xref: /linux/drivers/acpi/property.c (revision daa121128a2d2ac6006159e2c47676e4fcd21eab)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * ACPI device specific properties support.
4  *
5  * Copyright (C) 2014 - 2023, Intel Corporation
6  * All rights reserved.
7  *
8  * Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
9  *          Darren Hart <dvhart@linux.intel.com>
10  *          Rafael J. Wysocki <rafael.j.wysocki@intel.com>
11  *          Sakari Ailus <sakari.ailus@linux.intel.com>
12  */
13 
14 #define pr_fmt(fmt) "ACPI: " fmt
15 
16 #include <linux/acpi.h>
17 #include <linux/device.h>
18 #include <linux/export.h>
19 
20 #include "internal.h"
21 
22 static int acpi_data_get_property_array(const struct acpi_device_data *data,
23 					const char *name,
24 					acpi_object_type type,
25 					const union acpi_object **obj);
26 
27 /*
28  * The GUIDs here are made equivalent to each other in order to avoid extra
29  * complexity in the properties handling code, with the caveat that the
30  * kernel will accept certain combinations of GUID and properties that are
31  * not defined without a warning. For instance if any of the properties
32  * from different GUID appear in a property list of another, it will be
33  * accepted by the kernel. Firmware validation tools should catch these.
34  *
35  * References:
36  *
37  * [1] UEFI DSD Guide.
38  *     https://github.com/UEFI/DSD-Guide/blob/main/src/dsd-guide.adoc
39  */
40 static const guid_t prp_guids[] = {
41 	/* ACPI _DSD device properties GUID [1]: daffd814-6eba-4d8c-8a91-bc9bbf4aa301 */
42 	GUID_INIT(0xdaffd814, 0x6eba, 0x4d8c,
43 		  0x8a, 0x91, 0xbc, 0x9b, 0xbf, 0x4a, 0xa3, 0x01),
44 	/* Hotplug in D3 GUID: 6211e2c0-58a3-4af3-90e1-927a4e0c55a4 */
45 	GUID_INIT(0x6211e2c0, 0x58a3, 0x4af3,
46 		  0x90, 0xe1, 0x92, 0x7a, 0x4e, 0x0c, 0x55, 0xa4),
47 	/* External facing port GUID: efcc06cc-73ac-4bc3-bff0-76143807c389 */
48 	GUID_INIT(0xefcc06cc, 0x73ac, 0x4bc3,
49 		  0xbf, 0xf0, 0x76, 0x14, 0x38, 0x07, 0xc3, 0x89),
50 	/* Thunderbolt GUID for IMR_VALID: c44d002f-69f9-4e7d-a904-a7baabdf43f7 */
51 	GUID_INIT(0xc44d002f, 0x69f9, 0x4e7d,
52 		  0xa9, 0x04, 0xa7, 0xba, 0xab, 0xdf, 0x43, 0xf7),
53 	/* Thunderbolt GUID for WAKE_SUPPORTED: 6c501103-c189-4296-ba72-9bf5a26ebe5d */
54 	GUID_INIT(0x6c501103, 0xc189, 0x4296,
55 		  0xba, 0x72, 0x9b, 0xf5, 0xa2, 0x6e, 0xbe, 0x5d),
56 	/* Storage device needs D3 GUID: 5025030f-842f-4ab4-a561-99a5189762d0 */
57 	GUID_INIT(0x5025030f, 0x842f, 0x4ab4,
58 		  0xa5, 0x61, 0x99, 0xa5, 0x18, 0x97, 0x62, 0xd0),
59 };
60 
61 /* ACPI _DSD data subnodes GUID [1]: dbb8e3e6-5886-4ba6-8795-1319f52a966b */
62 static const guid_t ads_guid =
63 	GUID_INIT(0xdbb8e3e6, 0x5886, 0x4ba6,
64 		  0x87, 0x95, 0x13, 0x19, 0xf5, 0x2a, 0x96, 0x6b);
65 
66 /* ACPI _DSD data buffer GUID [1]: edb12dd0-363d-4085-a3d2-49522ca160c4 */
67 static const guid_t buffer_prop_guid =
68 	GUID_INIT(0xedb12dd0, 0x363d, 0x4085,
69 		  0xa3, 0xd2, 0x49, 0x52, 0x2c, 0xa1, 0x60, 0xc4);
70 
71 static bool acpi_enumerate_nondev_subnodes(acpi_handle scope,
72 					   union acpi_object *desc,
73 					   struct acpi_device_data *data,
74 					   struct fwnode_handle *parent);
75 static bool acpi_extract_properties(acpi_handle handle,
76 				    union acpi_object *desc,
77 				    struct acpi_device_data *data);
78 
79 static bool acpi_nondev_subnode_extract(union acpi_object *desc,
80 					acpi_handle handle,
81 					const union acpi_object *link,
82 					struct list_head *list,
83 					struct fwnode_handle *parent)
84 {
85 	struct acpi_data_node *dn;
86 	bool result;
87 
88 	if (acpi_graph_ignore_port(handle))
89 		return false;
90 
91 	dn = kzalloc(sizeof(*dn), GFP_KERNEL);
92 	if (!dn)
93 		return false;
94 
95 	dn->name = link->package.elements[0].string.pointer;
96 	fwnode_init(&dn->fwnode, &acpi_data_fwnode_ops);
97 	dn->parent = parent;
98 	INIT_LIST_HEAD(&dn->data.properties);
99 	INIT_LIST_HEAD(&dn->data.subnodes);
100 
101 	result = acpi_extract_properties(handle, desc, &dn->data);
102 
103 	if (handle) {
104 		acpi_handle scope;
105 		acpi_status status;
106 
107 		/*
108 		 * The scope for the subnode object lookup is the one of the
109 		 * namespace node (device) containing the object that has
110 		 * returned the package.  That is, it's the scope of that
111 		 * object's parent.
