xref: /openbmc/linux/drivers/of/property.c (revision 1802d0be)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * drivers/of/property.c - Procedures for accessing and interpreting
4  *			   Devicetree properties and graphs.
5  *
6  * Initially created by copying procedures from drivers/of/base.c. This
7  * file contains the OF property as well as the OF graph interface
8  * functions.
9  *
10  * Paul Mackerras	August 1996.
11  * Copyright (C) 1996-2005 Paul Mackerras.
12  *
13  *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
14  *    {engebret|bergner}@us.ibm.com
15  *
16  *  Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
17  *
18  *  Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
19  *  Grant Likely.
20  */
21 
22 #define pr_fmt(fmt)	"OF: " fmt
23 
24 #include <linux/of.h>
25 #include <linux/of_device.h>
26 #include <linux/of_graph.h>
27 #include <linux/string.h>
28 
29 #include "of_private.h"
30 
31 /**
32  * of_property_count_elems_of_size - Count the number of elements in a property
33  *
34  * @np:		device node from which the property value is to be read.
35  * @propname:	name of the property to be searched.
36  * @elem_size:	size of the individual element
37  *
38  * Search for a property in a device node and count the number of elements of
39  * size elem_size in it. Returns number of elements on sucess, -EINVAL if the
40  * property does not exist or its length does not match a multiple of elem_size
41  * and -ENODATA if the property does not have a value.
42  */
43 int of_property_count_elems_of_size(const struct device_node *np,
44 				const char *propname, int elem_size)
45 {
46 	struct property *prop = of_find_property(np, propname, NULL);
47 
48 	if (!prop)
49 		return -EINVAL;
50 	if (!prop->value)
51 		return -ENODATA;
52 
53 	if (prop->length % elem_size != 0) {
54 		pr_err("size of %s in node %pOF is not a multiple of %d\n",
55 		       propname, np, elem_size);
56 		return -EINVAL;
57 	}
58 
59 	return prop->length / elem_size;
60 }
61 EXPORT_SYMBOL_GPL(of_property_count_elems_of_size);
62 
63 /**
64  * of_find_property_value_of_size
65  *
66  * @np:		device node from which the property value is to be read.
67  * @propname:	name of the property to be searched.
68  * @min:	minimum allowed length of property value
69  * @max:	maximum allowed length of property value (0 means unlimited)
70  * @len:	if !=NULL, actual length is written to here
71  *
72  * Search for a property in a device node and valid the requested size.
73  * Returns the property value on success, -EINVAL if the property does not
74  *  exist, -ENODATA if property does not have a value, and -EOVERFLOW if the
75  * property data is too small or too large.
76  *
77  */
78 static void *of_find_property_value_of_size(const struct device_node *np,
79 			const char *propname, u32 min, u32 max, size_t *len)
80 {
81 	struct property *prop = of_find_property(np, propname, NULL);
82 
83 	if (!prop)
84 		return ERR_PTR(-EINVAL);
85 	if (!prop->value)
86 		return ERR_PTR(-ENODATA);
87 	if (prop->length < min)
88 		return ERR_PTR(-EOVERFLOW);
89 	if (max && prop->length > max)
90 		return ERR_PTR(-EOVERFLOW);
91 
92 	if (len)
93 		*len = prop->length;
94 
95 	return prop->value;
96 }
97 
98 /**
99  * of_property_read_u32_index - Find and read a u32 from a multi-value property.
100  *
101  * @np:		device node from which the property value is to be read.
102  * @propname:	name of the property to be searched.
103  * @index:	index of the u32 in the list of values
104  * @out_value:	pointer to return value, modified only if no error.
105  *
106  * Search for a property in a device node and read nth 32-bit value from
107  * it. Returns 0 on success, -EINVAL if the property does not exist,
108  * -ENODATA if property does not have a value, and -EOVERFLOW if the
109  * property data isn't large enough.
110  *
111  * The out_value is modified only if a valid u32 value can be decoded.
112  */
113 int of_property_read_u32_index(const struct device_node *np,
114 				       const char *propname,
115 				       u32 index, u32 *out_value)
116 {
117 	const u32 *val = of_find_property_value_of_size(np, propname,
118 					((index + 1) * sizeof(*out_value)),
119 					0,
120 					NULL);
121 
122 	if (IS_ERR(val))
123 		return PTR_ERR(val);
124 
125 	*out_value = be32_to_cpup(((__be32 *)val) + index);
126 	return 0;
127 }
128 EXPORT_SYMBOL_GPL(of_property_read_u32_index);
129 
130 /**
131  * of_property_read_u64_index - Find and read a u64 from a multi-value property.
