1 // SPDX-License-Identifier: GPL-2.0+
3 * Procedures for creating, accessing and interpreting the device tree.
5 * Paul Mackerras August 1996.
6 * Copyright (C) 1996-2005 Paul Mackerras.
8 * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
9 * {engebret|bergner}@us.ibm.com
11 * Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
13 * Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
17 #define pr_fmt(fmt) "OF: " fmt
19 #include <linux/console.h>
20 #include <linux/ctype.h>
21 #include <linux/cpu.h>
22 #include <linux/module.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>
31 #include "of_private.h"
33 LIST_HEAD(aliases_lookup);
35 struct device_node *of_root;
36 EXPORT_SYMBOL(of_root);
37 struct device_node *of_chosen;
38 struct device_node *of_aliases;
39 struct device_node *of_stdout;
40 static const char *of_stdout_options;
45 * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
46 * This mutex must be held whenever modifications are being made to the
47 * device tree. The of_{attach,detach}_node() and
48 * of_{add,remove,update}_property() helpers make sure this happens.
50 DEFINE_MUTEX(of_mutex);
52 /* use when traversing tree through the child, sibling,
53 * or parent members of struct device_node.
55 DEFINE_RAW_SPINLOCK(devtree_lock);
57 bool of_node_name_eq(const struct device_node *np, const char *name)
59 const char *node_name;
65 node_name = kbasename(np->full_name);
66 len = strchrnul(node_name, '@') - node_name;
68 return (strlen(name) == len) && (strncmp(node_name, name, len) == 0);
70 EXPORT_SYMBOL(of_node_name_eq);
72 bool of_node_name_prefix(const struct device_node *np, const char *prefix)
77 return strncmp(kbasename(np->full_name), prefix, strlen(prefix)) == 0;
79 EXPORT_SYMBOL(of_node_name_prefix);
81 int of_n_addr_cells(struct device_node *np)
88 if (!of_property_read_u32(np, "#address-cells", &cells))
91 /* No #address-cells property for the root node */
92 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
94 EXPORT_SYMBOL(of_n_addr_cells);
96 int of_n_size_cells(struct device_node *np)
103 if (!of_property_read_u32(np, "#size-cells", &cells))
105 } while (np->parent);
106 /* No #size-cells property for the root node */
107 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
109 EXPORT_SYMBOL(of_n_size_cells);
112 int __weak of_node_to_nid(struct device_node *np)
118 static struct device_node **phandle_cache;
119 static u32 phandle_cache_mask;
122 * Assumptions behind phandle_cache implementation:
123 * - phandle property values are in a contiguous range of 1..n
125 * If the assumptions do not hold, then
126 * - the phandle lookup overhead reduction provided by the cache
127 * will likely be less
129 void of_populate_phandle_cache(void)
133 struct device_node *np;
136 raw_spin_lock_irqsave(&devtree_lock, flags);
138 kfree(phandle_cache);
139 phandle_cache = NULL;
141 for_each_of_allnodes(np)
142 if (np->phandle && np->phandle != OF_PHANDLE_ILLEGAL)
148 cache_entries = roundup_pow_of_two(phandles);
149 phandle_cache_mask = cache_entries - 1;
151 phandle_cache = kcalloc(cache_entries, sizeof(*phandle_cache),
156 for_each_of_allnodes(np)
157 if (np->phandle && np->phandle != OF_PHANDLE_ILLEGAL)
158 phandle_cache[np->phandle & phandle_cache_mask] = np;
161 raw_spin_unlock_irqrestore(&devtree_lock, flags);
164 int of_free_phandle_cache(void)
168 raw_spin_lock_irqsave(&devtree_lock, flags);
170 kfree(phandle_cache);
171 phandle_cache = NULL;
173 raw_spin_unlock_irqrestore(&devtree_lock, flags);
177 #if !defined(CONFIG_MODULES)
178 late_initcall_sync(of_free_phandle_cache);
181 void __init of_core_init(void)
183 struct device_node *np;
185 of_populate_phandle_cache();
187 /* Create the kset, and register existing nodes */
188 mutex_lock(&of_mutex);
189 of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
191 mutex_unlock(&of_mutex);
192 pr_err("failed to register existing nodes\n");
195 for_each_of_allnodes(np)
196 __of_attach_node_sysfs(np);
197 mutex_unlock(&of_mutex);
199 /* Symlink in /proc as required by userspace ABI */
201 proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
204 static struct property *__of_find_property(const struct device_node *np,
205 const char *name, int *lenp)
212 for (pp = np->properties; pp; pp = pp->next) {
213 if (of_prop_cmp(pp->name, name) == 0) {
223 struct property *of_find_property(const struct device_node *np,
230 raw_spin_lock_irqsave(&devtree_lock, flags);
231 pp = __of_find_property(np, name, lenp);
232 raw_spin_unlock_irqrestore(&devtree_lock, flags);
236 EXPORT_SYMBOL(of_find_property);
238 struct device_node *__of_find_all_nodes(struct device_node *prev)
240 struct device_node *np;
243 } else if (prev->child) {
246 /* Walk back up looking for a sibling, or the end of the structure */
248 while (np->parent && !np->sibling)
250 np = np->sibling; /* Might be null at the end of the tree */
256 * of_find_all_nodes - Get next node in global list
257 * @prev: Previous node or NULL to start iteration
258 * of_node_put() will be called on it
260 * Returns a node pointer with refcount incremented, use
261 * of_node_put() on it when done.
263 struct device_node *of_find_all_nodes(struct device_node *prev)
265 struct device_node *np;
268 raw_spin_lock_irqsave(&devtree_lock, flags);
269 np = __of_find_all_nodes(prev);
272 raw_spin_unlock_irqrestore(&devtree_lock, flags);
275 EXPORT_SYMBOL(of_find_all_nodes);
278 * Find a property with a given name for a given node
279 * and return the value.
281 const void *__of_get_property(const struct device_node *np,
282 const char *name, int *lenp)
284 struct property *pp = __of_find_property(np, name, lenp);
286 return pp ? pp->value : NULL;
290 * Find a property with a given name for a given node
291 * and return the value.
