Version:  2.0.40 2.2.26 2.4.37 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 3.17

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         snprintf(method, 5, "WE%02X", block->notify_id);
260         status = acpi_execute_simple_method(handle, method, enable);
261 
262         if (status != AE_OK && status != AE_NOT_FOUND)
263                 return status;
264         else
265                 return AE_OK;
266 }
267 
268 /*
269  * Exported WMI functions
270  */
271 /**
272  * wmi_evaluate_method - Evaluate a WMI method
273  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
274  * @instance: Instance index
275  * @method_id: Method ID to call
276  * &in: Buffer containing input for the method call
277  * &out: Empty buffer to return the method results
278  *
279  * Call an ACPI-WMI method
280  */
281 acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
282 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
283 {
284         struct guid_block *block = NULL;
285         struct wmi_block *wblock = NULL;
286         acpi_handle handle;
287         acpi_status status;
288         struct acpi_object_list input;
289         union acpi_object params[3];
290         char method[5] = "WM";
291 
292         if (!find_guid(guid_string, &wblock))
293                 return AE_ERROR;
294 
295         block = &wblock->gblock;
296         handle = wblock->handle;
297 
298         if (!(block->flags & ACPI_WMI_METHOD))
299                 return AE_BAD_DATA;
300 
301         if (block->instance_count < instance)
302                 return AE_BAD_PARAMETER;
303 
304         input.count = 2;
305         input.pointer = params;
306         params[0].type = ACPI_TYPE_INTEGER;
307         params[0].integer.value = instance;
308         params[1].type = ACPI_TYPE_INTEGER;
309         params[1].integer.value = method_id;
310 
311         if (in) {
312                 input.count = 3;
313 
314                 if (block->flags & ACPI_WMI_STRING) {
315                         params[2].type = ACPI_TYPE_STRING;
316                 } else {
317                         params[2].type = ACPI_TYPE_BUFFER;
318                 }
319                 params[2].buffer.length = in->length;
320                 params[2].buffer.pointer = in->pointer;
321         }
322 
323         strncat(method, block->object_id, 2);
324 
325         status = acpi_evaluate_object(handle, method, &input, out);
326 
327         return status;
328 }
329 EXPORT_SYMBOL_GPL(wmi_evaluate_method);
330 
331 /**
332  * wmi_query_block - Return contents of a WMI block
333  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
334  * @instance: Instance index
335  * &out: Empty buffer to return the contents of the data block to
336  *
337  * Return the contents of an ACPI-WMI data block to a buffer
338  */
339 acpi_status wmi_query_block(const char *guid_string, u8 instance,
340 struct acpi_buffer *out)
341 {
342         struct guid_block *block = NULL;
343         struct wmi_block *wblock = NULL;
344         acpi_handle handle;
345         acpi_status status, wc_status = AE_ERROR;
346         struct acpi_object_list input;
347         union acpi_object wq_params[1];
348         char method[5];
349         char wc_method[5] = "WC";
350 
351         if (!guid_string || !out)
352                 return AE_BAD_PARAMETER;
353 
354         if (!find_guid(guid_string, &wblock))
355                 return AE_ERROR;
356 
357         block = &wblock->gblock;
358         handle = wblock->handle;
359 
360         if (block->instance_count < instance)
361                 return AE_BAD_PARAMETER;
362 
363         /* Check GUID is a data block */
364         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
365                 return AE_ERROR;
366 
367         input.count = 1;
368         input.pointer = wq_params;
369         wq_params[0].type = ACPI_TYPE_INTEGER;
370         wq_params[0].integer.value = instance;
371 
372         /*
373          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
374          * enable collection.
375          */
376         if (block->flags & ACPI_WMI_EXPENSIVE) {
377                 strncat(wc_method, block->object_id, 2);
378 
379                 /*
380                  * Some GUIDs break the specification by declaring themselves
381                  * expensive, but have no corresponding WCxx method. So we
382                  * should not fail if this happens.
383                  */
384                 if (acpi_has_method(handle, wc_method))
385                         wc_status = acpi_execute_simple_method(handle,
386                                                                 wc_method, 1);
387         }
388 
389         strcpy(method, "WQ");
390         strncat(method, block->object_id, 2);
391 
392         status = acpi_evaluate_object(handle, method, &input, out);
393 
394         /*
395          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
396          * the WQxx method failed - we should disable collection anyway.
