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Akinobu Mita
23331e4893
Patch series "add header file for kelvin to/from Celsius conversion helpers", v4. There are several helper macros to convert kelvin to/from Celsius in <linux/thermal.h> for thermal drivers. These are useful for any other drivers or subsystems, but it's odd to include <linux/thermal.h> just for the helpers. This adds a new <linux/units.h> that provides the equivalent inline functions for any drivers or subsystems, and switches all the users of conversion helpers in <linux/thermal.h> to use <linux/units.h> helpers. This patch (of 12): There are several helper macros to convert kelvin to/from Celsius in <linux/thermal.h> for thermal drivers. These are useful for any other drivers or subsystems, but it's odd to include <linux/thermal.h> just for the helpers. This adds a new <linux/units.h> that provides the equivalent inline functions for any drivers or subsystems. It is intended to replace the helpers in <linux/thermal.h>. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Akinobu Mita <[email protected]> Reviewed-by: Andy Shevchenko <[email protected]> Cc: Sujith Thomas <[email protected]> Cc: Darren Hart <[email protected]> Cc: Zhang Rui <[email protected]> Cc: Daniel Lezcano <[email protected]> Cc: Amit Kucheria <[email protected]> Cc: Jean Delvare <[email protected]> Cc: Guenter Roeck <[email protected]> Cc: Keith Busch <[email protected]> Cc: Jens Axboe <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Sagi Grimberg <[email protected]> Cc: Kalle Valo <[email protected]> Cc: Stanislaw Gruszka <[email protected]> Cc: Johannes Berg <[email protected]> Cc: Emmanuel Grumbach <[email protected]> Cc: Luca Coelho <[email protected]> Cc: Jonathan Cameron <[email protected]> Cc: Hartmut Knaack <[email protected]> Cc: Lars-Peter Clausen <[email protected]> Cc: Peter Meerwald-Stadler <[email protected]> Cc: Andy Shevchenko <[email protected]> Cc: Jonathan Cameron <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
85 lines
2.0 KiB
C
85 lines
2.0 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_UNITS_H
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#define _LINUX_UNITS_H
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#include <linux/kernel.h>
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#define ABSOLUTE_ZERO_MILLICELSIUS -273150
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static inline long milli_kelvin_to_millicelsius(long t)
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{
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return t + ABSOLUTE_ZERO_MILLICELSIUS;
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}
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static inline long millicelsius_to_milli_kelvin(long t)
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{
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return t - ABSOLUTE_ZERO_MILLICELSIUS;
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}
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#define MILLIDEGREE_PER_DEGREE 1000
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#define MILLIDEGREE_PER_DECIDEGREE 100
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static inline long kelvin_to_millicelsius(long t)
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{
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return milli_kelvin_to_millicelsius(t * MILLIDEGREE_PER_DEGREE);
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}
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static inline long millicelsius_to_kelvin(long t)
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{
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t = millicelsius_to_milli_kelvin(t);
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return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DEGREE);
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}
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static inline long deci_kelvin_to_celsius(long t)
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{
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t = milli_kelvin_to_millicelsius(t * MILLIDEGREE_PER_DECIDEGREE);
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return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DEGREE);
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}
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static inline long celsius_to_deci_kelvin(long t)
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{
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t = millicelsius_to_milli_kelvin(t * MILLIDEGREE_PER_DEGREE);
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return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DECIDEGREE);
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}
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/**
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* deci_kelvin_to_millicelsius_with_offset - convert Kelvin to Celsius
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* @t: temperature value in decidegrees Kelvin
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* @offset: difference between Kelvin and Celsius in millidegrees
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*
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* Return: temperature value in millidegrees Celsius
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*/
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static inline long deci_kelvin_to_millicelsius_with_offset(long t, long offset)
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{
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return t * MILLIDEGREE_PER_DECIDEGREE - offset;
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}
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static inline long deci_kelvin_to_millicelsius(long t)
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{
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return milli_kelvin_to_millicelsius(t * MILLIDEGREE_PER_DECIDEGREE);
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}
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static inline long millicelsius_to_deci_kelvin(long t)
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{
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t = millicelsius_to_milli_kelvin(t);
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return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DECIDEGREE);
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}
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static inline long kelvin_to_celsius(long t)
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{
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return t + DIV_ROUND_CLOSEST(ABSOLUTE_ZERO_MILLICELSIUS,
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MILLIDEGREE_PER_DEGREE);
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}
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static inline long celsius_to_kelvin(long t)
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{
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return t - DIV_ROUND_CLOSEST(ABSOLUTE_ZERO_MILLICELSIUS,
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MILLIDEGREE_PER_DEGREE);
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}
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#endif /* _LINUX_UNITS_H */
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