summaryrefslogtreecommitdiffstats
path: root/include/media/v4l2-dev.h
blob: 93e96fb934526e44b327e8d677bb91f7accd80c4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
/*
 *
 *	V 4 L 2   D R I V E R   H E L P E R   A P I
 *
 * Moved from videodev2.h
 *
 *	Some commonly needed functions for drivers (v4l2-common.o module)
 */
#ifndef _V4L2_DEV_H
#define _V4L2_DEV_H

#include <linux/poll.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/cdev.h>
#include <linux/mutex.h>
#include <linux/videodev2.h>

#include <media/media-entity.h>

#define VIDEO_MAJOR	81

#define VFL_TYPE_GRABBER	0
#define VFL_TYPE_VBI		1
#define VFL_TYPE_RADIO		2
#define VFL_TYPE_SUBDEV		3
#define VFL_TYPE_MAX		4

struct v4l2_ioctl_callbacks;
struct video_device;
struct v4l2_device;
struct v4l2_ctrl_handler;

/* Flag to mark the video_device struct as registered.
   Drivers can clear this flag if they want to block all future
   device access. It is cleared by video_unregister_device. */
#define V4L2_FL_REGISTERED	(0)
/* file->private_data points to struct v4l2_fh */
#define V4L2_FL_USES_V4L2_FH	(1)
/* Use the prio field of v4l2_fh for core priority checking */
#define V4L2_FL_USE_FH_PRIO	(2)

/* Priority helper functions */

struct v4l2_prio_state {
	atomic_t prios[4];
};

void v4l2_prio_init(struct v4l2_prio_state *global);
int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
		     enum v4l2_priority new);
void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local);
void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local);
enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global);
int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local);


struct v4l2_file_operations {
	struct module *owner;
	ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
	ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
	unsigned int (*poll) (struct file *, struct poll_table_struct *);
	long (*ioctl) (struct file *, unsigned int, unsigned long);
	long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
	unsigned long (*get_unmapped_area) (struct file *, unsigned long,
				unsigned long, unsigned long, unsigned long);
	int (*mmap) (struct file *, struct vm_area_struct *);
	int (*open) (struct file *);
	int (*release) (struct file *);
};

/*
 * Newer version of video_device, handled by videodev2.c
 * 	This version moves redundant code from video device code to
 *	the common handler
 */

struct video_device
{
#if defined(CONFIG_MEDIA_CONTROLLER)
	struct media_entity entity;
#endif
	/* device ops */
	const struct v4l2_file_operations *fops;

	/* sysfs */
	struct device dev;		/* v4l device */
	struct cdev *cdev;		/* character device */

	/* Set either parent or v4l2_dev if your driver uses v4l2_device */
	struct device *parent;		/* device parent */
	struct v4l2_device *v4l2_dev;	/* v4l2_device parent */

	/* Control handler associated with this device node. May be NULL. */
	struct v4l2_ctrl_handler *ctrl_handler;

	/* Priority state. If NULL, then v4l2_dev->prio will be used. */
	struct v4l2_prio_state *prio;

	/* device info */
	char name[32];
	int vfl_type;
	/* 'minor' is set to -1 if the registration failed */
	int minor;
	u16 num;
	/* use bitops to set/clear/test flags */
	unsigned long flags;
	/* attribute to differentiate multiple indices on one physical device */
	int index;

	/* V4L2 file handles */
	spinlock_t		fh_lock; /* Lock for all v4l2_fhs */
	struct list_head	fh_list; /* List of struct v4l2_fh */

	int debug;			/* Activates debug level*/

	/* Video standard vars */
	v4l2_std_id tvnorms;		/* Supported tv norms */
	v4l2_std_id current_norm;	/* Current tvnorm */

	/* callbacks */
	void (*release)(struct video_device *vdev);

	/* ioctl callbacks */
	const struct v4l2_ioctl_ops *ioctl_ops;

	/* serialization lock */
	struct mutex *lock;
};

#define media_entity_to_video_device(entity) \
	container_of(entity, struct video_device, entity)
/* dev to video-device */
#define to_video_device(cd) container_of(cd, struct video_device, dev)

int __must_check __video_register_device(struct video_device *vdev, int type,
		int nr, int warn_if_nr_in_use, struct module *owner);

/* Register video devices. Note that if video_register_device fails,
   the release() callback of the video_device structure is *not* called, so
   the caller is responsible for freeing any data. Usually that means that
   you call video_device_release() on failure. */
static inline int __must_check video_register_device(struct video_device *vdev,
		int type, int nr)
{
	return __video_register_device(vdev, type, nr, 1, vdev->fops->owner);
}

/* Same as video_register_device, but no warning is issued if the desired
   device node number was already in use. */
static inline int __must_check video_register_device_no_warn(
		struct video_device *vdev, int type, int nr)
{
	return __video_register_device(vdev, type, nr, 0, vdev->fops->owner);
}

/* Unregister video devices. Will do nothing if vdev == NULL or
   video_is_registered() returns false. */
void video_unregister_device(struct video_device *vdev);

/* helper functions to alloc/release struct video_device, the
   latter can also be used for video_device->release(). */
struct video_device * __must_check video_device_alloc(void);

/* this release function frees the vdev pointer */
void video_device_release(struct video_device *vdev);

/* this release function does nothing, use when the video_device is a
   static global struct. Note that having a static video_device is
   a dubious construction at best. */
void video_device_release_empty(struct video_device *vdev);

/* helper functions to access driver private data. */
static inline void *video_get_drvdata(struct video_device *vdev)
{
	return dev_get_drvdata(&vdev->dev);
}

static inline void video_set_drvdata(struct video_device *vdev, void *data)
{
	dev_set_drvdata(&vdev->dev, data);
}

struct video_device *video_devdata(struct file *file);

/* Combine video_get_drvdata and video_devdata as this is
   used very often. */
static inline void *video_drvdata(struct file *file)
{
	return video_get_drvdata(video_devdata(file));
}

static inline const char *video_device_node_name(struct video_device *vdev)
{
	return dev_name(&vdev->dev);
}

static inline int video_is_registered(struct video_device *vdev)
{
	return test_bit(V4L2_FL_REGISTERED, &vdev->flags);
}

#endif /* _V4L2_DEV_H */
OpenPOWER on IntegriCloud