tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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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#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
29struct v4l2_ioctl_callbacks;
30struct video_device;
31struct v4l2_device;
32struct 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
43/* Priority helper functions */
44
45struct v4l2_prio_state {
46 atomic_t prios[4];
47};
48
49void v4l2_prio_init(struct v4l2_prio_state *global);
50int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
51 enum v4l2_priority new);
52void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local);
53void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local);
54enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global);
55int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local);
56
57
58struct v4l2_file_operations {
59 struct module *owner;
60 ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
61 ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
62 unsigned int (*poll) (struct file *, struct poll_table_struct *);
63 long (*ioctl) (struct file *, unsigned int, unsigned long);
64 long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
65 unsigned long (*get_unmapped_area) (struct file *, unsigned long,
66 unsigned long, unsigned long, unsigned long);
67 int (*mmap) (struct file *, struct vm_area_struct *);
68 int (*open) (struct file *);
69 int (*release) (struct file *);
70};
71
72/*
73 * Newer version of video_device, handled by videodev2.c
74 * This version moves redundant code from video device code to
75 * the common handler
76 */
77
78struct video_device
79{
80#if defined(CONFIG_MEDIA_CONTROLLER)
81 struct media_entity entity;
82#endif
83 /* device ops */
84 const struct v4l2_file_operations *fops;
85
86 /* sysfs */
87 struct device dev; /* v4l device */
88 struct cdev *cdev; /* character device */
89
90 /* Set either parent or v4l2_dev if your driver uses v4l2_device */
91 struct device *parent; /* device parent */
92 struct v4l2_device *v4l2_dev; /* v4l2_device parent */
93
94 /* Control handler associated with this device node. May be NULL. */
95 struct v4l2_ctrl_handler *ctrl_handler;
96
97 /* Priority state. If NULL, then v4l2_dev->prio will be used. */
98 struct v4l2_prio_state *prio;
99
100 /* device info */
101 char name[32];
102 int vfl_type;
103 /* 'minor' is set to -1 if the registration failed */
104 int minor;
105 u16 num;
106 /* use bitops to set/clear/test flags */
107 unsigned long flags;
108 /* attribute to differentiate multiple indices on one physical device */
109 int index;
110
111 /* V4L2 file handles */
112 spinlock_t fh_lock; /* Lock for all v4l2_fhs */
113 struct list_head fh_list; /* List of struct v4l2_fh */
114
115 int debug; /* Activates debug level*/
116
117 /* Video standard vars */
118 v4l2_std_id tvnorms; /* Supported tv norms */
119 v4l2_std_id current_norm; /* Current tvnorm */
120
121 /* callbacks */
122 void (*release)(struct video_device *vdev);
123
124 /* ioctl callbacks */
125 const struct v4l2_ioctl_ops *ioctl_ops;
126
127 /* serialization lock */
128 struct mutex *lock;
129};
130
131#define media_entity_to_video_device(__e) \
132 container_of(__e, struct video_device, entity)
133/* dev to video-device */
134#define to_video_device(cd) container_of(cd, struct video_device, dev)
135
136int __must_check __video_register_device(struct video_device *vdev, int type,
137 int nr, int warn_if_nr_in_use, struct module *owner);
138
139/* Register video devices. Note that if video_register_device fails,
140 the release() callback of the video_device structure is *not* called, so
141 the caller is responsible for freeing any data. Usually that means that
142 you call video_device_release() on failure. */
143static inline int __must_check video_register_device(struct video_device *vdev,
144 int type, int nr)
145{
146 return __video_register_device(vdev, type, nr, 1, vdev->fops->owner);
147}
148
149/* Same as video_register_device, but no warning is issued if the desired
150 device node number was already in use. */
151static inline int __must_check video_register_device_no_warn(
152 struct video_device *vdev, int type, int nr)
153{
154 return __video_register_device(vdev, type, nr, 0, vdev->fops->owner);
155}
156
157/* Unregister video devices. Will do nothing if vdev == NULL or
158 video_is_registered() returns false. */
159void video_unregister_device(struct video_device *vdev);
160
161/* helper functions to alloc/release struct video_device, the
162 latter can also be used for video_device->release(). */
163struct video_device * __must_check video_device_alloc(void);
164
165/* this release function frees the vdev pointer */
166void video_device_release(struct video_device *vdev);
167
168/* this release function does nothing, use when the video_device is a
169 static global struct. Note that having a static video_device is
170 a dubious construction at best. */
171void video_device_release_empty(struct video_device *vdev);
172
173/* helper functions to access driver private data. */
174static inline void *video_get_drvdata(struct video_device *vdev)
175{
176 return dev_get_drvdata(&vdev->dev);
177}
178
179static inline void video_set_drvdata(struct video_device *vdev, void *data)
180{
181 dev_set_drvdata(&vdev->dev, data);
182}
183
184struct video_device *video_devdata(struct file *file);
185
186/* Combine video_get_drvdata and video_devdata as this is
187 used very often. */
188static inline void *video_drvdata(struct file *file)
189{
190 return video_get_drvdata(video_devdata(file));
191}
192
193static inline const char *video_device_node_name(struct video_device *vdev)
194{
195 return dev_name(&vdev->dev);
196}
197
198static inline int video_is_registered(struct video_device *vdev)
199{
200 return test_bit(V4L2_FL_REGISTERED, &vdev->flags);
201}
202
203#endif /* _V4L2_DEV_H */