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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * ACPI-WMI mapping driver
4 *
5 * Copyright (C) 2007-2008 Carlos Corbacho <carlos@strangeworlds.co.uk>
6 *
7 * GUID parsing code from ldm.c is:
8 * Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
9 * Copyright (c) 2001-2007 Anton Altaparmakov
10 * Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
11 *
12 * WMI bus infrastructure by Andrew Lutomirski and Darren Hart:
13 * Copyright (C) 2015 Andrew Lutomirski
14 * Copyright (C) 2017 VMware, Inc. All Rights Reserved.
15 */
16
17#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18
19#include <linux/acpi.h>
20#include <linux/device.h>
21#include <linux/init.h>
22#include <linux/kernel.h>
23#include <linux/list.h>
24#include <linux/miscdevice.h>
25#include <linux/module.h>
26#include <linux/platform_device.h>
27#include <linux/slab.h>
28#include <linux/types.h>
29#include <linux/uaccess.h>
30#include <linux/uuid.h>
31#include <linux/wmi.h>
32#include <linux/fs.h>
33#include <uapi/linux/wmi.h>
34
35MODULE_AUTHOR("Carlos Corbacho");
36MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
37MODULE_LICENSE("GPL");
38
39static LIST_HEAD(wmi_block_list);
40
41struct guid_block {
42 char guid[16];
43 union {
44 char object_id[2];
45 struct {
46 unsigned char notify_id;
47 unsigned char reserved;
48 };
49 };
50 u8 instance_count;
51 u8 flags;
52};
53
54struct wmi_block {
55 struct wmi_device dev;
56 struct list_head list;
57 struct guid_block gblock;
58 struct miscdevice char_dev;
59 struct mutex char_mutex;
60 struct acpi_device *acpi_device;
61 wmi_notify_handler handler;
62 void *handler_data;
63 u64 req_buf_size;
64
65 bool read_takes_no_args;
66};
67
68
69/*
70 * If the GUID data block is marked as expensive, we must enable and
71 * explicitily disable data collection.
72 */
73#define ACPI_WMI_EXPENSIVE 0x1
74#define ACPI_WMI_METHOD 0x2 /* GUID is a method */
75#define ACPI_WMI_STRING 0x4 /* GUID takes & returns a string */
76#define ACPI_WMI_EVENT 0x8 /* GUID is an event */
77
78static bool debug_event;
79module_param(debug_event, bool, 0444);
80MODULE_PARM_DESC(debug_event,
81 "Log WMI Events [0/1]");
82
83static bool debug_dump_wdg;
84module_param(debug_dump_wdg, bool, 0444);
85MODULE_PARM_DESC(debug_dump_wdg,
86 "Dump available WMI interfaces [0/1]");
87
88static int acpi_wmi_remove(struct platform_device *device);
89static int acpi_wmi_probe(struct platform_device *device);
90
91static const struct acpi_device_id wmi_device_ids[] = {
92 {"PNP0C14", 0},
93 {"pnp0c14", 0},
94 {"", 0},
95};
96MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
97
98static struct platform_driver acpi_wmi_driver = {
99 .driver = {
100 .name = "acpi-wmi",
101 .acpi_match_table = wmi_device_ids,
102 },
103 .probe = acpi_wmi_probe,
104 .remove = acpi_wmi_remove,
105};
106
107/*
108 * GUID parsing functions
109 */
110
111static bool find_guid(const char *guid_string, struct wmi_block **out)
112{
113 guid_t guid_input;
114 struct wmi_block *wblock;
115 struct guid_block *block;
116
117 if (guid_parse(guid_string, &guid_input))
118 return false;
119
120 list_for_each_entry(wblock, &wmi_block_list, list) {
121 block = &wblock->gblock;
122
123 if (memcmp(block->guid, &guid_input, 16) == 0) {
124 if (out)
125 *out = wblock;
126 return true;
127 }
128 }
129 return false;
130}
131
132static const void *find_guid_context(struct wmi_block *wblock,
133 struct wmi_driver *wdriver)
134{
135 const struct wmi_device_id *id;
136 guid_t guid_input;
137
138 if (wblock == NULL || wdriver == NULL)
139 return NULL;
140 if (wdriver->id_table == NULL)
141 return NULL;
142
143 id = wdriver->id_table;
144 while (*id->guid_string) {
145 if (guid_parse(id->guid_string, &guid_input))
146 continue;
147 if (!memcmp(wblock->gblock.guid, &guid_input, 16))
148 return id->context;
149 id++;
150 }
151 return NULL;
152}
153
154static int get_subobj_info(acpi_handle handle, const char *pathname,
155 struct acpi_device_info **info)
156{
157 struct acpi_device_info *dummy_info, **info_ptr;
158 acpi_handle subobj_handle;
159 acpi_status status;
160
161 status = acpi_get_handle(handle, (char *)pathname, &subobj_handle);
162 if (status == AE_NOT_FOUND)
163 return -ENOENT;
164 else if (ACPI_FAILURE(status))
165 return -EIO;
166
167 info_ptr = info ? info : &dummy_info;
168 status = acpi_get_object_info(subobj_handle, info_ptr);
169 if (ACPI_FAILURE(status))
170 return -EIO;
171
172 if (!info)
173 kfree(dummy_info);
174
175 return 0;
176}
177
178static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable)
179{
180 struct guid_block *block = NULL;
181 char method[5];
182 acpi_status status;
183 acpi_handle handle;
184
185 block = &wblock->gblock;
186 handle = wblock->acpi_device->handle;
187
188 snprintf(method, 5, "WE%02X", block->notify_id);
189 status = acpi_execute_simple_method(handle, method, enable);
190
191 if (status != AE_OK && status != AE_NOT_FOUND)
192 return status;
193 else
194 return AE_OK;
195}
196
197/*
198 * Exported WMI functions
199 */
200
201/**
202 * set_required_buffer_size - Sets the buffer size needed for performing IOCTL
203 * @wdev: A wmi bus device from a driver
204 * @length: Required buffer size
205 *
206 * Allocates memory needed for buffer, stores the buffer size in that memory
207 */
208int set_required_buffer_size(struct wmi_device *wdev, u64 length)
209{
210 struct wmi_block *wblock;
211
212 wblock = container_of(wdev, struct wmi_block, dev);
213 wblock->req_buf_size = length;
214
215 return 0;
216}
217EXPORT_SYMBOL_GPL(set_required_buffer_size);
218
219/**
220 * wmi_evaluate_method - Evaluate a WMI method
221 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
222 * @instance: Instance index
223 * @method_id: Method ID to call
224 * @in: Buffer containing input for the method call
225 * @out: Empty buffer to return the method results
226 *
227 * Call an ACPI-WMI method
228 */
229acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
230u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
231{
232 struct wmi_block *wblock = NULL;
233
234 if (!find_guid(guid_string, &wblock))
235 return AE_ERROR;
236 return wmidev_evaluate_method(&wblock->dev, instance, method_id,
237 in, out);
238}
239EXPORT_SYMBOL_GPL(wmi_evaluate_method);
240
241/**
242 * wmidev_evaluate_method - Evaluate a WMI method
243 * @wdev: A wmi bus device from a driver
244 * @instance: Instance index
245 * @method_id: Method ID to call
246 * @in: Buffer containing input for the method call
247 * @out: Empty buffer to return the method results
248 *
249 * Call an ACPI-WMI method
250 */
251acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance,
252 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
253{
254 struct guid_block *block = NULL;
255 struct wmi_block *wblock = NULL;
256 acpi_handle handle;
257 acpi_status status;
258 struct acpi_object_list input;
259 union acpi_object params[3];
260 char method[5] = "WM";
261
262 wblock = container_of(wdev, struct wmi_block, dev);
263 block = &wblock->gblock;
264 handle = wblock->acpi_device->handle;
265
266 if (!(block->flags & ACPI_WMI_METHOD))
267 return AE_BAD_DATA;
268
269 if (block->instance_count <= instance)
270 return AE_BAD_PARAMETER;
271
272 input.count = 2;
273 input.pointer = params;
274 params[0].type = ACPI_TYPE_INTEGER;
275 params[0].integer.value = instance;
276 params[1].type = ACPI_TYPE_INTEGER;
277 params[1].integer.value = method_id;
278
279 if (in) {
280 input.count = 3;
281
282 if (block->flags & ACPI_WMI_STRING) {
283 params[2].type = ACPI_TYPE_STRING;
284 } else {
285 params[2].type = ACPI_TYPE_BUFFER;
286 }
287 params[2].buffer.length = in->length;
288 params[2].buffer.pointer = in->pointer;
289 }
290
291 strncat(method, block->object_id, 2);
292
293 status = acpi_evaluate_object(handle, method, &input, out);
294
295 return status;
296}
297EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
298
299static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
300 struct acpi_buffer *out)
301{
302 struct guid_block *block = NULL;
303 acpi_handle handle;
304 acpi_status status, wc_status = AE_ERROR;
305 struct acpi_object_list input;
306 union acpi_object wq_params[1];
307 char method[5];
308 char wc_method[5] = "WC";
309
310 if (!out)
311 return AE_BAD_PARAMETER;
312
313 block = &wblock->gblock;
314 handle = wblock->acpi_device->handle;
315
316 if (block->instance_count <= instance)
317 return AE_BAD_PARAMETER;
318
319 /* Check GUID is a data block */
320 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
321 return AE_ERROR;
322
323 input.count = 1;
324 input.pointer = wq_params;
325 wq_params[0].type = ACPI_TYPE_INTEGER;
326 wq_params[0].integer.value = instance;
327
328 if (instance == 0 && wblock->read_takes_no_args)
329 input.count = 0;
330
331 /*
332 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
333 * enable collection.
334 */
335 if (block->flags & ACPI_WMI_EXPENSIVE) {
336 strncat(wc_method, block->object_id, 2);
337
338 /*
339 * Some GUIDs break the specification by declaring themselves
340 * expensive, but have no corresponding WCxx method. So we
341 * should not fail if this happens.
342 */
343 wc_status = acpi_execute_simple_method(handle, wc_method, 1);
344 }
345
346 strcpy(method, "WQ");
347 strncat(method, block->object_id, 2);
348
349 status = acpi_evaluate_object(handle, method, &input, out);
350
351 /*
352 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
353 * the WQxx method failed - we should disable collection anyway.
