Re: [PATCH v3 5/7] arm64: dts: axiado: Add initial support for AX3000 SoC and eval board

[Harshit Shah <hshah@axiado.com>]

On 6/26/2025 1:50 AM, Krzysztof Kozlowski wrote:
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>
> On 26/06/2025 03:31, Harshit Shah wrote:
>> On 6/24/2025 11:05 PM, Krzysztof Kozlowski wrote:
>>>>
>>>>>> +                     compatible = "xlnx,zynqmp-uart", "cdns,uart-r1p12";
>>>>> NAK, you do not have xlnx here. Look at your SoC: name of vendor is
>>>>> axiado. Not xlnx. How is your SoC called? Also zynqmp? You cannot just
>>>>> randomly pick any compatibles and stuff them around.
>>>>>
>>>>> Please carefully read writing bindings from DT directory.
>>>> We are using the "cdns,uart-r1p12" for the UART. However, that alone
>>>> can't be added alone in the compatible as per the DT bindings doc.
>>> Exactly. See writing bindings... or any guides/talks.
>> We will add the "compatible = "axiado,ax-uart", "cdns,uart-r1p12". We
>> will append in the dt-bindings doc and driver.
>>
>> Is this name look good?
> No, all compatibles for SoC must be SoC specific. Take any recent
> Qualcomm SM8650 or SM8750 as example.
>
> I asked to read writing bindings. Did you read it? It covers exactly
> this case.
>
> Best regards,
> Krzysztof


Extremely sorry for the last reply. It got messed up in formatting, 
re-sending the same.


Thank you for the references.

Yes, I missed the point in the writing bindings doc. It says the following:


"For sub-blocks/components of bigger device (e.g. SoC blocks) use rather 
device-based compatible (e.g. SoC-based compatible),

  instead of custom versioning of that component. For example use 
"vendor,soc1234-i2c" instead of "vendor,i2c-v2"."


(Ref: 
https://elixir.bootlin.com/linux/v6.15.3/source/Documentation/devicetree/bindings/writing-bindings.rst#L79) 


# We need to add the full SoC name instead of versioning. e.g. 
compatible should contain full SoC name ax3000.


Another example, we have seen is the designware I2C IP is used by MSCC, 
ocelot chipset.

It is showing as below in the following: 
(https://elixir.bootlin.com/linux/v6.16-rc3/source/Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml) 


     i2c@100400 {

       compatible = "mscc,ocelot-i2c", "snps,designware-i2c";

       reg = <0x100400 0x100>, <0x198 0x8>;

       pinctrl-0 = <&i2c_pins>;

       pinctrl-names = "default";

       interrupts = <8>;

       clocks = <&ahb_clk>;

     };


# We will add this compatible in the existing driver 
(drivers/tty/serial/xilinx_uartps.c) &

bindings (Documentation/devicetree/bindings/serial/cdns,uart.yaml) since 
the IP is common.


As per the above examples,  I see two types of bindings.

1. compatible = "axiado,ax3000-uart", "cdns,uart-r1p12"

OR

2. compatible = "axiado,ax3000-uart"

Can you please help for this options? Apologies for the long thread again.


Regards,

Harshit.