drivers/platform/x86/wmi.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  ACPI-WMI mapping driver
   4  *
   5  *  Copyright (C) 2007-2008 Carlos Corbacho <carlos@strangeworlds.co.uk>
   6  *
   7  *  GUID parsing code from ldm.c is:
   8  *   Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
   9  *   Copyright (c) 2001-2007 Anton Altaparmakov
  10  *   Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
  11  *
  12  *  WMI bus infrastructure by Andrew Lutomirski and Darren Hart:
  13  *    Copyright (C) 2015 Andrew Lutomirski
  14  *    Copyright (C) 2017 VMware, Inc. All Rights Reserved.
  15  */
  16
  17 #define pr_fmt(fmt)     KBUILD_MODNAME ": " fmt
  18
  19 #include <linux/acpi.h>
  20 #include <linux/bits.h>
  21 #include <linux/build_bug.h>
  22 #include <linux/device.h>
  23 #include <linux/init.h>
  24 #include <linux/kernel.h>
  25 #include <linux/list.h>
  26 #include <linux/miscdevice.h>
  27 #include <linux/module.h>
  28 #include <linux/platform_device.h>
  29 #include <linux/slab.h>
  30 #include <linux/sysfs.h>
  31 #include <linux/types.h>
  32 #include <linux/uaccess.h>
  33 #include <linux/uuid.h>
  34 #include <linux/wmi.h>
  35 #include <linux/fs.h>
  36 #include <uapi/linux/wmi.h>
  37
  38 MODULE_AUTHOR("Carlos Corbacho");
  39 MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
  40 MODULE_LICENSE("GPL");
  41
  42 static LIST_HEAD(wmi_block_list);
  43
  44 struct guid_block {
  45         guid_t guid;
  46         union {
  47                 char object_id[2];
  48                 struct {
  49                         unsigned char notify_id;
  50                         unsigned char reserved;
  51                 };
  52         };
  53         u8 instance_count;
  54         u8 flags;
  55 } __packed;
  56 static_assert(sizeof(typeof_member(struct guid_block, guid)) == 16);
  57 static_assert(sizeof(struct guid_block) == 20);
  58 static_assert(__alignof__(struct guid_block) == 1);
  59
  60 enum {  /* wmi_block flags */
  61         WMI_READ_TAKES_NO_ARGS,
  62         WMI_PROBED,
  63 };
  64
  65 struct wmi_block {
  66         struct wmi_device dev;
  67         struct list_head list;
  68         struct guid_block gblock;
  69         struct miscdevice char_dev;
  70         struct mutex char_mutex;
  71         struct acpi_device *acpi_device;
  72         wmi_notify_handler handler;
  73         void *handler_data;
  74         u64 req_buf_size;
  75         unsigned long flags;
  76 };
  77
  78
  79 /*
  80  * If the GUID data block is marked as expensive, we must enable and
  81  * explicitily disable data collection.
  82  */
  83 #define ACPI_WMI_EXPENSIVE   BIT(0)
  84 #define ACPI_WMI_METHOD      BIT(1)     /* GUID is a method */
  85 #define ACPI_WMI_STRING      BIT(2)     /* GUID takes & returns a string */
  86 #define ACPI_WMI_EVENT       BIT(3)     /* GUID is an event */
  87
  88 static bool debug_event;
  89 module_param(debug_event, bool, 0444);
  90 MODULE_PARM_DESC(debug_event,
  91                  "Log WMI Events [0/1]");
  92
  93 static bool debug_dump_wdg;
  94 module_param(debug_dump_wdg, bool, 0444);
  95 MODULE_PARM_DESC(debug_dump_wdg,
  96                  "Dump available WMI interfaces [0/1]");
  97
  98 static const struct acpi_device_id wmi_device_ids[] = {
  99         {"PNP0C14", 0},
 100         {"pnp0c14", 0},
 101         { }
 102 };
 103 MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
 104
 105 /* allow duplicate GUIDs as these device drivers use struct wmi_driver */
 106 static const char * const allow_duplicates[] = {
 107         "05901221-D566-11D1-B2F0-00A0C9062910", /* wmi-bmof */
 108         "8A42EA14-4F2A-FD45-6422-0087F7A7E608", /* dell-wmi-ddv */
 109         NULL
 110 };
 111
 112 #define dev_to_wblock(__dev)    container_of_const(__dev, struct wmi_block, dev.dev)
 113 #define dev_to_wdev(__dev)      container_of_const(__dev, struct wmi_device, dev)
 114
 115 /*
 116  * GUID parsing functions
 117  */
 118
 119 static bool guid_parse_and_compare(const char *string, const guid_t *guid)
 120 {
 121         guid_t guid_input;
 122
 123         if (guid_parse(string, &guid_input))
 124                 return false;
 125
 126         return guid_equal(&guid_input, guid);
 127 }
 128
 129 static const void *find_guid_context(struct wmi_block *wblock,
 130                                      struct wmi_driver *wdriver)
 131 {
 132         const struct wmi_device_id *id;
 133
 134         id = wdriver->id_table;
 135         if (!id)
 136                 return NULL;
 137
 138         while (*id->guid_string) {
 139                 if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid))
 140                         return id->context;
 141                 id++;
 142         }
 143         return NULL;
 144 }
 145
 146 static int get_subobj_info(acpi_handle handle, const char *pathname,
 147                            struct acpi_device_info **info)
 148 {
 149         struct acpi_device_info *dummy_info, **info_ptr;
 150         acpi_handle subobj_handle;
 151         acpi_status status;
 152
 153         status = acpi_get_handle(handle, (char *)pathname, &subobj_handle);
 154         if (status == AE_NOT_FOUND)
 155                 return -ENOENT;
 156         else if (ACPI_FAILURE(status))
 157                 return -EIO;
 158
 159         info_ptr = info ? info : &dummy_info;
 160         status = acpi_get_object_info(subobj_handle, info_ptr);
 161         if (ACPI_FAILURE(status))
 162                 return -EIO;
 163
 164         if (!info)
 165                 kfree(dummy_info);
 166
 167         return 0;
 168 }
 169
 170 static acpi_status wmi_method_enable(struct wmi_block *wblock, bool enable)
 171 {
 172         struct guid_block *block;
 173         char method[5];
 174         acpi_status status;
 175         acpi_handle handle;
 176
 177         block = &wblock->gblock;
 178         handle = wblock->acpi_device->handle;
 179
 180         snprintf(method, 5, "WE%02X", block->notify_id);
