1 // SPDX-License-Identifier: GPL-2.0-only
3  * drivers/acpi/device_pm.c - ACPI device power management routines.
27  * acpi_power_state_string - String representation of ACPI device power state.
28  * @state: ACPI device power state to return the string representation of.
53 	status = acpi_evaluate_integer(device->handle, "_PSC", NULL, &psc);  in acpi_dev_pm_explicit_get()
55 		return -ENODEV;  in acpi_dev_pm_explicit_get()
62  * acpi_device_get_power - Get power state of an ACPI device.
63  * @device: Device to get the power state of.
64  * @state: Place to store the power state of the device.
66  * This function does not update the device's power.state field, but it may
67  * update its parent's power.state field (when the parent's power state is
68  * unknown and the device's power state turns out to be D0).
70  * Also, it does not update power resource reference counters to ensure that
71  * the power state returned by it will be persistent and it may return a power
73  * (if that power state depends on any power resources).
81 		return -EINVAL;  in acpi_device_get_power()
83 	if (!device->flags.power_manageable) {  in acpi_device_get_power()
84 		/* TBD: Non-recursive algorithm for walking up hierarchy. */  in acpi_device_get_power()
85 		*state = device->parent ?  in acpi_device_get_power()
86 			device->parent->power.state : ACPI_STATE_D0;  in acpi_device_get_power()
91 	 * Get the device's power state from power resources settings and _PSC,  in acpi_device_get_power()
94 	if (device->power.flags.power_resources) {  in acpi_device_get_power()
99 	if (device->power.flags.explicit_get) {  in acpi_device_get_power()
107 		 * The power resources settings may indicate a power state  in acpi_device_get_power()
108 		 * shallower than the actual power state of the device, because  in acpi_device_get_power()
109 		 * the same power resources may be referenced by other devices.  in acpi_device_get_power()
121 	 * If we were unsure about the device parent's power state up to this  in acpi_device_get_power()
125 	if (!device->power.flags.ignore_parent && device->parent  in acpi_device_get_power()
126 	    && device->parent->power.state == ACPI_STATE_UNKNOWN  in acpi_device_get_power()
128 		device->parent->power.state = ACPI_STATE_D0;  in acpi_device_get_power()
133 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is %s\n",  in acpi_device_get_power()
134 			  device->pnp.bus_id, acpi_power_state_string(*state)));  in acpi_device_get_power()
141 	if (adev->power.states[state].flags.explicit_set) {  in acpi_dev_pm_explicit_set()
145 		status = acpi_evaluate_object(adev->handle, method, NULL, NULL);  in acpi_dev_pm_explicit_set()
147 			return -ENODEV;  in acpi_dev_pm_explicit_set()
153  * acpi_device_set_power - Set power state of an ACPI device.
154  * @device: Device to set the power state of.
155  * @state: New power state to set.
157  * Callers must ensure that the device is power manageable before using this
165 	if (!device || !device->flags.power_manageable  in acpi_device_set_power()
167 		return -EINVAL;  in acpi_device_set_power()
169 	acpi_handle_debug(device->handle, "Power state change: %s -> %s\n",  in acpi_device_set_power()
170 			  acpi_power_state_string(device->power.state),  in acpi_device_set_power()
176 	if (state > ACPI_STATE_D0 && state == device->power.state) {  in acpi_device_set_power()
178 				  device->pnp.bus_id,  in acpi_device_set_power()
186 		 * possibly drop references to the power resources in use.  in acpi_device_set_power()
190 		if (!device->power.states[ACPI_STATE_D3_COLD].flags.valid)  in acpi_device_set_power()
192 	} else if (!device->power.states[state].flags.valid) {  in acpi_device_set_power()
193 		dev_warn(&device->dev, "Power state %s not supported\n",  in acpi_device_set_power()
195 		return -ENODEV;  in acpi_device_set_power()
198 	if (!device->power.flags.ignore_parent &&  in acpi_device_set_power()
199 	    device->parent && (state < device->parent->power.state)) {  in acpi_device_set_power()
200 		dev_warn(&device->dev,  in acpi_device_set_power()
201 			 "Cannot transition to power state %s for parent in %s\n",  in acpi_device_set_power()
