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         struct list_head *p;
 134
 135         if (uuid_le_to_bin(guid_string, &guid_input))
 136                 return false;
 137
 138         list_for_each(p, &wmi_block_list) {
 139                 wblock = list_entry(p, struct wmi_block, list);
 140                 block = &wblock->gblock;
 141
 142                 if (memcmp(block->guid, &guid_input, 16) == 0) {
 143                         if (out)
 144                                 *out = wblock;
 145                         return true;
 146                 }
 147         }
 148         return false;
 149 }
 150
 151 static int get_subobj_info(acpi_handle handle, const char *pathname,
 152                            struct acpi_device_info **info)
 153 {
 154         struct acpi_device_info *dummy_info, **info_ptr;
 155         acpi_handle subobj_handle;
 156         acpi_status status;
 157
 158         status = acpi_get_handle(handle, (char *)pathname, &subobj_handle);
 159         if (status == AE_NOT_FOUND)
 160                 return -ENOENT;
 161         else if (ACPI_FAILURE(status))
 162                 return -EIO;
 163
 164         info_ptr = info ? info : &dummy_info;
 165         status = acpi_get_object_info(subobj_handle, info_ptr);
 166         if (ACPI_FAILURE(status))
 167                 return -EIO;
 168
 169         if (!info)
 170                 kfree(dummy_info);
 171
 172         return 0;
 173 }
 174
 175 static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable)
 176 {
 177         struct guid_block *block = NULL;
 178         char method[5];
 179         acpi_status status;
 180         acpi_handle handle;
 181
 182         block = &wblock->gblock;
 183         handle = wblock->acpi_device->handle;
 184
 185         snprintf(method, 5, "WE%02X", block->notify_id);
 186         status = acpi_execute_simple_method(handle, method, enable);
 187
 188         if (status != AE_OK && status != AE_NOT_FOUND)
 189                 return status;
 190         else
 191                 return AE_OK;
 192 }
 193
 194 /*
 195  * Exported WMI functions
 196  */
 197
 198 /**
 199  * set_required_buffer_size - Sets the buffer size needed for performing IOCTL
 200  * @wdev: A wmi bus device from a driver
 201  * @instance: Instance index
 202  *
 203  * Allocates memory needed for buffer, stores the buffer size in that memory
 204  */
 205 int set_required_buffer_size(struct wmi_device *wdev, u64 length)
 206 {
 207         struct wmi_block *wblock;
 208
 209         wblock = container_of(wdev, struct wmi_block, dev);
 210         wblock->req_buf_size = length;
 211
 212         return 0;
 213 }
 214 EXPORT_SYMBOL_GPL(set_required_buffer_size);
 215
 216 /**
 217  * wmi_evaluate_method - Evaluate a WMI method
 218  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 219  * @instance: Instance index
 220  * @method_id: Method ID to call
 221  * &in: Buffer containing input for the method call
 222  * &out: Empty buffer to return the method results
 223  *
 224  * Call an ACPI-WMI method
 225  */
 226 acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
 227 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
 228 {
 229         struct wmi_block *wblock = NULL;
 230
 231         if (!find_guid(guid_string, &wblock))
 232                 return AE_ERROR;
 233         return wmidev_evaluate_method(&wblock->dev, instance, method_id,
 234                                       in, out);
 235 }
 236 EXPORT_SYMBOL_GPL(wmi_evaluate_method);
 237
 238 /**
 239  * wmidev_evaluate_method - Evaluate a WMI method
 240  * @wdev: A wmi bus device from a driver
 241  * @instance: Instance index
 242  * @method_id: Method ID to call
 243  * &in: Buffer containing input for the method call
 244  * &out: Empty buffer to return the method results
 245  *
 246  * Call an ACPI-WMI method
 247  */
 248 acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance,
 249         u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
 250 {
 251         struct guid_block *block = NULL;
 252         struct wmi_block *wblock = NULL;
 253         acpi_handle handle;
 254         acpi_status status;
 255         struct acpi_object_list input;
 256         union acpi_object params[3];
 257         char method[5] = "WM";
 258
 259         wblock = container_of(wdev, struct wmi_block, dev);
 260         block = &wblock->gblock;
 261         handle = wblock->acpi_device->handle;
 262
 263         if (!(block->flags & ACPI_WMI_METHOD))
 264                 return AE_BAD_DATA;
 265
 266         if (block->instance_count <= instance)
 267                 return AE_BAD_PARAMETER;
 268
 269         input.count = 2;
 270         input.pointer = params;
 271         params[0].type = ACPI_TYPE_INTEGER;
 272         params[0].integer.value = instance;
 273         params[1].type = ACPI_TYPE_INTEGER;
 274         params[1].integer.value = method_id;
 275
 276         if (in) {
 277                 input.count = 3;
 278
 279                 if (block->flags & ACPI_WMI_STRING) {
 280                         params[2].type = ACPI_TYPE_STRING;
 281                 } else {
 282                         params[2].type = ACPI_TYPE_BUFFER;
 283                 }
 284                 params[2].buffer.length = in->length;
 285                 params[2].buffer.pointer = in->pointer;
 286         }
 287
 288         strncat(method, block->object_id, 2);
 289
 290         status = acpi_evaluate_object(handle, method, &input, out);
 291
 292         return status;
 293 }
 294 EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
 295
 296 static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
 297                                  struct acpi_buffer *out)
 298 {
 299         struct guid_block *block = NULL;
 300         acpi_handle handle;
 301         acpi_status status, wc_status = AE_ERROR;
 302         struct acpi_object_list input;
 303         union acpi_object wq_params[1];
 304         char method[5];
 305         char wc_method[5] = "WC";
 306
 307         if (!out)
 308                 return AE_BAD_PARAMETER;
 309
 310         block = &wblock->gblock;
 311         handle = wblock->acpi_device->handle;
 312
 313         if (block->instance_count <= instance)
 314                 return AE_BAD_PARAMETER;
 315
 316         /* Check GUID is a data block */
 317         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 318                 return AE_ERROR;
 319
 320         input.count = 1;
 321         input.pointer = wq_params;
 322         wq_params[0].type = ACPI_TYPE_INTEGER;
 323         wq_params[0].integer.value = instance;
 324
 325         if (instance == 0 && wblock->read_takes_no_args)
 326                 input.count = 0;
 327
 328         /*
 329          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
 330          * enable collection.
