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https://github.com/AsahiLinux/u-boot
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58 lines
1.6 KiB
C
58 lines
1.6 KiB
C
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/*
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* Copyright 2011 Linaro Limited
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* Aneesh V <aneesh@ti.com>
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*
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* See file CREDITS for list of people who contributed to this
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* project.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
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* MA 02111-1307 USA
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*/
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#include <common.h>
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static void do_cancel_out(u32 *num, u32 *den, u32 factor)
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{
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while (1) {
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if (((*num)/factor*factor == (*num)) &&
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((*den)/factor*factor == (*den))) {
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(*num) /= factor;
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(*den) /= factor;
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} else
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break;
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}
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}
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/*
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* Cancel out the denominator and numerator of a fraction
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* to get smaller numerator and denominator.
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*/
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void cancel_out(u32 *num, u32 *den, u32 den_limit)
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{
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do_cancel_out(num, den, 2);
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do_cancel_out(num, den, 3);
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do_cancel_out(num, den, 5);
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do_cancel_out(num, den, 7);
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do_cancel_out(num, den, 11);
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do_cancel_out(num, den, 13);
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do_cancel_out(num, den, 17);
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while ((*den) > den_limit) {
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*num /= 2;
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/*
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* Round up the denominator so that the final fraction
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* (num/den) is always <= the desired value
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*/
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*den = (*den + 1) / 2;
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}
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}
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