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/proc_fs.h>
  43 #include <linux/seq_file.h>
  44 #include <acpi/acpi_bus.h>
  45 #include <acpi/acpi_drivers.h>
  46 #include "sleep.h"
  47
  48 #define PREFIX "ACPI: "
  49
  50 #define _COMPONENT                      ACPI_POWER_COMPONENT
  51 ACPI_MODULE_NAME("power");
  52 #define ACPI_POWER_CLASS                "power_resource"
  53 #define ACPI_POWER_DEVICE_NAME          "Power Resource"
  54 #define ACPI_POWER_FILE_INFO            "info"
  55 #define ACPI_POWER_FILE_STATUS          "state"
  56 #define ACPI_POWER_RESOURCE_STATE_OFF   0x00
  57 #define ACPI_POWER_RESOURCE_STATE_ON    0x01
  58 #define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF
  59
  60 int acpi_power_nocheck;
  61 module_param_named(power_nocheck, acpi_power_nocheck, bool, 000);
  62
  63 static int acpi_power_add(struct acpi_device *device);
  64 static int acpi_power_remove(struct acpi_device *device, int type);
  65 static int acpi_power_resume(struct acpi_device *device);
  66 static int acpi_power_open_fs(struct inode *inode, struct file *file);
  67
  68 static const struct acpi_device_id power_device_ids[] = {
  69         {ACPI_POWER_HID, 0},
  70         {"", 0},
  71 };
  72 MODULE_DEVICE_TABLE(acpi, power_device_ids);
  73
  74 static struct acpi_driver acpi_power_driver = {
  75         .name = "power",
  76         .class = ACPI_POWER_CLASS,
  77         .ids = power_device_ids,
  78         .ops = {
  79                 .add = acpi_power_add,
  80                 .remove = acpi_power_remove,
  81                 .resume = acpi_power_resume,
  82                 },
  83 };
  84
  85 struct acpi_power_reference {
  86         struct list_head node;
  87         struct acpi_device *device;
  88 };
  89
  90 struct acpi_power_resource {
  91         struct acpi_device * device;
  92         acpi_bus_id name;
  93         u32 system_level;
  94         u32 order;
  95         struct mutex resource_lock;
  96         struct list_head reference;
  97 };
  98
  99 static struct list_head acpi_power_resource_list;
 100
 101 static const struct file_operations acpi_power_fops = {
 102         .owner = THIS_MODULE,
 103         .open = acpi_power_open_fs,
 104         .read = seq_read,
 105         .llseek = seq_lseek,
 106         .release = single_release,
 107 };
 108
 109 /* --------------------------------------------------------------------------
 110                              Power Resource Management
 111    -------------------------------------------------------------------------- */
 112
 113 static int
 114 acpi_power_get_context(acpi_handle handle,
 115                        struct acpi_power_resource **resource)
 116 {
 117         int result = 0;
 118         struct acpi_device *device = NULL;
 119
 120
 121         if (!resource)
 122                 return -ENODEV;
 123
 124         result = acpi_bus_get_device(handle, &device);
 125         if (result) {
 126                 printk(KERN_WARNING PREFIX "Getting context [%p]\n", handle);
 127                 return result;
 128         }
 129
 130         *resource = acpi_driver_data(device);
 131         if (!*resource)
 132                 return -ENODEV;
 133
 134         return 0;
 135 }
 136
 137 static int acpi_power_get_state(acpi_handle handle, int *state)
 138 {
 139         acpi_status status = AE_OK;
 140         unsigned long long sta = 0;
 141         char node_name[5];
 142         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 143
 144
 145         if (!handle || !state)
 146                 return -EINVAL;
 147
 148         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 149         if (ACPI_FAILURE(status))
 150                 return -ENODEV;
 151
 152         *state = (sta & 0x01)?ACPI_POWER_RESOURCE_STATE_ON:
 153                               ACPI_POWER_RESOURCE_STATE_OFF;
 154
 155         acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 156
 157         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
 158                           node_name,
 159                                 *state ? "on" : "off"));
 160
 161         return 0;
 162 }
 163
 164 static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
 165 {
 166         int result = 0, state1;
 167         u32 i = 0;
 168
 169
 170         if (!list || !state)
 171                 return -EINVAL;
 172
 173         /* The state of the list is 'on' IFF all resources are 'on'. */
 174
 175         for (i = 0; i < list->count; i++) {
 176                 /*
 177                  * The state of the power resource can be obtained by
 178                  * using the ACPI handle. In such case it is unnecessary to
 179                  * get the Power resource first and then get its state again.
