linux/include/media/v4l2-dev.h
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   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/* If ioctl core locking is in use, then apply that also to all
  43   file operations. Don't use this flag in new drivers! */
  44#define V4L2_FL_LOCK_ALL_FOPS   (3)
  45
  46/* Priority helper functions */
  47
  48struct v4l2_prio_state {
  49        atomic_t prios[4];
  50};
  51
  52void v4l2_prio_init(struct v4l2_prio_state *global);
  53int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
  54                     enum v4l2_priority new);
  55void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local);
  56void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local);
  57enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global);
  58int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local);
  59
  60
  61struct v4l2_file_operations {
  62        struct module *owner;
  63        ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
  64        ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
  65        unsigned int (*poll) (struct file *, struct poll_table_struct *);
  66        long (*ioctl) (struct file *, unsigned int, unsigned long);
  67        long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
  68#ifdef CONFIG_COMPAT
  69        long (*compat_ioctl32) (struct file *, unsigned int, unsigned long);
  70#endif
  71        unsigned long (*get_unmapped_area) (struct file *, unsigned long,
  72                                unsigned long, unsigned long, unsigned long);
  73        int (*mmap) (struct file *, struct vm_area_struct *);
  74        int (*open) (struct file *);
  75        int (*release) (struct file *);
  76};
  77
  78/*
  79 * Newer version of video_device, handled by videodev2.c
  80 *      This version moves redundant code from video device code to
  81 *      the common handler
  82 */
  83
  84struct video_device
  85{
  86#if defined(CONFIG_MEDIA_CONTROLLER)
  87        struct media_entity entity;
  88#endif
  89        /* device ops */
  90        const struct v4l2_file_operations *fops;
  91
  92        /* sysfs */
  93        struct device dev;              /* v4l device */
  94        struct cdev *cdev;              /* character device */
  95
  96        /* Set either parent or v4l2_dev if your driver uses v4l2_device */
  97        struct device *parent;          /* device parent */
  98        struct v4l2_device *v4l2_dev;   /* v4l2_device parent */
  99
 100        /* Control handler associated with this device node. May be NULL. */
 101        struct v4l2_ctrl_handler *ctrl_handler;
 102
 103        /* vb2_queue associated with this device node. May be NULL. */
 104        struct vb2_queue *queue;
 105
 106        /* Priority state. If NULL, then v4l2_dev->prio will be used. */
 107        struct v4l2_prio_state *prio;
 108
 109        /* device info */
 110        char name[32];
 111        int vfl_type;
 112        /* 'minor' is set to -1 if the registration failed */
 113        int minor;
 114        u16 num;
 115        /* use bitops to set/clear/test flags */
 116        unsigned long flags;
 117        /* attribute to differentiate multiple indices on one physical device */
 118        int index;
 119
 120        /* V4L2 file handles */
 121        spinlock_t              fh_lock; /* Lock for all v4l2_fhs */
 122        struct list_head        fh_list; /* List of struct v4l2_fh */
 123
 124        int debug;                      /* Activates debug level*/
 125
 126        /* Video standard vars */
 127        v4l2_std_id tvnorms;            /* Supported tv norms */
 128        v4l2_std_id current_norm;       /* Current tvnorm */
 129
 130        /* callbacks */
 131        void (*release)(struct video_device *vdev);
 132
 133        /* ioctl callbacks */
 134        const struct v4l2_ioctl_ops *ioctl_ops;
 135        DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE);
 136
 137        /* serialization lock */
 138        DECLARE_BITMAP(disable_locking, BASE_VIDIOC_PRIVATE);
 139        struct mutex *lock;
 140};
 141
 142#define media_entity_to_video_device(__e) \
 143        container_of(__e, struct video_device, entity)
 144/* dev to video-device */
 145#define to_video_device(cd) container_of(cd, struct video_device, dev)
 146
 147int __must_check __video_register_device(struct video_device *vdev, int type,
 148                int nr, int warn_if_nr_in_use, struct module *owner);
 149
 150/* Register video devices. Note that if video_register_device fails,
 151   the release() callback of the video_device structure is *not* called, so
 152   the caller is responsible for freeing any data. Usually that means that
 153   you call video_device_release() on failure. */
 154static inline int __must_check video_register_device(struct video_device *vdev,
 155                int type, int nr)
 156{
 157        return __video_register_device(vdev, type, nr, 1, vdev->fops->owner);
 158}
 159
 160/* Same as video_register_device, but no warning is issued if the desired
 161   device node number was already in use. */
 162static inline int __must_check video_register_device_no_warn(
 163                struct video_device *vdev, int type, int nr)
 164{
 165        return __video_register_device(vdev, type, nr, 0, vdev->fops->owner);
 166}
 167
 168/* Unregister video devices. Will do nothing if vdev == NULL or
 169   video_is_registered() returns false. */
 170void video_unregister_device(struct video_device *vdev);
 171
 172/* helper functions to alloc/release struct video_device, the
 173   latter can also be used for video_device->release(). */
 174struct video_device * __must_check video_device_alloc(void);
 175
 176/* this release function frees the vdev pointer */
 177void video_device_release(struct video_device *vdev);
 178
 179/* this release function does nothing, use when the video_device is a
 180   static global struct. Note that having a static video_device is
 181   a dubious construction at best. */
 182void video_device_release_empty(struct video_device *vdev);
 183
 184/* returns true if cmd is a known V4L2 ioctl */
 185bool v4l2_is_known_ioctl(unsigned int cmd);
 186
 187/* mark that this command shouldn't use core locking */
 188static inline void v4l2_disable_ioctl_locking(struct video_device *vdev, unsigned int cmd)
 189{
 190        if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE)
 191                set_bit(_IOC_NR(cmd), vdev->disable_locking);
 192}
 193
 194/* Mark that this command isn't implemented. This must be called before
 195   video_device_register. See also the comments in determine_valid_ioctls().
 196   This function allows drivers to provide just one v4l2_ioctl_ops struct, but
 197   disable ioctls based on the specific card that is actually found. */
 198static inline void v4l2_disable_ioctl(struct video_device *vdev, unsigned int cmd)
 199{
 200        if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE)
 201                set_bit(_IOC_NR(cmd), vdev->valid_ioctls);
 202}
 203
 204/* helper functions to access driver private data. */
 205static inline void *video_get_drvdata(struct video_device *vdev)
 206{
 207        return dev_get_drvdata(&vdev->dev);
 208}
 209
 210static inline void video_set_drvdata(struct video_device *vdev, void *data)
 211{
 212        dev_set_drvdata(&vdev->dev, data);
 213}
 214
 215struct video_device *video_devdata(struct file *file);
 216
 217/* Combine video_get_drvdata and video_devdata as this is
 218   used very often. */
 219static inline void *video_drvdata(struct file *file)
 220{
 221        return video_get_drvdata(video_devdata(file));
 222}
 223
 224static inline const char *video_device_node_name(struct video_device *vdev)
 225{
 226        return dev_name(&vdev->dev);
 227}
 228
 229static inline int video_is_registered(struct video_device *vdev)
 230{
 231        return test_bit(V4L2_FL_REGISTERED, &vdev->flags);
 232}
 233
 234#endif /* _V4L2_DEV_H */
 235
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