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/device.h>
  21 #include <linux/init.h>
  22 #include <linux/kernel.h>
  23 #include <linux/list.h>
  24 #include <linux/miscdevice.h>
  25 #include <linux/module.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/slab.h>
  28 #include <linux/types.h>
  29 #include <linux/uaccess.h>
  30 #include <linux/uuid.h>
  31 #include <linux/wmi.h>
  32 #include <linux/fs.h>
  33 #include <uapi/linux/wmi.h>
  34
  35 MODULE_AUTHOR("Carlos Corbacho");
  36 MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
  37 MODULE_LICENSE("GPL");
  38
  39 static LIST_HEAD(wmi_block_list);
  40
  41 struct guid_block {
  42         char guid[16];
  43         union {
  44                 char object_id[2];
  45                 struct {
  46                         unsigned char notify_id;
  47                         unsigned char reserved;
  48                 };
  49         };
  50         u8 instance_count;
  51         u8 flags;
  52 };
  53
  54 enum {  /* wmi_block flags */
  55         WMI_READ_TAKES_NO_ARGS,
  56         WMI_PROBED,
  57 };
  58
  59 struct wmi_block {
  60         struct wmi_device dev;
  61         struct list_head list;
  62         struct guid_block gblock;
  63         struct miscdevice char_dev;
  64         struct mutex char_mutex;
  65         struct acpi_device *acpi_device;
  66         wmi_notify_handler handler;
  67         void *handler_data;
  68         u64 req_buf_size;
  69         unsigned long flags;
  70 };
  71
  72
  73 /*
  74  * If the GUID data block is marked as expensive, we must enable and
  75  * explicitily disable data collection.
  76  */
  77 #define ACPI_WMI_EXPENSIVE   0x1
  78 #define ACPI_WMI_METHOD      0x2        /* GUID is a method */
  79 #define ACPI_WMI_STRING      0x4        /* GUID takes & returns a string */
  80 #define ACPI_WMI_EVENT       0x8        /* GUID is an event */
  81
  82 static bool debug_event;
  83 module_param(debug_event, bool, 0444);
  84 MODULE_PARM_DESC(debug_event,
  85                  "Log WMI Events [0/1]");
  86
  87 static bool debug_dump_wdg;
  88 module_param(debug_dump_wdg, bool, 0444);
  89 MODULE_PARM_DESC(debug_dump_wdg,
  90                  "Dump available WMI interfaces [0/1]");
  91
  92 static int acpi_wmi_remove(struct platform_device *device);
  93 static int acpi_wmi_probe(struct platform_device *device);
  94
  95 static const struct acpi_device_id wmi_device_ids[] = {
  96         {"PNP0C14", 0},
  97         {"pnp0c14", 0},
  98         {"", 0},
  99 };
 100 MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
 101
 102 static struct platform_driver acpi_wmi_driver = {
 103         .driver = {
 104                 .name = "acpi-wmi",
 105                 .acpi_match_table = wmi_device_ids,
 106         },
 107         .probe = acpi_wmi_probe,
 108         .remove = acpi_wmi_remove,
 109 };
 110
 111 /*
 112  * GUID parsing functions
 113  */
 114
 115 static bool find_guid(const char *guid_string, struct wmi_block **out)
 116 {
 117         guid_t guid_input;
 118         struct wmi_block *wblock;
 119         struct guid_block *block;
 120
 121         if (guid_parse(guid_string, &guid_input))
 122                 return false;
 123
 124         list_for_each_entry(wblock, &wmi_block_list, list) {
 125                 block = &wblock->gblock;
 126
 127                 if (memcmp(block->guid, &guid_input, 16) == 0) {
 128                         if (out)
 129                                 *out = wblock;
 130                         return true;
 131                 }
 132         }
 133         return false;
 134 }
 135
 136 static const void *find_guid_context(struct wmi_block *wblock,
 137                                       struct wmi_driver *wdriver)
 138 {
 139         const struct wmi_device_id *id;
 140         guid_t guid_input;
 141
 142         if (wblock == NULL || wdriver == NULL)
 143                 return NULL;
 144         if (wdriver->id_table == NULL)
 145                 return NULL;
 146
 147         id = wdriver->id_table;
 148         while (*id->guid_string) {
 149                 if (guid_parse(id->guid_string, &guid_input))
 150                         continue;
 151                 if (!memcmp(wblock->gblock.guid, &guid_input, 16))
 152                         return id->context;
 153                 id++;
 154         }
 155         return NULL;
 156 }
 157
 158 static int get_subobj_info(acpi_handle handle, const char *pathname,
 159                            struct acpi_device_info **info)
 160 {
 161         struct acpi_device_info *dummy_info, **info_ptr;
 162         acpi_handle subobj_handle;
 163         acpi_status status;
 164
 165         status = acpi_get_handle(handle, (char *)pathname, &subobj_handle);
 166         if (status == AE_NOT_FOUND)
 167                 return -ENOENT;
 168         else if (ACPI_FAILURE(status))
 169                 return -EIO;
 170
 171         info_ptr = info ? info : &dummy_info;
 172         status = acpi_get_object_info(subobj_handle, info_ptr);
 173         if (ACPI_FAILURE(status))
 174                 return -EIO;
 175
 176         if (!info)
 177                 kfree(dummy_info);
 178
 179         return 0;
 180 }
 181
 182 static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable)
 183 {
 184         struct guid_block *block = NULL;
 185         char method[5];
 186         acpi_status status;
 187         acpi_handle handle;
 188
 189         block = &wblock->gblock;
 190         handle = wblock->acpi_device->handle;
 191
 192         snprintf(method, 5, "WE%02X", block->notify_id);
 193         status = acpi_execute_simple_method(handle, method, enable);
 194
 195         if (status != AE_OK && status != AE_NOT_FOUND)
 196                 return status;
 197         else
 198                 return AE_OK;
 199 }
 200
 201 /*
 202  * Exported WMI functions
 203  */
 204
 205 /**
 206  * set_required_buffer_size - Sets the buffer size needed for performing IOCTL
