1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2008 Intel Corp
4 * Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com>
5 * Copyright (C) 2008 Sujith Thomas <sujith.thomas@intel.com>
6 * Copyright 2022 Linaro Limited
8 * Thermal trips handling
10 #include "thermal_core.h"
12 int for_each_thermal_trip(struct thermal_zone_device *tz,
13 int (*cb)(struct thermal_trip *, void *),
16 struct thermal_trip *trip;
19 for_each_trip(tz, trip) {
27 EXPORT_SYMBOL_GPL(for_each_thermal_trip);
29 int thermal_zone_for_each_trip(struct thermal_zone_device *tz,
30 int (*cb)(struct thermal_trip *, void *),
35 mutex_lock(&tz->lock);
36 ret = for_each_thermal_trip(tz, cb, data);
37 mutex_unlock(&tz->lock);
41 EXPORT_SYMBOL_GPL(thermal_zone_for_each_trip);
43 int thermal_zone_get_num_trips(struct thermal_zone_device *tz)
47 EXPORT_SYMBOL_GPL(thermal_zone_get_num_trips);
50 * __thermal_zone_set_trips - Computes the next trip points for the driver
51 * @tz: a pointer to a thermal zone device structure
53 * The function computes the next temperature boundaries by browsing
54 * the trip points. The result is the closer low and high trip points
55 * to the current temperature. These values are passed to the backend
56 * driver to let it set its own notification mechanism (usually an
59 * This function must be called with tz->lock held. Both tz and tz->ops
60 * must be valid pointers.
62 * It does not return a value
64 void __thermal_zone_set_trips(struct thermal_zone_device *tz)
66 struct thermal_trip trip;
67 int low = -INT_MAX, high = INT_MAX;
68 bool same_trip = false;
71 lockdep_assert_held(&tz->lock);
73 if (!tz->ops->set_trips)
76 for (i = 0; i < tz->num_trips; i++) {
80 ret = __thermal_zone_get_trip(tz, i , &trip);
84 trip_low = trip.temperature - trip.hysteresis;
86 if (trip_low < tz->temperature && trip_low > low) {
92 if (trip.temperature > tz->temperature &&
93 trip.temperature < high) {
94 high = trip.temperature;
99 /* No need to change trip points */
100 if (tz->prev_low_trip == low && tz->prev_high_trip == high)
104 * If "high" and "low" are the same, skip the change unless this is the
107 if (same_trip && (tz->prev_low_trip != -INT_MAX ||
108 tz->prev_high_trip != INT_MAX))
111 tz->prev_low_trip = low;
112 tz->prev_high_trip = high;
115 "new temperature boundaries: %d < x < %d\n", low, high);
118 * Set a temperature window. When this window is left the driver
119 * must inform the thermal core via thermal_zone_device_update.
121 ret = tz->ops->set_trips(tz, low, high);
123 dev_err(&tz->device, "Failed to set trips: %d\n", ret);
126 int __thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
127 struct thermal_trip *trip)
129 if (!tz || !tz->trips || trip_id < 0 || trip_id >= tz->num_trips || !trip)
132 *trip = tz->trips[trip_id];
135 EXPORT_SYMBOL_GPL(__thermal_zone_get_trip);
137 int thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
138 struct thermal_trip *trip)
142 mutex_lock(&tz->lock);
143 ret = __thermal_zone_get_trip(tz, trip_id, trip);
144 mutex_unlock(&tz->lock);
148 EXPORT_SYMBOL_GPL(thermal_zone_get_trip);
150 int thermal_zone_set_trip(struct thermal_zone_device *tz, int trip_id,
151 const struct thermal_trip *trip)
153 struct thermal_trip t;
156 if (!tz->ops->set_trip_temp && !tz->ops->set_trip_hyst && !tz->trips)
159 ret = __thermal_zone_get_trip(tz, trip_id, &t);
163 if (t.type != trip->type)
166 if (t.temperature != trip->temperature && tz->ops->set_trip_temp) {
167 ret = tz->ops->set_trip_temp(tz, trip_id, trip->temperature);
172 if (t.hysteresis != trip->hysteresis && tz->ops->set_trip_hyst) {
173 ret = tz->ops->set_trip_hyst(tz, trip_id, trip->hysteresis);
178 if (tz->trips && (t.temperature != trip->temperature || t.hysteresis != trip->hysteresis))
179 tz->trips[trip_id] = *trip;
181 thermal_notify_tz_trip_change(tz->id, trip_id, trip->type,
182 trip->temperature, trip->hysteresis);
184 __thermal_zone_device_update(tz, THERMAL_TRIP_CHANGED);
189 int thermal_zone_trip_id(struct thermal_zone_device *tz,
190 const struct thermal_trip *trip)
193 * Assume the trip to be located within the bounds of the thermal
194 * zone's trips[] table.
196 return trip - tz->trips;