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/console.h> 20 #include <linux/ctype.h> 21 #include <linux/cpu.h> 22 #include <linux/module.h> 23 #include <linux/of.h> 24 #include <linux/of_device.h> 25 #include <linux/of_graph.h> 26 #include <linux/spinlock.h> 27 #include <linux/slab.h> 28 #include <linux/string.h> 29 #include <linux/proc_fs.h> 30 31 #include "of_private.h" 32 33 LIST_HEAD(aliases_lookup); 34 35 struct device_node *of_root; 36 EXPORT_SYMBOL(of_root); 37 struct device_node *of_chosen; 38 EXPORT_SYMBOL(of_chosen); 39 struct device_node *of_aliases; 40 struct device_node *of_stdout; 41 static const char *of_stdout_options; 42 43 struct kset *of_kset; 44 45 /* 46 * Used to protect the of_aliases, to hold off addition of nodes to sysfs. 47 * This mutex must be held whenever modifications are being made to the 48 * device tree. The of_{attach,detach}_node() and 49 * of_{add,remove,update}_property() helpers make sure this happens. 50 */ 51 DEFINE_MUTEX(of_mutex); 52 53 /* use when traversing tree through the child, sibling, 54 * or parent members of struct device_node. 55 */ 56 DEFINE_RAW_SPINLOCK(devtree_lock); 57 58 bool of_node_name_eq(const struct device_node *np, const char *name) 59 { 60 const char *node_name; 61 size_t len; 62 63 if (!np) 64 return false; 65 66 node_name = kbasename(np->full_name); 67 len = strchrnul(node_name, '@') - node_name; 68 69 return (strlen(name) == len) && (strncmp(node_name, name, len) == 0); 70 } 71 EXPORT_SYMBOL(of_node_name_eq); 72 73 bool of_node_name_prefix(const struct device_node *np, const char *prefix) 74 { 75 if (!np) 76 return false; 77 78 return strncmp(kbasename(np->full_name), prefix, strlen(prefix)) == 0; 79 } 80 EXPORT_SYMBOL(of_node_name_prefix); 81 82 static bool __of_node_is_type(const struct device_node *np, const char *type) 83 { 84 const char *match = __of_get_property(np, "device_type", NULL); 85 86 return np && match && type && !strcmp(match, type); 87 } 88 89 int of_bus_n_addr_cells(struct device_node *np) 90 { 91 u32 cells; 92 93 for (; np; np = np->parent) 94 if (!of_property_read_u32(np, "#address-cells", &cells)) 95 return cells; 96 97 /* No #address-cells property for the root node */ 98 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT; 99 } 100 101 int of_n_addr_cells(struct device_node *np) 102 { 103 if (np->parent) 104 np = np->parent; 105 106 return of_bus_n_addr_cells(np); 107 } 108 EXPORT_SYMBOL(of_n_addr_cells); 109 110 int of_bus_n_size_cells(struct device_node *np) 111 { 112 u32 cells; 113 114 for (; np; np = np->parent) 115 if (!of_property_read_u32(np, "#size-cells", &cells)) 116 return cells; 117 118 /* No #size-cells property for the root node */ 119 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT; 120 } 121 122 int of_n_size_cells(struct device_node *np) 123 { 124 if (np->parent) 125 np = np->parent; 126 127 return of_bus_n_size_cells(np); 128 } 129 EXPORT_SYMBOL(of_n_size_cells); 130 131 #ifdef CONFIG_NUMA 132 int __weak of_node_to_nid(struct device_node *np) 133 { 134 return NUMA_NO_NODE; 135 } 136 #endif 137 138 #define OF_PHANDLE_CACHE_BITS 7 139 #define OF_PHANDLE_CACHE_SZ BIT(OF_PHANDLE_CACHE_BITS) 140 141 static struct device_node *phandle_cache[OF_PHANDLE_CACHE_SZ]; 142 143 static u32 of_phandle_cache_hash(phandle handle) 144 { 145 return hash_32(handle, OF_PHANDLE_CACHE_BITS); 146 } 147 148 /* 149 * Caller must hold devtree_lock. 150 */ 151 void __of_phandle_cache_inv_entry(phandle handle) 152 { 153 u32 handle_hash; 154 struct device_node *np; 155 156 if (!handle) 157 return; 158 159 handle_hash = of_phandle_cache_hash(handle); 160 161 np = phandle_cache[handle_hash]; 162 if (np && handle == np->phandle) 163 phandle_cache[handle_hash] = NULL; 164 } 165 166 void __init of_core_init(void) 167 { 168 struct device_node *np; 169 170 171 /* Create the kset, and register existing nodes */ 172 mutex_lock(&of_mutex); 173 of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj); 174 if (!of_kset) { 175 mutex_unlock(&of_mutex); 176 pr_err("failed to register existing nodes\n"); 177 return; 178 } 179 for_each_of_allnodes(np) { 180 __of_attach_node_sysfs(np); 181 if (np->phandle && !phandle_cache[of_phandle_cache_hash(np->phandle)]) 182 phandle_cache[of_phandle_cache_hash(np->phandle)] = np; 183 } 184 mutex_unlock(&of_mutex); 185 186 /* Symlink in /proc as required by userspace ABI */ 187 if (of_root) 188 proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base"); 189 } 190 191 static struct property *__of_find_property(const struct device_node *np, 192 const char *name, int *lenp) 193 { 194 struct property *pp; 195 196 if (!np) 197 return NULL; 198 199 for (pp = np->properties; pp; pp = pp->next) { 200 if (of_prop_cmp(pp->name, name) == 0) { 201 if (lenp) 202 *lenp = pp->length; 203 break; 204 } 205 } 206 207 return pp; 208 } 209 210 struct property *of_find_property(const struct device_node *np, 211 const char *name, 212 int *lenp) 213 { 214 struct property *pp; 215 unsigned long flags; 216 217 raw_spin_lock_irqsave(&devtree_lock, flags); 218 pp = __of_find_property(np, name, lenp); 219 raw_spin_unlock_irqrestore(&devtree_lock, flags); 220 221 return pp; 222 } 223 EXPORT_SYMBOL(of_find_property); 224 225 struct device_node *__of_find_all_nodes(struct device_node *prev) 226 { 227 struct device_node *np; 228 if (!prev) { 229 np = of_root; 230 } else if (prev->child) { 231 np = prev->child; 232 } else { 233 /* Walk back up looking for a sibling, or the end of the structure */ 234 np = prev; 235 while (np->parent && !np->sibling) 236 np = np->parent; 237 np = np->sibling; /* Might be null at the end of the tree */ 238 } 239 return np; 240 } 241 242 /** 243 * of_find_all_nodes - Get next node in global list 244 * @prev: Previous node or NULL to start iteration 245 * of_node_put() will be called on it 246 * 247 * Return: A node pointer with refcount incremented, use 248 * of_node_put() on it when done. 249 */ 250 struct device_node *of_find_all_nodes(struct device_node *prev) 251 { 252 struct device_node *np; 253 unsigned long flags; 254 255 raw_spin_lock_irqsave(&devtree_lock, flags); 256 np = __of_find_all_nodes(prev); 257 of_node_get(np); 258 of_node_put(prev); 259 raw_spin_unlock_irqrestore(&devtree_lock, flags); 260 return np; 261 } 262 EXPORT_SYMBOL(of_find_all_nodes); 263 264 /* 265 * Find a property with a given name for a given node 266 * and return the value. 267 */ 268 const void *__of_get_property(const struct device_node *np, 269 const char *name, int *lenp) 270 { 271 struct property *pp = __of_find_property(np, name, lenp); 272 273 return pp ? pp->value : NULL; 274 } 275 276 /* 277 * Find a property with a given name for a given node 278 * and return the value. 279 */ 280 const void *of_get_property(const struct device_node *np, const char *name, 281 int *lenp) 282 { 283 struct property *pp = of_find_property(np, name, lenp); 284 285 return pp ? pp->value : NULL; 286 } 287 EXPORT_SYMBOL(of_get_property); 288 289 /** 290 * of_get_cpu_hwid - Get the hardware ID from a CPU device node 291 * 292 * @cpun: CPU number(logical index) for which device node is required 293 * @thread: The local thread number to get the hardware ID for. 294 * 295 * Return: The hardware ID for the CPU node or ~0ULL if not found. 296 */ 297 u64 of_get_cpu_hwid(struct device_node *cpun, unsigned int thread) 298 { 299 const __be32 *cell; 300 int ac, len; 301 302 ac = of_n_addr_cells(cpun); 303 cell = of_get_property(cpun, "reg", &len); 304 if (!cell || !ac || ((sizeof(*cell) * ac * (thread + 1)) > len)) 305 return ~0ULL; 306 307 cell += ac * thread; 308 return of_read_number(cell, ac); 309 } 310 311 /* 312 * arch_match_cpu_phys_id - Match the given logical CPU and physical id 313 * 314 * @cpu: logical cpu index of a core/thread 315 * @phys_id: physical identifier of a core/thread 316 * 317 * CPU logical to physical index mapping is architecture specific. 318 * However this __weak function provides a default match of physical 319 * id to logical cpu index. phys_id provided here is usually values read 320 * from the device tree which must match the hardware internal registers. 