diff options
Diffstat (limited to 'include/media/media-devnode.h')
-rw-r--r-- | include/media/media-devnode.h | 54 |
1 files changed, 53 insertions, 1 deletions
diff --git a/include/media/media-devnode.h b/include/media/media-devnode.h index 17ddae320..fe42f08e7 100644 --- a/include/media/media-devnode.h +++ b/include/media/media-devnode.h @@ -40,6 +40,20 @@ */ #define MEDIA_FLAG_REGISTERED 0 +/** + * struct media_file_operations - Media device file operations + * + * @owner: should be filled with %THIS_MODULE + * @read: pointer to the function that implements read() syscall + * @write: pointer to the function that implements write() syscall + * @poll: pointer to the function that implements poll() syscall + * @ioctl: pointer to the function that implements ioctl() syscall + * @compat_ioctl: pointer to the function that will handle 32 bits userspace + * calls to the the ioctl() syscall on a Kernel compiled with 64 bits. + * @open: pointer to the function that implements open() syscall + * @release: pointer to the function that will release the resources allocated + * by the @open function. + */ struct media_file_operations { struct module *owner; ssize_t (*read) (struct file *, char __user *, size_t, loff_t *); @@ -53,7 +67,7 @@ struct media_file_operations { /** * struct media_devnode - Media device node - * @fops: pointer to struct media_file_operations with media device ops + * @fops: pointer to struct &media_file_operations with media device ops * @dev: struct device pointer for the media controller device * @cdev: struct cdev pointer character device * @parent: parent device @@ -86,15 +100,53 @@ struct media_devnode { /* dev to media_devnode */ #define to_media_devnode(cd) container_of(cd, struct media_devnode, dev) +/** + * media_devnode_register - register a media device node + * + * @mdev: 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 + * with the kernel. An error is returned if no free minor number can be found, + * or if the registration of the device node fails. + * + * Zero is returned on success. + * + * Note that if the media_devnode_register call fails, the release() callback of + * 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, struct module *owner); + +/** + * media_devnode_unregister - unregister a media device node + * @mdev: 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. + */ void media_devnode_unregister(struct media_devnode *mdev); +/** + * media_devnode_data - returns a pointer to the &media_devnode + * + * @filp: pointer to struct &file + */ static inline struct media_devnode *media_devnode_data(struct file *filp) { return filp->private_data; } +/** + * media_devnode_is_registered - returns true if &media_devnode is registered; + * false otherwise. + * + * @mdev: pointer to struct &media_devnode. + */ static inline int media_devnode_is_registered(struct media_devnode *mdev) { return test_bit(MEDIA_FLAG_REGISTERED, &mdev->flags); |