libusb{,20}.3: Add libusb to mdoc.local and adjust LIBRARY section.
[dragonfly.git] / lib / libusb / libusb20.3
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1.\"
2.\" Copyright (c) 2008 Hans Petter Selasky
3.\"
4.\" All rights reserved.
5.\"
6.\" Redistribution and use in source and binary forms, with or without
7.\" modification, are permitted provided that the following conditions
8.\" are met:
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.
14.\"
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
25.\" SUCH DAMAGE.
26.\"
9b0c1abe 27.\" $FreeBSD: head/lib/libusb/libusb20.3 250582 2013-05-12 22:22:12Z joel $
1d96047e 28.\"
9b0c1abe 29.Dd May 3, 2013
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30.Dt LIBUSB20 3
31.Os
32.Sh NAME
33.Nm libusb20
34.
35.Nd "USB access library"
36.
37.
38.Sh LIBRARY
39.
40.
a340784f 41.Lb libusb
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42.
43.
44.
45.Sh SYNOPSIS
46.In libusb20.h
47.Ft int
48.Fn libusb20_tr_close "struct libusb20_transfer *xfer"
49.Ft int
50.Fn libusb20_tr_open "struct libusb20_transfer *xfer" "uint32_t max_buf_size" "uint32_t max_frame_count" "uint8_t ep_no"
9b0c1abe 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"
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52.Ft struct libusb20_transfer*
53.Fn libusb20_tr_get_pointer "struct libusb20_device *pdev" "uint16_t tr_index"
54.Ft uint16_t
55.Fn libusb20_tr_get_time_complete "struct libusb20_transfer *xfer"
56.Ft uint32_t
57.Fn libusb20_tr_get_actual_frames "struct libusb20_transfer *xfer"
58.Ft uint32_t
59.Fn libusb20_tr_get_actual_length "struct libusb20_transfer *xfer"
60.Ft uint32_t
61.Fn libusb20_tr_get_max_frames "struct libusb20_transfer *xfer"
62.Ft uint32_t
63.Fn libusb20_tr_get_max_packet_length "struct libusb20_transfer *xfer"
64.Ft uint32_t
65.Fn libusb20_tr_get_max_total_length "struct libusb20_transfer *xfer"
66.Ft uint8_t
67.Fn libusb20_tr_get_status "struct libusb20_transfer *xfer"
68.Ft uint8_t
69.Fn libusb20_tr_pending "struct libusb20_transfer *xfer"
70.Ft void
71.Fn libusb20_tr_callback_wrapper "struct libusb20_transfer *xfer"
72.Ft void
73.Fn libusb20_tr_clear_stall_sync "struct libusb20_transfer *xfer"
74.Ft void
75.Fn libusb20_tr_drain "struct libusb20_transfer *xfer"
76.Ft void
77.Fn libusb20_tr_set_buffer "struct libusb20_transfer *xfer" "void *buffer" "uint16_t fr_index"
78.Ft void
79.Fn libusb20_tr_set_callback "struct libusb20_transfer *xfer" "libusb20_tr_callback_t *cb"
80.Ft void
81.Fn libusb20_tr_set_flags "struct libusb20_transfer *xfer" "uint8_t flags"
82.Ft uint32_t
83.Fn libusb20_tr_get_length "struct libusb20_transfer *xfer" "uint16_t fr_index"
84.Ft void
85.Fn libusb20_tr_set_length "struct libusb20_transfer *xfer" "uint32_t length" "uint16_t fr_index"
86.Ft void
87.Fn libusb20_tr_set_priv_sc0 "struct libusb20_transfer *xfer" "void *sc0"
88.Ft void
89.Fn libusb20_tr_set_priv_sc1 "struct libusb20_transfer *xfer" "void *sc1"
90.Ft void
91.Fn libusb20_tr_set_timeout "struct libusb20_transfer *xfer" "uint32_t timeout"
92.Ft void
93.Fn libusb20_tr_set_total_frames "struct libusb20_transfer *xfer" "uint32_t nframes"
94.Ft void
95.Fn libusb20_tr_setup_bulk "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint32_t timeout"
96.Ft void
97.Fn libusb20_tr_setup_control "struct libusb20_transfer *xfer" "void *psetup" "void *pbuf" "uint32_t timeout"
98.Ft void
99.Fn libusb20_tr_setup_intr "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint32_t timeout"
100.Ft void
9bfc1c11 101.Fn libusb20_tr_setup_isoc "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint16_t fr_index"
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102.Ft uint8_t
