linux-stable/include/linux/units.h
Dmitry Rokosov d2a4cbcb8b units: complement the set of Hz units
Currently, Hz units do not have milli, micro and nano Hz coefficients.
Some drivers (IIO especially) use their analogues to calculate
appropriate Hz values. This patch includes them to units.h definitions,
so they can be used from different kernel places.

Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru>
Link: https://lore.kernel.org/r/20220812165243.22177-3-ddrokosov@sberdevices.ru
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2022-08-28 16:52:28 +01:00

111 lines
2.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_UNITS_H
#define _LINUX_UNITS_H
#include <linux/math.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 NANOHZ_PER_HZ 1000000000UL
#define MICROHZ_PER_HZ 1000000UL
#define MILLIHZ_PER_HZ 1000UL
#define HZ_PER_KHZ 1000UL
#define KHZ_PER_MHZ 1000UL
#define HZ_PER_MHZ 1000000UL
#define MILLIWATT_PER_WATT 1000UL
#define MICROWATT_PER_MILLIWATT 1000UL
#define MICROWATT_PER_WATT 1000000UL
#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 */