/*
 * 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>
#include <stdio.h>
#include <stdlib.h>

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

/* FreeRTOS+TCP includes. */
#include "FreeRTOS_IP.h"
#include "FreeRTOS_Sockets.h"
#include "FreeRTOS_IP_Private.h"
#include "FreeRTOS_ARP.h"
#include "NetworkBufferManagement.h"
#include "NetworkInterface.h"

/* Xilinx library files. */
#include <xemacps.h>
#include "x_topology.h"
#include "x_emacpsif.h"
#include "x_emacpsif_hw.h"

/* Provided memory configured as uncached. */
#include "uncached_memory.h"

#ifndef niEMAC_HANDLER_TASK_PRIORITY
    /* Define the priority of the task prvEMACHandlerTask(). */
    #define niEMAC_HANDLER_TASK_PRIORITY    configMAX_PRIORITIES - 1
#endif

#define niBMSR_LINK_STATUS                  0x0004uL

#if defined( PHY_LS_HIGH_CHECK_TIME_MS ) || defined( PHY_LS_LOW_CHECK_TIME_MS )
    #error please use the new defines with 'ipconfig' prefix
#endif

#ifndef ipconfigPHY_LS_HIGH_CHECK_TIME_MS

/* Check if the LinkStatus in the PHY is still high after 15 seconds of not
 * receiving packets. */
    #define ipconfigPHY_LS_HIGH_CHECK_TIME_MS    15000U
#endif

#ifndef ipconfigPHY_LS_LOW_CHECK_TIME_MS
    /* Check if the LinkStatus in the PHY is still low every second. */
    #define ipconfigPHY_LS_LOW_CHECK_TIME_MS    1000U
#endif


#if ( ipconfigNETWORK_MTU > 1526 )
    #if ( ipconfigPORT_SUPPRESS_WARNING == 0 )
        #warning the use of Jumbo Frames has not been tested sufficiently yet.
    #endif
    #define USE_JUMBO_FRAMES    1
#endif

/* The size of each buffer when BufferAllocation_1 is used:
 * http://www.freertos.org/FreeRTOS-Plus/FreeRTOS_Plus_TCP/Embedded_Ethernet_Buffer_Management.html */
#if ( USE_JUMBO_FRAMES == 1 )
    #define niBUFFER_1_PACKET_SIZE    10240
#else
    #define niBUFFER_1_PACKET_SIZE    1536
#endif

/* Naming and numbering of PHY registers. */
#define PHY_REG_01_BMSR    0x01         /* Basic mode status register */

#ifndef iptraceEMAC_TASK_STARTING
    #define iptraceEMAC_TASK_STARTING()    do {} while( 0 )
#endif

/* Default the size of the stack used by the EMAC deferred handler task to twice
 * the size of the stack used by the idle task - but allow this to be overridden in
 * FreeRTOSConfig.h as configMINIMAL_STACK_SIZE is a user definable constant. */
#ifndef configEMAC_TASK_STACK_SIZE
    #define configEMAC_TASK_STACK_SIZE    ( 8 * configMINIMAL_STACK_SIZE )
#endif

#if ( ipconfigZERO_COPY_RX_DRIVER == 0 || ipconfigZERO_COPY_TX_DRIVER == 0 )
    #error Please define both 'ipconfigZERO_COPY_RX_DRIVER' and 'ipconfigZERO_COPY_TX_DRIVER' as 1
#endif

#if ( ipconfigDRIVER_INCLUDED_RX_IP_CHECKSUM == 0 || ipconfigDRIVER_INCLUDED_TX_IP_CHECKSUM == 0 )
    #if ( ipconfigPORT_SUPPRESS_WARNING == 0 )
        #warning Please define both 'ipconfigDRIVER_INCLUDED_RX_IP_CHECKSUM' and 'ipconfigDRIVER_INCLUDED_TX_IP_CHECKSUM' as 1
    #endif
#endif

#ifndef nicUSE_UNCACHED_MEMORY

/*
 * Don't use cached memory for network buffer, which is more efficient than
 * using cached memory.
 */
    #define nicUSE_UNCACHED_MEMORY    0
#endif

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

/*
 * Look for the link to be up every few milliseconds until
 * xMaxTimeTicks has passed or a link is found.
 */
static BaseType_t prvGMACWaitLS( TickType_t xMaxTimeTicks );

