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v6.13.7
   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);
v4.10.11
 
   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
  21#define pr_fmt(fmt)	"OF: " fmt
  22
 
  23#include <linux/console.h>
  24#include <linux/ctype.h>
  25#include <linux/cpu.h>
  26#include <linux/module.h>
  27#include <linux/of.h>
 
  28#include <linux/of_graph.h>
  29#include <linux/spinlock.h>
  30#include <linux/slab.h>
  31#include <linux/string.h>
  32#include <linux/proc_fs.h>
  33
  34#include "of_private.h"
  35
  36LIST_HEAD(aliases_lookup);
  37
  38struct device_node *of_root;
  39EXPORT_SYMBOL(of_root);
  40struct device_node *of_chosen;
 
  41struct device_node *of_aliases;
  42struct device_node *of_stdout;
  43static const char *of_stdout_options;
  44
  45struct kset *of_kset;
  46
  47/*
  48 * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
  49 * This mutex must be held whenever modifications are being made to the
  50 * device tree. The of_{attach,detach}_node() and
  51 * of_{add,remove,update}_property() helpers make sure this happens.
  52 */
  53DEFINE_MUTEX(of_mutex);
  54
  55/* use when traversing tree through the child, sibling,
  56 * or parent members of struct device_node.
  57 */
  58DEFINE_RAW_SPINLOCK(devtree_lock);
  59
  60int of_n_addr_cells(struct device_node *np)
  61{
  62	const __be32 *ip;
 
 
 
 
 
 
 
  63
  64	do {
  65		if (np->parent)
  66			np = np->parent;
  67		ip = of_get_property(np, "#address-cells", NULL);
  68		if (ip)
  69			return be32_to_cpup(ip);
  70	} while (np->parent);
  71	/* No #address-cells property for the root node */
  72	return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
  73}
  74EXPORT_SYMBOL(of_n_addr_cells);
  75
  76int of_n_size_cells(struct device_node *np)
  77{
  78	const __be32 *ip;
 
  79
  80	do {
  81		if (np->parent)
  82			np = np->parent;
  83		ip = of_get_property(np, "#size-cells", NULL);
  84		if (ip)
  85			return be32_to_cpup(ip);
  86	} while (np->parent);
  87	/* No #size-cells property for the root node */
  88	return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
  89}
  90EXPORT_SYMBOL(of_n_size_cells);
  91
  92#ifdef CONFIG_NUMA
  93int __weak of_node_to_nid(struct device_node *np)
  94{
  95	return NUMA_NO_NODE;
 
 
  96}
  97#endif
  98
  99#ifndef CONFIG_OF_DYNAMIC
 100static void of_node_release(struct kobject *kobj)
 
 
 
 
 101{
 102	/* Without CONFIG_OF_DYNAMIC, no nodes gets freed */
 
 
 
 
 
 
 
 
 
 
 
 
 
 103}
 104#endif /* CONFIG_OF_DYNAMIC */
 105
 106struct kobj_type of_node_ktype = {
 107	.release = of_node_release,
 108};
 
 109
 110static ssize_t of_node_property_read(struct file *filp, struct kobject *kobj,
 111				struct bin_attribute *bin_attr, char *buf,
 112				loff_t offset, size_t count)
 113{
 114	struct property *pp = container_of(bin_attr, struct property, attr);
 115	return memory_read_from_buffer(buf, count, &offset, pp->value, pp->length);
 116}
 
 117
 118/* always return newly allocated name, caller must free after use */
 119static const char *safe_name(struct kobject *kobj, const char *orig_name)
 120{
 121	const char *name = orig_name;
 122	struct kernfs_node *kn;
 123	int i = 0;
 124
 125	/* don't be a hero. After 16 tries give up */
 126	while (i < 16 && (kn = sysfs_get_dirent(kobj->sd, name))) {
 127		sysfs_put(kn);
 128		if (name != orig_name)
 129			kfree(name);
 130		name = kasprintf(GFP_KERNEL, "%s#%i", orig_name, ++i);
 
 
 
 
 131	}
 132
 133	if (name == orig_name) {
 134		name = kstrdup(orig_name, GFP_KERNEL);
 135	} else {
 136		pr_warn("Duplicate name in %s, renamed to \"%s\"\n",
 137			kobject_name(kobj), name);
 138	}
 139	return name;
 140}
 141
 142int __of_add_property_sysfs(struct device_node *np, struct property *pp)
 143{
 144	int rc;
 
 145
 146	/* Important: Don't leak passwords */
 147	bool secure = strncmp(pp->name, "security-", 9) == 0;
 
 148
 149	if (!IS_ENABLED(CONFIG_SYSFS))
 150		return 0;
 
 
 
 
 151
 152	if (!of_kset || !of_node_is_attached(np))
 153		return 0;
 154
 155	sysfs_bin_attr_init(&pp->attr);
 156	pp->attr.attr.name = safe_name(&np->kobj, pp->name);
 157	pp->attr.attr.mode = secure ? S_IRUSR : S_IRUGO;
 158	pp->attr.size = secure ? 0 : pp->length;
 159	pp->attr.read = of_node_property_read;
 160
 161	rc = sysfs_create_bin_file(&np->kobj, &pp->attr);
 162	WARN(rc, "error adding attribute %s to node %s\n", pp->name, np->full_name);
 163	return rc;
 164}
 165
 166int __of_attach_node_sysfs(struct device_node *np)
 
 
 
 167{
 168	const char *name;
 169	struct kobject *parent;
 170	struct property *pp;
 171	int rc;
 172
 173	if (!IS_ENABLED(CONFIG_SYSFS))
 174		return 0;
 175
 176	if (!of_kset)
 177		return 0;
 178
 179	np->kobj.kset = of_kset;
 180	if (!np->parent) {
 181		/* Nodes without parents are new top level trees */
 182		name = safe_name(&of_kset->kobj, "base");
 183		parent = NULL;
 184	} else {
 185		name = safe_name(&np->parent->kobj, kbasename(np->full_name));
 186		parent = &np->parent->kobj;
 187	}
 188	if (!name)
 189		return -ENOMEM;
 190	rc = kobject_add(&np->kobj, parent, "%s", name);
 191	kfree(name);
 192	if (rc)
 193		return rc;
 194
 195	for_each_property_of_node(np, pp)
 196		__of_add_property_sysfs(np, pp);
 197
 198	return 0;
 
 
 199}
 200
 201void __init of_core_init(void)
 202{
 203	struct device_node *np;
 204
 
 
 205	/* Create the kset, and register existing nodes */
 206	mutex_lock(&of_mutex);
 207	of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
 208	if (!of_kset) {
 209		mutex_unlock(&of_mutex);
 210		pr_err("failed to register existing nodes\n");
 211		return;
 212	}
 213	for_each_of_allnodes(np)
 214		__of_attach_node_sysfs(np);
 
 
 
