1 // SPDX-License-Identifier: GPL-2.0-only
3  * drivers/acpi/device_pm.c - ACPI device power management routines.
28  * acpi_power_state_string - String representation of ACPI device power state.
29  * @state: ACPI device power state to return the string representation of.
54 	status = acpi_evaluate_integer(device->handle, "_PSC", NULL, &psc);  in acpi_dev_pm_explicit_get()
56 		return -ENODEV;  in acpi_dev_pm_explicit_get()
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.
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).
71  * Also, it does not update power resource reference counters to ensure that
72  * the power state returned by it will be persistent and it may return a power
74  * (if that power state depends on any power resources).
82 		return -EINVAL;  in acpi_device_get_power()
84 	if (!device->flags.power_manageable) {  in acpi_device_get_power()
85 		/* TBD: Non-recursive algorithm for walking up hierarchy. */  in acpi_device_get_power()
86 		*state = device->parent ?  in acpi_device_get_power()
87 			device->parent->power.state : ACPI_STATE_D0;  in acpi_device_get_power()
92 	 * Get the device's power state from power resources settings and _PSC,  in acpi_device_get_power()
95 	if (device->power.flags.power_resources) {  in acpi_device_get_power()
100 	if (device->power.flags.explicit_get) {  in acpi_device_get_power()
108 		 * The power resources settings may indicate a power state  in acpi_device_get_power()
109 		 * shallower than the actual power state of the device, because  in acpi_device_get_power()
110 		 * the same power resources may be referenced by other devices.  in acpi_device_get_power()
122 	 * If we were unsure about the device parent's power state up to this  in acpi_device_get_power()
126 	if (!device->power.flags.ignore_parent && device->parent  in acpi_device_get_power()
127 	    && device->parent->power.state == ACPI_STATE_UNKNOWN  in acpi_device_get_power()
129 		device->parent->power.state = ACPI_STATE_D0;  in acpi_device_get_power()
134 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is %s\n",  in acpi_device_get_power()
135 			  device->pnp.bus_id, acpi_power_state_string(*state)));  in acpi_device_get_power()
142 	if (adev->power.states[state].flags.explicit_set) {  in acpi_dev_pm_explicit_set()
146 		status = acpi_evaluate_object(adev->handle, method, NULL, NULL);  in acpi_dev_pm_explicit_set()
148 			return -ENODEV;  in acpi_dev_pm_explicit_set()
154  * acpi_device_set_power - Set power state of an ACPI device.
155  * @device: Device to set the power state of.
156  * @state: New power state to set.
158  * Callers must ensure that the device is power manageable before using this
166 	if (!device || !device->flags.power_manageable  in acpi_device_set_power()
168 		return -EINVAL;  in acpi_device_set_power()
170 	acpi_handle_debug(device->handle, "Power state change: %s -> %s\n",  in acpi_device_set_power()
171 			  acpi_power_state_string(device->power.state),  in acpi_device_set_power()
177 	if (state > ACPI_STATE_D0 && state == device->power.state) {  in acpi_device_set_power()
179 				  device->pnp.bus_id,  in acpi_device_set_power()
187 		 * possibly drop references to the power resources in use.  in acpi_device_set_power()
191 		if (!device->power.states[ACPI_STATE_D3_COLD].flags.valid)  in acpi_device_set_power()
193 	} else if (!device->power.states[state].flags.valid) {  in acpi_device_set_power()
194 		dev_warn(&device->dev, "Power state %s not supported\n",  in acpi_device_set_power()
196 		return -ENODEV;  in acpi_device_set_power()
199 	if (!device->power.flags.ignore_parent &&  in acpi_device_set_power()
200 	    device->parent && (state < device->parent->power.state)) {  in acpi_device_set_power()
201 		dev_warn(&device->dev,  in acpi_device_set_power()
202 			 "Cannot transition to power state %s for parent in %s\n",  in acpi_device_set_power()
204 			 acpi_power_state_string(device->parent->power.state));  in acpi_device_set_power()
205 		return -ENODEV;  in acpi_device_set_power()
