1 files changed, 27 insertions, 5 deletions

diff --git a/include/media/media-devnode.h b/include/media/media-devnode.h
index 17ddae32060d..d5ff95bf2d4b 100644
--- a/include/media/media-devnode.h
+++ b/include/media/media-devnode.h
@@ -33,6 +33,8 @@
 #include <linux/device.h>
 #include <linux/cdev.h>
 
+struct media_device;
+
 /*
  * Flag to mark the media_devnode struct as registered. Drivers must not touch
  * this flag directly, it will be set and cleared by media_devnode_register and
@@ -67,6 +69,8 @@ struct media_file_operations {
  * before registering the node.
  */
 struct media_devnode {
+	struct media_device *media_dev;
+
 	/* device ops */
 	const struct media_file_operations *fops;
 
@@ -80,24 +84,42 @@ struct media_devnode {
 	unsigned long flags;		/* Use bitops to access flags */
 
 	/* callbacks */
-	void (*release)(struct media_devnode *mdev);
+	void (*release)(struct media_devnode *devnode);
 };
 
 /* dev to media_devnode */
 #define to_media_devnode(cd) container_of(cd, struct media_devnode, dev)
 
-int __must_check media_devnode_register(struct media_devnode *mdev,
+int __must_check media_devnode_register(struct media_device *mdev,
+					struct media_devnode *devnode,
 					struct module *owner);
-void media_devnode_unregister(struct media_devnode *mdev);
+
+/**
+ * media_devnode_unregister_prepare - clear the media device node register bit
+ * @devnode: the device node to prepare for unregister
+ *
+ * This clears the passed device register bit. Future open calls will be met
+ * with errors. Should be called before media_devnode_unregister() to avoid
+ * races with unregister and device file open calls.
+ *
+ * This function can safely be called if the device node has never been
+ * registered or has already been unregistered.
+ */
+void media_devnode_unregister_prepare(struct media_devnode *devnode);
+
+void media_devnode_unregister(struct media_devnode *devnode);
 
 static inline struct media_devnode *media_devnode_data(struct file *filp)
 {
 	return filp->private_data;
 }
 
-static inline int media_devnode_is_registered(struct media_devnode *mdev)
+static inline int media_devnode_is_registered(struct media_devnode *devnode)
 {
-	return test_bit(MEDIA_FLAG_REGISTERED, &mdev->flags);
+	if (!devnode)
+		return false;
+
+	return test_bit(MEDIA_FLAG_REGISTERED, &devnode->flags);
 }
 
 #endif /* _MEDIA_DEVNODE_H */