[PATCH AUTOSEL 4.20 051/304] staging: iio: ad7780: update voltage on read

[Sasha Levin]

From: Renato Lui Geh <renato...@gmail.com>

[ Upstream commit 336650c785b62c3bea7c8cf6061c933a90241f67 ]

The ad7780 driver previously did not read the correct device output, as
it read an outdated value set at initialization. It now updates its
voltage on read.

Signed-off-by: Renato Lui Geh <renato...@gmail.com>
Acked-by: Alexandru Ardelean <alexandru.ardel...@analog.com>
Signed-off-by: Jonathan Cameron <jonathan.came...@huawei.com>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 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..c7cb05cedbbc 100644
--- a/drivers/staging/iio/adc/ad7780.c
+++ b/drivers/staging/iio/adc/ad7780.c
@@ -87,12 +87,16 @@ static int ad7780_read_raw(struct iio_dev *indio_dev,
                           long m)
 {
        struct ad7780_state *st = iio_priv(indio_dev);
+       int voltage_uv;
 
        switch (m) {
        case IIO_CHAN_INFO_RAW:
                return ad_sigma_delta_single_conversion(indio_dev, chan, val);
        case IIO_CHAN_INFO_SCALE:
-               *val = st->int_vref_mv * st->gain;
+               voltage_uv = regulator_get_voltage(st->reg);
+               if (voltage_uv < 0)
+                       return voltage_uv;
+               *val = (voltage_uv / 1000) * st->gain;
                *val2 = chan->scan_type.realbits - 1;
                return IIO_VAL_FRACTIONAL_LOG2;
        case IIO_CHAN_INFO_OFFSET:
-- 
2.19.1