1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * Procedures for creating, accessing and interpreting the device tree.
   4 *
   5 * Paul Mackerras	August 1996.
   6 * Copyright (C) 1996-2005 Paul Mackerras.
   7 *
   8 *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
   9 *    {engebret|bergner}@us.ibm.com
  10 *
  11 *  Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
  12 *
  13 *  Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
  14 *  Grant Likely.
  15 */
  16
  17#define pr_fmt(fmt)	"OF: " fmt
  18
  19#include <linux/cleanup.h>
  20#include <linux/console.h>
  21#include <linux/ctype.h>
  22#include <linux/cpu.h>
  23#include <linux/module.h>
  24#include <linux/of.h>
  25#include <linux/of_device.h>
  26#include <linux/of_graph.h>
  27#include <linux/spinlock.h>
  28#include <linux/slab.h>
  29#include <linux/string.h>
  30#include <linux/proc_fs.h>
  31
  32#include "of_private.h"
  33
  34LIST_HEAD(aliases_lookup);
  35
  36struct device_node *of_root;
  37EXPORT_SYMBOL(of_root);
  38struct device_node *of_chosen;
  39EXPORT_SYMBOL(of_chosen);
  40struct device_node *of_aliases;
  41struct device_node *of_stdout;
  42static const char *of_stdout_options;
  43
  44struct kset *of_kset;
  45
  46/*
  47 * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
  48 * This mutex must be held whenever modifications are being made to the
  49 * device tree. The of_{attach,detach}_node() and
  50 * of_{add,remove,update}_property() helpers make sure this happens.
  51 */
  52DEFINE_MUTEX(of_mutex);
  53
  54/* use when traversing tree through the child, sibling,
  55 * or parent members of struct device_node.
  56 */
  57DEFINE_RAW_SPINLOCK(devtree_lock);
  58
  59bool of_node_name_eq(const struct device_node *np, const char *name)
  60{
  61	const char *node_name;
  62	size_t len;
  63
  64	if (!np)
  65		return false;
  66
  67	node_name = kbasename(np->full_name);
  68	len = strchrnul(node_name, '@') - node_name;
  69
  70	return (strlen(name) == len) && (strncmp(node_name, name, len) == 0);
  71}
  72EXPORT_SYMBOL(of_node_name_eq);
  73
  74bool of_node_name_prefix(const struct device_node *np, const char *prefix)
  75{
  76	if (!np)
  77		return false;
  78
  79	return strncmp(kbasename(np->full_name), prefix, strlen(prefix)) == 0;
  80}
  81EXPORT_SYMBOL(of_node_name_prefix);
  82
  83static bool __of_node_is_type(const struct device_node *np, const char *type)
  84{
  85	const char *match = __of_get_property(np, "device_type", NULL);
  86
  87	return np && match && type && !strcmp(match, type);
  88}
  89
  90#define EXCLUDED_DEFAULT_CELLS_PLATFORMS ( \
  91	IS_ENABLED(CONFIG_SPARC) || \
  92	of_find_compatible_node(NULL, NULL, "coreboot") \
  93)
  94
  95int of_bus_n_addr_cells(struct device_node *np)
  96{
  97	u32 cells;
  98
  99	for (; np; np = np->parent) {
 100		if (!of_property_read_u32(np, "#address-cells", &cells))
 101			return cells;
 102		/*
 103		 * Default root value and walking parent nodes for "#address-cells"
 104		 * is deprecated. Any platforms which hit this warning should
 105		 * be added to the excluded list.
 106		 */
 107		WARN_ONCE(!EXCLUDED_DEFAULT_CELLS_PLATFORMS,
 108			  "Missing '#address-cells' in %pOF\n", np);
 109	}
 110	return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
 111}
 112
 113int of_n_addr_cells(struct device_node *np)
 114{
 115	if (np->parent)
 116		np = np->parent;
 117
 118	return of_bus_n_addr_cells(np);
 119}
 120EXPORT_SYMBOL(of_n_addr_cells);
 121
 122int of_bus_n_size_cells(struct device_node *np)
 123{
 124	u32 cells;
 125
 126	for (; np; np = np->parent) {
 127		if (!of_property_read_u32(np, "#size-cells", &cells))
 128			return cells;
 129		/*
 130		 * Default root value and walking parent nodes for "#size-cells"
 131		 * is deprecated. Any platforms which hit this warning should
 132		 * be added to the excluded list.
 133		 */
 134		WARN_ONCE(!EXCLUDED_DEFAULT_CELLS_PLATFORMS,
 135			  "Missing '#size-cells' in %pOF\n", np);
 136	}
 137	return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
 138}
 139
 140int of_n_size_cells(struct device_node *np)
 141{
 142	if (np->parent)
 143		np = np->parent;
 144
 145	return of_bus_n_size_cells(np);
 146}
 147EXPORT_SYMBOL(of_n_size_cells);
 148
 149#ifdef CONFIG_NUMA
 150int __weak of_node_to_nid(struct device_node *np)
 151{
 152	return NUMA_NO_NODE;
 153}
 154#endif
 155
 156#define OF_PHANDLE_CACHE_BITS	7
 157#define OF_PHANDLE_CACHE_SZ	BIT(OF_PHANDLE_CACHE_BITS)
 158
 159static struct device_node *phandle_cache[OF_PHANDLE_CACHE_SZ];
 160
 161static u32 of_phandle_cache_hash(phandle handle)
 162{
 163	return hash_32(handle, OF_PHANDLE_CACHE_BITS);
 164}
 165
 166/*
 167 * Caller must hold devtree_lock.
 168 */
 169void __of_phandle_cache_inv_entry(phandle handle)
 170{
 171	u32 handle_hash;
 172	struct device_node *np;
 173
 174	if (!handle)
 175		return;
 176
 177	handle_hash = of_phandle_cache_hash(handle);
 178
 179	np = phandle_cache[handle_hash];
 180	if (np && handle == np->phandle)
 181		phandle_cache[handle_hash] = NULL;
 182}
 183
 184void __init of_core_init(void)
 185{
 186	struct device_node *np;
 187
 188	of_platform_register_reconfig_notifier();
 189
 190	/* Create the kset, and register existing nodes */
 191	mutex_lock(&of_mutex);
 192	of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
 193	if (!of_kset) {
 194		mutex_unlock(&of_mutex);
 195		pr_err("failed to register existing nodes\n");
 196		return;
 197	}
 198	for_each_of_allnodes(np) {
 199		__of_attach_node_sysfs(np);
 200		if (np->phandle && !phandle_cache[of_phandle_cache_hash(np->phandle)])
 201			phandle_cache[of_phandle_cache_hash(np->phandle)] = np;
 202	}
 203	mutex_unlock(&of_mutex);
 204
 205	/* Symlink in /proc as required by userspace ABI */
 206	if (of_root)
 207		proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
 208}
 209
 210static struct property *__of_find_property(const struct device_node *np,
 211					   const char *name, int *lenp)
 212{
 213	struct property *pp;
 214
 215	if (!np)
 216		return NULL;
 217
 218	for (pp = np->properties; pp; pp = pp->next) {
 219		if (of_prop_cmp(pp->name, name) == 0) {
 220			if (lenp)
 221				*lenp = pp->length;
 222			break;
 223		}
 224	}
 225
 226	return pp;
 227}
 228
 229struct property *of_find_property(const struct device_node *np,
 230				  const char *name,
 231				  int *lenp)
 232{
 233	struct property *pp;
 234	unsigned long flags;
 235
 236	raw_spin_lock_irqsave(&devtree_lock, flags);
 237	pp = __of_find_property(np, name, lenp);
 238	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 239
 240	return pp;
 241}
 242EXPORT_SYMBOL(of_find_property);
 243
 244struct device_node *__of_find_all_nodes(struct device_node *prev)
 245{
 246	struct device_node *np;
 247	if (!prev) {
 248		np = of_root;
 249	} else if (prev->child) {
 250		np = prev->child;
 251	} else {
 252		/* Walk back up looking for a sibling, or the end of the structure */
 253		np = prev;
 254		while (np->parent && !np->sibling)
 255			np = np->parent;
 256		np = np->sibling; /* Might be null at the end of the tree */
 257	}
 258	return np;
 259}
 260
 261/**
 262 * of_find_all_nodes - Get next node in global list
 263 * @prev:	Previous node or NULL to start iteration
 264 *		of_node_put() will be called on it
 265 *
 266 * Return: A node pointer with refcount incremented, use
 267 * of_node_put() on it when done.
 268 */
 269struct device_node *of_find_all_nodes(struct device_node *prev)
 270{
 271	struct device_node *np;
 272	unsigned long flags;
 273
 274	raw_spin_lock_irqsave(&devtree_lock, flags);
 275	np = __of_find_all_nodes(prev);
 276	of_node_get(np);
 277	of_node_put(prev);
 278	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 279	return np;
 280}
 281EXPORT_SYMBOL(of_find_all_nodes);
 282
 283/*
 284 * Find a property with a given name for a given node
 285 * and return the value.
 286 */
 287const void *__of_get_property(const struct device_node *np,
 288			      const char *name, int *lenp)
 289{
 290	const struct property *pp = __of_find_property(np, name, lenp);
 291
 292	return pp ? pp->value : NULL;
 293}
 294
 295/*
 296 * Find a property with a given name for a given node
 297 * and return the value.
 298 */
 299const void *of_get_property(const struct device_node *np, const char *name,
 300			    int *lenp)
 301{
 302	const struct property *pp = of_find_property(np, name, lenp);
 303
 304	return pp ? pp->value : NULL;
 305}
 306EXPORT_SYMBOL(of_get_property);
 307
 308/**
 309 * __of_device_is_compatible() - Check if the node matches given constraints
 310 * @device: pointer to node
 311 * @compat: required compatible string, NULL or "" for any match
 312 * @type: required device_type value, NULL or "" for any match
 313 * @name: required node name, NULL or "" for any match
 314 *
 315 * Checks if the given @compat, @type and @name strings match the
 316 * properties of the given @device. A constraints can be skipped by
 317 * passing NULL or an empty string as the constraint.
 318 *
 319 * Returns 0 for no match, and a positive integer on match. The return
 320 * value is a relative score with larger values indicating better
 321 * matches. The score is weighted for the most specific compatible value
 322 * to get the highest score. Matching type is next, followed by matching
 323 * name. Practically speaking, this results in the following priority
 324 * order for matches:
 325 *
 326 * 1. specific compatible && type && name
 327 * 2. specific compatible && type
 328 * 3. specific compatible && name
 329 * 4. specific compatible
 330 * 5. general compatible && type && name
 331 * 6. general compatible && type
 332 * 7. general compatible && name
 333 * 8. general compatible
 334 * 9. type && name
 335 * 10. type
 336 * 11. name
 337 */
 338static int __of_device_is_compatible(const struct device_node *device,
 339				     const char *compat, const char *type, const char *name)
 340{
 341	const struct property *prop;
 342	const char *cp;
 343	int index = 0, score = 0;
 344
 345	/* Compatible match has highest priority */
 346	if (compat && compat[0]) {
 347		prop = __of_find_property(device, "compatible", NULL);
 348		for (cp = of_prop_next_string(prop, NULL); cp;
 349		     cp = of_prop_next_string(prop, cp), index++) {
 350			if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
 351				score = INT_MAX/2 - (index << 2);
 352				break;
 353			}
 354		}
 355		if (!score)
 356			return 0;
 357	}
 358
 359	/* Matching type is better than matching name */
 360	if (type && type[0]) {
 361		if (!__of_node_is_type(device, type))
 362			return 0;
 363		score += 2;
 364	}
 365
 366	/* Matching name is a bit better than not */
 367	if (name && name[0]) {
 368		if (!of_node_name_eq(device, name))
 369			return 0;
 370		score++;
 371	}
 372
 373	return score;
 374}
 375
 376/** Checks if the given "compat" string matches one of the strings in
 377 * the device's "compatible" property
 378 */
 379int of_device_is_compatible(const struct device_node *device,
 380		const char *compat)
 381{
 382	unsigned long flags;
 383	int res;
 384
 385	raw_spin_lock_irqsave(&devtree_lock, flags);
 386	res = __of_device_is_compatible(device, compat, NULL, NULL);
 387	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 388	return res;
 389}
 390EXPORT_SYMBOL(of_device_is_compatible);
 391
 392/** Checks if the device is compatible with any of the entries in
 393 *  a NULL terminated array of strings. Returns the best match
 394 *  score or 0.
 395 */
 396int of_device_compatible_match(const struct device_node *device,
 397			       const char *const *compat)
 398{
 399	unsigned int tmp, score = 0;
 400
 401	if (!compat)
 402		return 0;
 403
 404	while (*compat) {
 405		tmp = of_device_is_compatible(device, *compat);
 406		if (tmp > score)
 407			score = tmp;
 408		compat++;
 409	}
 410
 411	return score;
 412}
 413EXPORT_SYMBOL_GPL(of_device_compatible_match);
 414
 415/**
 416 * of_machine_compatible_match - Test root of device tree against a compatible array
 417 * @compats: NULL terminated array of compatible strings to look for in root node's compatible property.
 418 *
 419 * Returns true if the root node has any of the given compatible values in its
 420 * compatible property.
 421 */
 422bool of_machine_compatible_match(const char *const *compats)
 423{
 424	struct device_node *root;
 425	int rc = 0;
 426
 427	root = of_find_node_by_path("/");
 428	if (root) {
 429		rc = of_device_compatible_match(root, compats);
 430		of_node_put(root);
 431	}
 432
 433	return rc != 0;
 434}
 435EXPORT_SYMBOL(of_machine_compatible_match);
 436
 437static bool __of_device_is_status(const struct device_node *device,
 438				  const char * const*strings)
 439{
 440	const char *status;
 441	int statlen;
 442
 443	if (!device)
 444		return false;
 445
 446	status = __of_get_property(device, "status", &statlen);
 447	if (status == NULL)
 448		return false;
 449
 450	if (statlen > 0) {
 451		while (*strings) {
 452			unsigned int len = strlen(*strings);
 453
 454			if ((*strings)[len - 1] == '-') {
 455				if (!strncmp(status, *strings, len))
 456					return true;
 457			} else {
 458				if (!strcmp(status, *strings))
 459					return true;
 460			}
 461			strings++;
 462		}
 463	}
 464
 465	return false;
 466}
 
