/* SPDX-License-Identifier: GPL-2.0 */ /* * * V 4 L 2 D R I V E R H E L P E R A P I * * Moved from videodev2.h * * Some commonly needed functions for drivers (v4l2-common.o module) */ #ifndef _V4L2_DEV_H #define _V4L2_DEV_H #include <linux/poll.h> #include <linux/fs.h> #include <linux/device.h> #include <linux/cdev.h> #include <linux/mutex.h> #include <linux/videodev2.h> #include <media/media-entity.h> #define VIDEO_MAJOR … /** * enum vfl_devnode_type - type of V4L2 device node * * @VFL_TYPE_VIDEO: for video input/output devices * @VFL_TYPE_VBI: for vertical blank data (i.e. closed captions, teletext) * @VFL_TYPE_RADIO: for radio tuners * @VFL_TYPE_SUBDEV: for V4L2 subdevices * @VFL_TYPE_SDR: for Software Defined Radio tuners * @VFL_TYPE_TOUCH: for touch sensors * @VFL_TYPE_MAX: number of VFL types, must always be last in the enum */ enum vfl_devnode_type { … }; /** * enum vfl_devnode_direction - Identifies if a &struct video_device * corresponds to a receiver, a transmitter or a mem-to-mem device. * * @VFL_DIR_RX: device is a receiver. * @VFL_DIR_TX: device is a transmitter. * @VFL_DIR_M2M: device is a memory to memory device. * * Note: Ignored if &enum vfl_devnode_type is %VFL_TYPE_SUBDEV. */ enum vfl_devnode_direction { … }; struct v4l2_ioctl_callbacks; struct video_device; struct v4l2_device; struct v4l2_ctrl_handler; /** * enum v4l2_video_device_flags - Flags used by &struct video_device * * @V4L2_FL_REGISTERED: * indicates that a &struct video_device is registered. * Drivers can clear this flag if they want to block all future * device access. It is cleared by video_unregister_device. * @V4L2_FL_USES_V4L2_FH: * indicates that file->private_data points to &struct v4l2_fh. * This flag is set by the core when v4l2_fh_init() is called. * All new drivers should use it. * @V4L2_FL_QUIRK_INVERTED_CROP: * some old M2M drivers use g/s_crop/cropcap incorrectly: crop and * compose are swapped. If this flag is set, then the selection * targets are swapped in the g/s_crop/cropcap functions in v4l2-ioctl.c. * This allows those drivers to correctly implement the selection API, * but the old crop API will still work as expected in order to preserve * backwards compatibility. * Never set this flag for new drivers. * @V4L2_FL_SUBDEV_RO_DEVNODE: * indicates that the video device node is registered in read-only mode. * The flag only applies to device nodes registered for sub-devices, it is * set by the core when the sub-devices device nodes are registered with * v4l2_device_register_ro_subdev_nodes() and used by the sub-device ioctl * handler to restrict access to some ioctl calls. */ enum v4l2_video_device_flags { … }; /* Priority helper functions */ /** * struct v4l2_prio_state - stores the priority states * * @prios: array with elements to store the array priorities * * * .. note:: * The size of @prios array matches the number of priority types defined * by enum &v4l2_priority. */ struct v4l2_prio_state { … }; /** * v4l2_prio_init - initializes a struct v4l2_prio_state * * @global: pointer to &struct v4l2_prio_state */ void v4l2_prio_init(struct v4l2_prio_state *global); /** * v4l2_prio_change - changes the v4l2 file handler priority * * @global: pointer to the &struct v4l2_prio_state of the device node. * @local: pointer to the desired priority, as defined by enum &v4l2_priority * @new: Priority type requested, as defined by enum &v4l2_priority. * * .. note:: * This function should be used only by the V4L2 core. */ int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local, enum v4l2_priority new); /** * v4l2_prio_open - Implements the priority logic for a file handler open * * @global: pointer to the &struct v4l2_prio_state of the device node. * @local: pointer to the desired priority, as defined by enum &v4l2_priority * * .. note:: * This function should be used only by the V4L2 core. */ void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local); /** * v4l2_prio_close - Implements the priority logic for a file handler close * * @global: pointer to the &struct v4l2_prio_state of the device node. * @local: priority to be released, as defined by enum &v4l2_priority * * .. note:: * This function should be used only by the V4L2 core. */ void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local); /** * v4l2_prio_max - Return the maximum priority, as stored at the @global array. * * @global: pointer to the &struct v4l2_prio_state of the device