103.Fn libusb20_tr_bulk_intr_sync "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint32_t *pactlen" "uint32_t timeout"
104.Ft void
105.Fn libusb20_tr_start "struct libusb20_transfer *xfer"
106.Ft void
107.Fn libusb20_tr_stop "struct libusb20_transfer *xfer"
108.Ft void
109.Fn libusb20_tr_submit "struct libusb20_transfer *xfer"
110.Ft void *
111.Fn libusb20_tr_get_priv_sc0 "struct libusb20_transfer *xfer"
112.Ft void *
113.Fn libusb20_tr_get_priv_sc1 "struct libusb20_transfer *xfer"
114.Ft const char *
115.Fn libusb20_dev_get_backend_name "struct libusb20_device *"
116.Ft int
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117.Fn libusb20_dev_get_port_path "struct libusb20_device *pdev" "uint8_t *buf" "uint8_t bufsize"
118.Ft int
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119.Fn libusb20_dev_get_info "struct libusb20_device *pdev" "struct usb_device_info *pinfo"
120.Ft int
121.Fn libusb20_dev_get_iface_desc "struct libusb20_device *pdev" "uint8_t iface_index" "char *buf" "uint8_t len"
122.Ft const char *
123.Fn libusb20_dev_get_desc "struct libusb20_device *pdev"
124.Ft int
125.Fn libusb20_dev_close "struct libusb20_device *pdev"
126.Ft int
127.Fn libusb20_dev_detach_kernel_driver "struct libusb20_device *pdev" "uint8_t iface_index"
128.Ft int
129.Fn libusb20_dev_set_config_index "struct libusb20_device *pdev" "uint8_t configIndex"
130.Ft int
131.Fn libusb20_dev_get_debug "struct libusb20_device *pdev"
132.Ft int
133.Fn libusb20_dev_get_fd "struct libusb20_device *pdev"
134.Ft int
135.Fn libusb20_dev_kernel_driver_active "struct libusb20_device *pdev" "uint8_t iface_index"
136.Ft int
137.Fn libusb20_dev_open "struct libusb20_device *pdev" "uint16_t transfer_max"
138.Ft int
139.Fn libusb20_dev_process "struct libusb20_device *pdev"
140.Ft int
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"
142.Ft int
143.Fn libusb20_dev_req_string_sync "struct libusb20_device *pdev" "uint8_t index" "uint16_t langid" "void *ptr" "uint16_t len"
144.Ft int
145.Fn libusb20_dev_req_string_simple_sync "struct libusb20_device *pdev" "uint8_t index" "void *ptr" "uint16_t len"
146.Ft int
147.Fn libusb20_dev_reset "struct libusb20_device *pdev"
148.Ft int
149.Fn libusb20_dev_check_connected "struct libusb20_device *pdev"
150.Ft int
151.Fn libusb20_dev_set_power_mode "struct libusb20_device *pdev" "uint8_t power_mode"
152.Ft uint8_t
153.Fn libusb20_dev_get_power_mode "struct libusb20_device *pdev"
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154.Ft uint16_t
155.Fn libusb20_dev_get_power_usage "struct libusb20_device *pdev"
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156.Ft int
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"
164.Ft uint8_t
165.Fn libusb20_dev_get_address "struct libusb20_device *pdev"
166.Ft uint8_t
167.Fn libusb20_dev_get_parent_address "struct libusb20_device *pdev"
168.Ft uint8_t
169.Fn libusb20_dev_get_parent_port "struct libusb20_device *pdev"
170.Ft uint8_t
171.Fn libusb20_dev_get_bus_number "struct libusb20_device *pdev"
172.Ft uint8_t
173.Fn libusb20_dev_get_mode "struct libusb20_device *pdev"
174.Ft uint8_t
175.Fn libusb20_dev_get_speed "struct libusb20_device *pdev"
176.Ft uint8_t
177.Fn libusb20_dev_get_config_index "struct libusb20_device *pdev"
178.Ft void
179.Fn libusb20_dev_free "struct libusb20_device *pdev"
180.Ft void
181.Fn libusb20_dev_set_debug "struct libusb20_device *pdev" "int debug"
182.Ft void
183.Fn libusb20_dev_wait_process "struct libusb20_device *pdev" "int timeout"
184.Ft int
185.Fn libusb20_be_get_template "struct libusb20_backend *pbe" "int *ptemp"
186.Ft int
187.Fn libusb20_be_set_template "struct libusb20_backend *pbe" "int temp"
188.Ft int
