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 /* use when traversing tree through the allnext, child, sibling,
  31  * or parent members of struct device_node.
  32  */
  33 static DEFINE_RWLOCK(devtree_lock);
  34
  35 int of_device_is_compatible(struct device_node *device, const char *compat)
  36 {
  37         const char* cp;
  38         int cplen, l;
  39
  40         cp = (char *) of_get_property(device, "compatible", &cplen);
  41         if (cp == NULL)
  42                 return 0;
  43         while (cplen > 0) {
  44                 if (strncmp(cp, compat, strlen(compat)) == 0)
  45                         return 1;
  46                 l = strlen(cp) + 1;
  47                 cp += l;
  48                 cplen -= l;
  49         }
  50
  51         return 0;
  52 }
  53 EXPORT_SYMBOL(of_device_is_compatible);
  54
  55 struct device_node *of_get_parent(const struct device_node *node)
  56 {
  57         struct device_node *np;
  58
  59         if (!node)
  60                 return NULL;
  61
  62         np = node->parent;
  63
  64         return np;
  65 }
  66 EXPORT_SYMBOL(of_get_parent);
  67
  68 struct device_node *of_get_next_child(const struct device_node *node,
  69         struct device_node *prev)
  70 {
  71         struct device_node *next;
  72
  73         next = prev ? prev->sibling : node->child;
  74         for (; next != 0; next = next->sibling) {
  75                 break;
  76         }
  77
  78         return next;
  79 }
  80 EXPORT_SYMBOL(of_get_next_child);
  81
  82 struct device_node *of_find_node_by_path(const char *path)
  83 {
  84         struct device_node *np = allnodes;
  85
  86         for (; np != 0; np = np->allnext) {
  87                 if (np->full_name != 0 && strcmp(np->full_name, path) == 0)
  88                         break;
  89         }
  90
  91         return np;
  92 }
  93 EXPORT_SYMBOL(of_find_node_by_path);
  94
  95 struct device_node *of_find_node_by_phandle(phandle handle)
  96 {
  97         struct device_node *np;
  98
  99         for (np = allnodes; np != 0; np = np->allnext)
 100                 if (np->node == handle)
 101                         break;
 102
 103         return np;
 104 }
 105 EXPORT_SYMBOL(of_find_node_by_phandle);
 106
 107 struct device_node *of_find_node_by_name(struct device_node *from,
 108         const char *name)
 109 {
 110         struct device_node *np;
 111
 112         np = from ? from->allnext : allnodes;
 113         for (; np != NULL; np = np->allnext)
 114                 if (np->name != NULL && strcmp(np->name, name) == 0)
 115                         break;
 116
 117         return np;
 118 }
 119 EXPORT_SYMBOL(of_find_node_by_name);
 120
 121 struct device_node *of_find_node_by_type(struct device_node *from,
 122         const char *type)
 123 {
 124         struct device_node *np;
 125
 126         np = from ? from->allnext : allnodes;
 127         for (; np != 0; np = np->allnext)
 128                 if (np->type != 0 && strcmp(np->type, type) == 0)
 129                         break;
 130
 131         return np;
 132 }
 133 EXPORT_SYMBOL(of_find_node_by_type);
 134
 135 struct device_node *of_find_compatible_node(struct device_node *from,
 136         const char *type, const char *compatible)
 137 {
 138         struct device_node *np;
 139
 140         np = from ? from->allnext : allnodes;
 141         for (; np != 0; np = np->allnext) {
 142                 if (type != NULL
 143                     && !(np->type != 0 && strcmp(np->type, type) == 0))
 144                         continue;
 145                 if (of_device_is_compatible(np, compatible))
 146                         break;
 147         }
 148
 149         return np;
 150 }
 151 EXPORT_SYMBOL(of_find_compatible_node);
 152
 153 struct property *of_find_property(struct device_node *np, const char *name,
 154                                   int *lenp)
 155 {
 156         struct property *pp;
 157
 158         for (pp = np->properties; pp != 0; pp = pp->next) {
 159                 if (strcmp(pp->name, name) == 0) {
 160                         if (lenp != 0)
 161                                 *lenp = pp->length;
 162                         break;
 163                 }
 164         }
 165         return pp;
 166 }
 167 EXPORT_SYMBOL(of_find_property);
 168
 169 /*
 170  * Find a property with a given name for a given node
 171  * and return the value.
