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 | 7 +++++++
drivers/iio/adc/ad7091r-base.h | 1 +
2 files changed, 8 insertions(+)
diff --git a/drivers/iio/adc/ad7091r-base.c b/drivers/iio/adc/ad7091r-base.c
index aead72ef55b6..9d0b489966f5 100644
--- a/drivers/iio/adc/ad7091r-base.c
+++ b/drivers/iio/adc/ad7091r-base.c
@@ -217,7 +217,14 @@ int ad7091r_probe(struct device *dev, const struct ad7091r_init_info *init_info,
if (IS_ERR(st->vref)) {
if (PTR_ERR(st->vref) == -EPROBE_DEFER)
return -EPROBE_DEFER;
+
st->vref = NULL;
+ /* Enable internal vref */
+ ret = regmap_update_bits(st->map, AD7091R_REG_CONF,
+ AD7091R_REG_CONF_INT_VREF, BIT(0));
+ if (ret)
+ return dev_err_probe(st->dev, ret,
+ "Error on enable internal reference\n");
} 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 81b8a4bbb929..9cfb362a00a4 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
