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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * ACPI-WMI mapping driver
4 *
5 * Copyright (C) 2007-2008 Carlos Corbacho <carlos@strangeworlds.co.uk>
6 *
7 * GUID parsing code from ldm.c is:
8 * Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
9 * Copyright (c) 2001-2007 Anton Altaparmakov
10 * Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
11 *
12 * WMI bus infrastructure by Andrew Lutomirski and Darren Hart:
13 * Copyright (C) 2015 Andrew Lutomirski
14 * Copyright (C) 2017 VMware, Inc. All Rights Reserved.
15 */
16
17#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18
19#include <linux/acpi.h>
20#include <linux/device.h>
21#include <linux/init.h>
22#include <linux/kernel.h>
23#include <linux/list.h>
24#include <linux/miscdevice.h>
25#include <linux/module.h>
26#include <linux/platform_device.h>
27#include <linux/slab.h>
28#include <linux/types.h>
29#include <linux/uaccess.h>
30#include <linux/uuid.h>
31#include <linux/wmi.h>
32#include <linux/fs.h>
33#include <uapi/linux/wmi.h>
34
35ACPI_MODULE_NAME("wmi");
36MODULE_AUTHOR("Carlos Corbacho");
37MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
38MODULE_LICENSE("GPL");
39
40static LIST_HEAD(wmi_block_list);
41
42struct guid_block {
43 char guid[16];
44 union {
45 char object_id[2];
46 struct {
47 unsigned char notify_id;
48 unsigned char reserved;
49 };
50 };
51 u8 instance_count;
52 u8 flags;
53};
54
55struct wmi_block {
56 struct wmi_device dev;
57 struct list_head list;
58 struct guid_block gblock;
59 struct miscdevice char_dev;
60 struct mutex char_mutex;
61 struct acpi_device *acpi_device;
62 wmi_notify_handler handler;
63 void *handler_data;
64 u64 req_buf_size;
65
66 bool read_takes_no_args;
67};
68
69
70/*
71 * If the GUID data block is marked as expensive, we must enable and
72 * explicitily disable data collection.
73 */
74#define ACPI_WMI_EXPENSIVE 0x1
75#define ACPI_WMI_METHOD 0x2 /* GUID is a method */
76#define ACPI_WMI_STRING 0x4 /* GUID takes & returns a string */
77#define ACPI_WMI_EVENT 0x8 /* GUID is an event */
78
79static bool debug_event;
80module_param(debug_event, bool, 0444);
81MODULE_PARM_DESC(debug_event,
82 "Log WMI Events [0/1]");
83
84static bool debug_dump_wdg;
85module_param(debug_dump_wdg, bool, 0444);
86MODULE_PARM_DESC(debug_dump_wdg,
87 "Dump available WMI interfaces [0/1]");
88
89static int acpi_wmi_remove(struct platform_device *device);
90static int acpi_wmi_probe(struct platform_device *device);
91
92static const struct acpi_device_id wmi_device_ids[] = {
93 {"PNP0C14", 0},
94 {"pnp0c14", 0},
95 {"", 0},
96};
97MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
98
99static struct platform_driver acpi_wmi_driver = {
100 .driver = {
101 .name = "acpi-wmi",
102 .acpi_match_table = wmi_device_ids,
103 },
104 .probe = acpi_wmi_probe,
105 .remove = acpi_wmi_remove,
106};
107
108/*
109 * GUID parsing functions
110 */
111
112static bool find_guid(const char *guid_string, struct wmi_block **out)
113{
114 guid_t guid_input;
115 struct wmi_block *wblock;
116 struct guid_block *block;
117
118 if (guid_parse(guid_string, &guid_input))
119 return false;
120
121 list_for_each_entry(wblock, &wmi_block_list, list) {
122 block = &wblock->gblock;
123
124 if (memcmp(block->guid, &guid_input, 16) == 0) {
125 if (out)
126 *out = wblock;
127 return true;
128 }
129 }
130 return false;
131}
132
133static const void *find_guid_context(struct wmi_block *wblock,
134 struct wmi_driver *wdriver)
135{
136 const struct wmi_device_id *id;
137 guid_t guid_input;
138
139 if (wblock == NULL || wdriver == NULL)
140 return NULL;
141 if (wdriver->id_table == NULL)
142 return NULL;
143
144 id = wdriver->id_table;
145 while (*id->guid_string) {
146 if (guid_parse(id->guid_string, &guid_input))
147 continue;
148 if (!memcmp(wblock->gblock.guid, &guid_input, 16))
149 return id->context;
150 id++;
151 }
152 return NULL;
153}
154
155static int get_subobj_info(acpi_handle handle, const char *pathname,
156 struct acpi_device_info **info)
157{
158 struct acpi_device_info *dummy_info, **info_ptr;
159 acpi_handle subobj_handle;
160 acpi_status status;
161
162 status = acpi_get_handle(handle, (char *)pathname, &subobj_handle);
163 if (status == AE_NOT_FOUND)
164 return -ENOENT;
165 else if (ACPI_FAILURE(status))
166 return -EIO;
167
168 info_ptr = info ? info : &dummy_info;
169 status = acpi_get_object_info(subobj_handle, info_ptr);
170 if (ACPI_FAILURE(status))
171 return -EIO;
172
173 if (!info)
174 kfree(dummy_info);
175
176 return 0;
177}
178
179static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable)
180{
181 struct guid_block *block = NULL;
182 char method[5];
183 acpi_status status;
184 acpi_handle handle;
185
186 block = &wblock->gblock;