397          */
398         if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
399                 status = acpi_execute_simple_method(handle, wc_method, 0);
400         }
401 
402         return status;
403 }
404 EXPORT_SYMBOL_GPL(wmi_query_block);
405 
406 /**
407  * wmi_set_block - Write to a WMI block
408  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
409  * @instance: Instance index
410  * &in: Buffer containing new values for the data block
411  *
412  * Write the contents of the input buffer to an ACPI-WMI data block
413  */
414 acpi_status wmi_set_block(const char *guid_string, u8 instance,
415 const struct acpi_buffer *in)
416 {
417         struct guid_block *block = NULL;
418         struct wmi_block *wblock = NULL;
419         acpi_handle handle;
420         struct acpi_object_list input;
421         union acpi_object params[2];
422         char method[5] = "WS";
423 
424         if (!guid_string || !in)
425                 return AE_BAD_DATA;
426 
427         if (!find_guid(guid_string, &wblock))
428                 return AE_ERROR;
429 
430         block = &wblock->gblock;
431         handle = wblock->handle;
432 
433         if (block->instance_count < instance)
434                 return AE_BAD_PARAMETER;
435 
436         /* Check GUID is a data block */
437         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
438                 return AE_ERROR;
439 
440         input.count = 2;
441         input.pointer = params;
442         params[0].type = ACPI_TYPE_INTEGER;
443         params[0].integer.value = instance;
444 
445         if (block->flags & ACPI_WMI_STRING) {
446                 params[1].type = ACPI_TYPE_STRING;
447         } else {
448                 params[1].type = ACPI_TYPE_BUFFER;
449         }
450         params[1].buffer.length = in->length;
451         params[1].buffer.pointer = in->pointer;
452 
453         strncat(method, block->object_id, 2);
454 
455         return acpi_evaluate_object(handle, method, &input, NULL);
456 }
457 EXPORT_SYMBOL_GPL(wmi_set_block);
458 
459 static void wmi_dump_wdg(const struct guid_block *g)
460 {
461         char guid_string[37];
462 
463         wmi_gtoa(g->guid, guid_string);
464 
465         pr_info("%s:\n", guid_string);
466         pr_info("\tobject_id: %c%c\n", g->object_id[0], g->object_id[1]);
467         pr_info("\tnotify_id: %02X\n", g->notify_id);
468         pr_info("\treserved: %02X\n", g->reserved);
469         pr_info("\tinstance_count: %d\n", g->instance_count);
470         pr_info("\tflags: %#x", g->flags);
471         if (g->flags) {
472                 if (g->flags & ACPI_WMI_EXPENSIVE)
473                         pr_cont(" ACPI_WMI_EXPENSIVE");
474                 if (g->flags & ACPI_WMI_METHOD)
475                         pr_cont(" ACPI_WMI_METHOD");
476                 if (g->flags & ACPI_WMI_STRING)
477                         pr_cont(" ACPI_WMI_STRING");
478                 if (g->flags & ACPI_WMI_EVENT)
479                         pr_cont(" ACPI_WMI_EVENT");
480         }
481         pr_cont("\n");
482 
483 }
484 
485 static void wmi_notify_debug(u32 value, void *context)
486 {
487         struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
488         union acpi_object *obj;
489         acpi_status status;
490 
491         status = wmi_get_event_data(value, &response);
492         if (status != AE_OK) {
493                 pr_info("bad event status 0x%x\n", status);
494                 return;
495         }
496 
497         obj = (union acpi_object *)response.pointer;
498 
499         if (!obj)
500                 return;
501 
502         pr_info("DEBUG Event ");
503         switch(obj->type) {
504         case ACPI_TYPE_BUFFER:
505                 pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
506                 break;
507         case ACPI_TYPE_STRING:
508                 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
509                 break;
510         case ACPI_TYPE_INTEGER:
511                 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
512                 break;
513         case ACPI_TYPE_PACKAGE:
514                 pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
515                 break;
516         default:
517                 pr_cont("object type 0x%X\n", obj->type);
518         }
519         kfree(obj);
520 }
521 
522 /**
523  * wmi_install_notify_handler - Register handler for WMI events
524  * @handler: Function to handle notifications
525  * @data: Data to be returned to handler when event is fired
526  *
527  * Register a handler for events sent to the ACPI-WMI mapper device.
