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 * WMI bus infrastructure by Andrew Lutomirski and Darren Hart: 12 * Copyright (C) 2015 Andrew Lutomirski 13 * Copyright (C) 2017 VMware, Inc. All Rights Reserved. 14 * 15 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 16 * 17 * This program is free software; you can redistribute it and/or modify 18 * it under the terms of the GNU General Public License as published by 19 * the Free Software Foundation; either version 2 of the License, or (at 20 * your option) any later version. 21 * 22 * This program is distributed in the hope that it will be useful, but 23 * WITHOUT ANY WARRANTY; without even the implied warranty of 24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 25 * General Public License for more details. 26 * 27 * You should have received a copy of the GNU General Public License along 28 * with this program; if not, write to the Free Software Foundation, Inc., 29 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. 30 * 31 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 32 */ 33 34 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 35 36 #include <linux/acpi.h> 37 #include <linux/device.h> 38 #include <linux/init.h> 39 #include <linux/kernel.h> 40 #include <linux/list.h> 41 #include <linux/miscdevice.h> 42 #include <linux/module.h> 43 #include <linux/platform_device.h> 44 #include <linux/slab.h> 45 #include <linux/types.h> 46 #include <linux/uaccess.h> 47 #include <linux/uuid.h> 48 #include <linux/wmi.h> 49 #include <uapi/linux/wmi.h> 50 51 ACPI_MODULE_NAME("wmi"); 52 MODULE_AUTHOR("Carlos Corbacho"); 53 MODULE_DESCRIPTION("ACPI-WMI Mapping Driver"); 54 MODULE_LICENSE("GPL"); 55 56 static LIST_HEAD(wmi_block_list); 57 58 struct guid_block { 59 char guid[16]; 60 union { 61 char object_id[2]; 62 struct { 63 unsigned char notify_id; 64 unsigned char reserved; 65 }; 66 }; 67 u8 instance_count; 68 u8 flags; 69 }; 70 71 struct wmi_block { 72 struct wmi_device dev; 73 struct list_head list; 74 struct guid_block gblock; 75 struct miscdevice char_dev; 76 struct mutex char_mutex; 77 struct acpi_device *acpi_device; 78 wmi_notify_handler handler; 79 void *handler_data; 80 u64 req_buf_size; 81 82 bool read_takes_no_args; 83 }; 84 85 86 /* 87 * If the GUID data block is marked as expensive, we must enable and 88 * explicitily disable data collection. 89 */ 90 #define ACPI_WMI_EXPENSIVE 0x1 91 #define ACPI_WMI_METHOD 0x2 /* GUID is a method */ 92 #define ACPI_WMI_STRING 0x4 /* GUID takes & returns a string */ 93 #define ACPI_WMI_EVENT 0x8 /* GUID is an event */ 94 95 static bool debug_event; 96 module_param(debug_event, bool, 0444); 97 MODULE_PARM_DESC(debug_event, 98 "Log WMI Events [0/1]"); 99 100 static bool debug_dump_wdg; 101 module_param(debug_dump_wdg, bool, 0444); 102 MODULE_PARM_DESC(debug_dump_wdg, 103 "Dump available WMI interfaces [0/1]"); 104 105 static int acpi_wmi_remove(struct platform_device *device); 106 static int acpi_wmi_probe(struct platform_device *device); 107 108 static const struct acpi_device_id wmi_device_ids[] = { 109 {"PNP0C14", 0}, 110 {"pnp0c14", 0}, 111 {"", 0}, 112 }; 113 MODULE_DEVICE_TABLE(acpi, wmi_device_ids); 114 115 static struct platform_driver acpi_wmi_driver = { 116 .driver = { 117 .name = "acpi-wmi", 118 .acpi_match_table = wmi_device_ids, 119 }, 120 .probe = acpi_wmi_probe, 121 .remove = acpi_wmi_remove, 122 }; 123 124 /* 125 * GUID parsing functions 126 */ 127 128 static bool find_guid(const char *guid_string, struct wmi_block **out) 129 { 130 uuid_le guid_input; 131 struct wmi_block *wblock; 132 struct guid_block *block; 133 struct list_head *p; 134 135 if (uuid_le_to_bin(guid_string, &guid_input)) 136 return false; 137 138 list_for_each(p, &wmi_block_list) { 139 wblock = list_entry(p, struct wmi_block, list); 140 block = &wblock->gblock; 141 142 if (memcmp(block->guid, &guid_input, 16) == 0) { 143 if (out) 144 *out = wblock; 145 return true; 146 } 147 } 148 return false; 149 } 150 151 static int get_subobj_info(acpi_handle handle, const char *pathname, 152 struct acpi_device_info **info) 153 { 154 struct acpi_device_info *dummy_info, **info_ptr; 155 acpi_handle subobj_handle; 156 acpi_status status; 157 158 status = acpi_get_handle(handle, (char *)pathname, &subobj_handle); 159 if (status == AE_NOT_FOUND) 160 return -ENOENT; 161 else if (ACPI_FAILURE(status)) 162 return -EIO; 163 164 info_ptr = info ? info : &dummy_info; 165 status = acpi_get_object_info(subobj_handle, info_ptr); 166 if (ACPI_FAILURE(status)) 167 return -EIO; 168 169 if (!info) 170 kfree(dummy_info); 171 172 return 0; 173 } 174 175 static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable) 176 { 177 struct guid_block *block = NULL; 178 char method[5]; 179 acpi_status status; 180 acpi_handle handle; 181 182 block = &wblock->gblock; 183 handle = wblock->acpi_device->handle; 184 185 snprintf(method, 5, "WE%02X", block->notify_id); 186 status = acpi_execute_simple_method(handle, method, enable); 187 188 if (status != AE_OK && status != AE_NOT_FOUND) 189 return status; 190 else 191 return AE_OK; 192 } 193 194 /* 195 * Exported WMI functions 196 */ 197 198 /** 199 * set_required_buffer_size - Sets the buffer size needed for performing IOCTL 200 * @wdev: A wmi bus device from a driver 201 * @instance: Instance index 202 * 203 * Allocates memory needed for buffer, stores the buffer size in that memory 204 */ 205 int set_required_buffer_size(struct wmi_device *wdev, u64 length) 206 { 207 struct wmi_block *wblock; 208 209 wblock = container_of(wdev, struct wmi_block, dev); 210 wblock->req_buf_size = length; 211 212 return 0; 213 } 214 EXPORT_SYMBOL_GPL(set_required_buffer_size); 215 216 /** 217 * wmi_evaluate_method - Evaluate a WMI method 218 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba 219 * @instance: Instance index 220 * @method_id: Method ID to call 221 * &in: Buffer containing input for the method call 222 * &out: Empty buffer to return the method results 223 * 224 * Call an ACPI-WMI method 225 */ 226 acpi_status wmi_evaluate_method(const char *guid_string, u8 instance, 227 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out) 228 { 229 struct wmi_block *wblock = NULL; 230 231 if (!find_guid(guid_string, &wblock)) 232 return AE_ERROR; 233 return wmidev_evaluate_method(&wblock->dev, instance, method_id, 234 in, out); 235 } 236 EXPORT_SYMBOL_GPL(wmi_evaluate_method); 237 238 /** 239 * wmidev_evaluate_method - Evaluate a WMI method 240 * @wdev: A wmi bus device from a driver 241 * @instance: Instance index 242 * @method_id: Method ID to call 243 * &in: Buffer containing input for the method call 244 * &out: Empty buffer to return the method results 245 * 246 * Call an ACPI-WMI method 247 */ 248 acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance, 249 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out) 250 { 251 struct guid_block *block = NULL; 252 struct wmi_block *wblock = NULL; 253 acpi_handle handle; 254 acpi_status status; 255 struct acpi_object_list input; 256 union acpi_object params[3]; 257 char method[5] = "WM"; 258 259 wblock = container_of(wdev, struct wmi_block, dev); 260 block = &wblock->gblock; 261 handle = wblock->acpi_device->handle; 262 263 if (!(block->flags & ACPI_WMI_METHOD)) 264 return AE_BAD_DATA; 265 266 if (block->instance_count <= instance) 267 return AE_BAD_PARAMETER; 268 269 input.count = 2; 270 input.pointer = params; 271 params[0].type = ACPI_TYPE_INTEGER; 272 params[0].integer.value = instance; 273 params[1].type = ACPI_TYPE_INTEGER; 274 params[1].integer.value = method_id; 275 276 if (in) { 277 input.count = 3; 278 279 if (block->flags & ACPI_WMI_STRING) { 280 params[2].type = ACPI_TYPE_STRING; 281 } else { 282 params[2].type = ACPI_TYPE_BUFFER; 283 } 284 params[2].buffer.length = in->length; 285 params[2].buffer.pointer = in->pointer; 286 } 287 288 strncat(method, block->object_id, 2); 289 290 status = acpi_evaluate_object(handle, method, &input, out); 291 292 return status; 293 } 294 EXPORT_SYMBOL_GPL(wmidev_evaluate_method); 295 296 static acpi_status __query_block(struct wmi_block *wblock, u8 instance, 297 struct acpi_buffer *out) 298 { 299 struct guid_block *block = NULL; 300 acpi_handle handle; 301 acpi_status status, wc_status = AE_ERROR; 302 struct acpi_object_list input; 303 union acpi_object wq_params[1]; 304 char method[5]; 305 char wc_method[5] = "WC"; 306 307 if (!out) 308 return AE_BAD_PARAMETER; 309 310 block = &wblock->gblock; 311 handle = wblock->acpi_device->handle; 312 313 if (block->instance_count <= instance) 314 return AE_BAD_PARAMETER; 315 316 /* Check GUID is a data block */ 317 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD)) 318 return AE_ERROR; 319 320 input.count = 1; 321 input.pointer = wq_params; 322 wq_params[0].type = ACPI_TYPE_INTEGER; 323 wq_params[0].integer.value = instance; 324 325 if (instance == 0 && wblock->read_takes_no_args) 326 input.count = 0; 327 328 /* 329 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to 330 * enable collection. 331 */ 332 if (block->flags & ACPI_WMI_EXPENSIVE) { 333 strncat(wc_method, block->object_id, 2); 334 335 /* 336 * Some GUIDs break the specification by declaring themselves 337 * expensive, but have no corresponding WCxx method. So we 338 * should not fail if this happens. 339 */ 340 if (acpi_has_method(handle, wc_method)) 341 wc_status = acpi_execute_simple_method(handle, 342 wc_method, 1); 343 } 344 345 strcpy(method, "WQ"); 346 strncat(method, block->object_id, 2); 347 348 status = acpi_evaluate_object(handle, method, &input, out); 349 350 /* 351 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if 352 * the WQxx method failed - we should disable collection anyway. 