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 static struct wmi_block *dev_to_wblock(struct device *dev)
 697 {
 698         return container_of(dev, struct wmi_block, dev.dev);
 699 }
 700
 701 static struct wmi_device *dev_to_wdev(struct device *dev)
 702 {
 703         return container_of(dev, struct wmi_device, dev);
 704 }
 705
 706 static inline struct wmi_driver *drv_to_wdrv(struct device_driver *drv)
 707 {
 708         return container_of(drv, struct wmi_driver, driver);
 709 }
 710
 711 /*
 712  * sysfs interface
 713  */
 714 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 715                              char *buf)
 716 {
 717         struct wmi_block *wblock = dev_to_wblock(dev);
 718
 719         return sysfs_emit(buf, "wmi:%pUL\n", &wblock->gblock.guid);
 720 }
 721 static DEVICE_ATTR_RO(modalias);
 722
 723 static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
 724                          char *buf)
 725 {
 726         struct wmi_block *wblock = dev_to_wblock(dev);
 727
 728         return sysfs_emit(buf, "%pUL\n", &wblock->gblock.guid);
 729 }
 730 static DEVICE_ATTR_RO(guid);
 731
 732 static ssize_t instance_count_show(struct device *dev,
 733                                    struct device_attribute *attr, char *buf)
 734 {
 735         struct wmi_block *wblock = dev_to_wblock(dev);
 736
 737         return sysfs_emit(buf, "%d\n", (int)wblock->gblock.instance_count);
 738 }
 739 static DEVICE_ATTR_RO(instance_count);
 740
 741 static ssize_t expensive_show(struct device *dev,
 742                               struct device_attribute *attr, char *buf)
 743 {
 744         struct wmi_block *wblock = dev_to_wblock(dev);
 745
 746         return sysfs_emit(buf, "%d\n",
 747                           (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
 748 }
 749 static DEVICE_ATTR_RO(expensive);
 750
 751 static struct attribute *wmi_attrs[] = {
 752         &dev_attr_modalias.attr,
 753         &dev_attr_guid.attr,
 754         &dev_attr_instance_count.attr,
 755         &dev_attr_expensive.attr,
 756         NULL
 757 };
 758 ATTRIBUTE_GROUPS(wmi);
 759
 760 static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
 761                               char *buf)
 762 {
 763         struct wmi_block *wblock = dev_to_wblock(dev);
 764
 765         return sysfs_emit(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
 766 }
 767 static DEVICE_ATTR_RO(notify_id);
 768
 769 static struct attribute *wmi_event_attrs[] = {
 770         &dev_attr_notify_id.attr,
 771         NULL
 772 };
 773 ATTRIBUTE_GROUPS(wmi_event);
 774
 775 static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
 776                               char *buf)
 777 {
 778         struct wmi_block *wblock = dev_to_wblock(dev);
 779
 780         return sysfs_emit(buf, "%c%c\n", wblock->gblock.object_id[0],
 781                           wblock->gblock.object_id[1]);
 782 }
 783 static DEVICE_ATTR_RO(object_id);
 784
 785 static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
 786                             char *buf)
 787 {
 788         struct wmi_device *wdev = dev_to_wdev(dev);
 789
 790         return sysfs_emit(buf, "%d\n", (int)wdev->setable);
 791 }
 792 static DEVICE_ATTR_RO(setable);
 793
 794 static struct attribute *wmi_data_attrs[] = {
 795         &dev_attr_object_id.attr,
 796         &dev_attr_setable.attr,
 797         NULL
 798 };
 799 ATTRIBUTE_GROUPS(wmi_data);
 800
 801 static struct attribute *wmi_method_attrs[] = {
 802         &dev_attr_object_id.attr,
 803         NULL
 804 };
 805 ATTRIBUTE_GROUPS(wmi_method);
 806
 807 static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 808 {
 809         struct wmi_block *wblock = dev_to_wblock(dev);
 810
 811         if (add_uevent_var(env, "MODALIAS=wmi:%pUL", &wblock->gblock.guid))
 812                 return -ENOMEM;
 813
 814         if (add_uevent_var(env, "WMI_GUID=%pUL", &wblock->gblock.guid))
 815                 return -ENOMEM;
 816
 817         return 0;
 818 }
 819
 820 static void wmi_dev_release(struct device *dev)
 821 {
 822         struct wmi_block *wblock = dev_to_wblock(dev);
 823
 824         kfree(wblock);
 825 }
 826
 827 static int wmi_dev_match(struct device *dev, struct device_driver *driver)
 828 {
 829         struct wmi_driver *wmi_driver = drv_to_wdrv(driver);
 830         struct wmi_block *wblock = dev_to_wblock(dev);
 831         const struct wmi_device_id *id = wmi_driver->id_table;
 832
 833         if (id == NULL)
 834                 return 0;
 835
