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         char guid[16];
  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 (memcmp(block->guid, &guid_input, 16) == 0) {
 125                         if (out)
 126                                 *out = wblock;
 127                         return true;
 128                 }
 129         }
 130         return false;
 131 }
 132
 133 static const void *find_guid_context(struct wmi_block *wblock,
 134                                       struct wmi_driver *wdriver)
 135 {
 136         const struct wmi_device_id *id;
 137         guid_t guid_input;
 138
 139         if (wblock == NULL || wdriver == NULL)
 140                 return NULL;
 141         if (wdriver->id_table == NULL)
 142                 return NULL;
 143
 144         id = wdriver->id_table;
 145         while (*id->guid_string) {
 146                 if (guid_parse(id->guid_string, &guid_input))
 147                         continue;
 148                 if (!memcmp(wblock->gblock.guid, &guid_input, 16))
 149                         return id->context;
 150                 id++;
 151         }
 152         return NULL;
 153 }
 154
 155 static int get_subobj_info(acpi_handle handle, const char *pathname,
 156                            struct acpi_device_info **info)
 157 {
 158         struct acpi_device_info *dummy_info, **info_ptr;
 159         acpi_handle subobj_handle;
 160         acpi_status status;
 161
 162         status = acpi_get_handle(handle, (char *)pathname, &subobj_handle);
 163         if (status == AE_NOT_FOUND)
 164                 return -ENOENT;
 165         else if (ACPI_FAILURE(status))
 166                 return -EIO;
 167
 168         info_ptr = info ? info : &dummy_info;
 169         status = acpi_get_object_info(subobj_handle, info_ptr);
 170         if (ACPI_FAILURE(status))
 171                 return -EIO;
 172
 173         if (!info)
 174                 kfree(dummy_info);
 175
 176         return 0;
 177 }
 178
 179 static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable)
 180 {
 181         struct guid_block *block = NULL;
 182         char method[5];
 183         acpi_status status;
 184         acpi_handle handle;
 185
 186         block = &wblock->gblock;
 187         handle = wblock->acpi_device->handle;
 188
 189         snprintf(method, 5, "WE%02X", block->notify_id);
 190         status = acpi_execute_simple_method(handle, method, enable);
 191
 192         if (status != AE_OK && status != AE_NOT_FOUND)
 193                 return status;
 194         else
 195                 return AE_OK;
 196 }
 197
 198 /*
 199  * Exported WMI functions
 200  */
 201
 202 /**
 203  * set_required_buffer_size - Sets the buffer size needed for performing IOCTL
 204  * @wdev: A wmi bus device from a driver
 205  * @instance: Instance index
 206  *
 207  * Allocates memory needed for buffer, stores the buffer size in that memory
 208  */
 209 int set_required_buffer_size(struct wmi_device *wdev, u64 length)
 210 {
 211         struct wmi_block *wblock;
 212
 213         wblock = container_of(wdev, struct wmi_block, dev);
 214         wblock->req_buf_size = length;
 215
 216         return 0;
 217 }
 218 EXPORT_SYMBOL_GPL(set_required_buffer_size);
 219
 220 /**
 221  * wmi_evaluate_method - Evaluate a WMI method
 222  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 223  * @instance: Instance index
 224  * @method_id: Method ID to call
 225  * &in: Buffer containing input for the method call
 226  * &out: Empty buffer to return the method results
 227  *
 228  * Call an ACPI-WMI method
 229  */
 230 acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
 231 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
 232 {
 233         struct wmi_block *wblock = NULL;
 234
 235         if (!find_guid(guid_string, &wblock))
 236                 return AE_ERROR;
 237         return wmidev_evaluate_method(&wblock->dev, instance, method_id,
 238                                       in, out);
 239 }
 240 EXPORT_SYMBOL_GPL(wmi_evaluate_method);
 241
 242 /**
 243  * wmidev_evaluate_method - Evaluate a WMI method
 244  * @wdev: A wmi bus device from a driver
 245  * @instance: Instance index
 246  * @method_id: Method ID to call
 247  * &in: Buffer containing input for the method call
 248  * &out: Empty buffer to return the method results
 249  *
 250  * Call an ACPI-WMI method
 251  */
 252 acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance,
 253         u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
 254 {
 255         struct guid_block *block = NULL;
 256         struct wmi_block *wblock = NULL;
 257         acpi_handle handle;
 258         acpi_status status;
 259         struct acpi_object_list input;
 260         union acpi_object params[3];
 261         char method[5] = "WM";
 262
 263         wblock = container_of(wdev, struct wmi_block, dev);
 264         block = &wblock->gblock;
 265         handle = wblock->acpi_device->handle;
 266
 267         if (!(block->flags & ACPI_WMI_METHOD))
 268                 return AE_BAD_DATA;
 269
 270         if (block->instance_count <= instance)
 271                 return AE_BAD_PARAMETER;
 272
 273         input.count = 2;
 274         input.pointer = params;
 275         params[0].type = ACPI_TYPE_INTEGER;
 276         params[0].integer.value = instance;
 277         params[1].type = ACPI_TYPE_INTEGER;
 278         params[1].integer.value = method_id;
 279
 280         if (in) {
 281                 input.count = 3;
 282
 283                 if (block->flags & ACPI_WMI_STRING) {
 284                         params[2].type = ACPI_TYPE_STRING;
 285                 } else {
 286                         params[2].type = ACPI_TYPE_BUFFER;
 287                 }
 288                 params[2].buffer.length = in->length;
 289                 params[2].buffer.pointer = in->pointer;
 290         }
 291
 292         strncat(method, block->object_id, 2);
 293
 294         status = acpi_evaluate_object(handle, method, &input, out);
 295
 296         return status;
 297 }
 298 EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
 299
 300 static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
 301                                  struct acpi_buffer *out)
 302 {
 303         struct guid_block *block = NULL;
 304         acpi_handle handle;
 305         acpi_status status, wc_status = AE_ERROR;
 306         struct acpi_object_list input;
 307         union acpi_object wq_params[1];
 308         char method[5];
 309         char wc_method[5] = "WC";
 310
 311         if (!out)
 312                 return AE_BAD_PARAMETER;
 313
 314         block = &wblock->gblock;
 315         handle = wblock->acpi_device->handle;
 316
 317         if (block->instance_count <= instance)
 318                 return AE_BAD_PARAMETER;
 319
 320         /* Check GUID is a data block */
 321         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 322                 return AE_ERROR;
 323
 324         input.count = 1;
 325         input.pointer = wq_params;
 326         wq_params[0].type = ACPI_TYPE_INTEGER;
 327         wq_params[0].integer.value = instance;
 328
 329         if (instance == 0 && wblock->read_takes_no_args)
 330                 input.count = 0;
 331
 332         /*
 333          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
 334          * enable collection.
