1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * uvc_video.c -- USB Video Class driver - Video handling 4 * 5 * Copyright (C) 2005-2010 6 * Laurent Pinchart (laurent.pinchart@ideasonboard.com) 7 */ 8 9#include <linux/dma-mapping.h> 10#include <linux/highmem.h> 11#include <linux/kernel.h> 12#include <linux/list.h> 13#include <linux/module.h> 14#include <linux/slab.h> 15#include <linux/usb.h> 16#include <linux/usb/hcd.h> 17#include <linux/videodev2.h> 18#include <linux/vmalloc.h> 19#include <linux/wait.h> 20#include <linux/atomic.h> 21#include <asm/unaligned.h> 22 23#include <media/v4l2-common.h> 24 25#include "uvcvideo.h" 26 27/* ------------------------------------------------------------------------ 28 * UVC Controls 29 */ 30 31static int __uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit, 32 u8 intfnum, u8 cs, void *data, u16 size, 33 int timeout) 34{ 35 u8 type = USB_TYPE_CLASS | USB_RECIP_INTERFACE; 36 unsigned int pipe; 37 38 pipe = (query & 0x80) ? usb_rcvctrlpipe(dev->udev, 0) 39 : usb_sndctrlpipe(dev->udev, 0); 40 type |= (query & 0x80) ? USB_DIR_IN : USB_DIR_OUT; 41 42 return usb_control_msg(dev->udev, pipe, query, type, cs << 8, 43 unit << 8 | intfnum, data, size, timeout); 44} 45 46static const char *uvc_query_name(u8 query) 47{ 48 switch (query) { 49 case UVC_SET_CUR: 50 return "SET_CUR"; 51 case UVC_GET_CUR: 52 return "GET_CUR"; 53 case UVC_GET_MIN: 54 return "GET_MIN"; 55 case UVC_GET_MAX: 56 return "GET_MAX"; 57 case UVC_GET_RES: 58 return "GET_RES"; 59 case UVC_GET_LEN: 60 return "GET_LEN"; 61 case UVC_GET_INFO: 62 return "GET_INFO"; 63 case UVC_GET_DEF: 64 return "GET_DEF"; 65 default: 66 return "<invalid>"; 67 } 68} 69 70int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit, 71 u8 intfnum, u8 cs, void *data, u16 size) 72{ 73 int ret; 74 u8 error; 75 u8 tmp; 76 77 ret = __uvc_query_ctrl(dev, query, unit, intfnum, cs, data, size, 78 UVC_CTRL_CONTROL_TIMEOUT); 79 if (likely(ret == size)) 80 return 0; 81 82 if (ret != -EPIPE) { 83 dev_err(&dev->udev->dev, 84 "Failed to query (%s) UVC control %u on unit %u: %d (exp. %u).\n", 85 uvc_query_name(query), cs, unit, ret, size); 86 return ret < 0 ? ret : -EPIPE; 87 } 88 89 /* Reuse data[0] to request the error code. */ 90 tmp = *(u8 *)data; 91 92 ret = __uvc_query_ctrl(dev, UVC_GET_CUR, 0, intfnum, 93 UVC_VC_REQUEST_ERROR_CODE_CONTROL, data, 1, 94 UVC_CTRL_CONTROL_TIMEOUT); 95 96 error = *(u8 *)data; 97 *(u8 *)data = tmp; 98 99 if (ret != 1) 100 return ret < 0 ? ret : -EPIPE; 101 102 uvc_dbg(dev, CONTROL, "Control error %u\n", error); 103 104 switch (error) { 105 case 0: 106 /* Cannot happen - we received a STALL */ 107 return -EPIPE; 108 case 1: /* Not ready */ 109 return -EBUSY; 110 case 2: /* Wrong state */ 111 return -EACCES; 112 case 3: /* Power */ 113 return -EREMOTE; 114 case 4: /* Out of range */ 115 return -ERANGE; 116 case 5: /* Invalid unit */ 117 case 6: /* Invalid control */ 118 case 7: /* Invalid Request */ 119 /* 120 * The firmware has not properly implemented 121 * the control or there has been a HW error. 122 */ 123 return -EIO; 124 case 8: /* Invalid value within range */ 125 return -EINVAL; 126 default: /* reserved or unknown */ 127 break; 128 } 129 130 return -EPIPE; 131} 132 133static const struct usb_device_id elgato_cam_link_4k = { 134 USB_DEVICE(0x0fd9, 0x0066) 135}; 136 137static void uvc_fixup_video_ctrl(struct uvc_streaming *stream, 138 struct uvc_streaming_control *ctrl) 139{ 140 const struct uvc_format *format = NULL; 141 const struct uvc_frame *frame = NULL; 142 unsigned int i; 143 144 /* 145 * The response of the Elgato Cam Link 4K is incorrect: The second byte 146 * contains bFormatIndex (instead of being the second byte of bmHint). 147 * The first byte is always zero. The third byte is always 1. 148 * 149 * The UVC 1.5 class specification defines the first five bits in the 150 * bmHint bitfield. The remaining bits are reserved and should be zero. 151 * Therefore a valid bmHint will be less than 32. 152 * 153 * Latest Elgato Cam Link 4K firmware as of 2021-03-23 needs this fix. 154 * MCU: 20.02.19, FPGA: 67 155 */ 156 if (usb_match_one_id(stream->dev->intf, &elgato_cam_link_4k) && 157 ctrl->bmHint > 255) { 158 u8 corrected_format_index = ctrl->bmHint >> 8; 159 160 uvc_dbg(stream->dev, VIDEO, 161 "Correct USB video probe response from {bmHint: 0x%04x, bFormatIndex: %u} to {bmHint: 0x%04x, bFormatIndex: %u}\n", 162 ctrl->bmHint, ctrl->bFormatIndex, 163 1, corrected_format_index); 164 ctrl->bmHint = 1; 165 ctrl->bFormatIndex = corrected_format_index; 166 } 167 168 for (i = 0; i < stream->nformats; ++i) { 169 if (stream->formats[i].index == ctrl->bFormatIndex) { 170 format = &stream->formats[i]; 171 break; 172 } 173 } 174 175 if (format == NULL) 176 return; 177 178 for (i = 0; i < format->nframes; ++i) { 179 if (format->frames[i].bFrameIndex == ctrl->bFrameIndex) { 180 frame = &format->frames[i]; 181 break; 182 } 183 } 184 185 if (frame == NULL) 186 return; 187 188 if (!(format->flags & UVC_FMT_FLAG_COMPRESSED) || 189 (ctrl->dwMaxVideoFrameSize == 0 && 190 stream->dev->uvc_version < 0x0110)) 191 ctrl->dwMaxVideoFrameSize = 192 frame->dwMaxVideoFrameBufferSize; 193 194 /* 195 * The "TOSHIBA Web Camera - 5M" Chicony device (04f2:b50b) seems to 196 * compute the bandwidth on 16 bits and erroneously sign-extend it to 197 * 32 bits, resulting in a huge bandwidth value. Detect and fix that 198 * condition by setting the 16 MSBs to 0 when they're all equal to 1. 199 */ 200 if ((ctrl->dwMaxPayloadTransferSize & 0xffff0000) == 0xffff0000) 201 ctrl->dwMaxPayloadTransferSize &= ~0xffff0000; 202 203 if (!(format->flags & UVC_FMT_FLAG_COMPRESSED) && 204 stream->dev->quirks & UVC_QUIRK_FIX_BANDWIDTH && 205 stream->intf->num_altsetting > 1) { 206 u32 interval; 207 u32 bandwidth; 208 209 interval = (ctrl->dwFrameInterval > 100000) 210 ? ctrl->dwFrameInterval 211 : frame->dwFrameInterval[0]; 212 213 /* 214 * Compute a bandwidth estimation by multiplying the frame 215 * size by the number of video frames per second, divide the 216 * result by the number of USB frames (or micro-frames for 217 * high-speed devices) per second and add the UVC header size 218 * (assumed to be 12 bytes long). 219 */ 220 bandwidth = frame->wWidth * frame->wHeight / 8 * format->bpp; 221 bandwidth *= 10000000 / interval + 1; 222 bandwidth /= 1000; 223 if (stream->dev->udev->speed == USB_SPEED_HIGH) 224 bandwidth /= 8; 225 bandwidth += 12; 226 227 /* 228 * The bandwidth estimate is too low for many cameras. Don't use 229 * maximum packet sizes lower than 1024 bytes to try and work 230 * around the problem. According to measurements done on two 231 * different camera models, the value is high enough to get most 232 * resolutions working while not preventing two simultaneous 233 * VGA streams at 15 fps. 234 */ 235 bandwidth = max_t(u32, bandwidth, 1024); 236 237 ctrl->dwMaxPayloadTransferSize = bandwidth; 238 } 239} 240 241static size_t uvc_video_ctrl_size(struct uvc_streaming *stream) 242{ 243 /* 244 * Return the size of the video probe and commit controls, which depends 245 * on the protocol version. 246 */ 247 if (stream->dev->uvc_version < 0x0110) 248 return 26; 249 else if (stream->dev->uvc_version < 0x0150) 250 return 34; 251 else 252 return 48; 253} 254 255static int uvc_get_video_ctrl(struct uvc_streaming *stream, 256 struct uvc_streaming_control *ctrl, int probe, u8 query) 257{ 258 u16 size = uvc_video_ctrl_size(stream); 259 u8 *data; 260 int ret; 261 262 if ((stream->dev->quirks & UVC_QUIRK_PROBE_DEF) && 263 query == UVC_GET_DEF) 264 return -EIO; 265 266 data = kmalloc(size, GFP_KERNEL); 267 if (data == NULL) 268 return -ENOMEM; 269 270 ret = __uvc_query_ctrl(stream->dev, query, 0, stream->intfnum, 271 probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data, 272 size, uvc_timeout_param); 273 274 if ((query == UVC_GET_MIN || query == UVC_GET_MAX) && ret == 2) { 275 /* 276 * Some cameras, mostly based on Bison Electronics chipsets, 277 * answer a GET_MIN or GET_MAX request with the wCompQuality 278 * field only. 279 */ 280 uvc_warn_once(stream->dev, UVC_WARN_MINMAX, "UVC non " 281 "compliance - GET_MIN/MAX(PROBE) incorrectly " 282 "supported. Enabling workaround.\n"); 283 memset(ctrl, 0, sizeof(*ctrl)); 284 ctrl->wCompQuality = le16_to_cpup((__le16 *)data); 285 ret = 0; 286 goto out; 287 } else if (query == UVC_GET_DEF && probe == 1 && ret != size) { 288 /* 289 * Many cameras don't support the GET_DEF request on their 290 * video probe control. Warn once and return, the caller will 291 * fall back to GET_CUR. 292 */ 293 uvc_warn_once(stream->dev, UVC_WARN_PROBE_DEF, "UVC non " 294 "compliance - GET_DEF(PROBE) not supported. " 295 "Enabling workaround.\n"); 296 ret = -EIO; 297 goto out; 298 } else if (ret != size) { 299 dev_err(&stream->intf->dev, 300 "Failed to query (%u) UVC %s control : %d (exp. %u).