187 handle = wblock->acpi_device->handle;
188
189 snprintf(method, 5, "WE%02X", block->notify_id);
190 status = acpi_execute_simple_method(handle, method, enable);
191
192 if (status != AE_OK && status != AE_NOT_FOUND)
193 return status;
194 else
195 return AE_OK;
196}
197
198/*
199 * Exported WMI functions
200 */
201
202/**
203 * set_required_buffer_size - Sets the buffer size needed for performing IOCTL
204 * @wdev: A wmi bus device from a driver
205 * @length: Required buffer size
206 *
207 * Allocates memory needed for buffer, stores the buffer size in that memory
208 */
209int set_required_buffer_size(struct wmi_device *wdev, u64 length)
210{
211 struct wmi_block *wblock;
212
213 wblock = container_of(wdev, struct wmi_block, dev);
214 wblock->req_buf_size = length;
215
216 return 0;
217}
218EXPORT_SYMBOL_GPL(set_required_buffer_size);
219
220/**
221 * wmi_evaluate_method - Evaluate a WMI method
222 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
223 * @instance: Instance index
224 * @method_id: Method ID to call
225 * @in: Buffer containing input for the method call
226 * @out: Empty buffer to return the method results
227 *
228 * Call an ACPI-WMI method
229 */
230acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
231u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
232{
233 struct wmi_block *wblock = NULL;
234
235 if (!find_guid(guid_string, &wblock))
236 return AE_ERROR;
237 return wmidev_evaluate_method(&wblock->dev, instance, method_id,
238 in, out);
239}
240EXPORT_SYMBOL_GPL(wmi_evaluate_method);
241
242/**
243 * wmidev_evaluate_method - Evaluate a WMI method
244 * @wdev: A wmi bus device from a driver
245 * @instance: Instance index
246 * @method_id: Method ID to call
247 * @in: Buffer containing input for the method call
248 * @out: Empty buffer to return the method results
249 *
250 * Call an ACPI-WMI method
251 */
252acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance,
253 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
254{
255 struct guid_block *block = NULL;
256 struct wmi_block *wblock = NULL;
257 acpi_handle handle;
258 acpi_status status;
259 struct acpi_object_list input;
260 union acpi_object params[3];
261 char method[5] = "WM";
262
263 wblock = container_of(wdev, struct wmi_block, dev);
264 block = &wblock->gblock;
265 handle = wblock->acpi_device->handle;
266
267 if (!(block->flags & ACPI_WMI_METHOD))
268 return AE_BAD_DATA;
269
270 if (block->instance_count <= instance)
271 return AE_BAD_PARAMETER;
272
273 input.count = 2;
274 input.pointer = params;
275 params[0].type = ACPI_TYPE_INTEGER;
276 params[0].integer.value = instance;
277 params[1].type = ACPI_TYPE_INTEGER;
278 params[1].integer.value = method_id;
279
280 if (in) {
281 input.count = 3;
282
283 if (block->flags & ACPI_WMI_STRING) {
284 params[2].type = ACPI_TYPE_STRING;
285 } else {
286 params[2].type = ACPI_TYPE_BUFFER;
287 }
288 params[2].buffer.length = in->length;
289 params[2].buffer.pointer = in->pointer;
290 }
291
292 strncat(method, block->object_id, 2);
293
294 status = acpi_evaluate_object(handle, method, &input, out);
295
296 return status;
297}
298EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
299
300static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
301 struct acpi_buffer *out)
302{
303 struct guid_block *block = NULL;
304 acpi_handle handle;
305 acpi_status status, wc_status = AE_ERROR;
306 struct acpi_object_list input;
307 union acpi_object wq_params[1];
308 char method[5];
309 char wc_method[5] = "WC";
310
311 if (!out)
312 return AE_BAD_PARAMETER;
313
314 block = &wblock->gblock;
315 handle = wblock->acpi_device->handle;
316
317 if (block->instance_count <= instance)
318 return AE_BAD_PARAMETER;
319
320 /* Check GUID is a data block */
321 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
322 return AE_ERROR;
323
324 input.count = 1;
325 input.pointer = wq_params;
326 wq_params[0].type = ACPI_TYPE_INTEGER;
327 wq_params[0].integer.value = instance;
328
329 if (instance == 0 && wblock->read_takes_no_args)
330 input.count = 0;
331
332 /*
333 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
334 * enable collection.
335 */
336 if (block->flags & ACPI_WMI_EXPENSIVE) {
337 strncat(wc_method, block->object_id, 2);
338
339 /*
340 * Some GUIDs break the specification by declaring themselves
341 * expensive, but have no corresponding WCxx method. So we
342 * should not fail if this happens.
343 */
344 wc_status = acpi_execute_simple_method(handle, wc_method, 1);
345 }
346
347 strcpy(method, "WQ");
348 strncat(method, block->object_id, 2);
349
350 status = acpi_evaluate_object(handle, method, &input, out);
351
352 /*
353 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
354 * the WQxx method failed - we should disable collection anyway.
