diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c
index 16f32576b320..d77cec2769b7 100644
--- a/drivers/pwm/pwm-lpss.c
+++ b/drivers/pwm/pwm-lpss.c
@@ -97,6 +97,8 @@ static void pwm_lpss_prepare(struct pwm_lpss_chip *lpwm, struct pwm_device *pwm,
 	freq *= base_unit_range;
 
 	base_unit = DIV_ROUND_CLOSEST_ULL(freq, c);
+	/* base_unit must not be 0 and we also want to avoid overflowing it */
+	base_unit = clamp_val(base_unit, 1, base_unit_range - 1);
 
 	on_time_div = 255ULL * duty_ns;
 	do_div(on_time_div, period_ns);
@@ -105,7 +107,6 @@ static void pwm_lpss_prepare(struct pwm_lpss_chip *lpwm, struct pwm_device *pwm,
 	orig_ctrl = ctrl = pwm_lpss_read(pwm);
 	ctrl &= ~PWM_ON_TIME_DIV_MASK;
 	ctrl &= ~((base_unit_range - 1) << PWM_BASE_UNIT_SHIFT);
-	base_unit &= (base_unit_range - 1);
 	ctrl |= (u32) base_unit << PWM_BASE_UNIT_SHIFT;
 	ctrl |= on_time_div;