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| author | Oskar Schirmer <os@emlix.com> | 2009-06-11 14:51:15 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-06-11 08:51:08 -0700 |
| commit | 8759ef32d992fc6c0bcbe40fca7aa302190918a5 (patch) | |
| tree | 316df64d3456597bf7f8ef7508654c82faf6a5fe /include/linux/rational.h | |
| parent | 9f322ad064f9210e7d472dfe77e702274d5c9dba (diff) | |
| download | linux-3.10-8759ef32d992fc6c0bcbe40fca7aa302190918a5.tar.gz linux-3.10-8759ef32d992fc6c0bcbe40fca7aa302190918a5.tar.bz2 linux-3.10-8759ef32d992fc6c0bcbe40fca7aa302190918a5.zip | |
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 <os@emlix.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/rational.h')
| -rw-r--r-- | include/linux/rational.h | 19 |
1 files changed, 19 insertions, 0 deletions
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 <os@emlix.com> + * + * 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 */ |