2 * Procedures for creating, accessing and interpreting the device tree.
4 * Paul Mackerras August 1996.
5 * Copyright (C) 1996-2005 Paul Mackerras.
7 * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
8 * {engebret|bergner}@us.ibm.com
10 * Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
12 * Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License
17 * as published by the Free Software Foundation; either version
18 * 2 of the License, or (at your option) any later version.
20 #include <linux/console.h>
21 #include <linux/ctype.h>
22 #include <linux/cpu.h>
23 #include <linux/module.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;
44 * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
45 * This mutex must be held whenever modifications are being made to the
46 * device tree. The of_{attach,detach}_node() and
47 * of_{add,remove,update}_property() helpers make sure this happens.
49 DEFINE_MUTEX(of_mutex);
51 /* use when traversing tree through the child, sibling,
52 * or parent members of struct device_node.
54 DEFINE_RAW_SPINLOCK(devtree_lock);
56 int of_n_addr_cells(struct device_node *np)
63 ip = of_get_property(np, "#address-cells", NULL);
65 return be32_to_cpup(ip);
67 /* No #address-cells property for the root node */
68 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
70 EXPORT_SYMBOL(of_n_addr_cells);
72 int of_n_size_cells(struct device_node *np)
79 ip = of_get_property(np, "#size-cells", NULL);
81 return be32_to_cpup(ip);
83 /* No #size-cells property for the root node */
84 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
86 EXPORT_SYMBOL(of_n_size_cells);
89 int __weak of_node_to_nid(struct device_node *np)
91 return numa_node_id();
95 #ifndef CONFIG_OF_DYNAMIC
96 static void of_node_release(struct kobject *kobj)
98 /* Without CONFIG_OF_DYNAMIC, no nodes gets freed */
100 #endif /* CONFIG_OF_DYNAMIC */
102 struct kobj_type of_node_ktype = {
103 .release = of_node_release,
106 static ssize_t of_node_property_read(struct file *filp, struct kobject *kobj,
107 struct bin_attribute *bin_attr, char *buf,
108 loff_t offset, size_t count)
110 struct property *pp = container_of(bin_attr, struct property, attr);
111 return memory_read_from_buffer(buf, count, &offset, pp->value, pp->length);
114 static const char *safe_name(struct kobject *kobj, const char *orig_name)
116 const char *name = orig_name;
117 struct kernfs_node *kn;
120 /* don't be a hero. After 16 tries give up */
121 while (i < 16 && (kn = sysfs_get_dirent(kobj->sd, name))) {
123 if (name != orig_name)
125 name = kasprintf(GFP_KERNEL, "%s#%i", orig_name, ++i);
128 if (name != orig_name)
129 pr_warn("device-tree: Duplicate name in %s, renamed to \"%s\"\n",
130 kobject_name(kobj), name);
134 int __of_add_property_sysfs(struct device_node *np, struct property *pp)
138 /* Important: Don't leak passwords */
139 bool secure = strncmp(pp->name, "security-", 9) == 0;
141 if (!IS_ENABLED(CONFIG_SYSFS))
144 if (!of_kset || !of_node_is_attached(np))
147 sysfs_bin_attr_init(&pp->attr);
148 pp->attr.attr.name = safe_name(&np->kobj, pp->name);
149 pp->attr.attr.mode = secure ? S_IRUSR : S_IRUGO;
150 pp->attr.size = secure ? 0 : pp->length;
151 pp->attr.read = of_node_property_read;
153 rc = sysfs_create_bin_file(&np->kobj, &pp->attr);
154 WARN(rc, "error adding attribute %s to node %s\n", pp->name, np->full_name);
158 int __of_attach_node_sysfs(struct device_node *np)
164 if (!IS_ENABLED(CONFIG_SYSFS))
170 np->kobj.kset = of_kset;
172 /* Nodes without parents are new top level trees */
173 rc = kobject_add(&np->kobj, NULL, "%s",
174 safe_name(&of_kset->kobj, "base"));
176 name = safe_name(&np->parent->kobj, kbasename(np->full_name));
177 if (!name || !name[0])
180 rc = kobject_add(&np->kobj, &np->parent->kobj, "%s", name);
185 for_each_property_of_node(np, pp)
186 __of_add_property_sysfs(np, pp);
191 static int __init of_init(void)
193 struct device_node *np;
195 /* Create the kset, and register existing nodes */
196 mutex_lock(&of_mutex);
197 of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
199 mutex_unlock(&of_mutex);
202 for_each_of_allnodes(np)
203 __of_attach_node_sysfs(np);
204 mutex_unlock(&of_mutex);
206 /* Symlink in /proc as required by userspace ABI */
208 proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
212 core_initcall(of_init);
214 static struct property *__of_find_property(const struct device_node *np,
215 const char *name, int *lenp)
222 for (pp = np->properties; pp; pp = pp->next) {
223 if (of_prop_cmp(pp->name, name) == 0) {
233 struct property *of_find_property(const struct device_node *np,
240 raw_spin_lock_irqsave(&devtree_lock, flags);
241 pp = __of_find_property(np, name, lenp);
242 raw_spin_unlock_irqrestore(&devtree_lock, flags);
246 EXPORT_SYMBOL(of_find_property);
248 struct device_node *__of_find_all_nodes(struct device_node *prev)
250 struct device_node *np;
253 } else if (prev->child) {
256 /* Walk back up looking for a sibling, or the end of the structure */
258 while (np->parent && !np->sibling)
260 np = np->sibling; /* Might be null at the end of the tree */
266 * of_find_all_nodes - Get next node in global list
267 * @prev: Previous node or NULL to start iteration
268 * of_node_put() will be called on it
270 * Returns a node pointer with refcount incremented, use
271 * of_node_put() on it when done.
273 struct device_node *of_find_all_nodes(struct device_node *prev)
275 struct device_node *np;
278 raw_spin_lock_irqsave(&devtree_lock, flags);
279 np = __of_find_all_nodes(prev);
282 raw_spin_unlock_irqrestore(&devtree_lock, flags);
285 EXPORT_SYMBOL(of_find_all_nodes);
288 * Find a property with a given name for a given node
289 * and return the value.
291 const void *__of_get_property(const struct device_node *np,
292 const char *name, int *lenp)
294 struct property *pp = __of_find_property(np, name, lenp);
296 return pp ? pp->value : NULL;
300 * Find a property with a given name for a given node
301 * and return the value.