 331          */
 332         if (block->flags & ACPI_WMI_EXPENSIVE) {
 333                 strncat(wc_method, block->object_id, 2);
 334
 335                 /*
 336                  * Some GUIDs break the specification by declaring themselves
 337                  * expensive, but have no corresponding WCxx method. So we
 338                  * should not fail if this happens.
 339                  */
 340                 if (acpi_has_method(handle, wc_method))
 341                         wc_status = acpi_execute_simple_method(handle,
 342                                                                 wc_method, 1);
 343         }
 344
 345         strcpy(method, "WQ");
 346         strncat(method, block->object_id, 2);
 347
 348         status = acpi_evaluate_object(handle, method, &input, out);
 349
 350         /*
 351          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
 352          * the WQxx method failed - we should disable collection anyway.
 353          */
 354         if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
 355                 status = acpi_execute_simple_method(handle, wc_method, 0);
 356         }
 357
 358         return status;
 359 }
 360
 361 /**
 362  * wmi_query_block - Return contents of a WMI block (deprecated)
 363  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 364  * @instance: Instance index
 365  * &out: Empty buffer to return the contents of the data block to
 366  *
 367  * Return the contents of an ACPI-WMI data block to a buffer
 368  */
 369 acpi_status wmi_query_block(const char *guid_string, u8 instance,
 370                             struct acpi_buffer *out)
 371 {
 372         struct wmi_block *wblock;
 373
 374         if (!guid_string)
 375                 return AE_BAD_PARAMETER;
 376
 377         if (!find_guid(guid_string, &wblock))
 378                 return AE_ERROR;
 379
 380         return __query_block(wblock, instance, out);
 381 }
 382 EXPORT_SYMBOL_GPL(wmi_query_block);
 383
 384 union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
 385 {
 386         struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
 387         struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
 388
 389         if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
 390                 return NULL;
 391
 392         return (union acpi_object *)out.pointer;
 393 }
 394 EXPORT_SYMBOL_GPL(wmidev_block_query);
 395
 396 /**
 397  * wmi_set_block - Write to a WMI block
 398  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 399  * @instance: Instance index
 400  * &in: Buffer containing new values for the data block
 401  *
 402  * Write the contents of the input buffer to an ACPI-WMI data block
 403  */
 404 acpi_status wmi_set_block(const char *guid_string, u8 instance,
 405                           const struct acpi_buffer *in)
 406 {
 407         struct guid_block *block = NULL;
 408         struct wmi_block *wblock = NULL;
 409         acpi_handle handle;
 410         struct acpi_object_list input;
 411         union acpi_object params[2];
 412         char method[5] = "WS";
 413
 414         if (!guid_string || !in)
 415                 return AE_BAD_DATA;
 416
 417         if (!find_guid(guid_string, &wblock))
 418                 return AE_ERROR;
 419
 420         block = &wblock->gblock;
 421         handle = wblock->acpi_device->handle;
 422
 423         if (block->instance_count <= instance)
 424                 return AE_BAD_PARAMETER;
 425
 426         /* Check GUID is a data block */
 427         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 428                 return AE_ERROR;
 429
 430         input.count = 2;
 431         input.pointer = params;
 432         params[0].type = ACPI_TYPE_INTEGER;
 433         params[0].integer.value = instance;
 434
 435         if (block->flags & ACPI_WMI_STRING) {
 436                 params[1].type = ACPI_TYPE_STRING;
 437         } else {
 438                 params[1].type = ACPI_TYPE_BUFFER;
 439         }
 440         params[1].buffer.length = in->length;
 441         params[1].buffer.pointer = in->pointer;
 442
 443         strncat(method, block->object_id, 2);
 444
 445         return acpi_evaluate_object(handle, method, &input, NULL);
 446 }
 447 EXPORT_SYMBOL_GPL(wmi_set_block);
 448
 449 static void wmi_dump_wdg(const struct guid_block *g)
 450 {
 451         pr_info("%pUL:\n", g->guid);
 452         if (g->flags & ACPI_WMI_EVENT)
 453                 pr_info("\tnotify_id: 0x%02X\n", g->notify_id);
 454         else
 455                 pr_info("\tobject_id: %2pE\n", g->object_id);
 456         pr_info("\tinstance_count: %d\n", g->instance_count);
 457         pr_info("\tflags: %#x", g->flags);
 458         if (g->flags) {
 459                 if (g->flags & ACPI_WMI_EXPENSIVE)
 460                         pr_cont(" ACPI_WMI_EXPENSIVE");
 461                 if (g->flags & ACPI_WMI_METHOD)
 462                         pr_cont(" ACPI_WMI_METHOD");
 463                 if (g->flags & ACPI_WMI_STRING)
 464                         pr_cont(" ACPI_WMI_STRING");
 465                 if (g->flags & ACPI_WMI_EVENT)
 466                         pr_cont(" ACPI_WMI_EVENT");
 467         }
 468         pr_cont("\n");
 469
 470 }
 471
 472 static void wmi_notify_debug(u32 value, void *context)
 473 {
 474         struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
 475         union acpi_object *obj;
 476         acpi_status status;
 477
 478         status = wmi_get_event_data(value, &response);
 479         if (status != AE_OK) {
 480                 pr_info("bad event status 0x%x\n", status);
 481                 return;
 482         }
 483
 484         obj = (union acpi_object *)response.pointer;
 485
 486         if (!obj)
 487                 return;
 488
 489         pr_info("DEBUG Event ");
 490         switch(obj->type) {
 491         case ACPI_TYPE_BUFFER:
 492                 pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
 493                 break;
 494         case ACPI_TYPE_STRING:
 495                 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
 496                 break;
 497         case ACPI_TYPE_INTEGER:
 498                 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
 499                 break;
 500         case ACPI_TYPE_PACKAGE:
 501                 pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
 502                 break;
 503         default:
 504                 pr_cont("object type 0x%X\n", obj->type);
 505         }
 506         kfree(obj);
 507 }
 508
 509 /**
 510  * wmi_install_notify_handler - Register handler for WMI events
 511  * @handler: Function to handle notifications
 512  * @data: Data to be returned to handler when event is fired
 513  *
 514  * Register a handler for events sent to the ACPI-WMI mapper device.
