Loading...
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 WMI_GUID_DUPLICATED,
61 WMI_NO_EVENT_DATA,
62};
63
64struct wmi_block {
65 struct wmi_device dev;
66 struct list_head list;
67 struct guid_block gblock;
68 struct acpi_device *acpi_device;
69 struct rw_semaphore notify_lock; /* Protects notify callback add/remove */
70 wmi_notify_handler handler;
71 void *handler_data;
72 bool driver_ready;
73 unsigned long flags;
74};
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#define dev_to_wdev(__dev) container_of_const(__dev, struct wmi_device, dev)
95
96/*
97 * GUID parsing functions
98 */
99
100static bool guid_parse_and_compare(const char *string, const guid_t *guid)
101{
102 guid_t guid_input;
103
104 if (guid_parse(string, &guid_input))
105 return false;
106
107 return guid_equal(&guid_input, guid);
108}
109
110static const void *find_guid_context(struct wmi_block *wblock,
111 struct wmi_driver *wdriver)
112{
113 const struct wmi_device_id *id;
114
115 id = wdriver->id_table;
116 if (!id)
117 return NULL;
118
119 while (*id->guid_string) {
120 if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid))
121 return id->context;
122 id++;
123 }
124 return NULL;
125}
126
127static acpi_status wmi_method_enable(struct wmi_block *wblock, bool enable)
128{
129 struct guid_block *block;
130 char method[5];
131 acpi_status status;
132 acpi_handle handle;
133
134 block = &wblock->gblock;
135 handle = wblock->acpi_device->handle;
136
137 snprintf(method, 5, "WE%02X", block->notify_id);
138 status = acpi_execute_simple_method(handle, method, enable);
139 if (status == AE_NOT_FOUND)
140 return AE_OK;
141
142 return status;
143}
144
145#define WMI_ACPI_METHOD_NAME_SIZE 5
146
147static inline void get_acpi_method_name(const struct wmi_block *wblock,
148 const char method,
149 char buffer[static WMI_ACPI_METHOD_NAME_SIZE])
150{
151 static_assert(ARRAY_SIZE(wblock->gblock.object_id) == 2);
152 static_assert(WMI_ACPI_METHOD_NAME_SIZE >= 5);
153
154 buffer[0] = 'W';
155 buffer[1] = method;
156 buffer[2] = wblock->gblock.object_id[0];
157 buffer[3] = wblock->gblock.object_id[1];
158 buffer[4] = '\0';
159}
160
161static inline acpi_object_type get_param_acpi_type(const struct wmi_block *wblock)
162{
163 if (wblock->gblock.flags & ACPI_WMI_STRING)
164 return ACPI_TYPE_STRING;
165 else
166 return ACPI_TYPE_BUFFER;
167}
168
169static acpi_status get_event_data(const struct wmi_block *wblock, struct acpi_buffer *out)
170{
171 union acpi_object param = {
172 .integer = {
173 .type = ACPI_TYPE_INTEGER,
174 .value = wblock->gblock.notify_id,
175 }
176 };
177 struct acpi_object_list input = {
178 .count = 1,
179 .pointer = ¶m,
180 };
181
182 return acpi_evaluate_object(wblock->acpi_device->handle, "_WED", &input, out);
183}
184
185static int wmidev_match_guid(struct device *dev, const void *data)
186{
187 struct wmi_block *wblock = dev_to_wblock(dev);
188 const guid_t *guid = data;
189
190 /* Legacy GUID-based functions are restricted to only see
191 * a single WMI device for each GUID.
192 */
193 if (test_bit(WMI_GUID_DUPLICATED, &wblock->flags))
194 return 0;
195
196 if (guid_equal(guid, &wblock->gblock.guid))
197 return 1;
198
199 return 0;
200}
201
202static int wmidev_match_notify_id(struct device *dev, const void *data)
203{
204 struct wmi_block *wblock = dev_to_wblock(dev);
205 const u32 *notify_id = data;
206
207 /* Legacy GUID-based functions are restricted to only see
208 * a single WMI device for each GUID.
209 */
210 if (test_bit(WMI_GUID_DUPLICATED, &wblock->flags))
211 return 0;
212
213 if (wblock->gblock.flags & ACPI_WMI_EVENT && wblock->gblock.notify_id == *notify_id)
214 return 1;
215
216 return 0;
217}
218
219static const struct bus_type wmi_bus_type;
220
221static struct wmi_device *wmi_find_device_by_guid(const char *guid_string)
222{
223 struct device *dev;
224 guid_t guid;
225 int ret;
226
227 ret = guid_parse(guid_string, &guid);
228 if (ret < 0)
229 return ERR_PTR(ret);
230
231 dev = bus_find_device(&wmi_bus_type, NULL, &guid, wmidev_match_guid);
232 if (!dev)
233 return ERR_PTR(-ENODEV);
234
235 return dev_to_wdev(dev);
236}
237
238static struct wmi_device *wmi_find_event_by_notify_id(const u32 notify_id)
239{
240 struct device *dev;
241
242 dev = bus_find_device(&wmi_bus_type, NULL, ¬ify_id, wmidev_match_notify_id);
243 if (!dev)
244 return ERR_PTR(-ENODEV);
245
246 return to_wmi_device(dev);
247}
248
249static void wmi_device_put(struct wmi_device *wdev)
250{
251 put_device(&wdev->dev);
252}
253
254/*
255 * Exported WMI functions
256 */
257
258/**
259 * wmi_instance_count - Get number of WMI object instances
260 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
261 *
262 * Get the number of WMI object instances.
