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1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef _LINUX_UNITS_H | |
3 | #define _LINUX_UNITS_H | |
4 | ||
aa6159ab | 5 | #include <linux/math.h> |
23331e48 | 6 | |
26471d4a AS |
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 | ||
d2a4cbcb DR |
23 | #define NANOHZ_PER_HZ 1000000000UL |
24 | #define MICROHZ_PER_HZ 1000000UL | |
25 | #define MILLIHZ_PER_HZ 1000UL | |
e2c77032 DL |
26 | #define HZ_PER_KHZ 1000UL |
27 | #define KHZ_PER_MHZ 1000UL | |
28 | #define HZ_PER_MHZ 1000000UL | |
29 | ||
c9221919 DL |
30 | #define MILLIWATT_PER_WATT 1000UL |
31 | #define MICROWATT_PER_MILLIWATT 1000UL | |
32 | #define MICROWATT_PER_WATT 1000000UL | |
2ee5f8f0 | 33 | |
23331e48 AM |
34 | #define ABSOLUTE_ZERO_MILLICELSIUS -273150 |
35 | ||
36 | static inline long milli_kelvin_to_millicelsius(long t) | |
37 | { | |
38 | return t + ABSOLUTE_ZERO_MILLICELSIUS; | |
39 | } | |
40 | ||
41 | static inline long millicelsius_to_milli_kelvin(long t) | |
42 | { | |
43 | return t - ABSOLUTE_ZERO_MILLICELSIUS; | |
44 | } | |
45 | ||
46 | #define MILLIDEGREE_PER_DEGREE 1000 | |
47 | #define MILLIDEGREE_PER_DECIDEGREE 100 | |
48 | ||
49 | static inline long kelvin_to_millicelsius(long t) | |
50 | { | |
51 | return milli_kelvin_to_millicelsius(t * MILLIDEGREE_PER_DEGREE); | |
52 | } | |
53 | ||
54 | static inline long millicelsius_to_kelvin(long t) | |
55 | { | |
56 | t = millicelsius_to_milli_kelvin(t); | |
57 | ||
58 | return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DEGREE); | |
59 | } | |
60 | ||
61 | static inline long deci_kelvin_to_celsius(long t) | |
62 | { | |
63 | t = milli_kelvin_to_millicelsius(t * MILLIDEGREE_PER_DECIDEGREE); | |
64 | ||
65 | return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DEGREE); | |
66 | } | |
67 | ||
68 | static inline long celsius_to_deci_kelvin(long t) | |
69 | { | |
70 | t = millicelsius_to_milli_kelvin(t * MILLIDEGREE_PER_DEGREE); | |
71 | ||
72 | return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DECIDEGREE); | |
73 | } | |
74 | ||
75 | /** | |
76 | * deci_kelvin_to_millicelsius_with_offset - convert Kelvin to Celsius | |
77 | * @t: temperature value in decidegrees Kelvin | |
78 | * @offset: difference between Kelvin and Celsius in millidegrees | |
79 | * | |
80 | * Return: temperature value in millidegrees Celsius | |
81 | */ | |
82 | static inline long deci_kelvin_to_millicelsius_with_offset(long t, long offset) | |
83 | { | |
84 | return t * MILLIDEGREE_PER_DECIDEGREE - offset; | |
85 | } | |
86 | ||
87 | static inline long deci_kelvin_to_millicelsius(long t) | |
88 | { | |
89 | return milli_kelvin_to_millicelsius(t * MILLIDEGREE_PER_DECIDEGREE); | |
90 | } | |
91 | ||
92 | static inline long millicelsius_to_deci_kelvin(long t) | |
93 | { | |
94 | t = millicelsius_to_milli_kelvin(t); | |
95 | ||
96 | return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DECIDEGREE); | |
97 | } | |
98 | ||
99 | static inline long kelvin_to_celsius(long t) | |
100 | { | |
101 | return t + DIV_ROUND_CLOSEST(ABSOLUTE_ZERO_MILLICELSIUS, | |
102 | MILLIDEGREE_PER_DEGREE); | |
103 | } | |
104 | ||
105 | static inline long celsius_to_kelvin(long t) | |
106 | { | |
107 | return t - DIV_ROUND_CLOSEST(ABSOLUTE_ZERO_MILLICELSIUS, | |
108 | MILLIDEGREE_PER_DEGREE); | |
109 | } | |
110 | ||
111 | #endif /* _LINUX_UNITS_H */ |