Feedback on devicetree for imx6qdl connecting to Marvell 6176 DSA networking switch

[schadalavada]

Please give feed back on device tree description for

This node in the device tree with CONFIG_NET_DSA_LEGACY enabled in kernel correctly enumerates all interfaces on the Marvell 6176 switch.

dsa@0 {
compatible = "marvell,mv88e6085";
#address-cells = <2>;
#size-cells = <0>;
interrupt-parent = <&gpio2>;
interrupts = <&gpio2 31 IRQ_TYPE_LEVEL_LOW>;
dsa,ethernet = <&eth0>;

switch@0 { #address-cells = <1>; #size-cells = <0>; reg = <0 0>; port@0 { reg = <0>; label = "port0"; }; port@1 { reg = <1>; label = "port1"; }; port@2 { reg = <2>; label = "port2"; }; port@5 { reg = <5>; label = "cpu"; };

BUT this attempt with the new binding causes Linux 4.19 kernel to NOT detect the Marvell 6176 switch and NOT enumerate its ports.

mdio {
       #address-cells = <2>;
       #size-cells = <0>;
       status = "okay";
       switch0: switch0@0 {

               compatible = "marvell,mv88e6085";
               reg = <0 0>;
               interrupt-parent = <&gpio2>;
               interrupts = <31 IRQ_TYPE_LEVEL_LOW>;
               dsa,member = <0 0>;
               ports{

                     #address-cells = <1>;
                     #size-cells = <0>;
                     port@0 {
                           reg = <0>;
                           label = "port0";
                      };

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

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

                     port@5 {
                           reg = <5>;
                           label = "cpu";
                           ethernet = <&eth0>;
                     };
               };
            };
};

[jimmychan]

How you connect the i.MX6Q to the Marvell 6176?

[schadalavada]

Hi Jimmychan,

   Are you able to see the hardware block diagram? Please let me know if you have any questions after viewing that. Thanks.

[jimmychan]

I can see the block diagram. I want to know which interface of i.MX6Q you used and how the signals connected?

For your reference. https://community.nxp.com/thread/513481 

[schadalavada]

Hi Jimmychan,

  We are using a PEX 8065 PCI Express 4 port Gen2 switch. Port 0 of that switch is connected to imx6, port 1 to Intel Gigabit Ethernet Controller. Thanks for the link but our problem is different. The Marvell 6176 switch is connected to Intel Gigabit Ethernet Controller rather than directly to i.MX6 directly. 

[jimmychan]

Hi,

So you connect the switch to i.mX6q pcie. Do you setup the pcie in device tree file? And select the corresponding driver in the kernel menuconfig?

[schadalavada]

Yes to both answers. Now I'm able to detect the Marvell 6176 switch with the following device tree entry but its ports are still not enumerated by ifconfig.

pcie@2,1 {
/* Connection to  */
status = "okay";
fsl,max-link-speed = <1>;
pcie@3,0 {
/* The Intel Gigabit Ethernet Controller*/
status = "okay";
fsl,max-link-speed = <1>;
eth0: igb0 {
compatible = "intel,igb";
/* SC: New binding for the Marvell 6176 switch attached to the Intel Gigabit Ethernet Controller
via SERDES link */
mdio1: mdio@0 {
#address-cells = <2>;
#size-cells = <0>;
status = "okay";
switch0: switch0@0 {

compatible = "marvell,mv88e6085";
reg = <0 0>;
interrupt-parent = <&gpio2>;
interrupts = <31 IRQ_TYPE_LEVEL_LOW>;
dsa,member = <0 0>;
mdio2: mdio@1{
ports
{

#address-cells = <1>;
#size-cells = <0>;
port@0 {
reg = <0>;
label = "port0";
};

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

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

port@5 {
reg = <5>;
label = "cpu";
ethernet = <&eth0>;
};
};
};
mdio3: mdio@2{/* External configuration MDIO bus between Intel Gigabit Ethernet Controller and 6176. Followed example in Documentation/devicetree/bindings/dsa /marvell.txt*/
compatible = "marvell,mv88e6xxx-mdio-external";
#address-cells = <1>;
#size-cells = <0>;
};
};
};
};
};

};