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                 /*
 311                  * Ignore whether this WCxx call succeeds or not since
 312                  * the previously executed WQxx method call might have
 313                  * succeeded, and returning the failing status code
 314                  * of this call would throw away the result of the WQxx
 315                  * call, potentially leaking memory.
 316                  */
 317                 acpi_execute_simple_method(handle, wc_method, 0);
 318         }
 319
 320         return status;
 321 }
 322
 323 /**
 324  * wmi_query_block - Return contents of a WMI block (deprecated)
 325  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 326  * @instance: Instance index
 327  * &out: Empty buffer to return the contents of the data block to
 328  *
 329  * Return the contents of an ACPI-WMI data block to a buffer
 330  */
 331 acpi_status wmi_query_block(const char *guid_string, u8 instance,
 332                             struct acpi_buffer *out)
 333 {
 334         struct wmi_block *wblock;
 335
 336         if (!guid_string)
 337                 return AE_BAD_PARAMETER;
 338
 339         if (!find_guid(guid_string, &wblock))
 340                 return AE_ERROR;
 341
 342         return __query_block(wblock, instance, out);
 343 }
 344 EXPORT_SYMBOL_GPL(wmi_query_block);
 345
 346 union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
 347 {
 348         struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
 349         struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
 350
 351         if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
 352                 return NULL;
 353
 354         return (union acpi_object *)out.pointer;
 355 }
 356 EXPORT_SYMBOL_GPL(wmidev_block_query);
 357
 358 struct wmi_device *wmidev_get_other_guid(struct wmi_device *wdev,
 359                                          const char *guid_string)
 360 {
 361         struct wmi_block *this_wb = container_of(wdev, struct wmi_block, dev);
 362         struct wmi_block *other_wb;
 363
 364         if (!find_guid(guid_string, &other_wb))
 365                 return NULL;
 366
 367         if (other_wb->acpi_device != this_wb->acpi_device)
 368                 return NULL;
 369
 370         get_device(&other_wb->dev.dev);
 371         return &other_wb->dev;
 372 }
 373 EXPORT_SYMBOL_GPL(wmidev_get_other_guid);
 374
 375 /**
 376  * wmi_set_block - Write to a WMI block
 377  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 378  * @instance: Instance index
 379  * &in: Buffer containing new values for the data block
 380  *
 381  * Write the contents of the input buffer to an ACPI-WMI data block
 382  */
 383 acpi_status wmi_set_block(const char *guid_string, u8 instance,
 384                           const struct acpi_buffer *in)
 385 {
 386         struct guid_block *block = NULL;
 387         struct wmi_block *wblock = NULL;
 388         acpi_handle handle;
 389         struct acpi_object_list input;
 390         union acpi_object params[2];
 391         char method[5] = "WS";
 392
 393         if (!guid_string || !in)
 394                 return AE_BAD_DATA;
 395
 396         if (!find_guid(guid_string, &wblock))
 397                 return AE_ERROR;
 398
 399         block = &wblock->gblock;
 400         handle = wblock->acpi_device->handle;
 401
 402         if (block->instance_count <= instance)
 403                 return AE_BAD_PARAMETER;
 404
 405         /* Check GUID is a data block */
 406         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 407                 return AE_ERROR;
 408
 409         input.count = 2;
 410         input.pointer = params;
 411         params[0].type = ACPI_TYPE_INTEGER;
 412         params[0].integer.value = instance;
 413
 414         if (block->flags & ACPI_WMI_STRING) {
 415                 params[1].type = ACPI_TYPE_STRING;
 416         } else {
 417                 params[1].type = ACPI_TYPE_BUFFER;
 418         }
 419         params[1].buffer.length = in->length;
 420         params[1].buffer.pointer = in->pointer;
 421
 422         strncat(method, block->object_id, 2);
 423
 424         return acpi_evaluate_object(handle, method, &input, NULL);
