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
--- a/drivers/clk/mmp/clk-frac.c
+++ b/drivers/clk/mmp/clk-frac.c
@@ -40,12 +40,12 @@
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 @@
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;
}