 836         while (*id->guid_string) {
 837                 guid_t driver_guid;
 838
 839                 if (WARN_ON(guid_parse(id->guid_string, &driver_guid)))
 840                         continue;
 841                 if (guid_equal(&driver_guid, &wblock->gblock.guid))
 842                         return 1;
 843
 844                 id++;
 845         }
 846
 847         return 0;
 848 }
 849 static int wmi_char_open(struct inode *inode, struct file *filp)
 850 {
 851         const char *driver_name = filp->f_path.dentry->d_iname;
 852         struct wmi_block *wblock;
 853         struct wmi_block *next;
 854
 855         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
 856                 if (!wblock->dev.dev.driver)
 857                         continue;
 858                 if (strcmp(driver_name, wblock->dev.dev.driver->name) == 0) {
 859                         filp->private_data = wblock;
 860                         break;
 861                 }
 862         }
 863
 864         if (!filp->private_data)
 865                 return -ENODEV;
 866
 867         return nonseekable_open(inode, filp);
 868 }
 869
 870 static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
 871                              size_t length, loff_t *offset)
 872 {
 873         struct wmi_block *wblock = filp->private_data;
 874
 875         return simple_read_from_buffer(buffer, length, offset,
 876                                        &wblock->req_buf_size,
 877                                        sizeof(wblock->req_buf_size));
 878 }
 879
 880 static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 881 {
 882         struct wmi_ioctl_buffer __user *input =
 883                 (struct wmi_ioctl_buffer __user *) arg;
 884         struct wmi_block *wblock = filp->private_data;
 885         struct wmi_ioctl_buffer *buf;
 886         struct wmi_driver *wdriver;
 887         int ret;
 888
 889         if (_IOC_TYPE(cmd) != WMI_IOC)
 890                 return -ENOTTY;
 891
 892         /* make sure we're not calling a higher instance than exists*/
 893         if (_IOC_NR(cmd) >= wblock->gblock.instance_count)
 894                 return -EINVAL;
 895
 896         mutex_lock(&wblock->char_mutex);
 897         buf = wblock->handler_data;
 898         if (get_user(buf->length, &input->length)) {
 899                 dev_dbg(&wblock->dev.dev, "Read length from user failed\n");
 900                 ret = -EFAULT;
 901                 goto out_ioctl;
 902         }
 903         /* if it's too small, abort */
 904         if (buf->length < wblock->req_buf_size) {
 905                 dev_err(&wblock->dev.dev,
 906                         "Buffer %lld too small, need at least %lld\n",
 907                         buf->length, wblock->req_buf_size);
 908                 ret = -EINVAL;
 909                 goto out_ioctl;
 910         }
 911         /* if it's too big, warn, driver will only use what is needed */
 912         if (buf->length > wblock->req_buf_size)
 913                 dev_warn(&wblock->dev.dev,
 914                         "Buffer %lld is bigger than required %lld\n",
 915                         buf->length, wblock->req_buf_size);
 916
 917         /* copy the structure from userspace */
 918         if (copy_from_user(buf, input, wblock->req_buf_size)) {
 919                 dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n",
 920                         wblock->req_buf_size);
 921                 ret = -EFAULT;
 922                 goto out_ioctl;
 923         }
 924
 925         /* let the driver do any filtering and do the call */
 926         wdriver = drv_to_wdrv(wblock->dev.dev.driver);
 927         if (!try_module_get(wdriver->driver.owner)) {
 928                 ret = -EBUSY;
 929                 goto out_ioctl;
 930         }
 931         ret = wdriver->filter_callback(&wblock->dev, cmd, buf);
 932         module_put(wdriver->driver.owner);
 933         if (ret)
 934                 goto out_ioctl;
 935
 936         /* return the result (only up to our internal buffer size) */
 937         if (copy_to_user(input, buf, wblock->req_buf_size)) {
 938                 dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n",
 939                         wblock->req_buf_size);
 940                 ret = -EFAULT;
 941         }
 942
 943 out_ioctl:
 944         mutex_unlock(&wblock->char_mutex);
 945         return ret;
 946 }
 947
 948 static const struct file_operations wmi_fops = {
 949         .owner          = THIS_MODULE,
 950         .read           = wmi_char_read,
