2 * Public libusb header file
3 * Copyright © 2001 Johannes Erdfelt <johannes@erdfelt.com>
4 * Copyright © 2007-2008 Daniel Drake <dsd@gentoo.org>
5 * Copyright © 2012 Pete Batard <pete@akeo.ie>
6 * Copyright © 2012 Nathan Hjelm <hjelmn@cs.unm.edu>
7 * For more information, please visit: http://libusb.info
9 * This library is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
14 * This library is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Lesser General Public License for more details.
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with this library; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
28 /* on MS environments, the inline keyword is available in C++ only */
29 #if !defined(__cplusplus)
30 #define inline __inline
32 /* ssize_t is also not available (copy/paste from MinGW) */
33 #ifndef _SSIZE_T_DEFINED
34 #define _SSIZE_T_DEFINED
37 typedef __int64 ssize_t;
41 #endif /* _SSIZE_T_DEFINED */
44 /* stdint.h is not available on older MSVC */
45 #if defined(_MSC_VER) && (_MSC_VER < 1600) && (!defined(_STDINT)) && (!defined(_STDINT_H))
46 typedef unsigned __int8 uint8_t;
47 typedef unsigned __int16 uint16_t;
48 typedef unsigned __int32 uint32_t;
53 #if !defined(_WIN32_WCE)
54 #include <sys/types.h>
57 #if defined(__linux) || defined(__APPLE__) || defined(__CYGWIN__) || defined(__HAIKU__)
64 /* 'interface' might be defined as a macro on Windows, so we need to
65 * undefine it so as not to break the current libusb API, because
66 * libusb_config_descriptor has an 'interface' member
67 * As this can be problematic if you include windows.h after libusb.h
68 * in your sources, we force windows.h to be included first. */
69 #if defined(_WIN32) || defined(__CYGWIN__) || defined(_WIN32_WCE)
71 #if defined(interface)
74 #if !defined(__CYGWIN__)
79 #if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)
80 #define LIBUSB_DEPRECATED_FOR(f) \
81 __attribute__((deprecated("Use " #f " instead")))
83 #define LIBUSB_DEPRECATED_FOR(f)
88 * libusb's Windows calling convention.
90 * Under Windows, the selection of available compilers and configurations
91 * means that, unlike other platforms, there is not <em>one true calling
92 * convention</em> (calling convention: the manner in which parameters are
93 * passed to funcions in the generated assembly code).
95 * Matching the Windows API itself, libusb uses the WINAPI convention (which
96 * translates to the <tt>stdcall</tt> convention) and guarantees that the
97 * library is compiled in this way. The public header file also includes
98 * appropriate annotations so that your own software will use the right
99 * convention, even if another convention is being used by default within
102 * The one consideration that you must apply in your software is to mark
103 * all functions which you use as libusb callbacks with this LIBUSB_CALL
104 * annotation, so that they too get compiled for the correct calling
107 * On non-Windows operating systems, this macro is defined as nothing. This
108 * means that you can apply it to your code without worrying about
109 * cross-platform compatibility.
111 /* LIBUSB_CALL must be defined on both definition and declaration of libusb
112 * functions. You'd think that declaration would be enough, but cygwin will
113 * complain about conflicting types unless both are marked this way.
114 * The placement of this macro is important too; it must appear after the
115 * return type, before the function name. See internal documentation for
118 #if defined(_WIN32) || defined(__CYGWIN__) || defined(_WIN32_WCE)
119 #define LIBUSB_CALL WINAPI
124 /** \def LIBUSB_API_VERSION
126 * libusb's API version.
128 * Since version 1.0.13, to help with feature detection, libusb defines
129 * a LIBUSB_API_VERSION macro that gets increased every time there is a
130 * significant change to the API, such as the introduction of a new call,
131 * the definition of a new macro/enum member, or any other element that
132 * libusb applications may want to detect at compilation time.
134 * The macro is typically used in an application as follows:
136 * #if defined(LIBUSB_API_VERSION) && (LIBUSB_API_VERSION >= 0x01001234)
137 * // Use one of the newer features from the libusb API
141 * Another feature of LIBUSB_API_VERSION is that it can be used to detect
142 * whether you are compiling against the libusb or the libusb library.
144 * Internally, LIBUSB_API_VERSION is defined as follows:
145 * (libusb major << 24) | (libusb minor << 16) | (16 bit incremental)
147 #define LIBUSB_API_VERSION 0x01000103
149 /* The following is kept for compatibility, but will be deprecated in the future */
150 #define LIBUSBX_API_VERSION LIBUSB_API_VERSION
158 * Convert a 16-bit value from host-endian to little-endian format. On
159 * little endian systems, this function does nothing. On big endian systems,
160 * the bytes are swapped.
161 * \param x the host-endian value to convert
162 * \returns the value in little-endian byte order
164 static inline uint16_t libusb_cpu_to_le16(const uint16_t x)
170 _tmp.b8[1] = (uint8_t) (x >> 8);
171 _tmp.b8[0] = (uint8_t) (x & 0xff);
175 /** \def libusb_le16_to_cpu
177 * Convert a 16-bit value from little-endian to host-endian format. On
178 * little endian systems, this function does nothing. On big endian systems,
179 * the bytes are swapped.
180 * \param x the little-endian value to convert
181 * \returns the value in host-endian byte order
183 #define libusb_le16_to_cpu libusb_cpu_to_le16
185 /* standard USB stuff */
188 * Device and/or Interface Class codes */
189 enum libusb_class_code {
190 /** In the context of a \ref libusb_device_descriptor "device descriptor",
191 * this bDeviceClass value indicates that each interface specifies its
192 * own class information and all interfaces operate independently.
194 LIBUSB_CLASS_PER_INTERFACE = 0,
197 LIBUSB_CLASS_AUDIO = 1,
199 /** Communications class */
200 LIBUSB_CLASS_COMM = 2,
202 /** Human Interface Device class */
203 LIBUSB_CLASS_HID = 3,
206 LIBUSB_CLASS_PHYSICAL = 5,
209 LIBUSB_CLASS_PRINTER = 7,
212 LIBUSB_CLASS_PTP = 6, /* legacy name from libusb-0.1 usb.h */
213 LIBUSB_CLASS_IMAGE = 6,
215 /** Mass storage class */
216 LIBUSB_CLASS_MASS_STORAGE = 8,
219 LIBUSB_CLASS_HUB = 9,
222 LIBUSB_CLASS_DATA = 10,
225 LIBUSB_CLASS_SMART_CARD = 0x0b,
227 /** Content Security */
228 LIBUSB_CLASS_CONTENT_SECURITY = 0x0d,
231 LIBUSB_CLASS_VIDEO = 0x0e,
233 /** Personal Healthcare */
234 LIBUSB_CLASS_PERSONAL_HEALTHCARE = 0x0f,
236 /** Diagnostic Device */
237 LIBUSB_CLASS_DIAGNOSTIC_DEVICE = 0xdc,
239 /** Wireless class */
240 LIBUSB_CLASS_WIRELESS = 0xe0,
242 /** Application class */
243 LIBUSB_CLASS_APPLICATION = 0xfe,
245 /** Class is vendor-specific */
246 LIBUSB_CLASS_VENDOR_SPEC = 0xff
250 * Descriptor types as defined by the USB specification. */
251 enum libusb_descriptor_type {
252 /** Device descriptor. See libusb_device_descriptor. */
253 LIBUSB_DT_DEVICE = 0x01,
255 /** Configuration descriptor. See libusb_config_descriptor. */
256 LIBUSB_DT_CONFIG = 0x02,
258 /** String descriptor */
259 LIBUSB_DT_STRING = 0x03,
261 /** Interface descriptor. See libusb_interface_descriptor. */
262 LIBUSB_DT_INTERFACE = 0x04,
264 /** Endpoint descriptor. See libusb_endpoint_descriptor. */
265 LIBUSB_DT_ENDPOINT = 0x05,
267 /** BOS descriptor */
268 LIBUSB_DT_BOS = 0x0f,
270 /** Device Capability descriptor */
271 LIBUSB_DT_DEVICE_CAPABILITY = 0x10,
273 /** HID descriptor */
274 LIBUSB_DT_HID = 0x21,
276 /** HID report descriptor */
277 LIBUSB_DT_REPORT = 0x22,
279 /** Physical descriptor */
280 LIBUSB_DT_PHYSICAL = 0x23,
282 /** Hub descriptor */
283 LIBUSB_DT_HUB = 0x29,
285 /** SuperSpeed Hub descriptor */
286 LIBUSB_DT_SUPERSPEED_HUB = 0x2a,
288 /** SuperSpeed Endpoint Companion descriptor */
289 LIBUSB_DT_SS_ENDPOINT_COMPANION = 0x30
292 /* Descriptor sizes per descriptor type */
293 #define LIBUSB_DT_DEVICE_SIZE 18
294 #define LIBUSB_DT_CONFIG_SIZE 9
295 #define LIBUSB_DT_INTERFACE_SIZE 9
296 #define LIBUSB_DT_ENDPOINT_SIZE 7
297 #define LIBUSB_DT_ENDPOINT_AUDIO_SIZE 9 /* Audio extension */
298 #define LIBUSB_DT_HUB_NONVAR_SIZE 7
299 #define LIBUSB_DT_SS_ENDPOINT_COMPANION_SIZE 6
300 #define LIBUSB_DT_BOS_SIZE 5
301 #define LIBUSB_DT_DEVICE_CAPABILITY_SIZE 3
303 /* BOS descriptor sizes */
304 #define LIBUSB_BT_USB_2_0_EXTENSION_SIZE 7
305 #define LIBUSB_BT_SS_USB_DEVICE_CAPABILITY_SIZE 10
306 #define LIBUSB_BT_CONTAINER_ID_SIZE 20
308 /* We unwrap the BOS => define its max size */
309 #define LIBUSB_DT_BOS_MAX_SIZE ((LIBUSB_DT_BOS_SIZE) +\
310 (LIBUSB_BT_USB_2_0_EXTENSION_SIZE) +\
311 (LIBUSB_BT_SS_USB_DEVICE_CAPABILITY_SIZE) +\
312 (LIBUSB_BT_CONTAINER_ID_SIZE))
314 #define LIBUSB_ENDPOINT_ADDRESS_MASK 0x0f /* in bEndpointAddress */
315 #define LIBUSB_ENDPOINT_DIR_MASK 0x80
318 * Endpoint direction. Values for bit 7 of the
319 * \ref libusb_endpoint_descriptor::bEndpointAddress "endpoint address" scheme.
