4.19-stable review patch. If anyone has any objections, please let me know.
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From: Akinobu Mita akinobu.mita@gmail.com
[ 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@gmail... 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 Stable-dep-of: 3ef79cd14122 ("serial: sc16is7xx: set safe default SPI clock frequency") Signed-off-by: Sasha Levin sashal@kernel.org --- 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 */