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 <acpi/acpi_bus.h>
  40 #include <acpi/acpi_drivers.h>
  41
  42 ACPI_MODULE_NAME("wmi");
  43 MODULE_AUTHOR("Carlos Corbacho");
  44 MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
  45 MODULE_LICENSE("GPL");
  46
  47 #define ACPI_WMI_CLASS "wmi"
  48
  49 static DEFINE_MUTEX(wmi_data_lock);
  50 static LIST_HEAD(wmi_block_list);
  51
  52 struct guid_block {
  53         char guid[16];
  54         union {
  55                 char object_id[2];
  56                 struct {
  57                         unsigned char notify_id;
  58                         unsigned char reserved;
  59                 };
  60         };
  61         u8 instance_count;
  62         u8 flags;
  63 };
  64
  65 struct wmi_block {
  66         struct list_head list;
  67         struct guid_block gblock;
  68         acpi_handle handle;
  69         wmi_notify_handler handler;
  70         void *handler_data;
  71         struct device dev;
  72 };
  73
  74
  75 /*
  76  * If the GUID data block is marked as expensive, we must enable and
  77  * explicitily disable data collection.
  78  */
  79 #define ACPI_WMI_EXPENSIVE   0x1
  80 #define ACPI_WMI_METHOD      0x2        /* GUID is a method */
  81 #define ACPI_WMI_STRING      0x4        /* GUID takes & returns a string */
  82 #define ACPI_WMI_EVENT       0x8        /* GUID is an event */
  83
  84 static int debug_event;
  85 module_param(debug_event, bool, 0444);
  86 MODULE_PARM_DESC(debug_event,
  87                  "Log WMI Events [0/1]");
  88
  89 static int debug_dump_wdg;
  90 module_param(debug_dump_wdg, bool, 0444);
  91 MODULE_PARM_DESC(debug_dump_wdg,
  92                  "Dump available WMI interfaces [0/1]");
  93
  94 static int acpi_wmi_remove(struct acpi_device *device, int type);
  95 static int acpi_wmi_add(struct acpi_device *device);
  96 static void acpi_wmi_notify(struct acpi_device *device, u32 event);
  97
  98 static const struct acpi_device_id wmi_device_ids[] = {
  99         {"PNP0C14", 0},
 100         {"pnp0c14", 0},
 101         {"", 0},
 102 };
 103 MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
 104
 105 static struct acpi_driver acpi_wmi_driver = {
 106         .name = "wmi",
 107         .class = ACPI_WMI_CLASS,
 108         .ids = wmi_device_ids,
 109         .ops = {
 110                 .add = acpi_wmi_add,
 111                 .remove = acpi_wmi_remove,
 112                 .notify = acpi_wmi_notify,
 113         },
 114 };
 115
 116 /*
 117  * GUID parsing functions
 118  */
 119
 120 /**
 121  * wmi_parse_hexbyte - Convert a ASCII hex number to a byte
 122  * @src:  Pointer to at least 2 characters to convert.
 123  *
 124  * Convert a two character ASCII hex string to a number.
 125  *
 126  * Return:  0-255  Success, the byte was parsed correctly
 127  *          -1     Error, an invalid character was supplied
 128  */
 129 static int wmi_parse_hexbyte(const u8 *src)
 130 {
 131         int h;
 132         int value;
 133
 134         /* high part */
 135         h = value = hex_to_bin(src[0]);
 136         if (value < 0)
 137                 return -1;
 138
 139         /* low part */
 140         value = hex_to_bin(src[1]);
 141         if (value >= 0)
 142                 return (h << 4) | value;
 143         return -1;
 144 }
 145
 146 /**
 147  * wmi_swap_bytes - Rearrange GUID bytes to match GUID binary
 148  * @src:   Memory block holding binary GUID (16 bytes)
 149  * @dest:  Memory block to hold byte swapped binary GUID (16 bytes)
 150  *
 151  * Byte swap a binary GUID to match it's real GUID value
 152  */
 153 static void wmi_swap_bytes(u8 *src, u8 *dest)
 154 {
 155         int i;
 156
 157         for (i = 0; i <= 3; i++)
 158                 memcpy(dest + i, src + (3 - i), 1);
 159
 160         for (i = 0; i <= 1; i++)
 161                 memcpy(dest + 4 + i, src + (5 - i), 1);
 162
 163         for (i = 0; i <= 1; i++)
 164                 memcpy(dest + 6 + i, src + (7 - i), 1);
 165
 166         memcpy(dest + 8, src + 8, 8);
 167 }
 168
 169 /**
 170  * wmi_parse_guid - Convert GUID from ASCII to binary
 171  * @src:   36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 172  * @dest:  Memory block to hold binary GUID (16 bytes)
 173  *
 174  * N.B. The GUID need not be NULL terminated.
