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 <[email protected]>
   6  *
   7  *  GUID parsing code from ldm.c is:
   8  *   Copyright (C) 2001,2002 Richard Russon <[email protected]>
   9  *   Copyright (c) 2001-2007 Anton Altaparmakov
  10  *   Copyright (C) 2001,2002 Jakob Kemi <[email protected]>
  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                 if (acpi_has_method(handle, wc_method))
 344                         wc_status = acpi_execute_simple_method(handle,
 345                                                                 wc_method, 1);
 346         }
 347
 348         strcpy(method, "WQ");
 349         strncat(method, block->object_id, 2);
 350
 351         status = acpi_evaluate_object(handle, method, &input, out);
 352
 353         /*
 354          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
 355          * the WQxx method failed - we should disable collection anyway.
 356          */
 357         if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
 358                 status = acpi_execute_simple_method(handle, wc_method, 0);
 359         }
 360
 361         return status;
 362 }
 363
 364 /**
 365  * wmi_query_block - Return contents of a WMI block (deprecated)
 366  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 367  * @instance: Instance index
 368  * &out: Empty buffer to return the contents of the data block to
 369  *
 370  * Return the contents of an ACPI-WMI data block to a buffer
 371  */
 372 acpi_status wmi_query_block(const char *guid_string, u8 instance,
 373                             struct acpi_buffer *out)
 374 {
 375         struct wmi_block *wblock;
 376
 377         if (!guid_string)
 378                 return AE_BAD_PARAMETER;
 379
 380         if (!find_guid(guid_string, &wblock))
 381                 return AE_ERROR;
 382
 383         return __query_block(wblock, instance, out);
 384 }
 385 EXPORT_SYMBOL_GPL(wmi_query_block);
 386
 387 union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
 388 {
 389         struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
 390         struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
 391
 392         if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
 393                 return NULL;
 394
 395         return (union acpi_object *)out.pointer;
 396 }
 397 EXPORT_SYMBOL_GPL(wmidev_block_query);
 398
 399 /**
 400  * wmi_set_block - Write to a WMI block
 401  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 402  * @instance: Instance index
 403  * &in: Buffer containing new values for the data block
 404  *
 405  * Write the contents of the input buffer to an ACPI-WMI data block
 406  */
 407 acpi_status wmi_set_block(const char *guid_string, u8 instance,
 408                           const struct acpi_buffer *in)
 409 {
 410         struct guid_block *block = NULL;
 411         struct wmi_block *wblock = NULL;
 412         acpi_handle handle;
 413         struct acpi_object_list input;
 414         union acpi_object params[2];
 415         char method[5] = "WS";
 416
 417         if (!guid_string || !in)
 418                 return AE_BAD_DATA;
 419
 420         if (!find_guid(guid_string, &wblock))
 421                 return AE_ERROR;
 422
 423         block = &wblock->gblock;
 424         handle = wblock->acpi_device->handle;
 425
 426         if (block->instance_count <= instance)
 427                 return AE_BAD_PARAMETER;
 428
 429         /* Check GUID is a data block */
 430         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 431                 return AE_ERROR;
 432
 433         input.count = 2;
 434         input.pointer = params;
 435         params[0].type = ACPI_TYPE_INTEGER;
 436         params[0].integer.value = instance;
 437
 438         if (block->flags & ACPI_WMI_STRING) {
 439                 params[1].type = ACPI_TYPE_STRING;
 440         } else {
 441                 params[1].type = ACPI_TYPE_BUFFER;
 442         }
 443         params[1].buffer.length = in->length;
 444         params[1].buffer.pointer = in->pointer;
 445
 446         strncat(method, block->object_id, 2);
 447
 448         return acpi_evaluate_object(handle, method, &input, NULL);
 449 }
 450 EXPORT_SYMBOL_GPL(wmi_set_block);
 451
 452 static void wmi_dump_wdg(const struct guid_block *g)
 453 {
 454         pr_info("%pUL:\n", g->guid);
 455         if (g->flags & ACPI_WMI_EVENT)
 456                 pr_info("\tnotify_id: 0x%02X\n", g->notify_id);
 457         else
 458                 pr_info("\tobject_id: %2pE\n", g->object_id);
 459         pr_info("\tinstance_count: %d\n", g->instance_count);
 460         pr_info("\tflags: %#x", g->flags);
 461         if (g->flags) {
 462                 if (g->flags & ACPI_WMI_EXPENSIVE)
 463                         pr_cont(" ACPI_WMI_EXPENSIVE");
 464                 if (g->flags & ACPI_WMI_METHOD)
 465                         pr_cont(" ACPI_WMI_METHOD");
 466                 if (g->flags & ACPI_WMI_STRING)
 467                         pr_cont(" ACPI_WMI_STRING");
 468                 if (g->flags & ACPI_WMI_EVENT)
