回覆: [net-next 4/4] net: ftgmac100: add RGMII delay for AST2600
From: Jacky Chou
Date: Mon Mar 17 2025 - 07:34:35 EST
> > So this goes completely against the naming of the property. It has the
> > -ps suffix, so you would expect to have picoseconds values passed, and
> > not an arbiraty index.
> >
> > Take a look at other drivers, you should accept picseconds values from
> > these properties, then compute the relevant index in the driver. That
> > index should be something internal to your driver.
> >
> > An example here :
> >
> > https://elixir.bootlin.com/linux/v6.14-rc6/source/drivers/net/ethernet
> > /microchip/sparx5/lan969x/lan969x_rgmii.c#L51
>
> Another example would be drivers/net/phy/adin.c::adin_get_reg_value()
> and associated functions - these lookup a DT property and then look that up in
> a table to convert it to a register value.
>
> I suspect that's something which could become generic, as I suspect most
> hardware isn't going to accept a picosecond value, but be a choice of N
> different options.
Thank you for your information.
The RGMII delay of AST2600 has a lot of steps can be configured.
And the delay value of each MAC has different.
Each MAC has 64 steps to configure RGMII TX/RX delay.
Therefore, I use these properties as index to configure the register to reduce
computing in driver.
Or I do not use the property that defined in ethernet-controller.yaml, I
create the property that defined by myself?
Thanks,
Jacky