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
  47 #define _COMPONENT              ACPI_POWER_COMPONENT
  48 ACPI_MODULE_NAME("power");
  49 #define ACPI_POWER_COMPONENT            0x00800000
  50 #define ACPI_POWER_CLASS                "power_resource"
  51 #define ACPI_POWER_DEVICE_NAME          "Power Resource"
  52 #define ACPI_POWER_FILE_INFO            "info"
  53 #define ACPI_POWER_FILE_STATUS          "state"
  54 #define ACPI_POWER_RESOURCE_STATE_OFF   0x00
  55 #define ACPI_POWER_RESOURCE_STATE_ON    0x01
  56 #define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF
  57 static int acpi_power_add(struct acpi_device *device);
  58 static int acpi_power_remove(struct acpi_device *device, int type);
  59 static int acpi_power_resume(struct acpi_device *device);
  60 static int acpi_power_open_fs(struct inode *inode, struct file *file);
  61
  62 static struct acpi_device_id power_device_ids[] = {
  63         {ACPI_POWER_HID, 0},
  64         {"", 0},
  65 };
  66 MODULE_DEVICE_TABLE(acpi, power_device_ids);
  67
  68 static struct acpi_driver acpi_power_driver = {
  69         .name = "power",
  70         .class = ACPI_POWER_CLASS,
  71         .ids = power_device_ids,
  72         .ops = {
  73                 .add = acpi_power_add,
  74                 .remove = acpi_power_remove,
  75                 .resume = acpi_power_resume,
  76                 },
  77 };
  78
  79 struct acpi_power_reference {
  80         struct list_head node;
  81         struct acpi_device *device;
  82 };
  83
  84 struct acpi_power_resource {
  85         struct acpi_device * device;
  86         acpi_bus_id name;
  87         u32 system_level;
  88         u32 order;
  89         struct mutex resource_lock;
  90         struct list_head reference;
  91 };
  92
  93 static struct list_head acpi_power_resource_list;
  94
  95 static const struct file_operations acpi_power_fops = {
  96         .owner = THIS_MODULE,
  97         .open = acpi_power_open_fs,
  98         .read = seq_read,
  99         .llseek = seq_lseek,
 100         .release = single_release,
 101 };
 102
 103 /* --------------------------------------------------------------------------
 104                              Power Resource Management
 105    -------------------------------------------------------------------------- */
 106
 107 static int
 108 acpi_power_get_context(acpi_handle handle,
 109                        struct acpi_power_resource **resource)
 110 {
 111         int result = 0;
 112         struct acpi_device *device = NULL;
 113
 114
 115         if (!resource)
 116                 return -ENODEV;
 117
 118         result = acpi_bus_get_device(handle, &device);
 119         if (result) {
 120                 printk(KERN_WARNING PREFIX "Getting context [%p]\n", handle);
 121                 return result;
 122         }
 123
 124         *resource = acpi_driver_data(device);
 125         if (!*resource)
 126                 return -ENODEV;
 127
 128         return 0;
 129 }
 130
 131 static int acpi_power_get_state(struct acpi_power_resource *resource, int *state)
 132 {
 133         acpi_status status = AE_OK;
 134         unsigned long sta = 0;
 135
 136
 137         if (!resource || !state)
 138                 return -EINVAL;
 139
 140         status = acpi_evaluate_integer(resource->device->handle, "_STA", NULL, &sta);
 141         if (ACPI_FAILURE(status))
 142                 return -ENODEV;
 143
 144         *state = (sta & 0x01)?ACPI_POWER_RESOURCE_STATE_ON:
 145                               ACPI_POWER_RESOURCE_STATE_OFF;
 146
 147         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
 148                           resource->name, state ? "on" : "off"));
 149
 150         return 0;
 151 }
 152
 153 static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
 154 {
 155         int result = 0, state1;
 156         struct acpi_power_resource *resource = NULL;
 157         u32 i = 0;
 158
 159
 160         if (!list || !state)
 161                 return -EINVAL;
 162
 163         /* The state of the list is 'on' IFF all resources are 'on'. */
 164
 165         for (i = 0; i < list->count; i++) {
 166                 result = acpi_power_get_context(list->handles[i], &resource);
 167                 if (result)
 168                         return result;
 169                 result = acpi_power_get_state(resource, &state1);
 170                 if (result)
 171                         return result;
 172
 173                 *state = state1;
 174
 175                 if (*state != ACPI_POWER_RESOURCE_STATE_ON)
 176                         break;
 177         }
 178
 179         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
 180                           *state ? "on" : "off"));
 181
 182         return result;
 183 }
 184
 185 static int acpi_power_on(acpi_handle handle, struct acpi_device *dev)
 186 {
 187         int result = 0, state;
 188         int found = 0;
 189         acpi_status status = AE_OK;
 190         struct acpi_power_resource *resource = NULL;
 191         struct list_head *node, *next;
