xref: /linux-6.15/include/linux/of.h (revision c819e2cf)
1 #ifndef _LINUX_OF_H
2 #define _LINUX_OF_H
3 /*
4  * Definitions for talking to the Open Firmware PROM on
5  * Power Macintosh and other computers.
6  *
7  * Copyright (C) 1996-2005 Paul Mackerras.
8  *
9  * Updates for PPC64 by Peter Bergner & David Engebretsen, IBM Corp.
10  * Updates for SPARC64 by David S. Miller
11  * Derived from PowerPC and Sparc prom.h files by Stephen Rothwell, IBM Corp.
12  *
13  * This program is free software; you can redistribute it and/or
14  * modify it under the terms of the GNU General Public License
15  * as published by the Free Software Foundation; either version
16  * 2 of the License, or (at your option) any later version.
17  */
18 #include <linux/types.h>
19 #include <linux/bitops.h>
20 #include <linux/errno.h>
21 #include <linux/kobject.h>
22 #include <linux/mod_devicetable.h>
23 #include <linux/spinlock.h>
24 #include <linux/topology.h>
25 #include <linux/notifier.h>
26 #include <linux/property.h>
27 #include <linux/list.h>
28 
29 #include <asm/byteorder.h>
30 #include <asm/errno.h>
31 
32 typedef u32 phandle;
33 typedef u32 ihandle;
34 
35 struct property {
36 	char	*name;
37 	int	length;
38 	void	*value;
39 	struct property *next;
40 	unsigned long _flags;
41 	unsigned int unique_id;
42 	struct bin_attribute attr;
43 };
44 
45 #if defined(CONFIG_SPARC)
46 struct of_irq_controller;
47 #endif
48 
49 struct device_node {
50 	const char *name;
51 	const char *type;
52 	phandle phandle;
53 	const char *full_name;
54 	struct fwnode_handle fwnode;
55 
56 	struct	property *properties;
57 	struct	property *deadprops;	/* removed properties */
58 	struct	device_node *parent;
59 	struct	device_node *child;
60 	struct	device_node *sibling;
61 	struct	kobject kobj;
62 	unsigned long _flags;
63 	void	*data;
64 #if defined(CONFIG_SPARC)
65 	const char *path_component_name;
66 	unsigned int unique_id;
67 	struct of_irq_controller *irq_trans;
68 #endif
69 };
70 
71 #define MAX_PHANDLE_ARGS 16
72 struct of_phandle_args {
73 	struct device_node *np;
74 	int args_count;
75 	uint32_t args[MAX_PHANDLE_ARGS];
76 };
77 
78 struct of_reconfig_data {
79 	struct device_node	*dn;
80 	struct property		*prop;
81 	struct property		*old_prop;
82 };
83 
84 /* initialize a node */
85 extern struct kobj_type of_node_ktype;
86 static inline void of_node_init(struct device_node *node)
87 {
88 	kobject_init(&node->kobj, &of_node_ktype);
89 	node->fwnode.type = FWNODE_OF;
90 }
91 
92 /* true when node is initialized */
93 static inline int of_node_is_initialized(struct device_node *node)
94 {
95 	return node && node->kobj.state_initialized;
96 }
97 
98 /* true when node is attached (i.e. present on sysfs) */
99 static inline int of_node_is_attached(struct device_node *node)
100 {
101 	return node && node->kobj.state_in_sysfs;
102 }
103 
104 #ifdef CONFIG_OF_DYNAMIC
105 extern struct device_node *of_node_get(struct device_node *node);
106 extern void of_node_put(struct device_node *node);
107 #else /* CONFIG_OF_DYNAMIC */
108 /* Dummy ref counting routines - to be implemented later */
109 static inline struct device_node *of_node_get(struct device_node *node)
110 {
111 	return node;
112 }
113 static inline void of_node_put(struct device_node *node) { }
114 #endif /* !CONFIG_OF_DYNAMIC */
115 
116 /* Pointer for first entry in chain of all nodes. */
117 extern struct device_node *of_root;
118 extern struct device_node *of_chosen;
119 extern struct device_node *of_aliases;
120 extern struct device_node *of_stdout;
121 extern raw_spinlock_t devtree_lock;
122 
123 #ifdef CONFIG_OF
124 static inline bool is_of_node(struct fwnode_handle *fwnode)
125 {
126 	return fwnode && fwnode->type == FWNODE_OF;
127 }
128 
129 static inline struct device_node *of_node(struct fwnode_handle *fwnode)
130 {
131 	return fwnode ? container_of(fwnode, struct device_node, fwnode) : NULL;
132 }
133 
134 static inline bool of_have_populated_dt(void)
135 {
136 	return of_root != NULL;
137 }
138 
139 static inline bool of_node_is_root(const struct device_node *node)
140 {
141 	return node && (node->parent == NULL);
142 }
143 
144 static inline int of_node_check_flag(struct device_node *n, unsigned long flag)
145 {
146 	return test_bit(flag, &n->_flags);
147 }
148 
149 static inline int of_node_test_and_set_flag(struct device_node *n,
150 					    unsigned long flag)
151 {
152 	return test_and_set_bit(flag, &n->_flags);
