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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * ACPI-WMI mapping driver
4 *
5 * Copyright (C) 2007-2008 Carlos Corbacho <carlos@strangeworlds.co.uk>
6 *
7 * GUID parsing code from ldm.c is:
8 * Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
9 * Copyright (c) 2001-2007 Anton Altaparmakov
10 * Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
11 *
12 * WMI bus infrastructure by Andrew Lutomirski and Darren Hart:
13 * Copyright (C) 2015 Andrew Lutomirski
14 * Copyright (C) 2017 VMware, Inc. All Rights Reserved.
15 */
16
17#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18
19#include <linux/acpi.h>
20#include <linux/device.h>
21#include <linux/init.h>
22#include <linux/kernel.h>
23#include <linux/list.h>
24#include <linux/miscdevice.h>
25#include <linux/module.h>
26#include <linux/platform_device.h>
27#include <linux/slab.h>
28#include <linux/types.h>
29#include <linux/uaccess.h>
30#include <linux/uuid.h>
31#include <linux/wmi.h>
32#include <linux/fs.h>
33#include <uapi/linux/wmi.h>
34
35MODULE_AUTHOR("Carlos Corbacho");
36MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
37MODULE_LICENSE("GPL");
38
39static LIST_HEAD(wmi_block_list);
40
41struct guid_block {
42 char guid[16];
43 union {
44 char object_id[2];
45 struct {
46 unsigned char notify_id;
47 unsigned char reserved;
48 };
49 };
50 u8 instance_count;
51 u8 flags;
52};
53
54struct wmi_block {
55 struct wmi_device dev;
56 struct list_head list;
57 struct guid_block gblock;
58 struct miscdevice char_dev;
59 struct mutex char_mutex;
60 struct acpi_device *acpi_device;
61 wmi_notify_handler handler;
62 void *handler_data;
63 u64 req_buf_size;
64
65 bool read_takes_no_args;
66};
67
68
69/*
70 * If the GUID data block is marked as expensive, we must enable and
71 * explicitily disable data collection.
72 */
73#define ACPI_WMI_EXPENSIVE 0x1
74#define ACPI_WMI_METHOD 0x2 /* GUID is a method */
75#define ACPI_WMI_STRING 0x4 /* GUID takes & returns a string */
76#define ACPI_WMI_EVENT 0x8 /* GUID is an event */
77
78static bool debug_event;
79module_param(debug_event, bool, 0444);
80MODULE_PARM_DESC(debug_event,
81 "Log WMI Events [0/1]");
82
83static bool debug_dump_wdg;
84module_param(debug_dump_wdg, bool, 0444);
85MODULE_PARM_DESC(debug_dump_wdg,
86 "Dump available WMI interfaces [0/1]");
87
88static int acpi_wmi_remove(struct platform_device *device);
89static int acpi_wmi_probe(struct platform_device *device);
90
91static const struct acpi_device_id wmi_device_ids[] = {
92 {"PNP0C14", 0},
93 {"pnp0c14", 0},
94 {"", 0},
95};
96MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
97
98static struct platform_driver acpi_wmi_driver = {
99 .driver = {
100 .name = "acpi-wmi",
101 .acpi_match_table = wmi_device_ids,
102 },
103 .probe = acpi_wmi_probe,
104 .remove = acpi_wmi_remove,
105};
106
107/*
108 * GUID parsing functions
109 */
110
111static bool find_guid(const char *guid_string, struct wmi_block **out)
112{
113 guid_t guid_input;
114 struct wmi_block *wblock;
115 struct guid_block *block;
116
117 if (guid_parse(guid_string, &guid_input))
118 return false;
119
120 list_for_each_entry(wblock, &wmi_block_list, list) {
121 block = &wblock->gblock;
122
123 if (memcmp(block->guid, &guid_input, 16) == 0) {
124 if (out)
125 *out = wblock;
126 return true;
127 }
128 }
129 return false;
130}
131
132static const void *find_guid_context(struct wmi_block *wblock,
133 struct wmi_driver *wdriver)
134{
135 const struct wmi_device_id *id;
136 guid_t guid_input;
137
138 if (wblock == NULL || wdriver == NULL)
139 return NULL;
140 if (wdriver->id_table == NULL)
141 return NULL;
142
143 id = wdriver->id_table;
144 while (*id->guid_string) {
145 if (guid_parse(id->guid_string, &guid_input))
146 continue;
147 if (!memcmp(wblock->gblock.guid, &guid_input, 16))
148 return id->context;
149 id++;
150 }
151 return NULL;
152}
153
154static int get_subobj_info(acpi_handle handle, const char *pathname,
155 struct acpi_device_info **info)
156{
157 struct acpi_device_info *dummy_info, **info_ptr;
158 acpi_handle subobj_handle;
159 acpi_status status;
160
161 status = acpi_get_handle(handle, (char *)pathname, &subobj_handle);
162 if (status == AE_NOT_FOUND)
163 return -ENOENT;
164 else if (ACPI_FAILURE(status))
165 return -EIO;
166
167 info_ptr = info ? info : &dummy_info;
168 status = acpi_get_object_info(subobj_handle, info_ptr);
169 if (ACPI_FAILURE(status))
170 return -EIO;
171
172 if (!info)
173 kfree(dummy_info);
174
175 return 0;
176}
177
178static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable)
179{
180 struct guid_block *block = NULL;
181 char method[5];
182 acpi_status status;
183 acpi_handle handle;
184
185 block = &wblock->gblock;
