2 .\" Copyright (c) 2005 Ian Dowse <iedowse@FreeBSD.org>
3 .\" All rights reserved.
5 .\" Redistribution and use in source and binary forms, with or without
6 .\" modification, are permitted provided that the following conditions
8 .\" 1. Redistributions of source code must retain the above copyright
9 .\" notice, this list of conditions and the following disclaimer.
10 .\" 2. Redistributions in binary form must reproduce the above copyright
11 .\" notice, this list of conditions and the following disclaimer in the
12 .\" documentation and/or other materials provided with the distribution.
14 .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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26 .\" $FreeBSD: head/share/man/man9/usbdi.9 235693 2012-05-20 16:43:47Z gjb $
31 .Nm usb_fifo_alloc_buffer ,
34 .Nm usb_fifo_free_buffer ,
35 .Nm usb_fifo_get_data ,
36 .Nm usb_fifo_get_data_buffer ,
37 .Nm usb_fifo_get_data_error ,
38 .Nm usb_fifo_get_data_linear ,
39 .Nm usb_fifo_put_bytes_max ,
40 .Nm usb_fifo_put_data ,
41 .Nm usb_fifo_put_data_buffer ,
42 .Nm usb_fifo_put_data_error ,
43 .Nm usb_fifo_put_data_linear ,
48 .Nm usbd_do_request_flags ,
50 .Nm usbd_lookup_id_by_info ,
51 .Nm usbd_lookup_id_by_uaa ,
52 .Nm usbd_transfer_clear_stall ,
53 .Nm usbd_transfer_drain ,
54 .Nm usbd_transfer_pending ,
55 .Nm usbd_transfer_poll ,
56 .Nm usbd_transfer_setup ,
57 .Nm usbd_transfer_start ,
58 .Nm usbd_transfer_stop ,
59 .Nm usbd_transfer_submit ,
60 .Nm usbd_transfer_unsetup ,
61 .Nm usbd_xfer_clr_flag ,
62 .Nm usbd_xfer_frame_data ,
63 .Nm usbd_xfer_frame_len ,
64 .Nm usbd_xfer_get_frame ,
65 .Nm usbd_xfer_get_priv ,
66 .Nm usbd_xfer_is_stalled ,
67 .Nm usbd_xfer_max_framelen ,
68 .Nm usbd_xfer_max_frames ,
69 .Nm usbd_xfer_max_len ,
70 .Nm usbd_xfer_set_flag ,
71 .Nm usbd_xfer_set_frame_data ,
72 .Nm usbd_xfer_set_frame_len ,
73 .Nm usbd_xfer_set_frame_offset ,
74 .Nm usbd_xfer_set_frames ,
75 .Nm usbd_xfer_set_interval ,
76 .Nm usbd_xfer_set_priv ,
77 .Nm usbd_xfer_set_stall ,
78 .Nm usbd_xfer_set_timeout ,
82 .Nd Universal Serial Bus driver programming interface
86 .In bus/u4b/usbdi_util.h
88 The Universal Serial Bus (USB) driver programming interface provides
89 USB peripheral drivers with a host controller independent API for
90 controlling and communicating with USB peripherals.
93 module supports both USB Host and USB Device side mode.
95 .Sh USB KERNEL PROGRAMMING
96 Here is a list of commonly used functions:
100 .Fo "usbd_transfer_setup"
113 .Fo "usbd_transfer_unsetup"
121 .Fo "usbd_transfer_start"
128 .Fo "usbd_transfer_stop"
135 .Fo "usbd_transfer_drain"
141 .Sh USB TRANSFER MANAGEMENT FUNCTIONS
142 The USB standard defines four types of USB transfers.
144 Control transfers, Bulk transfers, Interrupt transfers and Isochronous
147 All the transfer types are managed using the following five functions:
151 .Fn usbd_transfer_setup
152 This function will allocate memory for and initialise an array of USB
153 transfers and all required DMA memory.
155 This function can sleep or block waiting for resources to become
158 is a pointer to "struct usb_device".
