drivers/acpi/power.c

   1 /*
   2  *  acpi_power.c - ACPI Bus Power Management ($Revision: 39 $)
   3  *
   4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6  *
   7  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License as published by
  11  *  the Free Software Foundation; either version 2 of the License, or (at
  12  *  your option) any later version.
  13  *
  14  *  This program is distributed in the hope that it will be useful, but
  15  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  *  General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License along
  20  *  with this program; if not, write to the Free Software Foundation, Inc.,
  21  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  22  *
  23  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  24  */
  25
  26 /*
  27  * ACPI power-managed devices may be controlled in two ways:
  28  * 1. via "Device Specific (D-State) Control"
  29  * 2. via "Power Resource Control".
  30  * This module is used to manage devices relying on Power Resource Control.
  31  *
  32  * An ACPI "power resource object" describes a software controllable power
  33  * plane, clock plane, or other resource used by a power managed device.
  34  * A device may rely on multiple power resources, and a power resource
  35  * may be shared by multiple devices.
  36  */
  37
  38 #include <linux/kernel.h>
  39 #include <linux/module.h>
  40 #include <linux/init.h>
  41 #include <linux/types.h>
  42 #include <linux/slab.h>
  43 #include <linux/pm_runtime.h>
  44 #include <acpi/acpi_bus.h>
  45 #include <acpi/acpi_drivers.h>
  46 #include "sleep.h"
  47 #include "internal.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 static int acpi_power_add(struct acpi_device *device);
  62 static int acpi_power_remove(struct acpi_device *device, int type);
  63
  64 static const struct acpi_device_id power_device_ids[] = {
  65         {ACPI_POWER_HID, 0},
  66         {"", 0},
  67 };
  68 MODULE_DEVICE_TABLE(acpi, power_device_ids);
  69
  70 static int acpi_power_resume(struct device *dev);
  71 static SIMPLE_DEV_PM_OPS(acpi_power_pm, NULL, acpi_power_resume);
  72
  73 static struct acpi_driver acpi_power_driver = {
  74         .name = "power",
  75         .class = ACPI_POWER_CLASS,
  76         .ids = power_device_ids,
  77         .ops = {
  78                 .add = acpi_power_add,
  79                 .remove = acpi_power_remove,
  80                 },
  81         .drv.pm = &acpi_power_pm,
  82 };
  83
  84 /*
  85  * A power managed device
  86  * A device may rely on multiple power resources.
  87  * */
  88 struct acpi_power_managed_device {
  89         struct device *dev; /* The physical device */
  90         acpi_handle *handle;
  91 };
  92
  93 struct acpi_power_resource_device {
  94         struct acpi_power_managed_device *device;
  95         struct acpi_power_resource_device *next;
  96 };
  97
  98 struct acpi_power_resource {
  99         struct acpi_device * device;
 100         acpi_bus_id name;
 101         u32 system_level;
 102         u32 order;
 103         unsigned int ref_count;
 104         struct mutex resource_lock;
 105
 106         /* List of devices relying on this power resource */
 107         struct acpi_power_resource_device *devices;
 108 };
 109
 110 static struct list_head acpi_power_resource_list;
 111
 112 /* --------------------------------------------------------------------------
 113                              Power Resource Management
 114    -------------------------------------------------------------------------- */
 115
 116 static int
 117 acpi_power_get_context(acpi_handle handle,
 118                        struct acpi_power_resource **resource)
 119 {
 120         int result = 0;
 121         struct acpi_device *device = NULL;
 122
 123
 124         if (!resource)
 125                 return -ENODEV;
 126
 127         result = acpi_bus_get_device(handle, &device);
 128         if (result) {
 129                 printk(KERN_WARNING PREFIX "Getting context [%p]\n", handle);
 130                 return result;
 131         }
 132
 133         *resource = acpi_driver_data(device);
 134         if (!*resource)
 135                 return -ENODEV;
 136
 137         return 0;
 138 }
 139
 140 static int acpi_power_get_state(acpi_handle handle, int *state)
 141 {
 142         acpi_status status = AE_OK;
 143         unsigned long long sta = 0;
 144         char node_name[5];
 145         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 146
 147
 148         if (!handle || !state)
 149                 return -EINVAL;
 150
 151         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 152         if (ACPI_FAILURE(status))
 153                 return -ENODEV;
 154
 155         *state = (sta & 0x01)?ACPI_POWER_RESOURCE_STATE_ON:
 156                               ACPI_POWER_RESOURCE_STATE_OFF;
 157
 158         acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 159
 160         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
 161                           node_name,
 162                                 *state ? "on" : "off"));
 163
 164         return 0;
 165 }
 166
 167 static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
 168 {
 169         int cur_state;
 170         int i = 0;
 171
 172         if (!list || !state)
 173                 return -EINVAL;
 174
 175         /* The state of the list is 'on' IFF all resources are 'on'. */
 176
 177         for (i = 0; i < list->count; i++) {
 178                 struct acpi_power_resource *resource;
 179                 acpi_handle handle = list->handles[i];
 180                 int result;
 181
 182                 result = acpi_power_get_context(handle, &resource);
 183                 if (result)
 184                         return result;
 185
 186                 mutex_lock(&resource->resource_lock);
 187
 188                 result = acpi_power_get_state(handle, &cur_state);
 189
 190                 mutex_unlock(&resource->resource_lock);
 191
 192                 if (result)
 193                         return result;
 194
 195                 if (cur_state != ACPI_POWER_RESOURCE_STATE_ON)
 196                         break;
 197         }
 198
 199         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
 200                           cur_state ? "on" : "off"));
 201
 202         *state = cur_state;
 203
 204         return 0;
 205 }
 206
 207 /* Resume the device when all power resources in _PR0 are on */
 208 static void acpi_power_on_device(struct acpi_power_managed_device *device)
 209 {
 210         struct acpi_device *acpi_dev;
 211         acpi_handle handle = device->handle;
 212         int state;
 213
 214         if (acpi_bus_get_device(handle, &acpi_dev))
 215                 return;
 216
 217         if(acpi_power_get_inferred_state(acpi_dev, &state))
 218                 return;
 219
 220         if (state == ACPI_STATE_D0 && pm_runtime_suspended(device->dev))
 221                 pm_request_resume(device->dev);
 222 }
 223
 224 static int __acpi_power_on(struct acpi_power_resource *resource)
 225 {
 226         struct acpi_power_resource_device *device_list = resource->devices;
 227         acpi_status status = AE_OK;
 228
 229         status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL);
 230         if (ACPI_FAILURE(status))
 231                 return -ENODEV;
 232
 233         /* Update the power resource's _device_ power state */
 234         resource->device->power.state = ACPI_STATE_D0;
 235
 236         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned on\n",
 237                           resource->name));
 238
 239         while (device_list) {
 240                 acpi_power_on_device(device_list->device);
 241
 242                 device_list = device_list->next;
 243         }
 244
 245         return 0;
 246 }
 247
 248 static int acpi_power_on(acpi_handle handle)
 249 {
 250         int result = 0;
 251         struct acpi_power_resource *resource = NULL;
 252
 253         result = acpi_power_get_context(handle, &resource);
 254         if (result)
 255                 return result;
 256
 257         mutex_lock(&resource->resource_lock);
 258
 259         if (resource->ref_count++) {
 260                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 261                                   "Power resource [%s] already on",
 262                                   resource->name));
 263         } else {
 264                 result = __acpi_power_on(resource);
 265                 if (result)
 266                         resource->ref_count--;
 267         }
 268
 269         mutex_unlock(&resource->resource_lock);
 270
 271         return result;
 272 }
 273
 274 static int acpi_power_off(acpi_handle handle)
 275 {
 276         int result = 0;
 277         acpi_status status = AE_OK;
 278         struct acpi_power_resource *resource = NULL;
 279
 280         result = acpi_power_get_context(handle, &resource);
 281         if (result)
 282                 return result;
 283
 284         mutex_lock(&resource->resource_lock);
 285
 286         if (!resource->ref_count) {
 287                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 288                                   "Power resource [%s] already off",
 289                                   resource->name));
 290                 goto unlock;
 291         }
 292
 293         if (--resource->ref_count) {
 294                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 295                                   "Power resource [%s] still in use\n",
 296                                   resource->name));
 297                 goto unlock;