 951         .open           = wmi_char_open,
 952         .unlocked_ioctl = wmi_ioctl,
 953         .compat_ioctl   = compat_ptr_ioctl,
 954 };
 955
 956 static int wmi_dev_probe(struct device *dev)
 957 {
 958         struct wmi_block *wblock = dev_to_wblock(dev);
 959         struct wmi_driver *wdriver = drv_to_wdrv(dev->driver);
 960         int ret = 0;
 961         char *buf;
 962
 963         if (ACPI_FAILURE(wmi_method_enable(wblock, true)))
 964                 dev_warn(dev, "failed to enable device -- probing anyway\n");
 965
 966         if (wdriver->probe) {
 967                 ret = wdriver->probe(dev_to_wdev(dev),
 968                                 find_guid_context(wblock, wdriver));
 969                 if (ret != 0)
 970                         goto probe_failure;
 971         }
 972
 973         /* driver wants a character device made */
 974         if (wdriver->filter_callback) {
 975                 /* check that required buffer size declared by driver or MOF */
 976                 if (!wblock->req_buf_size) {
 977                         dev_err(&wblock->dev.dev,
 978                                 "Required buffer size not set\n");
 979                         ret = -EINVAL;
 980                         goto probe_failure;
 981                 }
 982
 983                 wblock->handler_data = kmalloc(wblock->req_buf_size,
 984                                                GFP_KERNEL);
 985                 if (!wblock->handler_data) {
 986                         ret = -ENOMEM;
 987                         goto probe_failure;
 988                 }
 989
 990                 buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name);
 991                 if (!buf) {
 992                         ret = -ENOMEM;
 993                         goto probe_string_failure;
 994                 }
 995                 wblock->char_dev.minor = MISC_DYNAMIC_MINOR;
 996                 wblock->char_dev.name = buf;
 997                 wblock->char_dev.fops = &wmi_fops;
 998                 wblock->char_dev.mode = 0444;
 999                 ret = misc_register(&wblock->char_dev);
1000                 if (ret) {
1001                         dev_warn(dev, "failed to register char dev: %d\n", ret);
1002                         ret = -ENOMEM;
1003                         goto probe_misc_failure;
1004                 }
1005         }
1006
1007         set_bit(WMI_PROBED, &wblock->flags);
1008         return 0;
1009
1010 probe_misc_failure:
1011         kfree(buf);
1012 probe_string_failure:
1013         kfree(wblock->handler_data);
1014 probe_failure:
1015         if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
1016                 dev_warn(dev, "failed to disable device\n");
1017         return ret;
1018 }
1019
1020 static void wmi_dev_remove(struct device *dev)
1021 {
1022         struct wmi_block *wblock = dev_to_wblock(dev);
1023         struct wmi_driver *wdriver = drv_to_wdrv(dev->driver);
1024
1025         clear_bit(WMI_PROBED, &wblock->flags);
1026
1027         if (wdriver->filter_callback) {
1028                 misc_deregister(&wblock->char_dev);
1029                 kfree(wblock->char_dev.name);
1030                 kfree(wblock->handler_data);
1031         }
1032
1033         if (wdriver->remove)
1034                 wdriver->remove(dev_to_wdev(dev));
1035
1036         if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
1037                 dev_warn(dev, "failed to disable device\n");
1038 }
1039
1040 static struct class wmi_bus_class = {
1041         .name = "wmi_bus",
1042 };
1043
1044 static struct bus_type wmi_bus_type = {
1045         .name = "wmi",
1046         .dev_groups = wmi_groups,
1047         .match = wmi_dev_match,
1048         .uevent = wmi_dev_uevent,
1049         .probe = wmi_dev_probe,
1050         .remove = wmi_dev_remove,
1051 };
1052
1053 static const struct device_type wmi_type_event = {
1054         .name = "event",
1055         .groups = wmi_event_groups,
1056         .release = wmi_dev_release,
1057 };
1058
1059 static const struct device_type wmi_type_method = {
1060         .name = "method",
1061         .groups = wmi_method_groups,
1062         .release = wmi_dev_release,
1063 };
1064
1065 static const struct device_type wmi_type_data = {
1066         .name = "data",
1067         .groups = wmi_data_groups,
1068         .release = wmi_dev_release,
1069 };
1070
1071 /*
1072  * _WDG is a static list that is only parsed at startup,
1073  * so it's safe to count entries without extra protection.