293 const void *of_get_property(const struct device_node *np, const char *name,
296 struct property *pp = of_find_property(np, name, lenp);
298 return pp ? pp->value : NULL;
300 EXPORT_SYMBOL(of_get_property);
303 * arch_match_cpu_phys_id - Match the given logical CPU and physical id
305 * @cpu: logical cpu index of a core/thread
306 * @phys_id: physical identifier of a core/thread
308 * CPU logical to physical index mapping is architecture specific.
309 * However this __weak function provides a default match of physical
310 * id to logical cpu index. phys_id provided here is usually values read
311 * from the device tree which must match the hardware internal registers.
313 * Returns true if the physical identifier and the logical cpu index
314 * correspond to the same core/thread, false otherwise.
316 bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
318 return (u32)phys_id == cpu;
322 * Checks if the given "prop_name" property holds the physical id of the
323 * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
324 * NULL, local thread number within the core is returned in it.
326 static bool __of_find_n_match_cpu_property(struct device_node *cpun,
327 const char *prop_name, int cpu, unsigned int *thread)
330 int ac, prop_len, tid;
333 ac = of_n_addr_cells(cpun);
334 cell = of_get_property(cpun, prop_name, &prop_len);
335 if (!cell && !ac && arch_match_cpu_phys_id(cpu, 0))
339 prop_len /= sizeof(*cell) * ac;
340 for (tid = 0; tid < prop_len; tid++) {
341 hwid = of_read_number(cell, ac);
342 if (arch_match_cpu_phys_id(cpu, hwid)) {
353 * arch_find_n_match_cpu_physical_id - See if the given device node is
354 * for the cpu corresponding to logical cpu 'cpu'. Return true if so,
355 * else false. If 'thread' is non-NULL, the local thread number within the
356 * core is returned in it.
358 bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
359 int cpu, unsigned int *thread)
361 /* Check for non-standard "ibm,ppc-interrupt-server#s" property
362 * for thread ids on PowerPC. If it doesn't exist fallback to
363 * standard "reg" property.
365 if (IS_ENABLED(CONFIG_PPC) &&
366 __of_find_n_match_cpu_property(cpun,
367 "ibm,ppc-interrupt-server#s",
371 return __of_find_n_match_cpu_property(cpun, "reg", cpu, thread);
375 * of_get_cpu_node - Get device node associated with the given logical CPU
377 * @cpu: CPU number(logical index) for which device node is required
378 * @thread: if not NULL, local thread number within the physical core is
381 * The main purpose of this function is to retrieve the device node for the
382 * given logical CPU index. It should be used to initialize the of_node in
383 * cpu device. Once of_node in cpu device is populated, all the further
384 * references can use that instead.
386 * CPU logical to physical index mapping is architecture specific and is built
387 * before booting secondary cores. This function uses arch_match_cpu_phys_id
388 * which can be overridden by architecture specific implementation.
390 * Returns a node pointer for the logical cpu with refcount incremented, use
391 * of_node_put() on it when done. Returns NULL if not found.
393 struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
395 struct device_node *cpun;
397 for_each_of_cpu_node(cpun) {
398 if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
403 EXPORT_SYMBOL(of_get_cpu_node);
406 * of_cpu_node_to_id: Get the logical CPU number for a given device_node
408 * @cpu_node: Pointer to the device_node for CPU.
410 * Returns the logical CPU number of the given CPU device_node.
411 * Returns -ENODEV if the CPU is not found.
413 int of_cpu_node_to_id(struct device_node *cpu_node)
417 struct device_node *np;
419 for_each_possible_cpu(cpu) {
420 np = of_cpu_device_node_get(cpu);
421 found = (cpu_node == np);
429 EXPORT_SYMBOL(of_cpu_node_to_id);
432 * __of_device_is_compatible() - Check if the node matches given constraints
433 * @device: pointer to node
434 * @compat: required compatible string, NULL or "" for any match
435 * @type: required device_type value, NULL or "" for any match
436 * @name: required node name, NULL or "" for any match
438 * Checks if the given @compat, @type and @name strings match the
439 * properties of the given @device. A constraints can be skipped by
440 * passing NULL or an empty string as the constraint.
442 * Returns 0 for no match, and a positive integer on match. The return
443 * value is a relative score with larger values indicating better
444 * matches. The score is weighted for the most specific compatible value
445 * to get the highest score. Matching type is next, followed by matching
446 * name. Practically speaking, this results in the following priority
449 * 1. specific compatible && type && name
450 * 2. specific compatible && type
451 * 3. specific compatible && name
452 * 4. specific compatible
453 * 5. general compatible && type && name
454 * 6. general compatible && type
455 * 7. general compatible && name
456 * 8. general compatible
461 static int __of_device_is_compatible(const struct device_node *device,
462 const char *compat, const char *type, const char *name)
464 struct property *prop;
466 int index = 0, score = 0;
468 /* Compatible match has highest priority */
469 if (compat && compat[0]) {
470 prop = __of_find_property(device, "compatible", NULL);
471 for (cp = of_prop_next_string(prop, NULL); cp;
472 cp = of_prop_next_string(prop, cp), index++) {
473 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
474 score = INT_MAX/2 - (index << 2);
482 /* Matching type is better than matching name */
483 if (type && type[0]) {
484 if (!device->type || of_node_cmp(type, device->type))
489 /* Matching name is a bit better than not */
490 if (name && name[0]) {
491 if (!device->name || of_node_cmp(name, device->name))
499 /** Checks if the given "compat" string matches one of the strings in
500 * the device's "compatible" property
502 int of_device_is_compatible(const struct device_node *device,
508 raw_spin_lock_irqsave(&devtree_lock, flags);
509 res = __of_device_is_compatible(device, compat, NULL, NULL);
510 raw_spin_unlock_irqrestore(&devtree_lock, flags);
513 EXPORT_SYMBOL(of_device_is_compatible);
515 /** Checks if the device is compatible with any of the entries in
516 * a NULL terminated array of strings. Returns the best match
519 int of_device_compatible_match(struct device_node *device,
520 const char *const *compat)
522 unsigned int tmp, score = 0;
528 tmp = of_device_is_compatible(device, *compat);
538 * of_machine_is_compatible - Test root of device tree for a given compatible value
539 * @compat: compatible string to look for in root node's compatible property.
