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 <[email protected]>
   6  *
   7  *  GUID parsing code from ldm.c is:
   8  *   Copyright (C) 2001,2002 Richard Russon <[email protected]>
   9  *   Copyright (c) 2001-2007 Anton Altaparmakov
  10  *   Copyright (C) 2001,2002 Jakob Kemi <[email protected]>
  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/bits.h>
  21 #include <linux/build_bug.h>
  22 #include <linux/device.h>
  23 #include <linux/init.h>
  24 #include <linux/kernel.h>
  25 #include <linux/list.h>
  26 #include <linux/miscdevice.h>
  27 #include <linux/module.h>
  28 #include <linux/platform_device.h>
  29 #include <linux/slab.h>
  30 #include <linux/sysfs.h>
  31 #include <linux/types.h>
  32 #include <linux/uaccess.h>
  33 #include <linux/uuid.h>
  34 #include <linux/wmi.h>
  35 #include <linux/fs.h>
  36 #include <uapi/linux/wmi.h>
  37
  38 MODULE_AUTHOR("Carlos Corbacho");
  39 MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
  40 MODULE_LICENSE("GPL");
  41
  42 static LIST_HEAD(wmi_block_list);
  43
  44 struct guid_block {
  45         guid_t guid;
  46         union {
  47                 char object_id[2];
  48                 struct {
  49                         unsigned char notify_id;
  50                         unsigned char reserved;
  51                 };
  52         };
  53         u8 instance_count;
  54         u8 flags;
  55 } __packed;
  56 static_assert(sizeof(typeof_member(struct guid_block, guid)) == 16);
  57 static_assert(sizeof(struct guid_block) == 20);
  58 static_assert(__alignof__(struct guid_block) == 1);
  59
  60 enum {  /* wmi_block flags */
  61         WMI_READ_TAKES_NO_ARGS,
  62         WMI_PROBED,
  63 };
  64
  65 struct wmi_block {
  66         struct wmi_device dev;
  67         struct list_head list;
  68         struct guid_block gblock;
  69         struct miscdevice char_dev;
  70         struct mutex char_mutex;
  71         struct acpi_device *acpi_device;
  72         wmi_notify_handler handler;
  73         void *handler_data;
  74         u64 req_buf_size;
  75         unsigned long flags;
  76 };
  77
  78
  79 /*
  80  * If the GUID data block is marked as expensive, we must enable and
  81  * explicitily disable data collection.
  82  */
  83 #define ACPI_WMI_EXPENSIVE   BIT(0)
  84 #define ACPI_WMI_METHOD      BIT(1)     /* GUID is a method */
  85 #define ACPI_WMI_STRING      BIT(2)     /* GUID takes & returns a string */
  86 #define ACPI_WMI_EVENT       BIT(3)     /* GUID is an event */
  87
  88 static bool debug_event;
  89 module_param(debug_event, bool, 0444);
  90 MODULE_PARM_DESC(debug_event,
  91                  "Log WMI Events [0/1]");
  92
  93 static bool debug_dump_wdg;
  94 module_param(debug_dump_wdg, bool, 0444);
  95 MODULE_PARM_DESC(debug_dump_wdg,
  96                  "Dump available WMI interfaces [0/1]");
  97
  98 static const struct acpi_device_id wmi_device_ids[] = {
  99         {"PNP0C14", 0},
 100         {"pnp0c14", 0},
 101         { }
 102 };
 103 MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
 104
 105 /* allow duplicate GUIDs as these device drivers use struct wmi_driver */
 106 static const char * const allow_duplicates[] = {
 107         "05901221-D566-11D1-B2F0-00A0C9062910", /* wmi-bmof */
 108         "8A42EA14-4F2A-FD45-6422-0087F7A7E608", /* dell-wmi-ddv */
 109         NULL
 110 };
 111
 112 /*
 113  * GUID parsing functions
 114  */
 115
 116 static acpi_status find_guid(const char *guid_string, struct wmi_block **out)
 117 {
 118         guid_t guid_input;
 119         struct wmi_block *wblock;
 120
 121         if (!guid_string)
 122                 return AE_BAD_PARAMETER;
 123
 124         if (guid_parse(guid_string, &guid_input))
 125                 return AE_BAD_PARAMETER;
 126
 127         list_for_each_entry(wblock, &wmi_block_list, list) {
 128                 if (guid_equal(&wblock->gblock.guid, &guid_input)) {
 129                         if (out)
 130                                 *out = wblock;
 131
 132                         return AE_OK;
 133                 }
 134         }
 135
 136         return AE_NOT_FOUND;
 137 }
 138
 139 static const void *find_guid_context(struct wmi_block *wblock,
 140                                      struct wmi_driver *wdriver)
 141 {
 142         const struct wmi_device_id *id;
 143
 144         id = wdriver->id_table;
 145         if (!id)
 146                 return NULL;
 147
 148         while (*id->guid_string) {
 149                 guid_t guid_input;
 150
 151                 if (guid_parse(id->guid_string, &guid_input))
 152                         continue;
 153                 if (guid_equal(&wblock->gblock.guid, &guid_input))
 154                         return id->context;
 155                 id++;
 156         }
 157         return NULL;
 158 }
 159
 160 static int get_subobj_info(acpi_handle handle, const char *pathname,
 161                            struct acpi_device_info **info)
 162 {
 163         struct acpi_device_info *dummy_info, **info_ptr;
 164         acpi_handle subobj_handle;
 165         acpi_status status;
 166
 167         status = acpi_get_handle(handle, (char *)pathname, &subobj_handle);
 168         if (status == AE_NOT_FOUND)
 169                 return -ENOENT;
 170         else if (ACPI_FAILURE(status))
 171                 return -EIO;
 172
 173         info_ptr = info ? info : &dummy_info;
 174         status = acpi_get_object_info(subobj_handle, info_ptr);
 175         if (ACPI_FAILURE(status))
 176                 return -EIO;
 177
 178         if (!info)
 179                 kfree(dummy_info);
 180
 181         return 0;
 182 }
 183
 184 static acpi_status wmi_method_enable(struct wmi_block *wblock, bool enable)
 185 {
 186         struct guid_block *block;
 187         char method[5];
 188         acpi_status status;
 189         acpi_handle handle;
 190
 191         block = &wblock->gblock;
 192         handle = wblock->acpi_device->handle;
 193
 194         snprintf(method, 5, "WE%02X", block->notify_id);
 195         status = acpi_execute_simple_method(handle, method, enable);
 196         if (status == AE_NOT_FOUND)
 197                 return AE_OK;
 198
 199         return status;
 200 }
 201
 202 #define WMI_ACPI_METHOD_NAME_SIZE 5
 203
 204 static inline void get_acpi_method_name(const struct wmi_block *wblock,
 205                                         const char method,