153 }
154 
155 static inline void of_node_set_flag(struct device_node *n, unsigned long flag)
156 {
157 	set_bit(flag, &n->_flags);
158 }
159 
160 static inline void of_node_clear_flag(struct device_node *n, unsigned long flag)
161 {
162 	clear_bit(flag, &n->_flags);
163 }
164 
165 static inline int of_property_check_flag(struct property *p, unsigned long flag)
166 {
167 	return test_bit(flag, &p->_flags);
168 }
169 
170 static inline void of_property_set_flag(struct property *p, unsigned long flag)
171 {
172 	set_bit(flag, &p->_flags);
173 }
174 
175 static inline void of_property_clear_flag(struct property *p, unsigned long flag)
176 {
177 	clear_bit(flag, &p->_flags);
178 }
179 
180 extern struct device_node *__of_find_all_nodes(struct device_node *prev);
181 extern struct device_node *of_find_all_nodes(struct device_node *prev);
182 
183 /*
184  * OF address retrieval & translation
185  */
186 
187 /* Helper to read a big number; size is in cells (not bytes) */
188 static inline u64 of_read_number(const __be32 *cell, int size)
189 {
190 	u64 r = 0;
191 	while (size--)
192 		r = (r << 32) | be32_to_cpu(*(cell++));
193 	return r;
194 }
195 
196 /* Like of_read_number, but we want an unsigned long result */
197 static inline unsigned long of_read_ulong(const __be32 *cell, int size)
198 {
199 	/* toss away upper bits if unsigned long is smaller than u64 */
200 	return of_read_number(cell, size);
201 }
202 
203 #if defined(CONFIG_SPARC)
204 #include <asm/prom.h>
205 #endif
206 
207 /* Default #address and #size cells.  Allow arch asm/prom.h to override */
208 #if !defined(OF_ROOT_NODE_ADDR_CELLS_DEFAULT)
209 #define OF_ROOT_NODE_ADDR_CELLS_DEFAULT 1
210 #define OF_ROOT_NODE_SIZE_CELLS_DEFAULT 1
211 #endif
212 
213 /* Default string compare functions, Allow arch asm/prom.h to override */
214 #if !defined(of_compat_cmp)
215 #define of_compat_cmp(s1, s2, l)	strcasecmp((s1), (s2))
216 #define of_prop_cmp(s1, s2)		strcmp((s1), (s2))
217 #define of_node_cmp(s1, s2)		strcasecmp((s1), (s2))
218 #endif
219 
220 /* flag descriptions */
221 #define OF_DYNAMIC	1 /* node and properties were allocated via kmalloc */
222 #define OF_DETACHED	2 /* node has been detached from the device tree */
223 #define OF_POPULATED	3 /* device already created for the node */
224 #define OF_POPULATED_BUS	4 /* of_platform_populate recursed to children of this node */
225 
226 #define OF_IS_DYNAMIC(x) test_bit(OF_DYNAMIC, &x->_flags)
227 #define OF_MARK_DYNAMIC(x) set_bit(OF_DYNAMIC, &x->_flags)
228 
229 #define OF_BAD_ADDR	((u64)-1)
230 
231 static inline const char *of_node_full_name(const struct device_node *np)
232 {
233 	return np ? np->full_name : "<no-node>";
234 }
235 
236 #define for_each_of_allnodes_from(from, dn) \
237 	for (dn = __of_find_all_nodes(from); dn; dn = __of_find_all_nodes(dn))
238 #define for_each_of_allnodes(dn) for_each_of_allnodes_from(NULL, dn)
239 extern struct device_node *of_find_node_by_name(struct device_node *from,
240 	const char *name);
241 extern struct device_node *of_find_node_by_type(struct device_node *from,
242 	const char *type);
243 extern struct device_node *of_find_compatible_node(struct device_node *from,
244 	const char *type, const char *compat);
245 extern struct device_node *of_find_matching_node_and_match(
246 	struct device_node *from,
247 	const struct of_device_id *matches,
248 	const struct of_device_id **match);
249 
250 extern struct device_node *of_find_node_opts_by_path(const char *path,
251 	const char **opts);
252 static inline struct device_node *of_find_node_by_path(const char *path)
253 {
254 	return of_find_node_opts_by_path(path, NULL);
255 }
256 
257 extern struct device_node *of_find_node_by_phandle(phandle handle);
258 extern struct device_node *of_get_parent(const struct device_node *node);
259 extern struct device_node *of_get_next_parent(struct device_node *node);
260 extern struct device_node *of_get_next_child(const struct device_node *node,
261 					     struct device_node *prev);
262 extern struct device_node *of_get_next_available_child(
263 	const struct device_node *node, struct device_node *prev);
264 
265 extern struct device_node *of_get_child_by_name(const struct device_node *node,
266 					const char *name);
267 
268 /* cache lookup */
269 extern struct device_node *of_find_next_cache_node(const struct device_node *);
270 extern struct device_node *of_find_node_with_property(
