1 /* 2 * scan.c - support for transforming the ACPI namespace into individual objects 3 */ 4 5 #include <linux/module.h> 6 #include <linux/init.h> 7 #include <linux/kernel.h> 8 #include <linux/acpi.h> 9 10 #include <acpi/acpi_drivers.h> 11 #include <acpi/acinterp.h> /* for acpi_ex_eisa_id_to_string() */ 12 13 #define _COMPONENT ACPI_BUS_COMPONENT 14 ACPI_MODULE_NAME("scan") 15 #define STRUCT_TO_INT(s) (*((int*)&s)) 16 extern struct acpi_device *acpi_root; 17 18 #define ACPI_BUS_CLASS "system_bus" 19 #define ACPI_BUS_HID "ACPI_BUS" 20 #define ACPI_BUS_DRIVER_NAME "ACPI Bus Driver" 21 #define ACPI_BUS_DEVICE_NAME "System Bus" 22 23 static LIST_HEAD(acpi_device_list); 24 DEFINE_SPINLOCK(acpi_device_lock); 25 LIST_HEAD(acpi_wakeup_device_list); 26 27 28 static void acpi_device_release(struct kobject *kobj) 29 { 30 struct acpi_device *dev = container_of(kobj, struct acpi_device, kobj); 31 kfree(dev->pnp.cid_list); 32 kfree(dev); 33 } 34 35 struct acpi_device_attribute { 36 struct attribute attr; 37 ssize_t(*show) (struct acpi_device *, char *); 38 ssize_t(*store) (struct acpi_device *, const char *, size_t); 39 }; 40 41 typedef void acpi_device_sysfs_files(struct kobject *, 42 const struct attribute *); 43 44 static void setup_sys_fs_device_files(struct acpi_device *dev, 45 acpi_device_sysfs_files * func); 46 47 #define create_sysfs_device_files(dev) \ 48 setup_sys_fs_device_files(dev, (acpi_device_sysfs_files *)&sysfs_create_file) 49 #define remove_sysfs_device_files(dev) \ 50 setup_sys_fs_device_files(dev, (acpi_device_sysfs_files *)&sysfs_remove_file) 51 52 #define to_acpi_device(n) container_of(n, struct acpi_device, kobj) 53 #define to_handle_attr(n) container_of(n, struct acpi_device_attribute, attr); 54 55 static ssize_t acpi_device_attr_show(struct kobject *kobj, 56 struct attribute *attr, char *buf) 57 { 58 struct acpi_device *device = to_acpi_device(kobj); 59 struct acpi_device_attribute *attribute = to_handle_attr(attr); 60 return attribute->show ? attribute->show(device, buf) : -EIO; 61 } 62 static ssize_t acpi_device_attr_store(struct kobject *kobj, 63 struct attribute *attr, const char *buf, 64 size_t len) 65 { 66 struct acpi_device *device = to_acpi_device(kobj); 67 struct acpi_device_attribute *attribute = to_handle_attr(attr); 68 return attribute->store ? attribute->store(device, buf, len) : -EIO; 69 } 70 71 static struct sysfs_ops acpi_device_sysfs_ops = { 72 .show = acpi_device_attr_show, 73 .store = acpi_device_attr_store, 74 }; 75 76 static struct kobj_type ktype_acpi_ns = { 77 .sysfs_ops = &acpi_device_sysfs_ops, 78 .release = acpi_device_release, 79 }; 80 81 static int namespace_uevent(struct kset *kset, struct kobject *kobj, 82 char **envp, int num_envp, char *buffer, 83 int buffer_size) 84 { 85 struct acpi_device *dev = to_acpi_device(kobj); 86 int i = 0; 87 int len = 0; 88 89 if (!dev->driver) 90 return 0; 91 92 if (add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len, 93 "PHYSDEVDRIVER=%s", dev->driver->name)) 94 return -ENOMEM; 95 96 envp[i] = NULL; 97 98 return 0; 99 } 100 101 static struct kset_uevent_ops namespace_uevent_ops = { 102 .uevent = &namespace_uevent, 103 }; 104 105 static struct kset acpi_namespace_kset = { 106 .kobj = { 107 .name = "namespace", 108 }, 109 .subsys = &acpi_subsys, 110 .ktype = &ktype_acpi_ns, 111 .uevent_ops = &namespace_uevent_ops, 112 }; 113 114 static void acpi_device_register(struct acpi_device *device, 115 struct acpi_device *parent) 116 { 117 int err; 118 119 /* 120 * Linkage 121 * ------- 122 * Link this device to its parent and siblings. 123 */ 124 INIT_LIST_HEAD(&device->children); 125 INIT_LIST_HEAD(&device->node); 126 INIT_LIST_HEAD(&device->g_list); 127 INIT_LIST_HEAD(&device->wakeup_list); 128 129 spin_lock(&acpi_device_lock); 130 if (device->parent) { 131 list_add_tail(&device->node, &device->parent->children); 132 list_add_tail(&device->g_list, &device->parent->g_list); 133 } else 134 list_add_tail(&device->g_list, &acpi_device_list); 135 if (device->wakeup.flags.valid) 136 list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list); 137 spin_unlock(&acpi_device_lock); 138 139 strlcpy(device->kobj.name, device->pnp.bus_id, KOBJ_NAME_LEN); 140 if (parent) 141 device->kobj.parent = &parent->kobj; 142 device->kobj.ktype = &ktype_acpi_ns; 143 device->kobj.kset = &acpi_namespace_kset; 144 err = kobject_register(&device->kobj); 145 if (err < 0) 146 printk(KERN_WARNING "%s: kobject_register error: %d\n", 147 __FUNCTION__, err); 148 create_sysfs_device_files(device); 149 } 150 151 static void acpi_device_unregister(struct acpi_device *device, int type) 152 { 153 spin_lock(&acpi_device_lock); 154 if (device->parent) { 155 list_del(&device->node); 156 list_del(&device->g_list); 157 } else 158 list_del(&device->g_list); 159 160 list_del(&device->wakeup_list); 161 162 spin_unlock(&acpi_device_lock); 163 164 acpi_detach_data(device->handle, acpi_bus_data_handler); 165 remove_sysfs_device_files(device); 166 kobject_unregister(&device->kobj); 167 } 168 169 void acpi_bus_data_handler(acpi_handle handle, u32 function, void *context) 170 { 171 172 /* TBD */ 173 174 return; 175 } 176 177 static int