 180                  */
 181                 result = acpi_power_get_state(list->handles[i], &state1);
 182                 if (result)
 183                         return result;
 184
 185                 *state = state1;
 186
 187                 if (*state != ACPI_POWER_RESOURCE_STATE_ON)
 188                         break;
 189         }
 190
 191         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
 192                           *state ? "on" : "off"));
 193
 194         return result;
 195 }
 196
 197 static int acpi_power_on(acpi_handle handle, struct acpi_device *dev)
 198 {
 199         int result = 0;
 200         int found = 0;
 201         acpi_status status = AE_OK;
 202         struct acpi_power_resource *resource = NULL;
 203         struct list_head *node, *next;
 204         struct acpi_power_reference *ref;
 205
 206
 207         result = acpi_power_get_context(handle, &resource);
 208         if (result)
 209                 return result;
 210
 211         mutex_lock(&resource->resource_lock);
 212         list_for_each_safe(node, next, &resource->reference) {
 213                 ref = container_of(node, struct acpi_power_reference, node);
 214                 if (dev->handle == ref->device->handle) {
 215                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] already referenced by resource [%s]\n",
 216                                   dev->pnp.bus_id, resource->name));
 217                         found = 1;
 218                         break;
 219                 }
 220         }
 221
 222         if (!found) {
 223                 ref = kmalloc(sizeof (struct acpi_power_reference),
 224                     irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL);
 225                 if (!ref) {
 226                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "kmalloc() failed\n"));
 227                         mutex_unlock(&resource->resource_lock);
 228                         return -ENOMEM;
 229                 }
 230                 list_add_tail(&ref->node, &resource->reference);
 231                 ref->device = dev;
 232                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] added to resource [%s] references\n",
 233                           dev->pnp.bus_id, resource->name));
 234         }
 235         mutex_unlock(&resource->resource_lock);
 236
 237         status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL);
 238         if (ACPI_FAILURE(status))
 239                 return -ENODEV;
 240
 241         /* Update the power resource's _device_ power state */
 242         resource->device->power.state = ACPI_STATE_D0;
 243
 244         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned on\n",
 245                           resource->name));
 246         return 0;
 247 }
 248
 249 static int acpi_power_off_device(acpi_handle handle, struct acpi_device *dev)
 250 {
 251         int result = 0;
 252         acpi_status status = AE_OK;
 253         struct acpi_power_resource *resource = NULL;
 254         struct list_head *node, *next;
 255         struct acpi_power_reference *ref;
 256
 257
 258         result = acpi_power_get_context(handle, &resource);
 259         if (result)
 260                 return result;
 261
 262         mutex_lock(&resource->resource_lock);
 263         list_for_each_safe(node, next, &resource->reference) {
 264                 ref = container_of(node, struct acpi_power_reference, node);
 265                 if (dev->handle == ref->device->handle) {
 266                         list_del(&ref->node);
 267                         kfree(ref);
 268                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] removed from resource [%s] references\n",
 269                             dev->pnp.bus_id, resource->name));
 270                         break;
 271                 }
 272         }
 273
 274         if (!list_empty(&resource->reference)) {
 275                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Cannot turn resource [%s] off - resource is in use\n",
 276                     resource->name));
 277                 mutex_unlock(&resource->resource_lock);
 278                 return 0;
 279         }
 280         mutex_unlock(&resource->resource_lock);
 281
 282         status = acpi_evaluate_object(resource->device->handle, "_OFF", NULL, NULL);
 283         if (ACPI_FAILURE(status))
 284                 return -ENODEV;
 285
 286         /* Update the power resource's _device_ power state */
 287         resource->device->power.state = ACPI_STATE_D3;
 288
 289         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned off\n",
 290                           resource->name));
 291
 292         return 0;
 293 }
 294
 295 /**
 296  * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
 297  *                          ACPI 3.0) _PSW (Power State Wake)
 298  * @dev: Device to handle.
