2 * drivers/acpi/device_pm.c - ACPI device power management routines.
4 * Copyright (C) 2012, Intel Corp.
5 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
7 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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.
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.
18 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
21 #include <linux/acpi.h>
22 #include <linux/export.h>
23 #include <linux/mutex.h>
24 #include <linux/pm_qos.h>
25 #include <linux/pm_domain.h>
26 #include <linux/pm_runtime.h>
27 #include <linux/suspend.h>
31 #define _COMPONENT ACPI_POWER_COMPONENT
32 ACPI_MODULE_NAME("device_pm");
35 * acpi_power_state_string - String representation of ACPI device power state.
36 * @state: ACPI device power state to return the string representation of.
38 const char *acpi_power_state_string(int state)
47 case ACPI_STATE_D3_HOT:
49 case ACPI_STATE_D3_COLD:
57 * acpi_device_get_power - Get power state of an ACPI device.
58 * @device: Device to get the power state of.
59 * @state: Place to store the power state of the device.
61 * This function does not update the device's power.state field, but it may
62 * update its parent's power.state field (when the parent's power state is
63 * unknown and the device's power state turns out to be D0).
65 int acpi_device_get_power(struct acpi_device *device, int *state)
67 int result = ACPI_STATE_UNKNOWN;
69 if (!device || !state)
72 if (!device->flags.power_manageable) {
73 /* TBD: Non-recursive algorithm for walking up hierarchy. */
74 *state = device->parent ?
75 device->parent->power.state : ACPI_STATE_D0;
80 * Get the device's power state from power resources settings and _PSC,
83 if (device->power.flags.power_resources) {
84 int error = acpi_power_get_inferred_state(device, &result);
88 if (device->power.flags.explicit_get) {
89 acpi_handle handle = device->handle;
90 unsigned long long psc;
93 status = acpi_evaluate_integer(handle, "_PSC", NULL, &psc);
94 if (ACPI_FAILURE(status))
98 * The power resources settings may indicate a power state
99 * shallower than the actual power state of the device, because
100 * the same power resources may be referenced by other devices.
102 * For systems predating ACPI 4.0 we assume that D3hot is the
103 * deepest state that can be supported.
105 if (psc > result && psc < ACPI_STATE_D3_COLD)
107 else if (result == ACPI_STATE_UNKNOWN)
108 result = psc > ACPI_STATE_D2 ? ACPI_STATE_D3_HOT : psc;
112 * If we were unsure about the device parent's power state up to this
113 * point, the fact that the device is in D0 implies that the parent has
114 * to be in D0 too, except if ignore_parent is set.
116 if (!device->power.flags.ignore_parent && device->parent
117 && device->parent->power.state == ACPI_STATE_UNKNOWN
118 && result == ACPI_STATE_D0)
119 device->parent->power.state = ACPI_STATE_D0;
124 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is %s\n",
125 device->pnp.bus_id, acpi_power_state_string(*state)));
130 static int acpi_dev_pm_explicit_set(struct acpi_device *adev, int state)
132 if (adev->power.states[state].flags.explicit_set) {
133 char method[5] = { '_', 'P', 'S', '0' + state, '\0' };
136 status = acpi_evaluate_object(adev->handle, method, NULL, NULL);
137 if (ACPI_FAILURE(status))
144 * acpi_device_set_power - Set power state of an ACPI device.
145 * @device: Device to set the power state of.
146 * @state: New power state to set.
148 * Callers must ensure that the device is power manageable before using this
151 int acpi_device_set_power(struct acpi_device *device, int state)
153 int target_state = state;
156 if (!device || !device->flags.power_manageable
157 || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
160 /* Make sure this is a valid target state */
162 if (state == device->power.state) {
163 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] already in %s\n",
165 acpi_power_state_string(state)));
169 if (state == ACPI_STATE_D3_COLD) {
171 * For transitions to D3cold we need to execute _PS3 and then
172 * possibly drop references to the power resources in use.
