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  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  12  *
  13  *  This program is free software; you can redistribute it and/or modify
  14  *  it under the terms of the GNU General Public License as published by
  15  *  the Free Software Foundation; either version 2 of the License, or (at
  16  *  your option) any later version.
  17  *
  18  *  This program is distributed in the hope that it will be useful, but
  19  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  20  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  21  *  General Public License for more details.
  22  *
  23  *  You should have received a copy of the GNU General Public License along
  24  *  with this program; if not, write to the Free Software Foundation, Inc.,
  25  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  26  *
  27  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  28  */
  29
  30 #define pr_fmt(fmt)     KBUILD_MODNAME ": " fmt
  31
  32 #include <linux/kernel.h>
  33 #include <linux/init.h>
  34 #include <linux/types.h>
  35 #include <linux/device.h>
  36 #include <linux/list.h>
  37 #include <linux/acpi.h>
  38 #include <linux/slab.h>
  39 #include <linux/module.h>
  40
  41 ACPI_MODULE_NAME("wmi");
  42 MODULE_AUTHOR("Carlos Corbacho");
  43 MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
  44 MODULE_LICENSE("GPL");
  45
  46 #define ACPI_WMI_CLASS "wmi"
  47
  48 static DEFINE_MUTEX(wmi_data_lock);
  49 static LIST_HEAD(wmi_block_list);
  50
  51 struct guid_block {
  52         char guid[16];
  53         union {
  54                 char object_id[2];
  55                 struct {
  56                         unsigned char notify_id;
  57                         unsigned char reserved;
  58                 };
  59         };
  60         u8 instance_count;
  61         u8 flags;
  62 };
  63
  64 struct wmi_block {
  65         struct list_head list;
  66         struct guid_block gblock;
  67         acpi_handle handle;
  68         wmi_notify_handler handler;
  69         void *handler_data;
  70         struct device dev;
  71 };
  72
  73
  74 /*
  75  * If the GUID data block is marked as expensive, we must enable and
  76  * explicitily disable data collection.
  77  */
  78 #define ACPI_WMI_EXPENSIVE   0x1
  79 #define ACPI_WMI_METHOD      0x2        /* GUID is a method */
  80 #define ACPI_WMI_STRING      0x4        /* GUID takes & returns a string */
  81 #define ACPI_WMI_EVENT       0x8        /* GUID is an event */
  82
  83 static bool debug_event;
  84 module_param(debug_event, bool, 0444);
  85 MODULE_PARM_DESC(debug_event,
  86                  "Log WMI Events [0/1]");
  87
  88 static bool debug_dump_wdg;
  89 module_param(debug_dump_wdg, bool, 0444);
  90 MODULE_PARM_DESC(debug_dump_wdg,
  91                  "Dump available WMI interfaces [0/1]");
  92
  93 static int acpi_wmi_remove(struct acpi_device *device);
  94 static int acpi_wmi_add(struct acpi_device *device);
  95 static void acpi_wmi_notify(struct acpi_device *device, u32 event);
  96
  97 static const struct acpi_device_id wmi_device_ids[] = {
  98         {"PNP0C14", 0},
  99         {"pnp0c14", 0},
 100         {"", 0},
 101 };
 102 MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
 103
 104 static struct acpi_driver acpi_wmi_driver = {
 105         .name = "wmi",
 106         .class = ACPI_WMI_CLASS,
 107         .ids = wmi_device_ids,
 108         .ops = {
 109                 .add = acpi_wmi_add,
 110                 .remove = acpi_wmi_remove,
 111                 .notify = acpi_wmi_notify,
 112         },
 113 };
 114
 115 /*
 116  * GUID parsing functions
 117  */
 118
 119 /**
 120  * wmi_parse_hexbyte - Convert a ASCII hex number to a byte
 121  * @src:  Pointer to at least 2 characters to convert.
 122  *
 123  * Convert a two character ASCII hex string to a number.
