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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * thermal_helpers.c - helper functions to handle thermal devices
4 *
5 * Copyright (C) 2016 Eduardo Valentin <edubezval@gmail.com>
6 *
7 * Highly based on original thermal_core.c
8 * Copyright (C) 2008 Intel Corp
9 * Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com>
10 * Copyright (C) 2008 Sujith Thomas <sujith.thomas@intel.com>
11 */
12
13#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
15#include <linux/device.h>
16#include <linux/err.h>
17#include <linux/export.h>
18#include <linux/slab.h>
19#include <linux/string.h>
20#include <linux/sysfs.h>
21
22#include <trace/events/thermal.h>
23
24#include "thermal_core.h"
25
26int get_tz_trend(struct thermal_zone_device *tz, int trip)
27{
28 enum thermal_trend trend;
29
30 if (tz->emul_temperature || !tz->ops->get_trend ||
31 tz->ops->get_trend(tz, trip, &trend)) {
32 if (tz->temperature > tz->last_temperature)
33 trend = THERMAL_TREND_RAISING;
34 else if (tz->temperature < tz->last_temperature)
35 trend = THERMAL_TREND_DROPPING;
36 else
37 trend = THERMAL_TREND_STABLE;
38 }
39
40 return trend;
41}
42EXPORT_SYMBOL(get_tz_trend);
43
44struct thermal_instance *
45get_thermal_instance(struct thermal_zone_device *tz,
46 struct thermal_cooling_device *cdev, int trip)
47{
48 struct thermal_instance *pos = NULL;
49 struct thermal_instance *target_instance = NULL;
50
51 mutex_lock(&tz->lock);
52 mutex_lock(&cdev->lock);
53
54 list_for_each_entry(pos, &tz->thermal_instances, tz_node) {
55 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
56 target_instance = pos;
57 break;
58 }
59 }
60
61 mutex_unlock(&cdev->lock);
62 mutex_unlock(&tz->lock);
63
64 return target_instance;
65}
66EXPORT_SYMBOL(get_thermal_instance);
67
68/**
69 * thermal_zone_get_temp() - returns the temperature of a thermal zone
70 * @tz: a valid pointer to a struct thermal_zone_device
71 * @temp: a valid pointer to where to store the resulting temperature.
72 *
73 * When a valid thermal zone reference is passed, it will fetch its
74 * temperature and fill @temp.
75 *
76 * Return: On success returns 0, an error code otherwise
77 */
78int thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp)
79{
80 int ret = -EINVAL;
81 int count;
82 int crit_temp = INT_MAX;
83 enum thermal_trip_type type;
84
85 if (!tz || IS_ERR(tz) || !tz->ops->get_temp)
86 goto exit;
87
88 mutex_lock(&tz->lock);
89
90 ret = tz->ops->get_temp(tz, temp);
91
92 if (IS_ENABLED(CONFIG_THERMAL_EMULATION) && tz->emul_temperature) {
93 for (count = 0; count < tz->trips; count++) {
94 ret = tz->ops->get_trip_type(tz, count, &type);
95 if (!ret && type == THERMAL_TRIP_CRITICAL) {
96 ret = tz->ops->get_trip_temp(tz, count,
97 &crit_temp);
98 break;
99 }
100 }
101
102 /*
103 * Only allow emulating a temperature when the real temperature
104 * is below the critical temperature so that the emulation code
105 * cannot hide critical conditions.
106 */
107 if (!ret && *temp < crit_temp)
108 *temp = tz->emul_temperature;
109 }
110
111 mutex_unlock(&tz->lock);
112exit:
113 return ret;
114}
115EXPORT_SYMBOL_GPL(thermal_zone_get_temp);
116
117/**
118 * thermal_zone_set_trips - Computes the next trip points for the driver
119 * @tz: a pointer to a thermal zone device structure
120 *
121 * The function computes the next temperature boundaries by browsing
122 * the trip points. The result is the closer low and high trip points
123 * to the current temperature. These values are passed to the backend
124 * driver to let it set its own notification mechanism (usually an
125 * interrupt).
