drivers/platform/x86/wmi.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  ACPI-WMI mapping driver
   4  *
   5  *  Copyright (C) 2007-2008 Carlos Corbacho <carlos@strangeworlds.co.uk>
   6  *
   7  *  GUID parsing code from ldm.c is:
   8  *   Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
   9  *   Copyright (c) 2001-2007 Anton Altaparmakov
  10  *   Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
  11  *
  12  *  WMI bus infrastructure by Andrew Lutomirski and Darren Hart:
  13  *    Copyright (C) 2015 Andrew Lutomirski
  14  *    Copyright (C) 2017 VMware, Inc. All Rights Reserved.
  15  */
  16
  17 #define pr_fmt(fmt)     KBUILD_MODNAME ": " fmt
  18
  19 #include <linux/acpi.h>
  20 #include <linux/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         NULL
 109 };
 110
 111 /*
 112  * GUID parsing functions
 113  */
 114
 115 static acpi_status find_guid(const char *guid_string, struct wmi_block **out)
 116 {
 117         guid_t guid_input;
 118         struct wmi_block *wblock;
 119
 120         if (!guid_string)
 121                 return AE_BAD_PARAMETER;
 122
 123         if (guid_parse(guid_string, &guid_input))
 124                 return AE_BAD_PARAMETER;
 125
 126         list_for_each_entry(wblock, &wmi_block_list, list) {
 127                 if (guid_equal(&wblock->gblock.guid, &guid_input)) {
 128                         if (out)
 129                                 *out = wblock;
 130
 131                         return AE_OK;
 132                 }
 133         }
 134
 135         return AE_NOT_FOUND;
 136 }
 137
 138 static const void *find_guid_context(struct wmi_block *wblock,
 139                                      struct wmi_driver *wdriver)
 140 {
 141         const struct wmi_device_id *id;
 142
 143         id = wdriver->id_table;
 144         if (!id)
 145                 return NULL;
 146
 147         while (*id->guid_string) {
 148                 guid_t guid_input;
 149
 150                 if (guid_parse(id->guid_string, &guid_input))
 151                         continue;
 152                 if (guid_equal(&wblock->gblock.guid, &guid_input))
 153                         return id->context;
 154                 id++;
 155         }
 156         return NULL;
 157 }
 158
 159 static int get_subobj_info(acpi_handle handle, const char *pathname,
 160                            struct acpi_device_info **info)
 161 {
 162         struct acpi_device_info *dummy_info, **info_ptr;
 163         acpi_handle subobj_handle;
 164         acpi_status status;
 165
 166         status = acpi_get_handle(handle, (char *)pathname, &subobj_handle);
 167         if (status == AE_NOT_FOUND)
 168                 return -ENOENT;
 169         else if (ACPI_FAILURE(status))
 170                 return -EIO;
 171
 172         info_ptr = info ? info : &dummy_info;
 173         status = acpi_get_object_info(subobj_handle, info_ptr);
 174         if (ACPI_FAILURE(status))
 175                 return -EIO;
 176
 177         if (!info)
 178                 kfree(dummy_info);
 179
 180         return 0;
 181 }
 182
 183 static acpi_status wmi_method_enable(struct wmi_block *wblock, bool enable)
 184 {
 185         struct guid_block *block;
 186         char method[5];
 187         acpi_status status;
 188         acpi_handle handle;
 189
 190         block = &wblock->gblock;
 191         handle = wblock->acpi_device->handle;
 192
 193         snprintf(method, 5, "WE%02X", block->notify_id);
 194         status = acpi_execute_simple_method(handle, method, enable);
 195         if (status == AE_NOT_FOUND)
 196                 return AE_OK;
 197
 198         return status;
 199 }
 200
 201 #define WMI_ACPI_METHOD_NAME_SIZE 5
 202
 203 static inline void get_acpi_method_name(const struct wmi_block *wblock,
 204                                         const char method,
 205                                         char buffer[static WMI_ACPI_METHOD_NAME_SIZE])
 206 {
 207         static_assert(ARRAY_SIZE(wblock->gblock.object_id) == 2);
 208         static_assert(WMI_ACPI_METHOD_NAME_SIZE >= 5);
 209
 210         buffer[0] = 'W';
 211         buffer[1] = method;
 212         buffer[2] = wblock->gblock.object_id[0];
 213         buffer[3] = wblock->gblock.object_id[1];
 214         buffer[4] = '\0';
 215 }
 216
 217 static inline acpi_object_type get_param_acpi_type(const struct wmi_block *wblock)
 218 {
 219         if (wblock->gblock.flags & ACPI_WMI_STRING)
 220                 return ACPI_TYPE_STRING;
 221         else
 222                 return ACPI_TYPE_BUFFER;
 223 }
 224
 225 static acpi_status get_event_data(const struct wmi_block *wblock, struct acpi_buffer *out)
 226 {
 227         union acpi_object param = {
 228                 .integer = {
 229                         .type = ACPI_TYPE_INTEGER,
 230                         .value = wblock->gblock.notify_id,
 231                 }
 232         };
 233         struct acpi_object_list input = {
 234                 .count = 1,
 235                 .pointer = &param,
 236         };
 237
 238         return acpi_evaluate_object(wblock->acpi_device->handle, "_WED", &input, out);
 239 }
 240
 241 /*
 242  * Exported WMI functions
 243  */
 244
 245 /**
 246  * set_required_buffer_size - Sets the buffer size needed for performing IOCTL
 247  * @wdev: A wmi bus device from a driver
 248  * @length: Required buffer size
 249  *
 250  * Allocates memory needed for buffer, stores the buffer size in that memory
 251  */
 252 int set_required_buffer_size(struct wmi_device *wdev, u64 length)
 253 {
 254         struct wmi_block *wblock;
 255
