drivers/acpi/scan.c

   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 int acpi_bus_remove(struct acpi_device *dev, int rmdevice)
 892 {
 893         int result = 0;
 894         struct acpi_driver *driver;
 895
 896
 897         if (!dev)
 898                 return -EINVAL;
 899
 900         driver = dev->driver;
 901
 902         if ((driver) && (driver->ops.remove)) {
 903
 904                 if (driver->ops.stop) {
 905                         result = driver->ops.stop(dev, ACPI_BUS_REMOVAL_EJECT);
 906                         if (result)
 907                                 return result;
 908                 }
 909
 910                 result = dev->driver->ops.remove(dev, ACPI_BUS_REMOVAL_EJECT);
 911                 if (result) {
 912                         return result;
 913                 }
 914
 915                 atomic_dec(&dev->driver->references);
 916                 dev->driver = NULL;
 917                 acpi_driver_data(dev) = NULL;
 918         }
 919
 920         if (!rmdevice)
 921                 return 0;
 922
 923         if (dev->flags.bus_address) {
 924                 if ((dev->parent) && (dev->parent->ops.unbind))
 925                         dev->parent->ops.unbind(dev);
 926         }
 927
 928         acpi_device_unregister(dev, ACPI_BUS_REMOVAL_EJECT);
 929
 930         return 0;
 931 }
 932
 933 static int
 934 acpi_add_single_object(struct acpi_device **child,
 935                        struct acpi_device *parent, acpi_handle handle, int type)
 936 {
 937         int result = 0;
 938         struct acpi_device *device = NULL;
 939
 940
 941         if (!child)
 942                 return -EINVAL;
 943
 944         device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
 945         if (!device) {
 946                 printk(KERN_ERR PREFIX "Memory allocation error\n");
 947                 return -ENOMEM;
 948         }
 949
 950         device->handle = handle;
 951         device->parent = parent;
 952
 953         acpi_device_get_busid(device, handle, type);
 954
 955         /*
 956          * Flags
 957          * -----
 958          * Get prior to calling acpi_bus_get_status() so we know whether
 959          * or not _STA is present.  Note that we only look for object
 960          * handles -- cannot evaluate objects until we know the device is
 961          * present and properly initialized.
 962          */
 963         result = acpi_bus_get_flags(device);
 964         if (result)
 965                 goto end;
 966
 967         /*
 968          * Status
 969          * ------
 970          * See if the device is present.  We always assume that non-Device
 971          * and non-Processor objects (e.g. thermal zones, power resources,
 972          * etc.) are present, functioning, etc. (at least when parent object
 973          * is present).  Note that _STA has a different meaning for some
 974          * objects (e.g. power resources) so we need to be careful how we use
 975          * it.
 976          */
 977         switch (type) {
 978         case ACPI_BUS_TYPE_PROCESSOR:
 979         case ACPI_BUS_TYPE_DEVICE:
 980                 result = acpi_bus_get_status(device);
 981                 if (ACPI_FAILURE(result) || !device->status.present) {
 982                         result = -ENOENT;
 983                         goto end;
 984                 }
 985                 break;
 986         default:
 987                 STRUCT_TO_INT(device->status) = 0x0F;
 988                 break;
 989         }
 990
 991         /*
 992          * Initialize Device
 993          * -----------------
 994          * TBD: Synch with Core's enumeration/initialization process.
 995          */
 996
 997         /*
 998          * Hardware ID, Unique ID, & Bus Address
 999          * -------------------------------------
1000          */
1001         acpi_device_set_id(device, parent, handle, type);
1002
1003         /*
1004          * Power Management
1005          * ----------------
1006          */
1007         if (device->flags.power_manageable) {
1008                 result = acpi_bus_get_power_flags(device);
1009                 if (result)
1010                         goto end;
1011         }
1012
1013         /*
1014          * Wakeup device management
1015          *-----------------------
1016          */
1017         if (device->flags.wake_capable) {
1018                 result = acpi_bus_get_wakeup_device_flags(device);
1019                 if (result)
1020                         goto end;
1021         }
1022
1023         /*
1024          * Performance Management
1025          * ----------------------
1026          */
1027         if (device->flags.performance_manageable) {
1028                 result = acpi_bus_get_perf_flags(device);
1029                 if (result)
1030                         goto end;
1031         }
1032
1033         if ((result = acpi_device_set_context(device, type)))
1034                 goto end;
1035
1036         acpi_device_register(device, parent);
1037
1038         /*
1039          * Bind _ADR-Based Devices
1040          * -----------------------
1041          * If there's a a bus address (_ADR) then we utilize the parent's
1042          * 'bind' function (if exists) to bind the ACPI- and natively-
1043          * enumerated device representations.
