2 * Procedures for creating, accessing and interpreting the device tree.
4 * Paul Mackerras August 1996.
5 * Copyright (C) 1996-2005 Paul Mackerras.
7 * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
8 * {engebret|bergner}@us.ibm.com
10 * Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
12 * Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License
17 * as published by the Free Software Foundation; either version
18 * 2 of the License, or (at your option) any later version.
21 #define pr_fmt(fmt) "OF: " fmt
23 #include <linux/console.h>
24 #include <linux/ctype.h>
25 #include <linux/cpu.h>
26 #include <linux/module.h>
28 #include <linux/of_device.h>
29 #include <linux/of_graph.h>
30 #include <linux/spinlock.h>
31 #include <linux/slab.h>
32 #include <linux/string.h>
33 #include <linux/proc_fs.h>
35 #include "of_private.h"
37 LIST_HEAD(aliases_lookup
);
39 struct device_node
*of_root
;
40 EXPORT_SYMBOL(of_root
);
41 struct device_node
*of_chosen
;
42 struct device_node
*of_aliases
;
43 struct device_node
*of_stdout
;
44 static const char *of_stdout_options
;
49 * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
50 * This mutex must be held whenever modifications are being made to the
51 * device tree. The of_{attach,detach}_node() and
52 * of_{add,remove,update}_property() helpers make sure this happens.
54 DEFINE_MUTEX(of_mutex
);
56 /* use when traversing tree through the child, sibling,
57 * or parent members of struct device_node.
59 DEFINE_RAW_SPINLOCK(devtree_lock
);
61 int of_n_addr_cells(struct device_node
*np
)
68 ip
= of_get_property(np
, "#address-cells", NULL
);
70 return be32_to_cpup(ip
);
72 /* No #address-cells property for the root node */
73 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT
;
75 EXPORT_SYMBOL(of_n_addr_cells
);
77 int of_n_size_cells(struct device_node
*np
)
84 ip
= of_get_property(np
, "#size-cells", NULL
);
86 return be32_to_cpup(ip
);
88 /* No #size-cells property for the root node */
89 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT
;
91 EXPORT_SYMBOL(of_n_size_cells
);
94 int __weak
of_node_to_nid(struct device_node
*np
)
100 #ifndef CONFIG_OF_DYNAMIC
101 static void of_node_release(struct kobject
*kobj
)
103 /* Without CONFIG_OF_DYNAMIC, no nodes gets freed */
105 #endif /* CONFIG_OF_DYNAMIC */
107 struct kobj_type of_node_ktype
= {
108 .release
= of_node_release
,
111 static ssize_t
of_node_property_read(struct file
*filp
, struct kobject
*kobj
,
112 struct bin_attribute
*bin_attr
, char *buf
,
113 loff_t offset
, size_t count
)
115 struct property
*pp
= container_of(bin_attr
, struct property
, attr
);
116 return memory_read_from_buffer(buf
, count
, &offset
, pp
->value
, pp
->length
);
119 /* always return newly allocated name, caller must free after use */
120 static const char *safe_name(struct kobject
*kobj
, const char *orig_name
)
122 const char *name
= orig_name
;
123 struct kernfs_node
*kn
;
126 /* don't be a hero. After 16 tries give up */
127 while (i
< 16 && (kn
= sysfs_get_dirent(kobj
->sd
, name
))) {
129 if (name
!= orig_name
)
131 name
= kasprintf(GFP_KERNEL
, "%s#%i", orig_name
, ++i
);
134 if (name
== orig_name
) {
135 name
= kstrdup(orig_name
, GFP_KERNEL
);
137 pr_warn("Duplicate name in %s, renamed to \"%s\"\n",
138 kobject_name(kobj
), name
);
143 int __of_add_property_sysfs(struct device_node
*np
, struct property
*pp
)
147 /* Important: Don't leak passwords */
148 bool secure
= strncmp(pp
->name
, "security-", 9) == 0;
150 if (!IS_ENABLED(CONFIG_SYSFS
))
153 if (!of_kset
|| !of_node_is_attached(np
))
156 sysfs_bin_attr_init(&pp
->attr
);
157 pp
->attr
.attr
.name
= safe_name(&np
->kobj
, pp
->name
);
158 pp
->attr
.attr
.mode
= secure
? S_IRUSR
: S_IRUGO
;
159 pp
->attr
.size
= secure
? 0 : pp
->length
;
160 pp
->attr
.read
= of_node_property_read
;
162 rc
= sysfs_create_bin_file(&np
->kobj
, &pp
->attr
);
163 WARN(rc
, "error adding attribute %s to node %s\n", pp
->name
, np
->full_name
);
167 int __of_attach_node_sysfs(struct device_node
*np
)
170 struct kobject
*parent
;
174 if (!IS_ENABLED(CONFIG_SYSFS
))
180 np
->kobj
.kset
= of_kset
;
182 /* Nodes without parents are new top level trees */
183 name
= safe_name(&of_kset
->kobj
, "base");
186 name
= safe_name(&np
->parent
->kobj
, kbasename(np
->full_name
));
187 parent
= &np
->parent
->kobj
;
191 rc
= kobject_add(&np
->kobj
, parent
, "%s", name
);
196 for_each_property_of_node(np
, pp
)
197 __of_add_property_sysfs(np
, pp
);
202 void __init
of_core_init(void)
204 struct device_node
*np
;
206 /* Create the kset, and register existing nodes */
207 mutex_lock(&of_mutex
);
208 of_kset
= kset_create_and_add("devicetree", NULL
, firmware_kobj
);
210 mutex_unlock(&of_mutex
);
211 pr_err("failed to register existing nodes\n");
214 for_each_of_allnodes(np
)
215 __of_attach_node_sysfs(np
);
216 mutex_unlock(&of_mutex
);
218 /* Symlink in /proc as required by userspace ABI */
220 proc_symlink("device-tree", NULL
, "/sys/firmware/devicetree/base");
223 static struct property
*__of_find_property(const struct device_node
*np
,
224 const char *name
, int *lenp
)
231 for (pp
= np
->properties
; pp
; pp
= pp
->next
) {
232 if (of_prop_cmp(pp
->name
, name
) == 0) {
242 struct property
*of_find_property(const struct device_node
*np
,
249 raw_spin_lock_irqsave(&devtree_lock
, flags
);
250 pp
= __of_find_property(np
, name
, lenp
);
251 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
255 EXPORT_SYMBOL(of_find_property
);
257 struct device_node
*__of_find_all_nodes(struct device_node
*prev
)
259 struct device_node
*np
;
262 } else if (prev
->child
) {
265 /* Walk back up looking for a sibling, or the end of the structure */
267 while (np
->parent
&& !np
->sibling
)
269 np
= np
->sibling
; /* Might be null at the end of the tree */
275 * of_find_all_nodes - Get next node in global list
276 * @prev: Previous node or NULL to start iteration
277 * of_node_put() will be called on it
279 * Returns a node pointer with refcount incremented, use
280 * of_node_put() on it when done.
