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/bitmap.h>
20 #include <linux/console.h>
21 #include <linux/ctype.h>
22 #include <linux/cpu.h>
23 #include <linux/module.h>
25 #include <linux/of_device.h>
26 #include <linux/of_graph.h>
27 #include <linux/spinlock.h>
28 #include <linux/slab.h>
29 #include <linux/string.h>
30 #include <linux/proc_fs.h>
32 #include "of_private.h"
34 LIST_HEAD(aliases_lookup);
36 struct device_node *of_root;
37 EXPORT_SYMBOL(of_root);
38 struct device_node *of_chosen;
39 EXPORT_SYMBOL(of_chosen);
40 struct device_node *of_aliases;
41 struct device_node *of_stdout;
42 static const char *of_stdout_options;
47 * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
48 * This mutex must be held whenever modifications are being made to the
49 * device tree. The of_{attach,detach}_node() and
50 * of_{add,remove,update}_property() helpers make sure this happens.
52 DEFINE_MUTEX(of_mutex);
54 /* use when traversing tree through the child, sibling,
55 * or parent members of struct device_node.
57 DEFINE_RAW_SPINLOCK(devtree_lock);
59 bool of_node_name_eq(const struct device_node *np, const char *name)
61 const char *node_name;
67 node_name = kbasename(np->full_name);
68 len = strchrnul(node_name, '@') - node_name;
70 return (strlen(name) == len) && (strncmp(node_name, name, len) == 0);
72 EXPORT_SYMBOL(of_node_name_eq);
74 bool of_node_name_prefix(const struct device_node *np, const char *prefix)
79 return strncmp(kbasename(np->full_name), prefix, strlen(prefix)) == 0;
81 EXPORT_SYMBOL(of_node_name_prefix);
83 static bool __of_node_is_type(const struct device_node *np, const char *type)
85 const char *match = __of_get_property(np, "device_type", NULL);
87 return np && match && type && !strcmp(match, type);
90 int of_bus_n_addr_cells(struct device_node *np)
94 for (; np; np = np->parent)
95 if (!of_property_read_u32(np, "#address-cells", &cells))
98 /* No #address-cells property for the root node */
99 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
102 int of_n_addr_cells(struct device_node *np)
107 return of_bus_n_addr_cells(np);
109 EXPORT_SYMBOL(of_n_addr_cells);
111 int of_bus_n_size_cells(struct device_node *np)
115 for (; np; np = np->parent)
116 if (!of_property_read_u32(np, "#size-cells", &cells))
119 /* No #size-cells property for the root node */
120 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
123 int of_n_size_cells(struct device_node *np)
128 return of_bus_n_size_cells(np);
130 EXPORT_SYMBOL(of_n_size_cells);
133 int __weak of_node_to_nid(struct device_node *np)
139 #define OF_PHANDLE_CACHE_BITS 7
140 #define OF_PHANDLE_CACHE_SZ BIT(OF_PHANDLE_CACHE_BITS)
142 static struct device_node *phandle_cache[OF_PHANDLE_CACHE_SZ];
144 static u32 of_phandle_cache_hash(phandle handle)
146 return hash_32(handle, OF_PHANDLE_CACHE_BITS);
150 * Caller must hold devtree_lock.
152 void __of_phandle_cache_inv_entry(phandle handle)
155 struct device_node *np;
160 handle_hash = of_phandle_cache_hash(handle);
162 np = phandle_cache[handle_hash];
163 if (np && handle == np->phandle)
164 phandle_cache[handle_hash] = NULL;
167 void __init of_core_init(void)
169 struct device_node *np;
172 /* Create the kset, and register existing nodes */
173 mutex_lock(&of_mutex);
174 of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
176 mutex_unlock(&of_mutex);
177 pr_err("failed to register existing nodes\n");
180 for_each_of_allnodes(np) {
181 __of_attach_node_sysfs(np);
182 if (np->phandle && !phandle_cache[of_phandle_cache_hash(np->phandle)])
183 phandle_cache[of_phandle_cache_hash(np->phandle)] = np;
185 mutex_unlock(&of_mutex);
187 /* Symlink in /proc as required by userspace ABI */
189 proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
192 static struct property *__of_find_property(const struct device_node *np,
193 const char *name, int *lenp)
200 for (pp = np->properties; pp; pp = pp->next) {
201 if (of_prop_cmp(pp->name, name) == 0) {
211 struct property *of_find_property(const struct device_node *np,
218 raw_spin_lock_irqsave(&devtree_lock, flags);
219 pp = __of_find_property(np, name, lenp);
220 raw_spin_unlock_irqrestore(&devtree_lock, flags);
224 EXPORT_SYMBOL(of_find_property);
226 struct device_node *__of_find_all_nodes(struct device_node *prev)
228 struct device_node *np;
231 } else if (prev->child) {
234 /* Walk back up looking for a sibling, or the end of the structure */
236 while (np->parent && !np->sibling)
238 np = np->sibling; /* Might be null at the end of the tree */
244 * of_find_all_nodes - Get next node in global list
245 * @prev: Previous node or NULL to start iteration
246 * of_node_put() will be called on it
248 * Return: A node pointer with refcount incremented, use
249 * of_node_put() on it when done.
251 struct device_node *of_find_all_nodes(struct device_node *prev)
253 struct device_node *np;
256 raw_spin_lock_irqsave(&devtree_lock, flags);
257 np = __of_find_all_nodes(prev);
260 raw_spin_unlock_irqrestore(&devtree_lock, flags);
263 EXPORT_SYMBOL(of_find_all_nodes);
266 * Find a property with a given name for a given node
267 * and return the value.
269 const void *__of_get_property(const struct device_node *np,
270 const char *name, int *lenp)
272 struct property *pp = __of_find_property(np, name, lenp);
274 return pp ? pp->value : NULL;
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, const char *name,
284 struct property *pp = of_find_property(np, name, lenp);
286 return pp ? pp->value : NULL;
288 EXPORT_SYMBOL(of_get_property);
291 * arch_match_cpu_phys_id - Match the given logical CPU and physical id
293 * @cpu: logical cpu index of a core/thread
294 * @phys_id: physical identifier of a core/thread
296 * CPU logical to physical index mapping is architecture specific.
297 * However this __weak function provides a default match of physical
298 * id to logical cpu index. phys_id provided here is usually values read
299 * from the device tree which must match the hardware internal registers.
301 * Returns true if the physical identifier and the logical cpu index
302 * correspond to the same core/thread, false otherwise.
304 bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
306 return (u32)phys_id == cpu;
310 * Checks if the given "prop_name" property holds the physical id of the
311 * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
312 * NULL, local thread number within the core is returned in it.
