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/proc_fs.h>
  44 #include <linux/seq_file.h>
  45 #include <acpi/acpi_bus.h>
  46 #include <acpi/acpi_drivers.h>
  47 #include "sleep.h"
  48
  49 #define PREFIX "ACPI: "
  50
  51 #define _COMPONENT                      ACPI_POWER_COMPONENT
  52 ACPI_MODULE_NAME("power");
  53 #define ACPI_POWER_CLASS                "power_resource"
  54 #define ACPI_POWER_DEVICE_NAME          "Power Resource"
  55 #define ACPI_POWER_FILE_INFO            "info"
  56 #define ACPI_POWER_FILE_STATUS          "state"
  57 #define ACPI_POWER_RESOURCE_STATE_OFF   0x00
  58 #define ACPI_POWER_RESOURCE_STATE_ON    0x01
  59 #define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF
  60
  61 int acpi_power_nocheck;
  62 module_param_named(power_nocheck, acpi_power_nocheck, bool, 000);
  63
  64 static int acpi_power_add(struct acpi_device *device);
  65 static int acpi_power_remove(struct acpi_device *device, int type);
  66 static int acpi_power_resume(struct acpi_device *device);
  67 static int acpi_power_open_fs(struct inode *inode, struct file *file);
  68
  69 static const struct acpi_device_id power_device_ids[] = {
  70         {ACPI_POWER_HID, 0},
  71         {"", 0},
  72 };
  73 MODULE_DEVICE_TABLE(acpi, power_device_ids);
  74
  75 static struct acpi_driver acpi_power_driver = {
  76         .name = "power",
  77         .class = ACPI_POWER_CLASS,
  78         .ids = power_device_ids,
  79         .ops = {
  80                 .add = acpi_power_add,
  81                 .remove = acpi_power_remove,
  82                 .resume = acpi_power_resume,
  83                 },
  84 };
  85
  86 struct acpi_power_reference {
  87         struct list_head node;
  88         struct acpi_device *device;
  89 };
  90
  91 struct acpi_power_resource {
  92         struct acpi_device * device;
  93         acpi_bus_id name;
  94         u32 system_level;
  95         u32 order;
  96         struct mutex resource_lock;
  97         struct list_head reference;
  98 };
  99
 100 static struct list_head acpi_power_resource_list;
 101
 102 static const struct file_operations acpi_power_fops = {
 103         .owner = THIS_MODULE,
 104         .open = acpi_power_open_fs,
 105         .read = seq_read,
 106         .llseek = seq_lseek,
 107         .release = single_release,
 108 };
 109
 110 /* --------------------------------------------------------------------------
 111                              Power Resource Management
 112    -------------------------------------------------------------------------- */
 113
 114 static int
 115 acpi_power_get_context(acpi_handle handle,
 116                        struct acpi_power_resource **resource)
 117 {
 118         int result = 0;
 119         struct acpi_device *device = NULL;
 120
 121
 122         if (!resource)
 123                 return -ENODEV;
 124
 125         result = acpi_bus_get_device(handle, &device);
 126         if (result) {
 127                 printk(KERN_WARNING PREFIX "Getting context [%p]\n", handle);
 128                 return result;
 129         }
 130
 131         *resource = acpi_driver_data(device);
 132         if (!*resource)
 133                 return -ENODEV;
 134
 135         return 0;
 136 }
 137
 138 static int acpi_power_get_state(acpi_handle handle, int *state)
 139 {
 140         acpi_status status = AE_OK;
 141         unsigned long long sta = 0;
 142         char node_name[5];
 143         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 144
 145
 146         if (!handle || !state)
 147                 return -EINVAL;
 148
 149         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 150         if (ACPI_FAILURE(status))
 151                 return -ENODEV;
 152
 153         *state = (sta & 0x01)?ACPI_POWER_RESOURCE_STATE_ON:
 154                               ACPI_POWER_RESOURCE_STATE_OFF;
 155
 156         acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 157
 158         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
 159                           node_name,
 160                                 *state ? "on" : "off"));
 161
 162         return 0;
 163 }
 164
 165 static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
 166 {
 167         int result = 0, state1;
 168         u32 i = 0;
 169
 170
 171         if (!list || !state)
 172                 return -EINVAL;
 173
 174         /* The state of the list is 'on' IFF all resources are 'on'. */
 175
 176         for (i = 0; i < list->count; i++) {
 177                 /*
 178                  * The state of the power resource can be obtained by
 179                  * using the ACPI handle. In such case it is unnecessary to
 180                  * get the Power resource first and then get its state again.
