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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
35ACPI_MODULE_NAME("wmi");
36MODULE_AUTHOR("Carlos Corbacho");
37MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
38MODULE_LICENSE("GPL");
39
40static LIST_HEAD(wmi_block_list);
41
42struct guid_block {
43 char guid[16];
44 union {
45 char object_id[2];
46 struct {
47 unsigned char notify_id;
48 unsigned char reserved;
49 };
50 };
51 u8 instance_count;
52 u8 flags;
53};
54
55struct wmi_block {
56 struct wmi_device dev;
57 struct list_head list;
58 struct guid_block gblock;
59 struct miscdevice char_dev;
60 struct mutex char_mutex;
61 struct acpi_device *acpi_device;
62 wmi_notify_handler handler;
63 void *handler_data;
64 u64 req_buf_size;
65
66 bool read_takes_no_args;
67};
68
69
70/*
71 * If the GUID data block is marked as expensive, we must enable and
72 * explicitily disable data collection.
73 */
74#define ACPI_WMI_EXPENSIVE 0x1
75#define ACPI_WMI_METHOD 0x2 /* GUID is a method */
76#define ACPI_WMI_STRING 0x4 /* GUID takes & returns a string */
77#define ACPI_WMI_EVENT 0x8 /* GUID is an event */
78
79static bool debug_event;
80module_param(debug_event, bool, 0444);
81MODULE_PARM_DESC(debug_event,
82 "Log WMI Events [0/1]");
83
84static bool debug_dump_wdg;
85module_param(debug_dump_wdg, bool, 0444);
86MODULE_PARM_DESC(debug_dump_wdg,
87 "Dump available WMI interfaces [0/1]");
88
89static int acpi_wmi_remove(struct platform_device *device);
90static int acpi_wmi_probe(struct platform_device *device);
91
92static const struct acpi_device_id wmi_device_ids[] = {
93 {"PNP0C14", 0},
94 {"pnp0c14", 0},
95 {"", 0},
96};
97MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
98
99static struct platform_driver acpi_wmi_driver = {
100 .driver = {
101 .name = "acpi-wmi",
102 .acpi_match_table = wmi_device_ids,
103 },
104 .probe = acpi_wmi_probe,
105 .remove = acpi_wmi_remove,
106};
107
108/*
109 * GUID parsing functions
110 */
111
112static bool find_guid(const char *guid_string, struct wmi_block **out)
113{
114 guid_t guid_input;
115 struct wmi_block *wblock;
116 struct guid_block *block;
117
118 if (guid_parse(guid_string, &guid_input))
119 return false;
120
121 list_for_each_entry(wblock, &wmi_block_list, list) {
122 block = &wblock->gblock;
123
124 if (memcmp(block->guid, &guid_input, 16) == 0) {
125 if (out)
126 *out = wblock;
127 return true;
128 }
129 }
130 return false;
131}
132
133static const void *find_guid_context(struct wmi_block *wblock,
134 struct wmi_driver *wdriver)
135{
136 const struct wmi_device_id *id;
137 guid_t guid_input;
138
139 if (wblock == NULL || wdriver == NULL)
140 return NULL;
141 if (wdriver->id_table == NULL)
142 return NULL;
143
144 id = wdriver->id_table;
145 while (*id->guid_string) {
146 if (guid_parse(id->guid_string, &guid_input))
147 continue;
148 if (!memcmp(wblock->gblock.guid, &guid_input, 16))
149 return id->context;
150 id++;
151 }
152 return NULL;
153}
154
155static int get_subobj_info(acpi_handle handle, const char *pathname,
156 struct acpi_device_info **info)
157{
158 struct acpi_device_info *dummy_info, **info_ptr;
159 acpi_handle subobj_handle;
160 acpi_status status;
161
162 status = acpi_get_handle(handle, (char *)pathname, &subobj_handle);
163 if (status == AE_NOT_FOUND)
164 return -ENOENT;
165 else if (ACPI_FAILURE(status))
166 return -EIO;
167
168 info_ptr = info ? info : &dummy_info;
169 status = acpi_get_object_info(subobj_handle, info_ptr);
170 if (ACPI_FAILURE(status))
171 return -EIO;
172
173 if (!info)
174 kfree(dummy_info);
175
176 return 0;
177}
178
179static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable)
180{
181 struct guid_block *block = NULL;
182 char method[5];
183 acpi_status status;
184 acpi_handle handle;
185
186 block = &wblock->gblock;
187 handle = wblock->acpi_device->handle;
188
189 snprintf(method, 5, "WE%02X", block->notify_id);
190 status = acpi_execute_simple_method(handle, method, enable);
191
192 if (status != AE_OK && status != AE_NOT_FOUND)
193 return status;
194 else
195 return AE_OK;
196}
197
198/*
199 * Exported WMI functions
200 */
201
202/**
203 * set_required_buffer_size - Sets the buffer size needed for performing IOCTL
204 * @wdev: A wmi bus device from a driver
205 * @length: Required buffer size
