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_SDR            4
  28 #define VFL_TYPE_MAX            5
  29
  30 /* Is this a receiver, transmitter or mem-to-mem? */
  31 /* Ignored for VFL_TYPE_SUBDEV. */
  32 #define VFL_DIR_RX              0
  33 #define VFL_DIR_TX              1
  34 #define VFL_DIR_M2M             2
  35
  36 struct v4l2_ioctl_callbacks;
  37 struct video_device;
  38 struct v4l2_device;
  39 struct v4l2_ctrl_handler;
  40
  41 /* Flag to mark the video_device struct as registered.
  42    Drivers can clear this flag if they want to block all future
  43    device access. It is cleared by video_unregister_device. */
  44 #define V4L2_FL_REGISTERED      (0)
  45 /* file->private_data points to struct v4l2_fh */
  46 #define V4L2_FL_USES_V4L2_FH    (1)
  47
  48 /* Priority helper functions */
  49
  50 struct v4l2_prio_state {
  51         atomic_t prios[4];
  52 };
  53
  54 void v4l2_prio_init(struct v4l2_prio_state *global);
  55 int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
  56                      enum v4l2_priority new);
  57 void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local);
  58 void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local);
  59 enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global);
  60 int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local);
  61
  62
  63 struct v4l2_file_operations {
  64         struct module *owner;
  65         ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
  66         ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
  67         unsigned int (*poll) (struct file *, struct poll_table_struct *);
  68         long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
  69 #ifdef CONFIG_COMPAT
  70         long (*compat_ioctl32) (struct file *, unsigned int, unsigned long);
  71 #endif
  72         unsigned long (*get_unmapped_area) (struct file *, unsigned long,
  73                                 unsigned long, unsigned long, unsigned long);
  74         int (*mmap) (struct file *, struct vm_area_struct *);
  75         int (*open) (struct file *);
  76         int (*release) (struct file *);
  77 };
  78
  79 /*
  80  * Newer version of video_device, handled by videodev2.c
  81  *      This version moves redundant code from video device code to
  82  *      the common handler
  83  */
  84
  85 struct video_device
  86 {
  87 #if defined(CONFIG_MEDIA_CONTROLLER)
  88         struct media_entity entity;
  89 #endif
  90         /* device ops */
  91         const struct v4l2_file_operations *fops;
  92
  93         /* sysfs */
  94         struct device dev;              /* v4l device */
  95         struct cdev *cdev;              /* character device */
  96
  97         struct v4l2_device *v4l2_dev;   /* v4l2_device parent */
  98         /* Only set parent if that can't be deduced from v4l2_dev */
  99         struct device *dev_parent;      /* device parent */
 100
 101         /* Control handler associated with this device node. May be NULL. */
 102         struct v4l2_ctrl_handler *ctrl_handler;
 103
 104         /* vb2_queue associated with this device node. May be NULL. */
 105         struct vb2_queue *queue;
 106
 107         /* Priority state. If NULL, then v4l2_dev->prio will be used. */
 108         struct v4l2_prio_state *prio;
 109
 110         /* device info */
 111         char name[32];
 112         int vfl_type;   /* device type */
 113         int vfl_dir;    /* receiver, transmitter or m2m */
 114         /* 'minor' is set to -1 if the registration failed */
 115         int minor;
 116         u16 num;
 117         /* use bitops to set/clear/test flags */
 118         unsigned long flags;
 119         /* attribute to differentiate multiple indices on one physical device */
 120         int index;
 121
 122         /* V4L2 file handles */
 123         spinlock_t              fh_lock; /* Lock for all v4l2_fhs */
 124         struct list_head        fh_list; /* List of struct v4l2_fh */
 125
 126         /* Internal device debug flags, not for use by drivers */
 127         int dev_debug;
 128
 129         /* Video standard vars */
 130         v4l2_std_id tvnorms;            /* Supported tv norms */
 131
 132         /* callbacks */
 133         void (*release)(struct video_device *vdev);
