linux/drivers/acpi/power.c
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   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 <linux/sysfs.h>
  45#include <acpi/acpi_bus.h>
  46#include <acpi/acpi_drivers.h>
  47#include "sleep.h"
  48#include "internal.h"
  49
  50#define PREFIX "ACPI: "
  51
  52#define _COMPONENT                      ACPI_POWER_COMPONENT
  53ACPI_MODULE_NAME("power");
  54#define ACPI_POWER_CLASS                "power_resource"
  55#define ACPI_POWER_DEVICE_NAME          "Power Resource"
  56#define ACPI_POWER_FILE_INFO            "info"
  57#define ACPI_POWER_FILE_STATUS          "state"
  58#define ACPI_POWER_RESOURCE_STATE_OFF   0x00
  59#define ACPI_POWER_RESOURCE_STATE_ON    0x01
  60#define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF
  61
  62struct acpi_power_dependent_device {
  63        struct list_head node;
  64        struct acpi_device *adev;
  65        struct work_struct work;
  66};
  67
  68struct acpi_power_resource {
  69        struct acpi_device device;
  70        struct list_head list_node;
  71        struct list_head dependent;
  72        char *name;
  73        u32 system_level;
  74        u32 order;
  75        unsigned int ref_count;
  76        bool wakeup_enabled;
  77        struct mutex resource_lock;
  78};
  79
  80struct acpi_power_resource_entry {
  81        struct list_head node;
  82        struct acpi_power_resource *resource;
  83};
  84
  85static LIST_HEAD(acpi_power_resource_list);
  86static DEFINE_MUTEX(power_resource_list_lock);
  87
  88/* --------------------------------------------------------------------------
  89                             Power Resource Management
  90   -------------------------------------------------------------------------- */
  91
  92static inline
  93struct acpi_power_resource *to_power_resource(struct acpi_device *device)
  94{
  95        return container_of(device, struct acpi_power_resource, device);
  96}
  97
  98static struct acpi_power_resource *acpi_power_get_context(acpi_handle handle)
  99{
 100        struct acpi_device *device;
 101
 102        if (acpi_bus_get_device(handle, &device))
 103                return NULL;
 104
 105        return to_power_resource(device);
 106}
 107
 108static int acpi_power_resources_list_add(acpi_handle handle,
 109                                         struct list_head *list)
 110{
 111        struct acpi_power_resource *resource = acpi_power_get_context(handle);
 112        struct acpi_power_resource_entry *entry;
 113
 114        if (!resource || !list)
 115                return -EINVAL;
 116
 117        entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 118        if (!entry)
 119                return -ENOMEM;
 120
 121        entry->resource = resource;
 122        if (!list_empty(list)) {
 123                struct acpi_power_resource_entry *e;
 124
 125                list_for_each_entry(e, list, node)
 126                        if (e->resource->order > resource->order) {
 127                                list_add_tail(&entry->node, &e->node);
 128                                return 0;
 129                        }
 130        }
 131        list_add_tail(&entry->node, list);
 132        return 0;
 133}
 134
 135void acpi_power_resources_list_free(struct list_head *list)
 136{
 137        struct acpi_power_resource_entry *entry, *e;
 138
 139        list_for_each_entry_safe(entry, e, list, node) {
 140                list_del(&entry->node);
 141                kfree(entry);
 142        }
 143}
 144
 145int acpi_extract_power_resources(union acpi_object *package, unsigned int start,
 146                                 struct list_head *list)
 147{
 148        unsigned int i;
 149        int err = 0;
 150
 151        for (i = start; i < package->package.count; i++) {
 152                union acpi_object *element = &package->package.elements[i];
 153                acpi_handle rhandle;
 154
 155                if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
 156                        err = -ENODATA;
 157                        break;
 158                }
 159                rhandle = element->reference.handle;
 160                if (!rhandle) {
 161                        err = -ENODEV;
 162                        break;
 163                }
 164                err = acpi_add_power_resource(rhandle);
 165                if (err)
 166                        break;
 167
 168                err = acpi_power_resources_list_add(rhandle, list);
 169                if (err)
 170                        break;
 171        }
 172        if (err)