189.Fn libusb20_be_get_dev_quirk "struct libusb20_backend *pber" "uint16_t index" "struct libusb20_quirk *pq"
190.Ft int
191.Fn libusb20_be_get_quirk_name "struct libusb20_backend *pbe" "uint16_t index" "struct libusb20_quirk *pq"
192.Ft int
193.Fn libusb20_be_add_dev_quirk "struct libusb20_backend *pbe" "struct libusb20_quirk *pq"
194.Ft int
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"
204.Ft void
205.Fn libusb20_be_dequeue_device "struct libusb20_backend *pbe" "struct libusb20_device *pdev"
206.Ft void
207.Fn libusb20_be_enqueue_device "struct libusb20_backend *pbe" "struct libusb20_device *pdev"
208.Ft void
209.Fn libusb20_be_free "struct libusb20_backend *pbe"
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210.Ft "const char *"
211.Fn libusb20_strerror "int code"
212.Ft "const char *"
213.Fn libusb20_error_name "int code"
214.In libusb20_desc.h
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215.Ft uint8_t
216.Fn libusb20_me_get_1 "const struct libusb20_me_struct *me" "uint16_t off"
217.Ft uint16_t
218.Fn libusb20_me_get_2 "const struct libusb20_me_struct *me" "uint16_t off"
219.Ft uint16_t
220.Fn libusb20_me_encode "void *pdata" "uint16_t len" "const void *pdecoded"
221.Ft uint16_t
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"
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225.
226.
227.Sh DESCRIPTION
228.
229The
230.Nm
231library implements functions to be able to easily access and control
232USB through the USB file system interface.
233The
234.Nm
235interfaces are specific to the
236.Fx
237usb stack and are not available on other operating systems, portable
238applications should consider using
239.Xr libusb 3 .
240.
241.
242.Sh USB TRANSFER OPERATIONS
243.
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244.
245.Fn libusb20_tr_close
246will release all kernel resources associated with an USB
247.Fa xfer .
248.
249This function returns zero upon success.
250.
251Non-zero return values indicate a LIBUSB20_ERROR value.
252.
253.Pp
254.
255.Fn libusb20_tr_open
256will allocate kernel buffer resources according to
257.Fa max_buf_size
258and
259.Fa max_frame_count
260associated with an USB
261.Fa pxfer
262and bind the transfer to the specified
263.Fa ep_no .
264.Fa max_buf_size
265is the minimum buffer size which the data transport layer has to support.
266If
267.Fa max_buf_size
268is zero, the
269.Nm
270library will use wMaxPacketSize to compute the buffer size.
271This can be useful for isochronous transfers.
272The actual buffer size can be greater than
273.Fa max_buf_size
274and is returned by
275.Fn libusb20_tr_get_max_total_length .
276.
277If
278.Fa max_frame_count
279is OR'ed with LIBUSB20_MAX_FRAME_PRE_SCALE the remaining part of the
280argument is converted from milliseconds into the actual number of
281frames rounded up, when this function returns.
282This flag is only valid for ISOCHRONOUS transfers and has no effect
283for other transfer types.
284The actual number of frames setup is found by calling
285.Fn libusb20_tr_get_max_frames .
286.
287This function returns zero upon success.
288.
289Non-zero return values indicate a LIBUSB20_ERROR value.
290.
291.Pp
292.
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293.Fn libusb20_tr_open_stream
294is identical to
295.Fn libusb20_tr_open
296except that a stream ID can be specified for BULK endpoints having
297such a feature.
298.Fn libusb20_tr_open
299can be used to open stream ID zero.
300.
301.Pp
302.
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303.Fn libusb20_tr_get_pointer
304will return a pointer to the allocated USB transfer according to the
305.Fa pdev
306and
307.Fa tr_index
308arguments.
309.
310This function returns NULL in case of failure.
311.
312.Pp
313.