353 */ 354 if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) { 355 status = acpi_execute_simple_method(handle, wc_method, 0); 356 } 357 358 return status; 359 } 360 361 /** 362 * wmi_query_block - Return contents of a WMI block (deprecated) 363 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba 364 * @instance: Instance index 365 * &out: Empty buffer to return the contents of the data block to 366 * 367 * Return the contents of an ACPI-WMI data block to a buffer 368 */ 369 acpi_status wmi_query_block(const char *guid_string, u8 instance, 370 struct acpi_buffer *out) 371 { 372 struct wmi_block *wblock; 373 374 if (!guid_string) 375 return AE_BAD_PARAMETER; 376 377 if (!find_guid(guid_string, &wblock)) 378 return AE_ERROR; 379 380 return __query_block(wblock, instance, out); 381 } 382 EXPORT_SYMBOL_GPL(wmi_query_block); 383 384 union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance) 385 { 386 struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL }; 387 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev); 388 389 if (ACPI_FAILURE(__query_block(wblock, instance, &out))) 390 return NULL; 391 392 return (union acpi_object *)out.pointer; 393 } 394 EXPORT_SYMBOL_GPL(wmidev_block_query); 395 396 /** 397 * wmi_set_block - Write to a WMI block 398 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba 399 * @instance: Instance index 400 * &in: Buffer containing new values for the data block 401 * 402 * Write the contents of the input buffer to an ACPI-WMI data block 403 */ 404 acpi_status wmi_set_block(const char *guid_string, u8 instance, 405 const struct acpi_buffer *in) 406 { 407 struct guid_block *block = NULL; 408 struct wmi_block *wblock = NULL; 409 acpi_handle handle; 410 struct acpi_object_list input; 411 union acpi_object params[2]; 412 char method[5] = "WS"; 413 414 if (!guid_string || !in) 415 return AE_BAD_DATA; 416 417 if (!find_guid(guid_string, &wblock)) 418 return AE_ERROR; 419 420 block = &wblock->gblock; 421 handle = wblock->acpi_device->handle; 422 423 if (block->instance_count <= instance) 424 return AE_BAD_PARAMETER; 425 426 /* Check GUID is a data block */ 427 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD)) 428 return AE_ERROR; 429 430 input.count = 2; 431 input.pointer = params; 432 params[0].type = ACPI_TYPE_INTEGER; 433 params[0].integer.value = instance; 434 435 if (block->flags & ACPI_WMI_STRING) { 436 params[1].type = ACPI_TYPE_STRING; 437 } else { 438 params[1].type = ACPI_TYPE_BUFFER; 439 } 440 params[1].buffer.length = in->length; 441 params[1].buffer.pointer = in->pointer; 442 443 strncat(method, block->object_id, 2); 444 445 return acpi_evaluate_object(handle, method, &input, NULL); 446 } 447 EXPORT_SYMBOL_GPL(wmi_set_block); 448 449 static void wmi_dump_wdg(const struct guid_block *g) 450 { 451 pr_info("%pUL:\n", g->guid); 452 if (g->flags & ACPI_WMI_EVENT) 453 pr_info("\tnotify_id: 0x%02X\n", g->notify_id); 454 else 455 pr_info("\tobject_id: %2pE\n", g->object_id); 456 pr_info("\tinstance_count: %d\n", g->instance_count); 457 pr_info("\tflags: %#x", g->flags); 458 if (g->flags) { 459 if (g->flags & ACPI_WMI_EXPENSIVE) 460 pr_cont(" ACPI_WMI_EXPENSIVE"); 461 if (g->flags & ACPI_WMI_METHOD) 462 pr_cont(" ACPI_WMI_METHOD"); 463 if (g->flags & ACPI_WMI_STRING) 464 pr_cont(" ACPI_WMI_STRING"); 465 if (g->flags & ACPI_WMI_EVENT) 466 pr_cont(" ACPI_WMI_EVENT"); 467 } 468 pr_cont("\n"); 469 470 } 471 472 static void wmi_notify_debug(u32 value, void *context) 473 { 474 struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL }; 475 union acpi_object *obj; 476 acpi_status status; 477 478 status = wmi_get_event_data(value, &response); 479 if (status != AE_OK) { 480 pr_info("bad event status 0x%x\n", status); 481 return; 482 } 483 484 obj = (union acpi_object *)response.pointer; 485 486 if (!obj) 487 return; 488 489 pr_info("DEBUG Event "); 490 switch(obj->type) { 491 case ACPI_TYPE_BUFFER: 492 pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length); 493 break; 494 case ACPI_TYPE_STRING: 495 pr_cont("STRING_TYPE - %s\n", obj->string.pointer); 496 break; 497 case ACPI_TYPE_INTEGER: 498 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value); 499 break; 500 case ACPI_TYPE_PACKAGE: 501 pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count); 502 break; 503 default: 504 pr_cont("object type 0x%X\n", obj->type); 505 } 506 kfree(obj); 507 } 508 509 /** 510 * wmi_install_notify_handler - Register handler for WMI events 511 * @handler: Function to handle notifications 512 * @data: Data to be returned to handler when event is fired 513 * 514 * Register a handler for events sent to the ACPI-WMI mapper device. 515 */ 516 acpi_status wmi_install_notify_handler(const char *guid, 517 wmi_notify_handler handler, void *data) 518 { 519 struct wmi_block *block; 520 acpi_status status = AE_NOT_EXIST; 521 uuid_le guid_input; 522 struct list_head *p; 523 524 if (!guid || !handler) 525 return AE_BAD_PARAMETER; 526 527 if (uuid_le_to_bin(guid, &guid_input)) 528 return AE_BAD_PARAMETER; 529 530 list_for_each(p, &wmi_block_list) { 531 acpi_status wmi_status; 532 block = list_entry(p, struct wmi_block, list); 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 * 556 * Unregister handler for events sent to the ACPI-WMI mapper device. 