xref: /linux/drivers/acpi/property.c (revision 1e525507)
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 static const guid_t prp_guids[] = {
36 	/* ACPI _DSD device properties GUID: daffd814-6eba-4d8c-8a91-bc9bbf4aa301 */
37 	GUID_INIT(0xdaffd814, 0x6eba, 0x4d8c,
38 		  0x8a, 0x91, 0xbc, 0x9b, 0xbf, 0x4a, 0xa3, 0x01),
39 	/* Hotplug in D3 GUID: 6211e2c0-58a3-4af3-90e1-927a4e0c55a4 */
40 	GUID_INIT(0x6211e2c0, 0x58a3, 0x4af3,
41 		  0x90, 0xe1, 0x92, 0x7a, 0x4e, 0x0c, 0x55, 0xa4),
42 	/* External facing port GUID: efcc06cc-73ac-4bc3-bff0-76143807c389 */
43 	GUID_INIT(0xefcc06cc, 0x73ac, 0x4bc3,
44 		  0xbf, 0xf0, 0x76, 0x14, 0x38, 0x07, 0xc3, 0x89),
45 	/* Thunderbolt GUID for IMR_VALID: c44d002f-69f9-4e7d-a904-a7baabdf43f7 */
46 	GUID_INIT(0xc44d002f, 0x69f9, 0x4e7d,
47 		  0xa9, 0x04, 0xa7, 0xba, 0xab, 0xdf, 0x43, 0xf7),
48 	/* Thunderbolt GUID for WAKE_SUPPORTED: 6c501103-c189-4296-ba72-9bf5a26ebe5d */
49 	GUID_INIT(0x6c501103, 0xc189, 0x4296,
50 		  0xba, 0x72, 0x9b, 0xf5, 0xa2, 0x6e, 0xbe, 0x5d),
51 	/* Storage device needs D3 GUID: 5025030f-842f-4ab4-a561-99a5189762d0 */
52 	GUID_INIT(0x5025030f, 0x842f, 0x4ab4,
53 		  0xa5, 0x61, 0x99, 0xa5, 0x18, 0x97, 0x62, 0xd0),
54 };
55 
56 /* ACPI _DSD data subnodes GUID: dbb8e3e6-5886-4ba6-8795-1319f52a966b */
57 static const guid_t ads_guid =
58 	GUID_INIT(0xdbb8e3e6, 0x5886, 0x4ba6,
59 		  0x87, 0x95, 0x13, 0x19, 0xf5, 0x2a, 0x96, 0x6b);
60 
61 /* ACPI _DSD data buffer GUID: edb12dd0-363d-4085-a3d2-49522ca160c4 */
62 static const guid_t buffer_prop_guid =
63 	GUID_INIT(0xedb12dd0, 0x363d, 0x4085,
64 		  0xa3, 0xd2, 0x49, 0x52, 0x2c, 0xa1, 0x60, 0xc4);
65 
66 static bool acpi_enumerate_nondev_subnodes(acpi_handle scope,
67 					   union acpi_object *desc,
68 					   struct acpi_device_data *data,
69 					   struct fwnode_handle *parent);
70 static bool acpi_extract_properties(acpi_handle handle,
71 				    union acpi_object *desc,
72 				    struct acpi_device_data *data);
73 
74 static bool acpi_nondev_subnode_extract(union acpi_object *desc,
75 					acpi_handle handle,
76 					const union acpi_object *link,
77 					struct list_head *list,
78 					struct fwnode_handle *parent)
79 {
80 	struct acpi_data_node *dn;
81 	bool result;
82 
83 	if (acpi_graph_ignore_port(handle))
84 		return false;
85 
86 	dn = kzalloc(sizeof(*dn), GFP_KERNEL);
87 	if (!dn)
88 		return false;
89 
90 	dn->name = link->package.elements[0].string.pointer;
91 	fwnode_init(&dn->fwnode, &acpi_data_fwnode_ops);
92 	dn->parent = parent;
93 	INIT_LIST_HEAD(&dn->data.properties);
94 	INIT_LIST_HEAD(&dn->data.subnodes);
95 
96 	result = acpi_extract_properties(handle, desc, &dn->data);
97 
98 	if (handle) {
99 		acpi_handle scope;
100 		acpi_status status;
101 
102 		/*
103 		 * The scope for the subnode object lookup is the one of the
104 		 * namespace node (device) containing the object that has
105 		 * returned the package.  That is, it's the scope of that
106 		 * object's parent.
107 		 */
108 		status = acpi_get_parent(handle, &scope);
109 		if (ACPI_SUCCESS(status)
110 		    && acpi_enumerate_nondev_subnodes(scope, desc, &dn->data,
111 						      &dn->fwnode))
112 			result = true;
113 	} else if (acpi_enumerate_nondev_subnodes(NULL, desc, &dn->data,
114 						  &dn->fwnode)) {
115 		result = true;
116 	}
117 
118 	if (result) {
119 		dn->handle = handle;
120 		dn->data.pointer = desc;
121 		list_add_tail(&dn->sibling, list);
122 		return true;
123 	}
124 
125 	kfree(dn);
126 	acpi_handle_debug(handle, "Invalid properties/subnodes data, skipping\n");
127 	return false;
128 }
129 
130 static bool acpi_nondev_subnode_data_ok(acpi_handle handle,
131 					const union acpi_object *link,
132 					struct list_head *list,
133 					struct fwnode_handle *parent)
134 {
135 	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
136 	acpi_status status;
137 
138 	status = acpi_evaluate_object_typed(handle, NULL, NULL, &buf,
139 					    ACPI_TYPE_PACKAGE);
140 	if (ACPI_FAILURE(status))
141 		return false;
142 
143 	if (acpi_nondev_subnode_extract(buf.pointer, handle, link, list,
144 					parent))
145 		return true;
146 
147 	ACPI_FREE(buf.pointer);
148 	return false;
149 }
150 
151 static bool acpi_nondev_subnode_ok(acpi_handle scope,
152 				   const union acpi_object *link,
153 				   struct list_head *list,
154 				   struct fwnode_handle *parent)
155 {
156 	acpi_handle handle;
157 	acpi_status status;
158 
159 	if (!scope)
160 		return false;
161 
162 	status = acpi_get_handle(scope, link->package.elements[1].string.pointer,
163 				 &handle);
164 	if (ACPI_FAILURE(status))
165 		return false;
166 
167 	return acpi_nondev_subnode_data_ok(handle, link, list, parent);
168 }
169 
170 static bool acpi_add_nondev_subnodes(acpi_handle scope,
171 				     union acpi_object *links,
172 				     struct list_head *list,
173 				     struct fwnode_handle *parent)
174 {
175 	bool ret = false;
176 	int i;
177 
178 	for (i = 0; i < links->package.count; i++) {
179 		union acpi_object *link, *desc;
180 		acpi_handle handle;
181 		bool result;
182 
183 		link = &links->package.elements[i];
184 		/* Only two elements allowed. */
185 		if (link->package.count != 2)
186 			continue;
187 
188 		/* The first one must be a string. */
189 		if (link->package.elements[0].type != ACPI_TYPE_STRING)
190 			continue;
191 
192 		/* The second one may be a string, a reference or a package. */
193 		switch (link->package.elements[1].type) {
194 		case ACPI_TYPE_STRING:
195 			result = acpi_nondev_subnode_ok(scope, link, list,
196 							 parent);
197 			break;
198 		case ACPI_TYPE_LOCAL_REFERENCE:
199 			handle = link->package.elements[1].reference.handle;
200 			result = acpi_nondev_subnode_data_ok(handle, link, list,
201 							     parent);
202 			break;
203 		case ACPI_TYPE_PACKAGE:
204 			desc = &link->package.elements[1];
205 			result = acpi_nondev_subnode_extract(desc, NULL, link,
206 							     list, parent);
207 			break;
208 		default:
209 			result = false;
210 			break;
211 		}
212 		ret = ret || result;
213 	}
214 
215 	return ret;
216 }
217 
218 static bool acpi_enumerate_nondev_subnodes(acpi_handle scope,
219 					   union acpi_object *desc,
220 					   struct acpi_device_data *data,
221 					   struct fwnode_handle *parent)
222 {
223 	int i;
224 
225 	/* Look for the ACPI data subnodes GUID. */
226 	for (i = 0; i < desc->package.count; i += 2) {
227 		const union acpi_object *guid;
228 		union acpi_object *links;
229 
230 		guid = &desc->package.elements[i];
231 		links = &desc->package.elements[i + 1];
232 
233 		/*
234 		 * The first element must be a GUID and the second one must be
235 		 * a package.
