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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 <[email protected]>
6 *
7 * GUID parsing code from ldm.c is:
8 * Copyright (C) 2001,2002 Richard Russon <[email protected]>
9 * Copyright (c) 2001-2007 Anton Altaparmakov
10 * Copyright (C) 2001,2002 Jakob Kemi <[email protected]>
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/idr.h>
24#include <linux/init.h>
25#include <linux/kernel.h>
26#include <linux/limits.h>
27#include <linux/module.h>
28#include <linux/platform_device.h>
29#include <linux/rwsem.h>
30#include <linux/slab.h>
31#include <linux/sysfs.h>
32#include <linux/types.h>
33#include <linux/uuid.h>
34#include <linux/wmi.h>
35#include <linux/fs.h>
36
37#include "internal.h"
38
39MODULE_AUTHOR("Carlos Corbacho");
40MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
41MODULE_LICENSE("GPL");
42
43struct guid_block {
44 guid_t guid;
45 union {
46 char object_id[2];
47 struct {
48 unsigned char notify_id;
49 unsigned char reserved;
50 };
51 };
52 u8 instance_count;
53 u8 flags;
54} __packed;
55static_assert(sizeof(typeof_member(struct guid_block, guid)) == 16);
56static_assert(sizeof(struct guid_block) == 20);
57static_assert(__alignof__(struct guid_block) == 1);
58
59enum { /* wmi_block flags */
60 WMI_READ_TAKES_NO_ARGS,
61 WMI_GUID_DUPLICATED,
62 WMI_NO_EVENT_DATA,
63};
64
65struct wmi_block {
66 struct wmi_device dev;
67 struct guid_block gblock;
68 struct acpi_device *acpi_device;
69 struct rw_semaphore notify_lock; /* Protects notify callback add/remove */
70 wmi_notify_handler handler;
71 void *handler_data;
72 bool driver_ready;
73 unsigned long flags;
74};
75
76struct wmi_guid_count_context {
77 const guid_t *guid;
78 int count;
79};
80
81static DEFINE_IDA(wmi_ida);
82
83/*
84 * If the GUID data block is marked as expensive, we must enable and
85 * explicitily disable data collection.
86 */
87#define ACPI_WMI_EXPENSIVE BIT(0)
88#define ACPI_WMI_METHOD BIT(1) /* GUID is a method */
89#define ACPI_WMI_STRING BIT(2) /* GUID takes & returns a string */
90#define ACPI_WMI_EVENT BIT(3) /* GUID is an event */
91
92static const struct acpi_device_id wmi_device_ids[] = {
93 {"PNP0C14", 0},
94 {"pnp0c14", 0},
95 { }
96};
97MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
98
99#define dev_to_wblock(__dev) container_of_const(__dev, struct wmi_block, dev.dev)
100
101/*
102 * GUID parsing functions
103 */
104
105static bool guid_parse_and_compare(const char *string, const guid_t *guid)
106{
107 guid_t guid_input;
108
109 if (guid_parse(string, &guid_input))
110 return false;
111
112 return guid_equal(&guid_input, guid);
113}
114
115static const void *find_guid_context(struct wmi_block *wblock,
116 struct wmi_driver *wdriver)
117{
118 const struct wmi_device_id *id;
119
120 id = wdriver->id_table;
121 if (!id)
122 return NULL;
123
124 while (*id->guid_string) {
125 if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid))
126 return id->context;
127 id++;
128 }
129 return NULL;
130}
131
132#define WMI_ACPI_METHOD_NAME_SIZE 5
133
134static inline void get_acpi_method_name(const struct wmi_block *wblock,
135 const char method,
136 char buffer[static WMI_ACPI_METHOD_NAME_SIZE])
137{
138 static_assert(ARRAY_SIZE(wblock->gblock.object_id) == 2);
139 static_assert(WMI_ACPI_METHOD_NAME_SIZE >= 5);
140
141 buffer[0] = 'W';
142 buffer[1] = method;
143 buffer[2] = wblock->gblock.object_id[0];
144 buffer[3] = wblock->gblock.object_id[1];
145 buffer[4] = '\0';
146}
147
148static int wmidev_match_guid(struct device *dev, const void *data)
149{
150 struct wmi_block *wblock = dev_to_wblock(dev);
151 const guid_t *guid = data;
152
153 /* Legacy GUID-based functions are restricted to only see
154 * a single WMI device for each GUID.
155 */
156 if (test_bit(WMI_GUID_DUPLICATED, &wblock->flags))
157 return 0;
158
159 if (guid_equal(guid, &wblock->gblock.guid))
160 return 1;
161
162 return 0;
163}
164
165static const struct bus_type wmi_bus_type;
166
167static const struct device_type wmi_type_event;
168
169static const struct device_type wmi_type_method;
170
171static int wmi_device_enable(struct wmi_device *wdev, bool enable)
172{
173 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
174 char method[WMI_ACPI_METHOD_NAME_SIZE];
175 acpi_handle handle;
176 acpi_status status;
177
178 if (wblock->dev.dev.type == &wmi_type_method)
179 return 0;
180
181 if (wblock->dev.dev.type == &wmi_type_event) {
182 /*
183 * Windows always enables/disables WMI events, even when they are
184 * not marked as being expensive. We follow this behavior for
185 * compatibility reasons.
186 */
187 snprintf(method, sizeof(method), "WE%02X", wblock->gblock.notify_id);
188 } else {
189 if (!(wblock->gblock.flags & ACPI_WMI_EXPENSIVE))
190 return 0;
191
192 get_acpi_method_name(wblock, 'C', method);
193 }
194
195 /*
196 * Not all WMI devices marked as expensive actually implement the
197 * necessary ACPI method. Ignore this missing ACPI method to match
198 * the behaviour of the Windows driver.
199 */
200 status = acpi_get_handle(wblock->acpi_device->handle, method, &handle);
201 if (ACPI_FAILURE(status))
202 return 0;
203
204 status = acpi_execute_simple_method(handle, NULL, enable);
205 if (ACPI_FAILURE(status))
206 return -EIO;
207
208 return 0;
209}
210
211static struct wmi_device *wmi_find_device_by_guid(const char *guid_string)
212{
213 struct device *dev;
214 guid_t guid;
215 int ret;
216
217 ret = guid_parse(guid_string, &guid);
218 if (ret < 0)
219 return ERR_PTR(ret);
220
221 dev = bus_find_device(&wmi_bus_type, NULL, &guid, wmidev_match_guid);
222 if (!dev)
223 return ERR_PTR(-ENODEV);
224
225 return to_wmi_device(dev);
226}
227
228static void wmi_device_put(struct wmi_device *wdev)
229{
230 put_device(&wdev->dev);
231}
232
233/*
234 * Exported WMI functions
235 */
236
237/**
238 * wmi_instance_count - Get number of WMI object instances
239 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
240 *
241 * Get the number of WMI object instances.