112 		 */
113 		status = acpi_get_parent(handle, &scope);
114 		if (ACPI_SUCCESS(status)
115 		    && acpi_enumerate_nondev_subnodes(scope, desc, &dn->data,
116 						      &dn->fwnode))
117 			result = true;
118 	} else if (acpi_enumerate_nondev_subnodes(NULL, desc, &dn->data,
119 						  &dn->fwnode)) {
120 		result = true;
121 	}
122 
123 	if (result) {
124 		dn->handle = handle;
125 		dn->data.pointer = desc;
126 		list_add_tail(&dn->sibling, list);
127 		return true;
128 	}
129 
130 	kfree(dn);
131 	acpi_handle_debug(handle, "Invalid properties/subnodes data, skipping\n");
132 	return false;
133 }
134 
135 static bool acpi_nondev_subnode_data_ok(acpi_handle handle,
136 					const union acpi_object *link,
137 					struct list_head *list,
138 					struct fwnode_handle *parent)
139 {
140 	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
141 	acpi_status status;
142 
143 	status = acpi_evaluate_object_typed(handle, NULL, NULL, &buf,
144 					    ACPI_TYPE_PACKAGE);
145 	if (ACPI_FAILURE(status))
146 		return false;
147 
148 	if (acpi_nondev_subnode_extract(buf.pointer, handle, link, list,
149 					parent))
150 		return true;
151 
152 	ACPI_FREE(buf.pointer);
153 	return false;
154 }
155 
156 static bool acpi_nondev_subnode_ok(acpi_handle scope,
157 				   const union acpi_object *link,
158 				   struct list_head *list,
159 				   struct fwnode_handle *parent)
160 {
161 	acpi_handle handle;
162 	acpi_status status;
163 
164 	if (!scope)
165 		return false;
166 
167 	status = acpi_get_handle(scope, link->package.elements[1].string.pointer,
168 				 &handle);
169 	if (ACPI_FAILURE(status))
170 		return false;
171 
172 	return acpi_nondev_subnode_data_ok(handle, link, list, parent);
173 }
174 
175 static bool acpi_add_nondev_subnodes(acpi_handle scope,
176 				     union acpi_object *links,
177 				     struct list_head *list,
178 				     struct fwnode_handle *parent)
179 {
180 	bool ret = false;
181 	int i;
182 
183 	for (i = 0; i < links->package.count; i++) {
184 		union acpi_object *link, *desc;
185 		acpi_handle handle;
186 		bool result;
187 
188 		link = &links->package.elements[i];
189 		/* Only two elements allowed. */
190 		if (link->package.count != 2)
191 			continue;
192 
193 		/* The first one must be a string. */
194 		if (link->package.elements[0].type != ACPI_TYPE_STRING)
195 			continue;
196 
197 		/* The second one may be a string, a reference or a package. */
198 		switch (link->package.elements[1].type) {
199 		case ACPI_TYPE_STRING:
200 			result = acpi_nondev_subnode_ok(scope, link, list,
201 							 parent);
202 			break;
203 		case ACPI_TYPE_LOCAL_REFERENCE:
204 			handle = link->package.elements[1].reference.handle;
205 			result = acpi_nondev_subnode_data_ok(handle, link, list,
206 							     parent);
207 			break;
208 		case ACPI_TYPE_PACKAGE:
209 			desc = &link->package.elements[1];
210 			result = acpi_nondev_subnode_extract(desc, NULL, link,
211 							     list, parent);
212 			break;
213 		default:
214 			result = false;
215 			break;
216 		}
217 		ret = ret || result;
218 	}
219 
220 	return ret;
221 }
222 
223 static bool acpi_enumerate_nondev_subnodes(acpi_handle scope,
224 					   union acpi_object *desc,
225 					   struct acpi_device_data *data,
226 					   struct fwnode_handle *parent)
227 {
228 	int i;
229 
230 	/* Look for the ACPI data subnodes GUID. */
231 	for (i = 0; i < desc->package.count; i += 2) {
232 		const union acpi_object *guid;
233 		union acpi_object *links;
234 
235 		guid = &desc->package.elements[i];
236 		links = &desc->package.elements[i + 1];
237 
238 		/*
239 		 * The first element must be a GUID and the second one must be
240 		 * a package.
241 		 */
242 		if (guid->type != ACPI_TYPE_BUFFER ||
243 		    guid->buffer.length != 16 ||
244 		    links->type != ACPI_TYPE_PACKAGE)
245 			break;
246 
247 		if (!guid_equal((guid_t *)guid->buffer.pointer, &ads_guid))
248 			continue;
249 
250 		return acpi_add_nondev_subnodes(scope, links, &data->subnodes,
251 						parent);
252 	}
253 
254 	return false;
255 }
256 
257 static bool acpi_property_value_ok(const union acpi_object *value)
258 {
259 	int j;
260 
261 	/*
262 	 * The value must be an integer, a string, a reference, or a package
263 	 * whose every element must be an integer, a string, or a reference.
264 	 */
265 	switch (value->type) {
266 	case ACPI_TYPE_INTEGER:
267 	case ACPI_TYPE_STRING:
268 	case ACPI_TYPE_LOCAL_REFERENCE:
269 		return true;
270 
271 	case ACPI_TYPE_PACKAGE:
272 		for (j = 0; j < value->package.count; j++)
273 			switch (value->package.elements[j].type) {
274 			case ACPI_TYPE_INTEGER:
275 			case ACPI_TYPE_STRING:
276 			case ACPI_TYPE_LOCAL_REFERENCE:
277 				continue;
278 
279 			default:
280 				return false;
281 			}
282 
283 		return true;
284 	}
285 	return false;
286 }
287 
288 static bool acpi_properties_format_valid(const union acpi_object *properties)
289 {
290 	int i;
291 
292 	for (i = 0; i < properties->package.count; i++) {
293 		const union acpi_object *property;
294 
295 		property = &properties->package.elements[i];
296 		/*
297 		 * Only two elements allowed, the first one must be a string and
298 		 * the second one has to satisfy certain conditions.
299 		 */
300 		if (property->package.count != 2
301 		    || property->package.elements[0].type != ACPI_TYPE_STRING
302 		    || !acpi_property_value_ok(&property->package.elements[1]))
303 			return false;
304 	}
305 	return true;
306 }
307 
308 static void acpi_init_of_compatible(struct acpi_device *adev)
309 {
310 	const union acpi_object *of_compatible;
311 	int ret;
312 
313 	ret = acpi_data_get_property_array(&adev->data, "compatible",
314 					   ACPI_TYPE_STRING, &of_compatible);
315 	if (ret) {
316 		ret = acpi_dev_get_property(adev, "compatible",
317 					    ACPI_TYPE_STRING, &of_compatible);
318 		if (ret) {
319 			struct acpi_device *parent;
320 
321 			parent = acpi_dev_parent(adev);
322 			if (parent && parent->flags.of_compatible_ok)
323 				goto out;
324 
325 			return;
326 		}
327 	}
328 	adev->data.of_compatible = of_compatible;
329 
330  out:
331 	adev->flags.of_compatible_ok = 1;
332 }
333 
334 static bool acpi_is_property_guid(const guid_t *guid)
335 {
336 	int i;
337 
338 	for (i = 0; i < ARRAY_SIZE(prp_guids); i++) {
339 		if (guid_equal(guid, &prp_guids[i]))
340 			return true;
341 	}
342 
343 	return false;
344 }
345 
346 struct acpi_device_properties *
347 acpi_data_add_props(struct acpi_device_data *data, const guid_t *guid,
348 		    union acpi_object *properties)
349 {
350 	struct acpi_device_properties *props;
351 
352 	props = kzalloc(sizeof(*props), GFP_KERNEL);
353 	if (props) {
354 		INIT_LIST_HEAD(&props->list);
355 		props->guid = guid;
356 		props->properties = properties;
357 		list_add_tail(&props->list, &data->properties);
358 	}
359 
360 	return props;
361 }
362 
363 static void acpi_nondev_subnode_tag(acpi_handle handle, void *context)
364 {
365 }
366 
367 static void acpi_untie_nondev_subnodes(struct acpi_device_data *data)
368 {
369 	struct acpi_data_node *dn;
370 
371 	list_for_each_entry(dn, &data->subnodes, sibling) {
372 		acpi_detach_data(dn->handle, acpi_nondev_subnode_tag);
373 
374 		acpi_untie_nondev_subnodes(&dn->data);
375 	}
376 }
377 
378 static bool acpi_tie_nondev_subnodes(struct acpi_device_data *data)
379 {
380 	struct acpi_data_node *dn;
381 
382 	list_for_each_entry(dn, &data->subnodes, sibling) {
383 		acpi_status status;
384 		bool ret;
385 
386 		status = acpi_attach_data(dn->handle, acpi_nondev_subnode_tag, dn);
387 		if (ACPI_FAILURE(status) && status != AE_ALREADY_EXISTS) {
388 			acpi_handle_err(dn->handle, "Can't tag data node\n");
389 			return false;
390 		}
391 
392 		ret = acpi_tie_nondev_subnodes(&dn->data);
393 		if (!ret)
