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 struct device_node *of_aliases;
40 struct device_node *of_stdout;
41 static const char *of_stdout_options;
46 * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
47 * This mutex must be held whenever modifications are being made to the
48 * device tree. The of_{attach,detach}_node() and
49 * of_{add,remove,update}_property() helpers make sure this happens.
51 DEFINE_MUTEX(of_mutex);
53 /* use when traversing tree through the child, sibling,
54 * or parent members of struct device_node.
56 DEFINE_RAW_SPINLOCK(devtree_lock);
58 bool of_node_name_eq(const struct device_node *np, const char *name)
60 const char *node_name;
66 node_name = kbasename(np->full_name);
67 len = strchrnul(node_name, '@') - node_name;
69 return (strlen(name) == len) && (strncmp(node_name, name, len) == 0);
71 EXPORT_SYMBOL(of_node_name_eq);
73 bool of_node_name_prefix(const struct device_node *np, const char *prefix)
78 return strncmp(kbasename(np->full_name), prefix, strlen(prefix)) == 0;
80 EXPORT_SYMBOL(of_node_name_prefix);
82 int of_n_addr_cells(struct device_node *np)
89 if (!of_property_read_u32(np, "#address-cells", &cells))
92 /* No #address-cells property for the root node */
93 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
95 EXPORT_SYMBOL(of_n_addr_cells);
97 int of_n_size_cells(struct device_node *np)
104 if (!of_property_read_u32(np, "#size-cells", &cells))
106 } while (np->parent);
107 /* No #size-cells property for the root node */
108 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
110 EXPORT_SYMBOL(of_n_size_cells);
113 int __weak of_node_to_nid(struct device_node *np)
119 static struct device_node **phandle_cache;
120 static u32 phandle_cache_mask;
123 * Assumptions behind phandle_cache implementation:
124 * - phandle property values are in a contiguous range of 1..n
126 * If the assumptions do not hold, then
127 * - the phandle lookup overhead reduction provided by the cache
128 * will likely be less
130 void of_populate_phandle_cache(void)
134 struct device_node *np;
137 raw_spin_lock_irqsave(&devtree_lock, flags);
139 kfree(phandle_cache);
140 phandle_cache = NULL;
142 for_each_of_allnodes(np)
143 if (np->phandle && np->phandle != OF_PHANDLE_ILLEGAL)
149 cache_entries = roundup_pow_of_two(phandles);
150 phandle_cache_mask = cache_entries - 1;
152 phandle_cache = kcalloc(cache_entries, sizeof(*phandle_cache),
157 for_each_of_allnodes(np)
158 if (np->phandle && np->phandle != OF_PHANDLE_ILLEGAL)
159 phandle_cache[np->phandle & phandle_cache_mask] = np;
162 raw_spin_unlock_irqrestore(&devtree_lock, flags);
165 int of_free_phandle_cache(void)
169 raw_spin_lock_irqsave(&devtree_lock, flags);
171 kfree(phandle_cache);
172 phandle_cache = NULL;
174 raw_spin_unlock_irqrestore(&devtree_lock, flags);
178 #if !defined(CONFIG_MODULES)
179 late_initcall_sync(of_free_phandle_cache);
182 void __init of_core_init(void)
184 struct device_node *np;
186 of_populate_phandle_cache();
188 /* Create the kset, and register existing nodes */
189 mutex_lock(&of_mutex);
190 of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
192 mutex_unlock(&of_mutex);
193 pr_err("failed to register existing nodes\n");
196 for_each_of_allnodes(np)
197 __of_attach_node_sysfs(np);
198 mutex_unlock(&of_mutex);
200 /* Symlink in /proc as required by userspace ABI */
202 proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
205 static struct property *__of_find_property(const struct device_node *np,
206 const char *name, int *lenp)
213 for (pp = np->properties; pp; pp = pp->next) {
214 if (of_prop_cmp(pp->name, name) == 0) {
224 struct property *of_find_property(const struct device_node *np,
231 raw_spin_lock_irqsave(&devtree_lock, flags);
232 pp = __of_find_property(np, name, lenp);
233 raw_spin_unlock_irqrestore(&devtree_lock, flags);
237 EXPORT_SYMBOL(of_find_property);
239 struct device_node *__of_find_all_nodes(struct device_node *prev)
241 struct device_node *np;
244 } else if (prev->child) {
247 /* Walk back up looking for a sibling, or the end of the structure */
249 while (np->parent && !np->sibling)
251 np = np->sibling; /* Might be null at the end of the tree */
257 * of_find_all_nodes - Get next node in global list
258 * @prev: Previous node or NULL to start iteration
259 * of_node_put() will be called on it
261 * Returns a node pointer with refcount incremented, use
262 * of_node_put() on it when done.
264 struct device_node *of_find_all_nodes(struct device_node *prev)
266 struct device_node *np;
269 raw_spin_lock_irqsave(&devtree_lock, flags);
270 np = __of_find_all_nodes(prev);
273 raw_spin_unlock_irqrestore(&devtree_lock, flags);
276 EXPORT_SYMBOL(of_find_all_nodes);
279 * Find a property with a given name for a given node
280 * and return the value.
282 const void *__of_get_property(const struct device_node *np,
283 const char *name, int *lenp)
285 struct property *pp = __of_find_property(np, name, lenp);
287 return pp ? pp->value : NULL;
291 * Find a property with a given name for a given node
292 * and return the value.
294 const void *of_get_property(const struct device_node *np, const char *name,
297 struct property *pp = of_find_property(np, name, lenp);
299 return pp ? pp->value : NULL;
301 EXPORT_SYMBOL(of_get_property);
304 * arch_match_cpu_phys_id - Match the given logical CPU and physical id
306 * @cpu: logical cpu index of a core/thread
307 * @phys_id: physical identifier of a core/thread
309 * CPU logical to physical index mapping is architecture specific.
310 * However this __weak function provides a default match of physical
311 * id to logical cpu index. phys_id provided here is usually values read
312 * from the device tree which must match the hardware internal registers.
314 * Returns true if the physical identifier and the logical cpu index
315 * correspond to the same core/thread, false otherwise.
317 bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
319 return (u32)phys_id == cpu;
323 * Checks if the given "prop_name" property holds the physical id of the
324 * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
325 * NULL, local thread number within the core is returned in it.
