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 int acpi_power_nocheck;
  60 module_param_named(power_nocheck, acpi_power_nocheck, bool, 000);
  61
  62 static int acpi_power_add(struct acpi_device *device);
  63 static int acpi_power_remove(struct acpi_device *device, int type);
  64 static int acpi_power_resume(struct acpi_device *device);
  65
  66 static const struct acpi_device_id power_device_ids[] = {
  67         {ACPI_POWER_HID, 0},
  68         {"", 0},
  69 };
  70 MODULE_DEVICE_TABLE(acpi, power_device_ids);
  71
  72 static struct acpi_driver acpi_power_driver = {
  73         .name = "power",
  74         .class = ACPI_POWER_CLASS,
  75         .ids = power_device_ids,
  76         .ops = {
  77                 .add = acpi_power_add,
  78                 .remove = acpi_power_remove,
  79                 .resume = acpi_power_resume,
  80                 },
  81 };
  82
  83 struct acpi_power_reference {
  84         struct list_head node;
  85         struct acpi_device *device;
  86 };
  87
  88 struct acpi_power_resource {
  89         struct acpi_device * device;
  90         acpi_bus_id name;
  91         u32 system_level;
  92         u32 order;
  93         struct mutex resource_lock;
  94         struct list_head reference;
  95 };
  96
  97 static struct list_head acpi_power_resource_list;
  98
  99 /* --------------------------------------------------------------------------
 100                              Power Resource Management
 101    -------------------------------------------------------------------------- */
 102
 103 static int
 104 acpi_power_get_context(acpi_handle handle,
 105                        struct acpi_power_resource **resource)
 106 {
 107         int result = 0;
 108         struct acpi_device *device = NULL;
 109
 110
 111         if (!resource)
 112                 return -ENODEV;
 113
 114         result = acpi_bus_get_device(handle, &device);
 115         if (result) {
 116                 printk(KERN_WARNING PREFIX "Getting context [%p]\n", handle);
 117                 return result;
 118         }
 119
 120         *resource = acpi_driver_data(device);
 121         if (!*resource)
 122                 return -ENODEV;
 123
 124         return 0;
 125 }
 126
 127 static int acpi_power_get_state(acpi_handle handle, int *state)
 128 {
 129         acpi_status status = AE_OK;
 130         unsigned long long sta = 0;
 131         char node_name[5];
 132         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 133
 134
 135         if (!handle || !state)
 136                 return -EINVAL;
 137
 138         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 139         if (ACPI_FAILURE(status))
 140                 return -ENODEV;
 141
 142         *state = (sta & 0x01)?ACPI_POWER_RESOURCE_STATE_ON:
 143                               ACPI_POWER_RESOURCE_STATE_OFF;
 144
 145         acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 146
 147         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
 148                           node_name,
 149                                 *state ? "on" : "off"));
 150
 151         return 0;
 152 }
 153
 154 static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
 155 {
 156         int result = 0, state1;
 157         u32 i = 0;
 158
 159
 160         if (!list || !state)
 161                 return -EINVAL;
 162
 163         /* The state of the list is 'on' IFF all resources are 'on'. */
 164
 165         for (i = 0; i < list->count; i++) {
 166                 /*
 167                  * The state of the power resource can be obtained by
 168                  * using the ACPI handle. In such case it is unnecessary to
 169                  * get the Power resource first and then get its state again.
