Version:  2.0.40 2.2.26 2.4.37 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5

Linux/drivers/platform/x86/wmi.c

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

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