 335          */
 336         if (block->flags & ACPI_WMI_EXPENSIVE) {
 337                 strncat(wc_method, block->object_id, 2);
 338
 339                 /*
 340                  * Some GUIDs break the specification by declaring themselves
 341                  * expensive, but have no corresponding WCxx method. So we
 342                  * should not fail if this happens.
 343                  */
 344                 wc_status = acpi_execute_simple_method(handle, wc_method, 1);
 345         }
 346
 347         strcpy(method, "WQ");
 348         strncat(method, block->object_id, 2);
 349
 350         status = acpi_evaluate_object(handle, method, &input, out);
 351
 352         /*
 353          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
 354          * the WQxx method failed - we should disable collection anyway.
 355          */
 356         if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
 357                 status = acpi_execute_simple_method(handle, wc_method, 0);
 358         }
 359
 360         return status;
 361 }
 362
 363 /**
 364  * wmi_query_block - Return contents of a WMI block (deprecated)
 365  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 366  * @instance: Instance index
 367  * &out: Empty buffer to return the contents of the data block to
 368  *
 369  * Return the contents of an ACPI-WMI data block to a buffer
 370  */
 371 acpi_status wmi_query_block(const char *guid_string, u8 instance,
 372                             struct acpi_buffer *out)
 373 {
 374         struct wmi_block *wblock;
 375
 376         if (!guid_string)
 377                 return AE_BAD_PARAMETER;
 378
 379         if (!find_guid(guid_string, &wblock))
 380                 return AE_ERROR;
 381
 382         return __query_block(wblock, instance, out);
 383 }
 384 EXPORT_SYMBOL_GPL(wmi_query_block);
 385
 386 union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
 387 {
 388         struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
 389         struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
 390
 391         if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
 392                 return NULL;
 393
 394         return (union acpi_object *)out.pointer;
 395 }
 396 EXPORT_SYMBOL_GPL(wmidev_block_query);
 397
 398 /**
 399  * wmi_set_block - Write to a WMI block
 400  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 401  * @instance: Instance index
 402  * &in: Buffer containing new values for the data block
 403  *
 404  * Write the contents of the input buffer to an ACPI-WMI data block
 405  */
 406 acpi_status wmi_set_block(const char *guid_string, u8 instance,
 407                           const struct acpi_buffer *in)
 408 {
 409         struct guid_block *block = NULL;
 410         struct wmi_block *wblock = NULL;
 411         acpi_handle handle;
 412         struct acpi_object_list input;
 413         union acpi_object params[2];
 414         char method[5] = "WS";
 415
 416         if (!guid_string || !in)
 417                 return AE_BAD_DATA;
 418
 419         if (!find_guid(guid_string, &wblock))
 420                 return AE_ERROR;
 421
 422         block = &wblock->gblock;
 423         handle = wblock->acpi_device->handle;
 424
 425         if (block->instance_count <= instance)
 426                 return AE_BAD_PARAMETER;
 427
 428         /* Check GUID is a data block */
 429         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 430                 return AE_ERROR;
 431
 432         input.count = 2;
 433         input.pointer = params;
 434         params[0].type = ACPI_TYPE_INTEGER;
 435         params[0].integer.value = instance;
 436
 437         if (block->flags & ACPI_WMI_STRING) {
 438                 params[1].type = ACPI_TYPE_STRING;
 439         } else {
 440                 params[1].type = ACPI_TYPE_BUFFER;
 441         }
 442         params[1].buffer.length = in->length;
 443         params[1].buffer.pointer = in->pointer;
 444
 445         strncat(method, block->object_id, 2);
 446
 447         return acpi_evaluate_object(handle, method, &input, NULL);
 448 }
 449 EXPORT_SYMBOL_GPL(wmi_set_block);
 450
 451 static void wmi_dump_wdg(const struct guid_block *g)
 452 {
 453         pr_info("%pUL:\n", g->guid);
 454         if (g->flags & ACPI_WMI_EVENT)
 455                 pr_info("\tnotify_id: 0x%02X\n", g->notify_id);
 456         else
 457                 pr_info("\tobject_id: %2pE\n", g->object_id);
 458         pr_info("\tinstance_count: %d\n", g->instance_count);
 459         pr_info("\tflags: %#x", g->flags);
 460         if (g->flags) {
 461                 if (g->flags & ACPI_WMI_EXPENSIVE)
 462                         pr_cont(" ACPI_WMI_EXPENSIVE");
 463                 if (g->flags & ACPI_WMI_METHOD)
 464                         pr_cont(" ACPI_WMI_METHOD");
 465                 if (g->flags & ACPI_WMI_STRING)
 466                         pr_cont(" ACPI_WMI_STRING");
 467                 if (g->flags & ACPI_WMI_EVENT)
 468                         pr_cont(" ACPI_WMI_EVENT");
