ENET1 interface on Colibri IMX8 SOM


I am trying to get external Ethernet RGMII PHY working (ENET1 pins) on our custom carrier board. I am suspecting Power supply of ENET1 ethernet IOs, VDD_ESAI_SPDIF_1P8_2P5_3P3, ball N25 is not provided or enabled. I do not have Colibri SOM schematics to check.

Would you be able to check if IMX8 ball N25 is routed to somewhere? Some ext. LDO or PMIC power rail?

Thank you in advance.

N25 ball connected directly to common V3.3 rail.

Best regards,

We have a similar setup and trying to connect an RMII PHY (a TJA1100 for BroadR-Reach) to ENET1 on a custom board. We can talk to the chip via the management bus, have verified the link status etc., so the physical side looks fine.

The PHY tries to send data from the network to the SOM - we see activity on the RX lines when the SOM is not in the socket, but when it is powered up, no activity can be measured on the RX nor TX lines (when pinging the other party, for example).

Based on what I found in fsl-imx8qxp-enet2-tja1100.dtsi, I adapted the device-tree to look like this (fsl-imx8qxp-colibri.dtsi):

&fec2 {
       	pinctrl-names = "default";
	pinctrl-0 = <&pinctrl_fec2_rmii>;
	clocks = <&clk IMX8QXP_ENET1_IPG_CLK>,
                 <&clk IMX8QXP_ENET1_AHB_CLK>,
		 <&clk IMX8QXP_ENET1_REF_50MHZ_CLK>,
                 <&clk IMX8QXP_ENET1_PTP_CLK>,
                 <&clk IMX8QXP_ENET1_TX_CLK>;
	phy-mode = "rmii";
        phy-handle = <&ethphy1>;
        /delete-property/ phy-supply;

	mdio {
                #address-cells = <1>;
  		#size-cells = <0>;

                ethphy1: ethernet-phy@4 {
			compatible = "ethernet-phy-ieee802.3-c22";
			reg = <4>;
                        max-speed = <100>;

and (fsl-imx8qxp-colibri-eval-v3.dts)

/* Colibri Ethernet */
//&fec1 {
//      status = "okay";
&fec2 {
        status = "okay";

I fear I am missing something obvious - is there a power domain that needs to be switched on explicitity in addition?

BR Simon

Please do not hijack a tread. Could you create a new post with your question?

Sorry, no offence meant - it just seemed highly related. I’ve replicated the issue here: https://www.toradex.com/community/questions/56457/interfacing-an-external-phy-tja1100-via-rmii-to-th.html

Thanks for your understanding and posting the new question. We will continue the discussion there.