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_dependent_device {
  63         struct list_head node;
  64         struct acpi_device *adev;
  65         struct work_struct work;
  66 };
  67
  68 struct acpi_power_resource {
  69         struct acpi_device device;
  70         struct list_head list_node;
  71         struct list_head dependent;
  72         char *name;
  73         u32 system_level;
  74         u32 order;
  75         unsigned int ref_count;
  76         bool wakeup_enabled;
  77         struct mutex resource_lock;
  78 };
  79
  80 struct acpi_power_resource_entry {
  81         struct list_head node;
  82         struct acpi_power_resource *resource;
  83 };
  84
  85 static LIST_HEAD(acpi_power_resource_list);
  86 static DEFINE_MUTEX(power_resource_list_lock);
  87
  88 /* --------------------------------------------------------------------------
  89                              Power Resource Management
  90    -------------------------------------------------------------------------- */
  91
  92 static inline
  93 struct acpi_power_resource *to_power_resource(struct acpi_device *device)
  94 {
  95         return container_of(device, struct acpi_power_resource, device);
  96 }
  97
  98 static struct acpi_power_resource *acpi_power_get_context(acpi_handle handle)
  99 {
 100         struct acpi_device *device;
 101
 102         if (acpi_bus_get_device(handle, &device))
 103                 return NULL;
 104
 105         return to_power_resource(device);
 106 }
 107
 108 static int acpi_power_resources_list_add(acpi_handle handle,
 109                                          struct list_head *list)
 110 {
 111         struct acpi_power_resource *resource = acpi_power_get_context(handle);
 112         struct acpi_power_resource_entry *entry;
 113
 114         if (!resource || !list)
 115                 return -EINVAL;
 116
 117         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 118         if (!entry)
 119                 return -ENOMEM;
 120
 121         entry->resource = resource;
 122         if (!list_empty(list)) {
 123                 struct acpi_power_resource_entry *e;
 124
 125                 list_for_each_entry(e, list, node)
 126                         if (e->resource->order > resource->order) {
 127                                 list_add_tail(&entry->node, &e->node);
 128                                 return 0;
 129                         }
 130         }
 131         list_add_tail(&entry->node, list);
 132         return 0;
 133 }
 134
 135 void acpi_power_resources_list_free(struct list_head *list)
 136 {
 137         struct acpi_power_resource_entry *entry, *e;
 138
 139         list_for_each_entry_safe(entry, e, list, node) {
 140                 list_del(&entry->node);
 141                 kfree(entry);
 142         }
 143 }
 144
 145 int acpi_extract_power_resources(union acpi_object *package, unsigned int start,
 146                                  struct list_head *list)
 147 {
 148         unsigned int i;
 149         int err = 0;
 150
 151         for (i = start; i < package->package.count; i++) {
 152                 union acpi_object *element = &package->package.elements[i];
 153                 acpi_handle rhandle;
 154
 155                 if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
 156                         err = -ENODATA;
 157                         break;
 158                 }
 159                 rhandle = element->reference.handle;
 160                 if (!rhandle) {
 161                         err = -ENODEV;
 162                         break;
 163                 }
 164                 err = acpi_add_power_resource(rhandle);
 165                 if (err)
 166                         break;
 167
 168                 err = acpi_power_resources_list_add(rhandle, list);
 169                 if (err)
 170                         break;
 171         }
 172         if (err)
 173                 acpi_power_resources_list_free(list);
 174
 175         return err;
 176 }
 177
 178 static int acpi_power_get_state(acpi_handle handle, int *state)
 179 {
 180         acpi_status status = AE_OK;
 181         unsigned long long sta = 0;
 182         char node_name[5];
 183         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 184
 185
 186         if (!handle || !state)
 187                 return -EINVAL;
 188
 189         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 190         if (ACPI_FAILURE(status))
 191                 return -ENODEV;
 192
 193         *state = (sta & 0x01)?ACPI_POWER_RESOURCE_STATE_ON:
 194                               ACPI_POWER_RESOURCE_STATE_OFF;
 195
 196         acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 197
 198         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
