wmi.c 22.6 KB
Newer Older
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
/*
 *  ACPI-WMI mapping driver
 *
 *  Copyright (C) 2007-2008 Carlos Corbacho <carlos@strangeworlds.co.uk>
 *
 *  GUID parsing code from ldm.c is:
 *   Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
 *   Copyright (c) 2001-2007 Anton Altaparmakov
 *   Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or (at
 *  your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */

30
31
#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt

32
33
34
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/types.h>
35
#include <linux/device.h>
36
37
#include <linux/list.h>
#include <linux/acpi.h>
38
#include <linux/slab.h>
39
#include <linux/module.h>
40
41
42
43
44
45
46
47
48

ACPI_MODULE_NAME("wmi");
MODULE_AUTHOR("Carlos Corbacho");
MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
MODULE_LICENSE("GPL");

#define ACPI_WMI_CLASS "wmi"

static DEFINE_MUTEX(wmi_data_lock);
49
static LIST_HEAD(wmi_block_list);
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69

struct guid_block {
	char guid[16];
	union {
		char object_id[2];
		struct {
			unsigned char notify_id;
			unsigned char reserved;
		};
	};
	u8 instance_count;
	u8 flags;
};

struct wmi_block {
	struct list_head list;
	struct guid_block gblock;
	acpi_handle handle;
	wmi_notify_handler handler;
	void *handler_data;
70
	struct device dev;
71
72
73
74
75
76
77
78
79
80
81
82
};


/*
 * If the GUID data block is marked as expensive, we must enable and
 * explicitily disable data collection.
 */
#define ACPI_WMI_EXPENSIVE   0x1
#define ACPI_WMI_METHOD      0x2	/* GUID is a method */
#define ACPI_WMI_STRING      0x4	/* GUID takes & returns a string */
#define ACPI_WMI_EVENT       0x8	/* GUID is an event */

83
static bool debug_event;
84
85
86
87
module_param(debug_event, bool, 0444);
MODULE_PARM_DESC(debug_event,
		 "Log WMI Events [0/1]");

88
static bool debug_dump_wdg;
89
90
91
92
module_param(debug_dump_wdg, bool, 0444);
MODULE_PARM_DESC(debug_dump_wdg,
		 "Dump available WMI interfaces [0/1]");

93
static int acpi_wmi_remove(struct acpi_device *device);
94
static int acpi_wmi_add(struct acpi_device *device);
95
static void acpi_wmi_notify(struct acpi_device *device, u32 event);
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110

static const struct acpi_device_id wmi_device_ids[] = {
	{"PNP0C14", 0},
	{"pnp0c14", 0},
	{"", 0},
};
MODULE_DEVICE_TABLE(acpi, wmi_device_ids);

static struct acpi_driver acpi_wmi_driver = {
	.name = "wmi",
	.class = ACPI_WMI_CLASS,
	.ids = wmi_device_ids,
	.ops = {
		.add = acpi_wmi_add,
		.remove = acpi_wmi_remove,
111
		.notify = acpi_wmi_notify,
112
	},
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
};

/*
 * GUID parsing functions
 */

/**
 * wmi_parse_hexbyte - Convert a ASCII hex number to a byte
 * @src:  Pointer to at least 2 characters to convert.
 *
 * Convert a two character ASCII hex string to a number.
 *
 * Return:  0-255  Success, the byte was parsed correctly
 *          -1     Error, an invalid character was supplied
 */
static int wmi_parse_hexbyte(const u8 *src)
{
	int h;
131
	int value;
132
133

	/* high part */
134
135
	h = value = hex_to_bin(src[0]);
	if (value < 0)
136
137
138
		return -1;

	/* low part */
139
140
141
	value = hex_to_bin(src[1]);
	if (value >= 0)
		return (h << 4) | value;
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
	return -1;
}

