From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: [patch 081/118] include/linux/units.h: add helpers for kelvin to/from Celsius conversion Date: Thu, 30 Jan 2020 22:15:28 -0800 Message-ID: <20200131061528.bT9jJO3qm%akpm@linux-foundation.org> References: <20200130221021.5f0211c56346d5485af07923@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.99]:35706 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725907AbgAaGPb (ORCPT ); Fri, 31 Jan 2020 01:15:31 -0500 In-Reply-To: <20200130221021.5f0211c56346d5485af07923@linux-foundation.org> Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: akinobu.mita@gmail.com, akpm@linux-foundation.org, amit.kucheria@verdurent.com, andy.shevchenko@gmail.com, andy@infradead.org, axboe@fb.com, daniel.lezcano@linaro.org, dvhart@infradead.org, emmanuel.grumbach@intel.com, hch@lst.de, jdelvare@suse.com, jic23@kernel.org, johannes.berg@intel.com, Jonathan.Cameron@huawei.com, kbusch@kernel.org, knaack.h@gmx.de, kvalo@codeaurora.org, lars@metafoo.de, linux-mm@kvack.org, linux@roeck-us.net, luciano.coelho@intel.com, mm-commits@vger.kernel.org, pmeerw@pmeerw.net, rui.zhang@intel.com, sagi@grimberg.me, sgruszka@redhat.com, sujith.thomas@intel.com, torvalds@linux-foundation.org From: Akinobu Mita Subject: include/linux/units.h: add helpers for kelvin to/from Celsius conversion 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 for thermal drivers. These are useful for any other drivers or subsystems, but it's odd to include just for the helpers. This adds a new that provides the equivalent inline functions for any drivers or subsystems, and switches all the users of conversion helpers in to use helpers. This patch (of 12): There are several helper macros to convert kelvin to/from Celsius in for thermal drivers. These are useful for any other drivers or subsystems, but it's odd to include just for the helpers. This adds a new that provides the equivalent inline functions for any drivers or subsystems. It is intended to replace the helpers in . Link: http://lkml.kernel.org/r/1576386975-7941-2-git-send-email-akinobu.mita@gmail.com Signed-off-by: Akinobu Mita Reviewed-by: Andy Shevchenko Cc: Sujith Thomas Cc: Darren Hart Cc: Zhang Rui Cc: Daniel Lezcano Cc: Amit Kucheria Cc: Jean Delvare Cc: Guenter Roeck Cc: Keith Busch Cc: Jens Axboe Cc: Christoph Hellwig Cc: Sagi Grimberg Cc: Kalle Valo Cc: Stanislaw Gruszka Cc: Johannes Berg Cc: Emmanuel Grumbach Cc: Luca Coelho Cc: Jonathan Cameron Cc: Hartmut Knaack Cc: Lars-Peter Clausen Cc: Peter Meerwald-Stadler Cc: Andy Shevchenko Cc: Jonathan Cameron Signed-off-by: Andrew Morton --- include/linux/units.h | 84 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 84 insertions(+) --- /dev/null +++ a/include/linux/units.h @@ -0,0 +1,84 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_UNITS_H +#define _LINUX_UNITS_H + +#include + +#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 */ _