Re: [PATCH v5] vivid: Add metadata capture support

[Hans Verkuil <hverkuil@xs4all.nl>]

On 9/16/19 9:48 AM, Vandana BN wrote:
> This patch adds meatadata capture support in vivid driver.
> Added new files for metadata capture.
> 
> Signed-off-by: Vandana BN <bnvandana@gmail.com>

It's good practice to mention what has changed since v4.

You can do that by adding a --- separator and then something along the lines of:

---

Changes since v4:
- foo
- bar

Everything between the two --- separators is ignored when the patch is merged,
so it won't end up in the commit log.

> ---
>  drivers/media/platform/vivid/Makefile         |   2 +-
>  drivers/media/platform/vivid/vivid-core.c     |  92 ++++++++-
>  drivers/media/platform/vivid/vivid-core.h     |  12 ++
>  drivers/media/platform/vivid/vivid-ctrls.c    |  14 ++
>  .../media/platform/vivid/vivid-kthread-cap.c  |  48 ++++-
>  drivers/media/platform/vivid/vivid-meta-cap.c | 175 ++++++++++++++++++
>  drivers/media/platform/vivid/vivid-meta-cap.h |  18 ++
>  drivers/media/platform/vivid/vivid-meta-gen.c |  25 +++
>  drivers/media/platform/vivid/vivid-meta-gen.h |  18 ++
>  9 files changed, 395 insertions(+), 9 deletions(-)
>  create mode 100644 drivers/media/platform/vivid/vivid-meta-cap.c
>  create mode 100644 drivers/media/platform/vivid/vivid-meta-cap.h
>  create mode 100644 drivers/media/platform/vivid/vivid-meta-gen.c
>  create mode 100644 drivers/media/platform/vivid/vivid-meta-gen.h
> 
> diff --git a/drivers/media/platform/vivid/Makefile b/drivers/media/platform/vivid/Makefile
> index 2f5762e3309a..70a9262fafaa 100644
> --- a/drivers/media/platform/vivid/Makefile
> +++ b/drivers/media/platform/vivid/Makefile
> @@ -3,7 +3,7 @@ vivid-objs := vivid-core.o vivid-ctrls.o vivid-vid-common.o vivid-vbi-gen.o \
>  		vivid-vid-cap.o vivid-vid-out.o vivid-kthread-cap.o vivid-kthread-out.o \
>  		vivid-radio-rx.o vivid-radio-tx.o vivid-radio-common.o \
>  		vivid-rds-gen.o vivid-sdr-cap.o vivid-vbi-cap.o vivid-vbi-out.o \
> -		vivid-osd.o
> +		vivid-osd.o vivid-meta-cap.o vivid-meta-gen.o
>  ifeq ($(CONFIG_VIDEO_VIVID_CEC),y)
>    vivid-objs += vivid-cec.o
>  endif
> diff --git a/drivers/media/platform/vivid/vivid-core.c b/drivers/media/platform/vivid/vivid-core.c
> index 53315c8dd2bb..75da1d6e9ed0 100644
> --- a/drivers/media/platform/vivid/vivid-core.c
> +++ b/drivers/media/platform/vivid/vivid-core.c
> @@ -37,6 +37,7 @@
>  #include "vivid-osd.h"
>  #include "vivid-cec.h"
>  #include "vivid-ctrls.h"
> +#include "vivid-meta-cap.h"
>  
>  #define VIVID_MODULE_NAME "vivid"
>  
> @@ -79,6 +80,10 @@ static int radio_tx_nr[VIVID_MAX_DEVS] = { [0 ... (VIVID_MAX_DEVS - 1)] = -1 };
>  module_param_array(radio_tx_nr, int, NULL, 0444);
>  MODULE_PARM_DESC(radio_tx_nr, " radioX start number, -1 is autodetect");
>  
> +static int meta_cap_nr[VIVID_MAX_DEVS] = { [0 ... (VIVID_MAX_DEVS - 1)] = -1 };
> +module_param_array(meta_cap_nr, int, NULL, 0444);
> +MODULE_PARM_DESC(meta_cap_nr, " videoX start number, -1 is autodetect");
> +
>  static int ccs_cap_mode[VIVID_MAX_DEVS] = { [0 ... (VIVID_MAX_DEVS - 1)] = -1 };
>  module_param_array(ccs_cap_mode, int, NULL, 0444);
>  MODULE_PARM_DESC(ccs_cap_mode, " capture crop/compose/scale mode:\n"
> @@ -95,8 +100,12 @@ static unsigned multiplanar[VIVID_MAX_DEVS] = { [0 ... (VIVID_MAX_DEVS - 1)] = 1
>  module_param_array(multiplanar, uint, NULL, 0444);
>  MODULE_PARM_DESC(multiplanar, " 1 (default) creates a single planar device, 2 creates a multiplanar device.");
>  
> -/* Default: video + vbi-cap (raw and sliced) + radio rx + radio tx + sdr + vbi-out + vid-out */
> -static unsigned node_types[VIVID_MAX_DEVS] = { [0 ... (VIVID_MAX_DEVS - 1)] = 0x1d3d };
> +/* Default: video + vbi-cap (raw and sliced) + radio rx + radio tx + sdr +