 207  * @wdev: A wmi bus device from a driver
 208  * @length: Required buffer size
 209  *
 210  * Allocates memory needed for buffer, stores the buffer size in that memory
 211  */
 212 int set_required_buffer_size(struct wmi_device *wdev, u64 length)
 213 {
 214         struct wmi_block *wblock;
 215
 216         wblock = container_of(wdev, struct wmi_block, dev);
 217         wblock->req_buf_size = length;
 218
 219         return 0;
 220 }
 221 EXPORT_SYMBOL_GPL(set_required_buffer_size);
 222
 223 /**
 224  * wmi_evaluate_method - Evaluate a WMI method
 225  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 226  * @instance: Instance index
 227  * @method_id: Method ID to call
 228  * @in: Buffer containing input for the method call
 229  * @out: Empty buffer to return the method results
 230  *
 231  * Call an ACPI-WMI method
 232  */
 233 acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
 234 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
 235 {
 236         struct wmi_block *wblock = NULL;
 237
 238         if (!find_guid(guid_string, &wblock))
 239                 return AE_ERROR;
 240         return wmidev_evaluate_method(&wblock->dev, instance, method_id,
 241                                       in, out);
 242 }
 243 EXPORT_SYMBOL_GPL(wmi_evaluate_method);
 244
 245 /**
 246  * wmidev_evaluate_method - Evaluate a WMI method
 247  * @wdev: A wmi bus device from a driver
 248  * @instance: Instance index
 249  * @method_id: Method ID to call
 250  * @in: Buffer containing input for the method call
 251  * @out: Empty buffer to return the method results
 252  *
 253  * Call an ACPI-WMI method
 254  */
 255 acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance,
 256         u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
 257 {
 258         struct guid_block *block = NULL;
 259         struct wmi_block *wblock = NULL;
 260         acpi_handle handle;
 261         acpi_status status;
 262         struct acpi_object_list input;
 263         union acpi_object params[3];
 264         char method[5] = "WM";
 265
 266         wblock = container_of(wdev, struct wmi_block, dev);
 267         block = &wblock->gblock;
 268         handle = wblock->acpi_device->handle;
 269
 270         if (!(block->flags & ACPI_WMI_METHOD))
 271                 return AE_BAD_DATA;
 272
 273         if (block->instance_count <= instance)
 274                 return AE_BAD_PARAMETER;
 275
 276         input.count = 2;
 277         input.pointer = params;
 278         params[0].type = ACPI_TYPE_INTEGER;
 279         params[0].integer.value = instance;
 280         params[1].type = ACPI_TYPE_INTEGER;
 281         params[1].integer.value = method_id;
 282
 283         if (in) {
 284                 input.count = 3;
 285
 286                 if (block->flags & ACPI_WMI_STRING) {
 287                         params[2].type = ACPI_TYPE_STRING;
 288                 } else {
 289                         params[2].type = ACPI_TYPE_BUFFER;
 290                 }
 291                 params[2].buffer.length = in->length;
 292                 params[2].buffer.pointer = in->pointer;
 293         }
 294
 295         strncat(method, block->object_id, 2);
 296
 297         status = acpi_evaluate_object(handle, method, &input, out);
 298
 299         return status;
 300 }
 301 EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
 302
 303 static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
 304                                  struct acpi_buffer *out)
 305 {
 306         struct guid_block *block = NULL;
 307         acpi_handle handle;
 308         acpi_status status, wc_status = AE_ERROR;
 309         struct acpi_object_list input;
 310         union acpi_object wq_params[1];
 311         char method[5];
 312         char wc_method[5] = "WC";
 313
 314         if (!out)
 315                 return AE_BAD_PARAMETER;
 316
 317         block = &wblock->gblock;
 318         handle = wblock->acpi_device->handle;
 319
 320         if (block->instance_count <= instance)
 321                 return AE_BAD_PARAMETER;
 322
 323         /* Check GUID is a data block */
 324         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 325                 return AE_ERROR;
 326
 327         input.count = 1;
 328         input.pointer = wq_params;
 329         wq_params[0].type = ACPI_TYPE_INTEGER;
 330         wq_params[0].integer.value = instance;
 331
 332         if (instance == 0 && test_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags))
 333                 input.count = 0;
 334
 335         /*
 336          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
 337          * enable collection.
 338          */
 339         if (block->flags & ACPI_WMI_EXPENSIVE) {
 340                 strncat(wc_method, block->object_id, 2);
 341
 342                 /*
 343                  * Some GUIDs break the specification by declaring themselves
 344                  * expensive, but have no corresponding WCxx method. So we
 345                  * should not fail if this happens.
 346                  */
 347                 wc_status = acpi_execute_simple_method(handle, wc_method, 1);
 348         }
 349
 350         strcpy(method, "WQ");
 351         strncat(method, block->object_id, 2);
 352
 353         status = acpi_evaluate_object(handle, method, &input, out);
 354
 355         /*
 356          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
 357          * the WQxx method failed - we should disable collection anyway.
 358          */
 359         if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
 360                 /*
 361                  * Ignore whether this WCxx call succeeds or not since
 362                  * the previously executed WQxx method call might have
 363                  * succeeded, and returning the failing status code
 364                  * of this call would throw away the result of the WQxx
 365                  * call, potentially leaking memory.