/*
 * A deferred interrupt handler for all MAC/DMA interrupt sources.
 */
static void prvEMACHandlerTask( void * pvParameters );

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

/* EMAC data/descriptions. */
static xemacpsif_s xEMACpsif;
struct xtopology_t xXTopology =
{
    .emac_baseaddr    = XPAR_XEMACPS_0_BASEADDR,
    .emac_type        = xemac_type_emacps,
    .intc_baseaddr    = 0x0,
    .intc_emac_intr   = 0x0,
    .scugic_baseaddr  = XPAR_SCUGIC_0_CPU_BASEADDR,
    .scugic_emac_intr = XPAR_XEMACPS_3_INTR,
};

XEmacPs_Config mac_config =
{
    .DeviceId        = XPAR_PSU_ETHERNET_3_DEVICE_ID, /**< Unique ID  of device */
    .BaseAddress     = XPAR_PSU_ETHERNET_3_BASEADDR,  /**< Physical base address of IPIF registers */
    .IsCacheCoherent = XPAR_PSU_ETHERNET_3_IS_CACHE_COHERENT
};

/* A copy of PHY register 1: 'PHY_REG_01_BMSR' */
static uint32_t ulPHYLinkStatus = 0uL;

#if ( ipconfigUSE_LLMNR == 1 )
    static const uint8_t xLLMNR_MACAddress[] = { 0x01, 0x00, 0x5E, 0x00, 0x00, 0xFC };
#endif

/* Holds the handle of the task used as a deferred interrupt processor.  The
 * handle is used so direct notifications can be sent to the task for all EMAC/DMA
 * related interrupts. */
TaskHandle_t xEMACTaskHandle = NULL;

/* The PHY index where a PHY was found. */
static u32 ulPHYIndex;

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

/* The function xNetworkInterfaceInitialise() will be called as
 * long as it returns the value pdFAIL.
 * It will go through several stages as described in 'eEMACState'.
 */
typedef enum xEMAC_STATE
{
    xEMAC_Init,
    xEMAC_SetupPHY,
    xEMAC_WaitPHY,
    xEMAC_Ready,
    xEMAC_Fatal,
} EMACState_t;

static EMACState_t eEMACState = xEMAC_Init;

BaseType_t xNetworkInterfaceInitialise( void )
{
    uint32_t ulLinkSpeed, ulDMAReg;
    BaseType_t xStatus, xReturn = pdFAIL;
    XEmacPs * pxEMAC_PS = &( xEMACpsif.emacps );
    const TickType_t xWaitLinkDelay = pdMS_TO_TICKS( 1000U );

    switch( eEMACState )
    {
        case xEMAC_Init:

            ulPHYLinkStatus = 0U;
            memset( &xEMACpsif, '\0', sizeof( xEMACpsif ) );

            xStatus = XEmacPs_CfgInitialize( pxEMAC_PS, &mac_config, mac_config.BaseAddress );

            if( xStatus != XST_SUCCESS )
            {
                FreeRTOS_printf( ( "xEMACInit: EmacPs Configuration Failed....\n" ) );
                eEMACState = xEMAC_Fatal;
                break;
            }

/* _HT_ : the use of jumbo frames has not been tested sufficiently yet. */

            if( pxEMAC_PS->Version > 2 )
            {
                #if ( USE_JUMBO_FRAMES == 1 )
                    /* Enable jumbo frames for zynqmp */
                    XEmacPs_SetOptions( pxEMAC_PS, XEMACPS_JUMBO_ENABLE_OPTION );
                #endif
            }

            /* Initialize the mac and set the MAC address. */
            XEmacPs_SetMacAddress( pxEMAC_PS, ( void * ) ipLOCAL_MAC_ADDRESS, 1 );

            #if ( ipconfigUSE_LLMNR == 1 )
                {
                    /* Also add LLMNR multicast MAC address. */
                    XEmacPs_SetMacAddress( pxEMAC_PS, ( void * ) xLLMNR_MACAddress, 2 );
                }
            #endif /* ipconfigUSE_LLMNR == 1 */