 256         wblock = container_of(wdev, struct wmi_block, dev);
 257         wblock->req_buf_size = length;
 258
 259         return 0;
 260 }
 261 EXPORT_SYMBOL_GPL(set_required_buffer_size);
 262
 263 /**
 264  * wmi_evaluate_method - Evaluate a WMI method
 265  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 266  * @instance: Instance index
 267  * @method_id: Method ID to call
 268  * @in: Buffer containing input for the method call
 269  * @out: Empty buffer to return the method results
 270  *
 271  * Call an ACPI-WMI method
 272  */
 273 acpi_status wmi_evaluate_method(const char *guid_string, u8 instance, u32 method_id,
 274                                 const struct acpi_buffer *in, struct acpi_buffer *out)
 275 {
 276         struct wmi_block *wblock = NULL;
 277         acpi_status status;
 278
 279         status = find_guid(guid_string, &wblock);
 280         if (ACPI_FAILURE(status))
 281                 return status;
 282
 283         return wmidev_evaluate_method(&wblock->dev, instance, method_id,
 284                                       in, out);
 285 }
 286 EXPORT_SYMBOL_GPL(wmi_evaluate_method);
 287
 288 /**
 289  * wmidev_evaluate_method - Evaluate a WMI method
 290  * @wdev: A wmi bus device from a driver
 291  * @instance: Instance index
 292  * @method_id: Method ID to call
 293  * @in: Buffer containing input for the method call
 294  * @out: Empty buffer to return the method results
 295  *
 296  * Call an ACPI-WMI method
 297  */
 298 acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance, u32 method_id,
 299                                    const struct acpi_buffer *in, struct acpi_buffer *out)
 300 {
 301         struct guid_block *block;
 302         struct wmi_block *wblock;
 303         acpi_handle handle;
 304         struct acpi_object_list input;
 305         union acpi_object params[3];
 306         char method[WMI_ACPI_METHOD_NAME_SIZE];
 307
 308         wblock = container_of(wdev, struct wmi_block, dev);
 309         block = &wblock->gblock;
 310         handle = wblock->acpi_device->handle;
 311
 312         if (!(block->flags & ACPI_WMI_METHOD))
 313                 return AE_BAD_DATA;
 314
 315         if (block->instance_count <= instance)
 316                 return AE_BAD_PARAMETER;
 317
 318         input.count = 2;
 319         input.pointer = params;
 320         params[0].type = ACPI_TYPE_INTEGER;
 321         params[0].integer.value = instance;
 322         params[1].type = ACPI_TYPE_INTEGER;
 323         params[1].integer.value = method_id;
 324
 325         if (in) {
 326                 input.count = 3;
 327
 328                 params[2].type = get_param_acpi_type(wblock);
 329                 params[2].buffer.length = in->length;
 330                 params[2].buffer.pointer = in->pointer;
 331         }
 332
 333         get_acpi_method_name(wblock, 'M', method);
 334
 335         return acpi_evaluate_object(handle, method, &input, out);
 336 }
 337 EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
 338
 339 static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
 340                                  struct acpi_buffer *out)
 341 {
 342         struct guid_block *block;
 343         acpi_handle handle;
 344         acpi_status status, wc_status = AE_ERROR;
 345         struct acpi_object_list input;
 346         union acpi_object wq_params[1];
 347         char wc_method[WMI_ACPI_METHOD_NAME_SIZE];
 348         char method[WMI_ACPI_METHOD_NAME_SIZE];
 349
 350         if (!out)
 351                 return AE_BAD_PARAMETER;
 352
 353         block = &wblock->gblock;
 354         handle = wblock->acpi_device->handle;
 355
 356         if (block->instance_count <= instance)
 357                 return AE_BAD_PARAMETER;
 358
 359         /* Check GUID is a data block */
 360         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 361                 return AE_ERROR;
 362
 363         input.count = 1;
 364         input.pointer = wq_params;
 365         wq_params[0].type = ACPI_TYPE_INTEGER;
 366         wq_params[0].integer.value = instance;
 367
 368         if (instance == 0 && test_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags))
 369                 input.count = 0;
 370
 371         /*
 372          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
 373          * enable collection.
 374          */
 375         if (block->flags & ACPI_WMI_EXPENSIVE) {
 376                 get_acpi_method_name(wblock, 'C', wc_method);
 377
 378                 /*
 379                  * Some GUIDs break the specification by declaring themselves
 380                  * expensive, but have no corresponding WCxx method. So we
 381                  * should not fail if this happens.
 382                  */
 383                 wc_status = acpi_execute_simple_method(handle, wc_method, 1);
 384         }
 385
 386         get_acpi_method_name(wblock, 'Q', method);
 387         status = acpi_evaluate_object(handle, method, &input, out);
 388
 389         /*
 390          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
 391          * the WQxx method failed - we should disable collection anyway.
 392          */
 393         if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
 394                 /*
 395                  * Ignore whether this WCxx call succeeds or not since
 396                  * the previously executed WQxx method call might have
 397                  * succeeded, and returning the failing status code
 398                  * of this call would throw away the result of the WQxx
 399                  * call, potentially leaking memory.
