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 static LIST_HEAD(acpi_bus_id_list);
  25 DEFINE_SPINLOCK(acpi_device_lock);
  26 LIST_HEAD(acpi_wakeup_device_list);
  27
  28 struct acpi_device_bus_id{
  29         char bus_id[15];
  30         unsigned int instance_no;
  31         struct list_head node;
  32 };
  33 static int acpi_eject_operation(acpi_handle handle, int lockable)
  34 {
  35         struct acpi_object_list arg_list;
  36         union acpi_object arg;
  37         acpi_status status = AE_OK;
  38
  39         /*
  40          * TBD: evaluate _PS3?
  41          */
  42
  43         if (lockable) {
  44                 arg_list.count = 1;
  45                 arg_list.pointer = &arg;
  46                 arg.type = ACPI_TYPE_INTEGER;
  47                 arg.integer.value = 0;
  48                 acpi_evaluate_object(handle, "_LCK", &arg_list, NULL);
  49         }
  50
  51         arg_list.count = 1;
  52         arg_list.pointer = &arg;
  53         arg.type = ACPI_TYPE_INTEGER;
  54         arg.integer.value = 1;
  55
  56         /*
  57          * TBD: _EJD support.
  58          */
  59
  60         status = acpi_evaluate_object(handle, "_EJ0", &arg_list, NULL);
  61         if (ACPI_FAILURE(status)) {
  62                 return (-ENODEV);
  63         }
  64
  65         return (0);
  66 }
  67
  68 static ssize_t
  69 acpi_eject_store(struct device *d, struct device_attribute *attr,
  70                 const char *buf, size_t count)
  71 {
  72         int result;
  73         int ret = count;
  74         int islockable;
  75         acpi_status status;
  76         acpi_handle handle;
  77         acpi_object_type type = 0;
  78         struct acpi_device *acpi_device = to_acpi_device(d);
  79
  80         if ((!count) || (buf[0] != '1')) {
  81                 return -EINVAL;
  82         }
  83 #ifndef FORCE_EJECT
  84         if (acpi_device->driver == NULL) {
  85                 ret = -ENODEV;
  86                 goto err;
  87         }
  88 #endif
  89         status = acpi_get_type(acpi_device->handle, &type);
  90         if (ACPI_FAILURE(status) || (!acpi_device->flags.ejectable)) {
  91                 ret = -ENODEV;
  92                 goto err;
  93         }
  94
  95         islockable = acpi_device->flags.lockable;
  96         handle = acpi_device->handle;
  97
  98         result = acpi_bus_trim(acpi_device, 1);
  99
 100         if (!result)
 101                 result = acpi_eject_operation(handle, islockable);
 102
 103         if (result) {
 104                 ret = -EBUSY;
 105         }
 106       err:
 107         return ret;
 108 }
 109
 110 static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
 111
 112 static ssize_t
 113 acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
 114         struct acpi_device *acpi_dev = to_acpi_device(dev);
 115
 116         return sprintf(buf, "%s\n", acpi_dev->pnp.hardware_id);
 117 }
 118 static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
 119
 120 static ssize_t
 121 acpi_device_path_show(struct device *dev, struct device_attribute *attr, char *buf) {
 122         struct acpi_device *acpi_dev = to_acpi_device(dev);
 123         struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
 124         int result;
 125
 126         result = acpi_get_name(acpi_dev->handle, ACPI_FULL_PATHNAME, &path);
 127         if(result)
 128                 goto end;
 129
 130         result = sprintf(buf, "%s\n", (char*)path.pointer);
 131         kfree(path.pointer);
 132   end:
 133         return result;
 134 }
 135 static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
 136
 137 static int acpi_device_setup_files(struct acpi_device *dev)
 138 {
 139         acpi_status status;
 140         acpi_handle temp;
 141         int result = 0;
 142
 143         /*
 144          * Devices gotten from FADT don't have a "path" attribute
 145          */
 146         if(dev->handle) {
 147                 result = device_create_file(&dev->dev, &dev_attr_path);
 148                 if(result)
 149                         goto end;
 150         }
 151
 152         if(dev->flags.hardware_id) {
 153                 result = device_create_file(&dev->dev, &dev_attr_hid);
 154                 if(result)
 155                         goto end;
 156         }
 157
 158         /*
 159          * If device has _EJ0, 'eject' file is created that is used to trigger
 160          * hot-removal function from userland.
 161          */
 162         status = acpi_get_handle(dev->handle, "_EJ0", &temp);
 163         if (ACPI_SUCCESS(status))
 164                 result = device_create_file(&dev->dev, &dev_attr_eject);
 165   end:
 166         return result;
 167 }
 168
 169 static void acpi_device_remove_files(struct acpi_device *dev)
 170 {
 171         acpi_status status;
 172         acpi_handle temp;
 173
 174         /*
 175          * If device has _EJ0, 'eject' file is created that is used to trigger
 176          * hot-removal function from userland.
