LXR linux/include/media/v4l2-dev.h

   1/*
   2 *
   3 *      V 4 L 2   D R I V E R   H E L P E R   A P I
   4 *
   5 * Moved from videodev2.h
   6 *
   7 *      Some commonly needed functions for drivers (v4l2-common.o module)
   8 */
   9#ifndef _V4L2_DEV_H
  10#define _V4L2_DEV_H
  11
  12#include <linux/poll.h>
  13#include <linux/fs.h>
  14#include <linux/device.h>
  15#include <linux/cdev.h>
  16#include <linux/mutex.h>
  17#include <linux/videodev2.h>
  18
  19#include <media/media-entity.h>
  20
  21#define VIDEO_MAJOR     81
  22
  23#define VFL_TYPE_GRABBER        0
  24#define VFL_TYPE_VBI            1
  25#define VFL_TYPE_RADIO          2
  26#define VFL_TYPE_SUBDEV         3
  27#define VFL_TYPE_MAX            4
  28
  29struct v4l2_ioctl_callbacks;
  30struct video_device;
  31struct v4l2_device;
  32struct v4l2_ctrl_handler;
  33
  34/* Flag to mark the video_device struct as registered.
  35   Drivers can clear this flag if they want to block all future
  36   device access. It is cleared by video_unregister_device. */
  37#define V4L2_FL_REGISTERED      (0)
  38/* file->private_data points to struct v4l2_fh */
  39#define V4L2_FL_USES_V4L2_FH    (1)
  40/* Use the prio field of v4l2_fh for core priority checking */
  41#define V4L2_FL_USE_FH_PRIO     (2)
  42
  43/* Priority helper functions */
  44
  45struct v4l2_prio_state {
  46        atomic_t prios[4];
  47};
  48
  49void v4l2_prio_init(struct v4l2_prio_state *global);
  50int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
  51                     enum v4l2_priority new);
  52void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local);
  53void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local);
  54enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global);
  55int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local);
  56
  57
  58struct v4l2_file_operations {
  59        struct module *owner;
  60        ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
  61        ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
  62        unsigned int (*poll) (struct file *, struct poll_table_struct *);
  63        long (*ioctl) (struct file *, unsigned int, unsigned long);
  64        long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
  65#ifdef CONFIG_COMPAT
  66        long (*compat_ioctl32) (struct file *, unsigned int, unsigned long);
  67#endif
  68        unsigned long (*get_unmapped_area) (struct file *, unsigned long,
  69                                unsigned long, unsigned long, unsigned long);
  70        int (*mmap) (struct file *, struct vm_area_struct *);
  71        int (*open) (struct file *);
  72        int (*release) (struct file *);
  73};
  74
  75/*
  76 * Newer version of video_device, handled by videodev2.c
  77 *      This version moves redundant code from video device code to
  78 *      the common handler
  79 */
  80
  81struct video_device
  82{
  83#if defined(CONFIG_MEDIA_CONTROLLER)
  84        struct media_entity entity;
  85#endif
  86        /* device ops */
  87        const struct v4l2_file_operations *fops;
  88
  89        /* sysfs */
  90        struct device dev;              /* v4l device */
  91        struct cdev *cdev;              /* character device */
  92
  93        /* Set either parent or v4l2_dev if your driver uses v4l2_device */
  94        struct device *parent;          /* device parent */
  95        struct v4l2_device *v4l2_dev;   /* v4l2_device parent */
  96
  97        /* Control handler associated with this device node. May be NULL. */
  98        struct v4l2_ctrl_handler *ctrl_handler;
  99
 100        /* Priority state. If NULL, then v4l2_dev->prio will be used. */
 101        struct v4l2_prio_state *prio;
 102
 103        /* device info */
 104        char name[32];
 105        int vfl_type;
 106        /* 'minor' is set to -1 if the registration failed */
 107        int minor;
 108        u16 num;
 109        /* use bitops to set/clear/test flags */
 110        unsigned long flags;
 111        /* attribute to differentiate multiple indices on one physical device */
 112        int index;
 113
 114        /* V4L2 file handles */
 115        spinlock_t              fh_lock; /* Lock for all v4l2_fhs */
 116        struct list_head        fh_list; /* List of struct v4l2_fh */
 117
 118        int debug;                      /* Activates debug level*/
 119
 120        /* Video standard vars */
 121        v4l2_std_id tvnorms;            /* Supported tv norms */
 122        v4l2_std_id current_norm;       /* Current tvnorm */
 123
 124        /* callbacks */
 125        void (*release)(struct video_device *vdev);
 126
 127        /* ioctl callbacks */
 128        const struct v4l2_ioctl_ops *ioctl_ops;
 129
 130        /* serialization lock */
 131        struct mutex *lock;
 132};
 133
 134#define media_entity_to_video_device(__e) \
 135        container_of(__e, struct video_device, entity)
 136/* dev to video-device */
 137#define to_video_device(cd) container_of(cd, struct video_device, dev)
 138
 139int __must_check __video_register_device(struct video_device *vdev, int type,
 140                int nr, int warn_if_nr_in_use, struct module *owner);
 141
 142/* Register video devices. Note that if video_register_device fails,
 143   the release() callback of the video_device structure is *not* called, so
 144   the caller is responsible for freeing any data. Usually that means that
 145   you call video_device_release() on failure. */
 146static inline int __must_check video_register_device(struct video_device *vdev,
 147                int type, int nr)
 148{
 149        return __video_register_device(vdev, type, nr, 1, vdev->fops->owner);
 150}
 151
 152/* Same as video_register_device, but no warning is issued if the desired
 153   device node number was already in use. */
 154static inline int __must_check video_register_device_no_warn(
 155                struct video_device *vdev, int type, int nr)
 156{
 157        return __video_register_device(vdev, type, nr, 0, vdev->fops->owner);
 158}
 159
 160/* Unregister video devices. Will do nothing if vdev == NULL or
 161   video_is_registered() returns false. */
 162void video_unregister_device(struct video_device *vdev);
 163
 164/* helper functions to alloc/release struct video_device, the
 165   latter can also be used for video_device->release(). */
 166struct video_device * __must_check video_device_alloc(void);
 167
 168/* this release function frees the vdev pointer */
 169void video_device_release(struct video_device *vdev);
 170
 171/* this release function does nothing, use when the video_device is a
 172   static global struct. Note that having a static video_device is
 173   a dubious construction at best. */
 174void video_device_release_empty(struct video_device *vdev);
 175
 176/* helper functions to access driver private data. */
 177static inline void *video_get_drvdata(struct video_device *vdev)
 178{
 179        return dev_get_drvdata(&vdev->dev);
 180}
 181
 182static inline void video_set_drvdata(struct video_device *vdev, void *data)
 183{
 184        dev_set_drvdata(&vdev->dev, data);
 185}
 186
 187struct video_device *video_devdata(struct file *file);
 188
 189/* Combine video_get_drvdata and video_devdata as this is
 190   used very often. */
 191static inline void *video_drvdata(struct file *file)
 192{
 193        return video_get_drvdata(video_devdata(file));
 194}
 195
 196static inline const char *video_device_node_name(struct video_device *vdev)
 197{
 198        return dev_name(&vdev->dev);
 199}
 200
 201static inline int video_is_registered(struct video_device *vdev)
 202{
 203        return test_bit(V4L2_FL_REGISTERED, &vdev->flags);
 204}
 205
 206#endif /* _V4L2_DEV_H */
 207