1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * ACPI-WMI mapping driver 4 * 5 * Copyright (C) 2007-2008 Carlos Corbacho <carlos@strangeworlds.co.uk> 6 * 7 * GUID parsing code from ldm.c is: 8 * Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org> 9 * Copyright (c) 2001-2007 Anton Altaparmakov 10 * Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com> 11 * 12 * WMI bus infrastructure by Andrew Lutomirski and Darren Hart: 13 * Copyright (C) 2015 Andrew Lutomirski 14 * Copyright (C) 2017 VMware, Inc. All Rights Reserved. 15 */ 16 17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 18 19 #include <linux/acpi.h> 20 #include <linux/device.h> 21 #include <linux/init.h> 22 #include <linux/kernel.h> 23 #include <linux/list.h> 24 #include <linux/miscdevice.h> 25 #include <linux/module.h> 26 #include <linux/platform_device.h> 27 #include <linux/slab.h> 28 #include <linux/types.h> 29 #include <linux/uaccess.h> 30 #include <linux/uuid.h> 31 #include <linux/wmi.h> 32 #include <linux/fs.h> 33 #include <uapi/linux/wmi.h> 34 35 MODULE_AUTHOR("Carlos Corbacho"); 36 MODULE_DESCRIPTION("ACPI-WMI Mapping Driver"); 37 MODULE_LICENSE("GPL"); 38 39 static LIST_HEAD(wmi_block_list); 40 41 struct guid_block { 42 char guid[16]; 43 union { 44 char object_id[2]; 45 struct { 46 unsigned char notify_id; 47 unsigned char reserved; 48 }; 49 }; 50 u8 instance_count; 51 u8 flags; 52 }; 53 54 struct wmi_block { 55 struct wmi_device dev; 56 struct list_head list; 57 struct guid_block gblock; 58 struct miscdevice char_dev; 59 struct mutex char_mutex; 60 struct acpi_device *acpi_device; 61 wmi_notify_handler handler; 62 void *handler_data; 63 u64 req_buf_size; 64 65 bool read_takes_no_args; 66 }; 67 68 69 /* 70 * If the GUID data block is marked as expensive, we must enable and 71 * explicitily disable data collection. 72 */ 73 #define ACPI_WMI_EXPENSIVE 0x1 74 #define ACPI_WMI_METHOD 0x2 /* GUID is a method */ 75 #define ACPI_WMI_STRING 0x4 /* GUID takes & returns a string */ 76 #define ACPI_WMI_EVENT 0x8 /* GUID is an event */ 77 78 static bool debug_event; 79 module_param(debug_event, bool, 0444); 80 MODULE_PARM_DESC(debug_event, 81 "Log WMI Events [0/1]"); 82 83 static bool debug_dump_wdg; 84 module_param(debug_dump_wdg, bool, 0444); 85 MODULE_PARM_DESC(debug_dump_wdg, 86 "Dump available WMI interfaces [0/1]"); 87 88 static int acpi_wmi_remove(struct platform_device *device); 89 static int acpi_wmi_probe(struct platform_device *device); 90 91 static const struct acpi_device_id wmi_device_ids[] = { 92 {"PNP0C14", 0}, 93 {"pnp0c14", 0}, 94 {"", 0}, 95 }; 96 MODULE_DEVICE_TABLE(acpi, wmi_device_ids); 97 98 static struct platform_driver acpi_wmi_driver = { 99 .driver = { 100 .name = "acpi-wmi", 101 .acpi_match_table = wmi_device_ids, 102 }, 103 .probe = acpi_wmi_probe, 104 .remove = acpi_wmi_remove, 105 }; 106 107 /* 108 * GUID parsing functions 109 */ 110 111 static bool find_guid(const char *guid_string, struct wmi_block **out) 112 { 113 guid_t guid_input; 114 struct wmi_block *wblock; 115 struct guid_block *block; 116 117 if (guid_parse(guid_string, &guid_input)) 118 return false; 119 120 list_for_each_entry(wblock, &wmi_block_list, list) { 121 block = &wblock->gblock; 122 123 if (memcmp(block->guid, &guid_input, 16) == 0) { 124 if (out) 125 *out = wblock; 126 return true; 127 } 128 } 129 return false; 130 } 131 132 static const void *find_guid_context(struct wmi_block *wblock, 133 struct wmi_driver *wdriver) 134 { 135 const struct wmi_device_id *id; 136 guid_t guid_input; 137 138 if (wblock == NULL || wdriver == NULL) 139 return NULL; 140 if (wdriver->id_table == NULL) 141 return NULL; 142 143 id = wdriver->id_table; 144 while (*id->guid_string) { 145 if (guid_parse(id->guid_string, &guid_input)) 146 continue; 147 if (!memcmp(wblock->gblock.guid, &guid_input, 16)) 148 return id->context; 149 id++; 150 } 151 return NULL; 152 } 153 154 static int get_subobj_info(acpi_handle handle, const char *pathname, 155 struct acpi_device_info **info) 156 { 157 struct acpi_device_info *dummy_info, **info_ptr; 158 acpi_handle subobj_handle; 159 acpi_status status; 160 161 status = acpi_get_handle(handle, (char *)pathname, &subobj_handle); 162 if (status == AE_NOT_FOUND) 163 return -ENOENT; 164 else if (ACPI_FAILURE(status)) 165 return -EIO; 166 167 info_ptr = info ? info : &dummy_info; 168 status = acpi_get_object_info(subobj_handle, info_ptr); 169 if (ACPI_FAILURE(status)) 170 return -EIO; 171 172 if (!info) 173 kfree(dummy_info); 174 175 return 0; 176 } 177 178 static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable) 179 { 180 struct guid_block *block = NULL; 181 char method[5]; 182 acpi_status status; 183 acpi_handle handle; 184 185 block = &wblock->gblock; 186 handle = wblock->acpi_device->handle; 187 188 snprintf(method, 5, "WE%02X", block->notify_id); 189 status = acpi_execute_simple_method(handle, method, enable); 190 191 if (status != AE_OK && status != AE_NOT_FOUND) 192 return status; 193 else 194 return AE_OK; 195 } 196 197 /* 198 * Exported WMI functions 199 */ 200 201 /** 202 * set_required_buffer_size - Sets the buffer size needed for performing IOCTL 203 * @wdev: A wmi bus device from a driver 204 * @length: Required buffer size 205 * 206 * Allocates memory needed for buffer, stores the buffer size in that memory 207 */ 208 int set_required_buffer_size(struct wmi_device *wdev, u64 length) 209 { 210 struct wmi_block *wblock; 211 212 wblock = container_of(wdev, struct wmi_block, dev); 213 wblock->req_buf_size = length; 214 215 return 0; 216 } 217 EXPORT_SYMBOL_GPL(set_required_buffer_size); 218 219 /** 220 * wmi_evaluate_method - Evaluate a WMI method 221 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba 222 * @instance: Instance index 223 * @method_id: Method ID to call 224 * @in: Buffer containing input for the method call 225 * @out: Empty buffer to return the method results 226 * 227 * Call an ACPI-WMI method 228 */ 229 acpi_status wmi_evaluate_method(const char *guid_string, u8 instance, 230 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out) 231 { 232 struct wmi_block *wblock = NULL; 233 234 if (!find_guid(guid_string, &wblock)) 235 return AE_ERROR; 236 return wmidev_evaluate_method(&wblock->dev, instance, method_id, 237 in, out); 238 } 239 EXPORT_SYMBOL_GPL(wmi_evaluate_method); 240 241 /** 242 * wmidev_evaluate_method - Evaluate a WMI method 243 * @wdev: A wmi bus device from a driver 244 * @instance: Instance index 245 * @method_id: Method ID to call 246 * @in: Buffer containing input for the method call 247 * @out: Empty buffer to return the method results 248 * 249 * Call an ACPI-WMI method 250 */ 251 acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance, 252 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out) 253 { 254 struct guid_block *block = NULL; 255 struct wmi_block *wblock = NULL; 256 acpi_handle handle; 257 acpi_status status; 258 struct acpi_object_list input; 259 union acpi_object params[3]; 260 char method[5] = "WM"; 261 262 wblock = container_of(wdev, struct wmi_block, dev); 263 block = &wblock->gblock; 264 handle = wblock->acpi_device->handle; 265 266 if (!(block->flags & ACPI_WMI_METHOD)) 267 return AE_BAD_DATA; 268 269 if (block->instance_count <= instance) 270 return AE_BAD_PARAMETER; 271 272 input.count = 2; 273 input.pointer = params; 274 params[0].type = ACPI_TYPE_INTEGER; 275 params[0].integer.value = instance; 276 params[1].type = ACPI_TYPE_INTEGER; 277 params[1].integer.value = method_id; 278 279 if (in) { 280 input.count = 3; 281 282 if (block->flags & ACPI_WMI_STRING) { 283 params[2].type = ACPI_TYPE_STRING; 284 } else { 285 params[2].type = ACPI_TYPE_BUFFER; 286 } 287 params[2].buffer.length = in->length; 288 params[2].buffer.pointer = in->pointer; 289 } 290 291 strncat(method, block->object_id, 2); 292 293 status = acpi_evaluate_object(handle, method, &input, out); 294 295 return status; 296 } 297 EXPORT_SYMBOL_GPL(wmidev_evaluate_method); 298 299 static acpi_status __query_block(struct wmi_block *wblock, u8 instance, 300 struct acpi_buffer *out) 301 { 302 struct guid_block *block = NULL; 303 acpi_handle handle; 304 acpi_status status, wc_status = AE_ERROR; 305 struct acpi_object_list input; 306 union acpi_object wq_params[1]; 307 char method[5]; 308 char wc_method[5] = "WC"; 309 310 if (!out) 311 return AE_BAD_PARAMETER; 312 313 block = &wblock->gblock; 314 handle = wblock->acpi_device->handle; 315 316 if (block->instance_count <= instance) 317 return AE_BAD_PARAMETER; 318 319 /* Check GUID is a data block */ 320 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD)) 321 return AE_ERROR; 322 323 input.count = 1; 324 input.pointer = wq_params; 325 wq_params[0].type = ACPI_TYPE_INTEGER; 326 wq_params[0].integer.value = instance; 327 328 if (instance == 0 && wblock->read_takes_no_args) 329 input.count = 0; 330 331 /* 332 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to 333 * enable collection. 334 */ 335 if (block->flags & ACPI_WMI_EXPENSIVE) { 336 strncat(wc_method, block->object_id, 2); 337 338 /* 339 * Some GUIDs break the specification by declaring themselves 340 * expensive, but have no corresponding WCxx method. So we 341 * should not fail if this happens. 342 */ 343 wc_status = acpi_execute_simple_method(handle, wc_method, 1); 344 } 345 346 strcpy(method, "WQ"); 347 strncat(method, block->object_id, 2); 348 349 status = acpi_evaluate_object(handle, method, &input, out); 350 351 /* 352 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if 353 * the WQxx method failed - we should disable collection anyway. 