174 state = ACPI_STATE_D3_HOT;
175 /* If _PR3 is not available, use D3hot as the target state. */
176 if (!device->power.states[ACPI_STATE_D3_COLD].flags.valid)
177 target_state = state;
178 } else if (!device->power.states[state].flags.valid) {
179 dev_warn(&device->dev, "Power state %s not supported\n",
180 acpi_power_state_string(state));
184 if (!device->power.flags.ignore_parent &&
185 device->parent && (state < device->parent->power.state)) {
186 dev_warn(&device->dev,
187 "Cannot transition to power state %s for parent in %s\n",
188 acpi_power_state_string(state),
189 acpi_power_state_string(device->parent->power.state));
196 * In accordance with ACPI 6, _PSx is executed before manipulating power
197 * resources, unless the target state is D0, in which case _PS0 is
198 * supposed to be executed after turning the power resources on.
200 if (state > ACPI_STATE_D0) {
202 * According to ACPI 6, devices cannot go from lower-power
203 * (deeper) states to higher-power (shallower) states.
205 if (state < device->power.state) {
206 dev_warn(&device->dev, "Cannot transition from %s to %s\n",
207 acpi_power_state_string(device->power.state),
208 acpi_power_state_string(state));
212 result = acpi_dev_pm_explicit_set(device, state);
216 if (device->power.flags.power_resources)
217 result = acpi_power_transition(device, target_state);
219 if (device->power.flags.power_resources) {
220 result = acpi_power_transition(device, ACPI_STATE_D0);
224 result = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0);
229 dev_warn(&device->dev, "Failed to change power state to %s\n",
230 acpi_power_state_string(state));
232 device->power.state = target_state;
233 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
234 "Device [%s] transitioned to %s\n",
236 acpi_power_state_string(state)));
241 EXPORT_SYMBOL(acpi_device_set_power);
243 int acpi_bus_set_power(acpi_handle handle, int state)
245 struct acpi_device *device;
248 result = acpi_bus_get_device(handle, &device);
252 return acpi_device_set_power(device, state);
254 EXPORT_SYMBOL(acpi_bus_set_power);
256 int acpi_bus_init_power(struct acpi_device *device)
264 device->power.state = ACPI_STATE_UNKNOWN;
265 if (!acpi_device_is_present(device))
268 result = acpi_device_get_power(device, &state);
272 if (state < ACPI_STATE_D3_COLD && device->power.flags.power_resources) {
273 /* Reference count the power resources. */
274 result = acpi_power_on_resources(device, state);
278 if (state == ACPI_STATE_D0) {
280 * If _PSC is not present and the state inferred from
281 * power resources appears to be D0, it still may be
282 * necessary to execute _PS0 at this point, because
283 * another device using the same power resources may
284 * have been put into D0 previously and that's why we
287 result = acpi_dev_pm_explicit_set(device, state);
291 } else if (state == ACPI_STATE_UNKNOWN) {
293 * No power resources and missing _PSC? Cross fingers and make
294 * it D0 in hope that this is what the BIOS put the device into.
295 * [We tried to force D0 here by executing _PS0, but that broke
296 * Toshiba P870-303 in a nasty way.]
298 state = ACPI_STATE_D0;
300 device->power.state = state;
305 * acpi_device_fix_up_power - Force device with missing _PSC into D0.
306 * @device: Device object whose power state is to be fixed up.
308 * Devices without power resources and _PSC, but having _PS0 and _PS3 defined,
309 * are assumed to be put into D0 by the BIOS. However, in some cases that may
310 * not be the case and this function should be used then.
