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 #include <linux/signal.h>
  10 #include <linux/kthread.h>
  11
  12 #include <acpi/acpi_drivers.h>
  13
  14 #include "internal.h"
  15
  16 #define _COMPONENT              ACPI_BUS_COMPONENT
  17 ACPI_MODULE_NAME("scan");
  18 #define STRUCT_TO_INT(s)        (*((int*)&s))
  19 extern struct acpi_device *acpi_root;
  20
  21 #define ACPI_BUS_CLASS                  "system_bus"
  22 #define ACPI_BUS_HID                    "LNXSYBUS"
  23 #define ACPI_BUS_DEVICE_NAME            "System Bus"
  24
  25 #define ACPI_IS_ROOT_DEVICE(device)    (!(device)->parent)
  26
  27 static LIST_HEAD(acpi_device_list);
  28 static LIST_HEAD(acpi_bus_id_list);
  29 DEFINE_MUTEX(acpi_device_lock);
  30 LIST_HEAD(acpi_wakeup_device_list);
  31
  32 struct acpi_device_bus_id{
  33         char bus_id[15];
  34         unsigned int instance_no;
  35         struct list_head node;
  36 };
  37
  38 /*
  39  * Creates hid/cid(s) string needed for modalias and uevent
  40  * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
  41  * char *modalias: "acpi:IBM0001:ACPI0001"
  42 */
  43 static int create_modalias(struct acpi_device *acpi_dev, char *modalias,
  44                            int size)
  45 {
  46         int len;
  47         int count;
  48         struct acpi_hardware_id *id;
  49
  50         len = snprintf(modalias, size, "acpi:");
  51         size -= len;
  52
  53         list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
  54                 count = snprintf(&modalias[len], size, "%s:", id->id);
  55                 if (count < 0 || count >= size)
  56                         return -EINVAL;
  57                 len += count;
  58                 size -= count;
  59         }
  60
  61         modalias[len] = '\0';
  62         return len;
  63 }
  64
  65 static ssize_t
  66 acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
  67         struct acpi_device *acpi_dev = to_acpi_device(dev);
  68         int len;
  69
  70         /* Device has no HID and no CID or string is >1024 */
  71         len = create_modalias(acpi_dev, buf, 1024);
  72         if (len <= 0)
  73                 return 0;
  74         buf[len++] = '\n';
  75         return len;
  76 }
  77 static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
  78
  79 static void acpi_bus_hot_remove_device(void *context)
  80 {
  81         struct acpi_device *device;
  82         acpi_handle handle = context;
  83         struct acpi_object_list arg_list;
  84         union acpi_object arg;
  85         acpi_status status = AE_OK;
  86
  87         if (acpi_bus_get_device(handle, &device))
  88                 return;
  89
  90         if (!device)
  91                 return;
  92
  93         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
  94                 "Hot-removing device %s...\n", dev_name(&device->dev)));
  95
  96         if (acpi_bus_trim(device, 1)) {
  97                 printk(KERN_ERR PREFIX
  98                                 "Removing device failed\n");
  99                 return;
 100         }
 101
 102         /* power off device */
 103         status = acpi_evaluate_object(handle, "_PS3", NULL, NULL);
 104         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND)
 105                 printk(KERN_WARNING PREFIX
 106                                 "Power-off device failed\n");
 107
 108         if (device->flags.lockable) {
 109                 arg_list.count = 1;
 110                 arg_list.pointer = &arg;
 111                 arg.type = ACPI_TYPE_INTEGER;
 112                 arg.integer.value = 0;
 113                 acpi_evaluate_object(handle, "_LCK", &arg_list, NULL);
 114         }
 115
 116         arg_list.count = 1;
 117         arg_list.pointer = &arg;
 118         arg.type = ACPI_TYPE_INTEGER;
 119         arg.integer.value = 1;
 120
 121         /*
 122          * TBD: _EJD support.
 123          */
 124         status = acpi_evaluate_object(handle, "_EJ0", &arg_list, NULL);
 125         if (ACPI_FAILURE(status))
 126                 printk(KERN_WARNING PREFIX
 127                                 "Eject device failed\n");
 128
 129         return;
 130 }
 131
 132 static ssize_t
 133 acpi_eject_store(struct device *d, struct device_attribute *attr,
 134                 const char *buf, size_t count)
 135 {
 136         int ret = count;
 137         acpi_status status;
 138         acpi_object_type type = 0;
 139         struct acpi_device *acpi_device = to_acpi_device(d);
 140
 141         if ((!count) || (buf[0] != '1')) {
 142                 return -EINVAL;
 143         }
 144 #ifndef FORCE_EJECT
 145         if (acpi_device->driver == NULL) {
 146                 ret = -ENODEV;
 147                 goto err;
 148         }
 149 #endif
 150         status = acpi_get_type(acpi_device->handle, &type);
 151         if (ACPI_FAILURE(status) || (!acpi_device->flags.ejectable)) {
 152                 ret = -ENODEV;
 153                 goto err;
 154         }
 155
 156         acpi_os_hotplug_execute(acpi_bus_hot_remove_device, acpi_device->handle);
 157 err:
 158         return ret;
 159 }
 160
 161 static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
 162
 163 static ssize_t
 164 acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
 165         struct acpi_device *acpi_dev = to_acpi_device(dev);
 166
 167         return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
 168 }
 169 static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
 170
 171 static ssize_t
 172 acpi_device_path_show(struct device *dev, struct device_attribute *attr, char *buf) {
 173         struct acpi_device *acpi_dev = to_acpi_device(dev);
 174         struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
 175         int result;
 176
 177         result = acpi_get_name(acpi_dev->handle, ACPI_FULL_PATHNAME, &path);
 178         if (result)
 179                 goto end;
 180
 181         result = sprintf(buf, "%s\n", (char*)path.pointer);
 182         kfree(path.pointer);
 183 end:
 184         return result;
 185 }
 186 static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
 187
 188 static int acpi_device_setup_files(struct acpi_device *dev)
 189 {
 190         acpi_status status;
 191         acpi_handle temp;
 192         int result = 0;
 193
 194         /*
 195          * Devices gotten from FADT don't have a "path" attribute
 196          */
 197         if (dev->handle) {
 198                 result = device_create_file(&dev->dev, &dev_attr_path);
 199                 if (result)
 200                         goto end;
 201         }
 202
 203         result = device_create_file(&dev->dev, &dev_attr_hid);
 204         if (result)
 205                 goto end;
 206
 207         result = device_create_file(&dev->dev, &dev_attr_modalias);
 208         if (result)
 209                 goto end;
 210
 211         /*
 212          * If device has _EJ0, 'eject' file is created that is used to trigger
 213          * hot-removal function from userland.
