CLASS_COMM = 2,
    155 
    156 	/** Human Interface Device class */
    157 	LIBUSB_CLASS_HID = 3,
    158 
    159 	/** Physical */
    160 	LIBUSB_CLASS_PHYSICAL = 5,
    161 
    162 	/** Printer class */
    163 	LIBUSB_CLASS_PRINTER = 7,
    164 
    165 	/** Image class */
    166 	LIBUSB_CLASS_PTP = 6, /* legacy name from libusb-0.1 usb.h */
    167 	LIBUSB_CLASS_IMAGE = 6,
    168 
    169 	/** Mass storage class */
    170 	LIBUSB_CLASS_MASS_STORAGE = 8,
    171 
    172 	/** Hub class */
    173 	LIBUSB_CLASS_HUB = 9,
    174 
    175 	/** Data class */
    176 	LIBUSB_CLASS_DATA = 10,
    177 
    178 	/** Smart Card */
    179 	LIBUSB_CLASS_SMART_CARD = 0x0b,
    180 
    181 	/** Content Security */
    182 	LIBUSB_CLASS_CONTENT_SECURITY = 0x0d,
    183 
    184 	/** Video */
    185 	LIBUSB_CLASS_VIDEO = 0x0e,
    186 
    187 	/** Personal Healthcare */
    188 	LIBUSB_CLASS_PERSONAL_HEALTHCARE = 0x0f,
    189 
    190 	/** Diagnostic Device */
    191 	LIBUSB_CLASS_DIAGNOSTIC_DEVICE = 0xdc,
    192 
    193 	/** Wireless class */
    194 	LIBUSB_CLASS_WIRELESS = 0xe0,
    195 
    196 	/** Application class */
    197 	LIBUSB_CLASS_APPLICATION = 0xfe,
    198 
    199 	/** Class is vendor-specific */
    200 	LIBUSB_CLASS_VENDOR_SPEC = 0xff
    201 };
    202 
    203 /** \ingroup desc
    204  * Descriptor types as defined by the USB specification. */
    205 enum libusb_descriptor_type {
    206 	/** Device descriptor. See libusb_device_descriptor. */
    207 	LIBUSB_DT_DEVICE = 0x01,
    208 
    209 	/** Configuration descriptor. See libusb_config_descriptor. */
    210 	LIBUSB_DT_CONFIG = 0x02,
    211 
    212 	/** String descriptor */
    213 	LIBUSB_DT_STRING = 0x03,
    214 
    215 	/** Interface descriptor. See libusb_interface_descriptor. */
    216 	LIBUSB_DT_INTERFACE = 0x04,
    217 
    218 	/** Endpoint descriptor. See libusb_endpoint_descriptor. */
    219 	LIBUSB_DT_ENDPOINT = 0x05,
    220 
    221 	/** HID descriptor */
    222 	LIBUSB_DT_HID = 0x21,
    223 
    224 	/** HID report descriptor */
    225 	LIBUSB_DT_REPORT = 0x22,
    226 
    227 	/** Physical descriptor */
    228 	LIBUSB_DT_PHYSICAL = 0x23,
    229 
    230 	/** Hub descriptor */
    231 	LIBUSB_DT_HUB = 0x29,
    232 };
    233 
    234 /* Descriptor sizes per descriptor type */
    235 #define LIBUSB_DT_DEVICE_SIZE			18
    236 #define LIBUSB_DT_CONFIG_SIZE			9
    237 #define LIBUSB_DT_INTERFACE_SIZE		9
    238 #define LIBUSB_DT_ENDPOINT_SIZE		7
    239 #define LIBUSB_DT_ENDPOINT_AUDIO_SIZE	9	/* Audio extension */
    240 #define LIBUSB_DT_HUB_NONVAR_SIZE		7
    241 
    242 #define LIBUSB_ENDPOINT_ADDRESS_MASK	0x0f    /* in bEndpointAddress */
    243 #define LIBUSB_ENDPOINT_DIR_MASK		0x80
    244 
    245 /** \ingroup desc
    246  * Endpoint direction. Values for bit 7 of the
    247  * \ref libusb_endpoint_descriptor::bEndpointAddress "endpoint address" scheme.
    248  */
    249 enum libusb_endpoint_direction {
    250 	/** In: device-to-host */
    251 	LIBUSB_ENDPOINT_IN = 0x80,
    252 
    253 	/** Out: host-to-device */
    254 	LIBUSB_ENDPOINT_OUT = 0x00
    255 };
    256 
    257 #define LIBUSB_TRANSFER_TYPE_MASK			0x03    /* in bmAttributes */
    258 
    259 /** \ingroup desc
    260  * Endpoint transfer type. Values for bits 0:1 of the
    261  * \ref libusb_endpoint_descriptor::bmAttributes "endpoint attributes" field.
    262  */
    263 enum libusb_transfer_type {
    264 	/** Control endpoint */
    265 	LIBUSB_TRANSFER_TYPE_CONTROL = 0,
    266 
    267 	/** Isochronous endpoint */
    268 	LIBUSB_TRANSFER_TYPE_ISOCHRONOUS = 1,
    269 
    270 	/** Bulk endpoint */
    271 	LIBUSB_TRANSFER_TYPE_BULK = 2,
    272 
    273 	/** Interrupt endpoint */
    274 	LIBUSB_TRANSFER_TYPE_INTERRUPT = 3
    275 };
    276 
    277 /** \ingroup misc
    278  * Standard requests, as defined in table 9-3 of the USB2 specifications */
    279 enum libusb_standard_request {
    280 	/** Request status of the specific recipient */
    281 	LIBUSB_REQUEST_GET_STATUS = 0x00,
    282 
    283 	/** Clear or disable a specific feature */
    284 	LIBUSB_REQUEST_CLEAR_FEATURE = 0x01,
    285 
    286 	/* 0x02 is reserved */
    287 
    288 	/** Set or enable a specific feature */
    289 	LIBUSB_REQUEST_SET_FEATURE = 0x03,
    290 
    291 	/* 0x04 is reserved */
    292 
    293 	/** Set device address for all future accesses */
    294 	LIBUSB_REQUEST_SET_ADDRESS = 0x05,
    295 
    296 	/** Get the specified descriptor */
    297 	LIBUSB_REQUEST_GET_DESCRIPTOR = 0x06,
    298 
    299 	/** Used to update existing descriptors or add new descriptors */
    300 	LIBUSB_REQUEST_SET_DESCRIPTOR = 0x07,
    301 
    302 	/** Get the current device configuration value */
    303 	LIBUSB_REQUEST_GET_CONFIGURATION = 0x08,
    304 
    305 	/** Set device configuration */
    306 	LIBUSB_REQUEST_SET_CONFIGURATION = 0x09,
    307 
    308 	/** Return the selected alternate setting for the specified interface */
    309 	LIBUSB_REQUEST_GET_INTERFACE = 0x0A,
    310 
    311 	/** Select an alternate interface for the specified interface */
    312 	LIBUSB_REQUEST_SET_INTERFACE = 0x0B,
    313 
    314 	/** Set then report an endpoint's synchronization frame */
    315 	LIBUSB_REQUEST_SYNCH_FRAME = 0x0C,
    316 };
    317 
    318 /** \ingroup misc
    319  * Request type bits of the
    320  * \ref libusb_control_setup::bmRequestType "bmRequestType" field in control
    321  * transfers. */
    322 enum libusb_request_type {
    323 	/** Standard */
    324 	LIBUSB_REQUEST_TYPE_STANDARD = (0x00 << 5),
    325 
    326 	/** Class */
    327 	LIBUSB_REQUEST_TYPE_CLASS = (0x01 << 5),
    328 
    329 	/** Vendor */
    330 	LIBUSB_REQUEST_TYPE_VENDOR = (0x02 << 5),
    331 
    332 	/** Reserved */
    333 	LIBUSB_REQUEST_TYPE_RESERVED = (0x03 << 5)
    334 };
    335 
    336 /** \ingroup misc
    337  * Recipient bits of the
    338  * \ref libusb_control_setup::bmRequestType "bmRequestType" field in control
    339  * transfers. Values 4 through 31 are reserved. */
    340 enum libusb_request_recipient {
    341 	/** Device */
    342 	LIBUSB_RECIPIENT_DEVICE = 0x00,
    343 
    344 	/** Interface */
    345 	LIBUSB_RECIPIENT_INTERFACE = 0x01,
    346 
    347 	/** Endpoint */
    348 	LIBUSB_RECIPIENT_ENDPOINT = 0x02,
    349 
    350 	/** Other */
    351 	LIBUSB_RECIPIENT_OTHER = 0x03,
    352 };
    353 
    354 #define LIBUSB_ISO_SYNC_TYPE_MASK		0x0C
    355 
    356 /** \ingroup desc
    357  * Synchronization type for isochronous endpoints. Values for bits 2:3 of the
    358  * \ref libusb_endpoint_descriptor::bmAttributes "bmAttributes" field in
    359  * libusb_endpoint_descriptor.
