2 .\" Copyright (c) 2008 Hans Petter Selasky
4 .\" All rights reserved.
6 .\" Redistribution and use in source and binary forms, with or without
7 .\" modification, are permitted provided that the following conditions
9 .\" 1. Redistributions of source code must retain the above copyright
10 .\" notice, this list of conditions and the following disclaimer.
11 .\" 2. Redistributions in binary form must reproduce the above copyright
12 .\" notice, this list of conditions and the following disclaimer in the
13 .\" documentation and/or other materials provided with the distribution.
15 .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 .\" $FreeBSD: head/lib/libusb/libusb20.3 250582 2013-05-12 22:22:12Z joel $
35 .Nd "USB access library"
41 USB access library (libusb -lusb)
48 .Fn libusb20_tr_close "struct libusb20_transfer *xfer"
50 .Fn libusb20_tr_open "struct libusb20_transfer *xfer" "uint32_t max_buf_size" "uint32_t max_frame_count" "uint8_t ep_no"
51 .Fn libusb20_tr_open_stream "struct libusb20_transfer *xfer" "uint32_t max_buf_size" "uint32_t max_frame_count" "uint8_t ep_no" "uint16_t stream_id"
52 .Ft struct libusb20_transfer*
53 .Fn libusb20_tr_get_pointer "struct libusb20_device *pdev" "uint16_t tr_index"
55 .Fn libusb20_tr_get_time_complete "struct libusb20_transfer *xfer"
57 .Fn libusb20_tr_get_actual_frames "struct libusb20_transfer *xfer"
59 .Fn libusb20_tr_get_actual_length "struct libusb20_transfer *xfer"
61 .Fn libusb20_tr_get_max_frames "struct libusb20_transfer *xfer"
63 .Fn libusb20_tr_get_max_packet_length "struct libusb20_transfer *xfer"
65 .Fn libusb20_tr_get_max_total_length "struct libusb20_transfer *xfer"
67 .Fn libusb20_tr_get_status "struct libusb20_transfer *xfer"
69 .Fn libusb20_tr_pending "struct libusb20_transfer *xfer"
71 .Fn libusb20_tr_callback_wrapper "struct libusb20_transfer *xfer"
73 .Fn libusb20_tr_clear_stall_sync "struct libusb20_transfer *xfer"
75 .Fn libusb20_tr_drain "struct libusb20_transfer *xfer"
77 .Fn libusb20_tr_set_buffer "struct libusb20_transfer *xfer" "void *buffer" "uint16_t fr_index"
79 .Fn libusb20_tr_set_callback "struct libusb20_transfer *xfer" "libusb20_tr_callback_t *cb"
81 .Fn libusb20_tr_set_flags "struct libusb20_transfer *xfer" "uint8_t flags"
83 .Fn libusb20_tr_get_length "struct libusb20_transfer *xfer" "uint16_t fr_index"
85 .Fn libusb20_tr_set_length "struct libusb20_transfer *xfer" "uint32_t length" "uint16_t fr_index"
87 .Fn libusb20_tr_set_priv_sc0 "struct libusb20_transfer *xfer" "void *sc0"
89 .Fn libusb20_tr_set_priv_sc1 "struct libusb20_transfer *xfer" "void *sc1"
91 .Fn libusb20_tr_set_timeout "struct libusb20_transfer *xfer" "uint32_t timeout"
93 .Fn libusb20_tr_set_total_frames "struct libusb20_transfer *xfer" "uint32_t nframes"
95 .Fn libusb20_tr_setup_bulk "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint32_t timeout"
97 .Fn libusb20_tr_setup_control "struct libusb20_transfer *xfer" "void *psetup" "void *pbuf" "uint32_t timeout"
99 .Fn libusb20_tr_setup_intr "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint32_t timeout"
101 .Fn libusb20_tr_setup_isoc "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint16_t fr_index"
103 .Fn libusb20_tr_bulk_intr_sync "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint32_t *pactlen" "uint32_t timeout"
105 .Fn libusb20_tr_start "struct libusb20_transfer *xfer"
107 .Fn libusb20_tr_stop "struct libusb20_transfer *xfer"
109 .Fn libusb20_tr_submit "struct libusb20_transfer *xfer"
111 .Fn libusb20_tr_get_priv_sc0 "struct libusb20_transfer *xfer"
