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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/list.h>
26#include <linux/miscdevice.h>
27#include <linux/module.h>
28#include <linux/platform_device.h>
29#include <linux/slab.h>
30#include <linux/sysfs.h>
31#include <linux/types.h>
32#include <linux/uaccess.h>
33#include <linux/uuid.h>
34#include <linux/wmi.h>
35#include <linux/fs.h>
36#include <uapi/linux/wmi.h>
37
38MODULE_AUTHOR("Carlos Corbacho");
39MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
40MODULE_LICENSE("GPL");
41
42static LIST_HEAD(wmi_block_list);
43
44struct guid_block {
45 guid_t guid;
46 union {
47 char object_id[2];
48 struct {
49 unsigned char notify_id;
50 unsigned char reserved;
51 };
52 };
53 u8 instance_count;
54 u8 flags;
55} __packed;
56static_assert(sizeof(typeof_member(struct guid_block, guid)) == 16);
57static_assert(sizeof(struct guid_block) == 20);
58static_assert(__alignof__(struct guid_block) == 1);
59
60enum { /* wmi_block flags */
61 WMI_READ_TAKES_NO_ARGS,
62 WMI_PROBED,
63};
64
65struct wmi_block {
66 struct wmi_device dev;
67 struct list_head list;
68 struct guid_block gblock;
69 struct miscdevice char_dev;
70 struct mutex char_mutex;
71 struct acpi_device *acpi_device;
72 wmi_notify_handler handler;
73 void *handler_data;
74 u64 req_buf_size;
75 unsigned long flags;
76};
77
78
79/*
80 * If the GUID data block is marked as expensive, we must enable and
81 * explicitily disable data collection.
82 */
83#define ACPI_WMI_EXPENSIVE BIT(0)
84#define ACPI_WMI_METHOD BIT(1) /* GUID is a method */
85#define ACPI_WMI_STRING BIT(2) /* GUID takes & returns a string */
86#define ACPI_WMI_EVENT BIT(3) /* GUID is an event */
87
88static bool debug_event;
89module_param(debug_event, bool, 0444);
90MODULE_PARM_DESC(debug_event,
91 "Log WMI Events [0/1]");
92
93static bool debug_dump_wdg;
94module_param(debug_dump_wdg, bool, 0444);
95MODULE_PARM_DESC(debug_dump_wdg,
96 "Dump available WMI interfaces [0/1]");
97
98static const struct acpi_device_id wmi_device_ids[] = {
99 {"PNP0C14", 0},
100 {"pnp0c14", 0},
101 { }
102};
103MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
104
105/* allow duplicate GUIDs as these device drivers use struct wmi_driver */
106static const char * const allow_duplicates[] = {
107 "05901221-D566-11D1-B2F0-00A0C9062910", /* wmi-bmof */
108 "8A42EA14-4F2A-FD45-6422-0087F7A7E608", /* dell-wmi-ddv */
109 NULL
110};
111
112/*
113 * GUID parsing functions
114 */
115
116static acpi_status find_guid(const char *guid_string, struct wmi_block **out)
117{
118 guid_t guid_input;
119 struct wmi_block *wblock;
120
121 if (!guid_string)
122 return AE_BAD_PARAMETER;
123
124 if (guid_parse(guid_string, &guid_input))
125 return AE_BAD_PARAMETER;
126
127 list_for_each_entry(wblock, &wmi_block_list, list) {
128 if (guid_equal(&wblock->gblock.guid, &guid_input)) {
129 if (out)
130 *out = wblock;
131
132 return AE_OK;
133 }
134 }
135
136 return AE_NOT_FOUND;
137}
138
139static const void *find_guid_context(struct wmi_block *wblock,
140 struct wmi_driver *wdriver)
141{
142 const struct wmi_device_id *id;
143
144 id = wdriver->id_table;
145 if (!id)
146 return NULL;
147
148 while (*id->guid_string) {
149 guid_t guid_input;
150
151 if (guid_parse(id->guid_string, &guid_input))
152 continue;
153 if (guid_equal(&wblock->gblock.guid, &guid_input))
154 return id->context;
155 id++;
156 }
157 return NULL;
158}
159
160static int get_subobj_info(acpi_handle handle, const char *pathname,
161 struct acpi_device_info **info)
162{
163 struct acpi_device_info *dummy_info, **info_ptr;
164 acpi_handle subobj_handle;
165 acpi_status status;
166
167 status = acpi_get_handle(handle, (char *)pathname, &subobj_handle);
168 if (status == AE_NOT_FOUND)
169 return -ENOENT;
170 else if (ACPI_FAILURE(status))
171 return -EIO;
172
173 info_ptr = info ? info : &dummy_info;
174 status = acpi_get_object_info(subobj_handle, info_ptr);
175 if (ACPI_FAILURE(status))
176 return -EIO;
177
178 if (!info)
179 kfree(dummy_info);
180
181 return 0;
182}
183
184static acpi_status wmi_method_enable(struct wmi_block *wblock, bool enable)
185{
186 struct guid_block *block;
187 char method[5];
188 acpi_status status;
189 acpi_handle handle;
190
191 block = &wblock->gblock;
192 handle = wblock->acpi_device->handle;
193
194 snprintf(method, 5, "WE%02X", block->notify_id);
195 status = acpi_execute_simple_method(handle, method, enable);
196 if (status == AE_NOT_FOUND)
197 return AE_OK;
198
199 return status;
200}
201
202#define WMI_ACPI_METHOD_NAME_SIZE 5
203
204static inline void get_acpi_method_name(const struct wmi_block *wblock,
205 const char method,
206 char buffer[static WMI_ACPI_METHOD_NAME_SIZE])
207{
208 static_assert(ARRAY_SIZE(wblock->gblock.object_id) == 2);
209 static_assert(WMI_ACPI_METHOD_NAME_SIZE >= 5);
210
211 buffer[0] = 'W';
212 buffer[1] = method;
213 buffer[2] = wblock->gblock.object_id[0];
214 buffer[3] = wblock->gblock.object_id[1];
215 buffer[4] = '\0';
216}
217
218static inline acpi_object_type get_param_acpi_type(const struct wmi_block *wblock)
219{
220 if (wblock->gblock.flags & ACPI_WMI_STRING)
221 return ACPI_TYPE_STRING;
222 else
223 return ACPI_TYPE_BUFFER;
224}
225
226static acpi_status get_event_data(const struct wmi_block *wblock, struct acpi_buffer *out)
227{
228 union acpi_object param = {
229 .integer = {
230 .type = ACPI_TYPE_INTEGER,
231 .value = wblock->gblock.notify_id,
232 }
233 };
234 struct acpi_object_list input = {
235 .count = 1,
236 .pointer = ¶m,
237 };
238
239 return acpi_evaluate_object(wblock->acpi_device->handle, "_WED", &input, out);
240}
241
242/*
243 * Exported WMI functions
244 */
245
246/**
247 * set_required_buffer_size - Sets the buffer size needed for performing IOCTL
248 * @wdev: A wmi bus device from a driver
249 * @length: Required buffer size
250 *
251 * Allocates memory needed for buffer, stores the buffer size in that memory
252 */
253int set_required_buffer_size(struct wmi_device *wdev, u64 length)
254{
255 struct wmi_block *wblock;
256
257 wblock = container_of(wdev, struct wmi_block, dev);
258 wblock->req_buf_size = length;
259
260 return 0;
261}
262EXPORT_SYMBOL_GPL(set_required_buffer_size);
263
264/**
265 * wmi_evaluate_method - Evaluate a WMI method
266 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
267 * @instance: Instance index
268 * @method_id: Method ID to call
269 * @in: Buffer containing input for the method call
270 * @out: Empty buffer to return the method results
271 *
272 * Call an ACPI-WMI method
273 */
274acpi_status wmi_evaluate_method(const char *guid_string, u8 instance, u32 method_id,
275 const struct acpi_buffer *in, struct acpi_buffer *out)
276{
277 struct wmi_block *wblock = NULL;
278 acpi_status status;
279
280 status = find_guid(guid_string, &wblock);
281 if (ACPI_FAILURE(status))
282 return status;
283
284 return wmidev_evaluate_method(&wblock->dev, instance, method_id,
285 in, out);
286}
287EXPORT_SYMBOL_GPL(wmi_evaluate_method);
288
289/**
290 * wmidev_evaluate_method - Evaluate a WMI method
291 * @wdev: A wmi bus device from a driver
292 * @instance: Instance index
293 * @method_id: Method ID to call
294 * @in: Buffer containing input for the method call
295 * @out: Empty buffer to return the method results
296 *
297 * Call an ACPI-WMI method
298 */
299acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance, u32 method_id,
300 const struct acpi_buffer *in, struct acpi_buffer *out)
301{
302 struct guid_block *block;
303 struct wmi_block *wblock;
304 acpi_handle handle;
305 struct acpi_object_list input;
306 union acpi_object params[3];
307 char method[WMI_ACPI_METHOD_NAME_SIZE];
308
309 wblock = container_of(wdev, struct wmi_block, dev);
310 block = &wblock->gblock;
311 handle = wblock->acpi_device->handle;
312
313 if (!(block->flags & ACPI_WMI_METHOD))
314 return AE_BAD_DATA;
315
316 if (block->instance_count <= instance)
317 return AE_BAD_PARAMETER;
318
319 input.count = 2;
320 input.pointer = params;
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
326 if (in) {
327 input.count = 3;
328
329 params[2].type = get_param_acpi_type(wblock);
330 params[2].buffer.length = in->length;
331 params[2].buffer.pointer = in->pointer;
332 }
333
334 get_acpi_method_name(wblock, 'M', method);
335
336 return acpi_evaluate_object(handle, method, &input, out);
337}
338EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
339
340static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
341 struct acpi_buffer *out)
342{
343 struct guid_block *block;
344 acpi_handle handle;
345 acpi_status status, wc_status = AE_ERROR;
346 struct acpi_object_list input;
347 union acpi_object wq_params[1];
348 char wc_method[WMI_ACPI_METHOD_NAME_SIZE];
349 char method[WMI_ACPI_METHOD_NAME_SIZE];
350
351 if (!out)
352 return AE_BAD_PARAMETER;
353
354 block = &wblock->gblock;
355 handle = wblock->acpi_device->handle;
356
357 if (block->instance_count <= instance)
358 return AE_BAD_PARAMETER;
359
360 /* Check GUID is a data block */
361 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
362 return AE_ERROR;
363
364 input.count = 1;
365 input.pointer = wq_params;
366 wq_params[0].type = ACPI_TYPE_INTEGER;
367 wq_params[0].integer.value = instance;
368
369 if (instance == 0 && test_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags))
370 input.count = 0;
371
372 /*
373 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
374 * enable collection.
375 */
376 if (block->flags & ACPI_WMI_EXPENSIVE) {
377 get_acpi_method_name(wblock, 'C', wc_method);
378
379 /*
380 * Some GUIDs break the specification by declaring themselves
381 * expensive, but have no corresponding WCxx method. So we
382 * should not fail if this happens.
383 */
384 wc_status = acpi_execute_simple_method(handle, wc_method, 1);
385 }
386
387 get_acpi_method_name(wblock, 'Q', method);
388 status = acpi_evaluate_object(handle, method, &input, out);
389
390 /*
391 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
392 * the WQxx method failed - we should disable collection anyway.
