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                 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  * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 514  * @handler: Function to handle notifications
 515  * @data: Data to be returned to handler when event is fired
 516  *
 517  * Register a handler for events sent to the ACPI-WMI mapper device.
 518  */
 519 acpi_status wmi_install_notify_handler(const char *guid,
 520 wmi_notify_handler handler, void *data)
 521 {
 522         struct wmi_block *block;
 523         acpi_status status = AE_NOT_EXIST;
 524         guid_t guid_input;
 525
 526         if (!guid || !handler)
 527                 return AE_BAD_PARAMETER;
 528
 529         if (guid_parse(guid, &guid_input))
 530                 return AE_BAD_PARAMETER;
 531
 532         list_for_each_entry(block, &wmi_block_list, list) {
 533                 acpi_status wmi_status;
 534
 535                 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
 536                         if (block->handler &&
 537                             block->handler != wmi_notify_debug)
 538                                 return AE_ALREADY_ACQUIRED;
 539
 540                         block->handler = handler;
 541                         block->handler_data = data;
 542
 543                         wmi_status = wmi_method_enable(block, 1);
 544                         if ((wmi_status != AE_OK) ||
 545                             ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
 546                                 status = wmi_status;
 547                 }
 548         }
 549
 550         return status;
 551 }
 552 EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
 553
 554 /**
 555  * wmi_uninstall_notify_handler - Unregister handler for WMI events
 556  * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 557  *
 558  * Unregister handler for events sent to the ACPI-WMI mapper device.
 559  */
 560 acpi_status wmi_remove_notify_handler(const char *guid)
 561 {
 562         struct wmi_block *block;
 563         acpi_status status = AE_NOT_EXIST;
 564         guid_t guid_input;
 565
 566         if (!guid)
 567                 return AE_BAD_PARAMETER;
 568
 569         if (guid_parse(guid, &guid_input))
 570                 return AE_BAD_PARAMETER;
 571
 572         list_for_each_entry(block, &wmi_block_list, list) {
 573                 acpi_status wmi_status;
 574
 575                 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
 576                         if (!block->handler ||
 577                             block->handler == wmi_notify_debug)
 578                                 return AE_NULL_ENTRY;
 579
 580                         if (debug_event) {
 581                                 block->handler = wmi_notify_debug;
 582                                 status = AE_OK;
 583                         } else {
 584                                 wmi_status = wmi_method_enable(block, 0);
 585                                 block->handler = NULL;
 586                                 block->handler_data = NULL;
 587                                 if ((wmi_status != AE_OK) ||
 588                                     ((wmi_status == AE_OK) &&
 589                                      (status == AE_NOT_EXIST)))
 590                                         status = wmi_status;
 591                         }
 592                 }
 593         }
 594
 595         return status;
 596 }
 597 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
 598
 599 /**
 600  * wmi_get_event_data - Get WMI data associated with an event
 601  *
 602  * @event: Event to find
 603  * @out: Buffer to hold event data. out->pointer should be freed with kfree()
 604  *
 605  * Returns extra data associated with an event in WMI.
 606  */
 607 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
 608 {
 609         struct acpi_object_list input;
 610         union acpi_object params[1];
 611         struct guid_block *gblock;
 612         struct wmi_block *wblock;
 613
 614         input.count = 1;
 615         input.pointer = params;
 616         params[0].type = ACPI_TYPE_INTEGER;
 617         params[0].integer.value = event;
 618
 619         list_for_each_entry(wblock, &wmi_block_list, list) {
 620                 gblock = &wblock->gblock;
 621
 622                 if ((gblock->flags & ACPI_WMI_EVENT) &&
 623                         (gblock->notify_id == event))
 624                         return acpi_evaluate_object(wblock->acpi_device->handle,
 625                                 "_WED", &input, out);
 626         }
 627
 628         return AE_NOT_FOUND;
 629 }
 630 EXPORT_SYMBOL_GPL(wmi_get_event_data);
 631
 632 /**
 633  * wmi_has_guid - Check if a GUID is available
 634  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 635  *
 636  * Check if a given GUID is defined by _WDG
 637  */
 638 bool wmi_has_guid(const char *guid_string)
 639 {
 640         return find_guid(guid_string, NULL);
 641 }
 642 EXPORT_SYMBOL_GPL(wmi_has_guid);
 643
 644 /**
 645  * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID
 646  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 647  *
 648  * Find the _UID of ACPI device associated with this WMI GUID.