1044          */
1045         if (device->flags.bus_address) {
1046                 if (device->parent && device->parent->ops.bind)
1047                         device->parent->ops.bind(device);
1048         }
1049
1050         /*
1051          * Locate & Attach Driver
1052          * ----------------------
1053          * If there's a hardware id (_HID) or compatible ids (_CID) we check
1054          * to see if there's a driver installed for this kind of device.  Note
1055          * that drivers can install before or after a device is enumerated.
1056          *
1057          * TBD: Assumes LDM provides driver hot-plug capability.
1058          */
1059         acpi_bus_find_driver(device);
1060
1061       end:
1062         if (!result)
1063                 *child = device;
1064         else {
1065                 kfree(device->pnp.cid_list);
1066                 kfree(device);
1067         }
1068
1069         return result;
1070 }
1071
1072 static int acpi_bus_scan(struct acpi_device *start, struct acpi_bus_ops *ops)
1073 {
1074         acpi_status status = AE_OK;
1075         struct acpi_device *parent = NULL;
1076         struct acpi_device *child = NULL;
1077         acpi_handle phandle = NULL;
1078         acpi_handle chandle = NULL;
1079         acpi_object_type type = 0;
1080         u32 level = 1;
1081
1082
1083         if (!start)
1084                 return -EINVAL;
1085
1086         parent = start;
1087         phandle = start->handle;
1088
1089         /*
1090          * Parse through the ACPI namespace, identify all 'devices', and
1091          * create a new 'struct acpi_device' for each.
1092          */
1093         while ((level > 0) && parent) {
1094
1095                 status = acpi_get_next_object(ACPI_TYPE_ANY, phandle,
1096                                               chandle, &chandle);
1097
1098                 /*
1099                  * If this scope is exhausted then move our way back up.
1100                  */
1101                 if (ACPI_FAILURE(status)) {
1102                         level--;
1103                         chandle = phandle;
1104                         acpi_get_parent(phandle, &phandle);
1105                         if (parent->parent)
1106                                 parent = parent->parent;
1107                         continue;
1108                 }
1109
1110                 status = acpi_get_type(chandle, &type);
1111                 if (ACPI_FAILURE(status))
1112                         continue;
1113
1114                 /*
1115                  * If this is a scope object then parse it (depth-first).
1116                  */
1117                 if (type == ACPI_TYPE_LOCAL_SCOPE) {
1118                         level++;
1119                         phandle = chandle;
1120                         chandle = NULL;
1121                         continue;
1122                 }
1123
1124                 /*
1125                  * We're only interested in objects that we consider 'devices'.
1126                  */
1127                 switch (type) {
1128                 case ACPI_TYPE_DEVICE:
1129                         type = ACPI_BUS_TYPE_DEVICE;
1130                         break;
1131                 case ACPI_TYPE_PROCESSOR:
1132                         type = ACPI_BUS_TYPE_PROCESSOR;
1133                         break;
1134                 case ACPI_TYPE_THERMAL:
1135                         type = ACPI_BUS_TYPE_THERMAL;
1136                         break;
1137                 case ACPI_TYPE_POWER:
1138                         type = ACPI_BUS_TYPE_POWER;
1139                         break;
1140                 default:
1141                         continue;
1142                 }
1143
1144                 if (ops->acpi_op_add)
1145                         status = acpi_add_single_object(&child, parent,
1146                                                         chandle, type);
1147                 else
1148                         status = acpi_bus_get_device(chandle, &child);
1149
1150                 if (ACPI_FAILURE(status))
1151                         continue;
1152
1153                 if (ops->acpi_op_start) {
1154                         status = acpi_start_single_object(child);
1155                         if (ACPI_FAILURE(status))
1156                                 continue;
1157                 }
1158
1159                 /*
1160                  * If the device is present, enabled, and functioning then
1161                  * parse its scope (depth-first).  Note that we need to
1162                  * represent absent devices to facilitate PnP notifications
1163                  * -- but only the subtree head (not all of its children,
1164                  * which will be enumerated when the parent is inserted).
1165                  *
1166                  * TBD: Need notifications and other detection mechanisms
1167                  *      in place before we can fully implement this.