 181                  */
 182                 result = acpi_power_get_state(list->handles[i], &state1);
 183                 if (result)
 184                         return result;
 185
 186                 *state = state1;
 187
 188                 if (*state != ACPI_POWER_RESOURCE_STATE_ON)
 189                         break;
 190         }
 191
 192         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
 193                           *state ? "on" : "off"));
 194
 195         return result;
 196 }
 197
 198 static int acpi_power_on(acpi_handle handle, struct acpi_device *dev)
 199 {
 200         int result = 0;
 201         int found = 0;
 202         acpi_status status = AE_OK;
 203         struct acpi_power_resource *resource = NULL;
 204         struct list_head *node, *next;
 205         struct acpi_power_reference *ref;
 206
 207
 208         result = acpi_power_get_context(handle, &resource);
 209         if (result)
 210                 return result;
 211
 212         mutex_lock(&resource->resource_lock);
 213         list_for_each_safe(node, next, &resource->reference) {
 214                 ref = container_of(node, struct acpi_power_reference, node);
 215                 if (dev->handle == ref->device->handle) {
 216                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] already referenced by resource [%s]\n",
 217                                   dev->pnp.bus_id, resource->name));
 218                         found = 1;
 219                         break;
 220                 }
 221         }
 222
 223         if (!found) {
 224                 ref = kmalloc(sizeof (struct acpi_power_reference),
 225                     irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL);
 226                 if (!ref) {
 227                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "kmalloc() failed\n"));
 228                         mutex_unlock(&resource->resource_lock);
 229                         return -ENOMEM;
 230                 }
 231                 list_add_tail(&ref->node, &resource->reference);
 232                 ref->device = dev;
 233                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] added to resource [%s] references\n",
 234                           dev->pnp.bus_id, resource->name));
 235         }
 236         mutex_unlock(&resource->resource_lock);
 237
 238         status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL);
 239         if (ACPI_FAILURE(status))
 240                 return -ENODEV;
 241
 242         /* Update the power resource's _device_ power state */
 243         resource->device->power.state = ACPI_STATE_D0;
 244
 245         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned on\n",
 246                           resource->name));
 247         return 0;
 248 }
 249
 250 static int acpi_power_off_device(acpi_handle handle, struct acpi_device *dev)
 251 {
 252         int result = 0;
 253         acpi_status status = AE_OK;
 254         struct acpi_power_resource *resource = NULL;
 255         struct list_head *node, *next;
 256         struct acpi_power_reference *ref;
 257
 258
 259         result = acpi_power_get_context(handle, &resource);
 260         if (result)
 261                 return result;
 262
 263         mutex_lock(&resource->resource_lock);
 264         list_for_each_safe(node, next, &resource->reference) {
 265                 ref = container_of(node, struct acpi_power_reference, node);
 266                 if (dev->handle == ref->device->handle) {
 267                         list_del(&ref->node);
 268                         kfree(ref);
 269                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] removed from resource [%s] references\n",
 270                             dev->pnp.bus_id, resource->name));
 271                         break;
 272                 }
 273         }
 274
 275         if (!list_empty(&resource->reference)) {
 276                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Cannot turn resource [%s] off - resource is in use\n",
 277                     resource->name));
 278                 mutex_unlock(&resource->resource_lock);
 279                 return 0;
 280         }
 281         mutex_unlock(&resource->resource_lock);
 282
 283         status = acpi_evaluate_object(resource->device->handle, "_OFF", NULL, NULL);
 284         if (ACPI_FAILURE(status))
 285                 return -ENODEV;
 286
 287         /* Update the power resource's _device_ power state */
 288         resource->device->power.state = ACPI_STATE_D3;
 289
 290         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned off\n",
 291                           resource->name));
 292
 293         return 0;
 294 }
 295
 296 /**
 297  * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
 298  *                          ACPI 3.0) _PSW (Power State Wake)
 299  * @dev: Device to handle.