355 */
356 if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
357 status = acpi_execute_simple_method(handle, wc_method, 0);
358 }
359
360 return status;
361}
362
363/**
364 * wmi_query_block - Return contents of a WMI block (deprecated)
365 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
366 * @instance: Instance index
367 * @out: Empty buffer to return the contents of the data block to
368 *
369 * Return the contents of an ACPI-WMI data block to a buffer
370 */
371acpi_status wmi_query_block(const char *guid_string, u8 instance,
372 struct acpi_buffer *out)
373{
374 struct wmi_block *wblock;
375
376 if (!guid_string)
377 return AE_BAD_PARAMETER;
378
379 if (!find_guid(guid_string, &wblock))
380 return AE_ERROR;
381
382 return __query_block(wblock, instance, out);
383}
384EXPORT_SYMBOL_GPL(wmi_query_block);
385
386union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
387{
388 struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
389 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
390
391 if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
392 return NULL;
393
394 return (union acpi_object *)out.pointer;
395}
396EXPORT_SYMBOL_GPL(wmidev_block_query);
397
398/**
399 * wmi_set_block - Write to a WMI block
400 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
401 * @instance: Instance index
402 * @in: Buffer containing new values for the data block
403 *
404 * Write the contents of the input buffer to an ACPI-WMI data block
405 */
406acpi_status wmi_set_block(const char *guid_string, u8 instance,
407 const struct acpi_buffer *in)
408{
409 struct guid_block *block = NULL;
410 struct wmi_block *wblock = NULL;
411 acpi_handle handle;
412 struct acpi_object_list input;
413 union acpi_object params[2];
414 char method[5] = "WS";
415
416 if (!guid_string || !in)
417 return AE_BAD_DATA;
418
419 if (!find_guid(guid_string, &wblock))
420 return AE_ERROR;
421
422 block = &wblock->gblock;
423 handle = wblock->acpi_device->handle;
424
425 if (block->instance_count <= instance)
426 return AE_BAD_PARAMETER;
427
428 /* Check GUID is a data block */
429 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
430 return AE_ERROR;
431
432 input.count = 2;
433 input.pointer = params;
434 params[0].type = ACPI_TYPE_INTEGER;
435 params[0].integer.value = instance;
436
437 if (block->flags & ACPI_WMI_STRING) {
438 params[1].type = ACPI_TYPE_STRING;
439 } else {
440 params[1].type = ACPI_TYPE_BUFFER;
441 }
442 params[1].buffer.length = in->length;
443 params[1].buffer.pointer = in->pointer;
444
445 strncat(method, block->object_id, 2);
446
447 return acpi_evaluate_object(handle, method, &input, NULL);
448}
449EXPORT_SYMBOL_GPL(wmi_set_block);
450
451static void wmi_dump_wdg(const struct guid_block *g)
452{
453 pr_info("%pUL:\n", g->guid);
454 if (g->flags & ACPI_WMI_EVENT)
455 pr_info("\tnotify_id: 0x%02X\n", g->notify_id);
456 else
457 pr_info("\tobject_id: %2pE\n", g->object_id);
458 pr_info("\tinstance_count: %d\n", g->instance_count);
459 pr_info("\tflags: %#x", g->flags);
460 if (g->flags) {
461 if (g->flags & ACPI_WMI_EXPENSIVE)
462 pr_cont(" ACPI_WMI_EXPENSIVE");
463 if (g->flags & ACPI_WMI_METHOD)
464 pr_cont(" ACPI_WMI_METHOD");
465 if (g->flags & ACPI_WMI_STRING)
466 pr_cont(" ACPI_WMI_STRING");
467 if (g->flags & ACPI_WMI_EVENT)
468 pr_cont(" ACPI_WMI_EVENT");
469 }
470 pr_cont("\n");
471
472}
473
474static void wmi_notify_debug(u32 value, void *context)
475{
476 struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
477 union acpi_object *obj;
478 acpi_status status;
479
480 status = wmi_get_event_data(value, &response);
481 if (status != AE_OK) {
482 pr_info("bad event status 0x%x\n", status);
483 return;
484 }
485
486 obj = (union acpi_object *)response.pointer;
487
488 if (!obj)
489 return;
490
491 pr_info("DEBUG Event ");
492 switch(obj->type) {
493 case ACPI_TYPE_BUFFER:
494 pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
495 break;
496 case ACPI_TYPE_STRING:
497 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
498 break;
499 case ACPI_TYPE_INTEGER:
500 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
501 break;
502 case ACPI_TYPE_PACKAGE:
503 pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
504 break;
505 default:
506 pr_cont("object type 0x%X\n", obj->type);
507 }
508 kfree(obj);
509}
510
511/**
512 * wmi_install_notify_handler - Register handler for WMI events
513 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
514 * @handler: Function to handle notifications
515 * @data: Data to be returned to handler when event is fired
516 *
517 * Register a handler for events sent to the ACPI-WMI mapper device.
518 */
519acpi_status wmi_install_notify_handler(const char *guid,
520wmi_notify_handler handler, void *data)
521{
522 struct wmi_block *block;
523 acpi_status status = AE_NOT_EXIST;
524 guid_t guid_input;
525
526 if (!guid || !handler)
527 return AE_BAD_PARAMETER;
528
529 if (guid_parse(guid, &guid_input))
530 return AE_BAD_PARAMETER;
531
532 list_for_each_entry(block, &wmi_block_list, list) {
533 acpi_status wmi_status;
534
535 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
536 if (block->handler &&
537 block->handler != wmi_notify_debug)
538 return AE_ALREADY_ACQUIRED;
539
540 block->handler = handler;
541 block->handler_data = data;
542
543 wmi_status = wmi_method_enable(block, 1);
544 if ((wmi_status != AE_OK) ||
545 ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
546 status = wmi_status;
547 }
548 }
549
550 return status;
551}
552EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
553
554/**
555 * wmi_uninstall_notify_handler - Unregister handler for WMI events
556 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
557 *
558 * Unregister handler for events sent to the ACPI-WMI mapper device.
559 */
560acpi_status wmi_remove_notify_handler(const char *guid)
561{
562 struct wmi_block *block;
563 acpi_status status = AE_NOT_EXIST;
564 guid_t guid_input;
565
566 if (!guid)
567 return AE_BAD_PARAMETER;
568
569 if (guid_parse(guid, &guid_input))
570 return AE_BAD_PARAMETER;
571
572 list_for_each_entry(block, &wmi_block_list, list) {
573 acpi_status wmi_status;
574
575 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
576 if (!block->handler ||
577 block->handler == wmi_notify_debug)
578 return AE_NULL_ENTRY;
579
580 if (debug_event) {
581 block->handler = wmi_notify_debug;
582 status = AE_OK;
583 } else {
584 wmi_status = wmi_method_enable(block, 0);
585 block->handler = NULL;
586 block->handler_data = NULL;
587 if ((wmi_status != AE_OK) ||
588 ((wmi_status == AE_OK) &&
589 (status == AE_NOT_EXIST)))
590 status = wmi_status;
591 }
592 }
593 }
594
595 return status;
596}
597EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
598
599/**
600 * wmi_get_event_data - Get WMI data associated with an event
601 *
602 * @event: Event to find
603 * @out: Buffer to hold event data. out->pointer should be freed with kfree()
604 *
605 * Returns extra data associated with an event in WMI.
606 */
607acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
608{
609 struct acpi_object_list input;
610 union acpi_object params[1];
611 struct guid_block *gblock;
612 struct wmi_block *wblock;
613
614 input.count = 1;
615 input.pointer = params;
616 params[0].type = ACPI_TYPE_INTEGER;
617 params[0].integer.value = event;
618
619 list_for_each_entry(wblock, &wmi_block_list, list) {
620 gblock = &wblock->gblock;
621
622 if ((gblock->flags & ACPI_WMI_EVENT) &&
623 (gblock->notify_id == event))
624 return acpi_evaluate_object(wblock->acpi_device->handle,
625 "_WED", &input, out);
626 }
627
628 return AE_NOT_FOUND;
629}
630EXPORT_SYMBOL_GPL(wmi_get_event_data);
631
632/**
633 * wmi_has_guid - Check if a GUID is available
634 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
635 *
636 * Check if a given GUID is defined by _WDG
637 */
638bool wmi_has_guid(const char *guid_string)
639{
640 return find_guid(guid_string, NULL);
641}
642EXPORT_SYMBOL_GPL(wmi_has_guid);
643
644/**
645 * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID
646 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
647 *
648 * Find the _UID of ACPI device associated with this WMI GUID.
649 *
650 * Return: The ACPI _UID field value or NULL if the WMI GUID was not found
651 */
652char *wmi_get_acpi_device_uid(const char *guid_string)
653{
654 struct wmi_block *wblock = NULL;
655
656 if (!find_guid(guid_string, &wblock))
657 return NULL;
658
659 return acpi_device_uid(wblock->acpi_device);
660}
661EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
662
663static struct wmi_block *dev_to_wblock(struct device *dev)
664{
665 return container_of(dev, struct wmi_block, dev.dev);
666}
667
668static struct wmi_device *dev_to_wdev(struct device *dev)
669{
670 return container_of(dev, struct wmi_device, dev);
671}
672
673/*
674 * sysfs interface
675 */
676static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
677 char *buf)
678{
679 struct wmi_block *wblock = dev_to_wblock(dev);
680
681 return sprintf(buf, "wmi:%pUL\n", wblock->gblock.guid);
682}
683static DEVICE_ATTR_RO(modalias);
684
685static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
686 char *buf)
687{
688 struct wmi_block *wblock = dev_to_wblock(dev);
689
690 return sprintf(buf, "%pUL\n", wblock->gblock.guid);
691}
692static DEVICE_ATTR_RO(guid);
693
694static ssize_t instance_count_show(struct device *dev,
695 struct device_attribute *attr, char *buf)
696{
697 struct wmi_block *wblock = dev_to_wblock(dev);
698
699 return sprintf(buf, "%d\n", (int)wblock->gblock.instance_count);
700}
701static DEVICE_ATTR_RO(instance_count);
702
703static ssize_t expensive_show(struct device *dev,
704 struct device_attribute *attr, char *buf)
705{
706 struct wmi_block *wblock = dev_to_wblock(dev);
707
708 return sprintf(buf, "%d\n",
709 (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
710}
711static DEVICE_ATTR_RO(expensive);
712
713static struct attribute *wmi_attrs[] = {
714 &dev_attr_modalias.attr,
715 &dev_attr_guid.attr,
716 &dev_attr_instance_count.attr,
717 &dev_attr_expensive.attr,
718 NULL,
719};
720ATTRIBUTE_GROUPS(wmi);
721
722static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
723 char *buf)
724{
725 struct wmi_block *wblock = dev_to_wblock(dev);
726
727 return sprintf(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
728}
729static DEVICE_ATTR_RO(notify_id);
730
731static struct attribute *wmi_event_attrs[] = {
732 &dev_attr_notify_id.attr,
733 NULL,
734};
735ATTRIBUTE_GROUPS(wmi_event);
736
737static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
738 char *buf)
739{
740 struct wmi_block *wblock = dev_to_wblock(dev);
741
742 return sprintf(buf, "%c%c\n", wblock->gblock.object_id[0],
743 wblock->gblock.object_id[1]);
744}
745static DEVICE_ATTR_RO(object_id);
746
747static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
748 char *buf)
749{
750 struct wmi_device *wdev = dev_to_wdev(dev);
751
752 return sprintf(buf, "%d\n", (int)wdev->setable);
753}
754static DEVICE_ATTR_RO(setable);
