drivers/platform/x86/wmi.c

   1 /*
   2  *  ACPI-WMI mapping driver
   3  *
   4  *  Copyright (C) 2007-2008 Carlos Corbacho <carlos@strangeworlds.co.uk>
   5  *
   6  *  GUID parsing code from ldm.c is:
   7  *   Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
   8  *   Copyright (c) 2001-2007 Anton Altaparmakov
   9  *   Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
  10  *
  11  *  WMI bus infrastructure by Andrew Lutomirski and Darren Hart:
  12  *    Copyright (C) 2015 Andrew Lutomirski
  13  *    Copyright (C) 2017 VMware, Inc. All Rights Reserved.
  14  *
  15  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  16  *
  17  *  This program is free software; you can redistribute it and/or modify
  18  *  it under the terms of the GNU General Public License as published by
  19  *  the Free Software Foundation; either version 2 of the License, or (at
  20  *  your option) any later version.
  21  *
  22  *  This program is distributed in the hope that it will be useful, but
  23  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  24  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  25  *  General Public License for more details.
  26  *
  27  *  You should have received a copy of the GNU General Public License along
  28  *  with this program; if not, write to the Free Software Foundation, Inc.,
  29  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  30  *
  31  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  32  */
  33
  34 #define pr_fmt(fmt)     KBUILD_MODNAME ": " fmt
  35
  36 #include <linux/acpi.h>
  37 #include <linux/device.h>
  38 #include <linux/init.h>
  39 #include <linux/kernel.h>
  40 #include <linux/list.h>
  41 #include <linux/miscdevice.h>
  42 #include <linux/module.h>
  43 #include <linux/platform_device.h>
  44 #include <linux/slab.h>
  45 #include <linux/types.h>
  46 #include <linux/uaccess.h>
  47 #include <linux/uuid.h>
  48 #include <linux/wmi.h>
  49 #include <uapi/linux/wmi.h>
  50
  51 ACPI_MODULE_NAME("wmi");
  52 MODULE_AUTHOR("Carlos Corbacho");
  53 MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
  54 MODULE_LICENSE("GPL");
  55
  56 static LIST_HEAD(wmi_block_list);
  57
  58 struct guid_block {
  59         char guid[16];
  60         union {
  61                 char object_id[2];
  62                 struct {
  63                         unsigned char notify_id;
  64                         unsigned char reserved;
  65                 };
  66         };
  67         u8 instance_count;
  68         u8 flags;
  69 };
  70
  71 struct wmi_block {
  72         struct wmi_device dev;
  73         struct list_head list;
  74         struct guid_block gblock;
  75         struct miscdevice char_dev;
  76         struct mutex char_mutex;
  77         struct acpi_device *acpi_device;
  78         wmi_notify_handler handler;
  79         void *handler_data;
  80         u64 req_buf_size;
  81
  82         bool read_takes_no_args;
  83 };
  84
  85
  86 /*
  87  * If the GUID data block is marked as expensive, we must enable and
  88  * explicitily disable data collection.
  89  */
  90 #define ACPI_WMI_EXPENSIVE   0x1
  91 #define ACPI_WMI_METHOD      0x2        /* GUID is a method */
  92 #define ACPI_WMI_STRING      0x4        /* GUID takes & returns a string */
  93 #define ACPI_WMI_EVENT       0x8        /* GUID is an event */
  94
  95 static bool debug_event;
  96 module_param(debug_event, bool, 0444);
  97 MODULE_PARM_DESC(debug_event,
  98                  "Log WMI Events [0/1]");
  99
 100 static bool debug_dump_wdg;
 101 module_param(debug_dump_wdg, bool, 0444);
 102 MODULE_PARM_DESC(debug_dump_wdg,
 103                  "Dump available WMI interfaces [0/1]");
 104
 105 static int acpi_wmi_remove(struct platform_device *device);
 106 static int acpi_wmi_probe(struct platform_device *device);
 107
 108 static const struct acpi_device_id wmi_device_ids[] = {
 109         {"PNP0C14", 0},
 110         {"pnp0c14", 0},
 111         {"", 0},
 112 };
 113 MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
 114
 115 static struct platform_driver acpi_wmi_driver = {
 116         .driver = {
 117                 .name = "acpi-wmi",
 118                 .acpi_match_table = wmi_device_ids,
 119         },
 120         .probe = acpi_wmi_probe,
 121         .remove = acpi_wmi_remove,
 122 };
 123
 124 /*
 125  * GUID parsing functions
 126  */
 127
 128 static bool find_guid(const char *guid_string, struct wmi_block **out)
 129 {
 130         uuid_le guid_input;
 131         struct wmi_block *wblock;
 132         struct guid_block *block;
 133
 134         if (uuid_le_to_bin(guid_string, &guid_input))
 135                 return false;
 136
 137         list_for_each_entry(wblock, &wmi_block_list, list) {
 138                 block = &wblock->gblock;
 139
 140                 if (memcmp(block->guid, &guid_input, 16) == 0) {
 141                         if (out)
 142                                 *out = wblock;
 143                         return true;
 144                 }
 145         }
 146         return false;
 147 }
 148
 149 static int get_subobj_info(acpi_handle handle, const char *pathname,
 150                            struct acpi_device_info **info)
 151 {
 152         struct acpi_device_info *dummy_info, **info_ptr;
 153         acpi_handle subobj_handle;
 154         acpi_status status;
 155
 156         status = acpi_get_handle(handle, (char *)pathname, &subobj_handle);
 157         if (status == AE_NOT_FOUND)
 158                 return -ENOENT;
 159         else if (ACPI_FAILURE(status))
 160                 return -EIO;
 161
 162         info_ptr = info ? info : &dummy_info;
 163         status = acpi_get_object_info(subobj_handle, info_ptr);
 164         if (ACPI_FAILURE(status))
 165                 return -EIO;
 166
 167         if (!info)
 168                 kfree(dummy_info);
 169
 170         return 0;
 171 }
 172
 173 static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable)
 174 {
 175         struct guid_block *block = NULL;
 176         char method[5];
 177         acpi_status status;
 178         acpi_handle handle;
 179