 400                  */
 401                 acpi_execute_simple_method(handle, wc_method, 0);
 402         }
 403
 404         return status;
 405 }
 406
 407 /**
 408  * wmi_query_block - Return contents of a WMI block (deprecated)
 409  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 410  * @instance: Instance index
 411  * @out: Empty buffer to return the contents of the data block to
 412  *
 413  * Return the contents of an ACPI-WMI data block to a buffer
 414  */
 415 acpi_status wmi_query_block(const char *guid_string, u8 instance,
 416                             struct acpi_buffer *out)
 417 {
 418         struct wmi_block *wblock;
 419         acpi_status status;
 420
 421         status = find_guid(guid_string, &wblock);
 422         if (ACPI_FAILURE(status))
 423                 return status;
 424
 425         return __query_block(wblock, instance, out);
 426 }
 427 EXPORT_SYMBOL_GPL(wmi_query_block);
 428
 429 union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
 430 {
 431         struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
 432         struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
 433
 434         if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
 435                 return NULL;
 436
 437         return out.pointer;
 438 }
 439 EXPORT_SYMBOL_GPL(wmidev_block_query);
 440
 441 /**
 442  * wmi_set_block - Write to a WMI block
 443  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 444  * @instance: Instance index
 445  * @in: Buffer containing new values for the data block
 446  *
 447  * Write the contents of the input buffer to an ACPI-WMI data block
 448  */
 449 acpi_status wmi_set_block(const char *guid_string, u8 instance,
 450                           const struct acpi_buffer *in)
 451 {
 452         struct wmi_block *wblock = NULL;
 453         struct guid_block *block;
 454         acpi_handle handle;
 455         struct acpi_object_list input;
 456         union acpi_object params[2];
 457         char method[WMI_ACPI_METHOD_NAME_SIZE];
 458         acpi_status status;
 459
 460         if (!in)
 461                 return AE_BAD_DATA;
 462
 463         status = find_guid(guid_string, &wblock);
 464         if (ACPI_FAILURE(status))
 465                 return status;
 466
 467         block = &wblock->gblock;
 468         handle = wblock->acpi_device->handle;
 469
 470         if (block->instance_count <= instance)
 471                 return AE_BAD_PARAMETER;
 472
 473         /* Check GUID is a data block */
 474         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 475                 return AE_ERROR;
 476
 477         input.count = 2;
 478         input.pointer = params;
 479         params[0].type = ACPI_TYPE_INTEGER;
 480         params[0].integer.value = instance;
 481         params[1].type = get_param_acpi_type(wblock);
 482         params[1].buffer.length = in->length;
 483         params[1].buffer.pointer = in->pointer;
 484
 485         get_acpi_method_name(wblock, 'S', method);
 486
 487         return acpi_evaluate_object(handle, method, &input, NULL);
 488 }
 489 EXPORT_SYMBOL_GPL(wmi_set_block);
 490
 491 static void wmi_dump_wdg(const struct guid_block *g)
 492 {
 493         pr_info("%pUL:\n", &g->guid);
 494         if (g->flags & ACPI_WMI_EVENT)
 495                 pr_info("\tnotify_id: 0x%02X\n", g->notify_id);
 496         else
 497                 pr_info("\tobject_id: %2pE\n", g->object_id);
 498         pr_info("\tinstance_count: %d\n", g->instance_count);
 499         pr_info("\tflags: %#x", g->flags);
 500         if (g->flags) {
 501                 if (g->flags & ACPI_WMI_EXPENSIVE)
 502                         pr_cont(" ACPI_WMI_EXPENSIVE");
 503                 if (g->flags & ACPI_WMI_METHOD)
 504                         pr_cont(" ACPI_WMI_METHOD");
 505                 if (g->flags & ACPI_WMI_STRING)
 506                         pr_cont(" ACPI_WMI_STRING");
 507                 if (g->flags & ACPI_WMI_EVENT)
 508                         pr_cont(" ACPI_WMI_EVENT");
 509         }
 510         pr_cont("\n");
 511
 512 }
 513
 514 static void wmi_notify_debug(u32 value, void *context)
 515 {
 516         struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
 517         union acpi_object *obj;
 518         acpi_status status;
 519
 520         status = wmi_get_event_data(value, &response);
 521         if (status != AE_OK) {
 522                 pr_info("bad event status 0x%x\n", status);
 523                 return;
 524         }
 525
 526         obj = response.pointer;
 527         if (!obj)
 528                 return;
 529
 530         pr_info("DEBUG: event 0x%02X ", value);
 531         switch (obj->type) {
 532         case ACPI_TYPE_BUFFER:
 533                 pr_cont("BUFFER_TYPE - length %u\n", obj->buffer.length);
 534                 break;
 535         case ACPI_TYPE_STRING:
 536                 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
 537                 break;
 538         case ACPI_TYPE_INTEGER:
 539                 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
 540                 break;
 541         case ACPI_TYPE_PACKAGE:
 542                 pr_cont("PACKAGE_TYPE - %u elements\n", obj->package.count);
 543                 break;
 544         default:
 545                 pr_cont("object type 0x%X\n", obj->type);
 546         }
 547         kfree(obj);
 548 }
 549
 550 /**
 551  * wmi_install_notify_handler - Register handler for WMI events
 552  * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 553  * @handler: Function to handle notifications
 554  * @data: Data to be returned to handler when event is fired
 555  *
 556  * Register a handler for events sent to the ACPI-WMI mapper device.
 557  */
 558 acpi_status wmi_install_notify_handler(const char *guid,
 559                                        wmi_notify_handler handler,
 560                                        void *data)
 561 {
 562         struct wmi_block *block;
 563         acpi_status status = AE_NOT_EXIST;
 564         guid_t guid_input;
 565
 566         if (!guid || !handler)
 567                 return AE_BAD_PARAMETER;
 568
 569         if (guid_parse(guid, &guid_input))
 570                 return AE_BAD_PARAMETER;
 571
 572         list_for_each_entry(block, &wmi_block_list, list) {
 573                 acpi_status wmi_status;
 574
 575                 if (guid_equal(&block->gblock.guid, &guid_input)) {
 576                         if (block->handler &&
 577                             block->handler != wmi_notify_debug)
 578                                 return AE_ALREADY_ACQUIRED;
 579
 580                         block->handler = handler;
 581                         block->handler_data = data;
 582
 583                         wmi_status = wmi_method_enable(block, true);
 584                         if ((wmi_status != AE_OK) ||
 585                             ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
 586                                 status = wmi_status;
 587                 }
 588         }
 589
 590         return status;
 591 }
 592 EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
 593
 594 /**
 595  * wmi_remove_notify_handler - Unregister handler for WMI events
 596  * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 597  *
 598  * Unregister handler for events sent to the ACPI-WMI mapper device.
