Re: [PATCH v2 05/10] arm64: dts: rockchip: rk3568: add XPCS and fixed-clock nodes

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 (xpcs_gmac0_clk and xpcs_gmac1_clk)
providing the 125 MHz reference clock for the GMACs when operating
with XPCS.  These clocks are used as the assigned-clock-parents
for the respective GMAC nodes in board-level device trees.

The XPCS node and its pcs-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 also requires a reference to the appropriate Naneng
Combo PHY via the phys property at the board level.

Signed-off-by: Coia Prant <redacted>
---
 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..989e164c0eb39 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: 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: pcs-mii@0 {
+			reg = <0>;
+			status = "disabled";
+		};
+
+		xpcs_mii1: pcs-mii@1 {
+			reg = <1>;
+			status = "disabled";
+		};
+
+		xpcs_mii2: pcs-mii@2 {
+			reg = <2>;
+			status = "disabled";
+		};
+
+		xpcs_mii3: pcs-mii@3 {
+			reg = <3>;
+			status = "disabled";
+		};
+	};
+
+	xpcs_gmac0_clk: xpcs-gmac0-clock {
+		compatible = "fixed-clock";
+		clock-frequency = <125000000>;
+		clock-output-names = "clk_gmac0_xpcs_mii";
+		#clock-cells = <0>;
+	};
+
+	xpcs_gmac1_clk: xpcs-gmac1-clock {
+		compatible = "fixed-clock";
+		clock-frequency = <125000000>;
+		clock-output-names = "clk_gmac1_xpcs_mii";
+		#clock-cells = <0>;
+	};