diff options
author | Jonathan Herman <hermanjl@cs.unc.edu> | 2013-01-22 10:38:37 -0500 |
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committer | Jonathan Herman <hermanjl@cs.unc.edu> | 2013-01-22 10:38:37 -0500 |
commit | fcc9d2e5a6c89d22b8b773a64fb4ad21ac318446 (patch) | |
tree | a57612d1888735a2ec7972891b68c1ac5ec8faea /drivers/media/video/v4l2-fh.c | |
parent | 8dea78da5cee153b8af9c07a2745f6c55057fe12 (diff) |
Diffstat (limited to 'drivers/media/video/v4l2-fh.c')
-rw-r--r-- | drivers/media/video/v4l2-fh.c | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/drivers/media/video/v4l2-fh.c b/drivers/media/video/v4l2-fh.c new file mode 100644 index 00000000000..122822d2b8b --- /dev/null +++ b/drivers/media/video/v4l2-fh.c | |||
@@ -0,0 +1,119 @@ | |||
1 | /* | ||
2 | * v4l2-fh.c | ||
3 | * | ||
4 | * V4L2 file handles. | ||
5 | * | ||
6 | * Copyright (C) 2009--2010 Nokia Corporation. | ||
7 | * | ||
8 | * Contact: Sakari Ailus <sakari.ailus@maxwell.research.nokia.com> | ||
9 | * | ||
10 | * This program is free software; you can redistribute it and/or | ||
11 | * modify it under the terms of the GNU General Public License | ||
12 | * version 2 as published by the Free Software Foundation. | ||
13 | * | ||
14 | * This program is distributed in the hope that it will be useful, but | ||
15 | * WITHOUT ANY WARRANTY; without even the implied warranty of | ||
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
17 | * General Public License for more details. | ||
18 | * | ||
19 | * You should have received a copy of the GNU General Public License | ||
20 | * along with this program; if not, write to the Free Software | ||
21 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA | ||
22 | * 02110-1301 USA | ||
23 | */ | ||
24 | |||
25 | #include <linux/bitops.h> | ||
26 | #include <linux/slab.h> | ||
27 | #include <media/v4l2-dev.h> | ||
28 | #include <media/v4l2-fh.h> | ||
29 | #include <media/v4l2-event.h> | ||
30 | #include <media/v4l2-ioctl.h> | ||
31 | |||
32 | void v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev) | ||
33 | { | ||
34 | fh->vdev = vdev; | ||
35 | /* Inherit from video_device. May be overridden by the driver. */ | ||
36 | fh->ctrl_handler = vdev->ctrl_handler; | ||
37 | INIT_LIST_HEAD(&fh->list); | ||
38 | set_bit(V4L2_FL_USES_V4L2_FH, &fh->vdev->flags); | ||
39 | fh->prio = V4L2_PRIORITY_UNSET; | ||
40 | init_waitqueue_head(&fh->wait); | ||
41 | INIT_LIST_HEAD(&fh->available); | ||
42 | INIT_LIST_HEAD(&fh->subscribed); | ||
43 | fh->sequence = -1; | ||
44 | } | ||
45 | EXPORT_SYMBOL_GPL(v4l2_fh_init); | ||
46 | |||
47 | void v4l2_fh_add(struct v4l2_fh *fh) | ||
48 | { | ||
49 | unsigned long flags; | ||
50 | |||
51 | if (test_bit(V4L2_FL_USE_FH_PRIO, &fh->vdev->flags)) | ||
52 | v4l2_prio_open(fh->vdev->prio, &fh->prio); | ||
53 | spin_lock_irqsave(&fh->vdev->fh_lock, flags); | ||
54 | list_add(&fh->list, &fh->vdev->fh_list); | ||
55 | spin_unlock_irqrestore(&fh->vdev->fh_lock, flags); | ||
56 | } | ||
57 | EXPORT_SYMBOL_GPL(v4l2_fh_add); | ||
58 | |||
59 | int v4l2_fh_open(struct file *filp) | ||
60 | { | ||
61 | struct video_device *vdev = video_devdata(filp); | ||
62 | struct v4l2_fh *fh = kzalloc(sizeof(*fh), GFP_KERNEL); | ||
63 | |||
64 | filp->private_data = fh; | ||
65 | if (fh == NULL) | ||
66 | return -ENOMEM; | ||
67 | v4l2_fh_init(fh, vdev); | ||
68 | v4l2_fh_add(fh); | ||
69 | return 0; | ||
70 | } | ||
71 | EXPORT_SYMBOL_GPL(v4l2_fh_open); | ||
72 | |||
73 | void v4l2_fh_del(struct v4l2_fh *fh) | ||
74 | { | ||
75 | unsigned long flags; | ||
76 | |||
77 | spin_lock_irqsave(&fh->vdev->fh_lock, flags); | ||
78 | list_del_init(&fh->list); | ||
79 | spin_unlock_irqrestore(&fh->vdev->fh_lock, flags); | ||
80 | if (test_bit(V4L2_FL_USE_FH_PRIO, &fh->vdev->flags)) | ||
81 | v4l2_prio_close(fh->vdev->prio, fh->prio); | ||
82 | } | ||
83 | EXPORT_SYMBOL_GPL(v4l2_fh_del); | ||
84 | |||
85 | void v4l2_fh_exit(struct v4l2_fh *fh) | ||
86 | { | ||
87 | if (fh->vdev == NULL) | ||
88 | return; | ||
89 | v4l2_event_unsubscribe_all(fh); | ||
90 | fh->vdev = NULL; | ||
91 | } | ||
92 | EXPORT_SYMBOL_GPL(v4l2_fh_exit); | ||
93 | |||
94 | int v4l2_fh_release(struct file *filp) | ||
95 | { | ||
96 | struct v4l2_fh *fh = filp->private_data; | ||
97 | |||
98 | if (fh) { | ||
99 | v4l2_fh_del(fh); | ||
100 | v4l2_fh_exit(fh); | ||
101 | kfree(fh); | ||
102 | } | ||
103 | return 0; | ||
104 | } | ||
105 | EXPORT_SYMBOL_GPL(v4l2_fh_release); | ||
106 | |||
107 | int v4l2_fh_is_singular(struct v4l2_fh *fh) | ||
108 | { | ||
109 | unsigned long flags; | ||
110 | int is_singular; | ||
111 | |||
112 | if (fh == NULL || fh->vdev == NULL) | ||
113 | return 0; | ||
114 | spin_lock_irqsave(&fh->vdev->fh_lock, flags); | ||
115 | is_singular = list_is_singular(&fh->list); | ||
116 | spin_unlock_irqrestore(&fh->vdev->fh_lock, flags); | ||
117 | return is_singular; | ||
118 | } | ||
119 | EXPORT_SYMBOL_GPL(v4l2_fh_is_singular); | ||