312 int acpi_device_fix_up_power(struct acpi_device *device)
316 if (!device->power.flags.power_resources
317 && !device->power.flags.explicit_get
318 && device->power.state == ACPI_STATE_D0)
319 ret = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0);
323 EXPORT_SYMBOL_GPL(acpi_device_fix_up_power);
325 int acpi_device_update_power(struct acpi_device *device, int *state_p)
330 if (device->power.state == ACPI_STATE_UNKNOWN) {
331 result = acpi_bus_init_power(device);
332 if (!result && state_p)
333 *state_p = device->power.state;
338 result = acpi_device_get_power(device, &state);
342 if (state == ACPI_STATE_UNKNOWN) {
343 state = ACPI_STATE_D0;
344 result = acpi_device_set_power(device, state);
348 if (device->power.flags.power_resources) {
350 * We don't need to really switch the state, bu we need
351 * to update the power resources' reference counters.
353 result = acpi_power_transition(device, state);
357 device->power.state = state;
364 EXPORT_SYMBOL_GPL(acpi_device_update_power);
366 int acpi_bus_update_power(acpi_handle handle, int *state_p)
368 struct acpi_device *device;
371 result = acpi_bus_get_device(handle, &device);
372 return result ? result : acpi_device_update_power(device, state_p);
374 EXPORT_SYMBOL_GPL(acpi_bus_update_power);
376 bool acpi_bus_power_manageable(acpi_handle handle)
378 struct acpi_device *device;
381 result = acpi_bus_get_device(handle, &device);
382 return result ? false : device->flags.power_manageable;
384 EXPORT_SYMBOL(acpi_bus_power_manageable);
387 static DEFINE_MUTEX(acpi_pm_notifier_lock);
389 void acpi_pm_wakeup_event(struct device *dev)
391 pm_wakeup_dev_event(dev, 0, acpi_s2idle_wakeup());
393 EXPORT_SYMBOL_GPL(acpi_pm_wakeup_event);
395 static void acpi_pm_notify_handler(acpi_handle handle, u32 val, void *not_used)
397 struct acpi_device *adev;
399 if (val != ACPI_NOTIFY_DEVICE_WAKE)
402 adev = acpi_bus_get_acpi_device(handle);
406 mutex_lock(&acpi_pm_notifier_lock);
408 if (adev->wakeup.flags.notifier_present) {
409 pm_wakeup_ws_event(adev->wakeup.ws, 0, acpi_s2idle_wakeup());
410 if (adev->wakeup.context.func)
411 adev->wakeup.context.func(&adev->wakeup.context);
414 mutex_unlock(&acpi_pm_notifier_lock);
416 acpi_bus_put_acpi_device(adev);
420 * acpi_add_pm_notifier - Register PM notify handler for given ACPI device.
421 * @adev: ACPI device to add the notify handler for.
422 * @dev: Device to generate a wakeup event for while handling the notification.
423 * @func: Work function to execute when handling the notification.
425 * NOTE: @adev need not be a run-wake or wakeup device to be a valid source of
426 * PM wakeup events. For example, wakeup events may be generated for bridges
427 * if one of the devices below the bridge is signaling wakeup, even if the
428 * bridge itself doesn't have a wakeup GPE associated with it.
430 acpi_status acpi_add_pm_notifier(struct acpi_device *adev, struct device *dev,
431 void (*func)(struct acpi_device_wakeup_context *context))
433 acpi_status status = AE_ALREADY_EXISTS;
436 return AE_BAD_PARAMETER;
438 mutex_lock(&acpi_pm_notifier_lock);
440 if (adev->wakeup.flags.notifier_present)
443 adev->wakeup.ws = wakeup_source_register(dev_name(&adev->dev));
444 adev->wakeup.context.dev = dev;
445 adev->wakeup.context.func = func;
447 status = acpi_install_notify_handler(adev->handle, ACPI_SYSTEM_NOTIFY,
448 acpi_pm_notify_handler, NULL);
449 if (ACPI_FAILURE(status))
452 adev->wakeup.flags.notifier_present = true;
455 mutex_unlock(&acpi_pm_notifier_lock);
460 * acpi_remove_pm_notifier - Unregister PM notifier from given ACPI device.
461 * @adev: ACPI device to remove the notifier from.
