xref: /openbmc/linux/drivers/base/property.c (revision 20e8ef5c)
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/phy.h>
19 
20 struct fwnode_handle *dev_fwnode(struct device *dev)
21 {
22 	return IS_ENABLED(CONFIG_OF) && dev->of_node ?
23 		of_fwnode_handle(dev->of_node) : dev->fwnode;
24 }
25 EXPORT_SYMBOL_GPL(dev_fwnode);
26 
27 /**
28  * device_property_present - check if a property of a device is present
29  * @dev: Device whose property is being checked
30  * @propname: Name of the property
31  *
32  * Check if property @propname is present in the device firmware description.
33  */
34 bool device_property_present(struct device *dev, const char *propname)
35 {
36 	return fwnode_property_present(dev_fwnode(dev), propname);
37 }
38 EXPORT_SYMBOL_GPL(device_property_present);
39 
40 /**
41  * fwnode_property_present - check if a property of a firmware node is present
42  * @fwnode: Firmware node whose property to check
43  * @propname: Name of the property
44  */
45 bool fwnode_property_present(const struct fwnode_handle *fwnode,
46 			     const char *propname)
47 {
48 	bool ret;
49 
50 	ret = fwnode_call_bool_op(fwnode, property_present, propname);
51 	if (ret == false && !IS_ERR_OR_NULL(fwnode) &&
52 	    !IS_ERR_OR_NULL(fwnode->secondary))
53 		ret = fwnode_call_bool_op(fwnode->secondary, property_present,
54 					 propname);
55 	return ret;
56 }
57 EXPORT_SYMBOL_GPL(fwnode_property_present);
58 
59 /**
60  * device_property_read_u8_array - return a u8 array property of a device
61  * @dev: Device to get the property of
62  * @propname: Name of the property
63  * @val: The values are stored here or %NULL to return the number of values
64  * @nval: Size of the @val array
65  *
66  * Function reads an array of u8 properties with @propname from the device
67  * firmware description and stores them to @val if found.
68  *
69  * Return: number of values if @val was %NULL,
70  *         %0 if the property was found (success),
71  *	   %-EINVAL if given arguments are not valid,
72  *	   %-ENODATA if the property does not have a value,
73  *	   %-EPROTO if the property is not an array of numbers,
74  *	   %-EOVERFLOW if the size of the property is not as expected.
75  *	   %-ENXIO if no suitable firmware interface is present.
76  */
77 int device_property_read_u8_array(struct device *dev, const char *propname,
78 				  u8 *val, size_t nval)
79 {
80 	return fwnode_property_read_u8_array(dev_fwnode(dev), propname, val, nval);
81 }
82 EXPORT_SYMBOL_GPL(device_property_read_u8_array);
83 
84 /**
85  * device_property_read_u16_array - return a u16 array property of a device
86  * @dev: Device to get the property of
87  * @propname: Name of the property
88  * @val: The values are stored here or %NULL to return the number of values
89  * @nval: Size of the @val array
90  *
91  * Function reads an array of u16 properties with @propname from the device
92  * firmware description and stores them to @val if found.
93  *
94  * Return: number of values if @val was %NULL,
95  *         %0 if the property was found (success),
96  *	   %-EINVAL if given arguments are not valid,
97  *	   %-ENODATA if the property does not have a value,
98  *	   %-EPROTO if the property is not an array of numbers,
99  *	   %-EOVERFLOW if the size of the property is not as expected.
100  *	   %-ENXIO if no suitable firmware interface is present.
101  */
102 int device_property_read_u16_array(struct device *dev, const char *propname,
103 				   u16 *val, size_t nval)
104 {
105 	return fwnode_property_read_u16_array(dev_fwnode(dev), propname, val, nval);
106 }
107 EXPORT_SYMBOL_GPL(device_property_read_u16_array);
108 
109 /**
110  * device_property_read_u32_array - return a u32 array property of a device
111  * @dev: Device to get the property of
112  * @propname: Name of the property
113  * @val: The values are stored here or %NULL to return the number of values
114  * @nval: Size of the @val array
115  *
116  * Function reads an array of u32 properties with @propname from the device
117  * firmware description and stores them to @val if found.
118  *
119  * Return: number of values if @val was %NULL,
120  *         %0 if the property was found (success),
121  *	   %-EINVAL if given arguments are not valid,
122  *	   %-ENODATA if the property does not have a value,
123  *	   %-EPROTO if the property is not an array of numbers,
124  *	   %-EOVERFLOW if the size of the property is not as expected.
125  *	   %-ENXIO if no suitable firmware interface is present.
126  */
127 int device_property_read_u32_array(struct device *dev, const char *propname,
128 				   u32 *val, size_t nval)
129 {
130 	return fwnode_property_read_u32_array(dev_fwnode(dev), propname, val, nval);
131 }
132 EXPORT_SYMBOL_GPL(device_property_read_u32_array);
133 
134 /**
135  * device_property_read_u64_array - return a u64 array property of a device
136  * @dev: Device to get the property of
137  * @propname: Name of the property
138  * @val: The values are stored here or %NULL to return the number of values
139  * @nval: Size of the @val array
140  *
141  * Function reads an array of u64 properties with @propname from the device
142  * firmware description and stores them to @val if found.
143  *
144  * Return: number of values if @val was %NULL,
145  *         %0 if the property was found (success),
146  *	   %-EINVAL if given arguments are not valid,
147  *	   %-ENODATA if the property does not have a value,
148  *	   %-EPROTO if the property is not an array of numbers,
149  *	   %-EOVERFLOW if the size of the property is not as expected.
150  *	   %-ENXIO if no suitable firmware interface is present.
151  */
152 int device_property_read_u64_array(struct device *dev, const char *propname,
153 				   u64 *val, size_t nval)
154 {
155 	return fwnode_property_read_u64_array(dev_fwnode(dev), propname, val, nval);
156 }
157 EXPORT_SYMBOL_GPL(device_property_read_u64_array);
158 
159 /**
160  * device_property_read_string_array - return a string array property of device
161  * @dev: Device to get the property of
162  * @propname: Name of the property
163  * @val: The values are stored here or %NULL to return the number of values
164  * @nval: Size of the @val array
165  *
166  * Function reads an array of string properties with @propname from the device
167  * firmware description and stores them to @val if found.