 425 }
 426 EXPORT_SYMBOL_GPL(wmi_set_block);
 427
 428 static void wmi_dump_wdg(const struct guid_block *g)
 429 {
 430         pr_info("%pUL:\n", g->guid);
 431         if (g->flags & ACPI_WMI_EVENT)
 432                 pr_info("\tnotify_id: 0x%02X\n", g->notify_id);
 433         else
 434                 pr_info("\tobject_id: %2pE\n", g->object_id);
 435         pr_info("\tinstance_count: %d\n", g->instance_count);
 436         pr_info("\tflags: %#x", g->flags);
 437         if (g->flags) {
 438                 if (g->flags & ACPI_WMI_EXPENSIVE)
 439                         pr_cont(" ACPI_WMI_EXPENSIVE");
 440                 if (g->flags & ACPI_WMI_METHOD)
 441                         pr_cont(" ACPI_WMI_METHOD");
 442                 if (g->flags & ACPI_WMI_STRING)
 443                         pr_cont(" ACPI_WMI_STRING");
 444                 if (g->flags & ACPI_WMI_EVENT)
 445                         pr_cont(" ACPI_WMI_EVENT");
 446         }
 447         pr_cont("\n");
 448
 449 }
 450
 451 static void wmi_notify_debug(u32 value, void *context)
 452 {
 453         struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
 454         union acpi_object *obj;
 455         acpi_status status;
 456
 457         status = wmi_get_event_data(value, &response);
 458         if (status != AE_OK) {
 459                 pr_info("bad event status 0x%x\n", status);
 460                 return;
 461         }
 462
 463         obj = (union acpi_object *)response.pointer;
 464
 465         if (!obj)
 466                 return;
 467
 468         pr_info("DEBUG Event ");
 469         switch(obj->type) {
 470         case ACPI_TYPE_BUFFER:
 471                 pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
 472                 break;
 473         case ACPI_TYPE_STRING:
 474                 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
 475                 break;
 476         case ACPI_TYPE_INTEGER:
 477                 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
 478                 break;
 479         case ACPI_TYPE_PACKAGE:
 480                 pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
 481                 break;
 482         default:
 483                 pr_cont("object type 0x%X\n", obj->type);
 484         }
 485         kfree(obj);
 486 }
 487
 488 /**
 489  * wmi_install_notify_handler - Register handler for WMI events
 490  * @handler: Function to handle notifications
 491  * @data: Data to be returned to handler when event is fired
 492  *
 493  * Register a handler for events sent to the ACPI-WMI mapper device.
 494  */
 495 acpi_status wmi_install_notify_handler(const char *guid,
 496 wmi_notify_handler handler, void *data)
 497 {
 498         struct wmi_block *block;
 499         acpi_status status = AE_NOT_EXIST;
 500         uuid_le guid_input;
 501         struct list_head *p;
 502
 503         if (!guid || !handler)
 504                 return AE_BAD_PARAMETER;
 505
 506         if (uuid_le_to_bin(guid, &guid_input))
 507                 return AE_BAD_PARAMETER;
 508
 509         list_for_each(p, &wmi_block_list) {
 510                 acpi_status wmi_status;
 511                 block = list_entry(p, struct wmi_block, list);
 512
 513                 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
 514                         if (block->handler &&
 515                             block->handler != wmi_notify_debug)
 516                                 return AE_ALREADY_ACQUIRED;
 517
 518                         block->handler = handler;
 519                         block->handler_data = data;
 520
 521                         wmi_status = wmi_method_enable(block, 1);
 522                         if ((wmi_status != AE_OK) ||
 523                             ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
 524                                 status = wmi_status;
 525                 }
 526         }
 527
 528         return status;
 529 }
 530 EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
 531
 532 /**
 533  * wmi_uninstall_notify_handler - Unregister handler for WMI events
 534  *
 535  * Unregister handler for events sent to the ACPI-WMI mapper device.