 298         }
 299
 300         status = acpi_evaluate_object(resource->device->handle, "_OFF", NULL, NULL);
 301         if (ACPI_FAILURE(status)) {
 302                 result = -ENODEV;
 303         } else {
 304                 /* Update the power resource's _device_ power state */
 305                 resource->device->power.state = ACPI_STATE_D3;
 306
 307                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 308                                   "Power resource [%s] turned off\n",
 309                                   resource->name));
 310         }
 311
 312  unlock:
 313         mutex_unlock(&resource->resource_lock);
 314
 315         return result;
 316 }
 317
 318 static void __acpi_power_off_list(struct acpi_handle_list *list, int num_res)
 319 {
 320         int i;
 321
 322         for (i = num_res - 1; i >= 0 ; i--)
 323                 acpi_power_off(list->handles[i]);
 324 }
 325
 326 static void acpi_power_off_list(struct acpi_handle_list *list)
 327 {
 328         __acpi_power_off_list(list, list->count);
 329 }
 330
 331 static int acpi_power_on_list(struct acpi_handle_list *list)
 332 {
 333         int result = 0;
 334         int i;
 335
 336         for (i = 0; i < list->count; i++) {
 337                 result = acpi_power_on(list->handles[i]);
 338                 if (result) {
 339                         __acpi_power_off_list(list, i);
 340                         break;
 341                 }
 342         }
 343
 344         return result;
 345 }
 346
 347 static void __acpi_power_resource_unregister_device(struct device *dev,
 348                 acpi_handle res_handle)
 349 {
 350         struct acpi_power_resource *resource = NULL;
 351         struct acpi_power_resource_device *prev, *curr;
 352
 353         if (acpi_power_get_context(res_handle, &resource))
 354                 return;
 355
 356         mutex_lock(&resource->resource_lock);
 357         prev = NULL;
 358         curr = resource->devices;
 359         while (curr) {
 360                 if (curr->device->dev == dev) {
 361                         if (!prev)
 362                                 resource->devices = curr->next;
 363                         else
 364                                 prev->next = curr->next;
 365
 366                         kfree(curr);
 367                         break;
 368                 }
 369
 370                 prev = curr;
 371                 curr = curr->next;
 372         }
 373         mutex_unlock(&resource->resource_lock);
 374 }
 375
 376 /* Unlink dev from all power resources in _PR0 */
 377 void acpi_power_resource_unregister_device(struct device *dev, acpi_handle handle)
 378 {
 379         struct acpi_device *acpi_dev;
 380         struct acpi_handle_list *list;
 381         int i;
 382
 383         if (!dev || !handle)
 384                 return;
 385
 386         if (acpi_bus_get_device(handle, &acpi_dev))
 387                 return;
 388
 389         list = &acpi_dev->power.states[ACPI_STATE_D0].resources;
 390
 391         for (i = 0; i < list->count; i++)
 392                 __acpi_power_resource_unregister_device(dev,
 393                         list->handles[i]);
 394 }
 395 EXPORT_SYMBOL_GPL(acpi_power_resource_unregister_device);
 396
 397 static int __acpi_power_resource_register_device(
 398         struct acpi_power_managed_device *powered_device, acpi_handle handle)
 399 {
 400         struct acpi_power_resource *resource = NULL;
 401         struct acpi_power_resource_device *power_resource_device;
 402         int result;
 403
 404         result = acpi_power_get_context(handle, &resource);
 405         if (result)
 406                 return result;
 407
 408         power_resource_device = kzalloc(
 409                 sizeof(*power_resource_device), GFP_KERNEL);
 410         if (!power_resource_device)
 411                 return -ENOMEM;
 412
 413         power_resource_device->device = powered_device;
 414
 415         mutex_lock(&resource->resource_lock);
 416         power_resource_device->next = resource->devices;
 417         resource->devices = power_resource_device;
 418         mutex_unlock(&resource->resource_lock);
 419
 420         return 0;
 421 }
 422
 423 /* Link dev to all power resources in _PR0 */
 424 int acpi_power_resource_register_device(struct device *dev, acpi_handle handle)
 425 {
 426         struct acpi_device *acpi_dev;
 427         struct acpi_handle_list *list;
 428         struct acpi_power_managed_device *powered_device;
 429         int i, ret;
 430
 431         if (!dev || !handle)
 432                 return -ENODEV;
 433
 434         ret = acpi_bus_get_device(handle, &acpi_dev);
 435         if (ret)
 436                 goto no_power_resource;
 437
 438         if (!acpi_dev->power.flags.power_resources)
 439                 goto no_power_resource;