 214          */
 215         status = acpi_get_handle(dev->handle, "_EJ0", &temp);
 216         if (ACPI_SUCCESS(status))
 217                 result = device_create_file(&dev->dev, &dev_attr_eject);
 218 end:
 219         return result;
 220 }
 221
 222 static void acpi_device_remove_files(struct acpi_device *dev)
 223 {
 224         acpi_status status;
 225         acpi_handle temp;
 226
 227         /*
 228          * If device has _EJ0, 'eject' file is created that is used to trigger
 229          * hot-removal function from userland.
 230          */
 231         status = acpi_get_handle(dev->handle, "_EJ0", &temp);
 232         if (ACPI_SUCCESS(status))
 233                 device_remove_file(&dev->dev, &dev_attr_eject);
 234
 235         device_remove_file(&dev->dev, &dev_attr_modalias);
 236         device_remove_file(&dev->dev, &dev_attr_hid);
 237         if (dev->handle)
 238                 device_remove_file(&dev->dev, &dev_attr_path);
 239 }
 240 /* --------------------------------------------------------------------------
 241                         ACPI Bus operations
 242    -------------------------------------------------------------------------- */
 243
 244 int acpi_match_device_ids(struct acpi_device *device,
 245                           const struct acpi_device_id *ids)
 246 {
 247         const struct acpi_device_id *id;
 248         struct acpi_hardware_id *hwid;
 249
 250         /*
 251          * If the device is not present, it is unnecessary to load device
 252          * driver for it.
 253          */
 254         if (!device->status.present)
 255                 return -ENODEV;
 256
 257         for (id = ids; id->id[0]; id++)
 258                 list_for_each_entry(hwid, &device->pnp.ids, list)
 259                         if (!strcmp((char *) id->id, hwid->id))
 260                                 return 0;
 261
 262         return -ENOENT;
 263 }
 264 EXPORT_SYMBOL(acpi_match_device_ids);
 265
 266 static void acpi_free_ids(struct acpi_device *device)
 267 {
 268         struct acpi_hardware_id *id, *tmp;
 269
 270         list_for_each_entry_safe(id, tmp, &device->pnp.ids, list) {
 271                 kfree(id->id);
 272                 kfree(id);
 273         }
 274 }
 275
 276 static void acpi_device_release(struct device *dev)
 277 {
 278         struct acpi_device *acpi_dev = to_acpi_device(dev);
 279
 280         acpi_free_ids(acpi_dev);
 281         kfree(acpi_dev);
 282 }
 283
 284 static int acpi_device_suspend(struct device *dev, pm_message_t state)
 285 {
 286         struct acpi_device *acpi_dev = to_acpi_device(dev);
 287         struct acpi_driver *acpi_drv = acpi_dev->driver;
 288
 289         if (acpi_drv && acpi_drv->ops.suspend)
 290                 return acpi_drv->ops.suspend(acpi_dev, state);
 291         return 0;
 292 }
 293
 294 static int acpi_device_resume(struct device *dev)
 295 {
 296         struct acpi_device *acpi_dev = to_acpi_device(dev);
 297         struct acpi_driver *acpi_drv = acpi_dev->driver;
 298
 299         if (acpi_drv && acpi_drv->ops.resume)
 300                 return acpi_drv->ops.resume(acpi_dev);
 301         return 0;
 302 }
 303
 304 static int acpi_bus_match(struct device *dev, struct device_driver *drv)
 305 {
 306         struct acpi_device *acpi_dev = to_acpi_device(dev);
 307         struct acpi_driver *acpi_drv = to_acpi_driver(drv);
 308
 309         return !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
 310 }
 311
 312 static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 313 {
 314         struct acpi_device *acpi_dev = to_acpi_device(dev);
 315         int len;
 316
 317         if (add_uevent_var(env, "MODALIAS="))
 318                 return -ENOMEM;
 319         len = create_modalias(acpi_dev, &env->buf[env->buflen - 1],
 320                               sizeof(env->buf) - env->buflen);
 321         if (len >= (sizeof(env->buf) - env->buflen))
 322                 return -ENOMEM;
 323         env->buflen += len;
 324         return 0;
 325 }
 326
 327 static void acpi_device_notify(acpi_handle handle, u32 event, void *data)
 328 {
 329         struct acpi_device *device = data;
 330
 331         device->driver->ops.notify(device, event);
 332 }
 333
 334 static acpi_status acpi_device_notify_fixed(void *data)
 335 {
 336         struct acpi_device *device = data;
 337
 338         /* Fixed hardware devices have no handles */
 339         acpi_device_notify(NULL, ACPI_FIXED_HARDWARE_EVENT, device);
 340         return AE_OK;
 341 }
 342
 343 static int acpi_device_install_notify_handler(struct acpi_device *device)
 344 {
 345         acpi_status status;
 346
 347         if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
 348                 status =
 349                     acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
 350                                                      acpi_device_notify_fixed,
 351                                                      device);
 352         else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
 353                 status =
 354                     acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
 355                                                      acpi_device_notify_fixed,
 356                                                      device);
 357         else
 358                 status = acpi_install_notify_handler(device->handle,
 359                                                      ACPI_DEVICE_NOTIFY,
 360                                                      acpi_device_notify,
 361                                                      device);
 362
 363         if (ACPI_FAILURE(status))
 364                 return -EINVAL;
 365         return 0;
 366 }
 367
 368 static void acpi_device_remove_notify_handler(struct acpi_device *device)
 369 {
 370         if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
 371                 acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
 372                                                 acpi_device_notify_fixed);
 373         else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
 374                 acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
 375                                                 acpi_device_notify_fixed);
 376         else
 377                 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
 378                                            acpi_device_notify);
 379 }
 380
 381 static int acpi_bus_driver_init(struct acpi_device *, struct acpi_driver *);
 382 static int acpi_start_single_object(struct acpi_device *);
 383 static int acpi_device_probe(struct device * dev)
 384 {
 385         struct acpi_device *acpi_dev = to_acpi_device(dev);
 386         struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
 387         int ret;
 388
 389         ret = acpi_bus_driver_init(acpi_dev, acpi_drv);
 390         if (!ret) {
 391                 if (acpi_dev->bus_ops.acpi_op_start)
 392                         acpi_start_single_object(acpi_dev);
 393
 394                 if (acpi_drv->ops.notify) {
 395                         ret = acpi_device_install_notify_handler(acpi_dev);
 396                         if (ret) {
 397                                 if (acpi_drv->ops.remove)
 398                                         acpi_drv->ops.remove(acpi_dev,
 399                                                      acpi_dev->removal_type);
 400                                 return ret;
 401                         }
 402                 }
 403
 404                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 405                         "Found driver [%s] for device [%s]\n",
 406                         acpi_drv->name, acpi_dev->pnp.bus_id));
 407                 get_device(dev);
 408         }
 409         return ret;
 410 }
 411
 412 static int acpi_device_remove(struct device * dev)
 413 {
 414         struct acpi_device *acpi_dev = to_acpi_device(dev);
 415         struct acpi_driver *acpi_drv = acpi_dev->driver;
 416
 417         if (acpi_drv) {
 418                 if (acpi_drv->ops.notify)
 419                         acpi_device_remove_notify_handler(acpi_dev);
 420                 if (acpi_drv->ops.remove)
 421                         acpi_drv->ops.remove(acpi_dev, acpi_dev->removal_type);
 422         }
 423         acpi_dev->driver = NULL;
 424         acpi_dev->driver_data = NULL;
 425
 426         put_device(dev);
 427         return 0;
 428 }
 429
 430 struct bus_type acpi_bus_type = {
 431         .name           = "acpi",
 432         .suspend        = acpi_device_suspend,
 433         .resume         = acpi_device_resume,
 434         .match          = acpi_bus_match,
 435         .probe          = acpi_device_probe,
 436         .remove         = acpi_device_remove,
 437         .uevent         = acpi_device_uevent,
 438 };
 439
 440 static int acpi_device_register(struct acpi_device *device)
 441 {
 442         int result;
 443         struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
 444         int found = 0;
 445
 446         /*
 447          * Linkage
 448          * -------
 449          * Link this device to its parent and siblings.
