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        unsigned long flags;
 196
 197        raw_spin_lock_irqsave(&devtree_lock, flags);
 198        np = prev ? prev->allnext : of_allnodes;
 199        for (; np != NULL; np = np->allnext)
 200                if (of_node_get(np))
 201                        break;
 202        of_node_put(prev);
 203        raw_spin_unlock_irqrestore(&devtree_lock, flags);
 204        return np;
 205}
 206EXPORT_SYMBOL(of_find_all_nodes);
 207
 208/*
 209 * Find a property with a given name for a given node
 210 * and return the value.
 211 */
 212static const void *__of_get_property(const struct device_node *np,
 213                                     const char *name, int *lenp)
 214{
 215        struct property *pp = __of_find_property(np, name, lenp);
 216
 217        return pp ? pp->value : NULL;
 218}
 219
 220/*
 221 * Find a property with a given name for a given node
 222 * and return the value.
 223 */
 224const void *of_get_property(const struct device_node *np, const char *name,
 225                            int *lenp)
 226{
 227        struct property *pp = of_find_property(np, name, lenp);
 228
 229        return pp ? pp->value : NULL;
 230}
 231EXPORT_SYMBOL(of_get_property);
 232
 233/** Checks if the given "compat" string matches one of the strings in
 234 * the device's "compatible" property
 235 */
 236static int __of_device_is_compatible(const struct device_node *device,
 237                                     const char *compat)
 238{
 239        const char* cp;
 240        int cplen, l;
 241
 242        cp = __of_get_property(device, "compatible", &cplen);
 243        if (cp == NULL)
 244                return 0;
 245        while (cplen > 0) {
 246                if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
 247                        return 1;
 248                l = strlen(cp) + 1;
 249                cp += l;
 250                cplen -= l;
 251        }
 252
 253        return 0;
 254}
 255
 256/** Checks if the given "compat" string matches one of the strings in
 257 * the device's "compatible" property
 258 */
 259int of_device_is_compatible(const struct device_node *device,
 260                const char *compat)
 261{
 262        unsigned long flags;
 263        int res;
 264
 265        raw_spin_lock_irqsave(&devtree_lock, flags);
 266        res = __of_device_is_compatible(device, compat);
 267        raw_spin_unlock_irqrestore(&devtree_lock, flags);
 268        return res;
 269}
 270EXPORT_SYMBOL(of_device_is_compatible);
 271
 272/**
 273 * of_machine_is_compatible - Test root of device tree for a given compatible value
 274 * @compat: compatible string to look for in root node's compatible property.
 275 *
 276 * Returns true if the root node has the given value in its
 277 * compatible property.
 278 */
 279int of_machine_is_compatible(const char *compat)
 280{
 281        struct device_node *root;
 282        int rc = 0;
 283
 284        root = of_find_node_by_path("/");
 285        if (root) {
 286                rc = of_device_is_compatible(root, compat);
 287                of_node_put(root);
 288        }
 289        return rc;
 290}
 291EXPORT_SYMBOL(of_machine_is_compatible);
 292
 293/**
 294 *  __of_device_is_available - check if a device is available for use
 295 *
 296 *  @device: Node to check for availability, with locks already held
 297 *
 298 *  Returns 1 if the status property is absent or set to "okay" or "ok",
 299 *  0 otherwise
 300 */
 301static int __of_device_is_available(const struct device_node *device)
 302{
 303        const char *status;
 304        int statlen;
 305
 306        status = __of_get_property(device, "status", &statlen);
 307        if (status == NULL)
 308                return 1;
 309
 310        if (statlen > 0) {
 311                if (!strcmp(status, "okay") || !strcmp(status, "ok"))
 312                        return 1;
 313        }
 314
 315        return 0;
 316}
 317
 318/**
 319 *  of_device_is_available - check if a device is available for use
 320 *
 321 *  @device: Node to check for availability
 322 *
 323 *  Returns 1 if the status property is absent or set to "okay" or "ok",
 324 *  0 otherwise
 325 */
 326int of_device_is_available(const struct device_node *device)
 327{
 328        unsigned long flags;
 329        int res;
 330
 331        raw_spin_lock_irqsave(&devtree_lock, flags);
 332        res = __of_device_is_available(device);
 333        raw_spin_unlock_irqrestore(&devtree_lock, flags);
 334        return res;
 335
 336}
 337EXPORT_SYMBOL(of_device_is_available);
 338
 339/**
 340 *      of_get_parent - Get a node's parent if any
 341 *      @node:  Node to get parent
 342 *
 343 *      Returns a node pointer with refcount incremented, use
 344 *      of_node_put() on it when done.
 345 */
 346struct device_node *of_get_parent(const struct device_node *node)
 347{
 348        struct device_node *np;
 349        unsigned long flags;
 350
 351        if (!node)
 352                return NULL;
 353
 354        raw_spin_lock_irqsave(&devtree_lock, flags);
 355        np = of_node_get(node->parent);
 356        raw_spin_unlock_irqrestore(&devtree_lock, flags);
 357        return np;
 358}
 359EXPORT_SYMBOL(of_get_parent);
 360
 361/**
 362 *      of_get_next_parent - Iterate to a node's parent
 363 *      @node:  Node to get parent of
 364 *
 365 *      This is like of_get_parent() except that it drops the
 366 *      refcount on the passed node, making it suitable for iterating
 367 *      through a node's parents.
 368 *
 369 *      Returns a node pointer with refcount incremented, use
 370 *      of_node_put() on it when done.
 371 */
 372struct device_node *of_get_next_parent(struct device_node *node)
 373{
 374        struct device_node *parent;
 375        unsigned long flags;
 376
 377        if (!node)
 378                return NULL;
 379
 380        raw_spin_lock_irqsave(&devtree_lock, flags);
 381        parent = of_node_get(node->parent);
 382        of_node_put(node);
 383        raw_spin_unlock_irqrestore(&devtree_lock, flags);
 384        return parent;
 385}
 386EXPORT_SYMBOL(of_get_next_parent);
 387
 388/**
 389 *      of_get_next_child - Iterate a node childs
 390 *      @node:  parent node
 391 *      @prev:  previous child of the parent node, or NULL to get first
 392 *
 393 *      Returns a node pointer with refcount incremented, use
 394 *      of_node_put() on it when done.
