xref: /openbmc/linux/drivers/platform/x86/wmi.c (revision 62e59c4e)
1 /*
2  *  ACPI-WMI mapping driver
3  *
4  *  Copyright (C) 2007-2008 Carlos Corbacho <carlos@strangeworlds.co.uk>
5  *
6  *  GUID parsing code from ldm.c is:
7  *   Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
8  *   Copyright (c) 2001-2007 Anton Altaparmakov
9  *   Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
10  *
11  *  WMI bus infrastructure by Andrew Lutomirski and Darren Hart:
12  *    Copyright (C) 2015 Andrew Lutomirski
13  *    Copyright (C) 2017 VMware, Inc. All Rights Reserved.
14  *
15  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
16  *
17  *  This program is free software; you can redistribute it and/or modify
18  *  it under the terms of the GNU General Public License as published by
19  *  the Free Software Foundation; either version 2 of the License, or (at
20  *  your option) any later version.
21  *
22  *  This program is distributed in the hope that it will be useful, but
23  *  WITHOUT ANY WARRANTY; without even the implied warranty of
24  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
25  *  General Public License for more details.
26  *
27  *  You should have received a copy of the GNU General Public License along
28  *  with this program; if not, write to the Free Software Foundation, Inc.,
29  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
30  *
31  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
32  */
33 
34 #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
35 
36 #include <linux/acpi.h>
37 #include <linux/device.h>
38 #include <linux/init.h>
39 #include <linux/kernel.h>
40 #include <linux/list.h>
41 #include <linux/miscdevice.h>
42 #include <linux/module.h>
43 #include <linux/platform_device.h>
44 #include <linux/slab.h>
45 #include <linux/types.h>
46 #include <linux/uaccess.h>
47 #include <linux/uuid.h>
48 #include <linux/wmi.h>
49 #include <uapi/linux/wmi.h>
50 
51 ACPI_MODULE_NAME("wmi");
52 MODULE_AUTHOR("Carlos Corbacho");
53 MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
54 MODULE_LICENSE("GPL");
55 
56 static LIST_HEAD(wmi_block_list);
57 
58 struct guid_block {
59 	char guid[16];
60 	union {
61 		char object_id[2];
62 		struct {
63 			unsigned char notify_id;
64 			unsigned char reserved;
65 		};
66 	};
67 	u8 instance_count;
68 	u8 flags;
69 };
70 
71 struct wmi_block {
72 	struct wmi_device dev;
73 	struct list_head list;
74 	struct guid_block gblock;
75 	struct miscdevice char_dev;
76 	struct mutex char_mutex;
77 	struct acpi_device *acpi_device;
78 	wmi_notify_handler handler;
79 	void *handler_data;
80 	u64 req_buf_size;
81 
82 	bool read_takes_no_args;
83 };
84 
85 
86 /*
87  * If the GUID data block is marked as expensive, we must enable and
88  * explicitily disable data collection.
89  */
90 #define ACPI_WMI_EXPENSIVE   0x1
91 #define ACPI_WMI_METHOD      0x2	/* GUID is a method */
92 #define ACPI_WMI_STRING      0x4	/* GUID takes & returns a string */
93 #define ACPI_WMI_EVENT       0x8	/* GUID is an event */
94 
95 static bool debug_event;
96 module_param(debug_event, bool, 0444);
97 MODULE_PARM_DESC(debug_event,
98 		 "Log WMI Events [0/1]");
99 
100 static bool debug_dump_wdg;
101 module_param(debug_dump_wdg, bool, 0444);
102 MODULE_PARM_DESC(debug_dump_wdg,
103 		 "Dump available WMI interfaces [0/1]");
104 
105 static int acpi_wmi_remove(struct platform_device *device);
106 static int acpi_wmi_probe(struct platform_device *device);
107 
108 static const struct acpi_device_id wmi_device_ids[] = {
109 	{"PNP0C14", 0},
110 	{"pnp0c14", 0},
111 	{"", 0},
112 };
113 MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
114 
115 static struct platform_driver acpi_wmi_driver = {
116 	.driver = {
117 		.name = "acpi-wmi",
118 		.acpi_match_table = wmi_device_ids,
119 	},
120 	.probe = acpi_wmi_probe,
121 	.remove = acpi_wmi_remove,
122 };
123 
124 /*
125  * GUID parsing functions
126  */
127 
128 static bool find_guid(const char *guid_string, struct wmi_block **out)
129 {
130 	uuid_le guid_input;
131 	struct wmi_block *wblock;
132 	struct guid_block *block;
133 
134 	if (uuid_le_to_bin(guid_string, &guid_input))
135 		return false;
136 
137 	list_for_each_entry(wblock, &wmi_block_list, list) {
138 		block = &wblock->gblock;
139 
140 		if (memcmp(block->guid, &guid_input, 16) == 0) {
141 			if (out)
142 				*out = wblock;
143 			return true;
144 		}
145 	}
146 	return false;
147 }
148 
149 static int get_subobj_info(acpi_handle handle, const char *pathname,
150 			   struct acpi_device_info **info)
151 {
152 	struct acpi_device_info *dummy_info, **info_ptr;
153 	acpi_handle subobj_handle;
154 	acpi_status status;
155 
156 	status = acpi_get_handle(handle, (char *)pathname, &subobj_handle);
157 	if (status == AE_NOT_FOUND)
158 		return -ENOENT;
159 	else if (ACPI_FAILURE(status))
160 		return -EIO;
161 
162 	info_ptr = info ? info : &dummy_info;
163 	status = acpi_get_object_info(subobj_handle, info_ptr);
164 	if (ACPI_FAILURE(status))
165 		return -EIO;
166 
167 	if (!info)
168 		kfree(dummy_info);
169 
170 	return 0;
171 }
172 
173 static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable)
174 {