271 	struct device_node *from, const char *prop_name);
272 
273 extern struct property *of_find_property(const struct device_node *np,
274 					 const char *name,
275 					 int *lenp);
276 extern int of_property_count_elems_of_size(const struct device_node *np,
277 				const char *propname, int elem_size);
278 extern int of_property_read_u32_index(const struct device_node *np,
279 				       const char *propname,
280 				       u32 index, u32 *out_value);
281 extern int of_property_read_u8_array(const struct device_node *np,
282 			const char *propname, u8 *out_values, size_t sz);
283 extern int of_property_read_u16_array(const struct device_node *np,
284 			const char *propname, u16 *out_values, size_t sz);
285 extern int of_property_read_u32_array(const struct device_node *np,
286 				      const char *propname,
287 				      u32 *out_values,
288 				      size_t sz);
289 extern int of_property_read_u64(const struct device_node *np,
290 				const char *propname, u64 *out_value);
291 extern int of_property_read_u64_array(const struct device_node *np,
292 				      const char *propname,
293 				      u64 *out_values,
294 				      size_t sz);
295 
296 extern int of_property_read_string(struct device_node *np,
297 				   const char *propname,
298 				   const char **out_string);
299 extern int of_property_match_string(struct device_node *np,
300 				    const char *propname,
301 				    const char *string);
302 extern int of_property_read_string_helper(struct device_node *np,
303 					      const char *propname,
304 					      const char **out_strs, size_t sz, int index);
305 extern int of_device_is_compatible(const struct device_node *device,
306 				   const char *);
307 extern bool of_device_is_available(const struct device_node *device);
308 extern const void *of_get_property(const struct device_node *node,
309 				const char *name,
310 				int *lenp);
311 extern struct device_node *of_get_cpu_node(int cpu, unsigned int *thread);
312 #define for_each_property_of_node(dn, pp) \
313 	for (pp = dn->properties; pp != NULL; pp = pp->next)
314 
315 extern int of_n_addr_cells(struct device_node *np);
316 extern int of_n_size_cells(struct device_node *np);
317 extern const struct of_device_id *of_match_node(
318 	const struct of_device_id *matches, const struct device_node *node);
319 extern int of_modalias_node(struct device_node *node, char *modalias, int len);
320 extern void of_print_phandle_args(const char *msg, const struct of_phandle_args *args);
321 extern struct device_node *of_parse_phandle(const struct device_node *np,
322 					    const char *phandle_name,
323 					    int index);
324 extern int of_parse_phandle_with_args(const struct device_node *np,
325 	const char *list_name, const char *cells_name, int index,
326 	struct of_phandle_args *out_args);
327 extern int of_parse_phandle_with_fixed_args(const struct device_node *np,
328 	const char *list_name, int cells_count, int index,
329 	struct of_phandle_args *out_args);
330 extern int of_count_phandle_with_args(const struct device_node *np,
331 	const char *list_name, const char *cells_name);
332 
333 extern void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align));
334 extern int of_alias_get_id(struct device_node *np, const char *stem);
335 
336 extern int of_machine_is_compatible(const char *compat);
337 
338 extern int of_add_property(struct device_node *np, struct property *prop);
339 extern int of_remove_property(struct device_node *np, struct property *prop);
340 extern int of_update_property(struct device_node *np, struct property *newprop);
341 
342 /* For updating the device tree at runtime */
343 #define OF_RECONFIG_ATTACH_NODE		0x0001
344 #define OF_RECONFIG_DETACH_NODE		0x0002
345 #define OF_RECONFIG_ADD_PROPERTY	0x0003
346 #define OF_RECONFIG_REMOVE_PROPERTY	0x0004
347 #define OF_RECONFIG_UPDATE_PROPERTY	0x0005
348 
349 extern int of_attach_node(struct device_node *);
350 extern int of_detach_node(struct device_node *);
351 
352 #define of_match_ptr(_ptr)	(_ptr)
353 
354 /*
355  * struct property *prop;
356  * const __be32 *p;
357  * u32 u;
358  *
359  * of_property_for_each_u32(np, "propname", prop, p, u)
360  *         printk("U32 value: %x\n", u);
361  */
362 const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
363 			       u32 *pu);
364 /*
365  * struct property *prop;
366  * const char *s;
367  *
368  * of_property_for_each_string(np, "propname", prop, s)
