From c45693a6480cee906557a9fba533a9f3c224f91e Mon Sep 17 00:00:00 2001 From: Chao Xie Date: Thu, 23 Jan 2014 10:47:41 +0800 Subject: clk: mmp: fix the wrong calculation formula The formula is numerator/denominator = Fin / (Fout * factor) So Fout = Fin * denominator / (numerator * factor). Current clk_factor_round_rate and clk_factor_recalc_rate use wrong formula. This patch will fix them. Signed-off-by: Chao Xie Signed-off-by: Mike Turquette --- drivers/clk/mmp/clk-frac.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'drivers/clk/mmp') diff --git a/drivers/clk/mmp/clk-frac.c b/drivers/clk/mmp/clk-frac.c index f6e7691c4efa..5863a37ec84d 100644 --- a/drivers/clk/mmp/clk-frac.c +++ b/drivers/clk/mmp/clk-frac.c @@ -40,12 +40,12 @@ static long clk_factor_round_rate(struct clk_hw *hw, unsigned long drate, for (i = 0; i < factor->ftbl_cnt; i++) { prev_rate = rate; - rate = (((*prate / 10000) * factor->ftbl[i].num) / - (factor->ftbl[i].den * factor->masks->factor)) * 10000; + rate = (((*prate / 10000) * factor->ftbl[i].den) / + (factor->ftbl[i].num * factor->masks->factor)) * 10000; if (rate > drate) break; } - if (i == 0) + if ((i == 0) || (i == factor->ftbl_cnt)) return rate; else return prev_rate; @@ -85,8 +85,8 @@ static int clk_factor_set_rate(struct clk_hw *hw, unsigned long drate, for (i = 0; i < factor->ftbl_cnt; i++) { prev_rate = rate; - rate = (((prate / 10000) * factor->ftbl[i].num) / - (factor->ftbl[i].den * factor->masks->factor)) * 10000; + rate = (((prate / 10000) * factor->ftbl[i].den) / + (factor->ftbl[i].num * factor->masks->factor)) * 10000; if (rate > drate) break; } -- cgit v1.2.3-59-g8ed1b