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 * 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.
22 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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>
31 #include <acpi/acpi.h>
32 #include <acpi/acpi_bus.h>
34 static DEFINE_MUTEX(acpi_pm_notifier_lock
);
37 * acpi_add_pm_notifier - Register PM notifier for given ACPI device.
38 * @adev: ACPI device to add the notifier for.
39 * @context: Context information to pass to the notifier routine.
41 * NOTE: @adev need not be a run-wake or wakeup device to be a valid source of
42 * PM wakeup events. For example, wakeup events may be generated for bridges
43 * if one of the devices below the bridge is signaling wakeup, even if the
44 * bridge itself doesn't have a wakeup GPE associated with it.
46 acpi_status
acpi_add_pm_notifier(struct acpi_device
*adev
,
47 acpi_notify_handler handler
, void *context
)
49 acpi_status status
= AE_ALREADY_EXISTS
;
51 mutex_lock(&acpi_pm_notifier_lock
);
53 if (adev
->wakeup
.flags
.notifier_present
)
56 status
= acpi_install_notify_handler(adev
->handle
,
59 if (ACPI_FAILURE(status
))
62 adev
->wakeup
.flags
.notifier_present
= true;
65 mutex_unlock(&acpi_pm_notifier_lock
);
70 * acpi_remove_pm_notifier - Unregister PM notifier from given ACPI device.
71 * @adev: ACPI device to remove the notifier from.
73 acpi_status
acpi_remove_pm_notifier(struct acpi_device
*adev
,
74 acpi_notify_handler handler
)
76 acpi_status status
= AE_BAD_PARAMETER
;
78 mutex_lock(&acpi_pm_notifier_lock
);
80 if (!adev
->wakeup
.flags
.notifier_present
)
83 status
= acpi_remove_notify_handler(adev
->handle
,
86 if (ACPI_FAILURE(status
))
89 adev
->wakeup
.flags
.notifier_present
= false;
92 mutex_unlock(&acpi_pm_notifier_lock
);
97 * acpi_device_power_state - Get preferred power state of ACPI device.
98 * @dev: Device whose preferred target power state to return.
99 * @adev: ACPI device node corresponding to @dev.
100 * @target_state: System state to match the resultant device state.
101 * @d_max_in: Deepest low-power state to take into consideration.
102 * @d_min_p: Location to store the upper limit of the allowed states range.
103 * Return value: Preferred power state of the device on success, -ENODEV
104 * (if there's no 'struct acpi_device' for @dev) or -EINVAL on failure
106 * Find the lowest power (highest number) ACPI device power state that the
107 * device can be in while the system is in the state represented by
108 * @target_state. If @d_min_p is set, the highest power (lowest number) device
109 * power state that @dev can be in for the given system sleep state is stored
110 * at the location pointed to by it.
112 * Callers must ensure that @dev and @adev are valid pointers and that @adev
113 * actually corresponds to @dev before using this function.
115 int acpi_device_power_state(struct device
*dev
, struct acpi_device
*adev
,
116 u32 target_state
, int d_max_in
, int *d_min_p
)
118 char acpi_method
[] = "_SxD";
119 unsigned long long d_min
, d_max
;
122 if (d_max_in
< ACPI_STATE_D0
|| d_max_in
> ACPI_STATE_D3
)
125 if (d_max_in
> ACPI_STATE_D3_HOT
) {
126 enum pm_qos_flags_status stat
;
128 stat
= dev_pm_qos_flags(dev
, PM_QOS_FLAG_NO_POWER_OFF
);
129 if (stat
== PM_QOS_FLAGS_ALL
)
130 d_max_in
= ACPI_STATE_D3_HOT
;
133 acpi_method
[2] = '0' + target_state
;
135 * If the sleep state is S0, the lowest limit from ACPI is D3,
136 * but if the device has _S0W, we will use the value from _S0W
137 * as the lowest limit from ACPI. Finally, we will constrain
138 * the lowest limit with the specified one.
140 d_min
= ACPI_STATE_D0
;
141 d_max
= ACPI_STATE_D3
;
144 * If present, _SxD methods return the minimum D-state (highest power
145 * state) we can use for the corresponding S-states. Otherwise, the
146 * minimum D-state is D0 (ACPI 3.x).
148 * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
149 * provided -- that's our fault recovery, we ignore retval.
