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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/miscdevice.h>
27#include <linux/module.h>
28#include <linux/platform_device.h>
29#include <linux/slab.h>
30#include <linux/sysfs.h>
31#include <linux/types.h>
32#include <linux/uaccess.h>
33#include <linux/uuid.h>
34#include <linux/wmi.h>
35#include <linux/fs.h>
36#include <uapi/linux/wmi.h>
37
38MODULE_AUTHOR("Carlos Corbacho");
39MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
40MODULE_LICENSE("GPL");
41
42static LIST_HEAD(wmi_block_list);
43
44struct guid_block {
45 guid_t guid;
46 union {
47 char object_id[2];
48 struct {
49 unsigned char notify_id;
50 unsigned char reserved;
51 };
52 };
53 u8 instance_count;
54 u8 flags;
55} __packed;
56static_assert(sizeof(typeof_member(struct guid_block, guid)) == 16);
57static_assert(sizeof(struct guid_block) == 20);
58static_assert(__alignof__(struct guid_block) == 1);
59
60enum { /* wmi_block flags */
61 WMI_READ_TAKES_NO_ARGS,
62 WMI_PROBED,
63};
64
65struct wmi_block {
66 struct wmi_device dev;
67 struct list_head list;
68 struct guid_block gblock;
69 struct miscdevice char_dev;
70 struct mutex char_mutex;
71 struct acpi_device *acpi_device;
72 wmi_notify_handler handler;
73 void *handler_data;
74 u64 req_buf_size;
75 unsigned long flags;
76};
77
78
79/*
80 * If the GUID data block is marked as expensive, we must enable and
81 * explicitily disable data collection.
82 */
83#define ACPI_WMI_EXPENSIVE BIT(0)
84#define ACPI_WMI_METHOD BIT(1) /* GUID is a method */
85#define ACPI_WMI_STRING BIT(2) /* GUID takes & returns a string */
86#define ACPI_WMI_EVENT BIT(3) /* GUID is an event */
87
88static bool debug_event;
89module_param(debug_event, bool, 0444);
90MODULE_PARM_DESC(debug_event,
91 "Log WMI Events [0/1]");
92
93static bool debug_dump_wdg;
94module_param(debug_dump_wdg, bool, 0444);
95MODULE_PARM_DESC(debug_dump_wdg,
96 "Dump available WMI interfaces [0/1]");
97
98static const struct acpi_device_id wmi_device_ids[] = {
99 {"PNP0C14", 0},
100 {"pnp0c14", 0},
101 { }
102};
103MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
104
105/* allow duplicate GUIDs as these device drivers use struct wmi_driver */
106static const char * const allow_duplicates[] = {
107 "05901221-D566-11D1-B2F0-00A0C9062910", /* wmi-bmof */
108 "8A42EA14-4F2A-FD45-6422-0087F7A7E608", /* dell-wmi-ddv */
109 NULL
110};
111
112/*
113 * GUID parsing functions
114 */
115
116static acpi_status find_guid(const char *guid_string, struct wmi_block **out)
117{
118 guid_t guid_input;
119 struct wmi_block *wblock;
120
121 if (!guid_string)
122 return AE_BAD_PARAMETER;
123
124 if (guid_parse(guid_string, &guid_input))
125 return AE_BAD_PARAMETER;
126
127 list_for_each_entry(wblock, &wmi_block_list, list) {
128 if (guid_equal(&wblock->gblock.guid, &guid_input)) {
129 if (out)
130 *out = wblock;
131
132 return AE_OK;
133 }
134 }
135
136 return AE_NOT_FOUND;
137}
138
139static const void *find_guid_context(struct wmi_block *wblock,
140 struct wmi_driver *wdriver)
141{
142 const struct wmi_device_id *id;
143
144 id = wdriver->id_table;
145 if (!id)
146 return NULL;
147
148 while (*id->guid_string) {
149 guid_t guid_input;
150
151 if (guid_parse(id->guid_string, &guid_input))
152 continue;
153 if (guid_equal(&wblock->gblock.guid, &guid_input))
154 return id->context;
155 id++;
156 }
157 return NULL;
158}
159
160static int get_subobj_info(acpi_handle handle, const char *pathname,
161 struct acpi_device_info **info)
162{
163 struct acpi_device_info *dummy_info, **info_ptr;
164 acpi_handle subobj_handle;
165 acpi_status status;
166
167 status = acpi_get_handle(handle, (char *)pathname, &subobj_handle);
168 if (status == AE_NOT_FOUND)
169 return -ENOENT;
170 else if (ACPI_FAILURE(status))
171 return -EIO;
172
173 info_ptr = info ? info : &dummy_info;
174 status = acpi_get_object_info(subobj_handle, info_ptr);
175 if (ACPI_FAILURE(status))
176 return -EIO;
177
178 if (!info)
179 kfree(dummy_info);
180
181 return 0;
182}
183
184static acpi_status wmi_method_enable(struct wmi_block *wblock, bool enable)
185{
186 struct guid_block *block;
187 char method[5];
188 acpi_status status;
189 acpi_handle handle;
190
191 block = &wblock->gblock;
192 handle = wblock->acpi_device->handle;
193
194 snprintf(method, 5, "WE%02X", block->notify_id);
195 status = acpi_execute_simple_method(handle, method, enable);
196 if (status == AE_NOT_FOUND)
197 return AE_OK;
198
199 return status;
200}
201
202#define WMI_ACPI_METHOD_NAME_SIZE 5
203
204static inline void get_acpi_method_name(const struct wmi_block *wblock,
205 const char method,
206 char buffer[static WMI_ACPI_METHOD_NAME_SIZE])
207{
208 static_assert(ARRAY_SIZE(wblock->gblock.object_id) == 2);
209 static_assert(WMI_ACPI_METHOD_NAME_SIZE >= 5);
210
211 buffer[0] = 'W';
212 buffer[1] = method;
213 buffer[2] = wblock->gblock.object_id[0];
214 buffer[3] = wblock->gblock.object_id[1];
215 buffer[4] = '\0';
216}
217
218static inline acpi_object_type get_param_acpi_type(const struct wmi_block *wblock)
219{
220 if (wblock->gblock.flags & ACPI_WMI_STRING)
221 return ACPI_TYPE_STRING;
222 else
223 return ACPI_TYPE_BUFFER;
224}
225
