LinuxTV Patchwork [3/3] uvcvideo: add a metadata device node

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Submitter Guennadi Liakhovetski
Date June 24, 2016, 11:29 a.m.
Message ID <Pine.LNX.4.64.1606241327550.23461@axis700.grange>
Download mbox | patch
Permalink /patch/34787/
State New
Delegated to: Laurent Pinchart
Headers show

Comments

Guennadi Liakhovetski - June 24, 2016, 11:29 a.m.
Some UVC video cameras contain metadata in their payload headers. This
patch extracts that data, skipping the standard part of the header, on
both bulk and isochronous endpoints and makes it available to the user
space on a separate video node, using the V4L2_CAP_META_CAPTURE
capability and the V4L2_BUF_TYPE_META_CAPTURE buffer queue type. Even
though different cameras will have different metadata formats, we use
the same V4L2_META_FMT_UVC pixel format for all of them. Users have to
parse data, based on the specific camera model information.

Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@intel.com>
---
 drivers/media/usb/uvc/Makefile       |   2 +-
 drivers/media/usb/uvc/uvc_driver.c   |  10 ++
 drivers/media/usb/uvc/uvc_isight.c   |   2 +-
 drivers/media/usb/uvc/uvc_metadata.c | 234 +++++++++++++++++++++++++++++++++++
 drivers/media/usb/uvc/uvc_v4l2.c     |   2 +-
 drivers/media/usb/uvc/uvc_video.c    |  59 +++++++--
 drivers/media/usb/uvc/uvcvideo.h     |  12 +-
 7 files changed, 309 insertions(+), 12 deletions(-)
 create mode 100644 drivers/media/usb/uvc/uvc_metadata.c
kbuild test robot - June 24, 2016, 12:46 p.m.
Hi,

[auto build test ERROR on linuxtv-media/master]
[also build test ERROR on v4.7-rc4 next-20160624]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Guennadi-Liakhovetski/uvcvideo-a-cosmetic-fix-and-2-new-features/20160624-193142
base:   git://linuxtv.org/media_tree.git master
config: x86_64-rhel (attached as .config)
compiler: gcc-4.9 (Debian 4.9.3-14) 4.9.3
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All error/warnings (new ones prefixed by >>):

