include/media/v4l2-mc.h - linux - Git at Google

 /* SPDX-License-Identifier: GPL-2.0-or-later */
 /*
  * v4l2-mc.h - Media Controller V4L2 types and prototypes
  *
  * Copyright (C) 2016 Mauro Carvalho Chehab <mchehab@kernel.org>
  * Copyright (C) 2006-2010 Nokia Corporation
  * Copyright (c) 2016 Intel Corporation.
  */

 #ifndef _V4L2_MC_H
 #define _V4L2_MC_H

 #include <media/media-device.h>
 #include <media/v4l2-dev.h>
 #include <media/v4l2-subdev.h>
 #include <linux/types.h>

 /* We don't need to include pci.h or usb.h here */
 struct pci_dev;
 struct usb_device;

 #ifdef CONFIG_MEDIA_CONTROLLER
 /**
  * v4l2_mc_create_media_graph() - create Media Controller links at the graph.
  *
  * @mdev:	pointer to the &media_device struct.
  *
  * Add links between the entities commonly found on PC customer's hardware at
  * the V4L2 side: camera sensors, audio and video PLL-IF decoders, tuners,
  * analog TV decoder and I/O entities (video, VBI and Software Defined Radio).
  *
  * .. note::
  *
  *    Webcams are modelled on a very simple way: the sensor is
  *    connected directly to the I/O entity. All dirty details, like
  *    scaler and crop HW are hidden. While such mapping is enough for v4l2
  *    interface centric PC-consumer's hardware, V4L2 subdev centric camera
  *    hardware should not use this routine, as it will not build the right graph.
  */
 int v4l2_mc_create_media_graph(struct media_device *mdev);

 /**
  * v4l_enable_media_source() -	Hold media source for exclusive use
  *				if free
  *
  * @vdev:	pointer to struct video_device
  *
  * This interface calls enable_source handler to determine if
  * media source is free for use. The enable_source handler is
  * responsible for checking is the media source is free and
  * start a pipeline between the media source and the media
  * entity associated with the video device. This interface
  * should be called from v4l2-core and dvb-core interfaces
  * that change the source configuration.
  *
  * Return: returns zero on success or a negative error code.
  */
 int v4l_enable_media_source(struct video_device *vdev);

 /**
  * v4l_disable_media_source() -	Release media source
  *
  * @vdev:	pointer to struct video_device
  *
  * This interface calls disable_source handler to release
  * the media source. The disable_source handler stops the
  * active media pipeline between the media source and the
  * media entity associated with the video device.
  *
  * Return: returns zero on success or a negative error code.
  */
 void v4l_disable_media_source(struct video_device *vdev);

 /*
  * v4l_vb2q_enable_media_tuner -  Hold media source for exclusive use
  *				  if free.
  * @q - pointer to struct vb2_queue
  *
  * Wrapper for v4l_enable_media_source(). This function should
  * be called from v4l2-core to enable the media source with
  * pointer to struct vb2_queue as the input argument. Some
  * v4l2-core interfaces don't have access to video device and
  * this interface finds the struct video_device for the q and
  * calls v4l_enable_media_source().
  */
 int v4l_vb2q_enable_media_source(struct vb2_queue *q);

 /**
  * v4l2_create_fwnode_links_to_pad - Create fwnode-based links from a
  *                                   source subdev to a sink subdev pad.
  *
  * @src_sd - pointer to a source subdev
  * @sink - pointer to a subdev sink pad
  *
  * This function searches for fwnode endpoint connections from a source
  * subdevice to a single sink pad, and if suitable connections are found,
  * translates them into media links to that pad. The function can be
  * called by the sink subdevice, in its v4l2-async notifier subdev bound
  * callback, to create links from a bound source subdevice.
  *
  * .. note::
  *
  *    Any sink subdevice that calls this function must implement the
  *    .get_fwnode_pad media operation in order to verify endpoints passed
  *    to the sink are owned by the sink.
  *
  * Return 0 on success or a negative error code on failure.
  */
 int v4l2_create_fwnode_links_to_pad(struct v4l2_subdev *src_sd,
 				    struct media_pad *sink);

 /**
  * v4l2_create_fwnode_links - Create fwnode-based links from a source
  *                            subdev to a sink subdev.
  *
  * @src_sd - pointer to a source subdevice
  * @sink_sd - pointer to a sink subdevice
  *
  * This function searches for any and all fwnode endpoint connections
  * between source and sink subdevices, and translates them into media
  * links. The function can be called by the sink subdevice, in its
  * v4l2-async notifier subdev bound callback, to create all links from
  * a bound source subdevice.
  *
  * .. note::
  *
  *    Any sink subdevice that calls this function must implement the
  *    .get_fwnode_pad media operation in order to verify endpoints passed
  *    to the sink are owned by the sink.
  *
  * Return 0 on success or a negative error code on failure.
  */
 int v4l2_create_fwnode_links(struct v4l2_subdev *src_sd,
 			     struct v4l2_subdev *sink_sd);