226static acpi_status get_event_data(const struct wmi_block *wblock, struct acpi_buffer *out)
227{
228 union acpi_object param = {
229 .integer = {
230 .type = ACPI_TYPE_INTEGER,
231 .value = wblock->gblock.notify_id,
232 }
233 };
234 struct acpi_object_list input = {
235 .count = 1,
236 .pointer = ¶m,
237 };
238
239 return acpi_evaluate_object(wblock->acpi_device->handle, "_WED", &input, out);
240}
241
242/*
243 * Exported WMI functions
244 */
245
246/**
247 * set_required_buffer_size - Sets the buffer size needed for performing IOCTL
248 * @wdev: A wmi bus device from a driver
249 * @length: Required buffer size
250 *
251 * Allocates memory needed for buffer, stores the buffer size in that memory
252 */
253int set_required_buffer_size(struct wmi_device *wdev, u64 length)
254{
255 struct wmi_block *wblock;
256
257 wblock = container_of(wdev, struct wmi_block, dev);
258 wblock->req_buf_size = length;
259
260 return 0;
261}
262EXPORT_SYMBOL_GPL(set_required_buffer_size);
263
264/**
265 * wmi_evaluate_method - Evaluate a WMI method
266 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
267 * @instance: Instance index
268 * @method_id: Method ID to call
269 * @in: Buffer containing input for the method call
270 * @out: Empty buffer to return the method results
271 *
272 * Call an ACPI-WMI method
273 */
274acpi_status wmi_evaluate_method(const char *guid_string, u8 instance, u32 method_id,
275 const struct acpi_buffer *in, struct acpi_buffer *out)
276{
277 struct wmi_block *wblock = NULL;
278 acpi_status status;
279
280 status = find_guid(guid_string, &wblock);
281 if (ACPI_FAILURE(status))
282 return status;
283
284 return wmidev_evaluate_method(&wblock->dev, instance, method_id,
285 in, out);
286}
287EXPORT_SYMBOL_GPL(wmi_evaluate_method);
288
289/**
290 * wmidev_evaluate_method - Evaluate a WMI method
291 * @wdev: A wmi bus device from a driver
292 * @instance: Instance index
293 * @method_id: Method ID to call
294 * @in: Buffer containing input for the method call
295 * @out: Empty buffer to return the method results
296 *
297 * Call an ACPI-WMI method
298 */
299acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance, u32 method_id,
300 const struct acpi_buffer *in, struct acpi_buffer *out)
301{
302 struct guid_block *block;
303 struct wmi_block *wblock;
304 acpi_handle handle;
305 struct acpi_object_list input;
306 union acpi_object params[3];
307 char method[WMI_ACPI_METHOD_NAME_SIZE];
308
309 wblock = container_of(wdev, struct wmi_block, dev);
310 block = &wblock->gblock;
311 handle = wblock->acpi_device->handle;
312
313 if (!(block->flags & ACPI_WMI_METHOD))
314 return AE_BAD_DATA;
315
316 if (block->instance_count <= instance)
317 return AE_BAD_PARAMETER;
318
319 input.count = 2;
320 input.pointer = params;
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
326 if (in) {
327 input.count = 3;
328
329 params[2].type = get_param_acpi_type(wblock);
330 params[2].buffer.length = in->length;
331 params[2].buffer.pointer = in->pointer;
332 }
333
334 get_acpi_method_name(wblock, 'M', method);
335
336 return acpi_evaluate_object(handle, method, &input, out);
337}
338EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
339
340static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
341 struct acpi_buffer *out)
342{
343 struct guid_block *block;
344 acpi_handle handle;
345 acpi_status status, wc_status = AE_ERROR;
346 struct acpi_object_list input;
347 union acpi_object wq_params[1];
348 char wc_method[WMI_ACPI_METHOD_NAME_SIZE];
349 char method[WMI_ACPI_METHOD_NAME_SIZE];
350
351 if (!out)
352 return AE_BAD_PARAMETER;
353
354 block = &wblock->gblock;
355 handle = wblock->acpi_device->handle;
356
357 if (block->instance_count <= instance)
358 return AE_BAD_PARAMETER;
359
360 /* Check GUID is a data block */
361 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
362 return AE_ERROR;
363
364 input.count = 1;
365 input.pointer = wq_params;
366 wq_params[0].type = ACPI_TYPE_INTEGER;
367 wq_params[0].integer.value = instance;
368
369 if (instance == 0 && test_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags))
370 input.count = 0;
371
372 /*
373 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
374 * enable collection.
375 */
376 if (block->flags & ACPI_WMI_EXPENSIVE) {
377 get_acpi_method_name(wblock, 'C', wc_method);
378
379 /*
380 * Some GUIDs break the specification by declaring themselves
381 * expensive, but have no corresponding WCxx method. So we
382 * should not fail if this happens.
383 */
384 wc_status = acpi_execute_simple_method(handle, wc_method, 1);
385 }
386
387 get_acpi_method_name(wblock, 'Q', method);
388 status = acpi_evaluate_object(handle, method, &input, out);
389
390 /*
391 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
392 * the WQxx method failed - we should disable collection anyway.
393 */
394 if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
395 /*
396 * Ignore whether this WCxx call succeeds or not since
397 * the previously executed WQxx method call might have
398 * succeeded, and returning the failing status code
399 * of this call would throw away the result of the WQxx
400 * call, potentially leaking memory.