 175  *
 176  * Return:  'true'   @dest contains binary GUID
 177  *          'false'  @dest contents are undefined
 178  */
 179 static bool wmi_parse_guid(const u8 *src, u8 *dest)
 180 {
 181         static const int size[] = { 4, 2, 2, 2, 6 };
 182         int i, j, v;
 183
 184         if (src[8]  != '-' || src[13] != '-' ||
 185                 src[18] != '-' || src[23] != '-')
 186                 return false;
 187
 188         for (j = 0; j < 5; j++, src++) {
 189                 for (i = 0; i < size[j]; i++, src += 2, *dest++ = v) {
 190                         v = wmi_parse_hexbyte(src);
 191                         if (v < 0)
 192                                 return false;
 193                 }
 194         }
 195
 196         return true;
 197 }
 198
 199 /*
 200  * Convert a raw GUID to the ACII string representation
 201  */
 202 static int wmi_gtoa(const char *in, char *out)
 203 {
 204         int i;
 205
 206         for (i = 3; i >= 0; i--)
 207                 out += sprintf(out, "%02X", in[i] & 0xFF);
 208
 209         out += sprintf(out, "-");
 210         out += sprintf(out, "%02X", in[5] & 0xFF);
 211         out += sprintf(out, "%02X", in[4] & 0xFF);
 212         out += sprintf(out, "-");
 213         out += sprintf(out, "%02X", in[7] & 0xFF);
 214         out += sprintf(out, "%02X", in[6] & 0xFF);
 215         out += sprintf(out, "-");
 216         out += sprintf(out, "%02X", in[8] & 0xFF);
 217         out += sprintf(out, "%02X", in[9] & 0xFF);
 218         out += sprintf(out, "-");
 219
 220         for (i = 10; i <= 15; i++)
 221                 out += sprintf(out, "%02X", in[i] & 0xFF);
 222
 223         *out = '\0';
 224         return 0;
 225 }
 226
 227 static bool find_guid(const char *guid_string, struct wmi_block **out)
 228 {
 229         char tmp[16], guid_input[16];
 230         struct wmi_block *wblock;
 231         struct guid_block *block;
 232         struct list_head *p;
 233
 234         wmi_parse_guid(guid_string, tmp);
 235         wmi_swap_bytes(tmp, guid_input);
 236
 237         list_for_each(p, &wmi_block_list) {
 238                 wblock = list_entry(p, struct wmi_block, list);
 239                 block = &wblock->gblock;
 240
 241                 if (memcmp(block->guid, guid_input, 16) == 0) {
 242                         if (out)
 243                                 *out = wblock;
 244                         return 1;
 245                 }
 246         }
 247         return 0;
 248 }
 249
 250 static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable)
 251 {
 252         struct guid_block *block = NULL;
 253         char method[5];
 254         struct acpi_object_list input;
 255         union acpi_object params[1];
 256         acpi_status status;
 257         acpi_handle handle;
 258
 259         block = &wblock->gblock;
 260         handle = wblock->handle;
 261
 262         if (!block)
 263                 return AE_NOT_EXIST;
 264
 265         input.count = 1;
 266         input.pointer = params;
 267         params[0].type = ACPI_TYPE_INTEGER;
 268         params[0].integer.value = enable;
 269
 270         snprintf(method, 5, "WE%02X", block->notify_id);
 271         status = acpi_evaluate_object(handle, method, &input, NULL);
 272
 273         if (status != AE_OK && status != AE_NOT_FOUND)
 274                 return status;
 275         else
 276                 return AE_OK;
 277 }
 278
 279 /*
 280  * Exported WMI functions
 281  */
 282 /**
 283  * wmi_evaluate_method - Evaluate a WMI method
 284  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 285  * @instance: Instance index