236 		 */
237 		if (guid->type != ACPI_TYPE_BUFFER ||
238 		    guid->buffer.length != 16 ||
239 		    links->type != ACPI_TYPE_PACKAGE)
240 			break;
241 
242 		if (!guid_equal((guid_t *)guid->buffer.pointer, &ads_guid))
243 			continue;
244 
245 		return acpi_add_nondev_subnodes(scope, links, &data->subnodes,
246 						parent);
247 	}
248 
249 	return false;
250 }
251 
252 static bool acpi_property_value_ok(const union acpi_object *value)
253 {
254 	int j;
255 
256 	/*
257 	 * The value must be an integer, a string, a reference, or a package
258 	 * whose every element must be an integer, a string, or a reference.
259 	 */
260 	switch (value->type) {
261 	case ACPI_TYPE_INTEGER:
262 	case ACPI_TYPE_STRING:
263 	case ACPI_TYPE_LOCAL_REFERENCE:
264 		return true;
265 
266 	case ACPI_TYPE_PACKAGE:
267 		for (j = 0; j < value->package.count; j++)
268 			switch (value->package.elements[j].type) {
269 			case ACPI_TYPE_INTEGER:
270 			case ACPI_TYPE_STRING:
271 			case ACPI_TYPE_LOCAL_REFERENCE:
272 				continue;
273 
274 			default:
275 				return false;
276 			}
277 
278 		return true;
279 	}
280 	return false;
281 }
282 
283 static bool acpi_properties_format_valid(const union acpi_object *properties)
284 {
285 	int i;
286 
287 	for (i = 0; i < properties->package.count; i++) {
288 		const union acpi_object *property;
289 
290 		property = &properties->package.elements[i];
291 		/*
292 		 * Only two elements allowed, the first one must be a string and
293 		 * the second one has to satisfy certain conditions.
294 		 */
295 		if (property->package.count != 2
296 		    || property->package.elements[0].type != ACPI_TYPE_STRING
297 		    || !acpi_property_value_ok(&property->package.elements[1]))
298 			return false;
299 	}
300 	return true;
301 }
302 
303 static void acpi_init_of_compatible(struct acpi_device *adev)
304 {
305 	const union acpi_object *of_compatible;
306 	int ret;
307 
308 	ret = acpi_data_get_property_array(&adev->data, "compatible",
309 					   ACPI_TYPE_STRING, &of_compatible);
310 	if (ret) {
311 		ret = acpi_dev_get_property(adev, "compatible",
312 					    ACPI_TYPE_STRING, &of_compatible);
313 		if (ret) {
314 			struct acpi_device *parent;
315 
316 			parent = acpi_dev_parent(adev);
317 			if (parent && parent->flags.of_compatible_ok)
318 				goto out;
319 
320 			return;
321 		}
322 	}
323 	adev->data.of_compatible = of_compatible;
324 
325  out:
326 	adev->flags.of_compatible_ok = 1;
327 }
328 
329 static bool acpi_is_property_guid(const guid_t *guid)
330 {
331 	int i;
332 
333 	for (i = 0; i < ARRAY_SIZE(prp_guids); i++) {
334 		if (guid_equal(guid, &prp_guids[i]))
335 			return true;
336 	}
337 
338 	return false;
339 }
340 
341 struct acpi_device_properties *
342 acpi_data_add_props(struct acpi_device_data *data, const guid_t *guid,
343 		    union acpi_object *properties)
344 {
345 	struct acpi_device_properties *props;
346 
347 	props = kzalloc(sizeof(*props), GFP_KERNEL);
348 	if (props) {
349 		INIT_LIST_HEAD(&props->list);
350 		props->guid = guid;
351 		props->properties = properties;
352 		list_add_tail(&props->list, &data->properties);
353 	}
354 
355 	return props;
356 }
357 
358 static void acpi_nondev_subnode_tag(acpi_handle handle, void *context)
359 {
360 }
361 
362 static void acpi_untie_nondev_subnodes(struct acpi_device_data *data)
363 {
364 	struct acpi_data_node *dn;
365 
366 	list_for_each_entry(dn, &data->subnodes, sibling) {
367 		acpi_detach_data(dn->handle, acpi_nondev_subnode_tag);
368 
369 		acpi_untie_nondev_subnodes(&dn->data);
370 	}
371 }
372 
373 static bool acpi_tie_nondev_subnodes(struct acpi_device_data *data)
374 {
375 	struct acpi_data_node *dn;
376 
377 	list_for_each_entry(dn, &data->subnodes, sibling) {
378 		acpi_status status;
379 		bool ret;
380 
381 		status = acpi_attach_data(dn->handle, acpi_nondev_subnode_tag, dn);
382 		if (ACPI_FAILURE(status) && status != AE_ALREADY_EXISTS) {
383 			acpi_handle_err(dn->handle, "Can't tag data node\n");
384 			return false;
385 		}
386 
387 		ret = acpi_tie_nondev_subnodes(&dn->data);
388 		if (!ret)
389 			return ret;
390 	}
391 
392 	return true;
393 }
394 
395 static void acpi_data_add_buffer_props(acpi_handle handle,
396 				       struct acpi_device_data *data,
397 				       union acpi_object *properties)
398 {
399 	struct acpi_device_properties *props;
400 	union acpi_object *package;
401 	size_t alloc_size;
402 	unsigned int i;
403 	u32 *count;
404 
405 	if (check_mul_overflow((size_t)properties->package.count,
406 			       sizeof(*package) + sizeof(void *),
407 			       &alloc_size) ||
408 	    check_add_overflow(sizeof(*props) + sizeof(*package), alloc_size,
409 			       &alloc_size)) {
410 		acpi_handle_warn(handle,
411 				 "can't allocate memory for %u buffer props",
412 				 properties->package.count);
413 		return;
414 	}
415 
416 	props = kvzalloc(alloc_size, GFP_KERNEL);
417 	if (!props)
418 		return;
419 
420 	props->guid = &buffer_prop_guid;
421 	props->bufs = (void *)(props + 1);
422 	props->properties = (void *)(props->bufs + properties->package.count);
423 
424 	/* Outer package */
425 	package = props->properties;
426 	package->type = ACPI_TYPE_PACKAGE;
427 	package->package.elements = package + 1;
428 	count = &package->package.count;
429 	*count = 0;
430 
431 	/* Inner packages */
432 	package++;
433 
434 	for (i = 0; i < properties->package.count; i++) {
435 		struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
436 		union acpi_object *property = &properties->package.elements[i];
437 		union acpi_object *prop, *obj, *buf_obj;
438 		acpi_status status;
439 
440 		if (property->type != ACPI_TYPE_PACKAGE ||
441 		    property->package.count != 2) {
442 			acpi_handle_warn(handle,
443 					 "buffer property %u has %u entries\n",
444 					 i, property->package.count);
445 			continue;
446 		}
447 
448 		prop = &property->package.elements[0];
449 		obj = &property->package.elements[1];
450 
451 		if (prop->type != ACPI_TYPE_STRING ||
452 		    obj->type != ACPI_TYPE_STRING) {
453 			acpi_handle_warn(handle,
454 					 "wrong object types %u and %u\n",
455 					 prop->type, obj->type);