755
756static struct attribute *wmi_data_attrs[] = {
757 &dev_attr_object_id.attr,
758 &dev_attr_setable.attr,
759 NULL,
760};
761ATTRIBUTE_GROUPS(wmi_data);
762
763static struct attribute *wmi_method_attrs[] = {
764 &dev_attr_object_id.attr,
765 NULL,
766};
767ATTRIBUTE_GROUPS(wmi_method);
768
769static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
770{
771 struct wmi_block *wblock = dev_to_wblock(dev);
772
773 if (add_uevent_var(env, "MODALIAS=wmi:%pUL", wblock->gblock.guid))
774 return -ENOMEM;
775
776 if (add_uevent_var(env, "WMI_GUID=%pUL", wblock->gblock.guid))
777 return -ENOMEM;
778
779 return 0;
780}
781
782static void wmi_dev_release(struct device *dev)
783{
784 struct wmi_block *wblock = dev_to_wblock(dev);
785
786 kfree(wblock);
787}
788
789static int wmi_dev_match(struct device *dev, struct device_driver *driver)
790{
791 struct wmi_driver *wmi_driver =
792 container_of(driver, struct wmi_driver, driver);
793 struct wmi_block *wblock = dev_to_wblock(dev);
794 const struct wmi_device_id *id = wmi_driver->id_table;
795
796 if (id == NULL)
797 return 0;
798
799 while (*id->guid_string) {
800 guid_t driver_guid;
801
802 if (WARN_ON(guid_parse(id->guid_string, &driver_guid)))
803 continue;
804 if (!memcmp(&driver_guid, wblock->gblock.guid, 16))
805 return 1;
806
807 id++;
808 }
809
810 return 0;
811}
812static int wmi_char_open(struct inode *inode, struct file *filp)
813{
814 const char *driver_name = filp->f_path.dentry->d_iname;
815 struct wmi_block *wblock = NULL;
816 struct wmi_block *next = NULL;
817
818 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
819 if (!wblock->dev.dev.driver)
820 continue;
821 if (strcmp(driver_name, wblock->dev.dev.driver->name) == 0) {
822 filp->private_data = wblock;
823 break;
824 }
825 }
826
827 if (!filp->private_data)
828 return -ENODEV;
829
830 return nonseekable_open(inode, filp);
831}
832
833static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
834 size_t length, loff_t *offset)
835{
836 struct wmi_block *wblock = filp->private_data;
837
838 return simple_read_from_buffer(buffer, length, offset,
839 &wblock->req_buf_size,
840 sizeof(wblock->req_buf_size));
841}
842
843static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
844{
845 struct wmi_ioctl_buffer __user *input =
846 (struct wmi_ioctl_buffer __user *) arg;
847 struct wmi_block *wblock = filp->private_data;
848 struct wmi_ioctl_buffer *buf = NULL;
849 struct wmi_driver *wdriver = NULL;
850 int ret;
851
852 if (_IOC_TYPE(cmd) != WMI_IOC)
853 return -ENOTTY;
854
855 /* make sure we're not calling a higher instance than exists*/
856 if (_IOC_NR(cmd) >= wblock->gblock.instance_count)
857 return -EINVAL;
858
859 mutex_lock(&wblock->char_mutex);
860 buf = wblock->handler_data;
861 if (get_user(buf->length, &input->length)) {
862 dev_dbg(&wblock->dev.dev, "Read length from user failed\n");
863 ret = -EFAULT;
864 goto out_ioctl;
865 }
866 /* if it's too small, abort */
867 if (buf->length < wblock->req_buf_size) {
868 dev_err(&wblock->dev.dev,
869 "Buffer %lld too small, need at least %lld\n",
870 buf->length, wblock->req_buf_size);
871 ret = -EINVAL;
872 goto out_ioctl;
873 }
874 /* if it's too big, warn, driver will only use what is needed */
875 if (buf->length > wblock->req_buf_size)
876 dev_warn(&wblock->dev.dev,
877 "Buffer %lld is bigger than required %lld\n",
878 buf->length, wblock->req_buf_size);
879
880 /* copy the structure from userspace */
881 if (copy_from_user(buf, input, wblock->req_buf_size)) {
882 dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n",
883 wblock->req_buf_size);
884 ret = -EFAULT;
885 goto out_ioctl;
886 }
887
888 /* let the driver do any filtering and do the call */
889 wdriver = container_of(wblock->dev.dev.driver,
890 struct wmi_driver, driver);
891 if (!try_module_get(wdriver->driver.owner)) {
892 ret = -EBUSY;
893 goto out_ioctl;
894 }
895 ret = wdriver->filter_callback(&wblock->dev, cmd, buf);
896 module_put(wdriver->driver.owner);
897 if (ret)
898 goto out_ioctl;
899
900 /* return the result (only up to our internal buffer size) */
901 if (copy_to_user(input, buf, wblock->req_buf_size)) {
902 dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n",
903 wblock->req_buf_size);
904 ret = -EFAULT;
905 }
906
907out_ioctl:
908 mutex_unlock(&wblock->char_mutex);
909 return ret;
910}
911
912static const struct file_operations wmi_fops = {
913 .owner = THIS_MODULE,
914 .read = wmi_char_read,
915 .open = wmi_char_open,
916 .unlocked_ioctl = wmi_ioctl,
917 .compat_ioctl = compat_ptr_ioctl,
918};
919
920static int wmi_dev_probe(struct device *dev)
921{
922 struct wmi_block *wblock = dev_to_wblock(dev);
923 struct wmi_driver *wdriver =
924 container_of(dev->driver, struct wmi_driver, driver);
925 int ret = 0;
926 char *buf;
927
928 if (ACPI_FAILURE(wmi_method_enable(wblock, 1)))
929 dev_warn(dev, "failed to enable device -- probing anyway\n");
930
931 if (wdriver->probe) {
932 ret = wdriver->probe(dev_to_wdev(dev),
933 find_guid_context(wblock, wdriver));
934 if (ret != 0)
935 goto probe_failure;
936 }
937
938 /* driver wants a character device made */
939 if (wdriver->filter_callback) {
940 /* check that required buffer size declared by driver or MOF */