 192         struct acpi_power_reference *ref;
 193
 194
 195         result = acpi_power_get_context(handle, &resource);
 196         if (result)
 197                 return result;
 198
 199         mutex_lock(&resource->resource_lock);
 200         list_for_each_safe(node, next, &resource->reference) {
 201                 ref = container_of(node, struct acpi_power_reference, node);
 202                 if (dev->handle == ref->device->handle) {
 203                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] already referenced by resource [%s]\n",
 204                                   dev->pnp.bus_id, resource->name));
 205                         found = 1;
 206                         break;
 207                 }
 208         }
 209
 210         if (!found) {
 211                 ref = kmalloc(sizeof (struct acpi_power_reference),
 212                     irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL);
 213                 if (!ref) {
 214                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "kmalloc() failed\n"));
 215                         mutex_unlock(&resource->resource_lock);
 216                         return -ENOMEM;
 217                 }
 218                 list_add_tail(&ref->node, &resource->reference);
 219                 ref->device = dev;
 220                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] added to resource [%s] references\n",
 221                           dev->pnp.bus_id, resource->name));
 222         }
 223         mutex_unlock(&resource->resource_lock);
 224
 225         status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL);
 226         if (ACPI_FAILURE(status))
 227                 return -ENODEV;
 228
 229         result = acpi_power_get_state(resource, &state);
 230         if (result)
 231                 return result;
 232         if (state != ACPI_POWER_RESOURCE_STATE_ON)
 233                 return -ENOEXEC;
 234
 235         /* Update the power resource's _device_ power state */
 236         resource->device->power.state = ACPI_STATE_D0;
 237
 238         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned on\n",
 239                           resource->name));
 240         return 0;
 241 }
 242
 243 static int acpi_power_off_device(acpi_handle handle, struct acpi_device *dev)
 244 {
 245         int result = 0, state;
 246         acpi_status status = AE_OK;
 247         struct acpi_power_resource *resource = NULL;
 248         struct list_head *node, *next;
 249         struct acpi_power_reference *ref;
 250
 251
 252         result = acpi_power_get_context(handle, &resource);
 253         if (result)
 254                 return result;
 255
 256         mutex_lock(&resource->resource_lock);
 257         list_for_each_safe(node, next, &resource->reference) {
 258                 ref = container_of(node, struct acpi_power_reference, node);
 259                 if (dev->handle == ref->device->handle) {
 260                         list_del(&ref->node);
 261                         kfree(ref);
 262                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] removed from resource [%s] references\n",
 263                             dev->pnp.bus_id, resource->name));
 264                         break;
 265                 }
 266         }
 267
 268         if (!list_empty(&resource->reference)) {
 269                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Cannot turn resource [%s] off - resource is in use\n",
 270                     resource->name));
 271                 mutex_unlock(&resource->resource_lock);
 272                 return 0;
 273         }
 274         mutex_unlock(&resource->resource_lock);
 275
 276         status = acpi_evaluate_object(resource->device->handle, "_OFF", NULL, NULL);
 277         if (ACPI_FAILURE(status))
 278                 return -ENODEV;
 279
 280         result = acpi_power_get_state(resource, &state);
 281         if (result)
 282                 return result;
 283         if (state != ACPI_POWER_RESOURCE_STATE_OFF)
 284                 return -ENOEXEC;
 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;
 367
 368         if (!dev || !dev->wakeup.flags.valid)
 369                 return -EINVAL;
 370
 371         /*
 372          * Do not execute the code below twice in a row without calling
 373          * acpi_disable_wakeup_device_power() in between for the same device
 374          */
 375         if (dev->wakeup.flags.prepared)
 376                 return 0;
 377
 378         /* Open power resource */
 379         for (i = 0; i < dev->wakeup.resources.count; i++) {
 380                 int ret = acpi_power_on(dev->wakeup.resources.handles[i], dev);
 381                 if (ret) {
 382                         printk(KERN_ERR PREFIX "Transition power state\n");
 383                         dev->wakeup.flags.valid = 0;
 384                         return -ENODEV;
 385                 }
 386         }
 387
 388         /*
 389          * Passing 3 as the third argument below means the device may be placed
 390          * in arbitrary power state afterwards.