242 *
243 * Returns: Number of WMI object instances or negative error code.
244 */
245int wmi_instance_count(const char *guid_string)
246{
247 struct wmi_device *wdev;
248 int ret;
249
250 wdev = wmi_find_device_by_guid(guid_string);
251 if (IS_ERR(wdev))
252 return PTR_ERR(wdev);
253
254 ret = wmidev_instance_count(wdev);
255 wmi_device_put(wdev);
256
257 return ret;
258}
259EXPORT_SYMBOL_GPL(wmi_instance_count);
260
261/**
262 * wmidev_instance_count - Get number of WMI object instances
263 * @wdev: A wmi bus device from a driver
264 *
265 * Get the number of WMI object instances.
266 *
267 * Returns: Number of WMI object instances.
268 */
269u8 wmidev_instance_count(struct wmi_device *wdev)
270{
271 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
272
273 return wblock->gblock.instance_count;
274}
275EXPORT_SYMBOL_GPL(wmidev_instance_count);
276
277/**
278 * wmi_evaluate_method - Evaluate a WMI method (deprecated)
279 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
280 * @instance: Instance index
281 * @method_id: Method ID to call
282 * @in: Mandatory buffer containing input for the method call
283 * @out: Empty buffer to return the method results
284 *
285 * Call an ACPI-WMI method, the caller must free @out.
286 *
287 * Return: acpi_status signaling success or error.
288 */
289acpi_status wmi_evaluate_method(const char *guid_string, u8 instance, u32 method_id,
290 const struct acpi_buffer *in, struct acpi_buffer *out)
291{
292 struct wmi_device *wdev;
293 acpi_status status;
294
295 wdev = wmi_find_device_by_guid(guid_string);
296 if (IS_ERR(wdev))
297 return AE_ERROR;
298
299 status = wmidev_evaluate_method(wdev, instance, method_id, in, out);
300
301 wmi_device_put(wdev);
302
303 return status;
304}
305EXPORT_SYMBOL_GPL(wmi_evaluate_method);
306
307/**
308 * wmidev_evaluate_method - Evaluate a WMI method (deprecated)
309 * @wdev: A wmi bus device from a driver
310 * @instance: Instance index
311 * @method_id: Method ID to call
312 * @in: Mandatory buffer containing input for the method call
313 * @out: Empty buffer to return the method results
314 *
315 * Call an ACPI-WMI method, the caller must free @out.
316 *
317 * Return: acpi_status signaling success or error.
318 */
319acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance, u32 method_id,
320 const struct acpi_buffer *in, struct acpi_buffer *out)
321{
322 struct guid_block *block;
323 struct wmi_block *wblock;
324 acpi_handle handle;
325 struct acpi_object_list input;
326 union acpi_object params[3];
327 char method[WMI_ACPI_METHOD_NAME_SIZE];
328
329 wblock = container_of(wdev, struct wmi_block, dev);
330 block = &wblock->gblock;
331 handle = wblock->acpi_device->handle;
332
333 if (!in)
334 return AE_BAD_DATA;
335
336 if (!(block->flags & ACPI_WMI_METHOD))
337 return AE_BAD_DATA;
338
339 if (block->instance_count <= instance)
340 return AE_BAD_PARAMETER;
341
342 input.count = 3;
343 input.pointer = params;
344
345 params[0].type = ACPI_TYPE_INTEGER;
346 params[0].integer.value = instance;
347 params[1].type = ACPI_TYPE_INTEGER;
348 params[1].integer.value = method_id;
349
350 if (wblock->gblock.flags & ACPI_WMI_STRING) {
351 params[2].type = ACPI_TYPE_STRING;
352 params[2].string.length = in->length;
353 params[2].string.pointer = in->pointer;
354 } else {
355 params[2].type = ACPI_TYPE_BUFFER;
356 params[2].buffer.length = in->length;
357 params[2].buffer.pointer = in->pointer;
358 }
359
360 get_acpi_method_name(wblock, 'M', method);
361
362 return acpi_evaluate_object(handle, method, &input, out);
363}
364EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
365
366/**
367 * wmidev_invoke_method - Invoke a WMI method that returns values
368 * @wdev: A wmi bus device from a driver
369 * @instance: Instance index
370 * @method_id: Method ID to call
371 * @in: Mandatory WMI buffer containing input for the method call
372 * @out: Mandatory WMI buffer to return the method results
373 * @min_size: Minimum size of the method result data in bytes
374 *
375 * Invoke a WMI method that returns values, the caller must free the resulting
376 * data inside @out using kfree(). Said data is guaranteed to be aligned on a
377 * 8-byte boundary. Use wmidev_invoke_procedure() for WMI methods that
378 * return no values.
379 *
380 * Return: 0 on success or negative error code on failure.
381 */
382int wmidev_invoke_method(struct wmi_device *wdev, u8 instance, u32 method_id,
383 const struct wmi_buffer *in, struct wmi_buffer *out, size_t min_size)
384{
385 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
386 struct acpi_buffer aout = { ACPI_ALLOCATE_BUFFER, NULL };
387 struct acpi_buffer ain;
388 union acpi_object *obj;
389 acpi_status status;
390 int ret;
391
392 if (wblock->gblock.flags & ACPI_WMI_STRING) {
393 ret = wmi_marshal_string(in, &ain);
394 if (ret < 0)
395 return ret;
396 } else {
397 if (in->length > U32_MAX)
398 return -E2BIG;
399
400 ain.length = in->length;
401 ain.pointer = in->data;
402 }
403
404 status = wmidev_evaluate_method(wdev, instance, method_id, &ain, &aout);
405
406 if (wblock->gblock.flags & ACPI_WMI_STRING)
407 kfree(ain.pointer);
408
409 if (ACPI_FAILURE(status))
410 return -EIO;
411
412 obj = aout.pointer;
413 if (!obj) {
414 if (min_size != 0)
415 return -ENOMSG;
416
417 out->length = 0;
418 out->data = ZERO_SIZE_PTR;
419
420 return 0;
421 }
422
423 ret = wmi_unmarshal_acpi_object(obj, out, min_size);
424 kfree(obj);
425
426 return ret;
427}
428EXPORT_SYMBOL_GPL(wmidev_invoke_method);
429
430/**
431 * wmidev_invoke_procedure - Invoke a WMI method that does not return values
432 * @wdev: A wmi bus device from a driver
433 * @instance: Instance index
434 * @method_id: Method ID to call
435 * @in: Mandatory WMI buffer containing input for the method call
436 *
437 * Invoke a WMI method that does not return any values. Use wmidev_invoke_method()
438 * for WMI methods that do return values.
