diff --git a/arch/avr32/kernel/cpu.c b/arch/avr32/kernel/cpu.c
index 2233be71e2e8..0341ae27c9ec 100644
--- a/arch/avr32/kernel/cpu.c
+++ b/arch/avr32/kernel/cpu.c
@@ -39,10 +39,12 @@ static ssize_t store_pc0event(struct device *dev,
 			      size_t count)
 {
 	unsigned long val;
-	char *endp;
+	int ret;
 
-	val = simple_strtoul(buf, &endp, 0);
-	if (endp == buf || val > 0x3f)
+	ret = kstrtoul(buf, 0, &val);
+	if (ret)
+		return ret;
+	if (val > 0x3f)
 		return -EINVAL;
 	val = (val << 12) | (sysreg_read(PCCR) & 0xfffc0fff);
 	sysreg_write(PCCR, val);
@@ -61,11 +63,11 @@ static ssize_t store_pc0count(struct device *dev,
 				const char *buf, size_t count)
 {
 	unsigned long val;
-	char *endp;
+	int ret;
 
-	val = simple_strtoul(buf, &endp, 0);
-	if (endp == buf)
-		return -EINVAL;
+	ret = kstrtoul(buf, 0, &val);
+	if (ret)
+		return ret;
 	sysreg_write(PCNT0, val);
 
 	return count;
@@ -84,10 +86,12 @@ static ssize_t store_pc1event(struct device *dev,
 			      size_t count)
 {
 	unsigned long val;
-	char *endp;
+	int ret;
 
-	val = simple_strtoul(buf, &endp, 0);
-	if (endp == buf || val > 0x3f)
+	ret = kstrtoul(buf, 0, &val);
+	if (ret)
+		return ret;
+	if (val > 0x3f)
 		return -EINVAL;
 	val = (val << 18) | (sysreg_read(PCCR) & 0xff03ffff);
 	sysreg_write(PCCR, val);
@@ -106,11 +110,11 @@ static ssize_t store_pc1count(struct device *dev,
 			      size_t count)
 {
 	unsigned long val;
-	char *endp;
+	int ret;
 
-	val = simple_strtoul(buf, &endp, 0);
-	if (endp == buf)
-		return -EINVAL;
+	ret = kstrtoul(buf, 0, &val);
+	if (ret)
+		return ret;
 	sysreg_write(PCNT1, val);
 
 	return count;
@@ -129,11 +133,11 @@ static ssize_t store_pccycles(struct device *dev,
 			      size_t count)
 {
 	unsigned long val;
-	char *endp;
+	int ret;
 
-	val = simple_strtoul(buf, &endp, 0);
-	if (endp == buf)
-		return -EINVAL;
+	ret = kstrtoul(buf, 0, &val);
+	if (ret)
+		return ret;
 	sysreg_write(PCCNT, val);
 
 	return count;
@@ -152,11 +156,11 @@ static ssize_t store_pcenable(struct device *dev,
 			      size_t count)
 {
 	unsigned long pccr, val;
-	char *endp;
+	int ret;
 
-	val = simple_strtoul(buf, &endp, 0);
-	if (endp == buf)
-		return -EINVAL;
+	ret = kstrtoul(buf, 0, &val);
+	if (ret)
+		return ret;
 	if (val)
 		val = 1;