 206                                         char buffer[static WMI_ACPI_METHOD_NAME_SIZE])
 207 {
 208         static_assert(ARRAY_SIZE(wblock->gblock.object_id) == 2);
 209         static_assert(WMI_ACPI_METHOD_NAME_SIZE >= 5);
 210
 211         buffer[0] = 'W';
 212         buffer[1] = method;
 213         buffer[2] = wblock->gblock.object_id[0];
 214         buffer[3] = wblock->gblock.object_id[1];
 215         buffer[4] = '\0';
 216 }
 217
 218 static inline acpi_object_type get_param_acpi_type(const struct wmi_block *wblock)
 219 {
 220         if (wblock->gblock.flags & ACPI_WMI_STRING)
 221                 return ACPI_TYPE_STRING;
 222         else
 223                 return ACPI_TYPE_BUFFER;
 224 }
 225
 226 static acpi_status get_event_data(const struct wmi_block *wblock, struct acpi_buffer *out)
 227 {
 228         union acpi_object param = {
 229                 .integer = {
 230                         .type = ACPI_TYPE_INTEGER,
 231                         .value = wblock->gblock.notify_id,
 232                 }
 233         };
 234         struct acpi_object_list input = {
 235                 .count = 1,
 236                 .pointer = &param,
 237         };
 238
 239         return acpi_evaluate_object(wblock->acpi_device->handle, "_WED", &input, out);
 240 }
 241
 242 /*
 243  * Exported WMI functions
 244  */
 245
 246 /**
 247  * set_required_buffer_size - Sets the buffer size needed for performing IOCTL
 248  * @wdev: A wmi bus device from a driver
 249  * @length: Required buffer size
 250  *
 251  * Allocates memory needed for buffer, stores the buffer size in that memory
 252  */
 253 int set_required_buffer_size(struct wmi_device *wdev, u64 length)
 254 {
 255         struct wmi_block *wblock;
 256
 257         wblock = container_of(wdev, struct wmi_block, dev);
 258         wblock->req_buf_size = length;
 259
 260         return 0;
 261 }
 262 EXPORT_SYMBOL_GPL(set_required_buffer_size);
 263
 264 /**
 265  * wmi_evaluate_method - Evaluate a WMI method
 266  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 267  * @instance: Instance index
 268  * @method_id: Method ID to call
 269  * @in: Buffer containing input for the method call
 270  * @out: Empty buffer to return the method results
 271  *
 272  * Call an ACPI-WMI method
 273  */
 274 acpi_status wmi_evaluate_method(const char *guid_string, u8 instance, u32 method_id,
 275                                 const struct acpi_buffer *in, struct acpi_buffer *out)
 276 {
 277         struct wmi_block *wblock = NULL;
 278         acpi_status status;
 279
 280         status = find_guid(guid_string, &wblock);
 281         if (ACPI_FAILURE(status))
 282                 return status;
 283
 284         return wmidev_evaluate_method(&wblock->dev, instance, method_id,
 285                                       in, out);
 286 }
 287 EXPORT_SYMBOL_GPL(wmi_evaluate_method);
 288
 289 /**
 290  * wmidev_evaluate_method - Evaluate a WMI method
 291  * @wdev: A wmi bus device from a driver
 292  * @instance: Instance index
 293  * @method_id: Method ID to call
 294  * @in: Buffer containing input for the method call
 295  * @out: Empty buffer to return the method results
 296  *
 297  * Call an ACPI-WMI method
 298  */
 299 acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance, u32 method_id,
 300                                    const struct acpi_buffer *in, struct acpi_buffer *out)
 301 {
 302         struct guid_block *block;
 303         struct wmi_block *wblock;
 304         acpi_handle handle;
 305         struct acpi_object_list input;
 306         union acpi_object params[3];
 307         char method[WMI_ACPI_METHOD_NAME_SIZE];
 308
 309         wblock = container_of(wdev, struct wmi_block, dev);
 310         block = &wblock->gblock;
 311         handle = wblock->acpi_device->handle;
 312
 313         if (!(block->flags & ACPI_WMI_METHOD))
 314                 return AE_BAD_DATA;
 315
 316         if (block->instance_count <= instance)
 317                 return AE_BAD_PARAMETER;
 318
 319         input.count = 2;
 320         input.pointer = params;
 321         params[0].type = ACPI_TYPE_INTEGER;
 322         params[0].integer.value = instance;
 323         params[1].type = ACPI_TYPE_INTEGER;
 324         params[1].integer.value = method_id;
 325
 326         if (in) {
 327                 input.count = 3;
 328
 329                 params[2].type = get_param_acpi_type(wblock);
 330                 params[2].buffer.length = in->length;
 331                 params[2].buffer.pointer = in->pointer;
 332         }
 333
 334         get_acpi_method_name(wblock, 'M', method);
 335
 336         return acpi_evaluate_object(handle, method, &input, out);
 337 }
 338 EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
 339
 340 static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
 341                                  struct acpi_buffer *out)
 342 {
 343         struct guid_block *block;
 344         acpi_handle handle;
 345         acpi_status status, wc_status = AE_ERROR;
 346         struct acpi_object_list input;
 347         union acpi_object wq_params[1];
 348         char wc_method[WMI_ACPI_METHOD_NAME_SIZE];
 349         char method[WMI_ACPI_METHOD_NAME_SIZE];
 350
 351         if (!out)
 352                 return AE_BAD_PARAMETER;
 353
 354         block = &wblock->gblock;
 355         handle = wblock->acpi_device->handle;
 356
 357         if (block->instance_count <= instance)
 358                 return AE_BAD_PARAMETER;
 359
 360         /* Check GUID is a data block */
 361         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 362                 return AE_ERROR;
 363
 364         input.count = 1;
 365         input.pointer = wq_params;
 366         wq_params[0].type = ACPI_TYPE_INTEGER;
 367         wq_params[0].integer.value = instance;
 368
 369         if (instance == 0 && test_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags))
 370                 input.count = 0;
 371
 372         /*
 373          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
 374          * enable collection.
 375          */
 376         if (block->flags & ACPI_WMI_EXPENSIVE) {
 377                 get_acpi_method_name(wblock, 'C', wc_method);
 378
 379                 /*
 380                  * Some GUIDs break the specification by declaring themselves
 381                  * expensive, but have no corresponding WCxx method. So we
 382                  * should not fail if this happens.
