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         if (!block)
 260                 return AE_NOT_EXIST;
 261
 262
 263         snprintf(method, 5, "WE%02X", block->notify_id);
 264         status = acpi_execute_simple_method(handle, method, enable);
 265
 266         if (status != AE_OK && status != AE_NOT_FOUND)
 267                 return status;
 268         else
 269                 return AE_OK;
 270 }
 271
 272 /*
 273  * Exported WMI functions
 274  */
 275 /**
 276  * wmi_evaluate_method - Evaluate a WMI method
 277  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 278  * @instance: Instance index
 279  * @method_id: Method ID to call
 280  * &in: Buffer containing input for the method call
 281  * &out: Empty buffer to return the method results
 282  *
 283  * Call an ACPI-WMI method
 284  */
 285 acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
 286 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
 287 {
 288         struct guid_block *block = NULL;
 289         struct wmi_block *wblock = NULL;
 290         acpi_handle handle;
 291         acpi_status status;
 292         struct acpi_object_list input;
 293         union acpi_object params[3];
 294         char method[5] = "WM";
 295
 296         if (!find_guid(guid_string, &wblock))
 297                 return AE_ERROR;
 298
 299         block = &wblock->gblock;
 300         handle = wblock->handle;
 301
 302         if (!(block->flags & ACPI_WMI_METHOD))
 303                 return AE_BAD_DATA;
 304
 305         if (block->instance_count < instance)
 306                 return AE_BAD_PARAMETER;
 307
 308         input.count = 2;
 309         input.pointer = params;
 310         params[0].type = ACPI_TYPE_INTEGER;
 311         params[0].integer.value = instance;
 312         params[1].type = ACPI_TYPE_INTEGER;
 313         params[1].integer.value = method_id;
 314
 315         if (in) {
 316                 input.count = 3;
 317
 318                 if (block->flags & ACPI_WMI_STRING) {
 319                         params[2].type = ACPI_TYPE_STRING;
 320                 } else {
 321                         params[2].type = ACPI_TYPE_BUFFER;
 322                 }
 323                 params[2].buffer.length = in->length;
 324                 params[2].buffer.pointer = in->pointer;
 325         }
 326
 327         strncat(method, block->object_id, 2);
 328
 329         status = acpi_evaluate_object(handle, method, &input, out);
 330
 331         return status;
 332 }
 333 EXPORT_SYMBOL_GPL(wmi_evaluate_method);
 334
 335 /**
 336  * wmi_query_block - Return contents of a WMI block
 337  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 338  * @instance: Instance index
 339  * &out: Empty buffer to return the contents of the data block to
 340  *
 341  * Return the contents of an ACPI-WMI data block to a buffer
 342  */
 343 acpi_status wmi_query_block(const char *guid_string, u8 instance,
 344 struct acpi_buffer *out)
 345 {
 346         struct guid_block *block = NULL;
 347         struct wmi_block *wblock = NULL;
 348         acpi_handle handle;
 349         acpi_status status, wc_status = AE_ERROR;
 350         struct acpi_object_list input;
 351         union acpi_object wq_params[1];
 352         char method[5];
 353         char wc_method[5] = "WC";
 354
 355         if (!guid_string || !out)
 356                 return AE_BAD_PARAMETER;
 357
 358         if (!find_guid(guid_string, &wblock))
 359                 return AE_ERROR;
 360
 361         block = &wblock->gblock;
 362         handle = wblock->handle;
 363
 364         if (block->instance_count < instance)
 365                 return AE_BAD_PARAMETER;
 366
 367         /* Check GUID is a data block */
 368         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 369                 return AE_ERROR;
 370
 371         input.count = 1;
 372         input.pointer = wq_params;
 373         wq_params[0].type = ACPI_TYPE_INTEGER;
 374         wq_params[0].integer.value = instance;
 375
 376         /*
 377          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
 378          * enable collection.
