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