linux/drivers/acpi/device_pm.c
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   1/*
   2 * drivers/acpi/device_pm.c - ACPI device power management routines.
   3 *
   4 * Copyright (C) 2012, Intel Corp.
   5 * Author: Rafael J. Wysocki <rafael.j.wysocki@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 version 2 as published
  11 *  by the Free Software Foundation.
  12 *
  13 *  This program is distributed in the hope that it will be useful, but
  14 *  WITHOUT ANY WARRANTY; without even the implied warranty of
  15 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16 *  General Public License for more details.
  17 *
  18 *  You should have received a copy of the GNU General Public License along
  19 *  with this program; if not, write to the Free Software Foundation, Inc.,
  20 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  21 *
  22 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  23 */
  24
  25#include <linux/device.h>
  26#include <linux/export.h>
  27#include <linux/mutex.h>
  28#include <linux/pm_qos.h>
  29#include <linux/pm_runtime.h>
  30
  31#include <acpi/acpi.h>
  32#include <acpi/acpi_bus.h>
  33#include <acpi/acpi_drivers.h>
  34
  35#include "internal.h"
  36
  37#define _COMPONENT      ACPI_POWER_COMPONENT
  38ACPI_MODULE_NAME("device_pm");
  39
  40/**
  41 * acpi_power_state_string - String representation of ACPI device power state.
  42 * @state: ACPI device power state to return the string representation of.
  43 */
  44const char *acpi_power_state_string(int state)
  45{
  46        switch (state) {
  47        case ACPI_STATE_D0:
  48                return "D0";
  49        case ACPI_STATE_D1:
  50                return "D1";
  51        case ACPI_STATE_D2:
  52                return "D2";
  53        case ACPI_STATE_D3_HOT:
  54                return "D3hot";
  55        case ACPI_STATE_D3_COLD:
  56                return "D3cold";
  57        default:
  58                return "(unknown)";
  59        }
  60}
  61
  62/**
  63 * acpi_device_get_power - Get power state of an ACPI device.
  64 * @device: Device to get the power state of.
  65 * @state: Place to store the power state of the device.
  66 *
  67 * This function does not update the device's power.state field, but it may
  68 * update its parent's power.state field (when the parent's power state is
  69 * unknown and the device's power state turns out to be D0).
  70 */
  71int acpi_device_get_power(struct acpi_device *device, int *state)
  72{
  73        int result = ACPI_STATE_UNKNOWN;
  74
  75        if (!device || !state)
  76                return -EINVAL;
  77
  78        if (!device->flags.power_manageable) {
  79                /* TBD: Non-recursive algorithm for walking up hierarchy. */
  80                *state = device->parent ?
  81                        device->parent->power.state : ACPI_STATE_D0;
  82                goto out;
  83        }
  84
  85        /*
  86         * Get the device's power state from power resources settings and _PSC,
  87         * if available.
  88         */
  89        if (device->power.flags.power_resources) {
  90                int error = acpi_power_get_inferred_state(device, &result);
  91                if (error)
  92                        return error;
  93        }
  94        if (device->power.flags.explicit_get) {
  95                acpi_handle handle = device->handle;
  96                unsigned long long psc;
  97                acpi_status status;
  98
  99                status = acpi_evaluate_integer(handle, "_PSC", NULL, &psc);
 100                if (ACPI_FAILURE(status))
 101                        return -ENODEV;
 102
 103                /*
 104                 * The power resources settings may indicate a power state
 105                 * shallower than the actual power state of the device.
 106                 *
 107                 * Moreover, on systems predating ACPI 4.0, if the device
 108                 * doesn't depend on any power resources and _PSC returns 3,
 109                 * that means "power off".  We need to maintain compatibility
 110                 * with those systems.
 111                 */
 112                if (psc > result && psc < ACPI_STATE_D3_COLD)
 113                        result = psc;
 114                else if (result == ACPI_STATE_UNKNOWN)
 115                        result = psc > ACPI_STATE_D2 ? ACPI_STATE_D3_COLD : psc;
 116        }
 117
 118        /*
 119         * If we were unsure about the device parent's power state up to this
 120         * point, the fact that the device is in D0 implies that the parent has
 121         * to be in D0 too.
 122         */
 123        if (device->parent && device->parent->power.state == ACPI_STATE_UNKNOWN
 124            && result == ACPI_STATE_D0)
 125                device->parent->power.state = ACPI_STATE_D0;
 126
 127        *state = result;
 128
 129 out:
 130        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is %s\n",
 131                          device->pnp.bus_id, acpi_power_state_string(*state)));
 132
 133        return 0;
 134}
 135
 136static int acpi_dev_pm_explicit_set(struct acpi_device *adev, int state)
 137{
 138        if (adev->power.states[state].flags.explicit_set) {
 139                char method[5] = { '_', 'P', 'S', '0' + state, '\0' };
 140                acpi_status status;
 141
 142                status = acpi_evaluate_object(adev->handle, method, NULL, NULL);
 143                if (ACPI_FAILURE(status))
 144                        return -ENODEV;
 145        }
 146        return 0;
 147}
 148
 149/**
 150 * acpi_device_set_power - Set power state of an ACPI device.