 215	mutex_unlock(&of_mutex);
 216
 217	/* Symlink in /proc as required by userspace ABI */
 218	if (of_root)
 219		proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
 220}
 221
 222static struct property *__of_find_property(const struct device_node *np,
 223					   const char *name, int *lenp)
 224{
 225	struct property *pp;
 226
 227	if (!np)
 228		return NULL;
 229
 230	for (pp = np->properties; pp; pp = pp->next) {
 231		if (of_prop_cmp(pp->name, name) == 0) {
 232			if (lenp)
 233				*lenp = pp->length;
 234			break;
 235		}
 236	}
 237
 238	return pp;
 239}
 240
 241struct property *of_find_property(const struct device_node *np,
 242				  const char *name,
 243				  int *lenp)
 244{
 245	struct property *pp;
 246	unsigned long flags;
 247
 248	raw_spin_lock_irqsave(&devtree_lock, flags);
 249	pp = __of_find_property(np, name, lenp);
 250	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 251
 252	return pp;
 253}
 254EXPORT_SYMBOL(of_find_property);
 255
 256struct device_node *__of_find_all_nodes(struct device_node *prev)
 257{
 258	struct device_node *np;
 259	if (!prev) {
 260		np = of_root;
 261	} else if (prev->child) {
 262		np = prev->child;
 263	} else {
 264		/* Walk back up looking for a sibling, or the end of the structure */
 265		np = prev;
 266		while (np->parent && !np->sibling)
 267			np = np->parent;
 268		np = np->sibling; /* Might be null at the end of the tree */
 269	}
 270	return np;
 271}
 272
 273/**
 274 * of_find_all_nodes - Get next node in global list
 275 * @prev:	Previous node or NULL to start iteration
 276 *		of_node_put() will be called on it
 277 *
 278 * Returns a node pointer with refcount incremented, use
 279 * of_node_put() on it when done.
 280 */
 281struct device_node *of_find_all_nodes(struct device_node *prev)
 282{
 283	struct device_node *np;
 284	unsigned long flags;
 285
 286	raw_spin_lock_irqsave(&devtree_lock, flags);
 287	np = __of_find_all_nodes(prev);
 288	of_node_get(np);
 289	of_node_put(prev);
 290	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 291	return np;
 292}
 293EXPORT_SYMBOL(of_find_all_nodes);
 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,
 300			      const char *name, int *lenp)
 301{
 302	struct property *pp = __of_find_property(np, name, lenp);
 303
 304	return pp ? pp->value : NULL;
 305}
 306
 307/*
 308 * Find a property with a given name for a given node
 309 * and return the value.
 310 */
 311const void *of_get_property(const struct device_node *np, const char *name,
 312			    int *lenp)
 313{
 314	struct property *pp = of_find_property(np, name, lenp);
 315
 316	return pp ? pp->value : NULL;
 317}
 318EXPORT_SYMBOL(of_get_property);
 319
 320/*
 321 * arch_match_cpu_phys_id - Match the given logical CPU and physical id
 322 *
 323 * @cpu: logical cpu index of a core/thread
 324 * @phys_id: physical identifier of a core/thread
 325 *
 326 * CPU logical to physical index mapping is architecture specific.
 327 * However this __weak function provides a default match of physical
 328 * id to logical cpu index. phys_id provided here is usually values read
 329 * from the device tree which must match the hardware internal registers.
 330 *
 331 * Returns true if the physical identifier and the logical cpu index
 332 * correspond to the same core/thread, false otherwise.
 333 */
 334bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
 335{
 336	return (u32)phys_id == cpu;
 337}
 338
 339/**
 340 * Checks if the given "prop_name" property holds the physical id of the
 341 * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
 342 * NULL, local thread number within the core is returned in it.
 343 */
 344static bool __of_find_n_match_cpu_property(struct device_node *cpun,
 345			const char *prop_name, int cpu, unsigned int *thread)
 346{
 347	const __be32 *cell;
 348	int ac, prop_len, tid;
 349	u64 hwid;
 350
 351	ac = of_n_addr_cells(cpun);
 352	cell = of_get_property(cpun, prop_name, &prop_len);
 353	if (!cell || !ac)
 354		return false;
 355	prop_len /= sizeof(*cell) * ac;
 356	for (tid = 0; tid < prop_len; tid++) {
 357		hwid = of_read_number(cell, ac);
 358		if (arch_match_cpu_phys_id(cpu, hwid)) {
 359			if (thread)
 360				*thread = tid;
 361			return true;
 362		}
 363		cell += ac;
 364	}
 365	return false;
 366}
 367
 368/*
 369 * arch_find_n_match_cpu_physical_id - See if the given device node is
 370 * for the cpu corresponding to logical cpu 'cpu'.  Return true if so,
 371 * else false.  If 'thread' is non-NULL, the local thread number within the
 372 * core is returned in it.
 373 */
 374bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
 375					      int cpu, unsigned int *thread)
 376{
 377	/* Check for non-standard "ibm,ppc-interrupt-server#s" property
 378	 * for thread ids on PowerPC. If it doesn't exist fallback to
 379	 * standard "reg" property.
 380	 */
 381	if (IS_ENABLED(CONFIG_PPC) &&
 382	    __of_find_n_match_cpu_property(cpun,
 383					   "ibm,ppc-interrupt-server#s",
 384					   cpu, thread))
 385		return true;
 386
 387	return __of_find_n_match_cpu_property(cpun, "reg", cpu, thread);
 388}
 389
 390/**
 391 * of_get_cpu_node - Get device node associated with the given logical CPU
 392 *
 393 * @cpu: CPU number(logical index) for which device node is required
 394 * @thread: if not NULL, local thread number within the physical core is
 395 *          returned
 396 *
 397 * The main purpose of this function is to retrieve the device node for the
 398 * given logical CPU index. It should be used to initialize the of_node in
 399 * cpu device. Once of_node in cpu device is populated, all the further
 400 * references can use that instead.
 401 *
 402 * CPU logical to physical index mapping is architecture specific and is built
 403 * before booting secondary cores. This function uses arch_match_cpu_phys_id
 404 * which can be overridden by architecture specific implementation.
 405 *
 406 * Returns a node pointer for the logical cpu with refcount incremented, use
 407 * of_node_put() on it when done. Returns NULL if not found.
 408 */
 409struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
 410{
 411	struct device_node *cpun;
 412
 413	for_each_node_by_type(cpun, "cpu") {
 414		if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
 415			return cpun;
 416	}
 417	return NULL;
 418}
 419EXPORT_SYMBOL(of_get_cpu_node);
 420
 421/**
 422 * __of_device_is_compatible() - Check if the node matches given constraints
 423 * @device: pointer to node
 424 * @compat: required compatible string, NULL or "" for any match
 425 * @type: required device_type value, NULL or "" for any match
 426 * @name: required node name, NULL or "" for any match
 427 *
 428 * Checks if the given @compat, @type and @name strings match the
 429 * properties of the given @device. A constraints can be skipped by
 430 * passing NULL or an empty string as the constraint.
 431 *
 432 * Returns 0 for no match, and a positive integer on match. The return
 433 * value is a relative score with larger values indicating better
 434 * matches. The score is weighted for the most specific compatible value
 435 * to get the highest score. Matching type is next, followed by matching
 436 * name. Practically speaking, this results in the following priority
 437 * order for matches:
 438 *
 439 * 1. specific compatible && type && name
 440 * 2. specific compatible && type
 441 * 3. specific compatible && name
 442 * 4. specific compatible
 443 * 5. general compatible && type && name
 444 * 6. general compatible && type
 445 * 7. general compatible && name
 446 * 8. general compatible
 447 * 9. type && name
 448 * 10. type
 449 * 11. name
 450 */
 451static int __of_device_is_compatible(const struct device_node *device,
 452				     const char *compat, const char *type, const char *name)
 453{
 454	struct property *prop;
 455	const char *cp;
 456	int index = 0, score = 0;
 457
 458	/* Compatible match has highest priority */
 459	if (compat && compat[0]) {
 460		prop = __of_find_property(device, "compatible", NULL);
 461		for (cp = of_prop_next_string(prop, NULL); cp;
 462		     cp = of_prop_next_string(prop, cp), index++) {
 463			if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
 464				score = INT_MAX/2 - (index << 2);
 465				break;
 466			}
 467		}
 468		if (!score)
 469			return 0;
 470	}
 471
 472	/* Matching type is better than matching name */
 473	if (type && type[0]) {
 474		if (!device->type || of_node_cmp(type, device->type))
 475			return 0;
 476		score += 2;
 477	}
 478
 479	/* Matching name is a bit better than not */
 480	if (name && name[0]) {
 481		if (!device->name || of_node_cmp(name, device->name))
 482			return 0;
 483		score++;
 484	}
 485
 486	return score;
 487}
 488
 489/** Checks if the given "compat" string matches one of the strings in
 490 * the device's "compatible" property
 491 */
 492int of_device_is_compatible(const struct device_node *device,
 493		const char *compat)
 494{
 495	unsigned long flags;
 496	int res;
 497
 498	raw_spin_lock_irqsave(&devtree_lock, flags);
 499	res = __of_device_is_compatible(device, compat, NULL, NULL);
 500	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 501	return res;
 502}
 503EXPORT_SYMBOL(of_device_is_compatible);
 504
 505/** Checks if the device is compatible with any of the entries in
 506 *  a NULL terminated array of strings. Returns the best match
 507 *  score or 0.
 508 */
 509int of_device_compatible_match(struct device_node *device,
 510			       const char *const *compat)
 511{
 512	unsigned int tmp, score = 0;
 513
 514	if (!compat)
 515		return 0;
 516
 517	while (*compat) {
 518		tmp = of_device_is_compatible(device, *compat);
 519		if (tmp > score)
 520			score = tmp;
 521		compat++;
 522	}
 523
 524	return score;
 525}
 
 526
 527/**
 528 * of_machine_is_compatible - Test root of device tree for a given compatible value
 529 * @compat: compatible string to look for in root node's compatible property.
 530 *
 531 * Returns a positive integer if the root node has the given value in its
 532 * compatible property.
 533 */
 534int of_machine_is_compatible(const char *compat)
 535{
 536	struct device_node *root;
 537	int rc = 0;
 538
 539	root = of_find_node_by_path("/");
 540	if (root) {
 541		rc = of_device_is_compatible(root, compat);
 542		of_node_put(root);
 543	}
 544	return rc;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 545}
 546EXPORT_SYMBOL(of_machine_is_compatible);
 547
 548/**
 549 *  __of_device_is_available - check if a device is available for use
 550 *
 551 *  @device: Node to check for availability, with locks already held
 552 *
 553 *  Returns true if the status property is absent or set to "okay" or "ok",
 554 *  false otherwise
 555 */
 556static bool __of_device_is_available(const struct device_node *device)
 557{
 558	const char *status;
 559	int statlen;
 560
 561	if (!device)
 562		return false;
 563
 564	status = __of_get_property(device, "status", &statlen);
 565	if (status == NULL)
 566		return true;
 567
 568	if (statlen > 0) {
 569		if (!strcmp(status, "okay") || !strcmp(status, "ok"))
 570			return true;
 571	}
 
 
 
 
 
 
 572
 573	return false;
 574}
 575
 576/**
 577 *  of_device_is_available - check if a device is available for use
 578 *
 579 *  @device: Node to check for availability
 580 *
 581 *  Returns true if the status property is absent or set to "okay" or "ok",
 582 *  false otherwise
 583 */
 584bool of_device_is_available(const struct device_node *device)
 585{
 586	unsigned long flags;
 587	bool res;
 588
 589	raw_spin_lock_irqsave(&devtree_lock, flags);
 590	res = __of_device_is_available(device);
 591	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 592	return res;
 593
 594}
 595EXPORT_SYMBOL(of_device_is_available);
 596
 597/**
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 598 *  of_device_is_big_endian - check if a device has BE registers
 599 *
 600 *  @device: Node to check for endianness
 601 *
 602 *  Returns true if the device has a "big-endian" property, or if the kernel
 603 *  was compiled for BE *and* the device has a "native-endian" property.
 604 *  Returns false otherwise.
 605 *
 606 *  Callers would nominally use ioread32be/iowrite32be if
 607 *  of_device_is_big_endian() == true, or readl/writel otherwise.
 608 */
 609bool of_device_is_big_endian(const struct device_node *device)
 610{
 611	if (of_property_read_bool(device, "big-endian"))
 612		return true;
 613	if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
 614	    of_property_read_bool(device, "native-endian"))
 615		return true;
 616	return false;
 617}
 618EXPORT_SYMBOL(of_device_is_big_endian);
 619
 620/**
 621 *	of_get_parent - Get a node's parent if any
 622 *	@node:	Node to get parent
 623 *
 624 *	Returns a node pointer with refcount incremented, use
 625 *	of_node_put() on it when done.
 626 */
 627struct device_node *of_get_parent(const struct device_node *node)
 628{
 629	struct device_node *np;
 630	unsigned long flags;
 631
 632	if (!node)
 633		return NULL;
 634
 635	raw_spin_lock_irqsave(&devtree_lock, flags);
 636	np = of_node_get(node->parent);
 637	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 638	return np;
 639}
 640EXPORT_SYMBOL(of_get_parent);
 641
 642/**
 643 *	of_get_next_parent - Iterate to a node's parent
 644 *	@node:	Node to get parent of
 645 *
 646 *	This is like of_get_parent() except that it drops the
 647 *	refcount on the passed node, making it suitable for iterating
 648 *	through a node's parents.
 649 *
 650 *	Returns a node pointer with refcount incremented, use
 651 *	of_node_put() on it when done.
 652 */
 653struct device_node *of_get_next_parent(struct device_node *node)
 654{
 655	struct device_node *parent;
 656	unsigned long flags;
 657
 658	if (!node)
 659		return NULL;
 660
 661	raw_spin_lock_irqsave(&devtree_lock, flags);
 662	parent = of_node_get(node->parent);
 663	of_node_put(node);
 664	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 665	return parent;
 666}
 667EXPORT_SYMBOL(of_get_next_parent);
 668
 669static struct device_node *__of_get_next_child(const struct device_node *node,
 670						struct device_node *prev)
 671{
 672	struct device_node *next;
 673
 674	if (!node)
 675		return NULL;
 676
 677	next = prev ? prev->sibling : node->child;
 678	for (; next; next = next->sibling)
 679		if (of_node_get(next))
 680			break;
 681	of_node_put(prev);
 682	return next;
 683}
 684#define __for_each_child_of_node(parent, child) \
 685	for (child = __of_get_next_child(parent, NULL); child != NULL; \
 686	     child = __of_get_next_child(parent, child))
 687
 688/**
 689 *	of_get_next_child - Iterate a node childs
 690 *	@node:	parent node
 691 *	@prev:	previous child of the parent node, or NULL to get first
 692 *
 693 *	Returns a node pointer with refcount incremented, use of_node_put() on
 694 *	it when done. Returns NULL when prev is the last child. Decrements the
 695 *	refcount of prev.
 696 */
 697struct device_node *of_get_next_child(const struct device_node *node,
 698	struct device_node *prev)
 699{
 700	struct device_node *next;
 701	unsigned long flags;
 702
 703	raw_spin_lock_irqsave(&devtree_lock, flags);
 704	next = __of_get_next_child(node, prev);
 705	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 706	return next;
 707}
 708EXPORT_SYMBOL(of_get_next_child);
 709
 710/**
 711 *	of_get_next_available_child - Find the next available child node
 712 *	@node:	parent node
 713 *	@prev:	previous child of the parent node, or NULL to get first
 
