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 = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name); 937 if (!buf) { 938 ret = -ENOMEM; 939 goto probe_string_failure; 940 } 941 wblock->char_dev.minor = MISC_DYNAMIC_MINOR; 942 wblock->char_dev.name = buf; 943 wblock->char_dev.fops = &wmi_fops; 944 wblock->char_dev.mode = 0444; 945 ret = misc_register(&wblock->char_dev); 946 if (ret) { 947 dev_warn(dev, "failed to register char dev: %d", ret); 948 ret = -ENOMEM; 949 goto probe_misc_failure; 950 } 951 } 952 953 return 0; 954 955 probe_misc_failure: 956 kfree(buf); 957 probe_string_failure: 958 kfree(wblock->handler_data); 959 probe_failure: 960 if (ACPI_FAILURE(wmi_method_enable(wblock, 0))) 961 dev_warn(dev, "failed to disable device\n"); 962 return ret; 963 } 964 965 static int wmi_dev_remove(struct device *dev) 966 { 967 struct wmi_block *wblock = dev_to_wblock(dev); 968 struct wmi_driver *wdriver = 969 container_of(dev->driver, struct wmi_driver, driver); 970 int ret = 0; 971 972 if (wdriver->filter_callback) { 973 misc_deregister(&wblock->char_dev); 974 kfree(wblock->char_dev.name); 975 free_pages((unsigned long)wblock->handler_data, 976 get_order(wblock->req_buf_size)); 977 } 978 979 if (wdriver->remove) 980 ret = wdriver->remove(dev_to_wdev(dev)); 981 982 if (ACPI_FAILURE(wmi_method_enable(wblock, 0))) 983 dev_warn(dev, "failed to disable device\n"); 984 985 return ret; 986 } 987 988 static struct class wmi_bus_class = { 989 .name = "wmi_bus", 990 }; 991 992 static struct bus_type wmi_bus_type = { 993 .name = "wmi", 994 .dev_groups = wmi_groups, 995 .match = wmi_dev_match, 996 .uevent = wmi_dev_uevent, 997 .probe = wmi_dev_probe, 998 .remove = wmi_dev_remove, 999 }; 1000 1001 static struct device_type wmi_type_event = { 1002 .name = "event", 1003 .groups = wmi_event_groups, 1004 .release = wmi_dev_release, 1005 }; 1006 1007 static struct device_type wmi_type_method = { 1008 .name = "method", 1009 .groups = wmi_method_groups, 1010 .release = wmi_dev_release, 1011 }; 1012 1013 static struct device_type wmi_type_data = { 1014 .name = "data", 1015 .groups = wmi_data_groups, 1016 .release = wmi_dev_release, 1017 }; 1018 1019 static int wmi_create_device(struct device *wmi_bus_dev, 1020 const struct guid_block *gblock, 1021 struct wmi_block *wblock, 1022 struct acpi_device *device) 1023 { 1024 struct acpi_device_info *info; 1025 char method[5]; 1026 int result; 1027 1028 if (gblock->flags & ACPI_WMI_EVENT) { 1029 wblock->dev.dev.type = &wmi_type_event; 1030 goto out_init; 1031 } 1032 1033 if (gblock->flags & ACPI_WMI_METHOD) { 1034 wblock->dev.dev.type = &wmi_type_method; 1035 mutex_init(&wblock->char_mutex); 1036 goto out_init; 1037 } 1038 1039 /* 1040 * Data Block Query Control Method (WQxx by convention) is 1041 * required per the WMI documentation. If it is not present, 1042 * we ignore this data block. 1043 */ 1044 strcpy(method, "WQ"); 1045 strncat(method, wblock->gblock.object_id, 2); 1046 result = get_subobj_info(device->handle, method, &info); 1047 1048 if (result) { 1049 dev_warn(wmi_bus_dev, 1050 "%s data block query control method not found", 1051 method); 1052 return result; 1053 } 1054 1055 wblock->dev.dev.type = &wmi_type_data; 1056 1057 /* 1058 * The Microsoft documentation specifically states: 1059 * 1060 * Data blocks registered with only a single instance 1061 * can ignore the parameter. 