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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/*
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 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
12 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or (at
16 * your option) any later version.
17 *
18 * This program is distributed in the hope that it will be useful, but
19 * WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
21 * General Public License for more details.
22 *
23 * You should have received a copy of the GNU General Public License along
24 * with this program; if not, write to the Free Software Foundation, Inc.,
25 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
26 *
27 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
28 */
29
30#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
31
32#include <linux/kernel.h>
33#include <linux/init.h>
34#include <linux/types.h>
35#include <linux/device.h>
36#include <linux/list.h>
37#include <linux/acpi.h>
38#include <linux/slab.h>
39#include <linux/module.h>
40#include <acpi/acpi_bus.h>
41#include <acpi/acpi_drivers.h>
42
43ACPI_MODULE_NAME("wmi");
44MODULE_AUTHOR("Carlos Corbacho");
45MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
46MODULE_LICENSE("GPL");
47
48#define ACPI_WMI_CLASS "wmi"
49
50static DEFINE_MUTEX(wmi_data_lock);
51static LIST_HEAD(wmi_block_list);
52
53struct guid_block {
54 char guid[16];
55 union {
56 char object_id[2];
57 struct {
58 unsigned char notify_id;
59 unsigned char reserved;
60 };
61 };
62 u8 instance_count;
63 u8 flags;
64};
65
66struct wmi_block {
67 struct list_head list;
68 struct guid_block gblock;
69 acpi_handle handle;
70 wmi_notify_handler handler;
71 void *handler_data;
72 struct device dev;
73};
74
75
76/*
77 * If the GUID data block is marked as expensive, we must enable and
78 * explicitily disable data collection.
79 */
80#define ACPI_WMI_EXPENSIVE 0x1
81#define ACPI_WMI_METHOD 0x2 /* GUID is a method */
82#define ACPI_WMI_STRING 0x4 /* GUID takes & returns a string */
83#define ACPI_WMI_EVENT 0x8 /* GUID is an event */
84
85static bool debug_event;
86module_param(debug_event, bool, 0444);
87MODULE_PARM_DESC(debug_event,
88 "Log WMI Events [0/1]");
89
90static bool debug_dump_wdg;
91module_param(debug_dump_wdg, bool, 0444);
92MODULE_PARM_DESC(debug_dump_wdg,
93 "Dump available WMI interfaces [0/1]");
94
95static int acpi_wmi_remove(struct acpi_device *device, int type);
96static int acpi_wmi_add(struct acpi_device *device);
97static void acpi_wmi_notify(struct acpi_device *device, u32 event);
98
99static const struct acpi_device_id wmi_device_ids[] = {
100 {"PNP0C14", 0},
101 {"pnp0c14", 0},
102 {"", 0},
103};
104MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
105
106static struct acpi_driver acpi_wmi_driver = {
107 .name = "wmi",
108 .class = ACPI_WMI_CLASS,
109 .ids = wmi_device_ids,
110 .ops = {
111 .add = acpi_wmi_add,
112 .remove = acpi_wmi_remove,
113 .notify = acpi_wmi_notify,
114 },
115};
116
117/*
118 * GUID parsing functions
119 */
120
121/**
122 * wmi_parse_hexbyte - Convert a ASCII hex number to a byte
123 * @src: Pointer to at least 2 characters to convert.
124 *
125 * Convert a two character ASCII hex string to a number.
126 *
127 * Return: 0-255 Success, the byte was parsed correctly
128 * -1 Error, an invalid character was supplied
129 */
130static int wmi_parse_hexbyte(const u8 *src)
131{
132 int h;
133 int value;
134
135 /* high part */
136 h = value = hex_to_bin(src[0]);
137 if (value < 0)
138 return -1;
139
140 /* low part */
141 value = hex_to_bin(src[1]);
142 if (value >= 0)
143 return (h << 4) | value;
144 return -1;
145}
146
147/**
148 * wmi_swap_bytes - Rearrange GUID bytes to match GUID binary
149 * @src: Memory block holding binary GUID (16 bytes)
150 * @dest: Memory block to hold byte swapped binary GUID (16 bytes)
151 *
152 * Byte swap a binary GUID to match it's real GUID value
153 */
154static void wmi_swap_bytes(u8 *src, u8 *dest)
155{
156 int i;
157
158 for (i = 0; i <= 3; i++)
159 memcpy(dest + i, src + (3 - i), 1);
160
161 for (i = 0; i <= 1; i++)
162 memcpy(dest + 4 + i, src + (5 - i), 1);
163
164 for (i = 0; i <= 1; i++)
165 memcpy(dest + 6 + i, src + (7 - i), 1);
166
167 memcpy(dest + 8, src + 8, 8);
168}
169
170/**
171 * wmi_parse_guid - Convert GUID from ASCII to binary
172 * @src: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
173 * @dest: Memory block to hold binary GUID (16 bytes)
174 *
175 * N.B. The GUID need not be NULL terminated.