282 struct device_node
*of_find_all_nodes(struct device_node
*prev
)
284 struct device_node
*np
;
287 raw_spin_lock_irqsave(&devtree_lock
, flags
);
288 np
= __of_find_all_nodes(prev
);
291 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
294 EXPORT_SYMBOL(of_find_all_nodes
);
297 * Find a property with a given name for a given node
298 * and return the value.
300 const void *__of_get_property(const struct device_node
*np
,
301 const char *name
, int *lenp
)
303 struct property
*pp
= __of_find_property(np
, name
, lenp
);
305 return pp
? pp
->value
: NULL
;
309 * Find a property with a given name for a given node
310 * and return the value.
312 const void *of_get_property(const struct device_node
*np
, const char *name
,
315 struct property
*pp
= of_find_property(np
, name
, lenp
);
317 return pp
? pp
->value
: NULL
;
319 EXPORT_SYMBOL(of_get_property
);
322 * arch_match_cpu_phys_id - Match the given logical CPU and physical id
324 * @cpu: logical cpu index of a core/thread
325 * @phys_id: physical identifier of a core/thread
327 * CPU logical to physical index mapping is architecture specific.
328 * However this __weak function provides a default match of physical
329 * id to logical cpu index. phys_id provided here is usually values read
330 * from the device tree which must match the hardware internal registers.
332 * Returns true if the physical identifier and the logical cpu index
333 * correspond to the same core/thread, false otherwise.
335 bool __weak
arch_match_cpu_phys_id(int cpu
, u64 phys_id
)
337 return (u32
)phys_id
== cpu
;
341 * Checks if the given "prop_name" property holds the physical id of the
342 * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
343 * NULL, local thread number within the core is returned in it.
345 static bool __of_find_n_match_cpu_property(struct device_node
*cpun
,
346 const char *prop_name
, int cpu
, unsigned int *thread
)
349 int ac
, prop_len
, tid
;
352 ac
= of_n_addr_cells(cpun
);
353 cell
= of_get_property(cpun
, prop_name
, &prop_len
);
356 prop_len
/= sizeof(*cell
) * ac
;
357 for (tid
= 0; tid
< prop_len
; tid
++) {
358 hwid
= of_read_number(cell
, ac
);
359 if (arch_match_cpu_phys_id(cpu
, hwid
)) {
370 * arch_find_n_match_cpu_physical_id - See if the given device node is
371 * for the cpu corresponding to logical cpu 'cpu'. Return true if so,
372 * else false. If 'thread' is non-NULL, the local thread number within the
373 * core is returned in it.
375 bool __weak
arch_find_n_match_cpu_physical_id(struct device_node
*cpun
,
376 int cpu
, unsigned int *thread
)
378 /* Check for non-standard "ibm,ppc-interrupt-server#s" property
379 * for thread ids on PowerPC. If it doesn't exist fallback to
380 * standard "reg" property.
382 if (IS_ENABLED(CONFIG_PPC
) &&
383 __of_find_n_match_cpu_property(cpun
,
384 "ibm,ppc-interrupt-server#s",
388 return __of_find_n_match_cpu_property(cpun
, "reg", cpu
, thread
);
392 * of_get_cpu_node - Get device node associated with the given logical CPU
394 * @cpu: CPU number(logical index) for which device node is required
395 * @thread: if not NULL, local thread number within the physical core is
398 * The main purpose of this function is to retrieve the device node for the
399 * given logical CPU index. It should be used to initialize the of_node in
400 * cpu device. Once of_node in cpu device is populated, all the further
401 * references can use that instead.
403 * CPU logical to physical index mapping is architecture specific and is built
404 * before booting secondary cores. This function uses arch_match_cpu_phys_id
405 * which can be overridden by architecture specific implementation.
407 * Returns a node pointer for the logical cpu with refcount incremented, use
408 * of_node_put() on it when done. Returns NULL if not found.
410 struct device_node
*of_get_cpu_node(int cpu
, unsigned int *thread
)
412 struct device_node
*cpun
;
414 for_each_node_by_type(cpun
, "cpu") {
415 if (arch_find_n_match_cpu_physical_id(cpun
, cpu
, thread
))
420 EXPORT_SYMBOL(of_get_cpu_node
);
423 * __of_device_is_compatible() - Check if the node matches given constraints
424 * @device: pointer to node
425 * @compat: required compatible string, NULL or "" for any match
426 * @type: required device_type value, NULL or "" for any match
427 * @name: required node name, NULL or "" for any match
429 * Checks if the given @compat, @type and @name strings match the
430 * properties of the given @device. A constraints can be skipped by
431 * passing NULL or an empty string as the constraint.