354 */ 355 if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) { 356 status = acpi_execute_simple_method(handle, wc_method, 0); 357 } 358 359 return status; 360 } 361 362 /** 363 * wmi_query_block - Return contents of a WMI block (deprecated) 364 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba 365 * @instance: Instance index 366 * @out: Empty buffer to return the contents of the data block to 367 * 368 * Return the contents of an ACPI-WMI data block to a buffer 369 */ 370 acpi_status wmi_query_block(const char *guid_string, u8 instance, 371 struct acpi_buffer *out) 372 { 373 struct wmi_block *wblock; 374 375 if (!guid_string) 376 return AE_BAD_PARAMETER; 377 378 if (!find_guid(guid_string, &wblock)) 379 return AE_ERROR; 380 381 return __query_block(wblock, instance, out); 382 } 383 EXPORT_SYMBOL_GPL(wmi_query_block); 384 385 union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance) 386 { 387 struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL }; 388 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev); 389 390 if (ACPI_FAILURE(__query_block(wblock, instance, &out))) 391 return NULL; 392 393 return (union acpi_object *)out.pointer; 394 } 395 EXPORT_SYMBOL_GPL(wmidev_block_query); 396 397 /** 398 * wmi_set_block - Write to a WMI block 399 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba 400 * @instance: Instance index 401 * @in: Buffer containing new values for the data block 402 * 403 * Write the contents of the input buffer to an ACPI-WMI data block 404 */ 405 acpi_status wmi_set_block(const char *guid_string, u8 instance, 406 const struct acpi_buffer *in) 407 { 408 struct guid_block *block = NULL; 409 struct wmi_block *wblock = NULL; 410 acpi_handle handle; 411 struct acpi_object_list input; 412 union acpi_object params[2]; 413 char method[5] = "WS"; 414 415 if (!guid_string || !in) 416 return AE_BAD_DATA; 417 418 if (!find_guid(guid_string, &wblock)) 419 return AE_ERROR; 420 421 block = &wblock->gblock; 422 handle = wblock->acpi_device->handle; 423 424 if (block->instance_count <= instance) 425 return AE_BAD_PARAMETER; 426 427 /* Check GUID is a data block */ 428 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD)) 429 return AE_ERROR; 430 431 input.count = 2; 432 input.pointer = params; 433 params[0].type = ACPI_TYPE_INTEGER; 434 params[0].integer.value = instance; 435 436 if (block->flags & ACPI_WMI_STRING) { 437 params[1].type = ACPI_TYPE_STRING; 438 } else { 439 params[1].type = ACPI_TYPE_BUFFER; 440 } 441 params[1].buffer.length = in->length; 442 params[1].buffer.pointer = in->pointer; 443 444 strncat(method, block->object_id, 2); 445 446 return acpi_evaluate_object(handle, method, &input, NULL); 447 } 448 EXPORT_SYMBOL_GPL(wmi_set_block); 449 450 static void wmi_dump_wdg(const struct guid_block *g) 451 { 452 pr_info("%pUL:\n", g->guid); 453 if (g->flags & ACPI_WMI_EVENT) 454 pr_info("\tnotify_id: 0x%02X\n", g->notify_id); 455 else 456 pr_info("\tobject_id: %2pE\n", g->object_id); 457 pr_info("\tinstance_count: %d\n", g->instance_count); 458 pr_info("\tflags: %#x", g->flags); 459 if (g->flags) { 460 if (g->flags & ACPI_WMI_EXPENSIVE) 461 pr_cont(" ACPI_WMI_EXPENSIVE"); 462 if (g->flags & ACPI_WMI_METHOD) 463 pr_cont(" ACPI_WMI_METHOD"); 464 if (g->flags & ACPI_WMI_STRING) 465 pr_cont(" ACPI_WMI_STRING"); 466 if (g->flags & ACPI_WMI_EVENT) 467 pr_cont(" ACPI_WMI_EVENT"); 468 } 469 pr_cont("\n"); 470 471 } 472 473 static void wmi_notify_debug(u32 value, void *context) 474 { 475 struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL }; 476 union acpi_object *obj; 477 acpi_status status; 478 479 status = wmi_get_event_data(value, &response); 480 if (status != AE_OK) { 481 pr_info("bad event status 0x%x\n", status); 482 return; 483 } 484 485 obj = (union acpi_object *)response.pointer; 486 487 if (!obj) 488 return; 489 490 pr_info("DEBUG Event "); 491 switch(obj->type) { 492 case ACPI_TYPE_BUFFER: 493 pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length); 494 break; 495 case ACPI_TYPE_STRING: 496 pr_cont("STRING_TYPE - %s\n", obj->string.pointer); 497 break; 498 case ACPI_TYPE_INTEGER: 499 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value); 500 break; 501 case ACPI_TYPE_PACKAGE: 502 pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count); 503 break; 504 default: 505 pr_cont("object type 0x%X\n", obj->type); 506 } 507 kfree(obj); 508 } 509 510 /** 511 * wmi_install_notify_handler - Register handler for WMI events 512 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba 513 * @handler: Function to handle notifications 514 * @data: Data to be returned to handler when event is fired 515 * 516 * Register a handler for events sent to the ACPI-WMI mapper device. 517 */ 518 acpi_status wmi_install_notify_handler(const char *guid, 519 wmi_notify_handler handler, void *data) 520 { 521 struct wmi_block *block; 522 acpi_status status = AE_NOT_EXIST; 523 guid_t guid_input; 524 525 if (!guid || !handler) 526 return AE_BAD_PARAMETER; 527 528 if (guid_parse(guid, &guid_input)) 529 return AE_BAD_PARAMETER; 530 531 list_for_each_entry(block, &wmi_block_list, list) { 532 acpi_status wmi_status; 533 534 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) { 535 if (block->handler && 536 block->handler != wmi_notify_debug) 537 return AE_ALREADY_ACQUIRED; 538 539 block->handler = handler; 540 block->handler_data = data; 541 542 wmi_status = wmi_method_enable(block, 1); 543 if ((wmi_status != AE_OK) || 544 ((wmi_status == AE_OK) && (status == AE_NOT_EXIST))) 545 status = wmi_status; 546 } 547 } 548 549 return status; 550 } 551 EXPORT_SYMBOL_GPL(wmi_install_notify_handler); 552 553 /** 554 * wmi_uninstall_notify_handler - Unregister handler for WMI events 555 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba 556 * 557 * Unregister handler for events sent to the ACPI-WMI mapper device. 