1/*
2 * acpi_utils.c - ACPI Utility Functions ($Revision: 10 $)
3 *
4 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6 *
7 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or (at
12 * your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
18 *
19 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
20 */
21
22#include <linux/kernel.h>
23#include <linux/module.h>
24#include <linux/slab.h>
25#include <linux/init.h>
26#include <linux/types.h>
27#include <linux/hardirq.h>
28#include <linux/acpi.h>
29#include <linux/dynamic_debug.h>
30
31#include "internal.h"
32#include "sleep.h"
33
34#define _COMPONENT ACPI_BUS_COMPONENT
35ACPI_MODULE_NAME("utils");
36
37/* --------------------------------------------------------------------------
38 Object Evaluation Helpers
39 -------------------------------------------------------------------------- */
40static void
41acpi_util_eval_error(acpi_handle h, acpi_string p, acpi_status s)
42{
43#ifdef ACPI_DEBUG_OUTPUT
44 char prefix[80] = {'\0'};
45 struct acpi_buffer buffer = {sizeof(prefix), prefix};
46 acpi_get_name(h, ACPI_FULL_PATHNAME, &buffer);
47 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Evaluate [%s.%s]: %s\n",
48 (char *) prefix, p, acpi_format_exception(s)));
49#else
50 return;
51#endif
52}
53
54acpi_status
55acpi_extract_package(union acpi_object *package,
56 struct acpi_buffer *format, struct acpi_buffer *buffer)
57{
58 u32 size_required = 0;
59 u32 tail_offset = 0;
60 char *format_string = NULL;
61 u32 format_count = 0;
62 u32 i = 0;
63 u8 *head = NULL;
64 u8 *tail = NULL;
65
66
67 if (!package || (package->type != ACPI_TYPE_PACKAGE)
68 || (package->package.count < 1)) {
69 printk(KERN_WARNING PREFIX "Invalid package argument\n");
70 return AE_BAD_PARAMETER;
71 }
72
73 if (!format || !format->pointer || (format->length < 1)) {
74 printk(KERN_WARNING PREFIX "Invalid format argument\n");
75 return AE_BAD_PARAMETER;
76 }
77
78 if (!buffer) {
79 printk(KERN_WARNING PREFIX "Invalid buffer argument\n");
80 return AE_BAD_PARAMETER;
81 }
82
83 format_count = (format->length / sizeof(char)) - 1;
84 if (format_count > package->package.count) {
85 printk(KERN_WARNING PREFIX "Format specifies more objects [%d]"
86 " than exist in package [%d].\n",
87 format_count, package->package.count);
88 return AE_BAD_DATA;
89 }
90
91 format_string = format->pointer;
92
93 /*
94 * Calculate size_required.
95 */
96 for (i = 0; i < format_count; i++) {
97
98 union acpi_object *element = &(package->package.elements[i]);
99
100 switch (element->type) {
101
102 case ACPI_TYPE_INTEGER:
103 switch (format_string[i]) {
104 case 'N':
105 size_required += sizeof(u64);
106 tail_offset += sizeof(u64);
107 break;
108 case 'S':
109 size_required +=
110 sizeof(char *) + sizeof(u64) +
111 sizeof(char);
112 tail_offset += sizeof(char *);
113 break;
114 default:
115 printk(KERN_WARNING PREFIX "Invalid package element"
116 " [%d]: got number, expecting"
117 " [%c]\n",
118 i, format_string[i]);
119 return AE_BAD_DATA;
120 break;
121 }
122 break;
123
124 case ACPI_TYPE_STRING:
125 case ACPI_TYPE_BUFFER:
126 switch (format_string[i]) {
127 case 'S':
128 size_required +=
129 sizeof(char *) +
130 (element->string.length * sizeof(char)) +
131 sizeof(char);
132 tail_offset += sizeof(char *);
133 break;
134 case 'B':
135 size_required +=
136 sizeof(u8 *) + element->buffer.length;
137 tail_offset += sizeof(u8 *);
138 break;
139 default:
140 printk(KERN_WARNING PREFIX "Invalid package element"
141 " [%d] got string/buffer,"
142 " expecting [%c]\n",
143 i, format_string[i]);
144 return AE_BAD_DATA;
145 break;
146 }
147 break;
148 case ACPI_TYPE_LOCAL_REFERENCE:
149 switch (format_string[i]) {
150 case 'R':
151 size_required += sizeof(void *);
152 tail_offset += sizeof(void *);
153 break;
154 default:
155 printk(KERN_WARNING PREFIX "Invalid package element"
156 " [%d] got reference,"
157 " expecting [%c]\n",
158 i, format_string[i]);
159 return AE_BAD_DATA;
160 break;
161 }
162 break;
163
164 case ACPI_TYPE_PACKAGE:
165 default:
166 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
167 "Found unsupported element at index=%d\n",
168 i));
169 /* TBD: handle nested packages... */
170 return AE_SUPPORT;
171 break;
172 }
173 }
174
175 /*
176 * Validate output buffer.
