/**
 * @file
 * Ethernet Interface Skeleton
 *
 */

/*
 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 * This file is part of the lwIP TCP/IP stack.
 *
 * Author: Adam Dunkels <adam@sics.se>
 *
 */

/*
 * This file is a skeleton for developing Ethernet network interface
 * drivers for lwIP. Add code to the low_level functions and do a
 * search-and-replace for the word "ethernetif" to replace it with
 * something that better describes your network interface.
 */

#include "lwip/opt.h"

#include "lwip/sys.h"
#include "lwip/def.h"
#include "lwip/mem.h"
#include "lwip/pbuf.h"
#include "lwip/stats.h"
#include "lwip/snmp.h"
#include "lwip/ethip6.h"
#include "lwip/etharp.h"
#include "netif/ppp/pppoe.h"

#include "ethernetif.h"

#include "FreeRTOS.h"
#include "semphr.h"

/* Define those to better describe your network interface. */
#define IFNAME0 'n'
#define IFNAME1 'a'


extern __IO ETH_DMADescType* DMATxDescToSet;
extern __IO ETH_DMADescType* DMARxDescToGet;

extern __IO ETH_RxFrameInfoType* DMARxFrameInfos;

xSemaphoreHandle SemHandle = NULL;
xSemaphoreHandle xTxMutex  = NULL;


/**
 * Helper struct to hold private data used to operate your ethernet interface.
 * Keeping the ethernet address of the MAC in this struct is not necessary
 * as it is already kept in the struct netif.
 * But this is only an example, anyway...
 */
struct ethernetif {
    struct eth_addr *ethaddr;
    /* Add whatever per-interface state that is needed here. */
};


static void low_level_init(struct netif *netif);
static err_t low_level_output(struct netif *netif, struct pbuf *p);
static struct pbuf* low_level_input(struct netif *netif);



/**
 * In this function, the hardware should be initialized.
 * Called from ethernetif_init().
 *
 * @param netif the already initialized lwip network interface structure
 *        for this ethernetif
 */
static void low_level_init(struct netif *netif)
{
    ErrorStatus EthInitStatus;

    /* Initialize ETH */
    EthInitStatus = ETH_BSP_Init();
    if (EthInitStatus == ERROR)
    {
        printf("#ERROR: ETH BSP Initialize error\n");
    }
    else
    {
        /* Set netif link flag */
        netif_set_link_up(netif);
    }

    /* Set MAC hardware address length */
    netif->hwaddr_len = ETHARP_HWADDR_LEN;

    /* Set MAC hardware address to netif */
    netif->hwaddr[0] = MAC_ADDR0;
    netif->hwaddr[1] = MAC_ADDR1;
    netif->hwaddr[2] = MAC_ADDR2;
    netif->hwaddr[3] = MAC_ADDR3;
    netif->hwaddr[4] = MAC_ADDR4;
    netif->hwaddr[5] = MAC_ADDR5;

    /* Maximum transfer unit */
    netif->mtu = ETH_NETIF_MTU;

    /* Device capabilities */
    /* Don't set NETIF_FLAG_ETHARP if this device is not an ethernet one */
    netif->flags |= (NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP);

#if LWIP_IPV6 && LWIP_IPV6_MLD
    /*
    * For hardware/netifs that implement MAC filtering.
    * All-nodes link-local is handled by default, so we must let the hardware know
    * to allow multicast packets in.
    * Should set mld_mac_filter previously. */
    if (netif->mld_mac_filter != NULL) {
        ip6_addr_t ip6_allnodes_ll;
        ip6_addr_set_allnodes_linklocal(&ip6_allnodes_ll);
        netif->mld_mac_filter(netif, &ip6_allnodes_ll, NETIF_ADD_MAC_FILTER);
    }
#endif /* LWIP_IPV6 && LWIP_IPV6_MLD */
    
    /* Creates a new counting semaphore instance, and returns a handle */
    SemHandle = xSemaphoreCreateCounting(64,0);

    /* Create a mutex for sending */
    xTxMutex = xSemaphoreCreateMutex();
    /* Ensure successful creation */
    configASSERT(xTxMutex);
    
    /* Creates a task that handles ETH receive data */
    sys_thread_new("eth_input",                  /* Task name */
                   ethernetif_input,             /* Task entry function */
                   netif,                        /* Task entry function parameter */
                   ETH_NETIF_IN_TASK_STACK_SIZE, /* Task stack size */
                   ETH_NETIF_IN_TASK_PRIORITY);  /* Task priority */

    /* Turn on ETH */
    ETH_Start();
}

/**
 * This function should do the actual transmission of the packet. The packet is
 * contained in the pbuf that is passed to the function. This pbuf
 * might be chained.
 *
 * @param netif the lwip network interface structure for this ethernetif
 * @param p the MAC packet to send (e.g. IP packet including MAC addresses and type)
 * @return ERR_OK if the packet could be sent
 *         an err_t value if the packet couldn't be sent
 *
 * @note Returning ERR_MEM here if a DMA queue of your MAC is full can lead to
 *       strange results. You might consider waiting for space in the DMA queue
 *       to become available since the stack doesn't retry to send a packet
 *       dropped because of memory failure (except for the TCP timers).
 */
static err_t low_level_output(struct netif *netif, struct pbuf *p)
{
    err_t errRet;
    uint32_t frameLength        = 0;
    uint32_t bufferOffset       = 0;
    uint32_t bytesCurrentBuffer = 0;
    uint32_t payloadOffset      = 0;
    struct   pbuf *q = NULL;
    __IO ETH_DMADescType *DMATxDesc = DMATxDescToSet;
    uint8_t *pBuffer = (uint8_t *)(DMATxDescToSet->Buf1Addr);

    if (xSemaphoreTake(xTxMutex, portMAX_DELAY) != pdTRUE)
    {
        return ERR_TIMEOUT;
    }

