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 #include <linux/kernel.h>
  31 #include <linux/init.h>
  32 #include <linux/types.h>
  33 #include <linux/list.h>
  34 #include <linux/acpi.h>
  35 #include <acpi/acpi_bus.h>
  36 #include <acpi/acpi_drivers.h>
  37
  38 ACPI_MODULE_NAME("wmi");
  39 MODULE_AUTHOR("Carlos Corbacho");
  40 MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
  41 MODULE_LICENSE("GPL");
  42
  43 #define ACPI_WMI_CLASS "wmi"
  44
  45 #define PREFIX "ACPI: WMI: "
  46
  47 static DEFINE_MUTEX(wmi_data_lock);
  48
  49 struct guid_block {
  50         char guid[16];
  51         union {
  52                 char object_id[2];
  53                 struct {
  54                         unsigned char notify_id;
  55                         unsigned char reserved;
  56                 };
  57         };
  58         u8 instance_count;
  59         u8 flags;
  60 };
  61
  62 struct wmi_block {
  63         struct list_head list;
  64         struct guid_block gblock;
  65         acpi_handle handle;
  66         wmi_notify_handler handler;
  67         void *handler_data;
  68 };
  69
  70 static struct wmi_block wmi_blocks;
  71
  72 /*
  73  * If the GUID data block is marked as expensive, we must enable and
  74  * explicitily disable data collection.
  75  */
  76 #define ACPI_WMI_EXPENSIVE   0x1
  77 #define ACPI_WMI_METHOD      0x2        /* GUID is a method */
  78 #define ACPI_WMI_STRING      0x4        /* GUID takes & returns a string */
  79 #define ACPI_WMI_EVENT       0x8        /* GUID is an event */
  80
  81 static int acpi_wmi_remove(struct acpi_device *device, int type);
  82 static int acpi_wmi_add(struct acpi_device *device);
  83 static void acpi_wmi_notify(struct acpi_device *device, u32 event);
  84
  85 static const struct acpi_device_id wmi_device_ids[] = {
  86         {"PNP0C14", 0},
  87         {"pnp0c14", 0},
  88         {"", 0},
  89 };
  90 MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
  91
  92 static struct acpi_driver acpi_wmi_driver = {
  93         .name = "wmi",
  94         .class = ACPI_WMI_CLASS,
  95         .ids = wmi_device_ids,
  96         .ops = {
  97                 .add = acpi_wmi_add,
  98                 .remove = acpi_wmi_remove,
  99                 .notify = acpi_wmi_notify,
 100                 },
 101 };
 102
 103 /*
 104  * GUID parsing functions
 105  */
 106
 107 /**
 108  * wmi_parse_hexbyte - Convert a ASCII hex number to a byte
 109  * @src:  Pointer to at least 2 characters to convert.
 110  *
 111  * Convert a two character ASCII hex string to a number.
