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1/*
2 * ACPI-WMI mapping driver
3 *
4 * Copyright (C) 2007-2008 Carlos Corbacho <carlos@strangeworlds.co.uk>
5 *
6 * GUID parsing code from ldm.c is:
7 * Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
8 * Copyright (c) 2001-2007 Anton Altaparmakov
9 * Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
10 *
11 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
12 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or (at
16 * your option) any later version.
17 *
18 * This program is distributed in the hope that it will be useful, but
19 * WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
21 * General Public License for more details.
22 *
23 * You should have received a copy of the GNU General Public License along
24 * with this program; if not, write to the Free Software Foundation, Inc.,
25 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
26 *
27 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
28 */
29
30#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
31
32#include <linux/kernel.h>
33#include <linux/init.h>
34#include <linux/types.h>
35#include <linux/device.h>
36#include <linux/list.h>
37#include <linux/acpi.h>
38#include <linux/slab.h>
39#include <linux/module.h>
40
41ACPI_MODULE_NAME("wmi");
42MODULE_AUTHOR("Carlos Corbacho");
43MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
44MODULE_LICENSE("GPL");
45
46#define ACPI_WMI_CLASS "wmi"
47
48static LIST_HEAD(wmi_block_list);
49
50struct guid_block {
51 char guid[16];
52 union {
53 char object_id[2];
54 struct {
55 unsigned char notify_id;
56 unsigned char reserved;
57 };
58 };
59 u8 instance_count;
60 u8 flags;
61};
62
63struct wmi_block {
64 struct list_head list;
65 struct guid_block gblock;
66 acpi_handle handle;
67 wmi_notify_handler handler;
68 void *handler_data;
69 struct device dev;
70};
71
72
73/*
74 * If the GUID data block is marked as expensive, we must enable and
75 * explicitily disable data collection.
76 */
77#define ACPI_WMI_EXPENSIVE 0x1
78#define ACPI_WMI_METHOD 0x2 /* GUID is a method */
79#define ACPI_WMI_STRING 0x4 /* GUID takes & returns a string */
80#define ACPI_WMI_EVENT 0x8 /* GUID is an event */
81
82static bool debug_event;
83module_param(debug_event, bool, 0444);
84MODULE_PARM_DESC(debug_event,
85 "Log WMI Events [0/1]");
86
87static bool debug_dump_wdg;
88module_param(debug_dump_wdg, bool, 0444);
89MODULE_PARM_DESC(debug_dump_wdg,
90 "Dump available WMI interfaces [0/1]");
91
92static int acpi_wmi_remove(struct acpi_device *device);
93static int acpi_wmi_add(struct acpi_device *device);
94static void acpi_wmi_notify(struct acpi_device *device, u32 event);
95
96static const struct acpi_device_id wmi_device_ids[] = {
97 {"PNP0C14", 0},
98 {"pnp0c14", 0},
99 {"", 0},
100};
101MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
102
103static struct acpi_driver acpi_wmi_driver = {
104 .name = "wmi",
105 .class = ACPI_WMI_CLASS,
106 .ids = wmi_device_ids,
107 .ops = {
108 .add = acpi_wmi_add,
109 .remove = acpi_wmi_remove,
110 .notify = acpi_wmi_notify,
111 },
112};
113
114/*
115 * GUID parsing functions
116 */
117
118/**
119 * wmi_parse_hexbyte - Convert a ASCII hex number to a byte
120 * @src: Pointer to at least 2 characters to convert.
121 *
122 * Convert a two character ASCII hex string to a number.
123 *
124 * Return: 0-255 Success, the byte was parsed correctly
125 * -1 Error, an invalid character was supplied
126 */
127static int wmi_parse_hexbyte(const u8 *src)
128{
129 int h;
130 int value;
131
132 /* high part */
133 h = value = hex_to_bin(src[0]);
134 if (value < 0)
135 return -1;
136
137 /* low part */
138 value = hex_to_bin(src[1]);
139 if (value >= 0)
140 return (h << 4) | value;
141 return -1;
142}
143
144/**
145 * wmi_swap_bytes - Rearrange GUID bytes to match GUID binary
146 * @src: Memory block holding binary GUID (16 bytes)
147 * @dest: Memory block to hold byte swapped binary GUID (16 bytes)
148 *
149 * Byte swap a binary GUID to match it's real GUID value
150 */
151static void wmi_swap_bytes(u8 *src, u8 *dest)
152{
153 int i;
154
155 for (i = 0; i <= 3; i++)
156 memcpy(dest + i, src + (3 - i), 1);
157
158 for (i = 0; i <= 1; i++)
159 memcpy(dest + 4 + i, src + (5 - i), 1);
160
161 for (i = 0; i <= 1; i++)
162 memcpy(dest + 6 + i, src + (7 - i), 1);
163
164 memcpy(dest + 8, src + 8, 8);
165}
166
167/**
168 * wmi_parse_guid - Convert GUID from ASCII to binary
169 * @src: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
170 * @dest: Memory block to hold binary GUID (16 bytes)
171 *
172 * N.B. The GUID need not be NULL terminated.
173 *
174 * Return: 'true' @dest contains binary GUID
175 * 'false' @dest contents are undefined
176 */
177static bool wmi_parse_guid(const u8 *src, u8 *dest)
178{
179 static const int size[] = { 4, 2, 2, 2, 6 };
180 int i, j, v;
181
182 if (src[8] != '-' || src[13] != '-' ||
183 src[18] != '-' || src[23] != '-')
184 return false;
185
186 for (j = 0; j < 5; j++, src++) {
187 for (i = 0; i < size[j]; i++, src += 2, *dest++ = v) {
188 v = wmi_parse_hexbyte(src);
189 if (v < 0)
190 return false;
191 }
192 }
193
194 return true;
195}
196
197static bool find_guid(const char *guid_string, struct wmi_block **out)
198{
199 char tmp[16], guid_input[16];
200 struct wmi_block *wblock;
201 struct guid_block *block;
202 struct list_head *p;
203
204 wmi_parse_guid(guid_string, tmp);
205 wmi_swap_bytes(tmp, guid_input);
206
207 list_for_each(p, &wmi_block_list) {
208 wblock = list_entry(p, struct wmi_block, list);
209 block = &wblock->gblock;
210
211 if (memcmp(block->guid, guid_input, 16) == 0) {
212 if (out)
213 *out = wblock;
214 return true;
215 }
216 }
217 return false;
218}
219
220static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable)
221{
222 struct guid_block *block = NULL;
223 char method[5];
224 acpi_status status;
225 acpi_handle handle;
226
227 block = &wblock->gblock;
228 handle = wblock->handle;
229
230 snprintf(method, 5, "WE%02X", block->notify_id);
231 status = acpi_execute_simple_method(handle, method, enable);
232
233 if (status != AE_OK && status != AE_NOT_FOUND)
234 return status;
235 else
236 return AE_OK;
237}
238
239/*
240 * Exported WMI functions
241 */
242/**
243 * wmi_evaluate_method - Evaluate a WMI method
244 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
245 * @instance: Instance index
246 * @method_id: Method ID to call
247 * &in: Buffer containing input for the method call
248 * &out: Empty buffer to return the method results
249 *
250 * Call an ACPI-WMI method
251 */
252acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
253u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
254{
255 struct guid_block *block = NULL;
256 struct wmi_block *wblock = NULL;
257 acpi_handle handle;
258 acpi_status status;
259 struct acpi_object_list input;
260 union acpi_object params[3];
261 char method[5] = "WM";
262
263 if (!find_guid(guid_string, &wblock))
264 return AE_ERROR;
265
266 block = &wblock->gblock;
267 handle = wblock->handle;
268
269 if (!(block->flags & ACPI_WMI_METHOD))
270 return AE_BAD_DATA;
271
272 if (block->instance_count < instance)
273 return AE_BAD_PARAMETER;
274
275 input.count = 2;
276 input.pointer = params;
277 params[0].type = ACPI_TYPE_INTEGER;
278 params[0].integer.value = instance;
279 params[1].type = ACPI_TYPE_INTEGER;
280 params[1].integer.value = method_id;
281
282 if (in) {
283 input.count = 3;
284
285 if (block->flags & ACPI_WMI_STRING) {
286 params[2].type = ACPI_TYPE_STRING;
287 } else {
288 params[2].type = ACPI_TYPE_BUFFER;
289 }
290 params[2].buffer.length = in->length;
291 params[2].buffer.pointer = in->pointer;
292 }
293
294 strncat(method, block->object_id, 2);
295
296 status = acpi_evaluate_object(handle, method, &input, out);
297
298 return status;
299}
300EXPORT_SYMBOL_GPL(wmi_evaluate_method);
301
302/**
303 * wmi_query_block - Return contents of a WMI block
304 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
305 * @instance: Instance index
306 * &out: Empty buffer to return the contents of the data block to
307 *
308 * Return the contents of an ACPI-WMI data block to a buffer
309 */
310acpi_status wmi_query_block(const char *guid_string, u8 instance,
311struct acpi_buffer *out)
312{
313 struct guid_block *block = NULL;
314 struct wmi_block *wblock = NULL;
315 acpi_handle handle;
316 acpi_status status, wc_status = AE_ERROR;
317 struct acpi_object_list input;
318 union acpi_object wq_params[1];
319 char method[5];
320 char wc_method[5] = "WC";
321
322 if (!guid_string || !out)
323 return AE_BAD_PARAMETER;
324
325 if (!find_guid(guid_string, &wblock))
326 return AE_ERROR;
327
328 block = &wblock->gblock;
329 handle = wblock->handle;
330
331 if (block->instance_count < instance)
332 return AE_BAD_PARAMETER;
333
334 /* Check GUID is a data block */
335 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
336 return AE_ERROR;
337
338 input.count = 1;
339 input.pointer = wq_params;
340 wq_params[0].type = ACPI_TYPE_INTEGER;
341 wq_params[0].integer.value = instance;
342
343 /*
344 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
345 * enable collection.