456 			continue;
457 		}
458 
459 		status = acpi_evaluate_object_typed(handle, obj->string.pointer,
460 						    NULL, &buf,
461 						    ACPI_TYPE_BUFFER);
462 		if (ACPI_FAILURE(status)) {
463 			acpi_handle_warn(handle,
464 					 "can't evaluate \"%*pE\" as buffer\n",
465 					 obj->string.length,
466 					 obj->string.pointer);
467 			continue;
468 		}
469 
470 		package->type = ACPI_TYPE_PACKAGE;
471 		package->package.elements = prop;
472 		package->package.count = 2;
473 
474 		buf_obj = buf.pointer;
475 
476 		/* Replace the string object with a buffer object */
477 		obj->type = ACPI_TYPE_BUFFER;
478 		obj->buffer.length = buf_obj->buffer.length;
479 		obj->buffer.pointer = buf_obj->buffer.pointer;
480 
481 		props->bufs[i] = buf.pointer;
482 		package++;
483 		(*count)++;
484 	}
485 
486 	if (*count)
487 		list_add(&props->list, &data->properties);
488 	else
489 		kvfree(props);
490 }
491 
492 static bool acpi_extract_properties(acpi_handle scope, union acpi_object *desc,
493 				    struct acpi_device_data *data)
494 {
495 	int i;
496 
497 	if (desc->package.count % 2)
498 		return false;
499 
500 	/* Look for the device properties GUID. */
501 	for (i = 0; i < desc->package.count; i += 2) {
502 		const union acpi_object *guid;
503 		union acpi_object *properties;
504 
505 		guid = &desc->package.elements[i];
506 		properties = &desc->package.elements[i + 1];
507 
508 		/*
509 		 * The first element must be a GUID and the second one must be
510 		 * a package.
511 		 */
512 		if (guid->type != ACPI_TYPE_BUFFER ||
513 		    guid->buffer.length != 16 ||
514 		    properties->type != ACPI_TYPE_PACKAGE)
515 			break;
516 
517 		if (guid_equal((guid_t *)guid->buffer.pointer,
518 			       &buffer_prop_guid)) {
519 			acpi_data_add_buffer_props(scope, data, properties);
520 			continue;
521 		}
522 
523 		if (!acpi_is_property_guid((guid_t *)guid->buffer.pointer))
524 			continue;
525 
526 		/*
527 		 * We found the matching GUID. Now validate the format of the
528 		 * package immediately following it.
529 		 */
530 		if (!acpi_properties_format_valid(properties))
531 			continue;
532 
533 		acpi_data_add_props(data, (const guid_t *)guid->buffer.pointer,
534 				    properties);
535 	}
536 
537 	return !list_empty(&data->properties);
538 }
539 
540 void acpi_init_properties(struct acpi_device *adev)
541 {
542 	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
543 	struct acpi_hardware_id *hwid;
544 	acpi_status status;
545 	bool acpi_of = false;
546 
547 	INIT_LIST_HEAD(&adev->data.properties);
548 	INIT_LIST_HEAD(&adev->data.subnodes);
549 
550 	if (!adev->handle)
551 		return;
552 
553 	/*
554 	 * Check if ACPI_DT_NAMESPACE_HID is present and inthat case we fill in
555 	 * Device Tree compatible properties for this device.
556 	 */
557 	list_for_each_entry(hwid, &adev->pnp.ids, list) {
558 		if (!strcmp(hwid->id, ACPI_DT_NAMESPACE_HID)) {
559 			acpi_of = true;
560 			break;
561 		}
562 	}
563 
564 	status = acpi_evaluate_object_typed(adev->handle, "_DSD", NULL, &buf,
565 					    ACPI_TYPE_PACKAGE);
566 	if (ACPI_FAILURE(status))
567 		goto out;
568 
569 	if (acpi_extract_properties(adev->handle, buf.pointer, &adev->data)) {
570 		adev->data.pointer = buf.pointer;
571 		if (acpi_of)
572 			acpi_init_of_compatible(adev);
573 	}
574 	if (acpi_enumerate_nondev_subnodes(adev->handle, buf.pointer,
575 					&adev->data, acpi_fwnode_handle(adev)))
576 		adev->data.pointer = buf.pointer;
577 
578 	if (!adev->data.pointer) {
579 		acpi_handle_debug(adev->handle, "Invalid _DSD data, skipping\n");
580 		ACPI_FREE(buf.pointer);
581 	} else {
582 		if (!acpi_tie_nondev_subnodes(&adev->data))
583 			acpi_untie_nondev_subnodes(&adev->data);
584 	}
585 
586  out:
587 	if (acpi_of && !adev->flags.of_compatible_ok)
588 		acpi_handle_info(adev->handle,
589 			 ACPI_DT_NAMESPACE_HID " requires 'compatible' property\n");
590 
591 	if (!adev->data.pointer)
592 		acpi_extract_apple_properties(adev);
593 }
594 
595 static void acpi_free_device_properties(struct list_head *list)
596 {
597 	struct acpi_device_properties *props, *tmp;
598 
599 	list_for_each_entry_safe(props, tmp, list, list) {
600 		u32 i;
601 
602 		list_del(&props->list);
603 		/* Buffer data properties were separately allocated */
604 		if (props->bufs)
605 			for (i = 0; i < props->properties->package.count; i++)
606 				ACPI_FREE(props->bufs[i]);
607 		kvfree(props);
608 	}
609 }
610 
611 static void acpi_destroy_nondev_subnodes(struct list_head *list)
612 {
613 	struct acpi_data_node *dn, *next;
614 
615 	if (list_empty(list))
616 		return;
617 
618 	list_for_each_entry_safe_reverse(dn, next, list, sibling) {
619 		acpi_destroy_nondev_subnodes(&dn->data.subnodes);
620 		wait_for_completion(&dn->kobj_done);
621 		list_del(&dn->sibling);
622 		ACPI_FREE((void *)dn->data.pointer);
623 		acpi_free_device_properties(&dn->data.properties);
624 		kfree(dn);
625 	}
626 }
627 
628 void acpi_free_properties(struct acpi_device *adev)
629 {
630 	acpi_untie_nondev_subnodes(&adev->data);
631 	acpi_destroy_nondev_subnodes(&adev->data.subnodes);
632 	ACPI_FREE((void *)adev->data.pointer);
633 	adev->data.of_compatible = NULL;
634 	adev->data.pointer = NULL;
635 	acpi_free_device_properties(&adev->data.properties);
636 }
637 
638 /**
639  * acpi_data_get_property - return an ACPI property with given name
640  * @data: ACPI device deta object to get the property from
641  * @name: Name of the property
642  * @type: Expected property type
643  * @obj: Location to store the property value (if not %NULL)
644  *
645  * Look up a property with @name and store a pointer to the resulting ACPI
646  * object at the location pointed to by @obj if found.
647  *
648  * Callers must not attempt to free the returned objects.  These objects will be
649  * freed by the ACPI core automatically during the removal of @data.
650  *
651  * Return: %0 if property with @name has been found (success),
652  *         %-EINVAL if the arguments are invalid,
653  *         %-EINVAL if the property doesn't exist,
654  *         %-EPROTO if the property value type doesn't match @type.