 299  * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
 300  * @sleep_state: Target sleep state of the system.
 301  * @dev_state: Target power state of the device.
 302  *
 303  * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 304  * State Wake) for the device, if present.  On failure reset the device's
 305  * wakeup.flags.valid flag.
 306  *
 307  * RETURN VALUE:
 308  * 0 if either _DSW or _PSW has been successfully executed
 309  * 0 if neither _DSW nor _PSW has been found
 310  * -ENODEV if the execution of either _DSW or _PSW has failed
 311  */
 312 int acpi_device_sleep_wake(struct acpi_device *dev,
 313                            int enable, int sleep_state, int dev_state)
 314 {
 315         union acpi_object in_arg[3];
 316         struct acpi_object_list arg_list = { 3, in_arg };
 317         acpi_status status = AE_OK;
 318
 319         /*
 320          * Try to execute _DSW first.
 321          *
 322          * Three agruments are needed for the _DSW object:
 323          * Argument 0: enable/disable the wake capabilities
 324          * Argument 1: target system state
 325          * Argument 2: target device state
 326          * When _DSW object is called to disable the wake capabilities, maybe
 327          * the first argument is filled. The values of the other two agruments
 328          * are meaningless.
 329          */
 330         in_arg[0].type = ACPI_TYPE_INTEGER;
 331         in_arg[0].integer.value = enable;
 332         in_arg[1].type = ACPI_TYPE_INTEGER;
 333         in_arg[1].integer.value = sleep_state;
 334         in_arg[2].type = ACPI_TYPE_INTEGER;
 335         in_arg[2].integer.value = dev_state;
 336         status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
 337         if (ACPI_SUCCESS(status)) {
 338                 return 0;
 339         } else if (status != AE_NOT_FOUND) {
 340                 printk(KERN_ERR PREFIX "_DSW execution failed\n");
 341                 dev->wakeup.flags.valid = 0;
 342                 return -ENODEV;
 343         }
 344
 345         /* Execute _PSW */
 346         arg_list.count = 1;
 347         in_arg[0].integer.value = enable;
 348         status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
 349         if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
 350                 printk(KERN_ERR PREFIX "_PSW execution failed\n");
 351                 dev->wakeup.flags.valid = 0;
 352                 return -ENODEV;
 353         }
 354
 355         return 0;
 356 }
 357
 358 /*
 359  * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
 360  * 1. Power on the power resources required for the wakeup device
 361  * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 362  *    State Wake) for the device, if present
 363  */
 364 int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
 365 {
 366         int i, err = 0;
 367
 368         if (!dev || !dev->wakeup.flags.valid)
 369                 return -EINVAL;
 370
 371         mutex_lock(&acpi_device_lock);
 372
 373         if (dev->wakeup.prepare_count++)
 374                 goto out;
 375
 376         /* Open power resource */
 377         for (i = 0; i < dev->wakeup.resources.count; i++) {
 378                 int ret = acpi_power_on(dev->wakeup.resources.handles[i], dev);
 379                 if (ret) {
 380                         printk(KERN_ERR PREFIX "Transition power state\n");
 381                         dev->wakeup.flags.valid = 0;
 382                         err = -ENODEV;
 383                         goto err_out;
 384                 }
 385         }
 386
 387         /*
 388          * Passing 3 as the third argument below means the device may be placed
 389          * in arbitrary power state afterwards.
