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

 /* SPDX-License-Identifier: GPL-2.0-only */
 /*
  * V4L2 fwnode binding parsing library
  *
  * Copyright (c) 2016 Intel Corporation.
  * Author: Sakari Ailus <sakari.ailus@linux.intel.com>
  *
  * Copyright (C) 2012 - 2013 Samsung Electronics Co., Ltd.
  * Author: Sylwester Nawrocki <s.nawrocki@samsung.com>
  *
  * Copyright (C) 2012 Renesas Electronics Corp.
  * Author: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
  */
 #ifndef _V4L2_FWNODE_H
 #define _V4L2_FWNODE_H

 #include <linux/errno.h>
 #include <linux/fwnode.h>
 #include <linux/list.h>
 #include <linux/types.h>

 #include <media/v4l2-mediabus.h>
 #include <media/v4l2-subdev.h>

 struct fwnode_handle;
 struct v4l2_async_notifier;
 struct v4l2_async_subdev;

 #define V4L2_FWNODE_CSI2_MAX_DATA_LANES	4

 /**
  * struct v4l2_fwnode_bus_mipi_csi2 - MIPI CSI-2 bus data structure
  * @flags: media bus (V4L2_MBUS_*) flags
  * @data_lanes: an array of physical data lane indexes
  * @clock_lane: physical lane index of the clock lane
  * @num_data_lanes: number of data lanes
  * @lane_polarities: polarity of the lanes. The order is the same of
  *		   the physical lanes.
  */
 struct v4l2_fwnode_bus_mipi_csi2 {
 	unsigned int flags;
 	unsigned char data_lanes[V4L2_FWNODE_CSI2_MAX_DATA_LANES];
 	unsigned char clock_lane;
 	unsigned short num_data_lanes;
 	bool lane_polarities[1 + V4L2_FWNODE_CSI2_MAX_DATA_LANES];
 };

 /**
  * struct v4l2_fwnode_bus_parallel - parallel data bus data structure
  * @flags: media bus (V4L2_MBUS_*) flags
  * @bus_width: bus width in bits
  * @data_shift: data shift in bits
  */
 struct v4l2_fwnode_bus_parallel {
 	unsigned int flags;
 	unsigned char bus_width;
 	unsigned char data_shift;
 };

 /**
  * struct v4l2_fwnode_bus_mipi_csi1 - CSI-1/CCP2 data bus structure
  * @clock_inv: polarity of clock/strobe signal
  *	       false - not inverted, true - inverted
  * @strobe: false - data/clock, true - data/strobe
  * @lane_polarity: the polarities of the clock (index 0) and data lanes
  *		   index (1)
  * @data_lane: the number of the data lane
  * @clock_lane: the number of the clock lane
  */
 struct v4l2_fwnode_bus_mipi_csi1 {
 	unsigned char clock_inv:1;
 	unsigned char strobe:1;
 	bool lane_polarity[2];
 	unsigned char data_lane;
 	unsigned char clock_lane;
 };

 /**
  * struct v4l2_fwnode_endpoint - the endpoint data structure
  * @base: fwnode endpoint of the v4l2_fwnode
  * @bus_type: bus type
  * @bus: union with bus configuration data structure
  * @bus.parallel: embedded &struct v4l2_fwnode_bus_parallel.
  *		  Used if the bus is parallel.
  * @bus.mipi_csi1: embedded &struct v4l2_fwnode_bus_mipi_csi1.
  *		   Used if the bus is MIPI Alliance's Camera Serial
  *		   Interface version 1 (MIPI CSI1) or Standard
  *		   Mobile Imaging Architecture's Compact Camera Port 2
  *		   (SMIA CCP2).
  * @bus.mipi_csi2: embedded &struct v4l2_fwnode_bus_mipi_csi2.
  *		   Used if the bus is MIPI Alliance's Camera Serial
  *		   Interface version 2 (MIPI CSI2).
  * @link_frequencies: array of supported link frequencies
  * @nr_of_link_frequencies: number of elements in link_frequenccies array
  */
 struct v4l2_fwnode_endpoint {
 	struct fwnode_endpoint base;
 	/*
 	 * Fields below this line will be zeroed by
 	 * v4l2_fwnode_endpoint_parse()
 	 */
 	enum v4l2_mbus_type bus_type;
 	union {
 		struct v4l2_fwnode_bus_parallel parallel;
 		struct v4l2_fwnode_bus_mipi_csi1 mipi_csi1;
 		struct v4l2_fwnode_bus_mipi_csi2 mipi_csi2;
 	} bus;
 	u64 *link_frequencies;
 	unsigned int nr_of_link_frequencies;
 };