541 * Returns a positive integer if the root node has the given value in its
542 * compatible property.
544 int of_machine_is_compatible(const char *compat)
546 struct device_node *root;
549 root = of_find_node_by_path("/");
551 rc = of_device_is_compatible(root, compat);
556 EXPORT_SYMBOL(of_machine_is_compatible);
559 * __of_device_is_available - check if a device is available for use
561 * @device: Node to check for availability, with locks already held
563 * Returns true if the status property is absent or set to "okay" or "ok",
566 static bool __of_device_is_available(const struct device_node *device)
574 status = __of_get_property(device, "status", &statlen);
579 if (!strcmp(status, "okay") || !strcmp(status, "ok"))
587 * of_device_is_available - check if a device is available for use
589 * @device: Node to check for availability
591 * Returns true if the status property is absent or set to "okay" or "ok",
594 bool of_device_is_available(const struct device_node *device)
599 raw_spin_lock_irqsave(&devtree_lock, flags);
600 res = __of_device_is_available(device);
601 raw_spin_unlock_irqrestore(&devtree_lock, flags);
605 EXPORT_SYMBOL(of_device_is_available);
608 * of_device_is_big_endian - check if a device has BE registers
610 * @device: Node to check for endianness
612 * Returns true if the device has a "big-endian" property, or if the kernel
613 * was compiled for BE *and* the device has a "native-endian" property.
614 * Returns false otherwise.
616 * Callers would nominally use ioread32be/iowrite32be if
617 * of_device_is_big_endian() == true, or readl/writel otherwise.
619 bool of_device_is_big_endian(const struct device_node *device)
621 if (of_property_read_bool(device, "big-endian"))
623 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
624 of_property_read_bool(device, "native-endian"))
628 EXPORT_SYMBOL(of_device_is_big_endian);
631 * of_get_parent - Get a node's parent if any
632 * @node: Node to get parent
634 * Returns a node pointer with refcount incremented, use
635 * of_node_put() on it when done.
637 struct device_node *of_get_parent(const struct device_node *node)
639 struct device_node *np;
645 raw_spin_lock_irqsave(&devtree_lock, flags);
646 np = of_node_get(node->parent);
647 raw_spin_unlock_irqrestore(&devtree_lock, flags);
650 EXPORT_SYMBOL(of_get_parent);
653 * of_get_next_parent - Iterate to a node's parent
654 * @node: Node to get parent of
656 * This is like of_get_parent() except that it drops the
657 * refcount on the passed node, making it suitable for iterating
658 * through a node's parents.
660 * Returns a node pointer with refcount incremented, use
661 * of_node_put() on it when done.
663 struct device_node *of_get_next_parent(struct device_node *node)
665 struct device_node *parent;
671 raw_spin_lock_irqsave(&devtree_lock, flags);
672 parent = of_node_get(node->parent);
674 raw_spin_unlock_irqrestore(&devtree_lock, flags);
677 EXPORT_SYMBOL(of_get_next_parent);
679 static struct device_node *__of_get_next_child(const struct device_node *node,
680 struct device_node *prev)
682 struct device_node *next;
687 next = prev ? prev->sibling : node->child;
688 for (; next; next = next->sibling)
689 if (of_node_get(next))
694 #define __for_each_child_of_node(parent, child) \
695 for (child = __of_get_next_child(parent, NULL); child != NULL; \
696 child = __of_get_next_child(parent, child))
699 * of_get_next_child - Iterate a node childs
701 * @prev: previous child of the parent node, or NULL to get first
703 * Returns a node pointer with refcount incremented, use of_node_put() on
704 * it when done. Returns NULL when prev is the last child. Decrements the
707 struct device_node *of_get_next_child(const struct device_node *node,
708 struct device_node *prev)
710 struct device_node *next;
713 raw_spin_lock_irqsave(&devtree_lock, flags);
714 next = __of_get_next_child(node, prev);
715 raw_spin_unlock_irqrestore(&devtree_lock, flags);
718 EXPORT_SYMBOL(of_get_next_child);
721 * of_get_next_available_child - Find the next available child node
723 * @prev: previous child of the parent node, or NULL to get first
725 * This function is like of_get_next_child(), except that it
726 * automatically skips any disabled nodes (i.e. status = "disabled").
728 struct device_node *of_get_next_available_child(const struct device_node *node,
729 struct device_node *prev)
731 struct device_node *next;
737 raw_spin_lock_irqsave(&devtree_lock, flags);
738 next = prev ? prev->sibling : node->child;
739 for (; next; next = next->sibling) {
740 if (!__of_device_is_available(next))
742 if (of_node_get(next))
746 raw_spin_unlock_irqrestore(&devtree_lock, flags);
749 EXPORT_SYMBOL(of_get_next_available_child);
752 * of_get_next_cpu_node - Iterate on cpu nodes
753 * @prev: previous child of the /cpus node, or NULL to get first
755 * Returns a cpu node pointer with refcount incremented, use of_node_put()
756 * on it when done. Returns NULL when prev is the last child. Decrements
757 * the refcount of prev.
759 struct device_node *of_get_next_cpu_node(struct device_node *prev)
761 struct device_node *next = NULL;
763 struct device_node *node;
766 node = of_find_node_by_path("/cpus");
768 raw_spin_lock_irqsave(&devtree_lock, flags);
770 next = prev->sibling;
775 for (; next; next = next->sibling) {
776 if (!(of_node_name_eq(next, "cpu") ||
777 (next->type && !of_node_cmp(next->type, "cpu"))))
779 if (!__of_device_is_available(next))
781 if (of_node_get(next))
785 raw_spin_unlock_irqrestore(&devtree_lock, flags);
788 EXPORT_SYMBOL(of_get_next_cpu_node);
791 * of_get_compatible_child - Find compatible child node
792 * @parent: parent node
793 * @compatible: compatible string
795 * Lookup child node whose compatible property contains the given compatible
798 * Returns a node pointer with refcount incremented, use of_node_put() on it
799 * when done; or NULL if not found.
