drivers/media/virtio/virtio_video_dec.c - third_party/linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0+
 /* Decoder for virtio video device.
  *
  * Copyright 2019 OpenSynergy GmbH.
  *
  * 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.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  */

 #include <media/v4l2-event.h>
 #include <media/v4l2-ioctl.h>

 #include "virtio_video.h"
 #include "virtio_video_dec.h"

 static void virtio_video_dec_buf_queue(struct vb2_buffer *vb)
 {
 	int i, ret;
 	struct vb2_buffer *src_buf;
 	struct vb2_v4l2_buffer *src_vb;
 	struct virtio_video_buffer *virtio_vb;
 	uint32_t data_size[VB2_MAX_PLANES] = {0};
 	struct vb2_v4l2_buffer *v4l2_vb = to_vb2_v4l2_buffer(vb);
 	struct virtio_video_stream *stream = vb2_get_drv_priv(vb->vb2_queue);
 	struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
 	struct virtio_video *vv = vvd->vv;

 	v4l2_m2m_buf_queue(stream->fh.m2m_ctx, v4l2_vb);

 	if ((stream->state != STREAM_STATE_INIT) ||
 	    !V4L2_TYPE_IS_OUTPUT(vb->vb2_queue->type))
 		return;

 	src_vb = v4l2_m2m_next_src_buf(stream->fh.m2m_ctx);
 	if (!src_vb) {
 		v4l2_err(&vv->v4l2_dev, "no src buf during initialization\n");
 		return;
 	}

 	src_buf = &src_vb->vb2_buf;
 	for (i = 0; i < src_buf->num_planes; ++i)
 		data_size[i] = src_buf->planes[i].bytesused;

 	virtio_vb = to_virtio_vb(src_buf);

 	ret = virtio_video_cmd_resource_queue(vv, stream->stream_id,
 					      virtio_vb, data_size,
 					      src_buf->num_planes,
 					      VIRTIO_VIDEO_QUEUE_TYPE_INPUT);
 	if (ret) {
 		v4l2_err(&vv->v4l2_dev, "failed to queue an src buffer\n");
 		return;
 	}

 	virtio_vb->queued = true;
 	stream->src_cleared = false;
 	src_vb = v4l2_m2m_src_buf_remove(stream->fh.m2m_ctx);
 }

 static int virtio_video_dec_start_streaming(struct vb2_queue *vq,
 					    unsigned int count)
 {
 	struct virtio_video_stream *stream = vb2_get_drv_priv(vq);

 	if (!V4L2_TYPE_IS_OUTPUT(vq->type) &&
 	    stream->state >= STREAM_STATE_INIT)
 		stream->state = STREAM_STATE_RUNNING;

 	return 0;
 }

 static void virtio_video_dec_stop_streaming(struct vb2_queue *vq)
 {
 	int ret, queue_type;
 	bool *cleared;
 	bool is_v4l2_output = V4L2_TYPE_IS_OUTPUT(vq->type);
 	struct virtio_video_stream *stream = vb2_get_drv_priv(vq);
 	struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
 	struct virtio_video *vv = vvd->vv;
 	struct vb2_v4l2_buffer *v4l2_vb;

 	if (is_v4l2_output) {
 		cleared = &stream->src_cleared;
 		queue_type = VIRTIO_VIDEO_QUEUE_TYPE_INPUT;
 	} else {
 		cleared = &stream->dst_cleared;
 		queue_type = VIRTIO_VIDEO_QUEUE_TYPE_OUTPUT;
 	}

 	ret = virtio_video_cmd_queue_clear(vv, stream, queue_type);
 	if (ret) {
 		v4l2_err(&vv->v4l2_dev, "failed to clear queue\n");
 		return;
 	}

 	ret = wait_event_timeout(vv->wq, *cleared, 5 * HZ);
 	if (ret == 0) {
 		v4l2_err(&vv->v4l2_dev, "timed out waiting for queue clear\n");
 		return;
 	}