 286  * @method_id: Method ID to call
 287  * &in: Buffer containing input for the method call
 288  * &out: Empty buffer to return the method results
 289  *
 290  * Call an ACPI-WMI method
 291  */
 292 acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
 293 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
 294 {
 295         struct guid_block *block = NULL;
 296         struct wmi_block *wblock = NULL;
 297         acpi_handle handle;
 298         acpi_status status;
 299         struct acpi_object_list input;
 300         union acpi_object params[3];
 301         char method[5] = "WM";
 302
 303         if (!find_guid(guid_string, &wblock))
 304                 return AE_ERROR;
 305
 306         block = &wblock->gblock;
 307         handle = wblock->handle;
 308
 309         if (!(block->flags & ACPI_WMI_METHOD))
 310                 return AE_BAD_DATA;
 311
 312         if (block->instance_count < instance)
 313                 return AE_BAD_PARAMETER;
 314
 315         input.count = 2;
 316         input.pointer = params;
 317         params[0].type = ACPI_TYPE_INTEGER;
 318         params[0].integer.value = instance;
 319         params[1].type = ACPI_TYPE_INTEGER;
 320         params[1].integer.value = method_id;
 321
 322         if (in) {
 323                 input.count = 3;
 324
 325                 if (block->flags & ACPI_WMI_STRING) {
 326                         params[2].type = ACPI_TYPE_STRING;
 327                 } else {
 328                         params[2].type = ACPI_TYPE_BUFFER;
 329                 }
 330                 params[2].buffer.length = in->length;
 331                 params[2].buffer.pointer = in->pointer;
 332         }
 333
 334         strncat(method, block->object_id, 2);
 335
 336         status = acpi_evaluate_object(handle, method, &input, out);
 337
 338         return status;
 339 }
 340 EXPORT_SYMBOL_GPL(wmi_evaluate_method);
 341
 342 /**
 343  * wmi_query_block - Return contents of a WMI block
 344  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 345  * @instance: Instance index
 346  * &out: Empty buffer to return the contents of the data block to
 347  *
 348  * Return the contents of an ACPI-WMI data block to a buffer
 349  */
 350 acpi_status wmi_query_block(const char *guid_string, u8 instance,
 351 struct acpi_buffer *out)
 352 {
 353         struct guid_block *block = NULL;
 354         struct wmi_block *wblock = NULL;
 355         acpi_handle handle, wc_handle;
 356         acpi_status status, wc_status = AE_ERROR;
 357         struct acpi_object_list input, wc_input;
 358         union acpi_object wc_params[1], wq_params[1];
 359         char method[5];
 360         char wc_method[5] = "WC";
 361
 362         if (!guid_string || !out)
 363                 return AE_BAD_PARAMETER;
 364
 365         if (!find_guid(guid_string, &wblock))
 366                 return AE_ERROR;
 367
 368         block = &wblock->gblock;
 369         handle = wblock->handle;
 370
 371         if (block->instance_count < instance)
 372                 return AE_BAD_PARAMETER;
 373
 374         /* Check GUID is a data block */
 375         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 376                 return AE_ERROR;
 377
 378         input.count = 1;
 379         input.pointer = wq_params;
 380         wq_params[0].type = ACPI_TYPE_INTEGER;
 381         wq_params[0].integer.value = instance;
 382
 383         /*
 384          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
 385          * enable collection.
