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path: root/drivers/media/usb/uvc/uvc_video.c
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Diffstat (limited to 'drivers/media/usb/uvc/uvc_video.c')
-rw-r--r--drivers/media/usb/uvc/uvc_video.c1879
1 files changed, 1879 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 000000000000..1c15b4227bdb
--- /dev/null
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -0,0 +1,1879 @@
+/*
+ * uvc_video.c -- USB Video Class driver - Video handling
+ *
+ * Copyright (C) 2005-2010
+ * Laurent Pinchart (laurent.pinchart@ideasonboard.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+
+#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;
+
+ ret = __uvc_query_ctrl(dev, query, unit, intfnum, cs, data, size,
+ UVC_CTRL_CONTROL_TIMEOUT);
+ if (ret != size) {
+ 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);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static void uvc_fixup_video_ctrl(struct uvc_streaming *stream,
+ struct uvc_streaming_control *ctrl)
+{
+ struct uvc_format *format = NULL;
+ struct uvc_frame *frame = NULL;
+ unsigned int i;
+
+ 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;
+
+ 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 int uvc_get_video_ctrl(struct uvc_streaming *stream,
+ struct uvc_streaming_control *ctrl, int probe, __u8 query)
+{
+ __u8 *data;
+ __u16 size;
+ int ret;
+
+ size = stream->dev->uvc_version >= 0x0110 ? 34 : 26;
+ 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)
+{
+ __u8 *data;
+ __u16 size;
+ int ret;
+
+ size = stream->dev->uvc_version >= 0x0110 ? 34 : 26;
+ 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 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;
+ struct timespec ts;
+ 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);
+ ktime_get_ts(&ts);
+
+ /* 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_ts = ts;
+
+ /* 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(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 loosing precision in the division. Similarly, the host timestamp is
+ * computed with
+ *
+ * TS = ((TS2 - TS1) * PTS + 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 v4l2_buffer *v4l2_buf,
+ struct uvc_buffer *buf)
+{
+ struct uvc_clock *clock = &stream->clock;
+ struct uvc_clock_sample *first;
+ struct uvc_clock_sample *last;
+ unsigned long flags;
+ struct timespec ts;
+ u32 delta_stc;
+ u32 y1, y2;
+ u32 x1, x2;
+ u32 mean;
+ u32 sof;
+ u32 div;
+ u32 rem;
+ u64 y;
+
+ 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;
+
+ ts = timespec_sub(last->host_ts, first->host_ts);
+ y1 = NSEC_PER_SEC;
+ y2 = (ts.tv_sec + 1) * NSEC_PER_SEC + ts.tv_nsec;
+
+ /* 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);
+
+ div = div_u64_rem(y, NSEC_PER_SEC, &rem);
+ ts.tv_sec = first->host_ts.tv_sec - 1 + div;
+ ts.tv_nsec = first->host_ts.tv_nsec + rem;
+ if (ts.tv_nsec >= NSEC_PER_SEC) {
+ ts.tv_sec++;
+ ts.tv_nsec -= NSEC_PER_SEC;
+ }
+
+ uvc_trace(UVC_TRACE_CLOCK, "%s: SOF %u.%06llu y %llu ts %lu.%06lu "
+ "buf ts %lu.%06lu (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, ts.tv_sec, ts.tv_nsec / NSEC_PER_USEC,
+ v4l2_buf->timestamp.tv_sec, v4l2_buf->timestamp.tv_usec,
+ x1, first->host_sof, first->dev_sof,
+ x2, last->host_sof, last->dev_sof, y1, y2);
+
+ /* Update the V4L2 buffer. */
+ v4l2_buf->timestamp.tv_sec = ts.tv_sec;
+ v4l2_buf->timestamp.tv_usec = ts.tv_nsec / NSEC_PER_USEC;
+
+done:
+ spin_unlock_irqrestore(&stream->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 uninitialized_var(scr_sof);
+ u32 uninitialized_var(scr_stc);
+ u32 uninitialized_var(pts);
+
+ if (stream->stats.stream.nb_frames == 0 &&
+ stream->stats.frame.nb_packets == 0)
+ ktime_get_ts(&stream->stats.stream.start_ts);
+
+ 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;
+ struct timespec ts;
+ size_t count = 0;
+
+ ts.tv_sec = stream->stats.stream.stop_ts.tv_sec
+ - stream->stats.stream.start_ts.tv_sec;
+ ts.tv_nsec = stream->stats.stream.stop_ts.tv_nsec
+ - stream->stats.stream.start_ts.tv_nsec;
+ if (ts.tv_nsec < 0) {
+ ts.tv_sec--;
+ ts.tv_nsec += 1000000000;
+ }
+
+ /* Compute the SCR.SOF frequency estimate. At the nominal 1kHz SOF
+ * frequency this will not overflow before more than 1h.
