4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Akinobu Mita <akinobu.mita@xxxxxxxxx> [ Upstream commit 23331e4893614deb555c65cdf115c8a28ed32471 ] 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@xxxxxxxxx Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx> Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> Cc: Sujith Thomas <sujith.thomas@xxxxxxxxx> Cc: Darren Hart <dvhart@xxxxxxxxxxxxx> Cc: Zhang Rui <rui.zhang@xxxxxxxxx> Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> Cc: Amit Kucheria <amit.kucheria@xxxxxxxxxxxxx> Cc: Jean Delvare <jdelvare@xxxxxxxx> Cc: Guenter Roeck <linux@xxxxxxxxxxxx> Cc: Keith Busch <kbusch@xxxxxxxxxx> Cc: Jens Axboe <axboe@xxxxxx> Cc: Christoph Hellwig <hch@xxxxxx> Cc: Sagi Grimberg <sagi@xxxxxxxxxxx> Cc: Kalle Valo <kvalo@xxxxxxxxxxxxxx> Cc: Stanislaw Gruszka <sgruszka@xxxxxxxxxx> Cc: Johannes Berg <johannes.berg@xxxxxxxxx> Cc: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx> Cc: Luca Coelho <luciano.coelho@xxxxxxxxx> Cc: Jonathan Cameron <jic23@xxxxxxxxxx> Cc: Hartmut Knaack <knaack.h@xxxxxx> Cc: Lars-Peter Clausen <lars@xxxxxxxxxx> Cc: Peter Meerwald-Stadler <pmeerw@xxxxxxxxxx> Cc: Andy Shevchenko <andy@xxxxxxxxxxxxx> Cc: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Stable-dep-of: 3ef79cd14122 ("serial: sc16is7xx: set safe default SPI clock frequency") Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- include/linux/units.h | 84 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 84 insertions(+) create mode 100644 include/linux/units.h diff --git a/include/linux/units.h b/include/linux/units.h new file mode 100644 index 000000000000..aaf716364ec3 --- /dev/null +++ b/include/linux/units.h @@ -0,0 +1,84 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_UNITS_H +#define _LINUX_UNITS_H + +#include <linux/kernel.h> + +#define ABSOLUTE_ZERO_MILLICELSIUS -273150 + +static inline long milli_kelvin_to_millicelsius(long t) +{ + return t + ABSOLUTE_ZERO_MILLICELSIUS; +} + +static inline long millicelsius_to_milli_kelvin(long t) +{ + return t - ABSOLUTE_ZERO_MILLICELSIUS; +} + +#define MILLIDEGREE_PER_DEGREE 1000 +#define MILLIDEGREE_PER_DECIDEGREE 100 + +static inline long kelvin_to_millicelsius(long t) +{ + return milli_kelvin_to_millicelsius(t * MILLIDEGREE_PER_DEGREE); +} + +static inline long millicelsius_to_kelvin(long t) +{ + t = millicelsius_to_milli_kelvin(t); + + return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DEGREE); +} + +static inline long deci_kelvin_to_celsius(long t) +{ + t = milli_kelvin_to_millicelsius(t * MILLIDEGREE_PER_DECIDEGREE); + + return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DEGREE); +} + +static inline long celsius_to_deci_kelvin(long t) +{ + t = millicelsius_to_milli_kelvin(t * MILLIDEGREE_PER_DEGREE); + + return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DECIDEGREE); +} + +/** + * deci_kelvin_to_millicelsius_with_offset - convert Kelvin to Celsius + * @t: temperature value in decidegrees Kelvin + * @offset: difference between Kelvin and Celsius in millidegrees + * + * Return: temperature value in millidegrees Celsius + */ +static inline long deci_kelvin_to_millicelsius_with_offset(long t, long offset) +{ + return t * MILLIDEGREE_PER_DECIDEGREE - offset; +} + +static inline long deci_kelvin_to_millicelsius(long t) +{ + return milli_kelvin_to_millicelsius(t * MILLIDEGREE_PER_DECIDEGREE); +} + +static inline long millicelsius_to_deci_kelvin(long t) +{ + t = millicelsius_to_milli_kelvin(t); + + return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DECIDEGREE); +} + +static inline long kelvin_to_celsius(long t) +{ + return t + DIV_ROUND_CLOSEST(ABSOLUTE_ZERO_MILLICELSIUS, + MILLIDEGREE_PER_DEGREE); +} + +static inline long celsius_to_kelvin(long t) +{ + return t - DIV_ROUND_CLOSEST(ABSOLUTE_ZERO_MILLICELSIUS, + MILLIDEGREE_PER_DEGREE); +} + +#endif /* _LINUX_UNITS_H */ -- 2.43.0
