Input: i8042 - add Acer Aspire 5738z to nomux list
[linux-2.6-microblaze.git] / drivers / acpi / utils.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  acpi_utils.c - ACPI Utility Functions ($Revision: 10 $)
4  *
5  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
6  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
7  */
8
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/slab.h>
12 #include <linux/init.h>
13 #include <linux/types.h>
14 #include <linux/hardirq.h>
15 #include <linux/acpi.h>
16 #include <linux/dynamic_debug.h>
17
18 #include "internal.h"
19 #include "sleep.h"
20
21 #define _COMPONENT              ACPI_BUS_COMPONENT
22 ACPI_MODULE_NAME("utils");
23
24 /* --------------------------------------------------------------------------
25                             Object Evaluation Helpers
26    -------------------------------------------------------------------------- */
27 static void
28 acpi_util_eval_error(acpi_handle h, acpi_string p, acpi_status s)
29 {
30 #ifdef ACPI_DEBUG_OUTPUT
31         char prefix[80] = {'\0'};
32         struct acpi_buffer buffer = {sizeof(prefix), prefix};
33         acpi_get_name(h, ACPI_FULL_PATHNAME, &buffer);
34         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Evaluate [%s.%s]: %s\n",
35                 (char *) prefix, p, acpi_format_exception(s)));
36 #else
37         return;
38 #endif
39 }
40
41 acpi_status
42 acpi_extract_package(union acpi_object *package,
43                      struct acpi_buffer *format, struct acpi_buffer *buffer)
44 {
45         u32 size_required = 0;
46         u32 tail_offset = 0;
47         char *format_string = NULL;
48         u32 format_count = 0;
49         u32 i = 0;
50         u8 *head = NULL;
51         u8 *tail = NULL;
52
53
54         if (!package || (package->type != ACPI_TYPE_PACKAGE)
55             || (package->package.count < 1)) {
56                 printk(KERN_WARNING PREFIX "Invalid package argument\n");
57                 return AE_BAD_PARAMETER;
58         }
59
60         if (!format || !format->pointer || (format->length < 1)) {
61                 printk(KERN_WARNING PREFIX "Invalid format argument\n");
62                 return AE_BAD_PARAMETER;
63         }
64
65         if (!buffer) {
66                 printk(KERN_WARNING PREFIX "Invalid buffer argument\n");
67                 return AE_BAD_PARAMETER;
68         }
69
70         format_count = (format->length / sizeof(char)) - 1;
71         if (format_count > package->package.count) {
72                 printk(KERN_WARNING PREFIX "Format specifies more objects [%d]"
73                               " than exist in package [%d].\n",
74                               format_count, package->package.count);
75                 return AE_BAD_DATA;
76         }
77
78         format_string = format->pointer;
79
80         /*
81          * Calculate size_required.
82          */
83         for (i = 0; i < format_count; i++) {
84
85                 union acpi_object *element = &(package->package.elements[i]);
86
87                 switch (element->type) {
88
89                 case ACPI_TYPE_INTEGER:
90                         switch (format_string[i]) {
91                         case 'N':
92                                 size_required += sizeof(u64);
93                                 tail_offset += sizeof(u64);
94                                 break;
95                         case 'S':
96                                 size_required +=
97                                     sizeof(char *) + sizeof(u64) +
98                                     sizeof(char);
99                                 tail_offset += sizeof(char *);
100                                 break;
101                         default:
102                                 printk(KERN_WARNING PREFIX "Invalid package element"
103                                               " [%d]: got number, expecting"
104                                               " [%c]\n",
105                                               i, format_string[i]);
106                                 return AE_BAD_DATA;
107                                 break;
108                         }
109                         break;
110
111                 case ACPI_TYPE_STRING:
112                 case ACPI_TYPE_BUFFER:
113                         switch (format_string[i]) {
114                         case 'S':
115                                 size_required +=
116                                     sizeof(char *) +
117                                     (element->string.length * sizeof(char)) +
118                                     sizeof(char);
119                                 tail_offset += sizeof(char *);
120                                 break;
121                         case 'B':
122                                 size_required +=
123                                     sizeof(u8 *) + element->buffer.length;
124                                 tail_offset += sizeof(u8 *);
125                                 break;
126                         default:
127                                 printk(KERN_WARNING PREFIX "Invalid package element"
128                                               " [%d] got string/buffer,"
129                                               " expecting [%c]\n",
130                                               i, format_string[i]);
131                                 return AE_BAD_DATA;
132                                 break;
133                         }
134                         break;
135                 case ACPI_TYPE_LOCAL_REFERENCE:
136                         switch (format_string[i]) {
137                         case 'R':
138                                 size_required += sizeof(void *);
139                                 tail_offset += sizeof(void *);
140                                 break;
141                         default:
142                                 printk(KERN_WARNING PREFIX "Invalid package element"
143                                               " [%d] got reference,"
144                                               " expecting [%c]\n",
145                                               i, format_string[i]);
146                                 return AE_BAD_DATA;
147                                 break;
148                         }
149                         break;
150
151                 case ACPI_TYPE_PACKAGE:
152                 default:
153                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
154                                           "Found unsupported element at index=%d\n",
155                                           i));
156                         /* TBD: handle nested packages... */
157                         return AE_SUPPORT;
158                         break;
159                 }
160         }
161
162         /*
163          * Validate output buffer.
