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