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 MODULE_AUTHOR("Carlos Corbacho");
  36 MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
  37 MODULE_LICENSE("GPL");
  38
  39 static LIST_HEAD(wmi_block_list);
  40
  41 struct guid_block {
  42         char guid[16];
  43         union {
  44                 char object_id[2];
  45                 struct {
  46                         unsigned char notify_id;
  47                         unsigned char reserved;
  48                 };
  49         };
  50         u8 instance_count;
  51         u8 flags;
  52 };
  53
  54 struct wmi_block {
  55         struct wmi_device dev;
  56         struct list_head list;
  57         struct guid_block gblock;
  58         struct miscdevice char_dev;
  59         struct mutex char_mutex;
  60         struct acpi_device *acpi_device;
  61         wmi_notify_handler handler;
  62         void *handler_data;
  63         u64 req_buf_size;
  64
  65         bool read_takes_no_args;
  66 };
  67
  68
  69 /*
  70  * If the GUID data block is marked as expensive, we must enable and
  71  * explicitily disable data collection.
  72  */
  73 #define ACPI_WMI_EXPENSIVE   0x1
  74 #define ACPI_WMI_METHOD      0x2        /* GUID is a method */
  75 #define ACPI_WMI_STRING      0x4        /* GUID takes & returns a string */
  76 #define ACPI_WMI_EVENT       0x8        /* GUID is an event */
  77
  78 static bool debug_event;
  79 module_param(debug_event, bool, 0444);
  80 MODULE_PARM_DESC(debug_event,
  81                  "Log WMI Events [0/1]");
  82
  83 static bool debug_dump_wdg;
  84 module_param(debug_dump_wdg, bool, 0444);
  85 MODULE_PARM_DESC(debug_dump_wdg,
  86                  "Dump available WMI interfaces [0/1]");
  87
  88 static int acpi_wmi_remove(struct platform_device *device);
  89 static int acpi_wmi_probe(struct platform_device *device);
  90
  91 static const struct acpi_device_id wmi_device_ids[] = {
  92         {"PNP0C14", 0},
  93         {"pnp0c14", 0},
  94         {"", 0},
  95 };
  96 MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
  97
  98 static struct platform_driver acpi_wmi_driver = {
  99         .driver = {
 100                 .name = "acpi-wmi",
 101                 .acpi_match_table = wmi_device_ids,
 102         },
 103         .probe = acpi_wmi_probe,
 104         .remove = acpi_wmi_remove,
 105 };
 106
 107 /*
 108  * GUID parsing functions
 109  */
 110
 111 static bool find_guid(const char *guid_string, struct wmi_block **out)
 112 {
 113         guid_t guid_input;
 114         struct wmi_block *wblock;
 115         struct guid_block *block;
 116
 117         if (guid_parse(guid_string, &guid_input))
 118                 return false;
 119
 120         list_for_each_entry(wblock, &wmi_block_list, list) {
 121                 block = &wblock->gblock;
 122
 123                 if (memcmp(block->guid, &guid_input, 16) == 0) {
 124                         if (out)
 125                                 *out = wblock;
 126                         return true;
 127                 }
 128         }
 129         return false;
 130 }
 131
 132 static const void *find_guid_context(struct wmi_block *wblock,
 133                                       struct wmi_driver *wdriver)
 134 {
 135         const struct wmi_device_id *id;
 136         guid_t guid_input;
 137
 138         if (wblock == NULL || wdriver == NULL)
 139                 return NULL;
 140         if (wdriver->id_table == NULL)
 141                 return NULL;
 142
 143         id = wdriver->id_table;
 144         while (*id->guid_string) {
 145                 if (guid_parse(id->guid_string, &guid_input))
 146                         continue;
 147                 if (!memcmp(wblock->gblock.guid, &guid_input, 16))
 148                         return id->context;
 149                 id++;
 150         }
 151         return NULL;
 152 }
 153
 154 static int get_subobj_info(acpi_handle handle, const char *pathname,
 155                            struct acpi_device_info **info)
 156 {
 157         struct acpi_device_info *dummy_info, **info_ptr;
 158         acpi_handle subobj_handle;
 159         acpi_status status;
 160
 161         status = acpi_get_handle(handle, (char *)pathname, &subobj_handle);
 162         if (status == AE_NOT_FOUND)
 163                 return -ENOENT;
 164         else if (ACPI_FAILURE(status))
 165                 return -EIO;
 166
 167         info_ptr = info ? info : &dummy_info;
 168         status = acpi_get_object_info(subobj_handle, info_ptr);
 169         if (ACPI_FAILURE(status))
 170                 return -EIO;
 171
 172         if (!info)
 173                 kfree(dummy_info);
 174
 175         return 0;
 176 }
 177
 178 static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable)
 179 {
 180         struct guid_block *block = NULL;
 181         char method[5];
 182         acpi_status status;
 183         acpi_handle handle;
 184
 185         block = &wblock->gblock;
 186         handle = wblock->acpi_device->handle;
 187
 188         snprintf(method, 5, "WE%02X", block->notify_id);
 189         status = acpi_execute_simple_method(handle, method, enable);
 190
 191         if (status != AE_OK && status != AE_NOT_FOUND)
 192                 return status;
 193         else
 194                 return AE_OK;
 195 }
 196
 197 /*
 198  * Exported WMI functions
 199  */
 200
 201 /**
 202  * set_required_buffer_size - Sets the buffer size needed for performing IOCTL