203 			 acpi_power_state_string(device->parent->power.state));  in acpi_device_set_power()
204 		return -ENODEV;  in acpi_device_set_power()
208 	 * Transition Power  in acpi_device_set_power()
209 	 * ----------------  in acpi_device_set_power()
210 	 * In accordance with ACPI 6, _PSx is executed before manipulating power  in acpi_device_set_power()
212 	 * supposed to be executed after turning the power resources on.  in acpi_device_set_power()
216 		 * According to ACPI 6, devices cannot go from lower-power  in acpi_device_set_power()
217 		 * (deeper) states to higher-power (shallower) states.  in acpi_device_set_power()
219 		if (state < device->power.state) {  in acpi_device_set_power()
220 			dev_warn(&device->dev, "Cannot transition from %s to %s\n",  in acpi_device_set_power()
221 				 acpi_power_state_string(device->power.state),  in acpi_device_set_power()
223 			return -ENODEV;  in acpi_device_set_power()
230 		if (device->power.state < ACPI_STATE_D3_HOT) {  in acpi_device_set_power()
236 		if (device->power.flags.power_resources)  in acpi_device_set_power()
239 		int cur_state = device->power.state;  in acpi_device_set_power()
241 		if (device->power.flags.power_resources) {  in acpi_device_set_power()
251 			if (!device->power.flags.explicit_get)  in acpi_device_set_power()
255 			 * The power state of the device was set to D0 last  in acpi_device_set_power()
257 			 * system-wide transition involving the platform  in acpi_device_set_power()
260 			 * and evaluate _PSC to check the device's current power  in acpi_device_set_power()
262 			 * is successful and it returns a power state different  in acpi_device_set_power()
275 		dev_warn(&device->dev, "Failed to change power state to %s\n",  in acpi_device_set_power()
278 		device->power.state = target_state;  in acpi_device_set_power()
281 				  device->pnp.bus_id,  in acpi_device_set_power()
308 		return -EINVAL;  in acpi_bus_init_power()
310 	device->power.state = ACPI_STATE_UNKNOWN;  in acpi_bus_init_power()
312 		device->flags.initialized = false;  in acpi_bus_init_power()
313 		return -ENXIO;  in acpi_bus_init_power()
320 	if (state < ACPI_STATE_D3_COLD && device->power.flags.power_resources) {  in acpi_bus_init_power()
321 		/* Reference count the power resources. */  in acpi_bus_init_power()
329 			 * power resources appears to be D0, it still may be  in acpi_bus_init_power()
331 			 * another device using the same power resources may  in acpi_bus_init_power()
341 		 * No power resources and missing _PSC?  Cross fingers and make  in acpi_bus_init_power()
344 		 * Toshiba P870-303 in a nasty way.]  in acpi_bus_init_power()
348 	device->power.state = state;  in acpi_bus_init_power()
353  * acpi_device_fix_up_power - Force device with missing _PSC into D0.
354  * @device: Device object whose power state is to be fixed up.
356  * Devices without power resources and _PSC, but having _PS0 and _PS3 defined,
364 	if (!device->power.flags.power_resources  in acpi_device_fix_up_power()
365 	    && !device->power.flags.explicit_get  in acpi_device_fix_up_power()
366 	    && device->power.state == ACPI_STATE_D0)  in acpi_device_fix_up_power()
378 	if (device->power.state == ACPI_STATE_UNKNOWN) {  in acpi_device_update_power()
381 			*state_p = device->power.state;  in acpi_device_update_power()
396 		if (device->power.flags.power_resources) {  in acpi_device_update_power()
399 			 * to update the power resources' reference counters.  in acpi_device_update_power()
405 		device->power.state = state;  in acpi_device_update_power()
430 	return result ? false : device->flags.power_manageable;  in acpi_bus_power_manageable()
459 	if (adev->wakeup.flags.notifier_present) {  in acpi_pm_notify_handler()
460 		pm_wakeup_ws_event(adev->wakeup.ws, 0, acpi_s2idle_wakeup());  in acpi_pm_notify_handler()
461 		if (adev->wakeup.context.func) {  in acpi_pm_notify_handler()
463 					  adev->wakeup.context.func,  in acpi_pm_notify_handler()
464 					  dev_name(adev->wakeup.context.dev));  in acpi_pm_notify_handler()
465 			adev->wakeup.context.func(&adev->wakeup.context);  in acpi_pm_notify_handler()
475  * acpi_add_pm_notifier - Register PM notify handler for given ACPI device.