1074  */
1075 static int guid_count(const guid_t *guid)
1076 {
1077         struct wmi_block *wblock;
1078         int count = 0;
1079
1080         list_for_each_entry(wblock, &wmi_block_list, list) {
1081                 if (guid_equal(&wblock->gblock.guid, guid))
1082                         count++;
1083         }
1084
1085         return count;
1086 }
1087
1088 static int wmi_create_device(struct device *wmi_bus_dev,
1089                              struct wmi_block *wblock,
1090                              struct acpi_device *device)
1091 {
1092         struct acpi_device_info *info;
1093         char method[WMI_ACPI_METHOD_NAME_SIZE];
1094         int result;
1095         uint count;
1096
1097         if (wblock->gblock.flags & ACPI_WMI_EVENT) {
1098                 wblock->dev.dev.type = &wmi_type_event;
1099                 goto out_init;
1100         }
1101
1102         if (wblock->gblock.flags & ACPI_WMI_METHOD) {
1103                 wblock->dev.dev.type = &wmi_type_method;
1104                 mutex_init(&wblock->char_mutex);
1105                 goto out_init;
1106         }
1107
1108         /*
1109          * Data Block Query Control Method (WQxx by convention) is
1110          * required per the WMI documentation. If it is not present,
1111          * we ignore this data block.
1112          */
1113         get_acpi_method_name(wblock, 'Q', method);
1114         result = get_subobj_info(device->handle, method, &info);
1115
1116         if (result) {
1117                 dev_warn(wmi_bus_dev,
1118                          "%s data block query control method not found\n",
1119                          method);
1120                 return result;
1121         }
1122
1123         wblock->dev.dev.type = &wmi_type_data;
1124
1125         /*
1126          * The Microsoft documentation specifically states:
1127          *
1128          *   Data blocks registered with only a single instance
1129          *   can ignore the parameter.
1130          *
1131          * ACPICA will get mad at us if we call the method with the wrong number
1132          * of arguments, so check what our method expects.  (On some Dell
1133          * laptops, WQxx may not be a method at all.)