 124  *
 125  * Return:  0-255  Success, the byte was parsed correctly
 126  *          -1     Error, an invalid character was supplied
 127  */
 128 static int wmi_parse_hexbyte(const u8 *src)
 129 {
 130         int h;
 131         int value;
 132
 133         /* high part */
 134         h = value = hex_to_bin(src[0]);
 135         if (value < 0)
 136                 return -1;
 137
 138         /* low part */
 139         value = hex_to_bin(src[1]);
 140         if (value >= 0)
 141                 return (h << 4) | value;
 142         return -1;
 143 }
 144
 145 /**
 146  * wmi_swap_bytes - Rearrange GUID bytes to match GUID binary
 147  * @src:   Memory block holding binary GUID (16 bytes)
 148  * @dest:  Memory block to hold byte swapped binary GUID (16 bytes)
 149  *
 150  * Byte swap a binary GUID to match it's real GUID value
 151  */
 152 static void wmi_swap_bytes(u8 *src, u8 *dest)
 153 {
 154         int i;
 155
 156         for (i = 0; i <= 3; i++)
 157                 memcpy(dest + i, src + (3 - i), 1);
 158
 159         for (i = 0; i <= 1; i++)
 160                 memcpy(dest + 4 + i, src + (5 - i), 1);
 161
 162         for (i = 0; i <= 1; i++)
 163                 memcpy(dest + 6 + i, src + (7 - i), 1);
 164
 165         memcpy(dest + 8, src + 8, 8);
 166 }
 167
 168 /**
 169  * wmi_parse_guid - Convert GUID from ASCII to binary
 170  * @src:   36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 171  * @dest:  Memory block to hold binary GUID (16 bytes)
 172  *
 173  * N.B. The GUID need not be NULL terminated.
 174  *
 175  * Return:  'true'   @dest contains binary GUID
 176  *          'false'  @dest contents are undefined
 177  */
 178 static bool wmi_parse_guid(const u8 *src, u8 *dest)
 179 {
 180         static const int size[] = { 4, 2, 2, 2, 6 };
 181         int i, j, v;
 182
 183         if (src[8]  != '-' || src[13] != '-' ||
 184                 src[18] != '-' || src[23] != '-')
 185                 return false;
 186
 187         for (j = 0; j < 5; j++, src++) {
 188                 for (i = 0; i < size[j]; i++, src += 2, *dest++ = v) {
 189                         v = wmi_parse_hexbyte(src);
 190                         if (v < 0)
 191                                 return false;
 192                 }
 193         }
 194
 195         return true;
 196 }
 197
 198 /*
 199  * Convert a raw GUID to the ACII string representation
 200  */
 201 static int wmi_gtoa(const char *in, char *out)
 202 {
 203         int i;
 204
 205         for (i = 3; i >= 0; i--)
 206                 out += sprintf(out, "%02X", in[i] & 0xFF);
 207
 208         out += sprintf(out, "-");
 209         out += sprintf(out, "%02X", in[5] & 0xFF);
 210         out += sprintf(out, "%02X", in[4] & 0xFF);
 211         out += sprintf(out, "-");
 212         out += sprintf(out, "%02X", in[7] & 0xFF);
 213         out += sprintf(out, "%02X", in[6] & 0xFF);
 214         out += sprintf(out, "-");
 215         out += sprintf(out, "%02X", in[8] & 0xFF);
 216         out += sprintf(out, "%02X", in[9] & 0xFF);
 217         out += sprintf(out, "-");
 218
 219         for (i = 10; i <= 15; i++)
 220                 out += sprintf(out, "%02X", in[i] & 0xFF);
 221
 222         *out = '\0';
 223         return 0;
 224 }
 225
 226 static bool find_guid(const char *guid_string, struct wmi_block **out)
 227 {
 228         char tmp[16], guid_input[16];
 229         struct wmi_block *wblock;
 230         struct guid_block *block;
 231         struct list_head *p;
 232
 233         wmi_parse_guid(guid_string, tmp);
 234         wmi_swap_bytes(tmp, guid_input);
 235
 236         list_for_each(p, &wmi_block_list) {
 237                 wblock = list_entry(p, struct wmi_block, list);
 238                 block = &wblock->gblock;
 239
 240                 if (memcmp(block->guid, guid_input, 16) == 0) {
 241                         if (out)
 242                                 *out = wblock;
 243                         return 1;
 244                 }
 245         }
 246         return 0;
 247 }
 248
 249 static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable)
 250 {
 251         struct guid_block *block = NULL;
