4 * V4L2 file handle. Store per file handle data for the V4L2
5 * framework. Using file handles is optional for the drivers.
7 * Copyright (C) 2009--2010 Nokia Corporation.
9 * Contact: Sakari Ailus <sakari.ailus@iki.fi>
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.
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.
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
30 #include <linux/list.h>
31 #include <linux/videodev2.h>
34 struct v4l2_ctrl_handler
;
37 struct list_head list
;
38 struct video_device
*vdev
;
39 struct v4l2_ctrl_handler
*ctrl_handler
;
40 enum v4l2_priority prio
;
43 wait_queue_head_t wait
;
44 struct list_head subscribed
; /* Subscribed events */
45 struct list_head available
; /* Dequeueable event */
46 unsigned int navailable
;
51 * Initialise the file handle. Parts of the V4L2 framework using the
52 * file handles should be initialised in this function. Must be called
53 * from driver's v4l2_file_operations->open() handler if the driver
56 void v4l2_fh_init(struct v4l2_fh
*fh
, struct video_device
*vdev
);
58 * Add the fh to the list of file handles on a video_device. The file
59 * handle must be initialised first.
61 void v4l2_fh_add(struct v4l2_fh
*fh
);
63 * Can be used as the open() op of v4l2_file_operations.
64 * It allocates a v4l2_fh and inits and adds it to the video_device associated
65 * with the file pointer.
67 int v4l2_fh_open(struct file
*filp
);
69 * Remove file handle from the list of file handles. Must be called in
70 * v4l2_file_operations->release() handler if the driver uses v4l2_fh.
71 * On error filp->private_data will be NULL, otherwise it will point to
74 void v4l2_fh_del(struct v4l2_fh
*fh
);
76 * Release resources related to a file handle. Parts of the V4L2
77 * framework using the v4l2_fh must release their resources here, too.
78 * Must be called in v4l2_file_operations->release() handler if the
79 * driver uses v4l2_fh.
81 void v4l2_fh_exit(struct v4l2_fh
*fh
);
83 * Can be used as the release() op of v4l2_file_operations.
84 * It deletes and exits the v4l2_fh associated with the file pointer and
85 * frees it. It will do nothing if filp->private_data (the pointer to the
86 * v4l2_fh struct) is NULL. This function always returns 0.
88 int v4l2_fh_release(struct file
*filp
);
90 * Returns 1 if this filehandle is the only filehandle opened for the
91 * associated video_device. If fh is NULL, then it returns 0.
93 int v4l2_fh_is_singular(struct v4l2_fh
*fh
);
95 * Helper function with struct file as argument. If filp->private_data is
96 * NULL, then it will return 0.
98 static inline int v4l2_fh_is_singular_file(struct file
*filp
)
100 return v4l2_fh_is_singular(filp
->private_data
);
103 #endif /* V4L2_EVENT_H */
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