FreeRTOS-Plus-TCP/source/portable/NetworkInterface/LPC17xx/NetworkInterface.c

/*
 * FreeRTOS+TCP <DEVELOPMENT BRANCH>
 * Copyright (C) 2022 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
 *
 * SPDX-License-Identifier: MIT
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * http://aws.amazon.com/freertos
 * http://www.FreeRTOS.org
 */

/* Standard includes. */
#include <stdint.h>

/* FreeRTOS includes. */
#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"
#include "semphr.h"

/* Hardware abstraction. */
#include "FreeRTOS_IO.h"

/* FreeRTOS+TCP includes. */
#include "FreeRTOS_UDP_IP.h"
#include "FreeRTOS_Sockets.h"
#include "NetworkBufferManagement.h"

/* Driver includes. */
#include "lpc17xx_emac.h"
#include "lpc17xx_pinsel.h"

/* Demo includes. */
#include "NetworkInterface.h"

#if ipconfigETHERNET_DRIVER_FILTERS_FRAME_TYPES != 1
    #define ipCONSIDER_FRAME_FOR_PROCESSING( pucEthernetBuffer )    eProcessBuffer
#else
    #define ipCONSIDER_FRAME_FOR_PROCESSING( pucEthernetBuffer )    eConsiderFrameForProcessing( ( pucEthernetBuffer ) )
#endif

/* When a packet is ready to be sent, if it cannot be sent immediately then the
 * task performing the transmit will block for niTX_BUFFER_FREE_WAIT
 * milliseconds.  It will do this a maximum of niMAX_TX_ATTEMPTS before giving
 * up. */
#define niTX_BUFFER_FREE_WAIT       ( pdMS_TO_TICKS( 2UL ) )
#define niMAX_TX_ATTEMPTS           ( 5 )

/* The length of the queue used to send interrupt status words from the
 * interrupt handler to the deferred handler task. */
#define niINTERRUPT_QUEUE_LENGTH    ( 10 )

/*-----------------------------------------------------------*/

/*
 * A deferred interrupt handler task that processes
 */
static void prvEMACHandlerTask( void * pvParameters );

/*-----------------------------------------------------------*/

/* The queue used to communicate Ethernet events with the IP task. */
extern QueueHandle_t xNetworkEventQueue;

/* The semaphore used to wake the deferred interrupt handler task when an Rx
 * interrupt is received. */
static SemaphoreHandle_t xEMACRxEventSemaphore = NULL;
/*-----------------------------------------------------------*/

BaseType_t xNetworkInterfaceInitialise( void )
{
    EMAC_CFG_Type Emac_Config;
    PINSEL_CFG_Type xPinConfig;
    BaseType_t xStatus, xReturn;

    /* Enable Ethernet Pins */
    boardCONFIGURE_ENET_PINS( xPinConfig );

    Emac_Config.Mode = EMAC_MODE_AUTO;
    Emac_Config.pbEMAC_Addr = ipLOCAL_MAC_ADDRESS;
    xStatus = EMAC_Init( &Emac_Config );

    LPC_EMAC->IntEnable &= ~( EMAC_INT_TX_DONE );

    if( xStatus != ERROR )
    {
        vSemaphoreCreateBinary( xEMACRxEventSemaphore );
        configASSERT( xEMACRxEventSemaphore != NULL );

        /* The handler task is created at the highest possible priority to
         * ensure the interrupt handler can return directly to it. */
        xTaskCreate( prvEMACHandlerTask, "EMAC", configMINIMAL_STACK_SIZE, NULL, configMAX_PRIORITIES - 1, NULL );

        /* Enable the interrupt and set its priority to the minimum
         * interrupt priority.  */
        NVIC_SetPriority( ENET_IRQn, configMAC_INTERRUPT_PRIORITY );
        NVIC_EnableIRQ( ENET_IRQn );

        xReturn = pdPASS;
    }
    else
    {
        xReturn = pdFAIL;
    }

    configASSERT( xStatus != ERROR );

    return xReturn;
}
/*-----------------------------------------------------------*/

BaseType_t xNetworkInterfaceOutput( NetworkBufferDescriptor_t * const pxNetworkBuffer )
{
    BaseType_t xReturn = pdFAIL;
    int32_t x;
    extern void EMAC_StartTransmitNextBuffer( uint32_t ulLength );
    extern void EMAC_SetNextPacketToSend( uint8_t * pucBuffer );