Put this on a new line. A comment is either of the form:

/* A one line comment */

or:

/*
 * A multiline comment.
 * Line 2
 */

> + * vbi-out + vid-out + meta-cap
> + */
> +static unsigned int node_types[VIVID_MAX_DEVS] = {
> +	[0 ... (VIVID_MAX_DEVS - 1)] = 0x21d3d
> +};
>  module_param_array(node_types, uint, NULL, 0444);
>  MODULE_PARM_DESC(node_types, " node types, default is 0x1d3d. Bitmask with the following meaning:\n"
>  			     "\t\t    bit 0: Video Capture node\n"
> @@ -106,7 +115,8 @@ MODULE_PARM_DESC(node_types, " node types, default is 0x1d3d. Bitmask with the f
>  			     "\t\t    bit 8: Video Output node\n"
>  			     "\t\t    bit 10-11: VBI Output node: 0 = none, 1 = raw vbi, 2 = sliced vbi, 3 = both\n"
>  			     "\t\t    bit 12: Radio Transmitter node\n"
> -			     "\t\t    bit 16: Framebuffer for testing overlays");
> +			     "\t\t    bit 16: Framebuffer for testing overlays\n"
> +			     "\t\t    bit 17: Metadata capture node\n");
>  
>  /* Default: 4 inputs */
>  static unsigned num_inputs[VIVID_MAX_DEVS] = { [0 ... (VIVID_MAX_DEVS - 1)] = 4 };
> @@ -205,7 +215,7 @@ static int vidioc_querycap(struct file *file, void  *priv,
>  	cap->capabilities = dev->vid_cap_caps | dev->vid_out_caps |
>  		dev->vbi_cap_caps | dev->vbi_out_caps |
>  		dev->radio_rx_caps | dev->radio_tx_caps |
> -		dev->sdr_cap_caps | V4L2_CAP_DEVICE_CAPS;
> +		dev->sdr_cap_caps | dev->meta_cap_caps | V4L2_CAP_DEVICE_CAPS;
>  	return 0;
>  }
>  
> @@ -433,7 +443,8 @@ static bool vivid_is_last_user(struct vivid_dev *dev)
>  			vivid_is_in_use(&dev->vbi_out_dev) +
>  			vivid_is_in_use(&dev->sdr_cap_dev) +
>  			vivid_is_in_use(&dev->radio_rx_dev) +
> -			vivid_is_in_use(&dev->radio_tx_dev);
> +			vivid_is_in_use(&dev->radio_tx_dev) +
> +			vivid_is_in_use(&dev->meta_cap_dev);
>  
>  	return uses == 1;
>  }
> @@ -459,6 +470,7 @@ static int vivid_fop_release(struct file *file)
>  		set_bit(V4L2_FL_REGISTERED, &dev->sdr_cap_dev.flags);
>  		set_bit(V4L2_FL_REGISTERED, &dev->radio_rx_dev.flags);
>  		set_bit(V4L2_FL_REGISTERED, &dev->radio_tx_dev.flags);
> +		set_bit(V4L2_FL_REGISTERED, &dev->meta_cap_dev.flags);
>  	}
>  	mutex_unlock(&dev->mutex);
>  	if (file->private_data == dev->overlay_cap_owner)
> @@ -604,6 +616,11 @@ static const struct v4l2_ioctl_ops vivid_ioctl_ops = {
>  	.vidioc_log_status		= vidioc_log_status,
>  	.vidioc_subscribe_event		= vidioc_subscribe_event,
>  	.vidioc_unsubscribe_event	= v4l2_event_unsubscribe,
> +
> +	.vidioc_enum_fmt_meta_cap	= vidioc_enum_fmt_meta_cap,
> +	.vidioc_g_fmt_meta_cap		= vidioc_g_fmt_meta_cap,
> +	.vidioc_s_fmt_meta_cap		= vidioc_g_fmt_meta_cap,
> +	.vidioc_try_fmt_meta_cap	= vidioc_g_fmt_meta_cap,
>  };
>  
>  /* -----------------------------------------------------------------
> @@ -818,6 +835,9 @@ static int vivid_create_instance(struct platform_device *pdev, int inst)
>  			dev->has_scaler_out ? 'Y' : 'N');
>  	}
>  
> +	/* do we create a meta capture device */
> +	dev->has_meta_cap = node_type & 0x20000;
> +
>  	/* end detecting feature set */
>  
>  	if (dev->has_vid_cap) {
> @@ -875,6 +895,11 @@ static int vivid_create_instance(struct platform_device *pdev, int inst)
>  		dev->radio_tx_caps = V4L2_CAP_RDS_OUTPUT | V4L2_CAP_MODULATOR |
>  				     V4L2_CAP_READWRITE;
>  
> +	/* set up the capabilities of meta capture device */
> +	if (dev->has_meta_cap)
> +		dev->meta_cap_caps = V4L2_CAP_META_CAPTURE |
> +				     V4L2_CAP_STREAMING | V4L2_CAP_READWRITE;
> +
>  	ret = -ENOMEM;
>  	/* initialize the test pattern generator */
>  	tpg_init(&dev->tpg, 640, 360);
> @@ -1078,6 +1103,7 @@ static int vivid_create_instance(struct platform_device *pdev, int inst)
>  	INIT_LIST_HEAD(&dev->vbi_cap_active);
>  	INIT_LIST_HEAD(&dev->vbi_out_active);
>  	INIT_LIST_HEAD(&dev->sdr_cap_active);