 151 * @device: Device to set the power state of.
 152 * @state: New power state to set.
 153 *
 154 * Callers must ensure that the device is power manageable before using this
 155 * function.
 156 */
 157int acpi_device_set_power(struct acpi_device *device, int state)
 158{
 159        int result = 0;
 160        bool cut_power = false;
 161
 162        if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
 163                return -EINVAL;
 164
 165        /* Make sure this is a valid target state */
 166
 167        if (state == device->power.state) {
 168                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device is already at %s\n",
 169                                  acpi_power_state_string(state)));
 170                return 0;
 171        }
 172
 173        if (!device->power.states[state].flags.valid) {
 174                printk(KERN_WARNING PREFIX "Device does not support %s\n",
 175                       acpi_power_state_string(state));
 176                return -ENODEV;
 177        }
 178        if (device->parent && (state < device->parent->power.state)) {
 179                printk(KERN_WARNING PREFIX
 180                              "Cannot set device to a higher-powered"
 181                              " state than parent\n");
 182                return -ENODEV;
 183        }
 184
 185        /* For D3cold we should first transition into D3hot. */
 186        if (state == ACPI_STATE_D3_COLD
 187            && device->power.states[ACPI_STATE_D3_COLD].flags.os_accessible) {
 188                state = ACPI_STATE_D3_HOT;
 189                cut_power = true;
 190        }
 191
 192        if (state < device->power.state && state != ACPI_STATE_D0
 193            && device->power.state >= ACPI_STATE_D3_HOT) {
 194                printk(KERN_WARNING PREFIX
 195                        "Cannot transition to non-D0 state from D3\n");
 196                return -ENODEV;
 197        }
 198
 199        /*
 200         * Transition Power
 201         * ----------------
 202         * In accordance with the ACPI specification first apply power (via
 203         * power resources) and then evalute _PSx.
 204         */
 205        if (device->power.flags.power_resources) {
 206                result = acpi_power_transition(device, state);
 207                if (result)
 208                        goto end;
 209        }
 210        result = acpi_dev_pm_explicit_set(device, state);
 211        if (result)
 212                goto end;
 213
 214        if (cut_power) {
 215                device->power.state = state;
 216                state = ACPI_STATE_D3_COLD;
 217                result = acpi_power_transition(device, state);
 218        }
 219
 220 end:
 221        if (result) {
 222                printk(KERN_WARNING PREFIX
 223                              "Device [%s] failed to transition to %s\n",
 224                              device->pnp.bus_id,
 225                              acpi_power_state_string(state));
 226        } else {
 227                device->power.state = state;
 228                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 229                                  "Device [%s] transitioned to %s\n",
 230                                  device->pnp.bus_id,
 231                                  acpi_power_state_string(state)));
 232        }
 233
 234        return result;
 235}
 236EXPORT_SYMBOL(acpi_device_set_power);
 237
 238int acpi_bus_set_power(acpi_handle handle, int state)
 239{
 240        struct acpi_device *device;
 241        int result;
 242
 243        result = acpi_bus_get_device(handle, &device);
 244        if (result)
 245                return result;
 246
 247        if (!device->flags.power_manageable) {
 248                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 249                                "Device [%s] is not power manageable\n",
 250                                dev_name(&device->dev)));
 251                return -ENODEV;
 252        }
 253
 254        return acpi_device_set_power(device, state);
 255}
 256EXPORT_SYMBOL(acpi_bus_set_power);
 257
 258int acpi_bus_init_power(struct acpi_device *device)
 259{
 260        int state;
 261        int result;
 262
 263        if (!device)
 264                return -EINVAL;
 265
 266        device->power.state = ACPI_STATE_UNKNOWN;
 267
 268        result = acpi_device_get_power(device, &state);
 269        if (result)
 270                return result;
 271
 272        if (state < ACPI_STATE_D3_COLD && device->power.flags.power_resources) {
 273                result = acpi_power_on_resources(device, state);
 274                if (result)
 275                        return result;
 276
 277                result = acpi_dev_pm_explicit_set(device, state);
 278                if (result)
 279                        return result;
 280        } else if (state == ACPI_STATE_UNKNOWN) {
 281                /*
 282                 * No power resources and missing _PSC?  Cross fingers and make
 283                 * it D0 in hope that this is what the BIOS put the device into.
 284                 * [We tried to force D0 here by executing _PS0, but that broke
 285                 * Toshiba P870-303 in a nasty way.]
 286                 */
 287                state = ACPI_STATE_D0;
 288        }
 289        device->power.state = state;
 290        return 0;
 291}
 292
 293/**
 294 * acpi_device_fix_up_power - Force device with missing _PSC into D0.
