linux-stable/include/media/v4l2-event.h
Mauro Carvalho Chehab e383ce0736 [media] get rid of a number of problems at the cross references
As warned by linuxdoc[1] tool, using:

$ for i in $(git grep kernel-doc Documentation/media/kapi/|cut -d: -f4); do kernel-lintdoc --sloppy $i; done

    include/media/v4l2-dev.h:118 :WARN: function name from comment differs:  v4l2_prio_close <--> v4l2_prio_check
    include/media/v4l2-mc.h:56 [kernel-doc WARN] : enum name from comment differs:  if_vid_dec_index <--> if_vid_dec_pad_index
    include/media/v4l2-mc.h:71 [kernel-doc WARN] : enum name from comment differs:  if_aud_dec_index <--> if_aud_dec_pad_index
    include/media/v4l2-mem2mem.h:396 [kernel-doc WARN] : function name from comment differs:  v4l2_m2m_num_src_bufs_ready <--> v4l2_m2m_num_dst_bufs_ready
    drivers/media/dvb-core/dvb_math.h:28 [kernel-doc WARN] : function name from comment differs:  cintlog2 <--> intlog2
    include/media/v4l2-subdev.h:215 [kernel-doc WARN] : struct name from comment differs:  s_radio <--> v4l2_subdev_tuner_ops
    include/media/v4l2-subdev.h:890 [kernel-doc WARN] : function name from comment differs:  v4l2_set_subdevdata <--> v4l2_set_subdev_hostdata
    include/media/v4l2-subdev.h:901 [kernel-doc WARN] : function name from comment differs:  v4l2_get_subdevdata <--> v4l2_get_subdev_hostdata
    drivers/media/dvb-core/dvb_ringbuffer.h:196 [kernel-doc WARN] : function name from comment differs:  dvb_ringbuffer_writeuser <--> dvb_ringbuffer_write_user
    include/media/videobuf2-core.h:399 [kernel-doc WARN] : struct name from comment differs:  vb2_ops <--> vb2_buf_ops
    include/media/media-entity.h:132 [kernel-doc ERROR] : duplicate parameter definition 'source'
    include/media/media-entity.h:477 [kernel-doc WARN] : function name from comment differs:  media_entity_enum_test <--> media_entity_enum_test_and_set
    include/media/media-entity.h:535 [kernel-doc WARN] : function name from comment differs:  gobj_to_entity <--> gobj_to_pad
    include/media/media-entity.h:544 [kernel-doc WARN] : function name from comment differs:  gobj_to_entity <--> gobj_to_link
    include/media/media-entity.h:553 [kernel-doc WARN] : function name from comment differs:  gobj_to_entity <--> gobj_to_intf
    include/media/media-entity.h:562 [kernel-doc WARN] : function name from comment differs:  gobj_to_entity <--> intf_to_devnode
    include/media/rc-core.h:234 [kernel-doc WARN] : function name from comment differs:  rc_open <--> rc_close
    include/media/v4l2-ctrls.h:397 [kernel-doc WARN] : missing initial short description of 'v4l2_ctrl_handler_init'
    include/media/v4l2-dev.h:118 [kernel-doc WARN] : function name from comment differs:  v4l2_prio_close <--> v4l2_prio_check
    include/media/v4l2-event.h:225 [kernel-doc WARN] : missing initial short description of 'v4l2_src_change_event_subscribe'

[1] https://return42.github.io/linuxdoc/linux.html

The above are real issues at the documentation. On several cases,
caused by cut-and-paste.

 Fix them.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-09-22 10:00:23 -03:00

244 lines
7.8 KiB
C

/*
* v4l2-event.h
*
* V4L2 events.
*
* Copyright (C) 2009--2010 Nokia Corporation.
*
* Contact: Sakari Ailus <sakari.ailus@iki.fi>
*
* 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
*/
#ifndef V4L2_EVENT_H
#define V4L2_EVENT_H
#include <linux/types.h>
#include <linux/videodev2.h>
#include <linux/wait.h>
/*
* Overview:
*
* Events are subscribed per-filehandle. An event specification consists of a
* type and is optionally associated with an object identified through the
* 'id' field. So an event is uniquely identified by the (type, id) tuple.
*
* The v4l2-fh struct has a list of subscribed events. The v4l2_subscribed_event
* struct is added to that list, one for every subscribed event.
*
* Each v4l2_subscribed_event struct ends with an array of v4l2_kevent structs.
* This array (ringbuffer, really) is used to store any events raised by the
* driver. The v4l2_kevent struct links into the 'available' list of the
* v4l2_fh struct so VIDIOC_DQEVENT will know which event to dequeue first.
*
* Finally, if the event subscription is associated with a particular object
* such as a V4L2 control, then that object needs to know about that as well
* so that an event can be raised by that object. So the 'node' field can
* be used to link the v4l2_subscribed_event struct into a list of that
* object.
*
* So to summarize:
*
* struct v4l2_fh has two lists: one of the subscribed events, and one of the
* pending events.
*
* struct v4l2_subscribed_event has a ringbuffer of raised (pending) events of
* that particular type.
*
* If struct v4l2_subscribed_event is associated with a specific object, then
* that object will have an internal list of struct v4l2_subscribed_event so
* it knows who subscribed an event to that object.
*/
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.
*/
struct v4l2_kevent {
struct list_head list;
struct v4l2_subscribed_event *sev;
struct v4l2_event event;
};
/**
* 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 */