132  *
133  * @np:		device node from which the property value is to be read.
134  * @propname:	name of the property to be searched.
135  * @index:	index of the u64 in the list of values
136  * @out_value:	pointer to return value, modified only if no error.
137  *
138  * Search for a property in a device node and read nth 64-bit value from
139  * it. Returns 0 on success, -EINVAL if the property does not exist,
140  * -ENODATA if property does not have a value, and -EOVERFLOW if the
141  * property data isn't large enough.
142  *
143  * The out_value is modified only if a valid u64 value can be decoded.
144  */
145 int of_property_read_u64_index(const struct device_node *np,
146 				       const char *propname,
147 				       u32 index, u64 *out_value)
148 {
149 	const u64 *val = of_find_property_value_of_size(np, propname,
150 					((index + 1) * sizeof(*out_value)),
151 					0, NULL);
152 
153 	if (IS_ERR(val))
154 		return PTR_ERR(val);
155 
156 	*out_value = be64_to_cpup(((__be64 *)val) + index);
157 	return 0;
158 }
159 EXPORT_SYMBOL_GPL(of_property_read_u64_index);
160 
161 /**
162  * of_property_read_variable_u8_array - Find and read an array of u8 from a
163  * property, with bounds on the minimum and maximum array size.
164  *
165  * @np:		device node from which the property value is to be read.
166  * @propname:	name of the property to be searched.
167  * @out_values:	pointer to return value, modified only if return value is 0.
168  * @sz_min:	minimum number of array elements to read
169  * @sz_max:	maximum number of array elements to read, if zero there is no
170  *		upper limit on the number of elements in the dts entry but only
171  *		sz_min will be read.
172  *
173  * Search for a property in a device node and read 8-bit value(s) from
174  * it. Returns number of elements read on success, -EINVAL if the property
175  * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
176  * if the property data is smaller than sz_min or longer than sz_max.
177  *
178  * dts entry of array should be like:
179  *	property = /bits/ 8 <0x50 0x60 0x70>;
180  *
181  * The out_values is modified only if a valid u8 value can be decoded.
182  */
183 int of_property_read_variable_u8_array(const struct device_node *np,
184 					const char *propname, u8 *out_values,
185 					size_t sz_min, size_t sz_max)
186 {
187 	size_t sz, count;
188 	const u8 *val = of_find_property_value_of_size(np, propname,
189 						(sz_min * sizeof(*out_values)),
190 						(sz_max * sizeof(*out_values)),
191 						&sz);
192 
193 	if (IS_ERR(val))
194 		return PTR_ERR(val);
195 
196 	if (!sz_max)
197 		sz = sz_min;
198 	else
199 		sz /= sizeof(*out_values);
200 
201 	count = sz;
202 	while (count--)
203 		*out_values++ = *val++;
204 
205 	return sz;
206 }
207 EXPORT_SYMBOL_GPL(of_property_read_variable_u8_array);
208 
209 /**
210  * of_property_read_variable_u16_array - Find and read an array of u16 from a
211  * property, with bounds on the minimum and maximum array size.
212  *
213  * @np:		device node from which the property value is to be read.
214  * @propname:	name of the property to be searched.
215  * @out_values:	pointer to return value, modified only if return value is 0.
216  * @sz_min:	minimum number of array elements to read
217  * @sz_max:	maximum number of array elements to read, if zero there is no
218  *		upper limit on the number of elements in the dts entry but only
219  *		sz_min will be read.
220  *
221  * Search for a property in a device node and read 16-bit value(s) from
222  * it. Returns number of elements read on success, -EINVAL if the property
223  * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
224  * if the property data is smaller than sz_min or longer than sz_max.
225  *
226  * dts entry of array should be like:
227  *	property = /bits/ 16 <0x5000 0x6000 0x7000>;
228  *
229  * The out_values is modified only if a valid u16 value can be decoded.
230  */
231 int of_property_read_variable_u16_array(const struct device_node *np,
232 					const char *propname, u16 *out_values,
233 					size_t sz_min, size_t sz_max)
234 {
235 	size_t sz, count;
236 	const __be16 *val = of_find_property_value_of_size(np, propname,
237 						(sz_min * sizeof(*out_values)),
238 						(sz_max * sizeof(*out_values)),
239 						&sz);
240 
241 	if (IS_ERR(val))
242 		return PTR_ERR(val);
243 
244 	if (!sz_max)
245 		sz = sz_min;
246 	else
247 		sz /= sizeof(*out_values);
248 
249 	count = sz;
250 	while (count--)
251 		*out_values++ = be16_to_cpup(val++);
252 
253 	return sz;
254 }
255 EXPORT_SYMBOL_GPL(of_property_read_variable_u16_array);
256 
257 /**
258  * of_property_read_variable_u32_array - Find and read an array of 32 bit
259  * integers from a property, with bounds on the minimum and maximum array size.