801 struct device_node *of_get_compatible_child(const struct device_node *parent,
802 const char *compatible)
804 struct device_node *child;
806 for_each_child_of_node(parent, child) {
807 if (of_device_is_compatible(child, compatible))
813 EXPORT_SYMBOL(of_get_compatible_child);
816 * of_get_child_by_name - Find the child node by name for a given parent
818 * @name: child name to look for.
820 * This function looks for child node for given matching name
822 * Returns a node pointer if found, with refcount incremented, use
823 * of_node_put() on it when done.
824 * Returns NULL if node is not found.
826 struct device_node *of_get_child_by_name(const struct device_node *node,
829 struct device_node *child;
831 for_each_child_of_node(node, child)
832 if (child->name && (of_node_cmp(child->name, name) == 0))
836 EXPORT_SYMBOL(of_get_child_by_name);
838 struct device_node *__of_find_node_by_path(struct device_node *parent,
841 struct device_node *child;
844 len = strcspn(path, "/:");
848 __for_each_child_of_node(parent, child) {
849 const char *name = kbasename(child->full_name);
850 if (strncmp(path, name, len) == 0 && (strlen(name) == len))
856 struct device_node *__of_find_node_by_full_path(struct device_node *node,
859 const char *separator = strchr(path, ':');
861 while (node && *path == '/') {
862 struct device_node *tmp = node;
864 path++; /* Increment past '/' delimiter */
865 node = __of_find_node_by_path(node, path);
867 path = strchrnul(path, '/');
868 if (separator && separator < path)
875 * of_find_node_opts_by_path - Find a node matching a full OF path
876 * @path: Either the full path to match, or if the path does not
877 * start with '/', the name of a property of the /aliases
878 * node (an alias). In the case of an alias, the node
879 * matching the alias' value will be returned.
880 * @opts: Address of a pointer into which to store the start of
881 * an options string appended to the end of the path with
887 * foo/bar Valid alias + relative path
889 * Returns a node pointer with refcount incremented, use
890 * of_node_put() on it when done.
892 struct device_node *of_find_node_opts_by_path(const char *path, const char **opts)
894 struct device_node *np = NULL;
897 const char *separator = strchr(path, ':');
900 *opts = separator ? separator + 1 : NULL;
902 if (strcmp(path, "/") == 0)
903 return of_node_get(of_root);
905 /* The path could begin with an alias */
908 const char *p = separator;
911 p = strchrnul(path, '/');
914 /* of_aliases must not be NULL */
918 for_each_property_of_node(of_aliases, pp) {
919 if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
920 np = of_find_node_by_path(pp->value);
929 /* Step down the tree matching path components */
930 raw_spin_lock_irqsave(&devtree_lock, flags);
932 np = of_node_get(of_root);
933 np = __of_find_node_by_full_path(np, path);
934 raw_spin_unlock_irqrestore(&devtree_lock, flags);
937 EXPORT_SYMBOL(of_find_node_opts_by_path);
940 * of_find_node_by_name - Find a node by its "name" property
941 * @from: The node to start searching from or NULL; the node
942 * you pass will not be searched, only the next one
943 * will. Typically, you pass what the previous call
944 * returned. of_node_put() will be called on @from.
945 * @name: The name string to match against
947 * Returns a node pointer with refcount incremented, use
948 * of_node_put() on it when done.
950 struct device_node *of_find_node_by_name(struct device_node *from,
953 struct device_node *np;
956 raw_spin_lock_irqsave(&devtree_lock, flags);
957 for_each_of_allnodes_from(from, np)
958 if (np->name && (of_node_cmp(np->name, name) == 0)
962 raw_spin_unlock_irqrestore(&devtree_lock, flags);
965 EXPORT_SYMBOL(of_find_node_by_name);
968 * of_find_node_by_type - Find a node by its "device_type" property
969 * @from: The node to start searching from, or NULL to start searching
970 * the entire device tree. The node you pass will not be
971 * searched, only the next one will; typically, you pass
972 * what the previous call returned. of_node_put() will be
973 * called on from for you.
974 * @type: The type string to match against
976 * Returns a node pointer with refcount incremented, use
977 * of_node_put() on it when done.
979 struct device_node *of_find_node_by_type(struct device_node *from,
982 struct device_node *np;
985 raw_spin_lock_irqsave(&devtree_lock, flags);
986 for_each_of_allnodes_from(from, np)
987 if (np->type && (of_node_cmp(np->type, type) == 0)
991 raw_spin_unlock_irqrestore(&devtree_lock, flags);
994 EXPORT_SYMBOL(of_find_node_by_type);
997 * of_find_compatible_node - Find a node based on type and one of the
998 * tokens in its "compatible" property
999 * @from: The node to start searching from or NULL, the node
1000 * you pass will not be searched, only the next one
1001 * will; typically, you pass what the previous call
1002 * returned. of_node_put() will be called on it
1003 * @type: The type string to match "device_type" or NULL to ignore
1004 * @compatible: The string to match to one of the tokens in the device
1005 * "compatible" list.
1007 * Returns a node pointer with refcount incremented, use
1008 * of_node_put() on it when done.
1010 struct device_node *of_find_compatible_node(struct device_node *from,
1011 const char *type, const char *compatible)
1013 struct device_node *np;
1014 unsigned long flags;
1016 raw_spin_lock_irqsave(&devtree_lock, flags);
1017 for_each_of_allnodes_from(from, np)
1018 if (__of_device_is_compatible(np, compatible, type, NULL) &&
1022 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1025 EXPORT_SYMBOL(of_find_compatible_node);
1028 * of_find_node_with_property - Find a node which has a property with
1030 * @from: The node to start searching from or NULL, the node
1031 * you pass will not be searched, only the next one
1032 * will; typically, you pass what the previous call
1033 * returned. of_node_put() will be called on it
1034 * @prop_name: The name of the property to look for.
