diff options
Diffstat (limited to 'drivers/media/usb/uvc/uvc_video.c')
| -rw-r--r-- | drivers/media/usb/uvc/uvc_video.c | 2179 |
1 files changed, 2179 insertions, 0 deletions
diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c new file mode 100644 index 000000000..03dfe96bc --- /dev/null +++ b/drivers/media/usb/uvc/uvc_video.c @@ -0,0 +1,2179 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * uvc_video.c -- USB Video Class driver - Video handling + * + * Copyright (C) 2005-2010 + * Laurent Pinchart (laurent.pinchart@ideasonboard.com) + */ + +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/usb.h> +#include <linux/videodev2.h> +#include <linux/vmalloc.h> +#include <linux/wait.h> +#include <linux/atomic.h> +#include <asm/unaligned.h> + +#include <media/v4l2-common.h> + +#include "uvcvideo.h" + +/* ------------------------------------------------------------------------ + * UVC Controls + */ + +static int __uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit, + u8 intfnum, u8 cs, void *data, u16 size, + int timeout) +{ + u8 type = USB_TYPE_CLASS | USB_RECIP_INTERFACE; + unsigned int pipe; + + pipe = (query & 0x80) ? usb_rcvctrlpipe(dev->udev, 0) + : usb_sndctrlpipe(dev->udev, 0); + type |= (query & 0x80) ? USB_DIR_IN : USB_DIR_OUT; + + return usb_control_msg(dev->udev, pipe, query, type, cs << 8, + unit << 8 | intfnum, data, size, timeout); +} + +static const char *uvc_query_name(u8 query) +{ + switch (query) { + case UVC_SET_CUR: + return "SET_CUR"; + case UVC_GET_CUR: + return "GET_CUR"; + case UVC_GET_MIN: + return "GET_MIN"; + case UVC_GET_MAX: + return "GET_MAX"; + case UVC_GET_RES: + return "GET_RES"; + case UVC_GET_LEN: + return "GET_LEN"; + case UVC_GET_INFO: + return "GET_INFO"; + case UVC_GET_DEF: + return "GET_DEF"; + default: + return "<invalid>"; + } +} + +int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit, + u8 intfnum, u8 cs, void *data, u16 size) +{ + int ret; + u8 error; + u8 tmp; + + ret = __uvc_query_ctrl(dev, query, unit, intfnum, cs, data, size, + UVC_CTRL_CONTROL_TIMEOUT); + if (likely(ret == size)) + return 0; + + uvc_printk(KERN_ERR, + "Failed to query (%s) UVC control %u on unit %u: %d (exp. %u).\n", + uvc_query_name(query), cs, unit, ret, size); + + if (ret != -EPIPE) + return ret; + + tmp = *(u8 *)data; + + ret = __uvc_query_ctrl(dev, UVC_GET_CUR, 0, intfnum, + UVC_VC_REQUEST_ERROR_CODE_CONTROL, data, 1, + UVC_CTRL_CONTROL_TIMEOUT); + + error = *(u8 *)data; + *(u8 *)data = tmp; + + if (ret != 1) + return ret < 0 ? ret : -EPIPE; + + uvc_trace(UVC_TRACE_CONTROL, "Control error %u\n", error); + + switch (error) { + case 0: + /* Cannot happen - we received a STALL */ + return -EPIPE; + case 1: /* Not ready */ + return -EBUSY; + case 2: /* Wrong state */ + return -EILSEQ; + case 3: /* Power */ + return -EREMOTE; + case 4: /* Out of range */ + return -ERANGE; + case 5: /* Invalid unit */ + case 6: /* Invalid control */ + case 7: /* Invalid Request */ + /* + * The firmware has not properly implemented + * the control or there has been a HW error. + */ + return -EIO; + case 8: /* Invalid value within range */ + return -EINVAL; + default: /* reserved or unknown */ + break; + } + + return -EPIPE; +} + +static void uvc_fixup_video_ctrl(struct uvc_streaming *stream, + struct uvc_streaming_control *ctrl) +{ + static const struct usb_device_id elgato_cam_link_4k = { + USB_DEVICE(0x0fd9, 0x0066) + }; + struct uvc_format *format = NULL; + struct uvc_frame *frame = NULL; + unsigned int i; + + /* + * The response of the Elgato Cam Link 4K is incorrect: The second byte + * contains bFormatIndex (instead of being the second byte of bmHint). + * The first byte is always zero. The third byte is always 1. + * + * The UVC 1.5 class specification defines the first five bits in the + * bmHint bitfield. The remaining bits are reserved and should be zero. + * Therefore a valid bmHint will be less than 32. + * + * Latest Elgato Cam Link 4K firmware as of 2021-03-23 needs this fix. + * MCU: 20.02.19, FPGA: 67 + */ + if (usb_match_one_id(stream->dev->intf, &elgato_cam_link_4k) && + ctrl->bmHint > 255) { + u8 corrected_format_index = ctrl->bmHint >> 8; + + /* uvc_dbg(stream->dev, VIDEO, + "Correct USB video probe response from {bmHint: 0x%04x, bFormatIndex: %u} to {bmHint: 0x%04x, bFormatIndex: %u}\n", + ctrl->bmHint, ctrl->bFormatIndex, + 1, corrected_format_index); */ + ctrl->bmHint = 1; + ctrl->bFormatIndex = corrected_format_index; + } + + for (i = 0; i < stream->nformats; ++i) { + if (stream->format[i].index == ctrl->bFormatIndex) { + format = &stream->format[i]; + break; + } + } + + if (format == NULL) + return; + + for (i = 0; i < format->nframes; ++i) { + if (format->frame[i].bFrameIndex == ctrl->bFrameIndex) { + frame = &format->frame[i]; + break; + } + } + + if (frame == NULL) + return; + + if (!(format->flags & UVC_FMT_FLAG_COMPRESSED) || + (ctrl->dwMaxVideoFrameSize == 0 && + stream->dev->uvc_version < 0x0110)) + ctrl->dwMaxVideoFrameSize = + frame->dwMaxVideoFrameBufferSize; + + /* The "TOSHIBA Web Camera - 5M" Chicony device (04f2:b50b) seems to + * compute the bandwidth on 16 bits and erroneously sign-extend it to + * 32 bits, resulting in a huge bandwidth value. Detect and fix that + * condition by setting the 16 MSBs to 0 when they're all equal to 1. + */ + if ((ctrl->dwMaxPayloadTransferSize & 0xffff0000) == 0xffff0000) + ctrl->dwMaxPayloadTransferSize &= ~0xffff0000; + + if (!(format->flags & UVC_FMT_FLAG_COMPRESSED) && + stream->dev->quirks & UVC_QUIRK_FIX_BANDWIDTH && + stream->intf->num_altsetting > 1) { + u32 interval; + u32 bandwidth; + + interval = (ctrl->dwFrameInterval > 100000) + ? ctrl->dwFrameInterval + : frame->dwFrameInterval[0]; + + /* Compute a bandwidth estimation by multiplying the frame + * size by the number of video frames per second, divide the + * result by the number of USB frames (or micro-frames for + * high-speed devices) per second and add the UVC header size + * (assumed to be 12 bytes long). + */ + bandwidth = frame->wWidth * frame->wHeight / 8 * format->bpp; + bandwidth *= 10000000 / interval + 1; + bandwidth /= 1000; + if (stream->dev->udev->speed == USB_SPEED_HIGH) + bandwidth /= 8; + bandwidth += 12; + + /* The bandwidth estimate is too low for many cameras. Don't use + * maximum packet sizes lower than 1024 bytes to try and work + * around the problem. According to measurements done on two + * different camera models, the value is high enough to get most + * resolutions working while not preventing two simultaneous + * VGA streams at 15 fps. + */ + bandwidth = max_t(u32, bandwidth, 1024); + + ctrl->dwMaxPayloadTransferSize = bandwidth; + } +} + +static size_t uvc_video_ctrl_size(struct uvc_streaming *stream) +{ + /* + * Return the size of the video probe and commit controls, which depends + * on the protocol version. + */ + if (stream->dev->uvc_version < 0x0110) + return 26; + else if (stream->dev->uvc_version < 0x0150) + return 34; + else + return 48; +} + +static int uvc_get_video_ctrl(struct uvc_streaming *stream, + struct uvc_streaming_control *ctrl, int probe, u8 query) +{ + u16 size = uvc_video_ctrl_size(stream); + u8 *data; + int ret; + + if ((stream->dev->quirks & UVC_QUIRK_PROBE_DEF) && + query == UVC_GET_DEF) + return -EIO; + + data = kmalloc(size, GFP_KERNEL); + if (data == NULL) + return -ENOMEM; + + ret = __uvc_query_ctrl(stream->dev, query, 0, stream->intfnum, + probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data, + size, uvc_timeout_param); + + if ((query == UVC_GET_MIN || query == UVC_GET_MAX) && ret == 2) { + /* Some cameras, mostly based on Bison Electronics chipsets, + * answer a GET_MIN or GET_MAX request with the wCompQuality + * field only. + */ + uvc_warn_once(stream->dev, UVC_WARN_MINMAX, "UVC non " + "compliance - GET_MIN/MAX(PROBE) incorrectly " + "supported. Enabling workaround.\n"); + memset(ctrl, 0, sizeof(*ctrl)); + ctrl->wCompQuality = le16_to_cpup((__le16 *)data); + ret = 0; + goto out; + } else if (query == UVC_GET_DEF && probe == 1 && ret != size) { + /* Many cameras don't support the GET_DEF request on their + * video probe control. Warn once and return, the caller will + * fall back to GET_CUR. + */ + uvc_warn_once(stream->dev, UVC_WARN_PROBE_DEF, "UVC non " + "compliance - GET_DEF(PROBE) not supported. " + "Enabling workaround.