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  * @length: Required buffer size
 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                 /*
 358                  * Ignore whether this WCxx call succeeds or not since
 359                  * the previously executed WQxx method call might have
 360                  * succeeded, and returning the failing status code
 361                  * of this call would throw away the result of the WQxx
 362                  * call, potentially leaking memory.
 363                  */
 364                 acpi_execute_simple_method(handle, wc_method, 0);
 365         }
 366
 367         return status;
 368 }
 369
 370 /**
 371  * wmi_query_block - Return contents of a WMI block (deprecated)
 372  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 373  * @instance: Instance index
 374  * @out: Empty buffer to return the contents of the data block to
 375  *
 376  * Return the contents of an ACPI-WMI data block to a buffer
 377  */
 378 acpi_status wmi_query_block(const char *guid_string, u8 instance,
 379                             struct acpi_buffer *out)
 380 {
 381         struct wmi_block *wblock;
 382
 383         if (!guid_string)
 384                 return AE_BAD_PARAMETER;
 385
 386         if (!find_guid(guid_string, &wblock))
 387                 return AE_ERROR;
 388
 389         return __query_block(wblock, instance, out);
 390 }
 391 EXPORT_SYMBOL_GPL(wmi_query_block);
 392
 393 union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
 394 {
 395         struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
 396         struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
 397
 398         if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
 399                 return NULL;
 400
 401         return (union acpi_object *)out.pointer;
 402 }
 403 EXPORT_SYMBOL_GPL(wmidev_block_query);
 404
 405 /**
 406  * wmi_set_block - Write to a WMI block
 407  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 408  * @instance: Instance index
 409  * @in: Buffer containing new values for the data block
 410  *
 411  * Write the contents of the input buffer to an ACPI-WMI data block
 412  */
 413 acpi_status wmi_set_block(const char *guid_string, u8 instance,
 414                           const struct acpi_buffer *in)
 415 {
 416         struct guid_block *block = NULL;
 417         struct wmi_block *wblock = NULL;
 418         acpi_handle handle;
 419         struct acpi_object_list input;
 420         union acpi_object params[2];
 421         char method[5] = "WS";
 422
 423         if (!guid_string || !in)
 424                 return AE_BAD_DATA;
 425
 426         if (!find_guid(guid_string, &wblock))
 427                 return AE_ERROR;
 428
 429         block = &wblock->gblock;
 430         handle = wblock->acpi_device->handle;
 431
 432         if (block->instance_count <= instance)
 433                 return AE_BAD_PARAMETER;
 434
 435         /* Check GUID is a data block */
 436         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 437                 return AE_ERROR;
 438
 439         input.count = 2;
 440         input.pointer = params;
 441         params[0].type = ACPI_TYPE_INTEGER;
 442         params[0].integer.value = instance;
 443
 444         if (block->flags & ACPI_WMI_STRING) {
 445                 params[1].type = ACPI_TYPE_STRING;
 446         } else {
 447                 params[1].type = ACPI_TYPE_BUFFER;
 448         }
 449         params[1].buffer.length = in->length;
 450         params[1].buffer.pointer = in->pointer;
 451
 452         strncat(method, block->object_id, 2);
 453
 454         return acpi_evaluate_object(handle, method, &input, NULL);
 455 }
 456 EXPORT_SYMBOL_GPL(wmi_set_block);
 457
 458 static void wmi_dump_wdg(const struct guid_block *g)
 459 {
 460         pr_info("%pUL:\n", g->guid);
 461         if (g->flags & ACPI_WMI_EVENT)
 462                 pr_info("\tnotify_id: 0x%02X\n", g->notify_id);
 463         else
 464                 pr_info("\tobject_id: %2pE\n", g->object_id);
 465         pr_info("\tinstance_count: %d\n", g->instance_count);
 466         pr_info("\tflags: %#x", g->flags);
 467         if (g->flags) {
 468                 if (g->flags & ACPI_WMI_EXPENSIVE)
 469                         pr_cont(" ACPI_WMI_EXPENSIVE");
 470                 if (g->flags & ACPI_WMI_METHOD)
 471                         pr_cont(" ACPI_WMI_METHOD");
 472                 if (g->flags & ACPI_WMI_STRING)
 473                         pr_cont(" ACPI_WMI_STRING");
 474                 if (g->flags & ACPI_WMI_EVENT)
 475                         pr_cont(" ACPI_WMI_EVENT");
 476         }
 477         pr_cont("\n");
 478
 479 }
 480
 481 static void wmi_notify_debug(u32 value, void *context)
 482 {
 483         struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
 484         union acpi_object *obj;
 485         acpi_status status;
 486
 487         status = wmi_get_event_data(value, &response);
 488         if (status != AE_OK) {
 489                 pr_info("bad event status 0x%x\n", status);
 490                 return;
 491         }
 492
 493         obj = (union acpi_object *)response.pointer;
 494
 495         if (!obj)
 496                 return;
 497
 498         pr_info("DEBUG Event ");
 499         switch(obj->type) {
 500         case ACPI_TYPE_BUFFER:
 501                 pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
 502                 break;
 503         case ACPI_TYPE_STRING:
 504                 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
 505                 break;
 506         case ACPI_TYPE_INTEGER:
 507                 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
 508                 break;
 509         case ACPI_TYPE_PACKAGE:
 510                 pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
 511                 break;
 512         default:
 513                 pr_cont("object type 0x%X\n", obj->type);
 514         }
 515         kfree(obj);
 516 }
 517
 518 /**
 519  * wmi_install_notify_handler - Register handler for WMI events
 520  * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 521  * @handler: Function to handle notifications
 522  * @data: Data to be returned to handler when event is fired
 523  *
 524  * Register a handler for events sent to the ACPI-WMI mapper device.