 /**
  * v4l2_pipeline_pm_get - Increase the use count of a pipeline
  * @entity: The root entity of a pipeline
  *
  * Update the use count of all entities in the pipeline and power entities on.
  *
  * This function is intended to be called in video node open. It uses
  * struct media_entity.use_count to track the power status. The use
  * of this function should be paired with v4l2_pipeline_link_notify().
  *
  * Return 0 on success or a negative error code on failure.
  */
 int v4l2_pipeline_pm_get(struct media_entity *entity);

 /**
  * v4l2_pipeline_pm_put - Decrease the use count of a pipeline
  * @entity: The root entity of a pipeline
  *
  * Update the use count of all entities in the pipeline and power entities off.
  *
  * This function is intended to be called in video node release. It uses
  * struct media_entity.use_count to track the power status. The use
  * of this function should be paired with v4l2_pipeline_link_notify().
  */
 void v4l2_pipeline_pm_put(struct media_entity *entity);


 /**
  * v4l2_pipeline_link_notify - Link management notification callback
  * @link: The link
  * @flags: New link flags that will be applied
  * @notification: The link's state change notification type (MEDIA_DEV_NOTIFY_*)
  *
  * React to link management on powered pipelines by updating the use count of
  * all entities in the source and sink sides of the link. Entities are powered
  * on or off accordingly. The use of this function should be paired
  * with v4l2_pipeline_pm_{get,put}().
  *
  * Return 0 on success or a negative error code on failure. Powering entities
  * off is assumed to never fail. This function will not fail for disconnection
  * events.
  */
 int v4l2_pipeline_link_notify(struct media_link *link, u32 flags,
 			      unsigned int notification);

 #else /* CONFIG_MEDIA_CONTROLLER */

 static inline int v4l2_mc_create_media_graph(struct media_device *mdev)
 {
 	return 0;
 }

 static inline int v4l_enable_media_source(struct video_device *vdev)
 {
 	return 0;
 }

 static inline void v4l_disable_media_source(struct video_device *vdev)
 {
 }

 static inline int v4l_vb2q_enable_media_source(struct vb2_queue *q)
 {
 	return 0;
 }

 static inline int v4l2_pipeline_pm_get(struct media_entity *entity)
 {
 	return 0;
 }

 static inline void v4l2_pipeline_pm_put(struct media_entity *entity)
 {}

 static inline int v4l2_pipeline_link_notify(struct media_link *link, u32 flags,
 					    unsigned int notification)
 {
 	return 0;
 }

 #endif /* CONFIG_MEDIA_CONTROLLER */
 #endif /* _V4L2_MC_H */
	/* SPDX-License-Identifier: GPL-2.0-or-later */
	/*
	* v4l2-mc.h - Media Controller V4L2 types and prototypes
	*
	* Copyright (C) 2016 Mauro Carvalho Chehab <mchehab@kernel.org>
	* Copyright (C) 2006-2010 Nokia Corporation
	* Copyright (c) 2016 Intel Corporation.
	*/

	#ifndef _V4L2_MC_H
	#define _V4L2_MC_H

	#include <media/media-device.h>
	#include <media/v4l2-dev.h>
	#include <media/v4l2-subdev.h>
	#include <linux/types.h>

	/* We don't need to include pci.h or usb.h here */
	struct pci_dev;
	struct usb_device;

	#ifdef CONFIG_MEDIA_CONTROLLER
	/**
	* v4l2_mc_create_media_graph() - create Media Controller links at the graph.
	*
	* @mdev: pointer to the &media_device struct.
	*
	* Add links between the entities commonly found on PC customer's hardware at
	* the V4L2 side: camera sensors, audio and video PLL-IF decoders, tuners,
	* analog TV decoder and I/O entities (video, VBI and Software Defined Radio).
	*
	* .. note::
	*
	* Webcams are modelled on a very simple way: the sensor is
	* connected directly to the I/O entity. All dirty details, like
	* scaler and crop HW are hidden. While such mapping is enough for v4l2
	* interface centric PC-consumer's hardware, V4L2 subdev centric camera
	* hardware should not use this routine, as it will not build the right graph.
	*/
	int v4l2_mc_create_media_graph(struct media_device *mdev);

	/**
	* v4l_enable_media_source() - Hold media source for exclusive use
	* if free
	*
	* @vdev: pointer to struct video_device
	*
	* This interface calls enable_source handler to determine if
	* media source is free for use. The enable_source handler is
	* responsible for checking is the media source is free and
	* start a pipeline between the media source and the media
	* entity associated with the video device. This interface
	* should be called from v4l2-core and dvb-core interfaces
	* that change the source configuration.
	*
	* Return: returns zero on success or a negative error code.
	*/
	int v4l_enable_media_source(struct video_device *vdev);

	/**
	* v4l_disable_media_source() - Release media source
	*
	* @vdev: pointer to struct video_device
	*
	* This interface calls disable_source handler to release
	* the media source. The disable_source handler stops the
	* active media pipeline between the media source and the
	* media entity associated with the video device.
	*
	* Return: returns zero on success or a negative error code.
	*/
	void v4l_disable_media_source(struct video_device *vdev);