\n"); + ret = -EIO; + goto out; + } else if (ret != size) { + uvc_printk(KERN_ERR, "Failed to query (%u) UVC %s control : " + "%d (exp. %u).\n", query, probe ? "probe" : "commit", + ret, size); + ret = -EIO; + goto out; + } + + ctrl->bmHint = le16_to_cpup((__le16 *)&data[0]); + ctrl->bFormatIndex = data[2]; + ctrl->bFrameIndex = data[3]; + ctrl->dwFrameInterval = le32_to_cpup((__le32 *)&data[4]); + ctrl->wKeyFrameRate = le16_to_cpup((__le16 *)&data[8]); + ctrl->wPFrameRate = le16_to_cpup((__le16 *)&data[10]); + ctrl->wCompQuality = le16_to_cpup((__le16 *)&data[12]); + ctrl->wCompWindowSize = le16_to_cpup((__le16 *)&data[14]); + ctrl->wDelay = le16_to_cpup((__le16 *)&data[16]); + ctrl->dwMaxVideoFrameSize = get_unaligned_le32(&data[18]); + ctrl->dwMaxPayloadTransferSize = get_unaligned_le32(&data[22]); + + if (size >= 34) { + ctrl->dwClockFrequency = get_unaligned_le32(&data[26]); + ctrl->bmFramingInfo = data[30]; + ctrl->bPreferedVersion = data[31]; + ctrl->bMinVersion = data[32]; + ctrl->bMaxVersion = data[33]; + } else { + ctrl->dwClockFrequency = stream->dev->clock_frequency; + ctrl->bmFramingInfo = 0; + ctrl->bPreferedVersion = 0; + ctrl->bMinVersion = 0; + ctrl->bMaxVersion = 0; + } + + /* Some broken devices return null or wrong dwMaxVideoFrameSize and + * dwMaxPayloadTransferSize fields. Try to get the value from the + * format and frame descriptors. + */ + uvc_fixup_video_ctrl(stream, ctrl); + ret = 0; + +out: + kfree(data); + return ret; +} + +static int uvc_set_video_ctrl(struct uvc_streaming *stream, + struct uvc_streaming_control *ctrl, int probe) +{ + u16 size = uvc_video_ctrl_size(stream); + u8 *data; + int ret; + + data = kzalloc(size, GFP_KERNEL); + if (data == NULL) + return -ENOMEM; + + *(__le16 *)&data[0] = cpu_to_le16(ctrl->bmHint); + data[2] = ctrl->bFormatIndex; + data[3] = ctrl->bFrameIndex; + *(__le32 *)&data[4] = cpu_to_le32(ctrl->dwFrameInterval); + *(__le16 *)&data[8] = cpu_to_le16(ctrl->wKeyFrameRate); + *(__le16 *)&data[10] = cpu_to_le16(ctrl->wPFrameRate); + *(__le16 *)&data[12] = cpu_to_le16(ctrl->wCompQuality); + *(__le16 *)&data[14] = cpu_to_le16(ctrl->wCompWindowSize); + *(__le16 *)&data[16] = cpu_to_le16(ctrl->wDelay); + put_unaligned_le32(ctrl->dwMaxVideoFrameSize, &data[18]); + put_unaligned_le32(ctrl->dwMaxPayloadTransferSize, &data[22]); + + if (size >= 34) { + put_unaligned_le32(ctrl->dwClockFrequency, &data[26]); + data[30] = ctrl->bmFramingInfo; + data[31] = ctrl->bPreferedVersion; + data[32] = ctrl->bMinVersion; + data[33] = ctrl->bMaxVersion; + } + + ret = __uvc_query_ctrl(stream->dev, UVC_SET_CUR, 0, stream->intfnum, + probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data, + size, uvc_timeout_param); + if (ret != size) { + uvc_printk(KERN_ERR, "Failed to set UVC %s control : " + "%d (exp. %u).\n", probe ? "probe" : "commit", + ret, size); + ret = -EIO; + } + + kfree(data); + return ret; +} + +int uvc_probe_video(struct uvc_streaming *stream, + struct uvc_streaming_control *probe) +{ + struct uvc_streaming_control probe_min, probe_max; + u16 bandwidth; + unsigned int i; + int ret; + + /* Perform probing. The device should adjust the requested values + * according to its capabilities. However, some devices, namely the + * first generation UVC Logitech webcams, don't implement the Video + * Probe control properly, and just return the needed bandwidth. For + * that reason, if the needed bandwidth exceeds the maximum available + * bandwidth, try to lower the quality. + */ + ret = uvc_set_video_ctrl(stream, probe, 1); + if (ret < 0) + goto done; + + /* Get the minimum and maximum values for compression settings. */ + if (!(stream->dev->quirks & UVC_QUIRK_PROBE_MINMAX)) { + ret = uvc_get_video_ctrl(stream, &probe_min, 1, UVC_GET_MIN); + if (ret < 0) + goto done; + ret = uvc_get_video_ctrl(stream, &probe_max, 1, UVC_GET_MAX); + if (ret < 0) + goto done; + + probe->wCompQuality = probe_max.wCompQuality; + } + + for (i = 0; i < 2; ++i) { + ret = uvc_set_video_ctrl(stream, probe, 1); + if (ret < 0) + goto done; + ret = uvc_get_video_ctrl(stream, probe, 1, UVC_GET_CUR); + if (ret < 0) + goto done; + + if (stream->intf->num_altsetting == 1) + break; + + bandwidth = probe->dwMaxPayloadTransferSize; + if (bandwidth <= stream->maxpsize) + break; + + if (stream->dev->quirks & UVC_QUIRK_PROBE_MINMAX) { + ret = -ENOSPC; + goto done; + } + + /* TODO: negotiate compression parameters */ + probe->wKeyFrameRate = probe_min.wKeyFrameRate; + probe->wPFrameRate = probe_min.wPFrameRate; + probe->wCompQuality = probe_max.wCompQuality; + probe->wCompWindowSize = probe_min.wCompWindowSize; + } + +done: + return ret; +} + +static int uvc_commit_video(struct uvc_streaming *stream, + struct uvc_streaming_control *probe) +{ + return uvc_set_video_ctrl(stream, probe, 0); +} + +/* ----------------------------------------------------------------------------- + * Clocks and timestamps + */ + +static inline ktime_t uvc_video_get_time(void) +{ + if (uvc_clock_param == CLOCK_MONOTONIC) + return ktime_get(); + else + return ktime_get_real(); +} + +static void +uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf, + const u8 *data, int len) +{ + struct uvc_clock_sample *sample; + unsigned int header_size; + bool has_pts = false; + bool has_scr = false; + unsigned long flags; + ktime_t time; + u16 host_sof; + u16 dev_sof; + + switch (data[1] & (UVC_STREAM_PTS | UVC_STREAM_SCR)) { + case UVC_STREAM_PTS | UVC_STREAM_SCR: + header_size = 12; + has_pts = true; + has_scr = true; + break; + case UVC_STREAM_PTS: + header_size = 6; + has_pts = true; + break; + case UVC_STREAM_SCR: + header_size = 8; + has_scr = true; + break; + default: + header_size = 2; + break; + } + + /* Check for invalid headers. */ + if (len < header_size) + return; + + /* Extract the timestamps: + * + * - store the frame PTS in the buffer structure + * - if the SCR field is present, retrieve the host SOF counter and + * kernel timestamps and store them with the SCR STC and SOF fields + * in the ring buffer + */ + if (has_pts && buf != NULL) + buf->pts = get_unaligned_le32(&data[2]); + + if (!has_scr) + return; + + /* To limit the amount of data, drop SCRs with an SOF identical to the + * previous one. + */ + dev_sof = get_unaligned_le16(&data[header_size - 2]); + if (dev_sof == stream->clock.last_sof) + return; + + stream->clock.last_sof = dev_sof; + + host_sof = usb_get_current_frame_number(stream->dev->udev); + time = uvc_video_get_time(); + + /* The UVC specification allows device implementations that can't obtain + * the USB frame number to keep their own frame counters as long as they + * match the size and frequency of the frame number associated with USB + * SOF tokens. The SOF values sent by such devices differ from the USB + * SOF tokens by a fixed offset that needs to be estimated and accounted + * for to make timestamp recovery as accurate as possible. + * + * The offset is estimated the first time a device SOF value is received + * as the difference between the host and device SOF values. As the two + * SOF values can differ slightly due to transmission delays, consider + * that the offset is null if the difference is not higher than 10 ms + * (negative differences can not happen and are thus considered as an + * offset). The video commit control wDelay field should be used to + * compute a dynamic threshold instead of using a fixed 10 ms value, but + * devices don't report reliable wDelay values. + * + * See uvc_video_clock_host_sof() for an explanation regarding why only + * the 8 LSBs of the delta are kept. + */ + if (stream->clock.sof_offset == (u16)-1) { + u16 delta_sof = (host_sof - dev_sof) & 255; + if (delta_sof >= 10) + stream->clock.sof_offset = delta_sof; + else + stream->clock.sof_offset = 0; + } + + dev_sof = (dev_sof + stream->clock.sof_offset) & 2047; + + spin_lock_irqsave(&stream->clock.lock, flags); + + sample = &stream->clock.samples[stream->clock.head]; + sample->dev_stc = get_unaligned_le32(&data[header_size - 6]); + sample->dev_sof = dev_sof; + sample->host_sof = host_sof; + sample->host_time = time; + + /* Update the sliding window head and count. */ + stream->clock.head = (stream->clock.head + 1) % stream->clock.size; + + if (stream->clock.count < stream->clock.size) + stream->clock.count++; + + spin_unlock_irqrestore(&stream->clock.lock, flags); +} + +static void uvc_video_clock_reset(struct uvc_streaming *stream) +{ + struct uvc_clock *clock = &stream->clock; + + clock->head = 0; + clock->count = 0; + clock->last_sof = -1; + clock->sof_offset = -1; +} + +static int uvc_video_clock_init(struct uvc_streaming *stream) +{ + struct uvc_clock *clock = &stream->clock; + + spin_lock_init(&clock->lock); + clock->size = 32; + + clock->samples = kmalloc_array(clock->size, sizeof(*clock->samples), + GFP_KERNEL); + if (clock->samples == NULL) + return -ENOMEM; + + uvc_video_clock_reset(stream); + + return 0; +} + +static void uvc_video_clock_cleanup(struct uvc_streaming *stream) +{ + kfree(stream->clock.samples); + stream->clock.samples = NULL; +} + +/* + * uvc_video_clock_host_sof - Return the host SOF value for a clock sample + * + * Host SOF counters reported by usb_get_current_frame_number() usually don't + * cover the whole 11-bits SOF range (0-2047) but are limited to the HCI frame + * schedule window. They can be limited to 8, 9 or 10 bits depending on the host + * controller and its configuration. + * + * We thus need to recover the SOF value corresponding to the host frame number. + * As the device and host frame numbers are sampled in a short interval, the + * difference between their values should be equal to a small delta plus an + * integer multiple of 256 caused by the host frame number limited precision. + * + * To obtain the recovered host SOF value, compute the small delta by masking + * the high bits of the host frame counter and device SOF difference and add it + * to the device SOF value. + */ +static u16 uvc_video_clock_host_sof(const struct uvc_clock_sample *sample) +{ + /* The delta value can be negative. */ + s8 delta_sof; + + delta_sof = (sample->host_sof - sample->dev_sof) & 255; + + return (sample->dev_sof + delta_sof) & 2047; +} + +/* + * uvc_video_clock_update - Update the buffer timestamp + * + * This function converts the buffer PTS timestamp to the host clock domain by + * going through the USB SOF clock domain and stores the result in the V4L2 + * buffer timestamp field. + * + * The relationship between the device clock and the host clock isn't known. + * However, the device and the host share the common USB SOF clock which can be + * used to recover that relationship. + * + * The relationship between the device clock and the USB SOF clock is considered + * to be linear over the clock samples sliding window and is given by + * + * SOF = m * PTS + p + * + * Several methods to compute the slope (m) and intercept (p) can be used. As + * the clock drift should be small compared to the sliding window size, we + * assume that the line that goes through the points at both ends of the window + * is a good approximation. Naming those points P1 and P2, we get + * + * SOF = (SOF2 - SOF1) / (STC2 - STC1) * PTS + * + (SOF1 * STC2 - SOF2 * STC1) / (STC2 - STC1) + * + * or + * + * SOF = ((SOF2 - SOF1) * PTS + SOF1 * STC2 - SOF2 * STC1) / (STC2 - STC1) (1) + * + * to avoid losing precision in the division. Similarly, the host timestamp is + * computed with + * + * TS = ((TS2 - TS1) * SOF + TS1 * SOF2 - TS2 * SOF1) / (SOF2 - SOF1) (2) + * + * SOF values are coded on 11 bits by USB. We extend their precision with 16 + * decimal bits, leading to a 11.16 coding. + * + * TODO: To avoid surprises with device clock values, PTS/STC timestamps should + * be normalized using the nominal device clock frequency reported through the + * UVC descriptors. + * + * Both the PTS/STC and SOF counters roll over, after a fixed but device + * specific amount of time for PTS/STC and after 2048ms for SOF. As long as the + * sliding window size is smaller than the rollover period, differences computed + * on unsigned integers will produce the correct result. However, the p term in + * the linear relations will be miscomputed. + * + * To fix the issue, we subtract a constant from the PTS and STC values to bring + * PTS to half the 32 bit STC range. The sliding window STC values then fit into + * the 32 bit range without any rollover. + * + * Similarly, we add 2048 to the device SOF values to make sure that the SOF + * computed by (1) will never be smaller than 0. This offset is then compensated + * by adding 2048 to the SOF values used in (2). However, this doesn't prevent + * rollovers between (1) and (2): the SOF value computed by (1) can be slightly + * lower than 4096, and the host SOF counters can have rolled over to 2048. This + * case is handled by subtracting 2048 from the SOF value if it exceeds the host + * SOF value at the end of the sliding window. + * + * Finally we subtract a constant from the host timestamps to bring the first + * timestamp of the sliding window to 1s. + */ +void uvc_video_clock_update(struct uvc_streaming *stream, + struct vb2_v4l2_buffer *vbuf, + struct uvc_buffer *buf) +{ + struct uvc_clock *clock = &stream->clock; + struct uvc_clock_sample *first; + struct uvc_clock_sample *last; + unsigned long flags; + u64 timestamp; + u32 delta_stc; + u32 y1, y2; + u32 x1, x2; + u32 mean; + u32 sof; + u64 y; + + if (!uvc_hw_timestamps_param) + return; + + /* + * We will get called from __vb2_queue_cancel() if there are buffers + * done but not dequeued by the user, but the sample array has already + * been released at that time. Just bail out in that case. + */ + if (!clock->samples) + return; + + spin_lock_irqsave(&clock->lock, flags); + + if (clock->count < clock->size) + goto done; + + first = &clock->samples[clock->head]; + last = &clock->samples[(clock->head - 1) % clock->size]; + + /* First step, PTS to SOF conversion. */ + delta_stc = buf->pts - (1UL << 31); + x1 = first->dev_stc - delta_stc; + x2 = last->dev_stc - delta_stc; + if (x1 == x2) + goto done; + + y1 = (first->dev_sof + 2048) << 16; + y2 = (last->dev_sof + 2048) << 16; + if (y2 < y1) + y2 += 2048 << 16; + + y = (u64)(y2 - y1) * (1ULL << 31) + (u64)y1 * (u64)x2 + - (u64)y2 * (u64)x1; + y = div_u64(y, x2 - x1); + + sof = y; + + uvc_trace(UVC_TRACE_CLOCK, "%s: PTS %u y %llu.%06llu SOF %u.%06llu " + "(x1 %u x2 %u y1 %u y2 %u SOF offset %u)\n", + stream->dev->name, buf->pts, + y >> 16, div_u64((y & 0xffff) * 1000000, 65536), + sof >> 16, div_u64(((u64)sof & 0xffff) * 1000000LLU, 65536), + x1, x2, y1, y2, clock->sof_offset); + + /* Second step, SOF to host clock conversion. */ + x1 = (uvc_video_clock_host_sof(first) + 2048) << 16; + x2 = (uvc_video_clock_host_sof(last) + 2048) << 16; + if (x2 < x1) + x2 += 2048 << 16; + if (x1 == x2) + goto done; + + y1 = NSEC_PER_SEC; + y2 = (u32)ktime_to_ns(ktime_sub(last->host_time, first->host_time)) + y1; + + /* Interpolated and host SOF timestamps can wrap around at slightly + * different times. Handle this by adding or removing 2048 to or from + * the computed SOF value to keep it close to the SOF samples mean + * value. + */ + mean = (x1 + x2) / 2; + if (mean - (1024 << 16) > sof) + sof += 2048 << 16; + else if (sof > mean + (1024 << 16)) + sof -= 2048 << 16; + + y = (u64)(y2 - y1) * (u64)sof + (u64)y1 * (u64)x2 + - (u64)y2 * (u64)x1; + y = div_u64(y, x2 - x1); + + timestamp = ktime_to_ns(first->host_time) + y - y1; + + uvc_trace(UVC_TRACE_CLOCK, "%s: SOF %u.