 177          */
 178         status = acpi_get_handle(dev->handle, "_EJ0", &temp);
 179         if (ACPI_SUCCESS(status))
 180                 device_remove_file(&dev->dev, &dev_attr_eject);
 181
 182         if(dev->flags.hardware_id)
 183                 device_remove_file(&dev->dev, &dev_attr_hid);
 184         if(dev->handle)
 185                 device_remove_file(&dev->dev, &dev_attr_path);
 186 }
 187 /* --------------------------------------------------------------------------
 188                         ACPI Bus operations
 189    -------------------------------------------------------------------------- */
 190 static void acpi_device_release(struct device *dev)
 191 {
 192         struct acpi_device *acpi_dev = to_acpi_device(dev);
 193
 194         kfree(acpi_dev->pnp.cid_list);
 195         kfree(acpi_dev);
 196 }
 197
 198 static int acpi_device_suspend(struct device *dev, pm_message_t state)
 199 {
 200         struct acpi_device *acpi_dev = to_acpi_device(dev);
 201         struct acpi_driver *acpi_drv = acpi_dev->driver;
 202
 203         if (acpi_drv && acpi_drv->ops.suspend)
 204                 return acpi_drv->ops.suspend(acpi_dev, state);
 205         return 0;
 206 }
 207
 208 static int acpi_device_resume(struct device *dev)
 209 {
 210         struct acpi_device *acpi_dev = to_acpi_device(dev);
 211         struct acpi_driver *acpi_drv = acpi_dev->driver;
 212
 213         if (acpi_drv && acpi_drv->ops.resume)
 214                 return acpi_drv->ops.resume(acpi_dev);
 215         return 0;
 216 }
 217
 218 static int acpi_bus_match(struct device *dev, struct device_driver *drv)
 219 {
 220         struct acpi_device *acpi_dev = to_acpi_device(dev);
 221         struct acpi_driver *acpi_drv = to_acpi_driver(drv);
 222
 223         return !acpi_match_ids(acpi_dev, acpi_drv->ids);
 224 }
 225
 226 static int acpi_device_uevent(struct device *dev, char **envp, int num_envp,
 227         char *buffer, int buffer_size)
 228 {
 229         struct acpi_device *acpi_dev = to_acpi_device(dev);
 230         int i = 0, length = 0, ret = 0;
 231
 232         if (acpi_dev->flags.hardware_id)
 233                 ret = add_uevent_var(envp, num_envp, &i,
 234                         buffer, buffer_size, &length,
 235                         "HWID=%s", acpi_dev->pnp.hardware_id);
 236         if (ret)
 237                 return -ENOMEM;
 238         if (acpi_dev->flags.compatible_ids) {
 239                 int j;
 240                 struct acpi_compatible_id_list *cid_list;
 241
 242                 cid_list = acpi_dev->pnp.cid_list;
 243
 244                 for (j = 0; j < cid_list->count; j++) {
 245                         ret = add_uevent_var(envp, num_envp, &i, buffer,
 246                                 buffer_size, &length, "COMPTID=%s",
 247                                 cid_list->id[j].value);
 248                         if (ret)
 249                                 return -ENOMEM;
 250                 }
 251         }
 252
 253         envp[i] = NULL;
 254         return 0;
 255 }
 256
 257 static int acpi_bus_driver_init(struct acpi_device *, struct acpi_driver *);
 258 static int acpi_start_single_object(struct acpi_device *);
 259 static int acpi_device_probe(struct device * dev)
 260 {
 261         struct acpi_device *acpi_dev = to_acpi_device(dev);
 262         struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
 263         int ret;
 264
 265         ret = acpi_bus_driver_init(acpi_dev, acpi_drv);
 266         if (!ret) {
 267                 if (acpi_dev->bus_ops.acpi_op_start)
 268                         acpi_start_single_object(acpi_dev);
 269                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 270                         "Found driver [%s] for device [%s]\n",
 271                         acpi_drv->name, acpi_dev->pnp.bus_id));
 272                 get_device(dev);
 273         }
 274         return ret;
 275 }
 276
 277 static int acpi_device_remove(struct device * dev)
 278 {
 279         struct acpi_device *acpi_dev = to_acpi_device(dev);
 280         struct acpi_driver *acpi_drv = acpi_dev->driver;
 281
 282         if (acpi_drv) {
 283                 if (acpi_drv->ops.stop)
 284                         acpi_drv->ops.stop(acpi_dev, acpi_dev->removal_type);
 285                 if (acpi_drv->ops.remove)
 286                         acpi_drv->ops.remove(acpi_dev, acpi_dev->removal_type);
 287         }
 288         acpi_dev->driver = NULL;
 289         acpi_driver_data(dev) = NULL;
 290
 291         put_device(dev);
 292         return 0;
 293 }
 294
 295 static void acpi_device_shutdown(struct device *dev)
 296 {
 297         struct acpi_device *acpi_dev = to_acpi_device(dev);
 298         struct acpi_driver *acpi_drv = acpi_dev->driver;
 299
 300         if (acpi_drv && acpi_drv->ops.shutdown)
 301                 acpi_drv->ops.shutdown(acpi_dev);
 302
 303         return ;
 304 }
 305
 306 static struct bus_type acpi_bus_type = {
 307         .name           = "acpi",
 308         .suspend        = acpi_device_suspend,
 309         .resume         = acpi_device_resume,
 310         .shutdown       = acpi_device_shutdown,
 311         .match          = acpi_bus_match,
 312         .probe          = acpi_device_probe,
 313         .remove         = acpi_device_remove,
 314         .uevent         = acpi_device_uevent,
 315 };
 316
 317 static int acpi_device_register(struct acpi_device *device,
 318                                  struct acpi_device *parent)
 319 {
 320         int result;
 321         struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
 322         int found = 0;
 323         /*
 324          * Linkage
 325          * -------
 326          * Link this device to its parent and siblings.
 327          */
 328         INIT_LIST_HEAD(&device->children);
 329         INIT_LIST_HEAD(&device->node);
 330         INIT_LIST_HEAD(&device->g_list);
 331         INIT_LIST_HEAD(&device->wakeup_list);
 332
 333         new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
 334         if (!new_bus_id) {
 335                 printk(KERN_ERR PREFIX "Memory allocation error\n");
 336                 return -ENOMEM;
 337         }
 338
 339         spin_lock(&acpi_device_lock);
 340         /*
 341          * Find suitable bus_id and instance number in acpi_bus_id_list
 342          * If failed, create one and link it into acpi_bus_id_list
 343          */
 344         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
 345                 if(!strcmp(acpi_device_bus_id->bus_id, device->flags.hardware_id? device->pnp.hardware_id : "device")) {
 346                         acpi_device_bus_id->instance_no ++;
 347                         found = 1;
 348                         kfree(new_bus_id);
 349                         break;
 350                 }
 351         }
 352         if(!found) {
 353                 acpi_device_bus_id = new_bus_id;
 354                 strcpy(acpi_device_bus_id->bus_id, device->flags.hardware_id ? device->pnp.hardware_id : "device");
 355                 acpi_device_bus_id->instance_no = 0;
 356                 list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
 357         }
 358         sprintf(device->dev.bus_id, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
 359
 360         if (device->parent) {
 361                 list_add_tail(&device->node, &device->parent->children);
 362                 list_add_tail(&device->g_list, &device->parent->g_list);
 363         } else
 364                 list_add_tail(&device->g_list, &acpi_device_list);
 365         if (device->wakeup.flags.valid)
 366                 list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
 367         spin_unlock(&acpi_device_lock);
 368
 369         if (device->parent)
 370                 device->dev.parent = &parent->dev;
 371         device->dev.bus = &acpi_bus_type;
 372         device_initialize(&device->dev);
 373         device->dev.release = &acpi_device_release;
 374         result = device_add(&device->dev);
 375         if(result) {
 376                 printk("Error adding device %s", device->dev.bus_id);
 377                 goto end;
 378         }
 379
 380         result = acpi_device_setup_files(device);
 381         if(result)
 382                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error creating sysfs interface for device %s\n", device->dev.bus_id));
 383
 384         device->removal_type = ACPI_BUS_REMOVAL_NORMAL;
 385         return 0;
 386   end:
 387         spin_lock(&acpi_device_lock);
 388         if (device->parent) {
 389                 list_del(&device->node);
 390                 list_del(&device->g_list);
 391         } else
 392                 list_del(&device->g_list);
 393         list_del(&device->wakeup_list);
 394         spin_unlock(&acpi_device_lock);
 395         return result;
 396 }
 397
 398 static void acpi_device_unregister(struct acpi_device *device, int type)
 399 {
 400         spin_lock(&acpi_device_lock);
 401         if (device->parent) {
 402                 list_del(&device->node);
 403                 list_del(&device->g_list);
 404         } else
 405                 list_del(&device->g_list);
 406
 407         list_del(&device->wakeup_list);
 408         spin_unlock(&acpi_device_lock);
 409
 410         acpi_detach_data(device->handle, acpi_bus_data_handler);
 411
 412         acpi_device_remove_files(device);
 413         device_unregister(&device->dev);
 414 }
 415
 416 /* --------------------------------------------------------------------------
 417                                  Driver Management
 418    -------------------------------------------------------------------------- */
 419 /**
 420  * acpi_bus_driver_init - add a device to a driver
 421  * @device: the device to add and initialize
 422  * @driver: driver for the device
 423  *
 424  * Used to initialize a device via its device driver.  Called whenever a
 425  * driver is bound to a device.  Invokes the driver's add() ops.