 599  */
 600 acpi_status wmi_remove_notify_handler(const char *guid)
 601 {
 602         struct wmi_block *block;
 603         acpi_status status = AE_NOT_EXIST;
 604         guid_t guid_input;
 605
 606         if (!guid)
 607                 return AE_BAD_PARAMETER;
 608
 609         if (guid_parse(guid, &guid_input))
 610                 return AE_BAD_PARAMETER;
 611
 612         list_for_each_entry(block, &wmi_block_list, list) {
 613                 acpi_status wmi_status;
 614
 615                 if (guid_equal(&block->gblock.guid, &guid_input)) {
 616                         if (!block->handler ||
 617                             block->handler == wmi_notify_debug)
 618                                 return AE_NULL_ENTRY;
 619
 620                         if (debug_event) {
 621                                 block->handler = wmi_notify_debug;
 622                                 status = AE_OK;
 623                         } else {
 624                                 wmi_status = wmi_method_enable(block, false);
 625                                 block->handler = NULL;
 626                                 block->handler_data = NULL;
 627                                 if ((wmi_status != AE_OK) ||
 628                                     ((wmi_status == AE_OK) &&
 629                                      (status == AE_NOT_EXIST)))
 630                                         status = wmi_status;
 631                         }
 632                 }
 633         }
 634
 635         return status;
 636 }
 637 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
 638
 639 /**
 640  * wmi_get_event_data - Get WMI data associated with an event
 641  *
 642  * @event: Event to find
 643  * @out: Buffer to hold event data. out->pointer should be freed with kfree()
 644  *
 645  * Returns extra data associated with an event in WMI.
 646  */
 647 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
 648 {
 649         struct wmi_block *wblock;
 650
 651         list_for_each_entry(wblock, &wmi_block_list, list) {
 652                 struct guid_block *gblock = &wblock->gblock;
 653
 654                 if ((gblock->flags & ACPI_WMI_EVENT) && gblock->notify_id == event)
 655                         return get_event_data(wblock, out);
 656         }
 657
 658         return AE_NOT_FOUND;
 659 }
 660 EXPORT_SYMBOL_GPL(wmi_get_event_data);
 661
 662 /**
 663  * wmi_has_guid - Check if a GUID is available
 664  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 665  *
 666  * Check if a given GUID is defined by _WDG
 667  */
 668 bool wmi_has_guid(const char *guid_string)
 669 {
 670         return ACPI_SUCCESS(find_guid(guid_string, NULL));
 671 }
 672 EXPORT_SYMBOL_GPL(wmi_has_guid);
 673
 674 /**
 675  * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID
 676  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 677  *
 678  * Find the _UID of ACPI device associated with this WMI GUID.
 679  *
 680  * Return: The ACPI _UID field value or NULL if the WMI GUID was not found
 681  */
 682 char *wmi_get_acpi_device_uid(const char *guid_string)
 683 {
 684         struct wmi_block *wblock = NULL;
 685         acpi_status status;
 686
 687         status = find_guid(guid_string, &wblock);
 688         if (ACPI_FAILURE(status))
 689                 return NULL;
 690
 691         return acpi_device_uid(wblock->acpi_device);
 692 }
 693 EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
 694
 695 static struct wmi_block *dev_to_wblock(struct device *dev)
 696 {
 697         return container_of(dev, struct wmi_block, dev.dev);
 698 }
 699
 700 static struct wmi_device *dev_to_wdev(struct device *dev)
 701 {
 702         return container_of(dev, struct wmi_device, dev);
 703 }
 704
 705 static inline struct wmi_driver *drv_to_wdrv(struct device_driver *drv)
 706 {
 707         return container_of(drv, struct wmi_driver, driver);
 708 }
 709
 710 /*
 711  * sysfs interface
 712  */
 713 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 714                              char *buf)
 715 {
 716         struct wmi_block *wblock = dev_to_wblock(dev);
 717
 718         return sysfs_emit(buf, "wmi:%pUL\n", &wblock->gblock.guid);
 719 }
 720 static DEVICE_ATTR_RO(modalias);
 721
 722 static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
 723                          char *buf)
 724 {
 725         struct wmi_block *wblock = dev_to_wblock(dev);
 726
 727         return sysfs_emit(buf, "%pUL\n", &wblock->gblock.guid);
 728 }
 729 static DEVICE_ATTR_RO(guid);
 730
 731 static ssize_t instance_count_show(struct device *dev,
 732                                    struct device_attribute *attr, char *buf)
 733 {
 734         struct wmi_block *wblock = dev_to_wblock(dev);
 735
 736         return sysfs_emit(buf, "%d\n", (int)wblock->gblock.instance_count);
 737 }
 738 static DEVICE_ATTR_RO(instance_count);
 739
 740 static ssize_t expensive_show(struct device *dev,
 741                               struct device_attribute *attr, char *buf)
 742 {
 743         struct wmi_block *wblock = dev_to_wblock(dev);
 744
 745         return sysfs_emit(buf, "%d\n",
 746                           (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
 747 }
 748 static DEVICE_ATTR_RO(expensive);
 749
 750 static struct attribute *wmi_attrs[] = {
 751         &dev_attr_modalias.attr,
 752         &dev_attr_guid.attr,
 753         &dev_attr_instance_count.attr,
 754         &dev_attr_expensive.attr,
 755         NULL
 756 };
 757 ATTRIBUTE_GROUPS(wmi);
 758
 759 static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
 760                               char *buf)
 761 {
 762         struct wmi_block *wblock = dev_to_wblock(dev);
 763
 764         return sysfs_emit(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
 765 }
 766 static DEVICE_ATTR_RO(notify_id);
 767
 768 static struct attribute *wmi_event_attrs[] = {
 769         &dev_attr_notify_id.attr,
 770         NULL
 771 };
 772 ATTRIBUTE_GROUPS(wmi_event);
 773
 774 static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
 775                               char *buf)
 776 {
 777         struct wmi_block *wblock = dev_to_wblock(dev);
 778
 779         return sysfs_emit(buf, "%c%c\n", wblock->gblock.object_id[0],
 780                           wblock->gblock.object_id[1]);
 781 }
 782 static DEVICE_ATTR_RO(object_id);
 783
 784 static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
