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Diffstat (limited to 'drivers/media/v4l2-core/v4l2-fh.c')
-rw-r--r--drivers/media/v4l2-core/v4l2-fh.c120
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 000000000000..9e3fc040ea20
--- /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@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 <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);

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