209 	 * Transition Power  in acpi_device_set_power()
210 	 * ----------------  in acpi_device_set_power()
211 	 * In accordance with ACPI 6, _PSx is executed before manipulating power  in acpi_device_set_power()
213 	 * supposed to be executed after turning the power resources on.  in acpi_device_set_power()
217 		 * According to ACPI 6, devices cannot go from lower-power  in acpi_device_set_power()
218 		 * (deeper) states to higher-power (shallower) states.  in acpi_device_set_power()
220 		if (state < device->power.state) {  in acpi_device_set_power()
221 			dev_warn(&device->dev, "Cannot transition from %s to %s\n",  in acpi_device_set_power()
222 				 acpi_power_state_string(device->power.state),  in acpi_device_set_power()
224 			return -ENODEV;  in acpi_device_set_power()
231 		if (device->power.state < ACPI_STATE_D3_HOT) {  in acpi_device_set_power()
237 		if (device->power.flags.power_resources)  in acpi_device_set_power()
240 		int cur_state = device->power.state;  in acpi_device_set_power()
242 		if (device->power.flags.power_resources) {  in acpi_device_set_power()
252 			if (!device->power.flags.explicit_get)  in acpi_device_set_power()
256 			 * The power state of the device was set to D0 last  in acpi_device_set_power()
258 			 * system-wide transition involving the platform  in acpi_device_set_power()
261 			 * and evaluate _PSC to check the device's current power  in acpi_device_set_power()
263 			 * is successful and it returns a power state different  in acpi_device_set_power()
276 		dev_warn(&device->dev, "Failed to change power state to %s\n",  in acpi_device_set_power()
279 		device->power.state = target_state;  in acpi_device_set_power()
282 				  device->pnp.bus_id,  in acpi_device_set_power()
309 		return -EINVAL;  in acpi_bus_init_power()
311 	device->power.state = ACPI_STATE_UNKNOWN;  in acpi_bus_init_power()
313 		device->flags.initialized = false;  in acpi_bus_init_power()
314 		return -ENXIO;  in acpi_bus_init_power()
321 	if (state < ACPI_STATE_D3_COLD && device->power.flags.power_resources) {  in acpi_bus_init_power()
322 		/* Reference count the power resources. */  in acpi_bus_init_power()
330 			 * power resources appears to be D0, it still may be  in acpi_bus_init_power()
332 			 * another device using the same power resources may  in acpi_bus_init_power()
342 		 * No power resources and missing _PSC?  Cross fingers and make  in acpi_bus_init_power()
345 		 * Toshiba P870-303 in a nasty way.]  in acpi_bus_init_power()
349 	device->power.state = state;  in acpi_bus_init_power()
354  * acpi_device_fix_up_power - Force device with missing _PSC into D0.
355  * @device: Device object whose power state is to be fixed up.
357  * Devices without power resources and _PSC, but having _PS0 and _PS3 defined,
365 	if (!device->power.flags.power_resources  in acpi_device_fix_up_power()
366 	    && !device->power.flags.explicit_get  in acpi_device_fix_up_power()
367 	    && device->power.state == ACPI_STATE_D0)  in acpi_device_fix_up_power()
379 	if (device->power.state == ACPI_STATE_UNKNOWN) {  in acpi_device_update_power()
382 			*state_p = device->power.state;  in acpi_device_update_power()
397 		if (device->power.flags.power_resources) {  in acpi_device_update_power()
400 			 * to update the power resources' reference counters.  in acpi_device_update_power()
406 		device->power.state = state;  in acpi_device_update_power()
431 	return result ? false : device->flags.power_manageable;  in acpi_bus_power_manageable()
460 	if (adev->wakeup.flags.notifier_present) {  in acpi_pm_notify_handler()
461 		pm_wakeup_ws_event(adev->wakeup.ws, 0, acpi_s2idle_wakeup());  in acpi_pm_notify_handler()
462 		if (adev->wakeup.context.func) {  in acpi_pm_notify_handler()
464 					  adev->wakeup.context.func,  in acpi_pm_notify_handler()
465 					  dev_name(adev->wakeup.context.dev));  in acpi_pm_notify_handler()
466 			adev->wakeup.context.func(&adev->wakeup.context);  in acpi_pm_notify_handler()
476  * acpi_add_pm_notifier - Register PM notify handler for given ACPI device.