1036 * Returns a node pointer with refcount incremented, use
1037 * of_node_put() on it when done.
1039 struct device_node *of_find_node_with_property(struct device_node *from,
1040 const char *prop_name)
1042 struct device_node *np;
1043 struct property *pp;
1044 unsigned long flags;
1046 raw_spin_lock_irqsave(&devtree_lock, flags);
1047 for_each_of_allnodes_from(from, np) {
1048 for (pp = np->properties; pp; pp = pp->next) {
1049 if (of_prop_cmp(pp->name, prop_name) == 0) {
1057 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1060 EXPORT_SYMBOL(of_find_node_with_property);
1063 const struct of_device_id *__of_match_node(const struct of_device_id *matches,
1064 const struct device_node *node)
1066 const struct of_device_id *best_match = NULL;
1067 int score, best_score = 0;
1072 for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
1073 score = __of_device_is_compatible(node, matches->compatible,
1074 matches->type, matches->name);
1075 if (score > best_score) {
1076 best_match = matches;
1085 * of_match_node - Tell if a device_node has a matching of_match structure
1086 * @matches: array of of device match structures to search in
1087 * @node: the of device structure to match against
1089 * Low level utility function used by device matching.
1091 const struct of_device_id *of_match_node(const struct of_device_id *matches,
1092 const struct device_node *node)
1094 const struct of_device_id *match;
1095 unsigned long flags;
1097 raw_spin_lock_irqsave(&devtree_lock, flags);
1098 match = __of_match_node(matches, node);
1099 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1102 EXPORT_SYMBOL(of_match_node);
1105 * of_find_matching_node_and_match - Find a node based on an of_device_id
1107 * @from: The node to start searching from or NULL, the node
1108 * you pass will not be searched, only the next one
1109 * will; typically, you pass what the previous call
1110 * returned. of_node_put() will be called on it
1111 * @matches: array of of device match structures to search in
1112 * @match Updated to point at the matches entry which matched
1114 * Returns a node pointer with refcount incremented, use
1115 * of_node_put() on it when done.
1117 struct device_node *of_find_matching_node_and_match(struct device_node *from,
1118 const struct of_device_id *matches,
1119 const struct of_device_id **match)
1121 struct device_node *np;
1122 const struct of_device_id *m;
1123 unsigned long flags;
1128 raw_spin_lock_irqsave(&devtree_lock, flags);
1129 for_each_of_allnodes_from(from, np) {
1130 m = __of_match_node(matches, np);
1131 if (m && of_node_get(np)) {
1138 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1141 EXPORT_SYMBOL(of_find_matching_node_and_match);
1144 * of_modalias_node - Lookup appropriate modalias for a device node
1145 * @node: pointer to a device tree node
1146 * @modalias: Pointer to buffer that modalias value will be copied into
1147 * @len: Length of modalias value
1149 * Based on the value of the compatible property, this routine will attempt
1150 * to choose an appropriate modalias value for a particular device tree node.
1151 * It does this by stripping the manufacturer prefix (as delimited by a ',')
1152 * from the first entry in the compatible list property.
1154 * This routine returns 0 on success, <0 on failure.
1156 int of_modalias_node(struct device_node *node, char *modalias, int len)
1158 const char *compatible, *p;
1161 compatible = of_get_property(node, "compatible", &cplen);
1162 if (!compatible || strlen(compatible) > cplen)
1164 p = strchr(compatible, ',');
1165 strlcpy(modalias, p ? p + 1 : compatible, len);
1168 EXPORT_SYMBOL_GPL(of_modalias_node);
1171 * of_find_node_by_phandle - Find a node given a phandle
1172 * @handle: phandle of the node to find
1174 * Returns a node pointer with refcount incremented, use
1175 * of_node_put() on it when done.
1177 struct device_node *of_find_node_by_phandle(phandle handle)
1179 struct device_node *np = NULL;
1180 unsigned long flags;
1181 phandle masked_handle;
1186 raw_spin_lock_irqsave(&devtree_lock, flags);
1188 masked_handle = handle & phandle_cache_mask;
1190 if (phandle_cache) {
1191 if (phandle_cache[masked_handle] &&
1192 handle == phandle_cache[masked_handle]->phandle)
1193 np = phandle_cache[masked_handle];
1197 for_each_of_allnodes(np)
1198 if (np->phandle == handle) {
1200 phandle_cache[masked_handle] = np;
1206 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1209 EXPORT_SYMBOL(of_find_node_by_phandle);
1211 void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
1214 printk("%s %pOF", msg, args->np);
1215 for (i = 0; i < args->args_count; i++) {
1216 const char delim = i ? ',' : ':';
1218 pr_cont("%c%08x", delim, args->args[i]);
1223 int of_phandle_iterator_init(struct of_phandle_iterator *it,
1224 const struct device_node *np,
1225 const char *list_name,
1226 const char *cells_name,
1232 memset(it, 0, sizeof(*it));
1234 list = of_get_property(np, list_name, &size);
1238 it->cells_name = cells_name;
1239 it->cell_count = cell_count;
1241 it->list_end = list + size / sizeof(*list);
1242 it->phandle_end = list;
1247 EXPORT_SYMBOL_GPL(of_phandle_iterator_init);
1249 int of_phandle_iterator_next(struct of_phandle_iterator *it)
1254 of_node_put(it->node);
1258 if (!it->cur || it->phandle_end >= it->list_end)
1261 it->cur = it->phandle_end;
1263 /* If phandle is 0, then it is an empty entry with no arguments. */
1264 it->phandle = be32_to_cpup(it->cur++);
1269 * Find the provider node and parse the #*-cells property to
1270 * determine the argument length.
