arch/sparc/kernel/prom.c

   1 /*
   2  * Procedures for creating, accessing and interpreting the device tree.
   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 sparc32 by David S. Miller davem@davemloft.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/types.h>
  20 #include <linux/string.h>
  21 #include <linux/mm.h>
  22 #include <linux/bootmem.h>
  23 #include <linux/module.h>
  24
  25 #include <asm/prom.h>
  26 #include <asm/oplib.h>
  27
  28 static struct device_node *allnodes;
  29
  30 int of_device_is_compatible(struct device_node *device, const char *compat)
  31 {
  32         const char* cp;
  33         int cplen, l;
  34
  35         cp = (char *) of_get_property(device, "compatible", &cplen);
  36         if (cp == NULL)
  37                 return 0;
  38         while (cplen > 0) {
  39                 if (strncmp(cp, compat, strlen(compat)) == 0)
  40                         return 1;
  41                 l = strlen(cp) + 1;
  42                 cp += l;
  43                 cplen -= l;
  44         }
  45
  46         return 0;
  47 }
  48 EXPORT_SYMBOL(of_device_is_compatible);
  49
  50 struct device_node *of_get_parent(const struct device_node *node)
  51 {
  52         struct device_node *np;
  53
  54         if (!node)
  55                 return NULL;
  56
  57         np = node->parent;
  58
  59         return np;
  60 }
  61 EXPORT_SYMBOL(of_get_parent);
  62
  63 struct device_node *of_get_next_child(const struct device_node *node,
  64         struct device_node *prev)
  65 {
  66         struct device_node *next;
  67
  68         next = prev ? prev->sibling : node->child;
  69         for (; next != 0; next = next->sibling) {
  70                 break;
  71         }
  72
  73         return next;
  74 }
  75 EXPORT_SYMBOL(of_get_next_child);
  76
  77 struct device_node *of_find_node_by_path(const char *path)
  78 {
  79         struct device_node *np = allnodes;
  80
  81         for (; np != 0; np = np->allnext) {
  82                 if (np->full_name != 0 && strcmp(np->full_name, path) == 0)
  83                         break;
  84         }
  85
  86         return np;
  87 }
  88 EXPORT_SYMBOL(of_find_node_by_path);
  89
  90 struct device_node *of_find_node_by_phandle(phandle handle)
  91 {
  92         struct device_node *np;
  93
  94         for (np = allnodes; np != 0; np = np->allnext)
  95                 if (np->node == handle)
  96                         break;
  97
  98         return np;
  99 }
 100 EXPORT_SYMBOL(of_find_node_by_phandle);
 101
 102 struct device_node *of_find_node_by_name(struct device_node *from,
 103         const char *name)
 104 {
 105         struct device_node *np;
 106
 107         np = from ? from->allnext : allnodes;
 108         for (; np != NULL; np = np->allnext)
 109                 if (np->name != NULL && strcmp(np->name, name) == 0)
 110                         break;
 111
 112         return np;
 113 }
 114 EXPORT_SYMBOL(of_find_node_by_name);
 115
 116 struct device_node *of_find_node_by_type(struct device_node *from,
 117         const char *type)
 118 {
 119         struct device_node *np;
 120
 121         np = from ? from->allnext : allnodes;
 122         for (; np != 0; np = np->allnext)
 123                 if (np->type != 0 && strcmp(np->type, type) == 0)
 124                         break;
 125
 126         return np;
 127 }
 128 EXPORT_SYMBOL(of_find_node_by_type);
 129
 130 struct device_node *of_find_compatible_node(struct device_node *from,
 131         const char *type, const char *compatible)
 132 {
 133         struct device_node *np;
 134
 135         np = from ? from->allnext : allnodes;
 136         for (; np != 0; np = np->allnext) {
 137                 if (type != NULL
 138                     && !(np->type != 0 && strcmp(np->type, type) == 0))
 139                         continue;
 140                 if (of_device_is_compatible(np, compatible))
 141                         break;
 142         }
 143
 144         return np;
 145 }
 146 EXPORT_SYMBOL(of_find_compatible_node);
 147
 148 struct property *of_find_property(struct device_node *np, const char *name,
 149                                   int *lenp)
 150 {
 151         struct property *pp;
 152
 153         for (pp = np->properties; pp != 0; pp = pp->next) {
 154                 if (strcmp(pp->name, name) == 0) {
 155                         if (lenp != 0)
 156                                 *lenp = pp->length;
 157                         break;
 158                 }
 159         }
 160         return pp;
 161 }
 162 EXPORT_SYMBOL(of_find_property);
 163
 164 /*
 165  * Find a property with a given name for a given node
 166  * and return the value.
