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).
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 	dev_dbg(&device->dev, "Device power state is %s\n",  in acpi_device_get_power()
141 	if (adev->power.states[state].flags.explicit_set) {  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
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()
185 		 * possibly drop references to the power resources in use.  in acpi_device_set_power()
189 		if (!device->power.states[ACPI_STATE_D3_COLD].flags.valid)  in acpi_device_set_power()
191 	} else if (!device->power.states[state].flags.valid) {  in acpi_device_set_power()
192 		dev_warn(&device->dev, "Power state %s not supported\n",  in acpi_device_set_power()
197 	if (!device->power.flags.ignore_parent &&  in acpi_device_set_power()
198 	    device->parent && (state < device->parent->power.state)) {  in acpi_device_set_power()
200 			 "Cannot transition to power state %s for parent in %s\n",  in acpi_device_set_power()
202 			 acpi_power_state_string(device->parent->power.state));  in acpi_device_set_power()
207 	 * Transition Power  in acpi_device_set_power()
209 	 * In accordance with ACPI 6, _PSx is executed before manipulating power  in acpi_device_set_power()
211 	 * supposed to be executed after turning the power resources on.  in acpi_device_set_power()
215 		 * According to ACPI 6, devices cannot go from lower-power  in acpi_device_set_power()
216 		 * (deeper) states to higher-power (shallower) states.  in acpi_device_set_power()
218 		if (state < device->power.state) {  in acpi_device_set_power()
220 				 acpi_power_state_string(device->power.state),  in acpi_device_set_power()
229 		if (device->power.state < ACPI_STATE_D3_HOT) {  in acpi_device_set_power()
235 		if (device->power.flags.power_resources)  in acpi_device_set_power()
238 		int cur_state = device->power.state;  in acpi_device_set_power()
240 		if (device->power.flags.power_resources) {  in acpi_device_set_power()
250 			if (!device->power.flags.explicit_get)  in acpi_device_set_power()
254 			 * The power state of the device was set to D0 last  in acpi_device_set_power()
259 			 * and evaluate _PSC to check the device's current power  in acpi_device_set_power()
261 			 * is successful and it returns a power state different  in acpi_device_set_power()
274 		dev_warn(&device->dev, "Failed to change power state to %s\n",  in acpi_device_set_power()
277 		device->power.state = target_state;  in acpi_device_set_power()
278 		dev_dbg(&device->dev, "Power state changed to %s\n",  in acpi_device_set_power()
307 	device->power.state = ACPI_STATE_UNKNOWN;  in acpi_bus_init_power()
317 	if (state < ACPI_STATE_D3_COLD && device->power.flags.power_resources) {  in acpi_bus_init_power()
318 		/* Reference count the power resources. */  in acpi_bus_init_power()
326 			 * power resources appears to be D0, it still may be  in acpi_bus_init_power()
328 			 * another device using the same power resources may  in acpi_bus_init_power()
338 		 * No power resources and missing _PSC?  Cross fingers and make  in acpi_bus_init_power()
345 	device->power.state = state;  in acpi_bus_init_power()
351  * @device: Device object whose power state is to be fixed up.
353  * Devices without power resources and _PSC, but having _PS0 and _PS3 defined,
361 	if (!device->power.flags.power_resources  in acpi_device_fix_up_power()
362 	    && !device->power.flags.explicit_get  in acpi_device_fix_up_power()
363 	    && device->power.state == ACPI_STATE_D0)  in acpi_device_fix_up_power()
375 	if (device->power.state == ACPI_STATE_UNKNOWN) {  in acpi_device_update_power()
378 			*state_p = device->power.state;  in acpi_device_update_power()
393 		if (device->power.flags.power_resources) {  in acpi_device_update_power()
396 			 * to update the power resources' reference counters.  in acpi_device_update_power()
402 		device->power.state = state;  in acpi_device_update_power()
562  * acpi_dev_pm_get_state - Get preferred power state of ACPI device.