   drivers/media/usb/uvc/uvc_v4l2.c: In function 'uvc_ioctl_querycap':
>> drivers/media/usb/uvc/uvc_v4l2.c:575:8: error: 'V4L2_CAP_META_CAPTURE' undeclared (first use in this function)
         | V4L2_CAP_META_CAPTURE | chain->caps;
           ^
   drivers/media/usb/uvc/uvc_v4l2.c:575:8: note: each undeclared identifier is reported only once for each function it appears in
--
   drivers/media/usb/uvc/uvc_metadata.c: In function 'meta_v4l2_querycap':
>> drivers/media/usb/uvc/uvc_metadata.c:133:21: error: 'V4L2_CAP_META_CAPTURE' undeclared (first use in this function)
     cap->device_caps = V4L2_CAP_META_CAPTURE
                        ^
   drivers/media/usb/uvc/uvc_metadata.c:133:21: note: each undeclared identifier is reported only once for each function it appears in
   drivers/media/usb/uvc/uvc_metadata.c: In function 'meta_v4l2_get_format':
>> drivers/media/usb/uvc/uvc_metadata.c:149:45: error: 'union <anonymous>' has no member named 'meta'
     struct v4l2_meta_format *fmt = &format->fmt.meta;
                                                ^
>> drivers/media/usb/uvc/uvc_metadata.c:154:24: error: dereferencing pointer to incomplete type
     memset(fmt, 0, sizeof(*fmt));
                           ^
   drivers/media/usb/uvc/uvc_metadata.c:156:5: error: dereferencing pointer to incomplete type
     fmt->dataformat = V4L2_META_FMT_UVC;
        ^
>> drivers/media/usb/uvc/uvc_metadata.c:156:20: error: 'V4L2_META_FMT_UVC' undeclared (first use in this function)
     fmt->dataformat = V4L2_META_FMT_UVC;
                       ^
   drivers/media/usb/uvc/uvc_metadata.c:157:5: error: dereferencing pointer to incomplete type
     fmt->buffersize = UVC_PAYLOAD_HEADER_MAX_SIZE;
        ^
   drivers/media/usb/uvc/uvc_metadata.c: At top level:
>> drivers/media/usb/uvc/uvc_metadata.c:164:2: error: unknown field 'vidioc_g_fmt_meta_cap' specified in initializer
     .vidioc_g_fmt_meta_cap  = meta_v4l2_get_format,
     ^
>> drivers/media/usb/uvc/uvc_metadata.c:164:2: warning: initialization from incompatible pointer type
   drivers/media/usb/uvc/uvc_metadata.c:164:2: warning: (near initialization for 'uvc_meta_ioctl_ops.vidioc_enum_fmt_vid_cap')
>> drivers/media/usb/uvc/uvc_metadata.c:165:2: error: unknown field 'vidioc_s_fmt_meta_cap' specified in initializer
     .vidioc_s_fmt_meta_cap  = meta_v4l2_get_format,
     ^
   drivers/media/usb/uvc/uvc_metadata.c:165:2: warning: initialization from incompatible pointer type
   drivers/media/usb/uvc/uvc_metadata.c:165:2: warning: (near initialization for 'uvc_meta_ioctl_ops.vidioc_enum_fmt_vid_overlay')
>> drivers/media/usb/uvc/uvc_metadata.c:166:2: error: unknown field 'vidioc_try_fmt_meta_cap' specified in initializer
     .vidioc_try_fmt_meta_cap = meta_v4l2_get_format,
     ^
   drivers/media/usb/uvc/uvc_metadata.c:166:2: warning: initialization from incompatible pointer type
   drivers/media/usb/uvc/uvc_metadata.c:166:2: warning: (near initialization for 'uvc_meta_ioctl_ops.vidioc_enum_fmt_vid_out')
   drivers/media/usb/uvc/uvc_metadata.c: In function 'uvc_meta_register':
>> drivers/media/usb/uvc/uvc_metadata.c:210:16: error: 'V4L2_BUF_TYPE_META_CAPTURE' undeclared (first use in this function)
     queue->type = V4L2_BUF_TYPE_META_CAPTURE;
                   ^

vim +/V4L2_CAP_META_CAPTURE +575 drivers/media/usb/uvc/uvc_v4l2.c

   569		struct uvc_streaming *stream = handle->stream;
   570	
   571		strlcpy(cap->driver, "uvcvideo", sizeof(cap->driver));
   572		strlcpy(cap->card, vdev->name, sizeof(cap->card));
   573		usb_make_path(stream->dev->udev, cap->bus_info, sizeof(cap->bus_info));
   574		cap->capabilities = V4L2_CAP_DEVICE_CAPS | V4L2_CAP_STREAMING
 > 575				  | V4L2_CAP_META_CAPTURE | chain->caps;
   576		if (stream->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
   577			cap->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
   578		else

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
kbuild test robot - June 24, 2016, 1:12 p.m.
Hi,

[auto build test ERROR on linuxtv-media/master]
[also build test ERROR on v4.7-rc4 next-20160624]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Guennadi-Liakhovetski/uvcvideo-a-cosmetic-fix-and-2-new-features/20160624-193142
base:   git://linuxtv.org/media_tree.git master
config: arm-exynos_defconfig (attached as .config)
compiler: arm-linux-gnueabi-gcc (Debian 5.3.1-8) 5.3.1 20160205
reproduce:
        wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        make.cross ARCH=arm 