 714 *
 715 *      This function is like of_get_next_child(), except that it
 716 *      automatically skips any disabled nodes (i.e. status = "disabled").
 
 
 
 717 */
 718struct device_node *of_get_next_available_child(const struct device_node *node,
 719	struct device_node *prev)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 720{
 721	struct device_node *next;
 722	unsigned long flags;
 723
 724	if (!node)
 725		return NULL;
 726
 727	raw_spin_lock_irqsave(&devtree_lock, flags);
 728	next = prev ? prev->sibling : node->child;
 729	for (; next; next = next->sibling) {
 730		if (!__of_device_is_available(next))
 731			continue;
 732		if (of_node_get(next))
 733			break;
 734	}
 735	of_node_put(prev);
 736	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 737	return next;
 738}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 739EXPORT_SYMBOL(of_get_next_available_child);
 740
 741/**
 742 *	of_get_child_by_name - Find the child node by name for a given parent
 743 *	@node:	parent node
 744 *	@name:	child name to look for.
 745 *
 746 *      This function looks for child node for given matching name
 747 *
 748 *	Returns a node pointer if found, with refcount incremented, use
 749 *	of_node_put() on it when done.
 750 *	Returns NULL if node is not found.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 751 */
 752struct device_node *of_get_child_by_name(const struct device_node *node,
 753				const char *name)
 754{
 755	struct device_node *child;
 756
 757	for_each_child_of_node(node, child)
 758		if (child->name && (of_node_cmp(child->name, name) == 0))
 759			break;
 760	return child;
 761}
 762EXPORT_SYMBOL(of_get_child_by_name);
 763
 764static struct device_node *__of_find_node_by_path(struct device_node *parent,
 765						const char *path)
 766{
 767	struct device_node *child;
 768	int len;
 769
 770	len = strcspn(path, "/:");
 771	if (!len)
 772		return NULL;
 773
 774	__for_each_child_of_node(parent, child) {
 775		const char *name = strrchr(child->full_name, '/');
 776		if (WARN(!name, "malformed device_node %s\n", child->full_name))
 777			continue;
 778		name++;
 779		if (strncmp(path, name, len) == 0 && (strlen(name) == len))
 780			return child;
 781	}
 782	return NULL;
 783}
 784
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 785/**
 786 *	of_find_node_opts_by_path - Find a node matching a full OF path
 787 *	@path: Either the full path to match, or if the path does not
 788 *	       start with '/', the name of a property of the /aliases
 789 *	       node (an alias).  In the case of an alias, the node
 790 *	       matching the alias' value will be returned.
 791 *	@opts: Address of a pointer into which to store the start of
 792 *	       an options string appended to the end of the path with
 793 *	       a ':' separator.
 794 *
 795 *	Valid paths:
 796 *		/foo/bar	Full path
 797 *		foo		Valid alias
 798 *		foo/bar		Valid alias + relative path
 799 *
 800 *	Returns a node pointer with refcount incremented, use
 801 *	of_node_put() on it when done.
 802 */
 803struct device_node *of_find_node_opts_by_path(const char *path, const char **opts)
 804{
 805	struct device_node *np = NULL;
 806	struct property *pp;
 807	unsigned long flags;
 808	const char *separator = strchr(path, ':');
 809
 810	if (opts)
 811		*opts = separator ? separator + 1 : NULL;
 812
 813	if (strcmp(path, "/") == 0)
 814		return of_node_get(of_root);
 815
 816	/* The path could begin with an alias */
 817	if (*path != '/') {
 818		int len;
 819		const char *p = separator;
 820
 821		if (!p)
 822			p = strchrnul(path, '/');
 823		len = p - path;
 824
 825		/* of_aliases must not be NULL */
 826		if (!of_aliases)
 827			return NULL;
 828
 829		for_each_property_of_node(of_aliases, pp) {
 830			if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
 831				np = of_find_node_by_path(pp->value);
 832				break;
 833			}
 834		}
 835		if (!np)
 836			return NULL;
 837		path = p;
 838	}
 839
 840	/* Step down the tree matching path components */
 841	raw_spin_lock_irqsave(&devtree_lock, flags);
 842	if (!np)
 843		np = of_node_get(of_root);
 844	while (np && *path == '/') {
 845		path++; /* Increment past '/' delimiter */
 846		np = __of_find_node_by_path(np, path);
 847		path = strchrnul(path, '/');
 848		if (separator && separator < path)
 849			break;
 850	}
 851	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 852	return np;
 853}
 854EXPORT_SYMBOL(of_find_node_opts_by_path);
 855
 856/**
 857 *	of_find_node_by_name - Find a node by its "name" property
 858 *	@from:	The node to start searching from or NULL, the node
 859 *		you pass will not be searched, only the next one
 860 *		will; typically, you pass what the previous call
 861 *		returned. of_node_put() will be called on it
 862 *	@name:	The name string to match against
 863 *
 864 *	Returns a node pointer with refcount incremented, use
 865 *	of_node_put() on it when done.
 866 */
 867struct device_node *of_find_node_by_name(struct device_node *from,
 868	const char *name)
 869{
 870	struct device_node *np;
 871	unsigned long flags;
 872
 873	raw_spin_lock_irqsave(&devtree_lock, flags);
 874	for_each_of_allnodes_from(from, np)
 875		if (np->name && (of_node_cmp(np->name, name) == 0)
 876		    && of_node_get(np))
 877			break;
 878	of_node_put(from);
 879	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 880	return np;
 881}
 882EXPORT_SYMBOL(of_find_node_by_name);
 883
 884/**
 885 *	of_find_node_by_type - Find a node by its "device_type" property
 886 *	@from:	The node to start searching from, or NULL to start searching
 887 *		the entire device tree. The node you pass will not be
 888 *		searched, only the next one will; typically, you pass
 889 *		what the previous call returned. of_node_put() will be
 890 *		called on from for you.
 891 *	@type:	The type string to match against
 892 *
 893 *	Returns a node pointer with refcount incremented, use
 894 *	of_node_put() on it when done.
 895 */
 896struct device_node *of_find_node_by_type(struct device_node *from,
 897	const char *type)
 898{
 899	struct device_node *np;
 900	unsigned long flags;
 901
 902	raw_spin_lock_irqsave(&devtree_lock, flags);
 903	for_each_of_allnodes_from(from, np)
 904		if (np->type && (of_node_cmp(np->type, type) == 0)
 905		    && of_node_get(np))
 906			break;
 907	of_node_put(from);
 908	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 909	return np;
 910}
 911EXPORT_SYMBOL(of_find_node_by_type);
 912
 913/**
 914 *	of_find_compatible_node - Find a node based on type and one of the
 915 *                                tokens in its "compatible" property
 916 *	@from:		The node to start searching from or NULL, the node
 917 *			you pass will not be searched, only the next one
 918 *			will; typically, you pass what the previous call
 919 *			returned. of_node_put() will be called on it
 920 *	@type:		The type string to match "device_type" or NULL to ignore
 921 *	@compatible:	The string to match to one of the tokens in the device
 922 *			"compatible" list.
 923 *
 924 *	Returns a node pointer with refcount incremented, use
 925 *	of_node_put() on it when done.
 926 */
 927struct device_node *of_find_compatible_node(struct device_node *from,
 928	const char *type, const char *compatible)
 929{
 930	struct device_node *np;
 931	unsigned long flags;
 932
 933	raw_spin_lock_irqsave(&devtree_lock, flags);
 934	for_each_of_allnodes_from(from, np)
 935		if (__of_device_is_compatible(np, compatible, type, NULL) &&
 936		    of_node_get(np))
 937			break;
 938	of_node_put(from);
 939	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 940	return np;
 941}
 942EXPORT_SYMBOL(of_find_compatible_node);
 943
 944/**
 945 *	of_find_node_with_property - Find a node which has a property with
 946 *                                   the given name.
 947 *	@from:		The node to start searching from or NULL, the node
 948 *			you pass will not be searched, only the next one
 949 *			will; typically, you pass what the previous call
 950 *			returned. of_node_put() will be called on it
 951 *	@prop_name:	The name of the property to look for.
 952 *
 953 *	Returns a node pointer with refcount incremented, use
 954 *	of_node_put() on it when done.
 955 */
 956struct device_node *of_find_node_with_property(struct device_node *from,
 957	const char *prop_name)
 958{
 959	struct device_node *np;
 960	struct property *pp;
 961	unsigned long flags;
 962
 963	raw_spin_lock_irqsave(&devtree_lock, flags);
 964	for_each_of_allnodes_from(from, np) {
 965		for (pp = np->properties; pp; pp = pp->next) {
 966			if (of_prop_cmp(pp->name, prop_name) == 0) {
 967				of_node_get(np);
 968				goto out;
 969			}
 970		}
 971	}
 972out:
 973	of_node_put(from);
 974	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 975	return np;
 976}
 977EXPORT_SYMBOL(of_find_node_with_property);
 978
 979static
 980const struct of_device_id *__of_match_node(const struct of_device_id *matches,
 981					   const struct device_node *node)
 982{
 983	const struct of_device_id *best_match = NULL;
 984	int score, best_score = 0;
 985
 986	if (!matches)
 987		return NULL;
 988
 989	for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
 990		score = __of_device_is_compatible(node, matches->compatible,
 991						  matches->type, matches->name);
 992		if (score > best_score) {
 993			best_match = matches;
 994			best_score = score;
 995		}
 996	}
 997
 998	return best_match;
 999}
1000
1001/**
1002 * of_match_node - Tell if a device_node has a matching of_match structure
1003 *	@matches:	array of of device match structures to search in
1004 *	@node:		the of device structure to match against
1005 *
1006 *	Low level utility function used by device matching.
1007 */
1008const struct of_device_id *of_match_node(const struct of_device_id *matches,
1009					 const struct device_node *node)
1010{
1011	const struct of_device_id *match;
1012	unsigned long flags;
1013
1014	raw_spin_lock_irqsave(&devtree_lock, flags);
1015	match = __of_match_node(matches, node);
1016	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1017	return match;
1018}
1019EXPORT_SYMBOL(of_match_node);
1020
1021/**
1022 *	of_find_matching_node_and_match - Find a node based on an of_device_id
1023 *					  match table.
1024 *	@from:		The node to start searching from or NULL, the node
1025 *			you pass will not be searched, only the next one
1026 *			will; typically, you pass what the previous call
1027 *			returned. of_node_put() will be called on it
1028 *	@matches:	array of of device match structures to search in
1029 *	@match		Updated to point at the matches entry which matched
1030 *
1031 *	Returns a node pointer with refcount incremented, use
1032 *	of_node_put() on it when done.
1033 */
1034struct device_node *of_find_matching_node_and_match(struct device_node *from,
1035					const struct of_device_id *matches,
1036					const struct of_device_id **match)
1037{
1038	struct device_node *np;
1039	const struct of_device_id *m;
1040	unsigned long flags;
1041
1042	if (match)
1043		*match = NULL;
1044
1045	raw_spin_lock_irqsave(&devtree_lock, flags);
1046	for_each_of_allnodes_from(from, np) {
1047		m = __of_match_node(matches, np);
1048		if (m && of_node_get(np)) {
1049			if (match)
1050				*match = m;
1051			break;
1052		}
1053	}
1054	of_node_put(from);
1055	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1056	return np;
1057}
1058EXPORT_SYMBOL(of_find_matching_node_and_match);
1059
1060/**
1061 * of_modalias_node - Lookup appropriate modalias for a device node
 
