drivers/platform/x86/wmi.c

   1 /*
   2  *  ACPI-WMI mapping driver
   3  *
   4  *  Copyright (C) 2007-2008 Carlos Corbacho <carlos@strangeworlds.co.uk>
   5  *
   6  *  GUID parsing code from ldm.c is:
   7  *   Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
   8  *   Copyright (c) 2001-2007 Anton Altaparmakov
   9  *   Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
  10  *
  11  *  WMI bus infrastructure by Andrew Lutomirski and Darren Hart:
  12  *    Copyright (C) 2015 Andrew Lutomirski
  13  *    Copyright (C) 2017 VMware, Inc. All Rights Reserved.
  14  *
  15  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  16  *
  17  *  This program is free software; you can redistribute it and/or modify
  18  *  it under the terms of the GNU General Public License as published by
  19  *  the Free Software Foundation; either version 2 of the License, or (at
  20  *  your option) any later version.
  21  *
  22  *  This program is distributed in the hope that it will be useful, but
  23  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  24  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  25  *  General Public License for more details.
  26  *
  27  *  You should have received a copy of the GNU General Public License along
  28  *  with this program; if not, write to the Free Software Foundation, Inc.,
  29  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  30  *
  31  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  32  */
  33
  34 #define pr_fmt(fmt)     KBUILD_MODNAME ": " fmt
  35
  36 #include <linux/acpi.h>
  37 #include <linux/device.h>
  38 #include <linux/init.h>
  39 #include <linux/kernel.h>
  40 #include <linux/list.h>
  41 #include <linux/miscdevice.h>
  42 #include <linux/module.h>
  43 #include <linux/platform_device.h>
  44 #include <linux/slab.h>
  45 #include <linux/types.h>
  46 #include <linux/uaccess.h>
  47 #include <linux/uuid.h>
  48 #include <linux/wmi.h>
  49 #include <uapi/linux/wmi.h>
  50
  51 ACPI_MODULE_NAME("wmi");
  52 MODULE_AUTHOR("Carlos Corbacho");
  53 MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
  54 MODULE_LICENSE("GPL");
  55
  56 static LIST_HEAD(wmi_block_list);
  57
  58 struct guid_block {
  59         char guid[16];
  60         union {
  61                 char object_id[2];
  62                 struct {
  63                         unsigned char notify_id;
  64                         unsigned char reserved;
  65                 };
  66         };
  67         u8 instance_count;
  68         u8 flags;
  69 };
  70
  71 struct wmi_block {
  72         struct wmi_device dev;
  73         struct list_head list;
  74         struct guid_block gblock;
  75         struct miscdevice char_dev;
  76         struct mutex char_mutex;
  77         struct acpi_device *acpi_device;
  78         wmi_notify_handler handler;
  79         void *handler_data;
  80         u64 req_buf_size;
  81
  82         bool read_takes_no_args;
  83 };
  84
  85
  86 /*
  87  * If the GUID data block is marked as expensive, we must enable and
  88  * explicitily disable data collection.
  89  */
  90 #define ACPI_WMI_EXPENSIVE   0x1
  91 #define ACPI_WMI_METHOD      0x2        /* GUID is a method */
  92 #define ACPI_WMI_STRING      0x4        /* GUID takes & returns a string */
  93 #define ACPI_WMI_EVENT       0x8        /* GUID is an event */
  94
  95 static bool debug_event;
  96 module_param(debug_event, bool, 0444);
  97 MODULE_PARM_DESC(debug_event,
  98                  "Log WMI Events [0/1]");
  99
 100 static bool debug_dump_wdg;
 101 module_param(debug_dump_wdg, bool, 0444);
 102 MODULE_PARM_DESC(debug_dump_wdg,
 103                  "Dump available WMI interfaces [0/1]");
 104
 105 static int acpi_wmi_remove(struct platform_device *device);
 106 static int acpi_wmi_probe(struct platform_device *device);
 107
 108 static const struct acpi_device_id wmi_device_ids[] = {
 109         {"PNP0C14", 0},
 110         {"pnp0c14", 0},
 111         {"", 0},
 112 };
 113 MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
 114
 115 static struct platform_driver acpi_wmi_driver = {
 116         .driver = {
 117                 .name = "acpi-wmi",
 118                 .acpi_match_table = wmi_device_ids,
 119         },
 120         .probe = acpi_wmi_probe,
 121         .remove = acpi_wmi_remove,
 122 };
 123
 124 /*
 125  * GUID parsing functions
 126  */
 127
 128 static bool find_guid(const char *guid_string, struct wmi_block **out)
 129 {
 130         uuid_le guid_input;
 131         struct wmi_block *wblock;
 132         struct guid_block *block;
 133
 134         if (uuid_le_to_bin(guid_string, &guid_input))
 135                 return false;
 136
 137         list_for_each_entry(wblock, &wmi_block_list, list) {
 138                 block = &wblock->gblock;
 139
 140                 if (memcmp(block->guid, &guid_input, 16) == 0) {
 141                         if (out)
 142                                 *out = wblock;
 143                         return true;
 144                 }
 145         }
 146         return false;
 147 }
 148
 149 static const void *find_guid_context(struct wmi_block *wblock,
 150                                       struct wmi_driver *wdriver)
 151 {
 152         const struct wmi_device_id *id;
 153         uuid_le guid_input;
 154
 155         if (wblock == NULL || wdriver == NULL)
 156                 return NULL;
 157         if (wdriver->id_table == NULL)
 158                 return NULL;
 159
 160         id = wdriver->id_table;
 161         while (*id->guid_string) {
 162                 if (uuid_le_to_bin(id->guid_string, &guid_input))
 163                         continue;
 164                 if (!memcmp(wblock->gblock.guid, &guid_input, 16))
 165                         return id->context;
 166                 id++;
 167         }
 168         return NULL;
 169 }
 170
 171 static int get_subobj_info(acpi_handle handle, const char *pathname,
 172                            struct acpi_device_info **info)
 173 {
 174         struct acpi_device_info *dummy_info, **info_ptr;