acpi_bus_get_power_flags(struct acpi_device *device) 178 { 179 acpi_status status = 0; 180 acpi_handle handle = NULL; 181 u32 i = 0; 182 183 184 /* 185 * Power Management Flags 186 */ 187 status = acpi_get_handle(device->handle, "_PSC", &handle); 188 if (ACPI_SUCCESS(status)) 189 device->power.flags.explicit_get = 1; 190 status = acpi_get_handle(device->handle, "_IRC", &handle); 191 if (ACPI_SUCCESS(status)) 192 device->power.flags.inrush_current = 1; 193 194 /* 195 * Enumerate supported power management states 196 */ 197 for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3; i++) { 198 struct acpi_device_power_state *ps = &device->power.states[i]; 199 char object_name[5] = { '_', 'P', 'R', '0' + i, '\0' }; 200 201 /* Evaluate "_PRx" to se if power resources are referenced */ 202 acpi_evaluate_reference(device->handle, object_name, NULL, 203 &ps->resources); 204 if (ps->resources.count) { 205 device->power.flags.power_resources = 1; 206 ps->flags.valid = 1; 207 } 208 209 /* Evaluate "_PSx" to see if we can do explicit sets */ 210 object_name[2] = 'S'; 211 status = acpi_get_handle(device->handle, object_name, &handle); 212 if (ACPI_SUCCESS(status)) { 213 ps->flags.explicit_set = 1; 214 ps->flags.valid = 1; 215 } 216 217 /* State is valid if we have some power control */ 218 if (ps->resources.count || ps->flags.explicit_set) 219 ps->flags.valid = 1; 220 221 ps->power = -1; /* Unknown - driver assigned */ 222 ps->latency = -1; /* Unknown - driver assigned */ 223 } 224 225 /* Set defaults for D0 and D3 states (always valid) */ 226 device->power.states[ACPI_STATE_D0].flags.valid = 1; 227 device->power.states[ACPI_STATE_D0].power = 100; 228 device->power.states[ACPI_STATE_D3].flags.valid = 1; 229 device->power.states[ACPI_STATE_D3].power = 0; 230 231 /* TBD: System wake support and resource requirements. */ 232 233 device->power.state = ACPI_STATE_UNKNOWN; 234 235 return 0; 236 } 237 238 int acpi_match_ids(struct acpi_device *device, char *ids) 239 { 240 if (device->flags.hardware_id) 241 if (strstr(ids, device->pnp.hardware_id)) 242 return 0; 243 244 if (device->flags.compatible_ids) { 245 struct acpi_compatible_id_list *cid_list = device->pnp.cid_list; 246 int i; 247 248 /* compare multiple _CID entries against driver ids */ 249 for (i = 0; i < cid_list->count; i++) { 250 if (strstr(ids, cid_list->id[i].value)) 251 return 0; 252 } 253 } 254 return -ENOENT; 255 } 256 257 static acpi_status 258 acpi_bus_extract_wakeup_device_power_package(struct acpi_device *device, 259 union acpi_object *package) 260 { 261 int i = 0; 262 union acpi_object *element = NULL; 263 264 if (!device || !package || (package->package.count < 2)) 265 return AE_BAD_PARAMETER; 266 267 element = &(package->package.elements[0]); 268 if (!element) 269 return AE_BAD_PARAMETER; 270 if (element->type == ACPI_TYPE_PACKAGE) { 271 if ((element->package.count < 2) || 272 (element->package.elements[0].type != 273 ACPI_TYPE_LOCAL_REFERENCE) 274 || (element->package.elements[1].type != ACPI_TYPE_INTEGER)) 275 return AE_BAD_DATA; 276 device->wakeup.gpe_device = 277 element->package.elements[0].reference.handle; 278 device->wakeup.gpe_number = 279 (u32) element->package.elements[1].integer.value; 280 } else if (element->type == ACPI_TYPE_INTEGER) { 281 device->wakeup.gpe_number = element->integer.value; 282 } else 283 return AE_BAD_DATA; 284 285 element = &(package->package.elements[1]); 286 if (element->type != ACPI_TYPE_INTEGER) { 287 return AE_BAD_DATA; 288 } 289 device->wakeup.sleep_state = element->integer.value; 290 291 if ((package->package.count - 2) > ACPI_MAX_HANDLES) { 292 return AE_NO_MEMORY; 293 } 294 device->wakeup.resources.count = package->package.count - 2; 295 for (i = 0; i < device->wakeup.resources.count; i++) { 296 element = &(package->package.elements[i + 2]); 297 if (element->type != ACPI_TYPE_ANY) { 298 return AE_BAD_DATA; 299 } 300 301 device->wakeup.resources.handles[i] = element->reference.handle; 302 } 303 304 return AE_OK; 305 } 306 307 static int acpi_bus_get_wakeup_device_flags(struct acpi_device *device) 308 { 309 acpi_status status = 0; 310 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 311 union acpi_object *package = NULL; 312 313 314 /* _PRW */ 315 status = acpi_evaluate_object(device->handle, "_PRW", NULL, &buffer); 316 if (ACPI_FAILURE(status)) { 317 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW")); 318 goto end; 319 } 320 321 package = (union acpi_object *)buffer.pointer; 322 status = acpi_bus_extract_wakeup_device_power_package(device, package); 323 if (ACPI_FAILURE(status)) { 324 ACPI_EXCEPTION((AE_INFO, status, "Extracting _PRW package")); 325 goto end; 326 } 327 328 kfree(buffer.pointer); 329 330 device->wakeup.flags.valid = 1; 331 /* Power button, Lid switch always enable wakeup */ 332 if (!acpi_match_ids(device, "PNP0C0D,PNP0C0C,PNP0C0E")) 333 device->wakeup.flags.run_wake = 1; 334 335 end: 336 if (ACPI_FAILURE(status)) 337 device->flags.wake_capable = 0; 338 return 0; 339 } 340 341 /* -------------------------------------------------------------------------- 342 ACPI sysfs device file support 343 -------------------------------------------------------------------------- */ 