263 *
264 * Returns: Number of WMI object instances or negative error code.
265 */
266int wmi_instance_count(const char *guid_string)
267{
268 struct wmi_device *wdev;
269 int ret;
270
271 wdev = wmi_find_device_by_guid(guid_string);
272 if (IS_ERR(wdev))
273 return PTR_ERR(wdev);
274
275 ret = wmidev_instance_count(wdev);
276 wmi_device_put(wdev);
277
278 return ret;
279}
280EXPORT_SYMBOL_GPL(wmi_instance_count);
281
282/**
283 * wmidev_instance_count - Get number of WMI object instances
284 * @wdev: A wmi bus device from a driver
285 *
286 * Get the number of WMI object instances.
287 *
288 * Returns: Number of WMI object instances.
289 */
290u8 wmidev_instance_count(struct wmi_device *wdev)
291{
292 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
293
294 return wblock->gblock.instance_count;
295}
296EXPORT_SYMBOL_GPL(wmidev_instance_count);
297
298/**
299 * wmi_evaluate_method - Evaluate a WMI method (deprecated)
300 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
301 * @instance: Instance index
302 * @method_id: Method ID to call
303 * @in: Mandatory buffer containing input for the method call
304 * @out: Empty buffer to return the method results
305 *
306 * Call an ACPI-WMI method, the caller must free @out.
307 *
308 * Return: acpi_status signaling success or error.
309 */
310acpi_status wmi_evaluate_method(const char *guid_string, u8 instance, u32 method_id,
311 const struct acpi_buffer *in, struct acpi_buffer *out)
312{
313 struct wmi_device *wdev;
314 acpi_status status;
315
316 wdev = wmi_find_device_by_guid(guid_string);
317 if (IS_ERR(wdev))
318 return AE_ERROR;
319
320 status = wmidev_evaluate_method(wdev, instance, method_id, in, out);
321
322 wmi_device_put(wdev);
323
324 return status;
325}
326EXPORT_SYMBOL_GPL(wmi_evaluate_method);
327
328/**
329 * wmidev_evaluate_method - Evaluate a WMI method
330 * @wdev: A wmi bus device from a driver
331 * @instance: Instance index
332 * @method_id: Method ID to call
333 * @in: Mandatory buffer containing input for the method call
334 * @out: Empty buffer to return the method results
335 *
336 * Call an ACPI-WMI method, the caller must free @out.
337 *
338 * Return: acpi_status signaling success or error.
339 */
340acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance, u32 method_id,
341 const struct acpi_buffer *in, struct acpi_buffer *out)
342{
343 struct guid_block *block;
344 struct wmi_block *wblock;
345 acpi_handle handle;
346 struct acpi_object_list input;
347 union acpi_object params[3];
348 char method[WMI_ACPI_METHOD_NAME_SIZE];
349
350 wblock = container_of(wdev, struct wmi_block, dev);
351 block = &wblock->gblock;
352 handle = wblock->acpi_device->handle;
353
354 if (!in)
355 return AE_BAD_DATA;
356
357 if (!(block->flags & ACPI_WMI_METHOD))
358 return AE_BAD_DATA;
359
360 if (block->instance_count <= instance)
361 return AE_BAD_PARAMETER;
362
363 input.count = 3;
364 input.pointer = params;
365
366 params[0].type = ACPI_TYPE_INTEGER;
367 params[0].integer.value = instance;
368 params[1].type = ACPI_TYPE_INTEGER;
369 params[1].integer.value = method_id;
370 params[2].type = get_param_acpi_type(wblock);
371 params[2].buffer.length = in->length;
372 params[2].buffer.pointer = in->pointer;
373
374 get_acpi_method_name(wblock, 'M', method);
375
376 return acpi_evaluate_object(handle, method, &input, out);
377}
378EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
379
380static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
381 struct acpi_buffer *out)
382{
383 struct guid_block *block;
384 acpi_handle handle;
385 acpi_status status, wc_status = AE_ERROR;
386 struct acpi_object_list input;
387 union acpi_object wq_params[1];
388 char wc_method[WMI_ACPI_METHOD_NAME_SIZE];
389 char method[WMI_ACPI_METHOD_NAME_SIZE];
390
391 if (!out)
392 return AE_BAD_PARAMETER;
393
394 block = &wblock->gblock;
395 handle = wblock->acpi_device->handle;
396
397 if (block->instance_count <= instance)
398 return AE_BAD_PARAMETER;
399
400 /* Check GUID is a data block */
401 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
402 return AE_ERROR;
403
404 input.count = 1;
405 input.pointer = wq_params;
406 wq_params[0].type = ACPI_TYPE_INTEGER;
407 wq_params[0].integer.value = instance;
408
409 if (instance == 0 && test_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags))
410 input.count = 0;
411
412 /*
413 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
414 * enable collection.
