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