xref: /linux/drivers/base/property.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 /*
2  * property.c - Unified device property interface.
3  *
4  * Copyright (C) 2014, Intel Corporation
5  * Authors: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
6  *          Mika Westerberg <mika.westerberg@linux.intel.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  */
12 
13 #include <linux/acpi.h>
14 #include <linux/export.h>
15 #include <linux/kernel.h>
16 #include <linux/of.h>
17 #include <linux/of_address.h>
18 #include <linux/property.h>
19 #include <linux/etherdevice.h>
20 #include <linux/phy.h>
21 
22 /**
23  * device_add_property_set - Add a collection of properties to a device object.
24  * @dev: Device to add properties to.
25  * @pset: Collection of properties to add.
26  *
27  * Associate a collection of device properties represented by @pset with @dev
28  * as its secondary firmware node.
29  */
30 void device_add_property_set(struct device *dev, struct property_set *pset)
31 {
32 	if (!pset)
33 		return;
34 
35 	pset->fwnode.type = FWNODE_PDATA;
36 	set_secondary_fwnode(dev, &pset->fwnode);
37 }
38 EXPORT_SYMBOL_GPL(device_add_property_set);
39 
40 static inline bool is_pset(struct fwnode_handle *fwnode)
41 {
42 	return fwnode && fwnode->type == FWNODE_PDATA;
43 }
44 
45 static inline struct property_set *to_pset(struct fwnode_handle *fwnode)
46 {
47 	return is_pset(fwnode) ?
48 		container_of(fwnode, struct property_set, fwnode) : NULL;
49 }
50 
51 static struct property_entry *pset_prop_get(struct property_set *pset,
52 					    const char *name)
53 {
54 	struct property_entry *prop;
55 
56 	if (!pset || !pset->properties)
57 		return NULL;
58 
59 	for (prop = pset->properties; prop->name; prop++)
60 		if (!strcmp(name, prop->name))
61 			return prop;
62 
63 	return NULL;
64 }
65 
66 static int pset_prop_read_array(struct property_set *pset, const char *name,
67 				enum dev_prop_type type, void *val, size_t nval)
68 {
69 	struct property_entry *prop;
70 	unsigned int item_size;
71 
72 	prop = pset_prop_get(pset, name);
73 	if (!prop)
74 		return -ENODATA;
75 
76 	if (prop->type != type)
77 		return -EPROTO;
78 
79 	if (!val)
80 		return prop->nval;
81 
82 	if (prop->nval < nval)
83 		return -EOVERFLOW;
84 
85 	switch (type) {
86 	case DEV_PROP_U8:
87 		item_size = sizeof(u8);
88 		break;
89 	case DEV_PROP_U16:
90 		item_size = sizeof(u16);
91 		break;
92 	case DEV_PROP_U32:
93 		item_size = sizeof(u32);
94 		break;
95 	case DEV_PROP_U64:
96 		item_size = sizeof(u64);
97 		break;
98 	case DEV_PROP_STRING:
99 		item_size = sizeof(const char *);
100 		break;
101 	default:
102 		return -EINVAL;
103 	}
104 	memcpy(val, prop->value.raw_data, nval * item_size);
105 	return 0;
106 }
107 
108 static inline struct fwnode_handle *dev_fwnode(struct device *dev)
109 {
110 	return IS_ENABLED(CONFIG_OF) && dev->of_node ?
111 		&dev->of_node->fwnode : dev->fwnode;
112 }
113 
114 /**
115  * device_property_present - check if a property of a device is present
116  * @dev: Device whose property is being checked
117  * @propname: Name of the property
118  *
119  * Check if property @propname is present in the device firmware description.
