From d1a8368d66976ed9cb270bc1c62b79b8727e31a0 Mon Sep 17 00:00:00 2001
From: Hector Martin <marcan@marcan.st>
Date: Mon, 2 May 2022 23:21:00 +0900
Subject: [PATCH] dt-bindings: cpufreq: apple,soc-cpufreq: Add binding for
 Apple SoC cpufreq

This binding represents the cpufreq/DVFS hardware present in Apple SoCs.
The hardware has an independent controller per CPU cluster, and we
represent them as unique nodes in order to accurately describe the
hardware. The driver is responsible for binding them as a single cpufreq
device (in the Linux cpufreq model).

Acked-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Hector Martin <marcan@marcan.st>
---
 .../bindings/cpufreq/apple,cluster-cpufreq.yaml    | 117 +++++++++++++++++++++
 1 file changed, 117 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/cpufreq/apple,cluster-cpufreq.yaml

diff --git a/Documentation/devicetree/bindings/cpufreq/apple,cluster-cpufreq.yaml b/Documentation/devicetree/bindings/cpufreq/apple,cluster-cpufreq.yaml
new file mode 100644
index 0000000..76cb972
--- /dev/null
+++ b/Documentation/devicetree/bindings/cpufreq/apple,cluster-cpufreq.yaml
@@ -0,0 +1,117 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/cpufreq/apple,cluster-cpufreq.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Apple SoC cluster 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:
+    oneOf:
+      - items:
+          - enum:
+              - apple,t8103-cluster-cpufreq
+              - apple,t8112-cluster-cpufreq
+          - const: apple,cluster-cpufreq
+      - items:
+          - const: apple,t6000-cluster-cpufreq
+          - const: apple,t8103-cluster-cpufreq
+          - const: apple,cluster-cpufreq
+
+  reg:
+    maxItems: 1
+
+  '#performance-domain-cells':
+    const: 0
+
+required:
+  - compatible
+  - reg
+  - '#performance-domain-cells'
+
+additionalProperties: false
+
+examples:
+  - |
+    // This example shows a single CPU per domain and 2 domains,
+    // with two p-states per domain.
+    // Shipping hardware has 2-4 CPUs per domain and 2-6 domains.
+    cpus {
+      #address-cells = <2>;
+      #size-cells = <0>;
+
+      cpu@0 {
+        compatible = "apple,icestorm";
+        device_type = "cpu";
+        reg = <0x0 0x0>;
+        operating-points-v2 = <&ecluster_opp>;
+        performance-domains = <&cpufreq_e>;
+      };
+
+      cpu@10100 {
+        compatible = "apple,firestorm";
+        device_type = "cpu";
+        reg = <0x0 0x10100>;
+        operating-points-v2 = <&pcluster_opp>;
+        performance-domains = <&cpufreq_p>;
+      };
+    };
+
+    ecluster_opp: opp-table-0 {
+      compatible = "operating-points-v2";
+      opp-shared;
+
+      opp01 {
+        opp-hz = /bits/ 64 <600000000>;
+        opp-level = <1>;
+        clock-latency-ns = <7500>;
+      };
+      opp02 {
+        opp-hz = /bits/ 64 <972000000>;
+        opp-level = <2>;
+        clock-latency-ns = <22000>;
+      };
+    };
+
+    pcluster_opp: opp-table-1 {
+      compatible = "operating-points-v2";
+      opp-shared;
+
+      opp01 {
+        opp-hz = /bits/ 64 <600000000>;
+        opp-level = <1>;
+        clock-latency-ns = <8000>;
+      };
+      opp02 {
+        opp-hz = /bits/ 64 <828000000>;
+        opp-level = <2>;
+        clock-latency-ns = <19000>;
+      };
+    };
+
+    soc {
+      #address-cells = <2>;
+      #size-cells = <2>;
+
+      cpufreq_e: performance-controller@210e20000 {
+        compatible = "apple,t8103-cluster-cpufreq", "apple,cluster-cpufreq";
+        reg = <0x2 0x10e20000 0 0x1000>;
+        #performance-domain-cells = <0>;
+      };
+
+      cpufreq_p: performance-controller@211e20000 {
+        compatible = "apple,t8103-cluster-cpufreq", "apple,cluster-cpufreq";
+        reg = <0x2 0x11e20000 0 0x1000>;
+        #performance-domain-cells = <0>;
+      };
+    };
-- 
2.7.4