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