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