From cd705ea857fdd859a9df09e8adda4cb4c906e8a2 Mon Sep 17 00:00:00 2001 From: Michael Walle Date: Fri, 1 Apr 2022 23:40:29 +0200 Subject: lib: add generic polynomial calculation Some temperature and voltage sensors use a polynomial to convert between raw data points and actual temperature or voltage. The polynomial is usually the result of a curve fitting of the diode characteristic. The BT1 PVT hwmon driver already uses such a polynonmial calculation which is rather generic. Move it to lib/ so other drivers can reuse it. Signed-off-by: Michael Walle Reviewed-by: Guenter Roeck Link: https://lore.kernel.org/r/20220401214032.3738095-2-michael@walle.cc Signed-off-by: Guenter Roeck --- include/linux/polynomial.h | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) create mode 100644 include/linux/polynomial.h (limited to 'include') diff --git a/include/linux/polynomial.h b/include/linux/polynomial.h new file mode 100644 index 000000000000..9e074a0bb6fa --- /dev/null +++ b/include/linux/polynomial.h @@ -0,0 +1,35 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2020 BAIKAL ELECTRONICS, JSC + */ + +#ifndef _POLYNOMIAL_H +#define _POLYNOMIAL_H + +/* + * struct polynomial_term - one term descriptor of a polynomial + * @deg: degree of the term. + * @coef: multiplication factor of the term. + * @divider: distributed divider per each degree. + * @divider_leftover: divider leftover, which couldn't be redistributed. + */ +struct polynomial_term { + unsigned int deg; + long coef; + long divider; + long divider_leftover; +}; + +/* + * struct polynomial - a polynomial descriptor + * @total_divider: total data divider. + * @terms: polynomial terms, last term must have degree of 0 + */ +struct polynomial { + long total_divider; + struct polynomial_term terms[]; +}; + +long polynomial_calc(const struct polynomial *poly, long data); + +#endif -- cgit v1.2.3