344 static ssize_t acpi_eject_store(struct acpi_device *device, 345 const char *buf, size_t count); 346 347 #define ACPI_DEVICE_ATTR(_name,_mode,_show,_store) \ 348 static struct acpi_device_attribute acpi_device_attr_##_name = \ 349 __ATTR(_name, _mode, _show, _store) 350 351 ACPI_DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store); 352 353 /** 354 * setup_sys_fs_device_files - sets up the device files under device namespace 355 * @dev: acpi_device object 356 * @func: function pointer to create or destroy the device file 357 */ 358 static void 359 setup_sys_fs_device_files(struct acpi_device *dev, 360 acpi_device_sysfs_files * func) 361 { 362 acpi_status status; 363 acpi_handle temp = NULL; 364 365 /* 366 * If device has _EJ0, 'eject' file is created that is used to trigger 367 * hot-removal function from userland. 368 */ 369 status = acpi_get_handle(dev->handle, "_EJ0", &temp); 370 if (ACPI_SUCCESS(status)) 371 (*(func)) (&dev->kobj, &acpi_device_attr_eject.attr); 372 } 373 374 static int acpi_eject_operation(acpi_handle handle, int lockable) 375 { 376 struct acpi_object_list arg_list; 377 union acpi_object arg; 378 acpi_status status = AE_OK; 379 380 /* 381 * TBD: evaluate _PS3? 382 */ 383 384 if (lockable) { 385 arg_list.count = 1; 386 arg_list.pointer = &arg; 387 arg.type = ACPI_TYPE_INTEGER; 388 arg.integer.value = 0; 389 acpi_evaluate_object(handle, "_LCK", &arg_list, NULL); 390 } 391 392 arg_list.count = 1; 393 arg_list.pointer = &arg; 394 arg.type = ACPI_TYPE_INTEGER; 395 arg.integer.value = 1; 396 397 /* 398 * TBD: _EJD support. 399 */ 400 401 status = acpi_evaluate_object(handle, "_EJ0", &arg_list, NULL); 402 if (ACPI_FAILURE(status)) { 403 return (-ENODEV); 404 } 405 406 return (0); 407 } 408 409 static ssize_t 410 acpi_eject_store(struct acpi_device *device, const char *buf, size_t count) 411 { 412 int result; 413 int ret = count; 414 int islockable; 415 acpi_status status; 416 acpi_handle handle; 417 acpi_object_type type = 0; 418 419 if ((!count) || (buf[0] != '1')) { 420 return -EINVAL; 421 } 422 #ifndef FORCE_EJECT 423 if (device->driver == NULL) { 424 ret = -ENODEV; 425 goto err; 426 } 427 #endif 428 status = acpi_get_type(device->handle, &type); 429 if (ACPI_FAILURE(status) || (!device->flags.ejectable)) { 430 ret = -ENODEV; 431 goto err; 432 } 433 434 islockable = device->flags.lockable; 435 handle = device->handle; 436 437 result = acpi_bus_trim(device, 1); 438 439 if (!result) 440 result = acpi_eject_operation(handle, islockable); 441 442 if (result) { 443 ret = -EBUSY; 444 } 445 err: 446 return ret; 447 } 448 449 /* -------------------------------------------------------------------------- 450 Performance Management 451 -------------------------------------------------------------------------- */ 452 453 static int acpi_bus_get_perf_flags(struct acpi_device *device) 454 { 455 device->performance.state = ACPI_STATE_UNKNOWN; 456 return 0; 457 } 458 459 /* -------------------------------------------------------------------------- 460 Driver Management 461 -------------------------------------------------------------------------- */ 462 463 static LIST_HEAD(acpi_bus_drivers); 464 465 /** 466 * acpi_bus_match - match device IDs to driver's supported IDs 467 * @device: the device that we are trying to match to a driver 468 * @driver: driver whose device id table is being checked 469 * 470 * Checks the device's hardware (_HID) or compatible (_CID) ids to see if it 471 * matches the specified driver's criteria. 472 */ 473 static int 474 acpi_bus_match(struct acpi_device *device, struct acpi_driver *driver) 475 { 476 if (driver && driver->ops.match) 477 return driver->ops.match(device, driver); 478 return acpi_match_ids(device, driver->ids); 479 } 480 481 /** 482 * acpi_bus_driver_init - add a device to a driver 483 * @device: the device to add and initialize 484 * @driver: driver for the device 485 * 486 * Used to initialize a device via its device driver. Called whenever a 487 * driver is bound to a device. Invokes the driver's add() and start() ops. 488 */ 489 static int 490 acpi_bus_driver_init(struct acpi_device *device, struct acpi_driver *driver) 491 { 492 int result = 0; 493 494 495 if (!device || !driver) 496 return -EINVAL; 497 498 if (!driver->ops.add) 499 return -ENOSYS; 500 501 result = driver->ops.add(device); 502 if (result) { 503 device->driver = NULL; 504 acpi_driver_data(device) = NULL; 505 return result; 506 } 507 508 device->driver = driver; 509 510 /* 511 * TBD - Configuration Management: Assign resources to device based 512 * upon possible configuration and currently allocated resources. 513 */ 514 515 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 516 "Driver successfully bound to device\n")); 517 return 0; 518 } 519 520 static int acpi_start_single_object(struct acpi_device *device) 521 { 522 int result = 0; 523 struct acpi_driver *driver; 524 525 526 if (!