 386          */
 387         if (block->flags & ACPI_WMI_EXPENSIVE) {
 388                 wc_input.count = 1;
 389                 wc_input.pointer = wc_params;
 390                 wc_params[0].type = ACPI_TYPE_INTEGER;
 391                 wc_params[0].integer.value = 1;
 392
 393                 strncat(wc_method, block->object_id, 2);
 394
 395                 /*
 396                  * Some GUIDs break the specification by declaring themselves
 397                  * expensive, but have no corresponding WCxx method. So we
 398                  * should not fail if this happens.
 399                  */
 400                 wc_status = acpi_get_handle(handle, wc_method, &wc_handle);
 401                 if (ACPI_SUCCESS(wc_status))
 402                         wc_status = acpi_evaluate_object(handle, wc_method,
 403                                 &wc_input, NULL);
 404         }
 405
 406         strcpy(method, "WQ");
 407         strncat(method, block->object_id, 2);
 408
 409         status = acpi_evaluate_object(handle, method, &input, out);
 410
 411         /*
 412          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
 413          * the WQxx method failed - we should disable collection anyway.
 414          */
 415         if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
 416                 wc_params[0].integer.value = 0;
 417                 status = acpi_evaluate_object(handle,
 418                 wc_method, &wc_input, NULL);
 419         }
 420
 421         return status;
 422 }
 423 EXPORT_SYMBOL_GPL(wmi_query_block);
 424
 425 /**
 426  * wmi_set_block - Write to a WMI block
 427  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 428  * @instance: Instance index
 429  * &in: Buffer containing new values for the data block
 430  *
 431  * Write the contents of the input buffer to an ACPI-WMI data block
 432  */
 433 acpi_status wmi_set_block(const char *guid_string, u8 instance,
 434 const struct acpi_buffer *in)
 435 {
 436         struct guid_block *block = NULL;
 437         struct wmi_block *wblock = NULL;
 438         acpi_handle handle;
 439         struct acpi_object_list input;
 440         union acpi_object params[2];
 441         char method[5] = "WS";
 442
 443         if (!guid_string || !in)
 444                 return AE_BAD_DATA;
 445
 446         if (!find_guid(guid_string, &wblock))
 447                 return AE_ERROR;
 448
 449         block = &wblock->gblock;
 450         handle = wblock->handle;
 451
 452         if (block->instance_count < instance)
 453                 return AE_BAD_PARAMETER;
 454
 455         /* Check GUID is a data block */
 456         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 457                 return AE_ERROR;
 458
 459         input.count = 2;
 460         input.pointer = params;
 461         params[0].type = ACPI_TYPE_INTEGER;
 462         params[0].integer.value = instance;
 463
 464         if (block->flags & ACPI_WMI_STRING) {
 465                 params[1].type = ACPI_TYPE_STRING;
 466         } else {
 467                 params[1].type = ACPI_TYPE_BUFFER;
 468         }
 469         params[1].buffer.length = in->length;
 470         params[1].buffer.pointer = in->pointer;
 471
 472         strncat(method, block->object_id, 2);
 473
 474         return acpi_evaluate_object(handle, method, &input, NULL);
 475 }
 476 EXPORT_SYMBOL_GPL(wmi_set_block);
 477
 478 static void wmi_dump_wdg(const struct guid_block *g)
 479 {
 480         char guid_string[37];
 481
 482         wmi_gtoa(g->guid, guid_string);
 483
 484         pr_info("%s:\n", guid_string);
 485         pr_info("\tobject_id: %c%c\n", g->object_id[0], g->object_id[1]);
 486         pr_info("\tnotify_id: %02X\n", g->notify_id);
 487         pr_info("\treserved: %02X\n", g->reserved);