    360  */
    361 enum libusb_iso_sync_type {
    362 	/** No synchronization */
    363 	LIBUSB_ISO_SYNC_TYPE_NONE = 0,
    364 
    365 	/** Asynchronous */
    366 	LIBUSB_ISO_SYNC_TYPE_ASYNC = 1,
    367 
    368 	/** Adaptive */
    369 	LIBUSB_ISO_SYNC_TYPE_ADAPTIVE = 2,
    370 
    371 	/** Synchronous */
    372 	LIBUSB_ISO_SYNC_TYPE_SYNC = 3
    373 };
    374 
    375 #define LIBUSB_ISO_USAGE_TYPE_MASK 0x30
    376 
    377 /** \ingroup desc
    378  * Usage type for isochronous endpoints. Values for bits 4:5 of the
    379  * \ref libusb_endpoint_descriptor::bmAttributes "bmAttributes" field in
    380  * libusb_endpoint_descriptor.
    381  */
    382 enum libusb_iso_usage_type {
    383 	/** Data endpoint */
    384 	LIBUSB_ISO_USAGE_TYPE_DATA = 0,
    385 
    386 	/** Feedback endpoint */
    387 	LIBUSB_ISO_USAGE_TYPE_FEEDBACK = 1,
    388 
    389 	/** Implicit feedback Data endpoint */
    390 	LIBUSB_ISO_USAGE_TYPE_IMPLICIT = 2,
    391 };
    392 
    393 /** \ingroup desc
    394  * A structure representing the standard USB device descriptor. This
    395  * descriptor is documented in section 9.6.1 of the USB 2.0 specification.
    396  * All multiple-byte fields are represented in host-endian format.
    397  */
    398 struct libusb_device_descriptor {
    399 	/** Size of this descriptor (in bytes) */
    400 	uint8_t  bLength;
    401 
    402 	/** Descriptor type. Will have value
    403 	 * \ref libusb_descriptor_type::LIBUSB_DT_DEVICE LIBUSB_DT_DEVICE in this
    404 	 * context. */
    405 	uint8_t  bDescriptorType;
    406 
    407 	/** USB specification release number in binary-coded decimal. A value of
    408 	 * 0x0200 indicates USB 2.0, 0x0110 indicates USB 1.1, etc. */
    409 	uint16_t bcdUSB;
    410 
    411 	/** USB-IF class code for the device. See \ref libusb_class_code. */
    412 	uint8_t  bDeviceClass;
    413 
    414 	/** USB-IF subclass code for the device, qualified by the bDeviceClass
    415 	 * value */
    416 	uint8_t  bDeviceSubClass;
    417 
    418 	/** USB-IF protocol code for the device, qualified by the bDeviceClass and
    419 	 * bDeviceSubClass values */
    420 	uint8_t  bDeviceProtocol;
    421 
    422 	/** Maximum packet size for endpoint 0 */
    423 	uint8_t  bMaxPacketSize0;
    424 
    425 	/** USB-IF vendor ID */
    426 	uint16_t idVendor;
    427 
    428 	/** USB-IF product ID */
    429 	uint16_t idProduct;
    430 
    431 	/** Device release number in binary-coded decimal */
    432 	uint16_t bcdDevice;
    433 
    434 	/** Index of string descriptor describing manufacturer */
    435 	uint8_t  iManufacturer;
    436 
    437 	/** Index of string descriptor describing product */
    438 	uint8_t  iProduct;
    439 
    440 	/** Index of string descriptor containing device serial number */
    441 	uint8_t  iSerialNumber;
    442 
    443 	/** Number of possible configurations */
    444 	uint8_t  bNumConfigurations;
    445 };
    446 
    447 /** \ingroup desc
    448  * A structure representing the standard USB endpoint descriptor. This
    449  * descriptor is documented in section 9.6.3 of the USB 2.0 specification.
    450  * All multiple-byte fields are represented in host-endian format.
    451  */
    452 struct libusb_endpoint_descriptor {
    453 	/** Size of this descriptor (in bytes) */
    454 	uint8_t  bLength;
    455 
    456 	/** Descriptor type. Will have value
    457 	 * \ref libusb_descriptor_type::LIBUSB_DT_ENDPOINT LIBUSB_DT_ENDPOINT in
    458 	 * this context. */
    459 	uint8_t  bDescriptorType;
    460 
    461 	/** The address of the endpoint described by this descriptor. Bits 0:3 are
    462 	 * the endpoint number. Bits 4:6 are reserved. Bit 7 indicates direction,
    463 	 * see \ref libusb_endpoint_direction.
    464 	 */
    465 	uint8_t  bEndpointAddress;
    466 
    467 	/** Attributes which apply to the endpoint when it is configured using
    468 	 * the bConfigurationValue. Bits 0:1 determine the transfer type and
    469 	 * correspond to \ref libusb_transfer_type. Bits 2:3 are only used for
    470 	 * isochronous endpoints and correspond to \ref libusb_iso_sync_type.
    471 	 * Bits 4:5 are also only used for isochronous endpoints and correspond to
    472 	 * \ref libusb_iso_usage_type. Bits 6:7 are reserved.