439 *
440 * Return: 0 on success or negative error code on failure.
441 */
442int wmidev_invoke_procedure(struct wmi_device *wdev, u8 instance, u32 method_id,
443 const struct wmi_buffer *in)
444{
445 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
446 struct acpi_buffer ain;
447 acpi_status status;
448 int ret;
449
450 if (wblock->gblock.flags & ACPI_WMI_STRING) {
451 ret = wmi_marshal_string(in, &ain);
452 if (ret < 0)
453 return ret;
454 } else {
455 if (in->length > U32_MAX)
456 return -E2BIG;
457
458 ain.length = in->length;
459 ain.pointer = in->data;
460 }
461
462 status = wmidev_evaluate_method(wdev, instance, method_id, &ain, NULL);
463
464 if (wblock->gblock.flags & ACPI_WMI_STRING)
465 kfree(ain.pointer);
466
467 if (ACPI_FAILURE(status))
468 return -EIO;
469
470 return 0;
471}
472EXPORT_SYMBOL_GPL(wmidev_invoke_procedure);
473
474static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
475 struct acpi_buffer *out)
476{
477 struct guid_block *block;
478 acpi_handle handle;
479 struct acpi_object_list input;
480 union acpi_object wq_params[1];
481 char method[WMI_ACPI_METHOD_NAME_SIZE];
482
483 if (!out)
484 return AE_BAD_PARAMETER;
485
486 block = &wblock->gblock;
487 handle = wblock->acpi_device->handle;
488
489 if (block->instance_count <= instance)
490 return AE_BAD_PARAMETER;
491
492 /* Check GUID is a data block */
493 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
494 return AE_ERROR;
495
496 input.count = 1;
497 input.pointer = wq_params;
498 wq_params[0].type = ACPI_TYPE_INTEGER;
499 wq_params[0].integer.value = instance;
500
501 if (instance == 0 && test_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags))
502 input.count = 0;
503
504 get_acpi_method_name(wblock, 'Q', method);
505
506 return acpi_evaluate_object(handle, method, &input, out);
507}
508
509/**
510 * wmi_query_block - Return contents of a WMI block (deprecated)
511 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
512 * @instance: Instance index
513 * @out: Empty buffer to return the contents of the data block to
514 *
515 * Query a ACPI-WMI block, the caller must free @out.
516 *
517 * Return: ACPI object containing the content of the WMI block.
518 */
519acpi_status wmi_query_block(const char *guid_string, u8 instance,
520 struct acpi_buffer *out)
521{
522 struct wmi_block *wblock;
523 struct wmi_device *wdev;
524 acpi_status status;
525
526 wdev = wmi_find_device_by_guid(guid_string);
527 if (IS_ERR(wdev))
528 return AE_ERROR;
529
530 if (wmi_device_enable(wdev, true) < 0)
531 dev_warn(&wdev->dev, "Failed to enable device\n");
532
533 wblock = container_of(wdev, struct wmi_block, dev);
534 status = __query_block(wblock, instance, out);
535
536 if (wmi_device_enable(wdev, false) < 0)
537 dev_warn(&wdev->dev, "Failed to disable device\n");
538
539 wmi_device_put(wdev);
540
541 return status;
542}
543EXPORT_SYMBOL_GPL(wmi_query_block);
544
545/**
546 * wmidev_block_query - Return contents of a WMI block (deprectated)
547 * @wdev: A wmi bus device from a driver
548 * @instance: Instance index
549 *
550 * Query an ACPI-WMI block, the caller must free the result.
551 *
552 * Return: ACPI object containing the content of the WMI block.
553 */
554union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
555{
556 struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
557 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
558
559 if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
560 return NULL;
561
562 return out.pointer;
563}
564EXPORT_SYMBOL_GPL(wmidev_block_query);
565
566/**
567 * wmidev_query_block - Return contents of a WMI data block
568 * @wdev: A wmi bus device from a driver
569 * @instance: Instance index
570 * @out: WMI buffer to fill
571 * @min_size: Minimum size of the result data in bytes
572 *
573 * Query a WMI data block, the caller must free the resulting data inside @out
574 * using kfree(). Said data is guaranteed to be aligned on a 8-byte boundary.
575 *
576 * Return: 0 on success or a negative error code on failure.
577 */
578int wmidev_query_block(struct wmi_device *wdev, u8 instance, struct wmi_buffer *out,
579 size_t min_size)
580{
581 union acpi_object *obj;
582 int ret;
583
584 obj = wmidev_block_query(wdev, instance);
585 if (!obj)
586 return -EIO;
587
588 ret = wmi_unmarshal_acpi_object(obj, out, min_size);
589 kfree(obj);
590
591 return ret;
592}
593EXPORT_SYMBOL_GPL(wmidev_query_block);
594
595/**
596 * wmi_set_block - Write to a WMI block (deprecated)
597 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
598 * @instance: Instance index
599 * @in: Buffer containing new values for the data block
600 *
601 * Write the contents of the input buffer to an ACPI-WMI data block.
602 *
603 * Return: acpi_status signaling success or error.
604 */
605acpi_status wmi_set_block(const char *guid_string, u8 instance, const struct acpi_buffer *in)
606{
607 struct wmi_device *wdev;
608 acpi_status status;
609
610 wdev = wmi_find_device_by_guid(guid_string);
611 if (IS_ERR(wdev))
612 return AE_ERROR;
613
614 if (wmi_device_enable(wdev, true) < 0)
615 dev_warn(&wdev->dev, "Failed to enable device\n");
616
617 status = wmidev_block_set(wdev, instance, in);
618
619 if (wmi_device_enable(wdev, false) < 0)
620 dev_warn(&wdev->dev, "Failed to disable device\n");
621
622 wmi_device_put(wdev);
623
624 return status;
625}
626EXPORT_SYMBOL_GPL(wmi_set_block);
627
628/**
629 * wmidev_block_set - Write to a WMI block (deprecated)
630 * @wdev: A wmi bus device from a driver
631 * @instance: Instance index
632 * @in: Buffer containing new values for the data block
633 *
634 * Write contents of the input buffer to an ACPI-WMI data block.
