[PATCH 2/2] arm64: dts: rockchip: Add rk3399-evb-ind board

[Andrew Lunn]

On Mon, Apr 28, 2025 at 09:47:34AM +0800, Chaoyi Chen wrote:
> Hi Andrew,
> 
> On 2025/4/28 4:42, Andrew Lunn wrote:
> > > +&gmac {
> > > +	assigned-clocks = <&cru SCLK_RMII_SRC>;
> > > +	assigned-clock-parents = <&clkin_gmac>;
> > > +	pinctrl-names = "default";
> > > +	pinctrl-0 = <&rgmii_pins>;
> > > +	clock_in_out = "input";
> > > +	phy-supply = <&vcc_phy>;
> > > +	phy-mode = "rgmii";
> > Does the PCB have extra long clock lines to implement the RGMII 2ns
> > delay?
> The 2ns delay of RGMII is implemented inside the RK3399 chip instead of PCB
> lines, and there are also additional delayline configurations.

If the PCB does not implement the delay, rgmii is wrong.

If the MAC/PHY pair is implementing the delay, you need to use
rgmii-id. You can then use additional properties to fine tune the
delay the MAC/PHY is adding. And the Linux preference is that the PHY
adds the delay.

	Andrew