1134          */
1135         if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1136                 set_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags);
1137
1138         kfree(info);
1139
1140         get_acpi_method_name(wblock, 'S', method);
1141         result = get_subobj_info(device->handle, method, NULL);
1142
1143         if (result == 0)
1144                 wblock->dev.setable = true;
1145
1146  out_init:
1147         wblock->dev.dev.bus = &wmi_bus_type;
1148         wblock->dev.dev.parent = wmi_bus_dev;
1149
1150         count = guid_count(&wblock->gblock.guid);
1151         if (count)
1152                 dev_set_name(&wblock->dev.dev, "%pUL-%d", &wblock->gblock.guid, count);
1153         else
1154                 dev_set_name(&wblock->dev.dev, "%pUL", &wblock->gblock.guid);
1155
1156         device_initialize(&wblock->dev.dev);
1157
1158         return 0;
1159 }
1160
1161 static void wmi_free_devices(struct acpi_device *device)
1162 {
1163         struct wmi_block *wblock, *next;
1164
1165         /* Delete devices for all the GUIDs */
1166         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1167                 if (wblock->acpi_device == device) {
1168                         list_del(&wblock->list);
1169                         device_unregister(&wblock->dev.dev);
1170                 }
1171         }
1172 }
1173
1174 static bool guid_already_parsed_for_legacy(struct acpi_device *device, const guid_t *guid)
1175 {
1176         struct wmi_block *wblock;
1177
1178         list_for_each_entry(wblock, &wmi_block_list, list) {
1179                 /* skip warning and register if we know the driver will use struct wmi_driver */
1180                 for (int i = 0; allow_duplicates[i] != NULL; i++) {
1181                         guid_t tmp;
1182
1183                         if (guid_parse(allow_duplicates[i], &tmp))
1184                                 continue;
1185                         if (guid_equal(&tmp, guid))
1186                                 return false;
1187                 }
1188                 if (guid_equal(&wblock->gblock.guid, guid)) {
1189                         /*
1190                          * Because we historically didn't track the relationship
1191                          * between GUIDs and ACPI nodes, we don't know whether
1192                          * we need to suppress GUIDs that are unique on a
1193                          * given node but duplicated across nodes.
1194                          */
1195                         dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
1196                                  guid, dev_name(&wblock->acpi_device->dev));
1197                         return true;
1198                 }
1199         }
1200
1201         return false;
1202 }
1203
1204 /*
1205  * Parse the _WDG method for the GUID data blocks
1206  */
1207 static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
1208 {
1209         struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1210         const struct guid_block *gblock;
1211         struct wmi_block *wblock, *next;
1212         union acpi_object *obj;
1213         acpi_status status;
1214         int retval = 0;
1215         u32 i, total;
1216
1217         status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1218         if (ACPI_FAILURE(status))
1219                 return -ENXIO;
1220
1221         obj = out.pointer;
1222         if (!obj)
1223                 return -ENXIO;
1224
1225         if (obj->type != ACPI_TYPE_BUFFER) {
1226                 retval = -ENXIO;
1227                 goto out_free_pointer;
1228         }
1229
1230         gblock = (const struct guid_block *)obj->buffer.pointer;
1231         total = obj->buffer.length / sizeof(struct guid_block);
1232
1233         for (i = 0; i < total; i++) {
1234                 if (debug_dump_wdg)
1235                         wmi_dump_wdg(&gblock[i]);
1236
1237                 if (guid_already_parsed_for_legacy(device, &gblock[i].guid))
1238                         continue;
1239
1240                 wblock = kzalloc(sizeof(*wblock), GFP_KERNEL);
1241                 if (!wblock) {
1242                         retval = -ENOMEM;
1243                         break;
1244                 }
1245
1246                 wblock->acpi_device = device;
1247                 wblock->gblock = gblock[i];
1248
1249                 retval = wmi_create_device(wmi_bus_dev, wblock, device);
1250                 if (retval) {
1251                         kfree(wblock);
1252                         continue;
1253                 }
1254
1255                 list_add_tail(&wblock->list, &wmi_block_list);
1256
1257                 if (debug_event) {
1258                         wblock->handler = wmi_notify_debug;
1259                         wmi_method_enable(wblock, true);
1260                 }
1261         }
1262
1263         /*
1264          * Now that all of the devices are created, add them to the
1265          * device tree and probe subdrivers.
1266          */
1267         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1268                 if (wblock->acpi_device != device)
1269                         continue;
1270
1271                 retval = device_add(&wblock->dev.dev);
1272                 if (retval) {
1273                         dev_err(wmi_bus_dev, "failed to register %pUL\n",
1274                                 &wblock->gblock.guid);
1275                         if (debug_event)
1276                                 wmi_method_enable(wblock, false);
1277                         list_del(&wblock->list);
1278                         put_device(&wblock->dev.dev);
1279                 }
1280         }
1281
1282 out_free_pointer:
1283         kfree(out.pointer);
1284         return retval;
1285 }
1286
1287 /*
1288  * WMI can have EmbeddedControl access regions. In which case, we just want to
1289  * hand these off to the EC driver.