151 if (target_state
> ACPI_STATE_S0
) {
152 acpi_evaluate_integer(adev
->handle
, acpi_method
, NULL
, &d_min
);
153 wakeup
= device_may_wakeup(dev
) && adev
->wakeup
.flags
.valid
154 && adev
->wakeup
.sleep_state
>= target_state
;
155 } else if (dev_pm_qos_flags(dev
, PM_QOS_FLAG_REMOTE_WAKEUP
) !=
157 wakeup
= adev
->wakeup
.flags
.valid
;
161 * If _PRW says we can wake up the system from the target sleep state,
162 * the D-state returned by _SxD is sufficient for that (we assume a
163 * wakeup-aware driver if wake is set). Still, if _SxW exists
164 * (ACPI 3.x), it should return the maximum (lowest power) D-state that
165 * can wake the system. _S0W may be valid, too.
170 acpi_method
[3] = 'W';
171 status
= acpi_evaluate_integer(adev
->handle
, acpi_method
, NULL
,
173 if (ACPI_FAILURE(status
)) {
174 if (target_state
!= ACPI_STATE_S0
||
175 status
!= AE_NOT_FOUND
)
177 } else if (d_max
< d_min
) {
178 /* Warn the user of the broken DSDT */
179 printk(KERN_WARNING
"ACPI: Wrong value from %s\n",
186 if (d_max_in
< d_min
)
190 /* constrain d_max with specified lowest limit (max number) */
191 if (d_max
> d_max_in
) {
192 for (d_max
= d_max_in
; d_max
> d_min
; d_max
--) {
193 if (adev
->power
.states
[d_max
].flags
.valid
)
199 EXPORT_SYMBOL_GPL(acpi_device_power_state
);
202 * acpi_pm_device_sleep_state - Get preferred power state of ACPI device.
203 * @dev: Device whose preferred target power state to return.
204 * @d_min_p: Location to store the upper limit of the allowed states range.
205 * @d_max_in: Deepest low-power state to take into consideration.
206 * Return value: Preferred power state of the device on success, -ENODEV
207 * (if there's no 'struct acpi_device' for @dev) or -EINVAL on failure
209 * The caller must ensure that @dev is valid before using this function.
211 int acpi_pm_device_sleep_state(struct device
*dev
, int *d_min_p
, int d_max_in
)
213 acpi_handle handle
= DEVICE_ACPI_HANDLE(dev
);
214 struct acpi_device
*adev
;
216 if (!handle
|| ACPI_FAILURE(acpi_bus_get_device(handle
, &adev
))) {
217 dev_dbg(dev
, "ACPI handle without context in %s!\n", __func__
);
221 return acpi_device_power_state(dev
, adev
, acpi_target_system_state(),
224 EXPORT_SYMBOL(acpi_pm_device_sleep_state
);
226 #ifdef CONFIG_PM_RUNTIME
228 * acpi_wakeup_device - Wakeup notification handler for ACPI devices.
229 * @handle: ACPI handle of the device the notification is for.
230 * @event: Type of the signaled event.
231 * @context: Device corresponding to @handle.
233 static void acpi_wakeup_device(acpi_handle handle
, u32 event
, void *context
)
235 struct device
*dev
= context
;
237 if (event
== ACPI_NOTIFY_DEVICE_WAKE
&& dev
) {
238 pm_wakeup_event(dev
, 0);
239 pm_runtime_resume(dev
);
244 * __acpi_device_run_wake - Enable/disable runtime remote wakeup for device.
245 * @adev: ACPI device to enable/disable the remote wakeup for.
246 * @enable: Whether to enable or disable the wakeup functionality.
248 * Enable/disable the GPE associated with @adev so that it can generate
249 * wakeup signals for the device in response to external (remote) events and
250 * enable/disable device wakeup power.
252 * Callers must ensure that @adev is a valid ACPI device node before executing
255 int __acpi_device_run_wake(struct acpi_device
*adev
, bool enable
)
257 struct acpi_device_wakeup
*wakeup
= &adev
->wakeup
;
263 error
= acpi_enable_wakeup_device_power(adev
, ACPI_STATE_S0
);
267 res
= acpi_enable_gpe(wakeup
->gpe_device
, wakeup
->gpe_number
);
268 if (ACPI_FAILURE(res
)) {
269 acpi_disable_wakeup_device_power(adev
);
273 acpi_disable_gpe(wakeup
->gpe_device
, wakeup
->gpe_number
);
274 acpi_disable_wakeup_device_power(adev
);
280 * acpi_pm_device_run_wake - Enable/disable remote wakeup for given device.