 300  * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
 301  * @sleep_state: Target sleep state of the system.
 302  * @dev_state: Target power state of the device.
 303  *
 304  * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 305  * State Wake) for the device, if present.  On failure reset the device's
 306  * wakeup.flags.valid flag.
 307  *
 308  * RETURN VALUE:
 309  * 0 if either _DSW or _PSW has been successfully executed
 310  * 0 if neither _DSW nor _PSW has been found
 311  * -ENODEV if the execution of either _DSW or _PSW has failed
 312  */
 313 int acpi_device_sleep_wake(struct acpi_device *dev,
 314                            int enable, int sleep_state, int dev_state)
 315 {
 316         union acpi_object in_arg[3];
 317         struct acpi_object_list arg_list = { 3, in_arg };
 318         acpi_status status = AE_OK;
 319
 320         /*
 321          * Try to execute _DSW first.
 322          *
 323          * Three agruments are needed for the _DSW object:
 324          * Argument 0: enable/disable the wake capabilities
 325          * Argument 1: target system state
 326          * Argument 2: target device state
 327          * When _DSW object is called to disable the wake capabilities, maybe
 328          * the first argument is filled. The values of the other two agruments
 329          * are meaningless.
 330          */
 331         in_arg[0].type = ACPI_TYPE_INTEGER;
 332         in_arg[0].integer.value = enable;
 333         in_arg[1].type = ACPI_TYPE_INTEGER;
 334         in_arg[1].integer.value = sleep_state;
 335         in_arg[2].type = ACPI_TYPE_INTEGER;
 336         in_arg[2].integer.value = dev_state;
 337         status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
 338         if (ACPI_SUCCESS(status)) {
 339                 return 0;
 340         } else if (status != AE_NOT_FOUND) {
 341                 printk(KERN_ERR PREFIX "_DSW execution failed\n");
 342                 dev->wakeup.flags.valid = 0;
 343                 return -ENODEV;
 344         }
 345
 346         /* Execute _PSW */
 347         arg_list.count = 1;
 348         in_arg[0].integer.value = enable;
 349         status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
 350         if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
 351                 printk(KERN_ERR PREFIX "_PSW execution failed\n");
 352                 dev->wakeup.flags.valid = 0;
 353                 return -ENODEV;
 354         }
 355
 356         return 0;
 357 }
 358
 359 /*
 360  * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
 361  * 1. Power on the power resources required for the wakeup device
 362  * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 363  *    State Wake) for the device, if present
 364  */
 365 int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
 366 {
 367         int i, err = 0;
 368
 369         if (!dev || !dev->wakeup.flags.valid)
 370                 return -EINVAL;
 371
 372         mutex_lock(&acpi_device_lock);
 373
 374         if (dev->wakeup.prepare_count++)
 375                 goto out;
 376
 377         /* Open power resource */
 378         for (i = 0; i < dev->wakeup.resources.count; i++) {
 379                 int ret = acpi_power_on(dev->wakeup.resources.handles[i], dev);
 380                 if (ret) {
 381                         printk(KERN_ERR PREFIX "Transition power state\n");
 382                         dev->wakeup.flags.valid = 0;
 383                         err = -ENODEV;
 384                         goto err_out;
 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
 394  err_out:
 395         if (err)
 396                 dev->wakeup.prepare_count = 0;
 397
 398  out:
 399         mutex_unlock(&acpi_device_lock);
 400         return err;
 401 }
 402
 403 /*
 404  * Shutdown a wakeup device, counterpart of above method
 405  * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 406  *    State Wake) for the device, if present
 407  * 2. Shutdown down the power resources
 408  */
 409 int acpi_disable_wakeup_device_power(struct acpi_device *dev)
 410 {
 411         int i, err = 0;
 412
 413         if (!dev || !dev->wakeup.flags.valid)
 414                 return -EINVAL;
 415
 416         mutex_lock(&acpi_device_lock);
 417
 418         if (--dev->wakeup.prepare_count > 0)
 419                 goto out;
 420
 421         /*
 422          * Executing the code below even if prepare_count is already zero when
 423          * the function is called may be useful, for example for initialisation.