 525  */
 526 acpi_status wmi_install_notify_handler(const char *guid,
 527 wmi_notify_handler handler, void *data)
 528 {
 529         struct wmi_block *block;
 530         acpi_status status = AE_NOT_EXIST;
 531         guid_t guid_input;
 532
 533         if (!guid || !handler)
 534                 return AE_BAD_PARAMETER;
 535
 536         if (guid_parse(guid, &guid_input))
 537                 return AE_BAD_PARAMETER;
 538
 539         list_for_each_entry(block, &wmi_block_list, list) {
 540                 acpi_status wmi_status;
 541
 542                 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
 543                         if (block->handler &&
 544                             block->handler != wmi_notify_debug)
 545                                 return AE_ALREADY_ACQUIRED;
 546
 547                         block->handler = handler;
 548                         block->handler_data = data;
 549
 550                         wmi_status = wmi_method_enable(block, 1);
 551                         if ((wmi_status != AE_OK) ||
 552                             ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
 553                                 status = wmi_status;
 554                 }
 555         }
 556
 557         return status;
 558 }
 559 EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
 560
 561 /**
 562  * wmi_uninstall_notify_handler - Unregister handler for WMI events
 563  * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 564  *
 565  * Unregister handler for events sent to the ACPI-WMI mapper device.
 566  */
 567 acpi_status wmi_remove_notify_handler(const char *guid)
 568 {
 569         struct wmi_block *block;
 570         acpi_status status = AE_NOT_EXIST;
 571         guid_t guid_input;
 572
 573         if (!guid)
 574                 return AE_BAD_PARAMETER;
 575
 576         if (guid_parse(guid, &guid_input))
 577                 return AE_BAD_PARAMETER;
 578
 579         list_for_each_entry(block, &wmi_block_list, list) {
 580                 acpi_status wmi_status;
 581
 582                 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
 583                         if (!block->handler ||
 584                             block->handler == wmi_notify_debug)
 585                                 return AE_NULL_ENTRY;
 586
 587                         if (debug_event) {
 588                                 block->handler = wmi_notify_debug;
 589                                 status = AE_OK;
 590                         } else {
 591                                 wmi_status = wmi_method_enable(block, 0);
 592                                 block->handler = NULL;
 593                                 block->handler_data = NULL;
 594                                 if ((wmi_status != AE_OK) ||
 595                                     ((wmi_status == AE_OK) &&
 596                                      (status == AE_NOT_EXIST)))
 597                                         status = wmi_status;
 598                         }
 599                 }
 600         }
 601
 602         return status;
 603 }
 604 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
 605
 606 /**
 607  * wmi_get_event_data - Get WMI data associated with an event
 608  *
 609  * @event: Event to find
 610  * @out: Buffer to hold event data. out->pointer should be freed with kfree()
 611  *
 612  * Returns extra data associated with an event in WMI.
 613  */
 614 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
 615 {
 616         struct acpi_object_list input;
 617         union acpi_object params[1];
 618         struct guid_block *gblock;
 619         struct wmi_block *wblock;
 620
 621         input.count = 1;
 622         input.pointer = params;
 623         params[0].type = ACPI_TYPE_INTEGER;
 624         params[0].integer.value = event;
 625
 626         list_for_each_entry(wblock, &wmi_block_list, list) {
 627                 gblock = &wblock->gblock;
 628
 629                 if ((gblock->flags & ACPI_WMI_EVENT) &&
 630                         (gblock->notify_id == event))
 631                         return acpi_evaluate_object(wblock->acpi_device->handle,
 632                                 "_WED", &input, out);
 633         }
 634
 635         return AE_NOT_FOUND;
 636 }
 637 EXPORT_SYMBOL_GPL(wmi_get_event_data);
 638
 639 /**
 640  * wmi_has_guid - Check if a GUID is available
 641  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 642  *
 643  * Check if a given GUID is defined by _WDG
 644  */
 645 bool wmi_has_guid(const char *guid_string)
 646 {
 647         return find_guid(guid_string, NULL);
 648 }
 649 EXPORT_SYMBOL_GPL(wmi_has_guid);
 650
 651 /**
 652  * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID
 653  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 654  *
 655  * Find the _UID of ACPI device associated with this WMI GUID.
