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_MAX            3
  25
  26 struct v4l2_ioctl_callbacks;
  27 struct video_device;
  28 struct v4l2_device;
  29 struct v4l2_ctrl_handler;
  30
  31 /* Flag to mark the video_device struct as registered.
  32    Drivers can clear this flag if they want to block all future
  33    device access. It is cleared by video_unregister_device. */
  34 #define V4L2_FL_REGISTERED      (0)
  35 #define V4L2_FL_USES_V4L2_FH    (1)
  36
  37 struct v4l2_file_operations {
  38         struct module *owner;
  39         ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
  40         ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
  41         unsigned int (*poll) (struct file *, struct poll_table_struct *);
  42         long (*ioctl) (struct file *, unsigned int, unsigned long);
  43         long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
  44         int (*mmap) (struct file *, struct vm_area_struct *);
  45         int (*open) (struct file *);
  46         int (*release) (struct file *);
  47 };
  48
  49 /*
  50  * Newer version of video_device, handled by videodev2.c
  51  *      This version moves redundant code from video device code to
  52  *      the common handler
  53  */
  54
  55 struct video_device
  56 {
  57         /* device ops */
  58         const struct v4l2_file_operations *fops;
  59
  60         /* sysfs */
  61         struct device dev;              /* v4l device */
  62         struct cdev *cdev;              /* character device */
  63
  64         /* Set either parent or v4l2_dev if your driver uses v4l2_device */
  65         struct device *parent;          /* device parent */
  66         struct v4l2_device *v4l2_dev;   /* v4l2_device parent */
  67
  68         /* Control handler associated with this device node. May be NULL. */
  69         struct v4l2_ctrl_handler *ctrl_handler;
  70
  71         /* device info */
  72         char name[32];
  73         int vfl_type;
  74         /* 'minor' is set to -1 if the registration failed */
  75         int minor;
  76         u16 num;
  77         /* use bitops to set/clear/test flags */
  78         unsigned long flags;
  79         /* attribute to differentiate multiple indices on one physical device */
  80         int index;
  81
  82         /* V4L2 file handles */
  83         spinlock_t              fh_lock; /* Lock for all v4l2_fhs */
  84         struct list_head        fh_list; /* List of struct v4l2_fh */
  85
  86         int debug;                      /* Activates debug level*/
  87
  88         /* Video standard vars */
  89         v4l2_std_id tvnorms;            /* Supported tv norms */
  90         v4l2_std_id current_norm;       /* Current tvnorm */
  91
  92         /* callbacks */
  93         void (*release)(struct video_device *vdev);
  94
  95         /* ioctl callbacks */
  96         const struct v4l2_ioctl_ops *ioctl_ops;
  97
  98         /* serialization lock */
  99         struct mutex *lock;
 100 };
 101
 102 /* dev to video-device */
 103 #define to_video_device(cd) container_of(cd, struct video_device, dev)
 104
 105 /* Register video devices. Note that if video_register_device fails,
 106    the release() callback of the video_device structure is *not* called, so
 107    the caller is responsible for freeing any data. Usually that means that
 108    you call video_device_release() on failure. */
 109 int __must_check video_register_device(struct video_device *vdev, int type, int nr);
 110
 111 /* Same as video_register_device, but no warning is issued if the desired
 112    device node number was already in use. */
 113 int __must_check video_register_device_no_warn(struct video_device *vdev, int type, int nr);
 114
 115 /* Unregister video devices. Will do nothing if vdev == NULL or
 116    video_is_registered() returns false. */
 117 void video_unregister_device(struct video_device *vdev);
 118
 119 /* helper functions to alloc/release struct video_device, the
 120    latter can also be used for video_device->release(). */
 121 struct video_device * __must_check video_device_alloc(void);
 122
 123 /* this release function frees the vdev pointer */
 124 void video_device_release(struct video_device *vdev);
 125
 126 /* this release function does nothing, use when the video_device is a
 127    static global struct. Note that having a static video_device is
 128    a dubious construction at best. */
 129 void video_device_release_empty(struct video_device *vdev);
 130
 131 /* helper functions to access driver private data. */
 132 static inline void *video_get_drvdata(struct video_device *vdev)
 133 {
 134         return dev_get_drvdata(&vdev->dev);
 135 }
 136
 137 static inline void video_set_drvdata(struct video_device *vdev, void *data)
 138 {
 139         dev_set_drvdata(&vdev->dev, data);
 140 }
 141
 142 struct video_device *video_devdata(struct file *file);
 143
 144 /* Combine video_get_drvdata and video_devdata as this is
 145    used very often. */
 146 static inline void *video_drvdata(struct file *file)
 147 {
 148         return video_get_drvdata(video_devdata(file));
 149 }
 150
 151 static inline const char *video_device_node_name(struct video_device *vdev)
 152 {
 153         return dev_name(&vdev->dev);
 154 }
 155
 156 static inline int video_is_registered(struct video_device *vdev)
 157 {
 158         return test_bit(V4L2_FL_REGISTERED, &vdev->flags);
 159 }
 160
 161 #endif /* _V4L2_DEV_H */