 467
 468/**
 469 *  __of_device_is_available - check if a device is available for use
 470 *
 471 *  @device: Node to check for availability, with locks already held
 472 *
 473 *  Return: True if the status property is absent or set to "okay" or "ok",
 474 *  false otherwise
 475 */
 476static bool __of_device_is_available(const struct device_node *device)
 477{
 478	static const char * const ok[] = {"okay", "ok", NULL};
 
 479
 480	if (!device)
 481		return false;
 482
 483	return !__of_get_property(device, "status", NULL) ||
 484		__of_device_is_status(device, ok);
 485}
 486
 487/**
 488 *  __of_device_is_reserved - check if a device is reserved
 489 *
 490 *  @device: Node to check for availability, with locks already held
 491 *
 492 *  Return: True if the status property is set to "reserved", false otherwise
 493 */
 494static bool __of_device_is_reserved(const struct device_node *device)
 495{
 496	static const char * const reserved[] = {"reserved", NULL};
 497
 498	return __of_device_is_status(device, reserved);
 499}
 500
 501/**
 502 *  of_device_is_available - check if a device is available for use
 503 *
 504 *  @device: Node to check for availability
 505 *
 506 *  Return: True if the status property is absent or set to "okay" or "ok",
 507 *  false otherwise
 508 */
 509bool of_device_is_available(const struct device_node *device)
 510{
 511	unsigned long flags;
 512	bool res;
 513
 514	raw_spin_lock_irqsave(&devtree_lock, flags);
 515	res = __of_device_is_available(device);
 516	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 517	return res;
 518
 519}
 520EXPORT_SYMBOL(of_device_is_available);
 521
 522/**
 523 *  __of_device_is_fail - check if a device has status "fail" or "fail-..."
 524 *
 525 *  @device: Node to check status for, with locks already held
 526 *
 527 *  Return: True if the status property is set to "fail" or "fail-..." (for any
 528 *  error code suffix), false otherwise
 529 */
 530static bool __of_device_is_fail(const struct device_node *device)
 531{
 532	static const char * const fail[] = {"fail", "fail-", NULL};
 
 
 
 533
 534	return __of_device_is_status(device, fail);
 
 
 