 395 */
 396struct device_node *of_get_next_child(const struct device_node *node,
 397        struct device_node *prev)
 398{
 399        struct device_node *next;
 400        unsigned long flags;
 401
 402        raw_spin_lock_irqsave(&devtree_lock, flags);
 403        next = prev ? prev->sibling : node->child;
 404        for (; next; next = next->sibling)
 405                if (of_node_get(next))
 406                        break;
 407        of_node_put(prev);
 408        raw_spin_unlock_irqrestore(&devtree_lock, flags);
 409        return next;
 410}
 411EXPORT_SYMBOL(of_get_next_child);
 412
 413/**
 414 *      of_get_next_available_child - Find the next available child node
 415 *      @node:  parent node
 416 *      @prev:  previous child of the parent node, or NULL to get first
 417 *
 418 *      This function is like of_get_next_child(), except that it
 419 *      automatically skips any disabled nodes (i.e. status = "disabled").
 420 */
 421struct device_node *of_get_next_available_child(const struct device_node *node,
 422        struct device_node *prev)
 423{
 424        struct device_node *next;
 425        unsigned long flags;
 426
 427        raw_spin_lock_irqsave(&devtree_lock, flags);
 428        next = prev ? prev->sibling : node->child;
 429        for (; next; next = next->sibling) {
 430                if (!__of_device_is_available(next))
 431                        continue;
 432                if (of_node_get(next))
 433                        break;
 434        }
 435        of_node_put(prev);
 436        raw_spin_unlock_irqrestore(&devtree_lock, flags);
 437        return next;
 438}
 439EXPORT_SYMBOL(of_get_next_available_child);
 440
 441/**
 442 *      of_get_child_by_name - Find the child node by name for a given parent
 443 *      @node:  parent node
 444 *      @name:  child name to look for.
 445 *
 446 *      This function looks for child node for given matching name
 447 *
 448 *      Returns a node pointer if found, with refcount incremented, use
 449 *      of_node_put() on it when done.
 450 *      Returns NULL if node is not found.
 451 */
 452struct device_node *of_get_child_by_name(const struct device_node *node,
 453                                const char *name)
 454{
 455        struct device_node *child;
 456
 457        for_each_child_of_node(node, child)
 458                if (child->name && (of_node_cmp(child->name, name) == 0))
 459                        break;
 460        return child;
 461}
 462EXPORT_SYMBOL(of_get_child_by_name);
 463
 464/**
 465 *      of_find_node_by_path - Find a node matching a full OF path
 466 *      @path:  The full path to match
 467 *
 468 *      Returns a node pointer with refcount incremented, use
 469 *      of_node_put() on it when done.
 470 */
 471struct device_node *of_find_node_by_path(const char *path)
 472{
 473        struct device_node *np = of_allnodes;
 474        unsigned long flags;
 475
 476        raw_spin_lock_irqsave(&devtree_lock, flags);
 477        for (; np; np = np->allnext) {
 478                if (np->full_name && (of_node_cmp(np->full_name, path) == 0)
 479                    && of_node_get(np))
 480                        break;
 481        }
 482        raw_spin_unlock_irqrestore(&devtree_lock, flags);
 483        return np;
 484}
 485EXPORT_SYMBOL(of_find_node_by_path);
 486
 487/**
 488 *      of_find_node_by_name - Find a node by its "name" property
 489 *      @from:  The node to start searching from or NULL, the node
 490 *              you pass will not be searched, only the next one
 491 *              will; typically, you pass what the previous call
 492 *              returned. of_node_put() will be called on it
 493 *      @name:  The name string to match against
 494 *
 495 *      Returns a node pointer with refcount incremented, use
 496 *      of_node_put() on it when done.
 497 */
 498struct device_node *of_find_node_by_name(struct device_node *from,
 499        const char *name)
 500{
 501        struct device_node *np;
 502        unsigned long flags;
 503
 504        raw_spin_lock_irqsave(&devtree_lock, flags);
 505        np = from ? from->allnext : of_allnodes;
 506        for (; np; np = np->allnext)
 507                if (np->name && (of_node_cmp(np->name, name) == 0)
 508                    && of_node_get(np))
 509                        break;
 510        of_node_put(from);
 511        raw_spin_unlock_irqrestore(&devtree_lock, flags);
 512        return np;
 513}
 514EXPORT_SYMBOL(of_find_node_by_name);
 515
 516/**
 517 *      of_find_node_by_type - Find a node by its "device_type" property
 518 *      @from:  The node to start searching from, or NULL to start searching
 519 *              the entire device tree. The node you pass will not be
 520 *              searched, only the next one will; typically, you pass
 521 *              what the previous call returned. of_node_put() will be
 522 *              called on from for you.
 523 *      @type:  The type string to match against
 524 *
 525 *      Returns a node pointer with refcount incremented, use
 526 *      of_node_put() on it when done.
 527 */
 528struct device_node *of_find_node_by_type(struct device_node *from,
 529        const char *type)
 530{
 531        struct device_node *np;
 532        unsigned long flags;
 533
 534        raw_spin_lock_irqsave(&devtree_lock, flags);
 535        np = from ? from->allnext : of_allnodes;
 536        for (; np; np = np->allnext)
 537                if (np->type && (of_node_cmp(np->type, type) == 0)
 538                    && of_node_get(np))
 539                        break;
 540        of_node_put(from);
 541        raw_spin_unlock_irqrestore(&devtree_lock, flags);
 542        return np;
 543}
 544EXPORT_SYMBOL(of_find_node_by_type);
 545
 546/**
 547 *      of_find_compatible_node - Find a node based on type and one of the
 548 *                                tokens in its "compatible" property
 549 *      @from:          The node to start searching from or NULL, the node
 550 *                      you pass will not be searched, only the next one
 551 *                      will; typically, you pass what the previous call
 552 *                      returned. of_node_put() will be called on it
 553 *      @type:          The type string to match "device_type" or NULL to ignore
 554 *      @compatible:    The string to match to one of the tokens in the device
 555 *                      "compatible" list.
 556 *
 557 *      Returns a node pointer with refcount incremented, use
 558 *      of_node_put() on it when done.
 559 */
 560struct device_node *of_find_compatible_node(struct device_node *from,
 561        const char *type, const char *compatible)
 562{
 563        struct device_node *np;
 564        unsigned long flags;
 565
 566        raw_spin_lock_irqsave(&devtree_lock, flags);
 567        np = from ? from->allnext : of_allnodes;
 568        for (; np; np = np->allnext) {
 569                if (type
 570                    && !(np->type && (of_node_cmp(np->type, type) == 0)))
 571                        continue;
 572                if (__of_device_is_compatible(np, compatible) &&
 573                    of_node_get(np))
 574                        break;
 575        }
 576        of_node_put(from);
 577        raw_spin_unlock_irqrestore(&devtree_lock, flags);
 578        return np;
 579}
 580EXPORT_SYMBOL(of_find_compatible_node);
 581
 582/**
 583 *      of_find_node_with_property - Find a node which has a property with
 584 *                                   the given name.
