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