Re: [PATCH 8/8] iio: adc: rzt2h: Add support for RZ/V2H(P) SoC

[Lad, Prabhakar]

Hi Andy,

Thank you for the review.

On Wed, Sep 30, 2026 at 10:35 AM Andy Shevchenko
<andriy.shevchenko@xxxxxxxxx> wrote:
>
> On Tue, Sep 29, 2026 at 01:42:48PM +0100, Prabhakar wrote:
>
> > Add support for the ADC found on the Renesas RZ/V2H(P) SoC, which shares
> > the RZ/T2H ADC IP but differs in channel count, sampling, calibration and
> > resolution support.
> >
> > The RZ/V2H(P) ADC provides 8 channels, has a fixed conversion time of
> > 20 ADCLK cycles, does not support calibration, and supports selectable
> > 12-bit and 8-bit conversion resolution.
> >
> > Expose the fixed sampling frequency as a read-only attribute and allow
> > the conversion resolution to be changed through the scale attribute.
> > Use extended scan types so the reported scan type follows the selected
> > resolution, and prevent resolution changes while buffered capture is
> > active.
>
> ...
>
> >       help
> >         Say yes here to build support for the ADC found in Renesas
> > -       RZ/T2H / RZ/N2H SoCs.
> > +       RZ/T2H / RZ/N2H (and similar SoCs).
>
> This wording is good for the summary above, but here please list what the
> similar SoCs are. Something like
>
>         in Renesas SoCs:
>         - RZ/N2H
>         - RZ/T2H
>         - ...specify "similar SoCs" here...
>
Ok, I will update it as suggested above.

> >         To compile this driver as a module, choose M here: the
> >         module will be called rzt2h_adc.
>
> ...
>
> > +static int rzt2h_adc_write_scale(struct iio_dev *indio_dev,
> > +                              struct iio_chan_spec const *chan,
> > +                              int val, int val2)
> > +{
> > +     struct rzt2h_adc *adc = iio_priv(indio_dev);
> > +     unsigned int i;
> > +     u64 scale;
> > +     u32 rem;
> > +
> > +     if (!(adc->chip_info->features & RZT2H_ADC_FEATURE_RES_SELECT))
> > +             return -EINVAL;
> > +
> > +     for (i = 0; i < chan->num_ext_scan_type; i++) {
> > +             scale = (u64)RZT2H_ADC_VREF_MV * NANO >>
> > +                     chan->ext_scan_type[i].realbits;
> > +             if (div_u64_rem(scale, NANO, &rem) == val && rem == val2)
> > +                     break;
> > +     }
>
> > +
>
> Blank line here is not needed.
>
Ok, I will drop it.

> > +     if (i == chan->num_ext_scan_type)
> > +             return -EINVAL;
> > +
> > +     /* The scan type changes with the resolution. */
> > +     IIO_DEV_ACQUIRE_DIRECT_MODE(indio_dev, claim);
> > +     if (IIO_DEV_ACQUIRE_FAILED(claim))
> > +             return -EBUSY;
> > +
> > +     adc->resolution = i;
> > +
> > +     return 0;
> > +}
>
> ...
>
> > +     case IIO_CHAN_INFO_SCALE:
> > +             *vals = rzv2h_adc_scale_avail;
> > +             *type = IIO_VAL_FRACTIONAL_LOG2;
> > +             *length = ARRAY_SIZE(rzv2h_adc_scale_avail);
>
> Check if array_size.h is included.
>
I will include it.

Cheers,
Prabhakar