 	for (;;) {
 		if (is_v4l2_output)
 			v4l2_vb = v4l2_m2m_src_buf_remove(stream->fh.m2m_ctx);
 		else
 			v4l2_vb = v4l2_m2m_dst_buf_remove(stream->fh.m2m_ctx);
 		if (!v4l2_vb)
 			break;
 		v4l2_m2m_buf_done(v4l2_vb, VB2_BUF_STATE_ERROR);
 	}
 }

 static const struct vb2_ops virtio_video_dec_qops = {
 	.queue_setup	 = virtio_video_queue_setup,
 	.buf_init	 = virtio_video_buf_init,
 	.buf_prepare	 = virtio_video_buf_prepare,
 	.buf_cleanup	 = virtio_video_buf_cleanup,
 	.buf_queue	 = virtio_video_dec_buf_queue,
 	.start_streaming = virtio_video_dec_start_streaming,
 	.stop_streaming  = virtio_video_dec_stop_streaming,
 	.wait_prepare	 = vb2_ops_wait_prepare,
 	.wait_finish	 = vb2_ops_wait_finish,
 };

 static int virtio_video_dec_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
 {
 	int ret = 0;
 	struct virtio_video_stream *stream = ctrl2stream(ctrl);

 	switch (ctrl->id) {
 	case V4L2_CID_MIN_BUFFERS_FOR_CAPTURE:
 		if (stream->state >= STREAM_STATE_METADATA)
 			ctrl->val = stream->out_info.min_buffers;
 		else
 			ctrl->val = 0;
 		break;
 	default:
 		ret = -EINVAL;
 	}

 	return ret;
 }

 static const struct v4l2_ctrl_ops virtio_video_dec_ctrl_ops = {
 	.g_volatile_ctrl	= virtio_video_dec_g_volatile_ctrl,
 };

 int virtio_video_dec_init_ctrls(struct virtio_video_stream *stream)
 {
 	struct v4l2_ctrl *ctrl;

 	v4l2_ctrl_handler_init(&stream->ctrl_handler, 1);

 	ctrl = v4l2_ctrl_new_std(&stream->ctrl_handler,
 				&virtio_video_dec_ctrl_ops,
 				V4L2_CID_MIN_BUFFERS_FOR_CAPTURE,
 				MIN_BUFS_MIN, MIN_BUFS_MAX, MIN_BUFS_STEP,
 				MIN_BUFS_DEF);

 	if (ctrl)
 		ctrl->flags |= V4L2_CTRL_FLAG_VOLATILE;

 	if (stream->ctrl_handler.error) {
 		int err = stream->ctrl_handler.error;

 		v4l2_ctrl_handler_free(&stream->ctrl_handler);
 		return err;
 	}

 	v4l2_ctrl_handler_setup(&stream->ctrl_handler);

 	return 0;
 }

 int virtio_video_dec_init_queues(void *priv, struct vb2_queue *src_vq,
 				 struct vb2_queue *dst_vq)
 {
 	int ret;
 	struct virtio_video_stream *stream = priv;
 	struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
 	struct virtio_video *vv = vvd->vv;
 	struct device *dev = vv->v4l2_dev.dev;

 	src_vq->type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
 	src_vq->io_modes = VB2_MMAP | VB2_DMABUF;
 	src_vq->drv_priv = stream;
 	src_vq->buf_struct_size = sizeof(struct virtio_video_buffer);
 	src_vq->ops = &virtio_video_dec_qops;
 	src_vq->mem_ops = virtio_video_mem_ops(vv);
 	src_vq->min_buffers_needed = stream->in_info.min_buffers;
 	src_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
 	src_vq->lock = &stream->vq_mutex;
 	src_vq->gfp_flags = virtio_video_gfp_flags(vv);
 	src_vq->dev = dev;

 	ret = vb2_queue_init(src_vq);
 	if (ret)
 		return ret;