 426  */
 427 static int
 428 acpi_bus_driver_init(struct acpi_device *device, struct acpi_driver *driver)
 429 {
 430         int result = 0;
 431
 432
 433         if (!device || !driver)
 434                 return -EINVAL;
 435
 436         if (!driver->ops.add)
 437                 return -ENOSYS;
 438
 439         result = driver->ops.add(device);
 440         if (result) {
 441                 device->driver = NULL;
 442                 acpi_driver_data(device) = NULL;
 443                 return result;
 444         }
 445
 446         device->driver = driver;
 447
 448         /*
 449          * TBD - Configuration Management: Assign resources to device based
 450          * upon possible configuration and currently allocated resources.
 451          */
 452
 453         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 454                           "Driver successfully bound to device\n"));
 455         return 0;
 456 }
 457
 458 static int acpi_start_single_object(struct acpi_device *device)
 459 {
 460         int result = 0;
 461         struct acpi_driver *driver;
 462
 463
 464         if (!(driver = device->driver))
 465                 return 0;
 466
 467         if (driver->ops.start) {
 468                 result = driver->ops.start(device);
 469                 if (result && driver->ops.remove)
 470                         driver->ops.remove(device, ACPI_BUS_REMOVAL_NORMAL);
 471         }
 472
 473         return result;
 474 }
 475
 476 /**
 477  * acpi_bus_register_driver - register a driver with the ACPI bus
 478  * @driver: driver being registered
 479  *
 480  * Registers a driver with the ACPI bus.  Searches the namespace for all
 481  * devices that match the driver's criteria and binds.  Returns zero for
 482  * success or a negative error status for failure.
 483  */
 484 int acpi_bus_register_driver(struct acpi_driver *driver)
 485 {
 486         int ret;
 487
 488         if (acpi_disabled)
 489                 return -ENODEV;
 490         driver->drv.name = driver->name;
 491         driver->drv.bus = &acpi_bus_type;
 492         driver->drv.owner = driver->owner;
 493
 494         ret = driver_register(&driver->drv);
 495         return ret;
 496 }
 497
 498 EXPORT_SYMBOL(acpi_bus_register_driver);
 499
 500 /**
 501  * acpi_bus_unregister_driver - unregisters a driver with the APIC bus
 502  * @driver: driver to unregister
 503  *
 504  * Unregisters a driver with the ACPI bus.  Searches the namespace for all
 505  * devices that match the driver's criteria and unbinds.
 506  */
 507 void acpi_bus_unregister_driver(struct acpi_driver *driver)
 508 {
 509         driver_unregister(&driver->drv);
 510 }
 511
 512 EXPORT_SYMBOL(acpi_bus_unregister_driver);
 513
 514 /* --------------------------------------------------------------------------
 515                                  Device Enumeration
 516    -------------------------------------------------------------------------- */
 517 acpi_status
 518 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
 519 {
 520         acpi_status status;
 521         acpi_handle tmp;
 522         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 523         union acpi_object *obj;
 524
 525         status = acpi_get_handle(handle, "_EJD", &tmp);
 526         if (ACPI_FAILURE(status))
 527                 return status;
 528
 529         status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
 530         if (ACPI_SUCCESS(status)) {
 531                 obj = buffer.pointer;
 532                 status = acpi_get_handle(NULL, obj->string.pointer, ejd);
 533                 kfree(buffer.pointer);
 534         }
 535         return status;
 536 }
 537 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
 538
 539 void acpi_bus_data_handler(acpi_handle handle, u32 function, void *context)
 540 {
 541
 542         /* TBD */
 543
 544         return;
 545 }
 546
 547 int acpi_match_ids(struct acpi_device *device, char *ids)
 548 {
 549         if (device->flags.hardware_id)
 550                 if (strstr(ids, device->pnp.hardware_id))
 551                         return 0;
 552
 553         if (device->flags.compatible_ids) {
 554                 struct acpi_compatible_id_list *cid_list = device->pnp.cid_list;
 555                 int i;
 556
 557                 /* compare multiple _CID entries against driver ids */
 558                 for (i = 0; i < cid_list->count; i++) {
 559                         if (strstr(ids, cid_list->id[i].value))
 560                                 return 0;
 561                 }
 562         }
 563         return -ENOENT;
 564 }
 565
 566 static int acpi_bus_get_perf_flags(struct acpi_device *device)
 567 {
 568         device->performance.state = ACPI_STATE_UNKNOWN;
 569         return 0;
 570 }
 571
 572 static acpi_status
 573 acpi_bus_extract_wakeup_device_power_package(struct acpi_device *device,
 574                                              union acpi_object *package)
 575 {
 576         int i = 0;
 577         union acpi_object *element = NULL;
 578
 579         if (!device || !package || (package->package.count < 2))
 580                 return AE_BAD_PARAMETER;
 581
 582         element = &(package->package.elements[0]);
 583         if (!element)
 584                 return AE_BAD_PARAMETER;
 585         if (element->type == ACPI_TYPE_PACKAGE) {
 586                 if ((element->package.count < 2) ||
 587                     (element->package.elements[0].type !=
 588                      ACPI_TYPE_LOCAL_REFERENCE)
 589                     || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
 590                         return AE_BAD_DATA;
 591                 device->wakeup.gpe_device =
 592                     element->package.elements[0].reference.handle;
 593                 device->wakeup.gpe_number =
 594                     (u32) element->package.elements[1].integer.value;
 595         } else if (element->type == ACPI_TYPE_INTEGER) {
 596                 device->wakeup.gpe_number = element->integer.value;
 597         } else
 598                 return AE_BAD_DATA;
 599
 600         element = &(package->package.elements[1]);
 601         if (element->type != ACPI_TYPE_INTEGER) {
 602                 return AE_BAD_DATA;
 603         }
 604         device->wakeup.sleep_state = element->integer.value;
 605
 606         if ((package->package.count - 2) > ACPI_MAX_HANDLES) {
 607                 return AE_NO_MEMORY;
 608         }
 609         device->wakeup.resources.count = package->package.count - 2;
 610         for (i = 0; i < device->wakeup.resources.count; i++) {
 611                 element = &(package->package.elements[i + 2]);
