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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// 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);