    473 	 */
    474 	uint8_t  bmAttributes;
    475 
    476 	/** Maximum packet size this endpoint is capable of sending/receiving. */
    477 	uint16_t wMaxPacketSize;
    478 
    479 	/** Interval for polling endpoint for data transfers. */
    480 	uint8_t  bInterval;
    481 
    482 	/** For audio devices only: the rate at which synchronization feedback
    483 	 * is provided. */
    484 	uint8_t  bRefresh;
    485 
    486 	/** For audio devices only: the address if the synch endpoint */
    487 	uint8_t  bSynchAddress;
    488 
    489 	/** Extra descriptors. If libusb encounters unknown endpoint descriptors,
    490 	 * it will store them here, should you wish to parse them. */
    491 	const unsigned char *extra;
    492 
    493 	/** Length of the extra descriptors, in bytes. */
    494 	int extra_length;
    495 };
    496 
    497 /** \ingroup desc
    498  * A structure representing the standard USB interface descriptor. This
    499  * descriptor is documented in section 9.6.5 of the USB 2.0 specification.
    500  * All multiple-byte fields are represented in host-endian format.
    501  */
    502 struct libusb_interface_descriptor {
    503 	/** Size of this descriptor (in bytes) */
    504 	uint8_t  bLength;
    505 
    506 	/** Descriptor type. Will have value
    507 	 * \ref libusb_descriptor_type::LIBUSB_DT_INTERFACE LIBUSB_DT_INTERFACE
    508 	 * in this context. */
    509 	uint8_t  bDescriptorType;
    510 
    511 	/** Number of this interface */
    512 	uint8_t  bInterfaceNumber;
    513 
    514 	/** Value used to select this alternate setting for this interface */
    515 	uint8_t  bAlternateSetting;
    516 
    517 	/** Number of endpoints used by this interface (excluding the control
    518 	 * endpoint). */
    519 	uint8_t  bNumEndpoints;
    520 
    521 	/** USB-IF class code for this interface. See \ref libusb_class_code. */
    522 	uint8_t  bInterfaceClass;
    523 
    524 	/** USB-IF subclass code for this interface, qualified by the
    525 	 * bInterfaceClass value */
    526 	uint8_t  bInterfaceSubClass;
    527 
    528 	/** USB-IF protocol code for this interface, qualified by the
    529 	 * bInterfaceClass and bInterfaceSubClass values */
    530 	uint8_t  bInterfaceProtocol;
    531 
    532 	/** Index of string descriptor describing this interface */
    533 	uint8_t  iInterface;
    534 
    535 	/** Array of endpoint descriptors. This length of this array is determined
    536 	 * by the bNumEndpoints field. */
    537 	const struct libusb_endpoint_descriptor *endpoint;
    538 
    539 	/** Extra descriptors. If libusb encounters unknown interface descriptors,
    540 	 * it will store them here, should you wish to parse them. */
    541 	const unsigned char *extra;
    542 
    543 	/** Length of the extra descriptors, in bytes. */
    544 	int extra_length;
    545 };
    546 
    547 /** \ingroup desc
    548  * A collection of alternate settings for a particular USB interface.
    549  */
    550 struct libusb_interface {
    551 	/** Array of interface descriptors. The length of this array is determined
    552 	 * by the num_altsetting field. */
    553 	const struct libusb_interface_descriptor *altsetting;
    554 
    555 	/** The number of alternate settings that belong to this interface */
    556 	int num_altsetting;
    557 };
    558 
    559 /** \ingroup desc
    560  * A structure representing the standard USB configuration descriptor. This
    561  * descriptor is documented in section 9.6.3 of the USB 2.0 specification.
    562  * All multiple-byte fields are represented in host-endian format.
    563  */
    564 struct libusb_config_descriptor {
    565 	/** Size of this descriptor (in bytes) */
    566 	uint8_t  bLength;
    567 
    568 	/** Descriptor type. Will have value
    569 	 * \ref libusb_descriptor_type::LIBUSB_DT_CONFIG LIBUSB_DT_CONFIG
    570 	 * in this context. */
    571 	uint8_t  bDescriptorType;
    572 
    573 	/** Total length of data returned for this configuration */
    574 	uint16_t wTotalLength;
    575 
    576 	/** Number of interfaces supported by this configuration */
    577 	uint8_t  bNumInterfaces;
    578 
    579 	/** Identifier value for this configuration */
    580 	uint8_t  bConfigurationValue;
    581 
    582 	/** Index of string descriptor describing this configuration */
    583 	uint8_t  iConfiguration;
    584 
    585 	/** Configuration characteristics */
    586 	uint8_t  bmAttributes;
    587 
    588 	/** Maximum power consumption of the USB device from this bus in this
    589 	 * configuration when the device is fully opreation. Expressed in units
    590 	 * of 2 mA. */
    591 	uint8_t  MaxPower;
    592 
    593 	/** Array of interfaces supported by this configuration. The length of
    594 	 * this array is determined by the bNumInterfaces field. */
    595 	const struct libusb_interface *interface;
    596 
    597 	/** Extra descriptors. If libusb encounters unknown configuration
    598 	 * descriptors, it will store them here, should you wish to parse them. */
    599 	const unsigned char *extra;
    600 
    601 	/** Length of the extra descriptors, in bytes. */
    602 	int extra_length;
    603 };
    604 
    605 /** \ingroup asyncio
    606  * Setup packet for control transfers. */
    607 struct libusb_control_setup {
    608 	/** Request type. Bits 0:4 determine recipient, see
    609 	 * \ref libusb_request_recipient. Bits 5:6 determine type, see
    610 	 * \ref libusb_request_type. Bit 7 determines data transfer direction, see
    611 	 * \ref libusb_endpoint_direction.
    612 	 */
    613 	uint8_t  bmRequestType;
    614 
    615 	/** Request. If the type bits of bmRequestType are equal to
    616 	 * \ref libusb_request_type::LIBUSB_REQUEST_TYPE_STANDARD
    617 	 * "LIBUSB_REQUEST_TYPE_STANDARD" then this field refers to
    618 	 * \ref libusb_standard_request. For other cases, use of this field is
    619 	 * application-specific. */
    620 	uint8_t  bRequest;
    621 
    622 	/** Value. Varies according to request */
    623 	uint16_t wValue;
    624 
    625 	/** Index. Varies according to request, typically used to pass an index
    626 	 * or offset */
    627 	uint16_t wIndex;
    628 
    629 	/** Number of bytes to transfer */
    630 	uint16_t wLength;
    631 };
    632 
    633 #define LIBUSB_CONTROL_SETUP_SIZE (sizeof(struct libusb_control_setup))
    634 
    635 /* libusb */
    636 
    637 struct libusb_context;
    638 struct libusb_device;
    639 struct libusb_device_handle;
    640 
    641 /** \ingroup lib
    642  * Structure representing the libusb version.