 383                  */
 384                 wc_status = acpi_execute_simple_method(handle, wc_method, 1);
 385         }
 386
 387         get_acpi_method_name(wblock, 'Q', method);
 388         status = acpi_evaluate_object(handle, method, &input, out);
 389
 390         /*
 391          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
 392          * the WQxx method failed - we should disable collection anyway.
 393          */
 394         if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
 395                 /*
 396                  * Ignore whether this WCxx call succeeds or not since
 397                  * the previously executed WQxx method call might have
 398                  * succeeded, and returning the failing status code
 399                  * of this call would throw away the result of the WQxx
 400                  * call, potentially leaking memory.
 401                  */
 402                 acpi_execute_simple_method(handle, wc_method, 0);
 403         }
 404
 405         return status;
 406 }
 407
 408 /**
 409  * wmi_query_block - Return contents of a WMI block (deprecated)
 410  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 411  * @instance: Instance index
 412  * @out: Empty buffer to return the contents of the data block to
 413  *
 414  * Return the contents of an ACPI-WMI data block to a buffer
 415  */
 416 acpi_status wmi_query_block(const char *guid_string, u8 instance,
 417                             struct acpi_buffer *out)
 418 {
 419         struct wmi_block *wblock;
 420         acpi_status status;
 421
 422         status = find_guid(guid_string, &wblock);
 423         if (ACPI_FAILURE(status))
 424                 return status;
 425
 426         return __query_block(wblock, instance, out);
 427 }
 428 EXPORT_SYMBOL_GPL(wmi_query_block);
 429
 430 union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
 431 {
 432         struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
 433         struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
 434
 435         if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
 436                 return NULL;
 437
 438         return out.pointer;
 439 }
 440 EXPORT_SYMBOL_GPL(wmidev_block_query);
 441
 442 /**
 443  * wmi_set_block - Write to a WMI block
 444  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 445  * @instance: Instance index
 446  * @in: Buffer containing new values for the data block
 447  *
 448  * Write the contents of the input buffer to an ACPI-WMI data block
 449  */
 450 acpi_status wmi_set_block(const char *guid_string, u8 instance,
 451                           const struct acpi_buffer *in)
 452 {
 453         struct wmi_block *wblock = NULL;
 454         struct guid_block *block;
 455         acpi_handle handle;
 456         struct acpi_object_list input;
 457         union acpi_object params[2];
 458         char method[WMI_ACPI_METHOD_NAME_SIZE];
 459         acpi_status status;
 460
 461         if (!in)
 462                 return AE_BAD_DATA;
 463
 464         status = find_guid(guid_string, &wblock);
 465         if (ACPI_FAILURE(status))
 466                 return status;
 467
 468         block = &wblock->gblock;
 469         handle = wblock->acpi_device->handle;
 470
 471         if (block->instance_count <= instance)
 472                 return AE_BAD_PARAMETER;
 473
 474         /* Check GUID is a data block */
 475         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 476                 return AE_ERROR;
 477
 478         input.count = 2;
 479         input.pointer = params;
 480         params[0].type = ACPI_TYPE_INTEGER;
 481         params[0].integer.value = instance;
 482         params[1].type = get_param_acpi_type(wblock);
 483         params[1].buffer.length = in->length;
 484         params[1].buffer.pointer = in->pointer;
 485
 486         get_acpi_method_name(wblock, 'S', method);
 487
 488         return acpi_evaluate_object(handle, method, &input, NULL);
 489 }
 490 EXPORT_SYMBOL_GPL(wmi_set_block);
 491
 492 static void wmi_dump_wdg(const struct guid_block *g)
 493 {
 494         pr_info("%pUL:\n", &g->guid);
 495         if (g->flags & ACPI_WMI_EVENT)
 496                 pr_info("\tnotify_id: 0x%02X\n", g->notify_id);
 497         else
 498                 pr_info("\tobject_id: %2pE\n", g->object_id);
 499         pr_info("\tinstance_count: %d\n", g->instance_count);
 500         pr_info("\tflags: %#x", g->flags);
 501         if (g->flags) {
 502                 if (g->flags & ACPI_WMI_EXPENSIVE)
 503                         pr_cont(" ACPI_WMI_EXPENSIVE");
 504                 if (g->flags & ACPI_WMI_METHOD)
 505                         pr_cont(" ACPI_WMI_METHOD");
 506                 if (g->flags & ACPI_WMI_STRING)
 507                         pr_cont(" ACPI_WMI_STRING");
 508                 if (g->flags & ACPI_WMI_EVENT)
 509                         pr_cont(" ACPI_WMI_EVENT");
 510         }
 511         pr_cont("\n");
 512
 513 }
 514
 515 static void wmi_notify_debug(u32 value, void *context)
 516 {
 517         struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
 518         union acpi_object *obj;
 519         acpi_status status;
 520
 521         status = wmi_get_event_data(value, &response);
 522         if (status != AE_OK) {
 523                 pr_info("bad event status 0x%x\n", status);
 524                 return;
 525         }
 526
 527         obj = response.pointer;
 528         if (!obj)
 529                 return;
 530
 531         pr_info("DEBUG: event 0x%02X ", value);
 532         switch (obj->type) {
 533         case ACPI_TYPE_BUFFER:
 534                 pr_cont("BUFFER_TYPE - length %u\n", obj->buffer.length);
 535                 break;
 536         case ACPI_TYPE_STRING:
 537                 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
 538                 break;
 539         case ACPI_TYPE_INTEGER:
 540                 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
 541                 break;
 542         case ACPI_TYPE_PACKAGE:
 543                 pr_cont("PACKAGE_TYPE - %u elements\n", obj->package.count);
 544                 break;
 545         default:
 546                 pr_cont("object type 0x%X\n", obj->type);
 547         }
 548         kfree(obj);
 549 }
 550
 551 /**
 552  * wmi_install_notify_handler - Register handler for WMI events
 553  * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 554  * @handler: Function to handle notifications
 555  * @data: Data to be returned to handler when event is fired
 556  *
 557  * Register a handler for events sent to the ACPI-WMI mapper device.
