forked from Minki/linux
28955a6156
When unregistering a V4L2 device node, make sure any filehandles that are waiting for an event are woken up. Add v4l2_event_wake_all() to v4l2-event.c and call it from video_unregister_device(). Otherwise userspace might never know that a device node was removed. [hverkuil: checkpatch: replaced 'if (vdev == NULL)' by 'if (!vdev)'] Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
209 lines
6.0 KiB
C
209 lines
6.0 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
|
|
/*
|
|
* v4l2-event.h
|
|
*
|
|
* V4L2 events.
|
|
*
|
|
* Copyright (C) 2009--2010 Nokia Corporation.
|
|
*
|
|
* Contact: Sakari Ailus <sakari.ailus@iki.fi>
|
|
*/
|
|
|
|
#ifndef V4L2_EVENT_H
|
|
#define V4L2_EVENT_H
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/videodev2.h>
|
|
#include <linux/wait.h>
|
|
|
|
struct v4l2_fh;
|
|
struct v4l2_subdev;
|
|
struct v4l2_subscribed_event;
|
|
struct video_device;
|
|
|
|
/**
|
|
* struct v4l2_kevent - Internal kernel event struct.
|
|
* @list: List node for the v4l2_fh->available list.
|
|
* @sev: Pointer to parent v4l2_subscribed_event.
|
|
* @event: The event itself.
|
|
* @ts: The timestamp of the event.
|
|
*/
|
|
struct v4l2_kevent {
|
|
struct list_head list;
|
|
struct v4l2_subscribed_event *sev;
|
|
struct v4l2_event event;
|
|
u64 ts;
|
|
};
|
|
|
|
/**
|
|
* struct v4l2_subscribed_event_ops - Subscribed event operations.
|
|
*
|
|
* @add: Optional callback, called when a new listener is added
|
|
* @del: Optional callback, called when a listener stops listening
|
|
* @replace: Optional callback that can replace event 'old' with event 'new'.
|
|
* @merge: Optional callback that can merge event 'old' into event 'new'.
|
|
*/
|
|
struct v4l2_subscribed_event_ops {
|
|
int (*add)(struct v4l2_subscribed_event *sev, unsigned int elems);
|
|
void (*del)(struct v4l2_subscribed_event *sev);
|
|
void (*replace)(struct v4l2_event *old, const struct v4l2_event *new);
|
|
void (*merge)(const struct v4l2_event *old, struct v4l2_event *new);
|
|
};
|
|
|
|
/**
|
|
* struct v4l2_subscribed_event - Internal struct representing a subscribed
|
|
* event.
|
|
*
|
|
* @list: List node for the v4l2_fh->subscribed list.
|
|
* @type: Event type.
|
|
* @id: Associated object ID (e.g. control ID). 0 if there isn't any.
|
|
* @flags: Copy of v4l2_event_subscription->flags.
|
|
* @fh: Filehandle that subscribed to this event.
|
|
* @node: List node that hooks into the object's event list
|
|
* (if there is one).
|
|
* @ops: v4l2_subscribed_event_ops
|
|
* @elems: The number of elements in the events array.
|
|
* @first: The index of the events containing the oldest available event.
|
|
* @in_use: The number of queued events.
|
|
* @events: An array of @elems events.
|
|
*/
|
|
struct v4l2_subscribed_event {
|
|
struct list_head list;
|
|
u32 type;
|
|
u32 id;
|
|
u32 flags;
|
|
struct v4l2_fh *fh;
|
|
struct list_head node;
|
|
const struct v4l2_subscribed_event_ops *ops;
|
|
unsigned int elems;
|
|
unsigned int first;
|
|
unsigned int in_use;
|
|
struct v4l2_kevent events[];
|
|
};
|
|
|
|
/**
|
|
* v4l2_event_dequeue - Dequeue events from video device.
|
|
*
|
|
* @fh: pointer to struct v4l2_fh
|
|
* @event: pointer to struct v4l2_event
|
|
* @nonblocking: if not zero, waits for an event to arrive
|
|
*/
|
|
int v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event,
|
|
int nonblocking);
|
|
|
|
/**
|
|
* v4l2_event_queue - Queue events to video device.
|
|
*
|
|
* @vdev: pointer to &struct video_device
|
|
* @ev: pointer to &struct v4l2_event
|
|
*
|
|
* The event will be queued for all &struct v4l2_fh file handlers.
|
|
*
|
|
* .. note::
|
|
* The driver's only responsibility is to fill in the type and the data
|
|
* fields. The other fields will be filled in by V4L2.