393 */
394 if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
395 /*
396 * Ignore whether this WCxx call succeeds or not since
397 * the previously executed WQxx method call might have
398 * succeeded, and returning the failing status code
399 * of this call would throw away the result of the WQxx
400 * call, potentially leaking memory.
401 */
402 acpi_execute_simple_method(handle, wc_method, 0);
403 }
404
405 return status;
406}
407
408/**
409 * wmi_query_block - Return contents of a WMI block (deprecated)
410 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
411 * @instance: Instance index
412 * @out: Empty buffer to return the contents of the data block to
413 *
414 * Return the contents of an ACPI-WMI data block to a buffer
415 */
416acpi_status wmi_query_block(const char *guid_string, u8 instance,
417 struct acpi_buffer *out)
418{
419 struct wmi_block *wblock;
420 acpi_status status;
421
422 status = find_guid(guid_string, &wblock);
423 if (ACPI_FAILURE(status))
424 return status;
425
426 return __query_block(wblock, instance, out);
427}
428EXPORT_SYMBOL_GPL(wmi_query_block);
429
430union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
431{
432 struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
433 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
434
435 if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
436 return NULL;
437
438 return out.pointer;
439}
440EXPORT_SYMBOL_GPL(wmidev_block_query);
441
442/**
443 * wmi_set_block - Write to a WMI block
444 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
445 * @instance: Instance index
446 * @in: Buffer containing new values for the data block
447 *
448 * Write the contents of the input buffer to an ACPI-WMI data block
449 */
450acpi_status wmi_set_block(const char *guid_string, u8 instance,
451 const struct acpi_buffer *in)
452{
453 struct wmi_block *wblock = NULL;
454 struct guid_block *block;
455 acpi_handle handle;
456 struct acpi_object_list input;
457 union acpi_object params[2];
458 char method[WMI_ACPI_METHOD_NAME_SIZE];
459 acpi_status status;
460
461 if (!in)
462 return AE_BAD_DATA;
463
464 status = find_guid(guid_string, &wblock);
465 if (ACPI_FAILURE(status))
466 return status;
467
468 block = &wblock->gblock;
469 handle = wblock->acpi_device->handle;
470
471 if (block->instance_count <= instance)
472 return AE_BAD_PARAMETER;
473
474 /* Check GUID is a data block */
475 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
476 return AE_ERROR;
477
478 input.count = 2;
479 input.pointer = params;
480 params[0].type = ACPI_TYPE_INTEGER;
481 params[0].integer.value = instance;
482 params[1].type = get_param_acpi_type(wblock);
483 params[1].buffer.length = in->length;
484 params[1].buffer.pointer = in->pointer;
485
486 get_acpi_method_name(wblock, 'S', method);
487
488 return acpi_evaluate_object(handle, method, &input, NULL);
489}
490EXPORT_SYMBOL_GPL(wmi_set_block);
491
492static void wmi_dump_wdg(const struct guid_block *g)
493{
494 pr_info("%pUL:\n", &g->guid);
495 if (g->flags & ACPI_WMI_EVENT)
496 pr_info("\tnotify_id: 0x%02X\n", g->notify_id);
497 else
498 pr_info("\tobject_id: %2pE\n", g->object_id);
499 pr_info("\tinstance_count: %d\n", g->instance_count);
500 pr_info("\tflags: %#x", g->flags);
501 if (g->flags) {
502 if (g->flags & ACPI_WMI_EXPENSIVE)
503 pr_cont(" ACPI_WMI_EXPENSIVE");
504 if (g->flags & ACPI_WMI_METHOD)
505 pr_cont(" ACPI_WMI_METHOD");
506 if (g->flags & ACPI_WMI_STRING)
507 pr_cont(" ACPI_WMI_STRING");
508 if (g->flags & ACPI_WMI_EVENT)
509 pr_cont(" ACPI_WMI_EVENT");
510 }
511 pr_cont("\n");
512
513}
514
515static void wmi_notify_debug(u32 value, void *context)
516{
517 struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
518 union acpi_object *obj;
519 acpi_status status;
520
521 status = wmi_get_event_data(value, &response);
522 if (status != AE_OK) {
523 pr_info("bad event status 0x%x\n", status);
524 return;
525 }
526
527 obj = response.pointer;
528 if (!obj)
529 return;
530
531 pr_info("DEBUG: event 0x%02X ", value);
532 switch (obj->type) {
533 case ACPI_TYPE_BUFFER:
534 pr_cont("BUFFER_TYPE - length %u\n", obj->buffer.length);
535 break;
536 case ACPI_TYPE_STRING:
537 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
538 break;
539 case ACPI_TYPE_INTEGER:
540 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
541 break;
542 case ACPI_TYPE_PACKAGE:
543 pr_cont("PACKAGE_TYPE - %u elements\n", obj->package.count);
544 break;
545 default:
546 pr_cont("object type 0x%X\n", obj->type);
547 }
548 kfree(obj);
549}
550
551/**
552 * wmi_install_notify_handler - Register handler for WMI events
553 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
554 * @handler: Function to handle notifications
555 * @data: Data to be returned to handler when event is fired
556 *
557 * Register a handler for events sent to the ACPI-WMI mapper device.
558 */
559acpi_status wmi_install_notify_handler(const char *guid,
560 wmi_notify_handler handler,
561 void *data)
562{
563 struct wmi_block *block;
564 acpi_status status = AE_NOT_EXIST;
565 guid_t guid_input;
566
567 if (!guid || !handler)
568 return AE_BAD_PARAMETER;
569
570 if (guid_parse(guid, &guid_input))
571 return AE_BAD_PARAMETER;
572
573 list_for_each_entry(block, &wmi_block_list, list) {
574 acpi_status wmi_status;
575
576 if (guid_equal(&block->gblock.guid, &guid_input)) {
577 if (block->handler &&
578 block->handler != wmi_notify_debug)
579 return AE_ALREADY_ACQUIRED;
580
581 block->handler = handler;
582 block->handler_data = data;
583
584 wmi_status = wmi_method_enable(block, true);
585 if ((wmi_status != AE_OK) ||
586 ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
587 status = wmi_status;
588 }
589 }
590
591 return status;
592}
593EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
594
595/**
596 * wmi_remove_notify_handler - Unregister handler for WMI events
597 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
598 *
599 * Unregister handler for events sent to the ACPI-WMI mapper device.
600 */
601acpi_status wmi_remove_notify_handler(const char *guid)
602{
603 struct wmi_block *block;
604 acpi_status status = AE_NOT_EXIST;
605 guid_t guid_input;
606
607 if (!guid)
608 return AE_BAD_PARAMETER;
609
610 if (guid_parse(guid, &guid_input))
611 return AE_BAD_PARAMETER;
612
613 list_for_each_entry(block, &wmi_block_list, list) {
614 acpi_status wmi_status;
615
616 if (guid_equal(&block->gblock.guid, &guid_input)) {
617 if (!block->handler ||
618 block->handler == wmi_notify_debug)
619 return AE_NULL_ENTRY;
620
621 if (debug_event) {
622 block->handler = wmi_notify_debug;
623 status = AE_OK;
624 } else {
625 wmi_status = wmi_method_enable(block, false);
626 block->handler = NULL;
627 block->handler_data = NULL;
628 if ((wmi_status != AE_OK) ||
629 ((wmi_status == AE_OK) &&
630 (status == AE_NOT_EXIST)))
631 status = wmi_status;
632 }
633 }
634 }
635
636 return status;
637}
638EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
639
640/**
641 * wmi_get_event_data - Get WMI data associated with an event
642 *
643 * @event: Event to find
644 * @out: Buffer to hold event data. out->pointer should be freed with kfree()
645 *
646 * Returns extra data associated with an event in WMI.
647 */
648acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
649{
650 struct wmi_block *wblock;
651
652 list_for_each_entry(wblock, &wmi_block_list, list) {
653 struct guid_block *gblock = &wblock->gblock;
654
655 if ((gblock->flags & ACPI_WMI_EVENT) && gblock->notify_id == event)
656 return get_event_data(wblock, out);
657 }
658
659 return AE_NOT_FOUND;
660}
661EXPORT_SYMBOL_GPL(wmi_get_event_data);
662
663/**
664 * wmi_has_guid - Check if a GUID is available
665 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
666 *
667 * Check if a given GUID is defined by _WDG
668 */
669bool wmi_has_guid(const char *guid_string)
670{
671 return ACPI_SUCCESS(find_guid(guid_string, NULL));
672}
673EXPORT_SYMBOL_GPL(wmi_has_guid);
674
675/**
676 * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID
677 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
678 *
679 * Find the _UID of ACPI device associated with this WMI GUID.