 391          */
 392         err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
 393         if (!err)
 394                 dev->wakeup.flags.prepared = 1;
 395
 396         return err;
 397 }
 398
 399 /*
 400  * Shutdown a wakeup device, counterpart of above method
 401  * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 402  *    State Wake) for the device, if present
 403  * 2. Shutdown down the power resources
 404  */
 405 int acpi_disable_wakeup_device_power(struct acpi_device *dev)
 406 {
 407         int i, ret;
 408
 409         if (!dev || !dev->wakeup.flags.valid)
 410                 return -EINVAL;
 411
 412         /*
 413          * Do not execute the code below twice in a row without calling
 414          * acpi_enable_wakeup_device_power() in between for the same device
 415          */
 416         if (!dev->wakeup.flags.prepared)
 417                 return 0;
 418
 419         dev->wakeup.flags.prepared = 0;
 420
 421         ret = acpi_device_sleep_wake(dev, 0, 0, 0);
 422         if (ret)
 423                 return ret;
 424
 425         /* Close power resource */
 426         for (i = 0; i < dev->wakeup.resources.count; i++) {
 427                 ret = acpi_power_off_device(dev->wakeup.resources.handles[i], dev);
 428                 if (ret) {
 429                         printk(KERN_ERR PREFIX "Transition power state\n");
 430                         dev->wakeup.flags.valid = 0;
 431                         return -ENODEV;
 432                 }
 433         }
 434
 435         return ret;
 436 }
 437
 438 /* --------------------------------------------------------------------------
 439                              Device Power Management
 440    -------------------------------------------------------------------------- */
 441
 442 int acpi_power_get_inferred_state(struct acpi_device *device)
 443 {
 444         int result = 0;
 445         struct acpi_handle_list *list = NULL;
 446         int list_state = 0;
 447         int i = 0;
 448
 449
 450         if (!device)
 451                 return -EINVAL;
 452
 453         device->power.state = ACPI_STATE_UNKNOWN;
 454
 455         /*
 456          * We know a device's inferred power state when all the resources
 457          * required for a given D-state are 'on'.
 458          */
 459         for (i = ACPI_STATE_D0; i < ACPI_STATE_D3; i++) {
 460                 list = &device->power.states[i].resources;
 461                 if (list->count < 1)
 462                         continue;
 463
 464                 result = acpi_power_get_list_state(list, &list_state);
 465                 if (result)
 466                         return result;
 467
 468                 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
 469                         device->power.state = i;
 470                         return 0;
 471                 }
 472         }
 473
 474         device->power.state = ACPI_STATE_D3;
 475
 476         return 0;
 477 }
 478
 479 int acpi_power_transition(struct acpi_device *device, int state)
 480 {
 481         int result = 0;
 482         struct acpi_handle_list *cl = NULL;     /* Current Resources */
 483         struct acpi_handle_list *tl = NULL;     /* Target Resources */
 484         int i = 0;
 485
 486
 487         if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
 488                 return -EINVAL;
 489
 490         if ((device->power.state < ACPI_STATE_D0)
 491             || (device->power.state > ACPI_STATE_D3))
 492                 return -ENODEV;
 493
 494         cl = &device->power.states[device->power.state].resources;
 495         tl = &device->power.states[state].resources;
 496
 497         if (!cl->count && !tl->count) {
 498                 result = -ENODEV;
 499                 goto end;
 500         }
 501
 502         /* TBD: Resources must be ordered. */
 503
 504         /*
 505          * First we reference all power resources required in the target list
 506          * (e.g. so the device doesn't lose power while transitioning).
