8ebc2efcb6
[ Upstream commit 26471d4a6cf8d5d0bd0fb55c7169de7d67cc703a ] Sometimes it's useful to have well-defined SI metric prefix to be used to self-describe the formulas or equations. List most popular ones in the units.h. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@kernel.org> Stable-dep-of: c8c37bc51451 ("i2c: designware: use casting of u64 in clock multiplication to avoid overflow") Signed-off-by: Sasha Levin <sashal@kernel.org>
105 lines
2.5 KiB
C
105 lines
2.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _LINUX_UNITS_H
|
|
#define _LINUX_UNITS_H
|
|
|
|
#include <linux/kernel.h>
|
|
|
|
/* Metric prefixes in accordance with Système international (d'unités) */
|
|
#define PETA 1000000000000000ULL
|
|
#define TERA 1000000000000ULL
|
|
#define GIGA 1000000000UL
|
|
#define MEGA 1000000UL
|
|
#define KILO 1000UL
|
|
#define HECTO 100UL
|
|
#define DECA 10UL
|
|
#define DECI 10UL
|
|
#define CENTI 100UL
|
|
#define MILLI 1000UL
|
|
#define MICRO 1000000UL
|
|
#define NANO 1000000000UL
|
|
#define PICO 1000000000000ULL
|
|
#define FEMTO 1000000000000000ULL
|
|
|
|
#define MILLIWATT_PER_WATT 1000L
|
|
#define MICROWATT_PER_MILLIWATT 1000L
|
|
#define MICROWATT_PER_WATT 1000000L
|
|
|
|
#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 */
|