680 *
681 * Return: The ACPI _UID field value or NULL if the WMI GUID was not found
682 */
683char *wmi_get_acpi_device_uid(const char *guid_string)
684{
685 struct wmi_block *wblock = NULL;
686 acpi_status status;
687
688 status = find_guid(guid_string, &wblock);
689 if (ACPI_FAILURE(status))
690 return NULL;
691
692 return acpi_device_uid(wblock->acpi_device);
693}
694EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
695
696static struct wmi_block *dev_to_wblock(struct device *dev)
697{
698 return container_of(dev, struct wmi_block, dev.dev);
699}
700
701static struct wmi_device *dev_to_wdev(struct device *dev)
702{
703 return container_of(dev, struct wmi_device, dev);
704}
705
706static inline struct wmi_driver *drv_to_wdrv(struct device_driver *drv)
707{
708 return container_of(drv, struct wmi_driver, driver);
709}
710
711/*
712 * sysfs interface
713 */
714static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
715 char *buf)
716{
717 struct wmi_block *wblock = dev_to_wblock(dev);
718
719 return sysfs_emit(buf, "wmi:%pUL\n", &wblock->gblock.guid);
720}
721static DEVICE_ATTR_RO(modalias);
722
723static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
724 char *buf)
725{
726 struct wmi_block *wblock = dev_to_wblock(dev);
727
728 return sysfs_emit(buf, "%pUL\n", &wblock->gblock.guid);
729}
730static DEVICE_ATTR_RO(guid);
731
732static ssize_t instance_count_show(struct device *dev,
733 struct device_attribute *attr, char *buf)
734{
735 struct wmi_block *wblock = dev_to_wblock(dev);
736
737 return sysfs_emit(buf, "%d\n", (int)wblock->gblock.instance_count);
738}
739static DEVICE_ATTR_RO(instance_count);
740
741static ssize_t expensive_show(struct device *dev,
742 struct device_attribute *attr, char *buf)
743{
744 struct wmi_block *wblock = dev_to_wblock(dev);
745
746 return sysfs_emit(buf, "%d\n",
747 (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
748}
749static DEVICE_ATTR_RO(expensive);
750
751static struct attribute *wmi_attrs[] = {
752 &dev_attr_modalias.attr,
753 &dev_attr_guid.attr,
754 &dev_attr_instance_count.attr,
755 &dev_attr_expensive.attr,
756 NULL
757};
758ATTRIBUTE_GROUPS(wmi);
759
760static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
761 char *buf)
762{
763 struct wmi_block *wblock = dev_to_wblock(dev);
764
765 return sysfs_emit(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
766}
767static DEVICE_ATTR_RO(notify_id);
768
769static struct attribute *wmi_event_attrs[] = {
770 &dev_attr_notify_id.attr,
771 NULL
772};
773ATTRIBUTE_GROUPS(wmi_event);
774
775static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
776 char *buf)
777{
778 struct wmi_block *wblock = dev_to_wblock(dev);
779
780 return sysfs_emit(buf, "%c%c\n", wblock->gblock.object_id[0],
781 wblock->gblock.object_id[1]);
782}
783static DEVICE_ATTR_RO(object_id);
784
785static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
786 char *buf)
787{
788 struct wmi_device *wdev = dev_to_wdev(dev);
789
790 return sysfs_emit(buf, "%d\n", (int)wdev->setable);
791}
792static DEVICE_ATTR_RO(setable);
793
794static struct attribute *wmi_data_attrs[] = {
795 &dev_attr_object_id.attr,
796 &dev_attr_setable.attr,
797 NULL
798};
799ATTRIBUTE_GROUPS(wmi_data);
800
801static struct attribute *wmi_method_attrs[] = {
802 &dev_attr_object_id.attr,
803 NULL
804};
805ATTRIBUTE_GROUPS(wmi_method);
806
807static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
808{
809 struct wmi_block *wblock = dev_to_wblock(dev);
810
811 if (add_uevent_var(env, "MODALIAS=wmi:%pUL", &wblock->gblock.guid))
812 return -ENOMEM;
813
814 if (add_uevent_var(env, "WMI_GUID=%pUL", &wblock->gblock.guid))
815 return -ENOMEM;
816
817 return 0;
818}
819
820static void wmi_dev_release(struct device *dev)
821{
822 struct wmi_block *wblock = dev_to_wblock(dev);
823
824 kfree(wblock);
825}
826
827static int wmi_dev_match(struct device *dev, struct device_driver *driver)
828{
829 struct wmi_driver *wmi_driver = drv_to_wdrv(driver);
830 struct wmi_block *wblock = dev_to_wblock(dev);
831 const struct wmi_device_id *id = wmi_driver->id_table;
832
833 if (id == NULL)
834 return 0;
835
836 while (*id->guid_string) {
837 guid_t driver_guid;
838
839 if (WARN_ON(guid_parse(id->guid_string, &driver_guid)))
840 continue;
841 if (guid_equal(&driver_guid, &wblock->gblock.guid))
842 return 1;
843
844 id++;
845 }
846
847 return 0;
848}
849static int wmi_char_open(struct inode *inode, struct file *filp)
850{
851 const char *driver_name = filp->f_path.dentry->d_iname;
852 struct wmi_block *wblock;
853 struct wmi_block *next;
854
855 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
856 if (!wblock->dev.dev.driver)
857 continue;
858 if (strcmp(driver_name, wblock->dev.dev.driver->name) == 0) {
859 filp->private_data = wblock;
860 break;
861 }
862 }
863
864 if (!filp->private_data)
865 return -ENODEV;
866
867 return nonseekable_open(inode, filp);
868}
869
870static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
871 size_t length, loff_t *offset)
872{
873 struct wmi_block *wblock = filp->private_data;
874
875 return simple_read_from_buffer(buffer, length, offset,
876 &wblock->req_buf_size,
877 sizeof(wblock->req_buf_size));
878}
879
880static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
881{
882 struct wmi_ioctl_buffer __user *input =
883 (struct wmi_ioctl_buffer __user *) arg;
884 struct wmi_block *wblock = filp->private_data;
885 struct wmi_ioctl_buffer *buf;
886 struct wmi_driver *wdriver;
887 int ret;
888
889 if (_IOC_TYPE(cmd) != WMI_IOC)
890 return -ENOTTY;
891
892 /* make sure we're not calling a higher instance than exists*/
893 if (_IOC_NR(cmd) >= wblock->gblock.instance_count)
894 return -EINVAL;
895
896 mutex_lock(&wblock->char_mutex);
897 buf = wblock->handler_data;
898 if (get_user(buf->length, &input->length)) {
899 dev_dbg(&wblock->dev.dev, "Read length from user failed\n");
900 ret = -EFAULT;
901 goto out_ioctl;
902 }
903 /* if it's too small, abort */
904 if (buf->length < wblock->req_buf_size) {
905 dev_err(&wblock->dev.dev,
906 "Buffer %lld too small, need at least %lld\n",
907 buf->length, wblock->req_buf_size);
908 ret = -EINVAL;
909 goto out_ioctl;
910 }
911 /* if it's too big, warn, driver will only use what is needed */
912 if (buf->length > wblock->req_buf_size)
913 dev_warn(&wblock->dev.dev,
914 "Buffer %lld is bigger than required %lld\n",
915 buf->length, wblock->req_buf_size);
916
917 /* copy the structure from userspace */
918 if (copy_from_user(buf, input, wblock->req_buf_size)) {
919 dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n",
920 wblock->req_buf_size);
921 ret = -EFAULT;
922 goto out_ioctl;
923 }
924
925 /* let the driver do any filtering and do the call */
926 wdriver = drv_to_wdrv(wblock->dev.dev.driver);
927 if (!try_module_get(wdriver->driver.owner)) {
928 ret = -EBUSY;
929 goto out_ioctl;
930 }
931 ret = wdriver->filter_callback(&wblock->dev, cmd, buf);
932 module_put(wdriver->driver.owner);
933 if (ret)
934 goto out_ioctl;
935
936 /* return the result (only up to our internal buffer size) */
937 if (copy_to_user(input, buf, wblock->req_buf_size)) {
938 dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n",
939 wblock->req_buf_size);
940 ret = -EFAULT;
941 }
942
943out_ioctl:
944 mutex_unlock(&wblock->char_mutex);
945 return ret;
946}
947
948static const struct file_operations wmi_fops = {
949 .owner = THIS_MODULE,
950 .read = wmi_char_read,
951 .open = wmi_char_open,
952 .unlocked_ioctl = wmi_ioctl,
953 .compat_ioctl = compat_ptr_ioctl,
954};
955
956static int wmi_dev_probe(struct device *dev)
957{
958 struct wmi_block *wblock = dev_to_wblock(dev);
959 struct wmi_driver *wdriver = drv_to_wdrv(dev->driver);
960 int ret = 0;
961 char *buf;
962
963 if (ACPI_FAILURE(wmi_method_enable(wblock, true)))
964 dev_warn(dev, "failed to enable device -- probing anyway\n");
965
966 if (wdriver->probe) {
967 ret = wdriver->probe(dev_to_wdev(dev),
968 find_guid_context(wblock, wdriver));
969 if (ret != 0)
970 goto probe_failure;
971 }
972
973 /* driver wants a character device made */
974 if (wdriver->filter_callback) {
975 /* check that required buffer size declared by driver or MOF */
976 if (!wblock->req_buf_size) {
977 dev_err(&wblock->dev.dev,
978 "Required buffer size not set\n");
979 ret = -EINVAL;
980 goto probe_failure;
981 }
982
983 wblock->handler_data = kmalloc(wblock->req_buf_size,
984 GFP_KERNEL);
985 if (!wblock->handler_data) {
986 ret = -ENOMEM;
987 goto probe_failure;
988 }
989
990 buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name);
991 if (!buf) {
992 ret = -ENOMEM;
993 goto probe_string_failure;
994 }
995 wblock->char_dev.minor = MISC_DYNAMIC_MINOR;
996 wblock->char_dev.name = buf;
997 wblock->char_dev.fops = &wmi_fops;
998 wblock->char_dev.mode = 0444;
999 ret = misc_register(&wblock->char_dev);
1000 if (ret) {
1001 dev_warn(dev, "failed to register char dev: %d\n", ret);
1002 ret = -ENOMEM;
1003 goto probe_misc_failure;
1004 }
1005 }
1006
1007 set_bit(WMI_PROBED, &wblock->flags);
1008 return 0;
1009
1010probe_misc_failure:
1011 kfree(buf);
1012probe_string_failure:
1013 kfree(wblock->handler_data);
1014probe_failure:
1015 if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
1016 dev_warn(dev, "failed to disable device\n");
1017 return ret;
1018}
1019
1020static void wmi_dev_remove(struct device *dev)
1021{
1022 struct wmi_block *wblock = dev_to_wblock(dev);
1023 struct wmi_driver *wdriver = drv_to_wdrv(dev->driver);
1024
1025 clear_bit(WMI_PROBED, &wblock->flags);
1026
1027 if (wdriver->filter_callback) {
1028 misc_deregister(&wblock->char_dev);
1029 kfree(wblock->char_dev.name);
1030 kfree(wblock->handler_data);
1031 }
1032
1033 if (wdriver->remove)
1034 wdriver->remove(dev_to_wdev(dev));
1035
1036 if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
1037 dev_warn(dev, "failed to disable device\n");
1038}
1039
1040static struct class wmi_bus_class = {
1041 .name = "wmi_bus",
1042};
1043
1044static struct bus_type wmi_bus_type = {
1045 .name = "wmi",
1046 .dev_groups = wmi_groups,
1047 .match = wmi_dev_match,
1048 .uevent = wmi_dev_uevent,
1049 .probe = wmi_dev_probe,
1050 .remove = wmi_dev_remove,
1051};
1052
1053static const struct device_type wmi_type_event = {
1054 .name = "event",
1055 .groups = wmi_event_groups,
1056 .release = wmi_dev_release,
1057};
1058
1059static const struct device_type wmi_type_method = {
1060 .name = "method",
1061 .groups = wmi_method_groups,
1062 .release = wmi_dev_release,
1063};
1064
1065static const struct device_type wmi_type_data = {
1066 .name = "data",
1067 .groups = wmi_data_groups,
1068 .release = wmi_dev_release,
1069};
1070
1071/*
1072 * _WDG is a static list that is only parsed at startup,
1073 * so it's safe to count entries without extra protection.
1074 */
1075static int guid_count(const guid_t *guid)
1076{
1077 struct wmi_block *wblock;
1078 int count = 0;
1079
1080 list_for_each_entry(wblock, &wmi_block_list, list) {
1081 if (guid_equal(&wblock->gblock.guid, guid))
1082 count++;
1083 }
1084
1085 return count;
1086}
1087
1088static int wmi_create_device(struct device *wmi_bus_dev,
1089 struct wmi_block *wblock,
1090 struct acpi_device *device)
1091{
1092 struct acpi_device_info *info;
1093 char method[WMI_ACPI_METHOD_NAME_SIZE];
1094 int result;
1095 uint count;
1096
1097 if (wblock->gblock.flags & ACPI_WMI_EVENT) {
1098 wblock->dev.dev.type = &wmi_type_event;
1099 goto out_init;
1100 }
1101
1102 if (wblock->gblock.flags & ACPI_WMI_METHOD) {
1103 wblock->dev.dev.type = &wmi_type_method;
1104 mutex_init(&wblock->char_mutex);
1105 goto out_init;
1106 }
1107
1108 /*
1109 * Data Block Query Control Method (WQxx by convention) is
1110 * required per the WMI documentation. If it is not present,
1111 * we ignore this data block.
