Re: [PATCH v2 2/2] iio: adc: at91: fix wrong channel number in triggered buffer mode

[Jonathan Cameron]

On Tue, 25 Sep 2018 15:17:57 +0200
Ludovic Desroches <ludovic.desroches@xxxxxxxxxxxxx> wrote:

> On Mon, Sep 24, 2018 at 10:51:44AM +0300, Eugen Hristev wrote:
> > When channels are registered, the hardware channel number is not the
> > actual iio channel number.
> > This is because the driver is probed with a certain number of accessible
> > channels. Some pins are routed and some not, depending on the description of
> > the board in the DT.
> > Because of that, channels 0,1,2,3 can correspond to hardware channels
> > 2,3,4,5 for example.
> > In the buffered triggered case, we need to do the translation accordingly.
> > Fixed the channel number to stop reading the wrong channel.
> > 
> > Fixes 0e589d5fb "ARM: AT91: IIO: Add AT91 ADC driver."
> > Cc: Maxime Ripard <maxime.ripard@xxxxxxxxxxx>
> > Signed-off-by: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>  
> Acked-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxxxxxx>

Applied to the togreg branch of iio.git and pushed out as testing for the
autobuilders to play with it.

Thanks,

Jonathan

> 
> > ---
> > Changes in v2:
> > - Added 'const' spec to the declaration to avoid build warning
> > 
> >  drivers/iio/adc/at91_adc.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
> > index e3be88e..75d2f73 100644
> > --- a/drivers/iio/adc/at91_adc.c
> > +++ b/drivers/iio/adc/at91_adc.c
> > @@ -248,12 +248,14 @@ static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
> >  	struct iio_poll_func *pf = p;
> >  	struct iio_dev *idev = pf->indio_dev;
> >  	struct at91_adc_state *st = iio_priv(idev);
> > +	struct iio_chan_spec const *chan;
> >  	int i, j = 0;
> >  
> >  	for (i = 0; i < idev->masklength; i++) {
> >  		if (!test_bit(i, idev->active_scan_mask))
> >  			continue;
> > -		st->buffer[j] = at91_adc_readl(st, AT91_ADC_CHAN(st, i));
> > +		chan = idev->channels + i;
> > +		st->buffer[j] = at91_adc_readl(st, AT91_ADC_CHAN(st, chan->channel));
> >  		j++;
> >  	}
> >  
> > -- 
> > 2.7.4
> >