 172  */
 173 void *of_get_property(struct device_node *np, const char *name, int *lenp)
 174 {
 175         struct property *pp = of_find_property(np,name,lenp);
 176         return pp ? pp->value : NULL;
 177 }
 178 EXPORT_SYMBOL(of_get_property);
 179
 180 int of_getintprop_default(struct device_node *np, const char *name, int def)
 181 {
 182         struct property *prop;
 183         int len;
 184
 185         prop = of_find_property(np, name, &len);
 186         if (!prop || len != 4)
 187                 return def;
 188
 189         return *(int *) prop->value;
 190 }
 191 EXPORT_SYMBOL(of_getintprop_default);
 192
 193 int of_n_addr_cells(struct device_node *np)
 194 {
 195         int* ip;
 196         do {
 197                 if (np->parent)
 198                         np = np->parent;
 199                 ip = of_get_property(np, "#address-cells", NULL);
 200                 if (ip != NULL)
 201                         return *ip;
 202         } while (np->parent);
 203         /* No #address-cells property for the root node, default to 2 */
 204         return 2;
 205 }
 206 EXPORT_SYMBOL(of_n_addr_cells);
 207
 208 int of_n_size_cells(struct device_node *np)
 209 {
 210         int* ip;
 211         do {
 212                 if (np->parent)
 213                         np = np->parent;
 214                 ip = of_get_property(np, "#size-cells", NULL);
 215                 if (ip != NULL)
 216                         return *ip;
 217         } while (np->parent);
 218         /* No #size-cells property for the root node, default to 1 */
 219         return 1;
 220 }
 221 EXPORT_SYMBOL(of_n_size_cells);
 222
 223 int of_set_property(struct device_node *dp, const char *name, void *val, int len)
 224 {
 225         struct property **prevp;
 226         void *new_val;
 227         int err;
 228
 229         new_val = kmalloc(len, GFP_KERNEL);
 230         if (!new_val)
 231                 return -ENOMEM;
 232
 233         memcpy(new_val, val, len);
 234
 235         err = -ENODEV;
 236
 237         write_lock(&devtree_lock);
 238         prevp = &dp->properties;
 239         while (*prevp) {
 240                 struct property *prop = *prevp;
 241
 242                 if (!strcmp(prop->name, name)) {
 243                         void *old_val = prop->value;
 244                         int ret;
 245
 246                         ret = prom_setprop(dp->node, name, val, len);
 247                         err = -EINVAL;
 248                         if (ret >= 0) {
 249                                 prop->value = new_val;
 250                                 prop->length = len;
 251
 252                                 if (OF_IS_DYNAMIC(prop))
 253                                         kfree(old_val);
 254
 255                                 OF_MARK_DYNAMIC(prop);
 256
 257                                 err = 0;
 258                         }
 259                         break;
 260                 }
 261                 prevp = &(*prevp)->next;
 262         }
 263         write_unlock(&devtree_lock);
 264
 265         /* XXX Upate procfs if necessary... */
 266
 267         return err;
 268 }
 269 EXPORT_SYMBOL(of_set_property);
 270
 271 static unsigned int prom_early_allocated;
 272
 273 static void * __init prom_early_alloc(unsigned long size)
 274 {
 275         void *ret;
 276
 277         ret = __alloc_bootmem(size, SMP_CACHE_BYTES, 0UL);
 278         if (ret != NULL)
 279                 memset(ret, 0, size);
 280
 281         prom_early_allocated += size;
 282
 283         return ret;
 284 }
 285
 286 static int is_root_node(const struct device_node *dp)
 287 {
 288         if (!dp)
 289                 return 0;
 290
 291         return (dp->parent == NULL);
 292 }
 293
 294 /* The following routines deal with the black magic of fully naming a
 295  * node.
 296  *
 297  * Certain well known named nodes are just the simple name string.
 298  *
 299  * Actual devices have an address specifier appended to the base name
 300  * string, like this "foo@addr".  The "addr" can be in any number of
 301  * formats, and the platform plus the type of the node determine the
 302  * format and how it is constructed.
 303  *
 304  * For children of the ROOT node, the naming convention is fixed and
 305  * determined by whether this is a sun4u or sun4v system.
 306  *
 307  * For children of other nodes, it is bus type specific.  So
 308  * we walk up the tree until we discover a "device_type" property
 309  * we recognize and we go from there.