369  *         printk("String value: %s\n", s);
370  */
371 const char *of_prop_next_string(struct property *prop, const char *cur);
372 
373 bool of_console_check(struct device_node *dn, char *name, int index);
374 
375 #else /* CONFIG_OF */
376 
377 static inline bool is_of_node(struct fwnode_handle *fwnode)
378 {
379 	return false;
380 }
381 
382 static inline struct device_node *of_node(struct fwnode_handle *fwnode)
383 {
384 	return NULL;
385 }
386 
387 static inline const char* of_node_full_name(const struct device_node *np)
388 {
389 	return "<no-node>";
390 }
391 
392 static inline struct device_node *of_find_node_by_name(struct device_node *from,
393 	const char *name)
394 {
395 	return NULL;
396 }
397 
398 static inline struct device_node *of_find_node_by_type(struct device_node *from,
399 	const char *type)
400 {
401 	return NULL;
402 }
403 
404 static inline struct device_node *of_find_matching_node_and_match(
405 	struct device_node *from,
406 	const struct of_device_id *matches,
407 	const struct of_device_id **match)
408 {
409 	return NULL;
410 }
411 
412 static inline struct device_node *of_find_node_by_path(const char *path)
413 {
414 	return NULL;
415 }
416 
417 static inline struct device_node *of_find_node_opts_by_path(const char *path,
418 	const char **opts)
419 {
420 	return NULL;
421 }
422 
423 static inline struct device_node *of_get_parent(const struct device_node *node)
424 {
425 	return NULL;
426 }
427 
428 static inline struct device_node *of_get_next_child(
429 	const struct device_node *node, struct device_node *prev)
430 {
431 	return NULL;
432 }
433 
434 static inline struct device_node *of_get_next_available_child(
435 	const struct device_node *node, struct device_node *prev)
436 {
437 	return NULL;
438 }
439 
440 static inline struct device_node *of_find_node_with_property(
441 	struct device_node *from, const char *prop_name)
442 {
443 	return NULL;
444 }
445 
446 static inline bool of_have_populated_dt(void)
447 {
448 	return false;
449 }
450 
451 static inline struct device_node *of_get_child_by_name(
452 					const struct device_node *node,
453 					const char *name)
454 {
455 	return NULL;
456 }
457 
458 static inline int of_device_is_compatible(const struct device_node *device,
459 					  const char *name)
460 {
461 	return 0;
462 }
463 
464 static inline bool of_device_is_available(const struct device_node *device)
465 {
466 	return false;
467 }
468 
469 static inline struct property *of_find_property(const struct device_node *np,
470 						const char *name,
471 						int *lenp)
472 {
473 	return NULL;
474 }
475 
476 static inline struct device_node *of_find_compatible_node(
477 						struct device_node *from,
478 						const char *type,
479 						const char *compat)
480 {
481 	return NULL;
482 }
483 
484 static inline int of_property_count_elems_of_size(const struct device_node *np,
485 			const char *propname, int elem_size)
486 {
487 	return -ENOSYS;
488 }
489 
490 static inline int of_property_read_u32_index(const struct device_node *np,
491 			const char *propname, u32 index, u32 *out_value)
492 {
493 	return -ENOSYS;
494 }
495 
496 static inline int of_property_read_u8_array(const struct device_node *np,
497 			const char *propname, u8 *out_values, size_t sz)
498 {
499 	return -ENOSYS;
500 }
501 
502 static inline int of_property_read_u16_array(const struct device_node *np,
503 			const char *propname, u16 *out_values, size_t sz)
504 {
505 	return -ENOSYS;
506 }
507 
508 static inline int of_property_read_u32_array(const struct device_node *np,
509 					     const char *propname,
510 					     u32 *out_values, size_t sz)
511 {
512 	return -ENOSYS;
513 }
514 
515 static inline int of_property_read_u64_array(const struct device_node *np,
516 					     const char *propname,
517 					     u64 *out_values, size_t sz)
518 {
519 	return -ENOSYS;
520 }
521 
522 static inline int of_property_read_string(struct device_node *np,
523 					  const char *propname,
524 					  const char **out_string)
525 {
526 	return -ENOSYS;
527 }
528 
529 static inline int of_property_read_string_helper(struct device_node *np,
530 						 const char *propname,
531 						 const char **out_strs, size_t sz, int index)
532 {
533 	return -ENOSYS;
534 }
535 
536 static inline const void *of_get_property(const struct device_node *node,
537 				const char *name,
538 				int *lenp)
539 {
540 	return NULL;
541 }
542 