281 * @dev: Device to enable/disable the platform to wake up.
282 * @enable: Whether to enable or disable the wakeup functionality.
284 int acpi_pm_device_run_wake(struct device
*phys_dev
, bool enable
)
286 struct acpi_device
*adev
;
289 if (!device_run_wake(phys_dev
))
292 handle
= DEVICE_ACPI_HANDLE(phys_dev
);
293 if (!handle
|| ACPI_FAILURE(acpi_bus_get_device(handle
, &adev
))) {
294 dev_dbg(phys_dev
, "ACPI handle without context in %s!\n",
299 return __acpi_device_run_wake(adev
, enable
);
301 EXPORT_SYMBOL(acpi_pm_device_run_wake
);
303 static inline void acpi_wakeup_device(acpi_handle handle
, u32 event
,
305 #endif /* CONFIG_PM_RUNTIME */
307 #ifdef CONFIG_PM_SLEEP
309 * __acpi_device_sleep_wake - Enable or disable device to wake up the system.
310 * @dev: Device to enable/desible to wake up the system.
311 * @target_state: System state the device is supposed to wake up from.
312 * @enable: Whether to enable or disable @dev to wake up the system.
314 int __acpi_device_sleep_wake(struct acpi_device
*adev
, u32 target_state
,
318 acpi_enable_wakeup_device_power(adev
, target_state
) :
319 acpi_disable_wakeup_device_power(adev
);
323 * acpi_pm_device_sleep_wake - Enable or disable device to wake up the system.
324 * @dev: Device to enable/desible to wake up the system from sleep states.
325 * @enable: Whether to enable or disable @dev to wake up the system.
327 int acpi_pm_device_sleep_wake(struct device
*dev
, bool enable
)
330 struct acpi_device
*adev
;
333 if (!device_can_wakeup(dev
))
336 handle
= DEVICE_ACPI_HANDLE(dev
);
337 if (!handle
|| ACPI_FAILURE(acpi_bus_get_device(handle
, &adev
))) {
338 dev_dbg(dev
, "ACPI handle without context in %s!\n", __func__
);
342 error
= __acpi_device_sleep_wake(adev
, acpi_target_system_state(),
345 dev_info(dev
, "System wakeup %s by ACPI\n",
346 enable
? "enabled" : "disabled");
350 #endif /* CONFIG_PM_SLEEP */
353 * acpi_dev_pm_get_node - Get ACPI device node for the given physical device.
354 * @dev: Device to get the ACPI node for.
356 static struct acpi_device
*acpi_dev_pm_get_node(struct device
*dev
)
358 acpi_handle handle
= DEVICE_ACPI_HANDLE(dev
);
359 struct acpi_device
*adev
;
361 return handle
&& !acpi_bus_get_device(handle
, &adev
) ? adev
: NULL
;
365 * acpi_dev_pm_low_power - Put ACPI device into a low-power state.
366 * @dev: Device to put into a low-power state.
367 * @adev: ACPI device node corresponding to @dev.
368 * @system_state: System state to choose the device state for.
370 static int acpi_dev_pm_low_power(struct device
*dev
, struct acpi_device
*adev
,
375 if (!acpi_device_power_manageable(adev
))
378 power_state
= acpi_device_power_state(dev
, adev
, system_state
,
379 ACPI_STATE_D3
, NULL
);
380 if (power_state
< ACPI_STATE_D0
|| power_state
> ACPI_STATE_D3
)
383 return acpi_device_set_power(adev
, power_state
);
387 * acpi_dev_pm_full_power - Put ACPI device into the full-power state.
388 * @adev: ACPI device node to put into the full-power state.
390 static int acpi_dev_pm_full_power(struct acpi_device
*adev
)
392 return acpi_device_power_manageable(adev
) ?
393 acpi_device_set_power(adev
, ACPI_STATE_D0
) : 0;
396 #ifdef CONFIG_PM_RUNTIME
398 * acpi_dev_runtime_suspend - Put device into a low-power state using ACPI.
399 * @dev: Device to put into a low-power state.
401 * Put the given device into a runtime low-power state using the standard ACPI
402 * mechanism. Set up remote wakeup if desired, choose the state to put the
403 * device into (this checks if remote wakeup is expected to work too), and set
404 * the power state of the device.