 612                 if (element->type != ACPI_TYPE_ANY) {
 613                         return AE_BAD_DATA;
 614                 }
 615
 616                 device->wakeup.resources.handles[i] = element->reference.handle;
 617         }
 618
 619         return AE_OK;
 620 }
 621
 622 static int acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
 623 {
 624         acpi_status status = 0;
 625         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 626         union acpi_object *package = NULL;
 627
 628
 629         /* _PRW */
 630         status = acpi_evaluate_object(device->handle, "_PRW", NULL, &buffer);
 631         if (ACPI_FAILURE(status)) {
 632                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
 633                 goto end;
 634         }
 635
 636         package = (union acpi_object *)buffer.pointer;
 637         status = acpi_bus_extract_wakeup_device_power_package(device, package);
 638         if (ACPI_FAILURE(status)) {
 639                 ACPI_EXCEPTION((AE_INFO, status, "Extracting _PRW package"));
 640                 goto end;
 641         }
 642
 643         kfree(buffer.pointer);
 644
 645         device->wakeup.flags.valid = 1;
 646         /* Power button, Lid switch always enable wakeup */
 647         if (!acpi_match_ids(device, "PNP0C0D,PNP0C0C,PNP0C0E"))
 648                 device->wakeup.flags.run_wake = 1;
 649
 650       end:
 651         if (ACPI_FAILURE(status))
 652                 device->flags.wake_capable = 0;
 653         return 0;
 654 }
 655
 656 static int acpi_bus_get_power_flags(struct acpi_device *device)
 657 {
 658         acpi_status status = 0;
 659         acpi_handle handle = NULL;
 660         u32 i = 0;
 661
 662
 663         /*
 664          * Power Management Flags
 665          */
 666         status = acpi_get_handle(device->handle, "_PSC", &handle);
 667         if (ACPI_SUCCESS(status))
 668                 device->power.flags.explicit_get = 1;
 669         status = acpi_get_handle(device->handle, "_IRC", &handle);
 670         if (ACPI_SUCCESS(status))
 671                 device->power.flags.inrush_current = 1;
 672
 673         /*
 674          * Enumerate supported power management states
 675          */
 676         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3; i++) {
 677                 struct acpi_device_power_state *ps = &device->power.states[i];
 678                 char object_name[5] = { '_', 'P', 'R', '0' + i, '\0' };
 679
 680                 /* Evaluate "_PRx" to se if power resources are referenced */
 681                 acpi_evaluate_reference(device->handle, object_name, NULL,
 682                                         &ps->resources);
 683                 if (ps->resources.count) {
 684                         device->power.flags.power_resources = 1;
 685                         ps->flags.valid = 1;
 686                 }
 687
 688                 /* Evaluate "_PSx" to see if we can do explicit sets */
 689                 object_name[2] = 'S';
 690                 status = acpi_get_handle(device->handle, object_name, &handle);
 691                 if (ACPI_SUCCESS(status)) {
 692                         ps->flags.explicit_set = 1;
 693                         ps->flags.valid = 1;
 694                 }
 695
 696                 /* State is valid if we have some power control */
 697                 if (ps->resources.count || ps->flags.explicit_set)
 698                         ps->flags.valid = 1;
 699
 700                 ps->power = -1; /* Unknown - driver assigned */
 701                 ps->latency = -1;       /* Unknown - driver assigned */
 702         }
 703
 704         /* Set defaults for D0 and D3 states (always valid) */
 705         device->power.states[ACPI_STATE_D0].flags.valid = 1;
 706         device->power.states[ACPI_STATE_D0].power = 100;
 707         device->power.states[ACPI_STATE_D3].flags.valid = 1;
 708         device->power.states[ACPI_STATE_D3].power = 0;
 709
 710         /* TBD: System wake support and resource requirements. */
 711
 712         device->power.state = ACPI_STATE_UNKNOWN;
 713
 714         return 0;
 715 }
 716
 717 static int acpi_bus_get_flags(struct acpi_device *device)
 718 {
 719         acpi_status status = AE_OK;
 720         acpi_handle temp = NULL;
 721
 722
 723         /* Presence of _STA indicates 'dynamic_status' */
 724         status = acpi_get_handle(device->handle, "_STA", &temp);
 725         if (ACPI_SUCCESS(status))
 726                 device->flags.dynamic_status = 1;
 727
 728         /* Presence of _CID indicates 'compatible_ids' */
 729         status = acpi_get_handle(device->handle, "_CID", &temp);
 730         if (ACPI_SUCCESS(status))
 731                 device->flags.compatible_ids = 1;
 732
 733         /* Presence of _RMV indicates 'removable' */
 734         status = acpi_get_handle(device->handle, "_RMV", &temp);
 735         if (ACPI_SUCCESS(status))
 736                 device->flags.removable = 1;
 737
 738         /* Presence of _EJD|_EJ0 indicates 'ejectable' */
 739         status = acpi_get_handle(device->handle, "_EJD", &temp);
 740         if (ACPI_SUCCESS(status))
 741                 device->flags.ejectable = 1;
 742         else {
 743                 status = acpi_get_handle(device->handle, "_EJ0", &temp);
 744                 if (ACPI_SUCCESS(status))
 745                         device->flags.ejectable = 1;
 746         }
 747
 748         /* Presence of _LCK indicates 'lockable' */
 749         status = acpi_get_handle(device->handle, "_LCK", &temp);
 750         if (ACPI_SUCCESS(status))
 751                 device->flags.lockable = 1;
 752
 753         /* Presence of _PS0|_PR0 indicates 'power manageable' */
 754         status = acpi_get_handle(device->handle, "_PS0", &temp);
 755         if (ACPI_FAILURE(status))
 756                 status = acpi_get_handle(device->handle, "_PR0", &temp);
 757         if (ACPI_SUCCESS(status))
 758                 device->flags.power_manageable = 1;
 759
 760         /* Presence of _PRW indicates wake capable */
 761         status = acpi_get_handle(device->handle, "_PRW", &temp);
 762         if (ACPI_SUCCESS(status))
 763                 device->flags.wake_capable = 1;
 764
 765         /* TBD: Peformance management */
 766
 767         return 0;
 768 }
 769
 770 static void acpi_device_get_busid(struct acpi_device *device,
 771                                   acpi_handle handle, int type)
 772 {
 773         char bus_id[5] = { '?', 0 };
 774         struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
 775         int i = 0;
 776
 777         /*
 778          * Bus ID
 779          * ------
 780          * The device's Bus ID is simply the object name.
