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   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/device.h>
  34 #include <linux/list.h>
  35 #include <linux/acpi.h>
  36 #include <acpi/acpi_bus.h>
  37 #include <acpi/acpi_drivers.h>
  38
  39 ACPI_MODULE_NAME("wmi");
  40 MODULE_AUTHOR("Carlos Corbacho");
  41 MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
  42 MODULE_LICENSE("GPL");
  43
  44 #define ACPI_WMI_CLASS "wmi"
  45
  46 #define PREFIX "ACPI: WMI: "
  47
  48 static DEFINE_MUTEX(wmi_data_lock);
  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 static struct wmi_block wmi_blocks;
  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 int acpi_wmi_remove(struct acpi_device *device, int type);
  84 static int acpi_wmi_add(struct acpi_device *device);
  85 static void acpi_wmi_notify(struct acpi_device *device, u32 event);
  86
  87 static const struct acpi_device_id wmi_device_ids[] = {
  88         {"PNP0C14", 0},
  89         {"pnp0c14", 0},
  90         {"", 0},
  91 };
  92 MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
  93
  94 static struct acpi_driver acpi_wmi_driver = {
  95         .name = "wmi",
  96         .class = ACPI_WMI_CLASS,
  97         .ids = wmi_device_ids,
  98         .ops = {
  99                 .add = acpi_wmi_add,
 100                 .remove = acpi_wmi_remove,
 101                 .notify = acpi_wmi_notify,
 102                 },
 103 };
 104
 105 /*
 106  * GUID parsing functions
 107  */
 108
 109 /**
 110  * wmi_parse_hexbyte - Convert a ASCII hex number to a byte
 111  * @src:  Pointer to at least 2 characters to convert.
 112  *
 113  * Convert a two character ASCII hex string to a number.
 114  *
 115  * Return:  0-255  Success, the byte was parsed correctly
 116  *          -1     Error, an invalid character was supplied
 117  */
 118 static int wmi_parse_hexbyte(const u8 *src)
 119 {
 120         unsigned int x; /* For correct wrapping */
 121         int h;
 122
 123         /* high part */
 124         x = src[0];
 125         if (x - '0' <= '9' - '0') {
 126                 h = x - '0';
 127         } else if (x - 'a' <= 'f' - 'a') {
 128                 h = x - 'a' + 10;
 129         } else if (x - 'A' <= 'F' - 'A') {
 130                 h = x - 'A' + 10;
 131         } else {
 132                 return -1;
 133         }
 134         h <<= 4;
 135
 136         /* low part */
 137         x = src[1];
 138         if (x - '0' <= '9' - '0')
 139                 return h | (x - '0');
 140         if (x - 'a' <= 'f' - 'a')
 141                 return h | (x - 'a' + 10);
 142         if (x - 'A' <= 'F' - 'A')
 143                 return h | (x - 'A' + 10);
 144         return -1;
 145 }
 146
 147 /**
 148  * wmi_swap_bytes - Rearrange GUID bytes to match GUID binary
 149  * @src:   Memory block holding binary GUID (16 bytes)
 150  * @dest:  Memory block to hold byte swapped binary GUID (16 bytes)
 151  *
 152  * Byte swap a binary GUID to match it's real GUID value
 153  */
 154 static void wmi_swap_bytes(u8 *src, u8 *dest)
 155 {
 156         int i;
 157
 158         for (i = 0; i <= 3; i++)
 159                 memcpy(dest + i, src + (3 - i), 1);
 160
 161         for (i = 0; i <= 1; i++)
 162                 memcpy(dest + 4 + i, src + (5 - i), 1);
 163
 164         for (i = 0; i <= 1; i++)
 165                 memcpy(dest + 6 + i, src + (7 - i), 1);
 166
 167         memcpy(dest + 8, src + 8, 8);
 168 }
 169
 170 /**
 171  * wmi_parse_guid - Convert GUID from ASCII to binary
 172  * @src:   36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 173  * @dest:  Memory block to hold binary GUID (16 bytes)
 174  *
 175  * N.B. The GUID need not be NULL terminated.