1062 * 1063 * ACPICA will get mad at us if we call the method with the wrong number 1064 * of arguments, so check what our method expects. (On some Dell 1065 * laptops, WQxx may not be a method at all.) 1066 */ 1067 if (info->type != ACPI_TYPE_METHOD || info->param_count == 0) 1068 wblock->read_takes_no_args = true; 1069 1070 kfree(info); 1071 1072 strcpy(method, "WS"); 1073 strncat(method, wblock->gblock.object_id, 2); 1074 result = get_subobj_info(device->handle, method, NULL); 1075 1076 if (result == 0) 1077 wblock->dev.setable = true; 1078 1079 out_init: 1080 wblock->dev.dev.bus = &wmi_bus_type; 1081 wblock->dev.dev.parent = wmi_bus_dev; 1082 1083 dev_set_name(&wblock->dev.dev, "%pUL", gblock->guid); 1084 1085 device_initialize(&wblock->dev.dev); 1086 1087 return 0; 1088 } 1089 1090 static void wmi_free_devices(struct acpi_device *device) 1091 { 1092 struct wmi_block *wblock, *next; 1093 1094 /* Delete devices for all the GUIDs */ 1095 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) { 1096 if (wblock->acpi_device == device) { 1097 list_del(&wblock->list); 1098 device_unregister(&wblock->dev.dev); 1099 } 1100 } 1101 } 1102 1103 static bool guid_already_parsed(struct acpi_device *device, 1104 const u8 *guid) 1105 { 1106 struct wmi_block *wblock; 1107 1108 list_for_each_entry(wblock, &wmi_block_list, list) { 1109 if (memcmp(wblock->gblock.guid, guid, 16) == 0) { 1110 /* 1111 * Because we historically didn't track the relationship 1112 * between GUIDs and ACPI nodes, we don't know whether 1113 * we need to suppress GUIDs that are unique on a 1114 * given node but duplicated across nodes. 1115 */ 1116 dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n", 1117 guid, dev_name(&wblock->acpi_device->dev)); 1118 return true; 1119 } 1120 } 1121 1122 return false; 1123 } 1124 1125 /* 1126 * Parse the _WDG method for the GUID data blocks 1127 */ 1128 static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device) 1129 { 1130 struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL}; 1131 const struct guid_block *gblock; 1132 struct wmi_block *wblock, *next; 1133 union acpi_object *obj; 1134 acpi_status status; 1135 int retval = 0; 1136 u32 i, total; 1137 1138 status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out); 1139 if (ACPI_FAILURE(status)) 1140 return -ENXIO; 1141 1142 obj = (union acpi_object *) out.pointer; 1143 if (!obj) 1144 return -ENXIO; 1145 1146 if (obj->type != ACPI_TYPE_BUFFER) { 1147 retval = -ENXIO; 1148 goto out_free_pointer; 1149 } 1150 1151 gblock = (const struct guid_block *)obj->buffer.pointer; 1152 total = obj->buffer.length / sizeof(struct guid_block); 1153 1154 for (i = 0; i < total; i++) { 1155 if (debug_dump_wdg) 1156 wmi_dump_wdg(&gblock[i]); 1157 1158 /* 1159 * Some WMI devices, like those for nVidia hooks, have a 1160 * duplicate GUID. It's not clear what we should do in this 1161 * case yet, so for now, we'll just ignore the duplicate 1162 * for device creation. 1163 */ 1164 if (guid_already_parsed(device, gblock[i].guid)) 1165 continue; 1166 1167 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL); 1168 if (!wblock) { 1169 retval = -ENOMEM; 1170 break; 1171 } 1172 1173 wblock->acpi_device = device; 1174 wblock->gblock = gblock[i]; 1175 1176 retval = wmi_create_device(wmi_bus_dev, &gblock[i], wblock, device); 1177 if (retval) { 1178 kfree(wblock); 1179 continue; 1180 } 1181 1182 list_add_tail(&wblock->list, &wmi_block_list); 1183 1184 if (debug_event) { 1185 wblock->handler = wmi_notify_debug; 1186 wmi_method_enable(wblock, 1); 1187 } 1188 } 1189 1190 /* 1191 * Now that all of the devices are created, add them to the 1192 * device tree and probe subdrivers. 