Re: [PATCH v2 5/5] arm64: dts: uniphier: Add NX1 SoC and boards support

From: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
To: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Arnd Bergmann <arnd@arndb.de>, Olof Johansson <olof@lixom.net>,
	Masami Hiramatsu <mhiramat@kernel.org>
Cc: soc@kernel.org, devicetree@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 5/5] arm64: dts: uniphier: Add NX1 SoC and boards support
Date: Tue, 8 Nov 2022 23:30:24 +0900	[thread overview]
Message-ID: <df21cfca-67ed-0c78-7f1e-13e321edabe1@socionext.com> (raw)
In-Reply-To: <f8f83839-2e76-e500-a16e-5fd2985a278d@linaro.org>

Hi Krzysztof,

On 2022/11/08 20:13, Krzysztof Kozlowski wrote:
> On 07/11/2022 11:34, Kunihiko Hayashi wrote:
>> Initial version of devicetree sources for NX1 SoC and boards.
>>
>> NX1 SoC belongs to the UniPhier armv8 architecture platform, and is
>> designed for IoT and AI/ML application fields.
>>
> 
>> +
>> +		soc_glue: syscon@1f800000 {
>> +			compatible = "socionext,uniphier-nx1-soc-glue",
>> +				     "simple-mfd", "syscon";
>> +			reg = <0x1f800000 0x2000>;
>> +
>> +			pinctrl: pinctrl {
>> +				compatible = "socionext,uniphier-nx1-pinctrl";
> 
> So instead of documenting the hardware precisily, you have one big bag
> for everything under simple-mfd. This is not how the SoC should be
> described in DTS.

Sorry I don't understand. This is inherited from the previous descriptions,
but is there some example to express DTS correctly about that?

> 
>> +			};
>> +		};
>> +
>> +		soc-glue@1f900000 {
>> +			compatible = "simple-mfd";
> 
> No, it is not allowed on its own. You need a specific compatible and
> bindings describing its children.

I saw the definition of "simple-mfd" itself is only in mfd/mfd.txt.

Currently there are only efuse devices as children, and this space means
nothing. I think it had better define the devices directly.

Thank you,
---
Best Regards
Kunihiko Hayashi