941 if (!wblock->req_buf_size) {
942 dev_err(&wblock->dev.dev,
943 "Required buffer size not set\n");
944 ret = -EINVAL;
945 goto probe_failure;
946 }
947
948 wblock->handler_data = kmalloc(wblock->req_buf_size,
949 GFP_KERNEL);
950 if (!wblock->handler_data) {
951 ret = -ENOMEM;
952 goto probe_failure;
953 }
954
955 buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name);
956 if (!buf) {
957 ret = -ENOMEM;
958 goto probe_string_failure;
959 }
960 wblock->char_dev.minor = MISC_DYNAMIC_MINOR;
961 wblock->char_dev.name = buf;
962 wblock->char_dev.fops = &wmi_fops;
963 wblock->char_dev.mode = 0444;
964 ret = misc_register(&wblock->char_dev);
965 if (ret) {
966 dev_warn(dev, "failed to register char dev: %d\n", ret);
967 ret = -ENOMEM;
968 goto probe_misc_failure;
969 }
970 }
971
972 return 0;
973
974probe_misc_failure:
975 kfree(buf);
976probe_string_failure:
977 kfree(wblock->handler_data);
978probe_failure:
979 if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
980 dev_warn(dev, "failed to disable device\n");
981 return ret;
982}
983
984static int wmi_dev_remove(struct device *dev)
985{
986 struct wmi_block *wblock = dev_to_wblock(dev);
987 struct wmi_driver *wdriver =
988 container_of(dev->driver, struct wmi_driver, driver);
989 int ret = 0;
990
991 if (wdriver->filter_callback) {
992 misc_deregister(&wblock->char_dev);
993 kfree(wblock->char_dev.name);
994 kfree(wblock->handler_data);
995 }
996
997 if (wdriver->remove)
998 ret = wdriver->remove(dev_to_wdev(dev));
999
1000 if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
1001 dev_warn(dev, "failed to disable device\n");
1002
1003 return ret;
1004}
1005
1006static struct class wmi_bus_class = {
1007 .name = "wmi_bus",
1008};
1009
1010static struct bus_type wmi_bus_type = {
1011 .name = "wmi",
1012 .dev_groups = wmi_groups,
1013 .match = wmi_dev_match,
1014 .uevent = wmi_dev_uevent,
1015 .probe = wmi_dev_probe,
1016 .remove = wmi_dev_remove,
1017};
1018
1019static const struct device_type wmi_type_event = {
1020 .name = "event",
1021 .groups = wmi_event_groups,
1022 .release = wmi_dev_release,
1023};
1024
1025static const struct device_type wmi_type_method = {
1026 .name = "method",
1027 .groups = wmi_method_groups,
1028 .release = wmi_dev_release,
1029};
1030
1031static const struct device_type wmi_type_data = {
1032 .name = "data",
1033 .groups = wmi_data_groups,
1034 .release = wmi_dev_release,
1035};
1036
1037static int wmi_create_device(struct device *wmi_bus_dev,
1038 const struct guid_block *gblock,
1039 struct wmi_block *wblock,
1040 struct acpi_device *device)
1041{
1042 struct acpi_device_info *info;
1043 char method[5];
1044 int result;
1045
1046 if (gblock->flags & ACPI_WMI_EVENT) {
1047 wblock->dev.dev.type = &wmi_type_event;
1048 goto out_init;
1049 }
1050
1051 if (gblock->flags & ACPI_WMI_METHOD) {
1052 wblock->dev.dev.type = &wmi_type_method;
1053 mutex_init(&wblock->char_mutex);
1054 goto out_init;
1055 }
1056
1057 /*
1058 * Data Block Query Control Method (WQxx by convention) is
1059 * required per the WMI documentation. If it is not present,
1060 * we ignore this data block.
1061 */
1062 strcpy(method, "WQ");
1063 strncat(method, wblock->gblock.object_id, 2);
1064 result = get_subobj_info(device->handle, method, &info);
1065
1066 if (result) {
1067 dev_warn(wmi_bus_dev,
1068 "%s data block query control method not found\n",
1069 method);
1070 return result;
1071 }
1072
1073 wblock->dev.dev.type = &wmi_type_data;
1074
1075 /*
1076 * The Microsoft documentation specifically states:
1077 *
1078 * Data blocks registered with only a single instance
1079 * can ignore the parameter.
1080 *
1081 * ACPICA will get mad at us if we call the method with the wrong number
1082 * of arguments, so check what our method expects. (On some Dell
1083 * laptops, WQxx may not be a method at all.)
1084 */
1085 if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1086 wblock->read_takes_no_args = true;
1087
1088 kfree(info);
1089
1090 strcpy(method, "WS");
1091 strncat(method, wblock->gblock.object_id, 2);
1092 result = get_subobj_info(device->handle, method, NULL);
1093
1094 if (result == 0)
1095 wblock->dev.setable = true;
1096
1097 out_init:
1098 wblock->dev.dev.bus = &wmi_bus_type;
1099 wblock->dev.dev.parent = wmi_bus_dev;
1100
1101 dev_set_name(&wblock->dev.dev, "%pUL", gblock->guid);
1102
1103 device_initialize(&wblock->dev.dev);
1104
1105 return 0;
1106}
1107
1108static void wmi_free_devices(struct acpi_device *device)
1109{
1110 struct wmi_block *wblock, *next;
1111
1112 /* Delete devices for all the GUIDs */
1113 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1114 if (wblock->acpi_device == device) {
1115 list_del(&wblock->list);
1116 device_unregister(&wblock->dev.dev);
1117 }
1118 }
1119}
1120
1121static bool guid_already_parsed(struct acpi_device *device, const u8 *guid)
1122{
1123 struct wmi_block *wblock;
1124
1125 list_for_each_entry(wblock, &wmi_block_list, list) {
1126 if (memcmp(wblock->gblock.guid, guid, 16) == 0) {
1127 /*
1128 * Because we historically didn't track the relationship
1129 * between GUIDs and ACPI nodes, we don't know whether
1130 * we need to suppress GUIDs that are unique on a
1131 * given node but duplicated across nodes.