394 			return ret;
395 	}
396 
397 	return true;
398 }
399 
400 static void acpi_data_add_buffer_props(acpi_handle handle,
401 				       struct acpi_device_data *data,
402 				       union acpi_object *properties)
403 {
404 	struct acpi_device_properties *props;
405 	union acpi_object *package;
406 	size_t alloc_size;
407 	unsigned int i;
408 	u32 *count;
409 
410 	if (check_mul_overflow((size_t)properties->package.count,
411 			       sizeof(*package) + sizeof(void *),
412 			       &alloc_size) ||
413 	    check_add_overflow(sizeof(*props) + sizeof(*package), alloc_size,
414 			       &alloc_size)) {
415 		acpi_handle_warn(handle,
416 				 "can't allocate memory for %u buffer props",
417 				 properties->package.count);
418 		return;
419 	}
420 
421 	props = kvzalloc(alloc_size, GFP_KERNEL);
422 	if (!props)
423 		return;
424 
425 	props->guid = &buffer_prop_guid;
426 	props->bufs = (void *)(props + 1);
427 	props->properties = (void *)(props->bufs + properties->package.count);
428 
429 	/* Outer package */
430 	package = props->properties;
431 	package->type = ACPI_TYPE_PACKAGE;
432 	package->package.elements = package + 1;
433 	count = &package->package.count;
434 	*count = 0;
435 
436 	/* Inner packages */
437 	package++;
438 
439 	for (i = 0; i < properties->package.count; i++) {
440 		struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
441 		union acpi_object *property = &properties->package.elements[i];
442 		union acpi_object *prop, *obj, *buf_obj;
443 		acpi_status status;
444 
445 		if (property->type != ACPI_TYPE_PACKAGE ||
446 		    property->package.count != 2) {
447 			acpi_handle_warn(handle,
448 					 "buffer property %u has %u entries\n",
449 					 i, property->package.count);
450 			continue;
451 		}
452 
453 		prop = &property->package.elements[0];
454 		obj = &property->package.elements[1];
455 
456 		if (prop->type != ACPI_TYPE_STRING ||
457 		    obj->type != ACPI_TYPE_STRING) {
458 			acpi_handle_warn(handle,
459 					 "wrong object types %u and %u\n",
460 					 prop->type, obj->type);
461 			continue;
462 		}
463 
464 		status = acpi_evaluate_object_typed(handle, obj->string.pointer,
465 						    NULL, &buf,
466 						    ACPI_TYPE_BUFFER);
467 		if (ACPI_FAILURE(status)) {
468 			acpi_handle_warn(handle,
469 					 "can't evaluate \"%*pE\" as buffer\n",
470 					 obj->string.length,
471 					 obj->string.pointer);
472 			continue;
473 		}
474 
475 		package->type = ACPI_TYPE_PACKAGE;
476 		package->package.elements = prop;
477 		package->package.count = 2;
478 
479 		buf_obj = buf.pointer;
480 
481 		/* Replace the string object with a buffer object */
482 		obj->type = ACPI_TYPE_BUFFER;
483 		obj->buffer.length = buf_obj->buffer.length;
484 		obj->buffer.pointer = buf_obj->buffer.pointer;
485 
486 		props->bufs[i] = buf.pointer;
487 		package++;
488 		(*count)++;
489 	}
490 
491 	if (*count)
492 		list_add(&props->list, &data->properties);
493 	else
494 		kvfree(props);
495 }
496 
497 static bool acpi_extract_properties(acpi_handle scope, union acpi_object *desc,
498 				    struct acpi_device_data *data)
499 {
500 	int i;
501 
502 	if (desc->package.count % 2)
503 		return false;
504 
505 	/* Look for the device properties GUID. */
506 	for (i = 0; i < desc->package.count; i += 2) {
507 		const union acpi_object *guid;
508 		union acpi_object *properties;
509 
510 		guid = &desc->package.elements[i];
511 		properties = &desc->package.elements[i + 1];
512 
513 		/*
514 		 * The first element must be a GUID and the second one must be
515 		 * a package.
516 		 */
517 		if (guid->type != ACPI_TYPE_BUFFER ||
518 		    guid->buffer.length != 16 ||
519 		    properties->type != ACPI_TYPE_PACKAGE)
520 			break;
521 
522 		if (guid_equal((guid_t *)guid->buffer.pointer,
523 			       &buffer_prop_guid)) {
524 			acpi_data_add_buffer_props(scope, data, properties);
525 			continue;
526 		}
527 
528 		if (!acpi_is_property_guid((guid_t *)guid->buffer.pointer))
529 			continue;
530 
531 		/*
532 		 * We found the matching GUID. Now validate the format of the
533 		 * package immediately following it.
534 		 */
535 		if (!acpi_properties_format_valid(properties))
536 			continue;
537 
538 		acpi_data_add_props(data, (const guid_t *)guid->buffer.pointer,
539 				    properties);
540 	}
541 
542 	return !list_empty(&data->properties);
543 }
544 
545 void acpi_init_properties(struct acpi_device *adev)
546 {
547 	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
548 	struct acpi_hardware_id *hwid;
549 	acpi_status status;
550 	bool acpi_of = false;
551 
552 	INIT_LIST_HEAD(&adev->data.properties);
553 	INIT_LIST_HEAD(&adev->data.subnodes);
554 
555 	if (!adev->handle)
556 		return;
557 
558 	/*
559 	 * Check if ACPI_DT_NAMESPACE_HID is present and inthat case we fill in
560 	 * Device Tree compatible properties for this device.
561 	 */
562 	list_for_each_entry(hwid, &adev->pnp.ids, list) {
563 		if (!strcmp(hwid->id, ACPI_DT_NAMESPACE_HID)) {
564 			acpi_of = true;
565 			break;
566 		}
567 	}
568 
569 	status = acpi_evaluate_object_typed(adev->handle, "_DSD", NULL, &buf,
570 					    ACPI_TYPE_PACKAGE);
571 	if (ACPI_FAILURE(status))
572 		goto out;
573 
574 	if (acpi_extract_properties(adev->handle, buf.pointer, &adev->data)) {
575 		adev->data.pointer = buf.pointer;
576 		if (acpi_of)
577 			acpi_init_of_compatible(adev);
578 	}
579 	if (acpi_enumerate_nondev_subnodes(adev->handle, buf.pointer,
580 					&adev->data, acpi_fwnode_handle(adev)))
581 		adev->data.pointer = buf.pointer;
582 
583 	if (!adev->data.pointer) {
584 		acpi_handle_debug(adev->handle, "Invalid _DSD data, skipping\n");
585 		ACPI_FREE(buf.pointer);
586 	} else {
587 		if (!acpi_tie_nondev_subnodes(&adev->data))
588 			acpi_untie_nondev_subnodes(&adev->data);
589 	}
590 
591  out:
592 	if (acpi_of && !adev->flags.of_compatible_ok)
593 		acpi_handle_info(adev->handle,
594 			 ACPI_DT_NAMESPACE_HID " requires 'compatible' property\n");
595 
596 	if (!adev->data.pointer)
597 		acpi_extract_apple_properties(adev);
598 }
599 
600 static void acpi_free_device_properties(struct list_head *list)
601 {
602 	struct acpi_device_properties *props, *tmp;
603 
604 	list_for_each_entry_safe(props, tmp, list, list) {
605 		u32 i;
606 
607 		list_del(&props->list);
608 		/* Buffer data properties were separately allocated */
609 		if (props->bufs)
610 			for (i = 0; i < props->properties->package.count; i++)
611 				ACPI_FREE(props->bufs[i]);
612 		kvfree(props);
613 	}
614 }
615 
616 static void acpi_destroy_nondev_subnodes(struct list_head *list)
617 {
618 	struct acpi_data_node *dn, *next;
619 
620 	if (list_empty(list))
621 		return;
622 
623 	list_for_each_entry_safe_reverse(dn, next, list, sibling) {
624 		acpi_destroy_nondev_subnodes(&dn->data.subnodes);
625 		wait_for_completion(&dn->kobj_done);
626 		list_del(&dn->sibling);
627 		ACPI_FREE((void *)dn->data.pointer);
628 		acpi_free_device_properties(&dn->data.properties);
629 		kfree(dn);
630 	}
631 }
632 
633 void acpi_free_properties(struct acpi_device *adev)
634 {
635 	acpi_untie_nondev_subnodes(&adev->data);
636 	acpi_destroy_nondev_subnodes(&adev->data.subnodes);
637 	ACPI_FREE((void *)adev->data.pointer);
638 	adev->data.of_compatible = NULL;
639 	adev->data.pointer = NULL;
640 	acpi_free_device_properties(&adev->data.properties);
641 }
642 
643 /**
644  * acpi_data_get_property - return an ACPI property with given name
645  * @data: ACPI device deta object to get the property from
646  * @name: Name of the property
647  * @type: Expected property type
648  * @obj: Location to store the property value (if not %NULL)
649  *
650  * Look up a property with @name and store a pointer to the resulting ACPI
651  * object at the location pointed to by @obj if found.
