drivers/acpi/power.c

   1 /*
   2  * drivers/acpi/power.c - ACPI Power Resources management.
   3  *
   4  * Copyright (C) 2001 - 2015 Intel Corp.
   5  * Author: Andy Grover <andrew.grover@intel.com>
   6  * Author: Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   7  * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
   8  *
   9  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  10  *
  11  *  This program is free software; you can redistribute it and/or modify
  12  *  it under the terms of the GNU General Public License as published by
  13  *  the Free Software Foundation; either version 2 of the License, or (at
  14  *  your option) any later version.
  15  *
  16  *  This program is distributed in the hope that it will be useful, but
  17  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  18  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  *  General Public License for more details.
  20  *
  21  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  22  */
  23
  24 /*
  25  * ACPI power-managed devices may be controlled in two ways:
  26  * 1. via "Device Specific (D-State) Control"
  27  * 2. via "Power Resource Control".
  28  * The code below deals with ACPI Power Resources control.
  29  *
  30  * An ACPI "power resource object" represents a software controllable power
  31  * plane, clock plane, or other resource depended on by a device.
  32  *
  33  * A device may rely on multiple power resources, and a power resource
  34  * may be shared by multiple devices.
  35  */
  36
  37 #include <linux/kernel.h>
  38 #include <linux/module.h>
  39 #include <linux/init.h>
  40 #include <linux/types.h>
  41 #include <linux/slab.h>
  42 #include <linux/pm_runtime.h>
  43 #include <linux/sysfs.h>
  44 #include <linux/acpi.h>
  45 #include "sleep.h"
  46 #include "internal.h"
  47
  48 #define _COMPONENT                      ACPI_POWER_COMPONENT
  49 ACPI_MODULE_NAME("power");
  50 #define ACPI_POWER_CLASS                "power_resource"
  51 #define ACPI_POWER_DEVICE_NAME          "Power Resource"
  52 #define ACPI_POWER_FILE_INFO            "info"
  53 #define ACPI_POWER_FILE_STATUS          "state"
  54 #define ACPI_POWER_RESOURCE_STATE_OFF   0x00
  55 #define ACPI_POWER_RESOURCE_STATE_ON    0x01
  56 #define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF
  57
  58 struct acpi_power_resource {
  59         struct acpi_device device;
  60         struct list_head list_node;
  61         char *name;
  62         u32 system_level;
  63         u32 order;
  64         unsigned int ref_count;
  65         bool wakeup_enabled;
  66         struct mutex resource_lock;
  67 };
  68
  69 struct acpi_power_resource_entry {
  70         struct list_head node;
  71         struct acpi_power_resource *resource;
  72 };
  73
  74 static LIST_HEAD(acpi_power_resource_list);
  75 static DEFINE_MUTEX(power_resource_list_lock);
  76
  77 /* --------------------------------------------------------------------------
  78                              Power Resource Management
  79    -------------------------------------------------------------------------- */
  80
  81 static inline
  82 struct acpi_power_resource *to_power_resource(struct acpi_device *device)
  83 {
  84         return container_of(device, struct acpi_power_resource, device);
  85 }
  86
  87 static struct acpi_power_resource *acpi_power_get_context(acpi_handle handle)
  88 {
  89         struct acpi_device *device;
  90
  91         if (acpi_bus_get_device(handle, &device))
  92                 return NULL;
  93
  94         return to_power_resource(device);
  95 }
  96
  97 static int acpi_power_resources_list_add(acpi_handle handle,
  98                                          struct list_head *list)
  99 {
 100         struct acpi_power_resource *resource = acpi_power_get_context(handle);
 101         struct acpi_power_resource_entry *entry;
 102
 103         if (!resource || !list)
 104                 return -EINVAL;
 105
 106         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 107         if (!entry)
 108                 return -ENOMEM;
 109
 110         entry->resource = resource;
 111         if (!list_empty(list)) {
 112                 struct acpi_power_resource_entry *e;
 113
 114                 list_for_each_entry(e, list, node)
 115                         if (e->resource->order > resource->order) {
 116                                 list_add_tail(&entry->node, &e->node);
 117                                 return 0;
 118                         }
 119         }
 120         list_add_tail(&entry->node, list);
 121         return 0;
 122 }
 123
 124 void acpi_power_resources_list_free(struct list_head *list)
 125 {
 126         struct acpi_power_resource_entry *entry, *e;
 127
 128         list_for_each_entry_safe(entry, e, list, node) {
 129                 list_del(&entry->node);
 130                 kfree(entry);
 131         }