635 *
636 * Return: acpi_status signaling success or error.
637 */
638acpi_status wmidev_block_set(struct wmi_device *wdev, u8 instance, const struct acpi_buffer *in)
639{
640 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
641 acpi_handle handle = wblock->acpi_device->handle;
642 struct guid_block *block = &wblock->gblock;
643 char method[WMI_ACPI_METHOD_NAME_SIZE];
644 struct acpi_object_list input;
645 union acpi_object params[2];
646
647 if (!in)
648 return AE_BAD_DATA;
649
650 if (block->instance_count <= instance)
651 return AE_BAD_PARAMETER;
652
653 /* Check GUID is a data block */
654 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
655 return AE_ERROR;
656
657 input.count = 2;
658 input.pointer = params;
659 params[0].type = ACPI_TYPE_INTEGER;
660 params[0].integer.value = instance;
661
662 if (wblock->gblock.flags & ACPI_WMI_STRING) {
663 params[1].type = ACPI_TYPE_STRING;
664 params[1].string.length = in->length;
665 params[1].string.pointer = in->pointer;
666 } else {
667 params[1].type = ACPI_TYPE_BUFFER;
668 params[1].buffer.length = in->length;
669 params[1].buffer.pointer = in->pointer;
670 }
671
672 get_acpi_method_name(wblock, 'S', method);
673
674 return acpi_evaluate_object(handle, method, &input, NULL);
675}
676EXPORT_SYMBOL_GPL(wmidev_block_set);
677
678/**
679 * wmidev_set_block - Write to a WMI data block
680 * @wdev: A wmi bus device from a driver
681 * @instance: Instance index
682 * @in: WMI buffer containing new values for the data block
683 *
684 * Write the content of @in into a WMI data block.
685 *
686 * Return: 0 on success or negative error code on failure.
687 */
688int wmidev_set_block(struct wmi_device *wdev, u8 instance, const struct wmi_buffer *in)
689{
690 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
691 struct acpi_buffer buffer;
692 acpi_status status;
693 int ret;
694
695 if (wblock->gblock.flags & ACPI_WMI_STRING) {
696 ret = wmi_marshal_string(in, &buffer);
697 if (ret < 0)
698 return ret;
699 } else {
700 if (in->length > U32_MAX)
701 return -E2BIG;
702
703 buffer.length = in->length;
704 buffer.pointer = in->data;
705 }
706
707 status = wmidev_block_set(wdev, instance, &buffer);
708 if (wblock->gblock.flags & ACPI_WMI_STRING)
709 kfree(buffer.pointer);
710
711 if (ACPI_FAILURE(status))
712 return -EIO;
713
714 return 0;
715}
716EXPORT_SYMBOL_GPL(wmidev_set_block);
717
718/**
719 * wmi_install_notify_handler - Register handler for WMI events (deprecated)
720 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
721 * @handler: Function to handle notifications
722 * @data: Data to be returned to handler when event is fired
723 *
724 * Register a handler for events sent to the ACPI-WMI mapper device.
725 *
726 * Return: acpi_status signaling success or error.
727 */
728acpi_status wmi_install_notify_handler(const char *guid,
729 wmi_notify_handler handler,
730 void *data)
731{
732 struct wmi_block *wblock;
733 struct wmi_device *wdev;
734 acpi_status status;
735
736 wdev = wmi_find_device_by_guid(guid);
737 if (IS_ERR(wdev))
738 return AE_ERROR;
739
740 wblock = container_of(wdev, struct wmi_block, dev);
741
742 down_write(&wblock->notify_lock);
743 if (wblock->handler) {
744 status = AE_ALREADY_ACQUIRED;
745 } else {
746 wblock->handler = handler;
747 wblock->handler_data = data;
748
749 if (wmi_device_enable(wdev, true) < 0)
750 dev_warn(&wblock->dev.dev, "Failed to enable device\n");
751
752 status = AE_OK;
753 }
754 up_write(&wblock->notify_lock);
755
756 wmi_device_put(wdev);
757
758 return status;
759}
760EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
761
762/**
763 * wmi_remove_notify_handler - Unregister handler for WMI events (deprecated)
764 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
765 *
766 * Unregister handler for events sent to the ACPI-WMI mapper device.
767 *
768 * Return: acpi_status signaling success or error.
769 */
770acpi_status wmi_remove_notify_handler(const char *guid)
771{
772 struct wmi_block *wblock;
773 struct wmi_device *wdev;
774 acpi_status status;
775
776 wdev = wmi_find_device_by_guid(guid);
777 if (IS_ERR(wdev))
778 return AE_ERROR;
779
780 wblock = container_of(wdev, struct wmi_block, dev);
781
782 down_write(&wblock->notify_lock);
783 if (!wblock->handler) {
784 status = AE_NULL_ENTRY;
785 } else {
786 if (wmi_device_enable(wdev, false) < 0)
787 dev_warn(&wblock->dev.dev, "Failed to disable device\n");
788
789 wblock->handler = NULL;
790 wblock->handler_data = NULL;
791
792 status = AE_OK;
793 }
794 up_write(&wblock->notify_lock);
795
796 wmi_device_put(wdev);
797
798 return status;
799}
800EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
801
802/**
803 * wmi_has_guid - Check if a GUID is available
804 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
805 *
806 * Check if a given GUID is defined by _WDG.
807 *
808 * Return: True if GUID is available, false otherwise.
809 */
810bool wmi_has_guid(const char *guid_string)
811{
812 struct wmi_device *wdev;
813
814 wdev = wmi_find_device_by_guid(guid_string);
815 if (IS_ERR(wdev))
816 return false;
817
818 wmi_device_put(wdev);
819
820 return true;
821}
822EXPORT_SYMBOL_GPL(wmi_has_guid);
823
824/**
825 * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID (deprecated)
826 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
827 *
828 * Find the _UID of ACPI device associated with this WMI GUID.
829 *
830 * Return: The ACPI _UID field value or NULL if the WMI GUID was not found.