415 */
416 if (block->flags & ACPI_WMI_EXPENSIVE) {
417 get_acpi_method_name(wblock, 'C', wc_method);
418
419 /*
420 * Some GUIDs break the specification by declaring themselves
421 * expensive, but have no corresponding WCxx method. So we
422 * should not fail if this happens.
423 */
424 wc_status = acpi_execute_simple_method(handle, wc_method, 1);
425 }
426
427 get_acpi_method_name(wblock, 'Q', method);
428 status = acpi_evaluate_object(handle, method, &input, out);
429
430 /*
431 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
432 * the WQxx method failed - we should disable collection anyway.
433 */
434 if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
435 /*
436 * Ignore whether this WCxx call succeeds or not since
437 * the previously executed WQxx method call might have
438 * succeeded, and returning the failing status code
439 * of this call would throw away the result of the WQxx
440 * call, potentially leaking memory.
441 */
442 acpi_execute_simple_method(handle, wc_method, 0);
443 }
444
445 return status;
446}
447
448/**
449 * wmi_query_block - Return contents of a WMI block (deprecated)
450 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
451 * @instance: Instance index
452 * @out: Empty buffer to return the contents of the data block to
453 *
454 * Query a ACPI-WMI block, the caller must free @out.
455 *
456 * Return: ACPI object containing the content of the WMI block.
457 */
458acpi_status wmi_query_block(const char *guid_string, u8 instance,
459 struct acpi_buffer *out)
460{
461 struct wmi_block *wblock;
462 struct wmi_device *wdev;
463 acpi_status status;
464
465 wdev = wmi_find_device_by_guid(guid_string);
466 if (IS_ERR(wdev))
467 return AE_ERROR;
468
469 wblock = container_of(wdev, struct wmi_block, dev);
470 status = __query_block(wblock, instance, out);
471
472 wmi_device_put(wdev);
473
474 return status;
475}
476EXPORT_SYMBOL_GPL(wmi_query_block);
477
478/**
479 * wmidev_block_query - Return contents of a WMI block
480 * @wdev: A wmi bus device from a driver
481 * @instance: Instance index
482 *
483 * Query an ACPI-WMI block, the caller must free the result.
484 *
485 * Return: ACPI object containing the content of the WMI block.
486 */
487union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
488{
489 struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
490 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
491
492 if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
493 return NULL;
494
495 return out.pointer;
496}
497EXPORT_SYMBOL_GPL(wmidev_block_query);
498
499/**
500 * wmi_set_block - Write to a WMI block (deprecated)
501 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
502 * @instance: Instance index
503 * @in: Buffer containing new values for the data block
504 *
505 * Write the contents of the input buffer to an ACPI-WMI data block.
506 *
507 * Return: acpi_status signaling success or error.
508 */
509acpi_status wmi_set_block(const char *guid_string, u8 instance, const struct acpi_buffer *in)
510{
511 struct wmi_device *wdev;
512 acpi_status status;
513
514 wdev = wmi_find_device_by_guid(guid_string);
515 if (IS_ERR(wdev))
516 return AE_ERROR;
517
518 status = wmidev_block_set(wdev, instance, in);
519 wmi_device_put(wdev);
520
521 return status;
522}
523EXPORT_SYMBOL_GPL(wmi_set_block);
524
525/**
526 * wmidev_block_set - Write to a WMI block
527 * @wdev: A wmi bus device from a driver
528 * @instance: Instance index
529 * @in: Buffer containing new values for the data block
530 *
531 * Write contents of the input buffer to an ACPI-WMI data block.
532 *
533 * Return: acpi_status signaling success or error.
534 */
535acpi_status wmidev_block_set(struct wmi_device *wdev, u8 instance, const struct acpi_buffer *in)
536{
537 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
538 acpi_handle handle = wblock->acpi_device->handle;
539 struct guid_block *block = &wblock->gblock;
540 char method[WMI_ACPI_METHOD_NAME_SIZE];
541 struct acpi_object_list input;
542 union acpi_object params[2];
543
544 if (!in)
545 return AE_BAD_DATA;
546
547 if (block->instance_count <= instance)
548 return AE_BAD_PARAMETER;
549
550 /* Check GUID is a data block */
551 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
552 return AE_ERROR;
553
554 input.count = 2;
555 input.pointer = params;
556 params[0].type = ACPI_TYPE_INTEGER;
557 params[0].integer.value = instance;
558 params[1].type = get_param_acpi_type(wblock);
559 params[1].buffer.length = in->length;
560 params[1].buffer.pointer = in->pointer;
561
562 get_acpi_method_name(wblock, 'S', method);
563
564 return acpi_evaluate_object(handle, method, &input, NULL);
565}
566EXPORT_SYMBOL_GPL(wmidev_block_set);
567
568/**
569 * wmi_install_notify_handler - Register handler for WMI events (deprecated)
570 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
571 * @handler: Function to handle notifications
572 * @data: Data to be returned to handler when event is fired
573 *
574 * Register a handler for events sent to the ACPI-WMI mapper device.
