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 struct thermal_trip_desc *td;
17 int ret;
18
19 for_each_trip_desc(tz, td) {
20 ret = cb(&td->trip, data);
21 if (ret)
22 return ret;
23 }
24
25 return 0;
26 }
27 EXPORT_SYMBOL_GPL(for_each_thermal_trip);
28
thermal_zone_for_each_trip(struct thermal_zone_device * tz,int (* cb)(struct thermal_trip *,void *),void * data)29 int 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 }
41 EXPORT_SYMBOL_GPL(thermal_zone_for_each_trip);
42
thermal_zone_get_num_trips(struct thermal_zone_device * tz)43 int thermal_zone_get_num_trips(struct thermal_zone_device *tz)
44 {
45 return tz->num_trips;
46 }
47 EXPORT_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 */
__thermal_zone_set_trips(struct thermal_zone_device * tz)64 void __thermal_zone_set_trips(struct thermal_zone_device *tz)
65 {
66 const struct thermal_trip_desc *td;
67 int low = -INT_MAX, high = INT_MAX;
68 int ret;
69
70 lockdep_assert_held(&tz->lock);
71
72 if (!tz->ops.set_trips)
73 return;
74
75 for_each_trip_desc(tz, td) {
76 const struct thermal_trip *trip = &td->trip;
77 int trip_low;
78
79 trip_low = trip->temperature - trip->hysteresis;
80
81 if (trip_low < tz->temperature && trip_low > low)
82 low = trip_low;
83
84 if (trip->temperature > tz->temperature &&
85 trip->temperature < high)
86 high = trip->temperature;
87 }
88
89 /* No need to change trip points */
90 if (tz->prev_low_trip == low && tz->prev_high_trip == high)
91 return;
92
93 tz->prev_low_trip = low;
94 tz->prev_high_trip = high;
95
96 dev_dbg(&tz->device,
97 "new temperature boundaries: %d < x < %d\n", low, high);
98
99 /*
100 * Set a temperature window. When this window is left the driver
101 * must inform the thermal core via thermal_zone_device_update.
102 */
103 ret = tz->ops.set_trips(tz, low, high);
104 if (ret)
105 dev_err(&tz->device, "Failed to set trips: %d\n", ret);
106 }
107
__thermal_zone_get_trip(struct thermal_zone_device * tz,int trip_id,struct thermal_trip * trip)108 int __thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
109 struct thermal_trip *trip)
110 {
111 if (!tz || trip_id < 0 || trip_id >= tz->num_trips || !trip)
112 return -EINVAL;
113
114 *trip = tz->trips[trip_id].trip;
115 return 0;
116 }
117 EXPORT_SYMBOL_GPL(__thermal_zone_get_trip);
118
thermal_zone_get_trip(struct thermal_zone_device * tz,int trip_id,struct thermal_trip * trip)119 int thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
120 struct thermal_trip *trip)
121 {
122 int ret;
123
124 mutex_lock(&tz->lock);
125 ret = __thermal_zone_get_trip(tz, trip_id, trip);
126 mutex_unlock(&tz->lock);
127
128 return ret;
129 }
130 EXPORT_SYMBOL_GPL(thermal_zone_get_trip);
131
thermal_zone_trip_id(const struct thermal_zone_device * tz,const struct thermal_trip * trip)132 int thermal_zone_trip_id(const struct thermal_zone_device *tz,
133 const struct thermal_trip *trip)
134 {
135 /*
136 * Assume the trip to be located within the bounds of the thermal
137 * zone's trips[] table.
138 */
139 return trip_to_trip_desc(trip) - tz->trips;
140 }
141
thermal_zone_trip_updated(struct thermal_zone_device * tz,const struct thermal_trip * trip)142 void thermal_zone_trip_updated(struct thermal_zone_device *tz,
143 const struct thermal_trip *trip)
144 {
145 thermal_notify_tz_trip_change(tz, trip);
146 __thermal_zone_device_update(tz, THERMAL_TRIP_CHANGED);
147 }
148
thermal_zone_set_trip_temp(struct thermal_zone_device * tz,struct thermal_trip * trip,int temp)149 void thermal_zone_set_trip_temp(struct thermal_zone_device *tz,
150 struct thermal_trip *trip, int temp)
151 {
152 if (trip->temperature == temp)
153 return;
154
155 trip->temperature = temp;
156 thermal_notify_tz_trip_change(tz, trip);
157
158 if (temp == THERMAL_TEMP_INVALID) {
159 struct thermal_trip_desc *td = trip_to_trip_desc(trip);
160
161 if (tz->temperature >= td->threshold) {
162 /*
163 * The trip has been crossed on the way up, so some
164 * adjustments are needed to compensate for the lack
165 * of it going forward.
166 */
167 if (trip->type == THERMAL_TRIP_PASSIVE) {
168 tz->passive--;
169 WARN_ON_ONCE(tz->passive < 0);
170 }
171 thermal_zone_trip_down(tz, trip);
172 }
173 /*
174 * Invalidate the threshold to avoid triggering a spurious
175 * trip crossing notification when the trip becomes valid.
176 */
177 td->threshold = INT_MAX;
178 }
179 }
180 EXPORT_SYMBOL_GPL(thermal_zone_set_trip_temp);
181