drivers/platform/x86/wmi.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  ACPI-WMI mapping driver
   4  *
   5  *  Copyright (C) 2007-2008 Carlos Corbacho <carlos@strangeworlds.co.uk>
   6  *
   7  *  GUID parsing code from ldm.c is:
   8  *   Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
   9  *   Copyright (c) 2001-2007 Anton Altaparmakov
  10  *   Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
  11  *
  12  *  WMI bus infrastructure by Andrew Lutomirski and Darren Hart:
  13  *    Copyright (C) 2015 Andrew Lutomirski
  14  *    Copyright (C) 2017 VMware, Inc. All Rights Reserved.
  15  */
  16
  17 #define pr_fmt(fmt)     KBUILD_MODNAME ": " fmt
  18
  19 #include <linux/acpi.h>
  20 #include <linux/device.h>
  21 #include <linux/init.h>
  22 #include <linux/kernel.h>
  23 #include <linux/list.h>
  24 #include <linux/miscdevice.h>
  25 #include <linux/module.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/slab.h>
  28 #include <linux/types.h>
  29 #include <linux/uaccess.h>
  30 #include <linux/uuid.h>
  31 #include <linux/wmi.h>
  32 #include <uapi/linux/wmi.h>
  33
  34 ACPI_MODULE_NAME("wmi");
  35 MODULE_AUTHOR("Carlos Corbacho");
  36 MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
  37 MODULE_LICENSE("GPL");
  38
  39 static LIST_HEAD(wmi_block_list);
  40
  41 struct guid_block {
  42         char guid[16];
  43         union {
  44                 char object_id[2];
  45                 struct {
  46                         unsigned char notify_id;
  47                         unsigned char reserved;
  48                 };
  49         };
  50         u8 instance_count;
  51         u8 flags;
  52 };
  53
  54 struct wmi_block {
  55         struct wmi_device dev;
  56         struct list_head list;
  57         struct guid_block gblock;
  58         struct miscdevice char_dev;
  59         struct mutex char_mutex;
  60         struct acpi_device *acpi_device;
  61         wmi_notify_handler handler;
  62         void *handler_data;
  63         u64 req_buf_size;
  64
  65         bool read_takes_no_args;
  66 };
  67
  68
  69 /*
  70  * If the GUID data block is marked as expensive, we must enable and
  71  * explicitily disable data collection.
  72  */
  73 #define ACPI_WMI_EXPENSIVE   0x1
  74 #define ACPI_WMI_METHOD      0x2        /* GUID is a method */
  75 #define ACPI_WMI_STRING      0x4        /* GUID takes & returns a string */
  76 #define ACPI_WMI_EVENT       0x8        /* GUID is an event */
  77
  78 static bool debug_event;
  79 module_param(debug_event, bool, 0444);
  80 MODULE_PARM_DESC(debug_event,
  81                  "Log WMI Events [0/1]");
  82
  83 static bool debug_dump_wdg;
  84 module_param(debug_dump_wdg, bool, 0444);
  85 MODULE_PARM_DESC(debug_dump_wdg,
  86                  "Dump available WMI interfaces [0/1]");
  87
  88 static int acpi_wmi_remove(struct platform_device *device);
  89 static int acpi_wmi_probe(struct platform_device *device);
  90
  91 static const struct acpi_device_id wmi_device_ids[] = {
  92         {"PNP0C14", 0},
  93         {"pnp0c14", 0},
  94         {"", 0},
  95 };
  96 MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
  97
  98 static struct platform_driver acpi_wmi_driver = {
  99         .driver = {
 100                 .name = "acpi-wmi",
 101                 .acpi_match_table = wmi_device_ids,
 102         },
 103         .probe = acpi_wmi_probe,
 104         .remove = acpi_wmi_remove,
 105 };
 106
 107 /*
 108  * GUID parsing functions
 109  */
 110
 111 static bool find_guid(const char *guid_string, struct wmi_block **out)
 112 {
 113         uuid_le guid_input;
 114         struct wmi_block *wblock;
 115         struct guid_block *block;
 116
 117         if (uuid_le_to_bin(guid_string, &guid_input))
 118                 return false;
 119
 120         list_for_each_entry(wblock, &wmi_block_list, list) {
 121                 block = &wblock->gblock;
 122
 123                 if (memcmp(block->guid, &guid_input, 16) == 0) {
 124                         if (out)
 125                                 *out = wblock;
 126                         return true;
 127                 }
 128         }
 129         return false;
 130 }
 131
 132 static int get_subobj_info(acpi_handle handle, const char *pathname,
 133                            struct acpi_device_info **info)
 134 {
 135         struct acpi_device_info *dummy_info, **info_ptr;
 136         acpi_handle subobj_handle;
 137         acpi_status status;
 138
 139         status = acpi_get_handle(handle, (char *)pathname, &subobj_handle);
 140         if (status == AE_NOT_FOUND)
 141                 return -ENOENT;
 142         else if (ACPI_FAILURE(status))
 143                 return -EIO;
 144
 145         info_ptr = info ? info : &dummy_info;
 146         status = acpi_get_object_info(subobj_handle, info_ptr);
 147         if (ACPI_FAILURE(status))
 148                 return -EIO;
 149
 150         if (!info)
 151                 kfree(dummy_info);
 152
 153         return 0;
 154 }
 155
 156 static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable)
 157 {
 158         struct guid_block *block = NULL;
 159         char method[5];
 160         acpi_status status;
 161         acpi_handle handle;
 162
 163         block = &wblock->gblock;
 164         handle = wblock->acpi_device->handle;
 165
 166         snprintf(method, 5, "WE%02X", block->notify_id);
 167         status = acpi_execute_simple_method(handle, method, enable);
 168
 169         if (status != AE_OK && status != AE_NOT_FOUND)
 170                 return status;
 171         else
 172                 return AE_OK;
 173 }
 174
 175 /*
 176  * Exported WMI functions
 177  */