(driver = device->driver)) 527 return 0; 528 529 if (driver->ops.start) { 530 result = driver->ops.start(device); 531 if (result && driver->ops.remove) 532 driver->ops.remove(device, ACPI_BUS_REMOVAL_NORMAL); 533 } 534 535 return result; 536 } 537 538 static void acpi_driver_attach(struct acpi_driver *drv) 539 { 540 struct list_head *node, *next; 541 542 543 spin_lock(&acpi_device_lock); 544 list_for_each_safe(node, next, &acpi_device_list) { 545 struct acpi_device *dev = 546 container_of(node, struct acpi_device, g_list); 547 548 if (dev->driver || !dev->status.present) 549 continue; 550 spin_unlock(&acpi_device_lock); 551 552 if (!acpi_bus_match(dev, drv)) { 553 if (!acpi_bus_driver_init(dev, drv)) { 554 acpi_start_single_object(dev); 555 atomic_inc(&drv->references); 556 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 557 "Found driver [%s] for device [%s]\n", 558 drv->name, dev->pnp.bus_id)); 559 } 560 } 561 spin_lock(&acpi_device_lock); 562 } 563 spin_unlock(&acpi_device_lock); 564 } 565 566 static void acpi_driver_detach(struct acpi_driver *drv) 567 { 568 struct list_head *node, *next; 569 570 571 spin_lock(&acpi_device_lock); 572 list_for_each_safe(node, next, &acpi_device_list) { 573 struct acpi_device *dev = 574 container_of(node, struct acpi_device, g_list); 575 576 if (dev->driver == drv) { 577 spin_unlock(&acpi_device_lock); 578 if (drv->ops.remove) 579 drv->ops.remove(dev, ACPI_BUS_REMOVAL_NORMAL); 580 spin_lock(&acpi_device_lock); 581 dev->driver = NULL; 582 dev->driver_data = NULL; 583 atomic_dec(&drv->references); 584 } 585 } 586 spin_unlock(&acpi_device_lock); 587 } 588 589 /** 590 * acpi_bus_register_driver - register a driver with the ACPI bus 591 * @driver: driver being registered 592 * 593 * Registers a driver with the ACPI bus. Searches the namespace for all 594 * devices that match the driver's criteria and binds. Returns zero for 595 * success or a negative error status for failure. 596 */ 597 int acpi_bus_register_driver(struct acpi_driver *driver) 598 { 599 600 if (acpi_disabled) 601 return -ENODEV; 602 603 spin_lock(&acpi_device_lock); 604 list_add_tail(&driver->node, &acpi_bus_drivers); 605 spin_unlock(&acpi_device_lock); 606 acpi_driver_attach(driver); 607 608 return 0; 609 } 610 611 EXPORT_SYMBOL(acpi_bus_register_driver); 612 613 /** 614 * acpi_bus_unregister_driver - unregisters a driver with the APIC bus 615 * @driver: driver to unregister 616 * 617 * Unregisters a driver with the ACPI bus. Searches the namespace for all 618 * devices that match the driver's criteria and unbinds. 619 */ 620 void acpi_bus_unregister_driver(struct acpi_driver *driver) 621 { 622 acpi_driver_detach(driver); 623 624 if (!atomic_read(&driver->references)) { 625 spin_lock(&acpi_device_lock); 626 list_del_init(&driver->node); 627 spin_unlock(&acpi_device_lock); 628 } 629 return; 630 } 631 632 EXPORT_SYMBOL(acpi_bus_unregister_driver); 633 634 /** 635 * acpi_bus_find_driver - check if there is a driver installed for the device 636 * @device: device that we are trying to find a supporting driver for 637 * 638 * Parses the list of registered drivers looking for a driver applicable for 639 * the specified device. 640 */ 641 static int acpi_bus_find_driver(struct acpi_device *device) 642 { 643 int result = 0; 644 struct list_head *node, *next; 645 646 647 spin_lock(&acpi_device_lock); 648 list_for_each_safe(node, next, &acpi_bus_drivers) { 649 struct acpi_driver *driver = 650 container_of(node, struct acpi_driver, node); 651 652 atomic_inc(&driver->references); 653 spin_unlock(&acpi_device_lock); 654 if (!acpi_bus_match(device, driver)) { 655 result = acpi_bus_driver_init(device, driver); 656 if (!result) 657 goto Done; 658 } 659 atomic_dec(&driver->references); 660 spin_lock(&acpi_device_lock); 661 } 662 spin_unlock(&acpi_device_lock); 663 664 Done: 665 return result; 666 } 667 668 /* -------------------------------------------------------------------------- 669 Device Enumeration 670 -------------------------------------------------------------------------- */ 671 672 acpi_status 673 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd) 674 { 675 acpi_status status; 676 acpi_handle tmp; 677 struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL}; 678 union acpi_object *obj; 679 680 status = acpi_get_handle(handle, "_EJD", &tmp); 681 if (ACPI_FAILURE(status)) 682 return status; 683 684 status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer); 685 if (ACPI_SUCCESS(status)) { 686 obj = buffer.pointer; 687 status = acpi_get_handle(NULL, obj->string.pointer, ejd); 688 kfree(buffer.pointer); 689 } 690 return status; 691 } 692 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd); 693 694 695 static int acpi_bus_get_flags(struct acpi_device *device) 696 { 697 acpi_status status = AE_OK; 698 acpi_handle temp = NULL; 699 700 701 /* Presence of _STA indicates 'dynamic_status' */ 702 status = acpi_get_handle(device->handle, "_STA", &temp); 703 if (ACPI_SUCCESS(status)) 704 device->flags.dynamic_status = 1; 705 706 /* Presence of _CID indicates 'compatible_ids' */ 707 status = acpi_get_handle(device->handle, "_CID", &temp); 708 if (ACPI_SUCCESS(status)) 709 device->flags.compatible_ids = 1; 710 711 /* Presence of _RMV indicates 'removable' */ 712 status = acpi_get_handle(device->handle, "_RMV", &temp); 713 if (ACPI_SUCCESS(status)) 714 device->flags.removable = 1; 715 716 /* Presence of _EJD|_EJ0 indicates 