iio: adc: stm32-dfsdm: fix data type

Fix the data type as DFSDM raw output is complements 2,
24bits left aligned in a 32-bit register.
This change does not affect AUDIO path
- Set data as signed for IIO (as for AUDIO)
- Set 8 bit right shift for IIO.
The 8 LSBs bits of data contains channel info and are masked.

Signed-off-by: Olivier Moysan <olivier.moysan@st.com>
Fixes: e2e6771c6462 ("IIO: ADC: add STM32 DFSDM sigma delta ADC support")
Acked-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c
index cb596f1..6b90a40 100644 (file)
--- a/drivers/iio/adc/stm32-dfsdm-adc.c
+++ b/drivers/iio/adc/stm32-dfsdm-adc.c
@@ -1365,11 +1365,11 @@ static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev,
                                        BIT(IIO_CHAN_INFO_SAMP_FREQ);
 
        if (adc->dev_data->type == DFSDM_AUDIO) {
-               ch->scan_type.sign = 's';
                ch->ext_info = dfsdm_adc_audio_ext_info;
        } else {
-               ch->scan_type.sign = 'u';
+               ch->scan_type.shift = 8;
        }
+       ch->scan_type.sign = 's';
        ch->scan_type.realbits = 24;
        ch->scan_type.storagebits = 32;