 469         }
 470         pr_cont("\n");
 471
 472 }
 473
 474 static void wmi_notify_debug(u32 value, void *context)
 475 {
 476         struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
 477         union acpi_object *obj;
 478         acpi_status status;
 479
 480         status = wmi_get_event_data(value, &response);
 481         if (status != AE_OK) {
 482                 pr_info("bad event status 0x%x\n", status);
 483                 return;
 484         }
 485
 486         obj = (union acpi_object *)response.pointer;
 487
 488         if (!obj)
 489                 return;
 490
 491         pr_info("DEBUG Event ");
 492         switch(obj->type) {
 493         case ACPI_TYPE_BUFFER:
 494                 pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
 495                 break;
 496         case ACPI_TYPE_STRING:
 497                 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
 498                 break;
 499         case ACPI_TYPE_INTEGER:
 500                 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
 501                 break;
 502         case ACPI_TYPE_PACKAGE:
 503                 pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
 504                 break;
 505         default:
 506                 pr_cont("object type 0x%X\n", obj->type);
 507         }
 508         kfree(obj);
 509 }
 510
 511 /**
 512  * wmi_install_notify_handler - Register handler for WMI events
 513  * @handler: Function to handle notifications
 514  * @data: Data to be returned to handler when event is fired
 515  *
 516  * Register a handler for events sent to the ACPI-WMI mapper device.
 517  */
 518 acpi_status wmi_install_notify_handler(const char *guid,
 519 wmi_notify_handler handler, void *data)
 520 {
 521         struct wmi_block *block;
 522         acpi_status status = AE_NOT_EXIST;
 523         guid_t guid_input;
 524
 525         if (!guid || !handler)
 526                 return AE_BAD_PARAMETER;
 527
 528         if (guid_parse(guid, &guid_input))
 529                 return AE_BAD_PARAMETER;
 530
 531         list_for_each_entry(block, &wmi_block_list, list) {
 532                 acpi_status wmi_status;
 533
 534                 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
 535                         if (block->handler &&
 536                             block->handler != wmi_notify_debug)
 537                                 return AE_ALREADY_ACQUIRED;
 538
 539                         block->handler = handler;
 540                         block->handler_data = data;
 541
 542                         wmi_status = wmi_method_enable(block, 1);
 543                         if ((wmi_status != AE_OK) ||
 544                             ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
 545                                 status = wmi_status;
 546                 }
 547         }
 548
 549         return status;
 550 }
 551 EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
 552
 553 /**
 554  * wmi_uninstall_notify_handler - Unregister handler for WMI events
 555  *
 556  * Unregister handler for events sent to the ACPI-WMI mapper device.
 557  */
 558 acpi_status wmi_remove_notify_handler(const char *guid)
 559 {
 560         struct wmi_block *block;
 561         acpi_status status = AE_NOT_EXIST;
 562         guid_t guid_input;
 563
 564         if (!guid)
 565                 return AE_BAD_PARAMETER;
 566
 567         if (guid_parse(guid, &guid_input))
 568                 return AE_BAD_PARAMETER;
 569
 570         list_for_each_entry(block, &wmi_block_list, list) {
 571                 acpi_status wmi_status;
 572
 573                 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
 574                         if (!block->handler ||
 575                             block->handler == wmi_notify_debug)
 576                                 return AE_NULL_ENTRY;
 577
 578                         if (debug_event) {
 579                                 block->handler = wmi_notify_debug;
 580                                 status = AE_OK;
 581                         } else {
 582                                 wmi_status = wmi_method_enable(block, 0);
 583                                 block->handler = NULL;
 584                                 block->handler_data = NULL;
 585                                 if ((wmi_status != AE_OK) ||
 586                                     ((wmi_status == AE_OK) &&
 587                                      (status == AE_NOT_EXIST)))
 588                                         status = wmi_status;
 589                         }
 590                 }
 591         }
 592
 593         return status;
 594 }
 595 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
 596
 597 /**
 598  * wmi_get_event_data - Get WMI data associated with an event
 599  *
 600  * @event: Event to find
 601  * @out: Buffer to hold event data. out->pointer should be freed with kfree()
 602  *
 603  * Returns extra data associated with an event in WMI.