 366                  */
 367                 acpi_execute_simple_method(handle, wc_method, 0);
 368         }
 369
 370         return status;
 371 }
 372
 373 /**
 374  * wmi_query_block - Return contents of a WMI block (deprecated)
 375  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 376  * @instance: Instance index
 377  * @out: Empty buffer to return the contents of the data block to
 378  *
 379  * Return the contents of an ACPI-WMI data block to a buffer
 380  */
 381 acpi_status wmi_query_block(const char *guid_string, u8 instance,
 382                             struct acpi_buffer *out)
 383 {
 384         struct wmi_block *wblock;
 385
 386         if (!guid_string)
 387                 return AE_BAD_PARAMETER;
 388
 389         if (!find_guid(guid_string, &wblock))
 390                 return AE_ERROR;
 391
 392         return __query_block(wblock, instance, out);
 393 }
 394 EXPORT_SYMBOL_GPL(wmi_query_block);
 395
 396 union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
 397 {
 398         struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
 399         struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
 400
 401         if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
 402                 return NULL;
 403
 404         return (union acpi_object *)out.pointer;
 405 }
 406 EXPORT_SYMBOL_GPL(wmidev_block_query);
 407
 408 /**
 409  * wmi_set_block - Write to a WMI block
 410  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 411  * @instance: Instance index
 412  * @in: Buffer containing new values for the data block
 413  *
 414  * Write the contents of the input buffer to an ACPI-WMI data block
 415  */
 416 acpi_status wmi_set_block(const char *guid_string, u8 instance,
 417                           const struct acpi_buffer *in)
 418 {
 419         struct guid_block *block = NULL;
 420         struct wmi_block *wblock = NULL;
 421         acpi_handle handle;
 422         struct acpi_object_list input;
 423         union acpi_object params[2];
 424         char method[5] = "WS";
 425
 426         if (!guid_string || !in)
 427                 return AE_BAD_DATA;
 428
 429         if (!find_guid(guid_string, &wblock))
 430                 return AE_ERROR;
 431
 432         block = &wblock->gblock;
 433         handle = wblock->acpi_device->handle;
 434
 435         if (block->instance_count <= instance)
 436                 return AE_BAD_PARAMETER;
 437
 438         /* Check GUID is a data block */
 439         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 440                 return AE_ERROR;
 441
 442         input.count = 2;
 443         input.pointer = params;
 444         params[0].type = ACPI_TYPE_INTEGER;
 445         params[0].integer.value = instance;
 446
 447         if (block->flags & ACPI_WMI_STRING) {
 448                 params[1].type = ACPI_TYPE_STRING;
 449         } else {
 450                 params[1].type = ACPI_TYPE_BUFFER;
 451         }
 452         params[1].buffer.length = in->length;
 453         params[1].buffer.pointer = in->pointer;
 454
 455         strncat(method, block->object_id, 2);
 456
 457         return acpi_evaluate_object(handle, method, &input, NULL);
 458 }
 459 EXPORT_SYMBOL_GPL(wmi_set_block);
 460
 461 static void wmi_dump_wdg(const struct guid_block *g)
 462 {
 463         pr_info("%pUL:\n", g->guid);
 464         if (g->flags & ACPI_WMI_EVENT)
 465                 pr_info("\tnotify_id: 0x%02X\n", g->notify_id);
 466         else
 467                 pr_info("\tobject_id: %2pE\n", g->object_id);
 468         pr_info("\tinstance_count: %d\n", g->instance_count);
 469         pr_info("\tflags: %#x", g->flags);
 470         if (g->flags) {
 471                 if (g->flags & ACPI_WMI_EXPENSIVE)
 472                         pr_cont(" ACPI_WMI_EXPENSIVE");
 473                 if (g->flags & ACPI_WMI_METHOD)
 474                         pr_cont(" ACPI_WMI_METHOD");
 475                 if (g->flags & ACPI_WMI_STRING)
 476                         pr_cont(" ACPI_WMI_STRING");
 477                 if (g->flags & ACPI_WMI_EVENT)
 478                         pr_cont(" ACPI_WMI_EVENT");
 479         }
 480         pr_cont("\n");
 481
 482 }
 483
 484 static void wmi_notify_debug(u32 value, void *context)
 485 {
 486         struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
 487         union acpi_object *obj;
 488         acpi_status status;
 489
 490         status = wmi_get_event_data(value, &response);
 491         if (status != AE_OK) {
 492                 pr_info("bad event status 0x%x\n", status);
 493                 return;
 494         }
 495
 496         obj = (union acpi_object *)response.pointer;
 497
 498         if (!obj)
 499                 return;
 500
 501         pr_info("DEBUG Event ");
 502         switch(obj->type) {
 503         case ACPI_TYPE_BUFFER:
 504                 pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
 505                 break;
 506         case ACPI_TYPE_STRING:
 507                 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
 508                 break;
 509         case ACPI_TYPE_INTEGER:
 510                 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
 511                 break;
 512         case ACPI_TYPE_PACKAGE:
 513                 pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
 514                 break;
 515         default:
 516                 pr_cont("object type 0x%X\n", obj->type);
 517         }
 518         kfree(obj);
 519 }
 520
 521 /**
 522  * wmi_install_notify_handler - Register handler for WMI events
 523  * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 524  * @handler: Function to handle notifications
 525  * @data: Data to be returned to handler when event is fired
 526  *
 527  * Register a handler for events sent to the ACPI-WMI mapper device.
 528  */
 529 acpi_status wmi_install_notify_handler(const char *guid,
 530 wmi_notify_handler handler, void *data)
 531 {
 532         struct wmi_block *block;
 533         acpi_status status = AE_NOT_EXIST;
 534         guid_t guid_input;
 535
 536         if (!guid || !handler)
 537                 return AE_BAD_PARAMETER;
 538
 539         if (guid_parse(guid, &guid_input))
 540                 return AE_BAD_PARAMETER;
 541
 542         list_for_each_entry(block, &wmi_block_list, list) {
 543                 acpi_status wmi_status;
 544
 545                 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
 546                         if (block->handler &&
 547                             block->handler != wmi_notify_debug)
 548                                 return AE_ALREADY_ACQUIRED;
 549
 550                         block->handler = handler;
 551                         block->handler_data = data;
 552
 553                         wmi_status = wmi_method_enable(block, 1);
 554                         if ((wmi_status != AE_OK) ||
 555                             ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
 556                                 status = wmi_status;
 557                 }
 558         }
 559
 560         return status;
 561 }
 562 EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
 563
 564 /**
 565  * wmi_uninstall_notify_handler - Unregister handler for WMI events
 566  * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 567  *
 568  * Unregister handler for events sent to the ACPI-WMI mapper device.
