[PATCH 4/4] dt-bindings: serial: fsl-lpuart: add imx8ulp compatible string

[Sherry Sun]

> >>
> >> On 25/06/2023 11:48, Sherry Sun wrote:
> >>> LPUART driver adds a new compatible string for imx8ulp, and imx93 is
> >>
> >> What driver adds or not, is not really correct argument for compatibility.
> >> There are plenty of compatible devices which have both device ID
> >> entries in the driver. Why would you drop their compatibility between
> >> each other? It does not work like that... Provide clear rationale for this.
> >
> > Hi Krzysztof,
> > We take imx7ulp lpuart as the basic version IP, then imx8ulp adds some
> improved features based on the imx7ulp lpuart IP.
> > Actually imx8ulp can also work with the imx7ulp version, we can say it is
> compatible with imx7ulp, but we need to enable those new features by
> default on imx8ulp, so we added the imx8ulp-lpuart compatible in lpuart
> driver. So for this case, maybe compatible = "fsl,imx8ulp-lpuart",
> "fsl,imx7ulp-lpuart" is correct for imx8ulp platform, right?
> >
> > Then we have the imx93 family with the same lpuart version as imx8ulp, so
> how should we handle the compatible string for imx93 platform? Maybe
> compatible = "fsl,imx93-lpuart", "fsl,imx8ulp-lpuart", "fsl,imx7ulp-lpuart"?
> But three compatible strings looks too long for me, so I want to drop
> imx7ulp-lpuart and take imx8ulp-lpuart as the basic compatible string for
> imx93 and later others imx9 series, I am not sure if it is suitable, some
> suggestions here will be appreciate, thanks!
> >
> 
> Wrap your responses.
> 
> So write that the reason of this change is because looks too long for you and
> we will judge that rationale. Three compatibles is still fine.
> 
Hi Krzysztof,
Got it, thanks for your suggestion, I will use three compatibles for imx93.

Best Regards
Sherry