 
 535}
 536
 537/**
 538 *  of_device_is_big_endian - check if a device has BE registers
 539 *
 540 *  @device: Node to check for endianness
 541 *
 542 *  Return: True if the device has a "big-endian" property, or if the kernel
 543 *  was compiled for BE *and* the device has a "native-endian" property.
 544 *  Returns false otherwise.
 545 *
 546 *  Callers would nominally use ioread32be/iowrite32be if
 547 *  of_device_is_big_endian() == true, or readl/writel otherwise.
 548 */
 549bool of_device_is_big_endian(const struct device_node *device)
 550{
 551	if (of_property_read_bool(device, "big-endian"))
 552		return true;
 553	if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
 554	    of_property_read_bool(device, "native-endian"))
 555		return true;
 556	return false;
 557}
 558EXPORT_SYMBOL(of_device_is_big_endian);
 559
 560/**
 561 * of_get_parent - Get a node's parent if any
 562 * @node:	Node to get parent
 563 *
 564 * Return: A node pointer with refcount incremented, use
 565 * of_node_put() on it when done.
 566 */
 567struct device_node *of_get_parent(const struct device_node *node)
 568{
 569	struct device_node *np;
 570	unsigned long flags;
 571
 572	if (!node)
 573		return NULL;
 574
 575	raw_spin_lock_irqsave(&devtree_lock, flags);
 576	np = of_node_get(node->parent);
 577	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 578	return np;
 579}
 580EXPORT_SYMBOL(of_get_parent);
 581
 582/**
 583 * of_get_next_parent - Iterate to a node's parent
 584 * @node:	Node to get parent of
 585 *
 586 * This is like of_get_parent() except that it drops the
 587 * refcount on the passed node, making it suitable for iterating
 588 * through a node's parents.
 589 *
 590 * Return: A node pointer with refcount incremented, use
 591 * of_node_put() on it when done.
 592 */
 593struct device_node *of_get_next_parent(struct device_node *node)
 594{
 595	struct device_node *parent;
 596	unsigned long flags;
 597
 598	if (!node)
 599		return NULL;
 600
 601	raw_spin_lock_irqsave(&devtree_lock, flags);
 602	parent = of_node_get(node->parent);
 603	of_node_put(node);
 604	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 605	return parent;
 606}
 607EXPORT_SYMBOL(of_get_next_parent);
 608
 609static struct device_node *__of_get_next_child(const struct device_node *node,
 610						struct device_node *prev)
 611{
 612	struct device_node *next;
 613
 614	if (!node)
 615		return NULL;
 616
 617	next = prev ? prev->sibling : node->child;
 618	of_node_get(next);
 619	of_node_put(prev);
 620	return next;
 621}
 622#define __for_each_child_of_node(parent, child) \
 623	for (child = __of_get_next_child(parent, NULL); child != NULL; \
 624	     child = __of_get_next_child(parent, child))
 625
 626/**
 627 * of_get_next_child - Iterate a node childs
 628 * @node:	parent node
 629 * @prev:	previous child of the parent node, or NULL to get first
 630 *
 631 * Return: A node pointer with refcount incremented, use of_node_put() on
 632 * it when done. Returns NULL when prev is the last child. Decrements the
 633 * refcount of prev.
 634 */
 635struct device_node *of_get_next_child(const struct device_node *node,
 636	struct device_node *prev)
 637{
 638	struct device_node *next;
 639	unsigned long flags;
 640
 641	raw_spin_lock_irqsave(&devtree_lock, flags);
 642	next = __of_get_next_child(node, prev);
 643	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 644	return next;
 645}
 646EXPORT_SYMBOL(of_get_next_child);
 647
 648/**
 649 * of_get_next_child_with_prefix - Find the next child node with prefix
 650 * @node:	parent node
 651 * @prev:	previous child of the parent node, or NULL to get first
 652 * @prefix:	prefix that the node name should have
 653 *
 654 * This function is like of_get_next_child(), except that it automatically
 655 * skips any nodes whose name doesn't have the given prefix.
 656 *
 657 * Return: A node pointer with refcount incremented, use
 658 * of_node_put() on it when done.
 659 */
 660struct device_node *of_get_next_child_with_prefix(const struct device_node *node,
 661						  struct device_node *prev,
 662						  const char *prefix)
 663{
 664	struct device_node *next;
 665	unsigned long flags;
 666
 667	if (!node)
 668		return NULL;
 669
 670	raw_spin_lock_irqsave(&devtree_lock, flags);
 671	next = prev ? prev->sibling : node->child;
 672	for (; next; next = next->sibling) {
 673		if (!of_node_name_prefix(next, prefix))
 674			continue;
 675		if (of_node_get(next))
 676			break;
 677	}
 678	of_node_put(prev);
 679	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 680	return next;
 681}
 682EXPORT_SYMBOL(of_get_next_child_with_prefix);
 683
 684static struct device_node *of_get_next_status_child(const struct device_node *node,
 685						    struct device_node *prev,
 686						    bool (*checker)(const struct device_node *))
 687{
 688	struct device_node *next;
 689	unsigned long flags;
 690
 691	if (!node)
 692		return NULL;
 693
 694	raw_spin_lock_irqsave(&devtree_lock, flags);
 695	next = prev ? prev->sibling : node->child;
 696	for (; next; next = next->sibling) {
 697		if (!checker(next))
 698			continue;
 699		if (of_node_get(next))
 700			break;
 701	}
 702	of_node_put(prev);
 703	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 704	return next;
 705}
 706
 707/**
 708 * of_get_next_available_child - Find the next available child node
 709 * @node:	parent node
 710 * @prev:	previous child of the parent node, or NULL to get first
 711 *
 712 * This function is like of_get_next_child(), except that it
 713 * automatically skips any disabled nodes (i.e. status = "disabled").
 714 */
 715struct device_node *of_get_next_available_child(const struct device_node *node,
 716	struct device_node *prev)
 717{
 718	return of_get_next_status_child(node, prev, __of_device_is_available);
 719}
 720EXPORT_SYMBOL(of_get_next_available_child);
 721
 722/**
 723 * of_get_next_reserved_child - Find the next reserved child node
 724 * @node:	parent node
 725 * @prev:	previous child of the parent node, or NULL to get first
 726 *
 727 * This function is like of_get_next_child(), except that it
 728 * automatically skips any disabled nodes (i.e. status = "disabled").
 729 */
 730struct device_node *of_get_next_reserved_child(const struct device_node *node,
 731						struct device_node *prev)
 732{
 733	return of_get_next_status_child(node, prev, __of_device_is_reserved);
 734}
 735EXPORT_SYMBOL(of_get_next_reserved_child);
 736
 737/**
 738 * of_get_next_cpu_node - Iterate on cpu nodes
 739 * @prev:	previous child of the /cpus node, or NULL to get first
 740 *
 741 * Unusable CPUs (those with the status property set to "fail" or "fail-...")
 742 * will be skipped.
 743 *
 744 * Return: A cpu node pointer with refcount incremented, use of_node_put()
 745 * on it when done. Returns NULL when prev is the last child. Decrements
 746 * the refcount of prev.
 747 */
 748struct device_node *of_get_next_cpu_node(struct device_node *prev)
 749{
 750	struct device_node *next = NULL;
 751	unsigned long flags;
 752	struct device_node *node;
 753
 754	if (!prev)
 755		node = of_find_node_by_path("/cpus");
 756
 757	raw_spin_lock_irqsave(&devtree_lock, flags);
 758	if (prev)
 759		next = prev->sibling;
 760	else if (node) {
 761		next = node->child;
 762		of_node_put(node);
 763	}
 764	for (; next; next = next->sibling) {
 765		if (__of_device_is_fail(next))
 766			continue;
 767		if (!(of_node_name_eq(next, "cpu") ||
 768		      __of_node_is_type(next, "cpu")))
 769			continue;
 770		if (of_node_get(next))
 771			break;
 772	}
 773	of_node_put(prev);
 774	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 775	return next;
 776}
 777EXPORT_SYMBOL(of_get_next_cpu_node);
 778
 779/**
 780 * of_get_compatible_child - Find compatible child node
 781 * @parent:	parent node
 782 * @compatible:	compatible string
 783 *
 784 * Lookup child node whose compatible property contains the given compatible
 785 * string.
 786 *
 787 * Return: a node pointer with refcount incremented, use of_node_put() on it
 788 * when done; or NULL if not found.
 789 */
 790struct device_node *of_get_compatible_child(const struct device_node *parent,
 791				const char *compatible)
 792{
 793	struct device_node *child;
 794
 795	for_each_child_of_node(parent, child) {
 796		if (of_device_is_compatible(child, compatible))
 797			break;
 798	}
 799
 800	return child;
 801}
 802EXPORT_SYMBOL(of_get_compatible_child);
 803
 804/**
 805 * of_get_child_by_name - Find the child node by name for a given parent
 806 * @node:	parent node
 807 * @name:	child name to look for.
 808 *
 809 * This function looks for child node for given matching name
 810 *
 811 * Return: A node pointer if found, with refcount incremented, use
 812 * of_node_put() on it when done.
 813 * Returns NULL if node is not found.
 814 */
 815struct device_node *of_get_child_by_name(const struct device_node *node,
 816				const char *name)
 817{
 818	struct device_node *child;
 819
 820	for_each_child_of_node(node, child)
 821		if (of_node_name_eq(child, name))
 822			break;
 823	return child;
 824}
 825EXPORT_SYMBOL(of_get_child_by_name);
 826
 827struct device_node *__of_find_node_by_path(const struct device_node *parent,
 828						const char *path)
 829{
 830	struct device_node *child;
 831	int len;
 832
 833	len = strcspn(path, "/:");
 834	if (!len)
 835		return NULL;
 836
 837	__for_each_child_of_node(parent, child) {
 838		const char *name = kbasename(child->full_name);
 839		if (strncmp(path, name, len) == 0 && (strlen(name) == len))
 840			return child;
 841	}
 842	return NULL;
 843}
 844
 845struct device_node *__of_find_node_by_full_path(struct device_node *node,
