[PATCH v3 30/31] rcar-csi2: expose the subdevice internal routing

[Jacopo Mondi]

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

Expose the subdevice internal routing from the single multiplexed sink
pad to its source pads by implementing .get_routing(). This information
is used to do link validation at stream start and allows user-space to
view the route configuration.

Signed-off-by: Niklas Söderlund <niklas.soderlund+rene...@ragnatech.se>
Signed-off-by: Jacopo Mondi <jacopo+rene...@jmondi.org>
---
 drivers/media/platform/rcar-vin/rcar-csi2.c | 53 +++++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/drivers/media/platform/rcar-vin/rcar-csi2.c 
b/drivers/media/platform/rcar-vin/rcar-csi2.c
index f9cc99ba00bc..cc7077b40f18 100644
--- a/drivers/media/platform/rcar-vin/rcar-csi2.c
+++ b/drivers/media/platform/rcar-vin/rcar-csi2.c
@@ -341,6 +341,14 @@ static int rcsi2_pad_to_vc(unsigned int pad)
        return pad - RCAR_CSI2_SOURCE_VC0;
 }
 
+static int rcsi2_vc_to_pad(unsigned int vc)
+{
+       if (vc > 3)
+               return -EINVAL;
+
+       return vc + RCAR_CSI2_SOURCE_VC0;
+}
+
 struct rcar_csi2_info {
        int (*init_phtw)(struct rcar_csi2 *priv, unsigned int mbps);
        int (*confirm_start)(struct rcar_csi2 *priv);
@@ -705,9 +713,54 @@ static const struct v4l2_subdev_video_ops 
rcar_csi2_video_ops = {
        .s_stream = rcsi2_s_stream,
 };
 
+static int rcsi2_get_routing(struct v4l2_subdev *sd,
+                            struct v4l2_subdev_krouting *routing)
+{
+       struct v4l2_subdev_route *r = routing->routes;
+       struct rcar_csi2 *priv = sd_to_csi2(sd);
+       struct v4l2_mbus_frame_desc fd;
+       unsigned int i;
+       int ret;
+
+       /* Get information about multiplexed link */
+       ret = rcsi2_get_remote_frame_desc(priv, &fd);
+       if (ret)
+               return ret;
+
+       if (routing->num_routes < fd.num_entries) {
+               routing->num_routes = fd.num_entries;
+               return -ENOSPC;
+       }
+
+       routing->num_routes = fd.num_entries;
+
+       for (i = 0; i < fd.num_entries; i++) {
+               struct v4l2_mbus_frame_desc_entry *entry = &fd.entry[i];
+               int source_pad;
+
+               source_pad = rcsi2_vc_to_pad(entry->bus.csi2.channel);
+               if (source_pad < 0) {
+                       dev_err(priv->dev, "Virtual Channel out of range: %u\n",
+                               entry->bus.csi2.channel);
+                       return -EINVAL;
+               }
+
+               r->sink_pad = RCAR_CSI2_SINK;
+               r->sink_stream = entry->stream;
+               r->source_pad = source_pad;
+               r->source_stream = 0;
+               r->flags = V4L2_SUBDEV_ROUTE_FL_ACTIVE |
+                          V4L2_SUBDEV_ROUTE_FL_IMMUTABLE;
+               r++;
+       }
+
+       return 0;
+}
+
 static const struct v4l2_subdev_pad_ops rcar_csi2_pad_ops = {
        .set_fmt = rcsi2_set_pad_format,
        .get_fmt = rcsi2_get_pad_format,
+       .get_routing = rcsi2_get_routing,
 };
 
 static const struct v4l2_subdev_ops rcar_csi2_subdev_ops = {
-- 
2.20.1