314 static bool __of_find_n_match_cpu_property(struct device_node *cpun,
315 const char *prop_name, int cpu, unsigned int *thread)
318 int ac, prop_len, tid;
321 ac = of_n_addr_cells(cpun);
322 cell = of_get_property(cpun, prop_name, &prop_len);
323 if (!cell && !ac && arch_match_cpu_phys_id(cpu, 0))
327 prop_len /= sizeof(*cell) * ac;
328 for (tid = 0; tid < prop_len; tid++) {
329 hwid = of_read_number(cell, ac);
330 if (arch_match_cpu_phys_id(cpu, hwid)) {
341 * arch_find_n_match_cpu_physical_id - See if the given device node is
342 * for the cpu corresponding to logical cpu 'cpu'. Return true if so,
343 * else false. If 'thread' is non-NULL, the local thread number within the
344 * core is returned in it.
346 bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
347 int cpu, unsigned int *thread)
349 /* Check for non-standard "ibm,ppc-interrupt-server#s" property
350 * for thread ids on PowerPC. If it doesn't exist fallback to
351 * standard "reg" property.
353 if (IS_ENABLED(CONFIG_PPC) &&
354 __of_find_n_match_cpu_property(cpun,
355 "ibm,ppc-interrupt-server#s",
359 return __of_find_n_match_cpu_property(cpun, "reg", cpu, thread);
363 * of_get_cpu_node - Get device node associated with the given logical CPU
365 * @cpu: CPU number(logical index) for which device node is required
366 * @thread: if not NULL, local thread number within the physical core is
369 * The main purpose of this function is to retrieve the device node for the
370 * given logical CPU index. It should be used to initialize the of_node in
371 * cpu device. Once of_node in cpu device is populated, all the further
372 * references can use that instead.
374 * CPU logical to physical index mapping is architecture specific and is built
375 * before booting secondary cores. This function uses arch_match_cpu_phys_id
376 * which can be overridden by architecture specific implementation.
378 * Return: A node pointer for the logical cpu with refcount incremented, use
379 * of_node_put() on it when done. Returns NULL if not found.
381 struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
383 struct device_node *cpun;
385 for_each_of_cpu_node(cpun) {
386 if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
391 EXPORT_SYMBOL(of_get_cpu_node);
394 * of_cpu_node_to_id: Get the logical CPU number for a given device_node
396 * @cpu_node: Pointer to the device_node for CPU.
398 * Return: The logical CPU number of the given CPU device_node or -ENODEV if the
401 int of_cpu_node_to_id(struct device_node *cpu_node)
405 struct device_node *np;
407 for_each_possible_cpu(cpu) {
408 np = of_cpu_device_node_get(cpu);
409 found = (cpu_node == np);
417 EXPORT_SYMBOL(of_cpu_node_to_id);
420 * of_get_cpu_state_node - Get CPU's idle state node at the given index
422 * @cpu_node: The device node for the CPU
423 * @index: The index in the list of the idle states
425 * Two generic methods can be used to describe a CPU's idle states, either via
426 * a flattened description through the "cpu-idle-states" binding or via the
427 * hierarchical layout, using the "power-domains" and the "domain-idle-states"
428 * bindings. This function check for both and returns the idle state node for
429 * the requested index.
431 * Return: An idle state node if found at @index. The refcount is incremented
432 * for it, so call of_node_put() on it when done. Returns NULL if not found.
434 struct device_node *of_get_cpu_state_node(struct device_node *cpu_node,
437 struct of_phandle_args args;
440 err = of_parse_phandle_with_args(cpu_node, "power-domains",
441 "#power-domain-cells", 0, &args);
443 struct device_node *state_node =
444 of_parse_phandle(args.np, "domain-idle-states", index);
446 of_node_put(args.np);
451 return of_parse_phandle(cpu_node, "cpu-idle-states", index);
453 EXPORT_SYMBOL(of_get_cpu_state_node);
456 * __of_device_is_compatible() - Check if the node matches given constraints
457 * @device: pointer to node
458 * @compat: required compatible string, NULL or "" for any match
459 * @type: required device_type value, NULL or "" for any match
460 * @name: required node name, NULL or "" for any match
462 * Checks if the given @compat, @type and @name strings match the
463 * properties of the given @device. A constraints can be skipped by
464 * passing NULL or an empty string as the constraint.
466 * Returns 0 for no match, and a positive integer on match. The return
467 * value is a relative score with larger values indicating better
468 * matches. The score is weighted for the most specific compatible value
469 * to get the highest score. Matching type is next, followed by matching
470 * name. Practically speaking, this results in the following priority
473 * 1. specific compatible && type && name
474 * 2. specific compatible && type
475 * 3. specific compatible && name
476 * 4. specific compatible
477 * 5. general compatible && type && name
478 * 6. general compatible && type
479 * 7. general compatible && name
480 * 8. general compatible
485 static int __of_device_is_compatible(const struct device_node *device,
486 const char *compat, const char *type, const char *name)
488 struct property *prop;
490 int index = 0, score = 0;
492 /* Compatible match has highest priority */
493 if (compat && compat[0]) {
494 prop = __of_find_property(device, "compatible", NULL);
495 for (cp = of_prop_next_string(prop, NULL); cp;
496 cp = of_prop_next_string(prop, cp), index++) {
497 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
498 score = INT_MAX/2 - (index << 2);
506 /* Matching type is better than matching name */
507 if (type && type[0]) {
508 if (!__of_node_is_type(device, type))
513 /* Matching name is a bit better than not */
514 if (name && name[0]) {
515 if (!of_node_name_eq(device, name))
523 /** Checks if the given "compat" string matches one of the strings in
524 * the device's "compatible" property
526 int of_device_is_compatible(const struct device_node *device,
532 raw_spin_lock_irqsave(&devtree_lock, flags);
533 res = __of_device_is_compatible(device, compat, NULL, NULL);
534 raw_spin_unlock_irqrestore(&devtree_lock, flags);
537 EXPORT_SYMBOL(of_device_is_compatible);
539 /** Checks if the device is compatible with any of the entries in
540 * a NULL terminated array of strings. Returns the best match
543 int of_device_compatible_match(struct device_node *device,
544 const char *const *compat)
546 unsigned int tmp, score = 0;
552 tmp = of_device_is_compatible(device, *compat);
562 * of_machine_is_compatible - Test root of device tree for a given compatible value
563 * @compat: compatible string to look for in root node's compatible property.
565 * Return: A positive integer if the root node has the given value in its
566 * compatible property.
568 int of_machine_is_compatible(const char *compat)
570 struct device_node *root;
573 root = of_find_node_by_path("/");
575 rc = of_device_is_compatible(root, compat);
580 EXPORT_SYMBOL(of_machine_is_compatible);
583 * __of_device_is_available - check if a device is available for use
585 * @device: Node to check for availability, with locks already held
587 * Return: True if the status property is absent or set to "okay" or "ok",
590 static bool __of_device_is_available(const struct device_node *device)
598 status = __of_get_property(device, "status", &statlen);
603 if (!strcmp(status, "okay") || !strcmp(status, "ok"))
611 * of_device_is_available - check if a device is available for use
613 * @device: Node to check for availability
615 * Return: True if the status property is absent or set to "okay" or "ok",
618 bool of_device_is_available(const struct device_node *device)
623 raw_spin_lock_irqsave(&devtree_lock, flags);
624 res = __of_device_is_available(device);
625 raw_spin_unlock_irqrestore(&devtree_lock, flags);
629 EXPORT_SYMBOL(of_device_is_available);
632 * of_device_is_big_endian - check if a device has BE registers
634 * @device: Node to check for endianness
636 * Return: True if the device has a "big-endian" property, or if the kernel
637 * was compiled for BE *and* the device has a "native-endian" property.