401 */
402 acpi_execute_simple_method(handle, wc_method, 0);
403 }
404
405 return status;
406}
407
408/**
409 * wmi_query_block - Return contents of a WMI block (deprecated)
410 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
411 * @instance: Instance index
412 * @out: Empty buffer to return the contents of the data block to
413 *
414 * Return the contents of an ACPI-WMI data block to a buffer
415 */
416acpi_status wmi_query_block(const char *guid_string, u8 instance,
417 struct acpi_buffer *out)
418{
419 struct wmi_block *wblock;
420 acpi_status status;
421
422 status = find_guid(guid_string, &wblock);
423 if (ACPI_FAILURE(status))
424 return status;
425
426 return __query_block(wblock, instance, out);
427}
428EXPORT_SYMBOL_GPL(wmi_query_block);
429
430union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
431{
432 struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
433 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
434
435 if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
436 return NULL;
437
438 return out.pointer;
439}
440EXPORT_SYMBOL_GPL(wmidev_block_query);
441
442/**
443 * wmi_set_block - Write to a WMI block
444 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
445 * @instance: Instance index
446 * @in: Buffer containing new values for the data block
447 *
448 * Write the contents of the input buffer to an ACPI-WMI data block
449 */
450acpi_status wmi_set_block(const char *guid_string, u8 instance,
451 const struct acpi_buffer *in)
452{
453 struct wmi_block *wblock = NULL;
454 struct guid_block *block;
455 acpi_handle handle;
456 struct acpi_object_list input;
457 union acpi_object params[2];
458 char method[WMI_ACPI_METHOD_NAME_SIZE];
459 acpi_status status;
460
461 if (!in)
462 return AE_BAD_DATA;
463
464 status = find_guid(guid_string, &wblock);
465 if (ACPI_FAILURE(status))
466 return status;
467
468 block = &wblock->gblock;
469 handle = wblock->acpi_device->handle;
470
471 if (block->instance_count <= instance)
472 return AE_BAD_PARAMETER;
473
474 /* Check GUID is a data block */
475 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
476 return AE_ERROR;
477
478 input.count = 2;
479 input.pointer = params;
480 params[0].type = ACPI_TYPE_INTEGER;
481 params[0].integer.value = instance;
482 params[1].type = get_param_acpi_type(wblock);
483 params[1].buffer.length = in->length;
484 params[1].buffer.pointer = in->pointer;
485
486 get_acpi_method_name(wblock, 'S', method);
487
488 return acpi_evaluate_object(handle, method, &input, NULL);
489}
490EXPORT_SYMBOL_GPL(wmi_set_block);
491
492static void wmi_dump_wdg(const struct guid_block *g)
493{
494 pr_info("%pUL:\n", &g->guid);
495 if (g->flags & ACPI_WMI_EVENT)
496 pr_info("\tnotify_id: 0x%02X\n", g->notify_id);
497 else
498 pr_info("\tobject_id: %2pE\n", g->object_id);
499 pr_info("\tinstance_count: %d\n", g->instance_count);
500 pr_info("\tflags: %#x", g->flags);
501 if (g->flags) {
502 if (g->flags & ACPI_WMI_EXPENSIVE)
503 pr_cont(" ACPI_WMI_EXPENSIVE");
504 if (g->flags & ACPI_WMI_METHOD)
505 pr_cont(" ACPI_WMI_METHOD");
506 if (g->flags & ACPI_WMI_STRING)
507 pr_cont(" ACPI_WMI_STRING");
508 if (g->flags & ACPI_WMI_EVENT)
509 pr_cont(" ACPI_WMI_EVENT");
510 }
511 pr_cont("\n");
512
513}
514
515static void wmi_notify_debug(u32 value, void *context)
516{
517 struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
518 union acpi_object *obj;
519 acpi_status status;
520
521 status = wmi_get_event_data(value, &response);
522 if (status != AE_OK) {
523 pr_info("bad event status 0x%x\n", status);
524 return;
525 }
526
527 obj = response.pointer;
528 if (!obj)
529 return;
530
531 pr_info("DEBUG: event 0x%02X ", value);
532 switch (obj->type) {
533 case ACPI_TYPE_BUFFER:
534 pr_cont("BUFFER_TYPE - length %u\n", obj->buffer.length);
535 break;
536 case ACPI_TYPE_STRING:
537 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
538 break;
539 case ACPI_TYPE_INTEGER:
540 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
541 break;
542 case ACPI_TYPE_PACKAGE:
543 pr_cont("PACKAGE_TYPE - %u elements\n", obj->package.count);
544 break;
545 default:
546 pr_cont("object type 0x%X\n", obj->type);
547 }
548 kfree(obj);
549}
550
551/**
552 * wmi_install_notify_handler - Register handler for WMI events
553 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
554 * @handler: Function to handle notifications
555 * @data: Data to be returned to handler when event is fired
556 *
557 * Register a handler for events sent to the ACPI-WMI mapper device.
558 */
559acpi_status wmi_install_notify_handler(const char *guid,
560 wmi_notify_handler handler,
561 void *data)
562{
563 struct wmi_block *block;
564 acpi_status status = AE_NOT_EXIST;
565 guid_t guid_input;
566
567 if (!guid || !handler)
568 return AE_BAD_PARAMETER;
569
570 if (guid_parse(guid, &guid_input))
571 return AE_BAD_PARAMETER;
572
573 list_for_each_entry(block, &wmi_block_list, list) {
574 acpi_status wmi_status;
575
576 if (guid_equal(&block->gblock.guid, &guid_input)) {
577 if (block->handler &&
578 block->handler != wmi_notify_debug)
579 return AE_ALREADY_ACQUIRED;
580
581 block->handler = handler;
582 block->handler_data = data;
583
584 wmi_status = wmi_method_enable(block, true);
585 if ((wmi_status != AE_OK) ||
586 ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
587 status = wmi_status;
588 }
589 }
590
591 return status;
592}
593EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
594
595/**
596 * wmi_remove_notify_handler - Unregister handler for WMI events
597 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
598 *
599 * Unregister handler for events sent to the ACPI-WMI mapper device.