 	dst_vq->type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
 	dst_vq->io_modes = VB2_MMAP | VB2_DMABUF;
 	dst_vq->drv_priv = stream;
 	dst_vq->buf_struct_size = sizeof(struct virtio_video_buffer);
 	dst_vq->ops = &virtio_video_dec_qops;
 	dst_vq->mem_ops = virtio_video_mem_ops(vv);
 	dst_vq->min_buffers_needed = stream->out_info.min_buffers;
 	dst_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
 	dst_vq->lock = &stream->vq_mutex;
 	dst_vq->gfp_flags = virtio_video_gfp_flags(vv);
 	dst_vq->dev = dev;

 	return vb2_queue_init(dst_vq);
 }

 static int virtio_video_try_decoder_cmd(struct file *file, void *fh,
 					struct v4l2_decoder_cmd *cmd)
 {
 	struct virtio_video_stream *stream = file2stream(file);
 	struct virtio_video_device *vvd = video_drvdata(file);
 	struct virtio_video *vv = vvd->vv;

 	if (stream->state == STREAM_STATE_DRAIN)
 		return -EBUSY;

 	switch (cmd->cmd) {
 	case V4L2_DEC_CMD_STOP:
 	case V4L2_DEC_CMD_START:
 		if (cmd->flags != 0) {
 			v4l2_err(&vv->v4l2_dev, "flags=%u are not supported",
 				 cmd->flags);
 			return -EINVAL;
 		}
 		break;
 	default:
 		return -EINVAL;
 	}

 	return 0;
 }

 static int virtio_video_decoder_cmd(struct file *file, void *fh,
 				    struct v4l2_decoder_cmd *cmd)
 {
 	int ret;
 	struct vb2_queue *src_vq, *dst_vq;
 	struct virtio_video_stream *stream = file2stream(file);
 	struct virtio_video_device *vvd = video_drvdata(file);
 	struct virtio_video *vv = vvd->vv;
 	int current_state;

 	ret = virtio_video_try_decoder_cmd(file, fh, cmd);
 	if (ret < 0)
 		return ret;

 	dst_vq = v4l2_m2m_get_vq(stream->fh.m2m_ctx,
 				 V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE);

 	switch (cmd->cmd) {
 	case V4L2_DEC_CMD_START:
 		vb2_clear_last_buffer_dequeued(dst_vq);
 		if (stream->state == STREAM_STATE_STOPPED) {
 			stream->state = STREAM_STATE_RUNNING;
 		} else {
 			v4l2_warn(&vv->v4l2_dev, "state(%d) is not STOPPED\n",
 				  stream->state);
 		}
 		break;
 	case V4L2_DEC_CMD_STOP:
 		src_vq = v4l2_m2m_get_vq(stream->fh.m2m_ctx,
 					 V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE);

 		if (!vb2_is_streaming(src_vq)) {
 			v4l2_dbg(1, vv->debug,
 				 &vv->v4l2_dev, "output is not streaming\n");
 			return 0;
 		}

 		if (!vb2_is_streaming(dst_vq)) {
 			v4l2_dbg(1, vv->debug,
 				 &vv->v4l2_dev, "capture is not streaming\n");
 			return 0;
 		}

 		current_state = stream->state;
 		stream->state = STREAM_STATE_DRAIN;
 		ret = virtio_video_cmd_stream_drain(vv, stream->stream_id);
 		if (ret) {
 			stream->state = current_state;
 			v4l2_err(&vv->v4l2_dev, "failed to drain stream\n");
 			return ret;
 		}
 		break;
 	default:
 		return -EINVAL;
 	}

 	return 0;
 }

 static int virtio_video_dec_enum_fmt_vid_cap(struct file *file, void *fh,
 					     struct v4l2_fmtdesc *f)
 {
 	struct virtio_video_stream *stream = file2stream(file);
 	struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
 	struct video_format_info *info = NULL;
 	struct video_format *fmt = NULL;
 	unsigned long input_mask = 0;
 	int idx = 0, bit_num = 0;

 	if (f->type != V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
 		return -EINVAL;

 	if (f->index >= vvd->num_output_fmts)
 		return -EINVAL;

 	info = &stream->in_info;
 	list_for_each_entry(fmt, &vvd->input_fmt_list, formats_list_entry) {
 		if (info->fourcc_format == fmt->desc.format) {
 			input_mask = fmt->desc.mask;
 			break;
 		}
 	}