 176  *
 177  * Return:  'true'   @dest contains binary GUID
 178  *          'false'  @dest contents are undefined
 179  */
 180 static bool wmi_parse_guid(const u8 *src, u8 *dest)
 181 {
 182         static const int size[] = { 4, 2, 2, 2, 6 };
 183         int i, j, v;
 184
 185         if (src[8]  != '-' || src[13] != '-' ||
 186                 src[18] != '-' || src[23] != '-')
 187                 return false;
 188
 189         for (j = 0; j < 5; j++, src++) {
 190                 for (i = 0; i < size[j]; i++, src += 2, *dest++ = v) {
 191                         v = wmi_parse_hexbyte(src);
 192                         if (v < 0)
 193                                 return false;
 194                 }
 195         }
 196
 197         return true;
 198 }
 199
 200 /*
 201  * Convert a raw GUID to the ACII string representation
 202  */
 203 static int wmi_gtoa(const char *in, char *out)
 204 {
 205         int i;
 206
 207         for (i = 3; i >= 0; i--)
 208                 out += sprintf(out, "%02X", in[i] & 0xFF);
 209
 210         out += sprintf(out, "-");
 211         out += sprintf(out, "%02X", in[5] & 0xFF);
 212         out += sprintf(out, "%02X", in[4] & 0xFF);
 213         out += sprintf(out, "-");
 214         out += sprintf(out, "%02X", in[7] & 0xFF);
 215         out += sprintf(out, "%02X", in[6] & 0xFF);
 216         out += sprintf(out, "-");
 217         out += sprintf(out, "%02X", in[8] & 0xFF);
 218         out += sprintf(out, "%02X", in[9] & 0xFF);
 219         out += sprintf(out, "-");
 220
 221         for (i = 10; i <= 15; i++)
 222                 out += sprintf(out, "%02X", in[i] & 0xFF);
 223
 224         out = '\0';
 225         return 0;
 226 }
 227
 228 static bool find_guid(const char *guid_string, struct wmi_block **out)
 229 {
 230         char tmp[16], guid_input[16];
 231         struct wmi_block *wblock;
 232         struct guid_block *block;
 233         struct list_head *p;
 234
 235         wmi_parse_guid(guid_string, tmp);
 236         wmi_swap_bytes(tmp, guid_input);
 237
 238         list_for_each(p, &wmi_blocks.list) {
 239                 wblock = list_entry(p, struct wmi_block, list);
 240                 block = &wblock->gblock;
 241
 242                 if (memcmp(block->guid, guid_input, 16) == 0) {
 243                         if (out)
 244                                 *out = wblock;
 245                         return 1;
 246                 }
 247         }
 248         return 0;
 249 }
 250
 251 static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable)
 252 {
 253         struct guid_block *block = NULL;
 254         char method[5];
 255         struct acpi_object_list input;
 256         union acpi_object params[1];
 257         acpi_status status;
 258         acpi_handle handle;
 259
 260         block = &wblock->gblock;
 261         handle = wblock->handle;
 262
 263         if (!block)
 264                 return AE_NOT_EXIST;
 265
 266         input.count = 1;
 267         input.pointer = params;
 268         params[0].type = ACPI_TYPE_INTEGER;
 269         params[0].integer.value = enable;
 270
 271         snprintf(method, 5, "WE%02X", block->notify_id);
 272         status = acpi_evaluate_object(handle, method, &input, NULL);
 273
 274         if (status != AE_OK && status != AE_NOT_FOUND)
 275                 return status;
 276         else
 277                 return AE_OK;
 278 }
 279
 280 /*
 281  * Exported WMI functions
 282  */
 283 /**
 284  * wmi_evaluate_method - Evaluate a WMI method
 285  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 286  * @instance: Instance index
 287  * @method_id: Method ID to call
 288  * &in: Buffer containing input for the method call
 289  * &out: Empty buffer to return the method results
 290  *
 291  * Call an ACPI-WMI method
 292  */
 293 acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
