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
38 MODULE_AUTHOR("Carlos Corbacho");
39 MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
40 MODULE_LICENSE("GPL");
41
42 static LIST_HEAD(wmi_block_list);
43
44 struct 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;
56 static_assert(sizeof(typeof_member(struct guid_block, guid)) == 16);
57 static_assert(sizeof(struct guid_block) == 20);
58 static_assert(__alignof__(struct guid_block) == 1);
59
60 enum { /* wmi_block flags */
61 WMI_READ_TAKES_NO_ARGS,
62 WMI_PROBED,
63 };
64
65 struct 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
88 static bool debug_event;
89 module_param(debug_event, bool, 0444);
90 MODULE_PARM_DESC(debug_event,
91 "Log WMI Events [0/1]");
92
93 static bool debug_dump_wdg;
94 module_param(debug_dump_wdg, bool, 0444);
95 MODULE_PARM_DESC(debug_dump_wdg,
96 "Dump available WMI interfaces [0/1]");
97
98 static const struct acpi_device_id wmi_device_ids[] = {
99 {"PNP0C14", 0},
100 {"pnp0c14", 0},
101 { }
102 };
103 MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
104
105 /* allow duplicate GUIDs as these device drivers use struct wmi_driver */
106 static 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
find_guid(const char * guid_string,struct wmi_block ** out)116 static 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
guid_parse_and_compare(const char * string,const guid_t * guid)139 static bool guid_parse_and_compare(const char *string, const guid_t *guid)
140 {
141 guid_t guid_input;
142
143 if (guid_parse(string, &guid_input))
144 return false;
145
146 return guid_equal(&guid_input, guid);
147 }
148
find_guid_context(struct wmi_block * wblock,struct wmi_driver * wdriver)149 static const void *find_guid_context(struct wmi_block *wblock,
150 struct wmi_driver *wdriver)
151 {
152 const struct wmi_device_id *id;
153
154 id = wdriver->id_table;
155 if (!id)
156 return NULL;
157
158 while (*id->guid_string) {
159 if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid))
160 return id->context;
161 id++;
162 }
163 return NULL;
164 }
165
get_subobj_info(acpi_handle handle,const char * pathname,struct acpi_device_info ** info)166 static int get_subobj_info(acpi_handle handle, const char *pathname,
167 struct acpi_device_info **info)
168 {
169 struct acpi_device_info *dummy_info, **info_ptr;
170 acpi_handle subobj_handle;
171 acpi_status status;
172
173 status = acpi_get_handle(handle, (char *)pathname, &subobj_handle);
174 if (status == AE_NOT_FOUND)
175 return -ENOENT;
176 else if (ACPI_FAILURE(status))
177 return -EIO;
178
179 info_ptr = info ? info : &dummy_info;
180 status = acpi_get_object_info(subobj_handle, info_ptr);
181 if (ACPI_FAILURE(status))
182 return -EIO;
183
184 if (!info)
185 kfree(dummy_info);
186
187 return 0;
188 }
189
wmi_method_enable(struct wmi_block * wblock,bool enable)190 static acpi_status wmi_method_enable(struct wmi_block *wblock, bool enable)
191 {
192 struct guid_block *block;
193 char method[5];
194 acpi_status status;
195 acpi_handle handle;
196
197 block = &wblock->gblock;
198 handle = wblock->acpi_device->handle;
199
200 snprintf(method, 5, "WE%02X", block->notify_id);
201 status = acpi_execute_simple_method(handle, method, enable);
202 if (status == AE_NOT_FOUND)
203 return AE_OK;
204
205 return status;
206 }
207
208 #define WMI_ACPI_METHOD_NAME_SIZE 5
209
get_acpi_method_name(const struct wmi_block * wblock,const char method,char buffer[static WMI_ACPI_METHOD_NAME_SIZE])210 static inline void get_acpi_method_name(const struct wmi_block *wblock,
211 const char method,
212 char buffer[static WMI_ACPI_METHOD_NAME_SIZE])
213 {
214 static_assert(ARRAY_SIZE(wblock->gblock.object_id) == 2);
215 static_assert(WMI_ACPI_METHOD_NAME_SIZE >= 5);
216
217 buffer[0] = 'W';
218 buffer[1] = method;
219 buffer[2] = wblock->gblock.object_id[0];
220 buffer[3] = wblock->gblock.object_id[1];
221 buffer[4] = '\0';
222 }
223
get_param_acpi_type(const struct wmi_block * wblock)224 static inline acpi_object_type get_param_acpi_type(const struct wmi_block *wblock)
225 {
226 if (wblock->gblock.flags & ACPI_WMI_STRING)
227 return ACPI_TYPE_STRING;
228 else
229 return ACPI_TYPE_BUFFER;
230 }
231
get_event_data(const struct wmi_block * wblock,struct acpi_buffer * out)232 static acpi_status get_event_data(const struct wmi_block *wblock, struct acpi_buffer *out)
233 {
234 union acpi_object param = {
235 .integer = {
236 .type = ACPI_TYPE_INTEGER,
237 .value = wblock->gblock.notify_id,
238 }
239 };
240 struct acpi_object_list input = {
241 .count = 1,
242 .pointer = ¶m,
243 };
244
245 return acpi_evaluate_object(wblock->acpi_device->handle, "_WED", &input, out);
246 }
247
248 /*
249 * Exported WMI functions
250 */
251
252 /**
253 * set_required_buffer_size - Sets the buffer size needed for performing IOCTL
254 * @wdev: A wmi bus device from a driver
255 * @length: Required buffer size
256 *
257 * Allocates memory needed for buffer, stores the buffer size in that memory.
258 *
259 * Return: 0 on success or a negative error code for failure.
260 */
set_required_buffer_size(struct wmi_device * wdev,u64 length)261 int set_required_buffer_size(struct wmi_device *wdev, u64 length)
262 {
263 struct wmi_block *wblock;
264
265 wblock = container_of(wdev, struct wmi_block, dev);
266 wblock->req_buf_size = length;
267
268 return 0;
269 }
270 EXPORT_SYMBOL_GPL(set_required_buffer_size);
271
272 /**
273 * wmi_instance_count - Get number of WMI object instances
274 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
275 *
276 * Get the number of WMI object instances.
277 *
278 * Returns: Number of WMI object instances or negative error code.