 536  */
 537 acpi_status wmi_remove_notify_handler(const char *guid)
 538 {
 539         struct wmi_block *block;
 540         acpi_status status = AE_NOT_EXIST;
 541         uuid_le guid_input;
 542         struct list_head *p;
 543
 544         if (!guid)
 545                 return AE_BAD_PARAMETER;
 546
 547         if (uuid_le_to_bin(guid, &guid_input))
 548                 return AE_BAD_PARAMETER;
 549
 550         list_for_each(p, &wmi_block_list) {
 551                 acpi_status wmi_status;
 552                 block = list_entry(p, struct wmi_block, list);
 553
 554                 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
 555                         if (!block->handler ||
 556                             block->handler == wmi_notify_debug)
 557                                 return AE_NULL_ENTRY;
 558
 559                         if (debug_event) {
 560                                 block->handler = wmi_notify_debug;
 561                                 status = AE_OK;
 562                         } else {
 563                                 wmi_status = wmi_method_enable(block, 0);
 564                                 block->handler = NULL;
 565                                 block->handler_data = NULL;
 566                                 if ((wmi_status != AE_OK) ||
 567                                     ((wmi_status == AE_OK) &&
 568                                      (status == AE_NOT_EXIST)))
 569                                         status = wmi_status;
 570                         }
 571                 }
 572         }
 573
 574         return status;
 575 }
 576 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
 577
 578 /**
 579  * wmi_get_event_data - Get WMI data associated with an event
 580  *
 581  * @event: Event to find
 582  * @out: Buffer to hold event data. out->pointer should be freed with kfree()
 583  *
 584  * Returns extra data associated with an event in WMI.
 585  */
 586 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
 587 {
 588         struct acpi_object_list input;
 589         union acpi_object params[1];
 590         struct guid_block *gblock;
 591         struct wmi_block *wblock;
 592         struct list_head *p;
 593
 594         input.count = 1;
 595         input.pointer = params;
 596         params[0].type = ACPI_TYPE_INTEGER;
 597         params[0].integer.value = event;
 598
 599         list_for_each(p, &wmi_block_list) {
 600                 wblock = list_entry(p, struct wmi_block, list);
 601                 gblock = &wblock->gblock;
 602
 603                 if ((gblock->flags & ACPI_WMI_EVENT) &&
 604                         (gblock->notify_id == event))
 605                         return acpi_evaluate_object(wblock->acpi_device->handle,
 606                                 "_WED", &input, out);
 607         }
 608
 609         return AE_NOT_FOUND;
 610 }
 611 EXPORT_SYMBOL_GPL(wmi_get_event_data);
 612
 613 /**
 614  * wmi_has_guid - Check if a GUID is available
 615  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 616  *
 617  * Check if a given GUID is defined by _WDG
 618  */
 619 bool wmi_has_guid(const char *guid_string)
 620 {
 621         return find_guid(guid_string, NULL);
 622 }
 623 EXPORT_SYMBOL_GPL(wmi_has_guid);
 624
 625 static struct wmi_block *dev_to_wblock(struct device *dev)
 626 {
 627         return container_of(dev, struct wmi_block, dev.dev);
 628 }
 629
 630 static struct wmi_device *dev_to_wdev(struct device *dev)
 631 {
 632         return container_of(dev, struct wmi_device, dev);
 633 }
 634
 635 /*
 636  * sysfs interface
 637  */
 638 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 639                              char *buf)
 640 {
 641         struct wmi_block *wblock = dev_to_wblock(dev);
 642
 643         return sprintf(buf, "wmi:%pUL\n", wblock->gblock.guid);
 644 }
 645 static DEVICE_ATTR_RO(modalias);
 646
 647 static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
 648                          char *buf)
