ICSS-EMAC

Table of Contents

• Introduction
• Features Supported
• SysConfig Features
• Features not supported
• Terms and Abbreviations
• ICSS-EMAC Design
• Usage
  • Initializing the Handle
  • Sending a Packet
  • Receiving a Packet
  • IOCTL
• Dependencies
• Debug Guide
• API

Introduction

The ICSS-EMAC (Industrial Communications Subsystem Ethernet Media Access Controller) driver provide APIs to transmit and receive packets with a firmware based Ethernet switch that has been implemented on PRUICSS cores.

ICSS-EMAC runs on the host processor, provides a well defined set of APIs to configure the firmware, send packets to the firmware and receive packet from the firmware. Industrial Protocol specific firmware (running on PRUICSS cores) implements a 2 port ethernet switch supporting 802.1d at 100 Mbps.

Note

ICSS-EMAC will be supported for use in Profinet Device and EtherNet/IP Adapter examples only.

Features Supported

• Packet Receieve: Copying packet received from firmware and providing it to TCP/IP stack or upper layer protocols
• Packet Transmit: Providing packet from a TCP/IP stack or upper layer protocols to firmware
• Storm Prevention
• Host Statistics
• Learning/Forwarding Data Base
• Multicast/VLAN Filtering
• Interrupt handling for Rx, Tx and Link
• Task Creation for Rx, Tx and Link

SysConfig Features

Note

It is strongly recommend to use SysConfig where it is available instead of using direct SW API calls. This will help simplify the SW application and also catch common mistakes early in the development cycle.

• Selecting the PRU-ICSS instance
• Selecting port number
• Configuring PHY address for the ports
• Select queue threshold for separating real-time(RT) and non real-time(NRT) traffic
• Specify the size of buffer space
• Provide the task priorities for Rx, Tx and Link tasks

Features not supported

• Time-triggered send (TTS)
• Firmware Learning mode
• Timer based Interrupt Pacing support

Terms and Abbreviations

Abbreviation	Expansion
PRU-ICSS	Programmable Real-Time Unit Industrial Communication Subsystem
EMAC	Ethernet MAC
Rx/Tx	Packet Receive/Packet Transmit
INTC	Interrupt Controller
DLR	Device Level Ring (A redundancy protocol for EtherNet/IP)
Host/CPU/Cortex	Used interchangeably and refers to the Application Processor

ICSS-EMAC Design

ICSS-EMAC Design explains the driver design in detail.

Usage

Include the below file to access the APIs

#include <networking/icss_emac/icss_emac.h>

Initializing the Handle

• PRUICSS handle needs to be initialized before ICSS_EMAC_open and passed using ICSS_EMAC_Params.
• PRUICSS_IntcInitData should be passed based on the firmware. See PRUICSS Interrupt Controller page for more details.
• ICSS-EMAC needs information about the memory map of firmware which will be used. User needs to provide the same information in the form of ICSS_EMAC_FwStaticMmap and ICSS_EMAC_FwDynamicMmap while filling the ICSS_EMAC_Params structure. There are some other offsets related to VLAN filtering and multicast filtering, for which the structures ICSS_EMAC_FwVlanFilterParams and ICSS_EMAC_FwMulticastFilterParams should be passed if IOCTL for VLAN and multicast filtering are going to be called. For Profinet and EtherNet/IP firmware, these structures are defined in ${SDK_INSTALL_PATH}/source/industrial_protocols/profinet_device/icss_fwhal/firmware/icss_emac_mmap.h and ${SDK_INSTALL_PATH}/source/industrial_protocols/ethernetip_adapter/icss_fwhal/firmware/icss_emac_mmap.h respectively.
• Various callback functions can be set using ICSS_EMAC_CallBackObject structure.
• Please see ICSS_EMAC_Params for information on which members are mandatory. If mandatory options are not passed, DebugP_assert will fail in ICSS_EMAC_open.