 	if (input_mask == 0)
 		return -EINVAL;

 	list_for_each_entry(fmt, &vvd->output_fmt_list, formats_list_entry) {
 		if (test_bit(bit_num, &input_mask)) {
 			if (f->index == idx) {
 				f->pixelformat = fmt->desc.format;
 				return 0;
 			}
 			idx++;
 		}
 		bit_num++;
 	}
 	return -EINVAL;
 }


 static int virtio_video_dec_enum_fmt_vid_out(struct file *file, void *fh,
 					     struct v4l2_fmtdesc *f)
 {
 	struct virtio_video_stream *stream = file2stream(file);
 	struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
 	struct video_format *fmt = NULL;
 	int idx = 0;

 	if (f->type != V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
 		return -EINVAL;

 	if (f->index >= vvd->num_input_fmts)
 		return -EINVAL;

 	list_for_each_entry(fmt, &vvd->input_fmt_list, formats_list_entry) {
 		if (f->index == idx) {
 			f->pixelformat = fmt->desc.format;
 			return 0;
 		}
 		idx++;
 	}
 	return -EINVAL;
 }

 static int virtio_video_dec_s_fmt(struct file *file, void *fh,
 				  struct v4l2_format *f)
 {
 	int ret;
 	struct virtio_video_stream *stream = file2stream(file);

 	ret = virtio_video_s_fmt(file, fh, f);
 	if (ret)
 		return ret;

 	if (V4L2_TYPE_IS_OUTPUT(f->type)) {
 		if (stream->state == STREAM_STATE_IDLE)
 			stream->state = STREAM_STATE_INIT;
 	}

 	return 0;
 }

 static const struct v4l2_ioctl_ops virtio_video_dec_ioctl_ops = {
 	.vidioc_querycap	= virtio_video_querycap,

 	.vidioc_enum_fmt_vid_cap = virtio_video_dec_enum_fmt_vid_cap,
 	.vidioc_g_fmt_vid_cap	= virtio_video_g_fmt,
 	.vidioc_s_fmt_vid_cap	= virtio_video_dec_s_fmt,

 	.vidioc_g_fmt_vid_cap_mplane	= virtio_video_g_fmt,
 	.vidioc_s_fmt_vid_cap_mplane	= virtio_video_dec_s_fmt,

 	.vidioc_enum_fmt_vid_out = virtio_video_dec_enum_fmt_vid_out,
 	.vidioc_g_fmt_vid_out	= virtio_video_g_fmt,
 	.vidioc_s_fmt_vid_out	= virtio_video_dec_s_fmt,

 	.vidioc_g_fmt_vid_out_mplane	= virtio_video_g_fmt,
 	.vidioc_s_fmt_vid_out_mplane	= virtio_video_dec_s_fmt,

 	.vidioc_g_selection = virtio_video_g_selection,
 	.vidioc_s_selection = virtio_video_s_selection,

 	.vidioc_try_decoder_cmd	= virtio_video_try_decoder_cmd,
 	.vidioc_decoder_cmd	= virtio_video_decoder_cmd,
 	.vidioc_enum_frameintervals = virtio_video_enum_framemintervals,
 	.vidioc_enum_framesizes = virtio_video_enum_framesizes,

 	.vidioc_reqbufs		= virtio_video_reqbufs,
 	.vidioc_querybuf	= v4l2_m2m_ioctl_querybuf,
 	.vidioc_qbuf		= v4l2_m2m_ioctl_qbuf,
 	.vidioc_dqbuf		= v4l2_m2m_ioctl_dqbuf,
 	.vidioc_prepare_buf	= v4l2_m2m_ioctl_prepare_buf,
 	.vidioc_create_bufs	= v4l2_m2m_ioctl_create_bufs,
 	.vidioc_expbuf		= v4l2_m2m_ioctl_expbuf,

 	.vidioc_streamon	= v4l2_m2m_ioctl_streamon,
 	.vidioc_streamoff	= v4l2_m2m_ioctl_streamoff,