 604  */
 605 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
 606 {
 607         struct acpi_object_list input;
 608         union acpi_object params[1];
 609         struct guid_block *gblock;
 610         struct wmi_block *wblock;
 611
 612         input.count = 1;
 613         input.pointer = params;
 614         params[0].type = ACPI_TYPE_INTEGER;
 615         params[0].integer.value = event;
 616
 617         list_for_each_entry(wblock, &wmi_block_list, list) {
 618                 gblock = &wblock->gblock;
 619
 620                 if ((gblock->flags & ACPI_WMI_EVENT) &&
 621                         (gblock->notify_id == event))
 622                         return acpi_evaluate_object(wblock->acpi_device->handle,
 623                                 "_WED", &input, out);
 624         }
 625
 626         return AE_NOT_FOUND;
 627 }
 628 EXPORT_SYMBOL_GPL(wmi_get_event_data);
 629
 630 /**
 631  * wmi_has_guid - Check if a GUID is available
 632  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 633  *
 634  * Check if a given GUID is defined by _WDG
 635  */
 636 bool wmi_has_guid(const char *guid_string)
 637 {
 638         return find_guid(guid_string, NULL);
 639 }
 640 EXPORT_SYMBOL_GPL(wmi_has_guid);
 641
 642 /**
 643  * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID
 644  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 645  *
 646  * Find the _UID of ACPI device associated with this WMI GUID.
 647  *
 648  * Return: The ACPI _UID field value or NULL if the WMI GUID was not found
 649  */
 650 char *wmi_get_acpi_device_uid(const char *guid_string)
 651 {
 652         struct wmi_block *wblock = NULL;
 653
 654         if (!find_guid(guid_string, &wblock))
 655                 return NULL;
 656
 657         return acpi_device_uid(wblock->acpi_device);
 658 }
 659 EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
 660
 661 static struct wmi_block *dev_to_wblock(struct device *dev)
 662 {
 663         return container_of(dev, struct wmi_block, dev.dev);
 664 }
 665
 666 static struct wmi_device *dev_to_wdev(struct device *dev)
 667 {
 668         return container_of(dev, struct wmi_device, dev);
 669 }
 670
 671 /*
 672  * sysfs interface
 673  */
 674 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 675                              char *buf)
 676 {
 677         struct wmi_block *wblock = dev_to_wblock(dev);
 678
 679         return sprintf(buf, "wmi:%pUL\n", wblock->gblock.guid);
 680 }
 681 static DEVICE_ATTR_RO(modalias);
 682
 683 static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
 684                          char *buf)
 685 {
 686         struct wmi_block *wblock = dev_to_wblock(dev);
 687
 688         return sprintf(buf, "%pUL\n", wblock->gblock.guid);
 689 }
 690 static DEVICE_ATTR_RO(guid);
 691
 692 static ssize_t instance_count_show(struct device *dev,
 693                                    struct device_attribute *attr, char *buf)
 694 {
 695         struct wmi_block *wblock = dev_to_wblock(dev);
 696
 697         return sprintf(buf, "%d\n", (int)wblock->gblock.instance_count);
 698 }
 699 static DEVICE_ATTR_RO(instance_count);
 700
 701 static ssize_t expensive_show(struct device *dev,
 702                               struct device_attribute *attr, char *buf)
 703 {
 704         struct wmi_block *wblock = dev_to_wblock(dev);
 705
 706         return sprintf(buf, "%d\n",
 707                        (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
 708 }
 709 static DEVICE_ATTR_RO(expensive);
 710
 711 static struct attribute *wmi_attrs[] = {
 712         &dev_attr_modalias.attr,
 713         &dev_attr_guid.attr,
 714         &dev_attr_instance_count.attr,
 715         &dev_attr_expensive.attr,
 716         NULL,
 717 };
 718 ATTRIBUTE_GROUPS(wmi);
 719
 720 static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
 721                               char *buf)
 722 {
 723         struct wmi_block *wblock = dev_to_wblock(dev);
 724
 725         return sprintf(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
 726 }
 727 static DEVICE_ATTR_RO(notify_id);
 728
 729 static struct attribute *wmi_event_attrs[] = {
 730         &dev_attr_notify_id.attr,
 731         NULL,
 732 };
 733 ATTRIBUTE_GROUPS(wmi_event);
 734
 735 static ssize_t object_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, "%c%c\n", wblock->gblock.object_id[0],
 741                        wblock->gblock.object_id[1]);
 742 }
 743 static DEVICE_ATTR_RO(object_id);
 744
 745 static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
 746                             char *buf)
 747 {
 748         struct wmi_device *wdev = dev_to_wdev(dev);
 749
 750         return sprintf(buf, "%d\n", (int)wdev->setable);
 751 }
 752 static DEVICE_ATTR_RO(setable);
 753
 754 static struct attribute *wmi_data_attrs[] = {
 755         &dev_attr_object_id.attr,
 756         &dev_attr_setable.attr,
 757         NULL,
 758 };
 759 ATTRIBUTE_GROUPS(wmi_data);
 760
 761 static struct attribute *wmi_method_attrs[] = {
 762         &dev_attr_object_id.attr,
 763         NULL,
 764 };
 765 ATTRIBUTE_GROUPS(wmi_method);
 766
 767 static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 768 {
 769         struct wmi_block *wblock = dev_to_wblock(dev);
 770
 771         if (add_uevent_var(env, "MODALIAS=wmi:%pUL", wblock->gblock.guid))
 772                 return -ENOMEM;
 773
 774         if (add_uevent_var(env, "WMI_GUID=%pUL", wblock->gblock.guid))
 775                 return -ENOMEM;
 776
 777         return 0;
 778 }
 779
 780 static void wmi_dev_release(struct device *dev)
 781 {
 782         struct wmi_block *wblock = dev_to_wblock(dev);
 783
 784         kfree(wblock);