\n", 301 query, probe ? "probe" : "commit", ret, size); 302 ret = (ret == -EPROTO) ? -EPROTO : -EIO; 303 goto out; 304 } 305 306 ctrl->bmHint = le16_to_cpup((__le16 *)&data[0]); 307 ctrl->bFormatIndex = data[2]; 308 ctrl->bFrameIndex = data[3]; 309 ctrl->dwFrameInterval = le32_to_cpup((__le32 *)&data[4]); 310 ctrl->wKeyFrameRate = le16_to_cpup((__le16 *)&data[8]); 311 ctrl->wPFrameRate = le16_to_cpup((__le16 *)&data[10]); 312 ctrl->wCompQuality = le16_to_cpup((__le16 *)&data[12]); 313 ctrl->wCompWindowSize = le16_to_cpup((__le16 *)&data[14]); 314 ctrl->wDelay = le16_to_cpup((__le16 *)&data[16]); 315 ctrl->dwMaxVideoFrameSize = get_unaligned_le32(&data[18]); 316 ctrl->dwMaxPayloadTransferSize = get_unaligned_le32(&data[22]); 317 318 if (size >= 34) { 319 ctrl->dwClockFrequency = get_unaligned_le32(&data[26]); 320 ctrl->bmFramingInfo = data[30]; 321 ctrl->bPreferedVersion = data[31]; 322 ctrl->bMinVersion = data[32]; 323 ctrl->bMaxVersion = data[33]; 324 } else { 325 ctrl->dwClockFrequency = stream->dev->clock_frequency; 326 ctrl->bmFramingInfo = 0; 327 ctrl->bPreferedVersion = 0; 328 ctrl->bMinVersion = 0; 329 ctrl->bMaxVersion = 0; 330 } 331 332 /* 333 * Some broken devices return null or wrong dwMaxVideoFrameSize and 334 * dwMaxPayloadTransferSize fields. Try to get the value from the 335 * format and frame descriptors. 336 */ 337 uvc_fixup_video_ctrl(stream, ctrl); 338 ret = 0; 339 340out: 341 kfree(data); 342 return ret; 343} 344 345static int uvc_set_video_ctrl(struct uvc_streaming *stream, 346 struct uvc_streaming_control *ctrl, int probe) 347{ 348 u16 size = uvc_video_ctrl_size(stream); 349 u8 *data; 350 int ret; 351 352 data = kzalloc(size, GFP_KERNEL); 353 if (data == NULL) 354 return -ENOMEM; 355 356 *(__le16 *)&data[0] = cpu_to_le16(ctrl->bmHint); 357 data[2] = ctrl->bFormatIndex; 358 data[3] = ctrl->bFrameIndex; 359 *(__le32 *)&data[4] = cpu_to_le32(ctrl->dwFrameInterval); 360 *(__le16 *)&data[8] = cpu_to_le16(ctrl->wKeyFrameRate); 361 *(__le16 *)&data[10] = cpu_to_le16(ctrl->wPFrameRate); 362 *(__le16 *)&data[12] = cpu_to_le16(ctrl->wCompQuality); 363 *(__le16 *)&data[14] = cpu_to_le16(ctrl->wCompWindowSize); 364 *(__le16 *)&data[16] = cpu_to_le16(ctrl->wDelay); 365 put_unaligned_le32(ctrl->dwMaxVideoFrameSize, &data[18]); 366 put_unaligned_le32(ctrl->dwMaxPayloadTransferSize, &data[22]); 367 368 if (size >= 34) { 369 put_unaligned_le32(ctrl->dwClockFrequency, &data[26]); 370 data[30] = ctrl->bmFramingInfo; 371 data[31] = ctrl->bPreferedVersion; 372 data[32] = ctrl->bMinVersion; 373 data[33] = ctrl->bMaxVersion; 374 } 375 376 ret = __uvc_query_ctrl(stream->dev, UVC_SET_CUR, 0, stream->intfnum, 377 probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data, 378 size, uvc_timeout_param); 379 if (ret != size) { 380 dev_err(&stream->intf->dev, 381 "Failed to set UVC %s control : %d (exp. %u).\n", 382 probe ? "probe" : "commit", ret, size); 383 ret = -EIO; 384 } 385 386 kfree(data); 387 return ret; 388} 389 390int uvc_probe_video(struct uvc_streaming *stream, 391 struct uvc_streaming_control *probe) 392{ 393 struct uvc_streaming_control probe_min, probe_max; 394 unsigned int i; 395 int ret; 396 397 /* 398 * Perform probing. The device should adjust the requested values 399 * according to its capabilities. However, some devices, namely the 400 * first generation UVC Logitech webcams, don't implement the Video 401 * Probe control properly, and just return the needed bandwidth. For 402 * that reason, if the needed bandwidth exceeds the maximum available 403 * bandwidth, try to lower the quality. 404 */ 405 ret = uvc_set_video_ctrl(stream, probe, 1); 406 if (ret < 0) 407 goto done; 408 409 /* Get the minimum and maximum values for compression settings. */ 410 if (!(stream->dev->quirks & UVC_QUIRK_PROBE_MINMAX)) { 411 ret = uvc_get_video_ctrl(stream, &probe_min, 1, UVC_GET_MIN); 412 if (ret < 0) 413 goto done; 414 ret = uvc_get_video_ctrl(stream, &probe_max, 1, UVC_GET_MAX); 415 if (ret < 0) 416 goto done; 417 418 probe->wCompQuality = probe_max.wCompQuality; 419 } 420 421 for (i = 0; i < 2; ++i) { 422 ret = uvc_set_video_ctrl(stream, probe, 1); 423 if (ret < 0) 424 goto done; 425 ret = uvc_get_video_ctrl(stream, probe, 1, UVC_GET_CUR); 426 if (ret < 0) 427 goto done; 428 429 if (stream->intf->num_altsetting == 1) 430 break; 431 432 if (probe->dwMaxPayloadTransferSize <= stream->maxpsize) 433 break; 434 435 if (stream->dev->quirks & UVC_QUIRK_PROBE_MINMAX) { 436 ret = -ENOSPC; 437 goto done; 438 } 439 440 /* TODO: negotiate compression parameters */ 441 probe->wKeyFrameRate = probe_min.wKeyFrameRate; 442 probe->wPFrameRate = probe_min.wPFrameRate; 443 probe->wCompQuality = probe_max.wCompQuality; 444 probe->wCompWindowSize = probe_min.wCompWindowSize; 445 } 446 447done: 448 return ret; 449} 450 451static int uvc_commit_video(struct uvc_streaming *stream, 452 struct uvc_streaming_control *probe) 453{ 454 return uvc_set_video_ctrl(stream, probe, 0); 455} 456 457/* ----------------------------------------------------------------------------- 458 * Clocks and timestamps 459 */ 460 461static inline ktime_t uvc_video_get_time(void) 462{ 463 if (uvc_clock_param == CLOCK_MONOTONIC) 464 return ktime_get(); 465 else 466 return ktime_get_real(); 467} 468 469static void 470uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf, 471 const u8 *data, int len) 472{ 473 struct uvc_clock_sample *sample; 474 unsigned int header_size; 475 bool has_pts = false; 476 bool has_scr = false; 477 unsigned long flags; 478 ktime_t time; 479 u16 host_sof; 480 u16 dev_sof; 481 482 switch (data[1] & (UVC_STREAM_PTS | UVC_STREAM_SCR)) { 483 case UVC_STREAM_PTS | UVC_STREAM_SCR: 484 header_size = 12; 485 has_pts = true; 486 has_scr = true; 487 break; 488 case UVC_STREAM_PTS: 489 header_size = 6; 490 has_pts = true; 491 break; 492 case UVC_STREAM_SCR: 493 header_size = 8; 494 has_scr = true; 495 break; 496 default: 497 header_size = 2; 498 break; 499 } 500 501 /* Check for invalid headers. */ 502 if (len < header_size) 503 return; 504 505 /* 506 * Extract the timestamps: 507 * 508 * - store the frame PTS in the buffer structure 509 * - if the SCR field is present, retrieve the host SOF counter and 510 * kernel timestamps and store them with the SCR STC and SOF fields 511 * in the ring buffer 512 */ 513 if (has_pts && buf != NULL) 514 buf->pts = get_unaligned_le32(&data[2]); 515 516 if (!has_scr) 517 return; 518 519 /* 520 * To limit the amount of data, drop SCRs with an SOF identical to the 521 * previous one. This filtering is also needed to support UVC 1.5, where 522 * all the data packets of the same frame contains the same SOF. In that 523 * case only the first one will match the host_sof. 524 */ 525 dev_sof = get_unaligned_le16(&data[header_size - 2]); 526 if (dev_sof == stream->clock.last_sof) 527 return; 528 529 stream->clock.last_sof = dev_sof; 530 531 host_sof = usb_get_current_frame_number(stream->dev->udev); 532 time = uvc_video_get_time(); 533 534 /* 535 * The UVC specification allows device implementations that can't obtain 536 * the USB frame number to keep their own frame counters as long as they 537 * match the size and frequency of the frame number associated with USB 538 * SOF tokens. The SOF values sent by such devices differ from the USB 539 * SOF tokens by a fixed offset that needs to be estimated and accounted 540 * for to make timestamp recovery as accurate as possible. 541 * 542 * The offset is estimated the first time a device SOF value is received 543 * as the difference between the host and device SOF values. As the two 544 * SOF values can differ slightly due to transmission delays, consider 545 * that the offset is null if the difference is not higher than 10 ms 546 * (negative differences can not happen and are thus considered as an 547 * offset). The video commit control wDelay field should be used to 548 * compute a dynamic threshold instead of using a fixed 10 ms value, but 549 * devices don't report reliable wDelay values. 550 * 551 * See uvc_video_clock_host_sof() for an explanation regarding why only 552 * the 8 LSBs of the delta are kept. 553 */ 554 if (stream->clock.sof_offset == (u16)-1) { 555 u16 delta_sof = (host_sof - dev_sof) & 255; 556 if (delta_sof >= 10) 557 stream->clock.sof_offset = delta_sof; 558 else 559 stream->clock.sof_offset = 0; 560 } 561 562 dev_sof = (dev_sof + stream->clock.sof_offset) & 2047; 563 564 spin_lock_irqsave(&stream->clock.lock, flags); 565 566 sample = &stream->clock.samples[stream->clock.head]; 567 sample->dev_stc = get_unaligned_le32(&data[header_size - 6]); 568 sample->dev_sof = dev_sof; 569 sample->host_sof = host_sof; 570 sample->host_time = time; 571 572 /* Update the sliding window head and count. */ 573 stream->clock.head = (stream->clock.head + 1) % stream->clock.size; 574 575 if (stream->clock.count < stream->clock.size) 576 stream->clock.count++; 577 578 spin_unlock_irqrestore(&stream->clock.lock, flags); 579} 580 581static void uvc_video_clock_reset(struct uvc_streaming *stream) 582{ 583 struct uvc_clock *clock = &stream->clock; 584 585 clock->head = 0; 586 clock->count = 0; 587 clock->last_sof = -1; 588 clock->sof_offset = -1; 589} 590 591static int uvc_video_clock_init(struct uvc_streaming *stream) 592{ 593 struct uvc_clock *clock = &stream->clock; 594 595 spin_lock_init(&clock->lock); 596 clock->size = 32; 597 598 clock->samples = kmalloc_array(clock->size, sizeof(*clock->samples), 599 GFP_KERNEL); 600 if (clock->samples == NULL) 601 return -ENOMEM; 602 603 uvc_video_clock_reset(stream); 604 605 return 0; 606} 607 608static void uvc_video_clock_cleanup(struct uvc_streaming *stream) 609{ 610 kfree(stream->clock.samples); 611 stream->clock.samples = NULL; 612} 613 614/* 615 * uvc_video_clock_host_sof - Return the host SOF value for a clock sample 616 * 617 * Host SOF counters reported by usb_get_current_frame_number() usually don't 618 * cover the whole 11-bits SOF range (0-2047) but are limited to the HCI frame 619 * schedule window. They can be limited to 8, 9 or 10 bits depending on the host 620 * controller and its configuration. 