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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/bits.h>
21#include <linux/build_bug.h>
22#include <linux/device.h>
23#include <linux/init.h>
24#include <linux/kernel.h>
25#include <linux/list.h>
26#include <linux/module.h>
27#include <linux/platform_device.h>
28#include <linux/rwsem.h>
29#include <linux/slab.h>
30#include <linux/sysfs.h>
31#include <linux/types.h>
32#include <linux/uuid.h>
33#include <linux/wmi.h>
34#include <linux/fs.h>
35
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 guid_t guid;
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} __packed;
54static_assert(sizeof(typeof_member(struct guid_block, guid)) == 16);
55static_assert(sizeof(struct guid_block) == 20);
56static_assert(__alignof__(struct guid_block) == 1);
57
58enum { /* wmi_block flags */
59 WMI_READ_TAKES_NO_ARGS,
60};
61
62struct wmi_block {
63 struct wmi_device dev;
64 struct list_head list;
65 struct guid_block gblock;
66 struct acpi_device *acpi_device;
67 struct rw_semaphore notify_lock; /* Protects notify callback add/remove */
68 wmi_notify_handler handler;
69 void *handler_data;
70 bool driver_ready;
71 unsigned long flags;
72};
73
74
75/*
76 * If the GUID data block is marked as expensive, we must enable and
77 * explicitily disable data collection.
78 */
79#define ACPI_WMI_EXPENSIVE BIT(0)
80#define ACPI_WMI_METHOD BIT(1) /* GUID is a method */
81#define ACPI_WMI_STRING BIT(2) /* GUID takes & returns a string */
82#define ACPI_WMI_EVENT BIT(3) /* GUID is an event */
83
84static const struct acpi_device_id wmi_device_ids[] = {
85 {"PNP0C14", 0},
86 {"pnp0c14", 0},
87 { }
88};
89MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
90
91/* allow duplicate GUIDs as these device drivers use struct wmi_driver */
92static const char * const allow_duplicates[] = {
93 "05901221-D566-11D1-B2F0-00A0C9062910", /* wmi-bmof */
94 "8A42EA14-4F2A-FD45-6422-0087F7A7E608", /* dell-wmi-ddv */
95 "44FADEB1-B204-40F2-8581-394BBDC1B651", /* intel-wmi-sbl-fw-update */
96 "86CCFD48-205E-4A77-9C48-2021CBEDE341", /* intel-wmi-thunderbolt */
97 "F1DDEE52-063C-4784-A11E-8A06684B9B01", /* dell-smm-hwmon */
98 NULL
99};
100
101#define dev_to_wblock(__dev) container_of_const(__dev, struct wmi_block, dev.dev)
102#define dev_to_wdev(__dev) container_of_const(__dev, struct wmi_device, dev)
103
104/*
105 * GUID parsing functions
106 */
107
108static bool guid_parse_and_compare(const char *string, const guid_t *guid)
109{
110 guid_t guid_input;
111
112 if (guid_parse(string, &guid_input))
113 return false;
114
115 return guid_equal(&guid_input, guid);
116}
117
118static const void *find_guid_context(struct wmi_block *wblock,
119 struct wmi_driver *wdriver)
120{
121 const struct wmi_device_id *id;
122
123 id = wdriver->id_table;
124 if (!id)
125 return NULL;
126
127 while (*id->guid_string) {
128 if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid))
129 return id->context;
130 id++;
131 }
132 return NULL;
133}
134
135static int get_subobj_info(acpi_handle handle, const char *pathname,
136 struct acpi_device_info **info)
137{
138 acpi_handle subobj_handle;
139 acpi_status status;
140
141 status = acpi_get_handle(handle, pathname, &subobj_handle);
142 if (status == AE_NOT_FOUND)
143 return -ENOENT;
144
145 if (ACPI_FAILURE(status))
146 return -EIO;
147
148 status = acpi_get_object_info(subobj_handle, info);
149 if (ACPI_FAILURE(status))
150 return -EIO;
151
152 return 0;
153}
154
155static acpi_status wmi_method_enable(struct wmi_block *wblock, bool enable)
156{
157 struct guid_block *block;
158 char method[5];
159 acpi_status status;
160 acpi_handle handle;
161
162 block = &wblock->gblock;
163 handle = wblock->acpi_device->handle;
164
165 snprintf(method, 5, "WE%02X", block->notify_id);
166 status = acpi_execute_simple_method(handle, method, enable);
167 if (status == AE_NOT_FOUND)
168 return AE_OK;
169
170 return status;
171}
172
173#define WMI_ACPI_METHOD_NAME_SIZE 5
174
175static inline void get_acpi_method_name(const struct wmi_block *wblock,
176 const char method,
177 char buffer[static WMI_ACPI_METHOD_NAME_SIZE])
178{
179 static_assert(ARRAY_SIZE(wblock->gblock.object_id) == 2);
180 static_assert(WMI_ACPI_METHOD_NAME_SIZE >= 5);
181
182 buffer[0] = 'W';
183 buffer[1] = method;
184 buffer[2] = wblock->gblock.object_id[0];
185 buffer[3] = wblock->gblock.object_id[1];
186 buffer[4] = '\0';
187}
188
189static inline acpi_object_type get_param_acpi_type(const struct wmi_block *wblock)
190{
191 if (wblock->gblock.flags & ACPI_WMI_STRING)
192 return ACPI_TYPE_STRING;
193 else
194 return ACPI_TYPE_BUFFER;
195}
196
197static acpi_status get_event_data(const struct wmi_block *wblock, struct acpi_buffer *out)
198{
199 union acpi_object param = {
200 .integer = {
201 .type = ACPI_TYPE_INTEGER,
202 .value = wblock->gblock.notify_id,
203 }
204 };
205 struct acpi_object_list input = {
206 .count = 1,
207 .pointer = ¶m,
208 };
209
210 return acpi_evaluate_object(wblock->acpi_device->handle, "_WED", &input, out);
211}
212
213static int wmidev_match_guid(struct device *dev, const void *data)
214{
215 struct wmi_block *wblock = dev_to_wblock(dev);
216 const guid_t *guid = data;
217
218 if (guid_equal(guid, &wblock->gblock.guid))
219 return 1;
220
221 return 0;
222}
223
224static int wmidev_match_notify_id(struct device *dev, const void *data)
225{
226 struct wmi_block *wblock = dev_to_wblock(dev);
227 const u32 *notify_id = data;
228
229 if (wblock->gblock.flags & ACPI_WMI_EVENT && wblock->gblock.notify_id == *notify_id)
230 return 1;
231
232 return 0;
233}
234
235static struct bus_type wmi_bus_type;
236
237static struct wmi_device *wmi_find_device_by_guid(const char *guid_string)
238{
239 struct device *dev;
240 guid_t guid;
241 int ret;
242
243 ret = guid_parse(guid_string, &guid);
244 if (ret < 0)
245 return ERR_PTR(ret);
246
247 dev = bus_find_device(&wmi_bus_type, NULL, &guid, wmidev_match_guid);
248 if (!dev)
249 return ERR_PTR(-ENODEV);
250
251 return dev_to_wdev(dev);
252}
253
254static struct wmi_device *wmi_find_event_by_notify_id(const u32 notify_id)
255{
256 struct device *dev;
257
258 dev = bus_find_device(&wmi_bus_type, NULL, ¬ify_id, wmidev_match_notify_id);
259 if (!dev)
260 return ERR_PTR(-ENODEV);
261
262 return to_wmi_device(dev);
263}
264
265static void wmi_device_put(struct wmi_device *wdev)
266{
267 put_device(&wdev->dev);
268}
269
270/*
271 * Exported WMI functions
272 */
273
274/**
275 * wmi_instance_count - Get number of WMI object instances
276 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
277 *
278 * Get the number of WMI object instances.
279 *
280 * Returns: Number of WMI object instances or negative error code.
281 */
282int wmi_instance_count(const char *guid_string)
283{
284 struct wmi_device *wdev;
285 int ret;
286
287 wdev = wmi_find_device_by_guid(guid_string);
288 if (IS_ERR(wdev))
289 return PTR_ERR(wdev);
290
291 ret = wmidev_instance_count(wdev);
292 wmi_device_put(wdev);
293
294 return ret;
295}
296EXPORT_SYMBOL_GPL(wmi_instance_count);
297
298/**
299 * wmidev_instance_count - Get number of WMI object instances
300 * @wdev: A wmi bus device from a driver
301 *
302 * Get the number of WMI object instances.
303 *
304 * Returns: Number of WMI object instances.
305 */
306u8 wmidev_instance_count(struct wmi_device *wdev)
307{
308 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
309
310 return wblock->gblock.instance_count;
311}
312EXPORT_SYMBOL_GPL(wmidev_instance_count);
313
314/**
315 * wmi_evaluate_method - Evaluate a WMI method (deprecated)
316 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
317 * @instance: Instance index
318 * @method_id: Method ID to call
319 * @in: Buffer containing input for the method call
320 * @out: Empty buffer to return the method results
321 *
322 * Call an ACPI-WMI method, the caller must free @out.
323 *
324 * Return: acpi_status signaling success or error.
325 */
326acpi_status wmi_evaluate_method(const char *guid_string, u8 instance, u32 method_id,
327 const struct acpi_buffer *in, struct acpi_buffer *out)
328{
329 struct wmi_device *wdev;
330 acpi_status status;
331
332 wdev = wmi_find_device_by_guid(guid_string);
333 if (IS_ERR(wdev))
334 return AE_ERROR;
335
336 status = wmidev_evaluate_method(wdev, instance, method_id, in, out);
337
338 wmi_device_put(wdev);
339
340 return status;
341}
342EXPORT_SYMBOL_GPL(wmi_evaluate_method);
343
344/**
345 * wmidev_evaluate_method - Evaluate a WMI method
346 * @wdev: A wmi bus device from a driver
347 * @instance: Instance index
348 * @method_id: Method ID to call
349 * @in: Buffer containing input for the method call
350 * @out: Empty buffer to return the method results
351 *
352 * Call an ACPI-WMI method, the caller must free @out.
353 *
354 * Return: acpi_status signaling success or error.