303 const void *of_get_property(const struct device_node *np, const char *name,
306 struct property *pp = of_find_property(np, name, lenp);
308 return pp ? pp->value : NULL;
310 EXPORT_SYMBOL(of_get_property);
313 * arch_match_cpu_phys_id - Match the given logical CPU and physical id
315 * @cpu: logical cpu index of a core/thread
316 * @phys_id: physical identifier of a core/thread
318 * CPU logical to physical index mapping is architecture specific.
319 * However this __weak function provides a default match of physical
320 * id to logical cpu index. phys_id provided here is usually values read
321 * from the device tree which must match the hardware internal registers.
323 * Returns true if the physical identifier and the logical cpu index
324 * correspond to the same core/thread, false otherwise.
326 bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
328 return (u32)phys_id == cpu;
332 * Checks if the given "prop_name" property holds the physical id of the
333 * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
334 * NULL, local thread number within the core is returned in it.
336 static bool __of_find_n_match_cpu_property(struct device_node *cpun,
337 const char *prop_name, int cpu, unsigned int *thread)
340 int ac, prop_len, tid;
343 ac = of_n_addr_cells(cpun);
344 cell = of_get_property(cpun, prop_name, &prop_len);
347 prop_len /= sizeof(*cell) * ac;
348 for (tid = 0; tid < prop_len; tid++) {
349 hwid = of_read_number(cell, ac);
350 if (arch_match_cpu_phys_id(cpu, hwid)) {
361 * arch_find_n_match_cpu_physical_id - See if the given device node is
362 * for the cpu corresponding to logical cpu 'cpu'. Return true if so,
363 * else false. If 'thread' is non-NULL, the local thread number within the
364 * core is returned in it.
366 bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
367 int cpu, unsigned int *thread)
369 /* Check for non-standard "ibm,ppc-interrupt-server#s" property
370 * for thread ids on PowerPC. If it doesn't exist fallback to
371 * standard "reg" property.
373 if (IS_ENABLED(CONFIG_PPC) &&
374 __of_find_n_match_cpu_property(cpun,
375 "ibm,ppc-interrupt-server#s",
379 if (__of_find_n_match_cpu_property(cpun, "reg", cpu, thread))
386 * of_get_cpu_node - Get device node associated with the given logical CPU
388 * @cpu: CPU number(logical index) for which device node is required
389 * @thread: if not NULL, local thread number within the physical core is
392 * The main purpose of this function is to retrieve the device node for the
393 * given logical CPU index. It should be used to initialize the of_node in
394 * cpu device. Once of_node in cpu device is populated, all the further
395 * references can use that instead.
397 * CPU logical to physical index mapping is architecture specific and is built
398 * before booting secondary cores. This function uses arch_match_cpu_phys_id
399 * which can be overridden by architecture specific implementation.
401 * Returns a node pointer for the logical cpu if found, else NULL.
403 struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
405 struct device_node *cpun;
407 for_each_node_by_type(cpun, "cpu") {
408 if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
413 EXPORT_SYMBOL(of_get_cpu_node);
416 * __of_device_is_compatible() - Check if the node matches given constraints
417 * @device: pointer to node
418 * @compat: required compatible string, NULL or "" for any match
419 * @type: required device_type value, NULL or "" for any match
420 * @name: required node name, NULL or "" for any match
422 * Checks if the given @compat, @type and @name strings match the
423 * properties of the given @device. A constraints can be skipped by
424 * passing NULL or an empty string as the constraint.
426 * Returns 0 for no match, and a positive integer on match. The return
427 * value is a relative score with larger values indicating better
428 * matches. The score is weighted for the most specific compatible value
429 * to get the highest score. Matching type is next, followed by matching
430 * name. Practically speaking, this results in the following priority
433 * 1. specific compatible && type && name
434 * 2. specific compatible && type
435 * 3. specific compatible && name
436 * 4. specific compatible
437 * 5. general compatible && type && name
438 * 6. general compatible && type
439 * 7. general compatible && name
440 * 8. general compatible
445 static int __of_device_is_compatible(const struct device_node *device,
446 const char *compat, const char *type, const char *name)
448 struct property *prop;
450 int index = 0, score = 0;
452 /* Compatible match has highest priority */
453 if (compat && compat[0]) {
454 prop = __of_find_property(device, "compatible", NULL);
455 for (cp = of_prop_next_string(prop, NULL); cp;
456 cp = of_prop_next_string(prop, cp), index++) {
457 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
458 score = INT_MAX/2 - (index << 2);
466 /* Matching type is better than matching name */
467 if (type && type[0]) {
468 if (!device->type || of_node_cmp(type, device->type))
473 /* Matching name is a bit better than not */
474 if (name && name[0]) {
475 if (!device->name || of_node_cmp(name, device->name))
483 /** Checks if the given "compat" string matches one of the strings in
484 * the device's "compatible" property
486 int of_device_is_compatible(const struct device_node *device,
492 raw_spin_lock_irqsave(&devtree_lock, flags);
493 res = __of_device_is_compatible(device, compat, NULL, NULL);
494 raw_spin_unlock_irqrestore(&devtree_lock, flags);
497 EXPORT_SYMBOL(of_device_is_compatible);
500 * of_machine_is_compatible - Test root of device tree for a given compatible value
501 * @compat: compatible string to look for in root node's compatible property.
503 * Returns true if the root node has the given value in its
504 * compatible property.
506 int of_machine_is_compatible(const char *compat)
508 struct device_node *root;
511 root = of_find_node_by_path("/");
513 rc = of_device_is_compatible(root, compat);
518 EXPORT_SYMBOL(of_machine_is_compatible);
521 * __of_device_is_available - check if a device is available for use
523 * @device: Node to check for availability, with locks already held
525 * Returns 1 if the status property is absent or set to "okay" or "ok",
528 static int __of_device_is_available(const struct device_node *device)
536 status = __of_get_property(device, "status", &statlen);
541 if (!strcmp(status, "okay") || !strcmp(status, "ok"))
549 * of_device_is_available - check if a device is available for use
551 * @device: Node to check for availability
553 * Returns 1 if the status property is absent or set to "okay" or "ok",
556 int of_device_is_available(const struct device_node *device)
561 raw_spin_lock_irqsave(&devtree_lock, flags);
562 res = __of_device_is_available(device);
563 raw_spin_unlock_irqrestore(&devtree_lock, flags);
567 EXPORT_SYMBOL(of_device_is_available);
570 * of_get_parent - Get a node's parent if any
571 * @node: Node to get parent
573 * Returns a node pointer with refcount incremented, use
574 * of_node_put() on it when done.
