drivers/acpi/power.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * drivers/acpi/power.c - ACPI Power Resources management.
   4  *
   5  * Copyright (C) 2001 - 2015 Intel Corp.
   6  * Author: Andy Grover <andrew.grover@intel.com>
   7  * Author: Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   8  * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
   9  */
  10
  11 /*
  12  * ACPI power-managed devices may be controlled in two ways:
  13  * 1. via "Device Specific (D-State) Control"
  14  * 2. via "Power Resource Control".
  15  * The code below deals with ACPI Power Resources control.
  16  *
  17  * An ACPI "power resource object" represents a software controllable power
  18  * plane, clock plane, or other resource depended on by a device.
  19  *
  20  * A device may rely on multiple power resources, and a power resource
  21  * may be shared by multiple devices.
  22  */
  23
  24 #include <linux/kernel.h>
  25 #include <linux/module.h>
  26 #include <linux/init.h>
  27 #include <linux/types.h>
  28 #include <linux/slab.h>
  29 #include <linux/pm_runtime.h>
  30 #include <linux/sysfs.h>
  31 #include <linux/acpi.h>
  32 #include "sleep.h"
  33 #include "internal.h"
  34
  35 #define _COMPONENT                      ACPI_POWER_COMPONENT
  36 ACPI_MODULE_NAME("power");
  37 #define ACPI_POWER_CLASS                "power_resource"
  38 #define ACPI_POWER_DEVICE_NAME          "Power Resource"
  39 #define ACPI_POWER_RESOURCE_STATE_OFF   0x00
  40 #define ACPI_POWER_RESOURCE_STATE_ON    0x01
  41 #define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF
  42
  43 struct acpi_power_dependent_device {
  44         struct device *dev;
  45         struct list_head node;
  46 };
  47
  48 struct acpi_power_resource {
  49         struct acpi_device device;
  50         struct list_head list_node;
  51         char *name;
  52         u32 system_level;
  53         u32 order;
  54         unsigned int ref_count;
  55         bool wakeup_enabled;
  56         struct mutex resource_lock;
  57         struct list_head dependents;
  58 };
  59
  60 struct acpi_power_resource_entry {
  61         struct list_head node;
  62         struct acpi_power_resource *resource;
  63 };
  64
  65 static LIST_HEAD(acpi_power_resource_list);
  66 static DEFINE_MUTEX(power_resource_list_lock);
  67
  68 /* --------------------------------------------------------------------------
  69                              Power Resource Management
  70    -------------------------------------------------------------------------- */
  71
  72 static inline
  73 struct acpi_power_resource *to_power_resource(struct acpi_device *device)
  74 {
  75         return container_of(device, struct acpi_power_resource, device);
  76 }
  77
  78 static struct acpi_power_resource *acpi_power_get_context(acpi_handle handle)
  79 {
  80         struct acpi_device *device;
  81
  82         if (acpi_bus_get_device(handle, &device))
  83                 return NULL;
  84
  85         return to_power_resource(device);
  86 }
  87
  88 static int acpi_power_resources_list_add(acpi_handle handle,
  89                                          struct list_head *list)
  90 {
  91         struct acpi_power_resource *resource = acpi_power_get_context(handle);
  92         struct acpi_power_resource_entry *entry;
  93
  94         if (!resource || !list)
  95                 return -EINVAL;
  96
  97         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
  98         if (!entry)
  99                 return -ENOMEM;
 100
 101         entry->resource = resource;
 102         if (!list_empty(list)) {
 103                 struct acpi_power_resource_entry *e;
 104
 105                 list_for_each_entry(e, list, node)
 106                         if (e->resource->order > resource->order) {
 107                                 list_add_tail(&entry->node, &e->node);
 108                                 return 0;
 109                         }
 110         }
 111         list_add_tail(&entry->node, list);
 112         return 0;
 113 }
 114
 115 void acpi_power_resources_list_free(struct list_head *list)
 116 {
 117         struct acpi_power_resource_entry *entry, *e;
 118
 119         list_for_each_entry_safe(entry, e, list, node) {
 120                 list_del(&entry->node);
 121                 kfree(entry);
 122         }
 123 }
 124
 125 static bool acpi_power_resource_is_dup(union acpi_object *package,
 126                                        unsigned int start, unsigned int i)
 127 {
 128         acpi_handle rhandle, dup;
 129         unsigned int j;
 130
 131         /* The caller is expected to check the package element types */
 132         rhandle = package->package.elements[i].reference.handle;
 133         for (j = start; j < i; j++) {
 134                 dup = package->package.elements[j].reference.handle;
 135                 if (dup == rhandle)
 136                         return true;
 137         }
 138
 139         return false;
 140 }
 141
 142 int acpi_extract_power_resources(union acpi_object *package, unsigned int start,
 143                                  struct list_head *list)
 144 {
 145         unsigned int i;
 146         int err = 0;
 147
 148         for (i = start; i < package->package.count; i++) {
 149                 union acpi_object *element = &package->package.elements[i];
