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Durgadoss Re151a202012-09-21 12:06:04 +05301/*
2 * step_wise.c - A step-by-step Thermal throttling governor
3 *
4 * Copyright (C) 2012 Intel Corp
5 * Copyright (C) 2012 Durgadoss R <durgadoss.r@intel.com>
6 *
7 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; version 2 of the License.
12 *
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, write to the Free Software Foundation, Inc.,
20 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
21 *
22 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
23 */
24
Durgadoss Re151a202012-09-21 12:06:04 +053025#include <linux/thermal.h>
Punit Agrawal208cd822014-07-29 11:50:50 +010026#include <trace/events/thermal.h>
Durgadoss Re151a202012-09-21 12:06:04 +053027
28#include "thermal_core.h"
29
30/*
31 * If the temperature is higher than a trip point,
32 * a. if the trend is THERMAL_TREND_RAISING, use higher cooling
33 * state for this trip point
34 * b. if the trend is THERMAL_TREND_DROPPING, use lower cooling
35 * state for this trip point
Zhang Rui3dbfff32012-11-19 16:10:20 +080036 * c. if the trend is THERMAL_TREND_RAISE_FULL, use upper limit
37 * for this trip point
38 * d. if the trend is THERMAL_TREND_DROP_FULL, use lower limit
39 * for this trip point
40 * If the temperature is lower than a trip point,
41 * a. if the trend is THERMAL_TREND_RAISING, do nothing
42 * b. if the trend is THERMAL_TREND_DROPPING, use lower cooling
43 * state for this trip point, if the cooling state already
44 * equals lower limit, deactivate the thermal instance
45 * c. if the trend is THERMAL_TREND_RAISE_FULL, do nothing
46 * d. if the trend is THERMAL_TREND_DROP_FULL, use lower limit,
47 * if the cooling state already equals lower limit,
Brian Norris56b613e2015-01-29 09:57:21 -080048 * deactivate the thermal instance
Durgadoss Re151a202012-09-21 12:06:04 +053049 */
50static unsigned long get_target_state(struct thermal_instance *instance,
Zhang Rui3dbfff32012-11-19 16:10:20 +080051 enum thermal_trend trend, bool throttle)
Durgadoss Re151a202012-09-21 12:06:04 +053052{
53 struct thermal_cooling_device *cdev = instance->cdev;
54 unsigned long cur_state;
Eduardo Valentinca56caa2013-06-17 21:24:24 +080055 unsigned long next_target;
Durgadoss Re151a202012-09-21 12:06:04 +053056
Eduardo Valentinca56caa2013-06-17 21:24:24 +080057 /*
58 * We keep this instance the way it is by default.
59 * Otherwise, we use the current state of the
60 * cdev in use to determine the next_target.
61 */
Durgadoss Re151a202012-09-21 12:06:04 +053062 cdev->ops->get_cur_state(cdev, &cur_state);
Eduardo Valentinca56caa2013-06-17 21:24:24 +080063 next_target = instance->target;
Aaron Lu06475b52013-12-02 13:54:26 +080064 dev_dbg(&cdev->device, "cur_state=%ld\n", cur_state);
Durgadoss Re151a202012-09-21 12:06:04 +053065
Zhang Rui3dbfff32012-11-19 16:10:20 +080066 switch (trend) {
67 case THERMAL_TREND_RAISING:
Andrew Brestickere79fe642013-04-09 21:59:47 +000068 if (throttle) {
Eduardo Valentinca56caa2013-06-17 21:24:24 +080069 next_target = cur_state < instance->upper ?
Zhang Rui3dbfff32012-11-19 16:10:20 +080070 (cur_state + 1) : instance->upper;
Eduardo Valentinca56caa2013-06-17 21:24:24 +080071 if (next_target < instance->lower)
72 next_target = instance->lower;
Andrew Brestickere79fe642013-04-09 21:59:47 +000073 }
Zhang Rui3dbfff32012-11-19 16:10:20 +080074 break;
75 case THERMAL_TREND_RAISE_FULL:
76 if (throttle)
Eduardo Valentinca56caa2013-06-17 21:24:24 +080077 next_target = instance->upper;
Zhang Rui3dbfff32012-11-19 16:10:20 +080078 break;
79 case THERMAL_TREND_DROPPING:
Lukasz Majewski26bb0e92014-09-24 10:27:10 +020080 if (cur_state <= instance->lower) {
Zhang Rui3dbfff32012-11-19 16:10:20 +080081 if (!throttle)
Eduardo Valentinca56caa2013-06-17 21:24:24 +080082 next_target = THERMAL_NO_TARGET;
Andrew Brestickere79fe642013-04-09 21:59:47 +000083 } else {
Eduardo Valentinca56caa2013-06-17 21:24:24 +080084 next_target = cur_state - 1;
85 if (next_target > instance->upper)
86 next_target = instance->upper;
Andrew Brestickere79fe642013-04-09 21:59:47 +000087 }
Zhang Rui3dbfff32012-11-19 16:10:20 +080088 break;
89 case THERMAL_TREND_DROP_FULL:
90 if (cur_state == instance->lower) {
91 if (!throttle)
Eduardo Valentinca56caa2013-06-17 21:24:24 +080092 next_target = THERMAL_NO_TARGET;
Zhang Rui3dbfff32012-11-19 16:10:20 +080093 } else
Eduardo Valentinca56caa2013-06-17 21:24:24 +080094 next_target = instance->lower;
Zhang Rui3dbfff32012-11-19 16:10:20 +080095 break;
96 default:
97 break;
Durgadoss Re151a202012-09-21 12:06:04 +053098 }
99
Eduardo Valentinca56caa2013-06-17 21:24:24 +0800100 return next_target;
Durgadoss Re151a202012-09-21 12:06:04 +0530101}
102
103static void update_passive_instance(struct thermal_zone_device *tz,
104 enum thermal_trip_type type, int value)
105{
106 /*
107 * If value is +1, activate a passive instance.