 558  */
 559 acpi_status wmi_install_notify_handler(const char *guid,
 560                                        wmi_notify_handler handler,
 561                                        void *data)
 562 {
 563         struct wmi_block *block;
 564         acpi_status status = AE_NOT_EXIST;
 565         guid_t guid_input;
 566
 567         if (!guid || !handler)
 568                 return AE_BAD_PARAMETER;
 569
 570         if (guid_parse(guid, &guid_input))
 571                 return AE_BAD_PARAMETER;
 572
 573         list_for_each_entry(block, &wmi_block_list, list) {
 574                 acpi_status wmi_status;
 575
 576                 if (guid_equal(&block->gblock.guid, &guid_input)) {
 577                         if (block->handler &&
 578                             block->handler != wmi_notify_debug)
 579                                 return AE_ALREADY_ACQUIRED;
 580
 581                         block->handler = handler;
 582                         block->handler_data = data;
 583
 584                         wmi_status = wmi_method_enable(block, true);
 585                         if ((wmi_status != AE_OK) ||
 586                             ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
 587                                 status = wmi_status;
 588                 }
 589         }
 590
 591         return status;
 592 }
 593 EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
 594
 595 /**
 596  * wmi_remove_notify_handler - Unregister handler for WMI events
 597  * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 598  *
 599  * Unregister handler for events sent to the ACPI-WMI mapper device.
 600  */
 601 acpi_status wmi_remove_notify_handler(const char *guid)
 602 {
 603         struct wmi_block *block;
 604         acpi_status status = AE_NOT_EXIST;
 605         guid_t guid_input;
 606
 607         if (!guid)
 608                 return AE_BAD_PARAMETER;
 609
 610         if (guid_parse(guid, &guid_input))
 611                 return AE_BAD_PARAMETER;
 612
 613         list_for_each_entry(block, &wmi_block_list, list) {
 614                 acpi_status wmi_status;
 615
 616                 if (guid_equal(&block->gblock.guid, &guid_input)) {
 617                         if (!block->handler ||
 618                             block->handler == wmi_notify_debug)
 619                                 return AE_NULL_ENTRY;
 620
 621                         if (debug_event) {
 622                                 block->handler = wmi_notify_debug;
 623                                 status = AE_OK;
 624                         } else {
 625                                 wmi_status = wmi_method_enable(block, false);
 626                                 block->handler = NULL;
 627                                 block->handler_data = NULL;
 628                                 if ((wmi_status != AE_OK) ||
 629                                     ((wmi_status == AE_OK) &&
 630                                      (status == AE_NOT_EXIST)))
 631                                         status = wmi_status;
 632                         }
 633                 }
 634         }
 635
 636         return status;
 637 }
 638 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
 639
 640 /**
 641  * wmi_get_event_data - Get WMI data associated with an event
 642  *
 643  * @event: Event to find
 644  * @out: Buffer to hold event data. out->pointer should be freed with kfree()
 645  *
 646  * Returns extra data associated with an event in WMI.
 647  */
 648 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
 649 {
 650         struct wmi_block *wblock;
 651
 652         list_for_each_entry(wblock, &wmi_block_list, list) {
 653                 struct guid_block *gblock = &wblock->gblock;
 654
 655                 if ((gblock->flags & ACPI_WMI_EVENT) && gblock->notify_id == event)
 656                         return get_event_data(wblock, out);
 657         }
 658
 659         return AE_NOT_FOUND;
 660 }
 661 EXPORT_SYMBOL_GPL(wmi_get_event_data);
 662
 663 /**
 664  * wmi_has_guid - Check if a GUID is available
 665  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 666  *
 667  * Check if a given GUID is defined by _WDG
 668  */
 669 bool wmi_has_guid(const char *guid_string)
 670 {
 671         return ACPI_SUCCESS(find_guid(guid_string, NULL));
 672 }
 673 EXPORT_SYMBOL_GPL(wmi_has_guid);
 674
 675 /**
 676  * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID
 677  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 678  *
 679  * Find the _UID of ACPI device associated with this WMI GUID.
 680  *
 681  * Return: The ACPI _UID field value or NULL if the WMI GUID was not found
 682  */
 683 char *wmi_get_acpi_device_uid(const char *guid_string)
 684 {
 685         struct wmi_block *wblock = NULL;
 686         acpi_status status;
 687
 688         status = find_guid(guid_string, &wblock);
 689         if (ACPI_FAILURE(status))
 690                 return NULL;
 691
 692         return acpi_device_uid(wblock->acpi_device);
 693 }
 694 EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
 695
 696 #define dev_to_wblock(__dev)    container_of_const(__dev, struct wmi_block, dev.dev)
 697 #define dev_to_wdev(__dev)      container_of_const(__dev, struct wmi_device, dev)
 698
 699 static inline struct wmi_driver *drv_to_wdrv(struct device_driver *drv)
 700 {
 701         return container_of(drv, struct wmi_driver, driver);
 702 }
 703
 704 /*
 705  * sysfs interface
 706  */
 707 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 708                              char *buf)
 709 {
 710         struct wmi_block *wblock = dev_to_wblock(dev);
 711
 712         return sysfs_emit(buf, "wmi:%pUL\n", &wblock->gblock.guid);
 713 }
 714 static DEVICE_ATTR_RO(modalias);
 715
 716 static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
 717                          char *buf)
 718 {
 719         struct wmi_block *wblock = dev_to_wblock(dev);
 720
 721         return sysfs_emit(buf, "%pUL\n", &wblock->gblock.guid);
 722 }
 723 static DEVICE_ATTR_RO(guid);
 724
 725 static ssize_t instance_count_show(struct device *dev,
 726                                    struct device_attribute *attr, char *buf)
 727 {
 728         struct wmi_block *wblock = dev_to_wblock(dev);
 729
 730         return sysfs_emit(buf, "%d\n", (int)wblock->gblock.instance_count);
 731 }
 732 static DEVICE_ATTR_RO(instance_count);
 733
 734 static ssize_t expensive_show(struct device *dev,
 735                               struct device_attribute *attr, char *buf)
 736 {
 737         struct wmi_block *wblock = dev_to_wblock(dev);
 738
 739         return sysfs_emit(buf, "%d\n",
 740                           (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
 741 }
 742 static DEVICE_ATTR_RO(expensive);
 743
 744 static struct attribute *wmi_attrs[] = {
 745         &dev_attr_modalias.attr,
 746         &dev_attr_guid.attr,
