linux/drivers/of/pdt.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2/* pdt.c: OF PROM device tree support code.
   3 *
   4 * Paul Mackerras       August 1996.
   5 * Copyright (C) 1996-2005 Paul Mackerras.
   6 *
   7 *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
   8 *    {engebret|bergner}@us.ibm.com
   9 *
  10 *  Adapted for sparc by David S. Miller davem@davemloft.net
  11 *  Adapted for multiple architectures by Andres Salomon <dilinger@queued.net>
  12 */
  13
  14#include <linux/kernel.h>
  15#include <linux/module.h>
  16#include <linux/errno.h>
  17#include <linux/mutex.h>
  18#include <linux/slab.h>
  19#include <linux/of.h>
  20#include <linux/of_pdt.h>
  21
  22static struct of_pdt_ops *of_pdt_prom_ops __initdata;
  23
  24void __initdata (*of_pdt_build_more)(struct device_node *dp);
  25
  26#if defined(CONFIG_SPARC)
  27unsigned int of_pdt_unique_id __initdata;
  28
  29#define of_pdt_incr_unique_id(p) do { \
  30        (p)->unique_id = of_pdt_unique_id++; \
  31} while (0)
  32
  33static char * __init of_pdt_build_full_name(struct device_node *dp)
  34{
  35        int len, ourlen, plen;
  36        char *n;
  37
  38        dp->path_component_name = build_path_component(dp);
  39
  40        plen = strlen(dp->parent->full_name);
  41        ourlen = strlen(dp->path_component_name);
  42        len = ourlen + plen + 2;
  43
  44        n = prom_early_alloc(len);
  45        strcpy(n, dp->parent->full_name);
  46        if (!of_node_is_root(dp->parent)) {
  47                strcpy(n + plen, "/");
  48                plen++;
  49        }
  50        strcpy(n + plen, dp->path_component_name);
  51
  52        return n;
  53}
  54
  55#else /* CONFIG_SPARC */
  56
  57static inline void of_pdt_incr_unique_id(void *p) { }
  58static inline void irq_trans_init(struct device_node *dp) { }
  59
  60static char * __init of_pdt_build_full_name(struct device_node *dp)
  61{
  62        static int failsafe_id = 0; /* for generating unique names on failure */
  63        char *buf;
  64        int len;
  65
  66        if (of_pdt_prom_ops->pkg2path(dp->phandle, NULL, 0, &len))
  67                goto failsafe;
  68
  69        buf = prom_early_alloc(len + 1);
  70        if (of_pdt_prom_ops->pkg2path(dp->phandle, buf, len, &len))
  71                goto failsafe;
  72        return buf;
  73
  74 failsafe:
  75        buf = prom_early_alloc(strlen(dp->parent->full_name) +
  76                               strlen(dp->name) + 16);
  77        sprintf(buf, "%s/%s@unknown%i",
  78                of_node_is_root(dp->parent) ? "" : dp->parent->full_name,
  79                dp->name, failsafe_id++);
  80        pr_err("%s: pkg2path failed; assigning %s\n", __func__, buf);
  81        return buf;
  82}
  83
  84#endif /* !CONFIG_SPARC */
  85
  86static struct property * __init of_pdt_build_one_prop(phandle node, char *prev,
  87                                               char *special_name,
  88                                               void *special_val,
  89                                               int special_len)
  90{
  91        static struct property *tmp = NULL;
  92        struct property *p;
  93        int err;
  94
  95        if (tmp) {
  96                p = tmp;
  97                memset(p, 0, sizeof(*p) + 32);
  98                tmp = NULL;
  99        } else {
 100                p = prom_early_alloc(sizeof(struct property) + 32);
 101                of_pdt_incr_unique_id(p);
 102        }
 103
 104        p->name = (char *) (p + 1);
 105        if (special_name) {
 106                strcpy(p->name, special_name);
 107                p->length = special_len;
 108                p->value = prom_early_alloc(special_len);
 109                memcpy(p->value, special_val, special_len);
 110        } else {
 111                err = of_pdt_prom_ops->nextprop(node, prev, p->name);
 112                if (err) {
 113                        tmp = p;
 114                        return NULL;
 115                }
 116                p->length = of_pdt_prom_ops->getproplen(node, p->name);