406 int acpi_dev_runtime_suspend(struct device
*dev
)
408 struct acpi_device
*adev
= acpi_dev_pm_get_node(dev
);
415 remote_wakeup
= dev_pm_qos_flags(dev
, PM_QOS_FLAG_REMOTE_WAKEUP
) >
417 error
= __acpi_device_run_wake(adev
, remote_wakeup
);
418 if (remote_wakeup
&& error
)
421 error
= acpi_dev_pm_low_power(dev
, adev
, ACPI_STATE_S0
);
423 __acpi_device_run_wake(adev
, false);
427 EXPORT_SYMBOL_GPL(acpi_dev_runtime_suspend
);
430 * acpi_dev_runtime_resume - Put device into the full-power state using ACPI.
431 * @dev: Device to put into the full-power state.
433 * Put the given device into the full-power state using the standard ACPI
434 * mechanism at run time. Set the power state of the device to ACPI D0 and
435 * disable remote wakeup.
437 int acpi_dev_runtime_resume(struct device
*dev
)
439 struct acpi_device
*adev
= acpi_dev_pm_get_node(dev
);
445 error
= acpi_dev_pm_full_power(adev
);
446 __acpi_device_run_wake(adev
, false);
449 EXPORT_SYMBOL_GPL(acpi_dev_runtime_resume
);
452 * acpi_subsys_runtime_suspend - Suspend device using ACPI.
453 * @dev: Device to suspend.
455 * Carry out the generic runtime suspend procedure for @dev and use ACPI to put
456 * it into a runtime low-power state.
458 int acpi_subsys_runtime_suspend(struct device
*dev
)
460 int ret
= pm_generic_runtime_suspend(dev
);
461 return ret
? ret
: acpi_dev_runtime_suspend(dev
);
463 EXPORT_SYMBOL_GPL(acpi_subsys_runtime_suspend
);
466 * acpi_subsys_runtime_resume - Resume device using ACPI.
467 * @dev: Device to Resume.
469 * Use ACPI to put the given device into the full-power state and carry out the
470 * generic runtime resume procedure for it.
472 int acpi_subsys_runtime_resume(struct device
*dev
)
474 int ret
= acpi_dev_runtime_resume(dev
);
475 return ret
? ret
: pm_generic_runtime_resume(dev
);
477 EXPORT_SYMBOL_GPL(acpi_subsys_runtime_resume
);
478 #endif /* CONFIG_PM_RUNTIME */
480 #ifdef CONFIG_PM_SLEEP
482 * acpi_dev_suspend_late - Put device into a low-power state using ACPI.
483 * @dev: Device to put into a low-power state.
485 * Put the given device into a low-power state during system transition to a
486 * sleep state using the standard ACPI mechanism. Set up system wakeup if
487 * desired, choose the state to put the device into (this checks if system
488 * wakeup is expected to work too), and set the power state of the device.
490 int acpi_dev_suspend_late(struct device
*dev
)
492 struct acpi_device
*adev
= acpi_dev_pm_get_node(dev
);
500 target_state
= acpi_target_system_state();
501 wakeup
= device_may_wakeup(dev
);
502 error
= __acpi_device_sleep_wake(adev
, target_state
, wakeup
);
506 error
= acpi_dev_pm_low_power(dev
, adev
, target_state
);
508 __acpi_device_sleep_wake(adev
, ACPI_STATE_UNKNOWN
, false);
512 EXPORT_SYMBOL_GPL(acpi_dev_suspend_late
);
515 * acpi_dev_resume_early - Put device into the full-power state using ACPI.
516 * @dev: Device to put into the full-power state.
518 * Put the given device into the full-power state using the standard ACPI
519 * mechanism during system transition to the working state. Set the power
520 * state of the device to ACPI D0 and disable remote wakeup.
522 int acpi_dev_resume_early(struct device
*dev
)
524 struct acpi_device
*adev
= acpi_dev_pm_get_node(dev
);
530 error
= acpi_dev_pm_full_power(adev
);
531 __acpi_device_sleep_wake(adev
, ACPI_STATE_UNKNOWN
, false);
534 EXPORT_SYMBOL_GPL(acpi_dev_resume_early
);
537 * acpi_subsys_prepare - Prepare device for system transition to a sleep state.
538 * @dev: Device to prepare.
540 int acpi_subsys_prepare(struct device
*dev
)
543 * Follow PCI and resume devices suspended at run time before running
544 * their system suspend callbacks.