 199                           node_name,
 200                                 *state ? "on" : "off"));
 201
 202         return 0;
 203 }
 204
 205 static int acpi_power_get_list_state(struct list_head *list, int *state)
 206 {
 207         struct acpi_power_resource_entry *entry;
 208         int cur_state;
 209
 210         if (!list || !state)
 211                 return -EINVAL;
 212
 213         /* The state of the list is 'on' IFF all resources are 'on'. */
 214         cur_state = 0;
 215         list_for_each_entry(entry, list, node) {
 216                 struct acpi_power_resource *resource = entry->resource;
 217                 acpi_handle handle = resource->device.handle;
 218                 int result;
 219
 220                 mutex_lock(&resource->resource_lock);
 221                 result = acpi_power_get_state(handle, &cur_state);
 222                 mutex_unlock(&resource->resource_lock);
 223                 if (result)
 224                         return result;
 225
 226                 if (cur_state != ACPI_POWER_RESOURCE_STATE_ON)
 227                         break;
 228         }
 229
 230         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
 231                           cur_state ? "on" : "off"));
 232
 233         *state = cur_state;
 234         return 0;
 235 }
 236
 237 static void acpi_power_resume_dependent(struct work_struct *work)
 238 {
 239         struct acpi_power_dependent_device *dep;
 240         struct acpi_device_physical_node *pn;
 241         struct acpi_device *adev;
 242         int state;
 243
 244         dep = container_of(work, struct acpi_power_dependent_device, work);
 245         adev = dep->adev;
 246         if (acpi_power_get_inferred_state(adev, &state))
 247                 return;
 248
 249         if (state > ACPI_STATE_D0)
 250                 return;
 251
 252         mutex_lock(&adev->physical_node_lock);
 253
 254         list_for_each_entry(pn, &adev->physical_node_list, node)
 255                 pm_request_resume(pn->dev);
 256
 257         list_for_each_entry(pn, &adev->power_dependent, node)
 258                 pm_request_resume(pn->dev);
 259
 260         mutex_unlock(&adev->physical_node_lock);
 261 }
 262
 263 static int __acpi_power_on(struct acpi_power_resource *resource)
 264 {
 265         acpi_status status = AE_OK;
 266
 267         status = acpi_evaluate_object(resource->device.handle, "_ON", NULL, NULL);
 268         if (ACPI_FAILURE(status))
 269                 return -ENODEV;
 270
 271         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned on\n",
 272                           resource->name));
 273
 274         return 0;
 275 }
 276
 277 static int acpi_power_on_unlocked(struct acpi_power_resource *resource)
 278 {
 279         int result = 0;
 280
 281         if (resource->ref_count++) {
 282                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 283                                   "Power resource [%s] already on",
 284                                   resource->name));
 285         } else {
 286                 result = __acpi_power_on(resource);
 287                 if (result) {
 288                         resource->ref_count--;
 289                 } else {
 290                         struct acpi_power_dependent_device *dep;
 291
 292                         list_for_each_entry(dep, &resource->dependent, node)
 293                                 schedule_work(&dep->work);
 294                 }
 295         }
 296         return result;
 297 }
 298
 299 static int acpi_power_on(struct acpi_power_resource *resource)
 300 {
 301         int result;
 302
 303         mutex_lock(&resource->resource_lock);
 304         result = acpi_power_on_unlocked(resource);
 305         mutex_unlock(&resource->resource_lock);
 306         return result;
 307 }
 308
 309 static int __acpi_power_off(struct acpi_power_resource *resource)
 310 {
 311         acpi_status status;
 312
 313         status = acpi_evaluate_object(resource->device.handle, "_OFF",
 314                                       NULL, NULL);
 315         if (ACPI_FAILURE(status))
 316                 return -ENODEV;
 317
 318         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned off\n",
 319                           resource->name));
 320         return 0;
 321 }
 322
 323 static int acpi_power_off_unlocked(struct acpi_power_resource *resource)
 324 {
 325         int result = 0;
 326
 327         if (!resource->ref_count) {
 328                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 329                                   "Power resource [%s] already off",
 330                                   resource->name));
 331                 return 0;
 332         }
 333
 334         if (--resource->ref_count) {
