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.
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).
88 		*state = parent ? parent->power.state : ACPI_STATE_D0;  in acpi_device_get_power()
93 	 * Get the device's power state from power resources settings and _PSC,  in acpi_device_get_power()
96 	if (device->power.flags.power_resources) {  in acpi_device_get_power()
101 	if (device->power.flags.explicit_get) {  in acpi_device_get_power()
109 		 * The power resources settings may indicate a power state  in acpi_device_get_power()
110 		 * shallower than the actual power state of the device, because  in acpi_device_get_power()
111 		 * the same power resources may be referenced by other devices.  in acpi_device_get_power()
123 	 * If we were unsure about the device parent's power state up to this  in acpi_device_get_power()
127 	if (!device->power.flags.ignore_parent && parent &&  in acpi_device_get_power()
128 	    parent->power.state == ACPI_STATE_UNKNOWN &&  in acpi_device_get_power()
130 		parent->power.state = ACPI_STATE_D0;  in acpi_device_get_power()
135 	acpi_handle_debug(device->handle, "Power state: %s\n",  in acpi_device_get_power()
143 	if (adev->power.states[state].flags.explicit_set) {  in acpi_dev_pm_explicit_set()
155  * acpi_device_set_power - Set power state of an ACPI device.
156  * @device: Device to set the power state of.
157  * @state: New power state to set.
159  * Callers must ensure that the device is power manageable before using this
171 	acpi_handle_debug(device->handle, "Power state change: %s -> %s\n",  in acpi_device_set_power()
172 			  acpi_power_state_string(device->power.state),  in acpi_device_set_power()
178 	if (state > ACPI_STATE_D0 && state == device->power.state)  in acpi_device_set_power()
184 		 * possibly drop references to the power resources in use.  in acpi_device_set_power()
188 		if (!device->power.states[ACPI_STATE_D3_COLD].flags.valid)  in acpi_device_set_power()
190 	} else if (!device->power.states[state].flags.valid) {  in acpi_device_set_power()
191 		acpi_handle_debug(device->handle, "Power state %s not supported\n",  in acpi_device_set_power()
196 	if (!device->power.flags.ignore_parent) {  in acpi_device_set_power()
200 		if (parent && state < parent->power.state) {  in acpi_device_set_power()
204 					  acpi_power_state_string(parent->power.state));  in acpi_device_set_power()
210 	 * Transition Power  in acpi_device_set_power()
212 	 * In accordance with ACPI 6, _PSx is executed before manipulating power  in acpi_device_set_power()
214 	 * supposed to be executed after turning the power resources on.  in acpi_device_set_power()
218 		 * According to ACPI 6, devices cannot go from lower-power  in acpi_device_set_power()
219 		 * (deeper) states to higher-power (shallower) states.  in acpi_device_set_power()
221 		if (state < device->power.state) {  in acpi_device_set_power()
224 					  acpi_power_state_string(device->power.state),  in acpi_device_set_power()
233 		if (device->power.state < ACPI_STATE_D3_HOT) {  in acpi_device_set_power()
239 		if (device->power.flags.power_resources)  in acpi_device_set_power()
242 		int cur_state = device->power.state;  in acpi_device_set_power()
244 		if (device->power.flags.power_resources) {  in acpi_device_set_power()
254 			if (!device->power.flags.explicit_get)  in acpi_device_set_power()
258 			 * The power state of the device was set to D0 last  in acpi_device_set_power()
263 			 * and evaluate _PSC to check the device's current power  in acpi_device_set_power()
265 			 * is successful and it returns a power state different  in acpi_device_set_power()
279 				  "Failed to change power state to %s\n",  in acpi_device_set_power()
282 		device->power.state = target_state;  in acpi_device_set_power()
283 		acpi_handle_debug(device->handle, "Power state changed to %s\n",  in acpi_device_set_power()
315 	device->power.state = ACPI_STATE_UNKNOWN;  in acpi_bus_init_power()
325 	if (state < ACPI_STATE_D3_COLD && device->power.flags.power_resources) {  in acpi_bus_init_power()
326 		/* Reference count the power resources. */  in acpi_bus_init_power()
334 			 * power resources appears to be D0, it still may be  in acpi_bus_init_power()
336 			 * another device using the same power resources may  in acpi_bus_init_power()
346 		 * No power resources and missing _PSC?  Cross fingers and make  in acpi_bus_init_power()
353 	device->power.state = state;  in acpi_bus_init_power()
359  * @device: Device object whose power state is to be fixed up.
361  * Devices without power resources and _PSC, but having _PS0 and _PS3 defined,
369 	if (!device->power.flags.power_resources  in acpi_device_fix_up_power()
370 	    && !device->power.flags.explicit_get  in acpi_device_fix_up_power()
371 	    && device->power.state == ACPI_STATE_D0)  in acpi_device_fix_up_power()
388  * @adev: Parent device object whose power state is to be fixed up.
402  * @adev: Parent device object whose children's power state is to be fixed up.