314.Fn libusb20_tr_get_time_complete
315will return the completion time of an USB transfer in
316millisecond units. This function is most useful for isochronous USB
317transfers when doing echo cancelling.
318.
319.Pp
320.
321.Fn libusb20_tr_get_actual_frames
322will return the actual number of USB frames after an USB
323transfer completed. A value of zero means that no data was transferred.
324.
325.Pp
326.
327.Fn libusb20_tr_get_actual_length
328will return the sum of the actual length for all
329transferred USB frames for the given USB transfer.
330.
331.Pp
332.
333.Fn libusb20_tr_get_max_frames
334will return the maximum number of USB frames that were
335allocated when an USB transfer was setup for the given USB transfer.
336.
337.Pp
338.
339.Fn libusb20_tr_get_max_packet_length
340will return the maximum packet length in bytes
341associated with the given USB transfer.
342.
343The packet length can be used round up buffer sizes so that short USB
344packets are avoided for proxy buffers.
345.
346.
347.Pp
348.
349.Fn libusb20_tr_get_max_total_length
aa3e5c14 350will return the maximum value for the data length sum of all USB
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351frames associated with an USB transfer.
352In case of control transfers the value returned does not include the
353length of the SETUP packet, 8 bytes, which is part of frame zero.
354The returned value of this function is always aligned to the maximum
355packet size, wMaxPacketSize, of the endpoint which the USB transfer is
356bound to.
357.
358.Pp
359.
360.Fn libusb20_tr_get_status
361will return the status of an USB transfer.
362.
363Status values are defined by a set of LIBUSB20_TRANSFER_XXX enums.
364.
365.Pp
366.
367.Fn libusb20_tr_pending
368will return non-zero if the given USB transfer is
369pending for completion.
370.
371Else this function returns zero.
372.
373.Pp
374.
375.Fn libusb20_tr_callback_wrapper
376This is an internal function used to wrap asynchronous USB callbacks.
377.
378.Pp
379.
380.Fn libusb20_tr_clear_stall_sync
381This is an internal function used to synchronously clear the stall on
382the given USB transfer.
383.
384Please see the USB specification for more information on stall
385clearing.
386.
387If the given USB transfer is pending when this function is called, the
388USB transfer will complete with an error after that this function has
389been called.
390.
391.Pp
392.
393.Fn libusb20_tr_drain
394will stop the given USB transfer and will not return
395until the USB transfer has been stopped in hardware.
396.
397.Pp
398.
399.Fn libusb20_tr_set_buffer
400is used to set the
401.Fa buffer
402pointer for the given USB transfer and
403.Fa fr_index .
404.
405Typically the frame index is zero.
406.
407.
408.Pp
409.
410.Fn libusb20_tr_set_callback
411is used to set the USB callback for asynchronous USB
412transfers.
413.
414The callback type is defined by libusb20_tr_callback_t.
415.
416.Pp
417.
418.Fn libusb20_tr_set_flags
419is used to set various USB flags for the given USB transfer.
aa3e5c14 420.Bl -tag -width "LIBUSB20_TRANSFER_SINGLE_SHORT_NOT_OK"
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421.It LIBUSB20_TRANSFER_SINGLE_SHORT_NOT_OK
422Report a short frame as error.
423.It LIBUSB20_TRANSFER_MULTI_SHORT_NOT_OK
424Multiple short frames are not allowed.
425.It LIBUSB20_TRANSFER_FORCE_SHORT
426All transmitted frames are short terminated.
427.It LIBUSB20_TRANSFER_DO_CLEAR_STALL
428Will do a clear-stall before starting the transfer.
429.El
430.
431.Pp
432.
433.Fn libusb20_tr_get_length
434returns the length of the given USB frame by index.
435After an USB transfer is complete the USB frame length will get updated to the actual transferred length.
436.
437.Pp
438.
439.Fn libusb20_tr_set_length
440sets the length of the given USB frame by index.
441.
442.Pp
443.
444.Fn libusb20_tr_set_priv_sc0
445sets private driver pointer number zero.
446.
447.Pp
448.
449.Fn libusb20_tr_set_priv_sc1
450sets private driver pointer number one.
451.
452.Pp
453.
454.Fn libusb20_tr_set_timeout
455sets the timeout for the given USB transfer.
456.