 846						const char *path)
 847{
 848	const char *separator = strchr(path, ':');
 849
 850	while (node && *path == '/') {
 851		struct device_node *tmp = node;
 852
 853		path++; /* Increment past '/' delimiter */
 854		node = __of_find_node_by_path(node, path);
 855		of_node_put(tmp);
 856		path = strchrnul(path, '/');
 857		if (separator && separator < path)
 858			break;
 859	}
 860	return node;
 861}
 862
 863/**
 864 * of_find_node_opts_by_path - Find a node matching a full OF path
 865 * @path: Either the full path to match, or if the path does not
 866 *       start with '/', the name of a property of the /aliases
 867 *       node (an alias).  In the case of an alias, the node
 868 *       matching the alias' value will be returned.
 869 * @opts: Address of a pointer into which to store the start of
 870 *       an options string appended to the end of the path with
 871 *       a ':' separator.
 872 *
 873 * Valid paths:
 874 *  * /foo/bar	Full path
 875 *  * foo	Valid alias
 876 *  * foo/bar	Valid alias + relative path
 877 *
 878 * Return: A node pointer with refcount incremented, use
 879 * of_node_put() on it when done.
 880 */
 881struct device_node *of_find_node_opts_by_path(const char *path, const char **opts)
 882{
 883	struct device_node *np = NULL;
 884	const struct property *pp;
 885	unsigned long flags;
 886	const char *separator = strchr(path, ':');
 887
 888	if (opts)
 889		*opts = separator ? separator + 1 : NULL;
 890
 891	if (strcmp(path, "/") == 0)
 892		return of_node_get(of_root);
 893
 894	/* The path could begin with an alias */
 895	if (*path != '/') {
 896		int len;
 897		const char *p = strchrnul(path, '/');
 898
 899		if (separator && separator < p)
 900			p = separator;
 901		len = p - path;
 902
 903		/* of_aliases must not be NULL */
 904		if (!of_aliases)
 905			return NULL;
 906
 907		for_each_property_of_node(of_aliases, pp) {
 908			if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
 909				np = of_find_node_by_path(pp->value);
 910				break;
 911			}
 912		}
 913		if (!np)
 914			return NULL;
 915		path = p;
 916	}
 917
 918	/* Step down the tree matching path components */
 919	raw_spin_lock_irqsave(&devtree_lock, flags);
 920	if (!np)
 921		np = of_node_get(of_root);
 922	np = __of_find_node_by_full_path(np, path);
 923	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 924	return np;
 925}
 926EXPORT_SYMBOL(of_find_node_opts_by_path);
 927
 928/**
 929 * of_find_node_by_name - Find a node by its "name" property
 930 * @from:	The node to start searching from or NULL; the node
 931 *		you pass will not be searched, only the next one
 932 *		will. Typically, you pass what the previous call
 933 *		returned. of_node_put() will be called on @from.
 934 * @name:	The name string to match against
 935 *
 936 * Return: A node pointer with refcount incremented, use
 937 * of_node_put() on it when done.
 938 */
 939struct device_node *of_find_node_by_name(struct device_node *from,
 940	const char *name)
 941{
 942	struct device_node *np;
 943	unsigned long flags;
 944
 945	raw_spin_lock_irqsave(&devtree_lock, flags);
 946	for_each_of_allnodes_from(from, np)
 947		if (of_node_name_eq(np, name) && of_node_get(np))
 948			break;
 949	of_node_put(from);
 950	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 951	return np;
 952}
 953EXPORT_SYMBOL(of_find_node_by_name);
 954
 955/**
 956 * of_find_node_by_type - Find a node by its "device_type" property
 957 * @from:	The node to start searching from, or NULL to start searching
 958 *		the entire device tree. The node you pass will not be
 959 *		searched, only the next one will; typically, you pass
 960 *		what the previous call returned. of_node_put() will be
 961 *		called on from for you.
 962 * @type:	The type string to match against
 963 *
 964 * Return: A node pointer with refcount incremented, use
 965 * of_node_put() on it when done.
 966 */
 967struct device_node *of_find_node_by_type(struct device_node *from,
 968	const char *type)
 969{
 970	struct device_node *np;
 971	unsigned long flags;
 972
 973	raw_spin_lock_irqsave(&devtree_lock, flags);
 974	for_each_of_allnodes_from(from, np)
 975		if (__of_node_is_type(np, type) && of_node_get(np))
 976			break;
 977	of_node_put(from);
 978	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 979	return np;
 980}
 981EXPORT_SYMBOL(of_find_node_by_type);
 982
 983/**
 984 * of_find_compatible_node - Find a node based on type and one of the
 985 *                                tokens in its "compatible" property
 986 * @from:	The node to start searching from or NULL, the node
 987 *		you pass will not be searched, only the next one
 988 *		will; typically, you pass what the previous call
 989 *		returned. of_node_put() will be called on it
 990 * @type:	The type string to match "device_type" or NULL to ignore
 991 * @compatible:	The string to match to one of the tokens in the device
 992 *		"compatible" list.
 993 *
 994 * Return: A node pointer with refcount incremented, use
 995 * of_node_put() on it when done.
 996 */
 997struct device_node *of_find_compatible_node(struct device_node *from,
 998	const char *type, const char *compatible)
 999{
1000	struct device_node *np;
1001	unsigned long flags;
1002
1003	raw_spin_lock_irqsave(&devtree_lock, flags);
1004	for_each_of_allnodes_from(from, np)
1005		if (__of_device_is_compatible(np, compatible, type, NULL) &&
1006		    of_node_get(np))
1007			break;
1008	of_node_put(from);
1009	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1010	return np;
1011}
1012EXPORT_SYMBOL(of_find_compatible_node);
1013
1014/**
1015 * of_find_node_with_property - Find a node which has a property with
1016 *                              the given name.
1017 * @from:	The node to start searching from or NULL, the node
1018 *		you pass will not be searched, only the next one
1019 *		will; typically, you pass what the previous call
1020 *		returned. of_node_put() will be called on it
1021 * @prop_name:	The name of the property to look for.
1022 *
1023 * Return: A node pointer with refcount incremented, use
1024 * of_node_put() on it when done.
1025 */
1026struct device_node *of_find_node_with_property(struct device_node *from,
1027	const char *prop_name)
1028{
1029	struct device_node *np;
1030	const struct property *pp;
1031	unsigned long flags;
1032
1033	raw_spin_lock_irqsave(&devtree_lock, flags);
1034	for_each_of_allnodes_from(from, np) {
1035		for (pp = np->properties; pp; pp = pp->next) {
1036			if (of_prop_cmp(pp->name, prop_name) == 0) {
1037				of_node_get(np);
1038				goto out;
1039			}
1040		}
1041	}
1042out:
1043	of_node_put(from);
1044	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1045	return np;
1046}
1047EXPORT_SYMBOL(of_find_node_with_property);
1048
1049static
1050const struct of_device_id *__of_match_node(const struct of_device_id *matches,
1051					   const struct device_node *node)
1052{
1053	const struct of_device_id *best_match = NULL;
1054	int score, best_score = 0;
1055
1056	if (!matches)
1057		return NULL;
1058
1059	for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
1060		score = __of_device_is_compatible(node, matches->compatible,
1061						  matches->type, matches->name);
1062		if (score > best_score) {
1063			best_match = matches;
1064			best_score = score;
1065		}
1066	}
1067
1068	return best_match;
1069}
1070
1071/**
1072 * of_match_node - Tell if a device_node has a matching of_match structure
1073 * @matches:	array of of device match structures to search in
1074 * @node:	the of device structure to match against
1075 *
1076 * Low level utility function used by device matching.
1077 */
1078const struct of_device_id *of_match_node(const struct of_device_id *matches,
1079					 const struct device_node *node)
1080{
1081	const struct of_device_id *match;
1082	unsigned long flags;
1083
1084	raw_spin_lock_irqsave(&devtree_lock, flags);
1085	match = __of_match_node(matches, node);
1086	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1087	return match;
1088}
1089EXPORT_SYMBOL(of_match_node);
1090
1091/**
1092 * of_find_matching_node_and_match - Find a node based on an of_device_id
1093 *				     match table.
1094 * @from:	The node to start searching from or NULL, the node
1095 *		you pass will not be searched, only the next one
1096 *		will; typically, you pass what the previous call
1097 *		returned. of_node_put() will be called on it
1098 * @matches:	array of of device match structures to search in
1099 * @match:	Updated to point at the matches entry which matched
1100 *
1101 * Return: A node pointer with refcount incremented, use
1102 * of_node_put() on it when done.
1103 */
1104struct device_node *of_find_matching_node_and_match(struct device_node *from,
1105					const struct of_device_id *matches,
1106					const struct of_device_id **match)
1107{
1108	struct device_node *np;
1109	const struct of_device_id *m;
1110	unsigned long flags;
1111
1112	if (match)
1113		*match = NULL;
1114
1115	raw_spin_lock_irqsave(&devtree_lock, flags);
1116	for_each_of_allnodes_from(from, np) {
1117		m = __of_match_node(matches, np);
1118		if (m && of_node_get(np)) {
1119			if (match)
1120				*match = m;
1121			break;
1122		}
1123	}
1124	of_node_put(from);
1125	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1126	return np;
1127}
1128EXPORT_SYMBOL(of_find_matching_node_and_match);
1129
1130/**
1131 * of_alias_from_compatible - Lookup appropriate alias for a device node
1132 *			      depending on compatible
1133 * @node:	pointer to a device tree node
1134 * @alias:	Pointer to buffer that alias value will be copied into
1135 * @len:	Length of alias value
1136 *