433 * Returns 0 for no match, and a positive integer on match. The return
434 * value is a relative score with larger values indicating better
435 * matches. The score is weighted for the most specific compatible value
436 * to get the highest score. Matching type is next, followed by matching
437 * name. Practically speaking, this results in the following priority
440 * 1. specific compatible && type && name
441 * 2. specific compatible && type
442 * 3. specific compatible && name
443 * 4. specific compatible
444 * 5. general compatible && type && name
445 * 6. general compatible && type
446 * 7. general compatible && name
447 * 8. general compatible
452 static int __of_device_is_compatible(const struct device_node
*device
,
453 const char *compat
, const char *type
, const char *name
)
455 struct property
*prop
;
457 int index
= 0, score
= 0;
459 /* Compatible match has highest priority */
460 if (compat
&& compat
[0]) {
461 prop
= __of_find_property(device
, "compatible", NULL
);
462 for (cp
= of_prop_next_string(prop
, NULL
); cp
;
463 cp
= of_prop_next_string(prop
, cp
), index
++) {
464 if (of_compat_cmp(cp
, compat
, strlen(compat
)) == 0) {
465 score
= INT_MAX
/2 - (index
<< 2);
473 /* Matching type is better than matching name */
474 if (type
&& type
[0]) {
475 if (!device
->type
|| of_node_cmp(type
, device
->type
))
480 /* Matching name is a bit better than not */
481 if (name
&& name
[0]) {
482 if (!device
->name
|| of_node_cmp(name
, device
->name
))
490 /** Checks if the given "compat" string matches one of the strings in
491 * the device's "compatible" property
493 int of_device_is_compatible(const struct device_node
*device
,
499 raw_spin_lock_irqsave(&devtree_lock
, flags
);
500 res
= __of_device_is_compatible(device
, compat
, NULL
, NULL
);
501 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
504 EXPORT_SYMBOL(of_device_is_compatible
);
506 /** Checks if the device is compatible with any of the entries in
507 * a NULL terminated array of strings. Returns the best match
510 int of_device_compatible_match(struct device_node
*device
,
511 const char *const *compat
)
513 unsigned int tmp
, score
= 0;
519 tmp
= of_device_is_compatible(device
, *compat
);
529 * of_machine_is_compatible - Test root of device tree for a given compatible value
530 * @compat: compatible string to look for in root node's compatible property.
532 * Returns a positive integer if the root node has the given value in its
533 * compatible property.
535 int of_machine_is_compatible(const char *compat
)
537 struct device_node
*root
;
540 root
= of_find_node_by_path("/");
542 rc
= of_device_is_compatible(root
, compat
);
547 EXPORT_SYMBOL(of_machine_is_compatible
);
550 * __of_device_is_available - check if a device is available for use
552 * @device: Node to check for availability, with locks already held
554 * Returns true if the status property is absent or set to "okay" or "ok",
557 static bool __of_device_is_available(const struct device_node
*device
)
565 status
= __of_get_property(device
, "status", &statlen
);
570 if (!strcmp(status
, "okay") || !strcmp(status
, "ok"))
578 * of_device_is_available - check if a device is available for use
580 * @device: Node to check for availability
582 * Returns true if the status property is absent or set to "okay" or "ok",
585 bool of_device_is_available(const struct device_node
*device
)
590 raw_spin_lock_irqsave(&devtree_lock
, flags
);
591 res
= __of_device_is_available(device
);
592 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
596 EXPORT_SYMBOL(of_device_is_available
);
599 * of_device_is_big_endian - check if a device has BE registers
601 * @device: Node to check for endianness
603 * Returns true if the device has a "big-endian" property, or if the kernel
604 * was compiled for BE *and* the device has a "native-endian" property.
605 * Returns false otherwise.
607 * Callers would nominally use ioread32be/iowrite32be if
608 * of_device_is_big_endian() == true, or readl/writel otherwise.
610 bool of_device_is_big_endian(const struct device_node
*device
)
612 if (of_property_read_bool(device
, "big-endian"))
614 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN
) &&
615 of_property_read_bool(device
, "native-endian"))
619 EXPORT_SYMBOL(of_device_is_big_endian
);
622 * of_get_parent - Get a node's parent if any
623 * @node: Node to get parent
625 * Returns a node pointer with refcount incremented, use
626 * of_node_put() on it when done.
628 struct device_node
*of_get_parent(const struct device_node
*node
)
630 struct device_node
*np
;
636 raw_spin_lock_irqsave(&devtree_lock
, flags
);
637 np
= of_node_get(node
->parent
);
638 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
641 EXPORT_SYMBOL(of_get_parent
);
644 * of_get_next_parent - Iterate to a node's parent
645 * @node: Node to get parent of
647 * This is like of_get_parent() except that it drops the
648 * refcount on the passed node, making it suitable for iterating
649 * through a node's parents.
651 * Returns a node pointer with refcount incremented, use
652 * of_node_put() on it when done.
654 struct device_node
*of_get_next_parent(struct device_node
*node
)
656 struct device_node
*parent
;
662 raw_spin_lock_irqsave(&devtree_lock
, flags
);
663 parent
= of_node_get(node
->parent
);
665 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
668 EXPORT_SYMBOL(of_get_next_parent
);
670 static struct device_node
*__of_get_next_child(const struct device_node
*node
,
671 struct device_node
*prev
)
673 struct device_node
*next
;
678 next
= prev
? prev
->sibling
: node
->child
;
679 for (; next
; next
= next
->sibling
)
680 if (of_node_get(next
))
685 #define __for_each_child_of_node(parent, child) \
686 for (child = __of_get_next_child(parent, NULL); child != NULL; \
687 child = __of_get_next_child(parent, child))
690 * of_get_next_child - Iterate a node childs
692 * @prev: previous child of the parent node, or NULL to get first
694 * Returns a node pointer with refcount incremented, use of_node_put() on
695 * it when done. Returns NULL when prev is the last child. Decrements the
698 struct device_node
*of_get_next_child(const struct device_node
*node
,
699 struct device_node
*prev
)
701 struct device_node
*next
;
704 raw_spin_lock_irqsave(&devtree_lock
, flags
);
705 next
= __of_get_next_child(node
, prev
);
706 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
709 EXPORT_SYMBOL(of_get_next_child
);
712 * of_get_next_available_child - Find the next available child node
714 * @prev: previous child of the parent node, or NULL to get first
716 * This function is like of_get_next_child(), except that it
717 * automatically skips any disabled nodes (i.e. status = "disabled").