346 */
347 if (block->flags & ACPI_WMI_EXPENSIVE) {
348 strncat(wc_method, block->object_id, 2);
349
350 /*
351 * Some GUIDs break the specification by declaring themselves
352 * expensive, but have no corresponding WCxx method. So we
353 * should not fail if this happens.
354 */
355 if (acpi_has_method(handle, wc_method))
356 wc_status = acpi_execute_simple_method(handle,
357 wc_method, 1);
358 }
359
360 strcpy(method, "WQ");
361 strncat(method, block->object_id, 2);
362
363 status = acpi_evaluate_object(handle, method, &input, out);
364
365 /*
366 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
367 * the WQxx method failed - we should disable collection anyway.
368 */
369 if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
370 status = acpi_execute_simple_method(handle, wc_method, 0);
371 }
372
373 return status;
374}
375EXPORT_SYMBOL_GPL(wmi_query_block);
376
377/**
378 * wmi_set_block - Write to a WMI block
379 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
380 * @instance: Instance index
381 * &in: Buffer containing new values for the data block
382 *
383 * Write the contents of the input buffer to an ACPI-WMI data block
384 */
385acpi_status wmi_set_block(const char *guid_string, u8 instance,
386const struct acpi_buffer *in)
387{
388 struct guid_block *block = NULL;
389 struct wmi_block *wblock = NULL;
390 acpi_handle handle;
391 struct acpi_object_list input;
392 union acpi_object params[2];
393 char method[5] = "WS";
394
395 if (!guid_string || !in)
396 return AE_BAD_DATA;
397
398 if (!find_guid(guid_string, &wblock))
399 return AE_ERROR;
400
401 block = &wblock->gblock;
402 handle = wblock->handle;
403
404 if (block->instance_count < instance)
405 return AE_BAD_PARAMETER;
406
407 /* Check GUID is a data block */
408 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
409 return AE_ERROR;
410
411 input.count = 2;
412 input.pointer = params;
413 params[0].type = ACPI_TYPE_INTEGER;
414 params[0].integer.value = instance;
415
416 if (block->flags & ACPI_WMI_STRING) {
417 params[1].type = ACPI_TYPE_STRING;
418 } else {
419 params[1].type = ACPI_TYPE_BUFFER;
420 }
421 params[1].buffer.length = in->length;
422 params[1].buffer.pointer = in->pointer;
423
424 strncat(method, block->object_id, 2);
425
426 return acpi_evaluate_object(handle, method, &input, NULL);
427}
428EXPORT_SYMBOL_GPL(wmi_set_block);
429
430static void wmi_dump_wdg(const struct guid_block *g)
431{
432 pr_info("%pUL:\n", g->guid);
433 pr_info("\tobject_id: %c%c\n", g->object_id[0], g->object_id[1]);
434 pr_info("\tnotify_id: %02X\n", g->notify_id);
435 pr_info("\treserved: %02X\n", g->reserved);
436 pr_info("\tinstance_count: %d\n", g->instance_count);
437 pr_info("\tflags: %#x", g->flags);
438 if (g->flags) {
439 if (g->flags & ACPI_WMI_EXPENSIVE)
440 pr_cont(" ACPI_WMI_EXPENSIVE");
441 if (g->flags & ACPI_WMI_METHOD)
442 pr_cont(" ACPI_WMI_METHOD");
443 if (g->flags & ACPI_WMI_STRING)
444 pr_cont(" ACPI_WMI_STRING");
445 if (g->flags & ACPI_WMI_EVENT)
446 pr_cont(" ACPI_WMI_EVENT");
447 }
448 pr_cont("\n");
449
450}
451
452static void wmi_notify_debug(u32 value, void *context)
453{
454 struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
455 union acpi_object *obj;
456 acpi_status status;
457
458 status = wmi_get_event_data(value, &response);
459 if (status != AE_OK) {
460 pr_info("bad event status 0x%x\n", status);
461 return;
462 }
463
464 obj = (union acpi_object *)response.pointer;
465
466 if (!obj)
467 return;
468
469 pr_info("DEBUG Event ");
470 switch(obj->type) {
471 case ACPI_TYPE_BUFFER:
472 pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
473 break;
474 case ACPI_TYPE_STRING:
475 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
476 break;
477 case ACPI_TYPE_INTEGER:
478 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
479 break;
480 case ACPI_TYPE_PACKAGE:
481 pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
482 break;
483 default:
484 pr_cont("object type 0x%X\n", obj->type);
485 }
486 kfree(obj);
487}
488
489/**
490 * wmi_install_notify_handler - Register handler for WMI events
491 * @handler: Function to handle notifications
492 * @data: Data to be returned to handler when event is fired
493 *
494 * Register a handler for events sent to the ACPI-WMI mapper device.
495 */
496acpi_status wmi_install_notify_handler(const char *guid,
497wmi_notify_handler handler, void *data)
498{
499 struct wmi_block *block;
500 acpi_status status = AE_NOT_EXIST;
501 char tmp[16], guid_input[16];
502 struct list_head *p;
503
504 if (!guid || !handler)
505 return AE_BAD_PARAMETER;
506
507 wmi_parse_guid(guid, tmp);
508 wmi_swap_bytes(tmp, guid_input);
509
510 list_for_each(p, &wmi_block_list) {
511 acpi_status wmi_status;
512 block = list_entry(p, struct wmi_block, list);
513
514 if (memcmp(block->gblock.guid, guid_input, 16) == 0) {
515 if (block->handler &&
516 block->handler != wmi_notify_debug)
517 return AE_ALREADY_ACQUIRED;
518
519 block->handler = handler;
520 block->handler_data = data;
521
522 wmi_status = wmi_method_enable(block, 1);
523 if ((wmi_status != AE_OK) ||
524 ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
525 status = wmi_status;
526 }
527 }
528
529 return status;
530}
531EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
532
533/**
534 * wmi_uninstall_notify_handler - Unregister handler for WMI events
535 *
536 * Unregister handler for events sent to the ACPI-WMI mapper device.
537 */
538acpi_status wmi_remove_notify_handler(const char *guid)
539{
540 struct wmi_block *block;
541 acpi_status status = AE_NOT_EXIST;
542 char tmp[16], guid_input[16];
543 struct list_head *p;
544
545 if (!guid)
546 return AE_BAD_PARAMETER;
547
548 wmi_parse_guid(guid, tmp);
549 wmi_swap_bytes(tmp, guid_input);
550
551 list_for_each(p, &wmi_block_list) {
552 acpi_status wmi_status;
553 block = list_entry(p, struct wmi_block, list);
554
555 if (memcmp(block->gblock.guid, guid_input, 16) == 0) {
556 if (!block->handler ||
557 block->handler == wmi_notify_debug)
558 return AE_NULL_ENTRY;
559
560 if (debug_event) {
561 block->handler = wmi_notify_debug;
562 status = AE_OK;
563 } else {
564 wmi_status = wmi_method_enable(block, 0);
565 block->handler = NULL;
566 block->handler_data = NULL;
567 if ((wmi_status != AE_OK) ||
568 ((wmi_status == AE_OK) &&
569 (status == AE_NOT_EXIST)))
570 status = wmi_status;
571 }
572 }
573 }
574
575 return status;
576}
577EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
578
579/**
580 * wmi_get_event_data - Get WMI data associated with an event
581 *
582 * @event: Event to find
583 * @out: Buffer to hold event data. out->pointer should be freed with kfree()
584 *
585 * Returns extra data associated with an event in WMI.