321 enum libusb_endpoint_direction {
322 /** In: device-to-host */
323 LIBUSB_ENDPOINT_IN = 0x80,
325 /** Out: host-to-device */
326 LIBUSB_ENDPOINT_OUT = 0x00
329 #define LIBUSB_TRANSFER_TYPE_MASK 0x03 /* in bmAttributes */
332 * Endpoint transfer type. Values for bits 0:1 of the
333 * \ref libusb_endpoint_descriptor::bmAttributes "endpoint attributes" field.
335 enum libusb_transfer_type {
336 /** Control endpoint */
337 LIBUSB_TRANSFER_TYPE_CONTROL = 0,
339 /** Isochronous endpoint */
340 LIBUSB_TRANSFER_TYPE_ISOCHRONOUS = 1,
343 LIBUSB_TRANSFER_TYPE_BULK = 2,
345 /** Interrupt endpoint */
346 LIBUSB_TRANSFER_TYPE_INTERRUPT = 3,
348 /** Stream endpoint */
349 LIBUSB_TRANSFER_TYPE_BULK_STREAM = 4,
353 * Standard requests, as defined in table 9-5 of the USB 3.0 specifications */
354 enum libusb_standard_request {
355 /** Request status of the specific recipient */
356 LIBUSB_REQUEST_GET_STATUS = 0x00,
358 /** Clear or disable a specific feature */
359 LIBUSB_REQUEST_CLEAR_FEATURE = 0x01,
361 /* 0x02 is reserved */
363 /** Set or enable a specific feature */
364 LIBUSB_REQUEST_SET_FEATURE = 0x03,
366 /* 0x04 is reserved */
368 /** Set device address for all future accesses */
369 LIBUSB_REQUEST_SET_ADDRESS = 0x05,
371 /** Get the specified descriptor */
372 LIBUSB_REQUEST_GET_DESCRIPTOR = 0x06,
374 /** Used to update existing descriptors or add new descriptors */
375 LIBUSB_REQUEST_SET_DESCRIPTOR = 0x07,
377 /** Get the current device configuration value */
378 LIBUSB_REQUEST_GET_CONFIGURATION = 0x08,
380 /** Set device configuration */
381 LIBUSB_REQUEST_SET_CONFIGURATION = 0x09,
383 /** Return the selected alternate setting for the specified interface */
384 LIBUSB_REQUEST_GET_INTERFACE = 0x0A,
386 /** Select an alternate interface for the specified interface */
387 LIBUSB_REQUEST_SET_INTERFACE = 0x0B,
389 /** Set then report an endpoint's synchronization frame */
390 LIBUSB_REQUEST_SYNCH_FRAME = 0x0C,
392 /** Sets both the U1 and U2 Exit Latency */
393 LIBUSB_REQUEST_SET_SEL = 0x30,
395 /** Delay from the time a host transmits a packet to the time it is
396 * received by the device. */
397 LIBUSB_SET_ISOCH_DELAY = 0x31,
401 * Request type bits of the
402 * \ref libusb_control_setup::bmRequestType "bmRequestType" field in control
404 enum libusb_request_type {
406 LIBUSB_REQUEST_TYPE_STANDARD = (0x00 << 5),
409 LIBUSB_REQUEST_TYPE_CLASS = (0x01 << 5),
412 LIBUSB_REQUEST_TYPE_VENDOR = (0x02 << 5),
415 LIBUSB_REQUEST_TYPE_RESERVED = (0x03 << 5)
419 * Recipient bits of the
420 * \ref libusb_control_setup::bmRequestType "bmRequestType" field in control
421 * transfers. Values 4 through 31 are reserved. */
422 enum libusb_request_recipient {
424 LIBUSB_RECIPIENT_DEVICE = 0x00,
427 LIBUSB_RECIPIENT_INTERFACE = 0x01,
430 LIBUSB_RECIPIENT_ENDPOINT = 0x02,
433 LIBUSB_RECIPIENT_OTHER = 0x03,
436 #define LIBUSB_ISO_SYNC_TYPE_MASK 0x0C
439 * Synchronization type for isochronous endpoints. Values for bits 2:3 of the
440 * \ref libusb_endpoint_descriptor::bmAttributes "bmAttributes" field in
441 * libusb_endpoint_descriptor.
443 enum libusb_iso_sync_type {
444 /** No synchronization */
445 LIBUSB_ISO_SYNC_TYPE_NONE = 0,
448 LIBUSB_ISO_SYNC_TYPE_ASYNC = 1,
451 LIBUSB_ISO_SYNC_TYPE_ADAPTIVE = 2,
454 LIBUSB_ISO_SYNC_TYPE_SYNC = 3
457 #define LIBUSB_ISO_USAGE_TYPE_MASK 0x30
460 * Usage type for isochronous endpoints. Values for bits 4:5 of the
461 * \ref libusb_endpoint_descriptor::bmAttributes "bmAttributes" field in
462 * libusb_endpoint_descriptor.
464 enum libusb_iso_usage_type {
466 LIBUSB_ISO_USAGE_TYPE_DATA = 0,
468 /** Feedback endpoint */
469 LIBUSB_ISO_USAGE_TYPE_FEEDBACK = 1,
471 /** Implicit feedback Data endpoint */
472 LIBUSB_ISO_USAGE_TYPE_IMPLICIT = 2,
476 * A structure representing the standard USB device descriptor. This
477 * descriptor is documented in section 9.6.1 of the USB 3.0 specification.
478 * All multiple-byte fields are represented in host-endian format.
480 struct libusb_device_descriptor {
481 /** Size of this descriptor (in bytes) */
484 /** Descriptor type. Will have value
485 * \ref libusb_descriptor_type::LIBUSB_DT_DEVICE LIBUSB_DT_DEVICE in this
487 uint8_t bDescriptorType;
489 /** USB specification release number in binary-coded decimal. A value of
490 * 0x0200 indicates USB 2.0, 0x0110 indicates USB 1.1, etc. */
493 /** USB-IF class code for the device. See \ref libusb_class_code. */
494 uint8_t bDeviceClass;
496 /** USB-IF subclass code for the device, qualified by the bDeviceClass
498 uint8_t bDeviceSubClass;
500 /** USB-IF protocol code for the device, qualified by the bDeviceClass and
501 * bDeviceSubClass values */
502 uint8_t bDeviceProtocol;
504 /** Maximum packet size for endpoint 0 */
505 uint8_t bMaxPacketSize0;
507 /** USB-IF vendor ID */
510 /** USB-IF product ID */
513 /** Device release number in binary-coded decimal */
516 /** Index of string descriptor describing manufacturer */
517 uint8_t iManufacturer;
519 /** Index of string descriptor describing product */
522 /** Index of string descriptor containing device serial number */
523 uint8_t iSerialNumber;
525 /** Number of possible configurations */
526 uint8_t bNumConfigurations;
530 * A structure representing the standard USB endpoint descriptor. This
531 * descriptor is documented in section 9.6.6 of the USB 3.0 specification.
532 * All multiple-byte fields are represented in host-endian format.
534 struct libusb_endpoint_descriptor {
535 /** Size of this descriptor (in bytes) */
538 /** Descriptor type. Will have value
539 * \ref libusb_descriptor_type::LIBUSB_DT_ENDPOINT LIBUSB_DT_ENDPOINT in
541 uint8_t bDescriptorType;
543 /** The address of the endpoint described by this descriptor. Bits 0:3 are
544 * the endpoint number. Bits 4:6 are reserved. Bit 7 indicates direction,
545 * see \ref libusb_endpoint_direction.
547 uint8_t bEndpointAddress;
549 /** Attributes which apply to the endpoint when it is configured using
550 * the bConfigurationValue. Bits 0:1 determine the transfer type and
551 * correspond to \ref libusb_transfer_type. Bits 2:3 are only used for
552 * isochronous endpoints and correspond to \ref libusb_iso_sync_type.
553 * Bits 4:5 are also only used for isochronous endpoints and correspond to
554 * \ref libusb_iso_usage_type. Bits 6:7 are reserved.
556 uint8_t bmAttributes;
558 /** Maximum packet size this endpoint is capable of sending/receiving. */
559 uint16_t wMaxPacketSize;
561 /** Interval for polling endpoint for data transfers. */
564 /** For audio devices only: the rate at which synchronization feedback
568 /** For audio devices only: the address if the synch endpoint */
569 uint8_t bSynchAddress;
571 /** Extra descriptors. If libusb encounters unknown endpoint descriptors,
572 * it will store them here, should you wish to parse them. */
573 const unsigned char *extra;
575 /** Length of the extra descriptors, in bytes. */
580 * A structure representing the standard USB interface descriptor. This
581 * descriptor is documented in section 9.6.5 of the USB 3.0 specification.