 785                             char *buf)
 786 {
 787         struct wmi_device *wdev = dev_to_wdev(dev);
 788
 789         return sysfs_emit(buf, "%d\n", (int)wdev->setable);
 790 }
 791 static DEVICE_ATTR_RO(setable);
 792
 793 static struct attribute *wmi_data_attrs[] = {
 794         &dev_attr_object_id.attr,
 795         &dev_attr_setable.attr,
 796         NULL
 797 };
 798 ATTRIBUTE_GROUPS(wmi_data);
 799
 800 static struct attribute *wmi_method_attrs[] = {
 801         &dev_attr_object_id.attr,
 802         NULL
 803 };
 804 ATTRIBUTE_GROUPS(wmi_method);
 805
 806 static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 807 {
 808         struct wmi_block *wblock = dev_to_wblock(dev);
 809
 810         if (add_uevent_var(env, "MODALIAS=wmi:%pUL", &wblock->gblock.guid))
 811                 return -ENOMEM;
 812
 813         if (add_uevent_var(env, "WMI_GUID=%pUL", &wblock->gblock.guid))
 814                 return -ENOMEM;
 815
 816         return 0;
 817 }
 818
 819 static void wmi_dev_release(struct device *dev)
 820 {
 821         struct wmi_block *wblock = dev_to_wblock(dev);
 822
 823         kfree(wblock);
 824 }
 825
 826 static int wmi_dev_match(struct device *dev, struct device_driver *driver)
 827 {
 828         struct wmi_driver *wmi_driver = drv_to_wdrv(driver);
 829         struct wmi_block *wblock = dev_to_wblock(dev);
 830         const struct wmi_device_id *id = wmi_driver->id_table;
 831
 832         if (id == NULL)
 833                 return 0;
 834
 835         while (*id->guid_string) {
 836                 guid_t driver_guid;
 837
 838                 if (WARN_ON(guid_parse(id->guid_string, &driver_guid)))
 839                         continue;
 840                 if (guid_equal(&driver_guid, &wblock->gblock.guid))
 841                         return 1;
 842
 843                 id++;
 844         }
 845
 846         return 0;
 847 }
 848 static int wmi_char_open(struct inode *inode, struct file *filp)
 849 {
 850         const char *driver_name = filp->f_path.dentry->d_iname;
 851         struct wmi_block *wblock;
 852         struct wmi_block *next;
 853
 854         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
 855                 if (!wblock->dev.dev.driver)
 856                         continue;
 857                 if (strcmp(driver_name, wblock->dev.dev.driver->name) == 0) {
 858                         filp->private_data = wblock;
 859                         break;
 860                 }
 861         }
 862
 863         if (!filp->private_data)
 864                 return -ENODEV;
 865
 866         return nonseekable_open(inode, filp);
 867 }
 868
 869 static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
 870                              size_t length, loff_t *offset)
 871 {
 872         struct wmi_block *wblock = filp->private_data;
 873
 874         return simple_read_from_buffer(buffer, length, offset,
 875                                        &wblock->req_buf_size,
 876                                        sizeof(wblock->req_buf_size));
 877 }
 878
 879 static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 880 {
 881         struct wmi_ioctl_buffer __user *input =
 882                 (struct wmi_ioctl_buffer __user *) arg;
 883         struct wmi_block *wblock = filp->private_data;
 884         struct wmi_ioctl_buffer *buf;
 885         struct wmi_driver *wdriver;
 886         int ret;
 887
 888         if (_IOC_TYPE(cmd) != WMI_IOC)
 889                 return -ENOTTY;
 890
 891         /* make sure we're not calling a higher instance than exists*/
 892         if (_IOC_NR(cmd) >= wblock->gblock.instance_count)
 893                 return -EINVAL;
 894
 895         mutex_lock(&wblock->char_mutex);
 896         buf = wblock->handler_data;
 897         if (get_user(buf->length, &input->length)) {
 898                 dev_dbg(&wblock->dev.dev, "Read length from user failed\n");
 899                 ret = -EFAULT;
 900                 goto out_ioctl;
 901         }
 902         /* if it's too small, abort */
 903         if (buf->length < wblock->req_buf_size) {
 904                 dev_err(&wblock->dev.dev,
 905                         "Buffer %lld too small, need at least %lld\n",
 906                         buf->length, wblock->req_buf_size);
 907                 ret = -EINVAL;
 908                 goto out_ioctl;
 909         }
 910         /* if it's too big, warn, driver will only use what is needed */
 911         if (buf->length > wblock->req_buf_size)
 912                 dev_warn(&wblock->dev.dev,
 913                         "Buffer %lld is bigger than required %lld\n",
 914                         buf->length, wblock->req_buf_size);
 915
 916         /* copy the structure from userspace */
 917         if (copy_from_user(buf, input, wblock->req_buf_size)) {
 918                 dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n",
 919                         wblock->req_buf_size);
 920                 ret = -EFAULT;
 921                 goto out_ioctl;
 922         }
 923
 924         /* let the driver do any filtering and do the call */
 925         wdriver = drv_to_wdrv(wblock->dev.dev.driver);
 926         if (!try_module_get(wdriver->driver.owner)) {
 927                 ret = -EBUSY;
 928                 goto out_ioctl;
 929         }
 930         ret = wdriver->filter_callback(&wblock->dev, cmd, buf);
 931         module_put(wdriver->driver.owner);
 932         if (ret)
 933                 goto out_ioctl;
 934
 935         /* return the result (only up to our internal buffer size) */
 936         if (copy_to_user(input, buf, wblock->req_buf_size)) {
 937                 dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n",
 938                         wblock->req_buf_size);
 939                 ret = -EFAULT;
 940         }
 941
 942 out_ioctl:
 943         mutex_unlock(&wblock->char_mutex);
 944         return ret;
 945 }
 946
 947 static const struct file_operations wmi_fops = {
 948         .owner          = THIS_MODULE,
 949         .read           = wmi_char_read,
 950         .open           = wmi_char_open,
 951         .unlocked_ioctl = wmi_ioctl,
 952         .compat_ioctl   = compat_ptr_ioctl,
 953 };
 954
 955 static int wmi_dev_probe(struct device *dev)
 956 {
 957         struct wmi_block *wblock = dev_to_wblock(dev);
 958         struct wmi_driver *wdriver = drv_to_wdrv(dev->driver);
