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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  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
12  *
13  *  This program is free software; you can redistribute it and/or modify
14  *  it under the terms of the GNU General Public License as published by
15  *  the Free Software Foundation; either version 2 of the License, or (at
16  *  your option) any later version.
17  *
18  *  This program is distributed in the hope that it will be useful, but
19  *  WITHOUT ANY WARRANTY; without even the implied warranty of
20  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
21  *  General Public License for more details.
22  *
23  *  You should have received a copy of the GNU General Public License along
24  *  with this program; if not, write to the Free Software Foundation, Inc.,
25  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
26  *
27  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
28  */
29 
30 #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
31 
32 #include <linux/kernel.h>
33 #include <linux/init.h>
34 #include <linux/types.h>
35 #include <linux/device.h>
36 #include <linux/list.h>
37 #include <linux/acpi.h>
38 #include <linux/slab.h>
39 #include <linux/module.h>
40 #include <acpi/acpi_bus.h>
41 #include <acpi/acpi_drivers.h>
42 
43 ACPI_MODULE_NAME("wmi");
44 MODULE_AUTHOR("Carlos Corbacho");
45 MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
46 MODULE_LICENSE("GPL");
47 
48 #define ACPI_WMI_CLASS "wmi"
49 
50 static DEFINE_MUTEX(wmi_data_lock);
51 static LIST_HEAD(wmi_block_list);
52 
53 struct guid_block {
54 	char guid[16];
55 	union {
56 		char object_id[2];
57 		struct {
58 			unsigned char notify_id;
59 			unsigned char reserved;
60 		};
61 	};
62 	u8 instance_count;
63 	u8 flags;
64 };
65 
66 struct wmi_block {
67 	struct list_head list;
68 	struct guid_block gblock;
69 	acpi_handle handle;
70 	wmi_notify_handler handler;
71 	void *handler_data;
72 	struct device dev;
73 };
74 
75 
76 /*
77  * If the GUID data block is marked as expensive, we must enable and
78  * explicitily disable data collection.
79  */
80 #define ACPI_WMI_EXPENSIVE   0x1
81 #define ACPI_WMI_METHOD      0x2	/* GUID is a method */
82 #define ACPI_WMI_STRING      0x4	/* GUID takes & returns a string */
83 #define ACPI_WMI_EVENT       0x8	/* GUID is an event */
84 
85 static bool debug_event;
86 module_param(debug_event, bool, 0444);
87 MODULE_PARM_DESC(debug_event,
88 		 "Log WMI Events [0/1]");
89 
90 static bool debug_dump_wdg;
91 module_param(debug_dump_wdg, bool, 0444);
92 MODULE_PARM_DESC(debug_dump_wdg,
93 		 "Dump available WMI interfaces [0/1]");
94 
95 static int acpi_wmi_remove(struct acpi_device *device);
96 static int acpi_wmi_add(struct acpi_device *device);
97 static void acpi_wmi_notify(struct acpi_device *device, u32 event);
98 
99 static const struct acpi_device_id wmi_device_ids[] = {
100 	{"PNP0C14", 0},
101 	{"pnp0c14", 0},
102 	{"", 0},
103 };
104 MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
105 
106 static struct acpi_driver acpi_wmi_driver = {
107 	.name = "wmi",
108 	.class = ACPI_WMI_CLASS,
109 	.ids = wmi_device_ids,
110 	.ops = {
111 		.add = acpi_wmi_add,
112 		.remove = acpi_wmi_remove,
113 		.notify = acpi_wmi_notify,
114 	},
115 };
116 
117 /*
118  * GUID parsing functions
119  */
120 
121 /**
122  * wmi_parse_hexbyte - Convert a ASCII hex number to a byte
123  * @src:  Pointer to at least 2 characters to convert.
124  *
125  * Convert a two character ASCII hex string to a number.
