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 #define pr_fmt(fmt) "ACPI: PM: " fmt
  25
  26 #include <linux/dmi.h>
  27 #include <linux/kernel.h>
  28 #include <linux/module.h>
  29 #include <linux/init.h>
  30 #include <linux/types.h>
  31 #include <linux/slab.h>
  32 #include <linux/pm_runtime.h>
  33 #include <linux/sysfs.h>
  34 #include <linux/acpi.h>
  35 #include "sleep.h"
  36 #include "internal.h"
  37
  38 #define ACPI_POWER_CLASS                "power_resource"
  39 #define ACPI_POWER_DEVICE_NAME          "Power Resource"
  40 #define ACPI_POWER_RESOURCE_STATE_OFF   0x00
  41 #define ACPI_POWER_RESOURCE_STATE_ON    0x01
  42 #define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF
  43
  44 struct acpi_power_dependent_device {
  45         struct device *dev;
  46         struct list_head node;
  47 };
  48
  49 struct acpi_power_resource {
  50         struct acpi_device device;
  51         struct list_head list_node;
  52         u32 system_level;
  53         u32 order;
  54         unsigned int ref_count;
  55         u8 state;
  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 const char *resource_dev_name(struct acpi_power_resource *pr)
  73 {
  74         return dev_name(&pr->device.dev);
  75 }
  76
  77 static inline
  78 struct acpi_power_resource *to_power_resource(struct acpi_device *device)
  79 {
  80         return container_of(device, struct acpi_power_resource, device);
  81 }
  82
  83 static struct acpi_power_resource *acpi_power_get_context(acpi_handle handle)
  84 {
  85         struct acpi_device *device = acpi_fetch_acpi_dev(handle);
  86
  87         if (!device)
  88                 return NULL;
  89
  90         return to_power_resource(device);
  91 }
  92
  93 static int acpi_power_resources_list_add(acpi_handle handle,
  94                                          struct list_head *list)
  95 {
  96         struct acpi_power_resource *resource = acpi_power_get_context(handle);
  97         struct acpi_power_resource_entry *entry;
  98
  99         if (!resource || !list)
 100                 return -EINVAL;
 101
 102         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 103         if (!entry)
 104                 return -ENOMEM;
 105
 106         entry->resource = resource;
 107         if (!list_empty(list)) {
 108                 struct acpi_power_resource_entry *e;
 109
 110                 list_for_each_entry(e, list, node)
 111                         if (e->resource->order > resource->order) {
 112                                 list_add_tail(&entry->node, &e->node);
 113                                 return 0;
 114                         }
 115         }
 116         list_add_tail(&entry->node, list);
 117         return 0;
 118 }
 119
 120 void acpi_power_resources_list_free(struct list_head *list)
 121 {
 122         struct acpi_power_resource_entry *entry, *e;
 123
 124         list_for_each_entry_safe(entry, e, list, node) {
 125                 list_del(&entry->node);
 126                 kfree(entry);
 127         }
 128 }
 129
 130 static bool acpi_power_resource_is_dup(union acpi_object *package,
 131                                        unsigned int start, unsigned int i)
 132 {
 133         acpi_handle rhandle, dup;
 134         unsigned int j;
 135
 136         /* The caller is expected to check the package element types */
 137         rhandle = package->package.elements[i].reference.handle;
 138         for (j = start; j < i; j++) {
 139                 dup = package->package.elements[j].reference.handle;
 140                 if (dup == rhandle)
 141                         return true;
 142         }
 143
 144         return false;
 145 }
 146
 147 int acpi_extract_power_resources(union acpi_object *package, unsigned int start,
 148                                  struct list_head *list)
 149 {
 150         unsigned int i;
 151         int err = 0;
 152
 153         for (i = start; i < package->package.count; i++) {
 154                 union acpi_object *element = &package->package.elements[i];
 155                 struct acpi_device *rdev;
 156                 acpi_handle rhandle;
 157
 158                 if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
 159                         err = -ENODATA;
 160                         break;
 161                 }
 162                 rhandle = element->reference.handle;
 163                 if (!rhandle) {
 164                         err = -ENODEV;
 165                         break;
 166                 }
 167
 168                 /* Some ACPI tables contain duplicate power resource references */
 169                 if (acpi_power_resource_is_dup(package, start, i))
 170                         continue;
 171
 172                 rdev = acpi_add_power_resource(rhandle);