 173                acpi_power_resources_list_free(list);
 174
 175        return err;
 176}
 177
 178static int acpi_power_get_state(acpi_handle handle, int *state)
 179{
 180        acpi_status status = AE_OK;
 181        unsigned long long sta = 0;
 182        char node_name[5];
 183        struct acpi_buffer buffer = { sizeof(node_name), node_name };
 184
 185
 186        if (!handle || !state)
 187                return -EINVAL;
 188
 189        status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 190        if (ACPI_FAILURE(status))
 191                return -ENODEV;
 192
 193        *state = (sta & 0x01)?ACPI_POWER_RESOURCE_STATE_ON:
 194                              ACPI_POWER_RESOURCE_STATE_OFF;
 195
 196        acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 197
 198        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
 199                          node_name,
 200                                *state ? "on" : "off"));
 201
 202        return 0;
 203}
 204
 205static int acpi_power_get_list_state(struct list_head *list, int *state)
 206{
 207        struct acpi_power_resource_entry *entry;
 208        int cur_state;
 209
 210        if (!list || !state)
 211                return -EINVAL;
 212
 213        /* The state of the list is 'on' IFF all resources are 'on'. */
 214        list_for_each_entry(entry, list, node) {
 215                struct acpi_power_resource *resource = entry->resource;
 216                acpi_handle handle = resource->device.handle;
 217                int result;
 218
 219                mutex_lock(&resource->resource_lock);
 220                result = acpi_power_get_state(handle, &cur_state);
 221                mutex_unlock(&resource->resource_lock);
 222                if (result)
 223                        return result;
 224
 225                if (cur_state != ACPI_POWER_RESOURCE_STATE_ON)
 226                        break;
 227        }
 228
 229        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
 230                          cur_state ? "on" : "off"));
 231
 232        *state = cur_state;
 233        return 0;
 234}
 235
 236static void acpi_power_resume_dependent(struct work_struct *work)
 237{
 238        struct acpi_power_dependent_device *dep;
 239        struct acpi_device_physical_node *pn;
 240        struct acpi_device *adev;
 241        int state;
 242
 243        dep = container_of(work, struct acpi_power_dependent_device, work);
 244        adev = dep->adev;
 245        if (acpi_power_get_inferred_state(adev, &state))
 246                return;
 247
 248        if (state > ACPI_STATE_D0)
 249                return;
 250
 251        mutex_lock(&adev->physical_node_lock);
 252
 253        list_for_each_entry(pn, &adev->physical_node_list, node)
 254                pm_request_resume(pn->dev);
 255
 256        list_for_each_entry(pn, &adev->power_dependent, node)
 257                pm_request_resume(pn->dev);
 258
 259        mutex_unlock(&adev->physical_node_lock);
 260}
 261
 262static int __acpi_power_on(struct acpi_power_resource *resource)
 263{
 264        acpi_status status = AE_OK;
 265
 266        status = acpi_evaluate_object(resource->device.handle, "_ON", NULL, NULL);
 267        if (ACPI_FAILURE(status))
 268                return -ENODEV;
 269
 270        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned on\n",
 271                          resource->name));
 272
 273        return 0;
 274}
 275
 276static int acpi_power_on_unlocked(struct acpi_power_resource *resource)
 277{
 278        int result = 0;
 279
 280        if (resource->ref_count++) {
 281                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 282                                  "Power resource [%s] already on",
 283                                  resource->name));
 284        } else {
 285                result = __acpi_power_on(resource);
 286                if (result) {
 287                        resource->ref_count--;
 288                } else {
 289                        struct acpi_power_dependent_device *dep;
 290
 291                        list_for_each_entry(dep, &resource->dependent, node)
 292                                schedule_work(&dep->work);
 293                }
 294        }
 295        return result;
 296}
 297
 298static int acpi_power_on(struct acpi_power_resource *resource)
 299{
 300        int result;
 301
 302        mutex_lock(&resource->resource_lock);
 303        result = acpi_power_on_unlocked(resource);
 304        mutex_unlock(&resource->resource_lock);
 305        return result;
 306}
 307
 308static int __acpi_power_off(struct acpi_power_resource *resource)
