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 static struct thermal_instance *get_instance(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 ti; 51 } 52 53 return NULL; 54 } 55 56 bool 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 = !!get_instance(tz, cdev, trip); 66 67 mutex_unlock(&cdev->lock); 68 mutex_unlock(&tz->lock); 69 70 return ret; 71 } 72 EXPORT_SYMBOL_GPL(thermal_trip_is_bound_to_cdev); 73 74 struct thermal_instance * 75 get_thermal_instance(struct thermal_zone_device *tz, 76 struct thermal_cooling_device *cdev, int trip_index) 77 { 78 struct thermal_instance *ti; 79 80 mutex_lock(&tz->lock); 81 mutex_lock(&cdev->lock); 82 83 ti = get_instance(tz, cdev, &tz->trips[trip_index].trip); 84 85 mutex_unlock(&cdev->lock); 86 mutex_unlock(&tz->lock); 87 88 return ti; 89 } 90 EXPORT_SYMBOL(get_thermal_instance); 91 92 /** 93 * __thermal_zone_get_temp() - returns the temperature of a thermal zone 94 * @tz: a valid pointer to a struct thermal_zone_device 95 * @temp: a valid pointer to where to store the resulting temperature. 96 * 97 * When a valid thermal zone reference is passed, it will fetch its 98 * temperature and fill @temp. 99 * 100 * Both tz and tz->ops must be valid pointers when calling this function, 101 * and the tz->ops.get_temp callback must be provided. 102 * The function must be called under tz->lock. 103 * 104 * Return: On success returns 0, an error code otherwise 105 */ 106 int __thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp) 107 { 108 const struct thermal_trip_desc *td; 109 int crit_temp = INT_MAX; 110 int ret = -EINVAL; 111 112 lockdep_assert_held(&tz->lock); 113 114 ret = tz->ops.get_temp(tz, temp); 115 116 if (IS_ENABLED(CONFIG_THERMAL_EMULATION) && tz->emul_temperature) { 117 for_each_trip_desc(tz, td) { 118 const struct thermal_trip *trip = &td->trip; 119 120 if (trip->type == THERMAL_TRIP_CRITICAL) { 121 crit_temp = trip->temperature; 122 break; 123 } 124 } 125 126 /* 127 * Only allow emulating a temperature when the real temperature 128 * is below the critical temperature so that the emulation code 129 * cannot hide critical conditions. 130 */ 131 if (!ret && *temp < crit_temp) 132 *temp = tz->emul_temperature; 133 } 134 135 if (ret) 136 dev_dbg(&tz->device, "Failed to get temperature: %d\n", ret); 137 138 return ret; 139 } 140 141 /** 142 * thermal_zone_get_temp() - returns the temperature of a thermal zone 143 * @tz: a valid pointer to a struct thermal_zone_device 144 * @temp: a valid pointer to where to store the resulting temperature. 145 * 146 * When a valid thermal zone reference is passed, it will fetch its 147 * temperature and fill @temp. 148 * 149 * Return: On success returns 0, an error code otherwise 150 */ 151 int thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp) 152 { 153 int ret; 154 155 if (IS_ERR_OR_NULL(tz)) 156 return -EINVAL; 157 158 mutex_lock(&tz->lock); 159 160 if (!tz->ops.get_temp) { 161 ret = -EINVAL; 162 goto unlock; 163 } 164 165 ret = __thermal_zone_get_temp(tz, temp); 166 if (!ret && *temp <= THERMAL_TEMP_INVALID) 167 ret = -ENODATA; 168 169 unlock: 170 mutex_unlock(&tz->lock); 171 172 return ret; 173 } 174 EXPORT_SYMBOL_GPL(thermal_zone_get_temp); 175 176 static int thermal_cdev_set_cur_state(struct thermal_cooling_device *cdev, int state) 177 { 178 int ret; 179 180 /* 181 * No check is needed for the ops->set_cur_state as the 182 * registering function checked the ops are correctly set 183 */ 184 ret = cdev->ops->set_cur_state(cdev, state); 185 if (ret) 186 return ret; 187 188 thermal_notify_cdev_state_update(cdev, state); 189 thermal_cooling_device_stats_update(cdev, state); 190 thermal_debug_cdev_state_update(cdev, state); 191 192 return 0; 193 } 194 195 void __thermal_cdev_update(struct thermal_cooling_device *cdev) 196 { 197 struct thermal_instance *instance; 198 unsigned long target = 0; 199 200 /* Make sure cdev enters the deepest cooling state */ 201 list_for_each_entry(instance, &cdev->thermal_instances, cdev_node) { 202 dev_dbg(&cdev->device, "zone%d->target=%lu\n", 203 instance->tz->id, instance->target); 204 if (instance->target == THERMAL_NO_TARGET) 205 continue; 206 if (instance->target > target) 207 target = instance->target; 208 } 209 210 thermal_cdev_set_cur_state(cdev, target); 211 212 trace_cdev_update(cdev, target); 213 dev_dbg(&cdev->device, "set to state %lu\n", target); 214 } 215 216 /** 217 * thermal_cdev_update - update cooling device state if needed 218 * @cdev: pointer to struct thermal_cooling_device 219 * 220 * Update the cooling device state if there is a need. 221 */ 222 void thermal_cdev_update(struct thermal_cooling_device *cdev) 223 { 224 mutex_lock(&cdev->lock); 225 if (!cdev->updated) { 226 __thermal_cdev_update(cdev); 227 cdev->updated = true; 228 } 229 mutex_unlock(&cdev->lock); 230 } 231 232 /** 233 * thermal_zone_get_slope - return the slope attribute of the thermal zone 234 * @tz: thermal zone device with the slope attribute 235 * 236 * Return: If the thermal zone device has a slope attribute, return it, else 237 * return 1. 238 */ 239 int thermal_zone_get_slope(struct thermal_zone_device *tz) 240 { 241 if (tz && tz->tzp) 242 return tz->tzp->slope; 243 return 1; 244 } 245 EXPORT_SYMBOL_GPL(thermal_zone_get_slope); 246 247 /** 248 * thermal_zone_get_offset - return the offset attribute of the thermal zone 249 * @tz: thermal zone device with the offset attribute 250 * 251 * Return: If the thermal zone device has a offset attribute, return it, else 252 * return 0. 253 */ 254 int thermal_zone_get_offset(struct thermal_zone_device *tz) 255 { 256 if (tz && tz->tzp) 257 return tz->tzp->offset; 258 return 0; 259 } 260 EXPORT_SYMBOL_GPL(thermal_zone_get_offset); 261