tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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#define VIDEO_MAJOR 81
20
21#define VFL_TYPE_GRABBER 0
22#define VFL_TYPE_VBI 1
23#define VFL_TYPE_RADIO 2
24#define VFL_TYPE_VTX 3
25#define VFL_TYPE_MAX 4
26
27struct v4l2_ioctl_callbacks;
28
29/*
30 * Newer version of video_device, handled by videodev2.c
31 * This version moves redundant code from video device code to
32 * the common handler
33 */
34
35struct video_device
36{
37 /* device ops */
38 const struct file_operations *fops;
39
40 /* sysfs */
41 struct device dev; /* v4l device */
42 struct cdev cdev; /* character device */
43 void (*cdev_release)(struct kobject *kobj);
44 struct device *parent; /* device parent */
45
46 /* device info */
47 char name[32];
48 int vfl_type;
49 int minor;
50 u16 num;
51 /* attribute to differentiate multiple indices on one physical device */
52 int index;
53
54 int debug; /* Activates debug level*/
55
56 /* Video standard vars */
57 v4l2_std_id tvnorms; /* Supported tv norms */
58 v4l2_std_id current_norm; /* Current tvnorm */
59
60 /* callbacks */
61 void (*release)(struct video_device *vfd);
62
63 /* ioctl callbacks */
64 const struct v4l2_ioctl_ops *ioctl_ops;
65};
66
67/* dev to video-device */
68#define to_video_device(cd) container_of(cd, struct video_device, dev)
69
70/* Register and unregister devices. Note that if video_register_device fails,
71 the release() callback of the video_device structure is *not* called, so
72 the caller is responsible for freeing any data. Usually that means that
73 you call video_device_release() on failure. */
74int __must_check video_register_device(struct video_device *vfd, int type, int nr);
75int __must_check video_register_device_index(struct video_device *vfd,
76 int type, int nr, int index);
77void video_unregister_device(struct video_device *vfd);
78
79/* helper functions to alloc/release struct video_device, the
80 latter can also be used for video_device->release(). */
81struct video_device * __must_check video_device_alloc(void);
82
83/* this release function frees the vfd pointer */
84void video_device_release(struct video_device *vfd);
85
86/* this release function does nothing, use when the video_device is a
87 static global struct. Note that having a static video_device is
88 a dubious construction at best. */
89void video_device_release_empty(struct video_device *vfd);
90
91/* helper functions to access driver private data. */
92static inline void *video_get_drvdata(struct video_device *dev)
93{
94 return dev_get_drvdata(&dev->dev);
95}
96
97static inline void video_set_drvdata(struct video_device *dev, void *data)
98{
99 dev_set_drvdata(&dev->dev, data);
100}
101
102struct video_device *video_devdata(struct file *file);
103
104/* Combine video_get_drvdata and video_devdata as this is
105 used very often. */
106static inline void *video_drvdata(struct file *file)
107{
108 return video_get_drvdata(video_devdata(file));
109}
110
111#endif /* _V4L2_DEV_H */