[PATCH] riscv: dts: sophgo: Add ethernet configuration for cv18xx

[Inochi Amaoto]

On Thu, Oct 31, 2024 at 02:04:31PM +0100, Andrew Lunn wrote:
> > > > > +		gmac0: ethernet at 4070000 {
> > > > > +			compatible = "snps,dwmac-3.70a";
> > > > > +			reg = <0x04070000 0x10000>;
> > > > > +			clocks = <&clk CLK_AXI4_ETH0>, <&clk CLK_ETH0_500M>;
> > > > > +			clock-names = "stmmaceth", "ptp_ref";
> > > > > +			interrupts = <31 IRQ_TYPE_LEVEL_HIGH>;
> > > > > +			interrupt-names = "macirq";
> > > > > +			phy-handle = <&phy0>;
> > > > > +			phy-mode = "rmii";
> > > > > +			rx-fifo-depth = <8192>;
> > > > > +			tx-fifo-depth = <8192>;
> > > > > +			snps,multicast-filter-bins = <0>;
> > > > > +			snps,perfect-filter-entries = <1>;
> > > > > +			snps,aal;
> > > > > +			snps,txpbl = <8>;
> > > > > +			snps,rxpbl = <8>;
> > > > > +			snps,mtl-rx-config = <&gmac0_mtl_rx_setup>;
> > > > > +			snps,mtl-tx-config = <&gmac0_mtl_tx_setup>;
> > > > > +			snps,axi-config = <&gmac0_stmmac_axi_setup>;
> > > > > +			status = "disabled";
> > > > > +
> > > > > +			mdio {
> > > > > +				compatible = "snps,dwmac-mdio";
> > > > > +				#address-cells = <1>;
> > > > > +				#size-cells = <0>;
> > > > > +
> > > > > +				phy0: phy at 0 {
> > > > > +					compatible = "ethernet-phy-ieee802.3-c22";
> > > > > +					reg = <0>;
> > > > > +				};
> > > > > +			};
> > > > 
> > > > It is not clear to me what cv18xx.dtsi represents, 
> > > 
> > > This is a include file to define common ip for the whole
> > > cv18xx series SoCs (cv1800b, cv1812h, sg2000, sg2000).
> > > 
> > > > and where the PHY node should be, here, or in a .dts file. 
> > > > Is this a SOM, and the PHY is on the SOM? 
> > > 
> > > The phy is on the SoC, it is embedded, and no external phy
> > > is supported. So I think the phy node should stay here, not 
> > > in the dts file.
> > 
> > There is a mistake, Some package supports external rmii/mii
> > phy. So I will move this phy definition to board specific.
> 
> When there is an external PHY, does the internal PHY still exists? If
> it does, it should be listed, even if it is not used.
> 
> Do the internal and external PHY share the same MDIO bus? 

They share the same MDIO bus and phy id setting. When an external phy
is select, the internal one is not initialized and can not be accessed
by the SoC.

> I've seen some SoCs with complex MDIO muxes for internal vs external
> PHYs.
> 
> 	Andrew

There is a switch register on the SoC to decide which phy/mode is used. 
By defaut is internal one with rmii mode. I think a driver is needed to
handle this properly.

Regards,
Inochi