 181         status = acpi_execute_simple_method(handle, method, enable);
 182         if (status == AE_NOT_FOUND)
 183                 return AE_OK;
 184
 185         return status;
 186 }
 187
 188 #define WMI_ACPI_METHOD_NAME_SIZE 5
 189
 190 static inline void get_acpi_method_name(const struct wmi_block *wblock,
 191                                         const char method,
 192                                         char buffer[static WMI_ACPI_METHOD_NAME_SIZE])
 193 {
 194         static_assert(ARRAY_SIZE(wblock->gblock.object_id) == 2);
 195         static_assert(WMI_ACPI_METHOD_NAME_SIZE >= 5);
 196
 197         buffer[0] = 'W';
 198         buffer[1] = method;
 199         buffer[2] = wblock->gblock.object_id[0];
 200         buffer[3] = wblock->gblock.object_id[1];
 201         buffer[4] = '\0';
 202 }
 203
 204 static inline acpi_object_type get_param_acpi_type(const struct wmi_block *wblock)
 205 {
 206         if (wblock->gblock.flags & ACPI_WMI_STRING)
 207                 return ACPI_TYPE_STRING;
 208         else
 209                 return ACPI_TYPE_BUFFER;
 210 }
 211
 212 static acpi_status get_event_data(const struct wmi_block *wblock, struct acpi_buffer *out)
 213 {
 214         union acpi_object param = {
 215                 .integer = {
 216                         .type = ACPI_TYPE_INTEGER,
 217                         .value = wblock->gblock.notify_id,
 218                 }
 219         };
 220         struct acpi_object_list input = {
 221                 .count = 1,
 222                 .pointer = &param,
 223         };
 224
 225         return acpi_evaluate_object(wblock->acpi_device->handle, "_WED", &input, out);
 226 }
 227
 228 static int wmidev_match_guid(struct device *dev, const void *data)
 229 {
 230         struct wmi_block *wblock = dev_to_wblock(dev);
 231         const guid_t *guid = data;
 232
 233         if (guid_equal(guid, &wblock->gblock.guid))
 234                 return 1;
 235
 236         return 0;
 237 }
 238
 239 static struct bus_type wmi_bus_type;
 240
 241 static struct wmi_device *wmi_find_device_by_guid(const char *guid_string)
 242 {
 243         struct device *dev;
 244         guid_t guid;
 245         int ret;
 246
 247         ret = guid_parse(guid_string, &guid);
 248         if (ret < 0)
 249                 return ERR_PTR(ret);
 250
 251         dev = bus_find_device(&wmi_bus_type, NULL, &guid, wmidev_match_guid);
 252         if (!dev)
 253                 return ERR_PTR(-ENODEV);
 254
 255         return dev_to_wdev(dev);
 256 }
 257
 258 static void wmi_device_put(struct wmi_device *wdev)
 259 {
 260         put_device(&wdev->dev);
 261 }
 262
 263 /*
 264  * Exported WMI functions
 265  */
 266
 267 /**
 268  * set_required_buffer_size - Sets the buffer size needed for performing IOCTL
 269  * @wdev: A wmi bus device from a driver
 270  * @length: Required buffer size
 271  *
 272  * Allocates memory needed for buffer, stores the buffer size in that memory.
 273  *
 274  * Return: 0 on success or a negative error code for failure.
 275  */
 276 int set_required_buffer_size(struct wmi_device *wdev, u64 length)
 277 {
 278         struct wmi_block *wblock;
 279
 280         wblock = container_of(wdev, struct wmi_block, dev);
 281         wblock->req_buf_size = length;
 282
 283         return 0;
 284 }
 285 EXPORT_SYMBOL_GPL(set_required_buffer_size);
 286
 287 /**
 288  * wmi_instance_count - Get number of WMI object instances
 289  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 290  *
 291  * Get the number of WMI object instances.
 292  *
 293  * Returns: Number of WMI object instances or negative error code.
 294  */
 295 int wmi_instance_count(const char *guid_string)
 296 {
 297         struct wmi_device *wdev;
 298         int ret;
 299
 300         wdev = wmi_find_device_by_guid(guid_string);
 301         if (IS_ERR(wdev))
 302                 return PTR_ERR(wdev);
 303
 304         ret = wmidev_instance_count(wdev);
 305         wmi_device_put(wdev);
 306
 307         return ret;
 308 }
 309 EXPORT_SYMBOL_GPL(wmi_instance_count);
 310
 311 /**
 312  * wmidev_instance_count - Get number of WMI object instances
 313  * @wdev: A wmi bus device from a driver
 314  *
 315  * Get the number of WMI object instances.
 316  *
 317  * Returns: Number of WMI object instances.
 318  */
 319 u8 wmidev_instance_count(struct wmi_device *wdev)
 320 {
 321         struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
 322
 323         return wblock->gblock.instance_count;
 324 }
 325 EXPORT_SYMBOL_GPL(wmidev_instance_count);
 326
 327 /**
 328  * wmi_evaluate_method - Evaluate a WMI method (deprecated)
 329  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 330  * @instance: Instance index
 331  * @method_id: Method ID to call
 332  * @in: Buffer containing input for the method call
 333  * @out: Empty buffer to return the method results
 334  *
 335  * Call an ACPI-WMI method, the caller must free @out.
 336  *
 337  * Return: acpi_status signaling success or error.
 338  */
 339 acpi_status wmi_evaluate_method(const char *guid_string, u8 instance, u32 method_id,
 340                                 const struct acpi_buffer *in, struct acpi_buffer *out)
 341 {
 342         struct wmi_device *wdev;
 343         acpi_status status;
 344
 345         wdev = wmi_find_device_by_guid(guid_string);
 346         if (IS_ERR(wdev))
 347                 return AE_ERROR;
 348
 349         status = wmidev_evaluate_method(wdev, instance, method_id, in, out);
 350
 351         wmi_device_put(wdev);
 352
 353         return status;
 354 }
 355 EXPORT_SYMBOL_GPL(wmi_evaluate_method);
 356
 357 /**
 358  * wmidev_evaluate_method - Evaluate a WMI method
 359  * @wdev: A wmi bus device from a driver
 360  * @instance: Instance index
 361  * @method_id: Method ID to call
 362  * @in: Buffer containing input for the method call
 363  * @out: Empty buffer to return the method results
 364  *
 365  * Call an ACPI-WMI method, the caller must free @out.
 366  *
 367  * Return: acpi_status signaling success or error.
