From 7d0f3fbb93cfebd7b5dc5635166e48ab998c4f82 Mon Sep 17 00:00:00 2001 From: Tero Kristo Date: Fri, 11 Jun 2021 11:45:02 +0300 Subject: lib: rational: copy the rational fraction lib routines from Linux Copy the best rational approximation calculation routines from Linux. Typical usecase for these routines is to calculate the M/N divider values for PLLs to reach a specific clock rate. This is based on linux kernel commit: "lib/math/rational.c: fix possible incorrect result from rational fractions helper" (sha1: 323dd2c3ed0641f49e89b4e420f9eef5d3d5a881) Signed-off-by: Tero Kristo Reviewed-by: Tom Rini Signed-off-by: Tero Kristo --- include/linux/rational.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) create mode 100644 include/linux/rational.h (limited to 'include/linux') diff --git a/include/linux/rational.h b/include/linux/rational.h new file mode 100644 index 00000000000..33f5f5fc3e3 --- /dev/null +++ b/include/linux/rational.h @@ -0,0 +1,20 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * rational fractions + * + * Copyright (C) 2009 emlix GmbH, Oskar Schirmer + * + * helper functions when coping with rational numbers, + * e.g. when calculating optimum numerator/denominator pairs for + * pll configuration taking into account restricted register size + */ + +#ifndef _LINUX_RATIONAL_H +#define _LINUX_RATIONAL_H + +void rational_best_approximation( + unsigned long given_numerator, unsigned long given_denominator, + unsigned long max_numerator, unsigned long max_denominator, + unsigned long *best_numerator, unsigned long *best_denominator); + +#endif /* _LINUX_RATIONAL_H */ -- cgit v1.2.3 From fc960cb6fb94c77d1245e7f39b49d7278f480d62 Mon Sep 17 00:00:00 2001 From: Tero Kristo Date: Fri, 11 Jun 2021 11:45:06 +0300 Subject: clk: fixed_rate: add API for directly registering fixed rate clocks Current driver only supports registering fixed rate clocks from DT. Add new API which makes it possible to register fixed rate clocks directly from e.g. platform specific clock drivers. Reviewed-by: Peng Fan Signed-off-by: Tero Kristo Signed-off-by: Tero Kristo --- include/linux/clk-provider.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux') diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 6fda14f5fe6..9d296f240a4 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -247,6 +247,9 @@ struct clk *clk_register_mux(struct device *dev, const char *name, void __iomem *reg, u8 shift, u8 width, u8 clk_mux_flags); +struct clk *clk_register_fixed_rate(struct device *dev, const char *name, + ulong rate); + const char *clk_hw_get_name(const struct clk *hw); ulong clk_generic_get_rate(struct clk *clk); -- cgit v1.2.3