 295 * @device: Device object whose power state is to be fixed up.
 296 *
 297 * Devices without power resources and _PSC, but having _PS0 and _PS3 defined,
 298 * are assumed to be put into D0 by the BIOS.  However, in some cases that may
 299 * not be the case and this function should be used then.
 300 */
 301int acpi_device_fix_up_power(struct acpi_device *device)
 302{
 303        int ret = 0;
 304
 305        if (!device->power.flags.power_resources
 306            && !device->power.flags.explicit_get
 307            && device->power.state == ACPI_STATE_D0)
 308                ret = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0);
 309
 310        return ret;
 311}
 312
 313int acpi_bus_update_power(acpi_handle handle, int *state_p)
 314{
 315        struct acpi_device *device;
 316        int state;
 317        int result;
 318
 319        result = acpi_bus_get_device(handle, &device);
 320        if (result)
 321                return result;
 322
 323        result = acpi_device_get_power(device, &state);
 324        if (result)
 325                return result;
 326
 327        if (state == ACPI_STATE_UNKNOWN)
 328                state = ACPI_STATE_D0;
 329
 330        result = acpi_device_set_power(device, state);
 331        if (!result && state_p)
 332                *state_p = state;
 333
 334        return result;
 335}
 336EXPORT_SYMBOL_GPL(acpi_bus_update_power);
 337
 338bool acpi_bus_power_manageable(acpi_handle handle)
 339{
 340        struct acpi_device *device;
 341        int result;
 342
 343        result = acpi_bus_get_device(handle, &device);
 344        return result ? false : device->flags.power_manageable;
 345}
 346EXPORT_SYMBOL(acpi_bus_power_manageable);
 347
 348#ifdef CONFIG_PM
 349static DEFINE_MUTEX(acpi_pm_notifier_lock);
 350
 351/**
 352 * acpi_add_pm_notifier - Register PM notifier for given ACPI device.
 353 * @adev: ACPI device to add the notifier for.
 354 * @context: Context information to pass to the notifier routine.
 355 *
 356 * NOTE: @adev need not be a run-wake or wakeup device to be a valid source of
 357 * PM wakeup events.  For example, wakeup events may be generated for bridges
 358 * if one of the devices below the bridge is signaling wakeup, even if the
 359 * bridge itself doesn't have a wakeup GPE associated with it.
 360 */
 361acpi_status acpi_add_pm_notifier(struct acpi_device *adev,
 362                                 acpi_notify_handler handler, void *context)
 363{
 364        acpi_status status = AE_ALREADY_EXISTS;
 365
 366        mutex_lock(&acpi_pm_notifier_lock);
 367
 368        if (adev->wakeup.flags.notifier_present)
 369                goto out;
 370
 371        status = acpi_install_notify_handler(adev->handle,
 372                                             ACPI_SYSTEM_NOTIFY,
 373                                             handler, context);
 374        if (ACPI_FAILURE(status))
 375                goto out;
 376
 377        adev->wakeup.flags.notifier_present = true;
 378
 379 out:
 380        mutex_unlock(&acpi_pm_notifier_lock);
 381        return status;
 382}
 383
 384/**
 385 * acpi_remove_pm_notifier - Unregister PM notifier from given ACPI device.
 386 * @adev: ACPI device to remove the notifier from.
 387 */
 388acpi_status acpi_remove_pm_notifier(struct acpi_device *adev,
 389                                    acpi_notify_handler handler)
 390{
 391        acpi_status status = AE_BAD_PARAMETER;
 392
 393        mutex_lock(&acpi_pm_notifier_lock);
 394
 395        if (!adev->wakeup.flags.notifier_present)
 396                goto out;
 397
 398        status = acpi_remove_notify_handler(adev->handle,
 399                                            ACPI_SYSTEM_NOTIFY,
 400                                            handler);
 401        if (ACPI_FAILURE(status))
 402                goto out;
 403
 404        adev->wakeup.flags.notifier_present = false;
 405
 406 out:
 407        mutex_unlock(&acpi_pm_notifier_lock);
 408        return status;
 409}
 410
 411bool acpi_bus_can_wakeup(acpi_handle handle)
 412{
 413        struct acpi_device *device;
 414        int result;
 415
 416        result = acpi_bus_get_device(handle, &device);
 417        return result ? false : device->wakeup.flags.valid;
 418}
 419EXPORT_SYMBOL(acpi_bus_can_wakeup);
 420
 421/**
 422 * acpi_device_power_state - Get preferred power state of ACPI device.
 423 * @dev: Device whose preferred target power state to return.
 424 * @adev: ACPI device node corresponding to @dev.
 425 * @target_state: System state to match the resultant device state.
 426 * @d_max_in: Deepest low-power state to take into consideration.
 427 * @d_min_p: Location to store the upper limit of the allowed states range.