 175         acpi_handle subobj_handle;
 176         acpi_status status;
 177
 178         status = acpi_get_handle(handle, (char *)pathname, &subobj_handle);
 179         if (status == AE_NOT_FOUND)
 180                 return -ENOENT;
 181         else if (ACPI_FAILURE(status))
 182                 return -EIO;
 183
 184         info_ptr = info ? info : &dummy_info;
 185         status = acpi_get_object_info(subobj_handle, info_ptr);
 186         if (ACPI_FAILURE(status))
 187                 return -EIO;
 188
 189         if (!info)
 190                 kfree(dummy_info);
 191
 192         return 0;
 193 }
 194
 195 static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable)
 196 {
 197         struct guid_block *block = NULL;
 198         char method[5];
 199         acpi_status status;
 200         acpi_handle handle;
 201
 202         block = &wblock->gblock;
 203         handle = wblock->acpi_device->handle;
 204
 205         snprintf(method, 5, "WE%02X", block->notify_id);
 206         status = acpi_execute_simple_method(handle, method, enable);
 207
 208         if (status != AE_OK && status != AE_NOT_FOUND)
 209                 return status;
 210         else
 211                 return AE_OK;
 212 }
 213
 214 /*
 215  * Exported WMI functions
 216  */
 217
 218 /**
 219  * set_required_buffer_size - Sets the buffer size needed for performing IOCTL
 220  * @wdev: A wmi bus device from a driver
 221  * @instance: Instance index
 222  *
 223  * Allocates memory needed for buffer, stores the buffer size in that memory
 224  */
 225 int set_required_buffer_size(struct wmi_device *wdev, u64 length)
 226 {
 227         struct wmi_block *wblock;
 228
 229         wblock = container_of(wdev, struct wmi_block, dev);
 230         wblock->req_buf_size = length;
 231
 232         return 0;
 233 }
 234 EXPORT_SYMBOL_GPL(set_required_buffer_size);
 235
 236 /**
 237  * wmi_evaluate_method - Evaluate a WMI method
 238  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 239  * @instance: Instance index
 240  * @method_id: Method ID to call
 241  * &in: Buffer containing input for the method call
 242  * &out: Empty buffer to return the method results
 243  *
 244  * Call an ACPI-WMI method
 245  */
 246 acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
 247 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
 248 {
 249         struct wmi_block *wblock = NULL;
 250
 251         if (!find_guid(guid_string, &wblock))
 252                 return AE_ERROR;
 253         return wmidev_evaluate_method(&wblock->dev, instance, method_id,
 254                                       in, out);
 255 }
 256 EXPORT_SYMBOL_GPL(wmi_evaluate_method);
 257
 258 /**
 259  * wmidev_evaluate_method - Evaluate a WMI method
 260  * @wdev: A wmi bus device from a driver
 261  * @instance: Instance index
 262  * @method_id: Method ID to call
 263  * &in: Buffer containing input for the method call
 264  * &out: Empty buffer to return the method results
 265  *
 266  * Call an ACPI-WMI method
 267  */
 268 acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance,
 269         u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
 270 {
 271         struct guid_block *block = NULL;
 272         struct wmi_block *wblock = NULL;
 273         acpi_handle handle;
 274         acpi_status status;
 275         struct acpi_object_list input;
 276         union acpi_object params[3];
 277         char method[5] = "WM";
 278
 279         wblock = container_of(wdev, struct wmi_block, dev);
 280         block = &wblock->gblock;
 281         handle = wblock->acpi_device->handle;
 282
 283         if (!(block->flags & ACPI_WMI_METHOD))
 284                 return AE_BAD_DATA;
 285
 286         if (block->instance_count <= instance)
 287                 return AE_BAD_PARAMETER;
 288
 289         input.count = 2;
 290         input.pointer = params;
 291         params[0].type = ACPI_TYPE_INTEGER;
 292         params[0].integer.value = instance;
 293         params[1].type = ACPI_TYPE_INTEGER;
 294         params[1].integer.value = method_id;
 295
 296         if (in) {
 297                 input.count = 3;
 298
 299                 if (block->flags & ACPI_WMI_STRING) {
 300                         params[2].type = ACPI_TYPE_STRING;
 301                 } else {
 302                         params[2].type = ACPI_TYPE_BUFFER;
 303                 }
 304                 params[2].buffer.length = in->length;
 305                 params[2].buffer.pointer = in->pointer;
 306         }
 307
 308         strncat(method, block->object_id, 2);
 309
 310         status = acpi_evaluate_object(handle, method, &input, out);
 311
 312         return status;
 313 }
 314 EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
 315
 316 static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
 317                                  struct acpi_buffer *out)
 318 {
 319         struct guid_block *block = NULL;
 320         acpi_handle handle;
 321         acpi_status status, wc_status = AE_ERROR;
 322         struct acpi_object_list input;
 323         union acpi_object wq_params[1];
 324         char method[5];
 325         char wc_method[5] = "WC";
 326
 327         if (!out)
 328                 return AE_BAD_PARAMETER;
 329
 330         block = &wblock->gblock;
 331         handle = wblock->acpi_device->handle;
 332
 333         if (block->instance_count <= instance)
 334                 return AE_BAD_PARAMETER;
 335
 336         /* Check GUID is a data block */
 337         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 338                 return AE_ERROR;
 339
 340         input.count = 1;
 341         input.pointer = wq_params;
 342         wq_params[0].type = ACPI_TYPE_INTEGER;
 343         wq_params[0].integer.value = instance;
 344
 345         if (instance == 0 && wblock->read_takes_no_args)
 346                 input.count = 0;
 347
 348         /*
 349          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
 350          * enable collection.
