Messages in this thread Patch in this message | | | From | Akinobu Mita <> | Subject | [PATCH v2 1/8] add header file for kelvin to/from Celsius conversion helpers | Date | Thu, 28 Nov 2019 23:54:32 +0900 |
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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/temperature.h> that provides the equivalent inline functions for any drivers or subsystems. It is intended to replace the helpers in <linux/thermal.h>.
Cc: Sujith Thomas <sujith.thomas@intel.com> Cc: Darren Hart <dvhart@infradead.org> Cc: Andy Shevchenko <andy@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> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> --- * v2 - add deci_kelvin_to_millicelsius_with_offset() in linux/temperature.h - stop including linux/temperature.h from linux/thermal.h
include/linux/temperature.h | 51 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) create mode 100644 include/linux/temperature.h
diff --git a/include/linux/temperature.h b/include/linux/temperature.h new file mode 100644 index 0000000..679e70a --- /dev/null +++ b/include/linux/temperature.h @@ -0,0 +1,51 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_TEMPERATURE_H +#define _LINUX_TEMPERATURE_H + +#include <linux/kernel.h> + +#define ABSOLUTE_ZERO_MILLICELSIUS -273150 + +static inline long kelvin_to_millicelsius(long t) +{ + return t * 1000 + ABSOLUTE_ZERO_MILLICELSIUS; +} + +static inline long millicelsius_to_kelvin(long t) +{ + return DIV_ROUND_CLOSEST(t - ABSOLUTE_ZERO_MILLICELSIUS, 1000); +} + +static inline long deci_kelvin_to_celsius(long t) +{ + return DIV_ROUND_CLOSEST(t * 100 + ABSOLUTE_ZERO_MILLICELSIUS, 1000); +} + +static inline long celsius_to_deci_kelvin(long t) +{ + return t * 10 - DIV_ROUND_CLOSEST(ABSOLUTE_ZERO_MILLICELSIUS, 100); +} + +/** + * 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 * 100 - offset; +} + +static inline long deci_kelvin_to_millicelsius(long t) +{ + return t * 100 + ABSOLUTE_ZERO_MILLICELSIUS; +} + +static inline long millicelsius_to_deci_kelvin(long t) +{ + return DIV_ROUND_CLOSEST(t - ABSOLUTE_ZERO_MILLICELSIUS, 100); +} + +#endif /* _LINUX_TEMPERATURE_H */ -- 2.7.4
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