drivers/platform/x86/wmi.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  ACPI-WMI mapping driver
   4  *
   5  *  Copyright (C) 2007-2008 Carlos Corbacho <carlos@strangeworlds.co.uk>
   6  *
   7  *  GUID parsing code from ldm.c is:
   8  *   Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
   9  *   Copyright (c) 2001-2007 Anton Altaparmakov
  10  *   Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
  11  *
  12  *  WMI bus infrastructure by Andrew Lutomirski and Darren Hart:
  13  *    Copyright (C) 2015 Andrew Lutomirski
  14  *    Copyright (C) 2017 VMware, Inc. All Rights Reserved.
  15  */
  16
  17 #define pr_fmt(fmt)     KBUILD_MODNAME ": " fmt
  18
  19 #include <linux/acpi.h>
  20 #include <linux/device.h>
  21 #include <linux/init.h>
  22 #include <linux/kernel.h>
  23 #include <linux/list.h>
  24 #include <linux/miscdevice.h>
  25 #include <linux/module.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/slab.h>
  28 #include <linux/types.h>
  29 #include <linux/uaccess.h>
  30 #include <linux/uuid.h>
  31 #include <linux/wmi.h>
  32 #include <uapi/linux/wmi.h>
  33
  34 ACPI_MODULE_NAME("wmi");
  35 MODULE_AUTHOR("Carlos Corbacho");
  36 MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
  37 MODULE_LICENSE("GPL");
  38
  39 static LIST_HEAD(wmi_block_list);
  40
  41 struct guid_block {
  42         char guid[16];
  43         union {
  44                 char object_id[2];
  45                 struct {
  46                         unsigned char notify_id;
  47                         unsigned char reserved;
  48                 };
  49         };
  50         u8 instance_count;
  51         u8 flags;
  52 };
  53
  54 struct wmi_block {
  55         struct wmi_device dev;
  56         struct list_head list;
  57         struct guid_block gblock;
  58         struct miscdevice char_dev;
  59         struct mutex char_mutex;
  60         struct acpi_device *acpi_device;
  61         wmi_notify_handler handler;
  62         void *handler_data;
  63         u64 req_buf_size;
  64
  65         bool read_takes_no_args;
  66 };
  67
  68
  69 /*
  70  * If the GUID data block is marked as expensive, we must enable and
  71  * explicitily disable data collection.
  72  */
  73 #define ACPI_WMI_EXPENSIVE   0x1
  74 #define ACPI_WMI_METHOD      0x2        /* GUID is a method */
  75 #define ACPI_WMI_STRING      0x4        /* GUID takes & returns a string */
  76 #define ACPI_WMI_EVENT       0x8        /* GUID is an event */
  77
  78 static bool debug_event;
  79 module_param(debug_event, bool, 0444);
  80 MODULE_PARM_DESC(debug_event,
  81                  "Log WMI Events [0/1]");
  82
  83 static bool debug_dump_wdg;
  84 module_param(debug_dump_wdg, bool, 0444);
  85 MODULE_PARM_DESC(debug_dump_wdg,
  86                  "Dump available WMI interfaces [0/1]");
  87
  88 static int acpi_wmi_remove(struct platform_device *device);
  89 static int acpi_wmi_probe(struct platform_device *device);
  90
  91 static const struct acpi_device_id wmi_device_ids[] = {
  92         {"PNP0C14", 0},
  93         {"pnp0c14", 0},
  94         {"", 0},
  95 };
  96 MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
  97
  98 static struct platform_driver acpi_wmi_driver = {
  99         .driver = {
 100                 .name = "acpi-wmi",
 101                 .acpi_match_table = wmi_device_ids,
 102         },
 103         .probe = acpi_wmi_probe,
 104         .remove = acpi_wmi_remove,
 105 };
 106
 107 /*
 108  * GUID parsing functions
 109  */
 110
 111 static bool find_guid(const char *guid_string, struct wmi_block **out)
 112 {
 113         uuid_le guid_input;
 114         struct wmi_block *wblock;
 115         struct guid_block *block;
 116
 117         if (uuid_le_to_bin(guid_string, &guid_input))
 118                 return false;
 119
 120         list_for_each_entry(wblock, &wmi_block_list, list) {
 121                 block = &wblock->gblock;
 122
 123                 if (memcmp(block->guid, &guid_input, 16) == 0) {
 124                         if (out)
 125                                 *out = wblock;
 126                         return true;
 127                 }
 128         }
 129         return false;
 130 }
 131
 132 static const void *find_guid_context(struct wmi_block *wblock,
 133                                       struct wmi_driver *wdriver)
 134 {
 135         const struct wmi_device_id *id;
 136         uuid_le guid_input;
 137
 138         if (wblock == NULL || wdriver == NULL)
 139                 return NULL;
 140         if (wdriver->id_table == NULL)
 141                 return NULL;
 142
 143         id = wdriver->id_table;
 144         while (*id->guid_string) {
 145                 if (uuid_le_to_bin(id->guid_string, &guid_input))
 146                         continue;
 147                 if (!memcmp(wblock->gblock.guid, &guid_input, 16))
 148                         return id->context;
 149                 id++;
 150         }
 151         return NULL;
 152 }
 153
 154 static int get_subobj_info(acpi_handle handle, const char *pathname,
 155                            struct acpi_device_info **info)
 156 {
 157         struct acpi_device_info *dummy_info, **info_ptr;
 158         acpi_handle subobj_handle;
 159         acpi_status status;
 160
 161         status = acpi_get_handle(handle, (char *)pathname, &subobj_handle);
 162         if (status == AE_NOT_FOUND)
 163                 return -ENOENT;
 164         else if (ACPI_FAILURE(status))
 165                 return -EIO;
 166
 167         info_ptr = info ? info : &dummy_info;
 168         status = acpi_get_object_info(subobj_handle, info_ptr);
 169         if (ACPI_FAILURE(status))
 170                 return -EIO;
 171
 172         if (!info)
 173                 kfree(dummy_info);
 174
 175         return 0;
 176 }
 177
 178 static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable)
 179 {
 180         struct guid_block *block = NULL;
 181         char method[5];
 182         acpi_status status;
 183         acpi_handle handle;
