[RFC PATCH v2 4/8] dt-bindings: net: pcs: add bindings for MediaTek USXGMII PCS

[Daniel Golle <daniel@makrotopia.org>]

MediaTek's USXGMII can be found in the MT7988 SoC. We need to access
it in order to configure and monitor the Ethernet SerDes link in
USXGMII, 10GBase-R and 5GBase-R mode. By including a wrapped
legacy 1000Base-X/2500Base-X/Cisco SGMII LynxI PCS as well, those
interface modes are also available.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
---
 .../bindings/net/pcs/mediatek,usxgmii.yaml    | 100 ++++++++++++++++++
 1 file changed, 100 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/pcs/mediatek,usxgmii.yaml

diff --git a/Documentation/devicetree/bindings/net/pcs/mediatek,usxgmii.yaml b/Documentation/devicetree/bindings/net/pcs/mediatek,usxgmii.yaml
new file mode 100644
index 0000000000000..9a798c0d2fdd7
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/pcs/mediatek,usxgmii.yaml
@@ -0,0 +1,100 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/net/pcs/mediatek,usxgmii.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MediaTek USXGMII PCS
+
+maintainers:
+  - Daniel Golle <daniel@makrotopia.org>
+
+description:
+  The MediaTek USXGMII PCS provides physical link control and status
+  for USXGMII, 10GBase-R and 5GBase-R links on the SerDes interfaces
+  provided by the PEXTP PHY.
+  In order to also support legacy 2500Base-X, 1000Base-X and Cisco
+  SGMII an existing mediatek,*-sgmiisys LynxI PCS is wrapped to
+  provide those interfaces modes on the same SerDes interfaces shared
+  with the USXGMII PCS.
+
+properties:
+  $nodename:
+    pattern: "^pcs@[0-9a-f]+$"
+
+  compatible:
+    const: mediatek,mt7988-usxgmiisys
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    items:
+      - description: USXGMII top-level clock
+      - description: SGMII top-level clock
+      - description: SGMII subsystem TX clock
+      - description: SGMII subsystem RX clock
+      - description: XFI PLL clock
+
+  clock-names:
+    items:
+      - const: usxgmii
+      - const: sgmii_sel
+      - const: sgmii_tx
+      - const: sgmii_rx
+      - const: xfi_pll
+
+  phys:
+    items:
+      - description: PEXTP SerDes PHY
+
+  mediatek,sgmiisys:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description:
+      Phandle to the syscon node of the corresponding SGMII LynxI PCS.
+
+  resets:
+    items:
+      - description: XFI reset
+      - description: SGMII reset
+
+  reset-names:
+    items:
+      - const: xfi
+      - const: sgmii
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - phys
+  - mediatek,sgmiisys
+  - resets
+  - reset-names
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/mediatek,mt7988-clk.h>
+    #include <dt-bindings/reset/mediatek,mt7988-resets.h>
+    soc {
+      #address-cells = <2>;
+      #size-cells = <2>;
+        usxgmiisys0: pcs@10080000 {
+          compatible = "mediatek,mt7988-usxgmiisys";
+          reg = <0 0x10080000 0 0x1000>;
+          clocks = <&topckgen CLK_TOP_USXGMII_SBUS_0_SEL>,
+                   <&topckgen CLK_TOP_SGM_0_SEL>,
+                   <&sgmiisys0 CLK_SGM0_TX_EN>,
+                   <&sgmiisys0 CLK_SGM0_RX_EN>,
+                   <&xfi_pll CLK_XFIPLL_PLL_EN>;
+          clock-names = "usxgmii", "sgmii_sel", "sgmii_tx", "sgmii_rx", "xfi_pll";
+          resets = <&watchdog MT7988_TOPRGU_XFI0_GRST>,
+                   <&watchdog MT7988_TOPRGU_SGMII0_GRST>;
+          reset-names = "xfi", "sgmii";
+          phys = <&xfi_pextp0>;
+          mediatek,sgmiisys = <&sgmiisys0>;
+        };
+    };
-- 
2.43.0