 507          */
 508         for (i = 0; i < tl->count; i++) {
 509                 result = acpi_power_on(tl->handles[i], device);
 510                 if (result)
 511                         goto end;
 512         }
 513
 514         if (device->power.state == state) {
 515                 goto end;
 516         }
 517
 518         /*
 519          * Then we dereference all power resources used in the current list.
 520          */
 521         for (i = 0; i < cl->count; i++) {
 522                 result = acpi_power_off_device(cl->handles[i], device);
 523                 if (result)
 524                         goto end;
 525         }
 526
 527      end:
 528         if (result)
 529                 device->power.state = ACPI_STATE_UNKNOWN;
 530         else {
 531         /* We shouldn't change the state till all above operations succeed */
 532                 device->power.state = state;
 533         }
 534
 535         return result;
 536 }
 537
 538 /* --------------------------------------------------------------------------
 539                               FS Interface (/proc)
 540    -------------------------------------------------------------------------- */
 541
 542 static struct proc_dir_entry *acpi_power_dir;
 543
 544 static int acpi_power_seq_show(struct seq_file *seq, void *offset)
 545 {
 546         int count = 0;
 547         int result = 0, state;
 548         struct acpi_power_resource *resource = NULL;
 549         struct list_head *node, *next;
 550         struct acpi_power_reference *ref;
 551
 552
 553         resource = seq->private;
 554
 555         if (!resource)
 556                 goto end;
 557
 558         result = acpi_power_get_state(resource, &state);
 559         if (result)
 560                 goto end;
 561
 562         seq_puts(seq, "state:                   ");
 563         switch (state) {
 564         case ACPI_POWER_RESOURCE_STATE_ON:
 565                 seq_puts(seq, "on\n");
 566                 break;
 567         case ACPI_POWER_RESOURCE_STATE_OFF:
 568                 seq_puts(seq, "off\n");
 569                 break;
 570         default:
 571                 seq_puts(seq, "unknown\n");
 572                 break;
 573         }
 574
 575         mutex_lock(&resource->resource_lock);
 576         list_for_each_safe(node, next, &resource->reference) {
 577                 ref = container_of(node, struct acpi_power_reference, node);
 578                 count++;
 579         }
 580         mutex_unlock(&resource->resource_lock);
 581
 582         seq_printf(seq, "system level:            S%d\n"
 583                    "order:                   %d\n"
 584                    "reference count:         %d\n",
 585                    resource->system_level,
 586                    resource->order, count);
 587
 588       end:
 589         return 0;
 590 }
 591
 592 static int acpi_power_open_fs(struct inode *inode, struct file *file)
 593 {
 594         return single_open(file, acpi_power_seq_show, PDE(inode)->data);
 595 }
 596
 597 static int acpi_power_add_fs(struct acpi_device *device)
 598 {
 599         struct proc_dir_entry *entry = NULL;
 600
 601
 602         if (!device)
 603                 return -EINVAL;
 604
 605         if (!acpi_device_dir(device)) {
 606                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 607                                                      acpi_power_dir);
 608                 if (!acpi_device_dir(device))
 609                         return -ENODEV;
 610         }
 611
 612         /* 'status' [R] */
 613         entry = proc_create_data(ACPI_POWER_FILE_STATUS,
 614                                  S_IRUGO, acpi_device_dir(device),
 615                                  &acpi_power_fops, acpi_driver_data(device));
 616         if (!entry)
 617                 return -EIO;
 618         return 0;
 619 }
 620
 621 static int acpi_power_remove_fs(struct acpi_device *device)
 622 {
 623
 624         if (acpi_device_dir(device)) {
 625                 remove_proc_entry(ACPI_POWER_FILE_STATUS,
 626                                   acpi_device_dir(device));
 627                 remove_proc_entry(acpi_device_bid(device), acpi_power_dir);
 628                 acpi_device_dir(device) = NULL;
 629         }
 630
 631         return 0;
 632 }
 633
 634 /* --------------------------------------------------------------------------
 635                                 Driver Interface
 636    -------------------------------------------------------------------------- */
 637
 638 static int acpi_power_add(struct acpi_device *device)
 639 {
 640         int result = 0, state;
 641         acpi_status status = AE_OK;
 642         struct acpi_power_resource *resource = NULL;
