[media] v4l: Make video_device inherit from media_entity

V4L2 devices are media entities. As such they need to inherit from
(include) the media_entity structure.

When registering/unregistering the device, the media entity is
automatically registered/unregistered. The entity is acquired on device
open and released on device close.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 45 insertions, 4 deletions

diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c
index abe04ef..e405b80 100644
--- a/drivers/media/video/v4l2-dev.c
+++ b/drivers/media/video/v4l2-dev.c
@@ -303,6 +303,9 @@ static int v4l2_mmap(struct file *filp, struct vm_area_struct *vm)
 static int v4l2_open(struct inode *inode, struct file *filp)
 {
 	struct video_device *vdev;
+#if defined(CONFIG_MEDIA_CONTROLLER)
+	struct media_entity *entity = NULL;
+#endif
 	int ret = 0;
 
 	/* Check if the video device is available */
@@ -316,6 +319,16 @@ static int v4l2_open(struct inode *inode, struct file *filp)
 	/* and increase the device refcount */
 	video_get(vdev);
 	mutex_unlock(&videodev_lock);
+#if defined(CONFIG_MEDIA_CONTROLLER)
+	if (vdev->v4l2_dev && vdev->v4l2_dev->mdev) {
+		entity = media_entity_get(&vdev->entity);
+		if (!entity) {
+			ret = -EBUSY;
+			video_put(vdev);
+			return ret;
+		}
+	}
+#endif
 	if (vdev->fops->open) {
 		if (vdev->lock && mutex_lock_interruptible(vdev->lock)) {
 			ret = -ERESTARTSYS;
@@ -331,8 +344,13 @@ static int v4l2_open(struct inode *inode, struct file *filp)
 
 err:
 	/* decrease the refcount in case of an error */
-	if (ret)
+	if (ret) {
+#if defined(CONFIG_MEDIA_CONTROLLER)
+		if (vdev->v4l2_dev && vdev->v4l2_dev->mdev)
+			media_entity_put(entity);
+#endif
 		video_put(vdev);
+	}
 	return ret;
 }
 
@@ -349,7 +367,10 @@ static int v4l2_release(struct inode *inode, struct file *filp)
 		if (vdev->lock)
 			mutex_unlock(vdev->lock);
 	}
-
+#if defined(CONFIG_MEDIA_CONTROLLER)
+	if (vdev->v4l2_dev && vdev->v4l2_dev->mdev)
+		media_entity_put(&vdev->entity);
+#endif
 	/* decrease the refcount unconditionally since the release()
 	   return value is ignored. */
 	video_put(vdev);
@@ -585,12 +606,27 @@ int __video_register_device(struct video_device *vdev, int type, int nr,
 	if (nr != -1 && nr != vdev->num && warn_if_nr_in_use)
 		printk(KERN_WARNING "%s: requested %s%d, got %s\n", __func__,
 			name_base, nr, video_device_node_name(vdev));
-
-	/* Part 5: Activate this minor. The char device can now be used. */
+#if defined(CONFIG_MEDIA_CONTROLLER)
+	/* Part 5: Register the entity. */
+	if (vdev->v4l2_dev && vdev->v4l2_dev->mdev) {
+		vdev->entity.type = MEDIA_ENT_T_DEVNODE_V4L;
+		vdev->entity.name = vdev->name;
+		vdev->entity.v4l.major = VIDEO_MAJOR;
+		vdev->entity.v4l.minor = vdev->minor;
+		ret = media_device_register_entity(vdev->v4l2_dev->mdev,
+			&vdev->entity);
+		if (ret < 0)
+			printk(KERN_WARNING
+			       "%s: media_device_register_entity failed\n",
+			       __func__);
+	}
+#endif
+	/* Part 6: Activate this minor. The char device can now be used. */
 	set_bit(V4L2_FL_REGISTERED, &vdev->flags);
 	mutex_lock(&videodev_lock);
 	video_device[vdev->minor] = vdev;
 	mutex_unlock(&videodev_lock);
+
 	return 0;
 
 cleanup:
@@ -618,6 +654,11 @@ void video_unregister_device(struct video_device *vdev)
 	if (!vdev || !video_is_registered(vdev))
 		return;
 
+#if defined(CONFIG_MEDIA_CONTROLLER)
+	if (vdev->v4l2_dev && vdev->v4l2_dev->mdev)
+		media_device_unregister_entity(&vdev->entity);
+#endif
+
 	mutex_lock(&videodev_lock);
 	/* This must be in a critical section to prevent a race with v4l2_open.
 	 * Once this bit has been cleared video_get may never be called again.