480  * NOTE: @adev need not be a run-wake or wakeup device to be a valid source of
495 	if (adev->wakeup.flags.notifier_present)  in acpi_add_pm_notifier()
498 	status = acpi_install_notify_handler(adev->handle, ACPI_SYSTEM_NOTIFY,  in acpi_add_pm_notifier()
504 	adev->wakeup.ws = wakeup_source_register(&adev->dev,  in acpi_add_pm_notifier()
505 						 dev_name(&adev->dev));  in acpi_add_pm_notifier()
506 	adev->wakeup.context.dev = dev;  in acpi_add_pm_notifier()
507 	adev->wakeup.context.func = func;  in acpi_add_pm_notifier()
508 	adev->wakeup.flags.notifier_present = true;  in acpi_add_pm_notifier()
517  * acpi_remove_pm_notifier - Unregister PM notifier from given ACPI device.
526 	if (!adev->wakeup.flags.notifier_present)  in acpi_remove_pm_notifier()
529 	status = acpi_remove_notify_handler(adev->handle,  in acpi_remove_pm_notifier()
536 	adev->wakeup.context.func = NULL;  in acpi_remove_pm_notifier()
537 	adev->wakeup.context.dev = NULL;  in acpi_remove_pm_notifier()
538 	wakeup_source_unregister(adev->wakeup.ws);  in acpi_remove_pm_notifier()
539 	adev->wakeup.flags.notifier_present = false;  in acpi_remove_pm_notifier()
553 	return result ? false : device->wakeup.flags.valid;  in acpi_bus_can_wakeup()
565  * acpi_dev_pm_get_state - Get preferred power state of ACPI device.
566  * @dev: Device whose preferred target power state to return.
569  * @d_min_p: Location to store the highest power state available to the device.
570  * @d_max_p: Location to store the lowest power state available to the device.
572  * Find the lowest power (highest number) and highest power (lowest number) ACPI
573  * device power states that the device can be in while the system is in the
581  * Returns 0 on success or -ENODATA when one of the ACPI methods fails or
589 	acpi_handle handle = adev->handle;  in acpi_dev_pm_get_state()
597 	 * If the system state is S0, the lowest power state the device can be  in acpi_dev_pm_get_state()
600 	 * lowest power state available to the device.  in acpi_dev_pm_get_state()
606 	 * If present, _SxD methods return the minimum D-state (highest power  in acpi_dev_pm_get_state()
607 	 * state) we can use for the corresponding S-states.  Otherwise, the  in acpi_dev_pm_get_state()
608 	 * minimum D-state is D0 (ACPI 3.x).  in acpi_dev_pm_get_state()
619 			return -ENODATA;  in acpi_dev_pm_get_state()
626 		if (!adev->power.states[ret].flags.valid) {  in acpi_dev_pm_get_state()
630 				return -ENODATA;  in acpi_dev_pm_get_state()
637 		wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid  in acpi_dev_pm_get_state()
638 			&& adev->wakeup.sleep_state >= target_state;  in acpi_dev_pm_get_state()
640 		wakeup = adev->wakeup.flags.valid;  in acpi_dev_pm_get_state()
645 	 * the D-state returned by _SxD is sufficient for that (we assume a  in acpi_dev_pm_get_state()
646 	 * wakeup-aware driver if wake is set).  Still, if _SxW exists  in acpi_dev_pm_get_state()
647 	 * (ACPI 3.x), it should return the maximum (lowest power) D-state that  in acpi_dev_pm_get_state()
655 			 * must not go into any power state deeper than the  in acpi_dev_pm_get_state()
662 			if (!adev->power.states[ret].flags.valid)  in acpi_dev_pm_get_state()
667 			return -ENODATA;  in acpi_dev_pm_get_state()
681  * acpi_pm_device_sleep_state - Get preferred power state of ACPI device.
682  * @dev: Device whose preferred target power state to return.
684  * @d_max_in: Deepest low-power state to take into consideration.
685  * Return value: Preferred power state of the device on success, -ENODEV
686  * if there's no 'struct acpi_device' for @dev, -EINVAL if @d_max_in is
687  * incorrect, or -ENODATA on ACPI method failure.