 310  */
 311 static void __init sparc32_path_component(struct device_node *dp, char *tmp_buf)
 312 {
 313         struct linux_prom_registers *regs;
 314         struct property *rprop;
 315
 316         rprop = of_find_property(dp, "reg", NULL);
 317         if (!rprop)
 318                 return;
 319
 320         regs = rprop->value;
 321         sprintf(tmp_buf, "%s@%x,%x",
 322                 dp->name,
 323                 regs->which_io, regs->phys_addr);
 324 }
 325
 326 /* "name@slot,offset"  */
 327 static void __init sbus_path_component(struct device_node *dp, char *tmp_buf)
 328 {
 329         struct linux_prom_registers *regs;
 330         struct property *prop;
 331
 332         prop = of_find_property(dp, "reg", NULL);
 333         if (!prop)
 334                 return;
 335
 336         regs = prop->value;
 337         sprintf(tmp_buf, "%s@%x,%x",
 338                 dp->name,
 339                 regs->which_io,
 340                 regs->phys_addr);
 341 }
 342
 343 /* "name@devnum[,func]" */
 344 static void __init pci_path_component(struct device_node *dp, char *tmp_buf)
 345 {
 346         struct linux_prom_pci_registers *regs;
 347         struct property *prop;
 348         unsigned int devfn;
 349
 350         prop = of_find_property(dp, "reg", NULL);
 351         if (!prop)
 352                 return;
 353
 354         regs = prop->value;
 355         devfn = (regs->phys_hi >> 8) & 0xff;
 356         if (devfn & 0x07) {
 357                 sprintf(tmp_buf, "%s@%x,%x",
 358                         dp->name,
 359                         devfn >> 3,
 360                         devfn & 0x07);
 361         } else {
 362                 sprintf(tmp_buf, "%s@%x",
 363                         dp->name,
 364                         devfn >> 3);
 365         }
 366 }
 367
 368 /* "name@addrhi,addrlo" */
 369 static void __init ebus_path_component(struct device_node *dp, char *tmp_buf)
 370 {
 371         struct linux_prom_registers *regs;
 372         struct property *prop;
 373
 374         prop = of_find_property(dp, "reg", NULL);
 375         if (!prop)
 376                 return;
 377
 378         regs = prop->value;
 379
 380         sprintf(tmp_buf, "%s@%x,%x",
 381                 dp->name,
 382                 regs->which_io, regs->phys_addr);
 383 }
 384
 385 static void __init __build_path_component(struct device_node *dp, char *tmp_buf)
 386 {
 387         struct device_node *parent = dp->parent;
 388
 389         if (parent != NULL) {
 390                 if (!strcmp(parent->type, "pci") ||
 391                     !strcmp(parent->type, "pciex"))
 392                         return pci_path_component(dp, tmp_buf);
 393                 if (!strcmp(parent->type, "sbus"))
 394                         return sbus_path_component(dp, tmp_buf);
 395                 if (!strcmp(parent->type, "ebus"))
 396                         return ebus_path_component(dp, tmp_buf);
 397
 398                 /* "isa" is handled with platform naming */
 399         }
 400
 401         /* Use platform naming convention.  */
 402         return sparc32_path_component(dp, tmp_buf);
 403 }
 404
 405 static char * __init build_path_component(struct device_node *dp)
 406 {
 407         char tmp_buf[64], *n;
 408
 409         tmp_buf[0] = '\0';
 410         __build_path_component(dp, tmp_buf);
 411         if (tmp_buf[0] == '\0')
 412                 strcpy(tmp_buf, dp->name);
 413
 414         n = prom_early_alloc(strlen(tmp_buf) + 1);
 415         strcpy(n, tmp_buf);
 416
 417         return n;
 418 }
 419
 420 static char * __init build_full_name(struct device_node *dp)
 421 {
 422         int len, ourlen, plen;
 423         char *n;
 424
 425         plen = strlen(dp->parent->full_name);
 426         ourlen = strlen(dp->path_component_name);
 427         len = ourlen + plen + 2;
 428
 429         n = prom_early_alloc(len);
 430         strcpy(n, dp->parent->full_name);
 431         if (!is_root_node(dp->parent)) {
 432                 strcpy(n + plen, "/");
 433                 plen++;
 434         }
 435         strcpy(n + plen, dp->path_component_name);
 436
 437         return n;
 438 }
 439
 440 static unsigned int unique_id;
 441
 442 static struct property * __init build_one_prop(phandle node, char *prev, char *special_name, void *special_val, int special_len)
 443 {
 444         static struct property *tmp = NULL;
 445         struct property *p;
 446         int len;
