1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * thermal_helpers.c - helper functions to handle thermal devices 4 * 5 * Copyright (C) 2016 Eduardo Valentin <edubezval@gmail.com> 6 * 7 * Highly based on original thermal_core.c 8 * Copyright (C) 2008 Intel Corp 9 * Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com> 10 * Copyright (C) 2008 Sujith Thomas <sujith.thomas@intel.com> 11 */ 12 13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 14 15 #include <linux/device.h> 16 #include <linux/err.h> 17 #include <linux/export.h> 18 #include <linux/slab.h> 19 #include <linux/string.h> 20 #include <linux/sysfs.h> 21 22 #include "thermal_core.h" 23 #include "thermal_trace.h" 24 25 int get_tz_trend(struct thermal_zone_device *tz, const struct thermal_trip *trip) 26 { 27 enum thermal_trend trend; 28 29 if (tz->emul_temperature || !tz->ops->get_trend || 30 tz->ops->get_trend(tz, trip, &trend)) { 31 if (tz->temperature > tz->last_temperature) 32 trend = THERMAL_TREND_RAISING; 33 else if (tz->temperature < tz->last_temperature) 34 trend = THERMAL_TREND_DROPPING; 35 else 36 trend = THERMAL_TREND_STABLE; 37 } 38 39 return trend; 40 } 41 42 struct thermal_instance * 43 get_thermal_instance(struct thermal_zone_device *tz, 44 struct thermal_cooling_device *cdev, int trip_index) 45 { 46 struct thermal_instance *pos = NULL; 47 struct thermal_instance *target_instance = NULL; 48 const struct thermal_trip *trip; 49 50 mutex_lock(&tz->lock); 51 mutex_lock(&cdev->lock); 52 53 trip = &tz->trips[trip_index]; 54 55 list_for_each_entry(pos, &tz->thermal_instances, tz_node) { 56 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) { 57 target_instance = pos; 58 break; 59 } 60 } 61 62 mutex_unlock(&cdev->lock); 63 mutex_unlock(&tz->lock); 64 65 return target_instance; 66 } 67 EXPORT_SYMBOL(get_thermal_instance); 68 69 /** 70 * __thermal_zone_get_temp() - returns the temperature of a thermal zone 71 * @tz: a valid pointer to a struct thermal_zone_device 72 * @temp: a valid pointer to where to store the resulting temperature. 73 * 74 * When a valid thermal zone reference is passed, it will fetch its 75 * temperature and fill @temp. 76 * 77 * Both tz and tz->ops must be valid pointers when calling this function, 78 * and the tz->ops->get_temp callback must be provided. 79 * The function must be called under tz->lock. 80 * 81 * Return: On success returns 0, an error code otherwise 82 */ 83 int __thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp) 84 { 85 int ret = -EINVAL; 86 int count; 87 int crit_temp = INT_MAX; 88 struct thermal_trip trip; 89 90 lockdep_assert_held(&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->num_trips; count++) { 96 ret = __thermal_zone_get_trip(tz, count, &trip); 97 if (!ret && trip.type == THERMAL_TRIP_CRITICAL) { 98 crit_temp = trip.temperature; 99 break; 100 } 101 } 102 103 /* 104 * Only allow emulating a temperature when the real temperature 105 * is below the critical temperature so that the emulation code 106 * cannot hide critical conditions. 107 */ 108 if (!ret && *temp < crit_temp) 109 *temp = tz->emul_temperature; 110 } 111 112 if (ret) 113 dev_dbg(&tz->device, "Failed to get temperature: %d\n", ret); 114 115 return ret; 116 } 117 118 /** 119 * thermal_zone_get_temp() - returns the temperature of a thermal zone 120 * @tz: a valid pointer to a struct thermal_zone_device 121 * @temp: a valid pointer to where to store the resulting temperature. 122 * 123 * When a valid thermal zone reference is passed, it will fetch its 124 * temperature and fill @temp. 125 * 126 * Return: On success returns 0, an error code otherwise 127 */ 128 int thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp) 129 { 130 int ret; 131 132 if (IS_ERR_OR_NULL(tz)) 133 return -EINVAL; 134 135 mutex_lock(&tz->lock); 136 137 if (!tz->ops->get_temp) { 138 ret = -EINVAL; 139 goto unlock; 140 } 141 142 if (device_is_registered(&tz->device)) 143 ret = __thermal_zone_get_temp(tz, temp); 144 else 145 ret = -ENODEV; 146 147 unlock: 148 mutex_unlock(&tz->lock); 149 150 return ret; 151 } 152 EXPORT_SYMBOL_GPL(thermal_zone_get_temp); 153 154 static void thermal_cdev_set_cur_state(struct thermal_cooling_device *cdev, 155 int target) 156 { 157 if (cdev->ops->set_cur_state(cdev, target)) 158 return; 159 160 thermal_notify_cdev_state_update(cdev->id, target); 161 thermal_cooling_device_stats_update(cdev, target); 162 } 163 164 void __thermal_cdev_update(struct thermal_cooling_device *cdev) 165 { 166 struct thermal_instance *instance; 167 unsigned long target = 0; 168 169 /* Make sure cdev enters the deepest cooling state */ 170 list_for_each_entry(instance, &cdev->thermal_instances, cdev_node) { 171 dev_dbg(&cdev->device, "zone%d->target=%lu\n", 172 instance->tz->id, instance->target); 173 if (instance->target == THERMAL_NO_TARGET) 174 continue; 175 if (instance->target > target) 176 target = instance->target; 177 } 178 179 thermal_cdev_set_cur_state(cdev, target); 180 181 trace_cdev_update(cdev, target); 182 dev_dbg(&cdev->device, "set to state %lu\n", target); 183 } 184 185 /** 186 * thermal_cdev_update - update cooling device state if needed 187 * @cdev: pointer to struct thermal_cooling_device 188 * 189 * Update the cooling device state if there is a need. 190 */ 191 void thermal_cdev_update(struct thermal_cooling_device *cdev) 192 { 193 mutex_lock(&cdev->lock); 194 if (!cdev->updated) { 195 __thermal_cdev_update(cdev); 196 cdev->updated = true; 197 } 198 mutex_unlock(&cdev->lock); 199 } 200 201 /** 202 * thermal_zone_get_slope - return the slope attribute of the thermal zone 203 * @tz: thermal zone device with the slope attribute 204 * 205 * Return: If the thermal zone device has a slope attribute, return it, else 206 * return 1. 207 */ 208 int thermal_zone_get_slope(struct thermal_zone_device *tz) 209 { 210 if (tz && tz->tzp) 211 return tz->tzp->slope; 212 return 1; 213 } 214 EXPORT_SYMBOL_GPL(thermal_zone_get_slope); 215 216 /** 217 * thermal_zone_get_offset - return the offset attribute of the thermal zone 218 * @tz: thermal zone device with the offset attribute 219 * 220 * Return: If the thermal zone device has a offset attribute, return it, else 221 * return 0. 222 */ 223 int thermal_zone_get_offset(struct thermal_zone_device *tz) 224 { 225 if (tz && tz->tzp) 226 return tz->tzp->offset; 227 return 0; 228 } 229 EXPORT_SYMBOL_GPL(thermal_zone_get_offset); 230