 180         block = &wblock->gblock;
 181         handle = wblock->acpi_device->handle;
 182
 183         snprintf(method, 5, "WE%02X", block->notify_id);
 184         status = acpi_execute_simple_method(handle, method, enable);
 185
 186         if (status != AE_OK && status != AE_NOT_FOUND)
 187                 return status;
 188         else
 189                 return AE_OK;
 190 }
 191
 192 /*
 193  * Exported WMI functions
 194  */
 195
 196 /**
 197  * set_required_buffer_size - Sets the buffer size needed for performing IOCTL
 198  * @wdev: A wmi bus device from a driver
 199  * @instance: Instance index
 200  *
 201  * Allocates memory needed for buffer, stores the buffer size in that memory
 202  */
 203 int set_required_buffer_size(struct wmi_device *wdev, u64 length)
 204 {
 205         struct wmi_block *wblock;
 206
 207         wblock = container_of(wdev, struct wmi_block, dev);
 208         wblock->req_buf_size = length;
 209
 210         return 0;
 211 }
 212 EXPORT_SYMBOL_GPL(set_required_buffer_size);
 213
 214 /**
 215  * wmi_evaluate_method - Evaluate a WMI method
 216  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 217  * @instance: Instance index
 218  * @method_id: Method ID to call
 219  * &in: Buffer containing input for the method call
 220  * &out: Empty buffer to return the method results
 221  *
 222  * Call an ACPI-WMI method
 223  */
 224 acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
 225 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
 226 {
 227         struct wmi_block *wblock = NULL;
 228
 229         if (!find_guid(guid_string, &wblock))
 230                 return AE_ERROR;
 231         return wmidev_evaluate_method(&wblock->dev, instance, method_id,
 232                                       in, out);
 233 }
 234 EXPORT_SYMBOL_GPL(wmi_evaluate_method);
 235
 236 /**
 237  * wmidev_evaluate_method - Evaluate a WMI method
 238  * @wdev: A wmi bus device from a driver
 239  * @instance: Instance index
 240  * @method_id: Method ID to call
 241  * &in: Buffer containing input for the method call
 242  * &out: Empty buffer to return the method results
 243  *
 244  * Call an ACPI-WMI method
 245  */
 246 acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance,
 247         u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
 248 {
 249         struct guid_block *block = NULL;
 250         struct wmi_block *wblock = NULL;
 251         acpi_handle handle;
 252         acpi_status status;
 253         struct acpi_object_list input;
 254         union acpi_object params[3];
 255         char method[5] = "WM";
 256
 257         wblock = container_of(wdev, struct wmi_block, dev);
 258         block = &wblock->gblock;
 259         handle = wblock->acpi_device->handle;
 260
 261         if (!(block->flags & ACPI_WMI_METHOD))
 262                 return AE_BAD_DATA;
 263
 264         if (block->instance_count <= instance)
 265                 return AE_BAD_PARAMETER;
 266
 267         input.count = 2;
 268         input.pointer = params;
 269         params[0].type = ACPI_TYPE_INTEGER;
 270         params[0].integer.value = instance;
 271         params[1].type = ACPI_TYPE_INTEGER;
 272         params[1].integer.value = method_id;
 273
 274         if (in) {
 275                 input.count = 3;
 276
 277                 if (block->flags & ACPI_WMI_STRING) {
 278                         params[2].type = ACPI_TYPE_STRING;
 279                 } else {
 280                         params[2].type = ACPI_TYPE_BUFFER;
 281                 }
 282                 params[2].buffer.length = in->length;
 283                 params[2].buffer.pointer = in->pointer;
 284         }
 285
 286         strncat(method, block->object_id, 2);
 287
 288         status = acpi_evaluate_object(handle, method, &input, out);
 289
 290         return status;
 291 }
 292 EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
 293
 294 static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
 295                                  struct acpi_buffer *out)
 296 {
 297         struct guid_block *block = NULL;
 298         acpi_handle handle;
 299         acpi_status status, wc_status = AE_ERROR;
 300         struct acpi_object_list input;
 301         union acpi_object wq_params[1];
 302         char method[5];
 303         char wc_method[5] = "WC";
 304
 305         if (!out)
 306                 return AE_BAD_PARAMETER;
 307
 308         block = &wblock->gblock;
 309         handle = wblock->acpi_device->handle;
 310
 311         if (block->instance_count <= instance)
 312                 return AE_BAD_PARAMETER;
 313
 314         /* Check GUID is a data block */
 315         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 316                 return AE_ERROR;
 317
 318         input.count = 1;
 319         input.pointer = wq_params;
 320         wq_params[0].type = ACPI_TYPE_INTEGER;
 321         wq_params[0].integer.value = instance;
 322
 323         if (instance == 0 && wblock->read_takes_no_args)
 324                 input.count = 0;
 325
 326         /*
 327          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
 328          * enable collection.
 329          */
 330         if (block->flags & ACPI_WMI_EXPENSIVE) {
 331                 strncat(wc_method, block->object_id, 2);
 332
 333                 /*
 334                  * Some GUIDs break the specification by declaring themselves
 335                  * expensive, but have no corresponding WCxx method. So we
 336                  * should not fail if this happens.
 337                  */
 338                 if (acpi_has_method(handle, wc_method))
 339                         wc_status = acpi_execute_simple_method(handle,
 340                                                                 wc_method, 1);
 341         }
 342
 343         strcpy(method, "WQ");
 344         strncat(method, block->object_id, 2);
 345
 346         status = acpi_evaluate_object(handle, method, &input, out);
 347
 348         /*
 349          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
 350          * the WQxx method failed - we should disable collection anyway.
