Interfacing KSZ9477 switch to imx8mp

[vinay_hasyagar]

Hello,

We are using KSZ9477 switch in our design which is interfaced with imx8m plus SoC. The KSZ9477 port6 (RGMII) is connected to eqos MAC of imx8M plus. The switch is made to configure using MDIO mode. It is also mapped in the device tree. After OS gets booted, if we see the ethernet interfaces then we are able to see eth1 is listed. In the dmesg, I can see imx-dwmac driver is also loaded properly. There is one more external phy which is connected to FEC MAC of imx8m plus which is working properly.

The issue is, the IP is not getting assigned to eth1. Do I need to add any configuration with respect to KSZ9477? Please find the device tree mapping of KSZ9477.

&eqos {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_eqos>;
phy-mode = "rgmii";
phy-handle = <&ethphy0>;
status = "okay";

mdio {
compatible = "snps,dwmac-mdio";
#address-cells = <1>;
#size-cells = <0>;

ethphy0: ethernet-phy@1 {
compatible = "ethernet-phy-ieee802.3-c22";
reg = <1>;
eee-broken-1000t;
rtl821x,aldps-disable;
rtl821x,clkout-disable;
};
};

Please find the below block diagram which tells how switch is connected

The path RJ45--> KSZ9477--->KSZ9131(external phy)--->IMX8M plus is working.

The path RJ45--> KSZ9477--->IMX8M plus is not working because no IP address is getting assigned. Please tell me whether I need to add any configuration in device tree.

Thanks

[JorgeCas]

Hello,

Please check to this thread Using KSZ9031 PHY On i.MX8MM and L5.4.24_2.1.0, to use it as a reference.

Best regards.

[vinay_hasyagar]

Hi @JorgeCas 
Thank you for your reply. I went through the steps mentioned in the link and added the same thing. But that did not help. The product mentioned in the link is a phy and not an ethernet switch.

Thanks

[JorgeCas]

Hello,

Researching a little bit more, I found that there is no limitation for EQOS controller to implement the configuration with the switch. But since this is not part of the default BSP, it is up to the customer to make the integration. NXP BSP offers basic enablement features.

Best regards.