 351          */
 352         if (block->flags & ACPI_WMI_EXPENSIVE) {
 353                 strncat(wc_method, block->object_id, 2);
 354
 355                 /*
 356                  * Some GUIDs break the specification by declaring themselves
 357                  * expensive, but have no corresponding WCxx method. So we
 358                  * should not fail if this happens.
 359                  */
 360                 if (acpi_has_method(handle, wc_method))
 361                         wc_status = acpi_execute_simple_method(handle,
 362                                                                 wc_method, 1);
 363         }
 364
 365         strcpy(method, "WQ");
 366         strncat(method, block->object_id, 2);
 367
 368         status = acpi_evaluate_object(handle, method, &input, out);
 369
 370         /*
 371          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
 372          * the WQxx method failed - we should disable collection anyway.
 373          */
 374         if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
 375                 status = acpi_execute_simple_method(handle, wc_method, 0);
 376         }
 377
 378         return status;
 379 }
 380
 381 /**
 382  * wmi_query_block - Return contents of a WMI block (deprecated)
 383  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 384  * @instance: Instance index
 385  * &out: Empty buffer to return the contents of the data block to
 386  *
 387  * Return the contents of an ACPI-WMI data block to a buffer
 388  */
 389 acpi_status wmi_query_block(const char *guid_string, u8 instance,
 390                             struct acpi_buffer *out)
 391 {
 392         struct wmi_block *wblock;
 393
 394         if (!guid_string)
 395                 return AE_BAD_PARAMETER;
 396
 397         if (!find_guid(guid_string, &wblock))
 398                 return AE_ERROR;
 399
 400         return __query_block(wblock, instance, out);
 401 }
 402 EXPORT_SYMBOL_GPL(wmi_query_block);
 403
 404 union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
 405 {
 406         struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
 407         struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
 408
 409         if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
 410                 return NULL;
 411
 412         return (union acpi_object *)out.pointer;
 413 }
 414 EXPORT_SYMBOL_GPL(wmidev_block_query);
 415
 416 /**
 417  * wmi_set_block - Write to a WMI block
 418  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 419  * @instance: Instance index
 420  * &in: Buffer containing new values for the data block
 421  *
 422  * Write the contents of the input buffer to an ACPI-WMI data block
 423  */
 424 acpi_status wmi_set_block(const char *guid_string, u8 instance,
 425                           const struct acpi_buffer *in)
 426 {
 427         struct guid_block *block = NULL;
 428         struct wmi_block *wblock = NULL;
 429         acpi_handle handle;
 430         struct acpi_object_list input;
 431         union acpi_object params[2];
 432         char method[5] = "WS";
 433
 434         if (!guid_string || !in)
 435                 return AE_BAD_DATA;
 436
 437         if (!find_guid(guid_string, &wblock))
 438                 return AE_ERROR;
 439
 440         block = &wblock->gblock;
 441         handle = wblock->acpi_device->handle;
 442
 443         if (block->instance_count <= instance)
 444                 return AE_BAD_PARAMETER;
 445
 446         /* Check GUID is a data block */
 447         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 448                 return AE_ERROR;
 449
 450         input.count = 2;
 451         input.pointer = params;
 452         params[0].type = ACPI_TYPE_INTEGER;
 453         params[0].integer.value = instance;
 454
 455         if (block->flags & ACPI_WMI_STRING) {
 456                 params[1].type = ACPI_TYPE_STRING;
 457         } else {
 458                 params[1].type = ACPI_TYPE_BUFFER;
 459         }
 460         params[1].buffer.length = in->length;
 461         params[1].buffer.pointer = in->pointer;
 462
 463         strncat(method, block->object_id, 2);
 464
 465         return acpi_evaluate_object(handle, method, &input, NULL);
 466 }
 467 EXPORT_SYMBOL_GPL(wmi_set_block);
 468
 469 static void wmi_dump_wdg(const struct guid_block *g)
 470 {
 471         pr_info("%pUL:\n", g->guid);
 472         if (g->flags & ACPI_WMI_EVENT)
 473                 pr_info("\tnotify_id: 0x%02X\n", g->notify_id);
 474         else
 475                 pr_info("\tobject_id: %2pE\n", g->object_id);
 476         pr_info("\tinstance_count: %d\n", g->instance_count);
 477         pr_info("\tflags: %#x", g->flags);
 478         if (g->flags) {
 479                 if (g->flags & ACPI_WMI_EXPENSIVE)
 480                         pr_cont(" ACPI_WMI_EXPENSIVE");
 481                 if (g->flags & ACPI_WMI_METHOD)
 482                         pr_cont(" ACPI_WMI_METHOD");
 483                 if (g->flags & ACPI_WMI_STRING)
 484                         pr_cont(" ACPI_WMI_STRING");
 485                 if (g->flags & ACPI_WMI_EVENT)
 486                         pr_cont(" ACPI_WMI_EVENT");
 487         }
 488         pr_cont("\n");
 489
 490 }
 491
 492 static void wmi_notify_debug(u32 value, void *context)
 493 {
 494         struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
 495         union acpi_object *obj;
 496         acpi_status status;
 497
 498         status = wmi_get_event_data(value, &response);
 499         if (status != AE_OK) {
 500                 pr_info("bad event status 0x%x\n", status);
 501                 return;
 502         }
 503
 504         obj = (union acpi_object *)response.pointer;
 505
 506         if (!obj)
 507                 return;
 508
 509         pr_info("DEBUG Event ");
 510         switch(obj->type) {
 511         case ACPI_TYPE_BUFFER:
 512                 pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
 513                 break;
 514         case ACPI_TYPE_STRING:
 515                 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
 516                 break;
 517         case ACPI_TYPE_INTEGER:
 518                 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
 519                 break;
 520         case ACPI_TYPE_PACKAGE:
 521                 pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
 522                 break;
 523         default:
 524                 pr_cont("object type 0x%X\n", obj->type);
 525         }
 526         kfree(obj);
 527 }
 528
 529 /**
 530  * wmi_install_notify_handler - Register handler for WMI events
 531  * @handler: Function to handle notifications
 532  * @data: Data to be returned to handler when event is fired
 533  *
 534  * Register a handler for events sent to the ACPI-WMI mapper device.