186 handle = wblock->acpi_device->handle;
187
188 snprintf(method, 5, "WE%02X", block->notify_id);
189 status = acpi_execute_simple_method(handle, method, enable);
190
191 if (status != AE_OK && status != AE_NOT_FOUND)
192 return status;
193 else
194 return AE_OK;
195}
196
197/*
198 * Exported WMI functions
199 */
200
201/**
202 * set_required_buffer_size - Sets the buffer size needed for performing IOCTL
203 * @wdev: A wmi bus device from a driver
204 * @length: Required buffer size
205 *
206 * Allocates memory needed for buffer, stores the buffer size in that memory
207 */
208int set_required_buffer_size(struct wmi_device *wdev, u64 length)
209{
210 struct wmi_block *wblock;
211
212 wblock = container_of(wdev, struct wmi_block, dev);
213 wblock->req_buf_size = length;
214
215 return 0;
216}
217EXPORT_SYMBOL_GPL(set_required_buffer_size);
218
219/**
220 * wmi_evaluate_method - Evaluate a WMI method
221 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
222 * @instance: Instance index
223 * @method_id: Method ID to call
224 * @in: Buffer containing input for the method call
225 * @out: Empty buffer to return the method results
226 *
227 * Call an ACPI-WMI method
228 */
229acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
230u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
231{
232 struct wmi_block *wblock = NULL;
233
234 if (!find_guid(guid_string, &wblock))
235 return AE_ERROR;
236 return wmidev_evaluate_method(&wblock->dev, instance, method_id,
237 in, out);
238}
239EXPORT_SYMBOL_GPL(wmi_evaluate_method);
240
241/**
242 * wmidev_evaluate_method - Evaluate a WMI method
243 * @wdev: A wmi bus device from a driver
244 * @instance: Instance index
245 * @method_id: Method ID to call
246 * @in: Buffer containing input for the method call
247 * @out: Empty buffer to return the method results
248 *
249 * Call an ACPI-WMI method
250 */
251acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance,
252 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
253{
254 struct guid_block *block = NULL;
255 struct wmi_block *wblock = NULL;
256 acpi_handle handle;
257 acpi_status status;
258 struct acpi_object_list input;
259 union acpi_object params[3];
260 char method[5] = "WM";
261
262 wblock = container_of(wdev, struct wmi_block, dev);
263 block = &wblock->gblock;
264 handle = wblock->acpi_device->handle;
265
266 if (!(block->flags & ACPI_WMI_METHOD))
267 return AE_BAD_DATA;
268
269 if (block->instance_count <= instance)
270 return AE_BAD_PARAMETER;
271
272 input.count = 2;
273 input.pointer = params;
274 params[0].type = ACPI_TYPE_INTEGER;
275 params[0].integer.value = instance;
276 params[1].type = ACPI_TYPE_INTEGER;
277 params[1].integer.value = method_id;
278
279 if (in) {
280 input.count = 3;
281
282 if (block->flags & ACPI_WMI_STRING) {
283 params[2].type = ACPI_TYPE_STRING;
284 } else {
285 params[2].type = ACPI_TYPE_BUFFER;
286 }
287 params[2].buffer.length = in->length;
288 params[2].buffer.pointer = in->pointer;
289 }
290
291 strncat(method, block->object_id, 2);
292
293 status = acpi_evaluate_object(handle, method, &input, out);
294
295 return status;
296}
297EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
298
299static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
300 struct acpi_buffer *out)
301{
302 struct guid_block *block = NULL;
303 acpi_handle handle;
304 acpi_status status, wc_status = AE_ERROR;
305 struct acpi_object_list input;
306 union acpi_object wq_params[1];
307 char method[5];
308 char wc_method[5] = "WC";
309
310 if (!out)
311 return AE_BAD_PARAMETER;
312
313 block = &wblock->gblock;
314 handle = wblock->acpi_device->handle;
315
316 if (block->instance_count <= instance)
317 return AE_BAD_PARAMETER;
318
319 /* Check GUID is a data block */
320 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
321 return AE_ERROR;
322
323 input.count = 1;
324 input.pointer = wq_params;
325 wq_params[0].type = ACPI_TYPE_INTEGER;
326 wq_params[0].integer.value = instance;
327
328 if (instance == 0 && wblock->read_takes_no_args)
329 input.count = 0;
330
331 /*
332 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
333 * enable collection.
334 */
335 if (block->flags & ACPI_WMI_EXPENSIVE) {
336 strncat(wc_method, block->object_id, 2);
337
338 /*
339 * Some GUIDs break the specification by declaring themselves
340 * expensive, but have no corresponding WCxx method. So we
341 * should not fail if this happens.
342 */
343 wc_status = acpi_execute_simple_method(handle, wc_method, 1);
344 }
345
346 strcpy(method, "WQ");
347 strncat(method, block->object_id, 2);
348
349 status = acpi_evaluate_object(handle, method, &input, out);
350
351 /*
352 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
353 * the WQxx method failed - we should disable collection anyway.
