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