 335                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 336                                   "Power resource [%s] still in use\n",
 337                                   resource->name));
 338         } else {
 339                 result = __acpi_power_off(resource);
 340                 if (result)
 341                         resource->ref_count++;
 342         }
 343         return result;
 344 }
 345
 346 static int acpi_power_off(struct acpi_power_resource *resource)
 347 {
 348         int result;
 349
 350         mutex_lock(&resource->resource_lock);
 351         result = acpi_power_off_unlocked(resource);
 352         mutex_unlock(&resource->resource_lock);
 353         return result;
 354 }
 355
 356 static int acpi_power_off_list(struct list_head *list)
 357 {
 358         struct acpi_power_resource_entry *entry;
 359         int result = 0;
 360
 361         list_for_each_entry_reverse(entry, list, node) {
 362                 result = acpi_power_off(entry->resource);
 363                 if (result)
 364                         goto err;
 365         }
 366         return 0;
 367
 368  err:
 369         list_for_each_entry_continue(entry, list, node)
 370                 acpi_power_on(entry->resource);
 371
 372         return result;
 373 }
 374
 375 static int acpi_power_on_list(struct list_head *list)
 376 {
 377         struct acpi_power_resource_entry *entry;
 378         int result = 0;
 379
 380         list_for_each_entry(entry, list, node) {
 381                 result = acpi_power_on(entry->resource);
 382                 if (result)
 383                         goto err;
 384         }
 385         return 0;
 386
 387  err:
 388         list_for_each_entry_continue_reverse(entry, list, node)
 389                 acpi_power_off(entry->resource);
 390
 391         return result;
 392 }
 393
 394 static void acpi_power_add_dependent(struct acpi_power_resource *resource,
 395                                      struct acpi_device *adev)
 396 {
 397         struct acpi_power_dependent_device *dep;
 398
 399         mutex_lock(&resource->resource_lock);
 400
 401         list_for_each_entry(dep, &resource->dependent, node)
 402                 if (dep->adev == adev)
 403                         goto out;
 404
 405         dep = kzalloc(sizeof(*dep), GFP_KERNEL);
 406         if (!dep)
 407                 goto out;
 408
 409         dep->adev = adev;
 410         INIT_WORK(&dep->work, acpi_power_resume_dependent);
 411         list_add_tail(&dep->node, &resource->dependent);
 412
 413  out:
 414         mutex_unlock(&resource->resource_lock);
 415 }
 416
 417 static void acpi_power_remove_dependent(struct acpi_power_resource *resource,
 418                                         struct acpi_device *adev)
 419 {
 420         struct acpi_power_dependent_device *dep;
 421         struct work_struct *work = NULL;
 422
 423         mutex_lock(&resource->resource_lock);
 424
 425         list_for_each_entry(dep, &resource->dependent, node)
 426                 if (dep->adev == adev) {
 427                         list_del(&dep->node);
 428                         work = &dep->work;
 429                         break;
 430                 }
 431
 432         mutex_unlock(&resource->resource_lock);
 433
 434         if (work) {
 435                 cancel_work_sync(work);
 436                 kfree(dep);
 437         }
 438 }
 439
 440 static struct attribute *attrs[] = {
 441         NULL,
 442 };
 443
 444 static struct attribute_group attr_groups[] = {
 445         [ACPI_STATE_D0] = {
 446                 .name = "power_resources_D0",
 447                 .attrs = attrs,
 448         },
 449         [ACPI_STATE_D1] = {
 450                 .name = "power_resources_D1",
 451                 .attrs = attrs,
 452         },
 453         [ACPI_STATE_D2] = {
 454                 .name = "power_resources_D2",
 455                 .attrs = attrs,
 456         },
 457         [ACPI_STATE_D3_HOT] = {
 458                 .name = "power_resources_D3hot",
 459                 .attrs = attrs,
 460         },
 461 };
 462
 463 static struct attribute_group wakeup_attr_group = {
 464         .name = "power_resources_wakeup",
 465         .attrs = attrs,
 466 };
 467
 468 static void acpi_power_hide_list(struct acpi_device *adev,
 469                                  struct list_head *resources,
 470                                  struct attribute_group *attr_group)
 471 {
 472         struct acpi_power_resource_entry *entry;
 473
 474         if (list_empty(resources))
 475                 return;
 476
 477         list_for_each_entry_reverse(entry, resources, node) {
 478                 struct acpi_device *res_dev = &entry->resource->device;
 479
 480                 sysfs_remove_link_from_group(&adev->dev.kobj,
