1.\" 2.\" Copyright (c) 2005 Ian Dowse <iedowse@FreeBSD.org> 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 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. 13.\" 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 22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24.\" SUCH DAMAGE. 25.\" 26.\" $FreeBSD$ 27.Dd June 24, 2009 28.Dt USBDI 9 29.Os 30.Sh NAME 31.Nm usb_fifo_alloc_buffer , 32.Nm usb_fifo_attach , 33.Nm usb_fifo_detach , 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 , 44.Nm usb_fifo_reset , 45.Nm usb_fifo_softc , 46.Nm usb_fifo_wakeup , 47.Nm usbd_do_request , 48.Nm usbd_do_request_flags , 49.Nm usbd_errstr , 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 , 79.Nm usbd_xfer_softc , 80.Nm usbd_xfer_state , 81.Nm usbd_xfer_status 82.Nd Universal Serial Bus driver programming interface 83.Sh SYNOPSIS 84.In dev/usb/usb.h 85.In dev/usb/usbdi.h 86.In dev/usb/usbdi_util.h 87.Sh DESCRIPTION 88The Universal Serial Bus (USB) driver programming interface provides 89USB peripheral drivers with a host controller independent API for 90controlling and communicating with USB peripherals. 91The 92.Nm usb 93module supports both USB Host and USB Device side mode. 94. 95.Sh USB KERNEL PROGRAMMING 96Here is a list of commonly used functions: 97.Pp 98. 99.Ft "usb_error_t" 100.Fo "usbd_transfer_setup" 101.Fa "udev" 102.Fa "ifaces" 103.Fa "pxfer" 104.Fa "setup_start" 105.Fa "n_setup" 106.Fa "priv_sc" 107.Fa "priv_mtx" 108.Fc 109. 110.Pp 111. 112.Ft "void" 113.Fo "usbd_transfer_unsetup" 114.Fa "pxfer" 115.Fa "n_setup" 116.Fc 117. 118.Pp 119. 120.Ft "void" 121.Fo "usbd_transfer_start" 122.Fa "xfer" 123.Fc 124. 125.Pp 126. 127.Ft "void" 128.Fo "usbd_transfer_stop" 129.Fa "xfer" 130.Fc 131. 132.Pp 133. 134.Ft "void" 135.Fo "usbd_transfer_drain" 136.Fa "xfer" 137.Fc 138. 139. 140. 141.Sh USB TRANSFER MANAGEMENT FUNCTIONS 142The USB standard defines four types of USB transfers. 143. 144Control transfers, Bulk transfers, Interrupt transfers and Isochronous 145transfers. 146. 147All the transfer types are managed using the following five functions: 148. 149.Pp 150. 151.Fn usbd_transfer_setup 152This function will allocate memory for and initialise an array of USB 153transfers and all required DMA memory. 154. 155This function can sleep or block waiting for resources to become 156available. 157.Fa udev 158is a pointer to "struct usb_device". 159.Fa ifaces 160is an array of interface index numbers to use. 161See "if_index". 162.Fa pxfer 163is a pointer to an array of USB transfer pointers that are initialized 164to NULL, and then pointed to allocated USB transfers. 165.Fa setup_start 166is a pointer to an array of USB config structures. 167.Fa n_setup 168is a number telling the USB system how many USB transfers should be 169setup. 170.Fa priv_sc 171is the private softc pointer, which will be used to initialize 172"xfer->priv_sc". 173.Fa priv_mtx 174is the private mutex protecting the transfer structure and the 175softc. 176This pointer is used to initialize "xfer->priv_mtx". 177This function returns zero upon success. 178A non-zero return value indicates failure. 179. 180.Pp 181. 182.Fn usbd_transfer_unsetup 183This function will release the given USB transfers and all allocated 184resources associated with these USB transfers. 185.Fa pxfer 186is a pointer to an array of USB transfer pointers, that may be NULL, 187that should be freed by the USB system. 188.Fa n_setup 189is a number telling the USB system how many USB transfers should be 190unsetup. 191. 192This function can sleep waiting for USB transfers to complete. 193. 194This function is NULL safe with regard to the USB transfer structure 195pointer. 196. 197It is not allowed to call this function from the USB transfer 198callback. 199. 200.Pp 201. 202.Fn usbd_transfer_start 203This function will start the USB transfer pointed to by 204.Fa xfer , 205if not already started. 206. 207This function is always non-blocking and must be called with the 208so-called private USB mutex locked. 209. 210This function is NULL safe with regard to the USB transfer structure 211pointer. 212. 213.Pp 214. 