 252         char method[5];
 253         acpi_status status;
 254         acpi_handle handle;
 255
 256         block = &wblock->gblock;
 257         handle = wblock->handle;
 258
 259         snprintf(method, 5, "WE%02X", block->notify_id);
 260         status = acpi_execute_simple_method(handle, method, enable);
 261
 262         if (status != AE_OK && status != AE_NOT_FOUND)
 263                 return status;
 264         else
 265                 return AE_OK;
 266 }
 267
 268 /*
 269  * Exported WMI functions
 270  */
 271 /**
 272  * wmi_evaluate_method - Evaluate a WMI method
 273  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 274  * @instance: Instance index
 275  * @method_id: Method ID to call
 276  * &in: Buffer containing input for the method call
 277  * &out: Empty buffer to return the method results
 278  *
 279  * Call an ACPI-WMI method
 280  */
 281 acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
 282 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
 283 {
 284         struct guid_block *block = NULL;
 285         struct wmi_block *wblock = NULL;
 286         acpi_handle handle;
 287         acpi_status status;
 288         struct acpi_object_list input;
 289         union acpi_object params[3];
 290         char method[5] = "WM";
 291
 292         if (!find_guid(guid_string, &wblock))
 293                 return AE_ERROR;
 294
 295         block = &wblock->gblock;
 296         handle = wblock->handle;
 297
 298         if (!(block->flags & ACPI_WMI_METHOD))
 299                 return AE_BAD_DATA;
 300
 301         if (block->instance_count < instance)
 302                 return AE_BAD_PARAMETER;
 303
 304         input.count = 2;
 305         input.pointer = params;
 306         params[0].type = ACPI_TYPE_INTEGER;
 307         params[0].integer.value = instance;
 308         params[1].type = ACPI_TYPE_INTEGER;
 309         params[1].integer.value = method_id;
 310
 311         if (in) {
 312                 input.count = 3;
 313
 314                 if (block->flags & ACPI_WMI_STRING) {
 315                         params[2].type = ACPI_TYPE_STRING;
 316                 } else {
 317                         params[2].type = ACPI_TYPE_BUFFER;
 318                 }
 319                 params[2].buffer.length = in->length;
 320                 params[2].buffer.pointer = in->pointer;
 321         }
 322
 323         strncat(method, block->object_id, 2);
 324
 325         status = acpi_evaluate_object(handle, method, &input, out);
 326
 327         return status;
 328 }
 329 EXPORT_SYMBOL_GPL(wmi_evaluate_method);
 330
 331 /**
 332  * wmi_query_block - Return contents of a WMI block
 333  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 334  * @instance: Instance index
 335  * &out: Empty buffer to return the contents of the data block to
 336  *
 337  * Return the contents of an ACPI-WMI data block to a buffer
 338  */
 339 acpi_status wmi_query_block(const char *guid_string, u8 instance,
 340 struct acpi_buffer *out)
 341 {
 342         struct guid_block *block = NULL;
 343         struct wmi_block *wblock = NULL;
 344         acpi_handle handle;
 345         acpi_status status, wc_status = AE_ERROR;
 346         struct acpi_object_list input;
 347         union acpi_object wq_params[1];
 348         char method[5];
 349         char wc_method[5] = "WC";
 350
 351         if (!guid_string || !out)
 352                 return AE_BAD_PARAMETER;
 353
 354         if (!find_guid(guid_string, &wblock))
 355                 return AE_ERROR;
 356
 357         block = &wblock->gblock;
 358         handle = wblock->handle;
 359
 360         if (block->instance_count < instance)
 361                 return AE_BAD_PARAMETER;
 362
 363         /* Check GUID is a data block */
 364         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 365                 return AE_ERROR;
 366
 367         input.count = 1;
 368         input.pointer = wq_params;
 369         wq_params[0].type = ACPI_TYPE_INTEGER;
 370         wq_params[0].integer.value = instance;
 371
 372         /*
 373          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
 374          * enable collection.