126  *
127  * Return:  0-255  Success, the byte was parsed correctly
128  *          -1     Error, an invalid character was supplied
129  */
wmi_parse_hexbyte(const u8 * src)130 static int wmi_parse_hexbyte(const u8 *src)
131 {
132 	int h;
133 	int value;
134 
135 	/* high part */
136 	h = value = hex_to_bin(src[0]);
137 	if (value < 0)
138 		return -1;
139 
140 	/* low part */
141 	value = hex_to_bin(src[1]);
142 	if (value >= 0)
143 		return (h << 4) | value;
144 	return -1;
145 }
146 
147 /**
148  * wmi_swap_bytes - Rearrange GUID bytes to match GUID binary
149  * @src:   Memory block holding binary GUID (16 bytes)
150  * @dest:  Memory block to hold byte swapped binary GUID (16 bytes)
151  *
152  * Byte swap a binary GUID to match it's real GUID value
153  */
wmi_swap_bytes(u8 * src,u8 * dest)154 static void wmi_swap_bytes(u8 *src, u8 *dest)
155 {
156 	int i;
157 
158 	for (i = 0; i <= 3; i++)
159 		memcpy(dest + i, src + (3 - i), 1);
160 
161 	for (i = 0; i <= 1; i++)
162 		memcpy(dest + 4 + i, src + (5 - i), 1);
163 
164 	for (i = 0; i <= 1; i++)
165 		memcpy(dest + 6 + i, src + (7 - i), 1);
166 
167 	memcpy(dest + 8, src + 8, 8);
168 }
169 
170 /**
171  * wmi_parse_guid - Convert GUID from ASCII to binary
172  * @src:   36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
173  * @dest:  Memory block to hold binary GUID (16 bytes)
174  *
175  * N.B. The GUID need not be NULL terminated.
176  *
177  * Return:  'true'   @dest contains binary GUID
178  *          'false'  @dest contents are undefined
179  */
wmi_parse_guid(const u8 * src,u8 * dest)180 static bool wmi_parse_guid(const u8 *src, u8 *dest)
181 {
182 	static const int size[] = { 4, 2, 2, 2, 6 };
183 	int i, j, v;
184 
185 	if (src[8]  != '-' || src[13] != '-' ||
186 		src[18] != '-' || src[23] != '-')
187 		return false;
188 
189 	for (j = 0; j < 5; j++, src++) {
190 		for (i = 0; i < size[j]; i++, src += 2, *dest++ = v) {
191 			v = wmi_parse_hexbyte(src);
192 			if (v < 0)
193 				return false;
194 		}
195 	}
196 
197 	return true;
198 }
199 
200 /*
201  * Convert a raw GUID to the ACII string representation
202  */
wmi_gtoa(const char * in,char * out)203 static int wmi_gtoa(const char *in, char *out)
204 {
205 	int i;
206 
207 	for (i = 3; i >= 0; i--)
208 		out += sprintf(out, "%02X", in[i] & 0xFF);
209 
210 	out += sprintf(out, "-");
211 	out += sprintf(out, "%02X", in[5] & 0xFF);
212 	out += sprintf(out, "%02X", in[4] & 0xFF);
213 	out += sprintf(out, "-");
214 	out += sprintf(out, "%02X", in[7] & 0xFF);
215 	out += sprintf(out, "%02X", in[6] & 0xFF);
216 	out += sprintf(out, "-");
217 	out += sprintf(out, "%02X", in[8] & 0xFF);
218 	out += sprintf(out, "%02X", in[9] & 0xFF);
219 	out += sprintf(out, "-");
220 
221 	for (i = 10; i <= 15; i++)
222 		out += sprintf(out, "%02X", in[i] & 0xFF);
223 
224 	*out = '\0';
225 	return 0;
226 }
227 
find_guid(const char * guid_string,struct wmi_block ** out)228 static bool find_guid(const char *guid_string, struct wmi_block **out)
229 {
230 	char tmp[16], guid_input[16];
231 	struct wmi_block *wblock;
232 	struct guid_block *block;
233 	struct list_head *p;
234 
235 	wmi_parse_guid(guid_string, tmp);
236 	wmi_swap_bytes(tmp, guid_input);
237 
238 	list_for_each(p, &wmi_block_list) {
239 		wblock = list_entry(p, struct wmi_block, list);
240 		block = &wblock->gblock;
241 
242 		if (memcmp(block->guid, guid_input, 16) == 0) {
243 			if (out)
244 				*out = wblock;
245 			return 1;
246 		}
247 	}
248 	return 0;
249 }
250 
wmi_method_enable(struct wmi_block * wblock,int enable)251 static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable)
252 {
253 	struct guid_block *block = NULL;
254 	char method[5];
255 	struct acpi_object_list input;
256 	union acpi_object params[1];
257 	acpi_status status;
258 	acpi_handle handle;
259 
