pdt.c

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/* pdt.c: OF PROM device tree support code.
 *
 * Paul Mackerras   August 1996.
 * Copyright (C) 1996-2005 Paul Mackerras.
 *
 *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
 *    {engebret|bergner}@us.ibm.com
 *
 *  Adapted for sparc by David S. Miller [email protected]
 *  Adapted for multiple architectures by Andres Salomon <[email protected]>
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_pdt.h>
#include <asm/prom.h>

static struct of_pdt_ops *of_pdt_prom_ops __initdata;

void __initdata (*of_pdt_build_more)(struct device_node *dp,
        struct device_node ***nextp);

#if defined(CONFIG_SPARC)
unsigned int of_pdt_unique_id __initdata;

#define of_pdt_incr_unique_id(p) do { \
    (p)->unique_id = of_pdt_unique_id++; \
} while (0)

static char * __init of_pdt_build_full_name(struct device_node *dp)
{
    int len, ourlen, plen;
    char *n;

    dp->path_component_name = build_path_component(dp);

    plen = strlen(dp->parent->full_name);
    ourlen = strlen(dp->path_component_name);
    len = ourlen + plen + 2;

    n = prom_early_alloc(len);
    strcpy(n, dp->parent->full_name);
    if (!of_node_is_root(dp->parent)) {
        strcpy(n + plen, "/");
        plen++;
    }
    strcpy(n + plen, dp->path_component_name);

    return n;
}

#else /* CONFIG_SPARC */

static inline void of_pdt_incr_unique_id(void *p) { }
static inline void irq_trans_init(struct device_node *dp) { }

static char * __init of_pdt_build_full_name(struct device_node *dp)
{
    static int failsafe_id = 0; /* for generating unique names on failure */
    char *buf;
    int len;

    if (of_pdt_prom_ops->pkg2path(dp->phandle, NULL, 0, &len))
        goto failsafe;

    buf = prom_early_alloc(len + 1);
    if (of_pdt_prom_ops->pkg2path(dp->phandle, buf, len, &len))
        goto failsafe;
    return buf;

 failsafe:
    buf = prom_early_alloc(strlen(dp->parent->full_name) +
                   strlen(dp->name) + 16);
    sprintf(buf, "%s/%s@unknown%i",
        of_node_is_root(dp->parent) ? "" : dp->parent->full_name,
        dp->name, failsafe_id++);
    pr_err("%s: pkg2path failed; assigning %s\n", __func__, buf);
    return buf;
}

#endif /* !CONFIG_SPARC */

static struct property * __init of_pdt_build_one_prop(phandle node, char *prev,
                           char *special_name,
                           void *special_val,
                           int special_len)
{
    static struct property *tmp = NULL;
    struct property *p;
    int err;

    if (tmp) {
        p = tmp;
        memset(p, 0, sizeof(*p) + 32);
        tmp = NULL;
    } else {
        p = prom_early_alloc(sizeof(struct property) + 32);
        of_pdt_incr_unique_id(p);
    }

    p->name = (char *) (p + 1);
    if (special_name) {
        strcpy(p->name, special_name);
        p->length = special_len;
        p->value = prom_early_alloc(special_len);
        memcpy(p->value, special_val, special_len);
    } else {
        err = of_pdt_prom_ops->nextprop(node, prev, p->name);
        if (err) {
            tmp = p;
            return NULL;
        }
        p->length = of_pdt_prom_ops->getproplen(node, p->name);
        if (p->length <= 0) {
            p->length = 0;
        } else {
            int len;

            p->value = prom_early_alloc(p->length + 1);
            len = of_pdt_prom_ops->getproperty(node, p->name,
                    p->value, p->length);
            if (len <= 0)
                p->length = 0;
            ((unsigned char *)p->value)[p->length] = '\0';
        }
    }
    return p;
}

static struct property * __init of_pdt_build_prop_list(phandle node)
{
    struct property *head, *tail;

    head = tail = of_pdt_build_one_prop(node, NULL,
                     ".node", &node, sizeof(node));

    tail->next = of_pdt_build_one_prop(node, NULL, NULL, NULL, 0);
    tail = tail->next;
    while(tail) {
        tail->next = of_pdt_build_one_prop(node, tail->name,
                        NULL, NULL, 0);
        tail = tail->next;
    }

    return head;
}

static char * __init of_pdt_get_one_property(phandle node, const char *name)
{
    char *buf = "<NULL>";
    int len;

    len = of_pdt_prom_ops->getproplen(node, name);
    if (len > 0) {
        buf = prom_early_alloc(len);
        len = of_pdt_prom_ops->getproperty(node, name, buf, len);
    }

    return buf;
}

static struct device_node * __init of_pdt_create_node(phandle node,
                            struct device_node *parent)
{
    struct device_node *dp;

    if (!node)
        return NULL;

    dp = prom_early_alloc(sizeof(*dp));
    of_pdt_incr_unique_id(dp);
    dp->parent = parent;

    kref_init(&dp->kref);

    dp->name = of_pdt_get_one_property(node, "name");
    dp->type = of_pdt_get_one_property(node, "device_type");
    dp->phandle = node;

    dp->properties = of_pdt_build_prop_list(node);

    irq_trans_init(dp);

    return dp;
}

static struct device_node * __init of_pdt_build_tree(struct device_node *parent,
                           phandle node,
                           struct device_node ***nextp)
{
    struct device_node *ret = NULL, *prev_sibling = NULL;
    struct device_node *dp;

    while (1) {
        dp = of_pdt_create_node(node, parent);
        if (!dp)
            break;

        if (prev_sibling)
            prev_sibling->sibling = dp;

        if (!ret)
            ret = dp;
        prev_sibling = dp;

        *(*nextp) = dp;
        *nextp = &dp->allnext;

        dp->full_name = of_pdt_build_full_name(dp);

        dp->child = of_pdt_build_tree(dp,
                of_pdt_prom_ops->getchild(node), nextp);

        if (of_pdt_build_more)
            of_pdt_build_more(dp, nextp);

        node = of_pdt_prom_ops->getsibling(node);
    }

    return ret;
}

static void * __init kernel_tree_alloc(u64 size, u64 align)
{
    return prom_early_alloc(size);
}

void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops)
{
    struct device_node **nextp;

    BUG_ON(!ops);
    of_pdt_prom_ops = ops;

    allnodes = of_pdt_create_node(root_node, NULL);
#if defined(CONFIG_SPARC)
    allnodes->path_component_name = "";
#endif
    allnodes->full_name = "/";

    nextp = &allnodes->allnext;
    allnodes->child = of_pdt_build_tree(allnodes,
            of_pdt_prom_ops->getchild(allnodes->phandle), &nextp);

    /* Get pointer to "/chosen" and "/aliasas" nodes for use everywhere */
    of_alias_scan(kernel_tree_alloc);
}