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#define MILLIWATT_PER_WATT 1000L
8#define MICROWATT_PER_MILLIWATT 1000L
9#define MICROWATT_PER_WATT 1000000L
10
11#define ABSOLUTE_ZERO_MILLICELSIUS -273150
12
13static inline long milli_kelvin_to_millicelsius(long t)
14{
15 return t + ABSOLUTE_ZERO_MILLICELSIUS;
16}
17
18static inline long millicelsius_to_milli_kelvin(long t)
19{
20 return t - ABSOLUTE_ZERO_MILLICELSIUS;
21}
22
23#define MILLIDEGREE_PER_DEGREE 1000
24#define MILLIDEGREE_PER_DECIDEGREE 100
25
26static inline long kelvin_to_millicelsius(long t)
27{
28 return milli_kelvin_to_millicelsius(t * MILLIDEGREE_PER_DEGREE);
29}
30
31static inline long millicelsius_to_kelvin(long t)
32{
33 t = millicelsius_to_milli_kelvin(t);
34
35 return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DEGREE);
36}
37
38static inline long deci_kelvin_to_celsius(long t)
39{
40 t = milli_kelvin_to_millicelsius(t * MILLIDEGREE_PER_DECIDEGREE);
41
42 return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DEGREE);
43}
44
45static inline long celsius_to_deci_kelvin(long t)
46{
47 t = millicelsius_to_milli_kelvin(t * MILLIDEGREE_PER_DEGREE);
48
49 return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DECIDEGREE);
50}
51
52/**
53 * deci_kelvin_to_millicelsius_with_offset - convert Kelvin to Celsius
54 * @t: temperature value in decidegrees Kelvin
55 * @offset: difference between Kelvin and Celsius in millidegrees
56 *
57 * Return: temperature value in millidegrees Celsius
58 */
59static inline long deci_kelvin_to_millicelsius_with_offset(long t, long offset)
60{
61 return t * MILLIDEGREE_PER_DECIDEGREE - offset;
62}
63
64static inline long deci_kelvin_to_millicelsius(long t)
65{
66 return milli_kelvin_to_millicelsius(t * MILLIDEGREE_PER_DECIDEGREE);
67}
68
69static inline long millicelsius_to_deci_kelvin(long t)
70{
71 t = millicelsius_to_milli_kelvin(t);
72
73 return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DECIDEGREE);
74}
75
76static inline long kelvin_to_celsius(long t)
77{
78 return t + DIV_ROUND_CLOSEST(ABSOLUTE_ZERO_MILLICELSIUS,
79 MILLIDEGREE_PER_DEGREE);
80}
81
82static inline long celsius_to_kelvin(long t)
83{
84 return t - DIV_ROUND_CLOSEST(ABSOLUTE_ZERO_MILLICELSIUS,
85 MILLIDEGREE_PER_DEGREE);
86}
87
88#endif /* _LINUX_UNITS_H */