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
  27 struct v4l2_ioctl_callbacks;
  28
  29 /*
  30  * Newer version of video_device, handled by videodev2.c
  31  *      This version moves redundant code from video device code to
  32  *      the common handler
  33  */
  34
  35 struct video_device
  36 {
  37         /* device ops */
  38         const struct file_operations *fops;
  39
  40         /* sysfs */
  41         struct device dev;              /* v4l device */
  42         struct cdev cdev;               /* character device */
  43         void (*cdev_release)(struct kobject *kobj);
  44         struct device *parent;          /* device parent */
  45
  46         /* device info */
  47         char name[32];
  48         int vfl_type;
  49         int minor;
  50         u16 num;
  51         /* attribute to differentiate multiple indices on one physical device */
  52         int index;
  53
  54         int debug;                      /* Activates debug level*/
  55
  56         /* Video standard vars */
  57         v4l2_std_id tvnorms;            /* Supported tv norms */
  58         v4l2_std_id current_norm;       /* Current tvnorm */
  59
  60         /* callbacks */
  61         void (*release)(struct video_device *vfd);
  62
  63         /* ioctl callbacks */
  64         const struct v4l2_ioctl_ops *ioctl_ops;
  65 };
  66
  67 /* dev to video-device */
  68 #define to_video_device(cd) container_of(cd, struct video_device, dev)
  69
  70 /* Register and unregister devices. Note that if video_register_device fails,
  71    the release() callback of the video_device structure is *not* called, so
  72    the caller is responsible for freeing any data. Usually that means that
  73    you call video_device_release() on failure. */
  74 int __must_check video_register_device(struct video_device *vfd, int type, int nr);
  75 int __must_check video_register_device_index(struct video_device *vfd,
  76                                                 int type, int nr, int index);
  77 void video_unregister_device(struct video_device *vfd);
  78
  79 /* helper functions to alloc/release struct video_device, the
  80    latter can also be used for video_device->release(). */
  81 struct video_device * __must_check video_device_alloc(void);
  82
  83 /* this release function frees the vfd pointer */
  84 void video_device_release(struct video_device *vfd);
  85
  86 /* this release function does nothing, use when the video_device is a
  87    static global struct. Note that having a static video_device is
  88    a dubious construction at best. */
  89 void video_device_release_empty(struct video_device *vfd);
  90
  91 /* helper functions to access driver private data. */
  92 static inline void *video_get_drvdata(struct video_device *dev)
  93 {
  94         return dev_get_drvdata(&dev->dev);
  95 }
  96
  97 static inline void video_set_drvdata(struct video_device *dev, void *data)
  98 {
  99         dev_set_drvdata(&dev->dev, data);
 100 }
 101
 102 struct video_device *video_devdata(struct file *file);
 103
 104 /* Combine video_get_drvdata and video_devdata as this is
 105    used very often. */
 106 static inline void *video_drvdata(struct file *file)
 107 {
 108         return video_get_drvdata(video_devdata(file));
 109 }
 110
 111 #endif /* _V4L2_DEV_H */