354 */
355 if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
356 status = acpi_execute_simple_method(handle, wc_method, 0);
357 }
358
359 return status;
360}
361
362/**
363 * wmi_query_block - Return contents of a WMI block (deprecated)
364 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
365 * @instance: Instance index
366 * @out: Empty buffer to return the contents of the data block to
367 *
368 * Return the contents of an ACPI-WMI data block to a buffer
369 */
370acpi_status wmi_query_block(const char *guid_string, u8 instance,
371 struct acpi_buffer *out)
372{
373 struct wmi_block *wblock;
374
375 if (!guid_string)
376 return AE_BAD_PARAMETER;
377
378 if (!find_guid(guid_string, &wblock))
379 return AE_ERROR;
380
381 return __query_block(wblock, instance, out);
382}
383EXPORT_SYMBOL_GPL(wmi_query_block);
384
385union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
386{
387 struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
388 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
389
390 if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
391 return NULL;
392
393 return (union acpi_object *)out.pointer;
394}
395EXPORT_SYMBOL_GPL(wmidev_block_query);
396
397/**
398 * wmi_set_block - Write to a WMI block
399 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
400 * @instance: Instance index
401 * @in: Buffer containing new values for the data block
402 *
403 * Write the contents of the input buffer to an ACPI-WMI data block
404 */
405acpi_status wmi_set_block(const char *guid_string, u8 instance,
406 const struct acpi_buffer *in)
407{
408 struct guid_block *block = NULL;
409 struct wmi_block *wblock = NULL;
410 acpi_handle handle;
411 struct acpi_object_list input;
412 union acpi_object params[2];
413 char method[5] = "WS";
414
415 if (!guid_string || !in)
416 return AE_BAD_DATA;
417
418 if (!find_guid(guid_string, &wblock))
419 return AE_ERROR;
420
421 block = &wblock->gblock;
422 handle = wblock->acpi_device->handle;
423
424 if (block->instance_count <= instance)
425 return AE_BAD_PARAMETER;
426
427 /* Check GUID is a data block */
428 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
429 return AE_ERROR;
430
431 input.count = 2;
432 input.pointer = params;
433 params[0].type = ACPI_TYPE_INTEGER;
434 params[0].integer.value = instance;
435
436 if (block->flags & ACPI_WMI_STRING) {
437 params[1].type = ACPI_TYPE_STRING;
438 } else {
439 params[1].type = ACPI_TYPE_BUFFER;
440 }
441 params[1].buffer.length = in->length;
442 params[1].buffer.pointer = in->pointer;
443
444 strncat(method, block->object_id, 2);
445
446 return acpi_evaluate_object(handle, method, &input, NULL);
447}
448EXPORT_SYMBOL_GPL(wmi_set_block);
449
450static void wmi_dump_wdg(const struct guid_block *g)
451{
452 pr_info("%pUL:\n", g->guid);
453 if (g->flags & ACPI_WMI_EVENT)
454 pr_info("\tnotify_id: 0x%02X\n", g->notify_id);
455 else
456 pr_info("\tobject_id: %2pE\n", g->object_id);
457 pr_info("\tinstance_count: %d\n", g->instance_count);
458 pr_info("\tflags: %#x", g->flags);
459 if (g->flags) {
460 if (g->flags & ACPI_WMI_EXPENSIVE)
461 pr_cont(" ACPI_WMI_EXPENSIVE");
462 if (g->flags & ACPI_WMI_METHOD)
463 pr_cont(" ACPI_WMI_METHOD");
464 if (g->flags & ACPI_WMI_STRING)
465 pr_cont(" ACPI_WMI_STRING");
466 if (g->flags & ACPI_WMI_EVENT)
467 pr_cont(" ACPI_WMI_EVENT");
468 }
469 pr_cont("\n");
470
471}
472
473static void wmi_notify_debug(u32 value, void *context)
474{
475 struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
476 union acpi_object *obj;
477 acpi_status status;
478
479 status = wmi_get_event_data(value, &response);
480 if (status != AE_OK) {
481 pr_info("bad event status 0x%x\n", status);
482 return;
483 }
484
485 obj = (union acpi_object *)response.pointer;
486
487 if (!obj)
488 return;
489
490 pr_info("DEBUG Event ");
491 switch(obj->type) {
492 case ACPI_TYPE_BUFFER:
493 pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
494 break;
495 case ACPI_TYPE_STRING:
496 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
497 break;
498 case ACPI_TYPE_INTEGER:
499 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
500 break;
501 case ACPI_TYPE_PACKAGE:
502 pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
503 break;
504 default:
505 pr_cont("object type 0x%X\n", obj->type);
506 }
507 kfree(obj);
508}
509
510/**
511 * wmi_install_notify_handler - Register handler for WMI events
512 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
513 * @handler: Function to handle notifications
514 * @data: Data to be returned to handler when event is fired
515 *
516 * Register a handler for events sent to the ACPI-WMI mapper device.
517 */
518acpi_status wmi_install_notify_handler(const char *guid,
519wmi_notify_handler handler, void *data)
520{
521 struct wmi_block *block;
522 acpi_status status = AE_NOT_EXIST;
523 guid_t guid_input;
524
525 if (!guid || !handler)
526 return AE_BAD_PARAMETER;
527
528 if (guid_parse(guid, &guid_input))
529 return AE_BAD_PARAMETER;
530
531 list_for_each_entry(block, &wmi_block_list, list) {
532 acpi_status wmi_status;
533
534 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
535 if (block->handler &&
536 block->handler != wmi_notify_debug)
537 return AE_ALREADY_ACQUIRED;
538
539 block->handler = handler;
540 block->handler_data = data;
541
542 wmi_status = wmi_method_enable(block, 1);
543 if ((wmi_status != AE_OK) ||
544 ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
545 status = wmi_status;
546 }
547 }
548
549 return status;
550}
551EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
552
553/**
554 * wmi_uninstall_notify_handler - Unregister handler for WMI events
555 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
556 *
557 * Unregister handler for events sent to the ACPI-WMI mapper device.
558 */
559acpi_status wmi_remove_notify_handler(const char *guid)
560{
561 struct wmi_block *block;
562 acpi_status status = AE_NOT_EXIST;
563 guid_t guid_input;
564
565 if (!guid)
566 return AE_BAD_PARAMETER;
567
568 if (guid_parse(guid, &guid_input))
569 return AE_BAD_PARAMETER;
570
571 list_for_each_entry(block, &wmi_block_list, list) {
572 acpi_status wmi_status;
573
574 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
575 if (!block->handler ||
576 block->handler == wmi_notify_debug)
577 return AE_NULL_ENTRY;
578
579 if (debug_event) {
580 block->handler = wmi_notify_debug;
581 status = AE_OK;
582 } else {
583 wmi_status = wmi_method_enable(block, 0);
584 block->handler = NULL;
585 block->handler_data = NULL;
586 if ((wmi_status != AE_OK) ||
587 ((wmi_status == AE_OK) &&
588 (status == AE_NOT_EXIST)))
589 status = wmi_status;
590 }
591 }
592 }
593
594 return status;
595}
596EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
597
598/**
599 * wmi_get_event_data - Get WMI data associated with an event
600 *
601 * @event: Event to find
602 * @out: Buffer to hold event data. out->pointer should be freed with kfree()
603 *
604 * Returns extra data associated with an event in WMI.
605 */
606acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
607{
608 struct acpi_object_list input;
609 union acpi_object params[1];
610 struct guid_block *gblock;
611 struct wmi_block *wblock;
612
613 input.count = 1;
614 input.pointer = params;
615 params[0].type = ACPI_TYPE_INTEGER;
616 params[0].integer.value = event;
617
618 list_for_each_entry(wblock, &wmi_block_list, list) {
619 gblock = &wblock->gblock;
620
621 if ((gblock->flags & ACPI_WMI_EVENT) &&
622 (gblock->notify_id == event))
623 return acpi_evaluate_object(wblock->acpi_device->handle,
624 "_WED", &input, out);
625 }
626
627 return AE_NOT_FOUND;
628}
629EXPORT_SYMBOL_GPL(wmi_get_event_data);
630
631/**
632 * wmi_has_guid - Check if a GUID is available
633 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
634 *
635 * Check if a given GUID is defined by _WDG
636 */
637bool wmi_has_guid(const char *guid_string)
638{
639 return find_guid(guid_string, NULL);
640}
641EXPORT_SYMBOL_GPL(wmi_has_guid);
642
643/**
644 * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID
645 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
646 *
647 * Find the _UID of ACPI device associated with this WMI GUID.