+ */
+ duration = ts.tv_sec * 1000 + ts.tv_nsec / 1000000;
+ 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)
+{
+ ktime_get_ts(&stream->stats.stream.stop_ts);
+}
+
+/* ------------------------------------------------------------------------
+ * 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) {
+ struct timespec ts;
+
+ 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;
+ }
+
+ if (uvc_clock_param == CLOCK_MONOTONIC)
+ ktime_get_ts(&ts);
+ else
+ ktime_get_real_ts(&ts);
+
+ buf->buf.v4l2_buf.sequence = stream->sequence;
+ buf->buf.v4l2_buf.timestamp.tv_sec = ts.tv_sec;
+ buf->buf.v4l2_buf.timestamp.tv_usec =
+ ts.tv_nsec / NSEC_PER_USEC;
+
+ /* 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];
+}
+
+static void uvc_video_decode_data(struct uvc_streaming *stream,
+ struct uvc_buffer *buf, const __u8 *data, int len)
+{
+ unsigned int maxlen, nbytes;
+ void *mem;
+
+ if (len <= 0)
+ return;
+
+ /* Copy the video data to the buffer. */
+ maxlen = buf->length - buf->bytesused;
+ mem = buf->mem + buf->bytesused;
+ nbytes = min((unsigned int)len, maxlen);
+ memcpy(mem, data, nbytes);
+ buf->bytesused += nbytes;
+
+ /* Complete the current frame if the buffer size was exceeded. */
+ if (len > maxlen) {
+ uvc_trace(UVC_TRACE_FRAME, "Frame complete (overflow).\n");
+ buf->state = UVC_BUF_STATE_READY;
+ }
+}
+
+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;
+}
+
+/* ------------------------------------------------------------------------
+ * URB handling
+ */
+
+/*
+ * Completion handler for video URBs.
+ */
+static void uvc_video_decode_isoc(struct urb *urb, struct uvc_streaming *stream,
+ struct uvc_buffer *buf)
+{
+ 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)
+ buf = uvc_queue_next_buffer(&stream->queue,
+ buf);
+ } while (ret == -EAGAIN);
+
+ if (ret < 0)
+ continue;
+
+ /* Decode the payload data. */
+ uvc_video_decode_data(stream, 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) {
+ if (buf->length != buf->bytesused &&
+ !(stream->cur_format->flags &
+ UVC_FMT_FLAG_COMPRESSED))
+ buf->error = 1;
+
+ buf = uvc_queue_next_buffer(&stream->queue, buf);
+ }
+ }
+}
+
+static void uvc_video_decode_bulk(struct urb *urb, struct uvc_streaming *stream,
+ struct uvc_buffer *buf)
+{
+ 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)
+ buf = uvc_queue_next_buffer(&stream->queue,
+ 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;
+
+ 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.