 585 *      @from:          The node to start searching from or NULL, the node
 586 *                      you pass will not be searched, only the next one
 587 *                      will; typically, you pass what the previous call
 588 *                      returned. of_node_put() will be called on it
 589 *      @prop_name:     The name of the property to look for.
 590 *
 591 *      Returns a node pointer with refcount incremented, use
 592 *      of_node_put() on it when done.
 593 */
 594struct device_node *of_find_node_with_property(struct device_node *from,
 595        const char *prop_name)
 596{
 597        struct device_node *np;
 598        struct property *pp;
 599        unsigned long flags;
 600
 601        raw_spin_lock_irqsave(&devtree_lock, flags);
 602        np = from ? from->allnext : of_allnodes;
 603        for (; np; np = np->allnext) {
 604                for (pp = np->properties; pp; pp = pp->next) {
 605                        if (of_prop_cmp(pp->name, prop_name) == 0) {
 606                                of_node_get(np);
 607                                goto out;
 608                        }
 609                }
 610        }
 611out:
 612        of_node_put(from);
 613        raw_spin_unlock_irqrestore(&devtree_lock, flags);
 614        return np;
 615}
 616EXPORT_SYMBOL(of_find_node_with_property);
 617
 618static
 619const struct of_device_id *__of_match_node(const struct of_device_id *matches,
 620                                           const struct device_node *node)
 621{
 622        if (!matches)
 623                return NULL;
 624
 625        while (matches->name[0] || matches->type[0] || matches->compatible[0]) {
 626                int match = 1;
 627                if (matches->name[0])
 628                        match &= node->name
 629                                && !strcmp(matches->name, node->name);
 630                if (matches->type[0])
 631                        match &= node->type
 632                                && !strcmp(matches->type, node->type);
 633                if (matches->compatible[0])
 634                        match &= __of_device_is_compatible(node,
 635                                                           matches->compatible);
 636                if (match)
 637                        return matches;
 638                matches++;
 639        }
 640        return NULL;
 641}
 642
 643/**
 644 * of_match_node - Tell if an device_node has a matching of_match structure
 645 *      @matches:       array of of device match structures to search in
 646 *      @node:          the of device structure to match against
 647 *
 648 *      Low level utility function used by device matching.
 649 */
 650const struct of_device_id *of_match_node(const struct of_device_id *matches,
 651                                         const struct device_node *node)
 652{
 653        const struct of_device_id *match;
 654        unsigned long flags;
 655
 656        raw_spin_lock_irqsave(&devtree_lock, flags);
 657        match = __of_match_node(matches, node);
 658        raw_spin_unlock_irqrestore(&devtree_lock, flags);
 659        return match;
 660}
 661EXPORT_SYMBOL(of_match_node);
 662
 663/**
 664 *      of_find_matching_node_and_match - Find a node based on an of_device_id
 665 *                                        match table.
 666 *      @from:          The node to start searching from or NULL, the node
 667 *                      you pass will not be searched, only the next one
 668 *                      will; typically, you pass what the previous call
 669 *                      returned. of_node_put() will be called on it
 670 *      @matches:       array of of device match structures to search in
 671 *      @match          Updated to point at the matches entry which matched
 672 *
 673 *      Returns a node pointer with refcount incremented, use
 674 *      of_node_put() on it when done.
 675 */
 676struct device_node *of_find_matching_node_and_match(struct device_node *from,
 677                                        const struct of_device_id *matches,
 678                                        const struct of_device_id **match)
 679{
 680        struct device_node *np;
 681        const struct of_device_id *m;
 682        unsigned long flags;
 683
 684        if (match)
 685                *match = NULL;
 686
 687        raw_spin_lock_irqsave(&devtree_lock, flags);
 688        np = from ? from->allnext : of_allnodes;
 689        for (; np; np = np->allnext) {
 690                m = __of_match_node(matches, np);
 691                if (m && of_node_get(np)) {
 692                        if (match)
 693                                *match = m;
 694                        break;
 695                }
 696        }
 697        of_node_put(from);
 698        raw_spin_unlock_irqrestore(&devtree_lock, flags);
 699        return np;
 700}
 701EXPORT_SYMBOL(of_find_matching_node_and_match);
 702
 703/**
 704 * of_modalias_node - Lookup appropriate modalias for a device node
 705 * @node:       pointer to a device tree node
 706 * @modalias:   Pointer to buffer that modalias value will be copied into
 707 * @len:        Length of modalias value
 708 *
 709 * Based on the value of the compatible property, this routine will attempt
 710 * to choose an appropriate modalias value for a particular device tree node.
 711 * It does this by stripping the manufacturer prefix (as delimited by a ',')
 712 * from the first entry in the compatible list property.
 713 *
 714 * This routine returns 0 on success, <0 on failure.
 715 */
 716int of_modalias_node(struct device_node *node, char *modalias, int len)
 717{
 718        const char *compatible, *p;
 719        int cplen;
 720
 721        compatible = of_get_property(node, "compatible", &cplen);
 722        if (!compatible || strlen(compatible) > cplen)
 723                return -ENODEV;
 724        p = strchr(compatible, ',');
 725        strlcpy(modalias, p ? p + 1 : compatible, len);
 726        return 0;
 727}
 728EXPORT_SYMBOL_GPL(of_modalias_node);
 729
 730/**
 731 * of_find_node_by_phandle - Find a node given a phandle
 732 * @handle:     phandle of the node to find
 733 *
 734 * Returns a node pointer with refcount incremented, use
 735 * of_node_put() on it when done.
 736 */
 737struct device_node *of_find_node_by_phandle(phandle handle)
 738{
 739        struct device_node *np;
 740        unsigned long flags;
 741
 742        raw_spin_lock_irqsave(&devtree_lock, flags);
 743        for (np = of_allnodes; np; np = np->allnext)
 744                if (np->phandle == handle)
 745                        break;
 746        of_node_get(np);
 747        raw_spin_unlock_irqrestore(&devtree_lock, flags);
 748        return np;
 749}
 750EXPORT_SYMBOL(of_find_node_by_phandle);
 751
 752/**
 753 * of_find_property_value_of_size
 754 *
 755 * @np:         device node from which the property value is to be read.
 756 * @propname:   name of the property to be searched.
