85 lines
2.0 KiB
C
85 lines
2.0 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _LINUX_UNITS_H
|
|
#define _LINUX_UNITS_H
|
|
|
|
#include <linux/kernel.h>
|
|
|
|
#define ABSOLUTE_ZERO_MILLICELSIUS -273150
|
|
|
|
static inline long milli_kelvin_to_millicelsius(long t)
|
|
{
|
|
return t + ABSOLUTE_ZERO_MILLICELSIUS;
|
|
}
|
|
|
|
static inline long millicelsius_to_milli_kelvin(long t)
|
|
{
|
|
return t - ABSOLUTE_ZERO_MILLICELSIUS;
|
|
}
|
|
|
|
#define MILLIDEGREE_PER_DEGREE 1000
|
|
#define MILLIDEGREE_PER_DECIDEGREE 100
|
|
|
|
static inline long kelvin_to_millicelsius(long t)
|
|
{
|
|
return milli_kelvin_to_millicelsius(t * MILLIDEGREE_PER_DEGREE);
|
|
}
|
|
|
|
static inline long millicelsius_to_kelvin(long t)
|
|
{
|
|
t = millicelsius_to_milli_kelvin(t);
|
|
|
|
return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DEGREE);
|
|
}
|
|
|
|
static inline long deci_kelvin_to_celsius(long t)
|
|
{
|
|
t = milli_kelvin_to_millicelsius(t * MILLIDEGREE_PER_DECIDEGREE);
|
|
|
|
return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DEGREE);
|
|
}
|
|
|
|
static inline long celsius_to_deci_kelvin(long t)
|
|
{
|
|
t = millicelsius_to_milli_kelvin(t * MILLIDEGREE_PER_DEGREE);
|
|
|
|
return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DECIDEGREE);
|
|
}
|
|
|
|
/**
|
|
* deci_kelvin_to_millicelsius_with_offset - convert Kelvin to Celsius
|
|
* @t: temperature value in decidegrees Kelvin
|
|
* @offset: difference between Kelvin and Celsius in millidegrees
|
|
*
|
|
* Return: temperature value in millidegrees Celsius
|
|
*/
|
|
static inline long deci_kelvin_to_millicelsius_with_offset(long t, long offset)
|
|
{
|
|
return t * MILLIDEGREE_PER_DECIDEGREE - offset;
|
|
}
|
|
|
|
static inline long deci_kelvin_to_millicelsius(long t)
|
|
{
|
|
return milli_kelvin_to_millicelsius(t * MILLIDEGREE_PER_DECIDEGREE);
|
|
}
|
|
|
|
static inline long millicelsius_to_deci_kelvin(long t)
|
|
{
|
|
t = millicelsius_to_milli_kelvin(t);
|
|
|
|
return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DECIDEGREE);
|
|
}
|
|
|
|
static inline long kelvin_to_celsius(long t)
|
|
{
|
|
return t + DIV_ROUND_CLOSEST(ABSOLUTE_ZERO_MILLICELSIUS,
|
|
MILLIDEGREE_PER_DEGREE);
|
|
}
|
|
|
|
static inline long celsius_to_kelvin(long t)
|
|
{
|
|
return t - DIV_ROUND_CLOSEST(ABSOLUTE_ZERO_MILLICELSIUS,
|
|
MILLIDEGREE_PER_DEGREE);
|
|
}
|
|
|
|
#endif /* _LINUX_UNITS_H */
|