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
  29/* Is this a receiver, transmitter or mem-to-mem? */
  30/* Ignored for VFL_TYPE_SUBDEV. */
  31#define VFL_DIR_RX              0
  32#define VFL_DIR_TX              1
  33#define VFL_DIR_M2M             2
  34
  35struct v4l2_ioctl_callbacks;
  36struct video_device;
  37struct v4l2_device;
  38struct v4l2_ctrl_handler;
  39
  40/* Flag to mark the video_device struct as registered.
  41   Drivers can clear this flag if they want to block all future
  42   device access. It is cleared by video_unregister_device. */
  43#define V4L2_FL_REGISTERED      (0)
  44/* file->private_data points to struct v4l2_fh */
  45#define V4L2_FL_USES_V4L2_FH    (1)
  46/* Use the prio field of v4l2_fh for core priority checking */
  47#define V4L2_FL_USE_FH_PRIO     (2)
  48
  49/* Priority helper functions */
  50
  51struct v4l2_prio_state {
  52        atomic_t prios[4];
  53};
  54
  55void v4l2_prio_init(struct v4l2_prio_state *global);
  56int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
  57                     enum v4l2_priority new);
  58void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local);
  59void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local);
  60enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global);
  61int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local);
  62
  63
  64struct v4l2_file_operations {
  65        struct module *owner;
  66        ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
  67        ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
  68        unsigned int (*poll) (struct file *, struct poll_table_struct *);
  69        long (*ioctl) (struct file *, unsigned int, unsigned long);
  70        long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
  71#ifdef CONFIG_COMPAT
  72        long (*compat_ioctl32) (struct file *, unsigned int, unsigned long);
  73#endif
  74        unsigned long (*get_unmapped_area) (struct file *, unsigned long,
  75                                unsigned long, unsigned long, unsigned long);
  76        int (*mmap) (struct file *, struct vm_area_struct *);
  77        int (*open) (struct file *);
  78        int (*release) (struct file *);
  79};
  80
  81/*
  82 * Newer version of video_device, handled by videodev2.c
  83 *      This version moves redundant code from video device code to
  84 *      the common handler
  85 */
  86
  87struct video_device
  88{
  89#if defined(CONFIG_MEDIA_CONTROLLER)
  90        struct media_entity entity;
  91#endif
  92        /* device ops */
  93        const struct v4l2_file_operations *fops;
  94
  95        /* sysfs */
  96        struct device dev;              /* v4l device */
  97        struct cdev *cdev;              /* character device */
  98
  99        /* Set either parent or v4l2_dev if your driver uses v4l2_device */
 100        struct device *parent;          /* device parent */
 101        struct v4l2_device *v4l2_dev;   /* v4l2_device parent */
 102
 103        /* Control handler associated with this device node. May be NULL. */
 104        struct v4l2_ctrl_handler *ctrl_handler;
 105
 106        /* vb2_queue associated with this device node. May be NULL. */
 107        struct vb2_queue *queue;
 108
 109        /* Priority state. If NULL, then v4l2_dev->prio will be used. */
 110        struct v4l2_prio_state *prio;
 111
 112        /* device info */
 113        char name[32];
 114        int vfl_type;   /* device type */
 115        int vfl_dir;    /* receiver, transmitter or m2m */
 116        /* 'minor' is set to -1 if the registration failed */
 117        int minor;
 118        u16 num;
 119        /* use bitops to set/clear/test flags */
 120        unsigned long flags;
 121        /* attribute to differentiate multiple indices on one physical device */
 122        int index;
 123
 124        /* V4L2 file handles */
 125        spinlock_t              fh_lock; /* Lock for all v4l2_fhs */
 126        struct list_head        fh_list; /* List of struct v4l2_fh */
 127
 128        int debug;                      /* Activates debug level*/
 129
 130        /* Video standard vars */
 131        v4l2_std_id tvnorms;            /* Supported tv norms */
 132        v4l2_std_id current_norm;       /* Current tvnorm */
 133
 134        /* callbacks */