176 *
177 * Return: 'true' @dest contains binary GUID
178 * 'false' @dest contents are undefined
179 */
180static bool wmi_parse_guid(const u8 *src, u8 *dest)
181{
182 static const int size[] = { 4, 2, 2, 2, 6 };
183 int i, j, v;
184
185 if (src[8] != '-' || src[13] != '-' ||
186 src[18] != '-' || src[23] != '-')
187 return false;
188
189 for (j = 0; j < 5; j++, src++) {
190 for (i = 0; i < size[j]; i++, src += 2, *dest++ = v) {
191 v = wmi_parse_hexbyte(src);
192 if (v < 0)
193 return false;
194 }
195 }
196
197 return true;
198}
199
200/*
201 * Convert a raw GUID to the ACII string representation
202 */
203static int wmi_gtoa(const char *in, char *out)
204{
205 int i;
206
207 for (i = 3; i >= 0; i--)
208 out += sprintf(out, "%02X", in[i] & 0xFF);
209
210 out += sprintf(out, "-");
211 out += sprintf(out, "%02X", in[5] & 0xFF);
212 out += sprintf(out, "%02X", in[4] & 0xFF);
213 out += sprintf(out, "-");
214 out += sprintf(out, "%02X", in[7] & 0xFF);
215 out += sprintf(out, "%02X", in[6] & 0xFF);
216 out += sprintf(out, "-");
217 out += sprintf(out, "%02X", in[8] & 0xFF);
218 out += sprintf(out, "%02X", in[9] & 0xFF);
219 out += sprintf(out, "-");
220
221 for (i = 10; i <= 15; i++)
222 out += sprintf(out, "%02X", in[i] & 0xFF);
223
224 *out = '\0';
225 return 0;
226}
227
228static bool find_guid(const char *guid_string, struct wmi_block **out)
229{
230 char tmp[16], guid_input[16];
231 struct wmi_block *wblock;
232 struct guid_block *block;
233 struct list_head *p;
234
235 wmi_parse_guid(guid_string, tmp);
236 wmi_swap_bytes(tmp, guid_input);
237
238 list_for_each(p, &wmi_block_list) {
239 wblock = list_entry(p, struct wmi_block, list);
240 block = &wblock->gblock;
241
242 if (memcmp(block->guid, guid_input, 16) == 0) {
243 if (out)
244 *out = wblock;
245 return 1;
246 }
247 }
248 return 0;
249}
250
251static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable)
252{
253 struct guid_block *block = NULL;
254 char method[5];
255 struct acpi_object_list input;
256 union acpi_object params[1];
257 acpi_status status;
258 acpi_handle handle;
259
260 block = &wblock->gblock;
261 handle = wblock->handle;
262
263 if (!block)
264 return AE_NOT_EXIST;
265
266 input.count = 1;
267 input.pointer = params;
268 params[0].type = ACPI_TYPE_INTEGER;
269 params[0].integer.value = enable;
270
271 snprintf(method, 5, "WE%02X", block->notify_id);
272 status = acpi_evaluate_object(handle, method, &input, NULL);
273
274 if (status != AE_OK && status != AE_NOT_FOUND)
275 return status;
276 else
277 return AE_OK;
278}
279
280/*
281 * Exported WMI functions
282 */
283/**
284 * wmi_evaluate_method - Evaluate a WMI method
285 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
286 * @instance: Instance index
287 * @method_id: Method ID to call
288 * &in: Buffer containing input for the method call
289 * &out: Empty buffer to return the method results
290 *
291 * Call an ACPI-WMI method
292 */
293acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
294u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
295{
296 struct guid_block *block = NULL;
297 struct wmi_block *wblock = NULL;
298 acpi_handle handle;
299 acpi_status status;
300 struct acpi_object_list input;