600 */
601acpi_status wmi_remove_notify_handler(const char *guid)
602{
603 struct wmi_block *block;
604 acpi_status status = AE_NOT_EXIST;
605 guid_t guid_input;
606
607 if (!guid)
608 return AE_BAD_PARAMETER;
609
610 if (guid_parse(guid, &guid_input))
611 return AE_BAD_PARAMETER;
612
613 list_for_each_entry(block, &wmi_block_list, list) {
614 acpi_status wmi_status;
615
616 if (guid_equal(&block->gblock.guid, &guid_input)) {
617 if (!block->handler ||
618 block->handler == wmi_notify_debug)
619 return AE_NULL_ENTRY;
620
621 if (debug_event) {
622 block->handler = wmi_notify_debug;
623 status = AE_OK;
624 } else {
625 wmi_status = wmi_method_enable(block, false);
626 block->handler = NULL;
627 block->handler_data = NULL;
628 if ((wmi_status != AE_OK) ||
629 ((wmi_status == AE_OK) &&
630 (status == AE_NOT_EXIST)))
631 status = wmi_status;
632 }
633 }
634 }
635
636 return status;
637}
638EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
639
640/**
641 * wmi_get_event_data - Get WMI data associated with an event
642 *
643 * @event: Event to find
644 * @out: Buffer to hold event data. out->pointer should be freed with kfree()
645 *
646 * Returns extra data associated with an event in WMI.
647 */
648acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
649{
650 struct wmi_block *wblock;
651
652 list_for_each_entry(wblock, &wmi_block_list, list) {
653 struct guid_block *gblock = &wblock->gblock;
654
655 if ((gblock->flags & ACPI_WMI_EVENT) && gblock->notify_id == event)
656 return get_event_data(wblock, out);
657 }
658
659 return AE_NOT_FOUND;
660}
661EXPORT_SYMBOL_GPL(wmi_get_event_data);
662
663/**
664 * wmi_has_guid - Check if a GUID is available
665 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
666 *
667 * Check if a given GUID is defined by _WDG
668 */
669bool wmi_has_guid(const char *guid_string)
670{
671 return ACPI_SUCCESS(find_guid(guid_string, NULL));
672}
673EXPORT_SYMBOL_GPL(wmi_has_guid);
674
675/**
676 * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID
677 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
678 *
679 * Find the _UID of ACPI device associated with this WMI GUID.
680 *
681 * Return: The ACPI _UID field value or NULL if the WMI GUID was not found
682 */
683char *wmi_get_acpi_device_uid(const char *guid_string)
684{
685 struct wmi_block *wblock = NULL;
686 acpi_status status;
687
688 status = find_guid(guid_string, &wblock);
689 if (ACPI_FAILURE(status))
690 return NULL;
691
692 return acpi_device_uid(wblock->acpi_device);
693}
694EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
695
696static struct wmi_block *dev_to_wblock(struct device *dev)
697{
698 return container_of(dev, struct wmi_block, dev.dev);
699}
700
701static struct wmi_device *dev_to_wdev(struct device *dev)
702{
703 return container_of(dev, struct wmi_device, dev);
704}
705
706static inline struct wmi_driver *drv_to_wdrv(struct device_driver *drv)
707{
708 return container_of(drv, struct wmi_driver, driver);
709}
710
711/*
712 * sysfs interface
713 */
714static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
715 char *buf)
716{
717 struct wmi_block *wblock = dev_to_wblock(dev);
718
719 return sysfs_emit(buf, "wmi:%pUL\n", &wblock->gblock.guid);
720}
721static DEVICE_ATTR_RO(modalias);
722
723static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
724 char *buf)
725{
726 struct wmi_block *wblock = dev_to_wblock(dev);
727
728 return sysfs_emit(buf, "%pUL\n", &wblock->gblock.guid);
729}
730static DEVICE_ATTR_RO(guid);
731
732static ssize_t instance_count_show(struct device *dev,
733 struct device_attribute *attr, char *buf)
734{
735 struct wmi_block *wblock = dev_to_wblock(dev);
736
737 return sysfs_emit(buf, "%d\n", (int)wblock->gblock.instance_count);
738}
739static DEVICE_ATTR_RO(instance_count);
740
741static ssize_t expensive_show(struct device *dev,
742 struct device_attribute *attr, char *buf)
743{
744 struct wmi_block *wblock = dev_to_wblock(dev);
745
746 return sysfs_emit(buf, "%d\n",
747 (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
748}
749static DEVICE_ATTR_RO(expensive);
750
751static struct attribute *wmi_attrs[] = {
752 &dev_attr_modalias.attr,
753 &dev_attr_guid.attr,
754 &dev_attr_instance_count.attr,
755 &dev_attr_expensive.attr,
756 NULL
757};
758ATTRIBUTE_GROUPS(wmi);
759
760static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
761 char *buf)
762{
763 struct wmi_block *wblock = dev_to_wblock(dev);
764
765 return sysfs_emit(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
766}
767static DEVICE_ATTR_RO(notify_id);
768
769static struct attribute *wmi_event_attrs[] = {
770 &dev_attr_notify_id.attr,
771 NULL
772};
773ATTRIBUTE_GROUPS(wmi_event);
774
775static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
776 char *buf)
777{
778 struct wmi_block *wblock = dev_to_wblock(dev);
779