354 */
355 if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
356 status = acpi_execute_simple_method(handle, wc_method, 0);
357 }
358
359 return status;
360}
361
362/**
363 * wmi_query_block - Return contents of a WMI block (deprecated)
364 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
365 * @instance: Instance index
366 * @out: Empty buffer to return the contents of the data block to
367 *
368 * Return the contents of an ACPI-WMI data block to a buffer
369 */
370acpi_status wmi_query_block(const char *guid_string, u8 instance,
371 struct acpi_buffer *out)
372{
373 struct wmi_block *wblock;
374
375 if (!guid_string)
376 return AE_BAD_PARAMETER;
377
378 if (!find_guid(guid_string, &wblock))
379 return AE_ERROR;
380
381 return __query_block(wblock, instance, out);
382}
383EXPORT_SYMBOL_GPL(wmi_query_block);
384
385union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
386{
387 struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
388 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
389
390 if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
391 return NULL;
392
393 return (union acpi_object *)out.pointer;
394}
395EXPORT_SYMBOL_GPL(wmidev_block_query);
396
397/**
398 * wmi_set_block - Write to a WMI block
399 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
400 * @instance: Instance index
401 * @in: Buffer containing new values for the data block
402 *
403 * Write the contents of the input buffer to an ACPI-WMI data block
404 */
405acpi_status wmi_set_block(const char *guid_string, u8 instance,
406 const struct acpi_buffer *in)
407{
408 struct guid_block *block = NULL;
409 struct wmi_block *wblock = NULL;
410 acpi_handle handle;
411 struct acpi_object_list input;
412 union acpi_object params[2];
413 char method[5] = "WS";
414
415 if (!guid_string || !in)
416 return AE_BAD_DATA;
417
418 if (!find_guid(guid_string, &wblock))
419 return AE_ERROR;
420
421 block = &wblock->gblock;
422 handle = wblock->acpi_device->handle;
423
424 if (block->instance_count <= instance)
425 return AE_BAD_PARAMETER;
426
427 /* Check GUID is a data block */
428 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
429 return AE_ERROR;
430
431 input.count = 2;
432 input.pointer = params;
433 params[0].type = ACPI_TYPE_INTEGER;
434 params[0].integer.value = instance;
435
436 if (block->flags & ACPI_WMI_STRING) {
437 params[1].type = ACPI_TYPE_STRING;
438 } else {
439 params[1].type = ACPI_TYPE_BUFFER;
440 }
441 params[1].buffer.length = in->length;
442 params[1].buffer.pointer = in->pointer;
443
444 strncat(method, block->object_id, 2);
445
446 return acpi_evaluate_object(handle, method, &input, NULL);
447}
448EXPORT_SYMBOL_GPL(wmi_set_block);
449
450static void wmi_dump_wdg(const struct guid_block *g)
451{
452 pr_info("%pUL:\n", g->guid);
453 if (g->flags & ACPI_WMI_EVENT)
454 pr_info("\tnotify_id: 0x%02X\n", g->notify_id);
455 else
456 pr_info("\tobject_id: %2pE\n", g->object_id);
457 pr_info("\tinstance_count: %d\n", g->instance_count);
458 pr_info("\tflags: %#x", g->flags);
459 if (g->flags) {
460 if (g->flags & ACPI_WMI_EXPENSIVE)
461 pr_cont(" ACPI_WMI_EXPENSIVE");
462 if (g->flags & ACPI_WMI_METHOD)
463 pr_cont(" ACPI_WMI_METHOD");
464 if (g->flags & ACPI_WMI_STRING)
465 pr_cont(" ACPI_WMI_STRING");
466 if (g->flags & ACPI_WMI_EVENT)
467 pr_cont(" ACPI_WMI_EVENT");
468 }
469 pr_cont("\n");
470
471}
472
473static void wmi_notify_debug(u32 value, void *context)
474{
475 struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
476 union acpi_object *obj;
477 acpi_status status;
478
479 status = wmi_get_event_data(value, &response);
480 if (status != AE_OK) {
481 pr_info("bad event status 0x%x\n", status);
482 return;
483 }
484
485 obj = (union acpi_object *)response.pointer;
486
487 if (!obj)
488 return;
489
490 pr_info("DEBUG Event ");
491 switch(obj->type) {
492 case ACPI_TYPE_BUFFER:
493 pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
494 break;
495 case ACPI_TYPE_STRING:
496 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
497 break;
498 case ACPI_TYPE_INTEGER:
499 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
500 break;
501 case ACPI_TYPE_PACKAGE:
502 pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
503 break;
504 default:
505 pr_cont("object type 0x%X\n", obj->type);
506 }
507 kfree(obj);
508}
509
510/**
511 * wmi_install_notify_handler - Register handler for WMI events
512 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
513 * @handler: Function to handle notifications
514 * @data: Data to be returned to handler when event is fired
515 *
516 * Register a handler for events sent to the ACPI-WMI mapper device.
517 */
518acpi_status wmi_install_notify_handler(const char *guid,
519wmi_notify_handler handler, void *data)
520{
521 struct wmi_block *block;
522 acpi_status status = AE_NOT_EXIST;
523 guid_t guid_input;
524
525 if (!guid || !handler)
526 return AE_BAD_PARAMETER;
527
528 if (guid_parse(guid, &guid_input))
529 return AE_BAD_PARAMETER;
530
531 list_for_each_entry(block, &wmi_block_list, list) {
532 acpi_status wmi_status;
533
534 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
535 if (block->handler &&
536 block->handler != wmi_notify_debug)
537 return AE_ALREADY_ACQUIRED;
538
539 block->handler = handler;
540 block->handler_data = data;
541
542 wmi_status = wmi_method_enable(block, 1);
543 if ((wmi_status != AE_OK) ||
544 ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
545 status = wmi_status;
546 }
547 }
548
549 return status;
550}
551EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
552
553/**
554 * wmi_uninstall_notify_handler - Unregister handler for WMI events
555 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
556 *
557 * Unregister handler for events sent to the ACPI-WMI mapper device.
558 */
559acpi_status wmi_remove_notify_handler(const char *guid)
560{
561 struct wmi_block *block;
562 acpi_status status = AE_NOT_EXIST;
563 guid_t guid_input;
564
565 if (!guid)
566 return AE_BAD_PARAMETER;
567
568 if (guid_parse(guid, &guid_input))
569 return AE_BAD_PARAMETER;
570
571 list_for_each_entry(block, &wmi_block_list, list) {
572 acpi_status wmi_status;
573
574 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
575 if (!block->handler ||
576 block->handler == wmi_notify_debug)
577 return AE_NULL_ENTRY;
578
579 if (debug_event) {
580 block->handler = wmi_notify_debug;
581 status = AE_OK;
582 } else {
583 wmi_status = wmi_method_enable(block, 0);
584 block->handler = NULL;
585 block->handler_data = NULL;
586 if ((wmi_status != AE_OK) ||
587 ((wmi_status == AE_OK) &&
588 (status == AE_NOT_EXIST)))
589 status = wmi_status;
590 }
591 }
592 }
593
594 return status;
595}
596EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
597
598/**
599 * wmi_get_event_data - Get WMI data associated with an event
600 *
601 * @event: Event to find
602 * @out: Buffer to hold event data. out->pointer should be freed with kfree()
603 *
604 * Returns extra data associated with an event in WMI.