586 */
587acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
588{
589 struct acpi_object_list input;
590 union acpi_object params[1];
591 struct guid_block *gblock;
592 struct wmi_block *wblock;
593 struct list_head *p;
594
595 input.count = 1;
596 input.pointer = params;
597 params[0].type = ACPI_TYPE_INTEGER;
598 params[0].integer.value = event;
599
600 list_for_each(p, &wmi_block_list) {
601 wblock = list_entry(p, struct wmi_block, list);
602 gblock = &wblock->gblock;
603
604 if ((gblock->flags & ACPI_WMI_EVENT) &&
605 (gblock->notify_id == event))
606 return acpi_evaluate_object(wblock->handle, "_WED",
607 &input, out);
608 }
609
610 return AE_NOT_FOUND;
611}
612EXPORT_SYMBOL_GPL(wmi_get_event_data);
613
614/**
615 * wmi_has_guid - Check if a GUID is available
616 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
617 *
618 * Check if a given GUID is defined by _WDG
619 */
620bool wmi_has_guid(const char *guid_string)
621{
622 return find_guid(guid_string, NULL);
623}
624EXPORT_SYMBOL_GPL(wmi_has_guid);
625
626/*
627 * sysfs interface
628 */
629static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
630 char *buf)
631{
632 struct wmi_block *wblock;
633
634 wblock = dev_get_drvdata(dev);
635 if (!wblock) {
636 strcat(buf, "\n");
637 return strlen(buf);
638 }
639
640 return sprintf(buf, "wmi:%pUL\n", wblock->gblock.guid);
641}
642static DEVICE_ATTR_RO(modalias);
643
644static struct attribute *wmi_attrs[] = {
645 &dev_attr_modalias.attr,
646 NULL,
647};
648ATTRIBUTE_GROUPS(wmi);
649
650static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
651{
652 char guid_string[37];
653
654 struct wmi_block *wblock;
655
656 if (add_uevent_var(env, "MODALIAS="))
657 return -ENOMEM;
658
659 wblock = dev_get_drvdata(dev);
660 if (!wblock)
661 return -ENOMEM;
662
663 sprintf(guid_string, "%pUL", wblock->gblock.guid);
664
665 strcpy(&env->buf[env->buflen - 1], "wmi:");
666 memcpy(&env->buf[env->buflen - 1 + 4], guid_string, 36);
667 env->buflen += 40;
668
669 return 0;
670}
671
672static void wmi_dev_free(struct device *dev)
673{
674 struct wmi_block *wmi_block = container_of(dev, struct wmi_block, dev);
675
676 kfree(wmi_block);
677}
678
679static struct class wmi_class = {
680 .name = "wmi",
681 .dev_release = wmi_dev_free,
682 .dev_uevent = wmi_dev_uevent,
683 .dev_groups = wmi_groups,
684};
685
686static int wmi_create_device(const struct guid_block *gblock,
687 struct wmi_block *wblock, acpi_handle handle)
688{
689 wblock->dev.class = &wmi_class;
690
691 dev_set_name(&wblock->dev, "%pUL", gblock->guid);
692
693 dev_set_drvdata(&wblock->dev, wblock);
694
695 return device_register(&wblock->dev);
696}
697
698static void wmi_free_devices(void)
699{
700 struct wmi_block *wblock, *next;
701
702 /* Delete devices for all the GUIDs */
703 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
704 list_del(&wblock->list);
705 if (wblock->dev.class)
706 device_unregister(&wblock->dev);
707 else
708 kfree(wblock);
709 }
710}
711
712static bool guid_already_parsed(const char *guid_string)
713{
714 struct wmi_block *wblock;
715
716 list_for_each_entry(wblock, &wmi_block_list, list)
717 if (memcmp(wblock->gblock.guid, guid_string, 16) == 0)
718 return true;
719
720 return false;
721}
722
723/*
724 * Parse the _WDG method for the GUID data blocks
725 */
726static int parse_wdg(acpi_handle handle)
727{
728 struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
729 union acpi_object *obj;
730 const struct guid_block *gblock;
731 struct wmi_block *wblock;
732 acpi_status status;
733 int retval;
734 u32 i, total;
735
736 status = acpi_evaluate_object(handle, "_WDG", NULL, &out);
737 if (ACPI_FAILURE(status))
738 return -ENXIO;
739
740 obj = (union acpi_object *) out.pointer;
741 if (!obj)
742 return -ENXIO;
743
744 if (obj->type != ACPI_TYPE_BUFFER) {
745 retval = -ENXIO;
746 goto out_free_pointer;
747 }
748
749 gblock = (const struct guid_block *)obj->buffer.pointer;
750 total = obj->buffer.length / sizeof(struct guid_block);
751
752 for (i = 0; i < total; i++) {
753 if (debug_dump_wdg)
754 wmi_dump_wdg(&gblock[i]);
755
756 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
757 if (!wblock)
758 return -ENOMEM;
759
760 wblock->handle = handle;
761 wblock->gblock = gblock[i];
762
763 /*
764 Some WMI devices, like those for nVidia hooks, have a
765 duplicate GUID. It's not clear what we should do in this
766 case yet, so for now, we'll just ignore the duplicate
767 for device creation.
768 */
769 if (!guid_already_parsed(gblock[i].guid)) {
770 retval = wmi_create_device(&gblock[i], wblock, handle);
771 if (retval) {
772 wmi_free_devices();
773 goto out_free_pointer;
774 }
775 }
776
777 list_add_tail(&wblock->list, &wmi_block_list);
778
779 if (debug_event) {
780 wblock->handler = wmi_notify_debug;
781 wmi_method_enable(wblock, 1);
782 }
783 }
784
785 retval = 0;
786
787out_free_pointer:
788 kfree(out.pointer);
789
790 return retval;
791}
792
793/*
794 * WMI can have EmbeddedControl access regions. In which case, we just want to
795 * hand these off to the EC driver.
796 */
797static acpi_status
798acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
799 u32 bits, u64 *value,
800 void *handler_context, void *region_context)
801{
802 int result = 0, i = 0;
803 u8 temp = 0;
804
805 if ((address > 0xFF) || !value)
806 return AE_BAD_PARAMETER;
807
808 if (function != ACPI_READ && function != ACPI_WRITE)
809 return AE_BAD_PARAMETER;
810
811 if (bits != 8)
812 return AE_BAD_PARAMETER;
813
814 if (function == ACPI_READ) {
815 result = ec_read(address, &temp);
816 (*value) |= ((u64)temp) << i;
817 } else {
818 temp = 0xff & ((*value) >> i);
819 result = ec_write(address, temp);
820 }
821
822 switch (result) {
823 case -EINVAL:
824 return AE_BAD_PARAMETER;
825 break;
826 case -ENODEV:
827 return AE_NOT_FOUND;
828 break;
829 case -ETIME:
830 return AE_TIME;
831 break;
832 default:
833 return AE_OK;
834 }
835}
836
837static void acpi_wmi_notify(struct acpi_device *device, u32 event)
838{
839 struct guid_block *block;
840 struct wmi_block *wblock;
841 struct list_head *p;
842
843 list_for_each(p, &wmi_block_list) {
844 wblock = list_entry(p, struct wmi_block, list);
845 block = &wblock->gblock;
846
847 if ((block->flags & ACPI_WMI_EVENT) &&
848 (block->notify_id == event)) {
849 if (wblock->handler)
850 wblock->handler(event, wblock->handler_data);
851 if (debug_event) {
852 pr_info("DEBUG Event GUID: %pUL\n",
853 wblock->gblock.guid);
854 }
855
856 acpi_bus_generate_netlink_event(
857 device->pnp.device_class, dev_name(&device->dev),
858 event, 0);
859 break;
860 }
861 }
862}
863
864static int acpi_wmi_remove(struct acpi_device *device)
865{
866 acpi_remove_address_space_handler(device->handle,
867 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
868 wmi_free_devices();
869
870 return 0;
871}
872
873static int acpi_wmi_add(struct acpi_device *device)
874{
875 acpi_status status;
876 int error;
877
878 status = acpi_install_address_space_handler(device->handle,
879 ACPI_ADR_SPACE_EC,
880 &acpi_wmi_ec_space_handler,
881 NULL, NULL);
882 if (ACPI_FAILURE(status)) {
883 pr_err("Error installing EC region handler\n");
884 return -ENODEV;
885 }
886
887 error = parse_wdg(device->handle);
888 if (error) {
889 acpi_remove_address_space_handler(device->handle,
890 ACPI_ADR_SPACE_EC,
891 &acpi_wmi_ec_space_handler);
892 pr_err("Failed to parse WDG method\n");
893 return error;
894 }
895
896 return 0;
897}
898
899static int __init acpi_wmi_init(void)
900{
901 int error;
902
903 if (acpi_disabled)
904 return -ENODEV;
905
906 error = class_register(&wmi_class);
907 if (error)
908 return error;
909
910 error = acpi_bus_register_driver(&acpi_wmi_driver);
911 if (error) {
912 pr_err("Error loading mapper\n");
913 class_unregister(&wmi_class);
914 return error;
915 }
916
917 pr_info("Mapper loaded\n");
918 return 0;
919}
920
921static void __exit acpi_wmi_exit(void)
922{
923 acpi_bus_unregister_driver(&acpi_wmi_driver);
924 class_unregister(&wmi_class);
925
926 pr_info("Mapper unloaded\n");
927}
928
929subsys_initcall(acpi_wmi_init);
930module_exit(acpi_wmi_exit);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * ACPI-WMI mapping driver
4 *
5 * Copyright (C) 2007-2008 Carlos Corbacho <carlos@strangeworlds.co.uk>
6 *
7 * GUID parsing code from ldm.c is:
8 * Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
9 * Copyright (c) 2001-2007 Anton Altaparmakov
10 * Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
11 *
12 * WMI bus infrastructure by Andrew Lutomirski and Darren Hart:
13 * Copyright (C) 2015 Andrew Lutomirski
14 * Copyright (C) 2017 VMware, Inc. All Rights Reserved.