175 	struct guid_block *block = NULL;
176 	char method[5];
177 	acpi_status status;
178 	acpi_handle handle;
179 
180 	block = &wblock->gblock;
181 	handle = wblock->acpi_device->handle;
182 
183 	snprintf(method, 5, "WE%02X", block->notify_id);
184 	status = acpi_execute_simple_method(handle, method, enable);
185 
186 	if (status != AE_OK && status != AE_NOT_FOUND)
187 		return status;
188 	else
189 		return AE_OK;
190 }
191 
192 /*
193  * Exported WMI functions
194  */
195 
196 /**
197  * set_required_buffer_size - Sets the buffer size needed for performing IOCTL
198  * @wdev: A wmi bus device from a driver
199  * @instance: Instance index
200  *
201  * Allocates memory needed for buffer, stores the buffer size in that memory
202  */
203 int set_required_buffer_size(struct wmi_device *wdev, u64 length)
204 {
205 	struct wmi_block *wblock;
206 
207 	wblock = container_of(wdev, struct wmi_block, dev);
208 	wblock->req_buf_size = length;
209 
210 	return 0;
211 }
212 EXPORT_SYMBOL_GPL(set_required_buffer_size);
213 
214 /**
215  * wmi_evaluate_method - Evaluate a WMI method
216  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
217  * @instance: Instance index
218  * @method_id: Method ID to call
219  * &in: Buffer containing input for the method call
220  * &out: Empty buffer to return the method results
221  *
222  * Call an ACPI-WMI method
223  */
224 acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
225 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
226 {
227 	struct wmi_block *wblock = NULL;
228 
229 	if (!find_guid(guid_string, &wblock))
230 		return AE_ERROR;
231 	return wmidev_evaluate_method(&wblock->dev, instance, method_id,
232 				      in, out);
233 }
234 EXPORT_SYMBOL_GPL(wmi_evaluate_method);
235 
236 /**
237  * wmidev_evaluate_method - Evaluate a WMI method
238  * @wdev: A wmi bus device from a driver
239  * @instance: Instance index
240  * @method_id: Method ID to call
241  * &in: Buffer containing input for the method call
242  * &out: Empty buffer to return the method results
243  *
244  * Call an ACPI-WMI method
245  */
246 acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance,
247 	u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
248 {
249 	struct guid_block *block = NULL;
250 	struct wmi_block *wblock = NULL;
251 	acpi_handle handle;
252 	acpi_status status;
253 	struct acpi_object_list input;
254 	union acpi_object params[3];
255 	char method[5] = "WM";
256 
257 	wblock = container_of(wdev, struct wmi_block, dev);
258 	block = &wblock->gblock;
259 	handle = wblock->acpi_device->handle;
260 
261 	if (!(block->flags & ACPI_WMI_METHOD))
262 		return AE_BAD_DATA;
263 
264 	if (block->instance_count <= instance)
265 		return AE_BAD_PARAMETER;
266 
267 	input.count = 2;
268 	input.pointer = params;
269 	params[0].type = ACPI_TYPE_INTEGER;
270 	params[0].integer.value = instance;
271 	params[1].type = ACPI_TYPE_INTEGER;
272 	params[1].integer.value = method_id;
273 
274 	if (in) {
275 		input.count = 3;
276 
277 		if (block->flags & ACPI_WMI_STRING) {
278 			params[2].type = ACPI_TYPE_STRING;
279 		} else {
280 			params[2].type = ACPI_TYPE_BUFFER;
281 		}
282 		params[2].buffer.length = in->length;
283 		params[2].buffer.pointer = in->pointer;
284 	}
285 
286 	strncat(method, block->object_id, 2);
287 
288 	status = acpi_evaluate_object(handle, method, &input, out);
289 
290 	return status;
291 }
292 EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
293 
294 static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
295 				 struct acpi_buffer *out)
296 {
297 	struct guid_block *block = NULL;
298 	acpi_handle handle;
299 	acpi_status status, wc_status = AE_ERROR;
300 	struct acpi_object_list input;
301 	union acpi_object wq_params[1];
302 	char method[5];
303 	char wc_method[5] = "WC";
304 
305 	if (!out)
306 		return AE_BAD_PARAMETER;
307 
308 	block = &wblock->gblock;
309 	handle = wblock->acpi_device->handle;
310 
311 	if (block->instance_count <= instance)
312 		return AE_BAD_PARAMETER;
313 
314 	/* Check GUID is a data block */
315 	if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
316 		return AE_ERROR;
317 
318 	input.count = 1;
319 	input.pointer = wq_params;
320 	wq_params[0].type = ACPI_TYPE_INTEGER;
321 	wq_params[0].integer.value = instance;
322 
323 	if (instance == 0 && wblock->read_takes_no_args)
324 		input.count = 0;
325 
326 	/*
327 	 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
328 	 * enable collection.
329 	 */
330 	if (block->flags & ACPI_WMI_EXPENSIVE) {
331 		strncat(wc_method, block->object_id, 2);
332 
333 		/*
334 		 * Some GUIDs break the specification by declaring themselves
335 		 * expensive, but have no corresponding WCxx method. So we
336 		 * should not fail if this happens.
337 		 */
338 		if (acpi_has_method(handle, wc_method))
339 			wc_status = acpi_execute_simple_method(handle,
340 								wc_method, 1);
341 	}
342 
343 	strcpy(method, "WQ");
344 	strncat(method, block->object_id, 2);
345 
346 	status = acpi_evaluate_object(handle, method, &input, out);
347 
348 	/*
349 	 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
350 	 * the WQxx method failed - we should disable collection anyway.