355 */
356acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance, u32 method_id,
357 const struct acpi_buffer *in, struct acpi_buffer *out)
358{
359 struct guid_block *block;
360 struct wmi_block *wblock;
361 acpi_handle handle;
362 struct acpi_object_list input;
363 union acpi_object params[3];
364 char method[WMI_ACPI_METHOD_NAME_SIZE];
365
366 wblock = container_of(wdev, struct wmi_block, dev);
367 block = &wblock->gblock;
368 handle = wblock->acpi_device->handle;
369
370 if (!(block->flags & ACPI_WMI_METHOD))
371 return AE_BAD_DATA;
372
373 if (block->instance_count <= instance)
374 return AE_BAD_PARAMETER;
375
376 input.count = 2;
377 input.pointer = params;
378 params[0].type = ACPI_TYPE_INTEGER;
379 params[0].integer.value = instance;
380 params[1].type = ACPI_TYPE_INTEGER;
381 params[1].integer.value = method_id;
382
383 if (in) {
384 input.count = 3;
385
386 params[2].type = get_param_acpi_type(wblock);
387 params[2].buffer.length = in->length;
388 params[2].buffer.pointer = in->pointer;
389 }
390
391 get_acpi_method_name(wblock, 'M', method);
392
393 return acpi_evaluate_object(handle, method, &input, out);
394}
395EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
396
397static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
398 struct acpi_buffer *out)
399{
400 struct guid_block *block;
401 acpi_handle handle;
402 acpi_status status, wc_status = AE_ERROR;
403 struct acpi_object_list input;
404 union acpi_object wq_params[1];
405 char wc_method[WMI_ACPI_METHOD_NAME_SIZE];
406 char method[WMI_ACPI_METHOD_NAME_SIZE];
407
408 if (!out)
409 return AE_BAD_PARAMETER;
410
411 block = &wblock->gblock;
412 handle = wblock->acpi_device->handle;
413
414 if (block->instance_count <= instance)
415 return AE_BAD_PARAMETER;
416
417 /* Check GUID is a data block */
418 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
419 return AE_ERROR;
420
421 input.count = 1;
422 input.pointer = wq_params;
423 wq_params[0].type = ACPI_TYPE_INTEGER;
424 wq_params[0].integer.value = instance;
425
426 if (instance == 0 && test_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags))
427 input.count = 0;
428
429 /*
430 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
431 * enable collection.
432 */
433 if (block->flags & ACPI_WMI_EXPENSIVE) {
434 get_acpi_method_name(wblock, 'C', wc_method);
435
436 /*
437 * Some GUIDs break the specification by declaring themselves
438 * expensive, but have no corresponding WCxx method. So we
439 * should not fail if this happens.
440 */
441 wc_status = acpi_execute_simple_method(handle, wc_method, 1);
442 }
443
444 get_acpi_method_name(wblock, 'Q', method);
445 status = acpi_evaluate_object(handle, method, &input, out);
446
447 /*
448 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
449 * the WQxx method failed - we should disable collection anyway.
450 */
451 if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
452 /*
453 * Ignore whether this WCxx call succeeds or not since
454 * the previously executed WQxx method call might have
455 * succeeded, and returning the failing status code
456 * of this call would throw away the result of the WQxx
457 * call, potentially leaking memory.
458 */
459 acpi_execute_simple_method(handle, wc_method, 0);
460 }
461
462 return status;
463}
464
465/**
466 * wmi_query_block - Return contents of a WMI block (deprecated)
467 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
468 * @instance: Instance index
469 * @out: Empty buffer to return the contents of the data block to
470 *
471 * Query a ACPI-WMI block, the caller must free @out.
472 *
473 * Return: ACPI object containing the content of the WMI block.
474 */
475acpi_status wmi_query_block(const char *guid_string, u8 instance,
476 struct acpi_buffer *out)
477{
478 struct wmi_block *wblock;
479 struct wmi_device *wdev;
480 acpi_status status;
481
482 wdev = wmi_find_device_by_guid(guid_string);
483 if (IS_ERR(wdev))
484 return AE_ERROR;
485
486 wblock = container_of(wdev, struct wmi_block, dev);
487 status = __query_block(wblock, instance, out);
488
489 wmi_device_put(wdev);
490
491 return status;
492}
493EXPORT_SYMBOL_GPL(wmi_query_block);
494
495/**
496 * wmidev_block_query - Return contents of a WMI block
497 * @wdev: A wmi bus device from a driver
498 * @instance: Instance index
499 *
500 * Query an ACPI-WMI block, the caller must free the result.
501 *
502 * Return: ACPI object containing the content of the WMI block.
503 */
504union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
505{
506 struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
507 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
508
509 if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
510 return NULL;
511
512 return out.pointer;
513}
514EXPORT_SYMBOL_GPL(wmidev_block_query);
515
516/**
517 * wmi_set_block - Write to a WMI block (deprecated)
518 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
519 * @instance: Instance index
520 * @in: Buffer containing new values for the data block
521 *
522 * Write the contents of the input buffer to an ACPI-WMI data block.
523 *
524 * Return: acpi_status signaling success or error.
525 */
526acpi_status wmi_set_block(const char *guid_string, u8 instance, const struct acpi_buffer *in)
527{
528 struct wmi_device *wdev;
529 acpi_status status;
530
531 wdev = wmi_find_device_by_guid(guid_string);
532 if (IS_ERR(wdev))
533 return AE_ERROR;
534
535 status = wmidev_block_set(wdev, instance, in);
536 wmi_device_put(wdev);
537
538 return status;
539}
540EXPORT_SYMBOL_GPL(wmi_set_block);
541
542/**
543 * wmidev_block_set - Write to a WMI block
544 * @wdev: A wmi bus device from a driver
545 * @instance: Instance index
546 * @in: Buffer containing new values for the data block
547 *
548 * Write contents of the input buffer to an ACPI-WMI data block.
549 *
550 * Return: acpi_status signaling success or error.
551 */
552acpi_status wmidev_block_set(struct wmi_device *wdev, u8 instance, const struct acpi_buffer *in)
553{
554 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
555 acpi_handle handle = wblock->acpi_device->handle;
556 struct guid_block *block = &wblock->gblock;
557 char method[WMI_ACPI_METHOD_NAME_SIZE];
558 struct acpi_object_list input;
559 union acpi_object params[2];
560
561 if (!in)
562 return AE_BAD_DATA;
563
564 if (block->instance_count <= instance)
565 return AE_BAD_PARAMETER;
566
567 /* Check GUID is a data block */
568 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
569 return AE_ERROR;
570
571 input.count = 2;
572 input.pointer = params;
573 params[0].type = ACPI_TYPE_INTEGER;
574 params[0].integer.value = instance;
575 params[1].type = get_param_acpi_type(wblock);
576 params[1].buffer.length = in->length;
577 params[1].buffer.pointer = in->pointer;
578
579 get_acpi_method_name(wblock, 'S', method);
580
581 return acpi_evaluate_object(handle, method, &input, NULL);
582}
583EXPORT_SYMBOL_GPL(wmidev_block_set);
584
585/**
586 * wmi_install_notify_handler - Register handler for WMI events (deprecated)
587 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
588 * @handler: Function to handle notifications
589 * @data: Data to be returned to handler when event is fired
590 *
591 * Register a handler for events sent to the ACPI-WMI mapper device.
592 *
593 * Return: acpi_status signaling success or error.
594 */
595acpi_status wmi_install_notify_handler(const char *guid,
596 wmi_notify_handler handler,
597 void *data)
598{
599 struct wmi_block *wblock;
600 struct wmi_device *wdev;
601 acpi_status status;
602
603 wdev = wmi_find_device_by_guid(guid);
604 if (IS_ERR(wdev))
605 return AE_ERROR;
606
607 wblock = container_of(wdev, struct wmi_block, dev);
608
609 down_write(&wblock->notify_lock);
610 if (wblock->handler) {
611 status = AE_ALREADY_ACQUIRED;
612 } else {
613 wblock->handler = handler;
614 wblock->handler_data = data;
615
616 if (ACPI_FAILURE(wmi_method_enable(wblock, true)))
617 dev_warn(&wblock->dev.dev, "Failed to enable device\n");
618
619 status = AE_OK;
620 }
621 up_write(&wblock->notify_lock);
622
623 wmi_device_put(wdev);
624
625 return status;
626}
627EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
628
629/**
630 * wmi_remove_notify_handler - Unregister handler for WMI events (deprecated)
631 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
632 *
633 * Unregister handler for events sent to the ACPI-WMI mapper device.
634 *
635 * Return: acpi_status signaling success or error.
636 */
637acpi_status wmi_remove_notify_handler(const char *guid)
638{
639 struct wmi_block *wblock;
640 struct wmi_device *wdev;
641 acpi_status status;
642
643 wdev = wmi_find_device_by_guid(guid);
644 if (IS_ERR(wdev))
645 return AE_ERROR;
646
647 wblock = container_of(wdev, struct wmi_block, dev);
648
649 down_write(&wblock->notify_lock);
650 if (!wblock->handler) {
651 status = AE_NULL_ENTRY;
652 } else {
653 if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
654 dev_warn(&wblock->dev.dev, "Failed to disable device\n");
655
656 wblock->handler = NULL;
657 wblock->handler_data = NULL;
658
659 status = AE_OK;
660 }
661 up_write(&wblock->notify_lock);
662
663 wmi_device_put(wdev);
664
665 return status;
666}
667EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
668
669/**
670 * wmi_get_event_data - Get WMI data associated with an event (deprecated)
671 *
672 * @event: Event to find
673 * @out: Buffer to hold event data
674 *
675 * Get extra data associated with an WMI event, the caller needs to free @out.
676 *
677 * Return: acpi_status signaling success or error.
678 */
679acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
680{
681 struct wmi_block *wblock;
682 struct wmi_device *wdev;
683 acpi_status status;
684
685 wdev = wmi_find_event_by_notify_id(event);
686 if (IS_ERR(wdev))
687 return AE_NOT_FOUND;
688
689 wblock = container_of(wdev, struct wmi_block, dev);
690 status = get_event_data(wblock, out);
691
692 wmi_device_put(wdev);
693
694 return status;
695}
696EXPORT_SYMBOL_GPL(wmi_get_event_data);
697
698/**
699 * wmi_has_guid - Check if a GUID is available
700 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
701 *
702 * Check if a given GUID is defined by _WDG.
703 *
704 * Return: True if GUID is available, false otherwise.
705 */
706bool wmi_has_guid(const char *guid_string)
707{
708 struct wmi_device *wdev;
709
710 wdev = wmi_find_device_by_guid(guid_string);
711 if (IS_ERR(wdev))
712 return false;
713
714 wmi_device_put(wdev);
715
716 return true;
717}
718EXPORT_SYMBOL_GPL(wmi_has_guid);
719
720/**
721 * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID (deprecated)
722 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
723 *
724 * Find the _UID of ACPI device associated with this WMI GUID.
725 *
726 * Return: The ACPI _UID field value or NULL if the WMI GUID was not found.