15 */
16
17#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18
19#include <linux/acpi.h>
20#include <linux/bits.h>
21#include <linux/build_bug.h>
22#include <linux/device.h>
23#include <linux/init.h>
24#include <linux/kernel.h>
25#include <linux/module.h>
26#include <linux/platform_device.h>
27#include <linux/rwsem.h>
28#include <linux/slab.h>
29#include <linux/sysfs.h>
30#include <linux/types.h>
31#include <linux/uuid.h>
32#include <linux/wmi.h>
33#include <linux/fs.h>
34
35MODULE_AUTHOR("Carlos Corbacho");
36MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
37MODULE_LICENSE("GPL");
38
39struct guid_block {
40 guid_t guid;
41 union {
42 char object_id[2];
43 struct {
44 unsigned char notify_id;
45 unsigned char reserved;
46 };
47 };
48 u8 instance_count;
49 u8 flags;
50} __packed;
51static_assert(sizeof(typeof_member(struct guid_block, guid)) == 16);
52static_assert(sizeof(struct guid_block) == 20);
53static_assert(__alignof__(struct guid_block) == 1);
54
55enum { /* wmi_block flags */
56 WMI_READ_TAKES_NO_ARGS,
57 WMI_GUID_DUPLICATED,
58 WMI_NO_EVENT_DATA,
59};
60
61struct wmi_block {
62 struct wmi_device dev;
63 struct guid_block gblock;
64 struct acpi_device *acpi_device;
65 struct rw_semaphore notify_lock; /* Protects notify callback add/remove */
66 wmi_notify_handler handler;
67 void *handler_data;
68 bool driver_ready;
69 unsigned long flags;
70};
71
72struct wmi_guid_count_context {
73 const guid_t *guid;
74 int count;
75};
76
77/*
78 * If the GUID data block is marked as expensive, we must enable and
79 * explicitily disable data collection.
80 */
81#define ACPI_WMI_EXPENSIVE BIT(0)
82#define ACPI_WMI_METHOD BIT(1) /* GUID is a method */
83#define ACPI_WMI_STRING BIT(2) /* GUID takes & returns a string */
84#define ACPI_WMI_EVENT BIT(3) /* GUID is an event */
85
86static const struct acpi_device_id wmi_device_ids[] = {
87 {"PNP0C14", 0},
88 {"pnp0c14", 0},
89 { }
90};
91MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
92
93#define dev_to_wblock(__dev) container_of_const(__dev, struct wmi_block, dev.dev)
94
95/*
96 * GUID parsing functions
97 */
98
99static bool guid_parse_and_compare(const char *string, const guid_t *guid)
100{
101 guid_t guid_input;
102
103 if (guid_parse(string, &guid_input))
104 return false;
105
106 return guid_equal(&guid_input, guid);
107}
108
109static const void *find_guid_context(struct wmi_block *wblock,
110 struct wmi_driver *wdriver)
111{
112 const struct wmi_device_id *id;
113
114 id = wdriver->id_table;
115 if (!id)
116 return NULL;
117
118 while (*id->guid_string) {
119 if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid))
120 return id->context;
121 id++;
122 }
123 return NULL;
124}
125
126static acpi_status wmi_method_enable(struct wmi_block *wblock, bool enable)
127{
128 struct guid_block *block;
129 char method[5];
130 acpi_status status;
131 acpi_handle handle;
132
133 block = &wblock->gblock;
134 handle = wblock->acpi_device->handle;
135
136 snprintf(method, 5, "WE%02X", block->notify_id);
137 status = acpi_execute_simple_method(handle, method, enable);
138 if (status == AE_NOT_FOUND)
139 return AE_OK;
140
141 return status;
142}
143
144#define WMI_ACPI_METHOD_NAME_SIZE 5
145
146static inline void get_acpi_method_name(const struct wmi_block *wblock,
147 const char method,
148 char buffer[static WMI_ACPI_METHOD_NAME_SIZE])
149{
150 static_assert(ARRAY_SIZE(wblock->gblock.object_id) == 2);
151 static_assert(WMI_ACPI_METHOD_NAME_SIZE >= 5);
152
153 buffer[0] = 'W';
154 buffer[1] = method;
155 buffer[2] = wblock->gblock.object_id[0];
156 buffer[3] = wblock->gblock.object_id[1];
157 buffer[4] = '\0';
158}
159
160static inline acpi_object_type get_param_acpi_type(const struct wmi_block *wblock)
161{
162 if (wblock->gblock.flags & ACPI_WMI_STRING)
163 return ACPI_TYPE_STRING;
164 else
165 return ACPI_TYPE_BUFFER;
166}
167
168static int wmidev_match_guid(struct device *dev, const void *data)
169{
170 struct wmi_block *wblock = dev_to_wblock(dev);
171 const guid_t *guid = data;
172
173 /* Legacy GUID-based functions are restricted to only see
174 * a single WMI device for each GUID.
175 */
176 if (test_bit(WMI_GUID_DUPLICATED, &wblock->flags))
177 return 0;
178
179 if (guid_equal(guid, &wblock->gblock.guid))
180 return 1;
181
182 return 0;
183}
184
185static const struct bus_type wmi_bus_type;
186
187static struct wmi_device *wmi_find_device_by_guid(const char *guid_string)
188{
189 struct device *dev;
190 guid_t guid;
191 int ret;
192
193 ret = guid_parse(guid_string, &guid);
194 if (ret < 0)
195 return ERR_PTR(ret);
196
197 dev = bus_find_device(&wmi_bus_type, NULL, &guid, wmidev_match_guid);
198 if (!dev)
199 return ERR_PTR(-ENODEV);
200
201 return to_wmi_device(dev);
202}
203
204static void wmi_device_put(struct wmi_device *wdev)
205{
206 put_device(&wdev->dev);
207}
208
209/*
210 * Exported WMI functions
211 */
212
213/**
214 * wmi_instance_count - Get number of WMI object instances
215 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
216 *
217 * Get the number of WMI object instances.
218 *
219 * Returns: Number of WMI object instances or negative error code.
220 */
221int wmi_instance_count(const char *guid_string)
222{
223 struct wmi_device *wdev;
224 int ret;
225
226 wdev = wmi_find_device_by_guid(guid_string);
227 if (IS_ERR(wdev))
228 return PTR_ERR(wdev);
229
230 ret = wmidev_instance_count(wdev);
231 wmi_device_put(wdev);
232
233 return ret;
234}
235EXPORT_SYMBOL_GPL(wmi_instance_count);
236
237/**
238 * wmidev_instance_count - Get number of WMI object instances
239 * @wdev: A wmi bus device from a driver
240 *
241 * Get the number of WMI object instances.
242 *
243 * Returns: Number of WMI object instances.
244 */
245u8 wmidev_instance_count(struct wmi_device *wdev)
246{
247 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
248
249 return wblock->gblock.instance_count;
250}
251EXPORT_SYMBOL_GPL(wmidev_instance_count);
252
253/**
254 * wmi_evaluate_method - Evaluate a WMI method (deprecated)
255 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
256 * @instance: Instance index
257 * @method_id: Method ID to call
258 * @in: Mandatory buffer containing input for the method call
259 * @out: Empty buffer to return the method results
260 *
261 * Call an ACPI-WMI method, the caller must free @out.
262 *
263 * Return: acpi_status signaling success or error.