457A timeout value of zero means no timeout.
458.
459The timeout is given in milliseconds.
460.
461.Pp
462.
463.Fn libusb20_tr_set_total_frames
464sets the total number of frames that should be executed when the USB transfer is submitted.
465.
466The total number of USB frames must be less than the maximum number of USB frames associated with the given USB transfer.
467.
468.Pp
469.
470.Fn libusb20_tr_setup_bulk
471is a helper function for setting up a single frame USB BULK transfer.
472.
473.Pp
474.
475.Fn libusb20_tr_setup_control
476is a helper function for setting up a single or dual
477frame USB CONTROL transfer depending on the control transfer length.
478.
479.Pp
480.
481.Fn libusb20_tr_setup_intr
482is a helper function for setting up a single frame USB INTERRUPT transfer.
483.
484.Pp
485.
486.Fn libusb20_tr_setup_isoc
487is a helper function for setting up a multi frame USB ISOCHRONOUS transfer.
488.
489.Pp
490.
491.Fn libusb20_tr_bulk_intr_sync
492will perform a synchronous BULK or INTERRUPT transfer having length given by the
493.Fa length
494argument and buffer pointer given by the
495.Fa pbuf
496argument on the USB transfer given by the
497.Fa xfer
498argument.
499.
500If the
501.Fa pactlen
502argument is non-NULL the actual transfer length will be stored at the given pointer destination.
503.
504If the
505.Fa timeout
506argument is non-zero the transfer will timeout after the given value in milliseconds.
507.
508This function does not change the transfer flags, like short packet not ok.
509.
510This function returns zero on success else a LIBUSB20_TRANSFER_XXX value is returned.
511.
512.Pp
513.
514.Fn libusb20_tr_start
515will get the USB transfer started, if not already
516started.
517.
518This function will not get the transfer queued in hardware.
519.
520This function is non-blocking.
521.
522.Pp
523.
524.Fn libusb20_tr_stop
525will get the USB transfer stopped, if not already stopped.
526.
527This function is non-blocking, which means that the actual stop can
528happen after the return of this function.
529.
530.Pp
531.
532.Fn libusb20_tr_submit
533will get the USB transfer queued in hardware.
534.
535.
536.Pp
537.
538.Fn libusb20_tr_get_priv_sc0
539returns private driver pointer number zero associated
540with an USB transfer.
541.
542.
543.Pp
544.
545.Fn libusb20_tr_get_priv_sc1
546returns private driver pointer number one associated
547with an USB transfer.
548.
549.
550.Sh USB DEVICE OPERATIONS
551.
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552.
553.Fn libusb20_dev_get_backend_name
554returns a zero terminated string describing the backend used.
555.
556.Pp
557.
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558.Fn libusb20_dev_get_port_path
559retrieves the list of USB port numbers which the datastream for a given USB device follows.
560The first port number is the Root HUB port number.
561Then children port numbers follow.
562The Root HUB device itself has a port path length of zero.
563Valid port numbers start at one and range until and including 255.
564Typically there should not be more than 16 levels, due to electrical and protocol limitations.
565This functions returns the number of actual port levels upon success
566else a LIBUSB20_ERROR value is returned which are always negative.
567If the actual number of port levels is greater than the maximum
568specified, a LIBUSB20_ERROR value is returned.
569.
570.Pp
571.
1d96047e 572.Fn libusb20_dev_get_info
aa3e5c14 573retrieves the BSD specific usb_device_info structure into the memory location given by
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574.Fa pinfo .
575The USB device given by
576.Fa pdev
577must be opened before this function will succeed.
578This function returns zero on success else a LIBUSB20_ERROR value is returned.
579.
580.Pp
581.
582.Fn libusb20_dev_get_iface_desc
583retrieves the kernel interface description for the given USB
584.Fa iface_index .
585The format of the USB interface description is: "drivername<unit>: <description>"
586The description string is always zero terminated.
587A zero length string is written in case no driver is attached to the given interface.
588The USB device given by
589.Fa pdev
590must be opened before this function will succeed.
591This function returns zero on success else a LIBUSB20_ERROR value is returned.
592.
593.Pp
594.
595.Fn libusb20_dev_get_desc
596returns a zero terminated string describing the given USB device.
597The format of the string is: "drivername<unit>: <description>"
598.
599.Pp
600.
