xref: /openbmc/linux/drivers/base/property.c (revision 08720988)
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/acpi.h>
11 #include <linux/export.h>
12 #include <linux/kernel.h>
13 #include <linux/of.h>
14 #include <linux/of_address.h>
15 #include <linux/of_graph.h>
16 #include <linux/of_irq.h>
17 #include <linux/property.h>
18 #include <linux/etherdevice.h>
19 #include <linux/phy.h>
20 
21 struct fwnode_handle *dev_fwnode(struct device *dev)
22 {
23 	return IS_ENABLED(CONFIG_OF) && dev->of_node ?
24 		&dev->of_node->fwnode : dev->fwnode;
25 }
26 EXPORT_SYMBOL_GPL(dev_fwnode);
27 
28 /**
29  * device_property_present - check if a property of a device is present
30  * @dev: Device whose property is being checked
31  * @propname: Name of the property
32  *
33  * Check if property @propname is present in the device firmware description.
34  */
35 bool device_property_present(struct device *dev, const char *propname)
36 {
37 	return fwnode_property_present(dev_fwnode(dev), propname);
38 }
39 EXPORT_SYMBOL_GPL(device_property_present);
40 
41 /**
42  * fwnode_property_present - check if a property of a firmware node is present
43  * @fwnode: Firmware node whose property to check
44  * @propname: Name of the property
45  */
46 bool fwnode_property_present(const struct fwnode_handle *fwnode,
47 			     const char *propname)
48 {
49 	bool ret;
50 
51 	ret = fwnode_call_bool_op(fwnode, property_present, propname);
52 	if (ret == false && !IS_ERR_OR_NULL(fwnode) &&
53 	    !IS_ERR_OR_NULL(fwnode->secondary))
54 		ret = fwnode_call_bool_op(fwnode->secondary, property_present,
55 					 propname);
56 	return ret;
57 }
58 EXPORT_SYMBOL_GPL(fwnode_property_present);
59 
60 /**
61  * device_property_read_u8_array - return a u8 array property of a device
62  * @dev: Device to get the property of
63  * @propname: Name of the property
64  * @val: The values are stored here or %NULL to return the number of values
65  * @nval: Size of the @val array
66  *
67  * Function reads an array of u8 properties with @propname from the device
68  * firmware description and stores them to @val if found.
69  *
70  * Return: number of values if @val was %NULL,
71  *         %0 if the property was found (success),
72  *	   %-EINVAL if given arguments are not valid,
73  *	   %-ENODATA if the property does not have a value,
74  *	   %-EPROTO if the property is not an array of numbers,
75  *	   %-EOVERFLOW if the size of the property is not as expected.
76  *	   %-ENXIO if no suitable firmware interface is present.
77  */
78 int device_property_read_u8_array(struct device *dev, const char *propname,
79 				  u8 *val, size_t nval)
80 {
81 	return fwnode_property_read_u8_array(dev_fwnode(dev), propname, val, nval);
82 }
83 EXPORT_SYMBOL_GPL(device_property_read_u8_array);
84 
85 /**
86  * device_property_read_u16_array - return a u16 array property of a device
87  * @dev: Device to get the property of
88  * @propname: Name of the property
89  * @val: The values are stored here or %NULL to return the number of values
90  * @nval: Size of the @val array
91  *
92  * Function reads an array of u16 properties with @propname from the device
93  * firmware description and stores them to @val if found.
94  *
95  * Return: number of values if @val was %NULL,
96  *         %0 if the property was found (success),
97  *	   %-EINVAL if given arguments are not valid,
98  *	   %-ENODATA if the property does not have a value,
99  *	   %-EPROTO if the property is not an array of numbers,
100  *	   %-EOVERFLOW if the size of the property is not as expected.
101  *	   %-ENXIO if no suitable firmware interface is present.
102  */
103 int device_property_read_u16_array(struct device *dev, const char *propname,
104 				   u16 *val, size_t nval)
105 {
106 	return fwnode_property_read_u16_array(dev_fwnode(dev), propname, val, nval);
107 }
108 EXPORT_SYMBOL_GPL(device_property_read_u16_array);
109 
110 /**
111  * device_property_read_u32_array - return a u32 array property of a device
112  * @dev: Device to get the property of
113  * @propname: Name of the property
114  * @val: The values are stored here or %NULL to return the number of values
115  * @nval: Size of the @val array
116  *
117  * Function reads an array of u32 properties with @propname from the device
118  * firmware description and stores them to @val if found.
119  *
120  * Return: number of values if @val was %NULL,
121  *         %0 if the property was found (success),
122  *	   %-EINVAL if given arguments are not valid,
123  *	   %-ENODATA if the property does not have a value,
124  *	   %-EPROTO if the property is not an array of numbers,
125  *	   %-EOVERFLOW if the size of the property is not as expected.
126  *	   %-ENXIO if no suitable firmware interface is present.
127  */
128 int device_property_read_u32_array(struct device *dev, const char *propname,
129 				   u32 *val, size_t nval)
130 {
131 	return fwnode_property_read_u32_array(dev_fwnode(dev), propname, val, nval);
132 }
133 EXPORT_SYMBOL_GPL(device_property_read_u32_array);
134 
135 /**
136  * device_property_read_u64_array - return a u64 array property of a device
137  * @dev: Device to get the property of
138  * @propname: Name of the property
139  * @val: The values are stored here or %NULL to return the number of values
140  * @nval: Size of the @val array
141  *
142  * Function reads an array of u64 properties with @propname from the device
143  * firmware description and stores them to @val if found.
144  *
145  * Return: number of values if @val was %NULL,
146  *         %0 if the property was found (success),
147  *	   %-EINVAL if given arguments are not valid,
148  *	   %-ENODATA if the property does not have a value,
149  *	   %-EPROTO if the property is not an array of numbers,
150  *	   %-EOVERFLOW if the size of the property is not as expected.
