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].trip; 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_desc *td; 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_desc(tz, td) { 95 const struct thermal_trip *trip = &td->trip; 96 97 if (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 ret = __thermal_zone_get_temp(tz, temp); 143 144 unlock: 145 mutex_unlock(&tz->lock); 146 147 return ret; 148 } 149 EXPORT_SYMBOL_GPL(thermal_zone_get_temp); 150 151 static int thermal_cdev_set_cur_state(struct thermal_cooling_device *cdev, int state) 152 { 153 int ret; 154 155 /* 156 * No check is needed for the ops->set_cur_state as the 157 * registering function checked the ops are correctly set 158 */ 159 ret = cdev->ops->set_cur_state(cdev, state); 160 if (ret) 161 return ret; 162 163 thermal_notify_cdev_state_update(cdev, state); 164 thermal_cooling_device_stats_update(cdev, state); 165 thermal_debug_cdev_state_update(cdev, state); 166 167 return 0; 168 } 169 170 void __thermal_cdev_update(struct thermal_cooling_device *cdev) 171 { 172 struct thermal_instance *instance; 173 unsigned long target = 0; 174 175 /* Make sure cdev enters the deepest cooling state */ 176 list_for_each_entry(instance, &cdev->thermal_instances, cdev_node) { 177 dev_dbg(&cdev->device, "zone%d->target=%lu\n", 178 instance->tz->id, instance->target); 179 if (instance->target == THERMAL_NO_TARGET) 180 continue; 181 if (instance->target > target) 182 target = instance->target; 183 } 184 185 thermal_cdev_set_cur_state(cdev, target); 186 187 trace_cdev_update(cdev, target); 188 dev_dbg(&cdev->device, "set to state %lu\n", target); 189 } 190 191 /** 192 * thermal_cdev_update - update cooling device state if needed 193 * @cdev: pointer to struct thermal_cooling_device 194 * 195 * Update the cooling device state if there is a need. 196 */ 197 void thermal_cdev_update(struct thermal_cooling_device *cdev) 198 { 199 mutex_lock(&cdev->lock); 200 if (!cdev->updated) { 201 __thermal_cdev_update(cdev); 202 cdev->updated = true; 203 } 204 mutex_unlock(&cdev->lock); 205 } 206 207 /** 208 * thermal_zone_get_slope - return the slope attribute of the thermal zone 209 * @tz: thermal zone device with the slope attribute 210 * 211 * Return: If the thermal zone device has a slope attribute, return it, else 212 * return 1. 213 */ 214 int thermal_zone_get_slope(struct thermal_zone_device *tz) 215 { 216 if (tz && tz->tzp) 217 return tz->tzp->slope; 218 return 1; 219 } 220 EXPORT_SYMBOL_GPL(thermal_zone_get_slope); 221 222 /** 223 * thermal_zone_get_offset - return the offset attribute of the thermal zone 224 * @tz: thermal zone device with the offset attribute 225 * 226 * Return: If the thermal zone device has a offset attribute, return it, else 227 * return 0. 228 */ 229 int thermal_zone_get_offset(struct thermal_zone_device *tz) 230 { 231 if (tz && tz->tzp) 232 return tz->tzp->offset; 233 return 0; 234 } 235 EXPORT_SYMBOL_GPL(thermal_zone_get_offset); 236