557 */ 558 acpi_status wmi_remove_notify_handler(const char *guid) 559 { 560 struct wmi_block *block; 561 acpi_status status = AE_NOT_EXIST; 562 uuid_le guid_input; 563 struct list_head *p; 564 565 if (!guid) 566 return AE_BAD_PARAMETER; 567 568 if (uuid_le_to_bin(guid, &guid_input)) 569 return AE_BAD_PARAMETER; 570 571 list_for_each(p, &wmi_block_list) { 572 acpi_status wmi_status; 573 block = list_entry(p, struct wmi_block, list); 574 575 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) { 576 if (!block->handler || 577 block->handler == wmi_notify_debug) 578 return AE_NULL_ENTRY; 579 580 if (debug_event) { 581 block->handler = wmi_notify_debug; 582 status = AE_OK; 583 } else { 584 wmi_status = wmi_method_enable(block, 0); 585 block->handler = NULL; 586 block->handler_data = NULL; 587 if ((wmi_status != AE_OK) || 588 ((wmi_status == AE_OK) && 589 (status == AE_NOT_EXIST))) 590 status = wmi_status; 591 } 592 } 593 } 594 595 return status; 596 } 597 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler); 598 599 /** 600 * wmi_get_event_data - Get WMI data associated with an event 601 * 602 * @event: Event to find 603 * @out: Buffer to hold event data. out->pointer should be freed with kfree() 604 * 605 * Returns extra data associated with an event in WMI. 606 */ 607 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out) 608 { 609 struct acpi_object_list input; 610 union acpi_object params[1]; 611 struct guid_block *gblock; 612 struct wmi_block *wblock; 613 struct list_head *p; 614 615 input.count = 1; 616 input.pointer = params; 617 params[0].type = ACPI_TYPE_INTEGER; 618 params[0].integer.value = event; 619 620 list_for_each(p, &wmi_block_list) { 621 wblock = list_entry(p, struct wmi_block, list); 622 gblock = &wblock->gblock; 623 624 if ((gblock->flags & ACPI_WMI_EVENT) && 625 (gblock->notify_id == event)) 626 return acpi_evaluate_object(wblock->acpi_device->handle, 627 "_WED", &input, out); 628 } 629 630 return AE_NOT_FOUND; 631 } 632 EXPORT_SYMBOL_GPL(wmi_get_event_data); 633 634 /** 635 * wmi_has_guid - Check if a GUID is available 636 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba 637 * 638 * Check if a given GUID is defined by _WDG 639 */ 640 bool wmi_has_guid(const char *guid_string) 641 { 642 return find_guid(guid_string, NULL); 643 } 644 EXPORT_SYMBOL_GPL(wmi_has_guid); 645 646 static struct wmi_block *dev_to_wblock(struct device *dev) 647 { 648 return container_of(dev, struct wmi_block, dev.dev); 649 } 650 651 static struct wmi_device *dev_to_wdev(struct device *dev) 652 { 653 return container_of(dev, struct wmi_device, dev); 654 } 655 656 /* 657 * sysfs interface 658 */ 659 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, 660 char *buf) 661 { 662 struct wmi_block *wblock = dev_to_wblock(dev); 663 664 return sprintf(buf, "wmi:%pUL\n", wblock->gblock.guid); 665 } 666 static DEVICE_ATTR_RO(modalias); 667 668 static ssize_t guid_show(struct device *dev, struct device_attribute *attr, 669 char *buf) 670 { 671 struct wmi_block *wblock = dev_to_wblock(dev); 672 673 return sprintf(buf, "%pUL\n", wblock->gblock.guid); 674 } 675 static DEVICE_ATTR_RO(guid); 676 677 static ssize_t instance_count_show(struct device *dev, 678 struct device_attribute *attr, char *buf) 679 { 680 struct wmi_block *wblock = dev_to_wblock(dev); 681 682 return sprintf(buf, "%d\n", (int)wblock->gblock.instance_count); 683 } 684 static DEVICE_ATTR_RO(instance_count); 685 686 static ssize_t expensive_show(struct device *dev, 687 struct device_attribute *attr, char *buf) 688 { 689 struct wmi_block *wblock = dev_to_wblock(dev); 690 691 return sprintf(buf, "%d\n", 692 (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0); 693 } 694 static DEVICE_ATTR_RO(expensive); 695 696 static struct attribute *wmi_attrs[] = { 697 &dev_attr_modalias.attr, 698 &dev_attr_guid.attr, 699 &dev_attr_instance_count.attr, 700 &dev_attr_expensive.attr, 701 NULL, 702 }; 703 ATTRIBUTE_GROUPS(wmi); 704 705 static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr, 706 char *buf) 707 { 708 struct wmi_block *wblock = dev_to_wblock(dev); 709 710 return sprintf(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id); 711 } 712 static DEVICE_ATTR_RO(notify_id); 713 714 static struct attribute *wmi_event_attrs[] = { 715 &dev_attr_notify_id.attr, 716 NULL, 717 }; 718 ATTRIBUTE_GROUPS(wmi_event); 719 720 static ssize_t object_id_show(struct device *dev, struct device_attribute *attr, 721 char *buf) 722 { 723 struct wmi_block *wblock = dev_to_wblock(dev); 724 725 return sprintf(buf, "%c%c\n", wblock->gblock.object_id[0], 726 wblock->gblock.object_id[1]); 727 } 728 static DEVICE_ATTR_RO(object_id); 729 730 static ssize_t setable_show(struct device *dev, struct device_attribute *attr, 731 