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