 535  */
 536 acpi_status wmi_install_notify_handler(const char *guid,
 537 wmi_notify_handler handler, void *data)
 538 {
 539         struct wmi_block *block;
 540         acpi_status status = AE_NOT_EXIST;
 541         uuid_le guid_input;
 542
 543         if (!guid || !handler)
 544                 return AE_BAD_PARAMETER;
 545
 546         if (uuid_le_to_bin(guid, &guid_input))
 547                 return AE_BAD_PARAMETER;
 548
 549         list_for_each_entry(block, &wmi_block_list, list) {
 550                 acpi_status wmi_status;
 551
 552                 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
 553                         if (block->handler &&
 554                             block->handler != wmi_notify_debug)
 555                                 return AE_ALREADY_ACQUIRED;
 556
 557                         block->handler = handler;
 558                         block->handler_data = data;
 559
 560                         wmi_status = wmi_method_enable(block, 1);
 561                         if ((wmi_status != AE_OK) ||
 562                             ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
 563                                 status = wmi_status;
 564                 }
 565         }
 566
 567         return status;
 568 }
 569 EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
 570
 571 /**
 572  * wmi_uninstall_notify_handler - Unregister handler for WMI events
 573  *
 574  * Unregister handler for events sent to the ACPI-WMI mapper device.
 575  */
 576 acpi_status wmi_remove_notify_handler(const char *guid)
 577 {
 578         struct wmi_block *block;
 579         acpi_status status = AE_NOT_EXIST;
 580         uuid_le guid_input;
 581
 582         if (!guid)
 583                 return AE_BAD_PARAMETER;
 584
 585         if (uuid_le_to_bin(guid, &guid_input))
 586                 return AE_BAD_PARAMETER;
 587
 588         list_for_each_entry(block, &wmi_block_list, list) {
 589                 acpi_status wmi_status;
 590
 591                 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
 592                         if (!block->handler ||
 593                             block->handler == wmi_notify_debug)
 594                                 return AE_NULL_ENTRY;
 595
 596                         if (debug_event) {
 597                                 block->handler = wmi_notify_debug;
 598                                 status = AE_OK;
 599                         } else {
 600                                 wmi_status = wmi_method_enable(block, 0);
 601                                 block->handler = NULL;
 602                                 block->handler_data = NULL;
 603                                 if ((wmi_status != AE_OK) ||
 604                                     ((wmi_status == AE_OK) &&
 605                                      (status == AE_NOT_EXIST)))
 606                                         status = wmi_status;
 607                         }
 608                 }
 609         }
 610
 611         return status;
 612 }
 613 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
 614
 615 /**
 616  * wmi_get_event_data - Get WMI data associated with an event
 617  *
 618  * @event: Event to find
 619  * @out: Buffer to hold event data. out->pointer should be freed with kfree()
 620  *
 621  * Returns extra data associated with an event in WMI.
 622  */
 623 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
 624 {
 625         struct acpi_object_list input;
 626         union acpi_object params[1];
 627         struct guid_block *gblock;
 628         struct wmi_block *wblock;
 629
 630         input.count = 1;
 631         input.pointer = params;
 632         params[0].type = ACPI_TYPE_INTEGER;
 633         params[0].integer.value = event;
 634
 635         list_for_each_entry(wblock, &wmi_block_list, list) {
 636                 gblock = &wblock->gblock;
 637
 638                 if ((gblock->flags & ACPI_WMI_EVENT) &&
 639                         (gblock->notify_id == event))
 640                         return acpi_evaluate_object(wblock->acpi_device->handle,
 641                                 "_WED", &input, out);
 642         }
 643
 644         return AE_NOT_FOUND;
 645 }
 646 EXPORT_SYMBOL_GPL(wmi_get_event_data);
 647
 648 /**
 649  * wmi_has_guid - Check if a GUID is available
 650  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 651  *
 652  * Check if a given GUID is defined by _WDG
 653  */
 654 bool wmi_has_guid(const char *guid_string)
 655 {
 656         return find_guid(guid_string, NULL);
 657 }
 658 EXPORT_SYMBOL_GPL(wmi_has_guid);
 659
 660 /**
 661  * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID
 662  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 663  *
 664  * Find the _UID of ACPI device associated with this WMI GUID.
