[RFC] media: imx: queue subdevice events on the video device in the same pipeline

[Philipp Zabel]

While subdevice and video device are in the same pipeline, pass
subdevice events on to userspace via the video device node.

Signed-off-by: Philipp Zabel <p.za...@pengutronix.de>
---
This would allow to see source change events from the source subdevice
on the video device node, for example.
---
 drivers/staging/media/imx/imx-media-dev.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/staging/media/imx/imx-media-dev.c 
b/drivers/staging/media/imx/imx-media-dev.c
index 4b344a4a3706..2fe6fdf2faf1 100644
--- a/drivers/staging/media/imx/imx-media-dev.c
+++ b/drivers/staging/media/imx/imx-media-dev.c
@@ -442,6 +442,23 @@ static const struct media_device_ops imx_media_md_ops = {
        .link_notify = imx_media_link_notify,
 };
 
+static void imx_media_notify(struct v4l2_subdev *sd, unsigned int notification,
+                            void *arg)
+{
+       struct imx_media_dev *imxmd;
+       struct imx_media_video_dev *vdev;
+
+       imxmd = container_of(sd->v4l2_dev, struct imx_media_dev, v4l2_dev);
+       list_for_each_entry(vdev, &imxmd->vdev_list, list) {
+               if (sd->entity.pipe &&
+                   sd->entity.pipe == vdev->vfd->entity.pipe &&
+                   notification == V4L2_DEVICE_NOTIFY_EVENT) {
+                       v4l2_event_queue(vdev->vfd, arg);
+                       break;
+               }
+       }
+}
+
 static int imx_media_probe(struct platform_device *pdev)
 {
        struct device *dev = &pdev->dev;
@@ -464,6 +481,7 @@ static int imx_media_probe(struct platform_device *pdev)
        imxmd->v4l2_dev.mdev = &imxmd->md;
        strscpy(imxmd->v4l2_dev.name, "imx-media",
                sizeof(imxmd->v4l2_dev.name));
+       imxmd->v4l2_dev.notify = imx_media_notify;
 
        media_device_init(&imxmd->md);
 
-- 
2.19.1