638 * Returns false otherwise.
640 * Callers would nominally use ioread32be/iowrite32be if
641 * of_device_is_big_endian() == true, or readl/writel otherwise.
643 bool of_device_is_big_endian(const struct device_node *device)
645 if (of_property_read_bool(device, "big-endian"))
647 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
648 of_property_read_bool(device, "native-endian"))
652 EXPORT_SYMBOL(of_device_is_big_endian);
655 * of_get_parent - Get a node's parent if any
656 * @node: Node to get parent
658 * Return: A node pointer with refcount incremented, use
659 * of_node_put() on it when done.
661 struct device_node *of_get_parent(const struct device_node *node)
663 struct device_node *np;
669 raw_spin_lock_irqsave(&devtree_lock, flags);
670 np = of_node_get(node->parent);
671 raw_spin_unlock_irqrestore(&devtree_lock, flags);
674 EXPORT_SYMBOL(of_get_parent);
677 * of_get_next_parent - Iterate to a node's parent
678 * @node: Node to get parent of
680 * This is like of_get_parent() except that it drops the
681 * refcount on the passed node, making it suitable for iterating
682 * through a node's parents.
684 * Return: A node pointer with refcount incremented, use
685 * of_node_put() on it when done.
687 struct device_node *of_get_next_parent(struct device_node *node)
689 struct device_node *parent;
695 raw_spin_lock_irqsave(&devtree_lock, flags);
696 parent = of_node_get(node->parent);
698 raw_spin_unlock_irqrestore(&devtree_lock, flags);
701 EXPORT_SYMBOL(of_get_next_parent);
703 static struct device_node *__of_get_next_child(const struct device_node *node,
704 struct device_node *prev)
706 struct device_node *next;
711 next = prev ? prev->sibling : node->child;
716 #define __for_each_child_of_node(parent, child) \
717 for (child = __of_get_next_child(parent, NULL); child != NULL; \
718 child = __of_get_next_child(parent, child))
721 * of_get_next_child - Iterate a node childs
723 * @prev: previous child of the parent node, or NULL to get first
725 * Return: A node pointer with refcount incremented, use of_node_put() on
726 * it when done. Returns NULL when prev is the last child. Decrements the
729 struct device_node *of_get_next_child(const struct device_node *node,
730 struct device_node *prev)
732 struct device_node *next;
735 raw_spin_lock_irqsave(&devtree_lock, flags);
736 next = __of_get_next_child(node, prev);
737 raw_spin_unlock_irqrestore(&devtree_lock, flags);
740 EXPORT_SYMBOL(of_get_next_child);
743 * of_get_next_available_child - Find the next available child node
745 * @prev: previous child of the parent node, or NULL to get first
747 * This function is like of_get_next_child(), except that it
748 * automatically skips any disabled nodes (i.e. status = "disabled").
750 struct device_node *of_get_next_available_child(const struct device_node *node,
751 struct device_node *prev)
753 struct device_node *next;
759 raw_spin_lock_irqsave(&devtree_lock, flags);
760 next = prev ? prev->sibling : node->child;
761 for (; next; next = next->sibling) {
762 if (!__of_device_is_available(next))
764 if (of_node_get(next))
768 raw_spin_unlock_irqrestore(&devtree_lock, flags);
771 EXPORT_SYMBOL(of_get_next_available_child);
774 * of_get_next_cpu_node - Iterate on cpu nodes
775 * @prev: previous child of the /cpus node, or NULL to get first
777 * Return: A cpu node pointer with refcount incremented, use of_node_put()
778 * on it when done. Returns NULL when prev is the last child. Decrements
779 * the refcount of prev.
781 struct device_node *of_get_next_cpu_node(struct device_node *prev)
783 struct device_node *next = NULL;
785 struct device_node *node;
788 node = of_find_node_by_path("/cpus");
790 raw_spin_lock_irqsave(&devtree_lock, flags);
792 next = prev->sibling;
797 for (; next; next = next->sibling) {
798 if (!(of_node_name_eq(next, "cpu") ||
799 __of_node_is_type(next, "cpu")))
801 if (of_node_get(next))
805 raw_spin_unlock_irqrestore(&devtree_lock, flags);
808 EXPORT_SYMBOL(of_get_next_cpu_node);
811 * of_get_compatible_child - Find compatible child node
812 * @parent: parent node
813 * @compatible: compatible string
815 * Lookup child node whose compatible property contains the given compatible
818 * Return: a node pointer with refcount incremented, use of_node_put() on it
819 * when done; or NULL if not found.
821 struct device_node *of_get_compatible_child(const struct device_node *parent,
822 const char *compatible)
824 struct device_node *child;
826 for_each_child_of_node(parent, child) {
827 if (of_device_is_compatible(child, compatible))
833 EXPORT_SYMBOL(of_get_compatible_child);
836 * of_get_child_by_name - Find the child node by name for a given parent
838 * @name: child name to look for.
840 * This function looks for child node for given matching name
842 * Return: A node pointer if found, with refcount incremented, use
843 * of_node_put() on it when done.
844 * Returns NULL if node is not found.
846 struct device_node *of_get_child_by_name(const struct device_node *node,
849 struct device_node *child;
851 for_each_child_of_node(node, child)
852 if (of_node_name_eq(child, name))
856 EXPORT_SYMBOL(of_get_child_by_name);
858 struct device_node *__of_find_node_by_path(struct device_node *parent,
861 struct device_node *child;
864 len = strcspn(path, "/:");
868 __for_each_child_of_node(parent, child) {
869 const char *name = kbasename(child->full_name);
870 if (strncmp(path, name, len) == 0 && (strlen(name) == len))
876 struct device_node *__of_find_node_by_full_path(struct device_node *node,
879 const char *separator = strchr(path, ':');
881 while (node && *path == '/') {
882 struct device_node *tmp = node;
884 path++; /* Increment past '/' delimiter */
885 node = __of_find_node_by_path(node, path);
887 path = strchrnul(path, '/');
888 if (separator && separator < path)
895 * of_find_node_opts_by_path - Find a node matching a full OF path
896 * @path: Either the full path to match, or if the path does not
897 * start with '/', the name of a property of the /aliases
898 * node (an alias). In the case of an alias, the node
899 * matching the alias' value will be returned.