168  *
169  * Return: number of values read on success if @val is non-NULL,
170  *	   number of values available on success if @val is NULL,
171  *	   %-EINVAL if given arguments are not valid,
172  *	   %-ENODATA if the property does not have a value,
173  *	   %-EPROTO or %-EILSEQ if the property is not an array of strings,
174  *	   %-EOVERFLOW if the size of the property is not as expected.
175  *	   %-ENXIO if no suitable firmware interface is present.
176  */
177 int device_property_read_string_array(struct device *dev, const char *propname,
178 				      const char **val, size_t nval)
179 {
180 	return fwnode_property_read_string_array(dev_fwnode(dev), propname, val, nval);
181 }
182 EXPORT_SYMBOL_GPL(device_property_read_string_array);
183 
184 /**
185  * device_property_read_string - return a string property of a device
186  * @dev: Device to get the property of
187  * @propname: Name of the property
188  * @val: The value is stored here
189  *
190  * Function reads property @propname from the device firmware description and
191  * stores the value into @val if found. The value is checked to be a string.
192  *
193  * Return: %0 if the property was found (success),
194  *	   %-EINVAL if given arguments are not valid,
195  *	   %-ENODATA if the property does not have a value,
196  *	   %-EPROTO or %-EILSEQ if the property type is not a string.
197  *	   %-ENXIO if no suitable firmware interface is present.
198  */
199 int device_property_read_string(struct device *dev, const char *propname,
200 				const char **val)
201 {
202 	return fwnode_property_read_string(dev_fwnode(dev), propname, val);
203 }
204 EXPORT_SYMBOL_GPL(device_property_read_string);
205 
206 /**
207  * device_property_match_string - find a string in an array and return index
208  * @dev: Device to get the property of
209  * @propname: Name of the property holding the array
210  * @string: String to look for
211  *
212  * Find a given string in a string array and if it is found return the
213  * index back.
214  *
215  * Return: %0 if the property was found (success),
216  *	   %-EINVAL if given arguments are not valid,
217  *	   %-ENODATA if the property does not have a value,
218  *	   %-EPROTO if the property is not an array of strings,
219  *	   %-ENXIO if no suitable firmware interface is present.
220  */
221 int device_property_match_string(struct device *dev, const char *propname,
222 				 const char *string)
223 {
224 	return fwnode_property_match_string(dev_fwnode(dev), propname, string);
225 }
226 EXPORT_SYMBOL_GPL(device_property_match_string);
227 
228 static int fwnode_property_read_int_array(const struct fwnode_handle *fwnode,
229 					  const char *propname,
230 					  unsigned int elem_size, void *val,
231 					  size_t nval)
232 {
233 	int ret;
234 
235 	ret = fwnode_call_int_op(fwnode, property_read_int_array, propname,
236 				 elem_size, val, nval);
237 	if (ret == -EINVAL && !IS_ERR_OR_NULL(fwnode) &&
238 	    !IS_ERR_OR_NULL(fwnode->secondary))
239 		ret = fwnode_call_int_op(
240 			fwnode->secondary, property_read_int_array, propname,
241 			elem_size, val, nval);
242 
243 	return ret;
244 }
245 
246 /**
247  * fwnode_property_read_u8_array - return a u8 array property of firmware node
248  * @fwnode: Firmware node to get the property of
249  * @propname: Name of the property
250  * @val: The values are stored here or %NULL to return the number of values
251  * @nval: Size of the @val array
252  *
253  * Read an array of u8 properties with @propname from @fwnode and stores them to
254  * @val if found.
255  *
256  * Return: number of values if @val was %NULL,
257  *         %0 if the property was found (success),
258  *	   %-EINVAL if given arguments are not valid,
259  *	   %-ENODATA if the property does not have a value,
260  *	   %-EPROTO if the property is not an array of numbers,
261  *	   %-EOVERFLOW if the size of the property is not as expected,
262  *	   %-ENXIO if no suitable firmware interface is present.
263  */
264 int fwnode_property_read_u8_array(const struct fwnode_handle *fwnode,
265 				  const char *propname, u8 *val, size_t nval)
266 {
267 	return fwnode_property_read_int_array(fwnode, propname, sizeof(u8),
268 					      val, nval);
269 }
270 EXPORT_SYMBOL_GPL(fwnode_property_read_u8_array);
271 
272 /**
273  * fwnode_property_read_u16_array - return a u16 array property of firmware node
274  * @fwnode: Firmware node to get the property of
275  * @propname: Name of the property
276  * @val: The values are stored here or %NULL to return the number of values
277  * @nval: Size of the @val array
278  *
279  * Read an array of u16 properties with @propname from @fwnode and store them to
280  * @val if found.
281  *
282  * Return: number of values if @val was %NULL,
283  *         %0 if the property was found (success),
284  *	   %-EINVAL if given arguments are not valid,
285  *	   %-ENODATA if the property does not have a value,
286  *	   %-EPROTO if the property is not an array of numbers,
287  *	   %-EOVERFLOW if the size of the property is not as expected,
288  *	   %-ENXIO if no suitable firmware interface is present.
289  */
290 int fwnode_property_read_u16_array(const struct fwnode_handle *fwnode,
291 				   const char *propname, u16 *val, size_t nval)
292 {
293 	return fwnode_property_read_int_array(fwnode, propname, sizeof(u16),
294 					      val, nval);
295 }
296 EXPORT_SYMBOL_GPL(fwnode_property_read_u16_array);
297 
298 /**
299  * fwnode_property_read_u32_array - return a u32 array property of firmware node
300  * @fwnode: Firmware node to get the property of
301  * @propname: Name of the property
302  * @val: The values are stored here or %NULL to return the number of values
303  * @nval: Size of the @val array
304  *
305  * Read an array of u32 properties with @propname from @fwnode store them to
306  * @val if found.
307  *
308  * Return: number of values if @val was %NULL,
309  *         %0 if the property was found (success),
310  *	   %-EINVAL if given arguments are not valid,
311  *	   %-ENODATA if the property does not have a value,
312  *	   %-EPROTO if the property is not an array of numbers,
313  *	   %-EOVERFLOW if the size of the property is not as expected,
314  *	   %-ENXIO if no suitable firmware interface is present.