 515  */
 516 acpi_status wmi_install_notify_handler(const char *guid,
 517 wmi_notify_handler handler, void *data)
 518 {
 519         struct wmi_block *block;
 520         acpi_status status = AE_NOT_EXIST;
 521         uuid_le guid_input;
 522         struct list_head *p;
 523
 524         if (!guid || !handler)
 525                 return AE_BAD_PARAMETER;
 526
 527         if (uuid_le_to_bin(guid, &guid_input))
 528                 return AE_BAD_PARAMETER;
 529
 530         list_for_each(p, &wmi_block_list) {
 531                 acpi_status wmi_status;
 532                 block = list_entry(p, struct wmi_block, list);
 533
 534                 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
 535                         if (block->handler &&
 536                             block->handler != wmi_notify_debug)
 537                                 return AE_ALREADY_ACQUIRED;
 538
 539                         block->handler = handler;
 540                         block->handler_data = data;
 541
 542                         wmi_status = wmi_method_enable(block, 1);
 543                         if ((wmi_status != AE_OK) ||
 544                             ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
 545                                 status = wmi_status;
 546                 }
 547         }
 548
 549         return status;
 550 }
 551 EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
 552
 553 /**
 554  * wmi_uninstall_notify_handler - Unregister handler for WMI events
 555  *
 556  * Unregister handler for events sent to the ACPI-WMI mapper device.
 557  */
 558 acpi_status wmi_remove_notify_handler(const char *guid)
 559 {
 560         struct wmi_block *block;
 561         acpi_status status = AE_NOT_EXIST;
 562         uuid_le guid_input;
 563         struct list_head *p;
 564
 565         if (!guid)
 566                 return AE_BAD_PARAMETER;
 567
 568         if (uuid_le_to_bin(guid, &guid_input))
 569                 return AE_BAD_PARAMETER;
 570
 571         list_for_each(p, &wmi_block_list) {
 572                 acpi_status wmi_status;
 573                 block = list_entry(p, struct wmi_block, list);
 574
 575                 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
 576                         if (!block->handler ||
 577                             block->handler == wmi_notify_debug)
 578                                 return AE_NULL_ENTRY;
 579
 580                         if (debug_event) {
 581                                 block->handler = wmi_notify_debug;
 582                                 status = AE_OK;
 583                         } else {
 584                                 wmi_status = wmi_method_enable(block, 0);
 585                                 block->handler = NULL;
 586                                 block->handler_data = NULL;
 587                                 if ((wmi_status != AE_OK) ||
 588                                     ((wmi_status == AE_OK) &&
 589                                      (status == AE_NOT_EXIST)))
 590                                         status = wmi_status;
 591                         }
 592                 }
 593         }
 594
 595         return status;
 596 }
 597 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
 598
 599 /**
 600  * wmi_get_event_data - Get WMI data associated with an event
 601  *
 602  * @event: Event to find
 603  * @out: Buffer to hold event data. out->pointer should be freed with kfree()
 604  *
 605  * Returns extra data associated with an event in WMI.
