Message-ID: <d1175c3e-301d-1cbc-607c-e94051780806@samsung.com>
Date:   Thu, 9 Mar 2023 11:12:59 +0100
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Subject: Re: [PATCH 0/6] soc: samsung: pm_domains: Add Exynos850 support
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To:     Sam Protsenko <semen.protsenko@linaro.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        Rob Herring <robh+dt@kernel.org>
Cc:     Alim Akhtar <alim.akhtar@samsung.com>,
        Chanwoo Choi <cw00.choi@samsung.com>,
        Chanho Park <chanho61.park@samsung.com>,
        David Virag <virag.david003@gmail.com>,
        linux-arm-kernel@lists.infradead.org,
        linux-samsung-soc@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
From:   Marek Szyprowski <m.szyprowski@samsung.com>
In-Reply-To: <20230308230931.27261-1-semen.protsenko@linaro.org>
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References: <CGME20230308230935eucas1p1e919f4d4b020e3386ce0eac8b4c8d299@eucas1p1.samsung.com>
        <20230308230931.27261-1-semen.protsenko@linaro.org>
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Hi Sam,

On 09.03.2023 00:09, Sam Protsenko wrote:
> Power Domains in Exynos850 are not really different from other Exynos
> platforms. Enabling Exynos850 support in the PD driver is really just a
> matter of adding:
>
>      static const struct exynos_pm_domain_config exynos850_cfg = {
>          .local_pwr_cfg = 0x1,
>      };
>
> to the driver. But in the face of recent developments, e.g. this patch:
>
>      arm64: dts: exynos: move MIPI phy to PMU node in Exynos5433
>
> it looked logical to rework the PD driver a bit to support its nesting
> under the PMU node, while adding Exynos850 support to it. Initially I
> only wanted to add syscon regmap support via some dedicated property,
> but pulling PD nodes under the PMU syscon looks like more correct way.

Frankly speaking if you are changing this, you can go even further. 
Simply make PMU node a PM domain provider and specify the power domain 
as a phandle parameter. This is how it should have been done from the 
beginning, but for some unknown reasons wasn't. There is really no need 
to have a separate node for each power domain. This will also move 
implementation details to the PMU / power domain drivers and it will 
make it much easier to extend/modify it in the future. IMHO same applies 
for PHY nodes.


Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland