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