206 *
207 * Allocates memory needed for buffer, stores the buffer size in that memory
208 */
209int set_required_buffer_size(struct wmi_device *wdev, u64 length)
210{
211 struct wmi_block *wblock;
212
213 wblock = container_of(wdev, struct wmi_block, dev);
214 wblock->req_buf_size = length;
215
216 return 0;
217}
218EXPORT_SYMBOL_GPL(set_required_buffer_size);
219
220/**
221 * wmi_evaluate_method - Evaluate a WMI method
222 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
223 * @instance: Instance index
224 * @method_id: Method ID to call
225 * @in: Buffer containing input for the method call
226 * @out: Empty buffer to return the method results
227 *
228 * Call an ACPI-WMI method
229 */
230acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
231u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
232{
233 struct wmi_block *wblock = NULL;
234
235 if (!find_guid(guid_string, &wblock))
236 return AE_ERROR;
237 return wmidev_evaluate_method(&wblock->dev, instance, method_id,
238 in, out);
239}
240EXPORT_SYMBOL_GPL(wmi_evaluate_method);
241
242/**
243 * wmidev_evaluate_method - Evaluate a WMI method
244 * @wdev: A wmi bus device from a driver
245 * @instance: Instance index
246 * @method_id: Method ID to call
247 * @in: Buffer containing input for the method call
248 * @out: Empty buffer to return the method results
249 *
250 * Call an ACPI-WMI method
251 */
252acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance,
253 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
254{
255 struct guid_block *block = NULL;
256 struct wmi_block *wblock = NULL;
257 acpi_handle handle;
258 acpi_status status;
259 struct acpi_object_list input;
260 union acpi_object params[3];
261 char method[5] = "WM";
262
263 wblock = container_of(wdev, struct wmi_block, dev);
264 block = &wblock->gblock;
265 handle = wblock->acpi_device->handle;
266
267 if (!(block->flags & ACPI_WMI_METHOD))
268 return AE_BAD_DATA;
269
270 if (block->instance_count <= instance)
271 return AE_BAD_PARAMETER;
272
273 input.count = 2;
274 input.pointer = params;
275 params[0].type = ACPI_TYPE_INTEGER;
276 params[0].integer.value = instance;
277 params[1].type = ACPI_TYPE_INTEGER;
278 params[1].integer.value = method_id;
279
280 if (in) {
281 input.count = 3;
282
283 if (block->flags & ACPI_WMI_STRING) {
284 params[2].type = ACPI_TYPE_STRING;
285 } else {
286 params[2].type = ACPI_TYPE_BUFFER;
287 }
288 params[2].buffer.length = in->length;
289 params[2].buffer.pointer = in->pointer;
290 }
291
292 strncat(method, block->object_id, 2);
293
294 status = acpi_evaluate_object(handle, method, &input, out);
295
296 return status;
297}
298EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
299
300static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
301 struct acpi_buffer *out)
302{
303 struct guid_block *block = NULL;
304 acpi_handle handle;
305 acpi_status status, wc_status = AE_ERROR;
306 struct acpi_object_list input;
307 union acpi_object wq_params[1];
308 char method[5];
309 char wc_method[5] = "WC";
310
311 if (!out)
312 return AE_BAD_PARAMETER;
313
314 block = &wblock->gblock;
315 handle = wblock->acpi_device->handle;
316
317 if (block->instance_count <= instance)
318 return AE_BAD_PARAMETER;
319
320 /* Check GUID is a data block */
321 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
322 return AE_ERROR;
323
324 input.count = 1;
325 input.pointer = wq_params;
326 wq_params[0].type = ACPI_TYPE_INTEGER;
327 wq_params[0].integer.value = instance;
328
329 if (instance == 0 && wblock->read_takes_no_args)
330 input.count = 0;
331
332 /*
333 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
334 * enable collection.
335 */
336 if (block->flags & ACPI_WMI_EXPENSIVE) {
337 strncat(wc_method, block->object_id, 2);
338
339 /*
340 * Some GUIDs break the specification by declaring themselves
341 * expensive, but have no corresponding WCxx method. So we
342 * should not fail if this happens.
343 */
344 wc_status = acpi_execute_simple_method(handle, wc_method, 1);
345 }
346
347 strcpy(method, "WQ");
348 strncat(method, block->object_id, 2);
349
350 status = acpi_evaluate_object(handle, method, &input, out);
351
352 /*
353 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
354 * the WQxx method failed - we should disable collection anyway.
