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Diffstat (limited to '')
| -rw-r--r-- | include/media/v4l2-dev.h | 543 |
1 files changed, 543 insertions, 0 deletions
diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h new file mode 100644 index 000000000..ad2d41952 --- /dev/null +++ b/include/media/v4l2-dev.h @@ -0,0 +1,543 @@ +/* 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 81 + +/** + * 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 { + VFL_TYPE_VIDEO, + VFL_TYPE_VBI, + VFL_TYPE_RADIO, + VFL_TYPE_SUBDEV, + VFL_TYPE_SDR, + VFL_TYPE_TOUCH, + VFL_TYPE_MAX /* Shall be the last one */ +}; + +/** + * enum vfl_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 { + VFL_DIR_RX, + VFL_DIR_TX, + VFL_DIR_M2M, +}; + +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 { + V4L2_FL_REGISTERED = 0, + V4L2_FL_USES_V4L2_FH = 1, + V4L2_FL_QUIRK_INVERTED_CROP = 2, + V4L2_FL_SUBDEV_RO_DEVNODE = 3, +}; + +/* 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 { + atomic_t prios[4]; +}; + +/** + * 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 { + struct module *owner; + ssize_t (*read) (struct file *, char __user *, size_t, loff_t *); + ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *); + __poll_t (*poll) (struct file *, struct poll_table_struct *); + long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long); +#ifdef CONFIG_COMPAT + long (*compat_ioctl32) (struct file *, unsigned int, unsigned long); +#endif + unsigned long (*get_unmapped_area) (struct file *, unsigned long, + unsigned long, unsigned long, unsigned long); + int (*mmap) (struct file *, struct vm_area_struct *); + int (*open) (struct file *); + int (*release) (struct file *); +}; + +/* + * 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 +{ +#if defined(CONFIG_MEDIA_CONTROLLER) + struct media_entity entity; + struct media_intf_devnode *intf_devnode; + struct media_pipeline pipe; +#endif + const struct v4l2_file_operations *fops; + + u32 device_caps; + + /* sysfs */ + struct device dev; + struct cdev *cdev; + + struct v4l2_device *v4l2_dev; + struct device *dev_parent; + + struct v4l2_ctrl_handler *ctrl_handler; + + struct vb2_queue *queue; + + struct v4l2_prio_state *prio; + + /* device info */ + char name[32]; + enum vfl_devnode_type vfl_type; + enum vfl_devnode_direction vfl_dir; + int minor; + u16 num; + unsigned long flags; + int index; + + /* V4L2 file handles */ + spinlock_t fh_lock; + struct list_head fh_list; + + int dev_debug; + + v4l2_std_id tvnorms; + + /* callbacks */ + void (*release)(struct video_device *vdev); + const struct v4l2_ioctl_ops *ioctl_ops; + DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE); + + struct mutex *lock; +}; + +/** + * 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) \ + container_of(__entity, struct 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) container_of(cd, struct video_device, dev) + +/** + * __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) +{ + return __video_register_device(vdev, type, nr, 1, vdev->fops->owner); +} + +/** + * 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) +{ + return __video_register_device(vdev, type, nr, 0, vdev->fops->owner); +} + +/** + * 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) +{ + if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE) + set_bit(_IOC_NR(cmd), vdev->valid_ioctls); +} + +/** + * 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) +{ + return dev_get_drvdata(&vdev->dev); +} + +/** + * 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) +{ + dev_set_drvdata(&vdev->dev, 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) +{ + return video_get_drvdata(video_devdata(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) +{ + return dev_name(&vdev->dev); +} + +/** + * 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) +{ + return test_bit(V4L2_FL_REGISTERED, &vdev->flags); +} + +#endif /* _V4L2_DEV_H */ |