diff --git a/drivers/hwmon/aspeed-pwm-tacho.c b/drivers/hwmon/aspeed-pwm-tacho.c
index 40c489b..40f3139 100644
--- a/drivers/hwmon/aspeed-pwm-tacho.c
+++ b/drivers/hwmon/aspeed-pwm-tacho.c
@@ -851,6 +851,8 @@
 	ret = of_property_read_u32(child, "reg", &pwm_port);
 	if (ret)
 		return ret;
+	if (pwm_port >= ARRAY_SIZE(pwm_port_params))
+		return -EINVAL;
 	aspeed_create_pwm_port(priv, (u8)pwm_port);
 
 	ret = of_property_count_u8_elems(child, "cooling-levels");