260 	block = &wblock->gblock;
261 	handle = wblock->handle;
262 
263 	if (!block)
264 		return AE_NOT_EXIST;
265 
266 	input.count = 1;
267 	input.pointer = params;
268 	params[0].type = ACPI_TYPE_INTEGER;
269 	params[0].integer.value = enable;
270 
271 	snprintf(method, 5, "WE%02X", block->notify_id);
272 	status = acpi_evaluate_object(handle, method, &input, NULL);
273 
274 	if (status != AE_OK && status != AE_NOT_FOUND)
275 		return status;
276 	else
277 		return AE_OK;
278 }
279 
280 /*
281  * Exported WMI functions
282  */
283 /**
284  * wmi_evaluate_method - Evaluate a WMI method
285  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
286  * @instance: Instance index
287  * @method_id: Method ID to call
288  * &in: Buffer containing input for the method call
289  * &out: Empty buffer to return the method results
290  *
291  * Call an ACPI-WMI method
292  */
wmi_evaluate_method(const char * guid_string,u8 instance,u32 method_id,const struct acpi_buffer * in,struct acpi_buffer * out)293 acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
294 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
295 {
296 	struct guid_block *block = NULL;
297 	struct wmi_block *wblock = NULL;
298 	acpi_handle handle;
299 	acpi_status status;
300 	struct acpi_object_list input;
301 	union acpi_object params[3];
302 	char method[5] = "WM";
303 
304 	if (!find_guid(guid_string, &wblock))
305 		return AE_ERROR;
306 
307 	block = &wblock->gblock;
308 	handle = wblock->handle;
309 
310 	if (!(block->flags & ACPI_WMI_METHOD))
311 		return AE_BAD_DATA;
312 
313 	if (block->instance_count < instance)
314 		return AE_BAD_PARAMETER;
315 
316 	input.count = 2;
317 	input.pointer = params;
318 	params[0].type = ACPI_TYPE_INTEGER;
319 	params[0].integer.value = instance;
320 	params[1].type = ACPI_TYPE_INTEGER;
321 	params[1].integer.value = method_id;
322 
323 	if (in) {
324 		input.count = 3;
325 
326 		if (block->flags & ACPI_WMI_STRING) {
327 			params[2].type = ACPI_TYPE_STRING;
328 		} else {
329 			params[2].type = ACPI_TYPE_BUFFER;
330 		}
331 		params[2].buffer.length = in->length;
332 		params[2].buffer.pointer = in->pointer;
333 	}
334 
335 	strncat(method, block->object_id, 2);
336 
337 	status = acpi_evaluate_object(handle, method, &input, out);
338 
339 	return status;
340 }
341 EXPORT_SYMBOL_GPL(wmi_evaluate_method);
342 
343 /**
344  * wmi_query_block - Return contents of a WMI block
345  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
346  * @instance: Instance index
347  * &out: Empty buffer to return the contents of the data block to
348  *
349  * Return the contents of an ACPI-WMI data block to a buffer
350  */
wmi_query_block(const char * guid_string,u8 instance,struct acpi_buffer * out)351 acpi_status wmi_query_block(const char *guid_string, u8 instance,
352 struct acpi_buffer *out)
353 {
354 	struct guid_block *block = NULL;
355 	struct wmi_block *wblock = NULL;
356 	acpi_handle handle, wc_handle;
357 	acpi_status status, wc_status = AE_ERROR;
358 	struct acpi_object_list input, wc_input;
359 	union acpi_object wc_params[1], wq_params[1];
360 	char method[5];
361 	char wc_method[5] = "WC";
362 
363 	if (!guid_string || !out)
364 		return AE_BAD_PARAMETER;
365 
366 	if (!find_guid(guid_string, &wblock))
367 		return AE_ERROR;
368 
369 	block = &wblock->gblock;
370 	handle = wblock->handle;
371 
372 	if (block->instance_count < instance)
373 		return AE_BAD_PARAMETER;
374 
375 	/* Check GUID is a data block */
376 	if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
377 		return AE_ERROR;
378 
379 	input.count = 1;
380 	input.pointer = wq_params;
381 	wq_params[0].type = ACPI_TYPE_INTEGER;
382 	wq_params[0].integer.value = instance;
383 
384 	/*
385 	 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
386 	 * enable collection.