 170                  */
 171                 result = acpi_power_get_state(list->handles[i], &state1);
 172                 if (result)
 173                         return result;
 174
 175                 *state = state1;
 176
 177                 if (*state != ACPI_POWER_RESOURCE_STATE_ON)
 178                         break;
 179         }
 180
 181         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
 182                           *state ? "on" : "off"));
 183
 184         return result;
 185 }
 186
 187 static int acpi_power_on(acpi_handle handle, struct acpi_device *dev)
 188 {
 189         int result = 0;
 190         int found = 0;
 191         acpi_status status = AE_OK;
 192         struct acpi_power_resource *resource = NULL;
 193         struct list_head *node, *next;
 194         struct acpi_power_reference *ref;
 195
 196
 197         result = acpi_power_get_context(handle, &resource);
 198         if (result)
 199                 return result;
 200
 201         mutex_lock(&resource->resource_lock);
 202         list_for_each_safe(node, next, &resource->reference) {
 203                 ref = container_of(node, struct acpi_power_reference, node);
 204                 if (dev->handle == ref->device->handle) {
 205                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] already referenced by resource [%s]\n",
 206                                   dev->pnp.bus_id, resource->name));
 207                         found = 1;
 208                         break;
 209                 }
 210         }
 211
 212         if (!found) {
 213                 ref = kmalloc(sizeof (struct acpi_power_reference),
 214                     irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL);
 215                 if (!ref) {
 216                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "kmalloc() failed\n"));
 217                         mutex_unlock(&resource->resource_lock);
 218                         return -ENOMEM;
 219                 }
 220                 list_add_tail(&ref->node, &resource->reference);
 221                 ref->device = dev;
 222                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] added to resource [%s] references\n",
 223                           dev->pnp.bus_id, resource->name));
 224         }
 225         mutex_unlock(&resource->resource_lock);
 226
 227         status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL);
 228         if (ACPI_FAILURE(status))
 229                 return -ENODEV;
 230
 231         /* Update the power resource's _device_ power state */
 232         resource->device->power.state = ACPI_STATE_D0;
 233
 234         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned on\n",
 235                           resource->name));
 236         return 0;
 237 }
 238
 239 static int acpi_power_off_device(acpi_handle handle, struct acpi_device *dev)
 240 {
 241         int result = 0;
 242         acpi_status status = AE_OK;
 243         struct acpi_power_resource *resource = NULL;
 244         struct list_head *node, *next;
 245
 246         result = acpi_power_get_context(handle, &resource);
 247         if (result)
 248                 return result;
 249
 250         mutex_lock(&resource->resource_lock);
 251         list_for_each_safe(node, next, &resource->reference) {
 252                 ref = container_of(node, struct acpi_power_reference, node);
 253                 if (dev->handle == ref->device->handle) {
 254                         list_del(&ref->node);
 255                         kfree(ref);
 256                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] removed from resource [%s] references\n",
 257                             dev->pnp.bus_id, resource->name));
 258                         break;
 259                 }
 260         }
 261
 262         if (!list_empty(&resource->reference)) {
 263                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Cannot turn resource [%s] off - resource is in use\n",
 264                     resource->name));
 265                 mutex_unlock(&resource->resource_lock);
 266                 return 0;
 267         }
 268         mutex_unlock(&resource->resource_lock);
 269
 270         status = acpi_evaluate_object(resource->device->handle, "_OFF", NULL, NULL);
 271         if (ACPI_FAILURE(status))
 272                 return -ENODEV;
 273
 274         /* Update the power resource's _device_ power state */
 275         resource->device->power.state = ACPI_STATE_D3;
 276
 277         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned off\n",
 278                           resource->name));
 279
 280         return 0;
 281 }
 282
 283 /**
 284  * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
 285  *                          ACPI 3.0) _PSW (Power State Wake)
 286  * @dev: Device to handle.
 287  * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
 288  * @sleep_state: Target sleep state of the system.
 289  * @dev_state: Target power state of the device.
 290  *
 291  * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 292  * State Wake) for the device, if present.  On failure reset the device's
 293  * wakeup.flags.valid flag.
 294  *
 295  * RETURN VALUE:
 296  * 0 if either _DSW or _PSW has been successfully executed
 297  * 0 if neither _DSW nor _PSW has been found
 298  * -ENODEV if the execution of either _DSW or _PSW has failed
 299  */
 300 int acpi_device_sleep_wake(struct acpi_device *dev,
 301                            int enable, int sleep_state, int dev_state)
 302 {
 303         union acpi_object in_arg[3];
 304         struct acpi_object_list arg_list = { 3, in_arg };
 305         acpi_status status = AE_OK;
 306
 307         /*
 308          * Try to execute _DSW first.
