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Date:   Thu, 29 Oct 2020 18:50:43 +0100
From:   Krzysztof Kozlowski <krzk@kernel.org>
To:     =?utf-8?B?UGF3ZcWC?= Chmiel <pawel.mikolaj.chmiel@gmail.com>
Cc:     kgene@kernel.org, alim.akhtar@samsung.com, robh+dt@kernel.org,
        a.kesavan@samsung.com, naveenkrishna.ch@gmail.com,
        thomas.ab@samsung.com, devicetree@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] arm64: dts: exynos: Fix reboot/poweroff issues on Exynos7
Message-ID: <20201029175043.GA88508@kozik-lap>
References: <20201028210813.49874-1-pawel.mikolaj.chmiel@gmail.com>
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On Wed, Oct 28, 2020 at 10:08:13PM +0100, Paweł Chmiel wrote:
> In vendor sources for Exynos 7420, psci is not used to reboot or
> poweroff device. Instead we should use syscon reboot/poweroff.
> Previously it was not possible to poweroff (no syscon poweroff node) or
> reboot (because it was handled by psci and this way is not working for
> Exynos).

Do you want to say that PSCI cannot be used to power off or reboot?

> 
> Fixes: fb026cb65247 ("arm64: dts: Add reboot node for exynos7")
> Fixes: b9024cbc937d ("arm64: dts: Add initial device tree support for exynos7")
> Signed-off-by: Paweł Chmiel <pawel.mikolaj.chmiel@gmail.com>
> ---
>  arch/arm64/boot/dts/exynos/exynos7.dtsi | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/boot/dts/exynos/exynos7.dtsi b/arch/arm64/boot/dts/exynos/exynos7.dtsi
> index 959918f4ca45..47d54c369d03 100644
> --- a/arch/arm64/boot/dts/exynos/exynos7.dtsi
> +++ b/arch/arm64/boot/dts/exynos/exynos7.dtsi
> @@ -117,8 +117,10 @@ cpu_atlas3: cpu@3 {
>  	};
>  
>  	psci {
> -		compatible = "arm,psci-0.2";
> +		compatible = "arm,psci";

Please explain how is it related to this issue? You onle mentioned
a problem of lacking syscon-reboot node.

>  		method = "smc";
> +		cpu_off = <0x84000002>;
> +		cpu_on = <0xC4000003>;

The same question.

>  	};
>  
>  	soc: soc@0 {
> @@ -552,6 +554,13 @@ pmu_system_controller: system-controller@105c0000 {
>  			compatible = "samsung,exynos7-pmu", "syscon";
>  			reg = <0x105c0000 0x5000>;
>  
> +			poweroff: syscon-poweroff {
> +				compatible = "syscon-poweroff";
> +				regmap = <&pmu_system_controller>;
> +				offset = <0x330C>; /* PS_HOLD_CONTROL */
> +				mask = <0x5200>; /* reset value */
> +			};
> +

Instead, please include arm/exynos-syscon-restart.dtsi.

Best regards,
Krzysztof