 184
 185         block = &wblock->gblock;
 186         handle = wblock->acpi_device->handle;
 187
 188         snprintf(method, 5, "WE%02X", block->notify_id);
 189         status = acpi_execute_simple_method(handle, method, enable);
 190
 191         if (status != AE_OK && status != AE_NOT_FOUND)
 192                 return status;
 193         else
 194                 return AE_OK;
 195 }
 196
 197 /*
 198  * Exported WMI functions
 199  */
 200
 201 /**
 202  * set_required_buffer_size - Sets the buffer size needed for performing IOCTL
 203  * @wdev: A wmi bus device from a driver
 204  * @instance: Instance index
 205  *
 206  * Allocates memory needed for buffer, stores the buffer size in that memory
 207  */
 208 int set_required_buffer_size(struct wmi_device *wdev, u64 length)
 209 {
 210         struct wmi_block *wblock;
 211
 212         wblock = container_of(wdev, struct wmi_block, dev);
 213         wblock->req_buf_size = length;
 214
 215         return 0;
 216 }
 217 EXPORT_SYMBOL_GPL(set_required_buffer_size);
 218
 219 /**
 220  * wmi_evaluate_method - Evaluate a WMI method
 221  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 222  * @instance: Instance index
 223  * @method_id: Method ID to call
 224  * &in: Buffer containing input for the method call
 225  * &out: Empty buffer to return the method results
 226  *
 227  * Call an ACPI-WMI method
 228  */
 229 acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
 230 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
 231 {
 232         struct wmi_block *wblock = NULL;
 233
 234         if (!find_guid(guid_string, &wblock))
 235                 return AE_ERROR;
 236         return wmidev_evaluate_method(&wblock->dev, instance, method_id,
 237                                       in, out);
 238 }
 239 EXPORT_SYMBOL_GPL(wmi_evaluate_method);
 240
 241 /**
 242  * wmidev_evaluate_method - Evaluate a WMI method
 243  * @wdev: A wmi bus device from a driver
 244  * @instance: Instance index
 245  * @method_id: Method ID to call
 246  * &in: Buffer containing input for the method call
 247  * &out: Empty buffer to return the method results
 248  *
 249  * Call an ACPI-WMI method
 250  */
 251 acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance,
 252         u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
 253 {
 254         struct guid_block *block = NULL;
 255         struct wmi_block *wblock = NULL;
 256         acpi_handle handle;
 257         acpi_status status;
 258         struct acpi_object_list input;
 259         union acpi_object params[3];
 260         char method[5] = "WM";
 261
 262         wblock = container_of(wdev, struct wmi_block, dev);
 263         block = &wblock->gblock;
 264         handle = wblock->acpi_device->handle;
 265
 266         if (!(block->flags & ACPI_WMI_METHOD))
 267                 return AE_BAD_DATA;
 268
 269         if (block->instance_count <= instance)
 270                 return AE_BAD_PARAMETER;
 271
 272         input.count = 2;
 273         input.pointer = params;
 274         params[0].type = ACPI_TYPE_INTEGER;
 275         params[0].integer.value = instance;
 276         params[1].type = ACPI_TYPE_INTEGER;
 277         params[1].integer.value = method_id;
 278
 279         if (in) {
 280                 input.count = 3;
 281
 282                 if (block->flags & ACPI_WMI_STRING) {
 283                         params[2].type = ACPI_TYPE_STRING;
 284                 } else {
 285                         params[2].type = ACPI_TYPE_BUFFER;
 286                 }
 287                 params[2].buffer.length = in->length;
 288                 params[2].buffer.pointer = in->pointer;
 289         }
 290
 291         strncat(method, block->object_id, 2);
 292
 293         status = acpi_evaluate_object(handle, method, &input, out);
 294
 295         return status;
 296 }
 297 EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
 298
 299 static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
 300                                  struct acpi_buffer *out)
 301 {
 302         struct guid_block *block = NULL;
 303         acpi_handle handle;
 304         acpi_status status, wc_status = AE_ERROR;
 305         struct acpi_object_list input;
 306         union acpi_object wq_params[1];
 307         char method[5];
 308         char wc_method[5] = "WC";
 309
 310         if (!out)
 311                 return AE_BAD_PARAMETER;
 312
 313         block = &wblock->gblock;
 314         handle = wblock->acpi_device->handle;
 315
 316         if (block->instance_count <= instance)
 317                 return AE_BAD_PARAMETER;
 318
 319         /* Check GUID is a data block */
 320         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 321                 return AE_ERROR;
 322
 323         input.count = 1;
 324         input.pointer = wq_params;
 325         wq_params[0].type = ACPI_TYPE_INTEGER;
 326         wq_params[0].integer.value = instance;
 327
 328         if (instance == 0 && wblock->read_takes_no_args)
 329                 input.count = 0;
 330
 331         /*
 332          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
 333          * enable collection.
 334          */
 335         if (block->flags & ACPI_WMI_EXPENSIVE) {
 336                 strncat(wc_method, block->object_id, 2);
 337
 338                 /*
 339                  * Some GUIDs break the specification by declaring themselves
 340                  * expensive, but have no corresponding WCxx method. So we
 341                  * should not fail if this happens.
 342                  */
 343                 wc_status = acpi_execute_simple_method(handle, wc_method, 1);
 344         }
 345
 346         strcpy(method, "WQ");
 347         strncat(method, block->object_id, 2);
 348
 349         status = acpi_evaluate_object(handle, method, &input, out);
 350
 351         /*
 352          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
 353          * the WQxx method failed - we should disable collection anyway.