 150                 acpi_handle rhandle;
 151
 152                 if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
 153                         err = -ENODATA;
 154                         break;
 155                 }
 156                 rhandle = element->reference.handle;
 157                 if (!rhandle) {
 158                         err = -ENODEV;
 159                         break;
 160                 }
 161
 162                 /* Some ACPI tables contain duplicate power resource references */
 163                 if (acpi_power_resource_is_dup(package, start, i))
 164                         continue;
 165
 166                 err = acpi_add_power_resource(rhandle);
 167                 if (err)
 168                         break;
 169
 170                 err = acpi_power_resources_list_add(rhandle, list);
 171                 if (err)
 172                         break;
 173         }
 174         if (err)
 175                 acpi_power_resources_list_free(list);
 176
 177         return err;
 178 }
 179
 180 static int acpi_power_get_state(acpi_handle handle, int *state)
 181 {
 182         acpi_status status = AE_OK;
 183         unsigned long long sta = 0;
 184         char node_name[5];
 185         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 186
 187
 188         if (!handle || !state)
 189                 return -EINVAL;
 190
 191         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 192         if (ACPI_FAILURE(status))
 193                 return -ENODEV;
 194
 195         *state = (sta & 0x01)?ACPI_POWER_RESOURCE_STATE_ON:
 196                               ACPI_POWER_RESOURCE_STATE_OFF;
 197
 198         acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 199
 200         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
 201                           node_name,
 202                                 *state ? "on" : "off"));
 203
 204         return 0;
 205 }
 206
 207 static int acpi_power_get_list_state(struct list_head *list, int *state)
 208 {
 209         struct acpi_power_resource_entry *entry;
 210         int cur_state;
 211
 212         if (!list || !state)
 213                 return -EINVAL;
 214
 215         /* The state of the list is 'on' IFF all resources are 'on'. */
 216         cur_state = 0;
 217         list_for_each_entry(entry, list, node) {
 218                 struct acpi_power_resource *resource = entry->resource;
 219                 acpi_handle handle = resource->device.handle;
 220                 int result;
 221
 222                 mutex_lock(&resource->resource_lock);
 223                 result = acpi_power_get_state(handle, &cur_state);
 224                 mutex_unlock(&resource->resource_lock);
 225                 if (result)
 226                         return result;
 227
 228                 if (cur_state != ACPI_POWER_RESOURCE_STATE_ON)
 229                         break;
 230         }
 231
 232         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
 233                           cur_state ? "on" : "off"));
 234
 235         *state = cur_state;
 236         return 0;
 237 }
 238
 239 static int
 240 acpi_power_resource_add_dependent(struct acpi_power_resource *resource,
 241                                   struct device *dev)
 242 {
 243         struct acpi_power_dependent_device *dep;
 244         int ret = 0;
 245
 246         mutex_lock(&resource->resource_lock);
 247         list_for_each_entry(dep, &resource->dependents, node) {
 248                 /* Only add it once */
 249                 if (dep->dev == dev)
 250                         goto unlock;
 251         }
 252
 253         dep = kzalloc(sizeof(*dep), GFP_KERNEL);
 254         if (!dep) {
 255                 ret = -ENOMEM;
 256                 goto unlock;
 257         }
 258
 259         dep->dev = dev;
 260         list_add_tail(&dep->node, &resource->dependents);
 261         dev_dbg(dev, "added power dependency to [%s]\n", resource->name);
 262
 263 unlock:
 264         mutex_unlock(&resource->resource_lock);
 265         return ret;
 266 }
 267
 268 static void
 269 acpi_power_resource_remove_dependent(struct acpi_power_resource *resource,
 270                                      struct device *dev)
 271 {
 272         struct acpi_power_dependent_device *dep;
 273
 274         mutex_lock(&resource->resource_lock);
 275         list_for_each_entry(dep, &resource->dependents, node) {
 276                 if (dep->dev == dev) {
 277                         list_del(&dep->node);
 278                         kfree(dep);
 279                         dev_dbg(dev, "removed power dependency to [%s]\n",
 280                                 resource->name);
 281                         break;
 282                 }
 283         }
 284         mutex_unlock(&resource->resource_lock);
 285 }
 286
 287 /**
 288  * acpi_device_power_add_dependent - Add dependent device of this ACPI device
 289  * @adev: ACPI device pointer
 290  * @dev: Dependent device
 291  *
 292  * If @adev has non-empty _PR0 the @dev is added as dependent device to all
 293  * power resources returned by it. This means that whenever these power
 294  * resources are turned _ON the dependent devices get runtime resumed. This
 295  * is needed for devices such as PCI to allow its driver to re-initialize
 296  * it after it went to D0uninitialized.