321 * 322 * Returns true if the physical identifier and the logical cpu index 323 * correspond to the same core/thread, false otherwise. 324 */ 325 bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id) 326 { 327 return (u32)phys_id == cpu; 328 } 329 330 /* 331 * Checks if the given "prop_name" property holds the physical id of the 332 * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not 333 * NULL, local thread number within the core is returned in it. 334 */ 335 static bool __of_find_n_match_cpu_property(struct device_node *cpun, 336 const char *prop_name, int cpu, unsigned int *thread) 337 { 338 const __be32 *cell; 339 int ac, prop_len, tid; 340 u64 hwid; 341 342 ac = of_n_addr_cells(cpun); 343 cell = of_get_property(cpun, prop_name, &prop_len); 344 if (!cell && !ac && arch_match_cpu_phys_id(cpu, 0)) 345 return true; 346 if (!cell || !ac) 347 return false; 348 prop_len /= sizeof(*cell) * ac; 349 for (tid = 0; tid < prop_len; tid++) { 350 hwid = of_read_number(cell, ac); 351 if (arch_match_cpu_phys_id(cpu, hwid)) { 352 if (thread) 353 *thread = tid; 354 return true; 355 } 356 cell += ac; 357 } 358 return false; 359 } 360 361 /* 362 * arch_find_n_match_cpu_physical_id - See if the given device node is 363 * for the cpu corresponding to logical cpu 'cpu'. Return true if so, 364 * else false. If 'thread' is non-NULL, the local thread number within the 365 * core is returned in it. 366 */ 367 bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun, 368 int cpu, unsigned int *thread) 369 { 370 /* Check for non-standard "ibm,ppc-interrupt-server#s" property 371 * for thread ids on PowerPC. If it doesn't exist fallback to 372 * standard "reg" property. 373 */ 374 if (IS_ENABLED(CONFIG_PPC) && 375 __of_find_n_match_cpu_property(cpun, 376 "ibm,ppc-interrupt-server#s", 377 cpu, thread)) 378 return true; 379 380 return __of_find_n_match_cpu_property(cpun, "reg", cpu, thread); 381 } 382 383 /** 384 * of_get_cpu_node - Get device node associated with the given logical CPU 385 * 386 * @cpu: CPU number(logical index) for which device node is required 387 * @thread: if not NULL, local thread number within the physical core is 388 * returned 389 * 390 * The main purpose of this function is to retrieve the device node for the 391 * given logical CPU index. It should be used to initialize the of_node in 392 * cpu device. Once of_node in cpu device is populated, all the further 393 * references can use that instead. 394 * 395 * CPU logical to physical index mapping is architecture specific and is built 396 * before booting secondary cores. This function uses arch_match_cpu_phys_id 397 * which can be overridden by architecture specific implementation. 398 * 399 * Return: A node pointer for the logical cpu with refcount incremented, use 400 * of_node_put() on it when done. Returns NULL if not found. 401 */ 402 struct device_node *of_get_cpu_node(int cpu, unsigned int *thread) 403 { 404 struct device_node *cpun; 405 406 for_each_of_cpu_node(cpun) { 407 if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread)) 408 return cpun; 409 } 410 return NULL; 411 } 412 EXPORT_SYMBOL(of_get_cpu_node); 413 414 /** 415 * of_cpu_node_to_id: Get the logical CPU number for a given device_node 416 * 417 * @cpu_node: Pointer to the device_node for CPU. 418 * 419 * Return: The logical CPU number of the given CPU device_node or -ENODEV if the 420 * CPU is not found. 421 */ 422 int of_cpu_node_to_id(struct device_node *cpu_node) 423 { 424 int cpu; 425 bool found = false; 426 struct device_node *np; 427 428 for_each_possible_cpu(cpu) { 429 np = of_cpu_device_node_get(cpu); 430 found = (cpu_node == np); 431 of_node_put(np); 432 if (found) 433 return cpu; 434 } 435 436 return -ENODEV; 437 } 438 EXPORT_SYMBOL(of_cpu_node_to_id); 439 440 /** 441 * of_get_cpu_state_node - Get CPU's idle state node at the given index 442 * 443 * @cpu_node: The device node for the CPU 444 * @index: The index in the list of the idle states 445 * 446 * Two generic methods can be used to describe a CPU's idle states, either via 447 * a flattened description through the "cpu-idle-states" binding or via the 448 * hierarchical layout, using the "power-domains" and the "domain-idle-states" 449 * bindings. This function check for both and returns the idle state node for 450 * the requested index. 451 * 452 * Return: An idle state node if found at @index. The refcount is incremented 453 * for it, so call of_node_put() on it when done. Returns NULL if not found. 454 */ 455 struct device_node *of_get_cpu_state_node(struct device_node *cpu_node, 456 int index) 457 { 458 struct of_phandle_args args; 459 int err; 460 461 err = of_parse_phandle_with_args(cpu_node, "power-domains", 462 "#power-domain-cells", 0, &args); 463 if (!err) { 464 struct device_node *state_node = 465 of_parse_phandle(args.np, "domain-idle-states", index); 466 467 of_node_put(args.np); 468 if (state_node) 469 return state_node; 470 } 471 472 return of_parse_phandle(cpu_node, "cpu-idle-states", index); 473 } 474 EXPORT_SYMBOL(of_get_cpu_state_node); 475 476 /** 477 * __of_device_is_compatible() - Check if the node matches given constraints 478 * @device: pointer to node 479 * @compat: required compatible string, NULL or "" for any match 480 * @type: required device_type value, NULL or "" for any match 481 * @name: required node name, NULL or "" for any match 482 * 483 * Checks if the given @compat, @type and @name strings match the 484 * properties of the given @device. A constraints can be skipped by 485 * passing NULL or an empty string as the constraint. 486 * 487 * Returns 0 for no match, and a positive integer on match. The return 488 * value is a relative score with larger values indicating better 489 * matches. The score is weighted for the most specific compatible value 490 * to get the highest score. Matching type is next, followed by matching 491 * name. Practically speaking, this results in the following priority 492 * order for matches: 493 * 494 * 1. specific compatible && type && name 495 * 2. specific compatible && type 496 * 3. specific compatible && name 497 * 4. specific compatible 498 * 5. general compatible && type && name 499 * 6. general compatible && type 500 * 7. general compatible && name 501 * 8. general compatible 502 * 9. type && name 503 * 10. type 504 * 11. name 505 */ 506 static int __of_device_is_compatible(const struct device_node *device, 507 const char *compat, const char *type, const char *name) 508 { 509 struct property *prop; 510 const char *cp; 511 int index = 0, score = 0; 512 513 /* Compatible match has highest priority */ 514 if (compat && compat[0]) { 515 prop = __of_find_property(device, "compatible", NULL); 516 for (cp = of_prop_next_string(prop, NULL); cp; 517 cp = of_prop_next_string(prop, cp), index++) { 518 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) { 519 score = INT_MAX/2 - (index << 2); 520 break; 521 } 522 } 523 if (!score) 524 return 0; 525 } 526 527 /* Matching type is better than matching name */ 528 if (type && type[0]) { 529 if (!__of_node_is_type(device, type)) 530 return 0; 531 score += 2; 532 } 533 534 /* Matching name is a bit better than not */ 535 if (name && name[0]) { 536 if (!of_node_name_eq(device, name)) 537 return 0; 538 score++; 539 } 540 541 return score; 542 } 543 544 /** Checks if the given "compat" string matches one of the strings in 545 * the device's "compatible" property 546 */ 547 int of_device_is_compatible(const struct device_node *device, 548 const char *compat) 549 { 550 unsigned long flags; 551 int res; 552 553 raw_spin_lock_irqsave(&devtree_lock, flags); 554 res = __of_device_is_compatible(device, compat, NULL, NULL); 555 raw_spin_unlock_irqrestore(&devtree_lock, flags); 556 return res; 557 } 558 EXPORT_SYMBOL(of_device_is_compatible); 559 560 /** Checks if the device is compatible with any of the entries in 561 * a NULL terminated array of strings. Returns the best match 562 * score or 0. 