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/*

 * 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.

 */

#include <ofw_tree.h>

#include <ofw.h>

#include <types.h>

#include <string.h>

#include <balloc.h>

#include <asm.h>

#define MAX_PATH_LEN	256

static ofw_tree_node_t *ofw_tree_node_alloc(void)

{

	return balloc(sizeof(ofw_tree_node_t), sizeof(ofw_tree_node_t));

}

static ofw_tree_property_t *ofw_tree_properties_alloc(unsigned count)

{

	return balloc(count * sizeof(ofw_tree_property_t), sizeof(ofw_tree_property_t));

}

static void * ofw_tree_space_alloc(size_t size)

{

	char *addr;

	/*

	 * What we do here is a nasty hack :-)

	 * Problem: string property values that are allocated via this

	 * function typically do not contain the trailing '\0'. This

	 * is very uncomfortable for kernel, which is supposed to deal

	 * with the properties.

	 * Solution: when allocating space via this function, we always

	 * allocate space for the extra '\0' character that we store

	 * behind the requested memory.

	 */

	addr = balloc(size + 1, size);

	if (addr)

		addr[size] = '\0';

	return addr;

}

/** Transfer information from one OpenFirmware node into its memory representation.

 *

 * Transfer entire information from the OpenFirmware device tree 'current' node to

 * its memory representation in 'current_node'. This function recursively processes

 * all node's children. Node's peers are processed iteratively in order to prevent

 * stack from overflowing.

 *

 * @param current_node	Pointer to uninitialized ofw_tree_node structure that will

 * 			become the memory represenation of 'current'.

 * @param parent_node	Parent ofw_tree_node structure or NULL in case of root node.

 * @param current	OpenFirmware phandle to the current device tree node.

 */

static void ofw_tree_node_process(ofw_tree_node_t *current_node,

	ofw_tree_node_t *parent_node, phandle current)

{

	static char path[MAX_PATH_LEN+1];

	static char name[OFW_TREE_PROPERTY_MAX_NAMELEN];

	static char name2[OFW_TREE_PROPERTY_MAX_NAMELEN];

	phandle peer;

	phandle child;

	size_t len;

	int i;

	while (current_node) {

		/*

		 * Initialize node.

		 */

		current_node->parent = parent_node;

		current_node->peer = NULL;

		current_node->child = NULL;

		current_node->node_handle = current;

		current_node->properties = 0;

		current_node->property = NULL;

		current_node->device = NULL;

		/*

		 * Get the disambigued name.

		 */

		len = ofw_package_to_path(current, path, MAX_PATH_LEN);

		if (len == -1)

			return;

		path[len] = '\0';

		for (i = len - 1; i >= 0 && path[i] != '/'; i--)

			;

		i++;	/* do not include '/' */

		len -= i;

		/* add space for trailing '\0' */

		current_node->da_name = ofw_tree_space_alloc(len + 1);

		if (!current_node->da_name)

			return;

		memcpy(current_node->da_name, &path[i], len);

		current_node->da_name[len] = '\0';

		/*

		 * Recursively process the potential child node.

		 */

		child = ofw_get_child_node(current);

		if (child != 0 && child != -1) {

			ofw_tree_node_t *child_node;

			child_node = ofw_tree_node_alloc();

			if (child_node) {

				ofw_tree_node_process(child_node, current_node, child);

				current_node->child = child_node;

			}

		}

		/*

		 * Count properties.

		 */

		name[0] = '\0';

		while (ofw_next_property(current, name, name2) == 1) {

			current_node->properties++;

			memcpy(name, name2, OFW_TREE_PROPERTY_MAX_NAMELEN);

		}

		if (!current_node->properties)

			return;

		/*

		 * Copy properties.

		 */

		current_node->property = ofw_tree_properties_alloc(current_node->properties);

		if (!current_node->property)

			return;

		name[0] = '\0';

		for (i = 0; ofw_next_property(current, name, name2) == 1; i++) {

			size_t size;

			if (i == current_node->properties)

				break;

			memcpy(name, name2, OFW_TREE_PROPERTY_MAX_NAMELEN);

			memcpy(current_node->property[i].name, name,

				OFW_TREE_PROPERTY_MAX_NAMELEN);

			current_node->property[i].name[OFW_TREE_PROPERTY_MAX_NAMELEN] = '\0';

			size = ofw_get_proplen(current, name);

			current_node->property[i].size = size;

			if (size) {

				void *buf;

				buf = ofw_tree_space_alloc(size);

				if (current_node->property[i].value = buf) {

					/*

					 * Copy property value to memory node.

					 */

					(void) ofw_get_property(current, name, buf, size);

				}

			} else {

				current_node->property[i].value = NULL;

			}

		}

		current_node->properties = i;	/* Just in case we ran out of memory. */

		/*

		 * Iteratively process the next peer node.

		 * Note that recursion is a bad idea here.

		 * Due to the topology of the OpenFirmware device tree,

		 * the nesting of peer nodes could be to wide and the

		 * risk of overflowing the stack is too real.

		 */

		peer = ofw_get_peer_node(current);

		if (peer != 0 && peer != -1) {

			ofw_tree_node_t *peer_node;

			peer_node = ofw_tree_node_alloc();

			if (peer_node) { 

				current_node->peer = peer_node;

				current_node = peer_node;

				current = peer;

				/*

				 * Process the peer in next iteration.

				 */

				continue;

			}

		}

		/*

		 * No more peers on this level.

		 */

		break;

	}

}

/** Construct memory representation of OpenFirmware device tree.

 *

 * @return NULL on failure or pointer to the root node.

 */

ofw_tree_node_t *ofw_tree_build(void)

{

	ofw_tree_node_t *root;

	phandle ssm_node;

	ofw_tree_node_t *ssm;

	root = ofw_tree_node_alloc();

	if (root)

		ofw_tree_node_process(root, NULL, ofw_root);

	/*

	 * The firmware client interface does not automatically include the

	 * "ssm" node in the list of children of "/". A nasty yet working

	 * solution is to explicitly stick "ssm" to the OFW tree.

	 */

	ssm_node = ofw_find_device("/ssm@0,0");

	if (ssm_node != -1) {

		ssm = ofw_tree_node_alloc();

		if (ssm) {

			ofw_tree_node_process(

				ssm, root, ofw_find_device("/ssm@0,0"));

			ssm->peer = root->child;

			root->child = ssm;

		}

	}

	return root;

}