 469                         pr_cont(" ACPI_WMI_EVENT");
 470         }
 471         pr_cont("\n");
 472
 473 }
 474
 475 static void wmi_notify_debug(u32 value, void *context)
 476 {
 477         struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
 478         union acpi_object *obj;
 479         acpi_status status;
 480
 481         status = wmi_get_event_data(value, &response);
 482         if (status != AE_OK) {
 483                 pr_info("bad event status 0x%x\n", status);
 484                 return;
 485         }
 486
 487         obj = (union acpi_object *)response.pointer;
 488
 489         if (!obj)
 490                 return;
 491
 492         pr_info("DEBUG Event ");
 493         switch(obj->type) {
 494         case ACPI_TYPE_BUFFER:
 495                 pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
 496                 break;
 497         case ACPI_TYPE_STRING:
 498                 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
 499                 break;
 500         case ACPI_TYPE_INTEGER:
 501                 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
 502                 break;
 503         case ACPI_TYPE_PACKAGE:
 504                 pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
 505                 break;
 506         default:
 507                 pr_cont("object type 0x%X\n", obj->type);
 508         }
 509         kfree(obj);
 510 }
 511
 512 /**
 513  * wmi_install_notify_handler - Register handler for WMI events
 514  * @handler: Function to handle notifications
 515  * @data: Data to be returned to handler when event is fired
 516  *
 517  * Register a handler for events sent to the ACPI-WMI mapper device.
 518  */
 519 acpi_status wmi_install_notify_handler(const char *guid,
 520 wmi_notify_handler handler, void *data)
 521 {
 522         struct wmi_block *block;
 523         acpi_status status = AE_NOT_EXIST;
 524         uuid_le guid_input;
 525
 526         if (!guid || !handler)
 527                 return AE_BAD_PARAMETER;
 528
 529         if (uuid_le_to_bin(guid, &guid_input))
 530                 return AE_BAD_PARAMETER;
 531
 532         list_for_each_entry(block, &wmi_block_list, list) {
 533                 acpi_status wmi_status;
 534
 535                 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
 536                         if (block->handler &&
 537                             block->handler != wmi_notify_debug)
 538                                 return AE_ALREADY_ACQUIRED;
 539
 540                         block->handler = handler;
 541                         block->handler_data = data;
 542
 543                         wmi_status = wmi_method_enable(block, 1);
 544                         if ((wmi_status != AE_OK) ||
 545                             ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
 546                                 status = wmi_status;
 547                 }
 548         }
 549
 550         return status;
 551 }
 552 EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
 553
 554 /**
 555  * wmi_uninstall_notify_handler - Unregister handler for WMI events
 556  *
 557  * Unregister handler for events sent to the ACPI-WMI mapper device.
 558  */
 559 acpi_status wmi_remove_notify_handler(const char *guid)
 560 {
 561         struct wmi_block *block;
 562         acpi_status status = AE_NOT_EXIST;
 563         uuid_le guid_input;
 564
 565         if (!guid)
 566                 return AE_BAD_PARAMETER;
 567
 568         if (uuid_le_to_bin(guid, &guid_input))
 569                 return AE_BAD_PARAMETER;
 570
 571         list_for_each_entry(block, &wmi_block_list, list) {
 572                 acpi_status wmi_status;
 573
 574                 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
 575                         if (!block->handler ||
 576                             block->handler == wmi_notify_debug)
 577                                 return AE_NULL_ENTRY;
 578
 579                         if (debug_event) {
 580                                 block->handler = wmi_notify_debug;
 581                                 status = AE_OK;
 582                         } else {
 583                                 wmi_status = wmi_method_enable(block, 0);
 584                                 block->handler = NULL;
 585                                 block->handler_data = NULL;
 586                                 if ((wmi_status != AE_OK) ||
 587                                     ((wmi_status == AE_OK) &&
 588                                      (status == AE_NOT_EXIST)))
 589                                         status = wmi_status;
 590                         }
 591                 }
 592         }
 593
 594         return status;
 595 }
 596 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
 597
 598 /**
 599  * wmi_get_event_data - Get WMI data associated with an event
 600  *
 601  * @event: Event to find
 602  * @out: Buffer to hold event data. out->pointer should be freed with kfree()
 603  *
 604  * Returns extra data associated with an event in WMI.