 649  *
 650  * Return: The ACPI _UID field value or NULL if the WMI GUID was not found
 651  */
 652 char *wmi_get_acpi_device_uid(const char *guid_string)
 653 {
 654         struct wmi_block *wblock = NULL;
 655
 656         if (!find_guid(guid_string, &wblock))
 657                 return NULL;
 658
 659         return acpi_device_uid(wblock->acpi_device);
 660 }
 661 EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
 662
 663 static struct wmi_block *dev_to_wblock(struct device *dev)
 664 {
 665         return container_of(dev, struct wmi_block, dev.dev);
 666 }
 667
 668 static struct wmi_device *dev_to_wdev(struct device *dev)
 669 {
 670         return container_of(dev, struct wmi_device, dev);
 671 }
 672
 673 /*
 674  * sysfs interface
 675  */
 676 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 677                              char *buf)
 678 {
 679         struct wmi_block *wblock = dev_to_wblock(dev);
 680
 681         return sprintf(buf, "wmi:%pUL\n", wblock->gblock.guid);
 682 }
 683 static DEVICE_ATTR_RO(modalias);
 684
 685 static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
 686                          char *buf)
 687 {
 688         struct wmi_block *wblock = dev_to_wblock(dev);
 689
 690         return sprintf(buf, "%pUL\n", wblock->gblock.guid);
 691 }
 692 static DEVICE_ATTR_RO(guid);
 693
 694 static ssize_t instance_count_show(struct device *dev,
 695                                    struct device_attribute *attr, char *buf)
 696 {
 697         struct wmi_block *wblock = dev_to_wblock(dev);
 698
 699         return sprintf(buf, "%d\n", (int)wblock->gblock.instance_count);
 700 }
 701 static DEVICE_ATTR_RO(instance_count);
 702
 703 static ssize_t expensive_show(struct device *dev,
 704                               struct device_attribute *attr, char *buf)
 705 {
 706         struct wmi_block *wblock = dev_to_wblock(dev);
 707
 708         return sprintf(buf, "%d\n",
 709                        (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
 710 }
 711 static DEVICE_ATTR_RO(expensive);
 712
 713 static struct attribute *wmi_attrs[] = {
 714         &dev_attr_modalias.attr,
 715         &dev_attr_guid.attr,
 716         &dev_attr_instance_count.attr,
 717         &dev_attr_expensive.attr,
 718         NULL,
 719 };
 720 ATTRIBUTE_GROUPS(wmi);
 721
 722 static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
 723                               char *buf)
 724 {
 725         struct wmi_block *wblock = dev_to_wblock(dev);
 726
 727         return sprintf(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
 728 }
 729 static DEVICE_ATTR_RO(notify_id);
 730
 731 static struct attribute *wmi_event_attrs[] = {
 732         &dev_attr_notify_id.attr,
 733         NULL,
 734 };
 735 ATTRIBUTE_GROUPS(wmi_event);
 736
 737 static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
 738                               char *buf)
 739 {
 740         struct wmi_block *wblock = dev_to_wblock(dev);
 741
 742         return sprintf(buf, "%c%c\n", wblock->gblock.object_id[0],
 743                        wblock->gblock.object_id[1]);
 744 }
 745 static DEVICE_ATTR_RO(object_id);
 746
 747 static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
 748                             char *buf)
 749 {
 750         struct wmi_device *wdev = dev_to_wdev(dev);
 751
 752         return sprintf(buf, "%d\n", (int)wdev->setable);
 753 }
 754 static DEVICE_ATTR_RO(setable);
 755
 756 static struct attribute *wmi_data_attrs[] = {
 757         &dev_attr_object_id.attr,
 758         &dev_attr_setable.attr,
 759         NULL,
 760 };
 761 ATTRIBUTE_GROUPS(wmi_data);
 762
 763 static struct attribute *wmi_method_attrs[] = {
 764         &dev_attr_object_id.attr,
 765         NULL,
 766 };
 767 ATTRIBUTE_GROUPS(wmi_method);
 768
 769 static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 770 {
 771         struct wmi_block *wblock = dev_to_wblock(dev);
