drivers/acpi/power.c

   1 /*
   2  *  acpi_power.c - ACPI Bus Power Management ($Revision: 39 $)
   3  *
   4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6  *
   7  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License as published by
  11  *  the Free Software Foundation; either version 2 of the License, or (at
  12  *  your option) any later version.
  13  *
  14  *  This program is distributed in the hope that it will be useful, but
  15  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  *  General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License along
  20  *  with this program; if not, write to the Free Software Foundation, Inc.,
  21  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  22  *
  23  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  24  */
  25
  26 /*
  27  * ACPI power-managed devices may be controlled in two ways:
  28  * 1. via "Device Specific (D-State) Control"
  29  * 2. via "Power Resource Control".
  30  * This module is used to manage devices relying on Power Resource Control.
  31  *
  32  * An ACPI "power resource object" describes a software controllable power
  33  * plane, clock plane, or other resource used by a power managed device.
  34  * A device may rely on multiple power resources, and a power resource
  35  * may be shared by multiple devices.
  36  */
  37
  38 #include <linux/kernel.h>
  39 #include <linux/module.h>
  40 #include <linux/init.h>
  41 #include <linux/types.h>
  42 #include <linux/slab.h>
  43 #include <linux/pm_runtime.h>
  44 #include <acpi/acpi_bus.h>
  45 #include <acpi/acpi_drivers.h>
  46 #include "sleep.h"
  47 #include "internal.h"
  48
  49 #define PREFIX "ACPI: "
  50
  51 #define _COMPONENT                      ACPI_POWER_COMPONENT
  52 ACPI_MODULE_NAME("power");
  53 #define ACPI_POWER_CLASS                "power_resource"
  54 #define ACPI_POWER_DEVICE_NAME          "Power Resource"
  55 #define ACPI_POWER_FILE_INFO            "info"
  56 #define ACPI_POWER_FILE_STATUS          "state"
  57 #define ACPI_POWER_RESOURCE_STATE_OFF   0x00
  58 #define ACPI_POWER_RESOURCE_STATE_ON    0x01
  59 #define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF
  60
  61 struct acpi_power_dependent_device {
  62         struct list_head node;
  63         struct acpi_device *adev;
  64         struct work_struct work;
  65 };
  66
  67 struct acpi_power_resource {
  68         struct acpi_device device;
  69         struct list_head list_node;
  70         struct list_head dependent;
  71         char *name;
  72         u32 system_level;
  73         u32 order;
  74         unsigned int ref_count;
  75         struct mutex resource_lock;
  76 };
  77
  78 struct acpi_power_resource_entry {
  79         struct list_head node;
  80         struct acpi_power_resource *resource;
  81 };
  82
  83 static LIST_HEAD(acpi_power_resource_list);
  84 static DEFINE_MUTEX(power_resource_list_lock);
  85
  86 /* --------------------------------------------------------------------------
  87                              Power Resource Management
  88    -------------------------------------------------------------------------- */
  89
  90 static struct acpi_power_resource *acpi_power_get_context(acpi_handle handle)
  91 {
  92         struct acpi_device *device;
  93
  94         if (acpi_bus_get_device(handle, &device))
  95                 return NULL;
  96
  97         return container_of(device, struct acpi_power_resource, device);
  98 }
  99
 100 static int acpi_power_resources_list_add(acpi_handle handle,
 101                                          struct list_head *list)
 102 {
 103         struct acpi_power_resource *resource = acpi_power_get_context(handle);
 104         struct acpi_power_resource_entry *entry;
 105
 106         if (!resource || !list)
 107                 return -EINVAL;
 108
 109         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 110         if (!entry)
 111                 return -ENOMEM;
 112
 113         entry->resource = resource;
 114         if (!list_empty(list)) {
 115                 struct acpi_power_resource_entry *e;
 116
 117                 list_for_each_entry(e, list, node)
 118                         if (e->resource->order > resource->order) {
 119                                 list_add_tail(&entry->node, &e->node);
 120                                 return 0;
 121                         }
 122         }
 123         list_add_tail(&entry->node, list);
 124         return 0;
 125 }
 126
 127 void acpi_power_resources_list_free(struct list_head *list)
 128 {
 129         struct acpi_power_resource_entry *entry, *e;
 130
 131         list_for_each_entry_safe(entry, e, list, node) {
 132                 list_del(&entry->node);
 133                 kfree(entry);
 134         }
 135 }
 136
 137 int acpi_extract_power_resources(union acpi_object *package, unsigned int start,