463 acpi_status acpi_remove_pm_notifier(struct acpi_device *adev)
465 acpi_status status = AE_BAD_PARAMETER;
467 mutex_lock(&acpi_pm_notifier_lock);
469 if (!adev->wakeup.flags.notifier_present)
472 status = acpi_remove_notify_handler(adev->handle,
474 acpi_pm_notify_handler);
475 if (ACPI_FAILURE(status))
478 adev->wakeup.context.func = NULL;
479 adev->wakeup.context.dev = NULL;
480 wakeup_source_unregister(adev->wakeup.ws);
482 adev->wakeup.flags.notifier_present = false;
485 mutex_unlock(&acpi_pm_notifier_lock);
489 bool acpi_bus_can_wakeup(acpi_handle handle)
491 struct acpi_device *device;
494 result = acpi_bus_get_device(handle, &device);
495 return result ? false : device->wakeup.flags.valid;
497 EXPORT_SYMBOL(acpi_bus_can_wakeup);
499 bool acpi_pm_device_can_wakeup(struct device *dev)
501 struct acpi_device *adev = ACPI_COMPANION(dev);
503 return adev ? acpi_device_can_wakeup(adev) : false;
507 * acpi_dev_pm_get_state - Get preferred power state of ACPI device.
508 * @dev: Device whose preferred target power state to return.
509 * @adev: ACPI device node corresponding to @dev.
510 * @target_state: System state to match the resultant device state.
511 * @d_min_p: Location to store the highest power state available to the device.
512 * @d_max_p: Location to store the lowest power state available to the device.
514 * Find the lowest power (highest number) and highest power (lowest number) ACPI
515 * device power states that the device can be in while the system is in the
516 * state represented by @target_state. Store the integer numbers representing
517 * those stats in the memory locations pointed to by @d_max_p and @d_min_p,
520 * Callers must ensure that @dev and @adev are valid pointers and that @adev
521 * actually corresponds to @dev before using this function.
523 * Returns 0 on success or -ENODATA when one of the ACPI methods fails or
524 * returns a value that doesn't make sense. The memory locations pointed to by
525 * @d_max_p and @d_min_p are only modified on success.
527 static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev,
528 u32 target_state, int *d_min_p, int *d_max_p)
530 char method[] = { '_', 'S', '0' + target_state, 'D', '\0' };
531 acpi_handle handle = adev->handle;
532 unsigned long long ret;
538 * If the system state is S0, the lowest power state the device can be
539 * in is D3cold, unless the device has _S0W and is supposed to signal
540 * wakeup, in which case the return value of _S0W has to be used as the
541 * lowest power state available to the device.
543 d_min = ACPI_STATE_D0;
544 d_max = ACPI_STATE_D3_COLD;
547 * If present, _SxD methods return the minimum D-state (highest power
548 * state) we can use for the corresponding S-states. Otherwise, the
549 * minimum D-state is D0 (ACPI 3.x).
551 if (target_state > ACPI_STATE_S0) {
553 * We rely on acpi_evaluate_integer() not clobbering the integer
554 * provided if AE_NOT_FOUND is returned.
557 status = acpi_evaluate_integer(handle, method, NULL, &ret);
558 if ((ACPI_FAILURE(status) && status != AE_NOT_FOUND)
559 || ret > ACPI_STATE_D3_COLD)
563 * We need to handle legacy systems where D3hot and D3cold are
564 * the same and 3 is returned in both cases, so fall back to
565 * D3cold if D3hot is not a valid state.
567 if (!adev->power.states[ret].flags.valid) {
568 if (ret == ACPI_STATE_D3_HOT)
569 ret = ACPI_STATE_D3_COLD;
574 wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
575 && adev->wakeup.sleep_state >= target_state;
576 } else if (dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) !=
578 wakeup = adev->wakeup.flags.valid;
582 * If _PRW says we can wake up the system from the target sleep state,
583 * the D-state returned by _SxD is sufficient for that (we assume a
584 * wakeup-aware driver if wake is set). Still, if _SxW exists
585 * (ACPI 3.x), it should return the maximum (lowest power) D-state that
586 * can wake the system. _S0W may be valid, too.
