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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * uvc_video.c -- USB Video Class driver - Video handling4 *5 * Copyright (C) 2005-20106 * 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 <linux/unaligned.h>22 23#include <media/v4l2-common.h>24 25#include "uvcvideo.h"26 27/* ------------------------------------------------------------------------28 * UVC Controls29 */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 implemented121 * 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 byte146 * 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 the150 * 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: 67155 */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 to196 * compute the bandwidth on 16 bits and erroneously sign-extend it to197 * 32 bits, resulting in a huge bandwidth value. Detect and fix that198 * 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->dwFrameInterval211 : frame->dwFrameInterval[0];212 213 /*214 * Compute a bandwidth estimation by multiplying the frame215 * size by the number of video frames per second, divide the216 * result by the number of USB frames (or micro-frames for217 * high- and super-speed devices) per second and add the UVC218 * header size (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 use229 * maximum packet sizes lower than 1024 bytes to try and work230 * around the problem. According to measurements done on two231 * different camera models, the value is high enough to get most232 * resolutions working while not preventing two simultaneous233 * 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 depends245 * 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 else252 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 wCompQuality278 * 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 their290 * video probe control. Warn once and return, the caller will291 * 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 and334 * dwMaxPayloadTransferSize fields. Try to get the value from the335 * 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 values399 * according to its capabilities. However, some devices, namely the400 * first generation UVC Logitech webcams, don't implement the Video401 * Probe control properly, and just return the needed bandwidth. For402 * that reason, if the needed bandwidth exceeds the maximum available403 * 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 timestamps459 */460 461static inline ktime_t uvc_video_get_time(void)462{463 if (uvc_clock_param == CLOCK_MONOTONIC)464 return ktime_get();465 else466 return ktime_get_real();467}468 469static void uvc_video_clock_add_sample(struct uvc_clock *clock,470 const struct uvc_clock_sample *sample)471{472 unsigned long flags;473 474 /*475 * If we write new data on the position where we had the last476 * overflow, remove the overflow pointer. There is no SOF overflow477 * in the whole circular buffer.478 */479 if (clock->head == clock->last_sof_overflow)480 clock->last_sof_overflow = -1;481 482 spin_lock_irqsave(&clock->lock, flags);483 484 if (clock->count > 0 && clock->last_sof > sample->dev_sof) {485 /*486 * Remove data from the circular buffer that is older than the487 * last SOF overflow. We only support one SOF overflow per488 * circular buffer.489 */490 if (clock->last_sof_overflow != -1)491 clock->count = (clock->head - clock->last_sof_overflow492 + clock->size) % clock->size;493 clock->last_sof_overflow = clock->head;494 }495 496 /* Add sample. */497 clock->samples[clock->head] = *sample;498 clock->head = (clock->head + 1) % clock->size;499 clock->count = min(clock->count + 1, clock->size);500 501 spin_unlock_irqrestore(&clock->lock, flags);502}503 504static void505uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf,506 const u8 *data, int len)507{508 struct uvc_clock_sample sample;509 unsigned int header_size;510 bool has_pts = false;511 bool has_scr = false;512 513 switch (data[1] & (UVC_STREAM_PTS | UVC_STREAM_SCR)) {514 case UVC_STREAM_PTS | UVC_STREAM_SCR:515 header_size = 12;516 has_pts = true;517 has_scr = true;518 break;519 case UVC_STREAM_PTS:520 header_size = 6;521 has_pts = true;522 break;523 case UVC_STREAM_SCR:524 header_size = 8;525 has_scr = true;526 break;527 default:528 header_size = 2;529 break;530 }531 532 /* Check for invalid headers. */533 if (len < header_size)534 return;535 536 /*537 * Extract the timestamps:538 *539 * - store the frame PTS in the buffer structure540 * - if the SCR field is present, retrieve the host SOF counter and541 * kernel timestamps and store them with the SCR STC and SOF fields542 * in the ring buffer543 */544 if (has_pts && buf != NULL)545 buf->pts = get_unaligned_le32(&data[2]);546 547 if (!has_scr)548 return;549 550 /*551 * To limit the amount of data, drop SCRs with an SOF identical to the552 * previous one. This filtering is also needed to support UVC 1.5, where553 * all the data packets of the same frame contains the same SOF. In that554 * case only the first one will match the host_sof.555 */556 sample.dev_sof = get_unaligned_le16(&data[header_size - 2]);557 if (sample.dev_sof == stream->clock.last_sof)558 return;559 560 sample.dev_stc = get_unaligned_le32(&data[header_size - 6]);561 562 /*563 * STC (Source Time Clock) is the clock used by the camera. The UVC 1.5564 * standard states that it "must be captured when the first video data565 * of a video frame is put on the USB bus". This is generally understood566 * as requiring devices to clear the payload header's SCR bit before567 * the first packet containing video data.568 *569 * Most vendors follow that interpretation, but some (namely SunplusIT570 * on some devices) always set the `UVC_STREAM_SCR` bit, fill the SCR571 * field with 0's,and expect that the driver only processes the SCR if572 * there is data in the packet.573 *574 * Ignore all the hardware timestamp information if we haven't received575 * any data for this frame yet, the packet contains no data, and both576 * STC and SOF are zero. This heuristics should be safe on compliant577 * devices. This should be safe with compliant devices, as in the very578 * unlikely case where a UVC 1.1 device would send timing information579 * only before the first packet containing data, and both STC and SOF580 * happen to be zero for a particular frame, we would only miss one581 * clock sample from many and the clock recovery algorithm wouldn't582 * suffer from this condition.583 */584 if (buf && buf->bytesused == 0 && len == header_size &&585 sample.dev_stc == 0 && sample.dev_sof == 0)586 return;587 588 sample.host_sof = usb_get_current_frame_number(stream->dev->udev);589 590 /*591 * On some devices, like the Logitech C922, the device SOF does not run592 * at a stable rate of 1kHz. For those devices use the host SOF instead.593 * In the tests performed so far, this improves the timestamp precision.594 * This is probably explained by a small packet handling jitter from the595 * host, but the exact reason hasn't been fully determined.596 */597 if (stream->dev->quirks & UVC_QUIRK_INVALID_DEVICE_SOF)598 sample.dev_sof = sample.host_sof;599 600 sample.host_time = uvc_video_get_time();601 602 /*603 * The UVC specification allows device implementations that can't obtain604 * the USB frame number to keep their own frame counters as long as they605 * match the size and frequency of the frame number associated with USB606 * SOF tokens. The SOF values sent by such devices differ from the USB607 * SOF tokens by a fixed offset that needs to be estimated and accounted608 * for to make timestamp recovery as accurate as possible.609 *610 * The offset is estimated the first time a device SOF value is received611 * as the difference between the host and device SOF values. As