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