u-boot/include/dm/of.h

/*
 * Copyright (c) 2017 Google, Inc
 * Written by Simon Glass <sjg@chromium.org>
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#ifndef _DM_OF_H
#define _DM_OF_H

#include <asm/u-boot.h>
#include <asm/global_data.h>

/* integer value within a device tree property which references another node */
typedef u32 phandle;

/**
 * struct property: Device tree property
 *
 * @name: Property name
 * @length: Length of property in bytes
 * @value: Pointer to property value
 * @next: Pointer to next property, or NULL if none
 */
struct property {
	char *name;
	int length;
	void *value;
	struct property *next;
};

/**
 * struct device_node: Device tree node
 *
 * @name: Node name
 * @type: Node type (value of device_type property) or "<NULL>" if none
 * @phandle: Phandle value of this none, or 0 if none
 * @full_name: Full path to node, e.g. "/bus@1/spi@1100"
 * @properties: Pointer to head of list of properties, or NULL if none
 * @parent: Pointer to parent node, or NULL if this is the root node
 * @child: Pointer to head of child node list, or NULL if no children
 * @sibling: Pointer to the next sibling node, or NULL if this is the last
 */
struct device_node {
	const char *name;
	const char *type;
	phandle phandle;
	const char *full_name;

	struct property *properties;
	struct device_node *parent;
	struct device_node *child;
	struct device_node *sibling;
};

#define OF_MAX_PHANDLE_ARGS 16

/**
 * struct of_phandle_args - structure to hold phandle and arguments
 *
 * This is used when decoding a phandle in a device tree property. Typically
 * these look like this:
 *
 * wibble {
 *    phandle = <5>;
 * };
 *
 * ...
 * some-prop = <&wibble 1 2 3>
 *
 * Here &node is the phandle of the node 'wibble', i.e. 5. There are three
 * arguments: 1, 2, 3.
 *
 * So when decoding the phandle in some-prop, np will point to wibble,
 * args_count will be 3 and the three arguments will be in args.
 *
 * @np: Node that the phandle refers to
 * @args_count: Number of arguments
 * @args: Argument values
 */
struct of_phandle_args {
	struct device_node *np;
	int args_count;
	uint32_t args[OF_MAX_PHANDLE_ARGS];
};

DECLARE_GLOBAL_DATA_PTR;

/**
 * of_live_active() - check if livetree is active
 *
 * @returns true if livetree is active, false it not
 */
#ifdef CONFIG_OF_LIVE
static inline bool of_live_active(void)
{
	return gd->of_root != NULL;
}
#else
static inline bool of_live_active(void)
{
	return false;
}
#endif

#endif