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_resource {
  84         struct acpi_device * device;
  85         acpi_bus_id name;
  86         u32 system_level;
  87         u32 order;
  88         unsigned int ref_count;
  89         struct mutex resource_lock;
  90 };
  91
  92 static struct list_head acpi_power_resource_list;
  93
  94 /* --------------------------------------------------------------------------
  95                              Power Resource Management
  96    -------------------------------------------------------------------------- */
  97
  98 static int
  99 acpi_power_get_context(acpi_handle handle,
 100                        struct acpi_power_resource **resource)
 101 {
 102         int result = 0;
 103         struct acpi_device *device = NULL;
 104
 105
 106         if (!resource)
 107                 return -ENODEV;
 108
 109         result = acpi_bus_get_device(handle, &device);
 110         if (result) {
 111                 printk(KERN_WARNING PREFIX "Getting context [%p]\n", handle);
 112                 return result;
 113         }
 114
 115         *resource = acpi_driver_data(device);
 116         if (!*resource)
 117                 return -ENODEV;
 118
 119         return 0;
 120 }
 121
 122 static int acpi_power_get_state(acpi_handle handle, int *state)
 123 {
 124         acpi_status status = AE_OK;
 125         unsigned long long sta = 0;
 126         char node_name[5];
 127         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 128
 129
 130         if (!handle || !state)
 131                 return -EINVAL;
 132
 133         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 134         if (ACPI_FAILURE(status))
 135                 return -ENODEV;
 136
 137         *state = (sta & 0x01)?ACPI_POWER_RESOURCE_STATE_ON:
 138                               ACPI_POWER_RESOURCE_STATE_OFF;
 139
 140         acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 141
 142         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
 143                           node_name,
 144                                 *state ? "on" : "off"));
 145
 146         return 0;
 147 }
 148
 149 static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
 150 {
 151         int result = 0, state1;
 152         u32 i = 0;
 153
 154
 155         if (!list || !state)
 156                 return -EINVAL;
 157
 158         /* The state of the list is 'on' IFF all resources are 'on'. */
 159
 160         for (i = 0; i < list->count; i++) {
 161                 /*
 162                  * The state of the power resource can be obtained by
 163                  * using the ACPI handle. In such case it is unnecessary to
 164                  * get the Power resource first and then get its state again.
 165                  */
 166                 result = acpi_power_get_state(list->handles[i], &state1);
 167                 if (result)
 168                         return result;
 169
 170                 *state = state1;
 171
 172                 if (*state != ACPI_POWER_RESOURCE_STATE_ON)
 173                         break;
 174         }
 175
 176         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
 177                           *state ? "on" : "off"));
 178
 179         return result;
 180 }
 181
 182 static int __acpi_power_on(struct acpi_power_resource *resource)
 183 {
 184         acpi_status status = AE_OK;
 185
 186         status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL);
 187         if (ACPI_FAILURE(status))
 188                 return -ENODEV;
 189
 190         /* Update the power resource's _device_ power state */
 191         resource->device->power.state = ACPI_STATE_D0;
 192
 193         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned on\n",
 194                           resource->name));
 195
 196         return 0;
 197 }
 198
 199 static int acpi_power_on(acpi_handle handle)
 200 {
 201         int result = 0;
 202         struct acpi_power_resource *resource = NULL;
 203
 204         result = acpi_power_get_context(handle, &resource);
 205         if (result)
 206                 return result;
 207
 208         mutex_lock(&resource->resource_lock);
 209
 210         if (resource->ref_count++) {
 211                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 212                                   "Power resource [%s] already on",
 213                                   resource->name));
 214         } else {
 215                 result = __acpi_power_on(resource);
 216         }
 217
 218         mutex_unlock(&resource->resource_lock);
 219
 220         return 0;
 221 }
 222
 223 static int acpi_power_off_device(acpi_handle handle)
 224 {
 225         int result = 0;
 226         acpi_status status = AE_OK;
 227         struct acpi_power_resource *resource = NULL;
 228
 229         result = acpi_power_get_context(handle, &resource);
 230         if (result)
 231                 return result;
 232
 233         mutex_lock(&resource->resource_lock);
 234
 235         if (!resource->ref_count) {
 236                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 237                                   "Power resource [%s] already off",
 238                                   resource->name));
 239                 goto unlock;
 240         }
 241
 242         if (--resource->ref_count) {
 243                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 244                                   "Power resource [%s] still in use\n",
 245                                   resource->name));
 246                 goto unlock;
 247         }
 248
 249         status = acpi_evaluate_object(resource->device->handle, "_OFF", NULL, NULL);
 250         if (ACPI_FAILURE(status)) {
 251                 result = -ENODEV;
 252         } else {
 253                 /* Update the power resource's _device_ power state */
 254                 resource->device->power.state = ACPI_STATE_D3;
 255
 256                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 257                                   "Power resource [%s] turned off\n",
 258                                   resource->name));
 259         }
 260
 261  unlock:
 262         mutex_unlock(&resource->resource_lock);
 263
 264         return result;
 265 }
 266
 267 /**
 268  * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
 269  *                          ACPI 3.0) _PSW (Power State Wake)
 270  * @dev: Device to handle.
 271  * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
 272  * @sleep_state: Target sleep state of the system.
 273  * @dev_state: Target power state of the device.
 274  *
 275  * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 276  * State Wake) for the device, if present.  On failure reset the device's
 277  * wakeup.flags.valid flag.
 278  *
 279  * RETURN VALUE:
 280  * 0 if either _DSW or _PSW has been successfully executed
 281  * 0 if neither _DSW nor _PSW has been found
 282  * -ENODEV if the execution of either _DSW or _PSW has failed
 283  */
 284 int acpi_device_sleep_wake(struct acpi_device *dev,
 285                            int enable, int sleep_state, int dev_state)
 286 {
 287         union acpi_object in_arg[3];
 288         struct acpi_object_list arg_list = { 3, in_arg };
 289         acpi_status status = AE_OK;
 290
 291         /*
 292          * Try to execute _DSW first.
 293          *
 294          * Three agruments are needed for the _DSW object:
 295          * Argument 0: enable/disable the wake capabilities
 296          * Argument 1: target system state
 297          * Argument 2: target device state
 298          * When _DSW object is called to disable the wake capabilities, maybe
 299          * the first argument is filled. The values of the other two agruments
 300          * are meaningless.
 301          */
 302         in_arg[0].type = ACPI_TYPE_INTEGER;
 303         in_arg[0].integer.value = enable;
 304         in_arg[1].type = ACPI_TYPE_INTEGER;
 305         in_arg[1].integer.value = sleep_state;
 306         in_arg[2].type = ACPI_TYPE_INTEGER;
 307         in_arg[2].integer.value = dev_state;
 308         status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
 309         if (ACPI_SUCCESS(status)) {
 310                 return 0;
 311         } else if (status != AE_NOT_FOUND) {
 312                 printk(KERN_ERR PREFIX "_DSW execution failed\n");
 313                 dev->wakeup.flags.valid = 0;
 314                 return -ENODEV;
 315         }
 316
 317         /* Execute _PSW */
 318         arg_list.count = 1;
 319         in_arg[0].integer.value = enable;
 320         status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
 321         if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
 322                 printk(KERN_ERR PREFIX "_PSW execution failed\n");
 323                 dev->wakeup.flags.valid = 0;
 324                 return -ENODEV;
 325         }
 326
 327         return 0;
 328 }
 329
 330 /*
 331  * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
 332  * 1. Power on the power resources required for the wakeup device
 333  * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 334  *    State Wake) for the device, if present
 335  */
 336 int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
 337 {
 338         int i, err = 0;
 339
 340         if (!dev || !dev->wakeup.flags.valid)
 341                 return -EINVAL;
 342
 343         mutex_lock(&acpi_device_lock);
 344
 345         if (dev->wakeup.prepare_count++)
 346                 goto out;
 347
 348         /* Open power resource */
 349         for (i = 0; i < dev->wakeup.resources.count; i++) {
 350                 int ret = acpi_power_on(dev->wakeup.resources.handles[i]);
 351                 if (ret) {
 352                         printk(KERN_ERR PREFIX "Transition power state\n");
 353                         dev->wakeup.flags.valid = 0;
 354                         err = -ENODEV;
 355                         goto err_out;
 356                 }
 357         }
 358
 359         /*
 360          * Passing 3 as the third argument below means the device may be placed
 361          * in arbitrary power state afterwards.
 362          */
 363         err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
 364
 365  err_out:
 366         if (err)
 367                 dev->wakeup.prepare_count = 0;
 368
 369  out:
 370         mutex_unlock(&acpi_device_lock);
 371         return err;
 372 }
 373
 374 /*
 375  * Shutdown a wakeup device, counterpart of above method
 376  * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 377  *    State Wake) for the device, if present
 378  * 2. Shutdown down the power resources
 379  */
 380 int acpi_disable_wakeup_device_power(struct acpi_device *dev)
 381 {
 382         int i, err = 0;
 383
 384         if (!dev || !dev->wakeup.flags.valid)
 385                 return -EINVAL;
 386
 387         mutex_lock(&acpi_device_lock);
 388
 389         if (--dev->wakeup.prepare_count > 0)
 390                 goto out;
 391
 392         /*
 393          * Executing the code below even if prepare_count is already zero when
 394          * the function is called may be useful, for example for initialisation.
 395          */
 396         if (dev->wakeup.prepare_count < 0)
 397                 dev->wakeup.prepare_count = 0;
 398
 399         err = acpi_device_sleep_wake(dev, 0, 0, 0);
 400         if (err)
 401                 goto out;
 402
 403         /* Close power resource */
 404         for (i = 0; i < dev->wakeup.resources.count; i++) {
 405                 int ret = acpi_power_off_device(
 406                                 dev->wakeup.resources.handles[i]);
 407                 if (ret) {
 408                         printk(KERN_ERR PREFIX "Transition power state\n");
 409                         dev->wakeup.flags.valid = 0;
 410                         err = -ENODEV;
 411                         goto out;
 412                 }
 413         }
 414
 415  out:
 416         mutex_unlock(&acpi_device_lock);
 417         return err;
 418 }
 419
 420 /* --------------------------------------------------------------------------
 421                              Device Power Management
 422    -------------------------------------------------------------------------- */
 423
 424 int acpi_power_get_inferred_state(struct acpi_device *device)
 425 {
 426         int result = 0;
 427         struct acpi_handle_list *list = NULL;
 428         int list_state = 0;
 429         int i = 0;
 430
 431
 432         if (!device)
 433                 return -EINVAL;
 434
 435         device->power.state = ACPI_STATE_UNKNOWN;
 436
 437         /*
 438          * We know a device's inferred power state when all the resources
 439          * required for a given D-state are 'on'.
 440          */
 441         for (i = ACPI_STATE_D0; i < ACPI_STATE_D3; i++) {
 442                 list = &device->power.states[i].resources;
 443                 if (list->count < 1)
 444                         continue;
 445
 446                 result = acpi_power_get_list_state(list, &list_state);
 447                 if (result)
 448                         return result;
 449
 450                 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
 451                         device->power.state = i;
 452                         return 0;
 453                 }
 454         }
 455
 456         device->power.state = ACPI_STATE_D3;
 457
 458         return 0;
 459 }
 460
 461 int acpi_power_transition(struct acpi_device *device, int state)
 462 {
 463         int result = 0;
 464         struct acpi_handle_list *cl = NULL;     /* Current Resources */
 465         struct acpi_handle_list *tl = NULL;     /* Target Resources */
 466         int i = 0;
 467
 468
 469         if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
 470                 return -EINVAL;
 471
 472         if ((device->power.state < ACPI_STATE_D0)
 473             || (device->power.state > ACPI_STATE_D3))
 474                 return -ENODEV;
 475
 476         cl = &device->power.states[device->power.state].resources;
 477         tl = &device->power.states[state].resources;
 478
 479         /* TBD: Resources must be ordered. */
 480
 481         /*
 482          * First we reference all power resources required in the target list
 483          * (e.g. so the device doesn't lose power while transitioning).
 484          */
 485         for (i = 0; i < tl->count; i++) {
 486                 result = acpi_power_on(tl->handles[i]);
 487                 if (result)
 488                         goto end;
 489         }
 490
 491         if (device->power.state == state) {
 492                 goto end;
 493         }
 494
 495         /*
 496          * Then we dereference all power resources used in the current list.
 497          */
 498         for (i = 0; i < cl->count; i++) {
 499                 result = acpi_power_off_device(cl->handles[i]);
 500                 if (result)
 501                         goto end;
 502         }
 503
 504      end:
 505         if (result)
 506                 device->power.state = ACPI_STATE_UNKNOWN;
 507         else {
 508         /* We shouldn't change the state till all above operations succeed */
 509                 device->power.state = state;
 510         }
 511
 512         return result;
 513 }
 514
 515 /* --------------------------------------------------------------------------
 516                                 Driver Interface
 517    -------------------------------------------------------------------------- */
 518
 519 static int acpi_power_add(struct acpi_device *device)
 520 {
 521         int result = 0, state;
 522         acpi_status status = AE_OK;
 523         struct acpi_power_resource *resource = NULL;
 524         union acpi_object acpi_object;
 525         struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
 526
 527
 528         if (!device)
 529                 return -EINVAL;
 530
 531         resource = kzalloc(sizeof(struct acpi_power_resource), GFP_KERNEL);
 532         if (!resource)
 533                 return -ENOMEM;
 534
 535         resource->device = device;
 536         mutex_init(&resource->resource_lock);
 537         strcpy(resource->name, device->pnp.bus_id);
 538         strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
 539         strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
 540         device->driver_data = resource;
 541
 542         /* Evalute the object to get the system level and resource order. */
 543         status = acpi_evaluate_object(device->handle, NULL, NULL, &buffer);
 544         if (ACPI_FAILURE(status)) {
 545                 result = -ENODEV;
 546                 goto end;
 547         }
 548         resource->system_level = acpi_object.power_resource.system_level;
 549         resource->order = acpi_object.power_resource.resource_order;
 550
 551         result = acpi_power_get_state(device->handle, &state);
 552         if (result)
 553                 goto end;
 554
 555         switch (state) {
 556         case ACPI_POWER_RESOURCE_STATE_ON:
 557                 device->power.state = ACPI_STATE_D0;
 558                 break;
 559         case ACPI_POWER_RESOURCE_STATE_OFF:
 560                 device->power.state = ACPI_STATE_D3;
 561                 break;
 562         default:
 563                 device->power.state = ACPI_STATE_UNKNOWN;
 564                 break;
 565         }
 566
 567         printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
 568                acpi_device_bid(device), state ? "on" : "off");
 569
 570       end:
 571         if (result)
 572                 kfree(resource);
 573
 574         return result;
 575 }
 576
 577 static int acpi_power_remove(struct acpi_device *device, int type)
 578 {
 579         struct acpi_power_resource *resource;
 580
 581         if (!device)
 582                 return -EINVAL;
 583
 584         resource = acpi_driver_data(device);
 585         if (!resource)
 586                 return -EINVAL;
 587
 588         kfree(resource);
 589
 590         return 0;
 591 }
 592
 593 static int acpi_power_resume(struct acpi_device *device)
 594 {
 595         int result = 0, state;
 596         struct acpi_power_resource *resource;
 597
 598         if (!device)
 599                 return -EINVAL;
 600
 601         resource = acpi_driver_data(device);
 602         if (!resource)
 603                 return -EINVAL;
 604
 605         mutex_lock(&resource->resource_lock);
 606
 607         result = acpi_power_get_state(device->handle, &state);
 608         if (result)
 609                 goto unlock;
 610
 611         if (state == ACPI_POWER_RESOURCE_STATE_OFF && resource->ref_count)
 612                 result = __acpi_power_on(resource);
 613
 614  unlock:
 615         mutex_unlock(&resource->resource_lock);
 616
 617         return result;
 618 }
 619
 620 int __init acpi_power_init(void)
 621 {
 622         INIT_LIST_HEAD(&acpi_power_resource_list);
 623         return acpi_bus_register_driver(&acpi_power_driver);
 624 }