All errors (new ones prefixed by >>):

   drivers/media/usb/uvc/uvc_metadata.c: In function 'meta_v4l2_querycap':
   drivers/media/usb/uvc/uvc_metadata.c:133:21: error: 'V4L2_CAP_META_CAPTURE' undeclared (first use in this function)
     cap->device_caps = V4L2_CAP_META_CAPTURE
                        ^
   drivers/media/usb/uvc/uvc_metadata.c:133:21: note: each undeclared identifier is reported only once for each function it appears in
   drivers/media/usb/uvc/uvc_metadata.c: In function 'meta_v4l2_get_format':
   drivers/media/usb/uvc/uvc_metadata.c:149:45: error: 'union <anonymous>' has no member named 'meta'
     struct v4l2_meta_format *fmt = &format->fmt.meta;
                                                ^
   In file included from include/linux/string.h:18:0,
                    from include/linux/dynamic_debug.h:111,
                    from include/linux/printk.h:289,
                    from include/linux/kernel.h:13,
                    from drivers/media/usb/uvc/uvc_metadata.c:13:
>> drivers/media/usb/uvc/uvc_metadata.c:154:24: error: dereferencing pointer to incomplete type 'struct v4l2_meta_format'
     memset(fmt, 0, sizeof(*fmt));
                           ^
   arch/arm/include/asm/string.h:31:34: note: in definition of macro 'memset'
       void *__p = (p); size_t __n = n;   \
                                     ^
   drivers/media/usb/uvc/uvc_metadata.c:156:20: error: 'V4L2_META_FMT_UVC' undeclared (first use in this function)
     fmt->dataformat = V4L2_META_FMT_UVC;
                       ^
   drivers/media/usb/uvc/uvc_metadata.c: At top level:
   drivers/media/usb/uvc/uvc_metadata.c:164:2: error: unknown field 'vidioc_g_fmt_meta_cap' specified in initializer
     .vidioc_g_fmt_meta_cap  = meta_v4l2_get_format,
     ^
>> drivers/media/usb/uvc/uvc_metadata.c:164:28: error: initialization from incompatible pointer type [-Werror=incompatible-pointer-types]
     .vidioc_g_fmt_meta_cap  = meta_v4l2_get_format,
                               ^
   drivers/media/usb/uvc/uvc_metadata.c:164:28: note: (near initialization for 'uvc_meta_ioctl_ops.vidioc_enum_fmt_vid_cap')
   drivers/media/usb/uvc/uvc_metadata.c:165:2: error: unknown field 'vidioc_s_fmt_meta_cap' specified in initializer
     .vidioc_s_fmt_meta_cap  = meta_v4l2_get_format,
     ^
   drivers/media/usb/uvc/uvc_metadata.c:165:28: error: initialization from incompatible pointer type [-Werror=incompatible-pointer-types]
     .vidioc_s_fmt_meta_cap  = meta_v4l2_get_format,
                               ^
   drivers/media/usb/uvc/uvc_metadata.c:165:28: note: (near initialization for 'uvc_meta_ioctl_ops.vidioc_enum_fmt_vid_overlay')
   drivers/media/usb/uvc/uvc_metadata.c:166:2: error: unknown field 'vidioc_try_fmt_meta_cap' specified in initializer
     .vidioc_try_fmt_meta_cap = meta_v4l2_get_format,
     ^
   drivers/media/usb/uvc/uvc_metadata.c:166:29: error: initialization from incompatible pointer type [-Werror=incompatible-pointer-types]
     .vidioc_try_fmt_meta_cap = meta_v4l2_get_format,
                                ^
   drivers/media/usb/uvc/uvc_metadata.c:166:29: note: (near initialization for 'uvc_meta_ioctl_ops.vidioc_enum_fmt_vid_out')
   drivers/media/usb/uvc/uvc_metadata.c: In function 'uvc_meta_register':
   drivers/media/usb/uvc/uvc_metadata.c:210:16: error: 'V4L2_BUF_TYPE_META_CAPTURE' undeclared (first use in this function)
     queue->type = V4L2_BUF_TYPE_META_CAPTURE;
                   ^
   cc1: some warnings being treated as errors

