linux/drivers/of/base.c
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   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 sparc and sparc64 by David S. Miller davem@davemloft.net
  11 *
  12 *  Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
  13 *  Grant Likely.
  14 *
  15 *      This program is free software; you can redistribute it and/or
  16 *      modify it under the terms of the GNU General Public License
  17 *      as published by the Free Software Foundation; either version
  18 *      2 of the License, or (at your option) any later version.
  19 */
  20#include <linux/ctype.h>
  21#include <linux/module.h>
  22#include <linux/of.h>
  23#include <linux/spinlock.h>
  24#include <linux/slab.h>
  25#include <linux/proc_fs.h>
  26
  27#include "of_private.h"
  28
  29LIST_HEAD(aliases_lookup);
  30
  31struct device_node *of_allnodes;
  32EXPORT_SYMBOL(of_allnodes);
  33struct device_node *of_chosen;
  34struct device_node *of_aliases;
  35
  36DEFINE_MUTEX(of_aliases_mutex);
  37
  38/* use when traversing tree through the allnext, child, sibling,
  39 * or parent members of struct device_node.
  40 */
  41DEFINE_RAW_SPINLOCK(devtree_lock);
  42
  43int of_n_addr_cells(struct device_node *np)
  44{
  45        const __be32 *ip;
  46
  47        do {
  48                if (np->parent)
  49                        np = np->parent;
  50                ip = of_get_property(np, "#address-cells", NULL);
  51                if (ip)
  52                        return be32_to_cpup(ip);
  53        } while (np->parent);
  54        /* No #address-cells property for the root node */
  55        return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
  56}
  57EXPORT_SYMBOL(of_n_addr_cells);
  58
  59int of_n_size_cells(struct device_node *np)
  60{
  61        const __be32 *ip;
  62
  63        do {
  64                if (np->parent)
  65                        np = np->parent;
  66                ip = of_get_property(np, "#size-cells", NULL);
  67                if (ip)
  68                        return be32_to_cpup(ip);
  69        } while (np->parent);
  70        /* No #size-cells property for the root node */
  71        return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
  72}
  73EXPORT_SYMBOL(of_n_size_cells);
  74
  75#if defined(CONFIG_OF_DYNAMIC)
  76/**
  77 *      of_node_get - Increment refcount of a node
  78 *      @node:  Node to inc refcount, NULL is supported to
  79 *              simplify writing of callers
  80 *
  81 *      Returns node.
  82 */
  83struct device_node *of_node_get(struct device_node *node)
  84{
  85        if (node)
  86                kref_get(&node->kref);
  87        return node;
  88}
  89EXPORT_SYMBOL(of_node_get);
  90
  91static inline struct device_node *kref_to_device_node(struct kref *kref)
  92{
  93        return container_of(kref, struct device_node, kref);
  94}
  95
  96/**
  97 *      of_node_release - release a dynamically allocated node
  98 *      @kref:  kref element of the node to be released
  99 *
 100 *      In of_node_put() this function is passed to kref_put()
 101 *      as the destructor.
 102 */
 103static void of_node_release(struct kref *kref)
 104{
 105        struct device_node *node = kref_to_device_node(kref);
 106        struct property *prop = node->properties;
 107
 108        /* We should never be releasing nodes that haven't been detached. */
 109        if (!of_node_check_flag(node, OF_DETACHED)) {
 110                pr_err("ERROR: Bad of_node_put() on %s\n", node->full_name);
 111                dump_stack();
 112                kref_init(&node->kref);
 113                return;
 114        }
 115
 116        if (!of_node_check_flag(node, OF_DYNAMIC))
 117                return;
 118
 119        while (prop) {
 120                struct property *next = prop->next;
 121                kfree(prop->name);
 122                kfree(prop->value);
 123                kfree(prop);
 124                prop = next;
 125
 126                if (!prop) {
 127                        prop = node->deadprops;
 128                        node->deadprops = NULL;
 129                }
 130        }
 131        kfree(node->full_name);
 132        kfree(node->data);
 133        kfree(node);
 134}
 135
 136/**
 137 *      of_node_put - Decrement refcount of a node
 138 *      @node:  Node to dec refcount, NULL is supported to
 139 *              simplify writing of callers
 140 *
 141 */
 142void of_node_put(struct device_node *node)
 143{
 144        if (node)
 145                kref_put(&node->kref, of_node_release);
 146}
 147EXPORT_SYMBOL(of_node_put);
 148#endif /* CONFIG_OF_DYNAMIC */
 149
 150static struct property *__of_find_property(const struct device_node *np,
 151                                           const char *name, int *lenp)
 152{
 153        struct property *pp;
 154
 155        if (!np)
 156                return NULL;
 157
 158        for (pp = np->properties; pp; pp = pp->next) {
 159                if (of_prop_cmp(pp->name, name) == 0) {
 160                        if (lenp)
 161                                *lenp = pp->length;
 162                        break;
 163                }
 164        }
 165
 166        return pp;
 167}
 168
 169struct property *of_find_property(const struct device_node *np,
 170                                  const char *name,
 171                                  int *lenp)
 172{
 173        struct property *pp;
 174        unsigned long flags;
 175
 176        raw_spin_lock_irqsave(&devtree_lock, flags);
 177        pp = __of_find_property(np, name, lenp);
 178        raw_spin_unlock_irqrestore(&devtree_lock, flags);
 179
 180        return pp;
 181}
 182EXPORT_SYMBOL(of_find_property);
 183
 184/**
 185 * of_find_all_nodes - Get next node in global list
 186 * @prev:       Previous node or NULL to start iteration
 187 *              of_node_put() will be called on it
 188 *
 189 * Returns a node pointer with refcount incremented, use
 190 * of_node_put() on it when done.
 191 */
 192struct device_node *of_find_all_nodes(struct device_node *prev)
 193{
 194        struct device_node *np;
 195
 196        raw_spin_lock(&devtree_lock);
 197        np = prev ? prev->allnext : of_allnodes;
 198        for (; np != NULL; np = np->allnext)
 199                if (of_node_get(np))
 200                        break;
 201        of_node_put(prev);
 202        raw_spin_unlock(&devtree_lock);
 203        return np;
 204}
 205EXPORT_SYMBOL(of_find_all_nodes);
 206
 207/*
 208 * Find a property with a given name for a given node
 209 * and return the value.
 210 */
 211static const void *__of_get_property(const struct device_node *np,
 212                                     const char *name, int *lenp)
 213{
 214        struct property *pp = __of_find_property(np, name, lenp);
 215
 216        return pp ? pp->value : NULL;
 217}
 218
 219/*
 220 * Find a property with a given name for a given node
 221 * and return the value.