1137 * Based on the value of the compatible property, this routine will attempt
1138 * to choose an appropriate alias value for a particular device tree node.
1139 * It does this by stripping the manufacturer prefix (as delimited by a ',')
1140 * from the first entry in the compatible list property.
1141 *
1142 * Note: The matching on just the "product" side of the compatible is a relic
1143 * from I2C and SPI. Please do not add any new user.
1144 *
1145 * Return: This routine returns 0 on success, <0 on failure.
1146 */
1147int of_alias_from_compatible(const struct device_node *node, char *alias, int len)
1148{
1149	const char *compatible, *p;
1150	int cplen;
1151
1152	compatible = of_get_property(node, "compatible", &cplen);
1153	if (!compatible || strlen(compatible) > cplen)
1154		return -ENODEV;
1155	p = strchr(compatible, ',');
1156	strscpy(alias, p ? p + 1 : compatible, len);
1157	return 0;
1158}
1159EXPORT_SYMBOL_GPL(of_alias_from_compatible);
1160
1161/**
1162 * of_find_node_by_phandle - Find a node given a phandle
1163 * @handle:	phandle of the node to find
1164 *
1165 * Return: A node pointer with refcount incremented, use
1166 * of_node_put() on it when done.
1167 */
1168struct device_node *of_find_node_by_phandle(phandle handle)
1169{
1170	struct device_node *np = NULL;
1171	unsigned long flags;
1172	u32 handle_hash;
1173
1174	if (!handle)
1175		return NULL;
1176
1177	handle_hash = of_phandle_cache_hash(handle);
1178
1179	raw_spin_lock_irqsave(&devtree_lock, flags);
1180
1181	if (phandle_cache[handle_hash] &&
1182	    handle == phandle_cache[handle_hash]->phandle)
1183		np = phandle_cache[handle_hash];
1184
1185	if (!np) {
1186		for_each_of_allnodes(np)
1187			if (np->phandle == handle &&
1188			    !of_node_check_flag(np, OF_DETACHED)) {
1189				phandle_cache[handle_hash] = np;
1190				break;
1191			}
1192	}
1193
1194	of_node_get(np);
1195	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1196	return np;
1197}
1198EXPORT_SYMBOL(of_find_node_by_phandle);
1199
1200void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
1201{
1202	int i;
1203	printk("%s %pOF", msg, args->np);
1204	for (i = 0; i < args->args_count; i++) {
1205		const char delim = i ? ',' : ':';
1206
1207		pr_cont("%c%08x", delim, args->args[i]);
1208	}
1209	pr_cont("\n");
1210}
1211
1212int of_phandle_iterator_init(struct of_phandle_iterator *it,
1213		const struct device_node *np,
1214		const char *list_name,
1215		const char *cells_name,
1216		int cell_count)
1217{
1218	const __be32 *list;
1219	int size;
1220
1221	memset(it, 0, sizeof(*it));
1222
1223	/*
1224	 * one of cell_count or cells_name must be provided to determine the
1225	 * argument length.
1226	 */
1227	if (cell_count < 0 && !cells_name)
1228		return -EINVAL;
1229
1230	list = of_get_property(np, list_name, &size);
1231	if (!list)
1232		return -ENOENT;
1233
1234	it->cells_name = cells_name;
1235	it->cell_count = cell_count;
1236	it->parent = np;
1237	it->list_end = list + size / sizeof(*list);
1238	it->phandle_end = list;
1239	it->cur = list;
1240
1241	return 0;
1242}
1243EXPORT_SYMBOL_GPL(of_phandle_iterator_init);
1244
1245int of_phandle_iterator_next(struct of_phandle_iterator *it)
1246{
1247	uint32_t count = 0;
1248
1249	if (it->node) {
1250		of_node_put(it->node);
1251		it->node = NULL;
1252	}
1253
1254	if (!it->cur || it->phandle_end >= it->list_end)
1255		return -ENOENT;
1256
1257	it->cur = it->phandle_end;
1258
1259	/* If phandle is 0, then it is an empty entry with no arguments. */
1260	it->phandle = be32_to_cpup(it->cur++);
1261
1262	if (it->phandle) {
1263
1264		/*
1265		 * Find the provider node and parse the #*-cells property to
1266		 * determine the argument length.
1267		 */
1268		it->node = of_find_node_by_phandle(it->phandle);
1269
1270		if (it->cells_name) {
1271			if (!it->node) {
1272				pr_err("%pOF: could not find phandle %d\n",
1273				       it->parent, it->phandle);
1274				goto err;
1275			}
1276
1277			if (of_property_read_u32(it->node, it->cells_name,
1278						 &count)) {
1279				/*
1280				 * If both cell_count and cells_name is given,
1281				 * fall back to cell_count in absence
1282				 * of the cells_name property
1283				 */
1284				if (it->cell_count >= 0) {
1285					count = it->cell_count;
1286				} else {
1287					pr_err("%pOF: could not get %s for %pOF\n",
1288					       it->parent,
1289					       it->cells_name,
1290					       it->node);
1291					goto err;
1292				}
1293			}
1294		} else {
1295			count = it->cell_count;
1296		}
1297
1298		/*
1299		 * Make sure that the arguments actually fit in the remaining
1300		 * property data length
1301		 */
1302		if (it->cur + count > it->list_end) {
1303			if (it->cells_name)
1304				pr_err("%pOF: %s = %d found %td\n",
1305					it->parent, it->cells_name,
1306					count, it->list_end - it->cur);
1307			else
1308				pr_err("%pOF: phandle %s needs %d, found %td\n",
1309					it->parent, of_node_full_name(it->node),
1310					count, it->list_end - it->cur);
1311			goto err;
1312		}
1313	}
1314
1315	it->phandle_end = it->cur + count;
1316	it->cur_count = count;
1317
1318	return 0;
1319
1320err:
1321	if (it->node) {
1322		of_node_put(it->node);
1323		it->node = NULL;
1324	}
1325
1326	return -EINVAL;
1327}
1328EXPORT_SYMBOL_GPL(of_phandle_iterator_next);
1329
1330int of_phandle_iterator_args(struct of_phandle_iterator *it,
1331			     uint32_t *args,
1332			     int size)
1333{
1334	int i, count;
1335
1336	count = it->cur_count;
1337
1338	if (WARN_ON(size < count))
1339		count = size;
1340
1341	for (i = 0; i < count; i++)
1342		args[i] = be32_to_cpup(it->cur++);
1343
1344	return count;
1345}
1346
1347int __of_parse_phandle_with_args(const struct device_node *np,
1348				 const char *list_name,
1349				 const char *cells_name,
1350				 int cell_count, int index,
1351				 struct of_phandle_args *out_args)
1352{
1353	struct of_phandle_iterator it;
1354	int rc, cur_index = 0;
1355
1356	if (index < 0)
1357		return -EINVAL;
1358
1359	/* Loop over the phandles until all the requested entry is found */
1360	of_for_each_phandle(&it, rc, np, list_name, cells_name, cell_count) {
1361		/*
1362		 * All of the error cases bail out of the loop, so at
1363		 * this point, the parsing is successful. If the requested
1364		 * index matches, then fill the out_args structure and return,
1365		 * or return -ENOENT for an empty entry.
1366		 */
1367		rc = -ENOENT;
1368		if (cur_index == index) {
1369			if (!it.phandle)
1370				goto err;
1371
1372			if (out_args) {
1373				int c;
1374
1375				c = of_phandle_iterator_args(&it,
1376							     out_args->args,
1377							     MAX_PHANDLE_ARGS);
1378				out_args->np = it.node;
1379				out_args->args_count = c;
1380			} else {
1381				of_node_put(it.node);
1382			}
1383
1384			/* Found it! return success */
1385			return 0;
1386		}
1387
1388		cur_index++;
1389	}
1390
1391	/*
1392	 * Unlock node before returning result; will be one of:
1393	 * -ENOENT : index is for empty phandle
1394	 * -EINVAL : parsing error on data
1395	 */
1396
1397 err:
1398	of_node_put(it.node);
1399	return rc;
1400}
1401EXPORT_SYMBOL(__of_parse_phandle_with_args);
1402
1403/**
1404 * of_parse_phandle_with_args_map() - Find a node pointed by phandle in a list and remap it
1405 * @np:		pointer to a device tree node containing a list
1406 * @list_name:	property name that contains a list
1407 * @stem_name:	stem of property names that specify phandles' arguments count
1408 * @index:	index of a phandle to parse out
1409 * @out_args:	optional pointer to output arguments structure (will be filled)
1410 *
1411 * This function is useful to parse lists of phandles and their arguments.
1412 * Returns 0 on success and fills out_args, on error returns appropriate errno
1413 * value. The difference between this function and of_parse_phandle_with_args()
1414 * is that this API remaps a phandle if the node the phandle points to has
1415 * a <@stem_name>-map property.
1416 *
1417 * Caller is responsible to call of_node_put() on the returned out_args->np
1418 * pointer.
1419 *
1420 * Example::
1421 *
1422 *  phandle1: node1 {
1423 *  	#list-cells = <2>;
1424 *  };
1425 *
1426 *  phandle2: node2 {
1427 *  	#list-cells = <1>;
1428 *  };
1429 *
1430 *  phandle3: node3 {
1431 *  	#list-cells = <1>;
1432 *  	list-map = <0 &phandle2 3>,
1433 *  		   <1 &phandle2 2>,
1434 *  		   <2 &phandle1 5 1>;
1435 *  	list-map-mask = <0x3>;
1436 *  };
1437 *
1438 *  node4 {
1439 *  	list = <&phandle1 1 2 &phandle3 0>;
1440 *  };
1441 *
1442 * To get a device_node of the ``node2`` node you may call this:
1443 * of_parse_phandle_with_args(node4, "list", "list", 1, &args);
1444 */
1445int of_parse_phandle_with_args_map(const struct device_node *np,
1446				   const char *list_name,
1447				   const char *stem_name,
1448				   int index, struct of_phandle_args *out_args)
1449{
1450	char *cells_name __free(kfree) = kasprintf(GFP_KERNEL, "#%s-cells", stem_name);
1451	char *map_name __free(kfree) = kasprintf(GFP_KERNEL, "%s-map", stem_name);
1452	char *mask_name __free(kfree) = kasprintf(GFP_KERNEL, "%s-map-mask", stem_name);
1453	char *pass_name __free(kfree) = kasprintf(GFP_KERNEL, "%s-map-pass-thru", stem_name);
1454	struct device_node *cur, *new = NULL;
1455	const __be32 *map, *mask, *pass;
1456	static const __be32 dummy_mask[] = { [0 ... MAX_PHANDLE_ARGS] = cpu_to_be32(~0) };
1457	static const __be32 dummy_pass[] = { [0 ... MAX_PHANDLE_ARGS] = cpu_to_be32(0) };
1458	__be32 initial_match_array[MAX_PHANDLE_ARGS];
1459	const __be32 *match_array = initial_match_array;
1460	int i, ret, map_len, match;
1461	u32 list_size, new_size;
1462
1463	if (index < 0)
1464		return -EINVAL;
1465
1466	if (!cells_name || !map_name || !mask_name || !pass_name)
 