            XEmacPs_SetMdioDivisor( pxEMAC_PS, MDC_DIV_224 );
            ulPHYIndex = ulDetecPHY( pxEMAC_PS );

            if( ulPHYIndex == ~0U )
            {
                FreeRTOS_printf( ( "xEMACInit: No valid PHY was found\n" ) );
                eEMACState = xEMAC_Fatal;
                break;
            }

            eEMACState = xEMAC_SetupPHY;

        /* Fall through. */

        case xEMAC_SetupPHY:
            ulLinkSpeed = Phy_Setup_US( pxEMAC_PS, ulPHYIndex );

            if( ulLinkSpeed == XST_FAILURE )
            {
                /* The speed could not be determined yet.
                 * This is not a fatal error.
                 * xNetworkInterfaceInitialise() will be called again
                 * by the IP-task.
                 */
                break;
            }

            XEmacPs_SetOperatingSpeed( pxEMAC_PS, ulLinkSpeed );

            /* Setting the operating speed of the MAC needs a delay. */
            vTaskDelay( pdMS_TO_TICKS( 25UL ) );

            ulDMAReg = XEmacPs_ReadReg( pxEMAC_PS->Config.BaseAddress, XEMACPS_DMACR_OFFSET );
            /* Enable 16-bytes AHB bursts */
            ulDMAReg = ulDMAReg | XEMACPS_DMACR_INCR16_AHB_BURST;

            /* DISC_WHEN_NO_AHB: when set, the GEM DMA will automatically discard receive
             * packets from the receiver packet buffer memory when no AHB resource is available. */
            XEmacPs_WriteReg( pxEMAC_PS->Config.BaseAddress, XEMACPS_DMACR_OFFSET,
                              ulDMAReg /*| XEMACPS_DMACR_DISC_WHEN_NO_AHB_MASK*/ );

            setup_isr( &xEMACpsif );
            init_dma( &xEMACpsif );
            start_emacps( &xEMACpsif );
            eEMACState = xEMAC_WaitPHY;

        /* Fall through. */

        case xEMAC_WaitPHY:
            prvGMACWaitLS( xWaitLinkDelay );

            if( xGetPhyLinkStatus() == pdFALSE )
            {
                /* The Link Status is not yet high, Stay in 'xEMAC_WaitPHY'. */
                break;
            }

            if( xEMACTaskHandle == NULL )
            {
                /* The deferred interrupt handler task is created at the highest
                 * possible priority to ensure the interrupt handler can return directly
                 * to it.  The task's handle is stored in xEMACTaskHandle so interrupts can
                 * notify the task when there is something to process. */
                xTaskCreate( prvEMACHandlerTask, "EMAC", configEMAC_TASK_STACK_SIZE, NULL, niEMAC_HANDLER_TASK_PRIORITY, &xEMACTaskHandle );

                if( xEMACTaskHandle == NULL )
                {
                    eEMACState = xEMAC_Fatal;
                    break;
                }
            }

            eEMACState = xEMAC_Ready;

        /* Fall through. */

        case xEMAC_Ready:
            /* The network driver is operational. */
            xReturn = pdPASS;
            break;

        case xEMAC_Fatal:

            /* A fatal error has occurred, and the driver
             * can not start. */
            break;
    } /* switch( eEMACState ) */

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

BaseType_t xNetworkInterfaceOutput( NetworkBufferDescriptor_t * const pxBuffer,
                                    BaseType_t bReleaseAfterSend )
{
    #if ( ipconfigDRIVER_INCLUDED_TX_IP_CHECKSUM != 0 )
        {
            ProtocolPacket_t * pxPacket;

            /* If the peripheral must calculate the checksum, it wants
             * the protocol checksum to have a value of zero. */
            pxPacket = ( ProtocolPacket_t * ) ( pxBuffer->pucEthernetBuffer );

            if( ( pxPacket->xICMPPacket.xEthernetHeader.usFrameType == ipIPv4_FRAME_TYPE ) &&
                ( pxPacket->xICMPPacket.xIPHeader.ucProtocol != ipPROTOCOL_UDP ) &&
                ( pxPacket->xICMPPacket.xIPHeader.ucProtocol != ipPROTOCOL_TCP ) )
            {
                /* The EMAC will calculate the checksum of the IP-header.
                 * It can only calculate protocol checksums of UDP and TCP,
                 * so for ICMP and other protocols it must be done manually. */
                usGenerateProtocolChecksum( ( uint8_t * ) &( pxPacket->xUDPPacket ), pxBuffer->xDataLength, pdTRUE );
            }
        }
    #endif /* ipconfigDRIVER_INCLUDED_TX_IP_CHECKSUM */

