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