[FAQ] LP-AM261: Running gPTP TimeSync applications on AM261x LaunchPad

On AM261x-LP PROC E1 and PROC E2 revisions, there are known connectivity issues in RMII interface. When testing using the DP83826 Industrial Add-on-PHY, It is recommended to try it in 100M MII interface mode. This needs some basic changes and checks in the SDK.

Step-1: In the following file (mcu_plus_sdk_am261x_10_02_00_15\source\networking\tsn\tsn-stack\tsn_combase\tilld\sitara\lldenet.c), replace the function (LLDEnetGetLinkInfo()) with the below definition, to enable MII mode support.

int LLDEnetGetLinkInfo(LLDEnet_t *hLLDEnet, uint8_t portNum,
    uint32_t *speed, uint32_t *duplex)
{
#if !ENET_ENABLE_PER_ICSSG
    EnetPhy_GenericInArgs phyInArgs;
 
    EnetMacPort_LinkCfg phyOutArgs;
 
    Enet_IoctlPrms prms;
 
    int32_t status;
 
    if ((hLLDEnet == NULL) || (speed == NULL) || (duplex == NULL)) {
        return LLDENET_E_PARAM;
    }
 
    /* Get port link state (speed & duplexity) from PHY */
 
    phyInArgs.macPort = (Enet_MacPort)(ENET_MACPORT_NORM(portNum));
 
    ENET_IOCTL_SET_INOUT_ARGS(&prms, &phyInArgs, &phyOutArgs);
 
    ENET_IOCTL(hLLDEnet->hEnet, hLLDEnet->coreId,
 
    ENET_RPHY_IOCTL_GET_LINK_MODE, &prms, status);
 
#else
 
    Enet_MacPort phyInArgs;;
    EnetMacPort_LinkCfg phyOutArgs;
    Enet_IoctlPrms prms;
    int32_t status;
 
    if ((hLLDEnet == NULL) || (speed == NULL) || (duplex == NULL)) {
        return LLDENET_E_PARAM;
    }
 
    /* Get port link state (speed & duplexity) from PHY */
    phyInArgs = (Enet_MacPort)(ENET_MACPORT_NORM(portNum));
    ENET_IOCTL_SET_INOUT_ARGS(&prms, &phyInArgs, &phyOutArgs);
    ENET_IOCTL(hLLDEnet->hEnet, hLLDEnet->coreId,
    ENET_PER_IOCTL_GET_PORT_LINK_CFG, &prms, status);
 
#endif
    if (status != ENET_SOK) {
        UB_LOG(UBL_ERROR,"Failed to get link info: %d\n", status);
        return LLDENET_E_IOCTL;
    }
 
    if (phyOutArgs.speed == ENET_SPEED_10MBIT) {
        *speed = 10;
    } else if (phyOutArgs.speed == ENET_SPEED_100MBIT) {
        *speed = 100;
    } else if (phyOutArgs.speed == ENET_SPEED_1GBIT) {
        *speed = 1000;
    } else {
        *speed = 0;
    }
 
    if (phyOutArgs.duplexity == ENET_DUPLEX_FULL) {
        *duplex = 1;
    } else {
        *duplex = 0;
    }
 
    return LLDENET_E_OK;
}

Step-2: Rebuild the TSN stack using the following commands:

# TO CLEAN
gmake -sj -f makefile.am261x tsn_combase-freertos_r5f.ti-arm-clang_clean
gmake -sj -f makefile.am261x tsn_gptp-freertos_r5f.ti-arm-clang_clean
gmake -sj -f makefile.am261x tsn_unibase-freertos_r5f.ti-arm-clang_clean
gmake -sj -f makefile.am261x tsn_uniconf-freertos_r5f.ti-arm-clang_clean
 
# TO BUILD
gmake -sj -f makefile.am261x tsn_combase-freertos_r5f.ti-arm-clang
gmake -sj -f makefile.am261x tsn_gptp-freertos_r5f.ti-arm-clang
gmake -sj -f makefile.am261x tsn_unibase-freertos_r5f.ti-arm-clang
gmake -sj -f makefile.am261x tsn_uniconf-freertos_r5f.ti-arm-clang
 
add PROFILE=debug flag for a debug build

Step-3: If using Both MAC Ports, In the example.syscfg of the gptp_cpsw_app, make sure MAC Port-2 is enabled and pinmux is set as well (you should see all the checkbox ticked for both ports). If using only 1 port, make sure the required port is selected in syscfg and other is disabled. At run-time, make sure that the MAC Port link up is seen with PHY Alive logs.

Step-4: In example.syscfg, change the MAC address assignment to manual if you observe asserts in ti_board_config.c line 408. This indicates that the MAC Address assignment from EEPROM is failing.

Step-5: In example.syscfg, make sure MII mode is selected in Enet(CPSW) pinmux for DP83826 Industrial add-on-board

Step-6: Re-build your application to use the updated stack

Step-7: Test with AM261x.

To know more about testing the gPTP, follow the detailed FAQ on AM261x gPTP Testing: e2e.ti.com/.../faq-am2612-how-to-test-gptp-on-am261x-launchpad

Regards,
Shaunak