[PATCH] staging: iio: ad7780: update voltage on read

From: Renato Lui Geh
Date: Thu Oct 25 2018 - 09:32:35 EST


The ad7780 driver previously did not read the correct device output.
This patch fixes two issues.

- The driver read an outdated value set at initialization. It now
updates its voltage on read.
- Variable val subtracted an uninitialized value on
IIO_CHAN_INFO_OFFSET. This was fixed by assiging the correct value
instead.

Signed-off-by: Renato Lui Geh <renatogeh@xxxxxxxxx>
---
drivers/staging/iio/adc/ad7780.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/iio/adc/ad7780.c b/drivers/staging/iio/adc/ad7780.c
index b67412db0318..06700fe554a2 100644
--- a/drivers/staging/iio/adc/ad7780.c
+++ b/drivers/staging/iio/adc/ad7780.c
@@ -87,16 +87,20 @@ static int ad7780_read_raw(struct iio_dev *indio_dev,
long m)
{
struct ad7780_state *st = iio_priv(indio_dev);
+ int voltage_uv = 0;

switch (m) {
case IIO_CHAN_INFO_RAW:
return ad_sigma_delta_single_conversion(indio_dev, chan, val);
case IIO_CHAN_INFO_SCALE:
+ voltage_uv = regulator_get_voltage(st->reg);
+ if (voltage_uv)
+ st->int_vref_mv = voltage_uv/1000;
*val = st->int_vref_mv * st->gain;
*val2 = chan->scan_type.realbits - 1;
return IIO_VAL_FRACTIONAL_LOG2;
case IIO_CHAN_INFO_OFFSET:
- *val -= (1 << (chan->scan_type.realbits - 1));
+ *val = -(1 << (chan->scan_type.realbits - 1));
return IIO_VAL_INT;
}

--
2.19.1