[PATCH net-next v9 05/11] arm64: dts: rockchip: rk3568: add XPCS and fixed-clock nodes

From: Coia Prant

Date: Sun Sep 20 2026 - 13:07:11 EST


The RK3568 SoC integrates a Synopsys DesignWare XPCS that provides
the Physical Coding Sublayer for 1000BASE-X, SGMII, and QSGMII
interfaces via its four MII ports. Add the XPCS device node and
its pcs-mii sub-nodes to the SoC device tree.

The XPCS device is accessed via the APB3 bus at 0xfda00000 and
requires the CSR clock (PCLK_XPCS) for register access and the EEE
clock (CLK_XPCS_EEE) for Energy Efficient Ethernet operation. The
PD_PIPE power domain must be enabled before any register access.

Also add two fixed-clock nodes (clock-xpcs-gmac0 and clock-xpcs-gmac1,
labelled clk_gmac0_xpcs_mii and clk_gmac1_xpcs_mii) providing the
125 MHz reference clock for the GMACs when operating with XPCS. Their
clock-output-names match the CRU mux parent names in clk-rk3568.c, so
boards can reparent SCLK_GMAC0_RX_TX / SCLK_GMAC1_RX_TX through
assigned-clock-parents.

The XPCS node and its mii sub-nodes are disabled by default and
must be enabled at the board level when 1000BASE-X/SGMII/QSGMII is
in use. The fixed-clock nodes are always present and do not have a
status property, as they are static clock sources.

The XPCS node requires a reference to the appropriate Naneng Combo PHY
via the phys property. dtbs_check only validates required properties
for enabled nodes, so the SoC dtsi does not provide phys/phy-names:
boards that enable the XPCS must supply them, since the SerDes link is
a board-level design choice (combphy1 on some boards, combphy2 on
others).

Signed-off-by: Coia Prant <coiaprant@xxxxxxxxx>
---
arch/arm64/boot/dts/rockchip/rk3568.dtsi | 45 ++++++++++++++++++++++++
1 file changed, 45 insertions(+)

diff --git a/arch/arm64/boot/dts/rockchip/rk3568.dtsi b/arch/arm64/boot/dts/rockchip/rk3568.dtsi
index 3bc653f027f1f..227d03e336043 100644
--- a/arch/arm64/boot/dts/rockchip/rk3568.dtsi
+++ b/arch/arm64/boot/dts/rockchip/rk3568.dtsi
@@ -110,6 +110,51 @@ sata0: sata@fc000000 {
status = "disabled";
};

+ xpcs: ethernet-pcs@fda00000 {
+ compatible = "rockchip,rk3568-xpcs";
+ #address-cells = <1>;
+ #size-cells = <0>;
+ reg = <0x0 0xfda00000 0x0 0x200000>;
+ clocks = <&cru PCLK_XPCS>, <&cru CLK_XPCS_EEE>;
+ clock-names = "csr", "eee";
+ power-domains = <&power RK3568_PD_PIPE>;
+ status = "disabled";
+
+ xpcs_mii0: ethernet-pcs-mii@0 {
+ reg = <0>;
+ status = "disabled";
+ };
+
+ xpcs_mii1: ethernet-pcs-mii@1 {
+ reg = <1>;
+ status = "disabled";
+ };
+
+ xpcs_mii2: ethernet-pcs-mii@2 {
+ reg = <2>;
+ status = "disabled";
+ };
+
+ xpcs_mii3: ethernet-pcs-mii@3 {
+ reg = <3>;
+ status = "disabled";
+ };
+ };
+
+ clk_gmac0_xpcs_mii: clock-xpcs-gmac0 {
+ compatible = "fixed-clock";
+ clock-frequency = <125000000>;
+ clock-output-names = "clk_gmac0_xpcs_mii";
+ #clock-cells = <0>;
+ };
+
+ clk_gmac1_xpcs_mii: clock-xpcs-gmac1 {
+ compatible = "fixed-clock";
+ clock-frequency = <125000000>;
+ clock-output-names = "clk_gmac1_xpcs_mii";
+ #clock-cells = <0>;
+ };
+
pipe_phy_grf0: syscon@fdc70000 {
compatible = "rockchip,rk3568-pipe-phy-grf", "syscon";
reg = <0x0 0xfdc70000 0x0 0x1000>;
--
2.47.3