Re: [PATCH v16 1/3] dt-bindings: i2c: aspeed: support for AST2600-i2cv2

Krzysztof Kozlowski
2025-03-24T07:21:36Z

On 19/03/2025 12:12, Ryan Chen wrote:
>> Subject: Re: [PATCH v16 1/3] dt-bindings: i2c: aspeed: support for
>> AST2600-i2cv2
>>
>> On 17/03/2025 10:21, Ryan Chen wrote:
>>>> Neither this.
>>>>
>>>> So it seems you describe already existing and documented I2C, but for
>>>> some reason you want second compatible. The problem is that you do
>>>> not provide reason from the point of view of bindings.
>>>>
>>>> To summarize: what your users want - don't care. Start properly
>>>> describing hardware and your SoC.
>>>
>>> OK, for ast2600 i2c controller have two register mode setting.
>>> One, I call it is old register setting, that is right now i2c-aspeed.c
>>> .compatible = "aspeed,ast2600-i2c-bus", And there have a global register
>> that can set i2c controller as new mode register set.
>>> That I am going to drive. That I post is all register in new an old register list.
>>>
>>> For example,
>>> Global register [2] = 0 => i2c present as old register set Global
>>> register [2] = 1 => i2c present as new register set
>> It's the same device though, so the same compatible.
>
> Sorry, it is different design, and it share the same register space.
> So that the reason add new compatible "aspeed,ast2600-i2cv2" for this driver.
> It is different register layout.

Which device is described by the existing "aspeed,ast2600-i2c-bus"
compatible? And which device is described by new compatible?

Best regards,
Krzysztof