160 is an array of interface index numbers to use
163 is a pointer to an array of USB transfer pointers that are initialized
164 to NULL, and then pointed to allocated USB transfers.
166 is a pointer to an array of USB config structures.
168 is a number telling the USB system how many USB transfers should be
171 is the private softc pointer, which will be used to initialize
174 is the private mutex protecting the transfer structure and the
176 This pointer is used to initialize "xfer->priv_mtx".
177 This function returns
179 A non-zero return value indicates failure.
183 .Fn usbd_transfer_unsetup
184 This function will release the given USB transfers and all allocated
185 resources associated with these USB transfers.
187 is a pointer to an array of USB transfer pointers, that may be NULL,
188 that should be freed by the USB system.
190 is a number telling the USB system how many USB transfers should be
193 This function can sleep waiting for USB transfers to complete.
195 This function is NULL safe with regard to the USB transfer structure
198 It is not allowed to call this function from the USB transfer
203 .Fn usbd_transfer_start
204 This function will start the USB transfer pointed to by
206 if not already started.
208 This function is always non-blocking and must be called with the
209 so-called private USB mutex locked.
211 This function is NULL safe with regard to the USB transfer structure
216 .Fn usbd_transfer_stop
217 This function will stop the USB transfer pointed to by
219 if not already stopped.
221 This function is always non-blocking and must be called with the
222 so-called private USB mutex locked.
224 This function can return before the USB callback has been called.
226 This function is NULL safe with regard to the USB transfer structure
229 If the transfer was in progress, the callback will called with
230 "USB_ST_ERROR" and "error = USB_ERR_CANCELLED".
234 .Fn usbd_transfer_drain
235 This function will stop an USB transfer, if not already stopped and
236 wait for any additional USB hardware operations to complete.
238 Buffers that are loaded into DMA using "usbd_xfer_set_frame_data()" can
239 safely be freed after that this function has returned.
241 This function can block the caller and will not return before the USB
242 callback has been called.
244 This function is NULL safe with regard to the USB transfer structure
247 .Sh USB TRANSFER CALLBACK
249 The USB callback has three states.
251 USB_ST_SETUP, USB_ST_TRANSFERRED and USB_ST_ERROR.
252 USB_ST_SETUP is the initial state.
254 After the callback has been called with this state it will always be
255 called back at a later stage in one of the other two states.
257 The USB callback should not restart the USB transfer in case the error
258 cause is USB_ERR_CANCELLED.
260 The USB callback is protected from recursion.
262 That means one can start and stop whatever transfer from the callback
263 of another transfer one desires.
265 Also the transfer that is currently called back.
267 Recursion is handled like this that when the callback that wants to
268 recurse returns it is called one more time.
273 .Fn usbd_transfer_submit
274 This function should only be called from within the USB callback and
275 is used to start the USB hardware.
277 An USB transfer can have multiple frames consisting of one or more USB
278 packets making up an I/O vector for all USB transfer types.
280 .Bd -literal -offset indent
282 usb_default_callback(struct usb_xfer *xfer, usb_error_t error)
286 usbd_xfer_status(xfer, &actlen, NULL, NULL, NULL);
288 switch (USB_GET_STATE(xfer)) {
291 * Setup xfer frame lengths/count and data
293 usbd_transfer_submit(xfer);
296 case USB_ST_TRANSFERRED:
298 * Read usb frame data, if any.
299 * "actlen" has the total length for all frames
306 * Print error message and clear stall
312 * Here it is safe to do something without the private
319 .Sh USB CONTROL TRANSFERS
320 An USB control transfer has three parts.
322 First the SETUP packet, then DATA packet(s) and then a STATUS
325 The SETUP packet is always pointed to by frame 0 and the
327 .Fn usbd_xfer_frame_len
328 also if there should not be
329 sent any SETUP packet! If an USB control transfer has no DATA stage,
330 then the number of frames should be set to 1.