 428 * Return value: Preferred power state of the device on success, -ENODEV
 429 * (if there's no 'struct acpi_device' for @dev) or -EINVAL on failure
 430 *
 431 * Find the lowest power (highest number) ACPI device power state that the
 432 * device can be in while the system is in the state represented by
 433 * @target_state.  If @d_min_p is set, the highest power (lowest number) device
 434 * power state that @dev can be in for the given system sleep state is stored
 435 * at the location pointed to by it.
 436 *
 437 * Callers must ensure that @dev and @adev are valid pointers and that @adev
 438 * actually corresponds to @dev before using this function.
 439 */
 440int acpi_device_power_state(struct device *dev, struct acpi_device *adev,
 441                            u32 target_state, int d_max_in, int *d_min_p)
 442{
 443        char acpi_method[] = "_SxD";
 444        unsigned long long d_min, d_max;
 445        bool wakeup = false;
 446
 447        if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3)
 448                return -EINVAL;
 449
 450        if (d_max_in > ACPI_STATE_D3_HOT) {
 451                enum pm_qos_flags_status stat;
 452
 453                stat = dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF);
 454                if (stat == PM_QOS_FLAGS_ALL)
 455                        d_max_in = ACPI_STATE_D3_HOT;
 456        }
 457
 458        acpi_method[2] = '0' + target_state;
 459        /*
 460         * If the sleep state is S0, the lowest limit from ACPI is D3,
 461         * but if the device has _S0W, we will use the value from _S0W
 462         * as the lowest limit from ACPI.  Finally, we will constrain
 463         * the lowest limit with the specified one.
 464         */
 465        d_min = ACPI_STATE_D0;
 466        d_max = ACPI_STATE_D3;
 467
 468        /*
 469         * If present, _SxD methods return the minimum D-state (highest power
 470         * state) we can use for the corresponding S-states.  Otherwise, the
 471         * minimum D-state is D0 (ACPI 3.x).
 472         *
 473         * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
 474         * provided -- that's our fault recovery, we ignore retval.
 475         */
 476        if (target_state > ACPI_STATE_S0) {
 477                acpi_evaluate_integer(adev->handle, acpi_method, NULL, &d_min);
 478                wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
 479                        && adev->wakeup.sleep_state >= target_state;
 480        } else if (dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) !=
 481                        PM_QOS_FLAGS_NONE) {
 482                wakeup = adev->wakeup.flags.valid;
 483        }
 484
 485        /*
 486         * If _PRW says we can wake up the system from the target sleep state,
 487         * the D-state returned by _SxD is sufficient for that (we assume a
 488         * wakeup-aware driver if wake is set).  Still, if _SxW exists
 489         * (ACPI 3.x), it should return the maximum (lowest power) D-state that
 490         * can wake the system.  _S0W may be valid, too.
 491         */
 492        if (wakeup) {
 493                acpi_status status;
 494
 495                acpi_method[3] = 'W';
 496                status = acpi_evaluate_integer(adev->handle, acpi_method, NULL,
 497                                                &d_max);
 498                if (ACPI_FAILURE(status)) {
 499                        if (target_state != ACPI_STATE_S0 ||
 500                            status != AE_NOT_FOUND)
 501                                d_max = d_min;
 502                } else if (d_max < d_min) {
 503                        /* Warn the user of the broken DSDT */
 504                        printk(KERN_WARNING "ACPI: Wrong value from %s\n",
 505                                acpi_method);
 506                        /* Sanitize it */
 507                        d_min = d_max;
 508                }
 509        }
 510
 511        if (d_max_in < d_min)
 512                return -EINVAL;
 513        if (d_min_p)
 514                *d_min_p = d_min;
 515        /* constrain d_max with specified lowest limit (max number) */
 516        if (d_max > d_max_in) {
 517                for (d_max = d_max_in; d_max > d_min; d_max--) {
 518                        if (adev->power.states[d_max].flags.valid)
 519                                break;
 520                }
 521        }
 522        return d_max;
 523}
 524EXPORT_SYMBOL_GPL(acpi_device_power_state);
 525
 526/**
 527 * acpi_pm_device_sleep_state - Get preferred power state of ACPI device.
 528 * @dev: Device whose preferred target power state to return.
 529 * @d_min_p: Location to store the upper limit of the allowed states range.
 530 * @d_max_in: Deepest low-power state to take into consideration.
 531 * Return value: Preferred power state of the device on success, -ENODEV
 532 * (if there's no 'struct acpi_device' for @dev) or -EINVAL on failure
 533 *
 534 * The caller must ensure that @dev is valid before using this function.
 535 */
 536int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p, int d_max_in)
 537{
 538        acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
 539        struct acpi_device *adev;
 540
 541        if (!handle || acpi_bus_get_device(handle, &adev)) {
 542                dev_dbg(dev, "ACPI handle without context in %s!\n", __func__);
 543                return -ENODEV;
 544        }
 545
 546        return acpi_device_power_state(dev, adev, acpi_target_system_state(),
 547                                       d_max_in, d_min_p);
 548}
 549EXPORT_SYMBOL(acpi_pm_device_sleep_state);
 550
 551#ifdef CONFIG_PM_RUNTIME
 552/**
 553 * acpi_wakeup_device - Wakeup notification handler for ACPI devices.