/**
 * wmi_swap_bytes - Rearrange GUID bytes to match GUID binary
 * @src:   Memory block holding binary GUID (16 bytes)
 * @dest:  Memory block to hold byte swapped binary GUID (16 bytes)
 *
 * Byte swap a binary GUID to match it's real GUID value
 */
static void wmi_swap_bytes(u8 *src, u8 *dest)
{
	int i;

	for (i = 0; i <= 3; i++)
		memcpy(dest + i, src + (3 - i), 1);

	for (i = 0; i <= 1; i++)
		memcpy(dest + 4 + i, src + (5 - i), 1);

	for (i = 0; i <= 1; i++)
		memcpy(dest + 6 + i, src + (7 - i), 1);

	memcpy(dest + 8, src + 8, 8);
}

/**
 * wmi_parse_guid - Convert GUID from ASCII to binary
 * @src:   36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 * @dest:  Memory block to hold binary GUID (16 bytes)
 *
 * N.B. The GUID need not be NULL terminated.
 *
 * Return:  'true'   @dest contains binary GUID
 *          'false'  @dest contents are undefined
 */
static bool wmi_parse_guid(const u8 *src, u8 *dest)
{
	static const int size[] = { 4, 2, 2, 2, 6 };
	int i, j, v;

	if (src[8]  != '-' || src[13] != '-' ||
		src[18] != '-' || src[23] != '-')
		return false;

	for (j = 0; j < 5; j++, src++) {
		for (i = 0; i < size[j]; i++, src += 2, *dest++ = v) {
			v = wmi_parse_hexbyte(src);
			if (v < 0)
				return false;
		}
	}

	return true;
}

198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
/*
 * Convert a raw GUID to the ACII string representation
 */
static int wmi_gtoa(const char *in, char *out)
{
	int i;

	for (i = 3; i >= 0; i--)
		out += sprintf(out, "%02X", in[i] & 0xFF);

	out += sprintf(out, "-");
	out += sprintf(out, "%02X", in[5] & 0xFF);
	out += sprintf(out, "%02X", in[4] & 0xFF);
	out += sprintf(out, "-");
	out += sprintf(out, "%02X", in[7] & 0xFF);
	out += sprintf(out, "%02X", in[6] & 0xFF);
	out += sprintf(out, "-");
	out += sprintf(out, "%02X", in[8] & 0xFF);
	out += sprintf(out, "%02X", in[9] & 0xFF);
	out += sprintf(out, "-");

	for (i = 10; i <= 15; i++)
		out += sprintf(out, "%02X", in[i] & 0xFF);

222
	*out = '\0';
223
224
225
	return 0;
}

226
227
228
229
230
231
232
233
234
235
static bool find_guid(const char *guid_string, struct wmi_block **out)
{
	char tmp[16], guid_input[16];
	struct wmi_block *wblock;
	struct guid_block *block;
	struct list_head *p;

	wmi_parse_guid(guid_string, tmp);
	wmi_swap_bytes(tmp, guid_input);

236
	list_for_each(p, &wmi_block_list) {
237
238
239
240
241
242
243
244
245
246
247
248
		wblock = list_entry(p, struct wmi_block, list);
		block = &wblock->gblock;

		if (memcmp(block->guid, guid_input, 16) == 0) {
			if (out)
				*out = wblock;
			return 1;
		}
	}
	return 0;
}

249
250
251
252
253
254
255
256
257
258
259
static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable)
{
	struct guid_block *block = NULL;
	char method[5];
	acpi_status status;
	acpi_handle handle;

	block = &wblock->gblock;
	handle = wblock->handle;

	snprintf(method, 5, "WE%02X", block->notify_id);
260
	status = acpi_execute_simple_method(handle, method, enable);
261
262
263
264
265
266
267

	if (status != AE_OK && status != AE_NOT_FOUND)
		return status;
	else
		return AE_OK;
}

268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
/*
 * Exported WMI functions
 */
/**
 * wmi_evaluate_method - Evaluate a WMI method
 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 * @instance: Instance index
 * @method_id: Method ID to call
 * &in: Buffer containing input for the method call
 * &out: Empty buffer to return the method results
 *
 * Call an ACPI-WMI method
 */
acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
{
	struct guid_block *block = NULL;
	struct wmi_block *wblock = NULL;
	acpi_handle handle;
	acpi_status status;
	struct acpi_object_list input;
	union acpi_object params[3];
290
	char method[5] = "WM";
291
292

	if (!find_guid(guid_string, &wblock))
293
		return AE_ERROR;
294
295
296
297

	block = &wblock->gblock;
	handle = wblock->handle;