1132 */
1133 dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
1134 guid, dev_name(&wblock->acpi_device->dev));
1135 return true;
1136 }
1137 }
1138
1139 return false;
1140}
1141
1142/*
1143 * Parse the _WDG method for the GUID data blocks
1144 */
1145static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
1146{
1147 struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1148 const struct guid_block *gblock;
1149 struct wmi_block *wblock, *next;
1150 union acpi_object *obj;
1151 acpi_status status;
1152 int retval = 0;
1153 u32 i, total;
1154
1155 status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1156 if (ACPI_FAILURE(status))
1157 return -ENXIO;
1158
1159 obj = (union acpi_object *) out.pointer;
1160 if (!obj)
1161 return -ENXIO;
1162
1163 if (obj->type != ACPI_TYPE_BUFFER) {
1164 retval = -ENXIO;
1165 goto out_free_pointer;
1166 }
1167
1168 gblock = (const struct guid_block *)obj->buffer.pointer;
1169 total = obj->buffer.length / sizeof(struct guid_block);
1170
1171 for (i = 0; i < total; i++) {
1172 if (debug_dump_wdg)
1173 wmi_dump_wdg(&gblock[i]);
1174
1175 /*
1176 * Some WMI devices, like those for nVidia hooks, have a
1177 * duplicate GUID. It's not clear what we should do in this
1178 * case yet, so for now, we'll just ignore the duplicate
1179 * for device creation.
1180 */
1181 if (guid_already_parsed(device, gblock[i].guid))
1182 continue;
1183
1184 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
1185 if (!wblock) {
1186 retval = -ENOMEM;
1187 break;
1188 }
1189
1190 wblock->acpi_device = device;
1191 wblock->gblock = gblock[i];
1192
1193 retval = wmi_create_device(wmi_bus_dev, &gblock[i], wblock, device);
1194 if (retval) {
1195 kfree(wblock);
1196 continue;
1197 }
1198
1199 list_add_tail(&wblock->list, &wmi_block_list);
1200
1201 if (debug_event) {
1202 wblock->handler = wmi_notify_debug;
1203 wmi_method_enable(wblock, 1);
1204 }
1205 }
1206
1207 /*
1208 * Now that all of the devices are created, add them to the
1209 * device tree and probe subdrivers.
1210 */
1211 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1212 if (wblock->acpi_device != device)
1213 continue;
1214
1215 retval = device_add(&wblock->dev.dev);
1216 if (retval) {
1217 dev_err(wmi_bus_dev, "failed to register %pUL\n",
1218 wblock->gblock.guid);
1219 if (debug_event)
1220 wmi_method_enable(wblock, 0);
1221 list_del(&wblock->list);
1222 put_device(&wblock->dev.dev);
1223 }
1224 }
1225
1226out_free_pointer:
1227 kfree(out.pointer);
1228 return retval;
1229}
1230
1231/*
1232 * WMI can have EmbeddedControl access regions. In which case, we just want to
1233 * hand these off to the EC driver.
1234 */
1235static acpi_status
1236acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1237 u32 bits, u64 *value,
1238 void *handler_context, void *region_context)
1239{
1240 int result = 0, i = 0;
1241 u8 temp = 0;
1242
1243 if ((address > 0xFF) || !value)
1244 return AE_BAD_PARAMETER;
1245
1246 if (function != ACPI_READ && function != ACPI_WRITE)
1247 return AE_BAD_PARAMETER;
1248
1249 if (bits != 8)
1250 return AE_BAD_PARAMETER;
1251
1252 if (function == ACPI_READ) {
1253 result = ec_read(address, &temp);
1254 (*value) |= ((u64)temp) << i;
1255 } else {
1256 temp = 0xff & ((*value) >> i);
1257 result = ec_write(address, temp);
1258 }
1259
1260 switch (result) {
1261 case -EINVAL:
1262 return AE_BAD_PARAMETER;
1263 break;
1264 case -ENODEV:
1265 return AE_NOT_FOUND;
1266 break;
1267 case -ETIME:
1268 return AE_TIME;
1269 break;
1270 default:
1271 return AE_OK;
1272 }
1273}
1274
1275static void acpi_wmi_notify_handler(acpi_handle handle, u32 event,
1276 void *context)
1277{
1278 struct guid_block *block;
1279 struct wmi_block *wblock;
1280 bool found_it = false;
1281
1282 list_for_each_entry(wblock, &wmi_block_list, list) {
1283 block = &wblock->gblock;
1284
1285 if (wblock->acpi_device->handle == handle &&
1286 (block->flags & ACPI_WMI_EVENT) &&
1287 (block->notify_id == event))
1288 {
1289 found_it = true;
1290 break;
1291 }
1292 }
1293
1294 if (!found_it)
1295 return;
1296
1297 /* If a driver is bound, then notify the driver. */
1298 if (wblock->dev.dev.driver) {
1299 struct wmi_driver *driver;
1300 struct acpi_object_list input;
1301 union acpi_object params[1];
1302 struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL };
1303 acpi_status status;
1304
1305 driver = container_of(wblock->dev.dev.driver,
1306 struct wmi_driver, driver);
1307
1308 input.count = 1;
1309 input.pointer = params;
1310 params[0].type = ACPI_TYPE_INTEGER;
1311 params[0].integer.value = event;
1312
1313 status = acpi_evaluate_object(wblock->acpi_device->handle,