 /**
  * struct v4l2_fwnode_link - a link between two endpoints
  * @local_node: pointer to device_node of this endpoint
  * @local_port: identifier of the port this endpoint belongs to
  * @remote_node: pointer to device_node of the remote endpoint
  * @remote_port: identifier of the port the remote endpoint belongs to
  */
 struct v4l2_fwnode_link {
 	struct fwnode_handle *local_node;
 	unsigned int local_port;
 	struct fwnode_handle *remote_node;
 	unsigned int remote_port;
 };

 /**
  * v4l2_fwnode_endpoint_parse() - parse all fwnode node properties
  * @fwnode: pointer to the endpoint's fwnode handle
  * @vep: pointer to the V4L2 fwnode data structure
  *
  * This function parses the V4L2 fwnode endpoint specific parameters from the
  * firmware. The caller is responsible for assigning @vep.bus_type to a valid
  * media bus type. The caller may also set the default configuration for the
  * endpoint --- a configuration that shall be in line with the DT binding
  * documentation. Should a device support multiple bus types, the caller may
  * call this function once the correct type is found --- with a default
  * configuration valid for that type.
  *
  * As a compatibility means guessing the bus type is also supported by setting
  * @vep.bus_type to V4L2_MBUS_UNKNOWN. The caller may not provide a default
  * configuration in this case as the defaults are specific to a given bus type.
  * This functionality is deprecated and should not be used in new drivers and it
  * is only supported for CSI-2 D-PHY, parallel and Bt.656 buses.
  *
  * The function does not change the V4L2 fwnode endpoint state if it fails.
  *
  * NOTE: This function does not parse properties the size of which is variable
  * without a low fixed limit. Please use v4l2_fwnode_endpoint_alloc_parse() in
  * new drivers instead.
  *
  * Return: %0 on success or a negative error code on failure:
  *	   %-ENOMEM on memory allocation failure
  *	   %-EINVAL on parsing failure
  *	   %-ENXIO on mismatching bus types
  */
 int v4l2_fwnode_endpoint_parse(struct fwnode_handle *fwnode,
 			       struct v4l2_fwnode_endpoint *vep);

 /**
  * v4l2_fwnode_endpoint_free() - free the V4L2 fwnode acquired by
  * v4l2_fwnode_endpoint_alloc_parse()
  * @vep: the V4L2 fwnode the resources of which are to be released
  *
  * It is safe to call this function with NULL argument or on a V4L2 fwnode the
  * parsing of which failed.
  */
 void v4l2_fwnode_endpoint_free(struct v4l2_fwnode_endpoint *vep);

 /**
  * v4l2_fwnode_endpoint_alloc_parse() - parse all fwnode node properties
  * @fwnode: pointer to the endpoint's fwnode handle
  * @vep: pointer to the V4L2 fwnode data structure
  *
  * This function parses the V4L2 fwnode endpoint specific parameters from the
  * firmware. The caller is responsible for assigning @vep.bus_type to a valid
  * media bus type. The caller may also set the default configuration for the
  * endpoint --- a configuration that shall be in line with the DT binding
  * documentation. Should a device support multiple bus types, the caller may
  * call this function once the correct type is found --- with a default
  * configuration valid for that type.
  *
  * As a compatibility means guessing the bus type is also supported by setting
  * @vep.bus_type to V4L2_MBUS_UNKNOWN. The caller may not provide a default
  * configuration in this case as the defaults are specific to a given bus type.
  * This functionality is deprecated and should not be used in new drivers and it
  * is only supported for CSI-2 D-PHY, parallel and Bt.656 buses.
  *
  * The function does not change the V4L2 fwnode endpoint state if it fails.
  *
  * v4l2_fwnode_endpoint_alloc_parse() has two important differences to
  * v4l2_fwnode_endpoint_parse():
  *
  * 1. It also parses variable size data.
  *
  * 2. The memory it has allocated to store the variable size data must be freed
  *    using v4l2_fwnode_endpoint_free() when no longer needed.
  *
  * Return: %0 on success or a negative error code on failure:
  *	   %-ENOMEM on memory allocation failure
  *	   %-EINVAL on parsing failure
  *	   %-ENXIO on mismatching bus types
  */
 int v4l2_fwnode_endpoint_alloc_parse(struct fwnode_handle *fwnode,
 				     struct v4l2_fwnode_endpoint *vep);

