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authorSakari Ailus <sakari.ailus@maxwell.research.nokia.com>2010-03-23 09:25:26 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2010-05-19 12:58:04 -0300
commit1babcb460f2b87c20eb6860b9685a0dab636cc4b (patch)
treeaaffa67ec3b3fc958ea2d7eea50e1b67242f2645 /drivers/media/video/v4l2-fh.c
parent96d8eab5d0a1a9741a4cae1b3c125d75d1aabedf (diff)
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 <sakari.ailus@maxwell.research.nokia.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media/video/v4l2-fh.c')
-rw-r--r--drivers/media/video/v4l2-fh.c66
1 files changed, 66 insertions, 0 deletions
diff --git a/drivers/media/video/v4l2-fh.c b/drivers/media/video/v4l2-fh.c
new file mode 100644
index 000000000000..93ea0af5fac1
--- /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 <sakari.ailus@maxwell.research.nokia.com>
+ *
+ * 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 <media/v4l2-dev.h>
+#include <media/v4l2-fh.h>
+
+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);