 178
 179 /**
 180  * set_required_buffer_size - Sets the buffer size needed for performing IOCTL
 181  * @wdev: A wmi bus device from a driver
 182  * @instance: Instance index
 183  *
 184  * Allocates memory needed for buffer, stores the buffer size in that memory
 185  */
 186 int set_required_buffer_size(struct wmi_device *wdev, u64 length)
 187 {
 188         struct wmi_block *wblock;
 189
 190         wblock = container_of(wdev, struct wmi_block, dev);
 191         wblock->req_buf_size = length;
 192
 193         return 0;
 194 }
 195 EXPORT_SYMBOL_GPL(set_required_buffer_size);
 196
 197 /**
 198  * wmi_evaluate_method - Evaluate a WMI method
 199  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 200  * @instance: Instance index
 201  * @method_id: Method ID to call
 202  * &in: Buffer containing input for the method call
 203  * &out: Empty buffer to return the method results
 204  *
 205  * Call an ACPI-WMI method
 206  */
 207 acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
 208 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
 209 {
 210         struct wmi_block *wblock = NULL;
 211
 212         if (!find_guid(guid_string, &wblock))
 213                 return AE_ERROR;
 214         return wmidev_evaluate_method(&wblock->dev, instance, method_id,
 215                                       in, out);
 216 }
 217 EXPORT_SYMBOL_GPL(wmi_evaluate_method);
 218
 219 /**
 220  * wmidev_evaluate_method - Evaluate a WMI method
 221  * @wdev: A wmi bus device from a driver
 222  * @instance: Instance index
 223  * @method_id: Method ID to call
 224  * &in: Buffer containing input for the method call
 225  * &out: Empty buffer to return the method results
 226  *
 227  * Call an ACPI-WMI method
 228  */
 229 acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance,
 230         u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
 231 {
 232         struct guid_block *block = NULL;
 233         struct wmi_block *wblock = NULL;
 234         acpi_handle handle;
 235         acpi_status status;
 236         struct acpi_object_list input;
 237         union acpi_object params[3];
 238         char method[5] = "WM";
 239
 240         wblock = container_of(wdev, struct wmi_block, dev);
 241         block = &wblock->gblock;
 242         handle = wblock->acpi_device->handle;
 243
 244         if (!(block->flags & ACPI_WMI_METHOD))
 245                 return AE_BAD_DATA;
 246
 247         if (block->instance_count <= instance)
 248                 return AE_BAD_PARAMETER;
 249
 250         input.count = 2;
 251         input.pointer = params;
 252         params[0].type = ACPI_TYPE_INTEGER;
 253         params[0].integer.value = instance;
 254         params[1].type = ACPI_TYPE_INTEGER;
 255         params[1].integer.value = method_id;
 256
 257         if (in) {
 258                 input.count = 3;
 259
 260                 if (block->flags & ACPI_WMI_STRING) {
 261                         params[2].type = ACPI_TYPE_STRING;
 262                 } else {
 263                         params[2].type = ACPI_TYPE_BUFFER;
 264                 }
 265                 params[2].buffer.length = in->length;
 266                 params[2].buffer.pointer = in->pointer;
 267         }
 268
 269         strncat(method, block->object_id, 2);
 270
 271         status = acpi_evaluate_object(handle, method, &input, out);
 272
 273         return status;
 274 }
 275 EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
 276
 277 static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
 278                                  struct acpi_buffer *out)
 279 {
 280         struct guid_block *block = NULL;
 281         acpi_handle handle;
 282         acpi_status status, wc_status = AE_ERROR;
 283         struct acpi_object_list input;
 284         union acpi_object wq_params[1];
 285         char method[5];
 286         char wc_method[5] = "WC";
 287
 288         if (!out)
 289                 return AE_BAD_PARAMETER;
 290
 291         block = &wblock->gblock;
 292         handle = wblock->acpi_device->handle;
 293
 294         if (block->instance_count <= instance)
 295                 return AE_BAD_PARAMETER;
 296
 297         /* Check GUID is a data block */
 298         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 299                 return AE_ERROR;
 300
 301         input.count = 1;
 302         input.pointer = wq_params;
 303         wq_params[0].type = ACPI_TYPE_INTEGER;
 304         wq_params[0].integer.value = instance;
 305
 306         if (instance == 0 && wblock->read_takes_no_args)
 307                 input.count = 0;
 308
 309         /*
 310          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
 311          * enable collection.
 312          */
 313         if (block->flags & ACPI_WMI_EXPENSIVE) {
 314                 strncat(wc_method, block->object_id, 2);
 315
 316                 /*
 317                  * Some GUIDs break the specification by declaring themselves
 318                  * expensive, but have no corresponding WCxx method. So we
 319                  * should not fail if this happens.
 320                  */
 321                 if (acpi_has_method(handle, wc_method))
 322                         wc_status = acpi_execute_simple_method(handle,
 323                                                                 wc_method, 1);
 324         }
 325
 326         strcpy(method, "WQ");
 327         strncat(method, block->object_id, 2);
 328
 329         status = acpi_evaluate_object(handle, method, &input, out);
 330
 331         /*
 332          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
 333          * the WQxx method failed - we should disable collection anyway.