 390          */
 391         err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
 392
 393  err_out:
 394         if (err)
 395                 dev->wakeup.prepare_count = 0;
 396
 397  out:
 398         mutex_unlock(&acpi_device_lock);
 399         return err;
 400 }
 401
 402 /*
 403  * Shutdown a wakeup device, counterpart of above method
 404  * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 405  *    State Wake) for the device, if present
 406  * 2. Shutdown down the power resources
 407  */
 408 int acpi_disable_wakeup_device_power(struct acpi_device *dev)
 409 {
 410         int i, err = 0;
 411
 412         if (!dev || !dev->wakeup.flags.valid)
 413                 return -EINVAL;
 414
 415         mutex_lock(&acpi_device_lock);
 416
 417         if (--dev->wakeup.prepare_count > 0)
 418                 goto out;
 419
 420         /*
 421          * Executing the code below even if prepare_count is already zero when
 422          * the function is called may be useful, for example for initialisation.
 423          */
 424         if (dev->wakeup.prepare_count < 0)
 425                 dev->wakeup.prepare_count = 0;
 426
 427         err = acpi_device_sleep_wake(dev, 0, 0, 0);
 428         if (err)
 429                 goto out;
 430
 431         /* Close power resource */
 432         for (i = 0; i < dev->wakeup.resources.count; i++) {
 433                 int ret = acpi_power_off_device(
 434                                 dev->wakeup.resources.handles[i], dev);
 435                 if (ret) {
 436                         printk(KERN_ERR PREFIX "Transition power state\n");
 437                         dev->wakeup.flags.valid = 0;
 438                         err = -ENODEV;
 439                         goto out;
 440                 }
 441         }
 442
 443  out:
 444         mutex_unlock(&acpi_device_lock);
 445         return err;
 446 }
 447
 448 /* --------------------------------------------------------------------------
 449                              Device Power Management
 450    -------------------------------------------------------------------------- */
 451
 452 int acpi_power_get_inferred_state(struct acpi_device *device)
 453 {
 454         int result = 0;
 455         struct acpi_handle_list *list = NULL;
 456         int list_state = 0;
 457         int i = 0;
 458
 459
 460         if (!device)
 461                 return -EINVAL;
 462
 463         device->power.state = ACPI_STATE_UNKNOWN;
 464
 465         /*
 466          * We know a device's inferred power state when all the resources
 467          * required for a given D-state are 'on'.
 468          */
 469         for (i = ACPI_STATE_D0; i < ACPI_STATE_D3; i++) {
 470                 list = &device->power.states[i].resources;
 471                 if (list->count < 1)
 472                         continue;
 473
 474                 result = acpi_power_get_list_state(list, &list_state);
 475                 if (result)
 476                         return result;
 477
 478                 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
 479                         device->power.state = i;
 480                         return 0;
 481                 }
 482         }
 483
 484         device->power.state = ACPI_STATE_D3;
 485
 486         return 0;
 487 }
 488
 489 int acpi_power_transition(struct acpi_device *device, int state)
 490 {
 491         int result = 0;
 492         struct acpi_handle_list *cl = NULL;     /* Current Resources */
 493         struct acpi_handle_list *tl = NULL;     /* Target Resources */
 494         int i = 0;
 495
 496
 497         if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
 498                 return -EINVAL;
 499
 500         if ((device->power.state < ACPI_STATE_D0)
 501             || (device->power.state > ACPI_STATE_D3))
 502                 return -ENODEV;
 503
 504         cl = &device->power.states[device->power.state].resources;
 505         tl = &device->power.states[state].resources;
 506
 507         /* TBD: Resources must be ordered. */
 508
 509         /*
 510          * First we reference all power resources required in the target list
 511          * (e.g. so the device doesn't lose power while transitioning).
 512          */
 513         for (i = 0; i < tl->count; i++) {
 514                 result = acpi_power_on(tl->handles[i], device);
 515                 if (result)
 516                         goto end;
 517         }
 518
 519         if (device->power.state == state) {
 520                 goto end;
 521         }
 522
 523         /*
 524          * Then we dereference all power resources used in the current list.