char *buf) 732 { 733 struct wmi_device *wdev = dev_to_wdev(dev); 734 735 return sprintf(buf, "%d\n", (int)wdev->setable); 736 } 737 static DEVICE_ATTR_RO(setable); 738 739 static struct attribute *wmi_data_attrs[] = { 740 &dev_attr_object_id.attr, 741 &dev_attr_setable.attr, 742 NULL, 743 }; 744 ATTRIBUTE_GROUPS(wmi_data); 745 746 static struct attribute *wmi_method_attrs[] = { 747 &dev_attr_object_id.attr, 748 NULL, 749 }; 750 ATTRIBUTE_GROUPS(wmi_method); 751 752 static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env) 753 { 754 struct wmi_block *wblock = dev_to_wblock(dev); 755 756 if (add_uevent_var(env, "MODALIAS=wmi:%pUL", wblock->gblock.guid)) 757 return -ENOMEM; 758 759 if (add_uevent_var(env, "WMI_GUID=%pUL", wblock->gblock.guid)) 760 return -ENOMEM; 761 762 return 0; 763 } 764 765 static void wmi_dev_release(struct device *dev) 766 { 767 struct wmi_block *wblock = dev_to_wblock(dev); 768 769 kfree(wblock); 770 } 771 772 static int wmi_dev_match(struct device *dev, struct device_driver *driver) 773 { 774 struct wmi_driver *wmi_driver = 775 container_of(driver, struct wmi_driver, driver); 776 struct wmi_block *wblock = dev_to_wblock(dev); 777 const struct wmi_device_id *id = wmi_driver->id_table; 778 779 while (id->guid_string) { 780 uuid_le driver_guid; 781 782 if (WARN_ON(uuid_le_to_bin(id->guid_string, &driver_guid))) 783 continue; 784 if (!memcmp(&driver_guid, wblock->gblock.guid, 16)) 785 return 1; 786 787 id++; 788 } 789 790 return 0; 791 } 792 static int wmi_char_open(struct inode *inode, struct file *filp) 793 { 794 const char *driver_name = filp->f_path.dentry->d_iname; 795 struct wmi_block *wblock = NULL; 796 struct wmi_block *next = NULL; 797 798 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) { 799 if (!wblock->dev.dev.driver) 800 continue; 801 if (strcmp(driver_name, wblock->dev.dev.driver->name) == 0) { 802 filp->private_data = wblock; 803 break; 804 } 805 } 806 807 if (!filp->private_data) 808 return -ENODEV; 809 810 return nonseekable_open(inode, filp); 811 } 812 813 static ssize_t wmi_char_read(struct file *filp, char __user *buffer, 814 size_t length, loff_t *offset) 815 { 816 struct wmi_block *wblock = filp->private_data; 817 818 return simple_read_from_buffer(buffer, length, offset, 819 &wblock->req_buf_size, 820 sizeof(wblock->req_buf_size)); 821 } 822 823 static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 824 { 825 struct wmi_ioctl_buffer __user *input = 826 (struct wmi_ioctl_buffer __user *) arg; 827 struct wmi_block *wblock = filp->private_data; 828 struct wmi_ioctl_buffer *buf = NULL; 829 struct wmi_driver *wdriver = NULL; 830 int ret; 831 832 if (_IOC_TYPE(cmd) != WMI_IOC) 833 return -ENOTTY; 834 835 /* make sure we're not calling a higher instance than exists*/ 836 if (_IOC_NR(cmd) >= wblock->gblock.instance_count) 837 return -EINVAL; 838 839 mutex_lock(&wblock->char_mutex); 840 buf = wblock->handler_data; 841 if (get_user(buf->length, &input->length)) { 842 dev_dbg(&wblock->dev.dev, "Read length from user failed\n"); 843 ret = -EFAULT; 844 goto out_ioctl; 845 } 846 /* if it's too small, abort */ 847 if (buf->length < wblock->req_buf_size) { 848 dev_err(&wblock->dev.dev, 849 "Buffer %lld too small, need at least %lld\n", 850 buf->length, wblock->req_buf_size); 851 ret = -EINVAL; 852 goto out_ioctl; 853 } 854 /* if it's too big, warn, driver will only use what is needed */ 855 if (buf->length > wblock->req_buf_size) 856 dev_warn(&wblock->dev.dev, 857 "Buffer %lld is bigger than required %lld\n", 858 buf->length, wblock->req_buf_size); 859 860 /* copy the structure from userspace */ 861 if (copy_from_user(buf, input, wblock->req_buf_size)) { 862 dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n", 863 wblock->req_buf_size); 864 ret = -EFAULT; 865 goto out_ioctl; 866 } 867 868 /* let the driver do any filtering and do the call */ 869 wdriver = container_of(wblock->dev.dev.driver, 870 struct wmi_driver, driver); 871 if (!try_module_get(wdriver->driver.owner)) { 872 ret = -EBUSY; 873 goto out_ioctl; 874 } 875 ret = wdriver->filter_callback(&wblock->dev, cmd, buf); 876 module_put(wdriver->driver.owner); 877 if (ret) 878 goto out_ioctl; 879 880 /* return the result (only up to our internal buffer size) */ 881 if (copy_to_user(input, buf, wblock->req_buf_size)) { 882 dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n", 883 wblock->req_buf_size); 884 ret = -EFAULT; 885 } 886 887 out_ioctl: 888 mutex_unlock(&wblock->char_mutex); 889 return ret; 890 } 891 892 static const struct file_operations wmi_fops = { 893 .owner = THIS_MODULE, 894 .read = wmi_char_read, 895 .open = wmi_char_open, 896 .unlocked_ioctl = wmi_ioctl, 897 .compat_ioctl = wmi_ioctl, 898 }; 899 900 static int wmi_dev_probe(struct device *dev) 901 { 902 struct wmi_block *wblock = dev_to_wblock(dev); 903 struct wmi_driver *wdriver = 904 container_of(dev->driver, struct wmi_driver, driver); 905 int ret = 0; 906 int