727 */
728char *wmi_get_acpi_device_uid(const char *guid_string)
729{
730 struct wmi_block *wblock;
731 struct wmi_device *wdev;
732 char *uid;
733
734 wdev = wmi_find_device_by_guid(guid_string);
735 if (IS_ERR(wdev))
736 return NULL;
737
738 wblock = container_of(wdev, struct wmi_block, dev);
739 uid = acpi_device_uid(wblock->acpi_device);
740
741 wmi_device_put(wdev);
742
743 return uid;
744}
745EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
746
747static inline struct wmi_driver *drv_to_wdrv(struct device_driver *drv)
748{
749 return container_of(drv, struct wmi_driver, driver);
750}
751
752/*
753 * sysfs interface
754 */
755static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
756 char *buf)
757{
758 struct wmi_block *wblock = dev_to_wblock(dev);
759
760 return sysfs_emit(buf, "wmi:%pUL\n", &wblock->gblock.guid);
761}
762static DEVICE_ATTR_RO(modalias);
763
764static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
765 char *buf)
766{
767 struct wmi_block *wblock = dev_to_wblock(dev);
768
769 return sysfs_emit(buf, "%pUL\n", &wblock->gblock.guid);
770}
771static DEVICE_ATTR_RO(guid);
772
773static ssize_t instance_count_show(struct device *dev,
774 struct device_attribute *attr, char *buf)
775{
776 struct wmi_block *wblock = dev_to_wblock(dev);
777
778 return sysfs_emit(buf, "%d\n", (int)wblock->gblock.instance_count);
779}
780static DEVICE_ATTR_RO(instance_count);
781
782static ssize_t expensive_show(struct device *dev,
783 struct device_attribute *attr, char *buf)
784{
785 struct wmi_block *wblock = dev_to_wblock(dev);
786
787 return sysfs_emit(buf, "%d\n",
788 (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
789}
790static DEVICE_ATTR_RO(expensive);
791
792static struct attribute *wmi_attrs[] = {
793 &dev_attr_modalias.attr,
794 &dev_attr_guid.attr,
795 &dev_attr_instance_count.attr,
796 &dev_attr_expensive.attr,
797 NULL
798};
799ATTRIBUTE_GROUPS(wmi);
800
801static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
802 char *buf)
803{
804 struct wmi_block *wblock = dev_to_wblock(dev);
805
806 return sysfs_emit(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
807}
808static DEVICE_ATTR_RO(notify_id);
809
810static struct attribute *wmi_event_attrs[] = {
811 &dev_attr_notify_id.attr,
812 NULL
813};
814ATTRIBUTE_GROUPS(wmi_event);
815
816static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
817 char *buf)
818{
819 struct wmi_block *wblock = dev_to_wblock(dev);
820
821 return sysfs_emit(buf, "%c%c\n", wblock->gblock.object_id[0],
822 wblock->gblock.object_id[1]);
823}
824static DEVICE_ATTR_RO(object_id);
825
826static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
827 char *buf)
828{
829 struct wmi_device *wdev = dev_to_wdev(dev);
830
831 return sysfs_emit(buf, "%d\n", (int)wdev->setable);
832}
833static DEVICE_ATTR_RO(setable);
834
835static struct attribute *wmi_data_attrs[] = {
836 &dev_attr_object_id.attr,
837 &dev_attr_setable.attr,
838 NULL
839};
840ATTRIBUTE_GROUPS(wmi_data);
841
842static struct attribute *wmi_method_attrs[] = {
843 &dev_attr_object_id.attr,
844 NULL
845};
846ATTRIBUTE_GROUPS(wmi_method);
847
848static int wmi_dev_uevent(const struct device *dev, struct kobj_uevent_env *env)
849{
850 const struct wmi_block *wblock = dev_to_wblock(dev);
851
852 if (add_uevent_var(env, "MODALIAS=wmi:%pUL", &wblock->gblock.guid))
853 return -ENOMEM;
854
855 if (add_uevent_var(env, "WMI_GUID=%pUL", &wblock->gblock.guid))
856 return -ENOMEM;
857
858 return 0;
859}
860
861static void wmi_dev_release(struct device *dev)
862{
863 struct wmi_block *wblock = dev_to_wblock(dev);
864
865 kfree(wblock);
866}
867
868static int wmi_dev_match(struct device *dev, struct device_driver *driver)
869{
870 struct wmi_driver *wmi_driver = drv_to_wdrv(driver);
871 struct wmi_block *wblock = dev_to_wblock(dev);
872 const struct wmi_device_id *id = wmi_driver->id_table;
873
874 if (id == NULL)
875 return 0;
876
877 while (*id->guid_string) {
878 if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid))
879 return 1;
880
881 id++;
882 }
883
884 return 0;
885}
886
887static int wmi_dev_probe(struct device *dev)
888{
889 struct wmi_block *wblock = dev_to_wblock(dev);
890 struct wmi_driver *wdriver = drv_to_wdrv(dev->driver);
891 int ret = 0;
892
893 if (ACPI_FAILURE(wmi_method_enable(wblock, true)))
894 dev_warn(dev, "failed to enable device -- probing anyway\n");
895
896 if (wdriver->probe) {
897 ret = wdriver->probe(dev_to_wdev(dev),
898 find_guid_context(wblock, wdriver));
899 if (ret) {
900 if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
901 dev_warn(dev, "Failed to disable device\n");
902
903 return ret;
904 }
905 }
906
907 down_write(&wblock->notify_lock);
908 wblock->driver_ready = true;
909 up_write(&wblock->notify_lock);
910
911 return 0;
912}
913
914static void wmi_dev_remove(struct device *dev)
915{
916 struct wmi_block *wblock = dev_to_wblock(dev);
917 struct wmi_driver *wdriver = drv_to_wdrv(dev->driver);
918
919 down_write(&wblock->notify_lock);
920 wblock->driver_ready = false;
921 up_write(&wblock->notify_lock);
922
923 if (wdriver->remove)
924 wdriver->remove(dev_to_wdev(dev));
925
926 if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
927 dev_warn(dev, "failed to disable device\n");
928}
929
930static struct class wmi_bus_class = {
931 .name = "wmi_bus",
932};
933
934static struct bus_type wmi_bus_type = {
935 .name = "wmi",
936 .dev_groups = wmi_groups,
937 .match = wmi_dev_match,
938 .uevent = wmi_dev_uevent,
939 .probe = wmi_dev_probe,
940 .remove = wmi_dev_remove,
941};
942
943static const struct device_type wmi_type_event = {
944 .name = "event",
945 .groups = wmi_event_groups,
946 .release = wmi_dev_release,
947};
948
949static const struct device_type wmi_type_method = {
950 .name = "method",
951 .groups = wmi_method_groups,
952 .release = wmi_dev_release,
953};
954
955static const struct device_type wmi_type_data = {
956 .name = "data",
957 .groups = wmi_data_groups,
958 .release = wmi_dev_release,
959};
960
961/*
962 * _WDG is a static list that is only parsed at startup,
963 * so it's safe to count entries without extra protection.
964 */
965static int guid_count(const guid_t *guid)
966{
967 struct wmi_block *wblock;
968 int count = 0;
969
970 list_for_each_entry(wblock, &wmi_block_list, list) {
971 if (guid_equal(&wblock->gblock.guid, guid))
972 count++;
973 }
974
975 return count;
976}
977
978static int wmi_create_device(struct device *wmi_bus_dev,
979 struct wmi_block *wblock,
980 struct acpi_device *device)
981{
982 struct acpi_device_info *info;
983 char method[WMI_ACPI_METHOD_NAME_SIZE];
984 int result;
985 uint count;
986
987 if (wblock->gblock.flags & ACPI_WMI_EVENT) {
988 wblock->dev.dev.type = &wmi_type_event;
989 goto out_init;
990 }
991
992 if (wblock->gblock.flags & ACPI_WMI_METHOD) {
993 wblock->dev.dev.type = &wmi_type_method;
994 goto out_init;
995 }
996
997 /*
998 * Data Block Query Control Method (WQxx by convention) is
999 * required per the WMI documentation. If it is not present,
1000 * we ignore this data block.
1001 */
1002 get_acpi_method_name(wblock, 'Q', method);
1003 result = get_subobj_info(device->handle, method, &info);
1004
1005 if (result) {
1006 dev_warn(wmi_bus_dev,
1007 "%s data block query control method not found\n",
1008 method);
1009 return result;
1010 }
1011
1012 wblock->dev.dev.type = &wmi_type_data;
1013
1014 /*
1015 * The Microsoft documentation specifically states:
1016 *
1017 * Data blocks registered with only a single instance
1018 * can ignore the parameter.
1019 *
1020 * ACPICA will get mad at us if we call the method with the wrong number
1021 * of arguments, so check what our method expects. (On some Dell
1022 * laptops, WQxx may not be a method at all.)
1023 */
1024 if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1025 set_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags);
1026
1027 kfree(info);
1028
1029 get_acpi_method_name(wblock, 'S', method);
1030 if (acpi_has_method(device->handle, method))
1031 wblock->dev.setable = true;
1032
1033 out_init:
1034 init_rwsem(&wblock->notify_lock);
1035 wblock->driver_ready = false;
1036 wblock->dev.dev.bus = &wmi_bus_type;
1037 wblock->dev.dev.parent = wmi_bus_dev;
1038
1039 count = guid_count(&wblock->gblock.guid);
1040 if (count)
1041 dev_set_name(&wblock->dev.dev, "%pUL-%d", &wblock->gblock.guid, count);
1042 else
1043 dev_set_name(&wblock->dev.dev, "%pUL", &wblock->gblock.guid);
1044
1045 device_initialize(&wblock->dev.dev);
1046
1047 return 0;
1048}
1049
1050static int wmi_add_device(struct platform_device *pdev, struct wmi_device *wdev)
1051{
1052 struct device_link *link;
1053
1054 /*
1055 * Many aggregate WMI drivers do not use -EPROBE_DEFER when they
1056 * are unable to find a WMI device during probe, instead they require
1057 * all WMI devices associated with an platform device to become available
1058 * at once. This device link thus prevents WMI drivers from probing until
1059 * the associated platform device has finished probing (and has registered
1060 * all discovered WMI devices).
1061 */
1062
1063 link = device_link_add(&wdev->dev, &pdev->dev, DL_FLAG_AUTOREMOVE_SUPPLIER);
1064 if (!link)
1065 return -EINVAL;
1066
1067 return device_add(&wdev->dev);
1068}
1069
1070static bool guid_already_parsed_for_legacy(struct acpi_device *device, const guid_t *guid)
1071{
1072 struct wmi_block *wblock;
1073
1074 list_for_each_entry(wblock, &wmi_block_list, list) {
1075 /* skip warning and register if we know the driver will use struct wmi_driver */
1076 for (int i = 0; allow_duplicates[i] != NULL; i++) {
1077 if (guid_parse_and_compare(allow_duplicates[i], guid))
1078 return false;
1079 }
1080 if (guid_equal(&wblock->gblock.guid, guid)) {
1081 /*
1082 * Because we historically didn't track the relationship
1083 * between GUIDs and ACPI nodes, we don't know whether
1084 * we need to suppress GUIDs that are unique on a
1085 * given node but duplicated across nodes.