780 return sysfs_emit(buf, "%c%c\n", wblock->gblock.object_id[0],
781 wblock->gblock.object_id[1]);
782}
783static DEVICE_ATTR_RO(object_id);
784
785static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
786 char *buf)
787{
788 struct wmi_device *wdev = dev_to_wdev(dev);
789
790 return sysfs_emit(buf, "%d\n", (int)wdev->setable);
791}
792static DEVICE_ATTR_RO(setable);
793
794static struct attribute *wmi_data_attrs[] = {
795 &dev_attr_object_id.attr,
796 &dev_attr_setable.attr,
797 NULL
798};
799ATTRIBUTE_GROUPS(wmi_data);
800
801static struct attribute *wmi_method_attrs[] = {
802 &dev_attr_object_id.attr,
803 NULL
804};
805ATTRIBUTE_GROUPS(wmi_method);
806
807static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
808{
809 struct wmi_block *wblock = dev_to_wblock(dev);
810
811 if (add_uevent_var(env, "MODALIAS=wmi:%pUL", &wblock->gblock.guid))
812 return -ENOMEM;
813
814 if (add_uevent_var(env, "WMI_GUID=%pUL", &wblock->gblock.guid))
815 return -ENOMEM;
816
817 return 0;
818}
819
820static void wmi_dev_release(struct device *dev)
821{
822 struct wmi_block *wblock = dev_to_wblock(dev);
823
824 kfree(wblock);
825}
826
827static int wmi_dev_match(struct device *dev, struct device_driver *driver)
828{
829 struct wmi_driver *wmi_driver = drv_to_wdrv(driver);
830 struct wmi_block *wblock = dev_to_wblock(dev);
831 const struct wmi_device_id *id = wmi_driver->id_table;
832
833 if (id == NULL)
834 return 0;
835
836 while (*id->guid_string) {
837 guid_t driver_guid;
838
839 if (WARN_ON(guid_parse(id->guid_string, &driver_guid)))
840 continue;
841 if (guid_equal(&driver_guid, &wblock->gblock.guid))
842 return 1;
843
844 id++;
845 }
846
847 return 0;
848}
849static int wmi_char_open(struct inode *inode, struct file *filp)
850{
851 const char *driver_name = filp->f_path.dentry->d_iname;
852 struct wmi_block *wblock;
853 struct wmi_block *next;
854
855 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
856 if (!wblock->dev.dev.driver)
857 continue;
858 if (strcmp(driver_name, wblock->dev.dev.driver->name) == 0) {
859 filp->private_data = wblock;
860 break;
861 }
862 }
863
864 if (!filp->private_data)
865 return -ENODEV;
866
867 return nonseekable_open(inode, filp);
868}
869
870static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
871 size_t length, loff_t *offset)
872{
873 struct wmi_block *wblock = filp->private_data;
874
875 return simple_read_from_buffer(buffer, length, offset,
876 &wblock->req_buf_size,
877 sizeof(wblock->req_buf_size));
878}
879
880static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
881{
882 struct wmi_ioctl_buffer __user *input =
883 (struct wmi_ioctl_buffer __user *) arg;
884 struct wmi_block *wblock = filp->private_data;
885 struct wmi_ioctl_buffer *buf;
886 struct wmi_driver *wdriver;
887 int ret;
888
889 if (_IOC_TYPE(cmd) != WMI_IOC)
890 return -ENOTTY;
891
892 /* make sure we're not calling a higher instance than exists*/
893 if (_IOC_NR(cmd) >= wblock->gblock.instance_count)
894 return -EINVAL;
895
896 mutex_lock(&wblock->char_mutex);
897 buf = wblock->handler_data;
898 if (get_user(buf->length, &input->length)) {
899 dev_dbg(&wblock->dev.dev, "Read length from user failed\n");
900 ret = -EFAULT;
901 goto out_ioctl;
902 }
903 /* if it's too small, abort */
904 if (buf->length < wblock->req_buf_size) {
905 dev_err(&wblock->dev.dev,
906 "Buffer %lld too small, need at least %lld\n",
907 buf->length, wblock->req_buf_size);
908 ret = -EINVAL;
909 goto out_ioctl;
910 }
911 /* if it's too big, warn, driver will only use what is needed */
912 if (buf->length > wblock->req_buf_size)
913 dev_warn(&wblock->dev.dev,
914 "Buffer %lld is bigger than required %lld\n",
915 buf->length, wblock->req_buf_size);
916
917 /* copy the structure from userspace */
918 if (copy_from_user(buf, input, wblock->req_buf_size)) {
919 dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n",
920 wblock->req_buf_size);
921 ret = -EFAULT;
922 goto out_ioctl;
923 }
924
925 /* let the driver do any filtering and do the call */
926 wdriver = drv_to_wdrv(wblock->dev.dev.driver);
927 if (!try_module_get(wdriver->driver.owner)) {
928 ret = -EBUSY;
929 goto out_ioctl;
930 }
931 ret = wdriver->filter_callback(&wblock->dev, cmd, buf);
932 module_put(wdriver->driver.owner);
933 if (ret)
934 goto out_ioctl;
935
936 /* return the result (only up to our internal buffer size) */
937 if (copy_to_user(input, buf, wblock->req_buf_size)) {
938 dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n",
939 wblock->req_buf_size);
940 ret = -EFAULT;
941 }
942
943out_ioctl:
944 mutex_unlock(&wblock->char_mutex);
945 return ret;
946}
947
948static const struct file_operations wmi_fops = {
949 .owner = THIS_MODULE,
950 .read = wmi_char_read,
951 .open = wmi_char_open,
952 .unlocked_ioctl = wmi_ioctl,
953 .compat_ioctl = compat_ptr_ioctl,
954};
955
956static int wmi_dev_probe(struct device *dev)
957{