Al Viro's avatar
Al Viro committed
298
	if (!(block->flags & ACPI_WMI_METHOD))
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
		return AE_BAD_DATA;

	if (block->instance_count < instance)
		return AE_BAD_PARAMETER;

	input.count = 2;
	input.pointer = params;
	params[0].type = ACPI_TYPE_INTEGER;
	params[0].integer.value = instance;
	params[1].type = ACPI_TYPE_INTEGER;
	params[1].integer.value = method_id;

	if (in) {
		input.count = 3;

		if (block->flags & ACPI_WMI_STRING) {
			params[2].type = ACPI_TYPE_STRING;
		} else {
			params[2].type = ACPI_TYPE_BUFFER;
		}
		params[2].buffer.length = in->length;
		params[2].buffer.pointer = in->pointer;
	}

	strncat(method, block->object_id, 2);

	status = acpi_evaluate_object(handle, method, &input, out);

	return status;
}
EXPORT_SYMBOL_GPL(wmi_evaluate_method);

/**
 * wmi_query_block - Return contents of a WMI block
 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 * @instance: Instance index
 * &out: Empty buffer to return the contents of the data block to
 *
 * Return the contents of an ACPI-WMI data block to a buffer
 */
acpi_status wmi_query_block(const char *guid_string, u8 instance,
struct acpi_buffer *out)
{
	struct guid_block *block = NULL;
	struct wmi_block *wblock = NULL;
344
	acpi_handle handle;
345
	acpi_status status, wc_status = AE_ERROR;
346
347
	struct acpi_object_list input;
	union acpi_object wq_params[1];
348
349
	char method[5];
	char wc_method[5] = "WC";
350
351
352
353
354

	if (!guid_string || !out)
		return AE_BAD_PARAMETER;

	if (!find_guid(guid_string, &wblock))
355
		return AE_ERROR;
356
357
358
359
360
361
362
363
364

	block = &wblock->gblock;
	handle = wblock->handle;

	if (block->instance_count < instance)
		return AE_BAD_PARAMETER;

	/* Check GUID is a data block */
	if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
365
		return AE_ERROR;
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383

	input.count = 1;
	input.pointer = wq_params;
	wq_params[0].type = ACPI_TYPE_INTEGER;
	wq_params[0].integer.value = instance;

	/*
	 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
	 * enable collection.
	 */
	if (block->flags & ACPI_WMI_EXPENSIVE) {
		strncat(wc_method, block->object_id, 2);

		/*
		 * Some GUIDs break the specification by declaring themselves
		 * expensive, but have no corresponding WCxx method. So we
		 * should not fail if this happens.
		 */
384
		if (acpi_has_method(handle, wc_method))
385
386
			wc_status = acpi_execute_simple_method(handle,
								wc_method, 1);
387
388
389
390
391
	}

	strcpy(method, "WQ");
	strncat(method, block->object_id, 2);

392
	status = acpi_evaluate_object(handle, method, &input, out);
393
394
395
396
397

	/*
	 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
	 * the WQxx method failed - we should disable collection anyway.
	 */
398
	if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
399
		status = acpi_execute_simple_method(handle, wc_method, 0);
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
	}

	return status;
}
EXPORT_SYMBOL_GPL(wmi_query_block);

/**
 * wmi_set_block - Write to a WMI block
 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 * @instance: Instance index
 * &in: Buffer containing new values for the data block
 *
 * Write the contents of the input buffer to an ACPI-WMI data block
 */
acpi_status wmi_set_block(const char *guid_string, u8 instance,
const struct acpi_buffer *in)
{
	struct guid_block *block = NULL;
	struct wmi_block *wblock = NULL;
	acpi_handle handle;
	struct acpi_object_list input;
	union acpi_object params[2];
422
	char method[5] = "WS";
423
424
425
426
427

	if (!guid_string || !in)
		return AE_BAD_DATA;

	if (!find_guid(guid_string, &wblock))
428
		return AE_ERROR;
429
430
431
432
433
434
435
436
437

	block = &wblock->gblock;
	handle = wblock->handle;

	if (block->instance_count < instance)
		return AE_BAD_PARAMETER;