351 	 */
352 	if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
353 		status = acpi_execute_simple_method(handle, wc_method, 0);
354 	}
355 
356 	return status;
357 }
358 
359 /**
360  * wmi_query_block - Return contents of a WMI block (deprecated)
361  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
362  * @instance: Instance index
363  * &out: Empty buffer to return the contents of the data block to
364  *
365  * Return the contents of an ACPI-WMI data block to a buffer
366  */
367 acpi_status wmi_query_block(const char *guid_string, u8 instance,
368 			    struct acpi_buffer *out)
369 {
370 	struct wmi_block *wblock;
371 
372 	if (!guid_string)
373 		return AE_BAD_PARAMETER;
374 
375 	if (!find_guid(guid_string, &wblock))
376 		return AE_ERROR;
377 
378 	return __query_block(wblock, instance, out);
379 }
380 EXPORT_SYMBOL_GPL(wmi_query_block);
381 
382 union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
383 {
384 	struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
385 	struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
386 
387 	if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
388 		return NULL;
389 
390 	return (union acpi_object *)out.pointer;
391 }
392 EXPORT_SYMBOL_GPL(wmidev_block_query);
393 
394 /**
395  * wmi_set_block - Write to a WMI block
396  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
397  * @instance: Instance index
398  * &in: Buffer containing new values for the data block
399  *
400  * Write the contents of the input buffer to an ACPI-WMI data block
401  */
402 acpi_status wmi_set_block(const char *guid_string, u8 instance,
403 			  const struct acpi_buffer *in)
404 {
405 	struct guid_block *block = NULL;
406 	struct wmi_block *wblock = NULL;
407 	acpi_handle handle;
408 	struct acpi_object_list input;
409 	union acpi_object params[2];
410 	char method[5] = "WS";
411 
412 	if (!guid_string || !in)
413 		return AE_BAD_DATA;
414 
415 	if (!find_guid(guid_string, &wblock))
416 		return AE_ERROR;
417 
418 	block = &wblock->gblock;
419 	handle = wblock->acpi_device->handle;
420 
421 	if (block->instance_count <= instance)
422 		return AE_BAD_PARAMETER;
423 
424 	/* Check GUID is a data block */
425 	if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
426 		return AE_ERROR;
427 
428 	input.count = 2;
429 	input.pointer = params;
430 	params[0].type = ACPI_TYPE_INTEGER;
431 	params[0].integer.value = instance;
432 
433 	if (block->flags & ACPI_WMI_STRING) {
434 		params[1].type = ACPI_TYPE_STRING;
435 	} else {
436 		params[1].type = ACPI_TYPE_BUFFER;
437 	}
438 	params[1].buffer.length = in->length;
439 	params[1].buffer.pointer = in->pointer;
440 
441 	strncat(method, block->object_id, 2);
442 
443 	return acpi_evaluate_object(handle, method, &input, NULL);
444 }
445 EXPORT_SYMBOL_GPL(wmi_set_block);
446 
447 static void wmi_dump_wdg(const struct guid_block *g)
448 {
449 	pr_info("%pUL:\n", g->guid);
450 	if (g->flags & ACPI_WMI_EVENT)
451 		pr_info("\tnotify_id: 0x%02X\n", g->notify_id);
452 	else
453 		pr_info("\tobject_id: %2pE\n", g->object_id);
454 	pr_info("\tinstance_count: %d\n", g->instance_count);
455 	pr_info("\tflags: %#x", g->flags);
456 	if (g->flags) {
457 		if (g->flags & ACPI_WMI_EXPENSIVE)
458 			pr_cont(" ACPI_WMI_EXPENSIVE");
459 		if (g->flags & ACPI_WMI_METHOD)
460 			pr_cont(" ACPI_WMI_METHOD");
461 		if (g->flags & ACPI_WMI_STRING)
462 			pr_cont(" ACPI_WMI_STRING");
463 		if (g->flags & ACPI_WMI_EVENT)
464 			pr_cont(" ACPI_WMI_EVENT");
465 	}
466 	pr_cont("\n");
467 
468 }
469 
470 static void wmi_notify_debug(u32 value, void *context)
471 {
472 	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
473 	union acpi_object *obj;
474 	acpi_status status;
475 
476 	status = wmi_get_event_data(value, &response);
477 	if (status != AE_OK) {
478 		pr_info("bad event status 0x%x\n", status);
479 		return;
480 	}
481 
482 	obj = (union acpi_object *)response.pointer;
483 
484 	if (!obj)
485 		return;
486 
487 	pr_info("DEBUG Event ");
488 	switch(obj->type) {
489 	case ACPI_TYPE_BUFFER:
490 		pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
491 		break;
492 	case ACPI_TYPE_STRING:
493 		pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
494 		break;
495 	case ACPI_TYPE_INTEGER:
496 		pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
497 		break;
498 	case ACPI_TYPE_PACKAGE:
499 		pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
500 		break;
501 	default:
502 		pr_cont("object type 0x%X\n", obj->type);
503 	}
504 	kfree(obj);
505 }
506 
507 /**
508  * wmi_install_notify_handler - Register handler for WMI events
509  * @handler: Function to handle notifications
510  * @data: Data to be returned to handler when event is fired
511  *
512  * Register a handler for events sent to the ACPI-WMI mapper device.
513  */
514 acpi_status wmi_install_notify_handler(const char *guid,
515 wmi_notify_handler handler, void *data)
516 {
517 	struct wmi_block *block;
518 	acpi_status status = AE_NOT_EXIST;
519 	uuid_le guid_input;
520 
521 	if (!guid || !handler)
522 		return AE_BAD_PARAMETER;
523 
524 	if (uuid_le_to_bin(guid, &guid_input))
525 		return AE_BAD_PARAMETER;
526 
527 	list_for_each_entry(block, &wmi_block_list, list) {
528 		acpi_status wmi_status;
529 
530 		if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
531 			if (block->handler &&
532 			    block->handler != wmi_notify_debug)
533 				return AE_ALREADY_ACQUIRED;
534 
535 			block->handler = handler;
536 			block->handler_data = data;
537 
538 			wmi_status = wmi_method_enable(block, 1);
539 			if ((wmi_status != AE_OK) ||
540 			    ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
541 				status = wmi_status;
542 		}
543 	}
544 
545 	return status;
546 }
547 EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
548 
549 /**
550  * wmi_uninstall_notify_handler - Unregister handler for WMI events
551  *
552  * Unregister handler for events sent to the ACPI-WMI mapper device.
