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