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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 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 (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);
}

/** @}
 */