 /**
  * v4l2_fwnode_parse_link() - parse a link between two endpoints
  * @fwnode: pointer to the endpoint's fwnode at the local end of the link
  * @link: pointer to the V4L2 fwnode link data structure
  *
  * Fill the link structure with the local and remote nodes and port numbers.
  * The local_node and remote_node fields are set to point to the local and
  * remote port's parent nodes respectively (the port parent node being the
  * parent node of the port node if that node isn't a 'ports' node, or the
  * grand-parent node of the port node otherwise).
  *
  * A reference is taken to both the local and remote nodes, the caller must use
  * v4l2_fwnode_put_link() to drop the references when done with the
  * link.
  *
  * Return: 0 on success, or -ENOLINK if the remote endpoint fwnode can't be
  * found.
  */
 int v4l2_fwnode_parse_link(struct fwnode_handle *fwnode,
 			   struct v4l2_fwnode_link *link);

 /**
  * v4l2_fwnode_put_link() - drop references to nodes in a link
  * @link: pointer to the V4L2 fwnode link data structure
  *
  * Drop references to the local and remote nodes in the link. This function
  * must be called on every link parsed with v4l2_fwnode_parse_link().
  */
 void v4l2_fwnode_put_link(struct v4l2_fwnode_link *link);

 /**
  * typedef parse_endpoint_func - Driver's callback function to be called on
  *	each V4L2 fwnode endpoint.
  *
  * @dev: pointer to &struct device
  * @vep: pointer to &struct v4l2_fwnode_endpoint
  * @asd: pointer to &struct v4l2_async_subdev
  *
  * Return:
  * * %0 on success
  * * %-ENOTCONN if the endpoint is to be skipped but this
  *   should not be considered as an error
  * * %-EINVAL if the endpoint configuration is invalid
  */
 typedef int (*parse_endpoint_func)(struct device *dev,
 				  struct v4l2_fwnode_endpoint *vep,
 				  struct v4l2_async_subdev *asd);

 /**
  * v4l2_async_notifier_parse_fwnode_endpoints - Parse V4L2 fwnode endpoints in a
  *						device node
  * @dev: the device the endpoints of which are to be parsed
  * @notifier: notifier for @dev
  * @asd_struct_size: size of the driver's async sub-device struct, including
  *		     sizeof(struct v4l2_async_subdev). The &struct
  *		     v4l2_async_subdev shall be the first member of
  *		     the driver's async sub-device struct, i.e. both
  *		     begin at the same memory address.
  * @parse_endpoint: Driver's callback function called on each V4L2 fwnode
  *		    endpoint. Optional.
  *
  * Parse the fwnode endpoints of the @dev device and populate the async sub-
  * devices list in the notifier. The @parse_endpoint callback function is
  * called for each endpoint with the corresponding async sub-device pointer to
  * let the caller initialize the driver-specific part of the async sub-device
  * structure.
  *
  * The notifier memory shall be zeroed before this function is called on the
  * notifier.
  *
  * This function may not be called on a registered notifier and may be called on
  * a notifier only once.
  *
  * The &struct v4l2_fwnode_endpoint passed to the callback function
  * @parse_endpoint is released once the function is finished. If there is a need
  * to retain that configuration, the user needs to allocate memory for it.
  *
  * Any notifier populated using this function must be released with a call to
  * v4l2_async_notifier_cleanup() after it has been unregistered and the async
  * sub-devices are no longer in use, even if the function returned an error.
  *
  * Return: %0 on success, including when no async sub-devices are found
  *	   %-ENOMEM if memory allocation failed
  *	   %-EINVAL if graph or endpoint parsing failed
  *	   Other error codes as returned by @parse_endpoint
  */
 int
 v4l2_async_notifier_parse_fwnode_endpoints(struct device *dev,
 					   struct v4l2_async_notifier *notifier,
 					   size_t asd_struct_size,
 					   parse_endpoint_func parse_endpoint);

