iio: adc: imx8qxp-adc: propagate regulator_get_voltage error

If the ADC vref regulator returns an error, for example, if CONFIG_REGULATOR
is not set, the error will be used as a reference voltage.

Introduce a guard for negative return values instead of unconditionally
casting it to u32.

Acked-by: Haibo Chen <haibo.chen@nxp.com>
Signed-off-by: Martin Larsson <martin.larsson@actia.se>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Link: https://lore.kernel.org/r/20220720153136.3502440-1-martin.larsson@actia.se
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/adc/imx8qxp-adc.c b/drivers/iio/adc/imx8qxp-adc.c
index e484467..36777b8 100644 (file)
--- a/drivers/iio/adc/imx8qxp-adc.c
+++ b/drivers/iio/adc/imx8qxp-adc.c
@@ -202,7 +202,7 @@ static int imx8qxp_adc_read_raw(struct iio_dev *indio_dev,
        struct imx8qxp_adc *adc = iio_priv(indio_dev);
        struct device *dev = adc->dev;
 
-       u32 ctrl, vref_uv;
+       u32 ctrl;
        long ret;
 
        switch (mask) {
@@ -245,8 +245,10 @@ static int imx8qxp_adc_read_raw(struct iio_dev *indio_dev,
                return IIO_VAL_INT;
 
        case IIO_CHAN_INFO_SCALE:
-               vref_uv = regulator_get_voltage(adc->vref);
-               *val = vref_uv / 1000;
+               ret = regulator_get_voltage(adc->vref);
+               if (ret < 0)
+                       return ret;
+               *val = ret / 1000;
                *val2 = 12;
                return IIO_VAL_FRACTIONAL_LOG2;