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 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 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 */ 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 } 100 101 int __thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id, 102 struct thermal_trip *trip) 103 { 104 int ret; 105 106 if (!tz || trip_id < 0 || trip_id >= tz->num_trips || !trip) 107 return -EINVAL; 108 109 if (tz->trips) { 110 *trip = tz->trips[trip_id]; 111 return 0; 112 } 113 114 if (tz->ops->get_trip_hyst) { 115 ret = tz->ops->get_trip_hyst(tz, trip_id, &trip->hysteresis); 116 if (ret) 117 return ret; 118 } else { 119 trip->hysteresis = 0; 120 } 121 122 ret = tz->ops->get_trip_temp(tz, trip_id, &trip->temperature); 123 if (ret) 124 return ret; 125 126 return tz->ops->get_trip_type(tz, trip_id, &trip->type); 127 } 128 EXPORT_SYMBOL_GPL(__thermal_zone_get_trip); 129 130 int thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id, 131 struct thermal_trip *trip) 132 { 133 int ret; 134 135 mutex_lock(&tz->lock); 136 ret = __thermal_zone_get_trip(tz, trip_id, trip); 137 mutex_unlock(&tz->lock); 138 139 return ret; 140 } 141 EXPORT_SYMBOL_GPL(thermal_zone_get_trip); 142 143 int thermal_zone_set_trip(struct thermal_zone_device *tz, int trip_id, 144 const struct thermal_trip *trip) 145 { 146 struct thermal_trip t; 147 int ret; 148 149 if (!tz->ops->set_trip_temp && !tz->ops->set_trip_hyst && !tz->trips) 150 return -EINVAL; 151 152 ret = __thermal_zone_get_trip(tz, trip_id, &t); 153 if (ret) 154 return ret; 155 156 if (t.type != trip->type) 157 return -EINVAL; 158 159 if (t.temperature != trip->temperature && tz->ops->set_trip_temp) { 160 ret = tz->ops->set_trip_temp(tz, trip_id, trip->temperature); 161 if (ret) 162 return ret; 163 } 164 165 if (t.hysteresis != trip->hysteresis && tz->ops->set_trip_hyst) { 166 ret = tz->ops->set_trip_hyst(tz, trip_id, trip->hysteresis); 167 if (ret) 168 return ret; 169 } 170 171 if (tz->trips && (t.temperature != trip->temperature || t.hysteresis != trip->hysteresis)) 172 tz->trips[trip_id] = *trip; 173 174 thermal_notify_tz_trip_change(tz->id, trip_id, trip->type, 175 trip->temperature, trip->hysteresis); 176 177 __thermal_zone_device_update(tz, THERMAL_TRIP_CHANGED); 178 179 return 0; 180 } 181