 173                 if (!rdev) {
 174                         err = -ENODEV;
 175                         break;
 176                 }
 177                 err = acpi_power_resources_list_add(rhandle, list);
 178                 if (err)
 179                         break;
 180         }
 181         if (err)
 182                 acpi_power_resources_list_free(list);
 183
 184         return err;
 185 }
 186
 187 static int __get_state(acpi_handle handle, u8 *state)
 188 {
 189         acpi_status status = AE_OK;
 190         unsigned long long sta = 0;
 191         u8 cur_state;
 192
 193         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 194         if (ACPI_FAILURE(status))
 195                 return -ENODEV;
 196
 197         cur_state = sta & ACPI_POWER_RESOURCE_STATE_ON;
 198
 199         acpi_handle_debug(handle, "Power resource is %s\n",
 200                           cur_state ? "on" : "off");
 201
 202         *state = cur_state;
 203         return 0;
 204 }
 205
 206 static int acpi_power_get_state(struct acpi_power_resource *resource, u8 *state)
 207 {
 208         if (resource->state == ACPI_POWER_RESOURCE_STATE_UNKNOWN) {
 209                 int ret;
 210
 211                 ret = __get_state(resource->device.handle, &resource->state);
 212                 if (ret)
 213                         return ret;
 214         }
 215
 216         *state = resource->state;
 217         return 0;
 218 }
 219
 220 static int acpi_power_get_list_state(struct list_head *list, u8 *state)
 221 {
 222         struct acpi_power_resource_entry *entry;
 223         u8 cur_state = ACPI_POWER_RESOURCE_STATE_OFF;
 224
 225         if (!list || !state)
 226                 return -EINVAL;
 227
 228         /* The state of the list is 'on' IFF all resources are 'on'. */
 229         list_for_each_entry(entry, list, node) {
 230                 struct acpi_power_resource *resource = entry->resource;
 231                 int result;
 232
 233                 mutex_lock(&resource->resource_lock);
 234                 result = acpi_power_get_state(resource, &cur_state);
 235                 mutex_unlock(&resource->resource_lock);
 236                 if (result)
 237                         return result;
 238
 239                 if (cur_state != ACPI_POWER_RESOURCE_STATE_ON)
 240                         break;
 241         }
 242
 243         pr_debug("Power resource list is %s\n", cur_state ? "on" : "off");
 244
 245         *state = cur_state;
 246         return 0;
 247 }
 248
 249 static int
 250 acpi_power_resource_add_dependent(struct acpi_power_resource *resource,
 251                                   struct device *dev)
 252 {
 253         struct acpi_power_dependent_device *dep;
 254         int ret = 0;
 255
 256         mutex_lock(&resource->resource_lock);
 257         list_for_each_entry(dep, &resource->dependents, node) {
 258                 /* Only add it once */
 259                 if (dep->dev == dev)
 260                         goto unlock;
 261         }
 262
 263         dep = kzalloc(sizeof(*dep), GFP_KERNEL);
 264         if (!dep) {
 265                 ret = -ENOMEM;
 266                 goto unlock;
 267         }
 268
 269         dep->dev = dev;
 270         list_add_tail(&dep->node, &resource->dependents);
 271         dev_dbg(dev, "added power dependency to [%s]\n",
 272                 resource_dev_name(resource));
 273
 274 unlock:
 275         mutex_unlock(&resource->resource_lock);
 276         return ret;
 277 }
 278
 279 static void
 280 acpi_power_resource_remove_dependent(struct acpi_power_resource *resource,
 281                                      struct device *dev)
 282 {
 283         struct acpi_power_dependent_device *dep;
 284
 285         mutex_lock(&resource->resource_lock);
 286         list_for_each_entry(dep, &resource->dependents, node) {
 287                 if (dep->dev == dev) {
 288                         list_del(&dep->node);
 289                         kfree(dep);
 290                         dev_dbg(dev, "removed power dependency to [%s]\n",
 291                                 resource_dev_name(resource));
 292                         break;
 293                 }
 294         }
 295         mutex_unlock(&resource->resource_lock);
 296 }
 297
 298 /**
 299  * acpi_device_power_add_dependent - Add dependent device of this ACPI device
 300  * @adev: ACPI device pointer
 301  * @dev: Dependent device
 302  *
 303  * If @adev has non-empty _PR0 the @dev is added as dependent device to all
 304  * power resources returned by it. This means that whenever these power
 305  * resources are turned _ON the dependent devices get runtime resumed. This
 306  * is needed for devices such as PCI to allow its driver to re-initialize
 307  * it after it went to D0uninitialized.