 605  */
 606 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
 607 {
 608         struct acpi_object_list input;
 609         union acpi_object params[1];
 610         struct guid_block *gblock;
 611         struct wmi_block *wblock;
 612
 613         input.count = 1;
 614         input.pointer = params;
 615         params[0].type = ACPI_TYPE_INTEGER;
 616         params[0].integer.value = event;
 617
 618         list_for_each_entry(wblock, &wmi_block_list, list) {
 619                 gblock = &wblock->gblock;
 620
 621                 if ((gblock->flags & ACPI_WMI_EVENT) &&
 622                         (gblock->notify_id == event))
 623                         return acpi_evaluate_object(wblock->acpi_device->handle,
 624                                 "_WED", &input, out);
 625         }
 626
 627         return AE_NOT_FOUND;
 628 }
 629 EXPORT_SYMBOL_GPL(wmi_get_event_data);
 630
 631 /**
 632  * wmi_has_guid - Check if a GUID is available
 633  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 634  *
 635  * Check if a given GUID is defined by _WDG
 636  */
 637 bool wmi_has_guid(const char *guid_string)
 638 {
 639         return find_guid(guid_string, NULL);
 640 }
 641 EXPORT_SYMBOL_GPL(wmi_has_guid);
 642
 643 /**
 644  * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID
 645  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 646  *
 647  * Find the _UID of ACPI device associated with this WMI GUID.
 648  *
 649  * Return: The ACPI _UID field value or NULL if the WMI GUID was not found
 650  */
 651 char *wmi_get_acpi_device_uid(const char *guid_string)
 652 {
 653         struct wmi_block *wblock = NULL;
 654
 655         if (!find_guid(guid_string, &wblock))
 656                 return NULL;
 657
 658         return acpi_device_uid(wblock->acpi_device);
 659 }
 660 EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
 661
 662 static struct wmi_block *dev_to_wblock(struct device *dev)
 663 {
 664         return container_of(dev, struct wmi_block, dev.dev);
 665 }
 666
 667 static struct wmi_device *dev_to_wdev(struct device *dev)
 668 {
 669         return container_of(dev, struct wmi_device, dev);
 670 }
 671
 672 /*
 673  * sysfs interface
 674  */
 675 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 676                              char *buf)
 677 {
 678         struct wmi_block *wblock = dev_to_wblock(dev);
 679
 680         return sprintf(buf, "wmi:%pUL\n", wblock->gblock.guid);
 681 }
 682 static DEVICE_ATTR_RO(modalias);
 683
 684 static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
 685                          char *buf)
 686 {
 687         struct wmi_block *wblock = dev_to_wblock(dev);
 688
 689         return sprintf(buf, "%pUL\n", wblock->gblock.guid);
 690 }
 691 static DEVICE_ATTR_RO(guid);
 692
 693 static ssize_t instance_count_show(struct device *dev,
 694                                    struct device_attribute *attr, char *buf)
 695 {
 696         struct wmi_block *wblock = dev_to_wblock(dev);
 697
 698         return sprintf(buf, "%d\n", (int)wblock->gblock.instance_count);
 699 }
 700 static DEVICE_ATTR_RO(instance_count);
 701
 702 static ssize_t expensive_show(struct device *dev,
 703                               struct device_attribute *attr, char *buf)
 704 {
 705         struct wmi_block *wblock = dev_to_wblock(dev);
 706
 707         return sprintf(buf, "%d\n",
 708                        (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
 709 }
 710 static DEVICE_ATTR_RO(expensive);
 711
 712 static struct attribute *wmi_attrs[] = {
 713         &dev_attr_modalias.attr,
 714         &dev_attr_guid.attr,
 715         &dev_attr_instance_count.attr,
 716         &dev_attr_expensive.attr,
 717         NULL,
 718 };
 719 ATTRIBUTE_GROUPS(wmi);
 720
 721 static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
 722                               char *buf)
 723 {
 724         struct wmi_block *wblock = dev_to_wblock(dev);
 725
 726         return sprintf(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
 727 }
 728 static DEVICE_ATTR_RO(notify_id);
 729
 730 static struct attribute *wmi_event_attrs[] = {
 731         &dev_attr_notify_id.attr,
 732         NULL,
 733 };
 734 ATTRIBUTE_GROUPS(wmi_event);
 735
 736 static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