563 */ 564 int of_device_compatible_match(const struct device_node *device, 565 const char *const *compat) 566 { 567 unsigned int tmp, score = 0; 568 569 if (!compat) 570 return 0; 571 572 while (*compat) { 573 tmp = of_device_is_compatible(device, *compat); 574 if (tmp > score) 575 score = tmp; 576 compat++; 577 } 578 579 return score; 580 } 581 EXPORT_SYMBOL_GPL(of_device_compatible_match); 582 583 /** 584 * of_machine_is_compatible - Test root of device tree for a given compatible value 585 * @compat: compatible string to look for in root node's compatible property. 586 * 587 * Return: A positive integer if the root node has the given value in its 588 * compatible property. 589 */ 590 int of_machine_is_compatible(const char *compat) 591 { 592 struct device_node *root; 593 int rc = 0; 594 595 root = of_find_node_by_path("/"); 596 if (root) { 597 rc = of_device_is_compatible(root, compat); 598 of_node_put(root); 599 } 600 return rc; 601 } 602 EXPORT_SYMBOL(of_machine_is_compatible); 603 604 /** 605 * __of_device_is_available - check if a device is available for use 606 * 607 * @device: Node to check for availability, with locks already held 608 * 609 * Return: True if the status property is absent or set to "okay" or "ok", 610 * false otherwise 611 */ 612 static bool __of_device_is_available(const struct device_node *device) 613 { 614 const char *status; 615 int statlen; 616 617 if (!device) 618 return false; 619 620 status = __of_get_property(device, "status", &statlen); 621 if (status == NULL) 622 return true; 623 624 if (statlen > 0) { 625 if (!strcmp(status, "okay") || !strcmp(status, "ok")) 626 return true; 627 } 628 629 return false; 630 } 631 632 /** 633 * of_device_is_available - check if a device is available for use 634 * 635 * @device: Node to check for availability 636 * 637 * Return: True if the status property is absent or set to "okay" or "ok", 638 * false otherwise 639 */ 640 bool of_device_is_available(const struct device_node *device) 641 { 642 unsigned long flags; 643 bool res; 644 645 raw_spin_lock_irqsave(&devtree_lock, flags); 646 res = __of_device_is_available(device); 647 raw_spin_unlock_irqrestore(&devtree_lock, flags); 648 return res; 649 650 } 651 EXPORT_SYMBOL(of_device_is_available); 652 653 /** 654 * __of_device_is_fail - check if a device has status "fail" or "fail-..." 655 * 656 * @device: Node to check status for, with locks already held 657 * 658 * Return: True if the status property is set to "fail" or "fail-..." (for any 659 * error code suffix), false otherwise 660 */ 661 static bool __of_device_is_fail(const struct device_node *device) 662 { 663 const char *status; 664 665 if (!device) 666 return false; 667 668 status = __of_get_property(device, "status", NULL); 669 if (status == NULL) 670 return false; 671 672 return !strcmp(status, "fail") || !strncmp(status, "fail-", 5); 673 } 674 675 /** 676 * of_device_is_big_endian - check if a device has BE registers 677 * 678 * @device: Node to check for endianness 679 * 680 * Return: True if the device has a "big-endian" property, or if the kernel 681 * was compiled for BE *and* the device has a "native-endian" property. 682 * Returns false otherwise. 683 * 684 * Callers would nominally use ioread32be/iowrite32be if 685 * of_device_is_big_endian() == true, or readl/writel otherwise. 686 */ 687 bool of_device_is_big_endian(const struct device_node *device) 688 { 689 if (of_property_read_bool(device, "big-endian")) 690 return true; 691 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) && 692 of_property_read_bool(device, "native-endian")) 693 return true; 694 return false; 695 } 696 EXPORT_SYMBOL(of_device_is_big_endian); 697 698 /** 699 * of_get_parent - Get a node's parent if any 700 * @node: Node to get parent 701 * 702 * Return: A node pointer with refcount incremented, use 703 * of_node_put() on it when done. 704 */ 705 struct device_node *of_get_parent(const struct device_node *node) 706 { 707 struct device_node *np; 708 unsigned long flags; 709 710 if (!node) 711 return NULL; 712 713 raw_spin_lock_irqsave(&devtree_lock, flags); 714 np = of_node_get(node->parent); 715 raw_spin_unlock_irqrestore(&devtree_lock, flags); 716 return np; 717 } 718 EXPORT_SYMBOL(of_get_parent); 719 720 /** 721 * of_get_next_parent - Iterate to a node's parent 722 * @node: Node to get parent of 723 * 724 * This is like of_get_parent() except that it drops the 725 * refcount on the passed node, making it suitable for iterating 726 * through a node's parents. 727 * 728 * Return: A node pointer with refcount incremented, use 729 * of_node_put() on it when done. 730 */ 731 struct device_node *of_get_next_parent(struct device_node *node) 732 { 733 struct device_node *parent; 734 unsigned long flags; 735 736 if (!node) 737 return NULL; 738 739 raw_spin_lock_irqsave(&devtree_lock, flags); 740 parent = of_node_get(node->parent); 741 of_node_put(node); 742 raw_spin_unlock_irqrestore(&devtree_lock, flags); 743 return parent; 744 } 745 EXPORT_SYMBOL(of_get_next_parent); 746 747 static struct device_node *__of_get_next_child(const struct device_node *node, 748 struct device_node *prev) 749 { 750 struct device_node *next; 751 752 if (!node) 753 return NULL; 754 755 next = prev ? prev->sibling : node->child; 756 of_node_get(next); 757 of_node_put(prev); 758 return next; 759 } 760 #define __for_each_child_of_node(parent, child) \ 761 for (child = __of_get_next_child(parent, NULL); child != NULL; \ 762 child = __of_get_next_child(parent, child)) 763 764 /** 765 * of_get_next_child - Iterate a node childs 766 * @node: parent node 767 * @prev: previous child of the parent node, or NULL to get first 768 * 769 * Return: A node pointer with refcount incremented, use of_node_put() on 770 * it when done. Returns NULL when prev is the last child. Decrements the 771 * refcount of prev. 772 */ 773 struct device_node *of_get_next_child(const struct device_node *node, 774 struct device_node *prev) 775 { 776 struct device_node *next; 777 unsigned long flags; 778 779 raw_spin_lock_irqsave(&devtree_lock, flags); 780 next = __of_get_next_child(node, prev); 781 raw_spin_unlock_irqrestore(&devtree_lock, flags); 782 return next; 783 } 784 EXPORT_SYMBOL(of_get_next_child); 785 786 /** 787 * of_get_next_available_child - Find the next available child node 788 * @node: parent node 789 * @prev: previous child of the parent node, or NULL to get first 790 * 791 * This function is like of_get_next_child(), except that it 792 * automatically skips any disabled nodes (i.e. status = "disabled"). 793 */ 794 struct device_node *of_get_next_available_child(const struct device_node *node, 795 struct device_node *prev) 796 { 797 struct device_node *next; 798 unsigned long flags; 799 800 if (!node) 801 return NULL; 802 803 raw_spin_lock_irqsave(&devtree_lock, flags); 804 next = prev ? prev->sibling : node->child; 805 for (; next; next = next->sibling) { 806 if (!__of_device_is_available(next)) 807 continue; 808 if (of_node_get(next)) 809 break; 810 } 811 of_node_put(prev); 812 raw_spin_unlock_irqrestore(&devtree_lock, flags); 813 return next; 814 } 815 EXPORT_SYMBOL(of_get_next_available_child); 816 817 /** 818 * of_get_next_cpu_node - Iterate on cpu nodes 819 * @prev: previous child of the /cpus node, or NULL to get first 820 * 821 * Unusable CPUs (those with the status property set to "fail" or "fail-...") 822 * will be skipped. 823 * 824 * Return: A cpu node pointer with refcount incremented, use of_node_put() 825 * on it when done. Returns NULL when prev is the last child. Decrements 826 * the refcount of prev. 827 */ 828 struct device_node *of_get_next_cpu_node(struct device_node *prev) 829 { 830 struct device_node *next = NULL; 831 unsigned long flags; 832 struct device_node *node; 833 834 if (!prev) 835 node = of_find_node_by_path("/cpus"); 836 837 raw_spin_lock_irqsave(&devtree_lock, flags); 838 if (prev) 839 next = prev->sibling; 840 else if (node) { 841 next = node->child; 842 of_node_put(node); 843 } 844 for (; next; next = next->sibling) { 845 if (__of_device_is_fail(next)) 846 continue; 847 if (!