1272 it->node = of_find_node_by_phandle(it->phandle);
1274 if (it->cells_name) {
1276 pr_err("%pOF: could not find phandle\n",
1281 if (of_property_read_u32(it->node, it->cells_name,
1283 pr_err("%pOF: could not get %s for %pOF\n",
1290 count = it->cell_count;
1294 * Make sure that the arguments actually fit in the remaining
1295 * property data length
1297 if (it->cur + count > it->list_end) {
1298 pr_err("%pOF: arguments longer than property\n",
1304 it->phandle_end = it->cur + count;
1305 it->cur_count = count;
1311 of_node_put(it->node);
1317 EXPORT_SYMBOL_GPL(of_phandle_iterator_next);
1319 int of_phandle_iterator_args(struct of_phandle_iterator *it,
1325 count = it->cur_count;
1327 if (WARN_ON(size < count))
1330 for (i = 0; i < count; i++)
1331 args[i] = be32_to_cpup(it->cur++);
1336 static int __of_parse_phandle_with_args(const struct device_node *np,
1337 const char *list_name,
1338 const char *cells_name,
1339 int cell_count, int index,
1340 struct of_phandle_args *out_args)
1342 struct of_phandle_iterator it;
1343 int rc, cur_index = 0;
1345 /* Loop over the phandles until all the requested entry is found */
1346 of_for_each_phandle(&it, rc, np, list_name, cells_name, cell_count) {
1348 * All of the error cases bail out of the loop, so at
1349 * this point, the parsing is successful. If the requested
1350 * index matches, then fill the out_args structure and return,
1351 * or return -ENOENT for an empty entry.
1354 if (cur_index == index) {
1361 c = of_phandle_iterator_args(&it,
1364 out_args->np = it.node;
1365 out_args->args_count = c;
1367 of_node_put(it.node);
1370 /* Found it! return success */
1378 * Unlock node before returning result; will be one of:
1379 * -ENOENT : index is for empty phandle
1380 * -EINVAL : parsing error on data
1384 of_node_put(it.node);
1389 * of_parse_phandle - Resolve a phandle property to a device_node pointer
1390 * @np: Pointer to device node holding phandle property
1391 * @phandle_name: Name of property holding a phandle value
1392 * @index: For properties holding a table of phandles, this is the index into
1395 * Returns the device_node pointer with refcount incremented. Use
1396 * of_node_put() on it when done.
1398 struct device_node *of_parse_phandle(const struct device_node *np,
1399 const char *phandle_name, int index)
1401 struct of_phandle_args args;
1406 if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0,
1412 EXPORT_SYMBOL(of_parse_phandle);
1415 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
1416 * @np: pointer to a device tree node containing a list
1417 * @list_name: property name that contains a list
1418 * @cells_name: property name that specifies phandles' arguments count
1419 * @index: index of a phandle to parse out
1420 * @out_args: optional pointer to output arguments structure (will be filled)
1422 * This function is useful to parse lists of phandles and their arguments.
1423 * Returns 0 on success and fills out_args, on error returns appropriate
1426 * Caller is responsible to call of_node_put() on the returned out_args->np
1432 * #list-cells = <2>;
1436 * #list-cells = <1>;
1440 * list = <&phandle1 1 2 &phandle2 3>;
1443 * To get a device_node of the `node2' node you may call this:
1444 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
1446 int of_parse_phandle_with_args(const struct device_node *np, const char *list_name,
1447 const char *cells_name, int index,
1448 struct of_phandle_args *out_args)
1452 return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
1455 EXPORT_SYMBOL(of_parse_phandle_with_args);
1458 * of_parse_phandle_with_args_map() - Find a node pointed by phandle in a list and remap it
1459 * @np: pointer to a device tree node containing a list
1460 * @list_name: property name that contains a list
1461 * @stem_name: stem of property names that specify phandles' arguments count
1462 * @index: index of a phandle to parse out
1463 * @out_args: optional pointer to output arguments structure (will be filled)
1465 * This function is useful to parse lists of phandles and their arguments.
1466 * Returns 0 on success and fills out_args, on error returns appropriate errno
1467 * value. The difference between this function and of_parse_phandle_with_args()
1468 * is that this API remaps a phandle if the node the phandle points to has
1469 * a <@stem_name>-map property.
1471 * Caller is responsible to call of_node_put() on the returned out_args->np
1477 * #list-cells = <2>;
1481 * #list-cells = <1>;
1485 * #list-cells = <1>;
1486 * list-map = <0 &phandle2 3>,
1488 * <2 &phandle1 5 1>;
1489 * list-map-mask = <0x3>;
1493 * list = <&phandle1 1 2 &phandle3 0>;
1496 * To get a device_node of the `node2' node you may call this:
1497 * of_parse_phandle_with_args(node4, "list", "list", 1, &args);
1499 int of_parse_phandle_with_args_map(const struct device_node *np,
1500 const char *list_name,
1501 const char *stem_name,
1502 int index, struct of_phandle_args *out_args)
1504 char *cells_name, *map_name = NULL, *mask_name = NULL;
1505 char *pass_name = NULL;
1506 struct device_node *cur, *new = NULL;
1507 const __be32 *map, *mask, *pass;
1508 static const __be32 dummy_mask[] = { [0 ... MAX_PHANDLE_ARGS] = ~0 };
1509 static const __be32 dummy_pass[] = { [0 ... MAX_PHANDLE_ARGS] = 0 };
1510 __be32 initial_match_array[MAX_PHANDLE_ARGS];
1511 const __be32 *match_array = initial_match_array;
1512 int i, ret, map_len, match;
1513 u32 list_size, new_size;
1518 cells_name = kasprintf(GFP_KERNEL, "#%s-cells", stem_name);
1523 map_name = kasprintf(GFP_KERNEL, "%s-map", stem_name);
1527 mask_name = kasprintf(GFP_KERNEL, "%s-map-mask", stem_name);
1531 pass_name = kasprintf(GFP_KERNEL, "%s-map-pass-thru", stem_name);
1535 ret = __of_parse_phandle_with_args(np, list_name, cells_name, 0, index,
1540 /* Get the #<list>-cells property */
1542 ret = of_property_read_u32(cur, cells_name, &list_size);
1546 /* Precalculate the match array - this simplifies match loop */
1547 for (i = 0; i < list_size; i++)
1548 initial_match_array[i] = cpu_to_be32(out_args->args[i]);
1552 /* Get the <list>-map property */
1553 map = of_get_property(cur, map_name, &map_len);
1558 map_len /= sizeof(u32);
1560 /* Get the <list>-map-mask property (optional) */
1561 mask = of_get_property(cur, mask_name, NULL);
1564 /* Iterate through <list>-map property */
1566 while (map_len > (list_size + 1) && !match) {
1567 /* Compare specifiers */
1569 for (i = 0; i < list_size; i++, map_len--)
1570 match &= !((match_array[i] ^ *map++) & mask[i]);
1573 new = of_find_node_by_phandle(be32_to_cpup(map));
1577 /* Check if not found */
1581 if (!of_device_is_available(new))
1584 ret = of_property_read_u32(new, cells_name, &new_size);
1588 /* Check for malformed properties */
1589 if (WARN_ON(new_size > MAX_PHANDLE_ARGS))
1591 if (map_len < new_size)
1594 /* Move forward by new node's #<list>-cells amount */
1596 map_len -= new_size;
1601 /* Get the <list>-map-pass-thru property (optional) */
1602 pass = of_get_property(cur, pass_name, NULL);
1607 * Successfully parsed a <list>-map translation; copy new
1608 * specifier into the out_args structure, keeping the
1609 * bits specified in <list>-map-pass-thru.
