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