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