481  * NOTE: @adev need not be a run-wake or wakeup device to be a valid source of
496 	if (adev->wakeup.flags.notifier_present)  in acpi_add_pm_notifier()
499 	status = acpi_install_notify_handler(adev->handle, ACPI_SYSTEM_NOTIFY,  in acpi_add_pm_notifier()
505 	adev->wakeup.ws = wakeup_source_register(&adev->dev,  in acpi_add_pm_notifier()
506 						 dev_name(&adev->dev));  in acpi_add_pm_notifier()
507 	adev->wakeup.context.dev = dev;  in acpi_add_pm_notifier()
508 	adev->wakeup.context.func = func;  in acpi_add_pm_notifier()
509 	adev->wakeup.flags.notifier_present = true;  in acpi_add_pm_notifier()
518  * acpi_remove_pm_notifier - Unregister PM notifier from given ACPI device.
527 	if (!adev->wakeup.flags.notifier_present)  in acpi_remove_pm_notifier()
530 	status = acpi_remove_notify_handler(adev->handle,  in acpi_remove_pm_notifier()
537 	adev->wakeup.context.func = NULL;  in acpi_remove_pm_notifier()
538 	adev->wakeup.context.dev = NULL;  in acpi_remove_pm_notifier()
539 	wakeup_source_unregister(adev->wakeup.ws);  in acpi_remove_pm_notifier()
540 	adev->wakeup.flags.notifier_present = false;  in acpi_remove_pm_notifier()
554 	return result ? false : device->wakeup.flags.valid;  in acpi_bus_can_wakeup()
566  * acpi_dev_pm_get_state - Get preferred power state of ACPI device.
567  * @dev: Device whose preferred target power state to return.
570  * @d_min_p: Location to store the highest power state available to the device.
571  * @d_max_p: Location to store the lowest power state available to the device.
573  * Find the lowest power (highest number) and highest power (lowest number) ACPI
574  * device power states that the device can be in while the system is in the
582  * Returns 0 on success or -ENODATA when one of the ACPI methods fails or
590 	acpi_handle handle = adev->handle;  in acpi_dev_pm_get_state()
598 	 * If the system state is S0, the lowest power state the device can be  in acpi_dev_pm_get_state()
601 	 * lowest power state available to the device.  in acpi_dev_pm_get_state()
607 	 * If present, _SxD methods return the minimum D-state (highest power  in acpi_dev_pm_get_state()
608 	 * state) we can use for the corresponding S-states.  Otherwise, the  in acpi_dev_pm_get_state()
609 	 * minimum D-state is D0 (ACPI 3.x).  in acpi_dev_pm_get_state()
620 			return -ENODATA;  in acpi_dev_pm_get_state()
627 		if (!adev->power.states[ret].flags.valid) {  in acpi_dev_pm_get_state()
631 				return -ENODATA;  in acpi_dev_pm_get_state()
638 		wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid  in acpi_dev_pm_get_state()
639 			&& adev->wakeup.sleep_state >= target_state;  in acpi_dev_pm_get_state()
641 		wakeup = adev->wakeup.flags.valid;  in acpi_dev_pm_get_state()
646 	 * the D-state returned by _SxD is sufficient for that (we assume a  in acpi_dev_pm_get_state()
647 	 * wakeup-aware driver if wake is set).  Still, if _SxW exists  in acpi_dev_pm_get_state()
648 	 * (ACPI 3.x), it should return the maximum (lowest power) D-state that  in acpi_dev_pm_get_state()
656 			 * must not go into any power state deeper than the  in acpi_dev_pm_get_state()
663 			if (!adev->power.states[ret].flags.valid)  in acpi_dev_pm_get_state()
668 			return -ENODATA;  in acpi_dev_pm_get_state()
682  * acpi_pm_device_sleep_state - Get preferred power state of ACPI device.