605 */
606acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
607{
608 struct acpi_object_list input;
609 union acpi_object params[1];
610 struct guid_block *gblock;
611 struct wmi_block *wblock;
612
613 input.count = 1;
614 input.pointer = params;
615 params[0].type = ACPI_TYPE_INTEGER;
616 params[0].integer.value = event;
617
618 list_for_each_entry(wblock, &wmi_block_list, list) {
619 gblock = &wblock->gblock;
620
621 if ((gblock->flags & ACPI_WMI_EVENT) &&
622 (gblock->notify_id == event))
623 return acpi_evaluate_object(wblock->acpi_device->handle,
624 "_WED", &input, out);
625 }
626
627 return AE_NOT_FOUND;
628}
629EXPORT_SYMBOL_GPL(wmi_get_event_data);
630
631/**
632 * wmi_has_guid - Check if a GUID is available
633 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
634 *
635 * Check if a given GUID is defined by _WDG
636 */
637bool wmi_has_guid(const char *guid_string)
638{
639 return find_guid(guid_string, NULL);
640}
641EXPORT_SYMBOL_GPL(wmi_has_guid);
642
643/**
644 * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID
645 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
646 *
647 * Find the _UID of ACPI device associated with this WMI GUID.
648 *
649 * Return: The ACPI _UID field value or NULL if the WMI GUID was not found
650 */
651char *wmi_get_acpi_device_uid(const char *guid_string)
652{
653 struct wmi_block *wblock = NULL;
654
655 if (!find_guid(guid_string, &wblock))
656 return NULL;
657
658 return acpi_device_uid(wblock->acpi_device);
659}
660EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
661
662static struct wmi_block *dev_to_wblock(struct device *dev)
663{
664 return container_of(dev, struct wmi_block, dev.dev);
665}
666
667static struct wmi_device *dev_to_wdev(struct device *dev)
668{
669 return container_of(dev, struct wmi_device, dev);
670}
671
672/*
673 * sysfs interface
674 */
675static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
676 char *buf)
677{
678 struct wmi_block *wblock = dev_to_wblock(dev);
679
680 return sprintf(buf, "wmi:%pUL\n", wblock->gblock.guid);
681}
682static DEVICE_ATTR_RO(modalias);
683
684static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
685 char *buf)
686{
687 struct wmi_block *wblock = dev_to_wblock(dev);
688
689 return sprintf(buf, "%pUL\n", wblock->gblock.guid);
690}
691static DEVICE_ATTR_RO(guid);
692
693static ssize_t instance_count_show(struct device *dev,
694 struct device_attribute *attr, char *buf)
695{
696 struct wmi_block *wblock = dev_to_wblock(dev);
697
698 return sprintf(buf, "%d\n", (int)wblock->gblock.instance_count);
699}
700static DEVICE_ATTR_RO(instance_count);
701
702static ssize_t expensive_show(struct device *dev,
703 struct device_attribute *attr, char *buf)
704{
705 struct wmi_block *wblock = dev_to_wblock(dev);
706
707 return sprintf(buf, "%d\n",
708 (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
709}
710static DEVICE_ATTR_RO(expensive);
711
712static struct attribute *wmi_attrs[] = {
713 &dev_attr_modalias.attr,
714 &dev_attr_guid.attr,
715 &dev_attr_instance_count.attr,
716 &dev_attr_expensive.attr,
717 NULL,
718};
719ATTRIBUTE_GROUPS(wmi);
720
721static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
722 char *buf)
723{
724 struct wmi_block *wblock = dev_to_wblock(dev);
725
726 return sprintf(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
727}
728static DEVICE_ATTR_RO(notify_id);
729
730static struct attribute *wmi_event_attrs[] = {
731 &dev_attr_notify_id.attr,
732 NULL,
733};
734ATTRIBUTE_GROUPS(wmi_event);
735
736static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
737 char *buf)
738{
739 struct wmi_block *wblock = dev_to_wblock(dev);
740
741 return sprintf(buf, "%c%c\n", wblock->gblock.object_id[0],
742 wblock->gblock.object_id[1]);
743}
744static DEVICE_ATTR_RO(object_id);
745
746static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
747 char *buf)
748{
749 struct wmi_device *wdev = dev_to_wdev(dev);
750
751 return sprintf(buf, "%d\n", (int)wdev->setable);
752}
753static DEVICE_ATTR_RO(setable);
754
755static struct attribute *wmi_data_attrs[] = {
756 &dev_attr_object_id.attr,
757 &dev_attr_setable.attr,
758 NULL,
759};
760ATTRIBUTE_GROUPS(wmi_data);
761
762static struct attribute *wmi_method_attrs[] = {
763 &dev_attr_object_id.attr,
764 NULL,
765};
766ATTRIBUTE_GROUPS(wmi_method);
767
768static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
769{
770 struct wmi_block *wblock = dev_to_wblock(dev);
771
772 if (add_uevent_var(env, "MODALIAS=wmi:%pUL", wblock->gblock.guid))
773 return -ENOMEM;
774
775 if (add_uevent_var(env, "WMI_GUID=%pUL", wblock->gblock.guid))
776 return -ENOMEM;
777
778 return 0;
779}
780
781static void wmi_dev_release(struct device *dev)
782{
783 struct wmi_block *wblock = dev_to_wblock(dev);
784
785 kfree(wblock);
786}
787
788static int wmi_dev_match(struct device *dev, struct device_driver *driver)
789{
790 struct wmi_driver *wmi_driver =
791 container_of(driver, struct wmi_driver, driver);
792 struct wmi_block *wblock = dev_to_wblock(dev);
793 const struct wmi_device_id *id = wmi_driver->id_table;
794
795 if (id == NULL)
796 return 0;
797
798 while (*id->guid_string) {
799 guid_t driver_guid;
800
801 if (WARN_ON(guid_parse(id->guid_string, &driver_guid)))
802 continue;