528  */
529 acpi_status wmi_install_notify_handler(const char *guid,
530 wmi_notify_handler handler, void *data)
531 {
532         struct wmi_block *block;
533         acpi_status status = AE_NOT_EXIST;
534         char tmp[16], guid_input[16];
535         struct list_head *p;
536 
537         if (!guid || !handler)
538                 return AE_BAD_PARAMETER;
539 
540         wmi_parse_guid(guid, tmp);
541         wmi_swap_bytes(tmp, guid_input);
542 
543         list_for_each(p, &wmi_block_list) {
544                 acpi_status wmi_status;
545                 block = list_entry(p, struct wmi_block, list);
546 
547                 if (memcmp(block->gblock.guid, guid_input, 16) == 0) {
548                         if (block->handler &&
549                             block->handler != wmi_notify_debug)
550                                 return AE_ALREADY_ACQUIRED;
551 
552                         block->handler = handler;
553                         block->handler_data = data;
554 
555                         wmi_status = wmi_method_enable(block, 1);
556                         if ((wmi_status != AE_OK) ||
557                             ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
558                                 status = wmi_status;
559                 }
560         }
561 
562         return status;
563 }
564 EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
565 
566 /**
567  * wmi_uninstall_notify_handler - Unregister handler for WMI events
568  *
569  * Unregister handler for events sent to the ACPI-WMI mapper device.
570  */
571 acpi_status wmi_remove_notify_handler(const char *guid)
572 {
573         struct wmi_block *block;
574         acpi_status status = AE_NOT_EXIST;
575         char tmp[16], guid_input[16];
576         struct list_head *p;
577 
578         if (!guid)
579                 return AE_BAD_PARAMETER;
580 
581         wmi_parse_guid(guid, tmp);
582         wmi_swap_bytes(tmp, guid_input);
583 
584         list_for_each(p, &wmi_block_list) {
585                 acpi_status wmi_status;
586                 block = list_entry(p, struct wmi_block, list);
587 
588                 if (memcmp(block->gblock.guid, guid_input, 16) == 0) {
589                         if (!block->handler ||
590                             block->handler == wmi_notify_debug)
591                                 return AE_NULL_ENTRY;
592 
593                         if (debug_event) {
594                                 block->handler = wmi_notify_debug;
595                                 status = AE_OK;
596                         } else {
597                                 wmi_status = wmi_method_enable(block, 0);
598                                 block->handler = NULL;
599                                 block->handler_data = NULL;
600                                 if ((wmi_status != AE_OK) ||
601                                     ((wmi_status == AE_OK) &&
602                                      (status == AE_NOT_EXIST)))
603                                         status = wmi_status;
604                         }
605                 }
606         }
607 
608         return status;
609 }
610 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
611 
612 /**
613  * wmi_get_event_data - Get WMI data associated with an event
614  *
615  * @event: Event to find
616  * @out: Buffer to hold event data. out->pointer should be freed with kfree()
617  *
618  * Returns extra data associated with an event in WMI.
619  */
620 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
621 {
622         struct acpi_object_list input;
623         union acpi_object params[1];
624         struct guid_block *gblock;
625         struct wmi_block *wblock;
626         struct list_head *p;
627 
628         input.count = 1;
629         input.pointer = params;
630         params[0].type = ACPI_TYPE_INTEGER;
631         params[0].integer.value = event;
632 
633         list_for_each(p, &wmi_block_list) {
634                 wblock = list_entry(p, struct wmi_block, list);
635                 gblock = &wblock->gblock;
636 
637                 if ((gblock->flags & ACPI_WMI_EVENT) &&
638                         (gblock->notify_id == event))
639                         return acpi_evaluate_object(wblock->handle, "_WED",
640                                 &input, out);
641         }
642 
643         return AE_NOT_FOUND;
644 }
645 EXPORT_SYMBOL_GPL(wmi_get_event_data);
646 
647 /**
648  * wmi_has_guid - Check if a GUID is available
649  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
650  *
651  * Check if a given GUID is defined by _WDG
652  */
653 bool wmi_has_guid(const char *guid_string)
654 {
655         return find_guid(guid_string, NULL);
656 }
657 EXPORT_SYMBOL_GPL(wmi_has_guid);
658 
659 /*
660  * sysfs interface
661  */
662 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
663                              char *buf)
664 {
665         char guid_string[37];
666         struct wmi_block *wblock;
667 
668         wblock = dev_get_drvdata(dev);
669         if (!wblock) {
670                 strcat(buf, "\n");
671                 return strlen(buf);