 351          */
 352         if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
 353                 status = acpi_execute_simple_method(handle, wc_method, 0);
 354         }
 355
 356         return status;
 357 }
 358
 359 /**
 360  * wmi_query_block - Return contents of a WMI block (deprecated)
 361  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 362  * @instance: Instance index
 363  * &out: Empty buffer to return the contents of the data block to
 364  *
 365  * Return the contents of an ACPI-WMI data block to a buffer
 366  */
 367 acpi_status wmi_query_block(const char *guid_string, u8 instance,
 368                             struct acpi_buffer *out)
 369 {
 370         struct wmi_block *wblock;
 371
 372         if (!guid_string)
 373                 return AE_BAD_PARAMETER;
 374
 375         if (!find_guid(guid_string, &wblock))
 376                 return AE_ERROR;
 377
 378         return __query_block(wblock, instance, out);
 379 }
 380 EXPORT_SYMBOL_GPL(wmi_query_block);
 381
 382 union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
 383 {
 384         struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
 385         struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
 386
 387         if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
 388                 return NULL;
 389
 390         return (union acpi_object *)out.pointer;
 391 }
 392 EXPORT_SYMBOL_GPL(wmidev_block_query);
 393
 394 /**
 395  * wmi_set_block - Write to a WMI block
 396  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 397  * @instance: Instance index
 398  * &in: Buffer containing new values for the data block
 399  *
 400  * Write the contents of the input buffer to an ACPI-WMI data block
 401  */
 402 acpi_status wmi_set_block(const char *guid_string, u8 instance,
 403                           const struct acpi_buffer *in)
 404 {
 405         struct guid_block *block = NULL;
 406         struct wmi_block *wblock = NULL;
 407         acpi_handle handle;
 408         struct acpi_object_list input;
 409         union acpi_object params[2];
 410         char method[5] = "WS";
 411
 412         if (!guid_string || !in)
 413                 return AE_BAD_DATA;
 414
 415         if (!find_guid(guid_string, &wblock))
 416                 return AE_ERROR;
 417
 418         block = &wblock->gblock;
 419         handle = wblock->acpi_device->handle;
 420
 421         if (block->instance_count <= instance)
 422                 return AE_BAD_PARAMETER;
 423
 424         /* Check GUID is a data block */
 425         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 426                 return AE_ERROR;
 427
 428         input.count = 2;
 429         input.pointer = params;
 430         params[0].type = ACPI_TYPE_INTEGER;
 431         params[0].integer.value = instance;
 432
 433         if (block->flags & ACPI_WMI_STRING) {
 434                 params[1].type = ACPI_TYPE_STRING;
 435         } else {
 436                 params[1].type = ACPI_TYPE_BUFFER;
 437         }
 438         params[1].buffer.length = in->length;
 439         params[1].buffer.pointer = in->pointer;
 440
 441         strncat(method, block->object_id, 2);
 442
 443         return acpi_evaluate_object(handle, method, &input, NULL);
 444 }
 445 EXPORT_SYMBOL_GPL(wmi_set_block);
 446
 447 static void wmi_dump_wdg(const struct guid_block *g)
 448 {
 449         pr_info("%pUL:\n", g->guid);
 450         if (g->flags & ACPI_WMI_EVENT)
 451                 pr_info("\tnotify_id: 0x%02X\n", g->notify_id);
 452         else
 453                 pr_info("\tobject_id: %2pE\n", g->object_id);
 454         pr_info("\tinstance_count: %d\n", g->instance_count);
 455         pr_info("\tflags: %#x", g->flags);
 456         if (g->flags) {
 457                 if (g->flags & ACPI_WMI_EXPENSIVE)
 458                         pr_cont(" ACPI_WMI_EXPENSIVE");
 459                 if (g->flags & ACPI_WMI_METHOD)
 460                         pr_cont(" ACPI_WMI_METHOD");
 461                 if (g->flags & ACPI_WMI_STRING)
 462                         pr_cont(" ACPI_WMI_STRING");
 463                 if (g->flags & ACPI_WMI_EVENT)
 464                         pr_cont(" ACPI_WMI_EVENT");
 465         }
 466         pr_cont("\n");
 467
 468 }
 469
 470 static void wmi_notify_debug(u32 value, void *context)
 471 {
 472         struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
 473         union acpi_object *obj;
 474         acpi_status status;
 475
 476         status = wmi_get_event_data(value, &response);
 477         if (status != AE_OK) {
 478                 pr_info("bad event status 0x%x\n", status);
 479                 return;
 480         }
 481
 482         obj = (union acpi_object *)response.pointer;
 483
 484         if (!obj)
 485                 return;
 486
 487         pr_info("DEBUG Event ");
 488         switch(obj->type) {
 489         case ACPI_TYPE_BUFFER:
 490                 pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
 491                 break;
 492         case ACPI_TYPE_STRING:
 493                 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
 494                 break;
 495         case ACPI_TYPE_INTEGER:
 496                 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
 497                 break;
 498         case ACPI_TYPE_PACKAGE:
 499                 pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
 500                 break;
 501         default:
 502                 pr_cont("object type 0x%X\n", obj->type);
 503         }
 504         kfree(obj);
 505 }
 506
 507 /**
 508  * wmi_install_notify_handler - Register handler for WMI events
 509  * @handler: Function to handle notifications
 510  * @data: Data to be returned to handler when event is fired
 511  *
 512  * Register a handler for events sent to the ACPI-WMI mapper device.
 513  */
 514 acpi_status wmi_install_notify_handler(const char *guid,
 515 wmi_notify_handler handler, void *data)
 516 {
 517         struct wmi_block *block;
 518         acpi_status status = AE_NOT_EXIST;
 519         uuid_le guid_input;
 520
 521         if (!guid || !handler)
 522                 return AE_BAD_PARAMETER;
 523
 524         if (uuid_le_to_bin(guid, &guid_input))
 525                 return AE_BAD_PARAMETER;
 526
 527         list_for_each_entry(block, &wmi_block_list, list) {
 528                 acpi_status wmi_status;
 529
 530                 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
 531                         if (block->handler &&
 532                             block->handler != wmi_notify_debug)
 533                                 return AE_ALREADY_ACQUIRED;
 534
 535                         block->handler = handler;
 536                         block->handler_data = data;
 537
 538                         wmi_status = wmi_method_enable(block, 1);
 539                         if ((wmi_status != AE_OK) ||
 540                             ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
 541                                 status = wmi_status;
 542                 }
 543         }
 544
 545         return status;
 546 }
 547 EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
 548
 549 /**
 550  * wmi_uninstall_notify_handler - Unregister handler for WMI events
 551  *
 552  * Unregister handler for events sent to the ACPI-WMI mapper device.