	/* Check GUID is a data block */
	if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
438
		return AE_ERROR;
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458

	input.count = 2;
	input.pointer = params;
	params[0].type = ACPI_TYPE_INTEGER;
	params[0].integer.value = instance;

	if (block->flags & ACPI_WMI_STRING) {
		params[1].type = ACPI_TYPE_STRING;
	} else {
		params[1].type = ACPI_TYPE_BUFFER;
	}
	params[1].buffer.length = in->length;
	params[1].buffer.pointer = in->pointer;

	strncat(method, block->object_id, 2);

	return acpi_evaluate_object(handle, method, &input, NULL);
}
EXPORT_SYMBOL_GPL(wmi_set_block);

459
static void wmi_dump_wdg(const struct guid_block *g)
460
461
462
463
{
	char guid_string[37];

	wmi_gtoa(g->guid, guid_string);
464
465
466
467
468
469

	pr_info("%s:\n", guid_string);
	pr_info("\tobject_id: %c%c\n", g->object_id[0], g->object_id[1]);
	pr_info("\tnotify_id: %02X\n", g->notify_id);
	pr_info("\treserved: %02X\n", g->reserved);
	pr_info("\tinstance_count: %d\n", g->instance_count);
470
	pr_info("\tflags: %#x", g->flags);
471
472
	if (g->flags) {
		if (g->flags & ACPI_WMI_EXPENSIVE)
473
			pr_cont(" ACPI_WMI_EXPENSIVE");
474
		if (g->flags & ACPI_WMI_METHOD)
475
			pr_cont(" ACPI_WMI_METHOD");
476
		if (g->flags & ACPI_WMI_STRING)
477
			pr_cont(" ACPI_WMI_STRING");
478
		if (g->flags & ACPI_WMI_EVENT)
479
			pr_cont(" ACPI_WMI_EVENT");
480
	}
481
	pr_cont("\n");
482
483
484

}

485
486
487
488
static void wmi_notify_debug(u32 value, void *context)
{
	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
	union acpi_object *obj;
489
	acpi_status status;
490

491
492
	status = wmi_get_event_data(value, &response);
	if (status != AE_OK) {
493
		pr_info("bad event status 0x%x\n", status);
494
495
		return;
	}
496
497
498
499
500
501

	obj = (union acpi_object *)response.pointer;

	if (!obj)
		return;

502
	pr_info("DEBUG Event ");
503
504
	switch(obj->type) {
	case ACPI_TYPE_BUFFER:
505
		pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
506
507
		break;
	case ACPI_TYPE_STRING:
508
		pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
509
510
		break;
	case ACPI_TYPE_INTEGER:
511
		pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
512
513
		break;
	case ACPI_TYPE_PACKAGE:
514
		pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
515
516
		break;
	default:
517
		pr_cont("object type 0x%X\n", obj->type);
518
	}
519
	kfree(obj);
520
521
}

522
523
524
525
526
527
528
529
530
531
532
/**
 * wmi_install_notify_handler - Register handler for WMI events
 * @handler: Function to handle notifications
 * @data: Data to be returned to handler when event is fired
 *
 * Register a handler for events sent to the ACPI-WMI mapper device.
 */
acpi_status wmi_install_notify_handler(const char *guid,
wmi_notify_handler handler, void *data)
{
	struct wmi_block *block;
533
534
535
	acpi_status status = AE_NOT_EXIST;
	char tmp[16], guid_input[16];
	struct list_head *p;
536
537
538
539

	if (!guid || !handler)
		return AE_BAD_PARAMETER;

540
541
	wmi_parse_guid(guid, tmp);
	wmi_swap_bytes(tmp, guid_input);
542

543
544
545
546
547
548
549
550
	list_for_each(p, &wmi_block_list) {
		acpi_status wmi_status;
		block = list_entry(p, struct wmi_block, list);

		if (memcmp(block->gblock.guid, guid_input, 16) == 0) {
			if (block->handler &&
			    block->handler != wmi_notify_debug)
				return AE_ALREADY_ACQUIRED;
551