648 *
649 * Return: The ACPI _UID field value or NULL if the WMI GUID was not found
650 */
651char *wmi_get_acpi_device_uid(const char *guid_string)
652{
653 struct wmi_block *wblock = NULL;
654
655 if (!find_guid(guid_string, &wblock))
656 return NULL;
657
658 return acpi_device_uid(wblock->acpi_device);
659}
660EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
661
662static struct wmi_block *dev_to_wblock(struct device *dev)
663{
664 return container_of(dev, struct wmi_block, dev.dev);
665}
666
667static struct wmi_device *dev_to_wdev(struct device *dev)
668{
669 return container_of(dev, struct wmi_device, dev);
670}
671
672/*
673 * sysfs interface
674 */
675static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
676 char *buf)
677{
678 struct wmi_block *wblock = dev_to_wblock(dev);
679
680 return sprintf(buf, "wmi:%pUL\n", wblock->gblock.guid);
681}
682static DEVICE_ATTR_RO(modalias);
683
684static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
685 char *buf)
686{
687 struct wmi_block *wblock = dev_to_wblock(dev);
688
689 return sprintf(buf, "%pUL\n", wblock->gblock.guid);
690}
691static DEVICE_ATTR_RO(guid);
692
693static ssize_t instance_count_show(struct device *dev,
694 struct device_attribute *attr, char *buf)
695{
696 struct wmi_block *wblock = dev_to_wblock(dev);
697
698 return sprintf(buf, "%d\n", (int)wblock->gblock.instance_count);
699}
700static DEVICE_ATTR_RO(instance_count);
701
702static ssize_t expensive_show(struct device *dev,
703 struct device_attribute *attr, char *buf)
704{
705 struct wmi_block *wblock = dev_to_wblock(dev);
706
707 return sprintf(buf, "%d\n",
708 (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
709}
710static DEVICE_ATTR_RO(expensive);
711
712static struct attribute *wmi_attrs[] = {
713 &dev_attr_modalias.attr,
714 &dev_attr_guid.attr,
715 &dev_attr_instance_count.attr,
716 &dev_attr_expensive.attr,
717 NULL,
718};
719ATTRIBUTE_GROUPS(wmi);
720
721static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
722 char *buf)
723{
724 struct wmi_block *wblock = dev_to_wblock(dev);
725
726 return sprintf(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
727}
728static DEVICE_ATTR_RO(notify_id);
729
730static struct attribute *wmi_event_attrs[] = {
731 &dev_attr_notify_id.attr,
732 NULL,
733};
734ATTRIBUTE_GROUPS(wmi_event);
735
736static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
737 char *buf)
738{
739 struct wmi_block *wblock = dev_to_wblock(dev);
740
741 return sprintf(buf, "%c%c\n", wblock->gblock.object_id[0],
742 wblock->gblock.object_id[1]);
743}
744static DEVICE_ATTR_RO(object_id);
745
746static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
747 char *buf)
748{
749 struct wmi_device *wdev = dev_to_wdev(dev);
750
751 return sprintf(buf, "%d\n", (int)wdev->setable);
752}
753static DEVICE_ATTR_RO(setable);
754
755static struct attribute *wmi_data_attrs[] = {
756 &dev_attr_object_id.attr,
757 &dev_attr_setable.attr,
758 NULL,
759};
760ATTRIBUTE_GROUPS(wmi_data);
761
762static struct attribute *wmi_method_attrs[] = {
763 &dev_attr_object_id.attr,
764 NULL,
765};
766ATTRIBUTE_GROUPS(wmi_method);
767
768static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
769{
770 struct wmi_block *wblock = dev_to_wblock(dev);
771
772 if (add_uevent_var(env, "MODALIAS=wmi:%pUL", wblock->gblock.guid))
773 return -ENOMEM;
774
775 if (add_uevent_var(env, "WMI_GUID=%pUL", wblock->gblock.guid))
776 return -ENOMEM;
777
778 return 0;
779}
780
781static void wmi_dev_release(struct device *dev)
782{
783 struct wmi_block *wblock = dev_to_wblock(dev);
784
785 kfree(wblock);
786}
787
788static int wmi_dev_match(struct device *dev, struct device_driver *driver)
789{
790 struct wmi_driver *wmi_driver =
791 container_of(driver, struct wmi_driver, driver);
792 struct wmi_block *wblock = dev_to_wblock(dev);
793 const struct wmi_device_id *id = wmi_driver->id_table;
794
795 if (id == NULL)
796 return 0;
797
798 while (*id->guid_string) {
799 guid_t driver_guid;
800
801 if (WARN_ON(guid_parse(id->guid_string, &driver_guid)))
802 continue;
803 if (!memcmp(&driver_guid, wblock->gblock.guid, 16))
804 return 1;
805
806 id++;
807 }
808
809 return 0;
810}
811static int wmi_char_open(struct inode *inode, struct file *filp)
812{
813 const char *driver_name = filp->f_path.dentry->d_iname;
814 struct wmi_block *wblock = NULL;
815 struct wmi_block *next = NULL;
816
817 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
818 if (!wblock->dev.dev.driver)
819 continue;
820 if (strcmp(driver_name, wblock->dev.dev.driver->name) == 0) {
821 filp->private_data = wblock;
822 break;
823 }
824 }
825
826 if (!filp->private_data)
827 return -ENODEV;
828
829 return nonseekable_open(inode, filp);
830}
831
832static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
833 size_t length, loff_t *offset)
834{
835 struct wmi_block *wblock = filp->private_data;
836
837 return simple_read_from_buffer(buffer, length, offset,
838 &wblock->req_buf_size,
839 sizeof(wblock->req_buf_size));
840}
841
842static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
843{
844 struct wmi_ioctl_buffer __user *input =
845 (struct wmi_ioctl_buffer __user *) arg;
846 struct wmi_block *wblock = filp->private_data;
847 struct wmi_ioctl_buffer *buf = NULL;
848 struct wmi_driver *wdriver = NULL;
849 int ret;
850
851 if (_IOC_TYPE(cmd) != WMI_IOC)
852 return -ENOTTY;
853
854 /* make sure we're not calling a higher instance than exists*/
855 if (_IOC_NR(cmd) >= wblock->gblock.instance_count)
856 return -EINVAL;
857
858 mutex_lock(&wblock->char_mutex);
859 buf = wblock->handler_data;
860 if (get_user(buf->length, &input->length)) {
861 dev_dbg(&wblock->dev.dev, "Read length from user failed\n");
862 ret = -EFAULT;
863 goto out_ioctl;
864 }
865 /* if it's too small, abort */
866 if (buf->length < wblock->req_buf_size) {
867 dev_err(&wblock->dev.dev,
868 "Buffer %lld too small, need at least %lld\n",
869 buf->length, wblock->req_buf_size);
870 ret = -EINVAL;
871 goto out_ioctl;
872 }
873 /* if it's too big, warn, driver will only use what is needed */
874 if (buf->length > wblock->req_buf_size)
875 dev_warn(&wblock->dev.dev,
876 "Buffer %lld is bigger than required %lld\n",
877 buf->length, wblock->req_buf_size);
878
879 /* copy the structure from userspace */
880 if (copy_from_user(buf, input, wblock->req_buf_size)) {
881 dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n",
882 wblock->req_buf_size);
883 ret = -EFAULT;
884 goto out_ioctl;
885 }
886
887 /* let the driver do any filtering and do the call */
888 wdriver = container_of(wblock->dev.dev.driver,
889 struct wmi_driver, driver);
890 if (!try_module_get(wdriver->driver.owner)) {
891 ret = -EBUSY;
892 goto out_ioctl;
893 }
894 ret = wdriver->filter_callback(&wblock->dev, cmd, buf);
895 module_put(wdriver->driver.owner);
896 if (ret)
897 goto out_ioctl;
898
899 /* return the result (only up to our internal buffer size) */
900 if (copy_to_user(input, buf, wblock->req_buf_size)) {
901 dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n",
902 wblock->req_buf_size);
903 ret = -EFAULT;
904 }
905
906out_ioctl:
907 mutex_unlock(&wblock->char_mutex);
908 return ret;
909}
910
911static const struct file_operations wmi_fops = {
912 .owner = THIS_MODULE,
913 .read = wmi_char_read,
914 .open = wmi_char_open,
915 .unlocked_ioctl = wmi_ioctl,
916 .compat_ioctl = compat_ptr_ioctl,
917};
918
919static int wmi_dev_probe(struct device *dev)
920{
921 struct wmi_block *wblock = dev_to_wblock(dev);
922 struct wmi_driver *wdriver =
923 container_of(dev->driver, struct wmi_driver, driver);
924 int ret = 0;
925 char *buf;
926
927 if (ACPI_FAILURE(wmi_method_enable(wblock, 1)))
928 dev_warn(dev, "failed to enable device -- probing anyway\n");
929
930 if (wdriver->probe) {
931 ret = wdriver->probe(dev_to_wdev(dev),
932 find_guid_context(wblock, wdriver));
933 if (ret != 0)
934 goto probe_failure;
935 }
936
937 /* driver wants a character device made */
938 if (wdriver->filter_callback) {
939 /* check that required buffer size declared by driver or MOF */
940 if (!wblock->req_buf_size) {
941 dev_err(&wblock->dev.dev,
942 "Required buffer size not set\n");
943 ret = -EINVAL;
944 goto probe_failure;
945 }
946
947 wblock->handler_data = kmalloc(wblock->req_buf_size,
948 GFP_KERNEL);
949 if (!wblock->handler_data) {
950 ret = -ENOMEM;
951 goto probe_failure;
952 }
953
954 buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name);
955 if (!buf) {
956 ret = -ENOMEM;
957 goto probe_string_failure;
958 }
959 wblock->char_dev.minor = MISC_DYNAMIC_MINOR;
960 wblock->char_dev.name = buf;
961 wblock->char_dev.fops = &wmi_fops;
962 wblock->char_dev.mode = 0444;
963 ret = misc_register(&wblock->char_dev);
964 if (ret) {
965 dev_warn(dev, "failed to register char dev: %d\n", ret);
966 ret = -ENOMEM;
967 goto probe_misc_failure;
968 }
969 }
970
971 return 0;
972
973probe_misc_failure:
974 kfree(buf);
975probe_string_failure:
976 kfree(wblock->handler_data);
977probe_failure:
978 if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
979 dev_warn(dev, "failed to disable device\n");
980 return ret;
981}
982
983static int wmi_dev_remove(struct device *dev)
984{
985 struct wmi_block *wblock = dev_to_wblock(dev);
986 struct wmi_driver *wdriver =
987 container_of(dev->driver, struct wmi_driver, driver);
988
989 if (wdriver->filter_callback) {
990 misc_deregister(&wblock->char_dev);
991 kfree(wblock->char_dev.name);
992 kfree(wblock->handler_data);
993 }
994
995 if (wdriver->remove)
996 wdriver->remove(dev_to_wdev(dev));
997
998 if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
999 dev_warn(dev, "failed to disable device\n");
1000
1001 return 0;
1002}
1003
1004static struct class wmi_bus_class = {
1005 .name = "wmi_bus",
1006};
1007
1008static struct bus_type wmi_bus_type = {
1009 .name = "wmi",
1010 .dev_groups = wmi_groups,
1011 .match = wmi_dev_match,
1012 .uevent = wmi_dev_uevent,
1013 .probe = wmi_dev_probe,
1014 .remove = wmi_dev_remove,
1015};
1016
1017static const struct device_type wmi_type_event = {
1018 .name = "event",
1019 .groups = wmi_event_groups,
1020 .release = wmi_dev_release,
1021};
1022
1023static const struct device_type wmi_type_method = {
1024 .name = "method",
1025 .groups = wmi_method_groups,
1026 .release = wmi_dev_release,
1027};
1028
1029static const struct device_type wmi_type_data = {
1030 .name = "data",
1031 .groups = wmi_data_groups,
1032 .release = wmi_dev_release,
1033};
1034
1035static int wmi_create_device(struct device *wmi_bus_dev,
1036 const struct guid_block *gblock,
1037 struct wmi_block *wblock,
1038 struct acpi_device *device)
1039{
1040 struct acpi_device_info *info;
1041 char method[5];
1042 int result;
1043
1044 if (gblock->flags & ACPI_WMI_EVENT) {
1045 wblock->dev.dev.type = &wmi_type_event;
1046 goto out_init;
1047 }
1048
1049 if (gblock->flags & ACPI_WMI_METHOD) {
1050 wblock->dev.dev.type = &wmi_type_method;
1051 mutex_init(&wblock->char_mutex);
1052 goto out_init;
1053 }
1054
1055 /*
1056 * Data Block Query Control Method (WQxx by convention) is
1057 * required per the WMI documentation. If it is not present,
1058 * we ignore this data block.
1059 */
1060 strcpy(method, "WQ");
1061 strncat(method, wblock->gblock.object_id, 2);
1062 result = get_subobj_info(device->handle, method, &info);
1063
1064 if (result) {
1065 dev_warn(wmi_bus_dev,
1066 "%s data block query control method not found\n",
1067 method);
1068 return result;
1069 }
1070
1071 wblock->dev.dev.type = &wmi_type_data;
1072
1073 /*
1074 * The Microsoft documentation specifically states:
1075 *
1076 * Data blocks registered with only a single instance
1077 * can ignore the parameter.
1078 *
1079 * ACPICA will get mad at us if we call the method with the wrong number
1080 * of arguments, so check what our method expects. (On some Dell
1081 * laptops, WQxx may not be a method at all.)