301 union acpi_object params[3];
302 char method[5] = "WM";
303
304 if (!find_guid(guid_string, &wblock))
305 return AE_ERROR;
306
307 block = &wblock->gblock;
308 handle = wblock->handle;
309
310 if (!(block->flags & ACPI_WMI_METHOD))
311 return AE_BAD_DATA;
312
313 if (block->instance_count < instance)
314 return AE_BAD_PARAMETER;
315
316 input.count = 2;
317 input.pointer = params;
318 params[0].type = ACPI_TYPE_INTEGER;
319 params[0].integer.value = instance;
320 params[1].type = ACPI_TYPE_INTEGER;
321 params[1].integer.value = method_id;
322
323 if (in) {
324 input.count = 3;
325
326 if (block->flags & ACPI_WMI_STRING) {
327 params[2].type = ACPI_TYPE_STRING;
328 } else {
329 params[2].type = ACPI_TYPE_BUFFER;
330 }
331 params[2].buffer.length = in->length;
332 params[2].buffer.pointer = in->pointer;
333 }
334
335 strncat(method, block->object_id, 2);
336
337 status = acpi_evaluate_object(handle, method, &input, out);
338
339 return status;
340}
341EXPORT_SYMBOL_GPL(wmi_evaluate_method);
342
343/**
344 * wmi_query_block - Return contents of a WMI block
345 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
346 * @instance: Instance index
347 * &out: Empty buffer to return the contents of the data block to
348 *
349 * Return the contents of an ACPI-WMI data block to a buffer
350 */
351acpi_status wmi_query_block(const char *guid_string, u8 instance,
352struct acpi_buffer *out)
353{
354 struct guid_block *block = NULL;
355 struct wmi_block *wblock = NULL;
356 acpi_handle handle, wc_handle;
357 acpi_status status, wc_status = AE_ERROR;
358 struct acpi_object_list input, wc_input;
359 union acpi_object wc_params[1], wq_params[1];
360 char method[5];
361 char wc_method[5] = "WC";
362
363 if (!guid_string || !out)
364 return AE_BAD_PARAMETER;
365
366 if (!find_guid(guid_string, &wblock))
367 return AE_ERROR;
368
369 block = &wblock->gblock;
370 handle = wblock->handle;
371
372 if (block->instance_count < instance)
373 return AE_BAD_PARAMETER;
374
375 /* Check GUID is a data block */
376 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
377 return AE_ERROR;
378
379 input.count = 1;
380 input.pointer = wq_params;
381 wq_params[0].type = ACPI_TYPE_INTEGER;
382 wq_params[0].integer.value = instance;
383
384 /*
385 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
386 * enable collection.
387 */
388 if (block->flags & ACPI_WMI_EXPENSIVE) {
389 wc_input.count = 1;
390 wc_input.pointer = wc_params;
391 wc_params[0].type = ACPI_TYPE_INTEGER;
392 wc_params[0].integer.value = 1;
393
394 strncat(wc_method, block->object_id, 2);
395
396 /*
397 * Some GUIDs break the specification by declaring themselves
398 * expensive, but have no corresponding WCxx method. So we
399 * should not fail if this happens.
400 */
401 wc_status = acpi_get_handle(handle, wc_method, &wc_handle);
402 if (ACPI_SUCCESS(wc_status))
403 wc_status = acpi_evaluate_object(handle, wc_method,
404 &wc_input, NULL);
405 }
406
407 strcpy(method, "WQ");
408 strncat(method, block->object_id, 2);
409
410 status = acpi_evaluate_object(handle, method, &input, out);
411
412 /*
413 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
414 * the WQxx method failed - we should disable collection anyway.