1086 */
1087 dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
1088 guid, dev_name(&wblock->acpi_device->dev));
1089 return true;
1090 }
1091 }
1092
1093 return false;
1094}
1095
1096/*
1097 * Parse the _WDG method for the GUID data blocks
1098 */
1099static int parse_wdg(struct device *wmi_bus_dev, struct platform_device *pdev)
1100{
1101 struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
1102 struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1103 const struct guid_block *gblock;
1104 struct wmi_block *wblock;
1105 union acpi_object *obj;
1106 acpi_status status;
1107 u32 i, total;
1108 int retval;
1109
1110 status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1111 if (ACPI_FAILURE(status))
1112 return -ENXIO;
1113
1114 obj = out.pointer;
1115 if (!obj)
1116 return -ENXIO;
1117
1118 if (obj->type != ACPI_TYPE_BUFFER) {
1119 kfree(obj);
1120 return -ENXIO;
1121 }
1122
1123 gblock = (const struct guid_block *)obj->buffer.pointer;
1124 total = obj->buffer.length / sizeof(struct guid_block);
1125
1126 for (i = 0; i < total; i++) {
1127 if (!gblock[i].instance_count) {
1128 dev_info(wmi_bus_dev, FW_INFO "%pUL has zero instances\n", &gblock[i].guid);
1129 continue;
1130 }
1131
1132 if (guid_already_parsed_for_legacy(device, &gblock[i].guid))
1133 continue;
1134
1135 wblock = kzalloc(sizeof(*wblock), GFP_KERNEL);
1136 if (!wblock) {
1137 dev_err(wmi_bus_dev, "Failed to allocate %pUL\n", &gblock[i].guid);
1138 continue;
1139 }
1140
1141 wblock->acpi_device = device;
1142 wblock->gblock = gblock[i];
1143
1144 retval = wmi_create_device(wmi_bus_dev, wblock, device);
1145 if (retval) {
1146 kfree(wblock);
1147 continue;
1148 }
1149
1150 list_add_tail(&wblock->list, &wmi_block_list);
1151
1152 retval = wmi_add_device(pdev, &wblock->dev);
1153 if (retval) {
1154 dev_err(wmi_bus_dev, "failed to register %pUL\n",
1155 &wblock->gblock.guid);
1156
1157 list_del(&wblock->list);
1158 put_device(&wblock->dev.dev);
1159 }
1160 }
1161
1162 kfree(obj);
1163
1164 return 0;
1165}
1166
1167/*
1168 * WMI can have EmbeddedControl access regions. In which case, we just want to
1169 * hand these off to the EC driver.
1170 */
1171static acpi_status
1172acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1173 u32 bits, u64 *value,
1174 void *handler_context, void *region_context)
1175{
1176 int result = 0;
1177 u8 temp = 0;
1178
1179 if ((address > 0xFF) || !value)
1180 return AE_BAD_PARAMETER;
1181
1182 if (function != ACPI_READ && function != ACPI_WRITE)
1183 return AE_BAD_PARAMETER;
1184
1185 if (bits != 8)
1186 return AE_BAD_PARAMETER;
1187
1188 if (function == ACPI_READ) {
1189 result = ec_read(address, &temp);
1190 *value = temp;
1191 } else {
1192 temp = 0xff & *value;
1193 result = ec_write(address, temp);
1194 }
1195
1196 switch (result) {
1197 case -EINVAL:
1198 return AE_BAD_PARAMETER;
1199 case -ENODEV:
1200 return AE_NOT_FOUND;
1201 case -ETIME:
1202 return AE_TIME;
1203 default:
1204 return AE_OK;
1205 }
1206}
1207
1208static void wmi_notify_driver(struct wmi_block *wblock)
1209{
1210 struct wmi_driver *driver = drv_to_wdrv(wblock->dev.dev.driver);
1211 struct acpi_buffer data = { ACPI_ALLOCATE_BUFFER, NULL };
1212 acpi_status status;
1213
1214 if (!driver->no_notify_data) {
1215 status = get_event_data(wblock, &data);
1216 if (ACPI_FAILURE(status)) {
1217 dev_warn(&wblock->dev.dev, "Failed to get event data\n");
1218 return;
1219 }
1220 }
1221
1222 if (driver->notify)
1223 driver->notify(&wblock->dev, data.pointer);
1224
1225 kfree(data.pointer);
1226}
1227
1228static int wmi_notify_device(struct device *dev, void *data)
1229{
1230 struct wmi_block *wblock = dev_to_wblock(dev);
1231 u32 *event = data;
1232
1233 if (!(wblock->gblock.flags & ACPI_WMI_EVENT && wblock->gblock.notify_id == *event))
1234 return 0;
1235
1236 down_read(&wblock->notify_lock);
1237 /* The WMI driver notify handler conflicts with the legacy WMI handler.
1238 * Because of this the WMI driver notify handler takes precedence.
1239 */
1240 if (wblock->dev.dev.driver && wblock->driver_ready) {
1241 wmi_notify_driver(wblock);
1242 } else {
1243 if (wblock->handler)
1244 wblock->handler(*event, wblock->handler_data);
1245 }
1246 up_read(&wblock->notify_lock);
1247
1248 acpi_bus_generate_netlink_event(wblock->acpi_device->pnp.device_class,
1249 dev_name(&wblock->dev.dev), *event, 0);
1250
1251 return -EBUSY;
1252}
1253
1254static void acpi_wmi_notify_handler(acpi_handle handle, u32 event, void *context)
1255{
1256 struct device *wmi_bus_dev = context;
1257
1258 device_for_each_child(wmi_bus_dev, &event, wmi_notify_device);
1259}
1260
1261static int wmi_remove_device(struct device *dev, void *data)
1262{
1263 struct wmi_block *wblock = dev_to_wblock(dev);
1264
1265 list_del(&wblock->list);
1266 device_unregister(dev);
1267
1268 return 0;
1269}
1270
1271static void acpi_wmi_remove(struct platform_device *device)
1272{
1273 struct device *wmi_bus_device = dev_get_drvdata(&device->dev);
1274
1275 device_for_each_child_reverse(wmi_bus_device, NULL, wmi_remove_device);
1276}
1277
1278static void acpi_wmi_remove_notify_handler(void *data)
1279{
1280 struct acpi_device *acpi_device = data;
1281
1282 acpi_remove_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY, acpi_wmi_notify_handler);
1283}
1284
1285static void acpi_wmi_remove_address_space_handler(void *data)
1286{
1287 struct acpi_device *acpi_device = data;
1288
1289 acpi_remove_address_space_handler(acpi_device->handle, ACPI_ADR_SPACE_EC,
1290 &acpi_wmi_ec_space_handler);
1291}
1292
1293static void acpi_wmi_remove_bus_device(void *data)
1294{
1295 struct device *wmi_bus_dev = data;
1296
1297 device_unregister(wmi_bus_dev);
1298}
1299
1300static int acpi_wmi_probe(struct platform_device *device)
1301{
1302 struct acpi_device *acpi_device;
1303 struct device *wmi_bus_dev;
1304 acpi_status status;
1305 int error;
1306
1307 acpi_device = ACPI_COMPANION(&device->dev);
1308 if (!acpi_device) {
1309 dev_err(&device->dev, "ACPI companion is missing\n");
1310 return -ENODEV;
1311 }
1312
1313 wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0), NULL, "wmi_bus-%s",
1314 dev_name(&device->dev));
1315 if (IS_ERR(wmi_bus_dev))
1316 return PTR_ERR(wmi_bus_dev);
1317
1318 error = devm_add_action_or_reset(&device->dev, acpi_wmi_remove_bus_device, wmi_bus_dev);
1319 if (error < 0)
1320 return error;
1321
1322 dev_set_drvdata(&device->dev, wmi_bus_dev);
1323
1324 status = acpi_install_address_space_handler(acpi_device->handle,
1325 ACPI_ADR_SPACE_EC,
1326 &acpi_wmi_ec_space_handler,
1327 NULL, NULL);
1328 if (ACPI_FAILURE(status)) {
1329 dev_err(&device->dev, "Error installing EC region handler\n");
1330 return -ENODEV;
1331 }
1332 error = devm_add_action_or_reset(&device->dev, acpi_wmi_remove_address_space_handler,
1333 acpi_device);
1334 if (error < 0)
1335 return error;
1336
1337 status = acpi_install_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY,
1338 acpi_wmi_notify_handler, wmi_bus_dev);
1339 if (ACPI_FAILURE(status)) {
1340 dev_err(&device->dev, "Error installing notify handler\n");
1341 return -ENODEV;
1342 }
1343 error = devm_add_action_or_reset(&device->dev, acpi_wmi_remove_notify_handler,
1344 acpi_device);
1345 if (error < 0)
1346 return error;
1347
1348 error = parse_wdg(wmi_bus_dev, device);
1349 if (error) {
1350 pr_err("Failed to parse WDG method\n");
1351 return error;
1352 }
1353
1354 return 0;
1355}
1356
1357int __must_check __wmi_driver_register(struct wmi_driver *driver,
1358 struct module *owner)
1359{
1360 driver->driver.owner = owner;
1361 driver->driver.bus = &wmi_bus_type;
1362
1363 return driver_register(&driver->driver);
1364}
1365EXPORT_SYMBOL(__wmi_driver_register);
1366
1367/**
1368 * wmi_driver_unregister() - Unregister a WMI driver
1369 * @driver: WMI driver to unregister
1370 *
1371 * Unregisters a WMI driver from the WMI bus.
1372 */
1373void wmi_driver_unregister(struct wmi_driver *driver)
1374{
1375 driver_unregister(&driver->driver);
1376}
1377EXPORT_SYMBOL(wmi_driver_unregister);
1378
1379static struct platform_driver acpi_wmi_driver = {
1380 .driver = {
1381 .name = "acpi-wmi",
1382 .acpi_match_table = wmi_device_ids,
1383 },
1384 .probe = acpi_wmi_probe,
1385 .remove_new = acpi_wmi_remove,
1386};
1387
1388static int __init acpi_wmi_init(void)
1389{
1390 int error;
1391
1392 if (acpi_disabled)
1393 return -ENODEV;
1394
1395 error = class_register(&wmi_bus_class);
1396 if (error)
1397 return error;
1398
1399 error = bus_register(&wmi_bus_type);
1400 if (error)
1401 goto err_unreg_class;
1402
1403 error = platform_driver_register(&acpi_wmi_driver);
1404 if (error) {
1405 pr_err("Error loading mapper\n");
1406 goto err_unreg_bus;
1407 }
1408
1409 return 0;
1410
1411err_unreg_bus:
1412 bus_unregister(&wmi_bus_type);
1413
1414err_unreg_class:
1415 class_unregister(&wmi_bus_class);
1416
1417 return error;
1418}
1419
1420static void __exit acpi_wmi_exit(void)
1421{
1422 platform_driver_unregister(&acpi_wmi_driver);
1423 bus_unregister(&wmi_bus_type);
1424 class_unregister(&wmi_bus_class);
1425}
1426
1427subsys_initcall_sync(acpi_wmi_init);
1428module_exit(acpi_wmi_exit);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * ACPI-WMI mapping driver
4 *
5 * Copyright (C) 2007-2008 Carlos Corbacho <carlos@strangeworlds.co.uk>
6 *
7 * GUID parsing code from ldm.c is:
8 * Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
9 * Copyright (c) 2001-2007 Anton Altaparmakov
10 * Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
11 *
12 * WMI bus infrastructure by Andrew Lutomirski and Darren Hart:
13 * Copyright (C) 2015 Andrew Lutomirski
14 * Copyright (C) 2017 VMware, Inc. All Rights Reserved.