 297  *
 298  * If @adev does not have _PR0 this does nothing.
 299  *
 300  * Returns %0 in case of success and negative errno otherwise.
 301  */
 302 int acpi_device_power_add_dependent(struct acpi_device *adev,
 303                                     struct device *dev)
 304 {
 305         struct acpi_power_resource_entry *entry;
 306         struct list_head *resources;
 307         int ret;
 308
 309         if (!adev->flags.power_manageable)
 310                 return 0;
 311
 312         resources = &adev->power.states[ACPI_STATE_D0].resources;
 313         list_for_each_entry(entry, resources, node) {
 314                 ret = acpi_power_resource_add_dependent(entry->resource, dev);
 315                 if (ret)
 316                         goto err;
 317         }
 318
 319         return 0;
 320
 321 err:
 322         list_for_each_entry(entry, resources, node)
 323                 acpi_power_resource_remove_dependent(entry->resource, dev);
 324
 325         return ret;
 326 }
 327
 328 /**
 329  * acpi_device_power_remove_dependent - Remove dependent device
 330  * @adev: ACPI device pointer
 331  * @dev: Dependent device
 332  *
 333  * Does the opposite of acpi_device_power_add_dependent() and removes the
 334  * dependent device if it is found. Can be called to @adev that does not
 335  * have _PR0 as well.
 336  */
 337 void acpi_device_power_remove_dependent(struct acpi_device *adev,
 338                                         struct device *dev)
 339 {
 340         struct acpi_power_resource_entry *entry;
 341         struct list_head *resources;
 342
 343         if (!adev->flags.power_manageable)
 344                 return;
 345
 346         resources = &adev->power.states[ACPI_STATE_D0].resources;
 347         list_for_each_entry_reverse(entry, resources, node)
 348                 acpi_power_resource_remove_dependent(entry->resource, dev);
 349 }
 350
 351 static int __acpi_power_on(struct acpi_power_resource *resource)
 352 {
 353         struct acpi_power_dependent_device *dep;
 354         acpi_status status = AE_OK;
 355
 356         status = acpi_evaluate_object(resource->device.handle, "_ON", NULL, NULL);
 357         if (ACPI_FAILURE(status))
 358                 return -ENODEV;
 359
 360         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned on\n",
 361                           resource->name));
 362
 363         /*
 364          * If there are other dependents on this power resource we need to
 365          * resume them now so that their drivers can re-initialize the
 366          * hardware properly after it went back to D0.
