diff --git a/drivers/crypto/atmel-sha204a.c b/drivers/crypto/atmel-sha204a.c
index 8f422ed223d3..72c9d74d3062 100644
--- a/drivers/crypto/atmel-sha204a.c
+++ b/drivers/crypto/atmel-sha204a.c
@@ -15,6 +15,7 @@
 #include <linux/module.h>
 #include <linux/scatterlist.h>
 #include <linux/slab.h>
+#include <linux/sysfs.h>
 #include <linux/workqueue.h>
 #include "atmel-i2c.h"
 
@@ -121,21 +122,22 @@ static ssize_t otp_show(struct device *dev,
 {
 	u16 addr;
 	u8 otp[OTP_ZONE_SIZE];
-	char *str = buf;
 	struct i2c_client *client = to_i2c_client(dev);
-	int i;
+	ssize_t len = 0;
+	int i, ret;
 
-	for (addr = 0; addr < OTP_ZONE_SIZE/4; addr++) {
-		if (atmel_sha204a_otp_read(client, addr, otp + addr * 4) < 0) {
+	for (addr = 0; addr < OTP_ZONE_SIZE / 4; addr++) {
+		ret = atmel_sha204a_otp_read(client, addr, otp + addr * 4);
+		if (ret < 0) {
 			dev_err(dev, "failed to read otp zone\n");
-			break;
+			return ret;
 		}
 	}
 
-	for (i = 0; i < addr*2; i++)
-		str += sprintf(str, "%02X", otp[i]);
-	str += sprintf(str, "\n");
-	return str - buf;
+	for (i = 0; i < OTP_ZONE_SIZE; i++)
+		len += sysfs_emit_at(buf, len, "%02X", otp[i]);
+	len += sysfs_emit_at(buf, len, "\n");
+	return len;
 }
 static DEVICE_ATTR_RO(otp);