15 */
16
17#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18
19#include <linux/acpi.h>
20#include <linux/bits.h>
21#include <linux/build_bug.h>
22#include <linux/device.h>
23#include <linux/init.h>
24#include <linux/kernel.h>
25#include <linux/module.h>
26#include <linux/platform_device.h>
27#include <linux/rwsem.h>
28#include <linux/slab.h>
29#include <linux/sysfs.h>
30#include <linux/types.h>
31#include <linux/uuid.h>
32#include <linux/wmi.h>
33#include <linux/fs.h>
34
35MODULE_AUTHOR("Carlos Corbacho");
36MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
37MODULE_LICENSE("GPL");
38
39struct guid_block {
40 guid_t guid;
41 union {
42 char object_id[2];
43 struct {
44 unsigned char notify_id;
45 unsigned char reserved;
46 };
47 };
48 u8 instance_count;
49 u8 flags;
50} __packed;
51static_assert(sizeof(typeof_member(struct guid_block, guid)) == 16);
52static_assert(sizeof(struct guid_block) == 20);
53static_assert(__alignof__(struct guid_block) == 1);
54
55enum { /* wmi_block flags */
56 WMI_READ_TAKES_NO_ARGS,
57 WMI_GUID_DUPLICATED,
58 WMI_NO_EVENT_DATA,
59};
60
61struct wmi_block {
62 struct wmi_device dev;
63 struct guid_block gblock;
64 struct acpi_device *acpi_device;
65 struct rw_semaphore notify_lock; /* Protects notify callback add/remove */
66 wmi_notify_handler handler;
67 void *handler_data;
68 bool driver_ready;
69 unsigned long flags;
70};
71
72struct wmi_guid_count_context {
73 const guid_t *guid;
74 int count;
75};
76
77/*
78 * If the GUID data block is marked as expensive, we must enable and
79 * explicitily disable data collection.
80 */
81#define ACPI_WMI_EXPENSIVE BIT(0)
82#define ACPI_WMI_METHOD BIT(1) /* GUID is a method */
83#define ACPI_WMI_STRING BIT(2) /* GUID takes & returns a string */
84#define ACPI_WMI_EVENT BIT(3) /* GUID is an event */
85
86static const struct acpi_device_id wmi_device_ids[] = {
87 {"PNP0C14", 0},
88 {"pnp0c14", 0},
89 { }
90};
91MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
92
93#define dev_to_wblock(__dev) container_of_const(__dev, struct wmi_block, dev.dev)
94
95/*
96 * GUID parsing functions
97 */
98
99static bool guid_parse_and_compare(const char *string, const guid_t *guid)
100{
101 guid_t guid_input;
102
103 if (guid_parse(string, &guid_input))
104 return false;
105
106 return guid_equal(&guid_input, guid);
107}
108
109static const void *find_guid_context(struct wmi_block *wblock,
110 struct wmi_driver *wdriver)
111{
112 const struct wmi_device_id *id;
113
114 id = wdriver->id_table;
115 if (!id)
116 return NULL;
117
118 while (*id->guid_string) {
119 if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid))
120 return id->context;
121 id++;
122 }
123 return NULL;
124}
125
126static acpi_status wmi_method_enable(struct wmi_block *wblock, bool enable)
127{
128 struct guid_block *block;
129 char method[5];
130 acpi_status status;
131 acpi_handle handle;
132
133 block = &wblock->gblock;
134 handle = wblock->acpi_device->handle;
135
136 snprintf(method, 5, "WE%02X", block->notify_id);
137 status = acpi_execute_simple_method(handle, method, enable);
138 if (status == AE_NOT_FOUND)
139 return AE_OK;
140
141 return status;
142}
143
144#define WMI_ACPI_METHOD_NAME_SIZE 5
145
146static inline void get_acpi_method_name(const struct wmi_block *wblock,
147 const char method,
148 char buffer[static WMI_ACPI_METHOD_NAME_SIZE])
149{
150 static_assert(ARRAY_SIZE(wblock->gblock.object_id) == 2);
151 static_assert(WMI_ACPI_METHOD_NAME_SIZE >= 5);
152
153 buffer[0] = 'W';
154 buffer[1] = method;
155 buffer[2] = wblock->gblock.object_id[0];
156 buffer[3] = wblock->gblock.object_id[1];
157 buffer[4] = '\0';
158}
159
160static inline acpi_object_type get_param_acpi_type(const struct wmi_block *wblock)
161{
162 if (wblock->gblock.flags & ACPI_WMI_STRING)
163 return ACPI_TYPE_STRING;
164 else
165 return ACPI_TYPE_BUFFER;
166}
167
168static int wmidev_match_guid(struct device *dev, const void *data)
169{
170 struct wmi_block *wblock = dev_to_wblock(dev);
171 const guid_t *guid = data;
172
173 /* Legacy GUID-based functions are restricted to only see
174 * a single WMI device for each GUID.
175 */
176 if (test_bit(WMI_GUID_DUPLICATED, &wblock->flags))
177 return 0;
178
179 if (guid_equal(guid, &wblock->gblock.guid))
180 return 1;
181
182 return 0;
183}
184
185static const struct bus_type wmi_bus_type;
186
187static struct wmi_device *wmi_find_device_by_guid(const char *guid_string)
188{
189 struct device *dev;
190 guid_t guid;
191 int ret;
192
193 ret = guid_parse(guid_string, &guid);
194 if (ret < 0)
195 return ERR_PTR(ret);
196
197 dev = bus_find_device(&wmi_bus_type, NULL, &guid, wmidev_match_guid);
198 if (!dev)
199 return ERR_PTR(-ENODEV);
200
201 return to_wmi_device(dev);
202}
203
204static void wmi_device_put(struct wmi_device *wdev)
205{
206 put_device(&wdev->dev);
207}
208
209/*
210 * Exported WMI functions
211 */
212
213/**
214 * wmi_instance_count - Get number of WMI object instances
215 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
216 *
217 * Get the number of WMI object instances.
218 *
219 * Returns: Number of WMI object instances or negative error code.
220 */
221int wmi_instance_count(const char *guid_string)
222{
223 struct wmi_device *wdev;
224 int ret;
225
226 wdev = wmi_find_device_by_guid(guid_string);
227 if (IS_ERR(wdev))
228 return PTR_ERR(wdev);
229
230 ret = wmidev_instance_count(wdev);
231 wmi_device_put(wdev);
232
233 return ret;
234}
235EXPORT_SYMBOL_GPL(wmi_instance_count);
236
237/**
238 * wmidev_instance_count - Get number of WMI object instances
239 * @wdev: A wmi bus device from a driver
240 *
241 * Get the number of WMI object instances.
242 *
243 * Returns: Number of WMI object instances.
244 */
245u8 wmidev_instance_count(struct wmi_device *wdev)
246{
247 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
248
249 return wblock->gblock.instance_count;
250}
251EXPORT_SYMBOL_GPL(wmidev_instance_count);
252
253/**
254 * wmi_evaluate_method - Evaluate a WMI method (deprecated)
255 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
256 * @instance: Instance index
257 * @method_id: Method ID to call
258 * @in: Mandatory buffer containing input for the method call
259 * @out: Empty buffer to return the method results
260 *
261 * Call an ACPI-WMI method, the caller must free @out.
262 *
263 * Return: acpi_status signaling success or error.
264 */
265acpi_status wmi_evaluate_method(const char *guid_string, u8 instance, u32 method_id,
266 const struct acpi_buffer *in, struct acpi_buffer *out)
267{
268 struct wmi_device *wdev;
269 acpi_status status;
270
271 wdev = wmi_find_device_by_guid(guid_string);
272 if (IS_ERR(wdev))
273 return AE_ERROR;
274
275 status = wmidev_evaluate_method(wdev, instance, method_id, in, out);
276
277 wmi_device_put(wdev);
278
279 return status;
280}
281EXPORT_SYMBOL_GPL(wmi_evaluate_method);
282
283/**
284 * wmidev_evaluate_method - Evaluate a WMI method
285 * @wdev: A wmi bus device from a driver
286 * @instance: Instance index
287 * @method_id: Method ID to call
288 * @in: Mandatory buffer containing input for the method call
289 * @out: Empty buffer to return the method results
290 *
291 * Call an ACPI-WMI method, the caller must free @out.
292 *
293 * Return: acpi_status signaling success or error.
294 */
295acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance, u32 method_id,
296 const struct acpi_buffer *in, struct acpi_buffer *out)
297{
298 struct guid_block *block;
299 struct wmi_block *wblock;
300 acpi_handle handle;
301 struct acpi_object_list input;
302 union acpi_object params[3];
303 char method[WMI_ACPI_METHOD_NAME_SIZE];
304
305 wblock = container_of(wdev, struct wmi_block, dev);
306 block = &wblock->gblock;
307 handle = wblock->acpi_device->handle;
308
309 if (!in)
310 return AE_BAD_DATA;
311
312 if (!(block->flags & ACPI_WMI_METHOD))
313 return AE_BAD_DATA;
314
315 if (block->instance_count <= instance)
316 return AE_BAD_PARAMETER;
317
318 input.count = 3;
319 input.pointer = params;
320
321 params[0].type = ACPI_TYPE_INTEGER;
322 params[0].integer.value = instance;
323 params[1].type = ACPI_TYPE_INTEGER;
324 params[1].integer.value = method_id;
325 params[2].type = get_param_acpi_type(wblock);
326 params[2].buffer.length = in->length;
327 params[2].buffer.pointer = in->pointer;
328
329 get_acpi_method_name(wblock, 'M', method);
330
331 return acpi_evaluate_object(handle, method, &input, out);
332}
333EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
334
335static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
336 struct acpi_buffer *out)
337{
338 struct guid_block *block;
339 acpi_handle handle;
340 acpi_status status, wc_status = AE_ERROR;
341 struct acpi_object_list input;
342 union acpi_object wq_params[1];
343 char wc_method[WMI_ACPI_METHOD_NAME_SIZE];
344 char method[WMI_ACPI_METHOD_NAME_SIZE];
345
346 if (!out)
347 return AE_BAD_PARAMETER;
348
349 block = &wblock->gblock;
350 handle = wblock->acpi_device->handle;
351
352 if (block->instance_count <= instance)
353 return AE_BAD_PARAMETER;
354
355 /* Check GUID is a data block */
356 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
357 return AE_ERROR;
358
359 input.count = 1;
360 input.pointer = wq_params;
361 wq_params[0].type = ACPI_TYPE_INTEGER;
362 wq_params[0].integer.value = instance;
363
364 if (instance == 0 && test_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags))
365 input.count = 0;
366
367 /*
368 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
369 * enable collection.