126 *
127 * It does not return a value
128 */
129void thermal_zone_set_trips(struct thermal_zone_device *tz)
130{
131 int low = -INT_MAX;
132 int high = INT_MAX;
133 int trip_temp, hysteresis;
134 int i, ret;
135
136 mutex_lock(&tz->lock);
137
138 if (!tz->ops->set_trips || !tz->ops->get_trip_hyst)
139 goto exit;
140
141 for (i = 0; i < tz->trips; i++) {
142 int trip_low;
143
144 tz->ops->get_trip_temp(tz, i, &trip_temp);
145 tz->ops->get_trip_hyst(tz, i, &hysteresis);
146
147 trip_low = trip_temp - hysteresis;
148
149 if (trip_low < tz->temperature && trip_low > low)
150 low = trip_low;
151
152 if (trip_temp > tz->temperature && trip_temp < high)
153 high = trip_temp;
154 }
155
156 /* No need to change trip points */
157 if (tz->prev_low_trip == low && tz->prev_high_trip == high)
158 goto exit;
159
160 tz->prev_low_trip = low;
161 tz->prev_high_trip = high;
162
163 dev_dbg(&tz->device,
164 "new temperature boundaries: %d < x < %d\n", low, high);
165
166 /*
167 * Set a temperature window. When this window is left the driver
168 * must inform the thermal core via thermal_zone_device_update.
169 */
170 ret = tz->ops->set_trips(tz, low, high);
171 if (ret)
172 dev_err(&tz->device, "Failed to set trips: %d\n", ret);
173
174exit:
175 mutex_unlock(&tz->lock);
176}
177
178static void thermal_cdev_set_cur_state(struct thermal_cooling_device *cdev,
179 int target)
180{
181 if (cdev->ops->set_cur_state(cdev, target))
182 return;
183
184 thermal_notify_cdev_state_update(cdev->id, target);
185 thermal_cooling_device_stats_update(cdev, target);
186}
187
188void thermal_cdev_update(struct thermal_cooling_device *cdev)
189{
190 struct thermal_instance *instance;
191 unsigned long target = 0;
192
193 mutex_lock(&cdev->lock);
194 /* cooling device is updated*/
195 if (cdev->updated) {
196 mutex_unlock(&cdev->lock);
197 return;
198 }
199
200 /* Make sure cdev enters the deepest cooling state */
201 list_for_each_entry(instance, &cdev->thermal_instances, cdev_node) {
202 dev_dbg(&cdev->device, "zone%d->target=%lu\n",
203 instance->tz->id, instance->target);
204 if (instance->target == THERMAL_NO_TARGET)
205 continue;
206 if (instance->target > target)
207 target = instance->target;
208 }
209
210 thermal_cdev_set_cur_state(cdev, target);
211
212 cdev->updated = true;
213 mutex_unlock(&cdev->lock);
214 trace_cdev_update(cdev, target);
215 dev_dbg(&cdev->device, "set to state %lu\n", target);
216}
217EXPORT_SYMBOL(thermal_cdev_update);
218
219/**
220 * thermal_zone_get_slope - return the slope attribute of the thermal zone
221 * @tz: thermal zone device with the slope attribute
222 *
223 * Return: If the thermal zone device has a slope attribute, return it, else
224 * return 1.
225 */
226int thermal_zone_get_slope(struct thermal_zone_device *tz)
227{
228 if (tz && tz->tzp)
229 return tz->tzp->slope;
230 return 1;
231}
232EXPORT_SYMBOL_GPL(thermal_zone_get_slope);
233
234/**
235 * thermal_zone_get_offset - return the offset attribute of the thermal zone
236 * @tz: thermal zone device with the offset attribute
237 *
238 * Return: If the thermal zone device has a offset attribute, return it, else
239 * return 0.