582 * All multiple-byte fields are represented in host-endian format.
584 struct libusb_interface_descriptor {
585 /** Size of this descriptor (in bytes) */
588 /** Descriptor type. Will have value
589 * \ref libusb_descriptor_type::LIBUSB_DT_INTERFACE LIBUSB_DT_INTERFACE
590 * in this context. */
591 uint8_t bDescriptorType;
593 /** Number of this interface */
594 uint8_t bInterfaceNumber;
596 /** Value used to select this alternate setting for this interface */
597 uint8_t bAlternateSetting;
599 /** Number of endpoints used by this interface (excluding the control
601 uint8_t bNumEndpoints;
603 /** USB-IF class code for this interface. See \ref libusb_class_code. */
604 uint8_t bInterfaceClass;
606 /** USB-IF subclass code for this interface, qualified by the
607 * bInterfaceClass value */
608 uint8_t bInterfaceSubClass;
610 /** USB-IF protocol code for this interface, qualified by the
611 * bInterfaceClass and bInterfaceSubClass values */
612 uint8_t bInterfaceProtocol;
614 /** Index of string descriptor describing this interface */
617 /** Array of endpoint descriptors. This length of this array is determined
618 * by the bNumEndpoints field. */
619 const struct libusb_endpoint_descriptor *endpoint;
621 /** Extra descriptors. If libusb encounters unknown interface descriptors,
622 * it will store them here, should you wish to parse them. */
623 const unsigned char *extra;
625 /** Length of the extra descriptors, in bytes. */
630 * A collection of alternate settings for a particular USB interface.
632 struct libusb_interface {
633 /** Array of interface descriptors. The length of this array is determined
634 * by the num_altsetting field. */
635 const struct libusb_interface_descriptor *altsetting;
637 /** The number of alternate settings that belong to this interface */
642 * A structure representing the standard USB configuration descriptor. This
643 * descriptor is documented in section 9.6.3 of the USB 3.0 specification.
644 * All multiple-byte fields are represented in host-endian format.
646 struct libusb_config_descriptor {
647 /** Size of this descriptor (in bytes) */
650 /** Descriptor type. Will have value
651 * \ref libusb_descriptor_type::LIBUSB_DT_CONFIG LIBUSB_DT_CONFIG
652 * in this context. */
653 uint8_t bDescriptorType;
655 /** Total length of data returned for this configuration */
656 uint16_t wTotalLength;
658 /** Number of interfaces supported by this configuration */
659 uint8_t bNumInterfaces;
661 /** Identifier value for this configuration */
662 uint8_t bConfigurationValue;
664 /** Index of string descriptor describing this configuration */
665 uint8_t iConfiguration;
667 /** Configuration characteristics */
668 uint8_t bmAttributes;
670 /** Maximum power consumption of the USB device from this bus in this
671 * configuration when the device is fully opreation. Expressed in units
675 /** Array of interfaces supported by this configuration. The length of
676 * this array is determined by the bNumInterfaces field. */
677 const struct libusb_interface *interface;
679 /** Extra descriptors. If libusb encounters unknown configuration
680 * descriptors, it will store them here, should you wish to parse them. */
681 const unsigned char *extra;
683 /** Length of the extra descriptors, in bytes. */
688 * A structure representing the superspeed endpoint companion
689 * descriptor. This descriptor is documented in section 9.6.7 of
690 * the USB 3.0 specification. All multiple-byte fields are represented in
691 * host-endian format.
693 struct libusb_ss_endpoint_companion_descriptor {
695 /** Size of this descriptor (in bytes) */
698 /** Descriptor type. Will have value
699 * \ref libusb_descriptor_type::LIBUSB_DT_SS_ENDPOINT_COMPANION in
701 uint8_t bDescriptorType;
704 /** The maximum number of packets the endpoint can send or
705 * recieve as part of a burst. */
708 /** In bulk EP: bits 4:0 represents the maximum number of
709 * streams the EP supports. In isochronous EP: bits 1:0
710 * represents the Mult - a zero based value that determines
711 * the maximum number of packets within a service interval */
712 uint8_t bmAttributes;
714 /** The total number of bytes this EP will transfer every
715 * service interval. valid only for periodic EPs. */
716 uint16_t wBytesPerInterval;
720 * A generic representation of a BOS Device Capability descriptor. It is
721 * advised to check bDevCapabilityType and call the matching
722 * libusb_get_*_descriptor function to get a structure fully matching the type.
724 struct libusb_bos_dev_capability_descriptor {
725 /** Size of this descriptor (in bytes) */
727 /** Descriptor type. Will have value
728 * \ref libusb_descriptor_type::LIBUSB_DT_DEVICE_CAPABILITY
729 * LIBUSB_DT_DEVICE_CAPABILITY in this context. */
730 uint8_t bDescriptorType;
731 /** Device Capability type */
732 uint8_t bDevCapabilityType;
733 /** Device Capability data (bLength - 3 bytes) */
734 uint8_t dev_capability_data
735 #if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)
736 [] /* valid C99 code */
738 [0] /* non-standard, but usually working code */
744 * A structure representing the Binary Device Object Store (BOS) descriptor.
745 * This descriptor is documented in section 9.6.2 of the USB 3.0 specification.
746 * All multiple-byte fields are represented in host-endian format.
748 struct libusb_bos_descriptor {
749 /** Size of this descriptor (in bytes) */
752 /** Descriptor type. Will have value
753 * \ref libusb_descriptor_type::LIBUSB_DT_BOS LIBUSB_DT_BOS
754 * in this context. */
755 uint8_t bDescriptorType;
757 /** Length of this descriptor and all of its sub descriptors */
758 uint16_t wTotalLength;
760 /** The number of separate device capability descriptors in
762 uint8_t bNumDeviceCaps;
764 /** bNumDeviceCap Device Capability Descriptors */
765 struct libusb_bos_dev_capability_descriptor *dev_capability
766 #if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)
767 [] /* valid C99 code */
769 [0] /* non-standard, but usually working code */
775 * A structure representing the USB 2.0 Extension descriptor
776 * This descriptor is documented in section 9.6.2.1 of the USB 3.0 specification.
777 * All multiple-byte fields are represented in host-endian format.
779 struct libusb_usb_2_0_extension_descriptor {
780 /** Size of this descriptor (in bytes) */
783 /** Descriptor type. Will have value
784 * \ref libusb_descriptor_type::LIBUSB_DT_DEVICE_CAPABILITY
785 * LIBUSB_DT_DEVICE_CAPABILITY in this context. */
786 uint8_t bDescriptorType;
788 /** Capability type. Will have value
789 * \ref libusb_capability_type::LIBUSB_BT_USB_2_0_EXTENSION
790 * LIBUSB_BT_USB_2_0_EXTENSION in this context. */
791 uint8_t bDevCapabilityType;
793 /** Bitmap encoding of supported device level features.
794 * A value of one in a bit location indicates a feature is
795 * supported; a value of zero indicates it is not supported.
796 * See \ref libusb_usb_2_0_extension_attributes. */
797 uint32_t bmAttributes;
801 * A structure representing the SuperSpeed USB Device Capability descriptor
802 * This descriptor is documented in section 9.6.2.2 of the USB 3.0 specification.
803 * All multiple-byte fields are represented in host-endian format.
805 struct libusb_ss_usb_device_capability_descriptor {
806 /** Size of this descriptor (in bytes) */
809 /** Descriptor type. Will have value
810 * \ref libusb_descriptor_type::LIBUSB_DT_DEVICE_CAPABILITY
811 * LIBUSB_DT_DEVICE_CAPABILITY in this context. */
812 uint8_t bDescriptorType;
814 /** Capability type. Will have value
815 * \ref libusb_capability_type::LIBUSB_BT_SS_USB_DEVICE_CAPABILITY
816 * LIBUSB_BT_SS_USB_DEVICE_CAPABILITY in this context. */
817 uint8_t bDevCapabilityType;
819 /** Bitmap encoding of supported device level features.
820 * A value of one in a bit location indicates a feature is
821 * supported; a value of zero indicates it is not supported.
822 * See \ref libusb_ss_usb_device_capability_attributes. */
823 uint8_t bmAttributes;
825 /** Bitmap encoding of the speed supported by this device when
826 * operating in SuperSpeed mode. See \ref libusb_supported_speed. */
827 uint16_t wSpeedSupported;
829 /** The lowest speed at which all the functionality supported
830 * by the device is available to the user. For example if the
831 * device supports all its functionality when connected at
832 * full speed and above then it sets this value to 1. */
833 uint8_t bFunctionalitySupport;
835 /** U1 Device Exit Latency. */
836 uint8_t bU1DevExitLat;
838 /** U2 Device Exit Latency. */
839 uint16_t bU2DevExitLat;
843 * A structure representing the Container ID descriptor.
844 * This descriptor is documented in section 9.6.2.3 of the USB 3.0 specification.
845 * All multiple-byte fields, except UUIDs, are represented in host-endian format.
847 struct libusb_container_id_descriptor {
848 /** Size of this descriptor (in bytes) */
851 /** Descriptor type. Will have value
852 * \ref libusb_descriptor_type::LIBUSB_DT_DEVICE_CAPABILITY
853 * LIBUSB_DT_DEVICE_CAPABILITY in this context. */
854 uint8_t bDescriptorType;
856 /** Capability type. Will have value
857 * \ref libusb_capability_type::LIBUSB_BT_CONTAINER_ID
858 * LIBUSB_BT_CONTAINER_ID in this context. */
859 uint8_t bDevCapabilityType;
861 /** Reserved field */
865 uint8_t ContainerID[16];
869 * Setup packet for control transfers. */
870 struct libusb_control_setup {
871 /** Request type. Bits 0:4 determine recipient, see
872 * \ref libusb_request_recipient. Bits 5:6 determine type, see
873 * \ref libusb_request_type. Bit 7 determines data transfer direction, see
874 * \ref libusb_endpoint_direction.