%06llu y %llu ts %llu " + "buf ts %llu (x1 %u/%u/%u x2 %u/%u/%u y1 %u y2 %u)\n", + stream->dev->name, + sof >> 16, div_u64(((u64)sof & 0xffff) * 1000000LLU, 65536), + y, timestamp, vbuf->vb2_buf.timestamp, + x1, first->host_sof, first->dev_sof, + x2, last->host_sof, last->dev_sof, y1, y2); + + /* Update the V4L2 buffer. */ + vbuf->vb2_buf.timestamp = timestamp; + +done: + spin_unlock_irqrestore(&clock->lock, flags); +} + +/* ------------------------------------------------------------------------ + * Stream statistics + */ + +static void uvc_video_stats_decode(struct uvc_streaming *stream, + const u8 *data, int len) +{ + unsigned int header_size; + bool has_pts = false; + bool has_scr = false; + u16 scr_sof; + u32 scr_stc; + u32 pts; + + if (stream->stats.stream.nb_frames == 0 && + stream->stats.frame.nb_packets == 0) + stream->stats.stream.start_ts = ktime_get(); + + switch (data[1] & (UVC_STREAM_PTS | UVC_STREAM_SCR)) { + case UVC_STREAM_PTS | UVC_STREAM_SCR: + header_size = 12; + has_pts = true; + has_scr = true; + break; + case UVC_STREAM_PTS: + header_size = 6; + has_pts = true; + break; + case UVC_STREAM_SCR: + header_size = 8; + has_scr = true; + break; + default: + header_size = 2; + break; + } + + /* Check for invalid headers. */ + if (len < header_size || data[0] < header_size) { + stream->stats.frame.nb_invalid++; + return; + } + + /* Extract the timestamps. */ + if (has_pts) + pts = get_unaligned_le32(&data[2]); + + if (has_scr) { + scr_stc = get_unaligned_le32(&data[header_size - 6]); + scr_sof = get_unaligned_le16(&data[header_size - 2]); + } + + /* Is PTS constant through the whole frame ? */ + if (has_pts && stream->stats.frame.nb_pts) { + if (stream->stats.frame.pts != pts) { + stream->stats.frame.nb_pts_diffs++; + stream->stats.frame.last_pts_diff = + stream->stats.frame.nb_packets; + } + } + + if (has_pts) { + stream->stats.frame.nb_pts++; + stream->stats.frame.pts = pts; + } + + /* Do all frames have a PTS in their first non-empty packet, or before + * their first empty packet ? + */ + if (stream->stats.frame.size == 0) { + if (len > header_size) + stream->stats.frame.has_initial_pts = has_pts; + if (len == header_size && has_pts) + stream->stats.frame.has_early_pts = true; + } + + /* Do the SCR.STC and SCR.SOF fields vary through the frame ? */ + if (has_scr && stream->stats.frame.nb_scr) { + if (stream->stats.frame.scr_stc != scr_stc) + stream->stats.frame.nb_scr_diffs++; + } + + if (has_scr) { + /* Expand the SOF counter to 32 bits and store its value. */ + if (stream->stats.stream.nb_frames > 0 || + stream->stats.frame.nb_scr > 0) + stream->stats.stream.scr_sof_count += + (scr_sof - stream->stats.stream.scr_sof) % 2048; + stream->stats.stream.scr_sof = scr_sof; + + stream->stats.frame.nb_scr++; + stream->stats.frame.scr_stc = scr_stc; + stream->stats.frame.scr_sof = scr_sof; + + if (scr_sof < stream->stats.stream.min_sof) + stream->stats.stream.min_sof = scr_sof; + if (scr_sof > stream->stats.stream.max_sof) + stream->stats.stream.max_sof = scr_sof; + } + + /* Record the first non-empty packet number. */ + if (stream->stats.frame.size == 0 && len > header_size) + stream->stats.frame.first_data = stream->stats.frame.nb_packets; + + /* Update the frame size. */ + stream->stats.frame.size += len - header_size; + + /* Update the packets counters. */ + stream->stats.frame.nb_packets++; + if (len <= header_size) + stream->stats.frame.nb_empty++; + + if (data[1] & UVC_STREAM_ERR) + stream->stats.frame.nb_errors++; +} + +static void uvc_video_stats_update(struct uvc_streaming *stream) +{ + struct uvc_stats_frame *frame = &stream->stats.frame; + + uvc_trace(UVC_TRACE_STATS, "frame %u stats: %u/%u/%u packets, " + "%u/%u/%u pts (%searly %sinitial), %u/%u scr, " + "last pts/stc/sof %u/%u/%u\n", + stream->sequence, frame->first_data, + frame->nb_packets - frame->nb_empty, frame->nb_packets, + frame->nb_pts_diffs, frame->last_pts_diff, frame->nb_pts, + frame->has_early_pts ? "" : "!", + frame->has_initial_pts ? "" : "!", + frame->nb_scr_diffs, frame->nb_scr, + frame->pts, frame->scr_stc, frame->scr_sof); + + stream->stats.stream.nb_frames++; + stream->stats.stream.nb_packets += stream->stats.frame.nb_packets; + stream->stats.stream.nb_empty += stream->stats.frame.nb_empty; + stream->stats.stream.nb_errors += stream->stats.frame.nb_errors; + stream->stats.stream.nb_invalid += stream->stats.frame.nb_invalid; + + if (frame->has_early_pts) + stream->stats.stream.nb_pts_early++; + if (frame->has_initial_pts) + stream->stats.stream.nb_pts_initial++; + if (frame->last_pts_diff <= frame->first_data) + stream->stats.stream.nb_pts_constant++; + if (frame->nb_scr >= frame->nb_packets - frame->nb_empty) + stream->stats.stream.nb_scr_count_ok++; + if (frame->nb_scr_diffs + 1 == frame->nb_scr) + stream->stats.stream.nb_scr_diffs_ok++; + + memset(&stream->stats.frame, 0, sizeof(stream->stats.frame)); +} + +size_t uvc_video_stats_dump(struct uvc_streaming *stream, char *buf, + size_t size) +{ + unsigned int scr_sof_freq; + unsigned int duration; + size_t count = 0; + + /* Compute the SCR.SOF frequency estimate. At the nominal 1kHz SOF + * frequency this will not overflow before more than 1h. + */ + duration = ktime_ms_delta(stream->stats.stream.stop_ts, + stream->stats.stream.start_ts); + if (duration != 0) + scr_sof_freq = stream->stats.stream.scr_sof_count * 1000 + / duration; + else + scr_sof_freq = 0; + + count += scnprintf(buf + count, size - count, + "frames: %u\npackets: %u\nempty: %u\n" + "errors: %u\ninvalid: %u\n", + stream->stats.stream.nb_frames, + stream->stats.stream.nb_packets, + stream->stats.stream.nb_empty, + stream->stats.stream.nb_errors, + stream->stats.stream.nb_invalid); + count += scnprintf(buf + count, size - count, + "pts: %u early, %u initial, %u ok\n", + stream->stats.stream.nb_pts_early, + stream->stats.stream.nb_pts_initial, + stream->stats.stream.nb_pts_constant); + count += scnprintf(buf + count, size - count, + "scr: %u count ok, %u diff ok\n", + stream->stats.stream.nb_scr_count_ok, + stream->stats.stream.nb_scr_diffs_ok); + count += scnprintf(buf + count, size - count, + "sof: %u <= sof <= %u, freq %u.%03u kHz\n", + stream->stats.stream.min_sof, + stream->stats.stream.max_sof, + scr_sof_freq / 1000, scr_sof_freq % 1000); + + return count; +} + +static void uvc_video_stats_start(struct uvc_streaming *stream) +{ + memset(&stream->stats, 0, sizeof(stream->stats)); + stream->stats.stream.min_sof = 2048; +} + +static void uvc_video_stats_stop(struct uvc_streaming *stream) +{ + stream->stats.stream.stop_ts = ktime_get(); +} + +/* ------------------------------------------------------------------------ + * Video codecs + */ + +/* Video payload decoding is handled by uvc_video_decode_start(), + * uvc_video_decode_data() and uvc_video_decode_end(). + * + * uvc_video_decode_start is called with URB data at the start of a bulk or + * isochronous payload. It processes header data and returns the header size + * in bytes if successful. If an error occurs, it returns a negative error + * code. The following error codes have special meanings. + * + * - EAGAIN informs the caller that the current video buffer should be marked + * as done, and that the function should be called again with the same data + * and a new video buffer. This is used when end of frame conditions can be + * reliably detected at the beginning of the next frame only. + * + * If an error other than -EAGAIN is returned, the caller will drop the current + * payload. No call to uvc_video_decode_data and uvc_video_decode_end will be + * made until the next payload. -ENODATA can be used to drop the current + * payload if no other error code is appropriate. + * + * uvc_video_decode_data is called for every URB with URB data. It copies the + * data to the video buffer. + * + * uvc_video_decode_end is called with header data at the end of a bulk or + * isochronous payload. It performs any additional header data processing and + * returns 0 or a negative error code if an error occurred. As header data have + * already been processed by uvc_video_decode_start, this functions isn't + * required to perform sanity checks a second time. + * + * For isochronous transfers where a payload is always transferred in a single + * URB, the three functions will be called in a row. + * + * To let the decoder process header data and update its internal state even + * when no video buffer is available, uvc_video_decode_start must be prepared + * to be called with a NULL buf parameter. uvc_video_decode_data and + * uvc_video_decode_end will never be called with a NULL buffer. + */ +static int uvc_video_decode_start(struct uvc_streaming *stream, + struct uvc_buffer *buf, const u8 *data, int len) +{ + u8 fid; + + /* Sanity checks: + * - packet must be at least 2 bytes long + * - bHeaderLength value must be at least 2 bytes (see above) + * - bHeaderLength value can't be larger than the packet size. + */ + if (len < 2 || data[0] < 2 || data[0] > len) { + stream->stats.frame.nb_invalid++; + return -EINVAL; + } + + fid = data[1] & UVC_STREAM_FID; + + /* Increase the sequence number regardless of any buffer states, so + * that discontinuous sequence numbers always indicate lost frames. + */ + if (stream->last_fid != fid) { + stream->sequence++; + if (stream->sequence) + uvc_video_stats_update(stream); + } + + uvc_video_clock_decode(stream, buf, data, len); + uvc_video_stats_decode(stream, data, len); + + /* Store the payload FID bit and return immediately when the buffer is + * NULL. + */ + if (buf == NULL) { + stream->last_fid = fid; + return -ENODATA; + } + + /* Mark the buffer as bad if the error bit is set. */ + if (data[1] & UVC_STREAM_ERR) { + uvc_trace(UVC_TRACE_FRAME, "Marking buffer as bad (error bit " + "set).