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

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

Example of such subsystem 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 + devfreq nodes.

Signed-off-by: Christian Marangi <[email protected]>
---
 .../bindings/devfreq/airoha,devfreq.yaml      | 114 ++++++++++++++++++
 1 file changed, 114 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/devfreq/airoha,devfreq.yaml

diff --git a/Documentation/devicetree/bindings/devfreq/airoha,devfreq.yaml b/Documentation/devicetree/bindings/devfreq/airoha,devfreq.yaml
new file mode 100644
index 000000000000..2f84486cb209
--- /dev/null
+++ b/Documentation/devicetree/bindings/devfreq/airoha,devfreq.yaml
@@ -0,0 +1,114 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/devfreq/airoha,devfreq.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Airoha SoC Subsystem Devfreq
+
+maintainers:
+  - Christian Marangi <[email protected]>
+
+description:
+  Airoha SoC contains multiple subsystem that are scaled to a
+  specific OPP taking the CPU clock as reference. Such sybsystem
+  can enter idle or performance state based on the system load
+  and power consumption conditions.
+
+  Example of such subsystem are GSW (Gigabit Switch), NPU (Custom
+  Risc Co-Processor for Network acceleration), SOE (Crypto Module) BUS...
+
+properties:
+  compatible:
+    const: airoha,devfreq
+
+  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-devfreq {
+        compatible = "airoha,devfreq";
+        operating-points-v2 = <&npu_opp_table>;
+        clocks = <&scuclk EN7523_CLK_NPU>;
+    };
+
+    emi-devfreq {
+        compatible = "airoha,devfreq";
+        operating-points-v2 = <&emi_opp_table>;
+        clocks = <&scuclk EN7523_CLK_EMI>;
+    };
+
+    bus-devfreq {
+        compatible = "airoha,devfreq";
+        operating-points-v2 = <&bus_opp_table>;
+        clocks = <&scuclk EN7523_CLK_BUS>;
+    };
+
+    gsw-devfreq {
+        compatible = "airoha,devfreq";
+        operating-points-v2 = <&gsw_opp_table>;
+        clocks = <&scuclk EN7523_CLK_GSW>;
+    };
-- 
2.53.0