113 .Fn libusb20_tr_get_priv_sc1 "struct libusb20_transfer *xfer"
115 .Fn libusb20_dev_get_backend_name "struct libusb20_device *"
117 .Fn libusb20_dev_get_port_path "struct libusb20_device *pdev" "uint8_t *buf" "uint8_t bufsize"
119 .Fn libusb20_dev_get_info "struct libusb20_device *pdev" "struct usb_device_info *pinfo"
121 .Fn libusb20_dev_get_iface_desc "struct libusb20_device *pdev" "uint8_t iface_index" "char *buf" "uint8_t len"
123 .Fn libusb20_dev_get_desc "struct libusb20_device *pdev"
125 .Fn libusb20_dev_close "struct libusb20_device *pdev"
127 .Fn libusb20_dev_detach_kernel_driver "struct libusb20_device *pdev" "uint8_t iface_index"
129 .Fn libusb20_dev_set_config_index "struct libusb20_device *pdev" "uint8_t configIndex"
131 .Fn libusb20_dev_get_debug "struct libusb20_device *pdev"
133 .Fn libusb20_dev_get_fd "struct libusb20_device *pdev"
135 .Fn libusb20_dev_kernel_driver_active "struct libusb20_device *pdev" "uint8_t iface_index"
137 .Fn libusb20_dev_open "struct libusb20_device *pdev" "uint16_t transfer_max"
139 .Fn libusb20_dev_process "struct libusb20_device *pdev"
141 .Fn libusb20_dev_request_sync "struct libusb20_device *pdev" "struct LIBUSB20_CONTROL_SETUP_DECODED *setup" "void *data" "uint16_t *pactlen" "uint32_t timeout" "uint8_t flags"
143 .Fn libusb20_dev_req_string_sync "struct libusb20_device *pdev" "uint8_t index" "uint16_t langid" "void *ptr" "uint16_t len"
145 .Fn libusb20_dev_req_string_simple_sync "struct libusb20_device *pdev" "uint8_t index" "void *ptr" "uint16_t len"
147 .Fn libusb20_dev_reset "struct libusb20_device *pdev"
149 .Fn libusb20_dev_check_connected "struct libusb20_device *pdev"
151 .Fn libusb20_dev_set_power_mode "struct libusb20_device *pdev" "uint8_t power_mode"
153 .Fn libusb20_dev_get_power_mode "struct libusb20_device *pdev"
155 .Fn libusb20_dev_get_power_usage "struct libusb20_device *pdev"
157 .Fn libusb20_dev_set_alt_index "struct libusb20_device *pdev" "uint8_t iface_index" "uint8_t alt_index"
158 .Ft struct LIBUSB20_DEVICE_DESC_DECODED *
159 .Fn libusb20_dev_get_device_desc "struct libusb20_device *pdev"
160 .Ft struct libusb20_config *
161 .Fn libusb20_dev_alloc_config "struct libusb20_device *pdev" "uint8_t config_index"
162 .Ft struct libusb20_device *
163 .Fn libusb20_dev_alloc "void"
165 .Fn libusb20_dev_get_address "struct libusb20_device *pdev"
167 .Fn libusb20_dev_get_parent_address "struct libusb20_device *pdev"
169 .Fn libusb20_dev_get_parent_port "struct libusb20_device *pdev"
171 .Fn libusb20_dev_get_bus_number "struct libusb20_device *pdev"
173 .Fn libusb20_dev_get_mode "struct libusb20_device *pdev"
175 .Fn libusb20_dev_get_speed "struct libusb20_device *pdev"
177 .Fn libusb20_dev_get_config_index "struct libusb20_device *pdev"
179 .Fn libusb20_dev_free "struct libusb20_device *pdev"
181 .Fn libusb20_dev_set_debug "struct libusb20_device *pdev" "int debug"
183 .Fn libusb20_dev_wait_process "struct libusb20_device *pdev" "int timeout"
185 .Fn libusb20_be_get_template "struct libusb20_backend *pbe" "int *ptemp"
187 .Fn libusb20_be_set_template "struct libusb20_backend *pbe" "int temp"
189 .Fn libusb20_be_get_dev_quirk "struct libusb20_backend *pber" "uint16_t index" "struct libusb20_quirk *pq"
191 .Fn libusb20_be_get_quirk_name "struct libusb20_backend *pbe" "uint16_t index" "struct libusb20_quirk *pq"
193 .Fn libusb20_be_add_dev_quirk "struct libusb20_backend *pbe" "struct libusb20_quirk *pq"
195 .Fn libusb20_be_remove_dev_quirk "struct libusb20_backend *pbe" "struct libusb20_quirk *pq"