900 * @opts: Address of a pointer into which to store the start of
901 * an options string appended to the end of the path with
905 * * /foo/bar Full path
907 * * foo/bar Valid alias + relative path
909 * Return: A node pointer with refcount incremented, use
910 * of_node_put() on it when done.
912 struct device_node *of_find_node_opts_by_path(const char *path, const char **opts)
914 struct device_node *np = NULL;
917 const char *separator = strchr(path, ':');
920 *opts = separator ? separator + 1 : NULL;
922 if (strcmp(path, "/") == 0)
923 return of_node_get(of_root);
925 /* The path could begin with an alias */
928 const char *p = separator;
931 p = strchrnul(path, '/');
934 /* of_aliases must not be NULL */
938 for_each_property_of_node(of_aliases, pp) {
939 if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
940 np = of_find_node_by_path(pp->value);
949 /* Step down the tree matching path components */
950 raw_spin_lock_irqsave(&devtree_lock, flags);
952 np = of_node_get(of_root);
953 np = __of_find_node_by_full_path(np, path);
954 raw_spin_unlock_irqrestore(&devtree_lock, flags);
957 EXPORT_SYMBOL(of_find_node_opts_by_path);
960 * of_find_node_by_name - Find a node by its "name" property
961 * @from: The node to start searching from or NULL; the node
962 * you pass will not be searched, only the next one
963 * will. Typically, you pass what the previous call
964 * returned. of_node_put() will be called on @from.
965 * @name: The name string to match against
967 * Return: A node pointer with refcount incremented, use
968 * of_node_put() on it when done.
970 struct device_node *of_find_node_by_name(struct device_node *from,
973 struct device_node *np;
976 raw_spin_lock_irqsave(&devtree_lock, flags);
977 for_each_of_allnodes_from(from, np)
978 if (of_node_name_eq(np, name) && of_node_get(np))
981 raw_spin_unlock_irqrestore(&devtree_lock, flags);
984 EXPORT_SYMBOL(of_find_node_by_name);
987 * of_find_node_by_type - Find a node by its "device_type" property
988 * @from: The node to start searching from, or NULL to start searching
989 * the entire device tree. The node you pass will not be
990 * searched, only the next one will; typically, you pass
991 * what the previous call returned. of_node_put() will be
992 * called on from for you.
993 * @type: The type string to match against
995 * Return: A node pointer with refcount incremented, use
996 * of_node_put() on it when done.
998 struct device_node *of_find_node_by_type(struct device_node *from,
1001 struct device_node *np;
1002 unsigned long flags;
1004 raw_spin_lock_irqsave(&devtree_lock, flags);
1005 for_each_of_allnodes_from(from, np)
1006 if (__of_node_is_type(np, type) && of_node_get(np))
1009 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1012 EXPORT_SYMBOL(of_find_node_by_type);
1015 * of_find_compatible_node - Find a node based on type and one of the
1016 * tokens in its "compatible" property
1017 * @from: The node to start searching from or NULL, the node
1018 * you pass will not be searched, only the next one
1019 * will; typically, you pass what the previous call
1020 * returned. of_node_put() will be called on it
1021 * @type: The type string to match "device_type" or NULL to ignore
1022 * @compatible: The string to match to one of the tokens in the device
1023 * "compatible" list.
1025 * Return: A node pointer with refcount incremented, use
1026 * of_node_put() on it when done.
1028 struct device_node *of_find_compatible_node(struct device_node *from,
1029 const char *type, const char *compatible)
1031 struct device_node *np;
1032 unsigned long flags;
1034 raw_spin_lock_irqsave(&devtree_lock, flags);
1035 for_each_of_allnodes_from(from, np)
1036 if (__of_device_is_compatible(np, compatible, type, NULL) &&
1040 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1043 EXPORT_SYMBOL(of_find_compatible_node);
1046 * of_find_node_with_property - Find a node which has a property with
1048 * @from: The node to start searching from or NULL, the node
1049 * you pass will not be searched, only the next one
1050 * will; typically, you pass what the previous call
1051 * returned. of_node_put() will be called on it
1052 * @prop_name: The name of the property to look for.
1054 * Return: A node pointer with refcount incremented, use
1055 * of_node_put() on it when done.
1057 struct device_node *of_find_node_with_property(struct device_node *from,
1058 const char *prop_name)
1060 struct device_node *np;
1061 struct property *pp;
1062 unsigned long flags;
1064 raw_spin_lock_irqsave(&devtree_lock, flags);
1065 for_each_of_allnodes_from(from, np) {
1066 for (pp = np->properties; pp; pp = pp->next) {
1067 if (of_prop_cmp(pp->name, prop_name) == 0) {
1075 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1078 EXPORT_SYMBOL(of_find_node_with_property);
1081 const struct of_device_id *__of_match_node(const struct of_device_id *matches,
1082 const struct device_node *node)
1084 const struct of_device_id *best_match = NULL;
1085 int score, best_score = 0;
1090 for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
1091 score = __of_device_is_compatible(node, matches->compatible,
1092 matches->type, matches->name);
1093 if (score > best_score) {
1094 best_match = matches;
1103 * of_match_node - Tell if a device_node has a matching of_match structure
1104 * @matches: array of of device match structures to search in
1105 * @node: the of device structure to match against
1107 * Low level utility function used by device matching.
1109 const struct of_device_id *of_match_node(const struct of_device_id *matches,
1110 const struct device_node *node)
1112 const struct of_device_id *match;
1113 unsigned long flags;
1115 raw_spin_lock_irqsave(&devtree_lock, flags);
1116 match = __of_match_node(matches, node);
1117 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1120 EXPORT_SYMBOL(of_match_node);
1123 * of_find_matching_node_and_match - Find a node based on an of_device_id
1125 * @from: The node to start searching from or NULL, the node
1126 * you pass will not be searched, only the next one
1127 * will; typically, you pass what the previous call
1128 * returned. of_node_put() will be called on it
1129 * @matches: array of of device match structures to search in
1130 * @match: Updated to point at the matches entry which matched
1132 * Return: A node pointer with refcount incremented, use
1133 * of_node_put() on it when done.
1135 struct device_node *of_find_matching_node_and_match(struct device_node *from,
1136 const struct of_device_id *matches,
1137 const struct of_device_id **match)
1139 struct device_node *np;
1140 const struct of_device_id *m;
1141 unsigned long flags;
1146 raw_spin_lock_irqsave(&devtree_lock, flags);
1147 for_each_of_allnodes_from(from, np) {
1148 m = __of_match_node(matches, np);
1149 if (m && of_node_get(np)) {
1156 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1159 EXPORT_SYMBOL(of_find_matching_node_and_match);
1162 * of_modalias_node - Lookup appropriate modalias for a device node
1163 * @node: pointer to a device tree node
1164 * @modalias: Pointer to buffer that modalias value will be copied into
1165 * @len: Length of modalias value
1167 * Based on the value of the compatible property, this routine will attempt
1168 * to choose an appropriate modalias value for a particular device tree node.