831 */
832char *wmi_get_acpi_device_uid(const char *guid_string)
833{
834 struct wmi_block *wblock;
835 struct wmi_device *wdev;
836 char *uid;
837
838 wdev = wmi_find_device_by_guid(guid_string);
839 if (IS_ERR(wdev))
840 return NULL;
841
842 wblock = container_of(wdev, struct wmi_block, dev);
843 uid = acpi_device_uid(wblock->acpi_device);
844
845 wmi_device_put(wdev);
846
847 return uid;
848}
849EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
850
851/*
852 * sysfs interface
853 */
854static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
855 char *buf)
856{
857 struct wmi_block *wblock = dev_to_wblock(dev);
858
859 return sysfs_emit(buf, "wmi:%pUL\n", &wblock->gblock.guid);
860}
861
862static const DEVICE_ATTR_RO(modalias);
863
864static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
865 char *buf)
866{
867 struct wmi_block *wblock = dev_to_wblock(dev);
868
869 return sysfs_emit(buf, "%pUL\n", &wblock->gblock.guid);
870}
871
872static const DEVICE_ATTR_RO(guid);
873
874static ssize_t instance_count_show(struct device *dev,
875 struct device_attribute *attr, char *buf)
876{
877 struct wmi_block *wblock = dev_to_wblock(dev);
878
879 return sysfs_emit(buf, "%d\n", (int)wblock->gblock.instance_count);
880}
881
882static const DEVICE_ATTR_RO(instance_count);
883
884static ssize_t expensive_show(struct device *dev,
885 struct device_attribute *attr, char *buf)
886{
887 struct wmi_block *wblock = dev_to_wblock(dev);
888
889 return sysfs_emit(buf, "%d\n",
890 (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
891}
892
893static const DEVICE_ATTR_RO(expensive);
894
895static const struct attribute * const wmi_attrs[] = {
896 &dev_attr_modalias.attr,
897 &dev_attr_guid.attr,
898 &dev_attr_instance_count.attr,
899 &dev_attr_expensive.attr,
900 NULL
901};
902ATTRIBUTE_GROUPS(wmi);
903
904static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
905 char *buf)
906{
907 struct wmi_block *wblock = dev_to_wblock(dev);
908
909 return sysfs_emit(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
910}
911
912static const DEVICE_ATTR_RO(notify_id);
913
914static const struct attribute * const wmi_event_attrs[] = {
915 &dev_attr_notify_id.attr,
916 NULL
917};
918ATTRIBUTE_GROUPS(wmi_event);
919
920static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
921 char *buf)
922{
923 struct wmi_block *wblock = dev_to_wblock(dev);
924
925 return sysfs_emit(buf, "%c%c\n", wblock->gblock.object_id[0],
926 wblock->gblock.object_id[1]);
927}
928
929static const DEVICE_ATTR_RO(object_id);
930
931static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
932 char *buf)
933{
934 struct wmi_device *wdev = to_wmi_device(dev);
935
936 return sysfs_emit(buf, "%d\n", (int)wdev->setable);
937}
938
939static const DEVICE_ATTR_RO(setable);
940
941static const struct attribute * const wmi_data_attrs[] = {
942 &dev_attr_object_id.attr,
943 &dev_attr_setable.attr,
944 NULL
945};
946ATTRIBUTE_GROUPS(wmi_data);
947
948static const struct attribute * const wmi_method_attrs[] = {
949 &dev_attr_object_id.attr,
950 NULL
951};
952ATTRIBUTE_GROUPS(wmi_method);
953
954static int wmi_dev_uevent(const struct device *dev, struct kobj_uevent_env *env)
955{
956 const struct wmi_block *wblock = dev_to_wblock(dev);
957
958 if (add_uevent_var(env, "MODALIAS=wmi:%pUL", &wblock->gblock.guid))
959 return -ENOMEM;
960
961 if (add_uevent_var(env, "WMI_GUID=%pUL", &wblock->gblock.guid))
962 return -ENOMEM;
963
964 return 0;
965}
966
967static void wmi_dev_release(struct device *dev)
968{
969 struct wmi_block *wblock = dev_to_wblock(dev);
970
971 kfree(wblock);
972}
973
974static int wmi_dev_match(struct device *dev, const struct device_driver *driver)
975{
976 const struct wmi_driver *wmi_driver = to_wmi_driver(driver);
977 struct wmi_block *wblock = dev_to_wblock(dev);
978 const struct wmi_device_id *id = wmi_driver->id_table;
979 int ret;
980
981 /* When driver_override is set, only bind to the matching driver */
982 ret = device_match_driver_override(dev, driver);
983 if (ret >= 0)
984 return ret;
985
986 if (id == NULL)
987 return 0;
988
989 while (*id->guid_string) {
990 if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid))
991 return 1;
992
993 id++;
994 }
995
996 return 0;
997}
998
999static void wmi_dev_disable(void *data)
1000{
1001 struct device *dev = data;
1002
1003 if (wmi_device_enable(to_wmi_device(dev), false) < 0)
1004 dev_warn(dev, "Failed to disable device\n");
1005}
1006
1007static int wmi_dev_probe(struct device *dev)
1008{
1009 struct wmi_block *wblock = dev_to_wblock(dev);
1010 struct wmi_driver *wdriver = to_wmi_driver(dev->driver);
1011 int ret;
1012
1013 /* Some older WMI drivers will break if instantiated multiple times,
1014 * so they are blocked from probing WMI devices with a duplicated GUID.
1015 *
1016 * New WMI drivers should support being instantiated multiple times.
1017 */
1018 if (test_bit(WMI_GUID_DUPLICATED, &wblock->flags) && !wdriver->no_singleton) {
1019 dev_warn(dev, "Legacy driver %s cannot be instantiated multiple times\n",
1020 dev->driver->name);
1021
1022 return -ENODEV;
1023 }
1024
1025 if (wdriver->notify || wdriver->notify_new) {
1026 if (test_bit(WMI_NO_EVENT_DATA, &wblock->flags) && wdriver->min_event_size)
1027 return -ENODEV;
1028 }
1029
1030 if (wmi_device_enable(to_wmi_device(dev), true) < 0)
1031 dev_warn(dev, "failed to enable device -- probing anyway\n");
1032
1033 /*
1034 * We have to make sure that all devres-managed resources are released first because
1035 * some might still want to access the underlying WMI device.
