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