575 *
576 * Return: acpi_status signaling success or error.
577 */
578acpi_status wmi_install_notify_handler(const char *guid,
579 wmi_notify_handler handler,
580 void *data)
581{
582 struct wmi_block *wblock;
583 struct wmi_device *wdev;
584 acpi_status status;
585
586 wdev = wmi_find_device_by_guid(guid);
587 if (IS_ERR(wdev))
588 return AE_ERROR;
589
590 wblock = container_of(wdev, struct wmi_block, dev);
591
592 down_write(&wblock->notify_lock);
593 if (wblock->handler) {
594 status = AE_ALREADY_ACQUIRED;
595 } else {
596 wblock->handler = handler;
597 wblock->handler_data = data;
598
599 if (ACPI_FAILURE(wmi_method_enable(wblock, true)))
600 dev_warn(&wblock->dev.dev, "Failed to enable device\n");
601
602 status = AE_OK;
603 }
604 up_write(&wblock->notify_lock);
605
606 wmi_device_put(wdev);
607
608 return status;
609}
610EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
611
612/**
613 * wmi_remove_notify_handler - Unregister handler for WMI events (deprecated)
614 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
615 *
616 * Unregister handler for events sent to the ACPI-WMI mapper device.
617 *
618 * Return: acpi_status signaling success or error.
619 */
620acpi_status wmi_remove_notify_handler(const char *guid)
621{
622 struct wmi_block *wblock;
623 struct wmi_device *wdev;
624 acpi_status status;
625
626 wdev = wmi_find_device_by_guid(guid);
627 if (IS_ERR(wdev))
628 return AE_ERROR;
629
630 wblock = container_of(wdev, struct wmi_block, dev);
631
632 down_write(&wblock->notify_lock);
633 if (!wblock->handler) {
634 status = AE_NULL_ENTRY;
635 } else {
636 if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
637 dev_warn(&wblock->dev.dev, "Failed to disable device\n");
638
639 wblock->handler = NULL;
640 wblock->handler_data = NULL;
641
642 status = AE_OK;
643 }
644 up_write(&wblock->notify_lock);
645
646 wmi_device_put(wdev);
647
648 return status;
649}
650EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
651
652/**
653 * wmi_get_event_data - Get WMI data associated with an event (deprecated)
654 *
655 * @event: Event to find
656 * @out: Buffer to hold event data
657 *
658 * Get extra data associated with an WMI event, the caller needs to free @out.
659 *
660 * Return: acpi_status signaling success or error.
661 */
662acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
663{
664 struct wmi_block *wblock;
665 struct wmi_device *wdev;
666 acpi_status status;
667
668 wdev = wmi_find_event_by_notify_id(event);
669 if (IS_ERR(wdev))
670 return AE_NOT_FOUND;
671
672 wblock = container_of(wdev, struct wmi_block, dev);
673 status = get_event_data(wblock, out);
674
675 wmi_device_put(wdev);
676
677 return status;
678}
679EXPORT_SYMBOL_GPL(wmi_get_event_data);
680
681/**
682 * wmi_has_guid - Check if a GUID is available
683 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
684 *
685 * Check if a given GUID is defined by _WDG.
686 *
687 * Return: True if GUID is available, false otherwise.
688 */
689bool wmi_has_guid(const char *guid_string)
690{
691 struct wmi_device *wdev;
692
693 wdev = wmi_find_device_by_guid(guid_string);
694 if (IS_ERR(wdev))
695 return false;
696
697 wmi_device_put(wdev);
698
699 return true;
700}
701EXPORT_SYMBOL_GPL(wmi_has_guid);
702
703/**
704 * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID (deprecated)
705 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
706 *
707 * Find the _UID of ACPI device associated with this WMI GUID.
708 *
709 * Return: The ACPI _UID field value or NULL if the WMI GUID was not found.