576 struct device_node *of_get_parent(const struct device_node *node)
578 struct device_node *np;
584 raw_spin_lock_irqsave(&devtree_lock, flags);
585 np = of_node_get(node->parent);
586 raw_spin_unlock_irqrestore(&devtree_lock, flags);
589 EXPORT_SYMBOL(of_get_parent);
592 * of_get_next_parent - Iterate to a node's parent
593 * @node: Node to get parent of
595 * This is like of_get_parent() except that it drops the
596 * refcount on the passed node, making it suitable for iterating
597 * through a node's parents.
599 * Returns a node pointer with refcount incremented, use
600 * of_node_put() on it when done.
602 struct device_node *of_get_next_parent(struct device_node *node)
604 struct device_node *parent;
610 raw_spin_lock_irqsave(&devtree_lock, flags);
611 parent = of_node_get(node->parent);
613 raw_spin_unlock_irqrestore(&devtree_lock, flags);
616 EXPORT_SYMBOL(of_get_next_parent);
618 static struct device_node *__of_get_next_child(const struct device_node *node,
619 struct device_node *prev)
621 struct device_node *next;
626 next = prev ? prev->sibling : node->child;
627 for (; next; next = next->sibling)
628 if (of_node_get(next))
633 #define __for_each_child_of_node(parent, child) \
634 for (child = __of_get_next_child(parent, NULL); child != NULL; \
635 child = __of_get_next_child(parent, child))
638 * of_get_next_child - Iterate a node childs
640 * @prev: previous child of the parent node, or NULL to get first
642 * Returns a node pointer with refcount incremented, use
643 * of_node_put() on it when done.
645 struct device_node *of_get_next_child(const struct device_node *node,
646 struct device_node *prev)
648 struct device_node *next;
651 raw_spin_lock_irqsave(&devtree_lock, flags);
652 next = __of_get_next_child(node, prev);
653 raw_spin_unlock_irqrestore(&devtree_lock, flags);
656 EXPORT_SYMBOL(of_get_next_child);
659 * of_get_next_available_child - Find the next available child node
661 * @prev: previous child of the parent node, or NULL to get first
663 * This function is like of_get_next_child(), except that it
664 * automatically skips any disabled nodes (i.e. status = "disabled").
666 struct device_node *of_get_next_available_child(const struct device_node *node,
667 struct device_node *prev)
669 struct device_node *next;
675 raw_spin_lock_irqsave(&devtree_lock, flags);
676 next = prev ? prev->sibling : node->child;
677 for (; next; next = next->sibling) {
678 if (!__of_device_is_available(next))
680 if (of_node_get(next))
684 raw_spin_unlock_irqrestore(&devtree_lock, flags);
687 EXPORT_SYMBOL(of_get_next_available_child);
690 * of_get_child_by_name - Find the child node by name for a given parent
692 * @name: child name to look for.
694 * This function looks for child node for given matching name
696 * Returns a node pointer if found, with refcount incremented, use
697 * of_node_put() on it when done.
698 * Returns NULL if node is not found.
700 struct device_node *of_get_child_by_name(const struct device_node *node,
703 struct device_node *child;
705 for_each_child_of_node(node, child)
706 if (child->name && (of_node_cmp(child->name, name) == 0))
710 EXPORT_SYMBOL(of_get_child_by_name);
712 static struct device_node *__of_find_node_by_path(struct device_node *parent,
715 struct device_node *child;
716 int len = strchrnul(path, '/') - path;
721 __for_each_child_of_node(parent, child) {
722 const char *name = strrchr(child->full_name, '/');
723 if (WARN(!name, "malformed device_node %s\n", child->full_name))
726 if (strncmp(path, name, len) == 0 && (strlen(name) == len))
733 * of_find_node_by_path - Find a node matching a full OF path
734 * @path: Either the full path to match, or if the path does not
735 * start with '/', the name of a property of the /aliases
736 * node (an alias). In the case of an alias, the node
737 * matching the alias' value will be returned.
742 * foo/bar Valid alias + relative path
744 * Returns a node pointer with refcount incremented, use
745 * of_node_put() on it when done.
747 struct device_node *of_find_node_by_path(const char *path)
749 struct device_node *np = NULL;
753 if (strcmp(path, "/") == 0)
754 return of_node_get(of_root);
756 /* The path could begin with an alias */
758 char *p = strchrnul(path, '/');
761 /* of_aliases must not be NULL */
765 for_each_property_of_node(of_aliases, pp) {
766 if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
767 np = of_find_node_by_path(pp->value);
776 /* Step down the tree matching path components */
777 raw_spin_lock_irqsave(&devtree_lock, flags);
779 np = of_node_get(of_root);
780 while (np && *path == '/') {
781 path++; /* Increment past '/' delimiter */
782 np = __of_find_node_by_path(np, path);
783 path = strchrnul(path, '/');
785 raw_spin_unlock_irqrestore(&devtree_lock, flags);
788 EXPORT_SYMBOL(of_find_node_by_path);
791 * of_find_node_by_name - Find a node by its "name" property
792 * @from: The node to start searching from or NULL, the node
793 * you pass will not be searched, only the next one
794 * will; typically, you pass what the previous call
795 * returned. of_node_put() will be called on it
796 * @name: The name string to match against
798 * Returns a node pointer with refcount incremented, use
799 * of_node_put() on it when done.
801 struct device_node *of_find_node_by_name(struct device_node *from,
804 struct device_node *np;
807 raw_spin_lock_irqsave(&devtree_lock, flags);
808 for_each_of_allnodes_from(from, np)
809 if (np->name && (of_node_cmp(np->name, name) == 0)
813 raw_spin_unlock_irqrestore(&devtree_lock, flags);
816 EXPORT_SYMBOL(of_find_node_by_name);
819 * of_find_node_by_type - Find a node by its "device_type" property
820 * @from: The node to start searching from, or NULL to start searching
821 * the entire device tree. The node you pass will not be
822 * searched, only the next one will; typically, you pass
823 * what the previous call returned. of_node_put() will be
824 * called on from for you.
825 * @type: The type string to match against
827 * Returns a node pointer with refcount incremented, use
828 * of_node_put() on it when done.
830 struct device_node *of_find_node_by_type(struct device_node *from,
833 struct device_node *np;
836 raw_spin_lock_irqsave(&devtree_lock, flags);
837 for_each_of_allnodes_from(from, np)
838 if (np->type && (of_node_cmp(np->type, type) == 0)
842 raw_spin_unlock_irqrestore(&devtree_lock, flags);
845 EXPORT_SYMBOL(of_find_node_by_type);
848 * of_find_compatible_node - Find a node based on type and one of the
849 * tokens in its "compatible" property
850 * @from: The node to start searching from or NULL, the node
851 * you pass will not be searched, only the next one
852 * will; typically, you pass what the previous call
853 * returned. of_node_put() will be called on it
854 * @type: The type string to match "device_type" or NULL to ignore
855 * @compatible: The string to match to one of the tokens in the device
858 * Returns a node pointer with refcount incremented, use
859 * of_node_put() on it when done.