 334          */
 335         if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
 336                 status = acpi_execute_simple_method(handle, wc_method, 0);
 337         }
 338
 339         return status;
 340 }
 341
 342 /**
 343  * wmi_query_block - Return contents of a WMI block (deprecated)
 344  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 345  * @instance: Instance index
 346  * &out: Empty buffer to return the contents of the data block to
 347  *
 348  * Return the contents of an ACPI-WMI data block to a buffer
 349  */
 350 acpi_status wmi_query_block(const char *guid_string, u8 instance,
 351                             struct acpi_buffer *out)
 352 {
 353         struct wmi_block *wblock;
 354
 355         if (!guid_string)
 356                 return AE_BAD_PARAMETER;
 357
 358         if (!find_guid(guid_string, &wblock))
 359                 return AE_ERROR;
 360
 361         return __query_block(wblock, instance, out);
 362 }
 363 EXPORT_SYMBOL_GPL(wmi_query_block);
 364
 365 union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
 366 {
 367         struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
 368         struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
 369
 370         if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
 371                 return NULL;
 372
 373         return (union acpi_object *)out.pointer;
 374 }
 375 EXPORT_SYMBOL_GPL(wmidev_block_query);
 376
 377 /**
 378  * wmi_set_block - Write to a WMI block
 379  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 380  * @instance: Instance index
 381  * &in: Buffer containing new values for the data block
 382  *
 383  * Write the contents of the input buffer to an ACPI-WMI data block
 384  */
 385 acpi_status wmi_set_block(const char *guid_string, u8 instance,
 386                           const struct acpi_buffer *in)
 387 {
 388         struct guid_block *block = NULL;
 389         struct wmi_block *wblock = NULL;
 390         acpi_handle handle;
 391         struct acpi_object_list input;
 392         union acpi_object params[2];
 393         char method[5] = "WS";
 394
 395         if (!guid_string || !in)
 396                 return AE_BAD_DATA;
 397
 398         if (!find_guid(guid_string, &wblock))
 399                 return AE_ERROR;
 400
 401         block = &wblock->gblock;
 402         handle = wblock->acpi_device->handle;
 403
 404         if (block->instance_count <= instance)
 405                 return AE_BAD_PARAMETER;
 406
 407         /* Check GUID is a data block */
 408         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 409                 return AE_ERROR;
 410
 411         input.count = 2;
 412         input.pointer = params;
 413         params[0].type = ACPI_TYPE_INTEGER;
 414         params[0].integer.value = instance;
 415
 416         if (block->flags & ACPI_WMI_STRING) {
 417                 params[1].type = ACPI_TYPE_STRING;
 418         } else {
 419                 params[1].type = ACPI_TYPE_BUFFER;
 420         }
 421         params[1].buffer.length = in->length;
 422         params[1].buffer.pointer = in->pointer;
 423
 424         strncat(method, block->object_id, 2);
 425
 426         return acpi_evaluate_object(handle, method, &input, NULL);
 427 }
 428 EXPORT_SYMBOL_GPL(wmi_set_block);
 429
 430 static void wmi_dump_wdg(const struct guid_block *g)
 431 {
 432         pr_info("%pUL:\n", g->guid);
 433         if (g->flags & ACPI_WMI_EVENT)
 434                 pr_info("\tnotify_id: 0x%02X\n", g->notify_id);
 435         else
 436                 pr_info("\tobject_id: %2pE\n", g->object_id);
 437         pr_info("\tinstance_count: %d\n", g->instance_count);
 438         pr_info("\tflags: %#x", g->flags);
 439         if (g->flags) {
 440                 if (g->flags & ACPI_WMI_EXPENSIVE)
 441                         pr_cont(" ACPI_WMI_EXPENSIVE");
 442                 if (g->flags & ACPI_WMI_METHOD)
 443                         pr_cont(" ACPI_WMI_METHOD");
 444                 if (g->flags & ACPI_WMI_STRING)
 445                         pr_cont(" ACPI_WMI_STRING");
 446                 if (g->flags & ACPI_WMI_EVENT)
 447                         pr_cont(" ACPI_WMI_EVENT");
 448         }
 449         pr_cont("\n");
 450
 451 }
 452
 453 static void wmi_notify_debug(u32 value, void *context)
 454 {
 455         struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
 456         union acpi_object *obj;
 457         acpi_status status;
 458
 459         status = wmi_get_event_data(value, &response);
 460         if (status != AE_OK) {
 461                 pr_info("bad event status 0x%x\n", status);
 462                 return;
 463         }
 464
 465         obj = (union acpi_object *)response.pointer;
 466
 467         if (!obj)
 468                 return;
 469
 470         pr_info("DEBUG Event ");
 471         switch(obj->type) {
 472         case ACPI_TYPE_BUFFER:
 473                 pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
 474                 break;
 475         case ACPI_TYPE_STRING:
 476                 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
 477                 break;
 478         case ACPI_TYPE_INTEGER:
 479                 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
 480                 break;
 481         case ACPI_TYPE_PACKAGE:
 482                 pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
 483                 break;
 484         default:
 485                 pr_cont("object type 0x%X\n", obj->type);
 486         }
 487         kfree(obj);
 488 }
 489
 490 /**
 491  * wmi_install_notify_handler - Register handler for WMI events
 492  * @handler: Function to handle notifications
 493  * @data: Data to be returned to handler when event is fired
 494  *
 495  * Register a handler for events sent to the ACPI-WMI mapper device.
 496  */
 497 acpi_status wmi_install_notify_handler(const char *guid,
 498 wmi_notify_handler handler, void *data)
 499 {
 500         struct wmi_block *block;
 501         acpi_status status = AE_NOT_EXIST;
 502         uuid_le guid_input;
 503
 504         if (!guid || !handler)
 505                 return AE_BAD_PARAMETER;
 506
 507         if (uuid_le_to_bin(guid, &guid_input))
 508                 return AE_BAD_PARAMETER;
 509
 510         list_for_each_entry(block, &wmi_block_list, list) {
 511                 acpi_status wmi_status;
 512
 513                 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
 514                         if (block->handler &&
 515                             block->handler != wmi_notify_debug)
 516                                 return AE_ALREADY_ACQUIRED;
 517
 518                         block->handler = handler;
 519                         block->handler_data = data;
 520
 521                         wmi_status = wmi_method_enable(block, 1);
 522                         if ((wmi_status != AE_OK) ||
 523                             ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
 524                                 status = wmi_status;
 525                 }
 526         }
 527
 528         return status;
 529 }
 530 EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
 531
 532 /**
 533  * wmi_uninstall_notify_handler - Unregister handler for WMI events
 534  *
 535  * Unregister handler for events sent to the ACPI-WMI mapper device.