370 */
371 if (block->flags & ACPI_WMI_EXPENSIVE) {
372 get_acpi_method_name(wblock, 'C', wc_method);
373
374 /*
375 * Some GUIDs break the specification by declaring themselves
376 * expensive, but have no corresponding WCxx method. So we
377 * should not fail if this happens.
378 */
379 wc_status = acpi_execute_simple_method(handle, wc_method, 1);
380 }
381
382 get_acpi_method_name(wblock, 'Q', method);
383 status = acpi_evaluate_object(handle, method, &input, out);
384
385 /*
386 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
387 * the WQxx method failed - we should disable collection anyway.
388 */
389 if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
390 /*
391 * Ignore whether this WCxx call succeeds or not since
392 * the previously executed WQxx method call might have
393 * succeeded, and returning the failing status code
394 * of this call would throw away the result of the WQxx
395 * call, potentially leaking memory.
396 */
397 acpi_execute_simple_method(handle, wc_method, 0);
398 }
399
400 return status;
401}
402
403/**
404 * wmi_query_block - Return contents of a WMI block (deprecated)
405 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
406 * @instance: Instance index
407 * @out: Empty buffer to return the contents of the data block to
408 *
409 * Query a ACPI-WMI block, the caller must free @out.
410 *
411 * Return: ACPI object containing the content of the WMI block.
412 */
413acpi_status wmi_query_block(const char *guid_string, u8 instance,
414 struct acpi_buffer *out)
415{
416 struct wmi_block *wblock;
417 struct wmi_device *wdev;
418 acpi_status status;
419
420 wdev = wmi_find_device_by_guid(guid_string);
421 if (IS_ERR(wdev))
422 return AE_ERROR;
423
424 wblock = container_of(wdev, struct wmi_block, dev);
425 status = __query_block(wblock, instance, out);
426
427 wmi_device_put(wdev);
428
429 return status;
430}
431EXPORT_SYMBOL_GPL(wmi_query_block);
432
433/**
434 * wmidev_block_query - Return contents of a WMI block
435 * @wdev: A wmi bus device from a driver
436 * @instance: Instance index
437 *
438 * Query an ACPI-WMI block, the caller must free the result.
439 *
440 * Return: ACPI object containing the content of the WMI block.
441 */
442union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
443{
444 struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
445 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
446
447 if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
448 return NULL;
449
450 return out.pointer;
451}
452EXPORT_SYMBOL_GPL(wmidev_block_query);
453
454/**
455 * wmi_set_block - Write to a WMI block (deprecated)
456 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
457 * @instance: Instance index
458 * @in: Buffer containing new values for the data block
459 *
460 * Write the contents of the input buffer to an ACPI-WMI data block.
461 *
462 * Return: acpi_status signaling success or error.
463 */
464acpi_status wmi_set_block(const char *guid_string, u8 instance, const struct acpi_buffer *in)
465{
466 struct wmi_device *wdev;
467 acpi_status status;
468
469 wdev = wmi_find_device_by_guid(guid_string);
470 if (IS_ERR(wdev))
471 return AE_ERROR;
472
473 status = wmidev_block_set(wdev, instance, in);
474 wmi_device_put(wdev);
475
476 return status;
477}
478EXPORT_SYMBOL_GPL(wmi_set_block);
479
480/**
481 * wmidev_block_set - Write to a WMI block
482 * @wdev: A wmi bus device from a driver
483 * @instance: Instance index
484 * @in: Buffer containing new values for the data block
485 *
486 * Write contents of the input buffer to an ACPI-WMI data block.
487 *
488 * Return: acpi_status signaling success or error.
489 */
490acpi_status wmidev_block_set(struct wmi_device *wdev, u8 instance, const struct acpi_buffer *in)
491{
492 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
493 acpi_handle handle = wblock->acpi_device->handle;
494 struct guid_block *block = &wblock->gblock;
495 char method[WMI_ACPI_METHOD_NAME_SIZE];
496 struct acpi_object_list input;
497 union acpi_object params[2];
498
499 if (!in)
500 return AE_BAD_DATA;
501
502 if (block->instance_count <= instance)
503 return AE_BAD_PARAMETER;
504
505 /* Check GUID is a data block */
506 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
507 return AE_ERROR;
508
509 input.count = 2;
510 input.pointer = params;
511 params[0].type = ACPI_TYPE_INTEGER;
512 params[0].integer.value = instance;
513 params[1].type = get_param_acpi_type(wblock);
514 params[1].buffer.length = in->length;
515 params[1].buffer.pointer = in->pointer;
516
517 get_acpi_method_name(wblock, 'S', method);
518
519 return acpi_evaluate_object(handle, method, &input, NULL);
520}
521EXPORT_SYMBOL_GPL(wmidev_block_set);
522
523/**
524 * wmi_install_notify_handler - Register handler for WMI events (deprecated)
525 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
526 * @handler: Function to handle notifications
527 * @data: Data to be returned to handler when event is fired
528 *
529 * Register a handler for events sent to the ACPI-WMI mapper device.
530 *
531 * Return: acpi_status signaling success or error.
532 */
533acpi_status wmi_install_notify_handler(const char *guid,
534 wmi_notify_handler handler,
535 void *data)
536{
537 struct wmi_block *wblock;
538 struct wmi_device *wdev;
539 acpi_status status;
540
541 wdev = wmi_find_device_by_guid(guid);
542 if (IS_ERR(wdev))
543 return AE_ERROR;
544
545 wblock = container_of(wdev, struct wmi_block, dev);
546
547 down_write(&wblock->notify_lock);
548 if (wblock->handler) {
549 status = AE_ALREADY_ACQUIRED;
550 } else {
551 wblock->handler = handler;
552 wblock->handler_data = data;
553
554 if (ACPI_FAILURE(wmi_method_enable(wblock, true)))
555 dev_warn(&wblock->dev.dev, "Failed to enable device\n");
556
557 status = AE_OK;
558 }
559 up_write(&wblock->notify_lock);
560
561 wmi_device_put(wdev);
562
563 return status;
564}
565EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
566
567/**
568 * wmi_remove_notify_handler - Unregister handler for WMI events (deprecated)
569 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
570 *
571 * Unregister handler for events sent to the ACPI-WMI mapper device.
572 *
573 * Return: acpi_status signaling success or error.
574 */
575acpi_status wmi_remove_notify_handler(const char *guid)
576{
577 struct wmi_block *wblock;
578 struct wmi_device *wdev;
579 acpi_status status;
580
581 wdev = wmi_find_device_by_guid(guid);
582 if (IS_ERR(wdev))
583 return AE_ERROR;
584
585 wblock = container_of(wdev, struct wmi_block, dev);
586
587 down_write(&wblock->notify_lock);
588 if (!wblock->handler) {
589 status = AE_NULL_ENTRY;
590 } else {
591 if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
592 dev_warn(&wblock->dev.dev, "Failed to disable device\n");
593
594 wblock->handler = NULL;
595 wblock->handler_data = NULL;
596
597 status = AE_OK;
598 }
599 up_write(&wblock->notify_lock);
600
601 wmi_device_put(wdev);
602
603 return status;
604}
605EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
606
607/**
608 * wmi_has_guid - Check if a GUID is available
609 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
610 *
611 * Check if a given GUID is defined by _WDG.
612 *
613 * Return: True if GUID is available, false otherwise.
614 */
615bool wmi_has_guid(const char *guid_string)
616{
617 struct wmi_device *wdev;
618
619 wdev = wmi_find_device_by_guid(guid_string);
620 if (IS_ERR(wdev))
621 return false;
622
623 wmi_device_put(wdev);
624
625 return true;
626}
627EXPORT_SYMBOL_GPL(wmi_has_guid);
628
629/**
630 * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID (deprecated)
631 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
632 *
633 * Find the _UID of ACPI device associated with this WMI GUID.
634 *
635 * Return: The ACPI _UID field value or NULL if the WMI GUID was not found.
