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treewide: remove redundant IS_ERR() before error code check
[linux/fpc-iii.git] / drivers / platform / x86 / wmi.c
blobdc2e966a5c25425b4c4fb11e1cc7ce49bcfce6e3
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/device.h>
21 #include <linux/init.h>
22 #include <linux/kernel.h>
23 #include <linux/list.h>
24 #include <linux/miscdevice.h>
25 #include <linux/module.h>
26 #include <linux/platform_device.h>
27 #include <linux/slab.h>
28 #include <linux/types.h>
29 #include <linux/uaccess.h>
30 #include <linux/uuid.h>
31 #include <linux/wmi.h>
32 #include <uapi/linux/wmi.h>
33
34 ACPI_MODULE_NAME("wmi");
35 MODULE_AUTHOR("Carlos Corbacho");
36 MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
37 MODULE_LICENSE("GPL");
38
39 static LIST_HEAD(wmi_block_list);
40
41 struct guid_block {
42 char guid[16];
43 union {
44 char object_id[2];
45 struct {
46 unsigned char notify_id;
47 unsigned char reserved;
48 };
49 };
50 u8 instance_count;
51 u8 flags;
52 };
53
54 struct wmi_block {
55 struct wmi_device dev;
56 struct list_head list;
57 struct guid_block gblock;
58 struct miscdevice char_dev;
59 struct mutex char_mutex;
60 struct acpi_device *acpi_device;
61 wmi_notify_handler handler;
62 void *handler_data;
63 u64 req_buf_size;
64
65 bool read_takes_no_args;
66 };
67
68
69 /*
70 * If the GUID data block is marked as expensive, we must enable and
71 * explicitily disable data collection.
72 */
73 #define ACPI_WMI_EXPENSIVE 0x1
74 #define ACPI_WMI_METHOD 0x2 /* GUID is a method */
75 #define ACPI_WMI_STRING 0x4 /* GUID takes & returns a string */
76 #define ACPI_WMI_EVENT 0x8 /* GUID is an event */
77
78 static bool debug_event;
79 module_param(debug_event, bool, 0444);
80 MODULE_PARM_DESC(debug_event,
81 "Log WMI Events [0/1]");
82
83 static bool debug_dump_wdg;
84 module_param(debug_dump_wdg, bool, 0444);
85 MODULE_PARM_DESC(debug_dump_wdg,
86 "Dump available WMI interfaces [0/1]");
87
88 static int acpi_wmi_remove(struct platform_device *device);
89 static int acpi_wmi_probe(struct platform_device *device);
90
91 static const struct acpi_device_id wmi_device_ids[] = {
92 {"PNP0C14", 0},
93 {"pnp0c14", 0},
94 {"", 0},
95 };
96 MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
97
98 static struct platform_driver acpi_wmi_driver = {
99 .driver = {
100 .name = "acpi-wmi",
101 .acpi_match_table = wmi_device_ids,
102 },
103 .probe = acpi_wmi_probe,
104 .remove = acpi_wmi_remove,
105 };
106
107 /*
108 * GUID parsing functions
109 */
110
111 static bool find_guid(const char *guid_string, struct wmi_block **out)
112 {
113 uuid_le guid_input;
114 struct wmi_block *wblock;
115 struct guid_block *block;
116
117 if (uuid_le_to_bin(guid_string, &guid_input))
118 return false;
119
120 list_for_each_entry(wblock, &wmi_block_list, list) {
121 block = &wblock->gblock;
122
123 if (memcmp(block->guid, &guid_input, 16) == 0) {
124 if (out)
125 *out = wblock;
126 return true;
127 }
128 }
129 return false;
130 }
131
132 static const void *find_guid_context(struct wmi_block *wblock,
133 struct wmi_driver *wdriver)
134 {
135 const struct wmi_device_id *id;
136 uuid_le guid_input;
137
138 if (wblock == NULL || wdriver == NULL)
139 return NULL;
140 if (wdriver->id_table == NULL)
141 return NULL;
142
143 id = wdriver->id_table;
144 while (*id->guid_string) {
145 if (uuid_le_to_bin(id->guid_string, &guid_input))
146 continue;
147 if (!memcmp(wblock->gblock.guid, &guid_input, 16))
148 return id->context;
149 id++;
150 }
151 return NULL;
152 }
153
154 static int get_subobj_info(acpi_handle handle, const char *pathname,
155 struct acpi_device_info **info)
156 {
157 struct acpi_device_info *dummy_info, **info_ptr;
158 acpi_handle subobj_handle;
159 acpi_status status;
160
161 status = acpi_get_handle(handle, (char *)pathname, &subobj_handle);
162 if (status == AE_NOT_FOUND)
163 return -ENOENT;
164 else if (ACPI_FAILURE(status))
165 return -EIO;
166
167 info_ptr = info ? info : &dummy_info;
168 status = acpi_get_object_info(subobj_handle, info_ptr);
169 if (ACPI_FAILURE(status))
170 return -EIO;
171
172 if (!info)
173 kfree(dummy_info);
174
175 return 0;
176 }
177
178 static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable)
179 {
180 struct guid_block *block = NULL;
181 char method[5];
182 acpi_status status;
183 acpi_handle handle;
184
185 block = &wblock->gblock;
186 handle = wblock->acpi_device->handle;
187
188 snprintf(method, 5, "WE%02X", block->notify_id);
189 status = acpi_execute_simple_method(handle, method, enable);
190
191 if (status != AE_OK && status != AE_NOT_FOUND)