1082 */
1083 if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1084 wblock->read_takes_no_args = true;
1085
1086 kfree(info);
1087
1088 strcpy(method, "WS");
1089 strncat(method, wblock->gblock.object_id, 2);
1090 result = get_subobj_info(device->handle, method, NULL);
1091
1092 if (result == 0)
1093 wblock->dev.setable = true;
1094
1095 out_init:
1096 wblock->dev.dev.bus = &wmi_bus_type;
1097 wblock->dev.dev.parent = wmi_bus_dev;
1098
1099 dev_set_name(&wblock->dev.dev, "%pUL", gblock->guid);
1100
1101 device_initialize(&wblock->dev.dev);
1102
1103 return 0;
1104}
1105
1106static void wmi_free_devices(struct acpi_device *device)
1107{
1108 struct wmi_block *wblock, *next;
1109
1110 /* Delete devices for all the GUIDs */
1111 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1112 if (wblock->acpi_device == device) {
1113 list_del(&wblock->list);
1114 device_unregister(&wblock->dev.dev);
1115 }
1116 }
1117}
1118
1119static bool guid_already_parsed(struct acpi_device *device, const u8 *guid)
1120{
1121 struct wmi_block *wblock;
1122
1123 list_for_each_entry(wblock, &wmi_block_list, list) {
1124 if (memcmp(wblock->gblock.guid, guid, 16) == 0) {
1125 /*
1126 * Because we historically didn't track the relationship
1127 * between GUIDs and ACPI nodes, we don't know whether
1128 * we need to suppress GUIDs that are unique on a
1129 * given node but duplicated across nodes.
1130 */
1131 dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
1132 guid, dev_name(&wblock->acpi_device->dev));
1133 return true;
1134 }
1135 }
1136
1137 return false;
1138}
1139
1140/*
1141 * Parse the _WDG method for the GUID data blocks
1142 */
1143static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
1144{
1145 struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1146 const struct guid_block *gblock;
1147 struct wmi_block *wblock, *next;
1148 union acpi_object *obj;
1149 acpi_status status;
1150 int retval = 0;
1151 u32 i, total;
1152
1153 status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1154 if (ACPI_FAILURE(status))
1155 return -ENXIO;
1156
1157 obj = (union acpi_object *) out.pointer;
1158 if (!obj)
1159 return -ENXIO;
1160
1161 if (obj->type != ACPI_TYPE_BUFFER) {
1162 retval = -ENXIO;
1163 goto out_free_pointer;
1164 }
1165
1166 gblock = (const struct guid_block *)obj->buffer.pointer;
1167 total = obj->buffer.length / sizeof(struct guid_block);
1168
1169 for (i = 0; i < total; i++) {
1170 if (debug_dump_wdg)
1171 wmi_dump_wdg(&gblock[i]);
1172
1173 /*
1174 * Some WMI devices, like those for nVidia hooks, have a
1175 * duplicate GUID. It's not clear what we should do in this
1176 * case yet, so for now, we'll just ignore the duplicate
1177 * for device creation.
1178 */
1179 if (guid_already_parsed(device, gblock[i].guid))
1180 continue;
1181
1182 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
1183 if (!wblock) {
1184 retval = -ENOMEM;
1185 break;
1186 }
1187
1188 wblock->acpi_device = device;
1189 wblock->gblock = gblock[i];
1190
1191 retval = wmi_create_device(wmi_bus_dev, &gblock[i], wblock, device);
1192 if (retval) {
1193 kfree(wblock);
1194 continue;
1195 }
1196
1197 list_add_tail(&wblock->list, &wmi_block_list);
1198
1199 if (debug_event) {
1200 wblock->handler = wmi_notify_debug;
1201 wmi_method_enable(wblock, 1);
1202 }
1203 }
1204
1205 /*
1206 * Now that all of the devices are created, add them to the
1207 * device tree and probe subdrivers.
1208 */
1209 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1210 if (wblock->acpi_device != device)
1211 continue;
1212
1213 retval = device_add(&wblock->dev.dev);
1214 if (retval) {
1215 dev_err(wmi_bus_dev, "failed to register %pUL\n",
1216 wblock->gblock.guid);
1217 if (debug_event)
1218 wmi_method_enable(wblock, 0);
1219 list_del(&wblock->list);
1220 put_device(&wblock->dev.dev);
1221 }
1222 }
1223
1224out_free_pointer:
1225 kfree(out.pointer);
1226 return retval;
1227}
1228
1229/*
1230 * WMI can have EmbeddedControl access regions. In which case, we just want to
1231 * hand these off to the EC driver.
1232 */
1233static acpi_status
1234acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1235 u32 bits, u64 *value,
1236 void *handler_context, void *region_context)
1237{
1238 int result = 0, i = 0;
1239 u8 temp = 0;
1240
1241 if ((address > 0xFF) || !value)
1242 return AE_BAD_PARAMETER;
1243
1244 if (function != ACPI_READ && function != ACPI_WRITE)
1245 return AE_BAD_PARAMETER;
1246
1247 if (bits != 8)
1248 return AE_BAD_PARAMETER;
1249
1250 if (function == ACPI_READ) {
1251 result = ec_read(address, &temp);
1252 (*value) |= ((u64)temp) << i;
1253 } else {
1254 temp = 0xff & ((*value) >> i);
1255 result = ec_write(address, temp);
1256 }
1257
1258 switch (result) {
1259 case -EINVAL:
1260 return AE_BAD_PARAMETER;
1261 case -ENODEV:
1262 return AE_NOT_FOUND;
1263 case -ETIME:
1264 return AE_TIME;
1265 default:
1266 return AE_OK;
1267 }
1268}
1269
1270static void acpi_wmi_notify_handler(acpi_handle handle, u32 event,
1271 void *context)
1272{
1273 struct guid_block *block;
1274 struct wmi_block *wblock;
1275 bool found_it = false;
1276
1277 list_for_each_entry(wblock, &wmi_block_list, list) {
1278 block = &wblock->gblock;
1279
1280 if (wblock->acpi_device->handle == handle &&
1281 (block->flags & ACPI_WMI_EVENT) &&
1282 (block->notify_id == event))
1283 {
1284 found_it = true;
1285 break;
1286 }
1287 }
1288
1289 if (!found_it)
1290 return;
1291
1292 /* If a driver is bound, then notify the driver. */
1293 if (wblock->dev.dev.driver) {
1294 struct wmi_driver *driver;
1295 struct acpi_object_list input;
1296 union acpi_object params[1];
1297 struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL };
1298 acpi_status status;
1299
1300 driver = container_of(wblock->dev.dev.driver,
1301 struct wmi_driver, driver);
1302
1303 input.count = 1;
1304 input.pointer = params;
1305 params[0].type = ACPI_TYPE_INTEGER;
1306 params[0].integer.value = event;
1307
1308 status = acpi_evaluate_object(wblock->acpi_device->handle,
1309 "_WED", &input, &evdata);
1310 if (ACPI_FAILURE(status)) {
1311 dev_warn(&wblock->dev.dev,
1312 "failed to get event data\n");
1313 return;
1314 }
1315
1316 if (driver->notify)
1317 driver->notify(&wblock->dev,
1318 (union acpi_object *)evdata.pointer);
1319
1320 kfree(evdata.pointer);
1321 } else if (wblock->handler) {
1322 /* Legacy handler */
1323 wblock->handler(event, wblock->handler_data);
1324 }
1325
1326 if (debug_event)
1327 pr_info("DEBUG Event GUID: %pUL\n", wblock->gblock.guid);
1328
1329 acpi_bus_generate_netlink_event(
1330 wblock->acpi_device->pnp.device_class,
1331 dev_name(&wblock->dev.dev),
1332 event, 0);
1333
1334}
1335
1336static int acpi_wmi_remove(struct platform_device *device)
1337{
1338 struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev);
1339
1340 acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1341 acpi_wmi_notify_handler);
1342 acpi_remove_address_space_handler(acpi_device->handle,
1343 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
1344 wmi_free_devices(acpi_device);
1345 device_unregister((struct device *)dev_get_drvdata(&device->dev));
1346
1347 return 0;
1348}
1349
1350static int acpi_wmi_probe(struct platform_device *device)
1351{
1352 struct acpi_device *acpi_device;
1353 struct device *wmi_bus_dev;
1354 acpi_status status;
1355 int error;
1356
1357 acpi_device = ACPI_COMPANION(&device->dev);
1358 if (!acpi_device) {
1359 dev_err(&device->dev, "ACPI companion is missing\n");
1360 return -ENODEV;
1361 }
1362
1363 status = acpi_install_address_space_handler(acpi_device->handle,
1364 ACPI_ADR_SPACE_EC,
1365 &acpi_wmi_ec_space_handler,
1366 NULL, NULL);
1367 if (ACPI_FAILURE(status)) {
1368 dev_err(&device->dev, "Error installing EC region handler\n");
1369 return -ENODEV;
1370 }
1371
1372 status = acpi_install_notify_handler(acpi_device->handle,
1373 ACPI_DEVICE_NOTIFY,
1374 acpi_wmi_notify_handler,
1375 NULL);
1376 if (ACPI_FAILURE(status)) {
1377 dev_err(&device->dev, "Error installing notify handler\n");
1378 error = -ENODEV;
1379 goto err_remove_ec_handler;
1380 }
1381
1382 wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0),
1383 NULL, "wmi_bus-%s", dev_name(&device->dev));
1384 if (IS_ERR(wmi_bus_dev)) {
1385 error = PTR_ERR(wmi_bus_dev);
1386 goto err_remove_notify_handler;
1387 }
1388 dev_set_drvdata(&device->dev, wmi_bus_dev);
1389
1390 error = parse_wdg(wmi_bus_dev, acpi_device);
1391 if (error) {
1392 pr_err("Failed to parse WDG method\n");
1393 goto err_remove_busdev;
1394 }
1395
1396 return 0;
1397
1398err_remove_busdev:
1399 device_unregister(wmi_bus_dev);
1400
1401err_remove_notify_handler:
1402 acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1403 acpi_wmi_notify_handler);
1404
1405err_remove_ec_handler:
1406 acpi_remove_address_space_handler(acpi_device->handle,
1407 ACPI_ADR_SPACE_EC,
1408 &acpi_wmi_ec_space_handler);
1409
1410 return error;
1411}
1412
1413int __must_check __wmi_driver_register(struct wmi_driver *driver,
1414 struct module *owner)
1415{
1416 driver->driver.owner = owner;
1417 driver->driver.bus = &wmi_bus_type;
1418
1419 return driver_register(&driver->driver);
1420}
1421EXPORT_SYMBOL(__wmi_driver_register);
1422
1423void wmi_driver_unregister(struct wmi_driver *driver)
1424{
1425 driver_unregister(&driver->driver);
1426}
1427EXPORT_SYMBOL(wmi_driver_unregister);
1428
1429static int __init acpi_wmi_init(void)
1430{
1431 int error;
1432
1433 if (acpi_disabled)
1434 return -ENODEV;
1435
1436 error = class_register(&wmi_bus_class);
1437 if (error)
1438 return error;
1439
1440 error = bus_register(&wmi_bus_type);
1441 if (error)
1442 goto err_unreg_class;
1443
1444 error = platform_driver_register(&acpi_wmi_driver);
1445 if (error) {
1446 pr_err("Error loading mapper\n");
1447 goto err_unreg_bus;
1448 }
1449
1450 return 0;
1451
1452err_unreg_bus:
1453 bus_unregister(&wmi_bus_type);
1454
1455err_unreg_class:
1456 class_unregister(&wmi_bus_class);
1457
1458 return error;
1459}
1460
1461static void __exit acpi_wmi_exit(void)
1462{
1463 platform_driver_unregister(&acpi_wmi_driver);
1464 bus_unregister(&wmi_bus_type);
1465 class_unregister(&wmi_bus_class);
1466}
1467
1468subsys_initcall_sync(acpi_wmi_init);
1469module_exit(acpi_wmi_exit);
1/*
2 * ACPI-WMI mapping driver
3 *
4 * Copyright (C) 2007-2008 Carlos Corbacho <carlos@strangeworlds.co.uk>
5 *
6 * GUID parsing code from ldm.c is:
7 * Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
8 * Copyright (c) 2001-2007 Anton Altaparmakov
9 * Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
10 *
11 * WMI bus infrastructure by Andrew Lutomirski and Darren Hart:
12 * Copyright (C) 2015 Andrew Lutomirski
13 * Copyright (C) 2017 VMware, Inc. All Rights Reserved.