'ejectable' */ 717 status = acpi_get_handle(device->handle, "_EJD", &temp); 718 if (ACPI_SUCCESS(status)) 719 device->flags.ejectable = 1; 720 else { 721 status = acpi_get_handle(device->handle, "_EJ0", &temp); 722 if (ACPI_SUCCESS(status)) 723 device->flags.ejectable = 1; 724 } 725 726 /* Presence of _LCK indicates 'lockable' */ 727 status = acpi_get_handle(device->handle, "_LCK", &temp); 728 if (ACPI_SUCCESS(status)) 729 device->flags.lockable = 1; 730 731 /* Presence of _PS0|_PR0 indicates 'power manageable' */ 732 status = acpi_get_handle(device->handle, "_PS0", &temp); 733 if (ACPI_FAILURE(status)) 734 status = acpi_get_handle(device->handle, "_PR0", &temp); 735 if (ACPI_SUCCESS(status)) 736 device->flags.power_manageable = 1; 737 738 /* Presence of _PRW indicates wake capable */ 739 status = acpi_get_handle(device->handle, "_PRW", &temp); 740 if (ACPI_SUCCESS(status)) 741 device->flags.wake_capable = 1; 742 743 /* TBD: Peformance management */ 744 745 return 0; 746 } 747 748 static void acpi_device_get_busid(struct acpi_device *device, 749 acpi_handle handle, int type) 750 { 751 char bus_id[5] = { '?', 0 }; 752 struct acpi_buffer buffer = { sizeof(bus_id), bus_id }; 753 int i = 0; 754 755 /* 756 * Bus ID 757 * ------ 758 * The device's Bus ID is simply the object name. 759 * TBD: Shouldn't this value be unique (within the ACPI namespace)? 760 */ 761 switch (type) { 762 case ACPI_BUS_TYPE_SYSTEM: 763 strcpy(device->pnp.bus_id, "ACPI"); 764 break; 765 case ACPI_BUS_TYPE_POWER_BUTTON: 766 strcpy(device->pnp.bus_id, "PWRF"); 767 break; 768 case ACPI_BUS_TYPE_SLEEP_BUTTON: 769 strcpy(device->pnp.bus_id, "SLPF"); 770 break; 771 default: 772 acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer); 773 /* Clean up trailing underscores (if any) */ 774 for (i = 3; i > 1; i--) { 775 if (bus_id[i] == '_') 776 bus_id[i] = '\0'; 777 else 778 break; 779 } 780 strcpy(device->pnp.bus_id, bus_id); 781 break; 782 } 783 } 784 785 static void acpi_device_set_id(struct acpi_device *device, 786 struct acpi_device *parent, acpi_handle handle, 787 int type) 788 { 789 struct acpi_device_info *info; 790 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 791 char *hid = NULL; 792 char *uid = NULL; 793 struct acpi_compatible_id_list *cid_list = NULL; 794 acpi_status status; 795 796 switch (type) { 797 case ACPI_BUS_TYPE_DEVICE: 798 status = acpi_get_object_info(handle, &buffer); 799 if (ACPI_FAILURE(status)) { 800 printk("%s: Error reading device info\n", __FUNCTION__); 801 return; 802 } 803 804 info = buffer.pointer; 805 if (info->valid & ACPI_VALID_HID) 806 hid = info->hardware_id.value; 807 if (info->valid & ACPI_VALID_UID) 808 uid = info->unique_id.value; 809 if (info->valid & ACPI_VALID_CID) 810 cid_list = &info->compatibility_id; 811 if (info->valid & ACPI_VALID_ADR) { 812 device->pnp.bus_address = info->address; 813 device->flags.bus_address = 1; 814 } 815 break; 816 case ACPI_BUS_TYPE_POWER: 817 hid = ACPI_POWER_HID; 818 break; 819 case ACPI_BUS_TYPE_PROCESSOR: 820 hid = ACPI_PROCESSOR_HID; 821 break; 822 case ACPI_BUS_TYPE_SYSTEM: 823 hid = ACPI_SYSTEM_HID; 824 break; 825 case ACPI_BUS_TYPE_THERMAL: 826 hid = ACPI_THERMAL_HID; 827 break; 828 case ACPI_BUS_TYPE_POWER_BUTTON: 829 hid = ACPI_BUTTON_HID_POWERF; 830 break; 831 case ACPI_BUS_TYPE_SLEEP_BUTTON: 832 hid = ACPI_BUTTON_HID_SLEEPF; 833 break; 834 } 835 836 /* 837 * \_SB 838 * ---- 839 * Fix for the system root bus device -- the only root-level device. 840 */ 841 if (((acpi_handle)parent == ACPI_ROOT_OBJECT) && (type == ACPI_BUS_TYPE_DEVICE)) { 842 hid = ACPI_BUS_HID; 843 strcpy(device->pnp.device_name, ACPI_BUS_DEVICE_NAME); 844 strcpy(device->pnp.device_class, ACPI_BUS_CLASS); 845 } 846 847 if (hid) { 848 strcpy(device->pnp.hardware_id, hid); 849 device->flags.hardware_id = 1; 850 } 851 if (uid) { 852 strcpy(device->pnp.unique_id, uid); 853 device->flags.unique_id = 1; 854 } 855 if (cid_list) { 856 device->pnp.cid_list = kmalloc(cid_list->size, GFP_KERNEL); 857 if (device->pnp.cid_list) 858 memcpy(device->pnp.cid_list, cid_list, cid_list->size); 859 else 860 printk(KERN_ERR "Memory allocation error\n"); 861 } 862 863 kfree(buffer.pointer); 864 } 865 866 static int acpi_device_set_context(struct acpi_device *device, int type) 867 { 868 acpi_status status = AE_OK; 869 int result = 0; 870 /* 871 * Context 872 * ------- 873 * Attach this 'struct acpi_device' to the ACPI object. This makes 874 * resolutions from handle->device very efficient. Note that we need 875 * to be careful with fixed-feature devices as they all attach to the 876 * root object. 