260  *
261  * @np:		device node from which the property value is to be read.
262  * @propname:	name of the property to be searched.
263  * @out_values:	pointer to return value, modified only if return value is 0.
264  * @sz_min:	minimum number of array elements to read
265  * @sz_max:	maximum number of array elements to read, if zero there is no
266  *		upper limit on the number of elements in the dts entry but only
267  *		sz_min will be read.
268  *
269  * Search for a property in a device node and read 32-bit value(s) from
270  * it. Returns number of elements read on success, -EINVAL if the property
271  * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
272  * if the property data is smaller than sz_min or longer than sz_max.
273  *
274  * The out_values is modified only if a valid u32 value can be decoded.
275  */
276 int of_property_read_variable_u32_array(const struct device_node *np,
277 			       const char *propname, u32 *out_values,
278 			       size_t sz_min, size_t sz_max)
279 {
280 	size_t sz, count;
281 	const __be32 *val = of_find_property_value_of_size(np, propname,
282 						(sz_min * sizeof(*out_values)),
283 						(sz_max * sizeof(*out_values)),
284 						&sz);
285 
286 	if (IS_ERR(val))
287 		return PTR_ERR(val);
288 
289 	if (!sz_max)
290 		sz = sz_min;
291 	else
292 		sz /= sizeof(*out_values);
293 
294 	count = sz;
295 	while (count--)
296 		*out_values++ = be32_to_cpup(val++);
297 
298 	return sz;
299 }
300 EXPORT_SYMBOL_GPL(of_property_read_variable_u32_array);
301 
302 /**
303  * of_property_read_u64 - Find and read a 64 bit integer from a property
304  * @np:		device node from which the property value is to be read.
305  * @propname:	name of the property to be searched.
306  * @out_value:	pointer to return value, modified only if return value is 0.
307  *
308  * Search for a property in a device node and read a 64-bit value from
309  * it. Returns 0 on success, -EINVAL if the property does not exist,
310  * -ENODATA if property does not have a value, and -EOVERFLOW if the
311  * property data isn't large enough.
312  *
313  * The out_value is modified only if a valid u64 value can be decoded.
314  */
315 int of_property_read_u64(const struct device_node *np, const char *propname,
316 			 u64 *out_value)
317 {
318 	const __be32 *val = of_find_property_value_of_size(np, propname,
319 						sizeof(*out_value),
320 						0,
321 						NULL);
322 
323 	if (IS_ERR(val))
324 		return PTR_ERR(val);
325 
326 	*out_value = of_read_number(val, 2);
327 	return 0;
328 }
329 EXPORT_SYMBOL_GPL(of_property_read_u64);
330 
331 /**
332  * of_property_read_variable_u64_array - Find and read an array of 64 bit
333  * integers from a property, with bounds on the minimum and maximum array size.
334  *
335  * @np:		device node from which the property value is to be read.
336  * @propname:	name of the property to be searched.
337  * @out_values:	pointer to return value, modified only if return value is 0.
338  * @sz_min:	minimum number of array elements to read
339  * @sz_max:	maximum number of array elements to read, if zero there is no
340  *		upper limit on the number of elements in the dts entry but only
341  *		sz_min will be read.
342  *
343  * Search for a property in a device node and read 64-bit value(s) from
344  * it. Returns number of elements read on success, -EINVAL if the property
345  * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
346  * if the property data is smaller than sz_min or longer than sz_max.
347  *
348  * The out_values is modified only if a valid u64 value can be decoded.
349  */
350 int of_property_read_variable_u64_array(const struct device_node *np,
351 			       const char *propname, u64 *out_values,
352 			       size_t sz_min, size_t sz_max)
353 {
354 	size_t sz, count;
355 	const __be32 *val = of_find_property_value_of_size(np, propname,
356 						(sz_min * sizeof(*out_values)),
357 						(sz_max * sizeof(*out_values)),
358 						&sz);
359 
360 	if (IS_ERR(val))
361 		return PTR_ERR(val);
362 
363 	if (!sz_max)
364 		sz = sz_min;
365 	else
366 		sz /= sizeof(*out_values);
367 
368 	count = sz;
369 	while (count--) {
370 		*out_values++ = of_read_number(val, 2);
371 		val += 2;
372 	}
373 
374 	return sz;
375 }
376 EXPORT_SYMBOL_GPL(of_property_read_variable_u64_array);
377 
378 /**
379  * of_property_read_string - Find and read a string from a property
380  * @np:		device node from which the property value is to be read.