876 uint8_t bmRequestType;
878 /** Request. If the type bits of bmRequestType are equal to
879 * \ref libusb_request_type::LIBUSB_REQUEST_TYPE_STANDARD
880 * "LIBUSB_REQUEST_TYPE_STANDARD" then this field refers to
881 * \ref libusb_standard_request. For other cases, use of this field is
882 * application-specific. */
885 /** Value. Varies according to request */
888 /** Index. Varies according to request, typically used to pass an index
892 /** Number of bytes to transfer */
896 #define LIBUSB_CONTROL_SETUP_SIZE (sizeof(struct libusb_control_setup))
900 struct libusb_context;
901 struct libusb_device;
902 struct libusb_device_handle;
903 struct libusb_hotplug_callback;
906 * Structure providing the version of the libusb runtime
908 struct libusb_version {
909 /** Library major version. */
910 const uint16_t major;
912 /** Library minor version. */
913 const uint16_t minor;
915 /** Library micro version. */
916 const uint16_t micro;
918 /** Library nano version. */
921 /** Library release candidate suffix string, e.g. "-rc4". */
924 /** For ABI compatibility only. */
925 const char* describe;
929 * Structure representing a libusb session. The concept of individual libusb
930 * sessions allows for your program to use two libraries (or dynamically
931 * load two modules) which both independently use libusb. This will prevent
932 * interference between the individual libusb users - for example
933 * libusb_set_debug() will not affect the other user of the library, and
934 * libusb_exit() will not destroy resources that the other user is still
937 * Sessions are created by libusb_init() and destroyed through libusb_exit().
938 * If your application is guaranteed to only ever include a single libusb
939 * user (i.e. you), you do not have to worry about contexts: pass NULL in
940 * every function call where a context is required. The default context
943 * For more information, see \ref contexts.
945 typedef struct libusb_context libusb_context;
948 * Structure representing a USB device detected on the system. This is an
949 * opaque type for which you are only ever provided with a pointer, usually
950 * originating from libusb_get_device_list().
952 * Certain operations can be performed on a device, but in order to do any
953 * I/O you will have to first obtain a device handle using libusb_open().
955 * Devices are reference counted with libusb_ref_device() and
956 * libusb_unref_device(), and are freed when the reference count reaches 0.
957 * New devices presented by libusb_get_device_list() have a reference count of
958 * 1, and libusb_free_device_list() can optionally decrease the reference count
959 * on all devices in the list. libusb_open() adds another reference which is
960 * later destroyed by libusb_close().
962 typedef struct libusb_device libusb_device;
966 * Structure representing a handle on a USB device. This is an opaque type for
967 * which you are only ever provided with a pointer, usually originating from
970 * A device handle is used to perform I/O and other operations. When finished
971 * with a device handle, you should call libusb_close().
973 typedef struct libusb_device_handle libusb_device_handle;
976 * Speed codes. Indicates the speed at which the device is operating.
979 /** The OS doesn't report or know the device speed. */
980 LIBUSB_SPEED_UNKNOWN = 0,
982 /** The device is operating at low speed (1.5MBit/s). */
983 LIBUSB_SPEED_LOW = 1,
985 /** The device is operating at full speed (12MBit/s). */
986 LIBUSB_SPEED_FULL = 2,
988 /** The device is operating at high speed (480MBit/s). */
989 LIBUSB_SPEED_HIGH = 3,
991 /** The device is operating at super speed (5000MBit/s). */
992 LIBUSB_SPEED_SUPER = 4,
996 * Supported speeds (wSpeedSupported) bitfield. Indicates what
997 * speeds the device supports.
999 enum libusb_supported_speed {
1000 /** Low speed operation supported (1.5MBit/s). */
1001 LIBUSB_LOW_SPEED_OPERATION = 1,
1003 /** Full speed operation supported (12MBit/s). */
1004 LIBUSB_FULL_SPEED_OPERATION = 2,
1006 /** High speed operation supported (480MBit/s). */
1007 LIBUSB_HIGH_SPEED_OPERATION = 4,
1009 /** Superspeed operation supported (5000MBit/s). */
1010 LIBUSB_SUPER_SPEED_OPERATION = 8,
1014 * Masks for the bits of the
1015 * \ref libusb_usb_2_0_extension_descriptor::bmAttributes "bmAttributes" field
1016 * of the USB 2.0 Extension descriptor.
1018 enum libusb_usb_2_0_extension_attributes {
1019 /** Supports Link Power Management (LPM) */
1020 LIBUSB_BM_LPM_SUPPORT = 2,
1024 * Masks for the bits of the
1025 * \ref libusb_ss_usb_device_capability_descriptor::bmAttributes "bmAttributes" field
1026 * field of the SuperSpeed USB Device Capability descriptor.
1028 enum libusb_ss_usb_device_capability_attributes {
1029 /** Supports Latency Tolerance Messages (LTM) */
1030 LIBUSB_BM_LTM_SUPPORT = 2,
1034 * USB capability types
1036 enum libusb_bos_type {
1037 /** Wireless USB device capability */
1038 LIBUSB_BT_WIRELESS_USB_DEVICE_CAPABILITY = 1,
1040 /** USB 2.0 extensions */
1041 LIBUSB_BT_USB_2_0_EXTENSION = 2,
1043 /** SuperSpeed USB device capability */
1044 LIBUSB_BT_SS_USB_DEVICE_CAPABILITY = 3,
1046 /** Container ID type */
1047 LIBUSB_BT_CONTAINER_ID = 4,
1051 * Error codes. Most libusb functions return 0 on success or one of these
1053 * You can call libusb_error_name() to retrieve a string representation of an
1054 * error code or libusb_strerror() to get an end-user suitable description of
1058 /** Success (no error) */
1061 /** Input/output error */
1062 LIBUSB_ERROR_IO = -1,
1064 /** Invalid parameter */
1065 LIBUSB_ERROR_INVALID_PARAM = -2,
1067 /** Access denied (insufficient permissions) */
1068 LIBUSB_ERROR_ACCESS = -3,
1070 /** No such device (it may have been disconnected) */
1071 LIBUSB_ERROR_NO_DEVICE = -4,
1073 /** Entity not found */
1074 LIBUSB_ERROR_NOT_FOUND = -5,
1076 /** Resource busy */
1077 LIBUSB_ERROR_BUSY = -6,
1079 /** Operation timed out */
1080 LIBUSB_ERROR_TIMEOUT = -7,
1083 LIBUSB_ERROR_OVERFLOW = -8,
1086 LIBUSB_ERROR_PIPE = -9,
1088 /** System call interrupted (perhaps due to signal) */
1089 LIBUSB_ERROR_INTERRUPTED = -10,
1091 /** Insufficient memory */
1092 LIBUSB_ERROR_NO_MEM = -11,
1094 /** Operation not supported or unimplemented on this platform */
1095 LIBUSB_ERROR_NOT_SUPPORTED = -12,
1097 /* NB: Remember to update LIBUSB_ERROR_COUNT below as well as the
1098 message strings in strerror.c when adding new error codes here. */
1101 LIBUSB_ERROR_OTHER = -99,
1104 /* Total number of error codes in enum libusb_error */
1105 #define LIBUSB_ERROR_COUNT 14
1107 /** \ingroup asyncio
1108 * Transfer status codes */
1109 enum libusb_transfer_status {
1110 /** Transfer completed without error. Note that this does not indicate
1111 * that the entire amount of requested data was transferred. */
1112 LIBUSB_TRANSFER_COMPLETED,
1114 /** Transfer failed */
1115 LIBUSB_TRANSFER_ERROR,
1117 /** Transfer timed out */
1118 LIBUSB_TRANSFER_TIMED_OUT,
1120 /** Transfer was cancelled */
1121 LIBUSB_TRANSFER_CANCELLED,
1123 /** For bulk/interrupt endpoints: halt condition detected (endpoint
1124 * stalled). For control endpoints: control request not supported. */
1125 LIBUSB_TRANSFER_STALL,
1127 /** Device was disconnected */
1128 LIBUSB_TRANSFER_NO_DEVICE,
1130 /** Device sent more data than requested */
1131 LIBUSB_TRANSFER_OVERFLOW,
1133 /* NB! Remember to update libusb_error_name()
1134 when adding new status codes here. */
1137 /** \ingroup asyncio
1138 * libusb_transfer.flags values */
1139 enum libusb_transfer_flags {
1140 /** Report short frames as errors */
1141 LIBUSB_TRANSFER_SHORT_NOT_OK = 1<<0,
1143 /** Automatically free() transfer buffer during libusb_free_transfer() */
1144 LIBUSB_TRANSFER_FREE_BUFFER = 1<<1,
1146 /** Automatically call libusb_free_transfer() after callback returns.
1147 * If this flag is set, it is illegal to call libusb_free_transfer()
1148 * from your transfer callback, as this will result in a double-free
1149 * when this flag is acted upon. */
1150 LIBUSB_TRANSFER_FREE_TRANSFER = 1<<2,
1152 /** Terminate transfers that are a multiple of the endpoint's
1153 * wMaxPacketSize with an extra zero length packet. This is useful
1154 * when a device protocol mandates that each logical request is
1155 * terminated by an incomplete packet (i.e. the logical requests are
1156 * not separated by other means).