861 struct device_node *of_find_compatible_node(struct device_node *from,
862 const char *type, const char *compatible)
864 struct device_node *np;
867 raw_spin_lock_irqsave(&devtree_lock, flags);
868 for_each_of_allnodes_from(from, np)
869 if (__of_device_is_compatible(np, compatible, type, NULL) &&
873 raw_spin_unlock_irqrestore(&devtree_lock, flags);
876 EXPORT_SYMBOL(of_find_compatible_node);
879 * of_find_node_with_property - Find a node which has a property with
881 * @from: The node to start searching from or NULL, the node
882 * you pass will not be searched, only the next one
883 * will; typically, you pass what the previous call
884 * returned. of_node_put() will be called on it
885 * @prop_name: The name of the property to look for.
887 * Returns a node pointer with refcount incremented, use
888 * of_node_put() on it when done.
890 struct device_node *of_find_node_with_property(struct device_node *from,
891 const char *prop_name)
893 struct device_node *np;
897 raw_spin_lock_irqsave(&devtree_lock, flags);
898 for_each_of_allnodes_from(from, np) {
899 for (pp = np->properties; pp; pp = pp->next) {
900 if (of_prop_cmp(pp->name, prop_name) == 0) {
908 raw_spin_unlock_irqrestore(&devtree_lock, flags);
911 EXPORT_SYMBOL(of_find_node_with_property);
914 const struct of_device_id *__of_match_node(const struct of_device_id *matches,
915 const struct device_node *node)
917 const struct of_device_id *best_match = NULL;
918 int score, best_score = 0;
923 for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
924 score = __of_device_is_compatible(node, matches->compatible,
925 matches->type, matches->name);
926 if (score > best_score) {
927 best_match = matches;
936 * of_match_node - Tell if an device_node has a matching of_match structure
937 * @matches: array of of device match structures to search in
938 * @node: the of device structure to match against
940 * Low level utility function used by device matching.
942 const struct of_device_id *of_match_node(const struct of_device_id *matches,
943 const struct device_node *node)
945 const struct of_device_id *match;
948 raw_spin_lock_irqsave(&devtree_lock, flags);
949 match = __of_match_node(matches, node);
950 raw_spin_unlock_irqrestore(&devtree_lock, flags);
953 EXPORT_SYMBOL(of_match_node);
956 * of_find_matching_node_and_match - Find a node based on an of_device_id
958 * @from: The node to start searching from or NULL, the node
959 * you pass will not be searched, only the next one
960 * will; typically, you pass what the previous call
961 * returned. of_node_put() will be called on it
962 * @matches: array of of device match structures to search in
963 * @match Updated to point at the matches entry which matched
965 * Returns a node pointer with refcount incremented, use
966 * of_node_put() on it when done.
968 struct device_node *of_find_matching_node_and_match(struct device_node *from,
969 const struct of_device_id *matches,
970 const struct of_device_id **match)
972 struct device_node *np;
973 const struct of_device_id *m;
979 raw_spin_lock_irqsave(&devtree_lock, flags);
980 for_each_of_allnodes_from(from, np) {
981 m = __of_match_node(matches, np);
982 if (m && of_node_get(np)) {
989 raw_spin_unlock_irqrestore(&devtree_lock, flags);
992 EXPORT_SYMBOL(of_find_matching_node_and_match);
995 * of_modalias_node - Lookup appropriate modalias for a device node
996 * @node: pointer to a device tree node
997 * @modalias: Pointer to buffer that modalias value will be copied into
998 * @len: Length of modalias value
1000 * Based on the value of the compatible property, this routine will attempt
1001 * to choose an appropriate modalias value for a particular device tree node.
1002 * It does this by stripping the manufacturer prefix (as delimited by a ',')
1003 * from the first entry in the compatible list property.
1005 * This routine returns 0 on success, <0 on failure.
1007 int of_modalias_node(struct device_node *node, char *modalias, int len)
1009 const char *compatible, *p;
1012 compatible = of_get_property(node, "compatible", &cplen);
1013 if (!compatible || strlen(compatible) > cplen)
1015 p = strchr(compatible, ',');
1016 strlcpy(modalias, p ? p + 1 : compatible, len);
1019 EXPORT_SYMBOL_GPL(of_modalias_node);
1022 * of_find_node_by_phandle - Find a node given a phandle
1023 * @handle: phandle of the node to find
1025 * Returns a node pointer with refcount incremented, use
1026 * of_node_put() on it when done.
1028 struct device_node *of_find_node_by_phandle(phandle handle)
1030 struct device_node *np;
1031 unsigned long flags;
1036 raw_spin_lock_irqsave(&devtree_lock, flags);
1037 for_each_of_allnodes(np)
1038 if (np->phandle == handle)
1041 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1044 EXPORT_SYMBOL(of_find_node_by_phandle);
1047 * of_property_count_elems_of_size - Count the number of elements in a property
1049 * @np: device node from which the property value is to be read.
1050 * @propname: name of the property to be searched.
1051 * @elem_size: size of the individual element
1053 * Search for a property in a device node and count the number of elements of
1054 * size elem_size in it. Returns number of elements on sucess, -EINVAL if the
1055 * property does not exist or its length does not match a multiple of elem_size
1056 * and -ENODATA if the property does not have a value.
1058 int of_property_count_elems_of_size(const struct device_node *np,
1059 const char *propname, int elem_size)
1061 struct property *prop = of_find_property(np, propname, NULL);
1068 if (prop->length % elem_size != 0) {
1069 pr_err("size of %s in node %s is not a multiple of %d\n",
1070 propname, np->full_name, elem_size);
1074 return prop->length / elem_size;
1076 EXPORT_SYMBOL_GPL(of_property_count_elems_of_size);
1079 * of_find_property_value_of_size
1081 * @np: device node from which the property value is to be read.
1082 * @propname: name of the property to be searched.
1083 * @len: requested length of property value
1085 * Search for a property in a device node and valid the requested size.
1086 * Returns the property value on success, -EINVAL if the property does not
1087 * exist, -ENODATA if property does not have a value, and -EOVERFLOW if the
1088 * property data isn't large enough.