	/*
	* v4l_vb2q_enable_media_tuner - Hold media source for exclusive use
	* if free.
	* @q - pointer to struct vb2_queue
	*
	* Wrapper for v4l_enable_media_source(). This function should
	* be called from v4l2-core to enable the media source with
	* pointer to struct vb2_queue as the input argument. Some
	* v4l2-core interfaces don't have access to video device and
	* this interface finds the struct video_device for the q and
	* calls v4l_enable_media_source().
	*/
	int v4l_vb2q_enable_media_source(struct vb2_queue *q);

	/**
	* v4l2_create_fwnode_links_to_pad - Create fwnode-based links from a
	* source subdev to a sink subdev pad.
	*
	* @src_sd - pointer to a source subdev
	* @sink - pointer to a subdev sink pad
	*
	* This function searches for fwnode endpoint connections from a source
	* subdevice to a single sink pad, and if suitable connections are found,
	* translates them into media links to that pad. The function can be
	* called by the sink subdevice, in its v4l2-async notifier subdev bound
	* callback, to create links from a bound source subdevice.
	*
	* .. note::
	*
	* Any sink subdevice that calls this function must implement the
	* .get_fwnode_pad media operation in order to verify endpoints passed
	* to the sink are owned by the sink.
	*
	* Return 0 on success or a negative error code on failure.
	*/
	int v4l2_create_fwnode_links_to_pad(struct v4l2_subdev *src_sd,
	struct media_pad *sink);

	/**
	* v4l2_create_fwnode_links - Create fwnode-based links from a source
	* subdev to a sink subdev.
	*
	* @src_sd - pointer to a source subdevice
	* @sink_sd - pointer to a sink subdevice
	*
	* This function searches for any and all fwnode endpoint connections
	* between source and sink subdevices, and translates them into media
	* links. The function can be called by the sink subdevice, in its
	* v4l2-async notifier subdev bound callback, to create all links from
	* a bound source subdevice.
	*
	* .. note::
	*
	* Any sink subdevice that calls this function must implement the
	* .get_fwnode_pad media operation in order to verify endpoints passed
	* to the sink are owned by the sink.
	*
	* Return 0 on success or a negative error code on failure.
	*/
	int v4l2_create_fwnode_links(struct v4l2_subdev *src_sd,
	struct v4l2_subdev *sink_sd);

	/**
	* v4l2_pipeline_pm_get - Increase the use count of a pipeline
	* @entity: The root entity of a pipeline
	*
	* Update the use count of all entities in the pipeline and power entities on.
	*
	* This function is intended to be called in video node open. It uses
	* struct media_entity.use_count to track the power status. The use
	* of this function should be paired with v4l2_pipeline_link_notify().
	*
	* Return 0 on success or a negative error code on failure.
	*/
	int v4l2_pipeline_pm_get(struct media_entity *entity);

	/**
	* v4l2_pipeline_pm_put - Decrease the use count of a pipeline
	* @entity: The root entity of a pipeline
	*
	* Update the use count of all entities in the pipeline and power entities off.
	*
	* This function is intended to be called in video node release. It uses
	* struct media_entity.use_count to track the power status. The use
	* of this function should be paired with v4l2_pipeline_link_notify().
	*/
	void v4l2_pipeline_pm_put(struct media_entity *entity);


	/**
	* v4l2_pipeline_link_notify - Link management notification callback
	* @link: The link
	* @flags: New link flags that will be applied
	* @notification: The link's state change notification type (MEDIA_DEV_NOTIFY_*)
	*
	* React to link management on powered pipelines by updating the use count of
	* all entities in the source and sink sides of the link. Entities are powered
	* on or off accordingly. The use of this function should be paired
	* with v4l2_pipeline_pm_{get,put}().
	*
	* Return 0 on success or a negative error code on failure. Powering entities
	* off is assumed to never fail. This function will not fail for disconnection
	* events.
	*/
	int v4l2_pipeline_link_notify(struct media_link *link, u32 flags,
	unsigned int notification);

	#else /* CONFIG_MEDIA_CONTROLLER */

	static inline int v4l2_mc_create_media_graph(struct media_device *mdev)
	{
	return 0;
	}

	static inline int v4l_enable_media_source(struct video_device *vdev)
	{
	return 0;
	}

	static inline void v4l_disable_media_source(struct video_device *vdev)
	{
	}

	static inline int v4l_vb2q_enable_media_source(struct vb2_queue *q)
	{
	return 0;
	}

	static inline int v4l2_pipeline_pm_get(struct media_entity *entity)
	{
	return 0;
	}

	static inline void v4l2_pipeline_pm_put(struct media_entity *entity)
	{}

	static inline int v4l2_pipeline_link_notify(struct media_link *link, u32 flags,
	unsigned int notification)
	{
	return 0;
	}

	#endif /* CONFIG_MEDIA_CONTROLLER */
	#endif /* _V4L2_MC_H */