279 */
wmi_instance_count(const char * guid_string)280 int wmi_instance_count(const char *guid_string)
281 {
282 struct wmi_block *wblock;
283 acpi_status status;
284
285 status = find_guid(guid_string, &wblock);
286 if (ACPI_FAILURE(status)) {
287 if (status == AE_BAD_PARAMETER)
288 return -EINVAL;
289
290 return -ENODEV;
291 }
292
293 return wmidev_instance_count(&wblock->dev);
294 }
295 EXPORT_SYMBOL_GPL(wmi_instance_count);
296
297 /**
298 * wmidev_instance_count - Get number of WMI object instances
299 * @wdev: A wmi bus device from a driver
300 *
301 * Get the number of WMI object instances.
302 *
303 * Returns: Number of WMI object instances.
304 */
wmidev_instance_count(struct wmi_device * wdev)305 u8 wmidev_instance_count(struct wmi_device *wdev)
306 {
307 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
308
309 return wblock->gblock.instance_count;
310 }
311 EXPORT_SYMBOL_GPL(wmidev_instance_count);
312
313 /**
314 * wmi_evaluate_method - Evaluate a WMI method (deprecated)
315 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
316 * @instance: Instance index
317 * @method_id: Method ID to call
318 * @in: Buffer containing input for the method call
319 * @out: Empty buffer to return the method results
320 *
321 * Call an ACPI-WMI method, the caller must free @out.
322 *
323 * Return: acpi_status signaling success or error.
324 */
wmi_evaluate_method(const char * guid_string,u8 instance,u32 method_id,const struct acpi_buffer * in,struct acpi_buffer * out)325 acpi_status wmi_evaluate_method(const char *guid_string, u8 instance, u32 method_id,
326 const struct acpi_buffer *in, struct acpi_buffer *out)
327 {
328 struct wmi_block *wblock = NULL;
329 acpi_status status;
330
331 status = find_guid(guid_string, &wblock);
332 if (ACPI_FAILURE(status))
333 return status;
334
335 return wmidev_evaluate_method(&wblock->dev, instance, method_id,
336 in, out);
337 }
338 EXPORT_SYMBOL_GPL(wmi_evaluate_method);
339
340 /**
341 * wmidev_evaluate_method - Evaluate a WMI method
342 * @wdev: A wmi bus device from a driver
343 * @instance: Instance index
344 * @method_id: Method ID to call
345 * @in: Buffer containing input for the method call
346 * @out: Empty buffer to return the method results
347 *
348 * Call an ACPI-WMI method, the caller must free @out.
349 *
350 * Return: acpi_status signaling success or error.
351 */
wmidev_evaluate_method(struct wmi_device * wdev,u8 instance,u32 method_id,const struct acpi_buffer * in,struct acpi_buffer * out)352 acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance, u32 method_id,
353 const struct acpi_buffer *in, struct acpi_buffer *out)
354 {
355 struct guid_block *block;
356 struct wmi_block *wblock;
357 acpi_handle handle;
358 struct acpi_object_list input;
359 union acpi_object params[3];
360 char method[WMI_ACPI_METHOD_NAME_SIZE];
361
362 wblock = container_of(wdev, struct wmi_block, dev);
363 block = &wblock->gblock;
364 handle = wblock->acpi_device->handle;
365
366 if (!(block->flags & ACPI_WMI_METHOD))
367 return AE_BAD_DATA;
368
369 if (block->instance_count <= instance)
370 return AE_BAD_PARAMETER;
371
372 input.count = 2;
373 input.pointer = params;
374 params[0].type = ACPI_TYPE_INTEGER;
375 params[0].integer.value = instance;
376 params[1].type = ACPI_TYPE_INTEGER;
377 params[1].integer.value = method_id;
378
379 if (in) {
380 input.count = 3;
381
382 params[2].type = get_param_acpi_type(wblock);
383 params[2].buffer.length = in->length;
384 params[2].buffer.pointer = in->pointer;
385 }
386
387 get_acpi_method_name(wblock, 'M', method);
388
389 return acpi_evaluate_object(handle, method, &input, out);
390 }
391 EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
392
__query_block(struct wmi_block * wblock,u8 instance,struct acpi_buffer * out)393 static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
394 struct acpi_buffer *out)
395 {
396 struct guid_block *block;
397 acpi_handle handle;
398 acpi_status status, wc_status = AE_ERROR;
399 struct acpi_object_list input;
400 union acpi_object wq_params[1];
401 char wc_method[WMI_ACPI_METHOD_NAME_SIZE];
402 char method[WMI_ACPI_METHOD_NAME_SIZE];
403
404 if (!out)
405 return AE_BAD_PARAMETER;
406
407 block = &wblock->gblock;
408 handle = wblock->acpi_device->handle;
409
410 if (block->instance_count <= instance)
411 return AE_BAD_PARAMETER;
412
413 /* Check GUID is a data block */
414 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
415 return AE_ERROR;
416
417 input.count = 1;
418 input.pointer = wq_params;
419 wq_params[0].type = ACPI_TYPE_INTEGER;
420 wq_params[0].integer.value = instance;
421
422 if (instance == 0 && test_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags))
423 input.count = 0;
424
425 /*
426 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
427 * enable collection.
428 */
429 if (block->flags & ACPI_WMI_EXPENSIVE) {
430 get_acpi_method_name(wblock, 'C', wc_method);
431
432 /*
433 * Some GUIDs break the specification by declaring themselves
434 * expensive, but have no corresponding WCxx method. So we
435 * should not fail if this happens.
436 */
437 wc_status = acpi_execute_simple_method(handle, wc_method, 1);
438 }
439
440 get_acpi_method_name(wblock, 'Q', method);
441 status = acpi_evaluate_object(handle, method, &input, out);
442
443 /*
444 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
445 * the WQxx method failed - we should disable collection anyway.
446 */
447 if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
448 /*
449 * Ignore whether this WCxx call succeeds or not since
450 * the previously executed WQxx method call might have
451 * succeeded, and returning the failing status code
452 * of this call would throw away the result of the WQxx
453 * call, potentially leaking memory.
454 */
455 acpi_execute_simple_method(handle, wc_method, 0);
456 }
457
458 return status;
459 }
460
461 /**
462 * wmi_query_block - Return contents of a WMI block (deprecated)
463 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
464 * @instance: Instance index
465 * @out: Empty buffer to return the contents of the data block to
466 *
467 * Query a ACPI-WMI block, the caller must free @out.
468 *
469 * Return: ACPI object containing the content of the WMI block.