1036 */
1037 ret = devm_add_action_or_reset(dev, wmi_dev_disable, dev);
1038 if (ret < 0)
1039 return ret;
1040
1041 if (wdriver->probe) {
1042 ret = wdriver->probe(to_wmi_device(dev),
1043 find_guid_context(wblock, wdriver));
1044 if (ret)
1045 return ret;
1046 }
1047
1048 down_write(&wblock->notify_lock);
1049 wblock->driver_ready = true;
1050 up_write(&wblock->notify_lock);
1051
1052 return 0;
1053}
1054
1055static void wmi_dev_remove(struct device *dev)
1056{
1057 struct wmi_block *wblock = dev_to_wblock(dev);
1058 struct wmi_driver *wdriver = to_wmi_driver(dev->driver);
1059
1060 down_write(&wblock->notify_lock);
1061 wblock->driver_ready = false;
1062 up_write(&wblock->notify_lock);
1063
1064 if (wdriver->remove)
1065 wdriver->remove(to_wmi_device(dev));
1066}
1067
1068static void wmi_dev_shutdown(struct device *dev)
1069{
1070 struct wmi_driver *wdriver;
1071 struct wmi_block *wblock;
1072
1073 if (dev->driver) {
1074 wdriver = to_wmi_driver(dev->driver);
1075 wblock = dev_to_wblock(dev);
1076
1077 /*
1078 * Some machines return bogus WMI event data when disabling
1079 * the WMI event. Because of this we must prevent the associated
1080 * WMI driver from receiving new WMI events before disabling it.
1081 */
1082 down_write(&wblock->notify_lock);
1083 wblock->driver_ready = false;
1084 up_write(&wblock->notify_lock);
1085
1086 if (wdriver->shutdown)
1087 wdriver->shutdown(to_wmi_device(dev));
1088
1089 /*
1090 * We still need to disable the WMI device here since devres-managed resources
1091 * like wmi_dev_disable() will not be release during shutdown.
1092 */
1093 if (wmi_device_enable(to_wmi_device(dev), false) < 0)
1094 dev_warn(dev, "Failed to disable device\n");
1095 }
1096}
1097
1098static const struct class wmi_bus_class = {
1099 .name = "wmi_bus",
1100};
1101
1102static const struct bus_type wmi_bus_type = {
1103 .name = "wmi",
1104 .dev_groups = wmi_groups,
1105 .driver_override = true,
1106 .match = wmi_dev_match,
1107 .uevent = wmi_dev_uevent,
1108 .probe = wmi_dev_probe,
1109 .remove = wmi_dev_remove,
1110 .shutdown = wmi_dev_shutdown,
1111};
1112
1113static const struct device_type wmi_type_event = {
1114 .name = "event",
1115 .groups = wmi_event_groups,
1116 .release = wmi_dev_release,
1117};
1118
1119static const struct device_type wmi_type_method = {
1120 .name = "method",
1121 .groups = wmi_method_groups,
1122 .release = wmi_dev_release,
1123};
1124
1125static const struct device_type wmi_type_data = {
1126 .name = "data",
1127 .groups = wmi_data_groups,
1128 .release = wmi_dev_release,
1129};
1130
1131static int wmi_count_guids(struct device *dev, void *data)
1132{
1133 struct wmi_guid_count_context *context = data;
1134 struct wmi_block *wblock = dev_to_wblock(dev);
1135
1136 if (guid_equal(&wblock->gblock.guid, context->guid))
1137 context->count++;
1138
1139 return 0;
1140}
1141
1142static int guid_count(const guid_t *guid)
1143{
1144 struct wmi_guid_count_context context = {
1145 .guid = guid,
1146 .count = 0,
1147 };
1148 int ret;
1149
1150 ret = bus_for_each_dev(&wmi_bus_type, NULL, &context, wmi_count_guids);
1151 if (ret < 0)
1152 return ret;
1153
1154 return context.count;
1155}
1156
1157static int wmi_dev_set_name(struct wmi_block *wblock, int count)
1158{
1159 if (IS_ENABLED(CONFIG_ACPI_WMI_LEGACY_DEVICE_NAMES)) {
1160 if (count)
1161 return dev_set_name(&wblock->dev.dev, "%pUL-%d", &wblock->gblock.guid,
1162 count);
1163 else
1164 return dev_set_name(&wblock->dev.dev, "%pUL", &wblock->gblock.guid);
1165 }
1166
1167 return dev_set_name(&wblock->dev.dev, "%pUL-%d", &wblock->gblock.guid, wblock->dev.dev.id);
1168}
1169
1170static int wmi_create_device(struct device *wmi_bus_dev,
1171 struct wmi_block *wblock,
1172 struct acpi_device *device)
1173{
1174 char method[WMI_ACPI_METHOD_NAME_SIZE];
1175 struct acpi_device_info *info;
1176 acpi_handle method_handle;
1177 acpi_status status;
1178 int count, ret;
1179
1180 if (wblock->gblock.flags & ACPI_WMI_EVENT) {
1181 wblock->dev.dev.type = &wmi_type_event;
1182 goto out_init;
1183 }
1184
1185 if (wblock->gblock.flags & ACPI_WMI_METHOD) {
1186 get_acpi_method_name(wblock, 'M', method);
1187 if (!acpi_has_method(device->handle, method)) {
1188 dev_warn(wmi_bus_dev,
1189 FW_BUG "%s method block execution control method not found\n",
1190 method);
1191
1192 return -ENXIO;
1193 }
1194
1195 wblock->dev.dev.type = &wmi_type_method;
1196 goto out_init;
1197 }
1198
1199 /*
1200 * Data Block Query Control Method (WQxx by convention) is
1201 * required per the WMI documentation. If it is not present,
1202 * we ignore this data block.
1203 */
1204 get_acpi_method_name(wblock, 'Q', method);
1205 status = acpi_get_handle(device->handle, method, &method_handle);
1206 if (ACPI_FAILURE(status)) {
1207 dev_warn(wmi_bus_dev,
1208 FW_BUG "%s data block query control method not found\n",
1209 method);
1210
1211 return -ENXIO;
1212 }
1213
1214 status = acpi_get_object_info(method_handle, &info);
1215 if (ACPI_FAILURE(status))
1216 return -EIO;
1217
1218 wblock->dev.dev.type = &wmi_type_data;
1219
1220 /*
1221 * The Microsoft documentation specifically states:
1222 *
1223 * Data blocks registered with only a single instance
1224 * can ignore the parameter.
1225 *
1226 * ACPICA will get mad at us if we call the method with the wrong number
1227 * of arguments, so check what our method expects. (On some Dell
1228 * laptops, WQxx may not be a method at all.)