 772
 773         if (add_uevent_var(env, "MODALIAS=wmi:%pUL", wblock->gblock.guid))
 774                 return -ENOMEM;
 775
 776         if (add_uevent_var(env, "WMI_GUID=%pUL", wblock->gblock.guid))
 777                 return -ENOMEM;
 778
 779         return 0;
 780 }
 781
 782 static void wmi_dev_release(struct device *dev)
 783 {
 784         struct wmi_block *wblock = dev_to_wblock(dev);
 785
 786         kfree(wblock);
 787 }
 788
 789 static int wmi_dev_match(struct device *dev, struct device_driver *driver)
 790 {
 791         struct wmi_driver *wmi_driver =
 792                 container_of(driver, struct wmi_driver, driver);
 793         struct wmi_block *wblock = dev_to_wblock(dev);
 794         const struct wmi_device_id *id = wmi_driver->id_table;
 795
 796         if (id == NULL)
 797                 return 0;
 798
 799         while (*id->guid_string) {
 800                 guid_t driver_guid;
 801
 802                 if (WARN_ON(guid_parse(id->guid_string, &driver_guid)))
 803                         continue;
 804                 if (!memcmp(&driver_guid, wblock->gblock.guid, 16))
 805                         return 1;
 806
 807                 id++;
 808         }
 809
 810         return 0;
 811 }
 812 static int wmi_char_open(struct inode *inode, struct file *filp)
 813 {
 814         const char *driver_name = filp->f_path.dentry->d_iname;
 815         struct wmi_block *wblock = NULL;
 816         struct wmi_block *next = NULL;
 817
 818         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
 819                 if (!wblock->dev.dev.driver)
 820                         continue;
 821                 if (strcmp(driver_name, wblock->dev.dev.driver->name) == 0) {
 822                         filp->private_data = wblock;
 823                         break;
 824                 }
 825         }
 826
 827         if (!filp->private_data)
 828                 return -ENODEV;
 829
 830         return nonseekable_open(inode, filp);
 831 }
 832
 833 static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
 834         size_t length, loff_t *offset)
 835 {
 836         struct wmi_block *wblock = filp->private_data;
 837
 838         return simple_read_from_buffer(buffer, length, offset,
 839                                        &wblock->req_buf_size,
 840                                        sizeof(wblock->req_buf_size));
 841 }
 842
 843 static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 844 {
 845         struct wmi_ioctl_buffer __user *input =
 846                 (struct wmi_ioctl_buffer __user *) arg;
 847         struct wmi_block *wblock = filp->private_data;
 848         struct wmi_ioctl_buffer *buf = NULL;
 849         struct wmi_driver *wdriver = NULL;
 850         int ret;
 851
 852         if (_IOC_TYPE(cmd) != WMI_IOC)
 853                 return -ENOTTY;
 854
 855         /* make sure we're not calling a higher instance than exists*/
 856         if (_IOC_NR(cmd) >= wblock->gblock.instance_count)
 857                 return -EINVAL;
 858
 859         mutex_lock(&wblock->char_mutex);
 860         buf = wblock->handler_data;
 861         if (get_user(buf->length, &input->length)) {
 862                 dev_dbg(&wblock->dev.dev, "Read length from user failed\n");
 863                 ret = -EFAULT;
 864                 goto out_ioctl;
 865         }
 866         /* if it's too small, abort */
 867         if (buf->length < wblock->req_buf_size) {
 868                 dev_err(&wblock->dev.dev,
 869                         "Buffer %lld too small, need at least %lld\n",
 870                         buf->length, wblock->req_buf_size);
 871                 ret = -EINVAL;
 872                 goto out_ioctl;
 873         }
 874         /* if it's too big, warn, driver will only use what is needed */
 875         if (buf->length > wblock->req_buf_size)
 876                 dev_warn(&wblock->dev.dev,