958 struct wmi_block *wblock = dev_to_wblock(dev);
959 struct wmi_driver *wdriver = drv_to_wdrv(dev->driver);
960 int ret = 0;
961 char *buf;
962
963 if (ACPI_FAILURE(wmi_method_enable(wblock, true)))
964 dev_warn(dev, "failed to enable device -- probing anyway\n");
965
966 if (wdriver->probe) {
967 ret = wdriver->probe(dev_to_wdev(dev),
968 find_guid_context(wblock, wdriver));
969 if (ret != 0)
970 goto probe_failure;
971 }
972
973 /* driver wants a character device made */
974 if (wdriver->filter_callback) {
975 /* check that required buffer size declared by driver or MOF */
976 if (!wblock->req_buf_size) {
977 dev_err(&wblock->dev.dev,
978 "Required buffer size not set\n");
979 ret = -EINVAL;
980 goto probe_failure;
981 }
982
983 wblock->handler_data = kmalloc(wblock->req_buf_size,
984 GFP_KERNEL);
985 if (!wblock->handler_data) {
986 ret = -ENOMEM;
987 goto probe_failure;
988 }
989
990 buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name);
991 if (!buf) {
992 ret = -ENOMEM;
993 goto probe_string_failure;
994 }
995 wblock->char_dev.minor = MISC_DYNAMIC_MINOR;
996 wblock->char_dev.name = buf;
997 wblock->char_dev.fops = &wmi_fops;
998 wblock->char_dev.mode = 0444;
999 ret = misc_register(&wblock->char_dev);
1000 if (ret) {
1001 dev_warn(dev, "failed to register char dev: %d\n", ret);
1002 ret = -ENOMEM;
1003 goto probe_misc_failure;
1004 }
1005 }
1006
1007 set_bit(WMI_PROBED, &wblock->flags);
1008 return 0;
1009
1010probe_misc_failure:
1011 kfree(buf);
1012probe_string_failure:
1013 kfree(wblock->handler_data);
1014probe_failure:
1015 if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
1016 dev_warn(dev, "failed to disable device\n");
1017 return ret;
1018}
1019
1020static void wmi_dev_remove(struct device *dev)
1021{
1022 struct wmi_block *wblock = dev_to_wblock(dev);
1023 struct wmi_driver *wdriver = drv_to_wdrv(dev->driver);
1024
1025 clear_bit(WMI_PROBED, &wblock->flags);
1026
1027 if (wdriver->filter_callback) {
1028 misc_deregister(&wblock->char_dev);
1029 kfree(wblock->char_dev.name);
1030 kfree(wblock->handler_data);
1031 }
1032
1033 if (wdriver->remove)
1034 wdriver->remove(dev_to_wdev(dev));
1035
1036 if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
1037 dev_warn(dev, "failed to disable device\n");
1038}
1039
1040static struct class wmi_bus_class = {
1041 .name = "wmi_bus",
1042};
1043
1044static struct bus_type wmi_bus_type = {
1045 .name = "wmi",
1046 .dev_groups = wmi_groups,
1047 .match = wmi_dev_match,
1048 .uevent = wmi_dev_uevent,
1049 .probe = wmi_dev_probe,
1050 .remove = wmi_dev_remove,
1051};
1052
1053static const struct device_type wmi_type_event = {
1054 .name = "event",
1055 .groups = wmi_event_groups,
1056 .release = wmi_dev_release,
1057};
1058
1059static const struct device_type wmi_type_method = {
1060 .name = "method",
1061 .groups = wmi_method_groups,
1062 .release = wmi_dev_release,
1063};
1064
1065static const struct device_type wmi_type_data = {
1066 .name = "data",
1067 .groups = wmi_data_groups,
1068 .release = wmi_dev_release,
1069};
1070
1071/*
1072 * _WDG is a static list that is only parsed at startup,
1073 * so it's safe to count entries without extra protection.
1074 */
1075static int guid_count(const guid_t *guid)
1076{
1077 struct wmi_block *wblock;
1078 int count = 0;
1079
1080 list_for_each_entry(wblock, &wmi_block_list, list) {
1081 if (guid_equal(&wblock->gblock.guid, guid))
1082 count++;
1083 }
1084
1085 return count;
1086}
1087
1088static int wmi_create_device(struct device *wmi_bus_dev,
1089 struct wmi_block *wblock,
1090 struct acpi_device *device)
1091{
1092 struct acpi_device_info *info;
1093 char method[WMI_ACPI_METHOD_NAME_SIZE];
1094 int result;
1095 uint count;
1096
1097 if (wblock->gblock.flags & ACPI_WMI_EVENT) {
1098 wblock->dev.dev.type = &wmi_type_event;
1099 goto out_init;
1100 }
1101
1102 if (wblock->gblock.flags & ACPI_WMI_METHOD) {
1103 wblock->dev.dev.type = &wmi_type_method;
1104 mutex_init(&wblock->char_mutex);
1105 goto out_init;
1106 }
1107
1108 /*
1109 * Data Block Query Control Method (WQxx by convention) is
1110 * required per the WMI documentation. If it is not present,
1111 * we ignore this data block.
1112 */
1113 get_acpi_method_name(wblock, 'Q', method);
1114 result = get_subobj_info(device->handle, method, &info);
1115
1116 if (result) {
1117 dev_warn(wmi_bus_dev,
1118 "%s data block query control method not found\n",
1119 method);
1120 return result;
1121 }
1122
1123 wblock->dev.dev.type = &wmi_type_data;
1124
1125 /*
1126 * The Microsoft documentation specifically states:
1127 *
1128 * Data blocks registered with only a single instance
1129 * can ignore the parameter.
1130 *
1131 * ACPICA will get mad at us if we call the method with the wrong number
1132 * of arguments, so check what our method expects. (On some Dell
1133 * laptops, WQxx may not be a method at all.)