 294 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
 295 {
 296         struct guid_block *block = NULL;
 297         struct wmi_block *wblock = NULL;
 298         acpi_handle handle;
 299         acpi_status status;
 300         struct acpi_object_list input;
 301         union acpi_object params[3];
 302         char method[5] = "WM";
 303
 304         if (!find_guid(guid_string, &wblock))
 305                 return AE_ERROR;
 306
 307         block = &wblock->gblock;
 308         handle = wblock->handle;
 309
 310         if (!(block->flags & ACPI_WMI_METHOD))
 311                 return AE_BAD_DATA;
 312
 313         if (block->instance_count < instance)
 314                 return AE_BAD_PARAMETER;
 315
 316         input.count = 2;
 317         input.pointer = params;
 318         params[0].type = ACPI_TYPE_INTEGER;
 319         params[0].integer.value = instance;
 320         params[1].type = ACPI_TYPE_INTEGER;
 321         params[1].integer.value = method_id;
 322
 323         if (in) {
 324                 input.count = 3;
 325
 326                 if (block->flags & ACPI_WMI_STRING) {
 327                         params[2].type = ACPI_TYPE_STRING;
 328                 } else {
 329                         params[2].type = ACPI_TYPE_BUFFER;
 330                 }
 331                 params[2].buffer.length = in->length;
 332                 params[2].buffer.pointer = in->pointer;
 333         }
 334
 335         strncat(method, block->object_id, 2);
 336
 337         status = acpi_evaluate_object(handle, method, &input, out);
 338
 339         return status;
 340 }
 341 EXPORT_SYMBOL_GPL(wmi_evaluate_method);
 342
 343 /**
 344  * wmi_query_block - Return contents of a WMI block
 345  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 346  * @instance: Instance index
 347  * &out: Empty buffer to return the contents of the data block to
 348  *
 349  * Return the contents of an ACPI-WMI data block to a buffer
 350  */
 351 acpi_status wmi_query_block(const char *guid_string, u8 instance,
 352 struct acpi_buffer *out)
 353 {
 354         struct guid_block *block = NULL;
 355         struct wmi_block *wblock = NULL;
 356         acpi_handle handle, wc_handle;
 357         acpi_status status, wc_status = AE_ERROR;
 358         struct acpi_object_list input, wc_input;
 359         union acpi_object wc_params[1], wq_params[1];
 360         char method[5];
 361         char wc_method[5] = "WC";
 362
 363         if (!guid_string || !out)
 364                 return AE_BAD_PARAMETER;
 365
 366         if (!find_guid(guid_string, &wblock))
 367                 return AE_ERROR;
 368
 369         block = &wblock->gblock;
 370         handle = wblock->handle;
 371
 372         if (block->instance_count < instance)
 373                 return AE_BAD_PARAMETER;
 374
 375         /* Check GUID is a data block */
 376         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 377                 return AE_ERROR;
 378
 379         input.count = 1;
 380         input.pointer = wq_params;
 381         wq_params[0].type = ACPI_TYPE_INTEGER;
 382         wq_params[0].integer.value = instance;
 383
 384         /*
 385          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
 386          * enable collection.
 387          */
 388         if (block->flags & ACPI_WMI_EXPENSIVE) {
 389                 wc_input.count = 1;
 390                 wc_input.pointer = wc_params;
 391                 wc_params[0].type = ACPI_TYPE_INTEGER;
 392                 wc_params[0].integer.value = 1;
 393
 394                 strncat(wc_method, block->object_id, 2);
 395
 396                 /*
 397                  * Some GUIDs break the specification by declaring themselves
 398                  * expensive, but have no corresponding WCxx method. So we
 399                  * should not fail if this happens.