 553  */
 554 acpi_status wmi_remove_notify_handler(const char *guid)
 555 {
 556         struct wmi_block *block;
 557         acpi_status status = AE_NOT_EXIST;
 558         uuid_le guid_input;
 559
 560         if (!guid)
 561                 return AE_BAD_PARAMETER;
 562
 563         if (uuid_le_to_bin(guid, &guid_input))
 564                 return AE_BAD_PARAMETER;
 565
 566         list_for_each_entry(block, &wmi_block_list, list) {
 567                 acpi_status wmi_status;
 568
 569                 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
 570                         if (!block->handler ||
 571                             block->handler == wmi_notify_debug)
 572                                 return AE_NULL_ENTRY;
 573
 574                         if (debug_event) {
 575                                 block->handler = wmi_notify_debug;
 576                                 status = AE_OK;
 577                         } else {
 578                                 wmi_status = wmi_method_enable(block, 0);
 579                                 block->handler = NULL;
 580                                 block->handler_data = NULL;
 581                                 if ((wmi_status != AE_OK) ||
 582                                     ((wmi_status == AE_OK) &&
 583                                      (status == AE_NOT_EXIST)))
 584                                         status = wmi_status;
 585                         }
 586                 }
 587         }
 588
 589         return status;
 590 }
 591 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
 592
 593 /**
 594  * wmi_get_event_data - Get WMI data associated with an event
 595  *
 596  * @event: Event to find
 597  * @out: Buffer to hold event data. out->pointer should be freed with kfree()
 598  *
 599  * Returns extra data associated with an event in WMI.
 600  */
 601 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
 602 {
 603         struct acpi_object_list input;
 604         union acpi_object params[1];
 605         struct guid_block *gblock;
 606         struct wmi_block *wblock;
 607
 608         input.count = 1;
 609         input.pointer = params;
 610         params[0].type = ACPI_TYPE_INTEGER;
 611         params[0].integer.value = event;
 612
 613         list_for_each_entry(wblock, &wmi_block_list, list) {
 614                 gblock = &wblock->gblock;
 615
 616                 if ((gblock->flags & ACPI_WMI_EVENT) &&
 617                         (gblock->notify_id == event))
 618                         return acpi_evaluate_object(wblock->acpi_device->handle,
 619                                 "_WED", &input, out);
 620         }
 621
 622         return AE_NOT_FOUND;
 623 }
 624 EXPORT_SYMBOL_GPL(wmi_get_event_data);
 625
 626 /**
 627  * wmi_has_guid - Check if a GUID is available
 628  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 629  *
 630  * Check if a given GUID is defined by _WDG
 631  */
 632 bool wmi_has_guid(const char *guid_string)
 633 {
 634         return find_guid(guid_string, NULL);
 635 }
 636 EXPORT_SYMBOL_GPL(wmi_has_guid);
 637
 638 static struct wmi_block *dev_to_wblock(struct device *dev)
 639 {
 640         return container_of(dev, struct wmi_block, dev.dev);
 641 }
 642
 643 static struct wmi_device *dev_to_wdev(struct device *dev)
 644 {
 645         return container_of(dev, struct wmi_device, dev);
 646 }
 647
 648 /*
 649  * sysfs interface
 650  */
 651 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 652                              char *buf)
 653 {
 654         struct wmi_block *wblock = dev_to_wblock(dev);
 655
 656         return sprintf(buf, "wmi:%pUL\n", wblock->gblock.guid);
 657 }
 658 static DEVICE_ATTR_RO(modalias);
 659
 660 static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
 661                          char *buf)
 662 {
 663         struct wmi_block *wblock = dev_to_wblock(dev);
 664
 665         return sprintf(buf, "%pUL\n", wblock->gblock.guid);
 666 }
 667 static DEVICE_ATTR_RO(guid);
 668
 669 static ssize_t instance_count_show(struct device *dev,
 670                                    struct device_attribute *attr, char *buf)
 671 {
 672         struct wmi_block *wblock = dev_to_wblock(dev);
 673
 674         return sprintf(buf, "%d\n", (int)wblock->gblock.instance_count);
 675 }
 676 static DEVICE_ATTR_RO(instance_count);
 677
 678 static ssize_t expensive_show(struct device *dev,
 679                               struct device_attribute *attr, char *buf)
 680 {
 681         struct wmi_block *wblock = dev_to_wblock(dev);
 682
 683         return sprintf(buf, "%d\n",
 684                        (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
 685 }
 686 static DEVICE_ATTR_RO(expensive);
 687
 688 static struct attribute *wmi_attrs[] = {
 689         &dev_attr_modalias.attr,
 690         &dev_attr_guid.attr,
 691         &dev_attr_instance_count.attr,
 692         &dev_attr_expensive.attr,
 693         NULL,
 694 };
 695 ATTRIBUTE_GROUPS(wmi);
 696
 697 static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
 698                               char *buf)
 699 {
 700         struct wmi_block *wblock = dev_to_wblock(dev);
 701
 702         return sprintf(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
 703 }
 704 static DEVICE_ATTR_RO(notify_id);
 705
 706 static struct attribute *wmi_event_attrs[] = {
 707         &dev_attr_notify_id.attr,
 708         NULL,
 709 };
 710 ATTRIBUTE_GROUPS(wmi_event);
 711
 712 static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
 713                               char *buf)
 714 {
 715         struct wmi_block *wblock = dev_to_wblock(dev);
 716
 717         return sprintf(buf, "%c%c\n", wblock->gblock.object_id[0],
 718                        wblock->gblock.object_id[1]);
 719 }
 720 static DEVICE_ATTR_RO(object_id);
 721
 722 static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
 723                             char *buf)
 724 {
 725         struct wmi_device *wdev = dev_to_wdev(dev);
 726
 727         return sprintf(buf, "%d\n", (int)wdev->setable);
 728 }
 729 static DEVICE_ATTR_RO(setable);
