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
  29 struct v4l2_ioctl_callbacks;
  30 struct video_device;
  31 struct v4l2_device;
  32 struct 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 #define V4L2_FL_USES_V4L2_FH    (1)
  39
  40 struct v4l2_file_operations {
  41         struct module *owner;
  42         ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
  43         ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
  44         unsigned int (*poll) (struct file *, struct poll_table_struct *);
  45         long (*ioctl) (struct file *, unsigned int, unsigned long);
  46         long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
  47         int (*mmap) (struct file *, struct vm_area_struct *);
  48         int (*open) (struct file *);
  49         int (*release) (struct file *);
  50 };
  51
  52 /*
  53  * Newer version of video_device, handled by videodev2.c
  54  *      This version moves redundant code from video device code to
  55  *      the common handler
  56  */
  57
  58 struct video_device
  59 {
  60 #if defined(CONFIG_MEDIA_CONTROLLER)
  61         struct media_entity entity;
  62 #endif
  63         /* device ops */
  64         const struct v4l2_file_operations *fops;
  65
  66         /* sysfs */
  67         struct device dev;              /* v4l device */
  68         struct cdev *cdev;              /* character device */
  69
  70         /* Set either parent or v4l2_dev if your driver uses v4l2_device */
  71         struct device *parent;          /* device parent */
  72         struct v4l2_device *v4l2_dev;   /* v4l2_device parent */
  73
  74         /* Control handler associated with this device node. May be NULL. */
  75         struct v4l2_ctrl_handler *ctrl_handler;
  76
  77         /* device info */
  78         char name[32];
  79         int vfl_type;
  80         /* 'minor' is set to -1 if the registration failed */
  81         int minor;
  82         u16 num;
  83         /* use bitops to set/clear/test flags */
  84         unsigned long flags;
  85         /* attribute to differentiate multiple indices on one physical device */
  86         int index;
  87
  88         /* V4L2 file handles */
  89         spinlock_t              fh_lock; /* Lock for all v4l2_fhs */
  90         struct list_head        fh_list; /* List of struct v4l2_fh */
  91
  92         int debug;                      /* Activates debug level*/
  93
  94         /* Video standard vars */
  95         v4l2_std_id tvnorms;            /* Supported tv norms */
  96         v4l2_std_id current_norm;       /* Current tvnorm */
  97
  98         /* callbacks */
  99         void (*release)(struct video_device *vdev);
 100
 101         /* ioctl callbacks */
 102         const struct v4l2_ioctl_ops *ioctl_ops;
 103
 104         /* serialization lock */
 105         struct mutex *lock;
 106 };
 107
 108 #define media_entity_to_video_device(entity) \
 109         container_of(entity, struct video_device, entity)
 110 /* dev to video-device */
 111 #define to_video_device(cd) container_of(cd, struct video_device, dev)
 112
 113 int __must_check __video_register_device(struct video_device *vdev, int type,
 114                 int nr, int warn_if_nr_in_use, struct module *owner);
 115
 116 /* Register video devices. Note that if video_register_device fails,
 117    the release() callback of the video_device structure is *not* called, so
 118    the caller is responsible for freeing any data. Usually that means that
 119    you call video_device_release() on failure. */
 120 static inline int __must_check video_register_device(struct video_device *vdev,
 121                 int type, int nr)
 122 {
 123         return __video_register_device(vdev, type, nr, 1, vdev->fops->owner);
 124 }
 125
 126 /* Same as video_register_device, but no warning is issued if the desired
 127    device node number was already in use. */
 128 static inline int __must_check video_register_device_no_warn(
 129                 struct video_device *vdev, int type, int nr)
 130 {
 131         return __video_register_device(vdev, type, nr, 0, vdev->fops->owner);
 132 }
 133
 134 /* Unregister video devices. Will do nothing if vdev == NULL or
 135    video_is_registered() returns false. */
 136 void video_unregister_device(struct video_device *vdev);
 137
 138 /* helper functions to alloc/release struct video_device, the
 139    latter can also be used for video_device->release(). */
 140 struct video_device * __must_check video_device_alloc(void);
 141
 142 /* this release function frees the vdev pointer */
 143 void video_device_release(struct video_device *vdev);
 144
 145 /* this release function does nothing, use when the video_device is a
 146    static global struct. Note that having a static video_device is
 147    a dubious construction at best. */
 148 void video_device_release_empty(struct video_device *vdev);
 149
 150 /* helper functions to access driver private data. */
 151 static inline void *video_get_drvdata(struct video_device *vdev)
 152 {
 153         return dev_get_drvdata(&vdev->dev);
 154 }
 155
 156 static inline void video_set_drvdata(struct video_device *vdev, void *data)
 157 {
 158         dev_set_drvdata(&vdev->dev, data);
 159 }
 160
 161 struct video_device *video_devdata(struct file *file);
 162
 163 /* Combine video_get_drvdata and video_devdata as this is
 164    used very often. */
 165 static inline void *video_drvdata(struct file *file)
 166 {
 167         return video_get_drvdata(video_devdata(file));
 168 }
 169
 170 static inline const char *video_device_node_name(struct video_device *vdev)
 171 {
 172         return dev_name(&vdev->dev);
 173 }
 174
 175 static inline int video_is_registered(struct video_device *vdev)
 176 {
 177         return test_bit(V4L2_FL_REGISTERED, &vdev->flags);
 178 }
 179
 180 #endif /* _V4L2_DEV_H */