697 		return -EINVAL;  in acpi_pm_device_sleep_state()
710 		return -ENODEV;  in acpi_pm_device_sleep_state()
719 		return -EINVAL;  in acpi_pm_device_sleep_state()
722 		for (d_max = d_max_in; d_max > d_min; d_max--) {  in acpi_pm_device_sleep_state()
723 			if (adev->power.states[d_max].flags.valid)  in acpi_pm_device_sleep_state()
736  * acpi_pm_notify_work_func - ACPI devices wakeup notification work function.
741 	struct device *dev = context->dev;  in acpi_pm_notify_work_func()
754 	struct acpi_device_wakeup *wakeup = &adev->wakeup;  in __acpi_device_wakeup_enable()
760 	if (wakeup->enable_count >= max_count)  in __acpi_device_wakeup_enable()
763 	if (wakeup->enable_count > 0)  in __acpi_device_wakeup_enable()
770 	status = acpi_enable_gpe(wakeup->gpe_device, wakeup->gpe_number);  in __acpi_device_wakeup_enable()
773 		error = -EIO;  in __acpi_device_wakeup_enable()
777 	acpi_handle_debug(adev->handle, "GPE%2X enabled for wakeup\n",  in __acpi_device_wakeup_enable()
778 			  (unsigned int)wakeup->gpe_number);  in __acpi_device_wakeup_enable()
781 	wakeup->enable_count++;  in __acpi_device_wakeup_enable()
789  * acpi_device_wakeup_enable - Enable wakeup functionality for device.
790  * @adev: ACPI device to enable wakeup functionality for.
793  * Enable the GPE associated with @adev so that it can generate wakeup signals
794  * for the device in response to external (remote) events and enable wakeup
795  * power for it.
806  * acpi_device_wakeup_disable - Disable wakeup functionality for device.
809  * Disable the GPE associated with @adev and disable wakeup power for it.
816 	struct acpi_device_wakeup *wakeup = &adev->wakeup;  in acpi_device_wakeup_disable()
820 	if (!wakeup->enable_count)  in acpi_device_wakeup_disable()
823 	acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number);  in acpi_device_wakeup_disable()
826 	wakeup->enable_count--;  in acpi_device_wakeup_disable()
832 static int __acpi_pm_set_device_wakeup(struct device *dev, bool enable,  in __acpi_pm_set_device_wakeup()  argument
841 		return -ENODEV;  in __acpi_pm_set_device_wakeup()
845 		return -EINVAL;  in __acpi_pm_set_device_wakeup()
847 	if (!enable) {  in __acpi_pm_set_device_wakeup()
862  * acpi_pm_set_device_wakeup - Enable/disable remote wakeup for given device.
863  * @dev: Device to enable/disable to generate wakeup events.
864  * @enable: Whether to enable or disable the wakeup functionality.
866 int acpi_pm_set_device_wakeup(struct device *dev, bool enable)  in acpi_pm_set_device_wakeup()  argument
868 	return __acpi_pm_set_device_wakeup(dev, enable, 1);  in acpi_pm_set_device_wakeup()
873  * acpi_pm_set_bridge_wakeup - Enable/disable remote wakeup for given bridge.
874  * @dev: Bridge device to enable/disable to generate wakeup events.
875  * @enable: Whether to enable or disable the wakeup functionality.
877 int acpi_pm_set_bridge_wakeup(struct device *dev, bool enable)  in acpi_pm_set_bridge_wakeup()  argument
879 	return __acpi_pm_set_device_wakeup(dev, enable, INT_MAX);  in acpi_pm_set_bridge_wakeup()
884  * acpi_dev_pm_low_power - Put ACPI device into a low-power state.
885  * @dev: Device to put into a low-power state.
902  * acpi_dev_pm_full_power - Put ACPI device into the full-power state.
903  * @adev: ACPI device node to put into the full-power state.
912  * acpi_dev_suspend - Put device into a low-power state using ACPI.
913  * @dev: Device to put into a low-power state.
914  * @wakeup: Whether or not to enable wakeup for the device.
916  * Put the given device into a low-power state using the standard ACPI
919  * the power state of the device.
933 			return -EAGAIN;  in acpi_dev_suspend()
947  * acpi_dev_resume - Put device into the full-power state using ACPI.