543 static inline struct device_node *of_get_cpu_node(int cpu,
544 					unsigned int *thread)
545 {
546 	return NULL;
547 }
548 
549 static inline int of_property_read_u64(const struct device_node *np,
550 				       const char *propname, u64 *out_value)
551 {
552 	return -ENOSYS;
553 }
554 
555 static inline int of_property_match_string(struct device_node *np,
556 					   const char *propname,
557 					   const char *string)
558 {
559 	return -ENOSYS;
560 }
561 
562 static inline struct device_node *of_parse_phandle(const struct device_node *np,
563 						   const char *phandle_name,
564 						   int index)
565 {
566 	return NULL;
567 }
568 
569 static inline int of_parse_phandle_with_args(struct device_node *np,
570 					     const char *list_name,
571 					     const char *cells_name,
572 					     int index,
573 					     struct of_phandle_args *out_args)
574 {
575 	return -ENOSYS;
576 }
577 
578 static inline int of_parse_phandle_with_fixed_args(const struct device_node *np,
579 	const char *list_name, int cells_count, int index,
580 	struct of_phandle_args *out_args)
581 {
582 	return -ENOSYS;
583 }
584 
585 static inline int of_count_phandle_with_args(struct device_node *np,
586 					     const char *list_name,
587 					     const char *cells_name)
588 {
589 	return -ENOSYS;
590 }
591 
592 static inline int of_alias_get_id(struct device_node *np, const char *stem)
593 {
594 	return -ENOSYS;
595 }
596 
597 static inline int of_machine_is_compatible(const char *compat)
598 {
599 	return 0;
600 }
601 
602 static inline bool of_console_check(const struct device_node *dn, const char *name, int index)
603 {
604 	return false;
605 }
606 
607 static inline const __be32 *of_prop_next_u32(struct property *prop,
608 		const __be32 *cur, u32 *pu)
609 {
610 	return NULL;
611 }
612 
613 static inline const char *of_prop_next_string(struct property *prop,
614 		const char *cur)
615 {
616 	return NULL;
617 }
618 
619 #define of_match_ptr(_ptr)	NULL
620 #define of_match_node(_matches, _node)	NULL
621 #endif /* CONFIG_OF */
622 
623 #if defined(CONFIG_OF) && defined(CONFIG_NUMA)
624 extern int of_node_to_nid(struct device_node *np);
625 #else
626 static inline int of_node_to_nid(struct device_node *device) { return 0; }
627 #endif
628 
629 static inline struct device_node *of_find_matching_node(
630 	struct device_node *from,
631 	const struct of_device_id *matches)
632 {
633 	return of_find_matching_node_and_match(from, matches, NULL);
634 }
635 
636 /**
637  * of_property_count_u8_elems - Count the number of u8 elements in a property
638  *
639  * @np:		device node from which the property value is to be read.
640  * @propname:	name of the property to be searched.
641  *
642  * Search for a property in a device node and count the number of u8 elements
643  * in it. Returns number of elements on sucess, -EINVAL if the property does
644  * not exist or its length does not match a multiple of u8 and -ENODATA if the
645  * property does not have a value.
646  */
647 static inline int of_property_count_u8_elems(const struct device_node *np,
648 				const char *propname)
649 {
650 	return of_property_count_elems_of_size(np, propname, sizeof(u8));
651 }
652 
653 /**
654  * of_property_count_u16_elems - Count the number of u16 elements in a property
655  *
656  * @np:		device node from which the property value is to be read.
657  * @propname:	name of the property to be searched.
658  *
659  * Search for a property in a device node and count the number of u16 elements
660  * in it. Returns number of elements on sucess, -EINVAL if the property does
661  * not exist or its length does not match a multiple of u16 and -ENODATA if the
662  * property does not have a value.
663  */
664 static inline int of_property_count_u16_elems(const struct device_node *np,
665 				const char *propname)
666 {
667 	return of_property_count_elems_of_size(np, propname, sizeof(u16));
668 }
669 
670 /**
671  * of_property_count_u32_elems - Count the number of u32 elements in a property
672  *
673  * @np:		device node from which the property value is to be read.
674  * @propname:	name of the property to be searched.
675  *
676  * Search for a property in a device node and count the number of u32 elements
677  * in it. Returns number of elements on sucess, -EINVAL if the property does
678  * not exist or its length does not match a multiple of u32 and -ENODATA if the
679  * property does not have a value.