327 static bool __of_find_n_match_cpu_property(struct device_node *cpun,
328 const char *prop_name, int cpu, unsigned int *thread)
331 int ac, prop_len, tid;
334 ac = of_n_addr_cells(cpun);
335 cell = of_get_property(cpun, prop_name, &prop_len);
336 if (!cell && !ac && arch_match_cpu_phys_id(cpu, 0))
340 prop_len /= sizeof(*cell) * ac;
341 for (tid = 0; tid < prop_len; tid++) {
342 hwid = of_read_number(cell, ac);
343 if (arch_match_cpu_phys_id(cpu, hwid)) {
354 * arch_find_n_match_cpu_physical_id - See if the given device node is
355 * for the cpu corresponding to logical cpu 'cpu'. Return true if so,
356 * else false. If 'thread' is non-NULL, the local thread number within the
357 * core is returned in it.
359 bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
360 int cpu, unsigned int *thread)
362 /* Check for non-standard "ibm,ppc-interrupt-server#s" property
363 * for thread ids on PowerPC. If it doesn't exist fallback to
364 * standard "reg" property.
366 if (IS_ENABLED(CONFIG_PPC) &&
367 __of_find_n_match_cpu_property(cpun,
368 "ibm,ppc-interrupt-server#s",
372 return __of_find_n_match_cpu_property(cpun, "reg", cpu, thread);
376 * of_get_cpu_node - Get device node associated with the given logical CPU
378 * @cpu: CPU number(logical index) for which device node is required
379 * @thread: if not NULL, local thread number within the physical core is
382 * The main purpose of this function is to retrieve the device node for the
383 * given logical CPU index. It should be used to initialize the of_node in
384 * cpu device. Once of_node in cpu device is populated, all the further
385 * references can use that instead.
387 * CPU logical to physical index mapping is architecture specific and is built
388 * before booting secondary cores. This function uses arch_match_cpu_phys_id
389 * which can be overridden by architecture specific implementation.
391 * Returns a node pointer for the logical cpu with refcount incremented, use
392 * of_node_put() on it when done. Returns NULL if not found.
394 struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
396 struct device_node *cpun;
398 for_each_of_cpu_node(cpun) {
399 if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
404 EXPORT_SYMBOL(of_get_cpu_node);
407 * of_cpu_node_to_id: Get the logical CPU number for a given device_node
409 * @cpu_node: Pointer to the device_node for CPU.
411 * Returns the logical CPU number of the given CPU device_node.
412 * Returns -ENODEV if the CPU is not found.
414 int of_cpu_node_to_id(struct device_node *cpu_node)
418 struct device_node *np;
420 for_each_possible_cpu(cpu) {
421 np = of_cpu_device_node_get(cpu);
422 found = (cpu_node == np);
430 EXPORT_SYMBOL(of_cpu_node_to_id);
433 * __of_device_is_compatible() - Check if the node matches given constraints
434 * @device: pointer to node
435 * @compat: required compatible string, NULL or "" for any match
436 * @type: required device_type value, NULL or "" for any match
437 * @name: required node name, NULL or "" for any match
439 * Checks if the given @compat, @type and @name strings match the
440 * properties of the given @device. A constraints can be skipped by
441 * passing NULL or an empty string as the constraint.
443 * Returns 0 for no match, and a positive integer on match. The return
444 * value is a relative score with larger values indicating better
445 * matches. The score is weighted for the most specific compatible value
446 * to get the highest score. Matching type is next, followed by matching
447 * name. Practically speaking, this results in the following priority
450 * 1. specific compatible && type && name
451 * 2. specific compatible && type
452 * 3. specific compatible && name
453 * 4. specific compatible
454 * 5. general compatible && type && name
455 * 6. general compatible && type
456 * 7. general compatible && name
457 * 8. general compatible
462 static int __of_device_is_compatible(const struct device_node *device,
463 const char *compat, const char *type, const char *name)
465 struct property *prop;
467 int index = 0, score = 0;
469 /* Compatible match has highest priority */
470 if (compat && compat[0]) {
471 prop = __of_find_property(device, "compatible", NULL);
472 for (cp = of_prop_next_string(prop, NULL); cp;
473 cp = of_prop_next_string(prop, cp), index++) {
474 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
475 score = INT_MAX/2 - (index << 2);
483 /* Matching type is better than matching name */
484 if (type && type[0]) {
485 if (!device->type || of_node_cmp(type, device->type))
490 /* Matching name is a bit better than not */
491 if (name && name[0]) {
492 if (!device->name || of_node_cmp(name, device->name))
500 /** Checks if the given "compat" string matches one of the strings in
501 * the device's "compatible" property
503 int of_device_is_compatible(const struct device_node *device,
509 raw_spin_lock_irqsave(&devtree_lock, flags);
510 res = __of_device_is_compatible(device, compat, NULL, NULL);
511 raw_spin_unlock_irqrestore(&devtree_lock, flags);
514 EXPORT_SYMBOL(of_device_is_compatible);
516 /** Checks if the device is compatible with any of the entries in
517 * a NULL terminated array of strings. Returns the best match
520 int of_device_compatible_match(struct device_node *device,
521 const char *const *compat)
523 unsigned int tmp, score = 0;
529 tmp = of_device_is_compatible(device, *compat);
539 * of_machine_is_compatible - Test root of device tree for a given compatible value
540 * @compat: compatible string to look for in root node's compatible property.
542 * Returns a positive integer if the root node has the given value in its
543 * compatible property.
545 int of_machine_is_compatible(const char *compat)
547 struct device_node *root;
550 root = of_find_node_by_path("/");
552 rc = of_device_is_compatible(root, compat);
557 EXPORT_SYMBOL(of_machine_is_compatible);
560 * __of_device_is_available - check if a device is available for use
562 * @device: Node to check for availability, with locks already held
564 * Returns true if the status property is absent or set to "okay" or "ok",
567 static bool __of_device_is_available(const struct device_node *device)
575 status = __of_get_property(device, "status", &statlen);
580 if (!strcmp(status, "okay") || !strcmp(status, "ok"))
588 * of_device_is_available - check if a device is available for use
590 * @device: Node to check for availability
592 * Returns true if the status property is absent or set to "okay" or "ok",
595 bool of_device_is_available(const struct device_node *device)
600 raw_spin_lock_irqsave(&devtree_lock, flags);
601 res = __of_device_is_available(device);
602 raw_spin_unlock_irqrestore(&devtree_lock, flags);
606 EXPORT_SYMBOL(of_device_is_available);
609 * of_device_is_big_endian - check if a device has BE registers
611 * @device: Node to check for endianness
613 * Returns true if the device has a "big-endian" property, or if the kernel
614 * was compiled for BE *and* the device has a "native-endian" property.
615 * Returns false otherwise.
617 * Callers would nominally use ioread32be/iowrite32be if
618 * of_device_is_big_endian() == true, or readl/writel otherwise.
