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1babcb46 SA |
1 | /* |
2 | * v4l2-fh.h | |
3 | * | |
4 | * V4L2 file handle. Store per file handle data for the V4L2 | |
5 | * framework. Using file handles is optional for the drivers. | |
6 | * | |
7 | * Copyright (C) 2009--2010 Nokia Corporation. | |
8 | * | |
9 | * Contact: Sakari Ailus <sakari.ailus@maxwell.research.nokia.com> | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or | |
12 | * modify it under the terms of the GNU General Public License | |
13 | * version 2 as published by the Free Software Foundation. | |
14 | * | |
15 | * This program is distributed in the hope that it will be useful, but | |
16 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
18 | * General Public License for more details. | |
19 | * | |
20 | * You should have received a copy of the GNU General Public License | |
21 | * along with this program; if not, write to the Free Software | |
22 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA | |
23 | * 02110-1301 USA | |
24 | */ | |
25 | ||
26 | #ifndef V4L2_FH_H | |
27 | #define V4L2_FH_H | |
28 | ||
29 | #include <linux/list.h> | |
30 | ||
31 | struct video_device; | |
c3b5b024 | 32 | struct v4l2_events; |
1babcb46 SA |
33 | |
34 | struct v4l2_fh { | |
35 | struct list_head list; | |
36 | struct video_device *vdev; | |
c3b5b024 | 37 | struct v4l2_events *events; /* events, pending and subscribed */ |
fc5602be | 38 | enum v4l2_priority prio; |
1babcb46 SA |
39 | }; |
40 | ||
41 | /* | |
42 | * Initialise the file handle. Parts of the V4L2 framework using the | |
43 | * file handles should be initialised in this function. Must be called | |
44 | * from driver's v4l2_file_operations->open() handler if the driver | |
45 | * uses v4l2_fh. | |
46 | */ | |
47 | int v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev); | |
48 | /* | |
49 | * Add the fh to the list of file handles on a video_device. The file | |
50 | * handle must be initialised first. | |
51 | */ | |
52 | void v4l2_fh_add(struct v4l2_fh *fh); | |
73cb4206 HV |
53 | /* |
54 | * Can be used as the open() op of v4l2_file_operations. | |
55 | * It allocates a v4l2_fh and inits and adds it to the video_device associated | |
56 | * with the file pointer. | |
57 | */ | |
58 | int v4l2_fh_open(struct file *filp); | |
1babcb46 SA |
59 | /* |
60 | * Remove file handle from the list of file handles. Must be called in | |
61 | * v4l2_file_operations->release() handler if the driver uses v4l2_fh. | |
73cb4206 HV |
62 | * On error filp->private_data will be NULL, otherwise it will point to |
63 | * the v4l2_fh struct. | |
1babcb46 SA |
64 | */ |
65 | void v4l2_fh_del(struct v4l2_fh *fh); | |
66 | /* | |
67 | * Release resources related to a file handle. Parts of the V4L2 | |
68 | * framework using the v4l2_fh must release their resources here, too. | |
69 | * Must be called in v4l2_file_operations->release() handler if the | |
70 | * driver uses v4l2_fh. | |
71 | */ | |
72 | void v4l2_fh_exit(struct v4l2_fh *fh); | |
73cb4206 HV |
73 | /* |
74 | * Can be used as the release() op of v4l2_file_operations. | |
75 | * It deletes and exits the v4l2_fh associated with the file pointer and | |
76 | * frees it. It will do nothing if filp->private_data (the pointer to the | |
77 | * v4l2_fh struct) is NULL. This function always returns 0. | |
78 | */ | |
79 | int v4l2_fh_release(struct file *filp); | |
dfddb244 HV |
80 | /* |
81 | * Returns 1 if this filehandle is the only filehandle opened for the | |
82 | * associated video_device. If fh is NULL, then it returns 0. | |
83 | */ | |
84 | int v4l2_fh_is_singular(struct v4l2_fh *fh); | |
85 | /* | |
86 | * Helper function with struct file as argument. If filp->private_data is | |
87 | * NULL, then it will return 0. | |
88 | */ | |
89 | static inline int v4l2_fh_is_singular_file(struct file *filp) | |
90 | { | |
91 | return v4l2_fh_is_singular(filp->private_data); | |
92 | } | |
1babcb46 SA |
93 | |
94 | #endif /* V4L2_EVENT_H */ |