387 	 */
388 	if (block->flags & ACPI_WMI_EXPENSIVE) {
389 		wc_input.count = 1;
390 		wc_input.pointer = wc_params;
391 		wc_params[0].type = ACPI_TYPE_INTEGER;
392 		wc_params[0].integer.value = 1;
393 
394 		strncat(wc_method, block->object_id, 2);
395 
396 		/*
397 		 * Some GUIDs break the specification by declaring themselves
398 		 * expensive, but have no corresponding WCxx method. So we
399 		 * should not fail if this happens.
400 		 */
401 		wc_status = acpi_get_handle(handle, wc_method, &wc_handle);
402 		if (ACPI_SUCCESS(wc_status))
403 			wc_status = acpi_evaluate_object(handle, wc_method,
404 				&wc_input, NULL);
405 	}
406 
407 	strcpy(method, "WQ");
408 	strncat(method, block->object_id, 2);
409 
410 	status = acpi_evaluate_object(handle, method, &input, out);
411 
412 	/*
413 	 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
414 	 * the WQxx method failed - we should disable collection anyway.
415 	 */
416 	if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
417 		wc_params[0].integer.value = 0;
418 		status = acpi_evaluate_object(handle,
419 		wc_method, &wc_input, NULL);
420 	}
421 
422 	return status;
423 }
424 EXPORT_SYMBOL_GPL(wmi_query_block);
425 
426 /**
427  * wmi_set_block - Write to a WMI block
428  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
429  * @instance: Instance index
430  * &in: Buffer containing new values for the data block
431  *
432  * Write the contents of the input buffer to an ACPI-WMI data block
433  */
wmi_set_block(const char * guid_string,u8 instance,const struct acpi_buffer * in)434 acpi_status wmi_set_block(const char *guid_string, u8 instance,
435 const struct acpi_buffer *in)
436 {
437 	struct guid_block *block = NULL;
438 	struct wmi_block *wblock = NULL;
439 	acpi_handle handle;
440 	struct acpi_object_list input;
441 	union acpi_object params[2];
442 	char method[5] = "WS";
443 
444 	if (!guid_string || !in)
445 		return AE_BAD_DATA;
446 
447 	if (!find_guid(guid_string, &wblock))
448 		return AE_ERROR;
449 
450 	block = &wblock->gblock;
451 	handle = wblock->handle;
452 
453 	if (block->instance_count < instance)
454 		return AE_BAD_PARAMETER;
455 
456 	/* Check GUID is a data block */
457 	if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
458 		return AE_ERROR;
459 
460 	input.count = 2;
461 	input.pointer = params;
462 	params[0].type = ACPI_TYPE_INTEGER;
463 	params[0].integer.value = instance;
464 
465 	if (block->flags & ACPI_WMI_STRING) {
466 		params[1].type = ACPI_TYPE_STRING;
467 	} else {
468 		params[1].type = ACPI_TYPE_BUFFER;
469 	}
470 	params[1].buffer.length = in->length;
471 	params[1].buffer.pointer = in->pointer;
472 
473 	strncat(method, block->object_id, 2);
474 
475 	return acpi_evaluate_object(handle, method, &input, NULL);
476 }
477 EXPORT_SYMBOL_GPL(wmi_set_block);
478 
wmi_dump_wdg(const struct guid_block * g)479 static void wmi_dump_wdg(const struct guid_block *g)
480 {
481 	char guid_string[37];
482 
483 	wmi_gtoa(g->guid, guid_string);
484 
485 	pr_info("%s:\n", guid_string);
486 	pr_info("\tobject_id: %c%c\n", g->object_id[0], g->object_id[1]);
487 	pr_info("\tnotify_id: %02X\n", g->notify_id);