1467		return -ENOMEM;
1468
 
 
 
 
 
 
 
 
 
 
 
 
 
1469	ret = __of_parse_phandle_with_args(np, list_name, cells_name, -1, index,
1470					   out_args);
1471	if (ret)
1472		return ret;
1473
1474	/* Get the #<list>-cells property */
1475	cur = out_args->np;
1476	ret = of_property_read_u32(cur, cells_name, &list_size);
1477	if (ret < 0)
1478		goto put;
1479
1480	/* Precalculate the match array - this simplifies match loop */
1481	for (i = 0; i < list_size; i++)
1482		initial_match_array[i] = cpu_to_be32(out_args->args[i]);
1483
1484	ret = -EINVAL;
1485	while (cur) {
1486		/* Get the <list>-map property */
1487		map = of_get_property(cur, map_name, &map_len);
1488		if (!map) {
1489			return 0;
 
1490		}
1491		map_len /= sizeof(u32);
1492
1493		/* Get the <list>-map-mask property (optional) */
1494		mask = of_get_property(cur, mask_name, NULL);
1495		if (!mask)
1496			mask = dummy_mask;
1497		/* Iterate through <list>-map property */
1498		match = 0;
1499		while (map_len > (list_size + 1) && !match) {
1500			/* Compare specifiers */
1501			match = 1;
1502			for (i = 0; i < list_size; i++, map_len--)
1503				match &= !((match_array[i] ^ *map++) & mask[i]);
1504
1505			of_node_put(new);
1506			new = of_find_node_by_phandle(be32_to_cpup(map));
1507			map++;
1508			map_len--;
1509
1510			/* Check if not found */
1511			if (!new) {
1512				ret = -EINVAL;
1513				goto put;
1514			}
1515
1516			if (!of_device_is_available(new))
1517				match = 0;
1518
1519			ret = of_property_read_u32(new, cells_name, &new_size);
1520			if (ret)
1521				goto put;
1522
1523			/* Check for malformed properties */
1524			if (WARN_ON(new_size > MAX_PHANDLE_ARGS) ||
1525			    map_len < new_size) {
1526				ret = -EINVAL;
1527				goto put;
1528			}
1529
1530			/* Move forward by new node's #<list>-cells amount */
1531			map += new_size;
1532			map_len -= new_size;
1533		}
1534		if (!match) {
1535			ret = -ENOENT;
1536			goto put;
1537		}
1538
1539		/* Get the <list>-map-pass-thru property (optional) */
1540		pass = of_get_property(cur, pass_name, NULL);
1541		if (!pass)
1542			pass = dummy_pass;
1543
1544		/*
1545		 * Successfully parsed a <list>-map translation; copy new
1546		 * specifier into the out_args structure, keeping the
1547		 * bits specified in <list>-map-pass-thru.
1548		 */
 
1549		for (i = 0; i < new_size; i++) {
1550			__be32 val = *(map - new_size + i);
1551
1552			if (i < list_size) {
1553				val &= ~pass[i];
1554				val |= cpu_to_be32(out_args->args[i]) & pass[i];
1555			}
1556
1557			initial_match_array[i] = val;
1558			out_args->args[i] = be32_to_cpu(val);
1559		}
1560		out_args->args_count = list_size = new_size;
1561		/* Iterate again with new provider */
1562		out_args->np = new;
1563		of_node_put(cur);
1564		cur = new;
1565		new = NULL;
1566	}
1567put:
1568	of_node_put(cur);
1569	of_node_put(new);
 
 
 
 
 