381  * @propname:	name of the property to be searched.
382  * @out_string:	pointer to null terminated return string, modified only if
383  *		return value is 0.
384  *
385  * Search for a property in a device tree node and retrieve a null
386  * terminated string value (pointer to data, not a copy). Returns 0 on
387  * success, -EINVAL if the property does not exist, -ENODATA if property
388  * does not have a value, and -EILSEQ if the string is not null-terminated
389  * within the length of the property data.
390  *
391  * The out_string pointer is modified only if a valid string can be decoded.
392  */
393 int of_property_read_string(const struct device_node *np, const char *propname,
394 				const char **out_string)
395 {
396 	const struct property *prop = of_find_property(np, propname, NULL);
397 	if (!prop)
398 		return -EINVAL;
399 	if (!prop->value)
400 		return -ENODATA;
401 	if (strnlen(prop->value, prop->length) >= prop->length)
402 		return -EILSEQ;
403 	*out_string = prop->value;
404 	return 0;
405 }
406 EXPORT_SYMBOL_GPL(of_property_read_string);
407 
408 /**
409  * of_property_match_string() - Find string in a list and return index
410  * @np: pointer to node containing string list property
411  * @propname: string list property name
412  * @string: pointer to string to search for in string list
413  *
414  * This function searches a string list property and returns the index
415  * of a specific string value.
416  */
417 int of_property_match_string(const struct device_node *np, const char *propname,
418 			     const char *string)
419 {
420 	const struct property *prop = of_find_property(np, propname, NULL);
421 	size_t l;
422 	int i;
423 	const char *p, *end;
424 
425 	if (!prop)
426 		return -EINVAL;
427 	if (!prop->value)
428 		return -ENODATA;
429 
430 	p = prop->value;
431 	end = p + prop->length;
432 
433 	for (i = 0; p < end; i++, p += l) {
434 		l = strnlen(p, end - p) + 1;
435 		if (p + l > end)
436 			return -EILSEQ;
437 		pr_debug("comparing %s with %s\n", string, p);
438 		if (strcmp(string, p) == 0)
439 			return i; /* Found it; return index */
440 	}
441 	return -ENODATA;
442 }
443 EXPORT_SYMBOL_GPL(of_property_match_string);
444 
445 /**
446  * of_property_read_string_helper() - Utility helper for parsing string properties
447  * @np:		device node from which the property value is to be read.
448  * @propname:	name of the property to be searched.
449  * @out_strs:	output array of string pointers.
450  * @sz:		number of array elements to read.
451  * @skip:	Number of strings to skip over at beginning of list.
452  *
453  * Don't call this function directly. It is a utility helper for the
454  * of_property_read_string*() family of functions.
455  */
456 int of_property_read_string_helper(const struct device_node *np,
457 				   const char *propname, const char **out_strs,
458 				   size_t sz, int skip)
459 {
460 	const struct property *prop = of_find_property(np, propname, NULL);
461 	int l = 0, i = 0;
462 	const char *p, *end;
463 
464 	if (!prop)
465 		return -EINVAL;
466 	if (!prop->value)
467 		return -ENODATA;
468 	p = prop->value;
469 	end = p + prop->length;
470 
471 	for (i = 0; p < end && (!out_strs || i < skip + sz); i++, p += l) {
472 		l = strnlen(p, end - p) + 1;
473 		if (p + l > end)
474 			return -EILSEQ;
475 		if (out_strs && i >= skip)
476 			*out_strs++ = p;
477 	}
478 	i -= skip;
479 	return i <= 0 ? -ENODATA : i;
480 }
481 EXPORT_SYMBOL_GPL(of_property_read_string_helper);
482 
483 const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
484 			       u32 *pu)
485 {
486 	const void *curv = cur;
487 
488 	if (!prop)
489 		return NULL;
490 
491 	if (!cur) {
492 		curv = prop->value;
493 		goto out_val;
494 	}
495 
496 	curv += sizeof(*cur);
497 	if (curv >= prop->value + prop->length)
498 		return NULL;
499 
500 out_val:
501 	*pu = be32_to_cpup(curv);
502 	return curv;
503 }
504 EXPORT_SYMBOL_GPL(of_prop_next_u32);
505 
506 const char *of_prop_next_string(struct property *prop, const char *cur)
507 {
508 	const void *curv = cur;
509 
510 	if (!prop)
511 		return NULL;
512 
513 	if (!cur)
514 		return prop->value;
515 
516 	curv += strlen(cur) + 1;
517 	if (curv >= prop->value + prop->length)
518 		return NULL;
519 
520 	return curv;
521 }
522 EXPORT_SYMBOL_GPL(of_prop_next_string);
523 
524 /**
525  * of_graph_parse_endpoint() - parse common endpoint node properties
526  * @node: pointer to endpoint device_node
527  * @endpoint: pointer to the OF endpoint data structure
528  *
529  * The caller should hold a reference to @node.
