[EXT] Re: [PATCH V2 3/3] arm64: dts: imx8ulp-evk: Add the fec support

[Wei Fang]

> -----Original Message-----
> From: Andrew Lunn <andrew at lunn.ch>
> Sent: 2022年7月11日 15:02
> To: Wei Fang <wei.fang at nxp.com>
> Cc: davem at davemloft.net; edumazet at google.com; kuba at kernel.org;
> pabeni at redhat.com; robh+dt at kernel.org; krzysztof.kozlowski+dt at linaro.org;
> shawnguo at kernel.org; s.hauer at pengutronix.de; netdev at vger.kernel.org;
> devicetree at vger.kernel.org; linux-kernel at vger.kernel.org;
> kernel at pengutronix.de; festevam at gmail.com; dl-linux-imx
> <linux-imx at nxp.com>; Peng Fan <peng.fan at nxp.com>; Jacky Bai
> <ping.bai at nxp.com>; sudeep.holla at arm.com;
> linux-arm-kernel at lists.infradead.org; Aisheng Dong <aisheng.dong at nxp.com>
> Subject: [EXT] Re: [PATCH V2 3/3] arm64: dts: imx8ulp-evk: Add the fec
> support
> 
> Caution: EXT Email
> 
> On Mon, Jul 11, 2022 at 07:44:34PM +1000, Wei Fang wrote:
> > Enable the fec on i.MX8ULP EVK board.
> >
> > Signed-off-by: Wei Fang <wei.fang at nxp.com>
> > ---
> > V2 change:
> > Add clock_ext_rmii and clock_ext_ts. They are both related to EVK board.
> > ---
> >  arch/arm64/boot/dts/freescale/imx8ulp-evk.dts | 57
> > +++++++++++++++++++
> >  1 file changed, 57 insertions(+)
> >
> > diff --git a/arch/arm64/boot/dts/freescale/imx8ulp-evk.dts
> > b/arch/arm64/boot/dts/freescale/imx8ulp-evk.dts
> > index 33e84c4e9ed8..ebce716b10e6 100644
> > --- a/arch/arm64/boot/dts/freescale/imx8ulp-evk.dts
> > +++ b/arch/arm64/boot/dts/freescale/imx8ulp-evk.dts
> > @@ -19,6 +19,21 @@ memory at 80000000 {
> >               device_type = "memory";
> >               reg = <0x0 0x80000000 0 0x80000000>;
> >       };
> > +
> > +     clock_ext_rmii: clock-ext-rmii {
> > +             compatible = "fixed-clock";
> > +             clock-frequency = <50000000>;
> > +             clock-output-names = "ext_rmii_clk";
> > +             #clock-cells = <0>;
> > +     };
> > +
> > +     clock_ext_ts: clock-ext-ts {
> > +             compatible = "fixed-clock";
> > +             /* External ts clock is 50MHZ from PHY on EVK board. */
> > +             clock-frequency = <50000000>;
> > +             clock-output-names = "ext_ts_clk";
> > +             #clock-cells = <0>;
> > +     };
> 
> Do you need any PHY properties to turn this clock on? Or is it strapped to be
> always on?
> 
Yes, the clock is strapped to be always on, so any PHY property is not required.

> I'm surprised it is limited to Fast Ethernet. I know the Vybrid and some of the
> older SoCs are Fast Ethernet only, but i thought all the newer supported 1G?
> 
>          Andrew

The FEC of imx8ulp is reused from imx6ul , it supports 10/100 Mbit/s full-duplex and configurable half-duplex operation, do not support 1G.