 606  */
 607 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
 608 {
 609         struct acpi_object_list input;
 610         union acpi_object params[1];
 611         struct guid_block *gblock;
 612         struct wmi_block *wblock;
 613         struct list_head *p;
 614
 615         input.count = 1;
 616         input.pointer = params;
 617         params[0].type = ACPI_TYPE_INTEGER;
 618         params[0].integer.value = event;
 619
 620         list_for_each(p, &wmi_block_list) {
 621                 wblock = list_entry(p, struct wmi_block, list);
 622                 gblock = &wblock->gblock;
 623
 624                 if ((gblock->flags & ACPI_WMI_EVENT) &&
 625                         (gblock->notify_id == event))
 626                         return acpi_evaluate_object(wblock->acpi_device->handle,
 627                                 "_WED", &input, out);
 628         }
 629
 630         return AE_NOT_FOUND;
 631 }
 632 EXPORT_SYMBOL_GPL(wmi_get_event_data);
 633
 634 /**
 635  * wmi_has_guid - Check if a GUID is available
 636  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 637  *
 638  * Check if a given GUID is defined by _WDG
 639  */
 640 bool wmi_has_guid(const char *guid_string)
 641 {
 642         return find_guid(guid_string, NULL);
 643 }
 644 EXPORT_SYMBOL_GPL(wmi_has_guid);
 645
 646 static struct wmi_block *dev_to_wblock(struct device *dev)
 647 {
 648         return container_of(dev, struct wmi_block, dev.dev);
 649 }
 650
 651 static struct wmi_device *dev_to_wdev(struct device *dev)
 652 {
 653         return container_of(dev, struct wmi_device, dev);
 654 }
 655
 656 /*
 657  * sysfs interface
 658  */
 659 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 660                              char *buf)
 661 {
 662         struct wmi_block *wblock = dev_to_wblock(dev);
 663
 664         return sprintf(buf, "wmi:%pUL\n", wblock->gblock.guid);
 665 }
 666 static DEVICE_ATTR_RO(modalias);
 667
 668 static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
 669                          char *buf)
 670 {
 671         struct wmi_block *wblock = dev_to_wblock(dev);
 672
 673         return sprintf(buf, "%pUL\n", wblock->gblock.guid);
 674 }
 675 static DEVICE_ATTR_RO(guid);
 676
 677 static ssize_t instance_count_show(struct device *dev,
 678                                    struct device_attribute *attr, char *buf)
 679 {
 680         struct wmi_block *wblock = dev_to_wblock(dev);
 681
 682         return sprintf(buf, "%d\n", (int)wblock->gblock.instance_count);
 683 }
 684 static DEVICE_ATTR_RO(instance_count);
 685
 686 static ssize_t expensive_show(struct device *dev,
 687                               struct device_attribute *attr, char *buf)
 688 {
 689         struct wmi_block *wblock = dev_to_wblock(dev);
 690
 691         return sprintf(buf, "%d\n",
 692                        (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
 693 }
 694 static DEVICE_ATTR_RO(expensive);
 695
 696 static struct attribute *wmi_attrs[] = {
 697         &dev_attr_modalias.attr,
 698         &dev_attr_guid.attr,
 699         &dev_attr_instance_count.attr,
 700         &dev_attr_expensive.attr,
 701         NULL,
 702 };
 703 ATTRIBUTE_GROUPS(wmi);
 704
 705 static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
 706                               char *buf)
 707 {
 708         struct wmi_block *wblock = dev_to_wblock(dev);
 709
 710         return sprintf(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
 711 }
 712 static DEVICE_ATTR_RO(notify_id);
 713
 714 static struct attribute *wmi_event_attrs[] = {
 715         &dev_attr_notify_id.attr,
 716         NULL,
 717 };
 718 ATTRIBUTE_GROUPS(wmi_event);
 719
 720 static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
 721                               char *buf)
 722 {
 723         struct wmi_block *wblock = dev_to_wblock(dev);
 724
 725         return sprintf(buf, "%c%c\n", wblock->gblock.object_id[0],
 726                        wblock->gblock.object_id[1]);
 727 }
 728 static DEVICE_ATTR_RO(object_id);
 729
 730 static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
 731                             char *buf)
 732 {
 733         struct wmi_device *wdev = dev_to_wdev(dev);
 734
 735         return sprintf(buf, "%d\n", (int)wdev->setable);
 736 }
 737 static DEVICE_ATTR_RO(setable);
 738
 739 static struct attribute *wmi_data_attrs[] = {
 740         &dev_attr_object_id.attr,
 741         &dev_attr_setable.attr,
 742         NULL,
 743 };
 744 ATTRIBUTE_GROUPS(wmi_data);
 745
 746 static struct attribute *wmi_method_attrs[] = {
 747         &dev_attr_object_id.attr,
 748         NULL,
 749 };
 750 ATTRIBUTE_GROUPS(wmi_method);
 751
 752 static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 753 {
 754         struct wmi_block *wblock = dev_to_wblock(dev);
 755
 756         if (add_uevent_var(env, "MODALIAS=wmi:%pUL", wblock->gblock.guid))
 757                 return -ENOMEM;
 758
 759         if (add_uevent_var(env, "WMI_GUID=%pUL", wblock->gblock.guid))
 760                 return -ENOMEM;
 761
 762         return 0;
 763 }
 764
 765 static void wmi_dev_release(struct device *dev)
 766 {
 767         struct wmi_block *wblock = dev_to_wblock(dev);
 768
 769         kfree(wblock);
 770 }
 771
 772 static int wmi_dev_match(struct device *dev, struct device_driver *driver)
 773 {
 774         struct wmi_driver *wmi_driver =
 775                 container_of(driver, struct wmi_driver, driver);
 776         struct wmi_block *wblock = dev_to_wblock(dev);
 777         const struct wmi_device_id *id = wmi_driver->id_table;
 778
 779         while (id->guid_string) {
 780                 uuid_le driver_guid;
 781
 782                 if (WARN_ON(uuid_le_to_bin(id->guid_string, &driver_guid)))
 783                         continue;
 784                 if (!memcmp(&driver_guid, wblock->gblock.guid, 16))
 785                         return 1;
 786
 787                 id++;
 788         }
 789
 790         return 0;
 791 }
 792 static int wmi_char_open(struct inode *inode, struct file *filp)
 793 {
 794         const char *driver_name = filp->f_path.dentry->d_iname;
 795         struct wmi_block *wblock = NULL;