264 */
265acpi_status wmi_evaluate_method(const char *guid_string, u8 instance, u32 method_id,
266 const struct acpi_buffer *in, struct acpi_buffer *out)
267{
268 struct wmi_device *wdev;
269 acpi_status status;
270
271 wdev = wmi_find_device_by_guid(guid_string);
272 if (IS_ERR(wdev))
273 return AE_ERROR;
274
275 status = wmidev_evaluate_method(wdev, instance, method_id, in, out);
276
277 wmi_device_put(wdev);
278
279 return status;
280}
281EXPORT_SYMBOL_GPL(wmi_evaluate_method);
282
283/**
284 * wmidev_evaluate_method - Evaluate a WMI method
285 * @wdev: A wmi bus device from a driver
286 * @instance: Instance index
287 * @method_id: Method ID to call
288 * @in: Mandatory buffer containing input for the method call
289 * @out: Empty buffer to return the method results
290 *
291 * Call an ACPI-WMI method, the caller must free @out.
292 *
293 * Return: acpi_status signaling success or error.
294 */
295acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance, u32 method_id,
296 const struct acpi_buffer *in, struct acpi_buffer *out)
297{
298 struct guid_block *block;
299 struct wmi_block *wblock;
300 acpi_handle handle;
301 struct acpi_object_list input;
302 union acpi_object params[3];
303 char method[WMI_ACPI_METHOD_NAME_SIZE];
304
305 wblock = container_of(wdev, struct wmi_block, dev);
306 block = &wblock->gblock;
307 handle = wblock->acpi_device->handle;
308
309 if (!in)
310 return AE_BAD_DATA;
311
312 if (!(block->flags & ACPI_WMI_METHOD))
313 return AE_BAD_DATA;
314
315 if (block->instance_count <= instance)
316 return AE_BAD_PARAMETER;
317
318 input.count = 3;
319 input.pointer = params;
320
321 params[0].type = ACPI_TYPE_INTEGER;
322 params[0].integer.value = instance;
323 params[1].type = ACPI_TYPE_INTEGER;
324 params[1].integer.value = method_id;
325 params[2].type = get_param_acpi_type(wblock);
326 params[2].buffer.length = in->length;
327 params[2].buffer.pointer = in->pointer;
328
329 get_acpi_method_name(wblock, 'M', method);
330
331 return acpi_evaluate_object(handle, method, &input, out);
332}
333EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
334
335static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
336 struct acpi_buffer *out)
337{
338 struct guid_block *block;
339 acpi_handle handle;
340 acpi_status status, wc_status = AE_ERROR;
341 struct acpi_object_list input;
342 union acpi_object wq_params[1];
343 char wc_method[WMI_ACPI_METHOD_NAME_SIZE];
344 char method[WMI_ACPI_METHOD_NAME_SIZE];
345
346 if (!out)
347 return AE_BAD_PARAMETER;
348
349 block = &wblock->gblock;
350 handle = wblock->acpi_device->handle;
351
352 if (block->instance_count <= instance)
353 return AE_BAD_PARAMETER;
354
355 /* Check GUID is a data block */
356 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
357 return AE_ERROR;
358
359 input.count = 1;
360 input.pointer = wq_params;
361 wq_params[0].type = ACPI_TYPE_INTEGER;
362 wq_params[0].integer.value = instance;
363
364 if (instance == 0 && test_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags))
365 input.count = 0;
366
367 /*
368 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
369 * enable collection.
370 */
371 if (block->flags & ACPI_WMI_EXPENSIVE) {
372 get_acpi_method_name(wblock, 'C', wc_method);
373
374 /*
375 * Some GUIDs break the specification by declaring themselves
376 * expensive, but have no corresponding WCxx method. So we
377 * should not fail if this happens.
378 */
379 wc_status = acpi_execute_simple_method(handle, wc_method, 1);
380 }
381
382 get_acpi_method_name(wblock, 'Q', method);
383 status = acpi_evaluate_object(handle, method, &input, out);
384
385 /*
386 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
387 * the WQxx method failed - we should disable collection anyway.
388 */
389 if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
390 /*
391 * Ignore whether this WCxx call succeeds or not since
392 * the previously executed WQxx method call might have
393 * succeeded, and returning the failing status code
394 * of this call would throw away the result of the WQxx
395 * call, potentially leaking memory.
396 */
397 acpi_execute_simple_method(handle, wc_method, 0);
398 }
399
400 return status;
401}
402
403/**
404 * wmi_query_block - Return contents of a WMI block (deprecated)
405 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
406 * @instance: Instance index
407 * @out: Empty buffer to return the contents of the data block to
408 *
409 * Query a ACPI-WMI block, the caller must free @out.
410 *
411 * Return: ACPI object containing the content of the WMI block.
412 */
413acpi_status wmi_query_block(const char *guid_string, u8 instance,
414 struct acpi_buffer *out)
415{
416 struct wmi_block *wblock;
417 struct wmi_device *wdev;
418 acpi_status status;
419
420 wdev = wmi_find_device_by_guid(guid_string);
421 if (IS_ERR(wdev))
422 return AE_ERROR;
423
424 wblock = container_of(wdev, struct wmi_block, dev);
425 status = __query_block(wblock, instance, out);
426
427 wmi_device_put(wdev);
428
429 return status;
430}
431EXPORT_SYMBOL_GPL(wmi_query_block);
432
433/**
434 * wmidev_block_query - Return contents of a WMI block
435 * @wdev: A wmi bus device from a driver
436 * @instance: Instance index
437 *
438 * Query an ACPI-WMI block, the caller must free the result.
439 *
440 * Return: ACPI object containing the content of the WMI block.
441 */
442union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
443{
444 struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
445 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
446
447 if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
448 return NULL;
449
450 return out.pointer;
451}
452EXPORT_SYMBOL_GPL(wmidev_block_query);
453
454/**
455 * wmi_set_block - Write to a WMI block (deprecated)
456 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
457 * @instance: Instance index
458 * @in: Buffer containing new values for the data block
459 *
460 * Write the contents of the input buffer to an ACPI-WMI data block.
461 *
462 * Return: acpi_status signaling success or error.
463 */
464acpi_status wmi_set_block(const char *guid_string, u8 instance, const struct acpi_buffer *in)
465{
466 struct wmi_device *wdev;
467 acpi_status status;
468
469 wdev = wmi_find_device_by_guid(guid_string);
470 if (IS_ERR(wdev))
471 return AE_ERROR;
472
473 status = wmidev_block_set(wdev, instance, in);
474 wmi_device_put(wdev);
475
476 return status;
477}
478EXPORT_SYMBOL_GPL(wmi_set_block);
479
480/**
481 * wmidev_block_set - Write to a WMI block
482 * @wdev: A wmi bus device from a driver
483 * @instance: Instance index
484 * @in: Buffer containing new values for the data block
485 *
486 * Write contents of the input buffer to an ACPI-WMI data block.
487 *
488 * Return: acpi_status signaling success or error.
489 */
490acpi_status wmidev_block_set(struct wmi_device *wdev, u8 instance, const struct acpi_buffer *in)
491{
492 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
493 acpi_handle handle = wblock->acpi_device->handle;
494 struct guid_block *block = &wblock->gblock;
495 char method[WMI_ACPI_METHOD_NAME_SIZE];
496 struct acpi_object_list input;
497 union acpi_object params[2];
498
499 if (!in)
500 return AE_BAD_DATA;
501
502 if (block->instance_count <= instance)
503 return AE_BAD_PARAMETER;
504
505 /* Check GUID is a data block */
506 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
507 return AE_ERROR;
508
509 input.count = 2;
510 input.pointer = params;
511 params[0].type = ACPI_TYPE_INTEGER;
512 params[0].integer.value = instance;
513 params[1].type = get_param_acpi_type(wblock);
514 params[1].buffer.length = in->length;
515 params[1].buffer.pointer = in->pointer;
516
517 get_acpi_method_name(wblock, 'S', method);
518
519 return acpi_evaluate_object(handle, method, &input, NULL);
520}
521EXPORT_SYMBOL_GPL(wmidev_block_set);
522
523/**
524 * wmi_install_notify_handler - Register handler for WMI events (deprecated)
525 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
526 * @handler: Function to handle notifications
527 * @data: Data to be returned to handler when event is fired
528 *
529 * Register a handler for events sent to the ACPI-WMI mapper device.
530 *
531 * Return: acpi_status signaling success or error.