 781          * TBD: Shouldn't this value be unique (within the ACPI namespace)?
 782          */
 783         switch (type) {
 784         case ACPI_BUS_TYPE_SYSTEM:
 785                 strcpy(device->pnp.bus_id, "ACPI");
 786                 break;
 787         case ACPI_BUS_TYPE_POWER_BUTTON:
 788                 strcpy(device->pnp.bus_id, "PWRF");
 789                 break;
 790         case ACPI_BUS_TYPE_SLEEP_BUTTON:
 791                 strcpy(device->pnp.bus_id, "SLPF");
 792                 break;
 793         default:
 794                 acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 795                 /* Clean up trailing underscores (if any) */
 796                 for (i = 3; i > 1; i--) {
 797                         if (bus_id[i] == '_')
 798                                 bus_id[i] = '\0';
 799                         else
 800                                 break;
 801                 }
 802                 strcpy(device->pnp.bus_id, bus_id);
 803                 break;
 804         }
 805 }
 806
 807 static int
 808 acpi_video_bus_match(struct acpi_device *device)
 809 {
 810         acpi_handle h_dummy1;
 811         acpi_handle h_dummy2;
 812         acpi_handle h_dummy3;
 813
 814
 815         if (!device)
 816                 return -EINVAL;
 817
 818         /* Since there is no HID, CID for ACPI Video drivers, we have
 819          * to check well known required nodes for each feature we support.
 820          */
 821
 822         /* Does this device able to support video switching ? */
 823         if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOD", &h_dummy1)) &&
 824             ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOS", &h_dummy2)))
 825                 return 0;
 826
 827         /* Does this device able to retrieve a video ROM ? */
 828         if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_ROM", &h_dummy1)))
 829                 return 0;
 830
 831         /* Does this device able to configure which video head to be POSTed ? */
 832         if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_VPO", &h_dummy1)) &&
 833             ACPI_SUCCESS(acpi_get_handle(device->handle, "_GPD", &h_dummy2)) &&
 834             ACPI_SUCCESS(acpi_get_handle(device->handle, "_SPD", &h_dummy3)))
 835                 return 0;
 836
 837         return -ENODEV;
 838 }
 839
 840 /*
 841  * acpi_bay_match - see if a device is an ejectable driver bay
 842  *
 843  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
 844  * then we can safely call it an ejectable drive bay
 845  */
 846 static int acpi_bay_match(struct acpi_device *device){
 847         acpi_status status;
 848         acpi_handle handle;
 849         acpi_handle tmp;
 850         acpi_handle phandle;
 851
 852         handle = device->handle;
 853
 854         status = acpi_get_handle(handle, "_EJ0", &tmp);
 855         if (ACPI_FAILURE(status))
 856                 return -ENODEV;
 857
 858         if ((ACPI_SUCCESS(acpi_get_handle(handle, "_GTF", &tmp))) ||
 859                 (ACPI_SUCCESS(acpi_get_handle(handle, "_GTM", &tmp))) ||
 860                 (ACPI_SUCCESS(acpi_get_handle(handle, "_STM", &tmp))) ||
 861                 (ACPI_SUCCESS(acpi_get_handle(handle, "_SDD", &tmp))))
 862                 return 0;
 863
 864         if (acpi_get_parent(handle, &phandle))
 865                 return -ENODEV;
 866
 867         if ((ACPI_SUCCESS(acpi_get_handle(phandle, "_GTF", &tmp))) ||
 868                 (ACPI_SUCCESS(acpi_get_handle(phandle, "_GTM", &tmp))) ||
 869                 (ACPI_SUCCESS(acpi_get_handle(phandle, "_STM", &tmp))) ||
 870                 (ACPI_SUCCESS(acpi_get_handle(phandle, "_SDD", &tmp))))
 871                 return 0;
 872
 873         return -ENODEV;
 874 }
 875
 876 static void acpi_device_set_id(struct acpi_device *device,
 877                                struct acpi_device *parent, acpi_handle handle,
 878                                int type)
 879 {
 880         struct acpi_device_info *info;
 881         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 882         char *hid = NULL;
 883         char *uid = NULL;
 884         struct acpi_compatible_id_list *cid_list = NULL;
 885         acpi_status status;
 886
 887         switch (type) {
 888         case ACPI_BUS_TYPE_DEVICE:
 889                 status = acpi_get_object_info(handle, &buffer);
 890                 if (ACPI_FAILURE(status)) {
 891                         printk("%s: Error reading device info\n", __FUNCTION__);
 892                         return;
 893                 }
 894
 895                 info = buffer.pointer;
 896                 if (info->valid & ACPI_VALID_HID)
 897                         hid = info->hardware_id.value;
 898                 if (info->valid & ACPI_VALID_UID)
 899                         uid = info->unique_id.value;
 900                 if (info->valid & ACPI_VALID_CID)
 901                         cid_list = &info->compatibility_id;
 902                 if (info->valid & ACPI_VALID_ADR) {
 903                         device->pnp.bus_address = info->address;
 904                         device->flags.bus_address = 1;
 905                 }
 906
 907                 if(!(info->valid & (ACPI_VALID_HID | ACPI_VALID_CID))){
 908                         status = acpi_video_bus_match(device);
 909                         if(ACPI_SUCCESS(status))
 910                                 hid = ACPI_VIDEO_HID;
 911
 912                         status = acpi_bay_match(device);
 913                         if (ACPI_SUCCESS(status))
 914                                 hid = ACPI_BAY_HID;
 915                 }
 916                 break;
 917         case ACPI_BUS_TYPE_POWER:
 918                 hid = ACPI_POWER_HID;
 919                 break;
 920         case ACPI_BUS_TYPE_PROCESSOR:
 921                 hid = ACPI_PROCESSOR_HID;
 922                 break;
 923         case ACPI_BUS_TYPE_SYSTEM:
 924                 hid = ACPI_SYSTEM_HID;
 925                 break;
 926         case ACPI_BUS_TYPE_THERMAL:
 927                 hid = ACPI_THERMAL_HID;
 928                 break;
 929         case ACPI_BUS_TYPE_POWER_BUTTON:
 930                 hid = ACPI_BUTTON_HID_POWERF;
 931                 break;
 932         case ACPI_BUS_TYPE_SLEEP_BUTTON:
 933                 hid = ACPI_BUTTON_HID_SLEEPF;
 934                 break;
 935         }
 936
 937         /*
 938          * \_SB
 939          * ----
 940          * Fix for the system root bus device -- the only root-level device.