the two612 * SOF values can differ slightly due to transmission delays, consider613 * that the offset is null if the difference is not higher than 10 ms614 * (negative differences can not happen and are thus considered as an615 * offset). The video commit control wDelay field should be used to616 * compute a dynamic threshold instead of using a fixed 10 ms value, but617 * devices don't report reliable wDelay values.618 *619 * See uvc_video_clock_host_sof() for an explanation regarding why only620 * the 8 LSBs of the delta are kept.621 */622 if (stream->clock.sof_offset == (u16)-1) {623 u16 delta_sof = (sample.host_sof - sample.dev_sof) & 255;624 if (delta_sof >= 10)625 stream->clock.sof_offset = delta_sof;626 else627 stream->clock.sof_offset = 0;628 }629 630 sample.dev_sof = (sample.dev_sof + stream->clock.sof_offset) & 2047;631 uvc_video_clock_add_sample(&stream->clock, &sample);632 stream->clock.last_sof = sample.dev_sof;633}634 635static void uvc_video_clock_reset(struct uvc_clock *clock)636{637 clock->head = 0;638 clock->count = 0;639 clock->last_sof = -1;640 clock->last_sof_overflow = -1;641 clock->sof_offset = -1;642}643 644static int uvc_video_clock_init(struct uvc_clock *clock)645{646 spin_lock_init(&clock->lock);647 clock->size = 32;648 649 clock->samples = kmalloc_array(clock->size, sizeof(*clock->samples),650 GFP_KERNEL);651 if (clock->samples == NULL)652 return -ENOMEM;653 654 uvc_video_clock_reset(clock);655 656 return 0;657}658 659static void uvc_video_clock_cleanup(struct uvc_clock *clock)660{661 kfree(clock->samples);662 clock->samples = NULL;663}664 665/*666 * uvc_video_clock_host_sof - Return the host SOF value for a clock sample667 *668 * Host SOF counters reported by usb_get_current_frame_number() usually don't669 * cover the whole 11-bits SOF range (0-2047) but are limited to the HCI frame670 * schedule window. They can be limited to 8, 9 or 10 bits depending on the host671 * controller and its configuration.672 *673 * We thus need to recover the SOF value corresponding to the host frame number.674 * As the device and host frame numbers are sampled in a short interval, the675 * difference between their values should be equal to a small delta plus an676 * integer multiple of 256 caused by the host frame number limited precision.677 *678 * To obtain the recovered host SOF value, compute the small delta by masking679 * the high bits of the host frame counter and device SOF difference and add it680 * to the device SOF value.681 */682static u16 uvc_video_clock_host_sof(const struct uvc_clock_sample *sample)683{684 /* The delta value can be negative. */685 s8 delta_sof;686 687 delta_sof = (sample->host_sof - sample->dev_sof) & 255;688 689 return (sample->dev_sof + delta_sof) & 2047;690}691 692/*693 * uvc_video_clock_update - Update the buffer timestamp694 *695 * This function converts the buffer PTS timestamp to the host clock domain by696 * going through the USB SOF clock domain and stores the result in the V4L2697 * buffer timestamp field.698 *699 * The relationship between the device clock and the host clock isn't known.700 * However, the device and the host share the common USB SOF clock which can be701 * used to recover that relationship.702 *703 * The relationship between the device clock and the USB SOF clock is considered704 * to be linear over the clock samples sliding window and is given by705 *706 * SOF = m * PTS + p707 *708 * Several methods to compute the slope (m) and intercept (p) can be used. As709 * the clock drift should be small compared to the sliding window size, we710 * assume that the line that goes through the points at both ends of the window711 * is a good approximation. Naming those points P1 and P2, we get712 *713 * SOF = (SOF2 - SOF1) / (STC2 - STC1) * PTS714 * + (SOF1 * STC2 - SOF2 * STC1) / (STC2 - STC1)715 *716 * or717 *718 * SOF = ((SOF2 - SOF1) * PTS + SOF1 * STC2 - SOF2 * STC1) / (STC2 - STC1) (1)719 *720 * to avoid losing precision in the division. Similarly, the host timestamp is721 * computed with722 *723 * TS = ((TS2 - TS1) * SOF + TS1 * SOF2 - TS2 * SOF1) / (SOF2 - SOF1) (2)724 *725 * SOF values are coded on 11 bits by USB. We extend their precision with 16726 * decimal bits, leading to a 11.16 coding.727 *728 * TODO: To avoid surprises with device clock values, PTS/STC timestamps should729 * be normalized using the nominal device clock frequency reported through the730 * UVC descriptors.731 *732 * Both the PTS/STC and SOF counters roll over, after a fixed but device733 * specific amount of time for PTS/STC and after 2048ms for SOF. As long as the734 * sliding window size is smaller than the rollover period, differences computed735 * on unsigned integers will produce the correct result. However, the p term in736 * the linear relations will be miscomputed.737 *738 * To fix the issue, we subtract a constant from the PTS and STC values to bring739 * PTS to half the 32 bit STC range. The sliding window STC values then fit into740 * the 32 bit range without any rollover.741 *742 * Similarly, we add 2048 to the device SOF values to make sure that the SOF743 * computed by (1) will never be smaller than 0. This offset is then compensated744 * by adding 2048 to the SOF values used in (2). However, this doesn't prevent745 * rollovers between (1) and (2): the SOF value computed by (1) can be slightly746 * lower than 4096, and the host SOF counters can have rolled over to 2048. This747 * case is handled by subtracting 2048 from the SOF value if it exceeds the host748 * SOF value at the end of the sliding window.749 *750 * Finally we subtract a constant from the host timestamps to bring the first751 * timestamp of the sliding window to 1s.752 */753void uvc_video_clock_update(struct uvc_streaming *stream,754 struct vb2_v4l2_buffer *vbuf,755 struct uvc_buffer *buf)756{757 struct uvc_clock *clock = &stream->clock;758 struct uvc_clock_sample *first;759 struct uvc_clock_sample *last;760 unsigned long flags;761 u64 timestamp;762 u32 delta_stc;763 u32 y1;764 u32 x1, x2;765 u32 mean;766 u32 sof;767 u64 y, y2;768 769 if (!uvc_hw_timestamps_param)770 return;771 772 /*773 * We will get called from __vb2_queue_cancel() if there are buffers774 * done but not dequeued by the user, but the sample array has already775 * been released at that time. Just bail out in that case.776 */777 if (!clock->samples)778 return;779 780 spin_lock_irqsave(&clock->lock, flags);781 782 if (clock->count < 2)783 goto done;784 785 first = &clock->samples[(clock->head - clock->count + clock->size) % clock->size];786 last = &clock->samples[(clock->head - 1 + clock->size) % clock->size];787 788 /* First step, PTS to SOF conversion. */789 delta_stc = buf->pts - (1UL << 31);790 x1 = first->dev_stc - delta_stc;791 x2 = last->dev_stc - delta_stc;792 if (x1 == x2)793 goto done;794 795 y1 = (first->dev_sof + 2048) << 16;796 y2 = (last->dev_sof + 2048) << 16;797 if (y2 < y1)798 y2 += 2048 << 16;799 800 /*801 * Have at least 1/4 of a second of timestamps before we802 * try to do any calculation. Otherwise we do not have enough803 * precision. This value was determined by running Android CTS804 * on different devices.805 *806 * dev_sof runs at 1KHz, and we have a fixed point precision of807 * 16 bits.808 */809 if ((y2 - y1) < ((1000 / 4) << 16))810 goto done;811 812 y = (u64)(y2 - y1) * (1ULL << 31) + (u64)y1 * (u64)x2813 - (u64)y2 * (u64)x1;814 y = div_u64(y, x2 - x1);815 816 sof = y;817 818 uvc_dbg(stream->dev, CLOCK,819 "%s: PTS %u y %llu.%06llu SOF %u.