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 31 struct video_device; 32 struct v4l2_events; 33 34 struct 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 */ 46 int 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 */ 51 void 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 */ 56 void 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 */ 63 void v4l2_fh_exit(struct v4l2_fh *fh); 64 65 #endif /* V4L2_EVENT_H */ 66