620 bool of_device_is_big_endian(const struct device_node *device)
622 if (of_property_read_bool(device, "big-endian"))
624 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
625 of_property_read_bool(device, "native-endian"))
629 EXPORT_SYMBOL(of_device_is_big_endian);
632 * of_get_parent - Get a node's parent if any
633 * @node: Node to get parent
635 * Returns a node pointer with refcount incremented, use
636 * of_node_put() on it when done.
638 struct device_node *of_get_parent(const struct device_node *node)
640 struct device_node *np;
646 raw_spin_lock_irqsave(&devtree_lock, flags);
647 np = of_node_get(node->parent);
648 raw_spin_unlock_irqrestore(&devtree_lock, flags);
651 EXPORT_SYMBOL(of_get_parent);
654 * of_get_next_parent - Iterate to a node's parent
655 * @node: Node to get parent of
657 * This is like of_get_parent() except that it drops the
658 * refcount on the passed node, making it suitable for iterating
659 * through a node's parents.
661 * Returns a node pointer with refcount incremented, use
662 * of_node_put() on it when done.
664 struct device_node *of_get_next_parent(struct device_node *node)
666 struct device_node *parent;
672 raw_spin_lock_irqsave(&devtree_lock, flags);
673 parent = of_node_get(node->parent);
675 raw_spin_unlock_irqrestore(&devtree_lock, flags);
678 EXPORT_SYMBOL(of_get_next_parent);
680 static struct device_node *__of_get_next_child(const struct device_node *node,
681 struct device_node *prev)
683 struct device_node *next;
688 next = prev ? prev->sibling : node->child;
689 for (; next; next = next->sibling)
690 if (of_node_get(next))
695 #define __for_each_child_of_node(parent, child) \
696 for (child = __of_get_next_child(parent, NULL); child != NULL; \
697 child = __of_get_next_child(parent, child))
700 * of_get_next_child - Iterate a node childs
702 * @prev: previous child of the parent node, or NULL to get first
704 * Returns a node pointer with refcount incremented, use of_node_put() on
705 * it when done. Returns NULL when prev is the last child. Decrements the
708 struct device_node *of_get_next_child(const struct device_node *node,
709 struct device_node *prev)
711 struct device_node *next;
714 raw_spin_lock_irqsave(&devtree_lock, flags);
715 next = __of_get_next_child(node, prev);
716 raw_spin_unlock_irqrestore(&devtree_lock, flags);
719 EXPORT_SYMBOL(of_get_next_child);
722 * of_get_next_available_child - Find the next available child node
724 * @prev: previous child of the parent node, or NULL to get first
726 * This function is like of_get_next_child(), except that it
727 * automatically skips any disabled nodes (i.e. status = "disabled").
729 struct device_node *of_get_next_available_child(const struct device_node *node,
730 struct device_node *prev)
732 struct device_node *next;
738 raw_spin_lock_irqsave(&devtree_lock, flags);
739 next = prev ? prev->sibling : node->child;
740 for (; next; next = next->sibling) {
741 if (!__of_device_is_available(next))
743 if (of_node_get(next))
747 raw_spin_unlock_irqrestore(&devtree_lock, flags);
750 EXPORT_SYMBOL(of_get_next_available_child);
753 * of_get_next_cpu_node - Iterate on cpu nodes
754 * @prev: previous child of the /cpus node, or NULL to get first
756 * Returns a cpu node pointer with refcount incremented, use of_node_put()
757 * on it when done. Returns NULL when prev is the last child. Decrements
758 * the refcount of prev.
760 struct device_node *of_get_next_cpu_node(struct device_node *prev)
762 struct device_node *next = NULL;
764 struct device_node *node;
767 node = of_find_node_by_path("/cpus");
769 raw_spin_lock_irqsave(&devtree_lock, flags);
771 next = prev->sibling;
776 for (; next; next = next->sibling) {
777 if (!(of_node_name_eq(next, "cpu") ||
778 (next->type && !of_node_cmp(next->type, "cpu"))))
780 if (of_node_get(next))
784 raw_spin_unlock_irqrestore(&devtree_lock, flags);
787 EXPORT_SYMBOL(of_get_next_cpu_node);
790 * of_get_compatible_child - Find compatible child node
791 * @parent: parent node
792 * @compatible: compatible string
794 * Lookup child node whose compatible property contains the given compatible
797 * Returns a node pointer with refcount incremented, use of_node_put() on it
798 * when done; or NULL if not found.
800 struct device_node *of_get_compatible_child(const struct device_node *parent,
801 const char *compatible)
803 struct device_node *child;
805 for_each_child_of_node(parent, child) {
806 if (of_device_is_compatible(child, compatible))
812 EXPORT_SYMBOL(of_get_compatible_child);
815 * of_get_child_by_name - Find the child node by name for a given parent
817 * @name: child name to look for.
819 * This function looks for child node for given matching name
821 * Returns a node pointer if found, with refcount incremented, use
822 * of_node_put() on it when done.
823 * Returns NULL if node is not found.
825 struct device_node *of_get_child_by_name(const struct device_node *node,
828 struct device_node *child;
830 for_each_child_of_node(node, child)
831 if (child->name && (of_node_cmp(child->name, name) == 0))
835 EXPORT_SYMBOL(of_get_child_by_name);
837 struct device_node *__of_find_node_by_path(struct device_node *parent,
840 struct device_node *child;
843 len = strcspn(path, "/:");
847 __for_each_child_of_node(parent, child) {
848 const char *name = kbasename(child->full_name);
849 if (strncmp(path, name, len) == 0 && (strlen(name) == len))
855 struct device_node *__of_find_node_by_full_path(struct device_node *node,
858 const char *separator = strchr(path, ':');
860 while (node && *path == '/') {
861 struct device_node *tmp = node;
863 path++; /* Increment past '/' delimiter */
864 node = __of_find_node_by_path(node, path);
866 path = strchrnul(path, '/');
867 if (separator && separator < path)
874 * of_find_node_opts_by_path - Find a node matching a full OF path
875 * @path: Either the full path to match, or if the path does not
876 * start with '/', the name of a property of the /aliases
877 * node (an alias). In the case of an alias, the node
878 * matching the alias' value will be returned.
879 * @opts: Address of a pointer into which to store the start of
880 * an options string appended to the end of the path with
886 * foo/bar Valid alias + relative path
888 * Returns a node pointer with refcount incremented, use
889 * of_node_put() on it when done.