count; 907 char *buf; 908 909 if (ACPI_FAILURE(wmi_method_enable(wblock, 1))) 910 dev_warn(dev, "failed to enable device -- probing anyway\n"); 911 912 if (wdriver->probe) { 913 ret = wdriver->probe(dev_to_wdev(dev)); 914 if (ret != 0) 915 goto probe_failure; 916 } 917 918 /* driver wants a character device made */ 919 if (wdriver->filter_callback) { 920 /* check that required buffer size declared by driver or MOF */ 921 if (!wblock->req_buf_size) { 922 dev_err(&wblock->dev.dev, 923 "Required buffer size not set\n"); 924 ret = -EINVAL; 925 goto probe_failure; 926 } 927 928 count = get_order(wblock->req_buf_size); 929 wblock->handler_data = (void *)__get_free_pages(GFP_KERNEL, 930 count); 931 if (!wblock->handler_data) { 932 ret = -ENOMEM; 933 goto probe_failure; 934 } 935 936 buf = kmalloc(strlen(wdriver->driver.name) + 4, GFP_KERNEL); 937 if (!buf) { 938 ret = -ENOMEM; 939 goto probe_string_failure; 940 } 941 sprintf(buf, "wmi/%s", wdriver->driver.name); 942 wblock->char_dev.minor = MISC_DYNAMIC_MINOR; 943 wblock->char_dev.name = buf; 944 wblock->char_dev.fops = &wmi_fops; 945 wblock->char_dev.mode = 0444; 946 ret = misc_register(&wblock->char_dev); 947 if (ret) { 948 dev_warn(dev, "failed to register char dev: %d", ret); 949 ret = -ENOMEM; 950 goto probe_misc_failure; 951 } 952 } 953 954 return 0; 955 956 probe_misc_failure: 957 kfree(buf); 958 probe_string_failure: 959 kfree(wblock->handler_data); 960 probe_failure: 961 if (ACPI_FAILURE(wmi_method_enable(wblock, 0))) 962 dev_warn(dev, "failed to disable device\n"); 963 return ret; 964 } 965 966 static int wmi_dev_remove(struct device *dev) 967 { 968 struct wmi_block *wblock = dev_to_wblock(dev); 969 struct wmi_driver *wdriver = 970 container_of(dev->driver, struct wmi_driver, driver); 971 int ret = 0; 972 973 if (wdriver->filter_callback) { 974 misc_deregister(&wblock->char_dev); 975 kfree(wblock->char_dev.name); 976 free_pages((unsigned long)wblock->handler_data, 977 get_order(wblock->req_buf_size)); 978 } 979 980 if (wdriver->remove) 981 ret = wdriver->remove(dev_to_wdev(dev)); 982 983 if (ACPI_FAILURE(wmi_method_enable(wblock, 0))) 984 dev_warn(dev, "failed to disable device\n"); 985 986 return ret; 987 } 988 989 static struct class wmi_bus_class = { 990 .name = "wmi_bus", 991 }; 992 993 static struct bus_type wmi_bus_type = { 994 .name = "wmi", 995 .dev_groups = wmi_groups, 996 .match = wmi_dev_match, 997 .uevent = wmi_dev_uevent, 998 .probe = wmi_dev_probe, 999 .remove = wmi_dev_remove, 1000 }; 1001 1002 static struct device_type wmi_type_event = { 1003 .name = "event", 1004 .groups = wmi_event_groups, 1005 .release = wmi_dev_release, 1006 }; 1007 1008 static struct device_type wmi_type_method = { 1009 .name = "method", 1010 .groups = wmi_method_groups, 1011 .release = wmi_dev_release, 1012 }; 1013 1014 static struct device_type wmi_type_data = { 1015 .name = "data", 1016 .groups = wmi_data_groups, 1017 .release = wmi_dev_release, 1018 }; 1019 1020 static int wmi_create_device(struct device *wmi_bus_dev, 1021 const struct guid_block *gblock, 1022 struct wmi_block *wblock, 1023 struct acpi_device *device) 1024 { 1025 struct acpi_device_info *info; 1026 char method[5]; 1027 int result; 1028 1029 if (gblock->flags & ACPI_WMI_EVENT) { 1030 wblock->dev.dev.type = &wmi_type_event; 1031 goto out_init; 1032 } 1033 1034 if (gblock->flags & ACPI_WMI_METHOD) { 1035 wblock->dev.dev.type = &wmi_type_method; 1036 mutex_init(&wblock->char_mutex); 1037 goto out_init; 1038 } 1039 1040 /* 1041 * Data Block Query Control Method (WQxx by convention) is 1042 * required per the WMI documentation. If it is not present, 1043 * we ignore this data block. 1044 */ 1045 strcpy(method, "WQ"); 1046 strncat(method, wblock->gblock.object_id, 2); 1047 result = get_subobj_info(device->handle, method, &info); 1048 1049 if (result) { 1050 dev_warn(wmi_bus_dev, 1051 "%s data block query control method not found", 1052 method); 1053 return result; 1054 } 1055 1056 wblock->dev.dev.type = &wmi_type_data; 1057 1058 /* 1059 * The Microsoft documentation specifically states: 1060 * 1061 * Data blocks registered with only a single instance 1062 * can ignore the parameter. 1063 * 1064 * ACPICA will get mad at us if we call the method with the wrong number 1065 * of arguments, so check what our method expects. (On some Dell 1066 * laptops, WQxx may not be a method at all.) 1067 */ 1068 if (info->type != ACPI_TYPE_METHOD || info->param_count == 0) 1069 wblock->read_takes_no_args = true; 1070 1071 kfree(info); 1072 1073 strcpy(method, "WS"); 1074 strncat(method, wblock->gblock.object_id, 2); 1075 result = get_subobj_info(device->handle, method, NULL); 1076 1077 if (result == 0) 1078 wblock->dev.setable = true; 1079 1080 out_init: 1081 wblock->dev.dev.bus = &wmi_bus_type; 1082 wblock->dev.dev.parent = wmi_bus_dev; 1083 1084 dev_set_name(&wblock->dev.dev, "%pUL", gblock->guid); 1085 1086 device_initialize(&wblock->dev.dev); 1087 