470 */
wmi_query_block(const char * guid_string,u8 instance,struct acpi_buffer * out)471 acpi_status wmi_query_block(const char *guid_string, u8 instance,
472 struct acpi_buffer *out)
473 {
474 struct wmi_block *wblock;
475 acpi_status status;
476
477 status = find_guid(guid_string, &wblock);
478 if (ACPI_FAILURE(status))
479 return status;
480
481 return __query_block(wblock, instance, out);
482 }
483 EXPORT_SYMBOL_GPL(wmi_query_block);
484
485 /**
486 * wmidev_block_query - Return contents of a WMI block
487 * @wdev: A wmi bus device from a driver
488 * @instance: Instance index
489 *
490 * Query an ACPI-WMI block, the caller must free the result.
491 *
492 * Return: ACPI object containing the content of the WMI block.
493 */
wmidev_block_query(struct wmi_device * wdev,u8 instance)494 union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
495 {
496 struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
497 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
498
499 if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
500 return NULL;
501
502 return out.pointer;
503 }
504 EXPORT_SYMBOL_GPL(wmidev_block_query);
505
506 /**
507 * wmi_set_block - Write to a WMI block (deprecated)
508 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
509 * @instance: Instance index
510 * @in: Buffer containing new values for the data block
511 *
512 * Write the contents of the input buffer to an ACPI-WMI data block.
513 *
514 * Return: acpi_status signaling success or error.
515 */
wmi_set_block(const char * guid_string,u8 instance,const struct acpi_buffer * in)516 acpi_status wmi_set_block(const char *guid_string, u8 instance,
517 const struct acpi_buffer *in)
518 {
519 struct wmi_block *wblock = NULL;
520 struct guid_block *block;
521 acpi_handle handle;
522 struct acpi_object_list input;
523 union acpi_object params[2];
524 char method[WMI_ACPI_METHOD_NAME_SIZE];
525 acpi_status status;
526
527 if (!in)
528 return AE_BAD_DATA;
529
530 status = find_guid(guid_string, &wblock);
531 if (ACPI_FAILURE(status))
532 return status;
533
534 block = &wblock->gblock;
535 handle = wblock->acpi_device->handle;
536
537 if (block->instance_count <= instance)
538 return AE_BAD_PARAMETER;
539
540 /* Check GUID is a data block */
541 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
542 return AE_ERROR;
543
544 input.count = 2;
545 input.pointer = params;
546 params[0].type = ACPI_TYPE_INTEGER;
547 params[0].integer.value = instance;
548 params[1].type = get_param_acpi_type(wblock);
549 params[1].buffer.length = in->length;
550 params[1].buffer.pointer = in->pointer;
551
552 get_acpi_method_name(wblock, 'S', method);
553
554 return acpi_evaluate_object(handle, method, &input, NULL);
555 }
556 EXPORT_SYMBOL_GPL(wmi_set_block);
557
wmi_dump_wdg(const struct guid_block * g)558 static void wmi_dump_wdg(const struct guid_block *g)
559 {
560 pr_info("%pUL:\n", &g->guid);
561 if (g->flags & ACPI_WMI_EVENT)
562 pr_info("\tnotify_id: 0x%02X\n", g->notify_id);
563 else
564 pr_info("\tobject_id: %2pE\n", g->object_id);
565 pr_info("\tinstance_count: %d\n", g->instance_count);
566 pr_info("\tflags: %#x", g->flags);
567 if (g->flags) {
568 if (g->flags & ACPI_WMI_EXPENSIVE)
569 pr_cont(" ACPI_WMI_EXPENSIVE");
570 if (g->flags & ACPI_WMI_METHOD)
571 pr_cont(" ACPI_WMI_METHOD");
572 if (g->flags & ACPI_WMI_STRING)
573 pr_cont(" ACPI_WMI_STRING");
574 if (g->flags & ACPI_WMI_EVENT)
575 pr_cont(" ACPI_WMI_EVENT");
576 }
577 pr_cont("\n");
578
579 }
580
wmi_notify_debug(u32 value,void * context)581 static void wmi_notify_debug(u32 value, void *context)
582 {
583 struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
584 union acpi_object *obj;
585 acpi_status status;
586
587 status = wmi_get_event_data(value, &response);
588 if (status != AE_OK) {
589 pr_info("bad event status 0x%x\n", status);
590 return;
591 }
592
593 obj = response.pointer;
594 if (!obj)
595 return;
596
597 pr_info("DEBUG: event 0x%02X ", value);
598 switch (obj->type) {
599 case ACPI_TYPE_BUFFER:
600 pr_cont("BUFFER_TYPE - length %u\n", obj->buffer.length);
601 break;
602 case ACPI_TYPE_STRING:
603 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
604 break;
605 case ACPI_TYPE_INTEGER:
606 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
607 break;
608 case ACPI_TYPE_PACKAGE:
609 pr_cont("PACKAGE_TYPE - %u elements\n", obj->package.count);
610 break;
611 default:
612 pr_cont("object type 0x%X\n", obj->type);
613 }
614 kfree(obj);
615 }
616
617 /**
618 * wmi_install_notify_handler - Register handler for WMI events (deprecated)
619 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
620 * @handler: Function to handle notifications
621 * @data: Data to be returned to handler when event is fired
622 *
623 * Register a handler for events sent to the ACPI-WMI mapper device.
624 *
625 * Return: acpi_status signaling success or error.
626 */
wmi_install_notify_handler(const char * guid,wmi_notify_handler handler,void * data)627 acpi_status wmi_install_notify_handler(const char *guid,
628 wmi_notify_handler handler,
629 void *data)
630 {
631 struct wmi_block *block;
632 acpi_status status = AE_NOT_EXIST;
633 guid_t guid_input;
634
635 if (!guid || !handler)
636 return AE_BAD_PARAMETER;
637
638 if (guid_parse(guid, &guid_input))
639 return AE_BAD_PARAMETER;
640
641 list_for_each_entry(block, &wmi_block_list, list) {
642 acpi_status wmi_status;
643
644 if (guid_equal(&block->gblock.guid, &guid_input)) {
645 if (block->handler &&
646 block->handler != wmi_notify_debug)
647 return AE_ALREADY_ACQUIRED;
648
649 block->handler = handler;
650 block->handler_data = data;
651
652 wmi_status = wmi_method_enable(block, true);
653 if ((wmi_status != AE_OK) ||
654 ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
655 status = wmi_status;
656 }
657 }
658
659 return status;
660 }
661 EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
662
663 /**
664 * wmi_remove_notify_handler - Unregister handler for WMI events (deprecated)
665 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
666 *
667 * Unregister handler for events sent to the ACPI-WMI mapper device.