1168                  */
1169                 if (child->status.present) {
1170                         status = acpi_get_next_object(ACPI_TYPE_ANY, chandle,
1171                                                       NULL, NULL);
1172                         if (ACPI_SUCCESS(status)) {
1173                                 level++;
1174                                 phandle = chandle;
1175                                 chandle = NULL;
1176                                 parent = child;
1177                         }
1178                 }
1179         }
1180
1181         return 0;
1182 }
1183
1184 int
1185 acpi_bus_add(struct acpi_device **child,
1186              struct acpi_device *parent, acpi_handle handle, int type)
1187 {
1188         int result;
1189         struct acpi_bus_ops ops;
1190
1191
1192         result = acpi_add_single_object(child, parent, handle, type);
1193         if (!result) {
1194                 memset(&ops, 0, sizeof(ops));
1195                 ops.acpi_op_add = 1;
1196                 result = acpi_bus_scan(*child, &ops);
1197         }
1198         return result;
1199 }
1200
1201 EXPORT_SYMBOL(acpi_bus_add);
1202
1203 int acpi_bus_start(struct acpi_device *device)
1204 {
1205         int result;
1206         struct acpi_bus_ops ops;
1207
1208
1209         if (!device)
1210                 return -EINVAL;
1211
1212         result = acpi_start_single_object(device);
1213         if (!result) {
1214                 memset(&ops, 0, sizeof(ops));
1215                 ops.acpi_op_start = 1;
1216                 result = acpi_bus_scan(device, &ops);
1217         }
1218         return result;
1219 }
1220
1221 EXPORT_SYMBOL(acpi_bus_start);
1222
1223 int acpi_bus_trim(struct acpi_device *start, int rmdevice)
1224 {
1225         acpi_status status;
1226         struct acpi_device *parent, *child;
1227         acpi_handle phandle, chandle;
1228         acpi_object_type type;
1229         u32 level = 1;
1230         int err = 0;
1231
1232         parent = start;
1233         phandle = start->handle;
1234         child = chandle = NULL;
1235
1236         while ((level > 0) && parent && (!err)) {
1237                 status = acpi_get_next_object(ACPI_TYPE_ANY, phandle,
1238                                               chandle, &chandle);
1239
1240                 /*
1241                  * If this scope is exhausted then move our way back up.
1242                  */
1243                 if (ACPI_FAILURE(status)) {
1244                         level--;
1245                         chandle = phandle;
1246                         acpi_get_parent(phandle, &phandle);
1247                         child = parent;
1248                         parent = parent->parent;
1249
1250                         if (level == 0)
1251                                 err = acpi_bus_remove(child, rmdevice);
1252                         else
1253                                 err = acpi_bus_remove(child, 1);
1254
1255                         continue;
1256                 }
1257
1258                 status = acpi_get_type(chandle, &type);
1259                 if (ACPI_FAILURE(status)) {
1260                         continue;
1261                 }
1262                 /*
1263                  * If there is a device corresponding to chandle then
1264                  * parse it (depth-first).
1265                  */
1266                 if (acpi_bus_get_device(chandle, &child) == 0) {
1267                         level++;
1268                         phandle = chandle;
1269                         chandle = NULL;
1270                         parent = child;
1271                 }
1272                 continue;
1273         }
1274         return err;
1275 }
1276 EXPORT_SYMBOL_GPL(acpi_bus_trim);
1277
1278
1279 static int acpi_bus_scan_fixed(struct acpi_device *root)
1280 {
1281         int result = 0;
1282         struct acpi_device *device = NULL;
1283
1284
1285         if (!root)
1286                 return -ENODEV;
1287
1288         /*
1289          * Enumerate all fixed-feature devices.
1290          */
1291         if (acpi_fadt.pwr_button == 0) {
1292                 result = acpi_add_single_object(&device, acpi_root,
1293                                                 NULL,
1294                                                 ACPI_BUS_TYPE_POWER_BUTTON);
1295                 if (!result)
1296                         result = acpi_start_single_object(device);
1297         }
1298
1299         if (acpi_fadt.sleep_button == 0) {
1300                 result = acpi_add_single_object(&device, acpi_root,
1301                                                 NULL,
1302                                                 ACPI_BUS_TYPE_SLEEP_BUTTON);
1303                 if (!result)
1304                         result = acpi_start_single_object(device);
1305         }
1306
1307         return result;
1308 }
1309
1310
1311 static inline struct acpi_device * to_acpi_dev(struct device * dev)
1312 {
1313         return container_of(dev, struct acpi_device, dev);
1314 }
1315
1316
1317 static int root_suspend(struct acpi_device * acpi_dev, pm_message_t state)
1318 {
1319         struct acpi_device * dev, * next;
1320         int result;
1321
1322         spin_lock(&acpi_device_lock);
1323         list_for_each_entry_safe_reverse(dev, next, &acpi_device_list, g_list) {
1324                 if (dev->driver && dev->driver->ops.suspend) {
1325                         spin_unlock(&acpi_device_lock);
1326                         result = dev->driver->ops.suspend(dev, 0);
1327                         if (result) {
1328                                 printk(KERN_ERR PREFIX "[%s - %s] Suspend failed: %d\n",
1329                                        acpi_device_name(dev),
1330                                        acpi_device_bid(dev), result);
1331                         }
1332                         spin_lock(&acpi_device_lock);
1333                 }
1334         }
1335         spin_unlock(&acpi_device_lock);
1336         return 0;
1337 }
1338
1339
1340 static int acpi_device_suspend(struct device * dev, pm_message_t state)
1341 {
1342         struct acpi_device * acpi_dev = to_acpi_dev(dev);
1343
1344         /*
1345          * For now, we should only register 1 generic device -
1346          * the ACPI root device - and from there, we walk the
1347          * tree of ACPI devices to suspend each one using the
1348          * ACPI driver methods.