553  */
554 acpi_status wmi_remove_notify_handler(const char *guid)
555 {
556 	struct wmi_block *block;
557 	acpi_status status = AE_NOT_EXIST;
558 	uuid_le guid_input;
559 
560 	if (!guid)
561 		return AE_BAD_PARAMETER;
562 
563 	if (uuid_le_to_bin(guid, &guid_input))
564 		return AE_BAD_PARAMETER;
565 
566 	list_for_each_entry(block, &wmi_block_list, list) {
567 		acpi_status wmi_status;
568 
569 		if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
570 			if (!block->handler ||
571 			    block->handler == wmi_notify_debug)
572 				return AE_NULL_ENTRY;
573 
574 			if (debug_event) {
575 				block->handler = wmi_notify_debug;
576 				status = AE_OK;
577 			} else {
578 				wmi_status = wmi_method_enable(block, 0);
579 				block->handler = NULL;
580 				block->handler_data = NULL;
581 				if ((wmi_status != AE_OK) ||
582 				    ((wmi_status == AE_OK) &&
583 				     (status == AE_NOT_EXIST)))
584 					status = wmi_status;
585 			}
586 		}
587 	}
588 
589 	return status;
590 }
591 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
592 
593 /**
594  * wmi_get_event_data - Get WMI data associated with an event
595  *
596  * @event: Event to find
597  * @out: Buffer to hold event data. out->pointer should be freed with kfree()
598  *
599  * Returns extra data associated with an event in WMI.
600  */
601 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
602 {
603 	struct acpi_object_list input;
604 	union acpi_object params[1];
605 	struct guid_block *gblock;
606 	struct wmi_block *wblock;
607 
608 	input.count = 1;
609 	input.pointer = params;
610 	params[0].type = ACPI_TYPE_INTEGER;
611 	params[0].integer.value = event;
612 
613 	list_for_each_entry(wblock, &wmi_block_list, list) {
614 		gblock = &wblock->gblock;
615 
616 		if ((gblock->flags & ACPI_WMI_EVENT) &&
617 			(gblock->notify_id == event))
618 			return acpi_evaluate_object(wblock->acpi_device->handle,
619 				"_WED", &input, out);
620 	}
621 
622 	return AE_NOT_FOUND;
623 }
624 EXPORT_SYMBOL_GPL(wmi_get_event_data);
625 
626 /**
627  * wmi_has_guid - Check if a GUID is available
628  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
629  *
630  * Check if a given GUID is defined by _WDG
631  */
632 bool wmi_has_guid(const char *guid_string)
633 {
634 	return find_guid(guid_string, NULL);
635 }
636 EXPORT_SYMBOL_GPL(wmi_has_guid);
637 
638 static struct wmi_block *dev_to_wblock(struct device *dev)
639 {
640 	return container_of(dev, struct wmi_block, dev.dev);
641 }
642 
643 static struct wmi_device *dev_to_wdev(struct device *dev)
644 {
645 	return container_of(dev, struct wmi_device, dev);
646 }
647 
648 /*
649  * sysfs interface
650  */
651 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
652 			     char *buf)
653 {
654 	struct wmi_block *wblock = dev_to_wblock(dev);
655 
656 	return sprintf(buf, "wmi:%pUL\n", wblock->gblock.guid);
657 }
658 static DEVICE_ATTR_RO(modalias);
659 
660 static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
661 			 char *buf)
662 {
663 	struct wmi_block *wblock = dev_to_wblock(dev);
664 
665 	return sprintf(buf, "%pUL\n", wblock->gblock.guid);
666 }
667 static DEVICE_ATTR_RO(guid);
668 
669 static ssize_t instance_count_show(struct device *dev,
670 				   struct device_attribute *attr, char *buf)
671 {
672 	struct wmi_block *wblock = dev_to_wblock(dev);
673 
674 	return sprintf(buf, "%d\n", (int)wblock->gblock.instance_count);
675 }
676 static DEVICE_ATTR_RO(instance_count);
677 
678 static ssize_t expensive_show(struct device *dev,
679 			      struct device_attribute *attr, char *buf)
680 {
681 	struct wmi_block *wblock = dev_to_wblock(dev);
682 
683 	return sprintf(buf, "%d\n",
684 		       (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
685 }
686 static DEVICE_ATTR_RO(expensive);
687 
688 static struct attribute *wmi_attrs[] = {
689 	&dev_attr_modalias.attr,
690 	&dev_attr_guid.attr,
691 	&dev_attr_instance_count.attr,
692 	&dev_attr_expensive.attr,
693 	NULL,
694 };
695 ATTRIBUTE_GROUPS(wmi);
696 
697 static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
698 			      char *buf)
699 {
700 	struct wmi_block *wblock = dev_to_wblock(dev);
701 
702 	return sprintf(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
703 }
704 static DEVICE_ATTR_RO(notify_id);
705 
706 static struct attribute *wmi_event_attrs[] = {
707 	&dev_attr_notify_id.attr,
708 	NULL,
709 };
710 ATTRIBUTE_GROUPS(wmi_event);
711 
712 static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
713 			      char *buf)
714 {
715 	struct wmi_block *wblock = dev_to_wblock(dev);
716 
717 	return sprintf(buf, "%c%c\n", wblock->gblock.object_id[0],
718 		       wblock->gblock.object_id[1]);
719 }
720 static DEVICE_ATTR_RO(object_id);
721 
722 static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
723 			    char *buf)
724 {
725 	struct wmi_device *wdev = dev_to_wdev(dev);
726 
727 	return sprintf(buf, "%d\n", (int)wdev->setable);
728 }
729 static DEVICE_ATTR_RO(setable);
730 
731 static struct attribute *wmi_data_attrs[] = {
732 	&dev_attr_object_id.attr,
733 	&dev_attr_setable.attr,
734 	NULL,
735 };
736 ATTRIBUTE_GROUPS(wmi_data);
737 
738 static struct attribute *wmi_method_attrs[] = {
739 	&dev_attr_object_id.attr,
740 	NULL,
741 };
742 ATTRIBUTE_GROUPS(wmi_method);
743 
744 static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