 379          */
 380         if (block->flags & ACPI_WMI_EXPENSIVE) {
 381                 strncat(wc_method, block->object_id, 2);
 382
 383                 /*
 384                  * Some GUIDs break the specification by declaring themselves
 385                  * expensive, but have no corresponding WCxx method. So we
 386                  * should not fail if this happens.
 387                  */
 388                 if (acpi_has_method(handle, wc_method))
 389                         wc_status = acpi_execute_simple_method(handle,
 390                                                                 wc_method, 1);
 391         }
 392
 393         strcpy(method, "WQ");
 394         strncat(method, block->object_id, 2);
 395
 396         status = acpi_evaluate_object(handle, method, &input, out);
 397
 398         /*
 399          * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
 400          * the WQxx method failed - we should disable collection anyway.
 401          */
 402         if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
 403                 status = acpi_execute_simple_method(handle, wc_method, 0);
 404         }
 405
 406         return status;
 407 }
 408 EXPORT_SYMBOL_GPL(wmi_query_block);
 409
 410 /**
 411  * wmi_set_block - Write to a WMI block
 412  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 413  * @instance: Instance index
 414  * &in: Buffer containing new values for the data block
 415  *
 416  * Write the contents of the input buffer to an ACPI-WMI data block
 417  */
 418 acpi_status wmi_set_block(const char *guid_string, u8 instance,
 419 const struct acpi_buffer *in)
 420 {
 421         struct guid_block *block = NULL;
 422         struct wmi_block *wblock = NULL;
 423         acpi_handle handle;
 424         struct acpi_object_list input;
 425         union acpi_object params[2];
 426         char method[5] = "WS";
 427
 428         if (!guid_string || !in)
 429                 return AE_BAD_DATA;
 430
 431         if (!find_guid(guid_string, &wblock))
 432                 return AE_ERROR;
 433
 434         block = &wblock->gblock;
 435         handle = wblock->handle;
 436
 437         if (block->instance_count < instance)
 438                 return AE_BAD_PARAMETER;
 439
 440         /* Check GUID is a data block */
 441         if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 442                 return AE_ERROR;
 443
 444         input.count = 2;
 445         input.pointer = params;
 446         params[0].type = ACPI_TYPE_INTEGER;
 447         params[0].integer.value = instance;
 448
 449         if (block->flags & ACPI_WMI_STRING) {
 450                 params[1].type = ACPI_TYPE_STRING;
 451         } else {
 452                 params[1].type = ACPI_TYPE_BUFFER;
 453         }
 454         params[1].buffer.length = in->length;
 455         params[1].buffer.pointer = in->pointer;
 456
 457         strncat(method, block->object_id, 2);
 458
 459         return acpi_evaluate_object(handle, method, &input, NULL);
 460 }
 461 EXPORT_SYMBOL_GPL(wmi_set_block);
 462
 463 static void wmi_dump_wdg(const struct guid_block *g)
 464 {
 465         char guid_string[37];
 466
 467         wmi_gtoa(g->guid, guid_string);
 468
 469         pr_info("%s:\n", guid_string);
 470         pr_info("\tobject_id: %c%c\n", g->object_id[0], g->object_id[1]);
 471         pr_info("\tnotify_id: %02X\n", g->notify_id);
 472         pr_info("\treserved: %02X\n", g->reserved);
 473         pr_info("\tinstance_count: %d\n", g->instance_count);
 474         pr_info("\tflags: %#x", g->flags);
 475         if (g->flags) {
 476                 if (g->flags & ACPI_WMI_EXPENSIVE)
 477                         pr_cont(" ACPI_WMI_EXPENSIVE");
 478                 if (g->flags & ACPI_WMI_METHOD)
 479                         pr_cont(" ACPI_WMI_METHOD");
 480                 if (g->flags & ACPI_WMI_STRING)
 481                         pr_cont(" ACPI_WMI_STRING");
 482                 if (g->flags & ACPI_WMI_EVENT)
 483                         pr_cont(" ACPI_WMI_EVENT");
 484         }
 485         pr_cont("\n");
 486
 487 }
 488
 489 static void wmi_notify_debug(u32 value, void *context)
 490 {
 491         struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
 492         union acpi_object *obj;
 493         acpi_status status;
 494
 495         status = wmi_get_event_data(value, &response);
 496         if (status != AE_OK) {
 497                 pr_info("bad event status 0x%x\n", status);
 498                 return;
 499         }
 500
 501         obj = (union acpi_object *)response.pointer;
 502
 503         if (!obj)