355 */
356 if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
357 status = acpi_execute_simple_method(handle, wc_method, 0);
358 }
359
360 return status;
361}
362
363/**
364 * wmi_query_block - Return contents of a WMI block (deprecated)
365 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
366 * @instance: Instance index
367 * @out: Empty buffer to return the contents of the data block to
368 *
369 * Return the contents of an ACPI-WMI data block to a buffer
370 */
371acpi_status wmi_query_block(const char *guid_string, u8 instance,
372 struct acpi_buffer *out)
373{
374 struct wmi_block *wblock;
375
376 if (!guid_string)
377 return AE_BAD_PARAMETER;
378
379 if (!find_guid(guid_string, &wblock))
380 return AE_ERROR;
381
382 return __query_block(wblock, instance, out);
383}
384EXPORT_SYMBOL_GPL(wmi_query_block);
385
386union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
387{
388 struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
389 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
390
391 if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
392 return NULL;
393
394 return (union acpi_object *)out.pointer;
395}
396EXPORT_SYMBOL_GPL(wmidev_block_query);
397
398/**
399 * wmi_set_block - Write to a WMI block
400 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
401 * @instance: Instance index
402 * @in: Buffer containing new values for the data block
403 *
404 * Write the contents of the input buffer to an ACPI-WMI data block
405 */
406acpi_status wmi_set_block(const char *guid_string, u8 instance,
407 const struct acpi_buffer *in)
408{
409 struct guid_block *block = NULL;
410 struct wmi_block *wblock = NULL;
411 acpi_handle handle;
412 struct acpi_object_list input;
413 union acpi_object params[2];
414 char method[5] = "WS";
415
416 if (!guid_string || !in)
417 return AE_BAD_DATA;
418
419 if (!find_guid(guid_string, &wblock))
420 return AE_ERROR;
421
422 block = &wblock->gblock;
423 handle = wblock->acpi_device->handle;
424
425 if (block->instance_count <= instance)
426 return AE_BAD_PARAMETER;
427
428 /* Check GUID is a data block */
429 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
430 return AE_ERROR;
431
432 input.count = 2;
433 input.pointer = params;
434 params[0].type = ACPI_TYPE_INTEGER;
435 params[0].integer.value = instance;
436
437 if (block->flags & ACPI_WMI_STRING) {
438 params[1].type = ACPI_TYPE_STRING;
439 } else {
440 params[1].type = ACPI_TYPE_BUFFER;
441 }
442 params[1].buffer.length = in->length;
443 params[1].buffer.pointer = in->pointer;
444
445 strncat(method, block->object_id, 2);
446
447 return acpi_evaluate_object(handle, method, &input, NULL);
448}
449EXPORT_SYMBOL_GPL(wmi_set_block);
450
451static void wmi_dump_wdg(const struct guid_block *g)
452{
453 pr_info("%pUL:\n", g->guid);
454 if (g->flags & ACPI_WMI_EVENT)
455 pr_info("\tnotify_id: 0x%02X\n", g->notify_id);
456 else
457 pr_info("\tobject_id: %2pE\n", g->object_id);
458 pr_info("\tinstance_count: %d\n", g->instance_count);
459 pr_info("\tflags: %#x", g->flags);
460 if (g->flags) {
461 if (g->flags & ACPI_WMI_EXPENSIVE)
462 pr_cont(" ACPI_WMI_EXPENSIVE");
463 if (g->flags & ACPI_WMI_METHOD)
464 pr_cont(" ACPI_WMI_METHOD");
465 if (g->flags & ACPI_WMI_STRING)
466 pr_cont(" ACPI_WMI_STRING");
467 if (g->flags & ACPI_WMI_EVENT)
468 pr_cont(" ACPI_WMI_EVENT");
469 }
470 pr_cont("\n");
471
472}
473
474static void wmi_notify_debug(u32 value, void *context)
475{
476 struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
477 union acpi_object *obj;
478 acpi_status status;
479
480 status = wmi_get_event_data(value, &response);
481 if (status != AE_OK) {
482 pr_info("bad event status 0x%x\n", status);
483 return;
484 }
485
486 obj = (union acpi_object *)response.pointer;
487
488 if (!obj)
489 return;
490
491 pr_info("DEBUG Event ");
492 switch(obj->type) {
493 case ACPI_TYPE_BUFFER:
494 pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
495 break;
496 case ACPI_TYPE_STRING:
497 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
498 break;
499 case ACPI_TYPE_INTEGER:
500 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
501 break;
502 case ACPI_TYPE_PACKAGE:
503 pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
504 break;
505 default:
506 pr_cont("object type 0x%X\n", obj->type);
507 }
508 kfree(obj);
509}
510
511/**
512 * wmi_install_notify_handler - Register handler for WMI events
513 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
514 * @handler: Function to handle notifications
515 * @data: Data to be returned to handler when event is fired
516 *
517 * Register a handler for events sent to the ACPI-WMI mapper device.
518 */
519acpi_status wmi_install_notify_handler(const char *guid,
520wmi_notify_handler handler, void *data)
521{
522 struct wmi_block *block;
523 acpi_status status = AE_NOT_EXIST;
524 guid_t guid_input;
525
526 if (!guid || !handler)
527 return AE_BAD_PARAMETER;
528
529 if (guid_parse(guid, &guid_input))
530 return AE_BAD_PARAMETER;
531
532 list_for_each_entry(block, &wmi_block_list, list) {
533 acpi_status wmi_status;
534
535 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
536 if (block->handler &&
537 block->handler != wmi_notify_debug)
538 return AE_ALREADY_ACQUIRED;
539
540 block->handler = handler;
541 block->handler_data = data;
542
543 wmi_status = wmi_method_enable(block, 1);
544 if ((wmi_status != AE_OK) ||
545 ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
546 status = wmi_status;
547 }
548 }
549
550 return status;
551}
552EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
553
554/**
555 * wmi_uninstall_notify_handler - Unregister handler for WMI events
556 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
557 *
558 * Unregister handler for events sent to the ACPI-WMI mapper device.
559 */
560acpi_status wmi_remove_notify_handler(const char *guid)
561{
562 struct wmi_block *block;
563 acpi_status status = AE_NOT_EXIST;
564 guid_t guid_input;
565
566 if (!guid)
567 return AE_BAD_PARAMETER;
568
569 if (guid_parse(guid, &guid_input))
570 return AE_BAD_PARAMETER;
571
572 list_for_each_entry(block, &wmi_block_list, list) {
573 acpi_status wmi_status;
574
575 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
576 if (!block->handler ||
577 block->handler == wmi_notify_debug)
578 return AE_NULL_ENTRY;
579
580 if (debug_event) {
581 block->handler = wmi_notify_debug;
582 status = AE_OK;
583 } else {
584 wmi_status = wmi_method_enable(block, 0);
585 block->handler = NULL;
586 block->handler_data = NULL;
587 if ((wmi_status != AE_OK) ||
588 ((wmi_status == AE_OK) &&
589 (status == AE_NOT_EXIST)))
590 status = wmi_status;
591 }
592 }
593 }
594
595 return status;
596}
597EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
598
599/**
600 * wmi_get_event_data - Get WMI data associated with an event
601 *
602 * @event: Event to find
603 * @out: Buffer to hold event data. out->pointer should be freed with kfree()
604 *
605 * Returns extra data associated with an event in WMI.