 368  */
 369 acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance, u32 method_id,
 370                                    const struct acpi_buffer *in, struct acpi_buffer *out)
 371 {
 372         struct guid_block *block;
 373         struct wmi_block *wblock;
 374         acpi_handle handle;
 375         struct acpi_object_list input;
 376         union acpi_object params[3];
 377         char method[WMI_ACPI_METHOD_NAME_SIZE];
 378
 379         wblock = container_of(wdev, struct wmi_block, dev);
 380         block = &wblock->gblock;
 381         handle = wblock->acpi_device->handle;
 382
 383         if (!(block->flags & ACPI_WMI_METHOD))
 384                 return AE_BAD_DATA;
 385
 386         if (block->instance_count <= instance)
 387                 return AE_BAD_PARAMETER;
 388
 389         input.count = 2;
 390         input.pointer = params;
 391         params[0].type = ACPI_TYPE_INTEGER;
 392         params[0].integer.value = instance;
 393         params[1].type = ACPI_TYPE_INTEGER;
 394         params[1].integer.value = method_id;
 395
 396         if (in) {
 397                 input.count = 3;
 398
 399                 params[2].type = get_param_acpi_type(wblock);
 400                 params[2].buffer.length = in->length;
 401                 params[2].buffer.pointer = in->pointer;
 402         }
 403
 404         get_acpi_method_name(wblock, 'M', method);
 405
 406         return acpi_evaluate_object(handle, method, &input, out);
 407 }
 408 EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
 409
 410 static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
 411                                  struct acpi_buffer *out)
 412 {
 413         struct guid_block *block;
 414         acpi_handle handle;
 415         acpi_status status, wc_status = AE_ERROR;
 416         struct acpi_object_list input;
 417         union acpi_object wq_params[1];
 418         char wc_method[WMI_ACPI_METHOD_NAME_SIZE];
 419         char method[WMI_ACPI_METHOD_NAME_SIZE];
 420
 421         if (!out)
 422                 return AE_BAD_PARAMETER;
 423
 424         block = &wblock->gblock;
 425         handle = wblock->acpi_device->handle;
 426
 427         if (block->instance_count <= instance)
 428                 return AE_BAD_PARAMETER;
 429
 430         /* Check GUID is a data block */
 431         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 432                 return AE_ERROR;
 433
 434         input.count = 1;
 435         input.pointer = wq_params;
 436         wq_params[0].type = ACPI_TYPE_INTEGER;
 437         wq_params[0].integer.value = instance;
 438
 439         if (instance == 0 && test_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags))
 440                 input.count = 0;
 441
 442         /*
 443          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
 444          * enable collection.
 445          */
 446         if (block->flags & ACPI_WMI_EXPENSIVE) {
 447                 get_acpi_method_name(wblock, 'C', wc_method);
 448
 449                 /*
 450                  * Some GUIDs break the specification by declaring themselves
 451                  * expensive, but have no corresponding WCxx method. So we
 452                  * should not fail if this happens.
 453                  */
 454                 wc_status = acpi_execute_simple_method(handle, wc_method, 1);
 455         }
 456
 457         get_acpi_method_name(wblock, 'Q', method);
 458         status = acpi_evaluate_object(handle, method, &input, out);
 459
 460         /*
 461          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
 462          * the WQxx method failed - we should disable collection anyway.
 463          */
 464         if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
 465                 /*
 466                  * Ignore whether this WCxx call succeeds or not since
 467                  * the previously executed WQxx method call might have
 468                  * succeeded, and returning the failing status code
 469                  * of this call would throw away the result of the WQxx
 470                  * call, potentially leaking memory.
 471                  */
 472                 acpi_execute_simple_method(handle, wc_method, 0);
 473         }
 474
 475         return status;
 476 }
 477
 478 /**
 479  * wmi_query_block - Return contents of a WMI block (deprecated)
 480  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 481  * @instance: Instance index
 482  * @out: Empty buffer to return the contents of the data block to
 483  *
 484  * Query a ACPI-WMI block, the caller must free @out.
 485  *
 486  * Return: ACPI object containing the content of the WMI block.
 487  */
 488 acpi_status wmi_query_block(const char *guid_string, u8 instance,
 489                             struct acpi_buffer *out)
 490 {
 491         struct wmi_block *wblock;
 492         struct wmi_device *wdev;
 493         acpi_status status;
 494
 495         wdev = wmi_find_device_by_guid(guid_string);
 496         if (IS_ERR(wdev))
 497                 return AE_ERROR;
 498
 499         wblock = container_of(wdev, struct wmi_block, dev);
 500         status = __query_block(wblock, instance, out);
 501
 502         wmi_device_put(wdev);
 503
 504         return status;
 505 }
 506 EXPORT_SYMBOL_GPL(wmi_query_block);
 507
 508 /**
 509  * wmidev_block_query - Return contents of a WMI block
 510  * @wdev: A wmi bus device from a driver
 511  * @instance: Instance index
 512  *
 513  * Query an ACPI-WMI block, the caller must free the result.
 514  *
 515  * Return: ACPI object containing the content of the WMI block.
 516  */
 517 union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
 518 {
 519         struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
 520         struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
 521
 522         if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
 523                 return NULL;
 524
 525         return out.pointer;
 526 }
 527 EXPORT_SYMBOL_GPL(wmidev_block_query);
 528
 529 /**
 530  * wmi_set_block - Write to a WMI block (deprecated)
 531  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 532  * @instance: Instance index
 533  * @in: Buffer containing new values for the data block
 534  *
 535  * Write the contents of the input buffer to an ACPI-WMI data block.
 536  *
 537  * Return: acpi_status signaling success or error.
 538  */
 539 acpi_status wmi_set_block(const char *guid_string, u8 instance,
 540                           const struct acpi_buffer *in)
 541 {
 542         struct wmi_block *wblock;
 543         struct guid_block *block;
 544         struct wmi_device *wdev;
 545         acpi_handle handle;
 546         struct acpi_object_list input;
 547         union acpi_object params[2];
 548         char method[WMI_ACPI_METHOD_NAME_SIZE];
 549         acpi_status status;
 550
 551         if (!in)
 552                 return AE_BAD_DATA;
 553
 554         wdev = wmi_find_device_by_guid(guid_string);
 555         if (IS_ERR(wdev))
 556                 return AE_ERROR;
 557
 558         wblock = container_of(wdev, struct wmi_block, dev);
 559         block = &wblock->gblock;
 560         handle = wblock->acpi_device->handle;
 561
 562         if (block->instance_count <= instance) {
 563                 status = AE_BAD_PARAMETER;
 564
 565                 goto err_wdev_put;
 566         }
 567
 568         /* Check GUID is a data block */
 569         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD)) {
 570                 status = AE_ERROR;
 571
 572                 goto err_wdev_put;
 573         }
 574
 575         input.count = 2;
 576         input.pointer = params;
 577         params[0].type = ACPI_TYPE_INTEGER;
 578         params[0].integer.value = instance;
 579         params[1].type = get_param_acpi_type(wblock);
 580         params[1].buffer.length = in->length;
 581         params[1].buffer.pointer = in->pointer;
 582
 583         get_acpi_method_name(wblock, 'S', method);
 584
 585         status = acpi_evaluate_object(handle, method, &input, NULL);
 586
 587 err_wdev_put:
 588         wmi_device_put(wdev);
 589
 590         return status;
 591 }
 592 EXPORT_SYMBOL_GPL(wmi_set_block);
 593
 594 static void wmi_dump_wdg(const struct guid_block *g)
 595 {
 596         pr_info("%pUL:\n", &g->guid);
 597         if (g->flags & ACPI_WMI_EVENT)
 598                 pr_info("\tnotify_id: 0x%02X\n", g->notify_id);
 599         else
 600                 pr_info("\tobject_id: %2pE\n", g->object_id);
 601         pr_info("\tinstance_count: %d\n", g->instance_count);
 602         pr_info("\tflags: %#x", g->flags);
 603         if (g->flags) {
 604                 if (g->flags & ACPI_WMI_EXPENSIVE)
 605                         pr_cont(" ACPI_WMI_EXPENSIVE");
 606                 if (g->flags & ACPI_WMI_METHOD)
 607                         pr_cont(" ACPI_WMI_METHOD");
 608                 if (g->flags & ACPI_WMI_STRING)
 609                         pr_cont(" ACPI_WMI_STRING");
 610                 if (g->flags & ACPI_WMI_EVENT)
 611                         pr_cont(" ACPI_WMI_EVENT");
 612         }
 613         pr_cont("\n");
 614
 615 }
 616
 617 static void wmi_notify_debug(u32 value, void *context)
 618 {
 619         struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
 620         union acpi_object *obj;
 621         acpi_status status;
 622
 623         status = wmi_get_event_data(value, &response);
 624         if (status != AE_OK) {
 625                 pr_info("bad event status 0x%x\n", status);
 626                 return;
 627         }
 628
 629         obj = response.pointer;
 630         if (!obj)
 631                 return;
 632
 633         pr_info("DEBUG: event 0x%02X ", value);
 634         switch (obj->type) {
 635         case ACPI_TYPE_BUFFER:
 636                 pr_cont("BUFFER_TYPE - length %u\n", obj->buffer.length);
 637                 break;
 638         case ACPI_TYPE_STRING:
 639                 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
 640                 break;
 641         case ACPI_TYPE_INTEGER:
 642                 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
 643                 break;
 644         case ACPI_TYPE_PACKAGE:
 645                 pr_cont("PACKAGE_TYPE - %u elements\n", obj->package.count);
 646                 break;
 647         default:
 648                 pr_cont("object type 0x%X\n", obj->type);
 649         }
 650         kfree(obj);
 651 }
 652
 653 /**
 654  * wmi_install_notify_handler - Register handler for WMI events (deprecated)
 655  * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 656  * @handler: Function to handle notifications
 657  * @data: Data to be returned to handler when event is fired
 658  *
 659  * Register a handler for events sent to the ACPI-WMI mapper device.