 656  *
 657  * Return: The ACPI _UID field value or NULL if the WMI GUID was not found
 658  */
 659 char *wmi_get_acpi_device_uid(const char *guid_string)
 660 {
 661         struct wmi_block *wblock = NULL;
 662
 663         if (!find_guid(guid_string, &wblock))
 664                 return NULL;
 665
 666         return acpi_device_uid(wblock->acpi_device);
 667 }
 668 EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
 669
 670 static struct wmi_block *dev_to_wblock(struct device *dev)
 671 {
 672         return container_of(dev, struct wmi_block, dev.dev);
 673 }
 674
 675 static struct wmi_device *dev_to_wdev(struct device *dev)
 676 {
 677         return container_of(dev, struct wmi_device, dev);
 678 }
 679
 680 /*
 681  * sysfs interface
 682  */
 683 static ssize_t modalias_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, "wmi:%pUL\n", wblock->gblock.guid);
 689 }
 690 static DEVICE_ATTR_RO(modalias);
 691
 692 static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
 693                          char *buf)
 694 {
 695         struct wmi_block *wblock = dev_to_wblock(dev);
 696
 697         return sprintf(buf, "%pUL\n", wblock->gblock.guid);
 698 }
 699 static DEVICE_ATTR_RO(guid);
 700
 701 static ssize_t instance_count_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", (int)wblock->gblock.instance_count);
 707 }
 708 static DEVICE_ATTR_RO(instance_count);
 709
 710 static ssize_t expensive_show(struct device *dev,
 711                               struct device_attribute *attr, char *buf)
 712 {
 713         struct wmi_block *wblock = dev_to_wblock(dev);
 714
 715         return sprintf(buf, "%d\n",
 716                        (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
 717 }
 718 static DEVICE_ATTR_RO(expensive);
 719
 720 static struct attribute *wmi_attrs[] = {
 721         &dev_attr_modalias.attr,
 722         &dev_attr_guid.attr,
 723         &dev_attr_instance_count.attr,
 724         &dev_attr_expensive.attr,
 725         NULL,
 726 };
 727 ATTRIBUTE_GROUPS(wmi);
 728
 729 static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
 730                               char *buf)
 731 {
 732         struct wmi_block *wblock = dev_to_wblock(dev);
 733
 734         return sprintf(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
 735 }
 736 static DEVICE_ATTR_RO(notify_id);
 737
 738 static struct attribute *wmi_event_attrs[] = {
 739         &dev_attr_notify_id.attr,
 740         NULL,
 741 };
 742 ATTRIBUTE_GROUPS(wmi_event);
 743
 744 static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
 745                               char *buf)
 746 {
 747         struct wmi_block *wblock = dev_to_wblock(dev);
 748
 749         return sprintf(buf, "%c%c\n", wblock->gblock.object_id[0],
 750                        wblock->gblock.object_id[1]);
 751 }
 752 static DEVICE_ATTR_RO(object_id);
 753
 754 static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
 755                             char *buf)
 756 {
 757         struct wmi_device *wdev = dev_to_wdev(dev);
 758
 759         return sprintf(buf, "%d\n", (int)wdev->setable);
 760 }
 761 static DEVICE_ATTR_RO(setable);
 762
 763 static struct attribute *wmi_data_attrs[] = {
 764         &dev_attr_object_id.attr,
 765         &dev_attr_setable.attr,
 766         NULL,
 767 };
 768 ATTRIBUTE_GROUPS(wmi_data);
 769
 770 static struct attribute *wmi_method_attrs[] = {
 771         &dev_attr_object_id.attr,
 772         NULL,
 773 };
 774 ATTRIBUTE_GROUPS(wmi_method);
 775
 776 static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 777 {
 778         struct wmi_block *wblock = dev_to_wblock(dev);
 779
 780         if (add_uevent_var(env, "MODALIAS=wmi:%pUL", wblock->gblock.guid))
 781                 return -ENOMEM;
 782
 783         if (add_uevent_var(env, "WMI_GUID=%pUL", wblock->gblock.guid))
 784                 return -ENOMEM;
 785
 786         return 0;
 787 }
 788
 789 static void wmi_dev_release(struct device *dev)
 790 {
 791         struct wmi_block *wblock = dev_to_wblock(dev);
 792
 793         kfree(wblock);
 794 }
 795
 796 static int wmi_dev_match(struct device *dev, struct device_driver *driver)
 797 {
 798         struct wmi_driver *wmi_driver =
 799                 container_of(driver, struct wmi_driver, driver);
 800         struct wmi_block *wblock = dev_to_wblock(dev);
 801         const struct wmi_device_id *id = wmi_driver->id_table;
 802
 803         if (id == NULL)
 804                 return 0;
 805
 806         while (*id->guid_string) {
 807                 guid_t driver_guid;
 808
 809                 if (WARN_ON(guid_parse(id->guid_string, &driver_guid)))
 810                         continue;
 811                 if (!memcmp(&driver_guid, wblock->gblock.guid, 16))
 812                         return 1;
 813
 814                 id++;