node. * * .. note:: * This function should be used only by the V4L2 core. */ enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global); /** * v4l2_prio_check - Implements the priority logic for a file handler close * * @global: pointer to the &struct v4l2_prio_state of the device node. * @local: desired priority, as defined by enum &v4l2_priority local * * .. note:: * This function should be used only by the V4L2 core. */ int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local); /** * struct v4l2_file_operations - fs operations used by a V4L2 device * * @owner: pointer to struct module * @read: operations needed to implement the read() syscall * @write: operations needed to implement the write() syscall * @poll: operations needed to implement the poll() syscall * @unlocked_ioctl: operations needed to implement the ioctl() syscall * @compat_ioctl32: operations needed to implement the ioctl() syscall for * the special case where the Kernel uses 64 bits instructions, but * the userspace uses 32 bits. * @get_unmapped_area: called by the mmap() syscall, used when %!CONFIG_MMU * @mmap: operations needed to implement the mmap() syscall * @open: operations needed to implement the open() syscall * @release: operations needed to implement the release() syscall * * .. note:: * * Those operations are used to implemente the fs struct file_operations * at the V4L2 drivers. The V4L2 core overrides the fs ops with some * extra logic needed by the subsystem. */ struct v4l2_file_operations { … }; /* * Newer version of video_device, handled by videodev2.c * This version moves redundant code from video device code to * the common handler */ /** * struct video_device - Structure used to create and manage the V4L2 device * nodes. * * @entity: &struct media_entity * @intf_devnode: pointer to &struct media_intf_devnode * @pipe: &struct media_pipeline * @fops: pointer to &struct v4l2_file_operations for the video device * @device_caps: device capabilities as used in v4l2_capabilities * @dev: &struct device for the video device * @cdev: character device * @v4l2_dev: pointer to &struct v4l2_device parent * @dev_parent: pointer to &struct device parent * @ctrl_handler: Control handler associated with this device node. * May be NULL. * @queue: &struct vb2_queue associated with this device node. May be NULL. * @prio: pointer to &struct v4l2_prio_state with device's Priority state. * If NULL, then v4l2_dev->prio will be used. * @name: video device name * @vfl_type: V4L device type, as defined by &enum vfl_devnode_type * @vfl_dir: V4L receiver, transmitter or m2m * @minor: device node 'minor'. It is set to -1 if the registration failed * @num: number of the video device node * @flags: video device flags. Use bitops to set/clear/test flags. * Contains a set of &enum v4l2_video_device_flags. * @index: attribute to differentiate multiple indices on one physical device * @fh_lock: Lock for all v4l2_fhs * @fh_list: List of &struct v4l2_fh * @dev_debug: Internal device debug flags, not for use by drivers * @tvnorms: Supported tv norms * * @release: video device release() callback * @ioctl_ops: pointer to &struct v4l2_ioctl_ops with ioctl callbacks * * @valid_ioctls: bitmap with the valid ioctls for this device * @lock: pointer to &struct mutex serialization lock * * .. note:: * Only set @dev_parent if that can't be deduced from @v4l2_dev. */ struct video_device { … }; /** * media_entity_to_video_device - Returns a &struct video_device from * the &struct media_entity embedded on it. * * @__entity: pointer to &struct media_entity */ #define media_entity_to_video_device(__entity) … /** * to_video_device - Returns a &struct video_device from the * &struct device embedded on it. * * @cd: pointer to &struct device */ #define to_video_device(cd) … /** * __video_register_device - register video4linux devices * * @vdev: struct video_device to register * @type: type of device to register, as defined by &enum vfl_devnode_type * @nr: which device node number is desired: * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free) * @warn_if_nr_in_use: warn if the desired device node number * was already in use and another number was chosen instead. * @owner: module that owns the video device node * * The registration code assigns minor numbers and device node numbers * based on the requested type and registers the new device node with * the kernel. * * This function assumes