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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.

 */

/** @addtogroup ofw

 * @{

 */

/**

 * @file

 * @brief   OpenFirmware device tree navigation.

 *

 */

#include <genarch/ofw/ofw_tree.h>

#include <arch/memstr.h>

#include <mm/slab.h>

#include <func.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 (strcmp(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.\n");

    if (prop->size < 2)

        panic("Invalid name property.\n");

    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 (strcmp(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 (strcmp(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 (strcmp(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 (strcmp(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;

    index_t i, j;

    if (path[0] != '/')

        return NULL;

    for (i = 1; i < strlen(path) && node; i = j + 1) {

        for (j = i; j < strlen(path) && path[j] != '/'; j++)

            ;

        if (i == j) /* skip extra slashes */

            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);

}

/** @}

 */