(of_node_name_eq(next, "cpu") || 848 __of_node_is_type(next, "cpu"))) 849 continue; 850 if (of_node_get(next)) 851 break; 852 } 853 of_node_put(prev); 854 raw_spin_unlock_irqrestore(&devtree_lock, flags); 855 return next; 856 } 857 EXPORT_SYMBOL(of_get_next_cpu_node); 858 859 /** 860 * of_get_compatible_child - Find compatible child node 861 * @parent: parent node 862 * @compatible: compatible string 863 * 864 * Lookup child node whose compatible property contains the given compatible 865 * string. 866 * 867 * Return: a node pointer with refcount incremented, use of_node_put() on it 868 * when done; or NULL if not found. 869 */ 870 struct device_node *of_get_compatible_child(const struct device_node *parent, 871 const char *compatible) 872 { 873 struct device_node *child; 874 875 for_each_child_of_node(parent, child) { 876 if (of_device_is_compatible(child, compatible)) 877 break; 878 } 879 880 return child; 881 } 882 EXPORT_SYMBOL(of_get_compatible_child); 883 884 /** 885 * of_get_child_by_name - Find the child node by name for a given parent 886 * @node: parent node 887 * @name: child name to look for. 888 * 889 * This function looks for child node for given matching name 890 * 891 * Return: A node pointer if found, with refcount incremented, use 892 * of_node_put() on it when done. 893 * Returns NULL if node is not found. 894 */ 895 struct device_node *of_get_child_by_name(const struct device_node *node, 896 const char *name) 897 { 898 struct device_node *child; 899 900 for_each_child_of_node(node, child) 901 if (of_node_name_eq(child, name)) 902 break; 903 return child; 904 } 905 EXPORT_SYMBOL(of_get_child_by_name); 906 907 struct device_node *__of_find_node_by_path(struct device_node *parent, 908 const char *path) 909 { 910 struct device_node *child; 911 int len; 912 913 len = strcspn(path, "/:"); 914 if (!len) 915 return NULL; 916 917 __for_each_child_of_node(parent, child) { 918 const char *name = kbasename(child->full_name); 919 if (strncmp(path, name, len) == 0 && (strlen(name) == len)) 920 return child; 921 } 922 return NULL; 923 } 924 925 struct device_node *__of_find_node_by_full_path(struct device_node *node, 926 const char *path) 927 { 928 const char *separator = strchr(path, ':'); 929 930 while (node && *path == '/') { 931 struct device_node *tmp = node; 932 933 path++; /* Increment past '/' delimiter */ 934 node = __of_find_node_by_path(node, path); 935 of_node_put(tmp); 936 path = strchrnul(path, '/'); 937 if (separator && separator < path) 938 break; 939 } 940 return node; 941 } 942 943 /** 944 * of_find_node_opts_by_path - Find a node matching a full OF path 945 * @path: Either the full path to match, or if the path does not 946 * start with '/', the name of a property of the /aliases 947 * node (an alias). In the case of an alias, the node 948 * matching the alias' value will be returned. 949 * @opts: Address of a pointer into which to store the start of 950 * an options string appended to the end of the path with 951 * a ':' separator. 952 * 953 * Valid paths: 954 * * /foo/bar Full path 955 * * foo Valid alias 956 * * foo/bar Valid alias + relative path 957 * 958 * Return: A node pointer with refcount incremented, use 959 * of_node_put() on it when done. 960 */ 961 struct device_node *of_find_node_opts_by_path(const char *path, const char **opts) 962 { 963 struct device_node *np = NULL; 964 struct property *pp; 965 unsigned long flags; 966 const char *separator = strchr(path, ':'); 967 968 if (opts) 969 *opts = separator ? separator + 1 : NULL; 970 971 if (strcmp(path, "/") == 0) 972 return of_node_get(of_root); 973 974 /* The path could begin with an alias */ 975 if (*path != '/') { 976 int len; 977 const char *p = separator; 978 979 if (!p) 980 p = strchrnul(path, '/'); 981 len = p - path; 982 983 /* of_aliases must not be NULL */ 984 if (!of_aliases) 985 return NULL; 986 987 for_each_property_of_node(of_aliases, pp) { 988 if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) { 989 np = of_find_node_by_path(pp->value); 990 break; 991 } 992 } 993 if (!np) 994 return NULL; 995 path = p; 996 } 997 998 /* Step down the tree matching path components */ 999 raw_spin_lock_irqsave(&devtree_lock, flags); 1000 if (!np) 1001 np = of_node_get(of_root); 1002 np = __of_find_node_by_full_path(np, path); 1003 raw_spin_unlock_irqrestore(&devtree_lock, flags); 1004 return np; 1005 } 1006 EXPORT_SYMBOL(of_find_node_opts_by_path); 1007 1008 /** 1009 * of_find_node_by_name - Find a node by its "name" property 1010 * @from: The node to start searching from or NULL; the node 1011 * you pass will not be searched, only the next one 1012 * will. Typically, you pass what the previous call 1013 * returned. of_node_put() will be called on @from. 1014 * @name: The name string to match against 1015 * 1016 * Return: A node pointer with refcount incremented, use 1017 * of_node_put() on it when done. 1018 */ 1019 struct device_node *of_find_node_by_name(struct device_node *from, 1020 const char *name) 1021 { 1022 struct device_node *np; 1023 unsigned long flags; 1024 1025 raw_spin_lock_irqsave(&devtree_lock, flags); 1026 for_each_of_allnodes_from(from, np) 1027 if (of_node_name_eq(np, name) && of_node_get(np)) 1028 break; 1029 of_node_put(from); 1030 raw_spin_unlock_irqrestore(&devtree_lock, flags); 1031 return np; 1032 } 1033 EXPORT_SYMBOL(of_find_node_by_name); 1034 1035 /** 1036 * of_find_node_by_type - Find a node by its "device_type" property 1037 * @from: The node to start searching from, or NULL to start searching 1038 * the entire device tree. The node you pass will not be 1039 * searched, only the next one will; typically, you pass 1040 * what the previous call returned. of_node_put() will be 1041 * called on from for you. 1042 * @type: The type string to match against 1043 * 1044 * Return: A node pointer with refcount incremented, use 1045 * of_node_put() on it when done. 1046 */ 1047 struct device_node *of_find_node_by_type(struct device_node *from, 1048 const char *type) 1049 { 1050 struct device_node *np; 1051 unsigned long flags; 1052 1053 raw_spin_lock_irqsave(&devtree_lock, flags); 1054 for_each_of_allnodes_from(from, np) 1055 if (__of_node_is_type(np, type) && of_node_get(np)) 1056 break; 1057 of_node_put(from); 1058 raw_spin_unlock_irqrestore(&devtree_lock, flags); 1059 return np; 1060 } 1061 EXPORT_SYMBOL(of_find_node_by_type); 1062 1063 /** 1064 * of_find_compatible_node - Find a node based on type and one of the 1065 * tokens in its "compatible" property 1066 * @from: The node to start searching from or NULL, the node 1067 * you pass will not be searched, only the next one 1068 * will; typically, you pass what the previous call 1069 * returned. of_node_put() will be called on it 1070 * @type: The type string to match "device_type" or NULL to ignore 1071 * @compatible: The string to match to one of the tokens in the device 1072 * "compatible" list. 1073 * 1074 * Return: A node pointer with refcount incremented, use 1075 * of_node_put() on it when done. 1076 */ 1077 struct device_node *of_find_compatible_node(struct device_node *from, 1078 const char *type, const char *compatible) 1079 { 1080 struct device_node *np; 1081 unsigned long flags; 1082 1083 raw_spin_lock_irqsave(&devtree_lock, flags); 1084 for_each_of_allnodes_from(from, np) 1085 if (__of_device_is_compatible(np, compatible, type, NULL) && 1086 of_node_get(np)) 1087 break; 1088 of_node_put(from); 1089 raw_spin_unlock_irqrestore(&devtree_lock, flags); 1090 return np; 1091 } 1092 EXPORT_SYMBOL(of_find_compatible_node); 1093 1094 /** 1095 * of_find_node_with_property - Find a node which has a property with 1096 * the given name. 1097 * @from: The node to start searching from or NULL, the node 1098 * you pass will not be searched, only the next one 1099 * will; typically, you pass what the previous call 1100 * returned. of_node_put() will be called on it 1101 * @prop_name: The name of the property to look for. 1102 * 1103 * Return: A node pointer with refcount