 665  *
 666  * Return: The ACPI _UID field value or NULL if the WMI GUID was not found
 667  */
 668 char *wmi_get_acpi_device_uid(const char *guid_string)
 669 {
 670         struct wmi_block *wblock = NULL;
 671
 672         if (!find_guid(guid_string, &wblock))
 673                 return NULL;
 674
 675         return acpi_device_uid(wblock->acpi_device);
 676 }
 677 EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
 678
 679 static struct wmi_block *dev_to_wblock(struct device *dev)
 680 {
 681         return container_of(dev, struct wmi_block, dev.dev);
 682 }
 683
 684 static struct wmi_device *dev_to_wdev(struct device *dev)
 685 {
 686         return container_of(dev, struct wmi_device, dev);
 687 }
 688
 689 /*
 690  * sysfs interface
 691  */
 692 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 693                              char *buf)
 694 {
 695         struct wmi_block *wblock = dev_to_wblock(dev);
 696
 697         return sprintf(buf, "wmi:%pUL\n", wblock->gblock.guid);
 698 }
 699 static DEVICE_ATTR_RO(modalias);
 700
 701 static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
 702                          char *buf)
 703 {
 704         struct wmi_block *wblock = dev_to_wblock(dev);
 705
 706         return sprintf(buf, "%pUL\n", wblock->gblock.guid);
 707 }
 708 static DEVICE_ATTR_RO(guid);
 709
 710 static ssize_t instance_count_show(struct device *dev,
 711                                    struct device_attribute *attr, char *buf)
 712 {
 713         struct wmi_block *wblock = dev_to_wblock(dev);
 714
 715         return sprintf(buf, "%d\n", (int)wblock->gblock.instance_count);
 716 }
 717 static DEVICE_ATTR_RO(instance_count);
 718
 719 static ssize_t expensive_show(struct device *dev,
 720                               struct device_attribute *attr, char *buf)
 721 {
 722         struct wmi_block *wblock = dev_to_wblock(dev);
 723
 724         return sprintf(buf, "%d\n",
 725                        (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
 726 }
 727 static DEVICE_ATTR_RO(expensive);
 728
 729 static struct attribute *wmi_attrs[] = {
 730         &dev_attr_modalias.attr,
 731         &dev_attr_guid.attr,
 732         &dev_attr_instance_count.attr,
 733         &dev_attr_expensive.attr,
 734         NULL,
 735 };
 736 ATTRIBUTE_GROUPS(wmi);
 737
 738 static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
 739                               char *buf)
 740 {
 741         struct wmi_block *wblock = dev_to_wblock(dev);
 742
 743         return sprintf(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
 744 }
 745 static DEVICE_ATTR_RO(notify_id);
 746
 747 static struct attribute *wmi_event_attrs[] = {
 748         &dev_attr_notify_id.attr,
 749         NULL,
 750 };
 751 ATTRIBUTE_GROUPS(wmi_event);
 752
 753 static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
 754                               char *buf)
 755 {
 756         struct wmi_block *wblock = dev_to_wblock(dev);
 757
 758         return sprintf(buf, "%c%c\n", wblock->gblock.object_id[0],
 759                        wblock->gblock.object_id[1]);
 760 }
 761 static DEVICE_ATTR_RO(object_id);
 762
 763 static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
 764                             char *buf)
 765 {
 766         struct wmi_device *wdev = dev_to_wdev(dev);
 767
 768         return sprintf(buf, "%d\n", (int)wdev->setable);
 769 }
 770 static DEVICE_ATTR_RO(setable);
 771
 772 static struct attribute *wmi_data_attrs[] = {
 773         &dev_attr_object_id.attr,
 774         &dev_attr_setable.attr,
 775         NULL,
 776 };
 777 ATTRIBUTE_GROUPS(wmi_data);
 778
 779 static struct attribute *wmi_method_attrs[] = {
 780         &dev_attr_object_id.attr,
 781         NULL,
 782 };
 783 ATTRIBUTE_GROUPS(wmi_method);
 784
 785 static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 786 {
 787         struct wmi_block *wblock = dev_to_wblock(dev);
 788
 789         if (add_uevent_var(env, "MODALIAS=wmi:%pUL", wblock->gblock.guid))
 790                 return -ENOMEM;
 791
 792         if (add_uevent_var(env, "WMI_GUID=%pUL", wblock->gblock.guid))
 793                 return -ENOMEM;
 794
 795         return 0;
 796 }
 797
 798 static void wmi_dev_release(struct device *dev)
 799 {
 800         struct wmi_block *wblock = dev_to_wblock(dev);
 801
 802         kfree(wblock);
 803 }
 804
 805 static int wmi_dev_match(struct device *dev, struct device_driver *driver)
 806 {
 807         struct wmi_driver *wmi_driver =
 808                 container_of(driver, struct wmi_driver, driver);
 809         struct wmi_block *wblock = dev_to_wblock(dev);
 810         const struct wmi_device_id *id = wmi_driver->id_table;
 811
 812         if (id == NULL)
 813                 return 0;
 814
 815         while (*id->guid_string) {
 816                 uuid_le driver_guid;
 817
 818                 if (WARN_ON(uuid_le_to_bin(id->guid_string, &driver_guid)))
 819                         continue;
 820                 if (!memcmp(&driver_guid, wblock->gblock.guid, 16))
 821                         return 1;
 822
 823                 id++;
 824         }
 825
 826         return 0;
 827 }
 828 static int wmi_char_open(struct inode *inode, struct file *filp)
 829 {
 830         const char *driver_name = filp->f_path.dentry->d_iname;
 831         struct wmi_block *wblock = NULL;
 832         struct wmi_block *next = NULL;
 833
 834         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
 835                 if (!wblock->dev.dev.driver)
 836                         continue;
 837                 if (strcmp(driver_name, wblock->dev.dev.driver->name) == 0) {
 838                         filp->private_data = wblock;
 839                         break;
 840                 }
 841         }
 842
 843         if (!filp->private_data)
 844                 return -ENODEV;
 845
 846         return nonseekable_open(inode, filp);
 847 }
 848
 849 static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
 850         size_t length, loff_t *offset)
 851 {
 852         struct wmi_block *wblock = filp->private_data;
 853
 854         return simple_read_from_buffer(buffer, length, offset,
 855                                        &wblock->req_buf_size,
 856                                        sizeof(wblock->req_buf_size));
 857 }
 858
 859 static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 860 {