621 * 622 * We thus need to recover the SOF value corresponding to the host frame number. 623 * As the device and host frame numbers are sampled in a short interval, the 624 * difference between their values should be equal to a small delta plus an 625 * integer multiple of 256 caused by the host frame number limited precision. 626 * 627 * To obtain the recovered host SOF value, compute the small delta by masking 628 * the high bits of the host frame counter and device SOF difference and add it 629 * to the device SOF value. 630 */ 631static u16 uvc_video_clock_host_sof(const struct uvc_clock_sample *sample) 632{ 633 /* The delta value can be negative. */ 634 s8 delta_sof; 635 636 delta_sof = (sample->host_sof - sample->dev_sof) & 255; 637 638 return (sample->dev_sof + delta_sof) & 2047; 639} 640 641/* 642 * uvc_video_clock_update - Update the buffer timestamp 643 * 644 * This function converts the buffer PTS timestamp to the host clock domain by 645 * going through the USB SOF clock domain and stores the result in the V4L2 646 * buffer timestamp field. 647 * 648 * The relationship between the device clock and the host clock isn't known. 649 * However, the device and the host share the common USB SOF clock which can be 650 * used to recover that relationship. 651 * 652 * The relationship between the device clock and the USB SOF clock is considered 653 * to be linear over the clock samples sliding window and is given by 654 * 655 * SOF = m * PTS + p 656 * 657 * Several methods to compute the slope (m) and intercept (p) can be used. As 658 * the clock drift should be small compared to the sliding window size, we 659 * assume that the line that goes through the points at both ends of the window 660 * is a good approximation. Naming those points P1 and P2, we get 661 * 662 * SOF = (SOF2 - SOF1) / (STC2 - STC1) * PTS 663 * + (SOF1 * STC2 - SOF2 * STC1) / (STC2 - STC1) 664 * 665 * or 666 * 667 * SOF = ((SOF2 - SOF1) * PTS + SOF1 * STC2 - SOF2 * STC1) / (STC2 - STC1) (1) 668 * 669 * to avoid losing precision in the division. Similarly, the host timestamp is 670 * computed with 671 * 672 * TS = ((TS2 - TS1) * SOF + TS1 * SOF2 - TS2 * SOF1) / (SOF2 - SOF1) (2) 673 * 674 * SOF values are coded on 11 bits by USB. We extend their precision with 16 675 * decimal bits, leading to a 11.16 coding. 676 * 677 * TODO: To avoid surprises with device clock values, PTS/STC timestamps should 678 * be normalized using the nominal device clock frequency reported through the 679 * UVC descriptors. 680 * 681 * Both the PTS/STC and SOF counters roll over, after a fixed but device 682 * specific amount of time for PTS/STC and after 2048ms for SOF. As long as the 683 * sliding window size is smaller than the rollover period, differences computed 684 * on unsigned integers will produce the correct result. However, the p term in 685 * the linear relations will be miscomputed. 686 * 687 * To fix the issue, we subtract a constant from the PTS and STC values to bring 688 * PTS to half the 32 bit STC range. The sliding window STC values then fit into 689 * the 32 bit range without any rollover. 690 * 691 * Similarly, we add 2048 to the device SOF values to make sure that the SOF 692 * computed by (1) will never be smaller than 0. This offset is then compensated 693 * by adding 2048 to the SOF values used in (2). However, this doesn't prevent 694 * rollovers between (1) and (2): the SOF value computed by (1) can be slightly 695 * lower than 4096, and the host SOF counters can have rolled over to 2048. This 696 * case is handled by subtracting 2048 from the SOF value if it exceeds the host 697 * SOF value at the end of the sliding window. 698 * 699 * Finally we subtract a constant from the host timestamps to bring the first 700 * timestamp of the sliding window to 1s. 701 */ 702void uvc_video_clock_update(struct uvc_streaming *stream, 703 struct vb2_v4l2_buffer *vbuf, 704 struct uvc_buffer *buf) 705{ 706 struct uvc_clock *clock = &stream->clock; 707 struct uvc_clock_sample *first; 708 struct uvc_clock_sample *last; 709 unsigned long flags; 710 u64 timestamp; 711 u32 delta_stc; 712 u32 y1, y2; 713 u32 x1, x2; 714 u32 mean; 715 u32 sof; 716 u64 y; 717 718 if (!uvc_hw_timestamps_param) 719 return; 720 721 /* 722 * We will get called from __vb2_queue_cancel() if there are buffers 723 * done but not dequeued by the user, but the sample array has already 724 * been released at that time. Just bail out in that case. 725 */ 726 if (!clock->samples) 727 return; 728 729 spin_lock_irqsave(&clock->lock, flags); 730 731 if (clock->count < clock->size) 732 goto done; 733 734 first = &clock->samples[clock->head]; 735 last = &clock->samples[(clock->head - 1) % clock->size]; 736 737 /* First step, PTS to SOF conversion. */ 738 delta_stc = buf->pts - (1UL << 31); 739 x1 = first->dev_stc - delta_stc; 740 x2 = last->dev_stc - delta_stc; 741 if (x1 == x2) 742 goto done; 743 744 y1 = (first->dev_sof + 2048) << 16; 745 y2 = (last->dev_sof + 2048) << 16; 746 if (y2 < y1) 747 y2 += 2048 << 16; 748 749 y = (u64)(y2 - y1) * (1ULL << 31) + (u64)y1 * (u64)x2 750 - (u64)y2 * (u64)x1; 751 y = div_u64(y, x2 - x1); 752 753 sof = y; 754 755 uvc_dbg(stream->dev, CLOCK, 756 "%s: PTS %u y %llu.%06llu SOF %u.%06llu (x1 %u x2 %u y1 %u y2 %u SOF offset %u)\n", 757 stream->dev->name, buf->pts, 758 y >> 16, div_u64((y & 0xffff) * 1000000, 65536), 759 sof >> 16, div_u64(((u64)sof & 0xffff) * 1000000LLU, 65536), 760 x1, x2, y1, y2, clock->sof_offset); 761 762 /* Second step, SOF to host clock conversion. */ 763 x1 = (uvc_video_clock_host_sof(first) + 2048) << 16; 764 x2 = (uvc_video_clock_host_sof(last) + 2048) << 16; 765 if (x2 < x1) 766 x2 += 2048 << 16; 767 if (x1 == x2) 768 goto done; 769 770 y1 = NSEC_PER_SEC; 771 y2 = (u32)ktime_to_ns(ktime_sub(last->host_time, first->host_time)) + y1; 772 773 /* 774 * Interpolated and host SOF timestamps can wrap around at slightly 775 * different times. Handle this by adding or removing 2048 to or from 776 * the computed SOF value to keep it close to the SOF samples mean 777 * value. 778 */ 779 mean = (x1 + x2) / 2; 780 if (mean - (1024 << 16) > sof) 781 sof += 2048 << 16; 782 else if (sof > mean + (1024 << 16)) 783 sof -= 2048 << 16; 784 785 y = (u64)(y2 - y1) * (u64)sof + (u64)y1 * (u64)x2 786 - (u64)y2 * (u64)x1; 787 y = div_u64(y, x2 - x1); 788 789 timestamp = ktime_to_ns(first->host_time) + y - y1; 790 791 uvc_dbg(stream->dev, CLOCK, 792 "%s: SOF %u.%06llu y %llu ts %llu buf ts %llu (x1 %u/%u/%u x2 %u/%u/%u y1 %u y2 %u)\n", 793 stream->dev->name, 794 sof >> 16, div_u64(((u64)sof & 0xffff) * 1000000LLU, 65536), 795 y, timestamp, vbuf->vb2_buf.timestamp, 796 x1, first->host_sof, first->dev_sof, 797 x2, last->host_sof, last->dev_sof, y1, y2); 798 799 /* Update the V4L2 buffer. */ 800 vbuf->vb2_buf.timestamp = timestamp; 801 802done: 803 spin_unlock_irqrestore(&clock->lock, flags); 804} 805 806/* ------------------------------------------------------------------------ 807 * Stream statistics 808 */ 809 810static void uvc_video_stats_decode(struct uvc_streaming *stream, 811 const u8 *data, int len) 812{ 813 unsigned int header_size; 814 bool has_pts = false; 815 bool has_scr = false; 816 u16 scr_sof; 817 u32 scr_stc; 818 u32 pts; 819 820 if (stream->stats.stream.nb_frames == 0 && 821 stream->stats.frame.nb_packets == 0) 822 stream->stats.stream.start_ts = ktime_get(); 823 824 switch (data[1] & (UVC_STREAM_PTS | UVC_STREAM_SCR)) { 825 case UVC_STREAM_PTS | UVC_STREAM_SCR: 826 header_size = 12; 827 has_pts = true; 828 has_scr = true; 829 break; 830 case UVC_STREAM_PTS: 831 header_size = 6; 832 has_pts = true; 833 break; 834 case UVC_STREAM_SCR: 835 header_size = 8; 836 has_scr = true; 837 break; 838 default: 839 header_size = 2; 840 break; 841 } 842 843 /* Check for invalid headers. */ 844 if (len < header_size || data[0] < header_size) { 845 stream->stats.frame.nb_invalid++; 846 return; 847 } 848 849 /* Extract the timestamps. */ 850 if (has_pts) 851 pts = get_unaligned_le32(&data[2]); 852 853 if (has_scr) { 854 scr_stc = get_unaligned_le32(&data[header_size - 6]); 855 scr_sof = get_unaligned_le16(&data[header_size - 2]); 856 } 857 858 /* Is PTS constant through the whole frame ? */ 859 if (has_pts && stream->stats.frame.nb_pts) { 860 if (stream->stats.frame.pts != pts) { 861 stream->stats.frame.nb_pts_diffs++; 862 stream->stats.frame.last_pts_diff = 863 stream->stats.frame.nb_packets; 864 } 865 } 866 867 if (has_pts) { 868 stream->stats.frame.nb_pts++; 869 stream->stats.frame.pts = pts; 870 } 871 872 /* 873 * Do all frames have a PTS in their first non-empty packet, or before 874 * their first empty packet ? 