532 */
533acpi_status wmi_install_notify_handler(const char *guid,
534 wmi_notify_handler handler,
535 void *data)
536{
537 struct wmi_block *wblock;
538 struct wmi_device *wdev;
539 acpi_status status;
540
541 wdev = wmi_find_device_by_guid(guid);
542 if (IS_ERR(wdev))
543 return AE_ERROR;
544
545 wblock = container_of(wdev, struct wmi_block, dev);
546
547 down_write(&wblock->notify_lock);
548 if (wblock->handler) {
549 status = AE_ALREADY_ACQUIRED;
550 } else {
551 wblock->handler = handler;
552 wblock->handler_data = data;
553
554 if (ACPI_FAILURE(wmi_method_enable(wblock, true)))
555 dev_warn(&wblock->dev.dev, "Failed to enable device\n");
556
557 status = AE_OK;
558 }
559 up_write(&wblock->notify_lock);
560
561 wmi_device_put(wdev);
562
563 return status;
564}
565EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
566
567/**
568 * wmi_remove_notify_handler - Unregister handler for WMI events (deprecated)
569 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
570 *
571 * Unregister handler for events sent to the ACPI-WMI mapper device.
572 *
573 * Return: acpi_status signaling success or error.
574 */
575acpi_status wmi_remove_notify_handler(const char *guid)
576{
577 struct wmi_block *wblock;
578 struct wmi_device *wdev;
579 acpi_status status;
580
581 wdev = wmi_find_device_by_guid(guid);
582 if (IS_ERR(wdev))
583 return AE_ERROR;
584
585 wblock = container_of(wdev, struct wmi_block, dev);
586
587 down_write(&wblock->notify_lock);
588 if (!wblock->handler) {
589 status = AE_NULL_ENTRY;
590 } else {
591 if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
592 dev_warn(&wblock->dev.dev, "Failed to disable device\n");
593
594 wblock->handler = NULL;
595 wblock->handler_data = NULL;
596
597 status = AE_OK;
598 }
599 up_write(&wblock->notify_lock);
600
601 wmi_device_put(wdev);
602
603 return status;
604}
605EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
606
607/**
608 * wmi_has_guid - Check if a GUID is available
609 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
610 *
611 * Check if a given GUID is defined by _WDG.
612 *
613 * Return: True if GUID is available, false otherwise.
614 */
615bool wmi_has_guid(const char *guid_string)
616{
617 struct wmi_device *wdev;
618
619 wdev = wmi_find_device_by_guid(guid_string);
620 if (IS_ERR(wdev))
621 return false;
622
623 wmi_device_put(wdev);
624
625 return true;
626}
627EXPORT_SYMBOL_GPL(wmi_has_guid);
628
629/**
630 * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID (deprecated)
631 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
632 *
633 * Find the _UID of ACPI device associated with this WMI GUID.
634 *
635 * Return: The ACPI _UID field value or NULL if the WMI GUID was not found.
636 */
637char *wmi_get_acpi_device_uid(const char *guid_string)
638{
639 struct wmi_block *wblock;
640 struct wmi_device *wdev;
641 char *uid;
642
643 wdev = wmi_find_device_by_guid(guid_string);
644 if (IS_ERR(wdev))
645 return NULL;
646
647 wblock = container_of(wdev, struct wmi_block, dev);
648 uid = acpi_device_uid(wblock->acpi_device);
649
650 wmi_device_put(wdev);
651
652 return uid;
653}
654EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
655
656/*
657 * sysfs interface
658 */
659static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
660 char *buf)
661{
662 struct wmi_block *wblock = dev_to_wblock(dev);
663
664 return sysfs_emit(buf, "wmi:%pUL\n", &wblock->gblock.guid);
665}
666static DEVICE_ATTR_RO(modalias);
667
668static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
669 char *buf)
670{
671 struct wmi_block *wblock = dev_to_wblock(dev);
672
673 return sysfs_emit(buf, "%pUL\n", &wblock->gblock.guid);
674}
675static DEVICE_ATTR_RO(guid);
676
677static ssize_t instance_count_show(struct device *dev,
678 struct device_attribute *attr, char *buf)
679{
680 struct wmi_block *wblock = dev_to_wblock(dev);
681
682 return sysfs_emit(buf, "%d\n", (int)wblock->gblock.instance_count);
683}
684static DEVICE_ATTR_RO(instance_count);
685
686static ssize_t expensive_show(struct device *dev,
687 struct device_attribute *attr, char *buf)
688{
689 struct wmi_block *wblock = dev_to_wblock(dev);
690
691 return sysfs_emit(buf, "%d\n",
692 (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
693}
694static DEVICE_ATTR_RO(expensive);
695
696static ssize_t driver_override_show(struct device *dev, struct device_attribute *attr,
697 char *buf)
698{
699 struct wmi_device *wdev = to_wmi_device(dev);
700 ssize_t ret;
701
702 device_lock(dev);
703 ret = sysfs_emit(buf, "%s\n", wdev->driver_override);
704 device_unlock(dev);
705
706 return ret;
707}
708
709static ssize_t driver_override_store(struct device *dev, struct device_attribute *attr,
710 const char *buf, size_t count)
711{
712 struct wmi_device *wdev = to_wmi_device(dev);
713 int ret;
714
715 ret = driver_set_override(dev, &wdev->driver_override, buf, count);
716 if (ret < 0)
717 return ret;
718
719 return count;
720}
721static DEVICE_ATTR_RW(driver_override);
722
723static struct attribute *wmi_attrs[] = {
724 &dev_attr_modalias.attr,
725 &dev_attr_guid.attr,
726 &dev_attr_instance_count.attr,
727 &dev_attr_expensive.attr,
728 &dev_attr_driver_override.attr,
729 NULL
730};
731ATTRIBUTE_GROUPS(wmi);
732
733static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
734 char *buf)
735{
736 struct wmi_block *wblock = dev_to_wblock(dev);
737
738 return sysfs_emit(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
739}
740static DEVICE_ATTR_RO(notify_id);
741
742static struct attribute *wmi_event_attrs[] = {
743 &dev_attr_notify_id.attr,
744 NULL
745};
746ATTRIBUTE_GROUPS(wmi_event);
747
748static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
749 char *buf)
750{
751 struct wmi_block *wblock = dev_to_wblock(dev);
752
753 return sysfs_emit(buf, "%c%c\n", wblock->gblock.object_id[0],
754 wblock->gblock.object_id[1]);
755}
756static DEVICE_ATTR_RO(object_id);
757
758static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
759 char *buf)
760{
761 struct wmi_device *wdev = to_wmi_device(dev);
762
763 return sysfs_emit(buf, "%d\n", (int)wdev->setable);
764}
765static DEVICE_ATTR_RO(setable);
766
767static struct attribute *wmi_data_attrs[] = {
768 &dev_attr_object_id.attr,
769 &dev_attr_setable.attr,
770 NULL
771};
772ATTRIBUTE_GROUPS(wmi_data);
773
774static struct attribute *wmi_method_attrs[] = {
775 &dev_attr_object_id.attr,
776 NULL
777};
778ATTRIBUTE_GROUPS(wmi_method);
779
780static int wmi_dev_uevent(const struct device *dev, struct kobj_uevent_env *env)
781{
782 const struct wmi_block *wblock = dev_to_wblock(dev);
783
784 if (add_uevent_var(env, "MODALIAS=wmi:%pUL", &wblock->gblock.guid))
785 return -ENOMEM;
786
787 if (add_uevent_var(env, "WMI_GUID=%pUL", &wblock->gblock.guid))
788 return -ENOMEM;
789
790 return 0;
791}
792
793static void wmi_dev_release(struct device *dev)
794{
795 struct wmi_block *wblock = dev_to_wblock(dev);
796
797 kfree(wblock->dev.driver_override);
798 kfree(wblock);
799}
800
801static int wmi_dev_match(struct device *dev, const struct device_driver *driver)
802{
803 const struct wmi_driver *wmi_driver = to_wmi_driver(driver);
804 struct wmi_block *wblock = dev_to_wblock(dev);
805 const struct wmi_device_id *id = wmi_driver->id_table;
806
807 /* When driver_override is set, only bind to the matching driver */
808 if (wblock->dev.driver_override)
809 return !strcmp(wblock->dev.driver_override, driver->name);
810
811 if (id == NULL)
812 return 0;
813
814 while (*id->guid_string) {
815 if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid))
816 return 1;
817
818 id++;
819 }
820
821 return 0;
822}
823
824static int wmi_dev_probe(struct device *dev)
825{
826 struct wmi_block *wblock = dev_to_wblock(dev);
827 struct wmi_driver *wdriver = to_wmi_driver(dev->driver);
828 int ret = 0;
829
830 /* Some older WMI drivers will break if instantiated multiple times,
831 * so they are blocked from probing WMI devices with a duplicated GUID.
832 *
833 * New WMI drivers should support being instantiated multiple times.
