diff options
Diffstat (limited to 'include/media/media-devnode.h')
| -rw-r--r-- | include/media/media-devnode.h | 51 |
1 files changed, 38 insertions, 13 deletions
diff --git a/include/media/media-devnode.h b/include/media/media-devnode.h index fe42f08e72bd..cd23e915764c 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 @@ -67,13 +69,15 @@ struct media_file_operations { /** * struct media_devnode - Media device node + * @media_dev: pointer to struct &media_device * @fops: pointer to struct &media_file_operations with media device ops - * @dev: struct device pointer for the media controller device + * @dev: pointer to struct &device containing the media controller device * @cdev: struct cdev pointer character device * @parent: parent device * @minor: device node minor number - * @flags: flags, combination of the MEDIA_FLAG_* constants - * @release: release callback called at the end of media_devnode_release() + * @flags: flags, combination of the ``MEDIA_FLAG_*`` constants + * @release: release callback called at the end of ``media_devnode_release()`` + * routine at media-device.c. * * This structure represents a media-related device node. * @@ -81,6 +85,8 @@ struct media_file_operations { * before registering the node. */ struct media_devnode { + struct media_device *media_dev; + /* device ops */ const struct media_file_operations *fops; @@ -94,7 +100,7 @@ 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 */ @@ -103,7 +109,8 @@ struct media_devnode { /** * media_devnode_register - register a media device node * - * @mdev: media device node structure we want to register + * @mdev: struct media_device we want to register a device node + * @devnode: media device node structure we want to register * @owner: should be filled with %THIS_MODULE * * The registration code assigns minor numbers and registers the new device node @@ -116,20 +123,33 @@ struct media_devnode { * the media_devnode structure is *not* called, so the caller is responsible for * freeing any data. */ -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); /** + * 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); + +/** * media_devnode_unregister - unregister a media device node - * @mdev: the device node to unregister + * @devnode: the device node to unregister * * This unregisters the passed device. Future open calls will be met with * errors. * - * This function can safely be called if the device node has never been - * registered or has already been unregistered. + * Should be called after media_devnode_unregister_prepare() */ -void media_devnode_unregister(struct media_devnode *mdev); +void media_devnode_unregister(struct media_devnode *devnode); /** * media_devnode_data - returns a pointer to the &media_devnode @@ -145,11 +165,16 @@ static inline struct media_devnode *media_devnode_data(struct file *filp) * media_devnode_is_registered - returns true if &media_devnode is registered; * false otherwise. * - * @mdev: pointer to struct &media_devnode. + * @devnode: pointer to struct &media_devnode. + * + * Note: If mdev is NULL, it also returns false. */ -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 */ |