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Message-ID: <3bc9c34a-ba55-61c5-87ea-80b369841873@linaro.org>
Date:   Fri, 14 Jul 2023 07:26:57 +0200
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Subject: Re: [PATCH] arm64: dts: exynos: add pwm node for exynosautov9-sadk
Content-Language: en-US
To:     Jaewon Kim <jaewon02.kim@samsung.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Alim Akhtar <alim.akhtar@samsung.com>
Cc:     devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org,
        Chanho Park <chanho61.park@samsung.com>
References: <CGME20230714052025epcas2p46d5485a277c9f21ace14300dd9d7b4d8@epcas2p4.samsung.com>
 <20230714051521.22720-1-jaewon02.kim@samsung.com>
From:   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
In-Reply-To: <20230714051521.22720-1-jaewon02.kim@samsung.com>
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On 14/07/2023 07:15, Jaewon Kim wrote:
> Add pwm node to support fan on exynosautov9-sadk board.
> PWM channel 3 of ExynosAutov9 is connected to fan for SoC cooling
> in SADK board.
> 
> Signed-off-by: Jaewon Kim <jaewon02.kim@samsung.com>
> ---
>  arch/arm64/boot/dts/exynos/exynosautov9-sadk.dts | 6 ++++++
>  arch/arm64/boot/dts/exynos/exynosautov9.dtsi     | 9 +++++++++
>  2 files changed, 15 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/exynos/exynosautov9-sadk.dts b/arch/arm64/boot/dts/exynos/exynosautov9-sadk.dts
> index 898c2fc345ed..e717bb1cad81 100644
> --- a/arch/arm64/boot/dts/exynos/exynosautov9-sadk.dts
> +++ b/arch/arm64/boot/dts/exynos/exynosautov9-sadk.dts
> @@ -50,6 +50,12 @@
>  	};
>  };
>  
> +&pwm {
> +	pinctrl-names = "default";
> +	pinctrl-0 = <&pwm_tout3>;
> +	status = "okay";
> +};
> +
>  &serial_0 {
>  	pinctrl-0 = <&uart0_bus_dual>;
>  	status = "okay";
> diff --git a/arch/arm64/boot/dts/exynos/exynosautov9.dtsi b/arch/arm64/boot/dts/exynos/exynosautov9.dtsi
> index d3c5cdeff47f..e8860b03fe89 100644
> --- a/arch/arm64/boot/dts/exynos/exynosautov9.dtsi
> +++ b/arch/arm64/boot/dts/exynos/exynosautov9.dtsi
> @@ -1560,6 +1560,15 @@
>  			samsung,syscon-phandle = <&pmu_system_controller>;
>  			samsung,cluster-index = <1>;
>  		};
> +
> +		pwm: pwm@103f0000 {
> +			compatible = "samsung,exynos4210-pwm";

Thanks for the patch. I think we should change existing practice for
Samsung SoC and start adding dedicated specific compatible for such
blocks. It's the same practice we follow in other SoCs. It's also
recommendation I give to other platforms.

Therefore this should be "samsung,exynosautov9-pwm",
"samsung,exynos4210-pwm". Feel free to update other DTS as well.

> +			reg = <0x103f0000 0x100>;
> +			samsung,pwm-outputs = <0>, <1>, <2>, <3>;
> +			#pwm-cells = <3>;
> +			clocks = <&xtcxo>;

This does not look like correct clock. Are you sure XTCXO goes to PWM?


Best regards,
Krzysztof