iio: max1363: Use devm_regulator_get_optional for optional regulator

In kernel version 3.13, devm_regulator_get() may return no error
if a regulator is undeclared. regulator_get_voltage() will return
-EINVAL if this happens. This causes the driver to fail loading if
the vref regulator is not declared.

Since vref is optional, call devm_regulator_get_optional instead.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Cc: Stable@vger.kernel.org
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/iio/adc/max1363.c b/drivers/iio/adc/max1363.c
index e283f2f2ee2f..360259266d4f 100644
--- a/drivers/iio/adc/max1363.c
+++ b/drivers/iio/adc/max1363.c
@@ -1560,7 +1560,7 @@ static int max1363_probe(struct i2c_client *client,
         st->client = client;
 
         st->vref_uv = st->chip_info->int_vref_mv * 1000;
-        vref = devm_regulator_get(&client->dev, "vref");
+        vref = devm_regulator_get_optional(&client->dev, "vref");
         if (!IS_ERR(vref)) {
                 int vref_uv;