488 	pr_info("\treserved: %02X\n", g->reserved);
489 	pr_info("\tinstance_count: %d\n", g->instance_count);
490 	pr_info("\tflags: %#x", g->flags);
491 	if (g->flags) {
492 		if (g->flags & ACPI_WMI_EXPENSIVE)
493 			pr_cont(" ACPI_WMI_EXPENSIVE");
494 		if (g->flags & ACPI_WMI_METHOD)
495 			pr_cont(" ACPI_WMI_METHOD");
496 		if (g->flags & ACPI_WMI_STRING)
497 			pr_cont(" ACPI_WMI_STRING");
498 		if (g->flags & ACPI_WMI_EVENT)
499 			pr_cont(" ACPI_WMI_EVENT");
500 	}
501 	pr_cont("\n");
502 
503 }
504 
wmi_notify_debug(u32 value,void * context)505 static void wmi_notify_debug(u32 value, void *context)
506 {
507 	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
508 	union acpi_object *obj;
509 	acpi_status status;
510 
511 	status = wmi_get_event_data(value, &response);
512 	if (status != AE_OK) {
513 		pr_info("bad event status 0x%x\n", status);
514 		return;
515 	}
516 
517 	obj = (union acpi_object *)response.pointer;
518 
519 	if (!obj)
520 		return;
521 
522 	pr_info("DEBUG Event ");
523 	switch(obj->type) {
524 	case ACPI_TYPE_BUFFER:
525 		pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
526 		break;
527 	case ACPI_TYPE_STRING:
528 		pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
529 		break;
530 	case ACPI_TYPE_INTEGER:
531 		pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
532 		break;
533 	case ACPI_TYPE_PACKAGE:
534 		pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
535 		break;
536 	default:
537 		pr_cont("object type 0x%X\n", obj->type);
538 	}
539 	kfree(obj);
540 }
541 
542 /**
543  * wmi_install_notify_handler - Register handler for WMI events
544  * @handler: Function to handle notifications
545  * @data: Data to be returned to handler when event is fired
546  *
547  * Register a handler for events sent to the ACPI-WMI mapper device.
548  */
wmi_install_notify_handler(const char * guid,wmi_notify_handler handler,void * data)549 acpi_status wmi_install_notify_handler(const char *guid,
550 wmi_notify_handler handler, void *data)
551 {
552 	struct wmi_block *block;
553 	acpi_status status = AE_NOT_EXIST;
554 	char tmp[16], guid_input[16];
555 	struct list_head *p;
556 
557 	if (!guid || !handler)
558 		return AE_BAD_PARAMETER;
559 
560 	wmi_parse_guid(guid, tmp);
561 	wmi_swap_bytes(tmp, guid_input);
562 
563 	list_for_each(p, &wmi_block_list) {
564 		acpi_status wmi_status;
565 		block = list_entry(p, struct wmi_block, list);
566 
567 		if (memcmp(block->gblock.guid, guid_input, 16) == 0) {
568 			if (block->handler &&
569 			    block->handler != wmi_notify_debug)
570 				return AE_ALREADY_ACQUIRED;
571 
572 			block->handler = handler;
573 			block->handler_data = data;
574 
575 			wmi_status = wmi_method_enable(block, 1);
576 			if ((wmi_status != AE_OK) ||
577 			    ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
578 				status = wmi_status;
579 		}
580 	}
581 
582 	return status;
583 }
584 EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
585 
586 /**
587  * wmi_uninstall_notify_handler - Unregister handler for WMI events
588  *
589  * Unregister handler for events sent to the ACPI-WMI mapper device.
