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#include <asm/prom.h>
  26
  27static struct of_pdt_ops *of_pdt_prom_ops __initdata;
  28
  29void __initdata (*of_pdt_build_more)(struct device_node *dp,
  30                struct device_node ***nextp);
  31
  32#if defined(CONFIG_SPARC)
  33unsigned int of_pdt_unique_id __initdata;
  34
  35#define of_pdt_incr_unique_id(p) do { \
  36        (p)->unique_id = of_pdt_unique_id++; \
  37} while (0)
  38
  39static char * __init of_pdt_build_full_name(struct device_node *dp)
  40{
  41        int len, ourlen, plen;
  42        char *n;
  43
  44        dp->path_component_name = build_path_component(dp);
  45
  46        plen = strlen(dp->parent->full_name);
  47        ourlen = strlen(dp->path_component_name);
  48        len = ourlen + plen + 2;
  49
  50        n = prom_early_alloc(len);
  51        strcpy(n, dp->parent->full_name);
  52        if (!of_node_is_root(dp->parent)) {
  53                strcpy(n + plen, "/");
  54                plen++;
  55        }
  56        strcpy(n + plen, dp->path_component_name);
  57
  58        return n;
  59}
  60
  61#else /* CONFIG_SPARC */
  62
  63static inline void of_pdt_incr_unique_id(void *p) { }
  64static inline void irq_trans_init(struct device_node *dp) { }
  65
  66static char * __init of_pdt_build_full_name(struct device_node *dp)
  67{
  68        static int failsafe_id = 0; /* for generating unique names on failure */
  69        char *buf;
  70        int len;
  71
  72        if (of_pdt_prom_ops->pkg2path(dp->phandle, NULL, 0, &len))
  73                goto failsafe;
  74
  75        buf = prom_early_alloc(len + 1);
  76        if (of_pdt_prom_ops->pkg2path(dp->phandle, buf, len, &len))
  77                goto failsafe;
  78        return buf;
  79
  80 failsafe:
  81        buf = prom_early_alloc(strlen(dp->parent->full_name) +
  82                               strlen(dp->name) + 16);
  83        sprintf(buf, "%s/%s@unknown%i",
  84                of_node_is_root(dp->parent) ? "" : dp->parent->full_name,
  85                dp->name, failsafe_id++);
  86        pr_err("%s: pkg2path failed; assigning %s\n", __func__, buf);
  87        return buf;
  88}
  89
  90#endif /* !CONFIG_SPARC */
  91
  92static struct property * __init of_pdt_build_one_prop(phandle node, char *prev,
  93                                               char *special_name,
  94                                               void *special_val,
  95                                               int special_len)
  96{
  97        static struct property *tmp = NULL;
  98        struct property *p;
  99        int err;
 100
 101        if (tmp) {
 102                p = tmp;
 103                memset(p, 0, sizeof(*p) + 32);
 104                tmp = NULL;
 105        } else {
 106                p = prom_early_alloc(sizeof(struct property) + 32);
 107                of_pdt_incr_unique_id(p);
 108        }
 109
 110        p->name = (char *) (p + 1);
 111        if (special_name) {
 112                strcpy(p->name, special_name);
 113                p->length = special_len;
 114                p->value = prom_early_alloc(special_len);
 115                memcpy(p->value, special_val, special_len);
 116        } else {
 117                err = of_pdt_prom_ops->nextprop(node, prev, p->name);
 118                if (err) {
 119                        tmp = p;
 120                        return NULL;
 121                }
 122                p->length = of_pdt_prom_ops->getproplen(node, p->name);
 123                if (p->length <= 0) {
 124                        p->length = 0;
 125                } else {
 126                        int len;
 127
 128                        p->value = prom_early_alloc(p->length + 1);
 129                        len = of_pdt_prom_ops->getproperty(node, p->name,
 130                                        p->value, p->length);
 131                        if (len <= 0)
 132                                p->length = 0;