 525          */
 526         for (i = 0; i < cl->count; i++) {
 527                 result = acpi_power_off_device(cl->handles[i], device);
 528                 if (result)
 529                         goto end;
 530         }
 531
 532      end:
 533         if (result)
 534                 device->power.state = ACPI_STATE_UNKNOWN;
 535         else {
 536         /* We shouldn't change the state till all above operations succeed */
 537                 device->power.state = state;
 538         }
 539
 540         return result;
 541 }
 542
 543 /* --------------------------------------------------------------------------
 544                               FS Interface (/proc)
 545    -------------------------------------------------------------------------- */
 546
 547 static struct proc_dir_entry *acpi_power_dir;
 548
 549 static int acpi_power_seq_show(struct seq_file *seq, void *offset)
 550 {
 551         int count = 0;
 552         int result = 0, state;
 553         struct acpi_power_resource *resource = NULL;
 554         struct list_head *node, *next;
 555         struct acpi_power_reference *ref;
 556
 557
 558         resource = seq->private;
 559
 560         if (!resource)
 561                 goto end;
 562
 563         result = acpi_power_get_state(resource->device->handle, &state);
 564         if (result)
 565                 goto end;
 566
 567         seq_puts(seq, "state:                   ");
 568         switch (state) {
 569         case ACPI_POWER_RESOURCE_STATE_ON:
 570                 seq_puts(seq, "on\n");
 571                 break;
 572         case ACPI_POWER_RESOURCE_STATE_OFF:
 573                 seq_puts(seq, "off\n");
 574                 break;
 575         default:
 576                 seq_puts(seq, "unknown\n");
 577                 break;
 578         }
 579
 580         mutex_lock(&resource->resource_lock);
 581         list_for_each_safe(node, next, &resource->reference) {
 582                 ref = container_of(node, struct acpi_power_reference, node);
 583                 count++;
 584         }
 585         mutex_unlock(&resource->resource_lock);
 586
 587         seq_printf(seq, "system level:            S%d\n"
 588                    "order:                   %d\n"
 589                    "reference count:         %d\n",
 590                    resource->system_level,
 591                    resource->order, count);
 592
 593       end:
 594         return 0;
 595 }
 596
 597 static int acpi_power_open_fs(struct inode *inode, struct file *file)
 598 {
 599         return single_open(file, acpi_power_seq_show, PDE(inode)->data);
 600 }
 601
 602 static int acpi_power_add_fs(struct acpi_device *device)
 603 {
 604         struct proc_dir_entry *entry = NULL;
 605
 606
 607         if (!device)
 608                 return -EINVAL;
 609
 610         if (!acpi_device_dir(device)) {
 611                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 612                                                      acpi_power_dir);
 613                 if (!acpi_device_dir(device))
 614                         return -ENODEV;
 615         }
 616
 617         /* 'status' [R] */
 618         entry = proc_create_data(ACPI_POWER_FILE_STATUS,
 619                                  S_IRUGO, acpi_device_dir(device),
 620                                  &acpi_power_fops, acpi_driver_data(device));
 621         if (!entry)
 622                 return -EIO;
 623         return 0;
 624 }
 625
 626 static int acpi_power_remove_fs(struct acpi_device *device)
 627 {
 628
 629         if (acpi_device_dir(device)) {
 630                 remove_proc_entry(ACPI_POWER_FILE_STATUS,
 631                                   acpi_device_dir(device));
 632                 remove_proc_entry(acpi_device_bid(device), acpi_power_dir);
 633                 acpi_device_dir(device) = NULL;
 634         }
 635
 636         return 0;
 637 }
 638
 639 /* --------------------------------------------------------------------------
 640                                 Driver Interface
 641    -------------------------------------------------------------------------- */
 642
 643 static int acpi_power_add(struct acpi_device *device)
 644 {
 645         int result = 0, state;
 646         acpi_status status = AE_OK;
 647         struct acpi_power_resource *resource = NULL;
 648         union acpi_object acpi_object;
 649         struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