> +	INIT_LIST_HEAD(&dev->meta_cap_active);
>  
>  	INIT_LIST_HEAD(&dev->cec_work_list);
>  	spin_lock_init(&dev->cec_slock);
> @@ -1225,6 +1251,27 @@ static int vivid_create_instance(struct platform_device *pdev, int inst)
>  				dev->fb_info.node);
>  	}
>  
> +	if (dev->has_meta_cap) {
> +		/* initialize meta_cap queue */
> +		q = &dev->vb_meta_cap_q;
> +		q->type = V4L2_BUF_TYPE_META_CAPTURE;
> +		q->io_modes = VB2_MMAP | VB2_DMABUF | VB2_READ;
> +		if (!allocator)
> +			q->io_modes |= VB2_USERPTR;
> +		q->drv_priv = dev;
> +		q->buf_struct_size = sizeof(struct vivid_buffer);
> +		q->ops = &vivid_meta_cap_qops;
> +		q->mem_ops = vivid_mem_ops[allocator];
> +		q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
> +		q->min_buffers_needed = 2;
> +		q->lock = &dev->mutex;
> +		q->dev = dev->v4l2_dev.dev;
> +		q->supports_requests = true;
> +		ret = vb2_queue_init(q);
> +		if (ret)
> +			goto unreg_dev;
> +	}
> +
>  #ifdef CONFIG_VIDEO_VIVID_CEC
>  	if (dev->has_vid_cap && in_type_counter[HDMI]) {
>  		struct cec_adapter *adap;
> @@ -1265,6 +1312,7 @@ static int vivid_create_instance(struct platform_device *pdev, int inst)
>  	v4l2_ctrl_handler_setup(&dev->ctrl_hdl_radio_rx);
>  	v4l2_ctrl_handler_setup(&dev->ctrl_hdl_radio_tx);
>  	v4l2_ctrl_handler_setup(&dev->ctrl_hdl_sdr_cap);
> +	v4l2_ctrl_handler_setup(&dev->ctrl_hdl_meta_cap);
>  
>  	/* finally start creating the device nodes */
>  	if (dev->has_vid_cap) {
> @@ -1492,6 +1540,34 @@ static int vivid_create_instance(struct platform_device *pdev, int inst)
>  					  video_device_node_name(vfd));
>  	}
>  
> +	if (dev->has_meta_cap) {
> +		vfd = &dev->meta_cap_dev;
> +		snprintf(vfd->name, sizeof(vfd->name),
> +			 "vivid-%03d-meta-cap", inst);
> +		vfd->fops = &vivid_fops;
> +		vfd->ioctl_ops = &vivid_ioctl_ops;
> +		vfd->device_caps = dev->meta_cap_caps;
> +		vfd->release = video_device_release_empty;
> +		vfd->v4l2_dev = &dev->v4l2_dev;
> +		vfd->queue = &dev->vb_meta_cap_q;
> +		vfd->lock = &dev->mutex;
> +		video_set_drvdata(vfd, dev);
> +#ifdef CONFIG_MEDIA_CONTROLLER
> +		dev->meta_cap_pad.flags = MEDIA_PAD_FL_SINK;
> +		ret = media_entity_pads_init(&vfd->entity, 1,
> +					     &dev->meta_cap_pad);
> +		if (ret)
> +			goto unreg_dev;
> +#endif
> +		ret = video_register_device(vfd, VFL_TYPE_METADATA,
> +					    meta_cap_nr[inst]);
> +		if (ret < 0)
> +			goto unreg_dev;
> +		v4l2_info(&dev->v4l2_dev,
> +			  "V4L2 metadata capture device registered as %s\n",
> +			  video_device_node_name(vfd));
> +	}
> +
>  #ifdef CONFIG_MEDIA_CONTROLLER
>  	/* Register the media device */
>  	ret = media_device_register(&dev->mdev);
> @@ -1508,6 +1584,7 @@ static int vivid_create_instance(struct platform_device *pdev, int inst)
>  	return 0;
>  
>  unreg_dev:
> +	video_unregister_device(&dev->meta_cap_dev);
>  	video_unregister_device(&dev->radio_tx_dev);
>  	video_unregister_device(&dev->radio_rx_dev);
>  	video_unregister_device(&dev->sdr_cap_dev);
> @@ -1624,6 +1701,11 @@ static int vivid_remove(struct platform_device *pdev)
>  			unregister_framebuffer(&dev->fb_info);
>  			vivid_fb_release_buffers(dev);
>  		}
> +		if (dev->has_meta_cap) {
> +			v4l2_info(&dev->v4l2_dev, "unregistering %s\n",
> +				  video_device_node_name(&dev->meta_cap_dev));
> +			video_unregister_device(&dev->meta_cap_dev);
> +		}
>  		cec_unregister_adapter(dev->cec_rx_adap);
>  		for (j = 0; j < MAX_OUTPUTS; j++)
>  			cec_unregister_adapter(dev->cec_tx_adap[j]);
> diff --git a/drivers/media/platform/vivid/vivid-core.h b/drivers/media/platform/vivid/vivid-core.h
> index 7ebb14673c75..8ce26ba7d508 100644
> --- a/drivers/media/platform/vivid/vivid-core.h
> +++ b/drivers/media/platform/vivid/vivid-core.h
> @@ -18,6 +18,7 @@
>  #include <media/tpg/v4l2-tpg.h>
>  #include "vivid-rds-gen.h"
>  #include "vivid-vbi-gen.h"
