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                 if (result)
 217                         resource->ref_count--;
 218         }
 219
 220         mutex_unlock(&resource->resource_lock);
 221
 222         return result;
 223 }
 224
 225 static int acpi_power_off_device(acpi_handle handle)
 226 {
 227         int result = 0;
 228         acpi_status status = AE_OK;
 229         struct acpi_power_resource *resource = NULL;
 230
 231         result = acpi_power_get_context(handle, &resource);
 232         if (result)
 233                 return result;
 234
 235         mutex_lock(&resource->resource_lock);
 236
 237         if (!resource->ref_count) {
 238                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 239                                   "Power resource [%s] already off",
 240                                   resource->name));
 241                 goto unlock;
 242         }
 243
 244         if (--resource->ref_count) {
 245                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 246                                   "Power resource [%s] still in use\n",
 247                                   resource->name));
 248                 goto unlock;
 249         }
 250
 251         status = acpi_evaluate_object(resource->device->handle, "_OFF", NULL, NULL);
 252         if (ACPI_FAILURE(status)) {
 253                 result = -ENODEV;
 254         } else {
 255                 /* Update the power resource's _device_ power state */
 256                 resource->device->power.state = ACPI_STATE_D3;
 257
 258                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 259                                   "Power resource [%s] turned off\n",
 260                                   resource->name));
 261         }
 262
 263  unlock:
 264         mutex_unlock(&resource->resource_lock);
 265
 266         return result;
 267 }
 268
 269 static void __acpi_power_off_list(struct acpi_handle_list *list, int num_res)
 270 {
 271         int i;
 272
 273         for (i = num_res - 1; i >= 0 ; i--)
 274                 acpi_power_off_device(list->handles[i]);
 275 }
 276
 277 static void acpi_power_off_list(struct acpi_handle_list *list)
 278 {
 279         __acpi_power_off_list(list, list->count);
 280 }
 281
 282 static int acpi_power_on_list(struct acpi_handle_list *list)
 283 {
 284         int result = 0;
 285         int i;
 286
 287         for (i = 0; i < list->count; i++) {
 288                 result = acpi_power_on(list->handles[i]);
 289                 if (result) {
 290                         __acpi_power_off_list(list, i);
 291                         break;
 292                 }
 293         }
 294
 295         return result;
 296 }
 297
 298 /**
 299  * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
 300  *                          ACPI 3.0) _PSW (Power State Wake)
 301  * @dev: Device to handle.
 302  * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
 303  * @sleep_state: Target sleep state of the system.
 304  * @dev_state: Target power state of the device.
 305  *
 306  * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 307  * State Wake) for the device, if present.  On failure reset the device's
 308  * wakeup.flags.valid flag.
 309  *
 310  * RETURN VALUE:
 311  * 0 if either _DSW or _PSW has been successfully executed
 312  * 0 if neither _DSW nor _PSW has been found
 313  * -ENODEV if the execution of either _DSW or _PSW has failed
 314  */
 315 int acpi_device_sleep_wake(struct acpi_device *dev,
 316                            int enable, int sleep_state, int dev_state)
 317 {
 318         union acpi_object in_arg[3];
 319         struct acpi_object_list arg_list = { 3, in_arg };
 320         acpi_status status = AE_OK;
 321
 322         /*
 323          * Try to execute _DSW first.
 324          *
 325          * Three agruments are needed for the _DSW object:
 326          * Argument 0: enable/disable the wake capabilities
 327          * Argument 1: target system state
 328          * Argument 2: target device state
 329          * When _DSW object is called to disable the wake capabilities, maybe
 330          * the first argument is filled. The values of the other two agruments
 331          * are meaningless.
