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 const struct thermal_trip *trip; 86 int crit_temp = INT_MAX; 87 int ret = -EINVAL; 88 89 lockdep_assert_held(&tz->lock); 90 91 ret = tz->ops->get_temp(tz, temp); 92 93 if (IS_ENABLED(CONFIG_THERMAL_EMULATION) && tz->emul_temperature) { 94 for_each_trip(tz, trip) { 95 if (trip->type == THERMAL_TRIP_CRITICAL) { 96 crit_temp = trip->temperature; 97 break; 98 } 99 } 100 101 /* 102 * Only allow emulating a temperature when the real temperature 103 * is below the critical temperature so that the emulation code 104 * cannot hide critical conditions. 105 */ 106 if (!ret && *temp < crit_temp) 107 *temp = tz->emul_temperature; 108 } 109 110 if (ret) 111 dev_dbg(&tz->device, "Failed to get temperature: %d\n", ret); 112 113 return ret; 114 } 115 116 /** 117 * thermal_zone_get_temp() - returns the temperature of a thermal zone 118 * @tz: a valid pointer to a struct thermal_zone_device 119 * @temp: a valid pointer to where to store the resulting temperature. 120 * 121 * When a valid thermal zone reference is passed, it will fetch its 122 * temperature and fill @temp. 123 * 124 * Return: On success returns 0, an error code otherwise 125 */ 126 int thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp) 127 { 128 int ret; 129 130 if (IS_ERR_OR_NULL(tz)) 131 return -EINVAL; 132 133 mutex_lock(&tz->lock); 134 135 if (!tz->ops->get_temp) { 136 ret = -EINVAL; 137 goto unlock; 138 } 139 140 ret = __thermal_zone_get_temp(tz, temp); 141 142 unlock: 143 mutex_unlock(&tz->lock); 144 145 return ret; 146 } 147 EXPORT_SYMBOL_GPL(thermal_zone_get_temp); 148 149 static int thermal_cdev_set_cur_state(struct thermal_cooling_device *cdev, int state) 150 { 151 int ret; 152 153 /* 154 * No check is needed for the ops->set_cur_state as the 155 * registering function checked the ops are correctly set 156 */ 157 ret = cdev->ops->set_cur_state(cdev, state); 158 if (ret) 159 return ret; 160 161 thermal_notify_cdev_state_update(cdev, state); 162 thermal_cooling_device_stats_update(cdev, state); 163 thermal_debug_cdev_state_update(cdev, state); 164 165 return 0; 166 } 167 168 void __thermal_cdev_update(struct thermal_cooling_device *cdev) 169 { 170 struct thermal_instance *instance; 171 unsigned long target = 0; 172 173 /* Make sure cdev enters the deepest cooling state */ 174 list_for_each_entry(instance, &cdev->thermal_instances, cdev_node) { 175 dev_dbg(&cdev->device, "zone%d->target=%lu\n", 176 instance->tz->id, instance->target); 177 if (instance->target == THERMAL_NO_TARGET) 178 continue; 179 if (instance->target > target) 180 target = instance->target; 181 } 182 183 thermal_cdev_set_cur_state(cdev, target); 184 185 trace_cdev_update(cdev, target); 186 dev_dbg(&cdev->device, "set to state %lu\n", target); 187 } 188 189 /** 190 * thermal_cdev_update - update cooling device state if needed 191 * @cdev: pointer to struct thermal_cooling_device 192 * 193 * Update the cooling device state if there is a need. 194 */ 195 void thermal_cdev_update(struct thermal_cooling_device *cdev) 196 { 197 mutex_lock(&cdev->lock); 198 if (!cdev->updated) { 199 __thermal_cdev_update(cdev); 200 cdev->updated = true; 201 } 202 mutex_unlock(&cdev->lock); 203 } 204 205 /** 206 * thermal_zone_get_slope - return the slope attribute of the thermal zone 207 * @tz: thermal zone device with the slope attribute 208 * 209 * Return: If the thermal zone device has a slope attribute, return it, else 210 * return 1. 211 */ 212 int thermal_zone_get_slope(struct thermal_zone_device *tz) 213 { 214 if (tz && tz->tzp) 215 return tz->tzp->slope; 216 return 1; 217 } 218 EXPORT_SYMBOL_GPL(thermal_zone_get_slope); 219 220 /** 221 * thermal_zone_get_offset - return the offset attribute of the thermal zone 222 * @tz: thermal zone device with the offset attribute 223 * 224 * Return: If the thermal zone device has a offset attribute, return it, else 225 * return 0. 226 */ 227 int thermal_zone_get_offset(struct thermal_zone_device *tz) 228 { 229 if (tz && tz->tzp) 230 return tz->tzp->offset; 231 return 0; 232 } 233 EXPORT_SYMBOL_GPL(thermal_zone_get_offset); 234