    if( ( ulPHYLinkStatus & niBMSR_LINK_STATUS ) != 0UL )
    {
        iptraceNETWORK_INTERFACE_TRANSMIT();
        emacps_send_message( &xEMACpsif, pxBuffer, bReleaseAfterSend );
    }
    else if( bReleaseAfterSend != pdFALSE )
    {
        /* No link. */
        vReleaseNetworkBufferAndDescriptor( pxBuffer );
    }

    return pdTRUE;
}
/*-----------------------------------------------------------*/

static inline unsigned long ulReadMDIO( unsigned ulRegister )
{
    uint16_t usValue;

    XEmacPs_PhyRead( &( xEMACpsif.emacps ), ulPHYIndex, ulRegister, &usValue );
    return usValue;
}
/*-----------------------------------------------------------*/

static BaseType_t prvGMACWaitLS( TickType_t xMaxTimeTicks )
{
    TickType_t xStartTime, xEndTime;
    const TickType_t xShortDelay = pdMS_TO_TICKS( 20UL );
    BaseType_t xReturn;

    xStartTime = xTaskGetTickCount();

    for( ; ; )
    {
        xEndTime = xTaskGetTickCount();

        if( xEndTime - xStartTime > xMaxTimeTicks )
        {
            xReturn = pdFALSE;
            break;
        }

        ulPHYLinkStatus = ulReadMDIO( PHY_REG_01_BMSR );

        if( ( ulPHYLinkStatus & niBMSR_LINK_STATUS ) != 0uL )
        {
            xReturn = pdTRUE;
            break;
        }

        vTaskDelay( xShortDelay );
    }

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

#if ( nicUSE_UNCACHED_MEMORY == 0 )
    void vNetworkInterfaceAllocateRAMToBuffers( NetworkBufferDescriptor_t pxNetworkBuffers[ ipconfigNUM_NETWORK_BUFFER_DESCRIPTORS ] )
    {
        static uint8_t ucNetworkPackets[ ipconfigNUM_NETWORK_BUFFER_DESCRIPTORS * niBUFFER_1_PACKET_SIZE ] __attribute__( ( aligned( 32 ) ) );
        uint8_t * ucRAMBuffer = ucNetworkPackets;
        uint32_t ul;

        for( ul = 0; ul < ipconfigNUM_NETWORK_BUFFER_DESCRIPTORS; ul++ )
        {
            pxNetworkBuffers[ ul ].pucEthernetBuffer = ucRAMBuffer + ipBUFFER_PADDING;
            *( ( uintptr_t * ) ucRAMBuffer ) = ( uintptr_t ) &( pxNetworkBuffers[ ul ] );
            ucRAMBuffer += niBUFFER_1_PACKET_SIZE;
        }
    }
#else /* if ( nicUSE_UNCACHED_MEMORY == 0 ) */
    void vNetworkInterfaceAllocateRAMToBuffers( NetworkBufferDescriptor_t pxNetworkBuffers[ ipconfigNUM_NETWORK_BUFFER_DESCRIPTORS ] )
    {
        static uint8_t * pucNetworkPackets = NULL;

        if( pucNetworkPackets == NULL )
        {
            pucNetworkPackets = pucGetUncachedMemory( ipconfigNUM_NETWORK_BUFFER_DESCRIPTORS * niBUFFER_1_PACKET_SIZE );

            if( pucNetworkPackets != NULL )
            {
                uint8_t * ucRAMBuffer = pucNetworkPackets;
                uint32_t ul;

                for( ul = 0; ul < ipconfigNUM_NETWORK_BUFFER_DESCRIPTORS; ul++ )
                {
                    pxNetworkBuffers[ ul ].pucEthernetBuffer = ucRAMBuffer + ipBUFFER_PADDING;
                    *( ( unsigned * ) ucRAMBuffer ) = ( unsigned ) ( &( pxNetworkBuffers[ ul ] ) );
                    ucRAMBuffer += niBUFFER_1_PACKET_SIZE;
                }
            }
        }
    }
#endif /* ( nicUSE_UNCACHED_MEMORY == 0 ) */
/*-----------------------------------------------------------*/

