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@iki.fi> 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 <linux/slab.h> 27 #include <linux/export.h> 28 #include <media/v4l2-dev.h> 29 #include <media/v4l2-fh.h> 30 #include <media/v4l2-event.h> 31 #include <media/v4l2-ioctl.h> 32 #include <media/v4l2-mc.h> 33 34 void v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev) 35 { 36 fh->vdev = vdev; 37 /* Inherit from video_device. May be overridden by the driver. */ 38 fh->ctrl_handler = vdev->ctrl_handler; 39 INIT_LIST_HEAD(&fh->list); 40 set_bit(V4L2_FL_USES_V4L2_FH, &fh->vdev->flags); 41 /* 42 * determine_valid_ioctls() does not know if struct v4l2_fh 43 * is used by this driver, but here we do. So enable the 44 * prio ioctls here. 45 */ 46 set_bit(_IOC_NR(VIDIOC_G_PRIORITY), vdev->valid_ioctls); 47 set_bit(_IOC_NR(VIDIOC_S_PRIORITY), vdev->valid_ioctls); 48 fh->prio = V4L2_PRIORITY_UNSET; 49 init_waitqueue_head(&fh->wait); 50 INIT_LIST_HEAD(&fh->available); 51 INIT_LIST_HEAD(&fh->subscribed); 52 fh->sequence = -1; 53 } 54 EXPORT_SYMBOL_GPL(v4l2_fh_init); 55 56 void v4l2_fh_add(struct v4l2_fh *fh) 57 { 58 unsigned long flags; 59 60 v4l2_prio_open(fh->vdev->prio, &fh->prio); 61 spin_lock_irqsave(&fh->vdev->fh_lock, flags); 62 list_add(&fh->list, &fh->vdev->fh_list); 63 spin_unlock_irqrestore(&fh->vdev->fh_lock, flags); 64 } 65 EXPORT_SYMBOL_GPL(v4l2_fh_add); 66 67 int v4l2_fh_open(struct file *filp) 68 { 69 struct video_device *vdev = video_devdata(filp); 70 struct v4l2_fh *fh = kzalloc(sizeof(*fh), GFP_KERNEL); 71 72 filp->private_data = fh; 73 if (fh == NULL) 74 return -ENOMEM; 75 v4l2_fh_init(fh, vdev); 76 v4l2_fh_add(fh); 77 return 0; 78 } 79 EXPORT_SYMBOL_GPL(v4l2_fh_open); 80 81 void v4l2_fh_del(struct v4l2_fh *fh) 82 { 83 unsigned long flags; 84 85 spin_lock_irqsave(&fh->vdev->fh_lock, flags); 86 list_del_init(&fh->list); 87 spin_unlock_irqrestore(&fh->vdev->fh_lock, flags); 88 v4l2_prio_close(fh->vdev->prio, fh->prio); 89 } 90 EXPORT_SYMBOL_GPL(v4l2_fh_del); 91 92 void v4l2_fh_exit(struct v4l2_fh *fh) 93 { 94 if (fh->vdev == NULL) 95 return; 96 v4l_disable_media_source(fh->vdev); 97 v4l2_event_unsubscribe_all(fh); 98 fh->vdev = NULL; 99 } 100 EXPORT_SYMBOL_GPL(v4l2_fh_exit); 101 102 int v4l2_fh_release(struct file *filp) 103 { 104 struct v4l2_fh *fh = filp->private_data; 105 106 if (fh) { 107 v4l2_fh_del(fh); 108 v4l2_fh_exit(fh); 109 kfree(fh); 110 } 111 return 0; 112 } 113 EXPORT_SYMBOL_GPL(v4l2_fh_release); 114 115 int v4l2_fh_is_singular(struct v4l2_fh *fh) 116 { 117 unsigned long flags; 118 int is_singular; 119 120 if (fh == NULL || fh->vdev == NULL) 121 return 0; 122 spin_lock_irqsave(&fh->vdev->fh_lock, flags); 123 is_singular = list_is_singular(&fh->list); 124 spin_unlock_irqrestore(&fh->vdev->fh_lock, flags); 125 return is_singular; 126 } 127 EXPORT_SYMBOL_GPL(v4l2_fh_is_singular); 128