 481                                              attr_group->name,
 482                                              dev_name(&res_dev->dev));
 483         }
 484         sysfs_remove_group(&adev->dev.kobj, attr_group);
 485 }
 486
 487 static void acpi_power_expose_list(struct acpi_device *adev,
 488                                    struct list_head *resources,
 489                                    struct attribute_group *attr_group)
 490 {
 491         struct acpi_power_resource_entry *entry;
 492         int ret;
 493
 494         if (list_empty(resources))
 495                 return;
 496
 497         ret = sysfs_create_group(&adev->dev.kobj, attr_group);
 498         if (ret)
 499                 return;
 500
 501         list_for_each_entry(entry, resources, node) {
 502                 struct acpi_device *res_dev = &entry->resource->device;
 503
 504                 ret = sysfs_add_link_to_group(&adev->dev.kobj,
 505                                               attr_group->name,
 506                                               &res_dev->dev.kobj,
 507                                               dev_name(&res_dev->dev));
 508                 if (ret) {
 509                         acpi_power_hide_list(adev, resources, attr_group);
 510                         break;
 511                 }
 512         }
 513 }
 514
 515 static void acpi_power_expose_hide(struct acpi_device *adev,
 516                                    struct list_head *resources,
 517                                    struct attribute_group *attr_group,
 518                                    bool expose)
 519 {
 520         if (expose)
 521                 acpi_power_expose_list(adev, resources, attr_group);
 522         else
 523                 acpi_power_hide_list(adev, resources, attr_group);
 524 }
 525
 526 void acpi_power_add_remove_device(struct acpi_device *adev, bool add)
 527 {
 528         struct acpi_device_power_state *ps;
 529         struct acpi_power_resource_entry *entry;
 530         int state;
 531
 532         if (adev->wakeup.flags.valid)
 533                 acpi_power_expose_hide(adev, &adev->wakeup.resources,
 534                                        &wakeup_attr_group, add);
 535
 536         if (!adev->power.flags.power_resources)
 537                 return;
 538
 539         ps = &adev->power.states[ACPI_STATE_D0];
 540         list_for_each_entry(entry, &ps->resources, node) {
 541                 struct acpi_power_resource *resource = entry->resource;
 542
 543                 if (add)
 544                         acpi_power_add_dependent(resource, adev);
 545                 else
 546                         acpi_power_remove_dependent(resource, adev);
 547         }
 548
 549         for (state = ACPI_STATE_D0; state <= ACPI_STATE_D3_HOT; state++)
 550                 acpi_power_expose_hide(adev,
 551                                        &adev->power.states[state].resources,
 552                                        &attr_groups[state], add);
 553 }
 554
 555 int acpi_power_wakeup_list_init(struct list_head *list, int *system_level_p)
 556 {
 557         struct acpi_power_resource_entry *entry;
 558         int system_level = 5;
 559
 560         list_for_each_entry(entry, list, node) {
 561                 struct acpi_power_resource *resource = entry->resource;
 562                 acpi_handle handle = resource->device.handle;
 563                 int result;
 564                 int state;
 565
 566                 mutex_lock(&resource->resource_lock);
 567
 568                 result = acpi_power_get_state(handle, &state);
 569                 if (result) {
 570                         mutex_unlock(&resource->resource_lock);
 571                         return result;
 572                 }
 573                 if (state == ACPI_POWER_RESOURCE_STATE_ON) {
 574                         resource->ref_count++;
 575                         resource->wakeup_enabled = true;
 576                 }
 577                 if (system_level > resource->system_level)
 578                         system_level = resource->system_level;
 579
 580                 mutex_unlock(&resource->resource_lock);
 581         }
 582         *system_level_p = system_level;
 583         return 0;
 584 }
 585
 586 /* --------------------------------------------------------------------------
 587                              Device Power Management
 588    -------------------------------------------------------------------------- */
 589
 590 /**
 591  * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
 592  *                          ACPI 3.0) _PSW (Power State Wake)
 593  * @dev: Device to handle.
 594  * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
 595  * @sleep_state: Target sleep state of the system.