14 *
15 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
16 *
17 * This program is free software; you can redistribute it and/or modify
18 * it under the terms of the GNU General Public License as published by
19 * the Free Software Foundation; either version 2 of the License, or (at
20 * your option) any later version.
21 *
22 * This program is distributed in the hope that it will be useful, but
23 * WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
25 * General Public License for more details.
26 *
27 * You should have received a copy of the GNU General Public License along
28 * with this program; if not, write to the Free Software Foundation, Inc.,
29 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
30 *
31 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
32 */
33
34#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
35
36#include <linux/acpi.h>
37#include <linux/device.h>
38#include <linux/init.h>
39#include <linux/kernel.h>
40#include <linux/list.h>
41#include <linux/miscdevice.h>
42#include <linux/module.h>
43#include <linux/platform_device.h>
44#include <linux/slab.h>
45#include <linux/types.h>
46#include <linux/uaccess.h>
47#include <linux/uuid.h>
48#include <linux/wmi.h>
49#include <uapi/linux/wmi.h>
50
51ACPI_MODULE_NAME("wmi");
52MODULE_AUTHOR("Carlos Corbacho");
53MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
54MODULE_LICENSE("GPL");
55
56static LIST_HEAD(wmi_block_list);
57
58struct guid_block {
59 char guid[16];
60 union {
61 char object_id[2];
62 struct {
63 unsigned char notify_id;
64 unsigned char reserved;
65 };
66 };
67 u8 instance_count;
68 u8 flags;
69};
70
71struct wmi_block {
72 struct wmi_device dev;
73 struct list_head list;
74 struct guid_block gblock;
75 struct miscdevice char_dev;
76 struct mutex char_mutex;
77 struct acpi_device *acpi_device;
78 wmi_notify_handler handler;
79 void *handler_data;
80 u64 req_buf_size;
81
82 bool read_takes_no_args;
83};
84
85
86/*
87 * If the GUID data block is marked as expensive, we must enable and
88 * explicitily disable data collection.
89 */
90#define ACPI_WMI_EXPENSIVE 0x1
91#define ACPI_WMI_METHOD 0x2 /* GUID is a method */
92#define ACPI_WMI_STRING 0x4 /* GUID takes & returns a string */
93#define ACPI_WMI_EVENT 0x8 /* GUID is an event */
94
95static bool debug_event;
96module_param(debug_event, bool, 0444);
97MODULE_PARM_DESC(debug_event,
98 "Log WMI Events [0/1]");
99
100static bool debug_dump_wdg;
101module_param(debug_dump_wdg, bool, 0444);
102MODULE_PARM_DESC(debug_dump_wdg,
103 "Dump available WMI interfaces [0/1]");
104
105static int acpi_wmi_remove(struct platform_device *device);
106static int acpi_wmi_probe(struct platform_device *device);
107
108static const struct acpi_device_id wmi_device_ids[] = {
109 {"PNP0C14", 0},
110 {"pnp0c14", 0},
111 {"", 0},
112};
113MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
114
115static struct platform_driver acpi_wmi_driver = {
116 .driver = {
117 .name = "acpi-wmi",
118 .acpi_match_table = wmi_device_ids,
119 },
120 .probe = acpi_wmi_probe,
121 .remove = acpi_wmi_remove,
122};
123
124/*
125 * GUID parsing functions
126 */
127
128static bool find_guid(const char *guid_string, struct wmi_block **out)
129{
130 uuid_le guid_input;
131 struct wmi_block *wblock;
132 struct guid_block *block;
133
134 if (uuid_le_to_bin(guid_string, &guid_input))
135 return false;
136
137 list_for_each_entry(wblock, &wmi_block_list, list) {
138 block = &wblock->gblock;
139
140 if (memcmp(block->guid, &guid_input, 16) == 0) {
141 if (out)
142 *out = wblock;
143 return true;
144 }
145 }
146 return false;
147}
148
149static int get_subobj_info(acpi_handle handle, const char *pathname,
150 struct acpi_device_info **info)
151{
152 struct acpi_device_info *dummy_info, **info_ptr;
153 acpi_handle subobj_handle;
154 acpi_status status;
155
156 status = acpi_get_handle(handle, (char *)pathname, &subobj_handle);
157 if (status == AE_NOT_FOUND)
158 return -ENOENT;
159 else if (ACPI_FAILURE(status))
160 return -EIO;
161
162 info_ptr = info ? info : &dummy_info;
163 status = acpi_get_object_info(subobj_handle, info_ptr);
164 if (ACPI_FAILURE(status))
165 return -EIO;
166
167 if (!info)
168 kfree(dummy_info);
169
170 return 0;
171}
172
173static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable)
174{
175 struct guid_block *block = NULL;
176 char method[5];
177 acpi_status status;
178 acpi_handle handle;
179
180 block = &wblock->gblock;
181 handle = wblock->acpi_device->handle;
182
183 snprintf(method, 5, "WE%02X", block->notify_id);
184 status = acpi_execute_simple_method(handle, method, enable);
185
186 if (status != AE_OK && status != AE_NOT_FOUND)
187 return status;
188 else
189 return AE_OK;
190}
191
192/*
193 * Exported WMI functions
194 */
195
196/**
197 * set_required_buffer_size - Sets the buffer size needed for performing IOCTL
198 * @wdev: A wmi bus device from a driver
199 * @instance: Instance index
200 *
201 * Allocates memory needed for buffer, stores the buffer size in that memory
202 */
203int set_required_buffer_size(struct wmi_device *wdev, u64 length)
204{
205 struct wmi_block *wblock;
206
207 wblock = container_of(wdev, struct wmi_block, dev);
208 wblock->req_buf_size = length;
209
210 return 0;
211}
212EXPORT_SYMBOL_GPL(set_required_buffer_size);
213
214/**
215 * wmi_evaluate_method - Evaluate a WMI method
216 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
217 * @instance: Instance index
218 * @method_id: Method ID to call
219 * &in: Buffer containing input for the method call
220 * &out: Empty buffer to return the method results
221 *
222 * Call an ACPI-WMI method
223 */
224acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
225u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
226{
227 struct wmi_block *wblock = NULL;
228
229 if (!find_guid(guid_string, &wblock))
230 return AE_ERROR;
231 return wmidev_evaluate_method(&wblock->dev, instance, method_id,
232 in, out);
233}
234EXPORT_SYMBOL_GPL(wmi_evaluate_method);
235
236/**
237 * wmidev_evaluate_method - Evaluate a WMI method
238 * @wdev: A wmi bus device from a driver
239 * @instance: Instance index
240 * @method_id: Method ID to call
241 * &in: Buffer containing input for the method call
242 * &out: Empty buffer to return the method results
243 *
244 * Call an ACPI-WMI method
245 */
246acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance,
247 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
248{
249 struct guid_block *block = NULL;
250 struct wmi_block *wblock = NULL;
251 acpi_handle handle;
252 acpi_status status;
253 struct acpi_object_list input;
254 union acpi_object params[3];
255 char method[5] = "WM";
256
257 wblock = container_of(wdev, struct wmi_block, dev);
258 block = &wblock->gblock;
259 handle = wblock->acpi_device->handle;
260
261 if (!(block->flags & ACPI_WMI_METHOD))
262 return AE_BAD_DATA;
263
264 if (block->instance_count <= instance)
265 return AE_BAD_PARAMETER;
266
267 input.count = 2;
268 input.pointer = params;
269 params[0].type = ACPI_TYPE_INTEGER;
270 params[0].integer.value = instance;
271 params[1].type = ACPI_TYPE_INTEGER;
272 params[1].integer.value = method_id;
273
274 if (in) {
275 input.count = 3;
276
277 if (block->flags & ACPI_WMI_STRING) {
278 params[2].type = ACPI_TYPE_STRING;
279 } else {
280 params[2].type = ACPI_TYPE_BUFFER;
281 }
282 params[2].buffer.length = in->length;
283 params[2].buffer.pointer = in->pointer;
284 }
285
286 strncat(method, block->object_id, 2);
287
288 status = acpi_evaluate_object(handle, method, &input, out);
289
290 return status;
291}
292EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
293
294static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
295 struct acpi_buffer *out)
296{
297 struct guid_block *block = NULL;
298 acpi_handle handle;
299 acpi_status status, wc_status = AE_ERROR;
300 struct acpi_object_list input;
301 union acpi_object wq_params[1];
302 char method[5];
303 char wc_method[5] = "WC";
304
305 if (!out)
306 return AE_BAD_PARAMETER;
307
308 block = &wblock->gblock;
309 handle = wblock->acpi_device->handle;
310
311 if (block->instance_count <= instance)
312 return AE_BAD_PARAMETER;
313
314 /* Check GUID is a data block */
315 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
316 return AE_ERROR;
317
318 input.count = 1;
319 input.pointer = wq_params;
320 wq_params[0].type = ACPI_TYPE_INTEGER;
321 wq_params[0].integer.value = instance;
322
323 if (instance == 0 && wblock->read_takes_no_args)
324 input.count = 0;
325
326 /*
327 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
328 * enable collection.
329 */
330 if (block->flags & ACPI_WMI_EXPENSIVE) {
331 strncat(wc_method, block->object_id, 2);
332
333 /*
334 * Some GUIDs break the specification by declaring themselves
335 * expensive, but have no corresponding WCxx method. So we
336 * should not fail if this happens.
337 */
338 if (acpi_has_method(handle, wc_method))
339 wc_status = acpi_execute_simple_method(handle,
340 wc_method, 1);
341 }
342
343 strcpy(method, "WQ");
344 strncat(method, block->object_id, 2);
345
346 status = acpi_evaluate_object(handle, method, &input, out);
347
348 /*
349 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
350 * the WQxx method failed - we should disable collection anyway.