196 .Ft struct libusb20_backend *
197 .Fn libusb20_be_alloc_default "void"
198 .Ft struct libusb20_backend *
199 .Fn libusb20_be_alloc_freebsd "void"
200 .Ft struct libusb20_backend *
201 .Fn libusb20_be_alloc_linux "void"
202 .Ft struct libusb20_device *
203 .Fn libusb20_be_device_foreach "struct libusb20_backend *pbe" "struct libusb20_device *pdev"
205 .Fn libusb20_be_dequeue_device "struct libusb20_backend *pbe" "struct libusb20_device *pdev"
207 .Fn libusb20_be_enqueue_device "struct libusb20_backend *pbe" "struct libusb20_device *pdev"
209 .Fn libusb20_be_free "struct libusb20_backend *pbe"
211 .Fn libusb20_strerror "int code"
213 .Fn libusb20_error_name "int code"
216 .Fn libusb20_me_get_1 "const struct libusb20_me_struct *me" "uint16_t off"
218 .Fn libusb20_me_get_2 "const struct libusb20_me_struct *me" "uint16_t off"
220 .Fn libusb20_me_encode "void *pdata" "uint16_t len" "const void *pdecoded"
222 .Fn libusb20_me_decode "const void *pdata" "uint16_t len" "void *pdecoded"
223 .Ft "const uint8_t *"
224 .Fn libusb20_desc_foreach "const struct libusb20_me_struct *me" "const uint8_t *pdesc"
231 library implements functions to be able to easily access and control
232 USB through the USB file system interface.
235 interfaces are specific to the
237 usb stack and are not available on other operating systems, portable
238 applications should consider using
242 .Sh USB TRANSFER OPERATIONS
245 .Fn libusb20_tr_close
246 will release all kernel resources associated with an USB
249 This function returns zero upon success.
251 Non-zero return values indicate a LIBUSB20_ERROR value.
256 will allocate kernel buffer resources according to
260 associated with an USB
262 and bind the transfer to the specified
265 is the minimum buffer size which the data transport layer has to support.
270 library will use wMaxPacketSize to compute the buffer size.
271 This can be useful for isochronous transfers.
272 The actual buffer size can be greater than
275 .Fn libusb20_tr_get_max_total_length .
279 is OR'ed with LIBUSB20_MAX_FRAME_PRE_SCALE the remaining part of the
280 argument is converted from milliseconds into the actual number of
281 frames rounded up, when this function returns.
282 This flag is only valid for ISOCHRONOUS transfers and has no effect
283 for other transfer types.
284 The actual number of frames setup is found by calling
285 .Fn libusb20_tr_get_max_frames .
287 This function returns zero upon success.
289 Non-zero return values indicate a LIBUSB20_ERROR value.
293 .Fn libusb20_tr_open_stream
296 except that a stream ID can be specified for BULK endpoints having
299 can be used to open stream ID zero.
303 .Fn libusb20_tr_get_pointer
304 will return a pointer to the allocated USB transfer according to the
310 This function returns NULL in case of failure.
314 .Fn libusb20_tr_get_time_complete
315 will return the completion time of an USB transfer in
316 millisecond units. This function is most useful for isochronous USB
317 transfers when doing echo cancelling.
321 .Fn libusb20_tr_get_actual_frames
322 will return the actual number of USB frames after an USB
323 transfer completed. A value of zero means that no data was transferred.
327 .Fn libusb20_tr_get_actual_length
328 will return the sum of the actual length for all
329 transferred USB frames for the given USB transfer.
333 .Fn libusb20_tr_get_max_frames
334 will return the maximum number of USB frames that were
335 allocated when an USB transfer was setup for the given USB transfer.
