summaryrefslogtreecommitdiffstats
path: root/include/media/v4l2-event.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/media/v4l2-event.h')
-rw-r--r--include/media/v4l2-event.h199
1 files changed, 199 insertions, 0 deletions
diff --git a/include/media/v4l2-event.h b/include/media/v4l2-event.h
new file mode 100644
index 000000000..3f0281d06
--- /dev/null
+++ b/include/media/v4l2-event.h
@@ -0,0 +1,199 @@
+/* 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_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 */