 375          */
 376         if (block->flags & ACPI_WMI_EXPENSIVE) {
 377                 strncat(wc_method, block->object_id, 2);
 378
 379                 /*
 380                  * Some GUIDs break the specification by declaring themselves
 381                  * expensive, but have no corresponding WCxx method. So we
 382                  * should not fail if this happens.
 383                  */
 384                 if (acpi_has_method(handle, wc_method))
 385                         wc_status = acpi_execute_simple_method(handle,
 386                                                                 wc_method, 1);
 387         }
 388
 389         strcpy(method, "WQ");
 390         strncat(method, block->object_id, 2);
 391
 392         status = acpi_evaluate_object(handle, method, &input, out);
 393
 394         /*
 395          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
 396          * the WQxx method failed - we should disable collection anyway.
 397          */
 398         if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
 399                 status = acpi_execute_simple_method(handle, wc_method, 0);
 400         }
 401
 402         return status;
 403 }
 404 EXPORT_SYMBOL_GPL(wmi_query_block);
 405
 406 /**
 407  * wmi_set_block - Write to a WMI block
 408  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 409  * @instance: Instance index
 410  * &in: Buffer containing new values for the data block
 411  *
 412  * Write the contents of the input buffer to an ACPI-WMI data block
 413  */
 414 acpi_status wmi_set_block(const char *guid_string, u8 instance,
 415 const struct acpi_buffer *in)
 416 {
 417         struct guid_block *block = NULL;
 418         struct wmi_block *wblock = NULL;
 419         acpi_handle handle;
 420         struct acpi_object_list input;
 421         union acpi_object params[2];
 422         char method[5] = "WS";
 423
 424         if (!guid_string || !in)
 425                 return AE_BAD_DATA;
 426
 427         if (!find_guid(guid_string, &wblock))
 428                 return AE_ERROR;
 429
 430         block = &wblock->gblock;
 431         handle = wblock->handle;
 432
 433         if (block->instance_count < instance)
 434                 return AE_BAD_PARAMETER;
 435
 436         /* Check GUID is a data block */
 437         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 438                 return AE_ERROR;
 439
 440         input.count = 2;
 441         input.pointer = params;
 442         params[0].type = ACPI_TYPE_INTEGER;
 443         params[0].integer.value = instance;
 444
 445         if (block->flags & ACPI_WMI_STRING) {
 446                 params[1].type = ACPI_TYPE_STRING;
 447         } else {
 448                 params[1].type = ACPI_TYPE_BUFFER;
 449         }
 450         params[1].buffer.length = in->length;
 451         params[1].buffer.pointer = in->pointer;
 452
 453         strncat(method, block->object_id, 2);
 454
 455         return acpi_evaluate_object(handle, method, &input, NULL);
 456 }
 457 EXPORT_SYMBOL_GPL(wmi_set_block);
 458
 459 static void wmi_dump_wdg(const struct guid_block *g)
 460 {
 461         char guid_string[37];
 462
 463         wmi_gtoa(g->guid, guid_string);
 464
 465         pr_info("%s:\n", guid_string);
 466         pr_info("\tobject_id: %c%c\n", g->object_id[0], g->object_id[1]);
 467         pr_info("\tnotify_id: %02X\n", g->notify_id);
 468         pr_info("\treserved: %02X\n", g->reserved);
 469         pr_info("\tinstance_count: %d\n", g->instance_count);
 470         pr_info("\tflags: %#x", g->flags);
 471         if (g->flags) {
 472                 if (g->flags & ACPI_WMI_EXPENSIVE)
 473                         pr_cont(" ACPI_WMI_EXPENSIVE");
 474                 if (g->flags & ACPI_WMI_METHOD)
 475                         pr_cont(" ACPI_WMI_METHOD");
 476                 if (g->flags & ACPI_WMI_STRING)
 477                         pr_cont(" ACPI_WMI_STRING");
 478                 if (g->flags & ACPI_WMI_EVENT)
 479                         pr_cont(" ACPI_WMI_EVENT");
 480         }
 481         pr_cont("\n");
 482
 483 }
 484
 485 static void wmi_notify_debug(u32 value, void *context)
 486 {
 487         struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
 488         union acpi_object *obj;
 489         acpi_status status;
 490
 491         status = wmi_get_event_data(value, &response);
 492         if (status != AE_OK) {