339 .Fn libusb20_tr_get_max_packet_length
340 will return the maximum packet length in bytes
341 associated with the given USB transfer.
343 The packet length can be used round up buffer sizes so that short USB
344 packets are avoided for proxy buffers.
349 .Fn libusb20_tr_get_max_total_length
350 will return the maximum value for the data length sum of all USB
351 frames associated with an USB transfer.
352 In case of control transfers the value returned does not include the
353 length of the SETUP packet, 8 bytes, which is part of frame zero.
354 The returned value of this function is always aligned to the maximum
355 packet size, wMaxPacketSize, of the endpoint which the USB transfer is
360 .Fn libusb20_tr_get_status
361 will return the status of an USB transfer.
363 Status values are defined by a set of LIBUSB20_TRANSFER_XXX enums.
367 .Fn libusb20_tr_pending
368 will return non-zero if the given USB transfer is
369 pending for completion.
371 Else this function returns zero.
375 .Fn libusb20_tr_callback_wrapper
376 This is an internal function used to wrap asynchronous USB callbacks.
380 .Fn libusb20_tr_clear_stall_sync
381 This is an internal function used to synchronously clear the stall on
382 the given USB transfer.
384 Please see the USB specification for more information on stall
387 If the given USB transfer is pending when this function is called, the
388 USB transfer will complete with an error after that this function has
393 .Fn libusb20_tr_drain
394 will stop the given USB transfer and will not return
395 until the USB transfer has been stopped in hardware.
399 .Fn libusb20_tr_set_buffer
402 pointer for the given USB transfer and
405 Typically the frame index is zero.
410 .Fn libusb20_tr_set_callback
411 is used to set the USB callback for asynchronous USB
414 The callback type is defined by libusb20_tr_callback_t.
418 .Fn libusb20_tr_set_flags
419 is used to set various USB flags for the given USB transfer.
420 .Bl -tag -width "LIBUSB20_TRANSFER_SINGLE_SHORT_NOT_OK"
421 .It LIBUSB20_TRANSFER_SINGLE_SHORT_NOT_OK
422 Report a short frame as error.
423 .It LIBUSB20_TRANSFER_MULTI_SHORT_NOT_OK
424 Multiple short frames are not allowed.
425 .It LIBUSB20_TRANSFER_FORCE_SHORT
426 All transmitted frames are short terminated.
427 .It LIBUSB20_TRANSFER_DO_CLEAR_STALL
428 Will do a clear-stall before starting the transfer.
433 .Fn libusb20_tr_get_length
434 returns the length of the given USB frame by index.
435 After an USB transfer is complete the USB frame length will get updated to the actual transferred length.
439 .Fn libusb20_tr_set_length
440 sets the length of the given USB frame by index.
444 .Fn libusb20_tr_set_priv_sc0
445 sets private driver pointer number zero.
449 .Fn libusb20_tr_set_priv_sc1
450 sets private driver pointer number one.
454 .Fn libusb20_tr_set_timeout
455 sets the timeout for the given USB transfer.
457 A timeout value of zero means no timeout.
459 The timeout is given in milliseconds.
463 .Fn libusb20_tr_set_total_frames
464 sets the total number of frames that should be executed when the USB transfer is submitted.
466 The total number of USB frames must be less than the maximum number of USB frames associated with the given USB transfer.
470 .Fn libusb20_tr_setup_bulk
471 is a helper function for setting up a single frame USB BULK transfer.
475 .Fn libusb20_tr_setup_control
476 is a helper function for setting up a single or dual
477 frame USB CONTROL transfer depending on the control transfer length.
481 .Fn libusb20_tr_setup_intr
482 is a helper function for setting up a single frame USB INTERRUPT transfer.
486 .Fn libusb20_tr_setup_isoc
487 is a helper function for setting up a multi frame USB ISOCHRONOUS transfer.
491 .Fn libusb20_tr_bulk_intr_sync
492 will perform a synchronous BULK or INTERRUPT transfer having length given by the
494 argument and buffer pointer given by the
496 argument on the USB transfer given by the
502 argument is non-NULL the actual transfer length will be stored at the given pointer destination.
506 argument is non-zero the transfer will timeout after the given value in milliseconds.
