drivers/of/pdt.c

   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
  27 static struct of_pdt_ops *of_pdt_prom_ops __initdata;
  28
  29 void __initdata (*of_pdt_build_more)(struct device_node *dp,
  30                 struct device_node ***nextp);
  31
  32 #if defined(CONFIG_SPARC)
  33 unsigned 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
  39 static inline const char *of_pdt_node_name(struct device_node *dp)
  40 {
  41         return dp->path_component_name;
  42 }
  43
  44 #else
  45
  46 static inline void of_pdt_incr_unique_id(void *p) { }
  47 static inline void irq_trans_init(struct device_node *dp) { }
  48
  49 static inline const char *of_pdt_node_name(struct device_node *dp)
  50 {
  51         return dp->name;
  52 }
  53
  54 #endif /* !CONFIG_SPARC */
  55
  56 static struct property * __init of_pdt_build_one_prop(phandle node, char *prev,
  57                                                char *special_name,
  58                                                void *special_val,
  59                                                int special_len)
  60 {
  61         static struct property *tmp = NULL;
  62         struct property *p;
  63         int err;
  64
  65         if (tmp) {
  66                 p = tmp;
  67                 memset(p, 0, sizeof(*p) + 32);
  68                 tmp = NULL;
  69         } else {
  70                 p = prom_early_alloc(sizeof(struct property) + 32);
  71                 of_pdt_incr_unique_id(p);
  72         }
  73
  74         p->name = (char *) (p + 1);
  75         if (special_name) {
  76                 strcpy(p->name, special_name);
  77                 p->length = special_len;
  78                 p->value = prom_early_alloc(special_len);
  79                 memcpy(p->value, special_val, special_len);
  80         } else {
  81                 err = of_pdt_prom_ops->nextprop(node, prev, p->name);
  82                 if (err) {
  83                         tmp = p;
  84                         return NULL;
  85                 }
  86                 p->length = of_pdt_prom_ops->getproplen(node, p->name);
  87                 if (p->length <= 0) {
  88                         p->length = 0;
  89                 } else {
  90                         int len;
  91
  92                         p->value = prom_early_alloc(p->length + 1);
  93                         len = of_pdt_prom_ops->getproperty(node, p->name,
  94                                         p->value, p->length);
  95                         if (len <= 0)
  96                                 p->length = 0;
  97                         ((unsigned char *)p->value)[p->length] = '\0';
  98                 }
  99         }
 100         return p;
 101 }
 102
 103 static struct property * __init of_pdt_build_prop_list(phandle node)
 104 {
 105         struct property *head, *tail;
 106
 107         head = tail = of_pdt_build_one_prop(node, NULL,
 108                                      ".node", &node, sizeof(node));
 109
 110         tail->next = of_pdt_build_one_prop(node, NULL, NULL, NULL, 0);
 111         tail = tail->next;
 112         while(tail) {
 113                 tail->next = of_pdt_build_one_prop(node, tail->name,
 114                                             NULL, NULL, 0);
 115                 tail = tail->next;
 116         }
 117
 118         return head;
 119 }
 120
 121 static char * __init of_pdt_get_one_property(phandle node, const char *name)
 122 {
 123         char *buf = "<NULL>";
 124         int len;
 125
 126         len = of_pdt_prom_ops->getproplen(node, name);
 127         if (len > 0) {
 128                 buf = prom_early_alloc(len);
 129                 len = of_pdt_prom_ops->getproperty(node, name, buf, len);
 130         }
 131
 132         return buf;
 133 }
 134
 135 static char * __init of_pdt_try_pkg2path(phandle node)
 136 {
 137         char *res, *buf = NULL;
 138         int len;
 139
 140         if (!of_pdt_prom_ops->pkg2path)
 141                 return NULL;
 142
 143         if (of_pdt_prom_ops->pkg2path(node, buf, 0, &len))
 144                 return NULL;
 145         buf = prom_early_alloc(len + 1);
 146         if (of_pdt_prom_ops->pkg2path(node, buf, len, &len)) {
 147                 pr_err("%s: package-to-path failed\n", __func__);
 148                 return NULL;
 149         }
 150
 151         res = strrchr(buf, '/');
 152         if (!res) {
 153                 pr_err("%s: couldn't find / in %s\n", __func__, buf);
 154                 return NULL;
 155         }
 156         return res+1;
 157 }
 158
 159 /*
 160  * When fetching the node's name, first try using package-to-path; if
 161  * that fails (either because the arch hasn't supplied a PROM callback,
 162  * or some other random failure), fall back to just looking at the node's
 163  * 'name' property.