 737                               char *buf)
 738 {
 739         struct wmi_block *wblock = dev_to_wblock(dev);
 740
 741         return sprintf(buf, "%c%c\n", wblock->gblock.object_id[0],
 742                        wblock->gblock.object_id[1]);
 743 }
 744 static DEVICE_ATTR_RO(object_id);
 745
 746 static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
 747                             char *buf)
 748 {
 749         struct wmi_device *wdev = dev_to_wdev(dev);
 750
 751         return sprintf(buf, "%d\n", (int)wdev->setable);
 752 }
 753 static DEVICE_ATTR_RO(setable);
 754
 755 static struct attribute *wmi_data_attrs[] = {
 756         &dev_attr_object_id.attr,
 757         &dev_attr_setable.attr,
 758         NULL,
 759 };
 760 ATTRIBUTE_GROUPS(wmi_data);
 761
 762 static struct attribute *wmi_method_attrs[] = {
 763         &dev_attr_object_id.attr,
 764         NULL,
 765 };
 766 ATTRIBUTE_GROUPS(wmi_method);
 767
 768 static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 769 {
 770         struct wmi_block *wblock = dev_to_wblock(dev);
 771
 772         if (add_uevent_var(env, "MODALIAS=wmi:%pUL", wblock->gblock.guid))
 773                 return -ENOMEM;
 774
 775         if (add_uevent_var(env, "WMI_GUID=%pUL", wblock->gblock.guid))
 776                 return -ENOMEM;
 777
 778         return 0;
 779 }
 780
 781 static void wmi_dev_release(struct device *dev)
 782 {
 783         struct wmi_block *wblock = dev_to_wblock(dev);
 784
 785         kfree(wblock);
 786 }
 787
 788 static int wmi_dev_match(struct device *dev, struct device_driver *driver)
 789 {
 790         struct wmi_driver *wmi_driver =
 791                 container_of(driver, struct wmi_driver, driver);
 792         struct wmi_block *wblock = dev_to_wblock(dev);
 793         const struct wmi_device_id *id = wmi_driver->id_table;
 794
 795         if (id == NULL)
 796                 return 0;
 797
 798         while (*id->guid_string) {
 799                 uuid_le driver_guid;
 800
 801                 if (WARN_ON(uuid_le_to_bin(id->guid_string, &driver_guid)))
 802                         continue;
 803                 if (!memcmp(&driver_guid, wblock->gblock.guid, 16))
 804                         return 1;
 805
 806                 id++;
 807         }
 808
 809         return 0;
 810 }
 811 static int wmi_char_open(struct inode *inode, struct file *filp)
 812 {
 813         const char *driver_name = filp->f_path.dentry->d_iname;
 814         struct wmi_block *wblock = NULL;
 815         struct wmi_block *next = NULL;
 816
 817         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
 818                 if (!wblock->dev.dev.driver)
 819                         continue;
 820                 if (strcmp(driver_name, wblock->dev.dev.driver->name) == 0) {
 821                         filp->private_data = wblock;
 822                         break;
 823                 }
 824         }
 825
 826         if (!filp->private_data)
 827                 return -ENODEV;
 828
 829         return nonseekable_open(inode, filp);
 830 }
 831
 832 static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
 833         size_t length, loff_t *offset)
 834 {
 835         struct wmi_block *wblock = filp->private_data;
 836
 837         return simple_read_from_buffer(buffer, length, offset,
 838                                        &wblock->req_buf_size,
 839                                        sizeof(wblock->req_buf_size));
 840 }
 841
 842 static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 843 {
 844         struct wmi_ioctl_buffer __user *input =
 845                 (struct wmi_ioctl_buffer __user *) arg;
 846         struct wmi_block *wblock = filp->private_data;
 847         struct wmi_ioctl_buffer *buf = NULL;
 848         struct wmi_driver *wdriver = NULL;
 849         int ret;
 850
 851         if (_IOC_TYPE(cmd) != WMI_IOC)
 852                 return -ENOTTY;
 853
 854         /* make sure we're not calling a higher instance than exists*/
 855         if (_IOC_NR(cmd) >= wblock->gblock.instance_count)
 856                 return -EINVAL;
 857
 858         mutex_lock(&wblock->char_mutex);
 859         buf = wblock->handler_data;
 860         if (get_user(buf->length, &input->length)) {