 134
 135         /* ioctl callbacks */
 136         const struct v4l2_ioctl_ops *ioctl_ops;
 137         DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE);
 138
 139         /* serialization lock */
 140         DECLARE_BITMAP(disable_locking, BASE_VIDIOC_PRIVATE);
 141         struct mutex *lock;
 142 };
 143
 144 #define media_entity_to_video_device(__e) \
 145         container_of(__e, struct video_device, entity)
 146 /* dev to video-device */
 147 #define to_video_device(cd) container_of(cd, struct video_device, dev)
 148
 149 int __must_check __video_register_device(struct video_device *vdev, int type,
 150                 int nr, int warn_if_nr_in_use, struct module *owner);
 151
 152 /* Register video devices. Note that if video_register_device fails,
 153    the release() callback of the video_device structure is *not* called, so
 154    the caller is responsible for freeing any data. Usually that means that
 155    you call video_device_release() on failure. */
 156 static inline int __must_check video_register_device(struct video_device *vdev,
 157                 int type, int nr)
 158 {
 159         return __video_register_device(vdev, type, nr, 1, vdev->fops->owner);
 160 }
 161
 162 /* Same as video_register_device, but no warning is issued if the desired
 163    device node number was already in use. */
 164 static inline int __must_check video_register_device_no_warn(
 165                 struct video_device *vdev, int type, int nr)
 166 {
 167         return __video_register_device(vdev, type, nr, 0, vdev->fops->owner);
 168 }
 169
 170 /* Unregister video devices. Will do nothing if vdev == NULL or
 171    video_is_registered() returns false. */
 172 void video_unregister_device(struct video_device *vdev);
 173
 174 /* helper functions to alloc/release struct video_device, the
 175    latter can also be used for video_device->release(). */
 176 struct video_device * __must_check video_device_alloc(void);
 177
 178 /* this release function frees the vdev pointer */
 179 void video_device_release(struct video_device *vdev);
 180
 181 /* this release function does nothing, use when the video_device is a
 182    static global struct. Note that having a static video_device is
 183    a dubious construction at best. */
 184 void video_device_release_empty(struct video_device *vdev);
 185
 186 /* returns true if cmd is a known V4L2 ioctl */
 187 bool v4l2_is_known_ioctl(unsigned int cmd);
 188
 189 /* mark that this command shouldn't use core locking */
 190 static inline void v4l2_disable_ioctl_locking(struct video_device *vdev, unsigned int cmd)
 191 {
 192         if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE)
 193                 set_bit(_IOC_NR(cmd), vdev->disable_locking);
 194 }
 195
 196 /* Mark that this command isn't implemented. This must be called before
 197    video_device_register. See also the comments in determine_valid_ioctls().
 198    This function allows drivers to provide just one v4l2_ioctl_ops struct, but
 199    disable ioctls based on the specific card that is actually found. */
 200 static inline void v4l2_disable_ioctl(struct video_device *vdev, unsigned int cmd)
 201 {
 202         if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE)
 203                 set_bit(_IOC_NR(cmd), vdev->valid_ioctls);
 204 }
 205
 206 /* helper functions to access driver private data. */
 207 static inline void *video_get_drvdata(struct video_device *vdev)
 208 {
 209         return dev_get_drvdata(&vdev->dev);
 210 }
 211
 212 static inline void video_set_drvdata(struct video_device *vdev, void *data)
 213 {
 214         dev_set_drvdata(&vdev->dev, data);
 215 }
 216
 217 struct video_device *video_devdata(struct file *file);
 218
 219 /* Combine video_get_drvdata and video_devdata as this is
 220    used very often. */
 221 static inline void *video_drvdata(struct file *file)
 222 {
 223         return video_get_drvdata(video_devdata(file));
 224 }
 225
 226 static inline const char *video_device_node_name(struct video_device *vdev)
 227 {
 228         return dev_name(&vdev->dev);
 229 }
 230
 231 static inline int video_is_registered(struct video_device *vdev)
 232 {
 233         return test_bit(V4L2_FL_REGISTERED, &vdev->flags);
 234 }
 235
 236 #endif /* _V4L2_DEV_H */