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