 	.vidioc_subscribe_event = virtio_video_subscribe_event,
 	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
 };

 int virtio_video_dec_init(struct video_device *vd)
 {
 	vd->ioctl_ops = &virtio_video_dec_ioctl_ops;
 	strscpy(vd->name, "stateful-decoder", sizeof(vd->name));

 	return 0;
 }
	// SPDX-License-Identifier: GPL-2.0+
	/* Decoder for virtio video device.
	*
	* Copyright 2019 OpenSynergy GmbH.
	*
	* 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.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, see <http://www.gnu.org/licenses/>.
	*/

	#include <media/v4l2-event.h>
	#include <media/v4l2-ioctl.h>

	#include "virtio_video.h"
	#include "virtio_video_dec.h"

	static void virtio_video_dec_buf_queue(struct vb2_buffer *vb)
	{
	int i, ret;
	struct vb2_buffer *src_buf;
	struct vb2_v4l2_buffer *src_vb;
	struct virtio_video_buffer *virtio_vb;
	uint32_t data_size[VB2_MAX_PLANES] = {0};
	struct vb2_v4l2_buffer *v4l2_vb = to_vb2_v4l2_buffer(vb);
	struct virtio_video_stream *stream = vb2_get_drv_priv(vb->vb2_queue);
	struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
	struct virtio_video *vv = vvd->vv;

	v4l2_m2m_buf_queue(stream->fh.m2m_ctx, v4l2_vb);

	if ((stream->state != STREAM_STATE_INIT) \|\|
	!V4L2_TYPE_IS_OUTPUT(vb->vb2_queue->type))
	return;

	src_vb = v4l2_m2m_next_src_buf(stream->fh.m2m_ctx);
	if (!src_vb) {
	v4l2_err(&vv->v4l2_dev, "no src buf during initialization\n");
	return;
	}

	src_buf = &src_vb->vb2_buf;
	for (i = 0; i < src_buf->num_planes; ++i)
	data_size[i] = src_buf->planes[i].bytesused;

	virtio_vb = to_virtio_vb(src_buf);

	ret = virtio_video_cmd_resource_queue(vv, stream->stream_id,
	virtio_vb, data_size,
	src_buf->num_planes,
	VIRTIO_VIDEO_QUEUE_TYPE_INPUT);
	if (ret) {
	v4l2_err(&vv->v4l2_dev, "failed to queue an src buffer\n");
	return;
	}

	virtio_vb->queued = true;
	stream->src_cleared = false;
	src_vb = v4l2_m2m_src_buf_remove(stream->fh.m2m_ctx);
	}

	static int virtio_video_dec_start_streaming(struct vb2_queue *vq,
	unsigned int count)
	{
	struct virtio_video_stream *stream = vb2_get_drv_priv(vq);

	if (!V4L2_TYPE_IS_OUTPUT(vq->type) &&
	stream->state >= STREAM_STATE_INIT)
	stream->state = STREAM_STATE_RUNNING;

	return 0;
	}

	static void virtio_video_dec_stop_streaming(struct vb2_queue *vq)
	{
	int ret, queue_type;
	bool *cleared;
	bool is_v4l2_output = V4L2_TYPE_IS_OUTPUT(vq->type);
	struct virtio_video_stream *stream = vb2_get_drv_priv(vq);
	struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
	struct virtio_video *vv = vvd->vv;
	struct vb2_v4l2_buffer *v4l2_vb;

	if (is_v4l2_output) {
	cleared = &stream->src_cleared;
	queue_type = VIRTIO_VIDEO_QUEUE_TYPE_INPUT;
	} else {
	cleared = &stream->dst_cleared;
	queue_type = VIRTIO_VIDEO_QUEUE_TYPE_OUTPUT;
	}

	ret = virtio_video_cmd_queue_clear(vv, stream, queue_type);
	if (ret) {
	v4l2_err(&vv->v4l2_dev, "failed to clear queue\n");
	return;
	}