558 */ 559 acpi_status wmi_remove_notify_handler(const char *guid) 560 { 561 struct wmi_block *block; 562 acpi_status status = AE_NOT_EXIST; 563 guid_t guid_input; 564 565 if (!guid) 566 return AE_BAD_PARAMETER; 567 568 if (guid_parse(guid, &guid_input)) 569 return AE_BAD_PARAMETER; 570 571 list_for_each_entry(block, &wmi_block_list, list) { 572 acpi_status wmi_status; 573 574 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) { 575 if (!block->handler || 576 block->handler == wmi_notify_debug) 577 return AE_NULL_ENTRY; 578 579 if (debug_event) { 580 block->handler = wmi_notify_debug; 581 status = AE_OK; 582 } else { 583 wmi_status = wmi_method_enable(block, 0); 584 block->handler = NULL; 585 block->handler_data = NULL; 586 if ((wmi_status != AE_OK) || 587 ((wmi_status == AE_OK) && 588 (status == AE_NOT_EXIST))) 589 status = wmi_status; 590 } 591 } 592 } 593 594 return status; 595 } 596 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler); 597 598 /** 599 * wmi_get_event_data - Get WMI data associated with an event 600 * 601 * @event: Event to find 602 * @out: Buffer to hold event data. out->pointer should be freed with kfree() 603 * 604 * Returns extra data associated with an event in WMI. 605 */ 606 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out) 607 { 608 struct acpi_object_list input; 609 union acpi_object params[1]; 610 struct guid_block *gblock; 611 struct wmi_block *wblock; 612 613 input.count = 1; 614 input.pointer = params; 615 params[0].type = ACPI_TYPE_INTEGER; 616 params[0].integer.value = event; 617 618 list_for_each_entry(wblock, &wmi_block_list, list) { 619 gblock = &wblock->gblock; 620 621 if ((gblock->flags & ACPI_WMI_EVENT) && 622 (gblock->notify_id == event)) 623 return acpi_evaluate_object(wblock->acpi_device->handle, 624 "_WED", &input, out); 625 } 626 627 return AE_NOT_FOUND; 628 } 629 EXPORT_SYMBOL_GPL(wmi_get_event_data); 630 631 /** 632 * wmi_has_guid - Check if a GUID is available 633 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba 634 * 635 * Check if a given GUID is defined by _WDG 636 */ 637 bool wmi_has_guid(const char *guid_string) 638 { 639 return find_guid(guid_string, NULL); 640 } 641 EXPORT_SYMBOL_GPL(wmi_has_guid); 642 643 /** 644 * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID 645 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba 646 * 647 * Find the _UID of ACPI device associated with this WMI GUID. 648 * 649 * Return: The ACPI _UID field value or NULL if the WMI GUID was not found 650 */ 651 char *wmi_get_acpi_device_uid(const char *guid_string) 652 { 653 struct wmi_block *wblock = NULL; 654 655 if (!find_guid(guid_string, &wblock)) 656 return NULL; 657 658 return acpi_device_uid(wblock->acpi_device); 659 } 660 EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid); 661 662 static struct wmi_block *dev_to_wblock(struct device *dev) 663 { 664 return container_of(dev, struct wmi_block, dev.dev); 665 } 666 667 static struct wmi_device *dev_to_wdev(struct device *dev) 668 { 669 return container_of(dev, struct wmi_device, dev); 670 } 671 672 /* 673 * sysfs interface 674 */ 675 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, 676 char *buf) 677 { 678 struct wmi_block *wblock = dev_to_wblock(dev); 679 680 return sprintf(buf, "wmi:%pUL\n", wblock->gblock.guid); 681 } 682 static DEVICE_ATTR_RO(modalias); 683 684 static ssize_t guid_show(struct device *dev, struct device_attribute *attr, 685 char *buf) 686 { 687 struct wmi_block *wblock = dev_to_wblock(dev); 688 689 return sprintf(buf, "%pUL\n", wblock->gblock.guid); 690 } 691 static DEVICE_ATTR_RO(guid); 692 693 static ssize_t instance_count_show(struct device *dev, 694 struct device_attribute *attr, char *buf) 695 { 696 struct wmi_block *wblock = dev_to_wblock(dev); 697 698 return sprintf(buf, "%d\n", (int)wblock->gblock.instance_count); 699 } 700 static DEVICE_ATTR_RO(instance_count); 701 702 static ssize_t expensive_show(struct device *dev, 703 struct device_attribute *attr, char *buf) 704 { 705 struct wmi_block *wblock = dev_to_wblock(dev); 706 707 return sprintf(buf, "%d\n", 708 (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0); 709 } 710 static DEVICE_ATTR_RO(expensive); 711 712 static struct attribute *wmi_attrs[] = { 713 &dev_attr_modalias.attr, 714 &dev_attr_guid.attr, 715 &dev_attr_instance_count.attr, 716 &dev_attr_expensive.attr, 717 NULL, 718 }; 719 ATTRIBUTE_GROUPS(wmi); 720 721 static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr, 722 char *buf) 723 { 724 struct wmi_block *wblock = dev_to_wblock(dev); 725 726 return sprintf(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id); 727 } 728 static DEVICE_ATTR_RO(notify_id); 