1290  */
1291 static acpi_status
1292 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1293                           u32 bits, u64 *value,
1294                           void *handler_context, void *region_context)
1295 {
1296         int result = 0, i = 0;
1297         u8 temp = 0;
1298
1299         if ((address > 0xFF) || !value)
1300                 return AE_BAD_PARAMETER;
1301
1302         if (function != ACPI_READ && function != ACPI_WRITE)
1303                 return AE_BAD_PARAMETER;
1304
1305         if (bits != 8)
1306                 return AE_BAD_PARAMETER;
1307
1308         if (function == ACPI_READ) {
1309                 result = ec_read(address, &temp);
1310                 (*value) |= ((u64)temp) << i;
1311         } else {
1312                 temp = 0xff & ((*value) >> i);
1313                 result = ec_write(address, temp);
1314         }
1315
1316         switch (result) {
1317         case -EINVAL:
1318                 return AE_BAD_PARAMETER;
1319         case -ENODEV:
1320                 return AE_NOT_FOUND;
1321         case -ETIME:
1322                 return AE_TIME;
1323         default:
1324                 return AE_OK;
1325         }
1326 }
1327
1328 static void acpi_wmi_notify_handler(acpi_handle handle, u32 event,
1329                                     void *context)
1330 {
1331         struct wmi_block *wblock = NULL, *iter;
1332
1333         list_for_each_entry(iter, &wmi_block_list, list) {
1334                 struct guid_block *block = &iter->gblock;
1335
1336                 if (iter->acpi_device->handle == handle &&
1337                     (block->flags & ACPI_WMI_EVENT) &&
1338                     (block->notify_id == event)) {
1339                         wblock = iter;
1340                         break;
1341                 }
1342         }
1343
1344         if (!wblock)
1345                 return;
1346
1347         /* If a driver is bound, then notify the driver. */
1348         if (test_bit(WMI_PROBED, &wblock->flags) && wblock->dev.dev.driver) {
1349                 struct wmi_driver *driver = drv_to_wdrv(wblock->dev.dev.driver);
1350                 struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL };
1351                 acpi_status status;
1352
1353                 if (!driver->no_notify_data) {
1354                         status = get_event_data(wblock, &evdata);
1355                         if (ACPI_FAILURE(status)) {
1356                                 dev_warn(&wblock->dev.dev, "failed to get event data\n");
1357                                 return;
1358                         }
1359                 }
1360
1361                 if (driver->notify)
1362                         driver->notify(&wblock->dev, evdata.pointer);
1363
1364                 kfree(evdata.pointer);
1365         } else if (wblock->handler) {
1366                 /* Legacy handler */
1367                 wblock->handler(event, wblock->handler_data);
1368         }
1369
1370         if (debug_event)
1371                 pr_info("DEBUG: GUID %pUL event 0x%02X\n", &wblock->gblock.guid, event);
1372
1373         acpi_bus_generate_netlink_event(
1374                 wblock->acpi_device->pnp.device_class,
1375                 dev_name(&wblock->dev.dev),
1376                 event, 0);
1377 }
1378
1379 static int acpi_wmi_remove(struct platform_device *device)
1380 {
1381         struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev);
1382
1383         acpi_remove_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY,
1384                                    acpi_wmi_notify_handler);
1385         acpi_remove_address_space_handler(acpi_device->handle,
1386                                 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
1387         wmi_free_devices(acpi_device);
1388         device_unregister(dev_get_drvdata(&device->dev));
1389
1390         return 0;
1391 }
1392
1393 static int acpi_wmi_probe(struct platform_device *device)
1394 {
1395         struct acpi_device *acpi_device;
1396         struct device *wmi_bus_dev;
1397         acpi_status status;
1398         int error;
1399
1400         acpi_device = ACPI_COMPANION(&device->dev);
1401         if (!acpi_device) {