1169 * It does this by stripping the manufacturer prefix (as delimited by a ',')
1170 * from the first entry in the compatible list property.
1172 * Return: This routine returns 0 on success, <0 on failure.
1174 int of_modalias_node(struct device_node *node, char *modalias, int len)
1176 const char *compatible, *p;
1179 compatible = of_get_property(node, "compatible", &cplen);
1180 if (!compatible || strlen(compatible) > cplen)
1182 p = strchr(compatible, ',');
1183 strlcpy(modalias, p ? p + 1 : compatible, len);
1186 EXPORT_SYMBOL_GPL(of_modalias_node);
1189 * of_find_node_by_phandle - Find a node given a phandle
1190 * @handle: phandle of the node to find
1192 * Return: A node pointer with refcount incremented, use
1193 * of_node_put() on it when done.
1195 struct device_node *of_find_node_by_phandle(phandle handle)
1197 struct device_node *np = NULL;
1198 unsigned long flags;
1204 handle_hash = of_phandle_cache_hash(handle);
1206 raw_spin_lock_irqsave(&devtree_lock, flags);
1208 if (phandle_cache[handle_hash] &&
1209 handle == phandle_cache[handle_hash]->phandle)
1210 np = phandle_cache[handle_hash];
1213 for_each_of_allnodes(np)
1214 if (np->phandle == handle &&
1215 !of_node_check_flag(np, OF_DETACHED)) {
1216 phandle_cache[handle_hash] = np;
1222 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1225 EXPORT_SYMBOL(of_find_node_by_phandle);
1227 void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
1230 printk("%s %pOF", msg, args->np);
1231 for (i = 0; i < args->args_count; i++) {
1232 const char delim = i ? ',' : ':';
1234 pr_cont("%c%08x", delim, args->args[i]);
1239 int of_phandle_iterator_init(struct of_phandle_iterator *it,
1240 const struct device_node *np,
1241 const char *list_name,
1242 const char *cells_name,
1248 memset(it, 0, sizeof(*it));
1251 * one of cell_count or cells_name must be provided to determine the
1254 if (cell_count < 0 && !cells_name)
1257 list = of_get_property(np, list_name, &size);
1261 it->cells_name = cells_name;
1262 it->cell_count = cell_count;
1264 it->list_end = list + size / sizeof(*list);
1265 it->phandle_end = list;
1270 EXPORT_SYMBOL_GPL(of_phandle_iterator_init);
1272 int of_phandle_iterator_next(struct of_phandle_iterator *it)
1277 of_node_put(it->node);
1281 if (!it->cur || it->phandle_end >= it->list_end)
1284 it->cur = it->phandle_end;
1286 /* If phandle is 0, then it is an empty entry with no arguments. */
1287 it->phandle = be32_to_cpup(it->cur++);
1292 * Find the provider node and parse the #*-cells property to
1293 * determine the argument length.
1295 it->node = of_find_node_by_phandle(it->phandle);
1297 if (it->cells_name) {
1299 pr_err("%pOF: could not find phandle %d\n",
1300 it->parent, it->phandle);
1304 if (of_property_read_u32(it->node, it->cells_name,
1307 * If both cell_count and cells_name is given,
1308 * fall back to cell_count in absence
1309 * of the cells_name property
1311 if (it->cell_count >= 0) {
1312 count = it->cell_count;
1314 pr_err("%pOF: could not get %s for %pOF\n",
1322 count = it->cell_count;
1326 * Make sure that the arguments actually fit in the remaining
1327 * property data length
1329 if (it->cur + count > it->list_end) {
1330 pr_err("%pOF: %s = %d found %d\n",
1331 it->parent, it->cells_name,
1332 count, it->cell_count);
1337 it->phandle_end = it->cur + count;
1338 it->cur_count = count;
1344 of_node_put(it->node);
1350 EXPORT_SYMBOL_GPL(of_phandle_iterator_next);
1352 int of_phandle_iterator_args(struct of_phandle_iterator *it,
1358 count = it->cur_count;
1360 if (WARN_ON(size < count))
1363 for (i = 0; i < count; i++)
1364 args[i] = be32_to_cpup(it->cur++);
1369 static int __of_parse_phandle_with_args(const struct device_node *np,
1370 const char *list_name,
1371 const char *cells_name,
1372 int cell_count, int index,
1373 struct of_phandle_args *out_args)
1375 struct of_phandle_iterator it;
1376 int rc, cur_index = 0;
1378 /* Loop over the phandles until all the requested entry is found */
1379 of_for_each_phandle(&it, rc, np, list_name, cells_name, cell_count) {
1381 * All of the error cases bail out of the loop, so at
1382 * this point, the parsing is successful. If the requested
1383 * index matches, then fill the out_args structure and return,
1384 * or return -ENOENT for an empty entry.
1387 if (cur_index == index) {
1394 c = of_phandle_iterator_args(&it,
1397 out_args->np = it.node;
1398 out_args->args_count = c;
1400 of_node_put(it.node);
1403 /* Found it! return success */
1411 * Unlock node before returning result; will be one of:
1412 * -ENOENT : index is for empty phandle
1413 * -EINVAL : parsing error on data
1417 of_node_put(it.node);
1422 * of_parse_phandle - Resolve a phandle property to a device_node pointer
1423 * @np: Pointer to device node holding phandle property
1424 * @phandle_name: Name of property holding a phandle value
1425 * @index: For properties holding a table of phandles, this is the index into
1428 * Return: The device_node pointer with refcount incremented. Use
1429 * of_node_put() on it when done.
1431 struct device_node *of_parse_phandle(const struct device_node *np,
1432 const char *phandle_name, int index)
1434 struct of_phandle_args args;
1439 if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0,
1445 EXPORT_SYMBOL(of_parse_phandle);
1448 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
1449 * @np: pointer to a device tree node containing a list
1450 * @list_name: property name that contains a list
1451 * @cells_name: property name that specifies phandles' arguments count
1452 * @index: index of a phandle to parse out
1453 * @out_args: optional pointer to output arguments structure (will be filled)
1455 * This function is useful to parse lists of phandles and their arguments.
1456 * Returns 0 on success and fills out_args, on error returns appropriate
1459 * Caller is responsible to call of_node_put() on the returned out_args->np
1465 * #list-cells = <2>;
1469 * #list-cells = <1>;
1473 * list = <&phandle1 1 2 &phandle2 3>;
1476 * To get a device_node of the ``node2`` node you may call this:
1477 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
1479 int of_parse_phandle_with_args(const struct device_node *np, const char *list_name,
1480 const char *cells_name, int index,
1481 struct of_phandle_args *out_args)
1483 int cell_count = -1;
1488 /* If cells_name is NULL we assume a cell count of 0 */
1492 return __of_parse_phandle_with_args(np, list_name, cells_name,
1493 cell_count, index, out_args);
1495 EXPORT_SYMBOL(of_parse_phandle_with_args);
1498 * of_parse_phandle_with_args_map() - Find a node pointed by phandle in a list and remap it
1499 * @np: pointer to a device tree node containing a list
1500 * @list_name: property name that contains a list
1501 * @stem_name: stem of property names that specify phandles' arguments count
1502 * @index: index of a phandle to parse out
1503 * @out_args: optional pointer to output arguments structure (will be filled)
1505 * This function is useful to parse lists of phandles and their arguments.