 203  * @wdev: A wmi bus device from a driver
 204  * @length: Required buffer size
 205  *
 206  * Allocates memory needed for buffer, stores the buffer size in that memory
 207  */
 208 int set_required_buffer_size(struct wmi_device *wdev, u64 length)
 209 {
 210         struct wmi_block *wblock;
 211
 212         wblock = container_of(wdev, struct wmi_block, dev);
 213         wblock->req_buf_size = length;
 214
 215         return 0;
 216 }
 217 EXPORT_SYMBOL_GPL(set_required_buffer_size);
 218
 219 /**
 220  * wmi_evaluate_method - Evaluate a WMI method
 221  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 222  * @instance: Instance index
 223  * @method_id: Method ID to call
 224  * @in: Buffer containing input for the method call
 225  * @out: Empty buffer to return the method results
 226  *
 227  * Call an ACPI-WMI method
 228  */
 229 acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
 230 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
 231 {
 232         struct wmi_block *wblock = NULL;
 233
 234         if (!find_guid(guid_string, &wblock))
 235                 return AE_ERROR;
 236         return wmidev_evaluate_method(&wblock->dev, instance, method_id,
 237                                       in, out);
 238 }
 239 EXPORT_SYMBOL_GPL(wmi_evaluate_method);
 240
 241 /**
 242  * wmidev_evaluate_method - Evaluate a WMI method
 243  * @wdev: A wmi bus device from a driver
 244  * @instance: Instance index
 245  * @method_id: Method ID to call
 246  * @in: Buffer containing input for the method call
 247  * @out: Empty buffer to return the method results
 248  *
 249  * Call an ACPI-WMI method
 250  */
 251 acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance,
 252         u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
 253 {
 254         struct guid_block *block = NULL;
 255         struct wmi_block *wblock = NULL;
 256         acpi_handle handle;
 257         acpi_status status;
 258         struct acpi_object_list input;
 259         union acpi_object params[3];
 260         char method[5] = "WM";
 261
 262         wblock = container_of(wdev, struct wmi_block, dev);
 263         block = &wblock->gblock;
 264         handle = wblock->acpi_device->handle;
 265
 266         if (!(block->flags & ACPI_WMI_METHOD))
 267                 return AE_BAD_DATA;
 268
 269         if (block->instance_count <= instance)
 270                 return AE_BAD_PARAMETER;
 271
 272         input.count = 2;
 273         input.pointer = params;
 274         params[0].type = ACPI_TYPE_INTEGER;
 275         params[0].integer.value = instance;
 276         params[1].type = ACPI_TYPE_INTEGER;
 277         params[1].integer.value = method_id;
 278
 279         if (in) {
 280                 input.count = 3;
 281
 282                 if (block->flags & ACPI_WMI_STRING) {
 283                         params[2].type = ACPI_TYPE_STRING;
 284                 } else {
 285                         params[2].type = ACPI_TYPE_BUFFER;
 286                 }
 287                 params[2].buffer.length = in->length;
 288                 params[2].buffer.pointer = in->pointer;
 289         }
 290
 291         strncat(method, block->object_id, 2);
 292
 293         status = acpi_evaluate_object(handle, method, &input, out);
 294
 295         return status;
 296 }
 297 EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
 298
 299 static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
 300                                  struct acpi_buffer *out)
 301 {
 302         struct guid_block *block = NULL;
 303         acpi_handle handle;
 304         acpi_status status, wc_status = AE_ERROR;
 305         struct acpi_object_list input;
 306         union acpi_object wq_params[1];
 307         char method[5];
 308         char wc_method[5] = "WC";
 309
 310         if (!out)
 311                 return AE_BAD_PARAMETER;
 312
 313         block = &wblock->gblock;
 314         handle = wblock->acpi_device->handle;
 315
 316         if (block->instance_count <= instance)
 317                 return AE_BAD_PARAMETER;
 318
 319         /* Check GUID is a data block */
 320         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 321                 return AE_ERROR;
 322
 323         input.count = 1;
 324         input.pointer = wq_params;
 325         wq_params[0].type = ACPI_TYPE_INTEGER;
 326         wq_params[0].integer.value = instance;
 327
 328         if (instance == 0 && wblock->read_takes_no_args)
 329                 input.count = 0;
 330
 331         /*
 332          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
 333          * enable collection.
 334          */
 335         if (block->flags & ACPI_WMI_EXPENSIVE) {
 336                 strncat(wc_method, block->object_id, 2);
 337
 338                 /*
 339                  * Some GUIDs break the specification by declaring themselves
 340                  * expensive, but have no corresponding WCxx method. So we
 341                  * should not fail if this happens.
 342                  */
 343                 wc_status = acpi_execute_simple_method(handle, wc_method, 1);
 344         }
 345
 346         strcpy(method, "WQ");
 347         strncat(method, block->object_id, 2);
 348
 349         status = acpi_evaluate_object(handle, method, &input, out);
 350
 351         /*
 352          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
 353          * the WQxx method failed - we should disable collection anyway.