 877                         "Buffer %lld is bigger than required %lld\n",
 878                         buf->length, wblock->req_buf_size);
 879
 880         /* copy the structure from userspace */
 881         if (copy_from_user(buf, input, wblock->req_buf_size)) {
 882                 dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n",
 883                         wblock->req_buf_size);
 884                 ret = -EFAULT;
 885                 goto out_ioctl;
 886         }
 887
 888         /* let the driver do any filtering and do the call */
 889         wdriver = container_of(wblock->dev.dev.driver,
 890                                struct wmi_driver, driver);
 891         if (!try_module_get(wdriver->driver.owner)) {
 892                 ret = -EBUSY;
 893                 goto out_ioctl;
 894         }
 895         ret = wdriver->filter_callback(&wblock->dev, cmd, buf);
 896         module_put(wdriver->driver.owner);
 897         if (ret)
 898                 goto out_ioctl;
 899
 900         /* return the result (only up to our internal buffer size) */
 901         if (copy_to_user(input, buf, wblock->req_buf_size)) {
 902                 dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n",
 903                         wblock->req_buf_size);
 904                 ret = -EFAULT;
 905         }
 906
 907 out_ioctl:
 908         mutex_unlock(&wblock->char_mutex);
 909         return ret;
 910 }
 911
 912 static const struct file_operations wmi_fops = {
 913         .owner          = THIS_MODULE,
 914         .read           = wmi_char_read,
 915         .open           = wmi_char_open,
 916         .unlocked_ioctl = wmi_ioctl,
 917         .compat_ioctl   = compat_ptr_ioctl,
 918 };
 919
 920 static int wmi_dev_probe(struct device *dev)
 921 {
 922         struct wmi_block *wblock = dev_to_wblock(dev);
 923         struct wmi_driver *wdriver =
 924                 container_of(dev->driver, struct wmi_driver, driver);
 925         int ret = 0;
 926         char *buf;
 927
 928         if (ACPI_FAILURE(wmi_method_enable(wblock, 1)))
 929                 dev_warn(dev, "failed to enable device -- probing anyway\n");
 930
 931         if (wdriver->probe) {
 932                 ret = wdriver->probe(dev_to_wdev(dev),
 933                                 find_guid_context(wblock, wdriver));
 934                 if (ret != 0)
 935                         goto probe_failure;
 936         }
 937
 938         /* driver wants a character device made */
 939         if (wdriver->filter_callback) {
 940                 /* check that required buffer size declared by driver or MOF */
 941                 if (!wblock->req_buf_size) {
 942                         dev_err(&wblock->dev.dev,
 943                                 "Required buffer size not set\n");
 944                         ret = -EINVAL;
 945                         goto probe_failure;
 946                 }
 947
 948                 wblock->handler_data = kmalloc(wblock->req_buf_size,
 949                                                GFP_KERNEL);
 950                 if (!wblock->handler_data) {
 951                         ret = -ENOMEM;
 952                         goto probe_failure;
 953                 }
 954
 955                 buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name);
 956                 if (!buf) {
 957                         ret = -ENOMEM;
 958                         goto probe_string_failure;
 959                 }
 960                 wblock->char_dev.minor = MISC_DYNAMIC_MINOR;
 961                 wblock->char_dev.name = buf;
 962                 wblock->char_dev.fops = &wmi_fops;
 963                 wblock->char_dev.mode = 0444;
 964                 ret = misc_register(&wblock->char_dev);
 965                 if (ret) {
 966                         dev_warn(dev, "failed to register char dev: %d\n", ret);
 967                         ret = -ENOMEM;
 968                         goto probe_misc_failure;