 112  *
 113  * Return:  0-255  Success, the byte was parsed correctly
 114  *          -1     Error, an invalid character was supplied
 115  */
 116 static int wmi_parse_hexbyte(const u8 *src)
 117 {
 118         unsigned int x; /* For correct wrapping */
 119         int h;
 120
 121         /* high part */
 122         x = src[0];
 123         if (x - '0' <= '9' - '0') {
 124                 h = x - '0';
 125         } else if (x - 'a' <= 'f' - 'a') {
 126                 h = x - 'a' + 10;
 127         } else if (x - 'A' <= 'F' - 'A') {
 128                 h = x - 'A' + 10;
 129         } else {
 130                 return -1;
 131         }
 132         h <<= 4;
 133
 134         /* low part */
 135         x = src[1];
 136         if (x - '0' <= '9' - '0')
 137                 return h | (x - '0');
 138         if (x - 'a' <= 'f' - 'a')
 139                 return h | (x - 'a' + 10);
 140         if (x - 'A' <= 'F' - 'A')
 141                 return h | (x - 'A' + 10);
 142         return -1;
 143 }
 144
 145 /**
 146  * wmi_swap_bytes - Rearrange GUID bytes to match GUID binary
 147  * @src:   Memory block holding binary GUID (16 bytes)
 148  * @dest:  Memory block to hold byte swapped binary GUID (16 bytes)
 149  *
 150  * Byte swap a binary GUID to match it's real GUID value
 151  */
 152 static void wmi_swap_bytes(u8 *src, u8 *dest)
 153 {
 154         int i;
 155
 156         for (i = 0; i <= 3; i++)
 157                 memcpy(dest + i, src + (3 - i), 1);
 158
 159         for (i = 0; i <= 1; i++)
 160                 memcpy(dest + 4 + i, src + (5 - i), 1);
 161
 162         for (i = 0; i <= 1; i++)
 163                 memcpy(dest + 6 + i, src + (7 - i), 1);
 164
 165         memcpy(dest + 8, src + 8, 8);
 166 }
 167
 168 /**
 169  * wmi_parse_guid - Convert GUID from ASCII to binary
 170  * @src:   36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 171  * @dest:  Memory block to hold binary GUID (16 bytes)
 172  *
 173  * N.B. The GUID need not be NULL terminated.
 174  *
 175  * Return:  'true'   @dest contains binary GUID
 176  *          'false'  @dest contents are undefined
 177  */
 178 static bool wmi_parse_guid(const u8 *src, u8 *dest)
 179 {
 180         static const int size[] = { 4, 2, 2, 2, 6 };
 181         int i, j, v;
 182
 183         if (src[8]  != '-' || src[13] != '-' ||
 184                 src[18] != '-' || src[23] != '-')
 185                 return false;
 186
 187         for (j = 0; j < 5; j++, src++) {
 188                 for (i = 0; i < size[j]; i++, src += 2, *dest++ = v) {
 189                         v = wmi_parse_hexbyte(src);
 190                         if (v < 0)
 191                                 return false;
 192                 }
 193         }
 194
 195         return true;
 196 }
 197
 198 static bool find_guid(const char *guid_string, struct wmi_block **out)
 199 {
 200         char tmp[16], guid_input[16];
 201         struct wmi_block *wblock;
 202         struct guid_block *block;
 203         struct list_head *p;
 204
 205         wmi_parse_guid(guid_string, tmp);
 206         wmi_swap_bytes(tmp, guid_input);
 207
 208         list_for_each(p, &wmi_blocks.list) {
 209                 wblock = list_entry(p, struct wmi_block, list);
 210                 block = &wblock->gblock;
 211
 212                 if (memcmp(block->guid, guid_input, 16) == 0) {
 213                         if (out)
 214                                 *out = wblock;
 215                         return 1;
 216                 }
 217         }
 218         return 0;
 219 }
 220
 221 static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable)
 222 {
 223         struct guid_block *block = NULL;
 224         char method[5];
 225         struct acpi_object_list input;
 226         union acpi_object params[1];
 227         acpi_status status;
 228         acpi_handle handle;
 229
 230         block = &wblock->gblock;
 231         handle = wblock->handle;
 232
 233         if (!block)
 234                 return AE_NOT_EXIST;
 235
 236         input.count = 1;
 237         input.pointer = params;
 238         params[0].type = ACPI_TYPE_INTEGER;
 239         params[0].integer.value = enable;
 240
 241         snprintf(method, 5, "WE%02X", block->notify_id);
 242         status = acpi_evaluate_object(handle, method, &input, NULL);
 243
 244         if (status != AE_OK && status != AE_NOT_FOUND)