803 if (!memcmp(&driver_guid, wblock->gblock.guid, 16))
804 return 1;
805
806 id++;
807 }
808
809 return 0;
810}
811static int wmi_char_open(struct inode *inode, struct file *filp)
812{
813 const char *driver_name = filp->f_path.dentry->d_iname;
814 struct wmi_block *wblock = NULL;
815 struct wmi_block *next = NULL;
816
817 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
818 if (!wblock->dev.dev.driver)
819 continue;
820 if (strcmp(driver_name, wblock->dev.dev.driver->name) == 0) {
821 filp->private_data = wblock;
822 break;
823 }
824 }
825
826 if (!filp->private_data)
827 return -ENODEV;
828
829 return nonseekable_open(inode, filp);
830}
831
832static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
833 size_t length, loff_t *offset)
834{
835 struct wmi_block *wblock = filp->private_data;
836
837 return simple_read_from_buffer(buffer, length, offset,
838 &wblock->req_buf_size,
839 sizeof(wblock->req_buf_size));
840}
841
842static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
843{
844 struct wmi_ioctl_buffer __user *input =
845 (struct wmi_ioctl_buffer __user *) arg;
846 struct wmi_block *wblock = filp->private_data;
847 struct wmi_ioctl_buffer *buf = NULL;
848 struct wmi_driver *wdriver = NULL;
849 int ret;
850
851 if (_IOC_TYPE(cmd) != WMI_IOC)
852 return -ENOTTY;
853
854 /* make sure we're not calling a higher instance than exists*/
855 if (_IOC_NR(cmd) >= wblock->gblock.instance_count)
856 return -EINVAL;
857
858 mutex_lock(&wblock->char_mutex);
859 buf = wblock->handler_data;
860 if (get_user(buf->length, &input->length)) {
861 dev_dbg(&wblock->dev.dev, "Read length from user failed\n");
862 ret = -EFAULT;
863 goto out_ioctl;
864 }
865 /* if it's too small, abort */
866 if (buf->length < wblock->req_buf_size) {
867 dev_err(&wblock->dev.dev,
868 "Buffer %lld too small, need at least %lld\n",
869 buf->length, wblock->req_buf_size);
870 ret = -EINVAL;
871 goto out_ioctl;
872 }
873 /* if it's too big, warn, driver will only use what is needed */
874 if (buf->length > wblock->req_buf_size)
875 dev_warn(&wblock->dev.dev,
876 "Buffer %lld is bigger than required %lld\n",
877 buf->length, wblock->req_buf_size);
878
879 /* copy the structure from userspace */
880 if (copy_from_user(buf, input, wblock->req_buf_size)) {
881 dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n",
882 wblock->req_buf_size);
883 ret = -EFAULT;
884 goto out_ioctl;
885 }
886
887 /* let the driver do any filtering and do the call */
888 wdriver = container_of(wblock->dev.dev.driver,
889 struct wmi_driver, driver);
890 if (!try_module_get(wdriver->driver.owner)) {
891 ret = -EBUSY;
892 goto out_ioctl;
893 }
894 ret = wdriver->filter_callback(&wblock->dev, cmd, buf);
895 module_put(wdriver->driver.owner);
896 if (ret)
897 goto out_ioctl;
898
899 /* return the result (only up to our internal buffer size) */
900 if (copy_to_user(input, buf, wblock->req_buf_size)) {
901 dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n",
902 wblock->req_buf_size);
903 ret = -EFAULT;
904 }
905
906out_ioctl:
907 mutex_unlock(&wblock->char_mutex);
908 return ret;
909}
910
911static const struct file_operations wmi_fops = {
912 .owner = THIS_MODULE,
913 .read = wmi_char_read,
914 .open = wmi_char_open,
915 .unlocked_ioctl = wmi_ioctl,
916 .compat_ioctl = compat_ptr_ioctl,
917};
918
919static int wmi_dev_probe(struct device *dev)
920{
921 struct wmi_block *wblock = dev_to_wblock(dev);
922 struct wmi_driver *wdriver =
923 container_of(dev->driver, struct wmi_driver, driver);
924 int ret = 0;
925 char *buf;
926
927 if (ACPI_FAILURE(wmi_method_enable(wblock, 1)))
928 dev_warn(dev, "failed to enable device -- probing anyway\n");
929
930 if (wdriver->probe) {
931 ret = wdriver->probe(dev_to_wdev(dev),
932 find_guid_context(wblock, wdriver));
933 if (ret != 0)
934 goto probe_failure;
935 }
936
937 /* driver wants a character device made */
938 if (wdriver->filter_callback) {
939 /* check that required buffer size declared by driver or MOF */
940 if (!wblock->req_buf_size) {
941 dev_err(&wblock->dev.dev,
942 "Required buffer size not set\n");
943 ret = -EINVAL;
944 goto probe_failure;
945 }
946
947 wblock->handler_data = kmalloc(wblock->req_buf_size,
948 GFP_KERNEL);
949 if (!wblock->handler_data) {
950 ret = -ENOMEM;
951 goto probe_failure;
952 }
953
954 buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name);
955 if (!buf) {
956 ret = -ENOMEM;
957 goto probe_string_failure;
958 }
959 wblock->char_dev.minor = MISC_DYNAMIC_MINOR;
960 wblock->char_dev.name = buf;
961 wblock->char_dev.fops = &wmi_fops;
962 wblock->char_dev.mode = 0444;
963 ret = misc_register(&wblock->char_dev);
964 if (ret) {
965 dev_warn(dev, "failed to register char dev: %d\n", ret);
966 ret = -ENOMEM;
967 goto probe_misc_failure;
968 }
969 }
970
971 return 0;
972
973probe_misc_failure:
974 kfree(buf);
975probe_string_failure:
976 kfree(wblock->handler_data);
977probe_failure:
978 if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
979 dev_warn(dev, "failed to disable device\n");
980 return ret;
981}
982
983static int wmi_dev_remove(struct device *dev)
984{
985 struct wmi_block *wblock = dev_to_wblock(dev);
986 struct wmi_driver *wdriver =
987 container_of(dev->driver, struct wmi_driver, driver);
988