120  */
121 bool device_property_present(struct device *dev, const char *propname)
122 {
123 	return fwnode_property_present(dev_fwnode(dev), propname);
124 }
125 EXPORT_SYMBOL_GPL(device_property_present);
126 
127 /**
128  * fwnode_property_present - check if a property of a firmware node is present
129  * @fwnode: Firmware node whose property to check
130  * @propname: Name of the property
131  */
132 bool fwnode_property_present(struct fwnode_handle *fwnode, const char *propname)
133 {
134 	if (is_of_node(fwnode))
135 		return of_property_read_bool(to_of_node(fwnode), propname);
136 	else if (is_acpi_node(fwnode))
137 		return !acpi_dev_prop_get(to_acpi_node(fwnode), propname, NULL);
138 
139 	return !!pset_prop_get(to_pset(fwnode), propname);
140 }
141 EXPORT_SYMBOL_GPL(fwnode_property_present);
142 
143 /**
144  * device_property_read_u8_array - return a u8 array property of a device
145  * @dev: Device to get the property of
146  * @propname: Name of the property
147  * @val: The values are stored here or %NULL to return the number of values
148  * @nval: Size of the @val array
149  *
150  * Function reads an array of u8 properties with @propname from the device
151  * firmware description and stores them to @val if found.
152  *
153  * Return: number of values if @val was %NULL,
154  *         %0 if the property was found (success),
155  *	   %-EINVAL if given arguments are not valid,
156  *	   %-ENODATA if the property does not have a value,
157  *	   %-EPROTO if the property is not an array of numbers,
158  *	   %-EOVERFLOW if the size of the property is not as expected.
159  *	   %-ENXIO if no suitable firmware interface is present.
160  */
161 int device_property_read_u8_array(struct device *dev, const char *propname,
162 				  u8 *val, size_t nval)
163 {
164 	return fwnode_property_read_u8_array(dev_fwnode(dev), propname, val, nval);
165 }
166 EXPORT_SYMBOL_GPL(device_property_read_u8_array);
167 
168 /**
169  * device_property_read_u16_array - return a u16 array property of a device
170  * @dev: Device to get the property of
171  * @propname: Name of the property
172  * @val: The values are stored here or %NULL to return the number of values
173  * @nval: Size of the @val array
174  *
175  * Function reads an array of u16 properties with @propname from the device
176  * firmware description and stores them to @val if found.
177  *
178  * Return: number of values if @val was %NULL,
179  *         %0 if the property was found (success),
180  *	   %-EINVAL if given arguments are not valid,
181  *	   %-ENODATA if the property does not have a value,
182  *	   %-EPROTO if the property is not an array of numbers,
183  *	   %-EOVERFLOW if the size of the property is not as expected.
184  *	   %-ENXIO if no suitable firmware interface is present.
185  */
186 int device_property_read_u16_array(struct device *dev, const char *propname,
187 				   u16 *val, size_t nval)
188 {
189 	return fwnode_property_read_u16_array(dev_fwnode(dev), propname, val, nval);
190 }
191 EXPORT_SYMBOL_GPL(device_property_read_u16_array);
192 
193 /**
194  * device_property_read_u32_array - return a u32 array property of a device
195  * @dev: Device to get the property of
196  * @propname: Name of the property
197  * @val: The values are stored here or %NULL to return the number of values
198  * @nval: Size of the @val array
199  *
200  * Function reads an array of u32 properties with @propname from the device
201  * firmware description and stores them to @val if found.
202  *
203  * Return: number of values if @val was %NULL,
204  *         %0 if the property was found (success),
205  *	   %-EINVAL if given arguments are not valid,
206  *	   %-ENODATA if the property does not have a value,
207  *	   %-EPROTO if the property is not an array of numbers,
208  *	   %-EOVERFLOW if the size of the property is not as expected.
209  *	   %-ENXIO if no suitable firmware interface is present.
210  */
211 int device_property_read_u32_array(struct device *dev, const char *propname,
212 				   u32 *val, size_t nval)
213 {
214 	return fwnode_property_read_u32_array(dev_fwnode(dev), propname, val, nval);
215 }
216 EXPORT_SYMBOL_GPL(device_property_read_u32_array);
217 
218 /**
219  * device_property_read_u64_array - return a u64 array property of a device
220  * @dev: Device to get the property of
221  * @propname: Name of the property
222  * @val: The values are stored here or %NULL to return the number of values
223  * @nval: Size of the @val array
224  *
225  * Function reads an array of u64 properties with @propname from the device
226  * firmware description and stores them to @val if found.
227  *
228  * Return: number of values if @val was %NULL,
229  *         %0 if the property was found (success),
230  *	   %-EINVAL if given arguments are not valid,
231  *	   %-ENODATA if the property does not have a value,
232  *	   %-EPROTO if the property is not an array of numbers,
233  *	   %-EOVERFLOW if the size of the property is not as expected.
