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 <acpi/acpi_bus.h>
  44 #include <acpi/acpi_drivers.h>
  45 #include "sleep.h"
  46
  47 #define PREFIX "ACPI: "
  48
  49 #define _COMPONENT                      ACPI_POWER_COMPONENT
  50 ACPI_MODULE_NAME("power");
  51 #define ACPI_POWER_CLASS                "power_resource"
  52 #define ACPI_POWER_DEVICE_NAME          "Power Resource"
  53 #define ACPI_POWER_FILE_INFO            "info"
  54 #define ACPI_POWER_FILE_STATUS          "state"
  55 #define ACPI_POWER_RESOURCE_STATE_OFF   0x00
  56 #define ACPI_POWER_RESOURCE_STATE_ON    0x01
  57 #define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF
  58
  59 static int acpi_power_add(struct acpi_device *device);
  60 static int acpi_power_remove(struct acpi_device *device, int type);
  61 static int acpi_power_resume(struct acpi_device *device);
  62
  63 static const struct acpi_device_id power_device_ids[] = {
  64         {ACPI_POWER_HID, 0},
  65         {"", 0},
  66 };
  67 MODULE_DEVICE_TABLE(acpi, power_device_ids);
  68
  69 static struct acpi_driver acpi_power_driver = {
  70         .name = "power",
  71         .class = ACPI_POWER_CLASS,
  72         .ids = power_device_ids,
  73         .ops = {
  74                 .add = acpi_power_add,
  75                 .remove = acpi_power_remove,
  76                 .resume = acpi_power_resume,
  77                 },
  78 };
  79
  80 struct acpi_power_resource {
  81         struct acpi_device * device;
  82         acpi_bus_id name;
  83         u32 system_level;
  84         u32 order;
  85         unsigned int ref_count;
  86         struct mutex resource_lock;
  87 };
  88
  89 static struct list_head acpi_power_resource_list;
  90
  91 /* --------------------------------------------------------------------------
  92                              Power Resource Management
  93    -------------------------------------------------------------------------- */
  94
  95 static int
  96 acpi_power_get_context(acpi_handle handle,
  97                        struct acpi_power_resource **resource)
  98 {
  99         int result = 0;
 100         struct acpi_device *device = NULL;
 101
 102
 103         if (!resource)
 104                 return -ENODEV;
 105
 106         result = acpi_bus_get_device(handle, &device);
 107         if (result) {
 108                 printk(KERN_WARNING PREFIX "Getting context [%p]\n", handle);
 109                 return result;
 110         }
 111
 112         *resource = acpi_driver_data(device);
 113         if (!*resource)
 114                 return -ENODEV;
 115
 116         return 0;
 117 }
 118
 119 static int acpi_power_get_state(acpi_handle handle, int *state)
 120 {
 121         acpi_status status = AE_OK;
 122         unsigned long long sta = 0;
 123         char node_name[5];
 124         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 125
 126
 127         if (!handle || !state)
 128                 return -EINVAL;
 129
 130         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 131         if (ACPI_FAILURE(status))
 132                 return -ENODEV;
 133
 134         *state = (sta & 0x01)?ACPI_POWER_RESOURCE_STATE_ON:
 135                               ACPI_POWER_RESOURCE_STATE_OFF;
 136
 137         acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 138
 139         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
 140                           node_name,
 141                                 *state ? "on" : "off"));
 142
 143         return 0;
 144 }
 145
 146 static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
 147 {
 148         int cur_state;
 149         int i = 0;
 150
 151         if (!list || !state)
 152                 return -EINVAL;
 153
 154         /* The state of the list is 'on' IFF all resources are 'on'. */
 155
 156         for (i = 0; i < list->count; i++) {
 157                 struct acpi_power_resource *resource;
 158                 acpi_handle handle = list->handles[i];
 159                 int result;
 160
 161                 result = acpi_power_get_context(handle, &resource);
 162                 if (result)
 163                         return result;
 164
 165                 mutex_lock(&resource->resource_lock);
 166
 167                 result = acpi_power_get_state(handle, &cur_state);
 168
 169                 mutex_unlock(&resource->resource_lock);
 170
 171                 if (result)
 172                         return result;
 173
 174                 if (cur_state != ACPI_POWER_RESOURCE_STATE_ON)
 175                         break;
 176         }
 177
 178         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
 179                           cur_state ? "on" : "off"));
 180
 181         *state = cur_state;
 182
 183         return 0;
 184 }
 185
 186 static int __acpi_power_on(struct acpi_power_resource *resource)
 187 {
 188         acpi_status status = AE_OK;
 189
 190         status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL);
 191         if (ACPI_FAILURE(status))
 192                 return -ENODEV;
 193
 194         /* Update the power resource's _device_ power state */