 649 {
 650         struct wmi_block *wblock = dev_to_wblock(dev);
 651
 652         return sprintf(buf, "%pUL\n", wblock->gblock.guid);
 653 }
 654 static DEVICE_ATTR_RO(guid);
 655
 656 static ssize_t instance_count_show(struct device *dev,
 657                                    struct device_attribute *attr, char *buf)
 658 {
 659         struct wmi_block *wblock = dev_to_wblock(dev);
 660
 661         return sprintf(buf, "%d\n", (int)wblock->gblock.instance_count);
 662 }
 663 static DEVICE_ATTR_RO(instance_count);
 664
 665 static ssize_t expensive_show(struct device *dev,
 666                               struct device_attribute *attr, char *buf)
 667 {
 668         struct wmi_block *wblock = dev_to_wblock(dev);
 669
 670         return sprintf(buf, "%d\n",
 671                        (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
 672 }
 673 static DEVICE_ATTR_RO(expensive);
 674
 675 static struct attribute *wmi_attrs[] = {
 676         &dev_attr_modalias.attr,
 677         &dev_attr_guid.attr,
 678         &dev_attr_instance_count.attr,
 679         &dev_attr_expensive.attr,
 680         NULL,
 681 };
 682 ATTRIBUTE_GROUPS(wmi);
 683
 684 static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
 685                               char *buf)
 686 {
 687         struct wmi_block *wblock = dev_to_wblock(dev);
 688
 689         return sprintf(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
 690 }
 691 static DEVICE_ATTR_RO(notify_id);
 692
 693 static struct attribute *wmi_event_attrs[] = {
 694         &dev_attr_notify_id.attr,
 695         NULL,
 696 };
 697 ATTRIBUTE_GROUPS(wmi_event);
 698
 699 static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
 700                               char *buf)
 701 {
 702         struct wmi_block *wblock = dev_to_wblock(dev);
 703
 704         return sprintf(buf, "%c%c\n", wblock->gblock.object_id[0],
 705                        wblock->gblock.object_id[1]);
 706 }
 707 static DEVICE_ATTR_RO(object_id);
 708
 709 static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
 710                             char *buf)
 711 {
 712         struct wmi_device *wdev = dev_to_wdev(dev);
 713
 714         return sprintf(buf, "%d\n", (int)wdev->setable);
 715 }
 716 static DEVICE_ATTR_RO(setable);
 717
 718 static struct attribute *wmi_data_attrs[] = {
 719         &dev_attr_object_id.attr,
 720         &dev_attr_setable.attr,
 721         NULL,
 722 };
 723 ATTRIBUTE_GROUPS(wmi_data);
 724
 725 static struct attribute *wmi_method_attrs[] = {
 726         &dev_attr_object_id.attr,
 727         NULL,
 728 };
 729 ATTRIBUTE_GROUPS(wmi_method);
 730
 731 static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 732 {
 733         struct wmi_block *wblock = dev_to_wblock(dev);
 734
 735         if (add_uevent_var(env, "MODALIAS=wmi:%pUL", wblock->gblock.guid))
 736                 return -ENOMEM;
 737
 738         if (add_uevent_var(env, "WMI_GUID=%pUL", wblock->gblock.guid))
 739                 return -ENOMEM;
 740
 741         return 0;
 742 }
 743
 744 static void wmi_dev_release(struct device *dev)
 745 {
 746         struct wmi_block *wblock = dev_to_wblock(dev);
 747
 748         kfree(wblock);
 749 }
 750
 751 static int wmi_dev_match(struct device *dev, struct device_driver *driver)
 752 {
 753         struct wmi_driver *wmi_driver =
 754                 container_of(driver, struct wmi_driver, driver);
 755         struct wmi_block *wblock = dev_to_wblock(dev);
 756         const struct wmi_device_id *id = wmi_driver->id_table;
 757
 758         if (id == NULL)
 759                 return 0;
 760
 761         while (id->guid_string) {
 762                 uuid_le driver_guid;
 763
 764                 if (WARN_ON(uuid_le_to_bin(id->guid_string, &driver_guid)))
 765                         continue;
 766                 if (!memcmp(&driver_guid, wblock->gblock.guid, 16))
 767                         return 1;
 768
 769                 id++;
 770         }
 771
 772         return 0;