 
1570	return ret;
1571}
1572EXPORT_SYMBOL(of_parse_phandle_with_args_map);
1573
1574/**
1575 * of_count_phandle_with_args() - Find the number of phandles references in a property
1576 * @np:		pointer to a device tree node containing a list
1577 * @list_name:	property name that contains a list
1578 * @cells_name:	property name that specifies phandles' arguments count
1579 *
1580 * Return: The number of phandle + argument tuples within a property. It
1581 * is a typical pattern to encode a list of phandle and variable
1582 * arguments into a single property. The number of arguments is encoded
1583 * by a property in the phandle-target node. For example, a gpios
1584 * property would contain a list of GPIO specifies consisting of a
1585 * phandle and 1 or more arguments. The number of arguments are
1586 * determined by the #gpio-cells property in the node pointed to by the
1587 * phandle.
1588 */
1589int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1590				const char *cells_name)
1591{
1592	struct of_phandle_iterator it;
1593	int rc, cur_index = 0;
1594
1595	/*
1596	 * If cells_name is NULL we assume a cell count of 0. This makes
1597	 * counting the phandles trivial as each 32bit word in the list is a
1598	 * phandle and no arguments are to consider. So we don't iterate through
1599	 * the list but just use the length to determine the phandle count.
1600	 */
1601	if (!cells_name) {
1602		const __be32 *list;
1603		int size;
1604
1605		list = of_get_property(np, list_name, &size);
1606		if (!list)
1607			return -ENOENT;
1608
1609		return size / sizeof(*list);
1610	}
1611
1612	rc = of_phandle_iterator_init(&it, np, list_name, cells_name, -1);
1613	if (rc)
1614		return rc;
1615
1616	while ((rc = of_phandle_iterator_next(&it)) == 0)
1617		cur_index += 1;
1618
1619	if (rc != -ENOENT)
1620		return rc;
1621
1622	return cur_index;
1623}
1624EXPORT_SYMBOL(of_count_phandle_with_args);
1625
1626static struct property *__of_remove_property_from_list(struct property **list, struct property *prop)
1627{
1628	struct property **next;
1629
1630	for (next = list; *next; next = &(*next)->next) {
1631		if (*next == prop) {
1632			*next = prop->next;
1633			prop->next = NULL;
1634			return prop;
1635		}
1636	}
1637	return NULL;
1638}
1639
1640/**
1641 * __of_add_property - Add a property to a node without lock operations
1642 * @np:		Caller's Device Node
1643 * @prop:	Property to add
1644 */
1645int __of_add_property(struct device_node *np, struct property *prop)
1646{
1647	int rc = 0;
1648	unsigned long flags;
1649	struct property **next;
1650
1651	raw_spin_lock_irqsave(&devtree_lock, flags);
1652
1653	__of_remove_property_from_list(&np->deadprops, prop);
1654
1655	prop->next = NULL;
1656	next = &np->properties;
1657	while (*next) {
1658		if (strcmp(prop->name, (*next)->name) == 0) {
1659			/* duplicate ! don't insert it */
1660			rc = -EEXIST;
1661			goto out_unlock;
1662		}
1663		next = &(*next)->next;
1664	}
1665	*next = prop;
1666
1667out_unlock:
1668	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1669	if (rc)
1670		return rc;
1671
1672	__of_add_property_sysfs(np, prop);
1673	return 0;
1674}
1675
1676/**
1677 * of_add_property - Add a property to a node
1678 * @np:		Caller's Device Node
1679 * @prop:	Property to add
1680 */
1681int of_add_property(struct device_node *np, struct property *prop)
1682{
1683	int rc;
1684
1685	mutex_lock(&of_mutex);
1686	rc = __of_add_property(np, prop);
1687	mutex_unlock(&of_mutex);
1688
1689	if (!rc)
1690		of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
1691
1692	return rc;
1693}
1694EXPORT_SYMBOL_GPL(of_add_property);
1695
1696int __of_remove_property(struct device_node *np, struct property *prop)
1697{
1698	unsigned long flags;
1699	int rc = -ENODEV;
1700
1701	raw_spin_lock_irqsave(&devtree_lock, flags);
1702
1703	if (__of_remove_property_from_list(&np->properties, prop)) {
1704		/* Found the property, add it to deadprops list */
1705		prop->next = np->deadprops;
1706		np->deadprops = prop;
1707		rc = 0;
1708	}
1709
1710	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1711	if (rc)
1712		return rc;
1713
1714	__of_remove_property_sysfs(np, prop);
1715	return 0;
1716}
1717
1718/**
1719 * of_remove_property - Remove a property from a node.
1720 * @np:		Caller's Device Node
1721 * @prop:	Property to remove
1722 *
1723 * Note that we don't actually remove it, since we have given out
1724 * who-knows-how-many pointers to the data using get-property.
1725 * Instead we just move the property to the "dead properties"
1726 * list, so it won't be found any more.
1727 */
1728int of_remove_property(struct device_node *np, struct property *prop)
1729{
1730	int rc;
1731
1732	if (!prop)
1733		return -ENODEV;
1734
1735	mutex_lock(&of_mutex);
1736	rc = __of_remove_property(np, prop);
1737	mutex_unlock(&of_mutex);
1738
1739	if (!rc)
1740		of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
1741
1742	return rc;
1743}
1744EXPORT_SYMBOL_GPL(of_remove_property);
1745
1746int __of_update_property(struct device_node *np, struct property *newprop,
1747		struct property **oldpropp)
1748{
1749	struct property **next, *oldprop;
1750	unsigned long flags;
1751
1752	raw_spin_lock_irqsave(&devtree_lock, flags);
1753
1754	__of_remove_property_from_list(&np->deadprops, newprop);
1755
1756	for (next = &np->properties; *next; next = &(*next)->next) {
1757		if (of_prop_cmp((*next)->name, newprop->name) == 0)
1758			break;
1759	}
1760	*oldpropp = oldprop = *next;
1761
1762	if (oldprop) {
1763		/* replace the node */
1764		newprop->next = oldprop->next;
1765		*next = newprop;
1766		oldprop->next = np->deadprops;
1767		np->deadprops = oldprop;
1768	} else {
1769		/* new node */
1770		newprop->next = NULL;
1771		*next = newprop;
1772	}
1773
1774	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1775
1776	__of_update_property_sysfs(np, newprop, oldprop);
1777
1778	return 0;
1779}
1780
1781/*
1782 * of_update_property - Update a property in a node, if the property does
1783 * not exist, add it.
1784 *
1785 * Note that we don't actually remove it, since we have given out
1786 * who-knows-how-many pointers to the data using get-property.
1787 * Instead we just move the property to the "dead properties" list,
1788 * and add the new property to the property list
1789 */
1790int of_update_property(struct device_node *np, struct property *newprop)
1791{
1792	struct property *oldprop;
1793	int rc;
1794
1795	if (!newprop->name)
1796		return -EINVAL;
1797
1798	mutex_lock(&of_mutex);
1799	rc = __of_update_property(np, newprop, &oldprop);
1800	mutex_unlock(&of_mutex);
1801
1802	if (!rc)
1803		of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
1804
1805	return rc;
1806}
1807
1808static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1809			 int id, const char *stem, int stem_len)
1810{
1811	ap->np = np;
1812	ap->id = id;
1813	strscpy(ap->stem, stem, stem_len + 1);
1814	list_add_tail(&ap->link, &aliases_lookup);
1815	pr_debug("adding DT alias:%s: stem=%s id=%i node=%pOF\n",
1816		 ap->alias, ap->stem, ap->id, np);
1817}
1818
1819/**
1820 * of_alias_scan - Scan all properties of the 'aliases' node
1821 * @dt_alloc:	An allocator that provides a virtual address to memory
1822 *		for storing the resulting tree
1823 *
1824 * The function scans all the properties of the 'aliases' node and populates
1825 * the global lookup table with the properties.  It returns the
1826 * number of alias properties found, or an error code in case of failure.
1827 */
1828void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1829{
1830	const struct property *pp;
1831
1832	of_aliases = of_find_node_by_path("/aliases");
1833	of_chosen = of_find_node_by_path("/chosen");
1834	if (of_chosen == NULL)
1835		of_chosen = of_find_node_by_path("/chosen@0");
1836
1837	if (of_chosen) {
1838		/* linux,stdout-path and /aliases/stdout are for legacy compatibility */
1839		const char *name = NULL;
1840
1841		if (of_property_read_string(of_chosen, "stdout-path", &name))
1842			of_property_read_string(of_chosen, "linux,stdout-path",
1843						&name);
1844		if (IS_ENABLED(CONFIG_PPC) && !name)
1845			of_property_read_string(of_aliases, "stdout", &name);
1846		if (name)
1847			of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
1848		if (of_stdout)
1849			of_stdout->fwnode.flags |= FWNODE_FLAG_BEST_EFFORT;
1850	}
1851
1852	if (!of_aliases)
1853		return;
1854
1855	for_each_property_of_node(of_aliases, pp) {
1856		const char *start = pp->name;
1857		const char *end = start + strlen(start);