 730
 731 static struct attribute *wmi_data_attrs[] = {
 732         &dev_attr_object_id.attr,
 733         &dev_attr_setable.attr,
 734         NULL,
 735 };
 736 ATTRIBUTE_GROUPS(wmi_data);
 737
 738 static struct attribute *wmi_method_attrs[] = {
 739         &dev_attr_object_id.attr,
 740         NULL,
 741 };
 742 ATTRIBUTE_GROUPS(wmi_method);
 743
 744 static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 745 {
 746         struct wmi_block *wblock = dev_to_wblock(dev);
 747
 748         if (add_uevent_var(env, "MODALIAS=wmi:%pUL", wblock->gblock.guid))
 749                 return -ENOMEM;
 750
 751         if (add_uevent_var(env, "WMI_GUID=%pUL", wblock->gblock.guid))
 752                 return -ENOMEM;
 753
 754         return 0;
 755 }
 756
 757 static void wmi_dev_release(struct device *dev)
 758 {
 759         struct wmi_block *wblock = dev_to_wblock(dev);
 760
 761         kfree(wblock);
 762 }
 763
 764 static int wmi_dev_match(struct device *dev, struct device_driver *driver)
 765 {
 766         struct wmi_driver *wmi_driver =
 767                 container_of(driver, struct wmi_driver, driver);
 768         struct wmi_block *wblock = dev_to_wblock(dev);
 769         const struct wmi_device_id *id = wmi_driver->id_table;
 770
 771         if (id == NULL)
 772                 return 0;
 773
 774         while (*id->guid_string) {
 775                 uuid_le driver_guid;
 776
 777                 if (WARN_ON(uuid_le_to_bin(id->guid_string, &driver_guid)))
 778                         continue;
 779                 if (!memcmp(&driver_guid, wblock->gblock.guid, 16))
 780                         return 1;
 781
 782                 id++;
 783         }
 784
 785         return 0;
 786 }
 787 static int wmi_char_open(struct inode *inode, struct file *filp)
 788 {
 789         const char *driver_name = filp->f_path.dentry->d_iname;
 790         struct wmi_block *wblock = NULL;
 791         struct wmi_block *next = NULL;
 792
 793         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
 794                 if (!wblock->dev.dev.driver)
 795                         continue;
 796                 if (strcmp(driver_name, wblock->dev.dev.driver->name) == 0) {
 797                         filp->private_data = wblock;
 798                         break;
 799                 }
 800         }
 801
 802         if (!filp->private_data)
 803                 return -ENODEV;
 804
 805         return nonseekable_open(inode, filp);
 806 }
 807
 808 static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
 809         size_t length, loff_t *offset)
 810 {
 811         struct wmi_block *wblock = filp->private_data;
 812
 813         return simple_read_from_buffer(buffer, length, offset,
 814                                        &wblock->req_buf_size,
 815                                        sizeof(wblock->req_buf_size));
 816 }
 817
 818 static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 819 {
 820         struct wmi_ioctl_buffer __user *input =
 821                 (struct wmi_ioctl_buffer __user *) arg;
 822         struct wmi_block *wblock = filp->private_data;
 823         struct wmi_ioctl_buffer *buf = NULL;
 824         struct wmi_driver *wdriver = NULL;
 825         int ret;
 826
 827         if (_IOC_TYPE(cmd) != WMI_IOC)
 828                 return -ENOTTY;
 829
 830         /* make sure we're not calling a higher instance than exists*/
 831         if (_IOC_NR(cmd) >= wblock->gblock.instance_count)
 832                 return -EINVAL;
 833
 834         mutex_lock(&wblock->char_mutex);
 835         buf = wblock->handler_data;
 836         if (get_user(buf->length, &input->length)) {
 837                 dev_dbg(&wblock->dev.dev, "Read length from user failed\n");
 838                 ret = -EFAULT;
 839                 goto out_ioctl;
 840         }
 841         /* if it's too small, abort */
 842         if (buf->length < wblock->req_buf_size) {
 843                 dev_err(&wblock->dev.dev,
 844                         "Buffer %lld too small, need at least %lld\n",
 845                         buf->length, wblock->req_buf_size);
 846                 ret = -EINVAL;
 847                 goto out_ioctl;
 848         }
 849         /* if it's too big, warn, driver will only use what is needed */
 850         if (buf->length > wblock->req_buf_size)
 851                 dev_warn(&wblock->dev.dev,
 852                         "Buffer %lld is bigger than required %lld\n",
 853                         buf->length, wblock->req_buf_size);
 854
 855         /* copy the structure from userspace */
 856         if (copy_from_user(buf, input, wblock->req_buf_size)) {
 857                 dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n",
 858                         wblock->req_buf_size);
 859                 ret = -EFAULT;
 860                 goto out_ioctl;
 861         }
 862
 863         /* let the driver do any filtering and do the call */
 864         wdriver = container_of(wblock->dev.dev.driver,
 865                                struct wmi_driver, driver);
 866         if (!try_module_get(wdriver->driver.owner)) {
 867                 ret = -EBUSY;
 868                 goto out_ioctl;
 869         }
 870         ret = wdriver->filter_callback(&wblock->dev, cmd, buf);
 871         module_put(wdriver->driver.owner);
 872         if (ret)
 873                 goto out_ioctl;
 874
 875         /* return the result (only up to our internal buffer size) */
 876         if (copy_to_user(input, buf, wblock->req_buf_size)) {
 877                 dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n",
 878                         wblock->req_buf_size);
 879                 ret = -EFAULT;
 880         }
 881
 882 out_ioctl:
 883         mutex_unlock(&wblock->char_mutex);
 884         return ret;
 885 }
 886
 887 static const struct file_operations wmi_fops = {
 888         .owner          = THIS_MODULE,
 889         .read           = wmi_char_read,
 890         .open           = wmi_char_open,
 891         .unlocked_ioctl = wmi_ioctl,
 892         .compat_ioctl   = wmi_ioctl,