177 */
178 if (buffer->length == ACPI_ALLOCATE_BUFFER) {
179 buffer->pointer = ACPI_ALLOCATE_ZEROED(size_required);
180 if (!buffer->pointer)
181 return AE_NO_MEMORY;
182 buffer->length = size_required;
183 } else {
184 if (buffer->length < size_required) {
185 buffer->length = size_required;
186 return AE_BUFFER_OVERFLOW;
187 } else if (buffer->length != size_required ||
188 !buffer->pointer) {
189 return AE_BAD_PARAMETER;
190 }
191 }
192
193 head = buffer->pointer;
194 tail = buffer->pointer + tail_offset;
195
196 /*
197 * Extract package data.
198 */
199 for (i = 0; i < format_count; i++) {
200
201 u8 **pointer = NULL;
202 union acpi_object *element = &(package->package.elements[i]);
203
204 switch (element->type) {
205
206 case ACPI_TYPE_INTEGER:
207 switch (format_string[i]) {
208 case 'N':
209 *((u64 *) head) =
210 element->integer.value;
211 head += sizeof(u64);
212 break;
213 case 'S':
214 pointer = (u8 **) head;
215 *pointer = tail;
216 *((u64 *) tail) =
217 element->integer.value;
218 head += sizeof(u64 *);
219 tail += sizeof(u64);
220 /* NULL terminate string */
221 *tail = (char)0;
222 tail += sizeof(char);
223 break;
224 default:
225 /* Should never get here */
226 break;
227 }
228 break;
229
230 case ACPI_TYPE_STRING:
231 case ACPI_TYPE_BUFFER:
232 switch (format_string[i]) {
233 case 'S':
234 pointer = (u8 **) head;
235 *pointer = tail;
236 memcpy(tail, element->string.pointer,
237 element->string.length);
238 head += sizeof(char *);
239 tail += element->string.length * sizeof(char);
240 /* NULL terminate string */
241 *tail = (char)0;
242 tail += sizeof(char);
243 break;
244 case 'B':
245 pointer = (u8 **) head;
246 *pointer = tail;
247 memcpy(tail, element->buffer.pointer,
248 element->buffer.length);
249 head += sizeof(u8 *);
250 tail += element->buffer.length;
251 break;
252 default:
253 /* Should never get here */
254 break;
255 }
256 break;
257 case ACPI_TYPE_LOCAL_REFERENCE:
258 switch (format_string[i]) {
259 case 'R':
260 *(void **)head =
261 (void *)element->reference.handle;
262 head += sizeof(void *);
263 break;
264 default:
265 /* Should never get here */
266 break;
267 }
268 break;
269 case ACPI_TYPE_PACKAGE:
270 /* TBD: handle nested packages... */
271 default:
272 /* Should never get here */
273 break;
274 }
275 }
276
277 return AE_OK;
278}
279
280EXPORT_SYMBOL(acpi_extract_package);
281
282acpi_status
283acpi_evaluate_integer(acpi_handle handle,
284 acpi_string pathname,
285 struct acpi_object_list *arguments, unsigned long long *data)
286{
287 acpi_status status = AE_OK;
288 union acpi_object element;
289 struct acpi_buffer buffer = { 0, NULL };
290
291 if (!data)
292 return AE_BAD_PARAMETER;
293
294 buffer.length = sizeof(union acpi_object);
295 buffer.pointer = &element;
296 status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
297 if (ACPI_FAILURE(status)) {
298 acpi_util_eval_error(handle, pathname, status);
299 return status;
300 }
301
302 if (element.type != ACPI_TYPE_INTEGER) {
303 acpi_util_eval_error(handle, pathname, AE_BAD_DATA);
304 return AE_BAD_DATA;
305 }
306
307 *data = element.integer.value;
308
309 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Return value [%llu]\n", *data));
310
311 return AE_OK;
312}
313
314EXPORT_SYMBOL(acpi_evaluate_integer);
315
316acpi_status
