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