546 pm_runtime_resume(dev
);
547 return pm_generic_prepare(dev
);
549 EXPORT_SYMBOL_GPL(acpi_subsys_prepare
);
552 * acpi_subsys_suspend_late - Suspend device using ACPI.
553 * @dev: Device to suspend.
555 * Carry out the generic late suspend procedure for @dev and use ACPI to put
556 * it into a low-power state during system transition into a sleep state.
558 int acpi_subsys_suspend_late(struct device
*dev
)
560 int ret
= pm_generic_suspend_late(dev
);
561 return ret
? ret
: acpi_dev_suspend_late(dev
);
563 EXPORT_SYMBOL_GPL(acpi_subsys_suspend_late
);
566 * acpi_subsys_resume_early - Resume device using ACPI.
567 * @dev: Device to Resume.
569 * Use ACPI to put the given device into the full-power state and carry out the
570 * generic early resume procedure for it during system transition into the
573 int acpi_subsys_resume_early(struct device
*dev
)
575 int ret
= acpi_dev_resume_early(dev
);
576 return ret
? ret
: pm_generic_resume_early(dev
);
578 EXPORT_SYMBOL_GPL(acpi_subsys_resume_early
);
579 #endif /* CONFIG_PM_SLEEP */
581 static struct dev_pm_domain acpi_general_pm_domain
= {
583 #ifdef CONFIG_PM_RUNTIME
584 .runtime_suspend
= acpi_subsys_runtime_suspend
,
585 .runtime_resume
= acpi_subsys_runtime_resume
,
586 .runtime_idle
= pm_generic_runtime_idle
,
588 #ifdef CONFIG_PM_SLEEP
589 .prepare
= acpi_subsys_prepare
,
590 .suspend_late
= acpi_subsys_suspend_late
,
591 .resume_early
= acpi_subsys_resume_early
,
592 .poweroff_late
= acpi_subsys_suspend_late
,
593 .restore_early
= acpi_subsys_resume_early
,
599 * acpi_dev_pm_attach - Prepare device for ACPI power management.
600 * @dev: Device to prepare.
601 * @power_on: Whether or not to power on the device.
603 * If @dev has a valid ACPI handle that has a valid struct acpi_device object
604 * attached to it, install a wakeup notification handler for the device and
605 * add it to the general ACPI PM domain. If @power_on is set, the device will
606 * be put into the ACPI D0 state before the function returns.
608 * This assumes that the @dev's bus type uses generic power management callbacks
609 * (or doesn't use any power management callbacks at all).
611 * Callers must ensure proper synchronization of this function with power
612 * management callbacks.
614 int acpi_dev_pm_attach(struct device
*dev
, bool power_on
)
616 struct acpi_device
*adev
= acpi_dev_pm_get_node(dev
);
624 acpi_add_pm_notifier(adev
, acpi_wakeup_device
, dev
);
625 dev
->pm_domain
= &acpi_general_pm_domain
;
627 acpi_dev_pm_full_power(adev
);
628 __acpi_device_run_wake(adev
, false);
632 EXPORT_SYMBOL_GPL(acpi_dev_pm_attach
);
635 * acpi_dev_pm_detach - Remove ACPI power management from the device.
636 * @dev: Device to take care of.
637 * @power_off: Whether or not to try to remove power from the device.
639 * Remove the device from the general ACPI PM domain and remove its wakeup
640 * notifier. If @power_off is set, additionally remove power from the device if
643 * Callers must ensure proper synchronization of this function with power
644 * management callbacks.
646 void acpi_dev_pm_detach(struct device
*dev
, bool power_off
)
648 struct acpi_device
*adev
= acpi_dev_pm_get_node(dev
);
650 if (adev
&& dev
->pm_domain
== &acpi_general_pm_domain
) {
651 dev
->pm_domain
= NULL
;
652 acpi_remove_pm_notifier(adev
, acpi_wakeup_device
);
655 * If the device's PM QoS resume latency limit or flags
656 * have been exposed to user space, they have to be
657 * hidden at this point, so that they don't affect the
658 * choice of the low-power state to put the device into.
660 dev_pm_qos_hide_latency_limit(dev
);
661 dev_pm_qos_hide_flags(dev
);
662 __acpi_device_run_wake(adev
, false);
663 acpi_dev_pm_low_power(dev
, adev
, ACPI_STATE_S0
);
667 EXPORT_SYMBOL_GPL(acpi_dev_pm_detach
);