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1// SPDX-License-Identifier: GPL-2.02/*3 * thermal_helpers.c - helper functions to handle thermal devices4 *5 * Copyright (C) 2016 Eduardo Valentin <edubezval@gmail.com>6 *7 * Highly based on original thermal_core.c8 * Copyright (C) 2008 Intel Corp9 * 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 ": " fmt14 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 25int 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 else36 trend = THERMAL_TREND_STABLE;37 }38 39 return trend;40}41 42static bool thermal_instance_present(struct thermal_zone_device *tz,43 struct thermal_cooling_device *cdev,44 const struct thermal_trip *trip)45{46 struct thermal_instance *ti;47 48 list_for_each_entry(ti, &tz->thermal_instances, tz_node) {49 if (ti->trip == trip && ti->cdev == cdev)50 return true;51 }52 53 return false;54}55 56bool thermal_trip_is_bound_to_cdev(struct thermal_zone_device *tz,57 const struct thermal_trip *trip,58 struct thermal_cooling_device *cdev)59{60 bool ret;61 62 mutex_lock(&tz->lock);63 mutex_lock(&cdev->lock);64 65 ret = thermal_instance_present(tz, cdev, trip);66 67 mutex_unlock(&cdev->lock);68 mutex_unlock(&tz->lock);69 70 return ret;71}72EXPORT_SYMBOL_GPL(thermal_trip_is_bound_to_cdev);73 74/**75 * __thermal_zone_get_temp() - returns the temperature of a thermal zone76 * @tz: a valid pointer to a struct thermal_zone_device77 * @temp: a valid pointer to where to store the resulting temperature.78 *79 * When a valid thermal zone reference is passed, it will fetch its80 * temperature and fill @temp.81 *82 * Both tz and tz->ops must be valid pointers when calling this function,83 * and the tz->ops.get_temp callback must be provided.84 * The function must be called under tz->lock.85 *86 * Return: On success returns 0, an error code otherwise87 */88int __thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp)89{90 const struct thermal_trip_desc *td;91 int crit_temp = INT_MAX;92 int ret = -EINVAL;93 94 lockdep_assert_held(&tz->lock);95 96 ret = tz->ops.get_temp(tz, temp);97 98 if (IS_ENABLED(CONFIG_THERMAL_EMULATION) && tz->emul_temperature) {99 for_each_trip_desc(tz, td) {100 const struct thermal_trip *trip = &td->trip;101 102 if (trip->type == THERMAL_TRIP_CRITICAL) {103 crit_temp = trip->temperature;104 break;105 }106 }107 108 /*109 * Only allow emulating a temperature when the real temperature110 * is below the critical temperature so that the emulation code111 * cannot hide critical conditions.112 */113 if (!ret && *temp < crit_temp)114 *temp = tz->emul_temperature;115 }116 117 if (ret)118 dev_dbg(&tz->device, "Failed to get temperature: %d\n", ret);119 120 return ret;121}122 123/**124 * thermal_zone_get_temp() - returns the temperature of a thermal zone125 * @tz: a valid pointer to a struct thermal_zone_device126 * @temp: a valid pointer to where to store the resulting temperature.127 *128 * When a valid thermal zone reference is passed, it will fetch its129 * temperature and fill @temp.130 *131 * Return: On success returns 0, an error code otherwise132 */133int thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp)134{135 int ret;136 137 if (IS_ERR_OR_NULL(tz))138 return -EINVAL;139 140 mutex_lock(&tz->lock);141 142 if (!tz->ops.get_temp) {143 ret = -EINVAL;144 goto unlock;145 }146 147 ret = __thermal_zone_get_temp(tz, temp);148 if (!ret && *temp <= THERMAL_TEMP_INVALID)149 ret = -ENODATA;150 151unlock:152 mutex_unlock(&tz->lock);153 154 return ret;155}156EXPORT_SYMBOL_GPL(thermal_zone_get_temp);157 158static int thermal_cdev_set_cur_state(struct thermal_cooling_device *cdev, int state)159{160 int ret;161 162 /*163 * No check is needed for the ops->set_cur_state as the164 * registering function checked the ops are correctly set165 */166 ret = cdev->ops->set_cur_state(cdev, state);167 if (ret)168 return ret;169 170 thermal_notify_cdev_state_update(cdev, state);171 thermal_cooling_device_stats_update(cdev, state);172 thermal_debug_cdev_state_update(cdev, state);173 174 return 0;175}176 177void __thermal_cdev_update(struct thermal_cooling_device *cdev)178{179 struct thermal_instance *instance;180 unsigned long target = 0;181 182 /* Make sure cdev enters the deepest cooling state */183 list_for_each_entry(instance, &cdev->thermal_instances, cdev_node) {184 if (instance->target == THERMAL_NO_TARGET)185 continue;186 if (instance->target > target)187 target = instance->target;188 }189 190 thermal_cdev_set_cur_state(cdev, target);191 192 trace_cdev_update(cdev, target);193 dev_dbg(&cdev->device, "set to state %lu\n", target);194}195 196/**197 * thermal_cdev_update - update cooling device state if needed198 * @cdev: pointer to struct thermal_cooling_device199 *200 * Update the cooling device state if there is a need.201 */202void thermal_cdev_update(struct thermal_cooling_device *cdev)203{204 mutex_lock(&cdev->lock);205 if (!cdev->updated) {206 __thermal_cdev_update(cdev);207 cdev->updated = true;208 }209 mutex_unlock(&cdev->lock);210}211 212/**213 * thermal_zone_get_slope - return the slope attribute of the thermal zone214 * @tz: thermal zone device with the slope attribute215 *216 * Return: If the thermal zone device has a slope attribute, return it, else217 * return 1.218 */219int thermal_zone_get_slope(struct thermal_zone_device *tz)220{221 if (tz && tz->tzp)222 return tz->tzp->slope;223 return 1;224}225EXPORT_SYMBOL_GPL(thermal_zone_get_slope);226 227/**228 * thermal_zone_get_offset - return the offset attribute of the thermal zone229 * @tz: thermal zone device with the offset attribute230 *231 * Return: If the thermal zone device has a offset attribute, return it, else232 * return 0.233 */234int thermal_zone_get_offset(struct thermal_zone_device *tz)235{236 if (tz && tz->tzp)237 return tz->tzp->offset;238 return 0;239}240EXPORT_SYMBOL_GPL(thermal_zone_get_offset);241