668 *
669 * Return: acpi_status signaling success or error.
670 */
wmi_remove_notify_handler(const char * guid)671 acpi_status wmi_remove_notify_handler(const char *guid)
672 {
673 struct wmi_block *block;
674 acpi_status status = AE_NOT_EXIST;
675 guid_t guid_input;
676
677 if (!guid)
678 return AE_BAD_PARAMETER;
679
680 if (guid_parse(guid, &guid_input))
681 return AE_BAD_PARAMETER;
682
683 list_for_each_entry(block, &wmi_block_list, list) {
684 acpi_status wmi_status;
685
686 if (guid_equal(&block->gblock.guid, &guid_input)) {
687 if (!block->handler ||
688 block->handler == wmi_notify_debug)
689 return AE_NULL_ENTRY;
690
691 if (debug_event) {
692 block->handler = wmi_notify_debug;
693 status = AE_OK;
694 } else {
695 wmi_status = wmi_method_enable(block, false);
696 block->handler = NULL;
697 block->handler_data = NULL;
698 if ((wmi_status != AE_OK) ||
699 ((wmi_status == AE_OK) &&
700 (status == AE_NOT_EXIST)))
701 status = wmi_status;
702 }
703 }
704 }
705
706 return status;
707 }
708 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
709
710 /**
711 * wmi_get_event_data - Get WMI data associated with an event (deprecated)
712 *
713 * @event: Event to find
714 * @out: Buffer to hold event data
715 *
716 * Get extra data associated with an WMI event, the caller needs to free @out.
717 *
718 * Return: acpi_status signaling success or error.
719 */
wmi_get_event_data(u32 event,struct acpi_buffer * out)720 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
721 {
722 struct wmi_block *wblock;
723
724 list_for_each_entry(wblock, &wmi_block_list, list) {
725 struct guid_block *gblock = &wblock->gblock;
726
727 if ((gblock->flags & ACPI_WMI_EVENT) && gblock->notify_id == event)
728 return get_event_data(wblock, out);
729 }
730
731 return AE_NOT_FOUND;
732 }
733 EXPORT_SYMBOL_GPL(wmi_get_event_data);
734
735 /**
736 * wmi_has_guid - Check if a GUID is available
737 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
738 *
739 * Check if a given GUID is defined by _WDG.
740 *
741 * Return: True if GUID is available, false otherwise.
742 */
wmi_has_guid(const char * guid_string)743 bool wmi_has_guid(const char *guid_string)
744 {
745 return ACPI_SUCCESS(find_guid(guid_string, NULL));
746 }
747 EXPORT_SYMBOL_GPL(wmi_has_guid);
748
749 /**
750 * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID (deprecated)
751 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
752 *
753 * Find the _UID of ACPI device associated with this WMI GUID.
754 *
755 * Return: The ACPI _UID field value or NULL if the WMI GUID was not found.
756 */
wmi_get_acpi_device_uid(const char * guid_string)757 char *wmi_get_acpi_device_uid(const char *guid_string)
758 {
759 struct wmi_block *wblock = NULL;
760 acpi_status status;
761
762 status = find_guid(guid_string, &wblock);
763 if (ACPI_FAILURE(status))
764 return NULL;
765
766 return acpi_device_uid(wblock->acpi_device);
767 }
768 EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
769
770 #define dev_to_wblock(__dev) container_of_const(__dev, struct wmi_block, dev.dev)
771 #define dev_to_wdev(__dev) container_of_const(__dev, struct wmi_device, dev)
772
drv_to_wdrv(struct device_driver * drv)773 static inline struct wmi_driver *drv_to_wdrv(struct device_driver *drv)
774 {
775 return container_of(drv, struct wmi_driver, driver);
776 }
777
778 /*
779 * sysfs interface
780 */
modalias_show(struct device * dev,struct device_attribute * attr,char * buf)781 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
782 char *buf)
783 {
784 struct wmi_block *wblock = dev_to_wblock(dev);
785
786 return sysfs_emit(buf, "wmi:%pUL\n", &wblock->gblock.guid);
787 }
788 static DEVICE_ATTR_RO(modalias);
789
guid_show(struct device * dev,struct device_attribute * attr,char * buf)790 static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
791 char *buf)
792 {
793 struct wmi_block *wblock = dev_to_wblock(dev);
794
795 return sysfs_emit(buf, "%pUL\n", &wblock->gblock.guid);
796 }
797 static DEVICE_ATTR_RO(guid);
798
instance_count_show(struct device * dev,struct device_attribute * attr,char * buf)799 static ssize_t instance_count_show(struct device *dev,
800 struct device_attribute *attr, char *buf)
801 {
802 struct wmi_block *wblock = dev_to_wblock(dev);
803
804 return sysfs_emit(buf, "%d\n", (int)wblock->gblock.instance_count);
805 }
806 static DEVICE_ATTR_RO(instance_count);
807
expensive_show(struct device * dev,struct device_attribute * attr,char * buf)808 static ssize_t expensive_show(struct device *dev,
809 struct device_attribute *attr, char *buf)
810 {
811 struct wmi_block *wblock = dev_to_wblock(dev);
812
813 return sysfs_emit(buf, "%d\n",
814 (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
815 }
816 static DEVICE_ATTR_RO(expensive);
817
818 static struct attribute *wmi_attrs[] = {
819 &dev_attr_modalias.attr,
820 &dev_attr_guid.attr,
821 &dev_attr_instance_count.attr,
822 &dev_attr_expensive.attr,
823 NULL
824 };
825 ATTRIBUTE_GROUPS(wmi);
826
notify_id_show(struct device * dev,struct device_attribute * attr,char * buf)827 static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
828 char *buf)
829 {
830 struct wmi_block *wblock = dev_to_wblock(dev);
831
832 return sysfs_emit(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
833 }
834 static DEVICE_ATTR_RO(notify_id);
