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