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Message-ID: <390f1bf0-5f8f-840c-ea77-9d24d93f8c22@linaro.org>
Date:   Mon, 30 May 2022 13:14:34 +0200
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Subject: Re: [uL PATCH] arm64: dts: ti: k3-j721e-mcu-wakeup: Modified fss
 compatible to syscon and simple-mfd
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To:     Bhavya Kapoor <b-kapoor@ti.com>, nm@ti.com, vigneshr@ti.com
Cc:     kristo@kernel.org, p.yadav@ti.com, robh+dt@kernel.org,
        krzysztof.kozlowski+dt@linaro.org,
        linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20220530094230.53823-1-b-kapoor@ti.com>
From:   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
In-Reply-To: <20220530094230.53823-1-b-kapoor@ti.com>
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On 30/05/2022 11:42, Bhavya Kapoor wrote:
> The FSS node also contains the Hyperflash controller. Support
> will be added in future. Change the compatible to syscon to
> accommodate that.
> 
> Signed-off-by: Bhavya Kapoor <b-kapoor@ti.com>
> ---
>  arch/arm64/boot/dts/ti/k3-j721e-mcu-wakeup.dtsi | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm64/boot/dts/ti/k3-j721e-mcu-wakeup.dtsi b/arch/arm64/boot/dts/ti/k3-j721e-mcu-wakeup.dtsi
> index b4972dfb7da8..3c68094d835f 100644
> --- a/arch/arm64/boot/dts/ti/k3-j721e-mcu-wakeup.dtsi
> +++ b/arch/arm64/boot/dts/ti/k3-j721e-mcu-wakeup.dtsi
> @@ -169,8 +169,8 @@
>  		power-domains = <&k3_pds 197 TI_SCI_PD_SHARED>;
>  	};
>  
> -	fss: fss@47000000 {
> -		compatible = "simple-bus";
> +	fss: syscon@47000000 {
> +		compatible = "syscon","simple-mfd";

1. Missing space after ,.
2.  How does it work now? You expose syscon on this device node with
0x47000000 and the same time have a child device on same address range.
This looks racy and inconsistent.

3. This stops looking like simple-bus or simple-mfd:
https://lore.kernel.org/linux-devicetree/Ynq52E93mcTXcw9H@robh.at.kernel.org/

4. syscon and simple-mfd are not allowed on their own
https://lore.kernel.org/all/Ymf+OmNBaZ+7OrxD@robh.at.kernel.org/

Best regards,
Krzysztof