1158 * This flag only affects host-to-device transfers to bulk and interrupt
1159 * endpoints. In other situations, it is ignored.
1161 * This flag only affects transfers with a length that is a multiple of
1162 * the endpoint's wMaxPacketSize. On transfers of other lengths, this
1163 * flag has no effect. Therefore, if you are working with a device that
1164 * needs a ZLP whenever the end of the logical request falls on a packet
1165 * boundary, then it is sensible to set this flag on <em>every</em>
1166 * transfer (you do not have to worry about only setting it on transfers
1167 * that end on the boundary).
1169 * This flag is currently only supported on Linux.
1170 * On other systems, libusb_submit_transfer() will return
1171 * LIBUSB_ERROR_NOT_SUPPORTED for every transfer where this flag is set.
1173 * Available since libusb-1.0.9.
1175 LIBUSB_TRANSFER_ADD_ZERO_PACKET = 1 << 3,
1178 /** \ingroup asyncio
1179 * Isochronous packet descriptor. */
1180 struct libusb_iso_packet_descriptor {
1181 /** Length of data to request in this packet */
1182 unsigned int length;
1184 /** Amount of data that was actually transferred */
1185 unsigned int actual_length;
1187 /** Status code for this packet */
1188 enum libusb_transfer_status status;
1191 struct libusb_transfer;
1193 /** \ingroup asyncio
1194 * Asynchronous transfer callback function type. When submitting asynchronous
1195 * transfers, you pass a pointer to a callback function of this type via the
1196 * \ref libusb_transfer::callback "callback" member of the libusb_transfer
1197 * structure. libusb will call this function later, when the transfer has
1198 * completed or failed. See \ref asyncio for more information.
1199 * \param transfer The libusb_transfer struct the callback function is being
1202 typedef void (LIBUSB_CALL *libusb_transfer_cb_fn)(struct libusb_transfer *transfer);
1204 /** \ingroup asyncio
1205 * The generic USB transfer structure. The user populates this structure and
1206 * then submits it in order to request a transfer. After the transfer has
1207 * completed, the library populates the transfer with the results and passes
1208 * it back to the user.
1210 struct libusb_transfer {
1211 /** Handle of the device that this transfer will be submitted to */
1212 libusb_device_handle *dev_handle;
1214 /** A bitwise OR combination of \ref libusb_transfer_flags. */
1217 /** Address of the endpoint where this transfer will be sent. */
1218 unsigned char endpoint;
1220 /** Type of the endpoint from \ref libusb_transfer_type */
1223 /** Timeout for this transfer in millseconds. A value of 0 indicates no
1225 unsigned int timeout;
1227 /** The status of the transfer. Read-only, and only for use within
1228 * transfer callback function.
1230 * If this is an isochronous transfer, this field may read COMPLETED even
1231 * if there were errors in the frames. Use the
1232 * \ref libusb_iso_packet_descriptor::status "status" field in each packet
1233 * to determine if errors occurred. */
1234 enum libusb_transfer_status status;
1236 /** Length of the data buffer */
1239 /** Actual length of data that was transferred. Read-only, and only for
1240 * use within transfer callback function. Not valid for isochronous
1241 * endpoint transfers. */
1244 /** Callback function. This will be invoked when the transfer completes,
1245 * fails, or is cancelled. */
1246 libusb_transfer_cb_fn callback;
1248 /** User context data to pass to the callback function. */
1252 unsigned char *buffer;
1254 /** Number of isochronous packets. Only used for I/O with isochronous
1256 int num_iso_packets;
1258 /** Isochronous packet descriptors, for isochronous transfers only. */
1259 struct libusb_iso_packet_descriptor iso_packet_desc
1260 #if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)
1261 [] /* valid C99 code */
1263 [0] /* non-standard, but usually working code */
1269 * Capabilities supported by an instance of libusb on the current running
1270 * platform. Test if the loaded library supports a given capability by calling
1271 * \ref libusb_has_capability().
1273 enum libusb_capability {
1274 /** The libusb_has_capability() API is available. */
1275 LIBUSB_CAP_HAS_CAPABILITY = 0x0000,
1276 /** Hotplug support is available on this platform. */
1277 LIBUSB_CAP_HAS_HOTPLUG = 0x0001,
1278 /** The library can access HID devices without requiring user intervention.
1279 * Note that before being able to actually access an HID device, you may
1280 * still have to call additional libusb functions such as
1281 * \ref libusb_detach_kernel_driver(). */
1282 LIBUSB_CAP_HAS_HID_ACCESS = 0x0100,
1283 /** The library supports detaching of the default USB driver, using
1284 * \ref libusb_detach_kernel_driver(), if one is set by the OS kernel */
1285 LIBUSB_CAP_SUPPORTS_DETACH_KERNEL_DRIVER = 0x0101
1289 * Log message levels.
1290 * - LIBUSB_LOG_LEVEL_NONE (0) : no messages ever printed by the library (default)
1291 * - LIBUSB_LOG_LEVEL_ERROR (1) : error messages are printed to stderr
1292 * - LIBUSB_LOG_LEVEL_WARNING (2) : warning and error messages are printed to stderr
1293 * - LIBUSB_LOG_LEVEL_INFO (3) : informational messages are printed to stdout, warning
1294 * and error messages are printed to stderr
1295 * - LIBUSB_LOG_LEVEL_DEBUG (4) : debug and informational messages are printed to stdout,
1296 * warnings and errors to stderr
1298 enum libusb_log_level {
1299 LIBUSB_LOG_LEVEL_NONE = 0,
1300 LIBUSB_LOG_LEVEL_ERROR,
1301 LIBUSB_LOG_LEVEL_WARNING,
1302 LIBUSB_LOG_LEVEL_INFO,
1303 LIBUSB_LOG_LEVEL_DEBUG,
1306 int LIBUSB_CALL libusb_init(libusb_context **ctx);
1307 void LIBUSB_CALL libusb_exit(libusb_context *ctx);
1308 void LIBUSB_CALL libusb_set_debug(libusb_context *ctx, int level);
1309 const struct libusb_version * LIBUSB_CALL libusb_get_version(void);
1310 int LIBUSB_CALL libusb_has_capability(uint32_t capability);
1311 const char * LIBUSB_CALL libusb_error_name(int errcode);
1312 int LIBUSB_CALL libusb_setlocale(const char *locale);
1313 const char * LIBUSB_CALL libusb_strerror(enum libusb_error errcode);
1315 ssize_t LIBUSB_CALL libusb_get_device_list(libusb_context *ctx,
1316 libusb_device ***list);
1317 void LIBUSB_CALL libusb_free_device_list(libusb_device **list,
1319 libusb_device * LIBUSB_CALL libusb_ref_device(libusb_device *dev);
1320 void LIBUSB_CALL libusb_unref_device(libusb_device *dev);
1322 int LIBUSB_CALL libusb_get_configuration(libusb_device_handle *dev,
1324 int LIBUSB_CALL libusb_get_device_descriptor(libusb_device *dev,
1325 struct libusb_device_descriptor *desc);
1326 int LIBUSB_CALL libusb_get_active_config_descriptor(libusb_device *dev,
1327 struct libusb_config_descriptor **config);
1328 int LIBUSB_CALL libusb_get_config_descriptor(libusb_device *dev,
1329 uint8_t config_index, struct libusb_config_descriptor **config);
1330 int LIBUSB_CALL libusb_get_config_descriptor_by_value(libusb_device *dev,
1331 uint8_t bConfigurationValue, struct libusb_config_descriptor **config);
1332 void LIBUSB_CALL libusb_free_config_descriptor(
1333 struct libusb_config_descriptor *config);
1334 int LIBUSB_CALL libusb_get_ss_endpoint_companion_descriptor(
1335 struct libusb_context *ctx,
1336 const struct libusb_endpoint_descriptor *endpoint,
1337 struct libusb_ss_endpoint_companion_descriptor **ep_comp);
1338 void LIBUSB_CALL libusb_free_ss_endpoint_companion_descriptor(
1339 struct libusb_ss_endpoint_companion_descriptor *ep_comp);
1340 int LIBUSB_CALL libusb_get_bos_descriptor(libusb_device_handle *handle,
1341 struct libusb_bos_descriptor **bos);
1342 void LIBUSB_CALL libusb_free_bos_descriptor(struct libusb_bos_descriptor *bos);
1343 int LIBUSB_CALL libusb_get_usb_2_0_extension_descriptor(
1344 struct libusb_context *ctx,
1345 struct libusb_bos_dev_capability_descriptor *dev_cap,
1346 struct libusb_usb_2_0_extension_descriptor **usb_2_0_extension);
1347 void LIBUSB_CALL libusb_free_usb_2_0_extension_descriptor(
1348 struct libusb_usb_2_0_extension_descriptor *usb_2_0_extension);
1349 int LIBUSB_CALL libusb_get_ss_usb_device_capability_descriptor(
1350 struct libusb_context *ctx,
1351 struct libusb_bos_dev_capability_descriptor *dev_cap,
1352 struct libusb_ss_usb_device_capability_descriptor **ss_usb_device_cap);
1353 void LIBUSB_CALL libusb_free_ss_usb_device_capability_descriptor(
1354 struct libusb_ss_usb_device_capability_descriptor *ss_usb_device_cap);
1355 int LIBUSB_CALL libusb_get_container_id_descriptor(struct libusb_context *ctx,