 400                  */
 401                 wc_status = acpi_get_handle(handle, wc_method, &wc_handle);
 402                 if (ACPI_SUCCESS(wc_status))
 403                         wc_status = acpi_evaluate_object(handle, wc_method,
 404                                 &wc_input, NULL);
 405         }
 406
 407         strcpy(method, "WQ");
 408         strncat(method, block->object_id, 2);
 409
 410         status = acpi_evaluate_object(handle, method, &input, out);
 411
 412         /*
 413          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
 414          * the WQxx method failed - we should disable collection anyway.
 415          */
 416         if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
 417                 wc_params[0].integer.value = 0;
 418                 status = acpi_evaluate_object(handle,
 419                 wc_method, &wc_input, NULL);
 420         }
 421
 422         return status;
 423 }
 424 EXPORT_SYMBOL_GPL(wmi_query_block);
 425
 426 /**
 427  * wmi_set_block - Write to a WMI block
 428  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 429  * @instance: Instance index
 430  * &in: Buffer containing new values for the data block
 431  *
 432  * Write the contents of the input buffer to an ACPI-WMI data block
 433  */
 434 acpi_status wmi_set_block(const char *guid_string, u8 instance,
 435 const struct acpi_buffer *in)
 436 {
 437         struct guid_block *block = NULL;
 438         struct wmi_block *wblock = NULL;
 439         acpi_handle handle;
 440         struct acpi_object_list input;
 441         union acpi_object params[2];
 442         char method[5] = "WS";
 443
 444         if (!guid_string || !in)
 445                 return AE_BAD_DATA;
 446
 447         if (!find_guid(guid_string, &wblock))
 448                 return AE_ERROR;
 449
 450         block = &wblock->gblock;
 451         handle = wblock->handle;
 452
 453         if (block->instance_count < instance)
 454                 return AE_BAD_PARAMETER;
 455
 456         /* Check GUID is a data block */
 457         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 458                 return AE_ERROR;
 459
 460         input.count = 2;
 461         input.pointer = params;
 462         params[0].type = ACPI_TYPE_INTEGER;
 463         params[0].integer.value = instance;
 464
 465         if (block->flags & ACPI_WMI_STRING) {
 466                 params[1].type = ACPI_TYPE_STRING;
 467         } else {
 468                 params[1].type = ACPI_TYPE_BUFFER;
 469         }
 470         params[1].buffer.length = in->length;
 471         params[1].buffer.pointer = in->pointer;
 472
 473         strncat(method, block->object_id, 2);
 474
 475         return acpi_evaluate_object(handle, method, &input, NULL);
 476 }
 477 EXPORT_SYMBOL_GPL(wmi_set_block);
 478
 479 /**
 480  * wmi_install_notify_handler - Register handler for WMI events
 481  * @handler: Function to handle notifications
 482  * @data: Data to be returned to handler when event is fired
 483  *
 484  * Register a handler for events sent to the ACPI-WMI mapper device.
 485  */
 486 acpi_status wmi_install_notify_handler(const char *guid,
 487 wmi_notify_handler handler, void *data)
 488 {
 489         struct wmi_block *block;
 490         acpi_status status;
 491
 492         if (!guid || !handler)
 493                 return AE_BAD_PARAMETER;
 494
 495         if (!find_guid(guid, &block))
 496                 return AE_NOT_EXIST;
 497
 498         if (block->handler)
 499                 return AE_ALREADY_ACQUIRED;
 500
 501         block->handler = handler;
 502         block->handler_data = data;
 503
 504         status = wmi_method_enable(block, 1);
 505
 506         return status;
 507 }
 508 EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
 509
 510 /**
 511  * wmi_uninstall_notify_handler - Unregister handler for WMI events
 512  *
 513  * Unregister handler for events sent to the ACPI-WMI mapper device.