 354          */
 355         if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
 356                 status = acpi_execute_simple_method(handle, wc_method, 0);
 357         }
 358
 359         return status;
 360 }
 361
 362 /**
 363  * wmi_query_block - Return contents of a WMI block (deprecated)
 364  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 365  * @instance: Instance index
 366  * @out: Empty buffer to return the contents of the data block to
 367  *
 368  * Return the contents of an ACPI-WMI data block to a buffer
 369  */
 370 acpi_status wmi_query_block(const char *guid_string, u8 instance,
 371                             struct acpi_buffer *out)
 372 {
 373         struct wmi_block *wblock;
 374
 375         if (!guid_string)
 376                 return AE_BAD_PARAMETER;
 377
 378         if (!find_guid(guid_string, &wblock))
 379                 return AE_ERROR;
 380
 381         return __query_block(wblock, instance, out);
 382 }
 383 EXPORT_SYMBOL_GPL(wmi_query_block);
 384
 385 union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
 386 {
 387         struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
 388         struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
 389
 390         if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
 391                 return NULL;
 392
 393         return (union acpi_object *)out.pointer;
 394 }
 395 EXPORT_SYMBOL_GPL(wmidev_block_query);
 396
 397 /**
 398  * wmi_set_block - Write to a WMI block
 399  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 400  * @instance: Instance index
 401  * @in: Buffer containing new values for the data block
 402  *
 403  * Write the contents of the input buffer to an ACPI-WMI data block
 404  */
 405 acpi_status wmi_set_block(const char *guid_string, u8 instance,
 406                           const struct acpi_buffer *in)
 407 {
 408         struct guid_block *block = NULL;
 409         struct wmi_block *wblock = NULL;
 410         acpi_handle handle;
 411         struct acpi_object_list input;
 412         union acpi_object params[2];
 413         char method[5] = "WS";
 414
 415         if (!guid_string || !in)
 416                 return AE_BAD_DATA;
 417
 418         if (!find_guid(guid_string, &wblock))
 419                 return AE_ERROR;
 420
 421         block = &wblock->gblock;
 422         handle = wblock->acpi_device->handle;
 423
 424         if (block->instance_count <= instance)
 425                 return AE_BAD_PARAMETER;
 426
 427         /* Check GUID is a data block */
 428         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 429                 return AE_ERROR;
 430
 431         input.count = 2;
 432         input.pointer = params;
 433         params[0].type = ACPI_TYPE_INTEGER;
 434         params[0].integer.value = instance;
 435
 436         if (block->flags & ACPI_WMI_STRING) {
 437                 params[1].type = ACPI_TYPE_STRING;
 438         } else {
 439                 params[1].type = ACPI_TYPE_BUFFER;
 440         }
 441         params[1].buffer.length = in->length;
 442         params[1].buffer.pointer = in->pointer;
 443
 444         strncat(method, block->object_id, 2);
 445
 446         return acpi_evaluate_object(handle, method, &input, NULL);
 447 }
 448 EXPORT_SYMBOL_GPL(wmi_set_block);
 449
 450 static void wmi_dump_wdg(const struct guid_block *g)
 451 {
 452         pr_info("%pUL:\n", g->guid);
 453         if (g->flags & ACPI_WMI_EVENT)
 454                 pr_info("\tnotify_id: 0x%02X\n", g->notify_id);
 455         else
 456                 pr_info("\tobject_id: %2pE\n", g->object_id);
 457         pr_info("\tinstance_count: %d\n", g->instance_count);
 458         pr_info("\tflags: %#x", g->flags);
 459         if (g->flags) {
 460                 if (g->flags & ACPI_WMI_EXPENSIVE)
 461                         pr_cont(" ACPI_WMI_EXPENSIVE");
 462                 if (g->flags & ACPI_WMI_METHOD)
 463                         pr_cont(" ACPI_WMI_METHOD");
 464                 if (g->flags & ACPI_WMI_STRING)
 465                         pr_cont(" ACPI_WMI_STRING");
 466                 if (g->flags & ACPI_WMI_EVENT)
 467                         pr_cont(" ACPI_WMI_EVENT");
 468         }
 469         pr_cont("\n");
 470
 471 }
 472
 473 static void wmi_notify_debug(u32 value, void *context)
 474 {
 475         struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
 476         union acpi_object *obj;
 477         acpi_status status;
 478
 479         status = wmi_get_event_data(value, &response);
 480         if (status != AE_OK) {
 481                 pr_info("bad event status 0x%x\n", status);
 482                 return;
 483         }
 484
 485         obj = (union acpi_object *)response.pointer;
 486
 487         if (!obj)
 488                 return;
 489
 490         pr_info("DEBUG Event ");
 491         switch(obj->type) {
 492         case ACPI_TYPE_BUFFER:
 493                 pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
 494                 break;
 495         case ACPI_TYPE_STRING:
 496                 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
 497                 break;
 498         case ACPI_TYPE_INTEGER:
 499                 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
 500                 break;
 501         case ACPI_TYPE_PACKAGE:
 502                 pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
 503                 break;
 504         default:
 505                 pr_cont("object type 0x%X\n", obj->type);
 506         }
 507         kfree(obj);
 508 }
 509
 510 /**
 511  * wmi_install_notify_handler - Register handler for WMI events
 512  * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 513  * @handler: Function to handle notifications
 514  * @data: Data to be returned to handler when event is fired
 515  *
 516  * Register a handler for events sent to the ACPI-WMI mapper device.
 517  */
 518 acpi_status wmi_install_notify_handler(const char *guid,
 519 wmi_notify_handler handler, void *data)
 520 {
 521         struct wmi_block *block;
 522         acpi_status status = AE_NOT_EXIST;
 523         guid_t guid_input;
 524
 525         if (!guid || !handler)
 526                 return AE_BAD_PARAMETER;
 527
 528         if (guid_parse(guid, &guid_input))
 529                 return AE_BAD_PARAMETER;
 530
 531         list_for_each_entry(block, &wmi_block_list, list) {
 532                 acpi_status wmi_status;
 533
 534                 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
 535                         if (block->handler &&
 536                             block->handler != wmi_notify_debug)
 537                                 return AE_ALREADY_ACQUIRED;
 538
 539                         block->handler = handler;
 540                         block->handler_data = data;
 541
 542                         wmi_status = wmi_method_enable(block, 1);
 543                         if ((wmi_status != AE_OK) ||
 544                             ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
 545                                 status = wmi_status;
 546                 }
 547         }
 548
 549         return status;
 550 }
 551 EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
 552
 553 /**
 554  * wmi_uninstall_notify_handler - Unregister handler for WMI events
 555  * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 556  *
 557  * Unregister handler for events sent to the ACPI-WMI mapper device.
 558  */
 559 acpi_status wmi_remove_notify_handler(const char *guid)
 560 {
 561         struct wmi_block *block;
 562         acpi_status status = AE_NOT_EXIST;
 563         guid_t guid_input;
 564
 565         if (!guid)
 566                 return AE_BAD_PARAMETER;
 567
 568         if (guid_parse(guid, &guid_input))
 569                 return AE_BAD_PARAMETER;
 570
 571         list_for_each_entry(block, &wmi_block_list, list) {
 572                 acpi_status wmi_status;
 573
 574                 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
 575                         if (!block->handler ||
 576                             block->handler == wmi_notify_debug)
 577                                 return AE_NULL_ENTRY;
 578
 579                         if (debug_event) {
 580                                 block->handler = wmi_notify_debug;
 581                                 status = AE_OK;
 582                         } else {
 583                                 wmi_status = wmi_method_enable(block, 0);
 584                                 block->handler = NULL;
 585                                 block->handler_data = NULL;
 586                                 if ((wmi_status != AE_OK) ||
 587                                     ((wmi_status == AE_OK) &&
 588                                      (status == AE_NOT_EXIST)))
 589                                         status = wmi_status;
 590                         }
 591                 }
 592         }
 593
 594         return status;
 595 }
 596 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
 597
 598 /**
 599  * wmi_get_event_data - Get WMI data associated with an event
 600  *
 601  * @event: Event to find
 602  * @out: Buffer to hold event data. out->pointer should be freed with kfree()
 603  *
 604  * Returns extra data associated with an event in WMI.