 488         pr_info("\tinstance_count: %d\n", g->instance_count);
 489         pr_info("\tflags: %#x", g->flags);
 490         if (g->flags) {
 491                 if (g->flags & ACPI_WMI_EXPENSIVE)
 492                         pr_cont(" ACPI_WMI_EXPENSIVE");
 493                 if (g->flags & ACPI_WMI_METHOD)
 494                         pr_cont(" ACPI_WMI_METHOD");
 495                 if (g->flags & ACPI_WMI_STRING)
 496                         pr_cont(" ACPI_WMI_STRING");
 497                 if (g->flags & ACPI_WMI_EVENT)
 498                         pr_cont(" ACPI_WMI_EVENT");
 499         }
 500         pr_cont("\n");
 501
 502 }
 503
 504 static void wmi_notify_debug(u32 value, void *context)
 505 {
 506         struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
 507         union acpi_object *obj;
 508         acpi_status status;
 509
 510         status = wmi_get_event_data(value, &response);
 511         if (status != AE_OK) {
 512                 pr_info("bad event status 0x%x\n", status);
 513                 return;
 514         }
 515
 516         obj = (union acpi_object *)response.pointer;
 517
 518         if (!obj)
 519                 return;
 520
 521         pr_info("DEBUG Event ");
 522         switch(obj->type) {
 523         case ACPI_TYPE_BUFFER:
 524                 pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
 525                 break;
 526         case ACPI_TYPE_STRING:
 527                 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
 528                 break;
 529         case ACPI_TYPE_INTEGER:
 530                 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
 531                 break;
 532         case ACPI_TYPE_PACKAGE:
 533                 pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
 534                 break;
 535         default:
 536                 pr_cont("object type 0x%X\n", obj->type);
 537         }
 538         kfree(obj);
 539 }
 540
 541 /**
 542  * wmi_install_notify_handler - Register handler for WMI events
 543  * @handler: Function to handle notifications
 544  * @data: Data to be returned to handler when event is fired
 545  *
 546  * Register a handler for events sent to the ACPI-WMI mapper device.
 547  */
 548 acpi_status wmi_install_notify_handler(const char *guid,
 549 wmi_notify_handler handler, void *data)
 550 {
 551         struct wmi_block *block;
 552         acpi_status status = AE_NOT_EXIST;
 553         char tmp[16], guid_input[16];
 554         struct list_head *p;
 555
 556         if (!guid || !handler)
 557                 return AE_BAD_PARAMETER;
 558
 559         wmi_parse_guid(guid, tmp);
 560         wmi_swap_bytes(tmp, guid_input);
 561
 562         list_for_each(p, &wmi_block_list) {
 563                 acpi_status wmi_status;
 564                 block = list_entry(p, struct wmi_block, list);
 565
 566                 if (memcmp(block->gblock.guid, guid_input, 16) == 0) {
 567                         if (block->handler &&
 568                             block->handler != wmi_notify_debug)
 569                                 return AE_ALREADY_ACQUIRED;
 570
 571                         block->handler = handler;
 572                         block->handler_data = data;
 573
 574                         wmi_status = wmi_method_enable(block, 1);
 575                         if ((wmi_status != AE_OK) ||
 576                             ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
 577                                 status = wmi_status;
 578                 }
 579         }
 580
 581         return status;
 582 }
 583 EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
 584
 585 /**
 586  * wmi_uninstall_notify_handler - Unregister handler for WMI events
 587  *
 588  * Unregister handler for events sent to the ACPI-WMI mapper device.