 493                 pr_info("bad event status 0x%x\n", status);
 494                 return;
 495         }
 496
 497         obj = (union acpi_object *)response.pointer;
 498
 499         if (!obj)
 500                 return;
 501
 502         pr_info("DEBUG Event ");
 503         switch(obj->type) {
 504         case ACPI_TYPE_BUFFER:
 505                 pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
 506                 break;
 507         case ACPI_TYPE_STRING:
 508                 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
 509                 break;
 510         case ACPI_TYPE_INTEGER:
 511                 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
 512                 break;
 513         case ACPI_TYPE_PACKAGE:
 514                 pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
 515                 break;
 516         default:
 517                 pr_cont("object type 0x%X\n", obj->type);
 518         }
 519         kfree(obj);
 520 }
 521
 522 /**
 523  * wmi_install_notify_handler - Register handler for WMI events
 524  * @handler: Function to handle notifications
 525  * @data: Data to be returned to handler when event is fired
 526  *
 527  * Register a handler for events sent to the ACPI-WMI mapper device.
 528  */
 529 acpi_status wmi_install_notify_handler(const char *guid,
 530 wmi_notify_handler handler, void *data)
 531 {
 532         struct wmi_block *block;
 533         acpi_status status = AE_NOT_EXIST;
 534         char tmp[16], guid_input[16];
 535         struct list_head *p;
 536
 537         if (!guid || !handler)
 538                 return AE_BAD_PARAMETER;
 539
 540         wmi_parse_guid(guid, tmp);
 541         wmi_swap_bytes(tmp, guid_input);
 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_ALREADY_ACQUIRED;
 551
 552                         block->handler = handler;
 553                         block->handler_data = data;
 554
 555                         wmi_status = wmi_method_enable(block, 1);
 556                         if ((wmi_status != AE_OK) ||
 557                             ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
 558                                 status = wmi_status;
 559                 }
 560         }
 561
 562         return status;
 563 }
 564 EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
 565
 566 /**
 567  * wmi_uninstall_notify_handler - Unregister handler for WMI events
 568  *
 569  * Unregister handler for events sent to the ACPI-WMI mapper device.
 570  */
 571 acpi_status wmi_remove_notify_handler(const char *guid)
 572 {
 573         struct wmi_block *block;
 574         acpi_status status = AE_NOT_EXIST;
 575         char tmp[16], guid_input[16];
 576         struct list_head *p;
 577
 578         if (!guid)
 579                 return AE_BAD_PARAMETER;
 580
 581         wmi_parse_guid(guid, tmp);
 582         wmi_swap_bytes(tmp, guid_input);
 583
 584         list_for_each(p, &wmi_block_list) {
 585                 acpi_status wmi_status;
 586                 block = list_entry(p, struct wmi_block, list);
 587
 588                 if (memcmp(block->gblock.guid, guid_input, 16) == 0) {
 589                         if (!block->handler ||
 590                             block->handler == wmi_notify_debug)
 591                                 return AE_NULL_ENTRY;
 592
 593                         if (debug_event) {
 594                                 block->handler = wmi_notify_debug;
 595                                 status = AE_OK;
 596                         } else {
 597                                 wmi_status = wmi_method_enable(block, 0);
 598                                 block->handler = NULL;
 599                                 block->handler_data = NULL;
 600                                 if ((wmi_status != AE_OK) ||
 601                                     ((wmi_status == AE_OK) &&
 602                                      (status == AE_NOT_EXIST)))
 603                                         status = wmi_status;
 604                         }
 605                 }
 606         }
 607
 608         return status;
 609 }
 610 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
 611
 612 /**
 613  * wmi_get_event_data - Get WMI data associated with an event
 614  *
 615  * @event: Event to find
 616  * @out: Buffer to hold event data. out->pointer should be freed with kfree()
 617  *
 618  * Returns extra data associated with an event in WMI.
