xref: /linux/drivers/base/property.c (revision e2683c8868d03382da7e1ce8453b543a043066d1)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * property.c - Unified device property interface.
4  *
5  * Copyright (C) 2014, Intel Corporation
6  * Authors: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
7  *          Mika Westerberg <mika.westerberg@linux.intel.com>
8  */
9 
10 #include <linux/device.h>
11 #include <linux/err.h>
12 #include <linux/export.h>
13 #include <linux/kconfig.h>
14 #include <linux/of.h>
15 #include <linux/property.h>
16 #include <linux/phy.h>
17 #include <linux/slab.h>
18 #include <linux/string.h>
19 #include <linux/types.h>
20 
21 struct fwnode_handle *__dev_fwnode(struct device *dev)
22 {
23 	return IS_ENABLED(CONFIG_OF) && dev->of_node ?
24 		of_fwnode_handle(dev->of_node) : dev->fwnode;
25 }
26 EXPORT_SYMBOL_GPL(__dev_fwnode);
27 
28 const struct fwnode_handle *__dev_fwnode_const(const struct device *dev)
29 {
30 	return IS_ENABLED(CONFIG_OF) && dev->of_node ?
31 		of_fwnode_handle(dev->of_node) : dev->fwnode;
32 }
33 EXPORT_SYMBOL_GPL(__dev_fwnode_const);
34 
35 /**
36  * device_property_present - check if a property of a device is present
37  * @dev: Device whose property is being checked
38  * @propname: Name of the property
39  *
40  * Check if property @propname is present in the device firmware description.
41  * This function is the unambiguous way to check that given property is present
42  * in the device firmware description.
43  *
44  * Return: true if property @propname is present. Otherwise, returns false.
45  */
46 bool device_property_present(const struct device *dev, const char *propname)
47 {
48 	return fwnode_property_present(dev_fwnode(dev), propname);
49 }
50 EXPORT_SYMBOL_GPL(device_property_present);
51 
52 /**
53  * fwnode_property_present - check if a property of a firmware node is present
54  * @fwnode: Firmware node whose property to check
55  * @propname: Name of the property
56  *
57  * Check if property @propname is present in the firmware node description.
58  * This function is the unambiguous way to check that given property is present
59  * in the firmware node description.
60  *
61  * Return: true if property @propname is present. Otherwise, returns false.
62  */
63 bool fwnode_property_present(const struct fwnode_handle *fwnode,
64 			     const char *propname)
65 {
66 	bool ret;
67 
68 	if (IS_ERR_OR_NULL(fwnode))
69 		return false;
70 
71 	ret = fwnode_call_bool_op(fwnode, property_present, propname);
72 	if (ret)
73 		return ret;
74 
75 	return fwnode_call_bool_op(fwnode->secondary, property_present, propname);
76 }
77 EXPORT_SYMBOL_GPL(fwnode_property_present);
78 
79 /**
80  * device_property_read_bool - Return the value for a boolean property of a device
81  * @dev: Device whose property is being checked
82  * @propname: Name of the property
83  *
84  * Use device_property_present() to check for the property presence.
85  *
86  * Return: if property @propname is true or false in the device firmware description.
87  */
88 bool device_property_read_bool(const struct device *dev, const char *propname)
89 {
90 	return fwnode_property_read_bool(dev_fwnode(dev), propname);
91 }
92 EXPORT_SYMBOL_GPL(device_property_read_bool);
93 
94 /**
95  * fwnode_property_read_bool - Return the value for a boolean property of a firmware node
96  * @fwnode: Firmware node whose property to check
97  * @propname: Name of the property
98  *
99  * Use fwnode_property_present() to check for the property presence.
100  *
101  * Return: if property @propname is true or false in the firmware node description.
102  */
103 bool fwnode_property_read_bool(const struct fwnode_handle *fwnode,
104 			     const char *propname)
105 {
106 	bool ret;
107 
108 	if (IS_ERR_OR_NULL(fwnode))
109 		return false;
110 
111 	ret = fwnode_call_bool_op(fwnode, property_read_bool, propname);
112 	if (ret)
113 		return ret;
114 
115 	return fwnode_call_bool_op(fwnode->secondary, property_read_bool, propname);
116 }
117 EXPORT_SYMBOL_GPL(fwnode_property_read_bool);
118 
119 /**
120  * device_property_read_u8_array - return a u8 array property of a device
121  * @dev: Device to get the property of
122  * @propname: Name of the property
123  * @val: The values are stored here or %NULL to return the number of values
124  * @nval: Size of the @val array
125  *
126  * Function reads an array of u8 properties with @propname from the device
127  * firmware description and stores them to @val if found.
128  *
129  * It's recommended to call device_property_count_u8() instead of calling
130  * this function with @val equals %NULL and @nval equals 0.
131  *
132  * Return: number of values if @val was %NULL,
133  *         %0 if the property was found (success),
134  *	   %-EINVAL if given arguments are not valid,
135  *	   %-ENODATA if the property does not have a value,
136  *	   %-EPROTO if the property is not an array of numbers,
137  *	   %-EOVERFLOW if the size of the property is not as expected.
138  *	   %-ENXIO if no suitable firmware interface is present.
139  */
140 int device_property_read_u8_array(const struct device *dev, const char *propname,
141 				  u8 *val, size_t nval)
142 {
143 	return fwnode_property_read_u8_array(dev_fwnode(dev), propname, val, nval);
144 }
145 EXPORT_SYMBOL_GPL(device_property_read_u8_array);
146 
147 /**
148  * device_property_read_u16_array - return a u16 array property of a device
149  * @dev: Device to get the property of
150  * @propname: Name of the property
151  * @val: The values are stored here or %NULL to return the number of values
152  * @nval: Size of the @val array
153  *
154  * Function reads an array of u16 properties with @propname from the device
155  * firmware description and stores them to @val if found.
156  *
157  * It's recommended to call device_property_count_u16() instead of calling
158  * this function with @val equals %NULL and @nval equals 0.
159  *
160  * Return: number of values if @val was %NULL,
161  *         %0 if the property was found (success),
162  *	   %-EINVAL if given arguments are not valid,
163  *	   %-ENODATA if the property does not have a value,
164  *	   %-EPROTO if the property is not an array of numbers,
165  *	   %-EOVERFLOW if the size of the property is not as expected.
166  *	   %-ENXIO if no suitable firmware interface is present.
167  */
168 int device_property_read_u16_array(const struct device *dev, const char *propname,
169 				   u16 *val, size_t nval)
170 {
171 	return fwnode_property_read_u16_array(dev_fwnode(dev), propname, val, nval);
172 }
173 EXPORT_SYMBOL_GPL(device_property_read_u16_array);
174 
175 /**
176  * device_property_read_u32_array - return a u32 array property of a device
177  * @dev: Device to get the property of
178  * @propname: Name of the property
179  * @val: The values are stored here or %NULL to return the number of values
180  * @nval: Size of the @val array
181  *
182  * Function reads an array of u32 properties with @propname from the device
183  * firmware description and stores them to @val if found.
184  *
185  * It's recommended to call device_property_count_u32() instead of calling
186  * this function with @val equals %NULL and @nval equals 0.