745 {
746 	struct wmi_block *wblock = dev_to_wblock(dev);
747 
748 	if (add_uevent_var(env, "MODALIAS=wmi:%pUL", wblock->gblock.guid))
749 		return -ENOMEM;
750 
751 	if (add_uevent_var(env, "WMI_GUID=%pUL", wblock->gblock.guid))
752 		return -ENOMEM;
753 
754 	return 0;
755 }
756 
757 static void wmi_dev_release(struct device *dev)
758 {
759 	struct wmi_block *wblock = dev_to_wblock(dev);
760 
761 	kfree(wblock);
762 }
763 
764 static int wmi_dev_match(struct device *dev, struct device_driver *driver)
765 {
766 	struct wmi_driver *wmi_driver =
767 		container_of(driver, struct wmi_driver, driver);
768 	struct wmi_block *wblock = dev_to_wblock(dev);
769 	const struct wmi_device_id *id = wmi_driver->id_table;
770 
771 	if (id == NULL)
772 		return 0;
773 
774 	while (*id->guid_string) {
775 		uuid_le driver_guid;
776 
777 		if (WARN_ON(uuid_le_to_bin(id->guid_string, &driver_guid)))
778 			continue;
779 		if (!memcmp(&driver_guid, wblock->gblock.guid, 16))
780 			return 1;
781 
782 		id++;
783 	}
784 
785 	return 0;
786 }
787 static int wmi_char_open(struct inode *inode, struct file *filp)
788 {
789 	const char *driver_name = filp->f_path.dentry->d_iname;
790 	struct wmi_block *wblock = NULL;
791 	struct wmi_block *next = NULL;
792 
793 	list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
794 		if (!wblock->dev.dev.driver)
795 			continue;
796 		if (strcmp(driver_name, wblock->dev.dev.driver->name) == 0) {
797 			filp->private_data = wblock;
798 			break;
799 		}
800 	}
801 
802 	if (!filp->private_data)
803 		return -ENODEV;
804 
805 	return nonseekable_open(inode, filp);
806 }
807 
808 static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
809 	size_t length, loff_t *offset)
810 {
811 	struct wmi_block *wblock = filp->private_data;
812 
813 	return simple_read_from_buffer(buffer, length, offset,
814 				       &wblock->req_buf_size,
815 				       sizeof(wblock->req_buf_size));
816 }
817 
818 static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
819 {
820 	struct wmi_ioctl_buffer __user *input =
821 		(struct wmi_ioctl_buffer __user *) arg;
822 	struct wmi_block *wblock = filp->private_data;
823 	struct wmi_ioctl_buffer *buf = NULL;
824 	struct wmi_driver *wdriver = NULL;
825 	int ret;
826 
827 	if (_IOC_TYPE(cmd) != WMI_IOC)
828 		return -ENOTTY;
829 
830 	/* make sure we're not calling a higher instance than exists*/
831 	if (_IOC_NR(cmd) >= wblock->gblock.instance_count)
832 		return -EINVAL;
833 
834 	mutex_lock(&wblock->char_mutex);
835 	buf = wblock->handler_data;
836 	if (get_user(buf->length, &input->length)) {
837 		dev_dbg(&wblock->dev.dev, "Read length from user failed\n");
838 		ret = -EFAULT;
839 		goto out_ioctl;
840 	}
841 	/* if it's too small, abort */
842 	if (buf->length < wblock->req_buf_size) {
843 		dev_err(&wblock->dev.dev,
844 			"Buffer %lld too small, need at least %lld\n",
845 			buf->length, wblock->req_buf_size);
846 		ret = -EINVAL;
847 		goto out_ioctl;
848 	}
849 	/* if it's too big, warn, driver will only use what is needed */
850 	if (buf->length > wblock->req_buf_size)
851 		dev_warn(&wblock->dev.dev,
852 			"Buffer %lld is bigger than required %lld\n",
853 			buf->length, wblock->req_buf_size);
854 
855 	/* copy the structure from userspace */
856 	if (copy_from_user(buf, input, wblock->req_buf_size)) {
857 		dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n",
858 			wblock->req_buf_size);
859 		ret = -EFAULT;
860 		goto out_ioctl;
861 	}
862 
863 	/* let the driver do any filtering and do the call */
864 	wdriver = container_of(wblock->dev.dev.driver,
865 			       struct wmi_driver, driver);
866 	if (!try_module_get(wdriver->driver.owner)) {
867 		ret = -EBUSY;
868 		goto out_ioctl;
869 	}
870 	ret = wdriver->filter_callback(&wblock->dev, cmd, buf);
871 	module_put(wdriver->driver.owner);
872 	if (ret)
873 		goto out_ioctl;
874 
875 	/* return the result (only up to our internal buffer size) */
876 	if (copy_to_user(input, buf, wblock->req_buf_size)) {
877 		dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n",
878 			wblock->req_buf_size);
879 		ret = -EFAULT;
880 	}
881 
882 out_ioctl:
883 	mutex_unlock(&wblock->char_mutex);
884 	return ret;
885 }
886 
887 static const struct file_operations wmi_fops = {
888 	.owner		= THIS_MODULE,
889 	.read		= wmi_char_read,
890 	.open		= wmi_char_open,
891 	.unlocked_ioctl	= wmi_ioctl,
892 	.compat_ioctl	= wmi_ioctl,
893 };
894 
895 static int wmi_dev_probe(struct device *dev)
896 {
897 	struct wmi_block *wblock = dev_to_wblock(dev);
898 	struct wmi_driver *wdriver =
899 		container_of(dev->driver, struct wmi_driver, driver);
900 	int ret = 0;
901 	char *buf;
902 
903 	if (ACPI_FAILURE(wmi_method_enable(wblock, 1)))
904 		dev_warn(dev, "failed to enable device -- probing anyway\n");
905 
906 	if (wdriver->probe) {
907 		ret = wdriver->probe(dev_to_wdev(dev));
908 		if (ret != 0)
909 			goto probe_failure;
910 	}
911 
912 	/* driver wants a character device made */
913 	if (wdriver->filter_callback) {
914 		/* check that required buffer size declared by driver or MOF */
915 		if (!wblock->req_buf_size) {
916 			dev_err(&wblock->dev.dev,
917 				"Required buffer size not set\n");
918 			ret = -EINVAL;
919 			goto probe_failure;
920 		}
921 
922 		wblock->handler_data = kmalloc(wblock->req_buf_size,