151  *	   %-ENXIO if no suitable firmware interface is present.
152  */
153 int device_property_read_u64_array(struct device *dev, const char *propname,
154 				   u64 *val, size_t nval)
155 {
156 	return fwnode_property_read_u64_array(dev_fwnode(dev), propname, val, nval);
157 }
158 EXPORT_SYMBOL_GPL(device_property_read_u64_array);
159 
160 /**
161  * device_property_read_string_array - return a string array property of device
162  * @dev: Device to get the property of
163  * @propname: Name of the property
164  * @val: The values are stored here or %NULL to return the number of values
165  * @nval: Size of the @val array
166  *
167  * Function reads an array of string properties with @propname from the device
168  * firmware description and stores them to @val if found.
169  *
170  * Return: number of values read on success if @val is non-NULL,
171  *	   number of values available on success if @val is NULL,
172  *	   %-EINVAL if given arguments are not valid,
173  *	   %-ENODATA if the property does not have a value,
174  *	   %-EPROTO or %-EILSEQ if the property is not an array of strings,
175  *	   %-EOVERFLOW if the size of the property is not as expected.
176  *	   %-ENXIO if no suitable firmware interface is present.
177  */
178 int device_property_read_string_array(struct device *dev, const char *propname,
179 				      const char **val, size_t nval)
180 {
181 	return fwnode_property_read_string_array(dev_fwnode(dev), propname, val, nval);
182 }
183 EXPORT_SYMBOL_GPL(device_property_read_string_array);
184 
185 /**
186  * device_property_read_string - return a string property of a device
187  * @dev: Device to get the property of
188  * @propname: Name of the property
189  * @val: The value is stored here
190  *
191  * Function reads property @propname from the device firmware description and
192  * stores the value into @val if found. The value is checked to be a string.
193  *
194  * Return: %0 if the property was found (success),
195  *	   %-EINVAL if given arguments are not valid,
196  *	   %-ENODATA if the property does not have a value,
197  *	   %-EPROTO or %-EILSEQ if the property type is not a string.
198  *	   %-ENXIO if no suitable firmware interface is present.
199  */
200 int device_property_read_string(struct device *dev, const char *propname,
201 				const char **val)
202 {
203 	return fwnode_property_read_string(dev_fwnode(dev), propname, val);
204 }
205 EXPORT_SYMBOL_GPL(device_property_read_string);
206 
207 /**
208  * device_property_match_string - find a string in an array and return index
209  * @dev: Device to get the property of
210  * @propname: Name of the property holding the array
211  * @string: String to look for
212  *
213  * Find a given string in a string array and if it is found return the
214  * index back.
215  *
216  * Return: %0 if the property was found (success),
217  *	   %-EINVAL if given arguments are not valid,
218  *	   %-ENODATA if the property does not have a value,
219  *	   %-EPROTO if the property is not an array of strings,
220  *	   %-ENXIO if no suitable firmware interface is present.
221  */
222 int device_property_match_string(struct device *dev, const char *propname,
223 				 const char *string)
224 {
225 	return fwnode_property_match_string(dev_fwnode(dev), propname, string);
226 }
227 EXPORT_SYMBOL_GPL(device_property_match_string);
228 
229 static int fwnode_property_read_int_array(const struct fwnode_handle *fwnode,
230 					  const char *propname,
231 					  unsigned int elem_size, void *val,
232 					  size_t nval)
233 {
234 	int ret;
235 
236 	ret = fwnode_call_int_op(fwnode, property_read_int_array, propname,
237 				 elem_size, val, nval);
238 	if (ret == -EINVAL && !IS_ERR_OR_NULL(fwnode) &&
239 	    !IS_ERR_OR_NULL(fwnode->secondary))
240 		ret = fwnode_call_int_op(
241 			fwnode->secondary, property_read_int_array, propname,
242 			elem_size, val, nval);
243 
244 	return ret;
245 }
246 
247 /**
248  * fwnode_property_read_u8_array - return a u8 array property of firmware node
249  * @fwnode: Firmware node to get the property of
250  * @propname: Name of the property
251  * @val: The values are stored here or %NULL to return the number of values
252  * @nval: Size of the @val array
253  *
254  * Read an array of u8 properties with @propname from @fwnode and stores them to
255  * @val if found.
256  *
257  * Return: number of values if @val was %NULL,
258  *         %0 if the property was found (success),
259  *	   %-EINVAL if given arguments are not valid,
260  *	   %-ENODATA if the property does not have a value,
261  *	   %-EPROTO if the property is not an array of numbers,
262  *	   %-EOVERFLOW if the size of the property is not as expected,
263  *	   %-ENXIO if no suitable firmware interface is present.
264  */
265 int fwnode_property_read_u8_array(const struct fwnode_handle *fwnode,
266 				  const char *propname, u8 *val, size_t nval)
267 {
268 	return fwnode_property_read_int_array(fwnode, propname, sizeof(u8),
269 					      val, nval);
270 }
271 EXPORT_SYMBOL_GPL(fwnode_property_read_u8_array);
272 
273 /**
274  * fwnode_property_read_u16_array - return a u16 array property of firmware node
275  * @fwnode: Firmware node to get the property of
276  * @propname: Name of the property
277  * @val: The values are stored here or %NULL to return the number of values
278  * @nval: Size of the @val array
279  *
280  * Read an array of u16 properties with @propname from @fwnode and store them to
281  * @val if found.
282  *
283  * Return: number of values if @val was %NULL,
284  *         %0 if the property was found (success),
285  *	   %-EINVAL if given arguments are not valid,
286  *	   %-ENODATA if the property does not have a value,
287  *	   %-EPROTO if the property is not an array of numbers,
288  *	   %-EOVERFLOW if the size of the property is not as expected,
289  *	   %-ENXIO if no suitable firmware interface is present.
