diff options
Diffstat (limited to 'drivers/media/v4l2-core/v4l2-fh.c')
| -rw-r--r-- | drivers/media/v4l2-core/v4l2-fh.c | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/drivers/media/v4l2-core/v4l2-fh.c b/drivers/media/v4l2-core/v4l2-fh.c new file mode 100644 index 00000000000..e57c002b415 --- /dev/null +++ b/drivers/media/v4l2-core/v4l2-fh.c @@ -0,0 +1,120 @@ +/* + * v4l2-fh.c + * + * V4L2 file handles. + * + * Copyright (C) 2009--2010 Nokia Corporation. + * + * Contact: Sakari Ailus <sakari.ailus@iki.fi> + * + * 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 + */ + +#include <linux/bitops.h> +#include <linux/slab.h> +#include <linux/export.h> +#include <media/v4l2-dev.h> +#include <media/v4l2-fh.h> +#include <media/v4l2-event.h> +#include <media/v4l2-ioctl.h> + +void v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev) +{ + fh->vdev = vdev; + /* Inherit from video_device. May be overridden by the driver. */ + fh->ctrl_handler = vdev->ctrl_handler; + INIT_LIST_HEAD(&fh->list); + set_bit(V4L2_FL_USES_V4L2_FH, &fh->vdev->flags); + fh->prio = V4L2_PRIORITY_UNSET; + init_waitqueue_head(&fh->wait); + INIT_LIST_HEAD(&fh->available); + INIT_LIST_HEAD(&fh->subscribed); + fh->sequence = -1; +} +EXPORT_SYMBOL_GPL(v4l2_fh_init); + +void v4l2_fh_add(struct v4l2_fh *fh) +{ + unsigned long flags; + + if (test_bit(V4L2_FL_USE_FH_PRIO, &fh->vdev->flags)) + v4l2_prio_open(fh->vdev->prio, &fh->prio); + spin_lock_irqsave(&fh->vdev->fh_lock, flags); + list_add(&fh->list, &fh->vdev->fh_list); + spin_unlock_irqrestore(&fh->vdev->fh_lock, flags); +} +EXPORT_SYMBOL_GPL(v4l2_fh_add); + +int v4l2_fh_open(struct file *filp) +{ + struct video_device *vdev = video_devdata(filp); + struct v4l2_fh *fh = kzalloc(sizeof(*fh), GFP_KERNEL); + + filp->private_data = fh; + if (fh == NULL) + return -ENOMEM; + v4l2_fh_init(fh, vdev); + v4l2_fh_add(fh); + return 0; +} +EXPORT_SYMBOL_GPL(v4l2_fh_open); + +void v4l2_fh_del(struct v4l2_fh *fh) +{ + unsigned long flags; + + spin_lock_irqsave(&fh->vdev->fh_lock, flags); + list_del_init(&fh->list); + spin_unlock_irqrestore(&fh->vdev->fh_lock, flags); + if (test_bit(V4L2_FL_USE_FH_PRIO, &fh->vdev->flags)) + v4l2_prio_close(fh->vdev->prio, fh->prio); +} +EXPORT_SYMBOL_GPL(v4l2_fh_del); + +void v4l2_fh_exit(struct v4l2_fh *fh) +{ + if (fh->vdev == NULL) + return; + v4l2_event_unsubscribe_all(fh); + fh->vdev = NULL; +} +EXPORT_SYMBOL_GPL(v4l2_fh_exit); + +int v4l2_fh_release(struct file *filp) +{ + struct v4l2_fh *fh = filp->private_data; + + if (fh) { + v4l2_fh_del(fh); + v4l2_fh_exit(fh); + kfree(fh); + } + return 0; +} +EXPORT_SYMBOL_GPL(v4l2_fh_release); + +int v4l2_fh_is_singular(struct v4l2_fh *fh) +{ + unsigned long flags; + int is_singular; + + if (fh == NULL || fh->vdev == NULL) + return 0; + spin_lock_irqsave(&fh->vdev->fh_lock, flags); + is_singular = list_is_singular(&fh->list); + spin_unlock_irqrestore(&fh->vdev->fh_lock, flags); + return is_singular; +} +EXPORT_SYMBOL_GPL(v4l2_fh_is_singular); |