164          */
165         if (buffer->length == ACPI_ALLOCATE_BUFFER) {
166                 buffer->pointer = ACPI_ALLOCATE_ZEROED(size_required);
167                 if (!buffer->pointer)
168                         return AE_NO_MEMORY;
169                 buffer->length = size_required;
170         } else {
171                 if (buffer->length < size_required) {
172                         buffer->length = size_required;
173                         return AE_BUFFER_OVERFLOW;
174                 } else if (buffer->length != size_required ||
175                            !buffer->pointer) {
176                         return AE_BAD_PARAMETER;
177                 }
178         }
179
180         head = buffer->pointer;
181         tail = buffer->pointer + tail_offset;
182
183         /*
184          * Extract package data.
185          */
186         for (i = 0; i < format_count; i++) {
187
188                 u8 **pointer = NULL;
189                 union acpi_object *element = &(package->package.elements[i]);
190
191                 switch (element->type) {
192
193                 case ACPI_TYPE_INTEGER:
194                         switch (format_string[i]) {
195                         case 'N':
196                                 *((u64 *) head) =
197                                     element->integer.value;
198                                 head += sizeof(u64);
199                                 break;
200                         case 'S':
201                                 pointer = (u8 **) head;
202                                 *pointer = tail;
203                                 *((u64 *) tail) =
204                                     element->integer.value;
205                                 head += sizeof(u64 *);
206                                 tail += sizeof(u64);
207                                 /* NULL terminate string */
208                                 *tail = (char)0;
209                                 tail += sizeof(char);
210                                 break;
211                         default:
212                                 /* Should never get here */
213                                 break;
214                         }
215                         break;
216
217                 case ACPI_TYPE_STRING:
218                 case ACPI_TYPE_BUFFER:
219                         switch (format_string[i]) {
220                         case 'S':
221                                 pointer = (u8 **) head;
222                                 *pointer = tail;
223                                 memcpy(tail, element->string.pointer,
224                                        element->string.length);
225                                 head += sizeof(char *);
226                                 tail += element->string.length * sizeof(char);
227                                 /* NULL terminate string */
228                                 *tail = (char)0;
229                                 tail += sizeof(char);
230                                 break;
231                         case 'B':
232                                 pointer = (u8 **) head;
233                                 *pointer = tail;
234                                 memcpy(tail, element->buffer.pointer,
235                                        element->buffer.length);
236                                 head += sizeof(u8 *);
237                                 tail += element->buffer.length;
238                                 break;
239                         default:
240                                 /* Should never get here */
241                                 break;
242                         }
243                         break;
244                 case ACPI_TYPE_LOCAL_REFERENCE:
245                         switch (format_string[i]) {
246                         case 'R':
247                                 *(void **)head =
248                                     (void *)element->reference.handle;
249                                 head += sizeof(void *);
250                                 break;
251                         default:
252                                 /* Should never get here */
253                                 break;
254                         }
255                         break;
256                 case ACPI_TYPE_PACKAGE:
257                         /* TBD: handle nested packages... */
258                 default:
259                         /* Should never get here */
260                         break;
261                 }
262         }
263
264         return AE_OK;
265 }
266
267 EXPORT_SYMBOL(acpi_extract_package);
268
269 acpi_status
270 acpi_evaluate_integer(acpi_handle handle,
271                       acpi_string pathname,
272                       struct acpi_object_list *arguments, unsigned long long *data)
273 {
274         acpi_status status = AE_OK;
275         union acpi_object element;
276         struct acpi_buffer buffer = { 0, NULL };
277
278         if (!data)
279                 return AE_BAD_PARAMETER;
280
281         buffer.length = sizeof(union acpi_object);
