Version:  2.0.40 2.2.26 2.4.37 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 3.18 3.19 4.0 4.1

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

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