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