%06llu (x1 %u x2 %u y1 %u y2 %llu SOF offset %u)\n",820 stream->dev->name, buf->pts,821 y >> 16, div_u64((y & 0xffff) * 1000000, 65536),822 sof >> 16, div_u64(((u64)sof & 0xffff) * 1000000LLU, 65536),823 x1, x2, y1, y2, clock->sof_offset);824 825 /* Second step, SOF to host clock conversion. */826 x1 = (uvc_video_clock_host_sof(first) + 2048) << 16;827 x2 = (uvc_video_clock_host_sof(last) + 2048) << 16;828 if (x2 < x1)829 x2 += 2048 << 16;830 if (x1 == x2)831 goto done;832 833 y1 = NSEC_PER_SEC;834 y2 = ktime_to_ns(ktime_sub(last->host_time, first->host_time)) + y1;835 836 /*837 * Interpolated and host SOF timestamps can wrap around at slightly838 * different times. Handle this by adding or removing 2048 to or from839 * the computed SOF value to keep it close to the SOF samples mean840 * value.841 */842 mean = (x1 + x2) / 2;843 if (mean - (1024 << 16) > sof)844 sof += 2048 << 16;845 else if (sof > mean + (1024 << 16))846 sof -= 2048 << 16;847 848 y = (u64)(y2 - y1) * (u64)sof + (u64)y1 * (u64)x2849 - (u64)y2 * (u64)x1;850 y = div_u64(y, x2 - x1);851 852 timestamp = ktime_to_ns(first->host_time) + y - y1;853 854 uvc_dbg(stream->dev, CLOCK,855 "%s: SOF %u.%06llu y %llu ts %llu buf ts %llu (x1 %u/%u/%u x2 %u/%u/%u y1 %u y2 %llu)\n",856 stream->dev->name,857 sof >> 16, div_u64(((u64)sof & 0xffff) * 1000000LLU, 65536),858 y, timestamp, vbuf->vb2_buf.timestamp,859 x1, first->host_sof, first->dev_sof,860 x2, last->host_sof, last->dev_sof, y1, y2);861 862 /* Update the V4L2 buffer. */863 vbuf->vb2_buf.timestamp = timestamp;864 865done:866 spin_unlock_irqrestore(&clock->lock, flags);867}868 869/* ------------------------------------------------------------------------870 * Stream statistics871 */872 873static void uvc_video_stats_decode(struct uvc_streaming *stream,874 const u8 *data, int len)875{876 unsigned int header_size;877 bool has_pts = false;878 bool has_scr = false;879 u16 scr_sof;880 u32 scr_stc;881 u32 pts;882 883 if (stream->stats.stream.nb_frames == 0 &&884 stream->stats.frame.nb_packets == 0)885 stream->stats.stream.start_ts = ktime_get();886 887 switch (data[1] & (UVC_STREAM_PTS | UVC_STREAM_SCR)) {888 case UVC_STREAM_PTS | UVC_STREAM_SCR:889 header_size = 12;890 has_pts = true;891 has_scr = true;892 break;893 case UVC_STREAM_PTS:894 header_size = 6;895 has_pts = true;896 break;897 case UVC_STREAM_SCR:898 header_size = 8;899 has_scr = true;900 break;901 default:902 header_size = 2;903 break;904 }905 906 /* Check for invalid headers. */907 if (len < header_size || data[0] < header_size) {908 stream->stats.frame.nb_invalid++;909 return;910 }911 912 /* Extract the timestamps. */913 if (has_pts)914 pts = get_unaligned_le32(&data[2]);915 916 if (has_scr) {917 scr_stc = get_unaligned_le32(&data[header_size - 6]);918 scr_sof = get_unaligned_le16(&data[header_size - 2]);919 }920 921 /* Is PTS constant through the whole frame ? */922 if (has_pts && stream->stats.frame.nb_pts) {923 if (stream->stats.frame.pts != pts) {924 stream->stats.frame.nb_pts_diffs++;925 stream->stats.frame.last_pts_diff =926 stream->stats.frame.nb_packets;927 }928 }929 930 if (has_pts) {931 stream->stats.frame.nb_pts++;932 stream->stats.frame.pts = pts;933 }934 935 /*936 * Do all frames have a PTS in their first non-empty packet, or before937 * their first empty packet ?938 */939 if (stream->stats.frame.size == 0) {940 if (len > header_size)941 stream->stats.frame.has_initial_pts = has_pts;942 if (len == header_size && has_pts)943 stream->stats.frame.has_early_pts = true;944 }945 946 /* Do the SCR.STC and SCR.SOF fields vary through the frame ? */947 if (has_scr && stream->stats.frame.nb_scr) {948 if (stream->stats.frame.scr_stc != scr_stc)949 stream->stats.frame.nb_scr_diffs++;950 }951 952 if (has_scr) {953 /* Expand the SOF counter to 32 bits and store its value. */954 if (stream->stats.stream.nb_frames > 0 ||955 stream->stats.frame.nb_scr > 0)956 stream->stats.stream.scr_sof_count +=957 (scr_sof - stream->stats.stream.scr_sof) % 2048;958 stream->stats.stream.scr_sof = scr_sof;959 960 stream->stats.frame.nb_scr++;961 stream->stats.frame.scr_stc = scr_stc;962 stream->stats.frame.scr_sof = scr_sof;963 964 if (scr_sof < stream->stats.stream.min_sof)965 stream->stats.stream.min_sof = scr_sof;966 if (scr_sof > stream->stats.stream.max_sof)967 stream->stats.stream.max_sof = scr_sof;968 }969 970 /* Record the first non-empty packet number. */971 if (stream->stats.frame.size == 0 && len > header_size)972 stream->stats.frame.first_data = stream->stats.frame.nb_packets;973 974 /* Update the frame size. */975 stream->stats.frame.size += len - header_size;976 977 /* Update the packets counters. */978 stream->stats.frame.nb_packets++;979 if (len <= header_size)980 stream->stats.frame.nb_empty++;981 982 if (data[1] & UVC_STREAM_ERR)983 stream->stats.frame.nb_errors++;984}985 986static void uvc_video_stats_update(struct uvc_streaming *stream)987{988 struct uvc_stats_frame *frame = &stream->stats.frame;989 990 uvc_dbg(stream->dev, STATS,991 "frame %u stats: %u/%u/%u packets, %u/%u/%u pts (%searly %sinitial), %u/%u scr, last pts/stc/sof %u/%u/%u\n",992 stream->sequence, frame->first_data,993 frame->nb_packets - frame->nb_empty, frame->nb_packets,994 frame->nb_pts_diffs, frame->last_pts_diff, frame->nb_pts,995 frame->has_early_pts ? "" : "!",996 frame->has_initial_pts ? "" : "!",997 frame->nb_scr_diffs, frame->nb_scr,998 frame->pts, frame->scr_stc, frame->scr_sof);999 1000 stream->stats.stream.nb_frames++;1001 stream->stats.stream.nb_packets += stream->stats.frame.nb_packets;1002 stream->stats.stream.nb_empty += stream->stats.frame.nb_empty;1003 stream->stats.stream.nb_errors += stream->stats.frame.nb_errors;1004 stream->stats.stream.nb_invalid += stream->stats.frame.nb_invalid;1005 1006 if (frame->has_early_pts)1007 stream->stats.stream.nb_pts_early++;1008 if (frame->has_initial_pts)1009 stream->stats.stream.nb_pts_initial++;1010 if (frame->last_pts_diff <= frame->first_data)1011 stream->stats.stream.nb_pts_constant++;1012 if (frame->nb_scr >= frame->nb_packets - frame->nb_empty)1013 stream->stats.stream.nb_scr_count_ok++;1014 if (frame->nb_scr_diffs + 1 == frame->nb_scr)1015 stream->stats.stream.nb_scr_diffs_ok++;1016 1017 memset(&stream->stats.frame, 0, sizeof(stream->stats.frame));1018}1019 1020size_t uvc_video_stats_dump(struct uvc_streaming *stream, char *buf,1021 size_t size)1022{1023 unsigned int scr_sof_freq;1024 unsigned int duration;1025 size_t count = 0;1026 1027 /*1028 * Compute the SCR.SOF frequency estimate. At the nominal 1kHz SOF1029 * frequency this will not overflow before more than 1h.1030 */1031 duration = ktime_ms_delta(stream->stats.stream.stop_ts,1032 stream->stats.stream.start_ts);1033 if (duration != 0)1034 scr_sof_freq = stream->stats.stream.scr_sof_count * 10001035 / duration;1036 else1037 scr_sof_freq = 0;1038 1039 count += scnprintf(buf + count, size - count,1040 "frames: %u\npackets: %u\nempty: %u\n"1041 "errors: %u\ninvalid: %u\n",1042 stream->stats.stream.nb_frames,1043 stream->stats.stream.nb_packets,1044 stream->stats.stream.nb_empty,1045 stream->stats.stream.nb_errors,1046 stream->stats.stream.nb_invalid);1047 count += scnprintf(buf + count, size - count,1048 "pts: %u early, %u initial, %u ok\n",1049 stream->stats.stream.nb_pts_early,1050 stream->stats.stream.nb_pts_initial,1051 stream->stats.stream.nb_pts_constant);1052 count += scnprintf(buf + count, size - count,1053 "scr: %u count ok, %u diff ok\n",1054 stream->stats.stream.nb_scr_count_ok,1055 stream->stats.stream.nb_scr_diffs_ok);1056 count += scnprintf(buf + count, size - count,1057 "sof: %u <= sof <= %u, freq %u.