Re: [PATCH v12 1/3] arm64: dts: rockchip: rk3568: add XPCS and fixed-clock nodes

[Heiko Stuebner <heiko@sntech.de>]

Hi,

Am Freitag, 23. Oktober 2026, 07:35:46 Mitteleuropäische Normalzeit schrieb Coia Prant:
> 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 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 is 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: boards that
> enable the XPCS must supply it, since the SerDes link is a board-level
> design choice (combphy1 on some boards, combphy2 on others).
> 
> Signed-off-by: Coia Prant <coiaprant@gmail.com>
> ---
>  arch/arm64/boot/dts/rockchip/rk3568.dtsi | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/rockchip/rk3568.dtsi b/arch/arm64/boot/dts/rockchip/rk3568.dtsi
> index 3bc653f027f1f..20a72785adbc2 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3568.dtsi
> +++ b/arch/arm64/boot/dts/rockchip/rk3568.dtsi
> @@ -8,6 +8,20 @@
>  / {
>  	compatible = "rockchip,rk3568";
>  
> +	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>;
> +	};
> +

these clocks don't belong here.

When you place these nodes in the main, they seem to come out of
thin air, while that might be true for some boards, that they
have dedicated oscillators for that, this will likely not be true
for all.

So these should be defined in the board dts, to match the actual
hardware.


Heiko