 424          */
 425         if (dev->wakeup.prepare_count < 0)
 426                 dev->wakeup.prepare_count = 0;
 427
 428         err = acpi_device_sleep_wake(dev, 0, 0, 0);
 429         if (err)
 430                 goto out;
 431
 432         /* Close power resource */
 433         for (i = 0; i < dev->wakeup.resources.count; i++) {
 434                 int ret = acpi_power_off_device(
 435                                 dev->wakeup.resources.handles[i], dev);
 436                 if (ret) {
 437                         printk(KERN_ERR PREFIX "Transition power state\n");
 438                         dev->wakeup.flags.valid = 0;
 439                         err = -ENODEV;
 440                         goto out;
 441                 }
 442         }
 443
 444  out:
 445         mutex_unlock(&acpi_device_lock);
 446         return err;
 447 }
 448
 449 /* --------------------------------------------------------------------------
 450                              Device Power Management
 451    -------------------------------------------------------------------------- */
 452
 453 int acpi_power_get_inferred_state(struct acpi_device *device)
 454 {
 455         int result = 0;
 456         struct acpi_handle_list *list = NULL;
 457         int list_state = 0;
 458         int i = 0;
 459
 460
 461         if (!device)
 462                 return -EINVAL;
 463
 464         device->power.state = ACPI_STATE_UNKNOWN;
 465
 466         /*
 467          * We know a device's inferred power state when all the resources
 468          * required for a given D-state are 'on'.
 469          */
 470         for (i = ACPI_STATE_D0; i < ACPI_STATE_D3; i++) {
 471                 list = &device->power.states[i].resources;
 472                 if (list->count < 1)
 473                         continue;
 474
 475                 result = acpi_power_get_list_state(list, &list_state);
 476                 if (result)
 477                         return result;
 478
 479                 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
 480                         device->power.state = i;
 481                         return 0;
 482                 }
 483         }
 484
 485         device->power.state = ACPI_STATE_D3;
 486
 487         return 0;
 488 }
 489
 490 int acpi_power_transition(struct acpi_device *device, int state)
 491 {
 492         int result = 0;
 493         struct acpi_handle_list *cl = NULL;     /* Current Resources */
 494         struct acpi_handle_list *tl = NULL;     /* Target Resources */
 495         int i = 0;
 496
 497
 498         if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
 499                 return -EINVAL;
 500
 501         if ((device->power.state < ACPI_STATE_D0)
 502             || (device->power.state > ACPI_STATE_D3))
 503                 return -ENODEV;
 504
 505         cl = &device->power.states[device->power.state].resources;
 506         tl = &device->power.states[state].resources;
 507
 508         /* TBD: Resources must be ordered. */
 509
 510         /*
 511          * First we reference all power resources required in the target list
 512          * (e.g. so the device doesn't lose power while transitioning).
 513          */
 514         for (i = 0; i < tl->count; i++) {
 515                 result = acpi_power_on(tl->handles[i], device);
 516                 if (result)
 517                         goto end;
 518         }
 519
 520         if (device->power.state == state) {
 521                 goto end;
 522         }
 523
 524         /*
 525          * Then we dereference all power resources used in the current list.