\n"); + buf->error = 1; + } + + /* Synchronize to the input stream by waiting for the FID bit to be + * toggled when the the buffer state is not UVC_BUF_STATE_ACTIVE. + * stream->last_fid is initialized to -1, so the first isochronous + * frame will always be in sync. + * + * If the device doesn't toggle the FID bit, invert stream->last_fid + * when the EOF bit is set to force synchronisation on the next packet. + */ + if (buf->state != UVC_BUF_STATE_ACTIVE) { + if (fid == stream->last_fid) { + uvc_trace(UVC_TRACE_FRAME, "Dropping payload (out of " + "sync).\n"); + if ((stream->dev->quirks & UVC_QUIRK_STREAM_NO_FID) && + (data[1] & UVC_STREAM_EOF)) + stream->last_fid ^= UVC_STREAM_FID; + return -ENODATA; + } + + buf->buf.field = V4L2_FIELD_NONE; + buf->buf.sequence = stream->sequence; + buf->buf.vb2_buf.timestamp = ktime_to_ns(uvc_video_get_time()); + + /* TODO: Handle PTS and SCR. */ + buf->state = UVC_BUF_STATE_ACTIVE; + } + + /* Mark the buffer as done if we're at the beginning of a new frame. + * End of frame detection is better implemented by checking the EOF + * bit (FID bit toggling is delayed by one frame compared to the EOF + * bit), but some devices don't set the bit at end of frame (and the + * last payload can be lost anyway). We thus must check if the FID has + * been toggled. + * + * stream->last_fid is initialized to -1, so the first isochronous + * frame will never trigger an end of frame detection. + * + * Empty buffers (bytesused == 0) don't trigger end of frame detection + * as it doesn't make sense to return an empty buffer. This also + * avoids detecting end of frame conditions at FID toggling if the + * previous payload had the EOF bit set. + */ + if (fid != stream->last_fid && buf->bytesused != 0) { + uvc_trace(UVC_TRACE_FRAME, "Frame complete (FID bit " + "toggled).\n"); + buf->state = UVC_BUF_STATE_READY; + return -EAGAIN; + } + + stream->last_fid = fid; + + return data[0]; +} + +/* + * uvc_video_decode_data_work: Asynchronous memcpy processing + * + * Copy URB data to video buffers in process context, releasing buffer + * references and requeuing the URB when done. + */ +static void uvc_video_copy_data_work(struct work_struct *work) +{ + struct uvc_urb *uvc_urb = container_of(work, struct uvc_urb, work); + unsigned int i; + int ret; + + for (i = 0; i < uvc_urb->async_operations; i++) { + struct uvc_copy_op *op = &uvc_urb->copy_operations[i]; + + memcpy(op->dst, op->src, op->len); + + /* Release reference taken on this buffer. */ + uvc_queue_buffer_release(op->buf); + } + + ret = usb_submit_urb(uvc_urb->urb, GFP_KERNEL); + if (ret < 0) + uvc_printk(KERN_ERR, "Failed to resubmit video URB (%d).\n", + ret); +} + +static void uvc_video_decode_data(struct uvc_urb *uvc_urb, + struct uvc_buffer *buf, const u8 *data, int len) +{ + unsigned int active_op = uvc_urb->async_operations; + struct uvc_copy_op *op = &uvc_urb->copy_operations[active_op]; + unsigned int maxlen; + + if (len <= 0) + return; + + maxlen = buf->length - buf->bytesused; + + /* Take a buffer reference for async work. */ + kref_get(&buf->ref); + + op->buf = buf; + op->src = data; + op->dst = buf->mem + buf->bytesused; + op->len = min_t(unsigned int, len, maxlen); + + buf->bytesused += op->len; + + /* Complete the current frame if the buffer size was exceeded. */ + if (len > maxlen) { + uvc_trace(UVC_TRACE_FRAME, "Frame complete (overflow).\n"); + buf->error = 1; + buf->state = UVC_BUF_STATE_READY; + } + + uvc_urb->async_operations++; +} + +static void uvc_video_decode_end(struct uvc_streaming *stream, + struct uvc_buffer *buf, const u8 *data, int len) +{ + /* Mark the buffer as done if the EOF marker is set. */ + if (data[1] & UVC_STREAM_EOF && buf->bytesused != 0) { + uvc_trace(UVC_TRACE_FRAME, "Frame complete (EOF found).\n"); + if (data[0] == len) + uvc_trace(UVC_TRACE_FRAME, "EOF in empty payload.\n"); + buf->state = UVC_BUF_STATE_READY; + if (stream->dev->quirks & UVC_QUIRK_STREAM_NO_FID) + stream->last_fid ^= UVC_STREAM_FID; + } +} + +/* Video payload encoding is handled by uvc_video_encode_header() and + * uvc_video_encode_data(). Only bulk transfers are currently supported. + * + * uvc_video_encode_header is called at the start of a payload. It adds header + * data to the transfer buffer and returns the header size. As the only known + * UVC output device transfers a whole frame in a single payload, the EOF bit + * is always set in the header. + * + * uvc_video_encode_data is called for every URB and copies the data from the + * video buffer to the transfer buffer. + */ +static int uvc_video_encode_header(struct uvc_streaming *stream, + struct uvc_buffer *buf, u8 *data, int len) +{ + data[0] = 2; /* Header length */ + data[1] = UVC_STREAM_EOH | UVC_STREAM_EOF + | (stream->last_fid & UVC_STREAM_FID); + return 2; +} + +static int uvc_video_encode_data(struct uvc_streaming *stream, + struct uvc_buffer *buf, u8 *data, int len) +{ + struct uvc_video_queue *queue = &stream->queue; + unsigned int nbytes; + void *mem; + + /* Copy video data to the URB buffer. */ + mem = buf->mem + queue->buf_used; + nbytes = min((unsigned int)len, buf->bytesused - queue->buf_used); + nbytes = min(stream->bulk.max_payload_size - stream->bulk.payload_size, + nbytes); + memcpy(data, mem, nbytes); + + queue->buf_used += nbytes; + + return nbytes; +} + +/* ------------------------------------------------------------------------ + * Metadata + */ + +/* + * Additionally to the payload headers we also want to provide the user with USB + * Frame Numbers and system time values. The resulting buffer is thus composed + * of blocks, containing a 64-bit timestamp in nanoseconds, a 16-bit USB Frame + * Number, and a copy of the payload header. + * + * Ideally we want to capture all payload headers for each frame. However, their + * number is unknown and unbound. We thus drop headers that contain no vendor + * data and that either contain no SCR value or an SCR value identical to the + * previous header. + */ +static void uvc_video_decode_meta(struct uvc_streaming *stream, + struct uvc_buffer *meta_buf, + const u8 *mem, unsigned int length) +{ + struct uvc_meta_buf *meta; + size_t len_std = 2; + bool has_pts, has_scr; + unsigned long flags; + unsigned int sof; + ktime_t time; + const u8 *scr; + + if (!meta_buf || length == 2) + return; + + if (meta_buf->length - meta_buf->bytesused < + length + sizeof(meta->ns) + sizeof(meta->sof)) { + meta_buf->error = 1; + return; + } + + has_pts = mem[1] & UVC_STREAM_PTS; + has_scr = mem[1] & UVC_STREAM_SCR; + + if (has_pts) { + len_std += 4; + scr = mem + 6; + } else { + scr = mem + 2; + } + + if (has_scr) + len_std += 6; + + if (stream->meta.format == V4L2_META_FMT_UVC) + length = len_std; + + if (length == len_std && (!has_scr || + !memcmp(scr, stream->clock.last_scr, 6))) + return; + + meta = (struct uvc_meta_buf *)((u8 *)meta_buf->mem + meta_buf->bytesused); + local_irq_save(flags); + time = uvc_video_get_time(); + sof = usb_get_current_frame_number(stream->dev->udev); + local_irq_restore(flags); + put_unaligned(ktime_to_ns(time), &meta->ns); + put_unaligned(sof, &meta->sof); + + if (has_scr) + memcpy(stream->clock.last_scr, scr, 6); + + meta->length = mem[0]; + meta->flags = mem[1]; + memcpy(meta->buf, &mem[2], length - 2); + meta_buf->bytesused += length + sizeof(meta->ns) + sizeof(meta->sof); + + uvc_trace(UVC_TRACE_FRAME, + "%s(): t-sys %lluns, SOF %u, len %u, flags 0x%x, PTS %u, STC %u frame SOF %u\n", + __func__, ktime_to_ns(time), meta->sof, meta->length, + meta->flags, + has_pts ? *(u32 *)meta->buf : 0, + has_scr ? *(u32 *)scr : 0, + has_scr ? *(u32 *)(scr + 4) & 0x7ff : 0); +} + +/* ------------------------------------------------------------------------ + * URB handling + */ + +/* + * Set error flag for incomplete buffer. + */ +static void uvc_video_validate_buffer(const struct uvc_streaming *stream, + struct uvc_buffer *buf) +{ + if (stream->ctrl.dwMaxVideoFrameSize != buf->bytesused && + !