1349          */
1350         if (acpi_dev->handle == ACPI_ROOT_OBJECT)
1351                 root_suspend(acpi_dev, state);
1352         return 0;
1353 }
1354
1355
1356
1357 static int root_resume(struct acpi_device * acpi_dev)
1358 {
1359         struct acpi_device * dev, * next;
1360         int result;
1361
1362         spin_lock(&acpi_device_lock);
1363         list_for_each_entry_safe(dev, next, &acpi_device_list, g_list) {
1364                 if (dev->driver && dev->driver->ops.resume) {
1365                         spin_unlock(&acpi_device_lock);
1366                         result = dev->driver->ops.resume(dev, 0);
1367                         if (result) {
1368                                 printk(KERN_ERR PREFIX "[%s - %s] resume failed: %d\n",
1369                                        acpi_device_name(dev),
1370                                        acpi_device_bid(dev), result);
1371                         }
1372                         spin_lock(&acpi_device_lock);
1373                 }
1374         }
1375         spin_unlock(&acpi_device_lock);
1376         return 0;
1377 }
1378
1379
1380 static int acpi_device_resume(struct device * dev)
1381 {
1382         struct acpi_device * acpi_dev = to_acpi_dev(dev);
1383
1384         /*
1385          * For now, we should only register 1 generic device -
1386          * the ACPI root device - and from there, we walk the
1387          * tree of ACPI devices to resume each one using the
1388          * ACPI driver methods.
1389          */
1390         if (acpi_dev->handle == ACPI_ROOT_OBJECT)
1391                 root_resume(acpi_dev);
1392         return 0;
1393 }
1394
1395
1396 static struct bus_type acpi_bus_type = {
1397         .name           = "acpi",
1398         .suspend        = acpi_device_suspend,
1399         .resume         = acpi_device_resume,
1400 };
1401
1402
1403
1404 static int __init acpi_scan_init(void)
1405 {
1406         int result;
1407         struct acpi_bus_ops ops;
1408
1409
1410         if (acpi_disabled)
1411                 return 0;
1412
1413         result = kset_register(&acpi_namespace_kset);
1414         if (result < 0)
1415                 printk(KERN_ERR PREFIX "kset_register error: %d\n", result);
1416
1417         result = bus_register(&acpi_bus_type);
1418         if (result) {
1419                 /* We don't want to quit even if we failed to add suspend/resume */
1420                 printk(KERN_ERR PREFIX "Could not register bus type\n");
1421         }
1422
1423         /*
1424          * Create the root device in the bus's device tree
1425          */
1426         result = acpi_add_single_object(&acpi_root, NULL, ACPI_ROOT_OBJECT,
1427                                         ACPI_BUS_TYPE_SYSTEM);
1428         if (result)
1429                 goto Done;
1430
1431         result = acpi_start_single_object(acpi_root);
1432         if (result)
1433                 goto Done;
1434
1435         acpi_root->dev.bus = &acpi_bus_type;
1436         snprintf(acpi_root->dev.bus_id, BUS_ID_SIZE, "%s", acpi_bus_type.name);
1437         result = device_register(&acpi_root->dev);
1438         if (result) {
1439                 /* We don't want to quit even if we failed to add suspend/resume */
1440                 printk(KERN_ERR PREFIX "Could not register device\n");
1441         }
1442
1443         /*
1444          * Enumerate devices in the ACPI namespace.
1445          */
1446         result = acpi_bus_scan_fixed(acpi_root);
1447         if (!result) {
1448                 memset(&ops, 0, sizeof(ops));
1449                 ops.acpi_op_add = 1;
1450                 ops.acpi_op_start = 1;
1451                 result = acpi_bus_scan(acpi_root, &ops);
1452         }
1453
1454         if (result)
1455                 acpi_device_unregister(acpi_root, ACPI_BUS_REMOVAL_NORMAL);
1456
1457       Done:
1458         return result;
1459 }
1460
1461 subsys_initcall(acpi_scan_init);