> +#include "vivid-meta-gen.h"
>  
>  #define dprintk(dev, level, fmt, arg...) \
>  	v4l2_dbg(level, vivid_debug, &dev->v4l2_dev, fmt, ## arg)
> @@ -131,6 +132,7 @@ struct vivid_dev {
>  	struct media_pad		vbi_cap_pad;
>  	struct media_pad		vbi_out_pad;
>  	struct media_pad		sdr_cap_pad;
> +	struct media_pad		meta_cap_pad;
>  #endif
>  	struct v4l2_ctrl_handler	ctrl_hdl_user_gen;
>  	struct v4l2_ctrl_handler	ctrl_hdl_user_vid;
> @@ -153,6 +155,9 @@ struct vivid_dev {
>  	struct v4l2_ctrl_handler	ctrl_hdl_radio_tx;
>  	struct video_device		sdr_cap_dev;
>  	struct v4l2_ctrl_handler	ctrl_hdl_sdr_cap;
> +	struct video_device		meta_cap_dev;
> +	struct v4l2_ctrl_handler	ctrl_hdl_meta_cap;
> +
>  	spinlock_t			slock;
>  	struct mutex			mutex;
>  
> @@ -164,6 +169,7 @@ struct vivid_dev {
>  	u32				sdr_cap_caps;
>  	u32				radio_rx_caps;
>  	u32				radio_tx_caps;
> +	u32				meta_cap_caps;
>  
>  	/* supported features */
>  	bool				multiplanar;
> @@ -189,6 +195,7 @@ struct vivid_dev {
>  	bool				has_radio_tx;
>  	bool				has_sdr_cap;
>  	bool				has_fb;
> +	bool				has_meta_cap;
>  
>  	bool				can_loop_video;
>  
> @@ -390,6 +397,8 @@ struct vivid_dev {
>  	struct list_head		vid_cap_active;
>  	struct vb2_queue		vb_vbi_cap_q;
>  	struct list_head		vbi_cap_active;
> +	struct vb2_queue		vb_meta_cap_q;
> +	struct list_head		meta_cap_active;
>  
>  	/* thread for generating video capture stream */
>  	struct task_struct		*kthread_vid_cap;
> @@ -407,6 +416,9 @@ struct vivid_dev {
>  	u32				vbi_cap_seq_count;
>  	bool				vbi_cap_streaming;
>  	bool				stream_sliced_vbi_cap;
> +	u32				meta_cap_seq_start;
> +	u32				meta_cap_seq_count;
> +	bool				meta_cap_streaming;
>  
>  	/* video output */
>  	const struct vivid_fmt		*fmt_out;
> diff --git a/drivers/media/platform/vivid/vivid-ctrls.c b/drivers/media/platform/vivid/vivid-ctrls.c
> index cb19a9a73092..78ae0fe90081 100644
> --- a/drivers/media/platform/vivid/vivid-ctrls.c
> +++ b/drivers/media/platform/vivid/vivid-ctrls.c
> @@ -110,6 +110,7 @@ static int vivid_user_gen_s_ctrl(struct v4l2_ctrl *ctrl)
>  		clear_bit(V4L2_FL_REGISTERED, &dev->sdr_cap_dev.flags);
>  		clear_bit(V4L2_FL_REGISTERED, &dev->radio_rx_dev.flags);
>  		clear_bit(V4L2_FL_REGISTERED, &dev->radio_tx_dev.flags);
> +		clear_bit(V4L2_FL_REGISTERED, &dev->meta_cap_dev.flags);
>  		break;
>  	case VIVID_CID_BUTTON:
>  		dev->button_pressed = 30;
> @@ -1448,6 +1449,8 @@ int vivid_create_controls(struct vivid_dev *dev, bool show_ccs_cap,
>  	struct v4l2_ctrl_handler *hdl_radio_rx = &dev->ctrl_hdl_radio_rx;
>  	struct v4l2_ctrl_handler *hdl_radio_tx = &dev->ctrl_hdl_radio_tx;
>  	struct v4l2_ctrl_handler *hdl_sdr_cap = &dev->ctrl_hdl_sdr_cap;
> +	struct v4l2_ctrl_handler *hdl_meta_cap = &dev->ctrl_hdl_meta_cap;
> +
>  	struct v4l2_ctrl_config vivid_ctrl_dv_timings = {
>  		.ops = &vivid_vid_cap_ctrl_ops,
>  		.id = VIVID_CID_DV_TIMINGS,
> @@ -1486,6 +1489,8 @@ int vivid_create_controls(struct vivid_dev *dev, bool show_ccs_cap,
>  	v4l2_ctrl_new_custom(hdl_radio_tx, &vivid_ctrl_class, NULL);
>  	v4l2_ctrl_handler_init(hdl_sdr_cap, 19);
>  	v4l2_ctrl_new_custom(hdl_sdr_cap, &vivid_ctrl_class, NULL);
> +	v4l2_ctrl_handler_init(hdl_meta_cap, 2);
> +	v4l2_ctrl_new_custom(hdl_meta_cap, &vivid_ctrl_class, NULL);
>  
>  	/* User Controls */
>  	dev->volume = v4l2_ctrl_new_std(hdl_user_aud, NULL,
> @@ -1817,6 +1822,14 @@ int vivid_create_controls(struct vivid_dev *dev, bool show_ccs_cap,
>  			return hdl_sdr_cap->error;
>  		dev->sdr_cap_dev.ctrl_handler = hdl_sdr_cap;
>  	}
> +	if (dev->has_meta_cap) {
> +		v4l2_ctrl_add_handler(hdl_meta_cap, hdl_user_gen, NULL, false);
> +		v4l2_ctrl_add_handler(hdl_meta_cap, hdl_streaming, NULL, false);
> +		if (hdl_meta_cap->error)
> +			return hdl_meta_cap->error;
> +		dev->meta_cap_dev.ctrl_handler = hdl_meta_cap;