187  *
188  * Return: number of values if @val was %NULL,
189  *         %0 if the property was found (success),
190  *	   %-EINVAL if given arguments are not valid,
191  *	   %-ENODATA if the property does not have a value,
192  *	   %-EPROTO if the property is not an array of numbers,
193  *	   %-EOVERFLOW if the size of the property is not as expected.
194  *	   %-ENXIO if no suitable firmware interface is present.
195  */
196 int device_property_read_u32_array(const struct device *dev, const char *propname,
197 				   u32 *val, size_t nval)
198 {
199 	return fwnode_property_read_u32_array(dev_fwnode(dev), propname, val, nval);
200 }
201 EXPORT_SYMBOL_GPL(device_property_read_u32_array);
202 
203 /**
204  * device_property_read_u64_array - return a u64 array property of a device
205  * @dev: Device to get the property of
206  * @propname: Name of the property
207  * @val: The values are stored here or %NULL to return the number of values
208  * @nval: Size of the @val array
209  *
210  * Function reads an array of u64 properties with @propname from the device
211  * firmware description and stores them to @val if found.
212  *
213  * It's recommended to call device_property_count_u64() instead of calling
214  * this function with @val equals %NULL and @nval equals 0.
215  *
216  * Return: number of values if @val was %NULL,
217  *         %0 if the property was found (success),
218  *	   %-EINVAL if given arguments are not valid,
219  *	   %-ENODATA if the property does not have a value,
220  *	   %-EPROTO if the property is not an array of numbers,
221  *	   %-EOVERFLOW if the size of the property is not as expected.
222  *	   %-ENXIO if no suitable firmware interface is present.
223  */
224 int device_property_read_u64_array(const struct device *dev, const char *propname,
225 				   u64 *val, size_t nval)
226 {
227 	return fwnode_property_read_u64_array(dev_fwnode(dev), propname, val, nval);
228 }
229 EXPORT_SYMBOL_GPL(device_property_read_u64_array);
230 
231 /**
232  * device_property_read_string_array - return a string array property of device
233  * @dev: Device to get the property of
234  * @propname: Name of the property
235  * @val: The values are stored here or %NULL to return the number of values
236  * @nval: Size of the @val array
237  *
238  * Function reads an array of string properties with @propname from the device
239  * firmware description and stores them to @val if found.
240  *
241  * It's recommended to call device_property_string_array_count() instead of calling
242  * this function with @val equals %NULL and @nval equals 0.
243  *
244  * Return: number of values read on success if @val is non-NULL,
245  *	   number of values available on success if @val is NULL,
246  *	   %-EINVAL if given arguments are not valid,
247  *	   %-ENODATA if the property does not have a value,
248  *	   %-EPROTO or %-EILSEQ if the property is not an array of strings,
249  *	   %-EOVERFLOW if the size of the property is not as expected.
250  *	   %-ENXIO if no suitable firmware interface is present.
251  */
252 int device_property_read_string_array(const struct device *dev, const char *propname,
253 				      const char **val, size_t nval)
254 {
255 	return fwnode_property_read_string_array(dev_fwnode(dev), propname, val, nval);
256 }
257 EXPORT_SYMBOL_GPL(device_property_read_string_array);
258 
259 /**
260  * device_property_read_string - return a string property of a device
261  * @dev: Device to get the property of
262  * @propname: Name of the property
263  * @val: The value is stored here
264  *
265  * Function reads property @propname from the device firmware description and
266  * stores the value into @val if found. The value is checked to be a string.
267  *
268  * Return: %0 if the property was found (success),
269  *	   %-EINVAL if given arguments are not valid,
270  *	   %-ENODATA if the property does not have a value,
271  *	   %-EPROTO or %-EILSEQ if the property type is not a string.
272  *	   %-ENXIO if no suitable firmware interface is present.
273  */
274 int device_property_read_string(const struct device *dev, const char *propname,
275 				const char **val)
276 {
277 	return fwnode_property_read_string(dev_fwnode(dev), propname, val);
278 }
279 EXPORT_SYMBOL_GPL(device_property_read_string);
280 
281 /**
282  * device_property_match_string - find a string in an array and return index
283  * @dev: Device to get the property of
284  * @propname: Name of the property holding the array
285  * @string: String to look for
286  *
287  * Find a given string in a string array and if it is found return the
288  * index back.
289  *
290  * Return: index, starting from %0, if the property was found (success),
291  *	   %-EINVAL if given arguments are not valid,
292  *	   %-ENODATA if the property does not have a value,
293  *	   %-EPROTO if the property is not an array of strings,
294  *	   %-ENXIO if no suitable firmware interface is present.
295  */
296 int device_property_match_string(const struct device *dev, const char *propname,
297 				 const char *string)
298 {
299 	return fwnode_property_match_string(dev_fwnode(dev), propname, string);
300 }
301 EXPORT_SYMBOL_GPL(device_property_match_string);
302 
303 static int fwnode_property_read_int_array(const struct fwnode_handle *fwnode,
304 					  const char *propname,
305 					  unsigned int elem_size, void *val,
306 					  size_t nval)
307 {
308 	int ret;
309 
310 	if (IS_ERR_OR_NULL(fwnode))
311 		return -EINVAL;
312 
313 	ret = fwnode_call_int_op(fwnode, property_read_int_array, propname,
314 				 elem_size, val, nval);
315 	if (ret != -EINVAL)
316 		return ret;
317 
318 	return fwnode_call_int_op(fwnode->secondary, property_read_int_array, propname,
319 				  elem_size, val, nval);
320 }
321 
322 /**
323  * fwnode_property_read_u8_array - return a u8 array property of firmware node
324  * @fwnode: Firmware node to get the property of
325  * @propname: Name of the property
326  * @val: The values are stored here or %NULL to return the number of values
327  * @nval: Size of the @val array
328  *
329  * Read an array of u8 properties with @propname from @fwnode and stores them to
330  * @val if found.
331  *
332  * It's recommended to call fwnode_property_count_u8() instead of calling
333  * this function with @val equals %NULL and @nval equals 0.
334  *
335  * Return: number of values if @val was %NULL,
336  *         %0 if the property was found (success),
337  *	   %-EINVAL if given arguments are not valid,
338  *	   %-ENODATA if the property does not have a value,
339  *	   %-EPROTO if the property is not an array of numbers,
340  *	   %-EOVERFLOW if the size of the property is not as expected,
341  *	   %-ENXIO if no suitable firmware interface is present.
342  */
343 int fwnode_property_read_u8_array(const struct fwnode_handle *fwnode,
344 				  const char *propname, u8 *val, size_t nval)
345 {
346 	return fwnode_property_read_int_array(fwnode, propname, sizeof(u8),
347 					      val, nval);
348 }
349 EXPORT_SYMBOL_GPL(fwnode_property_read_u8_array);
350 
351 /**
352  * fwnode_property_read_u16_array - return a u16 array property of firmware node
353  * @fwnode: Firmware node to get the property of
354  * @propname: Name of the property
355  * @val: The values are stored here or %NULL to return the number of values
356  * @nval: Size of the @val array
357  *
358  * Read an array of u16 properties with @propname from @fwnode and store them to
359  * @val if found.
360  *
361  * It's recommended to call fwnode_property_count_u16() instead of calling
362  * this function with @val equals %NULL and @nval equals 0.
