Re: [PATCH v2] iio: adc: stm32-dfsdm: adapt sampling rate to oversampling ratio

Jonathan Cameron
2020-01-13T22:02:17Z

On Fri, 10 Jan 2020 10:06:13 +0000
Olivier MOYSAN <olivier.moysan@st.com> wrote:

> Hi Jonathan, all,
>
> Kind reminder on this patch.
Thanks!

Applied to the togreg branch of iio.git and pushed out of testing
to give the build bots a brief period to poke at it.

Sorry again for the delay

Thanks,

Jonathan

> Regards
> Olivier
>
> On 11/27/19 2:10 PM, Olivier Moysan wrote:
> > Update sampling rate when oversampling ratio is changed
> > through the IIO ABI.
> >
> > Signed-off-by: Olivier Moysan <olivier.moysan@st.com>
> > ---
> > changes in version 2:
> > - correct title
> > ---
> > drivers/iio/adc/stm32-dfsdm-adc.c | 32 ++++++++++++++++++-------------
> > 1 file changed, 19 insertions(+), 13 deletions(-)
> >
> > diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c
> > index 0339ecdd06bd..87a842507509 100644
> > --- a/drivers/iio/adc/stm32-dfsdm-adc.c
> > +++ b/drivers/iio/adc/stm32-dfsdm-adc.c
> > @@ -1221,14 +1221,32 @@ static int stm32_dfsdm_write_raw(struct iio_dev *indio_dev,
> > unsigned int spi_freq;
> > int ret = -EINVAL;
> >
> > + switch (ch->src) {
> > + case DFSDM_CHANNEL_SPI_CLOCK_INTERNAL:
> > + spi_freq = adc->dfsdm->spi_master_freq;
> > + break;
> > + case DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_FALLING:
> > + case DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_RISING:
> > + spi_freq = adc->dfsdm->spi_master_freq / 2;
> > + break;
> > + default:
> > + spi_freq = adc->spi_freq;
> > + }
> > +
> > switch (mask) {
> > case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
> > ret = iio_device_claim_direct_mode(indio_dev);
> > if (ret)
> > return ret;
> > +
> > ret = stm32_dfsdm_compute_all_osrs(indio_dev, val);
> > - if (!ret)
> > + if (!ret) {
> > + dev_dbg(&indio_dev->dev,
> > + "Sampling rate changed from (%u) to (%u)\n",
> > + adc->sample_freq, spi_freq / val);
> > adc->oversamp = val;
> > + adc->sample_freq = spi_freq / val;
> > + }
> > iio_device_release_direct_mode(indio_dev);
> > return ret;
> >
> > @@ -1240,18 +1258,6 @@ static int stm32_dfsdm_write_raw(struct iio_dev *indio_dev,
> > if (ret)
> > return ret;
> >
> > - switch (ch->src) {
> > - case DFSDM_CHANNEL_SPI_CLOCK_INTERNAL:
> > - spi_freq = adc->dfsdm->spi_master_freq;
> > - break;
> > - case DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_FALLING:
> > - case DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_RISING:
> > - spi_freq = adc->dfsdm->spi_master_freq / 2;
> > - break;
> > - default:
> > - spi_freq = adc->spi_freq;
> > - }
> > -
> > ret = dfsdm_adc_set_samp_freq(indio_dev, val, spi_freq);
> > iio_device_release_direct_mode(indio_dev);
> > return ret;