 757 * @len:        requested length of property value
 758 *
 759 * Search for a property in a device node and valid the requested size.
 760 * Returns the property value on success, -EINVAL if the property does not
 761 *  exist, -ENODATA if property does not have a value, and -EOVERFLOW if the
 762 * property data isn't large enough.
 763 *
 764 */
 765static void *of_find_property_value_of_size(const struct device_node *np,
 766                        const char *propname, u32 len)
 767{
 768        struct property *prop = of_find_property(np, propname, NULL);
 769
 770        if (!prop)
 771                return ERR_PTR(-EINVAL);
 772        if (!prop->value)
 773                return ERR_PTR(-ENODATA);
 774        if (len > prop->length)
 775                return ERR_PTR(-EOVERFLOW);
 776
 777        return prop->value;
 778}
 779
 780/**
 781 * of_property_read_u32_index - Find and read a u32 from a multi-value property.
 782 *
 783 * @np:         device node from which the property value is to be read.
 784 * @propname:   name of the property to be searched.
 785 * @index:      index of the u32 in the list of values
 786 * @out_value:  pointer to return value, modified only if no error.
 787 *
 788 * Search for a property in a device node and read nth 32-bit value from
 789 * it. Returns 0 on success, -EINVAL if the property does not exist,
 790 * -ENODATA if property does not have a value, and -EOVERFLOW if the
 791 * property data isn't large enough.
 792 *
 793 * The out_value is modified only if a valid u32 value can be decoded.
 794 */
 795int of_property_read_u32_index(const struct device_node *np,
 796                                       const char *propname,
 797                                       u32 index, u32 *out_value)
 798{
 799        const u32 *val = of_find_property_value_of_size(np, propname,
 800                                        ((index + 1) * sizeof(*out_value)));
 801
 802        if (IS_ERR(val))
 803                return PTR_ERR(val);
 804
 805        *out_value = be32_to_cpup(((__be32 *)val) + index);
 806        return 0;
 807}
 808EXPORT_SYMBOL_GPL(of_property_read_u32_index);
 809
 810/**
 811 * of_property_read_u8_array - Find and read an array of u8 from a property.
 812 *
 813 * @np:         device node from which the property value is to be read.
 814 * @propname:   name of the property to be searched.
 815 * @out_value:  pointer to return value, modified only if return value is 0.
 816 * @sz:         number of array elements to read
 817 *
 818 * Search for a property in a device node and read 8-bit value(s) from
 819 * it. Returns 0 on success, -EINVAL if the property does not exist,
 820 * -ENODATA if property does not have a value, and -EOVERFLOW if the
 821 * property data isn't large enough.
 822 *
 823 * dts entry of array should be like:
 824 *      property = /bits/ 8 <0x50 0x60 0x70>;
 825 *
 826 * The out_value is modified only if a valid u8 value can be decoded.
 827 */
 828int of_property_read_u8_array(const struct device_node *np,
 829                        const char *propname, u8 *out_values, size_t sz)
 830{
 831        const u8 *val = of_find_property_value_of_size(np, propname,
 832                                                (sz * sizeof(*out_values)));
 833
 834        if (IS_ERR(val))
 835                return PTR_ERR(val);
 836
 837        while (sz--)
 838                *out_values++ = *val++;
 839        return 0;
 840}
 841EXPORT_SYMBOL_GPL(of_property_read_u8_array);
 842
 843/**
 844 * of_property_read_u16_array - Find and read an array of u16 from a property.
 845 *
 846 * @np:         device node from which the property value is to be read.
 847 * @propname:   name of the property to be searched.
 848 * @out_value:  pointer to return value, modified only if return value is 0.
 849 * @sz:         number of array elements to read
 850 *
 851 * Search for a property in a device node and read 16-bit value(s) from
 852 * it. Returns 0 on success, -EINVAL if the property does not exist,
 853 * -ENODATA if property does not have a value, and -EOVERFLOW if the
 854 * property data isn't large enough.
 855 *
 856 * dts entry of array should be like:
 857 *      property = /bits/ 16 <0x5000 0x6000 0x7000>;
 858 *
 859 * The out_value is modified only if a valid u16 value can be decoded.
 860 */
 861int of_property_read_u16_array(const struct device_node *np,
 862                        const char *propname, u16 *out_values, size_t sz)
 863{
 864        const __be16 *val = of_find_property_value_of_size(np, propname,
 865                                                (sz * sizeof(*out_values)));
 866
 867        if (IS_ERR(val))
 868                return PTR_ERR(val);
 869
 870        while (sz--)
 871                *out_values++ = be16_to_cpup(val++);
 872        return 0;
 873}
 874EXPORT_SYMBOL_GPL(of_property_read_u16_array);
 875
 876/**
 877 * of_property_read_u32_array - Find and read an array of 32 bit integers
 878 * from a property.
 879 *
 880 * @np:         device node from which the property value is to be read.
 881 * @propname:   name of the property to be searched.
 882 * @out_value:  pointer to return value, modified only if return value is 0.
 883 * @sz:         number of array elements to read
 884 *
 885 * Search for a property in a device node and read 32-bit value(s) from
 886 * it. Returns 0 on success, -EINVAL if the property does not exist,
 887 * -ENODATA if property does not have a value, and -EOVERFLOW if the
 888 * property data isn't large enough.
 889 *
 890 * The out_value is modified only if a valid u32 value can be decoded.
 891 */
 892int of_property_read_u32_array(const struct device_node *np,
 893                               const char *propname, u32 *out_values,
 894                               size_t sz)
 895{
 896        const __be32 *val = of_find_property_value_of_size(np, propname,
 897                                                (sz * sizeof(*out_values)));
 898
 899        if (IS_ERR(val))
 900                return PTR_ERR(val);
 901
 902        while (sz--)
 903                *out_values++ = be32_to_cpup(val++);
 904        return 0;
 905}
 906EXPORT_SYMBOL_GPL(of_property_read_u32_array);
 907
 908/**
 909 * of_property_read_u64 - Find and read a 64 bit integer from a property
 910 * @np:         device node from which the property value is to be read.
 911 * @propname:   name of the property to be searched.
 912 * @out_value:  pointer to return value, modified only if return value is 0.
 913 *
 914 * Search for a property in a device node and read a 64-bit value from
 915 * it. Returns 0 on success, -EINVAL if the property does not exist,
 916 * -ENODATA if property does not have a value, and -EOVERFLOW if the
 917 * property data isn't large enough.
 918 *
 919 * The out_value is modified only if a valid u64 value can be decoded.