 367          */
 368         if (list_empty(&resource->dependents) ||
 369             list_is_singular(&resource->dependents))
 370                 return 0;
 371
 372         list_for_each_entry(dep, &resource->dependents, node) {
 373                 dev_dbg(dep->dev, "runtime resuming because [%s] turned on\n",
 374                         resource->name);
 375                 pm_request_resume(dep->dev);
 376         }
 377
 378         return 0;
 379 }
 380
 381 static int acpi_power_on_unlocked(struct acpi_power_resource *resource)
 382 {
 383         int result = 0;
 384
 385         if (resource->ref_count++) {
 386                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 387                                   "Power resource [%s] already on\n",
 388                                   resource->name));
 389         } else {
 390                 result = __acpi_power_on(resource);
 391                 if (result)
 392                         resource->ref_count--;
 393         }
 394         return result;
 395 }
 396
 397 static int acpi_power_on(struct acpi_power_resource *resource)
 398 {
 399         int result;
 400
 401         mutex_lock(&resource->resource_lock);
 402         result = acpi_power_on_unlocked(resource);
 403         mutex_unlock(&resource->resource_lock);
 404         return result;
 405 }
 406
 407 static int __acpi_power_off(struct acpi_power_resource *resource)
 408 {
 409         acpi_status status;
 410
 411         status = acpi_evaluate_object(resource->device.handle, "_OFF",
 412                                       NULL, NULL);
 413         if (ACPI_FAILURE(status))
 414                 return -ENODEV;
 415
 416         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned off\n",
 417                           resource->name));
 418         return 0;
 419 }
 420
 421 static int acpi_power_off_unlocked(struct acpi_power_resource *resource)
 422 {
 423         int result = 0;
 424
 425         if (!resource->ref_count) {
 426                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 427                                   "Power resource [%s] already off\n",
 428                                   resource->name));
 429                 return 0;
 430         }
 431
 432         if (--resource->ref_count) {
 433                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 434                                   "Power resource [%s] still in use\n",
 435                                   resource->name));
 436         } else {
 437                 result = __acpi_power_off(resource);
 438                 if (result)
 439                         resource->ref_count++;
 440         }
 441         return result;
 442 }
 443
 444 static int acpi_power_off(struct acpi_power_resource *resource)
 445 {
 446         int result;
 447
 448         mutex_lock(&resource->resource_lock);
 449         result = acpi_power_off_unlocked(resource);
 450         mutex_unlock(&resource->resource_lock);
 451         return result;
 452 }
 453
 454 static int acpi_power_off_list(struct list_head *list)
 455 {
 456         struct acpi_power_resource_entry *entry;
 457         int result = 0;
 458
 459         list_for_each_entry_reverse(entry, list, node) {
 460                 result = acpi_power_off(entry->resource);
 461                 if (result)
 462                         goto err;
 463         }
 464         return 0;
 465
 466  err:
 467         list_for_each_entry_continue(entry, list, node)
 468                 acpi_power_on(entry->resource);
 469
 470         return result;
 471 }
 472
 473 static int acpi_power_on_list(struct list_head *list)
 474 {
 475         struct acpi_power_resource_entry *entry;
 476         int result = 0;
 477
 478         list_for_each_entry(entry, list, node) {
 479                 result = acpi_power_on(entry->resource);
 480                 if (result)
 481                         goto err;
 482         }
 483         return 0;
 484
 485  err:
 486         list_for_each_entry_continue_reverse(entry, list, node)
 487                 acpi_power_off(entry->resource);
 488
 489         return result;
 490 }
 491
 492 static struct attribute *attrs[] = {
 493         NULL,
 494 };
 495
 496 static const struct attribute_group attr_groups[] = {
 497         [ACPI_STATE_D0] = {
 498                 .name = "power_resources_D0",
 499                 .attrs = attrs,
 500         },
 501         [ACPI_STATE_D1] = {
 502                 .name = "power_resources_D1",
 503                 .attrs = attrs,
 504         },
 505         [ACPI_STATE_D2] = {
 506                 .name = "power_resources_D2",
 507                 .attrs = attrs,
 508         },
 509         [ACPI_STATE_D3_HOT] = {
 510                 .name = "power_resources_D3hot",
 511                 .attrs = attrs,
 512         },
 513 };
 514
 515 static const struct attribute_group wakeup_attr_group = {
 516         .name = "power_resources_wakeup",
 517         .attrs = attrs,
 518 };
 519
 520 static void acpi_power_hide_list(struct acpi_device *adev,
 521                                  struct list_head *resources,
 522                                  const struct attribute_group *attr_group)
 523 {
 524         struct acpi_power_resource_entry *entry;
 525
 526         if (list_empty(resources))
 527                 return;
 528
 529         list_for_each_entry_reverse(entry, resources, node) {
 530                 struct acpi_device *res_dev = &entry->resource->device;
 531
 532                 sysfs_remove_link_from_group(&adev->dev.kobj,