 619  */
 620 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
 621 {
 622         struct acpi_object_list input;
 623         union acpi_object params[1];
 624         struct guid_block *gblock;
 625         struct wmi_block *wblock;
 626         struct list_head *p;
 627
 628         input.count = 1;
 629         input.pointer = params;
 630         params[0].type = ACPI_TYPE_INTEGER;
 631         params[0].integer.value = event;
 632
 633         list_for_each(p, &wmi_block_list) {
 634                 wblock = list_entry(p, struct wmi_block, list);
 635                 gblock = &wblock->gblock;
 636
 637                 if ((gblock->flags & ACPI_WMI_EVENT) &&
 638                         (gblock->notify_id == event))
 639                         return acpi_evaluate_object(wblock->handle, "_WED",
 640                                 &input, out);
 641         }
 642
 643         return AE_NOT_FOUND;
 644 }
 645 EXPORT_SYMBOL_GPL(wmi_get_event_data);
 646
 647 /**
 648  * wmi_has_guid - Check if a GUID is available
 649  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 650  *
 651  * Check if a given GUID is defined by _WDG
 652  */
 653 bool wmi_has_guid(const char *guid_string)
 654 {
 655         return find_guid(guid_string, NULL);
 656 }
 657 EXPORT_SYMBOL_GPL(wmi_has_guid);
 658
 659 /*
 660  * sysfs interface
 661  */
 662 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 663                              char *buf)
 664 {
 665         char guid_string[37];
 666         struct wmi_block *wblock;
 667
 668         wblock = dev_get_drvdata(dev);
 669         if (!wblock) {
 670                 strcat(buf, "\n");
 671                 return strlen(buf);
 672         }
 673
 674         wmi_gtoa(wblock->gblock.guid, guid_string);
 675
 676         return sprintf(buf, "wmi:%s\n", guid_string);
 677 }
 678 static DEVICE_ATTR_RO(modalias);
 679
 680 static struct attribute *wmi_attrs[] = {
 681         &dev_attr_modalias.attr,
 682         NULL,
 683 };
 684 ATTRIBUTE_GROUPS(wmi);
 685
 686 static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 687 {
 688         char guid_string[37];
 689
 690         struct wmi_block *wblock;
 691
 692         if (add_uevent_var(env, "MODALIAS="))
 693                 return -ENOMEM;
 694
 695         wblock = dev_get_drvdata(dev);
 696         if (!wblock)
 697                 return -ENOMEM;
 698
 699         wmi_gtoa(wblock->gblock.guid, guid_string);
 700
 701         strcpy(&env->buf[env->buflen - 1], "wmi:");
 702         memcpy(&env->buf[env->buflen - 1 + 4], guid_string, 36);
 703         env->buflen += 40;
 704
 705         return 0;
 706 }
 707
 708 static void wmi_dev_free(struct device *dev)
 709 {
 710         struct wmi_block *wmi_block = container_of(dev, struct wmi_block, dev);
 711
 712         kfree(wmi_block);
 713 }
 714
 715 static struct class wmi_class = {
 716         .name = "wmi",
 717         .dev_release = wmi_dev_free,
 718         .dev_uevent = wmi_dev_uevent,
 719         .dev_groups = wmi_groups,
 720 };
 721
 722 static int wmi_create_device(const struct guid_block *gblock,
 723                              struct wmi_block *wblock, acpi_handle handle)
 724 {
 725         char guid_string[37];
 726
 727         wblock->dev.class = &wmi_class;
 728
 729         wmi_gtoa(gblock->guid, guid_string);
 730         dev_set_name(&wblock->dev, "%s", guid_string);
 731
 732         dev_set_drvdata(&wblock->dev, wblock);
 733