552
553
			block->handler = handler;
			block->handler_data = data;
554

555
556
557
558
559
560
			wmi_status = wmi_method_enable(block, 1);
			if ((wmi_status != AE_OK) ||
			    ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
				status = wmi_status;
		}
	}
561
562

	return status;
563
564
565
566
567
568
569
570
571
572
573
}
EXPORT_SYMBOL_GPL(wmi_install_notify_handler);

/**
 * wmi_uninstall_notify_handler - Unregister handler for WMI events
 *
 * Unregister handler for events sent to the ACPI-WMI mapper device.
 */
acpi_status wmi_remove_notify_handler(const char *guid)
{
	struct wmi_block *block;
574
575
576
	acpi_status status = AE_NOT_EXIST;
	char tmp[16], guid_input[16];
	struct list_head *p;
577
578
579
580

	if (!guid)
		return AE_BAD_PARAMETER;

581
582
	wmi_parse_guid(guid, tmp);
	wmi_swap_bytes(tmp, guid_input);
583

584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
	list_for_each(p, &wmi_block_list) {
		acpi_status wmi_status;
		block = list_entry(p, struct wmi_block, list);

		if (memcmp(block->gblock.guid, guid_input, 16) == 0) {
			if (!block->handler ||
			    block->handler == wmi_notify_debug)
				return AE_NULL_ENTRY;

			if (debug_event) {
				block->handler = wmi_notify_debug;
				status = AE_OK;
			} else {
				wmi_status = wmi_method_enable(block, 0);
				block->handler = NULL;
				block->handler_data = NULL;
				if ((wmi_status != AE_OK) ||
				    ((wmi_status == AE_OK) &&
				     (status == AE_NOT_EXIST)))
					status = wmi_status;
			}
		}
606
	}
607

608
	return status;
609
610
611
612
613
614
}
EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);

/**
 * wmi_get_event_data - Get WMI data associated with an event
 *
615
616
 * @event: Event to find
 * @out: Buffer to hold event data. out->pointer should be freed with kfree()
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
 *
 * Returns extra data associated with an event in WMI.
 */
acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
{
	struct acpi_object_list input;
	union acpi_object params[1];
	struct guid_block *gblock;
	struct wmi_block *wblock;
	struct list_head *p;

	input.count = 1;
	input.pointer = params;
	params[0].type = ACPI_TYPE_INTEGER;
	params[0].integer.value = event;

633
	list_for_each(p, &wmi_block_list) {
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
		wblock = list_entry(p, struct wmi_block, list);
		gblock = &wblock->gblock;

		if ((gblock->flags & ACPI_WMI_EVENT) &&
			(gblock->notify_id == event))
			return acpi_evaluate_object(wblock->handle, "_WED",
				&input, out);
	}

	return AE_NOT_FOUND;
}
EXPORT_SYMBOL_GPL(wmi_get_event_data);

/**
 * wmi_has_guid - Check if a GUID is available
 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 *
 * Check if a given GUID is defined by _WDG
 */
bool wmi_has_guid(const char *guid_string)
{
	return find_guid(guid_string, NULL);
}
EXPORT_SYMBOL_GPL(wmi_has_guid);

659
660
661
/*
 * sysfs interface
 */
662
static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
663
664
665
666
667
668
			     char *buf)
{
	char guid_string[37];
	struct wmi_block *wblock;

	wblock = dev_get_drvdata(dev);
669
670
671
672
	if (!wblock) {
		strcat(buf, "\n");
		return strlen(buf);
	}
673
674
675
676
677

	wmi_gtoa(wblock->gblock.guid, guid_string);

	return sprintf(buf, "wmi:%s\n", guid_string);
}
678
static DEVICE_ATTR_RO(modalias);
679