 596  * @dev_state: Target power state of the device.
 597  *
 598  * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 599  * State Wake) for the device, if present.  On failure reset the device's
 600  * wakeup.flags.valid flag.
 601  *
 602  * RETURN VALUE:
 603  * 0 if either _DSW or _PSW has been successfully executed
 604  * 0 if neither _DSW nor _PSW has been found
 605  * -ENODEV if the execution of either _DSW or _PSW has failed
 606  */
 607 int acpi_device_sleep_wake(struct acpi_device *dev,
 608                            int enable, int sleep_state, int dev_state)
 609 {
 610         union acpi_object in_arg[3];
 611         struct acpi_object_list arg_list = { 3, in_arg };
 612         acpi_status status = AE_OK;
 613
 614         /*
 615          * Try to execute _DSW first.
 616          *
 617          * Three agruments are needed for the _DSW object:
 618          * Argument 0: enable/disable the wake capabilities
 619          * Argument 1: target system state
 620          * Argument 2: target device state
 621          * When _DSW object is called to disable the wake capabilities, maybe
 622          * the first argument is filled. The values of the other two agruments
 623          * are meaningless.
 624          */
 625         in_arg[0].type = ACPI_TYPE_INTEGER;
 626         in_arg[0].integer.value = enable;
 627         in_arg[1].type = ACPI_TYPE_INTEGER;
 628         in_arg[1].integer.value = sleep_state;
 629         in_arg[2].type = ACPI_TYPE_INTEGER;
 630         in_arg[2].integer.value = dev_state;
 631         status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
 632         if (ACPI_SUCCESS(status)) {
 633                 return 0;
 634         } else if (status != AE_NOT_FOUND) {
 635                 printk(KERN_ERR PREFIX "_DSW execution failed\n");
 636                 dev->wakeup.flags.valid = 0;
 637                 return -ENODEV;
 638         }
 639
 640         /* Execute _PSW */
 641         arg_list.count = 1;
 642         in_arg[0].integer.value = enable;
 643         status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
 644         if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
 645                 printk(KERN_ERR PREFIX "_PSW execution failed\n");
 646                 dev->wakeup.flags.valid = 0;
 647                 return -ENODEV;
 648         }
 649
 650         return 0;
 651 }
 652
 653 /*
 654  * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
 655  * 1. Power on the power resources required for the wakeup device
 656  * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 657  *    State Wake) for the device, if present
 658  */
 659 int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
 660 {
 661         struct acpi_power_resource_entry *entry;
 662         int err = 0;
 663
 664         if (!dev || !dev->wakeup.flags.valid)
 665                 return -EINVAL;
 666
 667         mutex_lock(&acpi_device_lock);
 668
 669         if (dev->wakeup.prepare_count++)
 670                 goto out;
 671
 672         list_for_each_entry(entry, &dev->wakeup.resources, node) {
 673                 struct acpi_power_resource *resource = entry->resource;
 674
 675                 mutex_lock(&resource->resource_lock);
 676
 677                 if (!resource->wakeup_enabled) {
 678                         err = acpi_power_on_unlocked(resource);
 679                         if (!err)
 680                                 resource->wakeup_enabled = true;
 681                 }
 682
 683                 mutex_unlock(&resource->resource_lock);
 684
 685                 if (err) {
 686                         dev_err(&dev->dev,
 687                                 "Cannot turn wakeup power resources on\n");
 688                         dev->wakeup.flags.valid = 0;
 689                         goto out;
 690                 }
 691         }
 692         /*
 693          * Passing 3 as the third argument below means the device may be
 694          * put into arbitrary power state afterward.
 695          */
 696         err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
 697         if (err)
 698                 dev->wakeup.prepare_count = 0;
 699
 700  out:
 701         mutex_unlock(&acpi_device_lock);
 702         return err;
 703 }
 704
 705 /*
 706  * Shutdown a wakeup device, counterpart of above method
 707  * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 708  *    State Wake) for the device, if present
 709  * 2. Shutdown down the power resources
 710  */
 711 int acpi_disable_wakeup_device_power(struct acpi_device *dev)
 712 {
 713         struct acpi_power_resource_entry *entry;
 714         int err = 0;
 715
 716         if (!dev || !dev->wakeup.flags.valid)
 717                 return -EINVAL;
 718
 719         mutex_lock(&acpi_device_lock);
 720
 721         if (--dev->wakeup.prepare_count > 0)
 722                 goto out;
 723
 724         /*
 725          * Executing the code below even if prepare_count is already zero when
 726          * the function is called may be useful, for example for initialisation.
