Re: [PATCH 2/3] iio: dac: ad5706r: Add support for AD5706R DAC

Andy Shevchenko
2026-02-23T08:48:02Z

On Mon, Feb 23, 2026 at 04:49:38AM +0000, Torreno, Alexis Czezar wrote:
> > > Add support for the Analog Devices AD5706R, a 4-channel 16-bit current
> > > output digital-to-analog converter with SPI interface.
> > >
> > > Features:
> > > - 4 independent DAC channels
> > > - Hardware and software LDAC trigger
> > > - Configurable output range
> > > - PWM-based LDAC control
> > > - Dither and toggle modes
> > > - Dynamically configurable SPI speed
> > >
> > > Signed-off-by: Alexis Czezar Torreno <alexisczezar.torreno@analog.com>
> >
> > Hi Alexis
> >
> > Welcome to IIO. A few quick comments inline, but as others have observed
> > the patch is too large and needs breaking up. Also there is a lot of custom ABI.
> > Given we are reluctant to merge that at all, it definitely needs documentation
> > and careful consideration of whether it can be done with existing ABI or is
> > more appropriate in DT.
> >
> > Thanks,
> >
> > Jonathan
>
> Using this reply to acknowledge all the emails/feedback.

> Thanks for the time you spent on this large patch.
>
> It seems I will have to split this up first. I think it would be the basic driver,
> the ABI + docu, then the debugfs. Merge 1 before I submit the others.
> Will apply each feedback as I go.
>
> Some naming schemes need to be updated, to properly reflect the datasheet
> terms rather than the one internally agreed upon.
>
> The most unusual that a lot pointed out is related to the clock/.speed_hz/
> spi_engine. I was asked to make it work a bit beyond 50MHz, using a cora
> fpga. The cora processor spi is limited to 50MHz due to HW, hence the need
> to use an spi-engine. However, this is limited to the resolution on how small
> the frequencies can be changed, the spi engine only does integer division, thus
> leading me to change the clock driver of the spi_engine itself.
> I'll try to see if the implementation can be changed to something simpler and
> will make it easier for us.

Please, do remove the context you are not commenting on!
I have listed ~500 lines to understand if there is anything below.
Waste of time for each reviewer / follower...

--
With Best Regards,
Andy Shevchenko