719 struct device_node
*of_get_next_available_child(const struct device_node
*node
,
720 struct device_node
*prev
)
722 struct device_node
*next
;
728 raw_spin_lock_irqsave(&devtree_lock
, flags
);
729 next
= prev
? prev
->sibling
: node
->child
;
730 for (; next
; next
= next
->sibling
) {
731 if (!__of_device_is_available(next
))
733 if (of_node_get(next
))
737 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
740 EXPORT_SYMBOL(of_get_next_available_child
);
743 * of_get_child_by_name - Find the child node by name for a given parent
745 * @name: child name to look for.
747 * This function looks for child node for given matching name
749 * Returns a node pointer if found, with refcount incremented, use
750 * of_node_put() on it when done.
751 * Returns NULL if node is not found.
753 struct device_node
*of_get_child_by_name(const struct device_node
*node
,
756 struct device_node
*child
;
758 for_each_child_of_node(node
, child
)
759 if (child
->name
&& (of_node_cmp(child
->name
, name
) == 0))
763 EXPORT_SYMBOL(of_get_child_by_name
);
765 static struct device_node
*__of_find_node_by_path(struct device_node
*parent
,
768 struct device_node
*child
;
771 len
= strcspn(path
, "/:");
775 __for_each_child_of_node(parent
, child
) {
776 const char *name
= strrchr(child
->full_name
, '/');
777 if (WARN(!name
, "malformed device_node %s\n", child
->full_name
))
780 if (strncmp(path
, name
, len
) == 0 && (strlen(name
) == len
))
787 * of_find_node_opts_by_path - Find a node matching a full OF path
788 * @path: Either the full path to match, or if the path does not
789 * start with '/', the name of a property of the /aliases
790 * node (an alias). In the case of an alias, the node
791 * matching the alias' value will be returned.
792 * @opts: Address of a pointer into which to store the start of
793 * an options string appended to the end of the path with
799 * foo/bar Valid alias + relative path
801 * Returns a node pointer with refcount incremented, use
802 * of_node_put() on it when done.
804 struct device_node
*of_find_node_opts_by_path(const char *path
, const char **opts
)
806 struct device_node
*np
= NULL
;
809 const char *separator
= strchr(path
, ':');
812 *opts
= separator
? separator
+ 1 : NULL
;
814 if (strcmp(path
, "/") == 0)
815 return of_node_get(of_root
);
817 /* The path could begin with an alias */
820 const char *p
= separator
;
823 p
= strchrnul(path
, '/');
826 /* of_aliases must not be NULL */
830 for_each_property_of_node(of_aliases
, pp
) {
831 if (strlen(pp
->name
) == len
&& !strncmp(pp
->name
, path
, len
)) {
832 np
= of_find_node_by_path(pp
->value
);
841 /* Step down the tree matching path components */
842 raw_spin_lock_irqsave(&devtree_lock
, flags
);
844 np
= of_node_get(of_root
);
845 while (np
&& *path
== '/') {
846 struct device_node
*tmp
= np
;
848 path
++; /* Increment past '/' delimiter */
849 np
= __of_find_node_by_path(np
, path
);
851 path
= strchrnul(path
, '/');
852 if (separator
&& separator
< path
)
855 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
858 EXPORT_SYMBOL(of_find_node_opts_by_path
);
861 * of_find_node_by_name - Find a node by its "name" property
862 * @from: The node to start searching from or NULL, the node
863 * you pass will not be searched, only the next one
864 * will; typically, you pass what the previous call
865 * returned. of_node_put() will be called on it
866 * @name: The name string to match against
868 * Returns a node pointer with refcount incremented, use
869 * of_node_put() on it when done.
871 struct device_node
*of_find_node_by_name(struct device_node
*from
,
874 struct device_node
*np
;
877 raw_spin_lock_irqsave(&devtree_lock
, flags
);
878 for_each_of_allnodes_from(from
, np
)
879 if (np
->name
&& (of_node_cmp(np
->name
, name
) == 0)
883 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
886 EXPORT_SYMBOL(of_find_node_by_name
);
889 * of_find_node_by_type - Find a node by its "device_type" property
890 * @from: The node to start searching from, or NULL to start searching
891 * the entire device tree. The node you pass will not be
892 * searched, only the next one will; typically, you pass
893 * what the previous call returned. of_node_put() will be
894 * called on from for you.
895 * @type: The type string to match against
897 * Returns a node pointer with refcount incremented, use
898 * of_node_put() on it when done.
900 struct device_node
*of_find_node_by_type(struct device_node
*from
,
903 struct device_node
*np
;
906 raw_spin_lock_irqsave(&devtree_lock
, flags
);
907 for_each_of_allnodes_from(from
, np
)
908 if (np
->type
&& (of_node_cmp(np
->type
, type
) == 0)
912 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
915 EXPORT_SYMBOL(of_find_node_by_type
);
918 * of_find_compatible_node - Find a node based on type and one of the
919 * tokens in its "compatible" property
920 * @from: The node to start searching from or NULL, the node
921 * you pass will not be searched, only the next one
922 * will; typically, you pass what the previous call
923 * returned. of_node_put() will be called on it
924 * @type: The type string to match "device_type" or NULL to ignore
925 * @compatible: The string to match to one of the tokens in the device
928 * Returns a node pointer with refcount incremented, use
929 * of_node_put() on it when done.