1062 * @node:	pointer to a device tree node
1063 * @modalias:	Pointer to buffer that modalias value will be copied into
1064 * @len:	Length of modalias value
1065 *
1066 * Based on the value of the compatible property, this routine will attempt
1067 * to choose an appropriate modalias value for a particular device tree node.
1068 * It does this by stripping the manufacturer prefix (as delimited by a ',')
1069 * from the first entry in the compatible list property.
1070 *
1071 * This routine returns 0 on success, <0 on failure.
 
 
 
1072 */
1073int of_modalias_node(struct device_node *node, char *modalias, int len)
1074{
1075	const char *compatible, *p;
1076	int cplen;
1077
1078	compatible = of_get_property(node, "compatible", &cplen);
1079	if (!compatible || strlen(compatible) > cplen)
1080		return -ENODEV;
1081	p = strchr(compatible, ',');
1082	strlcpy(modalias, p ? p + 1 : compatible, len);
1083	return 0;
1084}
1085EXPORT_SYMBOL_GPL(of_modalias_node);
1086
1087/**
1088 * of_find_node_by_phandle - Find a node given a phandle
1089 * @handle:	phandle of the node to find
1090 *
1091 * Returns a node pointer with refcount incremented, use
1092 * of_node_put() on it when done.
1093 */
1094struct device_node *of_find_node_by_phandle(phandle handle)
1095{
1096	struct device_node *np;
1097	unsigned long flags;
 
1098
1099	if (!handle)
1100		return NULL;
1101
 
 
1102	raw_spin_lock_irqsave(&devtree_lock, flags);
1103	for_each_of_allnodes(np)
1104		if (np->phandle == handle)
1105			break;
 
 
 
 
 
 
 
 
 
 
 