 920 */
 921int of_property_read_u64(const struct device_node *np, const char *propname,
 922                         u64 *out_value)
 923{
 924        const __be32 *val = of_find_property_value_of_size(np, propname,
 925                                                sizeof(*out_value));
 926
 927        if (IS_ERR(val))
 928                return PTR_ERR(val);
 929
 930        *out_value = of_read_number(val, 2);
 931        return 0;
 932}
 933EXPORT_SYMBOL_GPL(of_property_read_u64);
 934
 935/**
 936 * of_property_read_string - Find and read a string from a property
 937 * @np:         device node from which the property value is to be read.
 938 * @propname:   name of the property to be searched.
 939 * @out_string: pointer to null terminated return string, modified only if
 940 *              return value is 0.
 941 *
 942 * Search for a property in a device tree node and retrieve a null
 943 * terminated string value (pointer to data, not a copy). Returns 0 on
 944 * success, -EINVAL if the property does not exist, -ENODATA if property
 945 * does not have a value, and -EILSEQ if the string is not null-terminated
 946 * within the length of the property data.
 947 *
 948 * The out_string pointer is modified only if a valid string can be decoded.
 949 */
 950int of_property_read_string(struct device_node *np, const char *propname,
 951                                const char **out_string)
 952{
 953        struct property *prop = of_find_property(np, propname, NULL);
 954        if (!prop)
 955                return -EINVAL;
 956        if (!prop->value)
 957                return -ENODATA;
 958        if (strnlen(prop->value, prop->length) >= prop->length)
 959                return -EILSEQ;
 960        *out_string = prop->value;
 961        return 0;
 962}
 963EXPORT_SYMBOL_GPL(of_property_read_string);
 964
 965/**
 966 * of_property_read_string_index - Find and read a string from a multiple
 967 * strings property.
 968 * @np:         device node from which the property value is to be read.
 969 * @propname:   name of the property to be searched.
 970 * @index:      index of the string in the list of strings
 971 * @out_string: pointer to null terminated return string, modified only if
 972 *              return value is 0.
 973 *
 974 * Search for a property in a device tree node and retrieve a null
 975 * terminated string value (pointer to data, not a copy) in the list of strings
 976 * contained in that property.
 977 * Returns 0 on success, -EINVAL if the property does not exist, -ENODATA if
 978 * property does not have a value, and -EILSEQ if the string is not
 979 * null-terminated within the length of the property data.
 980 *
 981 * The out_string pointer is modified only if a valid string can be decoded.
 982 */
 983int of_property_read_string_index(struct device_node *np, const char *propname,
 984                                  int index, const char **output)
 985{
 986        struct property *prop = of_find_property(np, propname, NULL);
 987        int i = 0;
 988        size_t l = 0, total = 0;
 989        const char *p;
 990
 991        if (!prop)
 992                return -EINVAL;
 993        if (!prop->value)
 994                return -ENODATA;
 995        if (strnlen(prop->value, prop->length) >= prop->length)
 996                return -EILSEQ;
 997
 998        p = prop->value;
 999
1000        for (i = 0; total < prop->length; total += l, p += l) {
1001                l = strlen(p) + 1;
1002                if (i++ == index) {
1003                        *output = p;
1004                        return 0;
1005                }
1006        }
1007        return -ENODATA;
1008}
1009EXPORT_SYMBOL_GPL(of_property_read_string_index);
1010
1011/**
1012 * of_property_match_string() - Find string in a list and return index
1013 * @np: pointer to node containing string list property
1014 * @propname: string list property name
1015 * @string: pointer to string to search for in string list
1016 *
1017 * This function searches a string list property and returns the index
1018 * of a specific string value.
1019 */
1020int of_property_match_string(struct device_node *np, const char *propname,
1021                             const char *string)
1022{
1023        struct property *prop = of_find_property(np, propname, NULL);
1024        size_t l;
1025        int i;
1026        const char *p, *end;
1027
1028        if (!prop)
1029                return -EINVAL;
1030        if (!prop->value)
1031                return -ENODATA;
1032
1033        p = prop->value;
1034        end = p + prop->length;
1035
1036        for (i = 0; p < end; i++, p += l) {
1037                l = strlen(p) + 1;
1038                if (p + l > end)
1039                        return -EILSEQ;
1040                pr_debug("comparing %s with %s\n", string, p);
1041                if (strcmp(string, p) == 0)
1042                        return i; /* Found it; return index */
1043        }
1044        return -ENODATA;
1045}
1046EXPORT_SYMBOL_GPL(of_property_match_string);
1047
1048/**
1049 * of_property_count_strings - Find and return the number of strings from a
1050 * multiple strings property.
1051 * @np:         device node from which the property value is to be read.
1052 * @propname:   name of the property to be searched.
1053 *
1054 * Search for a property in a device tree node and retrieve the number of null
1055 * terminated string contain in it. Returns the number of strings on
1056 * success, -EINVAL if the property does not exist, -ENODATA if property
1057 * does not have a value, and -EILSEQ if the string is not null-terminated
1058 * within the length of the property data.
1059 */
1060int of_property_count_strings(struct device_node *np, const char *propname)
1061{
1062        struct property *prop = of_find_property(np, propname, NULL);
1063        int i = 0;
1064        size_t l = 0, total = 0;
1065        const char *p;
1066
1067        if (!prop)
1068                return -EINVAL;
1069        if (!prop->value)
1070                return -ENODATA;
1071        if (strnlen(prop->value, prop->length) >= prop->length)
1072                return -EILSEQ;
1073
1074        p = prop->value;
1075
1076        for (i = 0; total < prop->length; total += l, p += l, i++)
1077                l = strlen(p) + 1;
1078
1079        return i;
1080}
1081EXPORT_SYMBOL_GPL(of_property_count_strings);
1082
1083/**
1084 * of_parse_phandle - Resolve a phandle property to a device_node pointer
1085 * @np: Pointer to device node holding phandle property
1086 * @phandle_name: Name of property holding a phandle value
1087 * @index: For properties holding a table of phandles, this is the index into
1088 *         the table
1089 *
1090 * Returns the device_node pointer with refcount incremented.  Use
1091 * of_node_put() on it when done.