incremented, use 1104 * of_node_put() on it when done. 1105 */ 1106 struct device_node *of_find_node_with_property(struct device_node *from, 1107 const char *prop_name) 1108 { 1109 struct device_node *np; 1110 struct property *pp; 1111 unsigned long flags; 1112 1113 raw_spin_lock_irqsave(&devtree_lock, flags); 1114 for_each_of_allnodes_from(from, np) { 1115 for (pp = np->properties; pp; pp = pp->next) { 1116 if (of_prop_cmp(pp->name, prop_name) == 0) { 1117 of_node_get(np); 1118 goto out; 1119 } 1120 } 1121 } 1122 out: 1123 of_node_put(from); 1124 raw_spin_unlock_irqrestore(&devtree_lock, flags); 1125 return np; 1126 } 1127 EXPORT_SYMBOL(of_find_node_with_property); 1128 1129 static 1130 const struct of_device_id *__of_match_node(const struct of_device_id *matches, 1131 const struct device_node *node) 1132 { 1133 const struct of_device_id *best_match = NULL; 1134 int score, best_score = 0; 1135 1136 if (!matches) 1137 return NULL; 1138 1139 for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) { 1140 score = __of_device_is_compatible(node, matches->compatible, 1141 matches->type, matches->name); 1142 if (score > best_score) { 1143 best_match = matches; 1144 best_score = score; 1145 } 1146 } 1147 1148 return best_match; 1149 } 1150 1151 /** 1152 * of_match_node - Tell if a device_node has a matching of_match structure 1153 * @matches: array of of device match structures to search in 1154 * @node: the of device structure to match against 1155 * 1156 * Low level utility function used by device matching. 1157 */ 1158 const struct of_device_id *of_match_node(const struct of_device_id *matches, 1159 const struct device_node *node) 1160 { 1161 const struct of_device_id *match; 1162 unsigned long flags; 1163 1164 raw_spin_lock_irqsave(&devtree_lock, flags); 1165 match = __of_match_node(matches, node); 1166 raw_spin_unlock_irqrestore(&devtree_lock, flags); 1167 return match; 1168 } 1169 EXPORT_SYMBOL(of_match_node); 1170 1171 /** 1172 * of_find_matching_node_and_match - Find a node based on an of_device_id 1173 * match table. 1174 * @from: The node to start searching from or NULL, the node 1175 * you pass will not be searched, only the next one 1176 * will; typically, you pass what the previous call 1177 * returned. of_node_put() will be called on it 1178 * @matches: array of of device match structures to search in 1179 * @match: Updated to point at the matches entry which matched 1180 * 1181 * Return: A node pointer with refcount incremented, use 1182 * of_node_put() on it when done. 1183 */ 1184 struct device_node *of_find_matching_node_and_match(struct device_node *from, 1185 const struct of_device_id *matches, 1186 const struct of_device_id **match) 1187 { 1188 struct device_node *np; 1189 const struct of_device_id *m; 1190 unsigned long flags; 1191 1192 if (match) 1193 *match = NULL; 1194 1195 raw_spin_lock_irqsave(&devtree_lock, flags); 1196 for_each_of_allnodes_from(from, np) { 1197 m = __of_match_node(matches, np); 1198 if (m && of_node_get(np)) { 1199 if (match) 1200 *match = m; 1201 break; 1202 } 1203 } 1204 of_node_put(from); 1205 raw_spin_unlock_irqrestore(&devtree_lock, flags); 1206 return np; 1207 } 1208 EXPORT_SYMBOL(of_find_matching_node_and_match); 1209 1210 /** 1211 * of_alias_from_compatible - Lookup appropriate alias for a device node 1212 * depending on compatible 1213 * @node: pointer to a device tree node 1214 * @alias: Pointer to buffer that alias value will be copied into 1215 * @len: Length of alias value 1216 * 1217 * Based on the value of the compatible property, this routine will attempt 1218 * to choose an appropriate alias value for a particular device tree node. 1219 * It does this by stripping the manufacturer prefix (as delimited by a ',') 1220 * from the first entry in the compatible list property. 1221 * 1222 * Note: The matching on just the "product" side of the compatible is a relic 1223 * from I2C and SPI. Please do not add any new user. 1224 * 1225 * Return: This routine returns 0 on success, <0 on failure. 1226 */ 1227 int of_alias_from_compatible(const struct device_node *node, char *alias, int len) 1228 { 1229 const char *compatible, *p; 1230 int cplen; 1231 1232 compatible = of_get_property(node, "compatible", &cplen); 1233 if (!compatible || strlen(compatible) > cplen) 1234 return -ENODEV; 1235 p = strchr(compatible, ','); 1236 strscpy(alias, p ? p + 1 : compatible, len); 1237 return 0; 1238 } 1239 EXPORT_SYMBOL_GPL(of_alias_from_compatible); 1240 1241 /** 1242 * of_find_node_by_phandle - Find a node given a phandle 1243 * @handle: phandle of the node to find 1244 * 1245 * Return: A node pointer with refcount incremented, use 1246 * of_node_put() on it when done. 1247 */ 1248 struct device_node *of_find_node_by_phandle(phandle handle) 1249 { 1250 struct device_node *np = NULL; 1251 unsigned long flags; 1252 u32 handle_hash; 1253 1254 if (!handle) 1255 return NULL; 1256 1257 handle_hash = of_phandle_cache_hash(handle); 1258 1259 raw_spin_lock_irqsave(&devtree_lock, flags); 1260 1261 if (phandle_cache[handle_hash] && 1262 handle == phandle_cache[handle_hash]->phandle) 1263 np = phandle_cache[handle_hash]; 1264 1265 if (!np) { 1266 for_each_of_allnodes(np) 1267 if (np->phandle == handle && 1268 !of_node_check_flag(np, OF_DETACHED)) { 1269 phandle_cache[handle_hash] = np; 1270 break; 1271 } 1272 } 1273 1274 of_node_get(np); 1275 raw_spin_unlock_irqrestore(&devtree_lock, flags); 1276 return np; 1277 } 1278 EXPORT_SYMBOL(of_find_node_by_phandle); 1279 1280 void of_print_phandle_args(const char *msg, const struct of_phandle_args *args) 1281 { 1282 int i; 1283 printk("%s %pOF", msg, args->np); 1284 for (i = 0; i < args->args_count; i++) { 1285 const char delim = i ? ',' : ':'; 1286 1287 pr_cont("%c%08x", delim, args->args[i]); 1288 } 1289 pr_cont("\n"); 1290 } 1291 1292 int of_phandle_iterator_init(struct of_phandle_iterator *it, 1293 const struct device_node *np, 1294 const char *list_name, 1295 const char *cells_name, 1296 int cell_count) 1297 { 1298 const __be32 *list; 1299 int size; 1300 1301 memset(it, 0, sizeof(*it)); 1302 1303 /* 1304 * one of cell_count or cells_name must be provided to determine the 1305 * argument length. 1306 */ 1307 if (cell_count < 0 && !cells_name) 1308 return -EINVAL; 1309 1310 list = of_get_property(np, list_name, &size); 1311 if (!list) 1312 return -ENOENT; 1313 1314 it->cells_name = cells_name; 1315 it->cell_count = cell_count; 1316 it->parent = np; 1317 it->list_end = list + size / sizeof(*list); 1318 it->phandle_end = list; 1319 it->cur = list; 1320 1321 return 0; 1322 } 1323 EXPORT_SYMBOL_GPL(of_phandle_iterator_init); 1324 1325 int of_phandle_iterator_next(struct of_phandle_iterator *it) 1326 { 1327 uint32_t count = 0; 1328 1329 if (it->node) { 1330 of_node_put(it->node); 1331 it->node = NULL; 1332 } 1333 1334 if (!it->cur || it->phandle_end >= it->list_end) 1335 return -ENOENT; 1336 1337 it->cur = it->phandle_end; 1338 1339 /* If phandle is 0, then it is an empty entry with no arguments. */ 1340 it->phandle = be32_to_cpup(it->cur++); 1341 1342 if (it->phandle) { 1343 1344 /* 1345 * Find the provider node and parse the #*-cells property to 1346 * determine the argument length. 