 309{
 310        acpi_status status;
 311
 312        status = acpi_evaluate_object(resource->device.handle, "_OFF",
 313                                      NULL, NULL);
 314        if (ACPI_FAILURE(status))
 315                return -ENODEV;
 316
 317        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned off\n",
 318                          resource->name));
 319        return 0;
 320}
 321
 322static int acpi_power_off_unlocked(struct acpi_power_resource *resource)
 323{
 324        int result = 0;
 325
 326        if (!resource->ref_count) {
 327                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 328                                  "Power resource [%s] already off",
 329                                  resource->name));
 330                return 0;
 331        }
 332
 333        if (--resource->ref_count) {
 334                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 335                                  "Power resource [%s] still in use\n",
 336                                  resource->name));
 337        } else {
 338                result = __acpi_power_off(resource);
 339                if (result)
 340                        resource->ref_count++;
 341        }
 342        return result;
 343}
 344
 345static int acpi_power_off(struct acpi_power_resource *resource)
 346{
 347        int result;
 348
 349        mutex_lock(&resource->resource_lock);
 350        result = acpi_power_off_unlocked(resource);
 351        mutex_unlock(&resource->resource_lock);
 352        return result;
 353}
 354
 355static int acpi_power_off_list(struct list_head *list)
 356{
 357        struct acpi_power_resource_entry *entry;
 358        int result = 0;
 359
 360        list_for_each_entry_reverse(entry, list, node) {
 361                result = acpi_power_off(entry->resource);
 362                if (result)
 363                        goto err;
 364        }
 365        return 0;
 366
 367 err:
 368        list_for_each_entry_continue(entry, list, node)
 369                acpi_power_on(entry->resource);
 370
 371        return result;
 372}
 373
 374static int acpi_power_on_list(struct list_head *list)
 375{
 376        struct acpi_power_resource_entry *entry;
 377        int result = 0;
 378
 379        list_for_each_entry(entry, list, node) {
 380                result = acpi_power_on(entry->resource);
 381                if (result)
 382                        goto err;
 383        }
 384        return 0;
 385
 386 err:
 387        list_for_each_entry_continue_reverse(entry, list, node)
 388                acpi_power_off(entry->resource);
 389
 390        return result;
 391}
 392
 393static void acpi_power_add_dependent(struct acpi_power_resource *resource,
 394                                     struct acpi_device *adev)
 395{
 396        struct acpi_power_dependent_device *dep;
 397
 398        mutex_lock(&resource->resource_lock);
 399
 400        list_for_each_entry(dep, &resource->dependent, node)
 401                if (dep->adev == adev)
 402                        goto out;
 403
 404        dep = kzalloc(sizeof(*dep), GFP_KERNEL);
 405        if (!dep)
 406                goto out;
 407
 408        dep->adev = adev;
 409        INIT_WORK(&dep->work, acpi_power_resume_dependent);
 410        list_add_tail(&dep->node, &resource->dependent);
 411
 412 out:
 413        mutex_unlock(&resource->resource_lock);
 414}
 415
 416static void acpi_power_remove_dependent(struct acpi_power_resource *resource,
 417                                        struct acpi_device *adev)
 418{
 419        struct acpi_power_dependent_device *dep;
 420        struct work_struct *work = NULL;
 421
 422        mutex_lock(&resource->resource_lock);
 423
 424        list_for_each_entry(dep, &resource->dependent, node)
 425                if (dep->adev == adev) {
 426                        list_del(&dep->node);
 427                        work = &dep->work;
 428                        break;
 429                }
 430
 431        mutex_unlock(&resource->resource_lock);
 432
 433        if (work) {
 434                cancel_work_sync(work);
 435                kfree(dep);
 436        }
 437}
 438
 439static struct attribute *attrs[] = {
 440        NULL,
 441};
 442
 443static struct attribute_group attr_groups[] = {
 444        [ACPI_STATE_D0] = {
 445                .name = "power_resources_D0",
 446                .attrs = attrs,
 447        },
 448        [ACPI_STATE_D1] = {
 449                .name = "power_resources_D1",
 450                .attrs = attrs,
 451        },
 452        [ACPI_STATE_D2] = {