 773 }
 774
 775 static int wmi_dev_probe(struct device *dev)
 776 {
 777         struct wmi_block *wblock = dev_to_wblock(dev);
 778         struct wmi_driver *wdriver =
 779                 container_of(dev->driver, struct wmi_driver, driver);
 780         int ret = 0;
 781
 782         if (ACPI_FAILURE(wmi_method_enable(wblock, 1)))
 783                 dev_warn(dev, "failed to enable device -- probing anyway\n");
 784
 785         if (wdriver->probe) {
 786                 ret = wdriver->probe(dev_to_wdev(dev));
 787                 if (ret != 0 && ACPI_FAILURE(wmi_method_enable(wblock, 0)))
 788                         dev_warn(dev, "failed to disable device\n");
 789         }
 790
 791         return ret;
 792 }
 793
 794 static int wmi_dev_remove(struct device *dev)
 795 {
 796         struct wmi_block *wblock = dev_to_wblock(dev);
 797         struct wmi_driver *wdriver =
 798                 container_of(dev->driver, struct wmi_driver, driver);
 799         int ret = 0;
 800
 801         if (wdriver->remove)
 802                 ret = wdriver->remove(dev_to_wdev(dev));
 803
 804         if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
 805                 dev_warn(dev, "failed to disable device\n");
 806
 807         return ret;
 808 }
 809
 810 static struct class wmi_bus_class = {
 811         .name = "wmi_bus",
 812 };
 813
 814 static struct bus_type wmi_bus_type = {
 815         .name = "wmi",
 816         .dev_groups = wmi_groups,
 817         .match = wmi_dev_match,
 818         .uevent = wmi_dev_uevent,
 819         .probe = wmi_dev_probe,
 820         .remove = wmi_dev_remove,
 821 };
 822
 823 static struct device_type wmi_type_event = {
 824         .name = "event",
 825         .groups = wmi_event_groups,
 826         .release = wmi_dev_release,
 827 };
 828
 829 static struct device_type wmi_type_method = {
 830         .name = "method",
 831         .groups = wmi_method_groups,
 832         .release = wmi_dev_release,
 833 };
 834
 835 static struct device_type wmi_type_data = {
 836         .name = "data",
 837         .groups = wmi_data_groups,
 838         .release = wmi_dev_release,
 839 };
 840
 841 static int wmi_create_device(struct device *wmi_bus_dev,
 842                              const struct guid_block *gblock,
 843                              struct wmi_block *wblock,
 844                              struct acpi_device *device)
 845 {
 846         struct acpi_device_info *info;
 847         char method[5];
 848         int result;
 849
 850         if (gblock->flags & ACPI_WMI_EVENT) {
 851                 wblock->dev.dev.type = &wmi_type_event;
 852                 goto out_init;
 853         }
 854
 855         if (gblock->flags & ACPI_WMI_METHOD) {
 856                 wblock->dev.dev.type = &wmi_type_method;
 857                 goto out_init;
 858         }
 859
 860         /*
 861          * Data Block Query Control Method (WQxx by convention) is
 862          * required per the WMI documentation. If it is not present,
 863          * we ignore this data block.
 864          */
 865         strcpy(method, "WQ");
 866         strncat(method, wblock->gblock.object_id, 2);
 867         result = get_subobj_info(device->handle, method, &info);
 868
 869         if (result) {
 870                 dev_warn(wmi_bus_dev,
 871                          "%s data block query control method not found",
 872                          method);
 873                 return result;
 874         }
 875
 876         wblock->dev.dev.type = &wmi_type_data;
 877
 878         /*
 879          * The Microsoft documentation specifically states:
 880          *
 881          *   Data blocks registered with only a single instance
 882          *   can ignore the parameter.
 883          *
 884          * ACPICA will get mad at us if we call the method with the wrong number
 885          * of arguments, so check what our method expects.  (On some Dell
 886          * laptops, WQxx may not be a method at all.)