 167  */
 168 void *of_get_property(struct device_node *np, const char *name, int *lenp)
 169 {
 170         struct property *pp = of_find_property(np,name,lenp);
 171         return pp ? pp->value : NULL;
 172 }
 173 EXPORT_SYMBOL(of_get_property);
 174
 175 int of_getintprop_default(struct device_node *np, const char *name, int def)
 176 {
 177         struct property *prop;
 178         int len;
 179
 180         prop = of_find_property(np, name, &len);
 181         if (!prop || len != 4)
 182                 return def;
 183
 184         return *(int *) prop->value;
 185 }
 186 EXPORT_SYMBOL(of_getintprop_default);
 187
 188 static unsigned int prom_early_allocated;
 189
 190 static void * __init prom_early_alloc(unsigned long size)
 191 {
 192         void *ret;
 193
 194         ret = __alloc_bootmem(size, SMP_CACHE_BYTES, 0UL);
 195         if (ret != NULL)
 196                 memset(ret, 0, size);
 197
 198         prom_early_allocated += size;
 199
 200         return ret;
 201 }
 202
 203 static int is_root_node(const struct device_node *dp)
 204 {
 205         if (!dp)
 206                 return 0;
 207
 208         return (dp->parent == NULL);
 209 }
 210
 211 /* The following routines deal with the black magic of fully naming a
 212  * node.
 213  *
 214  * Certain well known named nodes are just the simple name string.
 215  *
 216  * Actual devices have an address specifier appended to the base name
 217  * string, like this "foo@addr".  The "addr" can be in any number of
 218  * formats, and the platform plus the type of the node determine the
 219  * format and how it is constructed.
 220  *
 221  * For children of the ROOT node, the naming convention is fixed and
 222  * determined by whether this is a sun4u or sun4v system.
 223  *
 224  * For children of other nodes, it is bus type specific.  So
 225  * we walk up the tree until we discover a "device_type" property
 226  * we recognize and we go from there.
 227  */
 228 static void __init sparc32_path_component(struct device_node *dp, char *tmp_buf)
 229 {
 230         struct linux_prom_registers *regs;
 231         struct property *rprop;
 232
 233         rprop = of_find_property(dp, "reg", NULL);
 234         if (!rprop)
 235                 return;
 236
 237         regs = rprop->value;
 238         sprintf(tmp_buf, "%s@%x,%x",
 239                 dp->name,
 240                 regs->which_io, regs->phys_addr);
 241 }
 242
 243 /* "name@slot,offset"  */
 244 static void __init sbus_path_component(struct device_node *dp, char *tmp_buf)
 245 {
 246         struct linux_prom_registers *regs;
 247         struct property *prop;
 248
 249         prop = of_find_property(dp, "reg", NULL);
 250         if (!prop)
 251                 return;
 252
 253         regs = prop->value;
 254         sprintf(tmp_buf, "%s@%x,%x",
 255                 dp->name,
 256                 regs->which_io,
 257                 regs->phys_addr);
 258 }
 259
 260 /* "name@devnum[,func]" */
 261 static void __init pci_path_component(struct device_node *dp, char *tmp_buf)
 262 {
 263         struct linux_prom_pci_registers *regs;
 264         struct property *prop;
 265         unsigned int devfn;
 266
 267         prop = of_find_property(dp, "reg", NULL);
 268         if (!prop)
 269                 return;
 270
 271         regs = prop->value;
 272         devfn = (regs->phys_hi >> 8) & 0xff;
 273         if (devfn & 0x07) {
 274                 sprintf(tmp_buf, "%s@%x,%x",
 275                         dp->name,
 276                         devfn >> 3,
 277                         devfn & 0x07);
 278         } else {
 279                 sprintf(tmp_buf, "%s@%x",
 280                         dp->name,
 281                         devfn >> 3);
 282         }
 283 }
 284
 285 /* "name@addrhi,addrlo" */
 286 static void __init ebus_path_component(struct device_node *dp, char *tmp_buf)
 287 {
 288         struct linux_prom_registers *regs;
 289         struct property *prop;
 290
 291         prop = of_find_property(dp, "reg", NULL);
 292         if (!prop)
 293                 return;
 294
 295         regs = prop->value;
 296
 297         sprintf(tmp_buf, "%s@%x,%x",
 298                 dp->name,
 299                 regs->which_io, regs->phys_addr);
 300 }
 301
 302 static void __init __build_path_component(struct device_node *dp, char *tmp_buf)
 303 {
 304         struct device_node *parent = dp->parent;
 305
 306         if (parent != NULL) {
 307                 if (!strcmp(parent->type, "pci") ||
 308                     !strcmp(parent->type, "pciex"))
 309                         return pci_path_component(dp, tmp_buf);
 310                 if (!strcmp(parent->type, "sbus"))
 311                         return sbus_path_component(dp, tmp_buf);
 312                 if (!strcmp(parent->type, "ebus"))
 313                         return ebus_path_component(dp, tmp_buf);
 314