 308  *
 309  * If @adev does not have _PR0 this does nothing.
 310  *
 311  * Returns %0 in case of success and negative errno otherwise.
 312  */
 313 int acpi_device_power_add_dependent(struct acpi_device *adev,
 314                                     struct device *dev)
 315 {
 316         struct acpi_power_resource_entry *entry;
 317         struct list_head *resources;
 318         int ret;
 319
 320         if (!adev->flags.power_manageable)
 321                 return 0;
 322
 323         resources = &adev->power.states[ACPI_STATE_D0].resources;
 324         list_for_each_entry(entry, resources, node) {
 325                 ret = acpi_power_resource_add_dependent(entry->resource, dev);
 326                 if (ret)
 327                         goto err;
 328         }
 329
 330         return 0;
 331
 332 err:
 333         list_for_each_entry(entry, resources, node)
 334                 acpi_power_resource_remove_dependent(entry->resource, dev);
 335
 336         return ret;
 337 }
 338
 339 /**
 340  * acpi_device_power_remove_dependent - Remove dependent device
 341  * @adev: ACPI device pointer
 342  * @dev: Dependent device
 343  *
 344  * Does the opposite of acpi_device_power_add_dependent() and removes the
 345  * dependent device if it is found. Can be called to @adev that does not
 346  * have _PR0 as well.
 347  */
 348 void acpi_device_power_remove_dependent(struct acpi_device *adev,
 349                                         struct device *dev)
 350 {
 351         struct acpi_power_resource_entry *entry;
 352         struct list_head *resources;
 353
 354         if (!adev->flags.power_manageable)
 355                 return;
 356
 357         resources = &adev->power.states[ACPI_STATE_D0].resources;
 358         list_for_each_entry_reverse(entry, resources, node)
 359                 acpi_power_resource_remove_dependent(entry->resource, dev);
 360 }
 361
 362 static int __acpi_power_on(struct acpi_power_resource *resource)
 363 {
 364         acpi_handle handle = resource->device.handle;
 365         struct acpi_power_dependent_device *dep;
 366         acpi_status status = AE_OK;
 367
 368         status = acpi_evaluate_object(handle, "_ON", NULL, NULL);
 369         if (ACPI_FAILURE(status)) {
 370                 resource->state = ACPI_POWER_RESOURCE_STATE_UNKNOWN;
 371                 return -ENODEV;
 372         }
 373
 374         resource->state = ACPI_POWER_RESOURCE_STATE_ON;
 375
 376         acpi_handle_debug(handle, "Power resource turned on\n");
 377
 378         /*
 379          * If there are other dependents on this power resource we need to
 380          * resume them now so that their drivers can re-initialize the
 381          * hardware properly after it went back to D0.
 382          */
 383         if (list_empty(&resource->dependents) ||
 384             list_is_singular(&resource->dependents))
 385                 return 0;
 386
 387         list_for_each_entry(dep, &resource->dependents, node) {
 388                 dev_dbg(dep->dev, "runtime resuming because [%s] turned on\n",
 389                         resource_dev_name(resource));
 390                 pm_request_resume(dep->dev);
 391         }
 392
 393         return 0;
 394 }
 395
 396 static int acpi_power_on_unlocked(struct acpi_power_resource *resource)
 397 {
 398         int result = 0;
 399
 400         if (resource->ref_count++) {
 401                 acpi_handle_debug(resource->device.handle,
 402                                   "Power resource already on\n");
 403         } else {
 404                 result = __acpi_power_on(resource);
 405                 if (result)
 406                         resource->ref_count--;
 407         }
 408         return result;
 409 }
 410
 411 static int acpi_power_on(struct acpi_power_resource *resource)
 412 {
 413         int result;
 414
 415         mutex_lock(&resource->resource_lock);
 416         result = acpi_power_on_unlocked(resource);
 417         mutex_unlock(&resource->resource_lock);
 418         return result;
 419 }
 420
 421 static int __acpi_power_off(struct acpi_power_resource *resource)
 422 {
 423         acpi_handle handle = resource->device.handle;
 424         acpi_status status;
 425
 426         status = acpi_evaluate_object(handle, "_OFF", NULL, NULL);
 427         if (ACPI_FAILURE(status)) {
 428                 resource->state = ACPI_POWER_RESOURCE_STATE_UNKNOWN;
 429                 return -ENODEV;
 430         }
 431
 432         resource->state = ACPI_POWER_RESOURCE_STATE_OFF;
 433
