[PATCH 70/74] media: qcom: camss: video: Support metadata output nodes

[bod]

From: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>

Parameters need metadata output nodes. Register a node of video->type
V4L2_BUF_TYPE_META_OUTPUT alongside the metadata capture node:

- a source pad, VFL_DIR_TX and the META_OUTPUT format ioctls, returning
  the fixed format the producer sets before registration
- each buffer has a kernel copy, buf->meta: the payload is copied into
  it when the buffer is prepared, and the optional prepare_buffer()
  video op validates the copy, so what is validated is what the
  producer consumes
- like the capture node, it neither starts nor stops the line, and
  stopping it returns its buffers

Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>
---
 drivers/media/platform/qcom/camss/camss-video.c | 101 ++++++++++++++++++++++--
 drivers/media/platform/qcom/camss/camss-video.h |   8 ++
 2 files changed, 101 insertions(+), 8 deletions(-)

diff --git a/drivers/media/platform/qcom/camss/camss-video.c b/drivers/media/platform/qcom/camss/camss-video.c
index b8501c895d393..69cbe78b80622 100644
--- a/drivers/media/platform/qcom/camss/camss-video.c
+++ b/drivers/media/platform/qcom/camss/camss-video.c
@@ -414,6 +414,65 @@ static const struct vb2_ops msm_video_meta_vb2_q_ops = {
 	.unprepare_streaming = video_unprepare_streaming,
 };
 
+/*
+ * A metadata output buffer is copied to the kernel when it is prepared, so
+ * what is validated is what the producer later consumes.
+ */
+static int video_meta_out_buf_init(struct vb2_buffer *vb)
+{
+	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+	struct camss_video *video = vb2_get_drv_priv(vb->vb2_queue);
+	struct camss_buffer *buffer = container_of(vbuf, struct camss_buffer,
+						   vb);
+
+	buffer->meta = kvmalloc(video->active_fmt.fmt.meta.buffersize,
+				GFP_KERNEL);
+
+	return buffer->meta ? 0 : -ENOMEM;
+}
+
+static void video_meta_out_buf_cleanup(struct vb2_buffer *vb)
+{
+	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+	struct camss_buffer *buffer = container_of(vbuf, struct camss_buffer,
+						   vb);
+
+	kvfree(buffer->meta);
+	buffer->meta = NULL;
+}
+
+static int video_meta_out_buf_prepare(struct vb2_buffer *vb)
+{
+	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+	struct camss_video *video = vb2_get_drv_priv(vb->vb2_queue);
+	struct camss_buffer *buffer = container_of(vbuf, struct camss_buffer,
+						   vb);
+	size_t payload = vb2_get_plane_payload(vb, 0);
+
+	if (payload > video->active_fmt.fmt.meta.buffersize)
+		return -EINVAL;
+
+	memcpy(buffer->meta, vb2_plane_vaddr(vb, 0), payload);
+	vbuf->field = V4L2_FIELD_NONE;
+
+	if (video->ops->prepare_buffer)
+		return video->ops->prepare_buffer(video, buffer);
+
+	return 0;
+}
+
+static const struct vb2_ops msm_video_meta_out_vb2_q_ops = {
+	.queue_setup     = video_meta_queue_setup,
+	.buf_init        = video_meta_out_buf_init,
+	.buf_cleanup     = video_meta_out_buf_cleanup,
+	.buf_prepare     = video_meta_out_buf_prepare,
+	.buf_queue       = video_buf_queue,
+	.prepare_streaming = video_prepare_streaming,
+	.start_streaming = video_meta_start_streaming,
+	.stop_streaming  = video_meta_stop_streaming,
+	.unprepare_streaming = video_unprepare_streaming,
+};
+
 /* -----------------------------------------------------------------------------
  * V4L2 ioctls
  */
@@ -721,6 +780,23 @@ static const struct v4l2_ioctl_ops msm_vid_meta_ioctl_ops = {
 	.vidioc_streamoff		= vb2_ioctl_streamoff,
 };
 
