[PATCH v3 25/31] adv748x: csi2: describe the multiplexed stream

[Jacopo Mondi <jacopo+renesas@jmondi.org>]

From: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>

The adv748x CSI-2 transmitter can only transmit one stream over the
CSI-2 link, however it can choose which virtual channel is used. This
choice effects the CSI-2 receiver and needs to be captured in the frame
descriptor information, solve this by implementing .get_frame_desc().

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
---
 drivers/media/i2c/adv748x/adv748x-csi2.c | 31 +++++++++++++++++++++++-
 drivers/media/i2c/adv748x/adv748x.h      |  1 +
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/drivers/media/i2c/adv748x/adv748x-csi2.c b/drivers/media/i2c/adv748x/adv748x-csi2.c
index 1abe34183d7d..d8f7cbee86e7 100644
--- a/drivers/media/i2c/adv748x/adv748x-csi2.c
+++ b/drivers/media/i2c/adv748x/adv748x-csi2.c
@@ -226,9 +226,37 @@ static int adv748x_csi2_set_format(struct v4l2_subdev *sd,
 	return ret;
 }
 
+static int adv748x_csi2_get_frame_desc(struct v4l2_subdev *sd, unsigned int pad,
+				       struct v4l2_mbus_frame_desc *fd)
+{
+	struct adv748x_csi2 *tx = adv748x_sd_to_csi2(sd);
+	struct v4l2_mbus_framefmt *mbusformat;
+
+	memset(fd, 0, sizeof(*fd));
+
+	if (pad != ADV748X_CSI2_SOURCE)
+		return -EINVAL;
+
+	mbusformat = adv748x_csi2_get_pad_format(sd, NULL, ADV748X_CSI2_SINK,
+						 V4L2_SUBDEV_FORMAT_ACTIVE);
+	if (!mbusformat)
+		return -EINVAL;
+
+	fd->entry->stream = tx->vc;
+	fd->entry->bus.csi2.channel = tx->vc;
+	fd->entry->bus.csi2.data_type =
+		adv748x_csi2_code_to_datatype(mbusformat->code);
+
+	fd->type = V4L2_MBUS_FRAME_DESC_TYPE_CSI2;
+	fd->num_entries = 1;
+
+	return 0;
+}
+
 static const struct v4l2_subdev_pad_ops adv748x_csi2_pad_ops = {
 	.get_fmt = adv748x_csi2_get_format,
 	.set_fmt = adv748x_csi2_set_format,
+	.get_frame_desc = adv748x_csi2_get_frame_desc,
 };
 
 /* -----------------------------------------------------------------------------
@@ -295,7 +323,8 @@ int adv748x_csi2_init(struct adv748x_state *state, struct adv748x_csi2 *tx)
 		return 0;
 
 	/* Initialise the virtual channel */
-	adv748x_csi2_set_virtual_channel(tx, 0);
+	tx->vc = 0;
+	adv748x_csi2_set_virtual_channel(tx, tx->vc);
 
 	adv748x_subdev_init(&tx->sd, state, &adv748x_csi2_ops,
 			    MEDIA_ENT_F_VID_IF_BRIDGE,
diff --git a/drivers/media/i2c/adv748x/adv748x.h b/drivers/media/i2c/adv748x/adv748x.h
index 5042f9e94aee..4a5a6445604f 100644
--- a/drivers/media/i2c/adv748x/adv748x.h
+++ b/drivers/media/i2c/adv748x/adv748x.h
@@ -75,6 +75,7 @@ enum adv748x_csi2_pads {
 
 struct adv748x_csi2 {
 	struct adv748x_state *state;
+	unsigned int vc;
 	struct v4l2_mbus_framefmt format;
 	unsigned int page;
 	unsigned int port;
-- 
2.20.1