 796         struct wmi_block *next = NULL;
 797
 798         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
 799                 if (!wblock->dev.dev.driver)
 800                         continue;
 801                 if (strcmp(driver_name, wblock->dev.dev.driver->name) == 0) {
 802                         filp->private_data = wblock;
 803                         break;
 804                 }
 805         }
 806
 807         if (!filp->private_data)
 808                 return -ENODEV;
 809
 810         return nonseekable_open(inode, filp);
 811 }
 812
 813 static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
 814         size_t length, loff_t *offset)
 815 {
 816         struct wmi_block *wblock = filp->private_data;
 817
 818         return simple_read_from_buffer(buffer, length, offset,
 819                                        &wblock->req_buf_size,
 820                                        sizeof(wblock->req_buf_size));
 821 }
 822
 823 static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 824 {
 825         struct wmi_ioctl_buffer __user *input =
 826                 (struct wmi_ioctl_buffer __user *) arg;
 827         struct wmi_block *wblock = filp->private_data;
 828         struct wmi_ioctl_buffer *buf = NULL;
 829         struct wmi_driver *wdriver = NULL;
 830         int ret;
 831
 832         if (_IOC_TYPE(cmd) != WMI_IOC)
 833                 return -ENOTTY;
 834
 835         /* make sure we're not calling a higher instance than exists*/
 836         if (_IOC_NR(cmd) >= wblock->gblock.instance_count)
 837                 return -EINVAL;
 838
 839         mutex_lock(&wblock->char_mutex);
 840         buf = wblock->handler_data;
 841         if (get_user(buf->length, &input->length)) {
 842                 dev_dbg(&wblock->dev.dev, "Read length from user failed\n");
 843                 ret = -EFAULT;
 844                 goto out_ioctl;
 845         }
 846         /* if it's too small, abort */
 847         if (buf->length < wblock->req_buf_size) {
 848                 dev_err(&wblock->dev.dev,
 849                         "Buffer %lld too small, need at least %lld\n",
 850                         buf->length, wblock->req_buf_size);
 851                 ret = -EINVAL;
 852                 goto out_ioctl;
 853         }
 854         /* if it's too big, warn, driver will only use what is needed */
 855         if (buf->length > wblock->req_buf_size)
 856                 dev_warn(&wblock->dev.dev,
 857                         "Buffer %lld is bigger than required %lld\n",
 858                         buf->length, wblock->req_buf_size);
 859
 860         /* copy the structure from userspace */
 861         if (copy_from_user(buf, input, wblock->req_buf_size)) {
 862                 dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n",
 863                         wblock->req_buf_size);
 864                 ret = -EFAULT;
 865                 goto out_ioctl;
 866         }
 867
 868         /* let the driver do any filtering and do the call */
 869         wdriver = container_of(wblock->dev.dev.driver,
 870                                struct wmi_driver, driver);
 871         if (!try_module_get(wdriver->driver.owner)) {
 872                 ret = -EBUSY;
 873                 goto out_ioctl;
 874         }
 875         ret = wdriver->filter_callback(&wblock->dev, cmd, buf);
 876         module_put(wdriver->driver.owner);
 877         if (ret)
 878                 goto out_ioctl;
 879
 880         /* return the result (only up to our internal buffer size) */
 881         if (copy_to_user(input, buf, wblock->req_buf_size)) {
 882                 dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n",
 883                         wblock->req_buf_size);
 884                 ret = -EFAULT;
 885         }
 886
 887 out_ioctl:
 888         mutex_unlock(&wblock->char_mutex);
 889         return ret;
 890 }
 891
 892 static const struct file_operations wmi_fops = {
 893         .owner          = THIS_MODULE,
 894         .read           = wmi_char_read,
 895         .open           = wmi_char_open,
 896         .unlocked_ioctl = wmi_ioctl,
 897         .compat_ioctl   = wmi_ioctl,
 898 };
 899
 900 static int wmi_dev_probe(struct device *dev)
 901 {
 902         struct wmi_block *wblock = dev_to_wblock(dev);
 903         struct wmi_driver *wdriver =
 904                 container_of(dev->driver, struct wmi_driver, driver);
 905         int ret = 0;
 906         int count;
 907         char *buf;
 908
 909         if (ACPI_FAILURE(wmi_method_enable(wblock, 1)))
 910                 dev_warn(dev, "failed to enable device -- probing anyway\n");
 911
 912         if (wdriver->probe) {
 913                 ret = wdriver->probe(dev_to_wdev(dev));
 914                 if (ret != 0)
 915                         goto probe_failure;
 916         }
 917
 918         /* driver wants a character device made */
 919         if (wdriver->filter_callback) {
 920                 /* check that required buffer size declared by driver or MOF */
 921                 if (!wblock->req_buf_size) {
 922                         dev_err(&wblock->dev.dev,
 923                                 "Required buffer size not set\n");
 924                         ret = -EINVAL;
 925                         goto probe_failure;
 926                 }
 927
 928                 count = get_order(wblock->req_buf_size);
 929                 wblock->handler_data = (void *)__get_free_pages(GFP_KERNEL,
 930                                                                 count);
 931                 if (!wblock->handler_data) {
 932                         ret = -ENOMEM;
 933                         goto probe_failure;
 934                 }
 935
 936                 buf = kmalloc(strlen(wdriver->driver.name) + 4, GFP_KERNEL);
 937                 if (!buf) {
 938                         ret = -ENOMEM;
 939                         goto probe_string_failure;
 940                 }
 941                 sprintf(buf, "wmi/%s", wdriver->driver.name);
 942                 wblock->char_dev.minor = MISC_DYNAMIC_MINOR;
 943                 wblock->char_dev.name = buf;
 944                 wblock->char_dev.fops = &wmi_fops;