192 return status;
193 else
194 return AE_OK;
195 }
196
197 /*
198 * Exported WMI functions
199 */
200
201 /**
202 * set_required_buffer_size - Sets the buffer size needed for performing IOCTL
203 * @wdev: A wmi bus device from a driver
204 * @instance: Instance index
205 *
206 * Allocates memory needed for buffer, stores the buffer size in that memory
207 */
208 int set_required_buffer_size(struct wmi_device *wdev, u64 length)
209 {
210 struct wmi_block *wblock;
211
212 wblock = container_of(wdev, struct wmi_block, dev);
213 wblock->req_buf_size = length;
214
215 return 0;
216 }
217 EXPORT_SYMBOL_GPL(set_required_buffer_size);
218
219 /**
220 * wmi_evaluate_method - Evaluate a WMI method
221 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
222 * @instance: Instance index
223 * @method_id: Method ID to call
224 * &in: Buffer containing input for the method call
225 * &out: Empty buffer to return the method results
226 *
227 * Call an ACPI-WMI method
228 */
229 acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
230 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
231 {
232 struct wmi_block *wblock = NULL;
233
234 if (!find_guid(guid_string, &wblock))
235 return AE_ERROR;
236 return wmidev_evaluate_method(&wblock->dev, instance, method_id,
237 in, out);
238 }
239 EXPORT_SYMBOL_GPL(wmi_evaluate_method);
240
241 /**
242 * wmidev_evaluate_method - Evaluate a WMI method
243 * @wdev: A wmi bus device from a driver
244 * @instance: Instance index
245 * @method_id: Method ID to call
246 * &in: Buffer containing input for the method call
247 * &out: Empty buffer to return the method results
248 *
249 * Call an ACPI-WMI method
250 */
251 acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance,
252 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
253 {
254 struct guid_block *block = NULL;
255 struct wmi_block *wblock = NULL;
256 acpi_handle handle;
257 acpi_status status;
258 struct acpi_object_list input;
259 union acpi_object params[3];
260 char method[5] = "WM";
261
262 wblock = container_of(wdev, struct wmi_block, dev);
263 block = &wblock->gblock;
264 handle = wblock->acpi_device->handle;
265
266 if (!(block->flags & ACPI_WMI_METHOD))
267 return AE_BAD_DATA;
268
269 if (block->instance_count <= instance)
270 return AE_BAD_PARAMETER;
271
272 input.count = 2;
273 input.pointer = params;
274 params[0].type = ACPI_TYPE_INTEGER;
275 params[0].integer.value = instance;
276 params[1].type = ACPI_TYPE_INTEGER;
277 params[1].integer.value = method_id;
278
279 if (in) {
280 input.count = 3;
281
282 if (block->flags & ACPI_WMI_STRING) {
283 params[2].type = ACPI_TYPE_STRING;
284 } else {
285 params[2].type = ACPI_TYPE_BUFFER;
286 }
287 params[2].buffer.length = in->length;
288 params[2].buffer.pointer = in->pointer;
289 }
290
291 strncat(method, block->object_id, 2);
292
293 status = acpi_evaluate_object(handle, method, &input, out);
294
295 return status;
296 }
297 EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
298
299 static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
300 struct acpi_buffer *out)
301 {
302 struct guid_block *block = NULL;
303 acpi_handle handle;
304 acpi_status status, wc_status = AE_ERROR;
305 struct acpi_object_list input;
306 union acpi_object wq_params[1];
307 char method[5];
308 char wc_method[5] = "WC";
309
310 if (!out)
311 return AE_BAD_PARAMETER;
312
313 block = &wblock->gblock;
314 handle = wblock->acpi_device->handle;
315
316 if (block->instance_count <= instance)
317 return AE_BAD_PARAMETER;
318
319 /* Check GUID is a data block */
320 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
321 return AE_ERROR;
322
323 input.count = 1;
324 input.pointer = wq_params;
325 wq_params[0].type = ACPI_TYPE_INTEGER;
326 wq_params[0].integer.value = instance;
327
328 if (instance == 0 && wblock->read_takes_no_args)
329 input.count = 0;
330
331 /*
332 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
333 * enable collection.
334 */
335 if (block->flags & ACPI_WMI_EXPENSIVE) {
336 strncat(wc_method, block->object_id, 2);
337
338 /*
339 * Some GUIDs break the specification by declaring themselves
340 * expensive, but have no corresponding WCxx method. So we
341 * should not fail if this happens.
342 */
343 wc_status = acpi_execute_simple_method(handle, wc_method, 1);
344 }
345
346 strcpy(method, "WQ");
347 strncat(method, block->object_id, 2);
348
349 status = acpi_evaluate_object(handle, method, &input, out);
350
351 /*
352 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
353 * the WQxx method failed - we should disable collection anyway.