1506 * Returns 0 on success and fills out_args, on error returns appropriate errno
1507 * value. The difference between this function and of_parse_phandle_with_args()
1508 * is that this API remaps a phandle if the node the phandle points to has
1509 * a <@stem_name>-map property.
1511 * Caller is responsible to call of_node_put() on the returned out_args->np
1517 * #list-cells = <2>;
1521 * #list-cells = <1>;
1525 * #list-cells = <1>;
1526 * list-map = <0 &phandle2 3>,
1528 * <2 &phandle1 5 1>;
1529 * list-map-mask = <0x3>;
1533 * list = <&phandle1 1 2 &phandle3 0>;
1536 * To get a device_node of the ``node2`` node you may call this:
1537 * of_parse_phandle_with_args(node4, "list", "list", 1, &args);
1539 int of_parse_phandle_with_args_map(const struct device_node *np,
1540 const char *list_name,
1541 const char *stem_name,
1542 int index, struct of_phandle_args *out_args)
1544 char *cells_name, *map_name = NULL, *mask_name = NULL;
1545 char *pass_name = NULL;
1546 struct device_node *cur, *new = NULL;
1547 const __be32 *map, *mask, *pass;
1548 static const __be32 dummy_mask[] = { [0 ... MAX_PHANDLE_ARGS] = ~0 };
1549 static const __be32 dummy_pass[] = { [0 ... MAX_PHANDLE_ARGS] = 0 };
1550 __be32 initial_match_array[MAX_PHANDLE_ARGS];
1551 const __be32 *match_array = initial_match_array;
1552 int i, ret, map_len, match;
1553 u32 list_size, new_size;
1558 cells_name = kasprintf(GFP_KERNEL, "#%s-cells", stem_name);
1563 map_name = kasprintf(GFP_KERNEL, "%s-map", stem_name);
1567 mask_name = kasprintf(GFP_KERNEL, "%s-map-mask", stem_name);
1571 pass_name = kasprintf(GFP_KERNEL, "%s-map-pass-thru", stem_name);
1575 ret = __of_parse_phandle_with_args(np, list_name, cells_name, -1, index,
1580 /* Get the #<list>-cells property */
1582 ret = of_property_read_u32(cur, cells_name, &list_size);
1586 /* Precalculate the match array - this simplifies match loop */
1587 for (i = 0; i < list_size; i++)
1588 initial_match_array[i] = cpu_to_be32(out_args->args[i]);
1592 /* Get the <list>-map property */
1593 map = of_get_property(cur, map_name, &map_len);
1598 map_len /= sizeof(u32);
1600 /* Get the <list>-map-mask property (optional) */
1601 mask = of_get_property(cur, mask_name, NULL);
1604 /* Iterate through <list>-map property */
1606 while (map_len > (list_size + 1) && !match) {
1607 /* Compare specifiers */
1609 for (i = 0; i < list_size; i++, map_len--)
1610 match &= !((match_array[i] ^ *map++) & mask[i]);
1613 new = of_find_node_by_phandle(be32_to_cpup(map));
1617 /* Check if not found */
1621 if (!of_device_is_available(new))
1624 ret = of_property_read_u32(new, cells_name, &new_size);
1628 /* Check for malformed properties */
1629 if (WARN_ON(new_size > MAX_PHANDLE_ARGS))
1631 if (map_len < new_size)
1634 /* Move forward by new node's #<list>-cells amount */
1636 map_len -= new_size;
1641 /* Get the <list>-map-pass-thru property (optional) */
1642 pass = of_get_property(cur, pass_name, NULL);
1647 * Successfully parsed a <list>-map translation; copy new
1648 * specifier into the out_args structure, keeping the
1649 * bits specified in <list>-map-pass-thru.
1651 match_array = map - new_size;
1652 for (i = 0; i < new_size; i++) {
1653 __be32 val = *(map - new_size + i);
1655 if (i < list_size) {
1657 val |= cpu_to_be32(out_args->args[i]) & pass[i];
1660 out_args->args[i] = be32_to_cpu(val);
1662 out_args->args_count = list_size = new_size;
1663 /* Iterate again with new provider */
1679 EXPORT_SYMBOL(of_parse_phandle_with_args_map);
1682 * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
1683 * @np: pointer to a device tree node containing a list
1684 * @list_name: property name that contains a list
1685 * @cell_count: number of argument cells following the phandle
1686 * @index: index of a phandle to parse out
1687 * @out_args: optional pointer to output arguments structure (will be filled)
1689 * This function is useful to parse lists of phandles and their arguments.
1690 * Returns 0 on success and fills out_args, on error returns appropriate
1693 * Caller is responsible to call of_node_put() on the returned out_args->np
1705 * list = <&phandle1 0 2 &phandle2 2 3>;
1708 * To get a device_node of the ``node2`` node you may call this:
1709 * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
1711 int of_parse_phandle_with_fixed_args(const struct device_node *np,
1712 const char *list_name, int cell_count,
1713 int index, struct of_phandle_args *out_args)
1717 return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
1720 EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);
1723 * of_count_phandle_with_args() - Find the number of phandles references in a property
1724 * @np: pointer to a device tree node containing a list
1725 * @list_name: property name that contains a list
1726 * @cells_name: property name that specifies phandles' arguments count
1728 * Return: The number of phandle + argument tuples within a property. It
1729 * is a typical pattern to encode a list of phandle and variable
1730 * arguments into a single property. The number of arguments is encoded
1731 * by a property in the phandle-target node. For example, a gpios
1732 * property would contain a list of GPIO specifies consisting of a
1733 * phandle and 1 or more arguments. The number of arguments are
1734 * determined by the #gpio-cells property in the node pointed to by the
1737 int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1738 const char *cells_name)
1740 struct of_phandle_iterator it;
1741 int rc, cur_index = 0;
1744 * If cells_name is NULL we assume a cell count of 0. This makes
1745 * counting the phandles trivial as each 32bit word in the list is a
1746 * phandle and no arguments are to consider. So we don't iterate through
1747 * the list but just use the length to determine the phandle count.