 536  */
 537 acpi_status wmi_remove_notify_handler(const char *guid)
 538 {
 539         struct wmi_block *block;
 540         acpi_status status = AE_NOT_EXIST;
 541         uuid_le guid_input;
 542
 543         if (!guid)
 544                 return AE_BAD_PARAMETER;
 545
 546         if (uuid_le_to_bin(guid, &guid_input))
 547                 return AE_BAD_PARAMETER;
 548
 549         list_for_each_entry(block, &wmi_block_list, list) {
 550                 acpi_status wmi_status;
 551
 552                 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
 553                         if (!block->handler ||
 554                             block->handler == wmi_notify_debug)
 555                                 return AE_NULL_ENTRY;
 556
 557                         if (debug_event) {
 558                                 block->handler = wmi_notify_debug;
 559                                 status = AE_OK;
 560                         } else {
 561                                 wmi_status = wmi_method_enable(block, 0);
 562                                 block->handler = NULL;
 563                                 block->handler_data = NULL;
 564                                 if ((wmi_status != AE_OK) ||
 565                                     ((wmi_status == AE_OK) &&
 566                                      (status == AE_NOT_EXIST)))
 567                                         status = wmi_status;
 568                         }
 569                 }
 570         }
 571
 572         return status;
 573 }
 574 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
 575
 576 /**
 577  * wmi_get_event_data - Get WMI data associated with an event
 578  *
 579  * @event: Event to find
 580  * @out: Buffer to hold event data. out->pointer should be freed with kfree()
 581  *
 582  * Returns extra data associated with an event in WMI.
 583  */
 584 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
 585 {
 586         struct acpi_object_list input;
 587         union acpi_object params[1];
 588         struct guid_block *gblock;
 589         struct wmi_block *wblock;
 590
 591         input.count = 1;
 592         input.pointer = params;
 593         params[0].type = ACPI_TYPE_INTEGER;
 594         params[0].integer.value = event;
 595
 596         list_for_each_entry(wblock, &wmi_block_list, list) {
 597                 gblock = &wblock->gblock;
 598
 599                 if ((gblock->flags & ACPI_WMI_EVENT) &&
 600                         (gblock->notify_id == event))
 601                         return acpi_evaluate_object(wblock->acpi_device->handle,
 602                                 "_WED", &input, out);
 603         }
 604
 605         return AE_NOT_FOUND;
 606 }
 607 EXPORT_SYMBOL_GPL(wmi_get_event_data);
 608
 609 /**
 610  * wmi_has_guid - Check if a GUID is available
 611  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 612  *
 613  * Check if a given GUID is defined by _WDG
 614  */
 615 bool wmi_has_guid(const char *guid_string)
 616 {
 617         return find_guid(guid_string, NULL);
 618 }
 619 EXPORT_SYMBOL_GPL(wmi_has_guid);
 620
 621 static struct wmi_block *dev_to_wblock(struct device *dev)
 622 {
 623         return container_of(dev, struct wmi_block, dev.dev);
 624 }
 625
 626 static struct wmi_device *dev_to_wdev(struct device *dev)
 627 {
 628         return container_of(dev, struct wmi_device, dev);
 629 }
 630
 631 /*
 632  * sysfs interface
 633  */
 634 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 635                              char *buf)
 636 {
 637         struct wmi_block *wblock = dev_to_wblock(dev);
 638
 639         return sprintf(buf, "wmi:%pUL\n", wblock->gblock.guid);
 640 }
 641 static DEVICE_ATTR_RO(modalias);
 642
 643 static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
 644                          char *buf)
 645 {
 646         struct wmi_block *wblock = dev_to_wblock(dev);
 647
 648         return sprintf(buf, "%pUL\n", wblock->gblock.guid);
 649 }
 650 static DEVICE_ATTR_RO(guid);
 651
 652 static ssize_t instance_count_show(struct device *dev,
 653                                    struct device_attribute *attr, char *buf)
 654 {
 655         struct wmi_block *wblock = dev_to_wblock(dev);
 656
 657         return sprintf(buf, "%d\n", (int)wblock->gblock.instance_count);
 658 }
 659 static DEVICE_ATTR_RO(instance_count);
 660
 661 static ssize_t expensive_show(struct device *dev,
 662                               struct device_attribute *attr, char *buf)
 663 {
 664         struct wmi_block *wblock = dev_to_wblock(dev);
 665
 666         return sprintf(buf, "%d\n",
 667                        (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
 668 }
 669 static DEVICE_ATTR_RO(expensive);
 670
 671 static struct attribute *wmi_attrs[] = {
 672         &dev_attr_modalias.attr,
 673         &dev_attr_guid.attr,
 674         &dev_attr_instance_count.attr,
 675         &dev_attr_expensive.attr,
 676         NULL,
 677 };
 678 ATTRIBUTE_GROUPS(wmi);
 679
 680 static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
 681                               char *buf)
 682 {
 683         struct wmi_block *wblock = dev_to_wblock(dev);
 684
 685         return sprintf(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
 686 }
 687 static DEVICE_ATTR_RO(notify_id);
 688
 689 static struct attribute *wmi_event_attrs[] = {
 690         &dev_attr_notify_id.attr,
 691         NULL,
 692 };
 693 ATTRIBUTE_GROUPS(wmi_event);
 694
 695 static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
 696                               char *buf)
 697 {
 698         struct wmi_block *wblock = dev_to_wblock(dev);
 699
 700         return sprintf(buf, "%c%c\n", wblock->gblock.object_id[0],
 701                        wblock->gblock.object_id[1]);
 702 }
 703 static DEVICE_ATTR_RO(object_id);
 704
 705 static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
 706                             char *buf)
 707 {
 708         struct wmi_device *wdev = dev_to_wdev(dev);
 709
 710         return sprintf(buf, "%d\n", (int)wdev->setable);
 711 }
 712 static DEVICE_ATTR_RO(setable);