 222 */
 223const void *of_get_property(const struct device_node *np, const char *name,
 224                            int *lenp)
 225{
 226        struct property *pp = of_find_property(np, name, lenp);
 227
 228        return pp ? pp->value : NULL;
 229}
 230EXPORT_SYMBOL(of_get_property);
 231
 232/** Checks if the given "compat" string matches one of the strings in
 233 * the device's "compatible" property
 234 */
 235static int __of_device_is_compatible(const struct device_node *device,
 236                                     const char *compat)
 237{
 238        const char* cp;
 239        int cplen, l;
 240
 241        cp = __of_get_property(device, "compatible", &cplen);
 242        if (cp == NULL)
 243                return 0;
 244        while (cplen > 0) {
 245                if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
 246                        return 1;
 247                l = strlen(cp) + 1;
 248                cp += l;
 249                cplen -= l;
 250        }
 251
 252        return 0;
 253}
 254
 255/** Checks if the given "compat" string matches one of the strings in
 256 * the device's "compatible" property
 257 */
 258int of_device_is_compatible(const struct device_node *device,
 259                const char *compat)
 260{
 261        unsigned long flags;
 262        int res;
 263
 264        raw_spin_lock_irqsave(&devtree_lock, flags);
 265        res = __of_device_is_compatible(device, compat);
 266        raw_spin_unlock_irqrestore(&devtree_lock, flags);
 267        return res;
 268}
 269EXPORT_SYMBOL(of_device_is_compatible);
 270
 271/**
 272 * of_machine_is_compatible - Test root of device tree for a given compatible value
 273 * @compat: compatible string to look for in root node's compatible property.
 274 *
 275 * Returns true if the root node has the given value in its
 276 * compatible property.
 277 */
 278int of_machine_is_compatible(const char *compat)
 279{
 280        struct device_node *root;
 281        int rc = 0;
 282
 283        root = of_find_node_by_path("/");
 284        if (root) {
 285                rc = of_device_is_compatible(root, compat);
 286                of_node_put(root);
 287        }
 288        return rc;
 289}
 290EXPORT_SYMBOL(of_machine_is_compatible);
 291
 292/**
 293 *  __of_device_is_available - check if a device is available for use
 294 *
 295 *  @device: Node to check for availability, with locks already held
 296 *
 297 *  Returns 1 if the status property is absent or set to "okay" or "ok",
 298 *  0 otherwise
 299 */
 300static int __of_device_is_available(const struct device_node *device)
 301{
 302        const char *status;
 303        int statlen;
 304
 305        status = __of_get_property(device, "status", &statlen);
 306        if (status == NULL)
 307                return 1;
 308
 309        if (statlen > 0) {
 310                if (!strcmp(status, "okay") || !strcmp(status, "ok"))
 311                        return 1;
 312        }
 313
 314        return 0;
 315}
 316
 317/**
 318 *  of_device_is_available - check if a device is available for use
 319 *
 320 *  @device: Node to check for availability
 321 *
 322 *  Returns 1 if the status property is absent or set to "okay" or "ok",
 323 *  0 otherwise
 324 */
 325int of_device_is_available(const struct device_node *device)
 326{
 327        unsigned long flags;
 328        int res;
 329
 330        raw_spin_lock_irqsave(&devtree_lock, flags);
 331        res = __of_device_is_available(device);
 332        raw_spin_unlock_irqrestore(&devtree_lock, flags);
 333        return res;
 334
 335}
 336EXPORT_SYMBOL(of_device_is_available);
 337
 338/**
 339 *      of_get_parent - Get a node's parent if any
 340 *      @node:  Node to get parent
 341 *
 342 *      Returns a node pointer with refcount incremented, use
 343 *      of_node_put() on it when done.
 344 */
 345struct device_node *of_get_parent(const struct device_node *node)
 346{
 347        struct device_node *np;
 348        unsigned long flags;
 349
 350        if (!node)
 351                return NULL;
 352
 353        raw_spin_lock_irqsave(&devtree_lock, flags);
 354        np = of_node_get(node->parent);
 355        raw_spin_unlock_irqrestore(&devtree_lock, flags);
 356        return np;
 357}
 358EXPORT_SYMBOL(of_get_parent);
 359
 360/**
 361 *      of_get_next_parent - Iterate to a node's parent
 362 *      @node:  Node to get parent of
 363 *
 364 *      This is like of_get_parent() except that it drops the
 365 *      refcount on the passed node, making it suitable for iterating
 366 *      through a node's parents.
 367 *
 368 *      Returns a node pointer with refcount incremented, use
 369 *      of_node_put() on it when done.
 370 */
 371struct device_node *of_get_next_parent(struct device_node *node)
 372{
 373        struct device_node *parent;
 374        unsigned long flags;
 375
 376        if (!node)
 377                return NULL;
 378
 379        raw_spin_lock_irqsave(&devtree_lock, flags);
 380        parent = of_node_get(node->parent);
 381        of_node_put(node);
 382        raw_spin_unlock_irqrestore(&devtree_lock, flags);
 383        return parent;
 384}
 385
 386/**
 387 *      of_get_next_child - Iterate a node childs
 388 *      @node:  parent node
 389 *      @prev:  previous child of the parent node, or NULL to get first
 390 *
 391 *      Returns a node pointer with refcount incremented, use
 392 *      of_node_put() on it when done.
 393 */
 394struct device_node *of_get_next_child(const struct device_node *node,
 395        struct device_node *prev)
 396{
 397        struct device_node *next;
 398        unsigned long flags;
 399
 400        raw_spin_lock_irqsave(&devtree_lock, flags);
 401        next = prev ? prev->sibling : node->child;
 402        for (; next; next = next->sibling)
 403                if (of_node_get(next))
 404                        break;
 405        of_node_put(prev);
 406        raw_spin_unlock_irqrestore(&devtree_lock, flags);
 407        return next;
 408}
 409EXPORT_SYMBOL(of_get_next_child);
 410
 411/**
 412 *      of_get_next_available_child - Find the next available child node
 413 *      @node:  parent node
 414 *      @prev:  previous child of the parent node, or NULL to get first
 415 *
 416 *      This function is like of_get_next_child(), except that it
 417 *      automatically skips any disabled nodes (i.e. status = "disabled").
 418 */
 419struct device_node *of_get_next_available_child(const struct device_node *node,
 420        struct device_node *prev)
 421{
 422        struct device_node *next;
 423
 424        raw_spin_lock(&devtree_lock);
 425        next = prev ? prev->sibling : node->child;
 426        for (; next; next = next->sibling) {
 427                if (!__of_device_is_available(next))
 428                        continue;
 429                if (of_node_get(next))
 430                        break;
 431        }
 432        of_node_put(prev);
 433        raw_spin_unlock(&devtree_lock);
 434        return next;
 435}
 436EXPORT_SYMBOL(of_get_next_available_child);
 437
 438/**
 439 *      of_get_child_by_name - Find the child node by name for a given parent
 440 *      @node:  parent node
 441 *      @name:  child name to look for.
 442 *
 443 *      This function looks for child node for given matching name
 444 *
 445 *      Returns a node pointer if found, with refcount incremented, use
 446 *      of_node_put() on it when done.
 447 *      Returns NULL if node is not found.
