1 // SPDX-License-Identifier: GPL-2.0-only
3  *  gov_bang_bang.c - A simple thermal throttling governor using hysteresis
14  *                Fan:   OFF    ON
18  *          trip_temp:    +---->+
22  * (trip_temp - hyst):    +<----+
28  *     gets turned on.
30  *     (trip_temp - hyst) so that the fan gets turned off again.
40 	if (instance->target != 0 && instance->target != 1 &&  in bang_bang_set_instance_target()
41 	    instance->target != THERMAL_NO_TARGET)  in bang_bang_set_instance_target()
42 		pr_debug("Unexpected state %ld of thermal instance %s in bang-bang\n",  in bang_bang_set_instance_target()
43 			 instance->target, instance->name);  in bang_bang_set_instance_target()
49 	instance->target = target;  in bang_bang_set_instance_target()
50 	instance->initialized = true;  in bang_bang_set_instance_target()
52 	dev_dbg(&instance->cdev->device, "target=%ld\n", instance->target);  in bang_bang_set_instance_target()
54 	thermal_cdev_update_nocheck(instance->cdev);  in bang_bang_set_instance_target()
58  * bang_bang_trip_crossed - controls devices associated with the given zone
70 	lockdep_assert_held(&tz->lock);  in bang_bang_trip_crossed()
72 	dev_dbg(&tz->device, "Trip%d[temp=%d]:temp=%d:hyst=%d\n",  in bang_bang_trip_crossed()
73 		thermal_zone_trip_id(tz, trip), trip->temperature,  in bang_bang_trip_crossed()
74 		tz->temperature, trip->hysteresis);  in bang_bang_trip_crossed()
76 	list_for_each_entry(instance, &td->thermal_instances, trip_node)  in bang_bang_trip_crossed()
86 	if (tz->governor_data)  in bang_bang_manage()
90 		const struct thermal_trip *trip = &td->trip;  in bang_bang_manage()
93 		if (trip->temperature == THERMAL_TEMP_INVALID ||  in bang_bang_manage()
94 		    trip->type == THERMAL_TRIP_CRITICAL ||  in bang_bang_manage()
95 		    trip->type == THERMAL_TRIP_HOT)  in bang_bang_manage()
102 		turn_on = tz->temperature >= td->threshold;  in bang_bang_manage()
103 		list_for_each_entry(instance, &td->thermal_instances, trip_node) {  in bang_bang_manage()
104 			if (!instance->initialized)  in bang_bang_manage()
109 	tz->governor_data = (void *)true;  in bang_bang_manage()
120 		tz->governor_data = NULL;  in bang_bang_update_tz()