On Mon, 25 Mar 2024 22:56:41 +0200 Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> wrote: > Hi Jonathan, > > On Mon, Mar 25, 2024 at 08:48:57PM +0000, Jonathan Cameron wrote: > > On Mon, 25 Mar 2024 22:32:41 +0200 Laurent Pinchart wrote: > > > > > The DAC081C081 is a TI DAC whose software interface is compatible with > > > the DAC5571. It is the 8-bit version of the DAC121C081, already > > > supported by the DAC5571 bindings. Extends the bindings to support this > > > chip. > > > > > > Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> > > > > Hi Laurent, > > > > Given it's a part number where no one is going to guess it is compatible > > with the DAC5571 and that we don't have a history of fallback compatibles > > I'm fine with this change, but just wanted to ask is a fallback compatible > > useful to you to run with older kernels? > > > > I should have noticed when Peter added the dac121c081. If we add a fallback > > should do that one as well. > > I've indeed noticed that there should have been a fallback for > dac121c081, but didn't stop to ponder why that wasn't the case, and just > went along with the flow :-) I agree a fallback could be useful, which > would then allow dropping patch 2/5 from this series (*). I can do so if > you prefer. > > * This is not entirely true. While the DAC1081C081 is largely compatible > with the DAC5573, they have different values for one of the power-down > resistors (2.5kΩ instead of 1kΩ if I recall correctly). To be completely > accurate, the driver should report that. We could still use the fallback > compatible, reporting the wrong power-down resistor value. > Hmm - Would anyone really care about that value being wrong? I think perhaps that's just about significant enough that maybe a fallback compatible doesn't make sense here. Jonathan > > > --- > > > Documentation/devicetree/bindings/iio/dac/ti,dac5571.yaml | 1 + > > > 1 file changed, 1 insertion(+) > > > > > > diff --git a/Documentation/devicetree/bindings/iio/dac/ti,dac5571.yaml b/Documentation/devicetree/bindings/iio/dac/ti,dac5571.yaml > > > index 79da0323c327..e59db861e2eb 100644 > > > --- a/Documentation/devicetree/bindings/iio/dac/ti,dac5571.yaml > > > +++ b/Documentation/devicetree/bindings/iio/dac/ti,dac5571.yaml > > > @@ -21,6 +21,7 @@ properties: > > > - ti,dac5573 > > > - ti,dac6573 > > > - ti,dac7573 > > > + - ti,dac081c081 > > > - ti,dac121c081 > > > > > > reg: >