729 730 static struct attribute *wmi_event_attrs[] = { 731 &dev_attr_notify_id.attr, 732 NULL, 733 }; 734 ATTRIBUTE_GROUPS(wmi_event); 735 736 static ssize_t object_id_show(struct device *dev, struct device_attribute *attr, 737 char *buf) 738 { 739 struct wmi_block *wblock = dev_to_wblock(dev); 740 741 return sprintf(buf, "%c%c\n", wblock->gblock.object_id[0], 742 wblock->gblock.object_id[1]); 743 } 744 static DEVICE_ATTR_RO(object_id); 745 746 static ssize_t setable_show(struct device *dev, struct device_attribute *attr, 747 char *buf) 748 { 749 struct wmi_device *wdev = dev_to_wdev(dev); 750 751 return sprintf(buf, "%d\n", (int)wdev->setable); 752 } 753 static DEVICE_ATTR_RO(setable); 754 755 static struct attribute *wmi_data_attrs[] = { 756 &dev_attr_object_id.attr, 757 &dev_attr_setable.attr, 758 NULL, 759 }; 760 ATTRIBUTE_GROUPS(wmi_data); 761 762 static struct attribute *wmi_method_attrs[] = { 763 &dev_attr_object_id.attr, 764 NULL, 765 }; 766 ATTRIBUTE_GROUPS(wmi_method); 767 768 static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env) 769 { 770 struct wmi_block *wblock = dev_to_wblock(dev); 771 772 if (add_uevent_var(env, "MODALIAS=wmi:%pUL", wblock->gblock.guid)) 773 return -ENOMEM; 774 775 if (add_uevent_var(env, "WMI_GUID=%pUL", wblock->gblock.guid)) 776 return -ENOMEM; 777 778 return 0; 779 } 780 781 static void wmi_dev_release(struct device *dev) 782 { 783 struct wmi_block *wblock = dev_to_wblock(dev); 784 785 kfree(wblock); 786 } 787 788 static int wmi_dev_match(struct device *dev, struct device_driver *driver) 789 { 790 struct wmi_driver *wmi_driver = 791 container_of(driver, struct wmi_driver, driver); 792 struct wmi_block *wblock = dev_to_wblock(dev); 793 const struct wmi_device_id *id = wmi_driver->id_table; 794 795 if (id == NULL) 796 return 0; 797 798 while (*id->guid_string) { 799 guid_t driver_guid; 800 801 if (WARN_ON(guid_parse(id->guid_string, &driver_guid))) 802 continue; 803 if (!memcmp(&driver_guid, wblock->gblock.guid, 16)) 804 return 1; 805 806 id++; 807 } 808 809 return 0; 810 } 811 static int wmi_char_open(struct inode *inode, struct file *filp) 812 { 813 const char *driver_name = filp->f_path.dentry->d_iname; 814 struct wmi_block *wblock = NULL; 815 struct wmi_block *next = NULL; 816 817 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) { 818 if (!wblock->dev.dev.driver) 819 continue; 820 if (strcmp(driver_name, wblock->dev.dev.driver->name) == 0) { 821 filp->private_data = wblock; 822 break; 823 } 824 } 825 826 if (!filp->private_data) 827 return -ENODEV; 828 829 return nonseekable_open(inode, filp); 830 } 831 832 static ssize_t wmi_char_read(struct file *filp, char __user *buffer, 833 size_t length, loff_t *offset) 834 { 835 struct wmi_block *wblock = filp->private_data; 836 837 return simple_read_from_buffer(buffer, length, offset, 838 &wblock->req_buf_size, 839 sizeof(wblock->req_buf_size)); 840 } 841 842 static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 843 { 844 struct wmi_ioctl_buffer __user *input = 845 (struct wmi_ioctl_buffer __user *) arg; 846 struct wmi_block *wblock = filp->private_data; 847 struct wmi_ioctl_buffer *buf = NULL; 848 struct wmi_driver *wdriver = NULL; 849 int ret; 850 851 if (_IOC_TYPE(cmd) != WMI_IOC) 852 return -ENOTTY; 853 854 /* make sure we're not calling a higher instance than exists*/ 855 if (_IOC_NR(cmd) >= wblock->gblock.instance_count) 856 return -EINVAL; 857 858 mutex_lock(&wblock->char_mutex); 859 buf = wblock->handler_data; 860 if (get_user(buf->length, &input->length)) { 861 dev_dbg(&wblock->dev.dev, "Read length from user failed\n"); 862 ret = -EFAULT; 863 goto out_ioctl; 864 } 865 /* if it's too small, abort */ 866 if (buf->length < wblock->req_buf_size) { 867 dev_err(&wblock->dev.dev, 868 "Buffer %lld too small, need at least %lld\n", 869 buf->length, wblock->req_buf_size); 870 ret = -EINVAL; 871 goto out_ioctl; 872 } 873 /* if it's too big, warn, driver will only use what is needed */ 874 if (buf->length > wblock->req_buf_size) 875 dev_warn(&wblock->dev.dev, 876 "Buffer %lld is bigger than required %lld\n", 877 buf->length, wblock->req_buf_size); 878 879 /* copy the structure from userspace */ 880 if (copy_from_user(buf, input, wblock->req_buf_size)) { 881 dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n", 882 wblock->req_buf_size); 883 ret = -EFAULT; 884 goto out_ioctl; 885 } 886 887 /* let the driver do any filtering and do the call */ 888 wdriver = container_of(wblock->dev.dev.driver, 889 struct wmi_driver, driver); 890 if (!try_module_get(wdriver->driver.owner)) { 891 ret = -EBUSY; 892 goto out_ioctl; 893 } 894 ret = wdriver->filter_callback(&wblock->dev, cmd, buf); 895 module_put(wdriver->driver.owner); 896 if (ret) 897 goto out_ioctl; 898 899 /* return the result (only up to our internal buffer size) */ 900 if (copy_to_user(input, buf, wblock->req_buf_size)) { 901 dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n", 902 wblock->req_buf_size); 903 ret = -EFAULT; 904 } 905 906 out_ioctl: 907 