931 struct device_node
*of_find_compatible_node(struct device_node
*from
,
932 const char *type
, const char *compatible
)
934 struct device_node
*np
;
937 raw_spin_lock_irqsave(&devtree_lock
, flags
);
938 for_each_of_allnodes_from(from
, np
)
939 if (__of_device_is_compatible(np
, compatible
, type
, NULL
) &&
943 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
946 EXPORT_SYMBOL(of_find_compatible_node
);
949 * of_find_node_with_property - Find a node which has a property with
951 * @from: The node to start searching from or NULL, the node
952 * you pass will not be searched, only the next one
953 * will; typically, you pass what the previous call
954 * returned. of_node_put() will be called on it
955 * @prop_name: The name of the property to look for.
957 * Returns a node pointer with refcount incremented, use
958 * of_node_put() on it when done.
960 struct device_node
*of_find_node_with_property(struct device_node
*from
,
961 const char *prop_name
)
963 struct device_node
*np
;
967 raw_spin_lock_irqsave(&devtree_lock
, flags
);
968 for_each_of_allnodes_from(from
, np
) {
969 for (pp
= np
->properties
; pp
; pp
= pp
->next
) {
970 if (of_prop_cmp(pp
->name
, prop_name
) == 0) {
978 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
981 EXPORT_SYMBOL(of_find_node_with_property
);
984 const struct of_device_id
*__of_match_node(const struct of_device_id
*matches
,
985 const struct device_node
*node
)
987 const struct of_device_id
*best_match
= NULL
;
988 int score
, best_score
= 0;
993 for (; matches
->name
[0] || matches
->type
[0] || matches
->compatible
[0]; matches
++) {
994 score
= __of_device_is_compatible(node
, matches
->compatible
,
995 matches
->type
, matches
->name
);
996 if (score
> best_score
) {
997 best_match
= matches
;
1006 * of_match_node - Tell if a device_node has a matching of_match structure
1007 * @matches: array of of device match structures to search in
1008 * @node: the of device structure to match against
1010 * Low level utility function used by device matching.
1012 const struct of_device_id
*of_match_node(const struct of_device_id
*matches
,
1013 const struct device_node
*node
)
1015 const struct of_device_id
*match
;
1016 unsigned long flags
;
1018 raw_spin_lock_irqsave(&devtree_lock
, flags
);
1019 match
= __of_match_node(matches
, node
);
1020 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
1023 EXPORT_SYMBOL(of_match_node
);
1026 * of_find_matching_node_and_match - Find a node based on an of_device_id
1028 * @from: The node to start searching from or NULL, the node
1029 * you pass will not be searched, only the next one
1030 * will; typically, you pass what the previous call
1031 * returned. of_node_put() will be called on it
1032 * @matches: array of of device match structures to search in
1033 * @match Updated to point at the matches entry which matched
1035 * Returns a node pointer with refcount incremented, use
1036 * of_node_put() on it when done.
1038 struct device_node
*of_find_matching_node_and_match(struct device_node
*from
,
1039 const struct of_device_id
*matches
,
1040 const struct of_device_id
**match
)
1042 struct device_node
*np
;
1043 const struct of_device_id
*m
;
1044 unsigned long flags
;
1049 raw_spin_lock_irqsave(&devtree_lock
, flags
);
1050 for_each_of_allnodes_from(from
, np
) {
1051 m
= __of_match_node(matches
, np
);
1052 if (m
&& of_node_get(np
)) {
1059 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
1062 EXPORT_SYMBOL(of_find_matching_node_and_match
);
1065 * of_modalias_node - Lookup appropriate modalias for a device node
1066 * @node: pointer to a device tree node
1067 * @modalias: Pointer to buffer that modalias value will be copied into
1068 * @len: Length of modalias value
1070 * Based on the value of the compatible property, this routine will attempt
1071 * to choose an appropriate modalias value for a particular device tree node.
1072 * It does this by stripping the manufacturer prefix (as delimited by a ',')
1073 * from the first entry in the compatible list property.
1075 * This routine returns 0 on success, <0 on failure.
1077 int of_modalias_node(struct device_node
*node
, char *modalias
, int len
)
1079 const char *compatible
, *p
;
1082 compatible
= of_get_property(node
, "compatible", &cplen
);
1083 if (!compatible
|| strlen(compatible
) > cplen
)
1085 p
= strchr(compatible
, ',');
1086 strlcpy(modalias
, p
? p
+ 1 : compatible
, len
);
1089 EXPORT_SYMBOL_GPL(of_modalias_node
);
1092 * of_find_node_by_phandle - Find a node given a phandle
1093 * @handle: phandle of the node to find
1095 * Returns a node pointer with refcount incremented, use
1096 * of_node_put() on it when done.
1098 struct device_node
*of_find_node_by_phandle(phandle handle
)
1100 struct device_node
*np
;
1101 unsigned long flags
;
1106 raw_spin_lock_irqsave(&devtree_lock
, flags
);
1107 for_each_of_allnodes(np
)
1108 if (np
->phandle
== handle
)
1111 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
1114 EXPORT_SYMBOL(of_find_node_by_phandle
);
1116 void of_print_phandle_args(const char *msg
, const struct of_phandle_args
*args
)
1119 printk("%s %s", msg
, of_node_full_name(args
->np
));
1120 for (i
= 0; i
< args
->args_count
; i
++) {
1121 const char delim
= i
? ',' : ':';
1123 pr_cont("%c%08x", delim
, args
->args
[i
]);
1128 int of_phandle_iterator_init(struct of_phandle_iterator
*it
,
1129 const struct device_node
*np
,
1130 const char *list_name
,
1131 const char *cells_name
,
1137 memset(it
, 0, sizeof(*it
));
1139 list
= of_get_property(np
, list_name
, &size
);
1143 it
->cells_name
= cells_name
;
1144 it
->cell_count
= cell_count
;
1146 it
->list_end
= list
+ size
/ sizeof(*list
);
1147 it
->phandle_end
= list
;
1153 int of_phandle_iterator_next(struct of_phandle_iterator
*it
)
1158 of_node_put(it
->node
);
1162 if (!it
->cur
|| it
->phandle_end
>= it
->list_end
)
1165 it
->cur
= it
->phandle_end
;
1167 /* If phandle is 0, then it is an empty entry with no arguments. */
1168 it
->phandle
= be32_to_cpup(it
->cur
++);
1173 * Find the provider node and parse the #*-cells property to
1174 * determine the argument length.