 605  */
 606 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
 607 {
 608         struct acpi_object_list input;
 609         union acpi_object params[1];
 610         struct guid_block *gblock;
 611         struct wmi_block *wblock;
 612
 613         input.count = 1;
 614         input.pointer = params;
 615         params[0].type = ACPI_TYPE_INTEGER;
 616         params[0].integer.value = event;
 617
 618         list_for_each_entry(wblock, &wmi_block_list, list) {
 619                 gblock = &wblock->gblock;
 620
 621                 if ((gblock->flags & ACPI_WMI_EVENT) &&
 622                         (gblock->notify_id == event))
 623                         return acpi_evaluate_object(wblock->acpi_device->handle,
 624                                 "_WED", &input, out);
 625         }
 626
 627         return AE_NOT_FOUND;
 628 }
 629 EXPORT_SYMBOL_GPL(wmi_get_event_data);
 630
 631 /**
 632  * wmi_has_guid - Check if a GUID is available
 633  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 634  *
 635  * Check if a given GUID is defined by _WDG
 636  */
 637 bool wmi_has_guid(const char *guid_string)
 638 {
 639         return find_guid(guid_string, NULL);
 640 }
 641 EXPORT_SYMBOL_GPL(wmi_has_guid);
 642
 643 /**
 644  * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID
 645  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 646  *
 647  * Find the _UID of ACPI device associated with this WMI GUID.
 648  *
 649  * Return: The ACPI _UID field value or NULL if the WMI GUID was not found
 650  */
 651 char *wmi_get_acpi_device_uid(const char *guid_string)
 652 {
 653         struct wmi_block *wblock = NULL;
 654
 655         if (!find_guid(guid_string, &wblock))
 656                 return NULL;
 657
 658         return acpi_device_uid(wblock->acpi_device);
 659 }
 660 EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
 661
 662 static struct wmi_block *dev_to_wblock(struct device *dev)
 663 {
 664         return container_of(dev, struct wmi_block, dev.dev);
 665 }
 666
 667 static struct wmi_device *dev_to_wdev(struct device *dev)
 668 {
 669         return container_of(dev, struct wmi_device, dev);
 670 }
 671
 672 /*
 673  * sysfs interface
 674  */
 675 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 676                              char *buf)
 677 {
 678         struct wmi_block *wblock = dev_to_wblock(dev);
 679
 680         return sprintf(buf, "wmi:%pUL\n", wblock->gblock.guid);
 681 }
 682 static DEVICE_ATTR_RO(modalias);
 683
 684 static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
 685                          char *buf)
 686 {
 687         struct wmi_block *wblock = dev_to_wblock(dev);
 688
 689         return sprintf(buf, "%pUL\n", wblock->gblock.guid);
 690 }
 691 static DEVICE_ATTR_RO(guid);
 692
 693 static ssize_t instance_count_show(struct device *dev,
 694                                    struct device_attribute *attr, char *buf)
 695 {
 696         struct wmi_block *wblock = dev_to_wblock(dev);
 697
 698         return sprintf(buf, "%d\n", (int)wblock->gblock.instance_count);
 699 }
 700 static DEVICE_ATTR_RO(instance_count);
 701
 702 static ssize_t expensive_show(struct device *dev,
 703                               struct device_attribute *attr, char *buf)
 704 {
 705         struct wmi_block *wblock = dev_to_wblock(dev);
 706
 707         return sprintf(buf, "%d\n",
 708                        (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
 709 }
 710 static DEVICE_ATTR_RO(expensive);
 711
 712 static struct attribute *wmi_attrs[] = {
 713         &dev_attr_modalias.attr,
 714         &dev_attr_guid.attr,
 715         &dev_attr_instance_count.attr,
 716         &dev_attr_expensive.attr,
 717         NULL,
 718 };
 719 ATTRIBUTE_GROUPS(wmi);
 720
 721 static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
 722                               char *buf)
 723 {
 724         struct wmi_block *wblock = dev_to_wblock(dev);
 725
 726         return sprintf(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
 727 }
 728 static DEVICE_ATTR_RO(notify_id);
 729
 730 static struct attribute *wmi_event_attrs[] = {
 731         &dev_attr_notify_id.attr,
 732         NULL,
 733 };
 734 ATTRIBUTE_GROUPS(wmi_event);
 735
 736 static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
 737                               char *buf)
 738 {
 739         struct wmi_block *wblock = dev_to_wblock(dev);
 740
 741         return sprintf(buf, "%c%c\n", wblock->gblock.object_id[0],
 742                        wblock->gblock.object_id[1]);
 743 }
 744 static DEVICE_ATTR_RO(object_id);
 745
 746 static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
 747                             char *buf)
 748 {
 749         struct wmi_device *wdev = dev_to_wdev(dev);
 750
 751         return sprintf(buf, "%d\n", (int)wdev->setable);
 752 }
 753 static DEVICE_ATTR_RO(setable);
 754
 755 static struct attribute *wmi_data_attrs[] = {
 756         &dev_attr_object_id.attr,
 757         &dev_attr_setable.attr,
 758         NULL,
 759 };
 760 ATTRIBUTE_GROUPS(wmi_data);
 761
 762 static struct attribute *wmi_method_attrs[] = {
 763         &dev_attr_object_id.attr,
 764         NULL,
 765 };
 766 ATTRIBUTE_GROUPS(wmi_method);
 767
 768 static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 769 {
 770         struct wmi_block *wblock = dev_to_wblock(dev);
 771
 772         if (add_uevent_var(env, "MODALIAS=wmi:%pUL", wblock->gblock.guid))
 773                 return -ENOMEM;
 774
 775         if (add_uevent_var(env, "WMI_GUID=%pUL", wblock->gblock.guid))
 776                 return -ENOMEM;
 777
 778         return 0;
 779 }
 780
 781 static void wmi_dev_release(struct device *dev)