 504                 return;
 505
 506         pr_info("DEBUG Event ");
 507         switch(obj->type) {
 508         case ACPI_TYPE_BUFFER:
 509                 pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
 510                 break;
 511         case ACPI_TYPE_STRING:
 512                 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
 513                 break;
 514         case ACPI_TYPE_INTEGER:
 515                 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
 516                 break;
 517         case ACPI_TYPE_PACKAGE:
 518                 pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
 519                 break;
 520         default:
 521                 pr_cont("object type 0x%X\n", obj->type);
 522         }
 523         kfree(obj);
 524 }
 525
 526 /**
 527  * wmi_install_notify_handler - Register handler for WMI events
 528  * @handler: Function to handle notifications
 529  * @data: Data to be returned to handler when event is fired
 530  *
 531  * Register a handler for events sent to the ACPI-WMI mapper device.
 532  */
 533 acpi_status wmi_install_notify_handler(const char *guid,
 534 wmi_notify_handler handler, void *data)
 535 {
 536         struct wmi_block *block;
 537         acpi_status status = AE_NOT_EXIST;
 538         char tmp[16], guid_input[16];
 539         struct list_head *p;
 540
 541         if (!guid || !handler)
 542                 return AE_BAD_PARAMETER;
 543
 544         wmi_parse_guid(guid, tmp);
 545         wmi_swap_bytes(tmp, guid_input);
 546
 547         list_for_each(p, &wmi_block_list) {
 548                 acpi_status wmi_status;
 549                 block = list_entry(p, struct wmi_block, list);
 550
 551                 if (memcmp(block->gblock.guid, guid_input, 16) == 0) {
 552                         if (block->handler &&
 553                             block->handler != wmi_notify_debug)
 554                                 return AE_ALREADY_ACQUIRED;
 555
 556                         block->handler = handler;
 557                         block->handler_data = data;
 558
 559                         wmi_status = wmi_method_enable(block, 1);
 560                         if ((wmi_status != AE_OK) ||
 561                             ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
 562                                 status = wmi_status;
 563                 }
 564         }
 565
 566         return status;
 567 }
 568 EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
 569
 570 /**
 571  * wmi_uninstall_notify_handler - Unregister handler for WMI events
 572  *
 573  * Unregister handler for events sent to the ACPI-WMI mapper device.
 574  */
 575 acpi_status wmi_remove_notify_handler(const char *guid)
 576 {
 577         struct wmi_block *block;
 578         acpi_status status = AE_NOT_EXIST;
 579         char tmp[16], guid_input[16];
 580         struct list_head *p;
 581
 582         if (!guid)
 583                 return AE_BAD_PARAMETER;
 584
 585         wmi_parse_guid(guid, tmp);
 586         wmi_swap_bytes(tmp, guid_input);
 587
 588         list_for_each(p, &wmi_block_list) {
 589                 acpi_status wmi_status;
 590                 block = list_entry(p, struct wmi_block, list);
 591
 592                 if (memcmp(block->gblock.guid, guid_input, 16) == 0) {
 593                         if (!block->handler ||
 594                             block->handler == wmi_notify_debug)
 595                                 return AE_NULL_ENTRY;
 596
 597                         if (debug_event) {
 598                                 block->handler = wmi_notify_debug;
 599                                 status = AE_OK;
 600                         } else {
 601                                 wmi_status = wmi_method_enable(block, 0);
 602                                 block->handler = NULL;
 603                                 block->handler_data = NULL;
 604                                 if ((wmi_status != AE_OK) ||
 605                                     ((wmi_status == AE_OK) &&
 606                                      (status == AE_NOT_EXIST)))
 607                                         status = wmi_status;
 608                         }
 609                 }
 610         }
 611
 612         return status;
 613 }
 614 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
 615
 616 /**
 617  * wmi_get_event_data - Get WMI data associated with an event
 618  *
 619  * @event: Event to find
 620  * @out: Buffer to hold event data. out->pointer should be freed with kfree()
 621  *
 622  * Returns extra data associated with an event in WMI.