 861                 dev_dbg(&wblock->dev.dev, "Read length from user failed\n");
 862                 ret = -EFAULT;
 863                 goto out_ioctl;
 864         }
 865         /* if it's too small, abort */
 866         if (buf->length < wblock->req_buf_size) {
 867                 dev_err(&wblock->dev.dev,
 868                         "Buffer %lld too small, need at least %lld\n",
 869                         buf->length, wblock->req_buf_size);
 870                 ret = -EINVAL;
 871                 goto out_ioctl;
 872         }
 873         /* if it's too big, warn, driver will only use what is needed */
 874         if (buf->length > wblock->req_buf_size)
 875                 dev_warn(&wblock->dev.dev,
 876                         "Buffer %lld is bigger than required %lld\n",
 877                         buf->length, wblock->req_buf_size);
 878
 879         /* copy the structure from userspace */
 880         if (copy_from_user(buf, input, wblock->req_buf_size)) {
 881                 dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n",
 882                         wblock->req_buf_size);
 883                 ret = -EFAULT;
 884                 goto out_ioctl;
 885         }
 886
 887         /* let the driver do any filtering and do the call */
 888         wdriver = container_of(wblock->dev.dev.driver,
 889                                struct wmi_driver, driver);
 890         if (!try_module_get(wdriver->driver.owner)) {
 891                 ret = -EBUSY;
 892                 goto out_ioctl;
 893         }
 894         ret = wdriver->filter_callback(&wblock->dev, cmd, buf);
 895         module_put(wdriver->driver.owner);
 896         if (ret)
 897                 goto out_ioctl;
 898
 899         /* return the result (only up to our internal buffer size) */
 900         if (copy_to_user(input, buf, wblock->req_buf_size)) {
 901                 dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n",
 902                         wblock->req_buf_size);
 903                 ret = -EFAULT;
 904         }
 905
 906 out_ioctl:
 907         mutex_unlock(&wblock->char_mutex);
 908         return ret;
 909 }
 910
 911 static const struct file_operations wmi_fops = {
 912         .owner          = THIS_MODULE,
 913         .read           = wmi_char_read,
 914         .open           = wmi_char_open,
 915         .unlocked_ioctl = wmi_ioctl,
 916         .compat_ioctl   = wmi_ioctl,
 917 };
 918
 919 static int wmi_dev_probe(struct device *dev)
 920 {
 921         struct wmi_block *wblock = dev_to_wblock(dev);
 922         struct wmi_driver *wdriver =
 923                 container_of(dev->driver, struct wmi_driver, driver);
 924         int ret = 0;
 925         char *buf;
 926
 927         if (ACPI_FAILURE(wmi_method_enable(wblock, 1)))
 928                 dev_warn(dev, "failed to enable device -- probing anyway\n");
 929
 930         if (wdriver->probe) {
 931                 ret = wdriver->probe(dev_to_wdev(dev),
 932                                 find_guid_context(wblock, wdriver));
 933                 if (ret != 0)
 934                         goto probe_failure;
 935         }
 936
 937         /* driver wants a character device made */
 938         if (wdriver->filter_callback) {
 939                 /* check that required buffer size declared by driver or MOF */
 940                 if (!wblock->req_buf_size) {
 941                         dev_err(&wblock->dev.dev,
 942                                 "Required buffer size not set\n");
 943                         ret = -EINVAL;
 944                         goto probe_failure;
 945                 }
 946
 947                 wblock->handler_data = kmalloc(wblock->req_buf_size,
 948                                                GFP_KERNEL);
 949                 if (!wblock->handler_data) {
 950                         ret = -ENOMEM;
 951                         goto probe_failure;
 952                 }
 953
 954                 buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name);
 955                 if (!buf) {
 956                         ret = -ENOMEM;
 957                         goto probe_string_failure;
 958                 }
 959                 wblock->char_dev.minor = MISC_DYNAMIC_MINOR;
 960                 wblock->char_dev.name = buf;