317acpi_evaluate_reference(acpi_handle handle,
318 acpi_string pathname,
319 struct acpi_object_list *arguments,
320 struct acpi_handle_list *list)
321{
322 acpi_status status = AE_OK;
323 union acpi_object *package = NULL;
324 union acpi_object *element = NULL;
325 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
326 u32 i = 0;
327
328
329 if (!list) {
330 return AE_BAD_PARAMETER;
331 }
332
333 /* Evaluate object. */
334
335 status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
336 if (ACPI_FAILURE(status))
337 goto end;
338
339 package = buffer.pointer;
340
341 if ((buffer.length == 0) || !package) {
342 status = AE_BAD_DATA;
343 acpi_util_eval_error(handle, pathname, status);
344 goto end;
345 }
346 if (package->type != ACPI_TYPE_PACKAGE) {
347 status = AE_BAD_DATA;
348 acpi_util_eval_error(handle, pathname, status);
349 goto end;
350 }
351 if (!package->package.count) {
352 status = AE_BAD_DATA;
353 acpi_util_eval_error(handle, pathname, status);
354 goto end;
355 }
356
357 if (package->package.count > ACPI_MAX_HANDLES) {
358 kfree(package);
359 return AE_NO_MEMORY;
360 }
361 list->count = package->package.count;
362
363 /* Extract package data. */
364
365 for (i = 0; i < list->count; i++) {
366
367 element = &(package->package.elements[i]);
368
369 if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
370 status = AE_BAD_DATA;
371 acpi_util_eval_error(handle, pathname, status);
372 break;
373 }
374
375 if (!element->reference.handle) {
376 status = AE_NULL_ENTRY;
377 acpi_util_eval_error(handle, pathname, status);
378 break;
379 }
380 /* Get the acpi_handle. */
381
382 list->handles[i] = element->reference.handle;
383 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found reference [%p]\n",
384 list->handles[i]));
385 }
386
387 end:
388 if (ACPI_FAILURE(status)) {
389 list->count = 0;
390 //kfree(list->handles);
391 }
392
393 kfree(buffer.pointer);
394
395 return status;
396}
397
398EXPORT_SYMBOL(acpi_evaluate_reference);
399
400acpi_status
401acpi_get_physical_device_location(acpi_handle handle, struct acpi_pld_info **pld)
402{
403 acpi_status status;
404 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
405 union acpi_object *output;
406
407 status = acpi_evaluate_object(handle, "_PLD", NULL, &buffer);
408
409 if (ACPI_FAILURE(status))
410 return status;
411
412 output = buffer.pointer;
413
414 if (!output || output->type != ACPI_TYPE_PACKAGE
415 || !output->package.count
416 || output->package.elements[0].type != ACPI_TYPE_BUFFER
417 || output->package.elements[0].buffer.length < ACPI_PLD_REV1_BUFFER_SIZE) {
418 status = AE_TYPE;
419 goto out;
420 }
421
422 status = acpi_decode_pld_buffer(
423 output->package.elements[0].buffer.pointer,
424 output->package.elements[0].buffer.length,
425 pld);
426
427out:
428 kfree(buffer.pointer);
429 return status;
430}
431EXPORT_SYMBOL(acpi_get_physical_device_location);
432
433/**
434 * acpi_evaluate_ost: Evaluate _OST for hotplug operations
435 * @handle: ACPI device handle
436 * @source_event: source event code
437 * @status_code: status code
438 * @status_buf: optional detailed information (NULL if none)
439 *
440 * Evaluate _OST for hotplug operations. All ACPI hotplug handlers
441 * must call this function when evaluating _OST for hotplug operations.