 434         acpi_handle_debug(handle, "Power resource turned off\n");
 435
 436         return 0;
 437 }
 438
 439 static int acpi_power_off_unlocked(struct acpi_power_resource *resource)
 440 {
 441         int result = 0;
 442
 443         if (!resource->ref_count) {
 444                 acpi_handle_debug(resource->device.handle,
 445                                   "Power resource already off\n");
 446                 return 0;
 447         }
 448
 449         if (--resource->ref_count) {
 450                 acpi_handle_debug(resource->device.handle,
 451                                   "Power resource still in use\n");
 452         } else {
 453                 result = __acpi_power_off(resource);
 454                 if (result)
 455                         resource->ref_count++;
 456         }
 457         return result;
 458 }
 459
 460 static int acpi_power_off(struct acpi_power_resource *resource)
 461 {
 462         int result;
 463
 464         mutex_lock(&resource->resource_lock);
 465         result = acpi_power_off_unlocked(resource);
 466         mutex_unlock(&resource->resource_lock);
 467         return result;
 468 }
 469
 470 static int acpi_power_off_list(struct list_head *list)
 471 {
 472         struct acpi_power_resource_entry *entry;
 473         int result = 0;
 474
 475         list_for_each_entry_reverse(entry, list, node) {
 476                 result = acpi_power_off(entry->resource);
 477                 if (result)
 478                         goto err;
 479         }
 480         return 0;
 481
 482  err:
 483         list_for_each_entry_continue(entry, list, node)
 484                 acpi_power_on(entry->resource);
 485
 486         return result;
 487 }
 488
 489 static int acpi_power_on_list(struct list_head *list)
 490 {
 491         struct acpi_power_resource_entry *entry;
 492         int result = 0;
 493
 494         list_for_each_entry(entry, list, node) {
 495                 result = acpi_power_on(entry->resource);
 496                 if (result)
 497                         goto err;
 498         }
 499         return 0;
 500
 501  err:
 502         list_for_each_entry_continue_reverse(entry, list, node)
 503                 acpi_power_off(entry->resource);
 504
 505         return result;
 506 }
 507
 508 static struct attribute *attrs[] = {
 509         NULL,
 510 };
 511
 512 static const struct attribute_group attr_groups[] = {
 513         [ACPI_STATE_D0] = {
 514                 .name = "power_resources_D0",
 515                 .attrs = attrs,
 516         },
 517         [ACPI_STATE_D1] = {
 518                 .name = "power_resources_D1",
 519                 .attrs = attrs,
 520         },
 521         [ACPI_STATE_D2] = {
 522                 .name = "power_resources_D2",
 523                 .attrs = attrs,
 524         },
 525         [ACPI_STATE_D3_HOT] = {
 526                 .name = "power_resources_D3hot",
 527                 .attrs = attrs,
 528         },
 529 };
 530
 531 static const struct attribute_group wakeup_attr_group = {
 532         .name = "power_resources_wakeup",
 533         .attrs = attrs,
 534 };
 535
 536 static void acpi_power_hide_list(struct acpi_device *adev,
 537                                  struct list_head *resources,
 538                                  const struct attribute_group *attr_group)
 539 {
 540         struct acpi_power_resource_entry *entry;
 541
 542         if (list_empty(resources))
 543                 return;
 544
 545         list_for_each_entry_reverse(entry, resources, node) {
 546                 struct acpi_device *res_dev = &entry->resource->device;
 547
 548                 sysfs_remove_link_from_group(&adev->dev.kobj,
 549                                              attr_group->name,
 550                                              dev_name(&res_dev->dev));
 551         }
 552         sysfs_remove_group(&adev->dev.kobj, attr_group);
 553 }
 554
 555 static void acpi_power_expose_list(struct acpi_device *adev,
 556                                    struct list_head *resources,
 557                                    const struct attribute_group *attr_group)
 558 {
 559         struct acpi_power_resource_entry *entry;
 560         int ret;
 561
 562         if (list_empty(resources))
 563                 return;
 564
 565         ret = sysfs_create_group(&adev->dev.kobj, attr_group);
 566         if (ret)
 567                 return;
 568
 569         list_for_each_entry(entry, resources, node) {
 570                 struct acpi_device *res_dev = &entry->resource->device;