351 */
352 if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
353 status = acpi_execute_simple_method(handle, wc_method, 0);
354 }
355
356 return status;
357}
358
359/**
360 * wmi_query_block - Return contents of a WMI block (deprecated)
361 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
362 * @instance: Instance index
363 * &out: Empty buffer to return the contents of the data block to
364 *
365 * Return the contents of an ACPI-WMI data block to a buffer
366 */
367acpi_status wmi_query_block(const char *guid_string, u8 instance,
368 struct acpi_buffer *out)
369{
370 struct wmi_block *wblock;
371
372 if (!guid_string)
373 return AE_BAD_PARAMETER;
374
375 if (!find_guid(guid_string, &wblock))
376 return AE_ERROR;
377
378 return __query_block(wblock, instance, out);
379}
380EXPORT_SYMBOL_GPL(wmi_query_block);
381
382union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
383{
384 struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
385 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
386
387 if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
388 return NULL;
389
390 return (union acpi_object *)out.pointer;
391}
392EXPORT_SYMBOL_GPL(wmidev_block_query);
393
394/**
395 * wmi_set_block - Write to a WMI block
396 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
397 * @instance: Instance index
398 * &in: Buffer containing new values for the data block
399 *
400 * Write the contents of the input buffer to an ACPI-WMI data block
401 */
402acpi_status wmi_set_block(const char *guid_string, u8 instance,
403 const struct acpi_buffer *in)
404{
405 struct guid_block *block = NULL;
406 struct wmi_block *wblock = NULL;
407 acpi_handle handle;
408 struct acpi_object_list input;
409 union acpi_object params[2];
410 char method[5] = "WS";
411
412 if (!guid_string || !in)
413 return AE_BAD_DATA;
414
415 if (!find_guid(guid_string, &wblock))
416 return AE_ERROR;
417
418 block = &wblock->gblock;
419 handle = wblock->acpi_device->handle;
420
421 if (block->instance_count <= instance)
422 return AE_BAD_PARAMETER;
423
424 /* Check GUID is a data block */
425 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
426 return AE_ERROR;
427
428 input.count = 2;
429 input.pointer = params;
430 params[0].type = ACPI_TYPE_INTEGER;
431 params[0].integer.value = instance;
432
433 if (block->flags & ACPI_WMI_STRING) {
434 params[1].type = ACPI_TYPE_STRING;
435 } else {
436 params[1].type = ACPI_TYPE_BUFFER;
437 }
438 params[1].buffer.length = in->length;
439 params[1].buffer.pointer = in->pointer;
440
441 strncat(method, block->object_id, 2);
442
443 return acpi_evaluate_object(handle, method, &input, NULL);
444}
445EXPORT_SYMBOL_GPL(wmi_set_block);
446
447static void wmi_dump_wdg(const struct guid_block *g)
448{
449 pr_info("%pUL:\n", g->guid);
450 if (g->flags & ACPI_WMI_EVENT)
451 pr_info("\tnotify_id: 0x%02X\n", g->notify_id);
452 else
453 pr_info("\tobject_id: %2pE\n", g->object_id);
454 pr_info("\tinstance_count: %d\n", g->instance_count);
455 pr_info("\tflags: %#x", g->flags);
456 if (g->flags) {
457 if (g->flags & ACPI_WMI_EXPENSIVE)
458 pr_cont(" ACPI_WMI_EXPENSIVE");
459 if (g->flags & ACPI_WMI_METHOD)
460 pr_cont(" ACPI_WMI_METHOD");
461 if (g->flags & ACPI_WMI_STRING)
462 pr_cont(" ACPI_WMI_STRING");
463 if (g->flags & ACPI_WMI_EVENT)
464 pr_cont(" ACPI_WMI_EVENT");
465 }
466 pr_cont("\n");
467
468}
469
470static void wmi_notify_debug(u32 value, void *context)
471{
472 struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
473 union acpi_object *obj;
474 acpi_status status;
475
476 status = wmi_get_event_data(value, &response);
477 if (status != AE_OK) {
478 pr_info("bad event status 0x%x\n", status);
479 return;
480 }
481
482 obj = (union acpi_object *)response.pointer;
483
484 if (!obj)
485 return;
486
487 pr_info("DEBUG Event ");
488 switch(obj->type) {
489 case ACPI_TYPE_BUFFER:
490 pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
491 break;
492 case ACPI_TYPE_STRING:
493 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
494 break;
495 case ACPI_TYPE_INTEGER:
496 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
497 break;
498 case ACPI_TYPE_PACKAGE:
499 pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
500 break;
501 default:
502 pr_cont("object type 0x%X\n", obj->type);
503 }
504 kfree(obj);
505}
506
507/**
508 * wmi_install_notify_handler - Register handler for WMI events
509 * @handler: Function to handle notifications
510 * @data: Data to be returned to handler when event is fired
511 *
512 * Register a handler for events sent to the ACPI-WMI mapper device.
513 */
514acpi_status wmi_install_notify_handler(const char *guid,
515wmi_notify_handler handler, void *data)
516{
517 struct wmi_block *block;
518 acpi_status status = AE_NOT_EXIST;
519 uuid_le guid_input;
520
521 if (!guid || !handler)
522 return AE_BAD_PARAMETER;
523
524 if (uuid_le_to_bin(guid, &guid_input))
525 return AE_BAD_PARAMETER;
526
527 list_for_each_entry(block, &wmi_block_list, list) {
528 acpi_status wmi_status;
529
530 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
531 if (block->handler &&
532 block->handler != wmi_notify_debug)
533 return AE_ALREADY_ACQUIRED;
534
535 block->handler = handler;
536 block->handler_data = data;
537
538 wmi_status = wmi_method_enable(block, 1);
539 if ((wmi_status != AE_OK) ||
540 ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
541 status = wmi_status;
542 }
543 }
544
545 return status;
546}
547EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
548
549/**
550 * wmi_uninstall_notify_handler - Unregister handler for WMI events
551 *
552 * Unregister handler for events sent to the ACPI-WMI mapper device.
553 */
554acpi_status wmi_remove_notify_handler(const char *guid)
555{
556 struct wmi_block *block;
557 acpi_status status = AE_NOT_EXIST;
558 uuid_le guid_input;
559
560 if (!guid)
561 return AE_BAD_PARAMETER;
562
563 if (uuid_le_to_bin(guid, &guid_input))
564 return AE_BAD_PARAMETER;
565
566 list_for_each_entry(block, &wmi_block_list, list) {
567 acpi_status wmi_status;
568
569 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
570 if (!block->handler ||
571 block->handler == wmi_notify_debug)
572 return AE_NULL_ENTRY;
573
574 if (debug_event) {
575 block->handler = wmi_notify_debug;
576 status = AE_OK;
577 } else {
578 wmi_status = wmi_method_enable(block, 0);
579 block->handler = NULL;
580 block->handler_data = NULL;
581 if ((wmi_status != AE_OK) ||
582 ((wmi_status == AE_OK) &&
583 (status == AE_NOT_EXIST)))
584 status = wmi_status;
585 }
586 }
587 }
588
589 return status;
590}
591EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
592
593/**
594 * wmi_get_event_data - Get WMI data associated with an event
595 *
596 * @event: Event to find
597 * @out: Buffer to hold event data. out->pointer should be freed with kfree()
598 *
599 * Returns extra data associated with an event in WMI.
600 */
601acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
602{
603 struct acpi_object_list input;
604 union acpi_object params[1];
605 struct guid_block *gblock;
606 struct wmi_block *wblock;
607
608 input.count = 1;
609 input.pointer = params;
610 params[0].type = ACPI_TYPE_INTEGER;
611 params[0].integer.value = event;
612
613 list_for_each_entry(wblock, &wmi_block_list, list) {
614 gblock = &wblock->gblock;
615
616 if ((gblock->flags & ACPI_WMI_EVENT) &&
617 (gblock->notify_id == event))
618 return acpi_evaluate_object(wblock->acpi_device->handle,
619 "_WED", &input, out);
620 }
621
622 return AE_NOT_FOUND;
623}
624EXPORT_SYMBOL_GPL(wmi_get_event_data);
625
626/**
627 * wmi_has_guid - Check if a GUID is available
628 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
629 *
630 * Check if a given GUID is defined by _WDG
631 */
632bool wmi_has_guid(const char *guid_string)
633{
634 return find_guid(guid_string, NULL);
635}
636EXPORT_SYMBOL_GPL(wmi_has_guid);
637
638static struct wmi_block *dev_to_wblock(struct device *dev)
639{
640 return container_of(dev, struct wmi_block, dev.dev);
641}
642
643static struct wmi_device *dev_to_wdev(struct device *dev)
644{
645 return container_of(dev, struct wmi_device, dev);
646}
647
648/*
649 * sysfs interface
650 */
651static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
652 char *buf)
653{
654 struct wmi_block *wblock = dev_to_wblock(dev);
655
656 return sprintf(buf, "wmi:%pUL\n", wblock->gblock.guid);
657}
658static DEVICE_ATTR_RO(modalias);
659
660static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
661 char *buf)
662{
663 struct wmi_block *wblock = dev_to_wblock(dev);
664
665 return sprintf(buf, "%pUL\n", wblock->gblock.guid);
666}
667static DEVICE_ATTR_RO(guid);
668
669static ssize_t instance_count_show(struct device *dev,
670 struct device_attribute *attr, char *buf)
671{
672 struct wmi_block *wblock = dev_to_wblock(dev);
673
674 return sprintf(buf, "%d\n", (int)wblock->gblock.instance_count);
675}
676static DEVICE_ATTR_RO(instance_count);
677
678static ssize_t expensive_show(struct device *dev,
679 struct device_attribute *attr, char *buf)
680{
681 struct wmi_block *wblock = dev_to_wblock(dev);
682
683 return sprintf(buf, "%d\n",
684 (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
685}
686static DEVICE_ATTR_RO(expensive);
687
688static struct attribute *wmi_attrs[] = {
689 &dev_attr_modalias.attr,
690 &dev_attr_guid.attr,
691 &dev_attr_instance_count.attr,
692 &dev_attr_expensive.attr,
693 NULL,
694};
695ATTRIBUTE_GROUPS(wmi);
696
697static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
698 char *buf)
699{
700 struct wmi_block *wblock = dev_to_wblock(dev);
701
702 return sprintf(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
703}
704static DEVICE_ATTR_RO(notify_id);
705
706static struct attribute *wmi_event_attrs[] = {
707 &dev_attr_notify_id.attr,
708 NULL,
709};
710ATTRIBUTE_GROUPS(wmi_event);
711
712static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
713 char *buf)
714{
715 struct wmi_block *wblock = dev_to_wblock(dev);
716
717 return sprintf(buf, "%c%c\n", wblock->gblock.object_id[0],
718 wblock->gblock.object_id[1]);
719}
720static DEVICE_ATTR_RO(object_id);
721
722static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
723 char *buf)
724{
725 struct wmi_device *wdev = dev_to_wdev(dev);
726
727 return sprintf(buf, "%d\n", (int)wdev->setable);
728}
729static DEVICE_ATTR_RO(setable);
730
731static struct attribute *wmi_data_attrs[] = {
