kernel/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
  30 #if defined(CONFIG_SPARC)
  31 unsigned 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
  37 static 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
  61 static inline void of_pdt_incr_unique_id(void *p) { }
  62 static inline void irq_trans_init(struct device_node *dp) { }
  63
  64 static 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
  90 static 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
 137 static 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
 155 static 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
 169 static 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
 193 static 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
 224 static void * __init kernel_tree_alloc(u64 size, u64 align)
 225 {
 226         return prom_early_alloc(size);
 227 }
 228
 229 void __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 }