 526          */
 527         for (i = 0; i < cl->count; i++) {
 528                 result = acpi_power_off_device(cl->handles[i], device);
 529                 if (result)
 530                         goto end;
 531         }
 532
 533      end:
 534         if (result)
 535                 device->power.state = ACPI_STATE_UNKNOWN;
 536         else {
 537         /* We shouldn't change the state till all above operations succeed */
 538                 device->power.state = state;
 539         }
 540
 541         return result;
 542 }
 543
 544 /* --------------------------------------------------------------------------
 545                               FS Interface (/proc)
 546    -------------------------------------------------------------------------- */
 547
 548 static struct proc_dir_entry *acpi_power_dir;
 549
 550 static int acpi_power_seq_show(struct seq_file *seq, void *offset)
 551 {
 552         int count = 0;
 553         int result = 0, state;
 554         struct acpi_power_resource *resource = NULL;
 555         struct list_head *node, *next;
 556         struct acpi_power_reference *ref;
 557
 558
 559         resource = seq->private;
 560
 561         if (!resource)
 562                 goto end;
 563
 564         result = acpi_power_get_state(resource->device->handle, &state);
 565         if (result)
 566                 goto end;
 567
 568         seq_puts(seq, "state:                   ");
 569         switch (state) {
 570         case ACPI_POWER_RESOURCE_STATE_ON:
 571                 seq_puts(seq, "on\n");
 572                 break;
 573         case ACPI_POWER_RESOURCE_STATE_OFF:
 574                 seq_puts(seq, "off\n");
 575                 break;
 576         default:
 577                 seq_puts(seq, "unknown\n");
 578                 break;
 579         }
 580
 581         mutex_lock(&resource->resource_lock);
 582         list_for_each_safe(node, next, &resource->reference) {
 583                 ref = container_of(node, struct acpi_power_reference, node);
 584                 count++;
 585         }
 586         mutex_unlock(&resource->resource_lock);
 587
 588         seq_printf(seq, "system level:            S%d\n"
 589                    "order:                   %d\n"
 590                    "reference count:         %d\n",
 591                    resource->system_level,
 592                    resource->order, count);
 593
 594       end:
 595         return 0;
 596 }
 597
 598 static int acpi_power_open_fs(struct inode *inode, struct file *file)
 599 {
 600         return single_open(file, acpi_power_seq_show, PDE(inode)->data);
 601 }
 602
 603 static int acpi_power_add_fs(struct acpi_device *device)
 604 {
 605         struct proc_dir_entry *entry = NULL;
 606
 607
 608         if (!device)
 609                 return -EINVAL;
 610
 611         if (!acpi_device_dir(device)) {
 612                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 613                                                      acpi_power_dir);
 614                 if (!acpi_device_dir(device))
 615                         return -ENODEV;
 616         }
 617
 618         /* 'status' [R] */
 619         entry = proc_create_data(ACPI_POWER_FILE_STATUS,
 620                                  S_IRUGO, acpi_device_dir(device),
 621                                  &acpi_power_fops, acpi_driver_data(device));
 622         if (!entry)
 623                 return -EIO;
 624         return 0;
 625 }
 626
 627 static int acpi_power_remove_fs(struct acpi_device *device)
 628 {
 629
 630         if (acpi_device_dir(device)) {
 631                 remove_proc_entry(ACPI_POWER_FILE_STATUS,
 632                                   acpi_device_dir(device));
 633                 remove_proc_entry(acpi_device_bid(device), acpi_power_dir);
 634                 acpi_device_dir(device) = NULL;
 635         }
 636
 637         return 0;
 638 }
 639
 640 /* --------------------------------------------------------------------------
 641                                 Driver Interface
 642    -------------------------------------------------------------------------- */
 643
 644 static int acpi_power_add(struct acpi_device *device)
 645 {
 646         int result = 0, state;
 647         acpi_status status = AE_OK;
 648         struct acpi_power_resource *resource = NULL;
 649         union acpi_object acpi_object;
 650         struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
