Re: [PATCH v2 3/3] arm64: dts: renesas: r9a09g011: Add system configuration node

[Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>]

On 11/11/2022 10:10, Biju Das wrote:
> Hi Krzysztof Kozlowski,
> 
> Thanks for the  feedback.
> 
>> -----Original Message-----
>> From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
>> Sent: 11 November 2022 08:35
>> To: Biju Das <biju.das.jz@bp.renesas.com>; Rob Herring <robh+dt@kernel.org>;
>> Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
>> Cc: Geert Uytterhoeven <geert+renesas@glider.be>; Magnus Damm
>> <magnus.damm@gmail.com>; linux-renesas-soc@vger.kernel.org;
>> devicetree@vger.kernel.org; Chris Paterson <Chris.Paterson2@renesas.com>;
>> Fabrizio Castro <fabrizio.castro.jz@renesas.com>
>> Subject: Re: [PATCH v2 3/3] arm64: dts: renesas: r9a09g011: Add system
>> configuration node
>>
>> On 10/11/2022 17:21, Biju Das wrote:
>>> Add system configuration node to RZ/V2M SoC dtsi.
>>>
>>> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
>>> ---
>>> v2:
>>>  * New patch
>>> ---
>>>  arch/arm64/boot/dts/renesas/r9a09g011.dtsi | 6 ++++++
>>>  1 file changed, 6 insertions(+)
>>>
>>> diff --git a/arch/arm64/boot/dts/renesas/r9a09g011.dtsi
>> b/arch/arm64/boot/dts/renesas/r9a09g011.dtsi
>>> index 7b949e40745a..07164d9e4a0f 100644
>>> --- a/arch/arm64/boot/dts/renesas/r9a09g011.dtsi
>>> +++ b/arch/arm64/boot/dts/renesas/r9a09g011.dtsi
>>> @@ -130,6 +130,12 @@ cpg: clock-controller@a3500000 {
>>>  			#power-domain-cells = <0>;
>>>  		};
>>>
>>> +		sysc: system-configuration@a3f03000 {
>>> +			compatible = "renesas,r9a09g011-sys";
>>> +			reg = <0 0xa3f03000 0 0x400>;
>>> +			status = "disabled";
>>
>> Why disabled? You do not have any other resources needed. This is odd.
> 
> OK, will enable by default. Currently the driver compatible is used for getting SoC
> Major and Minor versions. But later will enhance to support more features.

Whatever your driver is doing, should be rather independent of
enabling/disabling nodes in DTS. Generic rule is that all SoC
components, which do not need external resources from board, should be
enabled by default. Of course there are exceptions to this rule. DTS is
anyway description of hardware, so "driver compatible" is not
appropriate argument for this (or I miss the meaning behind this).

Best regards,
Krzysztof