 887          */
 888         if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
 889                 wblock->read_takes_no_args = true;
 890
 891         kfree(info);
 892
 893         strcpy(method, "WS");
 894         strncat(method, wblock->gblock.object_id, 2);
 895         result = get_subobj_info(device->handle, method, NULL);
 896
 897         if (result == 0)
 898                 wblock->dev.setable = true;
 899
 900  out_init:
 901         wblock->dev.dev.bus = &wmi_bus_type;
 902         wblock->dev.dev.parent = wmi_bus_dev;
 903
 904         dev_set_name(&wblock->dev.dev, "%pUL", gblock->guid);
 905
 906         device_initialize(&wblock->dev.dev);
 907
 908         return 0;
 909 }
 910
 911 static void wmi_free_devices(struct acpi_device *device)
 912 {
 913         struct wmi_block *wblock, *next;
 914
 915         /* Delete devices for all the GUIDs */
 916         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
 917                 if (wblock->acpi_device == device) {
 918                         list_del(&wblock->list);
 919                         device_unregister(&wblock->dev.dev);
 920                 }
 921         }
 922 }
 923
 924 static bool guid_already_parsed(struct acpi_device *device,
 925                                 const u8 *guid)
 926 {
 927         struct wmi_block *wblock;
 928
 929         list_for_each_entry(wblock, &wmi_block_list, list) {
 930                 if (memcmp(wblock->gblock.guid, guid, 16) == 0) {
 931                         /*
 932                          * Because we historically didn't track the relationship
 933                          * between GUIDs and ACPI nodes, we don't know whether
 934                          * we need to suppress GUIDs that are unique on a
 935                          * given node but duplicated across nodes.
 936                          */
 937                         dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
 938                                  guid, dev_name(&wblock->acpi_device->dev));
 939                         return true;
 940                 }
 941         }
 942
 943         return false;
 944 }
 945
 946 /*
 947  * Parse the _WDG method for the GUID data blocks
 948  */
 949 static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
 950 {
 951         struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
 952         const struct guid_block *gblock;
 953         struct wmi_block *wblock, *next;
 954         union acpi_object *obj;
 955         acpi_status status;
 956         int retval = 0;
 957         u32 i, total;
 958
 959         status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
 960         if (ACPI_FAILURE(status))
 961                 return -ENXIO;
 962
 963         obj = (union acpi_object *) out.pointer;
 964         if (!obj)
 965                 return -ENXIO;
 966
 967         if (obj->type != ACPI_TYPE_BUFFER) {
 968                 retval = -ENXIO;
 969                 goto out_free_pointer;
 970         }
 971
 972         gblock = (const struct guid_block *)obj->buffer.pointer;
 973         total = obj->buffer.length / sizeof(struct guid_block);
 974
 975         for (i = 0; i < total; i++) {
 976                 if (debug_dump_wdg)
 977                         wmi_dump_wdg(&gblock[i]);
 978
 979                 /*
 980                  * Some WMI devices, like those for nVidia hooks, have a
 981                  * duplicate GUID. It's not clear what we should do in this
 982                  * case yet, so for now, we'll just ignore the duplicate
 983                  * for device creation.
 984                  */
 985                 if (guid_already_parsed(device, gblock[i].guid))
 986                         continue;
 987
 988                 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
 989                 if (!wblock) {
 990                         retval = -ENOMEM;
 991                         break;
 992                 }
 993
 994                 wblock->acpi_device = device;
 995                 wblock->gblock = gblock[i];
 996
 997                 retval = wmi_create_device(wmi_bus_dev, &gblock[i], wblock, device);
 998                 if (retval) {
 999                         kfree(wblock);
1000                         continue;
1001                 }
1002
1003                 list_add_tail(&wblock->list, &wmi_block_list);
1004
1005                 if (debug_event) {
1006                         wblock->handler = wmi_notify_debug;
1007                         wmi_method_enable(wblock, 1);
1008                 }
1009         }
1010
1011         /*
1012          * Now that all of the devices are created, add them to the
1013          * device tree and probe subdrivers.
1014          */
1015         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1016                 if (wblock->acpi_device != device)
1017                         continue;
1018
1019                 retval = device_add(&wblock->dev.dev);
1020                 if (retval) {
1021                         dev_err(wmi_bus_dev, "failed to register %pULL\n",
1022                                 wblock->gblock.guid);
1023                         if (debug_event)
1024                                 wmi_method_enable(wblock, 0);
1025                         list_del(&wblock->list);
1026                         put_device(&wblock->dev.dev);
1027                 }
1028         }
1029
1030 out_free_pointer:
1031         kfree(out.pointer);
1032         return retval;
1033 }
1034
1035 /*
1036  * WMI can have EmbeddedControl access regions. In which case, we just want to
1037  * hand these off to the EC driver.