 713
 714 static struct attribute *wmi_data_attrs[] = {
 715         &dev_attr_object_id.attr,
 716         &dev_attr_setable.attr,
 717         NULL,
 718 };
 719 ATTRIBUTE_GROUPS(wmi_data);
 720
 721 static struct attribute *wmi_method_attrs[] = {
 722         &dev_attr_object_id.attr,
 723         NULL,
 724 };
 725 ATTRIBUTE_GROUPS(wmi_method);
 726
 727 static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 728 {
 729         struct wmi_block *wblock = dev_to_wblock(dev);
 730
 731         if (add_uevent_var(env, "MODALIAS=wmi:%pUL", wblock->gblock.guid))
 732                 return -ENOMEM;
 733
 734         if (add_uevent_var(env, "WMI_GUID=%pUL", wblock->gblock.guid))
 735                 return -ENOMEM;
 736
 737         return 0;
 738 }
 739
 740 static void wmi_dev_release(struct device *dev)
 741 {
 742         struct wmi_block *wblock = dev_to_wblock(dev);
 743
 744         kfree(wblock);
 745 }
 746
 747 static int wmi_dev_match(struct device *dev, struct device_driver *driver)
 748 {
 749         struct wmi_driver *wmi_driver =
 750                 container_of(driver, struct wmi_driver, driver);
 751         struct wmi_block *wblock = dev_to_wblock(dev);
 752         const struct wmi_device_id *id = wmi_driver->id_table;
 753
 754         if (id == NULL)
 755                 return 0;
 756
 757         while (*id->guid_string) {
 758                 uuid_le driver_guid;
 759
 760                 if (WARN_ON(uuid_le_to_bin(id->guid_string, &driver_guid)))
 761                         continue;
 762                 if (!memcmp(&driver_guid, wblock->gblock.guid, 16))
 763                         return 1;
 764
 765                 id++;
 766         }
 767
 768         return 0;
 769 }
 770 static int wmi_char_open(struct inode *inode, struct file *filp)
 771 {
 772         const char *driver_name = filp->f_path.dentry->d_iname;
 773         struct wmi_block *wblock = NULL;
 774         struct wmi_block *next = NULL;
 775
 776         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
 777                 if (!wblock->dev.dev.driver)
 778                         continue;
 779                 if (strcmp(driver_name, wblock->dev.dev.driver->name) == 0) {
 780                         filp->private_data = wblock;
 781                         break;
 782                 }
 783         }
 784
 785         if (!filp->private_data)
 786                 return -ENODEV;
 787
 788         return nonseekable_open(inode, filp);
 789 }
 790
 791 static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
 792         size_t length, loff_t *offset)
 793 {
 794         struct wmi_block *wblock = filp->private_data;
 795
 796         return simple_read_from_buffer(buffer, length, offset,
 797                                        &wblock->req_buf_size,
 798                                        sizeof(wblock->req_buf_size));
 799 }
 800
 801 static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 802 {
 803         struct wmi_ioctl_buffer __user *input =
 804                 (struct wmi_ioctl_buffer __user *) arg;
 805         struct wmi_block *wblock = filp->private_data;
 806         struct wmi_ioctl_buffer *buf = NULL;
 807         struct wmi_driver *wdriver = NULL;
 808         int ret;
 809
 810         if (_IOC_TYPE(cmd) != WMI_IOC)
 811                 return -ENOTTY;
 812
 813         /* make sure we're not calling a higher instance than exists*/
 814         if (_IOC_NR(cmd) >= wblock->gblock.instance_count)
 815                 return -EINVAL;
 816
 817         mutex_lock(&wblock->char_mutex);
 818         buf = wblock->handler_data;
 819         if (get_user(buf->length, &input->length)) {
 820                 dev_dbg(&wblock->dev.dev, "Read length from user failed\n");
 821                 ret = -EFAULT;
 822                 goto out_ioctl;
 823         }
 824         /* if it's too small, abort */
 825         if (buf->length < wblock->req_buf_size) {
 826                 dev_err(&wblock->dev.dev,
 827                         "Buffer %lld too small, need at least %lld\n",
 828                         buf->length, wblock->req_buf_size);
 829                 ret = -EINVAL;
 830                 goto out_ioctl;
 831         }
 832         /* if it's too big, warn, driver will only use what is needed */
 833         if (buf->length > wblock->req_buf_size)
 834                 dev_warn(&wblock->dev.dev,
 835                         "Buffer %lld is bigger than required %lld\n",
 836                         buf->length, wblock->req_buf_size);
 837
 838         /* copy the structure from userspace */
 839         if (copy_from_user(buf, input, wblock->req_buf_size)) {
 840                 dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n",
 841                         wblock->req_buf_size);
 842                 ret = -EFAULT;
 843                 goto out_ioctl;
 844         }
 845
 846         /* let the driver do any filtering and do the call */
 847         wdriver = container_of(wblock->dev.dev.driver,
 848                                struct wmi_driver, driver);
 849         if (!try_module_get(wdriver->driver.owner)) {
 850                 ret = -EBUSY;
 851                 goto out_ioctl;
 852         }
 853         ret = wdriver->filter_callback(&wblock->dev, cmd, buf);
 854         module_put(wdriver->driver.owner);
 855         if (ret)
 856                 goto out_ioctl;
 857
 858         /* return the result (only up to our internal buffer size) */
 859         if (copy_to_user(input, buf, wblock->req_buf_size)) {
 860                 dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n",
 861                         wblock->req_buf_size);
 862                 ret = -EFAULT;
 863         }
 864
 865 out_ioctl:
 866         mutex_unlock(&wblock->char_mutex);
 867         return ret;
 868 }
 869
 870 static const struct file_operations wmi_fops = {
 871         .owner          = THIS_MODULE,
 872         .read           = wmi_char_read,
 873         .open           = wmi_char_open,
 874         .unlocked_ioctl = wmi_ioctl,
 875         .compat_ioctl   = wmi_ioctl,