442 * When the platform does not support _OST, this function has no effect.
443 */
444acpi_status
445acpi_evaluate_ost(acpi_handle handle, u32 source_event, u32 status_code,
446 struct acpi_buffer *status_buf)
447{
448 union acpi_object params[3] = {
449 {.type = ACPI_TYPE_INTEGER,},
450 {.type = ACPI_TYPE_INTEGER,},
451 {.type = ACPI_TYPE_BUFFER,}
452 };
453 struct acpi_object_list arg_list = {3, params};
454
455 params[0].integer.value = source_event;
456 params[1].integer.value = status_code;
457 if (status_buf != NULL) {
458 params[2].buffer.pointer = status_buf->pointer;
459 params[2].buffer.length = status_buf->length;
460 } else {
461 params[2].buffer.pointer = NULL;
462 params[2].buffer.length = 0;
463 }
464
465 return acpi_evaluate_object(handle, "_OST", &arg_list, NULL);
466}
467EXPORT_SYMBOL(acpi_evaluate_ost);
468
469/**
470 * acpi_handle_path: Return the object path of handle
471 *
472 * Caller must free the returned buffer
473 */
474static char *acpi_handle_path(acpi_handle handle)
475{
476 struct acpi_buffer buffer = {
477 .length = ACPI_ALLOCATE_BUFFER,
478 .pointer = NULL
479 };
480
481 if (in_interrupt() ||
482 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer) != AE_OK)
483 return NULL;
484 return buffer.pointer;
485}
486
487/**
488 * acpi_handle_printk: Print message with ACPI prefix and object path
489 *
490 * This function is called through acpi_handle_<level> macros and prints
491 * a message with ACPI prefix and object path. This function acquires
492 * the global namespace mutex to obtain an object path. In interrupt
493 * context, it shows the object path as <n/a>.
494 */
495void
496acpi_handle_printk(const char *level, acpi_handle handle, const char *fmt, ...)
497{
498 struct va_format vaf;
499 va_list args;
500 const char *path;
501
502 va_start(args, fmt);
503 vaf.fmt = fmt;
504 vaf.va = &args;
505
506 path = acpi_handle_path(handle);
507 printk("%sACPI: %s: %pV", level, path ? path : "<n/a>" , &vaf);
508
509 va_end(args);
510 kfree(path);
511}
512EXPORT_SYMBOL(acpi_handle_printk);
513
514#if defined(CONFIG_DYNAMIC_DEBUG)
515/**
516 * __acpi_handle_debug: pr_debug with ACPI prefix and object path
517 *
518 * This function is called through acpi_handle_debug macro and debug
519 * prints a message with ACPI prefix and object path. This function
520 * acquires the global namespace mutex to obtain an object path. In
521 * interrupt context, it shows the object path as <n/a>.
522 */
523void
524__acpi_handle_debug(struct _ddebug *descriptor, acpi_handle handle,
525 const char *fmt, ...)
526{
527 struct va_format vaf;
528 va_list args;
529 const char *path;
530
531 va_start(args, fmt);
532 vaf.fmt = fmt;
533 vaf.va = &args;
534
535 path = acpi_handle_path(handle);
536 __dynamic_pr_debug(descriptor, "ACPI: %s: %pV", path ? path : "<n/a>", &vaf);
537
538 va_end(args);
539 kfree(path);
540}
541EXPORT_SYMBOL(__acpi_handle_debug);
542#endif
543
544/**
545 * acpi_has_method: Check whether @handle has a method named @name
546 * @handle: ACPI device handle
547 * @name: name of object or method
548 *
549 * Check whether @handle has a method named @name.
