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