923 					       GFP_KERNEL);
924 		if (!wblock->handler_data) {
925 			ret = -ENOMEM;
926 			goto probe_failure;
927 		}
928 
929 		buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name);
930 		if (!buf) {
931 			ret = -ENOMEM;
932 			goto probe_string_failure;
933 		}
934 		wblock->char_dev.minor = MISC_DYNAMIC_MINOR;
935 		wblock->char_dev.name = buf;
936 		wblock->char_dev.fops = &wmi_fops;
937 		wblock->char_dev.mode = 0444;
938 		ret = misc_register(&wblock->char_dev);
939 		if (ret) {
940 			dev_warn(dev, "failed to register char dev: %d\n", ret);
941 			ret = -ENOMEM;
942 			goto probe_misc_failure;
943 		}
944 	}
945 
946 	return 0;
947 
948 probe_misc_failure:
949 	kfree(buf);
950 probe_string_failure:
951 	kfree(wblock->handler_data);
952 probe_failure:
953 	if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
954 		dev_warn(dev, "failed to disable device\n");
955 	return ret;
956 }
957 
958 static int wmi_dev_remove(struct device *dev)
959 {
960 	struct wmi_block *wblock = dev_to_wblock(dev);
961 	struct wmi_driver *wdriver =
962 		container_of(dev->driver, struct wmi_driver, driver);
963 	int ret = 0;
964 
965 	if (wdriver->filter_callback) {
966 		misc_deregister(&wblock->char_dev);
967 		kfree(wblock->char_dev.name);
968 		kfree(wblock->handler_data);
969 	}
970 
971 	if (wdriver->remove)
972 		ret = wdriver->remove(dev_to_wdev(dev));
973 
974 	if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
975 		dev_warn(dev, "failed to disable device\n");
976 
977 	return ret;
978 }
979 
980 static struct class wmi_bus_class = {
981 	.name = "wmi_bus",
982 };
983 
984 static struct bus_type wmi_bus_type = {
985 	.name = "wmi",
986 	.dev_groups = wmi_groups,
987 	.match = wmi_dev_match,
988 	.uevent = wmi_dev_uevent,
989 	.probe = wmi_dev_probe,
990 	.remove = wmi_dev_remove,
991 };
992 
993 static const struct device_type wmi_type_event = {
994 	.name = "event",
995 	.groups = wmi_event_groups,
996 	.release = wmi_dev_release,
997 };
998 
999 static const struct device_type wmi_type_method = {
1000 	.name = "method",
1001 	.groups = wmi_method_groups,
1002 	.release = wmi_dev_release,
1003 };
1004 
1005 static const struct device_type wmi_type_data = {
1006 	.name = "data",
1007 	.groups = wmi_data_groups,
1008 	.release = wmi_dev_release,
1009 };
1010 
1011 static int wmi_create_device(struct device *wmi_bus_dev,
1012 			     const struct guid_block *gblock,
1013 			     struct wmi_block *wblock,
1014 			     struct acpi_device *device)
1015 {
1016 	struct acpi_device_info *info;
1017 	char method[5];
1018 	int result;
1019 
1020 	if (gblock->flags & ACPI_WMI_EVENT) {
1021 		wblock->dev.dev.type = &wmi_type_event;
1022 		goto out_init;
1023 	}
1024 
1025 	if (gblock->flags & ACPI_WMI_METHOD) {
1026 		wblock->dev.dev.type = &wmi_type_method;
1027 		mutex_init(&wblock->char_mutex);
1028 		goto out_init;
1029 	}
1030 
1031 	/*
1032 	 * Data Block Query Control Method (WQxx by convention) is
1033 	 * required per the WMI documentation. If it is not present,
1034 	 * we ignore this data block.
1035 	 */
1036 	strcpy(method, "WQ");
1037 	strncat(method, wblock->gblock.object_id, 2);
1038 	result = get_subobj_info(device->handle, method, &info);
1039 
1040 	if (result) {
1041 		dev_warn(wmi_bus_dev,
1042 			 "%s data block query control method not found\n",
1043 			 method);
1044 		return result;
1045 	}
1046 
1047 	wblock->dev.dev.type = &wmi_type_data;
1048 
1049 	/*
1050 	 * The Microsoft documentation specifically states:
1051 	 *
1052 	 *   Data blocks registered with only a single instance
1053 	 *   can ignore the parameter.
1054 	 *
1055 	 * ACPICA will get mad at us if we call the method with the wrong number
1056 	 * of arguments, so check what our method expects.  (On some Dell
1057 	 * laptops, WQxx may not be a method at all.)
1058 	 */
1059 	if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1060 		wblock->read_takes_no_args = true;
1061 
1062 	kfree(info);
1063 
1064 	strcpy(method, "WS");
1065 	strncat(method, wblock->gblock.object_id, 2);
1066 	result = get_subobj_info(device->handle, method, NULL);
1067 
1068 	if (result == 0)
1069 		wblock->dev.setable = true;
1070 
1071  out_init:
1072 	wblock->dev.dev.bus = &wmi_bus_type;
1073 	wblock->dev.dev.parent = wmi_bus_dev;
1074 
1075 	dev_set_name(&wblock->dev.dev, "%pUL", gblock->guid);
1076 
1077 	device_initialize(&wblock->dev.dev);
1078 
1079 	return 0;
1080 }
1081 
1082 static void wmi_free_devices(struct acpi_device *device)
1083 {
1084 	struct wmi_block *wblock, *next;
1085 
1086 	/* Delete devices for all the GUIDs */
1087 	list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1088 		if (wblock->acpi_device == device) {
1089 			list_del(&wblock->list);
1090 			device_unregister(&wblock->dev.dev);
1091 		}
1092 	}
1093 }
1094 
1095 static bool guid_already_parsed(struct acpi_device *device,
1096 				const u8 *guid)
1097 {
1098 	struct wmi_block *wblock;
1099 
1100 	list_for_each_entry(wblock, &wmi_block_list, list) {
1101 		if (memcmp(wblock->gblock.guid, guid, 16) == 0) {
1102 			/*
1103 			 * Because we historically didn't track the relationship
1104 			 * between GUIDs and ACPI nodes, we don't know whether
1105 			 * we need to suppress GUIDs that are unique on a
1106 			 * given node but duplicated across nodes.