 734         return device_register(&wblock->dev);
 735 }
 736
 737 static void wmi_free_devices(void)
 738 {
 739         struct wmi_block *wblock, *next;
 740
 741         /* Delete devices for all the GUIDs */
 742         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
 743                 list_del(&wblock->list);
 744                 if (wblock->dev.class)
 745                         device_unregister(&wblock->dev);
 746                 else
 747                         kfree(wblock);
 748         }
 749 }
 750
 751 static bool guid_already_parsed(const char *guid_string)
 752 {
 753         struct wmi_block *wblock;
 754
 755         list_for_each_entry(wblock, &wmi_block_list, list)
 756                 if (memcmp(wblock->gblock.guid, guid_string, 16) == 0)
 757                         return true;
 758
 759         return false;
 760 }
 761
 762 /*
 763  * Parse the _WDG method for the GUID data blocks
 764  */
 765 static int parse_wdg(acpi_handle handle)
 766 {
 767         struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
 768         union acpi_object *obj;
 769         const struct guid_block *gblock;
 770         struct wmi_block *wblock;
 771         acpi_status status;
 772         int retval;
 773         u32 i, total;
 774
 775         status = acpi_evaluate_object(handle, "_WDG", NULL, &out);
 776         if (ACPI_FAILURE(status))
 777                 return -ENXIO;
 778
 779         obj = (union acpi_object *) out.pointer;
 780         if (!obj)
 781                 return -ENXIO;
 782
 783         if (obj->type != ACPI_TYPE_BUFFER) {
 784                 retval = -ENXIO;
 785                 goto out_free_pointer;
 786         }
 787
 788         gblock = (const struct guid_block *)obj->buffer.pointer;
 789         total = obj->buffer.length / sizeof(struct guid_block);
 790
 791         for (i = 0; i < total; i++) {
 792                 if (debug_dump_wdg)
 793                         wmi_dump_wdg(&gblock[i]);
 794
 795                 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
 796                 if (!wblock)
 797                         return -ENOMEM;
 798
 799                 wblock->handle = handle;
 800                 wblock->gblock = gblock[i];
 801
 802                 /*
 803                   Some WMI devices, like those for nVidia hooks, have a
 804                   duplicate GUID. It's not clear what we should do in this
 805                   case yet, so for now, we'll just ignore the duplicate
 806                   for device creation.
 807                 */
 808                 if (!guid_already_parsed(gblock[i].guid)) {
 809                         retval = wmi_create_device(&gblock[i], wblock, handle);
 810                         if (retval) {
 811                                 wmi_free_devices();
 812                                 goto out_free_pointer;
 813                         }
 814                 }
 815
 816                 list_add_tail(&wblock->list, &wmi_block_list);
 817
 818                 if (debug_event) {
 819                         wblock->handler = wmi_notify_debug;
 820                         wmi_method_enable(wblock, 1);
 821                 }
 822         }
 823
 824         retval = 0;
 825
 826 out_free_pointer:
 827         kfree(out.pointer);
 828
 829         return retval;
 830 }
 831
 832 /*
 833  * WMI can have EmbeddedControl access regions. In which case, we just want to
 834  * hand these off to the EC driver.