 138                                  struct list_head *list)
 139 {
 140         unsigned int i;
 141         int err = 0;
 142
 143         for (i = start; i < package->package.count; i++) {
 144                 union acpi_object *element = &package->package.elements[i];
 145                 acpi_handle rhandle;
 146
 147                 if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
 148                         err = -ENODATA;
 149                         break;
 150                 }
 151                 rhandle = element->reference.handle;
 152                 if (!rhandle) {
 153                         err = -ENODEV;
 154                         break;
 155                 }
 156                 err = acpi_add_power_resource(rhandle);
 157                 if (err)
 158                         break;
 159
 160                 err = acpi_power_resources_list_add(rhandle, list);
 161                 if (err)
 162                         break;
 163         }
 164         if (err)
 165                 acpi_power_resources_list_free(list);
 166
 167         return err;
 168 }
 169
 170 static int acpi_power_get_state(acpi_handle handle, int *state)
 171 {
 172         acpi_status status = AE_OK;
 173         unsigned long long sta = 0;
 174         char node_name[5];
 175         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 176
 177
 178         if (!handle || !state)
 179                 return -EINVAL;
 180
 181         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 182         if (ACPI_FAILURE(status))
 183                 return -ENODEV;
 184
 185         *state = (sta & 0x01)?ACPI_POWER_RESOURCE_STATE_ON:
 186                               ACPI_POWER_RESOURCE_STATE_OFF;
 187
 188         acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 189
 190         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
 191                           node_name,
 192                                 *state ? "on" : "off"));
 193
 194         return 0;
 195 }
 196
 197 static int acpi_power_get_list_state(struct list_head *list, int *state)
 198 {
 199         struct acpi_power_resource_entry *entry;
 200         int cur_state;
 201
 202         if (!list || !state)
 203                 return -EINVAL;
 204
 205         /* The state of the list is 'on' IFF all resources are 'on'. */
 206         list_for_each_entry(entry, list, node) {
 207                 struct acpi_power_resource *resource = entry->resource;
 208                 acpi_handle handle = resource->device.handle;
 209                 int result;
 210
 211                 mutex_lock(&resource->resource_lock);
 212                 result = acpi_power_get_state(handle, &cur_state);
 213                 mutex_unlock(&resource->resource_lock);
 214                 if (result)
 215                         return result;
 216
 217                 if (cur_state != ACPI_POWER_RESOURCE_STATE_ON)
 218                         break;
 219         }
 220
 221         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
 222                           cur_state ? "on" : "off"));
 223
 224         *state = cur_state;
 225         return 0;
 226 }
 227
 228 static void acpi_power_resume_dependent(struct work_struct *work)
 229 {
 230         struct acpi_power_dependent_device *dep;
 231         struct acpi_device_physical_node *pn;
 232         struct acpi_device *adev;
 233         int state;
 234
 235         dep = container_of(work, struct acpi_power_dependent_device, work);
 236         adev = dep->adev;
 237         if (acpi_power_get_inferred_state(adev, &state))
 238                 return;
 239
 240         if (state > ACPI_STATE_D0)
 241                 return;
 242
 243         mutex_lock(&adev->physical_node_lock);
 244
 245         list_for_each_entry(pn, &adev->physical_node_list, node)
 246                 pm_request_resume(pn->dev);
 247
 248         list_for_each_entry(pn, &adev->power_dependent, node)
 249                 pm_request_resume(pn->dev);
 250
 251         mutex_unlock(&adev->physical_node_lock);
 252 }
 253
 254 static int __acpi_power_on(struct acpi_power_resource *resource)
 255 {
 256         acpi_status status = AE_OK;
 257
 258         status = acpi_evaluate_object(resource->device.handle, "_ON", NULL, NULL);
 259         if (ACPI_FAILURE(status))
 260                 return -ENODEV;
 261
 262         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned on\n",
 263                           resource->name));
 264
 265         return 0;
 266 }
 267
 268 static int acpi_power_on(struct acpi_power_resource *resource)
 269 {
 270         int result = 0;;
 271
 272         mutex_lock(&resource->resource_lock);
 273
 274         if (resource->ref_count++) {
 275                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 276                                   "Power resource [%s] already on",