877 */ 878 if (type != ACPI_BUS_TYPE_POWER_BUTTON && 879 type != ACPI_BUS_TYPE_SLEEP_BUTTON) { 880 status = acpi_attach_data(device->handle, 881 acpi_bus_data_handler, device); 882 883 if (ACPI_FAILURE(status)) { 884 printk("Error attaching device data\n"); 885 result = -ENODEV; 886 } 887 } 888 return result; 889 } 890 891 static void acpi_device_get_debug_info(struct acpi_device *device, 892 acpi_handle handle, int type) 893 { 894 #ifdef CONFIG_ACPI_DEBUG_OUTPUT 895 char *type_string = NULL; 896 char name[80] = { '?', '\0' }; 897 struct acpi_buffer buffer = { sizeof(name), name }; 898 899 switch (type) { 900 case ACPI_BUS_TYPE_DEVICE: 901 type_string = "Device"; 902 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer); 903 break; 904 case ACPI_BUS_TYPE_POWER: 905 type_string = "Power Resource"; 906 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer); 907 break; 908 case ACPI_BUS_TYPE_PROCESSOR: 909 type_string = "Processor"; 910 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer); 911 break; 912 case ACPI_BUS_TYPE_SYSTEM: 913 type_string = "System"; 914 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer); 915 break; 916 case ACPI_BUS_TYPE_THERMAL: 917 type_string = "Thermal Zone"; 918 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer); 919 break; 920 case ACPI_BUS_TYPE_POWER_BUTTON: 921 type_string = "Power Button"; 922 sprintf(name, "PWRB"); 923 break; 924 case ACPI_BUS_TYPE_SLEEP_BUTTON: 925 type_string = "Sleep Button"; 926 sprintf(name, "SLPB"); 927 break; 928 } 929 930 printk(KERN_DEBUG "Found %s %s [%p]\n", type_string, name, handle); 931 #endif /*CONFIG_ACPI_DEBUG_OUTPUT */ 932 } 933 934 static int acpi_bus_remove(struct acpi_device *dev, int rmdevice) 935 { 936 int result = 0; 937 struct acpi_driver *driver; 938 939 940 if (!dev) 941 return -EINVAL; 942 943 driver = dev->driver; 944 945 if ((driver) && (driver->ops.remove)) { 946 947 if (driver->ops.stop) { 948 result = driver->ops.stop(dev, ACPI_BUS_REMOVAL_EJECT); 949 if (result) 950 return result; 951 } 952 953 result = dev->driver->ops.remove(dev, ACPI_BUS_REMOVAL_EJECT); 954 if (result) { 955 return result; 956 } 957 958 atomic_dec(&dev->driver->references); 959 dev->driver = NULL; 960 acpi_driver_data(dev) = NULL; 961 } 962 963 if (!rmdevice) 964 return 0; 965 966 if (dev->flags.bus_address) { 967 if ((dev->parent) && (dev->parent->ops.unbind)) 968 dev->parent->ops.unbind(dev); 969 } 970 971 acpi_device_unregister(dev, ACPI_BUS_REMOVAL_EJECT); 972 973 return 0; 974 } 975 976 static int 977 acpi_add_single_object(struct acpi_device **child, 978 struct acpi_device *parent, acpi_handle handle, int type) 979 { 980 int result = 0; 981 struct acpi_device *device = NULL; 982 983 984 if (!child) 985 return -EINVAL; 986 987 device = kmalloc(sizeof(struct acpi_device), GFP_KERNEL); 988 if (!device) { 989 printk(KERN_ERR PREFIX "Memory allocation error\n"); 990 return -ENOMEM; 991 } 992 memset(device, 0, sizeof(struct acpi_device)); 993 994 device->handle = handle; 995 device->parent = parent; 996 997 acpi_device_get_busid(device, handle, type); 998 999 /* 1000 * Flags 1001 * ----- 1002 * Get prior to calling acpi_bus_get_status() so we know whether 1003 * or not _STA is present. Note that we only look for object 1004 * handles -- cannot evaluate objects until we know the device is 1005 * present and properly initialized. 1006 */ 1007 result = acpi_bus_get_flags(device); 1008 if (result) 1009 goto end; 1010 1011 /* 1012 * Status 1013 * ------ 1014 * See if the device is present. We always assume that non-Device 1015 * and non-Processor objects (e.g. thermal zones, power resources, 1016 * etc.) are present, functioning, etc. (at least when parent object 1017 * is present). Note that _STA has a different meaning for some 1018 * objects (e.g. power resources) so we need to be careful how we use 1019 * it. 1020 */ 1021 switch (type) { 1022 case ACPI_BUS_TYPE_PROCESSOR: 1023 case ACPI_BUS_TYPE_DEVICE: 1024 result = acpi_bus_get_status(device); 1025 if (ACPI_FAILURE(result) || !device->status.present) { 1026 result = -ENOENT; 1027 goto end; 1028 } 1029 break; 1030 default: 1031 STRUCT_TO_INT(device->status) = 0x0F; 1032 break; 1033 } 1034 1035 /* 1036 * Initialize Device 1037 * ----------------- 1038 * TBD: Synch with Core's enumeration/initialization process. 1039 */ 1040 1041 /* 1042 * Hardware ID, Unique ID, & Bus Address 1043 * ------------------------------------- 1044 */ 1045 acpi_device_set_id(device, parent, handle, type); 1046 1047 /* 1048 * Power Management 1049 * ---------------- 1050 */ 1051 if (device->flags.power_manageable) { 1052 result = acpi_bus_get_power_flags(device); 1053 if (result) 1054 goto end; 1055 } 1056 1057 /* 1058 * Wakeup device management 1059 *----------------------- 1060 */ 1061 if (device->flags.wake_capable) { 1062 result = acpi_bus_get_wakeup_device_flags(device); 1063 if (result) 1064 goto end; 1065 } 1066 1067 /* 1068 * Performance Management 1069 * ---------------------- 1070 */ 1071 if (device->flags.performance_manageable) { 1072 result = acpi_bus_get_perf_flags(device); 1073 if (result) 1074 goto end; 1075 } 1076 1077 if ((result = acpi_device_set_context(device, type))) 1078 goto end; 1079 1080 acpi_device_get_debug_info(device, handle, type); 1081 1082 acpi_device_register(device, parent); 1083 1084 /* 1085 * Bind _ADR-Based Devices 1086 * ----------------------- 1087 * If there's a a bus address (_ADR) then we utilize the parent's 1088 * 'bind' function (if exists) to bind the ACPI- and natively- 1089 * enumerated device representations. 