 514  */
 515 acpi_status wmi_remove_notify_handler(const char *guid)
 516 {
 517         struct wmi_block *block;
 518         acpi_status status;
 519
 520         if (!guid)
 521                 return AE_BAD_PARAMETER;
 522
 523         if (!find_guid(guid, &block))
 524                 return AE_NOT_EXIST;
 525
 526         if (!block->handler)
 527                 return AE_NULL_ENTRY;
 528
 529         status = wmi_method_enable(block, 0);
 530
 531         block->handler = NULL;
 532         block->handler_data = NULL;
 533
 534         return status;
 535 }
 536 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
 537
 538 /**
 539  * wmi_get_event_data - Get WMI data associated with an event
 540  *
 541  * @event: Event to find
 542  * @out: Buffer to hold event data. out->pointer should be freed with kfree()
 543  *
 544  * Returns extra data associated with an event in WMI.
 545  */
 546 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
 547 {
 548         struct acpi_object_list input;
 549         union acpi_object params[1];
 550         struct guid_block *gblock;
 551         struct wmi_block *wblock;
 552         struct list_head *p;
 553
 554         input.count = 1;
 555         input.pointer = params;
 556         params[0].type = ACPI_TYPE_INTEGER;
 557         params[0].integer.value = event;
 558
 559         list_for_each(p, &wmi_blocks.list) {
 560                 wblock = list_entry(p, struct wmi_block, list);
 561                 gblock = &wblock->gblock;
 562
 563                 if ((gblock->flags & ACPI_WMI_EVENT) &&
 564                         (gblock->notify_id == event))
 565                         return acpi_evaluate_object(wblock->handle, "_WED",
 566                                 &input, out);
 567         }
 568
 569         return AE_NOT_FOUND;
 570 }
 571 EXPORT_SYMBOL_GPL(wmi_get_event_data);
 572
 573 /**
 574  * wmi_has_guid - Check if a GUID is available
 575  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 576  *
 577  * Check if a given GUID is defined by _WDG
 578  */
 579 bool wmi_has_guid(const char *guid_string)
 580 {
 581         return find_guid(guid_string, NULL);
 582 }
 583 EXPORT_SYMBOL_GPL(wmi_has_guid);
 584
 585 /*
 586  * sysfs interface
 587  */
 588 static ssize_t show_modalias(struct device *dev, struct device_attribute *attr,
 589                              char *buf)
 590 {
 591         char guid_string[37];
 592         struct wmi_block *wblock;
 593
 594         wblock = dev_get_drvdata(dev);
 595         if (!wblock)
 596                 return -ENOMEM;
 597
 598         wmi_gtoa(wblock->gblock.guid, guid_string);
 599
 600         return sprintf(buf, "wmi:%s\n", guid_string);
 601 }
 602 static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL);
 603
 604 static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 605 {
 606         char guid_string[37];
 607
 608         struct wmi_block *wblock;
 609
 610         if (add_uevent_var(env, "MODALIAS="))
 611                 return -ENOMEM;
 612
 613         wblock = dev_get_drvdata(dev);
 614         if (!wblock)
 615                 return -ENOMEM;
 616
 617         wmi_gtoa(wblock->gblock.guid, guid_string);
 618
 619         strcpy(&env->buf[env->buflen - 1], "wmi:");
 620         memcpy(&env->buf[env->buflen - 1 + 4], guid_string, 36);
 621         env->buflen += 40;
 622
 623         return 0;
 624 }
 625
 626 static void wmi_dev_free(struct device *dev)
 627 {
 628         kfree(dev);
 629 }
 630
 631 static struct class wmi_class = {
 632         .name = "wmi",
 633         .dev_release = wmi_dev_free,
 634         .dev_uevent = wmi_dev_uevent,
 635 };
 636
 637 static int wmi_create_devs(void)
 638 {
 639         int result;
 640         char guid_string[37];
 641         struct guid_block *gblock;