891 struct device_node *of_find_node_opts_by_path(const char *path, const char **opts)
893 struct device_node *np = NULL;
896 const char *separator = strchr(path, ':');
899 *opts = separator ? separator + 1 : NULL;
901 if (strcmp(path, "/") == 0)
902 return of_node_get(of_root);
904 /* The path could begin with an alias */
907 const char *p = separator;
910 p = strchrnul(path, '/');
913 /* of_aliases must not be NULL */
917 for_each_property_of_node(of_aliases, pp) {
918 if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
919 np = of_find_node_by_path(pp->value);
928 /* Step down the tree matching path components */
929 raw_spin_lock_irqsave(&devtree_lock, flags);
931 np = of_node_get(of_root);
932 np = __of_find_node_by_full_path(np, path);
933 raw_spin_unlock_irqrestore(&devtree_lock, flags);
936 EXPORT_SYMBOL(of_find_node_opts_by_path);
939 * of_find_node_by_name - Find a node by its "name" property
940 * @from: The node to start searching from or NULL; the node
941 * you pass will not be searched, only the next one
942 * will. Typically, you pass what the previous call
943 * returned. of_node_put() will be called on @from.
944 * @name: The name string to match against
946 * Returns a node pointer with refcount incremented, use
947 * of_node_put() on it when done.
949 struct device_node *of_find_node_by_name(struct device_node *from,
952 struct device_node *np;
955 raw_spin_lock_irqsave(&devtree_lock, flags);
956 for_each_of_allnodes_from(from, np)
957 if (np->name && (of_node_cmp(np->name, name) == 0)
961 raw_spin_unlock_irqrestore(&devtree_lock, flags);
964 EXPORT_SYMBOL(of_find_node_by_name);
967 * of_find_node_by_type - Find a node by its "device_type" property
968 * @from: The node to start searching from, or NULL to start searching
969 * the entire device tree. The node you pass will not be
970 * searched, only the next one will; typically, you pass
971 * what the previous call returned. of_node_put() will be
972 * called on from for you.
973 * @type: The type string to match against
975 * Returns a node pointer with refcount incremented, use
976 * of_node_put() on it when done.
978 struct device_node *of_find_node_by_type(struct device_node *from,
981 struct device_node *np;
984 raw_spin_lock_irqsave(&devtree_lock, flags);
985 for_each_of_allnodes_from(from, np)
986 if (np->type && (of_node_cmp(np->type, type) == 0)
990 raw_spin_unlock_irqrestore(&devtree_lock, flags);
993 EXPORT_SYMBOL(of_find_node_by_type);
996 * of_find_compatible_node - Find a node based on type and one of the
997 * tokens in its "compatible" property
998 * @from: The node to start searching from or NULL, the node
999 * you pass will not be searched, only the next one
1000 * will; typically, you pass what the previous call
1001 * returned. of_node_put() will be called on it
1002 * @type: The type string to match "device_type" or NULL to ignore
1003 * @compatible: The string to match to one of the tokens in the device
1004 * "compatible" list.
1006 * Returns a node pointer with refcount incremented, use
1007 * of_node_put() on it when done.
1009 struct device_node *of_find_compatible_node(struct device_node *from,
1010 const char *type, const char *compatible)
1012 struct device_node *np;
1013 unsigned long flags;
1015 raw_spin_lock_irqsave(&devtree_lock, flags);
1016 for_each_of_allnodes_from(from, np)
1017 if (__of_device_is_compatible(np, compatible, type, NULL) &&
1021 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1024 EXPORT_SYMBOL(of_find_compatible_node);
1027 * of_find_node_with_property - Find a node which has a property with
1029 * @from: The node to start searching from or NULL, the node
1030 * you pass will not be searched, only the next one
1031 * will; typically, you pass what the previous call
1032 * returned. of_node_put() will be called on it
1033 * @prop_name: The name of the property to look for.
1035 * Returns a node pointer with refcount incremented, use
1036 * of_node_put() on it when done.
1038 struct device_node *of_find_node_with_property(struct device_node *from,
1039 const char *prop_name)
1041 struct device_node *np;
1042 struct property *pp;
1043 unsigned long flags;
1045 raw_spin_lock_irqsave(&devtree_lock, flags);
1046 for_each_of_allnodes_from(from, np) {
1047 for (pp = np->properties; pp; pp = pp->next) {
1048 if (of_prop_cmp(pp->name, prop_name) == 0) {
1056 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1059 EXPORT_SYMBOL(of_find_node_with_property);
1062 const struct of_device_id *__of_match_node(const struct of_device_id *matches,
1063 const struct device_node *node)
1065 const struct of_device_id *best_match = NULL;
1066 int score, best_score = 0;
1071 for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
1072 score = __of_device_is_compatible(node, matches->compatible,
1073 matches->type, matches->name);
1074 if (score > best_score) {
1075 best_match = matches;
1084 * of_match_node - Tell if a device_node has a matching of_match structure
1085 * @matches: array of of device match structures to search in
1086 * @node: the of device structure to match against
1088 * Low level utility function used by device matching.
1090 const struct of_device_id *of_match_node(const struct of_device_id *matches,
1091 const struct device_node *node)
1093 const struct of_device_id *match;
1094 unsigned long flags;
1096 raw_spin_lock_irqsave(&devtree_lock, flags);
1097 match = __of_match_node(matches, node);
1098 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1101 EXPORT_SYMBOL(of_match_node);
1104 * of_find_matching_node_and_match - Find a node based on an of_device_id
1106 * @from: The node to start searching from or NULL, the node
1107 * you pass will not be searched, only the next one
1108 * will; typically, you pass what the previous call
1109 * returned. of_node_put() will be called on it
1110 * @matches: array of of device match structures to search in
1111 * @match Updated to point at the matches entry which matched
1113 * Returns a node pointer with refcount incremented, use
1114 * of_node_put() on it when done.
1116 struct device_node *of_find_matching_node_and_match(struct device_node *from,
1117 const struct of_device_id *matches,
1118 const struct of_device_id **match)
1120 struct device_node *np;
1121 const struct of_device_id *m;
1122 unsigned long flags;
1127 raw_spin_lock_irqsave(&devtree_lock, flags);
1128 for_each_of_allnodes_from(from, np) {
1129 m = __of_match_node(matches, np);
1130 if (m && of_node_get(np)) {
1137 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1140 EXPORT_SYMBOL(of_find_matching_node_and_match);
1143 * of_modalias_node - Lookup appropriate modalias for a device node
1144 * @node: pointer to a device tree node
1145 * @modalias: Pointer to buffer that modalias value will be copied into
1146 * @len: Length of modalias value
1148 * Based on the value of the compatible property, this routine will attempt
1149 * to choose an appropriate modalias value for a particular device tree node.