655  */
656 static int acpi_data_get_property(const struct acpi_device_data *data,
657 				  const char *name, acpi_object_type type,
658 				  const union acpi_object **obj)
659 {
660 	const struct acpi_device_properties *props;
661 
662 	if (!data || !name)
663 		return -EINVAL;
664 
665 	if (!data->pointer || list_empty(&data->properties))
666 		return -EINVAL;
667 
668 	list_for_each_entry(props, &data->properties, list) {
669 		const union acpi_object *properties;
670 		unsigned int i;
671 
672 		properties = props->properties;
673 		for (i = 0; i < properties->package.count; i++) {
674 			const union acpi_object *propname, *propvalue;
675 			const union acpi_object *property;
676 
677 			property = &properties->package.elements[i];
678 
679 			propname = &property->package.elements[0];
680 			propvalue = &property->package.elements[1];
681 
682 			if (!strcmp(name, propname->string.pointer)) {
683 				if (type != ACPI_TYPE_ANY &&
684 				    propvalue->type != type)
685 					return -EPROTO;
686 				if (obj)
687 					*obj = propvalue;
688 
689 				return 0;
690 			}
691 		}
692 	}
693 	return -EINVAL;
694 }
695 
696 /**
697  * acpi_dev_get_property - return an ACPI property with given name.
698  * @adev: ACPI device to get the property from.
699  * @name: Name of the property.
700  * @type: Expected property type.
701  * @obj: Location to store the property value (if not %NULL).
702  */
703 int acpi_dev_get_property(const struct acpi_device *adev, const char *name,
704 			  acpi_object_type type, const union acpi_object **obj)
705 {
706 	return adev ? acpi_data_get_property(&adev->data, name, type, obj) : -EINVAL;
707 }
708 EXPORT_SYMBOL_GPL(acpi_dev_get_property);
709 
710 static const struct acpi_device_data *
711 acpi_device_data_of_node(const struct fwnode_handle *fwnode)
712 {
713 	if (is_acpi_device_node(fwnode)) {
714 		const struct acpi_device *adev = to_acpi_device_node(fwnode);
715 		return &adev->data;
716 	}
717 	if (is_acpi_data_node(fwnode)) {
718 		const struct acpi_data_node *dn = to_acpi_data_node(fwnode);
719 		return &dn->data;
720 	}
721 	return NULL;
722 }
723 
724 /**
725  * acpi_node_prop_get - return an ACPI property with given name.
726  * @fwnode: Firmware node to get the property from.
727  * @propname: Name of the property.
728  * @valptr: Location to store a pointer to the property value (if not %NULL).
729  */
730 int acpi_node_prop_get(const struct fwnode_handle *fwnode,
731 		       const char *propname, void **valptr)
732 {
733 	return acpi_data_get_property(acpi_device_data_of_node(fwnode),
734 				      propname, ACPI_TYPE_ANY,
735 				      (const union acpi_object **)valptr);
736 }
737 
738 /**
739  * acpi_data_get_property_array - return an ACPI array property with given name
740  * @data: ACPI data object to get the property from
741  * @name: Name of the property
742  * @type: Expected type of array elements
743  * @obj: Location to store a pointer to the property value (if not NULL)
744  *
745  * Look up an array property with @name and store a pointer to the resulting
746  * ACPI object at the location pointed to by @obj if found.
747  *
748  * Callers must not attempt to free the returned objects.  Those objects will be
749  * freed by the ACPI core automatically during the removal of @data.
750  *
751  * Return: %0 if array property (package) with @name has been found (success),
752  *         %-EINVAL if the arguments are invalid,
753  *         %-EINVAL if the property doesn't exist,
754  *         %-EPROTO if the property is not a package or the type of its elements
755  *           doesn't match @type.
756  */
757 static int acpi_data_get_property_array(const struct acpi_device_data *data,
758 					const char *name,
759 					acpi_object_type type,
760 					const union acpi_object **obj)
761 {
762 	const union acpi_object *prop;
763 	int ret, i;
764 
765 	ret = acpi_data_get_property(data, name, ACPI_TYPE_PACKAGE, &prop);
766 	if (ret)
767 		return ret;
768 
769 	if (type != ACPI_TYPE_ANY) {
770 		/* Check that all elements are of correct type. */
771 		for (i = 0; i < prop->package.count; i++)
772 			if (prop->package.elements[i].type != type)
773 				return -EPROTO;
774 	}
775 	if (obj)
776 		*obj = prop;
777 
778 	return 0;
779 }
780 
781 static struct fwnode_handle *
782 acpi_fwnode_get_named_child_node(const struct fwnode_handle *fwnode,
783 				 const char *childname)
784 {
785 	struct fwnode_handle *child;
786 
787 	fwnode_for_each_child_node(fwnode, child) {
788 		if (is_acpi_data_node(child)) {
789 			if (acpi_data_node_match(child, childname))
790 				return child;
791 			continue;
792 		}
793 
794 		if (!strncmp(acpi_device_bid(to_acpi_device_node(child)),
795 			     childname, ACPI_NAMESEG_SIZE))
796 			return child;
797 	}
798 
799 	return NULL;
800 }
801 
802 static int acpi_get_ref_args(struct fwnode_reference_args *args,
803 			     struct fwnode_handle *ref_fwnode,
804 			     const union acpi_object **element,
805 			     const union acpi_object *end, size_t num_args)
806 {
807 	u32 nargs = 0, i;
808 
809 	/*
810 	 * Assume the following integer elements are all args. Stop counting on
811 	 * the first reference (possibly represented as a string) or end of the
812 	 * package arguments. In case of neither reference, nor integer, return
813 	 * an error, we can't parse it.
814 	 */
815 	for (i = 0; (*element) + i < end && i < num_args; i++) {
816 		acpi_object_type type = (*element)[i].type;
817 
818 		if (type == ACPI_TYPE_LOCAL_REFERENCE || type == ACPI_TYPE_STRING)
819 			break;
820 
821 		if (type == ACPI_TYPE_INTEGER)
822 			nargs++;
823 		else
824 			return -EINVAL;
825 	}
826 
827 	if (nargs > NR_FWNODE_REFERENCE_ARGS)
828 		return -EINVAL;
829 
830 	if (args) {
831 		args->fwnode = ref_fwnode;
832 		args->nargs = nargs;
833 		for (i = 0; i < nargs; i++)
834 			args->args[i] = (*element)[i].integer.value;
835 	}
836 
837 	(*element) += nargs;
838 
839 	return 0;
840 }
841 
842 static struct fwnode_handle *acpi_parse_string_ref(const struct fwnode_handle *fwnode,
843 						   const char *refstring)
844 {
845 	acpi_handle scope, handle;
846 	struct acpi_data_node *dn;
847 	struct acpi_device *device;
848 	acpi_status status;
849 
850 	if (is_acpi_device_node(fwnode)) {
851 		scope = to_acpi_device_node(fwnode)->handle;
852 	} else if (is_acpi_data_node(fwnode)) {
853 		scope = to_acpi_data_node(fwnode)->handle;
854 	} else {
855 		pr_debug("Bad node type for node %pfw\n", fwnode);
856 		return NULL;
857 	}
858 
859 	status = acpi_get_handle(scope, refstring, &handle);
860 	if (ACPI_FAILURE(status)) {
861 		acpi_handle_debug(scope, "Unable to get an ACPI handle for %s\n",
862 				  refstring);
863 		return NULL;
864 	}
865 
866 	device = acpi_fetch_acpi_dev(handle);
867 	if (device)
868 		return acpi_fwnode_handle(device);
869 
870 	status = acpi_get_data_full(handle, acpi_nondev_subnode_tag,
871 				    (void **)&dn, NULL);
872 	if (ACPI_FAILURE(status) || !dn) {
873 		acpi_handle_debug(handle, "Subnode not found\n");
874 		return NULL;
875 	}
876 
877 	return &dn->fwnode;
878 }
879 
880 /**
881  * __acpi_node_get_property_reference - returns handle to the referenced object
882  * @fwnode: Firmware node to get the property from
883  * @propname: Name of the property
884  * @index: Index of the reference to return
885  * @num_args: Maximum number of arguments after each reference
886  * @args: Location to store the returned reference with optional arguments
887  *	  (may be NULL)
888  *
889  * Find property with @name, verifify that it is a package containing at least
890  * one object reference and if so, store the ACPI device object pointer to the
891  * target object in @args->adev.  If the reference includes arguments, store
892  * them in the @args->args[] array.
