6e239399e5
Whenever a control changes value or state an event is sent to anyone that subscribed to it. This functionality is useful for control panels but also for applications that need to wait for (usually status) controls to change value. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
70 lines
2.0 KiB
C
70 lines
2.0 KiB
C
/*
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* v4l2-event.h
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*
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* V4L2 events.
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*
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* Copyright (C) 2009--2010 Nokia Corporation.
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*
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* Contact: Sakari Ailus <sakari.ailus@maxwell.research.nokia.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* version 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
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* 02110-1301 USA
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*/
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#ifndef V4L2_EVENT_H
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#define V4L2_EVENT_H
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#include <linux/types.h>
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#include <linux/videodev2.h>
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#include <linux/wait.h>
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struct v4l2_fh;
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struct video_device;
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struct v4l2_kevent {
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struct list_head list;
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struct v4l2_event event;
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};
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struct v4l2_subscribed_event {
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struct list_head list;
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u32 type;
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u32 id;
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};
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struct v4l2_events {
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wait_queue_head_t wait;
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struct list_head subscribed; /* Subscribed events */
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struct list_head free; /* Events ready for use */
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struct list_head available; /* Dequeueable event */
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unsigned int navailable;
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unsigned int nallocated; /* Number of allocated events */
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u32 sequence;
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};
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int v4l2_event_init(struct v4l2_fh *fh);
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int v4l2_event_alloc(struct v4l2_fh *fh, unsigned int n);
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void v4l2_event_free(struct v4l2_fh *fh);
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int v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event,
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int nonblocking);
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void v4l2_event_queue(struct video_device *vdev, const struct v4l2_event *ev);
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void v4l2_event_queue_fh(struct v4l2_fh *fh, const struct v4l2_event *ev);
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int v4l2_event_pending(struct v4l2_fh *fh);
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int v4l2_event_subscribe(struct v4l2_fh *fh,
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struct v4l2_event_subscription *sub);
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int v4l2_event_unsubscribe(struct v4l2_fh *fh,
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struct v4l2_event_subscription *sub);
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#endif /* V4L2_EVENT_H */
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