 571
 572                 ret = sysfs_add_link_to_group(&adev->dev.kobj,
 573                                               attr_group->name,
 574                                               &res_dev->dev.kobj,
 575                                               dev_name(&res_dev->dev));
 576                 if (ret) {
 577                         acpi_power_hide_list(adev, resources, attr_group);
 578                         break;
 579                 }
 580         }
 581 }
 582
 583 static void acpi_power_expose_hide(struct acpi_device *adev,
 584                                    struct list_head *resources,
 585                                    const struct attribute_group *attr_group,
 586                                    bool expose)
 587 {
 588         if (expose)
 589                 acpi_power_expose_list(adev, resources, attr_group);
 590         else
 591                 acpi_power_hide_list(adev, resources, attr_group);
 592 }
 593
 594 void acpi_power_add_remove_device(struct acpi_device *adev, bool add)
 595 {
 596         int state;
 597
 598         if (adev->wakeup.flags.valid)
 599                 acpi_power_expose_hide(adev, &adev->wakeup.resources,
 600                                        &wakeup_attr_group, add);
 601
 602         if (!adev->power.flags.power_resources)
 603                 return;
 604
 605         for (state = ACPI_STATE_D0; state <= ACPI_STATE_D3_HOT; state++)
 606                 acpi_power_expose_hide(adev,
 607                                        &adev->power.states[state].resources,
 608                                        &attr_groups[state], add);
 609 }
 610
 611 int acpi_power_wakeup_list_init(struct list_head *list, int *system_level_p)
 612 {
 613         struct acpi_power_resource_entry *entry;
 614         int system_level = 5;
 615
 616         list_for_each_entry(entry, list, node) {
 617                 struct acpi_power_resource *resource = entry->resource;
 618                 u8 state;
 619
 620                 mutex_lock(&resource->resource_lock);
 621
 622                 /*
 623                  * Make sure that the power resource state and its reference
 624                  * counter value are consistent with each other.
 625                  */
 626                 if (!resource->ref_count &&
 627                     !acpi_power_get_state(resource, &state) &&
 628                     state == ACPI_POWER_RESOURCE_STATE_ON)
 629                         __acpi_power_off(resource);
 630
 631                 if (system_level > resource->system_level)
 632                         system_level = resource->system_level;
 633
 634                 mutex_unlock(&resource->resource_lock);
 635         }
 636         *system_level_p = system_level;
 637         return 0;
 638 }
 639
 640 /* --------------------------------------------------------------------------
 641                              Device Power Management
 642    -------------------------------------------------------------------------- */
 643
 644 /**
 645  * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
 646  *                          ACPI 3.0) _PSW (Power State Wake)
 647  * @dev: Device to handle.
 648  * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
 649  * @sleep_state: Target sleep state of the system.
 650  * @dev_state: Target power state of the device.
 651  *
 652  * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 653  * State Wake) for the device, if present.  On failure reset the device's
 654  * wakeup.flags.valid flag.
 655  *
 656  * RETURN VALUE:
 657  * 0 if either _DSW or _PSW has been successfully executed
 658  * 0 if neither _DSW nor _PSW has been found
 659  * -ENODEV if the execution of either _DSW or _PSW has failed
 660  */
 661 int acpi_device_sleep_wake(struct acpi_device *dev,
 662                            int enable, int sleep_state, int dev_state)
 663 {
 664         union acpi_object in_arg[3];
 665         struct acpi_object_list arg_list = { 3, in_arg };
 666         acpi_status status = AE_OK;
 667
 668         /*
 669          * Try to execute _DSW first.
 670          *
 671          * Three arguments are needed for the _DSW object:
 672          * Argument 0: enable/disable the wake capabilities
 673          * Argument 1: target system state
 674          * Argument 2: target device state
 675          * When _DSW object is called to disable the wake capabilities, maybe
 676          * the first argument is filled. The values of the other two arguments
 677          * are meaningless.