234  *	   %-ENXIO if no suitable firmware interface is present.
235  */
236 int device_property_read_u64_array(struct device *dev, const char *propname,
237 				   u64 *val, size_t nval)
238 {
239 	return fwnode_property_read_u64_array(dev_fwnode(dev), propname, val, nval);
240 }
241 EXPORT_SYMBOL_GPL(device_property_read_u64_array);
242 
243 /**
244  * device_property_read_string_array - return a string array property of device
245  * @dev: Device to get the property of
246  * @propname: Name of the property
247  * @val: The values are stored here or %NULL to return the number of values
248  * @nval: Size of the @val array
249  *
250  * Function reads an array of string properties with @propname from the device
251  * firmware description and stores them to @val if found.
252  *
253  * Return: number of values if @val was %NULL,
254  *         %0 if the property was found (success),
255  *	   %-EINVAL if given arguments are not valid,
256  *	   %-ENODATA if the property does not have a value,
257  *	   %-EPROTO or %-EILSEQ if the property is not an array of strings,
258  *	   %-EOVERFLOW if the size of the property is not as expected.
259  *	   %-ENXIO if no suitable firmware interface is present.
260  */
261 int device_property_read_string_array(struct device *dev, const char *propname,
262 				      const char **val, size_t nval)
263 {
264 	return fwnode_property_read_string_array(dev_fwnode(dev), propname, val, nval);
265 }
266 EXPORT_SYMBOL_GPL(device_property_read_string_array);
267 
268 /**
269  * device_property_read_string - return a string property of a device
270  * @dev: Device to get the property of
271  * @propname: Name of the property
272  * @val: The value is stored here
273  *
274  * Function reads property @propname from the device firmware description and
275  * stores the value into @val if found. The value is checked to be a string.
276  *
277  * Return: %0 if the property was found (success),
278  *	   %-EINVAL if given arguments are not valid,
279  *	   %-ENODATA if the property does not have a value,
280  *	   %-EPROTO or %-EILSEQ if the property type is not a string.
281  *	   %-ENXIO if no suitable firmware interface is present.
282  */
283 int device_property_read_string(struct device *dev, const char *propname,
284 				const char **val)
285 {
286 	return fwnode_property_read_string(dev_fwnode(dev), propname, val);
287 }
288 EXPORT_SYMBOL_GPL(device_property_read_string);
289 
290 #define OF_DEV_PROP_READ_ARRAY(node, propname, type, val, nval) \
291 	(val) ? of_property_read_##type##_array((node), (propname), (val), (nval)) \
292 	      : of_property_count_elems_of_size((node), (propname), sizeof(type))
293 
294 #define FWNODE_PROP_READ_ARRAY(_fwnode_, _propname_, _type_, _proptype_, _val_, _nval_) \
295 ({ \
296 	int _ret_; \
297 	if (is_of_node(_fwnode_)) \
298 		_ret_ = OF_DEV_PROP_READ_ARRAY(to_of_node(_fwnode_), _propname_, \
299 					       _type_, _val_, _nval_); \
300 	else if (is_acpi_node(_fwnode_)) \
301 		_ret_ = acpi_dev_prop_read(to_acpi_node(_fwnode_), _propname_, \
302 					   _proptype_, _val_, _nval_); \
303 	else if (is_pset(_fwnode_)) \
304 		_ret_ = pset_prop_read_array(to_pset(_fwnode_), _propname_, \
305 					     _proptype_, _val_, _nval_); \
306 	else \
307 		_ret_ = -ENXIO; \
308 	_ret_; \
309 })
310 
311 /**
312  * fwnode_property_read_u8_array - return a u8 array property of firmware node
313  * @fwnode: Firmware node to get the property of
314  * @propname: Name of the property
315  * @val: The values are stored here or %NULL to return the number of values
316  * @nval: Size of the @val array
317  *
318  * Read an array of u8 properties with @propname from @fwnode and stores them to
319  * @val if found.