1356 struct libusb_bos_dev_capability_descriptor *dev_cap,
1357 struct libusb_container_id_descriptor **container_id);
1358 void LIBUSB_CALL libusb_free_container_id_descriptor(
1359 struct libusb_container_id_descriptor *container_id);
1360 uint8_t LIBUSB_CALL libusb_get_bus_number(libusb_device *dev);
1361 uint8_t LIBUSB_CALL libusb_get_port_number(libusb_device *dev);
1362 int LIBUSB_CALL libusb_get_port_numbers(libusb_device *dev, uint8_t* port_numbers, int port_numbers_len);
1363 LIBUSB_DEPRECATED_FOR(libusb_get_port_numbers)
1364 int LIBUSB_CALL libusb_get_port_path(libusb_context *ctx, libusb_device *dev, uint8_t* path, uint8_t path_length);
1365 libusb_device * LIBUSB_CALL libusb_get_parent(libusb_device *dev);
1366 uint8_t LIBUSB_CALL libusb_get_device_address(libusb_device *dev);
1367 int LIBUSB_CALL libusb_get_device_speed(libusb_device *dev);
1368 int LIBUSB_CALL libusb_get_max_packet_size(libusb_device *dev,
1369 unsigned char endpoint);
1370 int LIBUSB_CALL libusb_get_max_iso_packet_size(libusb_device *dev,
1371 unsigned char endpoint);
1373 int LIBUSB_CALL libusb_open(libusb_device *dev, libusb_device_handle **handle);
1374 void LIBUSB_CALL libusb_close(libusb_device_handle *dev_handle);
1375 libusb_device * LIBUSB_CALL libusb_get_device(libusb_device_handle *dev_handle);
1377 int LIBUSB_CALL libusb_set_configuration(libusb_device_handle *dev,
1379 int LIBUSB_CALL libusb_claim_interface(libusb_device_handle *dev,
1380 int interface_number);
1381 int LIBUSB_CALL libusb_release_interface(libusb_device_handle *dev,
1382 int interface_number);
1384 libusb_device_handle * LIBUSB_CALL libusb_open_device_with_vid_pid(
1385 libusb_context *ctx, uint16_t vendor_id, uint16_t product_id);
1387 int LIBUSB_CALL libusb_set_interface_alt_setting(libusb_device_handle *dev,
1388 int interface_number, int alternate_setting);
1389 int LIBUSB_CALL libusb_clear_halt(libusb_device_handle *dev,
1390 unsigned char endpoint);
1391 int LIBUSB_CALL libusb_reset_device(libusb_device_handle *dev);
1393 int LIBUSB_CALL libusb_alloc_streams(libusb_device_handle *dev,
1394 uint32_t num_streams, unsigned char *endpoints, int num_endpoints);
1395 int LIBUSB_CALL libusb_free_streams(libusb_device_handle *dev,
1396 unsigned char *endpoints, int num_endpoints);
1398 int LIBUSB_CALL libusb_kernel_driver_active(libusb_device_handle *dev,
1399 int interface_number);
1400 int LIBUSB_CALL libusb_detach_kernel_driver(libusb_device_handle *dev,
1401 int interface_number);
1402 int LIBUSB_CALL libusb_attach_kernel_driver(libusb_device_handle *dev,
1403 int interface_number);
1404 int LIBUSB_CALL libusb_set_auto_detach_kernel_driver(
1405 libusb_device_handle *dev, int enable);
1409 /** \ingroup asyncio
1410 * Get the data section of a control transfer. This convenience function is here
1411 * to remind you that the data does not start until 8 bytes into the actual
1412 * buffer, as the setup packet comes first.
1414 * Calling this function only makes sense from a transfer callback function,
1415 * or situations where you have already allocated a suitably sized buffer at
1418 * \param transfer a transfer
1419 * \returns pointer to the first byte of the data section
1421 static inline unsigned char *libusb_control_transfer_get_data(
1422 struct libusb_transfer *transfer)
1424 return transfer->buffer + LIBUSB_CONTROL_SETUP_SIZE;
1427 /** \ingroup asyncio
1428 * Get the control setup packet of a control transfer. This convenience
1429 * function is here to remind you that the control setup occupies the first
1430 * 8 bytes of the transfer data buffer.
1432 * Calling this function only makes sense from a transfer callback function,
1433 * or situations where you have already allocated a suitably sized buffer at
1436 * \param transfer a transfer
1437 * \returns a casted pointer to the start of the transfer data buffer
1439 static inline struct libusb_control_setup *libusb_control_transfer_get_setup(
1440 struct libusb_transfer *transfer)
1442 return (struct libusb_control_setup *)(void *) transfer->buffer;
1445 /** \ingroup asyncio
1446 * Helper function to populate the setup packet (first 8 bytes of the data
1447 * buffer) for a control transfer. The wIndex, wValue and wLength values should
1448 * be given in host-endian byte order.
1450 * \param buffer buffer to output the setup packet into
1451 * This pointer must be aligned to at least 2 bytes boundary.
1452 * \param bmRequestType see the
1453 * \ref libusb_control_setup::bmRequestType "bmRequestType" field of
1454 * \ref libusb_control_setup
1455 * \param bRequest see the
1456 * \ref libusb_control_setup::bRequest "bRequest" field of
1457 * \ref libusb_control_setup
1458 * \param wValue see the
1459 * \ref libusb_control_setup::wValue "wValue" field of
1460 * \ref libusb_control_setup
1461 * \param wIndex see the
1462 * \ref libusb_control_setup::wIndex "wIndex" field of
1463 * \ref libusb_control_setup
1464 * \param wLength see the
1465 * \ref libusb_control_setup::wLength "wLength" field of
1466 * \ref libusb_control_setup
1468 static inline void libusb_fill_control_setup(unsigned char *buffer,
1469 uint8_t bmRequestType, uint8_t bRequest, uint16_t wValue, uint16_t wIndex,
1472 struct libusb_control_setup *setup = (struct libusb_control_setup *)(void *) buffer;
1473 setup->bmRequestType = bmRequestType;
1474 setup->bRequest = bRequest;
1475 setup->wValue = libusb_cpu_to_le16(wValue);
1476 setup->wIndex = libusb_cpu_to_le16(wIndex);
1477 setup->wLength = libusb_cpu_to_le16(wLength);
1480 struct libusb_transfer * LIBUSB_CALL libusb_alloc_transfer(int iso_packets);
1481 int LIBUSB_CALL libusb_submit_transfer(struct libusb_transfer *transfer);
1482 int LIBUSB_CALL libusb_cancel_transfer(struct libusb_transfer *transfer);
1483 void LIBUSB_CALL libusb_free_transfer(struct libusb_transfer *transfer);
1484 void LIBUSB_CALL libusb_transfer_set_stream_id(
1485 struct libusb_transfer *transfer, uint32_t stream_id);
1486 uint32_t LIBUSB_CALL libusb_transfer_get_stream_id(
1487 struct libusb_transfer *transfer);
1489 /** \ingroup asyncio
1490 * Helper function to populate the required \ref libusb_transfer fields
1491 * for a control transfer.
1493 * If you pass a transfer buffer to this function, the first 8 bytes will
1494 * be interpreted as a control setup packet, and the wLength field will be
1495 * used to automatically populate the \ref libusb_transfer::length "length"
1496 * field of the transfer. Therefore the recommended approach is:
1497 * -# Allocate a suitably sized data buffer (including space for control setup)
1498 * -# Call libusb_fill_control_setup()
1499 * -# If this is a host-to-device transfer with a data stage, put the data
1500 * in place after the setup packet
1501 * -# Call this function
1502 * -# Call libusb_submit_transfer()
1504 * It is also legal to pass a NULL buffer to this function, in which case this
1505 * function will not attempt to populate the length field. Remember that you
1506 * must then populate the buffer and length fields later.
1508 * \param transfer the transfer to populate
1509 * \param dev_handle handle of the device that will handle the transfer
1510 * \param buffer data buffer. If provided, this function will interpret the
1511 * first 8 bytes as a setup packet and infer the transfer length from that.
1512 * This pointer must be aligned to at least 2 bytes boundary.
1513 * \param callback callback function to be invoked on transfer completion
1514 * \param user_data user data to pass to callback function
1515 * \param timeout timeout for the transfer in milliseconds
1517 static inline void libusb_fill_control_transfer(
1518 struct libusb_transfer *transfer, libusb_device_handle *dev_handle,
1519 unsigned char *buffer, libusb_transfer_cb_fn callback, void *user_data,
1520 unsigned int timeout)
1522 struct libusb_control_setup *setup = (struct libusb_control_setup *)(void *) buffer;
1523 transfer->dev_handle = dev_handle;
1524 transfer->endpoint = 0;
1525 transfer->type = LIBUSB_TRANSFER_TYPE_CONTROL;
1526 transfer->timeout = timeout;
1527 transfer->buffer = buffer;
1529 transfer->length = (int) (LIBUSB_CONTROL_SETUP_SIZE
1530 + libusb_le16_to_cpu(setup->wLength));
1531 transfer->user_data = user_data;
1532 transfer->callback = callback;
1535 /** \ingroup asyncio
1536 * Helper function to populate the required \ref libusb_transfer fields
1537 * for a bulk transfer.