 448 */
 449struct device_node *of_get_child_by_name(const struct device_node *node,
 450                                const char *name)
 451{
 452        struct device_node *child;
 453
 454        for_each_child_of_node(node, child)
 455                if (child->name && (of_node_cmp(child->name, name) == 0))
 456                        break;
 457        return child;
 458}
 459EXPORT_SYMBOL(of_get_child_by_name);
 460
 461/**
 462 *      of_find_node_by_path - Find a node matching a full OF path
 463 *      @path:  The full path to match
 464 *
 465 *      Returns a node pointer with refcount incremented, use
 466 *      of_node_put() on it when done.
 467 */
 468struct device_node *of_find_node_by_path(const char *path)
 469{
 470        struct device_node *np = of_allnodes;
 471        unsigned long flags;
 472
 473        raw_spin_lock_irqsave(&devtree_lock, flags);
 474        for (; np; np = np->allnext) {
 475                if (np->full_name && (of_node_cmp(np->full_name, path) == 0)
 476                    && of_node_get(np))
 477                        break;
 478        }
 479        raw_spin_unlock_irqrestore(&devtree_lock, flags);
 480        return np;
 481}
 482EXPORT_SYMBOL(of_find_node_by_path);
 483
 484/**
 485 *      of_find_node_by_name - Find a node by its "name" property
 486 *      @from:  The node to start searching from or NULL, the node
 487 *              you pass will not be searched, only the next one
 488 *              will; typically, you pass what the previous call
 489 *              returned. of_node_put() will be called on it
 490 *      @name:  The name string to match against
 491 *
 492 *      Returns a node pointer with refcount incremented, use
 493 *      of_node_put() on it when done.
 494 */
 495struct device_node *of_find_node_by_name(struct device_node *from,
 496        const char *name)
 497{
 498        struct device_node *np;
 499        unsigned long flags;
 500
 501        raw_spin_lock_irqsave(&devtree_lock, flags);
 502        np = from ? from->allnext : of_allnodes;
 503        for (; np; np = np->allnext)
 504                if (np->name && (of_node_cmp(np->name, name) == 0)
 505                    && of_node_get(np))
 506                        break;
 507        of_node_put(from);
 508        raw_spin_unlock_irqrestore(&devtree_lock, flags);
 509        return np;
 510}
 511EXPORT_SYMBOL(of_find_node_by_name);
 512
 513/**
 514 *      of_find_node_by_type - Find a node by its "device_type" property
 515 *      @from:  The node to start searching from, or NULL to start searching
 516 *              the entire device tree. The node you pass will not be
 517 *              searched, only the next one will; typically, you pass
 518 *              what the previous call returned. of_node_put() will be
 519 *              called on from for you.
 520 *      @type:  The type string to match against
 521 *
 522 *      Returns a node pointer with refcount incremented, use
 523 *      of_node_put() on it when done.
 524 */
 525struct device_node *of_find_node_by_type(struct device_node *from,
 526        const char *type)
 527{
 528        struct device_node *np;
 529        unsigned long flags;
 530
 531        raw_spin_lock_irqsave(&devtree_lock, flags);
 532        np = from ? from->allnext : of_allnodes;
 533        for (; np; np = np->allnext)
 534                if (np->type && (of_node_cmp(np->type, type) == 0)
 535                    && of_node_get(np))
 536                        break;
 537        of_node_put(from);
 538        raw_spin_unlock_irqrestore(&devtree_lock, flags);
 539        return np;
 540}
 541EXPORT_SYMBOL(of_find_node_by_type);
 542
 543/**
 544 *      of_find_compatible_node - Find a node based on type and one of the
 545 *                                tokens in its "compatible" property
 546 *      @from:          The node to start searching from or NULL, the node
 547 *                      you pass will not be searched, only the next one
 548 *                      will; typically, you pass what the previous call
 549 *                      returned. of_node_put() will be called on it
 550 *      @type:          The type string to match "device_type" or NULL to ignore
 551 *      @compatible:    The string to match to one of the tokens in the device
 552 *                      "compatible" list.
 553 *
 554 *      Returns a node pointer with refcount incremented, use
 555 *      of_node_put() on it when done.
 556 */
 557struct device_node *of_find_compatible_node(struct device_node *from,
 558        const char *type, const char *compatible)
 559{
 560        struct device_node *np;
 561        unsigned long flags;
 562
 563        raw_spin_lock_irqsave(&devtree_lock, flags);
 564        np = from ? from->allnext : of_allnodes;
 565        for (; np; np = np->allnext) {
 566                if (type
 567                    && !(np->type && (of_node_cmp(np->type, type) == 0)))
 568                        continue;
 569                if (__of_device_is_compatible(np, compatible) &&
 570                    of_node_get(np))
 571                        break;
 572        }
 573        of_node_put(from);
 574        raw_spin_unlock_irqrestore(&devtree_lock, flags);
 575        return np;
 576}
 577EXPORT_SYMBOL(of_find_compatible_node);
 578
 579/**
 580 *      of_find_node_with_property - Find a node which has a property with
 581 *                                   the given name.
 582 *      @from:          The node to start searching from or NULL, the node
 583 *                      you pass will not be searched, only the next one
 584 *                      will; typically, you pass what the previous call
 585 *                      returned. of_node_put() will be called on it
 586 *      @prop_name:     The name of the property to look for.
 587 *
 588 *      Returns a node pointer with refcount incremented, use
 589 *      of_node_put() on it when done.
 590 */
 591struct device_node *of_find_node_with_property(struct device_node *from,
 592        const char *prop_name)
 593{
 594        struct device_node *np;
 595        struct property *pp;
 596        unsigned long flags;
 597
 598        raw_spin_lock_irqsave(&devtree_lock, flags);
 599        np = from ? from->allnext : of_allnodes;
 600        for (; np; np = np->allnext) {
 601                for (pp = np->properties; pp; pp = pp->next) {
 602                        if (of_prop_cmp(pp->name, prop_name) == 0) {
 603                                of_node_get(np);
 604                                goto out;
 605                        }
 606                }
 607        }
 608out:
 609        of_node_put(from);
 610        raw_spin_unlock_irqrestore(&devtree_lock, flags);
 611        return np;
 612}
 613EXPORT_SYMBOL(of_find_node_with_property);
 614
 615static
 616const struct of_device_id *__of_match_node(const struct of_device_id *matches,
 617                                           const struct device_node *node)
 618{
 619        if (!matches)
 620                return NULL;
 621
 622        while (matches->name[0] || matches->type[0] || matches->compatible[0]) {
 623                int match = 1;
 624                if (matches->name[0])
 625                        match &= node->name
 626                                && !strcmp(matches->name, node->name);
 627                if (matches->type[0])
 628                        match &= node->type
 629                                && !strcmp(matches->type, node->type);
 630                if (matches->compatible[0])
 631                        match &= __of_device_is_compatible(node,
 632                                                           matches->compatible);
 633                if (match)
 634                        return matches;
 635                matches++;
 636        }
 637        return NULL;
 638}
 639
 640/**
 641 * of_match_node - Tell if an device_node has a matching of_match structure
 642 *      @matches:       array of of device match structures to search in
 643 *      @node:          the of device structure to match against
 644 *
 645 *      Low level utility function used by device matching.