 785 }
 786
 787 static int wmi_dev_match(struct device *dev, struct device_driver *driver)
 788 {
 789         struct wmi_driver *wmi_driver =
 790                 container_of(driver, struct wmi_driver, driver);
 791         struct wmi_block *wblock = dev_to_wblock(dev);
 792         const struct wmi_device_id *id = wmi_driver->id_table;
 793
 794         if (id == NULL)
 795                 return 0;
 796
 797         while (*id->guid_string) {
 798                 guid_t driver_guid;
 799
 800                 if (WARN_ON(guid_parse(id->guid_string, &driver_guid)))
 801                         continue;
 802                 if (!memcmp(&driver_guid, wblock->gblock.guid, 16))
 803                         return 1;
 804
 805                 id++;
 806         }
 807
 808         return 0;
 809 }
 810 static int wmi_char_open(struct inode *inode, struct file *filp)
 811 {
 812         const char *driver_name = filp->f_path.dentry->d_iname;
 813         struct wmi_block *wblock = NULL;
 814         struct wmi_block *next = NULL;
 815
 816         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
 817                 if (!wblock->dev.dev.driver)
 818                         continue;
 819                 if (strcmp(driver_name, wblock->dev.dev.driver->name) == 0) {
 820                         filp->private_data = wblock;
 821                         break;
 822                 }
 823         }
 824
 825         if (!filp->private_data)
 826                 return -ENODEV;
 827
 828         return nonseekable_open(inode, filp);
 829 }
 830
 831 static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
 832         size_t length, loff_t *offset)
 833 {
 834         struct wmi_block *wblock = filp->private_data;
 835
 836         return simple_read_from_buffer(buffer, length, offset,
 837                                        &wblock->req_buf_size,
 838                                        sizeof(wblock->req_buf_size));
 839 }
 840
 841 static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 842 {
 843         struct wmi_ioctl_buffer __user *input =
 844                 (struct wmi_ioctl_buffer __user *) arg;
 845         struct wmi_block *wblock = filp->private_data;
 846         struct wmi_ioctl_buffer *buf = NULL;
 847         struct wmi_driver *wdriver = NULL;
 848         int ret;
 849
 850         if (_IOC_TYPE(cmd) != WMI_IOC)
 851                 return -ENOTTY;
 852
 853         /* make sure we're not calling a higher instance than exists*/
 854         if (_IOC_NR(cmd) >= wblock->gblock.instance_count)
 855                 return -EINVAL;
 856
 857         mutex_lock(&wblock->char_mutex);
 858         buf = wblock->handler_data;
 859         if (get_user(buf->length, &input->length)) {
 860                 dev_dbg(&wblock->dev.dev, "Read length from user failed\n");
 861                 ret = -EFAULT;
 862                 goto out_ioctl;
 863         }
 864         /* if it's too small, abort */
 865         if (buf->length < wblock->req_buf_size) {
 866                 dev_err(&wblock->dev.dev,
 867                         "Buffer %lld too small, need at least %lld\n",
 868                         buf->length, wblock->req_buf_size);
 869                 ret = -EINVAL;
 870                 goto out_ioctl;
 871         }
 872         /* if it's too big, warn, driver will only use what is needed */
 873         if (buf->length > wblock->req_buf_size)
 874                 dev_warn(&wblock->dev.dev,
 875                         "Buffer %lld is bigger than required %lld\n",
 876                         buf->length, wblock->req_buf_size);
 877
 878         /* copy the structure from userspace */
 879         if (copy_from_user(buf, input, wblock->req_buf_size)) {
 880                 dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n",
 881                         wblock->req_buf_size);
 882                 ret = -EFAULT;
 883                 goto out_ioctl;
 884         }
 885
 886         /* let the driver do any filtering and do the call */
 887         wdriver = container_of(wblock->dev.dev.driver,
 888                                struct wmi_driver, driver);
 889         if (!try_module_get(wdriver->driver.owner)) {
 890                 ret = -EBUSY;
 891                 goto out_ioctl;
 892         }
 893         ret = wdriver->filter_callback(&wblock->dev, cmd, buf);
 894         module_put(wdriver->driver.owner);
 895         if (ret)
 896                 goto out_ioctl;
 897
 898         /* return the result (only up to our internal buffer size) */
 899         if (copy_to_user(input, buf, wblock->req_buf_size)) {
 900                 dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n",
 901                         wblock->req_buf_size);
 902                 ret = -EFAULT;
 903         }
 904
 905 out_ioctl:
 906         mutex_unlock(&wblock->char_mutex);
 907         return ret;
 908 }
 909
 910 static const struct file_operations wmi_fops = {
 911         .owner          = THIS_MODULE,
 912         .read           = wmi_char_read,
 913         .open           = wmi_char_open,
 914         .unlocked_ioctl = wmi_ioctl,
 915         .compat_ioctl   = compat_ptr_ioctl,
 916 };
 917
 918 static int wmi_dev_probe(struct device *dev)
 919 {
 920         struct wmi_block *wblock = dev_to_wblock(dev);
 921         struct wmi_driver *wdriver =
 922                 container_of(dev->driver, struct wmi_driver, driver);
 923         int ret = 0;
 924         char *buf;
 925
 926         if (ACPI_FAILURE(wmi_method_enable(wblock, 1)))
 927                 dev_warn(dev, "failed to enable device -- probing anyway\n");
 928
 929         if (wdriver->probe) {