989 if (wdriver->filter_callback) {
990 misc_deregister(&wblock->char_dev);
991 kfree(wblock->char_dev.name);
992 kfree(wblock->handler_data);
993 }
994
995 if (wdriver->remove)
996 wdriver->remove(dev_to_wdev(dev));
997
998 if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
999 dev_warn(dev, "failed to disable device\n");
1000
1001 return 0;
1002}
1003
1004static struct class wmi_bus_class = {
1005 .name = "wmi_bus",
1006};
1007
1008static struct bus_type wmi_bus_type = {
1009 .name = "wmi",
1010 .dev_groups = wmi_groups,
1011 .match = wmi_dev_match,
1012 .uevent = wmi_dev_uevent,
1013 .probe = wmi_dev_probe,
1014 .remove = wmi_dev_remove,
1015};
1016
1017static const struct device_type wmi_type_event = {
1018 .name = "event",
1019 .groups = wmi_event_groups,
1020 .release = wmi_dev_release,
1021};
1022
1023static const struct device_type wmi_type_method = {
1024 .name = "method",
1025 .groups = wmi_method_groups,
1026 .release = wmi_dev_release,
1027};
1028
1029static const struct device_type wmi_type_data = {
1030 .name = "data",
1031 .groups = wmi_data_groups,
1032 .release = wmi_dev_release,
1033};
1034
1035static int wmi_create_device(struct device *wmi_bus_dev,
1036 const struct guid_block *gblock,
1037 struct wmi_block *wblock,
1038 struct acpi_device *device)
1039{
1040 struct acpi_device_info *info;
1041 char method[5];
1042 int result;
1043
1044 if (gblock->flags & ACPI_WMI_EVENT) {
1045 wblock->dev.dev.type = &wmi_type_event;
1046 goto out_init;
1047 }
1048
1049 if (gblock->flags & ACPI_WMI_METHOD) {
1050 wblock->dev.dev.type = &wmi_type_method;
1051 mutex_init(&wblock->char_mutex);
1052 goto out_init;
1053 }
1054
1055 /*
1056 * Data Block Query Control Method (WQxx by convention) is
1057 * required per the WMI documentation. If it is not present,
1058 * we ignore this data block.
1059 */
1060 strcpy(method, "WQ");
1061 strncat(method, wblock->gblock.object_id, 2);
1062 result = get_subobj_info(device->handle, method, &info);
1063
1064 if (result) {
1065 dev_warn(wmi_bus_dev,
1066 "%s data block query control method not found\n",
1067 method);
1068 return result;
1069 }
1070
1071 wblock->dev.dev.type = &wmi_type_data;
1072
1073 /*
1074 * The Microsoft documentation specifically states:
1075 *
1076 * Data blocks registered with only a single instance
1077 * can ignore the parameter.
1078 *
1079 * ACPICA will get mad at us if we call the method with the wrong number
1080 * of arguments, so check what our method expects. (On some Dell
1081 * laptops, WQxx may not be a method at all.)
1082 */
1083 if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1084 wblock->read_takes_no_args = true;
1085
1086 kfree(info);
1087
1088 strcpy(method, "WS");
1089 strncat(method, wblock->gblock.object_id, 2);
1090 result = get_subobj_info(device->handle, method, NULL);
1091
1092 if (result == 0)
1093 wblock->dev.setable = true;
1094
1095 out_init:
1096 wblock->dev.dev.bus = &wmi_bus_type;
1097 wblock->dev.dev.parent = wmi_bus_dev;
1098
1099 dev_set_name(&wblock->dev.dev, "%pUL", gblock->guid);
1100
1101 device_initialize(&wblock->dev.dev);
1102
1103 return 0;
1104}
1105
1106static void wmi_free_devices(struct acpi_device *device)
1107{
1108 struct wmi_block *wblock, *next;
1109
1110 /* Delete devices for all the GUIDs */
1111 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1112 if (wblock->acpi_device == device) {
1113 list_del(&wblock->list);
1114 device_unregister(&wblock->dev.dev);
1115 }
1116 }
1117}
1118
1119static bool guid_already_parsed(struct acpi_device *device, const u8 *guid)
1120{
1121 struct wmi_block *wblock;
1122
1123 list_for_each_entry(wblock, &wmi_block_list, list) {
1124 if (memcmp(wblock->gblock.guid, guid, 16) == 0) {
1125 /*
1126 * Because we historically didn't track the relationship
1127 * between GUIDs and ACPI nodes, we don't know whether
1128 * we need to suppress GUIDs that are unique on a
1129 * given node but duplicated across nodes.
1130 */
1131 dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
1132 guid, dev_name(&wblock->acpi_device->dev));
1133 return true;
1134 }
1135 }
1136
1137 return false;
1138}
1139
1140/*
1141 * Parse the _WDG method for the GUID data blocks
1142 */
1143static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
1144{
1145 struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1146 const struct guid_block *gblock;
1147 struct wmi_block *wblock, *next;
1148 union acpi_object *obj;
1149 acpi_status status;
1150 int retval = 0;
1151 u32 i, total;
1152
1153 status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1154 if (ACPI_FAILURE(status))
1155 return -ENXIO;
1156
1157 obj = (union acpi_object *) out.pointer;
1158 if (!obj)
1159 return -ENXIO;
1160
1161 if (obj->type != ACPI_TYPE_BUFFER) {
1162 retval = -ENXIO;
1163 goto out_free_pointer;
1164 }
1165
1166 gblock = (const struct guid_block *)obj->buffer.pointer;
1167 total = obj->buffer.length / sizeof(struct guid_block);
1168
1169 for (i = 0; i < total; i++) {
1170 if (debug_dump_wdg)
1171 wmi_dump_wdg(&gblock[i]);
1172
1173 /*
1174 * Some WMI devices, like those for nVidia hooks, have a
1175 * duplicate GUID. It's not clear what we should do in this
1176 * case yet, so for now, we'll just ignore the duplicate
1177 * for device creation.