508 This function does not change the transfer flags, like short packet not ok.
510 This function returns zero on success else a LIBUSB20_TRANSFER_XXX value is returned.
514 .Fn libusb20_tr_start
515 will get the USB transfer started, if not already
518 This function will not get the transfer queued in hardware.
520 This function is non-blocking.
525 will get the USB transfer stopped, if not already stopped.
527 This function is non-blocking, which means that the actual stop can
528 happen after the return of this function.
532 .Fn libusb20_tr_submit
533 will get the USB transfer queued in hardware.
538 .Fn libusb20_tr_get_priv_sc0
539 returns private driver pointer number zero associated
540 with an USB transfer.
545 .Fn libusb20_tr_get_priv_sc1
546 returns private driver pointer number one associated
547 with an USB transfer.
550 .Sh USB DEVICE OPERATIONS
553 .Fn libusb20_dev_get_backend_name
554 returns a zero terminated string describing the backend used.
558 .Fn libusb20_dev_get_port_path
559 retrieves the list of USB port numbers which the datastream for a given USB device follows.
560 The first port number is the Root HUB port number.
561 Then children port numbers follow.
562 The Root HUB device itself has a port path length of zero.
563 Valid port numbers start at one and range until and including 255.
564 Typically there should not be more than 16 levels, due to electrical and protocol limitations.
565 This functions returns the number of actual port levels upon success
566 else a LIBUSB20_ERROR value is returned which are always negative.
567 If the actual number of port levels is greater than the maximum
568 specified, a LIBUSB20_ERROR value is returned.
572 .Fn libusb20_dev_get_info
573 retrieves the BSD specific usb_device_info structure into the memory location given by
575 The USB device given by
577 must be opened before this function will succeed.
578 This function returns zero on success else a LIBUSB20_ERROR value is returned.
582 .Fn libusb20_dev_get_iface_desc
583 retrieves the kernel interface description for the given USB
585 The format of the USB interface description is: "drivername<unit>: <description>"
586 The description string is always zero terminated.
587 A zero length string is written in case no driver is attached to the given interface.
588 The USB device given by
590 must be opened before this function will succeed.
591 This function returns zero on success else a LIBUSB20_ERROR value is returned.
595 .Fn libusb20_dev_get_desc
596 returns a zero terminated string describing the given USB device.
597 The format of the string is: "drivername<unit>: <description>"
601 .Fn libusb20_dev_close
602 will close the given USB device.
604 This function returns zero on success else a LIBUSB20_ERROR value is
609 .Fn libusb20_dev_detach_kernel_driver
610 will try to detach the kernel driver for the USB interface given by
613 This function returns zero on success else a LIBUSB20_ERROR value is
618 .Fn libusb20_dev_set_config_index
619 will try to set the configuration index on an USB
622 The first configuration index is zero.
624 The un-configure index is 255.
626 This function returns zero on success else a LIBUSB20_ERROR value is returned.
630 .Fn libusb20_dev_get_debug
631 returns the debug level of an USB device.
635 .Fn libusb20_dev_get_fd
636 returns the file descriptor of the given USB device.
638 A negative value is returned when no file descriptor is present.
640 The file descriptor can be used for polling purposes.
644 .Fn libusb20_dev_kernel_driver_active
645 returns zero if a kernel driver is active on the given USB interface.
647 Else a LIBUSB20_ERROR value is returned.
651 .Fn libusb20_dev_open
652 opens an USB device so that setting up USB transfers
655 The number of USB transfers can be zero which means only control
656 transfers are allowed.
658 This function returns zero on success else a LIBUSB20_ERROR value is
661 A return value of LIBUSB20_ERROR_BUSY means that the device is already
666 .Fn libusb20_dev_process
667 is called to sync kernel USB transfers with userland USB
670 This function returns zero on success else a LIBUSB20_ERROR value is
671 returned typically indicating that the given USB device has been
676 .Fn libusb20_dev_request_sync
677 will perform a synchronous control request on the given
680 Before this call will succeed the USB device must be opened.
683 is a pointer to a decoded and host endian SETUP packet.
685 is a pointer to a data transfer buffer associated with the control transaction. This argument can be NULL.