1150 * It does this by stripping the manufacturer prefix (as delimited by a ',')
1151 * from the first entry in the compatible list property.
1153 * This routine returns 0 on success, <0 on failure.
1155 int of_modalias_node(struct device_node *node, char *modalias, int len)
1157 const char *compatible, *p;
1160 compatible = of_get_property(node, "compatible", &cplen);
1161 if (!compatible || strlen(compatible) > cplen)
1163 p = strchr(compatible, ',');
1164 strlcpy(modalias, p ? p + 1 : compatible, len);
1167 EXPORT_SYMBOL_GPL(of_modalias_node);
1170 * of_find_node_by_phandle - Find a node given a phandle
1171 * @handle: phandle of the node to find
1173 * Returns a node pointer with refcount incremented, use
1174 * of_node_put() on it when done.
1176 struct device_node *of_find_node_by_phandle(phandle handle)
1178 struct device_node *np = NULL;
1179 unsigned long flags;
1180 phandle masked_handle;
1185 raw_spin_lock_irqsave(&devtree_lock, flags);
1187 masked_handle = handle & phandle_cache_mask;
1189 if (phandle_cache) {
1190 if (phandle_cache[masked_handle] &&
1191 handle == phandle_cache[masked_handle]->phandle)
1192 np = phandle_cache[masked_handle];
1196 for_each_of_allnodes(np)
1197 if (np->phandle == handle) {
1199 phandle_cache[masked_handle] = np;
1205 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1208 EXPORT_SYMBOL(of_find_node_by_phandle);
1210 void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
1213 printk("%s %pOF", msg, args->np);
1214 for (i = 0; i < args->args_count; i++) {
1215 const char delim = i ? ',' : ':';
1217 pr_cont("%c%08x", delim, args->args[i]);
1222 int of_phandle_iterator_init(struct of_phandle_iterator *it,
1223 const struct device_node *np,
1224 const char *list_name,
1225 const char *cells_name,
1231 memset(it, 0, sizeof(*it));
1233 list = of_get_property(np, list_name, &size);
1237 it->cells_name = cells_name;
1238 it->cell_count = cell_count;
1240 it->list_end = list + size / sizeof(*list);
1241 it->phandle_end = list;
1246 EXPORT_SYMBOL_GPL(of_phandle_iterator_init);
1248 int of_phandle_iterator_next(struct of_phandle_iterator *it)
1253 of_node_put(it->node);
1257 if (!it->cur || it->phandle_end >= it->list_end)
1260 it->cur = it->phandle_end;
1262 /* If phandle is 0, then it is an empty entry with no arguments. */
1263 it->phandle = be32_to_cpup(it->cur++);
1268 * Find the provider node and parse the #*-cells property to
1269 * determine the argument length.
1271 it->node = of_find_node_by_phandle(it->phandle);
1273 if (it->cells_name) {
1275 pr_err("%pOF: could not find phandle\n",
1280 if (of_property_read_u32(it->node, it->cells_name,
1282 pr_err("%pOF: could not get %s for %pOF\n",
1289 count = it->cell_count;
1293 * Make sure that the arguments actually fit in the remaining
1294 * property data length
1296 if (it->cur + count > it->list_end) {
1297 pr_err("%pOF: arguments longer than property\n",
1303 it->phandle_end = it->cur + count;
1304 it->cur_count = count;
1310 of_node_put(it->node);
1316 EXPORT_SYMBOL_GPL(of_phandle_iterator_next);
1318 int of_phandle_iterator_args(struct of_phandle_iterator *it,
1324 count = it->cur_count;
1326 if (WARN_ON(size < count))
1329 for (i = 0; i < count; i++)
1330 args[i] = be32_to_cpup(it->cur++);
1335 static int __of_parse_phandle_with_args(const struct device_node *np,
1336 const char *list_name,
1337 const char *cells_name,
1338 int cell_count, int index,
1339 struct of_phandle_args *out_args)
1341 struct of_phandle_iterator it;
1342 int rc, cur_index = 0;
1344 /* Loop over the phandles until all the requested entry is found */
1345 of_for_each_phandle(&it, rc, np, list_name, cells_name, cell_count) {
1347 * All of the error cases bail out of the loop, so at
1348 * this point, the parsing is successful. If the requested
1349 * index matches, then fill the out_args structure and return,
1350 * or return -ENOENT for an empty entry.
1353 if (cur_index == index) {
1360 c = of_phandle_iterator_args(&it,
1363 out_args->np = it.node;
1364 out_args->args_count = c;
1366 of_node_put(it.node);
1369 /* Found it! return success */
1377 * Unlock node before returning result; will be one of:
1378 * -ENOENT : index is for empty phandle
1379 * -EINVAL : parsing error on data
1383 of_node_put(it.node);
1388 * of_parse_phandle - Resolve a phandle property to a device_node pointer
1389 * @np: Pointer to device node holding phandle property
1390 * @phandle_name: Name of property holding a phandle value
1391 * @index: For properties holding a table of phandles, this is the index into
1394 * Returns the device_node pointer with refcount incremented. Use
1395 * of_node_put() on it when done.
1397 struct device_node *of_parse_phandle(const struct device_node *np,
1398 const char *phandle_name, int index)
1400 struct of_phandle_args args;
1405 if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0,
1411 EXPORT_SYMBOL(of_parse_phandle);
1414 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
1415 * @np: pointer to a device tree node containing a list
1416 * @list_name: property name that contains a list
1417 * @cells_name: property name that specifies phandles' arguments count
1418 * @index: index of a phandle to parse out
1419 * @out_args: optional pointer to output arguments structure (will be filled)
1421 * This function is useful to parse lists of phandles and their arguments.
1422 * Returns 0 on success and fills out_args, on error returns appropriate
1425 * Caller is responsible to call of_node_put() on the returned out_args->np
1431 * #list-cells = <2>;
1435 * #list-cells = <1>;
1439 * list = <&phandle1 1 2 &phandle2 3>;
1442 * To get a device_node of the `node2' node you may call this:
1443 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
1445 int of_parse_phandle_with_args(const struct device_node *np, const char *list_name,
1446 const char *cells_name, int index,
1447 struct of_phandle_args *out_args)
1451 return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
1454 EXPORT_SYMBOL(of_parse_phandle_with_args);
1457 * of_parse_phandle_with_args_map() - Find a node pointed by phandle in a list and remap it
1458 * @np: pointer to a device tree node containing a list
1459 * @list_name: property name that contains a list
1460 * @stem_name: stem of property names that specify phandles' arguments count
1461 * @index: index of a phandle to parse out
1462 * @out_args: optional pointer to output arguments structure (will be filled)
1464 * This function is useful to parse lists of phandles and their arguments.
