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 bool thermal_instance_present(struct thermal_zone_device *tz, 43 struct thermal_cooling_device *cdev, 44 const struct thermal_trip *trip) 45 { 46 const struct thermal_trip_desc *td = trip_to_trip_desc(trip); 47 struct thermal_instance *ti; 48 49 list_for_each_entry(ti, &td->thermal_instances, trip_node) { 50 if (ti->cdev == cdev) 51 return true; 52 } 53 54 return false; 55 } 56 57 bool thermal_trip_is_bound_to_cdev(struct thermal_zone_device *tz, 58 const struct thermal_trip *trip, 59 struct thermal_cooling_device *cdev) 60 { 61 guard(thermal_zone)(tz); 62 guard(cooling_dev)(cdev); 63 64 return thermal_instance_present(tz, cdev, trip); 65 } 66 EXPORT_SYMBOL_GPL(thermal_trip_is_bound_to_cdev); 67 68 /** 69 * __thermal_zone_get_temp() - returns the temperature of a thermal zone 70 * @tz: a valid pointer to a struct thermal_zone_device 71 * @temp: a valid pointer to where to store the resulting temperature. 72 * 73 * When a valid thermal zone reference is passed, it will fetch its 74 * temperature and fill @temp. 75 * 76 * Both tz and tz->ops must be valid pointers when calling this function, 77 * and the tz->ops.get_temp callback must be provided. 78 * The function must be called under tz->lock. 79 * 80 * Return: On success returns 0, an error code otherwise 81 */ 82 int __thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp) 83 { 84 const struct thermal_trip_desc *td; 85 int crit_temp = INT_MAX; 86 int ret = -EINVAL; 87 88 lockdep_assert_held(&tz->lock); 89 90 ret = tz->ops.get_temp(tz, temp); 91 92 if (IS_ENABLED(CONFIG_THERMAL_EMULATION) && tz->emul_temperature) { 93 for_each_trip_desc(tz, td) { 94 const struct thermal_trip *trip = &td->trip; 95 96 if (trip->type == THERMAL_TRIP_CRITICAL) { 97 crit_temp = trip->temperature; 98 break; 99 } 100 } 101 102 /* 103 * Only allow emulating a temperature when the real temperature 104 * is below the critical temperature so that the emulation code 105 * cannot hide critical conditions. 106 */ 107 if (!ret && *temp < crit_temp) 108 *temp = tz->emul_temperature; 109 } 110 111 if (ret) 112 dev_dbg(&tz->device, "Failed to get temperature: %d\n", ret); 113 114 return ret; 115 } 116 117 /** 118 * thermal_zone_get_temp() - returns the temperature of a thermal zone 119 * @tz: a valid pointer to a struct thermal_zone_device 120 * @temp: a valid pointer to where to store the resulting temperature. 121 * 122 * When a valid thermal zone reference is passed, it will fetch its 123 * temperature and fill @temp. 124 * 125 * Return: On success returns 0, an error code otherwise 126 */ 127 int thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp) 128 { 129 int ret; 130 131 if (IS_ERR_OR_NULL(tz)) 132 return -EINVAL; 133 134 guard(thermal_zone)(tz); 135 136 if (!tz->ops.get_temp) 137 return -EINVAL; 138 139 ret = __thermal_zone_get_temp(tz, temp); 140 if (!ret && *temp <= THERMAL_TEMP_INVALID) 141 return -ENODATA; 142 143 return ret; 144 } 145 EXPORT_SYMBOL_GPL(thermal_zone_get_temp); 146 147 static int thermal_cdev_set_cur_state(struct thermal_cooling_device *cdev, int state) 148 { 149 int ret; 150 151 /* 152 * No check is needed for the ops->set_cur_state as the 153 * registering function checked the ops are correctly set 154 */ 155 ret = cdev->ops->set_cur_state(cdev, state); 156 if (ret) 157 return ret; 158 159 thermal_notify_cdev_state_update(cdev, state); 160 thermal_cooling_device_stats_update(cdev, state); 161 thermal_debug_cdev_state_update(cdev, state); 162 163 return 0; 164 } 165 166 void __thermal_cdev_update(struct thermal_cooling_device *cdev) 167 { 168 struct thermal_instance *instance; 169 unsigned long target = 0; 170 171 /* Make sure cdev enters the deepest cooling state */ 172 list_for_each_entry(instance, &cdev->thermal_instances, cdev_node) { 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 guard(cooling_dev)(cdev); 194 195 if (!cdev->updated) { 196 __thermal_cdev_update(cdev); 197 cdev->updated = true; 198 } 199 } 200 201 /** 202 * thermal_cdev_update_nocheck() - Unconditionally update cooling device state 203 * @cdev: Target cooling device. 204 */ 205 void thermal_cdev_update_nocheck(struct thermal_cooling_device *cdev) 206 { 207 guard(cooling_dev)(cdev); 208 209 __thermal_cdev_update(cdev); 210 } 211 212 /** 213 * thermal_zone_get_slope - return the slope attribute of the thermal zone 214 * @tz: thermal zone device with the slope attribute 215 * 216 * Return: If the thermal zone device has a slope attribute, return it, else 217 * return 1. 218 */ 219 int thermal_zone_get_slope(struct thermal_zone_device *tz) 220 { 221 if (tz && tz->tzp) 222 return tz->tzp->slope; 223 return 1; 224 } 225 EXPORT_SYMBOL_GPL(thermal_zone_get_slope); 226 227 /** 228 * thermal_zone_get_offset - return the offset attribute of the thermal zone 229 * @tz: thermal zone device with the offset attribute 230 * 231 * Return: If the thermal zone device has a offset attribute, return it, else 232 * return 0. 233 */ 234 int thermal_zone_get_offset(struct thermal_zone_device *tz) 235 { 236 if (tz && tz->tzp) 237 return tz->tzp->offset; 238 return 0; 239 } 240 EXPORT_SYMBOL_GPL(thermal_zone_get_offset); 241