1112 */
1113 get_acpi_method_name(wblock, 'Q', method);
1114 result = get_subobj_info(device->handle, method, &info);
1115
1116 if (result) {
1117 dev_warn(wmi_bus_dev,
1118 "%s data block query control method not found\n",
1119 method);
1120 return result;
1121 }
1122
1123 wblock->dev.dev.type = &wmi_type_data;
1124
1125 /*
1126 * The Microsoft documentation specifically states:
1127 *
1128 * Data blocks registered with only a single instance
1129 * can ignore the parameter.
1130 *
1131 * ACPICA will get mad at us if we call the method with the wrong number
1132 * of arguments, so check what our method expects. (On some Dell
1133 * laptops, WQxx may not be a method at all.)
1134 */
1135 if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1136 set_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags);
1137
1138 kfree(info);
1139
1140 get_acpi_method_name(wblock, 'S', method);
1141 result = get_subobj_info(device->handle, method, NULL);
1142
1143 if (result == 0)
1144 wblock->dev.setable = true;
1145
1146 out_init:
1147 wblock->dev.dev.bus = &wmi_bus_type;
1148 wblock->dev.dev.parent = wmi_bus_dev;
1149
1150 count = guid_count(&wblock->gblock.guid);
1151 if (count)
1152 dev_set_name(&wblock->dev.dev, "%pUL-%d", &wblock->gblock.guid, count);
1153 else
1154 dev_set_name(&wblock->dev.dev, "%pUL", &wblock->gblock.guid);
1155
1156 device_initialize(&wblock->dev.dev);
1157
1158 return 0;
1159}
1160
1161static void wmi_free_devices(struct acpi_device *device)
1162{
1163 struct wmi_block *wblock, *next;
1164
1165 /* Delete devices for all the GUIDs */
1166 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1167 if (wblock->acpi_device == device) {
1168 list_del(&wblock->list);
1169 device_unregister(&wblock->dev.dev);
1170 }
1171 }
1172}
1173
1174static bool guid_already_parsed_for_legacy(struct acpi_device *device, const guid_t *guid)
1175{
1176 struct wmi_block *wblock;
1177
1178 list_for_each_entry(wblock, &wmi_block_list, list) {
1179 /* skip warning and register if we know the driver will use struct wmi_driver */
1180 for (int i = 0; allow_duplicates[i] != NULL; i++) {
1181 guid_t tmp;
1182
1183 if (guid_parse(allow_duplicates[i], &tmp))
1184 continue;
1185 if (guid_equal(&tmp, guid))
1186 return false;
1187 }
1188 if (guid_equal(&wblock->gblock.guid, guid)) {
1189 /*
1190 * Because we historically didn't track the relationship
1191 * between GUIDs and ACPI nodes, we don't know whether
1192 * we need to suppress GUIDs that are unique on a
1193 * given node but duplicated across nodes.
1194 */
1195 dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
1196 guid, dev_name(&wblock->acpi_device->dev));
1197 return true;
1198 }
1199 }
1200
1201 return false;
1202}
1203
1204/*
1205 * Parse the _WDG method for the GUID data blocks
1206 */
1207static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
1208{
1209 struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1210 const struct guid_block *gblock;
1211 struct wmi_block *wblock, *next;
1212 union acpi_object *obj;
1213 acpi_status status;
1214 int retval = 0;
1215 u32 i, total;
1216
1217 status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1218 if (ACPI_FAILURE(status))
1219 return -ENXIO;
1220
1221 obj = out.pointer;
1222 if (!obj)
1223 return -ENXIO;
1224
1225 if (obj->type != ACPI_TYPE_BUFFER) {
1226 retval = -ENXIO;
1227 goto out_free_pointer;
1228 }
1229
1230 gblock = (const struct guid_block *)obj->buffer.pointer;
1231 total = obj->buffer.length / sizeof(struct guid_block);
1232
1233 for (i = 0; i < total; i++) {
1234 if (debug_dump_wdg)
1235 wmi_dump_wdg(&gblock[i]);
1236
1237 if (guid_already_parsed_for_legacy(device, &gblock[i].guid))
1238 continue;
1239
1240 wblock = kzalloc(sizeof(*wblock), GFP_KERNEL);
1241 if (!wblock) {
1242 retval = -ENOMEM;
1243 break;
1244 }
1245
1246 wblock->acpi_device = device;
1247 wblock->gblock = gblock[i];
1248
1249 retval = wmi_create_device(wmi_bus_dev, wblock, device);
1250 if (retval) {
1251 kfree(wblock);
1252 continue;
1253 }
1254
1255 list_add_tail(&wblock->list, &wmi_block_list);
1256
1257 if (debug_event) {
1258 wblock->handler = wmi_notify_debug;
1259 wmi_method_enable(wblock, true);
1260 }
1261 }
1262
1263 /*
1264 * Now that all of the devices are created, add them to the
1265 * device tree and probe subdrivers.
1266 */
1267 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1268 if (wblock->acpi_device != device)
1269 continue;
1270
1271 retval = device_add(&wblock->dev.dev);
1272 if (retval) {
1273 dev_err(wmi_bus_dev, "failed to register %pUL\n",
1274 &wblock->gblock.guid);
1275 if (debug_event)
1276 wmi_method_enable(wblock, false);
1277 list_del(&wblock->list);
1278 put_device(&wblock->dev.dev);
1279 }
1280 }
1281
1282out_free_pointer:
1283 kfree(out.pointer);
1284 return retval;
1285}
1286
1287/*
1288 * WMI can have EmbeddedControl access regions. In which case, we just want to
1289 * hand these off to the EC driver.
1290 */
1291static acpi_status
1292acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1293 u32 bits, u64 *value,
1294 void *handler_context, void *region_context)
1295{
1296 int result = 0, i = 0;
1297 u8 temp = 0;
1298
1299 if ((address > 0xFF) || !value)
1300 return AE_BAD_PARAMETER;
1301
1302 if (function != ACPI_READ && function != ACPI_WRITE)
1303 return AE_BAD_PARAMETER;
1304
1305 if (bits != 8)
1306 return AE_BAD_PARAMETER;
1307
1308 if (function == ACPI_READ) {
1309 result = ec_read(address, &temp);
1310 (*value) |= ((u64)temp) << i;
1311 } else {
1312 temp = 0xff & ((*value) >> i);
1313 result = ec_write(address, temp);
1314 }
1315
1316 switch (result) {
1317 case -EINVAL:
1318 return AE_BAD_PARAMETER;
1319 case -ENODEV:
1320 return AE_NOT_FOUND;
1321 case -ETIME:
1322 return AE_TIME;
1323 default:
1324 return AE_OK;
1325 }
1326}
1327
1328static void acpi_wmi_notify_handler(acpi_handle handle, u32 event,
1329 void *context)
1330{
1331 struct wmi_block *wblock = NULL, *iter;
1332
1333 list_for_each_entry(iter, &wmi_block_list, list) {
1334 struct guid_block *block = &iter->gblock;
1335
1336 if (iter->acpi_device->handle == handle &&
1337 (block->flags & ACPI_WMI_EVENT) &&
1338 (block->notify_id == event)) {
1339 wblock = iter;
1340 break;
1341 }
1342 }
1343
1344 if (!wblock)
1345 return;
1346
1347 /* If a driver is bound, then notify the driver. */
1348 if (test_bit(WMI_PROBED, &wblock->flags) && wblock->dev.dev.driver) {
1349 struct wmi_driver *driver = drv_to_wdrv(wblock->dev.dev.driver);
1350 struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL };
1351 acpi_status status;
1352
1353 if (!driver->no_notify_data) {
1354 status = get_event_data(wblock, &evdata);
1355 if (ACPI_FAILURE(status)) {
1356 dev_warn(&wblock->dev.dev, "failed to get event data\n");
1357 return;
1358 }
1359 }
1360
1361 if (driver->notify)
1362 driver->notify(&wblock->dev, evdata.pointer);
1363
1364 kfree(evdata.pointer);
1365 } else if (wblock->handler) {
1366 /* Legacy handler */
1367 wblock->handler(event, wblock->handler_data);
1368 }
1369
1370 if (debug_event)
1371 pr_info("DEBUG: GUID %pUL event 0x%02X\n", &wblock->gblock.guid, event);
1372
1373 acpi_bus_generate_netlink_event(
1374 wblock->acpi_device->pnp.device_class,
1375 dev_name(&wblock->dev.dev),
1376 event, 0);
1377}
1378
1379static int acpi_wmi_remove(struct platform_device *device)
1380{
1381 struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev);
1382
1383 acpi_remove_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY,
1384 acpi_wmi_notify_handler);
1385 acpi_remove_address_space_handler(acpi_device->handle,
1386 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
1387 wmi_free_devices(acpi_device);
1388 device_unregister(dev_get_drvdata(&device->dev));
1389
1390 return 0;
1391}
1392
1393static int acpi_wmi_probe(struct platform_device *device)
1394{
1395 struct acpi_device *acpi_device;
1396 struct device *wmi_bus_dev;
1397 acpi_status status;
1398 int error;
1399
1400 acpi_device = ACPI_COMPANION(&device->dev);
1401 if (!acpi_device) {
1402 dev_err(&device->dev, "ACPI companion is missing\n");
1403 return -ENODEV;
1404 }
1405
1406 status = acpi_install_address_space_handler(acpi_device->handle,
1407 ACPI_ADR_SPACE_EC,
1408 &acpi_wmi_ec_space_handler,
1409 NULL, NULL);
1410 if (ACPI_FAILURE(status)) {
1411 dev_err(&device->dev, "Error installing EC region handler\n");
1412 return -ENODEV;
1413 }
1414
1415 status = acpi_install_notify_handler(acpi_device->handle,
1416 ACPI_ALL_NOTIFY,
1417 acpi_wmi_notify_handler,
1418 NULL);
1419 if (ACPI_FAILURE(status)) {
1420 dev_err(&device->dev, "Error installing notify handler\n");
1421 error = -ENODEV;
1422 goto err_remove_ec_handler;
1423 }
1424
1425 wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0),
1426 NULL, "wmi_bus-%s", dev_name(&device->dev));
1427 if (IS_ERR(wmi_bus_dev)) {
1428 error = PTR_ERR(wmi_bus_dev);
1429 goto err_remove_notify_handler;
1430 }
1431 dev_set_drvdata(&device->dev, wmi_bus_dev);
1432
1433 error = parse_wdg(wmi_bus_dev, acpi_device);
1434 if (error) {
1435 pr_err("Failed to parse WDG method\n");
1436 goto err_remove_busdev;
1437 }
1438
1439 return 0;
1440
1441err_remove_busdev:
1442 device_unregister(wmi_bus_dev);
1443
1444err_remove_notify_handler:
1445 acpi_remove_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY,
1446 acpi_wmi_notify_handler);
1447
1448err_remove_ec_handler:
1449 acpi_remove_address_space_handler(acpi_device->handle,
1450 ACPI_ADR_SPACE_EC,
1451 &acpi_wmi_ec_space_handler);
1452
1453 return error;
1454}
1455
1456int __must_check __wmi_driver_register(struct wmi_driver *driver,
1457 struct module *owner)
1458{
1459 driver->driver.owner = owner;
1460 driver->driver.bus = &wmi_bus_type;
1461
1462 return driver_register(&driver->driver);
1463}
1464EXPORT_SYMBOL(__wmi_driver_register);
1465
1466void wmi_driver_unregister(struct wmi_driver *driver)
1467{
1468 driver_unregister(&driver->driver);
1469}
1470EXPORT_SYMBOL(wmi_driver_unregister);
1471
1472static struct platform_driver acpi_wmi_driver = {
1473 .driver = {
1474 .name = "acpi-wmi",
1475 .acpi_match_table = wmi_device_ids,
1476 },
1477 .probe = acpi_wmi_probe,
1478 .remove = acpi_wmi_remove,
1479};
1480
1481static int __init acpi_wmi_init(void)
1482{
1483 int error;
1484
1485 if (acpi_disabled)
1486 return -ENODEV;
1487
1488 error = class_register(&wmi_bus_class);
1489 if (error)
1490 return error;
1491
1492 error = bus_register(&wmi_bus_type);
1493 if (error)
1494 goto err_unreg_class;
1495
1496 error = platform_driver_register(&acpi_wmi_driver);
1497 if (error) {
1498 pr_err("Error loading mapper\n");
1499 goto err_unreg_bus;
1500 }
1501
1502 return 0;
1503
1504err_unreg_bus:
1505 bus_unregister(&wmi_bus_type);
1506
1507err_unreg_class:
1508 class_unregister(&wmi_bus_class);
1509
1510 return error;
1511}
1512
1513static void __exit acpi_wmi_exit(void)
1514{
1515 platform_driver_unregister(&acpi_wmi_driver);
1516 bus_unregister(&wmi_bus_type);
1517 class_unregister(&wmi_bus_class);
1518}
1519
1520subsys_initcall_sync(acpi_wmi_init);
1521module_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/list.h>
26#include <linux/module.h>
27#include <linux/platform_device.h>
28#include <linux/rwsem.h>
29#include <linux/slab.h>
30#include <linux/sysfs.h>
31#include <linux/types.h>
32#include <linux/uuid.h>
33#include <linux/wmi.h>
34#include <linux/fs.h>
35
36MODULE_AUTHOR("Carlos Corbacho");
37MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
38MODULE_LICENSE("GPL");
39
40static LIST_HEAD(wmi_block_list);
41
42struct guid_block {
43 guid_t guid;
44 union {
45 char object_id[2];
46 struct {
47 unsigned char notify_id;
48 unsigned char reserved;
49 };
50 };
51 u8 instance_count;
52 u8 flags;
53} __packed;
54static_assert(sizeof(typeof_member(struct guid_block, guid)) == 16);
55static_assert(sizeof(struct guid_block) == 20);
56static_assert(__alignof__(struct guid_block) == 1);
57
58enum { /* wmi_block flags */
59 WMI_READ_TAKES_NO_ARGS,
60};
61
62struct wmi_block {
63 struct wmi_device dev;
64 struct list_head list;
65 struct guid_block gblock;
66 struct acpi_device *acpi_device;
67 struct rw_semaphore notify_lock; /* Protects notify callback add/remove */
68 wmi_notify_handler handler;
69 void *handler_data;
70 bool driver_ready;
71 unsigned long flags;
72};
73
74
75/*
76 * If the GUID data block is marked as expensive, we must enable and
77 * explicitily disable data collection.
