diff --git a/drivers/mfd/ab8500-debugfs.c b/drivers/mfd/ab8500-debugfs.c
index 810ac6faabba..e33c1628c65b 100644
--- a/drivers/mfd/ab8500-debugfs.c
+++ b/drivers/mfd/ab8500-debugfs.c
@@ -1479,7 +1479,6 @@ static ssize_t ab8500_bank_write(struct file *file,
 	unsigned long user_bank;
 	int err;
 
-	/* Get userspace string and assure termination */
 	err = kstrtoul_from_user(user_buf, count, 0, &user_bank);
 	if (err)
 		return err;
@@ -1512,7 +1511,6 @@ static ssize_t ab8500_address_write(struct file *file,
 	unsigned long user_address;
 	int err;
 
-	/* Get userspace string and assure termination */
 	err = kstrtoul_from_user(user_buf, count, 0, &user_address);
 	if (err)
 		return err;
@@ -1522,6 +1520,7 @@ static ssize_t ab8500_address_write(struct file *file,
 		return -EINVAL;
 	}
 	debug_address = user_address;
+
 	return count;
 }
 
@@ -1556,7 +1555,6 @@ static ssize_t ab8500_val_write(struct file *file,
 	unsigned long user_val;
 	int err;
 
-	/* Get userspace string and assure termination */
 	err = kstrtoul_from_user(user_buf, count, 0, &user_val);
 	if (err)
 		return err;
@@ -2418,20 +2416,13 @@ static ssize_t ab8500_gpadc_avg_sample_write(struct file *file,
 	size_t count, loff_t *ppos)
 {
 	struct device *dev = ((struct seq_file *)(file->private_data))->private;
-	char buf[32];
-	int buf_size;
 	unsigned long user_avg_sample;
 	int err;
 
-	/* Get userspace string and assure termination */
-	buf_size = min(count, (sizeof(buf) - 1));
-	if (copy_from_user(buf, user_buf, buf_size))
-		return -EFAULT;
-	buf[buf_size] = 0;
-
-	err = strict_strtoul(buf, 0, &user_avg_sample);
+	err = kstrtoul_from_user(user_buf, count, 0, &user_avg_sample);
 	if (err)
-		return -EINVAL;
+		return err;
+
 	if ((user_avg_sample == SAMPLE_1) || (user_avg_sample == SAMPLE_4)
 			|| (user_avg_sample == SAMPLE_8)
 			|| (user_avg_sample == SAMPLE_16)) {
@@ -2441,7 +2432,8 @@ static ssize_t ab8500_gpadc_avg_sample_write(struct file *file,
 			"should be egal to 1, 4, 8 or 16\n");
 		return -EINVAL;
 	}
-	return buf_size;
+
+	return count;
 }
 
 static const struct file_operations ab8500_gpadc_avg_sample_fops = {
@@ -2469,20 +2461,13 @@ static ssize_t ab8500_gpadc_trig_edge_write(struct file *file,
 	size_t count, loff_t *ppos)
 {
 	struct device *dev = ((struct seq_file *)(file->private_data))->private;
-	char buf[32];
-	int buf_size;
 	unsigned long user_trig_edge;
 	int err;
 
-	/* Get userspace string and assure termination */
-	buf_size = min(count, (sizeof(buf) - 1));
-	if (copy_from_user(buf, user_buf, buf_size))
-		return -EFAULT;
-	buf[buf_size] = 0;
-
-	err = strict_strtoul(buf, 0, &user_trig_edge);
+	err = kstrtoul_from_user(user_buf, count, 0, &user_trig_edge);
 	if (err)
-		return -EINVAL;
+		return err;
+
 	if ((user_trig_edge == RISING_EDGE)
 			|| (user_trig_edge == FALLING_EDGE)) {
 		trig_edge = (u8) user_trig_edge;
@@ -2492,7 +2477,8 @@ static ssize_t ab8500_gpadc_trig_edge_write(struct file *file,
 			"Enter 1. Falling edge\n");
 		return -EINVAL;
 	}
-	return buf_size;
+
+	return count;
 }
 
 static const struct file_operations ab8500_gpadc_trig_edge_fops = {
@@ -2520,20 +2506,13 @@ static ssize_t ab8500_gpadc_trig_timer_write(struct file *file,
 	size_t count, loff_t *ppos)
 {
 	struct device *dev = ((struct seq_file *)(file->private_data))->private;
-	char buf[32];
-	int buf_size;
 	unsigned long user_trig_timer;
 	int err;
 