215.Fn usbd_transfer_stop 216This function will stop the USB transfer pointed to by 217.Fa xfer , 218if not already stopped. 219. 220This function is always non-blocking and must be called with the 221so-called private USB mutex locked. 222. 223This function can return before the USB callback has been called. 224. 225This function is NULL safe with regard to the USB transfer structure 226pointer. 227. 228If the transfer was in progress, the callback will called with 229"USB_ST_ERROR" and "error = USB_ERR_CANCELLED". 230. 231.Pp 232. 233.Fn usbd_transfer_drain 234This function will stop an USB transfer, if not already stopped and 235wait for any additional USB hardware operations to complete. 236. 237Buffers that are loaded into DMA using "usbd_xfer_set_frame_data()" can 238safely be freed after that this function has returned. 239. 240This function can block the caller and will not return before the USB 241callback has been called. 242. 243This function is NULL safe with regard to the USB transfer structure 244pointer. 245. 246.Sh USB TRANSFER CALLBACK 247. 248The USB callback has three states. 249. 250USB_ST_SETUP, USB_ST_TRANSFERRED and USB_ST_ERROR. 251USB_ST_SETUP is the initial state. 252. 253After the callback has been called with this state it will always be 254called back at a later stage in one of the other two states. 255. 256The USB callback should not restart the USB transfer in case the error 257cause is USB_ERR_CANCELLED. 258. 259The USB callback is protected from recursion. 260. 261That means one can start and stop whatever transfer from the callback 262of another transfer one desires. 263. 264Also the transfer that is currently called back. 265. 266Recursion is handled like this that when the callback that wants to 267recurse returns it is called one more time. 268. 269. 270.Pp 271. 272.Fn usbd_transfer_submit 273This function should only be called from within the USB callback and 274is used to start the USB hardware. 275. 276An USB transfer can have multiple frames consisting of one or more USB 277packets making up an I/O vector for all USB transfer types. 278. 279.Bd -literal -offset indent 280void 281usb_default_callback(struct usb_xfer *xfer, usb_error_t error) 282{ 283 int actlen; 284 285 usbd_xfer_status(xfer, &actlen, NULL, NULL, NULL); 286 287 switch (USB_GET_STATE(xfer)) { 288 case USB_ST_SETUP: 289 /* 290 * Setup xfer frame lengths/count and data 291 */ 292 usbd_transfer_submit(xfer); 293 break; 294 295 case USB_ST_TRANSFERRED: 296 /* 297 * Read usb frame data, if any. 298 * "actlen" has the total length for all frames 299 * transferred. 300 */ 301 break; 302 303 default: /* Error */ 304 /* 305 * Print error message and clear stall 306 * for example. 307 */ 308 break; 309 } 310 /* 311 * Here it is safe to do something without the private 312 * USB mutex locked. 313 */ 314 return; 315} 316.Ed 317. 318.Sh USB CONTROL TRANSFERS 319An USB control transfer has three parts. 320. 321First the SETUP packet, then DATA packet(s) and then a STATUS 322packet. 323. 324The SETUP packet is always pointed to by frame 0 and the 325length is set by 326.Fn usbd_xfer_frame_len 327also if there should not be 328sent any SETUP packet! 329If an USB control transfer has no DATA stage, 330then the number of frames should be set to 1. 331. 332Else the default number of frames is 2. 333. 334.Bd -literal -offset indent 335 336Example1: SETUP + STATUS 337 usbd_xfer_set_frames(xfer, 1); 338 usbd_xfer_set_frame_len(xfer, 0, 8); 339 usbd_transfer_submit(xfer); 340 341Example2: 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); 346 347Example3: SETUP + DATA + STATUS - split 3481st callback: 349 usbd_xfer_set_frames(xfer, 1); 350 usbd_xfer_set_frame_len(xfer, 0, 8); 351 usbd_transfer_submit(xfer); 352 3532nd callback: 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); 359 360Example4: SETUP + STATUS - split 3611st callback: 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); 366 3672nd callback: 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); 372 373.Ed 374.Sh USB TRANSFER CONFIG 375To simply the search for endpoints the 376.Nm usb 377module defines a USB config structure where it is possible to specify 378the characteristics of the wanted endpoint. 