From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

The RZ/G2L CRU requires information about which VCx to process data from,
among the four available VCs. To obtain this information, the
.get_frame_desc() routine is implemented. This routine, in turn, calls
.get_frame_desc() on the remote sensor connected to the CSI2 bridge.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 .../platform/renesas/rzg2l-cru/rzg2l-csi2.c   | 20 +++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c
index 5d1050e685c6..dee8c1a749c7 100644
--- a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c
+++ b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c
@@ -582,6 +582,25 @@ static int rzg2l_csi2_enum_frame_size(struct v4l2_subdev *sd,
 	return 0;
 }
 
+static int rzg2l_csi2_get_frame_desc(struct v4l2_subdev *sd, unsigned int pad,
+				     struct v4l2_mbus_frame_desc *fd)
+{
+	struct rzg2l_csi2 *csi2 = sd_to_csi2(sd);
+	struct media_pad *remote_pad;
+
+	if (!csi2->remote_source)
+		return -ENODEV;
+
+	remote_pad = media_pad_remote_pad_unique(&csi2->pads[RZG2L_CSI2_SINK]);
+	if (IS_ERR(remote_pad)) {
+		dev_err(csi2->dev, "can't get source pad of %s (%ld)\n",
+			csi2->remote_source->name, PTR_ERR(remote_pad));
+		return PTR_ERR(remote_pad);
+	}
+	return v4l2_subdev_call(csi2->remote_source, pad, get_frame_desc,
+				remote_pad->index, fd);
+}
+
 static const struct v4l2_subdev_video_ops rzg2l_csi2_video_ops = {
 	.s_stream = rzg2l_csi2_s_stream,
 	.pre_streamon = rzg2l_csi2_pre_streamon,
@@ -593,6 +612,7 @@ static const struct v4l2_subdev_pad_ops rzg2l_csi2_pad_ops = {
 	.enum_frame_size = rzg2l_csi2_enum_frame_size,
 	.set_fmt = rzg2l_csi2_set_format,
 	.get_fmt = v4l2_subdev_get_fmt,
+	.get_frame_desc = rzg2l_csi2_get_frame_desc,
 };
 
 static const struct v4l2_subdev_ops rzg2l_csi2_subdev_ops = {
-- 
2.43.0