 135        void (*release)(struct video_device *vdev);
 136
 137        /* ioctl callbacks */
 138        const struct v4l2_ioctl_ops *ioctl_ops;
 139        DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE);
 140
 141        /* serialization lock */
 142        DECLARE_BITMAP(disable_locking, BASE_VIDIOC_PRIVATE);
 143        struct mutex *lock;
 144};
 145
 146#define media_entity_to_video_device(__e) \
 147        container_of(__e, struct video_device, entity)
 148/* dev to video-device */
 149#define to_video_device(cd) container_of(cd, struct video_device, dev)
 150
 151int __must_check __video_register_device(struct video_device *vdev, int type,
 152                int nr, int warn_if_nr_in_use, struct module *owner);
 153
 154/* Register video devices. Note that if video_register_device fails,
 155   the release() callback of the video_device structure is *not* called, so
 156   the caller is responsible for freeing any data. Usually that means that
 157   you call video_device_release() on failure. */
 158static inline int __must_check video_register_device(struct video_device *vdev,
 159                int type, int nr)
 160{
 161        return __video_register_device(vdev, type, nr, 1, vdev->fops->owner);
 162}
 163
 164/* Same as video_register_device, but no warning is issued if the desired
 165   device node number was already in use. */
 166static inline int __must_check video_register_device_no_warn(
 167                struct video_device *vdev, int type, int nr)
 168{
 169        return __video_register_device(vdev, type, nr, 0, vdev->fops->owner);
 170}
 171
 172/* Unregister video devices. Will do nothing if vdev == NULL or
 173   video_is_registered() returns false. */
 174void video_unregister_device(struct video_device *vdev);
 175
 176/* helper functions to alloc/release struct video_device, the
 177   latter can also be used for video_device->release(). */
 178struct video_device * __must_check video_device_alloc(void);
 179
 180/* this release function frees the vdev pointer */
 181void video_device_release(struct video_device *vdev);
 182
 183/* this release function does nothing, use when the video_device is a
 184   static global struct. Note that having a static video_device is
 185   a dubious construction at best. */
 186void video_device_release_empty(struct video_device *vdev);
 187
 188/* returns true if cmd is a known V4L2 ioctl */
 189bool v4l2_is_known_ioctl(unsigned int cmd);
 190
 191/* mark that this command shouldn't use core locking */
 192static inline void v4l2_disable_ioctl_locking(struct video_device *vdev, unsigned int cmd)
 193{
 194        if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE)
 195                set_bit(_IOC_NR(cmd), vdev->disable_locking);
 196}
 197
 198/* Mark that this command isn't implemented. This must be called before
 199   video_device_register. See also the comments in determine_valid_ioctls().
 200   This function allows drivers to provide just one v4l2_ioctl_ops struct, but
 201   disable ioctls based on the specific card that is actually found. */
 202static inline void v4l2_disable_ioctl(struct video_device *vdev, unsigned int cmd)
 203{
 204        if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE)
 205                set_bit(_IOC_NR(cmd), vdev->valid_ioctls);
 206}
 207
 208/* helper functions to access driver private data. */
 209static inline void *video_get_drvdata(struct video_device *vdev)
 210{
 211        return dev_get_drvdata(&vdev->dev);
 212}
 213
 214static inline void video_set_drvdata(struct video_device *vdev, void *data)
 215{
 216        dev_set_drvdata(&vdev->dev, data);
 217}
 218
 219struct video_device *video_devdata(struct file *file);
 220
 221/* Combine video_get_drvdata and video_devdata as this is
 222   used very often. */
 223static inline void *video_drvdata(struct file *file)
 224{
 225        return video_get_drvdata(video_devdata(file));
 226}
 227
 228static inline const char *video_device_node_name(struct video_device *vdev)
 229{
 230        return dev_name(&vdev->dev);
 231}
 232
 233static inline int video_is_registered(struct video_device *vdev)
 234{
 235        return test_bit(V4L2_FL_REGISTERED, &vdev->flags);
 236}
 237
 238#endif /* _V4L2_DEV_H */
 239
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