3 * V 4 L 2 D R I V E R H E L P E R A P I
5 * Moved from videodev2.h
7 * Some commonly needed functions for drivers (v4l2-common.o module)
12 #include <linux/poll.h>
14 #include <linux/device.h>
15 #include <linux/cdev.h>
16 #include <linux/mutex.h>
17 #include <linux/videodev2.h>
19 #include <media/media-entity.h>
21 #define VIDEO_MAJOR 81
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
30 /* Is this a receiver, transmitter or mem-to-mem? */
31 /* Ignored for VFL_TYPE_SUBDEV. */
36 struct v4l2_ioctl_callbacks;
39 struct v4l2_ctrl_handler;
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)
48 /* Priority helper functions */
50 struct v4l2_prio_state {
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);
63 struct v4l2_file_operations {
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);
70 long (*compat_ioctl32) (struct file *, unsigned int, unsigned long);
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 *);
80 * Newer version of video_device, handled by videodev2.c
81 * This version moves redundant code from video device code to
87 #if defined(CONFIG_MEDIA_CONTROLLER)
88 struct media_entity entity;
91 const struct v4l2_file_operations *fops;
94 struct device dev; /* v4l device */
95 struct cdev *cdev; /* character device */
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 */
101 /* Control handler associated with this device node. May be NULL. */
102 struct v4l2_ctrl_handler *ctrl_handler;
104 /* vb2_queue associated with this device node. May be NULL. */
105 struct vb2_queue *queue;
107 /* Priority state. If NULL, then v4l2_dev->prio will be used. */
108 struct v4l2_prio_state *prio;
112 int vfl_type; /* device type */
113 int vfl_dir; /* receiver, transmitter or m2m */
114 /* 'minor' is set to -1 if the registration failed */
117 /* use bitops to set/clear/test flags */
119 /* attribute to differentiate multiple indices on one physical device */
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 */
126 /* Internal device debug flags, not for use by drivers */
129 /* Video standard vars */
130 v4l2_std_id tvnorms; /* Supported tv norms */
133 void (*release)(struct video_device *vdev);
135 /* ioctl callbacks */
136 const struct v4l2_ioctl_ops *ioctl_ops;
137 DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE);
139 /* serialization lock */
140 DECLARE_BITMAP(disable_locking, BASE_VIDIOC_PRIVATE);
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)
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);
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,
159 return __video_register_device(vdev, type, nr, 1, vdev->fops->owner);
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)
167 return __video_register_device(vdev, type, nr, 0, vdev->fops->owner);
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);
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);
178 /* this release function frees the vdev pointer */
179 void video_device_release(struct video_device *vdev);
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);
186 /* returns true if cmd is a known V4L2 ioctl */
187 bool v4l2_is_known_ioctl(unsigned int cmd);
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)
192 if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE)
193 set_bit(_IOC_NR(cmd), vdev->disable_locking);
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)
202 if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE)
203 set_bit(_IOC_NR(cmd), vdev->valid_ioctls);
206 /* helper functions to access driver private data. */
207 static inline void *video_get_drvdata(struct video_device *vdev)
209 return dev_get_drvdata(&vdev->dev);
212 static inline void video_set_drvdata(struct video_device *vdev, void *data)
214 dev_set_drvdata(&vdev->dev, data);
217 struct video_device *video_devdata(struct file *file);
219 /* Combine video_get_drvdata and video_devdata as this is
221 static inline void *video_drvdata(struct file *file)
223 return video_get_drvdata(video_devdata(file));
226 static inline const char *video_device_node_name(struct video_device *vdev)
228 return dev_name(&vdev->dev);
231 static inline int video_is_registered(struct video_device *vdev)
233 return test_bit(V4L2_FL_REGISTERED, &vdev->flags);
236 #endif /* _V4L2_DEV_H */