 309          *
 310          * Three agruments are needed for the _DSW object:
 311          * Argument 0: enable/disable the wake capabilities
 312          * Argument 1: target system state
 313          * Argument 2: target device state
 314          * When _DSW object is called to disable the wake capabilities, maybe
 315          * the first argument is filled. The values of the other two agruments
 316          * are meaningless.
 317          */
 318         in_arg[0].type = ACPI_TYPE_INTEGER;
 319         in_arg[0].integer.value = enable;
 320         in_arg[1].type = ACPI_TYPE_INTEGER;
 321         in_arg[1].integer.value = sleep_state;
 322         in_arg[2].type = ACPI_TYPE_INTEGER;
 323         in_arg[2].integer.value = dev_state;
 324         status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
 325         if (ACPI_SUCCESS(status)) {
 326                 return 0;
 327         } else if (status != AE_NOT_FOUND) {
 328                 printk(KERN_ERR PREFIX "_DSW execution failed\n");
 329                 dev->wakeup.flags.valid = 0;
 330                 return -ENODEV;
 331         }
 332
 333         /* Execute _PSW */
 334         arg_list.count = 1;
 335         in_arg[0].integer.value = enable;
 336         status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
 337         if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
 338                 printk(KERN_ERR PREFIX "_PSW execution failed\n");
 339                 dev->wakeup.flags.valid = 0;
 340                 return -ENODEV;
 341         }
 342
 343         return 0;
 344 }
 345
 346 /*
 347  * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
 348  * 1. Power on the power resources required for the wakeup device
 349  * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 350  *    State Wake) for the device, if present
 351  */
 352 int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
 353 {
 354         int i, err = 0;
 355
 356         if (!dev || !dev->wakeup.flags.valid)
 357                 return -EINVAL;
 358
 359         mutex_lock(&acpi_device_lock);
 360
 361         if (dev->wakeup.prepare_count++)
 362                 goto out;
 363
 364         /* Open power resource */
 365         for (i = 0; i < dev->wakeup.resources.count; i++) {
 366                 int ret = acpi_power_on(dev->wakeup.resources.handles[i], dev);
 367                 if (ret) {
 368                         printk(KERN_ERR PREFIX "Transition power state\n");
 369                         dev->wakeup.flags.valid = 0;
 370                         err = -ENODEV;
 371                         goto err_out;
 372                 }
 373         }
 374
 375         /*
 376          * Passing 3 as the third argument below means the device may be placed
 377          * in arbitrary power state afterwards.
 378          */
 379         err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
 380
 381  err_out:
 382         if (err)
 383                 dev->wakeup.prepare_count = 0;
 384
 385  out:
 386         mutex_unlock(&acpi_device_lock);
 387         return err;
 388 }
 389
 390 /*
 391  * Shutdown a wakeup device, counterpart of above method
 392  * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 393  *    State Wake) for the device, if present
 394  * 2. Shutdown down the power resources
 395  */
 396 int acpi_disable_wakeup_device_power(struct acpi_device *dev)
 397 {
 398         int i, err = 0;
 399
 400         if (!dev || !dev->wakeup.flags.valid)
 401                 return -EINVAL;
 402
 403         mutex_lock(&acpi_device_lock);
 404
 405         if (--dev->wakeup.prepare_count > 0)
 406                 goto out;
 407
 408         /*
 409          * Executing the code below even if prepare_count is already zero when
 410          * the function is called may be useful, for example for initialisation.