1090 */ 1091 if (device->flags.bus_address) { 1092 if (device->parent && device->parent->ops.bind) 1093 device->parent->ops.bind(device); 1094 } 1095 1096 /* 1097 * Locate & Attach Driver 1098 * ---------------------- 1099 * If there's a hardware id (_HID) or compatible ids (_CID) we check 1100 * to see if there's a driver installed for this kind of device. Note 1101 * that drivers can install before or after a device is enumerated. 1102 * 1103 * TBD: Assumes LDM provides driver hot-plug capability. 1104 */ 1105 acpi_bus_find_driver(device); 1106 1107 end: 1108 if (!result) 1109 *child = device; 1110 else { 1111 kfree(device->pnp.cid_list); 1112 kfree(device); 1113 } 1114 1115 return result; 1116 } 1117 1118 static int acpi_bus_scan(struct acpi_device *start, struct acpi_bus_ops *ops) 1119 { 1120 acpi_status status = AE_OK; 1121 struct acpi_device *parent = NULL; 1122 struct acpi_device *child = NULL; 1123 acpi_handle phandle = NULL; 1124 acpi_handle chandle = NULL; 1125 acpi_object_type type = 0; 1126 u32 level = 1; 1127 1128 1129 if (!start) 1130 return -EINVAL; 1131 1132 parent = start; 1133 phandle = start->handle; 1134 1135 /* 1136 * Parse through the ACPI namespace, identify all 'devices', and 1137 * create a new 'struct acpi_device' for each. 1138 */ 1139 while ((level > 0) && parent) { 1140 1141 status = acpi_get_next_object(ACPI_TYPE_ANY, phandle, 1142 chandle, &chandle); 1143 1144 /* 1145 * If this scope is exhausted then move our way back up. 1146 */ 1147 if (ACPI_FAILURE(status)) { 1148 level--; 1149 chandle = phandle; 1150 acpi_get_parent(phandle, &phandle); 1151 if (parent->parent) 1152 parent = parent->parent; 1153 continue; 1154 } 1155 1156 status = acpi_get_type(chandle, &type); 1157 if (ACPI_FAILURE(status)) 1158 continue; 1159 1160 /* 1161 * If this is a scope object then parse it (depth-first). 1162 */ 1163 if (type == ACPI_TYPE_LOCAL_SCOPE) { 1164 level++; 1165 phandle = chandle; 1166 chandle = NULL; 1167 continue; 1168 } 1169 1170 /* 1171 * We're only interested in objects that we consider 'devices'. 1172 */ 1173 switch (type) { 1174 case ACPI_TYPE_DEVICE: 1175 type = ACPI_BUS_TYPE_DEVICE; 1176 break; 1177 case ACPI_TYPE_PROCESSOR: 1178 type = ACPI_BUS_TYPE_PROCESSOR; 1179 break; 1180 case ACPI_TYPE_THERMAL: 1181 type = ACPI_BUS_TYPE_THERMAL; 1182 break; 1183 case ACPI_TYPE_POWER: 1184 type = ACPI_BUS_TYPE_POWER; 1185 break; 1186 default: 1187 continue; 1188 } 1189 1190 if (ops->acpi_op_add) 1191 status = acpi_add_single_object(&child, parent, 1192 chandle, type); 1193 else 1194 status = acpi_bus_get_device(chandle, &child); 1195 1196 if (ACPI_FAILURE(status)) 1197 continue; 1198 1199 if (ops->acpi_op_start) { 1200 status = acpi_start_single_object(child); 1201 if (ACPI_FAILURE(status)) 1202 continue; 1203 } 1204 1205 /* 1206 * If the device is present, enabled, and functioning then 1207 * parse its scope (depth-first). Note that we need to 1208 * represent absent devices to facilitate PnP notifications 1209 * -- but only the subtree head (not all of its children, 1210 * which will be enumerated when the parent is inserted). 1211 * 1212 * TBD: Need notifications and other detection mechanisms 1213 * in place before we can fully implement this. 1214 */ 1215 if (child->status.present) { 1216 status = acpi_get_next_object(ACPI_TYPE_ANY, chandle, 1217 NULL, NULL); 1218 if (ACPI_SUCCESS(status)) { 1219 level++; 1220 phandle = chandle; 1221 chandle = NULL; 1222 parent = child; 1223 } 1224 } 1225 } 1226 1227 return 0; 1228 } 1229 1230 int 1231 acpi_bus_add(struct acpi_device **child, 1232 struct acpi_device *parent, acpi_handle handle, int type) 1233 { 1234 int result; 1235 struct acpi_bus_ops ops; 1236 1237 1238 result = acpi_add_single_object(child, parent, handle, type); 1239 if (!result) { 1240 memset(&ops, 0, sizeof(ops)); 1241 ops.acpi_op_add = 1; 1242 result = acpi_bus_scan(*child, &ops); 1243 } 1244 return result; 1245 } 1246 1247 EXPORT_SYMBOL(acpi_bus_add); 1248 1249 int acpi_bus_start(struct acpi_device *device) 1250 { 1251 int result; 1252 struct acpi_bus_ops ops; 1253 1254 1255 if (!device) 1256 return -EINVAL; 1257 1258 result = acpi_start_single_object(device); 1259 if (!result) { 1260 memset(&ops, 0, sizeof(ops)); 1261 ops.acpi_op_start = 1; 1262 result = acpi_bus_scan(device, &ops); 1263 } 1264 return result; 1265 } 1266 1267 EXPORT_SYMBOL(acpi_bus_start); 1268 1269 int acpi_bus_trim(struct acpi_device *start, int rmdevice) 1270 { 1271 acpi_status status; 1272 struct acpi_device *parent, *child; 1273 acpi_handle phandle, chandle; 1274 acpi_object_type type; 1275 u32 level = 1; 1276 int err = 0; 1277 1278 parent = start; 1279 phandle = start->handle; 1280 child = chandle = NULL; 1281 1282 while ((level > 0) && parent && (!err)) { 1283 status = acpi_get_next_object(ACPI_TYPE_ANY, phandle, 1284 chandle, &chandle); 1285 1286 /* 1287 * If this scope is exhausted then move our way back up. 1288 */ 1289 if (ACPI_FAILURE(status)) { 1290 level--; 1291 chandle = phandle; 1292 acpi_get_parent(phandle, &phandle); 1293 child = parent; 1294 parent = parent->parent; 1295 1296 if (level == 0) 1297 err = acpi_bus_remove(child, rmdevice); 1298 else 1299 err = acpi_bus_remove(child, 1); 1300 1301 continue; 1302 } 1303 1304 status = acpi_get_type(chandle, &type); 1305 if (ACPI_FAILURE(status)) { 1306 continue; 1307 } 1308 /* 1309 * If there is a device corresponding to chandle then 1310 * parse it (depth-first). 