 450          */
 451         INIT_LIST_HEAD(&device->children);
 452         INIT_LIST_HEAD(&device->node);
 453         INIT_LIST_HEAD(&device->wakeup_list);
 454
 455         new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
 456         if (!new_bus_id) {
 457                 printk(KERN_ERR PREFIX "Memory allocation error\n");
 458                 return -ENOMEM;
 459         }
 460
 461         mutex_lock(&acpi_device_lock);
 462         /*
 463          * Find suitable bus_id and instance number in acpi_bus_id_list
 464          * If failed, create one and link it into acpi_bus_id_list
 465          */
 466         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
 467                 if (!strcmp(acpi_device_bus_id->bus_id,
 468                             acpi_device_hid(device))) {
 469                         acpi_device_bus_id->instance_no++;
 470                         found = 1;
 471                         kfree(new_bus_id);
 472                         break;
 473                 }
 474         }
 475         if (!found) {
 476                 acpi_device_bus_id = new_bus_id;
 477                 strcpy(acpi_device_bus_id->bus_id, acpi_device_hid(device));
 478                 acpi_device_bus_id->instance_no = 0;
 479                 list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
 480         }
 481         dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
 482
 483         if (device->parent)
 484                 list_add_tail(&device->node, &device->parent->children);
 485
 486         if (device->wakeup.flags.valid)
 487                 list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
 488         mutex_unlock(&acpi_device_lock);
 489
 490         if (device->parent)
 491                 device->dev.parent = &device->parent->dev;
 492         device->dev.bus = &acpi_bus_type;
 493         device->dev.release = &acpi_device_release;
 494         result = device_register(&device->dev);
 495         if (result) {
 496                 dev_err(&device->dev, "Error registering device\n");
 497                 goto end;
 498         }
 499
 500         result = acpi_device_setup_files(device);
 501         if (result)
 502                 printk(KERN_ERR PREFIX "Error creating sysfs interface for device %s\n",
 503                        dev_name(&device->dev));
 504
 505         device->removal_type = ACPI_BUS_REMOVAL_NORMAL;
 506         return 0;
 507 end:
 508         mutex_lock(&acpi_device_lock);
 509         if (device->parent)
 510                 list_del(&device->node);
 511         list_del(&device->wakeup_list);
 512         mutex_unlock(&acpi_device_lock);
 513         return result;
 514 }
 515
 516 static void acpi_device_unregister(struct acpi_device *device, int type)
 517 {
 518         mutex_lock(&acpi_device_lock);
 519         if (device->parent)
 520                 list_del(&device->node);
 521
 522         list_del(&device->wakeup_list);
 523         mutex_unlock(&acpi_device_lock);
 524
 525         acpi_detach_data(device->handle, acpi_bus_data_handler);
 526
 527         acpi_device_remove_files(device);
 528         device_unregister(&device->dev);
 529 }
 530
 531 /* --------------------------------------------------------------------------
 532                                  Driver Management
 533    -------------------------------------------------------------------------- */
 534 /**
 535  * acpi_bus_driver_init - add a device to a driver
 536  * @device: the device to add and initialize
 537  * @driver: driver for the device
 538  *
 539  * Used to initialize a device via its device driver.  Called whenever a
 540  * driver is bound to a device.  Invokes the driver's add() ops.
 541  */
 542 static int
 543 acpi_bus_driver_init(struct acpi_device *device, struct acpi_driver *driver)
 544 {
 545         int result = 0;
 546
 547         if (!device || !driver)
 548                 return -EINVAL;
 549
 550         if (!driver->ops.add)
 551                 return -ENOSYS;
 552
 553         result = driver->ops.add(device);
 554         if (result) {
 555                 device->driver = NULL;
 556                 device->driver_data = NULL;
 557                 return result;
 558         }
 559
 560         device->driver = driver;
 561
 562         /*
 563          * TBD - Configuration Management: Assign resources to device based
 564          * upon possible configuration and currently allocated resources.
 565          */
 566
 567         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 568                           "Driver successfully bound to device\n"));
 569         return 0;
 570 }
 571
 572 static int acpi_start_single_object(struct acpi_device *device)
 573 {
 574         int result = 0;
 575         struct acpi_driver *driver;
 576
 577
 578         if (!(driver = device->driver))
 579                 return 0;
 580
 581         if (driver->ops.start) {
 582                 result = driver->ops.start(device);
 583                 if (result && driver->ops.remove)
 584                         driver->ops.remove(device, ACPI_BUS_REMOVAL_NORMAL);
 585         }
 586
 587         return result;
 588 }
 589
 590 /**
 591  * acpi_bus_register_driver - register a driver with the ACPI bus
 592  * @driver: driver being registered
 593  *
 594  * Registers a driver with the ACPI bus.  Searches the namespace for all
 595  * devices that match the driver's criteria and binds.  Returns zero for
 596  * success or a negative error status for failure.