354 */
355 if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
356 status = acpi_execute_simple_method(handle, wc_method, 0);
357 }
358
359 return status;
360 }
361
362 /**
363 * wmi_query_block - Return contents of a WMI block (deprecated)
364 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
365 * @instance: Instance index
366 * &out: Empty buffer to return the contents of the data block to
367 *
368 * Return the contents of an ACPI-WMI data block to a buffer
369 */
370 acpi_status wmi_query_block(const char *guid_string, u8 instance,
371 struct acpi_buffer *out)
372 {
373 struct wmi_block *wblock;
374
375 if (!guid_string)
376 return AE_BAD_PARAMETER;
377
378 if (!find_guid(guid_string, &wblock))
379 return AE_ERROR;
380
381 return __query_block(wblock, instance, out);
382 }
383 EXPORT_SYMBOL_GPL(wmi_query_block);
384
385 union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
386 {
387 struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
388 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
389
390 if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
391 return NULL;
392
393 return (union acpi_object *)out.pointer;
394 }
395 EXPORT_SYMBOL_GPL(wmidev_block_query);
396
397 /**
398 * wmi_set_block - Write to a WMI block
399 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
400 * @instance: Instance index
401 * &in: Buffer containing new values for the data block
402 *
403 * Write the contents of the input buffer to an ACPI-WMI data block
404 */
405 acpi_status wmi_set_block(const char *guid_string, u8 instance,
406 const struct acpi_buffer *in)
407 {
408 struct guid_block *block = NULL;
409 struct wmi_block *wblock = NULL;
410 acpi_handle handle;
411 struct acpi_object_list input;
412 union acpi_object params[2];
413 char method[5] = "WS";
414
415 if (!guid_string || !in)
416 return AE_BAD_DATA;
417
418 if (!find_guid(guid_string, &wblock))
419 return AE_ERROR;
420
421 block = &wblock->gblock;
422 handle = wblock->acpi_device->handle;
423
424 if (block->instance_count <= instance)
425 return AE_BAD_PARAMETER;
426
427 /* Check GUID is a data block */
428 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
429 return AE_ERROR;
430
431 input.count = 2;
432 input.pointer = params;
433 params[0].type = ACPI_TYPE_INTEGER;
434 params[0].integer.value = instance;
435
436 if (block->flags & ACPI_WMI_STRING) {
437 params[1].type = ACPI_TYPE_STRING;
438 } else {
439 params[1].type = ACPI_TYPE_BUFFER;
440 }
441 params[1].buffer.length = in->length;
442 params[1].buffer.pointer = in->pointer;
443
444 strncat(method, block->object_id, 2);
445
446 return acpi_evaluate_object(handle, method, &input, NULL);
447 }
448 EXPORT_SYMBOL_GPL(wmi_set_block);
449
450 static void wmi_dump_wdg(const struct guid_block *g)
451 {
452 pr_info("%pUL:\n", g->guid);
453 if (g->flags & ACPI_WMI_EVENT)
454 pr_info("\tnotify_id: 0x%02X\n", g->notify_id);
455 else
456 pr_info("\tobject_id: %2pE\n", g->object_id);
457 pr_info("\tinstance_count: %d\n", g->instance_count);
458 pr_info("\tflags: %#x", g->flags);
459 if (g->flags) {
460 if (g->flags & ACPI_WMI_EXPENSIVE)
461 pr_cont(" ACPI_WMI_EXPENSIVE");
462 if (g->flags & ACPI_WMI_METHOD)
463 pr_cont(" ACPI_WMI_METHOD");
464 if (g->flags & ACPI_WMI_STRING)
465 pr_cont(" ACPI_WMI_STRING");
466 if (g->flags & ACPI_WMI_EVENT)
467 pr_cont(" ACPI_WMI_EVENT");
468 }
469 pr_cont("\n");
470
471 }
472
473 static void wmi_notify_debug(u32 value, void *context)
474 {
475 struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
476 union acpi_object *obj;
477 acpi_status status;
478
479 status = wmi_get_event_data(value, &response);
480 if (status != AE_OK) {
481 pr_info("bad event status 0x%x\n", status);
482 return;
483 }
484
485 obj = (union acpi_object *)response.pointer;
486
487 if (!obj)
488 return;
489
490 pr_info("DEBUG Event ");
491 switch(obj->type) {
492 case ACPI_TYPE_BUFFER:
493 pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
494 break;
495 case ACPI_TYPE_STRING:
496 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
497 break;
498 case ACPI_TYPE_INTEGER:
499 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
500 break;
501 case ACPI_TYPE_PACKAGE:
502 pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
503 break;
504 default:
505 pr_cont("object type 0x%X\n", obj->type);
506 }
507 kfree(obj);
508 }
509
510 /**
511 * wmi_install_notify_handler - Register handler for WMI events
512 * @handler: Function to handle notifications
513 * @data: Data to be returned to handler when event is fired
514 *
515 * Register a handler for events sent to the ACPI-WMI mapper device.
516 */
517 acpi_status wmi_install_notify_handler(const char *guid,
518 wmi_notify_handler handler, void *data)
519 {
520 struct wmi_block *block;
521 acpi_status status = AE_NOT_EXIST;
522 uuid_le guid_input;
523
524 if (!guid || !handler)
525 return AE_BAD_PARAMETER;
526
527 if (uuid_le_to_bin(guid, &guid_input))
528 return AE_BAD_PARAMETER;
529
530 list_for_each_entry(block, &wmi_block_list, list) {
531 acpi_status wmi_status;
532
533 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
534 if (block->handler &&
535 block->handler != wmi_notify_debug)
536 return AE_ALREADY_ACQUIRED;
537
538 block->handler = handler;
539 block->handler_data = data;
540
541 wmi_status = wmi_method_enable(block, 1);
542 if ((wmi_status != AE_OK) ||
543 ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
544 status = wmi_status;
545 }
546 }
547
548 return status;
549 }
550 EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
551
552 /**
553 * wmi_uninstall_notify_handler - Unregister handler for WMI events
554 *
555 * Unregister handler for events sent to the ACPI-WMI mapper device.
