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 struct video_device;
  29 struct 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
  36 struct 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         int (*mmap) (struct file *, struct vm_area_struct *);
  44         int (*open) (struct file *);
  45         int (*release) (struct file *);
  46 };
  47
  48 /*
  49  * Newer version of video_device, handled by videodev2.c
  50  *      This version moves redundant code from video device code to
  51  *      the common handler
  52  */
  53
  54 struct video_device
  55 {
  56         /* device ops */
  57         const struct v4l2_file_operations *fops;
  58
  59         /* sysfs */
  60         struct device dev;              /* v4l device */
  61         struct cdev *cdev;              /* character device */
  62
  63         /* Set either parent or v4l2_dev if your driver uses v4l2_device */
  64         struct device *parent;          /* device parent */
  65         struct v4l2_device *v4l2_dev;   /* v4l2_device parent */
  66
  67         /* device info */
  68         char name[32];
  69         int vfl_type;
  70         /* 'minor' is set to -1 if the registration failed */
  71         int minor;
  72         u16 num;
  73         /* use bitops to set/clear/test flags */
  74         unsigned long flags;
  75         /* attribute to differentiate multiple indices on one physical device */
  76         int index;
  77
  78         int debug;                      /* Activates debug level*/
  79
  80         /* Video standard vars */
  81         v4l2_std_id tvnorms;            /* Supported tv norms */
  82         v4l2_std_id current_norm;       /* Current tvnorm */
  83
  84         /* callbacks */
  85         void (*release)(struct video_device *vdev);
  86
  87         /* ioctl callbacks */
  88         const struct v4l2_ioctl_ops *ioctl_ops;
  89 };
  90
  91 /* dev to video-device */
  92 #define to_video_device(cd) container_of(cd, struct video_device, dev)
  93
  94 /* Register video devices. Note that if video_register_device fails,
  95    the release() callback of the video_device structure is *not* called, so
  96    the caller is responsible for freeing any data. Usually that means that
  97    you call video_device_release() on failure.
  98
  99    Also note that vdev->minor is set to -1 if the registration failed. */
 100 int __must_check video_register_device(struct video_device *vdev, int type, int nr);
 101 int __must_check video_register_device_index(struct video_device *vdev,
 102                                                 int type, int nr, int index);
 103
 104 /* Unregister video devices. Will do nothing if vdev == NULL or
 105    vdev->minor < 0. */
 106 void video_unregister_device(struct video_device *vdev);
 107
 108 /* helper functions to alloc/release struct video_device, the
 109    latter can also be used for video_device->release(). */
 110 struct video_device * __must_check video_device_alloc(void);
 111
 112 /* this release function frees the vdev pointer */
 113 void video_device_release(struct video_device *vdev);
 114
 115 /* this release function does nothing, use when the video_device is a
 116    static global struct. Note that having a static video_device is
 117    a dubious construction at best. */
 118 void video_device_release_empty(struct video_device *vdev);
 119
 120 /* helper functions to access driver private data. */
 121 static inline void *video_get_drvdata(struct video_device *vdev)
 122 {
 123         return dev_get_drvdata(&vdev->dev);
 124 }
 125
 126 static inline void video_set_drvdata(struct video_device *vdev, void *data)
 127 {
 128         dev_set_drvdata(&vdev->dev, data);
 129 }
 130
 131 struct video_device *video_devdata(struct file *file);
 132
 133 /* Combine video_get_drvdata and video_devdata as this is
 134    used very often. */
 135 static inline void *video_drvdata(struct file *file)
 136 {
 137         return video_get_drvdata(video_devdata(file));
 138 }
 139
 140 static inline int video_is_unregistered(struct video_device *vdev)
 141 {
 142         return test_bit(V4L2_FL_UNREGISTERED, &vdev->flags);
 143 }
 144
 145 #endif /* _V4L2_DEV_H */