315  */
316 int fwnode_property_read_u32_array(const struct fwnode_handle *fwnode,
317 				   const char *propname, u32 *val, size_t nval)
318 {
319 	return fwnode_property_read_int_array(fwnode, propname, sizeof(u32),
320 					      val, nval);
321 }
322 EXPORT_SYMBOL_GPL(fwnode_property_read_u32_array);
323 
324 /**
325  * fwnode_property_read_u64_array - return a u64 array property firmware node
326  * @fwnode: Firmware node to get the property of
327  * @propname: Name of the property
328  * @val: The values are stored here or %NULL to return the number of values
329  * @nval: Size of the @val array
330  *
331  * Read an array of u64 properties with @propname from @fwnode and store them to
332  * @val if found.
333  *
334  * Return: number of values if @val was %NULL,
335  *         %0 if the property was found (success),
336  *	   %-EINVAL if given arguments are not valid,
337  *	   %-ENODATA if the property does not have a value,
338  *	   %-EPROTO if the property is not an array of numbers,
339  *	   %-EOVERFLOW if the size of the property is not as expected,
340  *	   %-ENXIO if no suitable firmware interface is present.
341  */
342 int fwnode_property_read_u64_array(const struct fwnode_handle *fwnode,
343 				   const char *propname, u64 *val, size_t nval)
344 {
345 	return fwnode_property_read_int_array(fwnode, propname, sizeof(u64),
346 					      val, nval);
347 }
348 EXPORT_SYMBOL_GPL(fwnode_property_read_u64_array);
349 
350 /**
351  * fwnode_property_read_string_array - return string array property of a node
352  * @fwnode: Firmware node to get the property of
353  * @propname: Name of the property
354  * @val: The values are stored here or %NULL to return the number of values
355  * @nval: Size of the @val array
356  *
357  * Read an string list property @propname from the given firmware node and store
358  * them to @val if found.
359  *
360  * Return: number of values read on success if @val is non-NULL,
361  *	   number of values available on success if @val is NULL,
362  *	   %-EINVAL if given arguments are not valid,
363  *	   %-ENODATA if the property does not have a value,
364  *	   %-EPROTO or %-EILSEQ if the property is not an array of strings,
365  *	   %-EOVERFLOW if the size of the property is not as expected,
366  *	   %-ENXIO if no suitable firmware interface is present.
367  */
368 int fwnode_property_read_string_array(const struct fwnode_handle *fwnode,
369 				      const char *propname, const char **val,
370 				      size_t nval)
371 {
372 	int ret;
373 
374 	ret = fwnode_call_int_op(fwnode, property_read_string_array, propname,
375 				 val, nval);
376 	if (ret == -EINVAL && !IS_ERR_OR_NULL(fwnode) &&
377 	    !IS_ERR_OR_NULL(fwnode->secondary))
378 		ret = fwnode_call_int_op(fwnode->secondary,
379 					 property_read_string_array, propname,
380 					 val, nval);
381 	return ret;
382 }
383 EXPORT_SYMBOL_GPL(fwnode_property_read_string_array);
384 
385 /**
386  * fwnode_property_read_string - return a string property of a firmware node
387  * @fwnode: Firmware node to get the property of
388  * @propname: Name of the property
389  * @val: The value is stored here
390  *
391  * Read property @propname from the given firmware node and store the value into
392  * @val if found.  The value is checked to be a string.
393  *
394  * Return: %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 or %-EILSEQ if the property is not a string,
398  *	   %-ENXIO if no suitable firmware interface is present.
399  */
400 int fwnode_property_read_string(const struct fwnode_handle *fwnode,
401 				const char *propname, const char **val)
402 {
403 	int ret = fwnode_property_read_string_array(fwnode, propname, val, 1);
404 
405 	return ret < 0 ? ret : 0;
406 }
407 EXPORT_SYMBOL_GPL(fwnode_property_read_string);
408 
409 /**
410  * fwnode_property_match_string - find a string in an array and return index
411  * @fwnode: Firmware node to get the property of
412  * @propname: Name of the property holding the array
413  * @string: String to look for
414  *
415  * Find a given string in a string array and if it is found return the
416  * index back.
417  *
418  * Return: %0 if the property was found (success),
419  *	   %-EINVAL if given arguments are not valid,
420  *	   %-ENODATA if the property does not have a value,
421  *	   %-EPROTO if the property is not an array of strings,
422  *	   %-ENXIO if no suitable firmware interface is present.
423  */
424 int fwnode_property_match_string(const struct fwnode_handle *fwnode,
425 	const char *propname, const char *string)
426 {
427 	const char **values;
428 	int nval, ret;
429 
430 	nval = fwnode_property_read_string_array(fwnode, propname, NULL, 0);
431 	if (nval < 0)
432 		return nval;
433 
434 	if (nval == 0)
435 		return -ENODATA;
436 
437 	values = kcalloc(nval, sizeof(*values), GFP_KERNEL);
438 	if (!values)
439 		return -ENOMEM;
440 
441 	ret = fwnode_property_read_string_array(fwnode, propname, values, nval);
442 	if (ret < 0)
443 		goto out;
444 
445 	ret = match_string(values, nval, string);
446 	if (ret < 0)
447 		ret = -ENODATA;
448 out:
449 	kfree(values);
450 	return ret;
451 }
452 EXPORT_SYMBOL_GPL(fwnode_property_match_string);
453 
454 /**
455  * fwnode_property_get_reference_args() - Find a reference with arguments
456  * @fwnode:	Firmware node where to look for the reference
457  * @prop:	The name of the property
458  * @nargs_prop:	The name of the property telling the number of
459  *		arguments in the referred node. NULL if @nargs is known,
460  *		otherwise @nargs is ignored. Only relevant on OF.
461  * @nargs:	Number of arguments. Ignored if @nargs_prop is non-NULL.
462  * @index:	Index of the reference, from zero onwards.
463  * @args:	Result structure with reference and integer arguments.
