staging:iio:adc:ad7192: return len and fix out of range checking

Signed-off-by: NMichael Hennerich <michael.hennerich@analog.com>
Signed-off-by: NJonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/staging/iio/adc/ad7291.c

@@ -241,10 +241,14 @@ static inline ssize_t ad7291_set_hyst(struct device *dev,
 
 	if (ret < 0)
 		return ret;
-	if (data < 4096)
+	if (data > AD7291_VALUE_MASK)
 		return -EINVAL;
 
-	return ad7291_i2c_write(chip, this_attr->address, data);
+	ret = ad7291_i2c_write(chip, this_attr->address, data);
+	if (ret < 0)
+		return ret;
+
+	return len;
 }
 
 static IIO_DEVICE_ATTR(in_temp0_thresh_both_hyst_raw,
@@ -352,7 +356,7 @@ static int ad7291_write_event_value(struct iio_dev *indio_dev,
 
 	switch (IIO_EVENT_CODE_EXTRACT_CHAN_TYPE(event_code)) {
 	case IIO_VOLTAGE:
-		if (val > 0xFFF || val < 0)
+		if (val > AD7291_VALUE_MASK || val < 0)
 			return -EINVAL;
 		reg = ad7291_limit_regs[IIO_EVENT_CODE_EXTRACT_NUM(event_code)]
 			[!(IIO_EVENT_CODE_EXTRACT_DIR(event_code) ==