 646 */
 647const struct of_device_id *of_match_node(const struct of_device_id *matches,
 648                                         const struct device_node *node)
 649{
 650        const struct of_device_id *match;
 651        unsigned long flags;
 652
 653        raw_spin_lock_irqsave(&devtree_lock, flags);
 654        match = __of_match_node(matches, node);
 655        raw_spin_unlock_irqrestore(&devtree_lock, flags);
 656        return match;
 657}
 658EXPORT_SYMBOL(of_match_node);
 659
 660/**
 661 *      of_find_matching_node_and_match - Find a node based on an of_device_id
 662 *                                        match table.
 663 *      @from:          The node to start searching from or NULL, the node
 664 *                      you pass will not be searched, only the next one
 665 *                      will; typically, you pass what the previous call
 666 *                      returned. of_node_put() will be called on it
 667 *      @matches:       array of of device match structures to search in
 668 *      @match          Updated to point at the matches entry which matched
 669 *
 670 *      Returns a node pointer with refcount incremented, use
 671 *      of_node_put() on it when done.
 672 */
 673struct device_node *of_find_matching_node_and_match(struct device_node *from,
 674                                        const struct of_device_id *matches,
 675                                        const struct of_device_id **match)
 676{
 677        struct device_node *np;
 678        const struct of_device_id *m;
 679        unsigned long flags;
 680
 681        if (match)
 682                *match = NULL;
 683
 684        raw_spin_lock_irqsave(&devtree_lock, flags);
 685        np = from ? from->allnext : of_allnodes;
 686        for (; np; np = np->allnext) {
 687                m = __of_match_node(matches, np);
 688                if (m && of_node_get(np)) {
 689                        if (match)
 690                                *match = m;
 691                        break;
 692                }
 693        }
 694        of_node_put(from);
 695        raw_spin_unlock_irqrestore(&devtree_lock, flags);
 696        return np;
 697}
 698EXPORT_SYMBOL(of_find_matching_node_and_match);
 699
 700/**
 701 * of_modalias_node - Lookup appropriate modalias for a device node
 702 * @node:       pointer to a device tree node
 703 * @modalias:   Pointer to buffer that modalias value will be copied into
 704 * @len:        Length of modalias value
 705 *
 706 * Based on the value of the compatible property, this routine will attempt
 707 * to choose an appropriate modalias value for a particular device tree node.
 708 * It does this by stripping the manufacturer prefix (as delimited by a ',')
 709 * from the first entry in the compatible list property.
 710 *
 711 * This routine returns 0 on success, <0 on failure.
 712 */
 713int of_modalias_node(struct device_node *node, char *modalias, int len)
 714{
 715        const char *compatible, *p;
 716        int cplen;
 717
 718        compatible = of_get_property(node, "compatible", &cplen);
 719        if (!compatible || strlen(compatible) > cplen)
 720                return -ENODEV;
 721        p = strchr(compatible, ',');
 722        strlcpy(modalias, p ? p + 1 : compatible, len);
 723        return 0;
 724}
 725EXPORT_SYMBOL_GPL(of_modalias_node);
 726
 727/**
 728 * of_find_node_by_phandle - Find a node given a phandle
 729 * @handle:     phandle of the node to find
 730 *
 731 * Returns a node pointer with refcount incremented, use
 732 * of_node_put() on it when done.
 733 */
 734struct device_node *of_find_node_by_phandle(phandle handle)
 735{
 736        struct device_node *np;
 737
 738        raw_spin_lock(&devtree_lock);
 739        for (np = of_allnodes; np; np = np->allnext)
 740                if (np->phandle == handle)
 741                        break;
 742        of_node_get(np);
 743        raw_spin_unlock(&devtree_lock);
 744        return np;
 745}
 746EXPORT_SYMBOL(of_find_node_by_phandle);
 747
 748/**
 749 * of_property_read_u8_array - Find and read an array of u8 from a property.
 750 *
 751 * @np:         device node from which the property value is to be read.
 752 * @propname:   name of the property to be searched.
 753 * @out_value:  pointer to return value, modified only if return value is 0.
 754 * @sz:         number of array elements to read
 755 *
 756 * Search for a property in a device node and read 8-bit value(s) from
 757 * it. Returns 0 on success, -EINVAL if the property does not exist,
 758 * -ENODATA if property does not have a value, and -EOVERFLOW if the
 759 * property data isn't large enough.
 760 *
 761 * dts entry of array should be like:
 762 *      property = /bits/ 8 <0x50 0x60 0x70>;
 763 *
 764 * The out_value is modified only if a valid u8 value can be decoded.
 765 */
 766int of_property_read_u8_array(const struct device_node *np,
 767                        const char *propname, u8 *out_values, size_t sz)
 768{
 769        struct property *prop = of_find_property(np, propname, NULL);
 770        const u8 *val;
 771
 772        if (!prop)
 773                return -EINVAL;
 774        if (!prop->value)
 775                return -ENODATA;
 776        if ((sz * sizeof(*out_values)) > prop->length)
 777                return -EOVERFLOW;
 778
 779        val = prop->value;
 780        while (sz--)
 781                *out_values++ = *val++;
 782        return 0;
 783}
 784EXPORT_SYMBOL_GPL(of_property_read_u8_array);
 785
 786/**
 787 * of_property_read_u16_array - Find and read an array of u16 from a property.
 788 *
 789 * @np:         device node from which the property value is to be read.
 790 * @propname:   name of the property to be searched.
 791 * @out_value:  pointer to return value, modified only if return value is 0.
 792 * @sz:         number of array elements to read
 793 *
 794 * Search for a property in a device node and read 16-bit value(s) from
 795 * it. Returns 0 on success, -EINVAL if the property does not exist,
 796 * -ENODATA if property does not have a value, and -EOVERFLOW if the
 797 * property data isn't large enough.
 798 *
 799 * dts entry of array should be like:
 800 *      property = /bits/ 16 <0x5000 0x6000 0x7000>;
 801 *
 802 * The out_value is modified only if a valid u16 value can be decoded.
 803 */
 804int of_property_read_u16_array(const struct device_node *np,
 805                        const char *propname, u16 *out_values, size_t sz)
 806{
 807        struct property *prop = of_find_property(np, propname, NULL);
 808        const __be16 *val;
 809
 810        if (!prop)
 811                return -EINVAL;
 812        if (!prop->value)
 813                return -ENODATA;
 814        if ((sz * sizeof(*out_values)) > prop->length)
 815                return -EOVERFLOW;
 816
 817        val = prop->value;
 818        while (sz--)
 819                *out_values++ = be16_to_cpup(val++);
 820        return 0;
 821}
 822EXPORT_SYMBOL_GPL(of_property_read_u16_array);
 823
 824/**
 825 * of_property_read_u32_array - Find and read an array of 32 bit integers
 826 * from a property.
 827 *
 828 * @np:         device node from which the property value is to be read.
 829 * @propname:   name of the property to be searched.
 830 * @out_value:  pointer to return value, modified only if return value is 0.