563  * @dev: Device whose preferred target power state to return.
566  * @d_min_p: Location to store the highest power state available to the device.
567  * @d_max_p: Location to store the lowest power state available to the device.
569  * Find the lowest power (highest number) and highest power (lowest number) ACPI
570  * device power states that the device can be in while the system is in the
594 	 * If the system state is S0, the lowest power state the device can be  in acpi_dev_pm_get_state()
597 	 * lowest power state available to the device.  in acpi_dev_pm_get_state()
603 	 * If present, _SxD methods return the minimum D-state (highest power  in acpi_dev_pm_get_state()
623 		if (!adev->power.states[ret].flags.valid) {  in acpi_dev_pm_get_state()
644 	 * (ACPI 3.x), it should return the maximum (lowest power) D-state that  in acpi_dev_pm_get_state()
652 			 * must not go into any power state deeper than the  in acpi_dev_pm_get_state()
659 			if (!adev->power.states[ret].flags.valid)  in acpi_dev_pm_get_state()
678  * acpi_pm_device_sleep_state - Get preferred power state of ACPI device.
679  * @dev: Device whose preferred target power state to return.
681  * @d_max_in: Deepest low-power state to take into consideration.
682  * Return value: Preferred power state of the device on success, -ENODEV
720 			if (adev->power.states[d_max].flags.valid)  in acpi_pm_device_sleep_state()
758 	 * If the device wakeup power is already enabled, disable it and enable  in __acpi_device_wakeup_enable()
806  * power for it.
820  * Disable the GPE associated with @adev and disable wakeup power for it.
877  * acpi_dev_pm_low_power - Put ACPI device into a low-power state.
878  * @dev: Device to put into a low-power state.
895  * acpi_dev_pm_full_power - Put ACPI device into the full-power state.
896  * @adev: ACPI device node to put into the full-power state.
905  * acpi_dev_suspend - Put device into a low-power state using ACPI.
906  * @dev: Device to put into a low-power state.
909  * Put the given device into a low-power state using the standard ACPI
912  * the power state of the device.
940  * acpi_dev_resume - Put device into the full-power state using ACPI.
941  * @dev: Device to put into the full-power state.
943  * Put the given device into the full-power state using the standard ACPI
944  * mechanism.  Set the power state of the device to ACPI D0 and disable wakeup.
965  * it into a runtime low-power state.
979  * Use ACPI to put the given device into the full-power state and carry out the
1003 	if (adev->power.flags.dsw_present)  in acpi_dev_needs_resume()
1010 	return state != adev->power.state;  in acpi_dev_needs_resume()
1076  * it into a low-power state during system transition into a sleep state.
1113 		dev->power.may_skip_resume = false;  in acpi_subsys_suspend_noirq()
1135  * Use ACPI to put the given device into the full-power state and carry out the
1138  * handler, or does not define power operations at all. Otherwise powering up
1162  * Use ACPI to put the given device into the full-power state if it has not been
1235  * it into a low-power state during system transition into a sleep state.
1287  * acpi_dev_pm_detach - Remove ACPI power management from the device.
1289  * @power_off: Whether or not to try to remove power from the device.
1292  * notifier.  If @power_off is set, additionally remove power from the device if
1295  * Callers must ensure proper synchronization of this function with power
1310 			 * choice of the low-power state to put the device into.  in acpi_dev_pm_detach()
1321  * acpi_dev_pm_attach - Prepare device for ACPI power management.
1323  * @power_on: Whether or not to power on the device.
1330  * This assumes that the @dev's bus type uses generic power management callbacks
1331  * (or doesn't use any power management callbacks at all).
1333  * Callers must ensure proper synchronization of this function with power
1340 	 * because they require special power management handling incompatible  in acpi_dev_pm_attach()
1353 	 * Only attach the power domain to the first device if the  in acpi_dev_pm_attach()
1354 	 * companion is shared by multiple. This is to prevent doing power  in acpi_dev_pm_attach()