652  *
653  * Callers must not attempt to free the returned objects.  These objects will be
654  * freed by the ACPI core automatically during the removal of @data.
655  *
656  * Return: %0 if property with @name has been found (success),
657  *         %-EINVAL if the arguments are invalid,
658  *         %-EINVAL if the property doesn't exist,
659  *         %-EPROTO if the property value type doesn't match @type.
660  */
661 static int acpi_data_get_property(const struct acpi_device_data *data,
662 				  const char *name, acpi_object_type type,
663 				  const union acpi_object **obj)
664 {
665 	const struct acpi_device_properties *props;
666 
667 	if (!data || !name)
668 		return -EINVAL;
669 
670 	if (!data->pointer || list_empty(&data->properties))
671 		return -EINVAL;
672 
673 	list_for_each_entry(props, &data->properties, list) {
674 		const union acpi_object *properties;
675 		unsigned int i;
676 
677 		properties = props->properties;
678 		for (i = 0; i < properties->package.count; i++) {
679 			const union acpi_object *propname, *propvalue;
680 			const union acpi_object *property;
681 
682 			property = &properties->package.elements[i];
683 
684 			propname = &property->package.elements[0];
685 			propvalue = &property->package.elements[1];
686 
687 			if (!strcmp(name, propname->string.pointer)) {
688 				if (type != ACPI_TYPE_ANY &&
689 				    propvalue->type != type)
690 					return -EPROTO;
691 				if (obj)
692 					*obj = propvalue;
693 
694 				return 0;
695 			}
696 		}
697 	}
698 	return -EINVAL;
699 }
700 
701 /**
702  * acpi_dev_get_property - return an ACPI property with given name.
703  * @adev: ACPI device to get the property from.
704  * @name: Name of the property.
705  * @type: Expected property type.
706  * @obj: Location to store the property value (if not %NULL).
707  */
708 int acpi_dev_get_property(const struct acpi_device *adev, const char *name,
709 			  acpi_object_type type, const union acpi_object **obj)
710 {
711 	return adev ? acpi_data_get_property(&adev->data, name, type, obj) : -EINVAL;
712 }
713 EXPORT_SYMBOL_GPL(acpi_dev_get_property);
714 
715 static const struct acpi_device_data *
716 acpi_device_data_of_node(const struct fwnode_handle *fwnode)
717 {
718 	if (is_acpi_device_node(fwnode)) {
719 		const struct acpi_device *adev = to_acpi_device_node(fwnode);
720 		return &adev->data;
721 	}
722 	if (is_acpi_data_node(fwnode)) {
723 		const struct acpi_data_node *dn = to_acpi_data_node(fwnode);
724 		return &dn->data;
725 	}
726 	return NULL;
727 }
728 
729 /**
730  * acpi_node_prop_get - return an ACPI property with given name.
731  * @fwnode: Firmware node to get the property from.
732  * @propname: Name of the property.
733  * @valptr: Location to store a pointer to the property value (if not %NULL).
734  */
735 int acpi_node_prop_get(const struct fwnode_handle *fwnode,
736 		       const char *propname, void **valptr)
737 {
738 	return acpi_data_get_property(acpi_device_data_of_node(fwnode),
739 				      propname, ACPI_TYPE_ANY,
740 				      (const union acpi_object **)valptr);
741 }
742 
743 /**
744  * acpi_data_get_property_array - return an ACPI array property with given name
745  * @data: ACPI data object to get the property from
746  * @name: Name of the property
747  * @type: Expected type of array elements
748  * @obj: Location to store a pointer to the property value (if not NULL)
749  *
750  * Look up an array property with @name and store a pointer to the resulting
751  * ACPI object at the location pointed to by @obj if found.
752  *
753  * Callers must not attempt to free the returned objects.  Those objects will be
754  * freed by the ACPI core automatically during the removal of @data.
755  *
756  * Return: %0 if array property (package) with @name has been found (success),
757  *         %-EINVAL if the arguments are invalid,
758  *         %-EINVAL if the property doesn't exist,
759  *         %-EPROTO if the property is not a package or the type of its elements
760  *           doesn't match @type.
761  */
762 static int acpi_data_get_property_array(const struct acpi_device_data *data,
763 					const char *name,
764 					acpi_object_type type,
765 					const union acpi_object **obj)
766 {
767 	const union acpi_object *prop;
768 	int ret, i;
769 
770 	ret = acpi_data_get_property(data, name, ACPI_TYPE_PACKAGE, &prop);
771 	if (ret)
772 		return ret;
773 
774 	if (type != ACPI_TYPE_ANY) {
775 		/* Check that all elements are of correct type. */
776 		for (i = 0; i < prop->package.count; i++)
777 			if (prop->package.elements[i].type != type)
778 				return -EPROTO;
779 	}
780 	if (obj)
781 		*obj = prop;
782 
783 	return 0;
784 }
785 
786 static struct fwnode_handle *
787 acpi_fwnode_get_named_child_node(const struct fwnode_handle *fwnode,
788 				 const char *childname)
789 {
790 	struct fwnode_handle *child;
791 
792 	fwnode_for_each_child_node(fwnode, child) {
793 		if (is_acpi_data_node(child)) {
794 			if (acpi_data_node_match(child, childname))
795 				return child;
796 			continue;
797 		}
798 
799 		if (!strncmp(acpi_device_bid(to_acpi_device_node(child)),
800 			     childname, ACPI_NAMESEG_SIZE))
801 			return child;
802 	}
803 
804 	return NULL;
805 }
806 
807 static int acpi_get_ref_args(struct fwnode_reference_args *args,
808 			     struct fwnode_handle *ref_fwnode,
809 			     const union acpi_object **element,
810 			     const union acpi_object *end, size_t num_args)
811 {
812 	u32 nargs = 0, i;
813 
814 	/*
815 	 * Assume the following integer elements are all args. Stop counting on
816 	 * the first reference (possibly represented as a string) or end of the
817 	 * package arguments. In case of neither reference, nor integer, return
818 	 * an error, we can't parse it.
819 	 */
820 	for (i = 0; (*element) + i < end && i < num_args; i++) {
821 		acpi_object_type type = (*element)[i].type;
822 
823 		if (type == ACPI_TYPE_LOCAL_REFERENCE || type == ACPI_TYPE_STRING)
824 			break;
825 
826 		if (type == ACPI_TYPE_INTEGER)
827 			nargs++;
828 		else
829 			return -EINVAL;
830 	}
831 
832 	if (nargs > NR_FWNODE_REFERENCE_ARGS)
833 		return -EINVAL;
834 
835 	if (args) {
836 		args->fwnode = ref_fwnode;
837 		args->nargs = nargs;
838 		for (i = 0; i < nargs; i++)
839 			args->args[i] = (*element)[i].integer.value;
840 	}
841 
842 	(*element) += nargs;
843 
844 	return 0;
845 }
846 
847 static struct fwnode_handle *acpi_parse_string_ref(const struct fwnode_handle *fwnode,
848 						   const char *refstring)
849 {
850 	acpi_handle scope, handle;
851 	struct acpi_data_node *dn;
852 	struct acpi_device *device;
853 	acpi_status status;
854 
855 	if (is_acpi_device_node(fwnode)) {
856 		scope = to_acpi_device_node(fwnode)->handle;
857 	} else if (is_acpi_data_node(fwnode)) {
858 		scope = to_acpi_data_node(fwnode)->handle;
859 	} else {
860 		pr_debug("Bad node type for node %pfw\n", fwnode);
861 		return NULL;
862 	}
863 
864 	status = acpi_get_handle(scope, refstring, &handle);
865 	if (ACPI_FAILURE(status)) {
866 		acpi_handle_debug(scope, "Unable to get an ACPI handle for %s\n",
867 				  refstring);
868 		return NULL;
869 	}
870 
871 	device = acpi_fetch_acpi_dev(handle);
872 	if (device)
873 		return acpi_fwnode_handle(device);
874 
875 	status = acpi_get_data_full(handle, acpi_nondev_subnode_tag,
876 				    (void **)&dn, NULL);
877 	if (ACPI_FAILURE(status) || !dn) {
878 		acpi_handle_debug(handle, "Subnode not found\n");
879 		return NULL;
880 	}
881 
882 	return &dn->fwnode;
883 }
884 
885 /**
886  * __acpi_node_get_property_reference - returns handle to the referenced object
887  * @fwnode: Firmware node to get the property from
888  * @propname: Name of the property
889  * @index: Index of the reference to return
890  * @num_args: Maximum number of arguments after each reference
891  * @args: Location to store the returned reference with optional arguments
892  *	  (may be NULL)
893  *
894  * Find property with @name, verifify that it is a package containing at least
895  * one object reference and if so, store the ACPI device object pointer to the
896  * target object in @args->adev.  If the reference includes arguments, store
897  * them in the @args->args[] array.
898  *
899  * If there's more than one reference in the property value package, @index is
900  * used to select the one to return.
901  *
902  * It is possible to leave holes in the property value set like in the
903  * example below:
904  *
905  * Package () {
906  *     "cs-gpios",
907  *     Package () {
908  *        ^GPIO, 19, 0, 0,
909  *        ^GPIO, 20, 0, 0,
910  *        0,
911  *        ^GPIO, 21, 0, 0,
912  *     }
913  * }
914  *
915  * Calling this function with index %2 or index %3 return %-ENOENT. If the
916  * property does not contain any more values %-ENOENT is returned. The NULL
917  * entry must be single integer and preferably contain value %0.
918  *
919  * Return: %0 on success, negative error code on failure.
920  */
921 int __acpi_node_get_property_reference(const struct fwnode_handle *fwnode,
922 	const char *propname, size_t index, size_t num_args,
923 	struct fwnode_reference_args *args)
924 {
925 	const union acpi_object *element, *end;
926 	const union acpi_object *obj;
927 	const struct acpi_device_data *data;
928 	struct fwnode_handle *ref_fwnode;
929 	struct acpi_device *device;
930 	int ret, idx = 0;
931 
932 	data = acpi_device_data_of_node(fwnode);
933 	if (!data)
934 		return -ENOENT;
935 
936 	ret = acpi_data_get_property(data, propname, ACPI_TYPE_ANY, &obj);
937 	if (ret)
938 		return ret == -EINVAL ? -ENOENT : -EINVAL;
939 
940 	switch (obj->type) {
941 	case ACPI_TYPE_LOCAL_REFERENCE:
942 		/* Plain single reference without arguments. */
943 		if (index)
944 			return -ENOENT;
945 
946 		device = acpi_fetch_acpi_dev(obj->reference.handle);
947 		if (!device)
948 			return -EINVAL;
949 
950 		if (!args)
951 			return 0;
952 
953 		args->fwnode = acpi_fwnode_handle(device);
954 		args->nargs = 0;
955 
956 		return 0;
957 	case ACPI_TYPE_STRING:
958 		if (index)
959 			return -ENOENT;
960 
961 		ref_fwnode = acpi_parse_string_ref(fwnode, obj->string.pointer);
962 		if (!ref_fwnode)
963 			return -EINVAL;
964 
965 		args->fwnode = ref_fwnode;
966 		args->nargs = 0;
967 
968 		return 0;
969 	case ACPI_TYPE_PACKAGE:
970 		/*
971 		 * If it is not a single reference, then it is a package of
972 		 * references, followed by number of ints as follows:
973 		 *
974 		 *  Package () { REF, INT, REF, INT, INT }
975 		 *
976 		 * Here, REF may be either a local reference or a string. The
977 		 * index argument is then used to determine which reference the
978 		 * caller wants (along with the arguments).
979 		 */
980 		break;
981 	default:
982 		return -EINVAL;
983 	}
984 
985 	if (index >= obj->package.count)
986 		return -ENOENT;
987 
988 	element = obj->package.elements;
989 	end = element + obj->package.count;
990 
991 	while (element < end) {
992 		switch (element->type) {
993 		case ACPI_TYPE_LOCAL_REFERENCE:
994 			device = acpi_fetch_acpi_dev(element->reference.handle);
995 			if (!device)
996 				return -EINVAL;
997 
998 			element++;
999 
1000 			ret = acpi_get_ref_args(idx == index ? args : NULL,
1001 						acpi_fwnode_handle(device),
1002 						&element, end, num_args);
1003 			if (ret < 0)
1004 				return ret;
1005 
1006 			if (idx == index)
1007 				return 0;
1008 
1009 			break;
1010 		case ACPI_TYPE_STRING:
1011 			ref_fwnode = acpi_parse_string_ref(fwnode,
1012 							   element->string.pointer);
1013 			if (!ref_fwnode)
1014 				return -EINVAL;
1015 
1016 			element++;
1017 
1018 			ret = acpi_get_ref_args(idx == index ? args : NULL,
1019 						ref_fwnode, &element, end,
1020 						num_args);
1021 			if (ret < 0)
1022 				return ret;
1023 
1024 			if (idx == index)
1025 				return 0;
1026 
1027 			break;
1028 		case ACPI_TYPE_INTEGER:
1029 			if (idx == index)
1030 				return -ENOENT;
1031 			element++;
1032 			break;
1033 		default:
1034 			return -EINVAL;
1035 		}
1036 
1037 		idx++;
1038 	}
1039 
1040 	return -ENOENT;
1041 }
1042 EXPORT_SYMBOL_GPL(__acpi_node_get_property_reference);
1043 
1044 static int acpi_data_prop_read_single(const struct acpi_device_data *data,
1045 				      const char *propname,
1046 				      enum dev_prop_type proptype, void *val)
1047 {
1048 	const union acpi_object *obj;
1049 	int ret = 0;
1050 
1051 	if (proptype >= DEV_PROP_U8 && proptype <= DEV_PROP_U64)
1052 		ret = acpi_data_get_property(data, propname, ACPI_TYPE_INTEGER, &obj);
1053 	else if (proptype == DEV_PROP_STRING)
1054 		ret = acpi_data_get_property(data, propname, ACPI_TYPE_STRING, &obj);
1055 	if (ret)
1056 		return ret;
1057 
1058 	switch (proptype) {
1059 	case DEV_PROP_U8:
1060 		if (obj->integer.value > U8_MAX)
1061 			return -EOVERFLOW;
1062 		if (val)
1063 			*(u8 *)val = obj->integer.value;