 959         int ret = 0;
 960         char *buf;
 961
 962         if (ACPI_FAILURE(wmi_method_enable(wblock, true)))
 963                 dev_warn(dev, "failed to enable device -- probing anyway\n");
 964
 965         if (wdriver->probe) {
 966                 ret = wdriver->probe(dev_to_wdev(dev),
 967                                 find_guid_context(wblock, wdriver));
 968                 if (ret != 0)
 969                         goto probe_failure;
 970         }
 971
 972         /* driver wants a character device made */
 973         if (wdriver->filter_callback) {
 974                 /* check that required buffer size declared by driver or MOF */
 975                 if (!wblock->req_buf_size) {
 976                         dev_err(&wblock->dev.dev,
 977                                 "Required buffer size not set\n");
 978                         ret = -EINVAL;
 979                         goto probe_failure;
 980                 }
 981
 982                 wblock->handler_data = kmalloc(wblock->req_buf_size,
 983                                                GFP_KERNEL);
 984                 if (!wblock->handler_data) {
 985                         ret = -ENOMEM;
 986                         goto probe_failure;
 987                 }
 988
 989                 buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name);
 990                 if (!buf) {
 991                         ret = -ENOMEM;
 992                         goto probe_string_failure;
 993                 }
 994                 wblock->char_dev.minor = MISC_DYNAMIC_MINOR;
 995                 wblock->char_dev.name = buf;
 996                 wblock->char_dev.fops = &wmi_fops;
 997                 wblock->char_dev.mode = 0444;
 998                 ret = misc_register(&wblock->char_dev);
 999                 if (ret) {
1000                         dev_warn(dev, "failed to register char dev: %d\n", ret);
1001                         ret = -ENOMEM;
1002                         goto probe_misc_failure;
1003                 }
1004         }
1005
1006         set_bit(WMI_PROBED, &wblock->flags);
1007         return 0;
1008
1009 probe_misc_failure:
1010         kfree(buf);
1011 probe_string_failure:
1012         kfree(wblock->handler_data);
1013 probe_failure:
1014         if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
1015                 dev_warn(dev, "failed to disable device\n");
1016         return ret;
1017 }
1018
1019 static void wmi_dev_remove(struct device *dev)
1020 {
1021         struct wmi_block *wblock = dev_to_wblock(dev);
1022         struct wmi_driver *wdriver = drv_to_wdrv(dev->driver);
1023
1024         clear_bit(WMI_PROBED, &wblock->flags);
1025
1026         if (wdriver->filter_callback) {
1027                 misc_deregister(&wblock->char_dev);
1028                 kfree(wblock->char_dev.name);
1029                 kfree(wblock->handler_data);
1030         }
1031
1032         if (wdriver->remove)
1033                 wdriver->remove(dev_to_wdev(dev));
1034
1035         if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
1036                 dev_warn(dev, "failed to disable device\n");
1037 }
1038
1039 static struct class wmi_bus_class = {
1040         .name = "wmi_bus",
1041 };
1042
1043 static struct bus_type wmi_bus_type = {
1044         .name = "wmi",
1045         .dev_groups = wmi_groups,
1046         .match = wmi_dev_match,
1047         .uevent = wmi_dev_uevent,
1048         .probe = wmi_dev_probe,
1049         .remove = wmi_dev_remove,
1050 };
1051
1052 static const struct device_type wmi_type_event = {
1053         .name = "event",
1054         .groups = wmi_event_groups,
1055         .release = wmi_dev_release,
1056 };
1057
1058 static const struct device_type wmi_type_method = {
1059         .name = "method",
1060         .groups = wmi_method_groups,
1061         .release = wmi_dev_release,
1062 };
1063
1064 static const struct device_type wmi_type_data = {
1065         .name = "data",
1066         .groups = wmi_data_groups,
1067         .release = wmi_dev_release,
1068 };
1069
1070 /*
1071  * _WDG is a static list that is only parsed at startup,
1072  * so it's safe to count entries without extra protection.
1073  */
1074 static int guid_count(const guid_t *guid)
1075 {
1076         struct wmi_block *wblock;
1077         int count = 0;
1078
1079         list_for_each_entry(wblock, &wmi_block_list, list) {
1080                 if (guid_equal(&wblock->gblock.guid, guid))
1081                         count++;
1082         }
1083
1084         return count;
1085 }
1086
1087 static int wmi_create_device(struct device *wmi_bus_dev,
1088                              struct wmi_block *wblock,
1089                              struct acpi_device *device)
1090 {
1091         struct acpi_device_info *info;
1092         char method[WMI_ACPI_METHOD_NAME_SIZE];
1093         int result;
1094         uint count;
1095
1096         if (wblock->gblock.flags & ACPI_WMI_EVENT) {
1097                 wblock->dev.dev.type = &wmi_type_event;
1098                 goto out_init;
1099         }
1100
1101         if (wblock->gblock.flags & ACPI_WMI_METHOD) {
1102                 wblock->dev.dev.type = &wmi_type_method;
1103                 mutex_init(&wblock->char_mutex);
1104                 goto out_init;
1105         }
1106
1107         /*
1108          * Data Block Query Control Method (WQxx by convention) is
1109          * required per the WMI documentation. If it is not present,
1110          * we ignore this data block.
1111          */
1112         get_acpi_method_name(wblock, 'Q', method);
1113         result = get_subobj_info(device->handle, method, &info);
1114
1115         if (result) {
1116                 dev_warn(wmi_bus_dev,
1117                          "%s data block query control method not found\n",
1118                          method);
1119                 return result;
1120         }
1121
1122         wblock->dev.dev.type = &wmi_type_data;
1123
1124         /*
1125          * The Microsoft documentation specifically states:
1126          *
1127          *   Data blocks registered with only a single instance
1128          *   can ignore the parameter.
1129          *
1130          * ACPICA will get mad at us if we call the method with the wrong number
1131          * of arguments, so check what our method expects.  (On some Dell
1132          * laptops, WQxx may not be a method at all.)