556 */
557 acpi_status wmi_remove_notify_handler(const char *guid)
558 {
559 struct wmi_block *block;
560 acpi_status status = AE_NOT_EXIST;
561 uuid_le guid_input;
562
563 if (!guid)
564 return AE_BAD_PARAMETER;
565
566 if (uuid_le_to_bin(guid, &guid_input))
567 return AE_BAD_PARAMETER;
568
569 list_for_each_entry(block, &wmi_block_list, list) {
570 acpi_status wmi_status;
571
572 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
573 if (!block->handler ||
574 block->handler == wmi_notify_debug)
575 return AE_NULL_ENTRY;
576
577 if (debug_event) {
578 block->handler = wmi_notify_debug;
579 status = AE_OK;
580 } else {
581 wmi_status = wmi_method_enable(block, 0);
582 block->handler = NULL;
583 block->handler_data = NULL;
584 if ((wmi_status != AE_OK) ||
585 ((wmi_status == AE_OK) &&
586 (status == AE_NOT_EXIST)))
587 status = wmi_status;
588 }
589 }
590 }
591
592 return status;
593 }
594 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
595
596 /**
597 * wmi_get_event_data - Get WMI data associated with an event
598 *
599 * @event: Event to find
600 * @out: Buffer to hold event data. out->pointer should be freed with kfree()
601 *
602 * Returns extra data associated with an event in WMI.
603 */
604 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
605 {
606 struct acpi_object_list input;
607 union acpi_object params[1];
608 struct guid_block *gblock;
609 struct wmi_block *wblock;
610
611 input.count = 1;
612 input.pointer = params;
613 params[0].type = ACPI_TYPE_INTEGER;
614 params[0].integer.value = event;
615
616 list_for_each_entry(wblock, &wmi_block_list, list) {
617 gblock = &wblock->gblock;
618
619 if ((gblock->flags & ACPI_WMI_EVENT) &&
620 (gblock->notify_id == event))
621 return acpi_evaluate_object(wblock->acpi_device->handle,
622 "_WED", &input, out);
623 }
624
625 return AE_NOT_FOUND;
626 }
627 EXPORT_SYMBOL_GPL(wmi_get_event_data);
628
629 /**
630 * wmi_has_guid - Check if a GUID is available
631 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
632 *
633 * Check if a given GUID is defined by _WDG
634 */
635 bool wmi_has_guid(const char *guid_string)
636 {
637 return find_guid(guid_string, NULL);
638 }
639 EXPORT_SYMBOL_GPL(wmi_has_guid);
640
641 /**
642 * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID
643 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
644 *
645 * Find the _UID of ACPI device associated with this WMI GUID.
646 *
647 * Return: The ACPI _UID field value or NULL if the WMI GUID was not found
648 */
649 char *wmi_get_acpi_device_uid(const char *guid_string)
650 {
651 struct wmi_block *wblock = NULL;
652
653 if (!find_guid(guid_string, &wblock))
654 return NULL;
655
656 return acpi_device_uid(wblock->acpi_device);
657 }
658 EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
659
660 static struct wmi_block *dev_to_wblock(struct device *dev)
661 {
662 return container_of(dev, struct wmi_block, dev.dev);
663 }
664
665 static struct wmi_device *dev_to_wdev(struct device *dev)
666 {
667 return container_of(dev, struct wmi_device, dev);
668 }
669
670 /*
671 * sysfs interface
672 */
673 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
674 char *buf)
675 {
676 struct wmi_block *wblock = dev_to_wblock(dev);
677
678 return sprintf(buf, "wmi:%pUL\n", wblock->gblock.guid);
679 }
680 static DEVICE_ATTR_RO(modalias);
681
682 static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
683 char *buf)
684 {
685 struct wmi_block *wblock = dev_to_wblock(dev);
686
687 return sprintf(buf, "%pUL\n", wblock->gblock.guid);
688 }
689 static DEVICE_ATTR_RO(guid);
690
691 static ssize_t instance_count_show(struct device *dev,
692 struct device_attribute *attr, char *buf)
693 {
694 struct wmi_block *wblock = dev_to_wblock(dev);
695
696 return sprintf(buf, "%d\n", (int)wblock->gblock.instance_count);
697 }
698 static DEVICE_ATTR_RO(instance_count);
699
700 static ssize_t expensive_show(struct device *dev,
701 struct device_attribute *attr, char *buf)
702 {
703 struct wmi_block *wblock = dev_to_wblock(dev);
704
705 return sprintf(buf, "%d\n",
706 (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
707 }
708 static DEVICE_ATTR_RO(expensive);
709
710 static struct attribute *wmi_attrs[] = {
711 &dev_attr_modalias.attr,
712 &dev_attr_guid.attr,
713 &dev_attr_instance_count.attr,
714 &dev_attr_expensive.attr,
715 NULL,
716 };
717 ATTRIBUTE_GROUPS(wmi);
718
719 static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
720 char *buf)
721 {
722 struct wmi_block *wblock = dev_to_wblock(dev);
723
724 return sprintf(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
725 }
726 static DEVICE_ATTR_RO(notify_id);
727
728 static struct attribute *wmi_event_attrs[] = {
729 &dev_attr_notify_id.attr,
730 NULL,
731 };
732 ATTRIBUTE_GROUPS(wmi_event);
733
734 static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
735 char *buf)
736 {
737 struct wmi_block *wblock = dev_to_wblock(dev);
738
739 return sprintf(buf, "%c%c\n", wblock->gblock.object_id[0],
740 wblock->gblock.object_id[1]);
741 }
742 static DEVICE_ATTR_RO(object_id);
743
744 static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
745 char *buf)
746 {
747 struct wmi_device *wdev = dev_to_wdev(dev);
748
749 return sprintf(buf, "%d\n", (int)wdev->setable);
750 }