 815         }
 816
 817         return 0;
 818 }
 819 static int wmi_char_open(struct inode *inode, struct file *filp)
 820 {
 821         const char *driver_name = filp->f_path.dentry->d_iname;
 822         struct wmi_block *wblock = NULL;
 823         struct wmi_block *next = NULL;
 824
 825         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
 826                 if (!wblock->dev.dev.driver)
 827                         continue;
 828                 if (strcmp(driver_name, wblock->dev.dev.driver->name) == 0) {
 829                         filp->private_data = wblock;
 830                         break;
 831                 }
 832         }
 833
 834         if (!filp->private_data)
 835                 return -ENODEV;
 836
 837         return nonseekable_open(inode, filp);
 838 }
 839
 840 static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
 841         size_t length, loff_t *offset)
 842 {
 843         struct wmi_block *wblock = filp->private_data;
 844
 845         return simple_read_from_buffer(buffer, length, offset,
 846                                        &wblock->req_buf_size,
 847                                        sizeof(wblock->req_buf_size));
 848 }
 849
 850 static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 851 {
 852         struct wmi_ioctl_buffer __user *input =
 853                 (struct wmi_ioctl_buffer __user *) arg;
 854         struct wmi_block *wblock = filp->private_data;
 855         struct wmi_ioctl_buffer *buf = NULL;
 856         struct wmi_driver *wdriver = NULL;
 857         int ret;
 858
 859         if (_IOC_TYPE(cmd) != WMI_IOC)
 860                 return -ENOTTY;
 861
 862         /* make sure we're not calling a higher instance than exists*/
 863         if (_IOC_NR(cmd) >= wblock->gblock.instance_count)
 864                 return -EINVAL;
 865
 866         mutex_lock(&wblock->char_mutex);
 867         buf = wblock->handler_data;
 868         if (get_user(buf->length, &input->length)) {
 869                 dev_dbg(&wblock->dev.dev, "Read length from user failed\n");
 870                 ret = -EFAULT;
 871                 goto out_ioctl;
 872         }
 873         /* if it's too small, abort */
 874         if (buf->length < wblock->req_buf_size) {
 875                 dev_err(&wblock->dev.dev,
 876                         "Buffer %lld too small, need at least %lld\n",
 877                         buf->length, wblock->req_buf_size);
 878                 ret = -EINVAL;
 879                 goto out_ioctl;
 880         }
 881         /* if it's too big, warn, driver will only use what is needed */
 882         if (buf->length > wblock->req_buf_size)
 883                 dev_warn(&wblock->dev.dev,
 884                         "Buffer %lld is bigger than required %lld\n",
 885                         buf->length, wblock->req_buf_size);
 886
 887         /* copy the structure from userspace */
 888         if (copy_from_user(buf, input, wblock->req_buf_size)) {
 889                 dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n",
 890                         wblock->req_buf_size);
 891                 ret = -EFAULT;
 892                 goto out_ioctl;
 893         }
 894
 895         /* let the driver do any filtering and do the call */
 896         wdriver = container_of(wblock->dev.dev.driver,
 897                                struct wmi_driver, driver);
 898         if (!try_module_get(wdriver->driver.owner)) {
 899                 ret = -EBUSY;
 900                 goto out_ioctl;
 901         }
 902         ret = wdriver->filter_callback(&wblock->dev, cmd, buf);
 903         module_put(wdriver->driver.owner);
 904         if (ret)
 905                 goto out_ioctl;
 906
 907         /* return the result (only up to our internal buffer size) */
 908         if (copy_to_user(input, buf, wblock->req_buf_size)) {
 909                 dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n",
 910                         wblock->req_buf_size);
 911                 ret = -EFAULT;
 912         }
 913
 914 out_ioctl:
 915         mutex_unlock(&wblock->char_mutex);
 916         return ret;
 917 }
 918
 919 static const struct file_operations wmi_fops = {
 920         .owner          = THIS_MODULE,
 921         .read           = wmi_char_read,
 922         .open           = wmi_char_open,
 923         .unlocked_ioctl = wmi_ioctl,
 924         .compat_ioctl   = compat_ptr_ioctl,
 925 };
 926
 927 static int wmi_dev_probe(struct device *dev)
 928 {
 929         struct wmi_block *wblock = dev_to_wblock(dev);
 930         struct wmi_driver *wdriver =
 931                 container_of(dev->driver, struct wmi_driver, driver);
 932         int ret = 0;
 933         char *buf;
 934
 935         if (ACPI_FAILURE(wmi_method_enable(wblock, 1)))
 936                 dev_warn(dev, "failed to enable device -- probing anyway\n");