 831 * @sz:         number of array elements to read
 832 *
 833 * Search for a property in a device node and read 32-bit value(s) from
 834 * it. Returns 0 on success, -EINVAL if the property does not exist,
 835 * -ENODATA if property does not have a value, and -EOVERFLOW if the
 836 * property data isn't large enough.
 837 *
 838 * The out_value is modified only if a valid u32 value can be decoded.
 839 */
 840int of_property_read_u32_array(const struct device_node *np,
 841                               const char *propname, u32 *out_values,
 842                               size_t sz)
 843{
 844        struct property *prop = of_find_property(np, propname, NULL);
 845        const __be32 *val;
 846
 847        if (!prop)
 848                return -EINVAL;
 849        if (!prop->value)
 850                return -ENODATA;
 851        if ((sz * sizeof(*out_values)) > prop->length)
 852                return -EOVERFLOW;
 853
 854        val = prop->value;
 855        while (sz--)
 856                *out_values++ = be32_to_cpup(val++);
 857        return 0;
 858}
 859EXPORT_SYMBOL_GPL(of_property_read_u32_array);
 860
 861/**
 862 * of_property_read_u64 - Find and read a 64 bit integer from a property
 863 * @np:         device node from which the property value is to be read.
 864 * @propname:   name of the property to be searched.
 865 * @out_value:  pointer to return value, modified only if return value is 0.
 866 *
 867 * Search for a property in a device node and read a 64-bit value from
 868 * it. Returns 0 on success, -EINVAL if the property does not exist,
 869 * -ENODATA if property does not have a value, and -EOVERFLOW if the
 870 * property data isn't large enough.
 871 *
 872 * The out_value is modified only if a valid u64 value can be decoded.
 873 */
 874int of_property_read_u64(const struct device_node *np, const char *propname,
 875                         u64 *out_value)
 876{
 877        struct property *prop = of_find_property(np, propname, NULL);
 878
 879        if (!prop)
 880                return -EINVAL;
 881        if (!prop->value)
 882                return -ENODATA;
 883        if (sizeof(*out_value) > prop->length)
 884                return -EOVERFLOW;
 885        *out_value = of_read_number(prop->value, 2);
 886        return 0;
 887}
 888EXPORT_SYMBOL_GPL(of_property_read_u64);
 889
 890/**
 891 * of_property_read_string - Find and read a string from a property
 892 * @np:         device node from which the property value is to be read.
 893 * @propname:   name of the property to be searched.
 894 * @out_string: pointer to null terminated return string, modified only if
 895 *              return value is 0.
 896 *
 897 * Search for a property in a device tree node and retrieve a null
 898 * terminated string value (pointer to data, not a copy). Returns 0 on
 899 * success, -EINVAL if the property does not exist, -ENODATA if property
 900 * does not have a value, and -EILSEQ if the string is not null-terminated
 901 * within the length of the property data.
 902 *
 903 * The out_string pointer is modified only if a valid string can be decoded.
 904 */
 905int of_property_read_string(struct device_node *np, const char *propname,
 906                                const char **out_string)
 907{
 908        struct property *prop = of_find_property(np, propname, NULL);
 909        if (!prop)
 910                return -EINVAL;
 911        if (!prop->value)
 912                return -ENODATA;
 913        if (strnlen(prop->value, prop->length) >= prop->length)
 914                return -EILSEQ;
 915        *out_string = prop->value;
 916        return 0;
 917}
 918EXPORT_SYMBOL_GPL(of_property_read_string);
 919
 920/**
 921 * of_property_read_string_index - Find and read a string from a multiple
 922 * strings property.
 923 * @np:         device node from which the property value is to be read.
 924 * @propname:   name of the property to be searched.
 925 * @index:      index of the string in the list of strings
 926 * @out_string: pointer to null terminated return string, modified only if
 927 *              return value is 0.
 928 *
 929 * Search for a property in a device tree node and retrieve a null
 930 * terminated string value (pointer to data, not a copy) in the list of strings
 931 * contained in that property.
 932 * Returns 0 on success, -EINVAL if the property does not exist, -ENODATA if
 933 * property does not have a value, and -EILSEQ if the string is not
 934 * null-terminated within the length of the property data.
 935 *
 936 * The out_string pointer is modified only if a valid string can be decoded.
 937 */
 938int of_property_read_string_index(struct device_node *np, const char *propname,
 939                                  int index, const char **output)
 940{
 941        struct property *prop = of_find_property(np, propname, NULL);
 942        int i = 0;
 943        size_t l = 0, total = 0;
 944        const char *p;
 945
 946        if (!prop)
 947                return -EINVAL;
 948        if (!prop->value)
 949                return -ENODATA;
 950        if (strnlen(prop->value, prop->length) >= prop->length)
 951                return -EILSEQ;
 952
 953        p = prop->value;
 954
 955        for (i = 0; total < prop->length; total += l, p += l) {
 956                l = strlen(p) + 1;
 957                if (i++ == index) {
 958                        *output = p;
 959                        return 0;
 960                }
 961        }
 962        return -ENODATA;
 963}
 964EXPORT_SYMBOL_GPL(of_property_read_string_index);
 965
 966/**
 967 * of_property_match_string() - Find string in a list and return index
 968 * @np: pointer to node containing string list property
 969 * @propname: string list property name
 970 * @string: pointer to string to search for in string list
 971 *
 972 * This function searches a string list property and returns the index
 973 * of a specific string value.
 974 */
 975int of_property_match_string(struct device_node *np, const char *propname,
 976                             const char *string)
 977{
 978        struct property *prop = of_find_property(np, propname, NULL);
 979        size_t l;
 980        int i;
 981        const char *p, *end;
 982
 983        if (!prop)
 984                return -EINVAL;
 985        if (!prop->value)
 986                return -ENODATA;
 987
 988        p = prop->value;
 989        end = p + prop->length;
 990
 991        for (i = 0; p < end; i++, p += l) {
 992                l = strlen(p) + 1;
 993                if (p + l > end)
 994                        return -EILSEQ;
 995                pr_debug("comparing %s with %s\n", string, p);
 996                if (strcmp(string, p) == 0)
 997                        return i; /* Found it; return index */
 998        }
 999        return -ENODATA;
1000}
1001EXPORT_SYMBOL_GPL(of_property_match_string);
1002
1003/**
1004 * of_property_count_strings - Find and return the number of strings from a
1005 * multiple strings property.
1006 * @np:         device node from which the property value is to be read.
1007 * @propname:   name of the property to be searched.
1008 *
1009 * Search for a property in a device tree node and retrieve the number of null
1010 * terminated string contain in it. Returns the number of strings on
1011 * success, -EINVAL if the property does not exist, -ENODATA if property
1012 * does not have a value, and -EILSEQ if the string is not null-terminated
1013 * within the length of the property data.