1314 "_WED", &input, &evdata);
1315 if (ACPI_FAILURE(status)) {
1316 dev_warn(&wblock->dev.dev,
1317 "failed to get event data\n");
1318 return;
1319 }
1320
1321 if (driver->notify)
1322 driver->notify(&wblock->dev,
1323 (union acpi_object *)evdata.pointer);
1324
1325 kfree(evdata.pointer);
1326 } else if (wblock->handler) {
1327 /* Legacy handler */
1328 wblock->handler(event, wblock->handler_data);
1329 }
1330
1331 if (debug_event)
1332 pr_info("DEBUG Event GUID: %pUL\n", wblock->gblock.guid);
1333
1334 acpi_bus_generate_netlink_event(
1335 wblock->acpi_device->pnp.device_class,
1336 dev_name(&wblock->dev.dev),
1337 event, 0);
1338
1339}
1340
1341static int acpi_wmi_remove(struct platform_device *device)
1342{
1343 struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev);
1344
1345 acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1346 acpi_wmi_notify_handler);
1347 acpi_remove_address_space_handler(acpi_device->handle,
1348 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
1349 wmi_free_devices(acpi_device);
1350 device_destroy(&wmi_bus_class, MKDEV(0, 0));
1351
1352 return 0;
1353}
1354
1355static int acpi_wmi_probe(struct platform_device *device)
1356{
1357 struct acpi_device *acpi_device;
1358 struct device *wmi_bus_dev;
1359 acpi_status status;
1360 int error;
1361
1362 acpi_device = ACPI_COMPANION(&device->dev);
1363 if (!acpi_device) {
1364 dev_err(&device->dev, "ACPI companion is missing\n");
1365 return -ENODEV;
1366 }
1367
1368 status = acpi_install_address_space_handler(acpi_device->handle,
1369 ACPI_ADR_SPACE_EC,
1370 &acpi_wmi_ec_space_handler,
1371 NULL, NULL);
1372 if (ACPI_FAILURE(status)) {
1373 dev_err(&device->dev, "Error installing EC region handler\n");
1374 return -ENODEV;
1375 }
1376
1377 status = acpi_install_notify_handler(acpi_device->handle,
1378 ACPI_DEVICE_NOTIFY,
1379 acpi_wmi_notify_handler,
1380 NULL);
1381 if (ACPI_FAILURE(status)) {
1382 dev_err(&device->dev, "Error installing notify handler\n");
1383 error = -ENODEV;
1384 goto err_remove_ec_handler;
1385 }
1386
1387 wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0),
1388 NULL, "wmi_bus-%s", dev_name(&device->dev));
1389 if (IS_ERR(wmi_bus_dev)) {
1390 error = PTR_ERR(wmi_bus_dev);
1391 goto err_remove_notify_handler;
1392 }
1393 dev_set_drvdata(&device->dev, wmi_bus_dev);
1394
1395 error = parse_wdg(wmi_bus_dev, acpi_device);
1396 if (error) {
1397 pr_err("Failed to parse WDG method\n");
1398 goto err_remove_busdev;
1399 }
1400
1401 return 0;
1402
1403err_remove_busdev:
1404 device_destroy(&wmi_bus_class, MKDEV(0, 0));
1405
1406err_remove_notify_handler:
1407 acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1408 acpi_wmi_notify_handler);
1409
1410err_remove_ec_handler:
1411 acpi_remove_address_space_handler(acpi_device->handle,
1412 ACPI_ADR_SPACE_EC,
1413 &acpi_wmi_ec_space_handler);
1414
1415 return error;
1416}
1417
1418int __must_check __wmi_driver_register(struct wmi_driver *driver,
1419 struct module *owner)
1420{
1421 driver->driver.owner = owner;
1422 driver->driver.bus = &wmi_bus_type;
1423
1424 return driver_register(&driver->driver);
1425}
1426EXPORT_SYMBOL(__wmi_driver_register);
1427
1428void wmi_driver_unregister(struct wmi_driver *driver)
1429{
1430 driver_unregister(&driver->driver);
1431}
1432EXPORT_SYMBOL(wmi_driver_unregister);
1433
1434static int __init acpi_wmi_init(void)
1435{
1436 int error;
1437
1438 if (acpi_disabled)
1439 return -ENODEV;
1440
1441 error = class_register(&wmi_bus_class);
1442 if (error)
1443 return error;
1444
1445 error = bus_register(&wmi_bus_type);
1446 if (error)
1447 goto err_unreg_class;
1448
1449 error = platform_driver_register(&acpi_wmi_driver);
1450 if (error) {
1451 pr_err("Error loading mapper\n");
1452 goto err_unreg_bus;
1453 }
1454
1455 return 0;
1456
1457err_unreg_bus:
1458 bus_unregister(&wmi_bus_type);
1459
1460err_unreg_class:
1461 class_unregister(&wmi_bus_class);
1462
1463 return error;
1464}
1465
1466static void __exit acpi_wmi_exit(void)
1467{
1468 platform_driver_unregister(&acpi_wmi_driver);
1469 bus_unregister(&wmi_bus_type);
1470 class_unregister(&wmi_bus_class);
1471}
1472
1473subsys_initcall_sync(acpi_wmi_init);
1474module_exit(acpi_wmi_exit);
1/*
2 * ACPI-WMI mapping driver
3 *
4 * Copyright (C) 2007-2008 Carlos Corbacho <carlos@strangeworlds.co.uk>
5 *
6 * GUID parsing code from ldm.c is:
7 * Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
8 * Copyright (c) 2001-2007 Anton Altaparmakov
9 * Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
10 *
11 * 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);