 747         &dev_attr_instance_count.attr,
 748         &dev_attr_expensive.attr,
 749         NULL
 750 };
 751 ATTRIBUTE_GROUPS(wmi);
 752
 753 static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
 754                               char *buf)
 755 {
 756         struct wmi_block *wblock = dev_to_wblock(dev);
 757
 758         return sysfs_emit(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
 759 }
 760 static DEVICE_ATTR_RO(notify_id);
 761
 762 static struct attribute *wmi_event_attrs[] = {
 763         &dev_attr_notify_id.attr,
 764         NULL
 765 };
 766 ATTRIBUTE_GROUPS(wmi_event);
 767
 768 static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
 769                               char *buf)
 770 {
 771         struct wmi_block *wblock = dev_to_wblock(dev);
 772
 773         return sysfs_emit(buf, "%c%c\n", wblock->gblock.object_id[0],
 774                           wblock->gblock.object_id[1]);
 775 }
 776 static DEVICE_ATTR_RO(object_id);
 777
 778 static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
 779                             char *buf)
 780 {
 781         struct wmi_device *wdev = dev_to_wdev(dev);
 782
 783         return sysfs_emit(buf, "%d\n", (int)wdev->setable);
 784 }
 785 static DEVICE_ATTR_RO(setable);
 786
 787 static struct attribute *wmi_data_attrs[] = {
 788         &dev_attr_object_id.attr,
 789         &dev_attr_setable.attr,
 790         NULL
 791 };
 792 ATTRIBUTE_GROUPS(wmi_data);
 793
 794 static struct attribute *wmi_method_attrs[] = {
 795         &dev_attr_object_id.attr,
 796         NULL
 797 };
 798 ATTRIBUTE_GROUPS(wmi_method);
 799
 800 static int wmi_dev_uevent(const struct device *dev, struct kobj_uevent_env *env)
 801 {
 802         const struct wmi_block *wblock = dev_to_wblock(dev);
 803
 804         if (add_uevent_var(env, "MODALIAS=wmi:%pUL", &wblock->gblock.guid))
 805                 return -ENOMEM;
 806
 807         if (add_uevent_var(env, "WMI_GUID=%pUL", &wblock->gblock.guid))
 808                 return -ENOMEM;
 809
 810         return 0;
 811 }
 812
 813 static void wmi_dev_release(struct device *dev)
 814 {
 815         struct wmi_block *wblock = dev_to_wblock(dev);
 816
 817         kfree(wblock);
 818 }
 819
 820 static int wmi_dev_match(struct device *dev, struct device_driver *driver)
 821 {
 822         struct wmi_driver *wmi_driver = drv_to_wdrv(driver);
 823         struct wmi_block *wblock = dev_to_wblock(dev);
 824         const struct wmi_device_id *id = wmi_driver->id_table;
 825
 826         if (id == NULL)
 827                 return 0;
 828
 829         while (*id->guid_string) {
 830                 guid_t driver_guid;
 831
 832                 if (WARN_ON(guid_parse(id->guid_string, &driver_guid)))
 833                         continue;
 834                 if (guid_equal(&driver_guid, &wblock->gblock.guid))
 835                         return 1;
 836
 837                 id++;
 838         }
 839
 840         return 0;
 841 }
 842 static int wmi_char_open(struct inode *inode, struct file *filp)
 843 {
 844         const char *driver_name = filp->f_path.dentry->d_iname;
 845         struct wmi_block *wblock;
 846         struct wmi_block *next;
 847
 848         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
 849                 if (!wblock->dev.dev.driver)
 850                         continue;
 851                 if (strcmp(driver_name, wblock->dev.dev.driver->name) == 0) {
 852                         filp->private_data = wblock;
 853                         break;
 854                 }
 855         }
 856
 857         if (!filp->private_data)
 858                 return -ENODEV;
 859
 860         return nonseekable_open(inode, filp);
 861 }
 862
 863 static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
 864                              size_t length, loff_t *offset)
 865 {
 866         struct wmi_block *wblock = filp->private_data;
 867
 868         return simple_read_from_buffer(buffer, length, offset,
 869                                        &wblock->req_buf_size,
 870                                        sizeof(wblock->req_buf_size));
 871 }
 872
 873 static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 874 {
 875         struct wmi_ioctl_buffer __user *input =
 876                 (struct wmi_ioctl_buffer __user *) arg;
 877         struct wmi_block *wblock = filp->private_data;
 878         struct wmi_ioctl_buffer *buf;
 879         struct wmi_driver *wdriver;
 880         int ret;
 881
 882         if (_IOC_TYPE(cmd) != WMI_IOC)
 883                 return -ENOTTY;
 884
 885         /* make sure we're not calling a higher instance than exists*/
 886         if (_IOC_NR(cmd) >= wblock->gblock.instance_count)
 887                 return -EINVAL;
 888
 889         mutex_lock(&wblock->char_mutex);
 890         buf = wblock->handler_data;
 891         if (get_user(buf->length, &input->length)) {
 892                 dev_dbg(&wblock->dev.dev, "Read length from user failed\n");
 893                 ret = -EFAULT;
 894                 goto out_ioctl;
 895         }
 896         /* if it's too small, abort */
 897         if (buf->length < wblock->req_buf_size) {
 898                 dev_err(&wblock->dev.dev,
 899                         "Buffer %lld too small, need at least %lld\n",
 900                         buf->length, wblock->req_buf_size);
 901                 ret = -EINVAL;
 902                 goto out_ioctl;
 903         }
 904         /* if it's too big, warn, driver will only use what is needed */
 905         if (buf->length > wblock->req_buf_size)
 906                 dev_warn(&wblock->dev.dev,
 907                         "Buffer %lld is bigger than required %lld\n",
 908                         buf->length, wblock->req_buf_size);
 909
 910         /* copy the structure from userspace */
 911         if (copy_from_user(buf, input, wblock->req_buf_size)) {
 912                 dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n",
 913                         wblock->req_buf_size);
 914                 ret = -EFAULT;
 915                 goto out_ioctl;
 916         }
 917
 918         /* let the driver do any filtering and do the call */
 919         wdriver = drv_to_wdrv(wblock->dev.dev.driver);
 920         if (!try_module_get(wdriver->driver.owner)) {
 921                 ret = -EBUSY;
 922                 goto out_ioctl;
 923         }
 924         ret = wdriver->filter_callback(&wblock->dev, cmd, buf);
 925         module_put(wdriver->driver.owner);
 926         if (ret)
 927                 goto out_ioctl;
 928
 929         /* return the result (only up to our internal buffer size) */
 930         if (copy_to_user(input, buf, wblock->req_buf_size)) {
 931                 dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n",
 932                         wblock->req_buf_size);
 933                 ret = -EFAULT;
 934         }
 935
 936 out_ioctl:
 937         mutex_unlock(&wblock->char_mutex);