 440
 441         powered_device = kzalloc(sizeof(*powered_device), GFP_KERNEL);
 442         if (!powered_device)
 443                 return -ENOMEM;
 444
 445         powered_device->dev = dev;
 446         powered_device->handle = handle;
 447
 448         list = &acpi_dev->power.states[ACPI_STATE_D0].resources;
 449
 450         for (i = 0; i < list->count; i++) {
 451                 ret = __acpi_power_resource_register_device(powered_device,
 452                         list->handles[i]);
 453
 454                 if (ret) {
 455                         acpi_power_resource_unregister_device(dev, handle);
 456                         break;
 457                 }
 458         }
 459
 460         return ret;
 461
 462 no_power_resource:
 463         printk(KERN_WARNING PREFIX "Invalid Power Resource to register!");
 464         return -ENODEV;
 465 }
 466 EXPORT_SYMBOL_GPL(acpi_power_resource_register_device);
 467
 468 /**
 469  * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
 470  *                          ACPI 3.0) _PSW (Power State Wake)
 471  * @dev: Device to handle.
 472  * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
 473  * @sleep_state: Target sleep state of the system.
 474  * @dev_state: Target power state of the device.
 475  *
 476  * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 477  * State Wake) for the device, if present.  On failure reset the device's
 478  * wakeup.flags.valid flag.
 479  *
 480  * RETURN VALUE:
 481  * 0 if either _DSW or _PSW has been successfully executed
 482  * 0 if neither _DSW nor _PSW has been found
 483  * -ENODEV if the execution of either _DSW or _PSW has failed
 484  */
 485 int acpi_device_sleep_wake(struct acpi_device *dev,
 486                            int enable, int sleep_state, int dev_state)
 487 {
 488         union acpi_object in_arg[3];
 489         struct acpi_object_list arg_list = { 3, in_arg };
 490         acpi_status status = AE_OK;
 491
 492         /*
 493          * Try to execute _DSW first.
 494          *
 495          * Three agruments are needed for the _DSW object:
 496          * Argument 0: enable/disable the wake capabilities
 497          * Argument 1: target system state
 498          * Argument 2: target device state
 499          * When _DSW object is called to disable the wake capabilities, maybe
 500          * the first argument is filled. The values of the other two agruments
 501          * are meaningless.
 502          */
 503         in_arg[0].type = ACPI_TYPE_INTEGER;
 504         in_arg[0].integer.value = enable;
 505         in_arg[1].type = ACPI_TYPE_INTEGER;
 506         in_arg[1].integer.value = sleep_state;
 507         in_arg[2].type = ACPI_TYPE_INTEGER;
 508         in_arg[2].integer.value = dev_state;
 509         status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
 510         if (ACPI_SUCCESS(status)) {
 511                 return 0;
 512         } else if (status != AE_NOT_FOUND) {
 513                 printk(KERN_ERR PREFIX "_DSW execution failed\n");
 514                 dev->wakeup.flags.valid = 0;
 515                 return -ENODEV;
 516         }
 517
 518         /* Execute _PSW */
 519         arg_list.count = 1;
 520         in_arg[0].integer.value = enable;
 521         status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
 522         if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
 523                 printk(KERN_ERR PREFIX "_PSW execution failed\n");
 524                 dev->wakeup.flags.valid = 0;
 525                 return -ENODEV;
 526         }
 527
 528         return 0;
 529 }
 530
 531 /*
 532  * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
 533  * 1. Power on the power resources required for the wakeup device
 534  * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 535  *    State Wake) for the device, if present
 536  */
 537 int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
 538 {
 539         int i, err = 0;
 540
 541         if (!dev || !dev->wakeup.flags.valid)
 542                 return -EINVAL;
 543
 544         mutex_lock(&acpi_device_lock);
 545
 546         if (dev->wakeup.prepare_count++)
 547                 goto out;
 548
 549         /* Open power resource */
 550         for (i = 0; i < dev->wakeup.resources.count; i++) {
 551                 int ret = acpi_power_on(dev->wakeup.resources.handles[i]);
 552                 if (ret) {
 553                         printk(KERN_ERR PREFIX "Transition power state\n");
 554                         dev->wakeup.flags.valid = 0;
 555                         err = -ENODEV;
 556                         goto err_out;
 557                 }
 558         }
 559
 560         /*
 561          * Passing 3 as the third argument below means the device may be placed
 562          * in arbitrary power state afterwards.