 660  *
 661  * Return: acpi_status signaling success or error.
 662  */
 663 acpi_status wmi_install_notify_handler(const char *guid,
 664                                        wmi_notify_handler handler,
 665                                        void *data)
 666 {
 667         struct wmi_block *block;
 668         acpi_status status = AE_NOT_EXIST;
 669         guid_t guid_input;
 670
 671         if (!guid || !handler)
 672                 return AE_BAD_PARAMETER;
 673
 674         if (guid_parse(guid, &guid_input))
 675                 return AE_BAD_PARAMETER;
 676
 677         list_for_each_entry(block, &wmi_block_list, list) {
 678                 acpi_status wmi_status;
 679
 680                 if (guid_equal(&block->gblock.guid, &guid_input)) {
 681                         if (block->handler &&
 682                             block->handler != wmi_notify_debug)
 683                                 return AE_ALREADY_ACQUIRED;
 684
 685                         block->handler = handler;
 686                         block->handler_data = data;
 687
 688                         wmi_status = wmi_method_enable(block, true);
 689                         if ((wmi_status != AE_OK) ||
 690                             ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
 691                                 status = wmi_status;
 692                 }
 693         }
 694
 695         return status;
 696 }
 697 EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
 698
 699 /**
 700  * wmi_remove_notify_handler - Unregister handler for WMI events (deprecated)
 701  * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 702  *
 703  * Unregister handler for events sent to the ACPI-WMI mapper device.
 704  *
 705  * Return: acpi_status signaling success or error.
 706  */
 707 acpi_status wmi_remove_notify_handler(const char *guid)
 708 {
 709         struct wmi_block *block;
 710         acpi_status status = AE_NOT_EXIST;
 711         guid_t guid_input;
 712
 713         if (!guid)
 714                 return AE_BAD_PARAMETER;
 715
 716         if (guid_parse(guid, &guid_input))
 717                 return AE_BAD_PARAMETER;
 718
 719         list_for_each_entry(block, &wmi_block_list, list) {
 720                 acpi_status wmi_status;
 721
 722                 if (guid_equal(&block->gblock.guid, &guid_input)) {
 723                         if (!block->handler ||
 724                             block->handler == wmi_notify_debug)
 725                                 return AE_NULL_ENTRY;
 726
 727                         if (debug_event) {
 728                                 block->handler = wmi_notify_debug;
 729                                 status = AE_OK;
 730                         } else {
 731                                 wmi_status = wmi_method_enable(block, false);
 732                                 block->handler = NULL;
 733                                 block->handler_data = NULL;
 734                                 if ((wmi_status != AE_OK) ||
 735                                     ((wmi_status == AE_OK) &&
 736                                      (status == AE_NOT_EXIST)))
 737                                         status = wmi_status;
 738                         }
 739                 }
 740         }
 741
 742         return status;
 743 }
 744 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
 745
 746 /**
 747  * wmi_get_event_data - Get WMI data associated with an event (deprecated)
 748  *
 749  * @event: Event to find
 750  * @out: Buffer to hold event data
 751  *
 752  * Get extra data associated with an WMI event, the caller needs to free @out.
 753  *
 754  * Return: acpi_status signaling success or error.
 755  */
 756 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
 757 {
 758         struct wmi_block *wblock;
 759
 760         list_for_each_entry(wblock, &wmi_block_list, list) {
 761                 struct guid_block *gblock = &wblock->gblock;
 762
 763                 if ((gblock->flags & ACPI_WMI_EVENT) && gblock->notify_id == event)
 764                         return get_event_data(wblock, out);
 765         }
 766
 767         return AE_NOT_FOUND;
 768 }
 769 EXPORT_SYMBOL_GPL(wmi_get_event_data);
 770
 771 /**
 772  * wmi_has_guid - Check if a GUID is available
 773  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 774  *
 775  * Check if a given GUID is defined by _WDG.
 776  *
 777  * Return: True if GUID is available, false otherwise.
 778  */
 779 bool wmi_has_guid(const char *guid_string)
 780 {
 781         struct wmi_device *wdev;
 782
 783         wdev = wmi_find_device_by_guid(guid_string);
 784         if (IS_ERR(wdev))
 785                 return false;
 786
 787         wmi_device_put(wdev);
 788
 789         return true;
 790 }
 791 EXPORT_SYMBOL_GPL(wmi_has_guid);
 792
 793 /**
 794  * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID (deprecated)
 795  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 796  *
 797  * Find the _UID of ACPI device associated with this WMI GUID.
 798  *
 799  * Return: The ACPI _UID field value or NULL if the WMI GUID was not found.