1229 */
1230 if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1231 set_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags);
1232
1233 kfree(info);
1234
1235 get_acpi_method_name(wblock, 'S', method);
1236 if (acpi_has_method(device->handle, method))
1237 wblock->dev.setable = true;
1238
1239 out_init:
1240 init_rwsem(&wblock->notify_lock);
1241 wblock->driver_ready = false;
1242 wblock->dev.dev.bus = &wmi_bus_type;
1243 wblock->dev.dev.parent = wmi_bus_dev;
1244
1245 count = guid_count(&wblock->gblock.guid);
1246 if (count < 0)
1247 return count;
1248
1249 if (count)
1250 set_bit(WMI_GUID_DUPLICATED, &wblock->flags);
1251
1252 ret = ida_alloc(&wmi_ida, GFP_KERNEL);
1253 if (ret < 0)
1254 return ret;
1255
1256 wblock->dev.dev.id = ret;
1257 ret = wmi_dev_set_name(wblock, count);
1258 if (ret < 0) {
1259 ida_free(&wmi_ida, wblock->dev.dev.id);
1260 return ret;
1261 }
1262
1263 device_initialize(&wblock->dev.dev);
1264
1265 return 0;
1266}
1267
1268static int wmi_add_device(struct platform_device *pdev, struct wmi_device *wdev)
1269{
1270 struct device_link *link;
1271
1272 /*
1273 * Many aggregate WMI drivers do not use -EPROBE_DEFER when they
1274 * are unable to find a WMI device during probe, instead they require
1275 * all WMI devices associated with an platform device to become available
1276 * at once. This device link thus prevents WMI drivers from probing until
1277 * the associated platform device has finished probing (and has registered
1278 * all discovered WMI devices).
1279 */
1280
1281 link = device_link_add(&wdev->dev, &pdev->dev, DL_FLAG_AUTOREMOVE_SUPPLIER);
1282 if (!link)
1283 return -EINVAL;
1284
1285 return device_add(&wdev->dev);
1286}
1287
1288/*
1289 * Parse the _WDG method for the GUID data blocks
1290 */
1291static int parse_wdg(struct device *wmi_bus_dev, struct platform_device *pdev)
1292{
1293 struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
1294 struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1295 const struct guid_block *gblock;
1296 bool event_data_available;
1297 struct wmi_block *wblock;
1298 union acpi_object *obj;
1299 acpi_status status;
1300 u32 i, total;
1301 int retval;
1302
1303 status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1304 if (ACPI_FAILURE(status))
1305 return -ENXIO;
1306
1307 obj = out.pointer;
1308 if (!obj)
1309 return -ENXIO;
1310
1311 if (obj->type != ACPI_TYPE_BUFFER) {
1312 kfree(obj);
1313 return -ENXIO;
1314 }
1315
1316 event_data_available = acpi_has_method(device->handle, "_WED");
1317 gblock = (const struct guid_block *)obj->buffer.pointer;
1318 total = obj->buffer.length / sizeof(struct guid_block);
1319
1320 for (i = 0; i < total; i++) {
1321 if (!gblock[i].instance_count) {
1322 dev_info(wmi_bus_dev, FW_INFO "%pUL has zero instances\n", &gblock[i].guid);
1323 continue;
1324 }
1325
1326 wblock = kzalloc_obj(*wblock);
1327 if (!wblock)
1328 continue;
1329
1330 wblock->acpi_device = device;
1331 wblock->gblock = gblock[i];
1332 if (gblock[i].flags & ACPI_WMI_EVENT && !event_data_available)
1333 set_bit(WMI_NO_EVENT_DATA, &wblock->flags);
1334
1335 retval = wmi_create_device(wmi_bus_dev, wblock, device);
1336 if (retval) {
1337 kfree(wblock);
1338 continue;
1339 }
1340
1341 retval = wmi_add_device(pdev, &wblock->dev);
1342 if (retval) {
1343 dev_err(wmi_bus_dev, "failed to register %pUL\n",
1344 &wblock->gblock.guid);
1345
1346 ida_free(&wmi_ida, wblock->dev.dev.id);
1347 put_device(&wblock->dev.dev);
1348 }
1349 }
1350
1351 kfree(obj);
1352
1353 return 0;
1354}
1355
1356static int wmi_get_notify_data(struct wmi_block *wblock, union acpi_object **obj)
1357{
1358 struct acpi_buffer data = { ACPI_ALLOCATE_BUFFER, NULL };
1359 union acpi_object param = {
1360 .integer = {
1361 .type = ACPI_TYPE_INTEGER,
1362 .value = wblock->gblock.notify_id,
1363 }
1364 };
1365 struct acpi_object_list input = {
1366 .count = 1,
1367 .pointer = &param,
1368 };
1369 acpi_status status;
1370
1371 status = acpi_evaluate_object(wblock->acpi_device->handle, "_WED", &input, &data);
1372 if (ACPI_FAILURE(status)) {
1373 dev_warn(&wblock->dev.dev, "Failed to get event data\n");
1374 return -EIO;
1375 }
1376
1377 *obj = data.pointer;
1378
1379 return 0;
1380}
1381
1382static void wmi_notify_driver(struct wmi_block *wblock, union acpi_object *obj)
1383{
1384 struct wmi_driver *driver = to_wmi_driver(wblock->dev.dev.driver);
1385 struct wmi_buffer dummy = {
1386 .length = 0,
1387 .data = ZERO_SIZE_PTR,
1388 };
1389 struct wmi_buffer buffer;
1390 int ret;
1391
1392 if (!obj && driver->min_event_size) {
1393 dev_warn(&wblock->dev.dev, "Event contains no event data\n");
1394 return;
1395 }
1396
1397 if (driver->notify)
1398 driver->notify(&wblock->dev, obj);
1399
1400 if (driver->notify_new) {
1401 if (!obj) {
1402 driver->notify_new(&wblock->dev, &dummy);
1403 return;
1404 }
1405
1406 ret = wmi_unmarshal_acpi_object(obj, &buffer, driver->min_event_size);
1407 if (ret < 0) {
1408 dev_warn(&wblock->dev.dev, "Failed to unmarshal event data: %d\n", ret);
1409 return;
1410 }
1411
1412 driver->notify_new(&wblock->dev, &buffer);
1413 kfree(buffer.data);
1414 }
1415}
1416
1417static int wmi_notify_device(struct device *dev, void *data)
1418{
1419 struct wmi_block *wblock = dev_to_wblock(dev);
1420 union acpi_object *obj = NULL;
1421 u32 *event = data;
1422 int ret;
1423
1424 if (!(wblock->gblock.flags & ACPI_WMI_EVENT && wblock->gblock.notify_id == *event))
1425 return 0;
1426
1427 /* The ACPI WMI specification says that _WED should be
1428 * evaluated every time an notification is received, even
1429 * if no consumers are present.