751 static DEVICE_ATTR_RO(setable);
752
753 static struct attribute *wmi_data_attrs[] = {
754 &dev_attr_object_id.attr,
755 &dev_attr_setable.attr,
756 NULL,
757 };
758 ATTRIBUTE_GROUPS(wmi_data);
759
760 static struct attribute *wmi_method_attrs[] = {
761 &dev_attr_object_id.attr,
762 NULL,
763 };
764 ATTRIBUTE_GROUPS(wmi_method);
765
766 static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
767 {
768 struct wmi_block *wblock = dev_to_wblock(dev);
769
770 if (add_uevent_var(env, "MODALIAS=wmi:%pUL", wblock->gblock.guid))
771 return -ENOMEM;
772
773 if (add_uevent_var(env, "WMI_GUID=%pUL", wblock->gblock.guid))
774 return -ENOMEM;
775
776 return 0;
777 }
778
779 static void wmi_dev_release(struct device *dev)
780 {
781 struct wmi_block *wblock = dev_to_wblock(dev);
782
783 kfree(wblock);
784 }
785
786 static int wmi_dev_match(struct device *dev, struct device_driver *driver)
787 {
788 struct wmi_driver *wmi_driver =
789 container_of(driver, struct wmi_driver, driver);
790 struct wmi_block *wblock = dev_to_wblock(dev);
791 const struct wmi_device_id *id = wmi_driver->id_table;
792
793 if (id == NULL)
794 return 0;
795
796 while (*id->guid_string) {
797 uuid_le driver_guid;
798
799 if (WARN_ON(uuid_le_to_bin(id->guid_string, &driver_guid)))
800 continue;
801 if (!memcmp(&driver_guid, wblock->gblock.guid, 16))
802 return 1;
803
804 id++;
805 }
806
807 return 0;
808 }
809 static int wmi_char_open(struct inode *inode, struct file *filp)
810 {
811 const char *driver_name = filp->f_path.dentry->d_iname;
812 struct wmi_block *wblock = NULL;
813 struct wmi_block *next = NULL;
814
815 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
816 if (!wblock->dev.dev.driver)
817 continue;
818 if (strcmp(driver_name, wblock->dev.dev.driver->name) == 0) {
819 filp->private_data = wblock;
820 break;
821 }
822 }
823
824 if (!filp->private_data)
825 return -ENODEV;
826
827 return nonseekable_open(inode, filp);
828 }
829
830 static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
831 size_t length, loff_t *offset)
832 {
833 struct wmi_block *wblock = filp->private_data;
834
835 return simple_read_from_buffer(buffer, length, offset,
836 &wblock->req_buf_size,
837 sizeof(wblock->req_buf_size));
838 }
839
840 static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
841 {
842 struct wmi_ioctl_buffer __user *input =
843 (struct wmi_ioctl_buffer __user *) arg;
844 struct wmi_block *wblock = filp->private_data;
845 struct wmi_ioctl_buffer *buf = NULL;
846 struct wmi_driver *wdriver = NULL;
847 int ret;
848
849 if (_IOC_TYPE(cmd) != WMI_IOC)
850 return -ENOTTY;
851
852 /* make sure we're not calling a higher instance than exists*/
853 if (_IOC_NR(cmd) >= wblock->gblock.instance_count)
854 return -EINVAL;
855
856 mutex_lock(&wblock->char_mutex);
857 buf = wblock->handler_data;
858 if (get_user(buf->length, &input->length)) {
859 dev_dbg(&wblock->dev.dev, "Read length from user failed\n");
860 ret = -EFAULT;
861 goto out_ioctl;
862 }
863 /* if it's too small, abort */
864 if (buf->length < wblock->req_buf_size) {
865 dev_err(&wblock->dev.dev,
866 "Buffer %lld too small, need at least %lld\n",
867 buf->length, wblock->req_buf_size);
868 ret = -EINVAL;
869 goto out_ioctl;
870 }
871 /* if it's too big, warn, driver will only use what is needed */
872 if (buf->length > wblock->req_buf_size)
873 dev_warn(&wblock->dev.dev,
874 "Buffer %lld is bigger than required %lld\n",
875 buf->length, wblock->req_buf_size);
876
877 /* copy the structure from userspace */
878 if (copy_from_user(buf, input, wblock->req_buf_size)) {
879 dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n",
880 wblock->req_buf_size);
881 ret = -EFAULT;
882 goto out_ioctl;
883 }
884
885 /* let the driver do any filtering and do the call */
886 wdriver = container_of(wblock->dev.dev.driver,
887 struct wmi_driver, driver);
888 if (!try_module_get(wdriver->driver.owner)) {
889 ret = -EBUSY;
890 goto out_ioctl;
891 }
892 ret = wdriver->filter_callback(&wblock->dev, cmd, buf);
893 module_put(wdriver->driver.owner);
894 if (ret)
895 goto out_ioctl;
896
897 /* return the result (only up to our internal buffer size) */
898 if (copy_to_user(input, buf, wblock->req_buf_size)) {
899 dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n",
900 wblock->req_buf_size);
901 ret = -EFAULT;
902 }
903
904 out_ioctl:
905 mutex_unlock(&wblock->char_mutex);
906 return ret;
907 }
908
909 static const struct file_operations wmi_fops = {
910 .owner = THIS_MODULE,
911 .read = wmi_char_read,
912 .open = wmi_char_open,
913 .unlocked_ioctl = wmi_ioctl,
914 .compat_ioctl = compat_ptr_ioctl,
915 };
916
917 static int wmi_dev_probe(struct device *dev)
918 {
919 struct wmi_block *wblock = dev_to_wblock(dev);
920 struct wmi_driver *wdriver =
921 container_of(dev->driver, struct wmi_driver, driver);
922 int ret = 0;
923 char *buf;
924
925 if (ACPI_FAILURE(wmi_method_enable(wblock, 1)))
926 dev_warn(dev, "failed to enable device -- probing anyway\n");
927
928 if (wdriver->probe) {
929 ret = wdriver->probe(dev_to_wdev(dev),
930 find_guid_context(wblock, wdriver));
931 if (ret != 0)
932 goto probe_failure;
933 }
934
935 /* driver wants a character device made */
936 if (wdriver->filter_callback) {
937 /* check that required buffer size declared by driver or MOF */