	ret = wait_event_timeout(vv->wq, cleared, 5 HZ);
	if (ret == 0) {
	v4l2_err(&vv->v4l2_dev, "timed out waiting for queue clear\n");
	return;
	}

	for (;;) {
	if (is_v4l2_output)
	v4l2_vb = v4l2_m2m_src_buf_remove(stream->fh.m2m_ctx);
	else
	v4l2_vb = v4l2_m2m_dst_buf_remove(stream->fh.m2m_ctx);
	if (!v4l2_vb)
	break;
	v4l2_m2m_buf_done(v4l2_vb, VB2_BUF_STATE_ERROR);
	}
	}

	static const struct vb2_ops virtio_video_dec_qops = {
	.queue_setup = virtio_video_queue_setup,
	.buf_init = virtio_video_buf_init,
	.buf_prepare = virtio_video_buf_prepare,
	.buf_cleanup = virtio_video_buf_cleanup,
	.buf_queue = virtio_video_dec_buf_queue,
	.start_streaming = virtio_video_dec_start_streaming,
	.stop_streaming = virtio_video_dec_stop_streaming,
	.wait_prepare = vb2_ops_wait_prepare,
	.wait_finish = vb2_ops_wait_finish,
	};

	static int virtio_video_dec_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
	{
	int ret = 0;
	struct virtio_video_stream *stream = ctrl2stream(ctrl);

	switch (ctrl->id) {
	case V4L2_CID_MIN_BUFFERS_FOR_CAPTURE:
	if (stream->state >= STREAM_STATE_METADATA)
	ctrl->val = stream->out_info.min_buffers;
	else
	ctrl->val = 0;
	break;
	default:
	ret = -EINVAL;
	}

	return ret;
	}

	static const struct v4l2_ctrl_ops virtio_video_dec_ctrl_ops = {
	.g_volatile_ctrl = virtio_video_dec_g_volatile_ctrl,
	};

	int virtio_video_dec_init_ctrls(struct virtio_video_stream *stream)
	{
	struct v4l2_ctrl *ctrl;

	v4l2_ctrl_handler_init(&stream->ctrl_handler, 1);

	ctrl = v4l2_ctrl_new_std(&stream->ctrl_handler,
	&virtio_video_dec_ctrl_ops,
	V4L2_CID_MIN_BUFFERS_FOR_CAPTURE,
	MIN_BUFS_MIN, MIN_BUFS_MAX, MIN_BUFS_STEP,
	MIN_BUFS_DEF);

	if (ctrl)
	ctrl->flags \|= V4L2_CTRL_FLAG_VOLATILE;

	if (stream->ctrl_handler.error) {
	int err = stream->ctrl_handler.error;

	v4l2_ctrl_handler_free(&stream->ctrl_handler);
	return err;
	}

	v4l2_ctrl_handler_setup(&stream->ctrl_handler);

	return 0;
	}

	int virtio_video_dec_init_queues(void priv, struct vb2_queue src_vq,
	struct vb2_queue *dst_vq)
	{
	int ret;
	struct virtio_video_stream *stream = priv;
	struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
	struct virtio_video *vv = vvd->vv;
	struct device *dev = vv->v4l2_dev.dev;

	src_vq->type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
	src_vq->io_modes = VB2_MMAP \| VB2_DMABUF;
	src_vq->drv_priv = stream;
	src_vq->buf_struct_size = sizeof(struct virtio_video_buffer);
	src_vq->ops = &virtio_video_dec_qops;
	src_vq->mem_ops = virtio_video_mem_ops(vv);
	src_vq->min_buffers_needed = stream->in_info.min_buffers;
	src_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
	src_vq->lock = &stream->vq_mutex;
	src_vq->gfp_flags = virtio_video_gfp_flags(vv);
	src_vq->dev = dev;

	ret = vb2_queue_init(src_vq);
	if (ret)
	return ret;