1088 return 0; 1089 } 1090 1091 static void wmi_free_devices(struct acpi_device *device) 1092 { 1093 struct wmi_block *wblock, *next; 1094 1095 /* Delete devices for all the GUIDs */ 1096 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) { 1097 if (wblock->acpi_device == device) { 1098 list_del(&wblock->list); 1099 device_unregister(&wblock->dev.dev); 1100 } 1101 } 1102 } 1103 1104 static bool guid_already_parsed(struct acpi_device *device, 1105 const u8 *guid) 1106 { 1107 struct wmi_block *wblock; 1108 1109 list_for_each_entry(wblock, &wmi_block_list, list) { 1110 if (memcmp(wblock->gblock.guid, guid, 16) == 0) { 1111 /* 1112 * Because we historically didn't track the relationship 1113 * between GUIDs and ACPI nodes, we don't know whether 1114 * we need to suppress GUIDs that are unique on a 1115 * given node but duplicated across nodes. 1116 */ 1117 dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n", 1118 guid, dev_name(&wblock->acpi_device->dev)); 1119 return true; 1120 } 1121 } 1122 1123 return false; 1124 } 1125 1126 /* 1127 * Parse the _WDG method for the GUID data blocks 1128 */ 1129 static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device) 1130 { 1131 struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL}; 1132 const struct guid_block *gblock; 1133 struct wmi_block *wblock, *next; 1134 union acpi_object *obj; 1135 acpi_status status; 1136 int retval = 0; 1137 u32 i, total; 1138 1139 status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out); 1140 if (ACPI_FAILURE(status)) 1141 return -ENXIO; 1142 1143 obj = (union acpi_object *) out.pointer; 1144 if (!obj) 1145 return -ENXIO; 1146 1147 if (obj->type != ACPI_TYPE_BUFFER) { 1148 retval = -ENXIO; 1149 goto out_free_pointer; 1150 } 1151 1152 gblock = (const struct guid_block *)obj->buffer.pointer; 1153 total = obj->buffer.length / sizeof(struct guid_block); 1154 1155 for (i = 0; i < total; i++) { 1156 if (debug_dump_wdg) 1157 wmi_dump_wdg(&gblock[i]); 1158 1159 /* 1160 * Some WMI devices, like those for nVidia hooks, have a 1161 * duplicate GUID. It's not clear what we should do in this 1162 * case yet, so for now, we'll just ignore the duplicate 1163 * for device creation. 1164 */ 1165 if (guid_already_parsed(device, gblock[i].guid)) 1166 continue; 1167 1168 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL); 1169 if (!wblock) { 1170 retval = -ENOMEM; 1171 break; 1172 } 1173 1174 wblock->acpi_device = device; 1175 wblock->gblock = gblock[i]; 1176 1177 retval = wmi_create_device(wmi_bus_dev, &gblock[i], wblock, device); 1178 if (retval) { 1179 kfree(wblock); 1180 continue; 1181 } 1182 1183 list_add_tail(&wblock->list, &wmi_block_list); 1184 1185 if (debug_event) { 1186 wblock->handler = wmi_notify_debug; 1187 wmi_method_enable(wblock, 1); 1188 } 1189 } 1190 1191 /* 1192 * Now that all of the devices are created, add them to the 1193 * device tree and probe subdrivers. 1194 */ 1195 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) { 1196 if (wblock->acpi_device != device) 1197 continue; 1198 1199 retval = device_add(&wblock->dev.dev); 1200 if (retval) { 1201 dev_err(wmi_bus_dev, "failed to register %pULL\n", 1202 wblock->gblock.guid); 1203 if (debug_event) 1204 wmi_method_enable(wblock, 0); 1205 list_del(&wblock->list); 1206 put_device(&wblock->dev.dev); 1207 } 1208 } 1209 1210 out_free_pointer: 1211 kfree(out.pointer); 1212 return retval; 1213 } 1214 1215 /* 1216 * WMI can have EmbeddedControl access regions. In which case, we just want to 1217 * hand these off to the EC driver. 1218 */ 1219 static acpi_status 1220 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address, 1221 u32 bits, u64 *value, 1222 void *handler_context, void *region_context) 1223 { 1224 int result = 0, i = 0; 1225 u8 temp = 0; 1226 1227 if ((address > 0xFF) || !value) 1228 return AE_BAD_PARAMETER; 1229 1230 if (function != ACPI_READ && function != ACPI_WRITE) 1231 return AE_BAD_PARAMETER; 1232 1233 if (bits != 8) 1234 return AE_BAD_PARAMETER; 1235 1236 if (function == ACPI_READ) { 1237 result = ec_read(address, &temp); 1238 (*value) |= ((u64)temp) << i; 1239 } else { 1240 temp = 0xff & ((*value) >> i); 1241 result = ec_write(address, temp); 1242 } 1243 1244 switch (result) { 1245 case -EINVAL: 1246 return AE_BAD_PARAMETER; 1247 break; 1248 case -ENODEV: 1249 return AE_NOT_FOUND; 1250 break; 1251 case -ETIME: 1252 return AE_TIME; 1253 break; 1254 default: 1255 return AE_OK; 1256 } 1257 } 1258 1259 static void acpi_wmi_notify_handler(acpi_handle handle, u32 event, 1260 void *context) 1261 { 1262 struct guid_block *block; 1263 struct wmi_block *wblock; 1264 struct list_head *p; 1265 bool found_it = false; 1266 1267 list_for_each(p, &wmi_block_list) { 1268 wblock = list_entry(p, struct wmi_block, list); 1269 block = &wblock->gblock; 1270 1271 if (wblock->acpi_device->handle == handle && 1272 (block->flags & ACPI_WMI_EVENT) && 1273 (block->notify_id == event)) 1274 { 