 945                 wblock->char_dev.mode = 0444;
 946                 ret = misc_register(&wblock->char_dev);
 947                 if (ret) {
 948                         dev_warn(dev, "failed to register char dev: %d", ret);
 949                         ret = -ENOMEM;
 950                         goto probe_misc_failure;
 951                 }
 952         }
 953
 954         return 0;
 955
 956 probe_misc_failure:
 957         kfree(buf);
 958 probe_string_failure:
 959         kfree(wblock->handler_data);
 960 probe_failure:
 961         if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
 962                 dev_warn(dev, "failed to disable device\n");
 963         return ret;
 964 }
 965
 966 static int wmi_dev_remove(struct device *dev)
 967 {
 968         struct wmi_block *wblock = dev_to_wblock(dev);
 969         struct wmi_driver *wdriver =
 970                 container_of(dev->driver, struct wmi_driver, driver);
 971         int ret = 0;
 972
 973         if (wdriver->filter_callback) {
 974                 misc_deregister(&wblock->char_dev);
 975                 kfree(wblock->char_dev.name);
 976                 free_pages((unsigned long)wblock->handler_data,
 977                            get_order(wblock->req_buf_size));
 978         }
 979
 980         if (wdriver->remove)
 981                 ret = wdriver->remove(dev_to_wdev(dev));
 982
 983         if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
 984                 dev_warn(dev, "failed to disable device\n");
 985
 986         return ret;
 987 }
 988
 989 static struct class wmi_bus_class = {
 990         .name = "wmi_bus",
 991 };
 992
 993 static struct bus_type wmi_bus_type = {
 994         .name = "wmi",
 995         .dev_groups = wmi_groups,
 996         .match = wmi_dev_match,
 997         .uevent = wmi_dev_uevent,
 998         .probe = wmi_dev_probe,
 999         .remove = wmi_dev_remove,
1000 };
1001
1002 static struct device_type wmi_type_event = {
1003         .name = "event",
1004         .groups = wmi_event_groups,
1005         .release = wmi_dev_release,
1006 };
1007
1008 static struct device_type wmi_type_method = {
1009         .name = "method",
1010         .groups = wmi_method_groups,
1011         .release = wmi_dev_release,
1012 };
1013
1014 static struct device_type wmi_type_data = {
1015         .name = "data",
1016         .groups = wmi_data_groups,
1017         .release = wmi_dev_release,
1018 };
1019
1020 static int wmi_create_device(struct device *wmi_bus_dev,
1021                              const struct guid_block *gblock,
1022                              struct wmi_block *wblock,
1023                              struct acpi_device *device)
1024 {
1025         struct acpi_device_info *info;
1026         char method[5];
1027         int result;
1028
1029         if (gblock->flags & ACPI_WMI_EVENT) {
1030                 wblock->dev.dev.type = &wmi_type_event;
1031                 goto out_init;
1032         }
1033
1034         if (gblock->flags & ACPI_WMI_METHOD) {
1035                 wblock->dev.dev.type = &wmi_type_method;
1036                 mutex_init(&wblock->char_mutex);
1037                 goto out_init;
1038         }
1039
1040         /*
1041          * Data Block Query Control Method (WQxx by convention) is
1042          * required per the WMI documentation. If it is not present,
1043          * we ignore this data block.
1044          */
1045         strcpy(method, "WQ");
1046         strncat(method, wblock->gblock.object_id, 2);
1047         result = get_subobj_info(device->handle, method, &info);
1048
1049         if (result) {
1050                 dev_warn(wmi_bus_dev,
1051                          "%s data block query control method not found",
1052                          method);
1053                 return result;
1054         }
1055
1056         wblock->dev.dev.type = &wmi_type_data;
1057
1058         /*
1059          * The Microsoft documentation specifically states:
1060          *
1061          *   Data blocks registered with only a single instance
1062          *   can ignore the parameter.
1063          *
1064          * ACPICA will get mad at us if we call the method with the wrong number
1065          * of arguments, so check what our method expects.  (On some Dell
1066          * laptops, WQxx may not be a method at all.)
1067          */
1068         if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1069                 wblock->read_takes_no_args = true;
1070
1071         kfree(info);
1072
1073         strcpy(method, "WS");
1074         strncat(method, wblock->gblock.object_id, 2);
1075         result = get_subobj_info(device->handle, method, NULL);
1076
1077         if (result == 0)
1078                 wblock->dev.setable = true;
1079
1080  out_init:
1081         wblock->dev.dev.bus = &wmi_bus_type;
1082         wblock->dev.dev.parent = wmi_bus_dev;
1083
1084         dev_set_name(&wblock->dev.dev, "%pUL", gblock->guid);
1085
1086         device_initialize(&wblock->dev.dev);
1087
1088         return 0;
1089 }
1090
1091 static void wmi_free_devices(struct acpi_device *device)
1092 {
1093         struct wmi_block *wblock, *next;
1094
1095         /* Delete devices for all the GUIDs */
1096         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1097                 if (wblock->acpi_device == device) {
1098                         list_del(&wblock->list);
1099                         device_unregister(&wblock->dev.dev);
1100                 }
1101         }
1102 }
1103
1104 static bool guid_already_parsed(struct acpi_device *device,
1105                                 const u8 *guid)
1106 {
1107         struct wmi_block *wblock;
1108
1109         list_for_each_entry(wblock, &wmi_block_list, list) {
1110                 if (memcmp(wblock->gblock.guid, guid, 16) == 0) {
1111                         /*
1112                          * Because we historically didn't track the relationship
1113                          * between GUIDs and ACPI nodes, we don't know whether
1114                          * we need to suppress GUIDs that are unique on a
1115                          * given node but duplicated across nodes.
