linux/include/media/v4l2-fh.h
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   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
  31struct video_device;
  32struct v4l2_events;
  33
  34struct v4l2_fh {
  35        struct list_head        list;
  36        struct video_device     *vdev;
  37        struct v4l2_events      *events; /* events, pending and subscribed */
  38};
  39
  40/*
  41 * Initialise the file handle. Parts of the V4L2 framework using the
  42 * file handles should be initialised in this function. Must be called
  43 * from driver's v4l2_file_operations->open() handler if the driver
  44 * uses v4l2_fh.
  45 */
  46int v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev);
  47/*
  48 * Add the fh to the list of file handles on a video_device. The file
  49 * handle must be initialised first.
  50 */
  51void v4l2_fh_add(struct v4l2_fh *fh);
  52/*
  53 * Remove file handle from the list of file handles. Must be called in
  54 * v4l2_file_operations->release() handler if the driver uses v4l2_fh.
  55 */
  56void v4l2_fh_del(struct v4l2_fh *fh);
  57/*
  58 * Release resources related to a file handle. Parts of the V4L2
  59 * framework using the v4l2_fh must release their resources here, too.
  60 * Must be called in v4l2_file_operations->release() handler if the
  61 * driver uses v4l2_fh.
  62 */
  63void v4l2_fh_exit(struct v4l2_fh *fh);
  64
  65#endif /* V4L2_EVENT_H */
  66