 938         return ret;
 939 }
 940
 941 static const struct file_operations wmi_fops = {
 942         .owner          = THIS_MODULE,
 943         .read           = wmi_char_read,
 944         .open           = wmi_char_open,
 945         .unlocked_ioctl = wmi_ioctl,
 946         .compat_ioctl   = compat_ptr_ioctl,
 947 };
 948
 949 static int wmi_dev_probe(struct device *dev)
 950 {
 951         struct wmi_block *wblock = dev_to_wblock(dev);
 952         struct wmi_driver *wdriver = drv_to_wdrv(dev->driver);
 953         int ret = 0;
 954         char *buf;
 955
 956         if (ACPI_FAILURE(wmi_method_enable(wblock, true)))
 957                 dev_warn(dev, "failed to enable device -- probing anyway\n");
 958
 959         if (wdriver->probe) {
 960                 ret = wdriver->probe(dev_to_wdev(dev),
 961                                 find_guid_context(wblock, wdriver));
 962                 if (ret != 0)
 963                         goto probe_failure;
 964         }
 965
 966         /* driver wants a character device made */
 967         if (wdriver->filter_callback) {
 968                 /* check that required buffer size declared by driver or MOF */
 969                 if (!wblock->req_buf_size) {
 970                         dev_err(&wblock->dev.dev,
 971                                 "Required buffer size not set\n");
 972                         ret = -EINVAL;
 973                         goto probe_failure;
 974                 }
 975
 976                 wblock->handler_data = kmalloc(wblock->req_buf_size,
 977                                                GFP_KERNEL);
 978                 if (!wblock->handler_data) {
 979                         ret = -ENOMEM;
 980                         goto probe_failure;
 981                 }
 982
 983                 buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name);
 984                 if (!buf) {
 985                         ret = -ENOMEM;
 986                         goto probe_string_failure;
 987                 }
 988                 wblock->char_dev.minor = MISC_DYNAMIC_MINOR;
 989                 wblock->char_dev.name = buf;
 990                 wblock->char_dev.fops = &wmi_fops;
 991                 wblock->char_dev.mode = 0444;
 992                 ret = misc_register(&wblock->char_dev);
 993                 if (ret) {
 994                         dev_warn(dev, "failed to register char dev: %d\n", ret);
 995                         ret = -ENOMEM;
 996                         goto probe_misc_failure;
 997                 }
 998         }
 999
1000         set_bit(WMI_PROBED, &wblock->flags);
1001         return 0;
1002
1003 probe_misc_failure:
1004         kfree(buf);
1005 probe_string_failure:
1006         kfree(wblock->handler_data);
1007 probe_failure:
1008         if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
1009                 dev_warn(dev, "failed to disable device\n");
1010         return ret;
1011 }
1012
1013 static void wmi_dev_remove(struct device *dev)
1014 {
1015         struct wmi_block *wblock = dev_to_wblock(dev);
1016         struct wmi_driver *wdriver = drv_to_wdrv(dev->driver);
1017
1018         clear_bit(WMI_PROBED, &wblock->flags);
1019
1020         if (wdriver->filter_callback) {
1021                 misc_deregister(&wblock->char_dev);
1022                 kfree(wblock->char_dev.name);
1023                 kfree(wblock->handler_data);
1024         }
1025
1026         if (wdriver->remove)
1027                 wdriver->remove(dev_to_wdev(dev));
1028
1029         if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
1030                 dev_warn(dev, "failed to disable device\n");
1031 }
1032
1033 static struct class wmi_bus_class = {
1034         .name = "wmi_bus",
1035 };
1036
1037 static struct bus_type wmi_bus_type = {
1038         .name = "wmi",
1039         .dev_groups = wmi_groups,
1040         .match = wmi_dev_match,
1041         .uevent = wmi_dev_uevent,
1042         .probe = wmi_dev_probe,
1043         .remove = wmi_dev_remove,
1044 };
1045
1046 static const struct device_type wmi_type_event = {
1047         .name = "event",
1048         .groups = wmi_event_groups,
1049         .release = wmi_dev_release,
1050 };
1051
1052 static const struct device_type wmi_type_method = {
1053         .name = "method",
1054         .groups = wmi_method_groups,
1055         .release = wmi_dev_release,
1056 };
1057
1058 static const struct device_type wmi_type_data = {
1059         .name = "data",
1060         .groups = wmi_data_groups,
1061         .release = wmi_dev_release,
1062 };
1063
1064 /*
1065  * _WDG is a static list that is only parsed at startup,
1066  * so it's safe to count entries without extra protection.
1067  */
1068 static int guid_count(const guid_t *guid)
1069 {
1070         struct wmi_block *wblock;
1071         int count = 0;
1072
1073         list_for_each_entry(wblock, &wmi_block_list, list) {
1074                 if (guid_equal(&wblock->gblock.guid, guid))
1075                         count++;
1076         }
1077
1078         return count;
1079 }
1080
1081 static int wmi_create_device(struct device *wmi_bus_dev,
1082                              struct wmi_block *wblock,
1083                              struct acpi_device *device)
1084 {
1085         struct acpi_device_info *info;
1086         char method[WMI_ACPI_METHOD_NAME_SIZE];
1087         int result;
1088         uint count;
1089
1090         if (wblock->gblock.flags & ACPI_WMI_EVENT) {
1091                 wblock->dev.dev.type = &wmi_type_event;
1092                 goto out_init;
1093         }
1094
1095         if (wblock->gblock.flags & ACPI_WMI_METHOD) {
1096                 wblock->dev.dev.type = &wmi_type_method;
1097                 mutex_init(&wblock->char_mutex);
1098                 goto out_init;
1099         }
1100
1101         /*
1102          * Data Block Query Control Method (WQxx by convention) is
1103          * required per the WMI documentation. If it is not present,
1104          * we ignore this data block.
1105          */
1106         get_acpi_method_name(wblock, 'Q', method);
1107         result = get_subobj_info(device->handle, method, &info);
1108
1109         if (result) {
1110                 dev_warn(wmi_bus_dev,
1111                          "%s data block query control method not found\n",
1112                          method);
1113                 return result;
1114         }
1115
1116         wblock->dev.dev.type = &wmi_type_data;
1117
1118         /*
1119          * The Microsoft documentation specifically states:
1120          *
1121          *   Data blocks registered with only a single instance
1122          *   can ignore the parameter.
1123          *
1124          * ACPICA will get mad at us if we call the method with the wrong number
1125          * of arguments, so check what our method expects.  (On some Dell
1126          * laptops, WQxx may not be a method at all.)