550 */
551bool acpi_has_method(acpi_handle handle, char *name)
552{
553 acpi_handle tmp;
554
555 return ACPI_SUCCESS(acpi_get_handle(handle, name, &tmp));
556}
557EXPORT_SYMBOL(acpi_has_method);
558
559acpi_status acpi_execute_simple_method(acpi_handle handle, char *method,
560 u64 arg)
561{
562 union acpi_object obj = { .type = ACPI_TYPE_INTEGER };
563 struct acpi_object_list arg_list = { .count = 1, .pointer = &obj, };
564
565 obj.integer.value = arg;
566
567 return acpi_evaluate_object(handle, method, &arg_list, NULL);
568}
569EXPORT_SYMBOL(acpi_execute_simple_method);
570
571/**
572 * acpi_evaluate_ej0: Evaluate _EJ0 method for hotplug operations
573 * @handle: ACPI device handle
574 *
575 * Evaluate device's _EJ0 method for hotplug operations.
576 */
577acpi_status acpi_evaluate_ej0(acpi_handle handle)
578{
579 acpi_status status;
580
581 status = acpi_execute_simple_method(handle, "_EJ0", 1);
582 if (status == AE_NOT_FOUND)
583 acpi_handle_warn(handle, "No _EJ0 support for device\n");
584 else if (ACPI_FAILURE(status))
585 acpi_handle_warn(handle, "Eject failed (0x%x)\n", status);
586
587 return status;
588}
589
590/**
591 * acpi_evaluate_lck: Evaluate _LCK method to lock/unlock device
592 * @handle: ACPI device handle
593 * @lock: lock device if non-zero, otherwise unlock device
594 *
595 * Evaluate device's _LCK method if present to lock/unlock device
596 */
597acpi_status acpi_evaluate_lck(acpi_handle handle, int lock)
598{
599 acpi_status status;
600
601 status = acpi_execute_simple_method(handle, "_LCK", !!lock);
602 if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
603 if (lock)
604 acpi_handle_warn(handle,
605 "Locking device failed (0x%x)\n", status);
606 else
607 acpi_handle_warn(handle,
608 "Unlocking device failed (0x%x)\n", status);
609 }
610
611 return status;
612}
613
614/**
615 * acpi_evaluate_dsm - evaluate device's _DSM method
616 * @handle: ACPI device handle
617 * @guid: GUID of requested functions, should be 16 bytes
618 * @rev: revision number of requested function
619 * @func: requested function number
620 * @argv4: the function specific parameter
621 *
622 * Evaluate device's _DSM method with specified GUID, revision id and
623 * function number. Caller needs to free the returned object.
624 *
625 * Though ACPI defines the fourth parameter for _DSM should be a package,
626 * some old BIOSes do expect a buffer or an integer etc.
627 */
628union acpi_object *
629acpi_evaluate_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 func,
630 union acpi_object *argv4)
631{
632 acpi_status ret;
633 struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
634 union acpi_object params[4];
635 struct acpi_object_list input = {
636 .count = 4,
637 .pointer = params,
638 };
639
640 params[0].type = ACPI_TYPE_BUFFER;
641 params[0].buffer.length = 16;
642 params[0].buffer.pointer = (u8 *)guid;
643 params[1].type = ACPI_TYPE_INTEGER;
644 params[1].integer.value = rev;
645 params[2].type = ACPI_TYPE_INTEGER;
646 params[2].integer.value = func;
647 if (argv4) {
648 params[3] = *argv4;
649 } else {
650 params[3].type = ACPI_TYPE_PACKAGE;
651 params[3].package.count = 0;
652 params[3].package.elements = NULL;
653 }
654
655 ret = acpi_evaluate_object(handle, "_DSM", &input, &buf);
656 if (ACPI_SUCCESS(ret))
657 return (union acpi_object *)buf.pointer;
658
659 if (ret != AE_NOT_FOUND)
660 acpi_handle_warn(handle,
661 "failed to evaluate _DSM (0x%x)\n", ret);
662
663 return NULL;
664}
665EXPORT_SYMBOL(acpi_evaluate_dsm);
666
667/**
668 * acpi_check_dsm - check if _DSM method supports requested functions.