 132 }
 133
 134 static bool acpi_power_resource_is_dup(union acpi_object *package,
 135                                        unsigned int start, unsigned int i)
 136 {
 137         acpi_handle rhandle, dup;
 138         unsigned int j;
 139
 140         /* The caller is expected to check the package element types */
 141         rhandle = package->package.elements[i].reference.handle;
 142         for (j = start; j < i; j++) {
 143                 dup = package->package.elements[j].reference.handle;
 144                 if (dup == rhandle)
 145                         return true;
 146         }
 147
 148         return false;
 149 }
 150
 151 int acpi_extract_power_resources(union acpi_object *package, unsigned int start,
 152                                  struct list_head *list)
 153 {
 154         unsigned int i;
 155         int err = 0;
 156
 157         for (i = start; i < package->package.count; i++) {
 158                 union acpi_object *element = &package->package.elements[i];
 159                 acpi_handle rhandle;
 160
 161                 if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
 162                         err = -ENODATA;
 163                         break;
 164                 }
 165                 rhandle = element->reference.handle;
 166                 if (!rhandle) {
 167                         err = -ENODEV;
 168                         break;
 169                 }
 170
 171                 /* Some ACPI tables contain duplicate power resource references */
 172                 if (acpi_power_resource_is_dup(package, start, i))
 173                         continue;
 174
 175                 err = acpi_add_power_resource(rhandle);
 176                 if (err)
 177                         break;
 178
 179                 err = acpi_power_resources_list_add(rhandle, list);
 180                 if (err)
 181                         break;
 182         }
 183         if (err)
 184                 acpi_power_resources_list_free(list);
 185
 186         return err;
 187 }
 188
 189 static int acpi_power_get_state(acpi_handle handle, int *state)
 190 {
 191         acpi_status status = AE_OK;
 192         unsigned long long sta = 0;
 193         char node_name[5];
 194         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 195
 196
 197         if (!handle || !state)
 198                 return -EINVAL;
 199
 200         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 201         if (ACPI_FAILURE(status))
 202                 return -ENODEV;
 203
 204         *state = (sta & 0x01)?ACPI_POWER_RESOURCE_STATE_ON:
 205                               ACPI_POWER_RESOURCE_STATE_OFF;
 206
 207         acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 208
 209         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
 210                           node_name,
 211                                 *state ? "on" : "off"));
 212
 213         return 0;
 214 }
 215
 216 static int acpi_power_get_list_state(struct list_head *list, int *state)
 217 {
 218         struct acpi_power_resource_entry *entry;
 219         int cur_state;
 220
 221         if (!list || !state)
 222                 return -EINVAL;
 223
 224         /* The state of the list is 'on' IFF all resources are 'on'. */
 225         cur_state = 0;
 226         list_for_each_entry(entry, list, node) {
 227                 struct acpi_power_resource *resource = entry->resource;
 228                 acpi_handle handle = resource->device.handle;
 229                 int result;
 230
 231                 mutex_lock(&resource->resource_lock);
 232                 result = acpi_power_get_state(handle, &cur_state);
 233                 mutex_unlock(&resource->resource_lock);
 234                 if (result)
 235                         return result;
 236
 237                 if (cur_state != ACPI_POWER_RESOURCE_STATE_ON)
 238                         break;
 239         }
 240
 241         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
 242                           cur_state ? "on" : "off"));
 243
 244         *state = cur_state;
 245         return 0;
 246 }
 247
 248 static int __acpi_power_on(struct acpi_power_resource *resource)
 249 {
 250         acpi_status status = AE_OK;
 251
 252         status = acpi_evaluate_object(resource->device.handle, "_ON", NULL, NULL);
 253         if (ACPI_FAILURE(status))
 254                 return -ENODEV;
 255
 256         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned on\n",
 257                           resource->name));
 258
 259         return 0;
 260 }
 261
 262 static int acpi_power_on_unlocked(struct acpi_power_resource *resource)
 263 {
 264         int result = 0;
 265
 266         if (resource->ref_count++) {
 267                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 268                                   "Power resource [%s] already on\n",
