linux-stable/include/media/v4l2-fh.h
Sakari Ailus c3b5b0241f V4L/DVB: V4L: Events: Add backend
Add event handling backend to V4L2. The backend handles event subscription
and delivery to file handles. Event subscriptions are based on file handle.
Events may be delivered to all subscribed file handles on a device
independent of where they originate from.

Signed-off-by: Sakari Ailus <sakari.ailus@maxwell.research.nokia.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2010-05-19 12:58:06 -03:00

65 lines
2.1 KiB
C

/*
* 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@maxwell.research.nokia.com>
*
* 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/list.h>
struct video_device;
struct v4l2_events;
struct v4l2_fh {
struct list_head list;
struct video_device *vdev;
struct v4l2_events *events; /* events, pending and subscribed */
};
/*
* Initialise the file handle. 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 v4l2_fh.
*/
int v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev);
/*
* Add the fh to the list of file handles on a video_device. The file
* handle must be initialised first.
*/
void v4l2_fh_add(struct v4l2_fh *fh);
/*
* Remove file handle from the list of file handles. Must be called in
* v4l2_file_operations->release() handler if the driver uses v4l2_fh.
*/
void v4l2_fh_del(struct v4l2_fh *fh);
/*
* Release resources related to a file handle. Parts of the V4L2
* framework using the v4l2_fh must release their resources here, too.
* Must be called in v4l2_file_operations->release() handler if the
* driver uses v4l2_fh.
*/
void v4l2_fh_exit(struct v4l2_fh *fh);
#endif /* V4L2_EVENT_H */