 195         resource->device->power.state = ACPI_STATE_D0;
 196
 197         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned on\n",
 198                           resource->name));
 199
 200         return 0;
 201 }
 202
 203 static int acpi_power_on(acpi_handle handle)
 204 {
 205         int result = 0;
 206         struct acpi_power_resource *resource = NULL;
 207
 208         result = acpi_power_get_context(handle, &resource);
 209         if (result)
 210                 return result;
 211
 212         mutex_lock(&resource->resource_lock);
 213
 214         if (resource->ref_count++) {
 215                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 216                                   "Power resource [%s] already on",
 217                                   resource->name));
 218         } else {
 219                 result = __acpi_power_on(resource);
 220                 if (result)
 221                         resource->ref_count--;
 222         }
 223
 224         mutex_unlock(&resource->resource_lock);
 225
 226         return result;
 227 }
 228
 229 static int acpi_power_off(acpi_handle handle)
 230 {
 231         int result = 0;
 232         acpi_status status = AE_OK;
 233         struct acpi_power_resource *resource = NULL;
 234
 235         result = acpi_power_get_context(handle, &resource);
 236         if (result)
 237                 return result;
 238
 239         mutex_lock(&resource->resource_lock);
 240
 241         if (!resource->ref_count) {
 242                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 243                                   "Power resource [%s] already off",
 244                                   resource->name));
 245                 goto unlock;
 246         }
 247
 248         if (--resource->ref_count) {
 249                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 250                                   "Power resource [%s] still in use\n",
 251                                   resource->name));
 252                 goto unlock;
 253         }
 254
 255         status = acpi_evaluate_object(resource->device->handle, "_OFF", NULL, NULL);
 256         if (ACPI_FAILURE(status)) {
 257                 result = -ENODEV;
 258         } else {
 259                 /* Update the power resource's _device_ power state */
 260                 resource->device->power.state = ACPI_STATE_D3;
 261
 262                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 263                                   "Power resource [%s] turned off\n",
 264                                   resource->name));
 265         }
 266
 267  unlock:
 268         mutex_unlock(&resource->resource_lock);
 269
 270         return result;
 271 }
 272
 273 static void __acpi_power_off_list(struct acpi_handle_list *list, int num_res)
 274 {
 275         int i;
 276
 277         for (i = num_res - 1; i >= 0 ; i--)
 278                 acpi_power_off(list->handles[i]);
 279 }
 280
 281 static void acpi_power_off_list(struct acpi_handle_list *list)
 282 {
 283         __acpi_power_off_list(list, list->count);
 284 }
 285
 286 static int acpi_power_on_list(struct acpi_handle_list *list)
 287 {
 288         int result = 0;
 289         int i;
 290
 291         for (i = 0; i < list->count; i++) {
 292                 result = acpi_power_on(list->handles[i]);
 293                 if (result) {
 294                         __acpi_power_off_list(list, i);
 295                         break;
 296                 }
 297         }
 298
 299         return result;
 300 }
 301
 302 /**
 303  * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
 304  *                          ACPI 3.0) _PSW (Power State Wake)
 305  * @dev: Device to handle.
 306  * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
 307  * @sleep_state: Target sleep state of the system.
 308  * @dev_state: Target power state of the device.
 309  *
 310  * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 311  * State Wake) for the device, if present.  On failure reset the device's
 312  * wakeup.flags.valid flag.
 313  *
 314  * RETURN VALUE:
 315  * 0 if either _DSW or _PSW has been successfully executed
 316  * 0 if neither _DSW nor _PSW has been found
 317  * -ENODEV if the execution of either _DSW or _PSW has failed
 318  */
 319 int acpi_device_sleep_wake(struct acpi_device *dev,
 320                            int enable, int sleep_state, int dev_state)
 321 {
 322         union acpi_object in_arg[3];
 323         struct acpi_object_list arg_list = { 3, in_arg };
 324         acpi_status status = AE_OK;
 325
 326         /*
 327          * Try to execute _DSW first.
 328          *
 329          * Three agruments are needed for the _DSW object:
 330          * Argument 0: enable/disable the wake capabilities
 331          * Argument 1: target system state
 332          * Argument 2: target device state
 333          * When _DSW object is called to disable the wake capabilities, maybe
 334          * the first argument is filled. The values of the other two agruments
 335          * are meaningless.