1178 */
1179 if (guid_already_parsed(device, gblock[i].guid))
1180 continue;
1181
1182 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
1183 if (!wblock) {
1184 retval = -ENOMEM;
1185 break;
1186 }
1187
1188 wblock->acpi_device = device;
1189 wblock->gblock = gblock[i];
1190
1191 retval = wmi_create_device(wmi_bus_dev, &gblock[i], wblock, device);
1192 if (retval) {
1193 kfree(wblock);
1194 continue;
1195 }
1196
1197 list_add_tail(&wblock->list, &wmi_block_list);
1198
1199 if (debug_event) {
1200 wblock->handler = wmi_notify_debug;
1201 wmi_method_enable(wblock, 1);
1202 }
1203 }
1204
1205 /*
1206 * Now that all of the devices are created, add them to the
1207 * device tree and probe subdrivers.
1208 */
1209 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1210 if (wblock->acpi_device != device)
1211 continue;
1212
1213 retval = device_add(&wblock->dev.dev);
1214 if (retval) {
1215 dev_err(wmi_bus_dev, "failed to register %pUL\n",
1216 wblock->gblock.guid);
1217 if (debug_event)
1218 wmi_method_enable(wblock, 0);
1219 list_del(&wblock->list);
1220 put_device(&wblock->dev.dev);
1221 }
1222 }
1223
1224out_free_pointer:
1225 kfree(out.pointer);
1226 return retval;
1227}
1228
1229/*
1230 * WMI can have EmbeddedControl access regions. In which case, we just want to
1231 * hand these off to the EC driver.
1232 */
1233static acpi_status
1234acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1235 u32 bits, u64 *value,
1236 void *handler_context, void *region_context)
1237{
1238 int result = 0, i = 0;
1239 u8 temp = 0;
1240
1241 if ((address > 0xFF) || !value)
1242 return AE_BAD_PARAMETER;
1243
1244 if (function != ACPI_READ && function != ACPI_WRITE)
1245 return AE_BAD_PARAMETER;
1246
1247 if (bits != 8)
1248 return AE_BAD_PARAMETER;
1249
1250 if (function == ACPI_READ) {
1251 result = ec_read(address, &temp);
1252 (*value) |= ((u64)temp) << i;
1253 } else {
1254 temp = 0xff & ((*value) >> i);
1255 result = ec_write(address, temp);
1256 }
1257
1258 switch (result) {
1259 case -EINVAL:
1260 return AE_BAD_PARAMETER;
1261 case -ENODEV:
1262 return AE_NOT_FOUND;
1263 case -ETIME:
1264 return AE_TIME;
1265 default:
1266 return AE_OK;
1267 }
1268}
1269
1270static void acpi_wmi_notify_handler(acpi_handle handle, u32 event,
1271 void *context)
1272{
1273 struct guid_block *block;
1274 struct wmi_block *wblock;
1275 bool found_it = false;
1276
1277 list_for_each_entry(wblock, &wmi_block_list, list) {
1278 block = &wblock->gblock;
1279
1280 if (wblock->acpi_device->handle == handle &&
1281 (block->flags & ACPI_WMI_EVENT) &&
1282 (block->notify_id == event))
1283 {
1284 found_it = true;
1285 break;
1286 }
1287 }
1288
1289 if (!found_it)
1290 return;
1291
1292 /* If a driver is bound, then notify the driver. */
1293 if (wblock->dev.dev.driver) {
1294 struct wmi_driver *driver;
1295 struct acpi_object_list input;
1296 union acpi_object params[1];
1297 struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL };
1298 acpi_status status;
1299
1300 driver = container_of(wblock->dev.dev.driver,
1301 struct wmi_driver, driver);
1302
1303 input.count = 1;
1304 input.pointer = params;
1305 params[0].type = ACPI_TYPE_INTEGER;
1306 params[0].integer.value = event;
1307
1308 status = acpi_evaluate_object(wblock->acpi_device->handle,
1309 "_WED", &input, &evdata);
1310 if (ACPI_FAILURE(status)) {
1311 dev_warn(&wblock->dev.dev,
1312 "failed to get event data\n");
1313 return;
1314 }
1315
1316 if (driver->notify)
1317 driver->notify(&wblock->dev,
1318 (union acpi_object *)evdata.pointer);
1319
1320 kfree(evdata.pointer);
1321 } else if (wblock->handler) {
1322 /* Legacy handler */
1323 wblock->handler(event, wblock->handler_data);
1324 }
1325
1326 if (debug_event)
1327 pr_info("DEBUG Event GUID: %pUL\n", wblock->gblock.guid);
1328
1329 acpi_bus_generate_netlink_event(
1330 wblock->acpi_device->pnp.device_class,
1331 dev_name(&wblock->dev.dev),
1332 event, 0);
1333
1334}
1335
1336static int acpi_wmi_remove(struct platform_device *device)
1337{
1338 struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev);
1339
1340 acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1341 acpi_wmi_notify_handler);
1342 acpi_remove_address_space_handler(acpi_device->handle,
1343 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
1344 wmi_free_devices(acpi_device);
1345 device_unregister((struct device *)dev_get_drvdata(&device->dev));
1346
1347 return 0;
1348}
1349
1350static int acpi_wmi_probe(struct platform_device *device)
1351{
1352 struct acpi_device *acpi_device;
1353 struct device *wmi_bus_dev;
1354 acpi_status status;
1355 int error;
1356
1357 acpi_device = ACPI_COMPANION(&device->dev);
1358 if (!acpi_device) {
1359 dev_err(&device->dev, "ACPI companion is missing\n");
1360 return -ENODEV;
1361 }
1362
1363 status = acpi_install_address_space_handler(acpi_device->handle,
1364 ACPI_ADR_SPACE_EC,
1365 &acpi_wmi_ec_space_handler,
1366 NULL, NULL);
1367 if (ACPI_FAILURE(status)) {
1368 dev_err(&device->dev, "Error installing EC region handler\n");
1369 return -ENODEV;
1370 }
1371
1372 status = acpi_install_notify_handler(acpi_device->handle,
1373 ACPI_DEVICE_NOTIFY,
1374 acpi_wmi_notify_handler,
1375 NULL);
1376 if (ACPI_FAILURE(status)) {
1377 dev_err(&device->dev, "Error installing notify handler\n");
1378 error = -ENODEV;
1379 goto err_remove_ec_handler;
1380 }
1381
1382 wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0),
1383 NULL, "wmi_bus-%s", dev_name(&device->dev));
1384 if (IS_ERR(wmi_bus_dev)) {
1385 error = PTR_ERR(wmi_bus_dev);
1386 goto err_remove_notify_handler;
1387 }
1388 dev_set_drvdata(&device->dev, wmi_bus_dev);
1389
1390 error = parse_wdg(wmi_bus_dev, acpi_device);
1391 if (error) {
1392 pr_err("Failed to parse WDG method\n");
1393 goto err_remove_busdev;
1394 }
1395
1396 return 0;