875 */ 876 if (stream->stats.frame.size == 0) { 877 if (len > header_size) 878 stream->stats.frame.has_initial_pts = has_pts; 879 if (len == header_size && has_pts) 880 stream->stats.frame.has_early_pts = true; 881 } 882 883 /* Do the SCR.STC and SCR.SOF fields vary through the frame ? */ 884 if (has_scr && stream->stats.frame.nb_scr) { 885 if (stream->stats.frame.scr_stc != scr_stc) 886 stream->stats.frame.nb_scr_diffs++; 887 } 888 889 if (has_scr) { 890 /* Expand the SOF counter to 32 bits and store its value. */ 891 if (stream->stats.stream.nb_frames > 0 || 892 stream->stats.frame.nb_scr > 0) 893 stream->stats.stream.scr_sof_count += 894 (scr_sof - stream->stats.stream.scr_sof) % 2048; 895 stream->stats.stream.scr_sof = scr_sof; 896 897 stream->stats.frame.nb_scr++; 898 stream->stats.frame.scr_stc = scr_stc; 899 stream->stats.frame.scr_sof = scr_sof; 900 901 if (scr_sof < stream->stats.stream.min_sof) 902 stream->stats.stream.min_sof = scr_sof; 903 if (scr_sof > stream->stats.stream.max_sof) 904 stream->stats.stream.max_sof = scr_sof; 905 } 906 907 /* Record the first non-empty packet number. */ 908 if (stream->stats.frame.size == 0 && len > header_size) 909 stream->stats.frame.first_data = stream->stats.frame.nb_packets; 910 911 /* Update the frame size. */ 912 stream->stats.frame.size += len - header_size; 913 914 /* Update the packets counters. */ 915 stream->stats.frame.nb_packets++; 916 if (len <= header_size) 917 stream->stats.frame.nb_empty++; 918 919 if (data[1] & UVC_STREAM_ERR) 920 stream->stats.frame.nb_errors++; 921} 922 923static void uvc_video_stats_update(struct uvc_streaming *stream) 924{ 925 struct uvc_stats_frame *frame = &stream->stats.frame; 926 927 uvc_dbg(stream->dev, STATS, 928 "frame %u stats: %u/%u/%u packets, %u/%u/%u pts (%searly %sinitial), %u/%u scr, last pts/stc/sof %u/%u/%u\n", 929 stream->sequence, frame->first_data, 930 frame->nb_packets - frame->nb_empty, frame->nb_packets, 931 frame->nb_pts_diffs, frame->last_pts_diff, frame->nb_pts, 932 frame->has_early_pts ? "" : "!", 933 frame->has_initial_pts ? "" : "!", 934 frame->nb_scr_diffs, frame->nb_scr, 935 frame->pts, frame->scr_stc, frame->scr_sof); 936 937 stream->stats.stream.nb_frames++; 938 stream->stats.stream.nb_packets += stream->stats.frame.nb_packets; 939 stream->stats.stream.nb_empty += stream->stats.frame.nb_empty; 940 stream->stats.stream.nb_errors += stream->stats.frame.nb_errors; 941 stream->stats.stream.nb_invalid += stream->stats.frame.nb_invalid; 942 943 if (frame->has_early_pts) 944 stream->stats.stream.nb_pts_early++; 945 if (frame->has_initial_pts) 946 stream->stats.stream.nb_pts_initial++; 947 if (frame->last_pts_diff <= frame->first_data) 948 stream->stats.stream.nb_pts_constant++; 949 if (frame->nb_scr >= frame->nb_packets - frame->nb_empty) 950 stream->stats.stream.nb_scr_count_ok++; 951 if (frame->nb_scr_diffs + 1 == frame->nb_scr) 952 stream->stats.stream.nb_scr_diffs_ok++; 953 954 memset(&stream->stats.frame, 0, sizeof(stream->stats.frame)); 955} 956 957size_t uvc_video_stats_dump(struct uvc_streaming *stream, char *buf, 958 size_t size) 959{ 960 unsigned int scr_sof_freq; 961 unsigned int duration; 962 size_t count = 0; 963 964 /* 965 * Compute the SCR.SOF frequency estimate. At the nominal 1kHz SOF 966 * frequency this will not overflow before more than 1h. 967 */ 968 duration = ktime_ms_delta(stream->stats.stream.stop_ts, 969 stream->stats.stream.start_ts); 970 if (duration != 0) 971 scr_sof_freq = stream->stats.stream.scr_sof_count * 1000 972 / duration; 973 else 974 scr_sof_freq = 0; 975 976 count += scnprintf(buf + count, size - count, 977 "frames: %u\npackets: %u\nempty: %u\n" 978 "errors: %u\ninvalid: %u\n", 979 stream->stats.stream.nb_frames, 980 stream->stats.stream.nb_packets, 981 stream->stats.stream.nb_empty, 982 stream->stats.stream.nb_errors, 983 stream->stats.stream.nb_invalid); 984 count += scnprintf(buf + count, size - count, 985 "pts: %u early, %u initial, %u ok\n", 986 stream->stats.stream.nb_pts_early, 987 stream->stats.stream.nb_pts_initial, 988 stream->stats.stream.nb_pts_constant); 989 count += scnprintf(buf + count, size - count, 990 "scr: %u count ok, %u diff ok\n", 991 stream->stats.stream.nb_scr_count_ok, 992 stream->stats.stream.nb_scr_diffs_ok); 993 count += scnprintf(buf + count, size - count, 994 "sof: %u <= sof <= %u, freq %u.%03u kHz\n", 995 stream->stats.stream.min_sof, 996 stream->stats.stream.max_sof, 997 scr_sof_freq / 1000, scr_sof_freq % 1000); 998 999 return count; 1000} 1001 1002static void uvc_video_stats_start(struct uvc_streaming *stream) 1003{ 1004 memset(&stream->stats, 0, sizeof(stream->stats)); 1005 stream->stats.stream.min_sof = 2048; 1006} 1007 1008static void uvc_video_stats_stop(struct uvc_streaming *stream) 1009{ 1010 stream->stats.stream.stop_ts = ktime_get(); 1011} 1012 1013/* ------------------------------------------------------------------------ 1014 * Video codecs 1015 */ 1016 1017/* 1018 * Video payload decoding is handled by uvc_video_decode_start(), 1019 * uvc_video_decode_data() and uvc_video_decode_end(). 1020 * 1021 * uvc_video_decode_start is called with URB data at the start of a bulk or 1022 * isochronous payload. It processes header data and returns the header size 1023 * in bytes if successful. If an error occurs, it returns a negative error 1024 * code. The following error codes have special meanings. 1025 * 1026 * - EAGAIN informs the caller that the current video buffer should be marked 1027 * as done, and that the function should be called again with the same data 1028 * and a new video buffer. This is used when end of frame conditions can be 1029 * reliably detected at the beginning of the next frame only. 1030 * 1031 * If an error other than -EAGAIN is returned, the caller will drop the current 1032 * payload. No call to uvc_video_decode_data and uvc_video_decode_end will be 1033 * made until the next payload. -ENODATA can be used to drop the current 1034 * payload if no other error code is appropriate. 1035 * 1036 * uvc_video_decode_data is called for every URB with URB data. It copies the 1037 * data to the video buffer. 1038 * 1039 * uvc_video_decode_end is called with header data at the end of a bulk or 1040 * isochronous payload. It performs any additional header data processing and 1041 * returns 0 or a negative error code if an error occurred. As header data have 1042 * already been processed by uvc_video_decode_start, this functions isn't 1043 * required to perform sanity checks a second time. 1044 * 1045 * For isochronous transfers where a payload is always transferred in a single 1046 * URB, the three functions will be called in a row. 1047 * 1048 * To let the decoder process header data and update its internal state even 1049 * when no video buffer is available, uvc_video_decode_start must be prepared 1050 * to be called with a NULL buf parameter. uvc_video_decode_data and 1051 * uvc_video_decode_end will never be called with a NULL buffer. 1052 */ 1053static int uvc_video_decode_start(struct uvc_streaming *stream, 1054 struct uvc_buffer *buf, const u8 *data, int len) 1055{ 1056 u8 fid; 1057 1058 /* 1059 * Sanity checks: 1060 * - packet must be at least 2 bytes long 1061 * - bHeaderLength value must be at least 2 bytes (see above) 1062 * - bHeaderLength value can't be larger than the packet size. 1063 */ 1064 if (len < 2 || data[0] < 2 || data[0] > len) { 1065 stream->stats.frame.nb_invalid++; 1066 return -EINVAL; 1067 } 1068 1069 fid = data[1] & UVC_STREAM_FID; 1070 1071 /* 1072 * Increase the sequence number regardless of any buffer states, so 1073 * that discontinuous sequence numbers always indicate lost frames. 1074 */ 1075 if (stream->last_fid != fid) { 1076 stream->sequence++; 1077 if (stream->sequence) 1078 uvc_video_stats_update(stream); 1079 } 1080 1081 uvc_video_clock_decode(stream, buf, data, len); 1082 uvc_video_stats_decode(stream, data, len); 1083 1084 /* 1085 * Store the payload FID bit and return immediately when the buffer is 1086 * NULL. 1087 */ 1088 if (buf == NULL) { 1089 stream->last_fid = fid; 1090 return -ENODATA; 1091 } 1092 1093 /* Mark the buffer as bad if the error bit is set. */ 1094 if (data[1] & UVC_STREAM_ERR) { 1095 uvc_dbg(stream->dev, FRAME, 1096 "Marking buffer as bad (error bit set)\n"); 1097 buf->error = 1; 1098 } 1099 1100 /* 1101 * Synchronize to the input stream by waiting for the FID bit to be 1102 * toggled when the buffer state is not UVC_BUF_STATE_ACTIVE. 