 354          */
 355         if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
 356                 status = acpi_execute_simple_method(handle, wc_method, 0);
 357         }
 358
 359         return status;
 360 }
 361
 362 /**
 363  * wmi_query_block - Return contents of a WMI block (deprecated)
 364  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 365  * @instance: Instance index
 366  * &out: Empty buffer to return the contents of the data block to
 367  *
 368  * Return the contents of an ACPI-WMI data block to a buffer
 369  */
 370 acpi_status wmi_query_block(const char *guid_string, u8 instance,
 371                             struct acpi_buffer *out)
 372 {
 373         struct wmi_block *wblock;
 374
 375         if (!guid_string)
 376                 return AE_BAD_PARAMETER;
 377
 378         if (!find_guid(guid_string, &wblock))
 379                 return AE_ERROR;
 380
 381         return __query_block(wblock, instance, out);
 382 }
 383 EXPORT_SYMBOL_GPL(wmi_query_block);
 384
 385 union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
 386 {
 387         struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
 388         struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
 389
 390         if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
 391                 return NULL;
 392
 393         return (union acpi_object *)out.pointer;
 394 }
 395 EXPORT_SYMBOL_GPL(wmidev_block_query);
 396
 397 /**
 398  * wmi_set_block - Write to a WMI block
 399  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 400  * @instance: Instance index
 401  * &in: Buffer containing new values for the data block
 402  *
 403  * Write the contents of the input buffer to an ACPI-WMI data block
 404  */
 405 acpi_status wmi_set_block(const char *guid_string, u8 instance,
 406                           const struct acpi_buffer *in)
 407 {
 408         struct guid_block *block = NULL;
 409         struct wmi_block *wblock = NULL;
 410         acpi_handle handle;
 411         struct acpi_object_list input;
 412         union acpi_object params[2];
 413         char method[5] = "WS";
 414
 415         if (!guid_string || !in)
 416                 return AE_BAD_DATA;
 417
 418         if (!find_guid(guid_string, &wblock))
 419                 return AE_ERROR;
 420
 421         block = &wblock->gblock;
 422         handle = wblock->acpi_device->handle;
 423
 424         if (block->instance_count <= instance)
 425                 return AE_BAD_PARAMETER;
 426
 427         /* Check GUID is a data block */
 428         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 429                 return AE_ERROR;
 430
 431         input.count = 2;
 432         input.pointer = params;
 433         params[0].type = ACPI_TYPE_INTEGER;
 434         params[0].integer.value = instance;
 435
 436         if (block->flags & ACPI_WMI_STRING) {
 437                 params[1].type = ACPI_TYPE_STRING;
 438         } else {
 439                 params[1].type = ACPI_TYPE_BUFFER;
 440         }
 441         params[1].buffer.length = in->length;
 442         params[1].buffer.pointer = in->pointer;
 443
 444         strncat(method, block->object_id, 2);
 445
 446         return acpi_evaluate_object(handle, method, &input, NULL);
 447 }
 448 EXPORT_SYMBOL_GPL(wmi_set_block);
 449
 450 static void wmi_dump_wdg(const struct guid_block *g)
 451 {
 452         pr_info("%pUL:\n", g->guid);
 453         if (g->flags & ACPI_WMI_EVENT)
 454                 pr_info("\tnotify_id: 0x%02X\n", g->notify_id);
 455         else
 456                 pr_info("\tobject_id: %2pE\n", g->object_id);
 457         pr_info("\tinstance_count: %d\n", g->instance_count);
 458         pr_info("\tflags: %#x", g->flags);
 459         if (g->flags) {
 460                 if (g->flags & ACPI_WMI_EXPENSIVE)
 461                         pr_cont(" ACPI_WMI_EXPENSIVE");
 462                 if (g->flags & ACPI_WMI_METHOD)
 463                         pr_cont(" ACPI_WMI_METHOD");
 464                 if (g->flags & ACPI_WMI_STRING)
 465                         pr_cont(" ACPI_WMI_STRING");
 466                 if (g->flags & ACPI_WMI_EVENT)
 467                         pr_cont(" ACPI_WMI_EVENT");
 468         }
 469         pr_cont("\n");
 470
 471 }
 472
 473 static void wmi_notify_debug(u32 value, void *context)
 474 {
 475         struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
 476         union acpi_object *obj;
 477         acpi_status status;
 478
 479         status = wmi_get_event_data(value, &response);
 480         if (status != AE_OK) {
 481                 pr_info("bad event status 0x%x\n", status);
 482                 return;
 483         }
 484
 485         obj = (union acpi_object *)response.pointer;
 486
 487         if (!obj)
 488                 return;
 489
 490         pr_info("DEBUG Event ");
 491         switch(obj->type) {
 492         case ACPI_TYPE_BUFFER:
 493                 pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
 494                 break;
 495         case ACPI_TYPE_STRING:
 496                 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
 497                 break;
 498         case ACPI_TYPE_INTEGER:
 499                 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
 500                 break;
 501         case ACPI_TYPE_PACKAGE:
 502                 pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
 503                 break;
 504         default:
 505                 pr_cont("object type 0x%X\n", obj->type);
 506         }
 507         kfree(obj);
 508 }
 509
 510 /**
 511  * wmi_install_notify_handler - Register handler for WMI events
 512  * @handler: Function to handle notifications
 513  * @data: Data to be returned to handler when event is fired
 514  *
 515  * Register a handler for events sent to the ACPI-WMI mapper device.
 516  */
 517 acpi_status wmi_install_notify_handler(const char *guid,
 518 wmi_notify_handler handler, void *data)
 519 {
 520         struct wmi_block *block;
 521         acpi_status status = AE_NOT_EXIST;
 522         uuid_le guid_input;
 523
 524         if (!guid || !handler)
 525                 return AE_BAD_PARAMETER;
 526
 527         if (uuid_le_to_bin(guid, &guid_input))
 528                 return AE_BAD_PARAMETER;
 529
 530         list_for_each_entry(block, &wmi_block_list, list) {
 531                 acpi_status wmi_status;
 532
 533                 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
 534                         if (block->handler &&
 535                             block->handler != wmi_notify_debug)
 536                                 return AE_ALREADY_ACQUIRED;
 537
 538                         block->handler = handler;
 539                         block->handler_data = data;
 540
 541                         wmi_status = wmi_method_enable(block, 1);
 542                         if ((wmi_status != AE_OK) ||
 543                             ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
 544                                 status = wmi_status;
 545                 }
 546         }
 547
 548         return status;
 549 }
 550 EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
 551
 552 /**
 553  * wmi_uninstall_notify_handler - Unregister handler for WMI events
 554  *
 555  * Unregister handler for events sent to the ACPI-WMI mapper device.