 937
 938         if (wdriver->probe) {
 939                 ret = wdriver->probe(dev_to_wdev(dev),
 940                                 find_guid_context(wblock, wdriver));
 941                 if (ret != 0)
 942                         goto probe_failure;
 943         }
 944
 945         /* driver wants a character device made */
 946         if (wdriver->filter_callback) {
 947                 /* check that required buffer size declared by driver or MOF */
 948                 if (!wblock->req_buf_size) {
 949                         dev_err(&wblock->dev.dev,
 950                                 "Required buffer size not set\n");
 951                         ret = -EINVAL;
 952                         goto probe_failure;
 953                 }
 954
 955                 wblock->handler_data = kmalloc(wblock->req_buf_size,
 956                                                GFP_KERNEL);
 957                 if (!wblock->handler_data) {
 958                         ret = -ENOMEM;
 959                         goto probe_failure;
 960                 }
 961
 962                 buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name);
 963                 if (!buf) {
 964                         ret = -ENOMEM;
 965                         goto probe_string_failure;
 966                 }
 967                 wblock->char_dev.minor = MISC_DYNAMIC_MINOR;
 968                 wblock->char_dev.name = buf;
 969                 wblock->char_dev.fops = &wmi_fops;
 970                 wblock->char_dev.mode = 0444;
 971                 ret = misc_register(&wblock->char_dev);
 972                 if (ret) {
 973                         dev_warn(dev, "failed to register char dev: %d\n", ret);
 974                         ret = -ENOMEM;
 975                         goto probe_misc_failure;
 976                 }
 977         }
 978
 979         return 0;
 980
 981 probe_misc_failure:
 982         kfree(buf);
 983 probe_string_failure:
 984         kfree(wblock->handler_data);
 985 probe_failure:
 986         if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
 987                 dev_warn(dev, "failed to disable device\n");
 988         return ret;
 989 }
 990
 991 static int wmi_dev_remove(struct device *dev)
 992 {
 993         struct wmi_block *wblock = dev_to_wblock(dev);
 994         struct wmi_driver *wdriver =
 995                 container_of(dev->driver, struct wmi_driver, driver);
 996         int ret = 0;
 997
 998         if (wdriver->filter_callback) {
 999                 misc_deregister(&wblock->char_dev);
1000                 kfree(wblock->char_dev.name);
1001                 kfree(wblock->handler_data);
1002         }
1003
1004         if (wdriver->remove)
1005                 ret = wdriver->remove(dev_to_wdev(dev));
1006
1007         if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
1008                 dev_warn(dev, "failed to disable device\n");
1009
1010         return ret;
1011 }
1012
1013 static struct class wmi_bus_class = {
1014         .name = "wmi_bus",
1015 };
1016
1017 static struct bus_type wmi_bus_type = {
1018         .name = "wmi",
1019         .dev_groups = wmi_groups,
1020         .match = wmi_dev_match,
1021         .uevent = wmi_dev_uevent,
1022         .probe = wmi_dev_probe,
1023         .remove = wmi_dev_remove,
1024 };
1025
1026 static const struct device_type wmi_type_event = {
1027         .name = "event",
1028         .groups = wmi_event_groups,
1029         .release = wmi_dev_release,
1030 };
1031
1032 static const struct device_type wmi_type_method = {
1033         .name = "method",
1034         .groups = wmi_method_groups,
1035         .release = wmi_dev_release,
1036 };
1037
1038 static const struct device_type wmi_type_data = {
1039         .name = "data",
1040         .groups = wmi_data_groups,
1041         .release = wmi_dev_release,
1042 };
1043
1044 static int wmi_create_device(struct device *wmi_bus_dev,
1045                              const struct guid_block *gblock,
1046                              struct wmi_block *wblock,
1047                              struct acpi_device *device)
1048 {
1049         struct acpi_device_info *info;
1050         char method[5];
1051         int result;
1052
1053         if (gblock->flags & ACPI_WMI_EVENT) {
1054                 wblock->dev.dev.type = &wmi_type_event;
1055                 goto out_init;
1056         }
1057
1058         if (gblock->flags & ACPI_WMI_METHOD) {
1059                 wblock->dev.dev.type = &wmi_type_method;
1060                 mutex_init(&wblock->char_mutex);
1061                 goto out_init;
1062         }
1063
1064         /*
1065          * Data Block Query Control Method (WQxx by convention) is
1066          * required per the WMI documentation. If it is not present,
1067          * we ignore this data block.