 569  */
 570 acpi_status wmi_remove_notify_handler(const char *guid)
 571 {
 572         struct wmi_block *block;
 573         acpi_status status = AE_NOT_EXIST;
 574         guid_t guid_input;
 575
 576         if (!guid)
 577                 return AE_BAD_PARAMETER;
 578
 579         if (guid_parse(guid, &guid_input))
 580                 return AE_BAD_PARAMETER;
 581
 582         list_for_each_entry(block, &wmi_block_list, list) {
 583                 acpi_status wmi_status;
 584
 585                 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
 586                         if (!block->handler ||
 587                             block->handler == wmi_notify_debug)
 588                                 return AE_NULL_ENTRY;
 589
 590                         if (debug_event) {
 591                                 block->handler = wmi_notify_debug;
 592                                 status = AE_OK;
 593                         } else {
 594                                 wmi_status = wmi_method_enable(block, 0);
 595                                 block->handler = NULL;
 596                                 block->handler_data = NULL;
 597                                 if ((wmi_status != AE_OK) ||
 598                                     ((wmi_status == AE_OK) &&
 599                                      (status == AE_NOT_EXIST)))
 600                                         status = wmi_status;
 601                         }
 602                 }
 603         }
 604
 605         return status;
 606 }
 607 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
 608
 609 /**
 610  * wmi_get_event_data - Get WMI data associated with an event
 611  *
 612  * @event: Event to find
 613  * @out: Buffer to hold event data. out->pointer should be freed with kfree()
 614  *
 615  * Returns extra data associated with an event in WMI.
 616  */
 617 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
 618 {
 619         struct acpi_object_list input;
 620         union acpi_object params[1];
 621         struct guid_block *gblock;
 622         struct wmi_block *wblock;
 623
 624         input.count = 1;
 625         input.pointer = params;
 626         params[0].type = ACPI_TYPE_INTEGER;
 627         params[0].integer.value = event;
 628
 629         list_for_each_entry(wblock, &wmi_block_list, list) {
 630                 gblock = &wblock->gblock;
 631
 632                 if ((gblock->flags & ACPI_WMI_EVENT) &&
 633                         (gblock->notify_id == event))
 634                         return acpi_evaluate_object(wblock->acpi_device->handle,
 635                                 "_WED", &input, out);
 636         }
 637
 638         return AE_NOT_FOUND;
 639 }
 640 EXPORT_SYMBOL_GPL(wmi_get_event_data);
 641
 642 /**
 643  * wmi_has_guid - Check if a GUID is available
 644  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 645  *
 646  * Check if a given GUID is defined by _WDG
 647  */
 648 bool wmi_has_guid(const char *guid_string)
 649 {
 650         return find_guid(guid_string, NULL);
 651 }
 652 EXPORT_SYMBOL_GPL(wmi_has_guid);
 653
 654 /**
 655  * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID
 656  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 657  *
 658  * Find the _UID of ACPI device associated with this WMI GUID.
 659  *
 660  * Return: The ACPI _UID field value or NULL if the WMI GUID was not found
 661  */
 662 char *wmi_get_acpi_device_uid(const char *guid_string)
 663 {
 664         struct wmi_block *wblock = NULL;
 665
 666         if (!find_guid(guid_string, &wblock))
 667                 return NULL;
 668
 669         return acpi_device_uid(wblock->acpi_device);
 670 }
 671 EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
 672
 673 static struct wmi_block *dev_to_wblock(struct device *dev)
 674 {
 675         return container_of(dev, struct wmi_block, dev.dev);
 676 }
 677
 678 static struct wmi_device *dev_to_wdev(struct device *dev)
 679 {
 680         return container_of(dev, struct wmi_device, dev);
 681 }
 682
 683 static inline struct wmi_driver *drv_to_wdrv(struct device_driver *drv)
 684 {
 685         return container_of(drv, struct wmi_driver, driver);
 686 }
 687
 688 /*
 689  * sysfs interface
 690  */
 691 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 692                              char *buf)
 693 {
 694         struct wmi_block *wblock = dev_to_wblock(dev);
 695
 696         return sprintf(buf, "wmi:%pUL\n", wblock->gblock.guid);
 697 }
 698 static DEVICE_ATTR_RO(modalias);
 699
 700 static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
 701                          char *buf)
 702 {
 703         struct wmi_block *wblock = dev_to_wblock(dev);
 704
 705         return sprintf(buf, "%pUL\n", wblock->gblock.guid);
 706 }
 707 static DEVICE_ATTR_RO(guid);
 708
 709 static ssize_t instance_count_show(struct device *dev,
 710                                    struct device_attribute *attr, char *buf)
 711 {
 712         struct wmi_block *wblock = dev_to_wblock(dev);
 713
 714         return sprintf(buf, "%d\n", (int)wblock->gblock.instance_count);
 715 }
 716 static DEVICE_ATTR_RO(instance_count);
 717
 718 static ssize_t expensive_show(struct device *dev,
 719                               struct device_attribute *attr, char *buf)
 720 {
 721         struct wmi_block *wblock = dev_to_wblock(dev);
 722
 723         return sprintf(buf, "%d\n",
 724                        (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
 725 }
 726 static DEVICE_ATTR_RO(expensive);
 727
 728 static struct attribute *wmi_attrs[] = {
 729         &dev_attr_modalias.attr,
 730         &dev_attr_guid.attr,
 731         &dev_attr_instance_count.attr,
 732         &dev_attr_expensive.attr,
 733         NULL,
 734 };
 735 ATTRIBUTE_GROUPS(wmi);
 736
 737 static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
 738                               char *buf)
 739 {
 740         struct wmi_block *wblock = dev_to_wblock(dev);
 741
 742         return sprintf(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
 743 }
 744 static DEVICE_ATTR_RO(notify_id);
 745
 746 static struct attribute *wmi_event_attrs[] = {
 747         &dev_attr_notify_id.attr,
 748         NULL,
 749 };
 750 ATTRIBUTE_GROUPS(wmi_event);
 751
 752 static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