 678          */
 679         in_arg[0].type = ACPI_TYPE_INTEGER;
 680         in_arg[0].integer.value = enable;
 681         in_arg[1].type = ACPI_TYPE_INTEGER;
 682         in_arg[1].integer.value = sleep_state;
 683         in_arg[2].type = ACPI_TYPE_INTEGER;
 684         in_arg[2].integer.value = dev_state;
 685         status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
 686         if (ACPI_SUCCESS(status)) {
 687                 return 0;
 688         } else if (status != AE_NOT_FOUND) {
 689                 acpi_handle_info(dev->handle, "_DSW execution failed\n");
 690                 dev->wakeup.flags.valid = 0;
 691                 return -ENODEV;
 692         }
 693
 694         /* Execute _PSW */
 695         status = acpi_execute_simple_method(dev->handle, "_PSW", enable);
 696         if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
 697                 acpi_handle_info(dev->handle, "_PSW execution failed\n");
 698                 dev->wakeup.flags.valid = 0;
 699                 return -ENODEV;
 700         }
 701
 702         return 0;
 703 }
 704
 705 /*
 706  * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
 707  * 1. Power on the power resources required for the wakeup device
 708  * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 709  *    State Wake) for the device, if present
 710  */
 711 int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
 712 {
 713         int err = 0;
 714
 715         if (!dev || !dev->wakeup.flags.valid)
 716                 return -EINVAL;
 717
 718         mutex_lock(&acpi_device_lock);
 719
 720         dev_dbg(&dev->dev, "Enabling wakeup power (count %d)\n",
 721                 dev->wakeup.prepare_count);
 722
 723         if (dev->wakeup.prepare_count++)
 724                 goto out;
 725
 726         err = acpi_power_on_list(&dev->wakeup.resources);
 727         if (err) {
 728                 dev_err(&dev->dev, "Cannot turn on wakeup power resources\n");
 729                 dev->wakeup.flags.valid = 0;
 730                 goto out;
 731         }
 732
 733         /*
 734          * Passing 3 as the third argument below means the device may be
 735          * put into arbitrary power state afterward.
 736          */
 737         err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
 738         if (err) {
 739                 acpi_power_off_list(&dev->wakeup.resources);
 740                 dev->wakeup.prepare_count = 0;
 741                 goto out;
 742         }
 743
 744         dev_dbg(&dev->dev, "Wakeup power enabled\n");
 745
 746  out:
 747         mutex_unlock(&acpi_device_lock);
 748         return err;
 749 }
 750
 751 /*
 752  * Shutdown a wakeup device, counterpart of above method
 753  * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 754  *    State Wake) for the device, if present
 755  * 2. Shutdown down the power resources
 756  */
 757 int acpi_disable_wakeup_device_power(struct acpi_device *dev)
 758 {
 759         struct acpi_power_resource_entry *entry;
 760         int err = 0;
 761
 762         if (!dev || !dev->wakeup.flags.valid)
 763                 return -EINVAL;
 764
 765         mutex_lock(&acpi_device_lock);
 766
 767         dev_dbg(&dev->dev, "Disabling wakeup power (count %d)\n",
 768                 dev->wakeup.prepare_count);
 769
 770         /* Do nothing if wakeup power has not been enabled for this device. */
 771         if (dev->wakeup.prepare_count <= 0)
 772                 goto out;
 773
 774         if (--dev->wakeup.prepare_count > 0)
 775                 goto out;
 776
 777         err = acpi_device_sleep_wake(dev, 0, 0, 0);
 778         if (err)
 779                 goto out;
 780
 781         /*
 782          * All of the power resources in the list need to be turned off even if
 783          * there are errors.
 784          */
 785         list_for_each_entry(entry, &dev->wakeup.resources, node) {
 786                 int ret;
 787
 788                 ret = acpi_power_off(entry->resource);
 789                 if (ret && !err)
 790                         err = ret;
 791         }
 792         if (err) {
 793                 dev_err(&dev->dev, "Cannot turn off wakeup power resources\n");
 794                 dev->wakeup.flags.valid = 0;
 795                 goto out;
 796         }
 797
 798         dev_dbg(&dev->dev, "Wakeup power disabled\n");
 799
 800  out:
 801         mutex_unlock(&acpi_device_lock);
 802         return err;
 803 }
 804
 805 int acpi_power_get_inferred_state(struct acpi_device *device, int *state)
 806 {
 807         u8 list_state = ACPI_POWER_RESOURCE_STATE_OFF;
 808         int result = 0;
 809         int i = 0;
 810
 811         if (!device || !state)
 812                 return -EINVAL;
 813
 814         /*
 815          * We know a device's inferred power state when all the resources
 816          * required for a given D-state are 'on'.