 589  */
 590 acpi_status wmi_remove_notify_handler(const char *guid)
 591 {
 592         struct wmi_block *block;
 593         acpi_status status = AE_NOT_EXIST;
 594         char tmp[16], guid_input[16];
 595         struct list_head *p;
 596
 597         if (!guid)
 598                 return AE_BAD_PARAMETER;
 599
 600         wmi_parse_guid(guid, tmp);
 601         wmi_swap_bytes(tmp, guid_input);
 602
 603         list_for_each(p, &wmi_block_list) {
 604                 acpi_status wmi_status;
 605                 block = list_entry(p, struct wmi_block, list);
 606
 607                 if (memcmp(block->gblock.guid, guid_input, 16) == 0) {
 608                         if (!block->handler ||
 609                             block->handler == wmi_notify_debug)
 610                                 return AE_NULL_ENTRY;
 611
 612                         if (debug_event) {
 613                                 block->handler = wmi_notify_debug;
 614                                 status = AE_OK;
 615                         } else {
 616                                 wmi_status = wmi_method_enable(block, 0);
 617                                 block->handler = NULL;
 618                                 block->handler_data = NULL;
 619                                 if ((wmi_status != AE_OK) ||
 620                                     ((wmi_status == AE_OK) &&
 621                                      (status == AE_NOT_EXIST)))
 622                                         status = wmi_status;
 623                         }
 624                 }
 625         }
 626
 627         return status;
 628 }
 629 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
 630
 631 /**
 632  * wmi_get_event_data - Get WMI data associated with an event
 633  *
 634  * @event: Event to find
 635  * @out: Buffer to hold event data. out->pointer should be freed with kfree()
 636  *
 637  * Returns extra data associated with an event in WMI.
 638  */
 639 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
 640 {
 641         struct acpi_object_list input;
 642         union acpi_object params[1];
 643         struct guid_block *gblock;
 644         struct wmi_block *wblock;
 645         struct list_head *p;
 646
 647         input.count = 1;
 648         input.pointer = params;
 649         params[0].type = ACPI_TYPE_INTEGER;
 650         params[0].integer.value = event;
 651
 652         list_for_each(p, &wmi_block_list) {
 653                 wblock = list_entry(p, struct wmi_block, list);
 654                 gblock = &wblock->gblock;
 655
 656                 if ((gblock->flags & ACPI_WMI_EVENT) &&
 657                         (gblock->notify_id == event))
 658                         return acpi_evaluate_object(wblock->handle, "_WED",
 659                                 &input, out);
 660         }
 661
 662         return AE_NOT_FOUND;
 663 }
 664 EXPORT_SYMBOL_GPL(wmi_get_event_data);
 665
 666 /**
 667  * wmi_has_guid - Check if a GUID is available
 668  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 669  *
 670  * Check if a given GUID is defined by _WDG
 671  */
 672 bool wmi_has_guid(const char *guid_string)
 673 {
 674         return find_guid(guid_string, NULL);
 675 }
 676 EXPORT_SYMBOL_GPL(wmi_has_guid);
 677
 678 /*
 679  * sysfs interface
 680  */
 681 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 682                              char *buf)
 683 {
 684         char guid_string[37];
 685         struct wmi_block *wblock;
 686
 687         wblock = dev_get_drvdata(dev);
 688         if (!wblock)
 689                 return -ENOMEM;
 690
 691         wmi_gtoa(wblock->gblock.guid, guid_string);
 692
 693         return sprintf(buf, "wmi:%s\n", guid_string);
 694 }
 695
 696 static struct device_attribute wmi_dev_attrs[] = {
 697         __ATTR_RO(modalias),
 698         __ATTR_NULL
 699 };
 700
 701 static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 702 {
 703         char guid_string[37];
 704
 705         struct wmi_block *wblock;
 706
 707         if (add_uevent_var(env, "MODALIAS="))
 708                 return -ENOMEM;
 709
 710         wblock = dev_get_drvdata(dev);
 711         if (!wblock)
 712                 return -ENOMEM;
 713
 714         wmi_gtoa(wblock->gblock.guid, guid_string);
 715
 716         strcpy(&env->buf[env->buflen - 1], "wmi:");
 717         memcpy(&env->buf[env->buflen - 1 + 4], guid_string, 36);
