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#define VIDEO_MAJOR     81
  20
  21#define VFL_TYPE_GRABBER        0
  22#define VFL_TYPE_VBI            1
  23#define VFL_TYPE_RADIO          2
  24#define VFL_TYPE_VTX            3
  25#define VFL_TYPE_MAX            4
  26
  27struct v4l2_ioctl_callbacks;
  28struct video_device;
  29struct v4l2_device;
  30
  31/* Flag to mark the video_device struct as unregistered.
  32   Drivers can set this flag if they want to block all future
  33   device access. It is set by video_unregister_device. */
  34#define V4L2_FL_UNREGISTERED    (0)
  35
  36struct v4l2_file_operations {
  37        struct module *owner;
  38        ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
  39        ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
  40        unsigned int (*poll) (struct file *, struct poll_table_struct *);
  41        long (*ioctl) (struct file *, unsigned int, unsigned long);
  42        long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
  43        unsigned long (*get_unmapped_area) (struct file *, unsigned long,
  44                                unsigned long, unsigned long, unsigned long);
  45        int (*mmap) (struct file *, struct vm_area_struct *);
  46        int (*open) (struct file *);
  47        int (*release) (struct file *);
  48};
  49
  50/*
  51 * Newer version of video_device, handled by videodev2.c
  52 *      This version moves redundant code from video device code to
  53 *      the common handler
  54 */
  55
  56struct video_device
  57{
  58        /* device ops */
  59        const struct v4l2_file_operations *fops;
  60
  61        /* sysfs */
  62        struct device dev;              /* v4l device */
  63        struct cdev *cdev;              /* character device */
  64
  65        /* Set either parent or v4l2_dev if your driver uses v4l2_device */
  66        struct device *parent;          /* device parent */
  67        struct v4l2_device *v4l2_dev;   /* v4l2_device parent */
  68
  69        /* device info */
  70        char name[32];
  71        int vfl_type;
  72        /* 'minor' is set to -1 if the registration failed */
  73        int minor;
  74        u16 num;
  75        /* use bitops to set/clear/test flags */
  76        unsigned long flags;
  77        /* attribute to differentiate multiple indices on one physical device */
  78        int index;
  79
  80        int debug;                      /* Activates debug level*/
  81
  82        /* Video standard vars */
  83        v4l2_std_id tvnorms;            /* Supported tv norms */
  84        v4l2_std_id current_norm;       /* Current tvnorm */
  85
  86        /* callbacks */
  87        void (*release)(struct video_device *vdev);
  88
  89        /* ioctl callbacks */
  90        const struct v4l2_ioctl_ops *ioctl_ops;
  91};
  92
  93/* dev to video-device */
  94#define to_video_device(cd) container_of(cd, struct video_device, dev)
  95
  96/* Register video devices. Note that if video_register_device fails,
  97   the release() callback of the video_device structure is *not* called, so
  98   the caller is responsible for freeing any data. Usually that means that
  99   you call video_device_release() on failure.
 100
 101   Also note that vdev->minor is set to -1 if the registration failed. */
 102int __must_check video_register_device(struct video_device *vdev, int type, int nr);
 103
 104/* Same as video_register_device, but no warning is issued if the desired
 105   device node number was already in use. */
 106int __must_check video_register_device_no_warn(struct video_device *vdev, int type, int nr);
 107
 108/* Unregister video devices. Will do nothing if vdev == NULL or
 109   vdev->minor < 0. */
 110void video_unregister_device(struct video_device *vdev);
 111
 112/* helper functions to alloc/release struct video_device, the
 113   latter can also be used for video_device->release(). */
 114struct video_device * __must_check video_device_alloc(void);
 115
 116/* this release function frees the vdev pointer */
 117void video_device_release(struct video_device *vdev);
 118
 119/* this release function does nothing, use when the video_device is a
 120   static global struct. Note that having a static video_device is
 121   a dubious construction at best. */
 122void video_device_release_empty(struct video_device *vdev);
 123
 124/* helper functions to access driver private data. */
 125static inline void *video_get_drvdata(struct video_device *vdev)
 126{
 127        return dev_get_drvdata(&vdev->dev);
 128}
 129
 130static inline void video_set_drvdata(struct video_device *vdev, void *data)
 131{
 132        dev_set_drvdata(&vdev->dev, data);
 133}
 134
 135struct video_device *video_devdata(struct file *file);
 136
 137/* Combine video_get_drvdata and video_devdata as this is
 138   used very often. */
 139static inline void *video_drvdata(struct file *file)
 140{
 141        return video_get_drvdata(video_devdata(file));
 142}
 143
 144static inline int video_is_unregistered(struct video_device *vdev)
 145{
 146        return test_bit(V4L2_FL_UNREGISTERED, &vdev->flags);
 147}
 148
 149#endif /* _V4L2_DEV_H */
 150