 556  */
 557 acpi_status wmi_remove_notify_handler(const char *guid)
 558 {
 559         struct wmi_block *block;
 560         acpi_status status = AE_NOT_EXIST;
 561         uuid_le guid_input;
 562
 563         if (!guid)
 564                 return AE_BAD_PARAMETER;
 565
 566         if (uuid_le_to_bin(guid, &guid_input))
 567                 return AE_BAD_PARAMETER;
 568
 569         list_for_each_entry(block, &wmi_block_list, list) {
 570                 acpi_status wmi_status;
 571
 572                 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
 573                         if (!block->handler ||
 574                             block->handler == wmi_notify_debug)
 575                                 return AE_NULL_ENTRY;
 576
 577                         if (debug_event) {
 578                                 block->handler = wmi_notify_debug;
 579                                 status = AE_OK;
 580                         } else {
 581                                 wmi_status = wmi_method_enable(block, 0);
 582                                 block->handler = NULL;
 583                                 block->handler_data = NULL;
 584                                 if ((wmi_status != AE_OK) ||
 585                                     ((wmi_status == AE_OK) &&
 586                                      (status == AE_NOT_EXIST)))
 587                                         status = wmi_status;
 588                         }
 589                 }
 590         }
 591
 592         return status;
 593 }
 594 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
 595
 596 /**
 597  * wmi_get_event_data - Get WMI data associated with an event
 598  *
 599  * @event: Event to find
 600  * @out: Buffer to hold event data. out->pointer should be freed with kfree()
 601  *
 602  * Returns extra data associated with an event in WMI.
 603  */
 604 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
 605 {
 606         struct acpi_object_list input;
 607         union acpi_object params[1];
 608         struct guid_block *gblock;
 609         struct wmi_block *wblock;
 610
 611         input.count = 1;
 612         input.pointer = params;
 613         params[0].type = ACPI_TYPE_INTEGER;
 614         params[0].integer.value = event;
 615
 616         list_for_each_entry(wblock, &wmi_block_list, list) {
 617                 gblock = &wblock->gblock;
 618
 619                 if ((gblock->flags & ACPI_WMI_EVENT) &&
 620                         (gblock->notify_id == event))
 621                         return acpi_evaluate_object(wblock->acpi_device->handle,
 622                                 "_WED", &input, out);
 623         }
 624
 625         return AE_NOT_FOUND;
 626 }
 627 EXPORT_SYMBOL_GPL(wmi_get_event_data);
 628
 629 /**
 630  * wmi_has_guid - Check if a GUID is available
 631  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 632  *
 633  * Check if a given GUID is defined by _WDG
 634  */
 635 bool wmi_has_guid(const char *guid_string)
 636 {
 637         return find_guid(guid_string, NULL);
 638 }
 639 EXPORT_SYMBOL_GPL(wmi_has_guid);
 640
 641 /**
 642  * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID
 643  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 644  *
 645  * Find the _UID of ACPI device associated with this WMI GUID.
 646  *
 647  * Return: The ACPI _UID field value or NULL if the WMI GUID was not found
 648  */
 649 char *wmi_get_acpi_device_uid(const char *guid_string)
 650 {
 651         struct wmi_block *wblock = NULL;
 652
 653         if (!find_guid(guid_string, &wblock))
 654                 return NULL;
 655
 656         return acpi_device_uid(wblock->acpi_device);
 657 }
 658 EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
 659
 660 static struct wmi_block *dev_to_wblock(struct device *dev)
 661 {
 662         return container_of(dev, struct wmi_block, dev.dev);
 663 }
 664
 665 static struct wmi_device *dev_to_wdev(struct device *dev)
 666 {
 667         return container_of(dev, struct wmi_device, dev);
 668 }
 669
 670 /*
 671  * sysfs interface
 672  */
 673 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 674                              char *buf)
 675 {
 676         struct wmi_block *wblock = dev_to_wblock(dev);
 677
 678         return sprintf(buf, "wmi:%pUL\n", wblock->gblock.guid);
 679 }
 680 static DEVICE_ATTR_RO(modalias);
 681
 682 static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
 683                          char *buf)
 684 {
 685         struct wmi_block *wblock = dev_to_wblock(dev);
 686
 687         return sprintf(buf, "%pUL\n", wblock->gblock.guid);
 688 }
 689 static DEVICE_ATTR_RO(guid);
 690
 691 static ssize_t instance_count_show(struct device *dev,
 692                                    struct device_attribute *attr, char *buf)
 693 {
 694         struct wmi_block *wblock = dev_to_wblock(dev);
 695
 696         return sprintf(buf, "%d\n", (int)wblock->gblock.instance_count);
 697 }
 698 static DEVICE_ATTR_RO(instance_count);
 699
 700 static ssize_t expensive_show(struct device *dev,
 701                               struct device_attribute *attr, char *buf)
 702 {
 703         struct wmi_block *wblock = dev_to_wblock(dev);
 704
 705         return sprintf(buf, "%d\n",
 706                        (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
 707 }
 708 static DEVICE_ATTR_RO(expensive);
 709
 710 static struct attribute *wmi_attrs[] = {
 711         &dev_attr_modalias.attr,
 712         &dev_attr_guid.attr,
 713         &dev_attr_instance_count.attr,
 714         &dev_attr_expensive.attr,
 715         NULL,
 716 };
 717 ATTRIBUTE_GROUPS(wmi);
 718
 719 static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
 720                               char *buf)
 721 {
 722         struct wmi_block *wblock = dev_to_wblock(dev);
 723
 724         return sprintf(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
 725 }
 726 static DEVICE_ATTR_RO(notify_id);
 727
 728 static struct attribute *wmi_event_attrs[] = {
 729         &dev_attr_notify_id.attr,
 730         NULL,
 731 };
 732 ATTRIBUTE_GROUPS(wmi_event);
 733
 734 static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
 735                               char *buf)
 736 {
 737         struct wmi_block *wblock = dev_to_wblock(dev);
 738
 739         return sprintf(buf, "%c%c\n", wblock->gblock.object_id[0],