893  *
894  * If there's more than one reference in the property value package, @index is
895  * used to select the one to return.
896  *
897  * It is possible to leave holes in the property value set like in the
898  * example below:
899  *
900  * Package () {
901  *     "cs-gpios",
902  *     Package () {
903  *        ^GPIO, 19, 0, 0,
904  *        ^GPIO, 20, 0, 0,
905  *        0,
906  *        ^GPIO, 21, 0, 0,
907  *     }
908  * }
909  *
910  * Calling this function with index %2 or index %3 return %-ENOENT. If the
911  * property does not contain any more values %-ENOENT is returned. The NULL
912  * entry must be single integer and preferably contain value %0.
913  *
914  * Return: %0 on success, negative error code on failure.
915  */
916 int __acpi_node_get_property_reference(const struct fwnode_handle *fwnode,
917 	const char *propname, size_t index, size_t num_args,
918 	struct fwnode_reference_args *args)
919 {
920 	const union acpi_object *element, *end;
921 	const union acpi_object *obj;
922 	const struct acpi_device_data *data;
923 	struct fwnode_handle *ref_fwnode;
924 	struct acpi_device *device;
925 	int ret, idx = 0;
926 
927 	data = acpi_device_data_of_node(fwnode);
928 	if (!data)
929 		return -ENOENT;
930 
931 	ret = acpi_data_get_property(data, propname, ACPI_TYPE_ANY, &obj);
932 	if (ret)
933 		return ret == -EINVAL ? -ENOENT : -EINVAL;
934 
935 	switch (obj->type) {
936 	case ACPI_TYPE_LOCAL_REFERENCE:
937 		/* Plain single reference without arguments. */
938 		if (index)
939 			return -ENOENT;
940 
941 		device = acpi_fetch_acpi_dev(obj->reference.handle);
942 		if (!device)
943 			return -EINVAL;
944 
945 		if (!args)
946 			return 0;
947 
948 		args->fwnode = acpi_fwnode_handle(device);
949 		args->nargs = 0;
950 
951 		return 0;
952 	case ACPI_TYPE_STRING:
953 		if (index)
954 			return -ENOENT;
955 
956 		ref_fwnode = acpi_parse_string_ref(fwnode, obj->string.pointer);
957 		if (!ref_fwnode)
958 			return -EINVAL;
959 
960 		args->fwnode = ref_fwnode;
961 		args->nargs = 0;
962 
963 		return 0;
964 	case ACPI_TYPE_PACKAGE:
965 		/*
966 		 * If it is not a single reference, then it is a package of
967 		 * references, followed by number of ints as follows:
968 		 *
969 		 *  Package () { REF, INT, REF, INT, INT }
970 		 *
971 		 * Here, REF may be either a local reference or a string. The
972 		 * index argument is then used to determine which reference the
973 		 * caller wants (along with the arguments).
974 		 */
975 		break;
976 	default:
977 		return -EINVAL;
978 	}
979 
980 	if (index >= obj->package.count)
981 		return -ENOENT;
982 
983 	element = obj->package.elements;
984 	end = element + obj->package.count;
985 
986 	while (element < end) {
987 		switch (element->type) {
988 		case ACPI_TYPE_LOCAL_REFERENCE:
989 			device = acpi_fetch_acpi_dev(element->reference.handle);
990 			if (!device)
991 				return -EINVAL;
992 
993 			element++;
994 
995 			ret = acpi_get_ref_args(idx == index ? args : NULL,
996 						acpi_fwnode_handle(device),
997 						&element, end, num_args);
998 			if (ret < 0)
999 				return ret;
1000 
1001 			if (idx == index)
1002 				return 0;
1003 
1004 			break;
1005 		case ACPI_TYPE_STRING:
1006 			ref_fwnode = acpi_parse_string_ref(fwnode,
1007 							   element->string.pointer);
1008 			if (!ref_fwnode)
1009 				return -EINVAL;
1010 
1011 			element++;
1012 
1013 			ret = acpi_get_ref_args(idx == index ? args : NULL,
1014 						ref_fwnode, &element, end,
1015 						num_args);
1016 			if (ret < 0)
1017 				return ret;
1018 
1019 			if (idx == index)
1020 				return 0;
1021 
1022 			break;
1023 		case ACPI_TYPE_INTEGER:
1024 			if (idx == index)
1025 				return -ENOENT;
1026 			element++;
1027 			break;
1028 		default:
1029 			return -EINVAL;
1030 		}
1031 
1032 		idx++;
1033 	}
1034 
1035 	return -ENOENT;
1036 }
1037 EXPORT_SYMBOL_GPL(__acpi_node_get_property_reference);
1038 
1039 static int acpi_data_prop_read_single(const struct acpi_device_data *data,
1040 				      const char *propname,
1041 				      enum dev_prop_type proptype, void *val)
1042 {
1043 	const union acpi_object *obj;
1044 	int ret = 0;
1045 
1046 	if (proptype >= DEV_PROP_U8 && proptype <= DEV_PROP_U64)
1047 		ret = acpi_data_get_property(data, propname, ACPI_TYPE_INTEGER, &obj);
1048 	else if (proptype == DEV_PROP_STRING)
1049 		ret = acpi_data_get_property(data, propname, ACPI_TYPE_STRING, &obj);
1050 	if (ret)
1051 		return ret;
1052 
1053 	switch (proptype) {
1054 	case DEV_PROP_U8:
1055 		if (obj->integer.value > U8_MAX)
1056 			return -EOVERFLOW;
1057 		if (val)
1058 			*(u8 *)val = obj->integer.value;
1059 		break;
1060 	case DEV_PROP_U16:
1061 		if (obj->integer.value > U16_MAX)
1062 			return -EOVERFLOW;
1063 		if (val)
1064 			*(u16 *)val = obj->integer.value;
1065 		break;
1066 	case DEV_PROP_U32:
1067 		if (obj->integer.value > U32_MAX)
1068 			return -EOVERFLOW;
1069 		if (val)
1070 			*(u32 *)val = obj->integer.value;
1071 		break;
1072 	case DEV_PROP_U64:
1073 		if (val)
1074 			*(u64 *)val = obj->integer.value;
1075 		break;
1076 	case DEV_PROP_STRING:
1077 		if (val)
1078 			*(char **)val = obj->string.pointer;
1079 		return 1;
1080 	default:
1081 		return -EINVAL;
1082 	}
1083 
1084 	/* When no storage provided return number of available values */
1085 	return val ? 0 : 1;
1086 }
1087 
1088 #define acpi_copy_property_array_uint(items, val, nval)			\
1089 	({								\
1090 		typeof(items) __items = items;				\
1091 		typeof(val) __val = val;				\
1092 		typeof(nval) __nval = nval;				\
1093 		size_t i;						\
1094 		int ret = 0;						\
1095 									\
1096 		for (i = 0; i < __nval; i++) {				\
1097 			if (__items->type == ACPI_TYPE_BUFFER) {	\
1098 				__val[i] = __items->buffer.pointer[i];	\
1099 				continue;				\
1100 			}						\
1101 			if (__items[i].type != ACPI_TYPE_INTEGER) {	\
1102 				ret = -EPROTO;				\
1103 				break;					\
1104 			}						\
1105 			if (__items[i].integer.value > _Generic(__val,	\
1106 								u8 *: U8_MAX, \
1107 								u16 *: U16_MAX, \
1108 								u32 *: U32_MAX, \
1109 								u64 *: U64_MAX)) { \
1110 				ret = -EOVERFLOW;			\
1111 				break;					\
1112 			}						\
1113 									\
1114 			__val[i] = __items[i].integer.value;		\
1115 		}							\
1116 		ret;							\
1117 	})
1118 
1119 static int acpi_copy_property_array_string(const union acpi_object *items,
1120 					   char **val, size_t nval)
1121 {
1122 	int i;
1123 
1124 	for (i = 0; i < nval; i++) {
1125 		if (items[i].type != ACPI_TYPE_STRING)
1126 			return -EPROTO;
1127 
1128 		val[i] = items[i].string.pointer;
1129 	}
1130 	return nval;
1131 }
1132 
1133 static int acpi_data_prop_read(const struct acpi_device_data *data,
1134 			       const char *propname,
1135 			       enum dev_prop_type proptype,
1136 			       void *val, size_t nval)
1137 {
1138 	const union acpi_object *obj;
1139 	const union acpi_object *items;
1140 	int ret;
1141 
1142 	if (nval == 1 || !val) {
1143 		ret = acpi_data_prop_read_single(data, propname, proptype, val);
1144 		/*
1145 		 * The overflow error means that the property is there and it is
1146 		 * single-value, but its type does not match, so return.