1038  */
1039 static acpi_status
1040 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1041                       u32 bits, u64 *value,
1042                       void *handler_context, void *region_context)
1043 {
1044         int result = 0, i = 0;
1045         u8 temp = 0;
1046
1047         if ((address > 0xFF) || !value)
1048                 return AE_BAD_PARAMETER;
1049
1050         if (function != ACPI_READ && function != ACPI_WRITE)
1051                 return AE_BAD_PARAMETER;
1052
1053         if (bits != 8)
1054                 return AE_BAD_PARAMETER;
1055
1056         if (function == ACPI_READ) {
1057                 result = ec_read(address, &temp);
1058                 (*value) |= ((u64)temp) << i;
1059         } else {
1060                 temp = 0xff & ((*value) >> i);
1061                 result = ec_write(address, temp);
1062         }
1063
1064         switch (result) {
1065         case -EINVAL:
1066                 return AE_BAD_PARAMETER;
1067                 break;
1068         case -ENODEV:
1069                 return AE_NOT_FOUND;
1070                 break;
1071         case -ETIME:
1072                 return AE_TIME;
1073                 break;
1074         default:
1075                 return AE_OK;
1076         }
1077 }
1078
1079 static void acpi_wmi_notify_handler(acpi_handle handle, u32 event,
1080                                     void *context)
1081 {
1082         struct guid_block *block;
1083         struct wmi_block *wblock;
1084         struct list_head *p;
1085         bool found_it = false;
1086
1087         list_for_each(p, &wmi_block_list) {
1088                 wblock = list_entry(p, struct wmi_block, list);
1089                 block = &wblock->gblock;
1090
1091                 if (wblock->acpi_device->handle == handle &&
1092                     (block->flags & ACPI_WMI_EVENT) &&
1093                     (block->notify_id == event))
1094                 {
1095                         found_it = true;
1096                         break;
1097                 }
1098         }
1099
1100         if (!found_it)
1101                 return;
1102
1103         /* If a driver is bound, then notify the driver. */
1104         if (wblock->dev.dev.driver) {
1105                 struct wmi_driver *driver;
1106                 struct acpi_object_list input;
1107                 union acpi_object params[1];
1108                 struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL };
1109                 acpi_status status;
1110
1111                 driver = container_of(wblock->dev.dev.driver,
1112                                       struct wmi_driver, driver);
1113
1114                 input.count = 1;
1115                 input.pointer = params;
1116                 params[0].type = ACPI_TYPE_INTEGER;
1117                 params[0].integer.value = event;
1118
1119                 status = acpi_evaluate_object(wblock->acpi_device->handle,
1120                                               "_WED", &input, &evdata);
1121                 if (ACPI_FAILURE(status)) {
1122                         dev_warn(&wblock->dev.dev,
1123                                  "failed to get event data\n");
1124                         return;
1125                 }
1126
1127                 if (driver->notify)
1128                         driver->notify(&wblock->dev,
1129                                        (union acpi_object *)evdata.pointer);
1130
1131                 kfree(evdata.pointer);
1132         } else if (wblock->handler) {
1133                 /* Legacy handler */
1134                 wblock->handler(event, wblock->handler_data);
1135         }
1136
1137         if (debug_event) {
1138                 pr_info("DEBUG Event GUID: %pUL\n",
1139                         wblock->gblock.guid);
1140         }
1141
1142         acpi_bus_generate_netlink_event(
1143                 wblock->acpi_device->pnp.device_class,
1144                 dev_name(&wblock->dev.dev),
1145                 event, 0);
1146
1147 }
1148
1149 static int acpi_wmi_remove(struct platform_device *device)
1150 {
1151         struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev);
1152
1153         acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1154                                    acpi_wmi_notify_handler);
1155         acpi_remove_address_space_handler(acpi_device->handle,