1133          */
1134         if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1135                 set_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags);
1136
1137         kfree(info);
1138
1139         get_acpi_method_name(wblock, 'S', method);
1140         result = get_subobj_info(device->handle, method, NULL);
1141
1142         if (result == 0)
1143                 wblock->dev.setable = true;
1144
1145  out_init:
1146         wblock->dev.dev.bus = &wmi_bus_type;
1147         wblock->dev.dev.parent = wmi_bus_dev;
1148
1149         count = guid_count(&wblock->gblock.guid);
1150         if (count)
1151                 dev_set_name(&wblock->dev.dev, "%pUL-%d", &wblock->gblock.guid, count);
1152         else
1153                 dev_set_name(&wblock->dev.dev, "%pUL", &wblock->gblock.guid);
1154
1155         device_initialize(&wblock->dev.dev);
1156
1157         return 0;
1158 }
1159
1160 static void wmi_free_devices(struct acpi_device *device)
1161 {
1162         struct wmi_block *wblock, *next;
1163
1164         /* Delete devices for all the GUIDs */
1165         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1166                 if (wblock->acpi_device == device) {
1167                         list_del(&wblock->list);
1168                         device_unregister(&wblock->dev.dev);
1169                 }
1170         }
1171 }
1172
1173 static bool guid_already_parsed_for_legacy(struct acpi_device *device, const guid_t *guid)
1174 {
1175         struct wmi_block *wblock;
1176
1177         list_for_each_entry(wblock, &wmi_block_list, list) {
1178                 /* skip warning and register if we know the driver will use struct wmi_driver */
1179                 for (int i = 0; allow_duplicates[i] != NULL; i++) {
1180                         guid_t tmp;
1181
1182                         if (guid_parse(allow_duplicates[i], &tmp))
1183                                 continue;
1184                         if (guid_equal(&tmp, guid))
1185                                 return false;
1186                 }
1187                 if (guid_equal(&wblock->gblock.guid, guid)) {
1188                         /*
1189                          * Because we historically didn't track the relationship
1190                          * between GUIDs and ACPI nodes, we don't know whether
1191                          * we need to suppress GUIDs that are unique on a
1192                          * given node but duplicated across nodes.
1193                          */
1194                         dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
1195                                  guid, dev_name(&wblock->acpi_device->dev));
1196                         return true;
1197                 }
1198         }
1199
1200         return false;
1201 }
1202
1203 /*
1204  * Parse the _WDG method for the GUID data blocks
1205  */
1206 static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
1207 {
1208         struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1209         const struct guid_block *gblock;
1210         struct wmi_block *wblock, *next;
1211         union acpi_object *obj;
1212         acpi_status status;
1213         int retval = 0;
1214         u32 i, total;
1215
1216         status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1217         if (ACPI_FAILURE(status))
1218                 return -ENXIO;
1219
1220         obj = out.pointer;
1221         if (!obj)
1222                 return -ENXIO;
1223
1224         if (obj->type != ACPI_TYPE_BUFFER) {
1225                 retval = -ENXIO;
1226                 goto out_free_pointer;
1227         }
1228
1229         gblock = (const struct guid_block *)obj->buffer.pointer;
1230         total = obj->buffer.length / sizeof(struct guid_block);
1231
1232         for (i = 0; i < total; i++) {
1233                 if (debug_dump_wdg)
1234                         wmi_dump_wdg(&gblock[i]);
1235
1236                 if (guid_already_parsed_for_legacy(device, &gblock[i].guid))
1237                         continue;
1238
1239                 wblock = kzalloc(sizeof(*wblock), GFP_KERNEL);
1240                 if (!wblock) {
1241                         retval = -ENOMEM;
1242                         break;
1243                 }
1244
1245                 wblock->acpi_device = device;
1246                 wblock->gblock = gblock[i];
1247
1248                 retval = wmi_create_device(wmi_bus_dev, wblock, device);
1249                 if (retval) {
1250                         kfree(wblock);
1251                         continue;
1252                 }
1253
1254                 list_add_tail(&wblock->list, &wmi_block_list);
1255
1256                 if (debug_event) {
1257                         wblock->handler = wmi_notify_debug;
1258                         wmi_method_enable(wblock, true);
1259                 }
1260         }
1261
1262         /*
1263          * Now that all of the devices are created, add them to the
1264          * device tree and probe subdrivers.
1265          */
1266         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1267                 if (wblock->acpi_device != device)
1268                         continue;
1269
1270                 retval = device_add(&wblock->dev.dev);
1271                 if (retval) {
1272                         dev_err(wmi_bus_dev, "failed to register %pUL\n",
1273                                 &wblock->gblock.guid);
1274                         if (debug_event)
1275                                 wmi_method_enable(wblock, false);
1276                         list_del(&wblock->list);
1277                         put_device(&wblock->dev.dev);
1278                 }
1279         }
1280
1281 out_free_pointer:
1282         kfree(out.pointer);
1283         return retval;
1284 }
1285
1286 /*
1287  * WMI can have EmbeddedControl access regions. In which case, we just want to
1288  * hand these off to the EC driver.
