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
28#define HZ_PER_KHZ 1000UL
29#define HZ_PER_MHZ 1000000UL
30
31#define KHZ_PER_MHZ 1000UL
32#define KHZ_PER_GHZ 1000000UL
33
34#define MILLIWATT_PER_WATT 1000UL
35#define MICROWATT_PER_MILLIWATT 1000UL
36#define MICROWATT_PER_WATT 1000000UL
37
38#define BYTES_PER_KBIT (KILO / BITS_PER_BYTE)
39#define BYTES_PER_MBIT (MEGA / BITS_PER_BYTE)
40#define BYTES_PER_GBIT (GIGA / BITS_PER_BYTE)
41
42#define ABSOLUTE_ZERO_MILLICELSIUS -273150
43
44static inline long milli_kelvin_to_millicelsius(long t)
45{
46 return t + ABSOLUTE_ZERO_MILLICELSIUS;
47}
48
49static inline long millicelsius_to_milli_kelvin(long t)
50{
51 return t - ABSOLUTE_ZERO_MILLICELSIUS;
52}
53
54#define MILLIDEGREE_PER_DEGREE 1000
55#define MILLIDEGREE_PER_DECIDEGREE 100
56
57static inline long kelvin_to_millicelsius(long t)
58{
59 return milli_kelvin_to_millicelsius(t: t * MILLIDEGREE_PER_DEGREE);
60}
61
62static inline long millicelsius_to_kelvin(long t)
63{
64 t = millicelsius_to_milli_kelvin(t);
65
66 return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DEGREE);
67}
68
69static inline long deci_kelvin_to_celsius(long t)
70{
71 t = milli_kelvin_to_millicelsius(t: t * MILLIDEGREE_PER_DECIDEGREE);
72
73 return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DEGREE);
74}
75
76static inline long celsius_to_deci_kelvin(long t)
77{
78 t = millicelsius_to_milli_kelvin(t: t * MILLIDEGREE_PER_DEGREE);
79
80 return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DECIDEGREE);
81}
82
83/**
84 * deci_kelvin_to_millicelsius_with_offset - convert Kelvin to Celsius
85 * @t: temperature value in decidegrees Kelvin
86 * @offset: difference between Kelvin and Celsius in millidegrees
87 *
88 * Return: temperature value in millidegrees Celsius
89 */
90static inline long deci_kelvin_to_millicelsius_with_offset(long t, long offset)
91{
92 return t * MILLIDEGREE_PER_DECIDEGREE - offset;
93}
94
95static inline long deci_kelvin_to_millicelsius(long t)
96{
97 return milli_kelvin_to_millicelsius(t: t * MILLIDEGREE_PER_DECIDEGREE);
98}
99
100static inline long millicelsius_to_deci_kelvin(long t)
101{
102 t = millicelsius_to_milli_kelvin(t);
103
104 return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DECIDEGREE);
105}
106
107static inline long kelvin_to_celsius(long t)
108{
109 return t + DIV_ROUND_CLOSEST(ABSOLUTE_ZERO_MILLICELSIUS,
110 MILLIDEGREE_PER_DEGREE);
111}
112
113static inline long celsius_to_kelvin(long t)
114{
115 return t - DIV_ROUND_CLOSEST(ABSOLUTE_ZERO_MILLICELSIUS,
116 MILLIDEGREE_PER_DEGREE);
117}
118
119#endif /* _LINUX_UNITS_H */
120