 753                               char *buf)
 754 {
 755         struct wmi_block *wblock = dev_to_wblock(dev);
 756
 757         return sprintf(buf, "%c%c\n", wblock->gblock.object_id[0],
 758                        wblock->gblock.object_id[1]);
 759 }
 760 static DEVICE_ATTR_RO(object_id);
 761
 762 static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
 763                             char *buf)
 764 {
 765         struct wmi_device *wdev = dev_to_wdev(dev);
 766
 767         return sprintf(buf, "%d\n", (int)wdev->setable);
 768 }
 769 static DEVICE_ATTR_RO(setable);
 770
 771 static struct attribute *wmi_data_attrs[] = {
 772         &dev_attr_object_id.attr,
 773         &dev_attr_setable.attr,
 774         NULL,
 775 };
 776 ATTRIBUTE_GROUPS(wmi_data);
 777
 778 static struct attribute *wmi_method_attrs[] = {
 779         &dev_attr_object_id.attr,
 780         NULL,
 781 };
 782 ATTRIBUTE_GROUPS(wmi_method);
 783
 784 static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 785 {
 786         struct wmi_block *wblock = dev_to_wblock(dev);
 787
 788         if (add_uevent_var(env, "MODALIAS=wmi:%pUL", wblock->gblock.guid))
 789                 return -ENOMEM;
 790
 791         if (add_uevent_var(env, "WMI_GUID=%pUL", wblock->gblock.guid))
 792                 return -ENOMEM;
 793
 794         return 0;
 795 }
 796
 797 static void wmi_dev_release(struct device *dev)
 798 {
 799         struct wmi_block *wblock = dev_to_wblock(dev);
 800
 801         kfree(wblock);
 802 }
 803
 804 static int wmi_dev_match(struct device *dev, struct device_driver *driver)
 805 {
 806         struct wmi_driver *wmi_driver = drv_to_wdrv(driver);
 807         struct wmi_block *wblock = dev_to_wblock(dev);
 808         const struct wmi_device_id *id = wmi_driver->id_table;
 809
 810         if (id == NULL)
 811                 return 0;
 812
 813         while (*id->guid_string) {
 814                 guid_t driver_guid;
 815
 816                 if (WARN_ON(guid_parse(id->guid_string, &driver_guid)))
 817                         continue;
 818                 if (!memcmp(&driver_guid, wblock->gblock.guid, 16))
 819                         return 1;
 820
 821                 id++;
 822         }
 823
 824         return 0;
 825 }
 826 static int wmi_char_open(struct inode *inode, struct file *filp)
 827 {
 828         const char *driver_name = filp->f_path.dentry->d_iname;
 829         struct wmi_block *wblock = NULL;
 830         struct wmi_block *next = NULL;
 831
 832         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
 833                 if (!wblock->dev.dev.driver)
 834                         continue;
 835                 if (strcmp(driver_name, wblock->dev.dev.driver->name) == 0) {
 836                         filp->private_data = wblock;
 837                         break;
 838                 }
 839         }
 840
 841         if (!filp->private_data)
 842                 return -ENODEV;
 843
 844         return nonseekable_open(inode, filp);
 845 }
 846
 847 static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
 848         size_t length, loff_t *offset)
 849 {
 850         struct wmi_block *wblock = filp->private_data;
 851
 852         return simple_read_from_buffer(buffer, length, offset,
 853                                        &wblock->req_buf_size,
 854                                        sizeof(wblock->req_buf_size));
 855 }
 856
 857 static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 858 {
 859         struct wmi_ioctl_buffer __user *input =
 860                 (struct wmi_ioctl_buffer __user *) arg;
 861         struct wmi_block *wblock = filp->private_data;
 862         struct wmi_ioctl_buffer *buf = NULL;
 863         struct wmi_driver *wdriver = NULL;
 864         int ret;
 865
 866         if (_IOC_TYPE(cmd) != WMI_IOC)
 867                 return -ENOTTY;
 868
 869         /* make sure we're not calling a higher instance than exists*/
 870         if (_IOC_NR(cmd) >= wblock->gblock.instance_count)
 871                 return -EINVAL;
 872
 873         mutex_lock(&wblock->char_mutex);
 874         buf = wblock->handler_data;
 875         if (get_user(buf->length, &input->length)) {
 876                 dev_dbg(&wblock->dev.dev, "Read length from user failed\n");
 877                 ret = -EFAULT;
 878                 goto out_ioctl;
 879         }
 880         /* if it's too small, abort */
 881         if (buf->length < wblock->req_buf_size) {
 882                 dev_err(&wblock->dev.dev,
 883                         "Buffer %lld too small, need at least %lld\n",
 884                         buf->length, wblock->req_buf_size);
 885                 ret = -EINVAL;
 886                 goto out_ioctl;
 887         }
 888         /* if it's too big, warn, driver will only use what is needed */
 889         if (buf->length > wblock->req_buf_size)
 890                 dev_warn(&wblock->dev.dev,
 891                         "Buffer %lld is bigger than required %lld\n",
 892                         buf->length, wblock->req_buf_size);
 893
 894         /* copy the structure from userspace */
 895         if (copy_from_user(buf, input, wblock->req_buf_size)) {
 896                 dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n",
 897                         wblock->req_buf_size);
 898                 ret = -EFAULT;
 899                 goto out_ioctl;
 900         }
 901
 902         /* let the driver do any filtering and do the call */
 903         wdriver = drv_to_wdrv(wblock->dev.dev.driver);
 904         if (!try_module_get(wdriver->driver.owner)) {
 905                 ret = -EBUSY;
 906                 goto out_ioctl;
 907         }
 908         ret = wdriver->filter_callback(&wblock->dev, cmd, buf);
 909         module_put(wdriver->driver.owner);
 910         if (ret)
 911                 goto out_ioctl;
 912
 913         /* return the result (only up to our internal buffer size) */
 914         if (copy_to_user(input, buf, wblock->req_buf_size)) {
 915                 dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n",
 916                         wblock->req_buf_size);
 917                 ret = -EFAULT;
 918         }
 919
 920 out_ioctl:
 921         mutex_unlock(&wblock->char_mutex);
 922         return ret;
 923 }
 924
 925 static const struct file_operations wmi_fops = {