 930                 ret = wdriver->probe(dev_to_wdev(dev),
 931                                 find_guid_context(wblock, wdriver));
 932                 if (ret != 0)
 933                         goto probe_failure;
 934         }
 935
 936         /* driver wants a character device made */
 937         if (wdriver->filter_callback) {
 938                 /* check that required buffer size declared by driver or MOF */
 939                 if (!wblock->req_buf_size) {
 940                         dev_err(&wblock->dev.dev,
 941                                 "Required buffer size not set\n");
 942                         ret = -EINVAL;
 943                         goto probe_failure;
 944                 }
 945
 946                 wblock->handler_data = kmalloc(wblock->req_buf_size,
 947                                                GFP_KERNEL);
 948                 if (!wblock->handler_data) {
 949                         ret = -ENOMEM;
 950                         goto probe_failure;
 951                 }
 952
 953                 buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name);
 954                 if (!buf) {
 955                         ret = -ENOMEM;
 956                         goto probe_string_failure;
 957                 }
 958                 wblock->char_dev.minor = MISC_DYNAMIC_MINOR;
 959                 wblock->char_dev.name = buf;
 960                 wblock->char_dev.fops = &wmi_fops;
 961                 wblock->char_dev.mode = 0444;
 962                 ret = misc_register(&wblock->char_dev);
 963                 if (ret) {
 964                         dev_warn(dev, "failed to register char dev: %d\n", ret);
 965                         ret = -ENOMEM;
 966                         goto probe_misc_failure;
 967                 }
 968         }
 969
 970         return 0;
 971
 972 probe_misc_failure:
 973         kfree(buf);
 974 probe_string_failure:
 975         kfree(wblock->handler_data);
 976 probe_failure:
 977         if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
 978                 dev_warn(dev, "failed to disable device\n");
 979         return ret;
 980 }
 981
 982 static int wmi_dev_remove(struct device *dev)
 983 {
 984         struct wmi_block *wblock = dev_to_wblock(dev);
 985         struct wmi_driver *wdriver =
 986                 container_of(dev->driver, struct wmi_driver, driver);
 987         int ret = 0;
 988
 989         if (wdriver->filter_callback) {
 990                 misc_deregister(&wblock->char_dev);
 991                 kfree(wblock->char_dev.name);
 992                 kfree(wblock->handler_data);
 993         }
 994
 995         if (wdriver->remove)
 996                 ret = wdriver->remove(dev_to_wdev(dev));
 997
 998         if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
 999                 dev_warn(dev, "failed to disable device\n");
1000
1001         return ret;
1002 }
1003
1004 static struct class wmi_bus_class = {
1005         .name = "wmi_bus",
1006 };
1007
1008 static struct bus_type wmi_bus_type = {
1009         .name = "wmi",
1010         .dev_groups = wmi_groups,
1011         .match = wmi_dev_match,
1012         .uevent = wmi_dev_uevent,
1013         .probe = wmi_dev_probe,
1014         .remove = wmi_dev_remove,
1015 };
1016
1017 static const struct device_type wmi_type_event = {
1018         .name = "event",
1019         .groups = wmi_event_groups,
1020         .release = wmi_dev_release,
1021 };
1022
1023 static const struct device_type wmi_type_method = {
1024         .name = "method",
1025         .groups = wmi_method_groups,
1026         .release = wmi_dev_release,
1027 };
1028
1029 static const struct device_type wmi_type_data = {
1030         .name = "data",
1031         .groups = wmi_data_groups,
1032         .release = wmi_dev_release,
1033 };
1034
1035 static int wmi_create_device(struct device *wmi_bus_dev,
1036                              const struct guid_block *gblock,
1037                              struct wmi_block *wblock,
1038                              struct acpi_device *device)
1039 {
1040         struct acpi_device_info *info;
1041         char method[5];
1042         int result;
1043
1044         if (gblock->flags & ACPI_WMI_EVENT) {
1045                 wblock->dev.dev.type = &wmi_type_event;
1046                 goto out_init;
1047         }
1048
1049         if (gblock->flags & ACPI_WMI_METHOD) {
1050                 wblock->dev.dev.type = &wmi_type_method;
1051                 mutex_init(&wblock->char_mutex);
1052                 goto out_init;
1053         }
1054
1055         /*
1056          * Data Block Query Control Method (WQxx by convention) is
1057          * required per the WMI documentation. If it is not present,
1058          * we ignore this data block.
1059          */
1060         strcpy(method, "WQ");
1061         strncat(method, wblock->gblock.object_id, 2);
1062         result = get_subobj_info(device->handle, method, &info);
1063
1064         if (result) {
1065                 dev_warn(wmi_bus_dev,
1066                          "%s data block query control method not found\n",
1067                          method);
1068                 return result;
1069         }
1070
1071         wblock->dev.dev.type = &wmi_type_data;
1072
1073         /*
1074          * The Microsoft documentation specifically states:
1075          *
1076          *   Data blocks registered with only a single instance
1077          *   can ignore the parameter.
1078          *
1079          * ACPICA will get mad at us if we call the method with the wrong number
1080          * of arguments, so check what our method expects.  (On some Dell
1081          * laptops, WQxx may not be a method at all.)