1134 */
1135 if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1136 set_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags);
1137
1138 kfree(info);
1139
1140 get_acpi_method_name(wblock, 'S', method);
1141 result = get_subobj_info(device->handle, method, NULL);
1142
1143 if (result == 0)
1144 wblock->dev.setable = true;
1145
1146 out_init:
1147 wblock->dev.dev.bus = &wmi_bus_type;
1148 wblock->dev.dev.parent = wmi_bus_dev;
1149
1150 count = guid_count(&wblock->gblock.guid);
1151 if (count)
1152 dev_set_name(&wblock->dev.dev, "%pUL-%d", &wblock->gblock.guid, count);
1153 else
1154 dev_set_name(&wblock->dev.dev, "%pUL", &wblock->gblock.guid);
1155
1156 device_initialize(&wblock->dev.dev);
1157
1158 return 0;
1159}
1160
1161static void wmi_free_devices(struct acpi_device *device)
1162{
1163 struct wmi_block *wblock, *next;
1164
1165 /* Delete devices for all the GUIDs */
1166 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1167 if (wblock->acpi_device == device) {
1168 list_del(&wblock->list);
1169 device_unregister(&wblock->dev.dev);
1170 }
1171 }
1172}
1173
1174static bool guid_already_parsed_for_legacy(struct acpi_device *device, const guid_t *guid)
1175{
1176 struct wmi_block *wblock;
1177
1178 list_for_each_entry(wblock, &wmi_block_list, list) {
1179 /* skip warning and register if we know the driver will use struct wmi_driver */
1180 for (int i = 0; allow_duplicates[i] != NULL; i++) {
1181 guid_t tmp;
1182
1183 if (guid_parse(allow_duplicates[i], &tmp))
1184 continue;
1185 if (guid_equal(&tmp, guid))
1186 return false;
1187 }
1188 if (guid_equal(&wblock->gblock.guid, guid)) {
1189 /*
1190 * Because we historically didn't track the relationship
1191 * between GUIDs and ACPI nodes, we don't know whether
1192 * we need to suppress GUIDs that are unique on a
1193 * given node but duplicated across nodes.
1194 */
1195 dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
1196 guid, dev_name(&wblock->acpi_device->dev));
1197 return true;
1198 }
1199 }
1200
1201 return false;
1202}
1203
1204/*
1205 * Parse the _WDG method for the GUID data blocks
1206 */
1207static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
1208{
1209 struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1210 const struct guid_block *gblock;
1211 struct wmi_block *wblock, *next;
1212 union acpi_object *obj;
1213 acpi_status status;
1214 int retval = 0;
1215 u32 i, total;
1216
1217 status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1218 if (ACPI_FAILURE(status))
1219 return -ENXIO;
1220
1221 obj = out.pointer;
1222 if (!obj)
1223 return -ENXIO;
1224
1225 if (obj->type != ACPI_TYPE_BUFFER) {
1226 retval = -ENXIO;
1227 goto out_free_pointer;
1228 }
1229
1230 gblock = (const struct guid_block *)obj->buffer.pointer;
1231 total = obj->buffer.length / sizeof(struct guid_block);
1232
1233 for (i = 0; i < total; i++) {
1234 if (debug_dump_wdg)
1235 wmi_dump_wdg(&gblock[i]);
1236
1237 if (guid_already_parsed_for_legacy(device, &gblock[i].guid))
1238 continue;
1239
1240 wblock = kzalloc(sizeof(*wblock), GFP_KERNEL);
1241 if (!wblock) {
1242 retval = -ENOMEM;
1243 break;
1244 }
1245
1246 wblock->acpi_device = device;
1247 wblock->gblock = gblock[i];
1248
1249 retval = wmi_create_device(wmi_bus_dev, wblock, device);
1250 if (retval) {
1251 kfree(wblock);
1252 continue;
1253 }
1254
1255 list_add_tail(&wblock->list, &wmi_block_list);
1256
1257 if (debug_event) {
1258 wblock->handler = wmi_notify_debug;
1259 wmi_method_enable(wblock, true);
1260 }
1261 }
1262
1263 /*
1264 * Now that all of the devices are created, add them to the
1265 * device tree and probe subdrivers.
1266 */
1267 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1268 if (wblock->acpi_device != device)
1269 continue;
1270
1271 retval = device_add(&wblock->dev.dev);
1272 if (retval) {
1273 dev_err(wmi_bus_dev, "failed to register %pUL\n",
1274 &wblock->gblock.guid);
1275 if (debug_event)
1276 wmi_method_enable(wblock, false);
1277 list_del(&wblock->list);
1278 put_device(&wblock->dev.dev);
1279 }
1280 }
1281
1282out_free_pointer:
1283 kfree(out.pointer);
1284 return retval;
1285}
1286
1287/*
1288 * WMI can have EmbeddedControl access regions. In which case, we just want to
1289 * hand these off to the EC driver.