1539 * \param transfer the transfer to populate
1540 * \param dev_handle handle of the device that will handle the transfer
1541 * \param endpoint address of the endpoint where this transfer will be sent
1542 * \param buffer data buffer
1543 * \param length length of data buffer
1544 * \param callback callback function to be invoked on transfer completion
1545 * \param user_data user data to pass to callback function
1546 * \param timeout timeout for the transfer in milliseconds
1548 static inline void libusb_fill_bulk_transfer(struct libusb_transfer *transfer,
1549 libusb_device_handle *dev_handle, unsigned char endpoint,
1550 unsigned char *buffer, int length, libusb_transfer_cb_fn callback,
1551 void *user_data, unsigned int timeout)
1553 transfer->dev_handle = dev_handle;
1554 transfer->endpoint = endpoint;
1555 transfer->type = LIBUSB_TRANSFER_TYPE_BULK;
1556 transfer->timeout = timeout;
1557 transfer->buffer = buffer;
1558 transfer->length = length;
1559 transfer->user_data = user_data;
1560 transfer->callback = callback;
1563 /** \ingroup asyncio
1564 * Helper function to populate the required \ref libusb_transfer fields
1565 * for a bulk transfer using bulk streams.
1567 * Since version 1.0.19, \ref LIBUSB_API_VERSION >= 0x01000103
1569 * \param transfer the transfer to populate
1570 * \param dev_handle handle of the device that will handle the transfer
1571 * \param endpoint address of the endpoint where this transfer will be sent
1572 * \param stream_id bulk stream id for this transfer
1573 * \param buffer data buffer
1574 * \param length length of data buffer
1575 * \param callback callback function to be invoked on transfer completion
1576 * \param user_data user data to pass to callback function
1577 * \param timeout timeout for the transfer in milliseconds
1579 static inline void libusb_fill_bulk_stream_transfer(
1580 struct libusb_transfer *transfer, libusb_device_handle *dev_handle,
1581 unsigned char endpoint, uint32_t stream_id,
1582 unsigned char *buffer, int length, libusb_transfer_cb_fn callback,
1583 void *user_data, unsigned int timeout)
1585 libusb_fill_bulk_transfer(transfer, dev_handle, endpoint, buffer,
1586 length, callback, user_data, timeout);
1587 transfer->type = LIBUSB_TRANSFER_TYPE_BULK_STREAM;
1588 libusb_transfer_set_stream_id(transfer, stream_id);
1591 /** \ingroup asyncio
1592 * Helper function to populate the required \ref libusb_transfer fields
1593 * for an interrupt transfer.
1595 * \param transfer the transfer to populate
1596 * \param dev_handle handle of the device that will handle the transfer
1597 * \param endpoint address of the endpoint where this transfer will be sent
1598 * \param buffer data buffer
1599 * \param length length of data buffer
1600 * \param callback callback function to be invoked on transfer completion
1601 * \param user_data user data to pass to callback function
1602 * \param timeout timeout for the transfer in milliseconds
1604 static inline void libusb_fill_interrupt_transfer(
1605 struct libusb_transfer *transfer, libusb_device_handle *dev_handle,
1606 unsigned char endpoint, unsigned char *buffer, int length,
1607 libusb_transfer_cb_fn callback, void *user_data, unsigned int timeout)
1609 transfer->dev_handle = dev_handle;
1610 transfer->endpoint = endpoint;
1611 transfer->type = LIBUSB_TRANSFER_TYPE_INTERRUPT;
1612 transfer->timeout = timeout;
1613 transfer->buffer = buffer;
1614 transfer->length = length;
1615 transfer->user_data = user_data;
1616 transfer->callback = callback;
1619 /** \ingroup asyncio
1620 * Helper function to populate the required \ref libusb_transfer fields
1621 * for an isochronous transfer.
1623 * \param transfer the transfer to populate
1624 * \param dev_handle handle of the device that will handle the transfer
1625 * \param endpoint address of the endpoint where this transfer will be sent
1626 * \param buffer data buffer
1627 * \param length length of data buffer
1628 * \param num_iso_packets the number of isochronous packets
1629 * \param callback callback function to be invoked on transfer completion
1630 * \param user_data user data to pass to callback function
1631 * \param timeout timeout for the transfer in milliseconds
1633 static inline void libusb_fill_iso_transfer(struct libusb_transfer *transfer,
1634 libusb_device_handle *dev_handle, unsigned char endpoint,
1635 unsigned char *buffer, int length, int num_iso_packets,
1636 libusb_transfer_cb_fn callback, void *user_data, unsigned int timeout)
1638 transfer->dev_handle = dev_handle;
1639 transfer->endpoint = endpoint;
1640 transfer->type = LIBUSB_TRANSFER_TYPE_ISOCHRONOUS;
1641 transfer->timeout = timeout;
1642 transfer->buffer = buffer;
1643 transfer->length = length;
1644 transfer->num_iso_packets = num_iso_packets;
1645 transfer->user_data = user_data;
1646 transfer->callback = callback;
1649 /** \ingroup asyncio
1650 * Convenience function to set the length of all packets in an isochronous
1651 * transfer, based on the num_iso_packets field in the transfer structure.
1653 * \param transfer a transfer
1654 * \param length the length to set in each isochronous packet descriptor
1655 * \see libusb_get_max_packet_size()
1657 static inline void libusb_set_iso_packet_lengths(
1658 struct libusb_transfer *transfer, unsigned int length)
1661 for (i = 0; i < transfer->num_iso_packets; i++)
1662 transfer->iso_packet_desc[i].length = length;
1665 /** \ingroup asyncio
1666 * Convenience function to locate the position of an isochronous packet
1667 * within the buffer of an isochronous transfer.
1669 * This is a thorough function which loops through all preceding packets,
1670 * accumulating their lengths to find the position of the specified packet.
1671 * Typically you will assign equal lengths to each packet in the transfer,
1672 * and hence the above method is sub-optimal. You may wish to use
1673 * libusb_get_iso_packet_buffer_simple() instead.
1675 * \param transfer a transfer
1676 * \param packet the packet to return the address of
1677 * \returns the base address of the packet buffer inside the transfer buffer,
1678 * or NULL if the packet does not exist.
1679 * \see libusb_get_iso_packet_buffer_simple()
1681 static inline unsigned char *libusb_get_iso_packet_buffer(
1682 struct libusb_transfer *transfer, unsigned int packet)
1688 /* oops..slight bug in the API. packet is an unsigned int, but we use
1689 * signed integers almost everywhere else. range-check and convert to
1690 * signed to avoid compiler warnings. FIXME for libusb-2. */
1691 if (packet > INT_MAX)
1693 _packet = (int) packet;
1695 if (_packet >= transfer->num_iso_packets)
1698 for (i = 0; i < _packet; i++)
1699 offset += transfer->iso_packet_desc[i].length;
1701 return transfer->buffer + offset;
1704 /** \ingroup asyncio
1705 * Convenience function to locate the position of an isochronous packet
1706 * within the buffer of an isochronous transfer, for transfers where each
1707 * packet is of identical size.
1709 * This function relies on the assumption that every packet within the transfer
1710 * is of identical size to the first packet. Calculating the location of
1711 * the packet buffer is then just a simple calculation:
1712 * <tt>buffer + (packet_size * packet)</tt>
1714 * Do not use this function on transfers other than those that have identical
1715 * packet lengths for each packet.
1717 * \param transfer a transfer
1718 * \param packet the packet to return the address of
1719 * \returns the base address of the packet buffer inside the transfer buffer,
1720 * or NULL if the packet does not exist.
1721 * \see libusb_get_iso_packet_buffer()
1723 static inline unsigned char *libusb_get_iso_packet_buffer_simple(
1724 struct libusb_transfer *transfer, unsigned int packet)
1728 /* oops..slight bug in the API. packet is an unsigned int, but we use
1729 * signed integers almost everywhere else. range-check and convert to
1730 * signed to avoid compiler warnings. FIXME for libusb-2. */
1731 if (packet > INT_MAX)
1733 _packet = (int) packet;
1735 if (_packet >= transfer->num_iso_packets)
1738 return transfer->buffer + ((int) transfer->iso_packet_desc[0].length * _packet);
1743 int LIBUSB_CALL libusb_control_transfer(libusb_device_handle *dev_handle,
1744 uint8_t request_type, uint8_t bRequest, uint16_t wValue, uint16_t wIndex,
1745 unsigned char *data, uint16_t wLength, unsigned int timeout);
1747 int LIBUSB_CALL libusb_bulk_transfer(libusb_device_handle *dev_handle,
1748 unsigned char endpoint, unsigned char *data, int length,
1749 int *actual_length, unsigned int timeout);
1751 int LIBUSB_CALL libusb_interrupt_transfer(libusb_device_handle *dev_handle,
1752 unsigned char endpoint, unsigned char *data, int length,
1753 int *actual_length, unsigned int timeout);
1756 * Retrieve a descriptor from the default control pipe.
1757 * This is a convenience function which formulates the appropriate control
1758 * message to retrieve the descriptor.
1760 * \param dev a device handle
1761 * \param desc_type the descriptor type, see \ref libusb_descriptor_type
1762 * \param desc_index the index of the descriptor to retrieve
1763 * \param data output buffer for descriptor
1764 * \param length size of data buffer
1765 * \returns number of bytes returned in data, or LIBUSB_ERROR code on failure
1767 static inline int libusb_get_descriptor(libusb_device_handle *dev,
1768 uint8_t desc_type, uint8_t desc_index, unsigned char *data, int length)
1770 return libusb_control_transfer(dev, LIBUSB_ENDPOINT_IN,
1771 LIBUSB_REQUEST_GET_DESCRIPTOR, (uint16_t) ((desc_type << 8) | desc_index),
1772 0, data, (uint16_t) length, 1000);
1776 * Retrieve a descriptor from a device.
1777 * This is a convenience function which formulates the appropriate control
1778 * message to retrieve the descriptor. The string returned is Unicode, as
1779 * detailed in the USB specifications.
