[PATCH RFC 14/21] media: cadence: csi2rx: Enable stream-wise routing

[Jai Luthra <j-luthra@ti.com>]

Cadence CSI-2 bridge IP supports capturing multiple virtual "streams"
of data over the same physical interface using MIPI Virtual Channels.

The V4L2 subdev APIs should reflect this capability and allow per-stream
routing and controls.

While the hardware IP supports usecases where streams coming in the sink
pad can be broadcasted to multiple source pads, the driver will need
significant re-architecture to make that possible. The two users of this
IP in mainline linux are TI Shim and StarFive JH7110 CAMSS, and both
have only integrated the first source pad i.e stream0 of this IP. So for
now keep it simple and only allow 1-to-1 mapping of streams from sink to
source, without any broadcasting.

This commit only adds support for subdev routing APIs, without actually
setting the registers in the Cadence IP to filter for particular virtual
channels. Subsequent commits will add that support.

Signed-off-by: Jai Luthra <j-luthra@ti.com>
---
 drivers/media/platform/cadence/cdns-csi2rx.c | 91 ++++++++++++++++++++++------
 1 file changed, 71 insertions(+), 20 deletions(-)

diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
index bac341881e41..1b76610ff617 100644
--- a/drivers/media/platform/cadence/cdns-csi2rx.c
+++ b/drivers/media/platform/cadence/cdns-csi2rx.c
@@ -450,12 +450,55 @@ static int csi2rx_enum_mbus_code(struct v4l2_subdev *subdev,
 	return 0;
 }
 
+static int _csi2rx_set_routing(struct v4l2_subdev *subdev,
+			       struct v4l2_subdev_state *state,
+			       struct v4l2_subdev_krouting *routing)
+{
+	static const struct v4l2_mbus_framefmt format = {
+		.width = 640,
+		.height = 480,
+		.code = MEDIA_BUS_FMT_UYVY8_1X16,
+		.field = V4L2_FIELD_NONE,
+		.colorspace = V4L2_COLORSPACE_SRGB,
+		.ycbcr_enc = V4L2_YCBCR_ENC_601,
+		.quantization = V4L2_QUANTIZATION_LIM_RANGE,
+		.xfer_func = V4L2_XFER_FUNC_SRGB,
+	};
+	int ret;
+
+	if (routing->num_routes > V4L2_FRAME_DESC_ENTRY_MAX)
+		return -EINVAL;
+
+	ret = v4l2_subdev_routing_validate(subdev, routing,
+					   V4L2_SUBDEV_ROUTING_ONLY_1_TO_1);
+	if (ret)
+		return ret;
+
+	ret = v4l2_subdev_set_routing_with_fmt(subdev, state, routing, &format);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int csi2rx_set_routing(struct v4l2_subdev *subdev,
+			      struct v4l2_subdev_state *state,
+			      enum v4l2_subdev_format_whence which,
+			      struct v4l2_subdev_krouting *routing)
+{
+	struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
+
+	if (which == V4L2_SUBDEV_FORMAT_ACTIVE && csi2rx->count)
+		return -EBUSY;
+
+	return _csi2rx_set_routing(subdev, state, routing);
+}
+
 static int csi2rx_set_fmt(struct v4l2_subdev *subdev,
 			  struct v4l2_subdev_state *state,
 			  struct v4l2_subdev_format *format)
 {
 	struct v4l2_mbus_framefmt *fmt;
-	unsigned int i;
 
 	/* No transcoding, source and sink formats must match. */
 	if (format->pad != CSI2RX_PAD_SINK)
@@ -467,14 +510,19 @@ static int csi2rx_set_fmt(struct v4l2_subdev *subdev,
 	format->format.field = V4L2_FIELD_NONE;
 
 	/* Set sink format */
-	fmt = v4l2_subdev_state_get_format(state, format->pad);
+	fmt = v4l2_subdev_state_get_format(state, format->pad, format->stream);
+	if (!fmt)
+		return -EINVAL;
+
 	*fmt = format->format;
 
-	/* Propagate to source formats */
-	for (i = CSI2RX_PAD_SOURCE_STREAM0; i < CSI2RX_PAD_MAX; i++) {
-		fmt = v4l2_subdev_state_get_format(state, i);
-		*fmt = format->format;
-	}
+	/* Propagate to source format */
+	fmt = v4l2_subdev_state_get_opposite_stream_format(state, format->pad,
+							   format->stream);
+	if (!fmt)
+		return -EINVAL;
+
+	*fmt = format->format;
 
 	return 0;
 }
@@ -482,21 +530,22 @@ static int csi2rx_set_fmt(struct v4l2_subdev *subdev,
 static int csi2rx_init_state(struct v4l2_subdev *subdev,
 			     struct v4l2_subdev_state *state)
 {
-	struct v4l2_subdev_format format = {
-		.pad = CSI2RX_PAD_SINK,
-		.format = {
-			.width = 640,
-			.height = 480,
-			.code = MEDIA_BUS_FMT_UYVY8_1X16,
-			.field = V4L2_FIELD_NONE,
-			.colorspace = V4L2_COLORSPACE_SRGB,
-			.ycbcr_enc = V4L2_YCBCR_ENC_601,
-			.quantization = V4L2_QUANTIZATION_LIM_RANGE,
-			.xfer_func = V4L2_XFER_FUNC_SRGB,
+	struct v4l2_subdev_route routes[] = {
+		{
+			.sink_pad = CSI2RX_PAD_SINK,
+			.sink_stream = 0,
+			.source_pad = CSI2RX_PAD_SOURCE_STREAM0,
+			.source_stream = 0,
+			.flags = V4L2_SUBDEV_ROUTE_FL_ACTIVE,
 		},
 	};
 
-	return csi2rx_set_fmt(subdev, state, &format);
+	struct v4l2_subdev_krouting routing = {
+		.num_routes = ARRAY_SIZE(routes),
+		.routes = routes,
+	};
+
+	return _csi2rx_set_routing(subdev, state, &routing);
 }
 
 static int csi2rx_get_frame_desc(struct v4l2_subdev *subdev, unsigned int pad,
@@ -512,6 +561,7 @@ static const struct v4l2_subdev_pad_ops csi2rx_pad_ops = {
 	.get_fmt	= v4l2_subdev_get_fmt,
 	.set_fmt	= csi2rx_set_fmt,
 	.get_frame_desc = csi2rx_get_frame_desc,
+	.set_routing	= csi2rx_set_routing,
 };
 
 static const struct v4l2_subdev_video_ops csi2rx_video_ops = {
@@ -770,7 +820,8 @@ static int csi2rx_probe(struct platform_device *pdev)
 	csi2rx->pads[CSI2RX_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
 	for (i = CSI2RX_PAD_SOURCE_STREAM0; i < CSI2RX_PAD_MAX; i++)
 		csi2rx->pads[i].flags = MEDIA_PAD_FL_SOURCE;
-	csi2rx->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+	csi2rx->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE |
+		V4L2_SUBDEV_FL_STREAMS;
 	csi2rx->subdev.entity.ops = &csi2rx_media_ops;
 
 	ret = media_entity_pads_init(&csi2rx->subdev.entity, CSI2RX_PAD_MAX,

-- 
2.43.0