1092 */
1093struct device_node *of_parse_phandle(const struct device_node *np,
1094                                     const char *phandle_name, int index)
1095{
1096        const __be32 *phandle;
1097        int size;
1098
1099        phandle = of_get_property(np, phandle_name, &size);
1100        if ((!phandle) || (size < sizeof(*phandle) * (index + 1)))
1101                return NULL;
1102
1103        return of_find_node_by_phandle(be32_to_cpup(phandle + index));
1104}
1105EXPORT_SYMBOL(of_parse_phandle);
1106
1107/**
1108 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
1109 * @np:         pointer to a device tree node containing a list
1110 * @list_name:  property name that contains a list
1111 * @cells_name: property name that specifies phandles' arguments count
1112 * @index:      index of a phandle to parse out
1113 * @out_args:   optional pointer to output arguments structure (will be filled)
1114 *
1115 * This function is useful to parse lists of phandles and their arguments.
1116 * Returns 0 on success and fills out_args, on error returns appropriate
1117 * errno value.
1118 *
1119 * Caller is responsible to call of_node_put() on the returned out_args->node
1120 * pointer.
1121 *
1122 * Example:
1123 *
1124 * phandle1: node1 {
1125 *      #list-cells = <2>;
1126 * }
1127 *
1128 * phandle2: node2 {
1129 *      #list-cells = <1>;
1130 * }
1131 *
1132 * node3 {
1133 *      list = <&phandle1 1 2 &phandle2 3>;
1134 * }
1135 *
1136 * To get a device_node of the `node2' node you may call this:
1137 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
1138 */
1139static int __of_parse_phandle_with_args(const struct device_node *np,
1140                                        const char *list_name,
1141                                        const char *cells_name, int index,
1142                                        struct of_phandle_args *out_args)
1143{
1144        const __be32 *list, *list_end;
1145        int rc = 0, size, cur_index = 0;
1146        uint32_t count = 0;
1147        struct device_node *node = NULL;
1148        phandle phandle;
1149
1150        /* Retrieve the phandle list property */
1151        list = of_get_property(np, list_name, &size);
1152        if (!list)
1153                return -ENOENT;
1154        list_end = list + size / sizeof(*list);
1155
1156        /* Loop over the phandles until all the requested entry is found */
1157        while (list < list_end) {
1158                rc = -EINVAL;
1159                count = 0;
1160
1161                /*
1162                 * If phandle is 0, then it is an empty entry with no
1163                 * arguments.  Skip forward to the next entry.
1164                 */
1165                phandle = be32_to_cpup(list++);
1166                if (phandle) {
1167                        /*
1168                         * Find the provider node and parse the #*-cells
1169                         * property to determine the argument length
1170                         */
1171                        node = of_find_node_by_phandle(phandle);
1172                        if (!node) {
1173                                pr_err("%s: could not find phandle\n",
1174                                         np->full_name);
1175                                goto err;
1176                        }
1177                        if (of_property_read_u32(node, cells_name, &count)) {
1178                                pr_err("%s: could not get %s for %s\n",
1179                                         np->full_name, cells_name,
1180                                         node->full_name);
1181                                goto err;
1182                        }
1183
1184                        /*
1185                         * Make sure that the arguments actually fit in the
1186                         * remaining property data length
1187                         */
1188                        if (list + count > list_end) {
1189                                pr_err("%s: arguments longer than property\n",
1190                                         np->full_name);
1191                                goto err;
1192                        }
1193                }
1194
1195                /*
1196                 * All of the error cases above bail out of the loop, so at
1197                 * this point, the parsing is successful. If the requested
1198                 * index matches, then fill the out_args structure and return,
1199                 * or return -ENOENT for an empty entry.
1200                 */
1201                rc = -ENOENT;
1202                if (cur_index == index) {
1203                        if (!phandle)
1204                                goto err;
1205
1206                        if (out_args) {
1207                                int i;
1208                                if (WARN_ON(count > MAX_PHANDLE_ARGS))
1209                                        count = MAX_PHANDLE_ARGS;
1210                                out_args->np = node;
1211                                out_args->args_count = count;
1212                                for (i = 0; i < count; i++)
1213                                        out_args->args[i] = be32_to_cpup(list++);
1214                        } else {
1215                                of_node_put(node);
1216                        }
1217
1218                        /* Found it! return success */
1219                        return 0;
1220                }
1221
1222                of_node_put(node);
1223                node = NULL;
1224                list += count;
1225                cur_index++;
1226        }
1227
1228        /*
1229         * Unlock node before returning result; will be one of:
1230         * -ENOENT : index is for empty phandle
1231         * -EINVAL : parsing error on data
1232         * [1..n]  : Number of phandle (count mode; when index = -1)
1233         */
1234        rc = index < 0 ? cur_index : -ENOENT;
1235 err:
1236        if (node)
1237                of_node_put(node);
1238        return rc;
1239}
1240
1241int of_parse_phandle_with_args(const struct device_node *np, const char *list_name,
1242                                const char *cells_name, int index,
1243                                struct of_phandle_args *out_args)
1244{
1245        if (index < 0)
1246                return -EINVAL;
1247        return __of_parse_phandle_with_args(np, list_name, cells_name, index, out_args);
1248}
1249EXPORT_SYMBOL(of_parse_phandle_with_args);
1250
1251/**
1252 * of_count_phandle_with_args() - Find the number of phandles references in a property
1253 * @np:         pointer to a device tree node containing a list
1254 * @list_name:  property name that contains a list
1255 * @cells_name: property name that specifies phandles' arguments count
1256 *
1257 * Returns the number of phandle + argument tuples within a property. It
1258 * is a typical pattern to encode a list of phandle and variable
1259 * arguments into a single property. The number of arguments is encoded
1260 * by a property in the phandle-target node. For example, a gpios
1261 * property would contain a list of GPIO specifies consisting of a
1262 * phandle and 1 or more arguments. The number of arguments are
1263 * determined by the #gpio-cells property in the node pointed to by the
1264 * phandle.
