drivers/platform/x86/wmi.c

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