[PATCH net-next v6 5/5] ARM: dts: aspeed: ast2600-evb: Configure RGMII delay for MAC

[Jacky Chou]

Hi Andrew,

Thank you for yor reply.

> On Mon, Mar 02, 2026 at 06:24:32PM +0800, Jacky Chou wrote:
> > This change sets the rx-internal-delay-ps and tx-internal-delay-ps
> > properties to control the RGMII signal delay.
> > The phy-mode for MAC0–MAC3 is updated to "rgmii-id" to enable TX/RX
> > internal delay on the PHY and disable the corresponding delay on the
> > MAC.
> >
> > Signed-off-by: Jacky Chou <jacky_chou@xxxxxxxxxxxxxx>
> > ---
> >  arch/arm/boot/dts/aspeed/aspeed-ast2600-evb.dts | 20
> > ++++++++++++++++----
> >  1 file changed, 16 insertions(+), 4 deletions(-)
> >
> > diff --git a/arch/arm/boot/dts/aspeed/aspeed-ast2600-evb.dts
> > b/arch/arm/boot/dts/aspeed/aspeed-ast2600-evb.dts
> > index 3f2ca9da0be2..a2a1c1dbb830 100644
> > --- a/arch/arm/boot/dts/aspeed/aspeed-ast2600-evb.dts
> > +++ b/arch/arm/boot/dts/aspeed/aspeed-ast2600-evb.dts
> > @@ -123,42 +123,54 @@ ethphy3: ethernet-phy@0 {
> >  &mac0 {
> >  	status = "okay";
> >
> > -	phy-mode = "rgmii-rxid";
> > +	phy-mode = "rgmii-id";
> >  	phy-handle = <&ethphy0>;
> >
> >  	pinctrl-names = "default";
> >  	pinctrl-0 = <&pinctrl_rgmii1_default>;
> > +
> > +	rx-internal-delay-ps = <0>;
> > +	tx-internal-delay-ps = <0>;
> 
> In the binding, you said these default to 0. So you don't need them.
> 
> It is also odd that rgmii-rxid becomes rmgii-id, yet both delays are 0?
> 
> What was the bootloader doing? This is worth a comment in the commit
> messages.
> 

Before this patch, aspeed-ast2600-evb.dts is an existed old dts in mainline kernel.
In this series, ftgmac100 for AST2600 will configure the MAC RGMII internal delay
via SCU register, so this patch is changing this dts as a NEW dts for driver to configure
RGMII delay from the properties of MAC nodes.

Old dts: generally, leak tx/rx-internal-delay-ps -> Calculate the RGMII delay that is configured
from bootloader and decide whether keep the original value

New dts: In AST2600, we expect the MAC node includes the rx/tx-internal-delay-ns properties
and the driver directly uses these properties to configure RGMII delay.

We hope this series can keep the old dts works fine and push the new mechanism for the
next generation, AST2700. So, in AST2700, if the rx/tx-internal-delay-ps are ZERO, it is 
unnecessary including these properties, according to the binding these default are ZERO.

Thanks,
Jacky