 269                                   resource->name));
 270         } else {
 271                 result = __acpi_power_on(resource);
 272                 if (result)
 273                         resource->ref_count--;
 274         }
 275         return result;
 276 }
 277
 278 static int acpi_power_on(struct acpi_power_resource *resource)
 279 {
 280         int result;
 281
 282         mutex_lock(&resource->resource_lock);
 283         result = acpi_power_on_unlocked(resource);
 284         mutex_unlock(&resource->resource_lock);
 285         return result;
 286 }
 287
 288 static int __acpi_power_off(struct acpi_power_resource *resource)
 289 {
 290         acpi_status status;
 291
 292         status = acpi_evaluate_object(resource->device.handle, "_OFF",
 293                                       NULL, NULL);
 294         if (ACPI_FAILURE(status))
 295                 return -ENODEV;
 296
 297         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned off\n",
 298                           resource->name));
 299         return 0;
 300 }
 301
 302 static int acpi_power_off_unlocked(struct acpi_power_resource *resource)
 303 {
 304         int result = 0;
 305
 306         if (!resource->ref_count) {
 307                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 308                                   "Power resource [%s] already off\n",
 309                                   resource->name));
 310                 return 0;
 311         }
 312
 313         if (--resource->ref_count) {
 314                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 315                                   "Power resource [%s] still in use\n",
 316                                   resource->name));
 317         } else {
 318                 result = __acpi_power_off(resource);
 319                 if (result)
 320                         resource->ref_count++;
 321         }
 322         return result;
 323 }
 324
 325 static int acpi_power_off(struct acpi_power_resource *resource)
 326 {
 327         int result;
 328
 329         mutex_lock(&resource->resource_lock);
 330         result = acpi_power_off_unlocked(resource);
 331         mutex_unlock(&resource->resource_lock);
 332         return result;
 333 }
 334
 335 static int acpi_power_off_list(struct list_head *list)
 336 {
 337         struct acpi_power_resource_entry *entry;
 338         int result = 0;
 339
 340         list_for_each_entry_reverse(entry, list, node) {
 341                 result = acpi_power_off(entry->resource);
 342                 if (result)
 343                         goto err;
 344         }
 345         return 0;
 346
 347  err:
 348         list_for_each_entry_continue(entry, list, node)
 349                 acpi_power_on(entry->resource);
 350
 351         return result;
 352 }
 353
 354 static int acpi_power_on_list(struct list_head *list)
 355 {
 356         struct acpi_power_resource_entry *entry;
 357         int result = 0;
 358
 359         list_for_each_entry(entry, list, node) {
 360                 result = acpi_power_on(entry->resource);
 361                 if (result)
 362                         goto err;
 363         }
 364         return 0;
 365
 366  err:
 367         list_for_each_entry_continue_reverse(entry, list, node)
 368                 acpi_power_off(entry->resource);
 369
 370         return result;
 371 }
 372
 373 static struct attribute *attrs[] = {
 374         NULL,
 375 };
 376
 377 static const struct attribute_group attr_groups[] = {
 378         [ACPI_STATE_D0] = {
 379                 .name = "power_resources_D0",
 380                 .attrs = attrs,
 381         },
 382         [ACPI_STATE_D1] = {
 383                 .name = "power_resources_D1",
 384                 .attrs = attrs,
 385         },
 386         [ACPI_STATE_D2] = {
 387                 .name = "power_resources_D2",
 388                 .attrs = attrs,
 389         },
 390         [ACPI_STATE_D3_HOT] = {
 391                 .name = "power_resources_D3hot",
 392                 .attrs = attrs,
 393         },
 394 };
 395
 396 static const struct attribute_group wakeup_attr_group = {
 397         .name = "power_resources_wakeup",
 398         .attrs = attrs,
 399 };
 400
 401 static void acpi_power_hide_list(struct acpi_device *adev,
 402                                  struct list_head *resources,
 403                                  const struct attribute_group *attr_group)
 404 {
 405         struct acpi_power_resource_entry *entry;
 406
 407         if (list_empty(resources))
 408                 return;
 409
 410         list_for_each_entry_reverse(entry, resources, node) {
 411                 struct acpi_device *res_dev = &entry->resource->device;
 412
 413                 sysfs_remove_link_from_group(&adev->dev.kobj,
 414                                              attr_group->name,
 415                                              dev_name(&res_dev->dev));
 416         }