590  */
wmi_remove_notify_handler(const char * guid)591 acpi_status wmi_remove_notify_handler(const char *guid)
592 {
593 	struct wmi_block *block;
594 	acpi_status status = AE_NOT_EXIST;
595 	char tmp[16], guid_input[16];
596 	struct list_head *p;
597 
598 	if (!guid)
599 		return AE_BAD_PARAMETER;
600 
601 	wmi_parse_guid(guid, tmp);
602 	wmi_swap_bytes(tmp, guid_input);
603 
604 	list_for_each(p, &wmi_block_list) {
605 		acpi_status wmi_status;
606 		block = list_entry(p, struct wmi_block, list);
607 
608 		if (memcmp(block->gblock.guid, guid_input, 16) == 0) {
609 			if (!block->handler ||
610 			    block->handler == wmi_notify_debug)
611 				return AE_NULL_ENTRY;
612 
613 			if (debug_event) {
614 				block->handler = wmi_notify_debug;
615 				status = AE_OK;
616 			} else {
617 				wmi_status = wmi_method_enable(block, 0);
618 				block->handler = NULL;
619 				block->handler_data = NULL;
620 				if ((wmi_status != AE_OK) ||
621 				    ((wmi_status == AE_OK) &&
622 				     (status == AE_NOT_EXIST)))
623 					status = wmi_status;
624 			}
625 		}
626 	}
627 
628 	return status;
629 }
630 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
631 
632 /**
633  * wmi_get_event_data - Get WMI data associated with an event
634  *
635  * @event: Event to find
636  * @out: Buffer to hold event data. out->pointer should be freed with kfree()
637  *
638  * Returns extra data associated with an event in WMI.
639  */
wmi_get_event_data(u32 event,struct acpi_buffer * out)640 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
641 {
642 	struct acpi_object_list input;
643 	union acpi_object params[1];
644 	struct guid_block *gblock;
645 	struct wmi_block *wblock;
646 	struct list_head *p;
647 
648 	input.count = 1;
649 	input.pointer = params;
650 	params[0].type = ACPI_TYPE_INTEGER;
651 	params[0].integer.value = event;
652 
653 	list_for_each(p, &wmi_block_list) {
654 		wblock = list_entry(p, struct wmi_block, list);
655 		gblock = &wblock->gblock;
656 
657 		if ((gblock->flags & ACPI_WMI_EVENT) &&
658 			(gblock->notify_id == event))
659 			return acpi_evaluate_object(wblock->handle, "_WED",
660 				&input, out);
661 	}
662 
663 	return AE_NOT_FOUND;
664 }
665 EXPORT_SYMBOL_GPL(wmi_get_event_data);
666 
667 /**
668  * wmi_has_guid - Check if a GUID is available
669  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
670  *
671  * Check if a given GUID is defined by _WDG
672  */
wmi_has_guid(const char * guid_string)673 bool wmi_has_guid(const char *guid_string)
674 {
675 	return find_guid(guid_string, NULL);
676 }
677 EXPORT_SYMBOL_GPL(wmi_has_guid);
678 
679 /*
680  * sysfs interface
681  */
modalias_show(struct device * dev,struct device_attribute * attr,char * buf)682 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
683 			     char *buf)
684 {
685 	char guid_string[37];
686 	struct wmi_block *wblock;
687 
688 	wblock = dev_get_drvdata(dev);
689 	if (!wblock)
690 		return -ENOMEM;
691 
692 	wmi_gtoa(wblock->gblock.guid, guid_string);
693 
694 	return sprintf(buf, "wmi:%s\n", guid_string);
695 }
696 
697 static struct device_attribute wmi_dev_attrs[] = {
698 	__ATTR_RO(modalias),
699 	__ATTR_NULL
700 };
701 
wmi_dev_uevent(struct device * dev,struct kobj_uevent_env * env)702 static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
703 {
704 	char guid_string[37];
705 
706 	struct wmi_block *wblock;
707 
708 	if (add_uevent_var(env, "MODALIAS="))
709 		return -ENOMEM;
710 
711 	wblock = dev_get_drvdata(dev);
712 	if (!wblock)
713 		return -ENOMEM;
714 
715 	wmi_gtoa(wblock->gblock.guid, guid_string);
716 
717 	strcpy(&env->buf[env->buflen - 1], "wmi:");