332 Else the default number of frames is 2.
334 .Bd -literal -offset indent
336 Example1: SETUP + STATUS
337 usbd_xfer_set_frames(xfer, 1);
338 usbd_xfer_set_frame_len(xfer, 0, 8);
339 usbd_transfer_submit(xfer);
341 Example2: SETUP + DATA + STATUS
342 usbd_xfer_set_frames(xfer, 2);
343 usbd_xfer_set_frame_len(xfer, 0, 8);
344 usbd_xfer_set_frame_len(xfer, 1, 1);
345 usbd_transfer_submit(xfer);
347 Example3: SETUP + DATA + STATUS - split
349 usbd_xfer_set_frames(xfer, 1);
350 usbd_xfer_set_frame_len(xfer, 0, 8);
351 usbd_transfer_submit(xfer);
354 /* IMPORTANT: frbuffers[0] must still point at the setup packet! */
355 usbd_xfer_set_frames(xfer, 2);
356 usbd_xfer_set_frame_len(xfer, 0, 0);
357 usbd_xfer_set_frame_len(xfer, 1, 1);
358 usbd_transfer_submit(xfer);
360 Example4: SETUP + STATUS - split
362 usbd_xfer_set_frames(xfer, 1);
363 usbd_xfer_set_frame_len(xfer, 0, 8);
364 usbd_xfer_set_flag(xfer, USB_MANUAL_STATUS);
365 usbd_transfer_submit(xfer);
368 usbd_xfer_set_frames(xfer, 1);
369 usbd_xfer_set_frame_len(xfer, 0, 0);
370 usbd_xfer_clr_flag(xfer, USB_MANUAL_STATUS);
371 usbd_transfer_submit(xfer);
374 .Sh USB TRANSFER CONFIG
375 To simply the search for endpoints the
377 module defines a USB config structure where it is possible to specify
378 the characteristics of the wanted endpoint.
379 .Bd -literal -offset indent
397 field selects the USB pipe type.
399 Valid values are: UE_INTERRUPT, UE_CONTROL, UE_BULK,
402 The special value UE_BULK_INTR will select BULK and INTERRUPT pipes.
404 This field is mandatory.
408 field selects the USB endpoint number.
410 A value of 0xFF, "-1" or "UE_ADDR_ANY" will select the first matching
413 This field is mandatory.
417 field selects the USB endpoint direction.
419 A value of "UE_DIR_ANY" will select the first matching endpoint.
421 Else valid values are: "UE_DIR_IN" and "UE_DIR_OUT".
423 "UE_DIR_IN" and "UE_DIR_OUT" can be binary OR'ed by "UE_DIR_SID" which
424 means that the direction will be swapped in case of
427 Note that "UE_DIR_IN" refers to the data transfer direction of the
428 "IN" tokens and "UE_DIR_OUT" refers to the data transfer direction of
431 This field is mandatory.
435 field selects the interrupt interval.
437 The value of this field is given in milliseconds and is independent of
440 Depending on the endpoint type, this field has different meaning:
441 .Bl -tag -width "UE_ISOCHRONOUS"
443 "0" use the default interrupt interval based on endpoint descriptor.
444 "Else" use the given value for polling rate.
447 "Else" the value is ignored.
450 "0" no transfer pre-delay.
451 "Else" a delay as given by this field in
452 milliseconds is inserted before the hardware is started when
453 "usbd_transfer_submit()" is called.
455 NOTE: The transfer timeout, if any, is started after that the
456 pre-delay has elapsed!
461 field, if non-zero, will set the transfer timeout in milliseconds.
462 If the "timeout" field is zero and the transfer type is ISOCHRONOUS a
463 timeout of 250ms will be used.
467 field sets the maximum number of frames.
468 If zero is specified it will yield the following results:
469 .Bl -tag -width "UE_INTERRUPT"
483 field allows you to give a number, in case more endpoints match the
484 description, that selects which matching "ep_index" should be used.
488 field allows you to select which of the interface numbers in the
489 "ifaces" array parameter passed to "usbd_transfer_setup" that should
490 be used when setting up the given USB transfer.
494 field has type "struct usb_xfer_flags" and allows one to set initial
495 flags an USB transfer.