 453                .name = "power_resources_D2",
 454                .attrs = attrs,
 455        },
 456        [ACPI_STATE_D3_HOT] = {
 457                .name = "power_resources_D3hot",
 458                .attrs = attrs,
 459        },
 460};
 461
 462static void acpi_power_hide_list(struct acpi_device *adev, int state)
 463{
 464        struct acpi_device_power_state *ps = &adev->power.states[state];
 465        struct acpi_power_resource_entry *entry;
 466
 467        if (list_empty(&ps->resources))
 468                return;
 469
 470        list_for_each_entry_reverse(entry, &ps->resources, node) {
 471                struct acpi_device *res_dev = &entry->resource->device;
 472
 473                sysfs_remove_link_from_group(&adev->dev.kobj,
 474                                             attr_groups[state].name,
 475                                             dev_name(&res_dev->dev));
 476        }
 477        sysfs_remove_group(&adev->dev.kobj, &attr_groups[state]);
 478}
 479
 480static void acpi_power_expose_list(struct acpi_device *adev, int state)
 481{
 482        struct acpi_device_power_state *ps = &adev->power.states[state];
 483        struct acpi_power_resource_entry *entry;
 484        int ret;
 485
 486        if (list_empty(&ps->resources))
 487                return;
 488
 489        ret = sysfs_create_group(&adev->dev.kobj, &attr_groups[state]);
 490        if (ret)
 491                return;
 492
 493        list_for_each_entry(entry, &ps->resources, node) {
 494                struct acpi_device *res_dev = &entry->resource->device;
 495
 496                ret = sysfs_add_link_to_group(&adev->dev.kobj,
 497                                              attr_groups[state].name,
 498                                              &res_dev->dev.kobj,
 499                                              dev_name(&res_dev->dev));
 500                if (ret) {
 501                        acpi_power_hide_list(adev, state);
 502                        break;
 503                }
 504        }
 505}
 506
 507void acpi_power_add_remove_device(struct acpi_device *adev, bool add)
 508{
 509        struct acpi_device_power_state *ps;
 510        struct acpi_power_resource_entry *entry;
 511        int state;
 512
 513        if (!adev->power.flags.power_resources)
 514                return;
 515
 516        ps = &adev->power.states[ACPI_STATE_D0];
 517        list_for_each_entry(entry, &ps->resources, node) {
 518                struct acpi_power_resource *resource = entry->resource;
 519
 520                if (add)
 521                        acpi_power_add_dependent(resource, adev);
 522                else
 523                        acpi_power_remove_dependent(resource, adev);
 524        }
 525
 526        for (state = ACPI_STATE_D0; state <= ACPI_STATE_D3_HOT; state++) {
 527                if (add)
 528                        acpi_power_expose_list(adev, state);
 529                else
 530                        acpi_power_hide_list(adev, state);
 531        }
 532}
 533
 534int acpi_power_wakeup_list_init(struct list_head *list, int *system_level_p)
 535{
 536        struct acpi_power_resource_entry *entry;
 537        int system_level = 5;
 538
 539        list_for_each_entry(entry, list, node) {
 540                struct acpi_power_resource *resource = entry->resource;
 541                acpi_handle handle = resource->device.handle;
 542                int result;
 543                int state;
 544
 545                mutex_lock(&resource->resource_lock);
 546
 547                result = acpi_power_get_state(handle, &state);
 548                if (result) {
 549                        mutex_unlock(&resource->resource_lock);
 550                        return result;
 551                }
 552                if (state == ACPI_POWER_RESOURCE_STATE_ON) {
 553                        resource->ref_count++;
 554                        resource->wakeup_enabled = true;
 555                }
 556                if (system_level > resource->system_level)
 557                        system_level = resource->system_level;
 558
 559                mutex_unlock(&resource->resource_lock);
 560        }
 561        *system_level_p = system_level;
 562        return 0;
 563}
 564
 565/* --------------------------------------------------------------------------
 566                             Device Power Management
 567   -------------------------------------------------------------------------- */
 568
 569/**
 570 * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
 571 *                          ACPI 3.0) _PSW (Power State Wake)
 572 * @dev: Device to handle.