 782 {
 783         struct wmi_block *wblock = dev_to_wblock(dev);
 784
 785         kfree(wblock);
 786 }
 787
 788 static int wmi_dev_match(struct device *dev, struct device_driver *driver)
 789 {
 790         struct wmi_driver *wmi_driver =
 791                 container_of(driver, struct wmi_driver, driver);
 792         struct wmi_block *wblock = dev_to_wblock(dev);
 793         const struct wmi_device_id *id = wmi_driver->id_table;
 794
 795         if (id == NULL)
 796                 return 0;
 797
 798         while (*id->guid_string) {
 799                 guid_t driver_guid;
 800
 801                 if (WARN_ON(guid_parse(id->guid_string, &driver_guid)))
 802                         continue;
 803                 if (!memcmp(&driver_guid, wblock->gblock.guid, 16))
 804                         return 1;
 805
 806                 id++;
 807         }
 808
 809         return 0;
 810 }
 811 static int wmi_char_open(struct inode *inode, struct file *filp)
 812 {
 813         const char *driver_name = filp->f_path.dentry->d_iname;
 814         struct wmi_block *wblock = NULL;
 815         struct wmi_block *next = NULL;
 816
 817         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
 818                 if (!wblock->dev.dev.driver)
 819                         continue;
 820                 if (strcmp(driver_name, wblock->dev.dev.driver->name) == 0) {
 821                         filp->private_data = wblock;
 822                         break;
 823                 }
 824         }
 825
 826         if (!filp->private_data)
 827                 return -ENODEV;
 828
 829         return nonseekable_open(inode, filp);
 830 }
 831
 832 static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
 833         size_t length, loff_t *offset)
 834 {
 835         struct wmi_block *wblock = filp->private_data;
 836
 837         return simple_read_from_buffer(buffer, length, offset,
 838                                        &wblock->req_buf_size,
 839                                        sizeof(wblock->req_buf_size));
 840 }
 841
 842 static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 843 {
 844         struct wmi_ioctl_buffer __user *input =
 845                 (struct wmi_ioctl_buffer __user *) arg;
 846         struct wmi_block *wblock = filp->private_data;
 847         struct wmi_ioctl_buffer *buf = NULL;
 848         struct wmi_driver *wdriver = NULL;
 849         int ret;
 850
 851         if (_IOC_TYPE(cmd) != WMI_IOC)
 852                 return -ENOTTY;
 853
 854         /* make sure we're not calling a higher instance than exists*/
 855         if (_IOC_NR(cmd) >= wblock->gblock.instance_count)
 856                 return -EINVAL;
 857
 858         mutex_lock(&wblock->char_mutex);
 859         buf = wblock->handler_data;
 860         if (get_user(buf->length, &input->length)) {
 861                 dev_dbg(&wblock->dev.dev, "Read length from user failed\n");
 862                 ret = -EFAULT;
 863                 goto out_ioctl;
 864         }
 865         /* if it's too small, abort */
 866         if (buf->length < wblock->req_buf_size) {
 867                 dev_err(&wblock->dev.dev,
 868                         "Buffer %lld too small, need at least %lld\n",
 869                         buf->length, wblock->req_buf_size);
 870                 ret = -EINVAL;
 871                 goto out_ioctl;
 872         }
 873         /* if it's too big, warn, driver will only use what is needed */
 874         if (buf->length > wblock->req_buf_size)
 875                 dev_warn(&wblock->dev.dev,
 876                         "Buffer %lld is bigger than required %lld\n",
 877                         buf->length, wblock->req_buf_size);
 878
 879         /* copy the structure from userspace */
 880         if (copy_from_user(buf, input, wblock->req_buf_size)) {
 881                 dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n",
 882                         wblock->req_buf_size);
 883                 ret = -EFAULT;
 884                 goto out_ioctl;
 885         }
 886
 887         /* let the driver do any filtering and do the call */
 888         wdriver = container_of(wblock->dev.dev.driver,
 889                                struct wmi_driver, driver);
 890         if (!try_module_get(wdriver->driver.owner)) {
 891                 ret = -EBUSY;
 892                 goto out_ioctl;
 893         }
 894         ret = wdriver->filter_callback(&wblock->dev, cmd, buf);
 895         module_put(wdriver->driver.owner);
 896         if (ret)
 897                 goto out_ioctl;
 898
 899         /* return the result (only up to our internal buffer size) */
 900         if (copy_to_user(input, buf, wblock->req_buf_size)) {
 901                 dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n",
 902                         wblock->req_buf_size);
 903                 ret = -EFAULT;
 904         }
 905
 906 out_ioctl:
 907         mutex_unlock(&wblock->char_mutex);
 908         return ret;
 909 }
 910
 911 static const struct file_operations wmi_fops = {
 912         .owner          = THIS_MODULE,
 913         .read           = wmi_char_read,
 914         .open           = wmi_char_open,
 915         .unlocked_ioctl = wmi_ioctl,
 916         .compat_ioctl   = compat_ptr_ioctl,
 917 };
 918
 919 static int wmi_dev_probe(struct device *dev)
 920 {
 921         struct wmi_block *wblock = dev_to_wblock(dev);
 922         struct wmi_driver *wdriver =
 923                 container_of(dev->driver, struct wmi_driver, driver);
 924         int ret = 0;
 925         char *buf;
 926
 927         if (ACPI_FAILURE(wmi_method_enable(wblock, 1)))
 928                 dev_warn(dev, "failed to enable device -- probing anyway\n");