    643  */
    644 struct libusb_version {
    645 	/** Library major version. */
    646 	const uint16_t major;
    647 
    648 	/** Library minor version. */
    649 	const uint16_t minor;
    650 
    651 	/** Library micro version. */
    652 	const uint16_t micro;
    653 
    654 	/** Library nano version. This field is only nonzero on Windows. */
    655 	const uint16_t nano;
    656 
    657 	/** Library release candidate suffix string, e.g. "-rc4". */
    658 	const char *rc;
    659 
    660 	/** Output of `git describe --tags` at library build time. */
    661 	const char *describe;
    662 };
    663 
    664 /** \ingroup lib
    665  * Structure representing a libusb session. The concept of individual libusb
    666  * sessions allows for your program to use two libraries (or dynamically
    667  * load two modules) which both independently use libusb. This will prevent
    668  * interference between the individual libusb users - for example
    669  * libusb_set_debug() will not affect the other user of the library, and
    670  * libusb_exit() will not destroy resources that the other user is still
    671  * using.
    672  *
    673  * Sessions are created by libusb_init() and destroyed through libusb_exit().
    674  * If your application is guaranteed to only ever include a single libusb
    675  * user (i.e. you), you do not have to worry about contexts: pass NULL in
    676  * every function call where a context is required. The default context
    677  * will be used.
    678  *
    679  * For more information, see \ref contexts.
    680  */
    681 typedef struct libusb_context libusb_context;
    682 
    683 /** \ingroup dev
    684  * Structure representing a USB device detected on the system. This is an
    685  * opaque type for which you are only ever provided with a pointer, usually
    686  * originating from libusb_get_device_list().
    687  *
    688  * Certain operations can be performed on a device, but in order to do any
    689  * I/O you will have to first obtain a device handle using libusb_open().
    690  *
    691  * Devices are reference counted with libusb_device_ref() and
    692  * libusb_device_unref(), and are freed when the reference count reaches 0.
    693  * New devices presented by libusb_get_device_list() have a reference count of
    694  * 1, and libusb_free_device_list() can optionally decrease the reference count
    695  * on all devices in the list. libusb_open() adds another reference which is
    696  * later destroyed by libusb_close().
    697  */
    698 typedef struct libusb_device libusb_device;
    699 
    700 
    701 /** \ingroup dev
    702  * Structure representing a handle on a USB device. This is an opaque type for
    703  * which you are only ever provided with a pointer, usually originating from
    704  * libusb_open().
    705  *
    706  * A device handle is used to perform I/O and other operations. When finished
    707  * with a device handle, you should call libusb_close().
    708  */
    709 typedef struct libusb_device_handle libusb_device_handle;
    710 
    711 /** \ingroup dev
    712  * Speed codes. Indicates the speed at which the device is operating.
    713  */
    714 enum libusb_speed {
    715     /** The OS doesn't report or know the device speed. */
    716     LIBUSB_SPEED_UNKNOWN = 0,
    717 
    718     /** The device is operating at low speed (1.5MBit/s). */
    719     LIBUSB_SPEED_LOW = 1,
    720 
    721     /** The device is operating at full speed (12MBit/s). */
    722     LIBUSB_SPEED_FULL = 2,
    723 
    724     /** The device is operating at high speed (480MBit/s). */
    725     LIBUSB_SPEED_HIGH = 3,
    726 
    727     /** The device is operating at super speed (5000MBit/s). */
    728     LIBUSB_SPEED_SUPER = 4,
    729 };
    730 
    731 /** \ingroup misc
    732  * Error codes. Most libusb functions return 0 on success or one of these
    733  * codes on failure.
    734  * You can call \ref libusb_error_name() to retrieve a string representation
    735  * of an error code.
    736  */
    737 enum libusb_error {
    738 	/** Success (no error) */
    739 	LIBUSB_SUCCESS = 0,
    740 
    741 	/** Input/output error */
    742 	LIBUSB_ERROR_IO = -1,
    743 
    744 	/** Invalid parameter */
    745 	LIBUSB_ERROR_INVALID_PARAM = -2,
    746 
    747 	/** Access denied (insufficient permissions) */
    748 	LIBUSB_ERROR_ACCESS = -3,
    749 
    750 	/** No such device (it may have been disconnected) */
    751 	LIBUSB_ERROR_NO_DEVICE = -4,
    752 
    753 	/** Entity not found */
    754 	LIBUSB_ERROR_NOT_FOUND = -5,
    755 
    756 	/** Resource busy */
    757 	LIBUSB_ERROR_BUSY = -6,
    758 
    759 	/** Operation timed out */
    760 	LIBUSB_ERROR_TIMEOUT = -7,
    761 
    762 	/** Overflow */
    763 	LIBUSB_ERROR_OVERFLOW = -8,
    764 
    765 	/** Pipe error */
    766 	LIBUSB_ERROR_PIPE = -9,
    767 
    768 	/** System call interrupted (perhaps due to signal) */
    769 	LIBUSB_ERROR_INTERRUPTED = -10,
    770 
    771 	/** Insufficient memory */
    772 	LIBUSB_ERROR_NO_MEM = -11,
    773 
    774 	/** Operation not supported or unimplemented on this platform */
    775 	LIBUSB_ERROR_NOT_SUPPORTED = -12,
    776 
    777 	/* NB! Remember to update libusb_error_name()
    778 	   when adding new error codes here. */
    779 
    780 	/** Other error */
    781 	LIBUSB_ERROR_OTHER = -99,
    782 };
    783 
    784 /** \ingroup asyncio
    785  * Transfer status codes */
    786 enum libusb_transfer_status {
    787 	/** Transfer completed without error. Note that this does not indicate
    788 	 * that the entire amount of requested data was transferred. */
    789 	LIBUSB_TRANSFER_COMPLETED,
    790 
    791 	/** Transfer failed */
    792 	LIBUSB_TRANSFER_ERROR,
    793 
    794 	/** Transfer timed out */
    795 	LIBUSB_TRANSFER_TIMED_OUT,
    796 
    797 	/** Transfer was cancelled */
    798 	LIBUSB_TRANSFER_CANCELLED,
    799 
    800 	/** For bulk/interrupt endpoints: halt condition detected (endpoint
    801 	 * stalled). For control endpoints: control request not supported. */
    802 	LIBUSB_TRANSFER_STALL,
    803 
    804 	/** Device was disconnected */
    805 	LIBUSB_TRANSFER_NO_DEVICE,
    806 
    807 	/** Device sent more data than requested */
    808 	LIBUSB_TRANSFER_OVERFLOW,
    809 };
    810 
    811 /** \ingroup asyncio
    812  * libusb_transfer.flags values */
    813 enum libusb_transfer_flags {
    814 	/** Report short frames as errors */
    815 	LIBUSB_TRANSFER_SHORT_NOT_OK = 1<<0,
    816 
    817 	/** Automatically free() transfer buffer during libusb_free_transfer() */
    818 	LIBUSB_TRANSFER_FREE_BUFFER = 1<<1,
    819 
    820 	/** Automatically call libusb_free_transfer() after callback returns.
