On Wed, 4 Dec 2019 12:13:03 +0100
Couret Charles-Antoine <charles-antoine.couret@xxxxxxxxxxxxx> wrote:
> Le 04/12/2019 à 12:06, Jonathan Cameron a écrit :
> > On Mon, 2 Dec 2019 16:36:19 +0100
> > Couret Charles-Antoine <charles-antoine.couret@xxxxxxxxxxxxx> wrote:
> >
> >> Le 02/12/2019 à 15:13, Andrea Merello a écrit :
> >>> drivers/iio/adc/ad7949.c | 22 +++++++++++++++++-----
> >>> 1 file changed, 17 insertions(+), 5 deletions(-)
> >>>
> >>> diff --git a/drivers/iio/adc/ad7949.c b/drivers/iio/adc/ad7949.c
> >>> index 5c2b3446fa4a..2c6f60edb7ce 100644
> >>> --- a/drivers/iio/adc/ad7949.c
> >>> +++ b/drivers/iio/adc/ad7949.c
> >>> @@ -89,6 +89,7 @@ static int ad7949_spi_read_channel(struct ad7949_adc_chip *ad7949_adc, int *val,
> >>> unsigned int channel)
> >>> {
> >>> int ret;
> >>> + int i;
> >>> int bits_per_word = ad7949_adc->resolution;
> >>> int mask = GENMASK(ad7949_adc->resolution, 0);
> >>> struct spi_message msg;
> >>> @@ -100,12 +101,23 @@ static int ad7949_spi_read_channel(struct ad7949_adc_chip *ad7949_adc, int *val,
> >>> },
> >>> };
> >>>
> >>> - ret = ad7949_spi_write_cfg(ad7949_adc,
> >>> - channel << AD7949_OFFSET_CHANNEL_SEL,
> >>> - AD7949_MASK_CHANNEL_SEL);
> >>> - if (ret)
> >>> - return ret;
> >>> + /*
> >>> + * 1: write CFG for sample N and read old data (sample N-2)
> >>> + * 2: if CFG was not changed since sample N-1 then we'll get good data
> >>> + * at the next xfer, so we bail out now, otherwise we write something
> >>> + * and we read garbage (sample N-1 configuration).
> >>> + */
> >>> + for (i = 0; i < 2; i++) {
> >>> + ret = ad7949_spi_write_cfg(ad7949_adc,
> >>> + channel << AD7949_OFFSET_CHANNEL_SEL,
> >>> + AD7949_MASK_CHANNEL_SEL);
> >>> + if (ret)
> >>> + return ret;
> >>> + if (channel == ad7949_adc->current_channel)
> >>> + break;
> >>> + }
> >>>
> >>> + /* 3: write something and read actual data */
> >>> ad7949_adc->buffer = 0;
> >>> spi_message_init_with_transfers(&msg, tx, 1);
> >>> ret = spi_sync(ad7949_adc->spi, &msg);
> >> Signed-off-by: Charles-Antoine Couret <charles-antoine.couret@xxxxxxxxxxxxx>
> > Hi Charles-Antoine,
> >
> > Why a signed-off-by as opposed to a reviewed-by or similar?
> >
> > signed-off-by brings some very specific legal implications around Developer
> > Certificate of Origin, so is normally just the author plus people involved in
> > the path to upstream (maintainers).
>
> Ah sorry, I made the mistake, I wanted to add:
>
> Reviewed-by: Charles-Antoine Couret <charles-antoine.couret@xxxxxxxxxxxxx>
Great thanks.
Applied to the fixes-togreg branch of iio.git. I've also marked it for stable.
Thanks,
Jonathan
>
> Regards,
>
> Charles-Antoine COuret
>