mutex_unlock(&wblock->char_mutex); 908 return ret; 909 } 910 911 static const struct file_operations wmi_fops = { 912 .owner = THIS_MODULE, 913 .read = wmi_char_read, 914 .open = wmi_char_open, 915 .unlocked_ioctl = wmi_ioctl, 916 .compat_ioctl = compat_ptr_ioctl, 917 }; 918 919 static int wmi_dev_probe(struct device *dev) 920 { 921 struct wmi_block *wblock = dev_to_wblock(dev); 922 struct wmi_driver *wdriver = 923 container_of(dev->driver, struct wmi_driver, driver); 924 int ret = 0; 925 char *buf; 926 927 if (ACPI_FAILURE(wmi_method_enable(wblock, 1))) 928 dev_warn(dev, "failed to enable device -- probing anyway\n"); 929 930 if (wdriver->probe) { 931 ret = wdriver->probe(dev_to_wdev(dev), 932 find_guid_context(wblock, wdriver)); 933 if (ret != 0) 934 goto probe_failure; 935 } 936 937 /* driver wants a character device made */ 938 if (wdriver->filter_callback) { 939 /* check that required buffer size declared by driver or MOF */ 940 if (!wblock->req_buf_size) { 941 dev_err(&wblock->dev.dev, 942 "Required buffer size not set\n"); 943 ret = -EINVAL; 944 goto probe_failure; 945 } 946 947 wblock->handler_data = kmalloc(wblock->req_buf_size, 948 GFP_KERNEL); 949 if (!wblock->handler_data) { 950 ret = -ENOMEM; 951 goto probe_failure; 952 } 953 954 buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name); 955 if (!buf) { 956 ret = -ENOMEM; 957 goto probe_string_failure; 958 } 959 wblock->char_dev.minor = MISC_DYNAMIC_MINOR; 960 wblock->char_dev.name = buf; 961 wblock->char_dev.fops = &wmi_fops; 962 wblock->char_dev.mode = 0444; 963 ret = misc_register(&wblock->char_dev); 964 if (ret) { 965 dev_warn(dev, "failed to register char dev: %d\n", ret); 966 ret = -ENOMEM; 967 goto probe_misc_failure; 968 } 969 } 970 971 return 0; 972 973 probe_misc_failure: 974 kfree(buf); 975 probe_string_failure: 976 kfree(wblock->handler_data); 977 probe_failure: 978 if (ACPI_FAILURE(wmi_method_enable(wblock, 0))) 979 dev_warn(dev, "failed to disable device\n"); 980 return ret; 981 } 982 983 static int wmi_dev_remove(struct device *dev) 984 { 985 struct wmi_block *wblock = dev_to_wblock(dev); 986 struct wmi_driver *wdriver = 987 container_of(dev->driver, struct wmi_driver, driver); 988 989 if (wdriver->filter_callback) { 990 misc_deregister(&wblock->char_dev); 991 kfree(wblock->char_dev.name); 992 kfree(wblock->handler_data); 993 } 994 995 if (wdriver->remove) 996 wdriver->remove(dev_to_wdev(dev)); 997 998 if (ACPI_FAILURE(wmi_method_enable(wblock, 0))) 999 dev_warn(dev, "failed to disable device\n"); 1000 1001 return 0; 1002 } 1003 1004 static struct class wmi_bus_class = { 1005 .name = "wmi_bus", 1006 }; 1007 1008 static struct bus_type wmi_bus_type = { 1009 .name = "wmi", 1010 .dev_groups = wmi_groups, 1011 .match = wmi_dev_match, 1012 .uevent = wmi_dev_uevent, 1013 .probe = wmi_dev_probe, 1014 .remove = wmi_dev_remove, 1015 }; 1016 1017 static const struct device_type wmi_type_event = { 1018 .name = "event", 1019 .groups = wmi_event_groups, 1020 .release = wmi_dev_release, 1021 }; 1022 1023 static const struct device_type wmi_type_method = { 1024 .name = "method", 1025 .groups = wmi_method_groups, 1026 .release = wmi_dev_release, 1027 }; 1028 1029 static const struct device_type wmi_type_data = { 1030 .name = "data", 1031 .groups = wmi_data_groups, 1032 .release = wmi_dev_release, 1033 }; 1034 1035 static int wmi_create_device(struct device *wmi_bus_dev, 1036 const struct guid_block *gblock, 1037 struct wmi_block *wblock, 1038 struct acpi_device *device) 1039 { 1040 struct acpi_device_info *info; 1041 char method[5]; 1042 int result; 1043 1044 if (gblock->flags & ACPI_WMI_EVENT) { 1045 wblock->dev.dev.type = &wmi_type_event; 1046 goto out_init; 1047 } 1048 1049 if (gblock->flags & ACPI_WMI_METHOD) { 1050 wblock->dev.dev.type = &wmi_type_method; 1051 mutex_init(&wblock->char_mutex); 1052 goto out_init; 1053 } 1054 1055 /* 1056 * Data Block Query Control Method (WQxx by convention) is 1057 * required per the WMI documentation. If it is not present, 1058 * we ignore this data block. 1059 */ 1060 strcpy(method, "WQ"); 1061 strncat(method, wblock->gblock.object_id, 2); 1062 result = get_subobj_info(device->handle, method, &info); 1063 1064 if (result) { 1065 dev_warn(wmi_bus_dev, 1066 "%s data block query control method not found\n", 1067 method); 1068 return result; 1069 } 1070 1071 wblock->dev.dev.type = &wmi_type_data; 1072 1073 /* 1074 * The Microsoft documentation specifically states: 1075 * 1076 * Data blocks registered with only a single instance 1077 * can ignore the parameter. 