1289  */
1290 static acpi_status
1291 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1292                           u32 bits, u64 *value,
1293                           void *handler_context, void *region_context)
1294 {
1295         int result = 0, i = 0;
1296         u8 temp = 0;
1297
1298         if ((address > 0xFF) || !value)
1299                 return AE_BAD_PARAMETER;
1300
1301         if (function != ACPI_READ && function != ACPI_WRITE)
1302                 return AE_BAD_PARAMETER;
1303
1304         if (bits != 8)
1305                 return AE_BAD_PARAMETER;
1306
1307         if (function == ACPI_READ) {
1308                 result = ec_read(address, &temp);
1309                 (*value) |= ((u64)temp) << i;
1310         } else {
1311                 temp = 0xff & ((*value) >> i);
1312                 result = ec_write(address, temp);
1313         }
1314
1315         switch (result) {
1316         case -EINVAL:
1317                 return AE_BAD_PARAMETER;
1318         case -ENODEV:
1319                 return AE_NOT_FOUND;
1320         case -ETIME:
1321                 return AE_TIME;
1322         default:
1323                 return AE_OK;
1324         }
1325 }
1326
1327 static void acpi_wmi_notify_handler(acpi_handle handle, u32 event,
1328                                     void *context)
1329 {
1330         struct wmi_block *wblock = NULL, *iter;
1331
1332         list_for_each_entry(iter, &wmi_block_list, list) {
1333                 struct guid_block *block = &iter->gblock;
1334
1335                 if (iter->acpi_device->handle == handle &&
1336                     (block->flags & ACPI_WMI_EVENT) &&
1337                     (block->notify_id == event)) {
1338                         wblock = iter;
1339                         break;
1340                 }
1341         }
1342
1343         if (!wblock)
1344                 return;
1345
1346         /* If a driver is bound, then notify the driver. */
1347         if (test_bit(WMI_PROBED, &wblock->flags) && wblock->dev.dev.driver) {
1348                 struct wmi_driver *driver = drv_to_wdrv(wblock->dev.dev.driver);
1349                 struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL };
1350                 acpi_status status;
1351
1352                 if (!driver->no_notify_data) {
1353                         status = get_event_data(wblock, &evdata);
1354                         if (ACPI_FAILURE(status)) {
1355                                 dev_warn(&wblock->dev.dev, "failed to get event data\n");
1356                                 return;
1357                         }
1358                 }
1359
1360                 if (driver->notify)
1361                         driver->notify(&wblock->dev, evdata.pointer);
1362
1363                 kfree(evdata.pointer);
1364         } else if (wblock->handler) {
1365                 /* Legacy handler */
1366                 wblock->handler(event, wblock->handler_data);
1367         }
1368
1369         if (debug_event)
1370                 pr_info("DEBUG: GUID %pUL event 0x%02X\n", &wblock->gblock.guid, event);
1371
1372         acpi_bus_generate_netlink_event(
1373                 wblock->acpi_device->pnp.device_class,
1374                 dev_name(&wblock->dev.dev),
1375                 event, 0);
1376 }
1377
1378 static int acpi_wmi_remove(struct platform_device *device)
1379 {
1380         struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev);
1381
1382         acpi_remove_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY,
1383                                    acpi_wmi_notify_handler);
1384         acpi_remove_address_space_handler(acpi_device->handle,
1385                                 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
1386         wmi_free_devices(acpi_device);
1387         device_unregister(dev_get_drvdata(&device->dev));
1388
1389         return 0;
1390 }
1391
1392 static int acpi_wmi_probe(struct platform_device *device)
1393 {
1394         struct acpi_device *acpi_device;
1395         struct device *wmi_bus_dev;
1396         acpi_status status;
1397         int error;
1398
1399         acpi_device = ACPI_COMPANION(&device->dev);
1400         if (!acpi_device) {
1401                 dev_err(&device->dev, "ACPI companion is missing\n");
1402                 return -ENODEV;
1403         }
1404
1405         status = acpi_install_address_space_handler(acpi_device->handle,
1406                                                     ACPI_ADR_SPACE_EC,
1407                                                     &acpi_wmi_ec_space_handler,
1408                                                     NULL, NULL);
1409         if (ACPI_FAILURE(status)) {
1410                 dev_err(&device->dev, "Error installing EC region handler\n");
1411                 return -ENODEV;
1412         }
1413
1414         status = acpi_install_notify_handler(acpi_device->handle,
1415                                              ACPI_ALL_NOTIFY,
1416                                              acpi_wmi_notify_handler,
1417                                              NULL);
1418         if (ACPI_FAILURE(status)) {
1419                 dev_err(&device->dev, "Error installing notify handler\n");
1420                 error = -ENODEV;
1421                 goto err_remove_ec_handler;
1422         }
1423
1424         wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0),
1425                                     NULL, "wmi_bus-%s", dev_name(&device->dev));
1426         if (IS_ERR(wmi_bus_dev)) {
1427                 error = PTR_ERR(wmi_bus_dev);
1428                 goto err_remove_notify_handler;
1429         }
1430         dev_set_drvdata(&device->dev, wmi_bus_dev);
1431
1432         error = parse_wdg(wmi_bus_dev, acpi_device);
1433         if (error) {
1434                 pr_err("Failed to parse WDG method\n");
1435                 goto err_remove_busdev;
1436         }
1437
1438         return 0;
1439
1440 err_remove_busdev:
1441         device_unregister(wmi_bus_dev);
1442
1443 err_remove_notify_handler:
1444         acpi_remove_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY,
1445                                    acpi_wmi_notify_handler);
1446
1447 err_remove_ec_handler:
1448         acpi_remove_address_space_handler(acpi_device->handle,
1449                                           ACPI_ADR_SPACE_EC,
1450                                           &acpi_wmi_ec_space_handler);
1451
1452         return error;
1453 }
1454
1455 int __must_check __wmi_driver_register(struct wmi_driver *driver,
1456                                        struct module *owner)
1457 {
1458         driver->driver.owner = owner;
1459         driver->driver.bus = &wmi_bus_type;
1460
1461         return driver_register(&driver->driver);
1462 }
1463 EXPORT_SYMBOL(__wmi_driver_register);
1464
1465 void wmi_driver_unregister(struct wmi_driver *driver)
1466 {
1467         driver_unregister(&driver->driver);
1468 }
1469 EXPORT_SYMBOL(wmi_driver_unregister);
1470
1471 static struct platform_driver acpi_wmi_driver = {
1472         .driver = {
1473                 .name = "acpi-wmi",
1474                 .acpi_match_table = wmi_device_ids,
1475         },
1476         .probe = acpi_wmi_probe,
1477         .remove = acpi_wmi_remove,
1478 };
1479
1480 static int __init acpi_wmi_init(void)
1481 {
1482         int error;
1483
1484         if (acpi_disabled)
1485                 return -ENODEV;
1486
1487         error = class_register(&wmi_bus_class);
1488         if (error)
1489                 return error;
1490
1491         error = bus_register(&wmi_bus_type);
1492         if (error)
1493                 goto err_unreg_class;
1494
1495         error = platform_driver_register(&acpi_wmi_driver);
1496         if (error) {
1497                 pr_err("Error loading mapper\n");
1498                 goto err_unreg_bus;
1499         }
1500
1501         return 0;
1502
1503 err_unreg_bus:
1504         bus_unregister(&wmi_bus_type);
1505
1506 err_unreg_class:
1507         class_unregister(&wmi_bus_class);
1508
1509         return error;
1510 }
1511
1512 static void __exit acpi_wmi_exit(void)
1513 {
1514         platform_driver_unregister(&acpi_wmi_driver);
1515         bus_unregister(&wmi_bus_type);
1516         class_unregister(&wmi_bus_class);
1517 }
1518
1519 subsys_initcall_sync(acpi_wmi_init);
1520 module_exit(acpi_wmi_exit);