    821 	 * If this flag is set, it is illegal to call libusb_free_transfer()
    822 	 * from your transfer callback, as this will result in a double-free
    823 	 * when this flag is acted upon. */
    824 	LIBUSB_TRANSFER_FREE_TRANSFER = 1<<2,
    825 
    826 	/** Terminate transfers that are a multiple of the endpoint's
    827 	 * wMaxPacketSize with an extra zero length packet. This is useful
    828 	 * when a device protocol mandates that each logical request is
    829 	 * terminated by an incomplete packet (i.e. the logical requests are
    830 	 * not separated by other means).
    831 	 *
    832 	 * This flag only affects host-to-device transfers to bulk and interrupt
    833 	 * endpoints. In other situations, it is ignored.
    834 	 *
    835 	 * This flag only affects transfers with a length that is a multiple of
    836 	 * the endpoint's wMaxPacketSize. On transfers of other lengths, this
    837 	 * flag has no effect. Therefore, if you are working with a device that
    838 	 * needs a ZLP whenever the end of the logical request falls on a packet
    839 	 * boundary, then it is sensible to set this flag on <em>every</em>
    840 	 * transfer (you do not have to worry about only setting it on transfers
    841 	 * that end on the boundary).
    842 	 *
    843 	 * This flag is currently only supported on Linux.
    844 	 * On other systems, libusb_submit_transfer() will return
    845 	 * LIBUSB_ERROR_NOT_SUPPORTED for every transfer where this flag is set.
    846 	 *
    847 	 * Available since libusb-1.0.9.
    848 	 */
    849 	LIBUSB_TRANSFER_ADD_ZERO_PACKET = 1 << 3,
    850 };
    851 
    852 /** \ingroup asyncio
    853  * Isochronous packet descriptor. */
    854 struct libusb_iso_packet_descriptor {
    855 	/** Length of data to request in this packet */
    856 	unsigned int length;
    857 
    858 	/** Amount of data that was actually transferred */
    859 	unsigned int actual_length;
    860 
    861 	/** Status code for this packet */
    862 	enum libusb_transfer_status status;
    863 };
    864 
    865 struct libusb_transfer;
    866 
    867 /** \ingroup asyncio
    868  * Asynchronous transfer callback function type. When submitting asynchronous
    869  * transfers, you pass a pointer to a callback function of this type via the
    870  * \ref libusb_transfer::callback "callback" member of the libusb_transfer
    871  * structure. libusb will call this function later, when the transfer has
    872  * completed or failed. See \ref asyncio for more information.
    873  * \param transfer The libusb_transfer struct the callback function is being
    874  * notified about.
    875  */
    876 typedef void (LIBUSB_CALL *libusb_transfer_cb_fn)(struct libusb_transfer *transfer);
    877 
    878 /** \ingroup asyncio
    879  * The generic USB transfer structure. The user populates this structure and
    880  * then submits it in order to request a transfer. After the transfer has
    881  * completed, the library populates the transfer with the results and passes
    882  * it back to the user.
    883  */
    884 struct libusb_transfer {
    885 	/** Handle of the device that this transfer will be submitted to */
    886 	libusb_device_handle *dev_handle;
    887 
    888 	/** A bitwise OR combination of \ref libusb_transfer_flags. */
    889 	uint8_t flags;
    890 
    891 	/** Address of the endpoint where this transfer will be sent. */
    892 	unsigned char endpoint;
    893 
    894 	/** Type of the endpoint from \ref libusb_transfer_type */
    895 	unsigned char type;
    896 
    897 	/** Timeout for this transfer in millseconds. A value of 0 indicates no
    898 	 * timeout. */
    899 	unsigned int timeout;
    900 
    901 	/** The status of the transfer. Read-only, and only for use within
    902 	 * transfer callback function.
    903 	 *
    904 	 * If this is an isochronous transfer, this field may read COMPLETED even
    905 	 * if there were errors in the frames. Use the
    906 	 * \ref libusb_iso_packet_descriptor::status "status" field in each packet
    907 	 * to determine if errors occurred. */
    908 	enum libusb_transfer_status status;
    909 
    910 	/** Length of the data buffer */
    911 	int length;
    912 
    913 	/** Actual length of data that was transferred. Read-only, and only for
    914 	 * use within transfer callback function. Not valid for isochronous
    915 	 * endpoint transfers. */
    916 	int actual_length;
    917 
    918 	/** Callback function. This will be invoked when the transfer completes,
    919 	 * fails, or is cancelled. */
    920 	libusb_transfer_cb_fn callback;
    921 
    922 	/** User context data to pass to the callback function. */
    923 	void *user_data;
    924 
    925 	/** Data buffer */
    926 	unsigned char *buffer;
    927 
    928 	/** Number of isochronous packets. Only used for I/O with isochronous
    929 	 * endpoints. */
    930 	int num_iso_packets;
    931 
    932 	/** Isochronous packet descriptors, for isochronous transfers only. */
    933 	struct libusb_iso_packet_descriptor iso_packet_desc
    934 #if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)
    935 	[] /* valid C99 code */
    936 #else
    937 	[0] /* non-standard, but usually working code */
    938 #endif
    939 	;
    940 };
    941 
    942 /** \ingroup misc
    943  * Capabilities supported by this instance of libusb. Test if the loaded
    944  * library supports a given capability by calling
    945  * \ref libusb_has_capability().