464  *
465  * Obtain a reference based on a named property in an fwnode, with
466  * integer arguments.
467  *
468  * Caller is responsible to call fwnode_handle_put() on the returned
469  * args->fwnode pointer.
470  *
471  * Returns: %0 on success
472  *	    %-ENOENT when the index is out of bounds, the index has an empty
473  *		     reference or the property was not found
474  *	    %-EINVAL on parse error
475  */
476 int fwnode_property_get_reference_args(const struct fwnode_handle *fwnode,
477 				       const char *prop, const char *nargs_prop,
478 				       unsigned int nargs, unsigned int index,
479 				       struct fwnode_reference_args *args)
480 {
481 	int ret;
482 
483 	ret = fwnode_call_int_op(fwnode, get_reference_args, prop, nargs_prop,
484 				 nargs, index, args);
485 
486 	if (ret < 0 && !IS_ERR_OR_NULL(fwnode) &&
487 	    !IS_ERR_OR_NULL(fwnode->secondary))
488 		ret = fwnode_call_int_op(fwnode->secondary, get_reference_args,
489 					 prop, nargs_prop, nargs, index, args);
490 
491 	return ret;
492 }
493 EXPORT_SYMBOL_GPL(fwnode_property_get_reference_args);
494 
495 /**
496  * fwnode_find_reference - Find named reference to a fwnode_handle
497  * @fwnode: Firmware node where to look for the reference
498  * @name: The name of the reference
499  * @index: Index of the reference
500  *
501  * @index can be used when the named reference holds a table of references.
502  *
503  * Returns pointer to the reference fwnode, or ERR_PTR. Caller is responsible to
504  * call fwnode_handle_put() on the returned fwnode pointer.
505  */
506 struct fwnode_handle *fwnode_find_reference(const struct fwnode_handle *fwnode,
507 					    const char *name,
508 					    unsigned int index)
509 {
510 	struct fwnode_reference_args args;
511 	int ret;
512 
513 	ret = fwnode_property_get_reference_args(fwnode, name, NULL, 0, index,
514 						 &args);
515 	return ret ? ERR_PTR(ret) : args.fwnode;
516 }
517 EXPORT_SYMBOL_GPL(fwnode_find_reference);
518 
519 /**
520  * fwnode_get_name - Return the name of a node
521  * @fwnode: The firmware node
522  *
523  * Returns a pointer to the node name.
524  */
525 const char *fwnode_get_name(const struct fwnode_handle *fwnode)
526 {
527 	return fwnode_call_ptr_op(fwnode, get_name);
528 }
529 EXPORT_SYMBOL_GPL(fwnode_get_name);
530 
531 /**
532  * fwnode_get_name_prefix - Return the prefix of node for printing purposes
533  * @fwnode: The firmware node
534  *
535  * Returns the prefix of a node, intended to be printed right before the node.
536  * The prefix works also as a separator between the nodes.
537  */
538 const char *fwnode_get_name_prefix(const struct fwnode_handle *fwnode)
539 {
540 	return fwnode_call_ptr_op(fwnode, get_name_prefix);
541 }
542 
543 /**
544  * fwnode_get_parent - Return parent firwmare node
545  * @fwnode: Firmware whose parent is retrieved
546  *
547  * Return parent firmware node of the given node if possible or %NULL if no
548  * parent was available.
549  */
550 struct fwnode_handle *fwnode_get_parent(const struct fwnode_handle *fwnode)
551 {
552 	return fwnode_call_ptr_op(fwnode, get_parent);
553 }
554 EXPORT_SYMBOL_GPL(fwnode_get_parent);
555 
556 /**
557  * fwnode_get_next_parent - Iterate to the node's parent
558  * @fwnode: Firmware whose parent is retrieved
559  *
560  * This is like fwnode_get_parent() except that it drops the refcount
561  * on the passed node, making it suitable for iterating through a
562  * node's parents.
563  *
564  * Returns a node pointer with refcount incremented, use
565  * fwnode_handle_node() on it when done.
566  */
567 struct fwnode_handle *fwnode_get_next_parent(struct fwnode_handle *fwnode)
568 {
569 	struct fwnode_handle *parent = fwnode_get_parent(fwnode);
570 
571 	fwnode_handle_put(fwnode);
572 
573 	return parent;
574 }
575 EXPORT_SYMBOL_GPL(fwnode_get_next_parent);
576 
577 /**
578  * fwnode_get_next_parent_dev - Find device of closest ancestor fwnode
579  * @fwnode: firmware node
580  *
581  * Given a firmware node (@fwnode), this function finds its closest ancestor
582  * firmware node that has a corresponding struct device and returns that struct
583  * device.
584  *
585  * The caller of this function is expected to call put_device() on the returned
586  * device when they are done.
587  */
588 struct device *fwnode_get_next_parent_dev(struct fwnode_handle *fwnode)
589 {
590 	struct device *dev;
591 
592 	fwnode_handle_get(fwnode);
593 	do {
594 		fwnode = fwnode_get_next_parent(fwnode);
595 		if (!fwnode)
596 			return NULL;
597 		dev = get_dev_from_fwnode(fwnode);
598 	} while (!dev);
599 	fwnode_handle_put(fwnode);
600 	return dev;
601 }
602 
603 /**
604  * fwnode_count_parents - Return the number of parents a node has
605  * @fwnode: The node the parents of which are to be counted
606  *
607  * Returns the number of parents a node has.
608  */
609 unsigned int fwnode_count_parents(const struct fwnode_handle *fwnode)
610 {
611 	struct fwnode_handle *__fwnode;
612 	unsigned int count;
613 
614 	__fwnode = fwnode_get_parent(fwnode);
615 
616 	for (count = 0; __fwnode; count++)
617 		__fwnode = fwnode_get_next_parent(__fwnode);
618 
619 	return count;
620 }
621 EXPORT_SYMBOL_GPL(fwnode_count_parents);
622 
623 /**
624  * fwnode_get_nth_parent - Return an nth parent of a node
625  * @fwnode: The node the parent of which is requested
626  * @depth: Distance of the parent from the node
627  *
628  * Returns the nth parent of a node. If there is no parent at the requested
629  * @depth, %NULL is returned. If @depth is 0, the functionality is equivalent to
630  * fwnode_handle_get(). For @depth == 1, it is fwnode_get_parent() and so on.