 718         env->buflen += 40;
 719
 720         return 0;
 721 }
 722
 723 static void wmi_dev_free(struct device *dev)
 724 {
 725         struct wmi_block *wmi_block = container_of(dev, struct wmi_block, dev);
 726
 727         kfree(wmi_block);
 728 }
 729
 730 static struct class wmi_class = {
 731         .name = "wmi",
 732         .dev_release = wmi_dev_free,
 733         .dev_uevent = wmi_dev_uevent,
 734         .dev_attrs = wmi_dev_attrs,
 735 };
 736
 737 static int wmi_create_device(const struct guid_block *gblock,
 738                              struct wmi_block *wblock, acpi_handle handle)
 739 {
 740         char guid_string[37];
 741
 742         wblock->dev.class = &wmi_class;
 743
 744         wmi_gtoa(gblock->guid, guid_string);
 745         dev_set_name(&wblock->dev, guid_string);
 746
 747         dev_set_drvdata(&wblock->dev, wblock);
 748
 749         return device_register(&wblock->dev);
 750 }
 751
 752 static void wmi_free_devices(void)
 753 {
 754         struct wmi_block *wblock, *next;
 755
 756         /* Delete devices for all the GUIDs */
 757         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
 758                 list_del(&wblock->list);
 759                 if (wblock->dev.class)
 760                         device_unregister(&wblock->dev);
 761                 else
 762                         kfree(wblock);
 763         }
 764 }
 765
 766 static bool guid_already_parsed(const char *guid_string)
 767 {
 768         struct wmi_block *wblock;
 769
 770         list_for_each_entry(wblock, &wmi_block_list, list)
 771                 if (memcmp(wblock->gblock.guid, guid_string, 16) == 0)
 772                         return true;
 773
 774         return false;
 775 }
 776
 777 /*
 778  * Parse the _WDG method for the GUID data blocks
 779  */
 780 static acpi_status parse_wdg(acpi_handle handle)
 781 {
 782         struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
 783         union acpi_object *obj;
 784         const struct guid_block *gblock;
 785         struct wmi_block *wblock;
 786         acpi_status status;
 787         int retval;
 788         u32 i, total;
 789
 790         status = acpi_evaluate_object(handle, "_WDG", NULL, &out);
 791         if (ACPI_FAILURE(status))
 792                 return -ENXIO;
 793
 794         obj = (union acpi_object *) out.pointer;
 795         if (!obj)
 796                 return -ENXIO;
 797
 798         if (obj->type != ACPI_TYPE_BUFFER) {
 799                 retval = -ENXIO;
 800                 goto out_free_pointer;
 801         }
 802
 803         gblock = (const struct guid_block *)obj->buffer.pointer;
 804         total = obj->buffer.length / sizeof(struct guid_block);
 805
 806         for (i = 0; i < total; i++) {
 807                 if (debug_dump_wdg)
 808                         wmi_dump_wdg(&gblock[i]);
 809
 810                 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
 811                 if (!wblock)
 812                         return AE_NO_MEMORY;
 813
 814                 wblock->handle = handle;
 815                 wblock->gblock = gblock[i];
 816
 817                 /*
 818                   Some WMI devices, like those for nVidia hooks, have a
 819                   duplicate GUID. It's not clear what we should do in this
 820                   case yet, so for now, we'll just ignore the duplicate
 821                   for device creation.
 822                 */
 823                 if (!guid_already_parsed(gblock[i].guid)) {
 824                         retval = wmi_create_device(&gblock[i], wblock, handle);
 825                         if (retval) {
 826                                 wmi_free_devices();
 827                                 goto out_free_pointer;
 828                         }
 829                 }
 830
 831                 list_add_tail(&wblock->list, &wmi_block_list);
 832
 833                 if (debug_event) {
 834                         wblock->handler = wmi_notify_debug;
 835                         wmi_method_enable(wblock, 1);
 836                 }
 837         }
 838
 839         retval = 0;
 840
 841 out_free_pointer:
 842         kfree(out.pointer);
 843
 844         return retval;
 845 }
 846
 847 /*
 848  * WMI can have EmbeddedControl access regions. In which case, we just want to
 849  * hand these off to the EC driver.