 /**
  * v4l2_async_notifier_parse_fwnode_endpoints_by_port - Parse V4L2 fwnode
  *							endpoints of a port in a
  *							device node
  * @dev: the device the endpoints of which are to be parsed
  * @notifier: notifier for @dev
  * @asd_struct_size: size of the driver's async sub-device struct, including
  *		     sizeof(struct v4l2_async_subdev). The &struct
  *		     v4l2_async_subdev shall be the first member of
  *		     the driver's async sub-device struct, i.e. both
  *		     begin at the same memory address.
  * @port: port number where endpoints are to be parsed
  * @parse_endpoint: Driver's callback function called on each V4L2 fwnode
  *		    endpoint. Optional.
  *
  * This function is just like v4l2_async_notifier_parse_fwnode_endpoints() with
  * the exception that it only parses endpoints in a given port. This is useful
  * on devices that have both sinks and sources: the async sub-devices connected
  * to sources have already been configured by another driver (on capture
  * devices). In this case the driver must know which ports to parse.
  *
  * Parse the fwnode endpoints of the @dev device on a given @port and populate
  * the async sub-devices list of the notifier. The @parse_endpoint callback
  * function is called for each endpoint with the corresponding async sub-device
  * pointer to let the caller initialize the driver-specific part of the async
  * sub-device structure.
  *
  * The notifier memory shall be zeroed before this function is called on the
  * notifier the first time.
  *
  * This function may not be called on a registered notifier and may be called on
  * a notifier only once per port.
  *
  * The &struct v4l2_fwnode_endpoint passed to the callback function
  * @parse_endpoint is released once the function is finished. If there is a need
  * to retain that configuration, the user needs to allocate memory for it.
  *
  * Any notifier populated using this function must be released with a call to
  * v4l2_async_notifier_cleanup() after it has been unregistered and the async
  * sub-devices are no longer in use, even if the function returned an error.
  *
  * Return: %0 on success, including when no async sub-devices are found
  *	   %-ENOMEM if memory allocation failed
  *	   %-EINVAL if graph or endpoint parsing failed
  *	   Other error codes as returned by @parse_endpoint
  */
 int
 v4l2_async_notifier_parse_fwnode_endpoints_by_port(struct device *dev,
 						   struct v4l2_async_notifier *notifier,
 						   size_t asd_struct_size,
 						   unsigned int port,
 						   parse_endpoint_func parse_endpoint);

 /**
  * v4l2_fwnode_reference_parse_sensor_common - parse common references on
  *					       sensors for async sub-devices
  * @dev: the device node the properties of which are parsed for references
  * @notifier: the async notifier where the async subdevs will be added
  *
  * Parse common sensor properties for remote devices related to the
  * sensor and set up async sub-devices for them.
  *
  * Any notifier populated using this function must be released with a call to
  * v4l2_async_notifier_release() after it has been unregistered and the async
  * sub-devices are no longer in use, even in the case the function returned an
  * error.
  *
  * Return: 0 on success
  *	   -ENOMEM if memory allocation failed
  *	   -EINVAL if property parsing failed
  */
 int v4l2_async_notifier_parse_fwnode_sensor_common(struct device *dev,
 						   struct v4l2_async_notifier *notifier);

 /**
  * v4l2_async_register_fwnode_subdev - registers a sub-device to the
  *					asynchronous sub-device framework
  *					and parses fwnode endpoints
  *
  * @sd: pointer to struct &v4l2_subdev
  * @asd_struct_size: size of the driver's async sub-device struct, including
  *		     sizeof(struct v4l2_async_subdev). The &struct
  *		     v4l2_async_subdev shall be the first member of
  *		     the driver's async sub-device struct, i.e. both
  *		     begin at the same memory address.
  * @ports: array of port id's to parse for fwnode endpoints. If NULL, will
  *	   parse all ports owned by the sub-device.
  * @num_ports: number of ports in @ports array. Ignored if @ports is NULL.
  * @parse_endpoint: Driver's callback function called on each V4L2 fwnode
  *		    endpoint. Optional.
  *
  * This function is just like v4l2_async_register_subdev() with the
  * exception that calling it will also allocate a notifier for the
  * sub-device, parse the sub-device's firmware node endpoints using
  * v4l2_async_notifier_parse_fwnode_endpoints() or
  * v4l2_async_notifier_parse_fwnode_endpoints_by_port(), and
  * registers the sub-device notifier. The sub-device is similarly
  * unregistered by calling v4l2_async_unregister_subdev().
  *
  * While registered, the subdev module is marked as in-use.
  *
  * An error is returned if the module is no longer loaded on any attempts
  * to register it.
  */
 int
 v4l2_async_register_fwnode_subdev(struct v4l2_subdev *sd,
 				  size_t asd_struct_size,
 				  unsigned int *ports,
 				  unsigned int num_ports,
 				  parse_endpoint_func parse_endpoint);