 573 * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
 574 * @sleep_state: Target sleep state of the system.
 575 * @dev_state: Target power state of the device.
 576 *
 577 * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 578 * State Wake) for the device, if present.  On failure reset the device's
 579 * wakeup.flags.valid flag.
 580 *
 581 * RETURN VALUE:
 582 * 0 if either _DSW or _PSW has been successfully executed
 583 * 0 if neither _DSW nor _PSW has been found
 584 * -ENODEV if the execution of either _DSW or _PSW has failed
 585 */
 586int acpi_device_sleep_wake(struct acpi_device *dev,
 587                           int enable, int sleep_state, int dev_state)
 588{
 589        union acpi_object in_arg[3];
 590        struct acpi_object_list arg_list = { 3, in_arg };
 591        acpi_status status = AE_OK;
 592
 593        /*
 594         * Try to execute _DSW first.
 595         *
 596         * Three agruments are needed for the _DSW object:
 597         * Argument 0: enable/disable the wake capabilities
 598         * Argument 1: target system state
 599         * Argument 2: target device state
 600         * When _DSW object is called to disable the wake capabilities, maybe
 601         * the first argument is filled. The values of the other two agruments
 602         * are meaningless.
 603         */
 604        in_arg[0].type = ACPI_TYPE_INTEGER;
 605        in_arg[0].integer.value = enable;
 606        in_arg[1].type = ACPI_TYPE_INTEGER;
 607        in_arg[1].integer.value = sleep_state;
 608        in_arg[2].type = ACPI_TYPE_INTEGER;
 609        in_arg[2].integer.value = dev_state;
 610        status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
 611        if (ACPI_SUCCESS(status)) {
 612                return 0;
 613        } else if (status != AE_NOT_FOUND) {
 614                printk(KERN_ERR PREFIX "_DSW execution failed\n");
 615                dev->wakeup.flags.valid = 0;
 616                return -ENODEV;
 617        }
 618
 619        /* Execute _PSW */
 620        arg_list.count = 1;
 621        in_arg[0].integer.value = enable;
 622        status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
 623        if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
 624                printk(KERN_ERR PREFIX "_PSW execution failed\n");
 625                dev->wakeup.flags.valid = 0;
 626                return -ENODEV;
 627        }
 628
 629        return 0;
 630}
 631
 632/*
 633 * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
 634 * 1. Power on the power resources required for the wakeup device 
 635 * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 636 *    State Wake) for the device, if present
 637 */
 638int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
 639{
 640        struct acpi_power_resource_entry *entry;
 641        int err = 0;
 642
 643        if (!dev || !dev->wakeup.flags.valid)
 644                return -EINVAL;
 645
 646        mutex_lock(&acpi_device_lock);
 647
 648        if (dev->wakeup.prepare_count++)
 649                goto out;
 650
 651        list_for_each_entry(entry, &dev->wakeup.resources, node) {
 652                struct acpi_power_resource *resource = entry->resource;
 653
 654                mutex_lock(&resource->resource_lock);
 655
 656                if (!resource->wakeup_enabled) {
 657                        err = acpi_power_on_unlocked(resource);
 658                        if (!err)
 659                                resource->wakeup_enabled = true;
 660                }
 661
 662                mutex_unlock(&resource->resource_lock);
 663
 664                if (err) {
 665                        dev_err(&dev->dev,
 666                                "Cannot turn wakeup power resources on\n");
 667                        dev->wakeup.flags.valid = 0;
 668                        goto out;
 669                }
 670        }
 671        /*
 672         * Passing 3 as the third argument below means the device may be
 673         * put into arbitrary power state afterward.