%03u kHz\n",1058 stream->stats.stream.min_sof,1059 stream->stats.stream.max_sof,1060 scr_sof_freq / 1000, scr_sof_freq % 1000);1061 1062 return count;1063}1064 1065static void uvc_video_stats_start(struct uvc_streaming *stream)1066{1067 memset(&stream->stats, 0, sizeof(stream->stats));1068 stream->stats.stream.min_sof = 2048;1069}1070 1071static void uvc_video_stats_stop(struct uvc_streaming *stream)1072{1073 stream->stats.stream.stop_ts = ktime_get();1074}1075 1076/* ------------------------------------------------------------------------1077 * Video codecs1078 */1079 1080/*1081 * Video payload decoding is handled by uvc_video_decode_start(),1082 * uvc_video_decode_data() and uvc_video_decode_end().1083 *1084 * uvc_video_decode_start is called with URB data at the start of a bulk or1085 * isochronous payload. It processes header data and returns the header size1086 * in bytes if successful. If an error occurs, it returns a negative error1087 * code. The following error codes have special meanings.1088 *1089 * - EAGAIN informs the caller that the current video buffer should be marked1090 * as done, and that the function should be called again with the same data1091 * and a new video buffer. This is used when end of frame conditions can be1092 * reliably detected at the beginning of the next frame only.1093 *1094 * If an error other than -EAGAIN is returned, the caller will drop the current1095 * payload. No call to uvc_video_decode_data and uvc_video_decode_end will be1096 * made until the next payload. -ENODATA can be used to drop the current1097 * payload if no other error code is appropriate.1098 *1099 * uvc_video_decode_data is called for every URB with URB data. It copies the1100 * data to the video buffer.1101 *1102 * uvc_video_decode_end is called with header data at the end of a bulk or1103 * isochronous payload. It performs any additional header data processing and1104 * returns 0 or a negative error code if an error occurred. As header data have1105 * already been processed by uvc_video_decode_start, this functions isn't1106 * required to perform sanity checks a second time.1107 *1108 * For isochronous transfers where a payload is always transferred in a single1109 * URB, the three functions will be called in a row.1110 *1111 * To let the decoder process header data and update its internal state even1112 * when no video buffer is available, uvc_video_decode_start must be prepared1113 * to be called with a NULL buf parameter. uvc_video_decode_data and1114 * uvc_video_decode_end will never be called with a NULL buffer.1115 */1116static int uvc_video_decode_start(struct uvc_streaming *stream,1117 struct uvc_buffer *buf, const u8 *data, int len)1118{1119 u8 fid;1120 1121 /*1122 * Sanity checks:1123 * - packet must be at least 2 bytes long1124 * - bHeaderLength value must be at least 2 bytes (see above)1125 * - bHeaderLength value can't be larger than the packet size.1126 */1127 if (len < 2 || data[0] < 2 || data[0] > len) {1128 stream->stats.frame.nb_invalid++;1129 return -EINVAL;1130 }1131 1132 fid = data[1] & UVC_STREAM_FID;1133 1134 /*1135 * Increase the sequence number regardless of any buffer states, so1136 * that discontinuous sequence numbers always indicate lost frames.1137 */1138 if (stream->last_fid != fid) {1139 stream->sequence++;1140 if (stream->sequence)1141 uvc_video_stats_update(stream);1142 }1143 1144 uvc_video_clock_decode(stream, buf, data, len);1145 uvc_video_stats_decode(stream, data, len);1146 1147 /*1148 * Store the payload FID bit and return immediately when the buffer is1149 * NULL.1150 */1151 if (buf == NULL) {1152 stream->last_fid = fid;1153 return -ENODATA;1154 }1155 1156 /* Mark the buffer as bad if the error bit is set. */1157 if (data[1] & UVC_STREAM_ERR) {1158 uvc_dbg(stream->dev, FRAME,1159 "Marking buffer as bad (error bit set)\n");1160 buf->error = 1;1161 }1162 1163 /*1164 * Synchronize to the input stream by waiting for the FID bit to be1165 * toggled when the buffer state is not UVC_BUF_STATE_ACTIVE.1166 * stream->last_fid is initialized to -1, so the first isochronous1167 * frame will always be in sync.1168 *1169 * If the device doesn't toggle the FID bit, invert stream->last_fid1170 * when the EOF bit is set to force synchronisation on the next packet.1171 */1172 if (buf->state != UVC_BUF_STATE_ACTIVE) {1173 if (fid == stream->last_fid) {1174 uvc_dbg(stream->dev, FRAME,1175 "Dropping payload (out of sync)\n");1176 if ((stream->dev->quirks & UVC_QUIRK_STREAM_NO_FID) &&1177 (data[1] & UVC_STREAM_EOF))1178 stream->last_fid ^= UVC_STREAM_FID;1179 return -ENODATA;1180 }1181 1182 buf->buf.field = V4L2_FIELD_NONE;1183 buf->buf.sequence = stream->sequence;1184 buf->buf.vb2_buf.timestamp = ktime_to_ns(uvc_video_get_time());1185 1186 /* TODO: Handle PTS and SCR. */1187 buf->state = UVC_BUF_STATE_ACTIVE;1188 }1189 1190 /*1191 * Mark the buffer as done if we're at the beginning of a new frame.1192 * End of frame detection is better implemented by checking the EOF1193 * bit (FID bit toggling is delayed by one frame compared to the EOF1194 * bit), but some devices don't set the bit at end of frame (and the1195 * last payload can be lost anyway). We thus must check if the FID has1196 * been toggled.1197 *1198 * stream->last_fid is initialized to -1, so the first isochronous1199 * frame will never trigger an end of frame detection.1200 *1201 * Empty buffers (bytesused == 0) don't trigger end of frame detection1202 * as it doesn't make sense to return an empty buffer. This also1203 * avoids detecting end of frame conditions at FID toggling if the1204 * previous payload had the EOF bit set.1205 */1206 if (fid != stream->last_fid && buf->bytesused != 0) {1207 uvc_dbg(stream->dev, FRAME,1208 "Frame complete (FID bit toggled)\n");1209 buf->state = UVC_BUF_STATE_READY;1210 return -EAGAIN;1211 }1212 1213 stream->last_fid = fid;1214 1215 return data[0];1216}1217 1218static inline enum dma_data_direction uvc_stream_dir(1219 struct uvc_streaming *stream)1220{1221 if (stream->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)1222 return DMA_FROM_DEVICE;1223 else1224 return DMA_TO_DEVICE;1225}1226 1227static inline struct device *uvc_stream_to_dmadev(struct uvc_streaming *stream)1228{1229 return bus_to_hcd(stream->dev->udev->bus)->self.sysdev;1230}1231 1232static int uvc_submit_urb(struct uvc_urb *uvc_urb, gfp_t mem_flags)1233{1234 /* Sync DMA. */1235 dma_sync_sgtable_for_device(uvc_stream_to_dmadev(uvc_urb->stream),1236 uvc_urb->sgt,1237 uvc_stream_dir(uvc_urb->stream));1238 return usb_submit_urb(uvc_urb->urb, mem_flags);1239}1240 1241/*1242 * uvc_video_decode_data_work: Asynchronous memcpy processing1243 *1244 * Copy URB data to video buffers in process context, releasing buffer1245 * references and requeuing the URB when done.1246 */1247static void uvc_video_copy_data_work(struct work_struct *work)1248{1249 struct uvc_urb *uvc_urb = container_of(work, struct uvc_urb, work);1250 unsigned int i;1251 int ret;1252 1253 for (i = 0; i < uvc_urb->async_operations; i++) {1254 struct uvc_copy_op *op = &uvc_urb->copy_operations[i];1255 1256 memcpy(op->dst, op->src, op->len);1257 1258 /* Release reference taken on this buffer. */1259 uvc_queue_buffer_release(op->buf);1260 }1261 1262 ret = uvc_submit_urb(uvc_urb, GFP_KERNEL);1263 if (ret < 0)1264 dev_err(&uvc_urb->stream->intf->dev,1265 "Failed to resubmit video URB (%d).