1103 * stream->last_fid is initialized to -1, so the first isochronous 1104 * frame will always be in sync. 1105 * 1106 * If the device doesn't toggle the FID bit, invert stream->last_fid 1107 * when the EOF bit is set to force synchronisation on the next packet. 1108 */ 1109 if (buf->state != UVC_BUF_STATE_ACTIVE) { 1110 if (fid == stream->last_fid) { 1111 uvc_dbg(stream->dev, FRAME, 1112 "Dropping payload (out of sync)\n"); 1113 if ((stream->dev->quirks & UVC_QUIRK_STREAM_NO_FID) && 1114 (data[1] & UVC_STREAM_EOF)) 1115 stream->last_fid ^= UVC_STREAM_FID; 1116 return -ENODATA; 1117 } 1118 1119 buf->buf.field = V4L2_FIELD_NONE; 1120 buf->buf.sequence = stream->sequence; 1121 buf->buf.vb2_buf.timestamp = ktime_to_ns(uvc_video_get_time()); 1122 1123 /* TODO: Handle PTS and SCR. */ 1124 buf->state = UVC_BUF_STATE_ACTIVE; 1125 } 1126 1127 /* 1128 * Mark the buffer as done if we're at the beginning of a new frame. 1129 * End of frame detection is better implemented by checking the EOF 1130 * bit (FID bit toggling is delayed by one frame compared to the EOF 1131 * bit), but some devices don't set the bit at end of frame (and the 1132 * last payload can be lost anyway). We thus must check if the FID has 1133 * been toggled. 1134 * 1135 * stream->last_fid is initialized to -1, so the first isochronous 1136 * frame will never trigger an end of frame detection. 1137 * 1138 * Empty buffers (bytesused == 0) don't trigger end of frame detection 1139 * as it doesn't make sense to return an empty buffer. This also 1140 * avoids detecting end of frame conditions at FID toggling if the 1141 * previous payload had the EOF bit set. 1142 */ 1143 if (fid != stream->last_fid && buf->bytesused != 0) { 1144 uvc_dbg(stream->dev, FRAME, 1145 "Frame complete (FID bit toggled)\n"); 1146 buf->state = UVC_BUF_STATE_READY; 1147 return -EAGAIN; 1148 } 1149 1150 stream->last_fid = fid; 1151 1152 return data[0]; 1153} 1154 1155static inline enum dma_data_direction uvc_stream_dir( 1156 struct uvc_streaming *stream) 1157{ 1158 if (stream->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) 1159 return DMA_FROM_DEVICE; 1160 else 1161 return DMA_TO_DEVICE; 1162} 1163 1164static inline struct device *uvc_stream_to_dmadev(struct uvc_streaming *stream) 1165{ 1166 return bus_to_hcd(stream->dev->udev->bus)->self.sysdev; 1167} 1168 1169static int uvc_submit_urb(struct uvc_urb *uvc_urb, gfp_t mem_flags) 1170{ 1171 /* Sync DMA. */ 1172 dma_sync_sgtable_for_device(uvc_stream_to_dmadev(uvc_urb->stream), 1173 uvc_urb->sgt, 1174 uvc_stream_dir(uvc_urb->stream)); 1175 return usb_submit_urb(uvc_urb->urb, mem_flags); 1176} 1177 1178/* 1179 * uvc_video_decode_data_work: Asynchronous memcpy processing 1180 * 1181 * Copy URB data to video buffers in process context, releasing buffer 1182 * references and requeuing the URB when done. 1183 */ 1184static void uvc_video_copy_data_work(struct work_struct *work) 1185{ 1186 struct uvc_urb *uvc_urb = container_of(work, struct uvc_urb, work); 1187 unsigned int i; 1188 int ret; 1189 1190 for (i = 0; i < uvc_urb->async_operations; i++) { 1191 struct uvc_copy_op *op = &uvc_urb->copy_operations[i]; 1192 1193 memcpy(op->dst, op->src, op->len); 1194 1195 /* Release reference taken on this buffer. */ 1196 uvc_queue_buffer_release(op->buf); 1197 } 1198 1199 ret = uvc_submit_urb(uvc_urb, GFP_KERNEL); 1200 if (ret < 0) 1201 dev_err(&uvc_urb->stream->intf->dev, 1202 "Failed to resubmit video URB (%d).\n", ret); 1203} 1204 1205static void uvc_video_decode_data(struct uvc_urb *uvc_urb, 1206 struct uvc_buffer *buf, const u8 *data, int len) 1207{ 1208 unsigned int active_op = uvc_urb->async_operations; 1209 struct uvc_copy_op *op = &uvc_urb->copy_operations[active_op]; 1210 unsigned int maxlen; 1211 1212 if (len <= 0) 1213 return; 1214 1215 maxlen = buf->length - buf->bytesused; 1216 1217 /* Take a buffer reference for async work. */ 1218 kref_get(&buf->ref); 1219 1220 op->buf = buf; 1221 op->src = data; 1222 op->dst = buf->mem + buf->bytesused; 1223 op->len = min_t(unsigned int, len, maxlen); 1224 1225 buf->bytesused += op->len; 1226 1227 /* Complete the current frame if the buffer size was exceeded. */ 1228 if (len > maxlen) { 1229 uvc_dbg(uvc_urb->stream->dev, FRAME, 1230 "Frame complete (overflow)\n"); 1231 buf->error = 1; 1232 buf->state = UVC_BUF_STATE_READY; 1233 } 1234 1235 uvc_urb->async_operations++; 1236} 1237 1238static void uvc_video_decode_end(struct uvc_streaming *stream, 1239 struct uvc_buffer *buf, const u8 *data, int len) 1240{ 1241 /* Mark the buffer as done if the EOF marker is set. */ 1242 if (data[1] & UVC_STREAM_EOF && buf->bytesused != 0) { 1243 uvc_dbg(stream->dev, FRAME, "Frame complete (EOF found)\n"); 1244 if (data[0] == len) 1245 uvc_dbg(stream->dev, FRAME, "EOF in empty payload\n"); 1246 buf->state = UVC_BUF_STATE_READY; 1247 if (stream->dev->quirks & UVC_QUIRK_STREAM_NO_FID) 1248 stream->last_fid ^= UVC_STREAM_FID; 1249 } 1250} 1251 1252/* 1253 * Video payload encoding is handled by uvc_video_encode_header() and 1254 * uvc_video_encode_data(). Only bulk transfers are currently supported. 1255 * 1256 * uvc_video_encode_header is called at the start of a payload. It adds header 1257 * data to the transfer buffer and returns the header size. As the only known 1258 * UVC output device transfers a whole frame in a single payload, the EOF bit 1259 * is always set in the header. 1260 * 1261 * uvc_video_encode_data is called for every URB and copies the data from the 1262 * video buffer to the transfer buffer. 1263 */ 1264static int uvc_video_encode_header(struct uvc_streaming *stream, 1265 struct uvc_buffer *buf, u8 *data, int len) 1266{ 1267 data[0] = 2; /* Header length */ 1268 data[1] = UVC_STREAM_EOH | UVC_STREAM_EOF 1269 | (stream->last_fid & UVC_STREAM_FID); 1270 return 2; 1271} 1272 1273static int uvc_video_encode_data(struct uvc_streaming *stream, 1274 struct uvc_buffer *buf, u8 *data, int len) 1275{ 1276 struct uvc_video_queue *queue = &stream->queue; 1277 unsigned int nbytes; 1278 void *mem; 1279 1280 /* Copy video data to the URB buffer. */ 1281 mem = buf->mem + queue->buf_used; 1282 nbytes = min((unsigned int)len, buf->bytesused - queue->buf_used); 1283 nbytes = min(stream->bulk.max_payload_size - stream->bulk.payload_size, 1284 nbytes); 1285 memcpy(data, mem, nbytes); 1286 1287 queue->buf_used += nbytes; 1288 1289 return nbytes; 1290} 1291 1292/* ------------------------------------------------------------------------ 1293 * Metadata 1294 */ 1295 1296/* 1297 * Additionally to the payload headers we also want to provide the user with USB 1298 * Frame Numbers and system time values. The resulting buffer is thus composed 1299 * of blocks, containing a 64-bit timestamp in nanoseconds, a 16-bit USB Frame 1300 * Number, and a copy of the payload header. 1301 * 1302 * Ideally we want to capture all payload headers for each frame. However, their 1303 * number is unknown and unbound. We thus drop headers that contain no vendor 1304 * data and that either contain no SCR value or an SCR value identical to the 1305 * previous header. 1306 */ 1307static void uvc_video_decode_meta(struct uvc_streaming *stream, 1308 struct uvc_buffer *meta_buf, 1309 const u8 *mem, unsigned int length) 1310{ 1311 struct uvc_meta_buf *meta; 1312 size_t len_std = 2; 1313 bool has_pts, has_scr; 1314 unsigned long flags; 1315 unsigned int sof; 1316 ktime_t time; 1317 const u8 *scr; 1318 1319 if (!meta_buf || length == 2) 1320 return; 1321 1322 if (meta_buf->length - meta_buf->bytesused < 1323 length + sizeof(meta->ns) + sizeof(meta->sof)) { 1324 meta_buf->error = 1; 1325 return; 1326 } 1327 1328 has_pts = mem[1] & UVC_STREAM_PTS; 1329 has_scr = mem[1] & UVC_STREAM_SCR; 1330 1331 if (has_pts) { 1332 len_std += 4; 1333 scr = mem + 6; 1334 } else { 1335 scr = mem + 2; 1336 } 1337 1338 if (has_scr) 1339 len_std += 6; 1340 1341 if (stream->meta.format == V4L2_META_FMT_UVC) 1342 length = len_std; 1343 1344 if (length == len_std && (!has_scr || 1345 !memcmp(scr, stream->clock.last_scr, 6))) 1346 return; 1347 1348 meta = (struct uvc_meta_buf *)((u8 *)meta_buf->mem + meta_buf->bytesused); 1349 local_irq_save(flags); 1350 time = uvc_video_get_time(); 1351 sof = usb_get_current_frame_number(stream->dev->udev); 1352 local_irq_restore(flags); 1353 put_unaligned(ktime_to_ns(time), &meta->ns); 1354 put_unaligned(sof, &meta->sof); 1355 1356 if (has_scr) 1357 memcpy(stream->clock.last_scr, scr, 6); 1358 1359 meta->length = mem[0]; 1360 meta->flags = mem[1]; 1361 memcpy(meta->buf, &mem[2], length - 2); 1362 meta_buf->bytesused += length + sizeof(meta->ns) + sizeof(meta->sof); 1363 1364 uvc_dbg(stream->dev, FRAME, 1365 "%s(): t-sys %lluns, SOF %u, len %u, flags 0x%x, PTS %u, STC %u frame SOF %u\n", 1366 __func__, ktime_to_ns(time), meta->sof, meta->length, 1367 meta->flags, 1368 has_pts ? *(u32 *)meta->buf : 0, 1369 has_scr ? *(u32 *)scr : 0, 1370 has_scr ? *(u32 *)(scr + 4) & 0x7ff : 0); 1371} 1372 1373/* ------------------------------------------------------------------------ 1374 * URB handling 1375 */ 1376 1377/* 1378 * Set error flag for incomplete buffer. 