 893 };
 894
 895 static int wmi_dev_probe(struct device *dev)
 896 {
 897         struct wmi_block *wblock = dev_to_wblock(dev);
 898         struct wmi_driver *wdriver =
 899                 container_of(dev->driver, struct wmi_driver, driver);
 900         int ret = 0;
 901         char *buf;
 902
 903         if (ACPI_FAILURE(wmi_method_enable(wblock, 1)))
 904                 dev_warn(dev, "failed to enable device -- probing anyway\n");
 905
 906         if (wdriver->probe) {
 907                 ret = wdriver->probe(dev_to_wdev(dev));
 908                 if (ret != 0)
 909                         goto probe_failure;
 910         }
 911
 912         /* driver wants a character device made */
 913         if (wdriver->filter_callback) {
 914                 /* check that required buffer size declared by driver or MOF */
 915                 if (!wblock->req_buf_size) {
 916                         dev_err(&wblock->dev.dev,
 917                                 "Required buffer size not set\n");
 918                         ret = -EINVAL;
 919                         goto probe_failure;
 920                 }
 921
 922                 wblock->handler_data = kmalloc(wblock->req_buf_size,
 923                                                GFP_KERNEL);
 924                 if (!wblock->handler_data) {
 925                         ret = -ENOMEM;
 926                         goto probe_failure;
 927                 }
 928
 929                 buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name);
 930                 if (!buf) {
 931                         ret = -ENOMEM;
 932                         goto probe_string_failure;
 933                 }
 934                 wblock->char_dev.minor = MISC_DYNAMIC_MINOR;
 935                 wblock->char_dev.name = buf;
 936                 wblock->char_dev.fops = &wmi_fops;
 937                 wblock->char_dev.mode = 0444;
 938                 ret = misc_register(&wblock->char_dev);
 939                 if (ret) {
 940                         dev_warn(dev, "failed to register char dev: %d\n", ret);
 941                         ret = -ENOMEM;
 942                         goto probe_misc_failure;
 943                 }
 944         }
 945
 946         return 0;
 947
 948 probe_misc_failure:
 949         kfree(buf);
 950 probe_string_failure:
 951         kfree(wblock->handler_data);
 952 probe_failure:
 953         if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
 954                 dev_warn(dev, "failed to disable device\n");
 955         return ret;
 956 }
 957
 958 static int wmi_dev_remove(struct device *dev)
 959 {
 960         struct wmi_block *wblock = dev_to_wblock(dev);
 961         struct wmi_driver *wdriver =
 962                 container_of(dev->driver, struct wmi_driver, driver);
 963         int ret = 0;
 964
 965         if (wdriver->filter_callback) {
 966                 misc_deregister(&wblock->char_dev);
 967                 kfree(wblock->char_dev.name);
 968                 kfree(wblock->handler_data);
 969         }
 970
 971         if (wdriver->remove)
 972                 ret = wdriver->remove(dev_to_wdev(dev));
 973
 974         if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
 975                 dev_warn(dev, "failed to disable device\n");
 976
 977         return ret;
 978 }
 979
 980 static struct class wmi_bus_class = {
 981         .name = "wmi_bus",
 982 };
 983
 984 static struct bus_type wmi_bus_type = {
 985         .name = "wmi",
 986         .dev_groups = wmi_groups,
 987         .match = wmi_dev_match,
 988         .uevent = wmi_dev_uevent,
 989         .probe = wmi_dev_probe,
 990         .remove = wmi_dev_remove,
 991 };
 992
 993 static const struct device_type wmi_type_event = {
 994         .name = "event",
 995         .groups = wmi_event_groups,
 996         .release = wmi_dev_release,
 997 };
 998
 999 static const struct device_type wmi_type_method = {
1000         .name = "method",
1001         .groups = wmi_method_groups,
1002         .release = wmi_dev_release,
1003 };
1004
1005 static const struct device_type wmi_type_data = {
1006         .name = "data",
1007         .groups = wmi_data_groups,
1008         .release = wmi_dev_release,
1009 };
1010
1011 static int wmi_create_device(struct device *wmi_bus_dev,
1012                              const struct guid_block *gblock,
1013                              struct wmi_block *wblock,
1014                              struct acpi_device *device)
1015 {
1016         struct acpi_device_info *info;
1017         char method[5];
1018         int result;
1019
1020         if (gblock->flags & ACPI_WMI_EVENT) {
1021                 wblock->dev.dev.type = &wmi_type_event;
1022                 goto out_init;
1023         }
1024
1025         if (gblock->flags & ACPI_WMI_METHOD) {
1026                 wblock->dev.dev.type = &wmi_type_method;
1027                 mutex_init(&wblock->char_mutex);
1028                 goto out_init;
1029         }
1030
1031         /*
1032          * Data Block Query Control Method (WQxx by convention) is
1033          * required per the WMI documentation. If it is not present,
1034          * we ignore this data block.
1035          */
1036         strcpy(method, "WQ");
1037         strncat(method, wblock->gblock.object_id, 2);
1038         result = get_subobj_info(device->handle, method, &info);
1039
1040         if (result) {
1041                 dev_warn(wmi_bus_dev,
1042                          "%s data block query control method not found\n",
1043                          method);
1044                 return result;
1045         }
1046
1047         wblock->dev.dev.type = &wmi_type_data;
1048
1049         /*
1050          * The Microsoft documentation specifically states:
1051          *
1052          *   Data blocks registered with only a single instance
1053          *   can ignore the parameter.
1054          *
1055          * ACPICA will get mad at us if we call the method with the wrong number
1056          * of arguments, so check what our method expects.  (On some Dell
1057          * laptops, WQxx may not be a method at all.)
