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