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 <chao.xie@marvell.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

diff --git a/drivers/clk/mmp/clk-frac.c b/drivers/clk/mmp/clk-frac.c
index f6e7691..5863a37 100644 (file)
--- 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;
        }