> +	}
> +
>  	return 0;
>  }
>  
> @@ -1836,4 +1849,5 @@ void vivid_free_controls(struct vivid_dev *dev)
>  	v4l2_ctrl_handler_free(&dev->ctrl_hdl_sdtv_cap);
>  	v4l2_ctrl_handler_free(&dev->ctrl_hdl_loop_cap);
>  	v4l2_ctrl_handler_free(&dev->ctrl_hdl_fb);
> +	v4l2_ctrl_handler_free(&dev->ctrl_hdl_meta_cap);
>  }
> diff --git a/drivers/media/platform/vivid/vivid-kthread-cap.c b/drivers/media/platform/vivid/vivid-kthread-cap.c
> index 003319d7816d..d79f652fe097 100644
> --- a/drivers/media/platform/vivid/vivid-kthread-cap.c
> +++ b/drivers/media/platform/vivid/vivid-kthread-cap.c
> @@ -39,6 +39,7 @@
>  #include "vivid-osd.h"
>  #include "vivid-ctrls.h"
>  #include "vivid-kthread-cap.h"
> +#include "vivid-meta-cap.h"
>  
>  static inline v4l2_std_id vivid_get_std_cap(const struct vivid_dev *dev)
>  {
> @@ -677,6 +678,7 @@ static noinline_for_stack void vivid_thread_vid_cap_tick(struct vivid_dev *dev,
>  {
>  	struct vivid_buffer *vid_cap_buf = NULL;
>  	struct vivid_buffer *vbi_cap_buf = NULL;
> +	struct vivid_buffer *meta_cap_buf = NULL;
>  	u64 f_time = 0;
>  
>  	dprintk(dev, 1, "Video Capture Thread Tick\n");
> @@ -704,9 +706,15 @@ static noinline_for_stack void vivid_thread_vid_cap_tick(struct vivid_dev *dev,
>  			list_del(&vbi_cap_buf->list);
>  		}
>  	}
> +	if (!list_empty(&dev->meta_cap_active)) {
> +		meta_cap_buf = list_entry(dev->meta_cap_active.next,
> +					  struct vivid_buffer, list);
> +		list_del(&meta_cap_buf->list);
> +	}
> +
>  	spin_unlock(&dev->slock);
>  
> -	if (!vid_cap_buf && !vbi_cap_buf)
> +	if (!vid_cap_buf && !vbi_cap_buf && !meta_cap_buf)
>  		goto update_mv;
>  
>  	f_time = dev->cap_frame_period * dev->vid_cap_seq_count +
> @@ -758,6 +766,20 @@ static noinline_for_stack void vivid_thread_vid_cap_tick(struct vivid_dev *dev,
>  		do_div(vbi_period, 100);
>  		vbi_cap_buf->vb.vb2_buf.timestamp = f_time + vbi_period;
>  	}
> +
> +	if (meta_cap_buf) {
> +		v4l2_ctrl_request_setup(meta_cap_buf->vb.vb2_buf.req_obj.req,
> +					&dev->ctrl_hdl_meta_cap);
> +		vivid_meta_cap_fillbuff(dev, meta_cap_buf);
> +		v4l2_ctrl_request_complete(meta_cap_buf->vb.vb2_buf.req_obj.req,
> +					   &dev->ctrl_hdl_meta_cap);
> +		vb2_buffer_done(&meta_cap_buf->vb.vb2_buf, dev->dqbuf_error ?
> +				VB2_BUF_STATE_ERROR : VB2_BUF_STATE_DONE);
> +		dprintk(dev, 2, "meta_cap %d done\n",
> +			meta_cap_buf->vb.vb2_buf.index);
> +		meta_cap_buf->vb.vb2_buf.timestamp = f_time;
> +	}
> +
>  	dev->dqbuf_error = false;
>  
>  update_mv:
> @@ -835,6 +857,7 @@ static int vivid_thread_vid_cap(void *data)
>  		dev->cap_seq_count = buffers_since_start + dev->cap_seq_offset;
>  		dev->vid_cap_seq_count = dev->cap_seq_count - dev->vid_cap_seq_start;
>  		dev->vbi_cap_seq_count = dev->cap_seq_count - dev->vbi_cap_seq_start;
> +		dev->meta_cap_seq_count = dev->cap_seq_count - dev->meta_cap_seq_start;
>  
>  		vivid_thread_vid_cap_tick(dev, dropped_bufs);
>  
> @@ -883,8 +906,10 @@ int vivid_start_generating_vid_cap(struct vivid_dev *dev, bool *pstreaming)
>  
>  		if (pstreaming == &dev->vid_cap_streaming)
>  			dev->vid_cap_seq_start = seq_count;
> -		else
> +		else if (pstreaming == &dev->vbi_cap_streaming)
>  			dev->vbi_cap_seq_start = seq_count;
> +		else
> +			dev->meta_cap_seq_start = seq_count;
>  		*pstreaming = true;
>  		return 0;
>  	}
> @@ -894,6 +919,7 @@ int vivid_start_generating_vid_cap(struct vivid_dev *dev, bool *pstreaming)
>  
>  	dev->vid_cap_seq_start = dev->seq_wrap * 128;
>  	dev->vbi_cap_seq_start = dev->seq_wrap * 128;
> +	dev->meta_cap_seq_start = dev->seq_wrap * 128;
>  
>  	dev->kthread_vid_cap = kthread_run(vivid_thread_vid_cap, dev,
>  			"%s-vid-cap", dev->v4l2_dev.name);
> @@ -951,7 +977,23 @@ void vivid_stop_generating_vid_cap(struct vivid_dev *dev, bool *pstreaming)
>  		}
>  	}