 315                 /* "isa" is handled with platform naming */
 316         }
 317
 318         /* Use platform naming convention.  */
 319         return sparc32_path_component(dp, tmp_buf);
 320 }
 321
 322 static char * __init build_path_component(struct device_node *dp)
 323 {
 324         char tmp_buf[64], *n;
 325
 326         tmp_buf[0] = '\0';
 327         __build_path_component(dp, tmp_buf);
 328         if (tmp_buf[0] == '\0')
 329                 strcpy(tmp_buf, dp->name);
 330
 331         n = prom_early_alloc(strlen(tmp_buf) + 1);
 332         strcpy(n, tmp_buf);
 333
 334         return n;
 335 }
 336
 337 static char * __init build_full_name(struct device_node *dp)
 338 {
 339         int len, ourlen, plen;
 340         char *n;
 341
 342         plen = strlen(dp->parent->full_name);
 343         ourlen = strlen(dp->path_component_name);
 344         len = ourlen + plen + 2;
 345
 346         n = prom_early_alloc(len);
 347         strcpy(n, dp->parent->full_name);
 348         if (!is_root_node(dp->parent)) {
 349                 strcpy(n + plen, "/");
 350                 plen++;
 351         }
 352         strcpy(n + plen, dp->path_component_name);
 353
 354         return n;
 355 }
 356
 357 static struct property * __init build_one_prop(phandle node, char *prev)
 358 {
 359         static struct property *tmp = NULL;
 360         struct property *p;
 361         int len;
 362
 363         if (tmp) {
 364                 p = tmp;
 365                 memset(p, 0, sizeof(*p) + 32);
 366                 tmp = NULL;
 367         } else
 368                 p = prom_early_alloc(sizeof(struct property) + 32);
 369
 370         p->name = (char *) (p + 1);
 371         if (prev == NULL) {
 372                 prom_firstprop(node, p->name);
 373         } else {
 374                 prom_nextprop(node, prev, p->name);
 375         }
 376         if (strlen(p->name) == 0) {
 377                 tmp = p;
 378                 return NULL;
 379         }
 380         p->length = prom_getproplen(node, p->name);
 381         if (p->length <= 0) {
 382                 p->length = 0;
 383         } else {
 384                 p->value = prom_early_alloc(p->length);
 385                 len = prom_getproperty(node, p->name, p->value, p->length);
 386         }
 387         return p;
 388 }
 389
 390 static struct property * __init build_prop_list(phandle node)
 391 {
 392         struct property *head, *tail;
 393
 394         head = tail = build_one_prop(node, NULL);
 395         while(tail) {
 396                 tail->next = build_one_prop(node, tail->name);
 397                 tail = tail->next;
 398         }
 399
 400         return head;
 401 }
 402
 403 static char * __init get_one_property(phandle node, char *name)
 404 {
 405         char *buf = "<NULL>";
 406         int len;
 407
 408         len = prom_getproplen(node, name);
 409         if (len > 0) {
 410                 buf = prom_early_alloc(len);
 411                 len = prom_getproperty(node, name, buf, len);
 412         }
 413
 414         return buf;
 415 }
 416
 417 static struct device_node * __init create_node(phandle node)
 418 {
 419         struct device_node *dp;
 420
 421         if (!node)
 422                 return NULL;
 423
 424         dp = prom_early_alloc(sizeof(*dp));
 425
 426         kref_init(&dp->kref);
 427
 428         dp->name = get_one_property(node, "name");
 429         dp->type = get_one_property(node, "device_type");
 430         dp->node = node;
 431
 432         /* Build interrupts later... */
 433
 434         dp->properties = build_prop_list(node);
 435
 436         return dp;
 437 }
 438
 439 static struct device_node * __init build_tree(struct device_node *parent, phandle node, struct device_node ***nextp)
 440 {
 441         struct device_node *dp;
 442
 443         dp = create_node(node);
 444         if (dp) {
 445                 *(*nextp) = dp;
 446                 *nextp = &dp->allnext;
 447
 448                 dp->parent = parent;
 449                 dp->path_component_name = build_path_component(dp);
 450                 dp->full_name = build_full_name(dp);
 451
 452                 dp->child = build_tree(dp, prom_getchild(node), nextp);
 453
 454                 dp->sibling = build_tree(parent, prom_getsibling(node), nextp);
 455         }
 456
 457         return dp;
 458 }
 459
 460 void __init prom_build_devicetree(void)
 461 {
 462         struct device_node **nextp;
 463
 464         allnodes = create_node(prom_root_node);
 465         allnodes->path_component_name = "";
 466         allnodes->full_name = "/";
 467
 468         nextp = &allnodes->allnext;
 469         allnodes->child = build_tree(allnodes,
 470                                      prom_getchild(allnodes->node),
 471                                      &nextp);
 472         printk("PROM: Built device tree with %u bytes of memory.\n",
 473                prom_early_allocated);
 474 }