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

Implement the .get_frame_desc() subdev operation to report information
about streams to the connected CSI-2 receiver. This is required to let
the CSI-2 receiver driver know about virtual channels and data types for
each stream.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
---
Changes since v3 [0],
- Added a macro for the source pad index.
- Updated ov5645_init_state() to use the new macro.

[0] https://lore.kernel.org/all/20241018153230.235647-9-prabhakar.mahadev-lad.rj@bp.renesas.com/

Hi Laurent,

Ive restored your RB tag with the above changes. Please let me know if
you have any further comments.
Cheers,
Prabhakar
---
 drivers/media/i2c/ov5645.c | 29 ++++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/drivers/media/i2c/ov5645.c b/drivers/media/i2c/ov5645.c
index b10d408034a1..df9001fce44d 100644
--- a/drivers/media/i2c/ov5645.c
+++ b/drivers/media/i2c/ov5645.c
@@ -28,6 +28,7 @@
 #include <linux/regulator/consumer.h>
 #include <linux/slab.h>
 #include <linux/types.h>
+#include <media/mipi-csi2.h>
 #include <media/v4l2-ctrls.h>
 #include <media/v4l2-fwnode.h>
 #include <media/v4l2-subdev.h>
@@ -68,6 +69,8 @@ static const char * const ov5645_supply_name[] = {
 
 #define OV5645_NUM_SUPPLIES ARRAY_SIZE(ov5645_supply_name)
 
+#define OV5645_PAD_SOURCE	0
+
 struct reg_value {
 	u16 reg;
 	u8 val;
@@ -817,6 +820,29 @@ static const struct v4l2_ctrl_ops ov5645_ctrl_ops = {
 	.s_ctrl = ov5645_s_ctrl,
 };
 
+static int ov5645_get_frame_desc(struct v4l2_subdev *sd, unsigned int pad,
+				 struct v4l2_mbus_frame_desc *fd)
+{
+	struct v4l2_subdev_state *state;
+	u32 code;
+
+	state = v4l2_subdev_lock_and_get_active_state(sd);
+	code = v4l2_subdev_state_get_format(state, OV5645_PAD_SOURCE, 0)->code;
+	v4l2_subdev_unlock_state(state);
+
+	fd->type = V4L2_MBUS_FRAME_DESC_TYPE_CSI2;
+	fd->num_entries = 1;
+
+	memset(fd->entry, 0, sizeof(fd->entry));
+
+	fd->entry[0].pixelcode = code;
+	fd->entry[0].stream = 0;
+	fd->entry[0].bus.csi2.vc = 0;
+	fd->entry[0].bus.csi2.dt = MIPI_CSI2_DT_YUV422_8B;
+
+	return 0;
+}
+
 static int ov5645_enum_mbus_code(struct v4l2_subdev *sd,
 				 struct v4l2_subdev_state *sd_state,
 				 struct v4l2_subdev_mbus_code_enum *code)
@@ -897,7 +923,7 @@ static int ov5645_init_state(struct v4l2_subdev *subdev,
 {
 	struct v4l2_subdev_format fmt = {
 		.which = V4L2_SUBDEV_FORMAT_TRY,
-		.pad = 0,
+		.pad = OV5645_PAD_SOURCE,
 		.format = {
 			.code = MEDIA_BUS_FMT_UYVY8_1X16,
 			.width = ov5645_mode_info_data[1].width,
@@ -988,6 +1014,7 @@ static const struct v4l2_subdev_video_ops ov5645_video_ops = {
 };
 
 static const struct v4l2_subdev_pad_ops ov5645_subdev_pad_ops = {
+	.get_frame_desc = ov5645_get_frame_desc,
 	.enum_mbus_code = ov5645_enum_mbus_code,
 	.enum_frame_size = ov5645_enum_frame_size,
 	.get_fmt = v4l2_subdev_get_fmt,
-- 
2.53.0