| // 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 "thermal_core.h" |
| #include "thermal_trace.h" |
| |
| int get_tz_trend(struct thermal_zone_device *tz, const struct thermal_trip *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; |
| } |
| |
| static struct thermal_instance *get_instance(struct thermal_zone_device *tz, |
| struct thermal_cooling_device *cdev, |
| const struct thermal_trip *trip) |
| { |
| struct thermal_instance *ti; |
| |
| list_for_each_entry(ti, &tz->thermal_instances, tz_node) { |
| if (ti->trip == trip && ti->cdev == cdev) |
| return ti; |
| } |
| |
| return NULL; |
| } |
| |
| bool thermal_trip_is_bound_to_cdev(struct thermal_zone_device *tz, |
| const struct thermal_trip *trip, |
| struct thermal_cooling_device *cdev) |
| { |
| bool ret; |
| |
| mutex_lock(&tz->lock); |
| mutex_lock(&cdev->lock); |
| |
| ret = !!get_instance(tz, cdev, trip); |
| |
| mutex_unlock(&cdev->lock); |
| mutex_unlock(&tz->lock); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(thermal_trip_is_bound_to_cdev); |
| |
| struct thermal_instance * |
| get_thermal_instance(struct thermal_zone_device *tz, |
| struct thermal_cooling_device *cdev, int trip_index) |
| { |
| struct thermal_instance *ti; |
| |
| mutex_lock(&tz->lock); |
| mutex_lock(&cdev->lock); |
| |
| ti = get_instance(tz, cdev, &tz->trips[trip_index].trip); |
| |
| mutex_unlock(&cdev->lock); |
| mutex_unlock(&tz->lock); |
| |
| return ti; |
| } |
| 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. |
| * |
| * Both tz and tz->ops must be valid pointers when calling this function, |
| * and the tz->ops.get_temp callback must be provided. |
| * The function must be called under tz->lock. |
| * |
| * Return: On success returns 0, an error code otherwise |
| */ |
| int __thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp) |
| { |
| const struct thermal_trip_desc *td; |
| int crit_temp = INT_MAX; |
| int ret = -EINVAL; |
| |
| lockdep_assert_held(&tz->lock); |
| |
| ret = tz->ops.get_temp(tz, temp); |
| |
| if (IS_ENABLED(CONFIG_THERMAL_EMULATION) && tz->emul_temperature) { |
| for_each_trip_desc(tz, td) { |
| const struct thermal_trip *trip = &td->trip; |
| |
| if (trip->type == THERMAL_TRIP_CRITICAL) { |
| crit_temp = trip->temperature; |
| 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; |
| } |
| |
| if (ret) |
| dev_dbg(&tz->device, "Failed to get temperature: %d\n", ret); |
| |
| 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; |
| |
| if (IS_ERR_OR_NULL(tz)) |
| return -EINVAL; |
| |
| mutex_lock(&tz->lock); |
| |
| if (!tz->ops.get_temp) { |
| ret = -EINVAL; |
| goto unlock; |
| } |
| |
| ret = __thermal_zone_get_temp(tz, temp); |
| if (!ret && *temp <= THERMAL_TEMP_INVALID) |
| ret = -ENODATA; |
| |
| unlock: |
| mutex_unlock(&tz->lock); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(thermal_zone_get_temp); |
| |
| static int thermal_cdev_set_cur_state(struct thermal_cooling_device *cdev, int state) |
| { |
| int ret; |
| |
| /* |
| * No check is needed for the ops->set_cur_state as the |
| * registering function checked the ops are correctly set |
| */ |
| ret = cdev->ops->set_cur_state(cdev, state); |
| if (ret) |
| return ret; |
| |
| thermal_notify_cdev_state_update(cdev, state); |
| thermal_cooling_device_stats_update(cdev, state); |
| thermal_debug_cdev_state_update(cdev, state); |
| |
| return 0; |
| } |
| |
| 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); |