Re: [PATCH v2 05/10] iio: adc: at91-sama5d2_adc: fix channel configuration for differential channels

[Jonathan Cameron <jic23@kernel.org>]

On Tue, 27 Mar 2018 15:32:38 +0300
Eugen Hristev <eugen.hristev@microchip.com> wrote:

> When iterating through the channels, the index in the array is not the
> scan index. Added an xlate function to translate to the proper index.
> This will be used also for devicetree channel xlate
> 
> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
So, this is a fix for an existing bug?

Please move this to the front of your set (to make it easier to backport).
Describe the result of the bug as well.

Fixes tag would be good.

Thanks,

Jonathan


> ---
>  drivers/iio/adc/at91-sama5d2_adc.c | 41 ++++++++++++++++++++++++++++++++++----
>  1 file changed, 37 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
> index 4eff835..8729d65 100644
> --- a/drivers/iio/adc/at91-sama5d2_adc.c
> +++ b/drivers/iio/adc/at91-sama5d2_adc.c
> @@ -333,6 +333,27 @@ static const struct iio_chan_spec at91_adc_channels[] = {
>  				+ AT91_SAMA5D2_DIFF_CHAN_CNT + 1),
>  };
>  
> +static int at91_adc_chan_xlate(struct iio_dev *indio_dev, int chan)
> +{
> +	int i;
> +
> +	for (i = 0; i < indio_dev->num_channels; i++) {
> +		if (indio_dev->channels[i].scan_index == chan)
> +			return i;
> +	}
> +	return -EINVAL;
> +}
> +
> +static inline struct iio_chan_spec const *
> +at91_adc_chan_get(struct iio_dev *indio_dev, int chan)
> +{
> +	int index = at91_adc_chan_xlate(indio_dev, chan);
> +
> +	if (index < 0)
> +		return NULL;
> +	return indio_dev->channels + index;
> +}
> +
>  static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
>  {
>  	struct iio_dev *indio = iio_trigger_get_drvdata(trig);
> @@ -350,8 +371,10 @@ static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
>  	at91_adc_writel(st, AT91_SAMA5D2_TRGR, status);
>  
>  	for_each_set_bit(bit, indio->active_scan_mask, indio->num_channels) {
> -		struct iio_chan_spec const *chan = indio->channels + bit;
> +		struct iio_chan_spec const *chan = at91_adc_chan_get(indio, bit);
>  
> +		if (!chan)
> +			continue;
>  		if (state) {
>  			at91_adc_writel(st, AT91_SAMA5D2_CHER,
>  					BIT(chan->channel));
> @@ -448,7 +471,11 @@ static int at91_adc_dma_start(struct iio_dev *indio_dev)
>  
>  	for_each_set_bit(bit, indio_dev->active_scan_mask,
>  			 indio_dev->num_channels) {
> -		struct iio_chan_spec const *chan = indio_dev->channels + bit;
> +		struct iio_chan_spec const *chan =
> +					 at91_adc_chan_get(indio_dev, bit);
> +
> +		if (!chan)
> +			continue;
>  
>  		st->dma_st.rx_buf_sz += chan->scan_type.storagebits / 8;
>  	}
> @@ -526,8 +553,11 @@ static int at91_adc_buffer_predisable(struct iio_dev *indio_dev)
>  	 */
>  	for_each_set_bit(bit, indio_dev->active_scan_mask,
>  			 indio_dev->num_channels) {
> -		struct iio_chan_spec const *chan = indio_dev->channels + bit;
> +		struct iio_chan_spec const *chan =
> +					at91_adc_chan_get(indio_dev, bit);
>  
> +		if (!chan)
> +			continue;
>  		if (st->dma_st.dma_chan)
>  			at91_adc_readl(st, chan->address);
>  	}
> @@ -587,8 +617,11 @@ static void at91_adc_trigger_handler_nodma(struct iio_dev *indio_dev,
>  
>  	for_each_set_bit(bit, indio_dev->active_scan_mask,
>  			 indio_dev->num_channels) {
> -		struct iio_chan_spec const *chan = indio_dev->channels + bit;
> +		struct iio_chan_spec const *chan =
> +					at91_adc_chan_get(indio_dev, bit);
>  
> +		if (!chan)
> +			continue;
>  		st->buffer[i] = at91_adc_readl(st, chan->address);
>  		i++;
>  	}