710 */
711char *wmi_get_acpi_device_uid(const char *guid_string)
712{
713 struct wmi_block *wblock;
714 struct wmi_device *wdev;
715 char *uid;
716
717 wdev = wmi_find_device_by_guid(guid_string);
718 if (IS_ERR(wdev))
719 return NULL;
720
721 wblock = container_of(wdev, struct wmi_block, dev);
722 uid = acpi_device_uid(wblock->acpi_device);
723
724 wmi_device_put(wdev);
725
726 return uid;
727}
728EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
729
730static inline struct wmi_driver *drv_to_wdrv(struct device_driver *drv)
731{
732 return container_of(drv, struct wmi_driver, driver);
733}
734
735/*
736 * sysfs interface
737 */
738static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
739 char *buf)
740{
741 struct wmi_block *wblock = dev_to_wblock(dev);
742
743 return sysfs_emit(buf, "wmi:%pUL\n", &wblock->gblock.guid);
744}
745static DEVICE_ATTR_RO(modalias);
746
747static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
748 char *buf)
749{
750 struct wmi_block *wblock = dev_to_wblock(dev);
751
752 return sysfs_emit(buf, "%pUL\n", &wblock->gblock.guid);
753}
754static DEVICE_ATTR_RO(guid);
755
756static ssize_t instance_count_show(struct device *dev,
757 struct device_attribute *attr, char *buf)
758{
759 struct wmi_block *wblock = dev_to_wblock(dev);
760
761 return sysfs_emit(buf, "%d\n", (int)wblock->gblock.instance_count);
762}
763static DEVICE_ATTR_RO(instance_count);
764
765static ssize_t expensive_show(struct device *dev,
766 struct device_attribute *attr, char *buf)
767{
768 struct wmi_block *wblock = dev_to_wblock(dev);
769
770 return sysfs_emit(buf, "%d\n",
771 (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
772}
773static DEVICE_ATTR_RO(expensive);
774
775static struct attribute *wmi_attrs[] = {
776 &dev_attr_modalias.attr,
777 &dev_attr_guid.attr,
778 &dev_attr_instance_count.attr,
779 &dev_attr_expensive.attr,
780 NULL
781};
782ATTRIBUTE_GROUPS(wmi);
783
784static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
785 char *buf)
786{
787 struct wmi_block *wblock = dev_to_wblock(dev);
788
789 return sysfs_emit(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
790}
791static DEVICE_ATTR_RO(notify_id);
792
793static struct attribute *wmi_event_attrs[] = {
794 &dev_attr_notify_id.attr,
795 NULL
796};
797ATTRIBUTE_GROUPS(wmi_event);
798
799static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
800 char *buf)
801{
802 struct wmi_block *wblock = dev_to_wblock(dev);
803
804 return sysfs_emit(buf, "%c%c\n", wblock->gblock.object_id[0],
805 wblock->gblock.object_id[1]);
806}
807static DEVICE_ATTR_RO(object_id);
808
809static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
810 char *buf)
811{
812 struct wmi_device *wdev = dev_to_wdev(dev);
813
814 return sysfs_emit(buf, "%d\n", (int)wdev->setable);
815}
816static DEVICE_ATTR_RO(setable);
817
818static struct attribute *wmi_data_attrs[] = {
819 &dev_attr_object_id.attr,
820 &dev_attr_setable.attr,
821 NULL
822};
823ATTRIBUTE_GROUPS(wmi_data);
824
825static struct attribute *wmi_method_attrs[] = {
826 &dev_attr_object_id.attr,
827 NULL
828};
829ATTRIBUTE_GROUPS(wmi_method);
830
831static int wmi_dev_uevent(const struct device *dev, struct kobj_uevent_env *env)
832{
833 const struct wmi_block *wblock = dev_to_wblock(dev);
834
835 if (add_uevent_var(env, "MODALIAS=wmi:%pUL", &wblock->gblock.guid))
836 return -ENOMEM;
837
838 if (add_uevent_var(env, "WMI_GUID=%pUL", &wblock->gblock.guid))
839 return -ENOMEM;
840
841 return 0;
842}
843
844static void wmi_dev_release(struct device *dev)
845{
846 struct wmi_block *wblock = dev_to_wblock(dev);
847
848 kfree(wblock);
849}
850
851static int wmi_dev_match(struct device *dev, struct device_driver *driver)
852{
853 struct wmi_driver *wmi_driver = drv_to_wdrv(driver);
854 struct wmi_block *wblock = dev_to_wblock(dev);
855 const struct wmi_device_id *id = wmi_driver->id_table;
856
857 if (id == NULL)
858 return 0;
859
860 while (*id->guid_string) {
861 if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid))
862 return 1;
863
864 id++;
865 }
866
867 return 0;
868}
869
870static int wmi_dev_probe(struct device *dev)
871{
872 struct wmi_block *wblock = dev_to_wblock(dev);
873 struct wmi_driver *wdriver = drv_to_wdrv(dev->driver);
874 int ret = 0;
875
876 /* Some older WMI drivers will break if instantiated multiple times,
877 * so they are blocked from probing WMI devices with a duplicated GUID.
878 *
879 * New WMI drivers should support being instantiated multiple times.
880 */
881 if (test_bit(WMI_GUID_DUPLICATED, &wblock->flags) && !wdriver->no_singleton) {
882 dev_warn(dev, "Legacy driver %s cannot be instantiated multiple times\n",
883 dev->driver->name);
884
885 return -ENODEV;
886 }
887
888 if (wdriver->notify) {
889 if (test_bit(WMI_NO_EVENT_DATA, &wblock->flags) && !wdriver->no_notify_data)
890 return -ENODEV;
891 }
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 const 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 char method[WMI_ACPI_METHOD_NAME_SIZE];
983 struct acpi_device_info *info;
984 acpi_handle method_handle;
985 acpi_status status;
986 uint count;
987
988 if (wblock->gblock.flags & ACPI_WMI_EVENT) {
989 wblock->dev.dev.type = &wmi_type_event;
990 goto out_init;
991 }
992
993 if (wblock->gblock.flags & ACPI_WMI_METHOD) {
994 get_acpi_method_name(wblock, 'M', method);
995 if (!acpi_has_method(device->handle, method)) {
996 dev_warn(wmi_bus_dev,
997 FW_BUG "%s method block execution control method not found\n",
998 method);
999
1000 return -ENXIO;
1001 }
1002
1003 wblock->dev.dev.type = &wmi_type_method;
1004 goto out_init;
1005 }
1006
1007 /*
1008 * Data Block Query Control Method (WQxx by convention) is
1009 * required per the WMI documentation. If it is not present,
1010 * we ignore this data block.