363  *
364  * Return: number of values if @val was %NULL,
365  *         %0 if the property was found (success),
366  *	   %-EINVAL if given arguments are not valid,
367  *	   %-ENODATA if the property does not have a value,
368  *	   %-EPROTO if the property is not an array of numbers,
369  *	   %-EOVERFLOW if the size of the property is not as expected,
370  *	   %-ENXIO if no suitable firmware interface is present.
371  */
372 int fwnode_property_read_u16_array(const struct fwnode_handle *fwnode,
373 				   const char *propname, u16 *val, size_t nval)
374 {
375 	return fwnode_property_read_int_array(fwnode, propname, sizeof(u16),
376 					      val, nval);
377 }
378 EXPORT_SYMBOL_GPL(fwnode_property_read_u16_array);
379 
380 /**
381  * fwnode_property_read_u32_array - return a u32 array property of firmware node
382  * @fwnode: Firmware node to get the property of
383  * @propname: Name of the property
384  * @val: The values are stored here or %NULL to return the number of values
385  * @nval: Size of the @val array
386  *
387  * Read an array of u32 properties with @propname from @fwnode store them to
388  * @val if found.
389  *
390  * It's recommended to call fwnode_property_count_u32() instead of calling
391  * this function with @val equals %NULL and @nval equals 0.
392  *
393  * Return: number of values if @val was %NULL,
394  *         %0 if the property was found (success),
395  *	   %-EINVAL if given arguments are not valid,
396  *	   %-ENODATA if the property does not have a value,
397  *	   %-EPROTO if the property is not an array of numbers,
398  *	   %-EOVERFLOW if the size of the property is not as expected,
399  *	   %-ENXIO if no suitable firmware interface is present.
400  */
401 int fwnode_property_read_u32_array(const struct fwnode_handle *fwnode,
402 				   const char *propname, u32 *val, size_t nval)
403 {
404 	return fwnode_property_read_int_array(fwnode, propname, sizeof(u32),
405 					      val, nval);
406 }
407 EXPORT_SYMBOL_GPL(fwnode_property_read_u32_array);
408 
409 /**
410  * fwnode_property_read_u64_array - return a u64 array property firmware node
411  * @fwnode: Firmware node to get the property of
412  * @propname: Name of the property
413  * @val: The values are stored here or %NULL to return the number of values
414  * @nval: Size of the @val array
415  *
416  * Read an array of u64 properties with @propname from @fwnode and store them to
417  * @val if found.
418  *
419  * It's recommended to call fwnode_property_count_u64() instead of calling
420  * this function with @val equals %NULL and @nval equals 0.
421  *
422  * Return: number of values if @val was %NULL,
423  *         %0 if the property was found (success),
424  *	   %-EINVAL if given arguments are not valid,
425  *	   %-ENODATA if the property does not have a value,
426  *	   %-EPROTO if the property is not an array of numbers,
427  *	   %-EOVERFLOW if the size of the property is not as expected,
428  *	   %-ENXIO if no suitable firmware interface is present.
429  */
430 int fwnode_property_read_u64_array(const struct fwnode_handle *fwnode,
431 				   const char *propname, u64 *val, size_t nval)
432 {
433 	return fwnode_property_read_int_array(fwnode, propname, sizeof(u64),
434 					      val, nval);
435 }
436 EXPORT_SYMBOL_GPL(fwnode_property_read_u64_array);
437 
438 /**
439  * fwnode_property_read_string_array - return string array property of a node
440  * @fwnode: Firmware node to get the property of
441  * @propname: Name of the property
442  * @val: The values are stored here or %NULL to return the number of values
443  * @nval: Size of the @val array
444  *
445  * Read an string list property @propname from the given firmware node and store
446  * them to @val if found.
447  *
448  * It's recommended to call fwnode_property_string_array_count() instead of calling
449  * this function with @val equals %NULL and @nval equals 0.
450  *
451  * Return: number of values read on success if @val is non-NULL,
452  *	   number of values available on success if @val is NULL,
453  *	   %-EINVAL if given arguments are not valid,
454  *	   %-ENODATA if the property does not have a value,
455  *	   %-EPROTO or %-EILSEQ if the property is not an array of strings,
456  *	   %-EOVERFLOW if the size of the property is not as expected,
457  *	   %-ENXIO if no suitable firmware interface is present.
458  */
459 int fwnode_property_read_string_array(const struct fwnode_handle *fwnode,
460 				      const char *propname, const char **val,
461 				      size_t nval)
462 {
463 	int ret;
464 
465 	if (IS_ERR_OR_NULL(fwnode))
466 		return -EINVAL;
467 
468 	ret = fwnode_call_int_op(fwnode, property_read_string_array, propname,
469 				 val, nval);
470 	if (ret != -EINVAL)
471 		return ret;
472 
473 	return fwnode_call_int_op(fwnode->secondary, property_read_string_array, propname,
474 				  val, nval);
475 }
476 EXPORT_SYMBOL_GPL(fwnode_property_read_string_array);
477 
478 /**
479  * fwnode_property_read_string - return a string property of a firmware node
480  * @fwnode: Firmware node to get the property of
481  * @propname: Name of the property
482  * @val: The value is stored here
483  *
484  * Read property @propname from the given firmware node and store the value into
485  * @val if found.  The value is checked to be a string.
486  *
487  * Return: %0 if the property was found (success),
488  *	   %-EINVAL if given arguments are not valid,
489  *	   %-ENODATA if the property does not have a value,
490  *	   %-EPROTO or %-EILSEQ if the property is not a string,
491  *	   %-ENXIO if no suitable firmware interface is present.
492  */
493 int fwnode_property_read_string(const struct fwnode_handle *fwnode,
494 				const char *propname, const char **val)
495 {
496 	int ret = fwnode_property_read_string_array(fwnode, propname, val, 1);
497 
498 	return ret < 0 ? ret : 0;
499 }
500 EXPORT_SYMBOL_GPL(fwnode_property_read_string);
501 
502 /**
503  * fwnode_property_match_string - find a string in an array and return index
504  * @fwnode: Firmware node to get the property of
505  * @propname: Name of the property holding the array
506  * @string: String to look for
507  *
508  * Find a given string in a string array and if it is found return the
509  * index back.
510  *
511  * Return: index, starting from %0, if the property was found (success),
512  *	   %-EINVAL if given arguments are not valid,
513  *	   %-ENODATA if the property does not have a value,
514  *	   %-EPROTO if the property is not an array of strings,
515  *	   %-ENXIO if no suitable firmware interface is present.
516  */
517 int fwnode_property_match_string(const struct fwnode_handle *fwnode,
518 	const char *propname, const char *string)
519 {
520 	const char **values;
521 	int nval, ret;
522 
523 	nval = fwnode_property_string_array_count(fwnode, propname);
524 	if (nval < 0)
525 		return nval;
526 
527 	if (nval == 0)
528 		return -ENODATA;
529 
530 	values = kcalloc(nval, sizeof(*values), GFP_KERNEL);
531 	if (!values)
532 		return -ENOMEM;
533 
534 	ret = fwnode_property_read_string_array(fwnode, propname, values, nval);
535 	if (ret < 0)
536 		goto out_free;
537 
538 	ret = match_string(values, nval, string);
539 	if (ret < 0)
540 		ret = -ENODATA;
541 
542 out_free:
543 	kfree(values);
544 	return ret;
545 }
546 EXPORT_SYMBOL_GPL(fwnode_property_match_string);
547 
548 /**
549  * fwnode_property_match_property_string - find a property string value in an array and return index
550  * @fwnode: Firmware node to get the property of
551  * @propname: Name of the property holding the string value
552  * @array: String array to search in
553  * @n: Size of the @array
554  *
555  * Find a property string value in a given @array and if it is found return
556  * the index back.