590 status = acpi_evaluate_integer(handle, method, NULL, &ret);
591 if (status == AE_NOT_FOUND) {
592 if (target_state > ACPI_STATE_S0)
594 } else if (ACPI_SUCCESS(status) && ret <= ACPI_STATE_D3_COLD) {
595 /* Fall back to D3cold if ret is not a valid state. */
596 if (!adev->power.states[ret].flags.valid)
597 ret = ACPI_STATE_D3_COLD;
599 d_max = ret > d_min ? ret : d_min;
615 * acpi_pm_device_sleep_state - Get preferred power state of ACPI device.
616 * @dev: Device whose preferred target power state to return.
617 * @d_min_p: Location to store the upper limit of the allowed states range.
618 * @d_max_in: Deepest low-power state to take into consideration.
619 * Return value: Preferred power state of the device on success, -ENODEV
620 * if there's no 'struct acpi_device' for @dev, -EINVAL if @d_max_in is
621 * incorrect, or -ENODATA on ACPI method failure.
623 * The caller must ensure that @dev is valid before using this function.
625 int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p, int d_max_in)
627 struct acpi_device *adev;
628 int ret, d_min, d_max;
630 if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3_COLD)
633 if (d_max_in > ACPI_STATE_D2) {
634 enum pm_qos_flags_status stat;
636 stat = dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF);
637 if (stat == PM_QOS_FLAGS_ALL)
638 d_max_in = ACPI_STATE_D2;
641 adev = ACPI_COMPANION(dev);
643 dev_dbg(dev, "ACPI companion missing in %s!\n", __func__);
647 ret = acpi_dev_pm_get_state(dev, adev, acpi_target_system_state(),
652 if (d_max_in < d_min)
655 if (d_max > d_max_in) {
656 for (d_max = d_max_in; d_max > d_min; d_max--) {
657 if (adev->power.states[d_max].flags.valid)
667 EXPORT_SYMBOL(acpi_pm_device_sleep_state);
670 * acpi_pm_notify_work_func - ACPI devices wakeup notification work function.
671 * @context: Device wakeup context.
673 static void acpi_pm_notify_work_func(struct acpi_device_wakeup_context *context)
675 struct device *dev = context->dev;
678 pm_wakeup_event(dev, 0);
679 pm_request_resume(dev);
684 * acpi_device_wakeup - Enable/disable wakeup functionality for device.
685 * @adev: ACPI device to enable/disable wakeup functionality for.
686 * @target_state: State the system is transitioning into.
687 * @enable: Whether to enable or disable the wakeup functionality.
689 * Enable/disable the GPE associated with @adev so that it can generate
690 * wakeup signals for the device in response to external (remote) events and
691 * enable/disable device wakeup power.
693 * Callers must ensure that @adev is a valid ACPI device node before executing
696 static int acpi_device_wakeup(struct acpi_device *adev, u32 target_state,
699 struct acpi_device_wakeup *wakeup = &adev->wakeup;
705 if (adev->wakeup.flags.enabled)
708 error = acpi_enable_wakeup_device_power(adev, target_state);
712 res = acpi_enable_gpe(wakeup->gpe_device, wakeup->gpe_number);
713 if (ACPI_FAILURE(res)) {
714 acpi_disable_wakeup_device_power(adev);
717 adev->wakeup.flags.enabled = 1;
718 } else if (adev->wakeup.flags.enabled) {
719 acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number);
720 acpi_disable_wakeup_device_power(adev);
721 adev->wakeup.flags.enabled = 0;
727 * acpi_pm_set_device_wakeup - Enable/disable remote wakeup for given device.
728 * @dev: Device to enable/disable to generate wakeup events.
729 * @enable: Whether to enable or disable the wakeup functionality.