>  
> -	if (dev->vid_cap_streaming || dev->vbi_cap_streaming)
> +	if (pstreaming == &dev->meta_cap_streaming) {
> +		while (!list_empty(&dev->meta_cap_active)) {
> +			struct vivid_buffer *buf;
> +
> +			buf = list_entry(dev->meta_cap_active.next,
> +					 struct vivid_buffer, list);
> +			list_del(&buf->list);
> +			v4l2_ctrl_request_complete(buf->vb.vb2_buf.req_obj.req,
> +						   &dev->ctrl_hdl_meta_cap);
> +			vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
> +			dprintk(dev, 2, "meta_cap buffer %d done\n",
> +				buf->vb.vb2_buf.index);
> +		}
> +	}
> +
> +	if (dev->vid_cap_streaming || dev->vbi_cap_streaming ||
> +	    dev->meta_cap_streaming)
>  		return;
>  
>  	/* shutdown control thread */
> diff --git a/drivers/media/platform/vivid/vivid-meta-cap.c b/drivers/media/platform/vivid/vivid-meta-cap.c
> new file mode 100644
> index 000000000000..cb01f89333b1
> --- /dev/null
> +++ b/drivers/media/platform/vivid/vivid-meta-cap.c
> @@ -0,0 +1,175 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * vivid-meta-cap.c - meta capture support functions.
> + *
> + */
> +
> +#include <linux/errno.h>
> +#include <linux/kernel.h>
> +#include <linux/videodev2.h>
> +#include <media/v4l2-common.h>
> +#include <linux/usb/video.h>
> +
> +#include "vivid-core.h"
> +#include "vivid-kthread-cap.h"
> +#include "vivid-meta-cap.h"
> +#include "vivid-meta-gen.h"
> +
> +static int meta_cap_queue_setup(struct vb2_queue *vq, unsigned int *nbuffers,
> +				unsigned int *nplanes, unsigned int sizes[],
> +				struct device *alloc_devs[])
> +{
> +	struct vivid_dev *dev = vb2_get_drv_priv(vq);
> +	unsigned int size =  sizeof(struct vivid_uvc_meta_buf);
> +
> +	if (!vivid_is_webcam(dev))
> +		return -EINVAL;
> +
> +	if (*nplanes) {
> +		if (sizes[0] < size)
> +			return -EINVAL;
> +	} else {
> +		sizes[0] = size;
> +	}
> +
> +	if (vq->num_buffers + *nbuffers < 2)
> +		*nbuffers = 2 - vq->num_buffers;
> +
> +	*nplanes = 1;
> +	return 0;
> +}
> +
> +static int meta_cap_buf_prepare(struct vb2_buffer *vb)
> +{
> +	struct vivid_dev *dev = vb2_get_drv_priv(vb->vb2_queue);
> +	unsigned int size = sizeof(struct vivid_uvc_meta_buf);
> +
> +	dprintk(dev, 1, "%s\n", __func__);
> +
> +	if (dev->buf_prepare_error) {
> +		/*
> +		 * Error injection: test what happens if buf_prepare() returns
> +		 * an error.
> +		 */
> +		dev->buf_prepare_error = false;
> +		return -EINVAL;
> +	}
> +	if (vb2_plane_size(vb, 0) < size) {
> +		dprintk(dev, 1, "%s data will not fit into plane (%lu < %u)\n",
> +			__func__, vb2_plane_size(vb, 0), size);
> +		return -EINVAL;
> +	}
> +	vb2_set_plane_payload(vb, 0, size);
> +
> +	return 0;
> +}
> +
> +static void meta_cap_buf_queue(struct vb2_buffer *vb)
> +{
> +	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
> +	struct vivid_dev *dev = vb2_get_drv_priv(vb->vb2_queue);
> +	struct vivid_buffer *buf = container_of(vbuf, struct vivid_buffer, vb);
> +
> +	dprintk(dev, 1, "%s\n", __func__);
> +
> +	spin_lock(&dev->slock);
> +	list_add_tail(&buf->list, &dev->meta_cap_active);
> +	spin_unlock(&dev->slock);
> +}
> +
> +static int meta_cap_start_streaming(struct vb2_queue *vq, unsigned int count)
> +{
> +	struct vivid_dev *dev = vb2_get_drv_priv(vq);
> +	int err;
> +
> +	dprintk(dev, 1, "%s\n", __func__);
> +	dev->meta_cap_seq_count = 0;
> +	if (dev->start_streaming_error) {
> +		dev->start_streaming_error = false;
> +		err = -EINVAL;
> +	} else {
> +		err = vivid_start_generating_vid_cap(dev,
> +						     &dev->meta_cap_streaming);
> +	}
> +	if (err) {
> +		struct vivid_buffer *buf, *tmp;
> +
> +		list_for_each_entry_safe(buf, tmp,
> +					 &dev->meta_cap_active, list) {
> +			list_del(&buf->list);
> +			vb2_buffer_done(&buf->vb.vb2_buf,
> +					VB2_BUF_STATE_QUEUED);
> +		}
> +	}
> +	return err;
> +}
> +
> +/* abort streaming and wait for last buffer */