636 */
637char *wmi_get_acpi_device_uid(const char *guid_string)
638{
639 struct wmi_block *wblock;
640 struct wmi_device *wdev;
641 char *uid;
642
643 wdev = wmi_find_device_by_guid(guid_string);
644 if (IS_ERR(wdev))
645 return NULL;
646
647 wblock = container_of(wdev, struct wmi_block, dev);
648 uid = acpi_device_uid(wblock->acpi_device);
649
650 wmi_device_put(wdev);
651
652 return uid;
653}
654EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
655
656/*
657 * sysfs interface
658 */
659static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
660 char *buf)
661{
662 struct wmi_block *wblock = dev_to_wblock(dev);
663
664 return sysfs_emit(buf, "wmi:%pUL\n", &wblock->gblock.guid);
665}
666static DEVICE_ATTR_RO(modalias);
667
668static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
669 char *buf)
670{
671 struct wmi_block *wblock = dev_to_wblock(dev);
672
673 return sysfs_emit(buf, "%pUL\n", &wblock->gblock.guid);
674}
675static DEVICE_ATTR_RO(guid);
676
677static ssize_t instance_count_show(struct device *dev,
678 struct device_attribute *attr, char *buf)
679{
680 struct wmi_block *wblock = dev_to_wblock(dev);
681
682 return sysfs_emit(buf, "%d\n", (int)wblock->gblock.instance_count);
683}
684static DEVICE_ATTR_RO(instance_count);
685
686static ssize_t expensive_show(struct device *dev,
687 struct device_attribute *attr, char *buf)
688{
689 struct wmi_block *wblock = dev_to_wblock(dev);
690
691 return sysfs_emit(buf, "%d\n",
692 (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
693}
694static DEVICE_ATTR_RO(expensive);
695
696static ssize_t driver_override_show(struct device *dev, struct device_attribute *attr,
697 char *buf)
698{
699 struct wmi_device *wdev = to_wmi_device(dev);
700 ssize_t ret;
701
702 device_lock(dev);
703 ret = sysfs_emit(buf, "%s\n", wdev->driver_override);
704 device_unlock(dev);
705
706 return ret;
707}
708
709static ssize_t driver_override_store(struct device *dev, struct device_attribute *attr,
710 const char *buf, size_t count)
711{
712 struct wmi_device *wdev = to_wmi_device(dev);
713 int ret;
714
715 ret = driver_set_override(dev, &wdev->driver_override, buf, count);
716 if (ret < 0)
717 return ret;
718
719 return count;
720}
721static DEVICE_ATTR_RW(driver_override);
722
723static struct attribute *wmi_attrs[] = {
724 &dev_attr_modalias.attr,
725 &dev_attr_guid.attr,
726 &dev_attr_instance_count.attr,
727 &dev_attr_expensive.attr,
728 &dev_attr_driver_override.attr,
729 NULL
730};
731ATTRIBUTE_GROUPS(wmi);
732
733static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
734 char *buf)
735{
736 struct wmi_block *wblock = dev_to_wblock(dev);
737
738 return sysfs_emit(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
739}
740static DEVICE_ATTR_RO(notify_id);
741
742static struct attribute *wmi_event_attrs[] = {
743 &dev_attr_notify_id.attr,
744 NULL
745};
746ATTRIBUTE_GROUPS(wmi_event);
747
748static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
749 char *buf)
750{
751 struct wmi_block *wblock = dev_to_wblock(dev);
752
753 return sysfs_emit(buf, "%c%c\n", wblock->gblock.object_id[0],
754 wblock->gblock.object_id[1]);
755}
756static DEVICE_ATTR_RO(object_id);
757
758static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
759 char *buf)
760{
761 struct wmi_device *wdev = to_wmi_device(dev);
762
763 return sysfs_emit(buf, "%d\n", (int)wdev->setable);
764}
765static DEVICE_ATTR_RO(setable);
766
767static struct attribute *wmi_data_attrs[] = {
768 &dev_attr_object_id.attr,
769 &dev_attr_setable.attr,
770 NULL
771};
772ATTRIBUTE_GROUPS(wmi_data);
773
774static struct attribute *wmi_method_attrs[] = {
775 &dev_attr_object_id.attr,
776 NULL
777};
778ATTRIBUTE_GROUPS(wmi_method);
779
780static int wmi_dev_uevent(const struct device *dev, struct kobj_uevent_env *env)
781{
782 const struct wmi_block *wblock = dev_to_wblock(dev);
783
784 if (add_uevent_var(env, "MODALIAS=wmi:%pUL", &wblock->gblock.guid))
785 return -ENOMEM;
786
787 if (add_uevent_var(env, "WMI_GUID=%pUL", &wblock->gblock.guid))
788 return -ENOMEM;
789
790 return 0;
791}
792
793static void wmi_dev_release(struct device *dev)
794{
795 struct wmi_block *wblock = dev_to_wblock(dev);
796
797 kfree(wblock->dev.driver_override);
798 kfree(wblock);
799}
800
801static int wmi_dev_match(struct device *dev, const struct device_driver *driver)
802{
803 const struct wmi_driver *wmi_driver = to_wmi_driver(driver);
804 struct wmi_block *wblock = dev_to_wblock(dev);
805 const struct wmi_device_id *id = wmi_driver->id_table;
806
807 /* When driver_override is set, only bind to the matching driver */
808 if (wblock->dev.driver_override)
809 return !strcmp(wblock->dev.driver_override, driver->name);
810
811 if (id == NULL)
812 return 0;
813
814 while (*id->guid_string) {
815 if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid))
816 return 1;
817
818 id++;
819 }
820
821 return 0;
822}
823
824static int wmi_dev_probe(struct device *dev)
825{
826 struct wmi_block *wblock = dev_to_wblock(dev);
827 struct wmi_driver *wdriver = to_wmi_driver(dev->driver);
828 int ret = 0;
829
830 /* Some older WMI drivers will break if instantiated multiple times,
831 * so they are blocked from probing WMI devices with a duplicated GUID.
832 *
833 * New WMI drivers should support being instantiated multiple times.
834 */
835 if (test_bit(WMI_GUID_DUPLICATED, &wblock->flags) && !wdriver->no_singleton) {
836 dev_warn(dev, "Legacy driver %s cannot be instantiated multiple times\n",
837 dev->driver->name);
838
839 return -ENODEV;
840 }
841
842 if (wdriver->notify) {
843 if (test_bit(WMI_NO_EVENT_DATA, &wblock->flags) && !wdriver->no_notify_data)
844 return -ENODEV;
845 }
846
847 if (ACPI_FAILURE(wmi_method_enable(wblock, true)))
848 dev_warn(dev, "failed to enable device -- probing anyway\n");
849
850 if (wdriver->probe) {
851 ret = wdriver->probe(to_wmi_device(dev),
852 find_guid_context(wblock, wdriver));
853 if (ret) {
854 if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
855 dev_warn(dev, "Failed to disable device\n");
856
857 return ret;
858 }
859 }
860
861 down_write(&wblock->notify_lock);
862 wblock->driver_ready = true;
863 up_write(&wblock->notify_lock);
864
865 return 0;
866}
867
868static void wmi_dev_remove(struct device *dev)
869{
870 struct wmi_block *wblock = dev_to_wblock(dev);
871 struct wmi_driver *wdriver = to_wmi_driver(dev->driver);
872
873 down_write(&wblock->notify_lock);
874 wblock->driver_ready = false;
875 up_write(&wblock->notify_lock);
876
877 if (wdriver->remove)
878 wdriver->remove(to_wmi_device(dev));
879
880 if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
881 dev_warn(dev, "failed to disable device\n");
882}
883
884static void wmi_dev_shutdown(struct device *dev)
885{
886 struct wmi_driver *wdriver;
887 struct wmi_block *wblock;
888
889 if (dev->driver) {
890 wdriver = to_wmi_driver(dev->driver);
891 wblock = dev_to_wblock(dev);
892
893 /*
894 * Some machines return bogus WMI event data when disabling
895 * the WMI event. Because of this we must prevent the associated
896 * WMI driver from receiving new WMI events before disabling it.
897 */
898 down_write(&wblock->notify_lock);
899 wblock->driver_ready = false;
900 up_write(&wblock->notify_lock);
901
902 if (wdriver->shutdown)
903 wdriver->shutdown(to_wmi_device(dev));
904
905 if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
906 dev_warn(dev, "Failed to disable device\n");
907 }
908}
909
910static struct class wmi_bus_class = {
911 .name = "wmi_bus",
912};
913
914static const struct bus_type wmi_bus_type = {
915 .name = "wmi",
916 .dev_groups = wmi_groups,
917 .match = wmi_dev_match,
918 .uevent = wmi_dev_uevent,
919 .probe = wmi_dev_probe,
920 .remove = wmi_dev_remove,
921 .shutdown = wmi_dev_shutdown,
922};
923
924static const struct device_type wmi_type_event = {
925 .name = "event",
926 .groups = wmi_event_groups,
927 .release = wmi_dev_release,
928};
929
930static const struct device_type wmi_type_method = {
931 .name = "method",
932 .groups = wmi_method_groups,
933 .release = wmi_dev_release,
934};
935
936static const struct device_type wmi_type_data = {
937 .name = "data",
938 .groups = wmi_data_groups,
939 .release = wmi_dev_release,
940};
941
942static int wmi_count_guids(struct device *dev, void *data)
943{
944 struct wmi_guid_count_context *context = data;
945 struct wmi_block *wblock = dev_to_wblock(dev);
946
947 if (guid_equal(&wblock->gblock.guid, context->guid))
948 context->count++;
949
950 return 0;
951}
952
953static int guid_count(const guid_t *guid)
954{
955 struct wmi_guid_count_context context = {
956 .guid = guid,
957 .count = 0,
958 };
959 int ret;
960
961 ret = bus_for_each_dev(&wmi_bus_type, NULL, &context, wmi_count_guids);
962 if (ret < 0)
963 return ret;
964
965 return context.count;
966}
967
968static int wmi_create_device(struct device *wmi_bus_dev,
969 struct wmi_block *wblock,
970 struct acpi_device *device)
971{
972 char method[WMI_ACPI_METHOD_NAME_SIZE];
973 struct acpi_device_info *info;
974 acpi_handle method_handle;
975 acpi_status status;
976 int count;
977
978 if (wblock->gblock.flags & ACPI_WMI_EVENT) {
979 wblock->dev.dev.type = &wmi_type_event;
980 goto out_init;
981 }
982
983 if (wblock->gblock.flags & ACPI_WMI_METHOD) {
984 get_acpi_method_name(wblock, 'M', method);
985 if (!acpi_has_method(device->handle, method)) {
986 dev_warn(wmi_bus_dev,
987 FW_BUG "%s method block execution control method not found\n",
988 method);
989
990 return -ENXIO;
991 }
992
993 wblock->dev.dev.type = &wmi_type_method;
994 goto out_init;
995 }
996
997 /*
998 * Data Block Query Control Method (WQxx by convention) is
999 * required per the WMI documentation. If it is not present,
1000 * we ignore this data block.
1001 */
1002 get_acpi_method_name(wblock, 'Q', method);
1003 status = acpi_get_handle(device->handle, method, &method_handle);
1004 if (ACPI_FAILURE(status)) {
1005 dev_warn(wmi_bus_dev,
1006 FW_BUG "%s data block query control method not found\n",
1007 method);
1008
1009 return -ENXIO;
1010 }
1011
1012 status = acpi_get_object_info(method_handle, &info);
1013 if (ACPI_FAILURE(status))
1014 return -EIO;
1015
1016 wblock->dev.dev.type = &wmi_type_data;
1017
1018 /*
1019 * The Microsoft documentation specifically states:
1020 *
1021 * Data blocks registered with only a single instance
1022 * can ignore the parameter.
1023 *
1024 * ACPICA will get mad at us if we call the method with the wrong number
1025 * of arguments, so check what our method expects. (On some Dell
1026 * laptops, WQxx may not be a method at all.)
1027 */
1028 if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1029 set_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags);
1030
1031 kfree(info);
1032
1033 get_acpi_method_name(wblock, 'S', method);
1034 if (acpi_has_method(device->handle, method))
1035 wblock->dev.setable = true;
1036
1037 out_init:
1038 init_rwsem(&wblock->notify_lock);
1039 wblock->driver_ready = false;
1040 wblock->dev.dev.bus = &wmi_bus_type;
1041 wblock->dev.dev.parent = wmi_bus_dev;
1042
1043 count = guid_count(&wblock->gblock.guid);
1044 if (count < 0)
1045 return count;
1046
1047 if (count) {
1048 dev_set_name(&wblock->dev.dev, "%pUL-%d", &wblock->gblock.guid, count);
1049 set_bit(WMI_GUID_DUPLICATED, &wblock->flags);
1050 } else {
1051 dev_set_name(&wblock->dev.dev, "%pUL", &wblock->gblock.guid);
1052 }
1053
1054 device_initialize(&wblock->dev.dev);
1055
1056 return 0;
1057}
1058
1059static int wmi_add_device(struct platform_device *pdev, struct wmi_device *wdev)
1060{
1061 struct device_link *link;
1062
1063 /*
1064 * Many aggregate WMI drivers do not use -EPROBE_DEFER when they
1065 * are unable to find a WMI device during probe, instead they require
1066 * all WMI devices associated with an platform device to become available
1067 * at once. This device link thus prevents WMI drivers from probing until
1068 * the associated platform device has finished probing (and has registered
1069 * all discovered WMI devices).