 800  */
 801 char *wmi_get_acpi_device_uid(const char *guid_string)
 802 {
 803         struct wmi_block *wblock;
 804         struct wmi_device *wdev;
 805         char *uid;
 806
 807         wdev = wmi_find_device_by_guid(guid_string);
 808         if (IS_ERR(wdev))
 809                 return NULL;
 810
 811         wblock = container_of(wdev, struct wmi_block, dev);
 812         uid = acpi_device_uid(wblock->acpi_device);
 813
 814         wmi_device_put(wdev);
 815
 816         return uid;
 817 }
 818 EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
 819
 820 static inline struct wmi_driver *drv_to_wdrv(struct device_driver *drv)
 821 {
 822         return container_of(drv, struct wmi_driver, driver);
 823 }
 824
 825 /*
 826  * sysfs interface
 827  */
 828 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 829                              char *buf)
 830 {
 831         struct wmi_block *wblock = dev_to_wblock(dev);
 832
 833         return sysfs_emit(buf, "wmi:%pUL\n", &wblock->gblock.guid);
 834 }
 835 static DEVICE_ATTR_RO(modalias);
 836
 837 static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
 838                          char *buf)
 839 {
 840         struct wmi_block *wblock = dev_to_wblock(dev);
 841
 842         return sysfs_emit(buf, "%pUL\n", &wblock->gblock.guid);
 843 }
 844 static DEVICE_ATTR_RO(guid);
 845
 846 static ssize_t instance_count_show(struct device *dev,
 847                                    struct device_attribute *attr, char *buf)
 848 {
 849         struct wmi_block *wblock = dev_to_wblock(dev);
 850
 851         return sysfs_emit(buf, "%d\n", (int)wblock->gblock.instance_count);
 852 }
 853 static DEVICE_ATTR_RO(instance_count);
 854
 855 static ssize_t expensive_show(struct device *dev,
 856                               struct device_attribute *attr, char *buf)
 857 {
 858         struct wmi_block *wblock = dev_to_wblock(dev);
 859
 860         return sysfs_emit(buf, "%d\n",
 861                           (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
 862 }
 863 static DEVICE_ATTR_RO(expensive);
 864
 865 static struct attribute *wmi_attrs[] = {
 866         &dev_attr_modalias.attr,
 867         &dev_attr_guid.attr,
 868         &dev_attr_instance_count.attr,
 869         &dev_attr_expensive.attr,
 870         NULL
 871 };
 872 ATTRIBUTE_GROUPS(wmi);
 873
 874 static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
 875                               char *buf)
 876 {
 877         struct wmi_block *wblock = dev_to_wblock(dev);
 878
 879         return sysfs_emit(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
 880 }
 881 static DEVICE_ATTR_RO(notify_id);
 882
 883 static struct attribute *wmi_event_attrs[] = {
 884         &dev_attr_notify_id.attr,
 885         NULL
 886 };
 887 ATTRIBUTE_GROUPS(wmi_event);
 888
 889 static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
 890                               char *buf)
 891 {
 892         struct wmi_block *wblock = dev_to_wblock(dev);
 893
 894         return sysfs_emit(buf, "%c%c\n", wblock->gblock.object_id[0],
 895                           wblock->gblock.object_id[1]);
 896 }
 897 static DEVICE_ATTR_RO(object_id);
 898
 899 static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
 900                             char *buf)
 901 {
 902         struct wmi_device *wdev = dev_to_wdev(dev);
 903
 904         return sysfs_emit(buf, "%d\n", (int)wdev->setable);
 905 }
 906 static DEVICE_ATTR_RO(setable);
 907
 908 static struct attribute *wmi_data_attrs[] = {
 909         &dev_attr_object_id.attr,
 910         &dev_attr_setable.attr,
 911         NULL
 912 };
 913 ATTRIBUTE_GROUPS(wmi_data);
 914
 915 static struct attribute *wmi_method_attrs[] = {
 916         &dev_attr_object_id.attr,
 917         NULL
 918 };
 919 ATTRIBUTE_GROUPS(wmi_method);
 920
 921 static int wmi_dev_uevent(const struct device *dev, struct kobj_uevent_env *env)
 922 {
 923         const struct wmi_block *wblock = dev_to_wblock(dev);
 924
 925         if (add_uevent_var(env, "MODALIAS=wmi:%pUL", &wblock->gblock.guid))
 926                 return -ENOMEM;
 927
 928         if (add_uevent_var(env, "WMI_GUID=%pUL", &wblock->gblock.guid))
 929                 return -ENOMEM;
 930
 931         return 0;
 932 }
 933
 934 static void wmi_dev_release(struct device *dev)
 935 {
 936         struct wmi_block *wblock = dev_to_wblock(dev);
 937
 938         kfree(wblock);
 939 }
 940
 941 static int wmi_dev_match(struct device *dev, struct device_driver *driver)
 942 {
 943         struct wmi_driver *wmi_driver = drv_to_wdrv(driver);
 944         struct wmi_block *wblock = dev_to_wblock(dev);
 945         const struct wmi_device_id *id = wmi_driver->id_table;
 946
 947         if (id == NULL)
 948                 return 0;
 949
 950         while (*id->guid_string) {
 951                 if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid))
 952                         return 1;
 953
 954                 id++;
 955         }
 956
 957         return 0;
 958 }
 959 static int wmi_char_open(struct inode *inode, struct file *filp)
 960 {
 961         /*
 962          * The miscdevice already stores a pointer to itself
 963          * inside filp->private_data
 964          */
 965         struct wmi_block *wblock = container_of(filp->private_data, struct wmi_block, char_dev);
 966
 967         filp->private_data = wblock;
 968
 969         return nonseekable_open(inode, filp);
 970 }
 971
 972 static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
 973                              size_t length, loff_t *offset)
 974 {
 975         struct wmi_block *wblock = filp->private_data;
 976
 977         return simple_read_from_buffer(buffer, length, offset,
 978                                        &wblock->req_buf_size,
 979                                        sizeof(wblock->req_buf_size));
 980 }
 981
 982 static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 983 {
 984         struct wmi_ioctl_buffer __user *input =
 985                 (struct wmi_ioctl_buffer __user *) arg;
 986         struct wmi_block *wblock = filp->private_data;
 987         struct wmi_ioctl_buffer *buf;
 988         struct wmi_driver *wdriver;
 989         int ret;
 990
 991         if (_IOC_TYPE(cmd) != WMI_IOC)
 992                 return -ENOTTY;
 993
 994         /* make sure we're not calling a higher instance than exists*/
 995         if (_IOC_NR(cmd) >= wblock->gblock.instance_count)
 996                 return -EINVAL;
 997
 998         mutex_lock(&wblock->char_mutex);
 999         buf = wblock->handler_data;
1000         if (get_user(buf->length, &input->length)) {
1001                 dev_dbg(&wblock->dev.dev, "Read length from user failed\n");
1002                 ret = -EFAULT;
1003                 goto out_ioctl;
1004         }
1005         /* if it's too small, abort */
1006         if (buf->length < wblock->req_buf_size) {
1007                 dev_err(&wblock->dev.dev,
1008                         "Buffer %lld too small, need at least %lld\n",
1009                         buf->length, wblock->req_buf_size);
1010                 ret = -EINVAL;
1011                 goto out_ioctl;
1012         }
1013         /* if it's too big, warn, driver will only use what is needed */
1014         if (buf->length > wblock->req_buf_size)
1015                 dev_warn(&wblock->dev.dev,
1016                         "Buffer %lld is bigger than required %lld\n",
1017                         buf->length, wblock->req_buf_size);
1018
1019         /* copy the structure from userspace */
1020         if (copy_from_user(buf, input, wblock->req_buf_size)) {
1021                 dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n",
