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Message-ID: <fbafc16d-d6fa-4c57-8fc8-a1db09d03e05@linaro.org>
Date: Tue, 28 May 2024 11:08:02 +0200
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From: neil.armstrong@linaro.org
Reply-To: neil.armstrong@linaro.org
Subject: Re: [PATCH 3/3] arm64: dts: amlogic: a4: add power domain controller
 node
To: Xianwei Zhao <xianwei.zhao@amlogic.com>, Rob Herring <robh@kernel.org>,
 Krzysztof Kozlowski <krzk+dt@kernel.org>, Conor Dooley
 <conor+dt@kernel.org>, Kevin Hilman <khilman@baylibre.com>,
 Jerome Brunet <jbrunet@baylibre.com>,
 Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
 Jianxin Pan <jianxin.pan@amlogic.com>, Ulf Hansson <ulf.hansson@linaro.org>
Cc: devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
 linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org,
 linux-pm@vger.kernel.org
References: <20240528-a4_secpowerdomain-v1-0-2a9d7df9b128@amlogic.com>
 <20240528-a4_secpowerdomain-v1-3-2a9d7df9b128@amlogic.com>
 <c97b12bb-8b56-4129-a292-588226a0ec42@linaro.org>
 <70083d10-483e-4daf-a408-020f0147c5cf@amlogic.com>
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On 28/05/2024 11:00, Xianwei Zhao wrote:
> Hi Neil,
>     Thanks for your quickly reply.
> 
> On 2024/5/28 16:46, Neil Armstrong wrote:
>> [ EXTERNAL EMAIL ]
>>
>> On 28/05/2024 10:39, Xianwei Zhao via B4 Relay wrote:
>>> From: Xianwei Zhao <xianwei.zhao@amlogic.com>
>>>
>>> Add power domain controller node for Amlogic A4 SoC
>>>
>>> Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
>>> ---
>>>   arch/arm64/boot/dts/amlogic/amlogic-a4-common.dtsi | 4 ++++
>>>   arch/arm64/boot/dts/amlogic/amlogic-a4.dtsi        | 5 +++++
>>>   2 files changed, 9 insertions(+)
>>>
>>> diff --git a/arch/arm64/boot/dts/amlogic/amlogic-a4-common.dtsi b/arch/arm64/boot/dts/amlogic/amlogic-a4-common.dtsi
>>> index b6106ad4a072..eebde77ae5b4 100644
>>> --- a/arch/arm64/boot/dts/amlogic/amlogic-a4-common.dtsi
>>> +++ b/arch/arm64/boot/dts/amlogic/amlogic-a4-common.dtsi
>>> @@ -27,6 +27,10 @@ xtal: xtal-clk {
>>>               #clock-cells = <0>;
>>>       };
>>>
>>> +     sm: secure-monitor {
>>> +             compatible = "amlogic,meson-gxbb-sm";
>>> +     };
>>> +
>>>       soc {
>>>               compatible = "simple-bus";
>>>               #address-cells = <2>;
>>> diff --git a/arch/arm64/boot/dts/amlogic/amlogic-a4.dtsi b/arch/arm64/boot/dts/amlogic/amlogic-a4.dtsi
>>> index 73ca1d7eed81..917c05219b9c 100644
>>> --- a/arch/arm64/boot/dts/amlogic/amlogic-a4.dtsi
>>> +++ b/arch/arm64/boot/dts/amlogic/amlogic-a4.dtsi
>>> @@ -37,4 +37,9 @@ cpu3: cpu@3 {
>>>                       enable-method = "psci";
>>>               };
>>>       };
>>> +
>>> +     pwrc: power-controller {
>>> +             compatible = "amlogic,a4-pwrc";
>>> +             #power-domain-cells = <1>;
>>> +     };
>>
>> pwrc is supposed to be a child of secure-monitor.
>>
> Considered writing it like this when I wrote this.
> 
> Here are two approaches: one is to include secure-monitor in the comm dtsi and fill power-controller by aliases in dtsi of each chip, while the other is to directly include secure-monitor in the dtsi of each chip. Which one do you suggest?

The bindings mandates it to be a child of the secure monitor.

Neil

> 
>> Neil
>>
>>>   };
>>>
>>