530  */
531 int of_graph_parse_endpoint(const struct device_node *node,
532 			    struct of_endpoint *endpoint)
533 {
534 	struct device_node *port_node = of_get_parent(node);
535 
536 	WARN_ONCE(!port_node, "%s(): endpoint %pOF has no parent node\n",
537 		  __func__, node);
538 
539 	memset(endpoint, 0, sizeof(*endpoint));
540 
541 	endpoint->local_node = node;
542 	/*
543 	 * It doesn't matter whether the two calls below succeed.
544 	 * If they don't then the default value 0 is used.
545 	 */
546 	of_property_read_u32(port_node, "reg", &endpoint->port);
547 	of_property_read_u32(node, "reg", &endpoint->id);
548 
549 	of_node_put(port_node);
550 
551 	return 0;
552 }
553 EXPORT_SYMBOL(of_graph_parse_endpoint);
554 
555 /**
556  * of_graph_get_port_by_id() - get the port matching a given id
557  * @parent: pointer to the parent device node
558  * @id: id of the port
559  *
560  * Return: A 'port' node pointer with refcount incremented. The caller
561  * has to use of_node_put() on it when done.
562  */
563 struct device_node *of_graph_get_port_by_id(struct device_node *parent, u32 id)
564 {
565 	struct device_node *node, *port;
566 
567 	node = of_get_child_by_name(parent, "ports");
568 	if (node)
569 		parent = node;
570 
571 	for_each_child_of_node(parent, port) {
572 		u32 port_id = 0;
573 
574 		if (!of_node_name_eq(port, "port"))
575 			continue;
576 		of_property_read_u32(port, "reg", &port_id);
577 		if (id == port_id)
578 			break;
579 	}
580 
581 	of_node_put(node);
582 
583 	return port;
584 }
585 EXPORT_SYMBOL(of_graph_get_port_by_id);
586 
587 /**
588  * of_graph_get_next_endpoint() - get next endpoint node
589  * @parent: pointer to the parent device node
590  * @prev: previous endpoint node, or NULL to get first
591  *
592  * Return: An 'endpoint' node pointer with refcount incremented. Refcount
593  * of the passed @prev node is decremented.
594  */
595 struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
596 					struct device_node *prev)
597 {
598 	struct device_node *endpoint;
599 	struct device_node *port;
600 
601 	if (!parent)
602 		return NULL;
603 
604 	/*
605 	 * Start by locating the port node. If no previous endpoint is specified
606 	 * search for the first port node, otherwise get the previous endpoint
607 	 * parent port node.
608 	 */
609 	if (!prev) {
610 		struct device_node *node;
611 
612 		node = of_get_child_by_name(parent, "ports");
613 		if (node)
614 			parent = node;
615 
616 		port = of_get_child_by_name(parent, "port");
617 		of_node_put(node);
618 
619 		if (!port) {
620 			pr_err("graph: no port node found in %pOF\n", parent);
621 			return NULL;
622 		}
623 	} else {
624 		port = of_get_parent(prev);
625 		if (WARN_ONCE(!port, "%s(): endpoint %pOF has no parent node\n",
626 			      __func__, prev))
627 			return NULL;
628 	}
629 
630 	while (1) {
631 		/*
632 		 * Now that we have a port node, get the next endpoint by
633 		 * getting the next child. If the previous endpoint is NULL this
634 		 * will return the first child.