 929
 930         if (wdriver->probe) {
 931                 ret = wdriver->probe(dev_to_wdev(dev),
 932                                 find_guid_context(wblock, wdriver));
 933                 if (ret != 0)
 934                         goto probe_failure;
 935         }
 936
 937         /* driver wants a character device made */
 938         if (wdriver->filter_callback) {
 939                 /* check that required buffer size declared by driver or MOF */
 940                 if (!wblock->req_buf_size) {
 941                         dev_err(&wblock->dev.dev,
 942                                 "Required buffer size not set\n");
 943                         ret = -EINVAL;
 944                         goto probe_failure;
 945                 }
 946
 947                 wblock->handler_data = kmalloc(wblock->req_buf_size,
 948                                                GFP_KERNEL);
 949                 if (!wblock->handler_data) {
 950                         ret = -ENOMEM;
 951                         goto probe_failure;
 952                 }
 953
 954                 buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name);
 955                 if (!buf) {
 956                         ret = -ENOMEM;
 957                         goto probe_string_failure;
 958                 }
 959                 wblock->char_dev.minor = MISC_DYNAMIC_MINOR;
 960                 wblock->char_dev.name = buf;
 961                 wblock->char_dev.fops = &wmi_fops;
 962                 wblock->char_dev.mode = 0444;
 963                 ret = misc_register(&wblock->char_dev);
 964                 if (ret) {
 965                         dev_warn(dev, "failed to register char dev: %d\n", ret);
 966                         ret = -ENOMEM;
 967                         goto probe_misc_failure;
 968                 }
 969         }
 970
 971         return 0;
 972
 973 probe_misc_failure:
 974         kfree(buf);
 975 probe_string_failure:
 976         kfree(wblock->handler_data);
 977 probe_failure:
 978         if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
 979                 dev_warn(dev, "failed to disable device\n");
 980         return ret;
 981 }
 982
 983 static void wmi_dev_remove(struct device *dev)
 984 {
 985         struct wmi_block *wblock = dev_to_wblock(dev);
 986         struct wmi_driver *wdriver =
 987                 container_of(dev->driver, struct wmi_driver, driver);
 988
 989         if (wdriver->filter_callback) {
 990                 misc_deregister(&wblock->char_dev);
 991                 kfree(wblock->char_dev.name);
 992                 kfree(wblock->handler_data);
 993         }
 994
 995         if (wdriver->remove)
 996                 wdriver->remove(dev_to_wdev(dev));
 997
 998         if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
 999                 dev_warn(dev, "failed to disable device\n");
1000 }
1001
1002 static struct class wmi_bus_class = {
1003         .name = "wmi_bus",
1004 };
1005
1006 static struct bus_type wmi_bus_type = {
1007         .name = "wmi",
1008         .dev_groups = wmi_groups,
1009         .match = wmi_dev_match,
1010         .uevent = wmi_dev_uevent,
1011         .probe = wmi_dev_probe,
1012         .remove = wmi_dev_remove,
1013 };
1014
1015 static const struct device_type wmi_type_event = {
1016         .name = "event",
1017         .groups = wmi_event_groups,
1018         .release = wmi_dev_release,
1019 };
1020
1021 static const struct device_type wmi_type_method = {
1022         .name = "method",
1023         .groups = wmi_method_groups,
1024         .release = wmi_dev_release,
1025 };
1026
1027 static const struct device_type wmi_type_data = {
1028         .name = "data",
1029         .groups = wmi_data_groups,
1030         .release = wmi_dev_release,
1031 };
1032
1033 static int wmi_create_device(struct device *wmi_bus_dev,
1034                              const struct guid_block *gblock,
1035                              struct wmi_block *wblock,
1036                              struct acpi_device *device)
1037 {
1038         struct acpi_device_info *info;
1039         char method[5];
1040         int result;
1041
1042         if (gblock->flags & ACPI_WMI_EVENT) {
1043                 wblock->dev.dev.type = &wmi_type_event;
1044                 goto out_init;
1045         }
1046
1047         if (gblock->flags & ACPI_WMI_METHOD) {
1048                 wblock->dev.dev.type = &wmi_type_method;
1049                 mutex_init(&wblock->char_mutex);
1050                 goto out_init;
1051         }
1052
1053         /*
1054          * Data Block Query Control Method (WQxx by convention) is
1055          * required per the WMI documentation. If it is not present,
1056          * we ignore this data block.
1057          */
1058         strcpy(method, "WQ");
1059         strncat(method, wblock->gblock.object_id, 2);
1060         result = get_subobj_info(device->handle, method, &info);
1061
1062         if (result) {
1063                 dev_warn(wmi_bus_dev,
1064                          "%s data block query control method not found\n",
1065                          method);
1066                 return result;
1067         }
1068
1069         wblock->dev.dev.type = &wmi_type_data;
1070
1071         /*
1072          * The Microsoft documentation specifically states:
1073          *
1074          *   Data blocks registered with only a single instance
1075          *   can ignore the parameter.
1076          *
1077          * ACPICA will get mad at us if we call the method with the wrong number
1078          * of arguments, so check what our method expects.  (On some Dell
1079          * laptops, WQxx may not be a method at all.)