vim +154 drivers/media/usb/uvc/uvc_metadata.c

   143	}
   144	
   145	static int meta_v4l2_get_format(struct file *file, void *fh,
   146					struct v4l2_format *format)
   147	{
   148		struct v4l2_fh *vfh = file->private_data;
 > 149		struct v4l2_meta_format *fmt = &format->fmt.meta;
   150	
   151		if (format->type != vfh->vdev->queue->type)
   152			return -EINVAL;
   153	
 > 154		memset(fmt, 0, sizeof(*fmt));
   155	
 > 156		fmt->dataformat = V4L2_META_FMT_UVC;
   157		fmt->buffersize = UVC_PAYLOAD_HEADER_MAX_SIZE;
   158	
   159		return 0;
   160	}
   161	
   162	static const struct v4l2_ioctl_ops uvc_meta_ioctl_ops = {
   163		.vidioc_querycap		= meta_v4l2_querycap,
 > 164		.vidioc_g_fmt_meta_cap		= meta_v4l2_get_format,
   165		.vidioc_s_fmt_meta_cap		= meta_v4l2_get_format,
   166		.vidioc_try_fmt_meta_cap	= meta_v4l2_get_format,
   167		.vidioc_reqbufs			= vb2_ioctl_reqbufs,

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

Patch

diff --git a/drivers/media/usb/uvc/Makefile b/drivers/media/usb/uvc/Makefile
index c26d12f..06c7cd3 100644
--- a/drivers/media/usb/uvc/Makefile
+++ b/drivers/media/usb/uvc/Makefile
@@ -1,5 +1,5 @@ 
 uvcvideo-objs  := uvc_driver.o uvc_queue.o uvc_v4l2.o uvc_video.o uvc_ctrl.o \
-		  uvc_status.o uvc_isight.o uvc_debugfs.o
+		  uvc_status.o uvc_isight.o uvc_debugfs.o uvc_metadata.o
 ifeq ($(CONFIG_MEDIA_CONTROLLER),y)
 uvcvideo-objs  += uvc_entity.o
 endif
diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
index 302e284..1a75ff0 100644
--- a/drivers/media/usb/uvc/uvc_driver.c
+++ b/drivers/media/usb/uvc/uvc_driver.c
@@ -1740,6 +1740,9 @@  static void uvc_unregister_video(struct uvc_device *dev)
 
 		video_unregister_device(&stream->vdev);
 
+		if (video_is_registered(&stream->meta.vdev))
+			video_unregister_device(&stream->meta.vdev);
+
 		uvc_debugfs_cleanup_stream(stream);
 	}
 
@@ -1800,6 +1803,13 @@  static int uvc_register_video(struct uvc_device *dev,
 		return ret;
 	}
 
+	/*
+	 * Register a metadata node. TODO: shall this only be enabled for some
+	 * cameras?
+	 */
+	if (!(dev->quirks & UVC_QUIRK_BUILTIN_ISIGHT))
+		uvc_meta_register(stream);
+
 	if (stream->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
 		stream->chain->caps |= V4L2_CAP_VIDEO_CAPTURE;
 	else
diff --git a/drivers/media/usb/uvc/uvc_isight.c b/drivers/media/usb/uvc/uvc_isight.c
index 8510e725..fb940cf 100644
--- a/drivers/media/usb/uvc/uvc_isight.c
+++ b/drivers/media/usb/uvc/uvc_isight.c
@@ -100,7 +100,7 @@  static int isight_decode(struct uvc_video_queue *queue, struct uvc_buffer *buf,
 }
 
 void uvc_video_decode_isight(struct urb *urb, struct uvc_streaming *stream,
-		struct uvc_buffer *buf)
+			struct uvc_buffer *buf, struct uvc_buffer *meta_buf)
 {
 	int ret, i;
 