 597  */
 598 int acpi_bus_register_driver(struct acpi_driver *driver)
 599 {
 600         int ret;
 601
 602         if (acpi_disabled)
 603                 return -ENODEV;
 604         driver->drv.name = driver->name;
 605         driver->drv.bus = &acpi_bus_type;
 606         driver->drv.owner = driver->owner;
 607
 608         ret = driver_register(&driver->drv);
 609         return ret;
 610 }
 611
 612 EXPORT_SYMBOL(acpi_bus_register_driver);
 613
 614 /**
 615  * acpi_bus_unregister_driver - unregisters a driver with the APIC bus
 616  * @driver: driver to unregister
 617  *
 618  * Unregisters a driver with the ACPI bus.  Searches the namespace for all
 619  * devices that match the driver's criteria and unbinds.
 620  */
 621 void acpi_bus_unregister_driver(struct acpi_driver *driver)
 622 {
 623         driver_unregister(&driver->drv);
 624 }
 625
 626 EXPORT_SYMBOL(acpi_bus_unregister_driver);
 627
 628 /* --------------------------------------------------------------------------
 629                                  Device Enumeration
 630    -------------------------------------------------------------------------- */
 631 static struct acpi_device *acpi_bus_get_parent(acpi_handle handle)
 632 {
 633         acpi_status status;
 634         int ret;
 635         struct acpi_device *device;
 636
 637         /*
 638          * Fixed hardware devices do not appear in the namespace and do not
 639          * have handles, but we fabricate acpi_devices for them, so we have
 640          * to deal with them specially.
 641          */
 642         if (handle == NULL)
 643                 return acpi_root;
 644
 645         do {
 646                 status = acpi_get_parent(handle, &handle);
 647                 if (status == AE_NULL_ENTRY)
 648                         return NULL;
 649                 if (ACPI_FAILURE(status))
 650                         return acpi_root;
 651
 652                 ret = acpi_bus_get_device(handle, &device);
 653                 if (ret == 0)
 654                         return device;
 655         } while (1);
 656 }
 657
 658 acpi_status
 659 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
 660 {
 661         acpi_status status;
 662         acpi_handle tmp;
 663         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 664         union acpi_object *obj;
 665
 666         status = acpi_get_handle(handle, "_EJD", &tmp);
 667         if (ACPI_FAILURE(status))
 668                 return status;
 669
 670         status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
 671         if (ACPI_SUCCESS(status)) {
 672                 obj = buffer.pointer;
 673                 status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
 674                                          ejd);
 675                 kfree(buffer.pointer);
 676         }
 677         return status;
 678 }
 679 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
 680
 681 void acpi_bus_data_handler(acpi_handle handle, void *context)
 682 {
 683
 684         /* TBD */
 685
 686         return;
 687 }
 688
 689 static int acpi_bus_get_perf_flags(struct acpi_device *device)
 690 {
 691         device->performance.state = ACPI_STATE_UNKNOWN;
 692         return 0;
 693 }
 694
 695 static acpi_status
 696 acpi_bus_extract_wakeup_device_power_package(struct acpi_device *device,
 697                                              union acpi_object *package)
 698 {
 699         int i = 0;
 700         union acpi_object *element = NULL;
 701
 702         if (!device || !package || (package->package.count < 2))
 703                 return AE_BAD_PARAMETER;
 704
 705         element = &(package->package.elements[0]);
 706         if (!element)
 707                 return AE_BAD_PARAMETER;
 708         if (element->type == ACPI_TYPE_PACKAGE) {
 709                 if ((element->package.count < 2) ||
 710                     (element->package.elements[0].type !=
 711                      ACPI_TYPE_LOCAL_REFERENCE)
 712                     || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
 713                         return AE_BAD_DATA;
 714                 device->wakeup.gpe_device =
 715                     element->package.elements[0].reference.handle;
 716                 device->wakeup.gpe_number =
 717                     (u32) element->package.elements[1].integer.value;
 718         } else if (element->type == ACPI_TYPE_INTEGER) {
 719                 device->wakeup.gpe_number = element->integer.value;
 720         } else
 721                 return AE_BAD_DATA;
 722
 723         element = &(package->package.elements[1]);
 724         if (element->type != ACPI_TYPE_INTEGER) {
 725                 return AE_BAD_DATA;
 726         }
 727         device->wakeup.sleep_state = element->integer.value;
 728
 729         if ((package->package.count - 2) > ACPI_MAX_HANDLES) {
 730                 return AE_NO_MEMORY;
 731         }
 732         device->wakeup.resources.count = package->package.count - 2;
 733         for (i = 0; i < device->wakeup.resources.count; i++) {
 734                 element = &(package->package.elements[i + 2]);
 735                 if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
 736                         return AE_BAD_DATA;
 737
 738                 device->wakeup.resources.handles[i] = element->reference.handle;
 739         }
 740
 741         return AE_OK;
 742 }
 743
 744 static void acpi_bus_set_run_wake_flags(struct acpi_device *device)
 745 {
 746         struct acpi_device_id button_device_ids[] = {
 747                 {"PNP0C0D", 0},
 748                 {"PNP0C0C", 0},
 749                 {"PNP0C0E", 0},
 750                 {"", 0},
 751         };
 752         acpi_status status;
 753         acpi_event_status event_status;
 754
 755         device->wakeup.run_wake_count = 0;
 756
 757         /* Power button, Lid switch always enable wakeup */
 758         if (!acpi_match_device_ids(device, button_device_ids)) {
 759                 device->wakeup.flags.run_wake = 1;
 760                 device->wakeup.flags.always_enabled = 1;
 761                 return;
 762         }
 763
 764         status = acpi_get_gpe_status(NULL, device->wakeup.gpe_number,
 765                                         ACPI_NOT_ISR, &event_status);
 766         if (status == AE_OK)
 767                 device->wakeup.flags.run_wake =
 768                                 !!(event_status & ACPI_EVENT_FLAG_HANDLE);
 769 }
 770
 771 static int acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
 772 {
 773         acpi_status status = 0;
 774         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 775         union acpi_object *package = NULL;
 776         int psw_error;
 777
 778         /* _PRW */
 779         status = acpi_evaluate_object(device->handle, "_PRW", NULL, &buffer);
 780         if (ACPI_FAILURE(status)) {
 781                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
 782                 goto end;
 783         }
 784
 785         package = (union acpi_object *)buffer.pointer;
 786         status = acpi_bus_extract_wakeup_device_power_package(device, package);
 787         if (ACPI_FAILURE(status)) {
 788                 ACPI_EXCEPTION((AE_INFO, status, "Extracting _PRW package"));
 789                 goto end;
 790         }
 791
 792         kfree(buffer.pointer);
 793
 794         device->wakeup.flags.valid = 1;
 795         device->wakeup.prepare_count = 0;
 796         acpi_bus_set_run_wake_flags(device);
 797         /* Call _PSW/_DSW object to disable its ability to wake the sleeping
 798          * system for the ACPI device with the _PRW object.