 961                 wblock->char_dev.fops = &wmi_fops;
 962                 wblock->char_dev.mode = 0444;
 963                 ret = misc_register(&wblock->char_dev);
 964                 if (ret) {
 965                         dev_warn(dev, "failed to register char dev: %d\n", ret);
 966                         ret = -ENOMEM;
 967                         goto probe_misc_failure;
 968                 }
 969         }
 970
 971         return 0;
 972
 973 probe_misc_failure:
 974         kfree(buf);
 975 probe_string_failure:
 976         kfree(wblock->handler_data);
 977 probe_failure:
 978         if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
 979                 dev_warn(dev, "failed to disable device\n");
 980         return ret;
 981 }
 982
 983 static int wmi_dev_remove(struct device *dev)
 984 {
 985         struct wmi_block *wblock = dev_to_wblock(dev);
 986         struct wmi_driver *wdriver =
 987                 container_of(dev->driver, struct wmi_driver, driver);
 988         int ret = 0;
 989
 990         if (wdriver->filter_callback) {
 991                 misc_deregister(&wblock->char_dev);
 992                 kfree(wblock->char_dev.name);
 993                 kfree(wblock->handler_data);
 994         }
 995
 996         if (wdriver->remove)
 997                 ret = wdriver->remove(dev_to_wdev(dev));
 998
 999         if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
1000                 dev_warn(dev, "failed to disable device\n");
1001
1002         return ret;
1003 }
1004
1005 static struct class wmi_bus_class = {
1006         .name = "wmi_bus",
1007 };
1008
1009 static struct bus_type wmi_bus_type = {
1010         .name = "wmi",
1011         .dev_groups = wmi_groups,
1012         .match = wmi_dev_match,
1013         .uevent = wmi_dev_uevent,
1014         .probe = wmi_dev_probe,
1015         .remove = wmi_dev_remove,
1016 };
1017
1018 static const struct device_type wmi_type_event = {
1019         .name = "event",
1020         .groups = wmi_event_groups,
1021         .release = wmi_dev_release,
1022 };
1023
1024 static const struct device_type wmi_type_method = {
1025         .name = "method",
1026         .groups = wmi_method_groups,
1027         .release = wmi_dev_release,
1028 };
1029
1030 static const struct device_type wmi_type_data = {
1031         .name = "data",
1032         .groups = wmi_data_groups,
1033         .release = wmi_dev_release,
1034 };
1035
1036 static int wmi_create_device(struct device *wmi_bus_dev,
1037                              const struct guid_block *gblock,
1038                              struct wmi_block *wblock,
1039                              struct acpi_device *device)
1040 {
1041         struct acpi_device_info *info;
1042         char method[5];
1043         int result;
1044
1045         if (gblock->flags & ACPI_WMI_EVENT) {
1046                 wblock->dev.dev.type = &wmi_type_event;
1047                 goto out_init;
1048         }
1049
1050         if (gblock->flags & ACPI_WMI_METHOD) {
1051                 wblock->dev.dev.type = &wmi_type_method;
1052                 mutex_init(&wblock->char_mutex);
1053                 goto out_init;
1054         }
1055
1056         /*
1057          * Data Block Query Control Method (WQxx by convention) is
1058          * required per the WMI documentation. If it is not present,
1059          * we ignore this data block.
1060          */
1061         strcpy(method, "WQ");
1062         strncat(method, wblock->gblock.object_id, 2);
1063         result = get_subobj_info(device->handle, method, &info);
1064
1065         if (result) {
1066                 dev_warn(wmi_bus_dev,
1067                          "%s data block query control method not found\n",
1068                          method);
1069                 return result;
1070         }
1071
1072         wblock->dev.dev.type = &wmi_type_data;
1073
1074         /*
1075          * The Microsoft documentation specifically states:
1076          *
1077          *   Data blocks registered with only a single instance
1078          *   can ignore the parameter.
1079          *
1080          * ACPICA will get mad at us if we call the method with the wrong number
1081          * of arguments, so check what our method expects.  (On some Dell
1082          * laptops, WQxx may not be a method at all.)