 245                 return status;
 246         else
 247                 return AE_OK;
 248 }
 249
 250 /*
 251  * Exported WMI functions
 252  */
 253 /**
 254  * wmi_evaluate_method - Evaluate a WMI method
 255  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 256  * @instance: Instance index
 257  * @method_id: Method ID to call
 258  * &in: Buffer containing input for the method call
 259  * &out: Empty buffer to return the method results
 260  *
 261  * Call an ACPI-WMI method
 262  */
 263 acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
 264 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
 265 {
 266         struct guid_block *block = NULL;
 267         struct wmi_block *wblock = NULL;
 268         acpi_handle handle;
 269         acpi_status status;
 270         struct acpi_object_list input;
 271         union acpi_object params[3];
 272         char method[5] = "WM";
 273
 274         if (!find_guid(guid_string, &wblock))
 275                 return AE_ERROR;
 276
 277         block = &wblock->gblock;
 278         handle = wblock->handle;
 279
 280         if (!(block->flags & ACPI_WMI_METHOD))
 281                 return AE_BAD_DATA;
 282
 283         if (block->instance_count < instance)
 284                 return AE_BAD_PARAMETER;
 285
 286         input.count = 2;
 287         input.pointer = params;
 288         params[0].type = ACPI_TYPE_INTEGER;
 289         params[0].integer.value = instance;
 290         params[1].type = ACPI_TYPE_INTEGER;
 291         params[1].integer.value = method_id;
 292
 293         if (in) {
 294                 input.count = 3;
 295
 296                 if (block->flags & ACPI_WMI_STRING) {
 297                         params[2].type = ACPI_TYPE_STRING;
 298                 } else {
 299                         params[2].type = ACPI_TYPE_BUFFER;
 300                 }
 301                 params[2].buffer.length = in->length;
 302                 params[2].buffer.pointer = in->pointer;
 303         }
 304
 305         strncat(method, block->object_id, 2);
 306
 307         status = acpi_evaluate_object(handle, method, &input, out);
 308
 309         return status;
 310 }
 311 EXPORT_SYMBOL_GPL(wmi_evaluate_method);
 312
 313 /**
 314  * wmi_query_block - Return contents of a WMI block
 315  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 316  * @instance: Instance index
 317  * &out: Empty buffer to return the contents of the data block to
 318  *
 319  * Return the contents of an ACPI-WMI data block to a buffer
 320  */
 321 acpi_status wmi_query_block(const char *guid_string, u8 instance,
 322 struct acpi_buffer *out)
 323 {
 324         struct guid_block *block = NULL;
 325         struct wmi_block *wblock = NULL;
 326         acpi_handle handle, wc_handle;
 327         acpi_status status, wc_status = AE_ERROR;
 328         struct acpi_object_list input, wc_input;
 329         union acpi_object wc_params[1], wq_params[1];
 330         char method[5];
 331         char wc_method[5] = "WC";
 332
 333         if (!guid_string || !out)
 334                 return AE_BAD_PARAMETER;
 335
 336         if (!find_guid(guid_string, &wblock))
 337                 return AE_ERROR;
 338
 339         block = &wblock->gblock;
 340         handle = wblock->handle;
 341
 342         if (block->instance_count < instance)
 343                 return AE_BAD_PARAMETER;
 344
 345         /* Check GUID is a data block */
 346         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 347                 return AE_ERROR;
 348
 349         input.count = 1;
 350         input.pointer = wq_params;
 351         wq_params[0].type = ACPI_TYPE_INTEGER;
 352         wq_params[0].integer.value = instance;
 353
 354         /*
 355          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
 356          * enable collection.
 357          */
 358         if (block->flags & ACPI_WMI_EXPENSIVE) {
 359                 wc_input.count = 1;
 360                 wc_input.pointer = wc_params;
 361                 wc_params[0].type = ACPI_TYPE_INTEGER;
 362                 wc_params[0].integer.value = 1;
 363
 364                 strncat(wc_method, block->object_id, 2);
 365
 366                 /*
 367                  * Some GUIDs break the specification by declaring themselves
 368                  * expensive, but have no corresponding WCxx method. So we
 369                  * should not fail if this happens.