415 */
416 if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
417 wc_params[0].integer.value = 0;
418 status = acpi_evaluate_object(handle,
419 wc_method, &wc_input, NULL);
420 }
421
422 return status;
423}
424EXPORT_SYMBOL_GPL(wmi_query_block);
425
426/**
427 * wmi_set_block - Write to a WMI block
428 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
429 * @instance: Instance index
430 * &in: Buffer containing new values for the data block
431 *
432 * Write the contents of the input buffer to an ACPI-WMI data block
433 */
434acpi_status wmi_set_block(const char *guid_string, u8 instance,
435const struct acpi_buffer *in)
436{
437 struct guid_block *block = NULL;
438 struct wmi_block *wblock = NULL;
439 acpi_handle handle;
440 struct acpi_object_list input;
441 union acpi_object params[2];
442 char method[5] = "WS";
443
444 if (!guid_string || !in)
445 return AE_BAD_DATA;
446
447 if (!find_guid(guid_string, &wblock))
448 return AE_ERROR;
449
450 block = &wblock->gblock;
451 handle = wblock->handle;
452
453 if (block->instance_count < instance)
454 return AE_BAD_PARAMETER;
455
456 /* Check GUID is a data block */
457 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
458 return AE_ERROR;
459
460 input.count = 2;
461 input.pointer = params;
462 params[0].type = ACPI_TYPE_INTEGER;
463 params[0].integer.value = instance;
464
465 if (block->flags & ACPI_WMI_STRING) {
466 params[1].type = ACPI_TYPE_STRING;
467 } else {
468 params[1].type = ACPI_TYPE_BUFFER;
469 }
470 params[1].buffer.length = in->length;
471 params[1].buffer.pointer = in->pointer;
472
473 strncat(method, block->object_id, 2);
474
475 return acpi_evaluate_object(handle, method, &input, NULL);
476}
477EXPORT_SYMBOL_GPL(wmi_set_block);
478
479static void wmi_dump_wdg(const struct guid_block *g)
480{
481 char guid_string[37];
482
483 wmi_gtoa(g->guid, guid_string);
484
485 pr_info("%s:\n", guid_string);
486 pr_info("\tobject_id: %c%c\n", g->object_id[0], g->object_id[1]);
487 pr_info("\tnotify_id: %02X\n", g->notify_id);
488 pr_info("\treserved: %02X\n", g->reserved);
489 pr_info("\tinstance_count: %d\n", g->instance_count);
490 pr_info("\tflags: %#x", g->flags);
491 if (g->flags) {
492 if (g->flags & ACPI_WMI_EXPENSIVE)
493 pr_cont(" ACPI_WMI_EXPENSIVE");
494 if (g->flags & ACPI_WMI_METHOD)
495 pr_cont(" ACPI_WMI_METHOD");
496 if (g->flags & ACPI_WMI_STRING)
497 pr_cont(" ACPI_WMI_STRING");
498 if (g->flags & ACPI_WMI_EVENT)
499 pr_cont(" ACPI_WMI_EVENT");
500 }
501 pr_cont("\n");
502
503}
504
505static void wmi_notify_debug(u32 value, void *context)
506{
507 struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
508 union acpi_object *obj;
509 acpi_status status;
510
511 status = wmi_get_event_data(value, &response);
512 if (status != AE_OK) {
513 pr_info("bad event status 0x%x\n", status);
514 return;
515 }
516
517 obj = (union acpi_object *)response.pointer;
518
519 if (!obj)
520 return;
521
522 pr_info("DEBUG Event ");
523 switch(obj->type) {
524 case ACPI_TYPE_BUFFER:
525 pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
526 break;
527 case ACPI_TYPE_STRING:
528 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
529 break;
530 case ACPI_TYPE_INTEGER:
531 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
532 break;
533 case ACPI_TYPE_PACKAGE:
534 pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
535 break;
536 default:
537 pr_cont("object type 0x%X\n", obj->type);
538 }
539 kfree(obj);
540}
541
542/**
543 * wmi_install_notify_handler - Register handler for WMI events
544 * @handler: Function to handle notifications
545 * @data: Data to be returned to handler when event is fired
546 *
547 * Register a handler for events sent to the ACPI-WMI mapper device.