1107 			 */
1108 			dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
1109 				 guid, dev_name(&wblock->acpi_device->dev));
1110 			return true;
1111 		}
1112 	}
1113 
1114 	return false;
1115 }
1116 
1117 /*
1118  * Parse the _WDG method for the GUID data blocks
1119  */
1120 static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
1121 {
1122 	struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1123 	const struct guid_block *gblock;
1124 	struct wmi_block *wblock, *next;
1125 	union acpi_object *obj;
1126 	acpi_status status;
1127 	int retval = 0;
1128 	u32 i, total;
1129 
1130 	status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1131 	if (ACPI_FAILURE(status))
1132 		return -ENXIO;
1133 
1134 	obj = (union acpi_object *) out.pointer;
1135 	if (!obj)
1136 		return -ENXIO;
1137 
1138 	if (obj->type != ACPI_TYPE_BUFFER) {
1139 		retval = -ENXIO;
1140 		goto out_free_pointer;
1141 	}
1142 
1143 	gblock = (const struct guid_block *)obj->buffer.pointer;
1144 	total = obj->buffer.length / sizeof(struct guid_block);
1145 
1146 	for (i = 0; i < total; i++) {
1147 		if (debug_dump_wdg)
1148 			wmi_dump_wdg(&gblock[i]);
1149 
1150 		/*
1151 		 * Some WMI devices, like those for nVidia hooks, have a
1152 		 * duplicate GUID. It's not clear what we should do in this
1153 		 * case yet, so for now, we'll just ignore the duplicate
1154 		 * for device creation.
1155 		 */
1156 		if (guid_already_parsed(device, gblock[i].guid))
1157 			continue;
1158 
1159 		wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
1160 		if (!wblock) {
1161 			retval = -ENOMEM;
1162 			break;
1163 		}
1164 
1165 		wblock->acpi_device = device;
1166 		wblock->gblock = gblock[i];
1167 
1168 		retval = wmi_create_device(wmi_bus_dev, &gblock[i], wblock, device);
1169 		if (retval) {
1170 			kfree(wblock);
1171 			continue;
1172 		}
1173 
1174 		list_add_tail(&wblock->list, &wmi_block_list);
1175 
1176 		if (debug_event) {
1177 			wblock->handler = wmi_notify_debug;
1178 			wmi_method_enable(wblock, 1);
1179 		}
1180 	}
1181 
1182 	/*
1183 	 * Now that all of the devices are created, add them to the
1184 	 * device tree and probe subdrivers.
1185 	 */
1186 	list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1187 		if (wblock->acpi_device != device)
1188 			continue;
1189 
1190 		retval = device_add(&wblock->dev.dev);
1191 		if (retval) {
1192 			dev_err(wmi_bus_dev, "failed to register %pUL\n",
1193 				wblock->gblock.guid);
1194 			if (debug_event)
1195 				wmi_method_enable(wblock, 0);
1196 			list_del(&wblock->list);
1197 			put_device(&wblock->dev.dev);
1198 		}
1199 	}
1200 
1201 out_free_pointer:
1202 	kfree(out.pointer);
1203 	return retval;
1204 }
1205 
1206 /*
1207  * WMI can have EmbeddedControl access regions. In which case, we just want to
1208  * hand these off to the EC driver.
1209  */
1210 static acpi_status
1211 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1212 		      u32 bits, u64 *value,
1213 		      void *handler_context, void *region_context)
1214 {
1215 	int result = 0, i = 0;
1216 	u8 temp = 0;
1217 
1218 	if ((address > 0xFF) || !value)
1219 		return AE_BAD_PARAMETER;
1220 
1221 	if (function != ACPI_READ && function != ACPI_WRITE)
1222 		return AE_BAD_PARAMETER;
1223 
1224 	if (bits != 8)
1225 		return AE_BAD_PARAMETER;
1226 
1227 	if (function == ACPI_READ) {
1228 		result = ec_read(address, &temp);
1229 		(*value) |= ((u64)temp) << i;
1230 	} else {
1231 		temp = 0xff & ((*value) >> i);
1232 		result = ec_write(address, temp);
1233 	}
1234 
1235 	switch (result) {
1236 	case -EINVAL:
1237 		return AE_BAD_PARAMETER;
1238 		break;
1239 	case -ENODEV:
1240 		return AE_NOT_FOUND;
1241 		break;
1242 	case -ETIME:
1243 		return AE_TIME;
1244 		break;
1245 	default:
1246 		return AE_OK;
1247 	}
1248 }
1249 
1250 static void acpi_wmi_notify_handler(acpi_handle handle, u32 event,
1251 				    void *context)
1252 {
1253 	struct guid_block *block;
1254 	struct wmi_block *wblock;
1255 	bool found_it = false;
1256 
1257 	list_for_each_entry(wblock, &wmi_block_list, list) {
1258 		block = &wblock->gblock;
1259 
1260 		if (wblock->acpi_device->handle == handle &&
1261 		    (block->flags & ACPI_WMI_EVENT) &&
1262 		    (block->notify_id == event))
1263 		{
1264 			found_it = true;
1265 			break;
1266 		}
1267 	}
1268 
1269 	if (!found_it)
1270 		return;
1271 
1272 	/* If a driver is bound, then notify the driver. */
1273 	if (wblock->dev.dev.driver) {
1274 		struct wmi_driver *driver;
1275 		struct acpi_object_list input;
1276 		union acpi_object params[1];
1277 		struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL };
1278 		acpi_status status;
1279 
1280 		driver = container_of(wblock->dev.dev.driver,
1281 				      struct wmi_driver, driver);