(stream->cur_format->flags & UVC_FMT_FLAG_COMPRESSED)) + buf->error = 1; +} + +/* + * Completion handler for video URBs. + */ + +static void uvc_video_next_buffers(struct uvc_streaming *stream, + struct uvc_buffer **video_buf, struct uvc_buffer **meta_buf) +{ + uvc_video_validate_buffer(stream, *video_buf); + + if (*meta_buf) { + struct vb2_v4l2_buffer *vb2_meta = &(*meta_buf)->buf; + const struct vb2_v4l2_buffer *vb2_video = &(*video_buf)->buf; + + vb2_meta->sequence = vb2_video->sequence; + vb2_meta->field = vb2_video->field; + vb2_meta->vb2_buf.timestamp = vb2_video->vb2_buf.timestamp; + + (*meta_buf)->state = UVC_BUF_STATE_READY; + if (!(*meta_buf)->error) + (*meta_buf)->error = (*video_buf)->error; + *meta_buf = uvc_queue_next_buffer(&stream->meta.queue, + *meta_buf); + } + *video_buf = uvc_queue_next_buffer(&stream->queue, *video_buf); +} + +static void uvc_video_decode_isoc(struct uvc_urb *uvc_urb, + struct uvc_buffer *buf, struct uvc_buffer *meta_buf) +{ + struct urb *urb = uvc_urb->urb; + struct uvc_streaming *stream = uvc_urb->stream; + u8 *mem; + int ret, i; + + for (i = 0; i < urb->number_of_packets; ++i) { + if (urb->iso_frame_desc[i].status < 0) { + uvc_trace(UVC_TRACE_FRAME, "USB isochronous frame " + "lost (%d).\n", urb->iso_frame_desc[i].status); + /* Mark the buffer as faulty. */ + if (buf != NULL) + buf->error = 1; + continue; + } + + /* Decode the payload header. */ + mem = urb->transfer_buffer + urb->iso_frame_desc[i].offset; + do { + ret = uvc_video_decode_start(stream, buf, mem, + urb->iso_frame_desc[i].actual_length); + if (ret == -EAGAIN) + uvc_video_next_buffers(stream, &buf, &meta_buf); + } while (ret == -EAGAIN); + + if (ret < 0) + continue; + + uvc_video_decode_meta(stream, meta_buf, mem, ret); + + /* Decode the payload data. */ + uvc_video_decode_data(uvc_urb, buf, mem + ret, + urb->iso_frame_desc[i].actual_length - ret); + + /* Process the header again. */ + uvc_video_decode_end(stream, buf, mem, + urb->iso_frame_desc[i].actual_length); + + if (buf->state == UVC_BUF_STATE_READY) + uvc_video_next_buffers(stream, &buf, &meta_buf); + } +} + +static void uvc_video_decode_bulk(struct uvc_urb *uvc_urb, + struct uvc_buffer *buf, struct uvc_buffer *meta_buf) +{ + struct urb *urb = uvc_urb->urb; + struct uvc_streaming *stream = uvc_urb->stream; + u8 *mem; + int len, ret; + + /* + * Ignore ZLPs if they're not part of a frame, otherwise process them + * to trigger the end of payload detection. + */ + if (urb->actual_length == 0 && stream->bulk.header_size == 0) + return; + + mem = urb->transfer_buffer; + len = urb->actual_length; + stream->bulk.payload_size += len; + + /* If the URB is the first of its payload, decode and save the + * header. + */ + if (stream->bulk.header_size == 0 && !stream->bulk.skip_payload) { + do { + ret = uvc_video_decode_start(stream, buf, mem, len); + if (ret == -EAGAIN) + uvc_video_next_buffers(stream, &buf, &meta_buf); + } while (ret == -EAGAIN); + + /* If an error occurred skip the rest of the payload. */ + if (ret < 0 || buf == NULL) { + stream->bulk.skip_payload = 1; + } else { + memcpy(stream->bulk.header, mem, ret); + stream->bulk.header_size = ret; + + uvc_video_decode_meta(stream, meta_buf, mem, ret); + + mem += ret; + len -= ret; + } + } + + /* The buffer queue might have been cancelled while a bulk transfer + * was in progress, so we can reach here with buf equal to NULL. Make + * sure buf is never dereferenced if NULL. + */ + + /* Prepare video data for processing. */ + if (!stream->bulk.skip_payload && buf != NULL) + uvc_video_decode_data(uvc_urb, buf, mem, len); + + /* Detect the payload end by a URB smaller than the maximum size (or + * a payload size equal to the maximum) and process the header again. + */ + if (urb->actual_length < urb->transfer_buffer_length || + stream->bulk.payload_size >= stream->bulk.max_payload_size) { + if (!stream->bulk.skip_payload && buf != NULL) { + uvc_video_decode_end(stream, buf, stream->bulk.header, + stream->bulk.payload_size); + if (buf->state == UVC_BUF_STATE_READY) + uvc_video_next_buffers(stream, &buf, &meta_buf); + } + + stream->bulk.header_size = 0; + stream->bulk.skip_payload = 0; + stream->bulk.payload_size = 0; + } +} + +static void uvc_video_encode_bulk(struct uvc_urb *uvc_urb, + struct uvc_buffer *buf, struct uvc_buffer *meta_buf) +{ + struct urb *urb = uvc_urb->urb; + struct uvc_streaming *stream = uvc_urb->stream; + + u8 *mem = urb->transfer_buffer; + int len = stream->urb_size, ret; + + if (buf == NULL) { + urb->transfer_buffer_length = 0; + return; + } + + /* If the URB is the first of its payload, add the header. */ + if (stream->bulk.header_size == 0) { + ret = uvc_video_encode_header(stream, buf, mem, len); + stream->bulk.header_size = ret; + stream->bulk.payload_size += ret; + mem += ret; + len -= ret; + } + + /* Process video data. */ + ret = uvc_video_encode_data(stream, buf, mem, len); + + stream->bulk.payload_size += ret; + len -= ret; + + if (buf->bytesused == stream->queue.buf_used || + stream->bulk.payload_size == stream->bulk.max_payload_size) { + if (buf->bytesused == stream->queue.buf_used) { + stream->queue.buf_used = 0; + buf->state = UVC_BUF_STATE_READY; + buf->buf.sequence = ++stream->sequence; + uvc_queue_next_buffer(&stream->queue, buf); + stream->last_fid ^= UVC_STREAM_FID; + } + + stream->bulk.header_size = 0; + stream->bulk.payload_size = 0; + } + + urb->transfer_buffer_length = stream->urb_size - len; +} + +static void uvc_video_complete(struct urb *urb) +{ + struct uvc_urb *uvc_urb = urb->context; + struct uvc_streaming *stream = uvc_urb->stream; + struct uvc_video_queue *queue = &stream->queue; + struct uvc_video_queue *qmeta = &stream->meta.queue; + struct vb2_queue *vb2_qmeta = stream->meta.vdev.queue; + struct uvc_buffer *buf = NULL; + struct uvc_buffer *buf_meta = NULL; + unsigned long flags; + int ret; + + switch (urb->status) { + case 0: + break; + + default: + uvc_printk(KERN_WARNING, "Non-zero status (%d) in video " + "completion handler.\n", urb->status); + fallthrough; + case -ENOENT: /* usb_poison_urb() called. */ + if (stream->frozen) + return; + fallthrough; + case -ECONNRESET: /* usb_unlink_urb() called. */ + case -ESHUTDOWN: /* The endpoint is being disabled. */ + uvc_queue_cancel(queue, urb->status == -ESHUTDOWN); + if (vb2_qmeta) + uvc_queue_cancel(qmeta, urb->status == -ESHUTDOWN); + return; + } + + buf = uvc_queue_get_current_buffer(queue); + + if (vb2_qmeta) { + spin_lock_irqsave(&qmeta->irqlock, flags); + if (!list_empty(&qmeta->irqqueue)) + buf_meta = list_first_entry(&qmeta->irqqueue, + struct uvc_buffer, queue); + spin_unlock_irqrestore(&qmeta->irqlock, flags); + } + + /* Re-initialise the URB async work. */ + uvc_urb->async_operations = 0; + + /* + * Process the URB headers, and optionally queue expensive memcpy tasks + * to be deferred to a work queue. + */ + stream->decode(uvc_urb, buf, buf_meta); + + /* If no async work is needed, resubmit the URB immediately. */ + if (!uvc_urb->async_operations) { + ret = usb_submit_urb(uvc_urb->urb, GFP_ATOMIC); + if (ret < 0) + uvc_printk(KERN_ERR, + "Failed to resubmit video URB (%d).