 861         struct wmi_ioctl_buffer __user *input =
 862                 (struct wmi_ioctl_buffer __user *) arg;
 863         struct wmi_block *wblock = filp->private_data;
 864         struct wmi_ioctl_buffer *buf = NULL;
 865         struct wmi_driver *wdriver = NULL;
 866         int ret;
 867
 868         if (_IOC_TYPE(cmd) != WMI_IOC)
 869                 return -ENOTTY;
 870
 871         /* make sure we're not calling a higher instance than exists*/
 872         if (_IOC_NR(cmd) >= wblock->gblock.instance_count)
 873                 return -EINVAL;
 874
 875         mutex_lock(&wblock->char_mutex);
 876         buf = wblock->handler_data;
 877         if (get_user(buf->length, &input->length)) {
 878                 dev_dbg(&wblock->dev.dev, "Read length from user failed\n");
 879                 ret = -EFAULT;
 880                 goto out_ioctl;
 881         }
 882         /* if it's too small, abort */
 883         if (buf->length < wblock->req_buf_size) {
 884                 dev_err(&wblock->dev.dev,
 885                         "Buffer %lld too small, need at least %lld\n",
 886                         buf->length, wblock->req_buf_size);
 887                 ret = -EINVAL;
 888                 goto out_ioctl;
 889         }
 890         /* if it's too big, warn, driver will only use what is needed */
 891         if (buf->length > wblock->req_buf_size)
 892                 dev_warn(&wblock->dev.dev,
 893                         "Buffer %lld is bigger than required %lld\n",
 894                         buf->length, wblock->req_buf_size);
 895
 896         /* copy the structure from userspace */
 897         if (copy_from_user(buf, input, wblock->req_buf_size)) {
 898                 dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n",
 899                         wblock->req_buf_size);
 900                 ret = -EFAULT;
 901                 goto out_ioctl;
 902         }
 903
 904         /* let the driver do any filtering and do the call */
 905         wdriver = container_of(wblock->dev.dev.driver,
 906                                struct wmi_driver, driver);
 907         if (!try_module_get(wdriver->driver.owner)) {
 908                 ret = -EBUSY;
 909                 goto out_ioctl;
 910         }
 911         ret = wdriver->filter_callback(&wblock->dev, cmd, buf);
 912         module_put(wdriver->driver.owner);
 913         if (ret)
 914                 goto out_ioctl;
 915
 916         /* return the result (only up to our internal buffer size) */
 917         if (copy_to_user(input, buf, wblock->req_buf_size)) {
 918                 dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n",
 919                         wblock->req_buf_size);
 920                 ret = -EFAULT;
 921         }
 922
 923 out_ioctl:
 924         mutex_unlock(&wblock->char_mutex);
 925         return ret;
 926 }
 927
 928 static const struct file_operations wmi_fops = {
 929         .owner          = THIS_MODULE,
 930         .read           = wmi_char_read,
 931         .open           = wmi_char_open,
 932         .unlocked_ioctl = wmi_ioctl,
 933         .compat_ioctl   = wmi_ioctl,
 934 };
 935
 936 static int wmi_dev_probe(struct device *dev)
 937 {
 938         struct wmi_block *wblock = dev_to_wblock(dev);
 939         struct wmi_driver *wdriver =
 940                 container_of(dev->driver, struct wmi_driver, driver);
 941         int ret = 0;
 942         char *buf;
 943
 944         if (ACPI_FAILURE(wmi_method_enable(wblock, 1)))
 945                 dev_warn(dev, "failed to enable device -- probing anyway\n");
 946
 947         if (wdriver->probe) {
 948                 ret = wdriver->probe(dev_to_wdev(dev));
 949                 if (ret != 0)
 950                         goto probe_failure;
 951         }
 952
 953         /* driver wants a character device made */
 954         if (wdriver->filter_callback) {
 955                 /* check that required buffer size declared by driver or MOF */
 956                 if (!wblock->req_buf_size) {
 957                         dev_err(&wblock->dev.dev,
 958                                 "Required buffer size not set\n");
 959                         ret = -EINVAL;
 960                         goto probe_failure;
 961                 }
 962
 963                 wblock->handler_data = kmalloc(wblock->req_buf_size,
 964                                                GFP_KERNEL);
 965                 if (!wblock->handler_data) {
 966                         ret = -ENOMEM;
 967                         goto probe_failure;
 968                 }
 969
 970                 buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name);
 971                 if (!buf) {
 972                         ret = -ENOMEM;
 973                         goto probe_string_failure;
 974                 }
 975                 wblock->char_dev.minor = MISC_DYNAMIC_MINOR;
 976                 wblock->char_dev.name = buf;
 977                 wblock->char_dev.fops = &wmi_fops;
 978                 wblock->char_dev.mode = 0444;
 979                 ret = misc_register(&wblock->char_dev);
 980                 if (ret) {
 981                         dev_warn(dev, "failed to register char dev: %d\n", ret);
 982                         ret = -ENOMEM;
 983                         goto probe_misc_failure;
 984                 }
 985         }
 986
 987         return 0;
 988
 989 probe_misc_failure:
 990         kfree(buf);
 991 probe_string_failure:
 992         kfree(wblock->handler_data);
 993 probe_failure:
 994         if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
 995                 dev_warn(dev, "failed to disable device\n");
 996         return ret;
 997 }
 998
 999 static int wmi_dev_remove(struct device *dev)
1000 {
1001         struct wmi_block *wblock = dev_to_wblock(dev);
1002         struct wmi_driver *wdriver =
1003                 container_of(dev->driver, struct wmi_driver, driver);
1004         int ret = 0;
1005
1006         if (wdriver->filter_callback) {
1007                 misc_deregister(&wblock->char_dev);
1008                 kfree(wblock->char_dev.name);
1009                 kfree(wblock->handler_data);
1010         }
1011
1012         if (wdriver->remove)
1013                 ret = wdriver->remove(dev_to_wdev(dev));
1014
1015         if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
1016                 dev_warn(dev, "failed to disable device\n");
1017