78 */
79#define ACPI_WMI_EXPENSIVE BIT(0)
80#define ACPI_WMI_METHOD BIT(1) /* GUID is a method */
81#define ACPI_WMI_STRING BIT(2) /* GUID takes & returns a string */
82#define ACPI_WMI_EVENT BIT(3) /* GUID is an event */
83
84static const struct acpi_device_id wmi_device_ids[] = {
85 {"PNP0C14", 0},
86 {"pnp0c14", 0},
87 { }
88};
89MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
90
91/* allow duplicate GUIDs as these device drivers use struct wmi_driver */
92static const char * const allow_duplicates[] = {
93 "05901221-D566-11D1-B2F0-00A0C9062910", /* wmi-bmof */
94 "8A42EA14-4F2A-FD45-6422-0087F7A7E608", /* dell-wmi-ddv */
95 "44FADEB1-B204-40F2-8581-394BBDC1B651", /* intel-wmi-sbl-fw-update */
96 "86CCFD48-205E-4A77-9C48-2021CBEDE341", /* intel-wmi-thunderbolt */
97 "F1DDEE52-063C-4784-A11E-8A06684B9B01", /* dell-smm-hwmon */
98 NULL
99};
100
101#define dev_to_wblock(__dev) container_of_const(__dev, struct wmi_block, dev.dev)
102#define dev_to_wdev(__dev) container_of_const(__dev, struct wmi_device, dev)
103
104/*
105 * GUID parsing functions
106 */
107
108static bool guid_parse_and_compare(const char *string, const guid_t *guid)
109{
110 guid_t guid_input;
111
112 if (guid_parse(string, &guid_input))
113 return false;
114
115 return guid_equal(&guid_input, guid);
116}
117
118static const void *find_guid_context(struct wmi_block *wblock,
119 struct wmi_driver *wdriver)
120{
121 const struct wmi_device_id *id;
122
123 id = wdriver->id_table;
124 if (!id)
125 return NULL;
126
127 while (*id->guid_string) {
128 if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid))
129 return id->context;
130 id++;
131 }
132 return NULL;
133}
134
135static int get_subobj_info(acpi_handle handle, const char *pathname,
136 struct acpi_device_info **info)
137{
138 acpi_handle subobj_handle;
139 acpi_status status;
140
141 status = acpi_get_handle(handle, pathname, &subobj_handle);
142 if (status == AE_NOT_FOUND)
143 return -ENOENT;
144
145 if (ACPI_FAILURE(status))
146 return -EIO;
147
148 status = acpi_get_object_info(subobj_handle, info);
149 if (ACPI_FAILURE(status))
150 return -EIO;
151
152 return 0;
153}
154
155static acpi_status wmi_method_enable(struct wmi_block *wblock, bool enable)
156{
157 struct guid_block *block;
158 char method[5];
159 acpi_status status;
160 acpi_handle handle;
161
162 block = &wblock->gblock;
163 handle = wblock->acpi_device->handle;
164
165 snprintf(method, 5, "WE%02X", block->notify_id);
166 status = acpi_execute_simple_method(handle, method, enable);
167 if (status == AE_NOT_FOUND)
168 return AE_OK;
169
170 return status;
171}
172
173#define WMI_ACPI_METHOD_NAME_SIZE 5
174
175static inline void get_acpi_method_name(const struct wmi_block *wblock,
176 const char method,
177 char buffer[static WMI_ACPI_METHOD_NAME_SIZE])
178{
179 static_assert(ARRAY_SIZE(wblock->gblock.object_id) == 2);
180 static_assert(WMI_ACPI_METHOD_NAME_SIZE >= 5);
181
182 buffer[0] = 'W';
183 buffer[1] = method;
184 buffer[2] = wblock->gblock.object_id[0];
185 buffer[3] = wblock->gblock.object_id[1];
186 buffer[4] = '\0';
187}
188
189static inline acpi_object_type get_param_acpi_type(const struct wmi_block *wblock)
190{
191 if (wblock->gblock.flags & ACPI_WMI_STRING)
192 return ACPI_TYPE_STRING;
193 else
194 return ACPI_TYPE_BUFFER;
195}
196
197static acpi_status get_event_data(const struct wmi_block *wblock, struct acpi_buffer *out)
198{
199 union acpi_object param = {
200 .integer = {
201 .type = ACPI_TYPE_INTEGER,
202 .value = wblock->gblock.notify_id,
203 }
204 };
205 struct acpi_object_list input = {
206 .count = 1,
207 .pointer = ¶m,
208 };
209
210 return acpi_evaluate_object(wblock->acpi_device->handle, "_WED", &input, out);
211}
212
213static int wmidev_match_guid(struct device *dev, const void *data)
214{
215 struct wmi_block *wblock = dev_to_wblock(dev);
216 const guid_t *guid = data;
217
218 if (guid_equal(guid, &wblock->gblock.guid))
219 return 1;
220
221 return 0;
222}
223
224static int wmidev_match_notify_id(struct device *dev, const void *data)
225{
226 struct wmi_block *wblock = dev_to_wblock(dev);
227 const u32 *notify_id = data;
228
229 if (wblock->gblock.flags & ACPI_WMI_EVENT && wblock->gblock.notify_id == *notify_id)
230 return 1;
231
232 return 0;
233}
234
235static struct bus_type wmi_bus_type;
236
237static struct wmi_device *wmi_find_device_by_guid(const char *guid_string)
238{
239 struct device *dev;
240 guid_t guid;
241 int ret;
242
243 ret = guid_parse(guid_string, &guid);
244 if (ret < 0)
245 return ERR_PTR(ret);
246
247 dev = bus_find_device(&wmi_bus_type, NULL, &guid, wmidev_match_guid);
248 if (!dev)
249 return ERR_PTR(-ENODEV);
250
251 return dev_to_wdev(dev);
252}
253
254static struct wmi_device *wmi_find_event_by_notify_id(const u32 notify_id)
255{
256 struct device *dev;
257
258 dev = bus_find_device(&wmi_bus_type, NULL, ¬ify_id, wmidev_match_notify_id);
259 if (!dev)
260 return ERR_PTR(-ENODEV);
261
262 return to_wmi_device(dev);
263}
264
265static void wmi_device_put(struct wmi_device *wdev)
266{
267 put_device(&wdev->dev);
268}
269
270/*
271 * Exported WMI functions
272 */
273
274/**
275 * wmi_instance_count - Get number of WMI object instances
276 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
277 *
278 * Get the number of WMI object instances.
279 *
280 * Returns: Number of WMI object instances or negative error code.
281 */
282int wmi_instance_count(const char *guid_string)
283{
284 struct wmi_device *wdev;
285 int ret;
286
287 wdev = wmi_find_device_by_guid(guid_string);
288 if (IS_ERR(wdev))
289 return PTR_ERR(wdev);
290
291 ret = wmidev_instance_count(wdev);
292 wmi_device_put(wdev);
293
294 return ret;
295}
296EXPORT_SYMBOL_GPL(wmi_instance_count);
297
298/**
299 * wmidev_instance_count - Get number of WMI object instances
300 * @wdev: A wmi bus device from a driver
301 *
302 * Get the number of WMI object instances.
303 *
304 * Returns: Number of WMI object instances.
305 */
306u8 wmidev_instance_count(struct wmi_device *wdev)
307{
308 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
309
310 return wblock->gblock.instance_count;
311}
312EXPORT_SYMBOL_GPL(wmidev_instance_count);
313
314/**
315 * wmi_evaluate_method - Evaluate a WMI method (deprecated)
316 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
317 * @instance: Instance index
318 * @method_id: Method ID to call
319 * @in: Buffer containing input for the method call
320 * @out: Empty buffer to return the method results
321 *
322 * Call an ACPI-WMI method, the caller must free @out.
323 *
324 * Return: acpi_status signaling success or error.