 332          */
 333         in_arg[0].type = ACPI_TYPE_INTEGER;
 334         in_arg[0].integer.value = enable;
 335         in_arg[1].type = ACPI_TYPE_INTEGER;
 336         in_arg[1].integer.value = sleep_state;
 337         in_arg[2].type = ACPI_TYPE_INTEGER;
 338         in_arg[2].integer.value = dev_state;
 339         status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
 340         if (ACPI_SUCCESS(status)) {
 341                 return 0;
 342         } else if (status != AE_NOT_FOUND) {
 343                 printk(KERN_ERR PREFIX "_DSW execution failed\n");
 344                 dev->wakeup.flags.valid = 0;
 345                 return -ENODEV;
 346         }
 347
 348         /* Execute _PSW */
 349         arg_list.count = 1;
 350         in_arg[0].integer.value = enable;
 351         status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
 352         if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
 353                 printk(KERN_ERR PREFIX "_PSW execution failed\n");
 354                 dev->wakeup.flags.valid = 0;
 355                 return -ENODEV;
 356         }
 357
 358         return 0;
 359 }
 360
 361 /*
 362  * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
 363  * 1. Power on the power resources required for the wakeup device
 364  * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 365  *    State Wake) for the device, if present
 366  */
 367 int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
 368 {
 369         int i, err = 0;
 370
 371         if (!dev || !dev->wakeup.flags.valid)
 372                 return -EINVAL;
 373
 374         mutex_lock(&acpi_device_lock);
 375
 376         if (dev->wakeup.prepare_count++)
 377                 goto out;
 378
 379         /* Open power resource */
 380         for (i = 0; i < dev->wakeup.resources.count; i++) {
 381                 int ret = acpi_power_on(dev->wakeup.resources.handles[i]);
 382                 if (ret) {
 383                         printk(KERN_ERR PREFIX "Transition power state\n");
 384                         dev->wakeup.flags.valid = 0;
 385                         err = -ENODEV;
 386                         goto err_out;
 387                 }
 388         }
 389
 390         /*
 391          * Passing 3 as the third argument below means the device may be placed
 392          * in arbitrary power state afterwards.
 393          */
 394         err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
 395
 396  err_out:
 397         if (err)
 398                 dev->wakeup.prepare_count = 0;
 399
 400  out:
 401         mutex_unlock(&acpi_device_lock);
 402         return err;
 403 }
 404
 405 /*
 406  * Shutdown a wakeup device, counterpart of above method
 407  * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 408  *    State Wake) for the device, if present
 409  * 2. Shutdown down the power resources
 410  */
 411 int acpi_disable_wakeup_device_power(struct acpi_device *dev)
 412 {
 413         int i, err = 0;
 414
 415         if (!dev || !dev->wakeup.flags.valid)
 416                 return -EINVAL;
 417
 418         mutex_lock(&acpi_device_lock);
 419
 420         if (--dev->wakeup.prepare_count > 0)
 421                 goto out;
 422
 423         /*
 424          * Executing the code below even if prepare_count is already zero when
 425          * the function is called may be useful, for example for initialisation.
 426          */
 427         if (dev->wakeup.prepare_count < 0)
 428                 dev->wakeup.prepare_count = 0;
 429
 430         err = acpi_device_sleep_wake(dev, 0, 0, 0);
 431         if (err)
 432                 goto out;
 433
 434         /* Close power resource */
 435         for (i = 0; i < dev->wakeup.resources.count; i++) {
 436                 int ret = acpi_power_off_device(
 437                                 dev->wakeup.resources.handles[i]);
 438                 if (ret) {
 439                         printk(KERN_ERR PREFIX "Transition power state\n");
 440                         dev->wakeup.flags.valid = 0;
 441                         err = -ENODEV;
 442                         goto out;
 443                 }
 444         }
 445
 446  out:
 447         mutex_unlock(&acpi_device_lock);
 448         return err;
 449 }
 450
 451 /* --------------------------------------------------------------------------
 452                              Device Power Management
 453    -------------------------------------------------------------------------- */
 454
 455 int acpi_power_get_inferred_state(struct acpi_device *device, int *state)
 456 {
 457         int result = 0;
 458         struct acpi_handle_list *list = NULL;
 459         int list_state = 0;
 460         int i = 0;
 461
 462         if (!device || !state)
 463                 return -EINVAL;
 464
 465         /*
 466          * We know a device's inferred power state when all the resources
 467          * required for a given D-state are 'on'.
 468          */
 469         for (i = ACPI_STATE_D0; i < ACPI_STATE_D3; i++) {
 470                 list = &device->power.states[i].resources;
 471                 if (list->count < 1)
 472                         continue;
 473
 474                 result = acpi_power_get_list_state(list, &list_state);
 475                 if (result)
 476                         return result;
 477
 478                 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
 479                         *state = i;
 480                         return 0;
 481                 }
 482         }
 483
 484         *state = ACPI_STATE_D3;
 485         return 0;
 486 }
 487
 488 int acpi_power_transition(struct acpi_device *device, int state)
 489 {
 490         int result;
 491
 492         if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
 493                 return -EINVAL;
 494
 495         if (device->power.state == state)
 496                 return 0;
 497
 498         if ((device->power.state < ACPI_STATE_D0)
 499             || (device->power.state > ACPI_STATE_D3))
 500                 return -ENODEV;
 501
 502         /* TBD: Resources must be ordered. */
 503
 504         /*
 505          * First we reference all power resources required in the target list
 506          * (e.g. so the device doesn't lose power while transitioning).  Then,
 507          * we dereference all power resources used in the current list.
 508          */
 509         result = acpi_power_on_list(&device->power.states[state].resources);
 510         if (!result)
 511                 acpi_power_off_list(
 512                         &device->power.states[device->power.state].resources);
 513
 514         /* We shouldn't change the state unless the above operations succeed. */
 515         device->power.state = result ? ACPI_STATE_UNKNOWN : state;
 516
 517         return result;
 518 }
 519
 520 /* --------------------------------------------------------------------------
 521                                 Driver Interface
 522    -------------------------------------------------------------------------- */
 523
 524 static int acpi_power_add(struct acpi_device *device)
 525 {
 526         int result = 0, state;
 527         acpi_status status = AE_OK;
 528         struct acpi_power_resource *resource = NULL;
 529         union acpi_object acpi_object;
 530         struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
 531
 532
 533         if (!device)
 534                 return -EINVAL;
 535
 536         resource = kzalloc(sizeof(struct acpi_power_resource), GFP_KERNEL);
 537         if (!resource)
 538                 return -ENOMEM;
 539
 540         resource->device = device;
 541         mutex_init(&resource->resource_lock);
 542         strcpy(resource->name, device->pnp.bus_id);
 543         strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
 544         strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
 545         device->driver_data = resource;
 546
 547         /* Evalute the object to get the system level and resource order. */
 548         status = acpi_evaluate_object(device->handle, NULL, NULL, &buffer);
 549         if (ACPI_FAILURE(status)) {
 550                 result = -ENODEV;
 551                 goto end;
 552         }
 553         resource->system_level = acpi_object.power_resource.system_level;
 554         resource->order = acpi_object.power_resource.resource_order;
 555
 556         result = acpi_power_get_state(device->handle, &state);
 557         if (result)
 558                 goto end;
 559
 560         switch (state) {
 561         case ACPI_POWER_RESOURCE_STATE_ON:
 562                 device->power.state = ACPI_STATE_D0;
 563                 break;
 564         case ACPI_POWER_RESOURCE_STATE_OFF:
 565                 device->power.state = ACPI_STATE_D3;
 566                 break;
 567         default:
 568                 device->power.state = ACPI_STATE_UNKNOWN;
 569                 break;
 570         }
 571
 572         printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
 573                acpi_device_bid(device), state ? "on" : "off");
 574
 575       end:
 576         if (result)
 577                 kfree(resource);
 578
 579         return result;
 580 }
 581
 582 static int acpi_power_remove(struct acpi_device *device, int type)
 583 {
 584         struct acpi_power_resource *resource;
 585
 586         if (!device)
 587                 return -EINVAL;
 588
 589         resource = acpi_driver_data(device);
 590         if (!resource)
 591                 return -EINVAL;
 592
 593         kfree(resource);
 594
 595         return 0;
 596 }
 597
 598 static int acpi_power_resume(struct acpi_device *device)
 599 {
 600         int result = 0, state;
 601         struct acpi_power_resource *resource;
 602
 603         if (!device)
 604                 return -EINVAL;
 605
 606         resource = acpi_driver_data(device);
 607         if (!resource)
 608                 return -EINVAL;
 609
 610         mutex_lock(&resource->resource_lock);
 611
 612         result = acpi_power_get_state(device->handle, &state);
 613         if (result)
 614                 goto unlock;
 615
 616         if (state == ACPI_POWER_RESOURCE_STATE_OFF && resource->ref_count)
 617                 result = __acpi_power_on(resource);
 618
 619  unlock:
 620         mutex_unlock(&resource->resource_lock);
 621
 622         return result;
 623 }
 624
 625 int __init acpi_power_init(void)
 626 {
 627         INIT_LIST_HEAD(&acpi_power_resource_list);
 628         return acpi_bus_register_driver(&acpi_power_driver);
 629 }