| Aneesh V | c0e8852 | 2011-07-21 09:10:12 -0400 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2011 Linaro Limited |
| 3 | * Aneesh V <aneesh@ti.com> |
| 4 | * |
| 5 | * See file CREDITS for list of people who contributed to this |
| 6 | * project. |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU General Public License as |
| 10 | * published by the Free Software Foundation; either version 2 of |
| 11 | * the License, or (at your option) any later version. |
| 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | * GNU General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU General Public License |
| 19 | * along with this program; if not, write to the Free Software |
| 20 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, |
| 21 | * MA 02111-1307 USA |
| 22 | */ |
| 23 | #include <common.h> |
| 24 | static void do_cancel_out(u32 *num, u32 *den, u32 factor) |
| 25 | { |
| 26 | while (1) { |
| 27 | if (((*num)/factor*factor == (*num)) && |
| 28 | ((*den)/factor*factor == (*den))) { |
| 29 | (*num) /= factor; |
| 30 | (*den) /= factor; |
| 31 | } else |
| 32 | break; |
| 33 | } |
| 34 | } |
| 35 | |
| 36 | /* |
| 37 | * Cancel out the denominator and numerator of a fraction |
| 38 | * to get smaller numerator and denominator. |
| 39 | */ |
| 40 | void cancel_out(u32 *num, u32 *den, u32 den_limit) |
| 41 | { |
| 42 | do_cancel_out(num, den, 2); |
| 43 | do_cancel_out(num, den, 3); |
| 44 | do_cancel_out(num, den, 5); |
| 45 | do_cancel_out(num, den, 7); |
| 46 | do_cancel_out(num, den, 11); |
| 47 | do_cancel_out(num, den, 13); |
| 48 | do_cancel_out(num, den, 17); |
| 49 | while ((*den) > den_limit) { |
| 50 | *num /= 2; |
| 51 | /* |
| 52 | * Round up the denominator so that the final fraction |
| 53 | * (num/den) is always <= the desired value |
| 54 | */ |
| 55 | *den = (*den + 1) / 2; |
| 56 | } |
| 57 | } |