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