Re: [PATCH v3 1/3] dt-bindings: spi: add spi-rx-bus-channels peripheral property

[Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>]

On Mon, 8 Jan 2024 11:15:31 -0600
David Lechner <dlechner@xxxxxxxxxxxx> wrote:

> On Mon, Jan 8, 2024 at 10:39 AM Mark Brown <broonie@xxxxxxxxxx> wrote:
> >
> > On Sun, Jan 07, 2024 at 05:02:56PM -0600, David Lechner wrote:  
> > > On Sun, Jan 7, 2024 at 3:27 PM Mark Brown <broonie@xxxxxxxxxx> wrote:  
> >  
> > > > This makes no sense to me without a corresponding change in the SPI core
> > > > and possibly controller support, though I guess you could do data
> > > > manging to rewrite from a normal parallel SPI to this for a pure
> > > > software implementation.  I also see nothing in the driver that even
> > > > attempts to parse this so I can't see how it could possibly work.  
> >  
> > > We currently don't have a controller that supports this. This is just
> > > an attempt to make a complete binding for a peripheral according to
> > > [2] which says:  
> >
> > ...
> >  
> > > So, will DT maintainers accept an incomplete binding for the
> > > peripheral? Or will you reconsider this without SPI core support if I
> > > can explain it better? It doesn't seem like a reasonable request to
> > > expect us to spend time developing software that we don't need at this
> > > time just to get a complete DT binding accepted for a feature that
> > > isn't being used.  
> >
> > I don't think it's sensible to try to make a binding for this without
> > having actually tried to put a system together that uses it and made
> > sure that everything is joined up properly, the thing about complete
> > bindings is more for things that are handle turning than for things that
> > are substantial new features in subsystems.  
> 
> We do have plans to eventually implement such a feature in an
> FPGA-based SPI controller, so if we need to wait until then for the
> binding, then we can do that. But it would be really nice if we could
> find a way forward for the IIO driver in this series without having to
> wait for the resolution of new SPI controller feature for the complete
> DT bindings.
> 
> DT/IIO maintainers, if I resubmit this series with the
> `spi-rx-bus-channels` parts removed from the iio/adc/adi,ad7380.yaml
> bindings, would that be acceptable? (Also resubmitting without this
> patch of course.)
> 
>From IIO side of things that's fine with me.

Jonathan