 411          */
 412         if (dev->wakeup.prepare_count < 0)
 413                 dev->wakeup.prepare_count = 0;
 414
 415         err = acpi_device_sleep_wake(dev, 0, 0, 0);
 416         if (err)
 417                 goto out;
 418
 419         /* Close power resource */
 420         for (i = 0; i < dev->wakeup.resources.count; i++) {
 421                 int ret = acpi_power_off_device(
 422                                 dev->wakeup.resources.handles[i], dev);
 423                 if (ret) {
 424                         printk(KERN_ERR PREFIX "Transition power state\n");
 425                         dev->wakeup.flags.valid = 0;
 426                         err = -ENODEV;
 427                         goto out;
 428                 }
 429         }
 430
 431  out:
 432         mutex_unlock(&acpi_device_lock);
 433         return err;
 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                                 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         INIT_LIST_HEAD(&resource->reference);
 554         strcpy(resource->name, device->pnp.bus_id);
 555         strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
 556         strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
 557         device->driver_data = resource;
 558
 559         /* Evalute the object to get the system level and resource order. */
 560         status = acpi_evaluate_object(device->handle, NULL, NULL, &buffer);
 561         if (ACPI_FAILURE(status)) {
 562                 result = -ENODEV;
 563                 goto end;
 564         }
 565         resource->system_level = acpi_object.power_resource.system_level;
 566         resource->order = acpi_object.power_resource.resource_order;
 567
 568         result = acpi_power_get_state(device->handle, &state);
 569         if (result)
 570                 goto end;
 571
 572         switch (state) {
 573         case ACPI_POWER_RESOURCE_STATE_ON:
 574                 device->power.state = ACPI_STATE_D0;
 575                 break;
 576         case ACPI_POWER_RESOURCE_STATE_OFF:
 577                 device->power.state = ACPI_STATE_D3;
 578                 break;
 579         default:
 580                 device->power.state = ACPI_STATE_UNKNOWN;
 581                 break;
 582         }
 583
 584         printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
 585                acpi_device_bid(device), state ? "on" : "off");
 586
 587       end:
 588         if (result)
 589                 kfree(resource);
 590
 591         return result;
 592 }
 593
 594 static int acpi_power_remove(struct acpi_device *device, int type)
 595 {
 596         struct acpi_power_resource *resource = NULL;
 597         struct list_head *node, *next;
 598
 599
 600         if (!device || !acpi_driver_data(device))
 601                 return -EINVAL;
 602
 603         resource = acpi_driver_data(device);
 604
 605         mutex_lock(&resource->resource_lock);
 606         list_for_each_safe(node, next, &resource->reference) {
 607                 struct acpi_power_reference *ref = container_of(node, struct acpi_power_reference, node);
 608                 list_del(&ref->node);
 609                 kfree(ref);
 610         }
 611         mutex_unlock(&resource->resource_lock);
 612
 613         kfree(resource);
 614
 615         return 0;
 616 }
 617
 618 static int acpi_power_resume(struct acpi_device *device)
 619 {
 620         int result = 0, state;
 621         struct acpi_power_resource *resource = NULL;
 622         struct acpi_power_reference *ref;
 623
 624         if (!device || !acpi_driver_data(device))
 625                 return -EINVAL;
 626
 627         resource = acpi_driver_data(device);
 628
 629         result = acpi_power_get_state(device->handle, &state);
 630         if (result)
 631                 return result;
 632
 633         mutex_lock(&resource->resource_lock);
 634         if (state == ACPI_POWER_RESOURCE_STATE_OFF &&
 635             !list_empty(&resource->reference)) {
 636                 ref = container_of(resource->reference.next, struct acpi_power_reference, node);
 637                 mutex_unlock(&resource->resource_lock);
 638                 result = acpi_power_on(device->handle, ref->device);
 639                 return result;
 640         }
 641
 642         mutex_unlock(&resource->resource_lock);
 643         return 0;
 644 }
 645
 646 int __init acpi_power_init(void)
 647 {
 648         INIT_LIST_HEAD(&acpi_power_resource_list);
 649         return acpi_bus_register_driver(&acpi_power_driver);
 650 }