 417         sysfs_remove_group(&adev->dev.kobj, attr_group);
 418 }
 419
 420 static void acpi_power_expose_list(struct acpi_device *adev,
 421                                    struct list_head *resources,
 422                                    const struct attribute_group *attr_group)
 423 {
 424         struct acpi_power_resource_entry *entry;
 425         int ret;
 426
 427         if (list_empty(resources))
 428                 return;
 429
 430         ret = sysfs_create_group(&adev->dev.kobj, attr_group);
 431         if (ret)
 432                 return;
 433
 434         list_for_each_entry(entry, resources, node) {
 435                 struct acpi_device *res_dev = &entry->resource->device;
 436
 437                 ret = sysfs_add_link_to_group(&adev->dev.kobj,
 438                                               attr_group->name,
 439                                               &res_dev->dev.kobj,
 440                                               dev_name(&res_dev->dev));
 441                 if (ret) {
 442                         acpi_power_hide_list(adev, resources, attr_group);
 443                         break;
 444                 }
 445         }
 446 }
 447
 448 static void acpi_power_expose_hide(struct acpi_device *adev,
 449                                    struct list_head *resources,
 450                                    const struct attribute_group *attr_group,
 451                                    bool expose)
 452 {
 453         if (expose)
 454                 acpi_power_expose_list(adev, resources, attr_group);
 455         else
 456                 acpi_power_hide_list(adev, resources, attr_group);
 457 }
 458
 459 void acpi_power_add_remove_device(struct acpi_device *adev, bool add)
 460 {
 461         int state;
 462
 463         if (adev->wakeup.flags.valid)
 464                 acpi_power_expose_hide(adev, &adev->wakeup.resources,
 465                                        &wakeup_attr_group, add);
 466
 467         if (!adev->power.flags.power_resources)
 468                 return;
 469
 470         for (state = ACPI_STATE_D0; state <= ACPI_STATE_D3_HOT; state++)
 471                 acpi_power_expose_hide(adev,
 472                                        &adev->power.states[state].resources,
 473                                        &attr_groups[state], add);
 474 }
 475
 476 int acpi_power_wakeup_list_init(struct list_head *list, int *system_level_p)
 477 {
 478         struct acpi_power_resource_entry *entry;
 479         int system_level = 5;
 480
 481         list_for_each_entry(entry, list, node) {
 482                 struct acpi_power_resource *resource = entry->resource;
 483                 acpi_handle handle = resource->device.handle;
 484                 int result;
 485                 int state;
 486
 487                 mutex_lock(&resource->resource_lock);
 488
 489                 result = acpi_power_get_state(handle, &state);
 490                 if (result) {
 491                         mutex_unlock(&resource->resource_lock);
 492                         return result;
 493                 }
 494                 if (state == ACPI_POWER_RESOURCE_STATE_ON) {
 495                         resource->ref_count++;
 496                         resource->wakeup_enabled = true;
 497                 }
 498                 if (system_level > resource->system_level)
 499                         system_level = resource->system_level;
 500
 501                 mutex_unlock(&resource->resource_lock);
 502         }
 503         *system_level_p = system_level;
 504         return 0;
 505 }
 506
 507 /* --------------------------------------------------------------------------
 508                              Device Power Management
 509    -------------------------------------------------------------------------- */
 510
 511 /**
 512  * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
 513  *                          ACPI 3.0) _PSW (Power State Wake)
 514  * @dev: Device to handle.
 515  * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
 516  * @sleep_state: Target sleep state of the system.
 517  * @dev_state: Target power state of the device.
 518  *
 519  * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 520  * State Wake) for the device, if present.  On failure reset the device's
 521  * wakeup.flags.valid flag.
 522  *
 523  * RETURN VALUE:
 524  * 0 if either _DSW or _PSW has been successfully executed
 525  * 0 if neither _DSW nor _PSW has been found
 526  * -ENODEV if the execution of either _DSW or _PSW has failed
 527  */
 528 int acpi_device_sleep_wake(struct acpi_device *dev,
 529                            int enable, int sleep_state, int dev_state)
 530 {
 531         union acpi_object in_arg[3];
 532         struct acpi_object_list arg_list = { 3, in_arg };
 533         acpi_status status = AE_OK;
 534
 535         /*
 536          * Try to execute _DSW first.