1397
1398err_remove_busdev:
1399 device_unregister(wmi_bus_dev);
1400
1401err_remove_notify_handler:
1402 acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1403 acpi_wmi_notify_handler);
1404
1405err_remove_ec_handler:
1406 acpi_remove_address_space_handler(acpi_device->handle,
1407 ACPI_ADR_SPACE_EC,
1408 &acpi_wmi_ec_space_handler);
1409
1410 return error;
1411}
1412
1413int __must_check __wmi_driver_register(struct wmi_driver *driver,
1414 struct module *owner)
1415{
1416 driver->driver.owner = owner;
1417 driver->driver.bus = &wmi_bus_type;
1418
1419 return driver_register(&driver->driver);
1420}
1421EXPORT_SYMBOL(__wmi_driver_register);
1422
1423void wmi_driver_unregister(struct wmi_driver *driver)
1424{
1425 driver_unregister(&driver->driver);
1426}
1427EXPORT_SYMBOL(wmi_driver_unregister);
1428
1429static int __init acpi_wmi_init(void)
1430{
1431 int error;
1432
1433 if (acpi_disabled)
1434 return -ENODEV;
1435
1436 error = class_register(&wmi_bus_class);
1437 if (error)
1438 return error;
1439
1440 error = bus_register(&wmi_bus_type);
1441 if (error)
1442 goto err_unreg_class;
1443
1444 error = platform_driver_register(&acpi_wmi_driver);
1445 if (error) {
1446 pr_err("Error loading mapper\n");
1447 goto err_unreg_bus;
1448 }
1449
1450 return 0;
1451
1452err_unreg_bus:
1453 bus_unregister(&wmi_bus_type);
1454
1455err_unreg_class:
1456 class_unregister(&wmi_bus_class);
1457
1458 return error;
1459}
1460
1461static void __exit acpi_wmi_exit(void)
1462{
1463 platform_driver_unregister(&acpi_wmi_driver);
1464 bus_unregister(&wmi_bus_type);
1465 class_unregister(&wmi_bus_class);
1466}
1467
1468subsys_initcall_sync(acpi_wmi_init);
1469module_exit(acpi_wmi_exit);
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
43ACPI_MODULE_NAME("wmi");
44MODULE_AUTHOR("Carlos Corbacho");
45MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
46MODULE_LICENSE("GPL");
47
48#define ACPI_WMI_CLASS "wmi"
49
50static DEFINE_MUTEX(wmi_data_lock);
51static LIST_HEAD(wmi_block_list);
52
53struct 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
66struct 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
85static bool debug_event;
86module_param(debug_event, bool, 0444);
87MODULE_PARM_DESC(debug_event,
88 "Log WMI Events [0/1]");
89
90static bool debug_dump_wdg;
91module_param(debug_dump_wdg, bool, 0444);
92MODULE_PARM_DESC(debug_dump_wdg,
93 "Dump available WMI interfaces [0/1]");
94
95static int acpi_wmi_remove(struct acpi_device *device, int type);
96static int acpi_wmi_add(struct acpi_device *device);
97static void acpi_wmi_notify(struct acpi_device *device, u32 event);
98
99static const struct acpi_device_id wmi_device_ids[] = {
100 {"PNP0C14", 0},
101 {"pnp0c14", 0},
102 {"", 0},
103};
104MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
105
106static 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 */
130static 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 */
154static 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 */
180static 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 */
203static 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
228static 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
251static 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 */
293acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
294u32 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}
341EXPORT_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 */
351acpi_status wmi_query_block(const char *guid_string, u8 instance,
352struct 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}
424EXPORT_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 */
434acpi_status wmi_set_block(const char *guid_string, u8 instance,
435const 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}
477EXPORT_SYMBOL_GPL(wmi_set_block);
478
479static 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
505static 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 */
549acpi_status wmi_install_notify_handler(const char *guid,
550wmi_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}
584EXPORT_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 */
591acpi_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}
630EXPORT_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 */
640acpi_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}
665EXPORT_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 */
673bool wmi_has_guid(const char *guid_string)
674{
675 return find_guid(guid_string, NULL);
676}
677EXPORT_SYMBOL_GPL(wmi_has_guid);
678
679/*
680 * sysfs interface
681 */
682static 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
697static struct device_attribute wmi_dev_attrs[] = {
698 __ATTR_RO(modalias),
699 __ATTR_NULL
700};
701
702static 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
724static 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
731static 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
738static 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
753static 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
767static 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 */
781static 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
842out_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 */
852static acpi_status
853acpi_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
892static 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
920static int acpi_wmi_remove(struct acpi_device *device, int type)
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
929static 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
955static 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
977static 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
985subsys_initcall(acpi_wmi_init);
986module_exit(acpi_wmi_exit);