 969                 }
 970         }
 971
 972         return 0;
 973
 974 probe_misc_failure:
 975         kfree(buf);
 976 probe_string_failure:
 977         kfree(wblock->handler_data);
 978 probe_failure:
 979         if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
 980                 dev_warn(dev, "failed to disable device\n");
 981         return ret;
 982 }
 983
 984 static int wmi_dev_remove(struct device *dev)
 985 {
 986         struct wmi_block *wblock = dev_to_wblock(dev);
 987         struct wmi_driver *wdriver =
 988                 container_of(dev->driver, struct wmi_driver, driver);
 989         int ret = 0;
 990
 991         if (wdriver->filter_callback) {
 992                 misc_deregister(&wblock->char_dev);
 993                 kfree(wblock->char_dev.name);
 994                 kfree(wblock->handler_data);
 995         }
 996
 997         if (wdriver->remove)
 998                 ret = wdriver->remove(dev_to_wdev(dev));
 999
1000         if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
1001                 dev_warn(dev, "failed to disable device\n");
1002
1003         return ret;
1004 }
1005
1006 static struct class wmi_bus_class = {
1007         .name = "wmi_bus",
1008 };
1009
1010 static struct bus_type wmi_bus_type = {
1011         .name = "wmi",
1012         .dev_groups = wmi_groups,
1013         .match = wmi_dev_match,
1014         .uevent = wmi_dev_uevent,
1015         .probe = wmi_dev_probe,
1016         .remove = wmi_dev_remove,
1017 };
1018
1019 static const struct device_type wmi_type_event = {
1020         .name = "event",
1021         .groups = wmi_event_groups,
1022         .release = wmi_dev_release,
1023 };
1024
1025 static const struct device_type wmi_type_method = {
1026         .name = "method",
1027         .groups = wmi_method_groups,
1028         .release = wmi_dev_release,
1029 };
1030
1031 static const struct device_type wmi_type_data = {
1032         .name = "data",
1033         .groups = wmi_data_groups,
1034         .release = wmi_dev_release,
1035 };
1036
1037 static int wmi_create_device(struct device *wmi_bus_dev,
1038                              const struct guid_block *gblock,
1039                              struct wmi_block *wblock,
1040                              struct acpi_device *device)
1041 {
1042         struct acpi_device_info *info;
1043         char method[5];
1044         int result;
1045
1046         if (gblock->flags & ACPI_WMI_EVENT) {
1047                 wblock->dev.dev.type = &wmi_type_event;
1048                 goto out_init;
1049         }
1050
1051         if (gblock->flags & ACPI_WMI_METHOD) {
1052                 wblock->dev.dev.type = &wmi_type_method;
1053                 mutex_init(&wblock->char_mutex);
1054                 goto out_init;
1055         }
1056
1057         /*
1058          * Data Block Query Control Method (WQxx by convention) is
1059          * required per the WMI documentation. If it is not present,
1060          * we ignore this data block.
1061          */
1062         strcpy(method, "WQ");
1063         strncat(method, wblock->gblock.object_id, 2);
1064         result = get_subobj_info(device->handle, method, &info);
1065
1066         if (result) {
1067                 dev_warn(wmi_bus_dev,
1068                          "%s data block query control method not found\n",
1069                          method);
1070                 return result;
1071         }
1072
1073         wblock->dev.dev.type = &wmi_type_data;
1074
1075         /*
1076          * The Microsoft documentation specifically states:
1077          *
1078          *   Data blocks registered with only a single instance
1079          *   can ignore the parameter.
1080          *
1081          * ACPICA will get mad at us if we call the method with the wrong number
1082          * of arguments, so check what our method expects.  (On some Dell
1083          * laptops, WQxx may not be a method at all.)