635 		 */
636 		endpoint = of_get_next_child(port, prev);
637 		if (endpoint) {
638 			of_node_put(port);
639 			return endpoint;
640 		}
641 
642 		/* No more endpoints under this port, try the next one. */
643 		prev = NULL;
644 
645 		do {
646 			port = of_get_next_child(parent, port);
647 			if (!port)
648 				return NULL;
649 		} while (!of_node_name_eq(port, "port"));
650 	}
651 }
652 EXPORT_SYMBOL(of_graph_get_next_endpoint);
653 
654 /**
655  * of_graph_get_endpoint_by_regs() - get endpoint node of specific identifiers
656  * @parent: pointer to the parent device node
657  * @port_reg: identifier (value of reg property) of the parent port node
658  * @reg: identifier (value of reg property) of the endpoint node
659  *
660  * Return: An 'endpoint' node pointer which is identified by reg and at the same
661  * is the child of a port node identified by port_reg. reg and port_reg are
662  * ignored when they are -1. Use of_node_put() on the pointer when done.
663  */
664 struct device_node *of_graph_get_endpoint_by_regs(
665 	const struct device_node *parent, int port_reg, int reg)
666 {
667 	struct of_endpoint endpoint;
668 	struct device_node *node = NULL;
669 
670 	for_each_endpoint_of_node(parent, node) {
671 		of_graph_parse_endpoint(node, &endpoint);
672 		if (((port_reg == -1) || (endpoint.port == port_reg)) &&
673 			((reg == -1) || (endpoint.id == reg)))
674 			return node;
675 	}
676 
677 	return NULL;
678 }
679 EXPORT_SYMBOL(of_graph_get_endpoint_by_regs);
680 
681 /**
682  * of_graph_get_remote_endpoint() - get remote endpoint node
683  * @node: pointer to a local endpoint device_node
684  *
685  * Return: Remote endpoint node associated with remote endpoint node linked
686  *	   to @node. Use of_node_put() on it when done.
687  */
688 struct device_node *of_graph_get_remote_endpoint(const struct device_node *node)
689 {
690 	/* Get remote endpoint node. */
691 	return of_parse_phandle(node, "remote-endpoint", 0);
692 }
693 EXPORT_SYMBOL(of_graph_get_remote_endpoint);
694 
695 /**
696  * of_graph_get_port_parent() - get port's parent node
697  * @node: pointer to a local endpoint device_node
698  *
699  * Return: device node associated with endpoint node linked
700  *	   to @node. Use of_node_put() on it when done.
701  */
702 struct device_node *of_graph_get_port_parent(struct device_node *node)
703 {
704 	unsigned int depth;
705 
706 	if (!node)
707 		return NULL;
708 
709 	/*
710 	 * Preserve usecount for passed in node as of_get_next_parent()
711 	 * will do of_node_put() on it.
712 	 */
713 	of_node_get(node);
714 
715 	/* Walk 3 levels up only if there is 'ports' node. */
716 	for (depth = 3; depth && node; depth--) {
717 		node = of_get_next_parent(node);
718 		if (depth == 2 && !of_node_name_eq(node, "ports"))
719 			break;
720 	}
721 	return node;
722 }
723 EXPORT_SYMBOL(of_graph_get_port_parent);
724 
725 /**
726  * of_graph_get_remote_port_parent() - get remote port's parent node
727  * @node: pointer to a local endpoint device_node
728  *
729  * Return: Remote device node associated with remote endpoint node linked
730  *	   to @node. Use of_node_put() on it when done.
731  */
732 struct device_node *of_graph_get_remote_port_parent(
733 			       const struct device_node *node)
734 {
735 	struct device_node *np, *pp;
736 
737 	/* Get remote endpoint node. */
738 	np = of_graph_get_remote_endpoint(node);
739 
740 	pp = of_graph_get_port_parent(np);
741 
742 	of_node_put(np);
743 
744 	return pp;
745 }
746 EXPORT_SYMBOL(of_graph_get_remote_port_parent);
747 
748 /**
749  * of_graph_get_remote_port() - get remote port node
750  * @node: pointer to a local endpoint device_node
751  *
752  * Return: Remote port node associated with remote endpoint node linked
753  *	   to @node. Use of_node_put() on it when done.
