The ADC needs a voltage reference to work correctly.
Enable AD7091R internal voltage reference if no external vref is
supplied.
Signed-off-by: Marcelo Schmitt <marcelo.schmitt@xxxxxxxxxx>
---
drivers/iio/adc/ad7091r-base.c | 9 ++++++---
drivers/iio/adc/ad7091r-base.h | 1 +
2 files changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/iio/adc/ad7091r-base.c b/drivers/iio/adc/ad7091r-base.c
index f2cb638b8d77..59a7ec44955d 100644
--- a/drivers/iio/adc/ad7091r-base.c
+++ b/drivers/iio/adc/ad7091r-base.c
@@ -215,10 +215,13 @@ int ad7091r_probe(struct device *dev, const char *name,
iio_dev->channels = st->chip_info->channels;
st->vref = devm_regulator_get_optional(dev, "vref");
- if (IS_ERR(st->vref)) {
- if (PTR_ERR(st->vref) == -EPROBE_DEFER)
- return -EPROBE_DEFER;
+ if (IS_ERR_OR_NULL(st->vref)) {
+ /* Enable internal vref */
st->vref = NULL;
+ ret = regmap_update_bits(st->map, AD7091R_REG_CONF,
+ AD7091R_REG_CONF_INT_VREF, BIT(0));
+ if (ret)
+ return ret;
} else {
ret = regulator_enable(st->vref);
if (ret)
diff --git a/drivers/iio/adc/ad7091r-base.h b/drivers/iio/adc/ad7091r-base.h
index 9546d0bf1da7..e153c2d7deb5 100644
--- a/drivers/iio/adc/ad7091r-base.h
+++ b/drivers/iio/adc/ad7091r-base.h
@@ -20,6 +20,7 @@
#define AD7091R_REG_CH_HYSTERESIS(ch) ((ch) * 3 + 6)
/* AD7091R_REG_CONF */
+#define AD7091R_REG_CONF_INT_VREF BIT(0)
#define AD7091R_REG_CONF_ALERT_EN BIT(4)
#define AD7091R_REG_CONF_AUTO BIT(8)
#define AD7091R_REG_CONF_CMD BIT(10)
--
2.42.0