 #endif /* _V4L2_FWNODE_H */
	/* SPDX-License-Identifier: GPL-2.0-only */
	/*
	* V4L2 fwnode binding parsing library
	*
	* Copyright (c) 2016 Intel Corporation.
	* Author: Sakari Ailus <sakari.ailus@linux.intel.com>
	*
	* Copyright (C) 2012 - 2013 Samsung Electronics Co., Ltd.
	* Author: Sylwester Nawrocki <s.nawrocki@samsung.com>
	*
	* Copyright (C) 2012 Renesas Electronics Corp.
	* Author: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
	*/
	#ifndef _V4L2_FWNODE_H
	#define _V4L2_FWNODE_H

	#include <linux/errno.h>
	#include <linux/fwnode.h>
	#include <linux/list.h>
	#include <linux/types.h>

	#include <media/v4l2-mediabus.h>
	#include <media/v4l2-subdev.h>

	struct fwnode_handle;
	struct v4l2_async_notifier;
	struct v4l2_async_subdev;

	#define V4L2_FWNODE_CSI2_MAX_DATA_LANES 4

	/**
	* struct v4l2_fwnode_bus_mipi_csi2 - MIPI CSI-2 bus data structure
	* @flags: media bus (V4L2_MBUS_*) flags
	* @data_lanes: an array of physical data lane indexes
	* @clock_lane: physical lane index of the clock lane
	* @num_data_lanes: number of data lanes
	* @lane_polarities: polarity of the lanes. The order is the same of
	* the physical lanes.
	*/
	struct v4l2_fwnode_bus_mipi_csi2 {
	unsigned int flags;
	unsigned char data_lanes[V4L2_FWNODE_CSI2_MAX_DATA_LANES];
	unsigned char clock_lane;
	unsigned short num_data_lanes;
	bool lane_polarities[1 + V4L2_FWNODE_CSI2_MAX_DATA_LANES];
	};

	/**
	* struct v4l2_fwnode_bus_parallel - parallel data bus data structure
	* @flags: media bus (V4L2_MBUS_*) flags
	* @bus_width: bus width in bits
	* @data_shift: data shift in bits
	*/
	struct v4l2_fwnode_bus_parallel {
	unsigned int flags;
	unsigned char bus_width;
	unsigned char data_shift;
	};

	/**
	* struct v4l2_fwnode_bus_mipi_csi1 - CSI-1/CCP2 data bus structure
	* @clock_inv: polarity of clock/strobe signal
	* false - not inverted, true - inverted
	* @strobe: false - data/clock, true - data/strobe
	* @lane_polarity: the polarities of the clock (index 0) and data lanes
	* index (1)
	* @data_lane: the number of the data lane
	* @clock_lane: the number of the clock lane
	*/
	struct v4l2_fwnode_bus_mipi_csi1 {
	unsigned char clock_inv:1;
	unsigned char strobe:1;
	bool lane_polarity[2];
	unsigned char data_lane;
	unsigned char clock_lane;
	};

	/**
	* struct v4l2_fwnode_endpoint - the endpoint data structure
	* @base: fwnode endpoint of the v4l2_fwnode
	* @bus_type: bus type
	* @bus: union with bus configuration data structure
	* @bus.parallel: embedded &struct v4l2_fwnode_bus_parallel.
	* Used if the bus is parallel.
	* @bus.mipi_csi1: embedded &struct v4l2_fwnode_bus_mipi_csi1.
	* Used if the bus is MIPI Alliance's Camera Serial
	* Interface version 1 (MIPI CSI1) or Standard
	* Mobile Imaging Architecture's Compact Camera Port 2
	* (SMIA CCP2).
	* @bus.mipi_csi2: embedded &struct v4l2_fwnode_bus_mipi_csi2.
	* Used if the bus is MIPI Alliance's Camera Serial
	* Interface version 2 (MIPI CSI2).
	* @link_frequencies: array of supported link frequencies
	* @nr_of_link_frequencies: number of elements in link_frequenccies array
	*/
	struct v4l2_fwnode_endpoint {
	struct fwnode_endpoint base;
	/*
	* Fields below this line will be zeroed by
	* v4l2_fwnode_endpoint_parse()
	*/
	enum v4l2_mbus_type bus_type;
	union {
	struct v4l2_fwnode_bus_parallel parallel;
	struct v4l2_fwnode_bus_mipi_csi1 mipi_csi1;
	struct v4l2_fwnode_bus_mipi_csi2 mipi_csi2;
	} bus;
	u64 *link_frequencies;
	unsigned int nr_of_link_frequencies;
	};