1091 static void *of_find_property_value_of_size(const struct device_node *np,
1092 const char *propname, u32 len)
1094 struct property *prop = of_find_property(np, propname, NULL);
1097 return ERR_PTR(-EINVAL);
1099 return ERR_PTR(-ENODATA);
1100 if (len > prop->length)
1101 return ERR_PTR(-EOVERFLOW);
1107 * of_property_read_u32_index - Find and read a u32 from a multi-value property.
1109 * @np: device node from which the property value is to be read.
1110 * @propname: name of the property to be searched.
1111 * @index: index of the u32 in the list of values
1112 * @out_value: pointer to return value, modified only if no error.
1114 * Search for a property in a device node and read nth 32-bit value from
1115 * it. Returns 0 on success, -EINVAL if the property does not exist,
1116 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1117 * property data isn't large enough.
1119 * The out_value is modified only if a valid u32 value can be decoded.
1121 int of_property_read_u32_index(const struct device_node *np,
1122 const char *propname,
1123 u32 index, u32 *out_value)
1125 const u32 *val = of_find_property_value_of_size(np, propname,
1126 ((index + 1) * sizeof(*out_value)));
1129 return PTR_ERR(val);
1131 *out_value = be32_to_cpup(((__be32 *)val) + index);
1134 EXPORT_SYMBOL_GPL(of_property_read_u32_index);
1137 * of_property_read_u8_array - Find and read an array of u8 from a property.
1139 * @np: device node from which the property value is to be read.
1140 * @propname: name of the property to be searched.
1141 * @out_values: pointer to return value, modified only if return value is 0.
1142 * @sz: number of array elements to read
1144 * Search for a property in a device node and read 8-bit value(s) from
1145 * it. Returns 0 on success, -EINVAL if the property does not exist,
1146 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1147 * property data isn't large enough.
1149 * dts entry of array should be like:
1150 * property = /bits/ 8 <0x50 0x60 0x70>;
1152 * The out_values is modified only if a valid u8 value can be decoded.
1154 int of_property_read_u8_array(const struct device_node *np,
1155 const char *propname, u8 *out_values, size_t sz)
1157 const u8 *val = of_find_property_value_of_size(np, propname,
1158 (sz * sizeof(*out_values)));
1161 return PTR_ERR(val);
1164 *out_values++ = *val++;
1167 EXPORT_SYMBOL_GPL(of_property_read_u8_array);
1170 * of_property_read_u16_array - Find and read an array of u16 from a property.
1172 * @np: device node from which the property value is to be read.
1173 * @propname: name of the property to be searched.
1174 * @out_values: pointer to return value, modified only if return value is 0.
1175 * @sz: number of array elements to read
1177 * Search for a property in a device node and read 16-bit value(s) from
1178 * it. Returns 0 on success, -EINVAL if the property does not exist,
1179 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1180 * property data isn't large enough.
1182 * dts entry of array should be like:
1183 * property = /bits/ 16 <0x5000 0x6000 0x7000>;
1185 * The out_values is modified only if a valid u16 value can be decoded.
1187 int of_property_read_u16_array(const struct device_node *np,
1188 const char *propname, u16 *out_values, size_t sz)
1190 const __be16 *val = of_find_property_value_of_size(np, propname,
1191 (sz * sizeof(*out_values)));
1194 return PTR_ERR(val);
1197 *out_values++ = be16_to_cpup(val++);
1200 EXPORT_SYMBOL_GPL(of_property_read_u16_array);
1203 * of_property_read_u32_array - Find and read an array of 32 bit integers
1206 * @np: device node from which the property value is to be read.
1207 * @propname: name of the property to be searched.
1208 * @out_values: pointer to return value, modified only if return value is 0.
1209 * @sz: number of array elements to read
1211 * Search for a property in a device node and read 32-bit value(s) from
1212 * it. Returns 0 on success, -EINVAL if the property does not exist,
1213 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1214 * property data isn't large enough.
1216 * The out_values is modified only if a valid u32 value can be decoded.
1218 int of_property_read_u32_array(const struct device_node *np,
1219 const char *propname, u32 *out_values,
1222 const __be32 *val = of_find_property_value_of_size(np, propname,
1223 (sz * sizeof(*out_values)));
1226 return PTR_ERR(val);
1229 *out_values++ = be32_to_cpup(val++);
1232 EXPORT_SYMBOL_GPL(of_property_read_u32_array);
1235 * of_property_read_u64 - Find and read a 64 bit integer from a property
1236 * @np: device node from which the property value is to be read.
1237 * @propname: name of the property to be searched.
1238 * @out_value: pointer to return value, modified only if return value is 0.
1240 * Search for a property in a device node and read a 64-bit value from
1241 * it. Returns 0 on success, -EINVAL if the property does not exist,
1242 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1243 * property data isn't large enough.
1245 * The out_value is modified only if a valid u64 value can be decoded.
1247 int of_property_read_u64(const struct device_node *np, const char *propname,
1250 const __be32 *val = of_find_property_value_of_size(np, propname,
1251 sizeof(*out_value));
1254 return PTR_ERR(val);
1256 *out_value = of_read_number(val, 2);
1259 EXPORT_SYMBOL_GPL(of_property_read_u64);
1262 * of_property_read_string - Find and read a string from a property
1263 * @np: device node from which the property value is to be read.
1264 * @propname: name of the property to be searched.
1265 * @out_string: pointer to null terminated return string, modified only if
1266 * return value is 0.
1268 * Search for a property in a device tree node and retrieve a null
1269 * terminated string value (pointer to data, not a copy). Returns 0 on
1270 * success, -EINVAL if the property does not exist, -ENODATA if property
1271 * does not have a value, and -EILSEQ if the string is not null-terminated
1272 * within the length of the property data.
1274 * The out_string pointer is modified only if a valid string can be decoded.
1276 int of_property_read_string(struct device_node *np, const char *propname,
1277 const char **out_string)
1279 struct property *prop = of_find_property(np, propname, NULL);
1284 if (strnlen(prop->value, prop->length) >= prop->length)
1286 *out_string = prop->value;
1289 EXPORT_SYMBOL_GPL(of_property_read_string);
1292 * of_property_match_string() - Find string in a list and return index
1293 * @np: pointer to node containing string list property
1294 * @propname: string list property name
1295 * @string: pointer to string to search for in string list
1297 * This function searches a string list property and returns the index
1298 * of a specific string value.