    946  */
    947 enum libusb_capability {
    948 	/** The libusb_has_capability() API is available. */
    949 	LIBUSB_CAP_HAS_CAPABILITY = 0,
    950 };
    951 
    952 int LIBUSB_CALL libusb_init(libusb_context **ctx);
    953 void LIBUSB_CALL libusb_exit(libusb_context *ctx);
    954 void LIBUSB_CALL libusb_set_debug(libusb_context *ctx, int level);
    955 const struct libusb_version * LIBUSB_CALL libusb_get_version(void);
    956 int LIBUSB_CALL libusb_has_capability(uint32_t capability);
    957 const char * LIBUSB_CALL libusb_error_name(int errcode);
    958 
    959 ssize_t LIBUSB_CALL libusb_get_device_list(libusb_context *ctx,
    960 	libusb_device ***list);
    961 void LIBUSB_CALL libusb_free_device_list(libusb_device **list,
    962 	int unref_devices);
    963 libusb_device * LIBUSB_CALL libusb_ref_device(libusb_device *dev);
    964 void LIBUSB_CALL libusb_unref_device(libusb_device *dev);
    965 
    966 int LIBUSB_CALL libusb_get_configuration(libusb_device_handle *dev,
    967 	int *config);
    968 int LIBUSB_CALL libusb_get_device_descriptor(libusb_device *dev,
    969 	struct libusb_device_descriptor *desc);
    970 int LIBUSB_CALL libusb_get_active_config_descriptor(libusb_device *dev,
    971 	struct libusb_config_descriptor **config);
    972 int LIBUSB_CALL libusb_get_config_descriptor(libusb_device *dev,
    973 	uint8_t config_index, struct libusb_config_descriptor **config);
    974 int LIBUSB_CALL libusb_get_config_descriptor_by_value(libusb_device *dev,
    975 	uint8_t bConfigurationValue, struct libusb_config_descriptor **config);
    976 void LIBUSB_CALL libusb_free_config_descriptor(
    977 	struct libusb_config_descriptor *config);
    978 uint8_t LIBUSB_CALL libusb_get_bus_number(libusb_device *dev);
    979 uint8_t LIBUSB_CALL libusb_get_device_address(libusb_device *dev);
    980 int LIBUSB_CALL libusb_get_device_speed(libusb_device *dev);
    981 int LIBUSB_CALL libusb_get_max_packet_size(libusb_device *dev,
    982 	unsigned char endpoint);
    983 int LIBUSB_CALL libusb_get_max_iso_packet_size(libusb_device *dev,
    984 	unsigned char endpoint);
    985 
    986 int LIBUSB_CALL libusb_open(libusb_device *dev, libusb_device_handle **handle);
    987 void LIBUSB_CALL libusb_close(libusb_device_handle *dev_handle);
    988 libusb_device * LIBUSB_CALL libusb_get_device(libusb_device_handle *dev_handle);
    989 
    990 int LIBUSB_CALL libusb_set_configuration(libusb_device_handle *dev,
    991 	int configuration);
    992 int LIBUSB_CALL libusb_claim_interface(libusb_device_handle *dev,
    993 	int interface_number);
    994 int LIBUSB_CALL libusb_release_interface(libusb_device_handle *dev,
    995 	int interface_number);
    996 
    997 libusb_device_handle * LIBUSB_CALL libusb_open_device_with_vid_pid(
    998 	libusb_context *ctx, uint16_t vendor_id, uint16_t product_id);
    999 
   1000 int LIBUSB_CALL libusb_set_interface_alt_setting(libusb_device_handle *dev,
   1001 	int interface_number, int alternate_setting);
   1002 int LIBUSB_CALL libusb_clear_halt(libusb_device_handle *dev,
   1003 	unsigned char endpoint);
   1004 int LIBUSB_CALL libusb_reset_device(libusb_device_handle *dev);
   1005 
   1006 int LIBUSB_CALL libusb_kernel_driver_active(libusb_device_handle *dev,
   1007 	int interface_number);
   1008 int LIBUSB_CALL libusb_detach_kernel_driver(libusb_device_handle *dev,
   1009 	int interface_number);
   1010 int LIBUSB_CALL libusb_attach_kernel_driver(libusb_device_handle *dev,
   1011 	int interface_number);
   1012 
   1013 /* async I/O */
   1014 
   1015 /** \ingroup asyncio
   1016  * Get the data section of a control transfer. This convenience function is here
   1017  * to remind you that the data does not start until 8 bytes into the actual
   1018  * buffer, as the setup packet comes first.
   1019  *
   1020  * Calling this function only makes sense from a transfer callback function,
   1021  * or situations where you have already allocated a suitably sized buffer at
   1022  * transfer->buffer.
   1023  *
   1024  * \param transfer a transfer
   1025  * \returns pointer to the first byte of the data section
   1026  */
   1027 static inline unsigned char *libusb_control_transfer_get_data(
   1028 	struct libusb_transfer *transfer)
   1029 {
   1030 	return transfer->buffer + LIBUSB_CONTROL_SETUP_SIZE;
   1031 }
   1032 
   1033 /** \ingroup asyncio
   1034  * Get the control setup packet of a control transfer. This convenience
   1035  * function is here to remind you that the control setup occupies the first
   1036  * 8 bytes of the transfer data buffer.
   1037  *
   1038  * Calling this function only makes sense from a transfer callback function,
   1039  * or situations where you have already allocated a suitably sized buffer at
   1040  * transfer->buffer.
   1041  *
   1042  * \param transfer a transfer
   1043  * \returns a casted pointer to the start of the transfer data buffer
   1044  */
   1045 static inline struct libusb_control_setup *libusb_control_transfer_get_setup(
   1046 	struct libusb_transfer *transfer)
   1047 {
   1048 	return (struct libusb_control_setup *) transfer->buffer;
   1049 }
   1050 
   1051 /** \ingroup asyncio
   1052  * Helper function to populate the setup packet (first 8 bytes of the data
   1053  * buffer) for a control transfer. The wIndex, wValue and wLength values should
   1054  * be given in host-endian byte order.
   1055  *
   1056  * \param buffer buffer to output the setup packet into
   1057  * \param bmRequestType see the
   1058  * \ref libusb_control_setup::bmRequestType "bmRequestType" field of
   1059  * \ref libusb_control_setup
   1060  * \param bRequest see the
   1061  * \ref libusb_control_setup::bRequest "bRequest" field of
   1062  * \ref libusb_control_setup
   1063  * \param wValue see the
   1064  * \ref libusb_control_setup::wValue "wValue" field of
   1065  * \ref libusb_control_setup
   1066  * \param wIndex see the
   1067  * \ref libusb_control_setup::wIndex "wIndex" field of
   1068  * \ref libusb_control_setup
   1069  * \param wLength see the
   1070  * \ref libusb_control_setup::wLength "wLength" field of
   1071  * \ref libusb_control_setup
   1072  */
   1073 static inline void libusb_fill_control_setup(unsigned char *buffer,
   1074 	uint8_t bmRequestType, uint8_t bRequest, uint16_t wValue, uint16_t wIndex,
   1075 	uint16_t wLength)
   1076 {
   1077 	struct libusb_control_setup *setup = (struct libusb_control_setup *) buffer;
   1078 	setup->bmRequestType = bmRequestType;
   1079 	setup->bRequest = bRequest;
   1080 	setup->wValue = libusb_cpu_to_le16(wValue);
   1081 	setup->wIndex = libusb_cpu_to_le16(wIndex);
   1082 	setup->wLength = libusb_cpu_to_le16(wLength);
   1083 }
   1084 
   1085 struct libusb_transfer * LIBUSB_CALL libusb_alloc_transfer(int iso_packets);
   1086 int LIBUSB_CALL libusb_submit_transfer(struct libusb_transfer *transfer);
   1087 int LIBUSB_CALL libusb_cancel_transfer(struct libusb_transfer *transfer);
   1088 void LIBUSB_CALL libusb_free_transfer(struct libusb_transfer *transfer);
   1089 
   1090 /** \ingroup asyncio
   1091  * Helper function to populate the required \ref libusb_transfer fields
   1092  * for a control transfer.
   1093  *
   1094  * If you pass a transfer buffer to this function, the first 8 bytes will
   1095  * be interpreted as a control setup packet, and the wLength field will be
   1096  * used to automatically populate the \ref libusb_transfer::length "length"
   1097  * field of the transfer. Therefore the recommended approach is:
   1098  * -# Allocate a suitably sized data buffer (including space for control setup)
   1099  * -# Call libusb_fill_control_setup()
   1100  * -# If this is a host-to-device transfer with a data stage, put the data
   1101  *    in place after the setup packet
   1102  * -# Call this function
   1103  * -# Call libusb_submit_transfer()
   1104  *
   1105  * It is also legal to pass a NULL buffer to this function, in which case this
   1106  * function will not attempt to populate the length field. Remember that you
   1107  * must then populate the buffer and length fields later.
