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 result = 0, state1;
 149         u32 i = 0;
 150
 151
 152         if (!list || !state)
 153                 return -EINVAL;
 154
 155         /* The state of the list is 'on' IFF all resources are 'on'. */
 156
 157         for (i = 0; i < list->count; i++) {
 158                 /*
 159                  * The state of the power resource can be obtained by
 160                  * using the ACPI handle. In such case it is unnecessary to
 161                  * get the Power resource first and then get its state again.
 162                  */
 163                 result = acpi_power_get_state(list->handles[i], &state1);
 164                 if (result)
 165                         return result;
 166
 167                 *state = state1;
 168
 169                 if (*state != ACPI_POWER_RESOURCE_STATE_ON)
 170                         break;
 171         }
 172
 173         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
 174                           *state ? "on" : "off"));
 175
 176         return result;
 177 }
 178
 179 static int __acpi_power_on(struct acpi_power_resource *resource)
 180 {
 181         acpi_status status = AE_OK;
 182
 183         status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL);
 184         if (ACPI_FAILURE(status))
 185                 return -ENODEV;
 186
 187         /* Update the power resource's _device_ power state */
 188         resource->device->power.state = ACPI_STATE_D0;
 189
 190         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned on\n",
 191                           resource->name));
 192
 193         return 0;
 194 }
 195
 196 static int acpi_power_on(acpi_handle handle)
 197 {
 198         int result = 0;
 199         struct acpi_power_resource *resource = NULL;
 200
 201         result = acpi_power_get_context(handle, &resource);
 202         if (result)
 203                 return result;
 204
 205         mutex_lock(&resource->resource_lock);
 206
 207         if (resource->ref_count++) {
 208                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 209                                   "Power resource [%s] already on",
 210                                   resource->name));
 211         } else {
 212                 result = __acpi_power_on(resource);
 213                 if (result)
 214                         resource->ref_count--;
 215         }
 216
 217         mutex_unlock(&resource->resource_lock);
 218
 219         return result;
 220 }
 221
 222 static int acpi_power_off_device(acpi_handle handle)
 223 {
 224         int result = 0;
 225         acpi_status status = AE_OK;
 226         struct acpi_power_resource *resource = NULL;
 227
 228         result = acpi_power_get_context(handle, &resource);
 229         if (result)
 230                 return result;
 231
 232         mutex_lock(&resource->resource_lock);
 233
 234         if (!resource->ref_count) {
 235                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 236                                   "Power resource [%s] already off",
 237                                   resource->name));
 238                 goto unlock;
 239         }
 240
 241         if (--resource->ref_count) {
 242                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 243                                   "Power resource [%s] still in use\n",
 244                                   resource->name));
 245                 goto unlock;
 246         }
 247
 248         status = acpi_evaluate_object(resource->device->handle, "_OFF", NULL, NULL);
 249         if (ACPI_FAILURE(status)) {
 250                 result = -ENODEV;
 251         } else {
 252                 /* Update the power resource's _device_ power state */
 253                 resource->device->power.state = ACPI_STATE_D3;
 254
 255                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 256                                   "Power resource [%s] turned off\n",
 257                                   resource->name));
 258         }
 259
 260  unlock:
 261         mutex_unlock(&resource->resource_lock);
 262
 263         return result;
 264 }
 265
 266 static void __acpi_power_off_list(struct acpi_handle_list *list, int num_res)
 267 {
 268         int i;
 269
 270         for (i = num_res - 1; i >= 0 ; i--)
 271                 acpi_power_off_device(list->handles[i]);
 272 }
 273
 274 static void acpi_power_off_list(struct acpi_handle_list *list)
 275 {
 276         __acpi_power_off_list(list, list->count);
 277 }
 278
 279 static int acpi_power_on_list(struct acpi_handle_list *list)
 280 {
 281         int result = 0;
 282         int i;
 283
 284         for (i = 0; i < list->count; i++) {
 285                 result = acpi_power_on(list->handles[i]);
 286                 if (result) {
 287                         __acpi_power_off_list(list, i);
 288                         break;
 289                 }
 290         }
 291
 292         return result;
 293 }
 294
 295 /**
 296  * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
 297  *                          ACPI 3.0) _PSW (Power State Wake)
 298  * @dev: Device to handle.
 299  * @enable: 0 - disable, 1 - enable the wake capabilities of the device.
 300  * @sleep_state: Target sleep state of the system.
 301  * @dev_state: Target power state of the device.
 302  *
 303  * Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 304  * State Wake) for the device, if present.  On failure reset the device's
 305  * wakeup.flags.valid flag.
 306  *
 307  * RETURN VALUE:
 308  * 0 if either _DSW or _PSW has been successfully executed
 309  * 0 if neither _DSW nor _PSW has been found
 310  * -ENODEV if the execution of either _DSW or _PSW has failed
 311  */
 312 int acpi_device_sleep_wake(struct acpi_device *dev,
 313                            int enable, int sleep_state, int dev_state)
 314 {
 315         union acpi_object in_arg[3];
 316         struct acpi_object_list arg_list = { 3, in_arg };
 317         acpi_status status = AE_OK;
 318
 319         /*
 320          * Try to execute _DSW first.