680
681
682
static struct attribute *wmi_attrs[] = {
	&dev_attr_modalias.attr,
	NULL,
683
};
684
ATTRIBUTE_GROUPS(wmi);
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709

static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
{
	char guid_string[37];

	struct wmi_block *wblock;

	if (add_uevent_var(env, "MODALIAS="))
		return -ENOMEM;

	wblock = dev_get_drvdata(dev);
	if (!wblock)
		return -ENOMEM;

	wmi_gtoa(wblock->gblock.guid, guid_string);

	strcpy(&env->buf[env->buflen - 1], "wmi:");
	memcpy(&env->buf[env->buflen - 1 + 4], guid_string, 36);
	env->buflen += 40;

	return 0;
}

static void wmi_dev_free(struct device *dev)
{
710
711
712
	struct wmi_block *wmi_block = container_of(dev, struct wmi_block, dev);

	kfree(wmi_block);
713
714
715
716
717
718
}

static struct class wmi_class = {
	.name = "wmi",
	.dev_release = wmi_dev_free,
	.dev_uevent = wmi_dev_uevent,
719
	.dev_groups = wmi_groups,
720
721
};

722
723
static int wmi_create_device(const struct guid_block *gblock,
			     struct wmi_block *wblock, acpi_handle handle)
724
{
725
	char guid_string[37];
726

727
	wblock->dev.class = &wmi_class;
728

729
	wmi_gtoa(gblock->guid, guid_string);
730
	dev_set_name(&wblock->dev, "%s", guid_string);
731

732
	dev_set_drvdata(&wblock->dev, wblock);
733

734
	return device_register(&wblock->dev);
735
736
}

737
static void wmi_free_devices(void)
738
{
739
	struct wmi_block *wblock, *next;
740
741

	/* Delete devices for all the GUIDs */
742
743
	list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
		list_del(&wblock->list);
744
745
		if (wblock->dev.class)
			device_unregister(&wblock->dev);
746
747
748
		else
			kfree(wblock);
	}
749
750
}

751
752
753
754
static bool guid_already_parsed(const char *guid_string)
{
	struct wmi_block *wblock;

755
	list_for_each_entry(wblock, &wmi_block_list, list)
756
		if (memcmp(wblock->gblock.guid, guid_string, 16) == 0)
757
758
			return true;

759
	return false;
760
761
}

762
763
764
/*
 * Parse the _WDG method for the GUID data blocks
 */
765
static int parse_wdg(acpi_handle handle)
766
767
768
{
	struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
	union acpi_object *obj;
769
	const struct guid_block *gblock;
770
771
	struct wmi_block *wblock;
	acpi_status status;
772
	int retval;
773
774
775
776
	u32 i, total;

	status = acpi_evaluate_object(handle, "_WDG", NULL, &out);
	if (ACPI_FAILURE(status))
777
		return -ENXIO;
778
779

	obj = (union acpi_object *) out.pointer;
780
	if (!obj)
781
		return -ENXIO;
782

783
	if (obj->type != ACPI_TYPE_BUFFER) {
784
		retval = -ENXIO;
785
786
		goto out_free_pointer;
	}
787

788
	gblock = (const struct guid_block *)obj->buffer.pointer;
789
790
791
	total = obj->buffer.length / sizeof(struct guid_block);

	for (i = 0; i < total; i++) {
792
793
794
795
796
		if (debug_dump_wdg)
			wmi_dump_wdg(&gblock[i]);

		wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
		if (!wblock)
797
			return -ENOMEM;
798
799
800
801

		wblock->handle = handle;
		wblock->gblock = gblock[i];

802
803
804
		/*
		  Some WMI devices, like those for nVidia hooks, have a
		  duplicate GUID. It's not clear what we should do in this
805
806
		  case yet, so for now, we'll just ignore the duplicate
		  for device creation.
807
		*/
808
809
810
811
		if (!guid_already_parsed(gblock[i].guid)) {
			retval = wmi_create_device(&gblock[i], wblock, handle);
			if (retval) {
				wmi_free_devices();
812
				goto out_free_pointer;
813
			}
814
		}
815

816
		list_add_tail(&wblock->list, &wmi_block_list);
817

818
819
		if (debug_event) {
			wblock->handler = wmi_notify_debug;
820
			wmi_method_enable(wblock, 1);
821
		}
822
823
	}

824
825
	retval = 0;

Axel Lin's avatar
Axel Lin committed
826
827
out_free_pointer:
	kfree(out.pointer);
828

