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