that struct video_device was zeroed when it * was allocated and does not contain any stale date. * * An error is returned if no free minor or device node number could be * found, or if the registration of the device node failed. * * Returns 0 on success. * * .. note:: * * This function is meant to be used only inside the V4L2 core. * Drivers should use video_register_device() or * video_register_device_no_warn(). */ int __must_check __video_register_device(struct video_device *vdev, enum vfl_devnode_type type, int nr, int warn_if_nr_in_use, struct module *owner); /** * video_register_device - register video4linux devices * * @vdev: struct video_device to register * @type: type of device to register, as defined by &enum vfl_devnode_type * @nr: which device node number is desired: * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free) * * Internally, it calls __video_register_device(). Please see its * documentation for more details. * * .. note:: * if video_register_device fails, the release() callback of * &struct video_device structure is *not* called, so the caller * is responsible for freeing any data. Usually that means that * you video_device_release() should be called on failure. */ static inline int __must_check video_register_device(struct video_device *vdev, enum vfl_devnode_type type, int nr) { … } /** * video_register_device_no_warn - register video4linux devices * * @vdev: struct video_device to register * @type: type of device to register, as defined by &enum vfl_devnode_type * @nr: which device node number is desired: * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free) * * This function is identical to video_register_device() except that no * warning is issued if the desired device node number was already in use. * * Internally, it calls __video_register_device(). Please see its * documentation for more details. * * .. note:: * if video_register_device fails, the release() callback of * &struct video_device structure is *not* called, so the caller * is responsible for freeing any data. Usually that means that * you video_device_release() should be called on failure. */ static inline int __must_check video_register_device_no_warn(struct video_device *vdev, enum vfl_devnode_type type, int nr) { … } /** * video_unregister_device - Unregister video devices. * * @vdev: &struct video_device to register * * Does nothing if vdev == NULL or if video_is_registered() returns false. */ void video_unregister_device(struct video_device *vdev); /** * video_device_alloc - helper function to alloc &struct video_device * * Returns NULL if %-ENOMEM or a &struct video_device on success. */ struct video_device * __must_check video_device_alloc(void); /** * video_device_release - helper function to release &struct video_device * * @vdev: pointer to &struct video_device * * Can also be used for video_device->release\(\). */ void video_device_release(struct video_device *vdev); /** * video_device_release_empty - helper function to implement the * video_device->release\(\) callback. * * @vdev: pointer to &struct video_device * * This release function does nothing. * * It should be used when the video_device is a static global struct. * * .. note:: * Having a static video_device is a dubious construction at best. */ void video_device_release_empty(struct video_device *vdev); /** * v4l2_disable_ioctl- mark that a given command isn't implemented. * shouldn't use core locking * * @vdev: pointer to &struct video_device * @cmd: ioctl command * * This function allows drivers to provide just one v4l2_ioctl_ops struct, but * disable ioctls based on the specific card that is actually found. * * .. note:: * * This must be called before video_register_device. * See also the comments for determine_valid_ioctls(). */ static inline void v4l2_disable_ioctl(struct video_device *vdev, unsigned int cmd) { … } /** * video_get_drvdata - gets private data from &struct video_device. * * @vdev: pointer to &struct video_device * * returns a pointer to the private data */ static inline void *video_get_drvdata(struct video_device *vdev) { … } /** * video_set_drvdata - sets private data from &struct video_device. * * @vdev: pointer to &struct video_device * @data: private data pointer */ static inline void video_set_drvdata(struct video_device *vdev, void *data) { … } /** * video_devdata - gets &struct video_device from struct file. * * @file: pointer to struct file */ struct video_device *video_devdata(struct file *file); /** * video_drvdata - gets private data from &struct video_device using the * struct file. * * @file: pointer to struct file * * This is function combines both video_get_drvdata() and video_devdata() * as this is used very often. */ static inline void *video_drvdata(struct file *file) { … } /** * video_device_node_name - returns the video device name * * @vdev: pointer to &struct video_device * * Returns the device name string */ static inline const char *video_device_node_name(struct video_device *vdev) { … } /** * video_is_registered - returns true if the &struct video_device is registered. * * * @vdev: pointer to &struct video_device */ static inline int video_is_registered(struct video_device *vdev) { … } #if defined(CONFIG_MEDIA_CONTROLLER) /** * video_device_pipeline_start - Mark a pipeline as streaming * @vdev: Starting video device * @pipe: Media pipeline to be assigned to all entities in the pipeline. * * Mark all entities connected to a given video device through enabled links, * either directly or indirectly, as streaming. The given pipeline object is * assigned to every pad in the pipeline and stored in the media_pad pipe * field. * * Calls to this function can be nested, in which case the same number of * video_device_pipeline_stop() calls will be required to stop streaming. The * pipeline pointer must be identical for all nested calls to * video_device_pipeline_start(). * * The video device must contain a single pad. * * This is a convenience wrapper around media_pipeline_start(). */ __must_check int video_device_pipeline_start(struct video_device *vdev, struct media_pipeline *pipe); /** * __video_device_pipeline_start - Mark a pipeline as streaming * @vdev: Starting video device * @pipe: Media pipeline to be assigned to all entities in the pipeline. * * ..note:: This is the non-locking version of video_device_pipeline_start() * * The video device must contain a single pad. * * This is a convenience wrapper around __media_pipeline_start(). */ __must_check int __video_device_pipeline_start(struct video_device *vdev, struct media_pipeline *pipe); /** * video_device_pipeline_stop - Mark a pipeline as not streaming * @vdev: Starting video device * * Mark all entities connected to a given video device through enabled links, * either directly or indirectly, as not streaming. The media_pad pipe field * is reset to %NULL. * * If multiple calls to media_pipeline_start() have been made, the same * number of calls to this function are required to mark the pipeline as not * streaming. * * The video device must contain a single pad. * * This is a convenience wrapper around media_pipeline_stop(). */ void video_device_pipeline_stop(struct video_device *vdev); /** * __video_device_pipeline_stop - Mark a pipeline as not streaming * @vdev: Starting video device * * .. note:: This is the non-locking version of media_pipeline_stop() * * The video device must contain a single pad. * * This is a convenience wrapper around __media_pipeline_stop(). */ void __video_device_pipeline_stop(struct video_device *vdev); /** * video_device_pipeline_alloc_start - Mark a pipeline as streaming * @vdev: Starting video device * * video_device_pipeline_alloc_start() is similar to video_device_pipeline_start() * but instead of working on a given pipeline the function will use an * existing pipeline if the video device is already part of a pipeline, or * allocate a new pipeline. * * Calls to video_device_pipeline_alloc_start() must be matched with * video_device_pipeline_stop(). */ __must_check int video_device_pipeline_alloc_start(struct video_device *vdev); /** * video_device_pipeline - Get the media pipeline a video device is part of * @vdev: The video device * * This function returns the media pipeline that a video device has been * associated with when constructing the pipeline with * video_device_pipeline_start(). The pointer remains valid until * video_device_pipeline_stop() is called. * * Return: The media_pipeline the video device is part of, or NULL if the video * device is not part of any pipeline. * * The video device must contain a single pad. * * This is a convenience wrapper around media_entity_pipeline(). */ struct media_pipeline *video_device_pipeline(struct video_device *vdev); #endif /* CONFIG_MEDIA_CONTROLLER */ #endif /* _V4L2_DEV_H */
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