325 */
326acpi_status wmi_evaluate_method(const char *guid_string, u8 instance, u32 method_id,
327 const struct acpi_buffer *in, struct acpi_buffer *out)
328{
329 struct wmi_device *wdev;
330 acpi_status status;
331
332 wdev = wmi_find_device_by_guid(guid_string);
333 if (IS_ERR(wdev))
334 return AE_ERROR;
335
336 status = wmidev_evaluate_method(wdev, instance, method_id, in, out);
337
338 wmi_device_put(wdev);
339
340 return status;
341}
342EXPORT_SYMBOL_GPL(wmi_evaluate_method);
343
344/**
345 * wmidev_evaluate_method - Evaluate a WMI method
346 * @wdev: A wmi bus device from a driver
347 * @instance: Instance index
348 * @method_id: Method ID to call
349 * @in: Buffer containing input for the method call
350 * @out: Empty buffer to return the method results
351 *
352 * Call an ACPI-WMI method, the caller must free @out.
353 *
354 * Return: acpi_status signaling success or error.
355 */
356acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance, u32 method_id,
357 const struct acpi_buffer *in, struct acpi_buffer *out)
358{
359 struct guid_block *block;
360 struct wmi_block *wblock;
361 acpi_handle handle;
362 struct acpi_object_list input;
363 union acpi_object params[3];
364 char method[WMI_ACPI_METHOD_NAME_SIZE];
365
366 wblock = container_of(wdev, struct wmi_block, dev);
367 block = &wblock->gblock;
368 handle = wblock->acpi_device->handle;
369
370 if (!(block->flags & ACPI_WMI_METHOD))
371 return AE_BAD_DATA;
372
373 if (block->instance_count <= instance)
374 return AE_BAD_PARAMETER;
375
376 input.count = 2;
377 input.pointer = params;
378 params[0].type = ACPI_TYPE_INTEGER;
379 params[0].integer.value = instance;
380 params[1].type = ACPI_TYPE_INTEGER;
381 params[1].integer.value = method_id;
382
383 if (in) {
384 input.count = 3;
385
386 params[2].type = get_param_acpi_type(wblock);
387 params[2].buffer.length = in->length;
388 params[2].buffer.pointer = in->pointer;
389 }
390
391 get_acpi_method_name(wblock, 'M', method);
392
393 return acpi_evaluate_object(handle, method, &input, out);
394}
395EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
396
397static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
398 struct acpi_buffer *out)
399{
400 struct guid_block *block;
401 acpi_handle handle;
402 acpi_status status, wc_status = AE_ERROR;
403 struct acpi_object_list input;
404 union acpi_object wq_params[1];
405 char wc_method[WMI_ACPI_METHOD_NAME_SIZE];
406 char method[WMI_ACPI_METHOD_NAME_SIZE];
407
408 if (!out)
409 return AE_BAD_PARAMETER;
410
411 block = &wblock->gblock;
412 handle = wblock->acpi_device->handle;
413
414 if (block->instance_count <= instance)
415 return AE_BAD_PARAMETER;
416
417 /* Check GUID is a data block */
418 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
419 return AE_ERROR;
420
421 input.count = 1;
422 input.pointer = wq_params;
423 wq_params[0].type = ACPI_TYPE_INTEGER;
424 wq_params[0].integer.value = instance;
425
426 if (instance == 0 && test_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags))
427 input.count = 0;
428
429 /*
430 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
431 * enable collection.
432 */
433 if (block->flags & ACPI_WMI_EXPENSIVE) {
434 get_acpi_method_name(wblock, 'C', wc_method);
435
436 /*
437 * Some GUIDs break the specification by declaring themselves
438 * expensive, but have no corresponding WCxx method. So we
439 * should not fail if this happens.
440 */
441 wc_status = acpi_execute_simple_method(handle, wc_method, 1);
442 }
443
444 get_acpi_method_name(wblock, 'Q', method);
445 status = acpi_evaluate_object(handle, method, &input, out);
446
447 /*
448 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
449 * the WQxx method failed - we should disable collection anyway.
450 */
451 if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
452 /*
453 * Ignore whether this WCxx call succeeds or not since
454 * the previously executed WQxx method call might have
455 * succeeded, and returning the failing status code
456 * of this call would throw away the result of the WQxx
457 * call, potentially leaking memory.
458 */
459 acpi_execute_simple_method(handle, wc_method, 0);
460 }
461
462 return status;
463}
464
465/**
466 * wmi_query_block - Return contents of a WMI block (deprecated)
467 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
468 * @instance: Instance index
469 * @out: Empty buffer to return the contents of the data block to
470 *
471 * Query a ACPI-WMI block, the caller must free @out.
472 *
473 * Return: ACPI object containing the content of the WMI block.
474 */
475acpi_status wmi_query_block(const char *guid_string, u8 instance,
476 struct acpi_buffer *out)
477{
478 struct wmi_block *wblock;
479 struct wmi_device *wdev;
480 acpi_status status;
481
482 wdev = wmi_find_device_by_guid(guid_string);
483 if (IS_ERR(wdev))
484 return AE_ERROR;
485
486 wblock = container_of(wdev, struct wmi_block, dev);
487 status = __query_block(wblock, instance, out);
488
489 wmi_device_put(wdev);
490
491 return status;
492}
493EXPORT_SYMBOL_GPL(wmi_query_block);
494
495/**
496 * wmidev_block_query - Return contents of a WMI block
497 * @wdev: A wmi bus device from a driver
498 * @instance: Instance index
499 *
500 * Query an ACPI-WMI block, the caller must free the result.
501 *
502 * Return: ACPI object containing the content of the WMI block.
503 */
504union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
505{
506 struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
507 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
508
509 if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
510 return NULL;
511
512 return out.pointer;
513}
514EXPORT_SYMBOL_GPL(wmidev_block_query);
515
516/**
517 * wmi_set_block - Write to a WMI block (deprecated)
518 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
519 * @instance: Instance index
520 * @in: Buffer containing new values for the data block
521 *
522 * Write the contents of the input buffer to an ACPI-WMI data block.
523 *
524 * Return: acpi_status signaling success or error.
525 */
526acpi_status wmi_set_block(const char *guid_string, u8 instance, const struct acpi_buffer *in)
527{
528 struct wmi_device *wdev;
529 acpi_status status;
530
531 wdev = wmi_find_device_by_guid(guid_string);
532 if (IS_ERR(wdev))
533 return AE_ERROR;
534
535 status = wmidev_block_set(wdev, instance, in);
536 wmi_device_put(wdev);
537
538 return status;
539}
540EXPORT_SYMBOL_GPL(wmi_set_block);
541
542/**
543 * wmidev_block_set - Write to a WMI block
544 * @wdev: A wmi bus device from a driver
545 * @instance: Instance index
546 * @in: Buffer containing new values for the data block
547 *
548 * Write contents of the input buffer to an ACPI-WMI data block.
549 *
550 * Return: acpi_status signaling success or error.
551 */
552acpi_status wmidev_block_set(struct wmi_device *wdev, u8 instance, const struct acpi_buffer *in)
553{
554 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
555 acpi_handle handle = wblock->acpi_device->handle;
556 struct guid_block *block = &wblock->gblock;
557 char method[WMI_ACPI_METHOD_NAME_SIZE];
558 struct acpi_object_list input;
559 union acpi_object params[2];
560
561 if (!in)
562 return AE_BAD_DATA;
563
564 if (block->instance_count <= instance)
565 return AE_BAD_PARAMETER;
566
567 /* Check GUID is a data block */
568 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
569 return AE_ERROR;
570
571 input.count = 2;
572 input.pointer = params;
573 params[0].type = ACPI_TYPE_INTEGER;
574 params[0].integer.value = instance;
575 params[1].type = get_param_acpi_type(wblock);
576 params[1].buffer.length = in->length;
577 params[1].buffer.pointer = in->pointer;
578
579 get_acpi_method_name(wblock, 'S', method);
580
581 return acpi_evaluate_object(handle, method, &input, NULL);
582}
583EXPORT_SYMBOL_GPL(wmidev_block_set);
584
585/**
586 * wmi_install_notify_handler - Register handler for WMI events (deprecated)
587 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
588 * @handler: Function to handle notifications
589 * @data: Data to be returned to handler when event is fired
590 *
591 * Register a handler for events sent to the ACPI-WMI mapper device.
592 *
593 * Return: acpi_status signaling success or error.
594 */
595acpi_status wmi_install_notify_handler(const char *guid,
596 wmi_notify_handler handler,
597 void *data)
598{
599 struct wmi_block *wblock;
600 struct wmi_device *wdev;
601 acpi_status status;
602
603 wdev = wmi_find_device_by_guid(guid);
604 if (IS_ERR(wdev))
605 return AE_ERROR;
606
607 wblock = container_of(wdev, struct wmi_block, dev);
608
609 down_write(&wblock->notify_lock);
610 if (wblock->handler) {
611 status = AE_ALREADY_ACQUIRED;
612 } else {
613 wblock->handler = handler;
614 wblock->handler_data = data;
615
616 if (ACPI_FAILURE(wmi_method_enable(wblock, true)))
617 dev_warn(&wblock->dev.dev, "Failed to enable device\n");
618
619 status = AE_OK;
620 }
621 up_write(&wblock->notify_lock);
622
623 wmi_device_put(wdev);
624
625 return status;
626}
627EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
628
629/**
630 * wmi_remove_notify_handler - Unregister handler for WMI events (deprecated)
631 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
632 *
633 * Unregister handler for events sent to the ACPI-WMI mapper device.
634 *
635 * Return: acpi_status signaling success or error.
636 */
637acpi_status wmi_remove_notify_handler(const char *guid)
638{
639 struct wmi_block *wblock;
640 struct wmi_device *wdev;
641 acpi_status status;
642
643 wdev = wmi_find_device_by_guid(guid);
644 if (IS_ERR(wdev))
645 return AE_ERROR;
646
647 wblock = container_of(wdev, struct wmi_block, dev);
648
649 down_write(&wblock->notify_lock);
650 if (!wblock->handler) {
651 status = AE_NULL_ENTRY;
652 } else {
653 if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
654 dev_warn(&wblock->dev.dev, "Failed to disable device\n");
655
656 wblock->handler = NULL;
657 wblock->handler_data = NULL;
658
659 status = AE_OK;
660 }
661 up_write(&wblock->notify_lock);
662
663 wmi_device_put(wdev);
664
665 return status;
666}
667EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
668
669/**
670 * wmi_get_event_data - Get WMI data associated with an event (deprecated)
671 *
672 * @event: Event to find
673 * @out: Buffer to hold event data
674 *
675 * Get extra data associated with an WMI event, the caller needs to free @out.
676 *
677 * Return: acpi_status signaling success or error.
678 */
679acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
680{
681 struct wmi_block *wblock;
682 struct wmi_device *wdev;
683 acpi_status status;
684
685 wdev = wmi_find_event_by_notify_id(event);
686 if (IS_ERR(wdev))
687 return AE_NOT_FOUND;
688
689 wblock = container_of(wdev, struct wmi_block, dev);
690 status = get_event_data(wblock, out);
691
692 wmi_device_put(wdev);
693
694 return status;
695}
696EXPORT_SYMBOL_GPL(wmi_get_event_data);
697
698/**
699 * wmi_has_guid - Check if a GUID is available
700 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
701 *
702 * Check if a given GUID is defined by _WDG.
703 *
704 * Return: True if GUID is available, false otherwise.