606 */
607acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
608{
609 struct acpi_object_list input;
610 union acpi_object params[1];
611 struct guid_block *gblock;
612 struct wmi_block *wblock;
613
614 input.count = 1;
615 input.pointer = params;
616 params[0].type = ACPI_TYPE_INTEGER;
617 params[0].integer.value = event;
618
619 list_for_each_entry(wblock, &wmi_block_list, list) {
620 gblock = &wblock->gblock;
621
622 if ((gblock->flags & ACPI_WMI_EVENT) &&
623 (gblock->notify_id == event))
624 return acpi_evaluate_object(wblock->acpi_device->handle,
625 "_WED", &input, out);
626 }
627
628 return AE_NOT_FOUND;
629}
630EXPORT_SYMBOL_GPL(wmi_get_event_data);
631
632/**
633 * wmi_has_guid - Check if a GUID is available
634 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
635 *
636 * Check if a given GUID is defined by _WDG
637 */
638bool wmi_has_guid(const char *guid_string)
639{
640 return find_guid(guid_string, NULL);
641}
642EXPORT_SYMBOL_GPL(wmi_has_guid);
643
644/**
645 * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID
646 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
647 *
648 * Find the _UID of ACPI device associated with this WMI GUID.
649 *
650 * Return: The ACPI _UID field value or NULL if the WMI GUID was not found
651 */
652char *wmi_get_acpi_device_uid(const char *guid_string)
653{
654 struct wmi_block *wblock = NULL;
655
656 if (!find_guid(guid_string, &wblock))
657 return NULL;
658
659 return acpi_device_uid(wblock->acpi_device);
660}
661EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
662
663static struct wmi_block *dev_to_wblock(struct device *dev)
664{
665 return container_of(dev, struct wmi_block, dev.dev);
666}
667
668static struct wmi_device *dev_to_wdev(struct device *dev)
669{
670 return container_of(dev, struct wmi_device, dev);
671}
672
673/*
674 * sysfs interface
675 */
676static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
677 char *buf)
678{
679 struct wmi_block *wblock = dev_to_wblock(dev);
680
681 return sprintf(buf, "wmi:%pUL\n", wblock->gblock.guid);
682}
683static DEVICE_ATTR_RO(modalias);
684
685static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
686 char *buf)
687{
688 struct wmi_block *wblock = dev_to_wblock(dev);
689
690 return sprintf(buf, "%pUL\n", wblock->gblock.guid);
691}
692static DEVICE_ATTR_RO(guid);
693
694static ssize_t instance_count_show(struct device *dev,
695 struct device_attribute *attr, char *buf)
696{
697 struct wmi_block *wblock = dev_to_wblock(dev);
698
699 return sprintf(buf, "%d\n", (int)wblock->gblock.instance_count);
700}
701static DEVICE_ATTR_RO(instance_count);
702
703static ssize_t expensive_show(struct device *dev,
704 struct device_attribute *attr, char *buf)
705{
706 struct wmi_block *wblock = dev_to_wblock(dev);
707
708 return sprintf(buf, "%d\n",
709 (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
710}
711static DEVICE_ATTR_RO(expensive);
712
713static struct attribute *wmi_attrs[] = {
714 &dev_attr_modalias.attr,
715 &dev_attr_guid.attr,
716 &dev_attr_instance_count.attr,
717 &dev_attr_expensive.attr,
718 NULL,
719};
720ATTRIBUTE_GROUPS(wmi);
721
722static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
723 char *buf)
724{
725 struct wmi_block *wblock = dev_to_wblock(dev);
726
727 return sprintf(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
728}
729static DEVICE_ATTR_RO(notify_id);
730
731static struct attribute *wmi_event_attrs[] = {
732 &dev_attr_notify_id.attr,
733 NULL,
734};
735ATTRIBUTE_GROUPS(wmi_event);
736
737static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
738 char *buf)
739{
740 struct wmi_block *wblock = dev_to_wblock(dev);
741
742 return sprintf(buf, "%c%c\n", wblock->gblock.object_id[0],
743 wblock->gblock.object_id[1]);
744}
745static DEVICE_ATTR_RO(object_id);
746
747static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
748 char *buf)
749{
750 struct wmi_device *wdev = dev_to_wdev(dev);
751
752 return sprintf(buf, "%d\n", (int)wdev->setable);
753}
754static DEVICE_ATTR_RO(setable);
755
756static struct attribute *wmi_data_attrs[] = {
757 &dev_attr_object_id.attr,
758 &dev_attr_setable.attr,
759 NULL,
760};
761ATTRIBUTE_GROUPS(wmi_data);
762
763static struct attribute *wmi_method_attrs[] = {
764 &dev_attr_object_id.attr,
765 NULL,
766};
767ATTRIBUTE_GROUPS(wmi_method);
768
769static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
770{
771 struct wmi_block *wblock = dev_to_wblock(dev);
772
773 if (add_uevent_var(env, "MODALIAS=wmi:%pUL", wblock->gblock.guid))
774 return -ENOMEM;
775
776 if (add_uevent_var(env, "WMI_GUID=%pUL", wblock->gblock.guid))
777 return -ENOMEM;
778
779 return 0;
780}
781
782static void wmi_dev_release(struct device *dev)
783{
784 struct wmi_block *wblock = dev_to_wblock(dev);
785
786 kfree(wblock);
787}
788
