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         /* Priority state. If NULL, then v4l2_dev->prio will be used. */
 104         struct v4l2_prio_state *prio;
 105
 106         /* device info */
 107         char name[32];
 108         int vfl_type;
 109         /* 'minor' is set to -1 if the registration failed */
 110         int minor;
 111         u16 num;
 112         /* use bitops to set/clear/test flags */
 113         unsigned long flags;
 114         /* attribute to differentiate multiple indices on one physical device */
 115         int index;
 116
 117         /* V4L2 file handles */
 118         spinlock_t              fh_lock; /* Lock for all v4l2_fhs */
 119         struct list_head        fh_list; /* List of struct v4l2_fh */
 120
 121         int debug;                      /* Activates debug level*/
 122
 123         /* Video standard vars */
 124         v4l2_std_id tvnorms;            /* Supported tv norms */
 125         v4l2_std_id current_norm;       /* Current tvnorm */
 126
 127         /* callbacks */
 128         void (*release)(struct video_device *vdev);
 129
 130         /* ioctl callbacks */
 131         const struct v4l2_ioctl_ops *ioctl_ops;
 132         DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE);
 133
 134         /* serialization lock */
 135         DECLARE_BITMAP(disable_locking, BASE_VIDIOC_PRIVATE);
 136         struct mutex *lock;
 137 };
 138
 139 #define media_entity_to_video_device(__e) \
 140         container_of(__e, struct video_device, entity)
 141 /* dev to video-device */
 142 #define to_video_device(cd) container_of(cd, struct video_device, dev)
 143
 144 int __must_check __video_register_device(struct video_device *vdev, int type,
 145                 int nr, int warn_if_nr_in_use, struct module *owner);
 146
 147 /* Register video devices. Note that if video_register_device fails,
 148    the release() callback of the video_device structure is *not* called, so
 149    the caller is responsible for freeing any data. Usually that means that
 150    you call video_device_release() on failure. */
 151 static inline int __must_check video_register_device(struct video_device *vdev,
 152                 int type, int nr)
 153 {
 154         return __video_register_device(vdev, type, nr, 1, vdev->fops->owner);
 155 }
 156
 157 /* Same as video_register_device, but no warning is issued if the desired
 158    device node number was already in use. */
 159 static inline int __must_check video_register_device_no_warn(
 160                 struct video_device *vdev, int type, int nr)
 161 {
 162         return __video_register_device(vdev, type, nr, 0, vdev->fops->owner);
 163 }
 164
 165 /* Unregister video devices. Will do nothing if vdev == NULL or
 166    video_is_registered() returns false. */
 167 void video_unregister_device(struct video_device *vdev);
 168
 169 /* helper functions to alloc/release struct video_device, the
 170    latter can also be used for video_device->release(). */
 171 struct video_device * __must_check video_device_alloc(void);
 172
 173 /* this release function frees the vdev pointer */
 174 void video_device_release(struct video_device *vdev);
 175
 176 /* this release function does nothing, use when the video_device is a
 177    static global struct. Note that having a static video_device is
 178    a dubious construction at best. */
 179 void video_device_release_empty(struct video_device *vdev);
 180
 181 /* returns true if cmd is a known V4L2 ioctl */
 182 bool v4l2_is_known_ioctl(unsigned int cmd);
 183
 184 /* mark that this command shouldn't use core locking */
 185 static inline void v4l2_disable_ioctl_locking(struct video_device *vdev, unsigned int cmd)
 186 {
 187         if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE)
 188                 set_bit(_IOC_NR(cmd), vdev->disable_locking);
 189 }
 190
 191 /* Mark that this command isn't implemented. This must be called before
 192    video_device_register. See also the comments in determine_valid_ioctls().
 193    This function allows drivers to provide just one v4l2_ioctl_ops struct, but
 194    disable ioctls based on the specific card that is actually found. */
 195 static inline void v4l2_disable_ioctl(struct video_device *vdev, unsigned int cmd)
 196 {
 197         if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE)
 198                 set_bit(_IOC_NR(cmd), vdev->valid_ioctls);
 199 }
 200
 201 /* helper functions to access driver private data. */
 202 static inline void *video_get_drvdata(struct video_device *vdev)
 203 {
 204         return dev_get_drvdata(&vdev->dev);
 205 }
 206
 207 static inline void video_set_drvdata(struct video_device *vdev, void *data)
 208 {
 209         dev_set_drvdata(&vdev->dev, data);
 210 }
 211
 212 struct video_device *video_devdata(struct file *file);
 213
 214 /* Combine video_get_drvdata and video_devdata as this is
 215    used very often. */
 216 static inline void *video_drvdata(struct file *file)
 217 {
 218         return video_get_drvdata(video_devdata(file));
 219 }
 220
 221 static inline const char *video_device_node_name(struct video_device *vdev)
 222 {
 223         return dev_name(&vdev->dev);
 224 }
 225
 226 static inline int video_is_registered(struct video_device *vdev)
 227 {
 228         return test_bit(V4L2_FL_REGISTERED, &vdev->flags);
 229 }
 230
 231 #endif /* _V4L2_DEV_H */