1116                          */
1117                         dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
1118                                  guid, dev_name(&wblock->acpi_device->dev));
1119                         return true;
1120                 }
1121         }
1122
1123         return false;
1124 }
1125
1126 /*
1127  * Parse the _WDG method for the GUID data blocks
1128  */
1129 static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
1130 {
1131         struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1132         const struct guid_block *gblock;
1133         struct wmi_block *wblock, *next;
1134         union acpi_object *obj;
1135         acpi_status status;
1136         int retval = 0;
1137         u32 i, total;
1138
1139         status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1140         if (ACPI_FAILURE(status))
1141                 return -ENXIO;
1142
1143         obj = (union acpi_object *) out.pointer;
1144         if (!obj)
1145                 return -ENXIO;
1146
1147         if (obj->type != ACPI_TYPE_BUFFER) {
1148                 retval = -ENXIO;
1149                 goto out_free_pointer;
1150         }
1151
1152         gblock = (const struct guid_block *)obj->buffer.pointer;
1153         total = obj->buffer.length / sizeof(struct guid_block);
1154
1155         for (i = 0; i < total; i++) {
1156                 if (debug_dump_wdg)
1157                         wmi_dump_wdg(&gblock[i]);
1158
1159                 /*
1160                  * Some WMI devices, like those for nVidia hooks, have a
1161                  * duplicate GUID. It's not clear what we should do in this
1162                  * case yet, so for now, we'll just ignore the duplicate
1163                  * for device creation.
1164                  */
1165                 if (guid_already_parsed(device, gblock[i].guid))
1166                         continue;
1167
1168                 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
1169                 if (!wblock) {
1170                         retval = -ENOMEM;
1171                         break;
1172                 }
1173
1174                 wblock->acpi_device = device;
1175                 wblock->gblock = gblock[i];
1176
1177                 retval = wmi_create_device(wmi_bus_dev, &gblock[i], wblock, device);
1178                 if (retval) {
1179                         kfree(wblock);
1180                         continue;
1181                 }
1182
1183                 list_add_tail(&wblock->list, &wmi_block_list);
1184
1185                 if (debug_event) {
1186                         wblock->handler = wmi_notify_debug;
1187                         wmi_method_enable(wblock, 1);
1188                 }
1189         }
1190
1191         /*
1192          * Now that all of the devices are created, add them to the
1193          * device tree and probe subdrivers.
1194          */
1195         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1196                 if (wblock->acpi_device != device)
1197                         continue;
1198
1199                 retval = device_add(&wblock->dev.dev);
1200                 if (retval) {
1201                         dev_err(wmi_bus_dev, "failed to register %pULL\n",
1202                                 wblock->gblock.guid);
1203                         if (debug_event)
1204                                 wmi_method_enable(wblock, 0);
1205                         list_del(&wblock->list);
1206                         put_device(&wblock->dev.dev);
1207                 }
1208         }
1209
1210 out_free_pointer:
1211         kfree(out.pointer);
1212         return retval;
1213 }
1214
1215 /*
1216  * WMI can have EmbeddedControl access regions. In which case, we just want to
1217  * hand these off to the EC driver.
1218  */
1219 static acpi_status
1220 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1221                       u32 bits, u64 *value,
1222                       void *handler_context, void *region_context)
1223 {
1224         int result = 0, i = 0;
1225         u8 temp = 0;
1226
1227         if ((address > 0xFF) || !value)
1228                 return AE_BAD_PARAMETER;
1229
1230         if (function != ACPI_READ && function != ACPI_WRITE)
1231                 return AE_BAD_PARAMETER;
1232
1233         if (bits != 8)
1234                 return AE_BAD_PARAMETER;
1235
1236         if (function == ACPI_READ) {
1237                 result = ec_read(address, &temp);
1238                 (*value) |= ((u64)temp) << i;
1239         } else {
1240                 temp = 0xff & ((*value) >> i);
1241                 result = ec_write(address, temp);
1242         }
1243
1244         switch (result) {
1245         case -EINVAL:
1246                 return AE_BAD_PARAMETER;
1247                 break;
1248         case -ENODEV:
1249                 return AE_NOT_FOUND;
1250                 break;
1251         case -ETIME:
1252                 return AE_TIME;
1253                 break;
1254         default:
1255                 return AE_OK;
1256         }
1257 }
1258
1259 static void acpi_wmi_notify_handler(acpi_handle handle, u32 event,
1260                                     void *context)
1261 {
1262         struct guid_block *block;
1263         struct wmi_block *wblock;
1264         struct list_head *p;
1265         bool found_it = false;
1266
1267         list_for_each(p, &wmi_block_list) {
1268                 wblock = list_entry(p, struct wmi_block, list);
1269                 block = &wblock->gblock;
1270
1271                 if (wblock->acpi_device->handle == handle &&
1272                     (block->flags & ACPI_WMI_EVENT) &&
1273                     (block->notify_id == event))
1274                 {
1275                         found_it = true;
1276                         break;
1277                 }
1278         }
1279
1280         if (!found_it)
1281                 return;
1282
1283         /* If a driver is bound, then notify the driver. */
1284         if (wblock->dev.dev.driver) {
1285                 struct wmi_driver *driver;
1286                 struct acpi_object_list input;
1287                 union acpi_object params[1];
1288                 struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL };
1289                 acpi_status status;