548 */
549acpi_status wmi_install_notify_handler(const char *guid,
550wmi_notify_handler handler, void *data)
551{
552 struct wmi_block *block;
553 acpi_status status = AE_NOT_EXIST;
554 char tmp[16], guid_input[16];
555 struct list_head *p;
556
557 if (!guid || !handler)
558 return AE_BAD_PARAMETER;
559
560 wmi_parse_guid(guid, tmp);
561 wmi_swap_bytes(tmp, guid_input);
562
563 list_for_each(p, &wmi_block_list) {
564 acpi_status wmi_status;
565 block = list_entry(p, struct wmi_block, list);
566
567 if (memcmp(block->gblock.guid, guid_input, 16) == 0) {
568 if (block->handler &&
569 block->handler != wmi_notify_debug)
570 return AE_ALREADY_ACQUIRED;
571
572 block->handler = handler;
573 block->handler_data = data;
574
575 wmi_status = wmi_method_enable(block, 1);
576 if ((wmi_status != AE_OK) ||
577 ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
578 status = wmi_status;
579 }
580 }
581
582 return status;
583}
584EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
585
586/**
587 * wmi_uninstall_notify_handler - Unregister handler for WMI events
588 *
589 * Unregister handler for events sent to the ACPI-WMI mapper device.
590 */
591acpi_status wmi_remove_notify_handler(const char *guid)
592{
593 struct wmi_block *block;
594 acpi_status status = AE_NOT_EXIST;
595 char tmp[16], guid_input[16];
596 struct list_head *p;
597
598 if (!guid)
599 return AE_BAD_PARAMETER;
600
601 wmi_parse_guid(guid, tmp);
602 wmi_swap_bytes(tmp, guid_input);
603
604 list_for_each(p, &wmi_block_list) {
605 acpi_status wmi_status;
606 block = list_entry(p, struct wmi_block, list);
607
608 if (memcmp(block->gblock.guid, guid_input, 16) == 0) {
609 if (!block->handler ||
610 block->handler == wmi_notify_debug)
611 return AE_NULL_ENTRY;
612
613 if (debug_event) {
614 block->handler = wmi_notify_debug;
615 status = AE_OK;
616 } else {
617 wmi_status = wmi_method_enable(block, 0);
618 block->handler = NULL;
619 block->handler_data = NULL;
620 if ((wmi_status != AE_OK) ||
621 ((wmi_status == AE_OK) &&
622 (status == AE_NOT_EXIST)))
623 status = wmi_status;
624 }
625 }
626 }
627
628 return status;
629}
630EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
631
632/**
633 * wmi_get_event_data - Get WMI data associated with an event
634 *
635 * @event: Event to find
636 * @out: Buffer to hold event data. out->pointer should be freed with kfree()
637 *
638 * Returns extra data associated with an event in WMI.
639 */
640acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
641{
642 struct acpi_object_list input;
643 union acpi_object params[1];
644 struct guid_block *gblock;
645 struct wmi_block *wblock;
646 struct list_head *p;
647
648 input.count = 1;
649 input.pointer = params;
650 params[0].type = ACPI_TYPE_INTEGER;
651 params[0].integer.value = event;
652
653 list_for_each(p, &wmi_block_list) {
654 wblock = list_entry(p, struct wmi_block, list);
655 gblock = &wblock->gblock;
656
657 if ((gblock->flags & ACPI_WMI_EVENT) &&
658 (gblock->notify_id == event))
659 return acpi_evaluate_object(wblock->handle, "_WED",
660 &input, out);
661 }
662
663 return AE_NOT_FOUND;
664}
665EXPORT_SYMBOL_GPL(wmi_get_event_data);
666
667/**
668 * wmi_has_guid - Check if a GUID is available
669 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
670 *
671 * Check if a given GUID is defined by _WDG
672 */
673bool wmi_has_guid(const char *guid_string)
674{
675 return find_guid(guid_string, NULL);
676}
677EXPORT_SYMBOL_GPL(wmi_has_guid);
678
679/*