 650
 651
 652         if (!device)
 653                 return -EINVAL;
 654
 655         resource = kzalloc(sizeof(struct acpi_power_resource), GFP_KERNEL);
 656         if (!resource)
 657                 return -ENOMEM;
 658
 659         resource->device = device;
 660         mutex_init(&resource->resource_lock);
 661         INIT_LIST_HEAD(&resource->reference);
 662         strcpy(resource->name, device->pnp.bus_id);
 663         strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
 664         strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
 665         device->driver_data = resource;
 666
 667         /* Evalute the object to get the system level and resource order. */
 668         status = acpi_evaluate_object(device->handle, NULL, NULL, &buffer);
 669         if (ACPI_FAILURE(status)) {
 670                 result = -ENODEV;
 671                 goto end;
 672         }
 673         resource->system_level = acpi_object.power_resource.system_level;
 674         resource->order = acpi_object.power_resource.resource_order;
 675
 676         result = acpi_power_get_state(device->handle, &state);
 677         if (result)
 678                 goto end;
 679
 680         switch (state) {
 681         case ACPI_POWER_RESOURCE_STATE_ON:
 682                 device->power.state = ACPI_STATE_D0;
 683                 break;
 684         case ACPI_POWER_RESOURCE_STATE_OFF:
 685                 device->power.state = ACPI_STATE_D3;
 686                 break;
 687         default:
 688                 device->power.state = ACPI_STATE_UNKNOWN;
 689                 break;
 690         }
 691
 692         result = acpi_power_add_fs(device);
 693         if (result)
 694                 goto end;
 695
 696         printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
 697                acpi_device_bid(device), state ? "on" : "off");
 698
 699       end:
 700         if (result)
 701                 kfree(resource);
 702
 703         return result;
 704 }
 705
 706 static int acpi_power_remove(struct acpi_device *device, int type)
 707 {
 708         struct acpi_power_resource *resource = NULL;
 709         struct list_head *node, *next;
 710
 711
 712         if (!device || !acpi_driver_data(device))
 713                 return -EINVAL;
 714
 715         resource = acpi_driver_data(device);
 716
 717         acpi_power_remove_fs(device);
 718
 719         mutex_lock(&resource->resource_lock);
 720         list_for_each_safe(node, next, &resource->reference) {
 721                 struct acpi_power_reference *ref = container_of(node, struct acpi_power_reference, node);
 722                 list_del(&ref->node);
 723                 kfree(ref);
 724         }
 725         mutex_unlock(&resource->resource_lock);
 726
 727         kfree(resource);
 728
 729         return 0;
 730 }
 731
 732 static int acpi_power_resume(struct acpi_device *device)
 733 {
 734         int result = 0, state;
 735         struct acpi_power_resource *resource = NULL;
 736         struct acpi_power_reference *ref;
 737
 738         if (!device || !acpi_driver_data(device))
 739                 return -EINVAL;
 740
 741         resource = acpi_driver_data(device);
 742
 743         result = acpi_power_get_state(device->handle, &state);
 744         if (result)
 745                 return result;
 746
 747         mutex_lock(&resource->resource_lock);
 748         if (state == ACPI_POWER_RESOURCE_STATE_OFF &&
 749             !list_empty(&resource->reference)) {
 750                 ref = container_of(resource->reference.next, struct acpi_power_reference, node);
 751                 mutex_unlock(&resource->resource_lock);
 752                 result = acpi_power_on(device->handle, ref->device);
 753                 return result;
 754         }
 755
 756         mutex_unlock(&resource->resource_lock);
 757         return 0;
 758 }
 759
 760 int __init acpi_power_init(void)
 761 {
 762         int result = 0;
 763
 764         INIT_LIST_HEAD(&acpi_power_resource_list);
 765
 766         acpi_power_dir = proc_mkdir(ACPI_POWER_CLASS, acpi_root_dir);
 767         if (!acpi_power_dir)
 768                 return -ENODEV;
 769
 770         result = acpi_bus_register_driver(&acpi_power_driver);
 771         if (result < 0) {
 772                 remove_proc_entry(ACPI_POWER_CLASS, acpi_root_dir);
 773                 return -ENODEV;
 774         }
 775
 776         return 0;
 777 }