418 	if (device->power.state == ACPI_STATE_UNKNOWN) {  in acpi_device_update_power()
421 			*state_p = device->power.state;  in acpi_device_update_power()
436 		if (device->power.flags.power_resources) {  in acpi_device_update_power()
439 			 * to update the power resources' reference counters.  in acpi_device_update_power()
445 		device->power.state = state;  in acpi_device_update_power()
478 	acpi_handle_debug(adev->handle, "Power state: %s\n",  in acpi_power_up_if_adr_present()
479 			  acpi_power_state_string(adev->power.state));  in acpi_power_up_if_adr_present()
481 	if (adev->power.state == ACPI_STATE_D3_COLD)  in acpi_power_up_if_adr_present()
488  * acpi_dev_power_up_children_with_adr - Power up childres with valid _ADR
491  * Change the power states of the direct children of @adev that are in D3cold
501  * acpi_dev_power_state_for_wake - Deepest power state for wakeup signaling
648  * acpi_dev_pm_get_state - Get preferred power state of ACPI device.
649  * @dev: Device whose preferred target power state to return.
652  * @d_min_p: Location to store the highest power state available to the device.
653  * @d_max_p: Location to store the lowest power state available to the device.
655  * Find the lowest power (highest number) and highest power (lowest number) ACPI
656  * device power states that the device can be in while the system is in the
680 	 * If the system state is S0, the lowest power state the device can be  in acpi_dev_pm_get_state()
683 	 * lowest power state available to the device.  in acpi_dev_pm_get_state()
689 	 * If present, _SxD methods return the minimum D-state (highest power  in acpi_dev_pm_get_state()
709 		if (!adev->power.states[ret].flags.valid) {  in acpi_dev_pm_get_state()
722 	} else if (device_may_wakeup(dev) && dev->power.wakeirq) {  in acpi_dev_pm_get_state()
745 	 * (ACPI 3.x), it should return the maximum (lowest power) D-state that  in acpi_dev_pm_get_state()
753 			 * must not go into any power state deeper than the  in acpi_dev_pm_get_state()
760 			if (!adev->power.states[ret].flags.valid)  in acpi_dev_pm_get_state()
779  * acpi_pm_device_sleep_state - Get preferred power state of ACPI device.
780  * @dev: Device whose preferred target power state to return.
782  * @d_max_in: Deepest low-power state to take into consideration.
783  * Return value: Preferred power state of the device on success, -ENODEV
821 			if (adev->power.states[d_max].flags.valid)  in acpi_pm_device_sleep_state()
859 	 * If the device wakeup power is already enabled, disable it and enable  in __acpi_device_wakeup_enable()
907  * power for it.
921  * Disable the GPE associated with @adev and disable wakeup power for it.
978  * acpi_dev_pm_low_power - Put ACPI device into a low-power state.
979  * @dev: Device to put into a low-power state.
996  * acpi_dev_pm_full_power - Put ACPI device into the full-power state.
997  * @adev: ACPI device node to put into the full-power state.
1006  * acpi_dev_suspend - Put device into a low-power state using ACPI.
1007  * @dev: Device to put into a low-power state.
1010  * Put the given device into a low-power state using the standard ACPI
1013  * the power state of the device.
1041  * acpi_dev_resume - Put device into the full-power state using ACPI.
1042  * @dev: Device to put into the full-power state.
1044  * Put the given device into the full-power state using the standard ACPI
1045  * mechanism.  Set the power state of the device to ACPI D0 and disable wakeup.
1066  * it into a runtime low-power state.
1080  * Use ACPI to put the given device into the full-power state and carry out the
1104 	if (adev->power.flags.dsw_present)  in acpi_dev_needs_resume()
1111 	return state != adev->power.state;  in acpi_dev_needs_resume()
1177  * it into a low-power state during system transition into a sleep state.
1214 		dev->power.may_skip_resume = false;  in acpi_subsys_suspend_noirq()
1236  * Use ACPI to put the given device into the full-power state and carry out the
1239  * handler, or does not define power operations at all. Otherwise powering up
1263  * Use ACPI to put the given device into the full-power state if it has not been
1336  * it into a low-power state during system transition into a sleep state.
1388  * acpi_dev_pm_detach - Remove ACPI power management from the device.
1390  * @power_off: Whether or not to try to remove power from the device.
1393  * notifier.  If @power_off is set, additionally remove power from the device if
1396  * Callers must ensure proper synchronization of this function with power
1411 			 * choice of the low-power state to put the device into.  in acpi_dev_pm_detach()
1422  * acpi_dev_pm_attach - Prepare device for ACPI power management.
1424  * @power_on: Whether or not to power on the device.
1431  * This assumes that the @dev's bus type uses generic power management callbacks
1432  * (or doesn't use any power management callbacks at all).
1434  * Callers must ensure proper synchronization of this function with power
1441 	 * because they require special power management handling incompatible  in acpi_dev_pm_attach()
1454 	 * Only attach the power domain to the first device if the  in acpi_dev_pm_attach()
1455 	 * companion is shared by multiple. This is to prevent doing power  in acpi_dev_pm_attach()
1505  * acpi_dev_state_d0 - Tell if the device is in D0 power state
1506  * @dev: Physical device the ACPI power state of which to check
1509  * the current ACPI power state of the device is D0, or false otherwise.
1511  * Note that the power state of a device is not well-defined after it has been
1513  * not valid to ask for the ACPI power state of the device in that time frame.
1526 	return adev->power.state == ACPI_STATE_D0;  in acpi_dev_state_d0()