 447         const char *name;
 448
 449         if (tmp) {
 450                 p = tmp;
 451                 memset(p, 0, sizeof(*p) + 32);
 452                 tmp = NULL;
 453         } else {
 454                 p = prom_early_alloc(sizeof(struct property) + 32);
 455                 p->unique_id = unique_id++;
 456         }
 457
 458         p->name = (char *) (p + 1);
 459         if (special_name) {
 460                 strcpy(p->name, special_name);
 461                 p->length = special_len;
 462                 p->value = prom_early_alloc(special_len);
 463                 memcpy(p->value, special_val, special_len);
 464         } else {
 465                 if (prev == NULL) {
 466                         name = prom_firstprop(node, NULL);
 467                 } else {
 468                         name = prom_nextprop(node, prev, NULL);
 469                 }
 470                 if (strlen(name) == 0) {
 471                         tmp = p;
 472                         return NULL;
 473                 }
 474                 strcpy(p->name, name);
 475                 p->length = prom_getproplen(node, p->name);
 476                 if (p->length <= 0) {
 477                         p->length = 0;
 478                 } else {
 479                         p->value = prom_early_alloc(p->length + 1);
 480                         prom_getproperty(node, p->name, p->value, p->length);
 481                         ((unsigned char *)p->value)[p->length] = '\0';
 482                 }
 483         }
 484         return p;
 485 }
 486
 487 static struct property * __init build_prop_list(phandle node)
 488 {
 489         struct property *head, *tail;
 490
 491         head = tail = build_one_prop(node, NULL,
 492                                      ".node", &node, sizeof(node));
 493
 494         tail->next = build_one_prop(node, NULL, NULL, NULL, 0);
 495         tail = tail->next;
 496         while(tail) {
 497                 tail->next = build_one_prop(node, tail->name,
 498                                             NULL, NULL, 0);
 499                 tail = tail->next;
 500         }
 501
 502         return head;
 503 }
 504
 505 static char * __init get_one_property(phandle node, char *name)
 506 {
 507         char *buf = "<NULL>";
 508         int len;
 509
 510         len = prom_getproplen(node, name);
 511         if (len > 0) {
 512                 buf = prom_early_alloc(len);
 513                 len = prom_getproperty(node, name, buf, len);
 514         }
 515
 516         return buf;
 517 }
 518
 519 static struct device_node * __init create_node(phandle node)
 520 {
 521         struct device_node *dp;
 522
 523         if (!node)
 524                 return NULL;
 525
 526         dp = prom_early_alloc(sizeof(*dp));
 527         dp->unique_id = unique_id++;
 528
 529         kref_init(&dp->kref);
 530
 531         dp->name = get_one_property(node, "name");
 532         dp->type = get_one_property(node, "device_type");
 533         dp->node = node;
 534
 535         /* Build interrupts later... */
 536
 537         dp->properties = build_prop_list(node);
 538
 539         return dp;
 540 }
 541
 542 static struct device_node * __init build_tree(struct device_node *parent, phandle node, struct device_node ***nextp)
 543 {
 544         struct device_node *dp;
 545
 546         dp = create_node(node);
 547         if (dp) {
 548                 *(*nextp) = dp;
 549                 *nextp = &dp->allnext;
 550
 551                 dp->parent = parent;
 552                 dp->path_component_name = build_path_component(dp);
 553                 dp->full_name = build_full_name(dp);
 554
 555                 dp->child = build_tree(dp, prom_getchild(node), nextp);
 556
 557                 dp->sibling = build_tree(parent, prom_getsibling(node), nextp);
 558         }
 559
 560         return dp;
 561 }
 562
 563 void __init prom_build_devicetree(void)
 564 {
 565         struct device_node **nextp;
 566
 567         allnodes = create_node(prom_root_node);
 568         allnodes->path_component_name = "";
 569         allnodes->full_name = "/";
 570
 571         nextp = &allnodes->allnext;
 572         allnodes->child = build_tree(allnodes,
 573                                      prom_getchild(allnodes->node),
 574                                      &nextp);
 575         printk("PROM: Built device tree with %u bytes of memory.\n",
 576                prom_early_allocated);
 577 }