 533                                              attr_group->name,
 534                                              dev_name(&res_dev->dev));
 535         }
 536         sysfs_remove_group(&adev->dev.kobj, attr_group);
 537 }
 538
 539 static void acpi_power_expose_list(struct acpi_device *adev,
 540                                    struct list_head *resources,
 541                                    const struct attribute_group *attr_group)
 542 {
 543         struct acpi_power_resource_entry *entry;
 544         int ret;
 545
 546         if (list_empty(resources))
 547                 return;
 548
 549         ret = sysfs_create_group(&adev->dev.kobj, attr_group);
 550         if (ret)
 551                 return;
 552
 553         list_for_each_entry(entry, resources, node) {
 554                 struct acpi_device *res_dev = &entry->resource->device;
 555
 556                 ret = sysfs_add_link_to_group(&adev->dev.kobj,
 557                                               attr_group->name,
 558                                               &res_dev->dev.kobj,
 559                                               dev_name(&res_dev->dev));
 560                 if (ret) {
 561                         acpi_power_hide_list(adev, resources, attr_group);
 562                         break;
 563                 }
 564         }
 565 }
 566
 567 static void acpi_power_expose_hide(struct acpi_device *adev,
 568                                    struct list_head *resources,
 569                                    const struct attribute_group *attr_group,
 570                                    bool expose)
 571 {
 572         if (expose)
 573                 acpi_power_expose_list(adev, resources, attr_group);
 574         else
 575                 acpi_power_hide_list(adev, resources, attr_group);
 576 }
 577
 578 void acpi_power_add_remove_device(struct acpi_device *adev, bool add)
 579 {
 580         int state;
 581
 582         if (adev->wakeup.flags.valid)
 583                 acpi_power_expose_hide(adev, &adev->wakeup.resources,
 584                                        &wakeup_attr_group, add);
 585
 586         if (!adev->power.flags.power_resources)
 587                 return;
 588
 589         for (state = ACPI_STATE_D0; state <= ACPI_STATE_D3_HOT; state++)
 590                 acpi_power_expose_hide(adev,
 591                                        &adev->power.states[state].resources,
 592                                        &attr_groups[state], add);
 593 }
 594
 595 int acpi_power_wakeup_list_init(struct list_head *list, int *system_level_p)
 596 {
 597         struct acpi_power_resource_entry *entry;
 598         int system_level = 5;
 599
 600         list_for_each_entry(entry, list, node) {
 601                 struct acpi_power_resource *resource = entry->resource;
 602                 acpi_handle handle = resource->device.handle;
 603                 int result;
 604                 int state;
 605
 606                 mutex_lock(&resource->resource_lock);
 607
 608                 result = acpi_power_get_state(handle, &state);
 609                 if (result) {
 610                         mutex_unlock(&resource->resource_lock);
 611                         return result;
 612                 }
 613                 if (state == ACPI_POWER_RESOURCE_STATE_ON) {
 614                         resource->ref_count++;
 615                         resource->wakeup_enabled = true;
 616                 }
 617                 if (system_level > resource->system_level)
 618                         system_level = resource->system_level;
 619
 620                 mutex_unlock(&resource->resource_lock);
 621         }
 622         *system_level_p = system_level;
 623         return 0;
 624 }
 625
 626 /* --------------------------------------------------------------------------
 627                              Device Power Management
 628    -------------------------------------------------------------------------- */
 629
 630 /**
 631  * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
 632  *                          ACPI 3.0) _PSW (Power State Wake)
 633  * @dev: Device to handle.
 634  * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
 635  * @sleep_state: Target sleep state of the system.
 636  * @dev_state: Target power state of the device.
 637  *
 638  * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 639  * State Wake) for the device, if present.  On failure reset the device's
 640  * wakeup.flags.valid flag.
 641  *
 642  * RETURN VALUE:
 643  * 0 if either _DSW or _PSW has been successfully executed
 644  * 0 if neither _DSW nor _PSW has been found
 645  * -ENODEV if the execution of either _DSW or _PSW has failed
 646  */
 647 int acpi_device_sleep_wake(struct acpi_device *dev,
 648                            int enable, int sleep_state, int dev_state)
 649 {
 650         union acpi_object in_arg[3];
 651         struct acpi_object_list arg_list = { 3, in_arg };
 652         acpi_status status = AE_OK;
 653
 654         /*
 655          * Try to execute _DSW first.
 656          *
 657          * Three arguments are needed for the _DSW object:
 658          * Argument 0: enable/disable the wake capabilities
 659          * Argument 1: target system state
 660          * Argument 2: target device state
 661          * When _DSW object is called to disable the wake capabilities, maybe
 662          * the first argument is filled. The values of the other two arguments
 663          * are meaningless.
