linux/drivers/of/pdt.c
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   1/* pdt.c: OF PROM device tree support code.
   2 *
   3 * Paul Mackerras       August 1996.
   4 * Copyright (C) 1996-2005 Paul Mackerras.
   5 *
   6 *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
   7 *    {engebret|bergner}@us.ibm.com
   8 *
   9 *  Adapted for sparc by David S. Miller davem@davemloft.net
  10 *  Adapted for multiple architectures by Andres Salomon <dilinger@queued.net>
  11 *
  12 *      This program is free software; you can redistribute it and/or
  13 *      modify it under the terms of the GNU General Public License
  14 *      as published by the Free Software Foundation; either version
  15 *      2 of the License, or (at your option) any later version.
  16 */
  17
  18#include <linux/kernel.h>
  19#include <linux/module.h>
  20#include <linux/errno.h>
  21#include <linux/mutex.h>
  22#include <linux/slab.h>
  23#include <linux/of.h>
  24#include <linux/of_pdt.h>
  25
  26static struct of_pdt_ops *of_pdt_prom_ops __initdata;
  27
  28void __initdata (*of_pdt_build_more)(struct device_node *dp);
  29
  30#if defined(CONFIG_SPARC)
  31unsigned int of_pdt_unique_id __initdata;
  32
  33#define of_pdt_incr_unique_id(p) do { \
  34        (p)->unique_id = of_pdt_unique_id++; \
  35} while (0)
  36
  37static char * __init of_pdt_build_full_name(struct device_node *dp)
  38{
  39        int len, ourlen, plen;
  40        char *n;
  41
  42        dp->path_component_name = build_path_component(dp);
  43
  44        plen = strlen(dp->parent->full_name);
  45        ourlen = strlen(dp->path_component_name);
  46        len = ourlen + plen + 2;
  47
  48        n = prom_early_alloc(len);
  49        strcpy(n, dp->parent->full_name);
  50        if (!of_node_is_root(dp->parent)) {
  51                strcpy(n + plen, "/");
  52                plen++;
  53        }
  54        strcpy(n + plen, dp->path_component_name);
  55
  56        return n;
  57}
  58
  59#else /* CONFIG_SPARC */
  60
  61static inline void of_pdt_incr_unique_id(void *p) { }
  62static inline void irq_trans_init(struct device_node *dp) { }
  63
  64static char * __init of_pdt_build_full_name(struct device_node *dp)
  65{
  66        static int failsafe_id = 0; /* for generating unique names on failure */
  67        char *buf;
  68        int len;
  69
  70        if (of_pdt_prom_ops->pkg2path(dp->phandle, NULL, 0, &len))
  71                goto failsafe;
  72
  73        buf = prom_early_alloc(len + 1);
  74        if (of_pdt_prom_ops->pkg2path(dp->phandle, buf, len, &len))
  75                goto failsafe;
  76        return buf;
  77
  78 failsafe:
  79        buf = prom_early_alloc(strlen(dp->parent->full_name) +
  80                               strlen(dp->name) + 16);
  81        sprintf(buf, "%s/%s@unknown%i",
  82                of_node_is_root(dp->parent) ? "" : dp->parent->full_name,
  83                dp->name, failsafe_id++);
  84        pr_err("%s: pkg2path failed; assigning %s\n", __func__, buf);
  85        return buf;
  86}
  87
  88#endif /* !CONFIG_SPARC */
  89
  90static struct property * __init of_pdt_build_one_prop(phandle node, char *prev,
  91                                               char *special_name,
  92                                               void *special_val,
  93                                               int special_len)
  94{
  95        static struct property *tmp = NULL;
  96        struct property *p;
  97        int err;
  98
  99        if (tmp) {
 100                p = tmp;
 101                memset(p, 0, sizeof(*p) + 32);
 102                tmp = NULL;
 103        } else {
 104                p = prom_early_alloc(sizeof(struct property) + 32);
 105                of_pdt_incr_unique_id(p);
 106        }
 107
 108        p->name = (char *) (p + 1);
 109        if (special_name) {
 110                strcpy(p->name, special_name);
 111                p->length = special_len;
 112                p->value = prom_early_alloc(special_len);
 113                memcpy(p->value, special_val, special_len);
 114        } else {
 115                err = of_pdt_prom_ops->nextprop(node, prev, p->name);
 116                if (err) {
 117                        tmp = p;