diff --git a/drivers/media/usb/uvc/uvc_metadata.c b/drivers/media/usb/uvc/uvc_metadata.c
new file mode 100644
index 0000000..54f326c
--- /dev/null
+++ b/drivers/media/usb/uvc/uvc_metadata.c
@@ -0,0 +1,234 @@ 
+/*
+ *      uvc_metadata.c  --  USB Video Class driver - Metadata handling
+ *
+ *      Copyright (C) 2016
+ *          Guennadi Liakhovetski (guennadi.liakhovetski@intel.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/usb.h>
+#include <linux/videodev2.h>
+
+#include <media/v4l2-ioctl.h>
+#include <media/videobuf2-v4l2.h>
+#include <media/videobuf2-vmalloc.h>
+
+#include "uvcvideo.h"
+
+static inline struct uvc_buffer *to_uvc_buffer(struct vb2_v4l2_buffer *vbuf)
+{
+	return container_of(vbuf, struct uvc_buffer, buf);
+}
+
+/* -----------------------------------------------------------------------------
+ * videobuf2 Queue Operations
+ */
+
+/*
+ * Actually 253 bytes, but 256 is just a nicer number. We keep the buffer size
+ * constant and just set .usedbytes accordingly
+ */
+#define UVC_PAYLOAD_HEADER_MAX_SIZE 256
+
+static int meta_queue_setup(struct vb2_queue *vq, unsigned int *nbuffers,
+			    unsigned int *nplanes, unsigned int sizes[],
+			    void *alloc_ctxs[])
+{
+	if (*nplanes) {
+		if (*nplanes != 1)
+			return -EINVAL;
+
+		if (sizes[0] < UVC_PAYLOAD_HEADER_MAX_SIZE)
+			return -EINVAL;
+
+		return 0;
+	}
+
+	*nplanes = 1;
+	sizes[0] = UVC_PAYLOAD_HEADER_MAX_SIZE;
+
+	return 0;
+}
+
+static int meta_buffer_prepare(struct vb2_buffer *vb)
+{
+	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+	struct uvc_buffer *buf = to_uvc_buffer(vbuf);
+
+	if (vb->num_planes != 1)
+		return -EINVAL;
+
+	if (vb2_plane_size(vb, 0) < UVC_PAYLOAD_HEADER_MAX_SIZE)
+		return -EINVAL;
+
+	buf->state = UVC_BUF_STATE_QUEUED;
+	buf->error = 0;
+	buf->mem = vb2_plane_vaddr(vb, 0);
+	buf->length = vb2_plane_size(vb, 0);
+	buf->bytesused = 0;
+
+	return 0;
+}
+
+static void meta_buffer_queue(struct vb2_buffer *vb)
+{
+	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+	struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
+	struct uvc_buffer *buf = to_uvc_buffer(vbuf);
+	unsigned long flags;
+
+	spin_lock_irqsave(&queue->irqlock, flags);
+	list_add_tail(&buf->queue, &queue->irqqueue);
+	spin_unlock_irqrestore(&queue->irqlock, flags);
+}
+
+static int meta_start_streaming(struct vb2_queue *vq, unsigned int count)
+{
+	return 0;
+}
+
+static void meta_stop_streaming(struct vb2_queue *vq)
+{
+	struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
+	struct uvc_buffer *buffer;
+	unsigned long flags;
+
+	spin_lock_irqsave(&queue->irqlock, flags);
+
+	/* Remove all buffers from the IRQ queue. */
+	list_for_each_entry(buffer, &queue->irqqueue, queue)
+		vb2_buffer_done(&buffer->buf.vb2_buf, VB2_BUF_STATE_ERROR);
+	INIT_LIST_HEAD(&queue->irqqueue);
+
+	spin_unlock_irqrestore(&queue->irqlock, flags);
+}
+
