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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
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
12int for_each_thermal_trip(struct thermal_zone_device *tz,
13 int (*cb)(struct thermal_trip *, void *),
14 void *data)
15{
16 struct thermal_trip *trip;
17 int ret;
18
19 for_each_trip(tz, trip) {
20 ret = cb(trip, data);
21 if (ret)
22 return ret;
23 }
24
25 return 0;
26}
27EXPORT_SYMBOL_GPL(for_each_thermal_trip);
28
29int thermal_zone_for_each_trip(struct thermal_zone_device *tz,
30 int (*cb)(struct thermal_trip *, void *),
31 void *data)
32{
33 int ret;
34
35 mutex_lock(&tz->lock);
36 ret = for_each_thermal_trip(tz, cb, data);
37 mutex_unlock(&tz->lock);
38
39 return ret;
40}
41EXPORT_SYMBOL_GPL(thermal_zone_for_each_trip);
42
43int thermal_zone_get_num_trips(struct thermal_zone_device *tz)
44{
45 return tz->num_trips;
46}
47EXPORT_SYMBOL_GPL(thermal_zone_get_num_trips);
48
49/**
50 * __thermal_zone_set_trips - Computes the next trip points for the driver
51 * @tz: a pointer to a thermal zone device structure
52 *
53 * The function computes the next temperature boundaries by browsing
54 * the trip points. The result is the closer low and high trip points
55 * to the current temperature. These values are passed to the backend
56 * driver to let it set its own notification mechanism (usually an
57 * interrupt).
58 *
59 * This function must be called with tz->lock held. Both tz and tz->ops
60 * must be valid pointers.
61 *
62 * It does not return a value
63 */
64void __thermal_zone_set_trips(struct thermal_zone_device *tz)
65{
66 struct thermal_trip trip;
67 int low = -INT_MAX, high = INT_MAX;
68 bool same_trip = false;
69 int i, ret;
70
71 lockdep_assert_held(&tz->lock);
72
73 if (!tz->ops->set_trips)
74 return;
75
76 for (i = 0; i < tz->num_trips; i++) {
77 bool low_set = false;
78 int trip_low;
79
80 ret = __thermal_zone_get_trip(tz, i , &trip);
81 if (ret)
82 return;
83
84 trip_low = trip.temperature - trip.hysteresis;
85
86 if (trip_low < tz->temperature && trip_low > low) {
87 low = trip_low;
88 low_set = true;
89 same_trip = false;
90 }
91
92 if (trip.temperature > tz->temperature &&
93 trip.temperature < high) {
94 high = trip.temperature;
95 same_trip = low_set;
96 }
97 }
98
99 /* No need to change trip points */
100 if (tz->prev_low_trip == low && tz->prev_high_trip == high)
101 return;
102
103 /*
104 * If "high" and "low" are the same, skip the change unless this is the
105 * first time.
106 */
107 if (same_trip && (tz->prev_low_trip != -INT_MAX ||
108 tz->prev_high_trip != INT_MAX))
109 return;
110
111 tz->prev_low_trip = low;
112 tz->prev_high_trip = high;
113
114 dev_dbg(&tz->device,
115 "new temperature boundaries: %d < x < %d\n", low, high);
116
117 /*
118 * Set a temperature window. When this window is left the driver
119 * must inform the thermal core via thermal_zone_device_update.
120 */
121 ret = tz->ops->set_trips(tz, low, high);
122 if (ret)
123 dev_err(&tz->device, "Failed to set trips: %d\n", ret);
124}
125
126int __thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
127 struct thermal_trip *trip)
128{
129 if (!tz || !tz->trips || trip_id < 0 || trip_id >= tz->num_trips || !trip)
130 return -EINVAL;
131
132 *trip = tz->trips[trip_id];
133 return 0;
134}
135EXPORT_SYMBOL_GPL(__thermal_zone_get_trip);
136
137int thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
138 struct thermal_trip *trip)
139{
140 int ret;
141
142 mutex_lock(&tz->lock);
143 ret = __thermal_zone_get_trip(tz, trip_id, trip);
144 mutex_unlock(&tz->lock);
145
146 return ret;
147}
148EXPORT_SYMBOL_GPL(thermal_zone_get_trip);
149
150int thermal_zone_set_trip(struct thermal_zone_device *tz, int trip_id,
151 const struct thermal_trip *trip)
152{
153 struct thermal_trip t;
154 int ret;
155
156 if (!tz->ops->set_trip_temp && !tz->ops->set_trip_hyst && !tz->trips)
157 return -EINVAL;
158
159 ret = __thermal_zone_get_trip(tz, trip_id, &t);
160 if (ret)
161 return ret;
162
163 if (t.type != trip->type)
164 return -EINVAL;
165
166 if (t.temperature != trip->temperature && tz->ops->set_trip_temp) {
167 ret = tz->ops->set_trip_temp(tz, trip_id, trip->temperature);
168 if (ret)
169 return ret;
170 }
171
172 if (t.hysteresis != trip->hysteresis && tz->ops->set_trip_hyst) {
173 ret = tz->ops->set_trip_hyst(tz, trip_id, trip->hysteresis);
174 if (ret)
175 return ret;
176 }
177
178 if (tz->trips && (t.temperature != trip->temperature || t.hysteresis != trip->hysteresis))
179 tz->trips[trip_id] = *trip;
180
181 thermal_notify_tz_trip_change(tz->id, trip_id, trip->type,
182 trip->temperature, trip->hysteresis);
183
184 __thermal_zone_device_update(tz, THERMAL_TRIP_CHANGED);
185
186 return 0;
187}
188
189int thermal_zone_trip_id(struct thermal_zone_device *tz,
190 const struct thermal_trip *trip)
191{
192 /*
193 * Assume the trip to be located within the bounds of the thermal
194 * zone's trips[] table.
195 */
196 return trip - tz->trips;
197}