1064 		break;
1065 	case DEV_PROP_U16:
1066 		if (obj->integer.value > U16_MAX)
1067 			return -EOVERFLOW;
1068 		if (val)
1069 			*(u16 *)val = obj->integer.value;
1070 		break;
1071 	case DEV_PROP_U32:
1072 		if (obj->integer.value > U32_MAX)
1073 			return -EOVERFLOW;
1074 		if (val)
1075 			*(u32 *)val = obj->integer.value;
1076 		break;
1077 	case DEV_PROP_U64:
1078 		if (val)
1079 			*(u64 *)val = obj->integer.value;
1080 		break;
1081 	case DEV_PROP_STRING:
1082 		if (val)
1083 			*(char **)val = obj->string.pointer;
1084 		return 1;
1085 	default:
1086 		return -EINVAL;
1087 	}
1088 
1089 	/* When no storage provided return number of available values */
1090 	return val ? 0 : 1;
1091 }
1092 
1093 #define acpi_copy_property_array_uint(items, val, nval)			\
1094 	({								\
1095 		typeof(items) __items = items;				\
1096 		typeof(val) __val = val;				\
1097 		typeof(nval) __nval = nval;				\
1098 		size_t i;						\
1099 		int ret = 0;						\
1100 									\
1101 		for (i = 0; i < __nval; i++) {				\
1102 			if (__items->type == ACPI_TYPE_BUFFER) {	\
1103 				__val[i] = __items->buffer.pointer[i];	\
1104 				continue;				\
1105 			}						\
1106 			if (__items[i].type != ACPI_TYPE_INTEGER) {	\
1107 				ret = -EPROTO;				\
1108 				break;					\
1109 			}						\
1110 			if (__items[i].integer.value > _Generic(__val,	\
1111 								u8 *: U8_MAX, \
1112 								u16 *: U16_MAX, \
1113 								u32 *: U32_MAX, \
1114 								u64 *: U64_MAX)) { \
1115 				ret = -EOVERFLOW;			\
1116 				break;					\
1117 			}						\
1118 									\
1119 			__val[i] = __items[i].integer.value;		\
1120 		}							\
1121 		ret;							\
1122 	})
1123 
1124 static int acpi_copy_property_array_string(const union acpi_object *items,
1125 					   char **val, size_t nval)
1126 {
1127 	int i;
1128 
1129 	for (i = 0; i < nval; i++) {
1130 		if (items[i].type != ACPI_TYPE_STRING)
1131 			return -EPROTO;
1132 
1133 		val[i] = items[i].string.pointer;
1134 	}
1135 	return nval;
1136 }
1137 
1138 static int acpi_data_prop_read(const struct acpi_device_data *data,
1139 			       const char *propname,
1140 			       enum dev_prop_type proptype,
1141 			       void *val, size_t nval)
1142 {
1143 	const union acpi_object *obj;
1144 	const union acpi_object *items;
1145 	int ret;
1146 
1147 	if (nval == 1 || !val) {
1148 		ret = acpi_data_prop_read_single(data, propname, proptype, val);
1149 		/*
1150 		 * The overflow error means that the property is there and it is
1151 		 * single-value, but its type does not match, so return.
1152 		 */
1153 		if (ret >= 0 || ret == -EOVERFLOW)
1154 			return ret;
1155 
1156 		/*
1157 		 * Reading this property as a single-value one failed, but its
1158 		 * value may still be represented as one-element array, so
1159 		 * continue.
1160 		 */
1161 	}
1162 
1163 	ret = acpi_data_get_property_array(data, propname, ACPI_TYPE_ANY, &obj);
1164 	if (ret && proptype >= DEV_PROP_U8 && proptype <= DEV_PROP_U64)
1165 		ret = acpi_data_get_property(data, propname, ACPI_TYPE_BUFFER,
1166 					     &obj);
1167 	if (ret)
1168 		return ret;
1169 
1170 	if (!val) {
1171 		if (obj->type == ACPI_TYPE_BUFFER)
1172 			return obj->buffer.length;
1173 
1174 		return obj->package.count;
1175 	}
1176 
1177 	switch (proptype) {
1178 	case DEV_PROP_STRING:
1179 		break;
1180 	default:
1181 		if (obj->type == ACPI_TYPE_BUFFER) {
1182 			if (nval > obj->buffer.length)
1183 				return -EOVERFLOW;
1184 		} else {
1185 			if (nval > obj->package.count)
1186 				return -EOVERFLOW;
1187 		}
1188 		break;
1189 	}
1190 	if (nval == 0)
1191 		return -EINVAL;
1192 
1193 	if (obj->type == ACPI_TYPE_BUFFER) {
1194 		if (proptype != DEV_PROP_U8)
1195 			return -EPROTO;
1196 		items = obj;
1197 	} else {
1198 		items = obj->package.elements;
1199 	}
1200 
1201 	switch (proptype) {
1202 	case DEV_PROP_U8:
1203 		ret = acpi_copy_property_array_uint(items, (u8 *)val, nval);
1204 		break;
1205 	case DEV_PROP_U16:
1206 		ret = acpi_copy_property_array_uint(items, (u16 *)val, nval);
1207 		break;
1208 	case DEV_PROP_U32:
1209 		ret = acpi_copy_property_array_uint(items, (u32 *)val, nval);
1210 		break;
1211 	case DEV_PROP_U64:
1212 		ret = acpi_copy_property_array_uint(items, (u64 *)val, nval);
1213 		break;
1214 	case DEV_PROP_STRING:
1215 		ret = acpi_copy_property_array_string(
1216 			items, (char **)val,
1217 			min_t(u32, nval, obj->package.count));
1218 		break;
1219 	default:
1220 		ret = -EINVAL;
1221 		break;
1222 	}
1223 	return ret;
1224 }
1225 
1226 /**
1227  * acpi_node_prop_read - retrieve the value of an ACPI property with given name.
1228  * @fwnode: Firmware node to get the property from.
1229  * @propname: Name of the property.
1230  * @proptype: Expected property type.
1231  * @val: Location to store the property value (if not %NULL).
1232  * @nval: Size of the array pointed to by @val.
1233  *
1234  * If @val is %NULL, return the number of array elements comprising the value
1235  * of the property.  Otherwise, read at most @nval values to the array at the
1236  * location pointed to by @val.
1237  */
1238 static int acpi_node_prop_read(const struct fwnode_handle *fwnode,
1239 			       const char *propname, enum dev_prop_type proptype,
1240 			       void *val, size_t nval)
1241 {
1242 	return acpi_data_prop_read(acpi_device_data_of_node(fwnode),
1243 				   propname, proptype, val, nval);
1244 }
1245 
1246 static int stop_on_next(struct acpi_device *adev, void *data)
1247 {
1248 	struct acpi_device **ret_p = data;
1249 
1250 	if (!*ret_p) {
1251 		*ret_p = adev;
1252 		return 1;
1253 	}
1254 
1255 	/* Skip until the "previous" object is found. */
1256 	if (*ret_p == adev)
1257 		*ret_p = NULL;
1258 
1259 	return 0;
1260 }
1261 
1262 /**
1263  * acpi_get_next_subnode - Return the next child node handle for a fwnode
1264  * @fwnode: Firmware node to find the next child node for.
1265  * @child: Handle to one of the device's child nodes or a null handle.
1266  */
1267 struct fwnode_handle *acpi_get_next_subnode(const struct fwnode_handle *fwnode,
1268 					    struct fwnode_handle *child)
1269 {
1270 	struct acpi_device *adev = to_acpi_device_node(fwnode);
1271 
1272 	if ((!child || is_acpi_device_node(child)) && adev) {
1273 		struct acpi_device *child_adev = to_acpi_device_node(child);
1274 
1275 		acpi_dev_for_each_child(adev, stop_on_next, &child_adev);
1276 		if (child_adev)
1277 			return acpi_fwnode_handle(child_adev);
1278 
1279 		child = NULL;
1280 	}
1281 
1282 	if (!child || is_acpi_data_node(child)) {
1283 		const struct acpi_data_node *data = to_acpi_data_node(fwnode);
1284 		const struct list_head *head;
1285 		struct list_head *next;
1286 		struct acpi_data_node *dn;
1287 
1288 		/*
1289 		 * We can have a combination of device and data nodes, e.g. with
1290 		 * hierarchical _DSD properties. Make sure the adev pointer is
1291 		 * restored before going through data nodes, otherwise we will
1292 		 * be looking for data_nodes below the last device found instead
1293 		 * of the common fwnode shared by device_nodes and data_nodes.