 554 * @handle: ACPI handle of the device the notification is for.
 555 * @event: Type of the signaled event.
 556 * @context: Device corresponding to @handle.
 557 */
 558static void acpi_wakeup_device(acpi_handle handle, u32 event, void *context)
 559{
 560        struct device *dev = context;
 561
 562        if (event == ACPI_NOTIFY_DEVICE_WAKE && dev) {
 563                pm_wakeup_event(dev, 0);
 564                pm_runtime_resume(dev);
 565        }
 566}
 567
 568/**
 569 * __acpi_device_run_wake - Enable/disable runtime remote wakeup for device.
 570 * @adev: ACPI device to enable/disable the remote wakeup for.
 571 * @enable: Whether to enable or disable the wakeup functionality.
 572 *
 573 * Enable/disable the GPE associated with @adev so that it can generate
 574 * wakeup signals for the device in response to external (remote) events and
 575 * enable/disable device wakeup power.
 576 *
 577 * Callers must ensure that @adev is a valid ACPI device node before executing
 578 * this function.
 579 */
 580int __acpi_device_run_wake(struct acpi_device *adev, bool enable)
 581{
 582        struct acpi_device_wakeup *wakeup = &adev->wakeup;
 583
 584        if (enable) {
 585                acpi_status res;
 586                int error;
 587
 588                error = acpi_enable_wakeup_device_power(adev, ACPI_STATE_S0);
 589                if (error)
 590                        return error;
 591
 592                res = acpi_enable_gpe(wakeup->gpe_device, wakeup->gpe_number);
 593                if (ACPI_FAILURE(res)) {
 594                        acpi_disable_wakeup_device_power(adev);
 595                        return -EIO;
 596                }
 597        } else {
 598                acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number);
 599                acpi_disable_wakeup_device_power(adev);
 600        }
 601        return 0;
 602}
 603
 604/**
 605 * acpi_pm_device_run_wake - Enable/disable remote wakeup for given device.
 606 * @dev: Device to enable/disable the platform to wake up.
 607 * @enable: Whether to enable or disable the wakeup functionality.
 608 */
 609int acpi_pm_device_run_wake(struct device *phys_dev, bool enable)
 610{
 611        struct acpi_device *adev;
 612        acpi_handle handle;
 613
 614        if (!device_run_wake(phys_dev))
 615                return -EINVAL;
 616
 617        handle = DEVICE_ACPI_HANDLE(phys_dev);
 618        if (!handle || acpi_bus_get_device(handle, &adev)) {
 619                dev_dbg(phys_dev, "ACPI handle without context in %s!\n",
 620                        __func__);
 621                return -ENODEV;
 622        }
 623
 624        return __acpi_device_run_wake(adev, enable);
 625}
 626EXPORT_SYMBOL(acpi_pm_device_run_wake);
 627#else
 628static inline void acpi_wakeup_device(acpi_handle handle, u32 event,
 629                                      void *context) {}
 630#endif /* CONFIG_PM_RUNTIME */
 631
 632#ifdef CONFIG_PM_SLEEP
 633/**
 634 * __acpi_device_sleep_wake - Enable or disable device to wake up the system.
 635 * @dev: Device to enable/desible to wake up the system.
 636 * @target_state: System state the device is supposed to wake up from.
 637 * @enable: Whether to enable or disable @dev to wake up the system.
 638 */
 639int __acpi_device_sleep_wake(struct acpi_device *adev, u32 target_state,
 640                             bool enable)
 641{
 642        return enable ?
 643                acpi_enable_wakeup_device_power(adev, target_state) :
 644                acpi_disable_wakeup_device_power(adev);
 645}
 646
 647/**
 648 * acpi_pm_device_sleep_wake - Enable or disable device to wake up the system.
 649 * @dev: Device to enable/desible to wake up the system from sleep states.
 650 * @enable: Whether to enable or disable @dev to wake up the system.
 651 */
 652int acpi_pm_device_sleep_wake(struct device *dev, bool enable)
 653{
 654        acpi_handle handle;
 655        struct acpi_device *adev;
 656        int error;
 657
 658        if (!device_can_wakeup(dev))
 659                return -EINVAL;
 660
 661        handle = DEVICE_ACPI_HANDLE(dev);
 662        if (!handle || acpi_bus_get_device(handle, &adev)) {
 663                dev_dbg(dev, "ACPI handle without context in %s!\n", __func__);
 664                return -ENODEV;
 665        }
 666
 667        error = __acpi_device_sleep_wake(adev, acpi_target_system_state(),
 668                                         enable);
 669        if (!error)
 670                dev_info(dev, "System wakeup %s by ACPI\n",
 671                                enable ? "enabled" : "disabled");
 672
 673        return error;
 674}
 675#endif /* CONFIG_PM_SLEEP */
 676
 677/**
 678 * acpi_dev_pm_get_node - Get ACPI device node for the given physical device.