 563          */
 564         err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
 565
 566  err_out:
 567         if (err)
 568                 dev->wakeup.prepare_count = 0;
 569
 570  out:
 571         mutex_unlock(&acpi_device_lock);
 572         return err;
 573 }
 574
 575 /*
 576  * Shutdown a wakeup device, counterpart of above method
 577  * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 578  *    State Wake) for the device, if present
 579  * 2. Shutdown down the power resources
 580  */
 581 int acpi_disable_wakeup_device_power(struct acpi_device *dev)
 582 {
 583         int i, err = 0;
 584
 585         if (!dev || !dev->wakeup.flags.valid)
 586                 return -EINVAL;
 587
 588         mutex_lock(&acpi_device_lock);
 589
 590         if (--dev->wakeup.prepare_count > 0)
 591                 goto out;
 592
 593         /*
 594          * Executing the code below even if prepare_count is already zero when
 595          * the function is called may be useful, for example for initialisation.
 596          */
 597         if (dev->wakeup.prepare_count < 0)
 598                 dev->wakeup.prepare_count = 0;
 599
 600         err = acpi_device_sleep_wake(dev, 0, 0, 0);
 601         if (err)
 602                 goto out;
 603
 604         /* Close power resource */
 605         for (i = 0; i < dev->wakeup.resources.count; i++) {
 606                 int ret = acpi_power_off(dev->wakeup.resources.handles[i]);
 607                 if (ret) {
 608                         printk(KERN_ERR PREFIX "Transition power state\n");
 609                         dev->wakeup.flags.valid = 0;
 610                         err = -ENODEV;
 611                         goto out;
 612                 }
 613         }
 614
 615  out:
 616         mutex_unlock(&acpi_device_lock);
 617         return err;
 618 }
 619
 620 /* --------------------------------------------------------------------------
 621                              Device Power Management
 622    -------------------------------------------------------------------------- */
 623
 624 int acpi_power_get_inferred_state(struct acpi_device *device, int *state)
 625 {
 626         int result = 0;
 627         struct acpi_handle_list *list = NULL;
 628         int list_state = 0;
 629         int i = 0;
 630
 631         if (!device || !state)
 632                 return -EINVAL;
 633
 634         /*
 635          * We know a device's inferred power state when all the resources
 636          * required for a given D-state are 'on'.
 637          */
 638         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
 639                 list = &device->power.states[i].resources;
 640                 if (list->count < 1)
 641                         continue;
 642
 643                 result = acpi_power_get_list_state(list, &list_state);
 644                 if (result)
 645                         return result;
 646
 647                 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
 648                         *state = i;
 649                         return 0;
 650                 }
 651         }
 652
 653         *state = ACPI_STATE_D3;
 654         return 0;
 655 }
 656
 657 int acpi_power_on_resources(struct acpi_device *device, int state)
 658 {
 659         if (!device || state < ACPI_STATE_D0 || state > ACPI_STATE_D3)
 660                 return -EINVAL;
 661
 662         return acpi_power_on_list(&device->power.states[state].resources);
 663 }
 664
 665 int acpi_power_transition(struct acpi_device *device, int state)
 666 {
 667         int result = 0;
 668
 669         if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
 670                 return -EINVAL;
 671
 672         if (device->power.state == state)
 673                 return 0;
 674
 675         if ((device->power.state < ACPI_STATE_D0)
 676             || (device->power.state > ACPI_STATE_D3_COLD))
 677                 return -ENODEV;
 678
 679         /* TBD: Resources must be ordered. */
 680
 681         /*
 682          * First we reference all power resources required in the target list
 683          * (e.g. so the device doesn't lose power while transitioning).  Then,
 684          * we dereference all power resources used in the current list.
