blob: 96d22215cc881a1d8a836c8312e86378efb7a51d [file] [log] [blame]
* 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
#define VFL_TYPE_VBI 1
#define VFL_TYPE_RADIO 2
#define VFL_TYPE_MAX 4
struct v4l2_ioctl_callbacks;
struct video_device;
struct v4l2_device;
struct v4l2_ctrl_handler;
/* Flag to mark the video_device struct as registered.
Drivers can clear this flag if they want to block all future
device access. It is cleared by video_unregister_device. */
#define V4L2_FL_REGISTERED (0)
/* file->private_data points to struct v4l2_fh */
#define V4L2_FL_USES_V4L2_FH (1)
/* Use the prio field of v4l2_fh for core priority checking */
#define V4L2_FL_USE_FH_PRIO (2)
/* Priority helper functions */
struct v4l2_prio_state {
atomic_t prios[4];
void v4l2_prio_init(struct v4l2_prio_state *global);
int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
enum v4l2_priority new);
void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local);
void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local);
enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global);
int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local);
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 *);
unsigned int (*poll) (struct file *, struct poll_table_struct *);
long (*ioctl) (struct file *, unsigned int, unsigned long);
long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
long (*compat_ioctl32) (struct file *, unsigned int, unsigned long);
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
struct media_entity entity;
/* device ops */
const struct v4l2_file_operations *fops;
/* sysfs */
struct device dev; /* v4l device */
struct cdev *cdev; /* character device */
/* Set either parent or v4l2_dev if your driver uses v4l2_device */
struct device *parent; /* device parent */
struct v4l2_device *v4l2_dev; /* v4l2_device parent */
/* Control handler associated with this device node. May be NULL. */
struct v4l2_ctrl_handler *ctrl_handler;
/* Priority state. If NULL, then v4l2_dev->prio will be used. */
struct v4l2_prio_state *prio;
/* device info */
char name[32];
int vfl_type;
/* 'minor' is set to -1 if the registration failed */
int minor;
u16 num;
/* use bitops to set/clear/test flags */
unsigned long flags;
/* attribute to differentiate multiple indices on one physical device */
int index;
/* V4L2 file handles */
spinlock_t fh_lock; /* Lock for all v4l2_fhs */
struct list_head fh_list; /* List of struct v4l2_fh */
int debug; /* Activates debug level*/
/* Video standard vars */
v4l2_std_id tvnorms; /* Supported tv norms */
v4l2_std_id current_norm; /* Current tvnorm */
/* callbacks */
void (*release)(struct video_device *vdev);
/* ioctl callbacks */
const struct v4l2_ioctl_ops *ioctl_ops;
/* serialization lock */
struct mutex *lock;
#define media_entity_to_video_device(__e) \
container_of(__e, struct video_device, entity)
/* dev to video-device */
#define to_video_device(cd) container_of(cd, struct video_device, dev)
int __must_check __video_register_device(struct video_device *vdev, int type,
int nr, int warn_if_nr_in_use, struct module *owner);
/* Register video devices. Note that if video_register_device fails,
the release() callback of the video_device structure is *not* called, so
the caller is responsible for freeing any data. Usually that means that
you call video_device_release() on failure. */
static inline int __must_check video_register_device(struct video_device *vdev,
int type, int nr)
return __video_register_device(vdev, type, nr, 1, vdev->fops->owner);
/* Same as video_register_device, but no warning is issued if the desired
device node number was already in use. */
static inline int __must_check video_register_device_no_warn(
struct video_device *vdev, int type, int nr)
return __video_register_device(vdev, type, nr, 0, vdev->fops->owner);
/* Unregister video devices. Will do nothing if vdev == NULL or
video_is_registered() returns false. */
void video_unregister_device(struct video_device *vdev);
/* helper functions to alloc/release struct video_device, the
latter can also be used for video_device->release(). */
struct video_device * __must_check video_device_alloc(void);
/* this release function frees the vdev pointer */
void video_device_release(struct video_device *vdev);
/* this release function does nothing, use when the video_device is a
static global struct. Note that having a static video_device is
a dubious construction at best. */
void video_device_release_empty(struct video_device *vdev);
/* helper functions to access driver private data. */
static inline void *video_get_drvdata(struct video_device *vdev)
return dev_get_drvdata(&vdev->dev);
static inline void video_set_drvdata(struct video_device *vdev, void *data)
dev_set_drvdata(&vdev->dev, data);
struct video_device *video_devdata(struct file *file);
/* Combine 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));
static inline const char *video_device_node_name(struct video_device *vdev)
return dev_name(&vdev->dev);
static inline int video_is_registered(struct video_device *vdev)
return test_bit(V4L2_FL_REGISTERED, &vdev->flags);
#endif /* _V4L2_DEV_H */