 277                                   resource->name));
 278         } else {
 279                 result = __acpi_power_on(resource);
 280                 if (result) {
 281                         resource->ref_count--;
 282                 } else {
 283                         struct acpi_power_dependent_device *dep;
 284
 285                         list_for_each_entry(dep, &resource->dependent, node)
 286                                 schedule_work(&dep->work);
 287                 }
 288         }
 289
 290         mutex_unlock(&resource->resource_lock);
 291
 292         return result;
 293 }
 294
 295 static int acpi_power_off(struct acpi_power_resource *resource)
 296 {
 297         acpi_status status = AE_OK;
 298         int result = 0;
 299
 300         mutex_lock(&resource->resource_lock);
 301
 302         if (!resource->ref_count) {
 303                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 304                                   "Power resource [%s] already off",
 305                                   resource->name));
 306                 goto unlock;
 307         }
 308
 309         if (--resource->ref_count) {
 310                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 311                                   "Power resource [%s] still in use\n",
 312                                   resource->name));
 313                 goto unlock;
 314         }
 315
 316         status = acpi_evaluate_object(resource->device.handle, "_OFF", NULL, NULL);
 317         if (ACPI_FAILURE(status))
 318                 result = -ENODEV;
 319         else
 320                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 321                                   "Power resource [%s] turned off\n",
 322                                   resource->name));
 323
 324  unlock:
 325         mutex_unlock(&resource->resource_lock);
 326
 327         return result;
 328 }
 329
 330 static int acpi_power_off_list(struct list_head *list)
 331 {
 332         struct acpi_power_resource_entry *entry;
 333         int result = 0;
 334
 335         list_for_each_entry_reverse(entry, list, node) {
 336                 result = acpi_power_off(entry->resource);
 337                 if (result)
 338                         goto err;
 339         }
 340         return 0;
 341
 342  err:
 343         list_for_each_entry_continue(entry, list, node)
 344                 acpi_power_on(entry->resource);
 345
 346         return result;
 347 }
 348
 349 static int acpi_power_on_list(struct list_head *list)
 350 {
 351         struct acpi_power_resource_entry *entry;
 352         int result = 0;
 353
 354         list_for_each_entry(entry, list, node) {
 355                 result = acpi_power_on(entry->resource);
 356                 if (result)
 357                         goto err;
 358         }
 359         return 0;
 360
 361  err:
 362         list_for_each_entry_continue_reverse(entry, list, node)
 363                 acpi_power_off(entry->resource);
 364
 365         return result;
 366 }
 367
 368 static void acpi_power_add_dependent(struct acpi_power_resource *resource,
 369                                      struct acpi_device *adev)
 370 {
 371         struct acpi_power_dependent_device *dep;
 372
 373         mutex_lock(&resource->resource_lock);
 374
 375         list_for_each_entry(dep, &resource->dependent, node)
 376                 if (dep->adev == adev)
 377                         goto out;
 378
 379         dep = kzalloc(sizeof(*dep), GFP_KERNEL);
 380         if (!dep)
 381                 goto out;
 382
 383         dep->adev = adev;
 384         INIT_WORK(&dep->work, acpi_power_resume_dependent);
 385         list_add_tail(&dep->node, &resource->dependent);
 386
 387  out:
 388         mutex_unlock(&resource->resource_lock);
 389 }
 390
 391 static void acpi_power_remove_dependent(struct acpi_power_resource *resource,
 392                                         struct acpi_device *adev)
 393 {
 394         struct acpi_power_dependent_device *dep;
 395         struct work_struct *work = NULL;
 396
 397         mutex_lock(&resource->resource_lock);
 398
 399         list_for_each_entry(dep, &resource->dependent, node)
 400                 if (dep->adev == adev) {
 401                         list_del(&dep->node);
 402                         work = &dep->work;
 403                         break;
 404                 }
 405
 406         mutex_unlock(&resource->resource_lock);
 407
 408         if (work) {
 409                 cancel_work_sync(work);
 410                 kfree(dep);
 411         }
 412 }
 413
 414 void acpi_power_add_remove_device(struct acpi_device *adev, bool add)
 415 {
 416         if (adev->power.flags.power_resources) {
 417                 struct acpi_device_power_state *ps;
 418                 struct acpi_power_resource_entry *entry;
 419