 370                  */
 371                 wc_status = acpi_get_handle(handle, wc_method, &wc_handle);
 372                 if (ACPI_SUCCESS(wc_status))
 373                         wc_status = acpi_evaluate_object(handle, wc_method,
 374                                 &wc_input, NULL);
 375         }
 376
 377         strcpy(method, "WQ");
 378         strncat(method, block->object_id, 2);
 379
 380         status = acpi_evaluate_object(handle, method, &input, out);
 381
 382         /*
 383          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
 384          * the WQxx method failed - we should disable collection anyway.
 385          */
 386         if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
 387                 wc_params[0].integer.value = 0;
 388                 status = acpi_evaluate_object(handle,
 389                 wc_method, &wc_input, NULL);
 390         }
 391
 392         return status;
 393 }
 394 EXPORT_SYMBOL_GPL(wmi_query_block);
 395
 396 /**
 397  * wmi_set_block - Write to a WMI block
 398  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 399  * @instance: Instance index
 400  * &in: Buffer containing new values for the data block
 401  *
 402  * Write the contents of the input buffer to an ACPI-WMI data block
 403  */
 404 acpi_status wmi_set_block(const char *guid_string, u8 instance,
 405 const struct acpi_buffer *in)
 406 {
 407         struct guid_block *block = NULL;
 408         struct wmi_block *wblock = NULL;
 409         acpi_handle handle;
 410         struct acpi_object_list input;
 411         union acpi_object params[2];
 412         char method[5] = "WS";
 413
 414         if (!guid_string || !in)
 415                 return AE_BAD_DATA;
 416
 417         if (!find_guid(guid_string, &wblock))
 418                 return AE_ERROR;
 419
 420         block = &wblock->gblock;
 421         handle = wblock->handle;
 422
 423         if (block->instance_count < instance)
 424                 return AE_BAD_PARAMETER;
 425
 426         /* Check GUID is a data block */
 427         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 428                 return AE_ERROR;
 429
 430         input.count = 2;
 431         input.pointer = params;
 432         params[0].type = ACPI_TYPE_INTEGER;
 433         params[0].integer.value = instance;
 434
 435         if (block->flags & ACPI_WMI_STRING) {
 436                 params[1].type = ACPI_TYPE_STRING;
 437         } else {
 438                 params[1].type = ACPI_TYPE_BUFFER;
 439         }
 440         params[1].buffer.length = in->length;
 441         params[1].buffer.pointer = in->pointer;
 442
 443         strncat(method, block->object_id, 2);
 444
 445         return acpi_evaluate_object(handle, method, &input, NULL);
 446 }
 447 EXPORT_SYMBOL_GPL(wmi_set_block);
 448
 449 /**
 450  * wmi_install_notify_handler - Register handler for WMI events
 451  * @handler: Function to handle notifications
 452  * @data: Data to be returned to handler when event is fired
 453  *
 454  * Register a handler for events sent to the ACPI-WMI mapper device.
 455  */
 456 acpi_status wmi_install_notify_handler(const char *guid,
 457 wmi_notify_handler handler, void *data)
 458 {
 459         struct wmi_block *block;
 460         acpi_status status;
 461
 462         if (!guid || !handler)
 463                 return AE_BAD_PARAMETER;
 464
 465         find_guid(guid, &block);
 466         if (!block)
 467                 return AE_NOT_EXIST;
 468
 469         if (block->handler)
 470                 return AE_ALREADY_ACQUIRED;
 471
 472         block->handler = handler;
 473         block->handler_data = data;
 474
 475         status = wmi_method_enable(block, 1);
 476
 477         return status;
 478 }
 479 EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
 480
 481 /**
 482  * wmi_uninstall_notify_handler - Unregister handler for WMI events
 483  *
 484  * Unregister handler for events sent to the ACPI-WMI mapper device.