\n", + ret); + return; + } + + queue_work(stream->async_wq, &uvc_urb->work); +} + +/* + * Free transfer buffers. + */ +static void uvc_free_urb_buffers(struct uvc_streaming *stream) +{ + struct uvc_urb *uvc_urb; + + for_each_uvc_urb(uvc_urb, stream) { + if (!uvc_urb->buffer) + continue; + +#ifndef CONFIG_DMA_NONCOHERENT + usb_free_coherent(stream->dev->udev, stream->urb_size, + uvc_urb->buffer, uvc_urb->dma); +#else + kfree(uvc_urb->buffer); +#endif + uvc_urb->buffer = NULL; + } + + stream->urb_size = 0; +} + +/* + * Allocate transfer buffers. This function can be called with buffers + * already allocated when resuming from suspend, in which case it will + * return without touching the buffers. + * + * Limit the buffer size to UVC_MAX_PACKETS bulk/isochronous packets. If the + * system is too low on memory try successively smaller numbers of packets + * until allocation succeeds. + * + * Return the number of allocated packets on success or 0 when out of memory. + */ +static int uvc_alloc_urb_buffers(struct uvc_streaming *stream, + unsigned int size, unsigned int psize, gfp_t gfp_flags) +{ + unsigned int npackets; + unsigned int i; + + /* Buffers are already allocated, bail out. */ + if (stream->urb_size) + return stream->urb_size / psize; + + /* Compute the number of packets. Bulk endpoints might transfer UVC + * payloads across multiple URBs. + */ + npackets = DIV_ROUND_UP(size, psize); + if (npackets > UVC_MAX_PACKETS) + npackets = UVC_MAX_PACKETS; + + /* Retry allocations until one succeed. */ + for (; npackets > 1; npackets /= 2) { + for (i = 0; i < UVC_URBS; ++i) { + struct uvc_urb *uvc_urb = &stream->uvc_urb[i]; + + stream->urb_size = psize * npackets; +#ifndef CONFIG_DMA_NONCOHERENT + uvc_urb->buffer = usb_alloc_coherent( + stream->dev->udev, stream->urb_size, + gfp_flags | __GFP_NOWARN, &uvc_urb->dma); +#else + uvc_urb->buffer = + kmalloc(stream->urb_size, gfp_flags | __GFP_NOWARN); +#endif + if (!uvc_urb->buffer) { + uvc_free_urb_buffers(stream); + break; + } + + uvc_urb->stream = stream; + } + + if (i == UVC_URBS) { + uvc_trace(UVC_TRACE_VIDEO, "Allocated %u URB buffers " + "of %ux%u bytes each.\n", UVC_URBS, npackets, + psize); + return npackets; + } + } + + uvc_trace(UVC_TRACE_VIDEO, "Failed to allocate URB buffers (%u bytes " + "per packet).\n", psize); + return 0; +} + +/* + * Uninitialize isochronous/bulk URBs and free transfer buffers. + */ +static void uvc_video_stop_transfer(struct uvc_streaming *stream, + int free_buffers) +{ + struct uvc_urb *uvc_urb; + + uvc_video_stats_stop(stream); + + /* + * We must poison the URBs rather than kill them to ensure that even + * after the completion handler returns, any asynchronous workqueues + * will be prevented from resubmitting the URBs. + */ + for_each_uvc_urb(uvc_urb, stream) + usb_poison_urb(uvc_urb->urb); + + flush_workqueue(stream->async_wq); + + for_each_uvc_urb(uvc_urb, stream) { + usb_free_urb(uvc_urb->urb); + uvc_urb->urb = NULL; + } + + if (free_buffers) + uvc_free_urb_buffers(stream); +} + +/* + * Compute the maximum number of bytes per interval for an endpoint. + */ +static unsigned int uvc_endpoint_max_bpi(struct usb_device *dev, + struct usb_host_endpoint *ep) +{ + u16 psize; + u16 mult; + + switch (dev->speed) { + case USB_SPEED_SUPER: + case USB_SPEED_SUPER_PLUS: + return le16_to_cpu(ep->ss_ep_comp.wBytesPerInterval); + case USB_SPEED_HIGH: + psize = usb_endpoint_maxp(&ep->desc); + mult = usb_endpoint_maxp_mult(&ep->desc); + return psize * mult; + case USB_SPEED_WIRELESS: + psize = usb_endpoint_maxp(&ep->desc); + return psize; + default: + psize = usb_endpoint_maxp(&ep->desc); + return psize; + } +} + +/* + * Initialize isochronous URBs and allocate transfer buffers. The packet size + * is given by the endpoint. + */ +static int uvc_init_video_isoc(struct uvc_streaming *stream, + struct usb_host_endpoint *ep, gfp_t gfp_flags) +{ + struct urb *urb; + struct uvc_urb *uvc_urb; + unsigned int npackets, i; + u16 psize; + u32 size; + + psize = uvc_endpoint_max_bpi(stream->dev->udev, ep); + size = stream->ctrl.dwMaxVideoFrameSize; + + npackets = uvc_alloc_urb_buffers(stream, size, psize, gfp_flags); + if (npackets == 0) + return -ENOMEM; + + size = npackets * psize; + + for_each_uvc_urb(uvc_urb, stream) { + urb = usb_alloc_urb(npackets, gfp_flags); + if (urb == NULL) { + uvc_video_stop_transfer(stream, 1); + return -ENOMEM; + } + + urb->dev = stream->dev->udev; + urb->context = uvc_urb; + urb->pipe = usb_rcvisocpipe(stream->dev->udev, + ep->desc.bEndpointAddress); +#ifndef CONFIG_DMA_NONCOHERENT + urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP; + urb->transfer_dma = uvc_urb->dma; +#else + urb->transfer_flags = URB_ISO_ASAP; +#endif + urb->interval = ep->desc.bInterval; + urb->transfer_buffer = uvc_urb->buffer; + urb->complete = uvc_video_complete; + urb->number_of_packets = npackets; + urb->transfer_buffer_length = size; + + for (i = 0; i < npackets; ++i) { + urb->iso_frame_desc[i].offset = i * psize; + urb->iso_frame_desc[i].length = psize; + } + + uvc_urb->urb = urb; + } + + return 0; +} + +/* + * Initialize bulk URBs and allocate transfer buffers. The packet size is + * given by the endpoint. + */ +static int uvc_init_video_bulk(struct uvc_streaming *stream, + struct usb_host_endpoint *ep, gfp_t gfp_flags) +{ + struct urb *urb; + struct uvc_urb *uvc_urb; + unsigned int npackets, pipe; + u16 psize; + u32 size; + + psize = usb_endpoint_maxp(&ep->desc); + size = stream->ctrl.dwMaxPayloadTransferSize; + stream->bulk.max_payload_size = size; + + npackets = uvc_alloc_urb_buffers(stream, size, psize, gfp_flags); + if (npackets == 0) + return -ENOMEM; + + size = npackets * psize; + + if (usb_endpoint_dir_in(&ep->desc)) + pipe = usb_rcvbulkpipe(stream->dev->udev, + ep->desc.bEndpointAddress); + else + pipe = usb_sndbulkpipe(stream->dev->udev, + ep->desc.bEndpointAddress); + + if (stream->type == V4L2_BUF_TYPE_VIDEO_OUTPUT) + size = 0; + + for_each_uvc_urb(uvc_urb, stream) { + urb = usb_alloc_urb(0, gfp_flags); + if (urb == NULL) { + uvc_video_stop_transfer(stream, 1); + return -ENOMEM; + } + + usb_fill_bulk_urb(urb, stream->dev->udev, pipe, uvc_urb->buffer, + size, uvc_video_complete, uvc_urb); +#ifndef CONFIG_DMA_NONCOHERENT + urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP; + urb->transfer_dma = uvc_urb->dma; +#endif + + uvc_urb->urb = urb; + } + + return 0; +} + +/* + * Initialize isochronous/bulk URBs and allocate transfer buffers. + */ +static int uvc_video_start_transfer(struct uvc_streaming *stream, + gfp_t gfp_flags) +{ + struct usb_interface *intf = stream->intf; + struct usb_host_endpoint *ep; + struct uvc_urb *uvc_urb; + unsigned int i; + int ret; + + stream->sequence = -1; + stream->last_fid = -1; + stream->bulk.header_size = 0; + stream->bulk.skip_payload = 0; + stream->bulk.payload_size = 0; + + uvc_video_stats_start(stream); + + if (intf->num_altsetting > 1) { + struct usb_host_endpoint *best_ep = NULL; + unsigned int best_psize = UINT_MAX; + unsigned int bandwidth; + unsigned int altsetting; + int intfnum = stream->intfnum; + + /* Isochronous endpoint, select the alternate setting. */ + bandwidth = stream->ctrl.dwMaxPayloadTransferSize; + + if (bandwidth == 0) { + uvc_trace(UVC_TRACE_VIDEO, "Device requested null " + "bandwidth, defaulting to lowest.\n"); + bandwidth = 1; + } else { + uvc_trace(UVC_TRACE_VIDEO, "Device requested %u " + "B/frame bandwidth.\n", bandwidth); + } + + for (i = 0; i < intf->num_altsetting; ++i) { + struct usb_host_interface *alts; + unsigned int psize; + + alts = &intf->altsetting[i]; + ep = uvc_find_endpoint(alts, + stream->header.bEndpointAddress); + if (ep == NULL) + continue; + + /* Check if the bandwidth is high enough. */ + psize = uvc_endpoint_max_bpi(stream->dev->udev, ep); + if (psize >= bandwidth && psize <= best_psize) { + altsetting = alts->desc.bAlternateSetting; + best_psize = psize; + best_ep = ep; + } + } + + if (best_ep == NULL) { + uvc_trace(UVC_TRACE_VIDEO, "No fast enough alt setting " + "for requested bandwidth.