240 */
241int thermal_zone_get_offset(struct thermal_zone_device *tz)
242{
243 if (tz && tz->tzp)
244 return tz->tzp->offset;
245 return 0;
246}
247EXPORT_SYMBOL_GPL(thermal_zone_get_offset);
1/*
2 * thermal_helpers.c - helper functions to handle thermal devices
3 *
4 * Copyright (C) 2016 Eduardo Valentin <edubezval@gmail.com>
5 *
6 * Highly based on original thermal_core.c
7 * Copyright (C) 2008 Intel Corp
8 * Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com>
9 * Copyright (C) 2008 Sujith Thomas <sujith.thomas@intel.com>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; version 2 of the License.
14 */
15
16#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17
18#include <linux/sysfs.h>
19#include <linux/device.h>
20#include <linux/err.h>
21#include <linux/slab.h>
22#include <linux/string.h>
23
24#include <trace/events/thermal.h>
25
26#include "thermal_core.h"
27
28int get_tz_trend(struct thermal_zone_device *tz, int trip)
29{
30 enum thermal_trend trend;
31
32 if (tz->emul_temperature || !tz->ops->get_trend ||
33 tz->ops->get_trend(tz, trip, &trend)) {
34 if (tz->temperature > tz->last_temperature)
35 trend = THERMAL_TREND_RAISING;
36 else if (tz->temperature < tz->last_temperature)
37 trend = THERMAL_TREND_DROPPING;
38 else
39 trend = THERMAL_TREND_STABLE;
40 }
41
42 return trend;
43}
44EXPORT_SYMBOL(get_tz_trend);
45
46struct thermal_instance *
47get_thermal_instance(struct thermal_zone_device *tz,
48 struct thermal_cooling_device *cdev, int trip)
49{
50 struct thermal_instance *pos = NULL;
51 struct thermal_instance *target_instance = NULL;
52
53 mutex_lock(&tz->lock);
54 mutex_lock(&cdev->lock);
55
56 list_for_each_entry(pos, &tz->thermal_instances, tz_node) {
57 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
58 target_instance = pos;
59 break;
60 }
61 }
62
63 mutex_unlock(&cdev->lock);
64 mutex_unlock(&tz->lock);
65
66 return target_instance;
67}
68EXPORT_SYMBOL(get_thermal_instance);
69
70/**
71 * thermal_zone_get_temp() - returns the temperature of a thermal zone
72 * @tz: a valid pointer to a struct thermal_zone_device
73 * @temp: a valid pointer to where to store the resulting temperature.
74 *
75 * When a valid thermal zone reference is passed, it will fetch its
76 * temperature and fill @temp.
77 *
78 * Return: On success returns 0, an error code otherwise
79 */
80int thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp)
81{
82 int ret = -EINVAL;
83 int count;
84 int crit_temp = INT_MAX;
85 enum thermal_trip_type type;
86
87 if (!tz || IS_ERR(tz) || !tz->ops->get_temp)
88 goto exit;
89
90 mutex_lock(&tz->lock);
91
92 ret = tz->ops->get_temp(tz, temp);
93
94 if (IS_ENABLED(CONFIG_THERMAL_EMULATION) && tz->emul_temperature) {
95 for (count = 0; count < tz->trips; count++) {
96 ret = tz->ops->get_trip_type(tz, count, &type);
97 if (!ret && type == THERMAL_TRIP_CRITICAL) {
98 ret = tz->ops->get_trip_temp(tz, count,
99 &crit_temp);
100 break;
101 }
102 }
103
104 /*
105 * Only allow emulating a temperature when the real temperature
106 * is below the critical temperature so that the emulation code
107 * cannot hide critical conditions.