680 * sysfs interface
681 */
682static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
683 char *buf)
684{
685 char guid_string[37];
686 struct wmi_block *wblock;
687
688 wblock = dev_get_drvdata(dev);
689 if (!wblock)
690 return -ENOMEM;
691
692 wmi_gtoa(wblock->gblock.guid, guid_string);
693
694 return sprintf(buf, "wmi:%s\n", guid_string);
695}
696
697static struct device_attribute wmi_dev_attrs[] = {
698 __ATTR_RO(modalias),
699 __ATTR_NULL
700};
701
702static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
703{
704 char guid_string[37];
705
706 struct wmi_block *wblock;
707
708 if (add_uevent_var(env, "MODALIAS="))
709 return -ENOMEM;
710
711 wblock = dev_get_drvdata(dev);
712 if (!wblock)
713 return -ENOMEM;
714
715 wmi_gtoa(wblock->gblock.guid, guid_string);
716
717 strcpy(&env->buf[env->buflen - 1], "wmi:");
718 memcpy(&env->buf[env->buflen - 1 + 4], guid_string, 36);
719 env->buflen += 40;
720
721 return 0;
722}
723
724static void wmi_dev_free(struct device *dev)
725{
726 struct wmi_block *wmi_block = container_of(dev, struct wmi_block, dev);
727
728 kfree(wmi_block);
729}
730
731static struct class wmi_class = {
732 .name = "wmi",
733 .dev_release = wmi_dev_free,
734 .dev_uevent = wmi_dev_uevent,
735 .dev_attrs = wmi_dev_attrs,
736};
737
738static int wmi_create_device(const struct guid_block *gblock,
739 struct wmi_block *wblock, acpi_handle handle)
740{
741 char guid_string[37];
742
743 wblock->dev.class = &wmi_class;
744
745 wmi_gtoa(gblock->guid, guid_string);
746 dev_set_name(&wblock->dev, guid_string);
747
748 dev_set_drvdata(&wblock->dev, wblock);
749
750 return device_register(&wblock->dev);
751}
752
753static void wmi_free_devices(void)
754{
755 struct wmi_block *wblock, *next;
756
757 /* Delete devices for all the GUIDs */
758 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
759 list_del(&wblock->list);
760 if (wblock->dev.class)
761 device_unregister(&wblock->dev);
762 else
763 kfree(wblock);
764 }
765}
766
767static bool guid_already_parsed(const char *guid_string)
768{
769 struct wmi_block *wblock;
770
771 list_for_each_entry(wblock, &wmi_block_list, list)
772 if (memcmp(wblock->gblock.guid, guid_string, 16) == 0)
773 return true;
774
775 return false;
776}
777
778/*
779 * Parse the _WDG method for the GUID data blocks
780 */
781static acpi_status parse_wdg(acpi_handle handle)
782{
783 struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
784 union acpi_object *obj;
785 const struct guid_block *gblock;
786 struct wmi_block *wblock;
787 acpi_status status;
788 int retval;
789 u32 i, total;
790
791 status = acpi_evaluate_object(handle, "_WDG", NULL, &out);
792 if (ACPI_FAILURE(status))
793 return -ENXIO;
794
795 obj = (union acpi_object *) out.pointer;
796 if (!obj)
797 return -ENXIO;
798
799 if (obj->type != ACPI_TYPE_BUFFER) {
800 retval = -ENXIO;
801 goto out_free_pointer;
802 }
803
804 gblock = (const struct guid_block *)obj->buffer.pointer;
805 total = obj->buffer.length / sizeof(struct guid_block);
806
807 for (i = 0; i < total; i++) {
808 if (debug_dump_wdg)
809 wmi_dump_wdg(&gblock[i]);
810
811 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
812 if (!wblock)
813 return AE_NO_MEMORY;
814
815 wblock->handle = handle;
816 wblock->gblock = gblock[i];
817
818 /*
819 Some WMI devices, like those for nVidia hooks, have a
820 duplicate GUID. It's not clear what we should do in this
821 case yet, so for now, we'll just ignore the duplicate
822 for device creation.