 727          */
 728         if (dev->wakeup.prepare_count < 0)
 729                 dev->wakeup.prepare_count = 0;
 730
 731         err = acpi_device_sleep_wake(dev, 0, 0, 0);
 732         if (err)
 733                 goto out;
 734
 735         list_for_each_entry(entry, &dev->wakeup.resources, node) {
 736                 struct acpi_power_resource *resource = entry->resource;
 737
 738                 mutex_lock(&resource->resource_lock);
 739
 740                 if (resource->wakeup_enabled) {
 741                         err = acpi_power_off_unlocked(resource);
 742                         if (!err)
 743                                 resource->wakeup_enabled = false;
 744                 }
 745
 746                 mutex_unlock(&resource->resource_lock);
 747
 748                 if (err) {
 749                         dev_err(&dev->dev,
 750                                 "Cannot turn wakeup power resources off\n");
 751                         dev->wakeup.flags.valid = 0;
 752                         break;
 753                 }
 754         }
 755
 756  out:
 757         mutex_unlock(&acpi_device_lock);
 758         return err;
 759 }
 760
 761 int acpi_power_get_inferred_state(struct acpi_device *device, int *state)
 762 {
 763         int result = 0;
 764         int list_state = 0;
 765         int i = 0;
 766
 767         if (!device || !state)
 768                 return -EINVAL;
 769
 770         /*
 771          * We know a device's inferred power state when all the resources
 772          * required for a given D-state are 'on'.
 773          */
 774         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
 775                 struct list_head *list = &device->power.states[i].resources;
 776
 777                 if (list_empty(list))
 778                         continue;
 779
 780                 result = acpi_power_get_list_state(list, &list_state);
 781                 if (result)
 782                         return result;
 783
 784                 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
 785                         *state = i;
 786                         return 0;
 787                 }
 788         }
 789
 790         *state = ACPI_STATE_D3;
 791         return 0;
 792 }
 793
 794 int acpi_power_on_resources(struct acpi_device *device, int state)
 795 {
 796         if (!device || state < ACPI_STATE_D0 || state > ACPI_STATE_D3_HOT)
 797                 return -EINVAL;
 798
 799         return acpi_power_on_list(&device->power.states[state].resources);
 800 }
 801
 802 int acpi_power_transition(struct acpi_device *device, int state)
 803 {
 804         int result = 0;
 805
 806         if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
 807                 return -EINVAL;
 808
 809         if (device->power.state == state || !device->flags.power_manageable)
 810                 return 0;
 811
 812         if ((device->power.state < ACPI_STATE_D0)
 813             || (device->power.state > ACPI_STATE_D3_COLD))
 814                 return -ENODEV;
 815
 816         /* TBD: Resources must be ordered. */
 817
 818         /*
 819          * First we reference all power resources required in the target list
 820          * (e.g. so the device doesn't lose power while transitioning).  Then,
 821          * we dereference all power resources used in the current list.
