Linux kernel mirror (for testing)
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linux
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_UNITS_H
3#define _LINUX_UNITS_H
4
5#include <linux/bits.h>
6#include <linux/math.h>
7
8/* Metric prefixes in accordance with Système international (d'unités) */
9#define PETA 1000000000000000ULL
10#define TERA 1000000000000ULL
11#define GIGA 1000000000UL
12#define MEGA 1000000UL
13#define KILO 1000UL
14#define HECTO 100UL
15#define DECA 10UL
16#define DECI 10UL
17#define CENTI 100UL
18#define MILLI 1000UL
19#define MICRO 1000000UL
20#define NANO 1000000000UL
21#define PICO 1000000000000ULL
22#define FEMTO 1000000000000000ULL
23
24#define NANOHZ_PER_HZ 1000000000UL
25#define MICROHZ_PER_HZ 1000000UL
26#define MILLIHZ_PER_HZ 1000UL
27#define HZ_PER_KHZ 1000UL
28#define KHZ_PER_MHZ 1000UL
29#define HZ_PER_MHZ 1000000UL
30
31#define MILLIWATT_PER_WATT 1000UL
32#define MICROWATT_PER_MILLIWATT 1000UL
33#define MICROWATT_PER_WATT 1000000UL
34
35#define BYTES_PER_KBIT (KILO / BITS_PER_BYTE)
36#define BYTES_PER_MBIT (MEGA / BITS_PER_BYTE)
37#define BYTES_PER_GBIT (GIGA / BITS_PER_BYTE)
38
39#define ABSOLUTE_ZERO_MILLICELSIUS -273150
40
41static inline long milli_kelvin_to_millicelsius(long t)
42{
43 return t + ABSOLUTE_ZERO_MILLICELSIUS;
44}
45
46static inline long millicelsius_to_milli_kelvin(long t)
47{
48 return t - ABSOLUTE_ZERO_MILLICELSIUS;
49}
50
51#define MILLIDEGREE_PER_DEGREE 1000
52#define MILLIDEGREE_PER_DECIDEGREE 100
53
54static inline long kelvin_to_millicelsius(long t)
55{
56 return milli_kelvin_to_millicelsius(t * MILLIDEGREE_PER_DEGREE);
57}
58
59static inline long millicelsius_to_kelvin(long t)
60{
61 t = millicelsius_to_milli_kelvin(t);
62
63 return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DEGREE);
64}
65
66static inline long deci_kelvin_to_celsius(long t)
67{
68 t = milli_kelvin_to_millicelsius(t * MILLIDEGREE_PER_DECIDEGREE);
69
70 return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DEGREE);
71}
72
73static inline long celsius_to_deci_kelvin(long t)
74{
75 t = millicelsius_to_milli_kelvin(t * MILLIDEGREE_PER_DEGREE);
76
77 return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DECIDEGREE);
78}
79
80/**
81 * deci_kelvin_to_millicelsius_with_offset - convert Kelvin to Celsius
82 * @t: temperature value in decidegrees Kelvin
83 * @offset: difference between Kelvin and Celsius in millidegrees
84 *
85 * Return: temperature value in millidegrees Celsius
86 */
87static inline long deci_kelvin_to_millicelsius_with_offset(long t, long offset)
88{
89 return t * MILLIDEGREE_PER_DECIDEGREE - offset;
90}
91
92static inline long deci_kelvin_to_millicelsius(long t)
93{
94 return milli_kelvin_to_millicelsius(t * MILLIDEGREE_PER_DECIDEGREE);
95}
96
97static inline long millicelsius_to_deci_kelvin(long t)
98{
99 t = millicelsius_to_milli_kelvin(t);
100
101 return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DECIDEGREE);
102}
103
104static inline long kelvin_to_celsius(long t)
105{
106 return t + DIV_ROUND_CLOSEST(ABSOLUTE_ZERO_MILLICELSIUS,
107 MILLIDEGREE_PER_DEGREE);
108}
109
110static inline long celsius_to_kelvin(long t)
111{
112 return t - DIV_ROUND_CLOSEST(ABSOLUTE_ZERO_MILLICELSIUS,
113 MILLIDEGREE_PER_DEGREE);
114}
115
116#endif /* _LINUX_UNITS_H */