835
836 static struct attribute *wmi_event_attrs[] = {
837 &dev_attr_notify_id.attr,
838 NULL
839 };
840 ATTRIBUTE_GROUPS(wmi_event);
841
object_id_show(struct device * dev,struct device_attribute * attr,char * buf)842 static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
843 char *buf)
844 {
845 struct wmi_block *wblock = dev_to_wblock(dev);
846
847 return sysfs_emit(buf, "%c%c\n", wblock->gblock.object_id[0],
848 wblock->gblock.object_id[1]);
849 }
850 static DEVICE_ATTR_RO(object_id);
851
setable_show(struct device * dev,struct device_attribute * attr,char * buf)852 static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
853 char *buf)
854 {
855 struct wmi_device *wdev = dev_to_wdev(dev);
856
857 return sysfs_emit(buf, "%d\n", (int)wdev->setable);
858 }
859 static DEVICE_ATTR_RO(setable);
860
861 static struct attribute *wmi_data_attrs[] = {
862 &dev_attr_object_id.attr,
863 &dev_attr_setable.attr,
864 NULL
865 };
866 ATTRIBUTE_GROUPS(wmi_data);
867
868 static struct attribute *wmi_method_attrs[] = {
869 &dev_attr_object_id.attr,
870 NULL
871 };
872 ATTRIBUTE_GROUPS(wmi_method);
873
wmi_dev_uevent(const struct device * dev,struct kobj_uevent_env * env)874 static int wmi_dev_uevent(const struct device *dev, struct kobj_uevent_env *env)
875 {
876 const struct wmi_block *wblock = dev_to_wblock(dev);
877
878 if (add_uevent_var(env, "MODALIAS=wmi:%pUL", &wblock->gblock.guid))
879 return -ENOMEM;
880
881 if (add_uevent_var(env, "WMI_GUID=%pUL", &wblock->gblock.guid))
882 return -ENOMEM;
883
884 return 0;
885 }
886
wmi_dev_release(struct device * dev)887 static void wmi_dev_release(struct device *dev)
888 {
889 struct wmi_block *wblock = dev_to_wblock(dev);
890
891 kfree(wblock);
892 }
893
wmi_dev_match(struct device * dev,struct device_driver * driver)894 static int wmi_dev_match(struct device *dev, struct device_driver *driver)
895 {
896 struct wmi_driver *wmi_driver = drv_to_wdrv(driver);
897 struct wmi_block *wblock = dev_to_wblock(dev);
898 const struct wmi_device_id *id = wmi_driver->id_table;
899
900 if (id == NULL)
901 return 0;
902
903 while (*id->guid_string) {
904 if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid))
905 return 1;
906
907 id++;
908 }
909
910 return 0;
911 }
wmi_char_open(struct inode * inode,struct file * filp)912 static int wmi_char_open(struct inode *inode, struct file *filp)
913 {
914 /*
915 * The miscdevice already stores a pointer to itself
916 * inside filp->private_data
917 */
918 struct wmi_block *wblock = container_of(filp->private_data, struct wmi_block, char_dev);
919
920 filp->private_data = wblock;
921
922 return nonseekable_open(inode, filp);
923 }
924
wmi_char_read(struct file * filp,char __user * buffer,size_t length,loff_t * offset)925 static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
926 size_t length, loff_t *offset)
927 {
928 struct wmi_block *wblock = filp->private_data;
929
930 return simple_read_from_buffer(buffer, length, offset,
931 &wblock->req_buf_size,
932 sizeof(wblock->req_buf_size));
933 }
934
wmi_ioctl(struct file * filp,unsigned int cmd,unsigned long arg)935 static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
936 {
937 struct wmi_ioctl_buffer __user *input =
938 (struct wmi_ioctl_buffer __user *) arg;
939 struct wmi_block *wblock = filp->private_data;
940 struct wmi_ioctl_buffer *buf;
941 struct wmi_driver *wdriver;
942 int ret;
943
944 if (_IOC_TYPE(cmd) != WMI_IOC)
945 return -ENOTTY;
946
947 /* make sure we're not calling a higher instance than exists*/
948 if (_IOC_NR(cmd) >= wblock->gblock.instance_count)
949 return -EINVAL;
950
951 mutex_lock(&wblock->char_mutex);
952 buf = wblock->handler_data;
953 if (get_user(buf->length, &input->length)) {
954 dev_dbg(&wblock->dev.dev, "Read length from user failed\n");
955 ret = -EFAULT;
956 goto out_ioctl;
957 }
958 /* if it's too small, abort */
959 if (buf->length < wblock->req_buf_size) {
960 dev_err(&wblock->dev.dev,
961 "Buffer %lld too small, need at least %lld\n",
962 buf->length, wblock->req_buf_size);
963 ret = -EINVAL;
964 goto out_ioctl;
965 }
966 /* if it's too big, warn, driver will only use what is needed */
967 if (buf->length > wblock->req_buf_size)
968 dev_warn(&wblock->dev.dev,
969 "Buffer %lld is bigger than required %lld\n",
970 buf->length, wblock->req_buf_size);
971
972 /* copy the structure from userspace */
973 if (copy_from_user(buf, input, wblock->req_buf_size)) {
974 dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n",
975 wblock->req_buf_size);
976 ret = -EFAULT;
977 goto out_ioctl;
978 }
979
980 /* let the driver do any filtering and do the call */
981 wdriver = drv_to_wdrv(wblock->dev.dev.driver);
982 if (!try_module_get(wdriver->driver.owner)) {
983 ret = -EBUSY;
984 goto out_ioctl;
985 }
986 ret = wdriver->filter_callback(&wblock->dev, cmd, buf);
987 module_put(wdriver->driver.owner);
988 if (ret)
989 goto out_ioctl;
990
991 /* return the result (only up to our internal buffer size) */
992 if (copy_to_user(input, buf, wblock->req_buf_size)) {
993 dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n",
994 wblock->req_buf_size);
995 ret = -EFAULT;
996 }
997
998 out_ioctl:
999 mutex_unlock(&wblock->char_mutex);
1000 return ret;
1001 }
1002
1003 static const struct file_operations wmi_fops = {
1004 .owner = THIS_MODULE,
1005 .read = wmi_char_read,