497 .Bl -tag -width "force_short_xfer"
499 This flag forces the last transmitted USB packet to be short.
500 A short packet has a length of less than "xfer->max_packet_size", which
501 derives from "wMaxPacketSize".
502 This flag can be changed during operation.
504 This flag allows the received transfer length, "xfer->actlen" to be
505 less than "xfer->sumlen" upon completion of a transfer.
506 This flag can be changed during operation.
508 This flag allows the reception of multiple short USB frames.
509 This flag only has effect for BULK and INTERRUPT endpoints
510 and if the number of frames received is greater than 1.
511 This flag can be changed during operation.
513 This flag causes a failing USB transfer to remain first in the PIPE
514 queue except in the case of "xfer->error" equal to
516 No other USB transfers in the affected PIPE queue
517 will be started until either:
520 The failing USB transfer is stopped using "usbd_transfer_stop()".
522 The failing USB transfer performs a successful transfer.
524 The purpose of this flag is to avoid races when multiple transfers are
525 queued for execution on an USB endpoint, and the first executing
526 transfer fails leading to the need for clearing of stall for
529 In this case this flag is used to prevent the following USB transfers
530 from being executed at the same time the clear-stall command is
531 executed on the USB control endpoint.
533 This flag can be changed during operation.
535 "BOF" is short for "Block On Failure".
537 NOTE: This flag should be set on all BULK and INTERRUPT USB transfers
538 which use an endpoint that can be shared between userland and kernel.
542 Setting this flag will cause that the total buffer size will be
543 rounded up to the nearest atomic hardware transfer size.
545 The maximum data length of any USB transfer is always stored in the
546 "xfer->max_data_length".
548 For control transfers the USB kernel will allocate additional space
549 for the 8-bytes of SETUP header.
551 These 8-bytes are not counted by the "xfer->max_data_length"
554 This flag can not be changed during operation.
558 Setting this flag will cause that no data buffer will be
561 Instead the USB client must supply a data buffer.
563 This flag can not be changed during operation.
567 Setting this flag prevents an USB STATUS stage to be appended to the
568 end of the USB control transfer.
570 If no control data is transferred this flag must be cleared.
572 Else an error will be returned to the USB callback.
574 This flag is mostly useful for the USB device side.
576 This flag can be changed during operation.
580 Setting this flag causes the USB_ERR_NO_PIPE error to be ignored.
581 This flag can not be changed during operation.
585 .Bl -tag -width "Device Side Mode"
587 Setting this flag will cause STALL pids to be sent to the endpoint
588 belonging to this transfer before the transfer is started.
590 The transfer is started at the moment the host issues a clear-stall
591 command on the STALL'ed endpoint.
593 This flag can be changed during operation.
595 Setting this flag will cause a clear-stall control request to be
596 executed on the endpoint before the USB transfer is started.
599 If this flag is changed outside the USB callback function you have to
600 use the "usbd_xfer_set_stall()" and "usbd_transfer_clear_stall()"
601 functions! This flag is automatically cleared after that the stall or
602 clear stall has been executed.
605 If this flag is set the number of frames specified is assumed to give the buffering time in milliseconds instead of frames.
606 During transfer setup the frames field is pre scaled with the corresponding value for the endpoint and rounded to the nearest number of frames greater than zero.
607 This option only has effect for ISOCHRONOUS transfers.
611 field sets the total buffer size in bytes.
613 If this field is zero, "wMaxPacketSize" will be used, multiplied by
614 the "frames" field if the transfer type is ISOCHRONOUS.
616 This is useful for setting up interrupt pipes.
618 This field is mandatory.
620 NOTE: For control transfers "bufsize" includes the length of the
625 pointer sets the USB callback.
626 This field is mandatory.
629 .Sh USB LINUX COMPAT LAYER
632 module supports the Linux USB API.
643 module complies with the USB 2.0 standard.
647 module has been inspired by the
649 USB stack initially written by Lennart Augustsson.
652 module was written by
653 .An Hans Petter Selasky Aq Mt hselasky@FreeBSD.org .