1300 int of_property_match_string(struct device_node *np, const char *propname,
1303 struct property *prop = of_find_property(np, propname, NULL);
1306 const char *p, *end;
1314 end = p + prop->length;
1316 for (i = 0; p < end; i++, p += l) {
1317 l = strnlen(p, end - p) + 1;
1320 pr_debug("comparing %s with %s\n", string, p);
1321 if (strcmp(string, p) == 0)
1322 return i; /* Found it; return index */
1326 EXPORT_SYMBOL_GPL(of_property_match_string);
1329 * of_property_read_string_util() - Utility helper for parsing string properties
1330 * @np: device node from which the property value is to be read.
1331 * @propname: name of the property to be searched.
1332 * @out_strs: output array of string pointers.
1333 * @sz: number of array elements to read.
1334 * @skip: Number of strings to skip over at beginning of list.
1336 * Don't call this function directly. It is a utility helper for the
1337 * of_property_read_string*() family of functions.
1339 int of_property_read_string_helper(struct device_node *np, const char *propname,
1340 const char **out_strs, size_t sz, int skip)
1342 struct property *prop = of_find_property(np, propname, NULL);
1344 const char *p, *end;
1351 end = p + prop->length;
1353 for (i = 0; p < end && (!out_strs || i < skip + sz); i++, p += l) {
1354 l = strnlen(p, end - p) + 1;
1357 if (out_strs && i >= skip)
1361 return i <= 0 ? -ENODATA : i;
1363 EXPORT_SYMBOL_GPL(of_property_read_string_helper);
1365 void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
1368 printk("%s %s", msg, of_node_full_name(args->np));
1369 for (i = 0; i < args->args_count; i++)
1370 printk(i ? ",%08x" : ":%08x", args->args[i]);
1374 static int __of_parse_phandle_with_args(const struct device_node *np,
1375 const char *list_name,
1376 const char *cells_name,
1377 int cell_count, int index,
1378 struct of_phandle_args *out_args)
1380 const __be32 *list, *list_end;
1381 int rc = 0, size, cur_index = 0;
1383 struct device_node *node = NULL;
1386 /* Retrieve the phandle list property */
1387 list = of_get_property(np, list_name, &size);
1390 list_end = list + size / sizeof(*list);
1392 /* Loop over the phandles until all the requested entry is found */
1393 while (list < list_end) {
1398 * If phandle is 0, then it is an empty entry with no
1399 * arguments. Skip forward to the next entry.
1401 phandle = be32_to_cpup(list++);
1404 * Find the provider node and parse the #*-cells
1405 * property to determine the argument length.
1407 * This is not needed if the cell count is hard-coded
1408 * (i.e. cells_name not set, but cell_count is set),
1409 * except when we're going to return the found node
1412 if (cells_name || cur_index == index) {
1413 node = of_find_node_by_phandle(phandle);
1415 pr_err("%s: could not find phandle\n",
1422 if (of_property_read_u32(node, cells_name,
1424 pr_err("%s: could not get %s for %s\n",
1425 np->full_name, cells_name,
1434 * Make sure that the arguments actually fit in the
1435 * remaining property data length
1437 if (list + count > list_end) {
1438 pr_err("%s: arguments longer than property\n",
1445 * All of the error cases above bail out of the loop, so at
1446 * this point, the parsing is successful. If the requested
1447 * index matches, then fill the out_args structure and return,
1448 * or return -ENOENT for an empty entry.
1451 if (cur_index == index) {
1457 if (WARN_ON(count > MAX_PHANDLE_ARGS))
1458 count = MAX_PHANDLE_ARGS;
1459 out_args->np = node;
1460 out_args->args_count = count;
1461 for (i = 0; i < count; i++)
1462 out_args->args[i] = be32_to_cpup(list++);
1467 /* Found it! return success */
1478 * Unlock node before returning result; will be one of:
1479 * -ENOENT : index is for empty phandle
1480 * -EINVAL : parsing error on data
1481 * [1..n] : Number of phandle (count mode; when index = -1)
1483 rc = index < 0 ? cur_index : -ENOENT;
1491 * of_parse_phandle - Resolve a phandle property to a device_node pointer
1492 * @np: Pointer to device node holding phandle property
1493 * @phandle_name: Name of property holding a phandle value
1494 * @index: For properties holding a table of phandles, this is the index into
1497 * Returns the device_node pointer with refcount incremented. Use
1498 * of_node_put() on it when done.
1500 struct device_node *of_parse_phandle(const struct device_node *np,
1501 const char *phandle_name, int index)
1503 struct of_phandle_args args;
1508 if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0,
1514 EXPORT_SYMBOL(of_parse_phandle);
1517 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
1518 * @np: pointer to a device tree node containing a list
1519 * @list_name: property name that contains a list
1520 * @cells_name: property name that specifies phandles' arguments count
1521 * @index: index of a phandle to parse out
1522 * @out_args: optional pointer to output arguments structure (will be filled)
1524 * This function is useful to parse lists of phandles and their arguments.
1525 * Returns 0 on success and fills out_args, on error returns appropriate
1528 * Caller is responsible to call of_node_put() on the returned out_args->np
1534 * #list-cells = <2>;
1538 * #list-cells = <1>;
1542 * list = <&phandle1 1 2 &phandle2 3>;
1545 * To get a device_node of the `node2' node you may call this:
1546 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
1548 int of_parse_phandle_with_args(const struct device_node *np, const char *list_name,
1549 const char *cells_name, int index,
1550 struct of_phandle_args *out_args)
1554 return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
1557 EXPORT_SYMBOL(of_parse_phandle_with_args);
1560 * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
1561 * @np: pointer to a device tree node containing a list
1562 * @list_name: property name that contains a list
1563 * @cell_count: number of argument cells following the phandle
1564 * @index: index of a phandle to parse out
1565 * @out_args: optional pointer to output arguments structure (will be filled)
1567 * This function is useful to parse lists of phandles and their arguments.