1006 .open = wmi_char_open,
1007 .unlocked_ioctl = wmi_ioctl,
1008 .compat_ioctl = compat_ptr_ioctl,
1009 };
1010
wmi_dev_probe(struct device * dev)1011 static int wmi_dev_probe(struct device *dev)
1012 {
1013 struct wmi_block *wblock = dev_to_wblock(dev);
1014 struct wmi_driver *wdriver = drv_to_wdrv(dev->driver);
1015 int ret = 0;
1016 char *buf;
1017
1018 if (ACPI_FAILURE(wmi_method_enable(wblock, true)))
1019 dev_warn(dev, "failed to enable device -- probing anyway\n");
1020
1021 if (wdriver->probe) {
1022 ret = wdriver->probe(dev_to_wdev(dev),
1023 find_guid_context(wblock, wdriver));
1024 if (ret != 0)
1025 goto probe_failure;
1026 }
1027
1028 /* driver wants a character device made */
1029 if (wdriver->filter_callback) {
1030 /* check that required buffer size declared by driver or MOF */
1031 if (!wblock->req_buf_size) {
1032 dev_err(&wblock->dev.dev,
1033 "Required buffer size not set\n");
1034 ret = -EINVAL;
1035 goto probe_failure;
1036 }
1037
1038 wblock->handler_data = kmalloc(wblock->req_buf_size,
1039 GFP_KERNEL);
1040 if (!wblock->handler_data) {
1041 ret = -ENOMEM;
1042 goto probe_failure;
1043 }
1044
1045 buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name);
1046 if (!buf) {
1047 ret = -ENOMEM;
1048 goto probe_string_failure;
1049 }
1050 wblock->char_dev.minor = MISC_DYNAMIC_MINOR;
1051 wblock->char_dev.name = buf;
1052 wblock->char_dev.fops = &wmi_fops;
1053 wblock->char_dev.mode = 0444;
1054 ret = misc_register(&wblock->char_dev);
1055 if (ret) {
1056 dev_warn(dev, "failed to register char dev: %d\n", ret);
1057 ret = -ENOMEM;
1058 goto probe_misc_failure;
1059 }
1060 }
1061
1062 set_bit(WMI_PROBED, &wblock->flags);
1063 return 0;
1064
1065 probe_misc_failure:
1066 kfree(buf);
1067 probe_string_failure:
1068 kfree(wblock->handler_data);
1069 probe_failure:
1070 if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
1071 dev_warn(dev, "failed to disable device\n");
1072 return ret;
1073 }
1074
wmi_dev_remove(struct device * dev)1075 static void wmi_dev_remove(struct device *dev)
1076 {
1077 struct wmi_block *wblock = dev_to_wblock(dev);
1078 struct wmi_driver *wdriver = drv_to_wdrv(dev->driver);
1079
1080 clear_bit(WMI_PROBED, &wblock->flags);
1081
1082 if (wdriver->filter_callback) {
1083 misc_deregister(&wblock->char_dev);
1084 kfree(wblock->char_dev.name);
1085 kfree(wblock->handler_data);
1086 }
1087
1088 if (wdriver->remove)
1089 wdriver->remove(dev_to_wdev(dev));
1090
1091 if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
1092 dev_warn(dev, "failed to disable device\n");
1093 }
1094
1095 static struct class wmi_bus_class = {
1096 .name = "wmi_bus",
1097 };
1098
1099 static struct bus_type wmi_bus_type = {
1100 .name = "wmi",
1101 .dev_groups = wmi_groups,
1102 .match = wmi_dev_match,
1103 .uevent = wmi_dev_uevent,
1104 .probe = wmi_dev_probe,
1105 .remove = wmi_dev_remove,
1106 };
1107
1108 static const struct device_type wmi_type_event = {
1109 .name = "event",
1110 .groups = wmi_event_groups,
1111 .release = wmi_dev_release,
1112 };
1113
1114 static const struct device_type wmi_type_method = {
1115 .name = "method",
1116 .groups = wmi_method_groups,
1117 .release = wmi_dev_release,
1118 };
1119
1120 static const struct device_type wmi_type_data = {
1121 .name = "data",
1122 .groups = wmi_data_groups,
1123 .release = wmi_dev_release,
1124 };
1125
1126 /*
1127 * _WDG is a static list that is only parsed at startup,
1128 * so it's safe to count entries without extra protection.
1129 */
guid_count(const guid_t * guid)1130 static int guid_count(const guid_t *guid)
1131 {
1132 struct wmi_block *wblock;
1133 int count = 0;
1134
1135 list_for_each_entry(wblock, &wmi_block_list, list) {
1136 if (guid_equal(&wblock->gblock.guid, guid))
1137 count++;
1138 }
1139
1140 return count;
1141 }
1142
wmi_create_device(struct device * wmi_bus_dev,struct wmi_block * wblock,struct acpi_device * device)1143 static int wmi_create_device(struct device *wmi_bus_dev,
1144 struct wmi_block *wblock,
1145 struct acpi_device *device)
1146 {
1147 struct acpi_device_info *info;
1148 char method[WMI_ACPI_METHOD_NAME_SIZE];
1149 int result;
1150 uint count;
1151
1152 if (wblock->gblock.flags & ACPI_WMI_EVENT) {
1153 wblock->dev.dev.type = &wmi_type_event;
1154 goto out_init;
1155 }
1156
1157 if (wblock->gblock.flags & ACPI_WMI_METHOD) {
1158 wblock->dev.dev.type = &wmi_type_method;
1159 mutex_init(&wblock->char_mutex);
1160 goto out_init;
1161 }
1162
1163 /*
1164 * Data Block Query Control Method (WQxx by convention) is
1165 * required per the WMI documentation. If it is not present,
1166 * we ignore this data block.
1167 */
1168 get_acpi_method_name(wblock, 'Q', method);
1169 result = get_subobj_info(device->handle, method, &info);
1170
1171 if (result) {
1172 dev_warn(wmi_bus_dev,
1173 "%s data block query control method not found\n",
1174 method);
1175 return result;
1176 }
1177
1178 wblock->dev.dev.type = &wmi_type_data;
1179
1180 /*
1181 * The Microsoft documentation specifically states:
1182 *
1183 * Data blocks registered with only a single instance
1184 * can ignore the parameter.
1185 *
1186 * ACPICA will get mad at us if we call the method with the wrong number
1187 * of arguments, so check what our method expects. (On some Dell
1188 * laptops, WQxx may not be a method at all.)