1014 */
1015int of_property_count_strings(struct device_node *np, const char *propname)
1016{
1017        struct property *prop = of_find_property(np, propname, NULL);
1018        int i = 0;
1019        size_t l = 0, total = 0;
1020        const char *p;
1021
1022        if (!prop)
1023                return -EINVAL;
1024        if (!prop->value)
1025                return -ENODATA;
1026        if (strnlen(prop->value, prop->length) >= prop->length)
1027                return -EILSEQ;
1028
1029        p = prop->value;
1030
1031        for (i = 0; total < prop->length; total += l, p += l, i++)
1032                l = strlen(p) + 1;
1033
1034        return i;
1035}
1036EXPORT_SYMBOL_GPL(of_property_count_strings);
1037
1038/**
1039 * of_parse_phandle - Resolve a phandle property to a device_node pointer
1040 * @np: Pointer to device node holding phandle property
1041 * @phandle_name: Name of property holding a phandle value
1042 * @index: For properties holding a table of phandles, this is the index into
1043 *         the table
1044 *
1045 * Returns the device_node pointer with refcount incremented.  Use
1046 * of_node_put() on it when done.
1047 */
1048struct device_node *of_parse_phandle(const struct device_node *np,
1049                                     const char *phandle_name, int index)
1050{
1051        const __be32 *phandle;
1052        int size;
1053
1054        phandle = of_get_property(np, phandle_name, &size);
1055        if ((!phandle) || (size < sizeof(*phandle) * (index + 1)))
1056                return NULL;
1057
1058        return of_find_node_by_phandle(be32_to_cpup(phandle + index));
1059}
1060EXPORT_SYMBOL(of_parse_phandle);
1061
1062/**
1063 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
1064 * @np:         pointer to a device tree node containing a list
1065 * @list_name:  property name that contains a list
1066 * @cells_name: property name that specifies phandles' arguments count
1067 * @index:      index of a phandle to parse out
1068 * @out_args:   optional pointer to output arguments structure (will be filled)
1069 *
1070 * This function is useful to parse lists of phandles and their arguments.
1071 * Returns 0 on success and fills out_args, on error returns appropriate
1072 * errno value.
1073 *
1074 * Caller is responsible to call of_node_put() on the returned out_args->node
1075 * pointer.
1076 *
1077 * Example:
1078 *
1079 * phandle1: node1 {
1080 *      #list-cells = <2>;
1081 * }
1082 *
1083 * phandle2: node2 {
1084 *      #list-cells = <1>;
1085 * }
1086 *
1087 * node3 {
1088 *      list = <&phandle1 1 2 &phandle2 3>;
1089 * }
1090 *
1091 * To get a device_node of the `node2' node you may call this:
1092 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
1093 */
1094static int __of_parse_phandle_with_args(const struct device_node *np,
1095                                        const char *list_name,
1096                                        const char *cells_name, int index,
1097                                        struct of_phandle_args *out_args)
1098{
1099        const __be32 *list, *list_end;
1100        int rc = 0, size, cur_index = 0;
1101        uint32_t count = 0;
1102        struct device_node *node = NULL;
1103        phandle phandle;
1104
1105        /* Retrieve the phandle list property */
1106        list = of_get_property(np, list_name, &size);
1107        if (!list)
1108                return -ENOENT;
1109        list_end = list + size / sizeof(*list);
1110
1111        /* Loop over the phandles until all the requested entry is found */
1112        while (list < list_end) {
1113                rc = -EINVAL;
1114                count = 0;
1115
1116                /*
1117                 * If phandle is 0, then it is an empty entry with no
1118                 * arguments.  Skip forward to the next entry.
1119                 */
1120                phandle = be32_to_cpup(list++);
1121                if (phandle) {
1122                        /*
1123                         * Find the provider node and parse the #*-cells
1124                         * property to determine the argument length
1125                         */
1126                        node = of_find_node_by_phandle(phandle);
1127                        if (!node) {
1128                                pr_err("%s: could not find phandle\n",
1129                                         np->full_name);
1130                                goto err;
1131                        }
1132                        if (of_property_read_u32(node, cells_name, &count)) {
1133                                pr_err("%s: could not get %s for %s\n",
1134                                         np->full_name, cells_name,
1135                                         node->full_name);
1136                                goto err;
1137                        }
1138
1139                        /*
1140                         * Make sure that the arguments actually fit in the
1141                         * remaining property data length
1142                         */
1143                        if (list + count > list_end) {
1144                                pr_err("%s: arguments longer than property\n",
1145                                         np->full_name);
1146                                goto err;
1147                        }
1148                }
1149
1150                /*
1151                 * All of the error cases above bail out of the loop, so at
1152                 * this point, the parsing is successful. If the requested
1153                 * index matches, then fill the out_args structure and return,
1154                 * or return -ENOENT for an empty entry.
1155                 */
1156                rc = -ENOENT;
1157                if (cur_index == index) {
1158                        if (!phandle)
1159                                goto err;
1160
1161                        if (out_args) {
1162                                int i;
1163                                if (WARN_ON(count > MAX_PHANDLE_ARGS))
1164                                        count = MAX_PHANDLE_ARGS;
1165                                out_args->np = node;
1166                                out_args->args_count = count;
1167                                for (i = 0; i < count; i++)
1168                                        out_args->args[i] = be32_to_cpup(list++);
1169                        }
1170
1171                        /* Found it! return success */
1172                        if (node)
1173                                of_node_put(node);
1174                        return 0;
1175                }
1176
1177                of_node_put(node);
1178                node = NULL;
1179                list += count;
1180                cur_index++;
1181        }
1182
1183        /*
1184         * Unlock node before returning result; will be one of:
1185         * -ENOENT : index is for empty phandle
1186         * -EINVAL : parsing error on data
1187         * [1..n]  : Number of phandle (count mode; when index = -1)
1188         */
1189        rc = index < 0 ? cur_index : -ENOENT;
1190 err:
1191        if (node)
1192                of_node_put(node);
1193        return rc;
1194}
1195
1196int of_parse_phandle_with_args(const struct device_node *np, const char *list_name,
1197                                const char *cells_name, int index,
1198                                struct of_phandle_args *out_args)
1199{
1200        if (index < 0)
1201                return -EINVAL;
1202        return __of_parse_phandle_with_args(np, list_name, cells_name, index, out_args);
1203}
1204EXPORT_SYMBOL(of_parse_phandle_with_args);
1205
1206/**
1207 * of_count_phandle_with_args() - Find the number of phandles references in a property
1208 * @np:         pointer to a device tree node containing a list
1209 * @list_name:  property name that contains a list
1210 * @cells_name: property name that specifies phandles' arguments count
1211 *
1212 * Returns the number of phandle + argument tuples within a property. It
1213 * is a typical pattern to encode a list of phandle and variable
1214 * arguments into a single property. The number of arguments is encoded
1215 * by a property in the phandle-target node. For example, a gpios
1216 * property would contain a list of GPIO specifies consisting of a
1217 * phandle and 1 or more arguments. The number of arguments are
1218 * determined by the #gpio-cells property in the node pointed to by the
1219 * phandle.