-	/* Get userspace string and assure termination */
-	buf_size = min(count, (sizeof(buf) - 1));
-	if (copy_from_user(buf, user_buf, buf_size))
-		return -EFAULT;
-	buf[buf_size] = 0;
-
-	err = strict_strtoul(buf, 0, &user_trig_timer);
+	err = kstrtoul_from_user(user_buf, count, 0, &user_trig_timer);
 	if (err)
-		return -EINVAL;
+		return err;
+
 	if ((user_trig_timer >= 0) && (user_trig_timer <= 255)) {
 		trig_timer = (u8) user_trig_timer;
 	} else {
@@ -2541,7 +2520,8 @@ static ssize_t ab8500_gpadc_trig_timer_write(struct file *file,
 			"should be beetween 0 to 255\n");
 		return -EINVAL;
 	}
-	return buf_size;
+
+	return count;
 }
 
 static const struct file_operations ab8500_gpadc_trig_timer_fops = {
@@ -2569,20 +2549,13 @@ static ssize_t ab8500_gpadc_conv_type_write(struct file *file,
 	size_t count, loff_t *ppos)
 {
 	struct device *dev = ((struct seq_file *)(file->private_data))->private;
-	char buf[32];
-	int buf_size;
 	unsigned long user_conv_type;
 	int err;
 
-	/* Get userspace string and assure termination */
-	buf_size = min(count, (sizeof(buf) - 1));
-	if (copy_from_user(buf, user_buf, buf_size))
-		return -EFAULT;
-	buf[buf_size] = 0;
-
-	err = strict_strtoul(buf, 0, &user_conv_type);
+	err = kstrtoul_from_user(user_buf, count, 0, &user_conv_type);
 	if (err)
-		return -EINVAL;
+		return err;
+
 	if ((user_conv_type == ADC_SW)
 			|| (user_conv_type == ADC_HW)) {
 		conv_type = (u8) user_conv_type;
@@ -2592,7 +2565,8 @@ static ssize_t ab8500_gpadc_conv_type_write(struct file *file,
 			"Enter 1. ADC HW conversion\n");
 		return -EINVAL;
 	}
-	return buf_size;
+
+	return count;
 }
 
 static const struct file_operations ab8500_gpadc_conv_type_fops = {
@@ -2809,21 +2783,14 @@ static ssize_t ab8500_subscribe_write(struct file *file,
 				      size_t count, loff_t *ppos)
 {
 	struct device *dev = ((struct seq_file *)(file->private_data))->private;
-	char buf[32];
-	int buf_size;
 	unsigned long user_val;
 	int err;
 	unsigned int irq_index;
 
-	/* Get userspace string and assure termination */
-	buf_size = min(count, (sizeof(buf)-1));
-	if (copy_from_user(buf, user_buf, buf_size))
-		return -EFAULT;
-	buf[buf_size] = 0;
-
-	err = strict_strtoul(buf, 0, &user_val);
+	err = kstrtoul_from_user(user_buf, count, 0, &user_val);
 	if (err)
-		return -EINVAL;
+		return err;
+
 	if (user_val < irq_first) {
 		dev_err(dev, "debugfs error input < %d\n", irq_first);
 		return -EINVAL;
@@ -2843,7 +2810,7 @@ static ssize_t ab8500_subscribe_write(struct file *file,
 	 */
 	dev_attr[irq_index] = kmalloc(sizeof(struct device_attribute),
 		GFP_KERNEL);
-	event_name[irq_index] = kmalloc(buf_size, GFP_KERNEL);
+	event_name[irq_index] = kmalloc(count, GFP_KERNEL);
 	sprintf(event_name[irq_index], "%lu", user_val);
 	dev_attr[irq_index]->show = show_irq;
 	dev_attr[irq_index]->store = NULL;
@@ -2865,7 +2832,7 @@ static ssize_t ab8500_subscribe_write(struct file *file,
 		return err;
 	}
 
-	return buf_size;
+	return count;
 }
 
 static ssize_t ab8500_unsubscribe_write(struct file *file,
@@ -2873,21 +2840,14 @@ static ssize_t ab8500_unsubscribe_write(struct file *file,
 					size_t count, loff_t *ppos)
 {
 	struct device *dev = ((struct seq_file *)(file->private_data))->private;
-	char buf[32];
-	int buf_size;
 	unsigned long user_val;
 	int err;
 	unsigned int irq_index;
 
-	/* Get userspace string and assure termination */
-	buf_size = min(count, (sizeof(buf)-1));
-	if (copy_from_user(buf, user_buf, buf_size))
-		return -EFAULT;
-	buf[buf_size] = 0;
-
-	err = strict_strtoul(buf, 0, &user_val);
+	err = kstrtoul_from_user(user_buf, count, 0, &user_val);
 	if (err)
-		return -EINVAL;
+		return err;
+
 	if (user_val < irq_first) {
 		dev_err(dev, "debugfs error input < %d\n", irq_first);
 		return -EINVAL;
@@ -2912,7 +2872,7 @@ static ssize_t ab8500_unsubscribe_write(struct file *file,
 	kfree(event_name[irq_index]);
 	kfree(dev_attr[irq_index]);
 
-	return buf_size;
+	return count;
 }
 
 /*