1189 */
1190 if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1191 set_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags);
1192
1193 kfree(info);
1194
1195 get_acpi_method_name(wblock, 'S', method);
1196 result = get_subobj_info(device->handle, method, NULL);
1197
1198 if (result == 0)
1199 wblock->dev.setable = true;
1200
1201 out_init:
1202 wblock->dev.dev.bus = &wmi_bus_type;
1203 wblock->dev.dev.parent = wmi_bus_dev;
1204
1205 count = guid_count(&wblock->gblock.guid);
1206 if (count)
1207 dev_set_name(&wblock->dev.dev, "%pUL-%d", &wblock->gblock.guid, count);
1208 else
1209 dev_set_name(&wblock->dev.dev, "%pUL", &wblock->gblock.guid);
1210
1211 device_initialize(&wblock->dev.dev);
1212
1213 return 0;
1214 }
1215
wmi_free_devices(struct acpi_device * device)1216 static void wmi_free_devices(struct acpi_device *device)
1217 {
1218 struct wmi_block *wblock, *next;
1219
1220 /* Delete devices for all the GUIDs */
1221 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1222 if (wblock->acpi_device == device) {
1223 list_del(&wblock->list);
1224 device_unregister(&wblock->dev.dev);
1225 }
1226 }
1227 }
1228
guid_already_parsed_for_legacy(struct acpi_device * device,const guid_t * guid)1229 static bool guid_already_parsed_for_legacy(struct acpi_device *device, const guid_t *guid)
1230 {
1231 struct wmi_block *wblock;
1232
1233 list_for_each_entry(wblock, &wmi_block_list, list) {
1234 /* skip warning and register if we know the driver will use struct wmi_driver */
1235 for (int i = 0; allow_duplicates[i] != NULL; i++) {
1236 if (guid_parse_and_compare(allow_duplicates[i], guid))
1237 return false;
1238 }
1239 if (guid_equal(&wblock->gblock.guid, guid)) {
1240 /*
1241 * Because we historically didn't track the relationship
1242 * between GUIDs and ACPI nodes, we don't know whether
1243 * we need to suppress GUIDs that are unique on a
1244 * given node but duplicated across nodes.
1245 */
1246 dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
1247 guid, dev_name(&wblock->acpi_device->dev));
1248 return true;
1249 }
1250 }
1251
1252 return false;
1253 }
1254
1255 /*
1256 * Parse the _WDG method for the GUID data blocks
1257 */
parse_wdg(struct device * wmi_bus_dev,struct acpi_device * device)1258 static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
1259 {
1260 struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1261 const struct guid_block *gblock;
1262 struct wmi_block *wblock, *next;
1263 union acpi_object *obj;
1264 acpi_status status;
1265 u32 i, total;
1266 int retval;
1267
1268 status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1269 if (ACPI_FAILURE(status))
1270 return -ENXIO;
1271
1272 obj = out.pointer;
1273 if (!obj)
1274 return -ENXIO;
1275
1276 if (obj->type != ACPI_TYPE_BUFFER) {
1277 kfree(obj);
1278 return -ENXIO;
1279 }
1280
1281 gblock = (const struct guid_block *)obj->buffer.pointer;
1282 total = obj->buffer.length / sizeof(struct guid_block);
1283
1284 for (i = 0; i < total; i++) {
1285 if (debug_dump_wdg)
1286 wmi_dump_wdg(&gblock[i]);
1287
1288 if (!gblock[i].instance_count) {
1289 dev_info(wmi_bus_dev, FW_INFO "%pUL has zero instances\n", &gblock[i].guid);
1290 continue;
1291 }
1292
1293 if (guid_already_parsed_for_legacy(device, &gblock[i].guid))
1294 continue;
1295
1296 wblock = kzalloc(sizeof(*wblock), GFP_KERNEL);
1297 if (!wblock) {
1298 dev_err(wmi_bus_dev, "Failed to allocate %pUL\n", &gblock[i].guid);
1299 continue;
1300 }
1301
1302 wblock->acpi_device = device;
1303 wblock->gblock = gblock[i];
1304
1305 retval = wmi_create_device(wmi_bus_dev, wblock, device);
1306 if (retval) {
1307 kfree(wblock);
1308 continue;
1309 }
1310
1311 list_add_tail(&wblock->list, &wmi_block_list);
1312
1313 if (debug_event) {
1314 wblock->handler = wmi_notify_debug;
1315 wmi_method_enable(wblock, true);
1316 }
1317 }
1318
1319 /*
1320 * Now that all of the devices are created, add them to the
1321 * device tree and probe subdrivers.
1322 */
1323 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1324 if (wblock->acpi_device != device)
1325 continue;
1326
1327 retval = device_add(&wblock->dev.dev);
1328 if (retval) {
1329 dev_err(wmi_bus_dev, "failed to register %pUL\n",
1330 &wblock->gblock.guid);
1331 if (debug_event)
1332 wmi_method_enable(wblock, false);
1333 list_del(&wblock->list);
1334 put_device(&wblock->dev.dev);
1335 }
1336 }
1337
1338 kfree(obj);
1339
1340 return 0;
1341 }
1342
1343 /*
1344 * WMI can have EmbeddedControl access regions. In which case, we just want to
1345 * hand these off to the EC driver.