1611 match_array = map - new_size;
1612 for (i = 0; i < new_size; i++) {
1613 __be32 val = *(map - new_size + i);
1615 if (i < list_size) {
1617 val |= cpu_to_be32(out_args->args[i]) & pass[i];
1620 out_args->args[i] = be32_to_cpu(val);
1622 out_args->args_count = list_size = new_size;
1623 /* Iterate again with new provider */
1639 EXPORT_SYMBOL(of_parse_phandle_with_args_map);
1642 * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
1643 * @np: pointer to a device tree node containing a list
1644 * @list_name: property name that contains a list
1645 * @cell_count: number of argument cells following the phandle
1646 * @index: index of a phandle to parse out
1647 * @out_args: optional pointer to output arguments structure (will be filled)
1649 * This function is useful to parse lists of phandles and their arguments.
1650 * Returns 0 on success and fills out_args, on error returns appropriate
1653 * Caller is responsible to call of_node_put() on the returned out_args->np
1665 * list = <&phandle1 0 2 &phandle2 2 3>;
1668 * To get a device_node of the `node2' node you may call this:
1669 * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
1671 int of_parse_phandle_with_fixed_args(const struct device_node *np,
1672 const char *list_name, int cell_count,
1673 int index, struct of_phandle_args *out_args)
1677 return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
1680 EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);
1683 * of_count_phandle_with_args() - Find the number of phandles references in a property
1684 * @np: pointer to a device tree node containing a list
1685 * @list_name: property name that contains a list
1686 * @cells_name: property name that specifies phandles' arguments count
1688 * Returns the number of phandle + argument tuples within a property. It
1689 * is a typical pattern to encode a list of phandle and variable
1690 * arguments into a single property. The number of arguments is encoded
1691 * by a property in the phandle-target node. For example, a gpios
1692 * property would contain a list of GPIO specifies consisting of a
1693 * phandle and 1 or more arguments. The number of arguments are
1694 * determined by the #gpio-cells property in the node pointed to by the
1697 int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1698 const char *cells_name)
1700 struct of_phandle_iterator it;
1701 int rc, cur_index = 0;
1703 rc = of_phandle_iterator_init(&it, np, list_name, cells_name, 0);
1707 while ((rc = of_phandle_iterator_next(&it)) == 0)
1715 EXPORT_SYMBOL(of_count_phandle_with_args);
1718 * __of_add_property - Add a property to a node without lock operations
1720 int __of_add_property(struct device_node *np, struct property *prop)
1722 struct property **next;
1725 next = &np->properties;
1727 if (strcmp(prop->name, (*next)->name) == 0)
1728 /* duplicate ! don't insert it */
1731 next = &(*next)->next;
1739 * of_add_property - Add a property to a node
1741 int of_add_property(struct device_node *np, struct property *prop)
1743 unsigned long flags;
1746 mutex_lock(&of_mutex);
1748 raw_spin_lock_irqsave(&devtree_lock, flags);
1749 rc = __of_add_property(np, prop);
1750 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1753 __of_add_property_sysfs(np, prop);
1755 mutex_unlock(&of_mutex);
1758 of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
1763 int __of_remove_property(struct device_node *np, struct property *prop)
1765 struct property **next;
1767 for (next = &np->properties; *next; next = &(*next)->next) {
1774 /* found the node */
1776 prop->next = np->deadprops;
1777 np->deadprops = prop;
1783 * of_remove_property - Remove a property from a node.
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"
1788 * list, so it won't be found any more.
1790 int of_remove_property(struct device_node *np, struct property *prop)
1792 unsigned long flags;
1798 mutex_lock(&of_mutex);
1800 raw_spin_lock_irqsave(&devtree_lock, flags);
1801 rc = __of_remove_property(np, prop);
1802 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1805 __of_remove_property_sysfs(np, prop);
1807 mutex_unlock(&of_mutex);
1810 of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
1815 int __of_update_property(struct device_node *np, struct property *newprop,
1816 struct property **oldpropp)
1818 struct property **next, *oldprop;
1820 for (next = &np->properties; *next; next = &(*next)->next) {
1821 if (of_prop_cmp((*next)->name, newprop->name) == 0)
1824 *oldpropp = oldprop = *next;
1827 /* replace the node */
1828 newprop->next = oldprop->next;
1830 oldprop->next = np->deadprops;
1831 np->deadprops = oldprop;
1834 newprop->next = NULL;
1842 * of_update_property - Update a property in a node, if the property does
1843 * not exist, add it.
1845 * Note that we don't actually remove it, since we have given out
1846 * who-knows-how-many pointers to the data using get-property.