 740                        wblock->gblock.object_id[1]);
 741 }
 742 static DEVICE_ATTR_RO(object_id);
 743
 744 static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
 745                             char *buf)
 746 {
 747         struct wmi_device *wdev = dev_to_wdev(dev);
 748
 749         return sprintf(buf, "%d\n", (int)wdev->setable);
 750 }
 751 static DEVICE_ATTR_RO(setable);
 752
 753 static struct attribute *wmi_data_attrs[] = {
 754         &dev_attr_object_id.attr,
 755         &dev_attr_setable.attr,
 756         NULL,
 757 };
 758 ATTRIBUTE_GROUPS(wmi_data);
 759
 760 static struct attribute *wmi_method_attrs[] = {
 761         &dev_attr_object_id.attr,
 762         NULL,
 763 };
 764 ATTRIBUTE_GROUPS(wmi_method);
 765
 766 static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 767 {
 768         struct wmi_block *wblock = dev_to_wblock(dev);
 769
 770         if (add_uevent_var(env, "MODALIAS=wmi:%pUL", wblock->gblock.guid))
 771                 return -ENOMEM;
 772
 773         if (add_uevent_var(env, "WMI_GUID=%pUL", wblock->gblock.guid))
 774                 return -ENOMEM;
 775
 776         return 0;
 777 }
 778
 779 static void wmi_dev_release(struct device *dev)
 780 {
 781         struct wmi_block *wblock = dev_to_wblock(dev);
 782
 783         kfree(wblock);
 784 }
 785
 786 static int wmi_dev_match(struct device *dev, struct device_driver *driver)
 787 {
 788         struct wmi_driver *wmi_driver =
 789                 container_of(driver, struct wmi_driver, driver);
 790         struct wmi_block *wblock = dev_to_wblock(dev);
 791         const struct wmi_device_id *id = wmi_driver->id_table;
 792
 793         if (id == NULL)
 794                 return 0;
 795
 796         while (*id->guid_string) {
 797                 uuid_le driver_guid;
 798
 799                 if (WARN_ON(uuid_le_to_bin(id->guid_string, &driver_guid)))
 800                         continue;
 801                 if (!memcmp(&driver_guid, wblock->gblock.guid, 16))
 802                         return 1;
 803
 804                 id++;
 805         }
 806
 807         return 0;
 808 }
 809 static int wmi_char_open(struct inode *inode, struct file *filp)
 810 {
 811         const char *driver_name = filp->f_path.dentry->d_iname;
 812         struct wmi_block *wblock = NULL;
 813         struct wmi_block *next = NULL;
 814
 815         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
 816                 if (!wblock->dev.dev.driver)
 817                         continue;
 818                 if (strcmp(driver_name, wblock->dev.dev.driver->name) == 0) {
 819                         filp->private_data = wblock;
 820                         break;
 821                 }
 822         }
 823
 824         if (!filp->private_data)
 825                 return -ENODEV;
 826
 827         return nonseekable_open(inode, filp);
 828 }
 829
 830 static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
 831         size_t length, loff_t *offset)
 832 {
 833         struct wmi_block *wblock = filp->private_data;
 834
 835         return simple_read_from_buffer(buffer, length, offset,
 836                                        &wblock->req_buf_size,
 837                                        sizeof(wblock->req_buf_size));
 838 }
 839
 840 static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 841 {
 842         struct wmi_ioctl_buffer __user *input =
 843                 (struct wmi_ioctl_buffer __user *) arg;
 844         struct wmi_block *wblock = filp->private_data;
 845         struct wmi_ioctl_buffer *buf = NULL;
 846         struct wmi_driver *wdriver = NULL;
 847         int ret;
 848
 849         if (_IOC_TYPE(cmd) != WMI_IOC)
 850                 return -ENOTTY;
 851
 852         /* make sure we're not calling a higher instance than exists*/
 853         if (_IOC_NR(cmd) >= wblock->gblock.instance_count)
 854                 return -EINVAL;
 855
 856         mutex_lock(&wblock->char_mutex);
 857         buf = wblock->handler_data;
 858         if (get_user(buf->length, &input->length)) {
 859                 dev_dbg(&wblock->dev.dev, "Read length from user failed\n");
 860                 ret = -EFAULT;
 861                 goto out_ioctl;
 862         }
 863         /* if it's too small, abort */
 864         if (buf->length < wblock->req_buf_size) {
 865                 dev_err(&wblock->dev.dev,
 866                         "Buffer %lld too small, need at least %lld\n",
 867                         buf->length, wblock->req_buf_size);
 868                 ret = -EINVAL;
 869                 goto out_ioctl;
 870         }
 871         /* if it's too big, warn, driver will only use what is needed */
 872         if (buf->length > wblock->req_buf_size)
 873                 dev_warn(&wblock->dev.dev,
 874                         "Buffer %lld is bigger than required %lld\n",
 875                         buf->length, wblock->req_buf_size);
 876
 877         /* copy the structure from userspace */
 878         if (copy_from_user(buf, input, wblock->req_buf_size)) {
 879                 dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n",
 880                         wblock->req_buf_size);
 881                 ret = -EFAULT;
 882                 goto out_ioctl;
 883         }
 884
 885         /* let the driver do any filtering and do the call */
 886         wdriver = container_of(wblock->dev.dev.driver,
 887                                struct wmi_driver, driver);
 888         if (!try_module_get(wdriver->driver.owner)) {
 889                 ret = -EBUSY;
 890                 goto out_ioctl;
 891         }
 892         ret = wdriver->filter_callback(&wblock->dev, cmd, buf);
 893         module_put(wdriver->driver.owner);
 894         if (ret)
 895                 goto out_ioctl;
 896
 897         /* return the result (only up to our internal buffer size) */
 898         if (copy_to_user(input, buf, wblock->req_buf_size)) {
 899                 dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n",
 900                         wblock->req_buf_size);
 901                 ret = -EFAULT;
 902         }
 903
 904 out_ioctl:
 905         mutex_unlock(&wblock->char_mutex);
 906         return ret;
 907 }
 908
 909 static const struct file_operations wmi_fops = {
 910         .owner          = THIS_MODULE,