1147 		 */
1148 		if (ret >= 0 || ret == -EOVERFLOW)
1149 			return ret;
1150 
1151 		/*
1152 		 * Reading this property as a single-value one failed, but its
1153 		 * value may still be represented as one-element array, so
1154 		 * continue.
1155 		 */
1156 	}
1157 
1158 	ret = acpi_data_get_property_array(data, propname, ACPI_TYPE_ANY, &obj);
1159 	if (ret && proptype >= DEV_PROP_U8 && proptype <= DEV_PROP_U64)
1160 		ret = acpi_data_get_property(data, propname, ACPI_TYPE_BUFFER,
1161 					     &obj);
1162 	if (ret)
1163 		return ret;
1164 
1165 	if (!val) {
1166 		if (obj->type == ACPI_TYPE_BUFFER)
1167 			return obj->buffer.length;
1168 
1169 		return obj->package.count;
1170 	}
1171 
1172 	switch (proptype) {
1173 	case DEV_PROP_STRING:
1174 		break;
1175 	default:
1176 		if (obj->type == ACPI_TYPE_BUFFER) {
1177 			if (nval > obj->buffer.length)
1178 				return -EOVERFLOW;
1179 		} else {
1180 			if (nval > obj->package.count)
1181 				return -EOVERFLOW;
1182 		}
1183 		break;
1184 	}
1185 	if (nval == 0)
1186 		return -EINVAL;
1187 
1188 	if (obj->type == ACPI_TYPE_BUFFER) {
1189 		if (proptype != DEV_PROP_U8)
1190 			return -EPROTO;
1191 		items = obj;
1192 	} else {
1193 		items = obj->package.elements;
1194 	}
1195 
1196 	switch (proptype) {
1197 	case DEV_PROP_U8:
1198 		ret = acpi_copy_property_array_uint(items, (u8 *)val, nval);
1199 		break;
1200 	case DEV_PROP_U16:
1201 		ret = acpi_copy_property_array_uint(items, (u16 *)val, nval);
1202 		break;
1203 	case DEV_PROP_U32:
1204 		ret = acpi_copy_property_array_uint(items, (u32 *)val, nval);
1205 		break;
1206 	case DEV_PROP_U64:
1207 		ret = acpi_copy_property_array_uint(items, (u64 *)val, nval);
1208 		break;
1209 	case DEV_PROP_STRING:
1210 		ret = acpi_copy_property_array_string(
1211 			items, (char **)val,
1212 			min_t(u32, nval, obj->package.count));
1213 		break;
1214 	default:
1215 		ret = -EINVAL;
1216 		break;
1217 	}
1218 	return ret;
1219 }
1220 
1221 /**
1222  * acpi_node_prop_read - retrieve the value of an ACPI property with given name.
1223  * @fwnode: Firmware node to get the property from.
1224  * @propname: Name of the property.
1225  * @proptype: Expected property type.
1226  * @val: Location to store the property value (if not %NULL).
1227  * @nval: Size of the array pointed to by @val.
1228  *
1229  * If @val is %NULL, return the number of array elements comprising the value
1230  * of the property.  Otherwise, read at most @nval values to the array at the
1231  * location pointed to by @val.
1232  */
1233 static int acpi_node_prop_read(const struct fwnode_handle *fwnode,
1234 			       const char *propname, enum dev_prop_type proptype,
1235 			       void *val, size_t nval)
1236 {
1237 	return acpi_data_prop_read(acpi_device_data_of_node(fwnode),
1238 				   propname, proptype, val, nval);
1239 }
1240 
1241 static int stop_on_next(struct acpi_device *adev, void *data)
1242 {
1243 	struct acpi_device **ret_p = data;
1244 
1245 	if (!*ret_p) {
1246 		*ret_p = adev;
1247 		return 1;
1248 	}
1249 
1250 	/* Skip until the "previous" object is found. */
1251 	if (*ret_p == adev)
1252 		*ret_p = NULL;
1253 
1254 	return 0;
1255 }
1256 
1257 /**
1258  * acpi_get_next_subnode - Return the next child node handle for a fwnode
1259  * @fwnode: Firmware node to find the next child node for.
1260  * @child: Handle to one of the device's child nodes or a null handle.
1261  */
1262 struct fwnode_handle *acpi_get_next_subnode(const struct fwnode_handle *fwnode,
1263 					    struct fwnode_handle *child)
1264 {
1265 	struct acpi_device *adev = to_acpi_device_node(fwnode);
1266 
1267 	if ((!child || is_acpi_device_node(child)) && adev) {
1268 		struct acpi_device *child_adev = to_acpi_device_node(child);
1269 
1270 		acpi_dev_for_each_child(adev, stop_on_next, &child_adev);
1271 		if (child_adev)
1272 			return acpi_fwnode_handle(child_adev);
1273 
1274 		child = NULL;
1275 	}
1276 
1277 	if (!child || is_acpi_data_node(child)) {
1278 		const struct acpi_data_node *data = to_acpi_data_node(fwnode);
1279 		const struct list_head *head;
1280 		struct list_head *next;
1281 		struct acpi_data_node *dn;
1282 
1283 		/*
1284 		 * We can have a combination of device and data nodes, e.g. with
1285 		 * hierarchical _DSD properties. Make sure the adev pointer is
1286 		 * restored before going through data nodes, otherwise we will
1287 		 * be looking for data_nodes below the last device found instead
1288 		 * of the common fwnode shared by device_nodes and data_nodes.
