Version:  2.0.40 2.2.26 2.4.37 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16

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

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