1 files changed, 32 insertions, 15 deletions

diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h
index a0a6b41c5e09..e0d72d2c6f0e 100644
--- a/include/media/v4l2-dev.h
+++ b/include/media/v4l2-dev.h
@@ -26,6 +26,11 @@
 
 struct v4l2_ioctl_callbacks;
 
+/* Flag to mark the video_device struct as unregistered.
+   Drivers can set this flag if they want to block all future
+   device access. It is set by video_unregister_device. */
+#define V4L2_FL_UNREGISTERED    (0)
+
 /*
  * Newer version of video_device, handled by videodev2.c
  *      This version moves redundant code from video device code to
@@ -39,15 +44,17 @@ struct video_device
 
         /* sysfs */
         struct device dev;              /* v4l device */
-        struct cdev cdev;               /* character device */
-        void (*cdev_release)(struct kobject *kobj);
+        struct cdev *cdev;              /* character device */
         struct device *parent;          /* device parent */
 
         /* device info */
         char name[32];
         int vfl_type;
+        /* 'minor' is set to -1 if the registration failed */
         int minor;
         u16 num;
+        /* use bitops to set/clear/test flags */
+        unsigned long flags;
         /* attribute to differentiate multiple indices on one physical device */
         int index;
 
@@ -58,7 +65,7 @@ struct video_device
         v4l2_std_id current_norm;       /* Current tvnorm */
 
         /* callbacks */
-        void (*release)(struct video_device *vfd);
+        void (*release)(struct video_device *vdev);
 
         /* ioctl callbacks */
         const struct v4l2_ioctl_ops *ioctl_ops;
@@ -67,36 +74,41 @@ struct video_device
 /* dev to video-device */
 #define to_video_device(cd) container_of(cd, struct video_device, dev)
 
-/* Register and unregister devices. Note that if video_register_device fails,
+/* Register video devices. Note that if video_register_device fails,
    the release() callback of the video_device structure is *not* called, so
    the caller is responsible for freeing any data. Usually that means that
-   you call video_device_release() on failure. */
-int __must_check video_register_device(struct video_device *vfd, int type, int nr);
-int __must_check video_register_device_index(struct video_device *vfd,
+   you call video_device_release() on failure.
+
+   Also note that vdev->minor is set to -1 if the registration failed. */
+int __must_check video_register_device(struct video_device *vdev, int type, int nr);
+int __must_check video_register_device_index(struct video_device *vdev,
                                                 int type, int nr, int index);
-void video_unregister_device(struct video_device *vfd);
+
+/* Unregister video devices. Will do nothing if vdev == NULL or
+   vdev->minor < 0. */
+void video_unregister_device(struct video_device *vdev);
 
 /* helper functions to alloc/release struct video_device, the
    latter can also be used for video_device->release(). */
 struct video_device * __must_check video_device_alloc(void);
 
-/* this release function frees the vfd pointer */
-void video_device_release(struct video_device *vfd);
+/* this release function frees the vdev pointer */
+void video_device_release(struct video_device *vdev);
 
 /* this release function does nothing, use when the video_device is a
    static global struct. Note that having a static video_device is
    a dubious construction at best. */
-void video_device_release_empty(struct video_device *vfd);
+void video_device_release_empty(struct video_device *vdev);
 
 /* helper functions to access driver private data. */
-static inline void *video_get_drvdata(struct video_device *dev)
+static inline void *video_get_drvdata(struct video_device *vdev)
 {
-        return dev_get_drvdata(&dev->dev);
+        return dev_get_drvdata(&vdev->dev);
 }
 
-static inline void video_set_drvdata(struct video_device *dev, void *data)
+static inline void video_set_drvdata(struct video_device *vdev, void *data)
 {
-        dev_set_drvdata(&dev->dev, data);
+        dev_set_drvdata(&vdev->dev, data);
 }
 
 struct video_device *video_devdata(struct file *file);
@@ -108,4 +120,9 @@ static inline void *video_drvdata(struct file *file)
         return video_get_drvdata(video_devdata(file));
 }
 
+static inline int video_is_unregistered(struct video_device *vdev)
+{
+        return test_bit(V4L2_FL_UNREGISTERED, &vdev->flags);
+}
+
 #endif /* _V4L2_DEV_H */