bugfix i.mx6 pwm: prevent overflow of period_c * duty_ns

Prevent overflow by casting duty_ns to ull first. This bug came up when trying to create a 200 Hz PWM

Signed-off-by: Brecht Neyrinck <bnrn@psicontrol.com>
Acked-by: Heiko Schocher<hs@denx.de>

diff --git a/drivers/pwm/pwm-imx-util.c b/drivers/pwm/pwm-imx-util.c
index f1d0b35..79d8602 100644 (file)
--- a/drivers/pwm/pwm-imx-util.c
+++ b/drivers/pwm/pwm-imx-util.c
@@ -56,7 +56,7 @@ int pwm_imx_get_parms(int period_ns, int duty_ns, unsigned long *period_c,
        *prescale = *period_c / 0x10000 + 1;
 
        *period_c /= *prescale;
-       c = (unsigned long long)(*period_c * duty_ns);
+       c = *period_c * (unsigned long long)duty_ns;
        do_div(c, period_ns);
        *duty_c = c;