1083          */
1084         if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1085                 wblock->read_takes_no_args = true;
1086
1087         kfree(info);
1088
1089         strcpy(method, "WS");
1090         strncat(method, wblock->gblock.object_id, 2);
1091         result = get_subobj_info(device->handle, method, NULL);
1092
1093         if (result == 0)
1094                 wblock->dev.setable = true;
1095
1096  out_init:
1097         wblock->dev.dev.bus = &wmi_bus_type;
1098         wblock->dev.dev.parent = wmi_bus_dev;
1099
1100         dev_set_name(&wblock->dev.dev, "%pUL", gblock->guid);
1101
1102         device_initialize(&wblock->dev.dev);
1103
1104         return 0;
1105 }
1106
1107 static void wmi_free_devices(struct acpi_device *device)
1108 {
1109         struct wmi_block *wblock, *next;
1110
1111         /* Delete devices for all the GUIDs */
1112         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1113                 if (wblock->acpi_device == device) {
1114                         list_del(&wblock->list);
1115                         device_unregister(&wblock->dev.dev);
1116                 }
1117         }
1118 }
1119
1120 static bool guid_already_parsed(struct acpi_device *device,
1121                                 const u8 *guid)
1122 {
1123         struct wmi_block *wblock;
1124
1125         list_for_each_entry(wblock, &wmi_block_list, list) {
1126                 if (memcmp(wblock->gblock.guid, guid, 16) == 0) {
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         int retval = 0;
1153         u32 i, total;
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                 retval = -ENXIO;
1165                 goto out_free_pointer;
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                         retval = -ENOMEM;
1187                         break;
1188                 }
1189
1190                 wblock->acpi_device = device;
1191                 wblock->gblock = gblock[i];
1192
1193                 retval = wmi_create_device(wmi_bus_dev, &gblock[i], 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 out_free_pointer:
1227         kfree(out.pointer);
1228         return retval;
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 guid_block *block;
1279         struct wmi_block *wblock;
1280         bool found_it = false;
1281
1282         list_for_each_entry(wblock, &wmi_block_list, list) {
1283                 block = &wblock->gblock;
1284
1285                 if (wblock->acpi_device->handle == handle &&
1286                     (block->flags & ACPI_WMI_EVENT) &&
1287                     (block->notify_id == event))
1288                 {
1289                         found_it = true;
1290                         break;
1291                 }
1292         }
1293
1294         if (!found_it)
1295                 return;
1296
1297         /* If a driver is bound, then notify the driver. */
1298         if (wblock->dev.dev.driver) {
1299                 struct wmi_driver *driver;
1300                 struct acpi_object_list input;
1301                 union acpi_object params[1];
1302                 struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL };
1303                 acpi_status status;
1304
1305                 driver = container_of(wblock->dev.dev.driver,
1306                                       struct wmi_driver, driver);
1307
1308                 input.count = 1;
1309                 input.pointer = params;
1310                 params[0].type = ACPI_TYPE_INTEGER;
1311                 params[0].integer.value = event;
1312
1313                 status = acpi_evaluate_object(wblock->acpi_device->handle,
1314                                               "_WED", &input, &evdata);
1315                 if (ACPI_FAILURE(status)) {
1316                         dev_warn(&wblock->dev.dev,
1317                                  "failed to get event data\n");
1318                         return;
1319                 }
1320
1321                 if (driver->notify)
1322                         driver->notify(&wblock->dev,
1323                                        (union acpi_object *)evdata.pointer);
1324
1325                 kfree(evdata.pointer);
1326         } else if (wblock->handler) {
1327                 /* Legacy handler */
1328                 wblock->handler(event, wblock->handler_data);
1329         }
1330
1331         if (debug_event) {
1332                 pr_info("DEBUG Event GUID: %pUL\n",
1333                         wblock->gblock.guid);
1334         }
1335
1336         acpi_bus_generate_netlink_event(
1337                 wblock->acpi_device->pnp.device_class,
1338                 dev_name(&wblock->dev.dev),
1339                 event, 0);
1340
1341 }
1342