 537          *
 538          * Three agruments are needed for the _DSW object:
 539          * Argument 0: enable/disable the wake capabilities
 540          * Argument 1: target system state
 541          * Argument 2: target device state
 542          * When _DSW object is called to disable the wake capabilities, maybe
 543          * the first argument is filled. The values of the other two agruments
 544          * are meaningless.
 545          */
 546         in_arg[0].type = ACPI_TYPE_INTEGER;
 547         in_arg[0].integer.value = enable;
 548         in_arg[1].type = ACPI_TYPE_INTEGER;
 549         in_arg[1].integer.value = sleep_state;
 550         in_arg[2].type = ACPI_TYPE_INTEGER;
 551         in_arg[2].integer.value = dev_state;
 552         status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
 553         if (ACPI_SUCCESS(status)) {
 554                 return 0;
 555         } else if (status != AE_NOT_FOUND) {
 556                 printk(KERN_ERR PREFIX "_DSW execution failed\n");
 557                 dev->wakeup.flags.valid = 0;
 558                 return -ENODEV;
 559         }
 560
 561         /* Execute _PSW */
 562         status = acpi_execute_simple_method(dev->handle, "_PSW", enable);
 563         if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
 564                 printk(KERN_ERR PREFIX "_PSW execution failed\n");
 565                 dev->wakeup.flags.valid = 0;
 566                 return -ENODEV;
 567         }
 568
 569         return 0;
 570 }
 571
 572 /*
 573  * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
 574  * 1. Power on the power resources required for the wakeup device
 575  * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 576  *    State Wake) for the device, if present
 577  */
 578 int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
 579 {
 580         struct acpi_power_resource_entry *entry;
 581         int err = 0;
 582
 583         if (!dev || !dev->wakeup.flags.valid)
 584                 return -EINVAL;
 585
 586         mutex_lock(&acpi_device_lock);
 587
 588         if (dev->wakeup.prepare_count++)
 589                 goto out;
 590
 591         list_for_each_entry(entry, &dev->wakeup.resources, node) {
 592                 struct acpi_power_resource *resource = entry->resource;
 593
 594                 mutex_lock(&resource->resource_lock);
 595
 596                 if (!resource->wakeup_enabled) {
 597                         err = acpi_power_on_unlocked(resource);
 598                         if (!err)
 599                                 resource->wakeup_enabled = true;
 600                 }
 601
 602                 mutex_unlock(&resource->resource_lock);
 603
 604                 if (err) {
 605                         dev_err(&dev->dev,
 606                                 "Cannot turn wakeup power resources on\n");
 607                         dev->wakeup.flags.valid = 0;
 608                         goto out;
 609                 }
 610         }
 611         /*
 612          * Passing 3 as the third argument below means the device may be
 613          * put into arbitrary power state afterward.
 614          */
 615         err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
 616         if (err)
 617                 dev->wakeup.prepare_count = 0;
 618
 619  out:
 620         mutex_unlock(&acpi_device_lock);
 621         return err;
 622 }
 623
 624 /*
 625  * Shutdown a wakeup device, counterpart of above method
 626  * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 627  *    State Wake) for the device, if present
 628  * 2. Shutdown down the power resources
 629  */
 630 int acpi_disable_wakeup_device_power(struct acpi_device *dev)
 631 {
 632         struct acpi_power_resource_entry *entry;
 633         int err = 0;
 634
 635         if (!dev || !dev->wakeup.flags.valid)
 636                 return -EINVAL;
 637
 638         mutex_lock(&acpi_device_lock);
 639
 640         if (--dev->wakeup.prepare_count > 0)
 641                 goto out;
 642
 643         /*
 644          * Executing the code below even if prepare_count is already zero when
 645          * the function is called may be useful, for example for initialisation.
 646          */
 647         if (dev->wakeup.prepare_count < 0)
 648                 dev->wakeup.prepare_count = 0;
 649
 650         err = acpi_device_sleep_wake(dev, 0, 0, 0);
 651         if (err)
 652                 goto out;
 653
 654         list_for_each_entry(entry, &dev->wakeup.resources, node) {
 655                 struct acpi_power_resource *resource = entry->resource;
 656
 657                 mutex_lock(&resource->resource_lock);
 658
 659                 if (resource->wakeup_enabled) {
 660                         err = acpi_power_off_unlocked(resource);
 661                         if (!err)
 662                                 resource->wakeup_enabled = false;
 663                 }
 664
 665                 mutex_unlock(&resource->resource_lock);
 666
 667                 if (err) {
 668                         dev_err(&dev->dev,
 669                                 "Cannot turn wakeup power resources off\n");
 670                         dev->wakeup.flags.valid = 0;
 671                         break;
 672                 }
 673         }
 674
 675  out:
 676         mutex_unlock(&acpi_device_lock);
 677         return err;
 678 }
 679
 680 int acpi_power_get_inferred_state(struct acpi_device *device, int *state)
 681 {
 682         int result = 0;
 683         int list_state = 0;
 684         int i = 0;
 685
 686         if (!device || !state)
 687                 return -EINVAL;
 688
 689         /*
 690          * We know a device's inferred power state when all the resources
 691          * required for a given D-state are 'on'.