320  *
321  * Return: number of values if @val was %NULL,
322  *         %0 if the property was found (success),
323  *	   %-EINVAL if given arguments are not valid,
324  *	   %-ENODATA if the property does not have a value,
325  *	   %-EPROTO if the property is not an array of numbers,
326  *	   %-EOVERFLOW if the size of the property is not as expected,
327  *	   %-ENXIO if no suitable firmware interface is present.
328  */
329 int fwnode_property_read_u8_array(struct fwnode_handle *fwnode,
330 				  const char *propname, u8 *val, size_t nval)
331 {
332 	return FWNODE_PROP_READ_ARRAY(fwnode, propname, u8, DEV_PROP_U8,
333 				      val, nval);
334 }
335 EXPORT_SYMBOL_GPL(fwnode_property_read_u8_array);
336 
337 /**
338  * fwnode_property_read_u16_array - return a u16 array property of firmware node
339  * @fwnode: Firmware node to get the property of
340  * @propname: Name of the property
341  * @val: The values are stored here or %NULL to return the number of values
342  * @nval: Size of the @val array
343  *
344  * Read an array of u16 properties with @propname from @fwnode and store them to
345  * @val if found.
346  *
347  * Return: number of values if @val was %NULL,
348  *         %0 if the property was found (success),
349  *	   %-EINVAL if given arguments are not valid,
350  *	   %-ENODATA if the property does not have a value,
351  *	   %-EPROTO if the property is not an array of numbers,
352  *	   %-EOVERFLOW if the size of the property is not as expected,
353  *	   %-ENXIO if no suitable firmware interface is present.
354  */
355 int fwnode_property_read_u16_array(struct fwnode_handle *fwnode,
356 				   const char *propname, u16 *val, size_t nval)
357 {
358 	return FWNODE_PROP_READ_ARRAY(fwnode, propname, u16, DEV_PROP_U16,
359 				      val, nval);
360 }
361 EXPORT_SYMBOL_GPL(fwnode_property_read_u16_array);
362 
363 /**
364  * fwnode_property_read_u32_array - return a u32 array property of firmware node
365  * @fwnode: Firmware node to get the property of
366  * @propname: Name of the property
367  * @val: The values are stored here or %NULL to return the number of values
368  * @nval: Size of the @val array
369  *
370  * Read an array of u32 properties with @propname from @fwnode store them to
371  * @val if found.
372  *
373  * Return: number of values if @val was %NULL,
374  *         %0 if the property was found (success),
375  *	   %-EINVAL if given arguments are not valid,
376  *	   %-ENODATA if the property does not have a value,
377  *	   %-EPROTO if the property is not an array of numbers,
378  *	   %-EOVERFLOW if the size of the property is not as expected,
379  *	   %-ENXIO if no suitable firmware interface is present.
380  */
381 int fwnode_property_read_u32_array(struct fwnode_handle *fwnode,
382 				   const char *propname, u32 *val, size_t nval)
383 {
384 	return FWNODE_PROP_READ_ARRAY(fwnode, propname, u32, DEV_PROP_U32,
385 				      val, nval);
386 }
387 EXPORT_SYMBOL_GPL(fwnode_property_read_u32_array);
388 
389 /**
390  * fwnode_property_read_u64_array - return a u64 array property firmware node
391  * @fwnode: Firmware node to get the property of
392  * @propname: Name of the property
393  * @val: The values are stored here or %NULL to return the number of values
394  * @nval: Size of the @val array
395  *
396  * Read an array of u64 properties with @propname from @fwnode and store them to
397  * @val if found.
398  *
399  * Return: number of values if @val was %NULL,
400  *         %0 if the property was found (success),
401  *	   %-EINVAL if given arguments are not valid,
402  *	   %-ENODATA if the property does not have a value,
403  *	   %-EPROTO if the property is not an array of numbers,
404  *	   %-EOVERFLOW if the size of the property is not as expected,
405  *	   %-ENXIO if no suitable firmware interface is present.
