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