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SubjectRe: [RFC PATCH 3/9] dt-bindings: clock: Add apple,cluster-clk binding
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On 11/10/2021 18:57, Hector Martin wrote:
> This device represents the CPU performance state switching mechanism as
> a clock controller, to be used with the standard cpufreq-dt
> infrastructure.
>
> Signed-off-by: Hector Martin <marcan@marcan.st>
> ---
> .../bindings/clock/apple,cluster-clk.yaml | 115 ++++++++++++++++++
> 1 file changed, 115 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/clock/apple,cluster-clk.yaml
>
> diff --git a/Documentation/devicetree/bindings/clock/apple,cluster-clk.yaml b/Documentation/devicetree/bindings/clock/apple,cluster-clk.yaml
> new file mode 100644
> index 000000000000..9a8b863dadc0
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/apple,cluster-clk.yaml
> @@ -0,0 +1,115 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/clock/apple,cluster-clk.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: CPU cluster frequency scaling for Apple SoCs
> +
> +maintainers:
> + - Hector Martin <marcan@marcan.st>
> +
> +description: |
> + Apple SoCs control CPU cluster frequencies by using a performance state
> + index. This node represents the feature as a clock controller, and uses
> + a reference to the CPU OPP table to translate clock frequencies into
> + performance states. This allows the CPUs to use the standard cpufreq-dt
> + mechanism for frequency scaling.
> +
> +properties:
> + compatible:
> + items:
> + - enum:
> + - apple,t8103-cluster-clk
> + - const: apple,cluster-clk
> +
> + reg:
> + maxItems: 1
> +
> + '#clock-cells':
> + const: 0
> +
> + operating-points-v2:
> + $ref: /schemas/types.yaml#/definitions/phandle-array
> + description:
> + A reference to the OPP table used for the CPU cluster controlled by this
> + device instance. The table should contain an `opp-level` property for
> + every OPP, which represents the p-state index used by the hardware to
> + represent this performance level.
> +
> + OPPs may also have a `required-opps` property (see power-domains).
> +
> + power-domains:
> + maxItems: 1
> + description:
> + An optional reference to a power domain provider that links its
> + performance state to the CPU cluster performance state. This is typically
> + a memory controller. If set, the `required-opps` property in the CPU
> + frequency OPP nodes will be used to change the performance state of this
> + provider state in tandem with CPU frequency changes.
> +
> +required:
> + - compatible
> + - reg
> + - '#clock-cells'
> + - operating-points-v2
> +
> +additionalProperties: false
> +
> +

One line break.

> +examples:
> + - |
> + pcluster_opp: opp-table-1 {
> + compatible = "operating-points-v2";
> + opp-shared;
> +
> + opp01 {
> + opp-hz = /bits/ 64 <600000000>;
> + opp-microvolt = <781000>;
> + opp-level = <1>;
> + clock-latency-ns = <8000>;
> + required-opps = <&mcc_lowperf>;
> + };
> + /* intermediate p-states omitted */
> + opp15 {
> + opp-hz = /bits/ 64 <3204000000>;
> + opp-microvolt = <1081000>;
> + opp-level = <15>;
> + clock-latency-ns = <56000>;
> + required-opps = <&mcc_highperf>;
> + };
> + };
> +
> + mcc_opp: opp-table-2 {
> + compatible = "operating-points-v2";

Wrong compatible.

> +
> + mcc_lowperf: opp0 {
> + opp-level = <0>;
> + apple,memory-perf-config = <0x813057f 0x1800180>;
> + };
> + mcc_highperf: opp1 {
> + opp-level = <1>;
> + apple,memory-perf-config = <0x133 0x55555340>;
> + };
> + };
> +
> + soc {
> + #address-cells = <2>;
> + #size-cells = <2>;
> +
> + mcc: memory-controller@200200000 {
> + compatible = "apple,t8103-mcc", "apple,mcc";
> + #power-domain-cells = <0>;
> + reg = <0x2 0x200000 0x0 0x200000>;
> + operating-points-v2 = <&mcc_opp>;
> + apple,num-channels = <8>;
> + };
> +
> + clk_pcluster: clock-controller@211e20000 {
> + compatible = "apple,t8103-cluster-clk", "apple,cluster-clk";
> + #clock-cells = <0>;
> + reg = <0x2 0x11e20000 0x0 0x4000>;
> + operating-points-v2 = <&pcluster_opp>;
> + power-domains = <&mcc>;
> + };
> + };
>


Best regards,
Krzysztof

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