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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 Ruibb431ba2015-10-30 16:31:47 +080066 if (!instance->initialized) {
67 if (throttle) {
68 next_target = (cur_state + 1) >= instance->upper ?
69 instance->upper :
70 ((cur_state + 1) < instance->lower ?
71 instance->lower : (cur_state + 1));
72 } else {
73 next_target = THERMAL_NO_TARGET;
74 }
75
76 return next_target;
77 }
78
Zhang Rui3dbfff32012-11-19 16:10:20 +080079 switch (trend) {
80 case THERMAL_TREND_RAISING:
Andrew Brestickere79fe642013-04-09 21:59:47 +000081 if (throttle) {
Eduardo Valentinca56caa2013-06-17 21:24:24 +080082 next_target = cur_state < instance->upper ?
Zhang Rui3dbfff32012-11-19 16:10:20 +080083 (cur_state + 1) : instance->upper;
Eduardo Valentinca56caa2013-06-17 21:24:24 +080084 if (next_target < instance->lower)
85 next_target = instance->lower;
Andrew Brestickere79fe642013-04-09 21:59:47 +000086 }
Zhang Rui3dbfff32012-11-19 16:10:20 +080087 break;
88 case THERMAL_TREND_RAISE_FULL:
89 if (throttle)
Eduardo Valentinca56caa2013-06-17 21:24:24 +080090 next_target = instance->upper;
Zhang Rui3dbfff32012-11-19 16:10:20 +080091 break;
92 case THERMAL_TREND_DROPPING:
Lukasz Majewski26bb0e92014-09-24 10:27:10 +020093 if (cur_state <= instance->lower) {
Zhang Rui3dbfff32012-11-19 16:10:20 +080094 if (!throttle)
Eduardo Valentinca56caa2013-06-17 21:24:24 +080095 next_target = THERMAL_NO_TARGET;
Andrew Brestickere79fe642013-04-09 21:59:47 +000096 } else {
Eduardo Valentinca56caa2013-06-17 21:24:24 +080097 next_target = cur_state - 1;
98 if (next_target > instance->upper)
99 next_target = instance->upper;
Andrew Brestickere79fe642013-04-09 21:59:47 +0000100 }
Zhang Rui3dbfff32012-11-19 16:10:20 +0800101 break;
102 case THERMAL_TREND_DROP_FULL:
103 if (cur_state == instance->lower) {
104 if (!throttle)
Eduardo Valentinca56caa2013-06-17 21:24:24 +0800105 next_target = THERMAL_NO_TARGET;
Zhang Rui3dbfff32012-11-19 16:10:20 +0800106 } else
Eduardo Valentinca56caa2013-06-17 21:24:24 +0800107 next_target = instance->lower;
Zhang Rui3dbfff32012-11-19 16:10:20 +0800108 break;
109 default:
110 break;
Durgadoss Re151a202012-09-21 12:06:04 +0530111 }
112
Eduardo Valentinca56caa2013-06-17 21:24:24 +0800113 return next_target;
Durgadoss Re151a202012-09-21 12:06:04 +0530114}
115
116static void update_passive_instance(struct thermal_zone_device *tz,
117 enum thermal_trip_type type, int value)
118{
119 /*
120 * If value is +1, activate a passive instance.
121 * If value is -1, deactivate a passive instance.
122 */
123 if (type == THERMAL_TRIP_PASSIVE || type == THERMAL_TRIPS_NONE)
124 tz->passive += value;
125}
126
Durgadoss Re151a202012-09-21 12:06:04 +0530127static void thermal_zone_trip_update(struct thermal_zone_device *tz, int trip)
128{
Sascha Hauer17e83512015-07-24 08:12:54 +0200129 int trip_temp;
Durgadoss Re151a202012-09-21 12:06:04 +0530130 enum thermal_trip_type trip_type;
131 enum thermal_trend trend;
Zhang Ruib8bb6cb2012-11-22 15:45:02 +0800132 struct thermal_instance *instance;
133 bool throttle = false;
134 int old_target;
Durgadoss Re151a202012-09-21 12:06:04 +0530135
136 if (trip == THERMAL_TRIPS_NONE) {
137 trip_temp = tz->forced_passive;
138 trip_type = THERMAL_TRIPS_NONE;
139 } else {
140 tz->ops->get_trip_temp(tz, trip, &trip_temp);
141 tz->ops->get_trip_type(tz, trip, &trip_type);
142 }
143
144 trend = get_tz_trend(tz, trip);
145
Punit Agrawal208cd822014-07-29 11:50:50 +0100146 if (tz->temperature >= trip_temp) {
Zhang Ruib8bb6cb2012-11-22 15:45:02 +0800147 throttle = true;
Punit Agrawal208cd822014-07-29 11:50:50 +0100148 trace_thermal_zone_trip(tz, trip, trip_type);
149 }