 685          */
 686         if (state < ACPI_STATE_D3_COLD)
 687                 result = acpi_power_on_list(
 688                         &device->power.states[state].resources);
 689
 690         if (!result && device->power.state < ACPI_STATE_D3_COLD)
 691                 acpi_power_off_list(
 692                         &device->power.states[device->power.state].resources);
 693
 694         /* We shouldn't change the state unless the above operations succeed. */
 695         device->power.state = result ? ACPI_STATE_UNKNOWN : state;
 696
 697         return result;
 698 }
 699
 700 /* --------------------------------------------------------------------------
 701                                 Driver Interface
 702    -------------------------------------------------------------------------- */
 703
 704 static int acpi_power_add(struct acpi_device *device)
 705 {
 706         int result = 0, state;
 707         acpi_status status = AE_OK;
 708         struct acpi_power_resource *resource = NULL;
 709         union acpi_object acpi_object;
 710         struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
 711
 712
 713         if (!device)
 714                 return -EINVAL;
 715
 716         resource = kzalloc(sizeof(struct acpi_power_resource), GFP_KERNEL);
 717         if (!resource)
 718                 return -ENOMEM;
 719
 720         resource->device = device;
 721         mutex_init(&resource->resource_lock);
 722         strcpy(resource->name, device->pnp.bus_id);
 723         strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
 724         strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
 725         device->driver_data = resource;
 726
 727         /* Evalute the object to get the system level and resource order. */
 728         status = acpi_evaluate_object(device->handle, NULL, NULL, &buffer);
 729         if (ACPI_FAILURE(status)) {
 730                 result = -ENODEV;
 731                 goto end;
 732         }
 733         resource->system_level = acpi_object.power_resource.system_level;
 734         resource->order = acpi_object.power_resource.resource_order;
 735
 736         result = acpi_power_get_state(device->handle, &state);
 737         if (result)
 738                 goto end;
 739
 740         switch (state) {
 741         case ACPI_POWER_RESOURCE_STATE_ON:
 742                 device->power.state = ACPI_STATE_D0;
 743                 break;
 744         case ACPI_POWER_RESOURCE_STATE_OFF:
 745                 device->power.state = ACPI_STATE_D3;
 746                 break;
 747         default:
 748                 device->power.state = ACPI_STATE_UNKNOWN;
 749                 break;
 750         }
 751
 752         printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
 753                acpi_device_bid(device), state ? "on" : "off");
 754
 755       end:
 756         if (result)
 757                 kfree(resource);
 758
 759         return result;
 760 }
 761
 762 static int acpi_power_remove(struct acpi_device *device, int type)
 763 {
 764         struct acpi_power_resource *resource;
 765
 766         if (!device)
 767                 return -EINVAL;
 768
 769         resource = acpi_driver_data(device);
 770         if (!resource)
 771                 return -EINVAL;
 772
 773         kfree(resource);
 774
 775         return 0;
 776 }
 777
 778 static int acpi_power_resume(struct device *dev)
 779 {
 780         int result = 0, state;
 781         struct acpi_device *device;
 782         struct acpi_power_resource *resource;
 783
 784         if (!dev)
 785                 return -EINVAL;
 786
 787         device = to_acpi_device(dev);
 788         resource = acpi_driver_data(device);
 789         if (!resource)
 790                 return -EINVAL;
 791
 792         mutex_lock(&resource->resource_lock);
 793
 794         result = acpi_power_get_state(device->handle, &state);
 795         if (result)
 796                 goto unlock;
 797
 798         if (state == ACPI_POWER_RESOURCE_STATE_OFF && resource->ref_count)
 799                 result = __acpi_power_on(resource);
 800
 801  unlock:
 802         mutex_unlock(&resource->resource_lock);
 803
 804         return result;
 805 }
 806
 807 int __init acpi_power_init(void)
 808 {
 809         INIT_LIST_HEAD(&acpi_power_resource_list);
 810         return acpi_bus_register_driver(&acpi_power_driver);
 811 }