\n", ret);1266}1267 1268static void uvc_video_decode_data(struct uvc_urb *uvc_urb,1269 struct uvc_buffer *buf, const u8 *data, int len)1270{1271 unsigned int active_op = uvc_urb->async_operations;1272 struct uvc_copy_op *op = &uvc_urb->copy_operations[active_op];1273 unsigned int maxlen;1274 1275 if (len <= 0)1276 return;1277 1278 maxlen = buf->length - buf->bytesused;1279 1280 /* Take a buffer reference for async work. */1281 kref_get(&buf->ref);1282 1283 op->buf = buf;1284 op->src = data;1285 op->dst = buf->mem + buf->bytesused;1286 op->len = min_t(unsigned int, len, maxlen);1287 1288 buf->bytesused += op->len;1289 1290 /* Complete the current frame if the buffer size was exceeded. */1291 if (len > maxlen) {1292 uvc_dbg(uvc_urb->stream->dev, FRAME,1293 "Frame complete (overflow)\n");1294 buf->error = 1;1295 buf->state = UVC_BUF_STATE_READY;1296 }1297 1298 uvc_urb->async_operations++;1299}1300 1301static void uvc_video_decode_end(struct uvc_streaming *stream,1302 struct uvc_buffer *buf, const u8 *data, int len)1303{1304 /* Mark the buffer as done if the EOF marker is set. */1305 if (data[1] & UVC_STREAM_EOF && buf->bytesused != 0) {1306 uvc_dbg(stream->dev, FRAME, "Frame complete (EOF found)\n");1307 if (data[0] == len)1308 uvc_dbg(stream->dev, FRAME, "EOF in empty payload\n");1309 buf->state = UVC_BUF_STATE_READY;1310 if (stream->dev->quirks & UVC_QUIRK_STREAM_NO_FID)1311 stream->last_fid ^= UVC_STREAM_FID;1312 }1313}1314 1315/*1316 * Video payload encoding is handled by uvc_video_encode_header() and1317 * uvc_video_encode_data(). Only bulk transfers are currently supported.1318 *1319 * uvc_video_encode_header is called at the start of a payload. It adds header1320 * data to the transfer buffer and returns the header size. As the only known1321 * UVC output device transfers a whole frame in a single payload, the EOF bit1322 * is always set in the header.1323 *1324 * uvc_video_encode_data is called for every URB and copies the data from the1325 * video buffer to the transfer buffer.1326 */1327static int uvc_video_encode_header(struct uvc_streaming *stream,1328 struct uvc_buffer *buf, u8 *data, int len)1329{1330 data[0] = 2; /* Header length */1331 data[1] = UVC_STREAM_EOH | UVC_STREAM_EOF1332 | (stream->last_fid & UVC_STREAM_FID);1333 return 2;1334}1335 1336static int uvc_video_encode_data(struct uvc_streaming *stream,1337 struct uvc_buffer *buf, u8 *data, int len)1338{1339 struct uvc_video_queue *queue = &stream->queue;1340 unsigned int nbytes;1341 void *mem;1342 1343 /* Copy video data to the URB buffer. */1344 mem = buf->mem + queue->buf_used;1345 nbytes = min((unsigned int)len, buf->bytesused - queue->buf_used);1346 nbytes = min(stream->bulk.max_payload_size - stream->bulk.payload_size,1347 nbytes);1348 memcpy(data, mem, nbytes);1349 1350 queue->buf_used += nbytes;1351 1352 return nbytes;1353}1354 1355/* ------------------------------------------------------------------------1356 * Metadata1357 */1358 1359/*1360 * Additionally to the payload headers we also want to provide the user with USB1361 * Frame Numbers and system time values. The resulting buffer is thus composed1362 * of blocks, containing a 64-bit timestamp in nanoseconds, a 16-bit USB Frame1363 * Number, and a copy of the payload header.1364 *1365 * Ideally we want to capture all payload headers for each frame. However, their1366 * number is unknown and unbound. We thus drop headers that contain no vendor1367 * data and that either contain no SCR value or an SCR value identical to the1368 * previous header.1369 */1370static void uvc_video_decode_meta(struct uvc_streaming *stream,1371 struct uvc_buffer *meta_buf,1372 const u8 *mem, unsigned int length)1373{1374 struct uvc_meta_buf *meta;1375 size_t len_std = 2;1376 bool has_pts, has_scr;1377 unsigned long flags;1378 unsigned int sof;1379 ktime_t time;1380 const u8 *scr;1381 1382 if (!meta_buf || length == 2)1383 return;1384 1385 if (meta_buf->length - meta_buf->bytesused <1386 length + sizeof(meta->ns) + sizeof(meta->sof)) {1387 meta_buf->error = 1;1388 return;1389 }1390 1391 has_pts = mem[1] & UVC_STREAM_PTS;1392 has_scr = mem[1] & UVC_STREAM_SCR;1393 1394 if (has_pts) {1395 len_std += 4;1396 scr = mem + 6;1397 } else {1398 scr = mem + 2;1399 }1400 1401 if (has_scr)1402 len_std += 6;1403 1404 if (stream->meta.format == V4L2_META_FMT_UVC)1405 length = len_std;1406 1407 if (length == len_std && (!has_scr ||1408 !memcmp(scr, stream->clock.last_scr, 6)))1409 return;1410 1411 meta = (struct uvc_meta_buf *)((u8 *)meta_buf->mem + meta_buf->bytesused);1412 local_irq_save(flags);1413 time = uvc_video_get_time();1414 sof = usb_get_current_frame_number(stream->dev->udev);1415 local_irq_restore(flags);1416 put_unaligned(ktime_to_ns(time), &meta->ns);1417 put_unaligned(sof, &meta->sof);1418 1419 if (has_scr)1420 memcpy(stream->clock.last_scr, scr, 6);1421 1422 meta->length = mem[0];1423 meta->flags = mem[1];1424 memcpy(meta->buf, &mem[2], length - 2);1425 meta_buf->bytesused += length + sizeof(meta->ns) + sizeof(meta->sof);1426 1427 uvc_dbg(stream->dev, FRAME,1428 "%s(): t-sys %lluns, SOF %u, len %u, flags 0x%x, PTS %u, STC %u frame SOF %u\n",1429 __func__, ktime_to_ns(time), meta->sof, meta->length,1430 meta->flags,1431 has_pts ? *(u32 *)meta->buf : 0,1432 has_scr ? *(u32 *)scr : 0,1433 has_scr ? *(u32 *)(scr + 4) & 0x7ff : 0);1434}1435 1436/* ------------------------------------------------------------------------1437 * URB handling1438 */1439 1440/*1441 * Set error flag for incomplete buffer.1442 */1443static void uvc_video_validate_buffer(const struct uvc_streaming *stream,1444 struct uvc_buffer *buf)1445{1446 if (stream->ctrl.dwMaxVideoFrameSize != buf->bytesused &&1447 !(stream->cur_format->flags & UVC_FMT_FLAG_COMPRESSED))1448 buf->error = 1;1449}1450 1451/*1452 * Completion handler for video URBs.1453 */1454 1455static void uvc_video_next_buffers(struct uvc_streaming *stream,1456 struct uvc_buffer **video_buf, struct uvc_buffer **meta_buf)1457{1458 uvc_video_validate_buffer(stream, *video_buf);1459 1460 if (*meta_buf) {1461 struct vb2_v4l2_buffer *vb2_meta = &(*meta_buf)->buf;1462 const struct vb2_v4l2_buffer *vb2_video = &(*video_buf)->buf;1463 1464 vb2_meta->sequence = vb2_video->sequence;1465 vb2_meta->field = vb2_video->field;1466 vb2_meta->vb2_buf.timestamp = vb2_video->vb2_buf.timestamp;1467 1468 (*meta_buf)->state = UVC_BUF_STATE_READY;1469 if (!(*meta_buf)->error)1470 (*meta_buf)->error = (*video_buf)->error;1471 *meta_buf = uvc_queue_next_buffer(&stream->meta.queue,1472 *meta_buf);1473 }1474 *video_buf = uvc_queue_next_buffer(&stream->queue, *video_buf);1475}1476 1477static void uvc_video_decode_isoc(struct uvc_urb *uvc_urb,1478 struct uvc_buffer *buf, struct uvc_buffer *meta_buf)1479{1480 struct urb *urb = uvc_urb->urb;1481 struct uvc_streaming *stream = uvc_urb->stream;1482 u8 *mem;1483 int ret, i;1484 1485 for (i = 0; i < urb->number_of_packets; ++i) {1486 if (urb->iso_frame_desc[i].status < 0) {1487 uvc_dbg(stream->dev, FRAME,1488 "USB isochronous frame lost (%d)\n",1489 urb->iso_frame_desc[i].status);1490 /* Mark the buffer as faulty. */1491 if (buf != NULL)1492 buf->error = 1;1493 continue;1494 }1495 1496 /* Decode the payload header. */1497 mem = urb->transfer_buffer + urb->iso_frame_desc[i].offset;1498 do {1499 ret = uvc_video_decode_start(stream, buf, mem,1500 urb->iso_frame_desc[i].actual_length);1501 if (ret == -EAGAIN)1502 uvc_video_next_buffers(stream, &buf, &meta_buf);1503 } while (ret == -EAGAIN);1504 1505 if (ret < 0)1506 continue;1507 1508 uvc_video_decode_meta(stream, meta_buf, mem, ret);1509 1510 /* Decode the payload data. */1511 uvc_video_decode_data(uvc_urb, buf, mem + ret,1512 urb->iso_frame_desc[i].actual_length - ret);1513 1514 /* Process the header again. */1515 uvc_video_decode_end(stream, buf, mem,1516 urb->iso_frame_desc[i].actual_length);1517 1518 if (buf->state == UVC_BUF_STATE_READY)1519 uvc_video_next_buffers(stream, &buf, &meta_buf);1520 }1521}1522 1523static void uvc_video_decode_bulk(struct uvc_urb *uvc_urb,1524 struct uvc_buffer *buf, struct uvc_buffer *meta_buf)1525{1526 struct urb *urb = uvc_urb->urb;1527 struct uvc_streaming *stream = uvc_urb->stream;1528 u8 *mem;1529 int len, ret;1530 1531 /*1532 * Ignore ZLPs if they're not part of a frame, otherwise process them1533 * to trigger the end of payload detection.1534 */1535 if (urb->actual_length == 0 && stream->bulk.header_size == 0)1536 return;1537 1538 mem = urb->transfer_buffer;1539 len = urb->actual_length;1540 stream->bulk.payload_size += len;1541 1542 /*1543 * If the URB is the first of its payload, decode and save the1544 * header.1545 */1546 if (stream->bulk.header_size == 0 && !stream->bulk.skip_payload) {1547 do {1548 ret = uvc_video_decode_start(stream, buf, mem, len);1549 if (ret == -EAGAIN)1550 uvc_video_next_buffers(stream, &buf, &meta_buf);1551 } while (ret == -EAGAIN);1552 1553 /* If an error occurred skip the rest of the payload. */1554 if (ret < 0 || buf == NULL) {1555 stream->bulk.skip_payload = 1;1556 } else {1557 memcpy(stream->bulk.header, mem, ret);1558 stream->bulk.header_size = ret;1559 1560 uvc_video_decode_meta(stream, meta_buf, mem, ret);1561 1562 mem += ret;1563 len -= ret;1564 }1565 }1566 1567 /*1568 * The buffer queue might have been cancelled while a bulk transfer1569 * was in progress, so we can reach here with buf equal to NULL. Make1570 * sure buf is never dereferenced if NULL.1571 */1572 1573 /* Prepare video data for processing. */1574 if (!stream->bulk.skip_payload && buf != NULL)1575 uvc_video_decode_data(uvc_urb, buf, mem, len);1576 1577 /*1578 * Detect the payload end by a URB smaller than the maximum size (or1579 * a payload size equal to the maximum) and process the header again.1580 */1581 if (urb->actual_length < urb->transfer_buffer_length ||1582 stream->bulk.payload_size >= stream->bulk.max_payload_size) {1583 if (!stream->bulk.skip_payload && buf != NULL) {1584 uvc_video_decode_end(stream, buf, stream->bulk.header,1585 stream->bulk.payload_size);1586 if (buf->state == UVC_BUF_STATE_READY)1587 uvc_video_next_buffers(stream, &buf, &meta_buf);1588 }1589 1590 stream->bulk.header_size = 0;1591 stream->bulk.skip_payload = 0;1592 stream->bulk.payload_size = 0;1593 }1594}1595 1596static void uvc_video_encode_bulk(struct uvc_urb *uvc_urb,1597 struct uvc_buffer *buf, struct uvc_buffer *meta_buf)1598{1599 struct urb *urb = uvc_urb->urb;1600 struct uvc_streaming *stream = uvc_urb->stream;1601 1602 u8 *mem = urb->transfer_buffer;1603 int len = stream->urb_size, ret;1604 1605 if (buf == NULL) {1606 urb->transfer_buffer_length = 0;1607 return;1608 }1609 1610 /* If the URB is the first of its payload, add the header. */1611 if (stream->bulk.header_size == 0) {1612 ret = uvc_video_encode_header(stream, buf, mem, len);1613 stream->bulk.header_size = ret;1614 stream->bulk.payload_size += ret;1615 mem += ret;1616 len -= ret;1617 }1618 1619 /* Process video data. */1620 ret = uvc_video_encode_data(stream, buf, mem, len);1621 1622 stream->bulk.payload_size += ret;1623 len -= ret;1624 1625 if (buf->bytesused == stream->queue.buf_used ||1626 stream->bulk.payload_size == stream->bulk.max_payload_size) {1627 if (buf->bytesused == stream->queue.buf_used) {1628 stream->queue.buf_used = 0;1629 buf->state = UVC_BUF_STATE_READY;1630 buf->buf.sequence = ++stream->sequence;1631 uvc_queue_next_buffer(&stream->queue, buf);1632 stream->last_fid ^= UVC_STREAM_FID;1633 }1634 1635 stream->bulk.header_size = 0;1636 stream->bulk.payload_size = 0;1637 }1638 1639 urb->transfer_buffer_length = stream->urb_size - len;1640}1641 1642static void uvc_video_complete(struct urb *urb)1643{1644 struct uvc_urb *uvc_urb = urb->context;1645 struct uvc_streaming *stream = uvc_urb->stream;1646 struct uvc_video_queue *queue = &stream->queue;1647 struct uvc_video_queue *qmeta = &stream->meta.queue;1648 struct vb2_queue *vb2_qmeta = stream->meta.vdev.queue;1649 struct uvc_buffer *buf = NULL;1650 struct uvc_buffer *buf_meta = NULL;1651 unsigned long flags;1652 int ret;1653 1654 switch (urb->status) {1655 case 0:1656 break;1657 1658 default:1659 dev_warn(&stream->intf->dev,1660 "Non-zero status (%d) in video completion handler.\n",1661 urb->status);1662 fallthrough;1663 case -ENOENT: /* usb_poison_urb() called. */1664 if (stream->frozen)1665 return;1666 fallthrough;1667 case -ECONNRESET: /* usb_unlink_urb() called. */1668 case -ESHUTDOWN: /* The endpoint is being disabled. */1669 uvc_queue_cancel(queue, urb->status == -ESHUTDOWN);1670 if (vb2_qmeta)1671 uvc_queue_cancel(qmeta, urb->status == -ESHUTDOWN);1672 return;1673 }1674 1675 buf = uvc_queue_get_current_buffer(queue);1676 1677 if (vb2_qmeta) {1678 spin_lock_irqsave(&qmeta->irqlock, flags);1679 if (!list_empty(&qmeta->irqqueue))1680 buf_meta = list_first_entry(&qmeta->irqqueue,1681 struct uvc_buffer, queue);1682 spin_unlock_irqrestore(&qmeta->irqlock, flags);1683 }1684 1685 /* Re-initialise the URB async work. */1686 uvc_urb->async_operations = 0;1687 1688 /* Sync DMA and invalidate vmap range. */1689 dma_sync_sgtable_for_cpu(uvc_stream_to_dmadev(uvc_urb->stream),1690 uvc_urb->sgt, uvc_stream_dir(stream));1691 invalidate_kernel_vmap_range(uvc_urb->buffer,1692 uvc_urb->stream->urb_size);1693 1694 /*1695 * Process the URB headers, and optionally queue expensive memcpy tasks1696 * to be deferred to a work queue.1697 */1698 stream->decode(uvc_urb, buf, buf_meta);1699 1700 /* If no async work is needed, resubmit the URB immediately. */1701 if (!uvc_urb->async_operations) {1702 ret = uvc_submit_urb(uvc_urb, GFP_ATOMIC);1703 if (ret < 0)1704 dev_err(&stream->intf->dev,1705 "Failed to resubmit video URB (%d).\n", ret);1706 return;1707 }1708 1709 queue_work(stream->async_wq, &uvc_urb->work);1710}1711 1712/*1713 * Free transfer buffers.1714 */1715static void uvc_free_urb_buffers(struct uvc_streaming *stream)1716{1717 struct device *dma_dev = uvc_stream_to_dmadev(stream);1718 struct uvc_urb *uvc_urb;1719 1720 for_each_uvc_urb(uvc_urb, stream) {1721 if (!uvc_urb->buffer)1722 continue;1723 1724 dma_vunmap_noncontiguous(dma_dev, uvc_urb->buffer);1725 dma_free_noncontiguous(dma_dev, stream->urb_size, uvc_urb->sgt,1726 uvc_stream_dir(stream));1727 1728 uvc_urb->buffer = NULL;1729 uvc_urb->sgt = NULL;1730 }1731 1732 stream->urb_size = 0;1733}1734 1735static bool uvc_alloc_urb_buffer(struct uvc_streaming *stream,1736 struct uvc_urb *uvc_urb, gfp_t gfp_flags)1737{1738 struct device *dma_dev = uvc_stream_to_dmadev(stream);1739 1740 uvc_urb->sgt = dma_alloc_noncontiguous(dma_dev, stream->urb_size,1741 uvc_stream_dir(stream),1742 gfp_flags, 0);1743 if (!uvc_urb->sgt)1744 return false;1745 uvc_urb->dma = uvc_urb->sgt->sgl->dma_address;1746 1747 uvc_urb->buffer = dma_vmap_noncontiguous(dma_dev, stream->urb_size,1748 uvc_urb->sgt);1749 if (!uvc_urb->buffer) {1750 dma_free_noncontiguous(dma_dev, stream->urb_size,1751 uvc_urb->sgt,1752 uvc_stream_dir(stream));1753 uvc_urb->sgt = NULL;1754 return false;1755 }1756 1757 return true;1758}1759 1760/*1761 * Allocate transfer buffers. This function can be called with buffers1762 * already allocated when resuming from suspend, in which case it will1763 * return without touching the buffers.1764 *1765 * Limit the buffer size to UVC_MAX_PACKETS bulk/isochronous packets. If the1766 * system is too low on memory try successively smaller numbers of packets1767 * until allocation succeeds.1768 *1769 * Return the number of allocated packets on success or 0 when out of memory.1770 */1771static int uvc_alloc_urb_buffers(struct uvc_streaming *stream,1772 unsigned int size, unsigned int psize, gfp_t gfp_flags)1773{1774 unsigned int npackets;1775 unsigned int i;1776 1777 /* Buffers are already allocated, bail out. */1778 if (stream->urb_size)1779 return stream->urb_size / psize;1780 1781 /*1782 * Compute the number of packets. Bulk endpoints might transfer UVC1783 * payloads across multiple URBs.1784 */1785 npackets = DIV_ROUND_UP(size, psize);1786 if (npackets > UVC_MAX_PACKETS)1787 npackets = UVC_MAX_PACKETS;1788 1789 /* Retry allocations until one succeed. */1790 for (; npackets > 1; npackets /= 2) {1791 stream->urb_size = psize * npackets;1792 1793 for (i = 0; i < UVC_URBS; ++i) {1794 struct uvc_urb *uvc_urb = &stream->uvc_urb[i];1795 1796 if (!uvc_alloc_urb_buffer(stream, uvc_urb, gfp_flags)) {1797 uvc_free_urb_buffers(stream);1798 break;1799 }1800 1801 uvc_urb->stream = stream;1802 }1803 1804 if (i == UVC_URBS) {1805 