1568 * Returns 0 on success and fills out_args, on error returns appropriate
1571 * Caller is responsible to call of_node_put() on the returned out_args->np
1583 * list = <&phandle1 0 2 &phandle2 2 3>;
1586 * To get a device_node of the `node2' node you may call this:
1587 * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
1589 int of_parse_phandle_with_fixed_args(const struct device_node *np,
1590 const char *list_name, int cell_count,
1591 int index, struct of_phandle_args *out_args)
1595 return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
1598 EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);
1601 * of_count_phandle_with_args() - Find the number of phandles references in a property
1602 * @np: pointer to a device tree node containing a list
1603 * @list_name: property name that contains a list
1604 * @cells_name: property name that specifies phandles' arguments count
1606 * Returns the number of phandle + argument tuples within a property. It
1607 * is a typical pattern to encode a list of phandle and variable
1608 * arguments into a single property. The number of arguments is encoded
1609 * by a property in the phandle-target node. For example, a gpios
1610 * property would contain a list of GPIO specifies consisting of a
1611 * phandle and 1 or more arguments. The number of arguments are
1612 * determined by the #gpio-cells property in the node pointed to by the
1615 int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1616 const char *cells_name)
1618 return __of_parse_phandle_with_args(np, list_name, cells_name, 0, -1,
1621 EXPORT_SYMBOL(of_count_phandle_with_args);
1624 * __of_add_property - Add a property to a node without lock operations
1626 int __of_add_property(struct device_node *np, struct property *prop)
1628 struct property **next;
1631 next = &np->properties;
1633 if (strcmp(prop->name, (*next)->name) == 0)
1634 /* duplicate ! don't insert it */
1637 next = &(*next)->next;
1645 * of_add_property - Add a property to a node
1647 int of_add_property(struct device_node *np, struct property *prop)
1649 unsigned long flags;
1652 mutex_lock(&of_mutex);
1654 raw_spin_lock_irqsave(&devtree_lock, flags);
1655 rc = __of_add_property(np, prop);
1656 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1659 __of_add_property_sysfs(np, prop);
1661 mutex_unlock(&of_mutex);
1664 of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
1669 int __of_remove_property(struct device_node *np, struct property *prop)
1671 struct property **next;
1673 for (next = &np->properties; *next; next = &(*next)->next) {
1680 /* found the node */
1682 prop->next = np->deadprops;
1683 np->deadprops = prop;
1688 void __of_remove_property_sysfs(struct device_node *np, struct property *prop)
1690 if (!IS_ENABLED(CONFIG_SYSFS))
1693 /* at early boot, bail here and defer setup to of_init() */
1694 if (of_kset && of_node_is_attached(np))
1695 sysfs_remove_bin_file(&np->kobj, &prop->attr);
1699 * of_remove_property - Remove a property from a node.
1701 * Note that we don't actually remove it, since we have given out
1702 * who-knows-how-many pointers to the data using get-property.
1703 * Instead we just move the property to the "dead properties"
1704 * list, so it won't be found any more.
1706 int of_remove_property(struct device_node *np, struct property *prop)
1708 unsigned long flags;
1711 mutex_lock(&of_mutex);
1713 raw_spin_lock_irqsave(&devtree_lock, flags);
1714 rc = __of_remove_property(np, prop);
1715 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1718 __of_remove_property_sysfs(np, prop);
1720 mutex_unlock(&of_mutex);
1723 of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
1728 int __of_update_property(struct device_node *np, struct property *newprop,
1729 struct property **oldpropp)
1731 struct property **next, *oldprop;
1733 for (next = &np->properties; *next; next = &(*next)->next) {
1734 if (of_prop_cmp((*next)->name, newprop->name) == 0)
1737 *oldpropp = oldprop = *next;
1740 /* replace the node */
1741 newprop->next = oldprop->next;
1743 oldprop->next = np->deadprops;
1744 np->deadprops = oldprop;
1747 newprop->next = NULL;
1754 void __of_update_property_sysfs(struct device_node *np, struct property *newprop,
1755 struct property *oldprop)
1757 if (!IS_ENABLED(CONFIG_SYSFS))
1760 /* At early boot, bail out and defer setup to of_init() */
1765 sysfs_remove_bin_file(&np->kobj, &oldprop->attr);
1766 __of_add_property_sysfs(np, newprop);
1770 * of_update_property - Update a property in a node, if the property does
1771 * not exist, add it.
1773 * Note that we don't actually remove it, since we have given out
1774 * who-knows-how-many pointers to the data using get-property.
1775 * Instead we just move the property to the "dead properties" list,
1776 * and add the new property to the property list
1778 int of_update_property(struct device_node *np, struct property *newprop)
1780 struct property *oldprop;
1781 unsigned long flags;
1787 mutex_lock(&of_mutex);
1789 raw_spin_lock_irqsave(&devtree_lock, flags);
1790 rc = __of_update_property(np, newprop, &oldprop);
1791 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1794 __of_update_property_sysfs(np, newprop, oldprop);
1796 mutex_unlock(&of_mutex);
1799 of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
1804 static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1805 int id, const char *stem, int stem_len)
1809 strncpy(ap->stem, stem, stem_len);
1810 ap->stem[stem_len] = 0;
1811 list_add_tail(&ap->link, &aliases_lookup);
1812 pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
1813 ap->alias, ap->stem, ap->id, of_node_full_name(np));
1817 * of_alias_scan - Scan all properties of 'aliases' node
1819 * The function scans all the properties of 'aliases' node and populate
1820 * the the global lookup table with the properties. It returns the
1821 * number of alias_prop found, or error code in error case.
1823 * @dt_alloc: An allocator that provides a virtual address to memory
1824 * for the resulting tree
1826 void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1828 struct property *pp;
1830 of_aliases = of_find_node_by_path("/aliases");
1831 of_chosen = of_find_node_by_path("/chosen");
1832 if (of_chosen == NULL)
1833 of_chosen = of_find_node_by_path("/chosen@0");
1836 /* linux,stdout-path and /aliases/stdout are for legacy compatibility */
1837 const char *name = of_get_property(of_chosen, "stdout-path", NULL);
1839 name = of_get_property(of_chosen, "linux,stdout-path", NULL);
1840 if (IS_ENABLED(CONFIG_PPC) && !name)
1841 name = of_get_property(of_aliases, "stdout", NULL);
1843 of_stdout = of_find_node_by_path(name);
1849 for_each_property_of_node(of_aliases, pp) {
1850 const char *start = pp->name;
1851 const char *end = start + strlen(start);
1852 struct device_node *np;
1853 struct alias_prop *ap;
1856 /* Skip those we do not want to proceed */
1857 if (!strcmp(pp->name, "name") ||
1858 !strcmp(pp->name, "phandle") ||
1859 !strcmp(pp->name, "linux,phandle"))
1862 np = of_find_node_by_path(pp->value);
1866 /* walk the alias backwards to extract the id and work out
1867 * the 'stem' string */
1868 while (isdigit(*(end-1)) && end > start)
1872 if (kstrtoint(end, 10, &id) < 0)
1875 /* Allocate an alias_prop with enough space for the stem */
1876 ap = dt_alloc(sizeof(*ap) + len + 1, 4);
1879 memset(ap, 0, sizeof(*ap) + len + 1);
1881 of_alias_add(ap, np, id, start, len);
1886 * of_alias_get_id - Get alias id for the given device_node
1887 * @np: Pointer to the given device_node
1888 * @stem: Alias stem of the given device_node
1890 * The function travels the lookup table to get the alias id for the given
1891 * device_node and alias stem. It returns the alias id if found.