 664          */
 665         in_arg[0].type = ACPI_TYPE_INTEGER;
 666         in_arg[0].integer.value = enable;
 667         in_arg[1].type = ACPI_TYPE_INTEGER;
 668         in_arg[1].integer.value = sleep_state;
 669         in_arg[2].type = ACPI_TYPE_INTEGER;
 670         in_arg[2].integer.value = dev_state;
 671         status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
 672         if (ACPI_SUCCESS(status)) {
 673                 return 0;
 674         } else if (status != AE_NOT_FOUND) {
 675                 printk(KERN_ERR PREFIX "_DSW execution failed\n");
 676                 dev->wakeup.flags.valid = 0;
 677                 return -ENODEV;
 678         }
 679
 680         /* Execute _PSW */
 681         status = acpi_execute_simple_method(dev->handle, "_PSW", enable);
 682         if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
 683                 printk(KERN_ERR PREFIX "_PSW execution failed\n");
 684                 dev->wakeup.flags.valid = 0;
 685                 return -ENODEV;
 686         }
 687
 688         return 0;
 689 }
 690
 691 /*
 692  * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
 693  * 1. Power on the power resources required for the wakeup device
 694  * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 695  *    State Wake) for the device, if present
 696  */
 697 int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
 698 {
 699         struct acpi_power_resource_entry *entry;
 700         int err = 0;
 701
 702         if (!dev || !dev->wakeup.flags.valid)
 703                 return -EINVAL;
 704
 705         mutex_lock(&acpi_device_lock);
 706
 707         if (dev->wakeup.prepare_count++)
 708                 goto out;
 709
 710         list_for_each_entry(entry, &dev->wakeup.resources, node) {
 711                 struct acpi_power_resource *resource = entry->resource;
 712
 713                 mutex_lock(&resource->resource_lock);
 714
 715                 if (!resource->wakeup_enabled) {
 716                         err = acpi_power_on_unlocked(resource);
 717                         if (!err)
 718                                 resource->wakeup_enabled = true;
 719                 }
 720
 721                 mutex_unlock(&resource->resource_lock);
 722
 723                 if (err) {
 724                         dev_err(&dev->dev,
 725                                 "Cannot turn wakeup power resources on\n");
 726                         dev->wakeup.flags.valid = 0;
 727                         goto out;
 728                 }
 729         }
 730         /*
 731          * Passing 3 as the third argument below means the device may be
 732          * put into arbitrary power state afterward.
 733          */
 734         err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
 735         if (err)
 736                 dev->wakeup.prepare_count = 0;
 737
 738  out:
 739         mutex_unlock(&acpi_device_lock);
 740         return err;
 741 }
 742
 743 /*
 744  * Shutdown a wakeup device, counterpart of above method
 745  * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 746  *    State Wake) for the device, if present
 747  * 2. Shutdown down the power resources
 748  */
 749 int acpi_disable_wakeup_device_power(struct acpi_device *dev)
 750 {
 751         struct acpi_power_resource_entry *entry;
 752         int err = 0;
 753
 754         if (!dev || !dev->wakeup.flags.valid)
 755                 return -EINVAL;
 756
 757         mutex_lock(&acpi_device_lock);
 758
 759         if (--dev->wakeup.prepare_count > 0)
 760                 goto out;
 761
 762         /*
 763          * Executing the code below even if prepare_count is already zero when
 764          * the function is called may be useful, for example for initialisation.
 765          */
 766         if (dev->wakeup.prepare_count < 0)
 767                 dev->wakeup.prepare_count = 0;
 768
 769         err = acpi_device_sleep_wake(dev, 0, 0, 0);
 770         if (err)
 771                 goto out;
 772
 773         list_for_each_entry(entry, &dev->wakeup.resources, node) {
 774                 struct acpi_power_resource *resource = entry->resource;
 775
 776                 mutex_lock(&resource->resource_lock);
 777
 778                 if (resource->wakeup_enabled) {
 779                         err = acpi_power_off_unlocked(resource);
 780                         if (!err)
 781                                 resource->wakeup_enabled = false;
 782                 }
 783
 784                 mutex_unlock(&resource->resource_lock);
 785
 786                 if (err) {
 787                         dev_err(&dev->dev,
 788                                 "Cannot turn wakeup power resources off\n");
 789                         dev->wakeup.flags.valid = 0;
 790                         break;
 791                 }
 792         }
 793
 794  out:
 795         mutex_unlock(&acpi_device_lock);
 796         return err;
 797 }
 798
 799 int acpi_power_get_inferred_state(struct acpi_device *device, int *state)
 800 {
 801         int result = 0;
 802         int list_state = 0;
 803         int i = 0;
 804
 805         if (!device || !state)
 806                 return -EINVAL;
 807
 808         /*
 809          * We know a device's inferred power state when all the resources
 810          * required for a given D-state are 'on'.