1068          */
1069         strcpy(method, "WQ");
1070         strncat(method, wblock->gblock.object_id, 2);
1071         result = get_subobj_info(device->handle, method, &info);
1072
1073         if (result) {
1074                 dev_warn(wmi_bus_dev,
1075                          "%s data block query control method not found\n",
1076                          method);
1077                 return result;
1078         }
1079
1080         wblock->dev.dev.type = &wmi_type_data;
1081
1082         /*
1083          * The Microsoft documentation specifically states:
1084          *
1085          *   Data blocks registered with only a single instance
1086          *   can ignore the parameter.
1087          *
1088          * ACPICA will get mad at us if we call the method with the wrong number
1089          * of arguments, so check what our method expects.  (On some Dell
1090          * laptops, WQxx may not be a method at all.)
1091          */
1092         if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1093                 wblock->read_takes_no_args = true;
1094
1095         kfree(info);
1096
1097         strcpy(method, "WS");
1098         strncat(method, wblock->gblock.object_id, 2);
1099         result = get_subobj_info(device->handle, method, NULL);
1100
1101         if (result == 0)
1102                 wblock->dev.setable = true;
1103
1104  out_init:
1105         wblock->dev.dev.bus = &wmi_bus_type;
1106         wblock->dev.dev.parent = wmi_bus_dev;
1107
1108         dev_set_name(&wblock->dev.dev, "%pUL", gblock->guid);
1109
1110         device_initialize(&wblock->dev.dev);
1111
1112         return 0;
1113 }
1114
1115 static void wmi_free_devices(struct acpi_device *device)
1116 {
1117         struct wmi_block *wblock, *next;
1118
1119         /* Delete devices for all the GUIDs */
1120         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1121                 if (wblock->acpi_device == device) {
1122                         list_del(&wblock->list);
1123                         device_unregister(&wblock->dev.dev);
1124                 }
1125         }
1126 }
1127
1128 static bool guid_already_parsed(struct acpi_device *device, const u8 *guid)
1129 {
1130         struct wmi_block *wblock;
1131
1132         list_for_each_entry(wblock, &wmi_block_list, list) {
1133                 if (memcmp(wblock->gblock.guid, guid, 16) == 0) {
1134                         /*
1135                          * Because we historically didn't track the relationship
1136                          * between GUIDs and ACPI nodes, we don't know whether
1137                          * we need to suppress GUIDs that are unique on a
1138                          * given node but duplicated across nodes.
1139                          */
1140                         dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
1141                                  guid, dev_name(&wblock->acpi_device->dev));
1142                         return true;
1143                 }
1144         }
1145
1146         return false;
1147 }
1148
1149 /*
1150  * Parse the _WDG method for the GUID data blocks
1151  */
1152 static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
1153 {
1154         struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1155         const struct guid_block *gblock;
1156         struct wmi_block *wblock, *next;
1157         union acpi_object *obj;
1158         acpi_status status;
1159         int retval = 0;
1160         u32 i, total;
1161
1162         status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1163         if (ACPI_FAILURE(status))
1164                 return -ENXIO;
1165
1166         obj = (union acpi_object *) out.pointer;
1167         if (!obj)
1168                 return -ENXIO;
1169
1170         if (obj->type != ACPI_TYPE_BUFFER) {
1171                 retval = -ENXIO;
1172                 goto out_free_pointer;
1173         }
1174
1175         gblock = (const struct guid_block *)obj->buffer.pointer;
1176         total = obj->buffer.length / sizeof(struct guid_block);
1177
1178         for (i = 0; i < total; i++) {
1179                 if (debug_dump_wdg)
1180                         wmi_dump_wdg(&gblock[i]);
1181
1182                 /*
1183                  * Some WMI devices, like those for nVidia hooks, have a
1184                  * duplicate GUID. It's not clear what we should do in this
1185                  * case yet, so for now, we'll just ignore the duplicate
1186                  * for device creation.
