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