1311 */ 1312 if (acpi_bus_get_device(chandle, &child) == 0) { 1313 level++; 1314 phandle = chandle; 1315 chandle = NULL; 1316 parent = child; 1317 } 1318 continue; 1319 } 1320 return err; 1321 } 1322 EXPORT_SYMBOL_GPL(acpi_bus_trim); 1323 1324 1325 static int acpi_bus_scan_fixed(struct acpi_device *root) 1326 { 1327 int result = 0; 1328 struct acpi_device *device = NULL; 1329 1330 1331 if (!root) 1332 return -ENODEV; 1333 1334 /* 1335 * Enumerate all fixed-feature devices. 1336 */ 1337 if (acpi_fadt.pwr_button == 0) { 1338 result = acpi_add_single_object(&device, acpi_root, 1339 NULL, 1340 ACPI_BUS_TYPE_POWER_BUTTON); 1341 if (!result) 1342 result = acpi_start_single_object(device); 1343 } 1344 1345 if (acpi_fadt.sleep_button == 0) { 1346 result = acpi_add_single_object(&device, acpi_root, 1347 NULL, 1348 ACPI_BUS_TYPE_SLEEP_BUTTON); 1349 if (!result) 1350 result = acpi_start_single_object(device); 1351 } 1352 1353 return result; 1354 } 1355 1356 1357 static inline struct acpi_device * to_acpi_dev(struct device * dev) 1358 { 1359 return container_of(dev, struct acpi_device, dev); 1360 } 1361 1362 1363 static int root_suspend(struct acpi_device * acpi_dev, pm_message_t state) 1364 { 1365 struct acpi_device * dev, * next; 1366 int result; 1367 1368 spin_lock(&acpi_device_lock); 1369 list_for_each_entry_safe_reverse(dev, next, &acpi_device_list, g_list) { 1370 if (dev->driver && dev->driver->ops.suspend) { 1371 spin_unlock(&acpi_device_lock); 1372 result = dev->driver->ops.suspend(dev, 0); 1373 if (result) { 1374 printk(KERN_ERR PREFIX "[%s - %s] Suspend failed: %d\n", 1375 acpi_device_name(dev), 1376 acpi_device_bid(dev), result); 1377 } 1378 spin_lock(&acpi_device_lock); 1379 } 1380 } 1381 spin_unlock(&acpi_device_lock); 1382 return 0; 1383 } 1384 1385 1386 static int acpi_device_suspend(struct device * dev, pm_message_t state) 1387 { 1388 struct acpi_device * acpi_dev = to_acpi_dev(dev); 1389 1390 /* 1391 * For now, we should only register 1 generic device - 1392 * the ACPI root device - and from there, we walk the 1393 * tree of ACPI devices to suspend each one using the 1394 * ACPI driver methods. 1395 */ 1396 if (acpi_dev->handle == ACPI_ROOT_OBJECT) 1397 root_suspend(acpi_dev, state); 1398 return 0; 1399 } 1400 1401 1402 1403 static int root_resume(struct acpi_device * acpi_dev) 1404 { 1405 struct acpi_device * dev, * next; 1406 int result; 1407 1408 spin_lock(&acpi_device_lock); 1409 list_for_each_entry_safe(dev, next, &acpi_device_list, g_list) { 1410 if (dev->driver && dev->driver->ops.resume) { 1411 spin_unlock(&acpi_device_lock); 1412 result = dev->driver->ops.resume(dev, 0); 1413 if (result) { 1414 printk(KERN_ERR PREFIX "[%s - %s] resume failed: %d\n", 1415 acpi_device_name(dev), 1416 acpi_device_bid(dev), result); 1417 } 1418 spin_lock(&acpi_device_lock); 1419 } 1420 } 1421 spin_unlock(&acpi_device_lock); 1422 return 0; 1423 } 1424 1425 1426 static int acpi_device_resume(struct device * dev) 1427 { 1428 struct acpi_device * acpi_dev = to_acpi_dev(dev); 1429 1430 /* 1431 * For now, we should only register 1 generic device - 1432 * the ACPI root device - and from there, we walk the 1433 * tree of ACPI devices to resume each one using the 1434 * ACPI driver methods. 1435 */ 1436 if (acpi_dev->handle == ACPI_ROOT_OBJECT) 1437 root_resume(acpi_dev); 1438 return 0; 1439 } 1440 1441 1442 static struct bus_type acpi_bus_type = { 1443 .name = "acpi", 1444 .suspend = acpi_device_suspend, 1445 .resume = acpi_device_resume, 1446 }; 1447 1448 1449 1450 static int __init acpi_scan_init(void) 1451 { 1452 int result; 1453 struct acpi_bus_ops ops; 1454 1455 1456 if (acpi_disabled) 1457 return 0; 1458 1459 result = kset_register(&acpi_namespace_kset); 1460 if (result < 0) 1461 printk(KERN_ERR PREFIX "kset_register error: %d\n", result); 1462 1463 result = bus_register(&acpi_bus_type); 1464 if (result) { 1465 /* We don't want to quit even if we failed to add suspend/resume */ 1466 printk(KERN_ERR PREFIX "Could not register bus type\n"); 1467 } 1468 1469 /* 1470 * Create the root device in the bus's device tree 1471 */ 1472 result = acpi_add_single_object(&acpi_root, NULL, ACPI_ROOT_OBJECT, 1473 ACPI_BUS_TYPE_SYSTEM); 1474 if (result) 1475 goto Done; 1476 1477 result = acpi_start_single_object(acpi_root); 1478 if (result) 1479 goto Done; 1480 1481 acpi_root->dev.bus = &acpi_bus_type; 1482 snprintf(acpi_root->dev.bus_id, BUS_ID_SIZE, "%s", acpi_bus_type.name); 1483 result = device_register(&acpi_root->dev); 1484 if (result) { 1485 /* We don't want to quit even if we failed to add suspend/resume */ 1486 printk(KERN_ERR PREFIX "Could not register device\n"); 1487 } 1488 1489 /* 1490 * Enumerate devices in the ACPI namespace. 1491 */ 1492 result = acpi_bus_scan_fixed(acpi_root); 1493 if (!result) { 1494 memset(&ops, 0, sizeof(ops)); 1495 ops.acpi_op_add = 1; 1496 ops.acpi_op_start = 1; 1497 result = acpi_bus_scan(acpi_root, &ops); 1498 } 1499 1500 if (result) 1501 acpi_device_unregister(acpi_root, ACPI_BUS_REMOVAL_NORMAL); 1502 1503 Done: 1504 return result; 1505 } 1506 1507 subsys_initcall(acpi_scan_init); 1508