+static struct vb2_ops uvc_meta_queue_ops = {
+	.queue_setup = meta_queue_setup,
+	.buf_prepare = meta_buffer_prepare,
+	.buf_queue = meta_buffer_queue,
+	.wait_prepare = vb2_ops_wait_prepare,
+	.wait_finish = vb2_ops_wait_finish,
+	.start_streaming = meta_start_streaming,
+	.stop_streaming = meta_stop_streaming,
+};
+
+/* -----------------------------------------------------------------------------
+ * V4L2 ioctls
+ */
+
+static int meta_v4l2_querycap(struct file *file, void *fh,
+			      struct v4l2_capability *cap)
+{
+	struct v4l2_fh *vfh = file->private_data;
+	struct uvc_streaming *stream = video_get_drvdata(vfh->vdev);
+
+	cap->device_caps = V4L2_CAP_META_CAPTURE
+			 | V4L2_CAP_STREAMING;
+	cap->capabilities = V4L2_CAP_DEVICE_CAPS | cap->device_caps
+			  | stream->chain->caps;
+
+	strlcpy(cap->driver, "uvcvideo", sizeof(cap->driver));
+	strlcpy(cap->card, vfh->vdev->name, sizeof(cap->card));
+	usb_make_path(stream->dev->udev, cap->bus_info, sizeof(cap->bus_info));
+
+	return 0;
+}
+
+static int meta_v4l2_get_format(struct file *file, void *fh,
+				struct v4l2_format *format)
+{
+	struct v4l2_fh *vfh = file->private_data;
+	struct v4l2_meta_format *fmt = &format->fmt.meta;
+
+	if (format->type != vfh->vdev->queue->type)
+		return -EINVAL;
+
+	memset(fmt, 0, sizeof(*fmt));
+
+	fmt->dataformat = V4L2_META_FMT_UVC;
+	fmt->buffersize = UVC_PAYLOAD_HEADER_MAX_SIZE;
+
+	return 0;
+}
+
+static const struct v4l2_ioctl_ops uvc_meta_ioctl_ops = {
+	.vidioc_querycap		= meta_v4l2_querycap,
+	.vidioc_g_fmt_meta_cap		= meta_v4l2_get_format,
+	.vidioc_s_fmt_meta_cap		= meta_v4l2_get_format,
+	.vidioc_try_fmt_meta_cap	= meta_v4l2_get_format,
+	.vidioc_reqbufs			= vb2_ioctl_reqbufs,
+	.vidioc_querybuf		= vb2_ioctl_querybuf,
+	.vidioc_qbuf			= vb2_ioctl_qbuf,
+	.vidioc_dqbuf			= vb2_ioctl_dqbuf,
+	.vidioc_create_bufs		= vb2_ioctl_create_bufs,
+	.vidioc_prepare_buf		= vb2_ioctl_prepare_buf,
+	.vidioc_streamon		= vb2_ioctl_streamon,
+	.vidioc_streamoff		= vb2_ioctl_streamoff,
+};
+
+/* -----------------------------------------------------------------------------
+ * V4L2 File Operations
+ */
+
+static struct v4l2_file_operations uvc_meta_fops = {
+	.owner = THIS_MODULE,
+	.unlocked_ioctl = video_ioctl2,
+	.open = v4l2_fh_open,
+	.release = vb2_fop_release,
+	.poll = vb2_fop_poll,
+	.mmap = vb2_fop_mmap,
+};
+
+int uvc_meta_register(struct uvc_streaming *stream)
+{
+	struct uvc_device *dev = stream->dev;
+	struct uvc_meta_dev *meta = &stream->meta;
+	struct video_device *vdev = &meta->vdev;
+	struct uvc_video_queue *quvc = &meta->queue;
+	struct vb2_queue *queue = &quvc->queue;
+	int ret;
+
+	vdev->v4l2_dev = &dev->vdev;
+	vdev->fops = &uvc_meta_fops;
+	vdev->ioctl_ops = &uvc_meta_ioctl_ops;
+	vdev->release = video_device_release_empty;
+	vdev->prio = &stream->chain->prio;
+	vdev->vfl_dir = VFL_DIR_RX;
+	strlcpy(vdev->name, dev->name, sizeof(vdev->name));
+