|
|
*/
|
|
void v4l2_event_queue(struct video_device *vdev, const struct v4l2_event *ev);
|
|
|
|
/**
|
|
* v4l2_event_queue_fh - Queue events to video device.
|
|
*
|
|
* @fh: pointer to &struct v4l2_fh
|
|
* @ev: pointer to &struct v4l2_event
|
|
*
|
|
*
|
|
* The event will be queued only for the specified &struct v4l2_fh file handler.
|
|
*
|
|
* .. note::
|
|
* The driver's only responsibility is to fill in the type and the data
|
|
* fields. The other fields will be filled in by V4L2.
|
|
*/
|
|
void v4l2_event_queue_fh(struct v4l2_fh *fh, const struct v4l2_event *ev);
|
|
|
|
/**
|
|
* v4l2_event_wake_all - Wake all filehandles.
|
|
*
|
|
* Used when unregistering a video device.
|
|
*
|
|
* @vdev: pointer to &struct video_device
|
|
*/
|
|
void v4l2_event_wake_all(struct video_device *vdev);
|
|
|
|
/**
|
|
* v4l2_event_pending - Check if an event is available
|
|
*
|
|
* @fh: pointer to &struct v4l2_fh
|
|
*
|
|
* Returns the number of pending events.
|
|
*/
|
|
int v4l2_event_pending(struct v4l2_fh *fh);
|
|
|
|
/**
|
|
* v4l2_event_subscribe - Subscribes to an event
|
|
*
|
|
* @fh: pointer to &struct v4l2_fh
|
|
* @sub: pointer to &struct v4l2_event_subscription
|
|
* @elems: size of the events queue
|
|
* @ops: pointer to &v4l2_subscribed_event_ops
|
|
*
|
|
* .. note::
|
|
*
|
|
* if @elems is zero, the framework will fill in a default value,
|
|
* with is currently 1 element.
|
|
*/
|
|
int v4l2_event_subscribe(struct v4l2_fh *fh,
|
|
const struct v4l2_event_subscription *sub,
|
|
unsigned int elems,
|
|
const struct v4l2_subscribed_event_ops *ops);
|
|
/**
|
|
* v4l2_event_unsubscribe - Unsubscribes to an event
|
|
*
|
|
* @fh: pointer to &struct v4l2_fh
|
|
* @sub: pointer to &struct v4l2_event_subscription
|
|
*/
|
|
int v4l2_event_unsubscribe(struct v4l2_fh *fh,
|
|
const struct v4l2_event_subscription *sub);
|
|
/**
|
|
* v4l2_event_unsubscribe_all - Unsubscribes to all events
|
|
*
|
|
* @fh: pointer to &struct v4l2_fh
|
|
*/
|
|
void v4l2_event_unsubscribe_all(struct v4l2_fh *fh);
|
|
|
|
/**
|
|
* v4l2_event_subdev_unsubscribe - Subdev variant of v4l2_event_unsubscribe()
|
|
*
|
|
* @sd: pointer to &struct v4l2_subdev
|
|
* @fh: pointer to &struct v4l2_fh
|
|
* @sub: pointer to &struct v4l2_event_subscription
|
|
*
|
|
* .. note::
|
|
*
|
|
* This function should be used for the &struct v4l2_subdev_core_ops
|
|
* %unsubscribe_event field.
|
|
*/
|
|
int v4l2_event_subdev_unsubscribe(struct v4l2_subdev *sd,
|
|
struct v4l2_fh *fh,
|
|
struct v4l2_event_subscription *sub);
|
|
/**
|
|
* v4l2_src_change_event_subscribe - helper function that calls
|
|
* v4l2_event_subscribe() if the event is %V4L2_EVENT_SOURCE_CHANGE.
|
|
*
|
|
* @fh: pointer to struct v4l2_fh
|
|
* @sub: pointer to &struct v4l2_event_subscription
|
|
*/
|
|
int v4l2_src_change_event_subscribe(struct v4l2_fh *fh,
|
|
const struct v4l2_event_subscription *sub);
|
|
/**
|
|
* v4l2_src_change_event_subdev_subscribe - Variant of v4l2_event_subscribe(),
|
|
* meant to subscribe only events of the type %V4L2_EVENT_SOURCE_CHANGE.
|
|
*
|
|
* @sd: pointer to &struct v4l2_subdev
|
|
* @fh: pointer to &struct v4l2_fh
|
|
* @sub: pointer to &struct v4l2_event_subscription
|
|
*/
|
|
int v4l2_src_change_event_subdev_subscribe(struct v4l2_subdev *sd,
|
|
struct v4l2_fh *fh,
|
|
struct v4l2_event_subscription *sub);
|
|
#endif /* V4L2_EVENT_H */
|