1294 		 */
1295 		adev = to_acpi_device_node(fwnode);
1296 		if (adev)
1297 			head = &adev->data.subnodes;
1298 		else if (data)
1299 			head = &data->data.subnodes;
1300 		else
1301 			return NULL;
1302 
1303 		if (list_empty(head))
1304 			return NULL;
1305 
1306 		if (child) {
1307 			dn = to_acpi_data_node(child);
1308 			next = dn->sibling.next;
1309 			if (next == head)
1310 				return NULL;
1311 
1312 			dn = list_entry(next, struct acpi_data_node, sibling);
1313 		} else {
1314 			dn = list_first_entry(head, struct acpi_data_node, sibling);
1315 		}
1316 		return &dn->fwnode;
1317 	}
1318 	return NULL;
1319 }
1320 
1321 /**
1322  * acpi_node_get_parent - Return parent fwnode of this fwnode
1323  * @fwnode: Firmware node whose parent to get
1324  *
1325  * Returns parent node of an ACPI device or data firmware node or %NULL if
1326  * not available.
1327  */
1328 static struct fwnode_handle *
1329 acpi_node_get_parent(const struct fwnode_handle *fwnode)
1330 {
1331 	if (is_acpi_data_node(fwnode)) {
1332 		/* All data nodes have parent pointer so just return that */
1333 		return to_acpi_data_node(fwnode)->parent;
1334 	}
1335 	if (is_acpi_device_node(fwnode)) {
1336 		struct acpi_device *parent;
1337 
1338 		parent = acpi_dev_parent(to_acpi_device_node(fwnode));
1339 		if (parent)
1340 			return acpi_fwnode_handle(parent);
1341 	}
1342 
1343 	return NULL;
1344 }
1345 
1346 /*
1347  * Return true if the node is an ACPI graph node. Called on either ports
1348  * or endpoints.
1349  */
1350 static bool is_acpi_graph_node(struct fwnode_handle *fwnode,
1351 			       const char *str)
1352 {
1353 	unsigned int len = strlen(str);
1354 	const char *name;
1355 
1356 	if (!len || !is_acpi_data_node(fwnode))
1357 		return false;
1358 
1359 	name = to_acpi_data_node(fwnode)->name;
1360 
1361 	return (fwnode_property_present(fwnode, "reg") &&
1362 		!strncmp(name, str, len) && name[len] == '@') ||
1363 		fwnode_property_present(fwnode, str);
1364 }
1365 
1366 /**
1367  * acpi_graph_get_next_endpoint - Get next endpoint ACPI firmware node
1368  * @fwnode: Pointer to the parent firmware node
1369  * @prev: Previous endpoint node or %NULL to get the first
1370  *
1371  * Looks up next endpoint ACPI firmware node below a given @fwnode. Returns
1372  * %NULL if there is no next endpoint or in case of error. In case of success
1373  * the next endpoint is returned.
1374  */
1375 static struct fwnode_handle *acpi_graph_get_next_endpoint(
1376 	const struct fwnode_handle *fwnode, struct fwnode_handle *prev)
1377 {
1378 	struct fwnode_handle *port = NULL;
1379 	struct fwnode_handle *endpoint;
1380 
1381 	if (!prev) {
1382 		do {
1383 			port = fwnode_get_next_child_node(fwnode, port);
1384 			/*
1385 			 * The names of the port nodes begin with "port@"
1386 			 * followed by the number of the port node and they also
1387 			 * have a "reg" property that also has the number of the
1388 			 * port node. For compatibility reasons a node is also
1389 			 * recognised as a port node from the "port" property.
1390 			 */
1391 			if (is_acpi_graph_node(port, "port"))
1392 				break;
1393 		} while (port);
1394 	} else {
1395 		port = fwnode_get_parent(prev);
1396 	}
1397 
1398 	if (!port)
1399 		return NULL;
1400 
1401 	endpoint = fwnode_get_next_child_node(port, prev);
1402 	while (!endpoint) {
1403 		port = fwnode_get_next_child_node(fwnode, port);
1404 		if (!port)
1405 			break;
1406 		if (is_acpi_graph_node(port, "port"))
1407 			endpoint = fwnode_get_next_child_node(port, NULL);
1408 	}
1409 
1410 	/*
1411 	 * The names of the endpoint nodes begin with "endpoint@" followed by
1412 	 * the number of the endpoint node and they also have a "reg" property
1413 	 * that also has the number of the endpoint node. For compatibility
1414 	 * reasons a node is also recognised as an endpoint node from the
1415 	 * "endpoint" property.
1416 	 */
1417 	if (!is_acpi_graph_node(endpoint, "endpoint"))
1418 		return NULL;
1419 
1420 	return endpoint;
1421 }
1422 
1423 /**
1424  * acpi_graph_get_child_prop_value - Return a child with a given property value
1425  * @fwnode: device fwnode
1426  * @prop_name: The name of the property to look for
1427  * @val: the desired property value
1428  *
1429  * Return the port node corresponding to a given port number. Returns
1430  * the child node on success, NULL otherwise.
1431  */
1432 static struct fwnode_handle *acpi_graph_get_child_prop_value(
1433 	const struct fwnode_handle *fwnode, const char *prop_name,
1434 	unsigned int val)
1435 {
1436 	struct fwnode_handle *child;
1437 
1438 	fwnode_for_each_child_node(fwnode, child) {
1439 		u32 nr;
1440 
1441 		if (fwnode_property_read_u32(child, prop_name, &nr))
1442 			continue;
1443 
1444 		if (val == nr)
1445 			return child;
1446 	}
1447 
1448 	return NULL;
1449 }
1450 
1451 
1452 /**
1453  * acpi_graph_get_remote_endpoint - Parses and returns remote end of an endpoint
1454  * @__fwnode: Endpoint firmware node pointing to a remote device
1455  *
1456  * Returns the remote endpoint corresponding to @__fwnode. NULL on error.
1457  */
1458 static struct fwnode_handle *
1459 acpi_graph_get_remote_endpoint(const struct fwnode_handle *__fwnode)
1460 {
1461 	struct fwnode_handle *fwnode;
1462 	unsigned int port_nr, endpoint_nr;
1463 	struct fwnode_reference_args args;
1464 	int ret;
1465 
1466 	memset(&args, 0, sizeof(args));
1467 	ret = acpi_node_get_property_reference(__fwnode, "remote-endpoint", 0,
1468 					       &args);
1469 	if (ret)
1470 		return NULL;
1471 
1472 	/* Direct endpoint reference? */
1473 	if (!is_acpi_device_node(args.fwnode))
1474 		return args.nargs ? NULL : args.fwnode;
1475 
1476 	/*
1477 	 * Always require two arguments with the reference: port and
1478 	 * endpoint indices.