683  * @dev: Device whose preferred target power state to return.
685  * @d_max_in: Deepest low-power state to take into consideration.
686  * Return value: Preferred power state of the device on success, -ENODEV
687  * if there's no 'struct acpi_device' for @dev, -EINVAL if @d_max_in is
688  * incorrect, or -ENODATA on ACPI method failure.
698 		return -EINVAL;  in acpi_pm_device_sleep_state()
711 		return -ENODEV;  in acpi_pm_device_sleep_state()
720 		return -EINVAL;  in acpi_pm_device_sleep_state()
723 		for (d_max = d_max_in; d_max > d_min; d_max--) {  in acpi_pm_device_sleep_state()
724 			if (adev->power.states[d_max].flags.valid)  in acpi_pm_device_sleep_state()
737  * acpi_pm_notify_work_func - ACPI devices wakeup notification work function.
742 	struct device *dev = context->dev;  in acpi_pm_notify_work_func()
755 	struct acpi_device_wakeup *wakeup = &adev->wakeup;  in __acpi_device_wakeup_enable()
761 	if (wakeup->enable_count >= INT_MAX) {  in __acpi_device_wakeup_enable()
762 		acpi_handle_info(adev->handle, "Wakeup enable count out of bounds!\n");  in __acpi_device_wakeup_enable()
765 	if (wakeup->enable_count > 0)  in __acpi_device_wakeup_enable()
772 	status = acpi_enable_gpe(wakeup->gpe_device, wakeup->gpe_number);  in __acpi_device_wakeup_enable()
775 		error = -EIO;  in __acpi_device_wakeup_enable()
779 	acpi_handle_debug(adev->handle, "GPE%2X enabled for wakeup\n",  in __acpi_device_wakeup_enable()
780 			  (unsigned int)wakeup->gpe_number);  in __acpi_device_wakeup_enable()
783 	wakeup->enable_count++;  in __acpi_device_wakeup_enable()
791  * acpi_device_wakeup_enable - Enable wakeup functionality for device.
797  * power for it.
808  * acpi_device_wakeup_disable - Disable wakeup functionality for device.
809  * @adev: ACPI device to disable wakeup functionality for.
811  * Disable the GPE associated with @adev and disable wakeup power for it.
818 	struct acpi_device_wakeup *wakeup = &adev->wakeup;  in acpi_device_wakeup_disable()
822 	if (!wakeup->enable_count)  in acpi_device_wakeup_disable()
825 	acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number);  in acpi_device_wakeup_disable()
828 	wakeup->enable_count--;  in acpi_device_wakeup_disable()
835  * acpi_pm_set_device_wakeup - Enable/disable remote wakeup for given device.
836  * @dev: Device to enable/disable to generate wakeup events.
837  * @enable: Whether to enable or disable the wakeup functionality.
847 		return -ENODEV;  in acpi_pm_set_device_wakeup()
851 		return -EINVAL;  in acpi_pm_set_device_wakeup()
868  * acpi_dev_pm_low_power - Put ACPI device into a low-power state.
869  * @dev: Device to put into a low-power state.
886  * acpi_dev_pm_full_power - Put ACPI device into the full-power state.
887  * @adev: ACPI device node to put into the full-power state.
896  * acpi_dev_suspend - Put device into a low-power state using ACPI.
897  * @dev: Device to put into a low-power state.
900  * Put the given device into a low-power state using the standard ACPI
903  * the power state of the device.
917 			return -EAGAIN;  in acpi_dev_suspend()
931  * acpi_dev_resume - Put device into the full-power state using ACPI.
932  * @dev: Device to put into the full-power state.
934  * Put the given device into the full-power state using the standard ACPI
935  * mechanism.  Set the power state of the device to ACPI D0 and disable wakeup.
952  * acpi_subsys_runtime_suspend - Suspend device using ACPI.