1282 
1283 		input.count = 1;
1284 		input.pointer = params;
1285 		params[0].type = ACPI_TYPE_INTEGER;
1286 		params[0].integer.value = event;
1287 
1288 		status = acpi_evaluate_object(wblock->acpi_device->handle,
1289 					      "_WED", &input, &evdata);
1290 		if (ACPI_FAILURE(status)) {
1291 			dev_warn(&wblock->dev.dev,
1292 				 "failed to get event data\n");
1293 			return;
1294 		}
1295 
1296 		if (driver->notify)
1297 			driver->notify(&wblock->dev,
1298 				       (union acpi_object *)evdata.pointer);
1299 
1300 		kfree(evdata.pointer);
1301 	} else if (wblock->handler) {
1302 		/* Legacy handler */
1303 		wblock->handler(event, wblock->handler_data);
1304 	}
1305 
1306 	if (debug_event) {
1307 		pr_info("DEBUG Event GUID: %pUL\n",
1308 			wblock->gblock.guid);
1309 	}
1310 
1311 	acpi_bus_generate_netlink_event(
1312 		wblock->acpi_device->pnp.device_class,
1313 		dev_name(&wblock->dev.dev),
1314 		event, 0);
1315 
1316 }
1317 
1318 static int acpi_wmi_remove(struct platform_device *device)
1319 {
1320 	struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev);
1321 
1322 	acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1323 				   acpi_wmi_notify_handler);
1324 	acpi_remove_address_space_handler(acpi_device->handle,
1325 				ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
1326 	wmi_free_devices(acpi_device);
1327 	device_destroy(&wmi_bus_class, MKDEV(0, 0));
1328 
1329 	return 0;
1330 }
1331 
1332 static int acpi_wmi_probe(struct platform_device *device)
1333 {
1334 	struct acpi_device *acpi_device;
1335 	struct device *wmi_bus_dev;
1336 	acpi_status status;
1337 	int error;
1338 
1339 	acpi_device = ACPI_COMPANION(&device->dev);
1340 	if (!acpi_device) {
1341 		dev_err(&device->dev, "ACPI companion is missing\n");
1342 		return -ENODEV;
1343 	}
1344 
1345 	status = acpi_install_address_space_handler(acpi_device->handle,
1346 						    ACPI_ADR_SPACE_EC,
1347 						    &acpi_wmi_ec_space_handler,
1348 						    NULL, NULL);
1349 	if (ACPI_FAILURE(status)) {
1350 		dev_err(&device->dev, "Error installing EC region handler\n");
1351 		return -ENODEV;
1352 	}
1353 
1354 	status = acpi_install_notify_handler(acpi_device->handle,
1355 					     ACPI_DEVICE_NOTIFY,
1356 					     acpi_wmi_notify_handler,
1357 					     NULL);
1358 	if (ACPI_FAILURE(status)) {
1359 		dev_err(&device->dev, "Error installing notify handler\n");
1360 		error = -ENODEV;
1361 		goto err_remove_ec_handler;
1362 	}
1363 
1364 	wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0),
1365 				    NULL, "wmi_bus-%s", dev_name(&device->dev));
1366 	if (IS_ERR(wmi_bus_dev)) {
1367 		error = PTR_ERR(wmi_bus_dev);
1368 		goto err_remove_notify_handler;
1369 	}
1370 	dev_set_drvdata(&device->dev, wmi_bus_dev);
1371 
1372 	error = parse_wdg(wmi_bus_dev, acpi_device);
1373 	if (error) {
1374 		pr_err("Failed to parse WDG method\n");
1375 		goto err_remove_busdev;
1376 	}
1377 
1378 	return 0;
1379 
1380 err_remove_busdev:
1381 	device_destroy(&wmi_bus_class, MKDEV(0, 0));
1382 
1383 err_remove_notify_handler:
1384 	acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1385 				   acpi_wmi_notify_handler);
1386 
1387 err_remove_ec_handler:
1388 	acpi_remove_address_space_handler(acpi_device->handle,
1389 					  ACPI_ADR_SPACE_EC,
1390 					  &acpi_wmi_ec_space_handler);
1391 
1392 	return error;
1393 }
1394 
1395 int __must_check __wmi_driver_register(struct wmi_driver *driver,
1396 				       struct module *owner)
1397 {
1398 	driver->driver.owner = owner;
1399 	driver->driver.bus = &wmi_bus_type;
1400 
1401 	return driver_register(&driver->driver);
1402 }
1403 EXPORT_SYMBOL(__wmi_driver_register);
1404 
1405 void wmi_driver_unregister(struct wmi_driver *driver)
1406 {
1407 	driver_unregister(&driver->driver);
1408 }
1409 EXPORT_SYMBOL(wmi_driver_unregister);
1410 
1411 static int __init acpi_wmi_init(void)
1412 {
1413 	int error;
1414 
1415 	if (acpi_disabled)
1416 		return -ENODEV;
1417 
1418 	error = class_register(&wmi_bus_class);
1419 	if (error)
1420 		return error;
1421 
1422 	error = bus_register(&wmi_bus_type);
1423 	if (error)
1424 		goto err_unreg_class;
1425 
1426 	error = platform_driver_register(&acpi_wmi_driver);
1427 	if (error) {
1428 		pr_err("Error loading mapper\n");
1429 		goto err_unreg_bus;
1430 	}
1431 
1432 	return 0;
1433 
1434 err_unreg_bus:
1435 	bus_unregister(&wmi_bus_type);
1436 
1437 err_unreg_class:
1438 	class_unregister(&wmi_bus_class);
1439 
1440 	return error;
1441 }
1442 
1443 static void __exit acpi_wmi_exit(void)
1444 {
1445 	platform_driver_unregister(&acpi_wmi_driver);
1446 	bus_unregister(&wmi_bus_type);
1447 	class_unregister(&wmi_bus_class);
1448 }
1449 
1450 subsys_initcall_sync(acpi_wmi_init);
1451 module_exit(acpi_wmi_exit);
1452