1275 found_it = true; 1276 break; 1277 } 1278 } 1279 1280 if (!found_it) 1281 return; 1282 1283 /* If a driver is bound, then notify the driver. */ 1284 if (wblock->dev.dev.driver) { 1285 struct wmi_driver *driver; 1286 struct acpi_object_list input; 1287 union acpi_object params[1]; 1288 struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL }; 1289 acpi_status status; 1290 1291 driver = container_of(wblock->dev.dev.driver, 1292 struct wmi_driver, driver); 1293 1294 input.count = 1; 1295 input.pointer = params; 1296 params[0].type = ACPI_TYPE_INTEGER; 1297 params[0].integer.value = event; 1298 1299 status = acpi_evaluate_object(wblock->acpi_device->handle, 1300 "_WED", &input, &evdata); 1301 if (ACPI_FAILURE(status)) { 1302 dev_warn(&wblock->dev.dev, 1303 "failed to get event data\n"); 1304 return; 1305 } 1306 1307 if (driver->notify) 1308 driver->notify(&wblock->dev, 1309 (union acpi_object *)evdata.pointer); 1310 1311 kfree(evdata.pointer); 1312 } else if (wblock->handler) { 1313 /* Legacy handler */ 1314 wblock->handler(event, wblock->handler_data); 1315 } 1316 1317 if (debug_event) { 1318 pr_info("DEBUG Event GUID: %pUL\n", 1319 wblock->gblock.guid); 1320 } 1321 1322 acpi_bus_generate_netlink_event( 1323 wblock->acpi_device->pnp.device_class, 1324 dev_name(&wblock->dev.dev), 1325 event, 0); 1326 1327 } 1328 1329 static int acpi_wmi_remove(struct platform_device *device) 1330 { 1331 struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev); 1332 1333 acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY, 1334 acpi_wmi_notify_handler); 1335 acpi_remove_address_space_handler(acpi_device->handle, 1336 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler); 1337 wmi_free_devices(acpi_device); 1338 device_destroy(&wmi_bus_class, MKDEV(0, 0)); 1339 1340 return 0; 1341 } 1342 1343 static int acpi_wmi_probe(struct platform_device *device) 1344 { 1345 struct acpi_device *acpi_device; 1346 struct device *wmi_bus_dev; 1347 acpi_status status; 1348 int error; 1349 1350 acpi_device = ACPI_COMPANION(&device->dev); 1351 if (!acpi_device) { 1352 dev_err(&device->dev, "ACPI companion is missing\n"); 1353 return -ENODEV; 1354 } 1355 1356 status = acpi_install_address_space_handler(acpi_device->handle, 1357 ACPI_ADR_SPACE_EC, 1358 &acpi_wmi_ec_space_handler, 1359 NULL, NULL); 1360 if (ACPI_FAILURE(status)) { 1361 dev_err(&device->dev, "Error installing EC region handler\n"); 1362 return -ENODEV; 1363 } 1364 1365 status = acpi_install_notify_handler(acpi_device->handle, 1366 ACPI_DEVICE_NOTIFY, 1367 acpi_wmi_notify_handler, 1368 NULL); 1369 if (ACPI_FAILURE(status)) { 1370 dev_err(&device->dev, "Error installing notify handler\n"); 1371 error = -ENODEV; 1372 goto err_remove_ec_handler; 1373 } 1374 1375 wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0), 1376 NULL, "wmi_bus-%s", dev_name(&device->dev)); 1377 if (IS_ERR(wmi_bus_dev)) { 1378 error = PTR_ERR(wmi_bus_dev); 1379 goto err_remove_notify_handler; 1380 } 1381 dev_set_drvdata(&device->dev, wmi_bus_dev); 1382 1383 error = parse_wdg(wmi_bus_dev, acpi_device); 1384 if (error) { 1385 pr_err("Failed to parse WDG method\n"); 1386 goto err_remove_busdev; 1387 } 1388 1389 return 0; 1390 1391 err_remove_busdev: 1392 device_destroy(&wmi_bus_class, MKDEV(0, 0)); 1393 1394 err_remove_notify_handler: 1395 acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY, 1396 acpi_wmi_notify_handler); 1397 1398 err_remove_ec_handler: 1399 acpi_remove_address_space_handler(acpi_device->handle, 1400 ACPI_ADR_SPACE_EC, 1401 &acpi_wmi_ec_space_handler); 1402 1403 return error; 1404 } 1405 1406 int __must_check __wmi_driver_register(struct wmi_driver *driver, 1407 struct module *owner) 1408 { 1409 driver->driver.owner = owner; 1410 driver->driver.bus = &wmi_bus_type; 1411 1412 return driver_register(&driver->driver); 1413 } 1414 EXPORT_SYMBOL(__wmi_driver_register); 1415 1416 void wmi_driver_unregister(struct wmi_driver *driver) 1417 { 1418 driver_unregister(&driver->driver); 1419 } 1420 EXPORT_SYMBOL(wmi_driver_unregister); 1421 1422 static int __init acpi_wmi_init(void) 1423 { 1424 int error; 1425 1426 if (acpi_disabled) 1427 return -ENODEV; 1428 1429 error = class_register(&wmi_bus_class); 1430 if (error) 1431 return error; 1432 1433 error = bus_register(&wmi_bus_type); 1434 if (error) 1435 goto err_unreg_class; 1436 1437 error = platform_driver_register(&acpi_wmi_driver); 1438 if (error) { 1439 pr_err("Error loading mapper\n"); 1440 goto err_unreg_bus; 1441 } 1442 1443 return 0; 1444 1445 err_unreg_bus: 1446 bus_unregister(&wmi_bus_type); 1447 1448 err_unreg_class: 1449 class_unregister(&wmi_bus_class); 1450 1451 return error; 1452 } 1453 1454 static void __exit acpi_wmi_exit(void) 1455 { 1456 platform_driver_unregister(&acpi_wmi_driver); 1457 bus_unregister(&wmi_bus_type); 1458 class_unregister(&wmi_bus_class); 1459 } 1460 1461 subsys_initcall(acpi_wmi_init); 1462 module_exit(acpi_wmi_exit); 1463