956  * it into a runtime low-power state.
966  * acpi_subsys_runtime_resume - Resume device using ACPI.
969  * Use ACPI to put the given device into the full-power state and carry out the
985 	if (!pm_runtime_suspended(dev) || !adev || (adev->wakeup.flags.valid &&  in acpi_dev_needs_resume()
986 	    device_may_wakeup(dev) != !!adev->wakeup.prepare_count))  in acpi_dev_needs_resume()
992 	if (adev->power.flags.dsw_present)  in acpi_dev_needs_resume()
999 	return state != adev->power.state;  in acpi_dev_needs_resume()
1003  * acpi_subsys_prepare - Prepare device for system transition to a sleep state.
1010 	if (dev->driver && dev->driver->pm && dev->driver->pm->prepare) {  in acpi_subsys_prepare()
1011 		int ret = dev->driver->pm->prepare(dev);  in acpi_subsys_prepare()
1025  * acpi_subsys_complete - Finalize device's resume during system resume.
1032 	 * If the device had been runtime-suspended before the system went into  in acpi_subsys_complete()
1042  * acpi_subsys_suspend - Run the device driver's suspend callback.
1046  * system suspend callbacks, unless the driver can cope with runtime-suspended
1047  * devices during system suspend and there are no ACPI-specific reasons for
1061  * acpi_subsys_suspend_late - Suspend device using ACPI.
1065  * it into a low-power state during system transition into a sleep state.
1080  * acpi_subsys_suspend_noirq - Run the device driver's "noirq" suspend callback.
1095 	 * If the target system sleep state is suspend-to-idle, it is sufficient  in acpi_subsys_suspend_noirq()
1102 		dev->power.may_skip_resume = false;  in acpi_subsys_suspend_noirq()
1109  * acpi_subsys_resume_noirq - Run the device driver's "noirq" resume callback.
1121  * acpi_subsys_resume_early - Resume device using ACPI.
1124  * Use ACPI to put the given device into the full-power state and carry out the
1140  * acpi_subsys_freeze - Run the device driver's freeze callback.
1146 	 * Resume all runtime-suspended devices before creating a snapshot  in acpi_subsys_freeze()
1149 	 * put into the runtime-active metastate during system resume anyway,  in acpi_subsys_freeze()
1160  * acpi_subsys_restore_early - Restore device using ACPI.
1171  * acpi_subsys_poweroff - Run the device driver's poweroff callback.
1175  * system poweroff callbacks, unless the driver can cope with runtime-suspended
1176  * devices during system suspend and there are no ACPI-specific reasons for
1190  * acpi_subsys_poweroff_late - Run the device driver's poweroff callback.
1194  * it into a low-power state during system transition into a sleep state.
1211  * acpi_subsys_poweroff_noirq - Run the driver's "noirq" poweroff callback.
1245  * acpi_dev_pm_detach - Remove ACPI power management from the device.
1247  * @power_off: Whether or not to try to remove power from the device.
1250  * notifier.  If @power_off is set, additionally remove power from the device if
1253  * Callers must ensure proper synchronization of this function with power
1260 	if (adev && dev->pm_domain == &acpi_general_pm_domain) {  in acpi_dev_pm_detach()
1268 			 * choice of the low-power state to put the device into.  in acpi_dev_pm_detach()
1279  * acpi_dev_pm_attach - Prepare device for ACPI power management.
1281  * @power_on: Whether or not to power on the device.
1288  * This assumes that the @dev's bus type uses generic power management callbacks
1289  * (or doesn't use any power management callbacks at all).
1291  * Callers must ensure proper synchronization of this function with power
1298 	 * because they require special power management handling incompatible  in acpi_dev_pm_attach()
1311 	 * Only attach the power domain to the first device if the  in acpi_dev_pm_attach()
1312 	 * companion is shared by multiple. This is to prevent doing power  in acpi_dev_pm_attach()
1325 	dev->pm_domain->detach = acpi_dev_pm_detach;  in acpi_dev_pm_attach()