754  */
755 struct device_node *of_graph_get_remote_port(const struct device_node *node)
756 {
757 	struct device_node *np;
758 
759 	/* Get remote endpoint node. */
760 	np = of_graph_get_remote_endpoint(node);
761 	if (!np)
762 		return NULL;
763 	return of_get_next_parent(np);
764 }
765 EXPORT_SYMBOL(of_graph_get_remote_port);
766 
767 int of_graph_get_endpoint_count(const struct device_node *np)
768 {
769 	struct device_node *endpoint;
770 	int num = 0;
771 
772 	for_each_endpoint_of_node(np, endpoint)
773 		num++;
774 
775 	return num;
776 }
777 EXPORT_SYMBOL(of_graph_get_endpoint_count);
778 
779 /**
780  * of_graph_get_remote_node() - get remote parent device_node for given port/endpoint
781  * @node: pointer to parent device_node containing graph port/endpoint
782  * @port: identifier (value of reg property) of the parent port node
783  * @endpoint: identifier (value of reg property) of the endpoint node
784  *
785  * Return: Remote device node associated with remote endpoint node linked
786  *	   to @node. Use of_node_put() on it when done.
787  */
788 struct device_node *of_graph_get_remote_node(const struct device_node *node,
789 					     u32 port, u32 endpoint)
790 {
791 	struct device_node *endpoint_node, *remote;
792 
793 	endpoint_node = of_graph_get_endpoint_by_regs(node, port, endpoint);
794 	if (!endpoint_node) {
795 		pr_debug("no valid endpoint (%d, %d) for node %pOF\n",
796 			 port, endpoint, node);
797 		return NULL;
798 	}
799 
800 	remote = of_graph_get_remote_port_parent(endpoint_node);
801 	of_node_put(endpoint_node);
802 	if (!remote) {
803 		pr_debug("no valid remote node\n");
804 		return NULL;
805 	}
806 
807 	if (!of_device_is_available(remote)) {
808 		pr_debug("not available for remote node\n");
809 		of_node_put(remote);
810 		return NULL;
811 	}
812 
813 	return remote;
814 }
815 EXPORT_SYMBOL(of_graph_get_remote_node);
816 
817 static struct fwnode_handle *of_fwnode_get(struct fwnode_handle *fwnode)
818 {
819 	return of_fwnode_handle(of_node_get(to_of_node(fwnode)));
820 }
821 
822 static void of_fwnode_put(struct fwnode_handle *fwnode)
823 {
824 	of_node_put(to_of_node(fwnode));
825 }
826 
827 static bool of_fwnode_device_is_available(const struct fwnode_handle *fwnode)
828 {
829 	return of_device_is_available(to_of_node(fwnode));
830 }
831 
832 static bool of_fwnode_property_present(const struct fwnode_handle *fwnode,
833 				       const char *propname)
834 {
835 	return of_property_read_bool(to_of_node(fwnode), propname);
836 }
837 
838 static int of_fwnode_property_read_int_array(const struct fwnode_handle *fwnode,
839 					     const char *propname,
840 					     unsigned int elem_size, void *val,
841 					     size_t nval)
842 {
843 	const struct device_node *node = to_of_node(fwnode);
844 
845 	if (!val)
846 		return of_property_count_elems_of_size(node, propname,
847 						       elem_size);
848 
849 	switch (elem_size) {
850 	case sizeof(u8):
851 		return of_property_read_u8_array(node, propname, val, nval);
852 	case sizeof(u16):
853 		return of_property_read_u16_array(node, propname, val, nval);
854 	case sizeof(u32):
855 		return of_property_read_u32_array(node, propname, val, nval);
856 	case sizeof(u64):
857 		return of_property_read_u64_array(node, propname, val, nval);
858 	}
859 
860 	return -ENXIO;
861 }
862 
863 static int
864 of_fwnode_property_read_string_array(const struct fwnode_handle *fwnode,
865 				     const char *propname, const char **val,
866 				     size_t nval)
867 {
868 	const struct device_node *node = to_of_node(fwnode);
869 
870 	return val ?
