// SPDX-License-Identifier: GPL-2.0 /* * thermal_helpers.c - helper functions to handle thermal devices * * Copyright (C) 2016 Eduardo Valentin * * Highly based on original thermal_core.c * Copyright (C) 2008 Intel Corp * Copyright (C) 2008 Zhang Rui * Copyright (C) 2008 Sujith Thomas */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include "thermal_core.h" int get_tz_trend(struct thermal_zone_device *tz, int trip) { enum thermal_trend trend; if (tz->emul_temperature || !tz->ops->get_trend || tz->ops->get_trend(tz, trip, &trend)) { if (tz->temperature > tz->last_temperature) trend = THERMAL_TREND_RAISING; else if (tz->temperature < tz->last_temperature) trend = THERMAL_TREND_DROPPING; else trend = THERMAL_TREND_STABLE; } return trend; } struct thermal_instance * get_thermal_instance(struct thermal_zone_device *tz, struct thermal_cooling_device *cdev, int trip) { struct thermal_instance *pos = NULL; struct thermal_instance *target_instance = NULL; mutex_lock(&tz->lock); mutex_lock(&cdev->lock); list_for_each_entry(pos, &tz->thermal_instances, tz_node) { if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) { target_instance = pos; break; } } mutex_unlock(&cdev->lock); mutex_unlock(&tz->lock); return target_instance; } EXPORT_SYMBOL(get_thermal_instance); /** * thermal_zone_get_temp() - returns the temperature of a thermal zone * @tz: a valid pointer to a struct thermal_zone_device * @temp: a valid pointer to where to store the resulting temperature. * * When a valid thermal zone reference is passed, it will fetch its * temperature and fill @temp. * * Return: On success returns 0, an error code otherwise */ int thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp) { int ret = -EINVAL; int count; int crit_temp = INT_MAX; enum thermal_trip_type type; if (!tz || IS_ERR(tz) || !tz->ops->get_temp) goto exit; mutex_lock(&tz->lock); ret = tz->ops->get_temp(tz, temp); if (IS_ENABLED(CONFIG_THERMAL_EMULATION) && tz->emul_temperature) { for (count = 0; count < tz->trips; count++) { ret = tz->ops->get_trip_type(tz, count, &type); if (!ret && type == THERMAL_TRIP_CRITICAL) { ret = tz->ops->get_trip_temp(tz, count, &crit_temp); break; } } /* * Only allow emulating a temperature when the real temperature * is below the critical temperature so that the emulation code * cannot hide critical conditions. */ if (!ret && *temp < crit_temp) *temp = tz->emul_temperature; } mutex_unlock(&tz->lock); exit: return ret; } EXPORT_SYMBOL_GPL(thermal_zone_get_temp); /** * thermal_zone_set_trips - Computes the next trip points for the driver * @tz: a pointer to a thermal zone device structure * * The function computes the next temperature boundaries by browsing * the trip points. The result is the closer low and high trip points * to the current temperature. These values are passed to the backend * driver to let it set its own notification mechanism (usually an * interrupt). * * It does not return a value */ void thermal_zone_set_trips(struct thermal_zone_device *tz) { int low = -INT_MAX; int high = INT_MAX; int trip_temp, hysteresis; int i, ret; mutex_lock(&tz->lock); if (!tz->ops->set_trips || !tz->ops->get_trip_hyst) goto exit; for (i = 0; i < tz->trips; i++) { int trip_low; tz->ops->get_trip_temp(tz, i, &trip_temp); tz->ops->get_trip_hyst(tz, i, &hysteresis); trip_low = trip_temp - hysteresis; if (trip_low < tz->temperature && trip_low > low) low = trip_low; if (trip_temp > tz->temperature && trip_temp < high) high = trip_temp; } /* No need to change trip points */ if (tz->prev_low_trip == low && tz->prev_high_trip == high) goto exit; tz->prev_low_trip = low; tz->prev_high_trip = high; dev_dbg(&tz->device, "new temperature boundaries: %d < x < %d\n", low, high); /* * Set a temperature window. When this window is left the driver * must inform the thermal core via thermal_zone_device_update. */ ret = tz->ops->set_trips(tz, low, high); if (ret) dev_err(&tz->device, "Failed to set trips: %d\n", ret); exit: mutex_unlock(&tz->lock); } static void thermal_cdev_set_cur_state(struct thermal_cooling_device *cdev, int target) { if (cdev->ops->set_cur_state(cdev, target)) return; thermal_notify_cdev_state_update(cdev->id, target); thermal_cooling_device_stats_update(cdev, target); } void __thermal_cdev_update(struct thermal_cooling_device *cdev) { struct thermal_instance *instance; unsigned long target = 0; /* Make sure cdev enters the deepest cooling state */ list_for_each_entry(instance, &cdev->thermal_instances, cdev_node) { dev_dbg(&cdev->device, "zone%d->target=%lu\n", instance->tz->id, instance->target); if (instance->target == THERMAL_NO_TARGET) continue; if (instance->target > target) target = instance->target; } thermal_cdev_set_cur_state(cdev, target); trace_cdev_update(cdev, target); dev_dbg(&cdev->device, "set to state %lu\n", target); } /** * thermal_cdev_update - update cooling device state if needed * @cdev: pointer to struct thermal_cooling_device * * Update the cooling device state if there is a need. */ void thermal_cdev_update(struct thermal_cooling_device *cdev) { mutex_lock(&cdev->lock); if (!cdev->updated) { __thermal_cdev_update(cdev); cdev->updated = true; } mutex_unlock(&cdev->lock); } /** * thermal_zone_get_slope - return the slope attribute of the thermal zone * @tz: thermal zone device with the slope attribute * * Return: If the thermal zone device has a slope attribute, return it, else * return 1. */ int thermal_zone_get_slope(struct thermal_zone_device *tz) { if (tz && tz->tzp) return tz->tzp->slope; return 1; } EXPORT_SYMBOL_GPL(thermal_zone_get_slope); /** * thermal_zone_get_offset - return the offset attribute of the thermal zone * @tz: thermal zone device with the offset attribute * * Return: If the thermal zone device has a offset attribute, return it, else * return 0. */ int thermal_zone_get_offset(struct thermal_zone_device *tz) { if (tz && tz->tzp) return tz->tzp->offset; return 0; } EXPORT_SYMBOL_GPL(thermal_zone_get_offset);