631  *
632  * The caller is responsible for calling fwnode_handle_put() for the returned
633  * node.
634  */
635 struct fwnode_handle *fwnode_get_nth_parent(struct fwnode_handle *fwnode,
636 					    unsigned int depth)
637 {
638 	unsigned int i;
639 
640 	fwnode_handle_get(fwnode);
641 
642 	for (i = 0; i < depth && fwnode; i++)
643 		fwnode = fwnode_get_next_parent(fwnode);
644 
645 	return fwnode;
646 }
647 EXPORT_SYMBOL_GPL(fwnode_get_nth_parent);
648 
649 /**
650  * fwnode_is_ancestor_of - Test if @test_ancestor is ancestor of @test_child
651  * @test_ancestor: Firmware which is tested for being an ancestor
652  * @test_child: Firmware which is tested for being the child
653  *
654  * A node is considered an ancestor of itself too.
655  *
656  * Returns true if @test_ancestor is an ancestor of @test_child.
657  * Otherwise, returns false.
658  */
659 bool fwnode_is_ancestor_of(struct fwnode_handle *test_ancestor,
660 				  struct fwnode_handle *test_child)
661 {
662 	if (!test_ancestor)
663 		return false;
664 
665 	fwnode_handle_get(test_child);
666 	while (test_child) {
667 		if (test_child == test_ancestor) {
668 			fwnode_handle_put(test_child);
669 			return true;
670 		}
671 		test_child = fwnode_get_next_parent(test_child);
672 	}
673 	return false;
674 }
675 
676 /**
677  * fwnode_get_next_child_node - Return the next 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_child_node(const struct fwnode_handle *fwnode,
683 			   struct fwnode_handle *child)
684 {
685 	return fwnode_call_ptr_op(fwnode, get_next_child_node, child);
686 }
687 EXPORT_SYMBOL_GPL(fwnode_get_next_child_node);
688 
689 /**
690  * fwnode_get_next_available_child_node - Return the next
691  * available child node handle for a node
692  * @fwnode: Firmware node to find the next child node for.
693  * @child: Handle to one of the node's child nodes or a %NULL handle.
694  */
695 struct fwnode_handle *
696 fwnode_get_next_available_child_node(const struct fwnode_handle *fwnode,
697 				     struct fwnode_handle *child)
698 {
699 	struct fwnode_handle *next_child = child;
700 
701 	if (!fwnode)
702 		return NULL;
703 
704 	do {
705 		next_child = fwnode_get_next_child_node(fwnode, next_child);
706 		if (!next_child)
707 			return NULL;
708 	} while (!fwnode_device_is_available(next_child));
709 
710 	return next_child;
711 }
712 EXPORT_SYMBOL_GPL(fwnode_get_next_available_child_node);
713 
714 /**
715  * device_get_next_child_node - Return the next child node handle for a device
716  * @dev: Device to find the next child node for.
717  * @child: Handle to one of the device's child nodes or a null handle.
718  */
719 struct fwnode_handle *device_get_next_child_node(struct device *dev,
720 						 struct fwnode_handle *child)
721 {
722 	const struct fwnode_handle *fwnode = dev_fwnode(dev);
723 	struct fwnode_handle *next;
724 
725 	/* Try to find a child in primary fwnode */
726 	next = fwnode_get_next_child_node(fwnode, child);
727 	if (next)
728 		return next;
729 
730 	/* When no more children in primary, continue with secondary */
731 	if (fwnode && !IS_ERR_OR_NULL(fwnode->secondary))
732 		next = fwnode_get_next_child_node(fwnode->secondary, child);
733 
734 	return next;
735 }
736 EXPORT_SYMBOL_GPL(device_get_next_child_node);
737 
738 /**
739  * fwnode_get_named_child_node - Return first matching named child node handle
740  * @fwnode: Firmware node to find the named child node for.
741  * @childname: String to match child node name against.
742  */
743 struct fwnode_handle *
744 fwnode_get_named_child_node(const struct fwnode_handle *fwnode,
745 			    const char *childname)
746 {
747 	return fwnode_call_ptr_op(fwnode, get_named_child_node, childname);
748 }
749 EXPORT_SYMBOL_GPL(fwnode_get_named_child_node);
750 
751 /**
752  * device_get_named_child_node - Return first matching named child node handle
753  * @dev: Device to find the named child node for.
754  * @childname: String to match child node name against.
755  */
756 struct fwnode_handle *device_get_named_child_node(struct device *dev,
757 						  const char *childname)
758 {
759 	return fwnode_get_named_child_node(dev_fwnode(dev), childname);
760 }
761 EXPORT_SYMBOL_GPL(device_get_named_child_node);
762 
763 /**
764  * fwnode_handle_get - Obtain a reference to a device node
765  * @fwnode: Pointer to the device node to obtain the reference to.
766  *
767  * Returns the fwnode handle.
768  */
769 struct fwnode_handle *fwnode_handle_get(struct fwnode_handle *fwnode)
770 {
771 	if (!fwnode_has_op(fwnode, get))
772 		return fwnode;
773 
774 	return fwnode_call_ptr_op(fwnode, get);
775 }
776 EXPORT_SYMBOL_GPL(fwnode_handle_get);
777 
778 /**
779  * fwnode_handle_put - Drop reference to a device node
780  * @fwnode: Pointer to the device node to drop the reference to.
781  *
782  * This has to be used when terminating device_for_each_child_node() iteration
783  * with break or return to prevent stale device node references from being left
784  * behind.
785  */
786 void fwnode_handle_put(struct fwnode_handle *fwnode)
787 {
788 	fwnode_call_void_op(fwnode, put);
789 }
790 EXPORT_SYMBOL_GPL(fwnode_handle_put);
791 
792 /**
793  * fwnode_device_is_available - check if a device is available for use
794  * @fwnode: Pointer to the fwnode of the device.
795  *
796  * For fwnode node types that don't implement the .device_is_available()
797  * operation, this function returns true.