 651
 652
 653         if (!device)
 654                 return -EINVAL;
 655
 656         resource = kzalloc(sizeof(struct acpi_power_resource), GFP_KERNEL);
 657         if (!resource)
 658                 return -ENOMEM;
 659
 660         resource->device = device;
 661         mutex_init(&resource->resource_lock);
 662         INIT_LIST_HEAD(&resource->reference);
 663         strcpy(resource->name, device->pnp.bus_id);
 664         strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
 665         strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
 666         device->driver_data = resource;
 667
 668         /* Evalute the object to get the system level and resource order. */
 669         status = acpi_evaluate_object(device->handle, NULL, NULL, &buffer);
 670         if (ACPI_FAILURE(status)) {
 671                 result = -ENODEV;
 672                 goto end;
 673         }
 674         resource->system_level = acpi_object.power_resource.system_level;
 675         resource->order = acpi_object.power_resource.resource_order;
 676
 677         result = acpi_power_get_state(device->handle, &state);
 678         if (result)
 679                 goto end;
 680
 681         switch (state) {
 682         case ACPI_POWER_RESOURCE_STATE_ON:
 683                 device->power.state = ACPI_STATE_D0;
 684                 break;
 685         case ACPI_POWER_RESOURCE_STATE_OFF:
 686                 device->power.state = ACPI_STATE_D3;
 687                 break;
 688         default:
 689                 device->power.state = ACPI_STATE_UNKNOWN;
 690                 break;
 691         }
 692
 693         result = acpi_power_add_fs(device);
 694         if (result)
 695                 goto end;
 696
 697         printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
 698                acpi_device_bid(device), state ? "on" : "off");
 699
 700       end:
 701         if (result)
 702                 kfree(resource);
 703
 704         return result;
 705 }
 706
 707 static int acpi_power_remove(struct acpi_device *device, int type)
 708 {
 709         struct acpi_power_resource *resource = NULL;
 710         struct list_head *node, *next;
 711
 712
 713         if (!device || !acpi_driver_data(device))
 714                 return -EINVAL;
 715
 716         resource = acpi_driver_data(device);
 717
 718         acpi_power_remove_fs(device);
 719
 720         mutex_lock(&resource->resource_lock);
 721         list_for_each_safe(node, next, &resource->reference) {
 722                 struct acpi_power_reference *ref = container_of(node, struct acpi_power_reference, node);
 723                 list_del(&ref->node);
 724                 kfree(ref);
 725         }
 726         mutex_unlock(&resource->resource_lock);
 727
 728         kfree(resource);
 729
 730         return 0;
 731 }
 732
 733 static int acpi_power_resume(struct acpi_device *device)
 734 {
 735         int result = 0, state;
 736         struct acpi_power_resource *resource = NULL;
 737         struct acpi_power_reference *ref;
 738
 739         if (!device || !acpi_driver_data(device))
 740                 return -EINVAL;
 741
 742         resource = acpi_driver_data(device);
 743
 744         result = acpi_power_get_state(device->handle, &state);
 745         if (result)
 746                 return result;
 747
 748         mutex_lock(&resource->resource_lock);
 749         if (state == ACPI_POWER_RESOURCE_STATE_OFF &&
 750             !list_empty(&resource->reference)) {
 751                 ref = container_of(resource->reference.next, struct acpi_power_reference, node);
 752                 mutex_unlock(&resource->resource_lock);
 753                 result = acpi_power_on(device->handle, ref->device);
 754                 return result;
 755         }
 756
 757         mutex_unlock(&resource->resource_lock);
 758         return 0;
 759 }
 760
 761 int __init acpi_power_init(void)
 762 {
 763         int result = 0;
 764
 765         INIT_LIST_HEAD(&acpi_power_resource_list);
 766
 767         acpi_power_dir = proc_mkdir(ACPI_POWER_CLASS, acpi_root_dir);
 768         if (!acpi_power_dir)
 769                 return -ENODEV;
 770
 771         result = acpi_bus_register_driver(&acpi_power_driver);
 772         if (result < 0) {
 773                 remove_proc_entry(ACPI_POWER_CLASS, acpi_root_dir);
 774                 return -ENODEV;
 775         }
 776
 777         return 0;
 778 }