 164  */
 165 static char * __init of_pdt_build_name(phandle node)
 166 {
 167         char *buf;
 168
 169         buf = of_pdt_try_pkg2path(node);
 170         if (!buf)
 171                 buf = of_pdt_get_one_property(node, "name");
 172
 173         return buf;
 174 }
 175
 176 static struct device_node * __init of_pdt_create_node(phandle node,
 177                                                     struct device_node *parent)
 178 {
 179         struct device_node *dp;
 180
 181         if (!node)
 182                 return NULL;
 183
 184         dp = prom_early_alloc(sizeof(*dp));
 185         of_pdt_incr_unique_id(dp);
 186         dp->parent = parent;
 187
 188         kref_init(&dp->kref);
 189
 190         dp->name = of_pdt_build_name(node);
 191         dp->type = of_pdt_get_one_property(node, "device_type");
 192         dp->phandle = node;
 193
 194         dp->properties = of_pdt_build_prop_list(node);
 195
 196         irq_trans_init(dp);
 197
 198         return dp;
 199 }
 200
 201 static char * __init of_pdt_build_full_name(struct device_node *dp)
 202 {
 203         int len, ourlen, plen;
 204         char *n;
 205
 206         plen = strlen(dp->parent->full_name);
 207         ourlen = strlen(of_pdt_node_name(dp));
 208         len = ourlen + plen + 2;
 209
 210         n = prom_early_alloc(len);
 211         strcpy(n, dp->parent->full_name);
 212         if (!of_node_is_root(dp->parent)) {
 213                 strcpy(n + plen, "/");
 214                 plen++;
 215         }
 216         strcpy(n + plen, of_pdt_node_name(dp));
 217
 218         return n;
 219 }
 220
 221 static struct device_node * __init of_pdt_build_tree(struct device_node *parent,
 222                                                    phandle node,
 223                                                    struct device_node ***nextp)
 224 {
 225         struct device_node *ret = NULL, *prev_sibling = NULL;
 226         struct device_node *dp;
 227
 228         while (1) {
 229                 dp = of_pdt_create_node(node, parent);
 230                 if (!dp)
 231                         break;
 232
 233                 if (prev_sibling)
 234                         prev_sibling->sibling = dp;
 235
 236                 if (!ret)
 237                         ret = dp;
 238                 prev_sibling = dp;
 239
 240                 *(*nextp) = dp;
 241                 *nextp = &dp->allnext;
 242
 243 #if defined(CONFIG_SPARC)
 244                 dp->path_component_name = build_path_component(dp);
 245 #endif
 246                 dp->full_name = of_pdt_build_full_name(dp);
 247
 248                 dp->child = of_pdt_build_tree(dp,
 249                                 of_pdt_prom_ops->getchild(node), nextp);
 250
 251                 if (of_pdt_build_more)
 252                         of_pdt_build_more(dp, nextp);
 253
 254                 node = of_pdt_prom_ops->getsibling(node);
 255         }
 256
 257         return ret;
 258 }
 259
 260 void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops)
 261 {
 262         struct device_node **nextp;
 263
 264         BUG_ON(!ops);
 265         of_pdt_prom_ops = ops;
 266
 267         allnodes = of_pdt_create_node(root_node, NULL);
 268 #if defined(CONFIG_SPARC)
 269         allnodes->path_component_name = "";
 270 #endif
 271         allnodes->full_name = "/";
 272
 273         nextp = &allnodes->allnext;
 274         allnodes->child = of_pdt_build_tree(allnodes,
 275                         of_pdt_prom_ops->getchild(allnodes->phandle), &nextp);
 276 }