drivers/thermal/gov_bang_bang.c

1 // SPDX-License-Identifier: GPL-2.0-only
3  *  gov_bang_bang.c - A simple thermal throttling governor using hysteresis
12 #include <linux/thermal.h>
19 	if (instance->target != 0 && instance->target != 1 &&  in bang_bang_set_instance_target()
20 	    instance->target != THERMAL_NO_TARGET)  in bang_bang_set_instance_target()
21 		pr_debug("Unexpected state %ld of thermal instance %s in bang-bang\n",  in bang_bang_set_instance_target()
22 			 instance->target, instance->name);  in bang_bang_set_instance_target()
28 	instance->target = target;  in bang_bang_set_instance_target()
29 	instance->initialized = true;  in bang_bang_set_instance_target()
31 	dev_dbg(&instance->cdev->device, "target=%ld\n", instance->target);  in bang_bang_set_instance_target()
33 	mutex_lock(&instance->cdev->lock);  in bang_bang_set_instance_target()
34 	__thermal_cdev_update(instance->cdev);  in bang_bang_set_instance_target()
35 	mutex_unlock(&instance->cdev->lock);  in bang_bang_set_instance_target()
39  * bang_bang_control - controls devices associated with the given zone
44  * Regulation Logic: a two point regulation, deliver cooling state depending
51  *          trip_temp:    +---->+
55  * (trip_temp - hyst):    +<----+
63  *     (trip_temp - hyst) so that the fan gets turned off again.
72 	lockdep_assert_held(&tz->lock);  in bang_bang_control()
74 	dev_dbg(&tz->device, "Trip%d[temp=%d]:temp=%d:hyst=%d\n",  in bang_bang_control()
75 		thermal_zone_trip_id(tz, trip), trip->temperature,  in bang_bang_control()
76 		tz->temperature, trip->hysteresis);  in bang_bang_control()
78 	list_for_each_entry(instance, &tz->thermal_instances, tz_node) {  in bang_bang_control()
79 		if (instance->trip == trip)  in bang_bang_control()
90 	if (tz->governor_data)  in bang_bang_manage()
94 		const struct thermal_trip *trip = &td->trip;  in bang_bang_manage()
97 		if (trip->temperature == THERMAL_TEMP_INVALID ||  in bang_bang_manage()
98 		    trip->type == THERMAL_TRIP_CRITICAL ||  in bang_bang_manage()
99 		    trip->type == THERMAL_TRIP_HOT)  in bang_bang_manage()
103 		 * Adjust the target states for uninitialized thermal instances  in bang_bang_manage()
104 		 * to the thermal zone temperature and the trip point threshold.  in bang_bang_manage()
106 		turn_on = tz->temperature >= td->threshold;  in bang_bang_manage()
107 		list_for_each_entry(instance, &tz->thermal_instances, tz_node) {  in bang_bang_manage()
108 			if (!instance->initialized && instance->trip == trip)  in bang_bang_manage()
113 	tz->governor_data = (void *)true;  in bang_bang_manage()
124 		tz->governor_data = NULL;  in bang_bang_update_tz()