   1108  *
   1109  * \param transfer the transfer to populate
   1110  * \param dev_handle handle of the device that will handle the transfer
   1111  * \param buffer data buffer. If provided, this function will interpret the
   1112  * first 8 bytes as a setup packet and infer the transfer length from that.
   1113  * \param callback callback function to be invoked on transfer completion
   1114  * \param user_data user data to pass to callback function
   1115  * \param timeout timeout for the transfer in milliseconds
   1116  */
   1117 static inline void libusb_fill_control_transfer(
   1118 	struct libusb_transfer *transfer, libusb_device_handle *dev_handle,
   1119 	unsigned char *buffer, libusb_transfer_cb_fn callback, void *user_data,
   1120 	unsigned int timeout)
   1121 {
   1122 	struct libusb_control_setup *setup = (struct libusb_control_setup *) buffer;
   1123 	transfer->dev_handle = dev_handle;
   1124 	transfer->endpoint = 0;
   1125 	transfer->type = LIBUSB_TRANSFER_TYPE_CONTROL;
   1126 	transfer->timeout = timeout;
   1127 	transfer->buffer = buffer;
   1128 	if (setup)
   1129 		transfer->length = LIBUSB_CONTROL_SETUP_SIZE
   1130 			+ libusb_le16_to_cpu(setup->wLength);
   1131 	transfer->user_data = user_data;
   1132 	transfer->callback = callback;
   1133 }
   1134 
   1135 /** \ingroup asyncio
   1136  * Helper function to populate the required \ref libusb_transfer fields
   1137  * for a bulk transfer.
   1138  *
   1139  * \param transfer the transfer to populate
   1140  * \param dev_handle handle of the device that will handle the transfer
   1141  * \param endpoint address of the endpoint where this transfer will be sent
   1142  * \param buffer data buffer
   1143  * \param length length of data buffer
   1144  * \param callback callback function to be invoked on transfer completion
   1145  * \param user_data user data to pass to callback function
   1146  * \param timeout timeout for the transfer in milliseconds
   1147  */
   1148 static inline void libusb_fill_bulk_transfer(struct libusb_transfer *transfer,
   1149 	libusb_device_handle *dev_handle, unsigned char endpoint,
   1150 	unsigned char *buffer, int length, libusb_transfer_cb_fn callback,
   1151 	void *user_data, unsigned int timeout)
   1152 {
   1153 	transfer->dev_handle = dev_handle;
   1154 	transfer->endpoint = endpoint;
   1155 	transfer->type = LIBUSB_TRANSFER_TYPE_BULK;
   1156 	transfer->timeout = timeout;
   1157 	transfer->buffer = buffer;
   1158 	transfer->length = length;
   1159 	transfer->user_data = user_data;
   1160 	transfer->callback = callback;
   1161 }
   1162 
   1163 /** \ingroup asyncio
   1164  * Helper function to populate the required \ref libusb_transfer fields
   1165  * for an interrupt transfer.
   1166  *
   1167  * \param transfer the transfer to populate
   1168  * \param dev_handle handle of the device that will handle the transfer
   1169  * \param endpoint address of the endpoint where this transfer will be sent
   1170  * \param buffer data buffer
   1171  * \param length length of data buffer
   1172  * \param callback callback function to be invoked on transfer completion
   1173  * \param user_data user data to pass to callback function
   1174  * \param timeout timeout for the transfer in milliseconds
   1175  */
   1176 static inline void libusb_fill_interrupt_transfer(
   1177 	struct libusb_transfer *transfer, libusb_device_handle *dev_handle,
   1178 	unsigned char endpoint, unsigned char *buffer, int length,
   1179 	libusb_transfer_cb_fn callback, void *user_data, unsigned int timeout)
   1180 {
   1181 	transfer->dev_handle = dev_handle;
   1182 	transfer->endpoint = endpoint;
   1183 	transfer->type = LIBUSB_TRANSFER_TYPE_INTERRUPT;
   1184 	transfer->timeout = timeout;
   1185 	transfer->buffer = buffer;
   1186 	transfer->length = length;
   1187 	transfer->user_data = user_data;
   1188 	transfer->callback = callback;
   1189 }
   1190 
   1191 /** \ingroup asyncio
   1192  * Helper function to populate the required \ref libusb_transfer fields
   1193  * for an isochronous transfer.
   1194  *
   1195  * \param transfer the transfer to populate
   1196  * \param dev_handle handle of the device that will handle the transfer
   1197  * \param endpoint address of the endpoint where this transfer will be sent
   1198  * \param buffer data buffer
   1199  * \param length length of data buffer
   1200  * \param num_iso_packets the number of isochronous packets
   1201  * \param callback callback function to be invoked on transfer completion
   1202  * \param user_data user data to pass to callback function
   1203  * \param timeout timeout for the transfer in milliseconds
   1204  */
   1205 static inline void libusb_fill_iso_transfer(struct libusb_transfer *transfer,
   1206 	libusb_device_handle *dev_handle, unsigned char endpoint,
   1207 	unsigned char *buffer, int length, int num_iso_packets,
   1208 	libusb_transfer_cb_fn callback, void *user_data, unsigned int timeout)
   1209 {
   1210 	transfer->dev_handle = dev_handle;
   1211 	transfer->endpoint = endpoint;
   1212 	transfer->type = LIBUSB_TRANSFER_TYPE_ISOCHRONOUS;
   1213 	transfer->timeout = timeout;
   1214 	transfer->buffer = buffer;
   1215 	transfer->length = length;
   1216 	transfer->num_iso_packets = num_iso_packets;
   1217 	transfer->user_data = user_data;
   1218 	transfer->callback = callback;
   1219 }
   1220 
   1221 /** \ingroup asyncio
   1222  * Convenience function to set the length of all packets in an isochronous
   1223  * transfer, based on the num_iso_packets field in the transfer structure.
   1224  *
   1225  * \param transfer a transfer
   1226  * \param length the length to set in each isochronous packet descriptor
   1227  * \see libusb_get_max_packet_size()
   1228  */
   1229 static inline void libusb_set_iso_packet_lengths(
   1230 	struct libusb_transfer *transfer, unsigned int length)
   1231 {
   1232 	int i;
   1233 	for (i = 0; i < transfer->num_iso_packets; i++)
   1234 		transfer->iso_packet_desc[i].length = length;
   1235 }
   1236 
   1237 unsigned char * LIBUSB_CALL libusb_get_iso_packet_buffer(
   1238 	struct libusb_transfer *transfer, unsigned int packet);
   1239 
   1240 unsigned char * LIBUSB_CALL libusb_get_iso_packet_buffer_simple(
   1241 	struct libusb_transfer *transfer, unsigned int packet);
   1242 
   1243 /* sync I/O */
   1244 
   1245 int LIBUSB_CALL libusb_control_transfer(libusb_device_handle *dev_handle,
   1246 	uint8_t request_type, uint8_t bRequest, uint16_t wValue, uint16_t wIndex,
   1247 	unsigned char *data, uint16_t wLength, unsigned int timeout);
   1248 
   1249 int LIBUSB_CALL libusb_bulk_transfer(libusb_device_handle *dev_handle,
   1250 	unsigned char endpoint, unsigned char *data, int length,
   1251 	int *actual_length, unsigned int timeout);
   1252 
   1253 int LIBUSB_CALL libusb_interrupt_transfer(libusb_device_handle *dev_handle,
   1254 	unsigned char endpoint, unsigned char *data, int length,
   1255 	int *actual_length, unsigned int timeout);
   1256 
   1257 /** \ingroup desc
   1258  * Retrieve a descriptor from the default control pipe.