672         }
673 
674         wmi_gtoa(wblock->gblock.guid, guid_string);
675 
676         return sprintf(buf, "wmi:%s\n", guid_string);
677 }
678 static DEVICE_ATTR_RO(modalias);
679 
680 static struct attribute *wmi_attrs[] = {
681         &dev_attr_modalias.attr,
682         NULL,
683 };
684 ATTRIBUTE_GROUPS(wmi);
685 
686 static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
687 {
688         char guid_string[37];
689 
690         struct wmi_block *wblock;
691 
692         if (add_uevent_var(env, "MODALIAS="))
693                 return -ENOMEM;
694 
695         wblock = dev_get_drvdata(dev);
696         if (!wblock)
697                 return -ENOMEM;
698 
699         wmi_gtoa(wblock->gblock.guid, guid_string);
700 
701         strcpy(&env->buf[env->buflen - 1], "wmi:");
702         memcpy(&env->buf[env->buflen - 1 + 4], guid_string, 36);
703         env->buflen += 40;
704 
705         return 0;
706 }
707 
708 static void wmi_dev_free(struct device *dev)
709 {
710         struct wmi_block *wmi_block = container_of(dev, struct wmi_block, dev);
711 
712         kfree(wmi_block);
713 }
714 
715 static struct class wmi_class = {
716         .name = "wmi",
717         .dev_release = wmi_dev_free,
718         .dev_uevent = wmi_dev_uevent,
719         .dev_groups = wmi_groups,
720 };
721 
722 static int wmi_create_device(const struct guid_block *gblock,
723                              struct wmi_block *wblock, acpi_handle handle)
724 {
725         char guid_string[37];
726 
727         wblock->dev.class = &wmi_class;
728 
729         wmi_gtoa(gblock->guid, guid_string);
730         dev_set_name(&wblock->dev, "%s", guid_string);
731 
732         dev_set_drvdata(&wblock->dev, wblock);
733 
734         return device_register(&wblock->dev);
735 }
736 
737 static void wmi_free_devices(void)
738 {
739         struct wmi_block *wblock, *next;
740 
741         /* Delete devices for all the GUIDs */
742         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
743                 list_del(&wblock->list);
744                 if (wblock->dev.class)
745                         device_unregister(&wblock->dev);
746                 else
747                         kfree(wblock);
748         }
749 }
750 
751 static bool guid_already_parsed(const char *guid_string)
752 {
753         struct wmi_block *wblock;
754 
755         list_for_each_entry(wblock, &wmi_block_list, list)
756                 if (memcmp(wblock->gblock.guid, guid_string, 16) == 0)
757                         return true;
758 
759         return false;
760 }
761 
762 /*
763  * Parse the _WDG method for the GUID data blocks
764  */
765 static int parse_wdg(acpi_handle handle)
766 {
767         struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
768         union acpi_object *obj;
769         const struct guid_block *gblock;
770         struct wmi_block *wblock;
771         acpi_status status;
772         int retval;
773         u32 i, total;
774 
775         status = acpi_evaluate_object(handle, "_WDG", NULL, &out);
776         if (ACPI_FAILURE(status))
777                 return -ENXIO;
778 
779         obj = (union acpi_object *) out.pointer;
780         if (!obj)
781                 return -ENXIO;
782 
783         if (obj->type != ACPI_TYPE_BUFFER) {
784                 retval = -ENXIO;
785                 goto out_free_pointer;
786         }
787 
788         gblock = (const struct guid_block *)obj->buffer.pointer;
789         total = obj->buffer.length / sizeof(struct guid_block);
790 
791         for (i = 0; i < total; i++) {
792                 if (debug_dump_wdg)
793                         wmi_dump_wdg(&gblock[i]);
794 
795                 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
796                 if (!wblock)
797                         return -ENOMEM;
798 
799                 wblock->handle = handle;
800                 wblock->gblock = gblock[i];
801 
802                 /*
803                   Some WMI devices, like those for nVidia hooks, have a
804                   duplicate GUID. It's not clear what we should do in this
805                   case yet, so for now, we'll just ignore the duplicate
806                   for device creation.
807                 */
808                 if (!guid_already_parsed(gblock[i].guid)) {
809                         retval = wmi_create_device(&gblock[i], wblock, handle);
810                         if (retval) {
811                                 wmi_free_devices();
812                                 goto out_free_pointer;
813                         }
814                 }
815 
816                 list_add_tail(&wblock->list, &wmi_block_list);
817 
818                 if (debug_event) {
819                         wblock->handler = wmi_notify_debug;
820                         wmi_method_enable(wblock, 1);
821                 }
822         }
823 
824         retval = 0;
825 
826 out_free_pointer:
827         kfree(out.pointer);
828 
829         return retval;
830 }
831 
832 /*
833  * WMI can have EmbeddedControl access regions. In which case, we just want to
834  * hand these off to the EC driver.