uvc_dbg(stream->dev, VIDEO,1806 "Allocated %u URB buffers of %ux%u bytes each\n",1807 UVC_URBS, npackets, psize);1808 return npackets;1809 }1810 }1811 1812 uvc_dbg(stream->dev, VIDEO,1813 "Failed to allocate URB buffers (%u bytes per packet)\n",1814 psize);1815 return 0;1816}1817 1818/*1819 * Uninitialize isochronous/bulk URBs and free transfer buffers.1820 */1821static void uvc_video_stop_transfer(struct uvc_streaming *stream,1822 int free_buffers)1823{1824 struct uvc_urb *uvc_urb;1825 1826 uvc_video_stats_stop(stream);1827 1828 /*1829 * We must poison the URBs rather than kill them to ensure that even1830 * after the completion handler returns, any asynchronous workqueues1831 * will be prevented from resubmitting the URBs.1832 */1833 for_each_uvc_urb(uvc_urb, stream)1834 usb_poison_urb(uvc_urb->urb);1835 1836 flush_workqueue(stream->async_wq);1837 1838 for_each_uvc_urb(uvc_urb, stream) {1839 usb_free_urb(uvc_urb->urb);1840 uvc_urb->urb = NULL;1841 }1842 1843 if (free_buffers)1844 uvc_free_urb_buffers(stream);1845}1846 1847/*1848 * Compute the maximum number of bytes per interval for an endpoint.1849 */1850u16 uvc_endpoint_max_bpi(struct usb_device *dev, struct usb_host_endpoint *ep)1851{1852 u16 psize;1853 1854 switch (dev->speed) {1855 case USB_SPEED_SUPER:1856 case USB_SPEED_SUPER_PLUS:1857 return le16_to_cpu(ep->ss_ep_comp.wBytesPerInterval);1858 default:1859 psize = usb_endpoint_maxp(&ep->desc);1860 psize *= usb_endpoint_maxp_mult(&ep->desc);1861 return psize;1862 }1863}1864 1865/*1866 * Initialize isochronous URBs and allocate transfer buffers. The packet size1867 * is given by the endpoint.1868 */1869static int uvc_init_video_isoc(struct uvc_streaming *stream,1870 struct usb_host_endpoint *ep, gfp_t gfp_flags)1871{1872 struct urb *urb;1873 struct uvc_urb *uvc_urb;1874 unsigned int npackets, i;1875 u16 psize;1876 u32 size;1877 1878 psize = uvc_endpoint_max_bpi(stream->dev->udev, ep);1879 size = stream->ctrl.dwMaxVideoFrameSize;1880 1881 npackets = uvc_alloc_urb_buffers(stream, size, psize, gfp_flags);1882 if (npackets == 0)1883 return -ENOMEM;1884 1885 size = npackets * psize;1886 1887 for_each_uvc_urb(uvc_urb, stream) {1888 urb = usb_alloc_urb(npackets, gfp_flags);1889 if (urb == NULL) {1890 uvc_video_stop_transfer(stream, 1);1891 return -ENOMEM;1892 }1893 1894 urb->dev = stream->dev->udev;1895 urb->context = uvc_urb;1896 urb->pipe = usb_rcvisocpipe(stream->dev->udev,1897 ep->desc.bEndpointAddress);1898 urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;1899 urb->transfer_dma = uvc_urb->dma;1900 urb->interval = ep->desc.bInterval;1901 urb->transfer_buffer = uvc_urb->buffer;1902 urb->complete = uvc_video_complete;1903 urb->number_of_packets = npackets;1904 urb->transfer_buffer_length = size;1905 1906 for (i = 0; i < npackets; ++i) {1907 urb->iso_frame_desc[i].offset = i * psize;1908 urb->iso_frame_desc[i].length = psize;1909 }1910 1911 uvc_urb->urb = urb;1912 }1913 1914 return 0;1915}1916 1917/*1918 * Initialize bulk URBs and allocate transfer buffers. The packet size is1919 * given by the endpoint.1920 */1921static int uvc_init_video_bulk(struct uvc_streaming *stream,1922 struct usb_host_endpoint *ep, gfp_t gfp_flags)1923{1924 struct urb *urb;1925 struct uvc_urb *uvc_urb;1926 unsigned int npackets, pipe;1927 u16 psize;1928 u32 size;1929 1930 psize = usb_endpoint_maxp(&ep->desc);1931 size = stream->ctrl.dwMaxPayloadTransferSize;1932 stream->bulk.max_payload_size = size;1933 1934 npackets = uvc_alloc_urb_buffers(stream, size, psize, gfp_flags);1935 if (npackets == 0)1936 return -ENOMEM;1937 1938 size = npackets * psize;1939 1940 if (usb_endpoint_dir_in(&ep->desc))1941 pipe = usb_rcvbulkpipe(stream->dev->udev,1942 ep->desc.bEndpointAddress);1943 else1944 pipe = usb_sndbulkpipe(stream->dev->udev,1945 ep->desc.bEndpointAddress);1946 1947 if (stream->type == V4L2_BUF_TYPE_VIDEO_OUTPUT)1948 size = 0;1949 1950 for_each_uvc_urb(uvc_urb, stream) {1951 urb = usb_alloc_urb(0, gfp_flags);1952 if (urb == NULL) {1953 uvc_video_stop_transfer(stream, 1);1954 return -ENOMEM;1955 }1956 1957 usb_fill_bulk_urb(urb, stream->dev->udev, pipe, uvc_urb->buffer,1958 size, uvc_video_complete, uvc_urb);1959 urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;1960 urb->transfer_dma = uvc_urb->dma;1961 1962 uvc_urb->urb = urb;1963 }1964 1965 return 0;1966}1967 1968/*1969 * Initialize isochronous/bulk URBs and allocate transfer buffers.1970 */1971static int uvc_video_start_transfer(struct uvc_streaming *stream,1972 gfp_t gfp_flags)1973{1974 struct usb_interface *intf = stream->intf;1975 struct usb_host_endpoint *ep;1976 struct uvc_urb *uvc_urb;1977 unsigned int i;1978 int ret;1979 1980 stream->sequence = -1;1981 stream->last_fid = -1;1982 stream->bulk.header_size = 0;1983 stream->bulk.skip_payload = 0;1984 stream->bulk.payload_size = 0;1985 1986 uvc_video_stats_start(stream);1987 1988 if (intf->num_altsetting > 1) {1989 struct usb_host_endpoint *best_ep = NULL;1990 unsigned int best_psize = UINT_MAX;1991 unsigned int bandwidth;1992 unsigned int altsetting;1993 int intfnum = stream->intfnum;1994 1995 /* Isochronous endpoint, select the alternate setting. */1996 bandwidth = stream->ctrl.dwMaxPayloadTransferSize;1997 1998 if (bandwidth == 0) {1999 uvc_dbg(stream->dev, VIDEO,2000 "Device requested null bandwidth, defaulting to lowest\n");2001 bandwidth = 1;2002 } else {2003 uvc_dbg(stream->dev, VIDEO,2004 "Device requested %u B/frame bandwidth\n",2005 bandwidth);2006 }2007 2008 for (i = 0; i < intf->num_altsetting; ++i) {2009 struct usb_host_interface *alts;2010 unsigned int psize;2011 2012 alts = &intf->altsetting[i];2013 ep = uvc_find_endpoint(alts,2014 stream->header.bEndpointAddress);2015 if (ep == NULL)2016 continue;2017 2018 /* Check if the bandwidth is high enough. */2019 psize = uvc_endpoint_max_bpi(stream->dev->udev, ep);2020 if (psize >= bandwidth && psize < best_psize) {2021 altsetting = alts->desc.bAlternateSetting;2022 best_psize = psize;2023 best_ep = ep;2024 }2025 }2026 2027 if (best_ep == NULL) {2028 uvc_dbg(stream->dev, VIDEO,2029 "No fast enough alt setting for requested bandwidth\n");2030 return -EIO;2031 }2032 2033 uvc_dbg(stream->dev, VIDEO,2034 "Selecting alternate setting %u (%u B/frame bandwidth)\n",2035 altsetting, best_psize);2036 2037 /*2038 * Some devices, namely the Logitech C910 and B910, are unable2039 * to recover from a USB autosuspend, unless the alternate2040 * setting of the streaming interface is toggled.2041 */2042 if (stream->dev->quirks & UVC_QUIRK_WAKE_AUTOSUSPEND) {2043 usb_set_interface(stream->dev->udev, intfnum,2044 altsetting);2045 usb_set_interface(stream->dev->udev, intfnum, 0);2046 }2047 2048 ret = usb_set_interface(stream->dev->udev, intfnum, altsetting);2049 if (ret < 0)2050 return ret;2051 2052 ret = uvc_init_video_isoc(stream, best_ep, gfp_flags);2053 } else {2054 /* Bulk endpoint, proceed to URB initialization. */2055 ep = uvc_find_endpoint(&intf->altsetting[0],2056 stream->header.bEndpointAddress);2057 if (ep == NULL)2058 return -EIO;2059 2060 /* Reject broken descriptors. */2061 if (usb_endpoint_maxp(&ep->desc) == 0)2062 return -EIO;2063 2064 ret = uvc_init_video_bulk(stream, ep, gfp_flags);2065 }2066 2067 if (ret < 0)2068 return ret;2069 2070 /* Submit the URBs. */2071 for_each_uvc_urb(uvc_urb, stream) {2072 ret = uvc_submit_urb(uvc_urb, gfp_flags);2073 if (ret < 0) {2074 dev_err(&stream->intf->dev,2075 "Failed to submit URB %u (%d).