1080          */
1081         if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1082                 wblock->read_takes_no_args = true;
1083
1084         kfree(info);
1085
1086         strcpy(method, "WS");
1087         strncat(method, wblock->gblock.object_id, 2);
1088         result = get_subobj_info(device->handle, method, NULL);
1089
1090         if (result == 0)
1091                 wblock->dev.setable = true;
1092
1093  out_init:
1094         wblock->dev.dev.bus = &wmi_bus_type;
1095         wblock->dev.dev.parent = wmi_bus_dev;
1096
1097         dev_set_name(&wblock->dev.dev, "%pUL", gblock->guid);
1098
1099         device_initialize(&wblock->dev.dev);
1100
1101         return 0;
1102 }
1103
1104 static void wmi_free_devices(struct acpi_device *device)
1105 {
1106         struct wmi_block *wblock, *next;
1107
1108         /* Delete devices for all the GUIDs */
1109         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1110                 if (wblock->acpi_device == device) {
1111                         list_del(&wblock->list);
1112                         device_unregister(&wblock->dev.dev);
1113                 }
1114         }
1115 }
1116
1117 static bool guid_already_parsed(struct acpi_device *device, const u8 *guid)
1118 {
1119         struct wmi_block *wblock;
1120
1121         list_for_each_entry(wblock, &wmi_block_list, list) {
1122                 if (memcmp(wblock->gblock.guid, guid, 16) == 0) {
1123                         /*
1124                          * Because we historically didn't track the relationship
1125                          * between GUIDs and ACPI nodes, we don't know whether
1126                          * we need to suppress GUIDs that are unique on a
1127                          * given node but duplicated across nodes.
1128                          */
1129                         dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
1130                                  guid, dev_name(&wblock->acpi_device->dev));
1131                         return true;
1132                 }
1133         }
1134
1135         return false;
1136 }
1137
1138 /*
1139  * Parse the _WDG method for the GUID data blocks
1140  */
1141 static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
1142 {
1143         struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1144         const struct guid_block *gblock;
1145         struct wmi_block *wblock, *next;
1146         union acpi_object *obj;
1147         acpi_status status;
1148         int retval = 0;
1149         u32 i, total;
1150
1151         status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1152         if (ACPI_FAILURE(status))
1153                 return -ENXIO;
1154
1155         obj = (union acpi_object *) out.pointer;
1156         if (!obj)
1157                 return -ENXIO;
1158
1159         if (obj->type != ACPI_TYPE_BUFFER) {
1160                 retval = -ENXIO;
1161                 goto out_free_pointer;
1162         }
1163
1164         gblock = (const struct guid_block *)obj->buffer.pointer;
1165         total = obj->buffer.length / sizeof(struct guid_block);
1166
1167         for (i = 0; i < total; i++) {
1168                 if (debug_dump_wdg)
1169                         wmi_dump_wdg(&gblock[i]);
1170
1171                 /*
1172                  * Some WMI devices, like those for nVidia hooks, have a
1173                  * duplicate GUID. It's not clear what we should do in this
1174                  * case yet, so for now, we'll just ignore the duplicate
1175                  * for device creation.
1176                  */
1177                 if (guid_already_parsed(device, gblock[i].guid))
1178                         continue;
1179
1180                 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
1181                 if (!wblock) {
1182                         retval = -ENOMEM;
1183                         break;
1184                 }
1185
1186                 wblock->acpi_device = device;
1187                 wblock->gblock = gblock[i];
1188
1189                 retval = wmi_create_device(wmi_bus_dev, &gblock[i], wblock, device);
1190                 if (retval) {
1191                         kfree(wblock);
1192                         continue;
1193                 }
1194
1195                 list_add_tail(&wblock->list, &wmi_block_list);
1196
1197                 if (debug_event) {
1198                         wblock->handler = wmi_notify_debug;
1199                         wmi_method_enable(wblock, 1);
1200                 }
1201         }
1202
1203         /*
1204          * Now that all of the devices are created, add them to the
1205          * device tree and probe subdrivers.
1206          */
1207         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1208                 if (wblock->acpi_device != device)
1209                         continue;
1210
1211                 retval = device_add(&wblock->dev.dev);
1212                 if (retval) {
1213                         dev_err(wmi_bus_dev, "failed to register %pUL\n",
1214                                 wblock->gblock.guid);
1215                         if (debug_event)
1216                                 wmi_method_enable(wblock, 0);
1217                         list_del(&wblock->list);
1218                         put_device(&wblock->dev.dev);
1219                 }
1220         }
1221
1222 out_free_pointer:
1223         kfree(out.pointer);
1224         return retval;
1225 }
1226
1227 /*
1228  * WMI can have EmbeddedControl access regions. In which case, we just want to
1229  * hand these off to the EC driver.
1230  */
1231 static acpi_status
1232 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1233                       u32 bits, u64 *value,
1234                       void *handler_context, void *region_context)
1235 {
1236         int result = 0, i = 0;
1237         u8 temp = 0;
1238
1239         if ((address > 0xFF) || !value)
1240                 return AE_BAD_PARAMETER;
1241
1242         if (function != ACPI_READ && function != ACPI_WRITE)
1243                 return AE_BAD_PARAMETER;
1244
1245         if (bits != 8)
1246                 return AE_BAD_PARAMETER;
1247
1248         if (function == ACPI_READ) {
1249                 result = ec_read(address, &temp);
1250                 (*value) |= ((u64)temp) << i;
1251         } else {
1252                 temp = 0xff & ((*value) >> i);
1253                 result = ec_write(address, temp);
1254         }
1255
1256         switch (result) {
1257         case -EINVAL:
1258                 return AE_BAD_PARAMETER;
1259         case -ENODEV:
1260                 return AE_NOT_FOUND;
1261         case -ETIME:
1262                 return AE_TIME;
1263         default:
1264                 return AE_OK;
1265         }
1266 }
1267
1268 static void acpi_wmi_notify_handler(acpi_handle handle, u32 event,
1269                                     void *context)
1270 {
1271         struct guid_block *block;
1272         struct wmi_block *wblock;
1273         bool found_it = false;
1274
1275         list_for_each_entry(wblock, &wmi_block_list, list) {