705 */
706bool wmi_has_guid(const char *guid_string)
707{
708 struct wmi_device *wdev;
709
710 wdev = wmi_find_device_by_guid(guid_string);
711 if (IS_ERR(wdev))
712 return false;
713
714 wmi_device_put(wdev);
715
716 return true;
717}
718EXPORT_SYMBOL_GPL(wmi_has_guid);
719
720/**
721 * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID (deprecated)
722 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
723 *
724 * Find the _UID of ACPI device associated with this WMI GUID.
725 *
726 * Return: The ACPI _UID field value or NULL if the WMI GUID was not found.
727 */
728char *wmi_get_acpi_device_uid(const char *guid_string)
729{
730 struct wmi_block *wblock;
731 struct wmi_device *wdev;
732 char *uid;
733
734 wdev = wmi_find_device_by_guid(guid_string);
735 if (IS_ERR(wdev))
736 return NULL;
737
738 wblock = container_of(wdev, struct wmi_block, dev);
739 uid = acpi_device_uid(wblock->acpi_device);
740
741 wmi_device_put(wdev);
742
743 return uid;
744}
745EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
746
747static inline struct wmi_driver *drv_to_wdrv(struct device_driver *drv)
748{
749 return container_of(drv, struct wmi_driver, driver);
750}
751
752/*
753 * sysfs interface
754 */
755static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
756 char *buf)
757{
758 struct wmi_block *wblock = dev_to_wblock(dev);
759
760 return sysfs_emit(buf, "wmi:%pUL\n", &wblock->gblock.guid);
761}
762static DEVICE_ATTR_RO(modalias);
763
764static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
765 char *buf)
766{
767 struct wmi_block *wblock = dev_to_wblock(dev);
768
769 return sysfs_emit(buf, "%pUL\n", &wblock->gblock.guid);
770}
771static DEVICE_ATTR_RO(guid);
772
773static ssize_t instance_count_show(struct device *dev,
774 struct device_attribute *attr, char *buf)
775{
776 struct wmi_block *wblock = dev_to_wblock(dev);
777
778 return sysfs_emit(buf, "%d\n", (int)wblock->gblock.instance_count);
779}
780static DEVICE_ATTR_RO(instance_count);
781
782static ssize_t expensive_show(struct device *dev,
783 struct device_attribute *attr, char *buf)
784{
785 struct wmi_block *wblock = dev_to_wblock(dev);
786
787 return sysfs_emit(buf, "%d\n",
788 (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
789}
790static DEVICE_ATTR_RO(expensive);
791
792static struct attribute *wmi_attrs[] = {
793 &dev_attr_modalias.attr,
794 &dev_attr_guid.attr,
795 &dev_attr_instance_count.attr,
796 &dev_attr_expensive.attr,
797 NULL
798};
799ATTRIBUTE_GROUPS(wmi);
800
801static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
802 char *buf)
803{
804 struct wmi_block *wblock = dev_to_wblock(dev);
805
806 return sysfs_emit(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
807}
808static DEVICE_ATTR_RO(notify_id);
809
810static struct attribute *wmi_event_attrs[] = {
811 &dev_attr_notify_id.attr,
812 NULL
813};
814ATTRIBUTE_GROUPS(wmi_event);
815
816static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
817 char *buf)
818{
819 struct wmi_block *wblock = dev_to_wblock(dev);
820
821 return sysfs_emit(buf, "%c%c\n", wblock->gblock.object_id[0],
822 wblock->gblock.object_id[1]);
823}
824static DEVICE_ATTR_RO(object_id);
825
826static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
827 char *buf)
828{
829 struct wmi_device *wdev = dev_to_wdev(dev);
830
831 return sysfs_emit(buf, "%d\n", (int)wdev->setable);
832}
833static DEVICE_ATTR_RO(setable);
834
835static struct attribute *wmi_data_attrs[] = {
836 &dev_attr_object_id.attr,
837 &dev_attr_setable.attr,
838 NULL
839};
840ATTRIBUTE_GROUPS(wmi_data);
841
842static struct attribute *wmi_method_attrs[] = {
843 &dev_attr_object_id.attr,
844 NULL
845};
846ATTRIBUTE_GROUPS(wmi_method);
847
848static int wmi_dev_uevent(const struct device *dev, struct kobj_uevent_env *env)
849{
850 const struct wmi_block *wblock = dev_to_wblock(dev);
851
852 if (add_uevent_var(env, "MODALIAS=wmi:%pUL", &wblock->gblock.guid))
853 return -ENOMEM;
854
855 if (add_uevent_var(env, "WMI_GUID=%pUL", &wblock->gblock.guid))
856 return -ENOMEM;
857
858 return 0;
859}
860
861static void wmi_dev_release(struct device *dev)
862{
863 struct wmi_block *wblock = dev_to_wblock(dev);
864
865 kfree(wblock);
866}
867
868static int wmi_dev_match(struct device *dev, struct device_driver *driver)
869{
870 struct wmi_driver *wmi_driver = drv_to_wdrv(driver);
871 struct wmi_block *wblock = dev_to_wblock(dev);
872 const struct wmi_device_id *id = wmi_driver->id_table;
873
874 if (id == NULL)
875 return 0;
876
877 while (*id->guid_string) {
878 if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid))
879 return 1;
880
881 id++;
882 }
883
884 return 0;
885}
886
887static int wmi_dev_probe(struct device *dev)
888{
889 struct wmi_block *wblock = dev_to_wblock(dev);
890 struct wmi_driver *wdriver = drv_to_wdrv(dev->driver);
891 int ret = 0;
892
893 if (ACPI_FAILURE(wmi_method_enable(wblock, true)))
894 dev_warn(dev, "failed to enable device -- probing anyway\n");
895
896 if (wdriver->probe) {
897 ret = wdriver->probe(dev_to_wdev(dev),
898 find_guid_context(wblock, wdriver));
899 if (ret) {
900 if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
901 dev_warn(dev, "Failed to disable device\n");
902
903 return ret;
904 }
905 }
906
907 down_write(&wblock->notify_lock);
908 wblock->driver_ready = true;
909 up_write(&wblock->notify_lock);
910
911 return 0;
912}
913
914static void wmi_dev_remove(struct device *dev)
915{
916 struct wmi_block *wblock = dev_to_wblock(dev);
917 struct wmi_driver *wdriver = drv_to_wdrv(dev->driver);
918
919 down_write(&wblock->notify_lock);
920 wblock->driver_ready = false;
921 up_write(&wblock->notify_lock);
922
923 if (wdriver->remove)
924 wdriver->remove(dev_to_wdev(dev));
925
926 if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
927 dev_warn(dev, "failed to disable device\n");
928}
929
930static struct class wmi_bus_class = {
931 .name = "wmi_bus",
932};
933
934static struct bus_type wmi_bus_type = {
935 .name = "wmi",
936 .dev_groups = wmi_groups,
937 .match = wmi_dev_match,
938 .uevent = wmi_dev_uevent,
939 .probe = wmi_dev_probe,
940 .remove = wmi_dev_remove,
941};
942
943static const struct device_type wmi_type_event = {
944 .name = "event",
945 .groups = wmi_event_groups,
946 .release = wmi_dev_release,
947};
948
949static const struct device_type wmi_type_method = {
950 .name = "method",
951 .groups = wmi_method_groups,
952 .release = wmi_dev_release,
953};
954
955static const struct device_type wmi_type_data = {
956 .name = "data",
957 .groups = wmi_data_groups,
958 .release = wmi_dev_release,
959};
960
961/*
962 * _WDG is a static list that is only parsed at startup,
963 * so it's safe to count entries without extra protection.
964 */
965static int guid_count(const guid_t *guid)
966{
967 struct wmi_block *wblock;
968 int count = 0;
969
970 list_for_each_entry(wblock, &wmi_block_list, list) {
971 if (guid_equal(&wblock->gblock.guid, guid))
972 count++;
973 }
974
975 return count;
976}
977
978static int wmi_create_device(struct device *wmi_bus_dev,
979 struct wmi_block *wblock,
980 struct acpi_device *device)
981{
982 struct acpi_device_info *info;
983 char method[WMI_ACPI_METHOD_NAME_SIZE];
984 int result;
985 uint count;
986
987 if (wblock->gblock.flags & ACPI_WMI_EVENT) {
988 wblock->dev.dev.type = &wmi_type_event;
989 goto out_init;
990 }
991
992 if (wblock->gblock.flags & ACPI_WMI_METHOD) {
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 result = get_subobj_info(device->handle, method, &info);
1004
1005 if (result) {
1006 dev_warn(wmi_bus_dev,
1007 "%s data block query control method not found\n",
1008 method);
1009 return result;
1010 }
1011
1012 wblock->dev.dev.type = &wmi_type_data;
1013
1014 /*
1015 * The Microsoft documentation specifically states:
1016 *
1017 * Data blocks registered with only a single instance
1018 * can ignore the parameter.
1019 *
1020 * ACPICA will get mad at us if we call the method with the wrong number
1021 * of arguments, so check what our method expects. (On some Dell
1022 * laptops, WQxx may not be a method at all.)
1023 */
1024 if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1025 set_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags);
1026
1027 kfree(info);
1028
1029 get_acpi_method_name(wblock, 'S', method);
1030 if (acpi_has_method(device->handle, method))
1031 wblock->dev.setable = true;
1032
1033 out_init:
1034 init_rwsem(&wblock->notify_lock);
1035 wblock->driver_ready = false;
1036 wblock->dev.dev.bus = &wmi_bus_type;
1037 wblock->dev.dev.parent = wmi_bus_dev;
1038
1039 count = guid_count(&wblock->gblock.guid);
1040 if (count)
1041 dev_set_name(&wblock->dev.dev, "%pUL-%d", &wblock->gblock.guid, count);
1042 else
1043 dev_set_name(&wblock->dev.dev, "%pUL", &wblock->gblock.guid);
1044
1045 device_initialize(&wblock->dev.dev);
1046
1047 return 0;
1048}
1049
1050static int wmi_add_device(struct platform_device *pdev, struct wmi_device *wdev)
1051{
1052 struct device_link *link;
1053
1054 /*
1055 * Many aggregate WMI drivers do not use -EPROBE_DEFER when they
1056 * are unable to find a WMI device during probe, instead they require
1057 * all WMI devices associated with an platform device to become available
1058 * at once. This device link thus prevents WMI drivers from probing until
1059 * the associated platform device has finished probing (and has registered
1060 * all discovered WMI devices).
1061 */
1062
1063 link = device_link_add(&wdev->dev, &pdev->dev, DL_FLAG_AUTOREMOVE_SUPPLIER);
1064 if (!link)
1065 return -EINVAL;
1066
1067 return device_add(&wdev->dev);
1068}
1069
1070static bool guid_already_parsed_for_legacy(struct acpi_device *device, const guid_t *guid)
1071{
1072 struct wmi_block *wblock;
1073
1074 list_for_each_entry(wblock, &wmi_block_list, list) {
1075 /* skip warning and register if we know the driver will use struct wmi_driver */
1076 for (int i = 0; allow_duplicates[i] != NULL; i++) {
1077 if (guid_parse_and_compare(allow_duplicates[i], guid))
1078 return false;
1079 }
1080 if (guid_equal(&wblock->gblock.guid, guid)) {
1081 /*
1082 * Because we historically didn't track the relationship
1083 * between GUIDs and ACPI nodes, we don't know whether
1084 * we need to suppress GUIDs that are unique on a
1085 * given node but duplicated across nodes.