1465 * Returns 0 on success and fills out_args, on error returns appropriate errno
1466 * value. The difference between this function and of_parse_phandle_with_args()
1467 * is that this API remaps a phandle if the node the phandle points to has
1468 * a <@stem_name>-map property.
1470 * Caller is responsible to call of_node_put() on the returned out_args->np
1476 * #list-cells = <2>;
1480 * #list-cells = <1>;
1484 * #list-cells = <1>;
1485 * list-map = <0 &phandle2 3>,
1487 * <2 &phandle1 5 1>;
1488 * list-map-mask = <0x3>;
1492 * list = <&phandle1 1 2 &phandle3 0>;
1495 * To get a device_node of the `node2' node you may call this:
1496 * of_parse_phandle_with_args(node4, "list", "list", 1, &args);
1498 int of_parse_phandle_with_args_map(const struct device_node *np,
1499 const char *list_name,
1500 const char *stem_name,
1501 int index, struct of_phandle_args *out_args)
1503 char *cells_name, *map_name = NULL, *mask_name = NULL;
1504 char *pass_name = NULL;
1505 struct device_node *cur, *new = NULL;
1506 const __be32 *map, *mask, *pass;
1507 static const __be32 dummy_mask[] = { [0 ... MAX_PHANDLE_ARGS] = ~0 };
1508 static const __be32 dummy_pass[] = { [0 ... MAX_PHANDLE_ARGS] = 0 };
1509 __be32 initial_match_array[MAX_PHANDLE_ARGS];
1510 const __be32 *match_array = initial_match_array;
1511 int i, ret, map_len, match;
1512 u32 list_size, new_size;
1517 cells_name = kasprintf(GFP_KERNEL, "#%s-cells", stem_name);
1522 map_name = kasprintf(GFP_KERNEL, "%s-map", stem_name);
1526 mask_name = kasprintf(GFP_KERNEL, "%s-map-mask", stem_name);
1530 pass_name = kasprintf(GFP_KERNEL, "%s-map-pass-thru", stem_name);
1534 ret = __of_parse_phandle_with_args(np, list_name, cells_name, 0, index,
1539 /* Get the #<list>-cells property */
1541 ret = of_property_read_u32(cur, cells_name, &list_size);
1545 /* Precalculate the match array - this simplifies match loop */
1546 for (i = 0; i < list_size; i++)
1547 initial_match_array[i] = cpu_to_be32(out_args->args[i]);
1551 /* Get the <list>-map property */
1552 map = of_get_property(cur, map_name, &map_len);
1557 map_len /= sizeof(u32);
1559 /* Get the <list>-map-mask property (optional) */
1560 mask = of_get_property(cur, mask_name, NULL);
1563 /* Iterate through <list>-map property */
1565 while (map_len > (list_size + 1) && !match) {
1566 /* Compare specifiers */
1568 for (i = 0; i < list_size; i++, map_len--)
1569 match &= !((match_array[i] ^ *map++) & mask[i]);
1572 new = of_find_node_by_phandle(be32_to_cpup(map));
1576 /* Check if not found */
1580 if (!of_device_is_available(new))
1583 ret = of_property_read_u32(new, cells_name, &new_size);
1587 /* Check for malformed properties */
1588 if (WARN_ON(new_size > MAX_PHANDLE_ARGS))
1590 if (map_len < new_size)
1593 /* Move forward by new node's #<list>-cells amount */
1595 map_len -= new_size;
1600 /* Get the <list>-map-pass-thru property (optional) */
1601 pass = of_get_property(cur, pass_name, NULL);
1606 * Successfully parsed a <list>-map translation; copy new
1607 * specifier into the out_args structure, keeping the
1608 * bits specified in <list>-map-pass-thru.
1610 match_array = map - new_size;
1611 for (i = 0; i < new_size; i++) {
1612 __be32 val = *(map - new_size + i);
1614 if (i < list_size) {
1616 val |= cpu_to_be32(out_args->args[i]) & pass[i];
1619 out_args->args[i] = be32_to_cpu(val);
1621 out_args->args_count = list_size = new_size;
1622 /* Iterate again with new provider */
1638 EXPORT_SYMBOL(of_parse_phandle_with_args_map);
1641 * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
1642 * @np: pointer to a device tree node containing a list
1643 * @list_name: property name that contains a list
1644 * @cell_count: number of argument cells following the phandle
1645 * @index: index of a phandle to parse out
1646 * @out_args: optional pointer to output arguments structure (will be filled)
1648 * This function is useful to parse lists of phandles and their arguments.
1649 * Returns 0 on success and fills out_args, on error returns appropriate
1652 * Caller is responsible to call of_node_put() on the returned out_args->np
1664 * list = <&phandle1 0 2 &phandle2 2 3>;
1667 * To get a device_node of the `node2' node you may call this:
1668 * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
1670 int of_parse_phandle_with_fixed_args(const struct device_node *np,
1671 const char *list_name, int cell_count,
1672 int index, struct of_phandle_args *out_args)
1676 return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
1679 EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);
1682 * of_count_phandle_with_args() - Find the number of phandles references in a property
1683 * @np: pointer to a device tree node containing a list
1684 * @list_name: property name that contains a list
1685 * @cells_name: property name that specifies phandles' arguments count
1687 * Returns the number of phandle + argument tuples within a property. It
1688 * is a typical pattern to encode a list of phandle and variable
1689 * arguments into a single property. The number of arguments is encoded
1690 * by a property in the phandle-target node. For example, a gpios
1691 * property would contain a list of GPIO specifies consisting of a
1692 * phandle and 1 or more arguments. The number of arguments are
1693 * determined by the #gpio-cells property in the node pointed to by the
1696 int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1697 const char *cells_name)
1699 struct of_phandle_iterator it;
1700 int rc, cur_index = 0;
1702 rc = of_phandle_iterator_init(&it, np, list_name, cells_name, 0);
1706 while ((rc = of_phandle_iterator_next(&it)) == 0)
1714 EXPORT_SYMBOL(of_count_phandle_with_args);
1717 * __of_add_property - Add a property to a node without lock operations
1719 int __of_add_property(struct device_node *np, struct property *prop)
1721 struct property **next;
1724 next = &np->properties;
1726 if (strcmp(prop->name, (*next)->name) == 0)
1727 /* duplicate ! don't insert it */
1730 next = &(*next)->next;
1738 * of_add_property - Add a property to a node
1740 int of_add_property(struct device_node *np, struct property *prop)
1742 unsigned long flags;
1745 mutex_lock(&of_mutex);
1747 raw_spin_lock_irqsave(&devtree_lock, flags);
1748 rc = __of_add_property(np, prop);
1749 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1752 __of_add_property_sysfs(np, prop);
1754 mutex_unlock(&of_mutex);
1757 of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
1762 int __of_remove_property(struct device_node *np, struct property *prop)
1764 struct property **next;
1766 for (next = &np->properties; *next; next = &(*next)->next) {
1773 /* found the node */
1775 prop->next = np->deadprops;
1776 np->deadprops = prop;
1782 * of_remove_property - Remove a property from a node.