 133                        ((unsigned char *)p->value)[p->length] = '\0';
 134                }
 135        }
 136        return p;
 137}
 138
 139static struct property * __init of_pdt_build_prop_list(phandle node)
 140{
 141        struct property *head, *tail;
 142
 143        head = tail = of_pdt_build_one_prop(node, NULL,
 144                                     ".node", &node, sizeof(node));
 145
 146        tail->next = of_pdt_build_one_prop(node, NULL, NULL, NULL, 0);
 147        tail = tail->next;
 148        while(tail) {
 149                tail->next = of_pdt_build_one_prop(node, tail->name,
 150                                            NULL, NULL, 0);
 151                tail = tail->next;
 152        }
 153
 154        return head;
 155}
 156
 157static char * __init of_pdt_get_one_property(phandle node, const char *name)
 158{
 159        char *buf = "<NULL>";
 160        int len;
 161
 162        len = of_pdt_prom_ops->getproplen(node, name);
 163        if (len > 0) {
 164                buf = prom_early_alloc(len);
 165                len = of_pdt_prom_ops->getproperty(node, name, buf, len);
 166        }
 167
 168        return buf;
 169}
 170
 171static struct device_node * __init of_pdt_create_node(phandle node,
 172                                                    struct device_node *parent)
 173{
 174        struct device_node *dp;
 175
 176        if (!node)
 177                return NULL;
 178
 179        dp = prom_early_alloc(sizeof(*dp));
 180        of_pdt_incr_unique_id(dp);
 181        dp->parent = parent;
 182
 183        kref_init(&dp->kref);
 184
 185        dp->name = of_pdt_get_one_property(node, "name");
 186        dp->type = of_pdt_get_one_property(node, "device_type");
 187        dp->phandle = node;
 188
 189        dp->properties = of_pdt_build_prop_list(node);
 190
 191        irq_trans_init(dp);
 192
 193        return dp;
 194}
 195
 196static struct device_node * __init of_pdt_build_tree(struct device_node *parent,
 197                                                   phandle node,
 198                                                   struct device_node ***nextp)
 199{
 200        struct device_node *ret = NULL, *prev_sibling = NULL;
 201        struct device_node *dp;
 202
 203        while (1) {
 204                dp = of_pdt_create_node(node, parent);
 205                if (!dp)
 206                        break;
 207
 208                if (prev_sibling)
 209                        prev_sibling->sibling = dp;
 210
 211                if (!ret)
 212                        ret = dp;
 213                prev_sibling = dp;
 214
 215                *(*nextp) = dp;
 216                *nextp = &dp->allnext;
 217
 218                dp->full_name = of_pdt_build_full_name(dp);
 219
 220                dp->child = of_pdt_build_tree(dp,
 221                                of_pdt_prom_ops->getchild(node), nextp);
 222
 223                if (of_pdt_build_more)
 224                        of_pdt_build_more(dp, nextp);
 225
 226                node = of_pdt_prom_ops->getsibling(node);
 227        }
 228
 229        return ret;
 230}
 231
 232static void * __init kernel_tree_alloc(u64 size, u64 align)
 233{
 234        return prom_early_alloc(size);
 235}
 236
 237void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops)
 238{
 239        struct device_node **nextp;
 240
 241        BUG_ON(!ops);
 242        of_pdt_prom_ops = ops;
 243
 244        allnodes = of_pdt_create_node(root_node, NULL);
 245#if defined(CONFIG_SPARC)
 246        allnodes->path_component_name = "";
 247#endif
 248        allnodes->full_name = "/";
 249
 250        nextp = &allnodes->allnext;
 251        allnodes->child = of_pdt_build_tree(allnodes,
 252                        of_pdt_prom_ops->getchild(allnodes->phandle), &nextp);
 253
 254        /* Get pointer to "/chosen" and "/aliasas" nodes for use everywhere */
 255        of_alias_scan(kernel_tree_alloc);
 256}
 257
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