1082          */
1083         if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1084                 wblock->read_takes_no_args = true;
1085
1086         kfree(info);
1087
1088         strcpy(method, "WS");
1089         strncat(method, wblock->gblock.object_id, 2);
1090         result = get_subobj_info(device->handle, method, NULL);
1091
1092         if (result == 0)
1093                 wblock->dev.setable = true;
1094
1095  out_init:
1096         wblock->dev.dev.bus = &wmi_bus_type;
1097         wblock->dev.dev.parent = wmi_bus_dev;
1098
1099         dev_set_name(&wblock->dev.dev, "%pUL", gblock->guid);
1100
1101         device_initialize(&wblock->dev.dev);
1102
1103         return 0;
1104 }
1105
1106 static void wmi_free_devices(struct acpi_device *device)
1107 {
1108         struct wmi_block *wblock, *next;
1109
1110         /* Delete devices for all the GUIDs */
1111         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1112                 if (wblock->acpi_device == device) {
1113                         list_del(&wblock->list);
1114                         device_unregister(&wblock->dev.dev);
1115                 }
1116         }
1117 }
1118
1119 static bool guid_already_parsed(struct acpi_device *device,
1120                                 const u8 *guid)
1121 {
1122         struct wmi_block *wblock;
1123
1124         list_for_each_entry(wblock, &wmi_block_list, list) {
1125                 if (memcmp(wblock->gblock.guid, guid, 16) == 0) {
1126                         /*
1127                          * Because we historically didn't track the relationship
1128                          * between GUIDs and ACPI nodes, we don't know whether
1129                          * we need to suppress GUIDs that are unique on a
1130                          * given node but duplicated across nodes.
1131                          */
1132                         dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
1133                                  guid, dev_name(&wblock->acpi_device->dev));
1134                         return true;
1135                 }
1136         }
1137
1138         return false;
1139 }
1140
1141 /*
1142  * Parse the _WDG method for the GUID data blocks
1143  */
1144 static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
1145 {
1146         struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1147         const struct guid_block *gblock;
1148         struct wmi_block *wblock, *next;
1149         union acpi_object *obj;
1150         acpi_status status;
1151         int retval = 0;
1152         u32 i, total;
1153
1154         status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1155         if (ACPI_FAILURE(status))
1156                 return -ENXIO;
1157
1158         obj = (union acpi_object *) out.pointer;
1159         if (!obj)
1160                 return -ENXIO;
1161
1162         if (obj->type != ACPI_TYPE_BUFFER) {
1163                 retval = -ENXIO;
1164                 goto out_free_pointer;
1165         }
1166
1167         gblock = (const struct guid_block *)obj->buffer.pointer;
1168         total = obj->buffer.length / sizeof(struct guid_block);
1169
1170         for (i = 0; i < total; i++) {
1171                 if (debug_dump_wdg)
1172                         wmi_dump_wdg(&gblock[i]);
1173
1174                 /*
1175                  * Some WMI devices, like those for nVidia hooks, have a
1176                  * duplicate GUID. It's not clear what we should do in this
1177                  * case yet, so for now, we'll just ignore the duplicate
1178                  * for device creation.
1179                  */
1180                 if (guid_already_parsed(device, gblock[i].guid))
1181                         continue;
1182
1183                 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
1184                 if (!wblock) {
1185                         retval = -ENOMEM;
1186                         break;
1187                 }
1188
1189                 wblock->acpi_device = device;
1190                 wblock->gblock = gblock[i];
1191
1192                 retval = wmi_create_device(wmi_bus_dev, &gblock[i], wblock, device);
1193                 if (retval) {
1194                         kfree(wblock);
1195                         continue;
1196                 }
1197
1198                 list_add_tail(&wblock->list, &wmi_block_list);
1199
1200                 if (debug_event) {
1201                         wblock->handler = wmi_notify_debug;
1202                         wmi_method_enable(wblock, 1);
1203                 }
1204         }
1205
1206         /*
1207          * Now that all of the devices are created, add them to the
1208          * device tree and probe subdrivers.
1209          */
1210         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1211                 if (wblock->acpi_device != device)
1212                         continue;
1213
1214                 retval = device_add(&wblock->dev.dev);
1215                 if (retval) {
1216                         dev_err(wmi_bus_dev, "failed to register %pUL\n",
1217                                 wblock->gblock.guid);
1218                         if (debug_event)
1219                                 wmi_method_enable(wblock, 0);
1220                         list_del(&wblock->list);
1221                         put_device(&wblock->dev.dev);
1222                 }
1223         }
1224
1225 out_free_pointer:
1226         kfree(out.pointer);
1227         return retval;
1228 }
1229
1230 /*
1231  * WMI can have EmbeddedControl access regions. In which case, we just want to
1232  * hand these off to the EC driver.
