Device tree configuration for Imx8M Plus with Ksz9563 ethernet switch

[gaurav_bankar]

Hii, 

   I am configuring ethernet switch ksz9563 from microchip in my i.mx8mp custom board. I have configured the switch in DTS as follows 

&fec {

pinctrl-names = "default";

pinctrl-0 = <&pinctrl_fec>;

phy-mode = "rgmii-id";

fsl,magic-packet;

status = "okay";

#phy-reset-duration = <20>;

#phy-reset-gpios = <&gpio4 2 GPIO_ACTIVE_LOW>;

#phy-reset-post-delay=<20>;

fixed-link {

speed = <1000>;

full-duplex;

};

mdio {

#address-cells = <1>;

#size-cells = <0>;

ksz9563: ksz9563@0 {

compatible = "microchip,ksz9893";

reg = <0>;

ports {

#address-cells = <1>;

#size-cells = <0>;

port@0 {

reg = <0>;

label = "eth1";

local-mac-address = [ 38 d5 47 00 2a ad];

};

port@1 {

reg = <1>;

label = "eth2";

local-mac-address = [ 38 d5 47 00 2a af];

};

port@2 {

reg = <2>;

label = "cpu";

ethernet = <&fec>;

fixed-link {

speed = <1000>;

full-duplex;

};

};

};

};

};

};

pinctrl 

pinctrl_fec: fecgrp {

fsl,pins = <

MX8MP_IOMUXC_SAI1_RXD7__ENET1_RGMII_RD3 0x91

MX8MP_IOMUXC_SAI1_RXD6__ENET1_RGMII_RD2 0x91

MX8MP_IOMUXC_SAI1_RXD5__ENET1_RGMII_RD1 0x91

MX8MP_IOMUXC_SAI1_RXD4__ENET1_RGMII_RD0 0x91

MX8MP_IOMUXC_SAI1_TXC__ENET1_RGMII_RXC 0x91

MX8MP_IOMUXC_SAI1_TXFS__ENET1_RGMII_RX_CTL 0x91

MX8MP_IOMUXC_SAI1_TXD3__ENET1_RGMII_TD3 0x1f

MX8MP_IOMUXC_SAI1_TXD2__ENET1_RGMII_TD2 0x1f

MX8MP_IOMUXC_SAI1_TXD1__ENET1_RGMII_TD1 0x1f

MX8MP_IOMUXC_SAI1_TXD0__ENET1_RGMII_TD0 0x1f

MX8MP_IOMUXC_SAI1_TXD5__ENET1_RGMII_TXC 0x1f

MX8MP_IOMUXC_SAI1_TXD4__ENET1_RGMII_TX_CTL 0x1f

MX8MP_IOMUXC_SAI1_RXD2__ENET1_MDC 0x3

MX8MP_IOMUXC_SAI1_RXD3__ENET1_MDIO 0x3

MX8MP_IOMUXC_SAI1_RXD1__GPIO4_IO03 0x19

MX8MP_IOMUXC_SAI1_RXD0__GPIO4_IO02 0x19

>;

};

Please note we are using mdio bus and not SPI/I2C. 

I am not able to get the switch to work.

After downloading the Image the dmesg are as follows 

 root@taswp500:~# dmesg | grep eth0
[ 0.994040] fec 30be0000.ethernet eth0: registered PHC device 0
[ 5.029033] fec 30be0000.ethernet eth0: Link is Up - 1Gbps/Full - flow control off
[ 6.046866] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready

ifconfig output is 

eth0 Link encap:Ethernet HWaddr CE:8F:BF:69:DE:9F
inet6 addr: fe80::cc8f:bfff:fe69:de9f/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:125 errors:0 dropped:0 overruns:0 frame:0
TX packets:22 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:8327 (8.1 KiB) TX bytes:3296 (3.2 KiB)

as I have configured two ports I only observe 1 port. That port is active but I am not able to assign an IPv4 address to it. 

I have referred these links/documents 

https://community.nxp.com/t5/i-MX-Processors/Device-tree-configuration-for-Imx8M-Nano-with-Ksz9893-e...

ksz.txt from linux-kernel/Documentation/devicetree/bindings/net/dsa

I have also attached the ethernet switch schematic. 
Please help me to make this work. 

[BhavinJoisar]

Hi @gaurav_bankar  were you able to solve the problem?

I am using ksz8794 in the MDIO mode as well and I have also created almost similar fec node as you.

&fec1{
	phy-mode = "rgmii-id";
	phy-handle = <&switch0port0>;
	pinctrl-names = "default";
	pinctrl-0 = <&pinctrl_fec1>;
	status = "okay";

	fixed-link {
		speed = <1000>;
		full-duplex;
	};

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

		ksz8794: ksz8794@0 {
			compatible = "microchip,ksz8794";
			reg = <0>;
			reset-gpios = <&gpio4 24 GPIO_ACTIVE_LOW>;
			ports {
				#address-cells = <1>;
				#size-cells = <0>;

			switch0port0:port@0 {
					reg = <0>;
					label = "cpu";
					ethernet = <&fec1>;

					fixed-link {
						speed = <1000>;
						full-duplex;
					};
				};

				port@1 {
					reg = <1>;
					label = "port1";

				};

				port@2 {
					reg = <2>;
					label = "port2";
				};

				port@3 {
					reg = <3>;
					label = "port3";
				};

				port@4 {
					reg = <4>;
					label = "port4";
				};

			};
		};
	};
};

And in dmesg I get the following logs

dmesg | grep "eth"
fec 30be0000.ethernet: Invalid MAC address: 00:00:00:00:00:00
fec 30be0000.ethernet: Using random MAC address: 1e:f5:75:fa:7b:78
fec 30be0000.ethernet eth0: registered PHC device 0
fec 30be0000.ethernet eth0: Unable to connect to phy
fec 30be0000.ethernet eth0: Unable to connect to phy


If you have successfully solved the issue can you please provide the solution

[Dhruvit]

Hi @gaurav_bankar,

I hope you are doing well.

Please refer to the below example for reference.

&ethernet0 {
status = "okay";
pinctrl-0 = <&ethernet0_rgmii_pins_a>;
pinctrl-1 = <&ethernet0_rgmii_pins_sleep_a>;
pinctrl-names = "default", "sleep";
phy-mode = "rgmii";
max-speed = <1000>;
phy-handle = <&phy0>;

mdio0 {
#address-cells = <1>;
#size-cells = <0>;
compatible = "snps,dwmac-mdio";
phy0: ethernet-phy@1 {
reg = <1>;
};
};
};

Please check this configuration is made for the ethernet node in the device tree.

Thanks & Regards,
Dhruvit Vasavada