AM625: Ethernet switch LAN9374 bring up with the AM625

Hello, 

Apologies for the delayed response. 

Can you please point out specifically which thread you are seeing others using dual_emac for integrating extenral switch with AM625? This would help us understand the context what worked or not.

-Daolin

Hi Daolin Qiu ,

Please check the below link:

e2e.ti.com/.../5999472

The additional information related to issue is available on this like DTS and configuration  AM625: How to add LAN9374 with AM625 in kernel - Processors forum - Processors - TI E2E support forums and the HW connection is same as BEN has on RE: AM625: Ethernet switch connection to RGMII 2  

I am attaching zip file of device tree files we are using for refer.

 am62_lan9374_dts_dtsi_files.zip

Hello Naveenkumar and tv310, 

naveenkumar Muthusamy said:

i have seen  that some users are able to make it work using dual_emac, can you provide details regarding enabling dual_emac?

naveenkumar Muthusamy said:

Please check the below link:

e2e.ti.com/.../5999472

I believe that Ben in the other thread had mentioned "The only required modification on the TI side is a kernel patch to allow the switch to logically connect to an Ethernet MAC device other than the first available node (i.e. to select RGMII 2 in our case)." indicating that they are also facing a similar issue to connecting to the 2nd RGMII connection similar to the problem you are seeing. To my understanding it doesn't seem like they have gotten past this issue yet. 

Currently, we don't have a way to replicate this issue and determine what change is needed as TI EVMs don't have a way to connect to an external switch. We can only offer suggestions as we think of them.

One suggestion I had given but I do not if it was tested in the other thread is the below

As something to try, can you try changing swapping the cpsw_port1 and cpsw_port2 in the aliases property of your DTS? The idea is to try and see if we can "trick" the Kernel to view cpsw_port2 as eth0 instead. This might not work but I think it's something quick to test out. 

Take for example the below k3-am642-evm.dts (for the TI AM64x EVM).

// SPDX-License-Identifier: GPL-2.0-only OR MIT
/*
 * Copyright (C) 2020-2024 Texas Instruments Incorporated - https://www.ti.com/
 */

/dts-v1/;

#include <dt-bindings/phy/phy.h>
#include <dt-bindings/leds/common.h>
#include <dt-bindings/gpio/gpio.h>
#include <dt-bindings/net/ti-dp83867.h>
#include "k3-am642.dtsi"

#include "k3-serdes.h"
#include "k3-timesync-router.h"

/ {
	compatible = "ti,am642-evm", "ti,am642";
	model = "Texas Instruments AM642 EVM";

	chosen {
		stdout-path = &main_uart0;
	};

	aliases {
		serial0 = &mcu_uart0;
		serial1 = &main_uart1;
		serial2 = &main_uart0;
		serial3 = &main_uart3;
		i2c0 = &main_i2c0;
		i2c1 = &main_i2c1;
		mmc0 = &sdhci0;
		mmc1 = &sdhci1;
		ethernet0 = &cpsw_port2; <----changed from &cpsw_port1 to &cpsw_port2
		ethernet1 = &cpsw_port1; <----changed from &cpsw_port2 to &cpsw_port1
		ethernet2 = &icssg1_emac0;
	};

Hi Daolin , We already tested this before. No succes :(

Thanks :) Hope we will have solution soon.