 850  */
 851 static acpi_status
 852 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
 853                       u32 bits, u64 *value,
 854                       void *handler_context, void *region_context)
 855 {
 856         int result = 0, i = 0;
 857         u8 temp = 0;
 858
 859         if ((address > 0xFF) || !value)
 860                 return AE_BAD_PARAMETER;
 861
 862         if (function != ACPI_READ && function != ACPI_WRITE)
 863                 return AE_BAD_PARAMETER;
 864
 865         if (bits != 8)
 866                 return AE_BAD_PARAMETER;
 867
 868         if (function == ACPI_READ) {
 869                 result = ec_read(address, &temp);
 870                 (*value) |= ((u64)temp) << i;
 871         } else {
 872                 temp = 0xff & ((*value) >> i);
 873                 result = ec_write(address, temp);
 874         }
 875
 876         switch (result) {
 877         case -EINVAL:
 878                 return AE_BAD_PARAMETER;
 879                 break;
 880         case -ENODEV:
 881                 return AE_NOT_FOUND;
 882                 break;
 883         case -ETIME:
 884                 return AE_TIME;
 885                 break;
 886         default:
 887                 return AE_OK;
 888         }
 889 }
 890
 891 static void acpi_wmi_notify(struct acpi_device *device, u32 event)
 892 {
 893         struct guid_block *block;
 894         struct wmi_block *wblock;
 895         struct list_head *p;
 896         char guid_string[37];
 897
 898         list_for_each(p, &wmi_block_list) {
 899                 wblock = list_entry(p, struct wmi_block, list);
 900                 block = &wblock->gblock;
 901
 902                 if ((block->flags & ACPI_WMI_EVENT) &&
 903                         (block->notify_id == event)) {
 904                         if (wblock->handler)
 905                                 wblock->handler(event, wblock->handler_data);
 906                         if (debug_event) {
 907                                 wmi_gtoa(wblock->gblock.guid, guid_string);
 908                                 pr_info("DEBUG Event GUID: %s\n", guid_string);
 909                         }
 910
 911                         acpi_bus_generate_netlink_event(
 912                                 device->pnp.device_class, dev_name(&device->dev),
 913                                 event, 0);
 914                         break;
 915                 }
 916         }
 917 }
 918
 919 static int acpi_wmi_remove(struct acpi_device *device, int type)
 920 {
 921         acpi_remove_address_space_handler(device->handle,
 922                                 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
 923         wmi_free_devices();
 924
 925         return 0;
 926 }
 927
 928 static int acpi_wmi_add(struct acpi_device *device)
 929 {
 930         acpi_status status;
 931         int error;
 932
 933         status = acpi_install_address_space_handler(device->handle,
 934                                                     ACPI_ADR_SPACE_EC,
 935                                                     &acpi_wmi_ec_space_handler,
 936                                                     NULL, NULL);
 937         if (ACPI_FAILURE(status)) {
 938                 pr_err("Error installing EC region handler\n");
 939                 return -ENODEV;
 940         }
 941
 942         error = parse_wdg(device->handle);
 943         if (error) {
 944                 acpi_remove_address_space_handler(device->handle,
 945                                                   ACPI_ADR_SPACE_EC,
 946                                                   &acpi_wmi_ec_space_handler);
 947                 pr_err("Failed to parse WDG method\n");
 948                 return error;
 949         }
 950
 951         return 0;
 952 }
 953
 954 static int __init acpi_wmi_init(void)
 955 {
 956         int error;
 957
 958         if (acpi_disabled)
 959                 return -ENODEV;
 960
 961         error = class_register(&wmi_class);
 962         if (error)
 963                 return error;
 964
 965         error = acpi_bus_register_driver(&acpi_wmi_driver);
 966         if (error) {
 967                 pr_err("Error loading mapper\n");
 968                 class_unregister(&wmi_class);
 969                 return error;
 970         }
 971
 972         pr_info("Mapper loaded\n");
 973         return 0;
 974 }
 975
 976 static void __exit acpi_wmi_exit(void)
 977 {
 978         acpi_bus_unregister_driver(&acpi_wmi_driver);
 979         class_unregister(&wmi_class);
 980
 981         pr_info("Mapper unloaded\n");
 982 }
 983
 984 subsys_initcall(acpi_wmi_init);
 985 module_exit(acpi_wmi_exit);