 876 };
 877
 878 static int wmi_dev_probe(struct device *dev)
 879 {
 880         struct wmi_block *wblock = dev_to_wblock(dev);
 881         struct wmi_driver *wdriver =
 882                 container_of(dev->driver, struct wmi_driver, driver);
 883         int ret = 0;
 884         char *buf;
 885
 886         if (ACPI_FAILURE(wmi_method_enable(wblock, 1)))
 887                 dev_warn(dev, "failed to enable device -- probing anyway\n");
 888
 889         if (wdriver->probe) {
 890                 ret = wdriver->probe(dev_to_wdev(dev));
 891                 if (ret != 0)
 892                         goto probe_failure;
 893         }
 894
 895         /* driver wants a character device made */
 896         if (wdriver->filter_callback) {
 897                 /* check that required buffer size declared by driver or MOF */
 898                 if (!wblock->req_buf_size) {
 899                         dev_err(&wblock->dev.dev,
 900                                 "Required buffer size not set\n");
 901                         ret = -EINVAL;
 902                         goto probe_failure;
 903                 }
 904
 905                 wblock->handler_data = kmalloc(wblock->req_buf_size,
 906                                                GFP_KERNEL);
 907                 if (!wblock->handler_data) {
 908                         ret = -ENOMEM;
 909                         goto probe_failure;
 910                 }
 911
 912                 buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name);
 913                 if (!buf) {
 914                         ret = -ENOMEM;
 915                         goto probe_string_failure;
 916                 }
 917                 wblock->char_dev.minor = MISC_DYNAMIC_MINOR;
 918                 wblock->char_dev.name = buf;
 919                 wblock->char_dev.fops = &wmi_fops;
 920                 wblock->char_dev.mode = 0444;
 921                 ret = misc_register(&wblock->char_dev);
 922                 if (ret) {
 923                         dev_warn(dev, "failed to register char dev: %d\n", ret);
 924                         ret = -ENOMEM;
 925                         goto probe_misc_failure;
 926                 }
 927         }
 928
 929         return 0;
 930
 931 probe_misc_failure:
 932         kfree(buf);
 933 probe_string_failure:
 934         kfree(wblock->handler_data);
 935 probe_failure:
 936         if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
 937                 dev_warn(dev, "failed to disable device\n");
 938         return ret;
 939 }
 940
 941 static int wmi_dev_remove(struct device *dev)
 942 {
 943         struct wmi_block *wblock = dev_to_wblock(dev);
 944         struct wmi_driver *wdriver =
 945                 container_of(dev->driver, struct wmi_driver, driver);
 946         int ret = 0;
 947
 948         if (wdriver->filter_callback) {
 949                 misc_deregister(&wblock->char_dev);
 950                 kfree(wblock->char_dev.name);
 951                 kfree(wblock->handler_data);
 952         }
 953
 954         if (wdriver->remove)
 955                 ret = wdriver->remove(dev_to_wdev(dev));
 956
 957         if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
 958                 dev_warn(dev, "failed to disable device\n");
 959
 960         return ret;
 961 }
 962
 963 static struct class wmi_bus_class = {
 964         .name = "wmi_bus",
 965 };
 966
 967 static struct bus_type wmi_bus_type = {
 968         .name = "wmi",
 969         .dev_groups = wmi_groups,
 970         .match = wmi_dev_match,
 971         .uevent = wmi_dev_uevent,
 972         .probe = wmi_dev_probe,
 973         .remove = wmi_dev_remove,
 974 };
 975
 976 static const struct device_type wmi_type_event = {
 977         .name = "event",
 978         .groups = wmi_event_groups,
 979         .release = wmi_dev_release,
 980 };
 981
 982 static const struct device_type wmi_type_method = {
 983         .name = "method",
 984         .groups = wmi_method_groups,
 985         .release = wmi_dev_release,
 986 };
 987
 988 static const struct device_type wmi_type_data = {
 989         .name = "data",
 990         .groups = wmi_data_groups,
 991         .release = wmi_dev_release,
 992 };
 993
 994 static int wmi_create_device(struct device *wmi_bus_dev,
 995                              const struct guid_block *gblock,
 996                              struct wmi_block *wblock,
 997                              struct acpi_device *device)
 998 {
 999         struct acpi_device_info *info;
1000         char method[5];
1001         int result;
1002
1003         if (gblock->flags & ACPI_WMI_EVENT) {
1004                 wblock->dev.dev.type = &wmi_type_event;
1005                 goto out_init;
1006         }
1007
1008         if (gblock->flags & ACPI_WMI_METHOD) {
1009                 wblock->dev.dev.type = &wmi_type_method;
1010                 mutex_init(&wblock->char_mutex);
1011                 goto out_init;
1012         }
1013
1014         /*
1015          * Data Block Query Control Method (WQxx by convention) is
1016          * required per the WMI documentation. If it is not present,
1017          * we ignore this data block.
1018          */
1019         strcpy(method, "WQ");
1020         strncat(method, wblock->gblock.object_id, 2);
1021         result = get_subobj_info(device->handle, method, &info);
1022
1023         if (result) {
1024                 dev_warn(wmi_bus_dev,
1025                          "%s data block query control method not found\n",
1026                          method);
1027                 return result;
1028         }
1029
1030         wblock->dev.dev.type = &wmi_type_data;
1031
1032         /*
1033          * The Microsoft documentation specifically states:
1034          *
1035          *   Data blocks registered with only a single instance
1036          *   can ignore the parameter.
1037          *
1038          * ACPICA will get mad at us if we call the method with the wrong number
1039          * of arguments, so check what our method expects.  (On some Dell
1040          * laptops, WQxx may not be a method at all.)