718 	memcpy(&env->buf[env->buflen - 1 + 4], guid_string, 36);
719 	env->buflen += 40;
720 
721 	return 0;
722 }
723 
wmi_dev_free(struct device * dev)724 static void wmi_dev_free(struct device *dev)
725 {
726 	struct wmi_block *wmi_block = container_of(dev, struct wmi_block, dev);
727 
728 	kfree(wmi_block);
729 }
730 
731 static struct class wmi_class = {
732 	.name = "wmi",
733 	.dev_release = wmi_dev_free,
734 	.dev_uevent = wmi_dev_uevent,
735 	.dev_attrs = wmi_dev_attrs,
736 };
737 
wmi_create_device(const struct guid_block * gblock,struct wmi_block * wblock,acpi_handle handle)738 static int wmi_create_device(const struct guid_block *gblock,
739 			     struct wmi_block *wblock, acpi_handle handle)
740 {
741 	char guid_string[37];
742 
743 	wblock->dev.class = &wmi_class;
744 
745 	wmi_gtoa(gblock->guid, guid_string);
746 	dev_set_name(&wblock->dev, guid_string);
747 
748 	dev_set_drvdata(&wblock->dev, wblock);
749 
750 	return device_register(&wblock->dev);
751 }
752 
wmi_free_devices(void)753 static void wmi_free_devices(void)
754 {
755 	struct wmi_block *wblock, *next;
756 
757 	/* Delete devices for all the GUIDs */
758 	list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
759 		list_del(&wblock->list);
760 		if (wblock->dev.class)
761 			device_unregister(&wblock->dev);
762 		else
763 			kfree(wblock);
764 	}
765 }
766 
guid_already_parsed(const char * guid_string)767 static bool guid_already_parsed(const char *guid_string)
768 {
769 	struct wmi_block *wblock;
770 
771 	list_for_each_entry(wblock, &wmi_block_list, list)
772 		if (memcmp(wblock->gblock.guid, guid_string, 16) == 0)
773 			return true;
774 
775 	return false;
776 }
777 
778 /*
779  * Parse the _WDG method for the GUID data blocks
780  */
parse_wdg(acpi_handle handle)781 static acpi_status parse_wdg(acpi_handle handle)
782 {
783 	struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
784 	union acpi_object *obj;
785 	const struct guid_block *gblock;
786 	struct wmi_block *wblock;
787 	acpi_status status;
788 	int retval;
789 	u32 i, total;
790 
791 	status = acpi_evaluate_object(handle, "_WDG", NULL, &out);
792 	if (ACPI_FAILURE(status))
793 		return -ENXIO;
794 
795 	obj = (union acpi_object *) out.pointer;
796 	if (!obj)
797 		return -ENXIO;
798 
799 	if (obj->type != ACPI_TYPE_BUFFER) {
800 		retval = -ENXIO;
801 		goto out_free_pointer;
802 	}
803 
804 	gblock = (const struct guid_block *)obj->buffer.pointer;
805 	total = obj->buffer.length / sizeof(struct guid_block);
806 
807 	for (i = 0; i < total; i++) {
808 		if (debug_dump_wdg)
809 			wmi_dump_wdg(&gblock[i]);
810 
811 		wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
812 		if (!wblock)
813 			return AE_NO_MEMORY;
814 
815 		wblock->handle = handle;
816 		wblock->gblock = gblock[i];
817 
818 		/*
819 		  Some WMI devices, like those for nVidia hooks, have a
820 		  duplicate GUID. It's not clear what we should do in this
821 		  case yet, so for now, we'll just ignore the duplicate
822 		  for device creation.
823 		*/
824 		if (!guid_already_parsed(gblock[i].guid)) {
825 			retval = wmi_create_device(&gblock[i], wblock, handle);
826 			if (retval) {
827 				wmi_free_devices();
828 				goto out_free_pointer;
829 			}
830 		}
831 
832 		list_add_tail(&wblock->list, &wmi_block_list);
833 
834 		if (debug_event) {
835 			wblock->handler = wmi_notify_debug;
836 			wmi_method_enable(wblock, 1);
837 		}
838 	}
839 
840 	retval = 0;
841 
842 out_free_pointer:
843 	kfree(out.pointer);
844 
845 	return retval;
846 }
847 
848 /*
849  * WMI can have EmbeddedControl access regions. In which case, we just want to
850  * hand these off to the EC driver.
