[PATCH 5.2 76/85] iio: adc: stm32-dfsdm: fix data type

Greg Kroah-Hartman
2019-09-18T06:27:24Z

From: Olivier Moysan <olivier.moysan@st.com>

commit c6013bf50e2a2a94ab3d012e191096432aa50c6f upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/iio/adc/stm32-dfsdm-adc.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- 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
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;