1078 * 1079 * ACPICA will get mad at us if we call the method with the wrong number 1080 * of arguments, so check what our method expects. (On some Dell 1081 * laptops, WQxx may not be a method at all.) 1082 */ 1083 if (info->type != ACPI_TYPE_METHOD || info->param_count == 0) 1084 wblock->read_takes_no_args = true; 1085 1086 kfree(info); 1087 1088 strcpy(method, "WS"); 1089 strncat(method, wblock->gblock.object_id, 2); 1090 result = get_subobj_info(device->handle, method, NULL); 1091 1092 if (result == 0) 1093 wblock->dev.setable = true; 1094 1095 out_init: 1096 wblock->dev.dev.bus = &wmi_bus_type; 1097 wblock->dev.dev.parent = wmi_bus_dev; 1098 1099 dev_set_name(&wblock->dev.dev, "%pUL", gblock->guid); 1100 1101 device_initialize(&wblock->dev.dev); 1102 1103 return 0; 1104 } 1105 1106 static void wmi_free_devices(struct acpi_device *device) 1107 { 1108 struct wmi_block *wblock, *next; 1109 1110 /* Delete devices for all the GUIDs */ 1111 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) { 1112 if (wblock->acpi_device == device) { 1113 list_del(&wblock->list); 1114 device_unregister(&wblock->dev.dev); 1115 } 1116 } 1117 } 1118 1119 static bool guid_already_parsed(struct acpi_device *device, const u8 *guid) 1120 { 1121 struct wmi_block *wblock; 1122 1123 list_for_each_entry(wblock, &wmi_block_list, list) { 1124 if (memcmp(wblock->gblock.guid, guid, 16) == 0) { 1125 /* 1126 * Because we historically didn't track the relationship 1127 * between GUIDs and ACPI nodes, we don't know whether 1128 * we need to suppress GUIDs that are unique on a 1129 * given node but duplicated across nodes. 1130 */ 1131 dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n", 1132 guid, dev_name(&wblock->acpi_device->dev)); 1133 return true; 1134 } 1135 } 1136 1137 return false; 1138 } 1139 1140 /* 1141 * Parse the _WDG method for the GUID data blocks 1142 */ 1143 static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device) 1144 { 1145 struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL}; 1146 const struct guid_block *gblock; 1147 struct wmi_block *wblock, *next; 1148 union acpi_object *obj; 1149 acpi_status status; 1150 int retval = 0; 1151 u32 i, total; 1152 1153 status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out); 1154 if (ACPI_FAILURE(status)) 1155 return -ENXIO; 1156 1157 obj = (union acpi_object *) out.pointer; 1158 if (!obj) 1159 return -ENXIO; 1160 1161 if (obj->type != ACPI_TYPE_BUFFER) { 1162 retval = -ENXIO; 1163 goto out_free_pointer; 1164 } 1165 1166 gblock = (const struct guid_block *)obj->buffer.pointer; 1167 total = obj->buffer.length / sizeof(struct guid_block); 1168 1169 for (i = 0; i < total; i++) { 1170 if (debug_dump_wdg) 1171 wmi_dump_wdg(&gblock[i]); 1172 1173 /* 1174 * Some WMI devices, like those for nVidia hooks, have a 1175 * duplicate GUID. It's not clear what we should do in this 1176 * case yet, so for now, we'll just ignore the duplicate 1177 * for device creation. 1178 */ 1179 if (guid_already_parsed(device, gblock[i].guid)) 1180 continue; 1181 1182 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL); 1183 if (!wblock) { 1184 retval = -ENOMEM; 1185 break; 1186 } 1187 1188 wblock->acpi_device = device; 1189 wblock->gblock = gblock[i]; 1190 1191 retval = wmi_create_device(wmi_bus_dev, &gblock[i], wblock, device); 1192 if (retval) { 1193 kfree(wblock); 1194 continue; 1195 } 1196 1197 list_add_tail(&wblock->list, &wmi_block_list); 1198 1199 if (debug_event) { 1200 wblock->handler = wmi_notify_debug; 1201 wmi_method_enable(wblock, 1); 1202 } 1203 } 1204 1205 /* 1206 * Now that all of the devices are created, add them to the 1207 * device tree and probe subdrivers. 1208 */ 1209 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) { 1210 if (wblock->acpi_device != device) 1211 continue; 1212 1213 retval = device_add(&wblock->dev.dev); 1214 if (retval) { 1215 dev_err(wmi_bus_dev, "failed to register %pUL\n", 1216 wblock->gblock.guid); 1217 if (debug_event) 1218 wmi_method_enable(wblock, 0); 1219 list_del(&wblock->list); 1220 put_device(&wblock->dev.dev); 1221 } 1222 } 1223 1224 out_free_pointer: 1225 kfree(out.pointer); 1226 return retval; 1227 } 1228 1229 /* 1230 * WMI can have EmbeddedControl access regions. In which case, we just want to 1231 * hand these off to the EC driver. 1232 */ 1233 static acpi_status 1234 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address, 1235 u32 bits, u64 *value, 1236 void *handler_context, void *region_context) 1237 { 1238 int result = 0, i = 0; 1239 u8 temp = 0; 1240 1241 if ((address > 0xFF) || !value) 1242 return AE_BAD_PARAMETER; 1243 1244 if (function != ACPI_READ && function != ACPI_WRITE) 1245 return AE_BAD_PARAMETER; 1246 1247 if (bits != 8) 1248 return AE_BAD_PARAMETER; 1249 1250 if (function == ACPI_READ) { 1251 result = ec_read(address, &temp); 1252 (*value) |= ((u64)temp) << i; 1253 } else { 1254 temp = 0xff & ((*value) >> i); 1255 result = ec_write(address, temp); 1256 } 1257 1258 switch (result) { 1259 case -EINVAL: 1260 return AE_BAD_PARAMETER; 1261 case -ENODEV: 1262 return AE_NOT_FOUND; 1263 case -ETIME: 1264 return AE_TIME; 1265 default: 1266 return AE_OK; 1267 } 1268 } 1269 1270 static void acpi_wmi_notify_handler(acpi_handle handle, u32 event, 1271 void *context) 1272 { 1273 struct guid_block *block; 1274 struct wmi_block *wblock; 1275 bool found_it = false; 1276 1277 list_for_each_entry(wblock, &wmi_block_list, list) { 1278 block = &wblock->gblock; 1279 1280 if (wblock->acpi_device->handle == handle && 1281 (block->flags & ACPI_WMI_EVENT) && 1282 (block->notify_id == event)) 1283 { 1284 found_it = true; 1285 break; 1286 } 1287 } 1288 1289 if (!found_it) 1290 return; 1291 1292 /* If a driver is bound, then notify the driver. */ 1293 if (wblock->dev.dev.driver) { 1294 struct wmi_driver *driver; 1295 struct acpi_object_list input; 1296 union acpi_object params[1]; 1297 struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL }; 1298 acpi_status status; 1299 1300 driver = container_of(wblock->dev.dev.driver, 1301 struct wmi_driver, driver); 1302 1303 input.count = 1; 1304 input.pointer = params; 1305 params[0].type = ACPI_TYPE_INTEGER; 1306 params[0].integer.value = event; 1307 1308 status = acpi_evaluate_object(wblock->acpi_device->handle, 1309 "_WED", &input, &evdata); 1310 if (ACPI_FAILURE(status)) { 1311 dev_warn(&wblock->dev.dev, 1312 "failed to get event data\n"); 1313 return; 1314 } 1315 1316 if (driver->notify) 1317 driver->notify(&wblock->dev, 1318 (union acpi_object *)evdata.pointer); 1319 1320 kfree(evdata.pointer); 1321 } else if (wblock->handler) { 1322 /* Legacy handler */ 1323 wblock->handler(event, wblock->handler_data); 1324 } 1325 1326 if (debug_event) 1327 pr_info("DEBUG Event GUID: %pUL\n", wblock->gblock.guid); 1328 1329 acpi_bus_generate_netlink_event( 1330 wblock->acpi_device->pnp.device_class, 1331 dev_name(&wblock->dev.dev), 1332 event, 0); 1333 1334 } 1335 1336 static int acpi_wmi_remove(struct platform_device *device) 1337 { 1338 struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev); 1339 1340 acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY, 1341 acpi_wmi_notify_handler); 1342 acpi_remove_address_space_handler(acpi_device->handle, 1343 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler); 1344 wmi_free_devices(acpi_device); 1345 device_unregister((struct device *)dev_get_drvdata(&device->dev)); 1346 1347 return 0; 1348 } 1349 1350 static int acpi_wmi_probe(struct platform_device *device) 1351 { 1352 struct acpi_device *acpi_device; 1353 struct device *wmi_bus_dev; 1354 acpi_status status; 1355 int error; 1356 1357 acpi_device = ACPI_COMPANION(&device->dev); 1358 if (!acpi_device) { 1359 dev_err(&device->dev, "ACPI companion is missing\n"); 1360 return -ENODEV; 1361 } 1362 1363 status = acpi_install_address_space_handler(acpi_device->handle, 1364 ACPI_ADR_SPACE_EC, 1365 &acpi_wmi_ec_space_handler, 1366 NULL, NULL); 1367 if (ACPI_FAILURE(status)) { 1368 dev_err(&device->dev, "Error installing EC region handler\n"); 1369 return -ENODEV; 1370 } 1371 1372 status = acpi_install_notify_handler(acpi_device->handle, 1373 ACPI_DEVICE_NOTIFY, 1374 acpi_wmi_notify_handler, 1375 NULL); 1376 if (ACPI_FAILURE(status)) { 1377 dev_err(&device->dev, "Error installing notify handler\n"); 1378 error = -ENODEV; 1379 goto err_remove_ec_handler; 1380 } 1381 1382 wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0), 1383 NULL, "wmi_bus-%s", dev_name(&device->dev)); 1384 if (IS_ERR(wmi_bus_dev)) { 1385 error = PTR_ERR(wmi_bus_dev); 1386 goto err_remove_notify_handler; 1387 } 1388 dev_set_drvdata(&device->dev, wmi_bus_dev); 1389 1390 error = parse_wdg(wmi_bus_dev, acpi_device); 1391 if (error) { 1392 pr_err("Failed to parse WDG method\n"); 1393 goto err_remove_busdev; 1394 } 1395 1396 return 0; 1397 1398 err_remove_busdev: 1399 device_unregister(wmi_bus_dev); 1400 1401 err_remove_notify_handler: 1402 acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY, 1403 acpi_wmi_notify_handler); 1404 1405 err_remove_ec_handler: 1406 acpi_remove_address_space_handler(acpi_device->handle, 1407 ACPI_ADR_SPACE_EC, 1408 &acpi_wmi_ec_space_handler); 1409 1410 return error; 1411 } 1412 1413 int __must_check __wmi_driver_register(struct wmi_driver *driver, 1414 struct module *owner) 1415 { 1416 driver->driver.owner = owner; 1417 driver->driver.bus = &wmi_bus_type; 1418 1419 return driver_register(&driver->driver); 1420 } 1421 EXPORT_SYMBOL(__wmi_driver_register); 1422 1423 void wmi_driver_unregister(struct wmi_driver *driver) 1424 { 1425 driver_unregister(&driver->driver); 1426 } 1427 EXPORT_SYMBOL(wmi_driver_unregister); 1428 1429 static int __init acpi_wmi_init(void) 1430 { 1431 int error; 1432 1433 if (acpi_disabled) 1434 return -ENODEV; 1435 1436 error = class_register(&wmi_bus_class); 1437 if (error) 1438 return error; 1439 1440 error = bus_register(&wmi_bus_type); 1441 if (error) 1442 goto err_unreg_class; 1443 1444 error = platform_driver_register(&acpi_wmi_driver); 1445 if (error) { 1446 pr_err("Error loading mapper\n"); 1447 goto err_unreg_bus; 1448 } 1449 1450 return 0; 1451 1452 err_unreg_bus: 1453 bus_unregister(&wmi_bus_type); 1454 1455 err_unreg_class: 1456 class_unregister(&wmi_bus_class); 1457 1458 return error; 1459 } 1460 1461 static void __exit acpi_wmi_exit(void) 1462 { 1463 platform_driver_unregister(&acpi_wmi_driver); 1464 bus_unregister(&wmi_bus_type); 1465 class_unregister(&wmi_bus_class); 1466 } 1467 1468 subsys_initcall_sync(acpi_wmi_init); 1469 module_exit(acpi_wmi_exit); 1470