From 8759ef32d992fc6c0bcbe40fca7aa302190918a5 Mon Sep 17 00:00:00 2001 From: Oskar Schirmer Date: Thu, 11 Jun 2009 14:51:15 +0100 Subject: lib: isolate rational fractions helper function Provide a helper function to determine optimum numerator denominator value pairs taking into account restricted register size. Useful especially with PLL and other clock configurations. Signed-off-by: Oskar Schirmer Signed-off-by: Alan Cox Signed-off-by: Linus Torvalds --- include/linux/rational.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) create mode 100644 include/linux/rational.h (limited to 'include') diff --git a/include/linux/rational.h b/include/linux/rational.h new file mode 100644 index 00000000000..4f532fcd9ee --- /dev/null +++ b/include/linux/rational.h @@ -0,0 +1,19 @@ +/* + * 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 v1.2.3-70-g09d2