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 int i, ret;
56
57 lockdep_assert_held(&tz->lock);
58
59 if (!tz->ops->set_trips)
60 return;
61
62 for (i = 0; i < tz->num_trips; i++) {
63 int trip_low;
64
65 ret = __thermal_zone_get_trip(tz, i , &trip);
66 if (ret)
67 return;
68
69 trip_low = trip.temperature - trip.hysteresis;
70
71 if (trip_low < tz->temperature && trip_low > low)
72 low = trip_low;
73
74 if (trip.temperature > tz->temperature &&
75 trip.temperature < high)
76 high = trip.temperature;
77 }
78
79 /* No need to change trip points */
80 if (tz->prev_low_trip == low && tz->prev_high_trip == high)
81 return;
82
83 tz->prev_low_trip = low;
84 tz->prev_high_trip = high;
85
86 dev_dbg(&tz->device,
87 "new temperature boundaries: %d < x < %d\n", low, high);
88
89 /*
90 * Set a temperature window. When this window is left the driver
91 * must inform the thermal core via thermal_zone_device_update.
92 */
93 ret = tz->ops->set_trips(tz, low, high);
94 if (ret)
95 dev_err(&tz->device, "Failed to set trips: %d\n", ret);
96 }
97
__thermal_zone_get_trip(struct thermal_zone_device * tz,int trip_id,struct thermal_trip * trip)98 int __thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
99 struct thermal_trip *trip)
100 {
101 if (!tz || !tz->trips || trip_id < 0 || trip_id >= tz->num_trips || !trip)
102 return -EINVAL;
103
104 *trip = tz->trips[trip_id];
105 return 0;
106 }
107 EXPORT_SYMBOL_GPL(__thermal_zone_get_trip);
108
thermal_zone_get_trip(struct thermal_zone_device * tz,int trip_id,struct thermal_trip * trip)109 int thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
110 struct thermal_trip *trip)
111 {
112 int ret;
113
114 mutex_lock(&tz->lock);
115 ret = __thermal_zone_get_trip(tz, trip_id, trip);
116 mutex_unlock(&tz->lock);
117
118 return ret;
119 }
120 EXPORT_SYMBOL_GPL(thermal_zone_get_trip);
121
thermal_zone_set_trip(struct thermal_zone_device * tz,int trip_id,const struct thermal_trip * trip)122 int thermal_zone_set_trip(struct thermal_zone_device *tz, int trip_id,
123 const struct thermal_trip *trip)
124 {
125 struct thermal_trip t;
126 int ret;
127
128 if (!tz->ops->set_trip_temp && !tz->ops->set_trip_hyst && !tz->trips)
129 return -EINVAL;
130
131 ret = __thermal_zone_get_trip(tz, trip_id, &t);
132 if (ret)
133 return ret;
134
135 if (t.type != trip->type)
136 return -EINVAL;
137
138 if (t.temperature != trip->temperature && tz->ops->set_trip_temp) {
139 ret = tz->ops->set_trip_temp(tz, trip_id, trip->temperature);
140 if (ret)
141 return ret;
142 }
143
144 if (t.hysteresis != trip->hysteresis && tz->ops->set_trip_hyst) {
145 ret = tz->ops->set_trip_hyst(tz, trip_id, trip->hysteresis);
146 if (ret)
147 return ret;
148 }
149
150 if (tz->trips && (t.temperature != trip->temperature || t.hysteresis != trip->hysteresis))
151 tz->trips[trip_id] = *trip;
152
153 thermal_notify_tz_trip_change(tz->id, trip_id, trip->type,
154 trip->temperature, trip->hysteresis);
155
156 __thermal_zone_device_update(tz, THERMAL_TRIP_CHANGED);
157
158 return 0;
159 }
160
thermal_zone_trip_id(struct thermal_zone_device * tz,const struct thermal_trip * trip)161 int thermal_zone_trip_id(struct thermal_zone_device *tz,
162 const struct thermal_trip *trip)
163 {
164 int i;
165
166 for (i = 0; i < tz->num_trips; i++) {
167 if (&tz->trips[i] == trip)
168 return i;
169 }
170
171 return -ENODATA;
172 }
173