1430 *
1431 * Some firmware implementations actually depend on this
1432 * by using a queue for events which will fill up if the
1433 * WMI driver core stops evaluating _WED due to missing
1434 * WMI event consumers.
1435 */
1436 if (!test_bit(WMI_NO_EVENT_DATA, &wblock->flags)) {
1437 ret = wmi_get_notify_data(wblock, &obj);
1438 if (ret < 0)
1439 return -EIO;
1440 }
1441
1442 down_read(&wblock->notify_lock);
1443
1444 if (wblock->dev.dev.driver && wblock->driver_ready)
1445 wmi_notify_driver(wblock, obj);
1446
1447 if (wblock->handler)
1448 wblock->handler(obj, wblock->handler_data);
1449
1450 up_read(&wblock->notify_lock);
1451
1452 kfree(obj);
1453
1454 acpi_bus_generate_netlink_event("wmi", acpi_dev_name(wblock->acpi_device), *event, 0);
1455
1456 return -EBUSY;
1457}
1458
1459static void acpi_wmi_notify_handler(acpi_handle handle, u32 event, void *context)
1460{
1461 struct device *wmi_bus_dev = context;
1462
1463 device_for_each_child(wmi_bus_dev, &event, wmi_notify_device);
1464}
1465
1466static int wmi_remove_device(struct device *dev, void *data)
1467{
1468 int id = dev->id;
1469
1470 device_unregister(dev);
1471 ida_free(&wmi_ida, id);
1472
1473 return 0;
1474}
1475
1476static void acpi_wmi_remove(struct platform_device *device)
1477{
1478 struct device *wmi_bus_device = dev_get_drvdata(&device->dev);
1479
1480 device_for_each_child_reverse(wmi_bus_device, NULL, wmi_remove_device);
1481}
1482
1483static void acpi_wmi_remove_notify_handler(void *data)
1484{
1485 struct acpi_device *acpi_device = data;
1486
1487 acpi_remove_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY, acpi_wmi_notify_handler);
1488}
1489
1490static void acpi_wmi_remove_bus_device(void *data)
1491{
1492 struct device *wmi_bus_dev = data;
1493
1494 device_unregister(wmi_bus_dev);
1495}
1496
1497static int acpi_wmi_probe(struct platform_device *device)
1498{
1499 struct acpi_device *acpi_device;
1500 struct device *wmi_bus_dev;
1501 acpi_status status;
1502 int error;
1503
1504 acpi_device = ACPI_COMPANION(&device->dev);
1505 if (!acpi_device) {
1506 dev_err(&device->dev, "ACPI companion is missing\n");
1507 return -ENODEV;
1508 }
1509
1510 wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0), NULL, "wmi_bus-%s",
1511 dev_name(&device->dev));
1512 if (IS_ERR(wmi_bus_dev))
1513 return PTR_ERR(wmi_bus_dev);
1514
1515 error = devm_add_action_or_reset(&device->dev, acpi_wmi_remove_bus_device, wmi_bus_dev);
1516 if (error < 0)
1517 return error;
1518
1519 dev_set_drvdata(&device->dev, wmi_bus_dev);
1520
1521 status = acpi_install_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY,
1522 acpi_wmi_notify_handler, wmi_bus_dev);
1523 if (ACPI_FAILURE(status)) {
1524 dev_err(&device->dev, "Error installing notify handler\n");
1525 return -ENODEV;
1526 }
1527 error = devm_add_action_or_reset(&device->dev, acpi_wmi_remove_notify_handler,
1528 acpi_device);
1529 if (error < 0)
1530 return error;
1531
1532 error = parse_wdg(wmi_bus_dev, device);
1533 if (error) {
1534 dev_err(&device->dev, "Failed to parse _WDG method\n");
1535 return error;
1536 }
1537
1538 return 0;
1539}
1540
1541int __must_check __wmi_driver_register(struct wmi_driver *driver,
1542 struct module *owner)
1543{
1544 driver->driver.owner = owner;
1545 driver->driver.bus = &wmi_bus_type;
1546
1547 return driver_register(&driver->driver);
1548}
1549EXPORT_SYMBOL(__wmi_driver_register);
1550
1551/**
1552 * wmi_driver_unregister() - Unregister a WMI driver
1553 * @driver: WMI driver to unregister
1554 *
1555 * Unregisters a WMI driver from the WMI bus.
1556 */
1557void wmi_driver_unregister(struct wmi_driver *driver)
1558{
1559 driver_unregister(&driver->driver);
1560}
1561EXPORT_SYMBOL(wmi_driver_unregister);
1562
1563static struct platform_driver acpi_wmi_driver = {
1564 .driver = {
1565 .name = "acpi-wmi",
1566 .acpi_match_table = wmi_device_ids,
1567 },
1568 .probe = acpi_wmi_probe,
1569 .remove = acpi_wmi_remove,
1570};
1571
1572static int __init acpi_wmi_init(void)
1573{
1574 int error;
1575
1576 if (acpi_disabled)
1577 return -ENODEV;
1578
1579 error = class_register(&wmi_bus_class);
1580 if (error)
1581 return error;
1582
1583 error = bus_register(&wmi_bus_type);
1584 if (error)
1585 goto err_unreg_class;
1586
1587 error = platform_driver_register(&acpi_wmi_driver);
1588 if (error) {
1589 pr_err("Error loading mapper\n");
1590 goto err_unreg_bus;
1591 }
1592
1593 return 0;
1594
1595err_unreg_bus:
1596 bus_unregister(&wmi_bus_type);
1597
1598err_unreg_class:
1599 class_unregister(&wmi_bus_class);
1600
1601 return error;
1602}
1603
1604static void __exit acpi_wmi_exit(void)
1605{
1606 platform_driver_unregister(&acpi_wmi_driver);
1607 bus_unregister(&wmi_bus_type);
1608 class_unregister(&wmi_bus_class);
1609}
1610
1611subsys_initcall_sync(acpi_wmi_init);
1612module_exit(acpi_wmi_exit);