1784 * Note that we don't actually remove it, since we have given out
1785 * who-knows-how-many pointers to the data using get-property.
1786 * Instead we just move the property to the "dead properties"
1787 * list, so it won't be found any more.
1789 int of_remove_property(struct device_node *np, struct property *prop)
1791 unsigned long flags;
1797 mutex_lock(&of_mutex);
1799 raw_spin_lock_irqsave(&devtree_lock, flags);
1800 rc = __of_remove_property(np, prop);
1801 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1804 __of_remove_property_sysfs(np, prop);
1806 mutex_unlock(&of_mutex);
1809 of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
1814 int __of_update_property(struct device_node *np, struct property *newprop,
1815 struct property **oldpropp)
1817 struct property **next, *oldprop;
1819 for (next = &np->properties; *next; next = &(*next)->next) {
1820 if (of_prop_cmp((*next)->name, newprop->name) == 0)
1823 *oldpropp = oldprop = *next;
1826 /* replace the node */
1827 newprop->next = oldprop->next;
1829 oldprop->next = np->deadprops;
1830 np->deadprops = oldprop;
1833 newprop->next = NULL;
1841 * of_update_property - Update a property in a node, if the property does
1842 * not exist, add it.
1844 * Note that we don't actually remove it, since we have given out
1845 * who-knows-how-many pointers to the data using get-property.
1846 * Instead we just move the property to the "dead properties" list,
1847 * and add the new property to the property list
1849 int of_update_property(struct device_node *np, struct property *newprop)
1851 struct property *oldprop;
1852 unsigned long flags;
1858 mutex_lock(&of_mutex);
1860 raw_spin_lock_irqsave(&devtree_lock, flags);
1861 rc = __of_update_property(np, newprop, &oldprop);
1862 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1865 __of_update_property_sysfs(np, newprop, oldprop);
1867 mutex_unlock(&of_mutex);
1870 of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
1875 static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1876 int id, const char *stem, int stem_len)
1880 strncpy(ap->stem, stem, stem_len);
1881 ap->stem[stem_len] = 0;
1882 list_add_tail(&ap->link, &aliases_lookup);
1883 pr_debug("adding DT alias:%s: stem=%s id=%i node=%pOF\n",
1884 ap->alias, ap->stem, ap->id, np);
1888 * of_alias_scan - Scan all properties of the 'aliases' node
1890 * The function scans all the properties of the 'aliases' node and populates
1891 * the global lookup table with the properties. It returns the
1892 * number of alias properties found, or an error code in case of failure.
1894 * @dt_alloc: An allocator that provides a virtual address to memory
1895 * for storing the resulting tree
1897 void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1899 struct property *pp;
1901 of_aliases = of_find_node_by_path("/aliases");
1902 of_chosen = of_find_node_by_path("/chosen");
1903 if (of_chosen == NULL)
1904 of_chosen = of_find_node_by_path("/chosen@0");
1907 /* linux,stdout-path and /aliases/stdout are for legacy compatibility */
1908 const char *name = NULL;
1910 if (of_property_read_string(of_chosen, "stdout-path", &name))
1911 of_property_read_string(of_chosen, "linux,stdout-path",
1913 if (IS_ENABLED(CONFIG_PPC) && !name)
1914 of_property_read_string(of_aliases, "stdout", &name);
1916 of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
1922 for_each_property_of_node(of_aliases, pp) {
1923 const char *start = pp->name;
1924 const char *end = start + strlen(start);
1925 struct device_node *np;
1926 struct alias_prop *ap;
1929 /* Skip those we do not want to proceed */
1930 if (!strcmp(pp->name, "name") ||
1931 !strcmp(pp->name, "phandle") ||
1932 !strcmp(pp->name, "linux,phandle"))
1935 np = of_find_node_by_path(pp->value);
1939 /* walk the alias backwards to extract the id and work out
1940 * the 'stem' string */
1941 while (isdigit(*(end-1)) && end > start)
1945 if (kstrtoint(end, 10, &id) < 0)
1948 /* Allocate an alias_prop with enough space for the stem */
1949 ap = dt_alloc(sizeof(*ap) + len + 1, __alignof__(*ap));
1952 memset(ap, 0, sizeof(*ap) + len + 1);
1954 of_alias_add(ap, np, id, start, len);
1959 * of_alias_get_id - Get alias id for the given device_node
1960 * @np: Pointer to the given device_node
1961 * @stem: Alias stem of the given device_node
1963 * The function travels the lookup table to get the alias id for the given
1964 * device_node and alias stem. It returns the alias id if found.
1966 int of_alias_get_id(struct device_node *np, const char *stem)
1968 struct alias_prop *app;
1971 mutex_lock(&of_mutex);
1972 list_for_each_entry(app, &aliases_lookup, link) {
1973 if (strcmp(app->stem, stem) != 0)
1976 if (np == app->np) {
1981 mutex_unlock(&of_mutex);
1985 EXPORT_SYMBOL_GPL(of_alias_get_id);
1988 * of_alias_get_alias_list - Get alias list for the given device driver
1989 * @matches: Array of OF device match structures to search in
1990 * @stem: Alias stem of the given device_node
1991 * @bitmap: Bitmap field pointer
1992 * @nbits: Maximum number of alias IDs which can be recorded in bitmap
1994 * The function travels the lookup table to record alias ids for the given
1995 * device match structures and alias stem.