+	video_set_drvdata(vdev, stream);
+
+	/* Initialize the video buffer queue. */
+	queue->type = V4L2_BUF_TYPE_META_CAPTURE;
+	queue->io_modes = VB2_MMAP | VB2_USERPTR;
+	queue->drv_priv = quvc;
+	queue->buf_struct_size = sizeof(struct uvc_buffer);
+	queue->ops = &uvc_meta_queue_ops;
+	queue->mem_ops = &vb2_vmalloc_memops;
+	queue->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC
+		| V4L2_BUF_FLAG_TSTAMP_SRC_SOE;
+	queue->lock = &quvc->mutex;
+	ret = vb2_queue_init(queue);
+	if (ret < 0)
+		return ret;
+
+	mutex_init(&quvc->mutex);
+	spin_lock_init(&quvc->irqlock);
+	INIT_LIST_HEAD(&quvc->irqqueue);
+
+	vdev->queue = queue;
+
+	ret = video_register_device(vdev, VFL_TYPE_GRABBER, -1);
+	if (ret < 0)
+		uvc_printk(KERN_ERR, "Failed to register metadata device (%d).\n", ret);
+
+	return ret;
+}
diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index ee295f3..9e6e2fb 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -572,7 +572,7 @@  static int uvc_ioctl_querycap(struct file *file, void *fh,
 	strlcpy(cap->card, vdev->name, sizeof(cap->card));
 	usb_make_path(stream->dev->udev, cap->bus_info, sizeof(cap->bus_info));
 	cap->capabilities = V4L2_CAP_DEVICE_CAPS | V4L2_CAP_STREAMING
-			  | chain->caps;
+			  | V4L2_CAP_META_CAPTURE | chain->caps;
 	if (stream->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
 		cap->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
 	else
diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index 79827dd..52e2d45 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -1202,8 +1202,42 @@  static void uvc_video_validate_buffer(const struct uvc_streaming *stream,
 /*
  * Completion handler for video URBs.
  */
+static void uvc_video_decode_meta(struct uvc_streaming *stream,
+			struct uvc_buffer *buf, struct uvc_buffer *meta_buf,
+			u8 *mem, int length)
+{
+	size_t header_len = 2;
+
+	if (!meta_buf)
+		return;
+
+	if (mem[1] & UVC_STREAM_PTS)
+		/* dwPresentationTime is included */
+		header_len += 4;
+	if (mem[1] & UVC_STREAM_SCR)
+		/* scrSourceClock is included */
+		header_len += 6;
+
+	if (length > header_len) {
+		size_t nbytes = min_t(unsigned int,
+				      length - header_len, meta_buf->length);
+
+		meta_buf->buf.sequence = buf->buf.sequence;
+		meta_buf->buf.field = buf->buf.field;
+		meta_buf->buf.vb2_buf.timestamp =
+			buf->buf.vb2_buf.timestamp;
+
+		memcpy(meta_buf->mem, mem + header_len, nbytes);
+		meta_buf->bytesused = nbytes;
+		meta_buf->state = UVC_BUF_STATE_READY;
+
+		uvc_queue_next_buffer(&stream->meta.queue,
+				      meta_buf);
+	}
+}
+
 static void uvc_video_decode_isoc(struct urb *urb, struct uvc_streaming *stream,
-	struct uvc_buffer *buf)
+			struct uvc_buffer *buf, struct uvc_buffer *meta_buf)
 {
 	u8 *mem;
 	int ret, i;
@@ -1233,6 +1267,8 @@  static void uvc_video_decode_isoc(struct urb *urb, struct uvc_streaming *stream,
 		if (ret < 0)
 			continue;
 