1084          */
1085         if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1086                 wblock->read_takes_no_args = true;
1087
1088         kfree(info);
1089
1090         strcpy(method, "WS");
1091         strncat(method, wblock->gblock.object_id, 2);
1092         result = get_subobj_info(device->handle, method, NULL);
1093
1094         if (result == 0)
1095                 wblock->dev.setable = true;
1096
1097  out_init:
1098         wblock->dev.dev.bus = &wmi_bus_type;
1099         wblock->dev.dev.parent = wmi_bus_dev;
1100
1101         dev_set_name(&wblock->dev.dev, "%pUL", gblock->guid);
1102
1103         device_initialize(&wblock->dev.dev);
1104
1105         return 0;
1106 }
1107
1108 static void wmi_free_devices(struct acpi_device *device)
1109 {
1110         struct wmi_block *wblock, *next;
1111
1112         /* Delete devices for all the GUIDs */
1113         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1114                 if (wblock->acpi_device == device) {
1115                         list_del(&wblock->list);
1116                         device_unregister(&wblock->dev.dev);
1117                 }
1118         }
1119 }
1120
1121 static bool guid_already_parsed(struct acpi_device *device, const u8 *guid)
1122 {
1123         struct wmi_block *wblock;
1124
1125         list_for_each_entry(wblock, &wmi_block_list, list) {
1126                 if (memcmp(wblock->gblock.guid, guid, 16) == 0) {
1127                         /*
1128                          * Because we historically didn't track the relationship
1129                          * between GUIDs and ACPI nodes, we don't know whether
1130                          * we need to suppress GUIDs that are unique on a
1131                          * given node but duplicated across nodes.
1132                          */
1133                         dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
1134                                  guid, dev_name(&wblock->acpi_device->dev));
1135                         return true;
1136                 }
1137         }
1138
1139         return false;
1140 }
1141
1142 /*
1143  * Parse the _WDG method for the GUID data blocks
1144  */
1145 static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
1146 {
1147         struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1148         const struct guid_block *gblock;
1149         struct wmi_block *wblock, *next;
1150         union acpi_object *obj;
1151         acpi_status status;
1152         int retval = 0;
1153         u32 i, total;
1154
1155         status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1156         if (ACPI_FAILURE(status))
1157                 return -ENXIO;
1158
1159         obj = (union acpi_object *) out.pointer;
1160         if (!obj)
1161                 return -ENXIO;
1162
1163         if (obj->type != ACPI_TYPE_BUFFER) {
1164                 retval = -ENXIO;
1165                 goto out_free_pointer;
1166         }
1167
1168         gblock = (const struct guid_block *)obj->buffer.pointer;
1169         total = obj->buffer.length / sizeof(struct guid_block);
1170
1171         for (i = 0; i < total; i++) {
1172                 if (debug_dump_wdg)
1173                         wmi_dump_wdg(&gblock[i]);
1174
1175                 /*
1176                  * Some WMI devices, like those for nVidia hooks, have a
1177                  * duplicate GUID. It's not clear what we should do in this
1178                  * case yet, so for now, we'll just ignore the duplicate
1179                  * for device creation.
1180                  */
1181                 if (guid_already_parsed(device, gblock[i].guid))
1182                         continue;
1183
1184                 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
1185                 if (!wblock) {
1186                         retval = -ENOMEM;
1187                         break;
1188                 }
1189
1190                 wblock->acpi_device = device;
1191                 wblock->gblock = gblock[i];
1192
1193                 retval = wmi_create_device(wmi_bus_dev, &gblock[i], wblock, device);
1194                 if (retval) {
1195                         kfree(wblock);
1196                         continue;
1197                 }
1198
1199                 list_add_tail(&wblock->list, &wmi_block_list);
1200
1201                 if (debug_event) {
1202                         wblock->handler = wmi_notify_debug;
1203                         wmi_method_enable(wblock, 1);
1204                 }
1205         }
1206
1207         /*
1208          * Now that all of the devices are created, add them to the
1209          * device tree and probe subdrivers.
1210          */
1211         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1212                 if (wblock->acpi_device != device)
1213                         continue;
1214
1215                 retval = device_add(&wblock->dev.dev);
1216                 if (retval) {
1217                         dev_err(wmi_bus_dev, "failed to register %pUL\n",
1218                                 wblock->gblock.guid);
1219                         if (debug_event)
1220                                 wmi_method_enable(wblock, 0);
1221                         list_del(&wblock->list);
1222                         put_device(&wblock->dev.dev);
1223                 }
1224         }
1225
1226 out_free_pointer:
1227         kfree(out.pointer);
1228         return retval;
1229 }
1230
1231 /*
1232  * WMI can have EmbeddedControl access regions. In which case, we just want to
1233  * hand these off to the EC driver.