798  */
799 bool fwnode_device_is_available(const struct fwnode_handle *fwnode)
800 {
801 	if (!fwnode_has_op(fwnode, device_is_available))
802 		return true;
803 
804 	return fwnode_call_bool_op(fwnode, device_is_available);
805 }
806 EXPORT_SYMBOL_GPL(fwnode_device_is_available);
807 
808 /**
809  * device_get_child_node_count - return the number of child nodes for device
810  * @dev: Device to cound the child nodes for
811  */
812 unsigned int device_get_child_node_count(struct device *dev)
813 {
814 	struct fwnode_handle *child;
815 	unsigned int count = 0;
816 
817 	device_for_each_child_node(dev, child)
818 		count++;
819 
820 	return count;
821 }
822 EXPORT_SYMBOL_GPL(device_get_child_node_count);
823 
824 bool device_dma_supported(struct device *dev)
825 {
826 	const struct fwnode_handle *fwnode = dev_fwnode(dev);
827 
828 	/* For DT, this is always supported.
829 	 * For ACPI, this depends on CCA, which
830 	 * is determined by the acpi_dma_supported().
831 	 */
832 	if (is_of_node(fwnode))
833 		return true;
834 
835 	return acpi_dma_supported(to_acpi_device_node(fwnode));
836 }
837 EXPORT_SYMBOL_GPL(device_dma_supported);
838 
839 enum dev_dma_attr device_get_dma_attr(struct device *dev)
840 {
841 	const struct fwnode_handle *fwnode = dev_fwnode(dev);
842 	enum dev_dma_attr attr = DEV_DMA_NOT_SUPPORTED;
843 
844 	if (is_of_node(fwnode)) {
845 		if (of_dma_is_coherent(to_of_node(fwnode)))
846 			attr = DEV_DMA_COHERENT;
847 		else
848 			attr = DEV_DMA_NON_COHERENT;
849 	} else
850 		attr = acpi_get_dma_attr(to_acpi_device_node(fwnode));
851 
852 	return attr;
853 }
854 EXPORT_SYMBOL_GPL(device_get_dma_attr);
855 
856 /**
857  * fwnode_get_phy_mode - Get phy mode for given firmware node
858  * @fwnode:	Pointer to the given node
859  *
860  * The function gets phy interface string from property 'phy-mode' or
861  * 'phy-connection-type', and return its index in phy_modes table, or errno in
862  * error case.
863  */
864 int fwnode_get_phy_mode(struct fwnode_handle *fwnode)
865 {
866 	const char *pm;
867 	int err, i;
868 
869 	err = fwnode_property_read_string(fwnode, "phy-mode", &pm);
870 	if (err < 0)
871 		err = fwnode_property_read_string(fwnode,
872 						  "phy-connection-type", &pm);
873 	if (err < 0)
874 		return err;
875 
876 	for (i = 0; i < PHY_INTERFACE_MODE_MAX; i++)
877 		if (!strcasecmp(pm, phy_modes(i)))
878 			return i;
879 
880 	return -ENODEV;
881 }
882 EXPORT_SYMBOL_GPL(fwnode_get_phy_mode);
883 
884 /**
885  * device_get_phy_mode - Get phy mode for given device
886  * @dev:	Pointer to the given device
887  *
888  * The function gets phy interface string from property 'phy-mode' or
889  * 'phy-connection-type', and return its index in phy_modes table, or errno in
890  * error case.
891  */
892 int device_get_phy_mode(struct device *dev)
893 {
894 	return fwnode_get_phy_mode(dev_fwnode(dev));
895 }
896 EXPORT_SYMBOL_GPL(device_get_phy_mode);
897 
898 /**
899  * fwnode_irq_get - Get IRQ directly from a fwnode
900  * @fwnode:	Pointer to the firmware node
901  * @index:	Zero-based index of the IRQ
902  *
903  * Returns Linux IRQ number on success. Other values are determined
904  * accordingly to acpi_/of_ irq_get() operation.
905  */
906 int fwnode_irq_get(const struct fwnode_handle *fwnode, unsigned int index)
907 {
908 	struct resource res;
909 	int ret;
910 
911 	if (is_of_node(fwnode))
912 		return of_irq_get(to_of_node(fwnode), index);
913 
914 	ret = acpi_irq_get(ACPI_HANDLE_FWNODE(fwnode), index, &res);
915 	if (ret)
916 		return ret;
917 
918 	return res.start;
919 }
920 EXPORT_SYMBOL(fwnode_irq_get);
921 
922 /**
923  * fwnode_iomap - Maps the memory mapped IO for a given fwnode
924  * @fwnode:	Pointer to the firmware node
925  * @index:	Index of the IO range
926  *
927  * Returns a pointer to the mapped memory.
928  */
929 void __iomem *fwnode_iomap(struct fwnode_handle *fwnode, int index)
930 {
931 	if (IS_ENABLED(CONFIG_OF_ADDRESS) && is_of_node(fwnode))
932 		return of_iomap(to_of_node(fwnode), index);
933 
934 	return NULL;
935 }
936 EXPORT_SYMBOL(fwnode_iomap);
937 
938 /**
939  * fwnode_irq_get_byname - Get IRQ from a fwnode using its name
940  * @fwnode:	Pointer to the firmware node
941  * @name:	IRQ name
942  *
943  * Description:
944  * Find a match to the string @name in the 'interrupt-names' string array
945  * in _DSD for ACPI, or of_node for Device Tree. Then get the Linux IRQ
946  * number of the IRQ resource corresponding to the index of the matched
947  * string.
948  *
949  * Return:
950  * Linux IRQ number on success, or negative errno otherwise.
951  */
952 int fwnode_irq_get_byname(const struct fwnode_handle *fwnode, const char *name)
953 {
954 	int index;
955 
956 	if (!name)
957 		return -EINVAL;
958 
959 	index = fwnode_property_match_string(fwnode, "interrupt-names",  name);
960 	if (index < 0)
961 		return index;
962 
963 	return fwnode_irq_get(fwnode, index);
964 }
965 EXPORT_SYMBOL(fwnode_irq_get_byname);
966 
967 /**
968  * fwnode_graph_get_next_endpoint - Get next endpoint firmware node
969  * @fwnode: Pointer to the parent firmware node
970  * @prev: Previous endpoint node or %NULL to get the first
971  *
972  * Returns an endpoint firmware node pointer or %NULL if no more endpoints
973  * are available.