+ */
+
+ /* Process video data. */
+ if (!stream->bulk.skip_payload && buf != NULL)
+ uvc_video_decode_data(stream, 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)
+ buf = uvc_queue_next_buffer(&stream->queue,
+ buf);
+ }
+
+ stream->bulk.header_size = 0;
+ stream->bulk.skip_payload = 0;
+ stream->bulk.payload_size = 0;
+ }
+}
+
+static void uvc_video_encode_bulk(struct urb *urb, struct uvc_streaming *stream,
+ struct uvc_buffer *buf)
+{
+ 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.v4l2_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_streaming *stream = urb->context;
+ struct uvc_video_queue *queue = &stream->queue;
+ struct uvc_buffer *buf = 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);
+
+ case -ENOENT: /* usb_kill_urb() called. */
+ if (stream->frozen)
+ return;
+
+ case -ECONNRESET: /* usb_unlink_urb() called. */
+ case -ESHUTDOWN: /* The endpoint is being disabled. */
+ uvc_queue_cancel(queue, urb->status == -ESHUTDOWN);
+ return;
+ }
+
+ spin_lock_irqsave(&queue->irqlock, flags);
+ if (!list_empty(&queue->irqqueue))
+ buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
+ queue);
+ spin_unlock_irqrestore(&queue->irqlock, flags);
+
+ stream->decode(urb, stream, buf);
+
+ if ((ret = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
+ uvc_printk(KERN_ERR, "Failed to resubmit video URB (%d).\n",
+ ret);
+ }
+}
+
+/*
+ * Free transfer buffers.
+ */
+static void uvc_free_urb_buffers(struct uvc_streaming *stream)
+{
+ unsigned int i;
+
+ for (i = 0; i < UVC_URBS; ++i) {
+ if (stream->urb_buffer[i]) {
+#ifndef CONFIG_DMA_NONCOHERENT
+ usb_free_coherent(stream->dev->udev, stream->urb_size,
+ stream->urb_buffer[i], stream->urb_dma[i]);
+#else
+ kfree(stream->urb_buffer[i]);
+#endif
+ stream->urb_buffer[i] = 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) {
+ stream->urb_size = psize * npackets;
+#ifndef CONFIG_DMA_NONCOHERENT
+ stream->urb_buffer[i] = usb_alloc_coherent(
+ stream->dev->udev, stream->urb_size,
+ gfp_flags | __GFP_NOWARN, &stream->urb_dma[i]);
+#else
+ stream->urb_buffer[i] =
+ kmalloc(stream->urb_size, gfp_flags | __GFP_NOWARN);
+#endif
+ if (!stream->urb_buffer[i]) {
+ uvc_free_urb_buffers(stream);
+ break;
+ }
+ }
+
+ 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_uninit_video(struct uvc_streaming *stream, int free_buffers)
+{
+ struct urb *urb;
+ unsigned int i;
+
+ uvc_video_stats_stop(stream);
+
+ for (i = 0; i < UVC_URBS; ++i) {
+ urb = stream->urb[i];
+ if (urb == NULL)
+ continue;
+
+ usb_kill_urb(urb);
+ usb_free_urb(urb);
+ stream->urb[i] = 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;
+
+ switch (dev->speed) {
+ case USB_SPEED_SUPER:
+ return ep->ss_ep_comp.wBytesPerInterval;
+ case USB_SPEED_HIGH:
+ psize = usb_endpoint_maxp(&ep->desc);
+ return (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
+ default:
+ psize = usb_endpoint_maxp(&ep->desc);
+ return psize & 0x07ff;
+ }
+}
+
+/*
+ * 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;
+ unsigned int npackets, i, j;
+ 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 (i = 0; i < UVC_URBS; ++i) {
+ urb = usb_alloc_urb(npackets, gfp_flags);
+ if (urb == NULL) {
+ uvc_uninit_video(stream, 1);
+ return -ENOMEM;
+ }
+
+ urb->dev = stream->dev->udev;
+ urb->context = stream;
+ 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 = stream->urb_dma[i];
+#else
+ urb->transfer_flags = URB_ISO_ASAP;
+#endif
+ urb->interval = ep->desc.bInterval;