 799          * The _PSW object is depreciated in ACPI 3.0 and is replaced by _DSW.
 800          * So it is necessary to call _DSW object first. Only when it is not
 801          * present will the _PSW object used.
 802          */
 803         psw_error = acpi_device_sleep_wake(device, 0, 0, 0);
 804         if (psw_error)
 805                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 806                                 "error in _DSW or _PSW evaluation\n"));
 807
 808 end:
 809         if (ACPI_FAILURE(status))
 810                 device->flags.wake_capable = 0;
 811         return 0;
 812 }
 813
 814 static int acpi_bus_get_power_flags(struct acpi_device *device)
 815 {
 816         acpi_status status = 0;
 817         acpi_handle handle = NULL;
 818         u32 i = 0;
 819
 820
 821         /*
 822          * Power Management Flags
 823          */
 824         status = acpi_get_handle(device->handle, "_PSC", &handle);
 825         if (ACPI_SUCCESS(status))
 826                 device->power.flags.explicit_get = 1;
 827         status = acpi_get_handle(device->handle, "_IRC", &handle);
 828         if (ACPI_SUCCESS(status))
 829                 device->power.flags.inrush_current = 1;
 830
 831         /*
 832          * Enumerate supported power management states
 833          */
 834         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3; i++) {
 835                 struct acpi_device_power_state *ps = &device->power.states[i];
 836                 char object_name[5] = { '_', 'P', 'R', '0' + i, '\0' };
 837
 838                 /* Evaluate "_PRx" to se if power resources are referenced */
 839                 acpi_evaluate_reference(device->handle, object_name, NULL,
 840                                         &ps->resources);
 841                 if (ps->resources.count) {
 842                         device->power.flags.power_resources = 1;
 843                         ps->flags.valid = 1;
 844                 }
 845
 846                 /* Evaluate "_PSx" to see if we can do explicit sets */
 847                 object_name[2] = 'S';
 848                 status = acpi_get_handle(device->handle, object_name, &handle);
 849                 if (ACPI_SUCCESS(status)) {
 850                         ps->flags.explicit_set = 1;
 851                         ps->flags.valid = 1;
 852                 }
 853
 854                 /* State is valid if we have some power control */
 855                 if (ps->resources.count || ps->flags.explicit_set)
 856                         ps->flags.valid = 1;
 857
 858                 ps->power = -1; /* Unknown - driver assigned */
 859                 ps->latency = -1;       /* Unknown - driver assigned */
 860         }
 861
 862         /* Set defaults for D0 and D3 states (always valid) */
 863         device->power.states[ACPI_STATE_D0].flags.valid = 1;
 864         device->power.states[ACPI_STATE_D0].power = 100;
 865         device->power.states[ACPI_STATE_D3].flags.valid = 1;
 866         device->power.states[ACPI_STATE_D3].power = 0;
 867
 868         /* TBD: System wake support and resource requirements. */
 869
 870         device->power.state = ACPI_STATE_UNKNOWN;
 871         acpi_bus_get_power(device->handle, &(device->power.state));
 872
 873         return 0;
 874 }
 875
 876 static int acpi_bus_get_flags(struct acpi_device *device)
 877 {
 878         acpi_status status = AE_OK;
 879         acpi_handle temp = NULL;
 880
 881
 882         /* Presence of _STA indicates 'dynamic_status' */
 883         status = acpi_get_handle(device->handle, "_STA", &temp);
 884         if (ACPI_SUCCESS(status))
 885                 device->flags.dynamic_status = 1;
 886
 887         /* Presence of _RMV indicates 'removable' */
 888         status = acpi_get_handle(device->handle, "_RMV", &temp);
 889         if (ACPI_SUCCESS(status))
 890                 device->flags.removable = 1;
 891
 892         /* Presence of _EJD|_EJ0 indicates 'ejectable' */
 893         status = acpi_get_handle(device->handle, "_EJD", &temp);
 894         if (ACPI_SUCCESS(status))
 895                 device->flags.ejectable = 1;
 896         else {
 897                 status = acpi_get_handle(device->handle, "_EJ0", &temp);
 898                 if (ACPI_SUCCESS(status))
 899                         device->flags.ejectable = 1;
 900         }
 901
 902         /* Presence of _LCK indicates 'lockable' */
 903         status = acpi_get_handle(device->handle, "_LCK", &temp);
 904         if (ACPI_SUCCESS(status))
 905                 device->flags.lockable = 1;
 906
 907         /* Presence of _PS0|_PR0 indicates 'power manageable' */
 908         status = acpi_get_handle(device->handle, "_PS0", &temp);
 909         if (ACPI_FAILURE(status))
 910                 status = acpi_get_handle(device->handle, "_PR0", &temp);
 911         if (ACPI_SUCCESS(status))
 912                 device->flags.power_manageable = 1;
 913
 914         /* Presence of _PRW indicates wake capable */
 915         status = acpi_get_handle(device->handle, "_PRW", &temp);
 916         if (ACPI_SUCCESS(status))
 917                 device->flags.wake_capable = 1;
 918
 919         /* TBD: Performance management */
 920
 921         return 0;
 922 }
 923
 924 static void acpi_device_get_busid(struct acpi_device *device)
 925 {
 926         char bus_id[5] = { '?', 0 };
 927         struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
 928         int i = 0;
 929
 930         /*
 931          * Bus ID
 932          * ------
 933          * The device's Bus ID is simply the object name.
 934          * TBD: Shouldn't this value be unique (within the ACPI namespace)?
