1 // SPDX-License-Identifier: GPL-2.0
2 /*
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
7 *
8 * Thermal trips handling
9 */
10 #include "thermal_core.h"
11
__for_each_thermal_trip(struct thermal_zone_device * tz,int (* cb)(struct thermal_trip *,void *),void * data)12 int __for_each_thermal_trip(struct thermal_zone_device *tz,
13 int (*cb)(struct thermal_trip *, void *),
14 void *data)
15 {
16 int i, ret;
17 struct thermal_trip trip;
18
19 lockdep_assert_held(&tz->lock);
20
21 for (i = 0; i < tz->num_trips; i++) {
22
23 ret = __thermal_zone_get_trip(tz, i, &trip);
24 if (ret)
25 return ret;
26
27 ret = cb(&trip, data);
28 if (ret)
29 return ret;
30 }
31
32 return 0;
33 }
34
thermal_zone_get_num_trips(struct thermal_zone_device * tz)35 int thermal_zone_get_num_trips(struct thermal_zone_device *tz)
36 {
37 return tz->num_trips;
38 }
39 EXPORT_SYMBOL_GPL(thermal_zone_get_num_trips);
40
41 /**
42 * __thermal_zone_set_trips - Computes the next trip points for the driver
43 * @tz: a pointer to a thermal zone device structure
44 *
45 * The function computes the next temperature boundaries by browsing
46 * the trip points. The result is the closer low and high trip points
47 * to the current temperature. These values are passed to the backend
48 * driver to let it set its own notification mechanism (usually an
49 * interrupt).
50 *
51 * This function must be called with tz->lock held. Both tz and tz->ops
52 * must be valid pointers.
53 *
54 * It does not return a value
55 */
__thermal_zone_set_trips(struct thermal_zone_device * tz)56 void __thermal_zone_set_trips(struct thermal_zone_device *tz)
57 {
58 struct thermal_trip trip;
59 int low = -INT_MAX, high = INT_MAX;
60 int i, ret;
61
62 lockdep_assert_held(&tz->lock);
63
64 if (!tz->ops->set_trips)
65 return;
66
67 for (i = 0; i < tz->num_trips; i++) {
68 int trip_low;
69
70 ret = __thermal_zone_get_trip(tz, i , &trip);
71 if (ret)
72 return;
73
74 trip_low = trip.temperature - trip.hysteresis;
75
76 if (trip_low < tz->temperature && trip_low > low)
77 low = trip_low;
78
79 if (trip.temperature > tz->temperature &&
80 trip.temperature < high)
81 high = trip.temperature;
82 }
83
84 /* No need to change trip points */
85 if (tz->prev_low_trip == low && tz->prev_high_trip == high)
86 return;
87
88 tz->prev_low_trip = low;
89 tz->prev_high_trip = high;
90
91 dev_dbg(&tz->device,
92 "new temperature boundaries: %d < x < %d\n", low, high);
93
94 /*
95 * Set a temperature window. When this window is left the driver
96 * must inform the thermal core via thermal_zone_device_update.
97 */
98 ret = tz->ops->set_trips(tz, low, high);
99 if (ret)
100 dev_err(&tz->device, "Failed to set trips: %d\n", ret);
101 }
102
__thermal_zone_get_trip(struct thermal_zone_device * tz,int trip_id,struct thermal_trip * trip)103 int __thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
104 struct thermal_trip *trip)
105 {
106 int ret;
107
108 if (!tz || trip_id < 0 || trip_id >= tz->num_trips || !trip)
109 return -EINVAL;
110
111 if (tz->trips) {
112 *trip = tz->trips[trip_id];
113 return 0;
114 }
115
116 if (tz->ops->get_trip_hyst) {
117 ret = tz->ops->get_trip_hyst(tz, trip_id, &trip->hysteresis);
118 if (ret)
119 return ret;
120 } else {
121 trip->hysteresis = 0;
122 }
123
124 ret = tz->ops->get_trip_temp(tz, trip_id, &trip->temperature);
125 if (ret)
126 return ret;
127
128 return tz->ops->get_trip_type(tz, trip_id, &trip->type);
129 }
130 EXPORT_SYMBOL_GPL(__thermal_zone_get_trip);
131
thermal_zone_get_trip(struct thermal_zone_device * tz,int trip_id,struct thermal_trip * trip)132 int thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
133 struct thermal_trip *trip)
134 {
135 int ret;
136
137 mutex_lock(&tz->lock);
138 ret = __thermal_zone_get_trip(tz, trip_id, trip);
139 mutex_unlock(&tz->lock);
140
141 return ret;
142 }
143 EXPORT_SYMBOL_GPL(thermal_zone_get_trip);
144
thermal_zone_set_trip(struct thermal_zone_device * tz,int trip_id,const struct thermal_trip * trip)145 int thermal_zone_set_trip(struct thermal_zone_device *tz, int trip_id,
146 const struct thermal_trip *trip)
147 {
148 struct thermal_trip t;
149 int ret;
150
151 if (!tz->ops->set_trip_temp && !tz->ops->set_trip_hyst && !tz->trips)
152 return -EINVAL;
153
154 ret = __thermal_zone_get_trip(tz, trip_id, &t);
155 if (ret)
156 return ret;
157
158 if (t.type != trip->type)
159 return -EINVAL;
160
161 if (t.temperature != trip->temperature && tz->ops->set_trip_temp) {
162 ret = tz->ops->set_trip_temp(tz, trip_id, trip->temperature);
163 if (ret)
164 return ret;
165 }
166
167 if (t.hysteresis != trip->hysteresis && tz->ops->set_trip_hyst) {
168 ret = tz->ops->set_trip_hyst(tz, trip_id, trip->hysteresis);
169 if (ret)
170 return ret;
171 }
172
173 if (tz->trips && (t.temperature != trip->temperature || t.hysteresis != trip->hysteresis))
174 tz->trips[trip_id] = *trip;
175
176 thermal_notify_tz_trip_change(tz->id, trip_id, trip->type,
177 trip->temperature, trip->hysteresis);
178
179 __thermal_zone_device_update(tz, THERMAL_TRIP_CHANGED);
180
181 return 0;
182 }
183