1265 */
1266int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1267                                const char *cells_name)
1268{
1269        return __of_parse_phandle_with_args(np, list_name, cells_name, -1, NULL);
1270}
1271EXPORT_SYMBOL(of_count_phandle_with_args);
1272
1273#if defined(CONFIG_OF_DYNAMIC)
1274static int of_property_notify(int action, struct device_node *np,
1275                              struct property *prop)
1276{
1277        struct of_prop_reconfig pr;
1278
1279        pr.dn = np;
1280        pr.prop = prop;
1281        return of_reconfig_notify(action, &pr);
1282}
1283#else
1284static int of_property_notify(int action, struct device_node *np,
1285                              struct property *prop)
1286{
1287        return 0;
1288}
1289#endif
1290
1291/**
1292 * of_add_property - Add a property to a node
1293 */
1294int of_add_property(struct device_node *np, struct property *prop)
1295{
1296        struct property **next;
1297        unsigned long flags;
1298        int rc;
1299
1300        rc = of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop);
1301        if (rc)
1302                return rc;
1303
1304        prop->next = NULL;
1305        raw_spin_lock_irqsave(&devtree_lock, flags);
1306        next = &np->properties;
1307        while (*next) {
1308                if (strcmp(prop->name, (*next)->name) == 0) {
1309                        /* duplicate ! don't insert it */
1310                        raw_spin_unlock_irqrestore(&devtree_lock, flags);
1311                        return -1;
1312                }
1313                next = &(*next)->next;
1314        }
1315        *next = prop;
1316        raw_spin_unlock_irqrestore(&devtree_lock, flags);
1317
1318#ifdef CONFIG_PROC_DEVICETREE
1319        /* try to add to proc as well if it was initialized */
1320        if (np->pde)
1321                proc_device_tree_add_prop(np->pde, prop);
1322#endif /* CONFIG_PROC_DEVICETREE */
1323
1324        return 0;
1325}
1326
1327/**
1328 * of_remove_property - Remove a property from a node.
1329 *
1330 * Note that we don't actually remove it, since we have given out
1331 * who-knows-how-many pointers to the data using get-property.
1332 * Instead we just move the property to the "dead properties"
1333 * list, so it won't be found any more.
1334 */
1335int of_remove_property(struct device_node *np, struct property *prop)
1336{
1337        struct property **next;
1338        unsigned long flags;
1339        int found = 0;
1340        int rc;
1341
1342        rc = of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop);
1343        if (rc)
1344                return rc;
1345
1346        raw_spin_lock_irqsave(&devtree_lock, flags);
1347        next = &np->properties;
1348        while (*next) {
1349                if (*next == prop) {
1350                        /* found the node */
1351                        *next = prop->next;
1352                        prop->next = np->deadprops;
1353                        np->deadprops = prop;
1354                        found = 1;
1355                        break;
1356                }
1357                next = &(*next)->next;
1358        }
1359        raw_spin_unlock_irqrestore(&devtree_lock, flags);
1360
1361        if (!found)
1362                return -ENODEV;
1363
1364#ifdef CONFIG_PROC_DEVICETREE
1365        /* try to remove the proc node as well */
1366        if (np->pde)
1367                proc_device_tree_remove_prop(np->pde, prop);
1368#endif /* CONFIG_PROC_DEVICETREE */
1369
1370        return 0;
1371}
1372
1373/*
1374 * of_update_property - Update a property in a node, if the property does
1375 * not exist, add it.
1376 *
1377 * Note that we don't actually remove it, since we have given out
1378 * who-knows-how-many pointers to the data using get-property.
1379 * Instead we just move the property to the "dead properties" list,
1380 * and add the new property to the property list
1381 */
1382int of_update_property(struct device_node *np, struct property *newprop)
1383{
1384        struct property **next, *oldprop;
1385        unsigned long flags;
1386        int rc, found = 0;
1387
1388        rc = of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop);
1389        if (rc)
1390                return rc;
1391
1392        if (!newprop->name)
1393                return -EINVAL;
1394
1395        oldprop = of_find_property(np, newprop->name, NULL);
1396        if (!oldprop)
1397                return of_add_property(np, newprop);
1398
1399        raw_spin_lock_irqsave(&devtree_lock, flags);
1400        next = &np->properties;
1401        while (*next) {
1402                if (*next == oldprop) {
1403                        /* found the node */
1404                        newprop->next = oldprop->next;
1405                        *next = newprop;
1406                        oldprop->next = np->deadprops;
1407                        np->deadprops = oldprop;
1408                        found = 1;
1409                        break;
1410                }
1411                next = &(*next)->next;
1412        }
1413        raw_spin_unlock_irqrestore(&devtree_lock, flags);
1414
1415        if (!found)
1416                return -ENODEV;
1417
1418#ifdef CONFIG_PROC_DEVICETREE
1419        /* try to add to proc as well if it was initialized */
1420        if (np->pde)
1421                proc_device_tree_update_prop(np->pde, newprop, oldprop);
1422#endif /* CONFIG_PROC_DEVICETREE */
1423
1424        return 0;
1425}
1426
1427#if defined(CONFIG_OF_DYNAMIC)
1428/*
1429 * Support for dynamic device trees.
1430 *
1431 * On some platforms, the device tree can be manipulated at runtime.
1432 * The routines in this section support adding, removing and changing
1433 * device tree nodes.
1434 */
1435
1436static BLOCKING_NOTIFIER_HEAD(of_reconfig_chain);
1437
1438int of_reconfig_notifier_register(struct notifier_block *nb)
1439{
1440        return blocking_notifier_chain_register(&of_reconfig_chain, nb);
1441}
1442EXPORT_SYMBOL_GPL(of_reconfig_notifier_register);
1443
1444int of_reconfig_notifier_unregister(struct notifier_block *nb)
1445{
1446        return blocking_notifier_chain_unregister(&of_reconfig_chain, nb);
1447}
1448EXPORT_SYMBOL_GPL(of_reconfig_notifier_unregister);
1449
1450int of_reconfig_notify(unsigned long action, void *p)
1451{
1452        int rc;
1453
1454        rc = blocking_notifier_call_chain(&of_reconfig_chain, action, p);
1455        return notifier_to_errno(rc);
1456}
1457
1458#ifdef CONFIG_PROC_DEVICETREE
1459static void of_add_proc_dt_entry(struct device_node *dn)
1460{
1461        struct proc_dir_entry *ent;
1462
1463        ent = proc_mkdir(strrchr(dn->full_name, '/') + 1, dn->parent->pde);
1464        if (ent)
1465                proc_device_tree_add_node(dn, ent);
1466}
1467#else
1468static void of_add_proc_dt_entry(struct device_node *dn)
1469{
1470        return;
1471}
1472#endif
1473
1474/**
1475 * of_attach_node - Plug a device node into the tree and global list.
1476 */
1477int of_attach_node(struct device_node *np)
1478{
1479        unsigned long flags;
1480        int rc;
1481
1482        rc = of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, np);
1483        if (rc)
1484                return rc;
1485
1486        raw_spin_lock_irqsave(&devtree_lock, flags);
1487        np->sibling = np->parent->child;
1488        np->allnext = of_allnodes;
1489        np->parent->child = np;
1490        of_allnodes = np;
1491        raw_spin_unlock_irqrestore(&devtree_lock, flags);
1492
1493        of_add_proc_dt_entry(np);
1494        return 0;
1495}
1496
1497#ifdef CONFIG_PROC_DEVICETREE
1498static void of_remove_proc_dt_entry(struct device_node *dn)
1499{
1500        proc_remove(dn->pde);
1501}
1502#else
1503static void of_remove_proc_dt_entry(struct device_node *dn)
1504{
1505        return;
1506}
1507#endif
1508
1509/**
1510 * of_detach_node - "Unplug" a node from the device tree.