1022                         wblock->req_buf_size);
1023                 ret = -EFAULT;
1024                 goto out_ioctl;
1025         }
1026
1027         /* let the driver do any filtering and do the call */
1028         wdriver = drv_to_wdrv(wblock->dev.dev.driver);
1029         if (!try_module_get(wdriver->driver.owner)) {
1030                 ret = -EBUSY;
1031                 goto out_ioctl;
1032         }
1033         ret = wdriver->filter_callback(&wblock->dev, cmd, buf);
1034         module_put(wdriver->driver.owner);
1035         if (ret)
1036                 goto out_ioctl;
1037
1038         /* return the result (only up to our internal buffer size) */
1039         if (copy_to_user(input, buf, wblock->req_buf_size)) {
1040                 dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n",
1041                         wblock->req_buf_size);
1042                 ret = -EFAULT;
1043         }
1044
1045 out_ioctl:
1046         mutex_unlock(&wblock->char_mutex);
1047         return ret;
1048 }
1049
1050 static const struct file_operations wmi_fops = {
1051         .owner          = THIS_MODULE,
1052         .read           = wmi_char_read,
1053         .open           = wmi_char_open,
1054         .unlocked_ioctl = wmi_ioctl,
1055         .compat_ioctl   = compat_ptr_ioctl,
1056 };
1057
1058 static int wmi_dev_probe(struct device *dev)
1059 {
1060         struct wmi_block *wblock = dev_to_wblock(dev);
1061         struct wmi_driver *wdriver = drv_to_wdrv(dev->driver);
1062         int ret = 0;
1063         char *buf;
1064
1065         if (ACPI_FAILURE(wmi_method_enable(wblock, true)))
1066                 dev_warn(dev, "failed to enable device -- probing anyway\n");
1067
1068         if (wdriver->probe) {
1069                 ret = wdriver->probe(dev_to_wdev(dev),
1070                                 find_guid_context(wblock, wdriver));
1071                 if (ret != 0)
1072                         goto probe_failure;
1073         }
1074
1075         /* driver wants a character device made */
1076         if (wdriver->filter_callback) {
1077                 /* check that required buffer size declared by driver or MOF */
1078                 if (!wblock->req_buf_size) {
1079                         dev_err(&wblock->dev.dev,
1080                                 "Required buffer size not set\n");
1081                         ret = -EINVAL;
1082                         goto probe_failure;
1083                 }
1084
1085                 wblock->handler_data = kmalloc(wblock->req_buf_size,
1086                                                GFP_KERNEL);
1087                 if (!wblock->handler_data) {
1088                         ret = -ENOMEM;
1089                         goto probe_failure;
1090                 }
1091
1092                 buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name);
1093                 if (!buf) {
1094                         ret = -ENOMEM;
1095                         goto probe_string_failure;
1096                 }
1097                 wblock->char_dev.minor = MISC_DYNAMIC_MINOR;
1098                 wblock->char_dev.name = buf;
1099                 wblock->char_dev.fops = &wmi_fops;
1100                 wblock->char_dev.mode = 0444;
1101                 ret = misc_register(&wblock->char_dev);
1102                 if (ret) {
1103                         dev_warn(dev, "failed to register char dev: %d\n", ret);
1104                         ret = -ENOMEM;
1105                         goto probe_misc_failure;
1106                 }
1107         }
1108
1109         set_bit(WMI_PROBED, &wblock->flags);
1110         return 0;
1111
1112 probe_misc_failure:
1113         kfree(buf);
1114 probe_string_failure:
1115         kfree(wblock->handler_data);
1116 probe_failure:
1117         if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
1118                 dev_warn(dev, "failed to disable device\n");
1119         return ret;
1120 }
1121
1122 static void wmi_dev_remove(struct device *dev)
1123 {
1124         struct wmi_block *wblock = dev_to_wblock(dev);
1125         struct wmi_driver *wdriver = drv_to_wdrv(dev->driver);
1126
1127         clear_bit(WMI_PROBED, &wblock->flags);
1128
1129         if (wdriver->filter_callback) {
1130                 misc_deregister(&wblock->char_dev);
1131                 kfree(wblock->char_dev.name);
1132                 kfree(wblock->handler_data);
1133         }
1134
1135         if (wdriver->remove)
1136                 wdriver->remove(dev_to_wdev(dev));
1137
1138         if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
1139                 dev_warn(dev, "failed to disable device\n");
1140 }
1141
1142 static struct class wmi_bus_class = {
1143         .name = "wmi_bus",
1144 };
1145
1146 static struct bus_type wmi_bus_type = {
1147         .name = "wmi",
1148         .dev_groups = wmi_groups,
1149         .match = wmi_dev_match,
1150         .uevent = wmi_dev_uevent,
1151         .probe = wmi_dev_probe,
1152         .remove = wmi_dev_remove,
1153 };
1154
1155 static const struct device_type wmi_type_event = {
1156         .name = "event",
1157         .groups = wmi_event_groups,
1158         .release = wmi_dev_release,
1159 };
1160
1161 static const struct device_type wmi_type_method = {
1162         .name = "method",
1163         .groups = wmi_method_groups,
1164         .release = wmi_dev_release,
1165 };
1166
1167 static const struct device_type wmi_type_data = {
1168         .name = "data",
1169         .groups = wmi_data_groups,
1170         .release = wmi_dev_release,
1171 };
1172
1173 /*
1174  * _WDG is a static list that is only parsed at startup,
1175  * so it's safe to count entries without extra protection.
1176  */
1177 static int guid_count(const guid_t *guid)
1178 {
1179         struct wmi_block *wblock;
1180         int count = 0;
1181
1182         list_for_each_entry(wblock, &wmi_block_list, list) {
1183                 if (guid_equal(&wblock->gblock.guid, guid))
1184                         count++;
1185         }
1186
1187         return count;
1188 }
1189
1190 static int wmi_create_device(struct device *wmi_bus_dev,
1191                              struct wmi_block *wblock,
1192                              struct acpi_device *device)
1193 {
1194         struct acpi_device_info *info;
1195         char method[WMI_ACPI_METHOD_NAME_SIZE];
1196         int result;
1197         uint count;
1198
1199         if (wblock->gblock.flags & ACPI_WMI_EVENT) {
1200                 wblock->dev.dev.type = &wmi_type_event;
1201                 goto out_init;
1202         }
1203
1204         if (wblock->gblock.flags & ACPI_WMI_METHOD) {
1205                 wblock->dev.dev.type = &wmi_type_method;
1206                 mutex_init(&wblock->char_mutex);
1207                 goto out_init;
1208         }
1209
1210         /*
1211          * Data Block Query Control Method (WQxx by convention) is
1212          * required per the WMI documentation. If it is not present,
1213          * we ignore this data block.
1214          */
1215         get_acpi_method_name(wblock, 'Q', method);
1216         result = get_subobj_info(device->handle, method, &info);
1217
1218         if (result) {
1219                 dev_warn(wmi_bus_dev,
1220                          "%s data block query control method not found\n",
1221                          method);
1222                 return result;
1223         }
1224
1225         wblock->dev.dev.type = &wmi_type_data;
1226
1227         /*
1228          * The Microsoft documentation specifically states:
1229          *
1230          *   Data blocks registered with only a single instance
1231          *   can ignore the parameter.
