/*
 * Copyright (c) 2006 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup ofw
 * @{
 */
/**
 * @file
 * @brief	OpenFirmware device tree navigation.
 *
 */

#include <genarch/ofw/ofw_tree.h>
#include <arch/memstr.h>
#include <mm/slab.h>
#include <string.h>
#include <print.h>
#include <panic.h>

#define PATH_MAX_LEN	80
#define NAME_BUF_LEN	50

static ofw_tree_node_t *ofw_root;

void ofw_tree_init(ofw_tree_node_t *root)
{
	ofw_root = root;
}

/** Get OpenFirmware node property.
 *
 * @param node		Node in which to lookup the property.
 * @param name		Name of the property.
 *
 * @return		Pointer to the property structure or NULL if no such
 * 			property.
 */
ofw_tree_property_t *
ofw_tree_getprop(const ofw_tree_node_t *node, const char *name)
{
	unsigned int i;
	
	for (i = 0; i < node->properties; i++) {
		if (str_cmp(node->property[i].name, name) == 0)
			return &node->property[i];
	}

	return NULL;
}

/** Return value of the 'name' property.
 *
 * @param node		Node of interest.
 *
 * @return		Value of the 'name' property belonging to the node.
 */
const char *ofw_tree_node_name(const ofw_tree_node_t *node)
{
	ofw_tree_property_t *prop;
	
	prop = ofw_tree_getprop(node, "name");
	if (!prop)
		panic("Node without name property.");
		
	if (prop->size < 2)
		panic("Invalid name property.");
	
	return prop->value;
}

/** Lookup child of given name.
 *
 * @param node		Node whose child is being looked up.
 * @param name		Name of the child being looked up.
 *
 * @return		NULL if there is no such child or pointer to the
 * 			matching child node.
 */
ofw_tree_node_t *ofw_tree_find_child(ofw_tree_node_t *node, const char *name)
{
	ofw_tree_node_t *cur;
	
	/*
	 * Try to find the disambigued name.
	 */
	for (cur = node->child; cur; cur = cur->peer) {
		if (str_cmp(cur->da_name, name) == 0)
			return cur;
	}
	
	/*
	 * Disambigued name not found.
	 * Lets try our luck with possibly ambiguous "name" property.
	 *
	 * We need to do this because paths stored in "/aliases"
	 * are not always fully-qualified.
	 */
	for (cur = node->child; cur; cur = cur->peer) {
		if (str_cmp(ofw_tree_node_name(cur), name) == 0)
			return cur;
	}
		
	return NULL;
}

/** Lookup first child of given device type.
 *
 * @param node		Node whose child is being looked up.
 * @param name		Device type of the child being looked up.
 *
 * @return		NULL if there is no such child or pointer to the
 * 			matching child node.
 */
ofw_tree_node_t *
ofw_tree_find_child_by_device_type(ofw_tree_node_t *node, const char *name)
{
	ofw_tree_node_t *cur;
	ofw_tree_property_t *prop;
	
	for (cur = node->child; cur; cur = cur->peer) {
		prop = ofw_tree_getprop(cur, "device_type");
		if (!prop || !prop->value)
			continue;
		if (str_cmp(prop->value, name) == 0)
			return cur;
	}
			
	return NULL;
}

/** Lookup node with matching node_handle.
 *
 * Child nodes are looked up recursively contrary to peer nodes that
 * are looked up iteratively to avoid stack overflow.
 *
 * @param root		Root of the searched subtree.
 * @param handle	OpenFirmware handle.
 *
 * @return		NULL if there is no such node or pointer to the matching
 * 			node.
 */
ofw_tree_node_t *
ofw_tree_find_node_by_handle(ofw_tree_node_t *root, uint32_t handle)
{
	ofw_tree_node_t *cur;

	for (cur = root; cur; cur = cur->peer) {		
		if (cur->node_handle == handle)
			return cur;

		if (cur->child) {
			ofw_tree_node_t *node;
			
			node = ofw_tree_find_node_by_handle(cur->child, handle);
			if (node)
				return node;
		}
	}
	
	return NULL;	
}

/** Lookup first peer of given device type.
 *
 * @param node		Node whose peer is being looked up.
 * @param name		Device type of the child being looked up.
 *
 * @return		NULL if there is no such child or pointer to the
 * 			matching child node.
 */
ofw_tree_node_t *
ofw_tree_find_peer_by_device_type(ofw_tree_node_t *node, const char *name)
{
	ofw_tree_node_t *cur;
	ofw_tree_property_t *prop;
	
	for (cur = node->peer; cur; cur = cur->peer) {
		prop = ofw_tree_getprop(cur, "device_type");
		if (!prop || !prop->value)
			continue;
		if (str_cmp(prop->value, name) == 0)
			return cur;
	}
			
	return NULL;
}


/** Lookup first peer of given name.
 *
 * @param node		Node whose peer is being looked up.
 * @param name		Name of the child being looked up.
 *
 * @return		NULL if there is no such peer or pointer to the matching
 * 			peer node.
 */
ofw_tree_node_t *
ofw_tree_find_peer_by_name(ofw_tree_node_t *node, const char *name)
{
	ofw_tree_node_t *cur;
	ofw_tree_property_t *prop;
	
	for (cur = node->peer; cur; cur = cur->peer) {
		prop = ofw_tree_getprop(cur, "name");
		if (!prop || !prop->value)
			continue;
		if (str_cmp(prop->value, name) == 0)
			return cur;
	}
			
	return NULL;
}

/** Lookup OpenFirmware node by its path.
 *
 * @param path		Path to the node.
 *
 * @return		NULL if there is no such node or pointer to the leaf
 * 			node.
 */
ofw_tree_node_t *ofw_tree_lookup(const char *path)
{
	char buf[NAME_BUF_LEN + 1];
	ofw_tree_node_t *node = ofw_root;
	size_t i;
	size_t j;
	
	if (path[0] != '/')
		return NULL;
	
	for (i = 1; (i < str_size(path)) && (node); i = j + 1) {
		for (j = i; (j < str_size(path)) && (path[j] != '/'); j++);
		
		/* Skip extra slashes */
		if (i == j)
			continue;
		
		memcpy(buf, &path[i], j - i);
		buf[j - i] = 0;
		node = ofw_tree_find_child(node, buf);
	}
	
	return node;
}

/** Print OpenFirmware device subtree rooted in a node.
 *
 * Child nodes are processed recursively and peer nodes are processed
 * iteratively in order to avoid stack overflow.
 *
 * @param node		Root of the subtree.
 * @param path		Current path, NULL for the very root of the entire tree.
 */
static void ofw_tree_node_print(const ofw_tree_node_t *node, const char *path)
{
	char *p;
	const ofw_tree_node_t *cur;

	p = (char *) malloc(PATH_MAX_LEN, 0);

	for (cur = node; cur; cur = cur->peer) {
		if (cur->parent) {
			snprintf(p, PATH_MAX_LEN, "%s/%s", path, cur->da_name);
			printf("%s\n", p);
		} else {
			snprintf(p, PATH_MAX_LEN, "%s", cur->da_name);
			printf("/\n");
		}

		if (cur->child)
			ofw_tree_node_print(cur->child, p);
	}

	free(p);
}

/** Print the structure of the OpenFirmware device tree. */
void ofw_tree_print(void)
{
	ofw_tree_node_print(ofw_root, NULL);
}

/** @}
 */