1290 */
1291static acpi_status
1292acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1293 u32 bits, u64 *value,
1294 void *handler_context, void *region_context)
1295{
1296 int result = 0, i = 0;
1297 u8 temp = 0;
1298
1299 if ((address > 0xFF) || !value)
1300 return AE_BAD_PARAMETER;
1301
1302 if (function != ACPI_READ && function != ACPI_WRITE)
1303 return AE_BAD_PARAMETER;
1304
1305 if (bits != 8)
1306 return AE_BAD_PARAMETER;
1307
1308 if (function == ACPI_READ) {
1309 result = ec_read(address, &temp);
1310 (*value) |= ((u64)temp) << i;
1311 } else {
1312 temp = 0xff & ((*value) >> i);
1313 result = ec_write(address, temp);
1314 }
1315
1316 switch (result) {
1317 case -EINVAL:
1318 return AE_BAD_PARAMETER;
1319 case -ENODEV:
1320 return AE_NOT_FOUND;
1321 case -ETIME:
1322 return AE_TIME;
1323 default:
1324 return AE_OK;
1325 }
1326}
1327
1328static void acpi_wmi_notify_handler(acpi_handle handle, u32 event,
1329 void *context)
1330{
1331 struct wmi_block *wblock = NULL, *iter;
1332
1333 list_for_each_entry(iter, &wmi_block_list, list) {
1334 struct guid_block *block = &iter->gblock;
1335
1336 if (iter->acpi_device->handle == handle &&
1337 (block->flags & ACPI_WMI_EVENT) &&
1338 (block->notify_id == event)) {
1339 wblock = iter;
1340 break;
1341 }
1342 }
1343
1344 if (!wblock)
1345 return;
1346
1347 /* If a driver is bound, then notify the driver. */
1348 if (test_bit(WMI_PROBED, &wblock->flags) && wblock->dev.dev.driver) {
1349 struct wmi_driver *driver = drv_to_wdrv(wblock->dev.dev.driver);
1350 struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL };
1351 acpi_status status;
1352
1353 if (!driver->no_notify_data) {
1354 status = get_event_data(wblock, &evdata);
1355 if (ACPI_FAILURE(status)) {
1356 dev_warn(&wblock->dev.dev, "failed to get event data\n");
1357 return;
1358 }
1359 }
1360
1361 if (driver->notify)
1362 driver->notify(&wblock->dev, evdata.pointer);
1363
1364 kfree(evdata.pointer);
1365 } else if (wblock->handler) {
1366 /* Legacy handler */
1367 wblock->handler(event, wblock->handler_data);
1368 }
1369
1370 if (debug_event)
1371 pr_info("DEBUG: GUID %pUL event 0x%02X\n", &wblock->gblock.guid, event);
1372
1373 acpi_bus_generate_netlink_event(
1374 wblock->acpi_device->pnp.device_class,
1375 dev_name(&wblock->dev.dev),
1376 event, 0);
1377}
1378
1379static int acpi_wmi_remove(struct platform_device *device)
1380{
1381 struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev);
1382
1383 acpi_remove_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY,
1384 acpi_wmi_notify_handler);
1385 acpi_remove_address_space_handler(acpi_device->handle,
1386 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
1387 wmi_free_devices(acpi_device);
1388 device_unregister(dev_get_drvdata(&device->dev));
1389
1390 return 0;
1391}
1392
1393static int acpi_wmi_probe(struct platform_device *device)
1394{
1395 struct acpi_device *acpi_device;
1396 struct device *wmi_bus_dev;
1397 acpi_status status;
1398 int error;
1399
1400 acpi_device = ACPI_COMPANION(&device->dev);
1401 if (!acpi_device) {
1402 dev_err(&device->dev, "ACPI companion is missing\n");
1403 return -ENODEV;
1404 }
1405
1406 status = acpi_install_address_space_handler(acpi_device->handle,
1407 ACPI_ADR_SPACE_EC,
1408 &acpi_wmi_ec_space_handler,
1409 NULL, NULL);
1410 if (ACPI_FAILURE(status)) {
1411 dev_err(&device->dev, "Error installing EC region handler\n");
1412 return -ENODEV;
1413 }
1414
1415 status = acpi_install_notify_handler(acpi_device->handle,
1416 ACPI_ALL_NOTIFY,
1417 acpi_wmi_notify_handler,
1418 NULL);
1419 if (ACPI_FAILURE(status)) {
1420 dev_err(&device->dev, "Error installing notify handler\n");
1421 error = -ENODEV;
1422 goto err_remove_ec_handler;
1423 }
1424
1425 wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0),
1426 NULL, "wmi_bus-%s", dev_name(&device->dev));
1427 if (IS_ERR(wmi_bus_dev)) {
1428 error = PTR_ERR(wmi_bus_dev);
1429 goto err_remove_notify_handler;
1430 }
1431 dev_set_drvdata(&device->dev, wmi_bus_dev);
1432
1433 error = parse_wdg(wmi_bus_dev, acpi_device);
1434 if (error) {
1435 pr_err("Failed to parse WDG method\n");
1436 goto err_remove_busdev;
1437 }
1438
1439 return 0;
1440
1441err_remove_busdev:
1442 device_unregister(wmi_bus_dev);
1443
1444err_remove_notify_handler:
1445 acpi_remove_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY,
1446 acpi_wmi_notify_handler);
1447
1448err_remove_ec_handler:
1449 acpi_remove_address_space_handler(acpi_device->handle,
1450 ACPI_ADR_SPACE_EC,
1451 &acpi_wmi_ec_space_handler);
1452
1453 return error;
1454}
1455
1456int __must_check __wmi_driver_register(struct wmi_driver *driver,
1457 struct module *owner)
1458{
1459 driver->driver.owner = owner;
1460 driver->driver.bus = &wmi_bus_type;
1461
1462 return driver_register(&driver->driver);
1463}
1464EXPORT_SYMBOL(__wmi_driver_register);
1465
1466void wmi_driver_unregister(struct wmi_driver *driver)
1467{
1468 driver_unregister(&driver->driver);
1469}
1470EXPORT_SYMBOL(wmi_driver_unregister);
1471
1472static struct platform_driver acpi_wmi_driver = {
1473 .driver = {
1474 .name = "acpi-wmi",
1475 .acpi_match_table = wmi_device_ids,
1476 },
1477 .probe = acpi_wmi_probe,
1478 .remove = acpi_wmi_remove,
1479};
1480
1481static int __init acpi_wmi_init(void)
1482{
1483 int error;
1484
1485 if (acpi_disabled)
1486 return -ENODEV;
1487
1488 error = class_register(&wmi_bus_class);
1489 if (error)
1490 return error;
1491
1492 error = bus_register(&wmi_bus_type);
1493 if (error)
1494 goto err_unreg_class;
1495
1496 error = platform_driver_register(&acpi_wmi_driver);
1497 if (error) {
1498 pr_err("Error loading mapper\n");
1499 goto err_unreg_bus;
1500 }
1501
1502 return 0;
1503
1504err_unreg_bus:
1505 bus_unregister(&wmi_bus_type);
1506
1507err_unreg_class:
1508 class_unregister(&wmi_bus_class);
1509
1510 return error;
1511}
1512
1513static void __exit acpi_wmi_exit(void)
1514{
1515 platform_driver_unregister(&acpi_wmi_driver);
1516 bus_unregister(&wmi_bus_type);
1517 class_unregister(&wmi_bus_class);
1518}
1519
1520subsys_initcall_sync(acpi_wmi_init);
1521module_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);