948  * @dev: Device to put into the full-power state.
950  * Put the given device into the full-power state using the standard ACPI
951  * mechanism.  Set the power state of the device to ACPI D0 and disable wakeup.
968  * acpi_subsys_runtime_suspend - Suspend device using ACPI.
972  * it into a runtime low-power state.
982  * acpi_subsys_runtime_resume - Resume device using ACPI.
985  * Use ACPI to put the given device into the full-power state and carry out the
1001 	if (!pm_runtime_suspended(dev) || !adev || (adev->wakeup.flags.valid &&  in acpi_dev_needs_resume()
1002 	    device_may_wakeup(dev) != !!adev->wakeup.prepare_count))  in acpi_dev_needs_resume()
1008 	if (adev->power.flags.dsw_present)  in acpi_dev_needs_resume()
1015 	return state != adev->power.state;  in acpi_dev_needs_resume()
1019  * acpi_subsys_prepare - Prepare device for system transition to a sleep state.
1026 	if (dev->driver && dev->driver->pm && dev->driver->pm->prepare) {  in acpi_subsys_prepare()
1027 		int ret = dev->driver->pm->prepare(dev);  in acpi_subsys_prepare()
1041  * acpi_subsys_complete - Finalize device's resume during system resume.
1048 	 * If the device had been runtime-suspended before the system went into  in acpi_subsys_complete()
1058  * acpi_subsys_suspend - Run the device driver's suspend callback.
1062  * system suspend callbacks, unless the driver can cope with runtime-suspended
1063  * devices during system suspend and there are no ACPI-specific reasons for
1077  * acpi_subsys_suspend_late - Suspend device using ACPI.
1081  * it into a low-power state during system transition into a sleep state.
1096  * acpi_subsys_suspend_noirq - Run the device driver's "noirq" suspend callback.
1111 	 * If the target system sleep state is suspend-to-idle, it is sufficient  in acpi_subsys_suspend_noirq()
1118 		dev->power.may_skip_resume = false;  in acpi_subsys_suspend_noirq()
1125  * acpi_subsys_resume_noirq - Run the device driver's "noirq" resume callback.
1137  * acpi_subsys_resume_early - Resume device using ACPI.
1140  * Use ACPI to put the given device into the full-power state and carry out the
1156  * acpi_subsys_freeze - Run the device driver's freeze callback.
1162 	 * Resume all runtime-suspended devices before creating a snapshot  in acpi_subsys_freeze()
1165 	 * put into the runtime-active metastate during system resume anyway,  in acpi_subsys_freeze()
1176  * acpi_subsys_restore_early - Restore device using ACPI.
1187  * acpi_subsys_poweroff - Run the device driver's poweroff callback.
1191  * system poweroff callbacks, unless the driver can cope with runtime-suspended
1192  * devices during system suspend and there are no ACPI-specific reasons for
1206  * acpi_subsys_poweroff_late - Run the device driver's poweroff callback.
1210  * it into a low-power state during system transition into a sleep state.
1227  * acpi_subsys_poweroff_noirq - Run the driver's "noirq" poweroff callback.
1261  * acpi_dev_pm_detach - Remove ACPI power management from the device.
1263  * @power_off: Whether or not to try to remove power from the device.
1266  * notifier.  If @power_off is set, additionally remove power from the device if
1269  * Callers must ensure proper synchronization of this function with power
1276 	if (adev && dev->pm_domain == &acpi_general_pm_domain) {  in acpi_dev_pm_detach()
1284 			 * choice of the low-power state to put the device into.  in acpi_dev_pm_detach()
1295  * acpi_dev_pm_attach - Prepare device for ACPI power management.
1297  * @power_on: Whether or not to power on the device.
1304  * This assumes that the @dev's bus type uses generic power management callbacks
1305  * (or doesn't use any power management callbacks at all).
1307  * Callers must ensure proper synchronization of this function with power
1314 	 * because they require special power management handling incompatible  in acpi_dev_pm_attach()
1329 	 * Only attach the power domain to the first device if the  in acpi_dev_pm_attach()
1330 	 * companion is shared by multiple. This is to prevent doing power  in acpi_dev_pm_attach()
1343 	dev->pm_domain->detach = acpi_dev_pm_detach;  in acpi_dev_pm_attach()