1343 static int acpi_wmi_remove(struct platform_device *device)
1344 {
1345         struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev);
1346
1347         acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1348                                    acpi_wmi_notify_handler);
1349         acpi_remove_address_space_handler(acpi_device->handle,
1350                                 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
1351         wmi_free_devices(acpi_device);
1352         device_destroy(&wmi_bus_class, MKDEV(0, 0));
1353
1354         return 0;
1355 }
1356
1357 static int acpi_wmi_probe(struct platform_device *device)
1358 {
1359         struct acpi_device *acpi_device;
1360         struct device *wmi_bus_dev;
1361         acpi_status status;
1362         int error;
1363
1364         acpi_device = ACPI_COMPANION(&device->dev);
1365         if (!acpi_device) {
1366                 dev_err(&device->dev, "ACPI companion is missing\n");
1367                 return -ENODEV;
1368         }
1369
1370         status = acpi_install_address_space_handler(acpi_device->handle,
1371                                                     ACPI_ADR_SPACE_EC,
1372                                                     &acpi_wmi_ec_space_handler,
1373                                                     NULL, NULL);
1374         if (ACPI_FAILURE(status)) {
1375                 dev_err(&device->dev, "Error installing EC region handler\n");
1376                 return -ENODEV;
1377         }
1378
1379         status = acpi_install_notify_handler(acpi_device->handle,
1380                                              ACPI_DEVICE_NOTIFY,
1381                                              acpi_wmi_notify_handler,
1382                                              NULL);
1383         if (ACPI_FAILURE(status)) {
1384                 dev_err(&device->dev, "Error installing notify handler\n");
1385                 error = -ENODEV;
1386                 goto err_remove_ec_handler;
1387         }
1388
1389         wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0),
1390                                     NULL, "wmi_bus-%s", dev_name(&device->dev));
1391         if (IS_ERR(wmi_bus_dev)) {
1392                 error = PTR_ERR(wmi_bus_dev);
1393                 goto err_remove_notify_handler;
1394         }
1395         dev_set_drvdata(&device->dev, wmi_bus_dev);
1396
1397         error = parse_wdg(wmi_bus_dev, acpi_device);
1398         if (error) {
1399                 pr_err("Failed to parse WDG method\n");
1400                 goto err_remove_busdev;
1401         }
1402
1403         return 0;
1404
1405 err_remove_busdev:
1406         device_destroy(&wmi_bus_class, MKDEV(0, 0));
1407
1408 err_remove_notify_handler:
1409         acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1410                                    acpi_wmi_notify_handler);
1411
1412 err_remove_ec_handler:
1413         acpi_remove_address_space_handler(acpi_device->handle,
1414                                           ACPI_ADR_SPACE_EC,
1415                                           &acpi_wmi_ec_space_handler);
1416
1417         return error;
1418 }
1419
1420 int __must_check __wmi_driver_register(struct wmi_driver *driver,
1421                                        struct module *owner)
1422 {
1423         driver->driver.owner = owner;
1424         driver->driver.bus = &wmi_bus_type;
1425
1426         return driver_register(&driver->driver);
1427 }
1428 EXPORT_SYMBOL(__wmi_driver_register);
1429
1430 void wmi_driver_unregister(struct wmi_driver *driver)
1431 {
1432         driver_unregister(&driver->driver);
1433 }
1434 EXPORT_SYMBOL(wmi_driver_unregister);
1435
1436 static int __init acpi_wmi_init(void)
1437 {
1438         int error;
1439
1440         if (acpi_disabled)
1441                 return -ENODEV;
1442
1443         error = class_register(&wmi_bus_class);
1444         if (error)
1445                 return error;
1446
1447         error = bus_register(&wmi_bus_type);
1448         if (error)
1449                 goto err_unreg_class;
1450
1451         error = platform_driver_register(&acpi_wmi_driver);
1452         if (error) {
1453                 pr_err("Error loading mapper\n");
1454                 goto err_unreg_bus;
1455         }
1456
1457         return 0;
1458
1459 err_unreg_bus:
1460         bus_unregister(&wmi_bus_type);
1461
1462 err_unreg_class:
1463         class_unregister(&wmi_bus_class);
1464
1465         return error;
1466 }
1467
1468 static void __exit acpi_wmi_exit(void)
1469 {
1470         platform_driver_unregister(&acpi_wmi_driver);
1471         bus_unregister(&wmi_bus_type);
1472         class_unregister(&wmi_bus_class);
1473 }
1474
1475 subsys_initcall_sync(acpi_wmi_init);
1476 module_exit(acpi_wmi_exit);