 926         .owner          = THIS_MODULE,
 927         .read           = wmi_char_read,
 928         .open           = wmi_char_open,
 929         .unlocked_ioctl = wmi_ioctl,
 930         .compat_ioctl   = compat_ptr_ioctl,
 931 };
 932
 933 static int wmi_dev_probe(struct device *dev)
 934 {
 935         struct wmi_block *wblock = dev_to_wblock(dev);
 936         struct wmi_driver *wdriver = drv_to_wdrv(dev->driver);
 937         int ret = 0;
 938         char *buf;
 939
 940         if (ACPI_FAILURE(wmi_method_enable(wblock, 1)))
 941                 dev_warn(dev, "failed to enable device -- probing anyway\n");
 942
 943         if (wdriver->probe) {
 944                 ret = wdriver->probe(dev_to_wdev(dev),
 945                                 find_guid_context(wblock, wdriver));
 946                 if (ret != 0)
 947                         goto probe_failure;
 948         }
 949
 950         /* driver wants a character device made */
 951         if (wdriver->filter_callback) {
 952                 /* check that required buffer size declared by driver or MOF */
 953                 if (!wblock->req_buf_size) {
 954                         dev_err(&wblock->dev.dev,
 955                                 "Required buffer size not set\n");
 956                         ret = -EINVAL;
 957                         goto probe_failure;
 958                 }
 959
 960                 wblock->handler_data = kmalloc(wblock->req_buf_size,
 961                                                GFP_KERNEL);
 962                 if (!wblock->handler_data) {
 963                         ret = -ENOMEM;
 964                         goto probe_failure;
 965                 }
 966
 967                 buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name);
 968                 if (!buf) {
 969                         ret = -ENOMEM;
 970                         goto probe_string_failure;
 971                 }
 972                 wblock->char_dev.minor = MISC_DYNAMIC_MINOR;
 973                 wblock->char_dev.name = buf;
 974                 wblock->char_dev.fops = &wmi_fops;
 975                 wblock->char_dev.mode = 0444;
 976                 ret = misc_register(&wblock->char_dev);
 977                 if (ret) {
 978                         dev_warn(dev, "failed to register char dev: %d\n", ret);
 979                         ret = -ENOMEM;
 980                         goto probe_misc_failure;
 981                 }
 982         }
 983
 984         set_bit(WMI_PROBED, &wblock->flags);
 985         return 0;
 986
 987 probe_misc_failure:
 988         kfree(buf);
 989 probe_string_failure:
 990         kfree(wblock->handler_data);
 991 probe_failure:
 992         if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
 993                 dev_warn(dev, "failed to disable device\n");
 994         return ret;
 995 }
 996
 997 static void wmi_dev_remove(struct device *dev)
 998 {
 999         struct wmi_block *wblock = dev_to_wblock(dev);
1000         struct wmi_driver *wdriver = drv_to_wdrv(dev->driver);
1001
1002         clear_bit(WMI_PROBED, &wblock->flags);
1003
1004         if (wdriver->filter_callback) {
1005                 misc_deregister(&wblock->char_dev);
1006                 kfree(wblock->char_dev.name);
1007                 kfree(wblock->handler_data);
1008         }
1009
1010         if (wdriver->remove)
1011                 wdriver->remove(dev_to_wdev(dev));
1012
1013         if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
1014                 dev_warn(dev, "failed to disable device\n");
1015 }
1016
1017 static struct class wmi_bus_class = {
1018         .name = "wmi_bus",
1019 };
1020
1021 static struct bus_type wmi_bus_type = {
1022         .name = "wmi",
1023         .dev_groups = wmi_groups,
1024         .match = wmi_dev_match,
1025         .uevent = wmi_dev_uevent,
1026         .probe = wmi_dev_probe,
1027         .remove = wmi_dev_remove,
1028 };
1029
1030 static const struct device_type wmi_type_event = {
1031         .name = "event",
1032         .groups = wmi_event_groups,
1033         .release = wmi_dev_release,
1034 };
1035
1036 static const struct device_type wmi_type_method = {
1037         .name = "method",
1038         .groups = wmi_method_groups,
1039         .release = wmi_dev_release,
1040 };
1041
1042 static const struct device_type wmi_type_data = {
1043         .name = "data",
1044         .groups = wmi_data_groups,
1045         .release = wmi_dev_release,
1046 };
1047
1048 static int wmi_create_device(struct device *wmi_bus_dev,
1049                              const struct guid_block *gblock,
1050                              struct wmi_block *wblock,
1051                              struct acpi_device *device)
1052 {
1053         struct acpi_device_info *info;
1054         char method[5];
1055         int result;
1056
1057         if (gblock->flags & ACPI_WMI_EVENT) {
1058                 wblock->dev.dev.type = &wmi_type_event;
1059                 goto out_init;
1060         }
1061
1062         if (gblock->flags & ACPI_WMI_METHOD) {
1063                 wblock->dev.dev.type = &wmi_type_method;
1064                 mutex_init(&wblock->char_mutex);
1065                 goto out_init;
1066         }
1067
1068         /*
1069          * Data Block Query Control Method (WQxx by convention) is
1070          * required per the WMI documentation. If it is not present,
1071          * we ignore this data block.
1072          */
1073         strcpy(method, "WQ");
1074         strncat(method, wblock->gblock.object_id, 2);
1075         result = get_subobj_info(device->handle, method, &info);
1076
1077         if (result) {
1078                 dev_warn(wmi_bus_dev,
1079                          "%s data block query control method not found\n",
1080                          method);
1081                 return result;
1082         }
1083
1084         wblock->dev.dev.type = &wmi_type_data;
1085
1086         /*
1087          * The Microsoft documentation specifically states:
1088          *
1089          *   Data blocks registered with only a single instance
1090          *   can ignore the parameter.
1091          *
1092          * ACPICA will get mad at us if we call the method with the wrong number
1093          * of arguments, so check what our method expects.  (On some Dell
1094          * laptops, WQxx may not be a method at all.)