1011 */
1012 get_acpi_method_name(wblock, 'Q', method);
1013 status = acpi_get_handle(device->handle, method, &method_handle);
1014 if (ACPI_FAILURE(status)) {
1015 dev_warn(wmi_bus_dev,
1016 FW_BUG "%s data block query control method not found\n",
1017 method);
1018
1019 return -ENXIO;
1020 }
1021
1022 status = acpi_get_object_info(method_handle, &info);
1023 if (ACPI_FAILURE(status))
1024 return -EIO;
1025
1026 wblock->dev.dev.type = &wmi_type_data;
1027
1028 /*
1029 * The Microsoft documentation specifically states:
1030 *
1031 * Data blocks registered with only a single instance
1032 * can ignore the parameter.
1033 *
1034 * ACPICA will get mad at us if we call the method with the wrong number
1035 * of arguments, so check what our method expects. (On some Dell
1036 * laptops, WQxx may not be a method at all.)
1037 */
1038 if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1039 set_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags);
1040
1041 kfree(info);
1042
1043 get_acpi_method_name(wblock, 'S', method);
1044 if (acpi_has_method(device->handle, method))
1045 wblock->dev.setable = true;
1046
1047 out_init:
1048 init_rwsem(&wblock->notify_lock);
1049 wblock->driver_ready = false;
1050 wblock->dev.dev.bus = &wmi_bus_type;
1051 wblock->dev.dev.parent = wmi_bus_dev;
1052
1053 count = guid_count(&wblock->gblock.guid);
1054 if (count) {
1055 dev_set_name(&wblock->dev.dev, "%pUL-%d", &wblock->gblock.guid, count);
1056 set_bit(WMI_GUID_DUPLICATED, &wblock->flags);
1057 } else {
1058 dev_set_name(&wblock->dev.dev, "%pUL", &wblock->gblock.guid);
1059 }
1060
1061 device_initialize(&wblock->dev.dev);
1062
1063 return 0;
1064}
1065
1066static int wmi_add_device(struct platform_device *pdev, struct wmi_device *wdev)
1067{
1068 struct device_link *link;
1069
1070 /*
1071 * Many aggregate WMI drivers do not use -EPROBE_DEFER when they
1072 * are unable to find a WMI device during probe, instead they require
1073 * all WMI devices associated with an platform device to become available
1074 * at once. This device link thus prevents WMI drivers from probing until
1075 * the associated platform device has finished probing (and has registered
1076 * all discovered WMI devices).
1077 */
1078
1079 link = device_link_add(&wdev->dev, &pdev->dev, DL_FLAG_AUTOREMOVE_SUPPLIER);
1080 if (!link)
1081 return -EINVAL;
1082
1083 return device_add(&wdev->dev);
1084}
1085
1086/*
1087 * Parse the _WDG method for the GUID data blocks
1088 */
1089static int parse_wdg(struct device *wmi_bus_dev, struct platform_device *pdev)
1090{
1091 struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
1092 struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1093 const struct guid_block *gblock;
1094 bool event_data_available;
1095 struct wmi_block *wblock;
1096 union acpi_object *obj;
1097 acpi_status status;
1098 u32 i, total;
1099 int retval;
1100
1101 status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1102 if (ACPI_FAILURE(status))
1103 return -ENXIO;
1104
1105 obj = out.pointer;
1106 if (!obj)
1107 return -ENXIO;
1108
1109 if (obj->type != ACPI_TYPE_BUFFER) {
1110 kfree(obj);
1111 return -ENXIO;
1112 }
1113
1114 event_data_available = acpi_has_method(device->handle, "_WED");
1115 gblock = (const struct guid_block *)obj->buffer.pointer;
1116 total = obj->buffer.length / sizeof(struct guid_block);
1117
1118 for (i = 0; i < total; i++) {
1119 if (!gblock[i].instance_count) {
1120 dev_info(wmi_bus_dev, FW_INFO "%pUL has zero instances\n", &gblock[i].guid);
1121 continue;
1122 }
1123
1124 wblock = kzalloc(sizeof(*wblock), GFP_KERNEL);
1125 if (!wblock)
1126 continue;
1127
1128 wblock->acpi_device = device;
1129 wblock->gblock = gblock[i];
1130 if (gblock[i].flags & ACPI_WMI_EVENT && !event_data_available)
1131 set_bit(WMI_NO_EVENT_DATA, &wblock->flags);
1132
1133 retval = wmi_create_device(wmi_bus_dev, wblock, device);
1134 if (retval) {
1135 kfree(wblock);
1136 continue;
1137 }
1138
1139 list_add_tail(&wblock->list, &wmi_block_list);
1140
1141 retval = wmi_add_device(pdev, &wblock->dev);
1142 if (retval) {
1143 dev_err(wmi_bus_dev, "failed to register %pUL\n",
1144 &wblock->gblock.guid);
1145
1146 list_del(&wblock->list);
1147 put_device(&wblock->dev.dev);
1148 }
1149 }
1150
1151 kfree(obj);
1152
1153 return 0;
1154}
1155
1156/*
1157 * WMI can have EmbeddedControl access regions. In which case, we just want to
1158 * hand these off to the EC driver.
