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 /* 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
  45 struct v4l2_prio_state {
  46         atomic_t prios[4];
  47 };
  48
  49 void v4l2_prio_init(struct v4l2_prio_state *global);
  50 int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
  51                      enum v4l2_priority new);
  52 void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local);
  53 void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local);
  54 enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global);
  55 int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local);
  56
  57
  58 struct 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
  78 struct 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
 136 int __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. */
 143 static 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. */
 151 static 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. */
 159 void 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(). */
 163 struct video_device * __must_check video_device_alloc(void);
 164
 165 /* this release function frees the vdev pointer */
 166 void 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. */
 171 void video_device_release_empty(struct video_device *vdev);
 172
 173 /* helper functions to access driver private data. */
 174 static inline void *video_get_drvdata(struct video_device *vdev)
 175 {
 176         return dev_get_drvdata(&vdev->dev);
 177 }
 178
 179 static inline void video_set_drvdata(struct video_device *vdev, void *data)
 180 {
 181         dev_set_drvdata(&vdev->dev, data);
 182 }
 183
 184 struct video_device *video_devdata(struct file *file);
 185
 186 /* Combine video_get_drvdata and video_devdata as this is
 187    used very often. */
 188 static inline void *video_drvdata(struct file *file)
 189 {
 190         return video_get_drvdata(video_devdata(file));
 191 }
 192
 193 static inline const char *video_device_node_name(struct video_device *vdev)
 194 {
 195         return dev_name(&vdev->dev);
 196 }
 197
 198 static 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 */