282         buffer.pointer = &element;
283         status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
284         if (ACPI_FAILURE(status)) {
285                 acpi_util_eval_error(handle, pathname, status);
286                 return status;
287         }
288
289         if (element.type != ACPI_TYPE_INTEGER) {
290                 acpi_util_eval_error(handle, pathname, AE_BAD_DATA);
291                 return AE_BAD_DATA;
292         }
293
294         *data = element.integer.value;
295
296         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Return value [%llu]\n", *data));
297
298         return AE_OK;
299 }
300
301 EXPORT_SYMBOL(acpi_evaluate_integer);
302
303 acpi_status
304 acpi_evaluate_reference(acpi_handle handle,
305                         acpi_string pathname,
306                         struct acpi_object_list *arguments,
307                         struct acpi_handle_list *list)
308 {
309         acpi_status status = AE_OK;
310         union acpi_object *package = NULL;
311         union acpi_object *element = NULL;
312         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
313         u32 i = 0;
314
315
316         if (!list) {
317                 return AE_BAD_PARAMETER;
318         }
319
320         /* Evaluate object. */
321
322         status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
323         if (ACPI_FAILURE(status))
324                 goto end;
325
326         package = buffer.pointer;
327
328         if ((buffer.length == 0) || !package) {
329                 status = AE_BAD_DATA;
330                 acpi_util_eval_error(handle, pathname, status);
331                 goto end;
332         }
333         if (package->type != ACPI_TYPE_PACKAGE) {
334                 status = AE_BAD_DATA;
335                 acpi_util_eval_error(handle, pathname, status);
336                 goto end;
337         }
338         if (!package->package.count) {
339                 status = AE_BAD_DATA;
340                 acpi_util_eval_error(handle, pathname, status);
341                 goto end;
342         }
343
344         if (package->package.count > ACPI_MAX_HANDLES) {
345                 kfree(package);
346                 return AE_NO_MEMORY;
347         }
348         list->count = package->package.count;
349
350         /* Extract package data. */
351
352         for (i = 0; i < list->count; i++) {
353
354                 element = &(package->package.elements[i]);
355
356                 if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
357                         status = AE_BAD_DATA;
358                         acpi_util_eval_error(handle, pathname, status);
359                         break;
360                 }
361
362                 if (!element->reference.handle) {
363                         status = AE_NULL_ENTRY;
364                         acpi_util_eval_error(handle, pathname, status);
365                         break;
366                 }
367                 /* Get the  acpi_handle. */
368
369                 list->handles[i] = element->reference.handle;
370                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found reference [%p]\n",
371                                   list->handles[i]));
372         }
373
374       end:
375         if (ACPI_FAILURE(status)) {
376                 list->count = 0;
377                 //kfree(list->handles);
378         }
379
380         kfree(buffer.pointer);
381
382         return status;
383 }
384
385 EXPORT_SYMBOL(acpi_evaluate_reference);
386
387 acpi_status
388 acpi_get_physical_device_location(acpi_handle handle, struct acpi_pld_info **pld)
389 {
390         acpi_status status;
391         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
392         union acpi_object *output;
393
394         status = acpi_evaluate_object(handle, "_PLD", NULL, &buffer);
395
396         if (ACPI_FAILURE(status))
397                 return status;
398
399         output = buffer.pointer;
400
401         if (!output || output->type != ACPI_TYPE_PACKAGE
402             || !output->package.count
403             || output->package.elements[0].type != ACPI_TYPE_BUFFER
404             || output->package.elements[0].buffer.length < ACPI_PLD_REV1_BUFFER_SIZE) {
405                 status = AE_TYPE;
406                 goto out;
407         }
408
409         status = acpi_decode_pld_buffer(
410                         output->package.elements[0].buffer.pointer,
411                         output->package.elements[0].buffer.length,
412                         pld);
413
414 out:
415         kfree(buffer.pointer);
416         return status;
417 }
418 EXPORT_SYMBOL(acpi_get_physical_device_location);
419
420 /**
421  * acpi_evaluate_ost: Evaluate _OST for hotplug operations
422  * @handle: ACPI device handle
423  * @source_event: source event code
424  * @status_code: status code
425  * @status_buf: optional detailed information (NULL if none)
426  *
427  * Evaluate _OST for hotplug operations. All ACPI hotplug handlers
428  * must call this function when evaluating _OST for hotplug operations.