1070 */
1071
1072 link = device_link_add(&wdev->dev, &pdev->dev, DL_FLAG_AUTOREMOVE_SUPPLIER);
1073 if (!link)
1074 return -EINVAL;
1075
1076 return device_add(&wdev->dev);
1077}
1078
1079/*
1080 * Parse the _WDG method for the GUID data blocks
1081 */
1082static int parse_wdg(struct device *wmi_bus_dev, struct platform_device *pdev)
1083{
1084 struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
1085 struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1086 const struct guid_block *gblock;
1087 bool event_data_available;
1088 struct wmi_block *wblock;
1089 union acpi_object *obj;
1090 acpi_status status;
1091 u32 i, total;
1092 int retval;
1093
1094 status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1095 if (ACPI_FAILURE(status))
1096 return -ENXIO;
1097
1098 obj = out.pointer;
1099 if (!obj)
1100 return -ENXIO;
1101
1102 if (obj->type != ACPI_TYPE_BUFFER) {
1103 kfree(obj);
1104 return -ENXIO;
1105 }
1106
1107 event_data_available = acpi_has_method(device->handle, "_WED");
1108 gblock = (const struct guid_block *)obj->buffer.pointer;
1109 total = obj->buffer.length / sizeof(struct guid_block);
1110
1111 for (i = 0; i < total; i++) {
1112 if (!gblock[i].instance_count) {
1113 dev_info(wmi_bus_dev, FW_INFO "%pUL has zero instances\n", &gblock[i].guid);
1114 continue;
1115 }
1116
1117 wblock = kzalloc(sizeof(*wblock), GFP_KERNEL);
1118 if (!wblock)
1119 continue;
1120
1121 wblock->acpi_device = device;
1122 wblock->gblock = gblock[i];
1123 if (gblock[i].flags & ACPI_WMI_EVENT && !event_data_available)
1124 set_bit(WMI_NO_EVENT_DATA, &wblock->flags);
1125
1126 retval = wmi_create_device(wmi_bus_dev, wblock, device);
1127 if (retval) {
1128 kfree(wblock);
1129 continue;
1130 }
1131
1132 retval = wmi_add_device(pdev, &wblock->dev);
1133 if (retval) {
1134 dev_err(wmi_bus_dev, "failed to register %pUL\n",
1135 &wblock->gblock.guid);
1136
1137 put_device(&wblock->dev.dev);
1138 }
1139 }
1140
1141 kfree(obj);
1142
1143 return 0;
1144}
1145
1146static int wmi_get_notify_data(struct wmi_block *wblock, union acpi_object **obj)
1147{
1148 struct acpi_buffer data = { ACPI_ALLOCATE_BUFFER, NULL };
1149 union acpi_object param = {
1150 .integer = {
1151 .type = ACPI_TYPE_INTEGER,
1152 .value = wblock->gblock.notify_id,
1153 }
1154 };
1155 struct acpi_object_list input = {
1156 .count = 1,
1157 .pointer = ¶m,
1158 };
1159 acpi_status status;
1160
1161 status = acpi_evaluate_object(wblock->acpi_device->handle, "_WED", &input, &data);
1162 if (ACPI_FAILURE(status)) {
1163 dev_warn(&wblock->dev.dev, "Failed to get event data\n");
1164 return -EIO;
1165 }
1166
1167 *obj = data.pointer;
1168
1169 return 0;
1170}
1171
1172static void wmi_notify_driver(struct wmi_block *wblock, union acpi_object *obj)
1173{
1174 struct wmi_driver *driver = to_wmi_driver(wblock->dev.dev.driver);
1175
1176 if (!obj && !driver->no_notify_data) {
1177 dev_warn(&wblock->dev.dev, "Event contains no event data\n");
1178 return;
1179 }
1180
1181 if (driver->notify)
1182 driver->notify(&wblock->dev, obj);
1183}
1184
1185static int wmi_notify_device(struct device *dev, void *data)
1186{
1187 struct wmi_block *wblock = dev_to_wblock(dev);
1188 union acpi_object *obj = NULL;
1189 u32 *event = data;
1190 int ret;
1191
1192 if (!(wblock->gblock.flags & ACPI_WMI_EVENT && wblock->gblock.notify_id == *event))
1193 return 0;
1194
1195 /* The ACPI WMI specification says that _WED should be
1196 * evaluated every time an notification is received, even
1197 * if no consumers are present.
1198 *
1199 * Some firmware implementations actually depend on this
1200 * by using a queue for events which will fill up if the
1201 * WMI driver core stops evaluating _WED due to missing
1202 * WMI event consumers.
1203 */
1204 if (!test_bit(WMI_NO_EVENT_DATA, &wblock->flags)) {
1205 ret = wmi_get_notify_data(wblock, &obj);
1206 if (ret < 0)
1207 return -EIO;
1208 }
1209
1210 down_read(&wblock->notify_lock);
1211
1212 if (wblock->dev.dev.driver && wblock->driver_ready)
1213 wmi_notify_driver(wblock, obj);
1214
1215 if (wblock->handler)
1216 wblock->handler(obj, wblock->handler_data);
1217
1218 up_read(&wblock->notify_lock);
1219
1220 kfree(obj);
1221
1222 acpi_bus_generate_netlink_event("wmi", acpi_dev_name(wblock->acpi_device), *event, 0);
1223
1224 return -EBUSY;
1225}
1226
1227static void acpi_wmi_notify_handler(acpi_handle handle, u32 event, void *context)
1228{
1229 struct device *wmi_bus_dev = context;
1230
1231 device_for_each_child(wmi_bus_dev, &event, wmi_notify_device);
1232}
1233
1234static int wmi_remove_device(struct device *dev, void *data)
1235{
1236 device_unregister(dev);
1237
1238 return 0;
1239}
1240
1241static void acpi_wmi_remove(struct platform_device *device)
1242{
1243 struct device *wmi_bus_device = dev_get_drvdata(&device->dev);
1244
1245 device_for_each_child_reverse(wmi_bus_device, NULL, wmi_remove_device);
1246}
1247
1248static void acpi_wmi_remove_notify_handler(void *data)
1249{
1250 struct acpi_device *acpi_device = data;
1251
1252 acpi_remove_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY, acpi_wmi_notify_handler);
1253}
1254
1255static void acpi_wmi_remove_bus_device(void *data)
1256{
1257 struct device *wmi_bus_dev = data;
1258
1259 device_unregister(wmi_bus_dev);
1260}
1261
1262static int acpi_wmi_probe(struct platform_device *device)
1263{
1264 struct acpi_device *acpi_device;
1265 struct device *wmi_bus_dev;
1266 acpi_status status;
1267 int error;
1268
1269 acpi_device = ACPI_COMPANION(&device->dev);
1270 if (!acpi_device) {
1271 dev_err(&device->dev, "ACPI companion is missing\n");
1272 return -ENODEV;
1273 }
1274
1275 wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0), NULL, "wmi_bus-%s",
1276 dev_name(&device->dev));
1277 if (IS_ERR(wmi_bus_dev))
1278 return PTR_ERR(wmi_bus_dev);
1279
1280 error = devm_add_action_or_reset(&device->dev, acpi_wmi_remove_bus_device, wmi_bus_dev);
1281 if (error < 0)
1282 return error;
1283
1284 dev_set_drvdata(&device->dev, wmi_bus_dev);
1285
1286 status = acpi_install_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY,
1287 acpi_wmi_notify_handler, wmi_bus_dev);
1288 if (ACPI_FAILURE(status)) {
1289 dev_err(&device->dev, "Error installing notify handler\n");
1290 return -ENODEV;
1291 }
1292 error = devm_add_action_or_reset(&device->dev, acpi_wmi_remove_notify_handler,
1293 acpi_device);
1294 if (error < 0)
1295 return error;
1296
1297 error = parse_wdg(wmi_bus_dev, device);
1298 if (error) {
1299 dev_err(&device->dev, "Failed to parse _WDG method\n");
1300 return error;
1301 }
1302
1303 return 0;
1304}
1305
1306int __must_check __wmi_driver_register(struct wmi_driver *driver,
1307 struct module *owner)
1308{
1309 driver->driver.owner = owner;
1310 driver->driver.bus = &wmi_bus_type;
1311
1312 return driver_register(&driver->driver);
1313}
1314EXPORT_SYMBOL(__wmi_driver_register);
1315
1316/**
1317 * wmi_driver_unregister() - Unregister a WMI driver
1318 * @driver: WMI driver to unregister
1319 *
1320 * Unregisters a WMI driver from the WMI bus.
1321 */
1322void wmi_driver_unregister(struct wmi_driver *driver)
1323{
1324 driver_unregister(&driver->driver);
1325}
1326EXPORT_SYMBOL(wmi_driver_unregister);
1327
1328static struct platform_driver acpi_wmi_driver = {
1329 .driver = {
1330 .name = "acpi-wmi",
1331 .acpi_match_table = wmi_device_ids,
1332 },
1333 .probe = acpi_wmi_probe,
1334 .remove = acpi_wmi_remove,
1335};
1336
1337static int __init acpi_wmi_init(void)
1338{
1339 int error;
1340
1341 if (acpi_disabled)
1342 return -ENODEV;
1343
1344 error = class_register(&wmi_bus_class);
1345 if (error)
1346 return error;
1347
1348 error = bus_register(&wmi_bus_type);
1349 if (error)
1350 goto err_unreg_class;
1351
1352 error = platform_driver_register(&acpi_wmi_driver);
1353 if (error) {
1354 pr_err("Error loading mapper\n");
1355 goto err_unreg_bus;
1356 }
1357
1358 return 0;
1359
1360err_unreg_bus:
1361 bus_unregister(&wmi_bus_type);
1362
1363err_unreg_class:
1364 class_unregister(&wmi_bus_class);
1365
1366 return error;
1367}
1368
1369static void __exit acpi_wmi_exit(void)
1370{
1371 platform_driver_unregister(&acpi_wmi_driver);
1372 bus_unregister(&wmi_bus_type);
1373 class_unregister(&wmi_bus_class);
1374}
1375
1376subsys_initcall_sync(acpi_wmi_init);
1377module_exit(acpi_wmi_exit);