680  */
681 static inline int of_property_count_u32_elems(const struct device_node *np,
682 				const char *propname)
683 {
684 	return of_property_count_elems_of_size(np, propname, sizeof(u32));
685 }
686 
687 /**
688  * of_property_count_u64_elems - Count the number of u64 elements in a property
689  *
690  * @np:		device node from which the property value is to be read.
691  * @propname:	name of the property to be searched.
692  *
693  * Search for a property in a device node and count the number of u64 elements
694  * in it. Returns number of elements on sucess, -EINVAL if the property does
695  * not exist or its length does not match a multiple of u64 and -ENODATA if the
696  * property does not have a value.
697  */
698 static inline int of_property_count_u64_elems(const struct device_node *np,
699 				const char *propname)
700 {
701 	return of_property_count_elems_of_size(np, propname, sizeof(u64));
702 }
703 
704 /**
705  * of_property_read_string_array() - Read an array of strings from a multiple
706  * strings property.
707  * @np:		device node from which the property value is to be read.
708  * @propname:	name of the property to be searched.
709  * @out_strs:	output array of string pointers.
710  * @sz:		number of array elements to read.
711  *
712  * Search for a property in a device tree node and retrieve a list of
713  * terminated string values (pointer to data, not a copy) in that property.
714  *
715  * If @out_strs is NULL, the number of strings in the property is returned.
716  */
717 static inline int of_property_read_string_array(struct device_node *np,
718 						const char *propname, const char **out_strs,
719 						size_t sz)
720 {
721 	return of_property_read_string_helper(np, propname, out_strs, sz, 0);
722 }
723 
724 /**
725  * of_property_count_strings() - Find and return the number of strings from a
726  * multiple strings property.
727  * @np:		device node from which the property value is to be read.
728  * @propname:	name of the property to be searched.
729  *
730  * Search for a property in a device tree node and retrieve the number of null
731  * terminated string contain in it. Returns the number of strings on
732  * success, -EINVAL if the property does not exist, -ENODATA if property
733  * does not have a value, and -EILSEQ if the string is not null-terminated
734  * within the length of the property data.
735  */
736 static inline int of_property_count_strings(struct device_node *np,
737 					    const char *propname)
738 {
739 	return of_property_read_string_helper(np, propname, NULL, 0, 0);
740 }
741 
742 /**
743  * of_property_read_string_index() - Find and read a string from a multiple
744  * strings property.
745  * @np:		device node from which the property value is to be read.
746  * @propname:	name of the property to be searched.
747  * @index:	index of the string in the list of strings
748  * @out_string:	pointer to null terminated return string, modified only if
749  *		return value is 0.
750  *
751  * Search for a property in a device tree node and retrieve a null
752  * terminated string value (pointer to data, not a copy) in the list of strings
753  * contained in that property.
754  * Returns 0 on success, -EINVAL if the property does not exist, -ENODATA if
755  * property does not have a value, and -EILSEQ if the string is not
756  * null-terminated within the length of the property data.
757  *
758  * The out_string pointer is modified only if a valid string can be decoded.
759  */
760 static inline int of_property_read_string_index(struct device_node *np,
761 						const char *propname,
762 						int index, const char **output)
763 {
764 	int rc = of_property_read_string_helper(np, propname, output, 1, index);
765 	return rc < 0 ? rc : 0;
766 }
767 
768 /**
769  * of_property_read_bool - Findfrom a property
770  * @np:		device node from which the property value is to be read.
771  * @propname:	name of the property to be searched.
772  *
773  * Search for a property in a device node.
774  * Returns true if the property exist false otherwise.