 623  */
 624 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
 625 {
 626         struct acpi_object_list input;
 627         union acpi_object params[1];
 628         struct guid_block *gblock;
 629         struct wmi_block *wblock;
 630         struct list_head *p;
 631
 632         input.count = 1;
 633         input.pointer = params;
 634         params[0].type = ACPI_TYPE_INTEGER;
 635         params[0].integer.value = event;
 636
 637         list_for_each(p, &wmi_block_list) {
 638                 wblock = list_entry(p, struct wmi_block, list);
 639                 gblock = &wblock->gblock;
 640
 641                 if ((gblock->flags & ACPI_WMI_EVENT) &&
 642                         (gblock->notify_id == event))
 643                         return acpi_evaluate_object(wblock->handle, "_WED",
 644                                 &input, out);
 645         }
 646
 647         return AE_NOT_FOUND;
 648 }
 649 EXPORT_SYMBOL_GPL(wmi_get_event_data);
 650
 651 /**
 652  * wmi_has_guid - Check if a GUID is available
 653  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 654  *
 655  * Check if a given GUID is defined by _WDG
 656  */
 657 bool wmi_has_guid(const char *guid_string)
 658 {
 659         return find_guid(guid_string, NULL);
 660 }
 661 EXPORT_SYMBOL_GPL(wmi_has_guid);
 662
 663 /*
 664  * sysfs interface
 665  */
 666 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 667                              char *buf)
 668 {
 669         char guid_string[37];
 670         struct wmi_block *wblock;
 671
 672         wblock = dev_get_drvdata(dev);
 673         if (!wblock) {
 674                 strcat(buf, "\n");
 675                 return strlen(buf);
 676         }
 677
 678         wmi_gtoa(wblock->gblock.guid, guid_string);
 679
 680         return sprintf(buf, "wmi:%s\n", guid_string);
 681 }
 682 static DEVICE_ATTR_RO(modalias);
 683
 684 static struct attribute *wmi_attrs[] = {
 685         &dev_attr_modalias.attr,
 686         NULL,
 687 };
 688 ATTRIBUTE_GROUPS(wmi);
 689
 690 static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 691 {
 692         char guid_string[37];
 693
 694         struct wmi_block *wblock;
 695
 696         if (add_uevent_var(env, "MODALIAS="))
 697                 return -ENOMEM;
 698
 699         wblock = dev_get_drvdata(dev);
 700         if (!wblock)
 701                 return -ENOMEM;
 702
 703         wmi_gtoa(wblock->gblock.guid, guid_string);
 704
 705         strcpy(&env->buf[env->buflen - 1], "wmi:");
 706         memcpy(&env->buf[env->buflen - 1 + 4], guid_string, 36);
 707         env->buflen += 40;
 708
 709         return 0;
 710 }
 711
 712 static void wmi_dev_free(struct device *dev)
 713 {
 714         struct wmi_block *wmi_block = container_of(dev, struct wmi_block, dev);
 715
 716         kfree(wmi_block);
 717 }
 718
 719 static struct class wmi_class = {
 720         .name = "wmi",
 721         .dev_release = wmi_dev_free,
 722         .dev_uevent = wmi_dev_uevent,
 723         .dev_groups = wmi_groups,
 724 };
 725
 726 static int wmi_create_device(const struct guid_block *gblock,
 727                              struct wmi_block *wblock, acpi_handle handle)
 728 {
 729         char guid_string[37];
 730
 731         wblock->dev.class = &wmi_class;
 732
 733         wmi_gtoa(gblock->guid, guid_string);
 734         dev_set_name(&wblock->dev, "%s", guid_string);
 735
 736         dev_set_drvdata(&wblock->dev, wblock);
 737