 679 * @dev: Device to get the ACPI node for.
 680 */
 681struct acpi_device *acpi_dev_pm_get_node(struct device *dev)
 682{
 683        acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
 684        struct acpi_device *adev;
 685
 686        return handle && !acpi_bus_get_device(handle, &adev) ? adev : NULL;
 687}
 688
 689/**
 690 * acpi_dev_pm_low_power - Put ACPI device into a low-power state.
 691 * @dev: Device to put into a low-power state.
 692 * @adev: ACPI device node corresponding to @dev.
 693 * @system_state: System state to choose the device state for.
 694 */
 695static int acpi_dev_pm_low_power(struct device *dev, struct acpi_device *adev,
 696                                 u32 system_state)
 697{
 698        int power_state;
 699
 700        if (!acpi_device_power_manageable(adev))
 701                return 0;
 702
 703        power_state = acpi_device_power_state(dev, adev, system_state,
 704                                              ACPI_STATE_D3, NULL);
 705        if (power_state < ACPI_STATE_D0 || power_state > ACPI_STATE_D3)
 706                return -EIO;
 707
 708        return acpi_device_set_power(adev, power_state);
 709}
 710
 711/**
 712 * acpi_dev_pm_full_power - Put ACPI device into the full-power state.
 713 * @adev: ACPI device node to put into the full-power state.
 714 */
 715static int acpi_dev_pm_full_power(struct acpi_device *adev)
 716{
 717        return acpi_device_power_manageable(adev) ?
 718                acpi_device_set_power(adev, ACPI_STATE_D0) : 0;
 719}
 720
 721#ifdef CONFIG_PM_RUNTIME
 722/**
 723 * acpi_dev_runtime_suspend - Put device into a low-power state using ACPI.
 724 * @dev: Device to put into a low-power state.
 725 *
 726 * Put the given device into a runtime low-power state using the standard ACPI
 727 * mechanism.  Set up remote wakeup if desired, choose the state to put the
 728 * device into (this checks if remote wakeup is expected to work too), and set
 729 * the power state of the device.
 730 */
 731int acpi_dev_runtime_suspend(struct device *dev)
 732{
 733        struct acpi_device *adev = acpi_dev_pm_get_node(dev);
 734        bool remote_wakeup;
 735        int error;
 736
 737        if (!adev)
 738                return 0;
 739
 740        remote_wakeup = dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) >
 741                                PM_QOS_FLAGS_NONE;
 742        error = __acpi_device_run_wake(adev, remote_wakeup);
 743        if (remote_wakeup && error)
 744                return -EAGAIN;
 745
 746        error = acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0);
 747        if (error)
 748                __acpi_device_run_wake(adev, false);
 749
 750        return error;
 751}
 752EXPORT_SYMBOL_GPL(acpi_dev_runtime_suspend);
 753
 754/**
 755 * acpi_dev_runtime_resume - Put device into the full-power state using ACPI.
 756 * @dev: Device to put into the full-power state.
 757 *
 758 * Put the given device into the full-power state using the standard ACPI
 759 * mechanism at run time.  Set the power state of the device to ACPI D0 and
 760 * disable remote wakeup.
 761 */
 762int acpi_dev_runtime_resume(struct device *dev)
 763{
 764        struct acpi_device *adev = acpi_dev_pm_get_node(dev);
 765        int error;
 766
 767        if (!adev)
 768                return 0;
 769
 770        error = acpi_dev_pm_full_power(adev);
 771        __acpi_device_run_wake(adev, false);
 772        return error;
 773}
 774EXPORT_SYMBOL_GPL(acpi_dev_runtime_resume);
 775
 776/**
 777 * acpi_subsys_runtime_suspend - Suspend device using ACPI.
 778 * @dev: Device to suspend.
 779 *
 780 * Carry out the generic runtime suspend procedure for @dev and use ACPI to put
 781 * it into a runtime low-power state.
 782 */
 783int acpi_subsys_runtime_suspend(struct device *dev)
 784{
 785        int ret = pm_generic_runtime_suspend(dev);
 786        return ret ? ret : acpi_dev_runtime_suspend(dev);
 787}
 788EXPORT_SYMBOL_GPL(acpi_subsys_runtime_suspend);
 789
 790/**
 791 * acpi_subsys_runtime_resume - Resume device using ACPI.
 792 * @dev: Device to Resume.
 793 *
 794 * Use ACPI to put the given device into the full-power state and carry out the
 795 * generic runtime resume procedure for it.
