[PATCH] media: imx: queue subdev events to reachable video devices

[Steve Longerbeam]

From: Steve Longerbeam <slongerbeam@xxxxxxxxx>

Forward events from a sub-device to its list of reachable video
devices.

Note this will queue the event to a video device even if there is
no actual _enabled_ media path from the sub-device to the video device.
So a future improvement is to skip the video device if there is no enabled
path to it from the sub-device. The entity->pipe pointer can't be
used for this check because in imx-media a sub-device can be a
member to more than one streaming pipeline at a time.

Signed-off-by: Steve Longerbeam <slongerbeam@xxxxxxxxx>
---
 drivers/staging/media/imx/imx-media-capture.c | 18 ++++++++++++++
 drivers/staging/media/imx/imx-media-dev.c     | 24 +++++++++++++++++++
 2 files changed, 42 insertions(+)

diff --git a/drivers/staging/media/imx/imx-media-capture.c b/drivers/staging/media/imx/imx-media-capture.c
index b37e1186eb2f..4dfbe05d203e 100644
--- a/drivers/staging/media/imx/imx-media-capture.c
+++ b/drivers/staging/media/imx/imx-media-capture.c
@@ -335,6 +335,21 @@ static int capture_s_parm(struct file *file, void *fh,
 	return 0;
 }
 
+static int capture_subscribe_event(struct v4l2_fh *fh,
+				   const struct v4l2_event_subscription *sub)
+{
+	switch (sub->type) {
+	case V4L2_EVENT_IMX_FRAME_INTERVAL_ERROR:
+		return v4l2_event_subscribe(fh, sub, 0, NULL);
+	case V4L2_EVENT_SOURCE_CHANGE:
+		return v4l2_src_change_event_subscribe(fh, sub);
+	case V4L2_EVENT_CTRL:
+		return v4l2_ctrl_subscribe_event(fh, sub);
+	default:
+		return -EINVAL;
+	}
+}
+
 static const struct v4l2_ioctl_ops capture_ioctl_ops = {
 	.vidioc_querycap	= vidioc_querycap,
 
@@ -362,6 +377,9 @@ static const struct v4l2_ioctl_ops capture_ioctl_ops = {
 	.vidioc_expbuf		= vb2_ioctl_expbuf,
 	.vidioc_streamon	= vb2_ioctl_streamon,
 	.vidioc_streamoff	= vb2_ioctl_streamoff,
+
+	.vidioc_subscribe_event = capture_subscribe_event,
+	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
 };
 
 /*
diff --git a/drivers/staging/media/imx/imx-media-dev.c b/drivers/staging/media/imx/imx-media-dev.c
index 4b344a4a3706..25e916562c66 100644
--- a/drivers/staging/media/imx/imx-media-dev.c
+++ b/drivers/staging/media/imx/imx-media-dev.c
@@ -442,6 +442,29 @@ 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 media_entity *entity = &sd->entity;
+	int i;
+
+	if (notification != V4L2_DEVICE_NOTIFY_EVENT)
+		return;
+
+	for (i = 0; i < entity->num_pads; i++) {
+		struct media_pad *pad = &entity->pads[i];
+		struct imx_media_pad_vdev *pad_vdev;
+		struct list_head *pad_vdev_list;
+
+		pad_vdev_list = to_pad_vdev_list(sd, pad->index);
+		if (!pad_vdev_list)
+			continue;
+		list_for_each_entry(pad_vdev, pad_vdev_list, list)
+			v4l2_event_queue(pad_vdev->vdev->vfd, arg);
+	}
+}
+
 static int imx_media_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -462,6 +485,7 @@ static int imx_media_probe(struct platform_device *pdev)
 	mutex_init(&imxmd->mutex);
 
 	imxmd->v4l2_dev.mdev = &imxmd->md;
+	imxmd->v4l2_dev.notify = imx_media_notify;
 	strscpy(imxmd->v4l2_dev.name, "imx-media",
 		sizeof(imxmd->v4l2_dev.name));
 
-- 
2.17.1