1159 */
1160static acpi_status
1161acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1162 u32 bits, u64 *value,
1163 void *handler_context, void *region_context)
1164{
1165 int result = 0;
1166 u8 temp = 0;
1167
1168 if ((address > 0xFF) || !value)
1169 return AE_BAD_PARAMETER;
1170
1171 if (function != ACPI_READ && function != ACPI_WRITE)
1172 return AE_BAD_PARAMETER;
1173
1174 if (bits != 8)
1175 return AE_BAD_PARAMETER;
1176
1177 if (function == ACPI_READ) {
1178 result = ec_read(address, &temp);
1179 *value = temp;
1180 } else {
1181 temp = 0xff & *value;
1182 result = ec_write(address, temp);
1183 }
1184
1185 switch (result) {
1186 case -EINVAL:
1187 return AE_BAD_PARAMETER;
1188 case -ENODEV:
1189 return AE_NOT_FOUND;
1190 case -ETIME:
1191 return AE_TIME;
1192 default:
1193 return AE_OK;
1194 }
1195}
1196
1197static int wmi_get_notify_data(struct wmi_block *wblock, union acpi_object **obj)
1198{
1199 struct acpi_buffer data = { ACPI_ALLOCATE_BUFFER, NULL };
1200 acpi_status status;
1201
1202 if (test_bit(WMI_NO_EVENT_DATA, &wblock->flags)) {
1203 *obj = NULL;
1204 return 0;
1205 }
1206
1207 status = get_event_data(wblock, &data);
1208 if (ACPI_FAILURE(status)) {
1209 dev_warn(&wblock->dev.dev, "Failed to get event data\n");
1210 return -EIO;
1211 }
1212
1213 *obj = data.pointer;
1214
1215 return 0;
1216}
1217
1218static void wmi_notify_driver(struct wmi_block *wblock, union acpi_object *obj)
1219{
1220 struct wmi_driver *driver = drv_to_wdrv(wblock->dev.dev.driver);
1221
1222 if (!obj && !driver->no_notify_data) {
1223 dev_warn(&wblock->dev.dev, "Event contains no event data\n");
1224 return;
1225 }
1226
1227 if (driver->notify)
1228 driver->notify(&wblock->dev, obj);
1229}
1230
1231static int wmi_notify_device(struct device *dev, void *data)
1232{
1233 struct wmi_block *wblock = dev_to_wblock(dev);
1234 union acpi_object *obj;
1235 u32 *event = data;
1236 int ret;
1237
1238 if (!(wblock->gblock.flags & ACPI_WMI_EVENT && wblock->gblock.notify_id == *event))
1239 return 0;
1240
1241 down_read(&wblock->notify_lock);
1242 /* The WMI driver notify handler conflicts with the legacy WMI handler.
1243 * Because of this the WMI driver notify handler takes precedence.
1244 */
1245 if (wblock->dev.dev.driver && wblock->driver_ready) {
1246 ret = wmi_get_notify_data(wblock, &obj);
1247 if (ret >= 0) {
1248 wmi_notify_driver(wblock, obj);
1249 kfree(obj);
1250 }
1251 } else {
1252 if (wblock->handler) {
1253 wblock->handler(*event, wblock->handler_data);
1254 } else {
1255 /* The ACPI WMI specification says that _WED should be
1256 * evaluated every time an notification is received, even
1257 * if no consumers are present.
1258 *
1259 * Some firmware implementations actually depend on this
1260 * by using a queue for events which will fill up if the
1261 * WMI driver core stops evaluating _WED due to missing
1262 * WMI event consumers.
1263 *
1264 * Because of this we need this seemingly useless call to
1265 * wmi_get_notify_data() which in turn evaluates _WED.