\n"); + return -EIO; + } + + uvc_trace(UVC_TRACE_VIDEO, "Selecting alternate setting %u " + "(%u B/frame bandwidth).\n", altsetting, best_psize); + + /* + * Some devices, namely the Logitech C910 and B910, are unable + * to recover from a USB autosuspend, unless the alternate + * setting of the streaming interface is toggled. + */ + if (stream->dev->quirks & UVC_QUIRK_WAKE_AUTOSUSPEND) { + usb_set_interface(stream->dev->udev, intfnum, + altsetting); + usb_set_interface(stream->dev->udev, intfnum, 0); + } + + ret = usb_set_interface(stream->dev->udev, intfnum, altsetting); + if (ret < 0) + return ret; + + ret = uvc_init_video_isoc(stream, best_ep, gfp_flags); + } else { + /* Bulk endpoint, proceed to URB initialization. */ + ep = uvc_find_endpoint(&intf->altsetting[0], + stream->header.bEndpointAddress); + if (ep == NULL) + return -EIO; + + /* Reject broken descriptors. */ + if (usb_endpoint_maxp(&ep->desc) == 0) + return -EIO; + + ret = uvc_init_video_bulk(stream, ep, gfp_flags); + } + + if (ret < 0) + return ret; + + /* Submit the URBs. */ + for_each_uvc_urb(uvc_urb, stream) { + ret = usb_submit_urb(uvc_urb->urb, gfp_flags); + if (ret < 0) { + uvc_printk(KERN_ERR, "Failed to submit URB %u (%d).\n", + uvc_urb_index(uvc_urb), ret); + uvc_video_stop_transfer(stream, 1); + return ret; + } + } + + /* The Logitech C920 temporarily forgets that it should not be adjusting + * Exposure Absolute during init so restore controls to stored values. + */ + if (stream->dev->quirks & UVC_QUIRK_RESTORE_CTRLS_ON_INIT) + uvc_ctrl_restore_values(stream->dev); + + return 0; +} + +/* -------------------------------------------------------------------------- + * Suspend/resume + */ + +/* + * Stop streaming without disabling the video queue. + * + * To let userspace applications resume without trouble, we must not touch the + * video buffers in any way. We mark the device as frozen to make sure the URB + * completion handler won't try to cancel the queue when we kill the URBs. + */ +int uvc_video_suspend(struct uvc_streaming *stream) +{ + if (!uvc_queue_streaming(&stream->queue)) + return 0; + + stream->frozen = 1; + uvc_video_stop_transfer(stream, 0); + usb_set_interface(stream->dev->udev, stream->intfnum, 0); + return 0; +} + +/* + * Reconfigure the video interface and restart streaming if it was enabled + * before suspend. + * + * If an error occurs, disable the video queue. This will wake all pending + * buffers, making sure userspace applications are notified of the problem + * instead of waiting forever. + */ +int uvc_video_resume(struct uvc_streaming *stream, int reset) +{ + int ret; + + /* If the bus has been reset on resume, set the alternate setting to 0. + * This should be the default value, but some devices crash or otherwise + * misbehave if they don't receive a SET_INTERFACE request before any + * other video control request. + */ + if (reset) + usb_set_interface(stream->dev->udev, stream->intfnum, 0); + + stream->frozen = 0; + + uvc_video_clock_reset(stream); + + if (!uvc_queue_streaming(&stream->queue)) + return 0; + + ret = uvc_commit_video(stream, &stream->ctrl); + if (ret < 0) + return ret; + + return uvc_video_start_transfer(stream, GFP_NOIO); +} + +/* ------------------------------------------------------------------------ + * Video device + */ + +/* + * Initialize the UVC video device by switching to alternate setting 0 and + * retrieve the default format. + * + * Some cameras (namely the Fuji Finepix) set the format and frame + * indexes to zero. The UVC standard doesn't clearly make this a spec + * violation, so try to silently fix the values if possible. + * + * This function is called before registering the device with V4L. + */ +int uvc_video_init(struct uvc_streaming *stream) +{ + struct uvc_streaming_control *probe = &stream->ctrl; + struct uvc_format *format = NULL; + struct uvc_frame *frame = NULL; + struct uvc_urb *uvc_urb; + unsigned int i; + int ret; + + if (stream->nformats == 0) { + uvc_printk(KERN_INFO, "No supported video formats found.\n"); + return -EINVAL; + } + + atomic_set(&stream->active, 0); + + /* Alternate setting 0 should be the default, yet the XBox Live Vision + * Cam (and possibly other devices) crash or otherwise misbehave if + * they don't receive a SET_INTERFACE request before any other video + * control request. + */ + usb_set_interface(stream->dev->udev, stream->intfnum, 0); + + /* Set the streaming probe control with default streaming parameters + * retrieved from the device. Webcams that don't support GET_DEF + * requests on the probe control will just keep their current streaming + * parameters. + */ + if (uvc_get_video_ctrl(stream, probe, 1, UVC_GET_DEF) == 0) + uvc_set_video_ctrl(stream, probe, 1); + + /* Initialize the streaming parameters with the probe control current + * value. This makes sure SET_CUR requests on the streaming commit + * control will always use values retrieved from a successful GET_CUR + * request on the probe control, as required by the UVC specification. + */ + ret = uvc_get_video_ctrl(stream, probe, 1, UVC_GET_CUR); + if (ret < 0) + return ret; + + /* Check if the default format descriptor exists. Use the first + * available format otherwise. + */ + for (i = stream->nformats; i > 0; --i) { + format = &stream->format[i-1]; + if (format->index == probe->bFormatIndex) + break; + } + + if (format->nframes == 0) { + uvc_printk(KERN_INFO, "No frame descriptor found for the " + "default format.\n"); + return -EINVAL; + } + + /* Zero bFrameIndex might be correct. Stream-based formats (including + * MPEG-2 TS and DV) do not support frames but have a dummy frame + * descriptor with bFrameIndex set to zero. If the default frame + * descriptor is not found, use the first available frame. + */ + for (i = format->nframes; i > 0; --i) { + frame = &format->frame[i-1]; + if (frame->bFrameIndex == probe->bFrameIndex) + break; + } + + probe->bFormatIndex = format->index; + probe->bFrameIndex = frame->bFrameIndex; + + stream->def_format = format; + stream->cur_format = format; + stream->cur_frame = frame; + + /* Select the video decoding function */ + if (stream->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) { + if (stream->dev->quirks & UVC_QUIRK_BUILTIN_ISIGHT) + stream->decode = uvc_video_decode_isight; + else if (stream->intf->num_altsetting > 1) + stream->decode = uvc_video_decode_isoc; + else + stream->decode = uvc_video_decode_bulk; + } else { + if (stream->intf->num_altsetting == 1) + stream->decode = uvc_video_encode_bulk; + else { + uvc_printk(KERN_INFO, "Isochronous endpoints are not " + "supported for video output devices.\n"); + return -EINVAL; + } + } + + /* Prepare asynchronous work items. */ + for_each_uvc_urb(uvc_urb, stream) + INIT_WORK(&uvc_urb->work, uvc_video_copy_data_work); + + return 0; +} + +int uvc_video_start_streaming(struct uvc_streaming *stream) +{ + int ret; + + ret = uvc_video_clock_init(stream); + if (ret < 0) + return ret; + + /* Commit the streaming parameters. */ + ret = uvc_commit_video(stream, &stream->ctrl); + if (ret < 0) + goto error_commit; + + ret = uvc_video_start_transfer(stream, GFP_KERNEL); + if (ret < 0) + goto error_video; + + return 0; + +error_video: + usb_set_interface(stream->dev->udev, stream->intfnum, 0); +error_commit: + uvc_video_clock_cleanup(stream); + + return ret; +} + +void uvc_video_stop_streaming(struct uvc_streaming *stream) +{ + uvc_video_stop_transfer(stream, 1); + + if (stream->intf->num_altsetting > 1) { + usb_set_interface(stream->dev->udev, stream->intfnum, 0); + } else { + /* UVC doesn't specify how to inform a bulk-based device + * when the video stream is stopped. Windows sends a + * CLEAR_FEATURE(HALT) request to the video streaming + * bulk endpoint, mimic the same behaviour. + */ + unsigned int epnum = stream->header.bEndpointAddress + & USB_ENDPOINT_NUMBER_MASK; + unsigned int dir = stream->header.bEndpointAddress + & USB_ENDPOINT_DIR_MASK; + unsigned int pipe; + + pipe = usb_sndbulkpipe(stream->dev->udev, epnum) | dir; + usb_clear_halt(stream->dev->udev, pipe); + } + + uvc_video_clock_cleanup(stream); +} |