 911         .read           = wmi_char_read,
 912         .open           = wmi_char_open,
 913         .unlocked_ioctl = wmi_ioctl,
 914         .compat_ioctl   = compat_ptr_ioctl,
 915 };
 916
 917 static int wmi_dev_probe(struct device *dev)
 918 {
 919         struct wmi_block *wblock = dev_to_wblock(dev);
 920         struct wmi_driver *wdriver =
 921                 container_of(dev->driver, struct wmi_driver, driver);
 922         int ret = 0;
 923         char *buf;
 924
 925         if (ACPI_FAILURE(wmi_method_enable(wblock, 1)))
 926                 dev_warn(dev, "failed to enable device -- probing anyway\n");
 927
 928         if (wdriver->probe) {
 929                 ret = wdriver->probe(dev_to_wdev(dev),
 930                                 find_guid_context(wblock, wdriver));
 931                 if (ret != 0)
 932                         goto probe_failure;
 933         }
 934
 935         /* driver wants a character device made */
 936         if (wdriver->filter_callback) {
 937                 /* check that required buffer size declared by driver or MOF */
 938                 if (!wblock->req_buf_size) {
 939                         dev_err(&wblock->dev.dev,
 940                                 "Required buffer size not set\n");
 941                         ret = -EINVAL;
 942                         goto probe_failure;
 943                 }
 944
 945                 wblock->handler_data = kmalloc(wblock->req_buf_size,
 946                                                GFP_KERNEL);
 947                 if (!wblock->handler_data) {
 948                         ret = -ENOMEM;
 949                         goto probe_failure;
 950                 }
 951
 952                 buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name);
 953                 if (!buf) {
 954                         ret = -ENOMEM;
 955                         goto probe_string_failure;
 956                 }
 957                 wblock->char_dev.minor = MISC_DYNAMIC_MINOR;
 958                 wblock->char_dev.name = buf;
 959                 wblock->char_dev.fops = &wmi_fops;
 960                 wblock->char_dev.mode = 0444;
 961                 ret = misc_register(&wblock->char_dev);
 962                 if (ret) {
 963                         dev_warn(dev, "failed to register char dev: %d\n", ret);
 964                         ret = -ENOMEM;
 965                         goto probe_misc_failure;
 966                 }
 967         }
 968
 969         return 0;
 970
 971 probe_misc_failure:
 972         kfree(buf);
 973 probe_string_failure:
 974         kfree(wblock->handler_data);
 975 probe_failure:
 976         if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
 977                 dev_warn(dev, "failed to disable device\n");
 978         return ret;
 979 }
 980
 981 static int wmi_dev_remove(struct device *dev)
 982 {
 983         struct wmi_block *wblock = dev_to_wblock(dev);
 984         struct wmi_driver *wdriver =
 985                 container_of(dev->driver, struct wmi_driver, driver);
 986         int ret = 0;
 987
 988         if (wdriver->filter_callback) {
 989                 misc_deregister(&wblock->char_dev);
 990                 kfree(wblock->char_dev.name);
 991                 kfree(wblock->handler_data);
 992         }
 993
 994         if (wdriver->remove)
 995                 ret = wdriver->remove(dev_to_wdev(dev));
 996
 997         if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
 998                 dev_warn(dev, "failed to disable device\n");
 999
1000         return ret;
1001 }
1002
1003 static struct class wmi_bus_class = {
1004         .name = "wmi_bus",
1005 };
1006
1007 static struct bus_type wmi_bus_type = {
1008         .name = "wmi",
1009         .dev_groups = wmi_groups,
1010         .match = wmi_dev_match,
1011         .uevent = wmi_dev_uevent,
1012         .probe = wmi_dev_probe,
1013         .remove = wmi_dev_remove,
1014 };
1015
1016 static const struct device_type wmi_type_event = {
1017         .name = "event",
1018         .groups = wmi_event_groups,
1019         .release = wmi_dev_release,
1020 };
1021
1022 static const struct device_type wmi_type_method = {
1023         .name = "method",
1024         .groups = wmi_method_groups,
1025         .release = wmi_dev_release,
1026 };
1027
1028 static const struct device_type wmi_type_data = {
1029         .name = "data",
1030         .groups = wmi_data_groups,
1031         .release = wmi_dev_release,
1032 };
1033
1034 static int wmi_create_device(struct device *wmi_bus_dev,
1035                              const struct guid_block *gblock,
1036                              struct wmi_block *wblock,
1037                              struct acpi_device *device)
1038 {
1039         struct acpi_device_info *info;
1040         char method[5];
1041         int result;
1042
1043         if (gblock->flags & ACPI_WMI_EVENT) {
1044                 wblock->dev.dev.type = &wmi_type_event;
1045                 goto out_init;
1046         }
1047
1048         if (gblock->flags & ACPI_WMI_METHOD) {
1049                 wblock->dev.dev.type = &wmi_type_method;
1050                 mutex_init(&wblock->char_mutex);
1051                 goto out_init;
1052         }
1053
1054         /*
1055          * Data Block Query Control Method (WQxx by convention) is
1056          * required per the WMI documentation. If it is not present,
1057          * we ignore this data block.
1058          */
1059         strcpy(method, "WQ");
1060         strncat(method, wblock->gblock.object_id, 2);
1061         result = get_subobj_info(device->handle, method, &info);
1062
1063         if (result) {
1064                 dev_warn(wmi_bus_dev,
1065                          "%s data block query control method not found\n",
1066                          method);
1067                 return result;
1068         }
1069
1070         wblock->dev.dev.type = &wmi_type_data;
1071
1072         /*
1073          * The Microsoft documentation specifically states:
1074          *
1075          *   Data blocks registered with only a single instance
1076          *   can ignore the parameter.
1077          *
1078          * ACPICA will get mad at us if we call the method with the wrong number
1079          * of arguments, so check what our method expects.  (On some Dell
1080          * laptops, WQxx may not be a method at all.)