829
	return retval;
830
831
832
833
834
835
836
837
}

/*
 * WMI can have EmbeddedControl access regions. In which case, we just want to
 * hand these off to the EC driver.
 */
static acpi_status
acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
Lin Ming's avatar
Lin Ming committed
838
		      u32 bits, u64 *value,
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
		      void *handler_context, void *region_context)
{
	int result = 0, i = 0;
	u8 temp = 0;

	if ((address > 0xFF) || !value)
		return AE_BAD_PARAMETER;

	if (function != ACPI_READ && function != ACPI_WRITE)
		return AE_BAD_PARAMETER;

	if (bits != 8)
		return AE_BAD_PARAMETER;

	if (function == ACPI_READ) {
		result = ec_read(address, &temp);
Lin Ming's avatar
Lin Ming committed
855
		(*value) |= ((u64)temp) << i;
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
	} else {
		temp = 0xff & ((*value) >> i);
		result = ec_write(address, temp);
	}

	switch (result) {
	case -EINVAL:
		return AE_BAD_PARAMETER;
		break;
	case -ENODEV:
		return AE_NOT_FOUND;
		break;
	case -ETIME:
		return AE_TIME;
		break;
	default:
		return AE_OK;
	}
}

876
static void acpi_wmi_notify(struct acpi_device *device, u32 event)
877
878
879
880
{
	struct guid_block *block;
	struct wmi_block *wblock;
	struct list_head *p;
881
	char guid_string[37];
882

883
	list_for_each(p, &wmi_block_list) {
884
885
886
887
888
889
890
		wblock = list_entry(p, struct wmi_block, list);
		block = &wblock->gblock;

		if ((block->flags & ACPI_WMI_EVENT) &&
			(block->notify_id == event)) {
			if (wblock->handler)
				wblock->handler(event, wblock->handler_data);
891
892
			if (debug_event) {
				wmi_gtoa(wblock->gblock.guid, guid_string);
893
				pr_info("DEBUG Event GUID: %s\n", guid_string);
894
			}
895
896

			acpi_bus_generate_netlink_event(
897
				device->pnp.device_class, dev_name(&device->dev),
898
899
900
901
902
903
				event, 0);
			break;
		}
	}
}

904
static int acpi_wmi_remove(struct acpi_device *device)
905
906
907
{
	acpi_remove_address_space_handler(device->handle,
				ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
908
	wmi_free_devices();
909
910
911
912

	return 0;
}

913
static int acpi_wmi_add(struct acpi_device *device)
914
915
{
	acpi_status status;
916
	int error;
917
918
919
920
921

	status = acpi_install_address_space_handler(device->handle,
						    ACPI_ADR_SPACE_EC,
						    &acpi_wmi_ec_space_handler,
						    NULL, NULL);
922
	if (ACPI_FAILURE(status)) {
923
		pr_err("Error installing EC region handler\n");
924
		return -ENODEV;
925
	}
926

927
928
	error = parse_wdg(device->handle);
	if (error) {
929
930
931
		acpi_remove_address_space_handler(device->handle,
						  ACPI_ADR_SPACE_EC,
						  &acpi_wmi_ec_space_handler);
932
		pr_err("Failed to parse WDG method\n");
933
		return error;
934
935
	}

936
	return 0;
937
938
939
940
}

static int __init acpi_wmi_init(void)
{
941
	int error;
942
943
944
945

	if (acpi_disabled)
		return -ENODEV;

946
947
948
	error = class_register(&wmi_class);
	if (error)
		return error;
949

950
951
952
953
954
	error = acpi_bus_register_driver(&acpi_wmi_driver);
	if (error) {
		pr_err("Error loading mapper\n");
		class_unregister(&wmi_class);
		return error;
955
956
	}

957
958
	pr_info("Mapper loaded\n");
	return 0;
959
960
961
962
963
}

static void __exit acpi_wmi_exit(void)
{
	acpi_bus_unregister_driver(&acpi_wmi_driver);
964
	class_unregister(&wmi_class);
965

966
	pr_info("Mapper unloaded\n");
967
968
969
970
}

subsys_initcall(acpi_wmi_init);
module_exit(acpi_wmi_exit);