1379 */ 1380static void uvc_video_validate_buffer(const struct uvc_streaming *stream, 1381 struct uvc_buffer *buf) 1382{ 1383 if (stream->ctrl.dwMaxVideoFrameSize != buf->bytesused && 1384 !(stream->cur_format->flags & UVC_FMT_FLAG_COMPRESSED)) 1385 buf->error = 1; 1386} 1387 1388/* 1389 * Completion handler for video URBs. 1390 */ 1391 1392static void uvc_video_next_buffers(struct uvc_streaming *stream, 1393 struct uvc_buffer **video_buf, struct uvc_buffer **meta_buf) 1394{ 1395 uvc_video_validate_buffer(stream, *video_buf); 1396 1397 if (*meta_buf) { 1398 struct vb2_v4l2_buffer *vb2_meta = &(*meta_buf)->buf; 1399 const struct vb2_v4l2_buffer *vb2_video = &(*video_buf)->buf; 1400 1401 vb2_meta->sequence = vb2_video->sequence; 1402 vb2_meta->field = vb2_video->field; 1403 vb2_meta->vb2_buf.timestamp = vb2_video->vb2_buf.timestamp; 1404 1405 (*meta_buf)->state = UVC_BUF_STATE_READY; 1406 if (!(*meta_buf)->error) 1407 (*meta_buf)->error = (*video_buf)->error; 1408 *meta_buf = uvc_queue_next_buffer(&stream->meta.queue, 1409 *meta_buf); 1410 } 1411 *video_buf = uvc_queue_next_buffer(&stream->queue, *video_buf); 1412} 1413 1414static void uvc_video_decode_isoc(struct uvc_urb *uvc_urb, 1415 struct uvc_buffer *buf, struct uvc_buffer *meta_buf) 1416{ 1417 struct urb *urb = uvc_urb->urb; 1418 struct uvc_streaming *stream = uvc_urb->stream; 1419 u8 *mem; 1420 int ret, i; 1421 1422 for (i = 0; i < urb->number_of_packets; ++i) { 1423 if (urb->iso_frame_desc[i].status < 0) { 1424 uvc_dbg(stream->dev, FRAME, 1425 "USB isochronous frame lost (%d)\n", 1426 urb->iso_frame_desc[i].status); 1427 /* Mark the buffer as faulty. */ 1428 if (buf != NULL) 1429 buf->error = 1; 1430 continue; 1431 } 1432 1433 /* Decode the payload header. */ 1434 mem = urb->transfer_buffer + urb->iso_frame_desc[i].offset; 1435 do { 1436 ret = uvc_video_decode_start(stream, buf, mem, 1437 urb->iso_frame_desc[i].actual_length); 1438 if (ret == -EAGAIN) 1439 uvc_video_next_buffers(stream, &buf, &meta_buf); 1440 } while (ret == -EAGAIN); 1441 1442 if (ret < 0) 1443 continue; 1444 1445 uvc_video_decode_meta(stream, meta_buf, mem, ret); 1446 1447 /* Decode the payload data. */ 1448 uvc_video_decode_data(uvc_urb, buf, mem + ret, 1449 urb->iso_frame_desc[i].actual_length - ret); 1450 1451 /* Process the header again. */ 1452 uvc_video_decode_end(stream, buf, mem, 1453 urb->iso_frame_desc[i].actual_length); 1454 1455 if (buf->state == UVC_BUF_STATE_READY) 1456 uvc_video_next_buffers(stream, &buf, &meta_buf); 1457 } 1458} 1459 1460static void uvc_video_decode_bulk(struct uvc_urb *uvc_urb, 1461 struct uvc_buffer *buf, struct uvc_buffer *meta_buf) 1462{ 1463 struct urb *urb = uvc_urb->urb; 1464 struct uvc_streaming *stream = uvc_urb->stream; 1465 u8 *mem; 1466 int len, ret; 1467 1468 /* 1469 * Ignore ZLPs if they're not part of a frame, otherwise process them 1470 * to trigger the end of payload detection. 1471 */ 1472 if (urb->actual_length == 0 && stream->bulk.header_size == 0) 1473 return; 1474 1475 mem = urb->transfer_buffer; 1476 len = urb->actual_length; 1477 stream->bulk.payload_size += len; 1478 1479 /* 1480 * If the URB is the first of its payload, decode and save the 1481 * header. 1482 */ 1483 if (stream->bulk.header_size == 0 && !stream->bulk.skip_payload) { 1484 do { 1485 ret = uvc_video_decode_start(stream, buf, mem, len); 1486 if (ret == -EAGAIN) 1487 uvc_video_next_buffers(stream, &buf, &meta_buf); 1488 } while (ret == -EAGAIN); 1489 1490 /* If an error occurred skip the rest of the payload. */ 1491 if (ret < 0 || buf == NULL) { 1492 stream->bulk.skip_payload = 1; 1493 } else { 1494 memcpy(stream->bulk.header, mem, ret); 1495 stream->bulk.header_size = ret; 1496 1497 uvc_video_decode_meta(stream, meta_buf, mem, ret); 1498 1499 mem += ret; 1500 len -= ret; 1501 } 1502 } 1503 1504 /* 1505 * The buffer queue might have been cancelled while a bulk transfer 1506 * was in progress, so we can reach here with buf equal to NULL. Make 1507 * sure buf is never dereferenced if NULL. 1508 */ 1509 1510 /* Prepare video data for processing. */ 1511 if (!stream->bulk.skip_payload && buf != NULL) 1512 uvc_video_decode_data(uvc_urb, buf, mem, len); 1513 1514 /* 1515 * Detect the payload end by a URB smaller than the maximum size (or 1516 * a payload size equal to the maximum) and process the header again. 1517 */ 1518 if (urb->actual_length < urb->transfer_buffer_length || 1519 stream->bulk.payload_size >= stream->bulk.max_payload_size) { 1520 if (!stream->bulk.skip_payload && buf != NULL) { 1521 uvc_video_decode_end(stream, buf, stream->bulk.header, 1522 stream->bulk.payload_size); 1523 if (buf->state == UVC_BUF_STATE_READY) 1524 uvc_video_next_buffers(stream, &buf, &meta_buf); 1525 } 1526 1527 stream->bulk.header_size = 0; 1528 stream->bulk.skip_payload = 0; 1529 stream->bulk.payload_size = 0; 1530 } 1531} 1532 1533static void uvc_video_encode_bulk(struct uvc_urb *uvc_urb, 1534 struct uvc_buffer *buf, struct uvc_buffer *meta_buf) 1535{ 1536 struct urb *urb = uvc_urb->urb; 1537 struct uvc_streaming *stream = uvc_urb->stream; 1538 1539 u8 *mem = urb->transfer_buffer; 1540 int len = stream->urb_size, ret; 1541 1542 if (buf == NULL) { 1543 urb->transfer_buffer_length = 0; 1544 return; 1545 } 1546 1547 /* If the URB is the first of its payload, add the header. */ 1548 if (stream->bulk.header_size == 0) { 1549 ret = uvc_video_encode_header(stream, buf, mem, len); 1550 stream->bulk.header_size = ret; 1551 stream->bulk.payload_size += ret; 1552 mem += ret; 1553 len -= ret; 1554 } 1555 1556 /* Process video data. */ 1557 ret = uvc_video_encode_data(stream, buf, mem, len); 1558 1559 stream->bulk.payload_size += ret; 1560 len -= ret; 1561 1562 if (buf->bytesused == stream->queue.buf_used || 1563 stream->bulk.payload_size == stream->bulk.max_payload_size) { 1564 if (buf->bytesused == stream->queue.buf_used) { 1565 stream->queue.buf_used = 0; 1566 buf->state = UVC_BUF_STATE_READY; 1567 buf->buf.sequence = ++stream->sequence; 1568 uvc_queue_next_buffer(&stream->queue, buf); 1569 stream->last_fid ^= UVC_STREAM_FID; 1570 } 1571 1572 stream->bulk.header_size = 0; 1573 stream->bulk.payload_size = 0; 1574 } 1575 1576 urb->transfer_buffer_length = stream->urb_size - len; 1577} 1578 1579static void uvc_video_complete(struct urb *urb) 1580{ 1581 struct uvc_urb *uvc_urb = urb->context; 1582 struct uvc_streaming *stream = uvc_urb->stream; 1583 struct uvc_video_queue *queue = &stream->queue; 1584 struct uvc_video_queue *qmeta = &stream->meta.queue; 1585 struct vb2_queue *vb2_qmeta = stream->meta.vdev.queue; 1586 struct uvc_buffer *buf = NULL; 1587 struct uvc_buffer *buf_meta = NULL; 1588 unsigned long flags; 1589 int ret; 1590 1591 switch (urb->status) { 1592 case 0: 1593 break; 1594 1595 default: 1596 dev_warn(&stream->intf->dev, 1597 "Non-zero status (%d) in video completion handler.\n", 1598 urb->status); 1599 fallthrough; 1600 case -ENOENT: /* usb_poison_urb() called. */ 1601 if (stream->frozen) 1602 return; 1603 fallthrough; 1604 case -ECONNRESET: /* usb_unlink_urb() called. */ 1605 case -ESHUTDOWN: /* The endpoint is being disabled. */ 1606 uvc_queue_cancel(queue, urb->status == -ESHUTDOWN); 1607 if (vb2_qmeta) 1608 uvc_queue_cancel(qmeta, urb->status == -ESHUTDOWN); 1609 return; 1610 } 1611 1612 buf = uvc_queue_get_current_buffer(queue); 1613 1614 if (vb2_qmeta) { 1615 spin_lock_irqsave(&qmeta->irqlock, flags); 1616 if (!list_empty(&qmeta->irqqueue)) 1617 buf_meta = list_first_entry(&qmeta->irqqueue, 1618 struct uvc_buffer, queue); 1619 spin_unlock_irqrestore(&qmeta->irqlock, flags); 1620 } 1621 1622 /* Re-initialise the URB async work. */ 1623 uvc_urb->async_operations = 0; 1624 1625 /* Sync DMA and invalidate vmap range. */ 1626 dma_sync_sgtable_for_cpu(uvc_stream_to_dmadev(uvc_urb->stream), 1627 uvc_urb->sgt, uvc_stream_dir(stream)); 1628 invalidate_kernel_vmap_range(uvc_urb->buffer, 1629 uvc_urb->stream->urb_size); 1630 1631 /* 1632 * Process the URB headers, and optionally queue expensive memcpy tasks 1633 * to be deferred to a work queue. 1634 */ 1635 stream->decode(uvc_urb, buf, buf_meta); 1636 1637 /* If no async work is needed, resubmit the URB immediately. */ 1638 if (!uvc_urb->async_operations) { 1639 ret = uvc_submit_urb(uvc_urb, GFP_ATOMIC); 1640 if (ret < 0) 1641 dev_err(&stream->intf->dev, 1642 "Failed to resubmit video URB (%d).\n", ret); 1643 return; 1644 } 1645 1646 queue_work(stream->async_wq, &uvc_urb->work); 1647} 1648 1649/* 1650 * Free transfer buffers. 