938 if (!wblock->req_buf_size) {
939 dev_err(&wblock->dev.dev,
940 "Required buffer size not set\n");
941 ret = -EINVAL;
942 goto probe_failure;
943 }
944
945 wblock->handler_data = kmalloc(wblock->req_buf_size,
946 GFP_KERNEL);
947 if (!wblock->handler_data) {
948 ret = -ENOMEM;
949 goto probe_failure;
950 }
951
952 buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name);
953 if (!buf) {
954 ret = -ENOMEM;
955 goto probe_string_failure;
956 }
957 wblock->char_dev.minor = MISC_DYNAMIC_MINOR;
958 wblock->char_dev.name = buf;
959 wblock->char_dev.fops = &wmi_fops;
960 wblock->char_dev.mode = 0444;
961 ret = misc_register(&wblock->char_dev);
962 if (ret) {
963 dev_warn(dev, "failed to register char dev: %d\n", ret);
964 ret = -ENOMEM;
965 goto probe_misc_failure;
966 }
967 }
968
969 return 0;
970
971 probe_misc_failure:
972 kfree(buf);
973 probe_string_failure:
974 kfree(wblock->handler_data);
975 probe_failure:
976 if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
977 dev_warn(dev, "failed to disable device\n");
978 return ret;
979 }
980
981 static int wmi_dev_remove(struct device *dev)
982 {
983 struct wmi_block *wblock = dev_to_wblock(dev);
984 struct wmi_driver *wdriver =
985 container_of(dev->driver, struct wmi_driver, driver);
986 int ret = 0;
987
988 if (wdriver->filter_callback) {
989 misc_deregister(&wblock->char_dev);
990 kfree(wblock->char_dev.name);
991 kfree(wblock->handler_data);
992 }
993
994 if (wdriver->remove)
995 ret = wdriver->remove(dev_to_wdev(dev));
996
997 if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
998 dev_warn(dev, "failed to disable device\n");
999
1000 return ret;
1001 }
1002
1003 static struct class wmi_bus_class = {
1004 .name = "wmi_bus",
1005 };
1006
1007 static struct bus_type wmi_bus_type = {
1008 .name = "wmi",
1009 .dev_groups = wmi_groups,
1010 .match = wmi_dev_match,
1011 .uevent = wmi_dev_uevent,
1012 .probe = wmi_dev_probe,
1013 .remove = wmi_dev_remove,
1014 };
1015
1016 static const struct device_type wmi_type_event = {
1017 .name = "event",
1018 .groups = wmi_event_groups,
1019 .release = wmi_dev_release,
1020 };
1021
1022 static const struct device_type wmi_type_method = {
1023 .name = "method",
1024 .groups = wmi_method_groups,
1025 .release = wmi_dev_release,
1026 };
1027
1028 static const struct device_type wmi_type_data = {
1029 .name = "data",
1030 .groups = wmi_data_groups,
1031 .release = wmi_dev_release,
1032 };
1033
1034 static int wmi_create_device(struct device *wmi_bus_dev,
1035 const struct guid_block *gblock,
1036 struct wmi_block *wblock,
1037 struct acpi_device *device)
1038 {
1039 struct acpi_device_info *info;
1040 char method[5];
1041 int result;
1042
1043 if (gblock->flags & ACPI_WMI_EVENT) {
1044 wblock->dev.dev.type = &wmi_type_event;
1045 goto out_init;
1046 }
1047
1048 if (gblock->flags & ACPI_WMI_METHOD) {
1049 wblock->dev.dev.type = &wmi_type_method;
1050 mutex_init(&wblock->char_mutex);
1051 goto out_init;
1052 }
1053
1054 /*
1055 * Data Block Query Control Method (WQxx by convention) is
1056 * required per the WMI documentation. If it is not present,
1057 * we ignore this data block.
1058 */
1059 strcpy(method, "WQ");
1060 strncat(method, wblock->gblock.object_id, 2);
1061 result = get_subobj_info(device->handle, method, &info);
1062
1063 if (result) {
1064 dev_warn(wmi_bus_dev,
1065 "%s data block query control method not found\n",
1066 method);
1067 return result;
1068 }
1069
1070 wblock->dev.dev.type = &wmi_type_data;
1071
1072 /*
1073 * The Microsoft documentation specifically states:
1074 *
1075 * Data blocks registered with only a single instance
1076 * can ignore the parameter.
1077 *
1078 * ACPICA will get mad at us if we call the method with the wrong number
1079 * of arguments, so check what our method expects. (On some Dell
1080 * laptops, WQxx may not be a method at all.)
1081 */
1082 if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1083 wblock->read_takes_no_args = true;
1084
1085 kfree(info);
1086
1087 strcpy(method, "WS");
1088 strncat(method, wblock->gblock.object_id, 2);
1089 result = get_subobj_info(device->handle, method, NULL);
1090
1091 if (result == 0)
1092 wblock->dev.setable = true;
1093
1094 out_init:
1095 wblock->dev.dev.bus = &wmi_bus_type;
1096 wblock->dev.dev.parent = wmi_bus_dev;
1097
1098 dev_set_name(&wblock->dev.dev, "%pUL", gblock->guid);
1099
1100 device_initialize(&wblock->dev.dev);
1101
1102 return 0;
1103 }
1104
1105 static void wmi_free_devices(struct acpi_device *device)
1106 {
1107 struct wmi_block *wblock, *next;
1108
1109 /* Delete devices for all the GUIDs */
1110 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1111 if (wblock->acpi_device == device) {
1112 list_del(&wblock->list);
1113 device_unregister(&wblock->dev.dev);
1114 }
1115 }
1116 }
1117
1118 static bool guid_already_parsed(struct acpi_device *device,
1119 const u8 *guid)
1120 {
1121 struct wmi_block *wblock;
1122
1123 list_for_each_entry(wblock, &wmi_block_list, list) {
1124 if (memcmp(wblock->gblock.guid, guid, 16) == 0) {
1125 /*
1126 * Because we historically didn't track the relationship
1127 * between GUIDs and ACPI nodes, we don't know whether
1128 * we need to suppress GUIDs that are unique on a
1129 * given node but duplicated across nodes.