1176 it
->node
= of_find_node_by_phandle(it
->phandle
);
1178 if (it
->cells_name
) {
1180 pr_err("%s: could not find phandle\n",
1181 it
->parent
->full_name
);
1185 if (of_property_read_u32(it
->node
, it
->cells_name
,
1187 pr_err("%s: could not get %s for %s\n",
1188 it
->parent
->full_name
,
1190 it
->node
->full_name
);
1194 count
= it
->cell_count
;
1198 * Make sure that the arguments actually fit in the remaining
1199 * property data length
1201 if (it
->cur
+ count
> it
->list_end
) {
1202 pr_err("%s: arguments longer than property\n",
1203 it
->parent
->full_name
);
1208 it
->phandle_end
= it
->cur
+ count
;
1209 it
->cur_count
= count
;
1215 of_node_put(it
->node
);
1222 int of_phandle_iterator_args(struct of_phandle_iterator
*it
,
1228 count
= it
->cur_count
;
1230 if (WARN_ON(size
< count
))
1233 for (i
= 0; i
< count
; i
++)
1234 args
[i
] = be32_to_cpup(it
->cur
++);
1239 static int __of_parse_phandle_with_args(const struct device_node
*np
,
1240 const char *list_name
,
1241 const char *cells_name
,
1242 int cell_count
, int index
,
1243 struct of_phandle_args
*out_args
)
1245 struct of_phandle_iterator it
;
1246 int rc
, cur_index
= 0;
1248 /* Loop over the phandles until all the requested entry is found */
1249 of_for_each_phandle(&it
, rc
, np
, list_name
, cells_name
, cell_count
) {
1251 * All of the error cases bail out of the loop, so at
1252 * this point, the parsing is successful. If the requested
1253 * index matches, then fill the out_args structure and return,
1254 * or return -ENOENT for an empty entry.
1257 if (cur_index
== index
) {
1264 c
= of_phandle_iterator_args(&it
,
1267 out_args
->np
= it
.node
;
1268 out_args
->args_count
= c
;
1270 of_node_put(it
.node
);
1273 /* Found it! return success */
1281 * Unlock node before returning result; will be one of:
1282 * -ENOENT : index is for empty phandle
1283 * -EINVAL : parsing error on data
1287 of_node_put(it
.node
);
1292 * of_parse_phandle - Resolve a phandle property to a device_node pointer
1293 * @np: Pointer to device node holding phandle property
1294 * @phandle_name: Name of property holding a phandle value
1295 * @index: For properties holding a table of phandles, this is the index into
1298 * Returns the device_node pointer with refcount incremented. Use
1299 * of_node_put() on it when done.
1301 struct device_node
*of_parse_phandle(const struct device_node
*np
,
1302 const char *phandle_name
, int index
)
1304 struct of_phandle_args args
;
1309 if (__of_parse_phandle_with_args(np
, phandle_name
, NULL
, 0,
1315 EXPORT_SYMBOL(of_parse_phandle
);
1318 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
1319 * @np: pointer to a device tree node containing a list
1320 * @list_name: property name that contains a list
1321 * @cells_name: property name that specifies phandles' arguments count
1322 * @index: index of a phandle to parse out
1323 * @out_args: optional pointer to output arguments structure (will be filled)
1325 * This function is useful to parse lists of phandles and their arguments.
1326 * Returns 0 on success and fills out_args, on error returns appropriate
1329 * Caller is responsible to call of_node_put() on the returned out_args->np
1335 * #list-cells = <2>;
1339 * #list-cells = <1>;
1343 * list = <&phandle1 1 2 &phandle2 3>;
1346 * To get a device_node of the `node2' node you may call this:
1347 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
1349 int of_parse_phandle_with_args(const struct device_node
*np
, const char *list_name
,
1350 const char *cells_name
, int index
,
1351 struct of_phandle_args
*out_args
)
1355 return __of_parse_phandle_with_args(np
, list_name
, cells_name
, 0,
1358 EXPORT_SYMBOL(of_parse_phandle_with_args
);
1361 * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
1362 * @np: pointer to a device tree node containing a list
1363 * @list_name: property name that contains a list
1364 * @cell_count: number of argument cells following the phandle
1365 * @index: index of a phandle to parse out
1366 * @out_args: optional pointer to output arguments structure (will be filled)
1368 * This function is useful to parse lists of phandles and their arguments.