557  *
558  * Return: index, starting from %0, if the string value was found in the @array (success),
559  *	   %-ENOENT when the string value was not found in the @array,
560  *	   %-EINVAL if given arguments are not valid,
561  *	   %-ENODATA if the property does not have a value,
562  *	   %-EPROTO or %-EILSEQ if the property is not a string,
563  *	   %-ENXIO if no suitable firmware interface is present.
564  */
565 int fwnode_property_match_property_string(const struct fwnode_handle *fwnode,
566 	const char *propname, const char * const *array, size_t n)
567 {
568 	const char *string;
569 	int ret;
570 
571 	ret = fwnode_property_read_string(fwnode, propname, &string);
572 	if (ret)
573 		return ret;
574 
575 	ret = match_string(array, n, string);
576 	if (ret < 0)
577 		ret = -ENOENT;
578 
579 	return ret;
580 }
581 EXPORT_SYMBOL_GPL(fwnode_property_match_property_string);
582 
583 /**
584  * fwnode_property_get_reference_args() - Find a reference with arguments
585  * @fwnode:	Firmware node where to look for the reference
586  * @prop:	The name of the property
587  * @nargs_prop:	The name of the property telling the number of
588  *		arguments in the referred node. NULL if @nargs is known,
589  *		otherwise @nargs is ignored.
590  * @nargs:	Number of arguments. Ignored if @nargs_prop is non-NULL.
591  * @index:	Index of the reference, from zero onwards.
592  * @args:	Result structure with reference and integer arguments.
593  *		May be NULL.
594  *
595  * Obtain a reference based on a named property in an fwnode, with
596  * integer arguments.
597  *
598  * The caller is responsible for calling fwnode_handle_put() on the returned
599  * @args->fwnode pointer.
600  *
601  * Return: %0 on success
602  *	    %-ENOENT when the index is out of bounds, the index has an empty
603  *		     reference or the property was not found
604  *	    %-EINVAL on parse error
605  *	    %-ENOTCONN when the remote firmware node exists but has not been
606  *		       registered yet
607  */
608 int fwnode_property_get_reference_args(const struct fwnode_handle *fwnode,
609 				       const char *prop, const char *nargs_prop,
610 				       unsigned int nargs, unsigned int index,
611 				       struct fwnode_reference_args *args)
612 {
613 	int ret;
614 
615 	if (IS_ERR_OR_NULL(fwnode))
616 		return -ENOENT;
617 
618 	ret = fwnode_call_int_op(fwnode, get_reference_args, prop, nargs_prop,
619 				 nargs, index, args);
620 	if (ret == 0)
621 		return ret;
622 
623 	if (IS_ERR_OR_NULL(fwnode->secondary))
624 		return ret;
625 
626 	return fwnode_call_int_op(fwnode->secondary, get_reference_args, prop, nargs_prop,
627 				  nargs, index, args);
628 }
629 EXPORT_SYMBOL_GPL(fwnode_property_get_reference_args);
630 
631 /**
632  * fwnode_find_reference - Find named reference to a fwnode_handle
633  * @fwnode: Firmware node where to look for the reference
634  * @name: The name of the reference
635  * @index: Index of the reference
636  *
637  * @index can be used when the named reference holds a table of references.
638  *
639  * The caller is responsible for calling fwnode_handle_put() on the returned
640  * fwnode pointer.
641  *
642  * Return: a pointer to the reference fwnode, when found. Otherwise,
643  * returns an error pointer.
644  */
645 struct fwnode_handle *fwnode_find_reference(const struct fwnode_handle *fwnode,
646 					    const char *name,
647 					    unsigned int index)
648 {
649 	struct fwnode_reference_args args;
650 	int ret;
651 
652 	ret = fwnode_property_get_reference_args(fwnode, name, NULL, 0, index,
653 						 &args);
654 	return ret ? ERR_PTR(ret) : args.fwnode;
655 }
656 EXPORT_SYMBOL_GPL(fwnode_find_reference);
657 
658 /**
659  * fwnode_get_name - Return the name of a node
660  * @fwnode: The firmware node
661  *
662  * Return: a pointer to the node name, or %NULL.
663  */
664 const char *fwnode_get_name(const struct fwnode_handle *fwnode)
665 {
666 	return fwnode_call_ptr_op(fwnode, get_name);
667 }
668 EXPORT_SYMBOL_GPL(fwnode_get_name);
669 
670 /**
671  * fwnode_get_name_prefix - Return the prefix of node for printing purposes
672  * @fwnode: The firmware node
673  *
674  * Return: the prefix of a node, intended to be printed right before the node.
675  * The prefix works also as a separator between the nodes.
676  */
677 const char *fwnode_get_name_prefix(const struct fwnode_handle *fwnode)
678 {
679 	return fwnode_call_ptr_op(fwnode, get_name_prefix);
680 }
681 
682 /**
683  * fwnode_name_eq - Return true if node name is equal
684  * @fwnode: The firmware node
685  * @name: The name to which to compare the node name
686  *
687  * Compare the name provided as an argument to the name of the node, stopping
688  * the comparison at either NUL or '@' character, whichever comes first. This
689  * function is generally used for comparing node names while ignoring the
690  * possible unit address of the node.
691  *
692  * Return: true if the node name matches with the name provided in the @name
693  * argument, false otherwise.
694  */
695 bool fwnode_name_eq(const struct fwnode_handle *fwnode, const char *name)
696 {
697 	const char *node_name;
698 	ptrdiff_t len;
699 
700 	node_name = fwnode_get_name(fwnode);
701 	if (!node_name)
702 		return false;
703 
704 	len = strchrnul(node_name, '@') - node_name;
705 
706 	return str_has_prefix(node_name, name) == len;
707 }
708 EXPORT_SYMBOL_GPL(fwnode_name_eq);
709 
710 /**
711  * fwnode_get_parent - Return parent firwmare node
712  * @fwnode: Firmware whose parent is retrieved
713  *
714  * The caller is responsible for calling fwnode_handle_put() on the returned
715  * fwnode pointer.
716  *
717  * Return: parent firmware node of the given node if possible or %NULL if no
718  * parent was available.
719  */
720 struct fwnode_handle *fwnode_get_parent(const struct fwnode_handle *fwnode)
721 {
722 	return fwnode_call_ptr_op(fwnode, get_parent);
723 }
724 EXPORT_SYMBOL_GPL(fwnode_get_parent);
725 
726 /**
727  * fwnode_get_next_parent - Iterate to the node's parent
728  * @fwnode: Firmware whose parent is retrieved
729  *
730  * This is like fwnode_get_parent() except that it drops the refcount
731  * on the passed node, making it suitable for iterating through a
732  * node's parents.
733  *
734  * The caller is responsible for calling fwnode_handle_put() on the returned
735  * fwnode pointer. Note that this function also puts a reference to @fwnode
736  * unconditionally.
737  *
738  * Return: parent firmware node of the given node if possible or %NULL if no
739  * parent was available.