	dst_vq->type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
	dst_vq->io_modes = VB2_MMAP \| VB2_DMABUF;
	dst_vq->drv_priv = stream;
	dst_vq->buf_struct_size = sizeof(struct virtio_video_buffer);
	dst_vq->ops = &virtio_video_dec_qops;
	dst_vq->mem_ops = virtio_video_mem_ops(vv);
	dst_vq->min_buffers_needed = stream->out_info.min_buffers;
	dst_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
	dst_vq->lock = &stream->vq_mutex;
	dst_vq->gfp_flags = virtio_video_gfp_flags(vv);
	dst_vq->dev = dev;

	return vb2_queue_init(dst_vq);
	}

	static int virtio_video_try_decoder_cmd(struct file file, void fh,
	struct v4l2_decoder_cmd *cmd)
	{
	struct virtio_video_stream *stream = file2stream(file);
	struct virtio_video_device *vvd = video_drvdata(file);
	struct virtio_video *vv = vvd->vv;

	if (stream->state == STREAM_STATE_DRAIN)
	return -EBUSY;

	switch (cmd->cmd) {
	case V4L2_DEC_CMD_STOP:
	case V4L2_DEC_CMD_START:
	if (cmd->flags != 0) {
	v4l2_err(&vv->v4l2_dev, "flags=%u are not supported",
	cmd->flags);
	return -EINVAL;
	}
	break;
	default:
	return -EINVAL;
	}

	return 0;
	}

	static int virtio_video_decoder_cmd(struct file file, void fh,
	struct v4l2_decoder_cmd *cmd)
	{
	int ret;
	struct vb2_queue src_vq, dst_vq;
	struct virtio_video_stream *stream = file2stream(file);
	struct virtio_video_device *vvd = video_drvdata(file);
	struct virtio_video *vv = vvd->vv;
	int current_state;

	ret = virtio_video_try_decoder_cmd(file, fh, cmd);
	if (ret < 0)
	return ret;

	dst_vq = v4l2_m2m_get_vq(stream->fh.m2m_ctx,
	V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE);

	switch (cmd->cmd) {
	case V4L2_DEC_CMD_START:
	vb2_clear_last_buffer_dequeued(dst_vq);
	if (stream->state == STREAM_STATE_STOPPED) {
	stream->state = STREAM_STATE_RUNNING;
	} else {
	v4l2_warn(&vv->v4l2_dev, "state(%d) is not STOPPED\n",
	stream->state);
	}
	break;
	case V4L2_DEC_CMD_STOP:
	src_vq = v4l2_m2m_get_vq(stream->fh.m2m_ctx,
	V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE);

	if (!vb2_is_streaming(src_vq)) {
	v4l2_dbg(1, vv->debug,
	&vv->v4l2_dev, "output is not streaming\n");
	return 0;
	}

	if (!vb2_is_streaming(dst_vq)) {
	v4l2_dbg(1, vv->debug,
	&vv->v4l2_dev, "capture is not streaming\n");
	return 0;
	}

	current_state = stream->state;
	stream->state = STREAM_STATE_DRAIN;
	ret = virtio_video_cmd_stream_drain(vv, stream->stream_id);
	if (ret) {
	stream->state = current_state;
	v4l2_err(&vv->v4l2_dev, "failed to drain stream\n");
	return ret;
	}
	break;
	default:
	return -EINVAL;
	}

	return 0;
	}

	static int virtio_video_dec_enum_fmt_vid_cap(struct file file, void fh,
	struct v4l2_fmtdesc *f)
	{
	struct virtio_video_stream *stream = file2stream(file);
	struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
	struct video_format_info *info = NULL;
	struct video_format *fmt = NULL;
	unsigned long input_mask = 0;
	int idx = 0, bit_num = 0;

	if (f->type != V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
	return -EINVAL;

	if (f->index >= vvd->num_output_fmts)
	return -EINVAL;

	info = &stream->in_info;
	list_for_each_entry(fmt, &vvd->input_fmt_list, formats_list_entry) {
	if (info->fourcc_format == fmt->desc.format) {
	input_mask = fmt->desc.mask;
	break;
	}
	}

	if (input_mask == 0)
	return -EINVAL;