 935          */
 936         if (ACPI_IS_ROOT_DEVICE(device)) {
 937                 strcpy(device->pnp.bus_id, "ACPI");
 938                 return;
 939         }
 940
 941         switch (device->device_type) {
 942         case ACPI_BUS_TYPE_POWER_BUTTON:
 943                 strcpy(device->pnp.bus_id, "PWRF");
 944                 break;
 945         case ACPI_BUS_TYPE_SLEEP_BUTTON:
 946                 strcpy(device->pnp.bus_id, "SLPF");
 947                 break;
 948         default:
 949                 acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
 950                 /* Clean up trailing underscores (if any) */
 951                 for (i = 3; i > 1; i--) {
 952                         if (bus_id[i] == '_')
 953                                 bus_id[i] = '\0';
 954                         else
 955                                 break;
 956                 }
 957                 strcpy(device->pnp.bus_id, bus_id);
 958                 break;
 959         }
 960 }
 961
 962 /*
 963  * acpi_bay_match - see if a device is an ejectable driver bay
 964  *
 965  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
 966  * then we can safely call it an ejectable drive bay
 967  */
 968 static int acpi_bay_match(struct acpi_device *device){
 969         acpi_status status;
 970         acpi_handle handle;
 971         acpi_handle tmp;
 972         acpi_handle phandle;
 973
 974         handle = device->handle;
 975
 976         status = acpi_get_handle(handle, "_EJ0", &tmp);
 977         if (ACPI_FAILURE(status))
 978                 return -ENODEV;
 979
 980         if ((ACPI_SUCCESS(acpi_get_handle(handle, "_GTF", &tmp))) ||
 981                 (ACPI_SUCCESS(acpi_get_handle(handle, "_GTM", &tmp))) ||
 982                 (ACPI_SUCCESS(acpi_get_handle(handle, "_STM", &tmp))) ||
 983                 (ACPI_SUCCESS(acpi_get_handle(handle, "_SDD", &tmp))))
 984                 return 0;
 985
 986         if (acpi_get_parent(handle, &phandle))
 987                 return -ENODEV;
 988
 989         if ((ACPI_SUCCESS(acpi_get_handle(phandle, "_GTF", &tmp))) ||
 990                 (ACPI_SUCCESS(acpi_get_handle(phandle, "_GTM", &tmp))) ||
 991                 (ACPI_SUCCESS(acpi_get_handle(phandle, "_STM", &tmp))) ||
 992                 (ACPI_SUCCESS(acpi_get_handle(phandle, "_SDD", &tmp))))
 993                 return 0;
 994
 995         return -ENODEV;
 996 }
 997
 998 /*
 999  * acpi_dock_match - see if a device has a _DCK method
1000  */
1001 static int acpi_dock_match(struct acpi_device *device)
1002 {
1003         acpi_handle tmp;
1004         return acpi_get_handle(device->handle, "_DCK", &tmp);
1005 }
1006
1007 char *acpi_device_hid(struct acpi_device *device)
1008 {
1009         struct acpi_hardware_id *hid;
1010
1011         hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
1012         return hid->id;
1013 }
1014 EXPORT_SYMBOL(acpi_device_hid);
1015
1016 static void acpi_add_id(struct acpi_device *device, const char *dev_id)
1017 {
1018         struct acpi_hardware_id *id;
1019
1020         id = kmalloc(sizeof(*id), GFP_KERNEL);
1021         if (!id)
1022                 return;
1023
1024         id->id = kmalloc(strlen(dev_id) + 1, GFP_KERNEL);
1025         if (!id->id) {
1026                 kfree(id);
1027                 return;
1028         }
1029
1030         strcpy(id->id, dev_id);
1031         list_add_tail(&id->list, &device->pnp.ids);
1032 }
1033
1034 static void acpi_device_set_id(struct acpi_device *device)
1035 {
1036         acpi_status status;
1037         struct acpi_device_info *info;
1038         struct acpica_device_id_list *cid_list;
1039         int i;
1040
1041         switch (device->device_type) {
1042         case ACPI_BUS_TYPE_DEVICE:
1043                 if (ACPI_IS_ROOT_DEVICE(device)) {
1044                         acpi_add_id(device, ACPI_SYSTEM_HID);
1045                         break;
1046                 } else if (ACPI_IS_ROOT_DEVICE(device->parent)) {
1047                         /* \_SB_, the only root-level namespace device */
1048                         acpi_add_id(device, ACPI_BUS_HID);
1049                         strcpy(device->pnp.device_name, ACPI_BUS_DEVICE_NAME);
1050                         strcpy(device->pnp.device_class, ACPI_BUS_CLASS);
1051                         break;
1052                 }
1053
1054                 status = acpi_get_object_info(device->handle, &info);
1055                 if (ACPI_FAILURE(status)) {
1056                         printk(KERN_ERR PREFIX "%s: Error reading device info\n", __func__);
1057                         return;
1058                 }
1059
1060                 if (info->valid & ACPI_VALID_HID)
1061                         acpi_add_id(device, info->hardware_id.string);
1062                 if (info->valid & ACPI_VALID_CID) {
1063                         cid_list = &info->compatible_id_list;
1064                         for (i = 0; i < cid_list->count; i++)
1065                                 acpi_add_id(device, cid_list->ids[i].string);
1066                 }
1067                 if (info->valid & ACPI_VALID_ADR) {
1068                         device->pnp.bus_address = info->address;
1069                         device->flags.bus_address = 1;
1070                 }
1071
1072                 kfree(info);
1073
1074                 /*
1075                  * Some devices don't reliably have _HIDs & _CIDs, so add
1076                  * synthetic HIDs to make sure drivers can find them.
1077                  */
1078                 if (acpi_is_video_device(device))
1079                         acpi_add_id(device, ACPI_VIDEO_HID);
1080                 else if (ACPI_SUCCESS(acpi_bay_match(device)))
1081                         acpi_add_id(device, ACPI_BAY_HID);
1082                 else if (ACPI_SUCCESS(acpi_dock_match(device)))
1083                         acpi_add_id(device, ACPI_DOCK_HID);
1084
1085                 break;
1086         case ACPI_BUS_TYPE_POWER:
1087                 acpi_add_id(device, ACPI_POWER_HID);
1088                 break;
1089         case ACPI_BUS_TYPE_PROCESSOR:
1090                 acpi_add_id(device, ACPI_PROCESSOR_OBJECT_HID);
1091                 break;
1092         case ACPI_BUS_TYPE_THERMAL:
1093                 acpi_add_id(device, ACPI_THERMAL_HID);
1094                 break;
1095         case ACPI_BUS_TYPE_POWER_BUTTON:
1096                 acpi_add_id(device, ACPI_BUTTON_HID_POWERF);
1097                 break;
1098         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1099                 acpi_add_id(device, ACPI_BUTTON_HID_SLEEPF);
1100                 break;
1101         }
1102
1103         /*
1104          * We build acpi_devices for some objects that don't have _HID or _CID,
1105          * e.g., PCI bridges and slots.  Drivers can't bind to these objects,
1106          * but we do use them indirectly by traversing the acpi_device tree.
1107          * This generic ID isn't useful for driver binding, but it provides
1108          * the useful property that "every acpi_device has an ID."