290  */
291 int fwnode_property_read_u16_array(const struct fwnode_handle *fwnode,
292 				   const char *propname, u16 *val, size_t nval)
293 {
294 	return fwnode_property_read_int_array(fwnode, propname, sizeof(u16),
295 					      val, nval);
296 }
297 EXPORT_SYMBOL_GPL(fwnode_property_read_u16_array);
298 
299 /**
300  * fwnode_property_read_u32_array - return a u32 array property of firmware node
301  * @fwnode: Firmware node to get the property of
302  * @propname: Name of the property
303  * @val: The values are stored here or %NULL to return the number of values
304  * @nval: Size of the @val array
305  *
306  * Read an array of u32 properties with @propname from @fwnode store them to
307  * @val if found.
308  *
309  * Return: number of values if @val was %NULL,
310  *         %0 if the property was found (success),
311  *	   %-EINVAL if given arguments are not valid,
312  *	   %-ENODATA if the property does not have a value,
313  *	   %-EPROTO if the property is not an array of numbers,
314  *	   %-EOVERFLOW if the size of the property is not as expected,
315  *	   %-ENXIO if no suitable firmware interface is present.
316  */
317 int fwnode_property_read_u32_array(const struct fwnode_handle *fwnode,
318 				   const char *propname, u32 *val, size_t nval)
319 {
320 	return fwnode_property_read_int_array(fwnode, propname, sizeof(u32),
321 					      val, nval);
322 }
323 EXPORT_SYMBOL_GPL(fwnode_property_read_u32_array);
324 
325 /**
326  * fwnode_property_read_u64_array - return a u64 array property firmware node
327  * @fwnode: Firmware node to get the property of
328  * @propname: Name of the property
329  * @val: The values are stored here or %NULL to return the number of values
330  * @nval: Size of the @val array
331  *
332  * Read an array of u64 properties with @propname from @fwnode and store them to
333  * @val if found.
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_u64_array(const struct fwnode_handle *fwnode,
344 				   const char *propname, u64 *val, size_t nval)
345 {
346 	return fwnode_property_read_int_array(fwnode, propname, sizeof(u64),
347 					      val, nval);
348 }
349 EXPORT_SYMBOL_GPL(fwnode_property_read_u64_array);
350 
351 /**
352  * fwnode_property_read_string_array - return string array property of a 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 string list property @propname from the given firmware node and store
359  * them to @val if found.
360  *
361  * Return: number of values read on success if @val is non-NULL,
362  *	   number of values available on success if @val is NULL,
363  *	   %-EINVAL if given arguments are not valid,
364  *	   %-ENODATA if the property does not have a value,
365  *	   %-EPROTO or %-EILSEQ if the property is not an array of strings,
366  *	   %-EOVERFLOW if the size of the property is not as expected,
367  *	   %-ENXIO if no suitable firmware interface is present.
368  */
369 int fwnode_property_read_string_array(const struct fwnode_handle *fwnode,
370 				      const char *propname, const char **val,
371 				      size_t nval)
372 {
373 	int ret;
374 
375 	ret = fwnode_call_int_op(fwnode, property_read_string_array, propname,
376 				 val, nval);
377 	if (ret == -EINVAL && !IS_ERR_OR_NULL(fwnode) &&
378 	    !IS_ERR_OR_NULL(fwnode->secondary))
379 		ret = fwnode_call_int_op(fwnode->secondary,
380 					 property_read_string_array, propname,
381 					 val, nval);
382 	return ret;
383 }
384 EXPORT_SYMBOL_GPL(fwnode_property_read_string_array);
385 
386 /**
387  * fwnode_property_read_string - return a string property of a firmware node
388  * @fwnode: Firmware node to get the property of
389  * @propname: Name of the property
390  * @val: The value is stored here
391  *
392  * Read property @propname from the given firmware node and store the value into
393  * @val if found.  The value is checked to be a string.
394  *
395  * Return: %0 if the property was found (success),
396  *	   %-EINVAL if given arguments are not valid,
397  *	   %-ENODATA if the property does not have a value,
398  *	   %-EPROTO or %-EILSEQ if the property is not a string,
399  *	   %-ENXIO if no suitable firmware interface is present.
400  */
401 int fwnode_property_read_string(const struct fwnode_handle *fwnode,
402 				const char *propname, const char **val)
403 {
404 	int ret = fwnode_property_read_string_array(fwnode, propname, val, 1);
405 
406 	return ret < 0 ? ret : 0;
407 }
408 EXPORT_SYMBOL_GPL(fwnode_property_read_string);
409 
410 /**
411  * fwnode_property_match_string - find a string in an array and return index
412  * @fwnode: Firmware node to get the property of
413  * @propname: Name of the property holding the array
414  * @string: String to look for
415  *
416  * Find a given string in a string array and if it is found return the
417  * index back.
418  *
419  * Return: %0 if the property was found (success),
420  *	   %-EINVAL if given arguments are not valid,
421  *	   %-ENODATA if the property does not have a value,
422  *	   %-EPROTO if the property is not an array of strings,
423  *	   %-ENXIO if no suitable firmware interface is present.
