Re: [PATCH v2 1/3] dt-bindings: serial: Add Loongson UART controller

[郑豪威]

在 2024/8/9 18:05, Krzysztof Kozlowski 写道:
> On 09/08/2024 11:55, 郑豪威 wrote:
> > > > > > +    description: Enables fractional-N division. Currently,
> > > > > > +      only LS2K1500 and LS2K2000 support this feature.
> > > > > > +
> > > > > > +  rts-invert:
> > > > > > +    description: Inverts the RTS value in the MCR register.
> > > > > > +      This should be used on Loongson-3 series CPUs, Loongson-2K
> > > > > > +      series CPUs, and Loongson LS7A bridge chips.
> > > > > > +
> > > > > > +  dtr-invert:
> > > > > > +    description: Inverts the DTR value in the MCR register.
> > > > > > +      This should be used on Loongson-3 series CPUs, Loongson-2K
> > > > > > +      series CPUs, and Loongson LS7A bridge chips.
> > > > > > +
> > > > > > +  cts-invert:
> > > > > > +    description: Inverts the CTS value in the MSR register.
> > > > > > +      This should be used on Loongson-2K0500, Loongson-2K1000,
> > > > > > +      and Loongson LS7A bridge chips.
> > > > > > +
> > > > > > +  dsr-invert:
> > > > > > +    description: Inverts the DSR value in the MSR register.
> > > > > > +      This should be used on Loongson-2K0500, Loongson-2K1000,
> > > > > > +      and Loongson LS7A bridge chips.
> > > Same questions for all these. Why choosing invert is a board level
> > > decision? If it "should be used" then why it is not used always?
> > Because these features are not applicable to all chips, such as
> > 'fractional-division',
> Hm?
>
> > which is currently supported only by 2K1500 and 2K2000, and for
> > Loongson-3 series
> These are SoCs. Compatible defines that. Please align with your
> colleagues, because *we talked about this* already.
>
> Best regards,
> Krzysztof

I consulted with my colleagues and would like to confirm with you. For 
the five

properties provided, fractional-division is offered as a new feature,  
supported by

2K1500 and 2K2000. As for the invert property, it is due to a bug in our 
controller,

and its usage may vary across different chips. Should we add different 
compatible

values to address these issues for different chips, whether they are new 
features or

controller bugs?


Best regards,

Haowei Zheng