1130 */
1131 dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
1132 guid, dev_name(&wblock->acpi_device->dev));
1133 return true;
1134 }
1135 }
1136
1137 return false;
1138 }
1139
1140 /*
1141 * Parse the _WDG method for the GUID data blocks
1142 */
1143 static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
1144 {
1145 struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1146 const struct guid_block *gblock;
1147 struct wmi_block *wblock, *next;
1148 union acpi_object *obj;
1149 acpi_status status;
1150 int retval = 0;
1151 u32 i, total;
1152
1153 status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1154 if (ACPI_FAILURE(status))
1155 return -ENXIO;
1156
1157 obj = (union acpi_object *) out.pointer;
1158 if (!obj)
1159 return -ENXIO;
1160
1161 if (obj->type != ACPI_TYPE_BUFFER) {
1162 retval = -ENXIO;
1163 goto out_free_pointer;
1164 }
1165
1166 gblock = (const struct guid_block *)obj->buffer.pointer;
1167 total = obj->buffer.length / sizeof(struct guid_block);
1168
1169 for (i = 0; i < total; i++) {
1170 if (debug_dump_wdg)
1171 wmi_dump_wdg(&gblock[i]);
1172
1173 /*
1174 * Some WMI devices, like those for nVidia hooks, have a
1175 * duplicate GUID. It's not clear what we should do in this
1176 * case yet, so for now, we'll just ignore the duplicate
1177 * for device creation.
1178 */
1179 if (guid_already_parsed(device, gblock[i].guid))
1180 continue;
1181
1182 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
1183 if (!wblock) {
1184 retval = -ENOMEM;
1185 break;
1186 }
1187
1188 wblock->acpi_device = device;
1189 wblock->gblock = gblock[i];
1190
1191 retval = wmi_create_device(wmi_bus_dev, &gblock[i], wblock, device);
1192 if (retval) {
1193 kfree(wblock);
1194 continue;
1195 }
1196
1197 list_add_tail(&wblock->list, &wmi_block_list);
1198
1199 if (debug_event) {
1200 wblock->handler = wmi_notify_debug;
1201 wmi_method_enable(wblock, 1);
1202 }
1203 }
1204
1205 /*
1206 * Now that all of the devices are created, add them to the
1207 * device tree and probe subdrivers.
1208 */
1209 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1210 if (wblock->acpi_device != device)
1211 continue;
1212
1213 retval = device_add(&wblock->dev.dev);
1214 if (retval) {
1215 dev_err(wmi_bus_dev, "failed to register %pUL\n",
1216 wblock->gblock.guid);
1217 if (debug_event)
1218 wmi_method_enable(wblock, 0);
1219 list_del(&wblock->list);
1220 put_device(&wblock->dev.dev);
1221 }
1222 }
1223
1224 out_free_pointer:
1225 kfree(out.pointer);
1226 return retval;
1227 }
1228
1229 /*
1230 * WMI can have EmbeddedControl access regions. In which case, we just want to
1231 * hand these off to the EC driver.
1232 */
1233 static acpi_status
1234 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1235 u32 bits, u64 *value,
1236 void *handler_context, void *region_context)
1237 {
1238 int result = 0, i = 0;
1239 u8 temp = 0;
1240
1241 if ((address > 0xFF) || !value)
1242 return AE_BAD_PARAMETER;
1243
1244 if (function != ACPI_READ && function != ACPI_WRITE)
1245 return AE_BAD_PARAMETER;
1246
1247 if (bits != 8)
1248 return AE_BAD_PARAMETER;
1249
1250 if (function == ACPI_READ) {
1251 result = ec_read(address, &temp);
1252 (*value) |= ((u64)temp) << i;
1253 } else {
1254 temp = 0xff & ((*value) >> i);
1255 result = ec_write(address, temp);
1256 }
1257
1258 switch (result) {
1259 case -EINVAL:
1260 return AE_BAD_PARAMETER;
1261 break;
1262 case -ENODEV:
1263 return AE_NOT_FOUND;
1264 break;
1265 case -ETIME:
1266 return AE_TIME;
1267 break;
1268 default:
1269 return AE_OK;
1270 }
1271 }
1272
1273 static void acpi_wmi_notify_handler(acpi_handle handle, u32 event,
1274 void *context)
1275 {
1276 struct guid_block *block;
1277 struct wmi_block *wblock;
1278 bool found_it = false;
1279
1280 list_for_each_entry(wblock, &wmi_block_list, list) {
1281 block = &wblock->gblock;
1282
1283 if (wblock->acpi_device->handle == handle &&
1284 (block->flags & ACPI_WMI_EVENT) &&
1285 (block->notify_id == event))
1286 {
1287 found_it = true;
1288 break;
1289 }
1290 }
1291
1292 if (!found_it)
1293 return;
1294
1295 /* If a driver is bound, then notify the driver. */
1296 if (wblock->dev.dev.driver) {
1297 struct wmi_driver *driver;
1298 struct acpi_object_list input;
1299 union acpi_object params[1];
1300 struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL };
1301 acpi_status status;
1302
1303 driver = container_of(wblock->dev.dev.driver,
1304 struct wmi_driver, driver);
1305
1306 input.count = 1;