1479 	 */
1480 	if (args.nargs != 2)
1481 		return NULL;
1482 
1483 	fwnode = args.fwnode;
1484 	port_nr = args.args[0];
1485 	endpoint_nr = args.args[1];
1486 
1487 	fwnode = acpi_graph_get_child_prop_value(fwnode, "port", port_nr);
1488 
1489 	return acpi_graph_get_child_prop_value(fwnode, "endpoint", endpoint_nr);
1490 }
1491 
1492 static bool acpi_fwnode_device_is_available(const struct fwnode_handle *fwnode)
1493 {
1494 	if (!is_acpi_device_node(fwnode))
1495 		return false;
1496 
1497 	return acpi_device_is_present(to_acpi_device_node(fwnode));
1498 }
1499 
1500 static const void *
1501 acpi_fwnode_device_get_match_data(const struct fwnode_handle *fwnode,
1502 				  const struct device *dev)
1503 {
1504 	return acpi_device_get_match_data(dev);
1505 }
1506 
1507 static bool acpi_fwnode_device_dma_supported(const struct fwnode_handle *fwnode)
1508 {
1509 	return acpi_dma_supported(to_acpi_device_node(fwnode));
1510 }
1511 
1512 static enum dev_dma_attr
1513 acpi_fwnode_device_get_dma_attr(const struct fwnode_handle *fwnode)
1514 {
1515 	return acpi_get_dma_attr(to_acpi_device_node(fwnode));
1516 }
1517 
1518 static bool acpi_fwnode_property_present(const struct fwnode_handle *fwnode,
1519 					 const char *propname)
1520 {
1521 	return !acpi_node_prop_get(fwnode, propname, NULL);
1522 }
1523 
1524 static int
1525 acpi_fwnode_property_read_int_array(const struct fwnode_handle *fwnode,
1526 				    const char *propname,
1527 				    unsigned int elem_size, void *val,
1528 				    size_t nval)
1529 {
1530 	enum dev_prop_type type;
1531 
1532 	switch (elem_size) {
1533 	case sizeof(u8):
1534 		type = DEV_PROP_U8;
1535 		break;
1536 	case sizeof(u16):
1537 		type = DEV_PROP_U16;
1538 		break;
1539 	case sizeof(u32):
1540 		type = DEV_PROP_U32;
1541 		break;
1542 	case sizeof(u64):
1543 		type = DEV_PROP_U64;
1544 		break;
1545 	default:
1546 		return -ENXIO;
1547 	}
1548 
1549 	return acpi_node_prop_read(fwnode, propname, type, val, nval);
1550 }
1551 
1552 static int
1553 acpi_fwnode_property_read_string_array(const struct fwnode_handle *fwnode,
1554 				       const char *propname, const char **val,
1555 				       size_t nval)
1556 {
1557 	return acpi_node_prop_read(fwnode, propname, DEV_PROP_STRING,
1558 				   val, nval);
1559 }
1560 
1561 static int
1562 acpi_fwnode_get_reference_args(const struct fwnode_handle *fwnode,
1563 			       const char *prop, const char *nargs_prop,
1564 			       unsigned int args_count, unsigned int index,
1565 			       struct fwnode_reference_args *args)
1566 {
1567 	return __acpi_node_get_property_reference(fwnode, prop, index,
1568 						  args_count, args);
1569 }
1570 
1571 static const char *acpi_fwnode_get_name(const struct fwnode_handle *fwnode)
1572 {
1573 	const struct acpi_device *adev;
1574 	struct fwnode_handle *parent;
1575 
1576 	/* Is this the root node? */
1577 	parent = fwnode_get_parent(fwnode);
1578 	if (!parent)
1579 		return "\\";
1580 
1581 	fwnode_handle_put(parent);
1582 
1583 	if (is_acpi_data_node(fwnode)) {
1584 		const struct acpi_data_node *dn = to_acpi_data_node(fwnode);
1585 
1586 		return dn->name;
1587 	}
1588 
1589 	adev = to_acpi_device_node(fwnode);
1590 	if (WARN_ON(!adev))
1591 		return NULL;
1592 
1593 	return acpi_device_bid(adev);
1594 }
1595 
1596 static const char *
1597 acpi_fwnode_get_name_prefix(const struct fwnode_handle *fwnode)
1598 {
1599 	struct fwnode_handle *parent;
1600 
1601 	/* Is this the root node? */
1602 	parent = fwnode_get_parent(fwnode);
1603 	if (!parent)
1604 		return "";
1605 
1606 	/* Is this 2nd node from the root? */
1607 	parent = fwnode_get_next_parent(parent);
1608 	if (!parent)
1609 		return "";
1610 
1611 	fwnode_handle_put(parent);
1612 
1613 	/* ACPI device or data node. */
1614 	return ".";
1615 }
1616 
1617 static struct fwnode_handle *
1618 acpi_fwnode_get_parent(struct fwnode_handle *fwnode)
1619 {
1620 	return acpi_node_get_parent(fwnode);
1621 }
1622 
1623 static int acpi_fwnode_graph_parse_endpoint(const struct fwnode_handle *fwnode,
1624 					    struct fwnode_endpoint *endpoint)
1625 {
1626 	struct fwnode_handle *port_fwnode = fwnode_get_parent(fwnode);
1627 
1628 	endpoint->local_fwnode = fwnode;
1629 
1630 	if (fwnode_property_read_u32(port_fwnode, "reg", &endpoint->port))
1631 		fwnode_property_read_u32(port_fwnode, "port", &endpoint->port);
1632 	if (fwnode_property_read_u32(fwnode, "reg", &endpoint->id))
1633 		fwnode_property_read_u32(fwnode, "endpoint", &endpoint->id);
1634 
1635 	return 0;
1636 }
1637 
1638 static int acpi_fwnode_irq_get(const struct fwnode_handle *fwnode,
1639 			       unsigned int index)
1640 {
1641 	struct resource res;
1642 	int ret;
1643 
1644 	ret = acpi_irq_get(ACPI_HANDLE_FWNODE(fwnode), index, &res);
1645 	if (ret)
1646 		return ret;
1647 
1648 	return res.start;
1649 }
1650 
1651 #define DECLARE_ACPI_FWNODE_OPS(ops) \
1652 	const struct fwnode_operations ops = {				\
1653 		.device_is_available = acpi_fwnode_device_is_available, \
1654 		.device_get_match_data = acpi_fwnode_device_get_match_data, \
1655 		.device_dma_supported =				\
1656 			acpi_fwnode_device_dma_supported,		\
1657 		.device_get_dma_attr = acpi_fwnode_device_get_dma_attr,	\
1658 		.property_present = acpi_fwnode_property_present,	\
1659 		.property_read_int_array =				\
1660 			acpi_fwnode_property_read_int_array,		\
1661 		.property_read_string_array =				\
1662 			acpi_fwnode_property_read_string_array,		\
1663 		.get_parent = acpi_node_get_parent,			\
1664 		.get_next_child_node = acpi_get_next_subnode,		\
1665 		.get_named_child_node = acpi_fwnode_get_named_child_node, \
1666 		.get_name = acpi_fwnode_get_name,			\
1667 		.get_name_prefix = acpi_fwnode_get_name_prefix,		\
1668 		.get_reference_args = acpi_fwnode_get_reference_args,	\
1669 		.graph_get_next_endpoint =				\
1670 			acpi_graph_get_next_endpoint,			\
1671 		.graph_get_remote_endpoint =				\
1672 			acpi_graph_get_remote_endpoint,			\
1673 		.graph_get_port_parent = acpi_fwnode_get_parent,	\
1674 		.graph_parse_endpoint = acpi_fwnode_graph_parse_endpoint, \
1675 		.irq_get = acpi_fwnode_irq_get,				\
1676 	};								\
1677 	EXPORT_SYMBOL_GPL(ops)
1678 
1679 DECLARE_ACPI_FWNODE_OPS(acpi_device_fwnode_ops);
1680 DECLARE_ACPI_FWNODE_OPS(acpi_data_fwnode_ops);
1681 const struct fwnode_operations acpi_static_fwnode_ops;
1682 
1683 bool is_acpi_device_node(const struct fwnode_handle *fwnode)
1684 {
1685 	return !IS_ERR_OR_NULL(fwnode) &&
1686 		fwnode->ops == &acpi_device_fwnode_ops;
1687 }
1688 EXPORT_SYMBOL(is_acpi_device_node);
1689 
1690 bool is_acpi_data_node(const struct fwnode_handle *fwnode)
1691 {
1692 	return !IS_ERR_OR_NULL(fwnode) && fwnode->ops == &acpi_data_fwnode_ops;
1693 }
1694 EXPORT_SYMBOL(is_acpi_data_node);
1695