823 */
824 if (!guid_already_parsed(gblock[i].guid)) {
825 retval = wmi_create_device(&gblock[i], wblock, handle);
826 if (retval) {
827 wmi_free_devices();
828 goto out_free_pointer;
829 }
830 }
831
832 list_add_tail(&wblock->list, &wmi_block_list);
833
834 if (debug_event) {
835 wblock->handler = wmi_notify_debug;
836 wmi_method_enable(wblock, 1);
837 }
838 }
839
840 retval = 0;
841
842out_free_pointer:
843 kfree(out.pointer);
844
845 return retval;
846}
847
848/*
849 * WMI can have EmbeddedControl access regions. In which case, we just want to
850 * hand these off to the EC driver.
851 */
852static acpi_status
853acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
854 u32 bits, u64 *value,
855 void *handler_context, void *region_context)
856{
857 int result = 0, i = 0;
858 u8 temp = 0;
859
860 if ((address > 0xFF) || !value)
861 return AE_BAD_PARAMETER;
862
863 if (function != ACPI_READ && function != ACPI_WRITE)
864 return AE_BAD_PARAMETER;
865
866 if (bits != 8)
867 return AE_BAD_PARAMETER;
868
869 if (function == ACPI_READ) {
870 result = ec_read(address, &temp);
871 (*value) |= ((u64)temp) << i;
872 } else {
873 temp = 0xff & ((*value) >> i);
874 result = ec_write(address, temp);
875 }
876
877 switch (result) {
878 case -EINVAL:
879 return AE_BAD_PARAMETER;
880 break;
881 case -ENODEV:
882 return AE_NOT_FOUND;
883 break;
884 case -ETIME:
885 return AE_TIME;
886 break;
887 default:
888 return AE_OK;
889 }
890}
891
892static void acpi_wmi_notify(struct acpi_device *device, u32 event)
893{
894 struct guid_block *block;
895 struct wmi_block *wblock;
896 struct list_head *p;
897 char guid_string[37];
898
899 list_for_each(p, &wmi_block_list) {
900 wblock = list_entry(p, struct wmi_block, list);
901 block = &wblock->gblock;
902
903 if ((block->flags & ACPI_WMI_EVENT) &&
904 (block->notify_id == event)) {
905 if (wblock->handler)
906 wblock->handler(event, wblock->handler_data);
907 if (debug_event) {
908 wmi_gtoa(wblock->gblock.guid, guid_string);
909 pr_info("DEBUG Event GUID: %s\n", guid_string);
910 }
911
912 acpi_bus_generate_netlink_event(
913 device->pnp.device_class, dev_name(&device->dev),
914 event, 0);
915 break;
916 }
917 }
918}
919
920static int acpi_wmi_remove(struct acpi_device *device, int type)
921{
922 acpi_remove_address_space_handler(device->handle,
923 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
924 wmi_free_devices();
925
926 return 0;
927}
928
929static int acpi_wmi_add(struct acpi_device *device)
930{
931 acpi_status status;
932 int error;
933
934 status = acpi_install_address_space_handler(device->handle,
935 ACPI_ADR_SPACE_EC,
936 &acpi_wmi_ec_space_handler,
937 NULL, NULL);
938 if (ACPI_FAILURE(status)) {
939 pr_err("Error installing EC region handler\n");
940 return -ENODEV;
941 }
942
943 error = parse_wdg(device->handle);
944 if (error) {
945 acpi_remove_address_space_handler(device->handle,
946 ACPI_ADR_SPACE_EC,
947 &acpi_wmi_ec_space_handler);
948 pr_err("Failed to parse WDG method\n");
949 return error;
950 }
951
952 return 0;
953}
954
955static int __init acpi_wmi_init(void)
956{
957 int error;
958
959 if (acpi_disabled)
960 return -ENODEV;
961
962 error = class_register(&wmi_class);
963 if (error)
964 return error;
965
966 error = acpi_bus_register_driver(&acpi_wmi_driver);
967 if (error) {
968 pr_err("Error loading mapper\n");
969 class_unregister(&wmi_class);
970 return error;
971 }
972
973 pr_info("Mapper loaded\n");
974 return 0;
975}
976
977static void __exit acpi_wmi_exit(void)
978{
979 acpi_bus_unregister_driver(&acpi_wmi_driver);
980 class_unregister(&wmi_class);
981
982 pr_info("Mapper unloaded\n");
983}
984
985subsys_initcall(acpi_wmi_init);
986module_exit(acpi_wmi_exit);