732 &dev_attr_object_id.attr,
733 &dev_attr_setable.attr,
734 NULL,
735};
736ATTRIBUTE_GROUPS(wmi_data);
737
738static struct attribute *wmi_method_attrs[] = {
739 &dev_attr_object_id.attr,
740 NULL,
741};
742ATTRIBUTE_GROUPS(wmi_method);
743
744static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
745{
746 struct wmi_block *wblock = dev_to_wblock(dev);
747
748 if (add_uevent_var(env, "MODALIAS=wmi:%pUL", wblock->gblock.guid))
749 return -ENOMEM;
750
751 if (add_uevent_var(env, "WMI_GUID=%pUL", wblock->gblock.guid))
752 return -ENOMEM;
753
754 return 0;
755}
756
757static void wmi_dev_release(struct device *dev)
758{
759 struct wmi_block *wblock = dev_to_wblock(dev);
760
761 kfree(wblock);
762}
763
764static int wmi_dev_match(struct device *dev, struct device_driver *driver)
765{
766 struct wmi_driver *wmi_driver =
767 container_of(driver, struct wmi_driver, driver);
768 struct wmi_block *wblock = dev_to_wblock(dev);
769 const struct wmi_device_id *id = wmi_driver->id_table;
770
771 while (id->guid_string) {
772 uuid_le driver_guid;
773
774 if (WARN_ON(uuid_le_to_bin(id->guid_string, &driver_guid)))
775 continue;
776 if (!memcmp(&driver_guid, wblock->gblock.guid, 16))
777 return 1;
778
779 id++;
780 }
781
782 return 0;
783}
784static int wmi_char_open(struct inode *inode, struct file *filp)
785{
786 const char *driver_name = filp->f_path.dentry->d_iname;
787 struct wmi_block *wblock = NULL;
788 struct wmi_block *next = NULL;
789
790 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
791 if (!wblock->dev.dev.driver)
792 continue;
793 if (strcmp(driver_name, wblock->dev.dev.driver->name) == 0) {
794 filp->private_data = wblock;
795 break;
796 }
797 }
798
799 if (!filp->private_data)
800 return -ENODEV;
801
802 return nonseekable_open(inode, filp);
803}
804
805static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
806 size_t length, loff_t *offset)
807{
808 struct wmi_block *wblock = filp->private_data;
809
810 return simple_read_from_buffer(buffer, length, offset,
811 &wblock->req_buf_size,
812 sizeof(wblock->req_buf_size));
813}
814
815static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
816{
817 struct wmi_ioctl_buffer __user *input =
818 (struct wmi_ioctl_buffer __user *) arg;
819 struct wmi_block *wblock = filp->private_data;
820 struct wmi_ioctl_buffer *buf = NULL;
821 struct wmi_driver *wdriver = NULL;
822 int ret;
823
824 if (_IOC_TYPE(cmd) != WMI_IOC)
825 return -ENOTTY;
826
827 /* make sure we're not calling a higher instance than exists*/
828 if (_IOC_NR(cmd) >= wblock->gblock.instance_count)
829 return -EINVAL;
830
831 mutex_lock(&wblock->char_mutex);
832 buf = wblock->handler_data;
833 if (get_user(buf->length, &input->length)) {
834 dev_dbg(&wblock->dev.dev, "Read length from user failed\n");
835 ret = -EFAULT;
836 goto out_ioctl;
837 }
838 /* if it's too small, abort */
839 if (buf->length < wblock->req_buf_size) {
840 dev_err(&wblock->dev.dev,
841 "Buffer %lld too small, need at least %lld\n",
842 buf->length, wblock->req_buf_size);
843 ret = -EINVAL;
844 goto out_ioctl;
845 }
846 /* if it's too big, warn, driver will only use what is needed */
847 if (buf->length > wblock->req_buf_size)
848 dev_warn(&wblock->dev.dev,
849 "Buffer %lld is bigger than required %lld\n",
850 buf->length, wblock->req_buf_size);
851
852 /* copy the structure from userspace */
853 if (copy_from_user(buf, input, wblock->req_buf_size)) {
854 dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n",
855 wblock->req_buf_size);
856 ret = -EFAULT;
857 goto out_ioctl;
858 }
859
860 /* let the driver do any filtering and do the call */
861 wdriver = container_of(wblock->dev.dev.driver,
862 struct wmi_driver, driver);
863 if (!try_module_get(wdriver->driver.owner)) {
864 ret = -EBUSY;
865 goto out_ioctl;
866 }
867 ret = wdriver->filter_callback(&wblock->dev, cmd, buf);
868 module_put(wdriver->driver.owner);
869 if (ret)
870 goto out_ioctl;
871
872 /* return the result (only up to our internal buffer size) */
873 if (copy_to_user(input, buf, wblock->req_buf_size)) {
874 dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n",
875 wblock->req_buf_size);
876 ret = -EFAULT;
877 }
878
879out_ioctl:
880 mutex_unlock(&wblock->char_mutex);
881 return ret;
882}
883
884static const struct file_operations wmi_fops = {
885 .owner = THIS_MODULE,
886 .read = wmi_char_read,
887 .open = wmi_char_open,
888 .unlocked_ioctl = wmi_ioctl,
889 .compat_ioctl = wmi_ioctl,
890};
891
892static int wmi_dev_probe(struct device *dev)
893{
894 struct wmi_block *wblock = dev_to_wblock(dev);
895 struct wmi_driver *wdriver =
896 container_of(dev->driver, struct wmi_driver, driver);
897 int ret = 0;
898 int count;
899 char *buf;
900
901 if (ACPI_FAILURE(wmi_method_enable(wblock, 1)))
902 dev_warn(dev, "failed to enable device -- probing anyway\n");
903
904 if (wdriver->probe) {
905 ret = wdriver->probe(dev_to_wdev(dev));
906 if (ret != 0)
907 goto probe_failure;
908 }
909
910 /* driver wants a character device made */
911 if (wdriver->filter_callback) {
912 /* check that required buffer size declared by driver or MOF */
913 if (!wblock->req_buf_size) {
914 dev_err(&wblock->dev.dev,
915 "Required buffer size not set\n");
916 ret = -EINVAL;
917 goto probe_failure;
918 }
919
920 count = get_order(wblock->req_buf_size);
921 wblock->handler_data = (void *)__get_free_pages(GFP_KERNEL,
922 count);
923 if (!wblock->handler_data) {
924 ret = -ENOMEM;
925 goto probe_failure;
926 }
927
928 buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name);
929 if (!buf) {
930 ret = -ENOMEM;
931 goto probe_string_failure;
932 }
933 wblock->char_dev.minor = MISC_DYNAMIC_MINOR;
934 wblock->char_dev.name = buf;
935 wblock->char_dev.fops = &wmi_fops;
936 wblock->char_dev.mode = 0444;
937 ret = misc_register(&wblock->char_dev);
938 if (ret) {
939 dev_warn(dev, "failed to register char dev: %d\n", ret);
940 ret = -ENOMEM;
941 goto probe_misc_failure;
942 }
943 }
944
945 return 0;
946
947probe_misc_failure:
948 kfree(buf);
949probe_string_failure:
950 kfree(wblock->handler_data);
951probe_failure:
952 if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
953 dev_warn(dev, "failed to disable device\n");
954 return ret;
955}
956
957static int wmi_dev_remove(struct device *dev)
958{
959 struct wmi_block *wblock = dev_to_wblock(dev);
960 struct wmi_driver *wdriver =
961 container_of(dev->driver, struct wmi_driver, driver);
962 int ret = 0;
963
964 if (wdriver->filter_callback) {
965 misc_deregister(&wblock->char_dev);
966 kfree(wblock->char_dev.name);
967 free_pages((unsigned long)wblock->handler_data,
968 get_order(wblock->req_buf_size));
969 }
970
971 if (wdriver->remove)
972 ret = wdriver->remove(dev_to_wdev(dev));
973
974 if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
975 dev_warn(dev, "failed to disable device\n");
976
977 return ret;
978}
979
980static struct class wmi_bus_class = {
981 .name = "wmi_bus",
982};
983
984static struct bus_type wmi_bus_type = {
985 .name = "wmi",
986 .dev_groups = wmi_groups,
987 .match = wmi_dev_match,
988 .uevent = wmi_dev_uevent,
989 .probe = wmi_dev_probe,
990 .remove = wmi_dev_remove,
991};
992
993static struct device_type wmi_type_event = {
994 .name = "event",
995 .groups = wmi_event_groups,
996 .release = wmi_dev_release,
997};
998
999static struct device_type wmi_type_method = {
1000 .name = "method",
1001 .groups = wmi_method_groups,
1002 .release = wmi_dev_release,
1003};
1004
1005static struct device_type wmi_type_data = {
1006 .name = "data",
1007 .groups = wmi_data_groups,
1008 .release = wmi_dev_release,
1009};
1010
1011static int wmi_create_device(struct device *wmi_bus_dev,
1012 const struct guid_block *gblock,
1013 struct wmi_block *wblock,
1014 struct acpi_device *device)
1015{
1016 struct acpi_device_info *info;
1017 char method[5];
1018 int result;
1019
1020 if (gblock->flags & ACPI_WMI_EVENT) {
1021 wblock->dev.dev.type = &wmi_type_event;
1022 goto out_init;
1023 }
1024
1025 if (gblock->flags & ACPI_WMI_METHOD) {
1026 wblock->dev.dev.type = &wmi_type_method;
1027 mutex_init(&wblock->char_mutex);
1028 goto out_init;
1029 }
1030
1031 /*
1032 * Data Block Query Control Method (WQxx by convention) is
1033 * required per the WMI documentation. If it is not present,
1034 * we ignore this data block.
1035 */
1036 strcpy(method, "WQ");
1037 strncat(method, wblock->gblock.object_id, 2);
1038 result = get_subobj_info(device->handle, method, &info);
1039
1040 if (result) {
1041 dev_warn(wmi_bus_dev,
1042 "%s data block query control method not found\n",
1043 method);
1044 return result;
1045 }
1046
1047 wblock->dev.dev.type = &wmi_type_data;
1048
1049 /*
1050 * The Microsoft documentation specifically states:
1051 *
1052 * Data blocks registered with only a single instance
1053 * can ignore the parameter.
1054 *
1055 * ACPICA will get mad at us if we call the method with the wrong number
1056 * of arguments, so check what our method expects. (On some Dell
1057 * laptops, WQxx may not be a method at all.)
1058 */
1059 if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1060 wblock->read_takes_no_args = true;
1061
1062 kfree(info);
1063
1064 strcpy(method, "WS");
1065 strncat(method, wblock->gblock.object_id, 2);
1066 result = get_subobj_info(device->handle, method, NULL);
1067
1068 if (result == 0)
1069 wblock->dev.setable = true;
1070
1071 out_init:
1072 wblock->dev.dev.bus = &wmi_bus_type;
1073 wblock->dev.dev.parent = wmi_bus_dev;
1074
1075 dev_set_name(&wblock->dev.dev, "%pUL", gblock->guid);
1076
1077 device_initialize(&wblock->dev.dev);
1078
1079 return 0;
1080}
1081
1082static void wmi_free_devices(struct acpi_device *device)
1083{
1084 struct wmi_block *wblock, *next;
1085
1086 /* Delete devices for all the GUIDs */
1087 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1088 if (wblock->acpi_device == device) {
1089 list_del(&wblock->list);
1090 device_unregister(&wblock->dev.dev);
1091 }
1092 }
1093}
1094
1095static bool guid_already_parsed(struct acpi_device *device,
1096 const u8 *guid)
1097{
1098 struct wmi_block *wblock;
1099
1100 list_for_each_entry(wblock, &wmi_block_list, list) {
1101 if (memcmp(wblock->gblock.guid, guid, 16) == 0) {
1102 /*
1103 * Because we historically didn't track the relationship
1104 * between GUIDs and ACPI nodes, we don't know whether
1105 * we need to suppress GUIDs that are unique on a
1106 * given node but duplicated across nodes.