   1259  * This is a convenience function which formulates the appropriate control
   1260  * message to retrieve the descriptor.
   1261  *
   1262  * \param dev a device handle
   1263  * \param desc_type the descriptor type, see \ref libusb_descriptor_type
   1264  * \param desc_index the index of the descriptor to retrieve
   1265  * \param data output buffer for descriptor
   1266  * \param length size of data buffer
   1267  * \returns number of bytes returned in data, or LIBUSB_ERROR code on failure
   1268  */
   1269 static inline int libusb_get_descriptor(libusb_device_handle *dev,
   1270 	uint8_t desc_type, uint8_t desc_index, unsigned char *data, int length)
   1271 {
   1272 	return libusb_control_transfer(dev, LIBUSB_ENDPOINT_IN,
   1273 		LIBUSB_REQUEST_GET_DESCRIPTOR, (desc_type << 8) | desc_index, 0, data,
   1274 		(uint16_t) length, 1000);
   1275 }
   1276 
   1277 /** \ingroup desc
   1278  * Retrieve a descriptor from a device.
   1279  * This is a convenience function which formulates the appropriate control
   1280  * message to retrieve the descriptor. The string returned is Unicode, as
   1281  * detailed in the USB specifications.
   1282  *
   1283  * \param dev a device handle
   1284  * \param desc_index the index of the descriptor to retrieve
   1285  * \param langid the language ID for the string descriptor
   1286  * \param data output buffer for descriptor
   1287  * \param length size of data buffer
   1288  * \returns number of bytes returned in data, or LIBUSB_ERROR code on failure
   1289  * \see libusb_get_string_descriptor_ascii()
   1290  */
   1291 static inline int libusb_get_string_descriptor(libusb_device_handle *dev,
   1292 	uint8_t desc_index, uint16_t langid, unsigned char *data, int length)
   1293 {
   1294 	return libusb_control_transfer(dev, LIBUSB_ENDPOINT_IN,
   1295 		LIBUSB_REQUEST_GET_DESCRIPTOR, (uint16_t)((LIBUSB_DT_STRING << 8) | desc_index),
   1296 		langid, data, (uint16_t) length, 1000);
   1297 }
   1298 
   1299 int LIBUSB_CALL libusb_get_string_descriptor_ascii(libusb_device_handle *dev,
   1300 	uint8_t desc_index, unsigned char *data, int length);
   1301 
   1302 /* polling and timeouts */
   1303 
   1304 int LIBUSB_CALL libusb_try_lock_events(libusb_context *ctx);
   1305 void LIBUSB_CALL libusb_lock_events(libusb_context *ctx);
   1306 void LIBUSB_CALL libusb_unlock_events(libusb_context *ctx);
   1307 int LIBUSB_CALL libusb_event_handling_ok(libusb_context *ctx);
   1308 int LIBUSB_CALL libusb_event_handler_active(libusb_context *ctx);
   1309 void LIBUSB_CALL libusb_lock_event_waiters(libusb_context *ctx);
   1310 void LIBUSB_CALL libusb_unlock_event_waiters(libusb_context *ctx);
   1311 int LIBUSB_CALL libusb_wait_for_event(libusb_context *ctx, struct timeval *tv);
   1312 
   1313 int LIBUSB_CALL libusb_handle_events_timeout(libusb_context *ctx,
   1314 	struct timeval *tv);
   1315 int LIBUSB_CALL libusb_handle_events_timeout_completed(libusb_context *ctx,
   1316 	struct timeval *tv, int *completed);
   1317 int LIBUSB_CALL libusb_handle_events(libusb_context *ctx);
   1318 int LIBUSB_CALL libusb_handle_events_completed(libusb_context *ctx, int *completed);
   1319 int LIBUSB_CALL libusb_handle_events_locked(libusb_context *ctx,
   1320 	struct timeval *tv);
   1321 int LIBUSB_CALL libusb_pollfds_handle_timeouts(libusb_context *ctx);
   1322 int LIBUSB_CALL libusb_get_next_timeout(libusb_context *ctx,
   1323 	struct timeval *tv);
   1324 
   1325 /** \ingroup poll
   1326  * File descriptor for polling
   1327  */
   1328 struct libusb_pollfd {
   1329 	/** Numeric file descriptor */
   1330 	int fd;
   1331 
   1332 	/** Event flags to poll for from <poll.h>. POLLIN indicates that you
   1333 	 * should monitor this file descriptor for becoming ready to read from,
   1334 	 * and POLLOUT indicates that you should monitor this file descriptor for
   1335 	 * nonblocking write readiness. */
   1336 	short events;
   1337 };
   1338 
   1339 /** \ingroup poll
   1340  * Callback function, invoked when a new file descriptor should be added
   1341  * to the set of file descriptors monitored for events.
   1342  * \param fd the new file descriptor
   1343  * \param events events to monitor for, see \ref libusb_pollfd for a
   1344  * description
   1345  * \param user_data User data pointer specified in
   1346  * libusb_set_pollfd_notifiers() call
   1347  * \see libusb_set_pollfd_notifiers()
   1348  */
   1349 typedef void (LIBUSB_CALL *libusb_pollfd_added_cb)(int fd, short events,
   1350 	void *user_data);
   1351 
   1352 /** \ingroup poll
   1353  * Callback function, invoked when a file descriptor should be removed from
   1354  * the set of file descriptors being monitored for events. After returning
   1355  * from this callback, do not use that file descriptor again.
   1356  * \param fd the file descriptor to stop monitoring
   1357  * \param user_data User data pointer specified in
   1358  * libusb_set_pollfd_notifiers() call
   1359  * \see libusb_set_pollfd_notifiers()
   1360  */
   1361 typedef void (LIBUSB_CALL *libusb_pollfd_removed_cb)(int fd, void *user_data);
   1362 
   1363 const struct libusb_pollfd ** LIBUSB_CALL libusb_get_pollfds(
   1364 	libusb_context *ctx);
   1365 void LIBUSB_CALL libusb_set_pollfd_notifiers(libusb_context *ctx,
   1366 	libusb_pollfd_added_cb added_cb, libusb_pollfd_removed_cb removed_cb,
   1367 	void *user_data);
   1368 
   1369 #ifdef __cplusplus
   1370 }
   1371 #endif
   1372 
   1373 #endif
   1374