 692          */
 693         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
 694                 struct list_head *list = &device->power.states[i].resources;
 695
 696                 if (list_empty(list))
 697                         continue;
 698
 699                 result = acpi_power_get_list_state(list, &list_state);
 700                 if (result)
 701                         return result;
 702
 703                 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
 704                         *state = i;
 705                         return 0;
 706                 }
 707         }
 708
 709         *state = device->power.states[ACPI_STATE_D3_COLD].flags.valid ?
 710                 ACPI_STATE_D3_COLD : ACPI_STATE_D3_HOT;
 711         return 0;
 712 }
 713
 714 int acpi_power_on_resources(struct acpi_device *device, int state)
 715 {
 716         if (!device || state < ACPI_STATE_D0 || state > ACPI_STATE_D3_HOT)
 717                 return -EINVAL;
 718
 719         return acpi_power_on_list(&device->power.states[state].resources);
 720 }
 721
 722 int acpi_power_transition(struct acpi_device *device, int state)
 723 {
 724         int result = 0;
 725
 726         if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
 727                 return -EINVAL;
 728
 729         if (device->power.state == state || !device->flags.power_manageable)
 730                 return 0;
 731
 732         if ((device->power.state < ACPI_STATE_D0)
 733             || (device->power.state > ACPI_STATE_D3_COLD))
 734                 return -ENODEV;
 735
 736         /*
 737          * First we reference all power resources required in the target list
 738          * (e.g. so the device doesn't lose power while transitioning).  Then,
 739          * we dereference all power resources used in the current list.
 740          */
 741         if (state < ACPI_STATE_D3_COLD)
 742                 result = acpi_power_on_list(
 743                         &device->power.states[state].resources);
 744
 745         if (!result && device->power.state < ACPI_STATE_D3_COLD)
 746                 acpi_power_off_list(
 747                         &device->power.states[device->power.state].resources);
 748
 749         /* We shouldn't change the state unless the above operations succeed. */
 750         device->power.state = result ? ACPI_STATE_UNKNOWN : state;
 751
 752         return result;
 753 }
 754
 755 static void acpi_release_power_resource(struct device *dev)
 756 {
 757         struct acpi_device *device = to_acpi_device(dev);
 758         struct acpi_power_resource *resource;
 759
 760         resource = container_of(device, struct acpi_power_resource, device);
 761
 762         mutex_lock(&power_resource_list_lock);
 763         list_del(&resource->list_node);
 764         mutex_unlock(&power_resource_list_lock);
 765
 766         acpi_free_pnp_ids(&device->pnp);
 767         kfree(resource);
 768 }
 769
 770 static ssize_t acpi_power_in_use_show(struct device *dev,
 771                                       struct device_attribute *attr,
 772                                       char *buf) {
 773         struct acpi_power_resource *resource;
 774
 775         resource = to_power_resource(to_acpi_device(dev));
 776         return sprintf(buf, "%u\n", !!resource->ref_count);
 777 }
 778 static DEVICE_ATTR(resource_in_use, 0444, acpi_power_in_use_show, NULL);
 779
 780 static void acpi_power_sysfs_remove(struct acpi_device *device)
 781 {
 782         device_remove_file(&device->dev, &dev_attr_resource_in_use);
 783 }
 784
 785 static void acpi_power_add_resource_to_list(struct acpi_power_resource *resource)
 786 {
 787         mutex_lock(&power_resource_list_lock);
 788
 789         if (!list_empty(&acpi_power_resource_list)) {
 790                 struct acpi_power_resource *r;
 791
 792                 list_for_each_entry(r, &acpi_power_resource_list, list_node)
 793                         if (r->order > resource->order) {
 794                                 list_add_tail(&resource->list_node, &r->list_node);
 795                                 goto out;
 796                         }
 797         }
 798         list_add_tail(&resource->list_node, &acpi_power_resource_list);
 799
 800  out:
 801         mutex_unlock(&power_resource_list_lock);
 802 }
 803
 804 int acpi_add_power_resource(acpi_handle handle)
 805 {