669 * @handle: ACPI device handle
670 * @guid: GUID of requested functions, should be 16 bytes at least
671 * @rev: revision number of requested functions
672 * @funcs: bitmap of requested functions
673 *
674 * Evaluate device's _DSM method to check whether it supports requested
675 * functions. Currently only support 64 functions at maximum, should be
676 * enough for now.
677 */
678bool acpi_check_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 funcs)
679{
680 int i;
681 u64 mask = 0;
682 union acpi_object *obj;
683
684 if (funcs == 0)
685 return false;
686
687 obj = acpi_evaluate_dsm(handle, guid, rev, 0, NULL);
688 if (!obj)
689 return false;
690
691 /* For compatibility, old BIOSes may return an integer */
692 if (obj->type == ACPI_TYPE_INTEGER)
693 mask = obj->integer.value;
694 else if (obj->type == ACPI_TYPE_BUFFER)
695 for (i = 0; i < obj->buffer.length && i < 8; i++)
696 mask |= (((u64)obj->buffer.pointer[i]) << (i * 8));
697 ACPI_FREE(obj);
698
699 /*
700 * Bit 0 indicates whether there's support for any functions other than
701 * function 0 for the specified GUID and revision.
702 */
703 if ((mask & 0x1) && (mask & funcs) == funcs)
704 return true;
705
706 return false;
707}
708EXPORT_SYMBOL(acpi_check_dsm);
709
710/**
711 * acpi_dev_found - Detect presence of a given ACPI device in the namespace.
712 * @hid: Hardware ID of the device.
713 *
714 * Return %true if the device was present at the moment of invocation.
715 * Note that if the device is pluggable, it may since have disappeared.
716 *
717 * For this function to work, acpi_bus_scan() must have been executed
718 * which happens in the subsys_initcall() subsection. Hence, do not
719 * call from a subsys_initcall() or earlier (use acpi_get_devices()
720 * instead). Calling from module_init() is fine (which is synonymous
721 * with device_initcall()).
722 */
723bool acpi_dev_found(const char *hid)
724{
725 struct acpi_device_bus_id *acpi_device_bus_id;
726 bool found = false;
727
728 mutex_lock(&acpi_device_lock);
729 list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
730 if (!strcmp(acpi_device_bus_id->bus_id, hid)) {
731 found = true;
732 break;
733 }
734 mutex_unlock(&acpi_device_lock);
735
736 return found;
737}
738EXPORT_SYMBOL(acpi_dev_found);
739
740struct acpi_dev_match_info {
741 const char *dev_name;
742 struct acpi_device_id hid[2];
743 const char *uid;
744 s64 hrv;
745};
746
747static int acpi_dev_match_cb(struct device *dev, void *data)
748{
749 struct acpi_device *adev = to_acpi_device(dev);
750 struct acpi_dev_match_info *match = data;
751 unsigned long long hrv;
752 acpi_status status;
753
754 if (acpi_match_device_ids(adev, match->hid))
755 return 0;
756
757 if (match->uid && (!adev->pnp.unique_id ||
758 strcmp(adev->pnp.unique_id, match->uid)))
759 return 0;
760
761 match->dev_name = acpi_dev_name(adev);
762
763 if (match->hrv == -1)
764 return 1;
765
766 status = acpi_evaluate_integer(adev->handle, "_HRV", NULL, &hrv);
767 if (ACPI_FAILURE(status))
768 return 0;
769
770 return hrv == match->hrv;
771}
772
773/**
774 * acpi_dev_present - Detect that a given ACPI device is present
775 * @hid: Hardware ID of the device.
