[PATCH v3 3/6] media: synopsys: csi2rx: implement .get_frame_desc() callback

[Frank Li <Frank.Li@nxp.com>]

Implement the .get_frame_desc() callback to fetch information from the
remote endpoint.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
change in v3
- use media_entity_to_v4l2_subdev()

change in v2
- add csi2rx in subject
---
 drivers/media/platform/synopsys/dw-mipi-csi2rx.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/media/platform/synopsys/dw-mipi-csi2rx.c b/drivers/media/platform/synopsys/dw-mipi-csi2rx.c
index f03fe01280013bf9a832433c6b06dab691bf8f4c..bcbf109a0bfd040c568c0652e28752c94a1bc30d 100644
--- a/drivers/media/platform/synopsys/dw-mipi-csi2rx.c
+++ b/drivers/media/platform/synopsys/dw-mipi-csi2rx.c
@@ -429,10 +429,31 @@ static int dw_mipi_csi2rx_disable_streams(struct v4l2_subdev *sd,
 	return ret;
 }
 
+static int
+dw_mipi_csi2rx_get_frame_desc(struct v4l2_subdev *sd, unsigned int pad,
+			      struct v4l2_mbus_frame_desc *fd)
+{
+	struct dw_mipi_csi2rx_device *csi2 = to_csi2(sd);
+	struct v4l2_subdev *remote_sd;
+	struct media_pad *remote_pad;
+
+	remote_pad = media_pad_remote_pad_unique(&csi2->pads[DW_MIPI_CSI2RX_PAD_SINK]);
+	if (IS_ERR(remote_pad)) {
+		dev_err(csi2->dev, "can't get remote source pad\n");
+		return PTR_ERR(remote_pad);
+	}
+
+	remote_sd = media_entity_to_v4l2_subdev(remote_pad->entity);
+
+	return v4l2_subdev_call(remote_sd, pad, get_frame_desc,
+				remote_pad->index, fd);
+}
+
 static const struct v4l2_subdev_pad_ops dw_mipi_csi2rx_pad_ops = {
 	.enum_mbus_code = dw_mipi_csi2rx_enum_mbus_code,
 	.get_fmt = v4l2_subdev_get_fmt,
 	.set_fmt = dw_mipi_csi2rx_set_fmt,
+	.get_frame_desc = dw_mipi_csi2rx_get_frame_desc,
 	.set_routing = dw_mipi_csi2rx_set_routing,
 	.enable_streams = dw_mipi_csi2rx_enable_streams,
 	.disable_streams = dw_mipi_csi2rx_disable_streams,

-- 
2.43.0