974  */
975 struct fwnode_handle *
976 fwnode_graph_get_next_endpoint(const struct fwnode_handle *fwnode,
977 			       struct fwnode_handle *prev)
978 {
979 	const struct fwnode_handle *parent;
980 	struct fwnode_handle *ep;
981 
982 	/*
983 	 * If this function is in a loop and the previous iteration returned
984 	 * an endpoint from fwnode->secondary, then we need to use the secondary
985 	 * as parent rather than @fwnode.
986 	 */
987 	if (prev)
988 		parent = fwnode_graph_get_port_parent(prev);
989 	else
990 		parent = fwnode;
991 
992 	ep = fwnode_call_ptr_op(parent, graph_get_next_endpoint, prev);
993 
994 	if (IS_ERR_OR_NULL(ep) &&
995 	    !IS_ERR_OR_NULL(parent) && !IS_ERR_OR_NULL(parent->secondary))
996 		ep = fwnode_graph_get_next_endpoint(parent->secondary, NULL);
997 
998 	return ep;
999 }
1000 EXPORT_SYMBOL_GPL(fwnode_graph_get_next_endpoint);
1001 
1002 /**
1003  * fwnode_graph_get_port_parent - Return the device fwnode of a port endpoint
1004  * @endpoint: Endpoint firmware node of the port
1005  *
1006  * Return: the firmware node of the device the @endpoint belongs to.
1007  */
1008 struct fwnode_handle *
1009 fwnode_graph_get_port_parent(const struct fwnode_handle *endpoint)
1010 {
1011 	struct fwnode_handle *port, *parent;
1012 
1013 	port = fwnode_get_parent(endpoint);
1014 	parent = fwnode_call_ptr_op(port, graph_get_port_parent);
1015 
1016 	fwnode_handle_put(port);
1017 
1018 	return parent;
1019 }
1020 EXPORT_SYMBOL_GPL(fwnode_graph_get_port_parent);
1021 
1022 /**
1023  * fwnode_graph_get_remote_port_parent - Return fwnode of a remote device
1024  * @fwnode: Endpoint firmware node pointing to the remote endpoint
1025  *
1026  * Extracts firmware node of a remote device the @fwnode points to.
1027  */
1028 struct fwnode_handle *
1029 fwnode_graph_get_remote_port_parent(const struct fwnode_handle *fwnode)
1030 {
1031 	struct fwnode_handle *endpoint, *parent;
1032 
1033 	endpoint = fwnode_graph_get_remote_endpoint(fwnode);
1034 	parent = fwnode_graph_get_port_parent(endpoint);
1035 
1036 	fwnode_handle_put(endpoint);
1037 
1038 	return parent;
1039 }
1040 EXPORT_SYMBOL_GPL(fwnode_graph_get_remote_port_parent);
1041 
1042 /**
1043  * fwnode_graph_get_remote_port - Return fwnode of a remote port
1044  * @fwnode: Endpoint firmware node pointing to the remote endpoint
1045  *
1046  * Extracts firmware node of a remote port the @fwnode points to.
1047  */
1048 struct fwnode_handle *
1049 fwnode_graph_get_remote_port(const struct fwnode_handle *fwnode)
1050 {
1051 	return fwnode_get_next_parent(fwnode_graph_get_remote_endpoint(fwnode));
1052 }
1053 EXPORT_SYMBOL_GPL(fwnode_graph_get_remote_port);
1054 
1055 /**
1056  * fwnode_graph_get_remote_endpoint - Return fwnode of a remote endpoint
1057  * @fwnode: Endpoint firmware node pointing to the remote endpoint
1058  *
1059  * Extracts firmware node of a remote endpoint the @fwnode points to.
1060  */
1061 struct fwnode_handle *
1062 fwnode_graph_get_remote_endpoint(const struct fwnode_handle *fwnode)
1063 {
1064 	return fwnode_call_ptr_op(fwnode, graph_get_remote_endpoint);
1065 }
1066 EXPORT_SYMBOL_GPL(fwnode_graph_get_remote_endpoint);
1067 
1068 static bool fwnode_graph_remote_available(struct fwnode_handle *ep)
1069 {
1070 	struct fwnode_handle *dev_node;
1071 	bool available;
1072 
1073 	dev_node = fwnode_graph_get_remote_port_parent(ep);
1074 	available = fwnode_device_is_available(dev_node);
1075 	fwnode_handle_put(dev_node);
1076 
1077 	return available;
1078 }
1079 
1080 /**
1081  * fwnode_graph_get_endpoint_by_id - get endpoint by port and endpoint numbers
1082  * @fwnode: parent fwnode_handle containing the graph
1083  * @port: identifier of the port node
1084  * @endpoint: identifier of the endpoint node under the port node
1085  * @flags: fwnode lookup flags
1086  *
1087  * Return the fwnode handle of the local endpoint corresponding the port and
1088  * endpoint IDs or NULL if not found.
1089  *
1090  * If FWNODE_GRAPH_ENDPOINT_NEXT is passed in @flags and the specified endpoint
1091  * has not been found, look for the closest endpoint ID greater than the
1092  * specified one and return the endpoint that corresponds to it, if present.
1093  *
1094  * Does not return endpoints that belong to disabled devices or endpoints that
1095  * are unconnected, unless FWNODE_GRAPH_DEVICE_DISABLED is passed in @flags.
1096  *
1097  * The returned endpoint needs to be released by calling fwnode_handle_put() on
1098  * it when it is not needed any more.
