media: rzg2l-cru: video: Implement .link_validate() callback

Implement the `.link_validate()` callback for the video node and move the
format checking into this function. This change allows the removal of
`rzg2l_cru_mc_validate_format()`.

Note, the fmt.format.code and fmt.format.field checks have be dropped as
the subdev .set_fmt() handler ensures that those fields always hold valid
values.

Suggested-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Link: https://lore.kernel.org/r/20241018133446.223516-19-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>

drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c

@@ -189,46 +189,6 @@ static void rzg2l_cru_buffer_queue(struct vb2_buffer *vb)
 	spin_unlock_irqrestore(&cru->qlock, flags);
 }
 
-static int rzg2l_cru_mc_validate_format(struct rzg2l_cru_dev *cru,
-					struct v4l2_subdev *sd,
-					struct media_pad *pad)
-{
-	struct v4l2_subdev_format fmt = {
-		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
-	};
-
-	fmt.pad = pad->index;
-	if (v4l2_subdev_call_state_active(sd, pad, get_fmt, &fmt))
-		return -EPIPE;
-
-	switch (fmt.format.code) {
-	case MEDIA_BUS_FMT_UYVY8_1X16:
-		break;
-	default:
-		return -EPIPE;
-	}
-
-	switch (fmt.format.field) {
-	case V4L2_FIELD_TOP:
-	case V4L2_FIELD_BOTTOM:
-	case V4L2_FIELD_NONE:
-	case V4L2_FIELD_INTERLACED_TB:
-	case V4L2_FIELD_INTERLACED_BT:
-	case V4L2_FIELD_INTERLACED:
-	case V4L2_FIELD_SEQ_TB:
-	case V4L2_FIELD_SEQ_BT:
-		break;
-	default:
-		return -EPIPE;
-	}
-
-	if (fmt.format.width != cru->format.width ||
-	    fmt.format.height != cru->format.height)
-		return -EPIPE;
-
-	return 0;
-}
-
 static void rzg2l_cru_set_slot_addr(struct rzg2l_cru_dev *cru,
 				    int slot, dma_addr_t addr)
 {
@@ -532,10 +492,6 @@ static int rzg2l_cru_set_stream(struct rzg2l_cru_dev *cru, int on)
 		return stream_off_ret;
 	}
 
-	ret = rzg2l_cru_mc_validate_format(cru, sd, pad);
-	if (ret)
-		return ret;
-
 	pipe = media_entity_pipeline(&sd->entity) ? : &cru->vdev.pipe;
 	ret = video_device_pipeline_start(&cru->vdev, pipe);
 	if (ret)
@@ -986,6 +942,43 @@ static const struct v4l2_file_operations rzg2l_cru_fops = {
 	.read		= vb2_fop_read,
 };
 
+/* -----------------------------------------------------------------------------
+ * Media entity operations
+ */
+
+static int rzg2l_cru_video_link_validate(struct media_link *link)
+{
+	struct v4l2_subdev_format fmt = {
+		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
+	};
+	const struct rzg2l_cru_ip_format *video_fmt;
+	struct v4l2_subdev *subdev;
+	struct rzg2l_cru_dev *cru;
+	int ret;
+
+	subdev = media_entity_to_v4l2_subdev(link->source->entity);
+	fmt.pad = link->source->index;
+	ret = v4l2_subdev_call(subdev, pad, get_fmt, NULL, &fmt);
+	if (ret < 0)
+		return ret == -ENOIOCTLCMD ? -EINVAL : ret;
+
+	cru = container_of(media_entity_to_video_device(link->sink->entity),
+			   struct rzg2l_cru_dev, vdev);
+	video_fmt = rzg2l_cru_ip_format_to_fmt(cru->format.pixelformat);
+
+	if (fmt.format.width != cru->format.width ||
+	    fmt.format.height != cru->format.height ||
+	    fmt.format.field != cru->format.field ||
+	    video_fmt->code != fmt.format.code)
+		return -EPIPE;
+
+	return 0;
+}
+
+static const struct media_entity_operations rzg2l_cru_video_media_ops = {
+	.link_validate = rzg2l_cru_video_link_validate,
+};
+
 static void rzg2l_cru_v4l2_init(struct rzg2l_cru_dev *cru)
 {
 	struct video_device *vdev = &cru->vdev;
@@ -997,6 +990,7 @@ static void rzg2l_cru_v4l2_init(struct rzg2l_cru_dev *cru)
 	vdev->lock = &cru->lock;
 	vdev->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
 	vdev->device_caps |= V4L2_CAP_IO_MC;
+	vdev->entity.ops = &rzg2l_cru_video_media_ops;
 	vdev->fops = &rzg2l_cru_fops;
 	vdev->ioctl_ops = &rzg2l_cru_ioctl_ops;