789static int wmi_dev_match(struct device *dev, struct device_driver *driver)
790{
791 struct wmi_driver *wmi_driver =
792 container_of(driver, struct wmi_driver, driver);
793 struct wmi_block *wblock = dev_to_wblock(dev);
794 const struct wmi_device_id *id = wmi_driver->id_table;
795
796 if (id == NULL)
797 return 0;
798
799 while (*id->guid_string) {
800 guid_t driver_guid;
801
802 if (WARN_ON(guid_parse(id->guid_string, &driver_guid)))
803 continue;
804 if (!memcmp(&driver_guid, wblock->gblock.guid, 16))
805 return 1;
806
807 id++;
808 }
809
810 return 0;
811}
812static int wmi_char_open(struct inode *inode, struct file *filp)
813{
814 const char *driver_name = filp->f_path.dentry->d_iname;
815 struct wmi_block *wblock = NULL;
816 struct wmi_block *next = NULL;
817
818 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
819 if (!wblock->dev.dev.driver)
820 continue;
821 if (strcmp(driver_name, wblock->dev.dev.driver->name) == 0) {
822 filp->private_data = wblock;
823 break;
824 }
825 }
826
827 if (!filp->private_data)
828 return -ENODEV;
829
830 return nonseekable_open(inode, filp);
831}
832
833static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
834 size_t length, loff_t *offset)
835{
836 struct wmi_block *wblock = filp->private_data;
837
838 return simple_read_from_buffer(buffer, length, offset,
839 &wblock->req_buf_size,
840 sizeof(wblock->req_buf_size));
841}
842
843static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
844{
845 struct wmi_ioctl_buffer __user *input =
846 (struct wmi_ioctl_buffer __user *) arg;
847 struct wmi_block *wblock = filp->private_data;
848 struct wmi_ioctl_buffer *buf = NULL;
849 struct wmi_driver *wdriver = NULL;
850 int ret;
851
852 if (_IOC_TYPE(cmd) != WMI_IOC)
853 return -ENOTTY;
854
855 /* make sure we're not calling a higher instance than exists*/
856 if (_IOC_NR(cmd) >= wblock->gblock.instance_count)
857 return -EINVAL;
858
859 mutex_lock(&wblock->char_mutex);
860 buf = wblock->handler_data;
861 if (get_user(buf->length, &input->length)) {
862 dev_dbg(&wblock->dev.dev, "Read length from user failed\n");
863 ret = -EFAULT;
864 goto out_ioctl;
865 }
866 /* if it's too small, abort */
867 if (buf->length < wblock->req_buf_size) {
868 dev_err(&wblock->dev.dev,
869 "Buffer %lld too small, need at least %lld\n",
870 buf->length, wblock->req_buf_size);
871 ret = -EINVAL;
872 goto out_ioctl;
873 }
874 /* if it's too big, warn, driver will only use what is needed */
875 if (buf->length > wblock->req_buf_size)
876 dev_warn(&wblock->dev.dev,
877 "Buffer %lld is bigger than required %lld\n",
878 buf->length, wblock->req_buf_size);
879
880 /* copy the structure from userspace */
881 if (copy_from_user(buf, input, wblock->req_buf_size)) {
882 dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n",
883 wblock->req_buf_size);
884 ret = -EFAULT;
885 goto out_ioctl;
886 }
887
888 /* let the driver do any filtering and do the call */
889 wdriver = container_of(wblock->dev.dev.driver,
890 struct wmi_driver, driver);
891 if (!try_module_get(wdriver->driver.owner)) {
892 ret = -EBUSY;
893 goto out_ioctl;
894 }
895 ret = wdriver->filter_callback(&wblock->dev, cmd, buf);
896 module_put(wdriver->driver.owner);
897 if (ret)
898 goto out_ioctl;
899
900 /* return the result (only up to our internal buffer size) */
901 if (copy_to_user(input, buf, wblock->req_buf_size)) {
902 dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n",
903 wblock->req_buf_size);
904 ret = -EFAULT;
905 }
906
907out_ioctl:
908 mutex_unlock(&wblock->char_mutex);
909 return ret;
910}
911
912static const struct file_operations wmi_fops = {
913 .owner = THIS_MODULE,
914 .read = wmi_char_read,
915 .open = wmi_char_open,
916 .unlocked_ioctl = wmi_ioctl,
917 .compat_ioctl = compat_ptr_ioctl,
918};
919
920static int wmi_dev_probe(struct device *dev)
921{
922 struct wmi_block *wblock = dev_to_wblock(dev);
923 struct wmi_driver *wdriver =
924 container_of(dev->driver, struct wmi_driver, driver);
925 int ret = 0;
926 char *buf;
927
928 if (ACPI_FAILURE(wmi_method_enable(wblock, 1)))
929 dev_warn(dev, "failed to enable device -- probing anyway\n");
930
931 if (wdriver->probe) {
932 ret = wdriver->probe(dev_to_wdev(dev),
933 find_guid_context(wblock, wdriver));
934 if (ret != 0)
935 goto probe_failure;
936 }
937
938 /* driver wants a character device made */
939 if (wdriver->filter_callback) {
940 /* check that required buffer size declared by driver or MOF */
941 if (!wblock->req_buf_size) {
942 dev_err(&wblock->dev.dev,
943 "Required buffer size not set\n");
944 ret = -EINVAL;
945 goto probe_failure;
946 }
947
948 wblock->handler_data = kmalloc(wblock->req_buf_size,
949 GFP_KERNEL);
950 if (!wblock->handler_data) {
951 ret = -ENOMEM;
952 goto probe_failure;
953 }
954
955 buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name);
956 if (!buf) {
957 ret = -ENOMEM;