1307 input.pointer = params;
1308 params[0].type = ACPI_TYPE_INTEGER;
1309 params[0].integer.value = event;
1310
1311 status = acpi_evaluate_object(wblock->acpi_device->handle,
1312 "_WED", &input, &evdata);
1313 if (ACPI_FAILURE(status)) {
1314 dev_warn(&wblock->dev.dev,
1315 "failed to get event data\n");
1316 return;
1317 }
1318
1319 if (driver->notify)
1320 driver->notify(&wblock->dev,
1321 (union acpi_object *)evdata.pointer);
1322
1323 kfree(evdata.pointer);
1324 } else if (wblock->handler) {
1325 /* Legacy handler */
1326 wblock->handler(event, wblock->handler_data);
1327 }
1328
1329 if (debug_event) {
1330 pr_info("DEBUG Event GUID: %pUL\n",
1331 wblock->gblock.guid);
1332 }
1333
1334 acpi_bus_generate_netlink_event(
1335 wblock->acpi_device->pnp.device_class,
1336 dev_name(&wblock->dev.dev),
1337 event, 0);
1338
1339 }
1340
1341 static int acpi_wmi_remove(struct platform_device *device)
1342 {
1343 struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev);
1344
1345 acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1346 acpi_wmi_notify_handler);
1347 acpi_remove_address_space_handler(acpi_device->handle,
1348 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
1349 wmi_free_devices(acpi_device);
1350 device_destroy(&wmi_bus_class, MKDEV(0, 0));
1351
1352 return 0;
1353 }
1354
1355 static int acpi_wmi_probe(struct platform_device *device)
1356 {
1357 struct acpi_device *acpi_device;
1358 struct device *wmi_bus_dev;
1359 acpi_status status;
1360 int error;
1361
1362 acpi_device = ACPI_COMPANION(&device->dev);
1363 if (!acpi_device) {
1364 dev_err(&device->dev, "ACPI companion is missing\n");
1365 return -ENODEV;
1366 }
1367
1368 status = acpi_install_address_space_handler(acpi_device->handle,
1369 ACPI_ADR_SPACE_EC,
1370 &acpi_wmi_ec_space_handler,
1371 NULL, NULL);
1372 if (ACPI_FAILURE(status)) {
1373 dev_err(&device->dev, "Error installing EC region handler\n");
1374 return -ENODEV;
1375 }
1376
1377 status = acpi_install_notify_handler(acpi_device->handle,
1378 ACPI_DEVICE_NOTIFY,
1379 acpi_wmi_notify_handler,
1380 NULL);
1381 if (ACPI_FAILURE(status)) {
1382 dev_err(&device->dev, "Error installing notify handler\n");
1383 error = -ENODEV;
1384 goto err_remove_ec_handler;
1385 }
1386
1387 wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0),
1388 NULL, "wmi_bus-%s", dev_name(&device->dev));
1389 if (IS_ERR(wmi_bus_dev)) {
1390 error = PTR_ERR(wmi_bus_dev);
1391 goto err_remove_notify_handler;
1392 }
1393 dev_set_drvdata(&device->dev, wmi_bus_dev);
1394
1395 error = parse_wdg(wmi_bus_dev, acpi_device);
1396 if (error) {
1397 pr_err("Failed to parse WDG method\n");
1398 goto err_remove_busdev;
1399 }
1400
1401 return 0;
1402
1403 err_remove_busdev:
1404 device_destroy(&wmi_bus_class, MKDEV(0, 0));
1405
1406 err_remove_notify_handler:
1407 acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1408 acpi_wmi_notify_handler);
1409
1410 err_remove_ec_handler:
1411 acpi_remove_address_space_handler(acpi_device->handle,
1412 ACPI_ADR_SPACE_EC,
1413 &acpi_wmi_ec_space_handler);
1414
1415 return error;
1416 }
1417
1418 int __must_check __wmi_driver_register(struct wmi_driver *driver,
1419 struct module *owner)
1420 {
1421 driver->driver.owner = owner;
1422 driver->driver.bus = &wmi_bus_type;
1423
1424 return driver_register(&driver->driver);
1425 }
1426 EXPORT_SYMBOL(__wmi_driver_register);
1427
1428 void wmi_driver_unregister(struct wmi_driver *driver)
1429 {
1430 driver_unregister(&driver->driver);
1431 }
1432 EXPORT_SYMBOL(wmi_driver_unregister);
1433
1434 static int __init acpi_wmi_init(void)
1435 {
1436 int error;
1437
1438 if (acpi_disabled)
1439 return -ENODEV;
1440
1441 error = class_register(&wmi_bus_class);
1442 if (error)
1443 return error;
1444
1445 error = bus_register(&wmi_bus_type);
1446 if (error)
1447 goto err_unreg_class;
1448
1449 error = platform_driver_register(&acpi_wmi_driver);
1450 if (error) {
1451 pr_err("Error loading mapper\n");
1452 goto err_unreg_bus;
1453 }
1454
1455 return 0;
1456
1457 err_unreg_bus:
1458 bus_unregister(&wmi_bus_type);
1459
1460 err_unreg_class:
1461 class_unregister(&wmi_bus_class);
1462
1463 return error;
1464 }
1465
1466 static void __exit acpi_wmi_exit(void)
1467 {
1468 platform_driver_unregister(&acpi_wmi_driver);
1469 bus_unregister(&wmi_bus_type);
1470 class_unregister(&wmi_bus_class);
1471 }
1472
1473 subsys_initcall_sync(acpi_wmi_init);
1474 module_exit(acpi_wmi_exit);
Linux with added FPC-III support