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#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
  29struct v4l2_ioctl_callbacks;
  30struct video_device;
  31struct v4l2_device;
  32struct 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/* file->private_data points to struct v4l2_fh */
  39#define V4L2_FL_USES_V4L2_FH    (1)
  40/* Use the prio field of v4l2_fh for core priority checking */
  41#define V4L2_FL_USE_FH_PRIO     (2)
  42
  43/* Priority helper functions */
  44
  45struct v4l2_prio_state {
  46        atomic_t prios[4];
  47};
  48
  49void v4l2_prio_init(struct v4l2_prio_state *global);
  50int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
  51                     enum v4l2_priority new);
  52void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local);
  53void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local);
  54enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global);
  55int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local);
  56
  57
  58struct v4l2_file_operations {
  59        struct module *owner;
  60        ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
  61        ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
  62        unsigned int (*poll) (struct file *, struct poll_table_struct *);
  63        long (*ioctl) (struct file *, unsigned int, unsigned long);
  64        long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
  65        unsigned long (*get_unmapped_area) (struct file *, unsigned long,
  66                                unsigned long, unsigned long, unsigned long);
  67        int (*mmap) (struct file *, struct vm_area_struct *);
  68        int (*open) (struct file *);
  69        int (*release) (struct file *);
  70};
  71
  72/*
  73 * Newer version of video_device, handled by videodev2.c
  74 *      This version moves redundant code from video device code to
  75 *      the common handler
  76 */
  77
  78struct video_device
  79{
  80#if defined(CONFIG_MEDIA_CONTROLLER)
  81        struct media_entity entity;
  82#endif
  83        /* device ops */
  84        const struct v4l2_file_operations *fops;
  85
  86        /* sysfs */
  87        struct device dev;              /* v4l device */
  88        struct cdev *cdev;              /* character device */
  89
  90        /* Set either parent or v4l2_dev if your driver uses v4l2_device */
  91        struct device *parent;          /* device parent */
  92        struct v4l2_device *v4l2_dev;   /* v4l2_device parent */
  93
  94        /* Control handler associated with this device node. May be NULL. */
  95        struct v4l2_ctrl_handler *ctrl_handler;
  96
  97        /* Priority state. If NULL, then v4l2_dev->prio will be used. */
  98        struct v4l2_prio_state *prio;
  99
 100        /* device info */
 101        char name[32];
 102        int vfl_type;
 103        /* 'minor' is set to -1 if the registration failed */
 104        int minor;
 105        u16 num;
 106        /* use bitops to set/clear/test flags */
 107        unsigned long flags;
 108        /* attribute to differentiate multiple indices on one physical device */
 109        int index;
 110
 111        /* V4L2 file handles */
 112        spinlock_t              fh_lock; /* Lock for all v4l2_fhs */
 113        struct list_head        fh_list; /* List of struct v4l2_fh */
 114
 115        int debug;                      /* Activates debug level*/
 116
 117        /* Video standard vars */
 118        v4l2_std_id tvnorms;            /* Supported tv norms */
 119        v4l2_std_id current_norm;       /* Current tvnorm */
 120
 121        /* callbacks */
 122        void (*release)(struct video_device *vdev);
 123
 124        /* ioctl callbacks */
 125        const struct v4l2_ioctl_ops *ioctl_ops;
 126
 127        /* serialization lock */
 128        struct mutex *lock;
 129};
 130
 131#define media_entity_to_video_device(__e) \
 132        container_of(__e, struct video_device, entity)
 133/* dev to video-device */
 134#define to_video_device(cd) container_of(cd, struct video_device, dev)
 135
 136int __must_check __video_register_device(struct video_device *vdev, int type,
 137                int nr, int warn_if_nr_in_use, struct module *owner);
 138
 139/* Register video devices. Note that if video_register_device fails,
 140   the release() callback of the video_device structure is *not* called, so
 141   the caller is responsible for freeing any data. Usually that means that
 142   you call video_device_release() on failure. */
 143static inline int __must_check video_register_device(struct video_device *vdev,
 144                int type, int nr)
 145{
 146        return __video_register_device(vdev, type, nr, 1, vdev->fops->owner);
 147}
 148
 149/* Same as video_register_device, but no warning is issued if the desired
 150   device node number was already in use. */
 151static inline int __must_check video_register_device_no_warn(
 152                struct video_device *vdev, int type, int nr)
 153{
 154        return __video_register_device(vdev, type, nr, 0, vdev->fops->owner);
 155}
 156
 157/* Unregister video devices. Will do nothing if vdev == NULL or
 158   video_is_registered() returns false. */
 159void video_unregister_device(struct video_device *vdev);
 160
 161/* helper functions to alloc/release struct video_device, the
 162   latter can also be used for video_device->release(). */
 163struct video_device * __must_check video_device_alloc(void);
 164
 165/* this release function frees the vdev pointer */
 166void video_device_release(struct video_device *vdev);
 167
 168/* this release function does nothing, use when the video_device is a
 169   static global struct. Note that having a static video_device is
 170   a dubious construction at best. */
 171void video_device_release_empty(struct video_device *vdev);
 172
 173/* helper functions to access driver private data. */
 174static inline void *video_get_drvdata(struct video_device *vdev)
 175{
 176        return dev_get_drvdata(&vdev->dev);
 177}
 178
 179static inline void video_set_drvdata(struct video_device *vdev, void *data)
 180{
 181        dev_set_drvdata(&vdev->dev, data);
 182}
 183
 184struct video_device *video_devdata(struct file *file);
 185
 186/* Combine video_get_drvdata and video_devdata as this is
 187   used very often. */
 188static inline void *video_drvdata(struct file *file)
 189{
 190        return video_get_drvdata(video_devdata(file));
 191}
 192
 193static inline const char *video_device_node_name(struct video_device *vdev)
 194{
 195        return dev_name(&vdev->dev);
 196}
 197
 198static inline int video_is_registered(struct video_device *vdev)
 199{
 200        return test_bit(V4L2_FL_REGISTERED, &vdev->flags);
 201}
 202
 203#endif /* _V4L2_DEV_H */
 204