 
    PRUICSS_Handle      pruicssHandle;
    ICSS_EMAC_Params    icssEmacParams;
    ICSS_EMAC_Handle    icssEmacHandle;
 
    pruicssHandle = PRUICSS_open(CONFIG_PRU_ICSSG1);
    DebugP_assert(pruicssHandle != NULL);
 
    ICSS_EMAC_Params_init(&icssEmacParams);
 
    /* Fill the icssEmacParams as needed */
 
    /*Use CONFIG_ICSS_EMAC1 (as configured in SysConfig) macro as parameter to ICSS_EMAC_open */
    icssEmacHandle = ICSS_EMAC_open(CONFIG_ICSS_EMAC1, &icssEmacParams);
    DebugP_assert(icssEmacHandle != NULL);
 

Sending a Packet

    ICSS_EMAC_TxArgument    txArgs;
    int32_t                 status;
 
    txArgs.icssEmacHandle = icssEmacHandle;
    txArgs.srcAddress = &testPacketArray[0];
    txArgs.portNumber = ICSS_EMAC_PORT_1;
    txArgs.queuePriority = ICSS_EMAC_QUEUE4;
    txArgs.lengthOfPacket = sizeof(testPacketArray);
 
    status = ICSS_EMAC_txPacket(&txArgs, NULL);
    DebugP_assert(status == SystemP_SUCCESS);

Receiving a Packet

ICSS_EMAC_rxPktGet is the API used for receving packets. Refer Rx Data Path for more details. Following is an example usage:

 
/*
Assume that following callback was registered while passing ICSS_EMAC_Params for ICSS_EMAC_open call
icssEmacParams.callBackObject.rxNRTCallBack.callBack = (ICSS_EMAC_CallBack)nrtCallbackRx;
*/
void nrtCallbackRx(void *icssEmacHandleVoidPtr, void *queueNum, void *userArg)
{
    ICSS_EMAC_Handle        icssEmacHandle = (ICSS_EMAC_Handle)icssEmacHandleVoidPtr;
    ICSS_EMAC_RxArgument    rxArgs;
    int32_t                 packetLength;
    uint8_t                 testPacketArray[ICSS_EMAC_MAXMTU];
 
    rxArgs.icssEmacHandle = icssEmacHandle;
    rxArgs.queueNumber = ((uint32_t)(queueNum));
    rxArgs.more = 0; /* Returns more which is set to 1 if there are more frames in the queue */
    rxArgs.port = 0; /* Returns port number on which frame was received */
    rxArgs.destAddress =  (uint32_t)(&testPacketArray[0]);
 
    memset(testPacketArray, 0, ICSS_EMAC_MAXMTU);
 
    packetLength = ICSS_EMAC_rxPktGet(&rxArgs, NULL);
}

IOCTL

IOCTL implementation is identical to the Unix/Linux based IOCTL calls. They provide the application a convenient method to access driver space parameters or modify them. Users are expected to familiarize themselves with the full list of IOCTL calls so that they can utilize all the features provided.

The API for IOCTL is ICSS_EMAC_ioctl. An IOCTL call uses two parameters to find out which driver function to call internally.

1. ioctlCommand : Used to locate the module which should be called. Allowed values are ICSS_EMAC_IOCTL_COMMANDS.
2. ioctlParams : Used to give module specific instructions. ioctlParams consists of
   • command : Indicates which specific command to execute. Allowed values for ioctlParams.command are ICSS_EMAC_IOCTL_STORM_PREV_CTRL_COMMANDS, ICSS_EMAC_IOCTL_LEARNING_CTRL_COMMANDS, ICSS_EMAC_IOCTL_STATISTICS_COMMANDS, ICSS_EMAC_IOCTL_MULTICAST_FILTER_CTRL_COMMANDS, ICSS_EMAC_IOCTL_VLAN_FILTER_CTRL_COMMANDS.
   • ioctlVal : Sometimes the command may require specific input, this is used to provide that.

For example, to disable receive functionality on a port, following code is used.

    ICSS_EMAC_IoctlCmd  ioctlParams;
    uint8_t             ioctlvalue = 0;
 
    ioctlvalue = ICSS_EMAC_IOCTL_PORT_CTRL_DISABLE;
    ioctlParams.ioctlVal = &ioctlvalue;
    ICSS_EMAC_ioctl(icssEmacHandle, ICSS_EMAC_IOCTL_PORT_CTRL, (uint8_t)ICSS_EMAC_PORT_1, (void*)&ioctlParams);

Dependencies

ICSS-EMAC is dependent on the Application/Transport layer for proper functioning. Following dependencies should be handled by the application layer (example) :

• MDIO Configuration : MDIO Initialization is not done by ICSS-EMAC.
• PHY Initialization/Configuration
• Learning Module Increment Counter Implementation : If learning is enabled, application needs to call IOCTL with ICSS_EMAC_LEARN_CTRL_INC_COUNTER periodically.

Debug Guide

ICSS-EMAC Debug Guide covers the most obvious use cases and debug scenarios encountered while using ICSS-EMAC.

API

APIs for ICSS-EMAC