1220 */
1221int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1222                                const char *cells_name)
1223{
1224        return __of_parse_phandle_with_args(np, list_name, cells_name, -1, NULL);
1225}
1226EXPORT_SYMBOL(of_count_phandle_with_args);
1227
1228#if defined(CONFIG_OF_DYNAMIC)
1229static int of_property_notify(int action, struct device_node *np,
1230                              struct property *prop)
1231{
1232        struct of_prop_reconfig pr;
1233
1234        pr.dn = np;
1235        pr.prop = prop;
1236        return of_reconfig_notify(action, &pr);
1237}
1238#else
1239static int of_property_notify(int action, struct device_node *np,
1240                              struct property *prop)
1241{
1242        return 0;
1243}
1244#endif
1245
1246/**
1247 * of_add_property - Add a property to a node
1248 */
1249int of_add_property(struct device_node *np, struct property *prop)
1250{
1251        struct property **next;
1252        unsigned long flags;
1253        int rc;
1254
1255        rc = of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop);
1256        if (rc)
1257                return rc;
1258
1259        prop->next = NULL;
1260        raw_spin_lock_irqsave(&devtree_lock, flags);
1261        next = &np->properties;
1262        while (*next) {
1263                if (strcmp(prop->name, (*next)->name) == 0) {
1264                        /* duplicate ! don't insert it */
1265                        raw_spin_unlock_irqrestore(&devtree_lock, flags);
1266                        return -1;
1267                }
1268                next = &(*next)->next;
1269        }
1270        *next = prop;
1271        raw_spin_unlock_irqrestore(&devtree_lock, flags);
1272
1273#ifdef CONFIG_PROC_DEVICETREE
1274        /* try to add to proc as well if it was initialized */
1275        if (np->pde)
1276                proc_device_tree_add_prop(np->pde, prop);
1277#endif /* CONFIG_PROC_DEVICETREE */
1278
1279        return 0;
1280}
1281
1282/**
1283 * of_remove_property - Remove a property from a node.
1284 *
1285 * Note that we don't actually remove it, since we have given out
1286 * who-knows-how-many pointers to the data using get-property.
1287 * Instead we just move the property to the "dead properties"
1288 * list, so it won't be found any more.
1289 */
1290int of_remove_property(struct device_node *np, struct property *prop)
1291{
1292        struct property **next;
1293        unsigned long flags;
1294        int found = 0;
1295        int rc;
1296
1297        rc = of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop);
1298        if (rc)
1299                return rc;
1300
1301        raw_spin_lock_irqsave(&devtree_lock, flags);
1302        next = &np->properties;
1303        while (*next) {
1304                if (*next == prop) {
1305                        /* found the node */
1306                        *next = prop->next;
1307                        prop->next = np->deadprops;
1308                        np->deadprops = prop;
1309                        found = 1;
1310                        break;
1311                }
1312                next = &(*next)->next;
1313        }
1314        raw_spin_unlock_irqrestore(&devtree_lock, flags);
1315
1316        if (!found)
1317                return -ENODEV;
1318
1319#ifdef CONFIG_PROC_DEVICETREE
1320        /* try to remove the proc node as well */
1321        if (np->pde)
1322                proc_device_tree_remove_prop(np->pde, prop);
1323#endif /* CONFIG_PROC_DEVICETREE */
1324
1325        return 0;
1326}
1327
1328/*
1329 * of_update_property - Update a property in a node, if the property does
1330 * not exist, add it.
1331 *
1332 * Note that we don't actually remove it, since we have given out
1333 * who-knows-how-many pointers to the data using get-property.
1334 * Instead we just move the property to the "dead properties" list,
1335 * and add the new property to the property list
1336 */
1337int of_update_property(struct device_node *np, struct property *newprop)
1338{
1339        struct property **next, *oldprop;
1340        unsigned long flags;
1341        int rc, found = 0;
1342
1343        rc = of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop);
1344        if (rc)
1345                return rc;
1346
1347        if (!newprop->name)
1348                return -EINVAL;
1349
1350        oldprop = of_find_property(np, newprop->name, NULL);
1351        if (!oldprop)
1352                return of_add_property(np, newprop);
1353
1354        raw_spin_lock_irqsave(&devtree_lock, flags);
1355        next = &np->properties;
1356        while (*next) {
1357                if (*next == oldprop) {
1358                        /* found the node */
1359                        newprop->next = oldprop->next;
1360                        *next = newprop;
1361                        oldprop->next = np->deadprops;
1362                        np->deadprops = oldprop;
1363                        found = 1;
1364                        break;
1365                }
1366                next = &(*next)->next;
1367        }
1368        raw_spin_unlock_irqrestore(&devtree_lock, flags);
1369
1370        if (!found)
1371                return -ENODEV;
1372
1373#ifdef CONFIG_PROC_DEVICETREE
1374        /* try to add to proc as well if it was initialized */
1375        if (np->pde)
1376                proc_device_tree_update_prop(np->pde, newprop, oldprop);
1377#endif /* CONFIG_PROC_DEVICETREE */
1378
1379        return 0;
1380}
1381
1382#if defined(CONFIG_OF_DYNAMIC)
1383/*
1384 * Support for dynamic device trees.
1385 *
1386 * On some platforms, the device tree can be manipulated at runtime.
1387 * The routines in this section support adding, removing and changing
1388 * device tree nodes.
1389 */
1390
1391static BLOCKING_NOTIFIER_HEAD(of_reconfig_chain);
1392
1393int of_reconfig_notifier_register(struct notifier_block *nb)
1394{
1395        return blocking_notifier_chain_register(&of_reconfig_chain, nb);
1396}
1397EXPORT_SYMBOL_GPL(of_reconfig_notifier_register);
1398
1399int of_reconfig_notifier_unregister(struct notifier_block *nb)
1400{
1401        return blocking_notifier_chain_unregister(&of_reconfig_chain, nb);
1402}
1403EXPORT_SYMBOL_GPL(of_reconfig_notifier_unregister);
1404
1405int of_reconfig_notify(unsigned long action, void *p)
1406{
1407        int rc;
1408
1409        rc = blocking_notifier_call_chain(&of_reconfig_chain, action, p);
1410        return notifier_to_errno(rc);
1411}
1412
1413#ifdef CONFIG_PROC_DEVICETREE
1414static void of_add_proc_dt_entry(struct device_node *dn)
1415{
1416        struct proc_dir_entry *ent;
1417
1418        ent = proc_mkdir(strrchr(dn->full_name, '/') + 1, dn->parent->pde);
1419        if (ent)
1420                proc_device_tree_add_node(dn, ent);
1421}
1422#else
1423static void of_add_proc_dt_entry(struct device_node *dn)
1424{
1425        return;
1426}
1427#endif
1428
1429/**
1430 * of_attach_node - Plug a device node into the tree and global list.