429  * When the platform does not support _OST, this function has no effect.
430  */
431 acpi_status
432 acpi_evaluate_ost(acpi_handle handle, u32 source_event, u32 status_code,
433                   struct acpi_buffer *status_buf)
434 {
435         union acpi_object params[3] = {
436                 {.type = ACPI_TYPE_INTEGER,},
437                 {.type = ACPI_TYPE_INTEGER,},
438                 {.type = ACPI_TYPE_BUFFER,}
439         };
440         struct acpi_object_list arg_list = {3, params};
441
442         params[0].integer.value = source_event;
443         params[1].integer.value = status_code;
444         if (status_buf != NULL) {
445                 params[2].buffer.pointer = status_buf->pointer;
446                 params[2].buffer.length = status_buf->length;
447         } else {
448                 params[2].buffer.pointer = NULL;
449                 params[2].buffer.length = 0;
450         }
451
452         return acpi_evaluate_object(handle, "_OST", &arg_list, NULL);
453 }
454 EXPORT_SYMBOL(acpi_evaluate_ost);
455
456 /**
457  * acpi_handle_path: Return the object path of handle
458  * @handle: ACPI device handle
459  *
460  * Caller must free the returned buffer
461  */
462 static char *acpi_handle_path(acpi_handle handle)
463 {
464         struct acpi_buffer buffer = {
465                 .length = ACPI_ALLOCATE_BUFFER,
466                 .pointer = NULL
467         };
468
469         if (in_interrupt() ||
470             acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer) != AE_OK)
471                 return NULL;
472         return buffer.pointer;
473 }
474
475 /**
476  * acpi_handle_printk: Print message with ACPI prefix and object path
477  * @level: log level
478  * @handle: ACPI device handle
479  * @fmt: format string
480  *
481  * This function is called through acpi_handle_<level> macros and prints
482  * a message with ACPI prefix and object path.  This function acquires
483  * the global namespace mutex to obtain an object path.  In interrupt
484  * context, it shows the object path as <n/a>.
485  */
486 void
487 acpi_handle_printk(const char *level, acpi_handle handle, const char *fmt, ...)
488 {
489         struct va_format vaf;
490         va_list args;
491         const char *path;
492
493         va_start(args, fmt);
494         vaf.fmt = fmt;
495         vaf.va = &args;
496
497         path = acpi_handle_path(handle);
498         printk("%sACPI: %s: %pV", level, path ? path : "<n/a>" , &vaf);
499
500         va_end(args);
501         kfree(path);
502 }
503 EXPORT_SYMBOL(acpi_handle_printk);
504
505 #if defined(CONFIG_DYNAMIC_DEBUG)
506 /**
507  * __acpi_handle_debug: pr_debug with ACPI prefix and object path
508  * @descriptor: Dynamic Debug descriptor
509  * @handle: ACPI device handle
510  * @fmt: format string
511  *
512  * This function is called through acpi_handle_debug macro and debug
513  * prints a message with ACPI prefix and object path. This function
514  * acquires the global namespace mutex to obtain an object path.  In
515  * interrupt context, it shows the object path as <n/a>.
516  */
517 void
518 __acpi_handle_debug(struct _ddebug *descriptor, acpi_handle handle,
519                     const char *fmt, ...)
520 {
521         struct va_format vaf;
522         va_list args;
523         const char *path;
524
525         va_start(args, fmt);
526         vaf.fmt = fmt;
527         vaf.va = &args;
528
529         path = acpi_handle_path(handle);
530         __dynamic_pr_debug(descriptor, "ACPI: %s: %pV", path ? path : "<n/a>", &vaf);
531
532         va_end(args);
533         kfree(path);
534 }
535 EXPORT_SYMBOL(__acpi_handle_debug);
536 #endif
537
538 /**
539  * acpi_has_method: Check whether @handle has a method named @name
540  * @handle: ACPI device handle
541  * @name: name of object or method
542  *
543  * Check whether @handle has a method named @name.
