clk: fixed-factor: round_rate should use do_div
clk->rate = parent->rate / div * mult
The formula is OK. But it may overflow while we do operate with
unsigned long. So use do_div instead.
Signed-off-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: improved $SUBJECT]
diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-factor.c
index a489985..1ef271e 100644
--- a/drivers/clk/clk-fixed-factor.c
+++ b/drivers/clk/clk-fixed-factor.c
@@ -28,8 +28,11 @@
unsigned long parent_rate)
{
struct clk_fixed_factor *fix = to_clk_fixed_factor(hw);
+ unsigned long long int rate;
- return parent_rate * fix->mult / fix->div;
+ rate = (unsigned long long int)parent_rate * fix->mult;
+ do_div(rate, fix->div);
+ return (unsigned long)rate;
}
static long clk_factor_round_rate(struct clk_hw *hw, unsigned long rate,