1041          */
1042         if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1043                 wblock->read_takes_no_args = true;
1044
1045         kfree(info);
1046
1047         strcpy(method, "WS");
1048         strncat(method, wblock->gblock.object_id, 2);
1049         result = get_subobj_info(device->handle, method, NULL);
1050
1051         if (result == 0)
1052                 wblock->dev.setable = true;
1053
1054  out_init:
1055         wblock->dev.dev.bus = &wmi_bus_type;
1056         wblock->dev.dev.parent = wmi_bus_dev;
1057
1058         dev_set_name(&wblock->dev.dev, "%pUL", gblock->guid);
1059
1060         device_initialize(&wblock->dev.dev);
1061
1062         return 0;
1063 }
1064
1065 static void wmi_free_devices(struct acpi_device *device)
1066 {
1067         struct wmi_block *wblock, *next;
1068
1069         /* Delete devices for all the GUIDs */
1070         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1071                 if (wblock->acpi_device == device) {
1072                         list_del(&wblock->list);
1073                         device_unregister(&wblock->dev.dev);
1074                 }
1075         }
1076 }
1077
1078 static bool guid_already_parsed(struct acpi_device *device,
1079                                 const u8 *guid)
1080 {
1081         struct wmi_block *wblock;
1082
1083         list_for_each_entry(wblock, &wmi_block_list, list) {
1084                 if (memcmp(wblock->gblock.guid, guid, 16) == 0) {
1085                         /*
1086                          * Because we historically didn't track the relationship
1087                          * between GUIDs and ACPI nodes, we don't know whether
1088                          * we need to suppress GUIDs that are unique on a
1089                          * given node but duplicated across nodes.
1090                          */
1091                         dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
1092                                  guid, dev_name(&wblock->acpi_device->dev));
1093                         return true;
1094                 }
1095         }
1096
1097         return false;
1098 }
1099
1100 /*
1101  * Parse the _WDG method for the GUID data blocks
1102  */
1103 static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
1104 {
1105         struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1106         const struct guid_block *gblock;
1107         struct wmi_block *wblock, *next;
1108         union acpi_object *obj;
1109         acpi_status status;
1110         int retval = 0;
1111         u32 i, total;
1112
1113         status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1114         if (ACPI_FAILURE(status))
1115                 return -ENXIO;
1116
1117         obj = (union acpi_object *) out.pointer;
1118         if (!obj)
1119                 return -ENXIO;
1120
1121         if (obj->type != ACPI_TYPE_BUFFER) {
1122                 retval = -ENXIO;
1123                 goto out_free_pointer;
1124         }
1125
1126         gblock = (const struct guid_block *)obj->buffer.pointer;
1127         total = obj->buffer.length / sizeof(struct guid_block);
1128
1129         for (i = 0; i < total; i++) {
1130                 if (debug_dump_wdg)
1131                         wmi_dump_wdg(&gblock[i]);
1132
1133                 /*
1134                  * Some WMI devices, like those for nVidia hooks, have a
1135                  * duplicate GUID. It's not clear what we should do in this
1136                  * case yet, so for now, we'll just ignore the duplicate
1137                  * for device creation.
1138                  */
1139                 if (guid_already_parsed(device, gblock[i].guid))
1140                         continue;
1141
1142                 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
1143                 if (!wblock) {
1144                         retval = -ENOMEM;
1145                         break;
1146                 }
1147
1148                 wblock->acpi_device = device;
1149                 wblock->gblock = gblock[i];
1150
1151                 retval = wmi_create_device(wmi_bus_dev, &gblock[i], wblock, device);
1152                 if (retval) {
1153                         kfree(wblock);
1154                         continue;
1155                 }
1156
1157                 list_add_tail(&wblock->list, &wmi_block_list);
1158
1159                 if (debug_event) {
1160                         wblock->handler = wmi_notify_debug;
1161                         wmi_method_enable(wblock, 1);
1162                 }
1163         }
1164
1165         /*
1166          * Now that all of the devices are created, add them to the
1167          * device tree and probe subdrivers.
1168          */
1169         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1170                 if (wblock->acpi_device != device)
1171                         continue;
1172
1173                 retval = device_add(&wblock->dev.dev);
1174                 if (retval) {
1175                         dev_err(wmi_bus_dev, "failed to register %pUL\n",
1176                                 wblock->gblock.guid);
1177                         if (debug_event)
1178                                 wmi_method_enable(wblock, 0);
1179                         list_del(&wblock->list);
1180                         put_device(&wblock->dev.dev);
1181                 }
1182         }
1183
1184 out_free_pointer:
1185         kfree(out.pointer);
1186         return retval;
1187 }
1188
1189 /*
1190  * WMI can have EmbeddedControl access regions. In which case, we just want to
1191  * hand these off to the EC driver.
1192  */
1193 static acpi_status
1194 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1195                       u32 bits, u64 *value,
1196                       void *handler_context, void *region_context)
1197 {
1198         int result = 0, i = 0;
1199         u8 temp = 0;
1200
1201         if ((address > 0xFF) || !value)
1202                 return AE_BAD_PARAMETER;
1203
1204         if (function != ACPI_READ && function != ACPI_WRITE)
1205                 return AE_BAD_PARAMETER;
1206
1207         if (bits != 8)
1208                 return AE_BAD_PARAMETER;
1209
1210         if (function == ACPI_READ) {
1211                 result = ec_read(address, &temp);
1212                 (*value) |= ((u64)temp) << i;
1213         } else {
1214                 temp = 0xff & ((*value) >> i);
1215                 result = ec_write(address, temp);
1216         }
1217
1218         switch (result) {
1219         case -EINVAL:
1220                 return AE_BAD_PARAMETER;
1221                 break;
1222         case -ENODEV:
1223                 return AE_NOT_FOUND;
1224                 break;
1225         case -ETIME:
1226                 return AE_TIME;
1227                 break;
1228         default:
1229                 return AE_OK;
1230         }
1231 }
1232
1233 static void acpi_wmi_notify_handler(acpi_handle handle, u32 event,
1234                                     void *context)
1235 {
1236         struct guid_block *block;
1237         struct wmi_block *wblock;
1238         bool found_it = false;
1239