740  */
741 struct fwnode_handle *fwnode_get_next_parent(struct fwnode_handle *fwnode)
742 {
743 	struct fwnode_handle *parent = fwnode_get_parent(fwnode);
744 
745 	fwnode_handle_put(fwnode);
746 
747 	return parent;
748 }
749 EXPORT_SYMBOL_GPL(fwnode_get_next_parent);
750 
751 /**
752  * fwnode_count_parents - Return the number of parents a node has
753  * @fwnode: The node the parents of which are to be counted
754  *
755  * Return: the number of parents a node has.
756  */
757 unsigned int fwnode_count_parents(const struct fwnode_handle *fwnode)
758 {
759 	struct fwnode_handle *parent;
760 	unsigned int count = 0;
761 
762 	fwnode_for_each_parent_node(fwnode, parent)
763 		count++;
764 
765 	return count;
766 }
767 EXPORT_SYMBOL_GPL(fwnode_count_parents);
768 
769 /**
770  * fwnode_get_nth_parent - Return an nth parent of a node
771  * @fwnode: The node the parent of which is requested
772  * @depth: Distance of the parent from the node
773  *
774  * The caller is responsible for calling fwnode_handle_put() on the returned
775  * fwnode pointer.
776  *
777  * Return: the nth parent of a node. If there is no parent at the requested
778  * @depth, %NULL is returned. If @depth is 0, the functionality is equivalent to
779  * fwnode_handle_get(). For @depth == 1, it is fwnode_get_parent() and so on.
780  */
781 struct fwnode_handle *fwnode_get_nth_parent(struct fwnode_handle *fwnode,
782 					    unsigned int depth)
783 {
784 	struct fwnode_handle *parent;
785 
786 	if (depth == 0)
787 		return fwnode_handle_get(fwnode);
788 
789 	fwnode_for_each_parent_node(fwnode, parent) {
790 		if (--depth == 0)
791 			return parent;
792 	}
793 	return NULL;
794 }
795 EXPORT_SYMBOL_GPL(fwnode_get_nth_parent);
796 
797 /**
798  * fwnode_get_next_child_node - Return the next child node handle for a node
799  * @fwnode: Firmware node to find the next child node for.
800  * @child: Handle to one of the node's child nodes or a %NULL handle.
801  *
802  * The caller is responsible for calling fwnode_handle_put() on the returned
803  * fwnode pointer. Note that this function also puts a reference to @child
804  * unconditionally.
805  */
806 struct fwnode_handle *
807 fwnode_get_next_child_node(const struct fwnode_handle *fwnode,
808 			   struct fwnode_handle *child)
809 {
810 	struct fwnode_handle *next;
811 
812 	if (IS_ERR_OR_NULL(fwnode))
813 		return NULL;
814 
815 	/* Try to find a child in primary fwnode */
816 	next = fwnode_call_ptr_op(fwnode, get_next_child_node, child);
817 	if (next)
818 		return next;
819 
820 	/* When no more children in primary, continue with secondary */
821 	return fwnode_call_ptr_op(fwnode->secondary, get_next_child_node, child);
822 }
823 EXPORT_SYMBOL_GPL(fwnode_get_next_child_node);
824 
825 /**
826  * fwnode_get_next_available_child_node - Return the next available child node handle for a node
827  * @fwnode: Firmware node to find the next child node for.
828  * @child: Handle to one of the node's child nodes or a %NULL handle.
829  *
830  * The caller is responsible for calling fwnode_handle_put() on the returned
831  * fwnode pointer. Note that this function also puts a reference to @child
832  * unconditionally.
833  */
834 struct fwnode_handle *
835 fwnode_get_next_available_child_node(const struct fwnode_handle *fwnode,
836 				     struct fwnode_handle *child)
837 {
838 	struct fwnode_handle *next_child = child;
839 
840 	if (IS_ERR_OR_NULL(fwnode))
841 		return NULL;
842 
843 	do {
844 		next_child = fwnode_get_next_child_node(fwnode, next_child);
845 		if (!next_child)
846 			return NULL;
847 	} while (!fwnode_device_is_available(next_child));
848 
849 	return next_child;
850 }
851 EXPORT_SYMBOL_GPL(fwnode_get_next_available_child_node);
852 
853 /**
854  * device_get_next_child_node - Return the next child node handle for a device
855  * @dev: Device to find the next child node for.
856  * @child: Handle to one of the device's child nodes or a %NULL handle.
857  *
858  * The caller is responsible for calling fwnode_handle_put() on the returned
859  * fwnode pointer. Note that this function also puts a reference to @child
860  * unconditionally.
861  */
862 struct fwnode_handle *device_get_next_child_node(const struct device *dev,
863 						 struct fwnode_handle *child)
864 {
865 	return fwnode_get_next_child_node(dev_fwnode(dev), child);
866 }
867 EXPORT_SYMBOL_GPL(device_get_next_child_node);
868 
869 /**
870  * fwnode_get_named_child_node - Return first matching named child node handle
871  * @fwnode: Firmware node to find the named child node for.
872  * @childname: String to match child node name against.
873  *
874  * The caller is responsible for calling fwnode_handle_put() on the returned
875  * fwnode pointer.
876  */
877 struct fwnode_handle *
878 fwnode_get_named_child_node(const struct fwnode_handle *fwnode,
879 			    const char *childname)
880 {
881 	return fwnode_call_ptr_op(fwnode, get_named_child_node, childname);
882 }
883 EXPORT_SYMBOL_GPL(fwnode_get_named_child_node);
884 
885 /**
886  * device_get_named_child_node - Return first matching named child node handle
887  * @dev: Device to find the named child node for.
888  * @childname: String to match child node name against.
889  *
890  * The caller is responsible for calling fwnode_handle_put() on the returned
891  * fwnode pointer.
892  */
893 struct fwnode_handle *device_get_named_child_node(const struct device *dev,
894 						  const char *childname)
895 {
896 	return fwnode_get_named_child_node(dev_fwnode(dev), childname);
897 }
898 EXPORT_SYMBOL_GPL(device_get_named_child_node);
899 
900 /**
901  * fwnode_handle_get - Obtain a reference to a device node
902  * @fwnode: Pointer to the device node to obtain the reference to.
903  *
904  * The caller is responsible for calling fwnode_handle_put() on the returned
905  * fwnode pointer.
906  *
907  * Return: the fwnode handle.
908  */
909 struct fwnode_handle *fwnode_handle_get(struct fwnode_handle *fwnode)
910 {
911 	if (!fwnode_has_op(fwnode, get))
912 		return fwnode;
913 
914 	return fwnode_call_ptr_op(fwnode, get);
915 }
916 EXPORT_SYMBOL_GPL(fwnode_handle_get);
917 
918 /**
919  * fwnode_device_is_available - check if a device is available for use
920  * @fwnode: Pointer to the fwnode of the device.
921  *
922  * Return: true if device is available for use. Otherwise, returns false.
923  *
924  * For fwnode node types that don't implement the .device_is_available()
925  * operation, this function returns true.
926  */
927 bool fwnode_device_is_available(const struct fwnode_handle *fwnode)
928 {
929 	if (IS_ERR_OR_NULL(fwnode))
930 		return false;
931 
932 	if (!fwnode_has_op(fwnode, device_is_available))
933 		return true;
934 
935 	return fwnode_call_bool_op(fwnode, device_is_available);
936 }
937 EXPORT_SYMBOL_GPL(fwnode_device_is_available);
938 
939 /**
940  * fwnode_get_child_node_count - return the number of child nodes for a given firmware node
941  * @fwnode: Pointer to the parent firmware node
942  *
943  * Return: the number of child nodes for a given firmware node.