1095          */
1096         if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1097                 set_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags);
1098
1099         kfree(info);
1100
1101         strcpy(method, "WS");
1102         strncat(method, wblock->gblock.object_id, 2);
1103         result = get_subobj_info(device->handle, method, NULL);
1104
1105         if (result == 0)
1106                 wblock->dev.setable = true;
1107
1108  out_init:
1109         wblock->dev.dev.bus = &wmi_bus_type;
1110         wblock->dev.dev.parent = wmi_bus_dev;
1111
1112         dev_set_name(&wblock->dev.dev, "%pUL", gblock->guid);
1113
1114         device_initialize(&wblock->dev.dev);
1115
1116         return 0;
1117 }
1118
1119 static void wmi_free_devices(struct acpi_device *device)
1120 {
1121         struct wmi_block *wblock, *next;
1122
1123         /* Delete devices for all the GUIDs */
1124         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1125                 if (wblock->acpi_device == device) {
1126                         list_del(&wblock->list);
1127                         device_unregister(&wblock->dev.dev);
1128                 }
1129         }
1130 }
1131
1132 static bool guid_already_parsed(struct acpi_device *device, const u8 *guid)
1133 {
1134         struct wmi_block *wblock;
1135
1136         list_for_each_entry(wblock, &wmi_block_list, list) {
1137                 if (memcmp(wblock->gblock.guid, guid, 16) == 0) {
1138                         /*
1139                          * Because we historically didn't track the relationship
1140                          * between GUIDs and ACPI nodes, we don't know whether
1141                          * we need to suppress GUIDs that are unique on a
1142                          * given node but duplicated across nodes.
1143                          */
1144                         dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
1145                                  guid, dev_name(&wblock->acpi_device->dev));
1146                         return true;
1147                 }
1148         }
1149
1150         return false;
1151 }
1152
1153 /*
1154  * Parse the _WDG method for the GUID data blocks
1155  */
1156 static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
1157 {
1158         struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1159         const struct guid_block *gblock;
1160         struct wmi_block *wblock, *next;
1161         union acpi_object *obj;
1162         acpi_status status;
1163         int retval = 0;
1164         u32 i, total;
1165
1166         status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1167         if (ACPI_FAILURE(status))
1168                 return -ENXIO;
1169
1170         obj = (union acpi_object *) out.pointer;
1171         if (!obj)
1172                 return -ENXIO;
1173
1174         if (obj->type != ACPI_TYPE_BUFFER) {
1175                 retval = -ENXIO;
1176                 goto out_free_pointer;
1177         }
1178
1179         gblock = (const struct guid_block *)obj->buffer.pointer;
1180         total = obj->buffer.length / sizeof(struct guid_block);
1181
1182         for (i = 0; i < total; i++) {
1183                 if (debug_dump_wdg)
1184                         wmi_dump_wdg(&gblock[i]);
1185
1186                 /*
1187                  * Some WMI devices, like those for nVidia hooks, have a
1188                  * duplicate GUID. It's not clear what we should do in this
1189                  * case yet, so for now, we'll just ignore the duplicate
1190                  * for device creation.
1191                  */
1192                 if (guid_already_parsed(device, gblock[i].guid))
1193                         continue;
1194
1195                 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
1196                 if (!wblock) {
1197                         retval = -ENOMEM;
1198                         break;
1199                 }
1200
1201                 wblock->acpi_device = device;
1202                 wblock->gblock = gblock[i];
1203
1204                 retval = wmi_create_device(wmi_bus_dev, &gblock[i], wblock, device);
1205                 if (retval) {
1206                         kfree(wblock);
1207                         continue;
1208                 }
1209
1210                 list_add_tail(&wblock->list, &wmi_block_list);
1211
1212                 if (debug_event) {
1213                         wblock->handler = wmi_notify_debug;
1214                         wmi_method_enable(wblock, 1);
1215                 }
1216         }
1217
1218         /*
1219          * Now that all of the devices are created, add them to the
1220          * device tree and probe subdrivers.
1221          */
1222         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1223                 if (wblock->acpi_device != device)
1224                         continue;
1225
1226                 retval = device_add(&wblock->dev.dev);
1227                 if (retval) {
1228                         dev_err(wmi_bus_dev, "failed to register %pUL\n",
1229                                 wblock->gblock.guid);
1230                         if (debug_event)
1231                                 wmi_method_enable(wblock, 0);
1232                         list_del(&wblock->list);
1233                         put_device(&wblock->dev.dev);
1234                 }
1235         }
1236
1237 out_free_pointer:
1238         kfree(out.pointer);
1239         return retval;
1240 }
1241
1242 /*
1243  * WMI can have EmbeddedControl access regions. In which case, we just want to
1244  * hand these off to the EC driver.