1753 list = of_get_property(np, list_name, &size);
1757 return size / sizeof(*list);
1760 rc = of_phandle_iterator_init(&it, np, list_name, cells_name, -1);
1764 while ((rc = of_phandle_iterator_next(&it)) == 0)
1772 EXPORT_SYMBOL(of_count_phandle_with_args);
1775 * __of_add_property - Add a property to a node without lock operations
1776 * @np: Caller's Device Node
1777 * @prop: Property to add
1779 int __of_add_property(struct device_node *np, struct property *prop)
1781 struct property **next;
1784 next = &np->properties;
1786 if (strcmp(prop->name, (*next)->name) == 0)
1787 /* duplicate ! don't insert it */
1790 next = &(*next)->next;
1798 * of_add_property - Add a property to a node
1799 * @np: Caller's Device Node
1800 * @prop: Property to add
1802 int of_add_property(struct device_node *np, struct property *prop)
1804 unsigned long flags;
1807 mutex_lock(&of_mutex);
1809 raw_spin_lock_irqsave(&devtree_lock, flags);
1810 rc = __of_add_property(np, prop);
1811 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1814 __of_add_property_sysfs(np, prop);
1816 mutex_unlock(&of_mutex);
1819 of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
1823 EXPORT_SYMBOL_GPL(of_add_property);
1825 int __of_remove_property(struct device_node *np, struct property *prop)
1827 struct property **next;
1829 for (next = &np->properties; *next; next = &(*next)->next) {
1836 /* found the node */
1838 prop->next = np->deadprops;
1839 np->deadprops = prop;
1845 * of_remove_property - Remove a property from a node.
1846 * @np: Caller's Device Node
1847 * @prop: Property to remove
1849 * Note that we don't actually remove it, since we have given out
1850 * who-knows-how-many pointers to the data using get-property.
1851 * Instead we just move the property to the "dead properties"
1852 * list, so it won't be found any more.
1854 int of_remove_property(struct device_node *np, struct property *prop)
1856 unsigned long flags;
1862 mutex_lock(&of_mutex);
1864 raw_spin_lock_irqsave(&devtree_lock, flags);
1865 rc = __of_remove_property(np, prop);
1866 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1869 __of_remove_property_sysfs(np, prop);
1871 mutex_unlock(&of_mutex);
1874 of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
1878 EXPORT_SYMBOL_GPL(of_remove_property);
1880 int __of_update_property(struct device_node *np, struct property *newprop,
1881 struct property **oldpropp)
1883 struct property **next, *oldprop;
1885 for (next = &np->properties; *next; next = &(*next)->next) {
1886 if (of_prop_cmp((*next)->name, newprop->name) == 0)
1889 *oldpropp = oldprop = *next;
1892 /* replace the node */
1893 newprop->next = oldprop->next;
1895 oldprop->next = np->deadprops;
1896 np->deadprops = oldprop;
1899 newprop->next = NULL;
1907 * of_update_property - Update a property in a node, if the property does
1908 * not exist, add it.
1910 * Note that we don't actually remove it, since we have given out
1911 * who-knows-how-many pointers to the data using get-property.
1912 * Instead we just move the property to the "dead properties" list,
1913 * and add the new property to the property list
1915 int of_update_property(struct device_node *np, struct property *newprop)
1917 struct property *oldprop;
1918 unsigned long flags;
1924 mutex_lock(&of_mutex);
1926 raw_spin_lock_irqsave(&devtree_lock, flags);
1927 rc = __of_update_property(np, newprop, &oldprop);
1928 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1931 __of_update_property_sysfs(np, newprop, oldprop);
1933 mutex_unlock(&of_mutex);
1936 of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
1941 static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1942 int id, const char *stem, int stem_len)
1946 strncpy(ap->stem, stem, stem_len);
1947 ap->stem[stem_len] = 0;
1948 list_add_tail(&ap->link, &aliases_lookup);
1949 pr_debug("adding DT alias:%s: stem=%s id=%i node=%pOF\n",
1950 ap->alias, ap->stem, ap->id, np);
1954 * of_alias_scan - Scan all properties of the 'aliases' node
1955 * @dt_alloc: An allocator that provides a virtual address to memory
1956 * for storing the resulting tree
1958 * The function scans all the properties of the 'aliases' node and populates
1959 * the global lookup table with the properties. It returns the
1960 * number of alias properties found, or an error code in case of failure.
1962 void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1964 struct property *pp;
1966 of_aliases = of_find_node_by_path("/aliases");
1967 of_chosen = of_find_node_by_path("/chosen");
1968 if (of_chosen == NULL)
1969 of_chosen = of_find_node_by_path("/chosen@0");
1972 /* linux,stdout-path and /aliases/stdout are for legacy compatibility */
1973 const char *name = NULL;
1975 if (of_property_read_string(of_chosen, "stdout-path", &name))
1976 of_property_read_string(of_chosen, "linux,stdout-path",
1978 if (IS_ENABLED(CONFIG_PPC) && !name)
1979 of_property_read_string(of_aliases, "stdout", &name);
1981 of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
1987 for_each_property_of_node(of_aliases, pp) {
1988 const char *start = pp->name;
1989 const char *end = start + strlen(start);
1990 struct device_node *np;
1991 struct alias_prop *ap;
1994 /* Skip those we do not want to proceed */
1995 if (!strcmp(pp->name, "name") ||
1996 !strcmp(pp->name, "phandle") ||
1997 !strcmp(pp->name, "linux,phandle"))
2000 np = of_find_node_by_path(pp->value);
2004 /* walk the alias backwards to extract the id and work out
2005 * the 'stem' string */
2006 while (isdigit(*(end-1)) && end > start)
2010 if (kstrtoint(end, 10, &id) < 0)
2013 /* Allocate an alias_prop with enough space for the stem */
2014 ap = dt_alloc(sizeof(*ap) + len + 1, __alignof__(*ap));
2017 memset(ap, 0, sizeof(*ap) + len + 1);
2019 of_alias_add(ap, np, id, start, len);
2024 * of_alias_get_id - Get alias id for the given device_node
2025 * @np: Pointer to the given device_node
2026 * @stem: Alias stem of the given device_node
2028 * The function travels the lookup table to get the alias id for the given
2029 * device_node and alias stem.
2031 * Return: The alias id if found.
2033 int of_alias_get_id(struct device_node *np, const char *stem)
2035 struct alias_prop *app;
2038 mutex_lock(&of_mutex);
2039 list_for_each_entry(app, &aliases_lookup, link) {
2040 if (strcmp(app->stem, stem) != 0)
2043 if (np == app->np) {
2048 mutex_unlock(&of_mutex);
2052 EXPORT_SYMBOL_GPL(of_alias_get_id);
2055 * of_alias_get_alias_list - Get alias list for the given device driver
2056 * @matches: Array of OF device match structures to search in
2057 * @stem: Alias stem of the given device_node
2058 * @bitmap: Bitmap field pointer
2059 * @nbits: Maximum number of alias IDs which can be recorded in bitmap
2061 * The function travels the lookup table to record alias ids for the given
2062 * device match structures and alias stem.