	/**
	* struct v4l2_fwnode_link - a link between two endpoints
	* @local_node: pointer to device_node of this endpoint
	* @local_port: identifier of the port this endpoint belongs to
	* @remote_node: pointer to device_node of the remote endpoint
	* @remote_port: identifier of the port the remote endpoint belongs to
	*/
	struct v4l2_fwnode_link {
	struct fwnode_handle *local_node;
	unsigned int local_port;
	struct fwnode_handle *remote_node;
	unsigned int remote_port;
	};

	/**
	* v4l2_fwnode_endpoint_parse() - parse all fwnode node properties
	* @fwnode: pointer to the endpoint's fwnode handle
	* @vep: pointer to the V4L2 fwnode data structure
	*
	* This function parses the V4L2 fwnode endpoint specific parameters from the
	* firmware. The caller is responsible for assigning @vep.bus_type to a valid
	* media bus type. The caller may also set the default configuration for the
	* endpoint --- a configuration that shall be in line with the DT binding
	* documentation. Should a device support multiple bus types, the caller may
	* call this function once the correct type is found --- with a default
	* configuration valid for that type.
	*
	* As a compatibility means guessing the bus type is also supported by setting
	* @vep.bus_type to V4L2_MBUS_UNKNOWN. The caller may not provide a default
	* configuration in this case as the defaults are specific to a given bus type.
	* This functionality is deprecated and should not be used in new drivers and it
	* is only supported for CSI-2 D-PHY, parallel and Bt.656 buses.
	*
	* The function does not change the V4L2 fwnode endpoint state if it fails.
	*
	* NOTE: This function does not parse properties the size of which is variable
	* without a low fixed limit. Please use v4l2_fwnode_endpoint_alloc_parse() in
	* new drivers instead.
	*
	* Return: %0 on success or a negative error code on failure:
	* %-ENOMEM on memory allocation failure
	* %-EINVAL on parsing failure
	* %-ENXIO on mismatching bus types
	*/
	int v4l2_fwnode_endpoint_parse(struct fwnode_handle *fwnode,
	struct v4l2_fwnode_endpoint *vep);

	/**
	* v4l2_fwnode_endpoint_free() - free the V4L2 fwnode acquired by
	* v4l2_fwnode_endpoint_alloc_parse()
	* @vep: the V4L2 fwnode the resources of which are to be released
	*
	* It is safe to call this function with NULL argument or on a V4L2 fwnode the
	* parsing of which failed.
	*/
	void v4l2_fwnode_endpoint_free(struct v4l2_fwnode_endpoint *vep);

	/**
	* v4l2_fwnode_endpoint_alloc_parse() - parse all fwnode node properties
	* @fwnode: pointer to the endpoint's fwnode handle
	* @vep: pointer to the V4L2 fwnode data structure
	*
	* This function parses the V4L2 fwnode endpoint specific parameters from the
	* firmware. The caller is responsible for assigning @vep.bus_type to a valid
	* media bus type. The caller may also set the default configuration for the
	* endpoint --- a configuration that shall be in line with the DT binding
	* documentation. Should a device support multiple bus types, the caller may
	* call this function once the correct type is found --- with a default
	* configuration valid for that type.
	*
	* As a compatibility means guessing the bus type is also supported by setting
	* @vep.bus_type to V4L2_MBUS_UNKNOWN. The caller may not provide a default
	* configuration in this case as the defaults are specific to a given bus type.
	* This functionality is deprecated and should not be used in new drivers and it
	* is only supported for CSI-2 D-PHY, parallel and Bt.656 buses.
	*
	* The function does not change the V4L2 fwnode endpoint state if it fails.
	*
	* v4l2_fwnode_endpoint_alloc_parse() has two important differences to
	* v4l2_fwnode_endpoint_parse():
	*
	* 1. It also parses variable size data.
	*
	* 2. The memory it has allocated to store the variable size data must be freed
	* using v4l2_fwnode_endpoint_free() when no longer needed.
	*
	* Return: %0 on success or a negative error code on failure:
	* %-ENOMEM on memory allocation failure
	* %-EINVAL on parsing failure
	* %-ENXIO on mismatching bus types
	*/
	int v4l2_fwnode_endpoint_alloc_parse(struct fwnode_handle *fwnode,
	struct v4l2_fwnode_endpoint *vep);