\n",2076 uvc_urb_index(uvc_urb), ret);2077 uvc_video_stop_transfer(stream, 1);2078 return ret;2079 }2080 }2081 2082 /*2083 * The Logitech C920 temporarily forgets that it should not be adjusting2084 * Exposure Absolute during init so restore controls to stored values.2085 */2086 if (stream->dev->quirks & UVC_QUIRK_RESTORE_CTRLS_ON_INIT)2087 uvc_ctrl_restore_values(stream->dev);2088 2089 return 0;2090}2091 2092/* --------------------------------------------------------------------------2093 * Suspend/resume2094 */2095 2096/*2097 * Stop streaming without disabling the video queue.2098 *2099 * To let userspace applications resume without trouble, we must not touch the2100 * video buffers in any way. We mark the device as frozen to make sure the URB2101 * completion handler won't try to cancel the queue when we kill the URBs.2102 */2103int uvc_video_suspend(struct uvc_streaming *stream)2104{2105 if (!uvc_queue_streaming(&stream->queue))2106 return 0;2107 2108 stream->frozen = 1;2109 uvc_video_stop_transfer(stream, 0);2110 usb_set_interface(stream->dev->udev, stream->intfnum, 0);2111 return 0;2112}2113 2114/*2115 * Reconfigure the video interface and restart streaming if it was enabled2116 * before suspend.2117 *2118 * If an error occurs, disable the video queue. This will wake all pending2119 * buffers, making sure userspace applications are notified of the problem2120 * instead of waiting forever.2121 */2122int uvc_video_resume(struct uvc_streaming *stream, int reset)2123{2124 int ret;2125 2126 /*2127 * If the bus has been reset on resume, set the alternate setting to 0.2128 * This should be the default value, but some devices crash or otherwise2129 * misbehave if they don't receive a SET_INTERFACE request before any2130 * other video control request.2131 */2132 if (reset)2133 usb_set_interface(stream->dev->udev, stream->intfnum, 0);2134 2135 stream->frozen = 0;2136 2137 uvc_video_clock_reset(&stream->clock);2138 2139 if (!uvc_queue_streaming(&stream->queue))2140 return 0;2141 2142 ret = uvc_commit_video(stream, &stream->ctrl);2143 if (ret < 0)2144 return ret;2145 2146 return uvc_video_start_transfer(stream, GFP_NOIO);2147}2148 2149/* ------------------------------------------------------------------------2150 * Video device2151 */2152 2153/*2154 * Initialize the UVC video device by switching to alternate setting 0 and2155 * retrieve the default format.2156 *2157 * Some cameras (namely the Fuji Finepix) set the format and frame2158 * indexes to zero. The UVC standard doesn't clearly make this a spec2159 * violation, so try to silently fix the values if possible.2160 *2161 * This function is called before registering the device with V4L.2162 */2163int uvc_video_init(struct uvc_streaming *stream)2164{2165 struct uvc_streaming_control *probe = &stream->ctrl;2166 const struct uvc_format *format = NULL;2167 const struct uvc_frame *frame = NULL;2168 struct uvc_urb *uvc_urb;2169 unsigned int i;2170 int ret;2171 2172 if (stream->nformats == 0) {2173 dev_info(&stream->intf->dev,2174 "No supported video formats found.\n");2175 return -EINVAL;2176 }2177 2178 atomic_set(&stream->active, 0);2179 2180 /*2181 * Alternate setting 0 should be the default, yet the XBox Live Vision2182 * Cam (and possibly other devices) crash or otherwise misbehave if2183 * they don't receive a SET_INTERFACE request before any other video2184 * control request.2185 */2186 usb_set_interface(stream->dev->udev, stream->intfnum, 0);2187 2188 /*2189 * Set the streaming probe control with default streaming parameters2190 * retrieved from the device. Webcams that don't support GET_DEF2191 * requests on the probe control will just keep their current streaming2192 * parameters.2193 */2194 if (uvc_get_video_ctrl(stream, probe, 1, UVC_GET_DEF) == 0)2195 uvc_set_video_ctrl(stream, probe, 1);2196 2197 /*2198 * Initialize the streaming parameters with the probe control current2199 * value. This makes sure SET_CUR requests on the streaming commit2200 * control will always use values retrieved from a successful GET_CUR2201 * request on the probe control, as required by the UVC specification.2202 */2203 ret = uvc_get_video_ctrl(stream, probe, 1, UVC_GET_CUR);2204 2205 /*2206 * Elgato Cam Link 4k can be in a stalled state if the resolution of2207 * the external source has changed while the firmware initializes.2208 * Once in this state, the device is useless until it receives a2209 * USB reset. It has even been observed that the stalled state will2210 * continue even after unplugging the device.2211 */2212 if (ret == -EPROTO &&2213 usb_match_one_id(stream->dev->intf, &elgato_cam_link_4k)) {2214 dev_err(&stream->intf->dev, "Elgato Cam Link 4K firmware crash detected\n");2215 dev_err(&stream->intf->dev, "Resetting the device, unplug and replug to recover\n");2216 usb_reset_device(stream->dev->udev);2217 }2218 2219 if (ret < 0)2220 return ret;2221 2222 /*2223 * Check if the default format descriptor exists. Use the first2224 * available format otherwise.2225 */2226 for (i = stream->nformats; i > 0; --i) {2227 format = &stream->formats[i-1];2228 if (format->index == probe->bFormatIndex)2229 break;2230 }2231 2232 if (format->nframes == 0) {2233 dev_info(&stream->intf->dev,2234 "No frame descriptor found for the default format.\n");2235 return -EINVAL;2236 }2237 2238 /*2239 * Zero bFrameIndex might be correct. Stream-based formats (including2240 * MPEG-2 TS and DV) do not support frames but have a dummy frame2241 * descriptor with bFrameIndex set to zero. If the default frame2242 * descriptor is not found, use the first available frame.2243 */2244 for (i = format->nframes; i > 0; --i) {2245 frame = &format->frames[i-1];2246 if (frame->bFrameIndex == probe->bFrameIndex)2247 break;2248 }2249 2250 probe->bFormatIndex = format->index;2251 probe->bFrameIndex = frame->bFrameIndex;2252 2253 stream->def_format = format;2254 stream->cur_format = format;2255 stream->cur_frame = frame;2256 2257 /* Select the video decoding function */2258 if (stream->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {2259 if (stream->dev->quirks & UVC_QUIRK_BUILTIN_ISIGHT)2260 stream->decode = uvc_video_decode_isight;2261 else if (stream->intf->num_altsetting > 1)2262 stream->decode = uvc_video_decode_isoc;2263 else2264 stream->decode = uvc_video_decode_bulk;2265 } else {2266 if (stream->intf->num_altsetting == 1)2267 stream->decode = uvc_video_encode_bulk;2268 else {2269 dev_info(&stream->intf->dev,2270 "Isochronous endpoints are not supported for video output devices.\n");2271 return -EINVAL;2272 }2273 }2274 2275 /* Prepare asynchronous work items. */2276 for_each_uvc_urb(uvc_urb, stream)2277 INIT_WORK(&uvc_urb->work, uvc_video_copy_data_work);2278 2279 return 0;2280}2281 2282int uvc_video_start_streaming(struct uvc_streaming *stream)2283{2284 int ret;2285 2286 ret = uvc_video_clock_init(&stream->clock);2287 if (ret < 0)2288 return ret;2289 2290 /* Commit the streaming parameters. */2291 ret = uvc_commit_video(stream, &stream->ctrl);2292 if (ret < 0)2293 goto error_commit;2294 2295 ret = uvc_video_start_transfer(stream, GFP_KERNEL);2296 if (ret < 0)2297 goto error_video;2298 2299 return 0;2300 2301error_video:2302 usb_set_interface(stream->dev->udev, stream->intfnum, 0);2303error_commit:2304 uvc_video_clock_cleanup(&stream->clock);2305 2306 return ret;2307}2308 2309void uvc_video_stop_streaming(struct uvc_streaming *stream)2310{2311 uvc_video_stop_transfer(stream, 1);2312 2313 if (stream->intf->num_altsetting > 1) {2314 usb_set_interface(stream->dev->udev, stream->intfnum, 0);2315 } else {2316 /*2317 * UVC doesn't specify how to inform a bulk-based device2318 * when the video stream is stopped. Windows sends a2319 * CLEAR_FEATURE(HALT) request to the video streaming2320 * bulk endpoint, mimic the same behaviour.2321 */2322 unsigned int epnum = stream->header.bEndpointAddress2323 & USB_ENDPOINT_NUMBER_MASK;2324 unsigned int dir = stream->header.bEndpointAddress2325 & USB_ENDPOINT_DIR_MASK;2326 unsigned int pipe;2327 2328 pipe = usb_sndbulkpipe(stream->dev->udev, epnum) | dir;2329 usb_clear_halt(stream->dev->udev, pipe);2330 }2331 2332 uvc_video_clock_cleanup(&stream->clock);2333}2334