958 goto probe_string_failure;
959 }
960 wblock->char_dev.minor = MISC_DYNAMIC_MINOR;
961 wblock->char_dev.name = buf;
962 wblock->char_dev.fops = &wmi_fops;
963 wblock->char_dev.mode = 0444;
964 ret = misc_register(&wblock->char_dev);
965 if (ret) {
966 dev_warn(dev, "failed to register char dev: %d\n", ret);
967 ret = -ENOMEM;
968 goto probe_misc_failure;
969 }
970 }
971
972 return 0;
973
974probe_misc_failure:
975 kfree(buf);
976probe_string_failure:
977 kfree(wblock->handler_data);
978probe_failure:
979 if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
980 dev_warn(dev, "failed to disable device\n");
981 return ret;
982}
983
984static int wmi_dev_remove(struct device *dev)
985{
986 struct wmi_block *wblock = dev_to_wblock(dev);
987 struct wmi_driver *wdriver =
988 container_of(dev->driver, struct wmi_driver, driver);
989 int ret = 0;
990
991 if (wdriver->filter_callback) {
992 misc_deregister(&wblock->char_dev);
993 kfree(wblock->char_dev.name);
994 kfree(wblock->handler_data);
995 }
996
997 if (wdriver->remove)
998 ret = wdriver->remove(dev_to_wdev(dev));
999
1000 if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
1001 dev_warn(dev, "failed to disable device\n");
1002
1003 return ret;
1004}
1005
1006static struct class wmi_bus_class = {
1007 .name = "wmi_bus",
1008};
1009
1010static struct bus_type wmi_bus_type = {
1011 .name = "wmi",
1012 .dev_groups = wmi_groups,
1013 .match = wmi_dev_match,
1014 .uevent = wmi_dev_uevent,
1015 .probe = wmi_dev_probe,
1016 .remove = wmi_dev_remove,
1017};
1018
1019static const struct device_type wmi_type_event = {
1020 .name = "event",
1021 .groups = wmi_event_groups,
1022 .release = wmi_dev_release,
1023};
1024
1025static const struct device_type wmi_type_method = {
1026 .name = "method",
1027 .groups = wmi_method_groups,
1028 .release = wmi_dev_release,
1029};
1030
1031static const struct device_type wmi_type_data = {
1032 .name = "data",
1033 .groups = wmi_data_groups,
1034 .release = wmi_dev_release,
1035};
1036
1037static int wmi_create_device(struct device *wmi_bus_dev,
1038 const struct guid_block *gblock,
1039 struct wmi_block *wblock,
1040 struct acpi_device *device)
1041{
1042 struct acpi_device_info *info;
1043 char method[5];
1044 int result;
1045
1046 if (gblock->flags & ACPI_WMI_EVENT) {
1047 wblock->dev.dev.type = &wmi_type_event;
1048 goto out_init;
1049 }
1050
1051 if (gblock->flags & ACPI_WMI_METHOD) {
1052 wblock->dev.dev.type = &wmi_type_method;
1053 mutex_init(&wblock->char_mutex);
1054 goto out_init;
1055 }
1056
1057 /*
1058 * Data Block Query Control Method (WQxx by convention) is
1059 * required per the WMI documentation. If it is not present,
1060 * we ignore this data block.
1061 */
1062 strcpy(method, "WQ");
1063 strncat(method, wblock->gblock.object_id, 2);
1064 result = get_subobj_info(device->handle, method, &info);
1065
1066 if (result) {
1067 dev_warn(wmi_bus_dev,
1068 "%s data block query control method not found\n",
1069 method);
1070 return result;
1071 }
1072
1073 wblock->dev.dev.type = &wmi_type_data;
1074
1075 /*
1076 * The Microsoft documentation specifically states:
1077 *
1078 * Data blocks registered with only a single instance
1079 * can ignore the parameter.
1080 *
1081 * ACPICA will get mad at us if we call the method with the wrong number
1082 * of arguments, so check what our method expects. (On some Dell
1083 * laptops, WQxx may not be a method at all.)
1084 */
1085 if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1086 wblock->read_takes_no_args = true;
1087
1088 kfree(info);
1089
1090 strcpy(method, "WS");
1091 strncat(method, wblock->gblock.object_id, 2);
1092 result = get_subobj_info(device->handle, method, NULL);
1093
1094 if (result == 0)
1095 wblock->dev.setable = true;
1096
1097 out_init:
1098 wblock->dev.dev.bus = &wmi_bus_type;
1099 wblock->dev.dev.parent = wmi_bus_dev;
1100
1101 dev_set_name(&wblock->dev.dev, "%pUL", gblock->guid);
1102
1103 device_initialize(&wblock->dev.dev);
1104
1105 return 0;
1106}
1107
1108static void wmi_free_devices(struct acpi_device *device)
1109{
1110 struct wmi_block *wblock, *next;
1111
1112 /* Delete devices for all the GUIDs */
1113 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1114 if (wblock->acpi_device == device) {
1115 list_del(&wblock->list);
1116 device_unregister(&wblock->dev.dev);
1117 }
1118 }
1119}
1120
1121static bool guid_already_parsed(struct acpi_device *device, const u8 *guid)
1122{
1123 struct wmi_block *wblock;
1124
1125 list_for_each_entry(wblock, &wmi_block_list, list) {
1126 if (memcmp(wblock->gblock.guid, guid, 16) == 0) {
1127 /*
1128 * Because we historically didn't track the relationship
1129 * between GUIDs and ACPI nodes, we don't know whether
1130 * we need to suppress GUIDs that are unique on a
1131 * given node but duplicated across nodes.