1245  */
1246 static acpi_status
1247 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1248                       u32 bits, u64 *value,
1249                       void *handler_context, void *region_context)
1250 {
1251         int result = 0, i = 0;
1252         u8 temp = 0;
1253
1254         if ((address > 0xFF) || !value)
1255                 return AE_BAD_PARAMETER;
1256
1257         if (function != ACPI_READ && function != ACPI_WRITE)
1258                 return AE_BAD_PARAMETER;
1259
1260         if (bits != 8)
1261                 return AE_BAD_PARAMETER;
1262
1263         if (function == ACPI_READ) {
1264                 result = ec_read(address, &temp);
1265                 (*value) |= ((u64)temp) << i;
1266         } else {
1267                 temp = 0xff & ((*value) >> i);
1268                 result = ec_write(address, temp);
1269         }
1270
1271         switch (result) {
1272         case -EINVAL:
1273                 return AE_BAD_PARAMETER;
1274         case -ENODEV:
1275                 return AE_NOT_FOUND;
1276         case -ETIME:
1277                 return AE_TIME;
1278         default:
1279                 return AE_OK;
1280         }
1281 }
1282
1283 static void acpi_wmi_notify_handler(acpi_handle handle, u32 event,
1284                                     void *context)
1285 {
1286         struct guid_block *block;
1287         struct wmi_block *wblock;
1288         bool found_it = false;
1289
1290         list_for_each_entry(wblock, &wmi_block_list, list) {
1291                 block = &wblock->gblock;
1292
1293                 if (wblock->acpi_device->handle == handle &&
1294                     (block->flags & ACPI_WMI_EVENT) &&
1295                     (block->notify_id == event))
1296                 {
1297                         found_it = true;
1298                         break;
1299                 }
1300         }
1301
1302         if (!found_it)
1303                 return;
1304
1305         /* If a driver is bound, then notify the driver. */
1306         if (test_bit(WMI_PROBED, &wblock->flags) && wblock->dev.dev.driver) {
1307                 struct wmi_driver *driver = drv_to_wdrv(wblock->dev.dev.driver);
1308                 struct acpi_object_list input;
1309                 union acpi_object params[1];
1310                 struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL };
1311                 acpi_status status;
1312
1313                 input.count = 1;
1314                 input.pointer = params;
1315                 params[0].type = ACPI_TYPE_INTEGER;
1316                 params[0].integer.value = event;
1317
1318                 status = acpi_evaluate_object(wblock->acpi_device->handle,
1319                                               "_WED", &input, &evdata);
1320                 if (ACPI_FAILURE(status)) {
1321                         dev_warn(&wblock->dev.dev,
1322                                  "failed to get event data\n");
1323                         return;
1324                 }
1325
1326                 if (driver->notify)
1327                         driver->notify(&wblock->dev,
1328                                        (union acpi_object *)evdata.pointer);
1329
1330                 kfree(evdata.pointer);
1331         } else if (wblock->handler) {
1332                 /* Legacy handler */
1333                 wblock->handler(event, wblock->handler_data);
1334         }
1335
1336         if (debug_event)
1337                 pr_info("DEBUG Event GUID: %pUL\n", wblock->gblock.guid);
1338
1339         acpi_bus_generate_netlink_event(
1340                 wblock->acpi_device->pnp.device_class,
1341                 dev_name(&wblock->dev.dev),
1342                 event, 0);
1343
1344 }
1345
1346 static int acpi_wmi_remove(struct platform_device *device)
1347 {
1348         struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev);
1349
1350         acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1351                                    acpi_wmi_notify_handler);
1352         acpi_remove_address_space_handler(acpi_device->handle,
1353                                 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
1354         wmi_free_devices(acpi_device);
1355         device_unregister((struct device *)dev_get_drvdata(&device->dev));
1356
1357         return 0;
1358 }
1359
1360 static int acpi_wmi_probe(struct platform_device *device)
1361 {
1362         struct acpi_device *acpi_device;
1363         struct device *wmi_bus_dev;
1364         acpi_status status;
1365         int error;
1366
1367         acpi_device = ACPI_COMPANION(&device->dev);
1368         if (!acpi_device) {
1369                 dev_err(&device->dev, "ACPI companion is missing\n");
1370                 return -ENODEV;
1371         }
1372
1373         status = acpi_install_address_space_handler(acpi_device->handle,
1374                                                     ACPI_ADR_SPACE_EC,
1375                                                     &acpi_wmi_ec_space_handler,
1376                                                     NULL, NULL);
1377         if (ACPI_FAILURE(status)) {
1378                 dev_err(&device->dev, "Error installing EC region handler\n");
1379                 return -ENODEV;
1380         }
1381
1382         status = acpi_install_notify_handler(acpi_device->handle,
1383                                              ACPI_DEVICE_NOTIFY,
1384                                              acpi_wmi_notify_handler,
1385                                              NULL);
1386         if (ACPI_FAILURE(status)) {
1387                 dev_err(&device->dev, "Error installing notify handler\n");
1388                 error = -ENODEV;
1389                 goto err_remove_ec_handler;
1390         }
1391
1392         wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0),
1393                                     NULL, "wmi_bus-%s", dev_name(&device->dev));
1394         if (IS_ERR(wmi_bus_dev)) {
1395                 error = PTR_ERR(wmi_bus_dev);
1396                 goto err_remove_notify_handler;
1397         }
1398         dev_set_drvdata(&device->dev, wmi_bus_dev);
1399
1400         error = parse_wdg(wmi_bus_dev, acpi_device);
1401         if (error) {
1402                 pr_err("Failed to parse WDG method\n");
1403                 goto err_remove_busdev;
1404         }
1405
1406         return 0;
1407
1408 err_remove_busdev:
1409         device_unregister(wmi_bus_dev);
1410
1411 err_remove_notify_handler:
1412         acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1413                                    acpi_wmi_notify_handler);
1414
1415 err_remove_ec_handler:
1416         acpi_remove_address_space_handler(acpi_device->handle,
1417                                           ACPI_ADR_SPACE_EC,
1418                                           &acpi_wmi_ec_space_handler);
1419
1420         return error;
1421 }
1422
1423 int __must_check __wmi_driver_register(struct wmi_driver *driver,
1424                                        struct module *owner)
1425 {
1426         driver->driver.owner = owner;
1427         driver->driver.bus = &wmi_bus_type;
1428
1429         return driver_register(&driver->driver);
1430 }
1431 EXPORT_SYMBOL(__wmi_driver_register);
1432
1433 void wmi_driver_unregister(struct wmi_driver *driver)
1434 {
1435         driver_unregister(&driver->driver);
1436 }
1437 EXPORT_SYMBOL(wmi_driver_unregister);
1438
1439 static int __init acpi_wmi_init(void)
1440 {
1441         int error;
1442
1443         if (acpi_disabled)
1444                 return -ENODEV;
1445
1446         error = class_register(&wmi_bus_class);
1447         if (error)
1448                 return error;
1449
1450         error = bus_register(&wmi_bus_type);
1451         if (error)
1452                 goto err_unreg_class;
1453
1454         error = platform_driver_register(&acpi_wmi_driver);
1455         if (error) {
1456                 pr_err("Error loading mapper\n");
1457                 goto err_unreg_bus;
1458         }
1459
1460         return 0;
1461
1462 err_unreg_bus:
1463         bus_unregister(&wmi_bus_type);
1464
1465 err_unreg_class:
1466         class_unregister(&wmi_bus_class);
1467
1468         return error;
1469 }
1470
1471 static void __exit acpi_wmi_exit(void)
1472 {
1473         platform_driver_unregister(&acpi_wmi_driver);
1474         bus_unregister(&wmi_bus_type);
1475         class_unregister(&wmi_bus_class);
1476 }
1477
1478 subsys_initcall_sync(acpi_wmi_init);
1479 module_exit(acpi_wmi_exit);