1107 */
1108 dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
1109 guid, dev_name(&wblock->acpi_device->dev));
1110 return true;
1111 }
1112 }
1113
1114 return false;
1115}
1116
1117/*
1118 * Parse the _WDG method for the GUID data blocks
1119 */
1120static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
1121{
1122 struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1123 const struct guid_block *gblock;
1124 struct wmi_block *wblock, *next;
1125 union acpi_object *obj;
1126 acpi_status status;
1127 int retval = 0;
1128 u32 i, total;
1129
1130 status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1131 if (ACPI_FAILURE(status))
1132 return -ENXIO;
1133
1134 obj = (union acpi_object *) out.pointer;
1135 if (!obj)
1136 return -ENXIO;
1137
1138 if (obj->type != ACPI_TYPE_BUFFER) {
1139 retval = -ENXIO;
1140 goto out_free_pointer;
1141 }
1142
1143 gblock = (const struct guid_block *)obj->buffer.pointer;
1144 total = obj->buffer.length / sizeof(struct guid_block);
1145
1146 for (i = 0; i < total; i++) {
1147 if (debug_dump_wdg)
1148 wmi_dump_wdg(&gblock[i]);
1149
1150 /*
1151 * Some WMI devices, like those for nVidia hooks, have a
1152 * duplicate GUID. It's not clear what we should do in this
1153 * case yet, so for now, we'll just ignore the duplicate
1154 * for device creation.
1155 */
1156 if (guid_already_parsed(device, gblock[i].guid))
1157 continue;
1158
1159 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
1160 if (!wblock) {
1161 retval = -ENOMEM;
1162 break;
1163 }
1164
1165 wblock->acpi_device = device;
1166 wblock->gblock = gblock[i];
1167
1168 retval = wmi_create_device(wmi_bus_dev, &gblock[i], wblock, device);
1169 if (retval) {
1170 kfree(wblock);
1171 continue;
1172 }
1173
1174 list_add_tail(&wblock->list, &wmi_block_list);
1175
1176 if (debug_event) {
1177 wblock->handler = wmi_notify_debug;
1178 wmi_method_enable(wblock, 1);
1179 }
1180 }
1181
1182 /*
1183 * Now that all of the devices are created, add them to the
1184 * device tree and probe subdrivers.
1185 */
1186 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1187 if (wblock->acpi_device != device)
1188 continue;
1189
1190 retval = device_add(&wblock->dev.dev);
1191 if (retval) {
1192 dev_err(wmi_bus_dev, "failed to register %pUL\n",
1193 wblock->gblock.guid);
1194 if (debug_event)
1195 wmi_method_enable(wblock, 0);
1196 list_del(&wblock->list);
1197 put_device(&wblock->dev.dev);
1198 }
1199 }
1200
1201out_free_pointer:
1202 kfree(out.pointer);
1203 return retval;
1204}
1205
1206/*
1207 * WMI can have EmbeddedControl access regions. In which case, we just want to
1208 * hand these off to the EC driver.
1209 */
1210static acpi_status
1211acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1212 u32 bits, u64 *value,
1213 void *handler_context, void *region_context)
1214{
1215 int result = 0, i = 0;
1216 u8 temp = 0;
1217
1218 if ((address > 0xFF) || !value)
1219 return AE_BAD_PARAMETER;
1220
1221 if (function != ACPI_READ && function != ACPI_WRITE)
1222 return AE_BAD_PARAMETER;
1223
1224 if (bits != 8)
1225 return AE_BAD_PARAMETER;
1226
1227 if (function == ACPI_READ) {
1228 result = ec_read(address, &temp);
1229 (*value) |= ((u64)temp) << i;
1230 } else {
1231 temp = 0xff & ((*value) >> i);
1232 result = ec_write(address, temp);
1233 }
1234
1235 switch (result) {
1236 case -EINVAL:
1237 return AE_BAD_PARAMETER;
1238 break;
1239 case -ENODEV:
1240 return AE_NOT_FOUND;
1241 break;
1242 case -ETIME:
1243 return AE_TIME;
1244 break;
1245 default:
1246 return AE_OK;
1247 }
1248}
1249
1250static void acpi_wmi_notify_handler(acpi_handle handle, u32 event,
1251 void *context)
1252{
1253 struct guid_block *block;
1254 struct wmi_block *wblock;
1255 bool found_it = false;
1256
1257 list_for_each_entry(wblock, &wmi_block_list, list) {
1258 block = &wblock->gblock;
1259
1260 if (wblock->acpi_device->handle == handle &&
1261 (block->flags & ACPI_WMI_EVENT) &&
1262 (block->notify_id == event))
1263 {
1264 found_it = true;
1265 break;
1266 }
1267 }
1268
1269 if (!found_it)
1270 return;
1271
1272 /* If a driver is bound, then notify the driver. */
1273 if (wblock->dev.dev.driver) {
1274 struct wmi_driver *driver;
1275 struct acpi_object_list input;
1276 union acpi_object params[1];
1277 struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL };
1278 acpi_status status;
1279
1280 driver = container_of(wblock->dev.dev.driver,
1281 struct wmi_driver, driver);
1282
1283 input.count = 1;
1284 input.pointer = params;
1285 params[0].type = ACPI_TYPE_INTEGER;
1286 params[0].integer.value = event;
1287
1288 status = acpi_evaluate_object(wblock->acpi_device->handle,
1289 "_WED", &input, &evdata);
1290 if (ACPI_FAILURE(status)) {
1291 dev_warn(&wblock->dev.dev,
1292 "failed to get event data\n");
1293 return;
1294 }
1295
1296 if (driver->notify)
1297 driver->notify(&wblock->dev,
1298 (union acpi_object *)evdata.pointer);
1299
1300 kfree(evdata.pointer);
1301 } else if (wblock->handler) {
1302 /* Legacy handler */
1303 wblock->handler(event, wblock->handler_data);
1304 }
1305
1306 if (debug_event) {
1307 pr_info("DEBUG Event GUID: %pUL\n",
1308 wblock->gblock.guid);
1309 }
1310
1311 acpi_bus_generate_netlink_event(
1312 wblock->acpi_device->pnp.device_class,
1313 dev_name(&wblock->dev.dev),
1314 event, 0);
1315
1316}
1317
1318static int acpi_wmi_remove(struct platform_device *device)
1319{
1320 struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev);
1321
1322 acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1323 acpi_wmi_notify_handler);
1324 acpi_remove_address_space_handler(acpi_device->handle,
1325 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
1326 wmi_free_devices(acpi_device);
1327 device_destroy(&wmi_bus_class, MKDEV(0, 0));
1328
1329 return 0;
1330}
1331
1332static int acpi_wmi_probe(struct platform_device *device)
1333{
1334 struct acpi_device *acpi_device;
1335 struct device *wmi_bus_dev;
1336 acpi_status status;
1337 int error;
1338
1339 acpi_device = ACPI_COMPANION(&device->dev);
1340 if (!acpi_device) {
1341 dev_err(&device->dev, "ACPI companion is missing\n");
1342 return -ENODEV;
1343 }
1344
1345 status = acpi_install_address_space_handler(acpi_device->handle,
1346 ACPI_ADR_SPACE_EC,
1347 &acpi_wmi_ec_space_handler,
1348 NULL, NULL);
1349 if (ACPI_FAILURE(status)) {
1350 dev_err(&device->dev, "Error installing EC region handler\n");
1351 return -ENODEV;
1352 }
1353
1354 status = acpi_install_notify_handler(acpi_device->handle,
1355 ACPI_DEVICE_NOTIFY,
1356 acpi_wmi_notify_handler,
1357 NULL);
1358 if (ACPI_FAILURE(status)) {
1359 dev_err(&device->dev, "Error installing notify handler\n");
1360 error = -ENODEV;
1361 goto err_remove_ec_handler;
1362 }
1363
1364 wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0),
1365 NULL, "wmi_bus-%s", dev_name(&device->dev));
1366 if (IS_ERR(wmi_bus_dev)) {
1367 error = PTR_ERR(wmi_bus_dev);
1368 goto err_remove_notify_handler;
1369 }
1370 dev_set_drvdata(&device->dev, wmi_bus_dev);
1371
1372 error = parse_wdg(wmi_bus_dev, acpi_device);
1373 if (error) {
1374 pr_err("Failed to parse WDG method\n");
1375 goto err_remove_busdev;
1376 }
1377
1378 return 0;
1379
1380err_remove_busdev:
1381 device_destroy(&wmi_bus_class, MKDEV(0, 0));
1382
1383err_remove_notify_handler:
1384 acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1385 acpi_wmi_notify_handler);
1386
1387err_remove_ec_handler:
1388 acpi_remove_address_space_handler(acpi_device->handle,
1389 ACPI_ADR_SPACE_EC,
1390 &acpi_wmi_ec_space_handler);
1391
1392 return error;
1393}
1394
1395int __must_check __wmi_driver_register(struct wmi_driver *driver,
1396 struct module *owner)
1397{
1398 driver->driver.owner = owner;
1399 driver->driver.bus = &wmi_bus_type;
1400
1401 return driver_register(&driver->driver);
1402}
1403EXPORT_SYMBOL(__wmi_driver_register);
1404
1405void wmi_driver_unregister(struct wmi_driver *driver)
1406{
1407 driver_unregister(&driver->driver);
1408}
1409EXPORT_SYMBOL(wmi_driver_unregister);
1410
1411static int __init acpi_wmi_init(void)
1412{
1413 int error;
1414
1415 if (acpi_disabled)
1416 return -ENODEV;
1417
1418 error = class_register(&wmi_bus_class);
1419 if (error)
1420 return error;
1421
1422 error = bus_register(&wmi_bus_type);
1423 if (error)
1424 goto err_unreg_class;
1425
1426 error = platform_driver_register(&acpi_wmi_driver);
1427 if (error) {
1428 pr_err("Error loading mapper\n");
1429 goto err_unreg_bus;
1430 }
1431
1432 return 0;
1433
1434err_unreg_bus:
1435 bus_unregister(&wmi_bus_type);
1436
1437err_unreg_class:
1438 class_unregister(&wmi_bus_class);
1439
1440 return error;
1441}
1442
1443static void __exit acpi_wmi_exit(void)
1444{
1445 platform_driver_unregister(&acpi_wmi_driver);
1446 bus_unregister(&wmi_bus_type);
1447 class_unregister(&wmi_bus_class);
1448}
1449
1450subsys_initcall_sync(acpi_wmi_init);
1451module_exit(acpi_wmi_exit);