 117                if (p->length <= 0) {
 118                        p->length = 0;
 119                } else {
 120                        int len;
 121
 122                        p->value = prom_early_alloc(p->length + 1);
 123                        len = of_pdt_prom_ops->getproperty(node, p->name,
 124                                        p->value, p->length);
 125                        if (len <= 0)
 126                                p->length = 0;
 127                        ((unsigned char *)p->value)[p->length] = '\0';
 128                }
 129        }
 130        return p;
 131}
 132
 133static struct property * __init of_pdt_build_prop_list(phandle node)
 134{
 135        struct property *head, *tail;
 136
 137        head = tail = of_pdt_build_one_prop(node, NULL,
 138                                     ".node", &node, sizeof(node));
 139
 140        tail->next = of_pdt_build_one_prop(node, NULL, NULL, NULL, 0);
 141        tail = tail->next;
 142        while(tail) {
 143                tail->next = of_pdt_build_one_prop(node, tail->name,
 144                                            NULL, NULL, 0);
 145                tail = tail->next;
 146        }
 147
 148        return head;
 149}
 150
 151static char * __init of_pdt_get_one_property(phandle node, const char *name)
 152{
 153        char *buf = "<NULL>";
 154        int len;
 155
 156        len = of_pdt_prom_ops->getproplen(node, name);
 157        if (len > 0) {
 158                buf = prom_early_alloc(len);
 159                len = of_pdt_prom_ops->getproperty(node, name, buf, len);
 160        }
 161
 162        return buf;
 163}
 164
 165static struct device_node * __init of_pdt_create_node(phandle node,
 166                                                    struct device_node *parent)
 167{
 168        struct device_node *dp;
 169
 170        if (!node)
 171                return NULL;
 172
 173        dp = prom_early_alloc(sizeof(*dp));
 174        of_node_init(dp);
 175        of_pdt_incr_unique_id(dp);
 176        dp->parent = parent;
 177
 178        dp->name = of_pdt_get_one_property(node, "name");
 179        dp->type = of_pdt_get_one_property(node, "device_type");
 180        dp->phandle = node;
 181
 182        dp->properties = of_pdt_build_prop_list(node);
 183
 184        irq_trans_init(dp);
 185
 186        return dp;
 187}
 188
 189static struct device_node * __init of_pdt_build_tree(struct device_node *parent,
 190                                                   phandle node)
 191{
 192        struct device_node *ret = NULL, *prev_sibling = NULL;
 193        struct device_node *dp;
 194
 195        while (1) {
 196                dp = of_pdt_create_node(node, parent);
 197                if (!dp)
 198                        break;
 199
 200                if (prev_sibling)
 201                        prev_sibling->sibling = dp;
 202
 203                if (!ret)
 204                        ret = dp;
 205                prev_sibling = dp;
 206
 207                dp->full_name = of_pdt_build_full_name(dp);
 208
 209                dp->child = of_pdt_build_tree(dp, of_pdt_prom_ops->getchild(node));
 210
 211                if (of_pdt_build_more)
 212                        of_pdt_build_more(dp);
 213
 214                node = of_pdt_prom_ops->getsibling(node);
 215        }
 216
 217        return ret;
 218}
 219
 220static void * __init kernel_tree_alloc(u64 size, u64 align)
 221{
 222        return prom_early_alloc(size);
 223}
 224
 225void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops)
 226{
 227        BUG_ON(!ops);
 228        of_pdt_prom_ops = ops;
 229
 230        of_root = of_pdt_create_node(root_node, NULL);
 231#if defined(CONFIG_SPARC)
 232        of_root->path_component_name = "";
 233#endif
 234        of_root->full_name = "/";
 235
 236        of_root->child = of_pdt_build_tree(of_root,
 237                                of_pdt_prom_ops->getchild(of_root->phandle));
 238
 239        /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
 240        of_alias_scan(kernel_tree_alloc);
 241}
 242