1346 */
1347 static acpi_status
acpi_wmi_ec_space_handler(u32 function,acpi_physical_address address,u32 bits,u64 * value,void * handler_context,void * region_context)1348 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1349 u32 bits, u64 *value,
1350 void *handler_context, void *region_context)
1351 {
1352 int result = 0, i = 0;
1353 u8 temp = 0;
1354
1355 if ((address > 0xFF) || !value)
1356 return AE_BAD_PARAMETER;
1357
1358 if (function != ACPI_READ && function != ACPI_WRITE)
1359 return AE_BAD_PARAMETER;
1360
1361 if (bits != 8)
1362 return AE_BAD_PARAMETER;
1363
1364 if (function == ACPI_READ) {
1365 result = ec_read(address, &temp);
1366 (*value) |= ((u64)temp) << i;
1367 } else {
1368 temp = 0xff & ((*value) >> i);
1369 result = ec_write(address, temp);
1370 }
1371
1372 switch (result) {
1373 case -EINVAL:
1374 return AE_BAD_PARAMETER;
1375 case -ENODEV:
1376 return AE_NOT_FOUND;
1377 case -ETIME:
1378 return AE_TIME;
1379 default:
1380 return AE_OK;
1381 }
1382 }
1383
acpi_wmi_notify_handler(acpi_handle handle,u32 event,void * context)1384 static void acpi_wmi_notify_handler(acpi_handle handle, u32 event,
1385 void *context)
1386 {
1387 struct wmi_block *wblock = NULL, *iter;
1388
1389 list_for_each_entry(iter, &wmi_block_list, list) {
1390 struct guid_block *block = &iter->gblock;
1391
1392 if (iter->acpi_device->handle == handle &&
1393 (block->flags & ACPI_WMI_EVENT) &&
1394 (block->notify_id == event)) {
1395 wblock = iter;
1396 break;
1397 }
1398 }
1399
1400 if (!wblock)
1401 return;
1402
1403 /* If a driver is bound, then notify the driver. */
1404 if (test_bit(WMI_PROBED, &wblock->flags) && wblock->dev.dev.driver) {
1405 struct wmi_driver *driver = drv_to_wdrv(wblock->dev.dev.driver);
1406 struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL };
1407 acpi_status status;
1408
1409 if (!driver->no_notify_data) {
1410 status = get_event_data(wblock, &evdata);
1411 if (ACPI_FAILURE(status)) {
1412 dev_warn(&wblock->dev.dev, "failed to get event data\n");
1413 return;
1414 }
1415 }
1416
1417 if (driver->notify)
1418 driver->notify(&wblock->dev, evdata.pointer);
1419
1420 kfree(evdata.pointer);
1421 } else if (wblock->handler) {
1422 /* Legacy handler */
1423 wblock->handler(event, wblock->handler_data);
1424 }
1425
1426 if (debug_event)
1427 pr_info("DEBUG: GUID %pUL event 0x%02X\n", &wblock->gblock.guid, event);
1428
1429 acpi_bus_generate_netlink_event(
1430 wblock->acpi_device->pnp.device_class,
1431 dev_name(&wblock->dev.dev),
1432 event, 0);
1433 }
1434
acpi_wmi_remove(struct platform_device * device)1435 static void acpi_wmi_remove(struct platform_device *device)
1436 {
1437 struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev);
1438
1439 acpi_remove_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY,
1440 acpi_wmi_notify_handler);
1441 acpi_remove_address_space_handler(acpi_device->handle,
1442 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
1443 wmi_free_devices(acpi_device);
1444 device_unregister(dev_get_drvdata(&device->dev));
1445 }
1446
acpi_wmi_probe(struct platform_device * device)1447 static int acpi_wmi_probe(struct platform_device *device)
1448 {
1449 struct acpi_device *acpi_device;
1450 struct device *wmi_bus_dev;
1451 acpi_status status;
1452 int error;
1453
1454 acpi_device = ACPI_COMPANION(&device->dev);
1455 if (!acpi_device) {
1456 dev_err(&device->dev, "ACPI companion is missing\n");
1457 return -ENODEV;
1458 }
1459
1460 status = acpi_install_address_space_handler(acpi_device->handle,
1461 ACPI_ADR_SPACE_EC,
1462 &acpi_wmi_ec_space_handler,
1463 NULL, NULL);
1464 if (ACPI_FAILURE(status)) {
1465 dev_err(&device->dev, "Error installing EC region handler\n");
1466 return -ENODEV;
1467 }
1468
1469 status = acpi_install_notify_handler(acpi_device->handle,
1470 ACPI_ALL_NOTIFY,
1471 acpi_wmi_notify_handler,
1472 NULL);
1473 if (ACPI_FAILURE(status)) {
1474 dev_err(&device->dev, "Error installing notify handler\n");
1475 error = -ENODEV;
1476 goto err_remove_ec_handler;
1477 }
1478
1479 wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0),
1480 NULL, "wmi_bus-%s", dev_name(&device->dev));
1481 if (IS_ERR(wmi_bus_dev)) {
1482 error = PTR_ERR(wmi_bus_dev);
1483 goto err_remove_notify_handler;
1484 }
1485 dev_set_drvdata(&device->dev, wmi_bus_dev);
1486
1487 error = parse_wdg(wmi_bus_dev, acpi_device);
1488 if (error) {
1489 pr_err("Failed to parse WDG method\n");
1490 goto err_remove_busdev;
1491 }
1492
1493 return 0;
1494
1495 err_remove_busdev:
1496 device_unregister(wmi_bus_dev);
1497
1498 err_remove_notify_handler:
1499 acpi_remove_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY,
1500 acpi_wmi_notify_handler);
1501
1502 err_remove_ec_handler:
1503 acpi_remove_address_space_handler(acpi_device->handle,
1504 ACPI_ADR_SPACE_EC,
1505 &acpi_wmi_ec_space_handler);
1506
1507 return error;
1508 }
1509
__wmi_driver_register(struct wmi_driver * driver,struct module * owner)1510 int __must_check __wmi_driver_register(struct wmi_driver *driver,
1511 struct module *owner)
1512 {
1513 driver->driver.owner = owner;
1514 driver->driver.bus = &wmi_bus_type;
1515
1516 return driver_register(&driver->driver);
1517 }
1518 EXPORT_SYMBOL(__wmi_driver_register);
1519
1520 /**
1521 * wmi_driver_unregister() - Unregister a WMI driver
1522 * @driver: WMI driver to unregister
1523 *
1524 * Unregisters a WMI driver from the WMI bus.
1525 */
wmi_driver_unregister(struct wmi_driver * driver)1526 void wmi_driver_unregister(struct wmi_driver *driver)
1527 {
1528 driver_unregister(&driver->driver);
1529 }
1530 EXPORT_SYMBOL(wmi_driver_unregister);
1531
1532 static struct platform_driver acpi_wmi_driver = {
1533 .driver = {
1534 .name = "acpi-wmi",
1535 .acpi_match_table = wmi_device_ids,
1536 },
1537 .probe = acpi_wmi_probe,
1538 .remove_new = acpi_wmi_remove,
1539 };
1540
acpi_wmi_init(void)1541 static int __init acpi_wmi_init(void)
1542 {
1543 int error;
1544
1545 if (acpi_disabled)
1546 return -ENODEV;
1547
1548 error = class_register(&wmi_bus_class);
1549 if (error)
1550 return error;
1551
1552 error = bus_register(&wmi_bus_type);
1553 if (error)
1554 goto err_unreg_class;
1555
1556 error = platform_driver_register(&acpi_wmi_driver);
1557 if (error) {
1558 pr_err("Error loading mapper\n");
1559 goto err_unreg_bus;
1560 }
1561
1562 return 0;
1563
1564 err_unreg_bus:
1565 bus_unregister(&wmi_bus_type);
1566
1567 err_unreg_class:
1568 class_unregister(&wmi_bus_class);
1569
1570 return error;
1571 }
1572
acpi_wmi_exit(void)1573 static void __exit acpi_wmi_exit(void)
1574 {
1575 platform_driver_unregister(&acpi_wmi_driver);
1576 bus_unregister(&wmi_bus_type);
1577 class_unregister(&wmi_bus_class);
1578 }
1579
1580 subsys_initcall_sync(acpi_wmi_init);
1581 module_exit(acpi_wmi_exit);
1582