diff options
Diffstat (limited to 'drivers/thermal/thermal_helpers.c')
| -rw-r--r-- | drivers/thermal/thermal_helpers.c | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/drivers/thermal/thermal_helpers.c b/drivers/thermal/thermal_helpers.c new file mode 100644 index 000000000000..8cdf75adcce1 --- /dev/null +++ b/drivers/thermal/thermal_helpers.c @@ -0,0 +1,226 @@ +/* + * 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> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/sysfs.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/slab.h> +#include <linux/string.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; +} +EXPORT_SYMBOL(get_tz_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); + +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); +} +EXPORT_SYMBOL_GPL(thermal_zone_set_trips); + +void thermal_cdev_update(struct thermal_cooling_device *cdev) +{ + struct thermal_instance *instance; + unsigned long target = 0; + + mutex_lock(&cdev->lock); + /* cooling device is updated*/ + if (cdev->updated) { + mutex_unlock(&cdev->lock); + return; + } + + /* 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; + } + cdev->ops->set_cur_state(cdev, target); + cdev->updated = true; + mutex_unlock(&cdev->lock); + trace_cdev_update(cdev, target); + dev_dbg(&cdev->device, "set to state %lu\n", target); +} +EXPORT_SYMBOL(thermal_cdev_update); + +/** + * 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); |