834 */
835 if (test_bit(WMI_GUID_DUPLICATED, &wblock->flags) && !wdriver->no_singleton) {
836 dev_warn(dev, "Legacy driver %s cannot be instantiated multiple times\n",
837 dev->driver->name);
838
839 return -ENODEV;
840 }
841
842 if (wdriver->notify) {
843 if (test_bit(WMI_NO_EVENT_DATA, &wblock->flags) && !wdriver->no_notify_data)
844 return -ENODEV;
845 }
846
847 if (ACPI_FAILURE(wmi_method_enable(wblock, true)))
848 dev_warn(dev, "failed to enable device -- probing anyway\n");
849
850 if (wdriver->probe) {
851 ret = wdriver->probe(to_wmi_device(dev),
852 find_guid_context(wblock, wdriver));
853 if (ret) {
854 if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
855 dev_warn(dev, "Failed to disable device\n");
856
857 return ret;
858 }
859 }
860
861 down_write(&wblock->notify_lock);
862 wblock->driver_ready = true;
863 up_write(&wblock->notify_lock);
864
865 return 0;
866}
867
868static void wmi_dev_remove(struct device *dev)
869{
870 struct wmi_block *wblock = dev_to_wblock(dev);
871 struct wmi_driver *wdriver = to_wmi_driver(dev->driver);
872
873 down_write(&wblock->notify_lock);
874 wblock->driver_ready = false;
875 up_write(&wblock->notify_lock);
876
877 if (wdriver->remove)
878 wdriver->remove(to_wmi_device(dev));
879
880 if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
881 dev_warn(dev, "failed to disable device\n");
882}
883
884static void wmi_dev_shutdown(struct device *dev)
885{
886 struct wmi_driver *wdriver;
887 struct wmi_block *wblock;
888
889 if (dev->driver) {
890 wdriver = to_wmi_driver(dev->driver);
891 wblock = dev_to_wblock(dev);
892
893 /*
894 * Some machines return bogus WMI event data when disabling
895 * the WMI event. Because of this we must prevent the associated
896 * WMI driver from receiving new WMI events before disabling it.
897 */
898 down_write(&wblock->notify_lock);
899 wblock->driver_ready = false;
900 up_write(&wblock->notify_lock);
901
902 if (wdriver->shutdown)
903 wdriver->shutdown(to_wmi_device(dev));
904
905 if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
906 dev_warn(dev, "Failed to disable device\n");
907 }
908}
909
910static struct class wmi_bus_class = {
911 .name = "wmi_bus",
912};
913
914static const struct bus_type wmi_bus_type = {
915 .name = "wmi",
916 .dev_groups = wmi_groups,
917 .match = wmi_dev_match,
918 .uevent = wmi_dev_uevent,
919 .probe = wmi_dev_probe,
920 .remove = wmi_dev_remove,
921 .shutdown = wmi_dev_shutdown,
922};
923
924static const struct device_type wmi_type_event = {
925 .name = "event",
926 .groups = wmi_event_groups,
927 .release = wmi_dev_release,
928};
929
930static const struct device_type wmi_type_method = {
931 .name = "method",
932 .groups = wmi_method_groups,
933 .release = wmi_dev_release,
934};
935
936static const struct device_type wmi_type_data = {
937 .name = "data",
938 .groups = wmi_data_groups,
939 .release = wmi_dev_release,
940};
941
942static int wmi_count_guids(struct device *dev, void *data)
943{
944 struct wmi_guid_count_context *context = data;
945 struct wmi_block *wblock = dev_to_wblock(dev);
946
947 if (guid_equal(&wblock->gblock.guid, context->guid))
948 context->count++;
949
950 return 0;
951}
952
953static int guid_count(const guid_t *guid)
954{
955 struct wmi_guid_count_context context = {
956 .guid = guid,
957 .count = 0,
958 };
959 int ret;
960
961 ret = bus_for_each_dev(&wmi_bus_type, NULL, &context, wmi_count_guids);
962 if (ret < 0)
963 return ret;
964
965 return context.count;
966}
967
968static int wmi_create_device(struct device *wmi_bus_dev,
969 struct wmi_block *wblock,
970 struct acpi_device *device)
971{
972 char method[WMI_ACPI_METHOD_NAME_SIZE];
973 struct acpi_device_info *info;
974 acpi_handle method_handle;
975 acpi_status status;
976 int count;
977
978 if (wblock->gblock.flags & ACPI_WMI_EVENT) {
979 wblock->dev.dev.type = &wmi_type_event;
980 goto out_init;
981 }
982
983 if (wblock->gblock.flags & ACPI_WMI_METHOD) {
984 get_acpi_method_name(wblock, 'M', method);
985 if (!acpi_has_method(device->handle, method)) {
986 dev_warn(wmi_bus_dev,
987 FW_BUG "%s method block execution control method not found\n",
988 method);
989
990 return -ENXIO;
991 }
992
993 wblock->dev.dev.type = &wmi_type_method;
994 goto out_init;
995 }
996
997 /*
998 * Data Block Query Control Method (WQxx by convention) is
999 * required per the WMI documentation. If it is not present,
1000 * we ignore this data block.
1001 */
1002 get_acpi_method_name(wblock, 'Q', method);
1003 status = acpi_get_handle(device->handle, method, &method_handle);
1004 if (ACPI_FAILURE(status)) {
1005 dev_warn(wmi_bus_dev,
1006 FW_BUG "%s data block query control method not found\n",
1007 method);
1008
1009 return -ENXIO;
1010 }
1011
1012 status = acpi_get_object_info(method_handle, &info);
1013 if (ACPI_FAILURE(status))
1014 return -EIO;
1015
1016 wblock->dev.dev.type = &wmi_type_data;
1017
1018 /*
1019 * The Microsoft documentation specifically states:
1020 *
1021 * Data blocks registered with only a single instance
1022 * can ignore the parameter.
1023 *
1024 * ACPICA will get mad at us if we call the method with the wrong number
1025 * of arguments, so check what our method expects. (On some Dell
1026 * laptops, WQxx may not be a method at all.)
1027 */
1028 if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1029 set_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags);
1030
1031 kfree(info);
1032
1033 get_acpi_method_name(wblock, 'S', method);
1034 if (acpi_has_method(device->handle, method))
1035 wblock->dev.setable = true;
1036
1037 out_init:
1038 init_rwsem(&wblock->notify_lock);
1039 wblock->driver_ready = false;
1040 wblock->dev.dev.bus = &wmi_bus_type;
1041 wblock->dev.dev.parent = wmi_bus_dev;
1042
1043 count = guid_count(&wblock->gblock.guid);
1044 if (count < 0)
1045 return count;
1046
1047 if (count) {
1048 dev_set_name(&wblock->dev.dev, "%pUL-%d", &wblock->gblock.guid, count);
1049 set_bit(WMI_GUID_DUPLICATED, &wblock->flags);
1050 } else {
1051 dev_set_name(&wblock->dev.dev, "%pUL", &wblock->gblock.guid);
1052 }
1053
1054 device_initialize(&wblock->dev.dev);
1055
1056 return 0;
1057}
1058
1059static int wmi_add_device(struct platform_device *pdev, struct wmi_device *wdev)
1060{
1061 struct device_link *link;
1062
1063 /*
1064 * Many aggregate WMI drivers do not use -EPROBE_DEFER when they
1065 * are unable to find a WMI device during probe, instead they require
1066 * all WMI devices associated with an platform device to become available
1067 * at once. This device link thus prevents WMI drivers from probing until
1068 * the associated platform device has finished probing (and has registered
1069 * all discovered WMI devices).