 796 */
 797int acpi_subsys_runtime_resume(struct device *dev)
 798{
 799        int ret = acpi_dev_runtime_resume(dev);
 800        return ret ? ret : pm_generic_runtime_resume(dev);
 801}
 802EXPORT_SYMBOL_GPL(acpi_subsys_runtime_resume);
 803#endif /* CONFIG_PM_RUNTIME */
 804
 805#ifdef CONFIG_PM_SLEEP
 806/**
 807 * acpi_dev_suspend_late - Put device into a low-power state using ACPI.
 808 * @dev: Device to put into a low-power state.
 809 *
 810 * Put the given device into a low-power state during system transition to a
 811 * sleep state using the standard ACPI mechanism.  Set up system wakeup if
 812 * desired, choose the state to put the device into (this checks if system
 813 * wakeup is expected to work too), and set the power state of the device.
 814 */
 815int acpi_dev_suspend_late(struct device *dev)
 816{
 817        struct acpi_device *adev = acpi_dev_pm_get_node(dev);
 818        u32 target_state;
 819        bool wakeup;
 820        int error;
 821
 822        if (!adev)
 823                return 0;
 824
 825        target_state = acpi_target_system_state();
 826        wakeup = device_may_wakeup(dev);
 827        error = __acpi_device_sleep_wake(adev, target_state, wakeup);
 828        if (wakeup && error)
 829                return error;
 830
 831        error = acpi_dev_pm_low_power(dev, adev, target_state);
 832        if (error)
 833                __acpi_device_sleep_wake(adev, ACPI_STATE_UNKNOWN, false);
 834
 835        return error;
 836}
 837EXPORT_SYMBOL_GPL(acpi_dev_suspend_late);
 838
 839/**
 840 * acpi_dev_resume_early - Put device into the full-power state using ACPI.
 841 * @dev: Device to put into the full-power state.
 842 *
 843 * Put the given device into the full-power state using the standard ACPI
 844 * mechanism during system transition to the working state.  Set the power
 845 * state of the device to ACPI D0 and disable remote wakeup.
 846 */
 847int acpi_dev_resume_early(struct device *dev)
 848{
 849        struct acpi_device *adev = acpi_dev_pm_get_node(dev);
 850        int error;
 851
 852        if (!adev)
 853                return 0;
 854
 855        error = acpi_dev_pm_full_power(adev);
 856        __acpi_device_sleep_wake(adev, ACPI_STATE_UNKNOWN, false);
 857        return error;
 858}
 859EXPORT_SYMBOL_GPL(acpi_dev_resume_early);
 860
 861/**
 862 * acpi_subsys_prepare - Prepare device for system transition to a sleep state.
 863 * @dev: Device to prepare.
 864 */
 865int acpi_subsys_prepare(struct device *dev)
 866{
 867        /*
 868         * Follow PCI and resume devices suspended at run time before running
 869         * their system suspend callbacks.
 870         */
 871        pm_runtime_resume(dev);
 872        return pm_generic_prepare(dev);
 873}
 874EXPORT_SYMBOL_GPL(acpi_subsys_prepare);
 875
 876/**
 877 * acpi_subsys_suspend_late - Suspend device using ACPI.
 878 * @dev: Device to suspend.
 879 *
 880 * Carry out the generic late suspend procedure for @dev and use ACPI to put
 881 * it into a low-power state during system transition into a sleep state.
 882 */
 883int acpi_subsys_suspend_late(struct device *dev)
 884{
 885        int ret = pm_generic_suspend_late(dev);
 886        return ret ? ret : acpi_dev_suspend_late(dev);
 887}
 888EXPORT_SYMBOL_GPL(acpi_subsys_suspend_late);
 889
 890/**
 891 * acpi_subsys_resume_early - Resume device using ACPI.
 892 * @dev: Device to Resume.
 893 *
 894 * Use ACPI to put the given device into the full-power state and carry out the
 895 * generic early resume procedure for it during system transition into the
 896 * working state.
 897 */
 898int acpi_subsys_resume_early(struct device *dev)
 899{
 900        int ret = acpi_dev_resume_early(dev);
 901        return ret ? ret : pm_generic_resume_early(dev);
 902}
 903EXPORT_SYMBOL_GPL(acpi_subsys_resume_early);
 904#endif /* CONFIG_PM_SLEEP */
 905
 906static struct dev_pm_domain acpi_general_pm_domain = {
 907        .ops = {
 908#ifdef CONFIG_PM_RUNTIME
 909                .runtime_suspend = acpi_subsys_runtime_suspend,
 910                .runtime_resume = acpi_subsys_runtime_resume,
 911                .runtime_idle = pm_generic_runtime_idle,
 912#endif
 913#ifdef CONFIG_PM_SLEEP
 914                .prepare = acpi_subsys_prepare,
 915                .suspend_late = acpi_subsys_suspend_late,
 916                .resume_early = acpi_subsys_resume_early,
 917                .poweroff_late = acpi_subsys_suspend_late,
 918                .restore_early = acpi_subsys_resume_early,
 919#endif
 920        },
 921};
 922
 923/**
 924 * acpi_dev_pm_attach - Prepare device for ACPI power management.