1187                  */
1188                 if (guid_already_parsed(device, gblock[i].guid))
1189                         continue;
1190
1191                 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
1192                 if (!wblock) {
1193                         retval = -ENOMEM;
1194                         break;
1195                 }
1196
1197                 wblock->acpi_device = device;
1198                 wblock->gblock = gblock[i];
1199
1200                 retval = wmi_create_device(wmi_bus_dev, &gblock[i], wblock, device);
1201                 if (retval) {
1202                         kfree(wblock);
1203                         continue;
1204                 }
1205
1206                 list_add_tail(&wblock->list, &wmi_block_list);
1207
1208                 if (debug_event) {
1209                         wblock->handler = wmi_notify_debug;
1210                         wmi_method_enable(wblock, 1);
1211                 }
1212         }
1213
1214         /*
1215          * Now that all of the devices are created, add them to the
1216          * device tree and probe subdrivers.
1217          */
1218         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1219                 if (wblock->acpi_device != device)
1220                         continue;
1221
1222                 retval = device_add(&wblock->dev.dev);
1223                 if (retval) {
1224                         dev_err(wmi_bus_dev, "failed to register %pUL\n",
1225                                 wblock->gblock.guid);
1226                         if (debug_event)
1227                                 wmi_method_enable(wblock, 0);
1228                         list_del(&wblock->list);
1229                         put_device(&wblock->dev.dev);
1230                 }
1231         }
1232
1233 out_free_pointer:
1234         kfree(out.pointer);
1235         return retval;
1236 }
1237
1238 /*
1239  * WMI can have EmbeddedControl access regions. In which case, we just want to
1240  * hand these off to the EC driver.
1241  */
1242 static acpi_status
1243 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1244                       u32 bits, u64 *value,
1245                       void *handler_context, void *region_context)
1246 {
1247         int result = 0, i = 0;
1248         u8 temp = 0;
1249
1250         if ((address > 0xFF) || !value)
1251                 return AE_BAD_PARAMETER;
1252
1253         if (function != ACPI_READ && function != ACPI_WRITE)
1254                 return AE_BAD_PARAMETER;
1255
1256         if (bits != 8)
1257                 return AE_BAD_PARAMETER;
1258
1259         if (function == ACPI_READ) {
1260                 result = ec_read(address, &temp);
1261                 (*value) |= ((u64)temp) << i;
1262         } else {
1263                 temp = 0xff & ((*value) >> i);
1264                 result = ec_write(address, temp);
1265         }
1266
1267         switch (result) {
1268         case -EINVAL:
1269                 return AE_BAD_PARAMETER;
1270                 break;
1271         case -ENODEV:
1272                 return AE_NOT_FOUND;
1273                 break;
1274         case -ETIME:
1275                 return AE_TIME;
1276                 break;
1277         default:
1278                 return AE_OK;
1279         }
1280 }
1281
1282 static void acpi_wmi_notify_handler(acpi_handle handle, u32 event,
1283                                     void *context)
1284 {
1285         struct guid_block *block;
1286         struct wmi_block *wblock;
1287         bool found_it = false;
1288
1289         list_for_each_entry(wblock, &wmi_block_list, list) {
1290                 block = &wblock->gblock;
1291
1292                 if (wblock->acpi_device->handle == handle &&
1293                     (block->flags & ACPI_WMI_EVENT) &&
1294                     (block->notify_id == event))
1295                 {
1296                         found_it = true;
1297                         break;
1298                 }
1299         }
1300
1301         if (!found_it)
1302                 return;
1303
1304         /* If a driver is bound, then notify the driver. */
1305         if (wblock->dev.dev.driver) {
1306                 struct wmi_driver *driver;
1307                 struct acpi_object_list input;
1308                 union acpi_object params[1];
1309                 struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL };
1310                 acpi_status status;
1311
1312                 driver = container_of(wblock->dev.dev.driver,
1313                                       struct wmi_driver, driver);
1314
1315                 input.count = 1;
1316                 input.pointer = params;
1317                 params[0].type = ACPI_TYPE_INTEGER;
1318                 params[0].integer.value = event;
1319
1320                 status = acpi_evaluate_object(wblock->acpi_device->handle,
1321                                               "_WED", &input, &evdata);
1322                 if (ACPI_FAILURE(status)) {
1323                         dev_warn(&wblock->dev.dev,
1324                                  "failed to get event data\n");
1325                         return;
1326                 }
1327
1328                 if (driver->notify)
1329                         driver->notify(&wblock->dev,
1330                                        (union acpi_object *)evdata.pointer);