379.Bd -literal -offset indent 380 381struct usb_config { 382 bufsize, 383 callback 384 direction, 385 endpoint, 386 frames, 387 index flags, 388 interval, 389 timeout, 390 type, 391}; 392 393.Ed 394. 395.Pp 396.Fa type 397field selects the USB pipe type. 398. 399Valid values are: UE_INTERRUPT, UE_CONTROL, UE_BULK, 400UE_ISOCHRONOUS. 401. 402The special value UE_BULK_INTR will select BULK and INTERRUPT pipes. 403. 404This field is mandatory. 405. 406.Pp 407.Fa endpoint 408field selects the USB endpoint number. 409. 410A value of 0xFF, "-1" or "UE_ADDR_ANY" will select the first matching 411endpoint. 412. 413This field is mandatory. 414. 415.Pp 416.Fa direction 417field selects the USB endpoint direction. 418. 419A value of "UE_DIR_ANY" will select the first matching endpoint. 420. 421Else valid values are: "UE_DIR_IN" and "UE_DIR_OUT". 422. 423"UE_DIR_IN" and "UE_DIR_OUT" can be binary OR'ed by "UE_DIR_SID" which 424means that the direction will be swapped in case of 425USB_MODE_DEVICE. 426. 427Note 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 429the "OUT" tokens. 430. 431This field is mandatory. 432. 433.Pp 434.Fa interval 435field selects the interrupt interval. 436. 437The value of this field is given in milliseconds and is independent of 438device speed. 439. 440Depending on the endpoint type, this field has different meaning: 441.Bl -tag -width "UE_ISOCHRONOUS" 442.It UE_INTERRUPT 443"0" use the default interrupt interval based on endpoint descriptor. 444"Else" use the given value for polling rate. 445.It UE_ISOCHRONOUS 446"0" use default. 447"Else" the value is ignored. 448.It UE_BULK 449.It UE_CONTROL 450"0" no transfer pre-delay. 451"Else" a delay as given by this field in 452milliseconds is inserted before the hardware is started when 453"usbd_transfer_submit()" is called. 454.Pp 455NOTE: The transfer timeout, if any, is started after that the 456pre-delay has elapsed! 457.El 458. 459.Pp 460.Fa timeout 461field, if non-zero, will set the transfer timeout in milliseconds. 462If the "timeout" field is zero and the transfer type is ISOCHRONOUS a 463timeout of 250ms will be used. 464. 465.Pp 466.Fa frames 467field sets the maximum number of frames. 468If zero is specified it will yield the following results: 469.Bl -tag -width "UE_INTERRUPT" 470.It UE_BULK 471xfer->nframes = 1; 472.It UE_INTERRUPT 473xfer->nframes = 1; 474.It UE_CONTROL 475xfer->nframes = 2; 476.It UE_ISOCHRONOUS 477Not allowed. 478Will cause an error. 479.El 480. 481.Pp 482.Fa ep_index 483field allows you to give a number, in case more endpoints match the 484description, that selects which matching "ep_index" should be used. 485. 486.Pp 487.Fa if_index 488field allows you to select which of the interface numbers in the 489"ifaces" array parameter passed to "usbd_transfer_setup" that should 490be used when setting up the given USB transfer. 491. 492.Pp 493.Fa flags 494field has type "struct usb_xfer_flags" and allows one to set initial 495flags an USB transfer. 496Valid flags are: 497.Bl -tag -width "force_short_xfer" 498.It force_short_xfer 499This flag forces the last transmitted USB packet to be short. 500A short packet has a length of less than "xfer->max_packet_size", which 501derives from "wMaxPacketSize". 502This flag can be changed during operation. 503.It short_xfer_ok 504This flag allows the received transfer length, "xfer->actlen" to be 505less than "xfer->sumlen" upon completion of a transfer. 506This flag can be changed during operation. 507.It short_frames_ok 508This flag allows the reception of multiple short USB frames. 509This flag 510only has effect for BULK and INTERRUPT endpoints and if the number of 511frames received is greater than 1. 512This flag can be changed during operation. 513.It pipe_bof 514This flag causes a failing USB transfer to remain first in the PIPE 515queue except in the case of "xfer->error" equal to 516"USB_ERR_CANCELLED". 517No other USB transfers in the affected PIPE queue 518will be started until either: 519.Bl -tag -width "X" 520.It 1 521The failing USB transfer is stopped using "usbd_transfer_stop()". 