1511 *
1512 * The caller must hold a reference to the node.  The memory associated with
1513 * the node is not freed until its refcount goes to zero.
1514 */
1515int of_detach_node(struct device_node *np)
1516{
1517        struct device_node *parent;
1518        unsigned long flags;
1519        int rc = 0;
1520
1521        rc = of_reconfig_notify(OF_RECONFIG_DETACH_NODE, np);
1522        if (rc)
1523                return rc;
1524
1525        raw_spin_lock_irqsave(&devtree_lock, flags);
1526
1527        if (of_node_check_flag(np, OF_DETACHED)) {
1528                /* someone already detached it */
1529                raw_spin_unlock_irqrestore(&devtree_lock, flags);
1530                return rc;
1531        }
1532
1533        parent = np->parent;
1534        if (!parent) {
1535                raw_spin_unlock_irqrestore(&devtree_lock, flags);
1536                return rc;
1537        }
1538
1539        if (of_allnodes == np)
1540                of_allnodes = np->allnext;
1541        else {
1542                struct device_node *prev;
1543                for (prev = of_allnodes;
1544                     prev->allnext != np;
1545                     prev = prev->allnext)
1546                        ;
1547                prev->allnext = np->allnext;
1548        }
1549
1550        if (parent->child == np)
1551                parent->child = np->sibling;
1552        else {
1553                struct device_node *prevsib;
1554                for (prevsib = np->parent->child;
1555                     prevsib->sibling != np;
1556                     prevsib = prevsib->sibling)
1557                        ;
1558                prevsib->sibling = np->sibling;
1559        }
1560
1561        of_node_set_flag(np, OF_DETACHED);
1562        raw_spin_unlock_irqrestore(&devtree_lock, flags);
1563
1564        of_remove_proc_dt_entry(np);
1565        return rc;
1566}
1567#endif /* defined(CONFIG_OF_DYNAMIC) */
1568
1569static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1570                         int id, const char *stem, int stem_len)
1571{
1572        ap->np = np;
1573        ap->id = id;
1574        strncpy(ap->stem, stem, stem_len);
1575        ap->stem[stem_len] = 0;
1576        list_add_tail(&ap->link, &aliases_lookup);
1577        pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
1578                 ap->alias, ap->stem, ap->id, of_node_full_name(np));
1579}
1580
1581/**
1582 * of_alias_scan - Scan all properties of 'aliases' node
1583 *
1584 * The function scans all the properties of 'aliases' node and populate
1585 * the the global lookup table with the properties.  It returns the
1586 * number of alias_prop found, or error code in error case.
1587 *
1588 * @dt_alloc:   An allocator that provides a virtual address to memory
1589 *              for the resulting tree
1590 */
1591void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1592{
1593        struct property *pp;
1594
1595        of_chosen = of_find_node_by_path("/chosen");
1596        if (of_chosen == NULL)
1597                of_chosen = of_find_node_by_path("/chosen@0");
1598        of_aliases = of_find_node_by_path("/aliases");
1599        if (!of_aliases)
1600                return;
1601
1602        for_each_property_of_node(of_aliases, pp) {
1603                const char *start = pp->name;
1604                const char *end = start + strlen(start);
1605                struct device_node *np;
1606                struct alias_prop *ap;
1607                int id, len;
1608
1609                /* Skip those we do not want to proceed */
1610                if (!strcmp(pp->name, "name") ||
1611                    !strcmp(pp->name, "phandle") ||
1612                    !strcmp(pp->name, "linux,phandle"))
1613                        continue;
1614
1615                np = of_find_node_by_path(pp->value);
1616                if (!np)
1617                        continue;
1618
1619                /* walk the alias backwards to extract the id and work out
1620                 * the 'stem' string */
1621                while (isdigit(*(end-1)) && end > start)
1622                        end--;
1623                len = end - start;
1624
1625                if (kstrtoint(end, 10, &id) < 0)
1626                        continue;
1627
1628                /* Allocate an alias_prop with enough space for the stem */
1629                ap = dt_alloc(sizeof(*ap) + len + 1, 4);
1630                if (!ap)
1631                        continue;
1632                ap->alias = start;
1633                of_alias_add(ap, np, id, start, len);
1634        }
1635}
1636
1637/**
1638 * of_alias_get_id - Get alias id for the given device_node
1639 * @np:         Pointer to the given device_node
1640 * @stem:       Alias stem of the given device_node
1641 *
1642 * The function travels the lookup table to get alias id for the given
1643 * device_node and alias stem.  It returns the alias id if find it.
1644 */
1645int of_alias_get_id(struct device_node *np, const char *stem)
1646{
1647        struct alias_prop *app;
1648        int id = -ENODEV;
1649
1650        mutex_lock(&of_aliases_mutex);
1651        list_for_each_entry(app, &aliases_lookup, link) {
1652                if (strcmp(app->stem, stem) != 0)
1653                        continue;
1654
1655                if (np == app->np) {
1656                        id = app->id;
1657                        break;
1658                }
1659        }
1660        mutex_unlock(&of_aliases_mutex);
1661
1662        return id;
1663}
1664EXPORT_SYMBOL_GPL(of_alias_get_id);
1665
1666const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
1667                               u32 *pu)
1668{
1669        const void *curv = cur;
1670
1671        if (!prop)
1672                return NULL;
1673
1674        if (!cur) {
1675                curv = prop->value;
1676                goto out_val;
1677        }
1678
1679        curv += sizeof(*cur);
1680        if (curv >= prop->value + prop->length)
1681                return NULL;
1682
1683out_val:
1684        *pu = be32_to_cpup(curv);
1685        return curv;
1686}
1687EXPORT_SYMBOL_GPL(of_prop_next_u32);
1688
1689const char *of_prop_next_string(struct property *prop, const char *cur)
1690{
1691        const void *curv = cur;
1692
1693        if (!prop)
1694                return NULL;
1695
1696        if (!cur)
1697                return prop->value;
1698
1699        curv += strlen(cur) + 1;
1700        if (curv >= prop->value + prop->length)
1701                return NULL;
1702
1703        return curv;
1704}
1705EXPORT_SYMBOL_GPL(of_prop_next_string);
1706
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