944  */
945 unsigned int fwnode_get_child_node_count(const struct fwnode_handle *fwnode)
946 {
947 	struct fwnode_handle *child;
948 	unsigned int count = 0;
949 
950 	fwnode_for_each_child_node(fwnode, child)
951 		count++;
952 
953 	return count;
954 }
955 EXPORT_SYMBOL_GPL(fwnode_get_child_node_count);
956 
957 /**
958  * fwnode_get_named_child_node_count - number of child nodes with given name
959  * @fwnode: Node which child nodes are counted.
960  * @name: String to match child node name against.
961  *
962  * Scan child nodes and count all the nodes with a specific name. Potential
963  * 'number' -ending after the 'at sign' for scanned names is ignored.
964  * E.g.::
965  *   fwnode_get_named_child_node_count(fwnode, "channel");
966  * would match all the nodes::
967  *   channel { }, channel@0 {}, channel@0xabba {}...
968  *
969  * Return: the number of child nodes with a matching name for a given device.
970  */
971 unsigned int fwnode_get_named_child_node_count(const struct fwnode_handle *fwnode,
972 					       const char *name)
973 {
974 	struct fwnode_handle *child;
975 	unsigned int count = 0;
976 
977 	fwnode_for_each_named_child_node(fwnode, child, name)
978 		count++;
979 
980 	return count;
981 }
982 EXPORT_SYMBOL_GPL(fwnode_get_named_child_node_count);
983 
984 bool device_dma_supported(const struct device *dev)
985 {
986 	return fwnode_call_bool_op(dev_fwnode(dev), device_dma_supported);
987 }
988 EXPORT_SYMBOL_GPL(device_dma_supported);
989 
990 enum dev_dma_attr device_get_dma_attr(const struct device *dev)
991 {
992 	if (!fwnode_has_op(dev_fwnode(dev), device_get_dma_attr))
993 		return DEV_DMA_NOT_SUPPORTED;
994 
995 	return fwnode_call_int_op(dev_fwnode(dev), device_get_dma_attr);
996 }
997 EXPORT_SYMBOL_GPL(device_get_dma_attr);
998 
999 /**
1000  * fwnode_get_phy_mode - Get phy mode for given firmware node
1001  * @fwnode:	Pointer to the given node
1002  *
1003  * The function gets phy interface string from property 'phy-mode' or
1004  * 'phy-connection-type', and return its index in phy_modes table, or errno in
1005  * error case.
1006  */
1007 int fwnode_get_phy_mode(const struct fwnode_handle *fwnode)
1008 {
1009 	const char *pm;
1010 	int err, i;
1011 
1012 	err = fwnode_property_read_string(fwnode, "phy-mode", &pm);
1013 	if (err < 0)
1014 		err = fwnode_property_read_string(fwnode,
1015 						  "phy-connection-type", &pm);
1016 	if (err < 0)
1017 		return err;
1018 
1019 	for (i = 0; i < PHY_INTERFACE_MODE_MAX; i++)
1020 		if (!strcasecmp(pm, phy_modes(i)))
1021 			return i;
1022 
1023 	return -ENODEV;
1024 }
1025 EXPORT_SYMBOL_GPL(fwnode_get_phy_mode);
1026 
1027 /**
1028  * device_get_phy_mode - Get phy mode for given device
1029  * @dev:	Pointer to the given device
1030  *
1031  * The function gets phy interface string from property 'phy-mode' or
1032  * 'phy-connection-type', and return its index in phy_modes table, or errno in
1033  * error case.
1034  */
1035 int device_get_phy_mode(struct device *dev)
1036 {
1037 	return fwnode_get_phy_mode(dev_fwnode(dev));
1038 }
1039 EXPORT_SYMBOL_GPL(device_get_phy_mode);
1040 
1041 /**
1042  * fwnode_iomap - Maps the memory mapped IO for a given fwnode
1043  * @fwnode:	Pointer to the firmware node
1044  * @index:	Index of the IO range
1045  *
1046  * Return: a pointer to the mapped memory.
1047  */
1048 void __iomem *fwnode_iomap(struct fwnode_handle *fwnode, int index)
1049 {
1050 	return fwnode_call_ptr_op(fwnode, iomap, index);
1051 }
1052 EXPORT_SYMBOL(fwnode_iomap);
1053 
1054 /**
1055  * fwnode_irq_get - Get IRQ directly from a fwnode
1056  * @fwnode:	Pointer to the firmware node
1057  * @index:	Zero-based index of the IRQ
1058  *
1059  * Return: Linux IRQ number on success. Negative errno on failure.
1060  */
1061 int fwnode_irq_get(const struct fwnode_handle *fwnode, unsigned int index)
1062 {
1063 	int ret;
1064 
1065 	ret = fwnode_call_int_op(fwnode, irq_get, index);
1066 	/* We treat mapping errors as invalid case */
1067 	if (ret == 0)
1068 		return -EINVAL;
1069 
1070 	return ret;
1071 }
1072 EXPORT_SYMBOL(fwnode_irq_get);
1073 
1074 /**
1075  * fwnode_irq_get_byname - Get IRQ from a fwnode using its name
1076  * @fwnode:	Pointer to the firmware node
1077  * @name:	IRQ name
1078  *
1079  * Description:
1080  * Find a match to the string @name in the 'interrupt-names' string array
1081  * in _DSD for ACPI, or of_node for Device Tree. Then get the Linux IRQ
1082  * number of the IRQ resource corresponding to the index of the matched
1083  * string.
1084  *
1085  * Return: Linux IRQ number on success, or negative errno otherwise.
1086  */
1087 int fwnode_irq_get_byname(const struct fwnode_handle *fwnode, const char *name)
1088 {
1089 	int index;
1090 
1091 	if (!name)
1092 		return -EINVAL;
1093 
1094 	index = fwnode_property_match_string(fwnode, "interrupt-names",  name);
1095 	if (index < 0)
1096 		return index;
1097 
1098 	return fwnode_irq_get(fwnode, index);
1099 }
1100 EXPORT_SYMBOL(fwnode_irq_get_byname);
1101 
1102 /**
1103  * fwnode_graph_get_next_endpoint - Get next endpoint firmware node
1104  * @fwnode: Pointer to the parent firmware node
1105  * @prev: Previous endpoint node or %NULL to get the first
1106  *
1107  * The caller is responsible for calling fwnode_handle_put() on the returned
1108  * fwnode pointer. Note that this function also puts a reference to @prev
1109  * unconditionally.
1110  *
1111  * Return: an endpoint firmware node pointer or %NULL if no more endpoints
1112  * are available.
1113  */
1114 struct fwnode_handle *
1115 fwnode_graph_get_next_endpoint(const struct fwnode_handle *fwnode,
1116 			       struct fwnode_handle *prev)
1117 {
1118 	struct fwnode_handle *ep, *port_parent = NULL;
1119 	const struct fwnode_handle *parent;
1120 
1121 	/*
1122 	 * If this function is in a loop and the previous iteration returned
1123 	 * an endpoint from fwnode->secondary, then we need to use the secondary
1124 	 * as parent rather than @fwnode.