1651 */ 1652static void uvc_free_urb_buffers(struct uvc_streaming *stream) 1653{ 1654 struct device *dma_dev = uvc_stream_to_dmadev(stream); 1655 struct uvc_urb *uvc_urb; 1656 1657 for_each_uvc_urb(uvc_urb, stream) { 1658 if (!uvc_urb->buffer) 1659 continue; 1660 1661 dma_vunmap_noncontiguous(dma_dev, uvc_urb->buffer); 1662 dma_free_noncontiguous(dma_dev, stream->urb_size, uvc_urb->sgt, 1663 uvc_stream_dir(stream)); 1664 1665 uvc_urb->buffer = NULL; 1666 uvc_urb->sgt = NULL; 1667 } 1668 1669 stream->urb_size = 0; 1670} 1671 1672static bool uvc_alloc_urb_buffer(struct uvc_streaming *stream, 1673 struct uvc_urb *uvc_urb, gfp_t gfp_flags) 1674{ 1675 struct device *dma_dev = uvc_stream_to_dmadev(stream); 1676 1677 uvc_urb->sgt = dma_alloc_noncontiguous(dma_dev, stream->urb_size, 1678 uvc_stream_dir(stream), 1679 gfp_flags, 0); 1680 if (!uvc_urb->sgt) 1681 return false; 1682 uvc_urb->dma = uvc_urb->sgt->sgl->dma_address; 1683 1684 uvc_urb->buffer = dma_vmap_noncontiguous(dma_dev, stream->urb_size, 1685 uvc_urb->sgt); 1686 if (!uvc_urb->buffer) { 1687 dma_free_noncontiguous(dma_dev, stream->urb_size, 1688 uvc_urb->sgt, 1689 uvc_stream_dir(stream)); 1690 uvc_urb->sgt = NULL; 1691 return false; 1692 } 1693 1694 return true; 1695} 1696 1697/* 1698 * Allocate transfer buffers. This function can be called with buffers 1699 * already allocated when resuming from suspend, in which case it will 1700 * return without touching the buffers. 1701 * 1702 * Limit the buffer size to UVC_MAX_PACKETS bulk/isochronous packets. If the 1703 * system is too low on memory try successively smaller numbers of packets 1704 * until allocation succeeds. 1705 * 1706 * Return the number of allocated packets on success or 0 when out of memory. 1707 */ 1708static int uvc_alloc_urb_buffers(struct uvc_streaming *stream, 1709 unsigned int size, unsigned int psize, gfp_t gfp_flags) 1710{ 1711 unsigned int npackets; 1712 unsigned int i; 1713 1714 /* Buffers are already allocated, bail out. */ 1715 if (stream->urb_size) 1716 return stream->urb_size / psize; 1717 1718 /* 1719 * Compute the number of packets. Bulk endpoints might transfer UVC 1720 * payloads across multiple URBs. 1721 */ 1722 npackets = DIV_ROUND_UP(size, psize); 1723 if (npackets > UVC_MAX_PACKETS) 1724 npackets = UVC_MAX_PACKETS; 1725 1726 /* Retry allocations until one succeed. */ 1727 for (; npackets > 1; npackets /= 2) { 1728 stream->urb_size = psize * npackets; 1729 1730 for (i = 0; i < UVC_URBS; ++i) { 1731 struct uvc_urb *uvc_urb = &stream->uvc_urb[i]; 1732 1733 if (!uvc_alloc_urb_buffer(stream, uvc_urb, gfp_flags)) { 1734 uvc_free_urb_buffers(stream); 1735 break; 1736 } 1737 1738 uvc_urb->stream = stream; 1739 } 1740 1741 if (i == UVC_URBS) { 1742 uvc_dbg(stream->dev, VIDEO, 1743 "Allocated %u URB buffers of %ux%u bytes each\n", 1744 UVC_URBS, npackets, psize); 1745 return npackets; 1746 } 1747 } 1748 1749 uvc_dbg(stream->dev, VIDEO, 1750 "Failed to allocate URB buffers (%u bytes per packet)\n", 1751 psize); 1752 return 0; 1753} 1754 1755/* 1756 * Uninitialize isochronous/bulk URBs and free transfer buffers. 1757 */ 1758static void uvc_video_stop_transfer(struct uvc_streaming *stream, 1759 int free_buffers) 1760{ 1761 struct uvc_urb *uvc_urb; 1762 1763 uvc_video_stats_stop(stream); 1764 1765 /* 1766 * We must poison the URBs rather than kill them to ensure that even 1767 * after the completion handler returns, any asynchronous workqueues 1768 * will be prevented from resubmitting the URBs. 1769 */ 1770 for_each_uvc_urb(uvc_urb, stream) 1771 usb_poison_urb(uvc_urb->urb); 1772 1773 flush_workqueue(stream->async_wq); 1774 1775 for_each_uvc_urb(uvc_urb, stream) { 1776 usb_free_urb(uvc_urb->urb); 1777 uvc_urb->urb = NULL; 1778 } 1779 1780 if (free_buffers) 1781 uvc_free_urb_buffers(stream); 1782} 1783 1784/* 1785 * Compute the maximum number of bytes per interval for an endpoint. 1786 */ 1787u16 uvc_endpoint_max_bpi(struct usb_device *dev, struct usb_host_endpoint *ep) 1788{ 1789 u16 psize; 1790 1791 switch (dev->speed) { 1792 case USB_SPEED_SUPER: 1793 case USB_SPEED_SUPER_PLUS: 1794 return le16_to_cpu(ep->ss_ep_comp.wBytesPerInterval); 1795 default: 1796 psize = usb_endpoint_maxp(&ep->desc); 1797 psize *= usb_endpoint_maxp_mult(&ep->desc); 1798 return psize; 1799 } 1800} 1801 1802/* 1803 * Initialize isochronous URBs and allocate transfer buffers. The packet size 1804 * is given by the endpoint. 1805 */ 1806static int uvc_init_video_isoc(struct uvc_streaming *stream, 1807 struct usb_host_endpoint *ep, gfp_t gfp_flags) 1808{ 1809 struct urb *urb; 1810 struct uvc_urb *uvc_urb; 1811 unsigned int npackets, i; 1812 u16 psize; 1813 u32 size; 1814 1815 psize = uvc_endpoint_max_bpi(stream->dev->udev, ep); 1816 size = stream->ctrl.dwMaxVideoFrameSize; 1817 1818 npackets = uvc_alloc_urb_buffers(stream, size, psize, gfp_flags); 1819 if (npackets == 0) 1820 return -ENOMEM; 1821 1822 size = npackets * psize; 1823 1824 for_each_uvc_urb(uvc_urb, stream) { 1825 urb = usb_alloc_urb(npackets, gfp_flags); 1826 if (urb == NULL) { 1827 uvc_video_stop_transfer(stream, 1); 1828 return -ENOMEM; 1829 } 1830 1831 urb->dev = stream->dev->udev; 1832 urb->context = uvc_urb; 1833 urb->pipe = usb_rcvisocpipe(stream->dev->udev, 1834 ep->desc.bEndpointAddress); 1835 urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP; 1836 urb->transfer_dma = uvc_urb->dma; 1837 urb->interval = ep->desc.bInterval; 1838 urb->transfer_buffer = uvc_urb->buffer; 1839 urb->complete = uvc_video_complete; 1840 urb->number_of_packets = npackets; 1841 urb->transfer_buffer_length = size; 1842 1843 for (i = 0; i < npackets; ++i) { 1844 urb->iso_frame_desc[i].offset = i * psize; 1845 urb->iso_frame_desc[i].length = psize; 1846 } 1847 1848 uvc_urb->urb = urb; 1849 } 1850 1851 return 0; 1852} 1853 1854/* 1855 * Initialize bulk URBs and allocate transfer buffers. The packet size is 1856 * given by the endpoint. 1857 */ 1858static int uvc_init_video_bulk(struct uvc_streaming *stream, 1859 struct usb_host_endpoint *ep, gfp_t gfp_flags) 1860{ 1861 struct urb *urb; 1862 struct uvc_urb *uvc_urb; 1863 unsigned int npackets, pipe; 1864 u16 psize; 1865 u32 size; 1866 1867 psize = usb_endpoint_maxp(&ep->desc); 1868 size = stream->ctrl.dwMaxPayloadTransferSize; 1869 stream->bulk.max_payload_size = size; 1870 1871 npackets = uvc_alloc_urb_buffers(stream, size, psize, gfp_flags); 1872 if (npackets == 0) 1873 return -ENOMEM; 1874 1875 size = npackets * psize; 1876 1877 if (usb_endpoint_dir_in(&ep->desc)) 1878 pipe = usb_rcvbulkpipe(stream->dev->udev, 1879 ep->desc.bEndpointAddress); 1880 else 1881 pipe = usb_sndbulkpipe(stream->dev->udev, 1882 ep->desc.bEndpointAddress); 1883 1884 if (stream->type == V4L2_BUF_TYPE_VIDEO_OUTPUT) 1885 size = 0; 1886 1887 for_each_uvc_urb(uvc_urb, stream) { 1888 urb = usb_alloc_urb(0, gfp_flags); 1889 if (urb == NULL) { 1890 uvc_video_stop_transfer(stream, 1); 1891 return -ENOMEM; 1892 } 1893 1894 usb_fill_bulk_urb(urb, stream->dev->udev, pipe, uvc_urb->buffer, 1895 size, uvc_video_complete, uvc_urb); 1896 urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP; 1897 urb->transfer_dma = uvc_urb->dma; 1898 1899 uvc_urb->urb = urb; 1900 } 1901 1902 return 0; 1903} 1904 1905/* 1906 * Initialize isochronous/bulk URBs and allocate transfer buffers. 1907 */ 1908static int uvc_video_start_transfer(struct uvc_streaming *stream, 1909 gfp_t gfp_flags) 1910{ 1911 struct usb_interface *intf = stream->intf; 1912 struct usb_host_endpoint *ep; 1913 struct uvc_urb *uvc_urb; 1914 unsigned int i; 1915 int ret; 1916 1917 stream->sequence = -1; 1918 stream->last_fid = -1; 1919 stream->bulk.header_size = 0; 1920 stream->bulk.skip_payload = 0; 1921 stream->bulk.payload_size = 0; 1922 1923 uvc_video_stats_start(stream); 1924 1925 if (intf->num_altsetting > 1) { 1926 struct usb_host_endpoint *best_ep = NULL; 1927 unsigned int best_psize = UINT_MAX; 1928 unsigned int bandwidth; 1929 unsigned int altsetting; 1930 int intfnum = stream->intfnum; 1931 1932 /* Isochronous endpoint, select the alternate setting. */ 1933 bandwidth = stream->ctrl.dwMaxPayloadTransferSize; 1934 1935 if (bandwidth == 0) { 1936 uvc_dbg(stream->dev, VIDEO, 1937 "Device requested null bandwidth, defaulting to lowest\n"); 1938 bandwidth = 1; 1939 } else { 1940 uvc_dbg(stream->dev, VIDEO, 1941 "Device requested %u B/frame bandwidth\n", 1942 bandwidth); 1943 } 1944 1945 for (i = 0; i < intf->num_altsetting; ++i) { 1946 struct usb_host_interface *alts; 1947 unsigned int psize; 1948 1949 alts = &intf->altsetting[i]; 1950 ep = uvc_find_endpoint(alts, 1951 stream->header.bEndpointAddress); 1952 if (ep == NULL) 1953 continue; 1954 1955 /* Check if the bandwidth is high enough. */ 1956 psize = uvc_endpoint_max_bpi(stream->dev->udev, ep); 1957 if (psize >= bandwidth && psize <= best_psize) { 1958 altsetting = alts->desc.bAlternateSetting; 1959 best_psize = psize; 1960 best_ep = ep; 1961 } 1962 } 1963 1964 if (best_ep == NULL) { 1965 uvc_dbg(stream->dev, VIDEO, 1966 "No fast enough alt setting for requested bandwidth\n"); 1967 return -EIO; 1968 } 1969 1970 uvc_dbg(stream->dev, VIDEO, 1971 "Selecting alternate setting %u (%u B/frame bandwidth)\n", 1972 altsetting, best_psize); 1973 1974 /* 1975 * Some devices, namely the Logitech C910 and B910, are unable 1976 * to recover from a USB autosuspend, unless the alternate 1977 * setting of the streaming interface is toggled. 