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