835  */
836 static acpi_status
837 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
838                       u32 bits, u64 *value,
839                       void *handler_context, void *region_context)
840 {
841         int result = 0, i = 0;
842         u8 temp = 0;
843 
844         if ((address > 0xFF) || !value)
845                 return AE_BAD_PARAMETER;
846 
847         if (function != ACPI_READ && function != ACPI_WRITE)
848                 return AE_BAD_PARAMETER;
849 
850         if (bits != 8)
851                 return AE_BAD_PARAMETER;
852 
853         if (function == ACPI_READ) {
854                 result = ec_read(address, &temp);
855                 (*value) |= ((u64)temp) << i;
856         } else {
857                 temp = 0xff & ((*value) >> i);
858                 result = ec_write(address, temp);
859         }
860 
861         switch (result) {
862         case -EINVAL:
863                 return AE_BAD_PARAMETER;
864                 break;
865         case -ENODEV:
866                 return AE_NOT_FOUND;
867                 break;
868         case -ETIME:
869                 return AE_TIME;
870                 break;
871         default:
872                 return AE_OK;
873         }
874 }
875 
876 static void acpi_wmi_notify(struct acpi_device *device, u32 event)
877 {
878         struct guid_block *block;
879         struct wmi_block *wblock;
880         struct list_head *p;
881         char guid_string[37];
882 
883         list_for_each(p, &wmi_block_list) {
884                 wblock = list_entry(p, struct wmi_block, list);
885                 block = &wblock->gblock;
886 
887                 if ((block->flags & ACPI_WMI_EVENT) &&
888                         (block->notify_id == event)) {
889                         if (wblock->handler)
890                                 wblock->handler(event, wblock->handler_data);
891                         if (debug_event) {
892                                 wmi_gtoa(wblock->gblock.guid, guid_string);
893                                 pr_info("DEBUG Event GUID: %s\n", guid_string);
894                         }
895 
896                         acpi_bus_generate_netlink_event(
897                                 device->pnp.device_class, dev_name(&device->dev),
898                                 event, 0);
899                         break;
900                 }
901         }
902 }
903 
904 static int acpi_wmi_remove(struct acpi_device *device)
905 {
906         acpi_remove_address_space_handler(device->handle,
907                                 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
908         wmi_free_devices();
909 
910         return 0;
911 }
912 
913 static int acpi_wmi_add(struct acpi_device *device)
914 {
915         acpi_status status;
916         int error;
917 
918         status = acpi_install_address_space_handler(device->handle,
919                                                     ACPI_ADR_SPACE_EC,
920                                                     &acpi_wmi_ec_space_handler,
921                                                     NULL, NULL);
922         if (ACPI_FAILURE(status)) {
923                 pr_err("Error installing EC region handler\n");
924                 return -ENODEV;
925         }
926 
927         error = parse_wdg(device->handle);
928         if (error) {
929                 acpi_remove_address_space_handler(device->handle,
930                                                   ACPI_ADR_SPACE_EC,
931                                                   &acpi_wmi_ec_space_handler);
932                 pr_err("Failed to parse WDG method\n");
933                 return error;
934         }
935 
936         return 0;
937 }
938 
939 static int __init acpi_wmi_init(void)
940 {
941         int error;
942 
943         if (acpi_disabled)
944                 return -ENODEV;
945 
946         error = class_register(&wmi_class);
947         if (error)
948                 return error;
949 
950         error = acpi_bus_register_driver(&acpi_wmi_driver);
951         if (error) {
952                 pr_err("Error loading mapper\n");
953                 class_unregister(&wmi_class);
954                 return error;
955         }
956 
957         pr_info("Mapper loaded\n");
958         return 0;
959 }
960 
961 static void __exit acpi_wmi_exit(void)
962 {
963         acpi_bus_unregister_driver(&acpi_wmi_driver);
964         class_unregister(&wmi_class);
965 
966         pr_info("Mapper unloaded\n");
967 }
968 
969 subsys_initcall(acpi_wmi_init);
970 module_exit(acpi_wmi_exit);
971 

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