1234  */
1235 static acpi_status
1236 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1237                       u32 bits, u64 *value,
1238                       void *handler_context, void *region_context)
1239 {
1240         int result = 0, i = 0;
1241         u8 temp = 0;
1242
1243         if ((address > 0xFF) || !value)
1244                 return AE_BAD_PARAMETER;
1245
1246         if (function != ACPI_READ && function != ACPI_WRITE)
1247                 return AE_BAD_PARAMETER;
1248
1249         if (bits != 8)
1250                 return AE_BAD_PARAMETER;
1251
1252         if (function == ACPI_READ) {
1253                 result = ec_read(address, &temp);
1254                 (*value) |= ((u64)temp) << i;
1255         } else {
1256                 temp = 0xff & ((*value) >> i);
1257                 result = ec_write(address, temp);
1258         }
1259
1260         switch (result) {
1261         case -EINVAL:
1262                 return AE_BAD_PARAMETER;
1263                 break;
1264         case -ENODEV:
1265                 return AE_NOT_FOUND;
1266                 break;
1267         case -ETIME:
1268                 return AE_TIME;
1269                 break;
1270         default:
1271                 return AE_OK;
1272         }
1273 }
1274
1275 static void acpi_wmi_notify_handler(acpi_handle handle, u32 event,
1276                                     void *context)
1277 {
1278         struct guid_block *block;
1279         struct wmi_block *wblock;
1280         bool found_it = false;
1281
1282         list_for_each_entry(wblock, &wmi_block_list, list) {
1283                 block = &wblock->gblock;
1284
1285                 if (wblock->acpi_device->handle == handle &&
1286                     (block->flags & ACPI_WMI_EVENT) &&
1287                     (block->notify_id == event))
1288                 {
1289                         found_it = true;
1290                         break;
1291                 }
1292         }
1293
1294         if (!found_it)
1295                 return;
1296
1297         /* If a driver is bound, then notify the driver. */
1298         if (wblock->dev.dev.driver) {
1299                 struct wmi_driver *driver;
1300                 struct acpi_object_list input;
1301                 union acpi_object params[1];
1302                 struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL };
1303                 acpi_status status;
1304
1305                 driver = container_of(wblock->dev.dev.driver,
1306                                       struct wmi_driver, driver);
1307
1308                 input.count = 1;
1309                 input.pointer = params;
1310                 params[0].type = ACPI_TYPE_INTEGER;
1311                 params[0].integer.value = event;
1312
1313                 status = acpi_evaluate_object(wblock->acpi_device->handle,
1314                                               "_WED", &input, &evdata);
1315                 if (ACPI_FAILURE(status)) {
1316                         dev_warn(&wblock->dev.dev,
1317                                  "failed to get event data\n");
1318                         return;
1319                 }
1320
1321                 if (driver->notify)
1322                         driver->notify(&wblock->dev,
1323                                        (union acpi_object *)evdata.pointer);
1324
1325                 kfree(evdata.pointer);
1326         } else if (wblock->handler) {
1327                 /* Legacy handler */
1328                 wblock->handler(event, wblock->handler_data);
1329         }
1330
1331         if (debug_event)
1332                 pr_info("DEBUG Event GUID: %pUL\n", wblock->gblock.guid);
1333
1334         acpi_bus_generate_netlink_event(
1335                 wblock->acpi_device->pnp.device_class,
1336                 dev_name(&wblock->dev.dev),
1337                 event, 0);
1338
1339 }
1340
1341 static int acpi_wmi_remove(struct platform_device *device)
1342 {
1343         struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev);
1344
1345         acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1346                                    acpi_wmi_notify_handler);
1347         acpi_remove_address_space_handler(acpi_device->handle,
1348                                 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