1893 int of_alias_get_id(struct device_node *np, const char *stem)
1895 struct alias_prop *app;
1898 mutex_lock(&of_mutex);
1899 list_for_each_entry(app, &aliases_lookup, link) {
1900 if (strcmp(app->stem, stem) != 0)
1903 if (np == app->np) {
1908 mutex_unlock(&of_mutex);
1912 EXPORT_SYMBOL_GPL(of_alias_get_id);
1914 const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
1917 const void *curv = cur;
1927 curv += sizeof(*cur);
1928 if (curv >= prop->value + prop->length)
1932 *pu = be32_to_cpup(curv);
1935 EXPORT_SYMBOL_GPL(of_prop_next_u32);
1937 const char *of_prop_next_string(struct property *prop, const char *cur)
1939 const void *curv = cur;
1947 curv += strlen(cur) + 1;
1948 if (curv >= prop->value + prop->length)
1953 EXPORT_SYMBOL_GPL(of_prop_next_string);
1956 * of_console_check() - Test and setup console for DT setup
1957 * @dn - Pointer to device node
1958 * @name - Name to use for preferred console without index. ex. "ttyS"
1959 * @index - Index to use for preferred console.
1961 * Check if the given device node matches the stdout-path property in the
1962 * /chosen node. If it does then register it as the preferred console and return
1963 * TRUE. Otherwise return FALSE.
1965 bool of_console_check(struct device_node *dn, char *name, int index)
1967 if (!dn || dn != of_stdout || console_set_on_cmdline)
1969 return !add_preferred_console(name, index, NULL);
1971 EXPORT_SYMBOL_GPL(of_console_check);
1974 * of_find_next_cache_node - Find a node's subsidiary cache
1975 * @np: node of type "cpu" or "cache"
1977 * Returns a node pointer with refcount incremented, use
1978 * of_node_put() on it when done. Caller should hold a reference
1981 struct device_node *of_find_next_cache_node(const struct device_node *np)
1983 struct device_node *child;
1984 const phandle *handle;
1986 handle = of_get_property(np, "l2-cache", NULL);
1988 handle = of_get_property(np, "next-level-cache", NULL);
1991 return of_find_node_by_phandle(be32_to_cpup(handle));
1993 /* OF on pmac has nodes instead of properties named "l2-cache"
1994 * beneath CPU nodes.
1996 if (!strcmp(np->type, "cpu"))
1997 for_each_child_of_node(np, child)
1998 if (!strcmp(child->type, "cache"))
2005 * of_graph_parse_endpoint() - parse common endpoint node properties
2006 * @node: pointer to endpoint device_node
2007 * @endpoint: pointer to the OF endpoint data structure
2009 * The caller should hold a reference to @node.
2011 int of_graph_parse_endpoint(const struct device_node *node,
2012 struct of_endpoint *endpoint)
2014 struct device_node *port_node = of_get_parent(node);
2016 WARN_ONCE(!port_node, "%s(): endpoint %s has no parent node\n",
2017 __func__, node->full_name);
2019 memset(endpoint, 0, sizeof(*endpoint));
2021 endpoint->local_node = node;
2023 * It doesn't matter whether the two calls below succeed.
2024 * If they don't then the default value 0 is used.
2026 of_property_read_u32(port_node, "reg", &endpoint->port);
2027 of_property_read_u32(node, "reg", &endpoint->id);
2029 of_node_put(port_node);
2033 EXPORT_SYMBOL(of_graph_parse_endpoint);
2036 * of_graph_get_next_endpoint() - get next endpoint node
2037 * @parent: pointer to the parent device node
2038 * @prev: previous endpoint node, or NULL to get first
2040 * Return: An 'endpoint' node pointer with refcount incremented. Refcount
2041 * of the passed @prev node is not decremented, the caller have to use
2042 * of_node_put() on it when done.
2044 struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
2045 struct device_node *prev)
2047 struct device_node *endpoint;
2048 struct device_node *port;
2054 * Start by locating the port node. If no previous endpoint is specified
2055 * search for the first port node, otherwise get the previous endpoint
2059 struct device_node *node;
2061 node = of_get_child_by_name(parent, "ports");
2065 port = of_get_child_by_name(parent, "port");
2069 pr_err("%s(): no port node found in %s\n",
2070 __func__, parent->full_name);
2074 port = of_get_parent(prev);
2075 if (WARN_ONCE(!port, "%s(): endpoint %s has no parent node\n",
2076 __func__, prev->full_name))
2080 * Avoid dropping prev node refcount to 0 when getting the next
2088 * Now that we have a port node, get the next endpoint by
2089 * getting the next child. If the previous endpoint is NULL this
2090 * will return the first child.
2092 endpoint = of_get_next_child(port, prev);
2098 /* No more endpoints under this port, try the next one. */
2102 port = of_get_next_child(parent, port);
2105 } while (of_node_cmp(port->name, "port"));
2108 EXPORT_SYMBOL(of_graph_get_next_endpoint);
2111 * of_graph_get_remote_port_parent() - get remote port's parent node
2112 * @node: pointer to a local endpoint device_node
2114 * Return: Remote device node associated with remote endpoint node linked
2115 * to @node. Use of_node_put() on it when done.
2117 struct device_node *of_graph_get_remote_port_parent(
2118 const struct device_node *node)
2120 struct device_node *np;
2123 /* Get remote endpoint node. */
2124 np = of_parse_phandle(node, "remote-endpoint", 0);
2126 /* Walk 3 levels up only if there is 'ports' node. */
2127 for (depth = 3; depth && np; depth--) {
2128 np = of_get_next_parent(np);
2129 if (depth == 2 && of_node_cmp(np->name, "ports"))
2134 EXPORT_SYMBOL(of_graph_get_remote_port_parent);
2137 * of_graph_get_remote_port() - get remote port node
2138 * @node: pointer to a local endpoint device_node
2140 * Return: Remote port node associated with remote endpoint node linked
2141 * to @node. Use of_node_put() on it when done.
2143 struct device_node *of_graph_get_remote_port(const struct device_node *node)
2145 struct device_node *np;
2147 /* Get remote endpoint node. */
2148 np = of_parse_phandle(node, "remote-endpoint", 0);
2151 return of_get_next_parent(np);
2153 EXPORT_SYMBOL(of_graph_get_remote_port);