1331
1332                 kfree(evdata.pointer);
1333         } else if (wblock->handler) {
1334                 /* Legacy handler */
1335                 wblock->handler(event, wblock->handler_data);
1336         }
1337
1338         if (debug_event)
1339                 pr_info("DEBUG Event GUID: %pUL\n", wblock->gblock.guid);
1340
1341         acpi_bus_generate_netlink_event(
1342                 wblock->acpi_device->pnp.device_class,
1343                 dev_name(&wblock->dev.dev),
1344                 event, 0);
1345
1346 }
1347
1348 static int acpi_wmi_remove(struct platform_device *device)
1349 {
1350         struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev);
1351
1352         acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1353                                    acpi_wmi_notify_handler);
1354         acpi_remove_address_space_handler(acpi_device->handle,
1355                                 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
1356         wmi_free_devices(acpi_device);
1357         device_destroy(&wmi_bus_class, MKDEV(0, 0));
1358
1359         return 0;
1360 }
1361
1362 static int acpi_wmi_probe(struct platform_device *device)
1363 {
1364         struct acpi_device *acpi_device;
1365         struct device *wmi_bus_dev;
1366         acpi_status status;
1367         int error;
1368
1369         acpi_device = ACPI_COMPANION(&device->dev);
1370         if (!acpi_device) {
1371                 dev_err(&device->dev, "ACPI companion is missing\n");
1372                 return -ENODEV;
1373         }
1374
1375         status = acpi_install_address_space_handler(acpi_device->handle,
1376                                                     ACPI_ADR_SPACE_EC,
1377                                                     &acpi_wmi_ec_space_handler,
1378                                                     NULL, NULL);
1379         if (ACPI_FAILURE(status)) {
1380                 dev_err(&device->dev, "Error installing EC region handler\n");
1381                 return -ENODEV;
1382         }
1383
1384         status = acpi_install_notify_handler(acpi_device->handle,
1385                                              ACPI_DEVICE_NOTIFY,
1386                                              acpi_wmi_notify_handler,
1387                                              NULL);
1388         if (ACPI_FAILURE(status)) {
1389                 dev_err(&device->dev, "Error installing notify handler\n");
1390                 error = -ENODEV;
1391                 goto err_remove_ec_handler;
1392         }
1393
1394         wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0),
1395                                     NULL, "wmi_bus-%s", dev_name(&device->dev));
1396         if (IS_ERR(wmi_bus_dev)) {
1397                 error = PTR_ERR(wmi_bus_dev);
1398                 goto err_remove_notify_handler;
1399         }
1400         dev_set_drvdata(&device->dev, wmi_bus_dev);
1401
1402         error = parse_wdg(wmi_bus_dev, acpi_device);
1403         if (error) {
1404                 pr_err("Failed to parse WDG method\n");
1405                 goto err_remove_busdev;
1406         }
1407
1408         return 0;
1409
1410 err_remove_busdev:
1411         device_destroy(&wmi_bus_class, MKDEV(0, 0));
1412
1413 err_remove_notify_handler:
1414         acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1415                                    acpi_wmi_notify_handler);
1416
1417 err_remove_ec_handler:
1418         acpi_remove_address_space_handler(acpi_device->handle,
1419                                           ACPI_ADR_SPACE_EC,
1420                                           &acpi_wmi_ec_space_handler);
1421
1422         return error;
1423 }
1424
1425 int __must_check __wmi_driver_register(struct wmi_driver *driver,
1426                                        struct module *owner)
1427 {
1428         driver->driver.owner = owner;
1429         driver->driver.bus = &wmi_bus_type;
1430
1431         return driver_register(&driver->driver);
1432 }
1433 EXPORT_SYMBOL(__wmi_driver_register);
1434
1435 void wmi_driver_unregister(struct wmi_driver *driver)
1436 {
1437         driver_unregister(&driver->driver);
1438 }
1439 EXPORT_SYMBOL(wmi_driver_unregister);
1440
1441 static int __init acpi_wmi_init(void)
1442 {
1443         int error;
1444
1445         if (acpi_disabled)
1446                 return -ENODEV;
1447
1448         error = class_register(&wmi_bus_class);
1449         if (error)
1450                 return error;
1451
1452         error = bus_register(&wmi_bus_type);
1453         if (error)
1454                 goto err_unreg_class;
1455
1456         error = platform_driver_register(&acpi_wmi_driver);
1457         if (error) {
1458                 pr_err("Error loading mapper\n");
1459                 goto err_unreg_bus;
1460         }
1461
1462         return 0;
1463
1464 err_unreg_bus:
1465         bus_unregister(&wmi_bus_type);
1466
1467 err_unreg_class:
1468         class_unregister(&wmi_bus_class);
1469
1470         return error;
1471 }
1472
1473 static void __exit acpi_wmi_exit(void)
1474 {
1475         platform_driver_unregister(&acpi_wmi_driver);
1476         bus_unregister(&wmi_bus_type);
1477         class_unregister(&wmi_bus_class);
1478 }
1479
1480 subsys_initcall_sync(acpi_wmi_init);
1481 module_exit(acpi_wmi_exit);