How to configure Ethernet switch

Applicable for

STM32MP25x lines

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1. Purpose

This article describes how to configure the Ethernet switch.

2. For GMAC standalone configuration

100% same sequence than MP1

3. For Switch configuration

ETH1  Stm32-deip glue  edge-lkml File describing the probe scheme are located on board in:

 /etc/modprobe.d/edgx_sw_modprobe.cnf
 /etc/modprobe.d/acm_modprobe.cnf

During edge-lkml probe, the interface on which the switch internal port is connected is given as parameter:

 Ex: edgx_pfm_lkm netif="end1:0"
 In: /etc/modprobe.d/edgx_sw_core.conf

3.1. Ethernet switch interface

Ethernet Switch interfaces

Use ifconfig to list interfaces:

end0: standalone GMAC interface

end1: SW interface for ETH1 GMAC Connected to switch internal port Will not have IP address!

Sw0p1: Internal port interface Will not have IP address!

Sw0p2: External port interface connected to ETH3 port Will not have IP address!

Sw0p3: External port interface connected to ETH1 port Will not have IP address!

Sw0ep: « endpoint » interface Used to communicate to/from the MP25 through external ports

Those interfaces are set during boot thanks to this script: /usr/sbin/ttt-ip-init-systemd.sh

3.1.1. more details about /usr/sbin/ttt-ip-init-systemd.sh

Bridge setup (as described above)

Services startup:

• Start deptp:

   proprietary PTP stack provided by TTTech used for gPTP synchronization

• Start LLDP (Link Layer Discovery Protocol):

   Use to exchange informations (name, capabilities) with other connected devices

• Start SNMPD:

   Use to collect data from the switch

• Configure MSTP (through « mstpctl »)

   Used for spanning tree management (to avoid loop in a network)

• PHY configuration:

   Affect PHY to the well switch port:
     echo -n stmmac-1:05 > /sys/devices/platform/soc/$IP_REF_NAME/net/sw0p3/phy/mdiobus
     echo -n stmmac-1:04 > /sys/devices/platform/soc/$IP_REF_NAME/net/sw0p2/phy/mdiobus
     (ls –al /sys/bus/mdio_bus/devices/ to know which mdio bus refers to GMAC ETH1)

Warning

This has to be updated for customer PHY

• Add phy delays:

   Used by the switch to compute his propagation delay (used for gPTP)
    echo 84 > /sys/class/net/sw0p2/phy/delay1000tx_min     
    echo 92 > /sys/class/net/sw0p2/phy/delay1000tx_max                     
    echo 84 > /sys/class/net/sw0p3/phy/delay1000tx_min                          
    echo 92 > /sys/class/net/sw0p3/phy/delay1000tx_max                                    
    echo 0 > /sys/class/net/sw0p2/phy/delay1000rx_min                                     
    echo 250 > /sys/class/net/sw0p2/phy/delay1000rx_max                                   
    echo 0 > /sys/class/net/sw0p3/phy/delay1000rx_min                                     
    echo 250 > /sys/class/net/sw0p3/phy/delay1000rx_max

Warning

Value to be found in PHY datasheet

Warning

100 Mbps values are currently missing

Physical layer protocol