1369 * Returns 0 on success and fills out_args, on error returns appropriate
1372 * Caller is responsible to call of_node_put() on the returned out_args->np
1384 * list = <&phandle1 0 2 &phandle2 2 3>;
1387 * To get a device_node of the `node2' node you may call this:
1388 * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
1390 int of_parse_phandle_with_fixed_args(const struct device_node
*np
,
1391 const char *list_name
, int cell_count
,
1392 int index
, struct of_phandle_args
*out_args
)
1396 return __of_parse_phandle_with_args(np
, list_name
, NULL
, cell_count
,
1399 EXPORT_SYMBOL(of_parse_phandle_with_fixed_args
);
1402 * of_count_phandle_with_args() - Find the number of phandles references in a property
1403 * @np: pointer to a device tree node containing a list
1404 * @list_name: property name that contains a list
1405 * @cells_name: property name that specifies phandles' arguments count
1407 * Returns the number of phandle + argument tuples within a property. It
1408 * is a typical pattern to encode a list of phandle and variable
1409 * arguments into a single property. The number of arguments is encoded
1410 * by a property in the phandle-target node. For example, a gpios
1411 * property would contain a list of GPIO specifies consisting of a
1412 * phandle and 1 or more arguments. The number of arguments are
1413 * determined by the #gpio-cells property in the node pointed to by the
1416 int of_count_phandle_with_args(const struct device_node
*np
, const char *list_name
,
1417 const char *cells_name
)
1419 struct of_phandle_iterator it
;
1420 int rc
, cur_index
= 0;
1422 rc
= of_phandle_iterator_init(&it
, np
, list_name
, cells_name
, 0);
1426 while ((rc
= of_phandle_iterator_next(&it
)) == 0)
1434 EXPORT_SYMBOL(of_count_phandle_with_args
);
1437 * __of_add_property - Add a property to a node without lock operations
1439 int __of_add_property(struct device_node
*np
, struct property
*prop
)
1441 struct property
**next
;
1444 next
= &np
->properties
;
1446 if (strcmp(prop
->name
, (*next
)->name
) == 0)
1447 /* duplicate ! don't insert it */
1450 next
= &(*next
)->next
;
1458 * of_add_property - Add a property to a node
1460 int of_add_property(struct device_node
*np
, struct property
*prop
)
1462 unsigned long flags
;
1465 mutex_lock(&of_mutex
);
1467 raw_spin_lock_irqsave(&devtree_lock
, flags
);
1468 rc
= __of_add_property(np
, prop
);
1469 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
1472 __of_add_property_sysfs(np
, prop
);
1474 mutex_unlock(&of_mutex
);
1477 of_property_notify(OF_RECONFIG_ADD_PROPERTY
, np
, prop
, NULL
);
1482 int __of_remove_property(struct device_node
*np
, struct property
*prop
)
1484 struct property
**next
;
1486 for (next
= &np
->properties
; *next
; next
= &(*next
)->next
) {
1493 /* found the node */
1495 prop
->next
= np
->deadprops
;
1496 np
->deadprops
= prop
;
1501 void __of_sysfs_remove_bin_file(struct device_node
*np
, struct property
*prop
)
1503 sysfs_remove_bin_file(&np
->kobj
, &prop
->attr
);
1504 kfree(prop
->attr
.attr
.name
);
1507 void __of_remove_property_sysfs(struct device_node
*np
, struct property
*prop
)
1509 if (!IS_ENABLED(CONFIG_SYSFS
))
1512 /* at early boot, bail here and defer setup to of_init() */
1513 if (of_kset
&& of_node_is_attached(np
))
1514 __of_sysfs_remove_bin_file(np
, prop
);
1518 * of_remove_property - Remove a property from a node.
1520 * Note that we don't actually remove it, since we have given out
1521 * who-knows-how-many pointers to the data using get-property.
1522 * Instead we just move the property to the "dead properties"
1523 * list, so it won't be found any more.
1525 int of_remove_property(struct device_node
*np
, struct property
*prop
)
1527 unsigned long flags
;
1533 mutex_lock(&of_mutex
);
1535 raw_spin_lock_irqsave(&devtree_lock
, flags
);
1536 rc
= __of_remove_property(np
, prop
);
1537 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
1540 __of_remove_property_sysfs(np
, prop
);
1542 mutex_unlock(&of_mutex
);
1545 of_property_notify(OF_RECONFIG_REMOVE_PROPERTY
, np
, prop
, NULL
);
1550 int __of_update_property(struct device_node
*np
, struct property
*newprop
,
1551 struct property
**oldpropp
)
1553 struct property
**next
, *oldprop
;
1555 for (next
= &np
->properties
; *next
; next
= &(*next
)->next
) {
1556 if (of_prop_cmp((*next
)->name
, newprop
->name
) == 0)
1559 *oldpropp
= oldprop
= *next
;
1562 /* replace the node */
1563 newprop
->next
= oldprop
->next
;
1565 oldprop
->next
= np
->deadprops
;
1566 np
->deadprops
= oldprop
;
1569 newprop
->next
= NULL
;
1576 void __of_update_property_sysfs(struct device_node
*np
, struct property
*newprop
,
1577 struct property
*oldprop
)
1579 if (!IS_ENABLED(CONFIG_SYSFS
))
1582 /* At early boot, bail out and defer setup to of_init() */
1587 __of_sysfs_remove_bin_file(np
, oldprop
);
1588 __of_add_property_sysfs(np
, newprop
);
1592 * of_update_property - Update a property in a node, if the property does
1593 * not exist, add it.
1595 * Note that we don't actually remove it, since we have given out
1596 * who-knows-how-many pointers to the data using get-property.
1597 * Instead we just move the property to the "dead properties" list,
1598 * and add the new property to the property list
1600 int of_update_property(struct device_node
*np
, struct property
*newprop
)
1602 struct property
*oldprop
;
1603 unsigned long flags
;
1609 mutex_lock(&of_mutex
);
1611 raw_spin_lock_irqsave(&devtree_lock
, flags
);
1612 rc
= __of_update_property(np
, newprop
, &oldprop
);
1613 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
1616 __of_update_property_sysfs(np
, newprop
, oldprop
);
1618 mutex_unlock(&of_mutex
);
1621 of_property_notify(OF_RECONFIG_UPDATE_PROPERTY
, np
, newprop
, oldprop
);
1626 static void of_alias_add(struct alias_prop
*ap
, struct device_node
*np
,
1627 int id
, const char *stem
, int stem_len
)
1631 strncpy(ap
->stem
, stem
, stem_len
);
1632 ap
->stem
[stem_len
] = 0;
1633 list_add_tail(&ap
->link
, &aliases_lookup
);
1634 pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
1635 ap
->alias
, ap
->stem
, ap
->id
, of_node_full_name(np
));
1639 * of_alias_scan - Scan all properties of the 'aliases' node
1641 * The function scans all the properties of the 'aliases' node and populates
1642 * the global lookup table with the properties. It returns the
1643 * number of alias properties found, or an error code in case of failure.
