Re: [PATCH 07/10] iio: adc: at91-sama5d2_adc: fix differential channels in triggered mode

[Jonathan Cameron]

On Wed, 18 Dec 2019 16:24:02 +0000
<Eugen.Hristev@xxxxxxxxxxxxx> wrote:

> From: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>
> 
> The differential channels require writing the channel offset register (COR).
> Otherwise they do not work in differential mode.
> The configuration of COR is missing in triggered mode.
> 
> Signed-off-by: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>
I'm not totally sure whether this predates the changes here, but if it does
please pull it to the front of the set and give it a fixes tag.

Otherwise, look at merging it in with where-ever it was introduced.

Thanks,

Jonathan

> ---
>  drivers/iio/adc/at91-sama5d2_adc.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
> index a6b4dff..ccffa48 100644
> --- a/drivers/iio/adc/at91-sama5d2_adc.c
> +++ b/drivers/iio/adc/at91-sama5d2_adc.c
> @@ -900,6 +900,7 @@ static int at91_adc_buffer_postenable(struct iio_dev *indio)
>  
>  	for_each_set_bit(bit, indio->active_scan_mask, indio->num_channels) {
>  		struct iio_chan_spec const *chan = at91_adc_chan_get(indio, bit);
> +		u32 cor;
>  
>  		if (!chan)
>  			continue;
> @@ -908,6 +909,17 @@ static int at91_adc_buffer_postenable(struct iio_dev *indio)
>  		    chan->type == IIO_PRESSURE)
>  			continue;
>  
> +		cor = at91_adc_readl(st, AT91_SAMA5D2_COR);
> +
> +		if (chan->differential)
> +			cor |= (BIT(chan->channel) | BIT(chan->channel2)) <<
> +			       AT91_SAMA5D2_COR_DIFF_OFFSET;
> +		else
> +			cor &= ~(BIT(chan->channel) <<
> +			       AT91_SAMA5D2_COR_DIFF_OFFSET);
> +
> +		at91_adc_writel(st, AT91_SAMA5D2_COR, cor);
> +
>  		at91_adc_writel(st, AT91_SAMA5D2_CHER, BIT(chan->channel));
>  		if (use_irq) {
>  			at91_adc_writel(st, AT91_SAMA5D2_IER,