 811          */
 812         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
 813                 struct list_head *list = &device->power.states[i].resources;
 814
 815                 if (list_empty(list))
 816                         continue;
 817
 818                 result = acpi_power_get_list_state(list, &list_state);
 819                 if (result)
 820                         return result;
 821
 822                 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
 823                         *state = i;
 824                         return 0;
 825                 }
 826         }
 827
 828         *state = device->power.states[ACPI_STATE_D3_COLD].flags.valid ?
 829                 ACPI_STATE_D3_COLD : ACPI_STATE_D3_HOT;
 830         return 0;
 831 }
 832
 833 int acpi_power_on_resources(struct acpi_device *device, int state)
 834 {
 835         if (!device || state < ACPI_STATE_D0 || state > ACPI_STATE_D3_HOT)
 836                 return -EINVAL;
 837
 838         return acpi_power_on_list(&device->power.states[state].resources);
 839 }
 840
 841 int acpi_power_transition(struct acpi_device *device, int state)
 842 {
 843         int result = 0;
 844
 845         if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
 846                 return -EINVAL;
 847
 848         if (device->power.state == state || !device->flags.power_manageable)
 849                 return 0;
 850
 851         if ((device->power.state < ACPI_STATE_D0)
 852             || (device->power.state > ACPI_STATE_D3_COLD))
 853                 return -ENODEV;
 854
 855         /*
 856          * First we reference all power resources required in the target list
 857          * (e.g. so the device doesn't lose power while transitioning).  Then,
 858          * we dereference all power resources used in the current list.
 859          */
 860         if (state < ACPI_STATE_D3_COLD)
 861                 result = acpi_power_on_list(
 862                         &device->power.states[state].resources);
 863
 864         if (!result && device->power.state < ACPI_STATE_D3_COLD)
 865                 acpi_power_off_list(
 866                         &device->power.states[device->power.state].resources);
 867
 868         /* We shouldn't change the state unless the above operations succeed. */
 869         device->power.state = result ? ACPI_STATE_UNKNOWN : state;
 870
 871         return result;
 872 }
 873
 874 static void acpi_release_power_resource(struct device *dev)
 875 {
 876         struct acpi_device *device = to_acpi_device(dev);
 877         struct acpi_power_resource *resource;
 878
 879         resource = container_of(device, struct acpi_power_resource, device);
 880
 881         mutex_lock(&power_resource_list_lock);
 882         list_del(&resource->list_node);
 883         mutex_unlock(&power_resource_list_lock);
 884
 885         acpi_free_pnp_ids(&device->pnp);
 886         kfree(resource);
 887 }
 888
 889 static ssize_t acpi_power_in_use_show(struct device *dev,
 890                                       struct device_attribute *attr,
 891                                       char *buf) {
 892         struct acpi_power_resource *resource;
 893
 894         resource = to_power_resource(to_acpi_device(dev));
 895         return sprintf(buf, "%u\n", !!resource->ref_count);
 896 }
 897 static DEVICE_ATTR(resource_in_use, 0444, acpi_power_in_use_show, NULL);
 898
 899 static void acpi_power_sysfs_remove(struct acpi_device *device)
 900 {
 901         device_remove_file(&device->dev, &dev_attr_resource_in_use);
 902 }
 903
 904 static void acpi_power_add_resource_to_list(struct acpi_power_resource *resource)
 905 {
 906         mutex_lock(&power_resource_list_lock);
 907
 908         if (!list_empty(&acpi_power_resource_list)) {
 909                 struct acpi_power_resource *r;
 910
 911                 list_for_each_entry(r, &acpi_power_resource_list, list_node)
 912                         if (r->order > resource->order) {
 913                                 list_add_tail(&resource->list_node, &r->list_node);
 914                                 goto out;
 915                         }
 916         }
 917         list_add_tail(&resource->list_node, &acpi_power_resource_list);
 918
 919  out:
 920         mutex_unlock(&power_resource_list_lock);
 921 }
 922
 923 int acpi_add_power_resource(acpi_handle handle)
 924 {
 925         struct acpi_power_resource *resource;