1347 */ 1348 it->node = of_find_node_by_phandle(it->phandle); 1349 1350 if (it->cells_name) { 1351 if (!it->node) { 1352 pr_err("%pOF: could not find phandle %d\n", 1353 it->parent, it->phandle); 1354 goto err; 1355 } 1356 1357 if (of_property_read_u32(it->node, it->cells_name, 1358 &count)) { 1359 /* 1360 * If both cell_count and cells_name is given, 1361 * fall back to cell_count in absence 1362 * of the cells_name property 1363 */ 1364 if (it->cell_count >= 0) { 1365 count = it->cell_count; 1366 } else { 1367 pr_err("%pOF: could not get %s for %pOF\n", 1368 it->parent, 1369 it->cells_name, 1370 it->node); 1371 goto err; 1372 } 1373 } 1374 } else { 1375 count = it->cell_count; 1376 } 1377 1378 /* 1379 * Make sure that the arguments actually fit in the remaining 1380 * property data length 1381 */ 1382 if (it->cur + count > it->list_end) { 1383 if (it->cells_name) 1384 pr_err("%pOF: %s = %d found %td\n", 1385 it->parent, it->cells_name, 1386 count, it->list_end - it->cur); 1387 else 1388 pr_err("%pOF: phandle %s needs %d, found %td\n", 1389 it->parent, of_node_full_name(it->node), 1390 count, it->list_end - it->cur); 1391 goto err; 1392 } 1393 } 1394 1395 it->phandle_end = it->cur + count; 1396 it->cur_count = count; 1397 1398 return 0; 1399 1400 err: 1401 if (it->node) { 1402 of_node_put(it->node); 1403 it->node = NULL; 1404 } 1405 1406 return -EINVAL; 1407 } 1408 EXPORT_SYMBOL_GPL(of_phandle_iterator_next); 1409 1410 int of_phandle_iterator_args(struct of_phandle_iterator *it, 1411 uint32_t *args, 1412 int size) 1413 { 1414 int i, count; 1415 1416 count = it->cur_count; 1417 1418 if (WARN_ON(size < count)) 1419 count = size; 1420 1421 for (i = 0; i < count; i++) 1422 args[i] = be32_to_cpup(it->cur++); 1423 1424 return count; 1425 } 1426 1427 int __of_parse_phandle_with_args(const struct device_node *np, 1428 const char *list_name, 1429 const char *cells_name, 1430 int cell_count, int index, 1431 struct of_phandle_args *out_args) 1432 { 1433 struct of_phandle_iterator it; 1434 int rc, cur_index = 0; 1435 1436 if (index < 0) 1437 return -EINVAL; 1438 1439 /* Loop over the phandles until all the requested entry is found */ 1440 of_for_each_phandle(&it, rc, np, list_name, cells_name, cell_count) { 1441 /* 1442 * All of the error cases bail out of the loop, so at 1443 * this point, the parsing is successful. If the requested 1444 * index matches, then fill the out_args structure and return, 1445 * or return -ENOENT for an empty entry. 1446 */ 1447 rc = -ENOENT; 1448 if (cur_index == index) { 1449 if (!it.phandle) 1450 goto err; 1451 1452 if (out_args) { 1453 int c; 1454 1455 c = of_phandle_iterator_args(&it, 1456 out_args->args, 1457 MAX_PHANDLE_ARGS); 1458 out_args->np = it.node; 1459 out_args->args_count = c; 1460 } else { 1461 of_node_put(it.node); 1462 } 1463 1464 /* Found it! return success */ 1465 return 0; 1466 } 1467 1468 cur_index++; 1469 } 1470 1471 /* 1472 * Unlock node before returning result; will be one of: 1473 * -ENOENT : index is for empty phandle 1474 * -EINVAL : parsing error on data 1475 */ 1476 1477 err: 1478 of_node_put(it.node); 1479 return rc; 1480 } 1481 EXPORT_SYMBOL(__of_parse_phandle_with_args); 1482 1483 /** 1484 * of_parse_phandle_with_args_map() - Find a node pointed by phandle in a list and remap it 1485 * @np: pointer to a device tree node containing a list 1486 * @list_name: property name that contains a list 1487 * @stem_name: stem of property names that specify phandles' arguments count 1488 * @index: index of a phandle to parse out 1489 * @out_args: optional pointer to output arguments structure (will be filled) 1490 * 1491 * This function is useful to parse lists of phandles and their arguments. 1492 * Returns 0 on success and fills out_args, on error returns appropriate errno 1493 * value. The difference between this function and of_parse_phandle_with_args() 1494 * is that this API remaps a phandle if the node the phandle points to has 1495 * a <@stem_name>-map property. 1496 * 1497 * Caller is responsible to call of_node_put() on the returned out_args->np 1498 * pointer. 1499 * 1500 * Example:: 1501 * 1502 * phandle1: node1 { 1503 * #list-cells = <2>; 1504 * }; 1505 * 1506 * phandle2: node2 { 1507 * #list-cells = <1>; 1508 * }; 1509 * 1510 * phandle3: node3 { 1511 * #list-cells = <1>; 1512 * list-map = <0 &phandle2 3>, 1513 * <1 &phandle2 2>, 1514 * <2 &phandle1 5 1>; 1515 * list-map-mask = <0x3>; 1516 * }; 1517 * 1518 * node4 { 1519 * list = <&phandle1 1 2 &phandle3 0>; 1520 * }; 1521 * 1522 * To get a device_node of the ``node2`` node you may call this: 1523 * of_parse_phandle_with_args(node4, "list", "list", 1, &args); 1524 */ 1525 int of_parse_phandle_with_args_map(const struct device_node *np, 1526 const char *list_name, 1527 const char *stem_name, 1528 int index, struct of_phandle_args *out_args) 1529 { 1530 char *cells_name, *map_name = NULL, *mask_name = NULL; 1531 char *pass_name = NULL; 1532 struct device_node *cur, *new = NULL; 1533 const __be32 *map, *mask, *pass; 1534 static const __be32 dummy_mask[] = { [0 ... MAX_PHANDLE_ARGS] = ~0 }; 1535 static const __be32 dummy_pass[] = { [0 ... MAX_PHANDLE_ARGS] = 0 }; 1536 __be32 initial_match_array[MAX_PHANDLE_ARGS]; 1537 const __be32 *match_array = initial_match_array; 1538 int i, ret, map_len, match; 1539 u32 list_size, new_size; 1540 1541 if (index < 0) 1542 return -EINVAL; 1543 1544 cells_name = kasprintf(GFP_KERNEL, "#%s-cells", stem_name); 1545 if (!cells_name) 1546 return -ENOMEM; 1547 1548 ret = -ENOMEM; 1549 map_name = kasprintf(GFP_KERNEL, "%s-map", stem_name); 1550 if (!map_name) 1551 goto free; 1552 1553 mask_name = kasprintf(GFP_KERNEL, "%s-map-mask", stem_name); 1554 if (!mask_name) 1555 goto free; 1556 1557 pass_name = kasprintf(GFP_KERNEL, "%s-map-pass-thru", stem_name); 1558 if (!pass_name) 1559 goto free; 1560 1561 ret = __of_parse_phandle_with_args(np, list_name, cells_name, -1, index, 1562 out_args); 1563 if (ret) 1564 goto free; 1565 1566 /* Get the #<list>-cells property */ 1567 cur = out_args->np; 1568 ret = of_property_read_u32(cur, cells_name, &list_size); 1569 if (ret < 0) 1570 goto put; 1571 1572 /* Precalculate the match array - this simplifies match loop */ 1573 for (i = 0; i < list_size; i++) 1574 initial_match_array[i] = cpu_to_be32(out_args->args[i]); 1575 1576 ret = -EINVAL; 1577 while (cur) { 1578 /* Get the <list>-map property */ 1579 map = of_get_property(cur, map_name, &map_len); 1580 if (!map) { 1581 ret = 0; 1582 goto free; 1583 } 1584 map_len /= sizeof(u32); 1585 1586 /* Get the <list>-map-mask property (optional) */ 1587 mask = of_get_property(cur, mask_name, NULL); 1588 if (!mask) 1589 mask = dummy_mask; 1590 /* Iterate through <list>-map property */ 1591 match = 0; 1592 while (map_len > (list_size + 1) && !match) { 1593 /* Compare specifiers */ 1594 match = 1; 1595 for (i = 0; i < list_size; i++, map_len--) 1596 match &= !((match_array[i] ^ *map++) & mask[i]); 1597 1598 of_node_put(new); 1599 new = of_find_node_by_phandle(be32_to_cpup(map)); 1600 map++; 1601 map_len--; 1602 1603 /* Check if not found */ 1604 if (!new) 1605 goto put; 1606 1607 if (!of_device_is_available(new)) 1608 match = 0; 1609 1610 ret = of_property_read_u32(new, cells_name, &new_size); 1611 if (ret) 1612 goto put; 1613 1614 /* Check for malformed properties */ 1615 if (WARN_ON(new_size > MAX_PHANDLE_ARGS)) 1616 goto put; 1617 if (map_len < new_size) 1618 goto put; 1619 1620 /* Move forward by new node's #<list>-cells amount */ 1621 map += new_size; 1622 map_len -= new_size; 1623 } 1624 if (!match) 1625 goto put; 1626 1627 /* Get the <list>-map-pass-thru property (optional) */ 1628 pass = of_get_property(cur, pass_name, NULL); 1629 if (!pass) 1630 pass = dummy_pass; 1631 1632 /* 1633 * Successfully parsed a <list>-map translation; copy new 1634 * specifier into the out_args structure, keeping the 1635 * bits specified in <list>-map-pass-thru. 1636 */ 1637 match_array = map - new_size; 1638 for (i = 0; i < new_size; i++) { 1639 __be32 val = *(map - new_size + i); 1640 1641 if (i < list_size) { 1642 val &= ~pass[i]; 1643 val |= cpu_to_be32(out_args->args[i]) & pass[i]; 1644 } 1645 1646 out_args->args[i] = be32_to_cpu(val); 1647 } 1648 out_args->args_count = list_size = new_size; 1649 /* Iterate again with new provider */ 1650 out_args->np = new; 1651 of_node_put(cur); 1652 cur = new; 1653 } 1654 put: 1655 of_node_put(cur); 1656 of_node_put(new); 1657 free: 1658 kfree(mask_name); 1659 kfree(map_name); 1660 kfree(cells_name); 1661 kfree(pass_name); 1662 1663 return ret; 1664 } 1665 EXPORT_SYMBOL(of_parse_phandle_with_args_map); 1666 1667 /** 1668 * of_count_phandle_with_args() - Find the number of phandles references in a property 1669 * @np: pointer to a device tree node containing a list 1670 * @list_name: property name that contains a list 1671 * @cells_name: property name that specifies phandles' arguments count 1672 * 1673 * Return: The number of phandle + argument tuples within a property. It 1674 * is a typical pattern to encode a list of phandle and variable 1675 * arguments into a single property. The number of arguments is encoded 1676 * by a property in the phandle-target node. For example, a gpios 1677 * property would contain a list of GPIO specifies consisting of a 1678 * phandle and 1 or more arguments. The number of arguments are 1679 * determined by the #gpio-cells property in the node pointed to by the 1680 * phandle. 