1402                 dev_err(&device->dev, "ACPI companion is missing\n");
1403                 return -ENODEV;
1404         }
1405
1406         status = acpi_install_address_space_handler(acpi_device->handle,
1407                                                     ACPI_ADR_SPACE_EC,
1408                                                     &acpi_wmi_ec_space_handler,
1409                                                     NULL, NULL);
1410         if (ACPI_FAILURE(status)) {
1411                 dev_err(&device->dev, "Error installing EC region handler\n");
1412                 return -ENODEV;
1413         }
1414
1415         status = acpi_install_notify_handler(acpi_device->handle,
1416                                              ACPI_ALL_NOTIFY,
1417                                              acpi_wmi_notify_handler,
1418                                              NULL);
1419         if (ACPI_FAILURE(status)) {
1420                 dev_err(&device->dev, "Error installing notify handler\n");
1421                 error = -ENODEV;
1422                 goto err_remove_ec_handler;
1423         }
1424
1425         wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0),
1426                                     NULL, "wmi_bus-%s", dev_name(&device->dev));
1427         if (IS_ERR(wmi_bus_dev)) {
1428                 error = PTR_ERR(wmi_bus_dev);
1429                 goto err_remove_notify_handler;
1430         }
1431         dev_set_drvdata(&device->dev, wmi_bus_dev);
1432
1433         error = parse_wdg(wmi_bus_dev, acpi_device);
1434         if (error) {
1435                 pr_err("Failed to parse WDG method\n");
1436                 goto err_remove_busdev;
1437         }
1438
1439         return 0;
1440
1441 err_remove_busdev:
1442         device_unregister(wmi_bus_dev);
1443
1444 err_remove_notify_handler:
1445         acpi_remove_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY,
1446                                    acpi_wmi_notify_handler);
1447
1448 err_remove_ec_handler:
1449         acpi_remove_address_space_handler(acpi_device->handle,
1450                                           ACPI_ADR_SPACE_EC,
1451                                           &acpi_wmi_ec_space_handler);
1452
1453         return error;
1454 }
1455
1456 int __must_check __wmi_driver_register(struct wmi_driver *driver,
1457                                        struct module *owner)
1458 {
1459         driver->driver.owner = owner;
1460         driver->driver.bus = &wmi_bus_type;
1461
1462         return driver_register(&driver->driver);
1463 }
1464 EXPORT_SYMBOL(__wmi_driver_register);
1465
1466 void wmi_driver_unregister(struct wmi_driver *driver)
1467 {
1468         driver_unregister(&driver->driver);
1469 }
1470 EXPORT_SYMBOL(wmi_driver_unregister);
1471
1472 static struct platform_driver acpi_wmi_driver = {
1473         .driver = {
1474                 .name = "acpi-wmi",
1475                 .acpi_match_table = wmi_device_ids,
1476         },
1477         .probe = acpi_wmi_probe,
1478         .remove = acpi_wmi_remove,
1479 };
1480
1481 static int __init acpi_wmi_init(void)
1482 {
1483         int error;
1484
1485         if (acpi_disabled)
1486                 return -ENODEV;
1487
1488         error = class_register(&wmi_bus_class);
1489         if (error)
1490                 return error;
1491
1492         error = bus_register(&wmi_bus_type);
1493         if (error)
1494                 goto err_unreg_class;
1495
1496         error = platform_driver_register(&acpi_wmi_driver);
1497         if (error) {
1498                 pr_err("Error loading mapper\n");
1499                 goto err_unreg_bus;
1500         }
1501
1502         return 0;
1503
1504 err_unreg_bus:
1505         bus_unregister(&wmi_bus_type);
1506
1507 err_unreg_class:
1508         class_unregister(&wmi_bus_class);
1509
1510         return error;
1511 }
1512
1513 static void __exit acpi_wmi_exit(void)
1514 {
1515         platform_driver_unregister(&acpi_wmi_driver);
1516         bus_unregister(&wmi_bus_type);
1517         class_unregister(&wmi_bus_class);
1518 }
1519
1520 subsys_initcall_sync(acpi_wmi_init);
1521 module_exit(acpi_wmi_exit);