 738         return device_register(&wblock->dev);
 739 }
 740
 741 static void wmi_free_devices(void)
 742 {
 743         struct wmi_block *wblock, *next;
 744
 745         /* Delete devices for all the GUIDs */
 746         list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
 747                 list_del(&wblock->list);
 748                 if (wblock->dev.class)
 749                         device_unregister(&wblock->dev);
 750                 else
 751                         kfree(wblock);
 752         }
 753 }
 754
 755 static bool guid_already_parsed(const char *guid_string)
 756 {
 757         struct wmi_block *wblock;
 758
 759         list_for_each_entry(wblock, &wmi_block_list, list)
 760                 if (memcmp(wblock->gblock.guid, guid_string, 16) == 0)
 761                         return true;
 762
 763         return false;
 764 }
 765
 766 /*
 767  * Parse the _WDG method for the GUID data blocks
 768  */
 769 static int parse_wdg(acpi_handle handle)
 770 {
 771         struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
 772         union acpi_object *obj;
 773         const struct guid_block *gblock;
 774         struct wmi_block *wblock;
 775         acpi_status status;
 776         int retval;
 777         u32 i, total;
 778
 779         status = acpi_evaluate_object(handle, "_WDG", NULL, &out);
 780         if (ACPI_FAILURE(status))
 781                 return -ENXIO;
 782
 783         obj = (union acpi_object *) out.pointer;
 784         if (!obj)
 785                 return -ENXIO;
 786
 787         if (obj->type != ACPI_TYPE_BUFFER) {
 788                 retval = -ENXIO;
 789                 goto out_free_pointer;
 790         }
 791
 792         gblock = (const struct guid_block *)obj->buffer.pointer;
 793         total = obj->buffer.length / sizeof(struct guid_block);
 794
 795         for (i = 0; i < total; i++) {
 796                 if (debug_dump_wdg)
 797                         wmi_dump_wdg(&gblock[i]);
 798
 799                 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
 800                 if (!wblock)
 801                         return -ENOMEM;
 802
 803                 wblock->handle = handle;
 804                 wblock->gblock = gblock[i];
 805
 806                 /*
 807                   Some WMI devices, like those for nVidia hooks, have a
 808                   duplicate GUID. It's not clear what we should do in this
 809                   case yet, so for now, we'll just ignore the duplicate
 810                   for device creation.
 811                 */
 812                 if (!guid_already_parsed(gblock[i].guid)) {
 813                         retval = wmi_create_device(&gblock[i], wblock, handle);
 814                         if (retval) {
 815                                 wmi_free_devices();
 816                                 goto out_free_pointer;
 817                         }
 818                 }
 819
 820                 list_add_tail(&wblock->list, &wmi_block_list);
 821
 822                 if (debug_event) {
 823                         wblock->handler = wmi_notify_debug;
 824                         wmi_method_enable(wblock, 1);
 825                 }
 826         }
 827
 828         retval = 0;
 829
 830 out_free_pointer:
 831         kfree(out.pointer);
 832
 833         return retval;
 834 }
 835
 836 /*
 837  * WMI can have EmbeddedControl access regions. In which case, we just want to
 838  * hand these off to the EC driver.
