Re: [PATCH 1/4] dt-bindings: iio: adc: adi,ad4000: Add PulSAR

[Marcelo Schmitt <marcelo.schmitt1@gmail.com>]

On 11/18, Marcelo Schmitt wrote:
> On 11/15, David Lechner wrote:
> > On 11/14/24 5:50 PM, Marcelo Schmitt wrote:
> > > Extend the AD4000 series device tree documentation to also describe
> > > PulSAR devices.
> > > 
> > > Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
> > > ---
> > >  .../bindings/iio/adc/adi,ad4000.yaml          | 115 +++++++++++++++++-
> > >  1 file changed, 114 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad4000.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad4000.yaml
> > > index e413a9d8d2a2..35049071a9de 100644
> > > --- a/Documentation/devicetree/bindings/iio/adc/adi,ad4000.yaml
> > > +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad4000.yaml
> > > @@ -19,6 +19,21 @@ description: |
> > >      https://www.analog.com/media/en/technical-documentation/data-sheets/ad4020-4021-4022.pdf
> > >      https://www.analog.com/media/en/technical-documentation/data-sheets/adaq4001.pdf
> > >      https://www.analog.com/media/en/technical-documentation/data-sheets/adaq4003.pdf
> > > +    https://www.analog.com/media/en/technical-documentation/data-sheets/ad7685.pdf
> > > +    https://www.analog.com/media/en/technical-documentation/data-sheets/ad7686.pdf
> > > +    https://www.analog.com/media/en/technical-documentation/data-sheets/ad7687.pdf
> > > +    https://www.analog.com/media/en/technical-documentation/data-sheets/ad7688.pdf
> > > +    https://www.analog.com/media/en/technical-documentation/data-sheets/ad7690.pdf
> > > +    https://www.analog.com/media/en/technical-documentation/data-sheets/ad7691.pdf
> > > +    https://www.analog.com/media/en/technical-documentation/data-sheets/ad7693.pdf
> > > +    https://www.analog.com/media/en/technical-documentation/data-sheets/ad7694.pdf
> > > +    https://www.analog.com/media/en/technical-documentation/data-sheets/ad7942.pdf
> > > +    https://www.analog.com/media/en/technical-documentation/data-sheets/ad7946.pdf
> > > +    https://www.analog.com/media/en/technical-documentation/data-sheets/ad7980.pdf
> > > +    https://www.analog.com/media/en/technical-documentation/data-sheets/ad7982.pdf
> > > +    https://www.analog.com/media/en/technical-documentation/data-sheets/ad7983.pdf
> > > +    https://www.analog.com/media/en/technical-documentation/data-sheets/ad7984.pdf
> > > +    https://www.analog.com/media/en/technical-documentation/data-sheets/ad7988-1_7988-5.pdf
> > 
> > It would be nice to sort these lowest number first.
> 
> Ack
> 
Actually, I didn't get how I'm expected to sort those.
Isn't ad4000 < ad7685?
Or did you mean to put adaq at the end?

ad4000-4004-4008.pdf
...
ad4020-4021-4022.pdf
ad7685.pdf
...
ad7988-1_7988-5.pdf
adaq4001.pdf
adaq4003.pdf


[...]
> 
> > And with this many chips, it can be easy to overlook a small difference
> > in one chips, like ad7694 not having VIO pin, so is it really fallback
> > compatible? Easier to just avoid the question and not have fallbacks.
> > 
> The absence of a VIO pin does not change how the driver handles the devices.
> They are compatible from software perspective.
> 
[...]
> > >  
> > >  allOf:
> > > +  # AD7694 doesn't have a VIO pin
> > 
> > It sounds like using not: could make this if: a lot shorter.
> 
> Ack
> 
> > 
> > Also, it looks like ad7983 doesn't have the pin either.
> 
> Ack

I forgot the ad4000 driver fails if VIO is not provided so I was wrong when I
said AD7694 was software compatible with the other ADCs.
I see now AD7694 also doesn't have SDI pin.
Aside from the VIO and SDI pins, AD7694 is similar to AD7685 both being 16-bit
precision 250kSPS pseudo-differential ADCs.
The AD7683 part you mentioned is similar to AD7988-1, both 16-bit
pseudo-differential 100kSPS.
To avoid complicating things, I'm dropping support for AD7694.
AD7685 and AD7988-1 are the parts with features similar to AD7694 and AD7683,
respectively.