1289 		 */
1290 		adev = to_acpi_device_node(fwnode);
1291 		if (adev)
1292 			head = &adev->data.subnodes;
1293 		else if (data)
1294 			head = &data->data.subnodes;
1295 		else
1296 			return NULL;
1297 
1298 		if (list_empty(head))
1299 			return NULL;
1300 
1301 		if (child) {
1302 			dn = to_acpi_data_node(child);
1303 			next = dn->sibling.next;
1304 			if (next == head)
1305 				return NULL;
1306 
1307 			dn = list_entry(next, struct acpi_data_node, sibling);
1308 		} else {
1309 			dn = list_first_entry(head, struct acpi_data_node, sibling);
1310 		}
1311 		return &dn->fwnode;
1312 	}
1313 	return NULL;
1314 }
1315 
1316 /**
1317  * acpi_node_get_parent - Return parent fwnode of this fwnode
1318  * @fwnode: Firmware node whose parent to get
1319  *
1320  * Returns parent node of an ACPI device or data firmware node or %NULL if
1321  * not available.
1322  */
1323 static struct fwnode_handle *
1324 acpi_node_get_parent(const struct fwnode_handle *fwnode)
1325 {
1326 	if (is_acpi_data_node(fwnode)) {
1327 		/* All data nodes have parent pointer so just return that */
1328 		return to_acpi_data_node(fwnode)->parent;
1329 	}
1330 	if (is_acpi_device_node(fwnode)) {
1331 		struct acpi_device *parent;
1332 
1333 		parent = acpi_dev_parent(to_acpi_device_node(fwnode));
1334 		if (parent)
1335 			return acpi_fwnode_handle(parent);
1336 	}
1337 
1338 	return NULL;
1339 }
1340 
1341 /*
1342  * Return true if the node is an ACPI graph node. Called on either ports
1343  * or endpoints.
1344  */
1345 static bool is_acpi_graph_node(struct fwnode_handle *fwnode,
1346 			       const char *str)
1347 {
1348 	unsigned int len = strlen(str);
1349 	const char *name;
1350 
1351 	if (!len || !is_acpi_data_node(fwnode))
1352 		return false;
1353 
1354 	name = to_acpi_data_node(fwnode)->name;
1355 
1356 	return (fwnode_property_present(fwnode, "reg") &&
1357 		!strncmp(name, str, len) && name[len] == '@') ||
1358 		fwnode_property_present(fwnode, str);
1359 }
1360 
1361 /**
1362  * acpi_graph_get_next_endpoint - Get next endpoint ACPI firmware node
1363  * @fwnode: Pointer to the parent firmware node
1364  * @prev: Previous endpoint node or %NULL to get the first
1365  *
1366  * Looks up next endpoint ACPI firmware node below a given @fwnode. Returns
1367  * %NULL if there is no next endpoint or in case of error. In case of success
1368  * the next endpoint is returned.
1369  */
1370 static struct fwnode_handle *acpi_graph_get_next_endpoint(
1371 	const struct fwnode_handle *fwnode, struct fwnode_handle *prev)
1372 {
1373 	struct fwnode_handle *port = NULL;
1374 	struct fwnode_handle *endpoint;
1375 
1376 	if (!prev) {
1377 		do {
1378 			port = fwnode_get_next_child_node(fwnode, port);
1379 			/*
1380 			 * The names of the port nodes begin with "port@"
1381 			 * followed by the number of the port node and they also
1382 			 * have a "reg" property that also has the number of the
1383 			 * port node. For compatibility reasons a node is also
1384 			 * recognised as a port node from the "port" property.
1385 			 */
1386 			if (is_acpi_graph_node(port, "port"))
1387 				break;
1388 		} while (port);
1389 	} else {
1390 		port = fwnode_get_parent(prev);
1391 	}
1392 
1393 	if (!port)
1394 		return NULL;
1395 
1396 	endpoint = fwnode_get_next_child_node(port, prev);
1397 	while (!endpoint) {
1398 		port = fwnode_get_next_child_node(fwnode, port);
1399 		if (!port)
1400 			break;
1401 		if (is_acpi_graph_node(port, "port"))
1402 			endpoint = fwnode_get_next_child_node(port, NULL);
1403 	}
1404 
1405 	/*
1406 	 * The names of the endpoint nodes begin with "endpoint@" followed by
1407 	 * the number of the endpoint node and they also have a "reg" property
1408 	 * that also has the number of the endpoint node. For compatibility
1409 	 * reasons a node is also recognised as an endpoint node from the
1410 	 * "endpoint" property.
1411 	 */
1412 	if (!is_acpi_graph_node(endpoint, "endpoint"))
1413 		return NULL;
1414 
1415 	return endpoint;
1416 }
1417 
1418 /**
1419  * acpi_graph_get_child_prop_value - Return a child with a given property value
1420  * @fwnode: device fwnode
1421  * @prop_name: The name of the property to look for
1422  * @val: the desired property value
1423  *
1424  * Return the port node corresponding to a given port number. Returns
1425  * the child node on success, NULL otherwise.
1426  */
1427 static struct fwnode_handle *acpi_graph_get_child_prop_value(
1428 	const struct fwnode_handle *fwnode, const char *prop_name,
1429 	unsigned int val)
1430 {
1431 	struct fwnode_handle *child;
1432 
1433 	fwnode_for_each_child_node(fwnode, child) {
1434 		u32 nr;
1435 
1436 		if (fwnode_property_read_u32(child, prop_name, &nr))
1437 			continue;
1438 
1439 		if (val == nr)
1440 			return child;
1441 	}
1442 
1443 	return NULL;
1444 }
1445 
1446 
1447 /**
1448  * acpi_graph_get_remote_endpoint - Parses and returns remote end of an endpoint
1449  * @__fwnode: Endpoint firmware node pointing to a remote device
1450  *
1451  * Returns the remote endpoint corresponding to @__fwnode. NULL on error.
1452  */
1453 static struct fwnode_handle *
1454 acpi_graph_get_remote_endpoint(const struct fwnode_handle *__fwnode)
1455 {
1456 	struct fwnode_handle *fwnode;
1457 	unsigned int port_nr, endpoint_nr;
1458 	struct fwnode_reference_args args;
1459 	int ret;
1460 
1461 	memset(&args, 0, sizeof(args));
1462 	ret = acpi_node_get_property_reference(__fwnode, "remote-endpoint", 0,
1463 					       &args);
1464 	if (ret)
1465 		return NULL;
1466 
1467 	/* Direct endpoint reference? */
1468 	if (!is_acpi_device_node(args.fwnode))
1469 		return args.nargs ? NULL : args.fwnode;
1470 
1471 	/*
1472 	 * Always require two arguments with the reference: port and
1473 	 * endpoint indices.