 817          */
 818         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
 819                 struct list_head *list = &device->power.states[i].resources;
 820
 821                 if (list_empty(list))
 822                         continue;
 823
 824                 result = acpi_power_get_list_state(list, &list_state);
 825                 if (result)
 826                         return result;
 827
 828                 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
 829                         *state = i;
 830                         return 0;
 831                 }
 832         }
 833
 834         *state = device->power.states[ACPI_STATE_D3_COLD].flags.valid ?
 835                 ACPI_STATE_D3_COLD : ACPI_STATE_D3_HOT;
 836         return 0;
 837 }
 838
 839 int acpi_power_on_resources(struct acpi_device *device, int state)
 840 {
 841         if (!device || state < ACPI_STATE_D0 || state > ACPI_STATE_D3_HOT)
 842                 return -EINVAL;
 843
 844         return acpi_power_on_list(&device->power.states[state].resources);
 845 }
 846
 847 int acpi_power_transition(struct acpi_device *device, int state)
 848 {
 849         int result = 0;
 850
 851         if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
 852                 return -EINVAL;
 853
 854         if (device->power.state == state || !device->flags.power_manageable)
 855                 return 0;
 856
 857         if ((device->power.state < ACPI_STATE_D0)
 858             || (device->power.state > ACPI_STATE_D3_COLD))
 859                 return -ENODEV;
 860
 861         /*
 862          * First we reference all power resources required in the target list
 863          * (e.g. so the device doesn't lose power while transitioning).  Then,
 864          * we dereference all power resources used in the current list.
 865          */
 866         if (state < ACPI_STATE_D3_COLD)
 867                 result = acpi_power_on_list(
 868                         &device->power.states[state].resources);
 869
 870         if (!result && device->power.state < ACPI_STATE_D3_COLD)
 871                 acpi_power_off_list(
 872                         &device->power.states[device->power.state].resources);
 873
 874         /* We shouldn't change the state unless the above operations succeed. */
 875         device->power.state = result ? ACPI_STATE_UNKNOWN : state;
 876
 877         return result;
 878 }
 879
 880 static void acpi_release_power_resource(struct device *dev)
 881 {
 882         struct acpi_device *device = to_acpi_device(dev);
 883         struct acpi_power_resource *resource;
 884
 885         resource = container_of(device, struct acpi_power_resource, device);
 886
 887         mutex_lock(&power_resource_list_lock);
 888         list_del(&resource->list_node);
 889         mutex_unlock(&power_resource_list_lock);
 890
 891         acpi_free_pnp_ids(&device->pnp);
 892         kfree(resource);
 893 }
 894
 895 static ssize_t resource_in_use_show(struct device *dev,
 896                                     struct device_attribute *attr,
 897                                     char *buf)
 898 {
 899         struct acpi_power_resource *resource;
 900
 901         resource = to_power_resource(to_acpi_device(dev));
 902         return sprintf(buf, "%u\n", !!resource->ref_count);
 903 }
 904 static DEVICE_ATTR_RO(resource_in_use);
 905
 906 static void acpi_power_sysfs_remove(struct acpi_device *device)
 907 {
 908         device_remove_file(&device->dev, &dev_attr_resource_in_use);
 909 }
 910
 911 static void acpi_power_add_resource_to_list(struct acpi_power_resource *resource)
 912 {
 913         mutex_lock(&power_resource_list_lock);
 914
 915         if (!list_empty(&acpi_power_resource_list)) {
 916                 struct acpi_power_resource *r;
 917
 918                 list_for_each_entry(r, &acpi_power_resource_list, list_node)
 919                         if (r->order > resource->order) {
 920                                 list_add_tail(&resource->list_node, &r->list_node);
 921                                 goto out;
 922                         }
 923         }
 924         list_add_tail(&resource->list_node, &acpi_power_resource_list);
 925
 926  out:
 927         mutex_unlock(&power_resource_list_lock);
 928 }
 929
 930 struct acpi_device *acpi_add_power_resource(acpi_handle handle)
 931 {
 932         struct acpi_device *device = acpi_fetch_acpi_dev(handle);
 933         struct acpi_power_resource *resource;
 934         union acpi_object acpi_object;
 935         struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
 936         acpi_status status;
 937         u8 state_dummy;
 938         int result;
 939
 940         if (device)
 941                 return device;
 942
 943         resource = kzalloc(sizeof(*resource), GFP_KERNEL);
