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 /* 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
  35 struct v4l2_ioctl_callbacks;
  36 struct video_device;
  37 struct v4l2_device;
  38 struct 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
  51 struct v4l2_prio_state {
  52         atomic_t prios[4];
  53 };
  54
  55 void v4l2_prio_init(struct v4l2_prio_state *global);
  56 int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
  57                      enum v4l2_priority new);
  58 void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local);
  59 void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local);
  60 enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global);
  61 int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local);
  62
  63
  64 struct 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
  87 struct 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         struct v4l2_device *v4l2_dev;   /* v4l2_device parent */
 100         /* Only set parent if that can't be deduced from v4l2_dev */
 101         struct device *dev_parent;      /* 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
 133         /* callbacks */
 134         void (*release)(struct video_device *vdev);
 135
 136         /* ioctl callbacks */
 137         const struct v4l2_ioctl_ops *ioctl_ops;
 138         DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE);
 139
 140         /* serialization lock */
 141         DECLARE_BITMAP(disable_locking, BASE_VIDIOC_PRIVATE);
 142         struct mutex *lock;
 143 };
 144
 145 #define media_entity_to_video_device(__e) \
 146         container_of(__e, struct video_device, entity)
 147 /* dev to video-device */
 148 #define to_video_device(cd) container_of(cd, struct video_device, dev)
 149
 150 int __must_check __video_register_device(struct video_device *vdev, int type,
 151                 int nr, int warn_if_nr_in_use, struct module *owner);
 152
 153 /* Register video devices. Note that if video_register_device fails,
 154    the release() callback of the video_device structure is *not* called, so
 155    the caller is responsible for freeing any data. Usually that means that
 156    you call video_device_release() on failure. */
 157 static inline int __must_check video_register_device(struct video_device *vdev,
 158                 int type, int nr)
 159 {
 160         return __video_register_device(vdev, type, nr, 1, vdev->fops->owner);
 161 }
 162
 163 /* Same as video_register_device, but no warning is issued if the desired
 164    device node number was already in use. */
 165 static inline int __must_check video_register_device_no_warn(
 166                 struct video_device *vdev, int type, int nr)
 167 {
 168         return __video_register_device(vdev, type, nr, 0, vdev->fops->owner);
 169 }
 170
 171 /* Unregister video devices. Will do nothing if vdev == NULL or
 172    video_is_registered() returns false. */
 173 void video_unregister_device(struct video_device *vdev);
 174
 175 /* helper functions to alloc/release struct video_device, the
 176    latter can also be used for video_device->release(). */
 177 struct video_device * __must_check video_device_alloc(void);
 178
 179 /* this release function frees the vdev pointer */
 180 void video_device_release(struct video_device *vdev);
 181
 182 /* this release function does nothing, use when the video_device is a
 183    static global struct. Note that having a static video_device is
 184    a dubious construction at best. */
 185 void video_device_release_empty(struct video_device *vdev);
 186
 187 /* returns true if cmd is a known V4L2 ioctl */
 188 bool v4l2_is_known_ioctl(unsigned int cmd);
 189
 190 /* mark that this command shouldn't use core locking */
 191 static inline void v4l2_disable_ioctl_locking(struct video_device *vdev, unsigned int cmd)
 192 {
 193         if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE)
 194                 set_bit(_IOC_NR(cmd), vdev->disable_locking);
 195 }
 196
 197 /* Mark that this command isn't implemented. This must be called before
 198    video_device_register. See also the comments in determine_valid_ioctls().
 199    This function allows drivers to provide just one v4l2_ioctl_ops struct, but
 200    disable ioctls based on the specific card that is actually found. */
 201 static inline void v4l2_disable_ioctl(struct video_device *vdev, unsigned int cmd)
 202 {
 203         if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE)
 204                 set_bit(_IOC_NR(cmd), vdev->valid_ioctls);
 205 }
 206
 207 /* helper functions to access driver private data. */
 208 static inline void *video_get_drvdata(struct video_device *vdev)
 209 {
 210         return dev_get_drvdata(&vdev->dev);
 211 }
 212
 213 static inline void video_set_drvdata(struct video_device *vdev, void *data)
 214 {
 215         dev_set_drvdata(&vdev->dev, data);
 216 }
 217
 218 struct video_device *video_devdata(struct file *file);
 219
 220 /* Combine video_get_drvdata and video_devdata as this is
 221    used very often. */
 222 static inline void *video_drvdata(struct file *file)
 223 {
 224         return video_get_drvdata(video_devdata(file));
 225 }
 226
 227 static inline const char *video_device_node_name(struct video_device *vdev)
 228 {
 229         return dev_name(&vdev->dev);
 230 }
 231
 232 static inline int video_is_registered(struct video_device *vdev)
 233 {
 234         return test_bit(V4L2_FL_REGISTERED, &vdev->flags);
 235 }
 236
 237 #endif /* _V4L2_DEV_H */