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