 420                 ps = &adev->power.states[ACPI_STATE_D0];
 421                 list_for_each_entry(entry, &ps->resources, node) {
 422                         struct acpi_power_resource *resource = entry->resource;
 423
 424                         if (add)
 425                                 acpi_power_add_dependent(resource, adev);
 426                         else
 427                                 acpi_power_remove_dependent(resource, adev);
 428                 }
 429         }
 430 }
 431
 432 int acpi_power_min_system_level(struct list_head *list)
 433 {
 434         struct acpi_power_resource_entry *entry;
 435         int system_level = 5;
 436
 437         list_for_each_entry(entry, list, node) {
 438                 struct acpi_power_resource *resource = entry->resource;
 439
 440                 if (system_level > resource->system_level)
 441                         system_level = resource->system_level;
 442         }
 443         return system_level;
 444 }
 445
 446 /* --------------------------------------------------------------------------
 447                              Device Power Management
 448    -------------------------------------------------------------------------- */
 449
 450 /**
 451  * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
 452  *                          ACPI 3.0) _PSW (Power State Wake)
 453  * @dev: Device to handle.
 454  * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
 455  * @sleep_state: Target sleep state of the system.
 456  * @dev_state: Target power state of the device.
 457  *
 458  * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 459  * State Wake) for the device, if present.  On failure reset the device's
 460  * wakeup.flags.valid flag.
 461  *
 462  * RETURN VALUE:
 463  * 0 if either _DSW or _PSW has been successfully executed
 464  * 0 if neither _DSW nor _PSW has been found
 465  * -ENODEV if the execution of either _DSW or _PSW has failed
 466  */
 467 int acpi_device_sleep_wake(struct acpi_device *dev,
 468                            int enable, int sleep_state, int dev_state)
 469 {
 470         union acpi_object in_arg[3];
 471         struct acpi_object_list arg_list = { 3, in_arg };
 472         acpi_status status = AE_OK;
 473
 474         /*
 475          * Try to execute _DSW first.
 476          *
 477          * Three agruments are needed for the _DSW object:
 478          * Argument 0: enable/disable the wake capabilities
 479          * Argument 1: target system state
 480          * Argument 2: target device state
 481          * When _DSW object is called to disable the wake capabilities, maybe
 482          * the first argument is filled. The values of the other two agruments
 483          * are meaningless.
 484          */
 485         in_arg[0].type = ACPI_TYPE_INTEGER;
 486         in_arg[0].integer.value = enable;
 487         in_arg[1].type = ACPI_TYPE_INTEGER;
 488         in_arg[1].integer.value = sleep_state;
 489         in_arg[2].type = ACPI_TYPE_INTEGER;
 490         in_arg[2].integer.value = dev_state;
 491         status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
 492         if (ACPI_SUCCESS(status)) {
 493                 return 0;
 494         } else if (status != AE_NOT_FOUND) {
 495                 printk(KERN_ERR PREFIX "_DSW execution failed\n");
 496                 dev->wakeup.flags.valid = 0;
 497                 return -ENODEV;
 498         }
 499
 500         /* Execute _PSW */
 501         arg_list.count = 1;
 502         in_arg[0].integer.value = enable;
 503         status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
 504         if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
 505                 printk(KERN_ERR PREFIX "_PSW execution failed\n");
 506                 dev->wakeup.flags.valid = 0;
 507                 return -ENODEV;
 508         }
 509
 510         return 0;
 511 }
 512
 513 /*
 514  * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
 515  * 1. Power on the power resources required for the wakeup device
 516  * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 517  *    State Wake) for the device, if present
 518  */
 519 int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
 520 {
 521         int err = 0;
 522
 523         if (!dev || !dev->wakeup.flags.valid)
 524                 return -EINVAL;
 525
 526         mutex_lock(&acpi_device_lock);
 527
 528         if (dev->wakeup.prepare_count++)
 529                 goto out;
 530
 531         err = acpi_power_on_list(&dev->wakeup.resources);
 532         if (err) {
 533                 dev_err(&dev->dev, "Cannot turn wakeup power resources on\n");
 534                 dev->wakeup.flags.valid = 0;
 535         } else {
 536                 /*
 537                  * Passing 3 as the third argument below means the device may be
 538                  * put into arbitrary power state afterward.
