// SPDX-License-Identifier: GPL-2.0
/*
* thermal_helpers.c - helper functions to handle thermal devices
*
* Copyright (C) 2016 Eduardo Valentin <[email protected]>
*
* Highly based on original thermal_core.c
* Copyright (C) 2008 Intel Corp
* Copyright (C) 2008 Zhang Rui <[email protected]>
* Copyright (C) 2008 Sujith Thomas <[email protected]>
*/
#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 bool thermal_instance_present(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 true;
}
return false;
}
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 = thermal_instance_present(tz, cdev, trip);
mutex_unlock(&cdev->lock);
mutex_unlock(&tz->lock);
return ret;
}
EXPORT_SYMBOL_GPL(thermal_trip_is_bound_to_cdev);
/**
* __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) {
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);
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