 485  */
 486 acpi_status wmi_remove_notify_handler(const char *guid)
 487 {
 488         struct wmi_block *block;
 489         acpi_status status;
 490
 491         if (!guid)
 492                 return AE_BAD_PARAMETER;
 493
 494         find_guid(guid, &block);
 495         if (!block)
 496                 return AE_NOT_EXIST;
 497
 498         if (!block->handler)
 499                 return AE_NULL_ENTRY;
 500
 501         status = wmi_method_enable(block, 0);
 502
 503         block->handler = NULL;
 504         block->handler_data = NULL;
 505
 506         return status;
 507 }
 508 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
 509
 510 /**
 511  * wmi_get_event_data - Get WMI data associated with an event
 512  *
 513  * @event - Event to find
 514  * &out - Buffer to hold event data
 515  *
 516  * Returns extra data associated with an event in WMI.
 517  */
 518 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
 519 {
 520         struct acpi_object_list input;
 521         union acpi_object params[1];
 522         struct guid_block *gblock;
 523         struct wmi_block *wblock;
 524         struct list_head *p;
 525
 526         input.count = 1;
 527         input.pointer = params;
 528         params[0].type = ACPI_TYPE_INTEGER;
 529         params[0].integer.value = event;
 530
 531         list_for_each(p, &wmi_blocks.list) {
 532                 wblock = list_entry(p, struct wmi_block, list);
 533                 gblock = &wblock->gblock;
 534
 535                 if ((gblock->flags & ACPI_WMI_EVENT) &&
 536                         (gblock->notify_id == event))
 537                         return acpi_evaluate_object(wblock->handle, "_WED",
 538                                 &input, out);
 539         }
 540
 541         return AE_NOT_FOUND;
 542 }
 543 EXPORT_SYMBOL_GPL(wmi_get_event_data);
 544
 545 /**
 546  * wmi_has_guid - Check if a GUID is available
 547  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 548  *
 549  * Check if a given GUID is defined by _WDG
 550  */
 551 bool wmi_has_guid(const char *guid_string)
 552 {
 553         return find_guid(guid_string, NULL);
 554 }
 555 EXPORT_SYMBOL_GPL(wmi_has_guid);
 556
 557 /*
 558  * Parse the _WDG method for the GUID data blocks
 559  */
 560 static __init acpi_status parse_wdg(acpi_handle handle)
 561 {
 562         struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
 563         union acpi_object *obj;
 564         struct guid_block *gblock;
 565         struct wmi_block *wblock;
 566         acpi_status status;
 567         u32 i, total;
 568
 569         status = acpi_evaluate_object(handle, "_WDG", NULL, &out);
 570
 571         if (ACPI_FAILURE(status))
 572                 return status;
 573
 574         obj = (union acpi_object *) out.pointer;
 575
 576         if (obj->type != ACPI_TYPE_BUFFER)
 577                 return AE_ERROR;
 578
 579         total = obj->buffer.length / sizeof(struct guid_block);
 580
 581         gblock = kzalloc(obj->buffer.length, GFP_KERNEL);
 582         if (!gblock)
 583                 return AE_NO_MEMORY;
 584
 585         memcpy(gblock, obj->buffer.pointer, obj->buffer.length);
 586
 587         for (i = 0; i < total; i++) {
 588                 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
 589                 if (!wblock)
 590                         return AE_NO_MEMORY;
 591
 592                 wblock->gblock = gblock[i];
 593                 wblock->handle = handle;
 594                 list_add_tail(&wblock->list, &wmi_blocks.list);
 595         }
 596
 597         kfree(out.pointer);
 598         kfree(gblock);
 599
 600         return status;
 601 }
 602
 603 /*
 604  * WMI can have EmbeddedControl access regions. In which case, we just want to
 605  * hand these off to the EC driver.
