Subject: Re: Micrel Phy KSZ8031 clock select setting in dts

From: Oliver Graute <[email-masked]>
Date: Wed, 22 Jun 2016 10:18:06 +0200

On 21/06/16, Sascha Hauer wrote:
> On Mon, Jun 20, 2016 at 07:14:06PM +0200, Oliver Graute wrote:
> > On 20/06/16, Andrew Lunn wrote:
> > > > &fec1 {
> > > > 	pinctrl-names = "default";
> > > > 	pinctrl-0 = <&pinctrl_enet1>;
> > > > 	phy-mode = "rmii";
> > > > 	micrel,rmii-reference-clock-select-25-mhz;
> > > > 	clocks,rmii-ref;
> > > 
> > > You are adding phy properties, not MAC properties. Please put them in
> > > the phy node.
> > 
> > yes, you are right. I fixed this and added the clock like sascha and
> > sergei proposed. (thx to you all)
> > 
> > my dts node now looks like this:
> > 
> > &fec1 {
> > 	pinctrl-names = "default";
> > 	pinctrl-0 = <&pinctrl_enet1>;
> > 	phy-mode = "rmii";
> > 	status = "okay";
> > 
> > 	mdio {
> > 		#address-cells = <1>;
> > 		#size-cells = <0>;
> > 
> > 		ethphy0: ethernet-phy@0 {
> > 			compatible = "micrel,ksz8031";
> > 			micrel,rmii-reference-clock-select-25-mhz;
> > 			clocks = <&mdc>;
> > 			clock-names = "rmii-ref";
> > 			phy-handle = <&ethphy0>;
> > 			reg = <0>;
> > 		};
> > 
> > 	};
> > 
> > 	mdc: rmii-ref {
> > 		#clock-cells = <0>;
> > 		compatible ="fixed-clock";
> > 		clock-frequency = <50000000>;
> > 	};
> > };
> 
> To make that clear: Which phy do you have: KSZ8031RNL or KSZ8031RNLI?
> The former has 25MHz default input clock whereas the latter has 50MHz
> default input clock.

according the circuit diagram I have KSZ803RNLI.

> 
> I assume you have the KSZ8031RNL and use it with 50MHz (so the non
> default case), hence you have to set the KSZPHY_RMII_REF_CLK_SEL bit.
> The "micrel,rmii-reference-clock-select-25-mhz" means "Setting the bit
> selects 25MHz" which is not the case here, so you have to remove the
> property.

ok if I removing the property "micrel,rmii-reference-clock-select-25-mhz"
and removing my changes in micrel.c it now works as well.

> Could it be that your initial setting just did not work because of other
> mistakes, like no correct clock?

yes that was the case. Many thanks for the helpful notes.

Best Regards,

Oliver