1106	of_node_get(np);
1107	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1108	return np;
1109}
1110EXPORT_SYMBOL(of_find_node_by_phandle);
1111
1112/**
1113 * of_property_count_elems_of_size - Count the number of elements in a property
1114 *
1115 * @np:		device node from which the property value is to be read.
1116 * @propname:	name of the property to be searched.
1117 * @elem_size:	size of the individual element
1118 *
1119 * Search for a property in a device node and count the number of elements of
1120 * size elem_size in it. Returns number of elements on sucess, -EINVAL if the
1121 * property does not exist or its length does not match a multiple of elem_size
1122 * and -ENODATA if the property does not have a value.
1123 */
1124int of_property_count_elems_of_size(const struct device_node *np,
1125				const char *propname, int elem_size)
1126{
1127	struct property *prop = of_find_property(np, propname, NULL);
1128
1129	if (!prop)
1130		return -EINVAL;
1131	if (!prop->value)
1132		return -ENODATA;
1133
1134	if (prop->length % elem_size != 0) {
1135		pr_err("size of %s in node %s is not a multiple of %d\n",
1136		       propname, np->full_name, elem_size);
1137		return -EINVAL;
1138	}
1139
1140	return prop->length / elem_size;
1141}
1142EXPORT_SYMBOL_GPL(of_property_count_elems_of_size);
1143
1144/**
1145 * of_find_property_value_of_size
1146 *
1147 * @np:		device node from which the property value is to be read.
1148 * @propname:	name of the property to be searched.
1149 * @min:	minimum allowed length of property value
1150 * @max:	maximum allowed length of property value (0 means unlimited)
1151 * @len:	if !=NULL, actual length is written to here
1152 *
1153 * Search for a property in a device node and valid the requested size.
1154 * Returns the property value on success, -EINVAL if the property does not
1155 *  exist, -ENODATA if property does not have a value, and -EOVERFLOW if the
1156 * property data is too small or too large.
1157 *
1158 */
1159static void *of_find_property_value_of_size(const struct device_node *np,
1160			const char *propname, u32 min, u32 max, size_t *len)
1161{
1162	struct property *prop = of_find_property(np, propname, NULL);
1163
1164	if (!prop)
1165		return ERR_PTR(-EINVAL);
1166	if (!prop->value)
1167		return ERR_PTR(-ENODATA);
1168	if (prop->length < min)
1169		return ERR_PTR(-EOVERFLOW);
1170	if (max && prop->length > max)
1171		return ERR_PTR(-EOVERFLOW);
1172
1173	if (len)
1174		*len = prop->length;
1175
1176	return prop->value;
1177}
1178
1179/**
1180 * of_property_read_u32_index - Find and read a u32 from a multi-value property.
1181 *
1182 * @np:		device node from which the property value is to be read.
1183 * @propname:	name of the property to be searched.
1184 * @index:	index of the u32 in the list of values
1185 * @out_value:	pointer to return value, modified only if no error.
1186 *
1187 * Search for a property in a device node and read nth 32-bit value from
1188 * it. Returns 0 on success, -EINVAL if the property does not exist,
1189 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1190 * property data isn't large enough.
1191 *
1192 * The out_value is modified only if a valid u32 value can be decoded.
1193 */
1194int of_property_read_u32_index(const struct device_node *np,
1195				       const char *propname,
1196				       u32 index, u32 *out_value)
1197{
1198	const u32 *val = of_find_property_value_of_size(np, propname,
1199					((index + 1) * sizeof(*out_value)),
1200					0,
1201					NULL);
1202
1203	if (IS_ERR(val))
1204		return PTR_ERR(val);
1205
1206	*out_value = be32_to_cpup(((__be32 *)val) + index);
1207	return 0;
1208}
1209EXPORT_SYMBOL_GPL(of_property_read_u32_index);
1210
1211/**
1212 * of_property_read_variable_u8_array - Find and read an array of u8 from a
1213 * property, with bounds on the minimum and maximum array size.
1214 *
1215 * @np:		device node from which the property value is to be read.
1216 * @propname:	name of the property to be searched.
1217 * @out_values:	pointer to return value, modified only if return value is 0.
1218 * @sz_min:	minimum number of array elements to read
1219 * @sz_max:	maximum number of array elements to read, if zero there is no
1220 *		upper limit on the number of elements in the dts entry but only
1221 *		sz_min will be read.
1222 *
1223 * Search for a property in a device node and read 8-bit value(s) from
1224 * it. Returns number of elements read on success, -EINVAL if the property
1225 * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
1226 * if the property data is smaller than sz_min or longer than sz_max.
1227 *
1228 * dts entry of array should be like:
1229 *	property = /bits/ 8 <0x50 0x60 0x70>;
1230 *
1231 * The out_values is modified only if a valid u8 value can be decoded.
1232 */
1233int of_property_read_variable_u8_array(const struct device_node *np,
1234					const char *propname, u8 *out_values,
1235					size_t sz_min, size_t sz_max)
1236{
1237	size_t sz, count;
1238	const u8 *val = of_find_property_value_of_size(np, propname,
1239						(sz_min * sizeof(*out_values)),
1240						(sz_max * sizeof(*out_values)),
1241						&sz);
1242
1243	if (IS_ERR(val))
1244		return PTR_ERR(val);
1245
1246	if (!sz_max)
1247		sz = sz_min;
1248	else
1249		sz /= sizeof(*out_values);
1250
1251	count = sz;
1252	while (count--)
1253		*out_values++ = *val++;
1254
1255	return sz;
1256}
1257EXPORT_SYMBOL_GPL(of_property_read_variable_u8_array);
1258
1259/**
1260 * of_property_read_variable_u16_array - Find and read an array of u16 from a
1261 * property, with bounds on the minimum and maximum array size.
1262 *
1263 * @np:		device node from which the property value is to be read.
1264 * @propname:	name of the property to be searched.
1265 * @out_values:	pointer to return value, modified only if return value is 0.
1266 * @sz_min:	minimum number of array elements to read
1267 * @sz_max:	maximum number of array elements to read, if zero there is no
1268 *		upper limit on the number of elements in the dts entry but only
1269 *		sz_min will be read.
1270 *
1271 * Search for a property in a device node and read 16-bit value(s) from
1272 * it. Returns number of elements read on success, -EINVAL if the property
1273 * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
1274 * if the property data is smaller than sz_min or longer than sz_max.
1275 *
1276 * dts entry of array should be like:
1277 *	property = /bits/ 16 <0x5000 0x6000 0x7000>;
1278 *
1279 * The out_values is modified only if a valid u16 value can be decoded.
1280 */
1281int of_property_read_variable_u16_array(const struct device_node *np,
1282					const char *propname, u16 *out_values,
1283					size_t sz_min, size_t sz_max)
1284{
1285	size_t sz, count;
1286	const __be16 *val = of_find_property_value_of_size(np, propname,
1287						(sz_min * sizeof(*out_values)),
1288						(sz_max * sizeof(*out_values)),
1289						&sz);
1290
1291	if (IS_ERR(val))
1292		return PTR_ERR(val);
1293
1294	if (!sz_max)
1295		sz = sz_min;
1296	else
1297		sz /= sizeof(*out_values);
1298
1299	count = sz;
1300	while (count--)
1301		*out_values++ = be16_to_cpup(val++);
1302
1303	return sz;
1304}
1305EXPORT_SYMBOL_GPL(of_property_read_variable_u16_array);
1306
1307/**
1308 * of_property_read_variable_u32_array - Find and read an array of 32 bit
1309 * integers from a property, with bounds on the minimum and maximum array size.
1310 *
1311 * @np:		device node from which the property value is to be read.
1312 * @propname:	name of the property to be searched.
1313 * @out_values:	pointer to return value, modified only if return value is 0.
1314 * @sz_min:	minimum number of array elements to read
1315 * @sz_max:	maximum number of array elements to read, if zero there is no
1316 *		upper limit on the number of elements in the dts entry but only
1317 *		sz_min will be read.
1318 *
1319 * Search for a property in a device node and read 32-bit value(s) from
1320 * it. Returns number of elements read on success, -EINVAL if the property
1321 * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
1322 * if the property data is smaller than sz_min or longer than sz_max.
1323 *
1324 * The out_values is modified only if a valid u32 value can be decoded.
1325 */
1326int of_property_read_variable_u32_array(const struct device_node *np,
1327			       const char *propname, u32 *out_values,
1328			       size_t sz_min, size_t sz_max)
1329{
1330	size_t sz, count;
1331	const __be32 *val = of_find_property_value_of_size(np, propname,
1332						(sz_min * sizeof(*out_values)),
1333						(sz_max * sizeof(*out_values)),
1334						&sz);
1335
1336	if (IS_ERR(val))
1337		return PTR_ERR(val);
1338
1339	if (!sz_max)
1340		sz = sz_min;
1341	else
1342		sz /= sizeof(*out_values);
1343
1344	count = sz;
1345	while (count--)
1346		*out_values++ = be32_to_cpup(val++);
1347
1348	return sz;
1349}
1350EXPORT_SYMBOL_GPL(of_property_read_variable_u32_array);
1351
1352/**
1353 * of_property_read_u64 - Find and read a 64 bit integer from a property
1354 * @np:		device node from which the property value is to be read.
1355 * @propname:	name of the property to be searched.
1356 * @out_value:	pointer to return value, modified only if return value is 0.
1357 *
1358 * Search for a property in a device node and read a 64-bit value from
1359 * it. Returns 0 on success, -EINVAL if the property does not exist,
1360 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1361 * property data isn't large enough.
1362 *
1363 * The out_value is modified only if a valid u64 value can be decoded.
1364 */
1365int of_property_read_u64(const struct device_node *np, const char *propname,
1366			 u64 *out_value)
1367{
1368	const __be32 *val = of_find_property_value_of_size(np, propname,
1369						sizeof(*out_value),
1370						0,
1371						NULL);
1372
1373	if (IS_ERR(val))
1374		return PTR_ERR(val);
1375
1376	*out_value = of_read_number(val, 2);
1377	return 0;
1378}
1379EXPORT_SYMBOL_GPL(of_property_read_u64);
1380
1381/**
1382 * of_property_read_variable_u64_array - Find and read an array of 64 bit
1383 * integers from a property, with bounds on the minimum and maximum array size.
1384 *
1385 * @np:		device node from which the property value is to be read.
1386 * @propname:	name of the property to be searched.
1387 * @out_values:	pointer to return value, modified only if return value is 0.
1388 * @sz_min:	minimum number of array elements to read
1389 * @sz_max:	maximum number of array elements to read, if zero there is no
1390 *		upper limit on the number of elements in the dts entry but only
1391 *		sz_min will be read.
1392 *
1393 * Search for a property in a device node and read 64-bit value(s) from
1394 * it. Returns number of elements read on success, -EINVAL if the property
1395 * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
1396 * if the property data is smaller than sz_min or longer than sz_max.
1397 *
1398 * The out_values is modified only if a valid u64 value can be decoded.
1399 */
1400int of_property_read_variable_u64_array(const struct device_node *np,
1401			       const char *propname, u64 *out_values,
1402			       size_t sz_min, size_t sz_max)
1403{
1404	size_t sz, count;
1405	const __be32 *val = of_find_property_value_of_size(np, propname,
1406						(sz_min * sizeof(*out_values)),
1407						(sz_max * sizeof(*out_values)),
1408						&sz);
1409
1410	if (IS_ERR(val))
1411		return PTR_ERR(val);
1412
1413	if (!sz_max)
1414		sz = sz_min;
1415	else
1416		sz /= sizeof(*out_values);
1417
1418	count = sz;
1419	while (count--) {
1420		*out_values++ = of_read_number(val, 2);
1421		val += 2;
1422	}
1423
1424	return sz;
1425}
1426EXPORT_SYMBOL_GPL(of_property_read_variable_u64_array);
1427
1428/**
1429 * of_property_read_string - Find and read a string from a property
1430 * @np:		device node from which the property value is to be read.
1431 * @propname:	name of the property to be searched.
1432 * @out_string:	pointer to null terminated return string, modified only if
1433 *		return value is 0.
1434 *
1435 * Search for a property in a device tree node and retrieve a null
1436 * terminated string value (pointer to data, not a copy). Returns 0 on
1437 * success, -EINVAL if the property does not exist, -ENODATA if property
1438 * does not have a value, and -EILSEQ if the string is not null-terminated
1439 * within the length of the property data.
1440 *
1441 * The out_string pointer is modified only if a valid string can be decoded.
1442 */
1443int of_property_read_string(const struct device_node *np, const char *propname,
1444				const char **out_string)
1445{
1446	const struct property *prop = of_find_property(np, propname, NULL);
1447	if (!prop)
1448		return -EINVAL;
1449	if (!prop->value)
1450		return -ENODATA;
1451	if (strnlen(prop->value, prop->length) >= prop->length)
1452		return -EILSEQ;
1453	*out_string = prop->value;
1454	return 0;
1455}
1456EXPORT_SYMBOL_GPL(of_property_read_string);
1457
1458/**
1459 * of_property_match_string() - Find string in a list and return index
1460 * @np: pointer to node containing string list property
1461 * @propname: string list property name
1462 * @string: pointer to string to search for in string list
1463 *
1464 * This function searches a string list property and returns the index
1465 * of a specific string value.
1466 */
1467int of_property_match_string(const struct device_node *np, const char *propname,
1468			     const char *string)
1469{
1470	const struct property *prop = of_find_property(np, propname, NULL);
1471	size_t l;
1472	int i;
1473	const char *p, *end;
1474
1475	if (!prop)
1476		return -EINVAL;
1477	if (!prop->value)
1478		return -ENODATA;
1479
1480	p = prop->value;
1481	end = p + prop->length;
1482
1483	for (i = 0; p < end; i++, p += l) {
1484		l = strnlen(p, end - p) + 1;
1485		if (p + l > end)
1486			return -EILSEQ;
1487		pr_debug("comparing %s with %s\n", string, p);
1488		if (strcmp(string, p) == 0)
1489			return i; /* Found it; return index */
1490	}
1491	return -ENODATA;
1492}
1493EXPORT_SYMBOL_GPL(of_property_match_string);
1494
1495/**
1496 * of_property_read_string_helper() - Utility helper for parsing string properties
1497 * @np:		device node from which the property value is to be read.
1498 * @propname:	name of the property to be searched.
1499 * @out_strs:	output array of string pointers.
1500 * @sz:		number of array elements to read.
1501 * @skip:	Number of strings to skip over at beginning of list.
1502 *
1503 * Don't call this function directly. It is a utility helper for the
1504 * of_property_read_string*() family of functions.
1505 */
1506int of_property_read_string_helper(const struct device_node *np,
1507				   const char *propname, const char **out_strs,
1508				   size_t sz, int skip)
1509{
1510	const struct property *prop = of_find_property(np, propname, NULL);
1511	int l = 0, i = 0;
1512	const char *p, *end;
1513
1514	if (!prop)
1515		return -EINVAL;
1516	if (!prop->value)
1517		return -ENODATA;
1518	p = prop->value;
1519	end = p + prop->length;
1520
1521	for (i = 0; p < end && (!out_strs || i < skip + sz); i++, p += l) {
1522		l = strnlen(p, end - p) + 1;
1523		if (p + l > end)
1524			return -EILSEQ;
1525		if (out_strs && i >= skip)
1526			*out_strs++ = p;
1527	}
1528	i -= skip;
1529	return i <= 0 ? -ENODATA : i;
1530}
1531EXPORT_SYMBOL_GPL(of_property_read_string_helper);
1532
1533void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
1534{
1535	int i;
1536	printk("%s %s", msg, of_node_full_name(args->np));
1537	for (i = 0; i < args->args_count; i++) {
1538		const char delim = i ? ',' : ':';
1539
1540		pr_cont("%c%08x", delim, args->args[i]);
1541	}
1542	pr_cont("\n");
1543}
1544
1545int of_phandle_iterator_init(struct of_phandle_iterator *it,
1546		const struct device_node *np,
1547		const char *list_name,
1548		const char *cells_name,
1549		int cell_count)
1550{
1551	const __be32 *list;
1552	int size;
1553
1554	memset(it, 0, sizeof(*it));
1555
 
