1 /* 2 * thermal_helpers.c - helper functions to handle thermal devices 3 * 4 * Copyright (C) 2016 Eduardo Valentin <edubezval@gmail.com> 5 * 6 * Highly based on original thermal_core.c 7 * Copyright (C) 2008 Intel Corp 8 * Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com> 9 * Copyright (C) 2008 Sujith Thomas <sujith.thomas@intel.com> 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License as published by 13 * the Free Software Foundation; version 2 of the License. 14 */ 15 16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 17 18 #include <linux/sysfs.h> 19 #include <linux/device.h> 20 #include <linux/err.h> 21 #include <linux/slab.h> 22 #include <linux/string.h> 23 24 #include <trace/events/thermal.h> 25 26 #include "thermal_core.h" 27 28 int get_tz_trend(struct thermal_zone_device *tz, int trip) 29 { 30 enum thermal_trend trend; 31 32 if (tz->emul_temperature || !tz->ops->get_trend || 33 tz->ops->get_trend(tz, trip, &trend)) { 34 if (tz->temperature > tz->last_temperature) 35 trend = THERMAL_TREND_RAISING; 36 else if (tz->temperature < tz->last_temperature) 37 trend = THERMAL_TREND_DROPPING; 38 else 39 trend = THERMAL_TREND_STABLE; 40 } 41 42 return trend; 43 } 44 EXPORT_SYMBOL(get_tz_trend); 45 46 struct thermal_instance * 47 get_thermal_instance(struct thermal_zone_device *tz, 48 struct thermal_cooling_device *cdev, int trip) 49 { 50 struct thermal_instance *pos = NULL; 51 struct thermal_instance *target_instance = NULL; 52 53 mutex_lock(&tz->lock); 54 mutex_lock(&cdev->lock); 55 56 list_for_each_entry(pos, &tz->thermal_instances, tz_node) { 57 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) { 58 target_instance = pos; 59 break; 60 } 61 } 62 63 mutex_unlock(&cdev->lock); 64 mutex_unlock(&tz->lock); 65 66 return target_instance; 67 } 68 EXPORT_SYMBOL(get_thermal_instance); 69 70 /** 71 * thermal_zone_get_temp() - returns the temperature of a thermal zone 72 * @tz: a valid pointer to a struct thermal_zone_device 73 * @temp: a valid pointer to where to store the resulting temperature. 74 * 75 * When a valid thermal zone reference is passed, it will fetch its 76 * temperature and fill @temp. 77 * 78 * Return: On success returns 0, an error code otherwise 79 */ 80 int thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp) 81 { 82 int ret = -EINVAL; 83 int count; 84 int crit_temp = INT_MAX; 85 enum thermal_trip_type type; 86 87 if (!tz || IS_ERR(tz) || !tz->ops->get_temp) 88 goto exit; 89 90 mutex_lock(&tz->lock); 91 92 ret = tz->ops->get_temp(tz, temp); 93 94 if (IS_ENABLED(CONFIG_THERMAL_EMULATION) && tz->emul_temperature) { 95 for (count = 0; count < tz->trips; count++) { 96 ret = tz->ops->get_trip_type(tz, count, &type); 97 if (!ret && type == THERMAL_TRIP_CRITICAL) { 98 ret = tz->ops->get_trip_temp(tz, count, 99 &crit_temp); 100 break; 101 } 102 } 103 104 /* 105 * Only allow emulating a temperature when the real temperature 106 * is below the critical temperature so that the emulation code 107 * cannot hide critical conditions. 108 */ 109 if (!ret && *temp < crit_temp) 110 *temp = tz->emul_temperature; 111 } 112 113 mutex_unlock(&tz->lock); 114 exit: 115 return ret; 116 } 117 EXPORT_SYMBOL_GPL(thermal_zone_get_temp); 118 119 void thermal_zone_set_trips(struct thermal_zone_device *tz) 120 { 121 int low = -INT_MAX; 122 int high = INT_MAX; 123 int trip_temp, hysteresis; 124 int i, ret; 125 126 mutex_lock(&tz->lock); 127 128 if (!tz->ops->set_trips || !tz->ops->get_trip_hyst) 129 goto exit; 130 131 for (i = 0; i < tz->trips; i++) { 132 int trip_low; 133 134 tz->ops->get_trip_temp(tz, i, &trip_temp); 135 tz->ops->get_trip_hyst(tz, i, &hysteresis); 136 137 trip_low = trip_temp - hysteresis; 138 139 if (trip_low < tz->temperature && trip_low > low) 140 low = trip_low; 141 142 if (trip_temp > tz->temperature && trip_temp < high) 143 high = trip_temp; 144 } 145 146 /* No need to change trip points */ 147 if (tz->prev_low_trip == low && tz->prev_high_trip == high) 148 goto exit; 149 150 tz->prev_low_trip = low; 151 tz->prev_high_trip = high; 152 153 dev_dbg(&tz->device, 154 "new temperature boundaries: %d < x < %d\n", low, high); 155 156 /* 157 * Set a temperature window. When this window is left the driver 158 * must inform the thermal core via thermal_zone_device_update. 159 */ 160 ret = tz->ops->set_trips(tz, low, high); 161 if (ret) 162 dev_err(&tz->device, "Failed to set trips: %d\n", ret); 163 164 exit: 165 mutex_unlock(&tz->lock); 166 } 167 EXPORT_SYMBOL_GPL(thermal_zone_set_trips); 168 169 void thermal_cdev_update(struct thermal_cooling_device *cdev) 170 { 171 struct thermal_instance *instance; 172 unsigned long target = 0; 173 174 mutex_lock(&cdev->lock); 175 /* cooling device is updated*/ 176 if (cdev->updated) { 177 mutex_unlock(&cdev->lock); 178 return; 179 } 180 181 /* Make sure cdev enters the deepest cooling state */ 182 list_for_each_entry(instance, &cdev->thermal_instances, cdev_node) { 183 dev_dbg(&cdev->device, "zone%d->target=%lu\n", 184 instance->tz->id, instance->target); 185 if (instance->target == THERMAL_NO_TARGET) 186 continue; 187 if (instance->target > target) 188 target = instance->target; 189 } 190 cdev->ops->set_cur_state(cdev, target); 191 cdev->updated = true; 192 mutex_unlock(&cdev->lock); 193 trace_cdev_update(cdev, target); 194 dev_dbg(&cdev->device, "set to state %lu\n", target); 195 } 196 EXPORT_SYMBOL(thermal_cdev_update); 197 198 /** 199 * thermal_zone_get_slope - return the slope attribute of the thermal zone 200 * @tz: thermal zone device with the slope attribute 201 * 202 * Return: If the thermal zone device has a slope attribute, return it, else 203 * return 1. 204 */ 205 int thermal_zone_get_slope(struct thermal_zone_device *tz) 206 { 207 if (tz && tz->tzp) 208 return tz->tzp->slope; 209 return 1; 210 } 211 EXPORT_SYMBOL_GPL(thermal_zone_get_slope); 212 213 /** 214 * thermal_zone_get_offset - return the offset attribute of the thermal zone 215 * @tz: thermal zone device with the offset attribute 216 * 217 * Return: If the thermal zone device has a offset attribute, return it, else 218 * return 0. 219 */ 220 int thermal_zone_get_offset(struct thermal_zone_device *tz) 221 { 222 if (tz && tz->tzp) 223 return tz->tzp->offset; 224 return 0; 225 } 226 EXPORT_SYMBOL_GPL(thermal_zone_get_offset); 227