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

From: Krzysztof Kozlowski
Date: Fri Aug 09 2024 - 06:05:55 EST


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