687 is a pointer to a variable that will hold the actual transfer length after the control transaction is complete.
689 is the transaction timeout given in milliseconds.
690 A timeout of zero means no timeout.
692 is used to specify transaction flags, for example LIBUSB20_TRANSFER_SINGLE_SHORT_NOT_OK.
694 This function returns zero on success else a LIBUSB20_ERROR value is
699 .Fn libusb20_dev_req_string_sync
700 will synchronously request an USB string by language ID
701 and string index into the given buffer limited by a maximum length.
703 This function returns zero on success else a LIBUSB20_ERROR value is
708 .Fn libusb20_dev_req_string_simple_sync
709 will synchronously request an USB string using the
710 default language ID and convert the string into ASCII before storing
711 the string into the given buffer limited by a maximum length which
712 includes the terminating zero.
714 This function returns zero on success else a LIBUSB20_ERROR value is
720 .Fn libusb20_dev_reset
721 will try to BUS reset the given USB device and restore
722 the last set USB configuration.
724 This function returns zero on success else a LIBUSB20_ERROR value is
730 .Fn libusb20_dev_check_connected
731 will check if an opened USB device is still connected.
733 This function returns zero if the device is still connected else a LIBUSB20_ERROR value is returned.
738 .Fn libusb20_dev_set_power_mode
739 sets the power mode of the USB device.
742 .Bl -tag -width "LIBUSB20_POWER_OFF"
743 .It LIBUSB20_POWER_OFF
744 .It LIBUSB20_POWER_ON
745 .It LIBUSB20_POWER_SAVE
746 .It LIBUSB20_POWER_SUSPEND
747 .It LIBUSB20_POWER_RESUME
751 This function returns zero on success else a LIBUSB20_ERROR value is
756 .Fn libusb20_dev_get_power_mode
757 returns the currently selected power mode for the given
762 .Fn libusb20_dev_get_power_usage
763 returns the reported power usage in milliamps for the given USB device.
764 A power usage of zero typically means that the device is self powered.
768 .Fn libusb20_dev_set_alt_index
769 will try to set the given alternate index for the given
772 This function returns zero on success else a LIBUSB20_ERROR value is
777 .Fn libusb20_dev_get_device_desc
778 returns a pointer to the decoded and host endian version
779 of the device descriptor.
781 The USB device need not be opened when calling this function.
785 .Fn libusb20_dev_alloc_config
786 will read out and decode the USB config descriptor for
787 the given USB device and config index. This function returns a pointer
788 to the decoded configuration which must eventually be passed to
789 free(). NULL is returned in case of failure.
793 .Fn libusb20_dev_alloc
794 is an internal function to allocate a new USB device.
798 .Fn libusb20_dev_get_address
799 returns the internal and not necessarily the real
800 hardware address of the given USB device.
801 Valid addresses start at one.
805 .Fn libusb20_dev_get_parent_address
806 returns the internal and not necessarily the real hardware address of
807 the given parent USB HUB device.
808 This value is zero for the root HUB which usually has a device address
810 Valid addresses start at one.
814 .Fn libusb20_dev_get_parent_port
815 returns the port number on the parent USB HUB device.
816 This value is zero for the root HUB which usually has a device address
818 Valid port numbers start at one.
822 .Fn libusb20_dev_get_bus_number
823 returns the internal bus number which the given USB
825 Valid bus numbers start at zero.
829 .Fn libusb20_dev_get_mode
830 returns the current operation mode of the USB entity.
832 Valid return values are:
833 .Bl -tag -width "LIBUSB20_MODE_DEVICE"
834 .It LIBUSB20_MODE_HOST
835 .It LIBUSB20_MODE_DEVICE
840 .Fn libusb20_dev_get_speed
841 returns the current speed of the given USB device.
843 .Bl -tag -width "LIBUSB20_SPEED_VARIABLE"
844 .It LIBUSB20_SPEED_UNKNOWN
845 .It LIBUSB20_SPEED_LOW
846 .It LIBUSB20_SPEED_FULL
847 .It LIBUSB20_SPEED_HIGH
848 .It LIBUSB20_SPEED_VARIABLE
849 .It LIBUSB20_SPEED_SUPER
854 .Fn libusb20_dev_get_config_index
855 returns the currently selected config index for the given
860 .Fn libusb20_dev_free
861 will free the given USB device and all associated USB
866 .Fn libusb20_dev_set_debug
867 will set the debug level for the given USB device.