731 int acpi_pm_set_device_wakeup(struct device *dev, bool enable)
733 struct acpi_device *adev;
736 adev = ACPI_COMPANION(dev);
738 dev_dbg(dev, "ACPI companion missing in %s!\n", __func__);
742 if (!acpi_device_can_wakeup(adev))
745 error = acpi_device_wakeup(adev, acpi_target_system_state(), enable);
747 dev_dbg(dev, "Wakeup %s by ACPI\n", enable ? "enabled" : "disabled");
751 EXPORT_SYMBOL(acpi_pm_set_device_wakeup);
754 * acpi_dev_pm_low_power - Put ACPI device into a low-power state.
755 * @dev: Device to put into a low-power state.
756 * @adev: ACPI device node corresponding to @dev.
757 * @system_state: System state to choose the device state for.
759 static int acpi_dev_pm_low_power(struct device *dev, struct acpi_device *adev,
764 if (!acpi_device_power_manageable(adev))
767 ret = acpi_dev_pm_get_state(dev, adev, system_state, NULL, &state);
768 return ret ? ret : acpi_device_set_power(adev, state);
772 * acpi_dev_pm_full_power - Put ACPI device into the full-power state.
773 * @adev: ACPI device node to put into the full-power state.
775 static int acpi_dev_pm_full_power(struct acpi_device *adev)
777 return acpi_device_power_manageable(adev) ?
778 acpi_device_set_power(adev, ACPI_STATE_D0) : 0;
782 * acpi_dev_runtime_suspend - Put device into a low-power state using ACPI.
783 * @dev: Device to put into a low-power state.
785 * Put the given device into a runtime low-power state using the standard ACPI
786 * mechanism. Set up remote wakeup if desired, choose the state to put the
787 * device into (this checks if remote wakeup is expected to work too), and set
788 * the power state of the device.
790 int acpi_dev_runtime_suspend(struct device *dev)
792 struct acpi_device *adev = ACPI_COMPANION(dev);
799 remote_wakeup = dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) >
801 error = acpi_device_wakeup(adev, ACPI_STATE_S0, remote_wakeup);
802 if (remote_wakeup && error)
805 error = acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0);
807 acpi_device_wakeup(adev, ACPI_STATE_S0, false);
811 EXPORT_SYMBOL_GPL(acpi_dev_runtime_suspend);
814 * acpi_dev_runtime_resume - Put device into the full-power state using ACPI.
815 * @dev: Device to put into the full-power state.
817 * Put the given device into the full-power state using the standard ACPI
818 * mechanism at run time. Set the power state of the device to ACPI D0 and
819 * disable remote wakeup.
821 int acpi_dev_runtime_resume(struct device *dev)
823 struct acpi_device *adev = ACPI_COMPANION(dev);
829 error = acpi_dev_pm_full_power(adev);
830 acpi_device_wakeup(adev, ACPI_STATE_S0, false);
833 EXPORT_SYMBOL_GPL(acpi_dev_runtime_resume);
836 * acpi_subsys_runtime_suspend - Suspend device using ACPI.
837 * @dev: Device to suspend.
839 * Carry out the generic runtime suspend procedure for @dev and use ACPI to put
840 * it into a runtime low-power state.
842 int acpi_subsys_runtime_suspend(struct device *dev)
844 int ret = pm_generic_runtime_suspend(dev);
845 return ret ? ret : acpi_dev_runtime_suspend(dev);
847 EXPORT_SYMBOL_GPL(acpi_subsys_runtime_suspend);
850 * acpi_subsys_runtime_resume - Resume device using ACPI.
851 * @dev: Device to Resume.
853 * Use ACPI to put the given device into the full-power state and carry out the
854 * generic runtime resume procedure for it.
856 int acpi_subsys_runtime_resume(struct device *dev)
858 int ret = acpi_dev_runtime_resume(dev);
859 return ret ? ret : pm_generic_runtime_resume(dev);
861 EXPORT_SYMBOL_GPL(acpi_subsys_runtime_resume);
863 #ifdef CONFIG_PM_SLEEP
865 * acpi_dev_suspend_late - Put device into a low-power state using ACPI.