1127          */
1128         if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1129                 set_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags);
1130
1131         kfree(info);
1132
1133         get_acpi_method_name(wblock, 'S', method);
1134         result = get_subobj_info(device->handle, method, NULL);
1135
1136         if (result == 0)
1137                 wblock->dev.setable = true;
1138
1139  out_init:
1140         wblock->dev.dev.bus = &wmi_bus_type;
1141         wblock->dev.dev.parent = wmi_bus_dev;
1142
1143         count = guid_count(&wblock->gblock.guid);
1144         if (count)
1145                 dev_set_name(&wblock->dev.dev, "%pUL-%d", &wblock->gblock.guid, count);
1146         else
1147                 dev_set_name(&wblock->dev.dev, "%pUL", &wblock->gblock.guid);
1148
1149         device_initialize(&wblock->dev.dev);
1150
1151         return 0;
1152 }
1153
1154 static void wmi_free_devices(struct acpi_device *device)
1155 {
1156         struct wmi_block *wblock, *next;
1157
1158         /* Delete devices for all the GUIDs */
1159         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1160                 if (wblock->acpi_device == device) {
1161                         list_del(&wblock->list);
1162                         device_unregister(&wblock->dev.dev);
1163                 }
1164         }
1165 }
1166
1167 static bool guid_already_parsed_for_legacy(struct acpi_device *device, const guid_t *guid)
1168 {
1169         struct wmi_block *wblock;
1170
1171         list_for_each_entry(wblock, &wmi_block_list, list) {
1172                 /* skip warning and register if we know the driver will use struct wmi_driver */
1173                 for (int i = 0; allow_duplicates[i] != NULL; i++) {
1174                         guid_t tmp;
1175
1176                         if (guid_parse(allow_duplicates[i], &tmp))
1177                                 continue;
1178                         if (guid_equal(&tmp, guid))
1179                                 return false;
1180                 }
1181                 if (guid_equal(&wblock->gblock.guid, guid)) {
1182                         /*
1183                          * Because we historically didn't track the relationship
1184                          * between GUIDs and ACPI nodes, we don't know whether
1185                          * we need to suppress GUIDs that are unique on a
1186                          * given node but duplicated across nodes.
1187                          */
1188                         dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
1189                                  guid, dev_name(&wblock->acpi_device->dev));
1190                         return true;
1191                 }
1192         }
1193
1194         return false;
1195 }
1196
1197 /*
1198  * Parse the _WDG method for the GUID data blocks
1199  */
1200 static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
1201 {
1202         struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1203         const struct guid_block *gblock;
1204         struct wmi_block *wblock, *next;
1205         union acpi_object *obj;
1206         acpi_status status;
1207         int retval = 0;
1208         u32 i, total;
1209
1210         status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1211         if (ACPI_FAILURE(status))
1212                 return -ENXIO;
1213
1214         obj = out.pointer;
1215         if (!obj)
1216                 return -ENXIO;
1217
1218         if (obj->type != ACPI_TYPE_BUFFER) {
1219                 retval = -ENXIO;
1220                 goto out_free_pointer;
1221         }
1222
1223         gblock = (const struct guid_block *)obj->buffer.pointer;
1224         total = obj->buffer.length / sizeof(struct guid_block);
1225
1226         for (i = 0; i < total; i++) {
1227                 if (debug_dump_wdg)
1228                         wmi_dump_wdg(&gblock[i]);
1229
1230                 if (guid_already_parsed_for_legacy(device, &gblock[i].guid))
1231                         continue;
1232
1233                 wblock = kzalloc(sizeof(*wblock), GFP_KERNEL);
1234                 if (!wblock) {
1235                         retval = -ENOMEM;
1236                         break;
1237                 }
1238
1239                 wblock->acpi_device = device;
1240                 wblock->gblock = gblock[i];
1241
1242                 retval = wmi_create_device(wmi_bus_dev, wblock, device);
1243                 if (retval) {
1244                         kfree(wblock);
1245                         continue;
1246                 }
1247
1248                 list_add_tail(&wblock->list, &wmi_block_list);
1249
1250                 if (debug_event) {
1251                         wblock->handler = wmi_notify_debug;
1252                         wmi_method_enable(wblock, true);
1253                 }
1254         }
1255
1256         /*
1257          * Now that all of the devices are created, add them to the
1258          * device tree and probe subdrivers.
1259          */
1260         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1261                 if (wblock->acpi_device != device)
1262                         continue;
1263
1264                 retval = device_add(&wblock->dev.dev);
1265                 if (retval) {
1266                         dev_err(wmi_bus_dev, "failed to register %pUL\n",
1267                                 &wblock->gblock.guid);
1268                         if (debug_event)
1269                                 wmi_method_enable(wblock, false);
1270                         list_del(&wblock->list);
1271                         put_device(&wblock->dev.dev);
1272                 }
1273         }
1274
1275 out_free_pointer:
1276         kfree(out.pointer);
1277         return retval;
1278 }
1279
1280 /*
1281  * WMI can have EmbeddedControl access regions. In which case, we just want to
1282  * hand these off to the EC driver.
