1/* 2 * v4l2-fh.c 3 * 4 * V4L2 file handles. 5 * 6 * Copyright (C) 2009--2010 Nokia Corporation. 7 * 8 * Contact: Sakari Ailus <sakari.ailus@maxwell.research.nokia.com> 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License 12 * version 2 as published by the Free Software Foundation. 13 * 14 * This program is distributed in the hope that it will be useful, but 15 * WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 17 * General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License 20 * along with this program; if not, write to the Free Software 21 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 22 * 02110-1301 USA 23 */ 24 25#include <linux/bitops.h> 26#include <media/v4l2-dev.h> 27#include <media/v4l2-fh.h> 28#include <media/v4l2-event.h> 29#include <media/v4l2-ioctl.h> 30 31int v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev) 32{ 33 fh->vdev = vdev; 34 INIT_LIST_HEAD(&fh->list); 35 set_bit(V4L2_FL_USES_V4L2_FH, &fh->vdev->flags); 36 37 /* 38 * fh->events only needs to be initialized if the driver 39 * supports the VIDIOC_SUBSCRIBE_EVENT ioctl. 40 */ 41 if (vdev->ioctl_ops && vdev->ioctl_ops->vidioc_subscribe_event) 42 return v4l2_event_init(fh); 43 44 fh->events = NULL; 45 46 return 0; 47} 48EXPORT_SYMBOL_GPL(v4l2_fh_init); 49 50void v4l2_fh_add(struct v4l2_fh *fh) 51{ 52 unsigned long flags; 53 54 spin_lock_irqsave(&fh->vdev->fh_lock, flags); 55 list_add(&fh->list, &fh->vdev->fh_list); 56 spin_unlock_irqrestore(&fh->vdev->fh_lock, flags); 57} 58EXPORT_SYMBOL_GPL(v4l2_fh_add); 59 60void v4l2_fh_del(struct v4l2_fh *fh) 61{ 62 unsigned long flags; 63 64 spin_lock_irqsave(&fh->vdev->fh_lock, flags); 65 list_del_init(&fh->list); 66 spin_unlock_irqrestore(&fh->vdev->fh_lock, flags); 67} 68EXPORT_SYMBOL_GPL(v4l2_fh_del); 69 70void v4l2_fh_exit(struct v4l2_fh *fh) 71{ 72 if (fh->vdev == NULL) 73 return; 74 75 fh->vdev = NULL; 76 77 v4l2_event_free(fh); 78} 79EXPORT_SYMBOL_GPL(v4l2_fh_exit); 80