108 * If value is -1, deactivate a passive instance.
109 */
110 if (type == THERMAL_TRIP_PASSIVE || type == THERMAL_TRIPS_NONE)
111 tz->passive += value;
112}
113
Durgadoss Re151a202012-09-21 12:06:04 +0530114static void thermal_zone_trip_update(struct thermal_zone_device *tz, int trip)
115{
116 long trip_temp;
117 enum thermal_trip_type trip_type;
118 enum thermal_trend trend;
Zhang Ruib8bb6cb2012-11-22 15:45:02 +0800119 struct thermal_instance *instance;
120 bool throttle = false;
121 int old_target;
Durgadoss Re151a202012-09-21 12:06:04 +0530122
123 if (trip == THERMAL_TRIPS_NONE) {
124 trip_temp = tz->forced_passive;
125 trip_type = THERMAL_TRIPS_NONE;
126 } else {
127 tz->ops->get_trip_temp(tz, trip, &trip_temp);
128 tz->ops->get_trip_type(tz, trip, &trip_type);
129 }
130
131 trend = get_tz_trend(tz, trip);
132
Punit Agrawal208cd822014-07-29 11:50:50 +0100133 if (tz->temperature >= trip_temp) {
Zhang Ruib8bb6cb2012-11-22 15:45:02 +0800134 throttle = true;
Punit Agrawal208cd822014-07-29 11:50:50 +0100135 trace_thermal_zone_trip(tz, trip, trip_type);
136 }
Zhang Ruib8bb6cb2012-11-22 15:45:02 +0800137
Aaron Lu06475b52013-12-02 13:54:26 +0800138 dev_dbg(&tz->device, "Trip%d[type=%d,temp=%ld]:trend=%d,throttle=%d\n",
139 trip, trip_type, trip_temp, trend, throttle);
140
Durgadoss Re151a202012-09-21 12:06:04 +0530141 mutex_lock(&tz->lock);
142
Zhang Ruib8bb6cb2012-11-22 15:45:02 +0800143 list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
144 if (instance->trip != trip)
145 continue;
146
147 old_target = instance->target;
148 instance->target = get_target_state(instance, trend, throttle);
Aaron Lu06475b52013-12-02 13:54:26 +0800149 dev_dbg(&instance->cdev->device, "old_target=%d, target=%d\n",
150 old_target, (int)instance->target);
Zhang Ruib8bb6cb2012-11-22 15:45:02 +0800151
Shawn Guo178c2492013-06-17 21:24:23 +0800152 if (old_target == instance->target)
153 continue;
154
Zhang Ruib8bb6cb2012-11-22 15:45:02 +0800155 /* Activate a passive thermal instance */
156 if (old_target == THERMAL_NO_TARGET &&
157 instance->target != THERMAL_NO_TARGET)
158 update_passive_instance(tz, trip_type, 1);
159 /* Deactivate a passive thermal instance */
160 else if (old_target != THERMAL_NO_TARGET &&
161 instance->target == THERMAL_NO_TARGET)
162 update_passive_instance(tz, trip_type, -1);
163
164
165 instance->cdev->updated = false; /* cdev needs update */
166 }
Durgadoss Re151a202012-09-21 12:06:04 +0530167
168 mutex_unlock(&tz->lock);
169}
170
171/**
Brian Norris56b613e2015-01-29 09:57:21 -0800172 * step_wise_throttle - throttles devices associated with the given zone
Durgadoss Re151a202012-09-21 12:06:04 +0530173 * @tz - thermal_zone_device
174 * @trip - the trip point
175 * @trip_type - type of the trip point
176 *
177 * Throttling Logic: This uses the trend of the thermal zone to throttle.
178 * If the thermal zone is 'heating up' this throttles all the cooling
179 * devices associated with the zone and its particular trip point, by one
180 * step. If the zone is 'cooling down' it brings back the performance of
181 * the devices by one step.
182 */
Sachin Kamatb88a4972012-09-27 16:28:12 +0530183static int step_wise_throttle(struct thermal_zone_device *tz, int trip)
Durgadoss Re151a202012-09-21 12:06:04 +0530184{
185 struct thermal_instance *instance;
186
187 thermal_zone_trip_update(tz, trip);
188
189 if (tz->forced_passive)
190 thermal_zone_trip_update(tz, THERMAL_TRIPS_NONE);
191
192 mutex_lock(&tz->lock);
193
194 list_for_each_entry(instance, &tz->thermal_instances, tz_node)
195 thermal_cdev_update(instance->cdev);
196
197 mutex_unlock(&tz->lock);
198
199 return 0;
200}
201
Sachin Kamatb88a4972012-09-27 16:28:12 +0530202static struct thermal_governor thermal_gov_step_wise = {
Zhang Rui1f53ef12012-12-12 15:31:37 +0800203 .name = "step_wise",
Durgadoss Re151a202012-09-21 12:06:04 +0530204 .throttle = step_wise_throttle,
Durgadoss Re151a202012-09-21 12:06:04 +0530205};
206
Zhang Rui80a26a52013-03-26 16:38:29 +0800207int thermal_gov_step_wise_register(void)
Durgadoss Re151a202012-09-21 12:06:04 +0530208{
209 return thermal_register_governor(&thermal_gov_step_wise);
210}
211
Zhang Rui80a26a52013-03-26 16:38:29 +0800212void thermal_gov_step_wise_unregister(void)
Durgadoss Re151a202012-09-21 12:06:04 +0530213{
214 thermal_unregister_governor(&thermal_gov_step_wise);
215}