1125 	 */
1126 	if (prev) {
1127 		port_parent = fwnode_graph_get_port_parent(prev);
1128 		parent = port_parent;
1129 	} else {
1130 		parent = fwnode;
1131 	}
1132 	if (IS_ERR_OR_NULL(parent))
1133 		return NULL;
1134 
1135 	ep = fwnode_call_ptr_op(parent, graph_get_next_endpoint, prev);
1136 	if (ep)
1137 		goto out_put_port_parent;
1138 
1139 	ep = fwnode_graph_get_next_endpoint(parent->secondary, NULL);
1140 
1141 out_put_port_parent:
1142 	fwnode_handle_put(port_parent);
1143 	return ep;
1144 }
1145 EXPORT_SYMBOL_GPL(fwnode_graph_get_next_endpoint);
1146 
1147 /**
1148  * fwnode_graph_get_port_parent - Return the device fwnode of a port endpoint
1149  * @endpoint: Endpoint firmware node of the port
1150  *
1151  * The caller is responsible for calling fwnode_handle_put() on the returned
1152  * fwnode pointer.
1153  *
1154  * Return: the firmware node of the device the @endpoint belongs to.
1155  */
1156 struct fwnode_handle *
1157 fwnode_graph_get_port_parent(const struct fwnode_handle *endpoint)
1158 {
1159 	struct fwnode_handle *port, *parent;
1160 
1161 	port = fwnode_get_parent(endpoint);
1162 	parent = fwnode_call_ptr_op(port, graph_get_port_parent);
1163 
1164 	fwnode_handle_put(port);
1165 
1166 	return parent;
1167 }
1168 EXPORT_SYMBOL_GPL(fwnode_graph_get_port_parent);
1169 
1170 /**
1171  * fwnode_graph_get_remote_port_parent - Return fwnode of a remote device
1172  * @fwnode: Endpoint firmware node pointing to the remote endpoint
1173  *
1174  * Extracts firmware node of a remote device the @fwnode points to.
1175  *
1176  * The caller is responsible for calling fwnode_handle_put() on the returned
1177  * fwnode pointer.
1178  */
1179 struct fwnode_handle *
1180 fwnode_graph_get_remote_port_parent(const struct fwnode_handle *fwnode)
1181 {
1182 	struct fwnode_handle *endpoint, *parent;
1183 
1184 	endpoint = fwnode_graph_get_remote_endpoint(fwnode);
1185 	parent = fwnode_graph_get_port_parent(endpoint);
1186 
1187 	fwnode_handle_put(endpoint);
1188 
1189 	return parent;
1190 }
1191 EXPORT_SYMBOL_GPL(fwnode_graph_get_remote_port_parent);
1192 
1193 /**
1194  * fwnode_graph_get_remote_port - Return fwnode of a remote port
1195  * @fwnode: Endpoint firmware node pointing to the remote endpoint
1196  *
1197  * Extracts firmware node of a remote port the @fwnode points to.
1198  *
1199  * The caller is responsible for calling fwnode_handle_put() on the returned
1200  * fwnode pointer.
1201  */
1202 struct fwnode_handle *
1203 fwnode_graph_get_remote_port(const struct fwnode_handle *fwnode)
1204 {
1205 	return fwnode_get_next_parent(fwnode_graph_get_remote_endpoint(fwnode));
1206 }
1207 EXPORT_SYMBOL_GPL(fwnode_graph_get_remote_port);
1208 
1209 /**
1210  * fwnode_graph_get_remote_endpoint - Return fwnode of a remote endpoint
1211  * @fwnode: Endpoint firmware node pointing to the remote endpoint
1212  *
1213  * Extracts firmware node of a remote endpoint the @fwnode points to.
1214  *
1215  * The caller is responsible for calling fwnode_handle_put() on the returned
1216  * fwnode pointer.
1217  */
1218 struct fwnode_handle *
1219 fwnode_graph_get_remote_endpoint(const struct fwnode_handle *fwnode)
1220 {
1221 	return fwnode_call_ptr_op(fwnode, graph_get_remote_endpoint);
1222 }
1223 EXPORT_SYMBOL_GPL(fwnode_graph_get_remote_endpoint);
1224 
1225 static bool fwnode_graph_remote_available(struct fwnode_handle *ep)
1226 {
1227 	struct fwnode_handle *dev_node;
1228 	bool available;
1229 
1230 	dev_node = fwnode_graph_get_remote_port_parent(ep);
1231 	available = fwnode_device_is_available(dev_node);
1232 	fwnode_handle_put(dev_node);
1233 
1234 	return available;
1235 }
1236 
1237 /**
1238  * fwnode_graph_get_endpoint_by_id - get endpoint by port and endpoint numbers
1239  * @fwnode: parent fwnode_handle containing the graph
1240  * @port: identifier of the port node
1241  * @endpoint: identifier of the endpoint node under the port node
1242  * @flags: fwnode lookup flags
1243  *
1244  * The caller is responsible for calling fwnode_handle_put() on the returned
1245  * fwnode pointer.
1246  *
1247  * Return: the fwnode handle of the local endpoint corresponding the port and
1248  * endpoint IDs or %NULL if not found.
1249  *
1250  * If FWNODE_GRAPH_ENDPOINT_NEXT is passed in @flags and the specified endpoint
1251  * has not been found, look for the closest endpoint ID greater than the
1252  * specified one and return the endpoint that corresponds to it, if present.
1253  *
1254  * Does not return endpoints that belong to disabled devices or endpoints that
1255  * are unconnected, unless FWNODE_GRAPH_DEVICE_DISABLED is passed in @flags.
1256  */
1257 struct fwnode_handle *
1258 fwnode_graph_get_endpoint_by_id(const struct fwnode_handle *fwnode,
1259 				u32 port, u32 endpoint, unsigned long flags)
1260 {
1261 	struct fwnode_handle *ep, *best_ep = NULL;
1262 	unsigned int best_ep_id = 0;
1263 	bool endpoint_next = flags & FWNODE_GRAPH_ENDPOINT_NEXT;
1264 	bool enabled_only = !(flags & FWNODE_GRAPH_DEVICE_DISABLED);
1265 
1266 	fwnode_graph_for_each_endpoint(fwnode, ep) {
1267 		struct fwnode_endpoint fwnode_ep = { 0 };
1268 		int ret;
1269 
1270 		if (enabled_only && !fwnode_graph_remote_available(ep))
1271 			continue;
1272 
1273 		ret = fwnode_graph_parse_endpoint(ep, &fwnode_ep);
1274 		if (ret < 0)
1275 			continue;
1276 
1277 		if (fwnode_ep.port != port)
1278 			continue;
1279 
1280 		if (fwnode_ep.id == endpoint)
1281 			return ep;
1282 
1283 		if (!endpoint_next)
1284 			continue;
1285 
1286 		/*
1287 		 * If the endpoint that has just been found is not the first
1288 		 * matching one and the ID of the one found previously is closer
1289 		 * to the requested endpoint ID, skip it.
