/* 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_GRABBER: 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_GRABBER = 0,
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.
*/
enum v4l2_video_device_flags {
V4L2_FL_REGISTERED = 0,
V4L2_FL_USES_V4L2_FH = 1,
V4L2_FL_QUIRK_INVERTED_CROP = 2,
};
/* 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 */