1058          */
1059         if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1060                 wblock->read_takes_no_args = true;
1061
1062         kfree(info);
1063
1064         strcpy(method, "WS");
1065         strncat(method, wblock->gblock.object_id, 2);
1066         result = get_subobj_info(device->handle, method, NULL);
1067
1068         if (result == 0)
1069                 wblock->dev.setable = true;
1070
1071  out_init:
1072         wblock->dev.dev.bus = &wmi_bus_type;
1073         wblock->dev.dev.parent = wmi_bus_dev;
1074
1075         dev_set_name(&wblock->dev.dev, "%pUL", gblock->guid);
1076
1077         device_initialize(&wblock->dev.dev);
1078
1079         return 0;
1080 }
1081
1082 static void wmi_free_devices(struct acpi_device *device)
1083 {
1084         struct wmi_block *wblock, *next;
1085
1086         /* Delete devices for all the GUIDs */
1087         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1088                 if (wblock->acpi_device == device) {
1089                         list_del(&wblock->list);
1090                         device_unregister(&wblock->dev.dev);
1091                 }
1092         }
1093 }
1094
1095 static bool guid_already_parsed(struct acpi_device *device,
1096                                 const u8 *guid)
1097 {
1098         struct wmi_block *wblock;
1099
1100         list_for_each_entry(wblock, &wmi_block_list, list) {
1101                 if (memcmp(wblock->gblock.guid, guid, 16) == 0) {
1102                         /*
1103                          * Because we historically didn't track the relationship
1104                          * between GUIDs and ACPI nodes, we don't know whether
1105                          * we need to suppress GUIDs that are unique on a
1106                          * given node but duplicated across nodes.
1107                          */
1108                         dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
1109                                  guid, dev_name(&wblock->acpi_device->dev));
1110                         return true;
1111                 }
1112         }
1113
1114         return false;
1115 }
1116
1117 /*
1118  * Parse the _WDG method for the GUID data blocks
1119  */
1120 static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
1121 {
1122         struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1123         const struct guid_block *gblock;
1124         struct wmi_block *wblock, *next;
1125         union acpi_object *obj;
1126         acpi_status status;
1127         int retval = 0;
1128         u32 i, total;
1129
1130         status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1131         if (ACPI_FAILURE(status))
1132                 return -ENXIO;
1133
1134         obj = (union acpi_object *) out.pointer;
1135         if (!obj)
1136                 return -ENXIO;
1137
1138         if (obj->type != ACPI_TYPE_BUFFER) {
1139                 retval = -ENXIO;
1140                 goto out_free_pointer;
1141         }
1142
1143         gblock = (const struct guid_block *)obj->buffer.pointer;
1144         total = obj->buffer.length / sizeof(struct guid_block);
1145
1146         for (i = 0; i < total; i++) {
1147                 if (debug_dump_wdg)
1148                         wmi_dump_wdg(&gblock[i]);
1149
1150                 /*
1151                  * Some WMI devices, like those for nVidia hooks, have a
1152                  * duplicate GUID. It's not clear what we should do in this
1153                  * case yet, so for now, we'll just ignore the duplicate
1154                  * for device creation.
1155                  */
1156                 if (guid_already_parsed(device, gblock[i].guid))
1157                         continue;
1158
1159                 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
1160                 if (!wblock) {
1161                         retval = -ENOMEM;
1162                         break;
1163                 }
1164
1165                 wblock->acpi_device = device;
1166                 wblock->gblock = gblock[i];
1167
1168                 retval = wmi_create_device(wmi_bus_dev, &gblock[i], wblock, device);
1169                 if (retval) {
1170                         kfree(wblock);
1171                         continue;
1172                 }
1173
1174                 list_add_tail(&wblock->list, &wmi_block_list);
1175
1176                 if (debug_event) {
1177                         wblock->handler = wmi_notify_debug;
1178                         wmi_method_enable(wblock, 1);
1179                 }
1180         }
1181
1182         /*
1183          * Now that all of the devices are created, add them to the
1184          * device tree and probe subdrivers.
1185          */
1186         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1187                 if (wblock->acpi_device != device)
1188                         continue;
1189
1190                 retval = device_add(&wblock->dev.dev);
1191                 if (retval) {
1192                         dev_err(wmi_bus_dev, "failed to register %pUL\n",
1193                                 wblock->gblock.guid);
1194                         if (debug_event)
1195                                 wmi_method_enable(wblock, 0);
1196                         list_del(&wblock->list);
1197                         put_device(&wblock->dev.dev);
1198                 }
1199         }
1200
1201 out_free_pointer:
1202         kfree(out.pointer);
1203         return retval;
1204 }
1205
1206 /*
1207  * WMI can have EmbeddedControl access regions. In which case, we just want to
1208  * hand these off to the EC driver.
1209  */
1210 static acpi_status
1211 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1212                       u32 bits, u64 *value,
1213                       void *handler_context, void *region_context)
1214 {
1215         int result = 0, i = 0;
1216         u8 temp = 0;
1217
1218         if ((address > 0xFF) || !value)
1219                 return AE_BAD_PARAMETER;
1220
1221         if (function != ACPI_READ && function != ACPI_WRITE)
1222                 return AE_BAD_PARAMETER;
1223
1224         if (bits != 8)
1225                 return AE_BAD_PARAMETER;
1226
1227         if (function == ACPI_READ) {
1228                 result = ec_read(address, &temp);
1229                 (*value) |= ((u64)temp) << i;
1230         } else {
1231                 temp = 0xff & ((*value) >> i);
1232                 result = ec_write(address, temp);
1233         }
1234
1235         switch (result) {
1236         case -EINVAL:
1237                 return AE_BAD_PARAMETER;
1238                 break;
1239         case -ENODEV:
1240                 return AE_NOT_FOUND;
1241                 break;
1242         case -ETIME:
1243                 return AE_TIME;
1244                 break;
1245         default:
1246                 return AE_OK;
1247         }
1248 }
1249
1250 static void acpi_wmi_notify_handler(acpi_handle handle, u32 event,
1251                                     void *context)
1252 {
1253         struct guid_block *block;
1254         struct wmi_block *wblock;
1255         bool found_it = false;
1256