544  */
545 bool acpi_has_method(acpi_handle handle, char *name)
546 {
547         acpi_handle tmp;
548
549         return ACPI_SUCCESS(acpi_get_handle(handle, name, &tmp));
550 }
551 EXPORT_SYMBOL(acpi_has_method);
552
553 acpi_status acpi_execute_simple_method(acpi_handle handle, char *method,
554                                        u64 arg)
555 {
556         union acpi_object obj = { .type = ACPI_TYPE_INTEGER };
557         struct acpi_object_list arg_list = { .count = 1, .pointer = &obj, };
558
559         obj.integer.value = arg;
560
561         return acpi_evaluate_object(handle, method, &arg_list, NULL);
562 }
563 EXPORT_SYMBOL(acpi_execute_simple_method);
564
565 /**
566  * acpi_evaluate_ej0: Evaluate _EJ0 method for hotplug operations
567  * @handle: ACPI device handle
568  *
569  * Evaluate device's _EJ0 method for hotplug operations.
570  */
571 acpi_status acpi_evaluate_ej0(acpi_handle handle)
572 {
573         acpi_status status;
574
575         status = acpi_execute_simple_method(handle, "_EJ0", 1);
576         if (status == AE_NOT_FOUND)
577                 acpi_handle_warn(handle, "No _EJ0 support for device\n");
578         else if (ACPI_FAILURE(status))
579                 acpi_handle_warn(handle, "Eject failed (0x%x)\n", status);
580
581         return status;
582 }
583
584 /**
585  * acpi_evaluate_lck: Evaluate _LCK method to lock/unlock device
586  * @handle: ACPI device handle
587  * @lock: lock device if non-zero, otherwise unlock device
588  *
589  * Evaluate device's _LCK method if present to lock/unlock device
590  */
591 acpi_status acpi_evaluate_lck(acpi_handle handle, int lock)
592 {
593         acpi_status status;
594
595         status = acpi_execute_simple_method(handle, "_LCK", !!lock);
596         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
597                 if (lock)
598                         acpi_handle_warn(handle,
599                                 "Locking device failed (0x%x)\n", status);
600                 else
601                         acpi_handle_warn(handle,
602                                 "Unlocking device failed (0x%x)\n", status);
603         }
604
605         return status;
606 }
607
608 /**
609  * acpi_evaluate_dsm - evaluate device's _DSM method
610  * @handle: ACPI device handle
611  * @guid: GUID of requested functions, should be 16 bytes
612  * @rev: revision number of requested function
613  * @func: requested function number
614  * @argv4: the function specific parameter
615  *
616  * Evaluate device's _DSM method with specified GUID, revision id and
617  * function number. Caller needs to free the returned object.
618  *
619  * Though ACPI defines the fourth parameter for _DSM should be a package,
620  * some old BIOSes do expect a buffer or an integer etc.
621  */
622 union acpi_object *
623 acpi_evaluate_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 func,
624                   union acpi_object *argv4)
625 {
626         acpi_status ret;
627         struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
628         union acpi_object params[4];
629         struct acpi_object_list input = {
630                 .count = 4,
631                 .pointer = params,
632         };
633
634         params[0].type = ACPI_TYPE_BUFFER;
635         params[0].buffer.length = 16;
636         params[0].buffer.pointer = (u8 *)guid;
637         params[1].type = ACPI_TYPE_INTEGER;
638         params[1].integer.value = rev;
639         params[2].type = ACPI_TYPE_INTEGER;
640         params[2].integer.value = func;
641         if (argv4) {
642                 params[3] = *argv4;
643         } else {
644                 params[3].type = ACPI_TYPE_PACKAGE;
645                 params[3].package.count = 0;
646                 params[3].package.elements = NULL;
647         }
648
649         ret = acpi_evaluate_object(handle, "_DSM", &input, &buf);
650         if (ACPI_SUCCESS(ret))
651                 return (union acpi_object *)buf.pointer;
652
653         if (ret != AE_NOT_FOUND)
654                 acpi_handle_warn(handle,
655                                 "failed to evaluate _DSM (0x%x)\n", ret);
656
657         return NULL;
658 }
659 EXPORT_SYMBOL(acpi_evaluate_dsm);
660
661 /**
662  * acpi_check_dsm - check if _DSM method supports requested functions.