 606  */
 607 static acpi_status
 608 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
 609                       u32 bits, acpi_integer * value,
 610                       void *handler_context, void *region_context)
 611 {
 612         int result = 0, i = 0;
 613         u8 temp = 0;
 614
 615         if ((address > 0xFF) || !value)
 616                 return AE_BAD_PARAMETER;
 617
 618         if (function != ACPI_READ && function != ACPI_WRITE)
 619                 return AE_BAD_PARAMETER;
 620
 621         if (bits != 8)
 622                 return AE_BAD_PARAMETER;
 623
 624         if (function == ACPI_READ) {
 625                 result = ec_read(address, &temp);
 626                 (*value) |= ((acpi_integer)temp) << i;
 627         } else {
 628                 temp = 0xff & ((*value) >> i);
 629                 result = ec_write(address, temp);
 630         }
 631
 632         switch (result) {
 633         case -EINVAL:
 634                 return AE_BAD_PARAMETER;
 635                 break;
 636         case -ENODEV:
 637                 return AE_NOT_FOUND;
 638                 break;
 639         case -ETIME:
 640                 return AE_TIME;
 641                 break;
 642         default:
 643                 return AE_OK;
 644         }
 645 }
 646
 647 static void acpi_wmi_notify(struct acpi_device *device, u32 event)
 648 {
 649         struct guid_block *block;
 650         struct wmi_block *wblock;
 651         struct list_head *p;
 652
 653         list_for_each(p, &wmi_blocks.list) {
 654                 wblock = list_entry(p, struct wmi_block, list);
 655                 block = &wblock->gblock;
 656
 657                 if ((block->flags & ACPI_WMI_EVENT) &&
 658                         (block->notify_id == event)) {
 659                         if (wblock->handler)
 660                                 wblock->handler(event, wblock->handler_data);
 661
 662                         acpi_bus_generate_netlink_event(
 663                                 device->pnp.device_class, dev_name(&device->dev),
 664                                 event, 0);
 665                         break;
 666                 }
 667         }
 668 }
 669
 670 static int acpi_wmi_remove(struct acpi_device *device, int type)
 671 {
 672         acpi_remove_address_space_handler(device->handle,
 673                                 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
 674
 675         return 0;
 676 }
 677
 678 static int __init acpi_wmi_add(struct acpi_device *device)
 679 {
 680         acpi_status status;
 681         int result = 0;
 682
 683         status = acpi_install_address_space_handler(device->handle,
 684                                                     ACPI_ADR_SPACE_EC,
 685                                                     &acpi_wmi_ec_space_handler,
 686                                                     NULL, NULL);
 687         if (ACPI_FAILURE(status))
 688                 return -ENODEV;
 689
 690         status = parse_wdg(device->handle);
 691         if (ACPI_FAILURE(status)) {
 692                 printk(KERN_ERR PREFIX "Error installing EC region handler\n");
 693                 return -ENODEV;
 694         }
 695
 696         return result;
 697 }
 698
 699 static int __init acpi_wmi_init(void)
 700 {
 701         int result;
 702
 703         INIT_LIST_HEAD(&wmi_blocks.list);
 704
 705         if (acpi_disabled)
 706                 return -ENODEV;
 707
 708         result = acpi_bus_register_driver(&acpi_wmi_driver);
 709
 710         if (result < 0) {
 711                 printk(KERN_INFO PREFIX "Error loading mapper\n");
 712         } else {
 713                 printk(KERN_INFO PREFIX "Mapper loaded\n");
 714         }
 715
 716         return result;
 717 }
 718
 719 static void __exit acpi_wmi_exit(void)
 720 {
 721         struct list_head *p, *tmp;
 722         struct wmi_block *wblock;
 723
 724         acpi_bus_unregister_driver(&acpi_wmi_driver);
 725
 726         list_for_each_safe(p, tmp, &wmi_blocks.list) {
 727                 wblock = list_entry(p, struct wmi_block, list);
 728
 729                 list_del(p);
 730                 kfree(wblock);
 731         }
 732
 733         printk(KERN_INFO PREFIX "Mapper unloaded\n");
 734 }
 735
 736 subsys_initcall(acpi_wmi_init);
 737 module_exit(acpi_wmi_exit);