From 1babcb460f2b87c20eb6860b9685a0dab636cc4b Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Tue, 23 Mar 2010 09:25:26 -0300 Subject: V4L/DVB: V4L: File handles This patch adds a list of v4l2_fh structures to every video_device. It allows using file handle related information in V4L2. The event interface is one example of such use. The use of v4l2_fh is not mandatory for drivers. Signed-off-by: Sakari Ailus Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/v4l2-fh.c | 66 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 66 insertions(+) create mode 100644 drivers/media/video/v4l2-fh.c (limited to 'drivers/media/video/v4l2-fh.c') diff --git a/drivers/media/video/v4l2-fh.c b/drivers/media/video/v4l2-fh.c new file mode 100644 index 00000000000..93ea0af5fac --- /dev/null +++ b/drivers/media/video/v4l2-fh.c @@ -0,0 +1,66 @@ +/* + * v4l2-fh.c + * + * V4L2 file handles. + * + * Copyright (C) 2009--2010 Nokia Corporation. + * + * Contact: Sakari Ailus + * + * 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 +#include +#include + +int v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev) +{ + fh->vdev = vdev; + INIT_LIST_HEAD(&fh->list); + set_bit(V4L2_FL_USES_V4L2_FH, &fh->vdev->flags); + + return 0; +} +EXPORT_SYMBOL_GPL(v4l2_fh_init); + +void v4l2_fh_add(struct v4l2_fh *fh) +{ + unsigned long flags; + + 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); + +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); +} +EXPORT_SYMBOL_GPL(v4l2_fh_del); + +void v4l2_fh_exit(struct v4l2_fh *fh) +{ + if (fh->vdev == NULL) + return; + + fh->vdev = NULL; +} +EXPORT_SYMBOL_GPL(v4l2_fh_exit); -- cgit v1.2.3-70-g09d2