 839  */
 840 static acpi_status
 841 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
 842                       u32 bits, u64 *value,
 843                       void *handler_context, void *region_context)
 844 {
 845         int result = 0, i = 0;
 846         u8 temp = 0;
 847
 848         if ((address > 0xFF) || !value)
 849                 return AE_BAD_PARAMETER;
 850
 851         if (function != ACPI_READ && function != ACPI_WRITE)
 852                 return AE_BAD_PARAMETER;
 853
 854         if (bits != 8)
 855                 return AE_BAD_PARAMETER;
 856
 857         if (function == ACPI_READ) {
 858                 result = ec_read(address, &temp);
 859                 (*value) |= ((u64)temp) << i;
 860         } else {
 861                 temp = 0xff & ((*value) >> i);
 862                 result = ec_write(address, temp);
 863         }
 864
 865         switch (result) {
 866         case -EINVAL:
 867                 return AE_BAD_PARAMETER;
 868                 break;
 869         case -ENODEV:
 870                 return AE_NOT_FOUND;
 871                 break;
 872         case -ETIME:
 873                 return AE_TIME;
 874                 break;
 875         default:
 876                 return AE_OK;
 877         }
 878 }
 879
 880 static void acpi_wmi_notify(struct acpi_device *device, u32 event)
 881 {
 882         struct guid_block *block;
 883         struct wmi_block *wblock;
 884         struct list_head *p;
 885         char guid_string[37];
 886
 887         list_for_each(p, &wmi_block_list) {
 888                 wblock = list_entry(p, struct wmi_block, list);
 889                 block = &wblock->gblock;
 890
 891                 if ((block->flags & ACPI_WMI_EVENT) &&
 892                         (block->notify_id == event)) {
 893                         if (wblock->handler)
 894                                 wblock->handler(event, wblock->handler_data);
 895                         if (debug_event) {
 896                                 wmi_gtoa(wblock->gblock.guid, guid_string);
 897                                 pr_info("DEBUG Event GUID: %s\n", guid_string);
 898                         }
 899
 900                         acpi_bus_generate_netlink_event(
 901                                 device->pnp.device_class, dev_name(&device->dev),
 902                                 event, 0);
 903                         break;
 904                 }
 905         }
 906 }
 907
 908 static int acpi_wmi_remove(struct acpi_device *device)
 909 {
 910         acpi_remove_address_space_handler(device->handle,
 911                                 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
 912         wmi_free_devices();
 913
 914         return 0;
 915 }
 916
 917 static int acpi_wmi_add(struct acpi_device *device)
 918 {
 919         acpi_status status;
 920         int error;
 921
 922         status = acpi_install_address_space_handler(device->handle,
 923                                                     ACPI_ADR_SPACE_EC,
 924                                                     &acpi_wmi_ec_space_handler,
 925                                                     NULL, NULL);
 926         if (ACPI_FAILURE(status)) {
 927                 pr_err("Error installing EC region handler\n");
 928                 return -ENODEV;
 929         }
 930
 931         error = parse_wdg(device->handle);
 932         if (error) {
 933                 acpi_remove_address_space_handler(device->handle,
 934                                                   ACPI_ADR_SPACE_EC,
 935                                                   &acpi_wmi_ec_space_handler);
 936                 pr_err("Failed to parse WDG method\n");
 937                 return error;
 938         }
 939
 940         return 0;
 941 }
 942
 943 static int __init acpi_wmi_init(void)
 944 {
 945         int error;
 946
 947         if (acpi_disabled)
 948                 return -ENODEV;
 949
 950         error = class_register(&wmi_class);
 951         if (error)
 952                 return error;
 953
 954         error = acpi_bus_register_driver(&acpi_wmi_driver);
 955         if (error) {
 956                 pr_err("Error loading mapper\n");
 957                 class_unregister(&wmi_class);
 958                 return error;
 959         }
 960
 961         pr_info("Mapper loaded\n");
 962         return 0;
 963 }
 964
 965 static void __exit acpi_wmi_exit(void)
 966 {
 967         acpi_bus_unregister_driver(&acpi_wmi_driver);
 968         class_unregister(&wmi_class);
 969
 970         pr_info("Mapper unloaded\n");
 971 }
 972
 973 subsys_initcall(acpi_wmi_init);
 974 module_exit(acpi_wmi_exit);