 643         union acpi_object acpi_object;
 644         struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
 645
 646
 647         if (!device)
 648                 return -EINVAL;
 649
 650         resource = kzalloc(sizeof(struct acpi_power_resource), GFP_KERNEL);
 651         if (!resource)
 652                 return -ENOMEM;
 653
 654         resource->device = device;
 655         mutex_init(&resource->resource_lock);
 656         INIT_LIST_HEAD(&resource->reference);
 657         strcpy(resource->name, device->pnp.bus_id);
 658         strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
 659         strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
 660         acpi_driver_data(device) = resource;
 661
 662         /* Evalute the object to get the system level and resource order. */
 663         status = acpi_evaluate_object(device->handle, NULL, NULL, &buffer);
 664         if (ACPI_FAILURE(status)) {
 665                 result = -ENODEV;
 666                 goto end;
 667         }
 668         resource->system_level = acpi_object.power_resource.system_level;
 669         resource->order = acpi_object.power_resource.resource_order;
 670
 671         result = acpi_power_get_state(resource, &state);
 672         if (result)
 673                 goto end;
 674
 675         switch (state) {
 676         case ACPI_POWER_RESOURCE_STATE_ON:
 677                 device->power.state = ACPI_STATE_D0;
 678                 break;
 679         case ACPI_POWER_RESOURCE_STATE_OFF:
 680                 device->power.state = ACPI_STATE_D3;
 681                 break;
 682         default:
 683                 device->power.state = ACPI_STATE_UNKNOWN;
 684                 break;
 685         }
 686
 687         result = acpi_power_add_fs(device);
 688         if (result)
 689                 goto end;
 690
 691         printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
 692                acpi_device_bid(device), state ? "on" : "off");
 693
 694       end:
 695         if (result)
 696                 kfree(resource);
 697
 698         return result;
 699 }
 700
 701 static int acpi_power_remove(struct acpi_device *device, int type)
 702 {
 703         struct acpi_power_resource *resource = NULL;
 704         struct list_head *node, *next;
 705
 706
 707         if (!device || !acpi_driver_data(device))
 708                 return -EINVAL;
 709
 710         resource = acpi_driver_data(device);
 711
 712         acpi_power_remove_fs(device);
 713
 714         mutex_lock(&resource->resource_lock);
 715         list_for_each_safe(node, next, &resource->reference) {
 716                 struct acpi_power_reference *ref = container_of(node, struct acpi_power_reference, node);
 717                 list_del(&ref->node);
 718                 kfree(ref);
 719         }
 720         mutex_unlock(&resource->resource_lock);
 721
 722         kfree(resource);
 723
 724         return 0;
 725 }
 726
 727 static int acpi_power_resume(struct acpi_device *device)
 728 {
 729         int result = 0, state;
 730         struct acpi_power_resource *resource = NULL;
 731         struct acpi_power_reference *ref;
 732
 733         if (!device || !acpi_driver_data(device))
 734                 return -EINVAL;
 735
 736         resource = (struct acpi_power_resource *)acpi_driver_data(device);
 737
 738         result = acpi_power_get_state(resource, &state);
 739         if (result)
 740                 return result;
 741
 742         mutex_lock(&resource->resource_lock);
 743         if (state == ACPI_POWER_RESOURCE_STATE_OFF &&
 744             !list_empty(&resource->reference)) {
 745                 ref = container_of(resource->reference.next, struct acpi_power_reference, node);
 746                 mutex_unlock(&resource->resource_lock);
 747                 result = acpi_power_on(device->handle, ref->device);
 748                 return result;
 749         }
 750
 751         mutex_unlock(&resource->resource_lock);
 752         return 0;
 753 }
 754
 755 static int __init acpi_power_init(void)
 756 {
 757         int result = 0;
 758
 759
 760         if (acpi_disabled)
 761                 return 0;
 762
 763         INIT_LIST_HEAD(&acpi_power_resource_list);
 764
 765         acpi_power_dir = proc_mkdir(ACPI_POWER_CLASS, acpi_root_dir);
 766         if (!acpi_power_dir)
 767                 return -ENODEV;
 768
 769         result = acpi_bus_register_driver(&acpi_power_driver);
 770         if (result < 0) {
 771                 remove_proc_entry(ACPI_POWER_CLASS, acpi_root_dir);
 772                 return -ENODEV;
 773         }
 774
 775         return 0;
 776 }
 777
 778 subsys_initcall(acpi_power_init);