1193 */ 1194 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) { 1195 if (wblock->acpi_device != device) 1196 continue; 1197 1198 retval = device_add(&wblock->dev.dev); 1199 if (retval) { 1200 dev_err(wmi_bus_dev, "failed to register %pULL\n", 1201 wblock->gblock.guid); 1202 if (debug_event) 1203 wmi_method_enable(wblock, 0); 1204 list_del(&wblock->list); 1205 put_device(&wblock->dev.dev); 1206 } 1207 } 1208 1209 out_free_pointer: 1210 kfree(out.pointer); 1211 return retval; 1212 } 1213 1214 /* 1215 * WMI can have EmbeddedControl access regions. In which case, we just want to 1216 * hand these off to the EC driver. 1217 */ 1218 static acpi_status 1219 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address, 1220 u32 bits, u64 *value, 1221 void *handler_context, void *region_context) 1222 { 1223 int result = 0, i = 0; 1224 u8 temp = 0; 1225 1226 if ((address > 0xFF) || !value) 1227 return AE_BAD_PARAMETER; 1228 1229 if (function != ACPI_READ && function != ACPI_WRITE) 1230 return AE_BAD_PARAMETER; 1231 1232 if (bits != 8) 1233 return AE_BAD_PARAMETER; 1234 1235 if (function == ACPI_READ) { 1236 result = ec_read(address, &temp); 1237 (*value) |= ((u64)temp) << i; 1238 } else { 1239 temp = 0xff & ((*value) >> i); 1240 result = ec_write(address, temp); 1241 } 1242 1243 switch (result) { 1244 case -EINVAL: 1245 return AE_BAD_PARAMETER; 1246 break; 1247 case -ENODEV: 1248 return AE_NOT_FOUND; 1249 break; 1250 case -ETIME: 1251 return AE_TIME; 1252 break; 1253 default: 1254 return AE_OK; 1255 } 1256 } 1257 1258 static void acpi_wmi_notify_handler(acpi_handle handle, u32 event, 1259 void *context) 1260 { 1261 struct guid_block *block; 1262 struct wmi_block *wblock; 1263 struct list_head *p; 1264 bool found_it = false; 1265 1266 list_for_each(p, &wmi_block_list) { 1267 wblock = list_entry(p, struct wmi_block, list); 1268 block = &wblock->gblock; 1269 1270 if (wblock->acpi_device->handle == handle && 1271 (block->flags & ACPI_WMI_EVENT) && 1272 (block->notify_id == event)) 1273 { 1274 found_it = true; 1275 break; 1276 } 1277 } 1278 1279 if (!found_it) 1280 return; 1281 1282 /* If a driver is bound, then notify the driver. */ 1283 if (wblock->dev.dev.driver) { 1284 struct wmi_driver *driver; 1285 struct acpi_object_list input; 1286 union acpi_object params[1]; 1287 struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL }; 1288 acpi_status status; 1289 1290 driver = container_of(wblock->dev.dev.driver, 1291 struct wmi_driver, driver); 1292 1293 input.count = 1; 1294 input.pointer = params; 1295 params[0].type = ACPI_TYPE_INTEGER; 1296 params[0].integer.value = event; 1297 1298 status = acpi_evaluate_object(wblock->acpi_device->handle, 1299 "_WED", &input, &evdata); 1300 if (ACPI_FAILURE(status)) { 1301 dev_warn(&wblock->dev.dev, 1302 "failed to get event data\n"); 1303 return; 1304 } 1305 1306 if (driver->notify) 1307 driver->notify(&wblock->dev, 1308 (union acpi_object *)evdata.pointer); 1309 1310 kfree(evdata.pointer); 1311 } else if (wblock->handler) { 1312 /* Legacy handler */ 1313 wblock->handler(event, wblock->handler_data); 1314 } 1315 1316 if (debug_event) { 1317 pr_info("DEBUG Event GUID: %pUL\n", 1318 wblock->gblock.guid); 1319 } 1320 1321 acpi_bus_generate_netlink_event( 1322 wblock->acpi_device->pnp.device_class, 1323 dev_name(&wblock->dev.dev), 1324 event, 0); 1325 1326 } 1327 1328 static int acpi_wmi_remove(struct platform_device *device) 1329 { 1330 struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev); 1331 1332 acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY, 1333 acpi_wmi_notify_handler); 1334 acpi_remove_address_space_handler(acpi_device->handle, 1335 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler); 1336 wmi_free_devices(acpi_device); 1337 device_destroy(&wmi_bus_class, MKDEV(0, 0)); 1338 1339 return 0; 1340 } 1341 1342 static int acpi_wmi_probe(struct platform_device *device) 1343 { 1344 struct acpi_device *acpi_device; 1345 struct device *wmi_bus_dev; 1346 acpi_status status; 1347 int error; 1348 1349 acpi_device = ACPI_COMPANION(&device->dev); 1350 if (!acpi_device) { 1351 dev_err(&device->dev, "ACPI companion is missing\n"); 1352 return -ENODEV; 1353 } 1354 1355 status = acpi_install_address_space_handler(acpi_device->handle, 1356 ACPI_ADR_SPACE_EC, 1357 &acpi_wmi_ec_space_handler, 1358 NULL, NULL); 1359 if (ACPI_FAILURE(status)) { 1360 dev_err(&device->dev, "Error installing EC region handler\n"); 1361 return -ENODEV; 1362 } 1363 1364 status = acpi_install_notify_handler(acpi_device->handle, 1365 ACPI_DEVICE_NOTIFY, 1366 acpi_wmi_notify_handler, 1367 NULL); 1368 if (ACPI_FAILURE(status)) { 1369 dev_err(&device->dev, "Error installing notify handler\n"); 1370 error = -ENODEV; 1371 goto err_remove_ec_handler; 1372 } 1373 1374 wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0), 1375 NULL, "wmi_bus-%s", dev_name(&device->dev)); 1376 if (IS_ERR(wmi_bus_dev)) { 1377 error = PTR_ERR(wmi_bus_dev); 1378 goto err_remove_notify_handler; 1379 } 1380 dev_set_drvdata(&device->dev, wmi_bus_dev); 1381 1382 error = parse_wdg(wmi_bus_dev, acpi_device); 1383 if (error) { 1384 pr_err("Failed to parse WDG method\n"); 1385 goto err_remove_busdev; 1386 } 1387 1388 return 0; 1389 1390 err_remove_busdev: 1391 device_destroy(&wmi_bus_class, MKDEV(0, 0)); 1392 1393 err_remove_notify_handler: 1394 acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY, 1395 acpi_wmi_notify_handler); 1396 1397 err_remove_ec_handler: 1398 acpi_remove_address_space_handler(acpi_device->handle, 1399 ACPI_ADR_SPACE_EC, 1400 &acpi_wmi_ec_space_handler); 1401 1402 return error; 1403 } 1404 1405 int __must_check __wmi_driver_register(struct wmi_driver *driver, 1406 struct module *owner) 1407 { 1408 driver->driver.owner = owner; 1409 driver->driver.bus = &wmi_bus_type; 1410 1411 return driver_register(&driver->driver); 1412 } 1413 EXPORT_SYMBOL(__wmi_driver_register); 1414 1415 void wmi_driver_unregister(struct wmi_driver *driver) 1416 { 1417 driver_unregister(&driver->driver); 1418 } 1419 EXPORT_SYMBOL(wmi_driver_unregister); 1420 1421 static int __init acpi_wmi_init(void) 1422 { 1423 int error; 1424 1425 if (acpi_disabled) 1426 return -ENODEV; 1427 1428 error = class_register(&wmi_bus_class); 1429 if (error) 1430 return error; 1431 1432 error = bus_register(&wmi_bus_type); 1433 if (error) 1434 goto err_unreg_class; 1435 1436 error = platform_driver_register(&acpi_wmi_driver); 1437 if (error) { 1438 pr_err("Error loading mapper\n"); 1439 goto err_unreg_bus; 1440 } 1441 1442 return 0; 1443 1444 err_unreg_bus: 1445 bus_unregister(&wmi_bus_type); 1446 1447 err_unreg_class: 1448 class_unregister(&wmi_bus_class); 1449 1450 return error; 1451 } 1452 1453 static void __exit acpi_wmi_exit(void) 1454 { 1455 platform_driver_unregister(&acpi_wmi_driver); 1456 bus_unregister(&wmi_bus_type); 1457 class_unregister(&wmi_bus_class); 1458 } 1459 1460 subsys_initcall_sync(acpi_wmi_init); 1461 module_exit(acpi_wmi_exit); 1462