Re: AW: AW: [PATCH v2 1/3] dt-bindings: phy: add realtek,otto-serdes PHY binding

[Krzysztof Kozlowski <krzk@kernel.org>]

On 08/10/2024 08:56, markus.stockhausen@gmx.de wrote:
>>
>>> E.g. st,invert-ext. Something like this will be needed in the future 
>>> because the SerDes allow to swap polarity which must be changed 
>>> depending on the switch design. How to do this?
>>
>> I do not understand the hardware aspect discussed in the property description... probably because there is no hardware description at all, but instead you speak about driver.
>>
>> I do not understand how polarity has anything to do with U-Boot configuring serdes.
> 
> Maybe my lack of knowledge in platform driver programming or the naming
> conventions leads to confusion. I'm searching for knobs to control the behaviour 
> of the SerDes depending on the hardware. Two examples are (more may come):
> 
> - "ignore SerDes X": because the provided patch sequence confuses the SerDes
> and overwrites registers with wrong values that vendor patched U-Boot has setup
> correctly before. 

And if someone updates the bootloader to a bit different one, the DTS
becomes wrong? How do you handle then same board with two different
bootloaders requiring two different DTS? DTS is software-independent
description of the hardware, so this does not look like DTS property.

> 
> - "reverse polarity of SerDes X": same goes here. Some boards need inverted
> signalling on some of the SerDes to work properly. This must be configurable
> somehow.

I do not see how this is related to "control ports" property. There are
few bindings which already do this, so look at them.

Best regards,
Krzysztof