Zhang Ruib8bb6cb2012-11-22 15:45:02 +0800150
Sascha Hauer17e83512015-07-24 08:12:54 +0200151 dev_dbg(&tz->device, "Trip%d[type=%d,temp=%d]:trend=%d,throttle=%d\n",
Aaron Lu06475b52013-12-02 13:54:26 +0800152 trip, trip_type, trip_temp, trend, throttle);
153
Durgadoss Re151a202012-09-21 12:06:04 +0530154 mutex_lock(&tz->lock);
155
Zhang Ruib8bb6cb2012-11-22 15:45:02 +0800156 list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
157 if (instance->trip != trip)
158 continue;
159
160 old_target = instance->target;
161 instance->target = get_target_state(instance, trend, throttle);
Aaron Lu06475b52013-12-02 13:54:26 +0800162 dev_dbg(&instance->cdev->device, "old_target=%d, target=%d\n",
163 old_target, (int)instance->target);
Zhang Ruib8bb6cb2012-11-22 15:45:02 +0800164
Zhang Ruibb431ba2015-10-30 16:31:47 +0800165 if (instance->initialized && old_target == instance->target)
Shawn Guo178c2492013-06-17 21:24:23 +0800166 continue;
167
Zhang Ruib8bb6cb2012-11-22 15:45:02 +0800168 /* Activate a passive thermal instance */
169 if (old_target == THERMAL_NO_TARGET &&
170 instance->target != THERMAL_NO_TARGET)
171 update_passive_instance(tz, trip_type, 1);
172 /* Deactivate a passive thermal instance */
173 else if (old_target != THERMAL_NO_TARGET &&
174 instance->target == THERMAL_NO_TARGET)
175 update_passive_instance(tz, trip_type, -1);
176
Zhang Ruibb431ba2015-10-30 16:31:47 +0800177 instance->initialized = true;
Michele Di Giorgiod0b73062016-06-02 15:25:31 +0100178 mutex_lock(&instance->cdev->lock);
Zhang Ruib8bb6cb2012-11-22 15:45:02 +0800179 instance->cdev->updated = false; /* cdev needs update */
Michele Di Giorgiod0b73062016-06-02 15:25:31 +0100180 mutex_unlock(&instance->cdev->lock);
Zhang Ruib8bb6cb2012-11-22 15:45:02 +0800181 }
Durgadoss Re151a202012-09-21 12:06:04 +0530182
183 mutex_unlock(&tz->lock);
184}
185
186/**
Brian Norris56b613e2015-01-29 09:57:21 -0800187 * step_wise_throttle - throttles devices associated with the given zone
Durgadoss Re151a202012-09-21 12:06:04 +0530188 * @tz - thermal_zone_device
189 * @trip - the trip point
190 * @trip_type - type of the trip point
191 *
192 * Throttling Logic: This uses the trend of the thermal zone to throttle.
193 * If the thermal zone is 'heating up' this throttles all the cooling
194 * devices associated with the zone and its particular trip point, by one
195 * step. If the zone is 'cooling down' it brings back the performance of
196 * the devices by one step.
197 */
Sachin Kamatb88a4972012-09-27 16:28:12 +0530198static int step_wise_throttle(struct thermal_zone_device *tz, int trip)
Durgadoss Re151a202012-09-21 12:06:04 +0530199{
200 struct thermal_instance *instance;
201
202 thermal_zone_trip_update(tz, trip);
203
204 if (tz->forced_passive)
205 thermal_zone_trip_update(tz, THERMAL_TRIPS_NONE);
206
207 mutex_lock(&tz->lock);
208
209 list_for_each_entry(instance, &tz->thermal_instances, tz_node)
210 thermal_cdev_update(instance->cdev);
211
212 mutex_unlock(&tz->lock);
213
214 return 0;
215}
216
Sachin Kamatb88a4972012-09-27 16:28:12 +0530217static struct thermal_governor thermal_gov_step_wise = {
Zhang Rui1f53ef12012-12-12 15:31:37 +0800218 .name = "step_wise",
Durgadoss Re151a202012-09-21 12:06:04 +0530219 .throttle = step_wise_throttle,
Durgadoss Re151a202012-09-21 12:06:04 +0530220};
221
Zhang Rui80a26a52013-03-26 16:38:29 +0800222int thermal_gov_step_wise_register(void)
Durgadoss Re151a202012-09-21 12:06:04 +0530223{
224 return thermal_register_governor(&thermal_gov_step_wise);
225}
226
Zhang Rui80a26a52013-03-26 16:38:29 +0800227void thermal_gov_step_wise_unregister(void)
Durgadoss Re151a202012-09-21 12:06:04 +0530228{
229 thermal_unregister_governor(&thermal_gov_step_wise);
230}