 944         if (!resource)
 945                 return NULL;
 946
 947         device = &resource->device;
 948         acpi_init_device_object(device, handle, ACPI_BUS_TYPE_POWER,
 949                                 acpi_release_power_resource);
 950         mutex_init(&resource->resource_lock);
 951         INIT_LIST_HEAD(&resource->list_node);
 952         INIT_LIST_HEAD(&resource->dependents);
 953         strscpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
 954         strscpy(acpi_device_class(device), ACPI_POWER_CLASS);
 955         device->power.state = ACPI_STATE_UNKNOWN;
 956         device->flags.match_driver = true;
 957
 958         /* Evaluate the object to get the system level and resource order. */
 959         status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
 960         if (ACPI_FAILURE(status))
 961                 goto err;
 962
 963         resource->system_level = acpi_object.power_resource.system_level;
 964         resource->order = acpi_object.power_resource.resource_order;
 965         resource->state = ACPI_POWER_RESOURCE_STATE_UNKNOWN;
 966
 967         /* Get the initial state or just flip it on if that fails. */
 968         if (acpi_power_get_state(resource, &state_dummy))
 969                 __acpi_power_on(resource);
 970
 971         acpi_handle_info(handle, "New power resource\n");
 972
 973         result = acpi_tie_acpi_dev(device);
 974         if (result)
 975                 goto err;
 976
 977         result = acpi_device_add(device);
 978         if (result)
 979                 goto err;
 980
 981         if (!device_create_file(&device->dev, &dev_attr_resource_in_use))
 982                 device->remove = acpi_power_sysfs_remove;
 983
 984         acpi_power_add_resource_to_list(resource);
 985         acpi_device_add_finalize(device);
 986         return device;
 987
 988  err:
 989         acpi_release_power_resource(&device->dev);
 990         return NULL;
 991 }
 992
 993 #ifdef CONFIG_ACPI_SLEEP
 994 void acpi_resume_power_resources(void)
 995 {
 996         struct acpi_power_resource *resource;
 997
 998         mutex_lock(&power_resource_list_lock);
 999
1000         list_for_each_entry(resource, &acpi_power_resource_list, list_node) {
1001                 int result;
1002                 u8 state;
1003
1004                 mutex_lock(&resource->resource_lock);
1005
1006                 resource->state = ACPI_POWER_RESOURCE_STATE_UNKNOWN;
1007                 result = acpi_power_get_state(resource, &state);
1008                 if (result) {
1009                         mutex_unlock(&resource->resource_lock);
1010                         continue;
1011                 }
1012
1013                 if (state == ACPI_POWER_RESOURCE_STATE_OFF
1014                     && resource->ref_count) {
1015                         acpi_handle_debug(resource->device.handle, "Turning ON\n");
1016                         __acpi_power_on(resource);
1017                 }
1018
1019                 mutex_unlock(&resource->resource_lock);
1020         }
1021
1022         mutex_unlock(&power_resource_list_lock);
1023 }
1024 #endif
1025
1026 static const struct dmi_system_id dmi_leave_unused_power_resources_on[] = {
1027         {
1028                 /*
1029                  * The Toshiba Click Mini has a CPR3 power-resource which must
1030                  * be on for the touchscreen to work, but which is not in any
1031                  * _PR? lists. The other 2 affected power-resources are no-ops.
1032                  */
1033                 .matches = {
1034                         DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
1035                         DMI_MATCH(DMI_PRODUCT_NAME, "SATELLITE Click Mini L9W-B"),
1036                 },
1037         },
1038         {}
1039 };
1040
1041 /**
1042  * acpi_turn_off_unused_power_resources - Turn off power resources not in use.
1043  */
1044 void acpi_turn_off_unused_power_resources(void)
1045 {
1046         struct acpi_power_resource *resource;
1047
1048         if (dmi_check_system(dmi_leave_unused_power_resources_on))
1049                 return;
1050
1051         mutex_lock(&power_resource_list_lock);
1052
1053         list_for_each_entry_reverse(resource, &acpi_power_resource_list, list_node) {
1054                 mutex_lock(&resource->resource_lock);
1055
1056                 if (!resource->ref_count &&
1057                     resource->state == ACPI_POWER_RESOURCE_STATE_ON) {
1058                         acpi_handle_debug(resource->device.handle, "Turning OFF\n");
1059                         __acpi_power_off(resource);
1060                 }
1061
1062                 mutex_unlock(&resource->resource_lock);
1063         }
1064
1065         mutex_unlock(&power_resource_list_lock);
1066 }