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Message-ID: <a7e87c9a-7b3e-ea46-6171-4a87d1052a98@linaro.org>
Date:   Thu, 5 May 2022 10:43:17 +0200
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Subject: Re: [PATCH v2 2/4] dt-bindings: cpufreq: apple,soc-cpufreq: Add
 binding for Apple SoC cpufreq
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To:     Hector Martin <marcan@marcan.st>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Viresh Kumar <viresh.kumar@linaro.org>
Cc:     Sven Peter <sven@svenpeter.dev>,
        Alyssa Rosenzweig <alyssa@rosenzweig.io>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Stephen Boyd <sboyd@kernel.org>,
        Ulf Hansson <ulf.hansson@linaro.org>,
        Marc Zyngier <maz@kernel.org>,
        Mark Kettenis <mark.kettenis@xs4all.nl>,
        linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20220504075153.185208-1-marcan@marcan.st>
 <20220504075153.185208-3-marcan@marcan.st>
From:   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
In-Reply-To: <20220504075153.185208-3-marcan@marcan.st>
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Precedence: bulk

On 04/05/2022 09:51, Hector Martin wrote:
> This binding represents the cpufreq/DVFS hardware present in Apple SoCs.
> The hardware has an independent controller per CPU cluster, but we
> represent them as a single cpufreq node since there can only be one
> systemwide cpufreq device (and since in the future, interactions with
> memory controller performance states will also involve cooperation
> between multiple frequency domains).
> 
> Signed-off-by: Hector Martin <marcan@marcan.st>
> ---
>  .../bindings/cpufreq/apple,soc-cpufreq.yaml   | 121 ++++++++++++++++++
>  1 file changed, 121 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/cpufreq/apple,soc-cpufreq.yaml
> 
> diff --git a/Documentation/devicetree/bindings/cpufreq/apple,soc-cpufreq.yaml b/Documentation/devicetree/bindings/cpufreq/apple,soc-cpufreq.yaml
> new file mode 100644
> index 000000000000..f398c1bd5de5
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/cpufreq/apple,soc-cpufreq.yaml
> @@ -0,0 +1,121 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/cpufreq/apple,soc-cpufreq.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Apple SoC cpufreq device
> +
> +maintainers:
> +  - Hector Martin <marcan@marcan.st>
> +
> +description: |
> +  Apple SoCs (e.g. M1) have a per-cpu-cluster DVFS controller that is part of
> +  the cluster management register block. This binding uses the standard
> +  operating-points-v2 table to define the CPU performance states, with the
> +  opp-level property specifying the hardware p-state index for that level.
> +
> +properties:
> +  compatible:
> +    items:
> +      - enum:
> +          - apple,t8103-soc-cpufreq
> +          - apple,t6000-soc-cpufreq
> +      - const: apple,soc-cpufreq
> +
> +  reg:
> +    minItems: 1
> +    maxItems: 6

Is the number of clusters fixed for t8103 and t6000? Are these
compatibles strictly related to some specific M1 SoC? If yes, then you
should have constraints in allOf:if:then.


Best regards,
Krzysztof