 321          *
 322          * Three agruments are needed for the _DSW object:
 323          * Argument 0: enable/disable the wake capabilities
 324          * Argument 1: target system state
 325          * Argument 2: target device state
 326          * When _DSW object is called to disable the wake capabilities, maybe
 327          * the first argument is filled. The values of the other two agruments
 328          * are meaningless.
 329          */
 330         in_arg[0].type = ACPI_TYPE_INTEGER;
 331         in_arg[0].integer.value = enable;
 332         in_arg[1].type = ACPI_TYPE_INTEGER;
 333         in_arg[1].integer.value = sleep_state;
 334         in_arg[2].type = ACPI_TYPE_INTEGER;
 335         in_arg[2].integer.value = dev_state;
 336         status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
 337         if (ACPI_SUCCESS(status)) {
 338                 return 0;
 339         } else if (status != AE_NOT_FOUND) {
 340                 printk(KERN_ERR PREFIX "_DSW execution failed\n");
 341                 dev->wakeup.flags.valid = 0;
 342                 return -ENODEV;
 343         }
 344
 345         /* Execute _PSW */
 346         arg_list.count = 1;
 347         in_arg[0].integer.value = enable;
 348         status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
 349         if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
 350                 printk(KERN_ERR PREFIX "_PSW execution failed\n");
 351                 dev->wakeup.flags.valid = 0;
 352                 return -ENODEV;
 353         }
 354
 355         return 0;
 356 }
 357
 358 /*
 359  * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
 360  * 1. Power on the power resources required for the wakeup device
 361  * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 362  *    State Wake) for the device, if present
 363  */
 364 int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
 365 {
 366         int i, err = 0;
 367
 368         if (!dev || !dev->wakeup.flags.valid)
 369                 return -EINVAL;
 370
 371         mutex_lock(&acpi_device_lock);
 372
 373         if (dev->wakeup.prepare_count++)
 374                 goto out;
 375
 376         /* Open power resource */
 377         for (i = 0; i < dev->wakeup.resources.count; i++) {
 378                 int ret = acpi_power_on(dev->wakeup.resources.handles[i]);
 379                 if (ret) {
 380                         printk(KERN_ERR PREFIX "Transition power state\n");
 381                         dev->wakeup.flags.valid = 0;
 382                         err = -ENODEV;
 383                         goto err_out;
 384                 }
 385         }
 386
 387         /*
 388          * Passing 3 as the third argument below means the device may be placed
 389          * in arbitrary power state afterwards.
 390          */
 391         err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
 392
 393  err_out:
 394         if (err)
 395                 dev->wakeup.prepare_count = 0;
 396
 397  out:
 398         mutex_unlock(&acpi_device_lock);
 399         return err;
 400 }
 401
 402 /*
 403  * Shutdown a wakeup device, counterpart of above method
 404  * 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
 405  *    State Wake) for the device, if present
 406  * 2. Shutdown down the power resources
 407  */
 408 int acpi_disable_wakeup_device_power(struct acpi_device *dev)
 409 {
 410         int i, err = 0;
 411
 412         if (!dev || !dev->wakeup.flags.valid)
 413                 return -EINVAL;
 414
 415         mutex_lock(&acpi_device_lock);
 416
 417         if (--dev->wakeup.prepare_count > 0)
 418                 goto out;
 419
 420         /*
 421          * Executing the code below even if prepare_count is already zero when
 422          * the function is called may be useful, for example for initialisation.
 423          */
 424         if (dev->wakeup.prepare_count < 0)
 425                 dev->wakeup.prepare_count = 0;
 426
 427         err = acpi_device_sleep_wake(dev, 0, 0, 0);
 428         if (err)
 429                 goto out;
 430
 431         /* Close power resource */
 432         for (i = 0; i < dev->wakeup.resources.count; i++) {
 433                 int ret = acpi_power_off_device(
 434                                 dev->wakeup.resources.handles[i]);
 435                 if (ret) {
 436                         printk(KERN_ERR PREFIX "Transition power state\n");
 437                         dev->wakeup.flags.valid = 0;
 438                         err = -ENODEV;
 439                         goto out;
 440                 }
 441         }
 442
 443  out:
 444         mutex_unlock(&acpi_device_lock);
 445         return err;
 446 }
 447
 448 /* --------------------------------------------------------------------------
 449                              Device Power Management
 450    -------------------------------------------------------------------------- */
 451
 452 int acpi_power_get_inferred_state(struct acpi_device *device, int *state)
 453 {
 454         int result = 0;
 455         struct acpi_handle_list *list = NULL;
 456         int list_state = 0;
 457         int i = 0;
 458
 459         if (!device || !state)
 460                 return -EINVAL;
 461
 462         /*
 463          * We know a device's inferred power state when all the resources
 464          * required for a given D-state are 'on'.