1070 */
1071
1072 link = device_link_add(&wdev->dev, &pdev->dev, DL_FLAG_AUTOREMOVE_SUPPLIER);
1073 if (!link)
1074 return -EINVAL;
1075
1076 return device_add(&wdev->dev);
1077}
1078
1079/*
1080 * Parse the _WDG method for the GUID data blocks
1081 */
1082static int parse_wdg(struct device *wmi_bus_dev, struct platform_device *pdev)
1083{
1084 struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
1085 struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1086 const struct guid_block *gblock;
1087 bool event_data_available;
1088 struct wmi_block *wblock;
1089 union acpi_object *obj;
1090 acpi_status status;
1091 u32 i, total;
1092 int retval;
1093
1094 status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1095 if (ACPI_FAILURE(status))
1096 return -ENXIO;
1097
1098 obj = out.pointer;
1099 if (!obj)
1100 return -ENXIO;
1101
1102 if (obj->type != ACPI_TYPE_BUFFER) {
1103 kfree(obj);
1104 return -ENXIO;
1105 }
1106
1107 event_data_available = acpi_has_method(device->handle, "_WED");
1108 gblock = (const struct guid_block *)obj->buffer.pointer;
1109 total = obj->buffer.length / sizeof(struct guid_block);
1110
1111 for (i = 0; i < total; i++) {
1112 if (!gblock[i].instance_count) {
1113 dev_info(wmi_bus_dev, FW_INFO "%pUL has zero instances\n", &gblock[i].guid);
1114 continue;
1115 }
1116
1117 wblock = kzalloc(sizeof(*wblock), GFP_KERNEL);
1118 if (!wblock)
1119 continue;
1120
1121 wblock->acpi_device = device;
1122 wblock->gblock = gblock[i];
1123 if (gblock[i].flags & ACPI_WMI_EVENT && !event_data_available)
1124 set_bit(WMI_NO_EVENT_DATA, &wblock->flags);
1125
1126 retval = wmi_create_device(wmi_bus_dev, wblock, device);
1127 if (retval) {
1128 kfree(wblock);
1129 continue;
1130 }
1131
1132 retval = wmi_add_device(pdev, &wblock->dev);
1133 if (retval) {
1134 dev_err(wmi_bus_dev, "failed to register %pUL\n",
1135 &wblock->gblock.guid);
1136
1137 put_device(&wblock->dev.dev);
1138 }
1139 }
1140
1141 kfree(obj);
1142
1143 return 0;
1144}
1145
1146static int wmi_get_notify_data(struct wmi_block *wblock, union acpi_object **obj)
1147{
1148 struct acpi_buffer data = { ACPI_ALLOCATE_BUFFER, NULL };
1149 union acpi_object param = {
1150 .integer = {
1151 .type = ACPI_TYPE_INTEGER,
1152 .value = wblock->gblock.notify_id,
1153 }
1154 };
1155 struct acpi_object_list input = {
1156 .count = 1,
1157 .pointer = ¶m,
1158 };
1159 acpi_status status;
1160
1161 status = acpi_evaluate_object(wblock->acpi_device->handle, "_WED", &input, &data);
1162 if (ACPI_FAILURE(status)) {
1163 dev_warn(&wblock->dev.dev, "Failed to get event data\n");
1164 return -EIO;
1165 }
1166
1167 *obj = data.pointer;
1168
1169 return 0;
1170}
1171
1172static void wmi_notify_driver(struct wmi_block *wblock, union acpi_object *obj)
1173{
1174 struct wmi_driver *driver = to_wmi_driver(wblock->dev.dev.driver);
1175
1176 if (!obj && !driver->no_notify_data) {
1177 dev_warn(&wblock->dev.dev, "Event contains no event data\n");
1178 return;
1179 }
1180
1181 if (driver->notify)
1182 driver->notify(&wblock->dev, obj);
1183}
1184
1185static int wmi_notify_device(struct device *dev, void *data)
1186{
1187 struct wmi_block *wblock = dev_to_wblock(dev);
1188 union acpi_object *obj = NULL;
1189 u32 *event = data;
1190 int ret;
1191
1192 if (!(wblock->gblock.flags & ACPI_WMI_EVENT && wblock->gblock.notify_id == *event))
1193 return 0;
1194
1195 /* The ACPI WMI specification says that _WED should be
1196 * evaluated every time an notification is received, even
1197 * if no consumers are present.
1198 *
1199 * Some firmware implementations actually depend on this
1200 * by using a queue for events which will fill up if the
1201 * WMI driver core stops evaluating _WED due to missing
1202 * WMI event consumers.
1203 */
1204 if (!test_bit(WMI_NO_EVENT_DATA, &wblock->flags)) {
1205 ret = wmi_get_notify_data(wblock, &obj);
1206 if (ret < 0)
1207 return -EIO;
1208 }
1209
1210 down_read(&wblock->notify_lock);
1211
1212 if (wblock->dev.dev.driver && wblock->driver_ready)
1213 wmi_notify_driver(wblock, obj);
1214
1215 if (wblock->handler)
1216 wblock->handler(obj, wblock->handler_data);
1217
1218 up_read(&wblock->notify_lock);
1219
1220 kfree(obj);
1221
1222 acpi_bus_generate_netlink_event("wmi", acpi_dev_name(wblock->acpi_device), *event, 0);
1223
1224 return -EBUSY;
1225}
1226
1227static void acpi_wmi_notify_handler(acpi_handle handle, u32 event, void *context)
1228{
1229 struct device *wmi_bus_dev = context;
1230
1231 device_for_each_child(wmi_bus_dev, &event, wmi_notify_device);
1232}
1233
1234static int wmi_remove_device(struct device *dev, void *data)
1235{
1236 device_unregister(dev);
1237
1238 return 0;
1239}
1240
1241static void acpi_wmi_remove(struct platform_device *device)
1242{
1243 struct device *wmi_bus_device = dev_get_drvdata(&device->dev);
1244
1245 device_for_each_child_reverse(wmi_bus_device, NULL, wmi_remove_device);
1246}
1247
1248static void acpi_wmi_remove_notify_handler(void *data)
1249{
1250 struct acpi_device *acpi_device = data;
1251
1252 acpi_remove_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY, acpi_wmi_notify_handler);
1253}
1254
1255static void acpi_wmi_remove_bus_device(void *data)
1256{
1257 struct device *wmi_bus_dev = data;
1258
1259 device_unregister(wmi_bus_dev);
1260}
1261
1262static int acpi_wmi_probe(struct platform_device *device)
1263{
1264 struct acpi_device *acpi_device;
1265 struct device *wmi_bus_dev;
1266 acpi_status status;
1267 int error;
1268
1269 acpi_device = ACPI_COMPANION(&device->dev);
1270 if (!acpi_device) {
1271 dev_err(&device->dev, "ACPI companion is missing\n");
1272 return -ENODEV;
1273 }
1274
1275 wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0), NULL, "wmi_bus-%s",
1276 dev_name(&device->dev));
1277 if (IS_ERR(wmi_bus_dev))
1278 return PTR_ERR(wmi_bus_dev);
1279
1280 error = devm_add_action_or_reset(&device->dev, acpi_wmi_remove_bus_device, wmi_bus_dev);
1281 if (error < 0)
1282 return error;
1283
1284 dev_set_drvdata(&device->dev, wmi_bus_dev);
1285
1286 status = acpi_install_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY,
1287 acpi_wmi_notify_handler, wmi_bus_dev);
1288 if (ACPI_FAILURE(status)) {
1289 dev_err(&device->dev, "Error installing notify handler\n");
1290 return -ENODEV;
1291 }
1292 error = devm_add_action_or_reset(&device->dev, acpi_wmi_remove_notify_handler,
1293 acpi_device);
1294 if (error < 0)
1295 return error;
1296
1297 error = parse_wdg(wmi_bus_dev, device);
1298 if (error) {
1299 dev_err(&device->dev, "Failed to parse _WDG method\n");
1300 return error;
1301 }
1302
1303 return 0;
1304}
1305
1306int __must_check __wmi_driver_register(struct wmi_driver *driver,
1307 struct module *owner)
1308{
1309 driver->driver.owner = owner;
1310 driver->driver.bus = &wmi_bus_type;
1311
1312 return driver_register(&driver->driver);
1313}
1314EXPORT_SYMBOL(__wmi_driver_register);
1315
1316/**
1317 * wmi_driver_unregister() - Unregister a WMI driver
1318 * @driver: WMI driver to unregister
1319 *
1320 * Unregisters a WMI driver from the WMI bus.
1321 */
1322void wmi_driver_unregister(struct wmi_driver *driver)
1323{
1324 driver_unregister(&driver->driver);
1325}
1326EXPORT_SYMBOL(wmi_driver_unregister);
1327
1328static struct platform_driver acpi_wmi_driver = {
1329 .driver = {
1330 .name = "acpi-wmi",
1331 .acpi_match_table = wmi_device_ids,
1332 },
1333 .probe = acpi_wmi_probe,
1334 .remove = acpi_wmi_remove,
1335};
1336
1337static int __init acpi_wmi_init(void)
1338{
1339 int error;
1340
1341 if (acpi_disabled)
1342 return -ENODEV;
1343
1344 error = class_register(&wmi_bus_class);
1345 if (error)
1346 return error;
1347
1348 error = bus_register(&wmi_bus_type);
1349 if (error)
1350 goto err_unreg_class;
1351
1352 error = platform_driver_register(&acpi_wmi_driver);
1353 if (error) {
1354 pr_err("Error loading mapper\n");
1355 goto err_unreg_bus;
1356 }
1357
1358 return 0;
1359
1360err_unreg_bus:
1361 bus_unregister(&wmi_bus_type);
1362
1363err_unreg_class:
1364 class_unregister(&wmi_bus_class);
1365
1366 return error;
1367}
1368
1369static void __exit acpi_wmi_exit(void)
1370{
1371 platform_driver_unregister(&acpi_wmi_driver);
1372 bus_unregister(&wmi_bus_type);
1373 class_unregister(&wmi_bus_class);
1374}
1375
1376subsys_initcall_sync(acpi_wmi_init);
1377module_exit(acpi_wmi_exit);