 674         */
 675        err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
 676        if (err)
 677                dev->wakeup.prepare_count = 0;
 678
 679 out:
 680        mutex_unlock(&acpi_device_lock);
 681        return err;
 682}
 683
 684/*
 685 * Shutdown a wakeup device, counterpart of above method
 686 * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 687 *    State Wake) for the device, if present
 688 * 2. Shutdown down the power resources
 689 */
 690int acpi_disable_wakeup_device_power(struct acpi_device *dev)
 691{
 692        struct acpi_power_resource_entry *entry;
 693        int err = 0;
 694
 695        if (!dev || !dev->wakeup.flags.valid)
 696                return -EINVAL;
 697
 698        mutex_lock(&acpi_device_lock);
 699
 700        if (--dev->wakeup.prepare_count > 0)
 701                goto out;
 702
 703        /*
 704         * Executing the code below even if prepare_count is already zero when
 705         * the function is called may be useful, for example for initialisation.
 706         */
 707        if (dev->wakeup.prepare_count < 0)
 708                dev->wakeup.prepare_count = 0;
 709
 710        err = acpi_device_sleep_wake(dev, 0, 0, 0);
 711        if (err)
 712                goto out;
 713
 714        list_for_each_entry(entry, &dev->wakeup.resources, node) {
 715                struct acpi_power_resource *resource = entry->resource;
 716
 717                mutex_lock(&resource->resource_lock);
 718
 719                if (resource->wakeup_enabled) {
 720                        err = acpi_power_off_unlocked(resource);
 721                        if (!err)
 722                                resource->wakeup_enabled = false;
 723                }
 724
 725                mutex_unlock(&resource->resource_lock);
 726
 727                if (err) {
 728                        dev_err(&dev->dev,
 729                                "Cannot turn wakeup power resources off\n");
 730                        dev->wakeup.flags.valid = 0;
 731                        break;
 732                }
 733        }
 734
 735 out:
 736        mutex_unlock(&acpi_device_lock);
 737        return err;
 738}
 739
 740int acpi_power_get_inferred_state(struct acpi_device *device, int *state)
 741{
 742        int result = 0;
 743        int list_state = 0;
 744        int i = 0;
 745
 746        if (!device || !state)
 747                return -EINVAL;
 748
 749        /*
 750         * We know a device's inferred power state when all the resources
 751         * required for a given D-state are 'on'.
 752         */
 753        for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
 754                struct list_head *list = &device->power.states[i].resources;
 755
 756                if (list_empty(list))
 757                        continue;
 758
 759                result = acpi_power_get_list_state(list, &list_state);
 760                if (result)
 761                        return result;
 762
 763                if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
 764                        *state = i;
 765                        return 0;
 766                }
 767        }
 768
 769        *state = ACPI_STATE_D3;
 770        return 0;
 771}
 772
 773int acpi_power_on_resources(struct acpi_device *device, int state)
 774{
 775        if (!device || state < ACPI_STATE_D0 || state > ACPI_STATE_D3_HOT)
 776                return -EINVAL;
 777
 778        return acpi_power_on_list(&device->power.states[state].resources);
 779}
 780
 781int acpi_power_transition(struct acpi_device *device, int state)
 782{
 783        int result = 0;
 784
 785        if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
 786                return -EINVAL;
 787
 788        if (device->power.state == state || !device->flags.power_manageable)
 789                return 0;
 790
 791        if ((device->power.state < ACPI_STATE_D0)
 792            || (device->power.state > ACPI_STATE_D3_COLD))
 793                return -ENODEV;
 794
 795        /* TBD: Resources must be ordered. */
 796
 797        /*
 798         * First we reference all power resources required in the target list
 799         * (e.g. so the device doesn't lose power while transitioning).  Then,
 800         * we dereference all power resources used in the current list.