1156                                 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
1157         wmi_free_devices(acpi_device);
1158         device_unregister((struct device *)dev_get_drvdata(&device->dev));
1159
1160         return 0;
1161 }
1162
1163 static int acpi_wmi_probe(struct platform_device *device)
1164 {
1165         struct acpi_device *acpi_device;
1166         struct device *wmi_bus_dev;
1167         acpi_status status;
1168         int error;
1169
1170         acpi_device = ACPI_COMPANION(&device->dev);
1171         if (!acpi_device) {
1172                 dev_err(&device->dev, "ACPI companion is missing\n");
1173                 return -ENODEV;
1174         }
1175
1176         status = acpi_install_address_space_handler(acpi_device->handle,
1177                                                     ACPI_ADR_SPACE_EC,
1178                                                     &acpi_wmi_ec_space_handler,
1179                                                     NULL, NULL);
1180         if (ACPI_FAILURE(status)) {
1181                 dev_err(&device->dev, "Error installing EC region handler\n");
1182                 return -ENODEV;
1183         }
1184
1185         status = acpi_install_notify_handler(acpi_device->handle,
1186                                              ACPI_DEVICE_NOTIFY,
1187                                              acpi_wmi_notify_handler,
1188                                              NULL);
1189         if (ACPI_FAILURE(status)) {
1190                 dev_err(&device->dev, "Error installing notify handler\n");
1191                 error = -ENODEV;
1192                 goto err_remove_ec_handler;
1193         }
1194
1195         wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0),
1196                                     NULL, "wmi_bus-%s", dev_name(&device->dev));
1197         if (IS_ERR(wmi_bus_dev)) {
1198                 error = PTR_ERR(wmi_bus_dev);
1199                 goto err_remove_notify_handler;
1200         }
1201         dev_set_drvdata(&device->dev, wmi_bus_dev);
1202
1203         error = parse_wdg(wmi_bus_dev, acpi_device);
1204         if (error) {
1205                 pr_err("Failed to parse WDG method\n");
1206                 goto err_remove_busdev;
1207         }
1208
1209         return 0;
1210
1211 err_remove_busdev:
1212         device_unregister(wmi_bus_dev);
1213
1214 err_remove_notify_handler:
1215         acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1216                                    acpi_wmi_notify_handler);
1217
1218 err_remove_ec_handler:
1219         acpi_remove_address_space_handler(acpi_device->handle,
1220                                           ACPI_ADR_SPACE_EC,
1221                                           &acpi_wmi_ec_space_handler);
1222
1223         return error;
1224 }
1225
1226 int __must_check __wmi_driver_register(struct wmi_driver *driver,
1227                                        struct module *owner)
1228 {
1229         driver->driver.owner = owner;
1230         driver->driver.bus = &wmi_bus_type;
1231
1232         return driver_register(&driver->driver);
1233 }
1234 EXPORT_SYMBOL(__wmi_driver_register);
1235
1236 void wmi_driver_unregister(struct wmi_driver *driver)
1237 {
1238         driver_unregister(&driver->driver);
1239 }
1240 EXPORT_SYMBOL(wmi_driver_unregister);
1241
1242 static int __init acpi_wmi_init(void)
1243 {
1244         int error;
1245
1246         if (acpi_disabled)
1247                 return -ENODEV;
1248
1249         error = class_register(&wmi_bus_class);
1250         if (error)
1251                 return error;
1252
1253         error = bus_register(&wmi_bus_type);
1254         if (error)
1255                 goto err_unreg_class;
1256
1257         error = platform_driver_register(&acpi_wmi_driver);
1258         if (error) {
1259                 pr_err("Error loading mapper\n");
1260                 goto err_unreg_bus;
1261         }
1262
1263         return 0;
1264
1265 err_unreg_bus:
1266         bus_unregister(&wmi_bus_type);
1267
1268 err_unreg_class:
1269         class_unregister(&wmi_bus_class);
1270
1271         return error;
1272 }
1273
1274 static void __exit acpi_wmi_exit(void)
1275 {
1276         platform_driver_unregister(&acpi_wmi_driver);
1277         class_unregister(&wmi_bus_class);
1278         bus_unregister(&wmi_bus_type);
1279 }
1280
1281 subsys_initcall_sync(acpi_wmi_init);
1282 module_exit(acpi_wmi_exit);