871 .Fn libusb20_dev_wait_process
872 will wait until a pending USB transfer has completed on
873 the given USB device.
875 A timeout value can be specified which is passed on to the
879 .Sh USB BACKEND OPERATIONS
881 .Fn libusb20_be_get_template
882 will return the currently selected global USB device
883 side mode template into the integer pointer
885 This function returns zero on success else a LIBUSB20_ERROR value is
890 .Fn libusb20_be_set_template
891 will set the global USB device side mode template to
893 The new template is not activated until after the next USB
895 The template number decides how the USB device will present itself to
896 the USB Host, like Mass Storage Device, USB Ethernet Device.
898 .\".Xr usb2_template 4
900 This function returns zero on success else a LIBUSB20_ERROR value is
905 .Fn libusb20_be_get_dev_quirk
906 will return the device quirk according to
908 into the libusb20_quirk structure pointed to by
910 This function returns zero on success else a LIBUSB20_ERROR value is
913 If the given quirk does not exist LIBUSB20_ERROR_NOT_FOUND is
918 .Fn libusb20_be_get_quirk_name
919 will return the quirk name according to
921 into the libusb20_quirk structure pointed to by
923 This function returns zero on success else a LIBUSB20_ERROR value is
926 If the given quirk does not exist LIBUSB20_ERROR_NOT_FOUND is
931 .Fn libusb20_be_add_dev_quirk
932 will add the libusb20_quirk structure pointed to by the
934 argument into the device quirk list.
936 This function returns zero on success else a LIBUSB20_ERROR value is
939 If the given quirk cannot be added LIBUSB20_ERROR_NO_MEM is
944 .Fn libusb20_be_remove_dev_quirk
945 will remove the quirk matching the libusb20_quirk structure pointed to by the
947 argument from the device quirk list.
949 This function returns zero on success else a LIBUSB20_ERROR value is
952 If the given quirk does not exist LIBUSB20_ERROR_NOT_FOUND is
957 .Fn libusb20_be_alloc_default
958 .Fn libusb20_be_alloc_freebsd
959 .Fn libusb20_be_alloc_linux
960 These functions are used to allocate a specific USB backend or the
961 operating system default USB backend. Allocating a backend is a way to
962 scan for currently present USB devices.
966 .Fn libusb20_be_device_foreach
967 is used to iterate USB devices present in a USB backend.
969 The starting value of
973 This function returns the next USB device in the list.
975 If NULL is returned the end of the USB device list has been reached.
979 .Fn libusb20_be_dequeue_device
980 will dequeue the given USB device pointer from the
981 backend USB device list.
983 Dequeued USB devices will not be freed when the backend is freed.
987 .Fn libusb20_be_enqueue_device
988 will enqueue the given USB device pointer in the backend USB device list.
990 Enqueued USB devices will get freed when the backend is freed.
995 will free the given backend and all USB devices in its device list.
998 .Sh USB DESCRIPTOR PARSING
1000 .Fn libusb20_me_get_1 pie offset
1001 This function will return a byte at the given byte offset of a message
1004 This function is safe against invalid offsets.
1008 .Fn libusb20_me_get_2 pie offset
1009 This function will return a little endian 16-bit value at the given byte offset of a message
1012 This function is safe against invalid offsets.
1016 .Fn libusb20_me_encode pbuf len pdecoded
1017 This function will encode a so-called *DECODED structure into binary
1020 The total encoded length that will fit in the given buffer is
1023 If the buffer pointer is NULL no data will be written to the buffer
1028 .Fn libusb20_me_decode pbuf len pdecoded
1029 This function will decode a binary structure into a so-called *DECODED
1032 The total decoded length is returned.
1034 The buffer pointer cannot be NULL.
1039 .Fn libusb20_strerror "int code"
1040 Get the ASCII representation of the error given by the
1043 This function does not return NULL.
1046 .Fn libusb20_error_name "int code"
1047 Get the ASCII representation of the error enum given by the
1050 This function does not return NULL.
1068 API derives from the libusb project at sourceforge.