 118                        return NULL;
 119                }
 120                p->length = of_pdt_prom_ops->getproplen(node, p->name);
 121                if (p->length <= 0) {
 122                        p->length = 0;
 123                } else {
 124                        int len;
 125
 126                        p->value = prom_early_alloc(p->length + 1);
 127                        len = of_pdt_prom_ops->getproperty(node, p->name,
 128                                        p->value, p->length);
 129                        if (len <= 0)
 130                                p->length = 0;
 131                        ((unsigned char *)p->value)[p->length] = '\0';
 132                }
 133        }
 134        return p;
 135}
 136
 137static struct property * __init of_pdt_build_prop_list(phandle node)
 138{
 139        struct property *head, *tail;
 140
 141        head = tail = of_pdt_build_one_prop(node, NULL,
 142                                     ".node", &node, sizeof(node));
 143
 144        tail->next = of_pdt_build_one_prop(node, NULL, NULL, NULL, 0);
 145        tail = tail->next;
 146        while(tail) {
 147                tail->next = of_pdt_build_one_prop(node, tail->name,
 148                                            NULL, NULL, 0);
 149                tail = tail->next;
 150        }
 151
 152        return head;
 153}
 154
 155static char * __init of_pdt_get_one_property(phandle node, const char *name)
 156{
 157        char *buf = "<NULL>";
 158        int len;
 159
 160        len = of_pdt_prom_ops->getproplen(node, name);
 161        if (len > 0) {
 162                buf = prom_early_alloc(len);
 163                len = of_pdt_prom_ops->getproperty(node, name, buf, len);
 164        }
 165
 166        return buf;
 167}
 168
 169static struct device_node * __init of_pdt_create_node(phandle node,
 170                                                    struct device_node *parent)
 171{
 172        struct device_node *dp;
 173
 174        if (!node)
 175                return NULL;
 176
 177        dp = prom_early_alloc(sizeof(*dp));
 178        of_node_init(dp);
 179        of_pdt_incr_unique_id(dp);
 180        dp->parent = parent;
 181
 182        dp->name = of_pdt_get_one_property(node, "name");
 183        dp->type = of_pdt_get_one_property(node, "device_type");
 184        dp->phandle = node;
 185
 186        dp->properties = of_pdt_build_prop_list(node);
 187
 188        irq_trans_init(dp);
 189
 190        return dp;
 191}
 192
 193static struct device_node * __init of_pdt_build_tree(struct device_node *parent,
 194                                                   phandle node)
 195{
 196        struct device_node *ret = NULL, *prev_sibling = NULL;
 197        struct device_node *dp;
 198
 199        while (1) {
 200                dp = of_pdt_create_node(node, parent);
 201                if (!dp)
 202                        break;
 203
 204                if (prev_sibling)
 205                        prev_sibling->sibling = dp;
 206
 207                if (!ret)
 208                        ret = dp;
 209                prev_sibling = dp;
 210
 211                dp->full_name = of_pdt_build_full_name(dp);
 212
 213                dp->child = of_pdt_build_tree(dp, of_pdt_prom_ops->getchild(node));
 214
 215                if (of_pdt_build_more)
 216                        of_pdt_build_more(dp);
 217
 218                node = of_pdt_prom_ops->getsibling(node);
 219        }
 220
 221        return ret;
 222}
 223
 224static void * __init kernel_tree_alloc(u64 size, u64 align)
 225{
 226        return prom_early_alloc(size);
 227}
 228
 229void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops)
 230{
 231        BUG_ON(!ops);
 232        of_pdt_prom_ops = ops;
 233
 234        of_root = of_pdt_create_node(root_node, NULL);
 235#if defined(CONFIG_SPARC)
 236        of_root->path_component_name = "";
 237#endif
 238        of_root->full_name = "/";
 239
 240        of_root->child = of_pdt_build_tree(of_root,
 241                                of_pdt_prom_ops->getchild(of_root->phandle));
 242
 243        /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
 244        of_alias_scan(kernel_tree_alloc);
 245}
 246