 941          */
 942         if (((acpi_handle)parent == ACPI_ROOT_OBJECT) && (type == ACPI_BUS_TYPE_DEVICE)) {
 943                 hid = ACPI_BUS_HID;
 944                 strcpy(device->pnp.device_name, ACPI_BUS_DEVICE_NAME);
 945                 strcpy(device->pnp.device_class, ACPI_BUS_CLASS);
 946         }
 947
 948         if (hid) {
 949                 strcpy(device->pnp.hardware_id, hid);
 950                 device->flags.hardware_id = 1;
 951         }
 952         if (uid) {
 953                 strcpy(device->pnp.unique_id, uid);
 954                 device->flags.unique_id = 1;
 955         }
 956         if (cid_list) {
 957                 device->pnp.cid_list = kmalloc(cid_list->size, GFP_KERNEL);
 958                 if (device->pnp.cid_list)
 959                         memcpy(device->pnp.cid_list, cid_list, cid_list->size);
 960                 else
 961                         printk(KERN_ERR "Memory allocation error\n");
 962         }
 963
 964         kfree(buffer.pointer);
 965 }
 966
 967 static int acpi_device_set_context(struct acpi_device *device, int type)
 968 {
 969         acpi_status status = AE_OK;
 970         int result = 0;
 971         /*
 972          * Context
 973          * -------
 974          * Attach this 'struct acpi_device' to the ACPI object.  This makes
 975          * resolutions from handle->device very efficient.  Note that we need
 976          * to be careful with fixed-feature devices as they all attach to the
 977          * root object.
 978          */
 979         if (type != ACPI_BUS_TYPE_POWER_BUTTON &&
 980             type != ACPI_BUS_TYPE_SLEEP_BUTTON) {
 981                 status = acpi_attach_data(device->handle,
 982                                           acpi_bus_data_handler, device);
 983
 984                 if (ACPI_FAILURE(status)) {
 985                         printk("Error attaching device data\n");
 986                         result = -ENODEV;
 987                 }
 988         }
 989         return result;
 990 }
 991
 992 static void acpi_device_get_debug_info(struct acpi_device *device,
 993                                        acpi_handle handle, int type)
 994 {
 995 #ifdef CONFIG_ACPI_DEBUG_OUTPUT
 996         char *type_string = NULL;
 997         char name[80] = { '?', '\0' };
 998         struct acpi_buffer buffer = { sizeof(name), name };
 999
1000         switch (type) {
1001         case ACPI_BUS_TYPE_DEVICE:
1002                 type_string = "Device";
1003                 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
1004                 break;
1005         case ACPI_BUS_TYPE_POWER:
1006                 type_string = "Power Resource";
1007                 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
1008                 break;
1009         case ACPI_BUS_TYPE_PROCESSOR:
1010                 type_string = "Processor";
1011                 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
1012                 break;
1013         case ACPI_BUS_TYPE_SYSTEM:
1014                 type_string = "System";
1015                 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
1016                 break;
1017         case ACPI_BUS_TYPE_THERMAL:
1018                 type_string = "Thermal Zone";
1019                 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
1020                 break;
1021         case ACPI_BUS_TYPE_POWER_BUTTON:
1022                 type_string = "Power Button";
1023                 sprintf(name, "PWRB");
1024                 break;
1025         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1026                 type_string = "Sleep Button";
1027                 sprintf(name, "SLPB");
1028                 break;
1029         }
1030
1031         printk(KERN_DEBUG "Found %s %s [%p]\n", type_string, name, handle);
1032 #endif                          /*CONFIG_ACPI_DEBUG_OUTPUT */
1033 }
1034
1035 static int acpi_bus_remove(struct acpi_device *dev, int rmdevice)
1036 {
1037         if (!dev)
1038                 return -EINVAL;
1039
1040         dev->removal_type = ACPI_BUS_REMOVAL_EJECT;
1041         device_release_driver(&dev->dev);
1042
1043         if (!rmdevice)
1044                 return 0;
1045
1046         /*
1047          * unbind _ADR-Based Devices when hot removal
1048          */
1049         if (dev->flags.bus_address) {
1050                 if ((dev->parent) && (dev->parent->ops.unbind))
1051                         dev->parent->ops.unbind(dev);
1052         }
1053         acpi_device_unregister(dev, ACPI_BUS_REMOVAL_EJECT);
1054
1055         return 0;
1056 }
1057
1058 static int
1059 acpi_add_single_object(struct acpi_device **child,
1060                        struct acpi_device *parent, acpi_handle handle, int type,
1061                         struct acpi_bus_ops *ops)
1062 {
1063         int result = 0;
1064         struct acpi_device *device = NULL;
1065
1066
1067         if (!child)
1068                 return -EINVAL;
1069
1070         device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1071         if (!device) {
1072                 printk(KERN_ERR PREFIX "Memory allocation error\n");
1073                 return -ENOMEM;
1074         }
1075
1076         device->handle = handle;
1077         device->parent = parent;
1078         device->bus_ops = *ops; /* workround for not call .start */
1079
1080
1081         acpi_device_get_busid(device, handle, type);
1082
1083         /*
1084          * Flags
1085          * -----
1086          * Get prior to calling acpi_bus_get_status() so we know whether
1087          * or not _STA is present.  Note that we only look for object
1088          * handles -- cannot evaluate objects until we know the device is
1089          * present and properly initialized.