 539                  */
 540                 err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
 541         }
 542         if (err)
 543                 dev->wakeup.prepare_count = 0;
 544
 545  out:
 546         mutex_unlock(&acpi_device_lock);
 547         return err;
 548 }
 549
 550 /*
 551  * Shutdown a wakeup device, counterpart of above method
 552  * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 553  *    State Wake) for the device, if present
 554  * 2. Shutdown down the power resources
 555  */
 556 int acpi_disable_wakeup_device_power(struct acpi_device *dev)
 557 {
 558         int err = 0;
 559
 560         if (!dev || !dev->wakeup.flags.valid)
 561                 return -EINVAL;
 562
 563         mutex_lock(&acpi_device_lock);
 564
 565         if (--dev->wakeup.prepare_count > 0)
 566                 goto out;
 567
 568         /*
 569          * Executing the code below even if prepare_count is already zero when
 570          * the function is called may be useful, for example for initialisation.
 571          */
 572         if (dev->wakeup.prepare_count < 0)
 573                 dev->wakeup.prepare_count = 0;
 574
 575         err = acpi_device_sleep_wake(dev, 0, 0, 0);
 576         if (err)
 577                 goto out;
 578
 579         err = acpi_power_off_list(&dev->wakeup.resources);
 580         if (err) {
 581                 dev_err(&dev->dev, "Cannot turn wakeup power resources off\n");
 582                 dev->wakeup.flags.valid = 0;
 583         }
 584
 585  out:
 586         mutex_unlock(&acpi_device_lock);
 587         return err;
 588 }
 589
 590 int acpi_power_get_inferred_state(struct acpi_device *device, int *state)
 591 {
 592         int result = 0;
 593         int list_state = 0;
 594         int i = 0;
 595
 596         if (!device || !state)
 597                 return -EINVAL;
 598
 599         /*
 600          * We know a device's inferred power state when all the resources
 601          * required for a given D-state are 'on'.
 602          */
 603         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
 604                 struct list_head *list = &device->power.states[i].resources;
 605
 606                 if (list_empty(list))
 607                         continue;
 608
 609                 result = acpi_power_get_list_state(list, &list_state);
 610                 if (result)
 611                         return result;
 612
 613                 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
 614                         *state = i;
 615                         return 0;
 616                 }
 617         }
 618
 619         *state = ACPI_STATE_D3;
 620         return 0;
 621 }
 622
 623 int acpi_power_on_resources(struct acpi_device *device, int state)
 624 {
 625         if (!device || state < ACPI_STATE_D0 || state > ACPI_STATE_D3_COLD)
 626                 return -EINVAL;
 627
 628         if (state == ACPI_STATE_D3_COLD)
 629                 return 0;
 630
 631         return acpi_power_on_list(&device->power.states[state].resources);
 632 }
 633
 634 int acpi_power_transition(struct acpi_device *device, int state)
 635 {
 636         int result = 0;
 637
 638         if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
 639                 return -EINVAL;
 640
 641         if (device->power.state == state || !device->flags.power_manageable)
 642                 return 0;
 643
 644         if ((device->power.state < ACPI_STATE_D0)
 645             || (device->power.state > ACPI_STATE_D3_COLD))
 646                 return -ENODEV;
 647
 648         /* TBD: Resources must be ordered. */
 649
 650         /*
 651          * First we reference all power resources required in the target list
 652          * (e.g. so the device doesn't lose power while transitioning).  Then,
 653          * we dereference all power resources used in the current list.