    /* Attempt to obtain access to a Tx buffer. */
    for( x = 0; x < niMAX_TX_ATTEMPTS; x++ )
    {
        if( EMAC_CheckTransmitIndex() == TRUE )
        {
            /* Will the data fit in the Tx buffer? */
            if( pxNetworkBuffer->xDataLength < EMAC_ETH_MAX_FLEN ) /*_RB_ The size needs to come from FreeRTOSIPConfig.h. */
            {
                /* Assign the buffer to the Tx descriptor that is now known to
                 * be free. */
                EMAC_SetNextPacketToSend( pxNetworkBuffer->pucBuffer );

                /* The EMAC now owns the buffer. */
                pxNetworkBuffer->pucBuffer = NULL;

                /* Initiate the Tx. */
                EMAC_StartTransmitNextBuffer( pxNetworkBuffer->xDataLength );
                iptraceNETWORK_INTERFACE_TRANSMIT();

                /* The Tx has been initiated. */
                xReturn = pdPASS;
            }

            break;
        }
        else
        {
            vTaskDelay( niTX_BUFFER_FREE_WAIT );
        }
    }

    /* Finished with the network buffer. */
    vReleaseNetworkBufferAndDescriptor( pxNetworkBuffer );

    return xReturn;
}
/*-----------------------------------------------------------*/

void ENET_IRQHandler( void )
{
    uint32_t ulInterruptCause;

    while( ( ulInterruptCause = LPC_EMAC->IntStatus ) != 0 )
    {
        /* Clear the interrupt. */
        LPC_EMAC->IntClear = ulInterruptCause;

        /* Clear fatal error conditions.  NOTE:  The driver does not clear all
         * errors, only those actually experienced.  For future reference, range
         * errors are not actually errors so can be ignored. */
        if( ( ulInterruptCause & EMAC_INT_TX_UNDERRUN ) != 0U )
        {
            LPC_EMAC->Command |= EMAC_CR_TX_RES;
        }

        /* Unblock the deferred interrupt handler task if the event was an
         * Rx. */
        if( ( ulInterruptCause & EMAC_INT_RX_DONE ) != 0UL )
        {
            xSemaphoreGiveFromISR( xEMACRxEventSemaphore, NULL );
        }
    }

    /* ulInterruptCause is used for convenience here.  A context switch is
     * wanted, but coding portEND_SWITCHING_ISR( 1 ) would likely result in a
     * compiler warning. */
    portEND_SWITCHING_ISR( ulInterruptCause );
}
/*-----------------------------------------------------------*/

static void prvEMACHandlerTask( void * pvParameters )
{
    size_t xDataLength;
    const uint16_t usCRCLength = 4;
    NetworkBufferDescriptor_t * pxNetworkBuffer;
    IPStackEvent_t xRxEvent = { eNetworkRxEvent, NULL };

/* This is not included in the header file for some reason. */
    extern uint8_t * EMAC_NextPacketToRead( void );

    ( void ) pvParameters;
    configASSERT( xEMACRxEventSemaphore != NULL );

    for( ; ; )
    {
        /* Wait for the EMAC interrupt to indicate that another packet has been
         * received.  The while() loop is only needed if INCLUDE_vTaskSuspend is
         * set to 0 in FreeRTOSConfig.h. */
        while( xSemaphoreTake( xEMACRxEventSemaphore, portMAX_DELAY ) == pdFALSE )
        {
        }

        /* At least one packet has been received. */
        while( EMAC_CheckReceiveIndex() != FALSE )
        {
            /* Obtain the length, minus the CRC.  The CRC is four bytes
             * but the length is already minus 1. */
            xDataLength = ( size_t ) EMAC_GetReceiveDataSize() - ( usCRCLength - 1U );

            if( xDataLength > 0U )
            {
                /* Obtain a network buffer to pass this data into the
                 * stack.  No storage is required as the network buffer
                 * will point directly to the buffer that already holds
                 * the	received data. */
                pxNetworkBuffer = pxGetNetworkBufferWithDescriptor( 0, ( TickType_t ) 0 );

                if( pxNetworkBuffer != NULL )
                {
                    pxNetworkBuffer->pucBuffer = EMAC_NextPacketToRead();
                    pxNetworkBuffer->xDataLength = xDataLength;
                    xRxEvent.pvData = ( void * ) pxNetworkBuffer;

                    /* Data was received and stored.  Send a message to the IP
                     * task to let it know. */
                    if( xSendEventStructToIPTask( &xRxEvent, ( TickType_t ) 0 ) == pdFAIL )
                    {
                        vReleaseNetworkBufferAndDescriptor( pxNetworkBuffer );
                        iptraceETHERNET_RX_EVENT_LOST();
                    }
                }
                else
                {
                    iptraceETHERNET_RX_EVENT_LOST();
                }

                iptraceNETWORK_INTERFACE_RECEIVE();
            }

            /* Release the frame. */
            EMAC_UpdateRxConsumeIndex();
        }
    }
}
/*-----------------------------------------------------------*/