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
12int for_each_thermal_trip(struct thermal_zone_device *tz,
13			  int (*cb)(struct thermal_trip *, void *),
14			  void *data)
15{
16	struct thermal_trip *trip;
17	int ret;
18
19	for_each_trip(tz, trip) {
20		ret = cb(trip, data);
21		if (ret)
22			return ret;
23	}
24
25	return 0;
26}
27EXPORT_SYMBOL_GPL(for_each_thermal_trip);
28
29int 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}
41EXPORT_SYMBOL_GPL(thermal_zone_for_each_trip);
42
43int thermal_zone_get_num_trips(struct thermal_zone_device *tz)
44{
45	return tz->num_trips;
46}
47EXPORT_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 */
64void __thermal_zone_set_trips(struct thermal_zone_device *tz)
65{
66	const struct thermal_trip *trip;
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(tz, trip) {
76		int trip_low;
77
78		trip_low = trip->temperature - trip->hysteresis;
79
80		if (trip_low < tz->temperature && trip_low > low)
81			low = trip_low;
82
83		if (trip->temperature > tz->temperature &&
84		    trip->temperature < high)
85			high = trip->temperature;
86	}
87
88	/* No need to change trip points */
89	if (tz->prev_low_trip == low && tz->prev_high_trip == high)
90		return;
91
92	tz->prev_low_trip = low;
93	tz->prev_high_trip = high;
94
95	dev_dbg(&tz->device,
96		"new temperature boundaries: %d < x < %d\n", low, high);
97
98	/*
99	 * Set a temperature window. When this window is left the driver
100	 * must inform the thermal core via thermal_zone_device_update.
101	 */
102	ret = tz->ops.set_trips(tz, low, high);
103	if (ret)
104		dev_err(&tz->device, "Failed to set trips: %d\n", ret);
105}
106
107int __thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
108			    struct thermal_trip *trip)
109{
110	if (!tz || trip_id < 0 || trip_id >= tz->num_trips || !trip)
111		return -EINVAL;
112
113	*trip = tz->trips[trip_id];
114	return 0;
115}
116EXPORT_SYMBOL_GPL(__thermal_zone_get_trip);
117
118int thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
119			  struct thermal_trip *trip)
120{
121	int ret;
122
123	mutex_lock(&tz->lock);
124	ret = __thermal_zone_get_trip(tz, trip_id, trip);
125	mutex_unlock(&tz->lock);
126
127	return ret;
128}
129EXPORT_SYMBOL_GPL(thermal_zone_get_trip);
130
131int thermal_zone_trip_id(const struct thermal_zone_device *tz,
132			 const struct thermal_trip *trip)
133{
134	/*
135	 * Assume the trip to be located within the bounds of the thermal
136	 * zone's trips[] table.
137	 */
138	return trip - tz->trips;
139}
140void thermal_zone_trip_updated(struct thermal_zone_device *tz,
141			       const struct thermal_trip *trip)
142{
143	thermal_notify_tz_trip_change(tz, trip);
144	__thermal_zone_device_update(tz, THERMAL_TRIP_CHANGED);
145}
146
147void thermal_zone_set_trip_temp(struct thermal_zone_device *tz,
148				struct thermal_trip *trip, int temp)
149{
150	if (trip->temperature == temp)
151		return;
152
153	trip->temperature = temp;
154	thermal_notify_tz_trip_change(tz, trip);
155}
156EXPORT_SYMBOL_GPL(thermal_zone_set_trip_temp);
157