1431 */
1432int of_attach_node(struct device_node *np)
1433{
1434        unsigned long flags;
1435        int rc;
1436
1437        rc = of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, np);
1438        if (rc)
1439                return rc;
1440
1441        raw_spin_lock_irqsave(&devtree_lock, flags);
1442        np->sibling = np->parent->child;
1443        np->allnext = of_allnodes;
1444        np->parent->child = np;
1445        of_allnodes = np;
1446        raw_spin_unlock_irqrestore(&devtree_lock, flags);
1447
1448        of_add_proc_dt_entry(np);
1449        return 0;
1450}
1451
1452#ifdef CONFIG_PROC_DEVICETREE
1453static void of_remove_proc_dt_entry(struct device_node *dn)
1454{
1455        struct device_node *parent = dn->parent;
1456        struct property *prop = dn->properties;
1457
1458        while (prop) {
1459                remove_proc_entry(prop->name, dn->pde);
1460                prop = prop->next;
1461        }
1462
1463        if (dn->pde)
1464                remove_proc_entry(dn->pde->name, parent->pde);
1465}
1466#else
1467static void of_remove_proc_dt_entry(struct device_node *dn)
1468{
1469        return;
1470}
1471#endif
1472
1473/**
1474 * of_detach_node - "Unplug" a node from the device tree.
1475 *
1476 * The caller must hold a reference to the node.  The memory associated with
1477 * the node is not freed until its refcount goes to zero.
1478 */
1479int of_detach_node(struct device_node *np)
1480{
1481        struct device_node *parent;
1482        unsigned long flags;
1483        int rc = 0;
1484
1485        rc = of_reconfig_notify(OF_RECONFIG_DETACH_NODE, np);
1486        if (rc)
1487                return rc;
1488
1489        raw_spin_lock_irqsave(&devtree_lock, flags);
1490
1491        if (of_node_check_flag(np, OF_DETACHED)) {
1492                /* someone already detached it */
1493                raw_spin_unlock_irqrestore(&devtree_lock, flags);
1494                return rc;
1495        }
1496
1497        parent = np->parent;
1498        if (!parent) {
1499                raw_spin_unlock_irqrestore(&devtree_lock, flags);
1500                return rc;
1501        }
1502
1503        if (of_allnodes == np)
1504                of_allnodes = np->allnext;
1505        else {
1506                struct device_node *prev;
1507                for (prev = of_allnodes;
1508                     prev->allnext != np;
1509                     prev = prev->allnext)
1510                        ;
1511                prev->allnext = np->allnext;
1512        }
1513
1514        if (parent->child == np)
1515                parent->child = np->sibling;
1516        else {
1517                struct device_node *prevsib;
1518                for (prevsib = np->parent->child;
1519                     prevsib->sibling != np;
1520                     prevsib = prevsib->sibling)
1521                        ;
1522                prevsib->sibling = np->sibling;
1523        }
1524
1525        of_node_set_flag(np, OF_DETACHED);
1526        raw_spin_unlock_irqrestore(&devtree_lock, flags);
1527
1528        of_remove_proc_dt_entry(np);
1529        return rc;
1530}
1531#endif /* defined(CONFIG_OF_DYNAMIC) */
1532
1533static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1534                         int id, const char *stem, int stem_len)
1535{
1536        ap->np = np;
1537        ap->id = id;
1538        strncpy(ap->stem, stem, stem_len);
1539        ap->stem[stem_len] = 0;
1540        list_add_tail(&ap->link, &aliases_lookup);
1541        pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
1542                 ap->alias, ap->stem, ap->id, of_node_full_name(np));
1543}
1544
1545/**
1546 * of_alias_scan - Scan all properties of 'aliases' node
1547 *
1548 * The function scans all the properties of 'aliases' node and populate
1549 * the the global lookup table with the properties.  It returns the
1550 * number of alias_prop found, or error code in error case.
1551 *
1552 * @dt_alloc:   An allocator that provides a virtual address to memory
1553 *              for the resulting tree
1554 */
1555void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1556{
1557        struct property *pp;
1558
1559        of_chosen = of_find_node_by_path("/chosen");
1560        if (of_chosen == NULL)
1561                of_chosen = of_find_node_by_path("/chosen@0");
1562        of_aliases = of_find_node_by_path("/aliases");
1563        if (!of_aliases)
1564                return;
1565
1566        for_each_property_of_node(of_aliases, pp) {
1567                const char *start = pp->name;
1568                const char *end = start + strlen(start);
1569                struct device_node *np;
1570                struct alias_prop *ap;
1571                int id, len;
1572
1573                /* Skip those we do not want to proceed */
1574                if (!strcmp(pp->name, "name") ||
1575                    !strcmp(pp->name, "phandle") ||
1576                    !strcmp(pp->name, "linux,phandle"))
1577                        continue;
1578
1579                np = of_find_node_by_path(pp->value);
1580                if (!np)
1581                        continue;
1582
1583                /* walk the alias backwards to extract the id and work out
1584                 * the 'stem' string */
1585                while (isdigit(*(end-1)) && end > start)
1586                        end--;
1587                len = end - start;
1588
1589                if (kstrtoint(end, 10, &id) < 0)
1590                        continue;
1591
1592                /* Allocate an alias_prop with enough space for the stem */
1593                ap = dt_alloc(sizeof(*ap) + len + 1, 4);
1594                if (!ap)
1595                        continue;
1596                ap->alias = start;
1597                of_alias_add(ap, np, id, start, len);
1598        }
1599}
1600
1601/**
1602 * of_alias_get_id - Get alias id for the given device_node
1603 * @np:         Pointer to the given device_node
1604 * @stem:       Alias stem of the given device_node
1605 *
1606 * The function travels the lookup table to get alias id for the given
1607 * device_node and alias stem.  It returns the alias id if find it.
1608 */
1609int of_alias_get_id(struct device_node *np, const char *stem)
1610{
1611        struct alias_prop *app;
1612        int id = -ENODEV;
1613
1614        mutex_lock(&of_aliases_mutex);
1615        list_for_each_entry(app, &aliases_lookup, link) {
1616                if (strcmp(app->stem, stem) != 0)
1617                        continue;
1618
1619                if (np == app->np) {
1620                        id = app->id;
1621                        break;
1622                }
1623        }
1624        mutex_unlock(&of_aliases_mutex);
1625
1626        return id;
1627}
1628EXPORT_SYMBOL_GPL(of_alias_get_id);
1629
1630const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
1631                               u32 *pu)
1632{
1633        const void *curv = cur;
1634
1635        if (!prop)
1636                return NULL;
1637
1638        if (!cur) {
1639                curv = prop->value;
1640                goto out_val;
1641        }
1642
1643        curv += sizeof(*cur);
1644        if (curv >= prop->value + prop->length)
1645                return NULL;
1646
1647out_val:
1648        *pu = be32_to_cpup(curv);
1649        return curv;
1650}
1651EXPORT_SYMBOL_GPL(of_prop_next_u32);
1652
1653const char *of_prop_next_string(struct property *prop, const char *cur)
1654{
1655        const void *curv = cur;
1656
1657        if (!prop)
1658                return NULL;
1659
1660        if (!cur)
1661                return prop->value;
1662
1663        curv += strlen(cur) + 1;
1664        if (curv >= prop->value + prop->length)
1665                return NULL;
1666
1667        return curv;
1668}
1669EXPORT_SYMBOL_GPL(of_prop_next_string);
1670
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