1847 * Instead we just move the property to the "dead properties" list,
1848 * and add the new property to the property list
1850 int of_update_property(struct device_node *np, struct property *newprop)
1852 struct property *oldprop;
1853 unsigned long flags;
1859 mutex_lock(&of_mutex);
1861 raw_spin_lock_irqsave(&devtree_lock, flags);
1862 rc = __of_update_property(np, newprop, &oldprop);
1863 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1866 __of_update_property_sysfs(np, newprop, oldprop);
1868 mutex_unlock(&of_mutex);
1871 of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
1876 static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1877 int id, const char *stem, int stem_len)
1881 strncpy(ap->stem, stem, stem_len);
1882 ap->stem[stem_len] = 0;
1883 list_add_tail(&ap->link, &aliases_lookup);
1884 pr_debug("adding DT alias:%s: stem=%s id=%i node=%pOF\n",
1885 ap->alias, ap->stem, ap->id, np);
1889 * of_alias_scan - Scan all properties of the 'aliases' node
1891 * The function scans all the properties of the 'aliases' node and populates
1892 * the global lookup table with the properties. It returns the
1893 * number of alias properties found, or an error code in case of failure.
1895 * @dt_alloc: An allocator that provides a virtual address to memory
1896 * for storing the resulting tree
1898 void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1900 struct property *pp;
1902 of_aliases = of_find_node_by_path("/aliases");
1903 of_chosen = of_find_node_by_path("/chosen");
1904 if (of_chosen == NULL)
1905 of_chosen = of_find_node_by_path("/chosen@0");
1908 /* linux,stdout-path and /aliases/stdout are for legacy compatibility */
1909 const char *name = NULL;
1911 if (of_property_read_string(of_chosen, "stdout-path", &name))
1912 of_property_read_string(of_chosen, "linux,stdout-path",
1914 if (IS_ENABLED(CONFIG_PPC) && !name)
1915 of_property_read_string(of_aliases, "stdout", &name);
1917 of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
1923 for_each_property_of_node(of_aliases, pp) {
1924 const char *start = pp->name;
1925 const char *end = start + strlen(start);
1926 struct device_node *np;
1927 struct alias_prop *ap;
1930 /* Skip those we do not want to proceed */
1931 if (!strcmp(pp->name, "name") ||
1932 !strcmp(pp->name, "phandle") ||
1933 !strcmp(pp->name, "linux,phandle"))
1936 np = of_find_node_by_path(pp->value);
1940 /* walk the alias backwards to extract the id and work out
1941 * the 'stem' string */
1942 while (isdigit(*(end-1)) && end > start)
1946 if (kstrtoint(end, 10, &id) < 0)
1949 /* Allocate an alias_prop with enough space for the stem */
1950 ap = dt_alloc(sizeof(*ap) + len + 1, __alignof__(*ap));
1953 memset(ap, 0, sizeof(*ap) + len + 1);
1955 of_alias_add(ap, np, id, start, len);
1960 * of_alias_get_id - Get alias id for the given device_node
1961 * @np: Pointer to the given device_node
1962 * @stem: Alias stem of the given device_node
1964 * The function travels the lookup table to get the alias id for the given
1965 * device_node and alias stem. It returns the alias id if found.
1967 int of_alias_get_id(struct device_node *np, const char *stem)
1969 struct alias_prop *app;
1972 mutex_lock(&of_mutex);
1973 list_for_each_entry(app, &aliases_lookup, link) {
1974 if (strcmp(app->stem, stem) != 0)
1977 if (np == app->np) {
1982 mutex_unlock(&of_mutex);
1986 EXPORT_SYMBOL_GPL(of_alias_get_id);
1989 * of_alias_get_highest_id - Get highest alias id for the given stem
1990 * @stem: Alias stem to be examined
1992 * The function travels the lookup table to get the highest alias id for the
1993 * given alias stem. It returns the alias id if found.
1995 int of_alias_get_highest_id(const char *stem)
1997 struct alias_prop *app;
2000 mutex_lock(&of_mutex);
2001 list_for_each_entry(app, &aliases_lookup, link) {
2002 if (strcmp(app->stem, stem) != 0)
2008 mutex_unlock(&of_mutex);
2012 EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
2015 * of_console_check() - Test and setup console for DT setup
2016 * @dn - Pointer to device node
2017 * @name - Name to use for preferred console without index. ex. "ttyS"
2018 * @index - Index to use for preferred console.
2020 * Check if the given device node matches the stdout-path property in the
2021 * /chosen node. If it does then register it as the preferred console and return
2022 * TRUE. Otherwise return FALSE.
2024 bool of_console_check(struct device_node *dn, char *name, int index)
2026 if (!dn || dn != of_stdout || console_set_on_cmdline)
2030 * XXX: cast `options' to char pointer to suppress complication
2031 * warnings: printk, UART and console drivers expect char pointer.
2033 return !add_preferred_console(name, index, (char *)of_stdout_options);
2035 EXPORT_SYMBOL_GPL(of_console_check);
2038 * of_find_next_cache_node - Find a node's subsidiary cache
2039 * @np: node of type "cpu" or "cache"
2041 * Returns a node pointer with refcount incremented, use
2042 * of_node_put() on it when done. Caller should hold a reference
2045 struct device_node *of_find_next_cache_node(const struct device_node *np)
2047 struct device_node *child, *cache_node;
2049 cache_node = of_parse_phandle(np, "l2-cache", 0);
2051 cache_node = of_parse_phandle(np, "next-level-cache", 0);
2056 /* OF on pmac has nodes instead of properties named "l2-cache"
2057 * beneath CPU nodes.
2059 if (IS_ENABLED(CONFIG_PPC_PMAC) && !strcmp(np->type, "cpu"))
2060 for_each_child_of_node(np, child)
2061 if (!strcmp(child->type, "cache"))
2068 * of_find_last_cache_level - Find the level at which the last cache is
2069 * present for the given logical cpu
2071 * @cpu: cpu number(logical index) for which the last cache level is needed
2073 * Returns the the level at which the last cache is present. It is exactly
2074 * same as the total number of cache levels for the given logical cpu.
2076 int of_find_last_cache_level(unsigned int cpu)
2078 u32 cache_level = 0;
2079 struct device_node *prev = NULL, *np = of_cpu_device_node_get(cpu);
2084 np = of_find_next_cache_node(np);
2087 of_property_read_u32(prev, "cache-level", &cache_level);