1081          */
1082         if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1083                 wblock->read_takes_no_args = true;
1084
1085         kfree(info);
1086
1087         strcpy(method, "WS");
1088         strncat(method, wblock->gblock.object_id, 2);
1089         result = get_subobj_info(device->handle, method, NULL);
1090
1091         if (result == 0)
1092                 wblock->dev.setable = true;
1093
1094  out_init:
1095         wblock->dev.dev.bus = &wmi_bus_type;
1096         wblock->dev.dev.parent = wmi_bus_dev;
1097
1098         dev_set_name(&wblock->dev.dev, "%pUL", gblock->guid);
1099
1100         device_initialize(&wblock->dev.dev);
1101
1102         return 0;
1103 }
1104
1105 static void wmi_free_devices(struct acpi_device *device)
1106 {
1107         struct wmi_block *wblock, *next;
1108
1109         /* Delete devices for all the GUIDs */
1110         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1111                 if (wblock->acpi_device == device) {
1112                         list_del(&wblock->list);
1113                         device_unregister(&wblock->dev.dev);
1114                 }
1115         }
1116 }
1117
1118 static bool guid_already_parsed(struct acpi_device *device,
1119                                 const u8 *guid)
1120 {
1121         struct wmi_block *wblock;
1122
1123         list_for_each_entry(wblock, &wmi_block_list, list) {
1124                 if (memcmp(wblock->gblock.guid, guid, 16) == 0) {
1125                         /*
1126                          * Because we historically didn't track the relationship
1127                          * between GUIDs and ACPI nodes, we don't know whether
1128                          * we need to suppress GUIDs that are unique on a
1129                          * given node but duplicated across nodes.
1130                          */
1131                         dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
1132                                  guid, dev_name(&wblock->acpi_device->dev));
1133                         return true;
1134                 }
1135         }
1136
1137         return false;
1138 }
1139
1140 /*
1141  * Parse the _WDG method for the GUID data blocks
1142  */
1143 static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
1144 {
1145         struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1146         const struct guid_block *gblock;
1147         struct wmi_block *wblock, *next;
1148         union acpi_object *obj;
1149         acpi_status status;
1150         int retval = 0;
1151         u32 i, total;
1152
1153         status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1154         if (ACPI_FAILURE(status))
1155                 return -ENXIO;
1156
1157         obj = (union acpi_object *) out.pointer;
1158         if (!obj)
1159                 return -ENXIO;
1160
1161         if (obj->type != ACPI_TYPE_BUFFER) {
1162                 retval = -ENXIO;
1163                 goto out_free_pointer;
1164         }
1165
1166         gblock = (const struct guid_block *)obj->buffer.pointer;
1167         total = obj->buffer.length / sizeof(struct guid_block);
1168
1169         for (i = 0; i < total; i++) {
1170                 if (debug_dump_wdg)
1171                         wmi_dump_wdg(&gblock[i]);
1172
1173                 /*
1174                  * Some WMI devices, like those for nVidia hooks, have a
1175                  * duplicate GUID. It's not clear what we should do in this
1176                  * case yet, so for now, we'll just ignore the duplicate
1177                  * for device creation.
1178                  */
1179                 if (guid_already_parsed(device, gblock[i].guid))
1180                         continue;
1181
1182                 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
1183                 if (!wblock) {
1184                         retval = -ENOMEM;
1185                         break;
1186                 }
1187
1188                 wblock->acpi_device = device;
1189                 wblock->gblock = gblock[i];
1190
1191                 retval = wmi_create_device(wmi_bus_dev, &gblock[i], wblock, device);
1192                 if (retval) {
1193                         kfree(wblock);
1194                         continue;
1195                 }
1196
1197                 list_add_tail(&wblock->list, &wmi_block_list);
1198
1199                 if (debug_event) {
1200                         wblock->handler = wmi_notify_debug;
1201                         wmi_method_enable(wblock, 1);
1202                 }
1203         }
1204
1205         /*
1206          * Now that all of the devices are created, add them to the
1207          * device tree and probe subdrivers.
1208          */
1209         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1210                 if (wblock->acpi_device != device)
1211                         continue;
1212
1213                 retval = device_add(&wblock->dev.dev);
1214                 if (retval) {
1215                         dev_err(wmi_bus_dev, "failed to register %pUL\n",
1216                                 wblock->gblock.guid);
1217                         if (debug_event)
1218                                 wmi_method_enable(wblock, 0);
1219                         list_del(&wblock->list);
1220                         put_device(&wblock->dev.dev);
1221                 }
1222         }
1223
1224 out_free_pointer:
1225         kfree(out.pointer);
1226         return retval;
1227 }
1228
1229 /*
1230  * WMI can have EmbeddedControl access regions. In which case, we just want to
1231  * hand these off to the EC driver.
1232  */
1233 static acpi_status
1234 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1235                       u32 bits, u64 *value,
1236                       void *handler_context, void *region_context)
1237 {
1238         int result = 0, i = 0;
1239         u8 temp = 0;
1240
1241         if ((address > 0xFF) || !value)
1242                 return AE_BAD_PARAMETER;
1243
1244         if (function != ACPI_READ && function != ACPI_WRITE)
1245                 return AE_BAD_PARAMETER;
1246
1247         if (bits != 8)
1248                 return AE_BAD_PARAMETER;
1249
1250         if (function == ACPI_READ) {
1251                 result = ec_read(address, &temp);
1252                 (*value) |= ((u64)temp) << i;
1253         } else {
1254                 temp = 0xff & ((*value) >> i);
1255                 result = ec_write(address, temp);
1256         }
1257
1258         switch (result) {
1259         case -EINVAL:
1260                 return AE_BAD_PARAMETER;
1261                 break;
1262         case -ENODEV:
1263                 return AE_NOT_FOUND;
1264                 break;
1265         case -ETIME:
1266                 return AE_TIME;
1267                 break;
1268         default:
1269                 return AE_OK;
1270         }
1271 }
1272
1273 static void acpi_wmi_notify_handler(acpi_handle handle, u32 event,
1274                                     void *context)
1275 {
1276         struct guid_block *block;
1277         struct wmi_block *wblock;
1278         bool found_it = false;
1279