1090          */
1091         result = acpi_bus_get_flags(device);
1092         if (result)
1093                 goto end;
1094
1095         /*
1096          * Status
1097          * ------
1098          * See if the device is present.  We always assume that non-Device
1099          * and non-Processor objects (e.g. thermal zones, power resources,
1100          * etc.) are present, functioning, etc. (at least when parent object
1101          * is present).  Note that _STA has a different meaning for some
1102          * objects (e.g. power resources) so we need to be careful how we use
1103          * it.
1104          */
1105         switch (type) {
1106         case ACPI_BUS_TYPE_PROCESSOR:
1107         case ACPI_BUS_TYPE_DEVICE:
1108                 result = acpi_bus_get_status(device);
1109                 if (ACPI_FAILURE(result) || !device->status.present) {
1110                         result = -ENOENT;
1111                         goto end;
1112                 }
1113                 break;
1114         default:
1115                 STRUCT_TO_INT(device->status) = 0x0F;
1116                 break;
1117         }
1118
1119         /*
1120          * Initialize Device
1121          * -----------------
1122          * TBD: Synch with Core's enumeration/initialization process.
1123          */
1124
1125         /*
1126          * Hardware ID, Unique ID, & Bus Address
1127          * -------------------------------------
1128          */
1129         acpi_device_set_id(device, parent, handle, type);
1130
1131         /*
1132          * Power Management
1133          * ----------------
1134          */
1135         if (device->flags.power_manageable) {
1136                 result = acpi_bus_get_power_flags(device);
1137                 if (result)
1138                         goto end;
1139         }
1140
1141         /*
1142          * Wakeup device management
1143          *-----------------------
1144          */
1145         if (device->flags.wake_capable) {
1146                 result = acpi_bus_get_wakeup_device_flags(device);
1147                 if (result)
1148                         goto end;
1149         }
1150
1151         /*
1152          * Performance Management
1153          * ----------------------
1154          */
1155         if (device->flags.performance_manageable) {
1156                 result = acpi_bus_get_perf_flags(device);
1157                 if (result)
1158                         goto end;
1159         }
1160
1161         if ((result = acpi_device_set_context(device, type)))
1162                 goto end;
1163
1164         acpi_device_get_debug_info(device, handle, type);
1165
1166         result = acpi_device_register(device, parent);
1167
1168         /*
1169          * Bind _ADR-Based Devices when hot add
1170          */
1171         if (device->flags.bus_address) {
1172                 if (device->parent && device->parent->ops.bind)
1173                         device->parent->ops.bind(device);
1174         }
1175
1176       end:
1177         if (!result)
1178                 *child = device;
1179         else {
1180                 kfree(device->pnp.cid_list);
1181                 kfree(device);
1182         }
1183
1184         return result;
1185 }
1186
1187 static int acpi_bus_scan(struct acpi_device *start, struct acpi_bus_ops *ops)
1188 {
1189         acpi_status status = AE_OK;
1190         struct acpi_device *parent = NULL;
1191         struct acpi_device *child = NULL;
1192         acpi_handle phandle = NULL;
1193         acpi_handle chandle = NULL;
1194         acpi_object_type type = 0;
1195         u32 level = 1;
1196
1197
1198         if (!start)
1199                 return -EINVAL;
1200
1201         parent = start;
1202         phandle = start->handle;
1203
1204         /*
1205          * Parse through the ACPI namespace, identify all 'devices', and
1206          * create a new 'struct acpi_device' for each.
1207          */
1208         while ((level > 0) && parent) {
1209
1210                 status = acpi_get_next_object(ACPI_TYPE_ANY, phandle,
1211                                               chandle, &chandle);
1212
1213                 /*
1214                  * If this scope is exhausted then move our way back up.
1215                  */
1216                 if (ACPI_FAILURE(status)) {
1217                         level--;
1218                         chandle = phandle;
1219                         acpi_get_parent(phandle, &phandle);
1220                         if (parent->parent)
1221                                 parent = parent->parent;
1222                         continue;
1223                 }
1224
1225                 status = acpi_get_type(chandle, &type);
1226                 if (ACPI_FAILURE(status))
1227                         continue;
1228
1229                 /*
1230                  * If this is a scope object then parse it (depth-first).
1231                  */
1232                 if (type == ACPI_TYPE_LOCAL_SCOPE) {
1233                         level++;
1234                         phandle = chandle;
1235                         chandle = NULL;
1236                         continue;
1237                 }
1238
1239                 /*
1240                  * We're only interested in objects that we consider 'devices'.
1241                  */
1242                 switch (type) {
1243                 case ACPI_TYPE_DEVICE:
1244                         type = ACPI_BUS_TYPE_DEVICE;
1245                         break;
1246                 case ACPI_TYPE_PROCESSOR:
1247                         type = ACPI_BUS_TYPE_PROCESSOR;
1248                         break;
1249                 case ACPI_TYPE_THERMAL:
1250                         type = ACPI_BUS_TYPE_THERMAL;
1251                         break;
1252                 case ACPI_TYPE_POWER:
1253                         type = ACPI_BUS_TYPE_POWER;
1254                         break;
1255                 default:
1256                         continue;
1257                 }
1258
1259                 if (ops->acpi_op_add)
1260                         status = acpi_add_single_object(&child, parent,
1261                                 chandle, type, ops);
1262                 else
1263                         status = acpi_bus_get_device(chandle, &child);
1264
1265                 if (ACPI_FAILURE(status))
1266                         continue;
1267
1268                 if (ops->acpi_op_start && !(ops->acpi_op_add)) {
1269                         status = acpi_start_single_object(child);
1270                         if (ACPI_FAILURE(status))
1271                                 continue;
1272                 }
1273
1274                 /*
1275                  * If the device is present, enabled, and functioning then
1276                  * parse its scope (depth-first).  Note that we need to
1277                  * represent absent devices to facilitate PnP notifications
1278                  * -- but only the subtree head (not all of its children,
1279                  * which will be enumerated when the parent is inserted).