1240         list_for_each_entry(wblock, &wmi_block_list, list) {
1241                 block = &wblock->gblock;
1242
1243                 if (wblock->acpi_device->handle == handle &&
1244                     (block->flags & ACPI_WMI_EVENT) &&
1245                     (block->notify_id == event))
1246                 {
1247                         found_it = true;
1248                         break;
1249                 }
1250         }
1251
1252         if (!found_it)
1253                 return;
1254
1255         /* If a driver is bound, then notify the driver. */
1256         if (wblock->dev.dev.driver) {
1257                 struct wmi_driver *driver;
1258                 struct acpi_object_list input;
1259                 union acpi_object params[1];
1260                 struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL };
1261                 acpi_status status;
1262
1263                 driver = container_of(wblock->dev.dev.driver,
1264                                       struct wmi_driver, driver);
1265
1266                 input.count = 1;
1267                 input.pointer = params;
1268                 params[0].type = ACPI_TYPE_INTEGER;
1269                 params[0].integer.value = event;
1270
1271                 status = acpi_evaluate_object(wblock->acpi_device->handle,
1272                                               "_WED", &input, &evdata);
1273                 if (ACPI_FAILURE(status)) {
1274                         dev_warn(&wblock->dev.dev,
1275                                  "failed to get event data\n");
1276                         return;
1277                 }
1278
1279                 if (driver->notify)
1280                         driver->notify(&wblock->dev,
1281                                        (union acpi_object *)evdata.pointer);
1282
1283                 kfree(evdata.pointer);
1284         } else if (wblock->handler) {
1285                 /* Legacy handler */
1286                 wblock->handler(event, wblock->handler_data);
1287         }
1288
1289         if (debug_event) {
1290                 pr_info("DEBUG Event GUID: %pUL\n",
1291                         wblock->gblock.guid);
1292         }
1293
1294         acpi_bus_generate_netlink_event(
1295                 wblock->acpi_device->pnp.device_class,
1296                 dev_name(&wblock->dev.dev),
1297                 event, 0);
1298
1299 }
1300
1301 static int acpi_wmi_remove(struct platform_device *device)
1302 {
1303         struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev);
1304
1305         acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1306                                    acpi_wmi_notify_handler);
1307         acpi_remove_address_space_handler(acpi_device->handle,
1308                                 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
1309         wmi_free_devices(acpi_device);
1310         device_destroy(&wmi_bus_class, MKDEV(0, 0));
1311
1312         return 0;
1313 }
1314
1315 static int acpi_wmi_probe(struct platform_device *device)
1316 {
1317         struct acpi_device *acpi_device;
1318         struct device *wmi_bus_dev;
1319         acpi_status status;
1320         int error;
1321
1322         acpi_device = ACPI_COMPANION(&device->dev);
1323         if (!acpi_device) {
1324                 dev_err(&device->dev, "ACPI companion is missing\n");
1325                 return -ENODEV;
1326         }
1327
1328         status = acpi_install_address_space_handler(acpi_device->handle,
1329                                                     ACPI_ADR_SPACE_EC,
1330                                                     &acpi_wmi_ec_space_handler,
1331                                                     NULL, NULL);
1332         if (ACPI_FAILURE(status)) {
1333                 dev_err(&device->dev, "Error installing EC region handler\n");
1334                 return -ENODEV;
1335         }
1336
1337         status = acpi_install_notify_handler(acpi_device->handle,
1338                                              ACPI_DEVICE_NOTIFY,
1339                                              acpi_wmi_notify_handler,
1340                                              NULL);
1341         if (ACPI_FAILURE(status)) {
1342                 dev_err(&device->dev, "Error installing notify handler\n");
1343                 error = -ENODEV;
1344                 goto err_remove_ec_handler;
1345         }
1346
1347         wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0),
1348                                     NULL, "wmi_bus-%s", dev_name(&device->dev));
1349         if (IS_ERR(wmi_bus_dev)) {
1350                 error = PTR_ERR(wmi_bus_dev);
1351                 goto err_remove_notify_handler;
1352         }
1353         dev_set_drvdata(&device->dev, wmi_bus_dev);
1354
1355         error = parse_wdg(wmi_bus_dev, acpi_device);
1356         if (error) {
1357                 pr_err("Failed to parse WDG method\n");
1358                 goto err_remove_busdev;
1359         }
1360
1361         return 0;
1362
1363 err_remove_busdev:
1364         device_destroy(&wmi_bus_class, MKDEV(0, 0));
1365
1366 err_remove_notify_handler:
1367         acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1368                                    acpi_wmi_notify_handler);
1369
1370 err_remove_ec_handler:
1371         acpi_remove_address_space_handler(acpi_device->handle,
1372                                           ACPI_ADR_SPACE_EC,
1373                                           &acpi_wmi_ec_space_handler);
1374
1375         return error;
1376 }
1377
1378 int __must_check __wmi_driver_register(struct wmi_driver *driver,
1379                                        struct module *owner)
1380 {
1381         driver->driver.owner = owner;
1382         driver->driver.bus = &wmi_bus_type;
1383
1384         return driver_register(&driver->driver);
1385 }
1386 EXPORT_SYMBOL(__wmi_driver_register);
1387
1388 void wmi_driver_unregister(struct wmi_driver *driver)
1389 {
1390         driver_unregister(&driver->driver);
1391 }
1392 EXPORT_SYMBOL(wmi_driver_unregister);
1393
1394 static int __init acpi_wmi_init(void)
1395 {
1396         int error;
1397
1398         if (acpi_disabled)
1399                 return -ENODEV;
1400
1401         error = class_register(&wmi_bus_class);
1402         if (error)
1403                 return error;
1404
1405         error = bus_register(&wmi_bus_type);
1406         if (error)
1407                 goto err_unreg_class;
1408
1409         error = platform_driver_register(&acpi_wmi_driver);
1410         if (error) {
1411                 pr_err("Error loading mapper\n");
1412                 goto err_unreg_bus;
1413         }
1414
1415         return 0;
1416
1417 err_unreg_bus:
1418         bus_unregister(&wmi_bus_type);
1419
1420 err_unreg_class:
1421         class_unregister(&wmi_bus_class);
1422
1423         return error;
1424 }
1425
1426 static void __exit acpi_wmi_exit(void)
1427 {
1428         platform_driver_unregister(&acpi_wmi_driver);
1429         bus_unregister(&wmi_bus_type);
1430         class_unregister(&wmi_bus_class);
1431 }
1432
1433 subsys_initcall_sync(acpi_wmi_init);
1434 module_exit(acpi_wmi_exit);