BaseType_t xGetPhyLinkStatus( void )
{
    BaseType_t xReturn;

    if( ( ulPHYLinkStatus & niBMSR_LINK_STATUS ) == 0uL )
    {
        xReturn = pdFALSE;
    }
    else
    {
        xReturn = pdTRUE;
    }

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

static void prvEMACHandlerTask( void * pvParameters )
{
    TimeOut_t xPhyTime;
    TickType_t xPhyRemTime;
    BaseType_t xResult = 0;
    uint32_t xStatus;
    const TickType_t ulMaxBlockTime = pdMS_TO_TICKS( 100UL );

    /* Remove compiler warnings about unused parameters. */
    ( void ) pvParameters;

    /* A possibility to set some additional task properties like calling
     * portTASK_USES_FLOATING_POINT() */
    iptraceEMAC_TASK_STARTING();

    vTaskSetTimeOutState( &xPhyTime );
    xPhyRemTime = pdMS_TO_TICKS( ipconfigPHY_LS_LOW_CHECK_TIME_MS );

    for( ; ; )
    {
        #if ( ipconfigHAS_PRINTF != 0 )
            {
                /* Call a function that monitors resources: the amount of free network
                 * buffers and the amount of free space on the heap.  See FreeRTOS_IP.c
                 * for more detailed comments. */
                vPrintResourceStats();
            }
        #endif /* ( ipconfigHAS_PRINTF != 0 ) */

        if( ( xEMACpsif.isr_events & EMAC_IF_ALL_EVENT ) == 0 )
        {
            /* No events to process now, wait for the next. */
            ulTaskNotifyTake( pdFALSE, ulMaxBlockTime );
        }

        if( ( xEMACpsif.isr_events & EMAC_IF_RX_EVENT ) != 0 )
        {
            xEMACpsif.isr_events &= ~EMAC_IF_RX_EVENT;
            xResult = emacps_check_rx( &xEMACpsif );
        }

        if( ( xEMACpsif.isr_events & EMAC_IF_TX_EVENT ) != 0 )
        {
            xEMACpsif.isr_events &= ~EMAC_IF_TX_EVENT;
            emacps_check_tx( &xEMACpsif );
        }

        if( ( xEMACpsif.isr_events & EMAC_IF_ERR_EVENT ) != 0 )
        {
            xEMACpsif.isr_events &= ~EMAC_IF_ERR_EVENT;
            emacps_check_errors( &xEMACpsif );
        }

        if( xResult > 0 )
        {
            /* A packet was received. No need to check for the PHY status now,
             * but set a timer to check it later on. */
            vTaskSetTimeOutState( &xPhyTime );
            xPhyRemTime = pdMS_TO_TICKS( ipconfigPHY_LS_HIGH_CHECK_TIME_MS );
            xResult = 0;

            if( ( ulPHYLinkStatus & niBMSR_LINK_STATUS ) == 0uL )
            {
                /* Indicate that the Link Status is high, so that
                 * xNetworkInterfaceOutput() can send packets. */
                ulPHYLinkStatus |= niBMSR_LINK_STATUS;
                FreeRTOS_printf( ( "prvEMACHandlerTask: PHY LS assume 1\n" ) );
            }
        }
        else if( xTaskCheckForTimeOut( &xPhyTime, &xPhyRemTime ) != pdFALSE )
        {
            xStatus = ulReadMDIO( PHY_REG_01_BMSR );

            if( ( ulPHYLinkStatus & niBMSR_LINK_STATUS ) != ( xStatus & niBMSR_LINK_STATUS ) )
            {
                ulPHYLinkStatus = xStatus;
                FreeRTOS_printf( ( "prvEMACHandlerTask: PHY LS now %d\n", ( ulPHYLinkStatus & niBMSR_LINK_STATUS ) != 0uL ) );
            }

            vTaskSetTimeOutState( &xPhyTime );

            if( ( ulPHYLinkStatus & niBMSR_LINK_STATUS ) != 0uL )
            {
                xPhyRemTime = pdMS_TO_TICKS( ipconfigPHY_LS_HIGH_CHECK_TIME_MS );
            }
            else
            {
                xPhyRemTime = pdMS_TO_TICKS( ipconfigPHY_LS_LOW_CHECK_TIME_MS );
            }
        }
    }
}
/*-----------------------------------------------------------*/