424  */
425 int fwnode_property_match_string(const struct fwnode_handle *fwnode,
426 	const char *propname, const char *string)
427 {
428 	const char **values;
429 	int nval, ret;
430 
431 	nval = fwnode_property_read_string_array(fwnode, propname, NULL, 0);
432 	if (nval < 0)
433 		return nval;
434 
435 	if (nval == 0)
436 		return -ENODATA;
437 
438 	values = kcalloc(nval, sizeof(*values), GFP_KERNEL);
439 	if (!values)
440 		return -ENOMEM;
441 
442 	ret = fwnode_property_read_string_array(fwnode, propname, values, nval);
443 	if (ret < 0)
444 		goto out;
445 
446 	ret = match_string(values, nval, string);
447 	if (ret < 0)
448 		ret = -ENODATA;
449 out:
450 	kfree(values);
451 	return ret;
452 }
453 EXPORT_SYMBOL_GPL(fwnode_property_match_string);
454 
455 /**
456  * fwnode_property_get_reference_args() - Find a reference with arguments
457  * @fwnode:	Firmware node where to look for the reference
458  * @prop:	The name of the property
459  * @nargs_prop:	The name of the property telling the number of
460  *		arguments in the referred node. NULL if @nargs is known,
461  *		otherwise @nargs is ignored. Only relevant on OF.
462  * @nargs:	Number of arguments. Ignored if @nargs_prop is non-NULL.
463  * @index:	Index of the reference, from zero onwards.
464  * @args:	Result structure with reference and integer arguments.
465  *
466  * Obtain a reference based on a named property in an fwnode, with
467  * integer arguments.
468  *
469  * Caller is responsible to call fwnode_handle_put() on the returned
470  * args->fwnode pointer.
471  *
472  * Returns: %0 on success
473  *	    %-ENOENT when the index is out of bounds, the index has an empty
474  *		     reference or the property was not found
475  *	    %-EINVAL on parse error
476  */
477 int fwnode_property_get_reference_args(const struct fwnode_handle *fwnode,
478 				       const char *prop, const char *nargs_prop,
479 				       unsigned int nargs, unsigned int index,
480 				       struct fwnode_reference_args *args)
481 {
482 	return fwnode_call_int_op(fwnode, get_reference_args, prop, nargs_prop,
483 				  nargs, index, args);
484 }
485 EXPORT_SYMBOL_GPL(fwnode_property_get_reference_args);
486 
487 /**
488  * fwnode_find_reference - Find named reference to a fwnode_handle
489  * @fwnode: Firmware node where to look for the reference
490  * @name: The name of the reference
491  * @index: Index of the reference
492  *
493  * @index can be used when the named reference holds a table of references.
494  *
495  * Returns pointer to the reference fwnode, or ERR_PTR. Caller is responsible to
496  * call fwnode_handle_put() on the returned fwnode pointer.
497  */
498 struct fwnode_handle *fwnode_find_reference(const struct fwnode_handle *fwnode,
499 					    const char *name,
500 					    unsigned int index)
501 {
502 	struct fwnode_reference_args args;
503 	int ret;
504 
505 	ret = fwnode_property_get_reference_args(fwnode, name, NULL, 0, index,
506 						 &args);
507 	return ret ? ERR_PTR(ret) : args.fwnode;
508 }
509 EXPORT_SYMBOL_GPL(fwnode_find_reference);
510 
511 /**
512  * device_remove_properties - Remove properties from a device object.
513  * @dev: Device whose properties to remove.
514  *
515  * The function removes properties previously associated to the device
516  * firmware node with device_add_properties(). Memory allocated to the
517  * properties will also be released.
518  */
519 void device_remove_properties(struct device *dev)
520 {
521 	struct fwnode_handle *fwnode = dev_fwnode(dev);
522 
523 	if (!fwnode)
524 		return;
525 
526 	if (is_software_node(fwnode->secondary)) {
527 		fwnode_remove_software_node(fwnode->secondary);
528 		set_secondary_fwnode(dev, NULL);
529 	}
530 }
531 EXPORT_SYMBOL_GPL(device_remove_properties);
532 
533 /**
534  * device_add_properties - Add a collection of properties to a device object.
535  * @dev: Device to add properties to.
536  * @properties: Collection of properties to add.
537  *
538  * Associate a collection of device properties represented by @properties with
539  * @dev. The function takes a copy of @properties.
540  *
541  * WARNING: The callers should not use this function if it is known that there
542  * is no real firmware node associated with @dev! In that case the callers
543  * should create a software node and assign it to @dev directly.
544  */
545 int device_add_properties(struct device *dev,
546 			  const struct property_entry *properties)
547 {
548 	struct fwnode_handle *fwnode;
549 
550 	fwnode = fwnode_create_software_node(properties, NULL);
551 	if (IS_ERR(fwnode))
552 		return PTR_ERR(fwnode);
553 
554 	set_secondary_fwnode(dev, fwnode);
555 	return 0;
556 }
557 EXPORT_SYMBOL_GPL(device_add_properties);
558 
559 /**
560  * fwnode_get_name - Return the name of a node
561  * @fwnode: The firmware node
562  *
563  * Returns a pointer to the node name.
564  */
565 const char *fwnode_get_name(const struct fwnode_handle *fwnode)
566 {
567 	return fwnode_call_ptr_op(fwnode, get_name);
568 }
569 
570 /**
571  * fwnode_get_name_prefix - Return the prefix of node for printing purposes
572  * @fwnode: The firmware node
573  *
574  * Returns the prefix of a node, intended to be printed right before the node.
575  * The prefix works also as a separator between the nodes.
576  */
577 const char *fwnode_get_name_prefix(const struct fwnode_handle *fwnode)
578 {
579 	return fwnode_call_ptr_op(fwnode, get_name_prefix);
580 }
581 
582 /**
583  * fwnode_get_parent - Return parent firwmare node
584  * @fwnode: Firmware whose parent is retrieved
585  *
586  * Return parent firmware node of the given node if possible or %NULL if no
587  * parent was available.
588  */
589 struct fwnode_handle *fwnode_get_parent(const struct fwnode_handle *fwnode)
590 {
591 	return fwnode_call_ptr_op(fwnode, get_parent);
592 }
593 EXPORT_SYMBOL_GPL(fwnode_get_parent);
594 
595 /**
596  * fwnode_get_next_parent - Iterate to the node's parent
597  * @fwnode: Firmware whose parent is retrieved
598  *
599  * This is like fwnode_get_parent() except that it drops the refcount
600  * on the passed node, making it suitable for iterating through a
601  * node's parents.