1997 * Return: 0 or -ENOSYS when !CONFIG_OF or
1998 * -EOVERFLOW if alias ID is greater then allocated nbits
2000 int of_alias_get_alias_list(const struct of_device_id *matches,
2001 const char *stem, unsigned long *bitmap,
2004 struct alias_prop *app;
2007 /* Zero bitmap field to make sure that all the time it is clean */
2008 bitmap_zero(bitmap, nbits);
2010 mutex_lock(&of_mutex);
2011 pr_debug("%s: Looking for stem: %s\n", __func__, stem);
2012 list_for_each_entry(app, &aliases_lookup, link) {
2013 pr_debug("%s: stem: %s, id: %d\n",
2014 __func__, app->stem, app->id);
2016 if (strcmp(app->stem, stem) != 0) {
2017 pr_debug("%s: stem comparison didn't pass %s\n",
2018 __func__, app->stem);
2022 if (of_match_node(matches, app->np)) {
2023 pr_debug("%s: Allocated ID %d\n", __func__, app->id);
2025 if (app->id >= nbits) {
2026 pr_warn("%s: ID %d >= than bitmap field %d\n",
2027 __func__, app->id, nbits);
2030 set_bit(app->id, bitmap);
2034 mutex_unlock(&of_mutex);
2038 EXPORT_SYMBOL_GPL(of_alias_get_alias_list);
2041 * of_alias_get_highest_id - Get highest alias id for the given stem
2042 * @stem: Alias stem to be examined
2044 * The function travels the lookup table to get the highest alias id for the
2045 * given alias stem. It returns the alias id if found.
2047 int of_alias_get_highest_id(const char *stem)
2049 struct alias_prop *app;
2052 mutex_lock(&of_mutex);
2053 list_for_each_entry(app, &aliases_lookup, link) {
2054 if (strcmp(app->stem, stem) != 0)
2060 mutex_unlock(&of_mutex);
2064 EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
2067 * of_console_check() - Test and setup console for DT setup
2068 * @dn - Pointer to device node
2069 * @name - Name to use for preferred console without index. ex. "ttyS"
2070 * @index - Index to use for preferred console.
2072 * Check if the given device node matches the stdout-path property in the
2073 * /chosen node. If it does then register it as the preferred console and return
2074 * TRUE. Otherwise return FALSE.
2076 bool of_console_check(struct device_node *dn, char *name, int index)
2078 if (!dn || dn != of_stdout || console_set_on_cmdline)
2082 * XXX: cast `options' to char pointer to suppress complication
2083 * warnings: printk, UART and console drivers expect char pointer.
2085 return !add_preferred_console(name, index, (char *)of_stdout_options);
2087 EXPORT_SYMBOL_GPL(of_console_check);
2090 * of_find_next_cache_node - Find a node's subsidiary cache
2091 * @np: node of type "cpu" or "cache"
2093 * Returns a node pointer with refcount incremented, use
2094 * of_node_put() on it when done. Caller should hold a reference
2097 struct device_node *of_find_next_cache_node(const struct device_node *np)
2099 struct device_node *child, *cache_node;
2101 cache_node = of_parse_phandle(np, "l2-cache", 0);
2103 cache_node = of_parse_phandle(np, "next-level-cache", 0);
2108 /* OF on pmac has nodes instead of properties named "l2-cache"
2109 * beneath CPU nodes.
2111 if (IS_ENABLED(CONFIG_PPC_PMAC) && !strcmp(np->type, "cpu"))
2112 for_each_child_of_node(np, child)
2113 if (!strcmp(child->type, "cache"))
2120 * of_find_last_cache_level - Find the level at which the last cache is
2121 * present for the given logical cpu
2123 * @cpu: cpu number(logical index) for which the last cache level is needed
2125 * Returns the the level at which the last cache is present. It is exactly
2126 * same as the total number of cache levels for the given logical cpu.
2128 int of_find_last_cache_level(unsigned int cpu)
2130 u32 cache_level = 0;
2131 struct device_node *prev = NULL, *np = of_cpu_device_node_get(cpu);
2136 np = of_find_next_cache_node(np);
2139 of_property_read_u32(prev, "cache-level", &cache_level);
2145 * of_map_rid - Translate a requester ID through a downstream mapping.
2146 * @np: root complex device node.
2147 * @rid: device requester ID to map.
2148 * @map_name: property name of the map to use.
2149 * @map_mask_name: optional property name of the mask to use.
2150 * @target: optional pointer to a target device node.
2151 * @id_out: optional pointer to receive the translated ID.
2153 * Given a device requester ID, look up the appropriate implementation-defined
2154 * platform ID and/or the target device which receives transactions on that
2155 * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
2156 * @id_out may be NULL if only the other is required. If @target points to
2157 * a non-NULL device node pointer, only entries targeting that node will be
2158 * matched; if it points to a NULL value, it will receive the device node of
2159 * the first matching target phandle, with a reference held.
2161 * Return: 0 on success or a standard error code on failure.
2163 int of_map_rid(struct device_node *np, u32 rid,
2164 const char *map_name, const char *map_mask_name,
2165 struct device_node **target, u32 *id_out)
2167 u32 map_mask, masked_rid;
2169 const __be32 *map = NULL;
2171 if (!np || !map_name || (!target && !id_out))
2174 map = of_get_property(np, map_name, &map_len);
2178 /* Otherwise, no map implies no translation */
2183 if (!map_len || map_len % (4 * sizeof(*map))) {
2184 pr_err("%pOF: Error: Bad %s length: %d\n", np,
2189 /* The default is to select all bits. */
2190 map_mask = 0xffffffff;
2193 * Can be overridden by "{iommu,msi}-map-mask" property.
2194 * If of_property_read_u32() fails, the default is used.
2197 of_property_read_u32(np, map_mask_name, &map_mask);
2199 masked_rid = map_mask & rid;
2200 for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
2201 struct device_node *phandle_node;
2202 u32 rid_base = be32_to_cpup(map + 0);
2203 u32 phandle = be32_to_cpup(map + 1);
2204 u32 out_base = be32_to_cpup(map + 2);
2205 u32 rid_len = be32_to_cpup(map + 3);
2207 if (rid_base & ~map_mask) {
2208 pr_err("%pOF: Invalid %s translation - %s-mask (0x%x) ignores rid-base (0x%x)\n",
2209 np, map_name, map_name,
2210 map_mask, rid_base);
2214 if (masked_rid < rid_base || masked_rid >= rid_base + rid_len)
2217 phandle_node = of_find_node_by_phandle(phandle);
2223 of_node_put(phandle_node);
2225 *target = phandle_node;
2227 if (*target != phandle_node)
2232 *id_out = masked_rid - rid_base + out_base;
2234 pr_debug("%pOF: %s, using mask %08x, rid-base: %08x, out-base: %08x, length: %08x, rid: %08x -> %08x\n",
2235 np, map_name, map_mask, rid_base, out_base,
2236 rid_len, rid, masked_rid - rid_base + out_base);
2240 pr_err("%pOF: Invalid %s translation - no match for rid 0x%x on %pOF\n",
2241 np, map_name, rid, target && *target ? *target : NULL);
2244 EXPORT_SYMBOL_GPL(of_map_rid);