[PATCH v2 1/2] dt-bindings: devfreq: Document support for Airoha Subsystem Scale

[Christian Marangi]

Airoha SoC contains multiple subsystems that are scaled to a
specific OPP taking the CPU clock as reference. Such subsystem
can enter idle or performance state based on the system load
and power consumption conditions.

Example of such subsystems are GSW (Gigabit Switch), NPU (Custom
Risc Co-Processor for Network acceleration), SOE (Crypto Module) BUS...

Document all the required property and provide examples for the various
subsystem OPP + subsystem scale nodes.

Signed-off-by: Christian Marangi <ansuelsmth@xxxxxxxxx>
---
 .../devfreq/airoha,subsystem-scale.yaml       | 114 ++++++++++++++++++
 1 file changed, 114 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/devfreq/airoha,subsystem-scale.yaml

diff --git a/Documentation/devicetree/bindings/devfreq/airoha,subsystem-scale.yaml b/Documentation/devicetree/bindings/devfreq/airoha,subsystem-scale.yaml
new file mode 100644
index 000000000000..2cf7f23a926c
--- /dev/null
+++ b/Documentation/devicetree/bindings/devfreq/airoha,subsystem-scale.yaml
@@ -0,0 +1,114 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/devfreq/airoha,subsystem-scale.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Airoha SoC Subsystem Scale Driver
+
+maintainers:
+  - Christian Marangi <ansuelsmth@xxxxxxxxx>
+
+description:
+  Airoha SoC contains multiple subsystems that are scaled to a
+  specific OPP taking the CPU clock as reference. Such subsystem
+  can enter idle or performance state based on the system load
+  and power consumption conditions.
+
+  Example of such subsystems are GSW (Gigabit Switch), NPU (Custom
+  Risc Co-Processor for Network acceleration), SOE (Crypto Module) BUS...
+
+properties:
+  compatible:
+    const: airoha,an7581-subsystem-scale
+
+  clocks:
+    maxItems: 1
+
+  operating-points-v2:
+    description:
+      OPP table of the related subsystem supported rates that referenced
+      clocks will be scaled to.
+
+required:
+  - compatible
+  - clocks
+  - operating-points-v2
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/en7523-clk.h>
+
+    npu_opp_table: opp-table-npu {
+        compatible = "operating-points-v2";
+
+        npu_low: opp-400000000 {
+           opp-hz = /bits/ 64 <400000000>;
+        };
+
+        npu_high: opp-720000000 {
+           opp-hz = /bits/ 64 <720000000>;
+        };
+    };
+
+    emi_opp_table: opp-table-emi {
+        compatible = "operating-points-v2";
+
+        emi_low: opp-400000000 {
+            opp-hz = /bits/ 64 <400000000>;
+        };
+
+        emi_high: opp-540000000 {
+           opp-hz = /bits/ 64 <540000000>;
+        };
+    };
+
+    bus_opp_table: opp-table-bus {
+        compatible = "operating-points-v2";
+
+        bus_low: opp-200000000 {
+           opp-hz = /bits/ 64 <200000000>;
+        };
+
+        bus_high: opp-300000000 {
+           opp-hz = /bits/ 64 <300000000>;
+        };
+    };
+
+    gsw_opp_table: opp-table-gsw {
+        compatible = "operating-points-v2";
+
+        gsw_low: opp-200000000 {
+            opp-hz = /bits/ 64 <200000000>;
+        };
+
+        gsw_high: opp-500000000 {
+           opp-hz = /bits/ 64 <500000000>;
+        };
+    };
+
+    npu-subsystem {
+        compatible = "airoha,an7581-subsystem-scale";
+        operating-points-v2 = <&npu_opp_table>;
+        clocks = <&scuclk EN7523_CLK_NPU>;
+    };
+
+    emi-subsystem {
+        compatible = "airoha,an7581-subsystem-scale";
+        operating-points-v2 = <&emi_opp_table>;
+        clocks = <&scuclk EN7523_CLK_EMI>;
+    };
+
+    bus-subsystem {
+        compatible = "airoha,an7581-subsystem-scale";
+        operating-points-v2 = <&bus_opp_table>;
+        clocks = <&scuclk EN7523_CLK_BUS>;
+    };
+
+    gsw-subsystem {
+        compatible = "airoha,an7581-subsystem-scale";
+        operating-points-v2 = <&gsw_opp_table>;
+        clocks = <&scuclk EN7523_CLK_GSW>;
+    };
-- 
2.55.0