xref: /linux/include/media/v4l2-fh.h (revision c3b5b0241f620a356c97d8f43343e721c718806d)
11babcb46SSakari Ailus /*
21babcb46SSakari Ailus  * v4l2-fh.h
31babcb46SSakari Ailus  *
41babcb46SSakari Ailus  * V4L2 file handle. Store per file handle data for the V4L2
51babcb46SSakari Ailus  * framework. Using file handles is optional for the drivers.
61babcb46SSakari Ailus  *
71babcb46SSakari Ailus  * Copyright (C) 2009--2010 Nokia Corporation.
81babcb46SSakari Ailus  *
91babcb46SSakari Ailus  * Contact: Sakari Ailus <sakari.ailus@maxwell.research.nokia.com>
101babcb46SSakari Ailus  *
111babcb46SSakari Ailus  * This program is free software; you can redistribute it and/or
121babcb46SSakari Ailus  * modify it under the terms of the GNU General Public License
131babcb46SSakari Ailus  * version 2 as published by the Free Software Foundation.
141babcb46SSakari Ailus  *
151babcb46SSakari Ailus  * This program is distributed in the hope that it will be useful, but
161babcb46SSakari Ailus  * WITHOUT ANY WARRANTY; without even the implied warranty of
171babcb46SSakari Ailus  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
181babcb46SSakari Ailus  * General Public License for more details.
191babcb46SSakari Ailus  *
201babcb46SSakari Ailus  * You should have received a copy of the GNU General Public License
211babcb46SSakari Ailus  * along with this program; if not, write to the Free Software
221babcb46SSakari Ailus  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
231babcb46SSakari Ailus  * 02110-1301 USA
241babcb46SSakari Ailus  */
251babcb46SSakari Ailus 
261babcb46SSakari Ailus #ifndef V4L2_FH_H
271babcb46SSakari Ailus #define V4L2_FH_H
281babcb46SSakari Ailus 
291babcb46SSakari Ailus #include <linux/list.h>
301babcb46SSakari Ailus 
311babcb46SSakari Ailus struct video_device;
32*c3b5b024SSakari Ailus struct v4l2_events;
331babcb46SSakari Ailus 
341babcb46SSakari Ailus struct v4l2_fh {
351babcb46SSakari Ailus 	struct list_head	list;
361babcb46SSakari Ailus 	struct video_device	*vdev;
37*c3b5b024SSakari Ailus 	struct v4l2_events      *events; /* events, pending and subscribed */
381babcb46SSakari Ailus };
391babcb46SSakari Ailus 
401babcb46SSakari Ailus /*
411babcb46SSakari Ailus  * Initialise the file handle. Parts of the V4L2 framework using the
421babcb46SSakari Ailus  * file handles should be initialised in this function. Must be called
431babcb46SSakari Ailus  * from driver's v4l2_file_operations->open() handler if the driver
441babcb46SSakari Ailus  * uses v4l2_fh.
451babcb46SSakari Ailus  */
461babcb46SSakari Ailus int v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev);
471babcb46SSakari Ailus /*
481babcb46SSakari Ailus  * Add the fh to the list of file handles on a video_device. The file
491babcb46SSakari Ailus  * handle must be initialised first.
501babcb46SSakari Ailus  */
511babcb46SSakari Ailus void v4l2_fh_add(struct v4l2_fh *fh);
521babcb46SSakari Ailus /*
531babcb46SSakari Ailus  * Remove file handle from the list of file handles. Must be called in
541babcb46SSakari Ailus  * v4l2_file_operations->release() handler if the driver uses v4l2_fh.
551babcb46SSakari Ailus  */
561babcb46SSakari Ailus void v4l2_fh_del(struct v4l2_fh *fh);
571babcb46SSakari Ailus /*
581babcb46SSakari Ailus  * Release resources related to a file handle. Parts of the V4L2
591babcb46SSakari Ailus  * framework using the v4l2_fh must release their resources here, too.
601babcb46SSakari Ailus  * Must be called in v4l2_file_operations->release() handler if the
611babcb46SSakari Ailus  * driver uses v4l2_fh.
621babcb46SSakari Ailus  */
631babcb46SSakari Ailus void v4l2_fh_exit(struct v4l2_fh *fh);
641babcb46SSakari Ailus 
651babcb46SSakari Ailus #endif /* V4L2_EVENT_H */
66