1858		struct device_node *np;
1859		struct alias_prop *ap;
1860		int id, len;
1861
1862		/* Skip those we do not want to proceed */
1863		if (!strcmp(pp->name, "name") ||
1864		    !strcmp(pp->name, "phandle") ||
1865		    !strcmp(pp->name, "linux,phandle"))
1866			continue;
1867
1868		np = of_find_node_by_path(pp->value);
1869		if (!np)
1870			continue;
1871
1872		/* walk the alias backwards to extract the id and work out
1873		 * the 'stem' string */
1874		while (isdigit(*(end-1)) && end > start)
1875			end--;
1876		len = end - start;
1877
1878		if (kstrtoint(end, 10, &id) < 0)
1879			continue;
1880
1881		/* Allocate an alias_prop with enough space for the stem */
1882		ap = dt_alloc(sizeof(*ap) + len + 1, __alignof__(*ap));
1883		if (!ap)
1884			continue;
1885		memset(ap, 0, sizeof(*ap) + len + 1);
1886		ap->alias = start;
1887		of_alias_add(ap, np, id, start, len);
1888	}
1889}
1890
1891/**
1892 * of_alias_get_id - Get alias id for the given device_node
1893 * @np:		Pointer to the given device_node
1894 * @stem:	Alias stem of the given device_node
1895 *
1896 * The function travels the lookup table to get the alias id for the given
1897 * device_node and alias stem.
1898 *
1899 * Return: The alias id if found.
1900 */
1901int of_alias_get_id(const struct device_node *np, const char *stem)
1902{
1903	struct alias_prop *app;
1904	int id = -ENODEV;
1905
1906	mutex_lock(&of_mutex);
1907	list_for_each_entry(app, &aliases_lookup, link) {
1908		if (strcmp(app->stem, stem) != 0)
1909			continue;
1910
1911		if (np == app->np) {
1912			id = app->id;
1913			break;
1914		}
1915	}
1916	mutex_unlock(&of_mutex);
1917
1918	return id;
1919}
1920EXPORT_SYMBOL_GPL(of_alias_get_id);
1921
1922/**
1923 * of_alias_get_highest_id - Get highest alias id for the given stem
1924 * @stem:	Alias stem to be examined
1925 *
1926 * The function travels the lookup table to get the highest alias id for the
1927 * given alias stem.  It returns the alias id if found.
1928 */
1929int of_alias_get_highest_id(const char *stem)
1930{
1931	struct alias_prop *app;
1932	int id = -ENODEV;
1933
1934	mutex_lock(&of_mutex);
1935	list_for_each_entry(app, &aliases_lookup, link) {
1936		if (strcmp(app->stem, stem) != 0)
1937			continue;
1938
1939		if (app->id > id)
1940			id = app->id;
1941	}
1942	mutex_unlock(&of_mutex);
1943
1944	return id;
1945}
1946EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
1947
1948/**
1949 * of_console_check() - Test and setup console for DT setup
1950 * @dn: Pointer to device node
1951 * @name: Name to use for preferred console without index. ex. "ttyS"
1952 * @index: Index to use for preferred console.
1953 *
1954 * Check if the given device node matches the stdout-path property in the
1955 * /chosen node. If it does then register it as the preferred console.
1956 *
1957 * Return: TRUE if console successfully setup. Otherwise return FALSE.
1958 */
1959bool of_console_check(const struct device_node *dn, char *name, int index)
1960{
1961	if (!dn || dn != of_stdout || console_set_on_cmdline)
1962		return false;
1963
1964	/*
1965	 * XXX: cast `options' to char pointer to suppress complication
1966	 * warnings: printk, UART and console drivers expect char pointer.
1967	 */
1968	return !add_preferred_console(name, index, (char *)of_stdout_options);
1969}
1970EXPORT_SYMBOL_GPL(of_console_check);
1971
1972/**
1973 * of_find_next_cache_node - Find a node's subsidiary cache
1974 * @np:	node of type "cpu" or "cache"
1975 *
1976 * Return: A node pointer with refcount incremented, use
1977 * of_node_put() on it when done.  Caller should hold a reference
1978 * to np.
1979 */
1980struct device_node *of_find_next_cache_node(const struct device_node *np)
1981{
1982	struct device_node *child, *cache_node;
1983
1984	cache_node = of_parse_phandle(np, "l2-cache", 0);
1985	if (!cache_node)
1986		cache_node = of_parse_phandle(np, "next-level-cache", 0);
1987
1988	if (cache_node)
1989		return cache_node;
1990
1991	/* OF on pmac has nodes instead of properties named "l2-cache"
1992	 * beneath CPU nodes.
1993	 */
1994	if (IS_ENABLED(CONFIG_PPC_PMAC) && of_node_is_type(np, "cpu"))
1995		for_each_child_of_node(np, child)
1996			if (of_node_is_type(child, "cache"))
1997				return child;
1998
1999	return NULL;
2000}
2001
2002/**
2003 * of_find_last_cache_level - Find the level at which the last cache is
2004 * 		present for the given logical cpu
2005 *
2006 * @cpu: cpu number(logical index) for which the last cache level is needed
2007 *
2008 * Return: The level at which the last cache is present. It is exactly
2009 * same as  the total number of cache levels for the given logical cpu.
2010 */
2011int of_find_last_cache_level(unsigned int cpu)
2012{
2013	u32 cache_level = 0;
2014	struct device_node *prev = NULL, *np = of_cpu_device_node_get(cpu);
2015
2016	while (np) {
2017		of_node_put(prev);
2018		prev = np;
2019		np = of_find_next_cache_node(np);
2020	}
2021
2022	of_property_read_u32(prev, "cache-level", &cache_level);
2023	of_node_put(prev);
2024
2025	return cache_level;
2026}
2027
2028/**
2029 * of_map_id - Translate an ID through a downstream mapping.
2030 * @np: root complex device node.
2031 * @id: device ID to map.
2032 * @map_name: property name of the map to use.
2033 * @map_mask_name: optional property name of the mask to use.
2034 * @target: optional pointer to a target device node.
2035 * @id_out: optional pointer to receive the translated ID.
2036 *
2037 * Given a device ID, look up the appropriate implementation-defined
2038 * platform ID and/or the target device which receives transactions on that
2039 * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
2040 * @id_out may be NULL if only the other is required. If @target points to
2041 * a non-NULL device node pointer, only entries targeting that node will be
2042 * matched; if it points to a NULL value, it will receive the device node of
2043 * the first matching target phandle, with a reference held.
2044 *
2045 * Return: 0 on success or a standard error code on failure.
2046 */
2047int of_map_id(const struct device_node *np, u32 id,
2048	       const char *map_name, const char *map_mask_name,
2049	       struct device_node **target, u32 *id_out)
2050{
2051	u32 map_mask, masked_id;
2052	int map_len;
2053	const __be32 *map = NULL;
2054
2055	if (!np || !map_name || (!target && !id_out))
2056		return -EINVAL;
2057
2058	map = of_get_property(np, map_name, &map_len);
2059	if (!map) {
2060		if (target)
2061			return -ENODEV;
2062		/* Otherwise, no map implies no translation */
2063		*id_out = id;
2064		return 0;
2065	}
2066
2067	if (!map_len || map_len % (4 * sizeof(*map))) {
2068		pr_err("%pOF: Error: Bad %s length: %d\n", np,
2069			map_name, map_len);
2070		return -EINVAL;
2071	}
2072
2073	/* The default is to select all bits. */
2074	map_mask = 0xffffffff;
2075
2076	/*
2077	 * Can be overridden by "{iommu,msi}-map-mask" property.
2078	 * If of_property_read_u32() fails, the default is used.
2079	 */
2080	if (map_mask_name)
2081		of_property_read_u32(np, map_mask_name, &map_mask);
2082
2083	masked_id = map_mask & id;
2084	for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
2085		struct device_node *phandle_node;
2086		u32 id_base = be32_to_cpup(map + 0);
2087		u32 phandle = be32_to_cpup(map + 1);
2088		u32 out_base = be32_to_cpup(map + 2);
2089		u32 id_len = be32_to_cpup(map + 3);
2090
2091		if (id_base & ~map_mask) {
2092			pr_err("%pOF: Invalid %s translation - %s-mask (0x%x) ignores id-base (0x%x)\n",
2093				np, map_name, map_name,
2094				map_mask, id_base);
2095			return -EFAULT;
2096		}
2097
2098		if (masked_id < id_base || masked_id >= id_base + id_len)
2099			continue;
2100
2101		phandle_node = of_find_node_by_phandle(phandle);
2102		if (!phandle_node)
2103			return -ENODEV;
2104
2105		if (target) {
2106			if (*target)
2107				of_node_put(phandle_node);
2108			else
2109				*target = phandle_node;
2110
2111			if (*target != phandle_node)
2112				continue;
2113		}
2114
2115		if (id_out)
2116			*id_out = masked_id - id_base + out_base;
2117
2118		pr_debug("%pOF: %s, using mask %08x, id-base: %08x, out-base: %08x, length: %08x, id: %08x -> %08x\n",
2119			np, map_name, map_mask, id_base, out_base,
2120			id_len, id, masked_id - id_base + out_base);
2121		return 0;
2122	}
2123
2124	pr_info("%pOF: no %s translation for id 0x%x on %pOF\n", np, map_name,
2125		id, target && *target ? *target : NULL);
2126
2127	/* Bypasses translation */
2128	if (id_out)
2129		*id_out = id;
2130	return 0;
2131}
2132EXPORT_SYMBOL_GPL(of_map_id);