1681 */ 1682 int of_count_phandle_with_args(const struct device_node *np, const char *list_name, 1683 const char *cells_name) 1684 { 1685 struct of_phandle_iterator it; 1686 int rc, cur_index = 0; 1687 1688 /* 1689 * If cells_name is NULL we assume a cell count of 0. This makes 1690 * counting the phandles trivial as each 32bit word in the list is a 1691 * phandle and no arguments are to consider. So we don't iterate through 1692 * the list but just use the length to determine the phandle count. 1693 */ 1694 if (!cells_name) { 1695 const __be32 *list; 1696 int size; 1697 1698 list = of_get_property(np, list_name, &size); 1699 if (!list) 1700 return -ENOENT; 1701 1702 return size / sizeof(*list); 1703 } 1704 1705 rc = of_phandle_iterator_init(&it, np, list_name, cells_name, -1); 1706 if (rc) 1707 return rc; 1708 1709 while ((rc = of_phandle_iterator_next(&it)) == 0) 1710 cur_index += 1; 1711 1712 if (rc != -ENOENT) 1713 return rc; 1714 1715 return cur_index; 1716 } 1717 EXPORT_SYMBOL(of_count_phandle_with_args); 1718 1719 /** 1720 * __of_add_property - Add a property to a node without lock operations 1721 * @np: Caller's Device Node 1722 * @prop: Property to add 1723 */ 1724 int __of_add_property(struct device_node *np, struct property *prop) 1725 { 1726 struct property **next; 1727 1728 prop->next = NULL; 1729 next = &np->properties; 1730 while (*next) { 1731 if (strcmp(prop->name, (*next)->name) == 0) 1732 /* duplicate ! don't insert it */ 1733 return -EEXIST; 1734 1735 next = &(*next)->next; 1736 } 1737 *next = prop; 1738 1739 return 0; 1740 } 1741 1742 /** 1743 * of_add_property - Add a property to a node 1744 * @np: Caller's Device Node 1745 * @prop: Property to add 1746 */ 1747 int of_add_property(struct device_node *np, struct property *prop) 1748 { 1749 unsigned long flags; 1750 int rc; 1751 1752 mutex_lock(&of_mutex); 1753 1754 raw_spin_lock_irqsave(&devtree_lock, flags); 1755 rc = __of_add_property(np, prop); 1756 raw_spin_unlock_irqrestore(&devtree_lock, flags); 1757 1758 if (!rc) 1759 __of_add_property_sysfs(np, prop); 1760 1761 mutex_unlock(&of_mutex); 1762 1763 if (!rc) 1764 of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL); 1765 1766 return rc; 1767 } 1768 EXPORT_SYMBOL_GPL(of_add_property); 1769 1770 int __of_remove_property(struct device_node *np, struct property *prop) 1771 { 1772 struct property **next; 1773 1774 for (next = &np->properties; *next; next = &(*next)->next) { 1775 if (*next == prop) 1776 break; 1777 } 1778 if (*next == NULL) 1779 return -ENODEV; 1780 1781 /* found the node */ 1782 *next = prop->next; 1783 prop->next = np->deadprops; 1784 np->deadprops = prop; 1785 1786 return 0; 1787 } 1788 1789 /** 1790 * of_remove_property - Remove a property from a node. 1791 * @np: Caller's Device Node 1792 * @prop: Property to remove 1793 * 1794 * Note that we don't actually remove it, since we have given out 1795 * who-knows-how-many pointers to the data using get-property. 1796 * Instead we just move the property to the "dead properties" 1797 * list, so it won't be found any more. 1798 */ 1799 int of_remove_property(struct device_node *np, struct property *prop) 1800 { 1801 unsigned long flags; 1802 int rc; 1803 1804 if (!prop) 1805 return -ENODEV; 1806 1807 mutex_lock(&of_mutex); 1808 1809 raw_spin_lock_irqsave(&devtree_lock, flags); 1810 rc = __of_remove_property(np, prop); 1811 raw_spin_unlock_irqrestore(&devtree_lock, flags); 1812 1813 if (!rc) 1814 __of_remove_property_sysfs(np, prop); 1815 1816 mutex_unlock(&of_mutex); 1817 1818 if (!rc) 1819 of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL); 1820 1821 return rc; 1822 } 1823 EXPORT_SYMBOL_GPL(of_remove_property); 1824 1825 int __of_update_property(struct device_node *np, struct property *newprop, 1826 struct property **oldpropp) 1827 { 1828 struct property **next, *oldprop; 1829 1830 for (next = &np->properties; *next; next = &(*next)->next) { 1831 if (of_prop_cmp((*next)->name, newprop->name) == 0) 1832 break; 1833 } 1834 *oldpropp = oldprop = *next; 1835 1836 if (oldprop) { 1837 /* replace the node */ 1838 newprop->next = oldprop->next; 1839 *next = newprop; 1840 oldprop->next = np->deadprops; 1841 np->deadprops = oldprop; 1842 } else { 1843 /* new node */ 1844 newprop->next = NULL; 1845 *next = newprop; 1846 } 1847 1848 return 0; 1849 } 1850 1851 /* 1852 * of_update_property - Update a property in a node, if the property does 1853 * not exist, add it. 1854 * 1855 * Note that we don't actually remove it, since we have given out 1856 * who-knows-how-many pointers to the data using get-property. 1857 * Instead we just move the property to the "dead properties" list, 1858 * and add the new property to the property list 1859 */ 1860 int of_update_property(struct device_node *np, struct property *newprop) 1861 { 1862 struct property *oldprop; 1863 unsigned long flags; 1864 int rc; 1865 1866 if (!newprop->name) 1867 return -EINVAL; 1868 1869 mutex_lock(&of_mutex); 1870 1871 raw_spin_lock_irqsave(&devtree_lock, flags); 1872 rc = __of_update_property(np, newprop, &oldprop); 1873 raw_spin_unlock_irqrestore(&devtree_lock, flags); 1874 1875 if (!rc) 1876 __of_update_property_sysfs(np, newprop, oldprop); 1877 1878 mutex_unlock(&of_mutex); 1879 1880 if (!rc) 1881 of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop); 1882 1883 return rc; 1884 } 1885 1886 static void of_alias_add(struct alias_prop *ap, struct device_node *np, 1887 int id, const char *stem, int stem_len) 1888 { 1889 ap->np = np; 1890 ap->id = id; 1891 strscpy(ap->stem, stem, stem_len + 1); 1892 list_add_tail(&ap->link, &aliases_lookup); 1893 pr_debug("adding DT alias:%s: stem=%s id=%i node=%pOF\n", 1894 ap->alias, ap->stem, ap->id, np); 1895 } 1896 1897 /** 1898 * of_alias_scan - Scan all properties of the 'aliases' node 1899 * @dt_alloc: An allocator that provides a virtual address to memory 1900 * for storing the resulting tree 1901 * 1902 * The function scans all the properties of the 'aliases' node and populates 1903 * the global lookup table with the properties. It returns the 1904 * number of alias properties found, or an error code in case of failure. 1905 */ 1906 void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align)) 1907 { 1908 struct property *pp; 1909 1910 of_aliases = of_find_node_by_path("/aliases"); 1911 of_chosen = of_find_node_by_path("/chosen"); 1912 if (of_chosen == NULL) 1913 of_chosen = of_find_node_by_path("/chosen@0"); 1914 1915 if (of_chosen) { 1916 /* linux,stdout-path and /aliases/stdout are for legacy compatibility */ 1917 const char *name = NULL; 1918 1919 if (of_property_read_string(of_chosen, "stdout-path", &name)) 1920 of_property_read_string(of_chosen, "linux,stdout-path", 1921 &name); 1922 if (IS_ENABLED(CONFIG_PPC) && !name) 1923 of_property_read_string(of_aliases, "stdout", &name); 1924 if (name) 1925 of_stdout = of_find_node_opts_by_path(name, &of_stdout_options); 1926 if (of_stdout) 1927 of_stdout->fwnode.flags |= FWNODE_FLAG_BEST_EFFORT; 1928 } 1929 1930 if (!of_aliases) 1931 return; 1932 1933 for_each_property_of_node(of_aliases, pp) { 1934 const char *start = pp->name; 1935 const char *end = start + strlen(start); 1936 struct device_node *np; 1937 struct alias_prop *ap; 1938 int id, len; 1939 1940 /* Skip those we do not want to proceed */ 1941 if (!strcmp(pp->name, "name") || 1942 !strcmp(pp->name, "phandle") || 1943 !strcmp(pp->name, "linux,phandle")) 1944 continue; 1945 1946 np = of_find_node_by_path(pp->value); 1947 if (!np) 1948 continue; 1949 1950 /* walk the alias backwards to extract the id and work out 1951 * the 'stem' string */ 1952 while (isdigit(*(end-1)) && end > start) 1953 end--; 1954 len = end - start; 1955 1956 if (kstrtoint(end, 10, &id) < 0) 1957 continue; 1958 1959 /* Allocate an alias_prop with enough space for the stem */ 1960 ap = dt_alloc(sizeof(*ap) + len + 1, __alignof__(*ap)); 1961 if (!ap) 1962 continue; 1963 memset(ap, 0, sizeof(*ap) + len + 1); 1964 ap->alias = start; 1965 of_alias_add(ap, np, id, start, len); 1966 } 1967 } 1968 1969 /** 1970 * of_alias_get_id - Get alias id for the given device_node 1971 * @np: Pointer to the given device_node 1972 * @stem: Alias stem of the given device_node 1973 * 1974 * The function travels the lookup table to get the alias id for the given 1975 * device_node and alias stem. 1976 * 1977 * Return: The alias id if found. 