 925 * @dev: Device to prepare.
 926 * @power_on: Whether or not to power on the device.
 927 *
 928 * If @dev has a valid ACPI handle that has a valid struct acpi_device object
 929 * attached to it, install a wakeup notification handler for the device and
 930 * add it to the general ACPI PM domain.  If @power_on is set, the device will
 931 * be put into the ACPI D0 state before the function returns.
 932 *
 933 * This assumes that the @dev's bus type uses generic power management callbacks
 934 * (or doesn't use any power management callbacks at all).
 935 *
 936 * Callers must ensure proper synchronization of this function with power
 937 * management callbacks.
 938 */
 939int acpi_dev_pm_attach(struct device *dev, bool power_on)
 940{
 941        struct acpi_device *adev = acpi_dev_pm_get_node(dev);
 942
 943        if (!adev)
 944                return -ENODEV;
 945
 946        if (dev->pm_domain)
 947                return -EEXIST;
 948
 949        acpi_add_pm_notifier(adev, acpi_wakeup_device, dev);
 950        dev->pm_domain = &acpi_general_pm_domain;
 951        if (power_on) {
 952                acpi_dev_pm_full_power(adev);
 953                __acpi_device_run_wake(adev, false);
 954        }
 955        return 0;
 956}
 957EXPORT_SYMBOL_GPL(acpi_dev_pm_attach);
 958
 959/**
 960 * acpi_dev_pm_detach - Remove ACPI power management from the device.
 961 * @dev: Device to take care of.
 962 * @power_off: Whether or not to try to remove power from the device.
 963 *
 964 * Remove the device from the general ACPI PM domain and remove its wakeup
 965 * notifier.  If @power_off is set, additionally remove power from the device if
 966 * possible.
 967 *
 968 * Callers must ensure proper synchronization of this function with power
 969 * management callbacks.
 970 */
 971void acpi_dev_pm_detach(struct device *dev, bool power_off)
 972{
 973        struct acpi_device *adev = acpi_dev_pm_get_node(dev);
 974
 975        if (adev && dev->pm_domain == &acpi_general_pm_domain) {
 976                dev->pm_domain = NULL;
 977                acpi_remove_pm_notifier(adev, acpi_wakeup_device);
 978                if (power_off) {
 979                        /*
 980                         * If the device's PM QoS resume latency limit or flags
 981                         * have been exposed to user space, they have to be
 982                         * hidden at this point, so that they don't affect the
 983                         * choice of the low-power state to put the device into.
 984                         */
 985                        dev_pm_qos_hide_latency_limit(dev);
 986                        dev_pm_qos_hide_flags(dev);
 987                        __acpi_device_run_wake(adev, false);
 988                        acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0);
 989                }
 990        }
 991}
 992EXPORT_SYMBOL_GPL(acpi_dev_pm_detach);
 993
 994/**
 995 * acpi_dev_pm_add_dependent - Add physical device depending for PM.
 996 * @handle: Handle of ACPI device node.
 997 * @depdev: Device depending on that node for PM.
 998 */
 999void acpi_dev_pm_add_dependent(acpi_handle handle, struct device *depdev)
1000{
1001        struct acpi_device_physical_node *dep;
1002        struct acpi_device *adev;
1003
1004        if (!depdev || acpi_bus_get_device(handle, &adev))
1005                return;
1006
1007        mutex_lock(&adev->physical_node_lock);
1008
1009        list_for_each_entry(dep, &adev->power_dependent, node)
1010                if (dep->dev == depdev)
1011                        goto out;
1012
1013        dep = kzalloc(sizeof(*dep), GFP_KERNEL);
1014        if (dep) {
1015                dep->dev = depdev;
1016                list_add_tail(&dep->node, &adev->power_dependent);
1017        }
1018
1019 out:
1020        mutex_unlock(&adev->physical_node_lock);
1021}
1022EXPORT_SYMBOL_GPL(acpi_dev_pm_add_dependent);
1023
1024/**
1025 * acpi_dev_pm_remove_dependent - Remove physical device depending for PM.
1026 * @handle: Handle of ACPI device node.
1027 * @depdev: Device depending on that node for PM.
1028 */
1029void acpi_dev_pm_remove_dependent(acpi_handle handle, struct device *depdev)
1030{
1031        struct acpi_device_physical_node *dep;
1032        struct acpi_device *adev;
1033
1034        if (!depdev || acpi_bus_get_device(handle, &adev))
1035                return;
1036
1037        mutex_lock(&adev->physical_node_lock);
1038
1039        list_for_each_entry(dep, &adev->power_dependent, node)
1040                if (dep->dev == depdev) {
1041                        list_del(&dep->node);
1042                        kfree(dep);
1043                        break;
1044                }
1045
1046        mutex_unlock(&adev->physical_node_lock);
1047}
1048EXPORT_SYMBOL_GPL(acpi_dev_pm_remove_dependent);
1049#endif /* CONFIG_PM */
1050
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