+static const struct v4l2_ioctl_ops msm_vid_meta_out_ioctl_ops = {
+	.vidioc_querycap		= video_querycap,
+	.vidioc_enum_fmt_meta_out	= video_meta_enum_fmt,
+	.vidioc_g_fmt_meta_out		= video_meta_g_fmt,
+	.vidioc_s_fmt_meta_out		= video_meta_g_fmt,
+	.vidioc_try_fmt_meta_out	= video_meta_g_fmt,
+	.vidioc_reqbufs			= vb2_ioctl_reqbufs,
+	.vidioc_querybuf		= vb2_ioctl_querybuf,
+	.vidioc_qbuf			= vb2_ioctl_qbuf,
+	.vidioc_expbuf			= vb2_ioctl_expbuf,
+	.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
  */
@@ -796,7 +872,8 @@ static int msm_video_init_format(struct camss_video *video)
 int msm_video_register(struct camss_video *video, struct v4l2_device *v4l2_dev,
 		       const char *name)
 {
-	bool meta = video->type == V4L2_BUF_TYPE_META_CAPTURE;
+	bool meta_out = video->type == V4L2_BUF_TYPE_META_OUTPUT;
+	bool meta = meta_out || video->type == V4L2_BUF_TYPE_META_CAPTURE;
 	struct media_pad *pad = &video->pad;
 	struct video_device *vdev;
 	struct vb2_queue *q;
@@ -809,9 +886,13 @@ int msm_video_register(struct camss_video *video, struct v4l2_device *v4l2_dev,
 	q = &video->vb2_q;
 	q->drv_priv = video;
 	q->mem_ops = meta ? &vb2_vmalloc_memops : &vb2_dma_sg_memops;
-	q->ops = meta ? &msm_video_meta_vb2_q_ops : &msm_video_vb2_q_ops;
-	q->type = meta ? V4L2_BUF_TYPE_META_CAPTURE :
-			 V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+	if (meta_out)
+		q->ops = &msm_video_meta_out_vb2_q_ops;
+	else if (meta)
+		q->ops = &msm_video_meta_vb2_q_ops;
+	else
+		q->ops = &msm_video_vb2_q_ops;
+	q->type = meta ? video->type : V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
 	q->io_modes = meta ? VB2_DMABUF | VB2_MMAP :
 			     VB2_DMABUF | VB2_MMAP | VB2_READ;
 	q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
@@ -824,7 +905,7 @@ int msm_video_register(struct camss_video *video, struct v4l2_device *v4l2_dev,
 		goto error_vb2_init;
 	}
 
-	pad->flags = MEDIA_PAD_FL_SINK;
+	pad->flags = meta_out ? MEDIA_PAD_FL_SOURCE : MEDIA_PAD_FL_SINK;
 	ret = media_entity_pads_init(&vdev->entity, 1, pad);
 	if (ret < 0) {
 		dev_err(v4l2_dev->dev, "Failed to init video entity: %d\n",
@@ -836,7 +917,7 @@ int msm_video_register(struct camss_video *video, struct v4l2_device *v4l2_dev,
 
 	if (meta) {
 		/* dataformat and buffersize are set by the producer */
-		video->active_fmt.type = V4L2_BUF_TYPE_META_CAPTURE;
+		video->active_fmt.type = video->type;
 	} else {
 		ret = msm_video_init_format(video);
 		if (ret < 0) {
@@ -847,7 +928,11 @@ int msm_video_register(struct camss_video *video, struct v4l2_device *v4l2_dev,
 	}
 
 	vdev->fops = &msm_vid_fops;
-	if (meta) {
+	if (meta_out) {
+		vdev->device_caps = V4L2_CAP_META_OUTPUT | V4L2_CAP_STREAMING |
+				    V4L2_CAP_IO_MC;
+		vdev->ioctl_ops = &msm_vid_meta_out_ioctl_ops;
+	} else if (meta) {
 		vdev->device_caps = V4L2_CAP_META_CAPTURE | V4L2_CAP_STREAMING |
 				    V4L2_CAP_IO_MC;
 		vdev->ioctl_ops = &msm_vid_meta_ioctl_ops;
@@ -859,7 +944,7 @@ int msm_video_register(struct camss_video *video, struct v4l2_device *v4l2_dev,
 	}
 	vdev->release = msm_video_release;
 	vdev->v4l2_dev = v4l2_dev;
-	vdev->vfl_dir = VFL_DIR_RX;
+	vdev->vfl_dir = meta_out ? VFL_DIR_TX : VFL_DIR_RX;
 	vdev->queue = &video->vb2_q;
 	vdev->lock = &video->lock;
 	strscpy(vdev->name, name, sizeof(vdev->name));
diff --git a/drivers/media/platform/qcom/camss/camss-video.h b/drivers/media/platform/qcom/camss/camss-video.h
index d3e56e240a888..21a951b7fe9bc 100644
--- a/drivers/media/platform/qcom/camss/camss-video.h
+++ b/drivers/media/platform/qcom/camss/camss-video.h
@@ -23,6 +23,9 @@ struct camss_buffer {
 	struct vb2_v4l2_buffer vb;
 	dma_addr_t addr[3];
 	struct list_head queue;
+
+	/* Metadata output nodes: kernel copy of the buffer, validated at prepare */
+	void *meta;
 };
 
 struct camss_video;
@@ -31,6 +34,11 @@ struct camss_video_ops {
 	int (*queue_buffer)(struct camss_video *vid, struct camss_buffer *buf);
 	int (*flush_buffers)(struct camss_video *vid,
 			     enum vb2_buffer_state state);
+	/*
+	 * Optional, metadata output nodes: validate the kernel copy of a
+	 * buffer, buf->meta, when it is prepared
+	 */
+	int (*prepare_buffer)(struct camss_video *vid, struct camss_buffer *buf);
 };
 
 struct camss_video {

-- 
2.55.0