1266 */
1267 ret = wmi_get_notify_data(wblock, &obj);
1268 if (ret >= 0)
1269 kfree(obj);
1270 }
1271
1272 }
1273 up_read(&wblock->notify_lock);
1274
1275 acpi_bus_generate_netlink_event("wmi", acpi_dev_name(wblock->acpi_device), *event, 0);
1276
1277 return -EBUSY;
1278}
1279
1280static void acpi_wmi_notify_handler(acpi_handle handle, u32 event, void *context)
1281{
1282 struct device *wmi_bus_dev = context;
1283
1284 device_for_each_child(wmi_bus_dev, &event, wmi_notify_device);
1285}
1286
1287static int wmi_remove_device(struct device *dev, void *data)
1288{
1289 struct wmi_block *wblock = dev_to_wblock(dev);
1290
1291 list_del(&wblock->list);
1292 device_unregister(dev);
1293
1294 return 0;
1295}
1296
1297static void acpi_wmi_remove(struct platform_device *device)
1298{
1299 struct device *wmi_bus_device = dev_get_drvdata(&device->dev);
1300
1301 device_for_each_child_reverse(wmi_bus_device, NULL, wmi_remove_device);
1302}
1303
1304static void acpi_wmi_remove_notify_handler(void *data)
1305{
1306 struct acpi_device *acpi_device = data;
1307
1308 acpi_remove_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY, acpi_wmi_notify_handler);
1309}
1310
1311static void acpi_wmi_remove_address_space_handler(void *data)
1312{
1313 struct acpi_device *acpi_device = data;
1314
1315 acpi_remove_address_space_handler(acpi_device->handle, ACPI_ADR_SPACE_EC,
1316 &acpi_wmi_ec_space_handler);
1317}
1318
1319static void acpi_wmi_remove_bus_device(void *data)
1320{
1321 struct device *wmi_bus_dev = data;
1322
1323 device_unregister(wmi_bus_dev);
1324}
1325
1326static int acpi_wmi_probe(struct platform_device *device)
1327{
1328 struct acpi_device *acpi_device;
1329 struct device *wmi_bus_dev;
1330 acpi_status status;
1331 int error;
1332
1333 acpi_device = ACPI_COMPANION(&device->dev);
1334 if (!acpi_device) {
1335 dev_err(&device->dev, "ACPI companion is missing\n");
1336 return -ENODEV;
1337 }
1338
1339 wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0), NULL, "wmi_bus-%s",
1340 dev_name(&device->dev));
1341 if (IS_ERR(wmi_bus_dev))
1342 return PTR_ERR(wmi_bus_dev);
1343
1344 error = devm_add_action_or_reset(&device->dev, acpi_wmi_remove_bus_device, wmi_bus_dev);
1345 if (error < 0)
1346 return error;
1347
1348 dev_set_drvdata(&device->dev, wmi_bus_dev);
1349
1350 status = acpi_install_address_space_handler(acpi_device->handle,
1351 ACPI_ADR_SPACE_EC,
1352 &acpi_wmi_ec_space_handler,
1353 NULL, NULL);
1354 if (ACPI_FAILURE(status)) {
1355 dev_err(&device->dev, "Error installing EC region handler\n");
1356 return -ENODEV;
1357 }
1358 error = devm_add_action_or_reset(&device->dev, acpi_wmi_remove_address_space_handler,
1359 acpi_device);
1360 if (error < 0)
1361 return error;
1362
1363 status = acpi_install_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY,
1364 acpi_wmi_notify_handler, wmi_bus_dev);
1365 if (ACPI_FAILURE(status)) {
1366 dev_err(&device->dev, "Error installing notify handler\n");
1367 return -ENODEV;
1368 }
1369 error = devm_add_action_or_reset(&device->dev, acpi_wmi_remove_notify_handler,
1370 acpi_device);
1371 if (error < 0)
1372 return error;
1373
1374 error = parse_wdg(wmi_bus_dev, device);
1375 if (error) {
1376 dev_err(&device->dev, "Failed to parse _WDG method\n");
1377 return error;
1378 }
1379
1380 return 0;
1381}
1382
1383int __must_check __wmi_driver_register(struct wmi_driver *driver,
1384 struct module *owner)
1385{
1386 driver->driver.owner = owner;
1387 driver->driver.bus = &wmi_bus_type;
1388
1389 return driver_register(&driver->driver);
1390}
1391EXPORT_SYMBOL(__wmi_driver_register);
1392
1393/**
1394 * wmi_driver_unregister() - Unregister a WMI driver
1395 * @driver: WMI driver to unregister
1396 *
1397 * Unregisters a WMI driver from the WMI bus.
1398 */
1399void wmi_driver_unregister(struct wmi_driver *driver)
1400{
1401 driver_unregister(&driver->driver);
1402}
1403EXPORT_SYMBOL(wmi_driver_unregister);
1404
1405static struct platform_driver acpi_wmi_driver = {
1406 .driver = {
1407 .name = "acpi-wmi",
1408 .acpi_match_table = wmi_device_ids,
1409 },
1410 .probe = acpi_wmi_probe,
1411 .remove_new = acpi_wmi_remove,
1412};
1413
1414static int __init acpi_wmi_init(void)
1415{
1416 int error;
1417
1418 if (acpi_disabled)
1419 return -ENODEV;
1420
1421 error = class_register(&wmi_bus_class);
1422 if (error)
1423 return error;
1424
1425 error = bus_register(&wmi_bus_type);
1426 if (error)
1427 goto err_unreg_class;
1428
1429 error = platform_driver_register(&acpi_wmi_driver);
1430 if (error) {
1431 pr_err("Error loading mapper\n");
1432 goto err_unreg_bus;
1433 }
1434
1435 return 0;
1436
1437err_unreg_bus:
1438 bus_unregister(&wmi_bus_type);
1439
1440err_unreg_class:
1441 class_unregister(&wmi_bus_class);
1442
1443 return error;
1444}
1445
1446static void __exit acpi_wmi_exit(void)
1447{
1448 platform_driver_unregister(&acpi_wmi_driver);
1449 bus_unregister(&wmi_bus_type);
1450 class_unregister(&wmi_bus_class);
1451}
1452
1453subsys_initcall_sync(acpi_wmi_init);
1454module_exit(acpi_wmi_exit);