871 		of_property_read_string_array(node, propname, val, nval) :
872 		of_property_count_strings(node, propname);
873 }
874 
875 static struct fwnode_handle *
876 of_fwnode_get_parent(const struct fwnode_handle *fwnode)
877 {
878 	return of_fwnode_handle(of_get_parent(to_of_node(fwnode)));
879 }
880 
881 static struct fwnode_handle *
882 of_fwnode_get_next_child_node(const struct fwnode_handle *fwnode,
883 			      struct fwnode_handle *child)
884 {
885 	return of_fwnode_handle(of_get_next_available_child(to_of_node(fwnode),
886 							    to_of_node(child)));
887 }
888 
889 static struct fwnode_handle *
890 of_fwnode_get_named_child_node(const struct fwnode_handle *fwnode,
891 			       const char *childname)
892 {
893 	const struct device_node *node = to_of_node(fwnode);
894 	struct device_node *child;
895 
896 	for_each_available_child_of_node(node, child)
897 		if (of_node_name_eq(child, childname))
898 			return of_fwnode_handle(child);
899 
900 	return NULL;
901 }
902 
903 static int
904 of_fwnode_get_reference_args(const struct fwnode_handle *fwnode,
905 			     const char *prop, const char *nargs_prop,
906 			     unsigned int nargs, unsigned int index,
907 			     struct fwnode_reference_args *args)
908 {
909 	struct of_phandle_args of_args;
910 	unsigned int i;
911 	int ret;
912 
913 	if (nargs_prop)
914 		ret = of_parse_phandle_with_args(to_of_node(fwnode), prop,
915 						 nargs_prop, index, &of_args);
916 	else
917 		ret = of_parse_phandle_with_fixed_args(to_of_node(fwnode), prop,
918 						       nargs, index, &of_args);
919 	if (ret < 0)
920 		return ret;
921 	if (!args)
922 		return 0;
923 
924 	args->nargs = of_args.args_count;
925 	args->fwnode = of_fwnode_handle(of_args.np);
926 
927 	for (i = 0; i < NR_FWNODE_REFERENCE_ARGS; i++)
928 		args->args[i] = i < of_args.args_count ? of_args.args[i] : 0;
929 
930 	return 0;
931 }
932 
933 static struct fwnode_handle *
934 of_fwnode_graph_get_next_endpoint(const struct fwnode_handle *fwnode,
935 				  struct fwnode_handle *prev)
936 {
937 	return of_fwnode_handle(of_graph_get_next_endpoint(to_of_node(fwnode),
938 							   to_of_node(prev)));
939 }
940 
941 static struct fwnode_handle *
942 of_fwnode_graph_get_remote_endpoint(const struct fwnode_handle *fwnode)
943 {
944 	return of_fwnode_handle(
945 		of_graph_get_remote_endpoint(to_of_node(fwnode)));
946 }
947 
948 static struct fwnode_handle *
949 of_fwnode_graph_get_port_parent(struct fwnode_handle *fwnode)
950 {
951 	struct device_node *np;
952 
953 	/* Get the parent of the port */
954 	np = of_get_parent(to_of_node(fwnode));
955 	if (!np)
956 		return NULL;
957 
958 	/* Is this the "ports" node? If not, it's the port parent. */
959 	if (!of_node_name_eq(np, "ports"))
960 		return of_fwnode_handle(np);
961 
962 	return of_fwnode_handle(of_get_next_parent(np));
963 }
964 
965 static int of_fwnode_graph_parse_endpoint(const struct fwnode_handle *fwnode,
966 					  struct fwnode_endpoint *endpoint)
967 {
968 	const struct device_node *node = to_of_node(fwnode);
969 	struct device_node *port_node = of_get_parent(node);
970 
971 	endpoint->local_fwnode = fwnode;
972 
973 	of_property_read_u32(port_node, "reg", &endpoint->port);
974 	of_property_read_u32(node, "reg", &endpoint->id);
975 
976 	of_node_put(port_node);
977 
978 	return 0;
979 }
980 
981 static const void *
982 of_fwnode_device_get_match_data(const struct fwnode_handle *fwnode,
983 				const struct device *dev)
984 {
985 	return of_device_get_match_data(dev);
986 }
987 
988 const struct fwnode_operations of_fwnode_ops = {
989 	.get = of_fwnode_get,
990 	.put = of_fwnode_put,
991 	.device_is_available = of_fwnode_device_is_available,
992 	.device_get_match_data = of_fwnode_device_get_match_data,
993 	.property_present = of_fwnode_property_present,
994 	.property_read_int_array = of_fwnode_property_read_int_array,
995 	.property_read_string_array = of_fwnode_property_read_string_array,
996 	.get_parent = of_fwnode_get_parent,
997 	.get_next_child_node = of_fwnode_get_next_child_node,
998 	.get_named_child_node = of_fwnode_get_named_child_node,
999 	.get_reference_args = of_fwnode_get_reference_args,
1000 	.graph_get_next_endpoint = of_fwnode_graph_get_next_endpoint,
1001 	.graph_get_remote_endpoint = of_fwnode_graph_get_remote_endpoint,
1002 	.graph_get_port_parent = of_fwnode_graph_get_port_parent,
1003 	.graph_parse_endpoint = of_fwnode_graph_parse_endpoint,
1004 };
1005 EXPORT_SYMBOL_GPL(of_fwnode_ops);
1006