1474 	 */
1475 	if (args.nargs != 2)
1476 		return NULL;
1477 
1478 	fwnode = args.fwnode;
1479 	port_nr = args.args[0];
1480 	endpoint_nr = args.args[1];
1481 
1482 	fwnode = acpi_graph_get_child_prop_value(fwnode, "port", port_nr);
1483 
1484 	return acpi_graph_get_child_prop_value(fwnode, "endpoint", endpoint_nr);
1485 }
1486 
1487 static bool acpi_fwnode_device_is_available(const struct fwnode_handle *fwnode)
1488 {
1489 	if (!is_acpi_device_node(fwnode))
1490 		return false;
1491 
1492 	return acpi_device_is_present(to_acpi_device_node(fwnode));
1493 }
1494 
1495 static const void *
1496 acpi_fwnode_device_get_match_data(const struct fwnode_handle *fwnode,
1497 				  const struct device *dev)
1498 {
1499 	return acpi_device_get_match_data(dev);
1500 }
1501 
1502 static bool acpi_fwnode_device_dma_supported(const struct fwnode_handle *fwnode)
1503 {
1504 	return acpi_dma_supported(to_acpi_device_node(fwnode));
1505 }
1506 
1507 static enum dev_dma_attr
1508 acpi_fwnode_device_get_dma_attr(const struct fwnode_handle *fwnode)
1509 {
1510 	return acpi_get_dma_attr(to_acpi_device_node(fwnode));
1511 }
1512 
1513 static bool acpi_fwnode_property_present(const struct fwnode_handle *fwnode,
1514 					 const char *propname)
1515 {
1516 	return !acpi_node_prop_get(fwnode, propname, NULL);
1517 }
1518 
1519 static int
1520 acpi_fwnode_property_read_int_array(const struct fwnode_handle *fwnode,
1521 				    const char *propname,
1522 				    unsigned int elem_size, void *val,
1523 				    size_t nval)
1524 {
1525 	enum dev_prop_type type;
1526 
1527 	switch (elem_size) {
1528 	case sizeof(u8):
1529 		type = DEV_PROP_U8;
1530 		break;
1531 	case sizeof(u16):
1532 		type = DEV_PROP_U16;
1533 		break;
1534 	case sizeof(u32):
1535 		type = DEV_PROP_U32;
1536 		break;
1537 	case sizeof(u64):
1538 		type = DEV_PROP_U64;
1539 		break;
1540 	default:
1541 		return -ENXIO;
1542 	}
1543 
1544 	return acpi_node_prop_read(fwnode, propname, type, val, nval);
1545 }
1546 
1547 static int
1548 acpi_fwnode_property_read_string_array(const struct fwnode_handle *fwnode,
1549 				       const char *propname, const char **val,
1550 				       size_t nval)
1551 {
1552 	return acpi_node_prop_read(fwnode, propname, DEV_PROP_STRING,
1553 				   val, nval);
1554 }
1555 
1556 static int
1557 acpi_fwnode_get_reference_args(const struct fwnode_handle *fwnode,
1558 			       const char *prop, const char *nargs_prop,
1559 			       unsigned int args_count, unsigned int index,
1560 			       struct fwnode_reference_args *args)
1561 {
1562 	return __acpi_node_get_property_reference(fwnode, prop, index,
1563 						  args_count, args);
1564 }
1565 
1566 static const char *acpi_fwnode_get_name(const struct fwnode_handle *fwnode)
1567 {
1568 	const struct acpi_device *adev;
1569 	struct fwnode_handle *parent;
1570 
1571 	/* Is this the root node? */
1572 	parent = fwnode_get_parent(fwnode);
1573 	if (!parent)
1574 		return "\\";
1575 
1576 	fwnode_handle_put(parent);
1577 
1578 	if (is_acpi_data_node(fwnode)) {
1579 		const struct acpi_data_node *dn = to_acpi_data_node(fwnode);
1580 
1581 		return dn->name;
1582 	}
1583 
1584 	adev = to_acpi_device_node(fwnode);
1585 	if (WARN_ON(!adev))
1586 		return NULL;
1587 
1588 	return acpi_device_bid(adev);
1589 }
1590 
1591 static const char *
1592 acpi_fwnode_get_name_prefix(const struct fwnode_handle *fwnode)
1593 {
1594 	struct fwnode_handle *parent;
1595 
1596 	/* Is this the root node? */
1597 	parent = fwnode_get_parent(fwnode);
1598 	if (!parent)
1599 		return "";
1600 
1601 	/* Is this 2nd node from the root? */
1602 	parent = fwnode_get_next_parent(parent);
1603 	if (!parent)
1604 		return "";
1605 
1606 	fwnode_handle_put(parent);
1607 
1608 	/* ACPI device or data node. */
1609 	return ".";
1610 }
1611 
1612 static struct fwnode_handle *
1613 acpi_fwnode_get_parent(struct fwnode_handle *fwnode)
1614 {
1615 	return acpi_node_get_parent(fwnode);
1616 }
1617 
1618 static int acpi_fwnode_graph_parse_endpoint(const struct fwnode_handle *fwnode,
1619 					    struct fwnode_endpoint *endpoint)
1620 {
1621 	struct fwnode_handle *port_fwnode = fwnode_get_parent(fwnode);
1622 
1623 	endpoint->local_fwnode = fwnode;
1624 
1625 	if (fwnode_property_read_u32(port_fwnode, "reg", &endpoint->port))
1626 		fwnode_property_read_u32(port_fwnode, "port", &endpoint->port);
1627 	if (fwnode_property_read_u32(fwnode, "reg", &endpoint->id))
1628 		fwnode_property_read_u32(fwnode, "endpoint", &endpoint->id);
1629 
1630 	return 0;
1631 }
1632 
1633 static int acpi_fwnode_irq_get(const struct fwnode_handle *fwnode,
1634 			       unsigned int index)
1635 {
1636 	struct resource res;
1637 	int ret;
1638 
1639 	ret = acpi_irq_get(ACPI_HANDLE_FWNODE(fwnode), index, &res);
1640 	if (ret)
1641 		return ret;
1642 
1643 	return res.start;
1644 }
1645 
1646 #define DECLARE_ACPI_FWNODE_OPS(ops) \
1647 	const struct fwnode_operations ops = {				\
1648 		.device_is_available = acpi_fwnode_device_is_available, \
1649 		.device_get_match_data = acpi_fwnode_device_get_match_data, \
1650 		.device_dma_supported =				\
1651 			acpi_fwnode_device_dma_supported,		\
1652 		.device_get_dma_attr = acpi_fwnode_device_get_dma_attr,	\
1653 		.property_present = acpi_fwnode_property_present,	\
1654 		.property_read_int_array =				\
1655 			acpi_fwnode_property_read_int_array,		\
1656 		.property_read_string_array =				\
1657 			acpi_fwnode_property_read_string_array,		\
1658 		.get_parent = acpi_node_get_parent,			\
1659 		.get_next_child_node = acpi_get_next_subnode,		\
1660 		.get_named_child_node = acpi_fwnode_get_named_child_node, \
1661 		.get_name = acpi_fwnode_get_name,			\
1662 		.get_name_prefix = acpi_fwnode_get_name_prefix,		\
1663 		.get_reference_args = acpi_fwnode_get_reference_args,	\
1664 		.graph_get_next_endpoint =				\
1665 			acpi_graph_get_next_endpoint,			\
1666 		.graph_get_remote_endpoint =				\
1667 			acpi_graph_get_remote_endpoint,			\
1668 		.graph_get_port_parent = acpi_fwnode_get_parent,	\
1669 		.graph_parse_endpoint = acpi_fwnode_graph_parse_endpoint, \
1670 		.irq_get = acpi_fwnode_irq_get,				\
1671 	};								\
1672 	EXPORT_SYMBOL_GPL(ops)
1673 
1674 DECLARE_ACPI_FWNODE_OPS(acpi_device_fwnode_ops);
1675 DECLARE_ACPI_FWNODE_OPS(acpi_data_fwnode_ops);
1676 const struct fwnode_operations acpi_static_fwnode_ops;
1677 
1678 bool is_acpi_device_node(const struct fwnode_handle *fwnode)
1679 {
1680 	return !IS_ERR_OR_NULL(fwnode) &&
1681 		fwnode->ops == &acpi_device_fwnode_ops;
1682 }
1683 EXPORT_SYMBOL(is_acpi_device_node);
1684 
1685 bool is_acpi_data_node(const struct fwnode_handle *fwnode)
1686 {
1687 	return !IS_ERR_OR_NULL(fwnode) && fwnode->ops == &acpi_data_fwnode_ops;
1688 }
1689 EXPORT_SYMBOL(is_acpi_data_node);
1690