| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * thermal_helpers.c - helper functions to handle thermal devices |
| * |
| * Copyright (C) 2016 Eduardo Valentin <edubezval@gmail.com> |
| * |
| * Highly based on original thermal_core.c |
| * Copyright (C) 2008 Intel Corp |
| * Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com> |
| * Copyright (C) 2008 Sujith Thomas <sujith.thomas@intel.com> |
| */ |
| |
| #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| |
| #include <linux/device.h> |
| #include <linux/err.h> |
| #include <linux/export.h> |
| #include <linux/slab.h> |
| #include <linux/string.h> |
| #include <linux/sysfs.h> |
| |
| #include <trace/events/thermal.h> |
| |
| #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); |
| |
| 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; |
| |
| lockdep_assert_held(&tz->lock); |
| |
| if (!tz || IS_ERR(tz) || !tz->ops->get_temp) |
| return -EINVAL; |
| |
| ret = tz->ops->get_temp(tz, temp); |
| |
| if (IS_ENABLED(CONFIG_THERMAL_EMULATION) && tz->emul_temperature) { |
| for (count = 0; count < tz->num_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; |
| } |
| |
| return ret; |
| } |
| |
| /** |
| * 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; |
| |
| mutex_lock(&tz->lock); |
| ret = __thermal_zone_get_temp(tz, temp); |
| mutex_unlock(&tz->lock); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(thermal_zone_get_temp); |
| |
| 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; |
| |
| lockdep_assert_held(&tz->lock); |
| |
| if (!tz->ops->set_trips || !tz->ops->get_trip_hyst) |
| return; |
| |
| for (i = 0; i < tz->num_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) |
| return; |
| |
| 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); |
| } |
| |
| /** |
| * 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) |
| { |
| mutex_lock(&tz->lock); |
| __thermal_zone_set_trips(tz); |
| 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); |