406  */
407 int fwnode_property_read_u64_array(struct fwnode_handle *fwnode,
408 				   const char *propname, u64 *val, size_t nval)
409 {
410 	return FWNODE_PROP_READ_ARRAY(fwnode, propname, u64, DEV_PROP_U64,
411 				      val, nval);
412 }
413 EXPORT_SYMBOL_GPL(fwnode_property_read_u64_array);
414 
415 /**
416  * fwnode_property_read_string_array - return string array property of a node
417  * @fwnode: Firmware node to get the property of
418  * @propname: Name of the property
419  * @val: The values are stored here or %NULL to return the number of values
420  * @nval: Size of the @val array
421  *
422  * Read an string list property @propname from the given firmware node and store
423  * them to @val if found.
424  *
425  * Return: number of values if @val was %NULL,
426  *         %0 if the property was found (success),
427  *	   %-EINVAL if given arguments are not valid,
428  *	   %-ENODATA if the property does not have a value,
429  *	   %-EPROTO if the property is not an array of strings,
430  *	   %-EOVERFLOW if the size of the property is not as expected,
431  *	   %-ENXIO if no suitable firmware interface is present.
432  */
433 int fwnode_property_read_string_array(struct fwnode_handle *fwnode,
434 				      const char *propname, const char **val,
435 				      size_t nval)
436 {
437 	if (is_of_node(fwnode))
438 		return val ?
439 			of_property_read_string_array(to_of_node(fwnode),
440 						      propname, val, nval) :
441 			of_property_count_strings(to_of_node(fwnode), propname);
442 	else if (is_acpi_node(fwnode))
443 		return acpi_dev_prop_read(to_acpi_node(fwnode), propname,
444 					  DEV_PROP_STRING, val, nval);
445 	else if (is_pset(fwnode))
446 		return pset_prop_read_array(to_pset(fwnode), propname,
447 					    DEV_PROP_STRING, val, nval);
448 	return -ENXIO;
449 }
450 EXPORT_SYMBOL_GPL(fwnode_property_read_string_array);
451 
452 /**
453  * fwnode_property_read_string - return a string property of a firmware node
454  * @fwnode: Firmware node to get the property of
455  * @propname: Name of the property
456  * @val: The value is stored here
457  *
458  * Read property @propname from the given firmware node and store the value into
459  * @val if found.  The value is checked to be a string.
460  *
461  * Return: %0 if the property was found (success),
462  *	   %-EINVAL if given arguments are not valid,
463  *	   %-ENODATA if the property does not have a value,
464  *	   %-EPROTO or %-EILSEQ if the property is not a string,
465  *	   %-ENXIO if no suitable firmware interface is present.
466  */
467 int fwnode_property_read_string(struct fwnode_handle *fwnode,
468 				const char *propname, const char **val)
469 {
470 	if (is_of_node(fwnode))
471 		return of_property_read_string(to_of_node(fwnode), propname, val);
472 	else if (is_acpi_node(fwnode))
473 		return acpi_dev_prop_read(to_acpi_node(fwnode), propname,
474 					  DEV_PROP_STRING, val, 1);
475 
476 	return pset_prop_read_array(to_pset(fwnode), propname,
477 				    DEV_PROP_STRING, val, 1);
478 }
479 EXPORT_SYMBOL_GPL(fwnode_property_read_string);
480 
481 /**
482  * device_get_next_child_node - Return the next child node handle for a device
483  * @dev: Device to find the next child node for.
484  * @child: Handle to one of the device's child nodes or a null handle.
485  */
486 struct fwnode_handle *device_get_next_child_node(struct device *dev,
487 						 struct fwnode_handle *child)
488 {
489 	if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
490 		struct device_node *node;
491 
492 		node = of_get_next_available_child(dev->of_node, to_of_node(child));
493 		if (node)
494 			return &node->fwnode;
495 	} else if (IS_ENABLED(CONFIG_ACPI)) {
496 		struct acpi_device *node;
497 
498 		node = acpi_get_next_child(dev, to_acpi_node(child));
499 		if (node)
500 			return acpi_fwnode_handle(node);
501 	}
502 	return NULL;
503 }
504 EXPORT_SYMBOL_GPL(device_get_next_child_node);
505 
506 /**
507  * fwnode_handle_put - Drop reference to a device node
508  * @fwnode: Pointer to the device node to drop the reference to.
509  *
510  * This has to be used when terminating device_for_each_child_node() iteration
511  * with break or return to prevent stale device node references from being left
512  * behind.
