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![Akinobu Mita](/assets/img/avatar_default.png)
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/1576386975-7941-2-git-send-email-akinobu.mita@gmail.com Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Sujith Thomas <sujith.thomas@intel.com> Cc: Darren Hart <dvhart@infradead.org> Cc: Zhang Rui <rui.zhang@intel.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Amit Kucheria <amit.kucheria@verdurent.com> Cc: Jean Delvare <jdelvare@suse.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Keith Busch <kbusch@kernel.org> Cc: Jens Axboe <axboe@fb.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Sagi Grimberg <sagi@grimberg.me> Cc: Kalle Valo <kvalo@codeaurora.org> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Johannes Berg <johannes.berg@intel.com> Cc: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Cc: Luca Coelho <luciano.coelho@intel.com> Cc: Jonathan Cameron <jic23@kernel.org> Cc: Hartmut Knaack <knaack.h@gmx.de> Cc: Lars-Peter Clausen <lars@metafoo.de> Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net> Cc: Andy Shevchenko <andy@infradead.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
84 lines
2 KiB
C
84 lines
2 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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