[PATCH 10/20] rcar-csi2: count usage for each source pad

[Niklas Söderlund]

The R-Car CSI-2 hardware can output the same virtual channel
simultaneously to more then one R-Car VIN. For this reason we need to
move the usage counting from the global device to each source pad.

If a source pads usage count go from 0 to 1 we need to signal that a new
stream should start, likewise if it go from 1 to 0 we need to stop a
stream. At the same time we don't want to start or stop the whole R-Car
CSI-2 device but at the first or last stream is started.

Signed-off-by: Niklas Söderlund <niklas.soderlund+rene...@ragnatech.se>
---
 drivers/media/platform/rcar-vin/rcar-csi2.c | 27 ++++++++++++++++++---------
 1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/drivers/media/platform/rcar-vin/rcar-csi2.c 
b/drivers/media/platform/rcar-vin/rcar-csi2.c
index 8b4db70b0dd5d0fb..12a8ea7a219ac7d3 100644
--- a/drivers/media/platform/rcar-vin/rcar-csi2.c
+++ b/drivers/media/platform/rcar-vin/rcar-csi2.c
@@ -294,7 +294,7 @@ struct rcar_csi2 {
        struct v4l2_mbus_framefmt mf;
 
        struct mutex lock;
-       int stream_count;
+       int stream_count[4];
 
        struct {
                struct v4l2_async_subdev asd;
@@ -582,7 +582,7 @@ static int rcar_csi2_s_stream(struct v4l2_subdev *sd, 
unsigned int pad,
                              unsigned int stream, int enable)
 {
        struct rcar_csi2 *priv = sd_to_csi2(sd);
-       unsigned int channel, nextpad, nextstream;
+       unsigned int i, channel, nextpad, nextstream, count = 0;
        struct v4l2_subdev *nextsd;
        int ret;
 
@@ -601,18 +601,25 @@ static int rcar_csi2_s_stream(struct v4l2_subdev *sd, 
unsigned int pad,
        if (ret)
                goto out;
 
-       priv->stream_count += enable ? 1 : -1;
+       priv->stream_count[channel] += enable ? 1 : -1;
 
-       if (enable && priv->stream_count == 1) {
+       for (i = 0; i < 4; i++)
+               count += priv->stream_count[i];
+
+       if (enable && count == 1) {
                ret =  rcar_csi2_start(priv);
                if (ret)
                        goto out;
-               ret = v4l2_subdev_call(nextsd, video, s_stream, 1);
-
-       } else if (!enable && !priv->stream_count) {
+       } else if (!enable && !count) {
                rcar_csi2_stop(priv);
-               ret = v4l2_subdev_call(nextsd, video, s_stream, 0);
        }
+
+       if (enable && priv->stream_count[channel] == 1)
+               ret = v4l2_subdev_call(nextsd, pad, s_stream, nextpad,
+                                      nextstream, 1);
+       else if (!enable && !priv->stream_count[channel])
+               ret = v4l2_subdev_call(nextsd, pad, s_stream, nextpad,
+                                      nextstream, 0);
 out:
        mutex_unlock(&priv->lock);
 
@@ -912,7 +919,9 @@ static int rcar_csi2_probe(struct platform_device *pdev)
        priv->dev = &pdev->dev;
 
        mutex_init(&priv->lock);
-       priv->stream_count = 0;
+
+       for (i = 0; i < 4; i++)
+               priv->stream_count[i] = 0;
 
        ret = rcar_csi2_parse_dt_settings(priv);
        if (ret)
-- 
2.13.3