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 /* 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
  48 struct v4l2_prio_state {
  49         atomic_t prios[4];
  50 };
  51
  52 void v4l2_prio_init(struct v4l2_prio_state *global);
  53 int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
  54                      enum v4l2_priority new);
  55 void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local);
  56 void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local);
  57 enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global);
  58 int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local);
  59
  60
  61 struct 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
  84 struct 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
 147 int __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. */
 154 static 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. */
 162 static 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. */
 170 void 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(). */
 174 struct video_device * __must_check video_device_alloc(void);
 175
 176 /* this release function frees the vdev pointer */
 177 void 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. */
 182 void video_device_release_empty(struct video_device *vdev);
 183
 184 /* returns true if cmd is a known V4L2 ioctl */
 185 bool v4l2_is_known_ioctl(unsigned int cmd);
 186
 187 /* mark that this command shouldn't use core locking */
 188 static 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. */
 198 static 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. */
 205 static inline void *video_get_drvdata(struct video_device *vdev)
 206 {
 207         return dev_get_drvdata(&vdev->dev);
 208 }
 209
 210 static inline void video_set_drvdata(struct video_device *vdev, void *data)
 211 {
 212         dev_set_drvdata(&vdev->dev, data);
 213 }
 214
 215 struct video_device *video_devdata(struct file *file);
 216
 217 /* Combine video_get_drvdata and video_devdata as this is
 218    used very often. */
 219 static inline void *video_drvdata(struct file *file)
 220 {
 221         return video_get_drvdata(video_devdata(file));
 222 }
 223
 224 static inline const char *video_device_node_name(struct video_device *vdev)
 225 {
 226         return dev_name(&vdev->dev);
 227 }
 228
 229 static 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 */