1978 */ 1979 if (stream->dev->quirks & UVC_QUIRK_WAKE_AUTOSUSPEND) { 1980 usb_set_interface(stream->dev->udev, intfnum, 1981 altsetting); 1982 usb_set_interface(stream->dev->udev, intfnum, 0); 1983 } 1984 1985 ret = usb_set_interface(stream->dev->udev, intfnum, altsetting); 1986 if (ret < 0) 1987 return ret; 1988 1989 ret = uvc_init_video_isoc(stream, best_ep, gfp_flags); 1990 } else { 1991 /* Bulk endpoint, proceed to URB initialization. */ 1992 ep = uvc_find_endpoint(&intf->altsetting[0], 1993 stream->header.bEndpointAddress); 1994 if (ep == NULL) 1995 return -EIO; 1996 1997 /* Reject broken descriptors. */ 1998 if (usb_endpoint_maxp(&ep->desc) == 0) 1999 return -EIO; 2000 2001 ret = uvc_init_video_bulk(stream, ep, gfp_flags); 2002 } 2003 2004 if (ret < 0) 2005 return ret; 2006 2007 /* Submit the URBs. */ 2008 for_each_uvc_urb(uvc_urb, stream) { 2009 ret = uvc_submit_urb(uvc_urb, gfp_flags); 2010 if (ret < 0) { 2011 dev_err(&stream->intf->dev, 2012 "Failed to submit URB %u (%d).\n", 2013 uvc_urb_index(uvc_urb), ret); 2014 uvc_video_stop_transfer(stream, 1); 2015 return ret; 2016 } 2017 } 2018 2019 /* 2020 * The Logitech C920 temporarily forgets that it should not be adjusting 2021 * Exposure Absolute during init so restore controls to stored values. 2022 */ 2023 if (stream->dev->quirks & UVC_QUIRK_RESTORE_CTRLS_ON_INIT) 2024 uvc_ctrl_restore_values(stream->dev); 2025 2026 return 0; 2027} 2028 2029/* -------------------------------------------------------------------------- 2030 * Suspend/resume 2031 */ 2032 2033/* 2034 * Stop streaming without disabling the video queue. 2035 * 2036 * To let userspace applications resume without trouble, we must not touch the 2037 * video buffers in any way. We mark the device as frozen to make sure the URB 2038 * completion handler won't try to cancel the queue when we kill the URBs. 2039 */ 2040int uvc_video_suspend(struct uvc_streaming *stream) 2041{ 2042 if (!uvc_queue_streaming(&stream->queue)) 2043 return 0; 2044 2045 stream->frozen = 1; 2046 uvc_video_stop_transfer(stream, 0); 2047 usb_set_interface(stream->dev->udev, stream->intfnum, 0); 2048 return 0; 2049} 2050 2051/* 2052 * Reconfigure the video interface and restart streaming if it was enabled 2053 * before suspend. 2054 * 2055 * If an error occurs, disable the video queue. This will wake all pending 2056 * buffers, making sure userspace applications are notified of the problem 2057 * instead of waiting forever. 2058 */ 2059int uvc_video_resume(struct uvc_streaming *stream, int reset) 2060{ 2061 int ret; 2062 2063 /* 2064 * If the bus has been reset on resume, set the alternate setting to 0. 2065 * This should be the default value, but some devices crash or otherwise 2066 * misbehave if they don't receive a SET_INTERFACE request before any 2067 * other video control request. 2068 */ 2069 if (reset) 2070 usb_set_interface(stream->dev->udev, stream->intfnum, 0); 2071 2072 stream->frozen = 0; 2073 2074 uvc_video_clock_reset(stream); 2075 2076 if (!uvc_queue_streaming(&stream->queue)) 2077 return 0; 2078 2079 ret = uvc_commit_video(stream, &stream->ctrl); 2080 if (ret < 0) 2081 return ret; 2082 2083 return uvc_video_start_transfer(stream, GFP_NOIO); 2084} 2085 2086/* ------------------------------------------------------------------------ 2087 * Video device 2088 */ 2089 2090/* 2091 * Initialize the UVC video device by switching to alternate setting 0 and 2092 * retrieve the default format. 2093 * 2094 * Some cameras (namely the Fuji Finepix) set the format and frame 2095 * indexes to zero. The UVC standard doesn't clearly make this a spec 2096 * violation, so try to silently fix the values if possible. 2097 * 2098 * This function is called before registering the device with V4L. 2099 */ 2100int uvc_video_init(struct uvc_streaming *stream) 2101{ 2102 struct uvc_streaming_control *probe = &stream->ctrl; 2103 const struct uvc_format *format = NULL; 2104 const struct uvc_frame *frame = NULL; 2105 struct uvc_urb *uvc_urb; 2106 unsigned int i; 2107 int ret; 2108 2109 if (stream->nformats == 0) { 2110 dev_info(&stream->intf->dev, 2111 "No supported video formats found.\n"); 2112 return -EINVAL; 2113 } 2114 2115 atomic_set(&stream->active, 0); 2116 2117 /* 2118 * Alternate setting 0 should be the default, yet the XBox Live Vision 2119 * Cam (and possibly other devices) crash or otherwise misbehave if 2120 * they don't receive a SET_INTERFACE request before any other video 2121 * control request. 2122 */ 2123 usb_set_interface(stream->dev->udev, stream->intfnum, 0); 2124 2125 /* 2126 * Set the streaming probe control with default streaming parameters 2127 * retrieved from the device. Webcams that don't support GET_DEF 2128 * requests on the probe control will just keep their current streaming 2129 * parameters. 2130 */ 2131 if (uvc_get_video_ctrl(stream, probe, 1, UVC_GET_DEF) == 0) 2132 uvc_set_video_ctrl(stream, probe, 1); 2133 2134 /* 2135 * Initialize the streaming parameters with the probe control current 2136 * value. This makes sure SET_CUR requests on the streaming commit 2137 * control will always use values retrieved from a successful GET_CUR 2138 * request on the probe control, as required by the UVC specification. 2139 */ 2140 ret = uvc_get_video_ctrl(stream, probe, 1, UVC_GET_CUR); 2141 2142 /* 2143 * Elgato Cam Link 4k can be in a stalled state if the resolution of 2144 * the external source has changed while the firmware initializes. 2145 * Once in this state, the device is useless until it receives a 2146 * USB reset. It has even been observed that the stalled state will 2147 * continue even after unplugging the device. 2148 */ 2149 if (ret == -EPROTO && 2150 usb_match_one_id(stream->dev->intf, &elgato_cam_link_4k)) { 2151 dev_err(&stream->intf->dev, "Elgato Cam Link 4K firmware crash detected\n"); 2152 dev_err(&stream->intf->dev, "Resetting the device, unplug and replug to recover\n"); 2153 usb_reset_device(stream->dev->udev); 2154 } 2155 2156 if (ret < 0) 2157 return ret; 2158 2159 /* 2160 * Check if the default format descriptor exists. Use the first 2161 * available format otherwise. 2162 */ 2163 for (i = stream->nformats; i > 0; --i) { 2164 format = &stream->formats[i-1]; 2165 if (format->index == probe->bFormatIndex) 2166 break; 2167 } 2168 2169 if (format->nframes == 0) { 2170 dev_info(&stream->intf->dev, 2171 "No frame descriptor found for the default format.\n"); 2172 return -EINVAL; 2173 } 2174 2175 /* 2176 * Zero bFrameIndex might be correct. Stream-based formats (including 2177 * MPEG-2 TS and DV) do not support frames but have a dummy frame 2178 * descriptor with bFrameIndex set to zero. If the default frame 2179 * descriptor is not found, use the first available frame. 2180 */ 2181 for (i = format->nframes; i > 0; --i) { 2182 frame = &format->frames[i-1]; 2183 if (frame->bFrameIndex == probe->bFrameIndex) 2184 break; 2185 } 2186 2187 probe->bFormatIndex = format->index; 2188 probe->bFrameIndex = frame->bFrameIndex; 2189 2190 stream->def_format = format; 2191 stream->cur_format = format; 2192 stream->cur_frame = frame; 2193 2194 /* Select the video decoding function */ 2195 if (stream->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) { 2196 if (stream->dev->quirks & UVC_QUIRK_BUILTIN_ISIGHT) 2197 stream->decode = uvc_video_decode_isight; 2198 else if (stream->intf->num_altsetting > 1) 2199 stream->decode = uvc_video_decode_isoc; 2200 else 2201 stream->decode = uvc_video_decode_bulk; 2202 } else { 2203 if (stream->intf->num_altsetting == 1) 2204 stream->decode = uvc_video_encode_bulk; 2205 else { 2206 dev_info(&stream->intf->dev, 2207 "Isochronous endpoints are not supported for video output devices.\n"); 2208 return -EINVAL; 2209 } 2210 } 2211 2212 /* Prepare asynchronous work items. */ 2213 for_each_uvc_urb(uvc_urb, stream) 2214 INIT_WORK(&uvc_urb->work, uvc_video_copy_data_work); 2215 2216 return 0; 2217} 2218 2219int uvc_video_start_streaming(struct uvc_streaming *stream) 2220{ 2221 int ret; 2222 2223 ret = uvc_video_clock_init(stream); 2224 if (ret < 0) 2225 return ret; 2226 2227 /* Commit the streaming parameters. */ 2228 ret = uvc_commit_video(stream, &stream->ctrl); 2229 if (ret < 0) 2230 goto error_commit; 2231 2232 ret = uvc_video_start_transfer(stream, GFP_KERNEL); 2233 if (ret < 0) 2234 goto error_video; 2235 2236 return 0; 2237 2238error_video: 2239 usb_set_interface(stream->dev->udev, stream->intfnum, 0); 2240error_commit: 2241 uvc_video_clock_cleanup(stream); 2242 2243 return ret; 2244} 2245 2246void uvc_video_stop_streaming(struct uvc_streaming *stream) 2247{ 2248 uvc_video_stop_transfer(stream, 1); 2249 2250 if (stream->intf->num_altsetting > 1) { 2251 usb_set_interface(stream->dev->udev, stream->intfnum, 0); 2252 } else { 2253 /* 2254 * UVC doesn't specify how to inform a bulk-based device 2255 * when the video stream is stopped. Windows sends a 2256 * CLEAR_FEATURE(HALT) request to the video streaming 2257 * bulk endpoint, mimic the same behaviour. 2258 */ 2259 unsigned int epnum = stream->header.bEndpointAddress 2260 & USB_ENDPOINT_NUMBER_MASK; 2261 unsigned int dir = stream->header.bEndpointAddress 2262 & USB_ENDPOINT_DIR_MASK; 2263 unsigned int pipe; 2264 2265 pipe = usb_sndbulkpipe(stream->dev->udev, epnum) | dir; 2266 usb_clear_halt(stream->dev->udev, pipe); 2267 } 2268 2269 uvc_video_clock_cleanup(stream); 2270} 2271