1257         list_for_each_entry(wblock, &wmi_block_list, list) {
1258                 block = &wblock->gblock;
1259
1260                 if (wblock->acpi_device->handle == handle &&
1261                     (block->flags & ACPI_WMI_EVENT) &&
1262                     (block->notify_id == event))
1263                 {
1264                         found_it = true;
1265                         break;
1266                 }
1267         }
1268
1269         if (!found_it)
1270                 return;
1271
1272         /* If a driver is bound, then notify the driver. */
1273         if (wblock->dev.dev.driver) {
1274                 struct wmi_driver *driver;
1275                 struct acpi_object_list input;
1276                 union acpi_object params[1];
1277                 struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL };
1278                 acpi_status status;
1279
1280                 driver = container_of(wblock->dev.dev.driver,
1281                                       struct wmi_driver, driver);
1282
1283                 input.count = 1;
1284                 input.pointer = params;
1285                 params[0].type = ACPI_TYPE_INTEGER;
1286                 params[0].integer.value = event;
1287
1288                 status = acpi_evaluate_object(wblock->acpi_device->handle,
1289                                               "_WED", &input, &evdata);
1290                 if (ACPI_FAILURE(status)) {
1291                         dev_warn(&wblock->dev.dev,
1292                                  "failed to get event data\n");
1293                         return;
1294                 }
1295
1296                 if (driver->notify)
1297                         driver->notify(&wblock->dev,
1298                                        (union acpi_object *)evdata.pointer);
1299
1300                 kfree(evdata.pointer);
1301         } else if (wblock->handler) {
1302                 /* Legacy handler */
1303                 wblock->handler(event, wblock->handler_data);
1304         }
1305
1306         if (debug_event) {
1307                 pr_info("DEBUG Event GUID: %pUL\n",
1308                         wblock->gblock.guid);
1309         }
1310
1311         acpi_bus_generate_netlink_event(
1312                 wblock->acpi_device->pnp.device_class,
1313                 dev_name(&wblock->dev.dev),
1314                 event, 0);
1315
1316 }
1317
1318 static int acpi_wmi_remove(struct platform_device *device)
1319 {
1320         struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev);
1321
1322         acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1323                                    acpi_wmi_notify_handler);
1324         acpi_remove_address_space_handler(acpi_device->handle,
1325                                 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
1326         wmi_free_devices(acpi_device);
1327         device_destroy(&wmi_bus_class, MKDEV(0, 0));
1328
1329         return 0;
1330 }
1331
1332 static int acpi_wmi_probe(struct platform_device *device)
1333 {
1334         struct acpi_device *acpi_device;
1335         struct device *wmi_bus_dev;
1336         acpi_status status;
1337         int error;
1338
1339         acpi_device = ACPI_COMPANION(&device->dev);
1340         if (!acpi_device) {
1341                 dev_err(&device->dev, "ACPI companion is missing\n");
1342                 return -ENODEV;
1343         }
1344
1345         status = acpi_install_address_space_handler(acpi_device->handle,
1346                                                     ACPI_ADR_SPACE_EC,
1347                                                     &acpi_wmi_ec_space_handler,
1348                                                     NULL, NULL);
1349         if (ACPI_FAILURE(status)) {
1350                 dev_err(&device->dev, "Error installing EC region handler\n");
1351                 return -ENODEV;
1352         }
1353
1354         status = acpi_install_notify_handler(acpi_device->handle,
1355                                              ACPI_DEVICE_NOTIFY,
1356                                              acpi_wmi_notify_handler,
1357                                              NULL);
1358         if (ACPI_FAILURE(status)) {
1359                 dev_err(&device->dev, "Error installing notify handler\n");
1360                 error = -ENODEV;
1361                 goto err_remove_ec_handler;
1362         }
1363
1364         wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0),
1365                                     NULL, "wmi_bus-%s", dev_name(&device->dev));
1366         if (IS_ERR(wmi_bus_dev)) {
1367                 error = PTR_ERR(wmi_bus_dev);
1368                 goto err_remove_notify_handler;
1369         }
1370         dev_set_drvdata(&device->dev, wmi_bus_dev);
1371
1372         error = parse_wdg(wmi_bus_dev, acpi_device);
1373         if (error) {
1374                 pr_err("Failed to parse WDG method\n");
1375                 goto err_remove_busdev;
1376         }
1377
1378         return 0;
1379
1380 err_remove_busdev:
1381         device_destroy(&wmi_bus_class, MKDEV(0, 0));
1382
1383 err_remove_notify_handler:
1384         acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1385                                    acpi_wmi_notify_handler);
1386
1387 err_remove_ec_handler:
1388         acpi_remove_address_space_handler(acpi_device->handle,
1389                                           ACPI_ADR_SPACE_EC,
1390                                           &acpi_wmi_ec_space_handler);
1391
1392         return error;
1393 }
1394
1395 int __must_check __wmi_driver_register(struct wmi_driver *driver,
1396                                        struct module *owner)
1397 {
1398         driver->driver.owner = owner;
1399         driver->driver.bus = &wmi_bus_type;
1400
1401         return driver_register(&driver->driver);
1402 }
1403 EXPORT_SYMBOL(__wmi_driver_register);
1404
1405 void wmi_driver_unregister(struct wmi_driver *driver)
1406 {
1407         driver_unregister(&driver->driver);
1408 }
1409 EXPORT_SYMBOL(wmi_driver_unregister);
1410
1411 static int __init acpi_wmi_init(void)
1412 {
1413         int error;
1414
1415         if (acpi_disabled)
1416                 return -ENODEV;
1417
1418         error = class_register(&wmi_bus_class);
1419         if (error)
1420                 return error;
1421
1422         error = bus_register(&wmi_bus_type);
1423         if (error)
1424                 goto err_unreg_class;
1425
1426         error = platform_driver_register(&acpi_wmi_driver);
1427         if (error) {
1428                 pr_err("Error loading mapper\n");
1429                 goto err_unreg_bus;
1430         }
1431
1432         return 0;
1433
1434 err_unreg_bus:
1435         bus_unregister(&wmi_bus_type);
1436
1437 err_unreg_class:
1438         class_unregister(&wmi_bus_class);
1439
1440         return error;
1441 }
1442
1443 static void __exit acpi_wmi_exit(void)
1444 {
1445         platform_driver_unregister(&acpi_wmi_driver);
1446         bus_unregister(&wmi_bus_type);
1447         class_unregister(&wmi_bus_class);
1448 }
1449
1450 subsys_initcall_sync(acpi_wmi_init);
1451 module_exit(acpi_wmi_exit);