1099  */
1100 struct fwnode_handle *
1101 fwnode_graph_get_endpoint_by_id(const struct fwnode_handle *fwnode,
1102 				u32 port, u32 endpoint, unsigned long flags)
1103 {
1104 	struct fwnode_handle *ep, *best_ep = NULL;
1105 	unsigned int best_ep_id = 0;
1106 	bool endpoint_next = flags & FWNODE_GRAPH_ENDPOINT_NEXT;
1107 	bool enabled_only = !(flags & FWNODE_GRAPH_DEVICE_DISABLED);
1108 
1109 	fwnode_graph_for_each_endpoint(fwnode, ep) {
1110 		struct fwnode_endpoint fwnode_ep = { 0 };
1111 		int ret;
1112 
1113 		if (enabled_only && !fwnode_graph_remote_available(ep))
1114 			continue;
1115 
1116 		ret = fwnode_graph_parse_endpoint(ep, &fwnode_ep);
1117 		if (ret < 0)
1118 			continue;
1119 
1120 		if (fwnode_ep.port != port)
1121 			continue;
1122 
1123 		if (fwnode_ep.id == endpoint)
1124 			return ep;
1125 
1126 		if (!endpoint_next)
1127 			continue;
1128 
1129 		/*
1130 		 * If the endpoint that has just been found is not the first
1131 		 * matching one and the ID of the one found previously is closer
1132 		 * to the requested endpoint ID, skip it.
1133 		 */
1134 		if (fwnode_ep.id < endpoint ||
1135 		    (best_ep && best_ep_id < fwnode_ep.id))
1136 			continue;
1137 
1138 		fwnode_handle_put(best_ep);
1139 		best_ep = fwnode_handle_get(ep);
1140 		best_ep_id = fwnode_ep.id;
1141 	}
1142 
1143 	return best_ep;
1144 }
1145 EXPORT_SYMBOL_GPL(fwnode_graph_get_endpoint_by_id);
1146 
1147 /**
1148  * fwnode_graph_get_endpoint_count - Count endpoints on a device node
1149  * @fwnode: The node related to a device
1150  * @flags: fwnode lookup flags
1151  * Count endpoints in a device node.
1152  *
1153  * If FWNODE_GRAPH_DEVICE_DISABLED flag is specified, also unconnected endpoints
1154  * and endpoints connected to disabled devices are counted.
1155  */
1156 unsigned int fwnode_graph_get_endpoint_count(struct fwnode_handle *fwnode,
1157 					     unsigned long flags)
1158 {
1159 	struct fwnode_handle *ep;
1160 	unsigned int count = 0;
1161 
1162 	fwnode_graph_for_each_endpoint(fwnode, ep) {
1163 		if (flags & FWNODE_GRAPH_DEVICE_DISABLED ||
1164 		    fwnode_graph_remote_available(ep))
1165 			count++;
1166 	}
1167 
1168 	return count;
1169 }
1170 EXPORT_SYMBOL_GPL(fwnode_graph_get_endpoint_count);
1171 
1172 /**
1173  * fwnode_graph_parse_endpoint - parse common endpoint node properties
1174  * @fwnode: pointer to endpoint fwnode_handle
1175  * @endpoint: pointer to the fwnode endpoint data structure
1176  *
1177  * Parse @fwnode representing a graph endpoint node and store the
1178  * information in @endpoint. The caller must hold a reference to
1179  * @fwnode.
1180  */
1181 int fwnode_graph_parse_endpoint(const struct fwnode_handle *fwnode,
1182 				struct fwnode_endpoint *endpoint)
1183 {
1184 	memset(endpoint, 0, sizeof(*endpoint));
1185 
1186 	return fwnode_call_int_op(fwnode, graph_parse_endpoint, endpoint);
1187 }
1188 EXPORT_SYMBOL(fwnode_graph_parse_endpoint);
1189 
1190 const void *device_get_match_data(struct device *dev)
1191 {
1192 	return fwnode_call_ptr_op(dev_fwnode(dev), device_get_match_data, dev);
1193 }
1194 EXPORT_SYMBOL_GPL(device_get_match_data);
1195 
1196 static void *
1197 fwnode_graph_devcon_match(struct fwnode_handle *fwnode, const char *con_id,
1198 			  void *data, devcon_match_fn_t match)
1199 {
1200 	struct fwnode_handle *node;
1201 	struct fwnode_handle *ep;
1202 	void *ret;
1203 
1204 	fwnode_graph_for_each_endpoint(fwnode, ep) {
1205 		node = fwnode_graph_get_remote_port_parent(ep);
1206 		if (!fwnode_device_is_available(node)) {
1207 			fwnode_handle_put(node);
1208 			continue;
1209 		}
1210 
1211 		ret = match(node, con_id, data);
1212 		fwnode_handle_put(node);
1213 		if (ret) {
1214 			fwnode_handle_put(ep);
1215 			return ret;
1216 		}
1217 	}
1218 	return NULL;
1219 }
1220 
1221 static void *
1222 fwnode_devcon_match(struct fwnode_handle *fwnode, const char *con_id,
1223 		    void *data, devcon_match_fn_t match)
1224 {
1225 	struct fwnode_handle *node;
1226 	void *ret;
1227 	int i;
1228 
1229 	for (i = 0; ; i++) {
1230 		node = fwnode_find_reference(fwnode, con_id, i);
1231 		if (IS_ERR(node))
1232 			break;
1233 
1234 		ret = match(node, NULL, data);
1235 		fwnode_handle_put(node);
1236 		if (ret)
1237 			return ret;
1238 	}
1239 
1240 	return NULL;
1241 }
1242 
1243 /**
1244  * fwnode_connection_find_match - Find connection from a device node
1245  * @fwnode: Device node with the connection
1246  * @con_id: Identifier for the connection
1247  * @data: Data for the match function
1248  * @match: Function to check and convert the connection description
1249  *
1250  * Find a connection with unique identifier @con_id between @fwnode and another
1251  * device node. @match will be used to convert the connection description to
1252  * data the caller is expecting to be returned.
1253  */
1254 void *fwnode_connection_find_match(struct fwnode_handle *fwnode,
1255 				   const char *con_id, void *data,
1256 				   devcon_match_fn_t match)
1257 {
1258 	void *ret;
1259 
1260 	if (!fwnode || !match)
1261 		return NULL;
1262 
1263 	ret = fwnode_graph_devcon_match(fwnode, con_id, data, match);
1264 	if (ret)
1265 		return ret;
1266 
1267 	return fwnode_devcon_match(fwnode, con_id, data, match);
1268 }
1269 EXPORT_SYMBOL_GPL(fwnode_connection_find_match);
1270