 926         struct acpi_device *device = NULL;
 927         union acpi_object acpi_object;
 928         struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
 929         acpi_status status;
 930         int state, result = -ENODEV;
 931
 932         acpi_bus_get_device(handle, &device);
 933         if (device)
 934                 return 0;
 935
 936         resource = kzalloc(sizeof(*resource), GFP_KERNEL);
 937         if (!resource)
 938                 return -ENOMEM;
 939
 940         device = &resource->device;
 941         acpi_init_device_object(device, handle, ACPI_BUS_TYPE_POWER,
 942                                 ACPI_STA_DEFAULT, NULL);
 943         mutex_init(&resource->resource_lock);
 944         INIT_LIST_HEAD(&resource->list_node);
 945         INIT_LIST_HEAD(&resource->dependents);
 946         resource->name = device->pnp.bus_id;
 947         strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
 948         strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
 949         device->power.state = ACPI_STATE_UNKNOWN;
 950
 951         /* Evalute the object to get the system level and resource order. */
 952         status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
 953         if (ACPI_FAILURE(status))
 954                 goto err;
 955
 956         resource->system_level = acpi_object.power_resource.system_level;
 957         resource->order = acpi_object.power_resource.resource_order;
 958
 959         result = acpi_power_get_state(handle, &state);
 960         if (result)
 961                 goto err;
 962
 963         printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
 964                acpi_device_bid(device), state ? "on" : "off");
 965
 966         device->flags.match_driver = true;
 967         result = acpi_device_add(device, acpi_release_power_resource);
 968         if (result)
 969                 goto err;
 970
 971         if (!device_create_file(&device->dev, &dev_attr_resource_in_use))
 972                 device->remove = acpi_power_sysfs_remove;
 973
 974         acpi_power_add_resource_to_list(resource);
 975         acpi_device_add_finalize(device);
 976         return 0;
 977
 978  err:
 979         acpi_release_power_resource(&device->dev);
 980         return result;
 981 }
 982
 983 #ifdef CONFIG_ACPI_SLEEP
 984 void acpi_resume_power_resources(void)
 985 {
 986         struct acpi_power_resource *resource;
 987
 988         mutex_lock(&power_resource_list_lock);
 989
 990         list_for_each_entry(resource, &acpi_power_resource_list, list_node) {
 991                 int result, state;
 992
 993                 mutex_lock(&resource->resource_lock);
 994
 995                 result = acpi_power_get_state(resource->device.handle, &state);
 996                 if (result) {
 997                         mutex_unlock(&resource->resource_lock);
 998                         continue;
 999                 }
1000
1001                 if (state == ACPI_POWER_RESOURCE_STATE_OFF
1002                     && resource->ref_count) {
1003                         dev_info(&resource->device.dev, "Turning ON\n");
1004                         __acpi_power_on(resource);
1005                 }
1006
1007                 mutex_unlock(&resource->resource_lock);
1008         }
1009
1010         mutex_unlock(&power_resource_list_lock);
1011 }
1012
1013 void acpi_turn_off_unused_power_resources(void)
1014 {
1015         struct acpi_power_resource *resource;
1016
1017         mutex_lock(&power_resource_list_lock);
1018
1019         list_for_each_entry_reverse(resource, &acpi_power_resource_list, list_node) {
1020                 int result, state;
1021
1022                 mutex_lock(&resource->resource_lock);
1023
1024                 result = acpi_power_get_state(resource->device.handle, &state);
1025                 if (result) {
1026                         mutex_unlock(&resource->resource_lock);
1027                         continue;
1028                 }
1029
1030                 if (state == ACPI_POWER_RESOURCE_STATE_ON
1031                     && !resource->ref_count) {
1032                         dev_info(&resource->device.dev, "Turning OFF\n");
1033                         __acpi_power_off(resource);
1034                 }
1035
1036                 mutex_unlock(&resource->resource_lock);
1037         }
1038
1039         mutex_unlock(&power_resource_list_lock);
1040 }
1041 #endif