602  *
603  * Returns a node pointer with refcount incremented, use
604  * fwnode_handle_node() on it when done.
605  */
606 struct fwnode_handle *fwnode_get_next_parent(struct fwnode_handle *fwnode)
607 {
608 	struct fwnode_handle *parent = fwnode_get_parent(fwnode);
609 
610 	fwnode_handle_put(fwnode);
611 
612 	return parent;
613 }
614 EXPORT_SYMBOL_GPL(fwnode_get_next_parent);
615 
616 /**
617  * fwnode_count_parents - Return the number of parents a node has
618  * @fwnode: The node the parents of which are to be counted
619  *
620  * Returns the number of parents a node has.
621  */
622 unsigned int fwnode_count_parents(const struct fwnode_handle *fwnode)
623 {
624 	struct fwnode_handle *__fwnode;
625 	unsigned int count;
626 
627 	__fwnode = fwnode_get_parent(fwnode);
628 
629 	for (count = 0; __fwnode; count++)
630 		__fwnode = fwnode_get_next_parent(__fwnode);
631 
632 	return count;
633 }
634 EXPORT_SYMBOL_GPL(fwnode_count_parents);
635 
636 /**
637  * fwnode_get_nth_parent - Return an nth parent of a node
638  * @fwnode: The node the parent of which is requested
639  * @depth: Distance of the parent from the node
640  *
641  * Returns the nth parent of a node. If there is no parent at the requested
642  * @depth, %NULL is returned. If @depth is 0, the functionality is equivalent to
643  * fwnode_handle_get(). For @depth == 1, it is fwnode_get_parent() and so on.
644  *
645  * The caller is responsible for calling fwnode_handle_put() for the returned
646  * node.
647  */
648 struct fwnode_handle *fwnode_get_nth_parent(struct fwnode_handle *fwnode,
649 					    unsigned int depth)
650 {
651 	unsigned int i;
652 
653 	fwnode_handle_get(fwnode);
654 
655 	for (i = 0; i < depth && fwnode; i++)
656 		fwnode = fwnode_get_next_parent(fwnode);
657 
658 	return fwnode;
659 }
660 EXPORT_SYMBOL_GPL(fwnode_get_nth_parent);
661 
662 /**
663  * fwnode_get_next_child_node - Return the next child node handle for a node
664  * @fwnode: Firmware node to find the next child node for.
665  * @child: Handle to one of the node's child nodes or a %NULL handle.
666  */
667 struct fwnode_handle *
668 fwnode_get_next_child_node(const struct fwnode_handle *fwnode,
669 			   struct fwnode_handle *child)
670 {
671 	return fwnode_call_ptr_op(fwnode, get_next_child_node, child);
672 }
673 EXPORT_SYMBOL_GPL(fwnode_get_next_child_node);
674 
675 /**
676  * fwnode_get_next_available_child_node - Return the next
677  * available child node handle for a node
678  * @fwnode: Firmware node to find the next child node for.
679  * @child: Handle to one of the node's child nodes or a %NULL handle.
680  */
681 struct fwnode_handle *
682 fwnode_get_next_available_child_node(const struct fwnode_handle *fwnode,
683 				     struct fwnode_handle *child)
684 {
685 	struct fwnode_handle *next_child = child;
686 
687 	if (!fwnode)
688 		return NULL;
689 
690 	do {
691 		next_child = fwnode_get_next_child_node(fwnode, next_child);
692 
693 		if (!next_child || fwnode_device_is_available(next_child))
694 			break;
695 	} while (next_child);
696 
697 	return next_child;
698 }
699 EXPORT_SYMBOL_GPL(fwnode_get_next_available_child_node);
700 
701 /**
702  * device_get_next_child_node - Return the next child node handle for a device
703  * @dev: Device to find the next child node for.
704  * @child: Handle to one of the device's child nodes or a null handle.
705  */
706 struct fwnode_handle *device_get_next_child_node(struct device *dev,
707 						 struct fwnode_handle *child)
708 {
709 	struct acpi_device *adev = ACPI_COMPANION(dev);
710 	struct fwnode_handle *fwnode = NULL;
711 
712 	if (dev->of_node)
713 		fwnode = &dev->of_node->fwnode;
714 	else if (adev)
715 		fwnode = acpi_fwnode_handle(adev);
716 
717 	return fwnode_get_next_child_node(fwnode, child);
718 }
719 EXPORT_SYMBOL_GPL(device_get_next_child_node);
720 
721 /**
722  * fwnode_get_named_child_node - Return first matching named child node handle
723  * @fwnode: Firmware node to find the named child node for.
724  * @childname: String to match child node name against.
725  */
726 struct fwnode_handle *
727 fwnode_get_named_child_node(const struct fwnode_handle *fwnode,
728 			    const char *childname)
729 {
730 	return fwnode_call_ptr_op(fwnode, get_named_child_node, childname);
731 }
732 EXPORT_SYMBOL_GPL(fwnode_get_named_child_node);
733 
734 /**
735  * device_get_named_child_node - Return first matching named child node handle
736  * @dev: Device to find the named child node for.
737  * @childname: String to match child node name against.
738  */
739 struct fwnode_handle *device_get_named_child_node(struct device *dev,
740 						  const char *childname)
741 {
742 	return fwnode_get_named_child_node(dev_fwnode(dev), childname);
743 }
744 EXPORT_SYMBOL_GPL(device_get_named_child_node);
745 
746 /**
747  * fwnode_handle_get - Obtain a reference to a device node
748  * @fwnode: Pointer to the device node to obtain the reference to.
749  *
750  * Returns the fwnode handle.