866 * @dev: Device to put into a low-power state.
868 * Put the given device into a low-power state during system transition to a
869 * sleep state using the standard ACPI mechanism. Set up system wakeup if
870 * desired, choose the state to put the device into (this checks if system
871 * wakeup is expected to work too), and set the power state of the device.
873 int acpi_dev_suspend_late(struct device *dev)
875 struct acpi_device *adev = ACPI_COMPANION(dev);
883 target_state = acpi_target_system_state();
884 wakeup = device_may_wakeup(dev) && acpi_device_can_wakeup(adev);
885 error = acpi_device_wakeup(adev, target_state, wakeup);
889 error = acpi_dev_pm_low_power(dev, adev, target_state);
891 acpi_device_wakeup(adev, ACPI_STATE_UNKNOWN, false);
895 EXPORT_SYMBOL_GPL(acpi_dev_suspend_late);
898 * acpi_dev_resume_early - Put device into the full-power state using ACPI.
899 * @dev: Device to put into the full-power state.
901 * Put the given device into the full-power state using the standard ACPI
902 * mechanism during system transition to the working state. Set the power
903 * state of the device to ACPI D0 and disable remote wakeup.
905 int acpi_dev_resume_early(struct device *dev)
907 struct acpi_device *adev = ACPI_COMPANION(dev);
913 error = acpi_dev_pm_full_power(adev);
914 acpi_device_wakeup(adev, ACPI_STATE_UNKNOWN, false);
917 EXPORT_SYMBOL_GPL(acpi_dev_resume_early);
920 * acpi_subsys_prepare - Prepare device for system transition to a sleep state.
921 * @dev: Device to prepare.
923 int acpi_subsys_prepare(struct device *dev)
925 struct acpi_device *adev = ACPI_COMPANION(dev);
929 ret = pm_generic_prepare(dev);
933 if (!adev || !pm_runtime_suspended(dev)
934 || device_may_wakeup(dev) != !!adev->wakeup.prepare_count)
937 sys_target = acpi_target_system_state();
938 if (sys_target == ACPI_STATE_S0)
941 if (adev->power.flags.dsw_present)
944 ret = acpi_dev_pm_get_state(dev, adev, sys_target, NULL, &state);
945 return !ret && state == adev->power.state;
947 EXPORT_SYMBOL_GPL(acpi_subsys_prepare);
950 * acpi_subsys_suspend - Run the device driver's suspend callback.
951 * @dev: Device to handle.
953 * Follow PCI and resume devices suspended at run time before running their
954 * system suspend callbacks.
956 int acpi_subsys_suspend(struct device *dev)
958 pm_runtime_resume(dev);
959 return pm_generic_suspend(dev);
961 EXPORT_SYMBOL_GPL(acpi_subsys_suspend);
964 * acpi_subsys_suspend_late - Suspend device using ACPI.
965 * @dev: Device to suspend.
967 * Carry out the generic late suspend procedure for @dev and use ACPI to put
968 * it into a low-power state during system transition into a sleep state.
970 int acpi_subsys_suspend_late(struct device *dev)
972 int ret = pm_generic_suspend_late(dev);
973 return ret ? ret : acpi_dev_suspend_late(dev);
975 EXPORT_SYMBOL_GPL(acpi_subsys_suspend_late);
978 * acpi_subsys_resume_early - Resume device using ACPI.
979 * @dev: Device to Resume.
981 * Use ACPI to put the given device into the full-power state and carry out the
982 * generic early resume procedure for it during system transition into the
985 int acpi_subsys_resume_early(struct device *dev)
987 int ret = acpi_dev_resume_early(dev);
988 return ret ? ret : pm_generic_resume_early(dev);
990 EXPORT_SYMBOL_GPL(acpi_subsys_resume_early);
993 * acpi_subsys_freeze - Run the device driver's freeze callback.
994 * @dev: Device to handle.