1018         return ret;
1019 }
1020
1021 static struct class wmi_bus_class = {
1022         .name = "wmi_bus",
1023 };
1024
1025 static struct bus_type wmi_bus_type = {
1026         .name = "wmi",
1027         .dev_groups = wmi_groups,
1028         .match = wmi_dev_match,
1029         .uevent = wmi_dev_uevent,
1030         .probe = wmi_dev_probe,
1031         .remove = wmi_dev_remove,
1032 };
1033
1034 static const struct device_type wmi_type_event = {
1035         .name = "event",
1036         .groups = wmi_event_groups,
1037         .release = wmi_dev_release,
1038 };
1039
1040 static const struct device_type wmi_type_method = {
1041         .name = "method",
1042         .groups = wmi_method_groups,
1043         .release = wmi_dev_release,
1044 };
1045
1046 static const struct device_type wmi_type_data = {
1047         .name = "data",
1048         .groups = wmi_data_groups,
1049         .release = wmi_dev_release,
1050 };
1051
1052 static int wmi_create_device(struct device *wmi_bus_dev,
1053                              const struct guid_block *gblock,
1054                              struct wmi_block *wblock,
1055                              struct acpi_device *device)
1056 {
1057         struct acpi_device_info *info;
1058         char method[5];
1059         int result;
1060
1061         if (gblock->flags & ACPI_WMI_EVENT) {
1062                 wblock->dev.dev.type = &wmi_type_event;
1063                 goto out_init;
1064         }
1065
1066         if (gblock->flags & ACPI_WMI_METHOD) {
1067                 wblock->dev.dev.type = &wmi_type_method;
1068                 mutex_init(&wblock->char_mutex);
1069                 goto out_init;
1070         }
1071
1072         /*
1073          * Data Block Query Control Method (WQxx by convention) is
1074          * required per the WMI documentation. If it is not present,
1075          * we ignore this data block.
1076          */
1077         strcpy(method, "WQ");
1078         strncat(method, wblock->gblock.object_id, 2);
1079         result = get_subobj_info(device->handle, method, &info);
1080
1081         if (result) {
1082                 dev_warn(wmi_bus_dev,
1083                          "%s data block query control method not found\n",
1084                          method);
1085                 return result;
1086         }
1087
1088         wblock->dev.dev.type = &wmi_type_data;
1089
1090         /*
1091          * The Microsoft documentation specifically states:
1092          *
1093          *   Data blocks registered with only a single instance
1094          *   can ignore the parameter.
1095          *
1096          * ACPICA will get mad at us if we call the method with the wrong number
1097          * of arguments, so check what our method expects.  (On some Dell
1098          * laptops, WQxx may not be a method at all.)
1099          */
1100         if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1101                 wblock->read_takes_no_args = true;
1102
1103         kfree(info);
1104
1105         strcpy(method, "WS");
1106         strncat(method, wblock->gblock.object_id, 2);
1107         result = get_subobj_info(device->handle, method, NULL);
1108
1109         if (result == 0)
1110                 wblock->dev.setable = true;
1111
1112  out_init:
1113         wblock->dev.dev.bus = &wmi_bus_type;
1114         wblock->dev.dev.parent = wmi_bus_dev;
1115
1116         dev_set_name(&wblock->dev.dev, "%pUL", gblock->guid);
1117
1118         device_initialize(&wblock->dev.dev);
1119
1120         return 0;
1121 }
1122
1123 static void wmi_free_devices(struct acpi_device *device)
1124 {
1125         struct wmi_block *wblock, *next;
1126
1127         /* Delete devices for all the GUIDs */
1128         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1129                 if (wblock->acpi_device == device) {
1130                         list_del(&wblock->list);
1131                         device_unregister(&wblock->dev.dev);
1132                 }
1133         }
1134 }
1135
1136 static bool guid_already_parsed(struct acpi_device *device,
1137                                 const u8 *guid)
1138 {
1139         struct wmi_block *wblock;
1140
1141         list_for_each_entry(wblock, &wmi_block_list, list) {
1142                 if (memcmp(wblock->gblock.guid, guid, 16) == 0) {
1143                         /*
1144                          * Because we historically didn't track the relationship
1145                          * between GUIDs and ACPI nodes, we don't know whether
1146                          * we need to suppress GUIDs that are unique on a
1147                          * given node but duplicated across nodes.
1148                          */
1149                         dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
1150                                  guid, dev_name(&wblock->acpi_device->dev));
1151                         return true;
1152                 }
1153         }
1154
1155         return false;
1156 }
1157
1158 /*
1159  * Parse the _WDG method for the GUID data blocks
1160  */
1161 static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
1162 {
1163         struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1164         const struct guid_block *gblock;
1165         struct wmi_block *wblock, *next;
1166         union acpi_object *obj;
1167         acpi_status status;
1168         int retval = 0;
1169         u32 i, total;
1170
1171         status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1172         if (ACPI_FAILURE(status))
1173                 return -ENXIO;
1174
1175         obj = (union acpi_object *) out.pointer;
1176         if (!obj)
1177                 return -ENXIO;
1178
1179         if (obj->type != ACPI_TYPE_BUFFER) {
1180                 retval = -ENXIO;
1181                 goto out_free_pointer;
1182         }
1183
1184         gblock = (const struct guid_block *)obj->buffer.pointer;
1185         total = obj->buffer.length / sizeof(struct guid_block);
1186
1187         for (i = 0; i < total; i++) {
1188                 if (debug_dump_wdg)
1189                         wmi_dump_wdg(&gblock[i]);
1190
1191                 /*
1192                  * Some WMI devices, like those for nVidia hooks, have a
1193                  * duplicate GUID. It's not clear what we should do in this
1194                  * case yet, so for now, we'll just ignore the duplicate
1195                  * for device creation.
