Re: [PATCH v1 05/20] ARM: dts: imx6qdl: use enet_clk_ref instead of enet_out for the FEC node

[Peng Fan]

On 1/16/2023 1:26 PM, Oleksij Rempel wrote:
> On Mon, Jan 16, 2023 at 09:01:08AM +0800, Peng Fan wrote:
> > Hi Oleksij,
> >
> > On 1/13/2023 10:27 PM, Oleksij Rempel wrote:
> > > Old imx6q machine code makes RGMII/RMII clock direction decision based on
> > > configuration of "ptp" clock. "enet_out" is not used and make no real
> > > sense, since we can't configure it as output or use it as clock
> > > provider.
> > >
> > > Instead of "enet_out" use "enet_clk_ref" which is actual selector to
> > > choose between internal and external clock source:
> > >
> > > FEC MAC <---------- enet_clk_ref <--------- SoC PLL
> > >                            \
> > > 			  ^------<-> refclock PAD (bi directional)
> > >
> > > Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
> > > ---
> > >    arch/arm/boot/dts/imx6qdl.dtsi | 4 ++--
> > >    1 file changed, 2 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/arch/arm/boot/dts/imx6qdl.dtsi b/arch/arm/boot/dts/imx6qdl.dtsi
> > > index ff1e0173b39b..71522263031a 100644
> > > --- a/arch/arm/boot/dts/imx6qdl.dtsi
> > > +++ b/arch/arm/boot/dts/imx6qdl.dtsi
> > > @@ -1050,8 +1050,8 @@ fec: ethernet@2188000 {
> > >    				clocks = <&clks IMX6QDL_CLK_ENET>,
> > >    					 <&clks IMX6QDL_CLK_ENET>,
> > >    					 <&clks IMX6QDL_CLK_ENET_REF>,
> > > -					 <&clks IMX6QDL_CLK_ENET_REF>;
> > > -				clock-names = "ipg", "ahb", "ptp", "enet_out";
> > > +					 <&clks IMX6QDL_CLK_ENET_REF_SEL>;
> > > +				clock-names = "ipg", "ahb", "ptp", "enet_clk_ref";
> >
> >
> > Please also update fec binding, otherwise there will be dtbs check error.
>
> Hm, there is no restriction on enet_clk_ref use or requirements to use
> enet_out in Documentation/devicetree/bindings/net/fsl,fec.yaml
>
> Do I missing something?

After check, seems using enet_out would trigger dtbs_check error, using
enet_clk_ref would not as what you did in this patch. So your patch is fine.

  clock-names:
    minItems: 2
    maxItems: 5
    items:
      enum:
        - ipg
        - ahb
        - ptp
        - enet_clk_ref
        - enet_out
        - enet_2x_txclk

Regards,
Peng.


> Regards,
> Oleksij