775  */
776 static inline bool of_property_read_bool(const struct device_node *np,
777 					 const char *propname)
778 {
779 	struct property *prop = of_find_property(np, propname, NULL);
780 
781 	return prop ? true : false;
782 }
783 
784 static inline int of_property_read_u8(const struct device_node *np,
785 				       const char *propname,
786 				       u8 *out_value)
787 {
788 	return of_property_read_u8_array(np, propname, out_value, 1);
789 }
790 
791 static inline int of_property_read_u16(const struct device_node *np,
792 				       const char *propname,
793 				       u16 *out_value)
794 {
795 	return of_property_read_u16_array(np, propname, out_value, 1);
796 }
797 
798 static inline int of_property_read_u32(const struct device_node *np,
799 				       const char *propname,
800 				       u32 *out_value)
801 {
802 	return of_property_read_u32_array(np, propname, out_value, 1);
803 }
804 
805 static inline int of_property_read_s32(const struct device_node *np,
806 				       const char *propname,
807 				       s32 *out_value)
808 {
809 	return of_property_read_u32(np, propname, (u32*) out_value);
810 }
811 
812 #define of_property_for_each_u32(np, propname, prop, p, u)	\
813 	for (prop = of_find_property(np, propname, NULL),	\
814 		p = of_prop_next_u32(prop, NULL, &u);		\
815 		p;						\
816 		p = of_prop_next_u32(prop, p, &u))
817 
818 #define of_property_for_each_string(np, propname, prop, s)	\
819 	for (prop = of_find_property(np, propname, NULL),	\
820 		s = of_prop_next_string(prop, NULL);		\
821 		s;						\
822 		s = of_prop_next_string(prop, s))
823 
824 #define for_each_node_by_name(dn, name) \
825 	for (dn = of_find_node_by_name(NULL, name); dn; \
826 	     dn = of_find_node_by_name(dn, name))
827 #define for_each_node_by_type(dn, type) \
828 	for (dn = of_find_node_by_type(NULL, type); dn; \
829 	     dn = of_find_node_by_type(dn, type))
830 #define for_each_compatible_node(dn, type, compatible) \
831 	for (dn = of_find_compatible_node(NULL, type, compatible); dn; \
832 	     dn = of_find_compatible_node(dn, type, compatible))
833 #define for_each_matching_node(dn, matches) \
834 	for (dn = of_find_matching_node(NULL, matches); dn; \
835 	     dn = of_find_matching_node(dn, matches))
836 #define for_each_matching_node_and_match(dn, matches, match) \
837 	for (dn = of_find_matching_node_and_match(NULL, matches, match); \
838 	     dn; dn = of_find_matching_node_and_match(dn, matches, match))
839 
840 #define for_each_child_of_node(parent, child) \
841 	for (child = of_get_next_child(parent, NULL); child != NULL; \
842 	     child = of_get_next_child(parent, child))
843 #define for_each_available_child_of_node(parent, child) \
844 	for (child = of_get_next_available_child(parent, NULL); child != NULL; \
845 	     child = of_get_next_available_child(parent, child))
846 
847 #define for_each_node_with_property(dn, prop_name) \
848 	for (dn = of_find_node_with_property(NULL, prop_name); dn; \
849 	     dn = of_find_node_with_property(dn, prop_name))
850 
851 static inline int of_get_child_count(const struct device_node *np)
852 {
853 	struct device_node *child;
854 	int num = 0;
855 
856 	for_each_child_of_node(np, child)
857 		num++;
858 
859 	return num;
860 }
861 
862 static inline int of_get_available_child_count(const struct device_node *np)
863 {
864 	struct device_node *child;
865 	int num = 0;
866 
867 	for_each_available_child_of_node(np, child)
868 		num++;
869 
870 	return num;
871 }
872 
873 #ifdef CONFIG_OF
874 #define _OF_DECLARE(table, name, compat, fn, fn_type)			\
875 	static const struct of_device_id __of_table_##name		\
876 		__used __section(__##table##_of_table)			\
877 		 = { .compatible = compat,				\
878 		     .data = (fn == (fn_type)NULL) ? fn : fn  }
879 #else
880 #define _OF_DECLARE(table, name, compat, fn, fn_type)			\
881 	static const struct of_device_id __of_table_##name		\
882 		__attribute__((unused))					\
883 		 = { .compatible = compat,				\
884 		     .data = (fn == (fn_type)NULL) ? fn : fn }
885 #endif
886 
887 typedef int (*of_init_fn_2)(struct device_node *, struct device_node *);
888 typedef void (*of_init_fn_1)(struct device_node *);
889 
890 #define OF_DECLARE_1(table, name, compat, fn) \
891 		_OF_DECLARE(table, name, compat, fn, of_init_fn_1)
892 #define OF_DECLARE_2(table, name, compat, fn) \
893 		_OF_DECLARE(table, name, compat, fn, of_init_fn_2)
894 
895 /**
896  * struct of_changeset_entry	- Holds a changeset entry
897  *
898  * @node:	list_head for the log list
899  * @action:	notifier action
900  * @np:		pointer to the device node affected
901  * @prop:	pointer to the property affected
902  * @old_prop:	hold a pointer to the original property
903  *
904  * Every modification of the device tree during a changeset
905  * is held in a list of of_changeset_entry structures.
906  * That way we can recover from a partial application, or we can
907  * revert the changeset
908  */
909 struct of_changeset_entry {
910 	struct list_head node;
911 	unsigned long action;
912 	struct device_node *np;
913 	struct property *prop;
914 	struct property *old_prop;
915 };
916 
917 /**
918  * struct of_changeset - changeset tracker structure
919  *
920  * @entries:	list_head for the changeset entries
921  *
922  * changesets are a convenient way to apply bulk changes to the
923  * live tree. In case of an error, changes are rolled-back.
