Re: [RESEND v2 1/6] dt-bindings: power: Add JH7110 AON PMU support

Changhuang Liang
2023-04-25T09:18:41Z

On 2023/4/25 16:19, Krzysztof Kozlowski wrote:
> On 25/04/2023 09:57, Changhuang Liang wrote:
>>>>>>>>
>>>>>>>> description: |
>>>>>>>> StarFive JH7110 SoC includes support for multiple power domains which can be
>>>>>>>> @@ -17,6 +18,7 @@ properties:
>>>>>>>> compatible:
>>>>>>>> enum:
>>>>>>>> - starfive,jh7110-pmu
>>>>>>>> + - starfive,jh7110-aon-pmu
>>>>>
>>>>> I was speaking to Rob about this over the weekend, he asked:
>>>>> 'Why isn't "starfive,jh7110-aon-syscon" just the power-domain provider
>>>>> itself?'
>>>>
>>>> Maybe not, this syscon only offset "0x00" configure power switch.
>>>> other offset configure other functions, maybe not power, so this
>>>> "starfive,jh7110-aon-syscon" not the power-domain itself.
>>>>
>>>>> Do we actually need to add a new binding for this at all?
>>>>>
>>>>> Cheers,
>>>>> Conor.
>>>>>
>>>>
>>>> Maybe this patch do that.
>>>> https://lore.kernel.org/all/20230414024157.53203-6-xingyu.wu@starfivetech.com/
>>>
>>> This makes it a child-node right? I think Rob already said no to that in
>>> and earlier revision of this series. What he meant the other day was
>>> making the syscon itself a power domain controller, since the child node
>>> has no meaningful properties (reg, interrupts etc).
>>>
>>> Cheers,
>>> Conor.
>>
>> Yes, "starfive,jh7110-aon-pmu" is a child-node of "starfive,jh7110-aon-syscon".
>> In my opinion, "0x17010000" is "aon-syscon" on JH7110 SoC, and this "aon-pmu" is just
>> a part of "aon-syscon" function, so I think it is inappropriate to make "aon-syscon"
>> to a power domain controller. I think using the child-node description is closer to
>> JH7110 SoC.
>
> Unfortunately, I do not see the correlation between these, any
> connection. Why being a child of syscon block would mean that this
> should no be power domain controller? Really, why? These are two
> unrelated things.
>
> Best regards,
> Krzysztof
>

Let me summarize what has been discussed above.

There has two ways to describe this "starfive,jh7110-aon-syscon"(0x17010000).
1. (0x17010000) is power-controller node:

aon_pwrc: power-controller@17010000 {
compatible = "starfive,jh7110-aon-pmu", "syscon";
reg = <0x0 0x17010000 0x0 0x1000>;
#power-domain-cells = <1>;
};

2. (0x17010000) is syscon node, power-controller is child-node of syscon:

aon_syscon: syscon@17010000 {
compatible = "starfive,jh7110-aon-syscon", "syscon", "simple-mfd";
reg = <0x0 0x17010000 0x0 0x1000>;

aon_pwrc: power-controller {
compatible = "starfive,jh7110-aon-pmu";
#power-domain-cells = <1>;
};
};

I prefer the way of 2.
This is more in line with the hardware description of JH7110.