 465          */
 466         for (i = ACPI_STATE_D0; i < ACPI_STATE_D3; i++) {
 467                 list = &device->power.states[i].resources;
 468                 if (list->count < 1)
 469                         continue;
 470
 471                 result = acpi_power_get_list_state(list, &list_state);
 472                 if (result)
 473                         return result;
 474
 475                 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
 476                         *state = i;
 477                         return 0;
 478                 }
 479         }
 480
 481         *state = ACPI_STATE_D3;
 482         return 0;
 483 }
 484
 485 int acpi_power_on_resources(struct acpi_device *device, int state)
 486 {
 487         if (!device || state < ACPI_STATE_D0 || state > ACPI_STATE_D3)
 488                 return -EINVAL;
 489
 490         return acpi_power_on_list(&device->power.states[state].resources);
 491 }
 492
 493 int acpi_power_transition(struct acpi_device *device, int state)
 494 {
 495         int result;
 496
 497         if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
 498                 return -EINVAL;
 499
 500         if (device->power.state == state)
 501                 return 0;
 502
 503         if ((device->power.state < ACPI_STATE_D0)
 504             || (device->power.state > ACPI_STATE_D3))
 505                 return -ENODEV;
 506
 507         /* TBD: Resources must be ordered. */
 508
 509         /*
 510          * First we reference all power resources required in the target list
 511          * (e.g. so the device doesn't lose power while transitioning).  Then,
 512          * we dereference all power resources used in the current list.
 513          */
 514         result = acpi_power_on_list(&device->power.states[state].resources);
 515         if (!result)
 516                 acpi_power_off_list(
 517                         &device->power.states[device->power.state].resources);
 518
 519         /* We shouldn't change the state unless the above operations succeed. */
 520         device->power.state = result ? ACPI_STATE_UNKNOWN : state;
 521
 522         return result;
 523 }
 524
 525 /* --------------------------------------------------------------------------
 526                                 Driver Interface
 527    -------------------------------------------------------------------------- */
 528
 529 static int acpi_power_add(struct acpi_device *device)
 530 {
 531         int result = 0, state;
 532         acpi_status status = AE_OK;
 533         struct acpi_power_resource *resource = NULL;
 534         union acpi_object acpi_object;
 535         struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
 536
 537
 538         if (!device)
 539                 return -EINVAL;
 540
 541         resource = kzalloc(sizeof(struct acpi_power_resource), GFP_KERNEL);
 542         if (!resource)
 543                 return -ENOMEM;
 544
 545         resource->device = device;
 546         mutex_init(&resource->resource_lock);
 547         strcpy(resource->name, device->pnp.bus_id);
 548         strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
 549         strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
 550         device->driver_data = resource;
 551
 552         /* Evalute the object to get the system level and resource order. */
 553         status = acpi_evaluate_object(device->handle, NULL, NULL, &buffer);
 554         if (ACPI_FAILURE(status)) {
 555                 result = -ENODEV;
 556                 goto end;
 557         }
 558         resource->system_level = acpi_object.power_resource.system_level;
 559         resource->order = acpi_object.power_resource.resource_order;
 560
 561         result = acpi_power_get_state(device->handle, &state);
 562         if (result)
 563                 goto end;
 564
 565         switch (state) {
 566         case ACPI_POWER_RESOURCE_STATE_ON:
 567                 device->power.state = ACPI_STATE_D0;
 568                 break;
 569         case ACPI_POWER_RESOURCE_STATE_OFF:
 570                 device->power.state = ACPI_STATE_D3;
 571                 break;
 572         default:
 573                 device->power.state = ACPI_STATE_UNKNOWN;
 574                 break;
 575         }
 576
 577         printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
 578                acpi_device_bid(device), state ? "on" : "off");
 579
 580       end:
 581         if (result)
 582                 kfree(resource);
 583
 584         return result;
 585 }
 586
 587 static int acpi_power_remove(struct acpi_device *device, int type)
 588 {
 589         struct acpi_power_resource *resource;
 590
 591         if (!device)
 592                 return -EINVAL;
 593
 594         resource = acpi_driver_data(device);
 595         if (!resource)
 596                 return -EINVAL;
 597
 598         kfree(resource);
 599
 600         return 0;
 601 }
 602
 603 static int acpi_power_resume(struct acpi_device *device)
 604 {
 605         int result = 0, state;
 606         struct acpi_power_resource *resource;
 607
 608         if (!device)
 609                 return -EINVAL;
 610
 611         resource = acpi_driver_data(device);
 612         if (!resource)
 613                 return -EINVAL;
 614
 615         mutex_lock(&resource->resource_lock);
 616
 617         result = acpi_power_get_state(device->handle, &state);
 618         if (result)
 619                 goto unlock;
 620
 621         if (state == ACPI_POWER_RESOURCE_STATE_OFF && resource->ref_count)
 622                 result = __acpi_power_on(resource);
 623
 624  unlock:
 625         mutex_unlock(&resource->resource_lock);
 626
 627         return result;
 628 }
 629
 630 int __init acpi_power_init(void)
 631 {
 632         INIT_LIST_HEAD(&acpi_power_resource_list);
 633         return acpi_bus_register_driver(&acpi_power_driver);
 634 }