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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 peers and children.
 *
 * @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];
    phandle peer;
    phandle child;
    unsigned properties = 0;
    size_t len;
    int i;

    /*
     * Initialize node.
     */
    current_node->parent = parent_node;
    current_node->peer = NULL;
    current_node->child = NULL;
    current_node->properties = 0;
    current_node->property = 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;
    current_node->da_name = ofw_tree_space_alloc(len + 1);      /* add space for trailing '\0' */
    if (!current_node->da_name)
        return;
    
    memcpy(current_node->da_name, &path[i], len);
    current_node->da_name[len] = '\0';
    
    /*
     * Recursively process the potential peer node.
     */
    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) {
            ofw_tree_node_process(peer_node, parent_node, peer);
            current_node->peer = peer_node;
        }
    }
    
    /*
     * 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, name) == 1)
        current_node->properties++;
    
    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, name) == 1; i++) {
        size_t size;
        
        if (i == current_node->properties)
            break;
        
        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. */
}

/** 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;
    
    root = ofw_tree_node_alloc();
    if (root)
        ofw_tree_node_process(root, NULL, ofw_root);
    
    return root;
}