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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// 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 "thermal_core.h"
23#include "thermal_trace.h"
24
25int get_tz_trend(struct thermal_zone_device *tz, const struct thermal_trip *trip)
26{
27 enum thermal_trend trend;
28
29 if (tz->emul_temperature || !tz->ops->get_trend ||
30 tz->ops->get_trend(tz, trip, &trend)) {
31 if (tz->temperature > tz->last_temperature)
32 trend = THERMAL_TREND_RAISING;
33 else if (tz->temperature < tz->last_temperature)
34 trend = THERMAL_TREND_DROPPING;
35 else
36 trend = THERMAL_TREND_STABLE;
37 }
38
39 return trend;
40}
41
42struct thermal_instance *
43get_thermal_instance(struct thermal_zone_device *tz,
44 struct thermal_cooling_device *cdev, int trip_index)
45{
46 struct thermal_instance *pos = NULL;
47 struct thermal_instance *target_instance = NULL;
48 const struct thermal_trip *trip;
49
50 mutex_lock(&tz->lock);
51 mutex_lock(&cdev->lock);
52
53 trip = &tz->trips[trip_index];
54
55 list_for_each_entry(pos, &tz->thermal_instances, tz_node) {
56 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
57 target_instance = pos;
58 break;
59 }
60 }
61
62 mutex_unlock(&cdev->lock);
63 mutex_unlock(&tz->lock);
64
65 return target_instance;
66}
67EXPORT_SYMBOL(get_thermal_instance);
68
69/**
70 * __thermal_zone_get_temp() - returns the temperature of a thermal zone
71 * @tz: a valid pointer to a struct thermal_zone_device
72 * @temp: a valid pointer to where to store the resulting temperature.
73 *
74 * When a valid thermal zone reference is passed, it will fetch its
75 * temperature and fill @temp.
76 *
77 * Both tz and tz->ops must be valid pointers when calling this function,
78 * and the tz->ops->get_temp callback must be provided.
79 * The function must be called under tz->lock.
80 *
81 * Return: On success returns 0, an error code otherwise
82 */
83int __thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp)
84{
85 const struct thermal_trip *trip;
86 int crit_temp = INT_MAX;
87 int ret = -EINVAL;
88
89 lockdep_assert_held(&tz->lock);
90
91 ret = tz->ops->get_temp(tz, temp);
92
93 if (IS_ENABLED(CONFIG_THERMAL_EMULATION) && tz->emul_temperature) {
94 for_each_trip(tz, trip) {
95 if (trip->type == THERMAL_TRIP_CRITICAL) {
96 crit_temp = trip->temperature;
97 break;
98 }
99 }
100
101 /*
102 * Only allow emulating a temperature when the real temperature
103 * is below the critical temperature so that the emulation code
104 * cannot hide critical conditions.
105 */
106 if (!ret && *temp < crit_temp)
107 *temp = tz->emul_temperature;
108 }
109
110 if (ret)
111 dev_dbg(&tz->device, "Failed to get temperature: %d\n", ret);
112
113 return ret;
114}
115
116/**
117 * thermal_zone_get_temp() - returns the temperature of a thermal zone
118 * @tz: a valid pointer to a struct thermal_zone_device
119 * @temp: a valid pointer to where to store the resulting temperature.
120 *
121 * When a valid thermal zone reference is passed, it will fetch its
122 * temperature and fill @temp.
123 *
124 * Return: On success returns 0, an error code otherwise
125 */
126int thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp)
127{
128 int ret;
129
130 if (IS_ERR_OR_NULL(tz))
131 return -EINVAL;
132
133 mutex_lock(&tz->lock);
134
135 if (!tz->ops->get_temp) {
136 ret = -EINVAL;
137 goto unlock;
138 }
139
140 ret = __thermal_zone_get_temp(tz, temp);
141
142unlock:
143 mutex_unlock(&tz->lock);
144
145 return ret;
146}
147EXPORT_SYMBOL_GPL(thermal_zone_get_temp);
148
149static int thermal_cdev_set_cur_state(struct thermal_cooling_device *cdev, int state)
150{
151 int ret;
152
153 /*
154 * No check is needed for the ops->set_cur_state as the
155 * registering function checked the ops are correctly set
156 */
157 ret = cdev->ops->set_cur_state(cdev, state);
158 if (ret)
159 return ret;
160
161 thermal_notify_cdev_state_update(cdev, state);
162 thermal_cooling_device_stats_update(cdev, state);
163 thermal_debug_cdev_state_update(cdev, state);
164
165 return 0;
166}
167
168void __thermal_cdev_update(struct thermal_cooling_device *cdev)
169{
170 struct thermal_instance *instance;
171 unsigned long target = 0;
172
173 /* Make sure cdev enters the deepest cooling state */
174 list_for_each_entry(instance, &cdev->thermal_instances, cdev_node) {
175 dev_dbg(&cdev->device, "zone%d->target=%lu\n",
176 instance->tz->id, instance->target);
177 if (instance->target == THERMAL_NO_TARGET)
178 continue;
179 if (instance->target > target)
180 target = instance->target;
181 }
182
183 thermal_cdev_set_cur_state(cdev, target);
184
185 trace_cdev_update(cdev, target);
186 dev_dbg(&cdev->device, "set to state %lu\n", target);
187}
188
189/**
190 * thermal_cdev_update - update cooling device state if needed
191 * @cdev: pointer to struct thermal_cooling_device
192 *
193 * Update the cooling device state if there is a need.
194 */
195void thermal_cdev_update(struct thermal_cooling_device *cdev)
196{
197 mutex_lock(&cdev->lock);
198 if (!cdev->updated) {
199 __thermal_cdev_update(cdev);
200 cdev->updated = true;
201 }
202 mutex_unlock(&cdev->lock);
203}
204
205/**
206 * thermal_zone_get_slope - return the slope attribute of the thermal zone
207 * @tz: thermal zone device with the slope attribute
208 *
209 * Return: If the thermal zone device has a slope attribute, return it, else
210 * return 1.
211 */
212int thermal_zone_get_slope(struct thermal_zone_device *tz)
213{
214 if (tz && tz->tzp)
215 return tz->tzp->slope;
216 return 1;
217}
218EXPORT_SYMBOL_GPL(thermal_zone_get_slope);
219
220/**
221 * thermal_zone_get_offset - return the offset attribute of the thermal zone
222 * @tz: thermal zone device with the offset attribute
223 *
224 * Return: If the thermal zone device has a offset attribute, return it, else
225 * return 0.
226 */
227int thermal_zone_get_offset(struct thermal_zone_device *tz)
228{
229 if (tz && tz->tzp)
230 return tz->tzp->offset;
231 return 0;
232}
233EXPORT_SYMBOL_GPL(thermal_zone_get_offset);