601.Fn libusb20_dev_close
602will close the given USB device.
603.
604This function returns zero on success else a LIBUSB20_ERROR value is
605returned.
606.
607.Pp
608.
609.Fn libusb20_dev_detach_kernel_driver
610will try to detach the kernel driver for the USB interface given by
611.Fa iface_index .
612.
613This function returns zero on success else a LIBUSB20_ERROR value is
614returned.
615.
616.Pp
617.
618.Fn libusb20_dev_set_config_index
619will try to set the configuration index on an USB
620device.
621.
622The first configuration index is zero.
623.
624The un-configure index is 255.
625.
626This function returns zero on success else a LIBUSB20_ERROR value is returned.
627.
628.Pp
629.
630.Fn libusb20_dev_get_debug
631returns the debug level of an USB device.
632.
633.Pp
634.
635.Fn libusb20_dev_get_fd
636returns the file descriptor of the given USB device.
637.
638A negative value is returned when no file descriptor is present.
639.
640The file descriptor can be used for polling purposes.
641.
642.Pp
643.
644.Fn libusb20_dev_kernel_driver_active
645returns zero if a kernel driver is active on the given USB interface.
646.
647Else a LIBUSB20_ERROR value is returned.
648.
649.Pp
650.
651.Fn libusb20_dev_open
652opens an USB device so that setting up USB transfers
653becomes possible.
654.
655The number of USB transfers can be zero which means only control
656transfers are allowed.
657.
658This function returns zero on success else a LIBUSB20_ERROR value is
659returned.
660.
661A return value of LIBUSB20_ERROR_BUSY means that the device is already
662opened.
663.
664.Pp
665.
666.Fn libusb20_dev_process
667is called to sync kernel USB transfers with userland USB
668transfers.
669.
670This function returns zero on success else a LIBUSB20_ERROR value is
671returned typically indicating that the given USB device has been
672detached.
673.
674.Pp
675.
676.Fn libusb20_dev_request_sync
677will perform a synchronous control request on the given
678USB device.
679.
680Before this call will succeed the USB device must be opened.
681.
682.Fa setup
683is a pointer to a decoded and host endian SETUP packet.
684.Fa data
685is a pointer to a data transfer buffer associated with the control transaction. This argument can be NULL.
686.Fa pactlen
687is a pointer to a variable that will hold the actual transfer length after the control transaction is complete.
688.Fa timeout
689is the transaction timeout given in milliseconds.
690A timeout of zero means no timeout.
691.Fa flags
692is used to specify transaction flags, for example LIBUSB20_TRANSFER_SINGLE_SHORT_NOT_OK.
693.
694This function returns zero on success else a LIBUSB20_ERROR value is
695returned.
696.
697.Pp
698.
699.Fn libusb20_dev_req_string_sync
700will synchronously request an USB string by language ID
701and string index into the given buffer limited by a maximum length.
702.
703This function returns zero on success else a LIBUSB20_ERROR value is
704returned.
705.
706.Pp
707.
708.Fn libusb20_dev_req_string_simple_sync
709will synchronously request an USB string using the
710default language ID and convert the string into ASCII before storing
711the string into the given buffer limited by a maximum length which
712includes the terminating zero.
713.
714This function returns zero on success else a LIBUSB20_ERROR value is
715returned.
716.
717.
718.Pp
719.
720.Fn libusb20_dev_reset
721will try to BUS reset the given USB device and restore
722the last set USB configuration.
723.
724This function returns zero on success else a LIBUSB20_ERROR value is
725returned.
726.
727.
728.Pp
729.
730.Fn libusb20_dev_check_connected
731will check if an opened USB device is still connected.
732.
733This function returns zero if the device is still connected else a LIBUSB20_ERROR value is returned.
734.
735.
736.Pp
737.
738.Fn libusb20_dev_set_power_mode
739sets the power mode of the USB device.
740.
741Valid power modes:
aa3e5c14 742.Bl -tag -width "LIBUSB20_POWER_OFF"
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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
748.El
aa3e5c14 749.Pp
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750.
751This function returns zero on success else a LIBUSB20_ERROR value is
752returned.
753.
754.Pp
755.
756.Fn libusb20_dev_get_power_mode
757returns the currently selected power mode for the given
758USB device.
759.
760.Pp
761.