> +static void meta_cap_stop_streaming(struct vb2_queue *vq)
> +{
> +	struct vivid_dev *dev = vb2_get_drv_priv(vq);
> +
> +	dprintk(dev, 1, "%s\n", __func__);
> +	vivid_stop_generating_vid_cap(dev, &dev->meta_cap_streaming);
> +}
> +
> +static void meta_cap_buf_request_complete(struct vb2_buffer *vb)
> +{
> +	struct vivid_dev *dev = vb2_get_drv_priv(vb->vb2_queue);
> +
> +	v4l2_ctrl_request_complete(vb->req_obj.req, &dev->ctrl_hdl_meta_cap);
> +}
> +
> +const struct vb2_ops vivid_meta_cap_qops = {
> +	.queue_setup		= meta_cap_queue_setup,
> +	.buf_prepare		= meta_cap_buf_prepare,
> +	.buf_queue		= meta_cap_buf_queue,
> +	.start_streaming	= meta_cap_start_streaming,
> +	.stop_streaming		= meta_cap_stop_streaming,
> +	.buf_request_complete	= meta_cap_buf_request_complete,
> +	.wait_prepare		= vb2_ops_wait_prepare,
> +	.wait_finish		= vb2_ops_wait_finish,
> +};
> +
> +int vidioc_enum_fmt_meta_cap(struct file *file, void  *priv,
> +			     struct v4l2_fmtdesc *f)
> +{
> +	struct vivid_dev *dev = video_drvdata(file);
> +
> +	if (!vivid_is_webcam(dev))
> +		return -ENODATA;
> +
> +	if (f->index > 0)
> +		return -EINVAL;
> +
> +	f->type = V4L2_BUF_TYPE_META_CAPTURE;
> +	f->pixelformat = V4L2_META_FMT_UVC;
> +	return 0;
> +}
> +
> +int vidioc_g_fmt_meta_cap(struct file *file, void *priv,
> +			  struct v4l2_format *f)
> +{
> +	struct vivid_dev *dev = video_drvdata(file);
> +	struct v4l2_meta_format *meta = &f->fmt.meta;
> +
> +	if (!vivid_is_webcam(dev) || !dev->has_meta_cap)
> +		return -EINVAL;
> +
> +	meta->dataformat = V4L2_META_FMT_UVC;
> +	meta->buffersize = sizeof(struct vivid_uvc_meta_buf);
> +	return 0;
> +}
> +
> +void vivid_meta_cap_fillbuff(struct vivid_dev *dev, struct vivid_buffer *buf)
> +{
> +	struct vivid_uvc_meta_buf *vbuf = vb2_plane_vaddr(&buf->vb.vb2_buf, 0);
> +
> +	buf->vb.sequence = dev->meta_cap_seq_count;
> +	if (dev->field_cap == V4L2_FIELD_ALTERNATE)
> +		buf->vb.sequence /= 2;
> +	memset(vbuf, 1, vb2_plane_size(&buf->vb.vb2_buf, 0));
> +	vivid_meta_cap_gen(vbuf, buf->vb.sequence);
> +	dprintk(dev, 2, "%s ns %llu sof %u, len %u, flags 0x%x\n",
> +		__func__, vbuf->ns, vbuf->sof, vbuf->length, vbuf->flags);
> +}
> diff --git a/drivers/media/platform/vivid/vivid-meta-cap.h b/drivers/media/platform/vivid/vivid-meta-cap.h
> new file mode 100644
> index 000000000000..58d6c019fe96
> --- /dev/null
> +++ b/drivers/media/platform/vivid/vivid-meta-cap.h
> @@ -0,0 +1,18 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * vivid-meta-cap.h - meta capture support functions.
> + *
> + */
> +#ifndef _VIVID_META_CAP_H_
> +#define _VIVID_META_CAP_H_
> +
> +void vivid_meta_cap_fillbuff(struct vivid_dev *dev, struct vivid_buffer *buf);
> +
> +int vidioc_enum_fmt_meta_cap(struct file *file, void  *priv,
> +			     struct v4l2_fmtdesc *f);
> +
> +int vidioc_g_fmt_meta_cap(struct file *file, void *priv,
> +			  struct v4l2_format *f);
> +
> +extern const struct vb2_ops vivid_meta_cap_qops;
> +#endif
> diff --git a/drivers/media/platform/vivid/vivid-meta-gen.c b/drivers/media/platform/vivid/vivid-meta-gen.c
> new file mode 100644
> index 000000000000..32b3ca1aa206
> --- /dev/null
> +++ b/drivers/media/platform/vivid/vivid-meta-gen.c
> @@ -0,0 +1,25 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * vivid-meta-gen.c - metadata generator support functions.
> + *
> + */
> +
> +#include <linux/errno.h>
> +#include <linux/kernel.h>
> +#include <linux/ktime.h>
> +#include <linux/string.h>
> +#include <linux/videodev2.h>
> +#include <linux/usb/video.h>
> +
> +#include "vivid-meta-gen.h"
> +#include "vivid-core.h"
> +
> +void vivid_meta_cap_gen(struct vivid_uvc_meta_buf *meta, unsigned int seq)
> +{
> +	meta->ns = ktime_get_ns();
> +	meta->sof = seq;
> +	meta->length = sizeof(meta->ns) + sizeof(meta->sof) + 2;