 
 
 
 
 
 
1556	list = of_get_property(np, list_name, &size);
1557	if (!list)
1558		return -ENOENT;
1559
1560	it->cells_name = cells_name;
1561	it->cell_count = cell_count;
1562	it->parent = np;
1563	it->list_end = list + size / sizeof(*list);
1564	it->phandle_end = list;
1565	it->cur = list;
1566
1567	return 0;
1568}
 
1569
1570int of_phandle_iterator_next(struct of_phandle_iterator *it)
1571{
1572	uint32_t count = 0;
1573
1574	if (it->node) {
1575		of_node_put(it->node);
1576		it->node = NULL;
1577	}
1578
1579	if (!it->cur || it->phandle_end >= it->list_end)
1580		return -ENOENT;
1581
1582	it->cur = it->phandle_end;
1583
1584	/* If phandle is 0, then it is an empty entry with no arguments. */
1585	it->phandle = be32_to_cpup(it->cur++);
1586
1587	if (it->phandle) {
1588
1589		/*
1590		 * Find the provider node and parse the #*-cells property to
1591		 * determine the argument length.
1592		 */
1593		it->node = of_find_node_by_phandle(it->phandle);
1594
1595		if (it->cells_name) {
1596			if (!it->node) {
1597				pr_err("%s: could not find phandle\n",
1598				       it->parent->full_name);
1599				goto err;
1600			}
1601
1602			if (of_property_read_u32(it->node, it->cells_name,
1603						 &count)) {
1604				pr_err("%s: could not get %s for %s\n",
1605				       it->parent->full_name,
1606				       it->cells_name,
1607				       it->node->full_name);
1608				goto err;
 
 
 
 
 
 
 
 
 
1609			}
1610		} else {
1611			count = it->cell_count;
1612		}
1613
1614		/*
1615		 * Make sure that the arguments actually fit in the remaining
1616		 * property data length
1617		 */
1618		if (it->cur + count > it->list_end) {
1619			pr_err("%s: arguments longer than property\n",
1620			       it->parent->full_name);
 
 
 
 
 
 
1621			goto err;
1622		}
1623	}
1624
1625	it->phandle_end = it->cur + count;
1626	it->cur_count = count;
1627
1628	return 0;
1629
1630err:
1631	if (it->node) {
1632		of_node_put(it->node);
1633		it->node = NULL;
1634	}
1635
1636	return -EINVAL;
1637}
 
1638
1639int of_phandle_iterator_args(struct of_phandle_iterator *it,
1640			     uint32_t *args,
1641			     int size)
1642{
1643	int i, count;
1644
1645	count = it->cur_count;
1646
1647	if (WARN_ON(size < count))
1648		count = size;
1649
1650	for (i = 0; i < count; i++)
1651		args[i] = be32_to_cpup(it->cur++);
1652
1653	return count;
1654}
1655
1656static int __of_parse_phandle_with_args(const struct device_node *np,
1657					const char *list_name,
1658					const char *cells_name,
1659					int cell_count, int index,
1660					struct of_phandle_args *out_args)
1661{
1662	struct of_phandle_iterator it;
1663	int rc, cur_index = 0;
1664
 
 
 
1665	/* Loop over the phandles until all the requested entry is found */
1666	of_for_each_phandle(&it, rc, np, list_name, cells_name, cell_count) {
1667		/*
1668		 * All of the error cases bail out of the loop, so at
1669		 * this point, the parsing is successful. If the requested
1670		 * index matches, then fill the out_args structure and return,
1671		 * or return -ENOENT for an empty entry.
1672		 */
1673		rc = -ENOENT;
1674		if (cur_index == index) {
1675			if (!it.phandle)
1676				goto err;
1677
1678			if (out_args) {
1679				int c;
1680
1681				c = of_phandle_iterator_args(&it,
1682							     out_args->args,
1683							     MAX_PHANDLE_ARGS);
1684				out_args->np = it.node;
1685				out_args->args_count = c;
1686			} else {
1687				of_node_put(it.node);
1688			}
1689
1690			/* Found it! return success */
1691			return 0;
1692		}
1693
1694		cur_index++;
1695	}
1696
1697	/*
1698	 * Unlock node before returning result; will be one of:
1699	 * -ENOENT : index is for empty phandle
1700	 * -EINVAL : parsing error on data
1701	 */
1702
1703 err:
1704	of_node_put(it.node);
1705	return rc;
1706}
 
1707
1708/**
1709 * of_parse_phandle - Resolve a phandle property to a device_node pointer
1710 * @np: Pointer to device node holding phandle property
1711 * @phandle_name: Name of property holding a phandle value
1712 * @index: For properties holding a table of phandles, this is the index into
1713 *         the table
1714 *
1715 * Returns the device_node pointer with refcount incremented.  Use
1716 * of_node_put() on it when done.
1717 */
1718struct device_node *of_parse_phandle(const struct device_node *np,
1719				     const char *phandle_name, int index)
1720{
1721	struct of_phandle_args args;
1722
1723	if (index < 0)
1724		return NULL;
1725
1726	if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0,
1727					 index, &args))
1728		return NULL;
1729
1730	return args.np;
1731}
1732EXPORT_SYMBOL(of_parse_phandle);
1733
1734/**
1735 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
1736 * @np:		pointer to a device tree node containing a list
1737 * @list_name:	property name that contains a list
1738 * @cells_name:	property name that specifies phandles' arguments count
1739 * @index:	index of a phandle to parse out
1740 * @out_args:	optional pointer to output arguments structure (will be filled)
1741 *
1742 * This function is useful to parse lists of phandles and their arguments.
1743 * Returns 0 on success and fills out_args, on error returns appropriate
1744 * errno value.
 
 
1745 *
1746 * Caller is responsible to call of_node_put() on the returned out_args->np
1747 * pointer.
1748 *
1749 * Example:
1750 *
1751 * phandle1: node1 {
1752 *	#list-cells = <2>;
1753 * }
1754 *
1755 * phandle2: node2 {
1756 *	#list-cells = <1>;
1757 * }
1758 *
1759 * node3 {
1760 *	list = <&phandle1 1 2 &phandle2 3>;
1761 * }
1762 *
1763 * To get a device_node of the `node2' node you may call this:
1764 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
1765 */
1766int of_parse_phandle_with_args(const struct device_node *np, const char *list_name,
1767				const char *cells_name, int index,
1768				struct of_phandle_args *out_args)
1769{
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1770	if (index < 0)
1771		return -EINVAL;
1772	return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
1773					    index, out_args);
1774}
1775EXPORT_SYMBOL(of_parse_phandle_with_args);
1776
1777/**
1778 * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
1779 * @np:		pointer to a device tree node containing a list
1780 * @list_name:	property name that contains a list
1781 * @cell_count: number of argument cells following the phandle
1782 * @index:	index of a phandle to parse out
1783 * @out_args:	optional pointer to output arguments structure (will be filled)
1784 *
1785 * This function is useful to parse lists of phandles and their arguments.
1786 * Returns 0 on success and fills out_args, on error returns appropriate
1787 * errno value.
1788 *
1789 * Caller is responsible to call of_node_put() on the returned out_args->np
1790 * pointer.
1791 *
1792 * Example:
1793 *
1794 * phandle1: node1 {
1795 * }
1796 *
1797 * phandle2: node2 {
1798 * }
1799 *
1800 * node3 {
1801 *	list = <&phandle1 0 2 &phandle2 2 3>;
1802 * }
1803 *
1804 * To get a device_node of the `node2' node you may call this:
1805 * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
1806 */
1807int of_parse_phandle_with_fixed_args(const struct device_node *np,
1808				const char *list_name, int cell_count,
1809				int index, struct of_phandle_args *out_args)
1810{
1811	if (index < 0)
1812		return -EINVAL;
1813	return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
1814					   index, out_args);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1815}
1816EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);
1817
1818/**
1819 * of_count_phandle_with_args() - Find the number of phandles references in a property
1820 * @np:		pointer to a device tree node containing a list
1821 * @list_name:	property name that contains a list
1822 * @cells_name:	property name that specifies phandles' arguments count
1823 *
1824 * Returns the number of phandle + argument tuples within a property. It
1825 * is a typical pattern to encode a list of phandle and variable
1826 * arguments into a single property. The number of arguments is encoded
1827 * by a property in the phandle-target node. For example, a gpios
1828 * property would contain a list of GPIO specifies consisting of a
1829 * phandle and 1 or more arguments. The number of arguments are
1830 * determined by the #gpio-cells property in the node pointed to by the
1831 * phandle.
1832 */
1833int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1834				const char *cells_name)
1835{
1836	struct of_phandle_iterator it;
1837	int rc, cur_index = 0;
1838
1839	rc = of_phandle_iterator_init(&it, np, list_name, cells_name, 0);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1840	if (rc)
1841		return rc;
1842
1843	while ((rc = of_phandle_iterator_next(&it)) == 0)
1844		cur_index += 1;
1845
1846	if (rc != -ENOENT)
1847		return rc;
1848
1849	return cur_index;
1850}
1851EXPORT_SYMBOL(of_count_phandle_with_args);
1852
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1853/**
1854 * __of_add_property - Add a property to a node without lock operations
 