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762.Fn libusb20_dev_get_power_usage
763returns the reported power usage in milliamps for the given USB device.
764A power usage of zero typically means that the device is self powered.
765.
766.Pp
767.
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768.Fn libusb20_dev_set_alt_index
769will try to set the given alternate index for the given
770USB interface index.
771.
772This function returns zero on success else a LIBUSB20_ERROR value is
773returned.
774.
775.Pp
776.
777.Fn libusb20_dev_get_device_desc
778returns a pointer to the decoded and host endian version
779of the device descriptor.
780.
781The USB device need not be opened when calling this function.
782.
783.Pp
784.
785.Fn libusb20_dev_alloc_config
786will read out and decode the USB config descriptor for
787the given USB device and config index. This function returns a pointer
788to the decoded configuration which must eventually be passed to
789free(). NULL is returned in case of failure.
790.
791.Pp
792.
793.Fn libusb20_dev_alloc
794is an internal function to allocate a new USB device.
795.
796.Pp
797.
798.Fn libusb20_dev_get_address
799returns the internal and not necessarily the real
800hardware address of the given USB device.
801Valid addresses start at one.
802.
803.Pp
804.
805.Fn libusb20_dev_get_parent_address
806returns the internal and not necessarily the real hardware address of
807the given parent USB HUB device.
808This value is zero for the root HUB which usually has a device address
809equal to one.
810Valid addresses start at one.
811.
812.Pp
813.
814.Fn libusb20_dev_get_parent_port
815returns the port number on the parent USB HUB device.
816This value is zero for the root HUB which usually has a device address
817equal to one.
818Valid port numbers start at one.
819.
820.Pp
821.
822.Fn libusb20_dev_get_bus_number
823returns the internal bus number which the given USB
824device belongs to.
825Valid bus numbers start at zero.
826.
827.Pp
828.
829.Fn libusb20_dev_get_mode
830returns the current operation mode of the USB entity.
831.
832Valid return values are:
aa3e5c14 833.Bl -tag -width "LIBUSB20_MODE_DEVICE"
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834.It LIBUSB20_MODE_HOST
835.It LIBUSB20_MODE_DEVICE
836.El
837.
838.Pp
839.
840.Fn libusb20_dev_get_speed
841returns the current speed of the given USB device.
842.
aa3e5c14 843.Bl -tag -width "LIBUSB20_SPEED_VARIABLE"
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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
850.El
851.
852.Pp
853.
854.Fn libusb20_dev_get_config_index
aa3e5c14 855returns the currently selected config index for the given
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856USB device.
857.
858.Pp
859.
860.Fn libusb20_dev_free
861will free the given USB device and all associated USB
862transfers.
863.
864.Pp
865.
866.Fn libusb20_dev_set_debug
867will set the debug level for the given USB device.
868.
869.Pp
870.
871.Fn libusb20_dev_wait_process
aa3e5c14 872will wait until a pending USB transfer has completed on
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873the given USB device.
874.
875A timeout value can be specified which is passed on to the
876.Xr poll 2
877function.
878.
879.Sh USB BACKEND OPERATIONS
880.
881.Fn libusb20_be_get_template
882will return the currently selected global USB device
883side mode template into the integer pointer
884.Fa ptemp .
885This function returns zero on success else a LIBUSB20_ERROR value is
886returned.
887.
888.Pp
889.
890.Fn libusb20_be_set_template
891will set the global USB device side mode template to
892.Fa temp .
893The new template is not activated until after the next USB
894enumeration.
895The template number decides how the USB device will present itself to
6f7e3b2f
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896the USB Host, like Mass Storage Device, USB Ethernet Device.
897.\"Also see the
898.\".Xr usb2_template 4
899.\"module.
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900This function returns zero on success else a LIBUSB20_ERROR value is
901returned.
902.
903.Pp
904.
905.Fn libusb20_be_get_dev_quirk
aa3e5c14 906will return the device quirk according to
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907.Fa index
908into the libusb20_quirk structure pointed to by
909.Fa pq .
910This function returns zero on success else a LIBUSB20_ERROR value is
911returned.
912.
913If the given quirk does not exist LIBUSB20_ERROR_NOT_FOUND is
914returned.
915.
916.Pp
917.