851  */
852 static acpi_status
acpi_wmi_ec_space_handler(u32 function,acpi_physical_address address,u32 bits,u64 * value,void * handler_context,void * region_context)853 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
854 		      u32 bits, u64 *value,
855 		      void *handler_context, void *region_context)
856 {
857 	int result = 0, i = 0;
858 	u8 temp = 0;
859 
860 	if ((address > 0xFF) || !value)
861 		return AE_BAD_PARAMETER;
862 
863 	if (function != ACPI_READ && function != ACPI_WRITE)
864 		return AE_BAD_PARAMETER;
865 
866 	if (bits != 8)
867 		return AE_BAD_PARAMETER;
868 
869 	if (function == ACPI_READ) {
870 		result = ec_read(address, &temp);
871 		(*value) |= ((u64)temp) << i;
872 	} else {
873 		temp = 0xff & ((*value) >> i);
874 		result = ec_write(address, temp);
875 	}
876 
877 	switch (result) {
878 	case -EINVAL:
879 		return AE_BAD_PARAMETER;
880 		break;
881 	case -ENODEV:
882 		return AE_NOT_FOUND;
883 		break;
884 	case -ETIME:
885 		return AE_TIME;
886 		break;
887 	default:
888 		return AE_OK;
889 	}
890 }
891 
acpi_wmi_notify(struct acpi_device * device,u32 event)892 static void acpi_wmi_notify(struct acpi_device *device, u32 event)
893 {
894 	struct guid_block *block;
895 	struct wmi_block *wblock;
896 	struct list_head *p;
897 	char guid_string[37];
898 
899 	list_for_each(p, &wmi_block_list) {
900 		wblock = list_entry(p, struct wmi_block, list);
901 		block = &wblock->gblock;
902 
903 		if ((block->flags & ACPI_WMI_EVENT) &&
904 			(block->notify_id == event)) {
905 			if (wblock->handler)
906 				wblock->handler(event, wblock->handler_data);
907 			if (debug_event) {
908 				wmi_gtoa(wblock->gblock.guid, guid_string);
909 				pr_info("DEBUG Event GUID: %s\n", guid_string);
910 			}
911 
912 			acpi_bus_generate_netlink_event(
913 				device->pnp.device_class, dev_name(&device->dev),
914 				event, 0);
915 			break;
916 		}
917 	}
918 }
919 
acpi_wmi_remove(struct acpi_device * device)920 static int acpi_wmi_remove(struct acpi_device *device)
921 {
922 	acpi_remove_address_space_handler(device->handle,
923 				ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
924 	wmi_free_devices();
925 
926 	return 0;
927 }
928 
acpi_wmi_add(struct acpi_device * device)929 static int acpi_wmi_add(struct acpi_device *device)
930 {
931 	acpi_status status;
932 	int error;
933 
934 	status = acpi_install_address_space_handler(device->handle,
935 						    ACPI_ADR_SPACE_EC,
936 						    &acpi_wmi_ec_space_handler,
937 						    NULL, NULL);
938 	if (ACPI_FAILURE(status)) {
939 		pr_err("Error installing EC region handler\n");
940 		return -ENODEV;
941 	}
942 
943 	error = parse_wdg(device->handle);
944 	if (error) {
945 		acpi_remove_address_space_handler(device->handle,
946 						  ACPI_ADR_SPACE_EC,
947 						  &acpi_wmi_ec_space_handler);
948 		pr_err("Failed to parse WDG method\n");
949 		return error;
950 	}
951 
952 	return 0;
953 }
954 
acpi_wmi_init(void)955 static int __init acpi_wmi_init(void)
956 {
957 	int error;
958 
959 	if (acpi_disabled)
960 		return -ENODEV;
961 
962 	error = class_register(&wmi_class);
963 	if (error)
964 		return error;
965 
966 	error = acpi_bus_register_driver(&acpi_wmi_driver);
967 	if (error) {
968 		pr_err("Error loading mapper\n");
969 		class_unregister(&wmi_class);
970 		return error;
971 	}
972 
973 	pr_info("Mapper loaded\n");
974 	return 0;
975 }
976 
acpi_wmi_exit(void)977 static void __exit acpi_wmi_exit(void)
978 {
979 	acpi_bus_unregister_driver(&acpi_wmi_driver);
980 	class_unregister(&wmi_class);
981 
982 	pr_info("Mapper unloaded\n");
983 }
984 
985 subsys_initcall(acpi_wmi_init);
986 module_exit(acpi_wmi_exit);
987