1132 */
1133 dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
1134 guid, dev_name(&wblock->acpi_device->dev));
1135 return true;
1136 }
1137 }
1138
1139 return false;
1140}
1141
1142/*
1143 * Parse the _WDG method for the GUID data blocks
1144 */
1145static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
1146{
1147 struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1148 const struct guid_block *gblock;
1149 struct wmi_block *wblock, *next;
1150 union acpi_object *obj;
1151 acpi_status status;
1152 int retval = 0;
1153 u32 i, total;
1154
1155 status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1156 if (ACPI_FAILURE(status))
1157 return -ENXIO;
1158
1159 obj = (union acpi_object *) out.pointer;
1160 if (!obj)
1161 return -ENXIO;
1162
1163 if (obj->type != ACPI_TYPE_BUFFER) {
1164 retval = -ENXIO;
1165 goto out_free_pointer;
1166 }
1167
1168 gblock = (const struct guid_block *)obj->buffer.pointer;
1169 total = obj->buffer.length / sizeof(struct guid_block);
1170
1171 for (i = 0; i < total; i++) {
1172 if (debug_dump_wdg)
1173 wmi_dump_wdg(&gblock[i]);
1174
1175 /*
1176 * Some WMI devices, like those for nVidia hooks, have a
1177 * duplicate GUID. It's not clear what we should do in this
1178 * case yet, so for now, we'll just ignore the duplicate
1179 * for device creation.
1180 */
1181 if (guid_already_parsed(device, gblock[i].guid))
1182 continue;
1183
1184 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
1185 if (!wblock) {
1186 retval = -ENOMEM;
1187 break;
1188 }
1189
1190 wblock->acpi_device = device;
1191 wblock->gblock = gblock[i];
1192
1193 retval = wmi_create_device(wmi_bus_dev, &gblock[i], wblock, device);
1194 if (retval) {
1195 kfree(wblock);
1196 continue;
1197 }
1198
1199 list_add_tail(&wblock->list, &wmi_block_list);
1200
1201 if (debug_event) {
1202 wblock->handler = wmi_notify_debug;
1203 wmi_method_enable(wblock, 1);
1204 }
1205 }
1206
1207 /*
1208 * Now that all of the devices are created, add them to the
1209 * device tree and probe subdrivers.
1210 */
1211 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1212 if (wblock->acpi_device != device)
1213 continue;
1214
1215 retval = device_add(&wblock->dev.dev);
1216 if (retval) {
1217 dev_err(wmi_bus_dev, "failed to register %pUL\n",
1218 wblock->gblock.guid);
1219 if (debug_event)
1220 wmi_method_enable(wblock, 0);
1221 list_del(&wblock->list);
1222 put_device(&wblock->dev.dev);
1223 }
1224 }
1225
1226out_free_pointer:
1227 kfree(out.pointer);
1228 return retval;
1229}
1230
1231/*
1232 * WMI can have EmbeddedControl access regions. In which case, we just want to
1233 * hand these off to the EC driver.
1234 */
1235static acpi_status
1236acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1237 u32 bits, u64 *value,
1238 void *handler_context, void *region_context)
1239{
1240 int result = 0, i = 0;
1241 u8 temp = 0;
1242
1243 if ((address > 0xFF) || !value)
1244 return AE_BAD_PARAMETER;
1245
1246 if (function != ACPI_READ && function != ACPI_WRITE)
1247 return AE_BAD_PARAMETER;
1248
1249 if (bits != 8)
1250 return AE_BAD_PARAMETER;
1251
1252 if (function == ACPI_READ) {
1253 result = ec_read(address, &temp);
1254 (*value) |= ((u64)temp) << i;
1255 } else {
1256 temp = 0xff & ((*value) >> i);
1257 result = ec_write(address, temp);
1258 }
1259
1260 switch (result) {
1261 case -EINVAL:
1262 return AE_BAD_PARAMETER;
1263 break;
1264 case -ENODEV:
1265 return AE_NOT_FOUND;
1266 break;
1267 case -ETIME:
1268 return AE_TIME;
1269 break;
1270 default:
1271 return AE_OK;
1272 }
1273}
1274
1275static void acpi_wmi_notify_handler(acpi_handle handle, u32 event,
1276 void *context)
1277{
1278 struct guid_block *block;
1279 struct wmi_block *wblock;
1280 bool found_it = false;
1281
1282 list_for_each_entry(wblock, &wmi_block_list, list) {
1283 block = &wblock->gblock;
1284
1285 if (wblock->acpi_device->handle == handle &&
1286 (block->flags & ACPI_WMI_EVENT) &&
1287 (block->notify_id == event))
1288 {
1289 found_it = true;
1290 break;
1291 }
1292 }
1293
1294 if (!found_it)
1295 return;
1296
1297 /* If a driver is bound, then notify the driver. */
1298 if (wblock->dev.dev.driver) {
1299 struct wmi_driver *driver;
1300 struct acpi_object_list input;
1301 union acpi_object params[1];
1302 struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL };
1303 acpi_status status;
1304
1305 driver = container_of(wblock->dev.dev.driver,
1306 struct wmi_driver, driver);
1307