	/**
	* v4l2_fwnode_parse_link() - parse a link between two endpoints
	* @fwnode: pointer to the endpoint's fwnode at the local end of the link
	* @link: pointer to the V4L2 fwnode link data structure
	*
	* Fill the link structure with the local and remote nodes and port numbers.
	* The local_node and remote_node fields are set to point to the local and
	* remote port's parent nodes respectively (the port parent node being the
	* parent node of the port node if that node isn't a 'ports' node, or the
	* grand-parent node of the port node otherwise).
	*
	* A reference is taken to both the local and remote nodes, the caller must use
	* v4l2_fwnode_put_link() to drop the references when done with the
	* link.
	*
	* Return: 0 on success, or -ENOLINK if the remote endpoint fwnode can't be
	* found.
	*/
	int v4l2_fwnode_parse_link(struct fwnode_handle *fwnode,
	struct v4l2_fwnode_link *link);

	/**
	* v4l2_fwnode_put_link() - drop references to nodes in a link
	* @link: pointer to the V4L2 fwnode link data structure
	*
	* Drop references to the local and remote nodes in the link. This function
	* must be called on every link parsed with v4l2_fwnode_parse_link().
	*/
	void v4l2_fwnode_put_link(struct v4l2_fwnode_link *link);

	/**
	* typedef parse_endpoint_func - Driver's callback function to be called on
	* each V4L2 fwnode endpoint.
	*
	* @dev: pointer to &struct device
	* @vep: pointer to &struct v4l2_fwnode_endpoint
	* @asd: pointer to &struct v4l2_async_subdev
	*
	* Return:
	* * %0 on success
	* * %-ENOTCONN if the endpoint is to be skipped but this
	* should not be considered as an error
	* * %-EINVAL if the endpoint configuration is invalid
	*/
	typedef int (parse_endpoint_func)(struct device dev,
	struct v4l2_fwnode_endpoint *vep,
	struct v4l2_async_subdev *asd);

	/**
	* v4l2_async_notifier_parse_fwnode_endpoints - Parse V4L2 fwnode endpoints in a
	* device node
	* @dev: the device the endpoints of which are to be parsed
	* @notifier: notifier for @dev
	* @asd_struct_size: size of the driver's async sub-device struct, including
	* sizeof(struct v4l2_async_subdev). The &struct
	* v4l2_async_subdev shall be the first member of
	* the driver's async sub-device struct, i.e. both
	* begin at the same memory address.
	* @parse_endpoint: Driver's callback function called on each V4L2 fwnode
	* endpoint. Optional.
	*
	* Parse the fwnode endpoints of the @dev device and populate the async sub-
	* devices list in the notifier. The @parse_endpoint callback function is
	* called for each endpoint with the corresponding async sub-device pointer to
	* let the caller initialize the driver-specific part of the async sub-device
	* structure.
	*
	* The notifier memory shall be zeroed before this function is called on the
	* notifier.
	*
	* This function may not be called on a registered notifier and may be called on
	* a notifier only once.
	*
	* The &struct v4l2_fwnode_endpoint passed to the callback function
	* @parse_endpoint is released once the function is finished. If there is a need
	* to retain that configuration, the user needs to allocate memory for it.
	*
	* Any notifier populated using this function must be released with a call to
	* v4l2_async_notifier_cleanup() after it has been unregistered and the async
	* sub-devices are no longer in use, even if the function returned an error.
	*
	* Return: %0 on success, including when no async sub-devices are found
	* %-ENOMEM if memory allocation failed
	* %-EINVAL if graph or endpoint parsing failed
	* Other error codes as returned by @parse_endpoint
	*/
	int
	v4l2_async_notifier_parse_fwnode_endpoints(struct device *dev,
	struct v4l2_async_notifier *notifier,
	size_t asd_struct_size,
	parse_endpoint_func parse_endpoint);