996 int acpi_subsys_freeze(struct device *dev)
999 * This used to be done in acpi_subsys_prepare() for all devices and
1000 * some drivers may depend on it, so do it here. Ideally, however,
1001 * runtime-suspended devices should not be touched during freeze/thaw
1004 pm_runtime_resume(dev);
1005 return pm_generic_freeze(dev);
1007 EXPORT_SYMBOL_GPL(acpi_subsys_freeze);
1009 #endif /* CONFIG_PM_SLEEP */
1011 static struct dev_pm_domain acpi_general_pm_domain = {
1013 .runtime_suspend = acpi_subsys_runtime_suspend,
1014 .runtime_resume = acpi_subsys_runtime_resume,
1015 #ifdef CONFIG_PM_SLEEP
1016 .prepare = acpi_subsys_prepare,
1017 .complete = pm_complete_with_resume_check,
1018 .suspend = acpi_subsys_suspend,
1019 .suspend_late = acpi_subsys_suspend_late,
1020 .resume_early = acpi_subsys_resume_early,
1021 .freeze = acpi_subsys_freeze,
1022 .poweroff = acpi_subsys_suspend,
1023 .poweroff_late = acpi_subsys_suspend_late,
1024 .restore_early = acpi_subsys_resume_early,
1030 * acpi_dev_pm_detach - Remove ACPI power management from the device.
1031 * @dev: Device to take care of.
1032 * @power_off: Whether or not to try to remove power from the device.
1034 * Remove the device from the general ACPI PM domain and remove its wakeup
1035 * notifier. If @power_off is set, additionally remove power from the device if
1038 * Callers must ensure proper synchronization of this function with power
1039 * management callbacks.
1041 static void acpi_dev_pm_detach(struct device *dev, bool power_off)
1043 struct acpi_device *adev = ACPI_COMPANION(dev);
1045 if (adev && dev->pm_domain == &acpi_general_pm_domain) {
1046 dev_pm_domain_set(dev, NULL);
1047 acpi_remove_pm_notifier(adev);
1050 * If the device's PM QoS resume latency limit or flags
1051 * have been exposed to user space, they have to be
1052 * hidden at this point, so that they don't affect the
1053 * choice of the low-power state to put the device into.
1055 dev_pm_qos_hide_latency_limit(dev);
1056 dev_pm_qos_hide_flags(dev);
1057 acpi_device_wakeup(adev, ACPI_STATE_S0, false);
1058 acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0);
1064 * acpi_dev_pm_attach - Prepare device for ACPI power management.
1065 * @dev: Device to prepare.
1066 * @power_on: Whether or not to power on the device.
1068 * If @dev has a valid ACPI handle that has a valid struct acpi_device object
1069 * attached to it, install a wakeup notification handler for the device and
1070 * add it to the general ACPI PM domain. If @power_on is set, the device will
1071 * be put into the ACPI D0 state before the function returns.
1073 * This assumes that the @dev's bus type uses generic power management callbacks
1074 * (or doesn't use any power management callbacks at all).
1076 * Callers must ensure proper synchronization of this function with power
1077 * management callbacks.
1079 int acpi_dev_pm_attach(struct device *dev, bool power_on)
1081 struct acpi_device *adev = ACPI_COMPANION(dev);
1090 * Only attach the power domain to the first device if the
1091 * companion is shared by multiple. This is to prevent doing power
1094 if (!acpi_device_is_first_physical_node(adev, dev))
1097 acpi_add_pm_notifier(adev, dev, acpi_pm_notify_work_func);
1098 dev_pm_domain_set(dev, &acpi_general_pm_domain);
1100 acpi_dev_pm_full_power(adev);
1101 acpi_device_wakeup(adev, ACPI_STATE_S0, false);
1104 dev->pm_domain->detach = acpi_dev_pm_detach;
1107 EXPORT_SYMBOL_GPL(acpi_dev_pm_attach);
1108 #endif /* CONFIG_PM */