1233  */
1234 static acpi_status
1235 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1236                       u32 bits, u64 *value,
1237                       void *handler_context, void *region_context)
1238 {
1239         int result = 0, i = 0;
1240         u8 temp = 0;
1241
1242         if ((address > 0xFF) || !value)
1243                 return AE_BAD_PARAMETER;
1244
1245         if (function != ACPI_READ && function != ACPI_WRITE)
1246                 return AE_BAD_PARAMETER;
1247
1248         if (bits != 8)
1249                 return AE_BAD_PARAMETER;
1250
1251         if (function == ACPI_READ) {
1252                 result = ec_read(address, &temp);
1253                 (*value) |= ((u64)temp) << i;
1254         } else {
1255                 temp = 0xff & ((*value) >> i);
1256                 result = ec_write(address, temp);
1257         }
1258
1259         switch (result) {
1260         case -EINVAL:
1261                 return AE_BAD_PARAMETER;
1262                 break;
1263         case -ENODEV:
1264                 return AE_NOT_FOUND;
1265                 break;
1266         case -ETIME:
1267                 return AE_TIME;
1268                 break;
1269         default:
1270                 return AE_OK;
1271         }
1272 }
1273
1274 static void acpi_wmi_notify_handler(acpi_handle handle, u32 event,
1275                                     void *context)
1276 {
1277         struct guid_block *block;
1278         struct wmi_block *wblock;
1279         bool found_it = false;
1280
1281         list_for_each_entry(wblock, &wmi_block_list, list) {
1282                 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",
1332                         wblock->gblock.guid);
1333         }
1334
1335         acpi_bus_generate_netlink_event(
1336                 wblock->acpi_device->pnp.device_class,
1337                 dev_name(&wblock->dev.dev),
1338                 event, 0);
1339
1340 }
1341
1342 static int acpi_wmi_remove(struct platform_device *device)
1343 {
1344         struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev);
1345
1346         acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1347                                    acpi_wmi_notify_handler);
1348         acpi_remove_address_space_handler(acpi_device->handle,
1349                                 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
1350         wmi_free_devices(acpi_device);
1351         device_destroy(&wmi_bus_class, MKDEV(0, 0));
1352
1353         return 0;
1354 }
1355
1356 static int acpi_wmi_probe(struct platform_device *device)
1357 {
1358         struct acpi_device *acpi_device;
1359         struct device *wmi_bus_dev;
1360         acpi_status status;
1361         int error;
1362
1363         acpi_device = ACPI_COMPANION(&device->dev);
1364         if (!acpi_device) {
1365                 dev_err(&device->dev, "ACPI companion is missing\n");
1366                 return -ENODEV;
1367         }
1368
1369         status = acpi_install_address_space_handler(acpi_device->handle,
1370                                                     ACPI_ADR_SPACE_EC,
1371                                                     &acpi_wmi_ec_space_handler,
1372                                                     NULL, NULL);
1373         if (ACPI_FAILURE(status)) {
1374                 dev_err(&device->dev, "Error installing EC region handler\n");
1375                 return -ENODEV;
1376         }
1377
1378         status = acpi_install_notify_handler(acpi_device->handle,
1379                                              ACPI_DEVICE_NOTIFY,
1380                                              acpi_wmi_notify_handler,
1381                                              NULL);
1382         if (ACPI_FAILURE(status)) {
1383                 dev_err(&device->dev, "Error installing notify handler\n");
1384                 error = -ENODEV;
1385                 goto err_remove_ec_handler;
1386         }
1387
1388         wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0),
1389                                     NULL, "wmi_bus-%s", dev_name(&device->dev));
1390         if (IS_ERR(wmi_bus_dev)) {
1391                 error = PTR_ERR(wmi_bus_dev);
1392                 goto err_remove_notify_handler;
1393         }
1394         dev_set_drvdata(&device->dev, wmi_bus_dev);
1395
1396         error = parse_wdg(wmi_bus_dev, acpi_device);
1397         if (error) {
1398                 pr_err("Failed to parse WDG method\n");
1399                 goto err_remove_busdev;
1400         }
1401
1402         return 0;
1403
1404 err_remove_busdev:
1405         device_destroy(&wmi_bus_class, MKDEV(0, 0));
1406
1407 err_remove_notify_handler:
1408         acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1409                                    acpi_wmi_notify_handler);
1410
1411 err_remove_ec_handler:
1412         acpi_remove_address_space_handler(acpi_device->handle,
1413                                           ACPI_ADR_SPACE_EC,
1414                                           &acpi_wmi_ec_space_handler);
1415
1416         return error;
1417 }
1418
1419 int __must_check __wmi_driver_register(struct wmi_driver *driver,
1420                                        struct module *owner)
1421 {
1422         driver->driver.owner = owner;
1423         driver->driver.bus = &wmi_bus_type;
1424
1425         return driver_register(&driver->driver);
1426 }
1427 EXPORT_SYMBOL(__wmi_driver_register);
1428
1429 void wmi_driver_unregister(struct wmi_driver *driver)
1430 {
1431         driver_unregister(&driver->driver);
1432 }
1433 EXPORT_SYMBOL(wmi_driver_unregister);
1434
1435 static int __init acpi_wmi_init(void)
1436 {
1437         int error;
1438
1439         if (acpi_disabled)
1440                 return -ENODEV;
1441
1442         error = class_register(&wmi_bus_class);
1443         if (error)
1444                 return error;
1445
1446         error = bus_register(&wmi_bus_type);
1447         if (error)
1448                 goto err_unreg_class;
1449
1450         error = platform_driver_register(&acpi_wmi_driver);
1451         if (error) {
1452                 pr_err("Error loading mapper\n");
1453                 goto err_unreg_bus;
1454         }
1455
1456         return 0;
1457
1458 err_unreg_bus:
1459         bus_unregister(&wmi_bus_type);
1460
1461 err_unreg_class:
1462         class_unregister(&wmi_bus_class);
1463
1464         return error;
1465 }
1466
1467 static void __exit acpi_wmi_exit(void)
1468 {
1469         platform_driver_unregister(&acpi_wmi_driver);
1470         bus_unregister(&wmi_bus_type);
1471         class_unregister(&wmi_bus_class);
1472 }
1473
1474 subsys_initcall_sync(acpi_wmi_init);
1475 module_exit(acpi_wmi_exit);