663  * @handle: ACPI device handle
664  * @guid: GUID of requested functions, should be 16 bytes at least
665  * @rev: revision number of requested functions
666  * @funcs: bitmap of requested functions
667  *
668  * Evaluate device's _DSM method to check whether it supports requested
669  * functions. Currently only support 64 functions at maximum, should be
670  * enough for now.
671  */
672 bool acpi_check_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 funcs)
673 {
674         int i;
675         u64 mask = 0;
676         union acpi_object *obj;
677
678         if (funcs == 0)
679                 return false;
680
681         obj = acpi_evaluate_dsm(handle, guid, rev, 0, NULL);
682         if (!obj)
683                 return false;
684
685         /* For compatibility, old BIOSes may return an integer */
686         if (obj->type == ACPI_TYPE_INTEGER)
687                 mask = obj->integer.value;
688         else if (obj->type == ACPI_TYPE_BUFFER)
689                 for (i = 0; i < obj->buffer.length && i < 8; i++)
690                         mask |= (((u64)obj->buffer.pointer[i]) << (i * 8));
691         ACPI_FREE(obj);
692
693         /*
694          * Bit 0 indicates whether there's support for any functions other than
695          * function 0 for the specified GUID and revision.
696          */
697         if ((mask & 0x1) && (mask & funcs) == funcs)
698                 return true;
699
700         return false;
701 }
702 EXPORT_SYMBOL(acpi_check_dsm);
703
704 /**
705  * acpi_dev_hid_uid_match - Match device by supplied HID and UID
706  * @adev: ACPI device to match.
707  * @hid2: Hardware ID of the device.
708  * @uid2: Unique ID of the device, pass NULL to not check _UID.
709  *
710  * Matches HID and UID in @adev with given @hid2 and @uid2.
711  * Returns true if matches.
712  */
713 bool acpi_dev_hid_uid_match(struct acpi_device *adev,
714                             const char *hid2, const char *uid2)
715 {
716         const char *hid1 = acpi_device_hid(adev);
717         const char *uid1 = acpi_device_uid(adev);
718
719         if (strcmp(hid1, hid2))
720                 return false;
721
722         if (!uid2)
723                 return true;
724
725         return uid1 && !strcmp(uid1, uid2);
726 }
727 EXPORT_SYMBOL(acpi_dev_hid_uid_match);
728
729 /**
730  * acpi_dev_found - Detect presence of a given ACPI device in the namespace.
731  * @hid: Hardware ID of the device.
732  *
733  * Return %true if the device was present at the moment of invocation.
734  * Note that if the device is pluggable, it may since have disappeared.
735  *
736  * For this function to work, acpi_bus_scan() must have been executed
737  * which happens in the subsys_initcall() subsection. Hence, do not
738  * call from a subsys_initcall() or earlier (use acpi_get_devices()
739  * instead). Calling from module_init() is fine (which is synonymous
740  * with device_initcall()).
741  */
742 bool acpi_dev_found(const char *hid)
743 {
744         struct acpi_device_bus_id *acpi_device_bus_id;
745         bool found = false;
746
747         mutex_lock(&acpi_device_lock);
748         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
749                 if (!strcmp(acpi_device_bus_id->bus_id, hid)) {
750                         found = true;
751                         break;
752                 }
753         mutex_unlock(&acpi_device_lock);
754
755         return found;
756 }
757 EXPORT_SYMBOL(acpi_dev_found);
758
759 struct acpi_dev_match_info {
760         struct acpi_device_id hid[2];
761         const char *uid;
762         s64 hrv;
763 };
764
765 static int acpi_dev_match_cb(struct device *dev, const void *data)
766 {
767         struct acpi_device *adev = to_acpi_device(dev);
768         const struct acpi_dev_match_info *match = data;
769         unsigned long long hrv;
770         acpi_status status;
771
772         if (acpi_match_device_ids(adev, match->hid))
773                 return 0;
774
775         if (match->uid && (!adev->pnp.unique_id ||
776             strcmp(adev->pnp.unique_id, match->uid)))
777                 return 0;
778
779         if (match->hrv == -1)
780                 return 1;
781
782         status = acpi_evaluate_integer(adev->handle, "_HRV", NULL, &hrv);
783         if (ACPI_FAILURE(status))
784                 return 0;
785
786         return hrv == match->hrv;
787 }
788
789 /**
790  * acpi_dev_present - Detect that a given ACPI device is present
791  * @hid: Hardware ID of the device.