 336          */
 337         in_arg[0].type = ACPI_TYPE_INTEGER;
 338         in_arg[0].integer.value = enable;
 339         in_arg[1].type = ACPI_TYPE_INTEGER;
 340         in_arg[1].integer.value = sleep_state;
 341         in_arg[2].type = ACPI_TYPE_INTEGER;
 342         in_arg[2].integer.value = dev_state;
 343         status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
 344         if (ACPI_SUCCESS(status)) {
 345                 return 0;
 346         } else if (status != AE_NOT_FOUND) {
 347                 printk(KERN_ERR PREFIX "_DSW execution failed\n");
 348                 dev->wakeup.flags.valid = 0;
 349                 return -ENODEV;
 350         }
 351
 352         /* Execute _PSW */
 353         arg_list.count = 1;
 354         in_arg[0].integer.value = enable;
 355         status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
 356         if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
 357                 printk(KERN_ERR PREFIX "_PSW execution failed\n");
 358                 dev->wakeup.flags.valid = 0;
 359                 return -ENODEV;
 360         }
 361
 362         return 0;
 363 }
 364
 365 /*
 366  * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
 367  * 1. Power on the power resources required for the wakeup device
 368  * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 369  *    State Wake) for the device, if present
 370  */
 371 int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
 372 {
 373         int i, err = 0;
 374
 375         if (!dev || !dev->wakeup.flags.valid)
 376                 return -EINVAL;
 377
 378         mutex_lock(&acpi_device_lock);
 379
 380         if (dev->wakeup.prepare_count++)
 381                 goto out;
 382
 383         /* Open power resource */
 384         for (i = 0; i < dev->wakeup.resources.count; i++) {
 385                 int ret = acpi_power_on(dev->wakeup.resources.handles[i]);
 386                 if (ret) {
 387                         printk(KERN_ERR PREFIX "Transition power state\n");
 388                         dev->wakeup.flags.valid = 0;
 389                         err = -ENODEV;
 390                         goto err_out;
 391                 }
 392         }
 393
 394         /*
 395          * Passing 3 as the third argument below means the device may be placed
 396          * in arbitrary power state afterwards.
 397          */
 398         err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
 399
 400  err_out:
 401         if (err)
 402                 dev->wakeup.prepare_count = 0;
 403
 404  out:
 405         mutex_unlock(&acpi_device_lock);
 406         return err;
 407 }
 408
 409 /*
 410  * Shutdown a wakeup device, counterpart of above method
 411  * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 412  *    State Wake) for the device, if present
 413  * 2. Shutdown down the power resources
 414  */
 415 int acpi_disable_wakeup_device_power(struct acpi_device *dev)
 416 {
 417         int i, err = 0;
 418
 419         if (!dev || !dev->wakeup.flags.valid)
 420                 return -EINVAL;
 421
 422         mutex_lock(&acpi_device_lock);
 423
 424         if (--dev->wakeup.prepare_count > 0)
 425                 goto out;
 426
 427         /*
 428          * Executing the code below even if prepare_count is already zero when
 429          * the function is called may be useful, for example for initialisation.
 430          */
 431         if (dev->wakeup.prepare_count < 0)
 432                 dev->wakeup.prepare_count = 0;
 433
 434         err = acpi_device_sleep_wake(dev, 0, 0, 0);
 435         if (err)
 436                 goto out;
 437
 438         /* Close power resource */
 439         for (i = 0; i < dev->wakeup.resources.count; i++) {
 440                 int ret = acpi_power_off(dev->wakeup.resources.handles[i]);
 441                 if (ret) {
 442                         printk(KERN_ERR PREFIX "Transition power state\n");
 443                         dev->wakeup.flags.valid = 0;
 444                         err = -ENODEV;
 445                         goto out;
 446                 }
 447         }
 448
 449  out:
 450         mutex_unlock(&acpi_device_lock);
 451         return err;
 452 }
 453
 454 /* --------------------------------------------------------------------------
 455                              Device Power Management
 456    -------------------------------------------------------------------------- */
 457
 458 int acpi_power_get_inferred_state(struct acpi_device *device, int *state)
 459 {
 460         int result = 0;
 461         struct acpi_handle_list *list = NULL;
 462         int list_state = 0;
 463         int i = 0;
 464
 465         if (!device || !state)
 466                 return -EINVAL;
 467
 468         /*
 469          * We know a device's inferred power state when all the resources
 470          * required for a given D-state are 'on'.