751  */
752 struct fwnode_handle *fwnode_handle_get(struct fwnode_handle *fwnode)
753 {
754 	if (!fwnode_has_op(fwnode, get))
755 		return fwnode;
756 
757 	return fwnode_call_ptr_op(fwnode, get);
758 }
759 EXPORT_SYMBOL_GPL(fwnode_handle_get);
760 
761 /**
762  * fwnode_handle_put - Drop reference to a device node
763  * @fwnode: Pointer to the device node to drop the reference to.
764  *
765  * This has to be used when terminating device_for_each_child_node() iteration
766  * with break or return to prevent stale device node references from being left
767  * behind.
768  */
769 void fwnode_handle_put(struct fwnode_handle *fwnode)
770 {
771 	fwnode_call_void_op(fwnode, put);
772 }
773 EXPORT_SYMBOL_GPL(fwnode_handle_put);
774 
775 /**
776  * fwnode_device_is_available - check if a device is available for use
777  * @fwnode: Pointer to the fwnode of the device.
778  */
779 bool fwnode_device_is_available(const struct fwnode_handle *fwnode)
780 {
781 	return fwnode_call_bool_op(fwnode, device_is_available);
782 }
783 EXPORT_SYMBOL_GPL(fwnode_device_is_available);
784 
785 /**
786  * device_get_child_node_count - return the number of child nodes for device
787  * @dev: Device to cound the child nodes for
788  */
789 unsigned int device_get_child_node_count(struct device *dev)
790 {
791 	struct fwnode_handle *child;
792 	unsigned int count = 0;
793 
794 	device_for_each_child_node(dev, child)
795 		count++;
796 
797 	return count;
798 }
799 EXPORT_SYMBOL_GPL(device_get_child_node_count);
800 
801 bool device_dma_supported(struct device *dev)
802 {
803 	/* For DT, this is always supported.
804 	 * For ACPI, this depends on CCA, which
805 	 * is determined by the acpi_dma_supported().
806 	 */
807 	if (IS_ENABLED(CONFIG_OF) && dev->of_node)
808 		return true;
809 
810 	return acpi_dma_supported(ACPI_COMPANION(dev));
811 }
812 EXPORT_SYMBOL_GPL(device_dma_supported);
813 
814 enum dev_dma_attr device_get_dma_attr(struct device *dev)
815 {
816 	enum dev_dma_attr attr = DEV_DMA_NOT_SUPPORTED;
817 
818 	if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
819 		if (of_dma_is_coherent(dev->of_node))
820 			attr = DEV_DMA_COHERENT;
821 		else
822 			attr = DEV_DMA_NON_COHERENT;
823 	} else
824 		attr = acpi_get_dma_attr(ACPI_COMPANION(dev));
825 
826 	return attr;
827 }
828 EXPORT_SYMBOL_GPL(device_get_dma_attr);
829 
830 /**
831  * fwnode_get_phy_mode - Get phy mode for given firmware node
832  * @fwnode:	Pointer to the given node
833  *
834  * The function gets phy interface string from property 'phy-mode' or
835  * 'phy-connection-type', and return its index in phy_modes table, or errno in
836  * error case.
837  */
838 int fwnode_get_phy_mode(struct fwnode_handle *fwnode)
839 {
840 	const char *pm;
841 	int err, i;
842 
843 	err = fwnode_property_read_string(fwnode, "phy-mode", &pm);
844 	if (err < 0)
845 		err = fwnode_property_read_string(fwnode,
846 						  "phy-connection-type", &pm);
847 	if (err < 0)
848 		return err;
849 
850 	for (i = 0; i < PHY_INTERFACE_MODE_MAX; i++)
851 		if (!strcasecmp(pm, phy_modes(i)))
852 			return i;
853 
854 	return -ENODEV;
855 }
856 EXPORT_SYMBOL_GPL(fwnode_get_phy_mode);
857 
858 /**
859  * device_get_phy_mode - Get phy mode for given device
860  * @dev:	Pointer to the given device
861  *
862  * The function gets phy interface string from property 'phy-mode' or
863  * 'phy-connection-type', and return its index in phy_modes table, or errno in
864  * error case.
865  */
866 int device_get_phy_mode(struct device *dev)
867 {
868 	return fwnode_get_phy_mode(dev_fwnode(dev));
869 }
870 EXPORT_SYMBOL_GPL(device_get_phy_mode);
871 
872 static void *fwnode_get_mac_addr(struct fwnode_handle *fwnode,
873 				 const char *name, char *addr,
874 				 int alen)
875 {
876 	int ret = fwnode_property_read_u8_array(fwnode, name, addr, alen);
877 
878 	if (ret == 0 && alen == ETH_ALEN && is_valid_ether_addr(addr))
879 		return addr;
880 	return NULL;
881 }
882 
883 /**
884  * fwnode_get_mac_address - Get the MAC from the firmware node
885  * @fwnode:	Pointer to the firmware node
886  * @addr:	Address of buffer to store the MAC in
887  * @alen:	Length of the buffer pointed to by addr, should be ETH_ALEN
888  *
889  * Search the firmware node for the best MAC address to use.  'mac-address' is
890  * checked first, because that is supposed to contain to "most recent" MAC
891  * address. If that isn't set, then 'local-mac-address' is checked next,
892  * because that is the default address.  If that isn't set, then the obsolete
893  * 'address' is checked, just in case we're using an old device tree.
894  *
895  * Note that the 'address' property is supposed to contain a virtual address of
896  * the register set, but some DTS files have redefined that property to be the
897  * MAC address.
898  *
899  * All-zero MAC addresses are rejected, because those could be properties that
900  * exist in the firmware tables, but were not updated by the firmware.  For
901  * example, the DTS could define 'mac-address' and 'local-mac-address', with
902  * zero MAC addresses.  Some older U-Boots only initialized 'local-mac-address'.