 642         struct wmi_block *wblock;
 643         struct list_head *p;
 644         struct device *guid_dev;
 645
 646         /* Create devices for all the GUIDs */
 647         list_for_each(p, &wmi_blocks.list) {
 648                 wblock = list_entry(p, struct wmi_block, list);
 649
 650                 guid_dev = kzalloc(sizeof(struct device), GFP_KERNEL);
 651                 if (!guid_dev)
 652                         return -ENOMEM;
 653
 654                 wblock->dev = guid_dev;
 655
 656                 guid_dev->class = &wmi_class;
 657                 dev_set_drvdata(guid_dev, wblock);
 658
 659                 gblock = &wblock->gblock;
 660
 661                 wmi_gtoa(gblock->guid, guid_string);
 662                 dev_set_name(guid_dev, guid_string);
 663
 664                 result = device_register(guid_dev);
 665                 if (result)
 666                         return result;
 667
 668                 result = device_create_file(guid_dev, &dev_attr_modalias);
 669                 if (result)
 670                         return result;
 671         }
 672
 673         return 0;
 674 }
 675
 676 static void wmi_remove_devs(void)
 677 {
 678         struct guid_block *gblock;
 679         struct wmi_block *wblock;
 680         struct list_head *p;
 681         struct device *guid_dev;
 682
 683         /* Delete devices for all the GUIDs */
 684         list_for_each(p, &wmi_blocks.list) {
 685                 wblock = list_entry(p, struct wmi_block, list);
 686
 687                 guid_dev = wblock->dev;
 688                 gblock = &wblock->gblock;
 689
 690                 device_remove_file(guid_dev, &dev_attr_modalias);
 691
 692                 device_unregister(guid_dev);
 693         }
 694 }
 695
 696 static void wmi_class_exit(void)
 697 {
 698         wmi_remove_devs();
 699         class_unregister(&wmi_class);
 700 }
 701
 702 static int wmi_class_init(void)
 703 {
 704         int ret;
 705
 706         ret = class_register(&wmi_class);
 707         if (ret)
 708                 return ret;
 709
 710         ret = wmi_create_devs();
 711         if (ret)
 712                 wmi_class_exit();
 713
 714         return ret;
 715 }
 716
 717 /*
 718  * Parse the _WDG method for the GUID data blocks
 719  */
 720 static __init acpi_status parse_wdg(acpi_handle handle)
 721 {
 722         struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
 723         union acpi_object *obj;
 724         struct guid_block *gblock;
 725         struct wmi_block *wblock;
 726         acpi_status status;
 727         u32 i, total;
 728
 729         status = acpi_evaluate_object(handle, "_WDG", NULL, &out);
 730
 731         if (ACPI_FAILURE(status))
 732                 return status;
 733
 734         obj = (union acpi_object *) out.pointer;
 735
 736         if (obj->type != ACPI_TYPE_BUFFER)
 737                 return AE_ERROR;
 738
 739         total = obj->buffer.length / sizeof(struct guid_block);
 740
 741         gblock = kzalloc(obj->buffer.length, GFP_KERNEL);
 742         if (!gblock)
 743                 return AE_NO_MEMORY;
 744
 745         memcpy(gblock, obj->buffer.pointer, obj->buffer.length);
 746
 747         for (i = 0; i < total; i++) {
 748                 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
 749                 if (!wblock)
 750                         return AE_NO_MEMORY;
 751
 752                 wblock->gblock = gblock[i];
 753                 wblock->handle = handle;
 754                 list_add_tail(&wblock->list, &wmi_blocks.list);
 755         }
 756
 757         kfree(out.pointer);
 758         kfree(gblock);
 759
 760         return status;
 761 }
 762
 763 /*
 764  * WMI can have EmbeddedControl access regions. In which case, we just want to
 765  * hand these off to the EC driver.