 471          */
 472         for (i = ACPI_STATE_D0; i < ACPI_STATE_D3; i++) {
 473                 list = &device->power.states[i].resources;
 474                 if (list->count < 1)
 475                         continue;
 476
 477                 result = acpi_power_get_list_state(list, &list_state);
 478                 if (result)
 479                         return result;
 480
 481                 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
 482                         *state = i;
 483                         return 0;
 484                 }
 485         }
 486
 487         *state = ACPI_STATE_D3;
 488         return 0;
 489 }
 490
 491 int acpi_power_on_resources(struct acpi_device *device, int state)
 492 {
 493         if (!device || state < ACPI_STATE_D0 || state > ACPI_STATE_D3)
 494                 return -EINVAL;
 495
 496         return acpi_power_on_list(&device->power.states[state].resources);
 497 }
 498
 499 int acpi_power_transition(struct acpi_device *device, int state)
 500 {
 501         int result;
 502
 503         if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
 504                 return -EINVAL;
 505
 506         if (device->power.state == state)
 507                 return 0;
 508
 509         if ((device->power.state < ACPI_STATE_D0)
 510             || (device->power.state > ACPI_STATE_D3))
 511                 return -ENODEV;
 512
 513         /* TBD: Resources must be ordered. */
 514
 515         /*
 516          * First we reference all power resources required in the target list
 517          * (e.g. so the device doesn't lose power while transitioning).  Then,
 518          * we dereference all power resources used in the current list.
 519          */
 520         result = acpi_power_on_list(&device->power.states[state].resources);
 521         if (!result)
 522                 acpi_power_off_list(
 523                         &device->power.states[device->power.state].resources);
 524
 525         /* We shouldn't change the state unless the above operations succeed. */
 526         device->power.state = result ? ACPI_STATE_UNKNOWN : state;
 527
 528         return result;
 529 }
 530
 531 /* --------------------------------------------------------------------------
 532                                 Driver Interface
 533    -------------------------------------------------------------------------- */
 534
 535 static int acpi_power_add(struct acpi_device *device)
 536 {
 537         int result = 0, state;
 538         acpi_status status = AE_OK;
 539         struct acpi_power_resource *resource = NULL;
 540         union acpi_object acpi_object;
 541         struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
 542
 543
 544         if (!device)
 545                 return -EINVAL;
 546
 547         resource = kzalloc(sizeof(struct acpi_power_resource), GFP_KERNEL);
 548         if (!resource)
 549                 return -ENOMEM;
 550
 551         resource->device = device;
 552         mutex_init(&resource->resource_lock);
 553         strcpy(resource->name, device->pnp.bus_id);
 554         strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
 555         strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
 556         device->driver_data = resource;
 557
 558         /* Evalute the object to get the system level and resource order. */
 559         status = acpi_evaluate_object(device->handle, NULL, NULL, &buffer);
 560         if (ACPI_FAILURE(status)) {
 561                 result = -ENODEV;
 562                 goto end;
 563         }
 564         resource->system_level = acpi_object.power_resource.system_level;
 565         resource->order = acpi_object.power_resource.resource_order;
 566
 567         result = acpi_power_get_state(device->handle, &state);
 568         if (result)
 569                 goto end;
 570
 571         switch (state) {
 572         case ACPI_POWER_RESOURCE_STATE_ON:
 573                 device->power.state = ACPI_STATE_D0;
 574                 break;
 575         case ACPI_POWER_RESOURCE_STATE_OFF:
 576                 device->power.state = ACPI_STATE_D3;
 577                 break;
 578         default:
 579                 device->power.state = ACPI_STATE_UNKNOWN;
 580                 break;
 581         }
 582
 583         printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
 584                acpi_device_bid(device), state ? "on" : "off");
 585
 586       end:
 587         if (result)
 588                 kfree(resource);
 589
 590         return result;
 591 }
 592
 593 static int acpi_power_remove(struct acpi_device *device, int type)
 594 {
 595         struct acpi_power_resource *resource;
 596
 597         if (!device)
 598                 return -EINVAL;
 599
 600         resource = acpi_driver_data(device);
 601         if (!resource)
 602                 return -EINVAL;
 603
 604         kfree(resource);
 605
 606         return 0;
 607 }
 608
 609 static int acpi_power_resume(struct acpi_device *device)
 610 {
 611         int result = 0, state;
 612         struct acpi_power_resource *resource;
 613
 614         if (!device)
 615                 return -EINVAL;
 616
 617         resource = acpi_driver_data(device);
 618         if (!resource)
 619                 return -EINVAL;
 620
 621         mutex_lock(&resource->resource_lock);
 622
 623         result = acpi_power_get_state(device->handle, &state);
 624         if (result)
 625                 goto unlock;
 626
 627         if (state == ACPI_POWER_RESOURCE_STATE_OFF && resource->ref_count)
 628                 result = __acpi_power_on(resource);
 629
 630  unlock:
 631         mutex_unlock(&resource->resource_lock);
 632
 633         return result;
 634 }
 635
 636 int __init acpi_power_init(void)
 637 {
 638         INIT_LIST_HEAD(&acpi_power_resource_list);
 639         return acpi_bus_register_driver(&acpi_power_driver);
 640 }