 
1855 */
1856int __of_add_property(struct device_node *np, struct property *prop)
1857{
 
 
1858	struct property **next;
1859
 
 
 
 
1860	prop->next = NULL;
1861	next = &np->properties;
1862	while (*next) {
1863		if (strcmp(prop->name, (*next)->name) == 0)
1864			/* duplicate ! don't insert it */
1865			return -EEXIST;
1866
 
1867		next = &(*next)->next;
1868	}
1869	*next = prop;
1870
 
 
 
 
 
 
1871	return 0;
1872}
1873
1874/**
1875 * of_add_property - Add a property to a node
 
 
1876 */
1877int of_add_property(struct device_node *np, struct property *prop)
1878{
1879	unsigned long flags;
1880	int rc;
1881
1882	mutex_lock(&of_mutex);
1883
1884	raw_spin_lock_irqsave(&devtree_lock, flags);
1885	rc = __of_add_property(np, prop);
1886	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1887
1888	if (!rc)
1889		__of_add_property_sysfs(np, prop);
1890
1891	mutex_unlock(&of_mutex);
1892
1893	if (!rc)
1894		of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
1895
1896	return rc;
1897}
 
1898
1899int __of_remove_property(struct device_node *np, struct property *prop)
1900{
1901	struct property **next;
 
 
 
1902
1903	for (next = &np->properties; *next; next = &(*next)->next) {
1904		if (*next == prop)
1905			break;
 
 
1906	}
1907	if (*next == NULL)
1908		return -ENODEV;
1909
1910	/* found the node */
1911	*next = prop->next;
1912	prop->next = np->deadprops;
1913	np->deadprops = prop;
1914
 
1915	return 0;
1916}
1917
1918void __of_sysfs_remove_bin_file(struct device_node *np, struct property *prop)
1919{
1920	sysfs_remove_bin_file(&np->kobj, &prop->attr);
1921	kfree(prop->attr.attr.name);
1922}
1923
1924void __of_remove_property_sysfs(struct device_node *np, struct property *prop)
1925{
1926	if (!IS_ENABLED(CONFIG_SYSFS))
1927		return;
1928
1929	/* at early boot, bail here and defer setup to of_init() */
1930	if (of_kset && of_node_is_attached(np))
1931		__of_sysfs_remove_bin_file(np, prop);
1932}
1933
1934/**
1935 * of_remove_property - Remove a property from a node.
 
 
1936 *
1937 * Note that we don't actually remove it, since we have given out
1938 * who-knows-how-many pointers to the data using get-property.
1939 * Instead we just move the property to the "dead properties"
1940 * list, so it won't be found any more.
1941 */
1942int of_remove_property(struct device_node *np, struct property *prop)
1943{
1944	unsigned long flags;
1945	int rc;
1946
1947	if (!prop)
1948		return -ENODEV;
1949
1950	mutex_lock(&of_mutex);
1951
1952	raw_spin_lock_irqsave(&devtree_lock, flags);
1953	rc = __of_remove_property(np, prop);
1954	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1955
1956	if (!rc)
1957		__of_remove_property_sysfs(np, prop);
1958
1959	mutex_unlock(&of_mutex);
1960
1961	if (!rc)
1962		of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
1963
1964	return rc;
1965}
 
1966
1967int __of_update_property(struct device_node *np, struct property *newprop,
1968		struct property **oldpropp)
1969{
1970	struct property **next, *oldprop;
 
 
 
 
 
1971
1972	for (next = &np->properties; *next; next = &(*next)->next) {
1973		if (of_prop_cmp((*next)->name, newprop->name) == 0)
1974			break;
1975	}
1976	*oldpropp = oldprop = *next;
1977
1978	if (oldprop) {
1979		/* replace the node */
1980		newprop->next = oldprop->next;
1981		*next = newprop;
1982		oldprop->next = np->deadprops;
1983		np->deadprops = oldprop;
1984	} else {
1985		/* new node */
1986		newprop->next = NULL;
1987		*next = newprop;
1988	}
1989
1990	return 0;
1991}
1992
1993void __of_update_property_sysfs(struct device_node *np, struct property *newprop,
1994		struct property *oldprop)
1995{
1996	if (!IS_ENABLED(CONFIG_SYSFS))
1997		return;
1998
1999	/* At early boot, bail out and defer setup to of_init() */
2000	if (!of_kset)
2001		return;
2002
2003	if (oldprop)
2004		__of_sysfs_remove_bin_file(np, oldprop);
2005	__of_add_property_sysfs(np, newprop);
2006}
2007
2008/*
2009 * of_update_property - Update a property in a node, if the property does
2010 * not exist, add it.
2011 *
2012 * Note that we don't actually remove it, since we have given out
2013 * who-knows-how-many pointers to the data using get-property.
2014 * Instead we just move the property to the "dead properties" list,
2015 * and add the new property to the property list
2016 */
2017int of_update_property(struct device_node *np, struct property *newprop)
2018{
2019	struct property *oldprop;
2020	unsigned long flags;
2021	int rc;
2022
2023	if (!newprop->name)
2024		return -EINVAL;
2025
2026	mutex_lock(&of_mutex);
2027
2028	raw_spin_lock_irqsave(&devtree_lock, flags);
2029	rc = __of_update_property(np, newprop, &oldprop);
2030	raw_spin_unlock_irqrestore(&devtree_lock, flags);
2031
2032	if (!rc)
2033		__of_update_property_sysfs(np, newprop, oldprop);
2034
2035	mutex_unlock(&of_mutex);
2036
2037	if (!rc)
2038		of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
2039
2040	return rc;
2041}
2042
2043static void of_alias_add(struct alias_prop *ap, struct device_node *np,
2044			 int id, const char *stem, int stem_len)
2045{
2046	ap->np = np;
2047	ap->id = id;
2048	strncpy(ap->stem, stem, stem_len);
2049	ap->stem[stem_len] = 0;
2050	list_add_tail(&ap->link, &aliases_lookup);
2051	pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
2052		 ap->alias, ap->stem, ap->id, of_node_full_name(np));
2053}
2054
2055/**
2056 * of_alias_scan - Scan all properties of the 'aliases' node
 
 
2057 *
2058 * The function scans all the properties of the 'aliases' node and populates
2059 * the global lookup table with the properties.  It returns the
2060 * number of alias properties found, or an error code in case of failure.
2061 *
2062 * @dt_alloc:	An allocator that provides a virtual address to memory
2063 *		for storing the resulting tree
2064 */
2065void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
2066{
2067	struct property *pp;
2068
2069	of_aliases = of_find_node_by_path("/aliases");
2070	of_chosen = of_find_node_by_path("/chosen");
2071	if (of_chosen == NULL)
2072		of_chosen = of_find_node_by_path("/chosen@0");
2073
2074	if (of_chosen) {
2075		/* linux,stdout-path and /aliases/stdout are for legacy compatibility */
2076		const char *name = of_get_property(of_chosen, "stdout-path", NULL);
2077		if (!name)
2078			name = of_get_property(of_chosen, "linux,stdout-path", NULL);
 
 
2079		if (IS_ENABLED(CONFIG_PPC) && !name)
2080			name = of_get_property(of_aliases, "stdout", NULL);
2081		if (name)
2082			of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
 
 
2083	}
2084
2085	if (!of_aliases)
2086		return;
2087
2088	for_each_property_of_node(of_aliases, pp) {
2089		const char *start = pp->name;
2090		const char *end = start + strlen(start);
2091		struct device_node *np;
2092		struct alias_prop *ap;
2093		int id, len;
2094
2095		/* Skip those we do not want to proceed */
2096		if (!strcmp(pp->name, "name") ||
2097		    !strcmp(pp->name, "phandle") ||
2098		    !strcmp(pp->name, "linux,phandle"))
2099			continue;
2100
2101		np = of_find_node_by_path(pp->value);
2102		if (!np)
2103			continue;
2104
2105		/* walk the alias backwards to extract the id and work out
2106		 * the 'stem' string */
2107		while (isdigit(*(end-1)) && end > start)
2108			end--;
2109		len = end - start;
2110
2111		if (kstrtoint(end, 10, &id) < 0)
2112			continue;
2113
2114		/* Allocate an alias_prop with enough space for the stem */
2115		ap = dt_alloc(sizeof(*ap) + len + 1, 4);
2116		if (!ap)
2117			continue;
2118		memset(ap, 0, sizeof(*ap) + len + 1);
2119		ap->alias = start;
2120		of_alias_add(ap, np, id, start, len);
2121	}
2122}
2123
2124/**
2125 * of_alias_get_id - Get alias id for the given device_node
2126 * @np:		Pointer to the given device_node
2127 * @stem:	Alias stem of the given device_node
2128 *
2129 * The function travels the lookup table to get the alias id for the given
2130 * device_node and alias stem.  It returns the alias id if found.
 