1290 		 */
1291 		if (fwnode_ep.id < endpoint ||
1292 		    (best_ep && best_ep_id < fwnode_ep.id))
1293 			continue;
1294 
1295 		fwnode_handle_put(best_ep);
1296 		best_ep = fwnode_handle_get(ep);
1297 		best_ep_id = fwnode_ep.id;
1298 	}
1299 
1300 	return best_ep;
1301 }
1302 EXPORT_SYMBOL_GPL(fwnode_graph_get_endpoint_by_id);
1303 
1304 /**
1305  * fwnode_graph_get_endpoint_count - Count endpoints on a device node
1306  * @fwnode: The node related to a device
1307  * @flags: fwnode lookup flags
1308  * Count endpoints in a device node.
1309  *
1310  * If FWNODE_GRAPH_DEVICE_DISABLED flag is specified, also unconnected endpoints
1311  * and endpoints connected to disabled devices are counted.
1312  */
1313 unsigned int fwnode_graph_get_endpoint_count(const struct fwnode_handle *fwnode,
1314 					     unsigned long flags)
1315 {
1316 	struct fwnode_handle *ep;
1317 	unsigned int count = 0;
1318 
1319 	fwnode_graph_for_each_endpoint(fwnode, ep) {
1320 		if (flags & FWNODE_GRAPH_DEVICE_DISABLED ||
1321 		    fwnode_graph_remote_available(ep))
1322 			count++;
1323 	}
1324 
1325 	return count;
1326 }
1327 EXPORT_SYMBOL_GPL(fwnode_graph_get_endpoint_count);
1328 
1329 /**
1330  * fwnode_graph_parse_endpoint - parse common endpoint node properties
1331  * @fwnode: pointer to endpoint fwnode_handle
1332  * @endpoint: pointer to the fwnode endpoint data structure
1333  *
1334  * Parse @fwnode representing a graph endpoint node and store the
1335  * information in @endpoint. The caller must hold a reference to
1336  * @fwnode.
1337  */
1338 int fwnode_graph_parse_endpoint(const struct fwnode_handle *fwnode,
1339 				struct fwnode_endpoint *endpoint)
1340 {
1341 	memset(endpoint, 0, sizeof(*endpoint));
1342 
1343 	return fwnode_call_int_op(fwnode, graph_parse_endpoint, endpoint);
1344 }
1345 EXPORT_SYMBOL(fwnode_graph_parse_endpoint);
1346 
1347 const void *device_get_match_data(const struct device *dev)
1348 {
1349 	return fwnode_call_ptr_op(dev_fwnode(dev), device_get_match_data, dev);
1350 }
1351 EXPORT_SYMBOL_GPL(device_get_match_data);
1352 
1353 static unsigned int fwnode_graph_devcon_matches(const struct fwnode_handle *fwnode,
1354 						const char *con_id, void *data,
1355 						devcon_match_fn_t match,
1356 						void **matches,
1357 						unsigned int matches_len)
1358 {
1359 	struct fwnode_handle *node;
1360 	struct fwnode_handle *ep;
1361 	unsigned int count = 0;
1362 	void *ret;
1363 
1364 	fwnode_graph_for_each_endpoint(fwnode, ep) {
1365 		if (matches && count >= matches_len) {
1366 			fwnode_handle_put(ep);
1367 			break;
1368 		}
1369 
1370 		node = fwnode_graph_get_remote_port_parent(ep);
1371 		if (!fwnode_device_is_available(node)) {
1372 			fwnode_handle_put(node);
1373 			continue;
1374 		}
1375 
1376 		ret = match(node, con_id, data);
1377 		fwnode_handle_put(node);
1378 		if (ret) {
1379 			if (matches)
1380 				matches[count] = ret;
1381 			count++;
1382 		}
1383 	}
1384 	return count;
1385 }
1386 
1387 static unsigned int fwnode_devcon_matches(const struct fwnode_handle *fwnode,
1388 					  const char *con_id, void *data,
1389 					  devcon_match_fn_t match,
1390 					  void **matches,
1391 					  unsigned int matches_len)
1392 {
1393 	struct fwnode_handle *node;
1394 	unsigned int count = 0;
1395 	unsigned int i;
1396 	void *ret;
1397 
1398 	for (i = 0; ; i++) {
1399 		if (matches && count >= matches_len)
1400 			break;
1401 
1402 		node = fwnode_find_reference(fwnode, con_id, i);
1403 		if (IS_ERR(node))
1404 			break;
1405 
1406 		ret = match(node, NULL, data);
1407 		fwnode_handle_put(node);
1408 		if (ret) {
1409 			if (matches)
1410 				matches[count] = ret;
1411 			count++;
1412 		}
1413 	}
1414 
1415 	return count;
1416 }
1417 
1418 /**
1419  * fwnode_connection_find_match - Find connection from a device node
1420  * @fwnode: Device node with the connection
1421  * @con_id: Identifier for the connection
1422  * @data: Data for the match function
1423  * @match: Function to check and convert the connection description
1424  *
1425  * Find a connection with unique identifier @con_id between @fwnode and another
1426  * device node. @match will be used to convert the connection description to
1427  * data the caller is expecting to be returned.
1428  */
1429 void *fwnode_connection_find_match(const struct fwnode_handle *fwnode,
1430 				   const char *con_id, void *data,
1431 				   devcon_match_fn_t match)
1432 {
1433 	unsigned int count;
1434 	void *ret;
1435 
1436 	if (!fwnode || !match)
1437 		return NULL;
1438 
1439 	count = fwnode_graph_devcon_matches(fwnode, con_id, data, match, &ret, 1);
1440 	if (count)
1441 		return ret;
1442 
1443 	count = fwnode_devcon_matches(fwnode, con_id, data, match, &ret, 1);
1444 	return count ? ret : NULL;
1445 }
1446 EXPORT_SYMBOL_GPL(fwnode_connection_find_match);
1447 
1448 /**
1449  * fwnode_connection_find_matches - Find connections from a device node
1450  * @fwnode: Device node with the connection
1451  * @con_id: Identifier for the connection
1452  * @data: Data for the match function
1453  * @match: Function to check and convert the connection description
1454  * @matches: (Optional) array of pointers to fill with matches
1455  * @matches_len: Length of @matches
1456  *
1457  * Find up to @matches_len connections with unique identifier @con_id between
1458  * @fwnode and other device nodes. @match will be used to convert the
1459  * connection description to data the caller is expecting to be returned
1460  * through the @matches array.
1461  *
1462  * If @matches is %NULL @matches_len is ignored and the total number of resolved
1463  * matches is returned.
1464  *
1465  * Return: Number of matches resolved, or negative errno.
1466  */
1467 int fwnode_connection_find_matches(const struct fwnode_handle *fwnode,
1468 				   const char *con_id, void *data,
1469 				   devcon_match_fn_t match,
1470 				   void **matches, unsigned int matches_len)
1471 {
1472 	unsigned int count_graph;
1473 	unsigned int count_ref;
1474 
1475 	if (!fwnode || !match)
1476 		return -EINVAL;
1477 
1478 	count_graph = fwnode_graph_devcon_matches(fwnode, con_id, data, match,
1479 						  matches, matches_len);
1480 
1481 	if (matches) {
1482 		matches += count_graph;
1483 		matches_len -= count_graph;
1484 	}
1485 
1486 	count_ref = fwnode_devcon_matches(fwnode, con_id, data, match,
1487 					  matches, matches_len);
1488 
1489 	return count_graph + count_ref;
1490 }
1491 EXPORT_SYMBOL_GPL(fwnode_connection_find_matches);
1492