diff --git a/drivers/pwm/pwm-mxs.c b/drivers/pwm/pwm-mxs.c
index f75ecb09d97de3e9a80e7b0fac46f2369fc288b7..b430811e14f582a9ad66e4cad3f86fbe4569a073 100644
--- a/drivers/pwm/pwm-mxs.c
+++ b/drivers/pwm/pwm-mxs.c
@@ -35,6 +35,10 @@
 #define  PERIOD_CDIV(div)	(((div) & 0x7) << 20)
 #define  PERIOD_CDIV_MAX	8
 
+static const unsigned int cdiv[PERIOD_CDIV_MAX] = {
+	1, 2, 4, 8, 16, 64, 256, 1024
+};
+
 struct mxs_pwm_chip {
 	struct pwm_chip chip;
 	struct clk *clk;
@@ -54,13 +58,13 @@ static int mxs_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 
 	rate = clk_get_rate(mxs->clk);
 	while (1) {
-		c = rate / (1 << div);
+		c = rate / cdiv[div];
 		c = c * period_ns;
 		do_div(c, 1000000000);
 		if (c < PERIOD_PERIOD_MAX)
 			break;
 		div++;
-		if (div > PERIOD_CDIV_MAX)
+		if (div >= PERIOD_CDIV_MAX)
 			return -EINVAL;
 	}