 806         struct acpi_power_resource *resource;
 807         struct acpi_device *device = NULL;
 808         union acpi_object acpi_object;
 809         struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
 810         acpi_status status;
 811         int state, result = -ENODEV;
 812
 813         acpi_bus_get_device(handle, &device);
 814         if (device)
 815                 return 0;
 816
 817         resource = kzalloc(sizeof(*resource), GFP_KERNEL);
 818         if (!resource)
 819                 return -ENOMEM;
 820
 821         device = &resource->device;
 822         acpi_init_device_object(device, handle, ACPI_BUS_TYPE_POWER,
 823                                 ACPI_STA_DEFAULT);
 824         mutex_init(&resource->resource_lock);
 825         INIT_LIST_HEAD(&resource->list_node);
 826         resource->name = device->pnp.bus_id;
 827         strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
 828         strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
 829         device->power.state = ACPI_STATE_UNKNOWN;
 830
 831         /* Evalute the object to get the system level and resource order. */
 832         status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
 833         if (ACPI_FAILURE(status))
 834                 goto err;
 835
 836         resource->system_level = acpi_object.power_resource.system_level;
 837         resource->order = acpi_object.power_resource.resource_order;
 838
 839         result = acpi_power_get_state(handle, &state);
 840         if (result)
 841                 goto err;
 842
 843         printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
 844                acpi_device_bid(device), state ? "on" : "off");
 845
 846         device->flags.match_driver = true;
 847         result = acpi_device_add(device, acpi_release_power_resource);
 848         if (result)
 849                 goto err;
 850
 851         if (!device_create_file(&device->dev, &dev_attr_resource_in_use))
 852                 device->remove = acpi_power_sysfs_remove;
 853
 854         acpi_power_add_resource_to_list(resource);
 855         acpi_device_add_finalize(device);
 856         return 0;
 857
 858  err:
 859         acpi_release_power_resource(&device->dev);
 860         return result;
 861 }
 862
 863 #ifdef CONFIG_ACPI_SLEEP
 864 void acpi_resume_power_resources(void)
 865 {
 866         struct acpi_power_resource *resource;
 867
 868         mutex_lock(&power_resource_list_lock);
 869
 870         list_for_each_entry(resource, &acpi_power_resource_list, list_node) {
 871                 int result, state;
 872
 873                 mutex_lock(&resource->resource_lock);
 874
 875                 result = acpi_power_get_state(resource->device.handle, &state);
 876                 if (result) {
 877                         mutex_unlock(&resource->resource_lock);
 878                         continue;
 879                 }
 880
 881                 if (state == ACPI_POWER_RESOURCE_STATE_OFF
 882                     && resource->ref_count) {
 883                         dev_info(&resource->device.dev, "Turning ON\n");
 884                         __acpi_power_on(resource);
 885                 }
 886
 887                 mutex_unlock(&resource->resource_lock);
 888         }
 889
 890         mutex_unlock(&power_resource_list_lock);
 891 }
 892
 893 void acpi_turn_off_unused_power_resources(void)
 894 {
 895         struct acpi_power_resource *resource;
 896
 897         mutex_lock(&power_resource_list_lock);
 898
 899         list_for_each_entry_reverse(resource, &acpi_power_resource_list, list_node) {
 900                 int result, state;
 901
 902                 mutex_lock(&resource->resource_lock);
 903
 904                 result = acpi_power_get_state(resource->device.handle, &state);
 905                 if (result) {
 906                         mutex_unlock(&resource->resource_lock);
 907                         continue;
 908                 }
 909
 910                 if (state == ACPI_POWER_RESOURCE_STATE_ON
 911                     && !resource->ref_count) {
 912                         dev_info(&resource->device.dev, "Turning OFF\n");
 913                         __acpi_power_off(resource);
 914                 }
 915
 916                 mutex_unlock(&resource->resource_lock);
 917         }
 918
 919         mutex_unlock(&power_resource_list_lock);
 920 }
 921 #endif