 654          */
 655         if (state < ACPI_STATE_D3_COLD)
 656                 result = acpi_power_on_list(
 657                         &device->power.states[state].resources);
 658
 659         if (!result && device->power.state < ACPI_STATE_D3_COLD)
 660                 acpi_power_off_list(
 661                         &device->power.states[device->power.state].resources);
 662
 663         /* We shouldn't change the state unless the above operations succeed. */
 664         device->power.state = result ? ACPI_STATE_UNKNOWN : state;
 665
 666         return result;
 667 }
 668
 669 static void acpi_release_power_resource(struct device *dev)
 670 {
 671         struct acpi_device *device = to_acpi_device(dev);
 672         struct acpi_power_resource *resource;
 673
 674         resource = container_of(device, struct acpi_power_resource, device);
 675
 676         mutex_lock(&power_resource_list_lock);
 677         list_del(&resource->list_node);
 678         mutex_unlock(&power_resource_list_lock);
 679
 680         acpi_free_ids(device);
 681         kfree(resource);
 682 }
 683
 684 int acpi_add_power_resource(acpi_handle handle)
 685 {
 686         struct acpi_power_resource *resource;
 687         struct acpi_device *device = NULL;
 688         union acpi_object acpi_object;
 689         struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
 690         acpi_status status;
 691         int state, result = -ENODEV;
 692
 693         acpi_bus_get_device(handle, &device);
 694         if (device)
 695                 return 0;
 696
 697         resource = kzalloc(sizeof(*resource), GFP_KERNEL);
 698         if (!resource)
 699                 return -ENOMEM;
 700
 701         device = &resource->device;
 702         acpi_init_device_object(device, handle, ACPI_BUS_TYPE_POWER,
 703                                 ACPI_STA_DEFAULT);
 704         mutex_init(&resource->resource_lock);
 705         INIT_LIST_HEAD(&resource->dependent);
 706         resource->name = device->pnp.bus_id;
 707         strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
 708         strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
 709         device->power.state = ACPI_STATE_UNKNOWN;
 710
 711         /* Evalute the object to get the system level and resource order. */
 712         status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
 713         if (ACPI_FAILURE(status))
 714                 goto err;
 715
 716         resource->system_level = acpi_object.power_resource.system_level;
 717         resource->order = acpi_object.power_resource.resource_order;
 718
 719         result = acpi_power_get_state(handle, &state);
 720         if (result)
 721                 goto err;
 722
 723         printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
 724                acpi_device_bid(device), state ? "on" : "off");
 725
 726         device->flags.match_driver = true;
 727         result = acpi_device_register(device, acpi_release_power_resource);
 728         if (result)
 729                 goto err;
 730
 731         mutex_lock(&power_resource_list_lock);
 732         list_add(&resource->list_node, &acpi_power_resource_list);
 733         mutex_unlock(&power_resource_list_lock);
 734         return 0;
 735
 736  err:
 737         acpi_release_power_resource(&device->dev);
 738         return result;
 739 }
 740
 741 #ifdef CONFIG_ACPI_SLEEP
 742 void acpi_resume_power_resources(void)
 743 {
 744         struct acpi_power_resource *resource;
 745
 746         mutex_lock(&power_resource_list_lock);
 747
 748         list_for_each_entry(resource, &acpi_power_resource_list, list_node) {
 749                 int result, state;
 750
 751                 mutex_lock(&resource->resource_lock);
 752
 753                 result = acpi_power_get_state(resource->device.handle, &state);
 754                 if (!result && state == ACPI_POWER_RESOURCE_STATE_OFF
 755                     && resource->ref_count) {
 756                         dev_info(&resource->device.dev, "Turning ON\n");
 757                         __acpi_power_on(resource);
 758                 }
 759
 760                 mutex_unlock(&resource->resource_lock);
 761         }
 762
 763         mutex_unlock(&power_resource_list_lock);
 764 }
 765 #endif