1781 * \param dev a device handle
1782 * \param desc_index the index of the descriptor to retrieve
1783 * \param langid the language ID for the string descriptor
1784 * \param data output buffer for descriptor
1785 * \param length size of data buffer
1786 * \returns number of bytes returned in data, or LIBUSB_ERROR code on failure
1787 * \see libusb_get_string_descriptor_ascii()
1789 static inline int libusb_get_string_descriptor(libusb_device_handle *dev,
1790 uint8_t desc_index, uint16_t langid, unsigned char *data, int length)
1792 return libusb_control_transfer(dev, LIBUSB_ENDPOINT_IN,
1793 LIBUSB_REQUEST_GET_DESCRIPTOR, (uint16_t)((LIBUSB_DT_STRING << 8) | desc_index),
1794 langid, data, (uint16_t) length, 1000);
1797 int LIBUSB_CALL libusb_get_string_descriptor_ascii(libusb_device_handle *dev,
1798 uint8_t desc_index, unsigned char *data, int length);
1800 /* polling and timeouts */
1802 int LIBUSB_CALL libusb_try_lock_events(libusb_context *ctx);
1803 void LIBUSB_CALL libusb_lock_events(libusb_context *ctx);
1804 void LIBUSB_CALL libusb_unlock_events(libusb_context *ctx);
1805 int LIBUSB_CALL libusb_event_handling_ok(libusb_context *ctx);
1806 int LIBUSB_CALL libusb_event_handler_active(libusb_context *ctx);
1807 void LIBUSB_CALL libusb_lock_event_waiters(libusb_context *ctx);
1808 void LIBUSB_CALL libusb_unlock_event_waiters(libusb_context *ctx);
1809 int LIBUSB_CALL libusb_wait_for_event(libusb_context *ctx, struct timeval *tv);
1811 int LIBUSB_CALL libusb_handle_events_timeout(libusb_context *ctx,
1812 struct timeval *tv);
1813 int LIBUSB_CALL libusb_handle_events_timeout_completed(libusb_context *ctx,
1814 struct timeval *tv, int *completed);
1815 int LIBUSB_CALL libusb_handle_events(libusb_context *ctx);
1816 int LIBUSB_CALL libusb_handle_events_completed(libusb_context *ctx, int *completed);
1817 int LIBUSB_CALL libusb_handle_events_locked(libusb_context *ctx,
1818 struct timeval *tv);
1819 int LIBUSB_CALL libusb_pollfds_handle_timeouts(libusb_context *ctx);
1820 int LIBUSB_CALL libusb_get_next_timeout(libusb_context *ctx,
1821 struct timeval *tv);
1824 * File descriptor for polling
1826 struct libusb_pollfd {
1827 /** Numeric file descriptor */
1830 /** Event flags to poll for from <poll.h>. POLLIN indicates that you
1831 * should monitor this file descriptor for becoming ready to read from,
1832 * and POLLOUT indicates that you should monitor this file descriptor for
1833 * nonblocking write readiness. */
1838 * Callback function, invoked when a new file descriptor should be added
1839 * to the set of file descriptors monitored for events.
1840 * \param fd the new file descriptor
1841 * \param events events to monitor for, see \ref libusb_pollfd for a
1843 * \param user_data User data pointer specified in
1844 * libusb_set_pollfd_notifiers() call
1845 * \see libusb_set_pollfd_notifiers()
1847 typedef void (LIBUSB_CALL *libusb_pollfd_added_cb)(int fd, short events,
1851 * Callback function, invoked when a file descriptor should be removed from
1852 * the set of file descriptors being monitored for events. After returning
1853 * from this callback, do not use that file descriptor again.
1854 * \param fd the file descriptor to stop monitoring
1855 * \param user_data User data pointer specified in
1856 * libusb_set_pollfd_notifiers() call
1857 * \see libusb_set_pollfd_notifiers()
1859 typedef void (LIBUSB_CALL *libusb_pollfd_removed_cb)(int fd, void *user_data);
1861 const struct libusb_pollfd ** LIBUSB_CALL libusb_get_pollfds(
1862 libusb_context *ctx);
1863 void LIBUSB_CALL libusb_set_pollfd_notifiers(libusb_context *ctx,
1864 libusb_pollfd_added_cb added_cb, libusb_pollfd_removed_cb removed_cb,
1867 /** \ingroup hotplug
1870 * Callbacks handles are generated by libusb_hotplug_register_callback()
1871 * and can be used to deregister callbacks. Callback handles are unique
1872 * per libusb_context and it is safe to call libusb_hotplug_deregister_callback()
1873 * on an already deregisted callback.
1875 * Since version 1.0.16, \ref LIBUSB_API_VERSION >= 0x01000102
1877 * For more information, see \ref hotplug.
1879 typedef int libusb_hotplug_callback_handle;
1881 /** \ingroup hotplug
1883 * Since version 1.0.16, \ref LIBUSB_API_VERSION >= 0x01000102
1885 * Flags for hotplug events */
1887 /** Arm the callback and fire it for all matching currently attached devices. */
1888 LIBUSB_HOTPLUG_ENUMERATE = 1,
1889 } libusb_hotplug_flag;
1891 /** \ingroup hotplug
1893 * Since version 1.0.16, \ref LIBUSB_API_VERSION >= 0x01000102
1897 /** A device has been plugged in and is ready to use */
1898 LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED = 0x01,
1900 /** A device has left and is no longer available.
1901 * It is the user's responsibility to call libusb_close on any handle associated with a disconnected device.
1902 * It is safe to call libusb_get_device_descriptor on a device that has left */
1903 LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT = 0x02,
1904 } libusb_hotplug_event;
1906 /** \ingroup hotplug
1907 * Wildcard matching for hotplug events */
1908 #define LIBUSB_HOTPLUG_MATCH_ANY -1
1910 /** \ingroup hotplug
1911 * Hotplug callback function type. When requesting hotplug event notifications,
1912 * you pass a pointer to a callback function of this type.
1914 * This callback may be called by an internal event thread and as such it is
1915 * recommended the callback do minimal processing before returning.
1917 * libusb will call this function later, when a matching event had happened on
1918 * a matching device. See \ref hotplug for more information.
1920 * It is safe to call either libusb_hotplug_register_callback() or
1921 * libusb_hotplug_deregister_callback() from within a callback function.
1923 * Since version 1.0.16, \ref LIBUSB_API_VERSION >= 0x01000102
1925 * \param ctx context of this notification
1926 * \param device libusb_device this event occurred on
1927 * \param event event that occurred
1928 * \param user_data user data provided when this callback was registered
1929 * \returns bool whether this callback is finished processing events.
1930 * returning 1 will cause this callback to be deregistered
1932 typedef int (LIBUSB_CALL *libusb_hotplug_callback_fn)(libusb_context *ctx,
1933 libusb_device *device,
1934 libusb_hotplug_event event,
1937 /** \ingroup hotplug
1938 * Register a hotplug callback function
1940 * Register a callback with the libusb_context. The callback will fire
1941 * when a matching event occurs on a matching device. The callback is
1942 * armed until either it is deregistered with libusb_hotplug_deregister_callback()
1943 * or the supplied callback returns 1 to indicate it is finished processing events.
1945 * If the \ref LIBUSB_HOTPLUG_ENUMERATE is passed the callback will be
1946 * called with a \ref LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED for all devices
1947 * already plugged into the machine. Note that libusb modifies its internal
1948 * device list from a separate thread, while calling hotplug callbacks from
1949 * libusb_handle_events(), so it is possible for a device to already be present
1950 * on, or removed from, its internal device list, while the hotplug callbacks
1951 * still need to be dispatched. This means that when using \ref
1952 * LIBUSB_HOTPLUG_ENUMERATE, your callback may be called twice for the arrival
1953 * of the same device, once from libusb_hotplug_register_callback() and once
1954 * from libusb_handle_events(); and/or your callback may be called for the
1955 * removal of a device for which an arrived call was never made.
1957 * Since version 1.0.16, \ref LIBUSB_API_VERSION >= 0x01000102
1959 * \param[in] ctx context to register this callback with
1960 * \param[in] events bitwise or of events that will trigger this callback. See \ref
1961 * libusb_hotplug_event
1962 * \param[in] flags hotplug callback flags. See \ref libusb_hotplug_flag
1963 * \param[in] vendor_id the vendor id to match or \ref LIBUSB_HOTPLUG_MATCH_ANY
1964 * \param[in] product_id the product id to match or \ref LIBUSB_HOTPLUG_MATCH_ANY
1965 * \param[in] dev_class the device class to match or \ref LIBUSB_HOTPLUG_MATCH_ANY
1966 * \param[in] cb_fn the function to be invoked on a matching event/device
1967 * \param[in] user_data user data to pass to the callback function
1968 * \param[out] handle pointer to store the handle of the allocated callback (can be NULL)
1969 * \returns LIBUSB_SUCCESS on success LIBUSB_ERROR code on failure
1971 int LIBUSB_CALL libusb_hotplug_register_callback(libusb_context *ctx,
1972 libusb_hotplug_event events,
1973 libusb_hotplug_flag flags,
1974 int vendor_id, int product_id,
1976 libusb_hotplug_callback_fn cb_fn,
1978 libusb_hotplug_callback_handle *handle);
1980 /** \ingroup hotplug
1981 * Deregisters a hotplug callback.
1983 * Deregister a callback from a libusb_context. This function is safe to call from within
1984 * a hotplug callback.
1986 * Since version 1.0.16, \ref LIBUSB_API_VERSION >= 0x01000102
1988 * \param[in] ctx context this callback is registered with
1989 * \param[in] handle the handle of the callback to deregister
1991 void LIBUSB_CALL libusb_hotplug_deregister_callback(libusb_context *ctx,
1992 libusb_hotplug_callback_handle handle);