1232          *
1233          * ACPICA will get mad at us if we call the method with the wrong number
1234          * of arguments, so check what our method expects.  (On some Dell
1235          * laptops, WQxx may not be a method at all.)
1236          */
1237         if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1238                 set_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags);
1239
1240         kfree(info);
1241
1242         get_acpi_method_name(wblock, 'S', method);
1243         result = get_subobj_info(device->handle, method, NULL);
1244
1245         if (result == 0)
1246                 wblock->dev.setable = true;
1247
1248  out_init:
1249         wblock->dev.dev.bus = &wmi_bus_type;
1250         wblock->dev.dev.parent = wmi_bus_dev;
1251
1252         count = guid_count(&wblock->gblock.guid);
1253         if (count)
1254                 dev_set_name(&wblock->dev.dev, "%pUL-%d", &wblock->gblock.guid, count);
1255         else
1256                 dev_set_name(&wblock->dev.dev, "%pUL", &wblock->gblock.guid);
1257
1258         device_initialize(&wblock->dev.dev);
1259
1260         return 0;
1261 }
1262
1263 static int wmi_add_device(struct platform_device *pdev, struct wmi_device *wdev)
1264 {
1265         struct device_link *link;
1266
1267         /*
1268          * Many aggregate WMI drivers do not use -EPROBE_DEFER when they
1269          * are unable to find a WMI device during probe, instead they require
1270          * all WMI devices associated with an platform device to become available
1271          * at once. This device link thus prevents WMI drivers from probing until
1272          * the associated platform device has finished probing (and has registered
1273          * all discovered WMI devices).
1274          */
1275
1276         link = device_link_add(&wdev->dev, &pdev->dev, DL_FLAG_AUTOREMOVE_SUPPLIER);
1277         if (!link)
1278                 return -EINVAL;
1279
1280         return device_add(&wdev->dev);
1281 }
1282
1283 static bool guid_already_parsed_for_legacy(struct acpi_device *device, const guid_t *guid)
1284 {
1285         struct wmi_block *wblock;
1286
1287         list_for_each_entry(wblock, &wmi_block_list, list) {
1288                 /* skip warning and register if we know the driver will use struct wmi_driver */
1289                 for (int i = 0; allow_duplicates[i] != NULL; i++) {
1290                         if (guid_parse_and_compare(allow_duplicates[i], guid))
1291                                 return false;
1292                 }
1293                 if (guid_equal(&wblock->gblock.guid, guid)) {
1294                         /*
1295                          * Because we historically didn't track the relationship
1296                          * between GUIDs and ACPI nodes, we don't know whether
1297                          * we need to suppress GUIDs that are unique on a
1298                          * given node but duplicated across nodes.
1299                          */
1300                         dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
1301                                  guid, dev_name(&wblock->acpi_device->dev));
1302                         return true;
1303                 }
1304         }
1305
1306         return false;
1307 }
1308
1309 /*
1310  * Parse the _WDG method for the GUID data blocks
1311  */
1312 static int parse_wdg(struct device *wmi_bus_dev, struct platform_device *pdev)
1313 {
1314         struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
1315         struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1316         const struct guid_block *gblock;
1317         struct wmi_block *wblock;
1318         union acpi_object *obj;
1319         acpi_status status;
1320         u32 i, total;
1321         int retval;
1322
1323         status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1324         if (ACPI_FAILURE(status))
1325                 return -ENXIO;
1326
1327         obj = out.pointer;
1328         if (!obj)
1329                 return -ENXIO;
1330
1331         if (obj->type != ACPI_TYPE_BUFFER) {
1332                 kfree(obj);
1333                 return -ENXIO;
1334         }
1335
1336         gblock = (const struct guid_block *)obj->buffer.pointer;
1337         total = obj->buffer.length / sizeof(struct guid_block);
1338
1339         for (i = 0; i < total; i++) {
1340                 if (debug_dump_wdg)
1341                         wmi_dump_wdg(&gblock[i]);
1342
1343                 if (guid_already_parsed_for_legacy(device, &gblock[i].guid))
1344                         continue;
1345
1346                 wblock = kzalloc(sizeof(*wblock), GFP_KERNEL);
1347                 if (!wblock) {
1348                         dev_err(wmi_bus_dev, "Failed to allocate %pUL\n", &gblock[i].guid);
1349                         continue;
1350                 }
1351
1352                 wblock->acpi_device = device;
1353                 wblock->gblock = gblock[i];
1354
1355                 retval = wmi_create_device(wmi_bus_dev, wblock, device);
1356                 if (retval) {
1357                         kfree(wblock);
1358                         continue;
1359                 }
1360
1361                 list_add_tail(&wblock->list, &wmi_block_list);
1362
1363                 if (debug_event) {
1364                         wblock->handler = wmi_notify_debug;
1365                         wmi_method_enable(wblock, true);
1366                 }
1367
1368                 retval = wmi_add_device(pdev, &wblock->dev);
1369                 if (retval) {
1370                         dev_err(wmi_bus_dev, "failed to register %pUL\n",
1371                                 &wblock->gblock.guid);
1372                         if (debug_event)
1373                                 wmi_method_enable(wblock, false);
1374
1375                         list_del(&wblock->list);
1376                         put_device(&wblock->dev.dev);
1377                 }
1378         }
1379
1380         kfree(obj);
1381
1382         return 0;
1383 }
1384
1385 /*
1386  * WMI can have EmbeddedControl access regions. In which case, we just want to
1387  * hand these off to the EC driver.