776 * @uid: Unique ID of the device, pass NULL to not check _UID
777 * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
778 *
779 * Return %true if a matching device was present at the moment of invocation.
780 * Note that if the device is pluggable, it may since have disappeared.
781 *
782 * Note that unlike acpi_dev_found() this function checks the status
783 * of the device. So for devices which are present in the dsdt, but
784 * which are disabled (their _STA callback returns 0) this function
785 * will return false.
786 *
787 * For this function to work, acpi_bus_scan() must have been executed
788 * which happens in the subsys_initcall() subsection. Hence, do not
789 * call from a subsys_initcall() or earlier (use acpi_get_devices()
790 * instead). Calling from module_init() is fine (which is synonymous
791 * with device_initcall()).
792 */
793bool acpi_dev_present(const char *hid, const char *uid, s64 hrv)
794{
795 struct acpi_dev_match_info match = {};
796 struct device *dev;
797
798 strlcpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
799 match.uid = uid;
800 match.hrv = hrv;
801
802 dev = bus_find_device(&acpi_bus_type, NULL, &match, acpi_dev_match_cb);
803 put_device(dev);
804 return !!dev;
805}
806EXPORT_SYMBOL(acpi_dev_present);
807
808/**
809 * acpi_dev_get_first_match_name - Return name of first match of ACPI device
810 * @hid: Hardware ID of the device.
811 * @uid: Unique ID of the device, pass NULL to not check _UID
812 * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
813 *
814 * Return device name if a matching device was present
815 * at the moment of invocation, or NULL otherwise.
816 *
817 * See additional information in acpi_dev_present() as well.
818 */
819const char *
820acpi_dev_get_first_match_name(const char *hid, const char *uid, s64 hrv)
821{
822 struct acpi_dev_match_info match = {};
823 struct device *dev;
824
825 strlcpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
826 match.uid = uid;
827 match.hrv = hrv;
828
829 dev = bus_find_device(&acpi_bus_type, NULL, &match, acpi_dev_match_cb);
830 return dev ? match.dev_name : NULL;
831}
832EXPORT_SYMBOL(acpi_dev_get_first_match_name);
833
834/*
835 * acpi_backlight= handling, this is done here rather then in video_detect.c
836 * because __setup cannot be used in modules.
837 */
838char acpi_video_backlight_string[16];
839EXPORT_SYMBOL(acpi_video_backlight_string);
840
841static int __init acpi_backlight(char *str)
842{
843 strlcpy(acpi_video_backlight_string, str,
844 sizeof(acpi_video_backlight_string));
845 return 1;
846}
847__setup("acpi_backlight=", acpi_backlight);
848
849/**
850 * acpi_match_platform_list - Check if the system matches with a given list
851 * @plat: pointer to acpi_platform_list table terminated by a NULL entry
852 *
853 * Return the matched index if the system is found in the platform list.
854 * Otherwise, return a negative error code.
855 */
856int acpi_match_platform_list(const struct acpi_platform_list *plat)
857{
858 struct acpi_table_header hdr;
859 int idx = 0;
860
861 if (acpi_disabled)
862 return -ENODEV;
863
864 for (; plat->oem_id[0]; plat++, idx++) {
865 if (ACPI_FAILURE(acpi_get_table_header(plat->table, 0, &hdr)))
866 continue;
867
868 if (strncmp(plat->oem_id, hdr.oem_id, ACPI_OEM_ID_SIZE))
869 continue;
870
871 if (strncmp(plat->oem_table_id, hdr.oem_table_id, ACPI_OEM_TABLE_ID_SIZE))
872 continue;
873
874 if ((plat->pred == all_versions) ||
875 (plat->pred == less_than_or_equal && hdr.oem_revision <= plat->oem_revision) ||
876 (plat->pred == greater_than_or_equal && hdr.oem_revision >= plat->oem_revision) ||
877 (plat->pred == equal && hdr.oem_revision == plat->oem_revision))
878 return idx;
879 }
880
881 return -ENODEV;
882}
883EXPORT_SYMBOL(acpi_match_platform_list);
884