1086 */
1087 dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
1088 guid, dev_name(&wblock->acpi_device->dev));
1089 return true;
1090 }
1091 }
1092
1093 return false;
1094}
1095
1096/*
1097 * Parse the _WDG method for the GUID data blocks
1098 */
1099static int parse_wdg(struct device *wmi_bus_dev, struct platform_device *pdev)
1100{
1101 struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
1102 struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1103 const struct guid_block *gblock;
1104 struct wmi_block *wblock;
1105 union acpi_object *obj;
1106 acpi_status status;
1107 u32 i, total;
1108 int retval;
1109
1110 status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1111 if (ACPI_FAILURE(status))
1112 return -ENXIO;
1113
1114 obj = out.pointer;
1115 if (!obj)
1116 return -ENXIO;
1117
1118 if (obj->type != ACPI_TYPE_BUFFER) {
1119 kfree(obj);
1120 return -ENXIO;
1121 }
1122
1123 gblock = (const struct guid_block *)obj->buffer.pointer;
1124 total = obj->buffer.length / sizeof(struct guid_block);
1125
1126 for (i = 0; i < total; i++) {
1127 if (!gblock[i].instance_count) {
1128 dev_info(wmi_bus_dev, FW_INFO "%pUL has zero instances\n", &gblock[i].guid);
1129 continue;
1130 }
1131
1132 if (guid_already_parsed_for_legacy(device, &gblock[i].guid))
1133 continue;
1134
1135 wblock = kzalloc(sizeof(*wblock), GFP_KERNEL);
1136 if (!wblock) {
1137 dev_err(wmi_bus_dev, "Failed to allocate %pUL\n", &gblock[i].guid);
1138 continue;
1139 }
1140
1141 wblock->acpi_device = device;
1142 wblock->gblock = gblock[i];
1143
1144 retval = wmi_create_device(wmi_bus_dev, wblock, device);
1145 if (retval) {
1146 kfree(wblock);
1147 continue;
1148 }
1149
1150 list_add_tail(&wblock->list, &wmi_block_list);
1151
1152 retval = wmi_add_device(pdev, &wblock->dev);
1153 if (retval) {
1154 dev_err(wmi_bus_dev, "failed to register %pUL\n",
1155 &wblock->gblock.guid);
1156
1157 list_del(&wblock->list);
1158 put_device(&wblock->dev.dev);
1159 }
1160 }
1161
1162 kfree(obj);
1163
1164 return 0;
1165}
1166
1167/*
1168 * WMI can have EmbeddedControl access regions. In which case, we just want to
1169 * hand these off to the EC driver.
1170 */
1171static acpi_status
1172acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1173 u32 bits, u64 *value,
1174 void *handler_context, void *region_context)
1175{
1176 int result = 0;
1177 u8 temp = 0;
1178
1179 if ((address > 0xFF) || !value)
1180 return AE_BAD_PARAMETER;
1181
1182 if (function != ACPI_READ && function != ACPI_WRITE)
1183 return AE_BAD_PARAMETER;
1184
1185 if (bits != 8)
1186 return AE_BAD_PARAMETER;
1187
1188 if (function == ACPI_READ) {
1189 result = ec_read(address, &temp);
1190 *value = temp;
1191 } else {
1192 temp = 0xff & *value;
1193 result = ec_write(address, temp);
1194 }
1195
1196 switch (result) {
1197 case -EINVAL:
1198 return AE_BAD_PARAMETER;
1199 case -ENODEV:
1200 return AE_NOT_FOUND;
1201 case -ETIME:
1202 return AE_TIME;
1203 default:
1204 return AE_OK;
1205 }
1206}
1207
1208static void wmi_notify_driver(struct wmi_block *wblock)
1209{
1210 struct wmi_driver *driver = drv_to_wdrv(wblock->dev.dev.driver);
1211 struct acpi_buffer data = { ACPI_ALLOCATE_BUFFER, NULL };
1212 acpi_status status;
1213
1214 if (!driver->no_notify_data) {
1215 status = get_event_data(wblock, &data);
1216 if (ACPI_FAILURE(status)) {
1217 dev_warn(&wblock->dev.dev, "Failed to get event data\n");
1218 return;
1219 }
1220 }
1221
1222 if (driver->notify)
1223 driver->notify(&wblock->dev, data.pointer);
1224
1225 kfree(data.pointer);
1226}
1227
1228static int wmi_notify_device(struct device *dev, void *data)
1229{
1230 struct wmi_block *wblock = dev_to_wblock(dev);
1231 u32 *event = data;
1232
1233 if (!(wblock->gblock.flags & ACPI_WMI_EVENT && wblock->gblock.notify_id == *event))
1234 return 0;
1235
1236 down_read(&wblock->notify_lock);
1237 /* The WMI driver notify handler conflicts with the legacy WMI handler.
1238 * Because of this the WMI driver notify handler takes precedence.
1239 */
1240 if (wblock->dev.dev.driver && wblock->driver_ready) {
1241 wmi_notify_driver(wblock);
1242 } else {
1243 if (wblock->handler)
1244 wblock->handler(*event, wblock->handler_data);
1245 }
1246 up_read(&wblock->notify_lock);
1247
1248 acpi_bus_generate_netlink_event(wblock->acpi_device->pnp.device_class,
1249 dev_name(&wblock->dev.dev), *event, 0);
1250
1251 return -EBUSY;
1252}
1253
1254static void acpi_wmi_notify_handler(acpi_handle handle, u32 event, void *context)
1255{
1256 struct device *wmi_bus_dev = context;
1257
1258 device_for_each_child(wmi_bus_dev, &event, wmi_notify_device);
1259}
1260
1261static int wmi_remove_device(struct device *dev, void *data)
1262{
1263 struct wmi_block *wblock = dev_to_wblock(dev);
1264
1265 list_del(&wblock->list);
1266 device_unregister(dev);
1267
1268 return 0;
1269}
1270
1271static void acpi_wmi_remove(struct platform_device *device)
1272{
1273 struct device *wmi_bus_device = dev_get_drvdata(&device->dev);
1274
1275 device_for_each_child_reverse(wmi_bus_device, NULL, wmi_remove_device);
1276}
1277
1278static void acpi_wmi_remove_notify_handler(void *data)
1279{
1280 struct acpi_device *acpi_device = data;
1281
1282 acpi_remove_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY, acpi_wmi_notify_handler);
1283}
1284
1285static void acpi_wmi_remove_address_space_handler(void *data)
1286{
1287 struct acpi_device *acpi_device = data;
1288
1289 acpi_remove_address_space_handler(acpi_device->handle, ACPI_ADR_SPACE_EC,
1290 &acpi_wmi_ec_space_handler);
1291}
1292
1293static void acpi_wmi_remove_bus_device(void *data)
1294{
1295 struct device *wmi_bus_dev = data;
1296
1297 device_unregister(wmi_bus_dev);
1298}
1299
1300static int acpi_wmi_probe(struct platform_device *device)
1301{
1302 struct acpi_device *acpi_device;
1303 struct device *wmi_bus_dev;
1304 acpi_status status;
1305 int error;
1306
1307 acpi_device = ACPI_COMPANION(&device->dev);
1308 if (!acpi_device) {
1309 dev_err(&device->dev, "ACPI companion is missing\n");
1310 return -ENODEV;
1311 }
1312
1313 wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0), NULL, "wmi_bus-%s",
1314 dev_name(&device->dev));
1315 if (IS_ERR(wmi_bus_dev))
1316 return PTR_ERR(wmi_bus_dev);
1317
1318 error = devm_add_action_or_reset(&device->dev, acpi_wmi_remove_bus_device, wmi_bus_dev);
1319 if (error < 0)
1320 return error;
1321
1322 dev_set_drvdata(&device->dev, wmi_bus_dev);
1323
1324 status = acpi_install_address_space_handler(acpi_device->handle,
1325 ACPI_ADR_SPACE_EC,
1326 &acpi_wmi_ec_space_handler,
1327 NULL, NULL);
1328 if (ACPI_FAILURE(status)) {
1329 dev_err(&device->dev, "Error installing EC region handler\n");
1330 return -ENODEV;
1331 }
1332 error = devm_add_action_or_reset(&device->dev, acpi_wmi_remove_address_space_handler,
1333 acpi_device);
1334 if (error < 0)
1335 return error;
1336
1337 status = acpi_install_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY,
1338 acpi_wmi_notify_handler, wmi_bus_dev);
1339 if (ACPI_FAILURE(status)) {
1340 dev_err(&device->dev, "Error installing notify handler\n");
1341 return -ENODEV;
1342 }
1343 error = devm_add_action_or_reset(&device->dev, acpi_wmi_remove_notify_handler,
1344 acpi_device);
1345 if (error < 0)
1346 return error;
1347
1348 error = parse_wdg(wmi_bus_dev, device);
1349 if (error) {
1350 pr_err("Failed to parse WDG method\n");
1351 return error;
1352 }
1353
1354 return 0;
1355}
1356
1357int __must_check __wmi_driver_register(struct wmi_driver *driver,
1358 struct module *owner)
1359{
1360 driver->driver.owner = owner;
1361 driver->driver.bus = &wmi_bus_type;
1362
1363 return driver_register(&driver->driver);
1364}
1365EXPORT_SYMBOL(__wmi_driver_register);
1366
1367/**
1368 * wmi_driver_unregister() - Unregister a WMI driver
1369 * @driver: WMI driver to unregister
1370 *
1371 * Unregisters a WMI driver from the WMI bus.
1372 */
1373void wmi_driver_unregister(struct wmi_driver *driver)
1374{
1375 driver_unregister(&driver->driver);
1376}
1377EXPORT_SYMBOL(wmi_driver_unregister);
1378
1379static struct platform_driver acpi_wmi_driver = {
1380 .driver = {
1381 .name = "acpi-wmi",
1382 .acpi_match_table = wmi_device_ids,
1383 },
1384 .probe = acpi_wmi_probe,
1385 .remove_new = acpi_wmi_remove,
1386};
1387
1388static int __init acpi_wmi_init(void)
1389{
1390 int error;
1391
1392 if (acpi_disabled)
1393 return -ENODEV;
1394
1395 error = class_register(&wmi_bus_class);
1396 if (error)
1397 return error;
1398
1399 error = bus_register(&wmi_bus_type);
1400 if (error)
1401 goto err_unreg_class;
1402
1403 error = platform_driver_register(&acpi_wmi_driver);
1404 if (error) {
1405 pr_err("Error loading mapper\n");
1406 goto err_unreg_bus;
1407 }
1408
1409 return 0;
1410
1411err_unreg_bus:
1412 bus_unregister(&wmi_bus_type);
1413
1414err_unreg_class:
1415 class_unregister(&wmi_bus_class);
1416
1417 return error;
1418}
1419
1420static void __exit acpi_wmi_exit(void)
1421{
1422 platform_driver_unregister(&acpi_wmi_driver);
1423 bus_unregister(&wmi_bus_type);
1424 class_unregister(&wmi_bus_class);
1425}
1426
1427subsys_initcall_sync(acpi_wmi_init);
1428module_exit(acpi_wmi_exit);