1349         wmi_free_devices(acpi_device);
1350         device_destroy(&wmi_bus_class, MKDEV(0, 0));
1351
1352         return 0;
1353 }
1354
1355 static int acpi_wmi_probe(struct platform_device *device)
1356 {
1357         struct acpi_device *acpi_device;
1358         struct device *wmi_bus_dev;
1359         acpi_status status;
1360         int error;
1361
1362         acpi_device = ACPI_COMPANION(&device->dev);
1363         if (!acpi_device) {
1364                 dev_err(&device->dev, "ACPI companion is missing\n");
1365                 return -ENODEV;
1366         }
1367
1368         status = acpi_install_address_space_handler(acpi_device->handle,
1369                                                     ACPI_ADR_SPACE_EC,
1370                                                     &acpi_wmi_ec_space_handler,
1371                                                     NULL, NULL);
1372         if (ACPI_FAILURE(status)) {
1373                 dev_err(&device->dev, "Error installing EC region handler\n");
1374                 return -ENODEV;
1375         }
1376
1377         status = acpi_install_notify_handler(acpi_device->handle,
1378                                              ACPI_DEVICE_NOTIFY,
1379                                              acpi_wmi_notify_handler,
1380                                              NULL);
1381         if (ACPI_FAILURE(status)) {
1382                 dev_err(&device->dev, "Error installing notify handler\n");
1383                 error = -ENODEV;
1384                 goto err_remove_ec_handler;
1385         }
1386
1387         wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0),
1388                                     NULL, "wmi_bus-%s", dev_name(&device->dev));
1389         if (IS_ERR(wmi_bus_dev)) {
1390                 error = PTR_ERR(wmi_bus_dev);
1391                 goto err_remove_notify_handler;
1392         }
1393         dev_set_drvdata(&device->dev, wmi_bus_dev);
1394
1395         error = parse_wdg(wmi_bus_dev, acpi_device);
1396         if (error) {
1397                 pr_err("Failed to parse WDG method\n");
1398                 goto err_remove_busdev;
1399         }
1400
1401         return 0;
1402
1403 err_remove_busdev:
1404         device_destroy(&wmi_bus_class, MKDEV(0, 0));
1405
1406 err_remove_notify_handler:
1407         acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1408                                    acpi_wmi_notify_handler);
1409
1410 err_remove_ec_handler:
1411         acpi_remove_address_space_handler(acpi_device->handle,
1412                                           ACPI_ADR_SPACE_EC,
1413                                           &acpi_wmi_ec_space_handler);
1414
1415         return error;
1416 }
1417
1418 int __must_check __wmi_driver_register(struct wmi_driver *driver,
1419                                        struct module *owner)
1420 {
1421         driver->driver.owner = owner;
1422         driver->driver.bus = &wmi_bus_type;
1423
1424         return driver_register(&driver->driver);
1425 }
1426 EXPORT_SYMBOL(__wmi_driver_register);
1427
1428 void wmi_driver_unregister(struct wmi_driver *driver)
1429 {
1430         driver_unregister(&driver->driver);
1431 }
1432 EXPORT_SYMBOL(wmi_driver_unregister);
1433
1434 static int __init acpi_wmi_init(void)
1435 {
1436         int error;
1437
1438         if (acpi_disabled)
1439                 return -ENODEV;
1440
1441         error = class_register(&wmi_bus_class);
1442         if (error)
1443                 return error;
1444
1445         error = bus_register(&wmi_bus_type);
1446         if (error)
1447                 goto err_unreg_class;
1448
1449         error = platform_driver_register(&acpi_wmi_driver);
1450         if (error) {
1451                 pr_err("Error loading mapper\n");
1452                 goto err_unreg_bus;
1453         }
1454
1455         return 0;
1456
1457 err_unreg_bus:
1458         bus_unregister(&wmi_bus_type);
1459
1460 err_unreg_class:
1461         class_unregister(&wmi_bus_class);
1462
1463         return error;
1464 }
1465
1466 static void __exit acpi_wmi_exit(void)
1467 {
1468         platform_driver_unregister(&acpi_wmi_driver);
1469         bus_unregister(&wmi_bus_type);
1470         class_unregister(&wmi_bus_class);
1471 }
1472
1473 subsys_initcall_sync(acpi_wmi_init);
1474 module_exit(acpi_wmi_exit);