[PATCH 04/13] dt-bindings: soc: airoha: add Documentation for Airoha AN7581 SCU SSR

[Christian Marangi <ansuelsmth@gmail.com>]

The Airoha AN7581 SoC have in the SCU register space particular
address that control how some peripheral are configured.

These are toggeled in the System Status Register and are used to
toggle Serdes port for USB 3.0 mode or HSGMII, USB 3.0 mode or PCIe2
or setup port for PCIe mode or Ethrnet mode (HSGMII/USXGMII).

Modes are mutually exclusive and selecting one mode cause the
other feature to not work (example a mode in USB 3.0 cause PCIe
port 2 to not work) This depends also on what is physically
connected to the Hardware and needs to correctly reflect the
System Status Register bits.

Special care is needed for PCIe port 0 in 2 line mode that
requires both WiFi1 and WiFi2 Serdes port set to PCIe0 2 Line
mode.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
---
 .../soc/airoha/airoha,an7581-scu-ssr.yaml     | 106 ++++++++++++++++++
 MAINTAINERS                                   |   1 +
 2 files changed, 107 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/soc/airoha/airoha,an7581-scu-ssr.yaml

diff --git a/Documentation/devicetree/bindings/soc/airoha/airoha,an7581-scu-ssr.yaml b/Documentation/devicetree/bindings/soc/airoha/airoha,an7581-scu-ssr.yaml
new file mode 100644
index 000000000000..4bbf6e3b79a4
--- /dev/null
+++ b/Documentation/devicetree/bindings/soc/airoha/airoha,an7581-scu-ssr.yaml
@@ -0,0 +1,106 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/soc/airoha/airoha,an7581-scu-ssr.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Airoha AN7581 SCU System Status Register
+
+maintainers:
+  - Christian Marangi <ansuelsmth@gmail.com>
+
+description: >
+  The Airoha AN7581 SoC have in the SCU register space particular
+  address that control how some peripheral are configured.
+
+  These are toggeled in the System Status Register and are used to
+  toggle Serdes port for USB 3.0 mode or HSGMII, USB 3.0 mode or PCIe2
+  or setup port for PCIe mode or Ethrnet mode (HSGMII/USXGMII).
+
+  Modes are mutually exclusive and selecting one mode cause the
+  other feature to not work (example a mode in USB 3.0 cause PCIe
+  port 2 to not work) This depends also on what is physically
+  connected to the Hardware and needs to correctly reflect the
+  System Status Register bits.
+
+  Special care is needed for PCIe port 0 in 2 line mode that
+  requires both WiFi1 and WiFi2 Serdes port set to PCIe0 2 Line
+  mode.
+
+properties:
+  compatible:
+    const: airoha,an7581-scu-ssr
+
+  airoha,serdes-wifi1:
+    description: |
+      Configure the Wifi1 Serdes port for:
+      - 0: PCIe0 2 Line
+      - 1: PCIe0 1 Line
+      - 2: Ethernet modes (HSGMII/USXGMII)
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [0, 1, 2]
+    default: 1
+
+  airoha,serdes-wifi2:
+    description: |
+      Configure the Wifi2 Serdes port for:
+      - 0: PCIe0 2 Line
+      - 1: PCIe1 1 Line
+      - 2: Ethernet modes (HSGMII/USXGMII)
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [0, 1, 2]
+    default: 1
+
+  airoha,serdes-usb1:
+    description: |
+      Configure the USB1 Serdes port for:
+      - 0: USB 3.0
+      - 1: Ethernet modes (HSGMII)
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [0, 1]
+    default: 0
+
+  airoha,serdes-usb2:
+    description: |
+      Configure the USB2 Serdes port for:
+      - 0: USB 3.0
+      - 1: PCIe2 1 Line
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [0, 1]
+    default: 0
+
+required:
+  - compatible
+
+allOf:
+  - if:
+      properties:
+        airoha,serdes-wifi1:
+          const: 0
+    then:
+      properties:
+        airoha,serdes-wifi2:
+          const: 0
+
+  - if:
+      properties:
+        airoha,serdes-wifi2:
+          const: 0
+    then:
+      properties:
+        airoha,serdes-wifi1:
+          const: 0
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/soc/airoha,scu-ssr.h>
+
+    system-controller {
+      compatible = "airoha,an7581-scu-ssr";
+
+      airoha,serdes-wifi1 = <AIROHA_SCU_SSR_WIFI1_PCIE0_2LINE>;
+      airoha,serdes-wifi2 = <AIROHA_SCU_SSR_WIFI2_PCIE0_2LINE>;
+      airoha,serdes-usb2 = <AIROHA_SCU_SSR_USB2_PCIE2>;
+    };
diff --git a/MAINTAINERS b/MAINTAINERS
index d3125268d63f..9944845ae9f5 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -740,6 +740,7 @@ AIROHA SCU SSR DRIVER
 M:	Christian Marangi <ansuelsmth@gmail.com>
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
 S:	Maintained
+F:	Documentation/devicetree/bindings/soc/airoha/airoha,an7581-scu-ssr.yaml
 F:	include/dt-bindings/soc/airoha,scu-ssr.h
 
 AIROHA SPI SNFI DRIVER
-- 
2.48.1