 822          */
 823         if (state < ACPI_STATE_D3_COLD)
 824                 result = acpi_power_on_list(
 825                         &device->power.states[state].resources);
 826
 827         if (!result && device->power.state < ACPI_STATE_D3_COLD)
 828                 acpi_power_off_list(
 829                         &device->power.states[device->power.state].resources);
 830
 831         /* We shouldn't change the state unless the above operations succeed. */
 832         device->power.state = result ? ACPI_STATE_UNKNOWN : state;
 833
 834         return result;
 835 }
 836
 837 static void acpi_release_power_resource(struct device *dev)
 838 {
 839         struct acpi_device *device = to_acpi_device(dev);
 840         struct acpi_power_resource *resource;
 841
 842         resource = container_of(device, struct acpi_power_resource, device);
 843
 844         mutex_lock(&power_resource_list_lock);
 845         list_del(&resource->list_node);
 846         mutex_unlock(&power_resource_list_lock);
 847
 848         acpi_free_pnp_ids(&device->pnp);
 849         kfree(resource);
 850 }
 851
 852 static ssize_t acpi_power_in_use_show(struct device *dev,
 853                                       struct device_attribute *attr,
 854                                       char *buf) {
 855         struct acpi_power_resource *resource;
 856
 857         resource = to_power_resource(to_acpi_device(dev));
 858         return sprintf(buf, "%u\n", !!resource->ref_count);
 859 }
 860 static DEVICE_ATTR(resource_in_use, 0444, acpi_power_in_use_show, NULL);
 861
 862 static void acpi_power_sysfs_remove(struct acpi_device *device)
 863 {
 864         device_remove_file(&device->dev, &dev_attr_resource_in_use);
 865 }
 866
 867 int acpi_add_power_resource(acpi_handle handle)
 868 {
 869         struct acpi_power_resource *resource;
 870         struct acpi_device *device = NULL;
 871         union acpi_object acpi_object;
 872         struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
 873         acpi_status status;
 874         int state, result = -ENODEV;
 875
 876         acpi_bus_get_device(handle, &device);
 877         if (device)
 878                 return 0;
 879
 880         resource = kzalloc(sizeof(*resource), GFP_KERNEL);
 881         if (!resource)
 882                 return -ENOMEM;
 883
 884         device = &resource->device;
 885         acpi_init_device_object(device, handle, ACPI_BUS_TYPE_POWER,
 886                                 ACPI_STA_DEFAULT);
 887         mutex_init(&resource->resource_lock);
 888         INIT_LIST_HEAD(&resource->dependent);
 889         INIT_LIST_HEAD(&resource->list_node);
 890         resource->name = device->pnp.bus_id;
 891         strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
 892         strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
 893         device->power.state = ACPI_STATE_UNKNOWN;
 894
 895         /* Evalute the object to get the system level and resource order. */
 896         status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
 897         if (ACPI_FAILURE(status))
 898                 goto err;
 899
 900         resource->system_level = acpi_object.power_resource.system_level;
 901         resource->order = acpi_object.power_resource.resource_order;
 902
 903         result = acpi_power_get_state(handle, &state);
 904         if (result)
 905                 goto err;
 906
 907         printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
 908                acpi_device_bid(device), state ? "on" : "off");
 909
 910         device->flags.match_driver = true;
 911         result = acpi_device_add(device, acpi_release_power_resource);
 912         if (result)
 913                 goto err;
 914
 915         if (!device_create_file(&device->dev, &dev_attr_resource_in_use))
 916                 device->remove = acpi_power_sysfs_remove;
 917
 918         mutex_lock(&power_resource_list_lock);
 919         list_add(&resource->list_node, &acpi_power_resource_list);
 920         mutex_unlock(&power_resource_list_lock);
 921         acpi_device_add_finalize(device);
 922         return 0;
 923
 924  err:
 925         acpi_release_power_resource(&device->dev);
 926         return result;
 927 }
 928
 929 #ifdef CONFIG_ACPI_SLEEP
 930 void acpi_resume_power_resources(void)
 931 {
 932         struct acpi_power_resource *resource;
 933
 934         mutex_lock(&power_resource_list_lock);
 935
 936         list_for_each_entry(resource, &acpi_power_resource_list, list_node) {
 937                 int result, state;
 938
 939                 mutex_lock(&resource->resource_lock);
 940
 941                 result = acpi_power_get_state(resource->device.handle, &state);
 942                 if (result)
 943                         continue;
 944
 945                 if (state == ACPI_POWER_RESOURCE_STATE_OFF
 946                     && resource->ref_count) {
 947                         dev_info(&resource->device.dev, "Turning ON\n");
 948                         __acpi_power_on(resource);
 949                 } else if (state == ACPI_POWER_RESOURCE_STATE_ON
 950                     && !resource->ref_count) {
 951                         dev_info(&resource->device.dev, "Turning OFF\n");
 952                         __acpi_power_off(resource);
 953                 }
 954
 955                 mutex_unlock(&resource->resource_lock);
 956         }
 957
 958         mutex_unlock(&power_resource_list_lock);
 959 }
 960 #endif