918.Fn libusb20_be_get_quirk_name
919will return the quirk name according to
920.Fa index
921into the libusb20_quirk structure pointed to by
922.Fa pq .
923This function returns zero on success else a LIBUSB20_ERROR value is
924returned.
925.
926If the given quirk does not exist LIBUSB20_ERROR_NOT_FOUND is
927returned.
928.
929.Pp
930.
931.Fn libusb20_be_add_dev_quirk
932will add the libusb20_quirk structure pointed to by the
933.Fa pq
934argument into the device quirk list.
935.
936This function returns zero on success else a LIBUSB20_ERROR value is
937returned.
938.
939If the given quirk cannot be added LIBUSB20_ERROR_NO_MEM is
940returned.
941.
942.Pp
943.
944.Fn libusb20_be_remove_dev_quirk
945will remove the quirk matching the libusb20_quirk structure pointed to by the
946.Fa pq
947argument from the device quirk list.
948.
949This function returns zero on success else a LIBUSB20_ERROR value is
950returned.
951.
952If the given quirk does not exist LIBUSB20_ERROR_NOT_FOUND is
953returned.
954.
955.Pp
956.
957.Fn libusb20_be_alloc_default
958.Fn libusb20_be_alloc_freebsd
959.Fn libusb20_be_alloc_linux
960These functions are used to allocate a specific USB backend or the
961operating system default USB backend. Allocating a backend is a way to
962scan for currently present USB devices.
963.
964.Pp
965.
966.Fn libusb20_be_device_foreach
967is used to iterate USB devices present in a USB backend.
968.
969The starting value of
970.Fa pdev
971is NULL.
972.
973This function returns the next USB device in the list.
974.
975If NULL is returned the end of the USB device list has been reached.
976.
977.Pp
978.
979.Fn libusb20_be_dequeue_device
980will dequeue the given USB device pointer from the
981backend USB device list.
982.
983Dequeued USB devices will not be freed when the backend is freed.
984.
985.Pp
986.
987.Fn libusb20_be_enqueue_device
aa3e5c14 988will enqueue the given USB device pointer in the backend USB device list.
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989.
990Enqueued USB devices will get freed when the backend is freed.
991.
992.Pp
993.
994.Fn libusb20_be_free
995will free the given backend and all USB devices in its device list.
996.
997.
998.Sh USB DESCRIPTOR PARSING
999.
1000.Fn libusb20_me_get_1 pie offset
1001This function will return a byte at the given byte offset of a message
1002entity.
1003.
1004This function is safe against invalid offsets.
1005.
1006.Pp
1007.
1008.Fn libusb20_me_get_2 pie offset
1009This function will return a little endian 16-bit value at the given byte offset of a message
1010entity.
1011.
1012This function is safe against invalid offsets.
1013.
1014.Pp
1015.
1016.Fn libusb20_me_encode pbuf len pdecoded
1017This function will encode a so-called *DECODED structure into binary
1018format.
1019.
1020The total encoded length that will fit in the given buffer is
1021returned.
1022.
1023If the buffer pointer is NULL no data will be written to the buffer
1024location.
1025.
1026.Pp
1027.
1028.Fn libusb20_me_decode pbuf len pdecoded
1029This function will decode a binary structure into a so-called *DECODED
1030structure.
1031.
1032The total decoded length is returned.
1033.
1034The buffer pointer cannot be NULL.
1035.
1036.
1037.Sh USB DEBUGGING
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1038.Ft const char *
1039.Fn libusb20_strerror "int code"
1040Get the ASCII representation of the error given by the
1041.Fa code
1042argument.
1043This function does not return NULL.
1044.Pp
1045.Ft const char *
1046.Fn libusb20_error_name "int code"
1047Get the ASCII representation of the error enum given by the
1048.Fa code
1049argument.
1050This function does not return NULL.
1051.
1052.Sh FILES
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1053.Bl -tag -width Pa
1054.It Pa /dev/usb
1055.El
1d96047e 1056.Sh SEE ALSO
9b0c1abe 1057.Xr libusb 3 ,
7d196726 1058.Xr usb 4 ,
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1059.Xr usbconfig 8 ,
1060.Xr usbdump 8
1061.
1062.
1063.Sh HISTORY
1064.
1065.
1066Some parts of the
1067.Nm
1068API derives from the libusb project at sourceforge.