1308 input.count = 1;
1309 input.pointer = params;
1310 params[0].type = ACPI_TYPE_INTEGER;
1311 params[0].integer.value = event;
1312
1313 status = acpi_evaluate_object(wblock->acpi_device->handle,
1314 "_WED", &input, &evdata);
1315 if (ACPI_FAILURE(status)) {
1316 dev_warn(&wblock->dev.dev,
1317 "failed to get event data\n");
1318 return;
1319 }
1320
1321 if (driver->notify)
1322 driver->notify(&wblock->dev,
1323 (union acpi_object *)evdata.pointer);
1324
1325 kfree(evdata.pointer);
1326 } else if (wblock->handler) {
1327 /* Legacy handler */
1328 wblock->handler(event, wblock->handler_data);
1329 }
1330
1331 if (debug_event)
1332 pr_info("DEBUG Event GUID: %pUL\n", wblock->gblock.guid);
1333
1334 acpi_bus_generate_netlink_event(
1335 wblock->acpi_device->pnp.device_class,
1336 dev_name(&wblock->dev.dev),
1337 event, 0);
1338
1339}
1340
1341static int acpi_wmi_remove(struct platform_device *device)
1342{
1343 struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev);
1344
1345 acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1346 acpi_wmi_notify_handler);
1347 acpi_remove_address_space_handler(acpi_device->handle,
1348 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
1349 wmi_free_devices(acpi_device);
1350 device_destroy(&wmi_bus_class, MKDEV(0, 0));
1351
1352 return 0;
1353}
1354
1355static int acpi_wmi_probe(struct platform_device *device)
1356{
1357 struct acpi_device *acpi_device;
1358 struct device *wmi_bus_dev;
1359 acpi_status status;
1360 int error;
1361
1362 acpi_device = ACPI_COMPANION(&device->dev);
1363 if (!acpi_device) {
1364 dev_err(&device->dev, "ACPI companion is missing\n");
1365 return -ENODEV;
1366 }
1367
1368 status = acpi_install_address_space_handler(acpi_device->handle,
1369 ACPI_ADR_SPACE_EC,
1370 &acpi_wmi_ec_space_handler,
1371 NULL, NULL);
1372 if (ACPI_FAILURE(status)) {
1373 dev_err(&device->dev, "Error installing EC region handler\n");
1374 return -ENODEV;
1375 }
1376
1377 status = acpi_install_notify_handler(acpi_device->handle,
1378 ACPI_DEVICE_NOTIFY,
1379 acpi_wmi_notify_handler,
1380 NULL);
1381 if (ACPI_FAILURE(status)) {
1382 dev_err(&device->dev, "Error installing notify handler\n");
1383 error = -ENODEV;
1384 goto err_remove_ec_handler;
1385 }
1386
1387 wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0),
1388 NULL, "wmi_bus-%s", dev_name(&device->dev));
1389 if (IS_ERR(wmi_bus_dev)) {
1390 error = PTR_ERR(wmi_bus_dev);
1391 goto err_remove_notify_handler;
1392 }
1393 dev_set_drvdata(&device->dev, wmi_bus_dev);
1394
1395 error = parse_wdg(wmi_bus_dev, acpi_device);
1396 if (error) {
1397 pr_err("Failed to parse WDG method\n");
1398 goto err_remove_busdev;
1399 }
1400
1401 return 0;
1402
1403err_remove_busdev:
1404 device_destroy(&wmi_bus_class, MKDEV(0, 0));
1405
1406err_remove_notify_handler:
1407 acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1408 acpi_wmi_notify_handler);
1409
1410err_remove_ec_handler:
1411 acpi_remove_address_space_handler(acpi_device->handle,
1412 ACPI_ADR_SPACE_EC,
1413 &acpi_wmi_ec_space_handler);
1414
1415 return error;
1416}
1417
1418int __must_check __wmi_driver_register(struct wmi_driver *driver,
1419 struct module *owner)
1420{
1421 driver->driver.owner = owner;
1422 driver->driver.bus = &wmi_bus_type;
1423
1424 return driver_register(&driver->driver);
1425}
1426EXPORT_SYMBOL(__wmi_driver_register);
1427
1428void wmi_driver_unregister(struct wmi_driver *driver)
1429{
1430 driver_unregister(&driver->driver);
1431}
1432EXPORT_SYMBOL(wmi_driver_unregister);
1433
1434static int __init acpi_wmi_init(void)
1435{
1436 int error;
1437
1438 if (acpi_disabled)
1439 return -ENODEV;
1440
1441 error = class_register(&wmi_bus_class);
1442 if (error)
1443 return error;
1444
1445 error = bus_register(&wmi_bus_type);
1446 if (error)
1447 goto err_unreg_class;
1448
1449 error = platform_driver_register(&acpi_wmi_driver);
1450 if (error) {
1451 pr_err("Error loading mapper\n");
1452 goto err_unreg_bus;
1453 }
1454
1455 return 0;
1456
1457err_unreg_bus:
1458 bus_unregister(&wmi_bus_type);
1459
1460err_unreg_class:
1461 class_unregister(&wmi_bus_class);
1462
1463 return error;
1464}
1465
1466static void __exit acpi_wmi_exit(void)
1467{
1468 platform_driver_unregister(&acpi_wmi_driver);
1469 bus_unregister(&wmi_bus_type);
1470 class_unregister(&wmi_bus_class);
1471}
1472
1473subsys_initcall_sync(acpi_wmi_init);
1474module_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);