+		uvc_video_decode_meta(stream, buf, meta_buf, mem, ret);
+
 		/* Decode the payload data. */
 		uvc_video_decode_data(stream, buf, mem + ret,
 			urb->iso_frame_desc[i].actual_length - ret);
@@ -1249,7 +1285,7 @@  static void uvc_video_decode_isoc(struct urb *urb, struct uvc_streaming *stream,
 }
 
 static void uvc_video_decode_bulk(struct urb *urb, struct uvc_streaming *stream,
-	struct uvc_buffer *buf)
+			struct uvc_buffer *buf, struct uvc_buffer *meta_buf)
 {
 	u8 *mem;
 	int len, ret;
@@ -1283,6 +1319,8 @@  static void uvc_video_decode_bulk(struct urb *urb, struct uvc_streaming *stream,
 			memcpy(stream->bulk.header, mem, ret);
 			stream->bulk.header_size = ret;
 
+			uvc_video_decode_meta(stream, buf, meta_buf, mem, ret);
+
 			mem += ret;
 			len -= ret;
 		}
@@ -1306,8 +1344,7 @@  static void uvc_video_decode_bulk(struct urb *urb, struct uvc_streaming *stream,
 			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);
+				uvc_queue_next_buffer(&stream->queue, buf);
 		}
 
 		stream->bulk.header_size = 0;
@@ -1317,7 +1354,7 @@  static void uvc_video_decode_bulk(struct urb *urb, struct uvc_streaming *stream,
 }
 
 static void uvc_video_encode_bulk(struct urb *urb, struct uvc_streaming *stream,
-	struct uvc_buffer *buf)
+	struct uvc_buffer *buf, struct uvc_buffer *meta_buf)
 {
 	u8 *mem = urb->transfer_buffer;
 	int len = stream->urb_size, ret;
@@ -1363,7 +1400,8 @@  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;
+	struct uvc_video_queue *qmeta = &stream->meta.queue;
+	struct uvc_buffer *buf = NULL, *buf_meta = NULL;
 	unsigned long flags;
 	int ret;
 
@@ -1382,6 +1420,7 @@  static void uvc_video_complete(struct urb *urb)
 	case -ECONNRESET:	/* usb_unlink_urb() called. */
 	case -ESHUTDOWN:	/* The endpoint is being disabled. */
 		uvc_queue_cancel(queue, urb->status == -ESHUTDOWN);
+		uvc_queue_cancel(qmeta, urb->status == -ESHUTDOWN);
 		return;
 	}
 
@@ -1391,7 +1430,13 @@  static void uvc_video_complete(struct urb *urb)
 				       queue);
 	spin_unlock_irqrestore(&queue->irqlock, flags);
 
-	stream->decode(urb, stream, buf);
+	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);
+
+	stream->decode(urb, stream, buf, buf_meta);
 
 	if ((ret = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
 		uvc_printk(KERN_ERR, "Failed to resubmit video URB (%d).\n",
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index a61c55b..7e2e220 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -455,6 +455,11 @@  struct uvc_stats_stream {
 	unsigned int max_sof;		/* Maximum STC.SOF value */
 };
 
+struct uvc_meta_dev {
+	struct video_device vdev;
+	struct uvc_video_queue queue;
+};
+
 struct uvc_streaming {
 	struct list_head list;
 	struct uvc_device *dev;
@@ -486,7 +491,9 @@  struct uvc_streaming {
 	unsigned int frozen : 1;
 	struct uvc_video_queue queue;
 	void (*decode) (struct urb *urb, struct uvc_streaming *video,
-			struct uvc_buffer *buf);
+			struct uvc_buffer *buf, struct uvc_buffer *meta_buf);
+
+	struct uvc_meta_dev meta;
 
 	/* Context data used by the bulk completion handler. */
 	struct {
@@ -698,6 +705,7 @@  extern int uvc_query_ctrl(struct uvc_device *dev, __u8 query, __u8 unit,
 void uvc_video_clock_update(struct uvc_streaming *stream,
 			    struct vb2_v4l2_buffer *vbuf,
 			    struct uvc_buffer *buf);
+int uvc_meta_register(struct uvc_streaming *stream);
 
 /* Status */
 extern int uvc_status_init(struct uvc_device *dev);
@@ -754,7 +762,7 @@  extern struct usb_host_endpoint *uvc_find_endpoint(
 
 /* Quirks support */
 void uvc_video_decode_isight(struct urb *urb, struct uvc_streaming *stream,
-		struct uvc_buffer *buf);
+		struct uvc_buffer *buf, struct uvc_buffer *meta_buf);
 
 /* debugfs and statistics */
 int uvc_debugfs_init(void);

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