2064 * Return: 0 or -ENOSYS when !CONFIG_OF or
2065 * -EOVERFLOW if alias ID is greater then allocated nbits
2067 int of_alias_get_alias_list(const struct of_device_id *matches,
2068 const char *stem, unsigned long *bitmap,
2071 struct alias_prop *app;
2074 /* Zero bitmap field to make sure that all the time it is clean */
2075 bitmap_zero(bitmap, nbits);
2077 mutex_lock(&of_mutex);
2078 pr_debug("%s: Looking for stem: %s\n", __func__, stem);
2079 list_for_each_entry(app, &aliases_lookup, link) {
2080 pr_debug("%s: stem: %s, id: %d\n",
2081 __func__, app->stem, app->id);
2083 if (strcmp(app->stem, stem) != 0) {
2084 pr_debug("%s: stem comparison didn't pass %s\n",
2085 __func__, app->stem);
2089 if (of_match_node(matches, app->np)) {
2090 pr_debug("%s: Allocated ID %d\n", __func__, app->id);
2092 if (app->id >= nbits) {
2093 pr_warn("%s: ID %d >= than bitmap field %d\n",
2094 __func__, app->id, nbits);
2097 set_bit(app->id, bitmap);
2101 mutex_unlock(&of_mutex);
2105 EXPORT_SYMBOL_GPL(of_alias_get_alias_list);
2108 * of_alias_get_highest_id - Get highest alias id for the given stem
2109 * @stem: Alias stem to be examined
2111 * The function travels the lookup table to get the highest alias id for the
2112 * given alias stem. It returns the alias id if found.
2114 int of_alias_get_highest_id(const char *stem)
2116 struct alias_prop *app;
2119 mutex_lock(&of_mutex);
2120 list_for_each_entry(app, &aliases_lookup, link) {
2121 if (strcmp(app->stem, stem) != 0)
2127 mutex_unlock(&of_mutex);
2131 EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
2134 * of_console_check() - Test and setup console for DT setup
2135 * @dn: Pointer to device node
2136 * @name: Name to use for preferred console without index. ex. "ttyS"
2137 * @index: Index to use for preferred console.
2139 * Check if the given device node matches the stdout-path property in the
2140 * /chosen node. If it does then register it as the preferred console.
2142 * Return: TRUE if console successfully setup. Otherwise return FALSE.
2144 bool of_console_check(struct device_node *dn, char *name, int index)
2146 if (!dn || dn != of_stdout || console_set_on_cmdline)
2150 * XXX: cast `options' to char pointer to suppress complication
2151 * warnings: printk, UART and console drivers expect char pointer.
2153 return !add_preferred_console(name, index, (char *)of_stdout_options);
2155 EXPORT_SYMBOL_GPL(of_console_check);
2158 * of_find_next_cache_node - Find a node's subsidiary cache
2159 * @np: node of type "cpu" or "cache"
2161 * Return: A node pointer with refcount incremented, use
2162 * of_node_put() on it when done. Caller should hold a reference
2165 struct device_node *of_find_next_cache_node(const struct device_node *np)
2167 struct device_node *child, *cache_node;
2169 cache_node = of_parse_phandle(np, "l2-cache", 0);
2171 cache_node = of_parse_phandle(np, "next-level-cache", 0);
2176 /* OF on pmac has nodes instead of properties named "l2-cache"
2177 * beneath CPU nodes.
2179 if (IS_ENABLED(CONFIG_PPC_PMAC) && of_node_is_type(np, "cpu"))
2180 for_each_child_of_node(np, child)
2181 if (of_node_is_type(child, "cache"))
2188 * of_find_last_cache_level - Find the level at which the last cache is
2189 * present for the given logical cpu
2191 * @cpu: cpu number(logical index) for which the last cache level is needed
2193 * Return: The the level at which the last cache is present. It is exactly
2194 * same as the total number of cache levels for the given logical cpu.
2196 int of_find_last_cache_level(unsigned int cpu)
2198 u32 cache_level = 0;
2199 struct device_node *prev = NULL, *np = of_cpu_device_node_get(cpu);
2204 np = of_find_next_cache_node(np);
2207 of_property_read_u32(prev, "cache-level", &cache_level);
2213 * of_map_id - Translate an ID through a downstream mapping.
2214 * @np: root complex device node.
2215 * @id: device ID to map.
2216 * @map_name: property name of the map to use.
2217 * @map_mask_name: optional property name of the mask to use.
2218 * @target: optional pointer to a target device node.
2219 * @id_out: optional pointer to receive the translated ID.
2221 * Given a device ID, look up the appropriate implementation-defined
2222 * platform ID and/or the target device which receives transactions on that
2223 * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
2224 * @id_out may be NULL if only the other is required. If @target points to
2225 * a non-NULL device node pointer, only entries targeting that node will be
2226 * matched; if it points to a NULL value, it will receive the device node of
2227 * the first matching target phandle, with a reference held.
2229 * Return: 0 on success or a standard error code on failure.
2231 int of_map_id(struct device_node *np, u32 id,
2232 const char *map_name, const char *map_mask_name,
2233 struct device_node **target, u32 *id_out)
2235 u32 map_mask, masked_id;
2237 const __be32 *map = NULL;
2239 if (!np || !map_name || (!target && !id_out))
2242 map = of_get_property(np, map_name, &map_len);
2246 /* Otherwise, no map implies no translation */
2251 if (!map_len || map_len % (4 * sizeof(*map))) {
2252 pr_err("%pOF: Error: Bad %s length: %d\n", np,
2257 /* The default is to select all bits. */
2258 map_mask = 0xffffffff;
2261 * Can be overridden by "{iommu,msi}-map-mask" property.
2262 * If of_property_read_u32() fails, the default is used.
2265 of_property_read_u32(np, map_mask_name, &map_mask);
2267 masked_id = map_mask & id;
2268 for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
2269 struct device_node *phandle_node;
2270 u32 id_base = be32_to_cpup(map + 0);
2271 u32 phandle = be32_to_cpup(map + 1);
2272 u32 out_base = be32_to_cpup(map + 2);
2273 u32 id_len = be32_to_cpup(map + 3);
2275 if (id_base & ~map_mask) {
2276 pr_err("%pOF: Invalid %s translation - %s-mask (0x%x) ignores id-base (0x%x)\n",
2277 np, map_name, map_name,
2282 if (masked_id < id_base || masked_id >= id_base + id_len)
2285 phandle_node = of_find_node_by_phandle(phandle);
2291 of_node_put(phandle_node);
2293 *target = phandle_node;
2295 if (*target != phandle_node)
2300 *id_out = masked_id - id_base + out_base;
2302 pr_debug("%pOF: %s, using mask %08x, id-base: %08x, out-base: %08x, length: %08x, id: %08x -> %08x\n",
2303 np, map_name, map_mask, id_base, out_base,
2304 id_len, id, masked_id - id_base + out_base);
2308 pr_info("%pOF: no %s translation for id 0x%x on %pOF\n", np, map_name,
2309 id, target && *target ? *target : NULL);
2311 /* Bypasses translation */
2316 EXPORT_SYMBOL_GPL(of_map_id);