+ urb->transfer_buffer = stream->urb_buffer[i];
+ urb->complete = uvc_video_complete;
+ urb->number_of_packets = npackets;
+ urb->transfer_buffer_length = size;
+
+ for (j = 0; j < npackets; ++j) {
+ urb->iso_frame_desc[j].offset = j * psize;
+ urb->iso_frame_desc[j].length = psize;
+ }
+
+ stream->urb[i] = 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;
+ unsigned int npackets, pipe, i;
+ u16 psize;
+ u32 size;
+
+ psize = usb_endpoint_maxp(&ep->desc) & 0x7ff;
+ 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 (i = 0; i < UVC_URBS; ++i) {
+ urb = usb_alloc_urb(0, gfp_flags);
+ if (urb == NULL) {
+ uvc_uninit_video(stream, 1);
+ return -ENOMEM;
+ }
+
+ usb_fill_bulk_urb(urb, stream->dev->udev, pipe,
+ stream->urb_buffer[i], size, uvc_video_complete,
+ stream);
+#ifndef CONFIG_DMA_NONCOHERENT
+ urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
+ urb->transfer_dma = stream->urb_dma[i];
+#endif
+
+ stream->urb[i] = urb;
+ }
+
+ return 0;
+}
+
+/*
+ * Initialize isochronous/bulk URBs and allocate transfer buffers.
+ */
+static int uvc_init_video(struct uvc_streaming *stream, gfp_t gfp_flags)
+{
+ struct usb_interface *intf = stream->intf;
+ struct usb_host_endpoint *ep;
+ 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 uninitialized_var(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);
+
+ 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;
+
+ ret = uvc_init_video_bulk(stream, ep, gfp_flags);
+ }
+
+ if (ret < 0)
+ return ret;
+
+ /* Submit the URBs. */
+ for (i = 0; i < UVC_URBS; ++i) {
+ ret = usb_submit_urb(stream->urb[i], gfp_flags);
+ if (ret < 0) {
+ uvc_printk(KERN_ERR, "Failed to submit URB %u "
+ "(%d).\n", i, ret);
+ uvc_uninit_video(stream, 1);
+ return ret;
+ }
+ }
+
+ 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_uninit_video(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);
+
+ ret = uvc_commit_video(stream, &stream->ctrl);
+ if (ret < 0) {
+ uvc_queue_enable(&stream->queue, 0);
+ return ret;
+ }
+
+ if (!uvc_queue_streaming(&stream->queue))
+ return 0;
+
+ ret = uvc_init_video(stream, GFP_NOIO);
+ if (ret < 0)
+ uvc_queue_enable(&stream->queue, 0);
+
+ return ret;
+}
+
+/* ------------------------------------------------------------------------
+ * 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;
+ 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);
+
+ /* Initialize the video buffers queue. */
+ uvc_queue_init(&stream->queue, stream->type, !uvc_no_drop_param);
+
+ /* 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 suport 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->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;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Enable or disable the video stream.
+ */
+int uvc_video_enable(struct uvc_streaming *stream, int enable)
+{
+ int ret;
+
+ if (!enable) {
+ uvc_uninit_video(stream, 1);
+ usb_set_interface(stream->dev->udev, stream->intfnum, 0);
+ uvc_queue_enable(&stream->queue, 0);
+ uvc_video_clock_cleanup(stream);
+ return 0;
+ }
+
+ ret = uvc_video_clock_init(stream);
+ if (ret < 0)
+ return ret;
+
+ ret = uvc_queue_enable(&stream->queue, 1);
+ if (ret < 0)
+ goto error_queue;
+
+ /* Commit the streaming parameters. */
+ ret = uvc_commit_video(stream, &stream->ctrl);
+ if (ret < 0)
+ goto error_commit;
+
+ ret = uvc_init_video(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_queue_enable(&stream->queue, 0);
+error_queue:
+ uvc_video_clock_cleanup(stream);
+
+ return ret;
+}