 766  */
 767 static acpi_status
 768 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
 769                       u32 bits, acpi_integer * value,
 770                       void *handler_context, void *region_context)
 771 {
 772         int result = 0, i = 0;
 773         u8 temp = 0;
 774
 775         if ((address > 0xFF) || !value)
 776                 return AE_BAD_PARAMETER;
 777
 778         if (function != ACPI_READ && function != ACPI_WRITE)
 779                 return AE_BAD_PARAMETER;
 780
 781         if (bits != 8)
 782                 return AE_BAD_PARAMETER;
 783
 784         if (function == ACPI_READ) {
 785                 result = ec_read(address, &temp);
 786                 (*value) |= ((acpi_integer)temp) << i;
 787         } else {
 788                 temp = 0xff & ((*value) >> i);
 789                 result = ec_write(address, temp);
 790         }
 791
 792         switch (result) {
 793         case -EINVAL:
 794                 return AE_BAD_PARAMETER;
 795                 break;
 796         case -ENODEV:
 797                 return AE_NOT_FOUND;
 798                 break;
 799         case -ETIME:
 800                 return AE_TIME;
 801                 break;
 802         default:
 803                 return AE_OK;
 804         }
 805 }
 806
 807 static void acpi_wmi_notify(struct acpi_device *device, u32 event)
 808 {
 809         struct guid_block *block;
 810         struct wmi_block *wblock;
 811         struct list_head *p;
 812
 813         list_for_each(p, &wmi_blocks.list) {
 814                 wblock = list_entry(p, struct wmi_block, list);
 815                 block = &wblock->gblock;
 816
 817                 if ((block->flags & ACPI_WMI_EVENT) &&
 818                         (block->notify_id == event)) {
 819                         if (wblock->handler)
 820                                 wblock->handler(event, wblock->handler_data);
 821
 822                         acpi_bus_generate_netlink_event(
 823                                 device->pnp.device_class, dev_name(&device->dev),
 824                                 event, 0);
 825                         break;
 826                 }
 827         }
 828 }
 829
 830 static int acpi_wmi_remove(struct acpi_device *device, int type)
 831 {
 832         acpi_remove_address_space_handler(device->handle,
 833                                 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
 834
 835         return 0;
 836 }
 837
 838 static int __init acpi_wmi_add(struct acpi_device *device)
 839 {
 840         acpi_status status;
 841         int result = 0;
 842
 843         status = acpi_install_address_space_handler(device->handle,
 844                                                     ACPI_ADR_SPACE_EC,
 845                                                     &acpi_wmi_ec_space_handler,
 846                                                     NULL, NULL);
 847         if (ACPI_FAILURE(status))
 848                 return -ENODEV;
 849
 850         status = parse_wdg(device->handle);
 851         if (ACPI_FAILURE(status)) {
 852                 printk(KERN_ERR PREFIX "Error installing EC region handler\n");
 853                 return -ENODEV;
 854         }
 855
 856         return result;
 857 }
 858
 859 static int __init acpi_wmi_init(void)
 860 {
 861         int result;
 862
 863         INIT_LIST_HEAD(&wmi_blocks.list);
 864
 865         if (acpi_disabled)
 866                 return -ENODEV;
 867
 868         result = acpi_bus_register_driver(&acpi_wmi_driver);
 869
 870         if (result < 0) {
 871                 printk(KERN_INFO PREFIX "Error loading mapper\n");
 872                 return -ENODEV;
 873         }
 874
 875         result = wmi_class_init();
 876         if (result) {
 877                 acpi_bus_unregister_driver(&acpi_wmi_driver);
 878                 return result;
 879         }
 880
 881         printk(KERN_INFO PREFIX "Mapper loaded\n");
 882
 883         return result;
 884 }
 885
 886 static void __exit acpi_wmi_exit(void)
 887 {
 888         struct list_head *p, *tmp;
 889         struct wmi_block *wblock;
 890
 891         wmi_class_exit();
 892
 893         acpi_bus_unregister_driver(&acpi_wmi_driver);
 894
 895         list_for_each_safe(p, tmp, &wmi_blocks.list) {
 896                 wblock = list_entry(p, struct wmi_block, list);
 897
 898                 list_del(p);
 899                 kfree(wblock);
 900         }
 901
 902         printk(KERN_INFO PREFIX "Mapper unloaded\n");
 903 }
 904
 905 subsys_initcall(acpi_wmi_init);
 906 module_exit(acpi_wmi_exit);