1978 */ 1979 int of_alias_get_id(struct device_node *np, const char *stem) 1980 { 1981 struct alias_prop *app; 1982 int id = -ENODEV; 1983 1984 mutex_lock(&of_mutex); 1985 list_for_each_entry(app, &aliases_lookup, link) { 1986 if (strcmp(app->stem, stem) != 0) 1987 continue; 1988 1989 if (np == app->np) { 1990 id = app->id; 1991 break; 1992 } 1993 } 1994 mutex_unlock(&of_mutex); 1995 1996 return id; 1997 } 1998 EXPORT_SYMBOL_GPL(of_alias_get_id); 1999 2000 /** 2001 * of_alias_get_highest_id - Get highest alias id for the given stem 2002 * @stem: Alias stem to be examined 2003 * 2004 * The function travels the lookup table to get the highest alias id for the 2005 * given alias stem. It returns the alias id if found. 2006 */ 2007 int of_alias_get_highest_id(const char *stem) 2008 { 2009 struct alias_prop *app; 2010 int id = -ENODEV; 2011 2012 mutex_lock(&of_mutex); 2013 list_for_each_entry(app, &aliases_lookup, link) { 2014 if (strcmp(app->stem, stem) != 0) 2015 continue; 2016 2017 if (app->id > id) 2018 id = app->id; 2019 } 2020 mutex_unlock(&of_mutex); 2021 2022 return id; 2023 } 2024 EXPORT_SYMBOL_GPL(of_alias_get_highest_id); 2025 2026 /** 2027 * of_console_check() - Test and setup console for DT setup 2028 * @dn: Pointer to device node 2029 * @name: Name to use for preferred console without index. ex. "ttyS" 2030 * @index: Index to use for preferred console. 2031 * 2032 * Check if the given device node matches the stdout-path property in the 2033 * /chosen node. If it does then register it as the preferred console. 2034 * 2035 * Return: TRUE if console successfully setup. Otherwise return FALSE. 2036 */ 2037 bool of_console_check(struct device_node *dn, char *name, int index) 2038 { 2039 if (!dn || dn != of_stdout || console_set_on_cmdline) 2040 return false; 2041 2042 /* 2043 * XXX: cast `options' to char pointer to suppress complication 2044 * warnings: printk, UART and console drivers expect char pointer. 2045 */ 2046 return !add_preferred_console(name, index, (char *)of_stdout_options); 2047 } 2048 EXPORT_SYMBOL_GPL(of_console_check); 2049 2050 /** 2051 * of_find_next_cache_node - Find a node's subsidiary cache 2052 * @np: node of type "cpu" or "cache" 2053 * 2054 * Return: A node pointer with refcount incremented, use 2055 * of_node_put() on it when done. Caller should hold a reference 2056 * to np. 2057 */ 2058 struct device_node *of_find_next_cache_node(const struct device_node *np) 2059 { 2060 struct device_node *child, *cache_node; 2061 2062 cache_node = of_parse_phandle(np, "l2-cache", 0); 2063 if (!cache_node) 2064 cache_node = of_parse_phandle(np, "next-level-cache", 0); 2065 2066 if (cache_node) 2067 return cache_node; 2068 2069 /* OF on pmac has nodes instead of properties named "l2-cache" 2070 * beneath CPU nodes. 2071 */ 2072 if (IS_ENABLED(CONFIG_PPC_PMAC) && of_node_is_type(np, "cpu")) 2073 for_each_child_of_node(np, child) 2074 if (of_node_is_type(child, "cache")) 2075 return child; 2076 2077 return NULL; 2078 } 2079 2080 /** 2081 * of_find_last_cache_level - Find the level at which the last cache is 2082 * present for the given logical cpu 2083 * 2084 * @cpu: cpu number(logical index) for which the last cache level is needed 2085 * 2086 * Return: The level at which the last cache is present. It is exactly 2087 * same as the total number of cache levels for the given logical cpu. 2088 */ 2089 int of_find_last_cache_level(unsigned int cpu) 2090 { 2091 u32 cache_level = 0; 2092 struct device_node *prev = NULL, *np = of_cpu_device_node_get(cpu); 2093 2094 while (np) { 2095 of_node_put(prev); 2096 prev = np; 2097 np = of_find_next_cache_node(np); 2098 } 2099 2100 of_property_read_u32(prev, "cache-level", &cache_level); 2101 of_node_put(prev); 2102 2103 return cache_level; 2104 } 2105 2106 /** 2107 * of_map_id - Translate an ID through a downstream mapping. 2108 * @np: root complex device node. 2109 * @id: device ID to map. 2110 * @map_name: property name of the map to use. 2111 * @map_mask_name: optional property name of the mask to use. 2112 * @target: optional pointer to a target device node. 2113 * @id_out: optional pointer to receive the translated ID. 2114 * 2115 * Given a device ID, look up the appropriate implementation-defined 2116 * platform ID and/or the target device which receives transactions on that 2117 * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or 2118 * @id_out may be NULL if only the other is required. If @target points to 2119 * a non-NULL device node pointer, only entries targeting that node will be 2120 * matched; if it points to a NULL value, it will receive the device node of 2121 * the first matching target phandle, with a reference held. 2122 * 2123 * Return: 0 on success or a standard error code on failure. 2124 */ 2125 int of_map_id(struct device_node *np, u32 id, 2126 const char *map_name, const char *map_mask_name, 2127 struct device_node **target, u32 *id_out) 2128 { 2129 u32 map_mask, masked_id; 2130 int map_len; 2131 const __be32 *map = NULL; 2132 2133 if (!np || !map_name || (!target && !id_out)) 2134 return -EINVAL; 2135 2136 map = of_get_property(np, map_name, &map_len); 2137 if (!map) { 2138 if (target) 2139 return -ENODEV; 2140 /* Otherwise, no map implies no translation */ 2141 *id_out = id; 2142 return 0; 2143 } 2144 2145 if (!map_len || map_len % (4 * sizeof(*map))) { 2146 pr_err("%pOF: Error: Bad %s length: %d\n", np, 2147 map_name, map_len); 2148 return -EINVAL; 2149 } 2150 2151 /* The default is to select all bits. */ 2152 map_mask = 0xffffffff; 2153 2154 /* 2155 * Can be overridden by "{iommu,msi}-map-mask" property. 2156 * If of_property_read_u32() fails, the default is used. 2157 */ 2158 if (map_mask_name) 2159 of_property_read_u32(np, map_mask_name, &map_mask); 2160 2161 masked_id = map_mask & id; 2162 for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) { 2163 struct device_node *phandle_node; 2164 u32 id_base = be32_to_cpup(map + 0); 2165 u32 phandle = be32_to_cpup(map + 1); 2166 u32 out_base = be32_to_cpup(map + 2); 2167 u32 id_len = be32_to_cpup(map + 3); 2168 2169 if (id_base & ~map_mask) { 2170 pr_err("%pOF: Invalid %s translation - %s-mask (0x%x) ignores id-base (0x%x)\n", 2171 np, map_name, map_name, 2172 map_mask, id_base); 2173 return -EFAULT; 2174 } 2175 2176 if (masked_id < id_base || masked_id >= id_base + id_len) 2177 continue; 2178 2179 phandle_node = of_find_node_by_phandle(phandle); 2180 if (!phandle_node) 2181 return -ENODEV; 2182 2183 if (target) { 2184 if (*target) 2185 of_node_put(phandle_node); 2186 else 2187 *target = phandle_node; 2188 2189 if (*target != phandle_node) 2190 continue; 2191 } 2192 2193 if (id_out) 2194 *id_out = masked_id - id_base + out_base; 2195 2196 pr_debug("%pOF: %s, using mask %08x, id-base: %08x, out-base: %08x, length: %08x, id: %08x -> %08x\n", 2197 np, map_name, map_mask, id_base, out_base, 2198 id_len, id, masked_id - id_base + out_base); 2199 return 0; 2200 } 2201 2202 pr_info("%pOF: no %s translation for id 0x%x on %pOF\n", np, map_name, 2203 id, target && *target ? *target : NULL); 2204 2205 /* Bypasses translation */ 2206 if (id_out) 2207 *id_out = id; 2208 return 0; 2209 } 2210 EXPORT_SYMBOL_GPL(of_map_id); 2211