1290
1291                 driver = container_of(wblock->dev.dev.driver,
1292                                       struct wmi_driver, driver);
1293
1294                 input.count = 1;
1295                 input.pointer = params;
1296                 params[0].type = ACPI_TYPE_INTEGER;
1297                 params[0].integer.value = event;
1298
1299                 status = acpi_evaluate_object(wblock->acpi_device->handle,
1300                                               "_WED", &input, &evdata);
1301                 if (ACPI_FAILURE(status)) {
1302                         dev_warn(&wblock->dev.dev,
1303                                  "failed to get event data\n");
1304                         return;
1305                 }
1306
1307                 if (driver->notify)
1308                         driver->notify(&wblock->dev,
1309                                        (union acpi_object *)evdata.pointer);
1310
1311                 kfree(evdata.pointer);
1312         } else if (wblock->handler) {
1313                 /* Legacy handler */
1314                 wblock->handler(event, wblock->handler_data);
1315         }
1316
1317         if (debug_event) {
1318                 pr_info("DEBUG Event GUID: %pUL\n",
1319                         wblock->gblock.guid);
1320         }
1321
1322         acpi_bus_generate_netlink_event(
1323                 wblock->acpi_device->pnp.device_class,
1324                 dev_name(&wblock->dev.dev),
1325                 event, 0);
1326
1327 }
1328
1329 static int acpi_wmi_remove(struct platform_device *device)
1330 {
1331         struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev);
1332
1333         acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1334                                    acpi_wmi_notify_handler);
1335         acpi_remove_address_space_handler(acpi_device->handle,
1336                                 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
1337         wmi_free_devices(acpi_device);
1338         device_destroy(&wmi_bus_class, MKDEV(0, 0));
1339
1340         return 0;
1341 }
1342
1343 static int acpi_wmi_probe(struct platform_device *device)
1344 {
1345         struct acpi_device *acpi_device;
1346         struct device *wmi_bus_dev;
1347         acpi_status status;
1348         int error;
1349
1350         acpi_device = ACPI_COMPANION(&device->dev);
1351         if (!acpi_device) {
1352                 dev_err(&device->dev, "ACPI companion is missing\n");
1353                 return -ENODEV;
1354         }
1355
1356         status = acpi_install_address_space_handler(acpi_device->handle,
1357                                                     ACPI_ADR_SPACE_EC,
1358                                                     &acpi_wmi_ec_space_handler,
1359                                                     NULL, NULL);
1360         if (ACPI_FAILURE(status)) {
1361                 dev_err(&device->dev, "Error installing EC region handler\n");
1362                 return -ENODEV;
1363         }
1364
1365         status = acpi_install_notify_handler(acpi_device->handle,
1366                                              ACPI_DEVICE_NOTIFY,
1367                                              acpi_wmi_notify_handler,
1368                                              NULL);
1369         if (ACPI_FAILURE(status)) {
1370                 dev_err(&device->dev, "Error installing notify handler\n");
1371                 error = -ENODEV;
1372                 goto err_remove_ec_handler;
1373         }
1374
1375         wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0),
1376                                     NULL, "wmi_bus-%s", dev_name(&device->dev));
1377         if (IS_ERR(wmi_bus_dev)) {
1378                 error = PTR_ERR(wmi_bus_dev);
1379                 goto err_remove_notify_handler;
1380         }
1381         dev_set_drvdata(&device->dev, wmi_bus_dev);
1382
1383         error = parse_wdg(wmi_bus_dev, acpi_device);
1384         if (error) {
1385                 pr_err("Failed to parse WDG method\n");
1386                 goto err_remove_busdev;
1387         }
1388
1389         return 0;
1390
1391 err_remove_busdev:
1392         device_destroy(&wmi_bus_class, MKDEV(0, 0));
1393
1394 err_remove_notify_handler:
1395         acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1396                                    acpi_wmi_notify_handler);
1397
1398 err_remove_ec_handler:
1399         acpi_remove_address_space_handler(acpi_device->handle,
1400                                           ACPI_ADR_SPACE_EC,
1401                                           &acpi_wmi_ec_space_handler);
1402
1403         return error;
1404 }
1405
1406 int __must_check __wmi_driver_register(struct wmi_driver *driver,
1407                                        struct module *owner)
1408 {
1409         driver->driver.owner = owner;
1410         driver->driver.bus = &wmi_bus_type;
1411
1412         return driver_register(&driver->driver);
1413 }
1414 EXPORT_SYMBOL(__wmi_driver_register);
1415
1416 void wmi_driver_unregister(struct wmi_driver *driver)
1417 {
1418         driver_unregister(&driver->driver);
1419 }
1420 EXPORT_SYMBOL(wmi_driver_unregister);
1421
1422 static int __init acpi_wmi_init(void)
1423 {
1424         int error;
1425
1426         if (acpi_disabled)
1427                 return -ENODEV;
1428
1429         error = class_register(&wmi_bus_class);
1430         if (error)
1431                 return error;
1432
1433         error = bus_register(&wmi_bus_type);
1434         if (error)
1435                 goto err_unreg_class;
1436
1437         error = platform_driver_register(&acpi_wmi_driver);
1438         if (error) {
1439                 pr_err("Error loading mapper\n");
1440                 goto err_unreg_bus;
1441         }
1442
1443         return 0;
1444
1445 err_unreg_bus:
1446         bus_unregister(&wmi_bus_type);
1447
1448 err_unreg_class:
1449         class_unregister(&wmi_bus_class);
1450
1451         return error;
1452 }
1453
1454 static void __exit acpi_wmi_exit(void)
1455 {
1456         platform_driver_unregister(&acpi_wmi_driver);
1457         bus_unregister(&wmi_bus_type);
1458         class_unregister(&wmi_bus_class);
1459 }
1460
1461 subsys_initcall(acpi_wmi_init);
1462 module_exit(acpi_wmi_exit);