1196                  */
1197                 if (guid_already_parsed(device, gblock[i].guid))
1198                         continue;
1199
1200                 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
1201                 if (!wblock) {
1202                         retval = -ENOMEM;
1203                         break;
1204                 }
1205
1206                 wblock->acpi_device = device;
1207                 wblock->gblock = gblock[i];
1208
1209                 retval = wmi_create_device(wmi_bus_dev, &gblock[i], wblock, device);
1210                 if (retval) {
1211                         kfree(wblock);
1212                         continue;
1213                 }
1214
1215                 list_add_tail(&wblock->list, &wmi_block_list);
1216
1217                 if (debug_event) {
1218                         wblock->handler = wmi_notify_debug;
1219                         wmi_method_enable(wblock, 1);
1220                 }
1221         }
1222
1223         /*
1224          * Now that all of the devices are created, add them to the
1225          * device tree and probe subdrivers.
1226          */
1227         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1228                 if (wblock->acpi_device != device)
1229                         continue;
1230
1231                 retval = device_add(&wblock->dev.dev);
1232                 if (retval) {
1233                         dev_err(wmi_bus_dev, "failed to register %pUL\n",
1234                                 wblock->gblock.guid);
1235                         if (debug_event)
1236                                 wmi_method_enable(wblock, 0);
1237                         list_del(&wblock->list);
1238                         put_device(&wblock->dev.dev);
1239                 }
1240         }
1241
1242 out_free_pointer:
1243         kfree(out.pointer);
1244         return retval;
1245 }
1246
1247 /*
1248  * WMI can have EmbeddedControl access regions. In which case, we just want to
1249  * hand these off to the EC driver.
1250  */
1251 static acpi_status
1252 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1253                       u32 bits, u64 *value,
1254                       void *handler_context, void *region_context)
1255 {
1256         int result = 0, i = 0;
1257         u8 temp = 0;
1258
1259         if ((address > 0xFF) || !value)
1260                 return AE_BAD_PARAMETER;
1261
1262         if (function != ACPI_READ && function != ACPI_WRITE)
1263                 return AE_BAD_PARAMETER;
1264
1265         if (bits != 8)
1266                 return AE_BAD_PARAMETER;
1267
1268         if (function == ACPI_READ) {
1269                 result = ec_read(address, &temp);
1270                 (*value) |= ((u64)temp) << i;
1271         } else {
1272                 temp = 0xff & ((*value) >> i);
1273                 result = ec_write(address, temp);
1274         }
1275
1276         switch (result) {
1277         case -EINVAL:
1278                 return AE_BAD_PARAMETER;
1279                 break;
1280         case -ENODEV:
1281                 return AE_NOT_FOUND;
1282                 break;
1283         case -ETIME:
1284                 return AE_TIME;
1285                 break;
1286         default:
1287                 return AE_OK;
1288         }
1289 }
1290
1291 static void acpi_wmi_notify_handler(acpi_handle handle, u32 event,
1292                                     void *context)
1293 {
1294         struct guid_block *block;
1295         struct wmi_block *wblock;
1296         bool found_it = false;
1297
1298         list_for_each_entry(wblock, &wmi_block_list, list) {
1299                 block = &wblock->gblock;
1300
1301                 if (wblock->acpi_device->handle == handle &&
1302                     (block->flags & ACPI_WMI_EVENT) &&
1303                     (block->notify_id == event))
1304                 {
1305                         found_it = true;
1306                         break;
1307                 }
1308         }
1309
1310         if (!found_it)
1311                 return;
1312
1313         /* If a driver is bound, then notify the driver. */
1314         if (wblock->dev.dev.driver) {
1315                 struct wmi_driver *driver;
1316                 struct acpi_object_list input;
1317                 union acpi_object params[1];
1318                 struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL };
1319                 acpi_status status;
1320
1321                 driver = container_of(wblock->dev.dev.driver,
1322                                       struct wmi_driver, driver);
1323
1324                 input.count = 1;
1325                 input.pointer = params;
1326                 params[0].type = ACPI_TYPE_INTEGER;
1327                 params[0].integer.value = event;
1328
1329                 status = acpi_evaluate_object(wblock->acpi_device->handle,
1330                                               "_WED", &input, &evdata);
1331                 if (ACPI_FAILURE(status)) {
1332                         dev_warn(&wblock->dev.dev,
1333                                  "failed to get event data\n");
1334                         return;
1335                 }
1336
1337                 if (driver->notify)
1338                         driver->notify(&wblock->dev,
1339                                        (union acpi_object *)evdata.pointer);
1340
1341                 kfree(evdata.pointer);
1342         } else if (wblock->handler) {
1343                 /* Legacy handler */
1344                 wblock->handler(event, wblock->handler_data);
1345         }
1346
1347         if (debug_event) {
1348                 pr_info("DEBUG Event GUID: %pUL\n",
1349                         wblock->gblock.guid);
1350         }
1351
1352         acpi_bus_generate_netlink_event(
1353                 wblock->acpi_device->pnp.device_class,
1354                 dev_name(&wblock->dev.dev),
1355                 event, 0);
1356
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_DEVICE_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_destroy(&wmi_bus_class, MKDEV(0, 0));
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_DEVICE_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_destroy(&wmi_bus_class, MKDEV(0, 0));
1423
1424 err_remove_notify_handler:
1425         acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_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);