Re: [PATCH v2 2/4] dt-bindings: cpufreq: apple,soc-cpufreq: Add binding for Apple SoC cpufreq

From: Krzysztof Kozlowski
Date: Thu May 05 2022 - 04:43:25 EST


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@xxxxxxxxx>
> ---
> .../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@xxxxxxxxx>
> +
> +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