903  * In this case, the real MAC is in 'local-mac-address', and 'mac-address'
904  * exists but is all zeros.
905 */
906 void *fwnode_get_mac_address(struct fwnode_handle *fwnode, char *addr, int alen)
907 {
908 	char *res;
909 
910 	res = fwnode_get_mac_addr(fwnode, "mac-address", addr, alen);
911 	if (res)
912 		return res;
913 
914 	res = fwnode_get_mac_addr(fwnode, "local-mac-address", addr, alen);
915 	if (res)
916 		return res;
917 
918 	return fwnode_get_mac_addr(fwnode, "address", addr, alen);
919 }
920 EXPORT_SYMBOL(fwnode_get_mac_address);
921 
922 /**
923  * device_get_mac_address - Get the MAC for a given device
924  * @dev:	Pointer to the device
925  * @addr:	Address of buffer to store the MAC in
926  * @alen:	Length of the buffer pointed to by addr, should be ETH_ALEN
927  */
928 void *device_get_mac_address(struct device *dev, char *addr, int alen)
929 {
930 	return fwnode_get_mac_address(dev_fwnode(dev), addr, alen);
931 }
932 EXPORT_SYMBOL(device_get_mac_address);
933 
934 /**
935  * fwnode_irq_get - Get IRQ directly from a fwnode
936  * @fwnode:	Pointer to the firmware node
937  * @index:	Zero-based index of the IRQ
938  *
939  * Returns Linux IRQ number on success. Other values are determined
940  * accordingly to acpi_/of_ irq_get() operation.
941  */
942 int fwnode_irq_get(struct fwnode_handle *fwnode, unsigned int index)
943 {
944 	struct device_node *of_node = to_of_node(fwnode);
945 	struct resource res;
946 	int ret;
947 
948 	if (IS_ENABLED(CONFIG_OF) && of_node)
949 		return of_irq_get(of_node, index);
950 
951 	ret = acpi_irq_get(ACPI_HANDLE_FWNODE(fwnode), index, &res);
952 	if (ret)
953 		return ret;
954 
955 	return res.start;
956 }
957 EXPORT_SYMBOL(fwnode_irq_get);
958 
959 /**
960  * fwnode_graph_get_next_endpoint - Get next endpoint firmware node
961  * @fwnode: Pointer to the parent firmware node
962  * @prev: Previous endpoint node or %NULL to get the first
963  *
964  * Returns an endpoint firmware node pointer or %NULL if no more endpoints
965  * are available.
966  */
967 struct fwnode_handle *
968 fwnode_graph_get_next_endpoint(const struct fwnode_handle *fwnode,
969 			       struct fwnode_handle *prev)
970 {
971 	return fwnode_call_ptr_op(fwnode, graph_get_next_endpoint, prev);
972 }
973 EXPORT_SYMBOL_GPL(fwnode_graph_get_next_endpoint);
974 
975 /**
976  * fwnode_graph_get_port_parent - Return the device fwnode of a port endpoint
977  * @endpoint: Endpoint firmware node of the port
978  *
979  * Return: the firmware node of the device the @endpoint belongs to.
980  */
981 struct fwnode_handle *
982 fwnode_graph_get_port_parent(const struct fwnode_handle *endpoint)
983 {
984 	struct fwnode_handle *port, *parent;
985 
986 	port = fwnode_get_parent(endpoint);
987 	parent = fwnode_call_ptr_op(port, graph_get_port_parent);
988 
989 	fwnode_handle_put(port);
990 
991 	return parent;
992 }
993 EXPORT_SYMBOL_GPL(fwnode_graph_get_port_parent);
994 
995 /**
996  * fwnode_graph_get_remote_port_parent - Return fwnode of a remote device
997  * @fwnode: Endpoint firmware node pointing to the remote endpoint
998  *
999  * Extracts firmware node of a remote device the @fwnode points to.
1000  */
1001 struct fwnode_handle *
1002 fwnode_graph_get_remote_port_parent(const struct fwnode_handle *fwnode)
1003 {
1004 	struct fwnode_handle *endpoint, *parent;
1005 
1006 	endpoint = fwnode_graph_get_remote_endpoint(fwnode);
1007 	parent = fwnode_graph_get_port_parent(endpoint);
1008 
1009 	fwnode_handle_put(endpoint);
1010 
1011 	return parent;
1012 }
1013 EXPORT_SYMBOL_GPL(fwnode_graph_get_remote_port_parent);
1014 
1015 /**
1016  * fwnode_graph_get_remote_port - Return fwnode of a remote port
1017  * @fwnode: Endpoint firmware node pointing to the remote endpoint
1018  *
1019  * Extracts firmware node of a remote port the @fwnode points to.
1020  */
1021 struct fwnode_handle *
1022 fwnode_graph_get_remote_port(const struct fwnode_handle *fwnode)
1023 {
1024 	return fwnode_get_next_parent(fwnode_graph_get_remote_endpoint(fwnode));
1025 }
1026 EXPORT_SYMBOL_GPL(fwnode_graph_get_remote_port);
1027 
1028 /**
1029  * fwnode_graph_get_remote_endpoint - Return fwnode of a remote endpoint
1030  * @fwnode: Endpoint firmware node pointing to the remote endpoint
1031  *
1032  * Extracts firmware node of a remote endpoint the @fwnode points to.
1033  */
1034 struct fwnode_handle *
1035 fwnode_graph_get_remote_endpoint(const struct fwnode_handle *fwnode)
1036 {
1037 	return fwnode_call_ptr_op(fwnode, graph_get_remote_endpoint);
1038 }
1039 EXPORT_SYMBOL_GPL(fwnode_graph_get_remote_endpoint);
1040 
1041 /**
1042  * fwnode_graph_get_remote_node - get remote parent node for given port/endpoint
1043  * @fwnode: pointer to parent fwnode_handle containing graph port/endpoint
1044  * @port_id: identifier of the parent port node
1045  * @endpoint_id: identifier of the endpoint node
1046  *
1047  * Return: Remote fwnode handle associated with remote endpoint node linked
1048  *	   to @node. Use fwnode_node_put() on it when done.
1049  */
1050 struct fwnode_handle *
1051 fwnode_graph_get_remote_node(const struct fwnode_handle *fwnode, u32 port_id,
1052 			     u32 endpoint_id)
1053 {
1054 	struct fwnode_handle *endpoint = NULL;
1055 
1056 	while ((endpoint = fwnode_graph_get_next_endpoint(fwnode, endpoint))) {
1057 		struct fwnode_endpoint fwnode_ep;
1058 		struct fwnode_handle *remote;
1059 		int ret;
1060 
1061 		ret = fwnode_graph_parse_endpoint(endpoint, &fwnode_ep);
1062 		if (ret < 0)
1063 			continue;
1064 
1065 		if (fwnode_ep.port != port_id || fwnode_ep.id != endpoint_id)
1066 			continue;
1067 
1068 		remote = fwnode_graph_get_remote_port_parent(endpoint);
1069 		if (!remote)
1070 			return NULL;
1071 
1072 		return fwnode_device_is_available(remote) ? remote : NULL;
1073 	}
1074 
1075 	return NULL;
1076 }
1077 EXPORT_SYMBOL_GPL(fwnode_graph_get_remote_node);
1078 
1079 /**
1080  * fwnode_graph_get_endpoint_by_id - get endpoint by port and endpoint numbers
1081  * @fwnode: parent fwnode_handle containing the graph
1082  * @port: identifier of the port node
1083  * @endpoint: identifier of the endpoint node under the port node
1084  * @flags: fwnode lookup flags
1085  *
1086  * Return the fwnode handle of the local endpoint corresponding the port and
1087  * endpoint IDs or NULL if not found.
1088  *
1089  * If FWNODE_GRAPH_ENDPOINT_NEXT is passed in @flags and the specified endpoint
1090  * has not been found, look for the closest endpoint ID greater than the
1091  * specified one and return the endpoint that corresponds to it, if present.
1092  *
1093  * Do not return endpoints that belong to disabled devices, unless
1094  * FWNODE_GRAPH_DEVICE_DISABLED is passed in @flags.
1095  *
1096  * The returned endpoint needs to be released by calling fwnode_handle_put() on
1097  * it when it is not needed any more.
1098  */
1099 struct fwnode_handle *
1100 fwnode_graph_get_endpoint_by_id(const struct fwnode_handle *fwnode,
1101 				u32 port, u32 endpoint, unsigned long flags)
1102 {
1103 	struct fwnode_handle *ep = NULL, *best_ep = NULL;
1104 	unsigned int best_ep_id = 0;
1105 	bool endpoint_next = flags & FWNODE_GRAPH_ENDPOINT_NEXT;
1106 	bool enabled_only = !(flags & FWNODE_GRAPH_DEVICE_DISABLED);
1107 
1108 	while ((ep = fwnode_graph_get_next_endpoint(fwnode, ep))) {
1109 		struct fwnode_endpoint fwnode_ep = { 0 };
1110 		int ret;
1111 
1112 		if (enabled_only) {
1113 			struct fwnode_handle *dev_node;
1114 			bool available;
1115 
1116 			dev_node = fwnode_graph_get_remote_port_parent(ep);
1117 			available = fwnode_device_is_available(dev_node);
1118 			fwnode_handle_put(dev_node);
1119 			if (!available)
1120 				continue;
1121 		}
1122 
1123 		ret = fwnode_graph_parse_endpoint(ep, &fwnode_ep);
1124 		if (ret < 0)
1125 			continue;
1126 
1127 		if (fwnode_ep.port != port)
1128 			continue;
1129 
1130 		if (fwnode_ep.id == endpoint)
1131 			return ep;
1132 
1133 		if (!endpoint_next)
1134 			continue;
1135 
1136 		/*
1137 		 * If the endpoint that has just been found is not the first
1138 		 * matching one and the ID of the one found previously is closer
1139 		 * to the requested endpoint ID, skip it.
1140 		 */
1141 		if (fwnode_ep.id < endpoint ||
1142 		    (best_ep && best_ep_id < fwnode_ep.id))
1143 			continue;
1144 
1145 		fwnode_handle_put(best_ep);
1146 		best_ep = fwnode_handle_get(ep);
1147 		best_ep_id = fwnode_ep.id;
1148 	}
1149 
1150 	return best_ep;
1151 }
1152 EXPORT_SYMBOL_GPL(fwnode_graph_get_endpoint_by_id);
1153 
1154 /**
1155  * fwnode_graph_parse_endpoint - parse common endpoint node properties
1156  * @fwnode: pointer to endpoint fwnode_handle
1157  * @endpoint: pointer to the fwnode endpoint data structure
1158  *
1159  * Parse @fwnode representing a graph endpoint node and store the
1160  * information in @endpoint. The caller must hold a reference to
1161  * @fwnode.
1162  */
1163 int fwnode_graph_parse_endpoint(const struct fwnode_handle *fwnode,
1164 				struct fwnode_endpoint *endpoint)
1165 {
1166 	memset(endpoint, 0, sizeof(*endpoint));
1167 
1168 	return fwnode_call_int_op(fwnode, graph_parse_endpoint, endpoint);
1169 }
1170 EXPORT_SYMBOL(fwnode_graph_parse_endpoint);
1171 
1172 const void *device_get_match_data(struct device *dev)
1173 {
1174 	return fwnode_call_ptr_op(dev_fwnode(dev), device_get_match_data, dev);
1175 }
1176 EXPORT_SYMBOL_GPL(device_get_match_data);
1177