1280                  *
1281                  * TBD: Need notifications and other detection mechanisms
1282                  *      in place before we can fully implement this.
1283                  */
1284                 if (child->status.present) {
1285                         status = acpi_get_next_object(ACPI_TYPE_ANY, chandle,
1286                                                       NULL, NULL);
1287                         if (ACPI_SUCCESS(status)) {
1288                                 level++;
1289                                 phandle = chandle;
1290                                 chandle = NULL;
1291                                 parent = child;
1292                         }
1293                 }
1294         }
1295
1296         return 0;
1297 }
1298
1299 int
1300 acpi_bus_add(struct acpi_device **child,
1301              struct acpi_device *parent, acpi_handle handle, int type)
1302 {
1303         int result;
1304         struct acpi_bus_ops ops;
1305
1306         memset(&ops, 0, sizeof(ops));
1307         ops.acpi_op_add = 1;
1308
1309         result = acpi_add_single_object(child, parent, handle, type, &ops);
1310         if (!result)
1311                 result = acpi_bus_scan(*child, &ops);
1312
1313         return result;
1314 }
1315
1316 EXPORT_SYMBOL(acpi_bus_add);
1317
1318 int acpi_bus_start(struct acpi_device *device)
1319 {
1320         int result;
1321         struct acpi_bus_ops ops;
1322
1323
1324         if (!device)
1325                 return -EINVAL;
1326
1327         result = acpi_start_single_object(device);
1328         if (!result) {
1329                 memset(&ops, 0, sizeof(ops));
1330                 ops.acpi_op_start = 1;
1331                 result = acpi_bus_scan(device, &ops);
1332         }
1333         return result;
1334 }
1335
1336 EXPORT_SYMBOL(acpi_bus_start);
1337
1338 int acpi_bus_trim(struct acpi_device *start, int rmdevice)
1339 {
1340         acpi_status status;
1341         struct acpi_device *parent, *child;
1342         acpi_handle phandle, chandle;
1343         acpi_object_type type;
1344         u32 level = 1;
1345         int err = 0;
1346
1347         parent = start;
1348         phandle = start->handle;
1349         child = chandle = NULL;
1350
1351         while ((level > 0) && parent && (!err)) {
1352                 status = acpi_get_next_object(ACPI_TYPE_ANY, phandle,
1353                                               chandle, &chandle);
1354
1355                 /*
1356                  * If this scope is exhausted then move our way back up.
1357                  */
1358                 if (ACPI_FAILURE(status)) {
1359                         level--;
1360                         chandle = phandle;
1361                         acpi_get_parent(phandle, &phandle);
1362                         child = parent;
1363                         parent = parent->parent;
1364
1365                         if (level == 0)
1366                                 err = acpi_bus_remove(child, rmdevice);
1367                         else
1368                                 err = acpi_bus_remove(child, 1);
1369
1370                         continue;
1371                 }
1372
1373                 status = acpi_get_type(chandle, &type);
1374                 if (ACPI_FAILURE(status)) {
1375                         continue;
1376                 }
1377                 /*
1378                  * If there is a device corresponding to chandle then
1379                  * parse it (depth-first).
1380                  */
1381                 if (acpi_bus_get_device(chandle, &child) == 0) {
1382                         level++;
1383                         phandle = chandle;
1384                         chandle = NULL;
1385                         parent = child;
1386                 }
1387                 continue;
1388         }
1389         return err;
1390 }
1391 EXPORT_SYMBOL_GPL(acpi_bus_trim);
1392
1393
1394 static int acpi_bus_scan_fixed(struct acpi_device *root)
1395 {
1396         int result = 0;
1397         struct acpi_device *device = NULL;
1398         struct acpi_bus_ops ops;
1399
1400         if (!root)
1401                 return -ENODEV;
1402
1403         memset(&ops, 0, sizeof(ops));
1404         ops.acpi_op_add = 1;
1405         ops.acpi_op_start = 1;
1406
1407         /*
1408          * Enumerate all fixed-feature devices.
1409          */
1410         if ((acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON) == 0) {
1411                 result = acpi_add_single_object(&device, acpi_root,
1412                                                 NULL,
1413                                                 ACPI_BUS_TYPE_POWER_BUTTON,
1414                                                 &ops);
1415         }
1416
1417         if ((acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON) == 0) {
1418                 result = acpi_add_single_object(&device, acpi_root,
1419                                                 NULL,
1420                                                 ACPI_BUS_TYPE_SLEEP_BUTTON,
1421                                                 &ops);
1422         }
1423
1424         return result;
1425 }
1426
1427 static int __init acpi_scan_init(void)
1428 {
1429         int result;
1430         struct acpi_bus_ops ops;
1431
1432
1433         if (acpi_disabled)
1434                 return 0;
1435
1436         memset(&ops, 0, sizeof(ops));
1437         ops.acpi_op_add = 1;
1438         ops.acpi_op_start = 1;
1439
1440         result = bus_register(&acpi_bus_type);
1441         if (result) {
1442                 /* We don't want to quit even if we failed to add suspend/resume */
1443                 printk(KERN_ERR PREFIX "Could not register bus type\n");
1444         }
1445
1446         /*
1447          * Create the root device in the bus's device tree
1448          */
1449         result = acpi_add_single_object(&acpi_root, NULL, ACPI_ROOT_OBJECT,
1450                                         ACPI_BUS_TYPE_SYSTEM, &ops);
1451         if (result)
1452                 goto Done;
1453
1454         /*
1455          * Enumerate devices in the ACPI namespace.
1456          */
1457         result = acpi_bus_scan_fixed(acpi_root);
1458         if (!result)
1459                 result = acpi_bus_scan(acpi_root, &ops);
1460
1461         if (result)
1462                 acpi_device_unregister(acpi_root, ACPI_BUS_REMOVAL_NORMAL);
1463
1464       Done:
1465         return result;
1466 }
1467
1468 subsys_initcall(acpi_scan_init);