2019-06-19 13:05:02

by Olivier Moysan

Subject: [PATCH 2/5] 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.

Fixes: e2e6771c6462 ("IIO: ADC: add STM32 DFSDM sigma delta ADC support")

Signed-off-by: Olivier Moysan <[email protected]>
---
drivers/iio/adc/stm32-dfsdm-adc.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c
index cb596f104919..6b90a40882f2 100644
--- 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;

--
2.7.4

2019-06-22 09:21:50

by Jonathan Cameron

Subject: Re: [PATCH 2/5] iio: adc: stm32-dfsdm: fix data type

On Wed, 19 Jun 2019 15:03:48 +0200
Olivier Moysan <[email protected]> wrote:

> 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.
>
> Fixes: e2e6771c6462 ("IIO: ADC: add STM32 DFSDM sigma delta ADC support")
>
> Signed-off-by: Olivier Moysan <[email protected]>
Applied to the togreg branch of iio.git and pushed out as testing
for the autobuilders to play with them.

Thanks,

Jonathan

> ---
> drivers/iio/adc/stm32-dfsdm-adc.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c
> index cb596f104919..6b90a40882f2 100644
> --- 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;
>