1283  */
1284 static acpi_status
1285 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1286                           u32 bits, u64 *value,
1287                           void *handler_context, void *region_context)
1288 {
1289         int result = 0, i = 0;
1290         u8 temp = 0;
1291
1292         if ((address > 0xFF) || !value)
1293                 return AE_BAD_PARAMETER;
1294
1295         if (function != ACPI_READ && function != ACPI_WRITE)
1296                 return AE_BAD_PARAMETER;
1297
1298         if (bits != 8)
1299                 return AE_BAD_PARAMETER;
1300
1301         if (function == ACPI_READ) {
1302                 result = ec_read(address, &temp);
1303                 (*value) |= ((u64)temp) << i;
1304         } else {
1305                 temp = 0xff & ((*value) >> i);
1306                 result = ec_write(address, temp);
1307         }
1308
1309         switch (result) {
1310         case -EINVAL:
1311                 return AE_BAD_PARAMETER;
1312         case -ENODEV:
1313                 return AE_NOT_FOUND;
1314         case -ETIME:
1315                 return AE_TIME;
1316         default:
1317                 return AE_OK;
1318         }
1319 }
1320
1321 static void acpi_wmi_notify_handler(acpi_handle handle, u32 event,
1322                                     void *context)
1323 {
1324         struct wmi_block *wblock = NULL, *iter;
1325
1326         list_for_each_entry(iter, &wmi_block_list, list) {
1327                 struct guid_block *block = &iter->gblock;
1328
1329                 if (iter->acpi_device->handle == handle &&
1330                     (block->flags & ACPI_WMI_EVENT) &&
1331                     (block->notify_id == event)) {
1332                         wblock = iter;
1333                         break;
1334                 }
1335         }
1336
1337         if (!wblock)
1338                 return;
1339
1340         /* If a driver is bound, then notify the driver. */
1341         if (test_bit(WMI_PROBED, &wblock->flags) && wblock->dev.dev.driver) {
1342                 struct wmi_driver *driver = drv_to_wdrv(wblock->dev.dev.driver);
1343                 struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL };
1344                 acpi_status status;
1345
1346                 if (!driver->no_notify_data) {
1347                         status = get_event_data(wblock, &evdata);
1348                         if (ACPI_FAILURE(status)) {
1349                                 dev_warn(&wblock->dev.dev, "failed to get event data\n");
1350                                 return;
1351                         }
1352                 }
1353
1354                 if (driver->notify)
1355                         driver->notify(&wblock->dev, evdata.pointer);
1356
1357                 kfree(evdata.pointer);
1358         } else if (wblock->handler) {
1359                 /* Legacy handler */
1360                 wblock->handler(event, wblock->handler_data);
1361         }
1362
1363         if (debug_event)
1364                 pr_info("DEBUG: GUID %pUL event 0x%02X\n", &wblock->gblock.guid, event);
1365
1366         acpi_bus_generate_netlink_event(
1367                 wblock->acpi_device->pnp.device_class,
1368                 dev_name(&wblock->dev.dev),
1369                 event, 0);
1370 }
1371
1372 static void acpi_wmi_remove(struct platform_device *device)
1373 {
1374         struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev);
1375
1376         acpi_remove_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY,
1377                                    acpi_wmi_notify_handler);
1378         acpi_remove_address_space_handler(acpi_device->handle,
1379                                 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
1380         wmi_free_devices(acpi_device);
1381         device_unregister(dev_get_drvdata(&device->dev));
1382 }
1383
1384 static int acpi_wmi_probe(struct platform_device *device)
1385 {
1386         struct acpi_device *acpi_device;
1387         struct device *wmi_bus_dev;
1388         acpi_status status;
1389         int error;
1390
1391         acpi_device = ACPI_COMPANION(&device->dev);
1392         if (!acpi_device) {
1393                 dev_err(&device->dev, "ACPI companion is missing\n");
1394                 return -ENODEV;
1395         }
1396
1397         status = acpi_install_address_space_handler(acpi_device->handle,
1398                                                     ACPI_ADR_SPACE_EC,
1399                                                     &acpi_wmi_ec_space_handler,
1400                                                     NULL, NULL);
1401         if (ACPI_FAILURE(status)) {
1402                 dev_err(&device->dev, "Error installing EC region handler\n");
1403                 return -ENODEV;
1404         }
1405
1406         status = acpi_install_notify_handler(acpi_device->handle,
1407                                              ACPI_ALL_NOTIFY,
1408                                              acpi_wmi_notify_handler,
1409                                              NULL);
1410         if (ACPI_FAILURE(status)) {
1411                 dev_err(&device->dev, "Error installing notify handler\n");
1412                 error = -ENODEV;
1413                 goto err_remove_ec_handler;
1414         }
1415
1416         wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0),
1417                                     NULL, "wmi_bus-%s", dev_name(&device->dev));
1418         if (IS_ERR(wmi_bus_dev)) {
1419                 error = PTR_ERR(wmi_bus_dev);
1420                 goto err_remove_notify_handler;
1421         }
1422         dev_set_drvdata(&device->dev, wmi_bus_dev);
1423
1424         error = parse_wdg(wmi_bus_dev, acpi_device);
1425         if (error) {
1426                 pr_err("Failed to parse WDG method\n");
1427                 goto err_remove_busdev;
1428         }
1429
1430         return 0;
1431
1432 err_remove_busdev:
1433         device_unregister(wmi_bus_dev);
1434
1435 err_remove_notify_handler:
1436         acpi_remove_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY,
1437                                    acpi_wmi_notify_handler);
1438
1439 err_remove_ec_handler:
1440         acpi_remove_address_space_handler(acpi_device->handle,
1441                                           ACPI_ADR_SPACE_EC,
1442                                           &acpi_wmi_ec_space_handler);
1443
1444         return error;
1445 }
1446
1447 int __must_check __wmi_driver_register(struct wmi_driver *driver,
1448                                        struct module *owner)
1449 {
1450         driver->driver.owner = owner;
1451         driver->driver.bus = &wmi_bus_type;
1452
1453         return driver_register(&driver->driver);
1454 }
1455 EXPORT_SYMBOL(__wmi_driver_register);
1456
1457 void wmi_driver_unregister(struct wmi_driver *driver)
1458 {
1459         driver_unregister(&driver->driver);
1460 }
1461 EXPORT_SYMBOL(wmi_driver_unregister);
1462
1463 static struct platform_driver acpi_wmi_driver = {
1464         .driver = {
1465                 .name = "acpi-wmi",
1466                 .acpi_match_table = wmi_device_ids,
1467         },
1468         .probe = acpi_wmi_probe,
1469         .remove_new = acpi_wmi_remove,
1470 };
1471
1472 static int __init acpi_wmi_init(void)
1473 {
1474         int error;
1475
1476         if (acpi_disabled)
1477                 return -ENODEV;
1478
1479         error = class_register(&wmi_bus_class);
1480         if (error)
1481                 return error;
1482
1483         error = bus_register(&wmi_bus_type);
1484         if (error)
1485                 goto err_unreg_class;
1486
1487         error = platform_driver_register(&acpi_wmi_driver);
1488         if (error) {
1489                 pr_err("Error loading mapper\n");
1490                 goto err_unreg_bus;
1491         }
1492
1493         return 0;
1494
1495 err_unreg_bus:
1496         bus_unregister(&wmi_bus_type);
1497
1498 err_unreg_class:
1499         class_unregister(&wmi_bus_class);
1500
1501         return error;
1502 }
1503
1504 static void __exit acpi_wmi_exit(void)
1505 {
1506         platform_driver_unregister(&acpi_wmi_driver);
1507         bus_unregister(&wmi_bus_type);
1508         class_unregister(&wmi_bus_class);
1509 }
1510
1511 subsys_initcall_sync(acpi_wmi_init);
1512 module_exit(acpi_wmi_exit);