 835  */
 836 static acpi_status
 837 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
 838                       u32 bits, u64 *value,
 839                       void *handler_context, void *region_context)
 840 {
 841         int result = 0, i = 0;
 842         u8 temp = 0;
 843
 844         if ((address > 0xFF) || !value)
 845                 return AE_BAD_PARAMETER;
 846
 847         if (function != ACPI_READ && function != ACPI_WRITE)
 848                 return AE_BAD_PARAMETER;
 849
 850         if (bits != 8)
 851                 return AE_BAD_PARAMETER;
 852
 853         if (function == ACPI_READ) {
 854                 result = ec_read(address, &temp);
 855                 (*value) |= ((u64)temp) << i;
 856         } else {
 857                 temp = 0xff & ((*value) >> i);
 858                 result = ec_write(address, temp);
 859         }
 860
 861         switch (result) {
 862         case -EINVAL:
 863                 return AE_BAD_PARAMETER;
 864                 break;
 865         case -ENODEV:
 866                 return AE_NOT_FOUND;
 867                 break;
 868         case -ETIME:
 869                 return AE_TIME;
 870                 break;
 871         default:
 872                 return AE_OK;
 873         }
 874 }
 875
 876 static void acpi_wmi_notify(struct acpi_device *device, u32 event)
 877 {
 878         struct guid_block *block;
 879         struct wmi_block *wblock;
 880         struct list_head *p;
 881         char guid_string[37];
 882
 883         list_for_each(p, &wmi_block_list) {
 884                 wblock = list_entry(p, struct wmi_block, list);
 885                 block = &wblock->gblock;
 886
 887                 if ((block->flags & ACPI_WMI_EVENT) &&
 888                         (block->notify_id == event)) {
 889                         if (wblock->handler)
 890                                 wblock->handler(event, wblock->handler_data);
 891                         if (debug_event) {
 892                                 wmi_gtoa(wblock->gblock.guid, guid_string);
 893                                 pr_info("DEBUG Event GUID: %s\n", guid_string);
 894                         }
 895
 896                         acpi_bus_generate_netlink_event(
 897                                 device->pnp.device_class, dev_name(&device->dev),
 898                                 event, 0);
 899                         break;
 900                 }
 901         }
 902 }
 903
 904 static int acpi_wmi_remove(struct acpi_device *device)
 905 {
 906         acpi_remove_address_space_handler(device->handle,
 907                                 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
 908         wmi_free_devices();
 909
 910         return 0;
 911 }
 912
 913 static int acpi_wmi_add(struct acpi_device *device)
 914 {
 915         acpi_status status;
 916         int error;
 917
 918         status = acpi_install_address_space_handler(device->handle,
 919                                                     ACPI_ADR_SPACE_EC,
 920                                                     &acpi_wmi_ec_space_handler,
 921                                                     NULL, NULL);
 922         if (ACPI_FAILURE(status)) {
 923                 pr_err("Error installing EC region handler\n");
 924                 return -ENODEV;
 925         }
 926
 927         error = parse_wdg(device->handle);
 928         if (error) {
 929                 acpi_remove_address_space_handler(device->handle,
 930                                                   ACPI_ADR_SPACE_EC,
 931                                                   &acpi_wmi_ec_space_handler);
 932                 pr_err("Failed to parse WDG method\n");
 933                 return error;
 934         }
 935
 936         return 0;
 937 }
 938
 939 static int __init acpi_wmi_init(void)
 940 {
 941         int error;
 942
 943         if (acpi_disabled)
 944                 return -ENODEV;
 945
 946         error = class_register(&wmi_class);
 947         if (error)
 948                 return error;
 949
 950         error = acpi_bus_register_driver(&acpi_wmi_driver);
 951         if (error) {
 952                 pr_err("Error loading mapper\n");
 953                 class_unregister(&wmi_class);
 954                 return error;
 955         }
 956
 957         pr_info("Mapper loaded\n");
 958         return 0;
 959 }
 960
 961 static void __exit acpi_wmi_exit(void)
 962 {
 963         acpi_bus_unregister_driver(&acpi_wmi_driver);
 964         class_unregister(&wmi_class);
 965
 966         pr_info("Mapper unloaded\n");
 967 }
 968
 969 subsys_initcall(acpi_wmi_init);
 970 module_exit(acpi_wmi_exit);