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
|
/*
* v4l2-fh.h
*
* V4L2 file handle. Store per file handle data for the V4L2
* framework. Using file handles is optional for the drivers.
*
* Copyright (C) 2009--2010 Nokia Corporation.
*
* Contact: Sakari Ailus <sakari.ailus@iki.fi>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*/
#ifndef V4L2_FH_H
#define V4L2_FH_H
#include <linux/fs.h>
#include <linux/list.h>
#include <linux/videodev2.h>
struct video_device;
struct v4l2_ctrl_handler;
/**
* struct v4l2_fh - Describes a V4L2 file handler
*
* @list: list of file handlers
* @vdev: pointer to &struct video_device
* @ctrl_handler: pointer to &struct v4l2_ctrl_handler
* @prio: priority of the file handler, as defined by &enum v4l2_priority
*
* @wait: event' s wait queue
* @subscribed: list of subscribed events
* @available: list of events waiting to be dequeued
* @navailable: number of available events at @available list
* @sequence: event sequence number
* @m2m_ctx: pointer to &struct v4l2_m2m_ctx
*/
struct v4l2_fh {
struct list_head list;
struct video_device *vdev;
struct v4l2_ctrl_handler *ctrl_handler;
enum v4l2_priority prio;
/* Events */
wait_queue_head_t wait;
struct list_head subscribed;
struct list_head available;
unsigned int navailable;
u32 sequence;
#if IS_ENABLED(CONFIG_V4L2_MEM2MEM_DEV)
struct v4l2_m2m_ctx *m2m_ctx;
#endif
};
/**
* v4l2_fh_init - Initialise the file handle.
*
* @fh: pointer to &struct v4l2_fh
* @vdev: pointer to &struct video_device
*
* Parts of the V4L2 framework using the
* file handles should be initialised in this function. Must be called
* from driver's v4l2_file_operations->open\(\) handler if the driver
* uses &struct v4l2_fh.
*/
void v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev);
/**
* v4l2_fh_add - Add the fh to the list of file handles on a video_device.
*
* @fh: pointer to &struct v4l2_fh
*
* .. note::
* The @fh file handle must be initialised first.
*/
void v4l2_fh_add(struct v4l2_fh *fh);
/**
* v4l2_fh_open - Ancillary routine that can be used as the open\(\) op
* of v4l2_file_operations.
*
* @filp: pointer to struct file
*
* It allocates a v4l2_fh and inits and adds it to the &struct video_device
* associated with the file pointer.
*/
int v4l2_fh_open(struct file *filp);
/**
* v4l2_fh_del - Remove file handle from the list of file handles.
*
* @fh: pointer to &struct v4l2_fh
*
* On error filp->private_data will be %NULL, otherwise it will point to
* the &struct v4l2_fh.
*
* .. note::
* Must be called in v4l2_file_operations->release\(\) handler if the driver
* uses &struct v4l2_fh.
*/
void v4l2_fh_del(struct v4l2_fh *fh);
/**
* v4l2_fh_exit - Release resources related to a file handle.
*
* @fh: pointer to &struct v4l2_fh
*
* Parts of the V4L2 framework using the v4l2_fh must release their
* resources here, too.
*
* .. note::
* Must be called in v4l2_file_operations->release\(\) handler if the
* driver uses &struct v4l2_fh.
*/
void v4l2_fh_exit(struct v4l2_fh *fh);
/**
* v4l2_fh_release - Ancillary routine that can be used as the release\(\) op
* of v4l2_file_operations.
*
* @filp: pointer to struct file
*
* It deletes and exits the v4l2_fh associated with the file pointer and
* frees it. It will do nothing if filp->private_data (the pointer to the
* v4l2_fh struct) is %NULL.
*
* This function always returns 0.
*/
int v4l2_fh_release(struct file *filp);
/**
* v4l2_fh_is_singular - Returns 1 if this filehandle is the only filehandle
* opened for the associated video_device.
*
* @fh: pointer to &struct v4l2_fh
*
* If @fh is NULL, then it returns 0.
*/
int v4l2_fh_is_singular(struct v4l2_fh *fh);
/**
* v4l2_fh_is_singular_file - Returns 1 if this filehandle is the only
* filehandle opened for the associated video_device.
*
* @filp: pointer to struct file
*
* This is a helper function variant of v4l2_fh_is_singular() with uses
* struct file as argument.
*
* If filp->private_data is %NULL, then it will return 0.
*/
static inline int v4l2_fh_is_singular_file(struct file *filp)
{
return v4l2_fh_is_singular(filp->private_data);
}
#endif /* V4L2_EVENT_H */
|