924  * changesets live on after initial application, and if not
925  * destroyed after use, they can be reverted in one single call.
926  */
927 struct of_changeset {
928 	struct list_head entries;
929 };
930 
931 enum of_reconfig_change {
932 	OF_RECONFIG_NO_CHANGE = 0,
933 	OF_RECONFIG_CHANGE_ADD,
934 	OF_RECONFIG_CHANGE_REMOVE,
935 };
936 
937 #ifdef CONFIG_OF_DYNAMIC
938 extern int of_reconfig_notifier_register(struct notifier_block *);
939 extern int of_reconfig_notifier_unregister(struct notifier_block *);
940 extern int of_reconfig_notify(unsigned long, struct of_reconfig_data *rd);
941 extern int of_reconfig_get_state_change(unsigned long action,
942 					struct of_reconfig_data *arg);
943 
944 extern void of_changeset_init(struct of_changeset *ocs);
945 extern void of_changeset_destroy(struct of_changeset *ocs);
946 extern int of_changeset_apply(struct of_changeset *ocs);
947 extern int of_changeset_revert(struct of_changeset *ocs);
948 extern int of_changeset_action(struct of_changeset *ocs,
949 		unsigned long action, struct device_node *np,
950 		struct property *prop);
951 
952 static inline int of_changeset_attach_node(struct of_changeset *ocs,
953 		struct device_node *np)
954 {
955 	return of_changeset_action(ocs, OF_RECONFIG_ATTACH_NODE, np, NULL);
956 }
957 
958 static inline int of_changeset_detach_node(struct of_changeset *ocs,
959 		struct device_node *np)
960 {
961 	return of_changeset_action(ocs, OF_RECONFIG_DETACH_NODE, np, NULL);
962 }
963 
964 static inline int of_changeset_add_property(struct of_changeset *ocs,
965 		struct device_node *np, struct property *prop)
966 {
967 	return of_changeset_action(ocs, OF_RECONFIG_ADD_PROPERTY, np, prop);
968 }
969 
970 static inline int of_changeset_remove_property(struct of_changeset *ocs,
971 		struct device_node *np, struct property *prop)
972 {
973 	return of_changeset_action(ocs, OF_RECONFIG_REMOVE_PROPERTY, np, prop);
974 }
975 
976 static inline int of_changeset_update_property(struct of_changeset *ocs,
977 		struct device_node *np, struct property *prop)
978 {
979 	return of_changeset_action(ocs, OF_RECONFIG_UPDATE_PROPERTY, np, prop);
980 }
981 #else /* CONFIG_OF_DYNAMIC */
982 static inline int of_reconfig_notifier_register(struct notifier_block *nb)
983 {
984 	return -EINVAL;
985 }
986 static inline int of_reconfig_notifier_unregister(struct notifier_block *nb)
987 {
988 	return -EINVAL;
989 }
990 static inline int of_reconfig_notify(unsigned long action,
991 				     struct of_reconfig_data *arg)
992 {
993 	return -EINVAL;
994 }
995 static inline int of_reconfig_get_state_change(unsigned long action,
996 						struct of_reconfig_data *arg)
997 {
998 	return -EINVAL;
999 }
1000 #endif /* CONFIG_OF_DYNAMIC */
1001 
1002 /* CONFIG_OF_RESOLVE api */
1003 extern int of_resolve_phandles(struct device_node *tree);
1004 
1005 /**
1006  * of_device_is_system_power_controller - Tells if system-power-controller is found for device_node
1007  * @np: Pointer to the given device_node
1008  *
1009  * return true if present false otherwise
1010  */
1011 static inline bool of_device_is_system_power_controller(const struct device_node *np)
1012 {
1013 	return of_property_read_bool(np, "system-power-controller");
1014 }
1015 
1016 /**
1017  * Overlay support
1018  */
1019 
1020 #ifdef CONFIG_OF_OVERLAY
1021 
1022 /* ID based overlays; the API for external users */
1023 int of_overlay_create(struct device_node *tree);
1024 int of_overlay_destroy(int id);
1025 int of_overlay_destroy_all(void);
1026 
1027 #else
1028 
1029 static inline int of_overlay_create(struct device_node *tree)
1030 {
1031 	return -ENOTSUPP;
1032 }
1033 
1034 static inline int of_overlay_destroy(int id)
1035 {
1036 	return -ENOTSUPP;
1037 }
1038 
1039 static inline int of_overlay_destroy_all(void)
1040 {
1041 	return -ENOTSUPP;
1042 }
1043 
1044 #endif
1045 
1046 #endif /* _LINUX_OF_H */
1047