This is wrong. The length is sizeof(*meta) - offsetof(struct vivid_uvc_meta_buf, length)

The sof value is a bit weird: I expect this to be updated for every buffer,
instead the first 4 frames have a sof of 0, the next four have a sof of 4, the
next 4 frames have a sof of 8, etc.

I would expect to see it increment by some value (4 seems a bit small) for every frame.
Looking at what happens with uvc it seems that for every frame a lot of metadata
packets arrive, but all with the same SOF. Whenever a new video frame begins the
SOF value increases by some small value (around 30).

In the emulation we don't need to have multiple metadata packets per frame, one is
sufficient. But I would expect to see the SOF increase for every frame.

> +	meta->flags = UVC_STREAM_EOH;
> +	if ((seq % 2) == 0)
> +		meta->flags |= UVC_STREAM_FID;

This seems to be always 1. I suspect meta->flags needs to be cleared somewhere.

Bit 1 (End of Frame) should also be set, since this is always the end of frame
since we transmit only one metadata buffer per frame.

> +}
> diff --git a/drivers/media/platform/vivid/vivid-meta-gen.h b/drivers/media/platform/vivid/vivid-meta-gen.h
> new file mode 100644
> index 000000000000..2af35a003338
> --- /dev/null
> +++ b/drivers/media/platform/vivid/vivid-meta-gen.h
> @@ -0,0 +1,18 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * vivid-meta-gen.h - meta generator support functions.
> + *
> + */
> +#ifndef _VIVID_META_GEN_H_
> +#define _VIVID_META_GEN_H_
> +
> +struct vivid_uvc_meta_buf {
> +	__u64 ns;
> +	__u16 sof;
> +	__u8 length;
> +	__u8 flags;
> +	__u8 buf[];
> +} __packed;
> +
> +void vivid_meta_cap_gen(struct vivid_uvc_meta_buf *meta, unsigned int seq);
> +#endif
> 

Regards,

	Hans