522.It 2 523The failing USB transfer performs a successful transfer. 524.El 525The purpose of this flag is to avoid races when multiple transfers are 526queued for execution on an USB endpoint, and the first executing 527transfer fails leading to the need for clearing of stall for 528example. 529. 530In this case this flag is used to prevent the following USB transfers 531from being executed at the same time the clear-stall command is 532executed on the USB control endpoint. 533. 534This flag can be changed during operation. 535.Pp 536"BOF" is short for "Block On Failure". 537.Pp 538NOTE: This flag should be set on all BULK and INTERRUPT USB transfers 539which use an endpoint that can be shared between userland and kernel. 540. 541. 542.It proxy_buffer 543Setting this flag will cause that the total buffer size will be 544rounded up to the nearest atomic hardware transfer size. 545. 546The maximum data length of any USB transfer is always stored in the 547"xfer->max_data_length". 548. 549For control transfers the USB kernel will allocate additional space 550for the 8-bytes of SETUP header. 551. 552These 8-bytes are not counted by the "xfer->max_data_length" 553variable. 554. 555This flag can not be changed during operation. 556. 557. 558.It ext_buffer 559Setting this flag will cause that no data buffer will be 560allocated. 561. 562Instead the USB client must supply a data buffer. 563. 564This flag can not be changed during operation. 565. 566. 567.It manual_status 568Setting this flag prevents an USB STATUS stage to be appended to the 569end of the USB control transfer. 570. 571If no control data is transferred this flag must be cleared. 572. 573Else an error will be returned to the USB callback. 574. 575This flag is mostly useful for the USB device side. 576. 577This flag can be changed during operation. 578. 579. 580.It no_pipe_ok 581Setting this flag causes the USB_ERR_NO_PIPE error to be ignored. 582This flag can not be changed during operation. 583. 584. 585.It stall_pipe 586.Bl -tag -width "Device Side Mode" 587.It Device Side Mode 588Setting this flag will cause STALL pids to be sent to the endpoint 589belonging to this transfer before the transfer is started. 590. 591The transfer is started at the moment the host issues a clear-stall 592command on the STALL'ed endpoint. 593. 594This flag can be changed during operation. 595.It Host Side Mode 596Setting this flag will cause a clear-stall control request to be 597executed on the endpoint before the USB transfer is started. 598.El 599.Pp 600If this flag is changed outside the USB callback function you have to 601use the "usbd_xfer_set_stall()" and "usbd_transfer_clear_stall()" 602functions! This flag is automatically cleared after that the stall or 603clear stall has been executed. 604. 605.It pre_scale_frames 606If this flag is set the number of frames specified is assumed to give the buffering time in milliseconds instead of frames. 607During 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. 608This option only has effect for ISOCHRONOUS transfers. 609.El 610.Pp 611.Fa bufsize 612field sets the total buffer size in bytes. 613. 614If this field is zero, "wMaxPacketSize" will be used, multiplied by 615the "frames" field if the transfer type is ISOCHRONOUS. 616. 617This is useful for setting up interrupt pipes. 618. 619This field is mandatory. 620.Pp 621NOTE: For control transfers "bufsize" includes the length of the 622request structure. 623. 624.Pp 625.Fa callback 626pointer sets the USB callback. 627This field is mandatory. 628. 629. 630.Sh USB LINUX COMPAT LAYER 631The 632.Nm usb 633module supports the Linux USB API. 634. 635. 636.Sh SEE ALSO 637.Xr libusb 3 , 638.Xr usb 4 , 639.Xr usbconfig 8 640.Sh STANDARDS 641The 642.Nm usb 643module complies with the USB 2.0 standard. 644.Sh HISTORY 645The 646.Nm usb 647module has been inspired by the NetBSD USB stack initially written by 648Lennart Augustsson. 649The 650.Nm usb 651module was written by 652.An Hans Petter Selasky Aq Mt hselasky@FreeBSD.org . 653