1388  */
1389 static acpi_status
1390 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1391                           u32 bits, u64 *value,
1392                           void *handler_context, void *region_context)
1393 {
1394         int result = 0, i = 0;
1395         u8 temp = 0;
1396
1397         if ((address > 0xFF) || !value)
1398                 return AE_BAD_PARAMETER;
1399
1400         if (function != ACPI_READ && function != ACPI_WRITE)
1401                 return AE_BAD_PARAMETER;
1402
1403         if (bits != 8)
1404                 return AE_BAD_PARAMETER;
1405
1406         if (function == ACPI_READ) {
1407                 result = ec_read(address, &temp);
1408                 (*value) |= ((u64)temp) << i;
1409         } else {
1410                 temp = 0xff & ((*value) >> i);
1411                 result = ec_write(address, temp);
1412         }
1413
1414         switch (result) {
1415         case -EINVAL:
1416                 return AE_BAD_PARAMETER;
1417         case -ENODEV:
1418                 return AE_NOT_FOUND;
1419         case -ETIME:
1420                 return AE_TIME;
1421         default:
1422                 return AE_OK;
1423         }
1424 }
1425
1426 static void acpi_wmi_notify_handler(acpi_handle handle, u32 event,
1427                                     void *context)
1428 {
1429         struct wmi_block *wblock = NULL, *iter;
1430
1431         list_for_each_entry(iter, &wmi_block_list, list) {
1432                 struct guid_block *block = &iter->gblock;
1433
1434                 if (iter->acpi_device->handle == handle &&
1435                     (block->flags & ACPI_WMI_EVENT) &&
1436                     (block->notify_id == event)) {
1437                         wblock = iter;
1438                         break;
1439                 }
1440         }
1441
1442         if (!wblock)
1443                 return;
1444
1445         /* If a driver is bound, then notify the driver. */
1446         if (test_bit(WMI_PROBED, &wblock->flags) && wblock->dev.dev.driver) {
1447                 struct wmi_driver *driver = drv_to_wdrv(wblock->dev.dev.driver);
1448                 struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL };
1449                 acpi_status status;
1450
1451                 if (!driver->no_notify_data) {
1452                         status = get_event_data(wblock, &evdata);
1453                         if (ACPI_FAILURE(status)) {
1454                                 dev_warn(&wblock->dev.dev, "failed to get event data\n");
1455                                 return;
1456                         }
1457                 }
1458
1459                 if (driver->notify)
1460                         driver->notify(&wblock->dev, evdata.pointer);
1461
1462                 kfree(evdata.pointer);
1463         } else if (wblock->handler) {
1464                 /* Legacy handler */
1465                 wblock->handler(event, wblock->handler_data);
1466         }
1467
1468         if (debug_event)
1469                 pr_info("DEBUG: GUID %pUL event 0x%02X\n", &wblock->gblock.guid, event);
1470
1471         acpi_bus_generate_netlink_event(
1472                 wblock->acpi_device->pnp.device_class,
1473                 dev_name(&wblock->dev.dev),
1474                 event, 0);
1475 }
1476
1477 static int wmi_remove_device(struct device *dev, void *data)
1478 {
1479         struct wmi_block *wblock = dev_to_wblock(dev);
1480
1481         list_del(&wblock->list);
1482         device_unregister(dev);
1483
1484         return 0;
1485 }
1486
1487 static void acpi_wmi_remove(struct platform_device *device)
1488 {
1489         struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev);
1490         struct device *wmi_bus_device = dev_get_drvdata(&device->dev);
1491
1492         acpi_remove_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY,
1493                                    acpi_wmi_notify_handler);
1494         acpi_remove_address_space_handler(acpi_device->handle,
1495                                 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
1496
1497         device_for_each_child_reverse(wmi_bus_device, NULL, wmi_remove_device);
1498         device_unregister(wmi_bus_device);
1499 }
1500
1501 static int acpi_wmi_probe(struct platform_device *device)
1502 {
1503         struct acpi_device *acpi_device;
1504         struct device *wmi_bus_dev;
1505         acpi_status status;
1506         int error;
1507
1508         acpi_device = ACPI_COMPANION(&device->dev);
1509         if (!acpi_device) {
1510                 dev_err(&device->dev, "ACPI companion is missing\n");
1511                 return -ENODEV;
1512         }
1513
1514         status = acpi_install_address_space_handler(acpi_device->handle,
1515                                                     ACPI_ADR_SPACE_EC,
1516                                                     &acpi_wmi_ec_space_handler,
1517                                                     NULL, NULL);
1518         if (ACPI_FAILURE(status)) {
1519                 dev_err(&device->dev, "Error installing EC region handler\n");
1520                 return -ENODEV;
1521         }
1522
1523         status = acpi_install_notify_handler(acpi_device->handle,
1524                                              ACPI_ALL_NOTIFY,
1525                                              acpi_wmi_notify_handler,
1526                                              NULL);
1527         if (ACPI_FAILURE(status)) {
1528                 dev_err(&device->dev, "Error installing notify handler\n");
1529                 error = -ENODEV;
1530                 goto err_remove_ec_handler;
1531         }
1532
1533         wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0),
1534                                     NULL, "wmi_bus-%s", dev_name(&device->dev));
1535         if (IS_ERR(wmi_bus_dev)) {
1536                 error = PTR_ERR(wmi_bus_dev);
1537                 goto err_remove_notify_handler;
1538         }
1539         dev_set_drvdata(&device->dev, wmi_bus_dev);
1540
1541         error = parse_wdg(wmi_bus_dev, device);
1542         if (error) {
1543                 pr_err("Failed to parse WDG method\n");
1544                 goto err_remove_busdev;
1545         }
1546
1547         return 0;
1548
1549 err_remove_busdev:
1550         device_unregister(wmi_bus_dev);
1551
1552 err_remove_notify_handler:
1553         acpi_remove_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY,
1554                                    acpi_wmi_notify_handler);
1555
1556 err_remove_ec_handler:
1557         acpi_remove_address_space_handler(acpi_device->handle,
1558                                           ACPI_ADR_SPACE_EC,
1559                                           &acpi_wmi_ec_space_handler);
1560
1561         return error;
1562 }
1563
1564 int __must_check __wmi_driver_register(struct wmi_driver *driver,
1565                                        struct module *owner)
1566 {
1567         driver->driver.owner = owner;
1568         driver->driver.bus = &wmi_bus_type;
1569
1570         return driver_register(&driver->driver);
1571 }
1572 EXPORT_SYMBOL(__wmi_driver_register);
1573
1574 /**
1575  * wmi_driver_unregister() - Unregister a WMI driver
1576  * @driver: WMI driver to unregister
1577  *
1578  * Unregisters a WMI driver from the WMI bus.
1579  */
1580 void wmi_driver_unregister(struct wmi_driver *driver)
1581 {
1582         driver_unregister(&driver->driver);
1583 }
1584 EXPORT_SYMBOL(wmi_driver_unregister);
1585
1586 static struct platform_driver acpi_wmi_driver = {
1587         .driver = {
1588                 .name = "acpi-wmi",
1589                 .acpi_match_table = wmi_device_ids,
1590         },
1591         .probe = acpi_wmi_probe,
1592         .remove_new = acpi_wmi_remove,
1593 };
1594
1595 static int __init acpi_wmi_init(void)
1596 {
1597         int error;
1598
1599         if (acpi_disabled)
1600                 return -ENODEV;
1601
1602         error = class_register(&wmi_bus_class);
1603         if (error)
1604                 return error;
1605
1606         error = bus_register(&wmi_bus_type);
1607         if (error)
1608                 goto err_unreg_class;
1609
1610         error = platform_driver_register(&acpi_wmi_driver);
1611         if (error) {
1612                 pr_err("Error loading mapper\n");
1613                 goto err_unreg_bus;
1614         }
1615
1616         return 0;
1617
1618 err_unreg_bus:
1619         bus_unregister(&wmi_bus_type);
1620
1621 err_unreg_class:
1622         class_unregister(&wmi_bus_class);
1623
1624         return error;
1625 }
1626
1627 static void __exit acpi_wmi_exit(void)
1628 {
1629         platform_driver_unregister(&acpi_wmi_driver);
1630         bus_unregister(&wmi_bus_type);
1631         class_unregister(&wmi_bus_class);
1632 }
1633
1634 subsys_initcall_sync(acpi_wmi_init);
1635 module_exit(acpi_wmi_exit);