	/**
	* v4l2_async_notifier_parse_fwnode_endpoints_by_port - Parse V4L2 fwnode
	* endpoints of a port in a
	* device node
	* @dev: the device the endpoints of which are to be parsed
	* @notifier: notifier for @dev
	* @asd_struct_size: size of the driver's async sub-device struct, including
	* sizeof(struct v4l2_async_subdev). The &struct
	* v4l2_async_subdev shall be the first member of
	* the driver's async sub-device struct, i.e. both
	* begin at the same memory address.
	* @port: port number where endpoints are to be parsed
	* @parse_endpoint: Driver's callback function called on each V4L2 fwnode
	* endpoint. Optional.
	*
	* This function is just like v4l2_async_notifier_parse_fwnode_endpoints() with
	* the exception that it only parses endpoints in a given port. This is useful
	* on devices that have both sinks and sources: the async sub-devices connected
	* to sources have already been configured by another driver (on capture
	* devices). In this case the driver must know which ports to parse.
	*
	* Parse the fwnode endpoints of the @dev device on a given @port and populate
	* the async sub-devices list of the notifier. The @parse_endpoint callback
	* function is called for each endpoint with the corresponding async sub-device
	* pointer to let the caller initialize the driver-specific part of the async
	* sub-device structure.
	*
	* The notifier memory shall be zeroed before this function is called on the
	* notifier the first time.
	*
	* This function may not be called on a registered notifier and may be called on
	* a notifier only once per port.
	*
	* The &struct v4l2_fwnode_endpoint passed to the callback function
	* @parse_endpoint is released once the function is finished. If there is a need
	* to retain that configuration, the user needs to allocate memory for it.
	*
	* Any notifier populated using this function must be released with a call to
	* v4l2_async_notifier_cleanup() after it has been unregistered and the async
	* sub-devices are no longer in use, even if the function returned an error.
	*
	* Return: %0 on success, including when no async sub-devices are found
	* %-ENOMEM if memory allocation failed
	* %-EINVAL if graph or endpoint parsing failed
	* Other error codes as returned by @parse_endpoint
	*/
	int
	v4l2_async_notifier_parse_fwnode_endpoints_by_port(struct device *dev,
	struct v4l2_async_notifier *notifier,
	size_t asd_struct_size,
	unsigned int port,
	parse_endpoint_func parse_endpoint);

	/**
	* v4l2_fwnode_reference_parse_sensor_common - parse common references on
	* sensors for async sub-devices
	* @dev: the device node the properties of which are parsed for references
	* @notifier: the async notifier where the async subdevs will be added
	*
	* Parse common sensor properties for remote devices related to the
	* sensor and set up async sub-devices for them.
	*
	* Any notifier populated using this function must be released with a call to
	* v4l2_async_notifier_release() after it has been unregistered and the async
	* sub-devices are no longer in use, even in the case the function returned an
	* error.
	*
	* Return: 0 on success
	* -ENOMEM if memory allocation failed
	* -EINVAL if property parsing failed
	*/
	int v4l2_async_notifier_parse_fwnode_sensor_common(struct device *dev,
	struct v4l2_async_notifier *notifier);

	/**
	* v4l2_async_register_fwnode_subdev - registers a sub-device to the
	* asynchronous sub-device framework
	* and parses fwnode endpoints
	*
	* @sd: pointer to struct &v4l2_subdev
	* @asd_struct_size: size of the driver's async sub-device struct, including
	* sizeof(struct v4l2_async_subdev). The &struct
	* v4l2_async_subdev shall be the first member of
	* the driver's async sub-device struct, i.e. both
	* begin at the same memory address.
	* @ports: array of port id's to parse for fwnode endpoints. If NULL, will
	* parse all ports owned by the sub-device.
	* @num_ports: number of ports in @ports array. Ignored if @ports is NULL.
	* @parse_endpoint: Driver's callback function called on each V4L2 fwnode
	* endpoint. Optional.
	*
	* This function is just like v4l2_async_register_subdev() with the
	* exception that calling it will also allocate a notifier for the
	* sub-device, parse the sub-device's firmware node endpoints using
	* v4l2_async_notifier_parse_fwnode_endpoints() or
	* v4l2_async_notifier_parse_fwnode_endpoints_by_port(), and
	* registers the sub-device notifier. The sub-device is similarly
	* unregistered by calling v4l2_async_unregister_subdev().
	*
	* While registered, the subdev module is marked as in-use.
	*
	* An error is returned if the module is no longer loaded on any attempts
	* to register it.
	*/
	int
	v4l2_async_register_fwnode_subdev(struct v4l2_subdev *sd,
	size_t asd_struct_size,
	unsigned int *ports,
	unsigned int num_ports,
	parse_endpoint_func parse_endpoint);

	#endif /* _V4L2_FWNODE_H */