From mboxrd@z Thu Jan  1 00:00:00 1970
From: linus.ml.walleij@gmail.com (Linus Walleij)
Date: Tue, 1 Sep 2009 23:48:57 +0200
Subject: [RFC/RFT 1/3] iop: clocksource support
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To: linux-arm-kernel@lists.infradead.org
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2009/9/1 Mikael Pettersson <mikpe@it.uu.se>:

> ?> Calculate this using the algorithm in arch/mips/kernel/time.c
> ?> they have a dynamically changing clocksource...
>
> The algorithm always computes the largest shift/mult pair that
> solves the equation:
>
> ? ? ? ?// 0 <= shift && shift <= 32
> ? ? ? ?u64 mult = ((u64)1E9 << shift) / hz;
> ? ? ? ?(mult >> 32) == 0
>
> Can I assume that this is to minimize precision loss?

So I think, I asked the question of how to calculate div but noone
answered IIRC, then I found the MIPS code and it contained this
clue. Ralf Baechle from the MIPS camp wrote this code so lets
ask him.

Linus Walleij