	list_for_each_entry(fmt, &vvd->output_fmt_list, formats_list_entry) {
	if (test_bit(bit_num, &input_mask)) {
	if (f->index == idx) {
	f->pixelformat = fmt->desc.format;
	return 0;
	}
	idx++;
	}
	bit_num++;
	}
	return -EINVAL;
	}


	static int virtio_video_dec_enum_fmt_vid_out(struct file file, void fh,
	struct v4l2_fmtdesc *f)
	{
	struct virtio_video_stream *stream = file2stream(file);
	struct virtio_video_device *vvd = to_virtio_vd(stream->video_dev);
	struct video_format *fmt = NULL;
	int idx = 0;

	if (f->type != V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
	return -EINVAL;

	if (f->index >= vvd->num_input_fmts)
	return -EINVAL;

	list_for_each_entry(fmt, &vvd->input_fmt_list, formats_list_entry) {
	if (f->index == idx) {
	f->pixelformat = fmt->desc.format;
	return 0;
	}
	idx++;
	}
	return -EINVAL;
	}

	static int virtio_video_dec_s_fmt(struct file file, void fh,
	struct v4l2_format *f)
	{
	int ret;
	struct virtio_video_stream *stream = file2stream(file);

	ret = virtio_video_s_fmt(file, fh, f);
	if (ret)
	return ret;

	if (V4L2_TYPE_IS_OUTPUT(f->type)) {
	if (stream->state == STREAM_STATE_IDLE)
	stream->state = STREAM_STATE_INIT;
	}

	return 0;
	}

	static const struct v4l2_ioctl_ops virtio_video_dec_ioctl_ops = {
	.vidioc_querycap = virtio_video_querycap,

	.vidioc_enum_fmt_vid_cap = virtio_video_dec_enum_fmt_vid_cap,
	.vidioc_g_fmt_vid_cap = virtio_video_g_fmt,
	.vidioc_s_fmt_vid_cap = virtio_video_dec_s_fmt,

	.vidioc_g_fmt_vid_cap_mplane = virtio_video_g_fmt,
	.vidioc_s_fmt_vid_cap_mplane = virtio_video_dec_s_fmt,

	.vidioc_enum_fmt_vid_out = virtio_video_dec_enum_fmt_vid_out,
	.vidioc_g_fmt_vid_out = virtio_video_g_fmt,
	.vidioc_s_fmt_vid_out = virtio_video_dec_s_fmt,

	.vidioc_g_fmt_vid_out_mplane = virtio_video_g_fmt,
	.vidioc_s_fmt_vid_out_mplane = virtio_video_dec_s_fmt,

	.vidioc_g_selection = virtio_video_g_selection,
	.vidioc_s_selection = virtio_video_s_selection,

	.vidioc_try_decoder_cmd = virtio_video_try_decoder_cmd,
	.vidioc_decoder_cmd = virtio_video_decoder_cmd,
	.vidioc_enum_frameintervals = virtio_video_enum_framemintervals,
	.vidioc_enum_framesizes = virtio_video_enum_framesizes,

	.vidioc_reqbufs = virtio_video_reqbufs,
	.vidioc_querybuf = v4l2_m2m_ioctl_querybuf,
	.vidioc_qbuf = v4l2_m2m_ioctl_qbuf,
	.vidioc_dqbuf = v4l2_m2m_ioctl_dqbuf,
	.vidioc_prepare_buf = v4l2_m2m_ioctl_prepare_buf,
	.vidioc_create_bufs = v4l2_m2m_ioctl_create_bufs,
	.vidioc_expbuf = v4l2_m2m_ioctl_expbuf,

	.vidioc_streamon = v4l2_m2m_ioctl_streamon,
	.vidioc_streamoff = v4l2_m2m_ioctl_streamoff,

	.vidioc_subscribe_event = virtio_video_subscribe_event,
	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
	};

	int virtio_video_dec_init(struct video_device *vd)
	{
	vd->ioctl_ops = &virtio_video_dec_ioctl_ops;
	strscpy(vd->name, "stateful-decoder", sizeof(vd->name));

	return 0;
	}