1645 * @dt_alloc: An allocator that provides a virtual address to memory
1646 * for storing the resulting tree
1648 void of_alias_scan(void * (*dt_alloc
)(u64 size
, u64 align
))
1650 struct property
*pp
;
1652 of_aliases
= of_find_node_by_path("/aliases");
1653 of_chosen
= of_find_node_by_path("/chosen");
1654 if (of_chosen
== NULL
)
1655 of_chosen
= of_find_node_by_path("/chosen@0");
1658 /* linux,stdout-path and /aliases/stdout are for legacy compatibility */
1659 const char *name
= of_get_property(of_chosen
, "stdout-path", NULL
);
1661 name
= of_get_property(of_chosen
, "linux,stdout-path", NULL
);
1662 if (IS_ENABLED(CONFIG_PPC
) && !name
)
1663 name
= of_get_property(of_aliases
, "stdout", NULL
);
1665 of_stdout
= of_find_node_opts_by_path(name
, &of_stdout_options
);
1671 for_each_property_of_node(of_aliases
, pp
) {
1672 const char *start
= pp
->name
;
1673 const char *end
= start
+ strlen(start
);
1674 struct device_node
*np
;
1675 struct alias_prop
*ap
;
1678 /* Skip those we do not want to proceed */
1679 if (!strcmp(pp
->name
, "name") ||
1680 !strcmp(pp
->name
, "phandle") ||
1681 !strcmp(pp
->name
, "linux,phandle"))
1684 np
= of_find_node_by_path(pp
->value
);
1688 /* walk the alias backwards to extract the id and work out
1689 * the 'stem' string */
1690 while (isdigit(*(end
-1)) && end
> start
)
1694 if (kstrtoint(end
, 10, &id
) < 0)
1697 /* Allocate an alias_prop with enough space for the stem */
1698 ap
= dt_alloc(sizeof(*ap
) + len
+ 1, __alignof__(*ap
));
1701 memset(ap
, 0, sizeof(*ap
) + len
+ 1);
1703 of_alias_add(ap
, np
, id
, start
, len
);
1708 * of_alias_get_id - Get alias id for the given device_node
1709 * @np: Pointer to the given device_node
1710 * @stem: Alias stem of the given device_node
1712 * The function travels the lookup table to get the alias id for the given
1713 * device_node and alias stem. It returns the alias id if found.
1715 int of_alias_get_id(struct device_node
*np
, const char *stem
)
1717 struct alias_prop
*app
;
1720 mutex_lock(&of_mutex
);
1721 list_for_each_entry(app
, &aliases_lookup
, link
) {
1722 if (strcmp(app
->stem
, stem
) != 0)
1725 if (np
== app
->np
) {
1730 mutex_unlock(&of_mutex
);
1734 EXPORT_SYMBOL_GPL(of_alias_get_id
);
1737 * of_alias_get_highest_id - Get highest alias id for the given stem
1738 * @stem: Alias stem to be examined
1740 * The function travels the lookup table to get the highest alias id for the
1741 * given alias stem. It returns the alias id if found.
1743 int of_alias_get_highest_id(const char *stem
)
1745 struct alias_prop
*app
;
1748 mutex_lock(&of_mutex
);
1749 list_for_each_entry(app
, &aliases_lookup
, link
) {
1750 if (strcmp(app
->stem
, stem
) != 0)
1756 mutex_unlock(&of_mutex
);
1760 EXPORT_SYMBOL_GPL(of_alias_get_highest_id
);
1763 * of_console_check() - Test and setup console for DT setup
1764 * @dn - Pointer to device node
1765 * @name - Name to use for preferred console without index. ex. "ttyS"
1766 * @index - Index to use for preferred console.
1768 * Check if the given device node matches the stdout-path property in the
1769 * /chosen node. If it does then register it as the preferred console and return
1770 * TRUE. Otherwise return FALSE.
1772 bool of_console_check(struct device_node
*dn
, char *name
, int index
)
1774 if (!dn
|| dn
!= of_stdout
|| console_set_on_cmdline
)
1776 return !add_preferred_console(name
, index
,
1777 kstrdup(of_stdout_options
, GFP_KERNEL
));
1779 EXPORT_SYMBOL_GPL(of_console_check
);
1782 * of_find_next_cache_node - Find a node's subsidiary cache
1783 * @np: node of type "cpu" or "cache"
1785 * Returns a node pointer with refcount incremented, use
1786 * of_node_put() on it when done. Caller should hold a reference
1789 struct device_node
*of_find_next_cache_node(const struct device_node
*np
)
1791 struct device_node
*child
, *cache_node
;
1793 cache_node
= of_parse_phandle(np
, "l2-cache", 0);
1795 cache_node
= of_parse_phandle(np
, "next-level-cache", 0);
1800 /* OF on pmac has nodes instead of properties named "l2-cache"
1801 * beneath CPU nodes.
1803 if (!strcmp(np
->type
, "cpu"))
1804 for_each_child_of_node(np
, child
)
1805 if (!strcmp(child
->type
, "cache"))
1812 * of_find_last_cache_level - Find the level at which the last cache is
1813 * present for the given logical cpu
1815 * @cpu: cpu number(logical index) for which the last cache level is needed
1817 * Returns the the level at which the last cache is present. It is exactly
1818 * same as the total number of cache levels for the given logical cpu.
1820 int of_find_last_cache_level(unsigned int cpu
)
1822 u32 cache_level
= 0;
1823 struct device_node
*prev
= NULL
, *np
= of_cpu_device_node_get(cpu
);
1828 np
= of_find_next_cache_node(np
);
1831 of_property_read_u32(prev
, "cache-level", &cache_level
);