Re: [PATCH 4/6] dt-bindings: net: add hisilicon-femac

[Yang Xiwen]

On 2/16/2024 8:06 AM, Andrew Lunn wrote:
> > +  clocks:
> > +    minItems: 3
> > +    maxItems: 3
> > +
> > +  clock-names:
> > +    items:
> > +      - const: mac
> > +      - const: macif
> > +      - const: phy
> The C code has:
>
> +enum clk_type {
> +       CLK_MAC,
> +       CLK_BUS,
> +       CLK_PHY,
> +       CLK_NUM,
> +};
>
> Could you explain BUS vs macif?
To be honest, I don't know. "macif" is used by hisi-gmac driver, but in 
the TRM it's called "bus". So I guess it's just an alias? As you 
mentioned, I'll stick to macif everywhere, to keep sync with hisi-gmac 
driver.
> Also, what exactly is the PHY clock?
As the name suggests, it's not part of the mac controller actually, 
rather it's the clock of the internal PHY. The SoC (or the PHY/MAC, I 
don't know exactly which) is quirky that it is mandatory to disable PHY 
CLK before MAC reset or else the PHY won't work(see 
hisi_femac_phy_reset()). I can't find a better solution. Letting the 
ethernet controller manage all clocks and resets seems the easiest way 
to handle this quirk.
>        Andrew


--
Regards,
Yang Xiwen