 801         */
 802        if (state < ACPI_STATE_D3_COLD)
 803                result = acpi_power_on_list(
 804                        &device->power.states[state].resources);
 805
 806        if (!result && device->power.state < ACPI_STATE_D3_COLD)
 807                acpi_power_off_list(
 808                        &device->power.states[device->power.state].resources);
 809
 810        /* We shouldn't change the state unless the above operations succeed. */
 811        device->power.state = result ? ACPI_STATE_UNKNOWN : state;
 812
 813        return result;
 814}
 815
 816static void acpi_release_power_resource(struct device *dev)
 817{
 818        struct acpi_device *device = to_acpi_device(dev);
 819        struct acpi_power_resource *resource;
 820
 821        resource = container_of(device, struct acpi_power_resource, device);
 822
 823        mutex_lock(&power_resource_list_lock);
 824        list_del(&resource->list_node);
 825        mutex_unlock(&power_resource_list_lock);
 826
 827        acpi_free_ids(device);
 828        kfree(resource);
 829}
 830
 831static ssize_t acpi_power_in_use_show(struct device *dev,
 832                                      struct device_attribute *attr,
 833                                      char *buf) {
 834        struct acpi_power_resource *resource;
 835
 836        resource = to_power_resource(to_acpi_device(dev));
 837        return sprintf(buf, "%u\n", !!resource->ref_count);
 838}
 839static DEVICE_ATTR(resource_in_use, 0444, acpi_power_in_use_show, NULL);
 840
 841static void acpi_power_sysfs_remove(struct acpi_device *device)
 842{
 843        device_remove_file(&device->dev, &dev_attr_resource_in_use);
 844}
 845
 846int acpi_add_power_resource(acpi_handle handle)
 847{
 848        struct acpi_power_resource *resource;
 849        struct acpi_device *device = NULL;
 850        union acpi_object acpi_object;
 851        struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
 852        acpi_status status;
 853        int state, result = -ENODEV;
 854
 855        acpi_bus_get_device(handle, &device);
 856        if (device)
 857                return 0;
 858
 859        resource = kzalloc(sizeof(*resource), GFP_KERNEL);
 860        if (!resource)
 861                return -ENOMEM;
 862
 863        device = &resource->device;
 864        acpi_init_device_object(device, handle, ACPI_BUS_TYPE_POWER,
 865                                ACPI_STA_DEFAULT);
 866        mutex_init(&resource->resource_lock);
 867        INIT_LIST_HEAD(&resource->dependent);
 868        resource->name = device->pnp.bus_id;
 869        strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
 870        strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
 871        device->power.state = ACPI_STATE_UNKNOWN;
 872
 873        /* Evalute the object to get the system level and resource order. */
 874        status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
 875        if (ACPI_FAILURE(status))
 876                goto err;
 877
 878        resource->system_level = acpi_object.power_resource.system_level;
 879        resource->order = acpi_object.power_resource.resource_order;
 880
 881        result = acpi_power_get_state(handle, &state);
 882        if (result)
 883                goto err;
 884
 885        printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
 886               acpi_device_bid(device), state ? "on" : "off");
 887
 888        device->flags.match_driver = true;
 889        result = acpi_device_add(device, acpi_release_power_resource);
 890        if (result)
 891                goto err;
 892
 893        if (!device_create_file(&device->dev, &dev_attr_resource_in_use))
 894                device->remove = acpi_power_sysfs_remove;
 895
 896        mutex_lock(&power_resource_list_lock);
 897        list_add(&resource->list_node, &acpi_power_resource_list);
 898        mutex_unlock(&power_resource_list_lock);
 899        acpi_device_add_finalize(device);
 900        return 0;
 901
 902 err:
 903        acpi_release_power_resource(&device->dev);
 904        return result;
 905}
 906
 907#ifdef CONFIG_ACPI_SLEEP
 908void acpi_resume_power_resources(void)
 909{
 910        struct acpi_power_resource *resource;
 911
 912        mutex_lock(&power_resource_list_lock);
 913
 914        list_for_each_entry(resource, &acpi_power_resource_list, list_node) {
 915                int result, state;
 916
 917                mutex_lock(&resource->resource_lock);
 918
 919                result = acpi_power_get_state(resource->device.handle, &state);
 920                if (result)
 921                        continue;
 922
 923                if (state == ACPI_POWER_RESOURCE_STATE_OFF
 924                    && resource->ref_count) {
 925                        dev_info(&resource->device.dev, "Turning ON\n");
 926                        __acpi_power_on(resource);
 927                } else if (state == ACPI_POWER_RESOURCE_STATE_ON
 928                    && !resource->ref_count) {
 929                        dev_info(&resource->device.dev, "Turning OFF\n");
 930                        __acpi_power_off(resource);
 931                }
 932
 933                mutex_unlock(&resource->resource_lock);
 934        }
 935
 936        mutex_unlock(&power_resource_list_lock);
 937}
 938#endif
 939
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