1109          */
1110         if (list_empty(&device->pnp.ids))
1111                 acpi_add_id(device, "device");
1112 }
1113
1114 static int acpi_device_set_context(struct acpi_device *device)
1115 {
1116         acpi_status status;
1117
1118         /*
1119          * Context
1120          * -------
1121          * Attach this 'struct acpi_device' to the ACPI object.  This makes
1122          * resolutions from handle->device very efficient.  Fixed hardware
1123          * devices have no handles, so we skip them.
1124          */
1125         if (!device->handle)
1126                 return 0;
1127
1128         status = acpi_attach_data(device->handle,
1129                                   acpi_bus_data_handler, device);
1130         if (ACPI_SUCCESS(status))
1131                 return 0;
1132
1133         printk(KERN_ERR PREFIX "Error attaching device data\n");
1134         return -ENODEV;
1135 }
1136
1137 static int acpi_bus_remove(struct acpi_device *dev, int rmdevice)
1138 {
1139         if (!dev)
1140                 return -EINVAL;
1141
1142         dev->removal_type = ACPI_BUS_REMOVAL_EJECT;
1143         device_release_driver(&dev->dev);
1144
1145         if (!rmdevice)
1146                 return 0;
1147
1148         /*
1149          * unbind _ADR-Based Devices when hot removal
1150          */
1151         if (dev->flags.bus_address) {
1152                 if ((dev->parent) && (dev->parent->ops.unbind))
1153                         dev->parent->ops.unbind(dev);
1154         }
1155         acpi_device_unregister(dev, ACPI_BUS_REMOVAL_EJECT);
1156
1157         return 0;
1158 }
1159
1160 static int acpi_add_single_object(struct acpi_device **child,
1161                                   acpi_handle handle, int type,
1162                                   unsigned long long sta,
1163                                   struct acpi_bus_ops *ops)
1164 {
1165         int result;
1166         struct acpi_device *device;
1167         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1168
1169         device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1170         if (!device) {
1171                 printk(KERN_ERR PREFIX "Memory allocation error\n");
1172                 return -ENOMEM;
1173         }
1174
1175         INIT_LIST_HEAD(&device->pnp.ids);
1176         device->device_type = type;
1177         device->handle = handle;
1178         device->parent = acpi_bus_get_parent(handle);
1179         device->bus_ops = *ops; /* workround for not call .start */
1180         STRUCT_TO_INT(device->status) = sta;
1181
1182         acpi_device_get_busid(device);
1183
1184         /*
1185          * Flags
1186          * -----
1187          * Note that we only look for object handles -- cannot evaluate objects
1188          * until we know the device is present and properly initialized.
1189          */
1190         result = acpi_bus_get_flags(device);
1191         if (result)
1192                 goto end;
1193
1194         /*
1195          * Initialize Device
1196          * -----------------
1197          * TBD: Synch with Core's enumeration/initialization process.
1198          */
1199         acpi_device_set_id(device);
1200
1201         /*
1202          * Power Management
1203          * ----------------
1204          */
1205         if (device->flags.power_manageable) {
1206                 result = acpi_bus_get_power_flags(device);
1207                 if (result)
1208                         goto end;
1209         }
1210
1211         /*
1212          * Wakeup device management
1213          *-----------------------
1214          */
1215         if (device->flags.wake_capable) {
1216                 result = acpi_bus_get_wakeup_device_flags(device);
1217                 if (result)
1218                         goto end;
1219         }
1220
1221         /*
1222          * Performance Management
1223          * ----------------------
1224          */
1225         if (device->flags.performance_manageable) {
1226                 result = acpi_bus_get_perf_flags(device);
1227                 if (result)
1228                         goto end;
1229         }
1230
1231         if ((result = acpi_device_set_context(device)))
1232                 goto end;
1233
1234         result = acpi_device_register(device);
1235
1236         /*
1237          * Bind _ADR-Based Devices when hot add
1238          */
1239         if (device->flags.bus_address) {
1240                 if (device->parent && device->parent->ops.bind)
1241                         device->parent->ops.bind(device);
1242         }
1243
1244 end:
1245         if (!result) {
1246                 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
1247                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1248                         "Adding %s [%s] parent %s\n", dev_name(&device->dev),
1249                          (char *) buffer.pointer,
1250                          device->parent ? dev_name(&device->parent->dev) :
1251                                           "(null)"));
1252                 kfree(buffer.pointer);
1253                 *child = device;
1254         } else
1255                 acpi_device_release(&device->dev);
1256
1257         return result;
1258 }
1259
1260 #define ACPI_STA_DEFAULT (ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED | \
1261                           ACPI_STA_DEVICE_UI      | ACPI_STA_DEVICE_FUNCTIONING)
1262
1263 static int acpi_bus_type_and_status(acpi_handle handle, int *type,
1264                                     unsigned long long *sta)
1265 {
1266         acpi_status status;
1267         acpi_object_type acpi_type;
1268
1269         status = acpi_get_type(handle, &acpi_type);
1270         if (ACPI_FAILURE(status))
1271                 return -ENODEV;
1272
1273         switch (acpi_type) {
1274         case ACPI_TYPE_ANY:             /* for ACPI_ROOT_OBJECT */
1275         case ACPI_TYPE_DEVICE:
1276                 *type = ACPI_BUS_TYPE_DEVICE;
1277                 status = acpi_bus_get_status_handle(handle, sta);
1278                 if (ACPI_FAILURE(status))
1279                         return -ENODEV;
1280                 break;
1281         case ACPI_TYPE_PROCESSOR:
1282                 *type = ACPI_BUS_TYPE_PROCESSOR;
1283                 status = acpi_bus_get_status_handle(handle, sta);
1284                 if (ACPI_FAILURE(status))
1285                         return -ENODEV;
1286                 break;
1287         case ACPI_TYPE_THERMAL:
1288                 *type = ACPI_BUS_TYPE_THERMAL;
1289                 *sta = ACPI_STA_DEFAULT;
1290                 break;
1291         case ACPI_TYPE_POWER:
1292                 *type = ACPI_BUS_TYPE_POWER;
1293                 *sta = ACPI_STA_DEFAULT;
1294                 break;
1295         default:
1296                 return -ENODEV;
1297         }
1298
1299         return 0;
1300 }
1301
1302 static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl,
1303                                       void *context, void **return_value)
1304 {
1305         struct acpi_bus_ops *ops = context;
1306         int type;
1307         unsigned long long sta;
1308         struct acpi_device *device;
1309         acpi_status status;
1310         int result;
1311
1312         result = acpi_bus_type_and_status(handle, &type, &sta);
1313         if (result)
1314                 return AE_OK;
1315
1316         if (!(sta & ACPI_STA_DEVICE_PRESENT) &&
1317             !(sta & ACPI_STA_DEVICE_FUNCTIONING))
1318                 return AE_CTRL_DEPTH;
1319
1320         /*
1321          * We may already have an acpi_device from a previous enumeration.  If
1322          * so, we needn't add it again, but we may still have to start it.
1323          */
1324         device = NULL;
1325         acpi_bus_get_device(handle, &device);
1326         if (ops->acpi_op_add && !device)
1327                 acpi_add_single_object(&device, handle, type, sta, ops);
1328
1329         if (!device)
1330                 return AE_CTRL_DEPTH;
1331
1332         if (ops->acpi_op_start && !(ops->acpi_op_add)) {
1333                 status = acpi_start_single_object(device);
1334                 if (ACPI_FAILURE(status))
1335                         return AE_CTRL_DEPTH;
1336         }
1337
1338         if (!*return_value)
1339                 *return_value = device;
1340         return AE_OK;
1341 }
1342
1343 static int acpi_bus_scan(acpi_handle handle, struct acpi_bus_ops *ops,
1344                          struct acpi_device **child)
1345 {
1346         acpi_status status;
1347         void *device = NULL;
1348
1349         status = acpi_bus_check_add(handle, 0, ops, &device);
1350         if (ACPI_SUCCESS(status))
1351                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
1352                                     acpi_bus_check_add, NULL, ops, &device);
1353
1354         if (child)
1355                 *child = device;
1356
1357         if (device)
1358                 return 0;
1359         else
1360                 return -ENODEV;
1361 }
1362
1363 /*
1364  * acpi_bus_add and acpi_bus_start
1365  *
1366  * scan a given ACPI tree and (probably recently hot-plugged)
1367  * create and add or starts found devices.
1368  *
1369  * If no devices were found -ENODEV is returned which does not
1370  * mean that this is a real error, there just have been no suitable
1371  * ACPI objects in the table trunk from which the kernel could create
1372  * a device and add/start an appropriate driver.
1373  */
1374
1375 int
1376 acpi_bus_add(struct acpi_device **child,
1377              struct acpi_device *parent, acpi_handle handle, int type)
1378 {
1379         struct acpi_bus_ops ops;
1380
1381         memset(&ops, 0, sizeof(ops));
1382         ops.acpi_op_add = 1;
1383
1384         return acpi_bus_scan(handle, &ops, child);
1385 }
1386 EXPORT_SYMBOL(acpi_bus_add);
1387
1388 int acpi_bus_start(struct acpi_device *device)
1389 {
1390         struct acpi_bus_ops ops;
1391
1392         if (!device)
1393                 return -EINVAL;
1394
1395         memset(&ops, 0, sizeof(ops));
1396         ops.acpi_op_start = 1;
1397
1398         return acpi_bus_scan(device->handle, &ops, NULL);
1399 }
1400 EXPORT_SYMBOL(acpi_bus_start);
1401
1402 int acpi_bus_trim(struct acpi_device *start, int rmdevice)
1403 {
1404         acpi_status status;
1405         struct acpi_device *parent, *child;
1406         acpi_handle phandle, chandle;
1407         acpi_object_type type;
1408         u32 level = 1;
1409         int err = 0;
1410
1411         parent = start;
1412         phandle = start->handle;
1413         child = chandle = NULL;
1414
1415         while ((level > 0) && parent && (!err)) {
1416                 status = acpi_get_next_object(ACPI_TYPE_ANY, phandle,
1417                                               chandle, &chandle);
1418
1419                 /*
1420                  * If this scope is exhausted then move our way back up.
1421                  */
1422                 if (ACPI_FAILURE(status)) {
1423                         level--;
1424                         chandle = phandle;
1425                         acpi_get_parent(phandle, &phandle);
1426                         child = parent;
1427                         parent = parent->parent;
1428
1429                         if (level == 0)
1430                                 err = acpi_bus_remove(child, rmdevice);
1431                         else
1432                                 err = acpi_bus_remove(child, 1);
1433
1434                         continue;
1435                 }
1436
1437                 status = acpi_get_type(chandle, &type);
1438                 if (ACPI_FAILURE(status)) {
1439                         continue;
1440                 }
1441                 /*
1442                  * If there is a device corresponding to chandle then
1443                  * parse it (depth-first).
1444                  */
1445                 if (acpi_bus_get_device(chandle, &child) == 0) {
1446                         level++;
1447                         phandle = chandle;
1448                         chandle = NULL;
1449                         parent = child;
1450                 }
1451                 continue;
1452         }
1453         return err;
1454 }
1455 EXPORT_SYMBOL_GPL(acpi_bus_trim);
1456
1457 static int acpi_bus_scan_fixed(void)
1458 {
1459         int result = 0;
1460         struct acpi_device *device = NULL;
1461         struct acpi_bus_ops ops;
1462
1463         memset(&ops, 0, sizeof(ops));
1464         ops.acpi_op_add = 1;
1465         ops.acpi_op_start = 1;
1466
1467         /*
1468          * Enumerate all fixed-feature devices.
1469          */
1470         if ((acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON) == 0) {
1471                 result = acpi_add_single_object(&device, NULL,
1472                                                 ACPI_BUS_TYPE_POWER_BUTTON,
1473                                                 ACPI_STA_DEFAULT,
1474                                                 &ops);
1475         }
1476
1477         if ((acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON) == 0) {
1478                 result = acpi_add_single_object(&device, NULL,
1479                                                 ACPI_BUS_TYPE_SLEEP_BUTTON,
1480                                                 ACPI_STA_DEFAULT,
1481                                                 &ops);
1482         }
1483
1484         return result;
1485 }
1486
1487 int __init acpi_scan_init(void)
1488 {
1489         int result;
1490         struct acpi_bus_ops ops;
1491
1492         memset(&ops, 0, sizeof(ops));
1493         ops.acpi_op_add = 1;
1494         ops.acpi_op_start = 1;
1495
1496         result = bus_register(&acpi_bus_type);
1497         if (result) {
1498                 /* We don't want to quit even if we failed to add suspend/resume */
1499                 printk(KERN_ERR PREFIX "Could not register bus type\n");
1500         }
1501
1502         /*
1503          * Enumerate devices in the ACPI namespace.
1504          */
1505         result = acpi_bus_scan(ACPI_ROOT_OBJECT, &ops, &acpi_root);
1506
1507         if (!result)
1508                 result = acpi_bus_scan_fixed();
1509
1510         if (result)
1511                 acpi_device_unregister(acpi_root, ACPI_BUS_REMOVAL_NORMAL);
1512
1513         return result;
1514 }