108 */
109 if (!ret && *temp < crit_temp)
110 *temp = tz->emul_temperature;
111 }
112
113 mutex_unlock(&tz->lock);
114exit:
115 return ret;
116}
117EXPORT_SYMBOL_GPL(thermal_zone_get_temp);
118
119void thermal_zone_set_trips(struct thermal_zone_device *tz)
120{
121 int low = -INT_MAX;
122 int high = INT_MAX;
123 int trip_temp, hysteresis;
124 int i, ret;
125
126 mutex_lock(&tz->lock);
127
128 if (!tz->ops->set_trips || !tz->ops->get_trip_hyst)
129 goto exit;
130
131 for (i = 0; i < tz->trips; i++) {
132 int trip_low;
133
134 tz->ops->get_trip_temp(tz, i, &trip_temp);
135 tz->ops->get_trip_hyst(tz, i, &hysteresis);
136
137 trip_low = trip_temp - hysteresis;
138
139 if (trip_low < tz->temperature && trip_low > low)
140 low = trip_low;
141
142 if (trip_temp > tz->temperature && trip_temp < high)
143 high = trip_temp;
144 }
145
146 /* No need to change trip points */
147 if (tz->prev_low_trip == low && tz->prev_high_trip == high)
148 goto exit;
149
150 tz->prev_low_trip = low;
151 tz->prev_high_trip = high;
152
153 dev_dbg(&tz->device,
154 "new temperature boundaries: %d < x < %d\n", low, high);
155
156 /*
157 * Set a temperature window. When this window is left the driver
158 * must inform the thermal core via thermal_zone_device_update.
159 */
160 ret = tz->ops->set_trips(tz, low, high);
161 if (ret)
162 dev_err(&tz->device, "Failed to set trips: %d\n", ret);
163
164exit:
165 mutex_unlock(&tz->lock);
166}
167EXPORT_SYMBOL_GPL(thermal_zone_set_trips);
168
169void thermal_cdev_update(struct thermal_cooling_device *cdev)
170{
171 struct thermal_instance *instance;
172 unsigned long target = 0;
173
174 mutex_lock(&cdev->lock);
175 /* cooling device is updated*/
176 if (cdev->updated) {
177 mutex_unlock(&cdev->lock);
178 return;
179 }
180
181 /* Make sure cdev enters the deepest cooling state */
182 list_for_each_entry(instance, &cdev->thermal_instances, cdev_node) {
183 dev_dbg(&cdev->device, "zone%d->target=%lu\n",
184 instance->tz->id, instance->target);
185 if (instance->target == THERMAL_NO_TARGET)
186 continue;
187 if (instance->target > target)
188 target = instance->target;
189 }
190
191 if (!cdev->ops->set_cur_state(cdev, target))
192 thermal_cooling_device_stats_update(cdev, target);
193
194 cdev->updated = true;
195 mutex_unlock(&cdev->lock);
196 trace_cdev_update(cdev, target);
197 dev_dbg(&cdev->device, "set to state %lu\n", target);
198}
199EXPORT_SYMBOL(thermal_cdev_update);
200
201/**
202 * thermal_zone_get_slope - return the slope attribute of the thermal zone
203 * @tz: thermal zone device with the slope attribute
204 *
205 * Return: If the thermal zone device has a slope attribute, return it, else
206 * return 1.
207 */
208int thermal_zone_get_slope(struct thermal_zone_device *tz)
209{
210 if (tz && tz->tzp)
211 return tz->tzp->slope;
212 return 1;
213}
214EXPORT_SYMBOL_GPL(thermal_zone_get_slope);
215
216/**
217 * thermal_zone_get_offset - return the offset attribute of the thermal zone
218 * @tz: thermal zone device with the offset attribute
219 *
220 * Return: If the thermal zone device has a offset attribute, return it, else
221 * return 0.
222 */
223int thermal_zone_get_offset(struct thermal_zone_device *tz)
224{
225 if (tz && tz->tzp)
226 return tz->tzp->offset;
227 return 0;
228}
229EXPORT_SYMBOL_GPL(thermal_zone_get_offset);