792  * @uid: Unique ID of the device, pass NULL to not check _UID
793  * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
794  *
795  * Return %true if a matching device was present at the moment of invocation.
796  * Note that if the device is pluggable, it may since have disappeared.
797  *
798  * Note that unlike acpi_dev_found() this function checks the status
799  * of the device. So for devices which are present in the dsdt, but
800  * which are disabled (their _STA callback returns 0) this function
801  * will return false.
802  *
803  * For this function to work, acpi_bus_scan() must have been executed
804  * which happens in the subsys_initcall() subsection. Hence, do not
805  * call from a subsys_initcall() or earlier (use acpi_get_devices()
806  * instead). Calling from module_init() is fine (which is synonymous
807  * with device_initcall()).
808  */
809 bool acpi_dev_present(const char *hid, const char *uid, s64 hrv)
810 {
811         struct acpi_dev_match_info match = {};
812         struct device *dev;
813
814         strlcpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
815         match.uid = uid;
816         match.hrv = hrv;
817
818         dev = bus_find_device(&acpi_bus_type, NULL, &match, acpi_dev_match_cb);
819         put_device(dev);
820         return !!dev;
821 }
822 EXPORT_SYMBOL(acpi_dev_present);
823
824 /**
825  * acpi_dev_get_first_match_dev - Return the first match of ACPI device
826  * @hid: Hardware ID of the device.
827  * @uid: Unique ID of the device, pass NULL to not check _UID
828  * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
829  *
830  * Return the first match of ACPI device if a matching device was present
831  * at the moment of invocation, or NULL otherwise.
832  *
833  * The caller is responsible to call put_device() on the returned device.
834  *
835  * See additional information in acpi_dev_present() as well.
836  */
837 struct acpi_device *
838 acpi_dev_get_first_match_dev(const char *hid, const char *uid, s64 hrv)
839 {
840         struct acpi_dev_match_info match = {};
841         struct device *dev;
842
843         strlcpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
844         match.uid = uid;
845         match.hrv = hrv;
846
847         dev = bus_find_device(&acpi_bus_type, NULL, &match, acpi_dev_match_cb);
848         return dev ? to_acpi_device(dev) : NULL;
849 }
850 EXPORT_SYMBOL(acpi_dev_get_first_match_dev);
851
852 /*
853  * acpi_backlight= handling, this is done here rather then in video_detect.c
854  * because __setup cannot be used in modules.
855  */
856 char acpi_video_backlight_string[16];
857 EXPORT_SYMBOL(acpi_video_backlight_string);
858
859 static int __init acpi_backlight(char *str)
860 {
861         strlcpy(acpi_video_backlight_string, str,
862                 sizeof(acpi_video_backlight_string));
863         return 1;
864 }
865 __setup("acpi_backlight=", acpi_backlight);
866
867 /**
868  * acpi_match_platform_list - Check if the system matches with a given list
869  * @plat: pointer to acpi_platform_list table terminated by a NULL entry
870  *
871  * Return the matched index if the system is found in the platform list.
872  * Otherwise, return a negative error code.
873  */
874 int acpi_match_platform_list(const struct acpi_platform_list *plat)
875 {
876         struct acpi_table_header hdr;
877         int idx = 0;
878
879         if (acpi_disabled)
880                 return -ENODEV;
881
882         for (; plat->oem_id[0]; plat++, idx++) {
883                 if (ACPI_FAILURE(acpi_get_table_header(plat->table, 0, &hdr)))
884                         continue;
885
886                 if (strncmp(plat->oem_id, hdr.oem_id, ACPI_OEM_ID_SIZE))
887                         continue;
888
889                 if (strncmp(plat->oem_table_id, hdr.oem_table_id, ACPI_OEM_TABLE_ID_SIZE))
890                         continue;
891
892                 if ((plat->pred == all_versions) ||
893                     (plat->pred == less_than_or_equal && hdr.oem_revision <= plat->oem_revision) ||
894                     (plat->pred == greater_than_or_equal && hdr.oem_revision >= plat->oem_revision) ||
895                     (plat->pred == equal && hdr.oem_revision == plat->oem_revision))
896                         return idx;
897         }
898
899         return -ENODEV;
900 }
901 EXPORT_SYMBOL(acpi_match_platform_list);