1280         list_for_each_entry(wblock, &wmi_block_list, list) {
1281                 block = &wblock->gblock;
1282
1283                 if (wblock->acpi_device->handle == handle &&
1284                     (block->flags & ACPI_WMI_EVENT) &&
1285                     (block->notify_id == event))
1286                 {
1287                         found_it = true;
1288                         break;
1289                 }
1290         }
1291
1292         if (!found_it)
1293                 return;
1294
1295         /* If a driver is bound, then notify the driver. */
1296         if (wblock->dev.dev.driver) {
1297                 struct wmi_driver *driver;
1298                 struct acpi_object_list input;
1299                 union acpi_object params[1];
1300                 struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL };
1301                 acpi_status status;
1302
1303                 driver = container_of(wblock->dev.dev.driver,
1304                                       struct wmi_driver, driver);
1305
1306                 input.count = 1;
1307                 input.pointer = params;
1308                 params[0].type = ACPI_TYPE_INTEGER;
1309                 params[0].integer.value = event;
1310
1311                 status = acpi_evaluate_object(wblock->acpi_device->handle,
1312                                               "_WED", &input, &evdata);
1313                 if (ACPI_FAILURE(status)) {
1314                         dev_warn(&wblock->dev.dev,
1315                                  "failed to get event data\n");
1316                         return;
1317                 }
1318
1319                 if (driver->notify)
1320                         driver->notify(&wblock->dev,
1321                                        (union acpi_object *)evdata.pointer);
1322
1323                 kfree(evdata.pointer);
1324         } else if (wblock->handler) {
1325                 /* Legacy handler */
1326                 wblock->handler(event, wblock->handler_data);
1327         }
1328
1329         if (debug_event) {
1330                 pr_info("DEBUG Event GUID: %pUL\n",
1331                         wblock->gblock.guid);
1332         }
1333
1334         acpi_bus_generate_netlink_event(
1335                 wblock->acpi_device->pnp.device_class,
1336                 dev_name(&wblock->dev.dev),
1337                 event, 0);
1338
1339 }
1340
1341 static int acpi_wmi_remove(struct platform_device *device)
1342 {
1343         struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev);
1344
1345         acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1346                                    acpi_wmi_notify_handler);
1347         acpi_remove_address_space_handler(acpi_device->handle,
1348                                 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
1349         wmi_free_devices(acpi_device);
1350         device_destroy(&wmi_bus_class, MKDEV(0, 0));
1351
1352         return 0;
1353 }
1354
1355 static int acpi_wmi_probe(struct platform_device *device)
1356 {
1357         struct acpi_device *acpi_device;
1358         struct device *wmi_bus_dev;
1359         acpi_status status;
1360         int error;
1361
1362         acpi_device = ACPI_COMPANION(&device->dev);
1363         if (!acpi_device) {
1364                 dev_err(&device->dev, "ACPI companion is missing\n");
1365                 return -ENODEV;
1366         }
1367
1368         status = acpi_install_address_space_handler(acpi_device->handle,
1369                                                     ACPI_ADR_SPACE_EC,
1370                                                     &acpi_wmi_ec_space_handler,
1371                                                     NULL, NULL);
1372         if (ACPI_FAILURE(status)) {
1373                 dev_err(&device->dev, "Error installing EC region handler\n");
1374                 return -ENODEV;
1375         }
1376
1377         status = acpi_install_notify_handler(acpi_device->handle,
1378                                              ACPI_DEVICE_NOTIFY,
1379                                              acpi_wmi_notify_handler,
1380                                              NULL);
1381         if (ACPI_FAILURE(status)) {
1382                 dev_err(&device->dev, "Error installing notify handler\n");
1383                 error = -ENODEV;
1384                 goto err_remove_ec_handler;
1385         }
1386
1387         wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0),
1388                                     NULL, "wmi_bus-%s", dev_name(&device->dev));
1389         if (IS_ERR(wmi_bus_dev)) {
1390                 error = PTR_ERR(wmi_bus_dev);
1391                 goto err_remove_notify_handler;
1392         }
1393         dev_set_drvdata(&device->dev, wmi_bus_dev);
1394
1395         error = parse_wdg(wmi_bus_dev, acpi_device);
1396         if (error) {
1397                 pr_err("Failed to parse WDG method\n");
1398                 goto err_remove_busdev;
1399         }
1400
1401         return 0;
1402
1403 err_remove_busdev:
1404         device_destroy(&wmi_bus_class, MKDEV(0, 0));
1405
1406 err_remove_notify_handler:
1407         acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1408                                    acpi_wmi_notify_handler);
1409
1410 err_remove_ec_handler:
1411         acpi_remove_address_space_handler(acpi_device->handle,
1412                                           ACPI_ADR_SPACE_EC,
1413                                           &acpi_wmi_ec_space_handler);
1414
1415         return error;
1416 }
1417
1418 int __must_check __wmi_driver_register(struct wmi_driver *driver,
1419                                        struct module *owner)
1420 {
1421         driver->driver.owner = owner;
1422         driver->driver.bus = &wmi_bus_type;
1423
1424         return driver_register(&driver->driver);
1425 }
1426 EXPORT_SYMBOL(__wmi_driver_register);
1427
1428 void wmi_driver_unregister(struct wmi_driver *driver)
1429 {
1430         driver_unregister(&driver->driver);
1431 }
1432 EXPORT_SYMBOL(wmi_driver_unregister);
1433
1434 static int __init acpi_wmi_init(void)
1435 {
1436         int error;
1437
1438         if (acpi_disabled)
1439                 return -ENODEV;
1440
1441         error = class_register(&wmi_bus_class);
1442         if (error)
1443                 return error;
1444
1445         error = bus_register(&wmi_bus_type);
1446         if (error)
1447                 goto err_unreg_class;
1448
1449         error = platform_driver_register(&acpi_wmi_driver);
1450         if (error) {
1451                 pr_err("Error loading mapper\n");
1452                 goto err_unreg_bus;
1453         }
1454
1455         return 0;
1456
1457 err_unreg_bus:
1458         bus_unregister(&wmi_bus_type);
1459
1460 err_unreg_class:
1461         class_unregister(&wmi_bus_class);
1462
1463         return error;
1464 }
1465
1466 static void __exit acpi_wmi_exit(void)
1467 {
1468         platform_driver_unregister(&acpi_wmi_driver);
1469         bus_unregister(&wmi_bus_type);
1470         class_unregister(&wmi_bus_class);
1471 }
1472
1473 subsys_initcall_sync(acpi_wmi_init);
1474 module_exit(acpi_wmi_exit);