 
2131 */
2132int of_alias_get_id(struct device_node *np, const char *stem)
2133{
2134	struct alias_prop *app;
2135	int id = -ENODEV;
2136
2137	mutex_lock(&of_mutex);
2138	list_for_each_entry(app, &aliases_lookup, link) {
2139		if (strcmp(app->stem, stem) != 0)
2140			continue;
2141
2142		if (np == app->np) {
2143			id = app->id;
2144			break;
2145		}
2146	}
2147	mutex_unlock(&of_mutex);
2148
2149	return id;
2150}
2151EXPORT_SYMBOL_GPL(of_alias_get_id);
2152
2153/**
2154 * of_alias_get_highest_id - Get highest alias id for the given stem
2155 * @stem:	Alias stem to be examined
2156 *
2157 * The function travels the lookup table to get the highest alias id for the
2158 * given alias stem.  It returns the alias id if found.
2159 */
2160int of_alias_get_highest_id(const char *stem)
2161{
2162	struct alias_prop *app;
2163	int id = -ENODEV;
2164
2165	mutex_lock(&of_mutex);
2166	list_for_each_entry(app, &aliases_lookup, link) {
2167		if (strcmp(app->stem, stem) != 0)
2168			continue;
2169
2170		if (app->id > id)
2171			id = app->id;
2172	}
2173	mutex_unlock(&of_mutex);
2174
2175	return id;
2176}
2177EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
2178
2179const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
2180			       u32 *pu)
2181{
2182	const void *curv = cur;
2183
2184	if (!prop)
2185		return NULL;
2186
2187	if (!cur) {
2188		curv = prop->value;
2189		goto out_val;
2190	}
2191
2192	curv += sizeof(*cur);
2193	if (curv >= prop->value + prop->length)
2194		return NULL;
2195
2196out_val:
2197	*pu = be32_to_cpup(curv);
2198	return curv;
2199}
2200EXPORT_SYMBOL_GPL(of_prop_next_u32);
2201
2202const char *of_prop_next_string(struct property *prop, const char *cur)
2203{
2204	const void *curv = cur;
2205
2206	if (!prop)
2207		return NULL;
2208
2209	if (!cur)
2210		return prop->value;
2211
2212	curv += strlen(cur) + 1;
2213	if (curv >= prop->value + prop->length)
2214		return NULL;
2215
2216	return curv;
2217}
2218EXPORT_SYMBOL_GPL(of_prop_next_string);
2219
2220/**
2221 * of_console_check() - Test and setup console for DT setup
2222 * @dn - Pointer to device node
2223 * @name - Name to use for preferred console without index. ex. "ttyS"
2224 * @index - Index to use for preferred console.
2225 *
2226 * Check if the given device node matches the stdout-path property in the
2227 * /chosen node. If it does then register it as the preferred console and return
2228 * TRUE. Otherwise return FALSE.
 
2229 */
2230bool of_console_check(struct device_node *dn, char *name, int index)
2231{
2232	if (!dn || dn != of_stdout || console_set_on_cmdline)
2233		return false;
2234	return !add_preferred_console(name, index,
2235				      kstrdup(of_stdout_options, GFP_KERNEL));
 
 
 
 
2236}
2237EXPORT_SYMBOL_GPL(of_console_check);
2238
2239/**
2240 *	of_find_next_cache_node - Find a node's subsidiary cache
2241 *	@np:	node of type "cpu" or "cache"
2242 *
2243 *	Returns a node pointer with refcount incremented, use
2244 *	of_node_put() on it when done.  Caller should hold a reference
2245 *	to np.
2246 */
2247struct device_node *of_find_next_cache_node(const struct device_node *np)
2248{
2249	struct device_node *child;
2250	const phandle *handle;
2251
2252	handle = of_get_property(np, "l2-cache", NULL);
2253	if (!handle)
2254		handle = of_get_property(np, "next-level-cache", NULL);
2255
2256	if (handle)
2257		return of_find_node_by_phandle(be32_to_cpup(handle));
2258
2259	/* OF on pmac has nodes instead of properties named "l2-cache"
2260	 * beneath CPU nodes.
2261	 */
2262	if (!strcmp(np->type, "cpu"))
2263		for_each_child_of_node(np, child)
2264			if (!strcmp(child->type, "cache"))
2265				return child;
2266
2267	return NULL;
2268}
2269
2270/**
2271 * of_graph_parse_endpoint() - parse common endpoint node properties
2272 * @node: pointer to endpoint device_node
2273 * @endpoint: pointer to the OF endpoint data structure
 
2274 *
2275 * The caller should hold a reference to @node.
 
2276 */
2277int of_graph_parse_endpoint(const struct device_node *node,
2278			    struct of_endpoint *endpoint)
2279{
2280	struct device_node *port_node = of_get_parent(node);
 
2281
2282	WARN_ONCE(!port_node, "%s(): endpoint %s has no parent node\n",
2283		  __func__, node->full_name);
 
 
 
2284
2285	memset(endpoint, 0, sizeof(*endpoint));
 
2286
2287	endpoint->local_node = node;
2288	/*
2289	 * It doesn't matter whether the two calls below succeed.
2290	 * If they don't then the default value 0 is used.
2291	 */
2292	of_property_read_u32(port_node, "reg", &endpoint->port);
2293	of_property_read_u32(node, "reg", &endpoint->id);
2294
2295	of_node_put(port_node);
2296
2297	return 0;
2298}
2299EXPORT_SYMBOL(of_graph_parse_endpoint);
2300
2301/**
2302 * of_graph_get_port_by_id() - get the port matching a given id
2303 * @parent: pointer to the parent device node
2304 * @id: id of the port
 
 
 
 
2305 *
2306 * Return: A 'port' node pointer with refcount incremented. The caller
2307 * has to use of_node_put() on it when done.
 
 
 
 
 
 
 
2308 */
2309struct device_node *of_graph_get_port_by_id(struct device_node *parent, u32 id)
 
 
2310{
2311	struct device_node *node, *port;
 
 
2312
2313	node = of_get_child_by_name(parent, "ports");
2314	if (node)
2315		parent = node;
2316
2317	for_each_child_of_node(parent, port) {
2318		u32 port_id = 0;
 
 
 
 
 
 
2319
2320		if (of_node_cmp(port->name, "port") != 0)
2321			continue;
2322		of_property_read_u32(port, "reg", &port_id);
2323		if (id == port_id)
2324			break;
2325	}
2326
2327	of_node_put(node);
2328
2329	return port;
2330}
2331EXPORT_SYMBOL(of_graph_get_port_by_id);
2332
2333/**
2334 * of_graph_get_next_endpoint() - get next endpoint node
2335 * @parent: pointer to the parent device node
2336 * @prev: previous endpoint node, or NULL to get first
2337 *
2338 * Return: An 'endpoint' node pointer with refcount incremented. Refcount
2339 * of the passed @prev node is decremented.
2340 */
2341struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
2342					struct device_node *prev)
2343{
2344	struct device_node *endpoint;
2345	struct device_node *port;
2346
2347	if (!parent)
2348		return NULL;
2349
2350	/*
2351	 * Start by locating the port node. If no previous endpoint is specified
2352	 * search for the first port node, otherwise get the previous endpoint
2353	 * parent port node.
2354	 */
2355	if (!prev) {
2356		struct device_node *node;
2357
2358		node = of_get_child_by_name(parent, "ports");
2359		if (node)
2360			parent = node;
 
 
 
 
 
 
 
 
 
 
 
2361
2362		port = of_get_child_by_name(parent, "port");
2363		of_node_put(node);
2364
2365		if (!port) {
2366			pr_err("graph: no port node found in %s\n",
2367			       parent->full_name);
2368			return NULL;
2369		}
2370	} else {
2371		port = of_get_parent(prev);
2372		if (WARN_ONCE(!port, "%s(): endpoint %s has no parent node\n",
2373			      __func__, prev->full_name))
2374			return NULL;
2375	}
2376
2377	while (1) {
2378		/*
2379		 * Now that we have a port node, get the next endpoint by
2380		 * getting the next child. If the previous endpoint is NULL this
2381		 * will return the first child.
2382		 */
2383		endpoint = of_get_next_child(port, prev);
2384		if (endpoint) {
2385			of_node_put(port);
2386			return endpoint;
2387		}
2388
2389		/* No more endpoints under this port, try the next one. */
2390		prev = NULL;
2391
2392		do {
2393			port = of_get_next_child(parent, port);
2394			if (!port)
2395				return NULL;
2396		} while (of_node_cmp(port->name, "port"));
2397	}
2398}
2399EXPORT_SYMBOL(of_graph_get_next_endpoint);
2400
2401/**
2402 * of_graph_get_endpoint_by_regs() - get endpoint node of specific identifiers
2403 * @parent: pointer to the parent device node
2404 * @port_reg: identifier (value of reg property) of the parent port node
2405 * @reg: identifier (value of reg property) of the endpoint node
2406 *
2407 * Return: An 'endpoint' node pointer which is identified by reg and at the same
2408 * is the child of a port node identified by port_reg. reg and port_reg are
2409 * ignored when they are -1.
2410 */
2411struct device_node *of_graph_get_endpoint_by_regs(
2412	const struct device_node *parent, int port_reg, int reg)
2413{
2414	struct of_endpoint endpoint;
2415	struct device_node *node = NULL;
2416
2417	for_each_endpoint_of_node(parent, node) {
2418		of_graph_parse_endpoint(node, &endpoint);
2419		if (((port_reg == -1) || (endpoint.port == port_reg)) &&
2420			((reg == -1) || (endpoint.id == reg)))
2421			return node;
2422	}
2423
2424	return NULL;
2425}
2426EXPORT_SYMBOL(of_graph_get_endpoint_by_regs);
2427
2428/**
2429 * of_graph_get_remote_port_parent() - get remote port's parent node
2430 * @node: pointer to a local endpoint device_node
2431 *
2432 * Return: Remote device node associated with remote endpoint node linked
2433 *	   to @node. Use of_node_put() on it when done.
2434 */
2435struct device_node *of_graph_get_remote_port_parent(
2436			       const struct device_node *node)
2437{
2438	struct device_node *np;
2439	unsigned int depth;
2440
2441	/* Get remote endpoint node. */
2442	np = of_parse_phandle(node, "remote-endpoint", 0);
2443
2444	/* Walk 3 levels up only if there is 'ports' node. */
2445	for (depth = 3; depth && np; depth--) {
2446		np = of_get_next_parent(np);
2447		if (depth == 2 && of_node_cmp(np->name, "ports"))
2448			break;
2449	}
2450	return np;
2451}
2452EXPORT_SYMBOL(of_graph_get_remote_port_parent);
2453
2454/**
2455 * of_graph_get_remote_port() - get remote port node
2456 * @node: pointer to a local endpoint device_node
2457 *
2458 * Return: Remote port node associated with remote endpoint node linked
2459 *	   to @node. Use of_node_put() on it when done.
2460 */
2461struct device_node *of_graph_get_remote_port(const struct device_node *node)
2462{
2463	struct device_node *np;
2464
2465	/* Get remote endpoint node. */
2466	np = of_parse_phandle(node, "remote-endpoint", 0);
2467	if (!np)
2468		return NULL;
2469	return of_get_next_parent(np);
2470}
2471EXPORT_SYMBOL(of_graph_get_remote_port);