1276                 block = &wblock->gblock;
1277
1278                 if (wblock->acpi_device->handle == handle &&
1279                     (block->flags & ACPI_WMI_EVENT) &&
1280                     (block->notify_id == event))
1281                 {
1282                         found_it = true;
1283                         break;
1284                 }
1285         }
1286
1287         if (!found_it)
1288                 return;
1289
1290         /* If a driver is bound, then notify the driver. */
1291         if (wblock->dev.dev.driver) {
1292                 struct wmi_driver *driver;
1293                 struct acpi_object_list input;
1294                 union acpi_object params[1];
1295                 struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL };
1296                 acpi_status status;
1297
1298                 driver = container_of(wblock->dev.dev.driver,
1299                                       struct wmi_driver, driver);
1300
1301                 input.count = 1;
1302                 input.pointer = params;
1303                 params[0].type = ACPI_TYPE_INTEGER;
1304                 params[0].integer.value = event;
1305
1306                 status = acpi_evaluate_object(wblock->acpi_device->handle,
1307                                               "_WED", &input, &evdata);
1308                 if (ACPI_FAILURE(status)) {
1309                         dev_warn(&wblock->dev.dev,
1310                                  "failed to get event data\n");
1311                         return;
1312                 }
1313
1314                 if (driver->notify)
1315                         driver->notify(&wblock->dev,
1316                                        (union acpi_object *)evdata.pointer);
1317
1318                 kfree(evdata.pointer);
1319         } else if (wblock->handler) {
1320                 /* Legacy handler */
1321                 wblock->handler(event, wblock->handler_data);
1322         }
1323
1324         if (debug_event)
1325                 pr_info("DEBUG Event GUID: %pUL\n", wblock->gblock.guid);
1326
1327         acpi_bus_generate_netlink_event(
1328                 wblock->acpi_device->pnp.device_class,
1329                 dev_name(&wblock->dev.dev),
1330                 event, 0);
1331
1332 }
1333
1334 static int acpi_wmi_remove(struct platform_device *device)
1335 {
1336         struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev);
1337
1338         acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1339                                    acpi_wmi_notify_handler);
1340         acpi_remove_address_space_handler(acpi_device->handle,
1341                                 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
1342         wmi_free_devices(acpi_device);
1343         device_unregister((struct device *)dev_get_drvdata(&device->dev));
1344
1345         return 0;
1346 }
1347
1348 static int acpi_wmi_probe(struct platform_device *device)
1349 {
1350         struct acpi_device *acpi_device;
1351         struct device *wmi_bus_dev;
1352         acpi_status status;
1353         int error;
1354
1355         acpi_device = ACPI_COMPANION(&device->dev);
1356         if (!acpi_device) {
1357                 dev_err(&device->dev, "ACPI companion is missing\n");
1358                 return -ENODEV;
1359         }
1360
1361         status = acpi_install_address_space_handler(acpi_device->handle,
1362                                                     ACPI_ADR_SPACE_EC,
1363                                                     &acpi_wmi_ec_space_handler,
1364                                                     NULL, NULL);
1365         if (ACPI_FAILURE(status)) {
1366                 dev_err(&device->dev, "Error installing EC region handler\n");
1367                 return -ENODEV;
1368         }
1369
1370         status = acpi_install_notify_handler(acpi_device->handle,
1371                                              ACPI_DEVICE_NOTIFY,
1372                                              acpi_wmi_notify_handler,
1373                                              NULL);
1374         if (ACPI_FAILURE(status)) {
1375                 dev_err(&device->dev, "Error installing notify handler\n");
1376                 error = -ENODEV;
1377                 goto err_remove_ec_handler;
1378         }
1379
1380         wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0),
1381                                     NULL, "wmi_bus-%s", dev_name(&device->dev));
1382         if (IS_ERR(wmi_bus_dev)) {
1383                 error = PTR_ERR(wmi_bus_dev);
1384                 goto err_remove_notify_handler;
1385         }
1386         dev_set_drvdata(&device->dev, wmi_bus_dev);
1387
1388         error = parse_wdg(wmi_bus_dev, acpi_device);
1389         if (error) {
1390                 pr_err("Failed to parse WDG method\n");
1391                 goto err_remove_busdev;
1392         }
1393
1394         return 0;
1395
1396 err_remove_busdev:
1397         device_unregister(wmi_bus_dev);
1398
1399 err_remove_notify_handler:
1400         acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1401                                    acpi_wmi_notify_handler);
1402
1403 err_remove_ec_handler:
1404         acpi_remove_address_space_handler(acpi_device->handle,
1405                                           ACPI_ADR_SPACE_EC,
1406                                           &acpi_wmi_ec_space_handler);
1407
1408         return error;
1409 }
1410
1411 int __must_check __wmi_driver_register(struct wmi_driver *driver,
1412                                        struct module *owner)
1413 {
1414         driver->driver.owner = owner;
1415         driver->driver.bus = &wmi_bus_type;
1416
1417         return driver_register(&driver->driver);
1418 }
1419 EXPORT_SYMBOL(__wmi_driver_register);
1420
1421 void wmi_driver_unregister(struct wmi_driver *driver)
1422 {
1423         driver_unregister(&driver->driver);
1424 }
1425 EXPORT_SYMBOL(wmi_driver_unregister);
1426
1427 static int __init acpi_wmi_init(void)
1428 {
1429         int error;
1430
1431         if (acpi_disabled)
1432                 return -ENODEV;
1433
1434         error = class_register(&wmi_bus_class);
1435         if (error)
1436                 return error;
1437
1438         error = bus_register(&wmi_bus_type);
1439         if (error)
1440                 goto err_unreg_class;
1441
1442         error = platform_driver_register(&acpi_wmi_driver);
1443         if (error) {
1444                 pr_err("Error loading mapper\n");
1445                 goto err_unreg_bus;
1446         }
1447
1448         return 0;
1449
1450 err_unreg_bus:
1451         bus_unregister(&wmi_bus_type);
1452
1453 err_unreg_class:
1454         class_unregister(&wmi_bus_class);
1455
1456         return error;
1457 }
1458
1459 static void __exit acpi_wmi_exit(void)
1460 {
1461         platform_driver_unregister(&acpi_wmi_driver);
1462         bus_unregister(&wmi_bus_type);
1463         class_unregister(&wmi_bus_class);
1464 }
1465
1466 subsys_initcall_sync(acpi_wmi_init);
1467 module_exit(acpi_wmi_exit);