513  */
514 void fwnode_handle_put(struct fwnode_handle *fwnode)
515 {
516 	if (is_of_node(fwnode))
517 		of_node_put(to_of_node(fwnode));
518 }
519 EXPORT_SYMBOL_GPL(fwnode_handle_put);
520 
521 /**
522  * device_get_child_node_count - return the number of child nodes for device
523  * @dev: Device to cound the child nodes for
524  */
525 unsigned int device_get_child_node_count(struct device *dev)
526 {
527 	struct fwnode_handle *child;
528 	unsigned int count = 0;
529 
530 	device_for_each_child_node(dev, child)
531 		count++;
532 
533 	return count;
534 }
535 EXPORT_SYMBOL_GPL(device_get_child_node_count);
536 
537 bool device_dma_is_coherent(struct device *dev)
538 {
539 	bool coherent = false;
540 
541 	if (IS_ENABLED(CONFIG_OF) && dev->of_node)
542 		coherent = of_dma_is_coherent(dev->of_node);
543 	else
544 		acpi_check_dma(ACPI_COMPANION(dev), &coherent);
545 
546 	return coherent;
547 }
548 EXPORT_SYMBOL_GPL(device_dma_is_coherent);
549 
550 /**
551  * device_get_phy_mode - Get phy mode for given device
552  * @dev:	Pointer to the given device
553  *
554  * The function gets phy interface string from property 'phy-mode' or
555  * 'phy-connection-type', and return its index in phy_modes table, or errno in
556  * error case.
557  */
558 int device_get_phy_mode(struct device *dev)
559 {
560 	const char *pm;
561 	int err, i;
562 
563 	err = device_property_read_string(dev, "phy-mode", &pm);
564 	if (err < 0)
565 		err = device_property_read_string(dev,
566 						  "phy-connection-type", &pm);
567 	if (err < 0)
568 		return err;
569 
570 	for (i = 0; i < PHY_INTERFACE_MODE_MAX; i++)
571 		if (!strcasecmp(pm, phy_modes(i)))
572 			return i;
573 
574 	return -ENODEV;
575 }
576 EXPORT_SYMBOL_GPL(device_get_phy_mode);
577 
578 static void *device_get_mac_addr(struct device *dev,
579 				 const char *name, char *addr,
580 				 int alen)
581 {
582 	int ret = device_property_read_u8_array(dev, name, addr, alen);
583 
584 	if (ret == 0 && alen == ETH_ALEN && is_valid_ether_addr(addr))
585 		return addr;
586 	return NULL;
587 }
588 
589 /**
590  * device_get_mac_address - Get the MAC for a given device
591  * @dev:	Pointer to the device
592  * @addr:	Address of buffer to store the MAC in
593  * @alen:	Length of the buffer pointed to by addr, should be ETH_ALEN
594  *
595  * Search the firmware node for the best MAC address to use.  'mac-address' is
596  * checked first, because that is supposed to contain to "most recent" MAC
597  * address. If that isn't set, then 'local-mac-address' is checked next,
598  * because that is the default address.  If that isn't set, then the obsolete
599  * 'address' is checked, just in case we're using an old device tree.
600  *
601  * Note that the 'address' property is supposed to contain a virtual address of
602  * the register set, but some DTS files have redefined that property to be the
603  * MAC address.
604  *
605  * All-zero MAC addresses are rejected, because those could be properties that
606  * exist in the firmware tables, but were not updated by the firmware.  For
607  * example, the DTS could define 'mac-address' and 'local-mac-address', with
608  * zero MAC addresses.  Some older U-Boots only initialized 'local-mac-address'.
609  * In this case, the real MAC is in 'local-mac-address', and 'mac-address'
610  * exists but is all zeros.
611 */
612 void *device_get_mac_address(struct device *dev, char *addr, int alen)
613 {
614 	char *res;
615 
616 	res = device_get_mac_addr(dev, "mac-address", addr, alen);
617 	if (res)
618 		return res;
619 
620 	res = device_get_mac_addr(dev, "local-mac-address", addr, alen);
621 	if (res)
622 		return res;
623 
624 	return device_get_mac_addr(dev, "address", addr, alen);
625 }
626 EXPORT_SYMBOL(device_get_mac_address);
627