    /* Check if the descriptor is owned by the ETHERNET DMA (when set) or CPU (when reset) */
    /* Is this buffer available? If not, goto error */
    if ((DMATxDesc->Status & ETH_DMA_TX_DESC_OWN) != (uint32_t)RESET)
    {
        errRet = ERR_USE;
        goto error;
    }

    /* copy frame from pbufs to driver buffers */
    for (q = p; q != NULL; q = q->next)
    {
        /* Get bytes in current lwIP buffer */
        bytesCurrentBuffer = q->len;
        payloadOffset = 0;

        /* Check if the length of data to copy is bigger than Tx buffer size*/
        while ((bytesCurrentBuffer + bufferOffset) > ETH_TX_BUF_SIZE)
        {
            /* Copy data to Tx buffer*/
            memcpy((uint8_t*)((uint8_t*)pBuffer + bufferOffset), (uint8_t*)((uint8_t*)q->payload + payloadOffset), (ETH_TX_BUF_SIZE - bufferOffset));

            /* Point to next descriptor */
            DMATxDesc = (ETH_DMADescType *)(DMATxDesc->Buf2OrNextDescAddr);

            /* Check if the buffer is available */
            if ((DMATxDesc->Status & ETH_DMA_TX_DESC_OWN) != (uint32_t)RESET)
            {
                errRet = ERR_USE;
                goto error;
            }

            pBuffer = (uint8_t *)(DMATxDesc->Buf1Addr);

            bytesCurrentBuffer = bytesCurrentBuffer - (ETH_TX_BUF_SIZE - bufferOffset);
            payloadOffset = payloadOffset + (ETH_TX_BUF_SIZE - bufferOffset);
            frameLength = frameLength + (ETH_TX_BUF_SIZE - bufferOffset);
            bufferOffset = 0;
        }

        /* Copy the remaining bytes */
        memcpy((uint8_t*)((uint8_t*)pBuffer + bufferOffset), (uint8_t*)((uint8_t*)q->payload + payloadOffset), bytesCurrentBuffer);
        bufferOffset = bufferOffset + bytesCurrentBuffer;
        frameLength = frameLength + bytesCurrentBuffer;
    }

    /* Prepare transmit descriptors to give to DMA */
    ETH_PrepareTransmitDescriptors(frameLength);
    errRet = ERR_OK;

error:

    /* When Transmit Underflow flag is set, clear it and issue a Transmit Poll Demand to resume transmission */
    if ((ETH->DMASTS & ETH_DMASTS_TU) != (uint32_t)RESET)
    {
        /* Clear TBUS ETHERNET DMA flag */
        ETH->DMASTS = ETH_DMASTS_TU;
        /* Resume DMA transmission*/
        ETH->DMATXPD = 0;
    }
    
    /* Task owner released */
    xSemaphoreGive(xTxMutex);
    return errRet;
}

/**
 * Should allocate a pbuf and transfer the bytes of the incoming
 * packet from the interface into the pbuf.
 *
 * @param netif the lwip network interface structure for this ethernetif
 * @return a pbuf filled with the received packet (including MAC header)
 *         NULL on memory error
 */
static struct pbuf* low_level_input(struct netif *netif)
{
    __IO uint32_t Index = 0;
    struct pbuf *p   = NULL;
    struct pbuf *q   = NULL;
    uint8_t *pBuffer = NULL;

    ETH_FrameType rxFrame;
    uint32_t frameLen           = 0;
    uint32_t bufferOffset       = 0;
    uint32_t bytesCurrentBuffer = 0;
    uint32_t payloadOffset      = 0;
    __IO ETH_DMADescType *DMARxDesc;

    rxFrame = ETH_GetReceivedFrame();
    
    if ((rxFrame.length == 0) && (rxFrame.buffer == 0))
    {
        return NULL;
    }
    
    /* Obtain the size of the packet and put it into the "len" variable. */
    frameLen = rxFrame.length;
    pBuffer  = (uint8_t *)rxFrame.buffer;

    /* We allocate a pbuf chain of pbufs from the pool. */
    p = pbuf_alloc(PBUF_RAW, frameLen, PBUF_POOL);

    /* Copy received frame from ethernet driver buffer to stack buffer */
    if (p != NULL)
    {
        /* Point to first descriptor */
        DMARxDesc = DMARxFrameInfos->FirstSegmentRxDesc;
        bufferOffset = 0;
        for (q = p; q != NULL; q = q->next)
        {
            /* Get bytes in current lwIP buffer */
            bytesCurrentBuffer = q->len;
            payloadOffset = 0;

            /* Check if the length of bytes to copy in current pbuf is bigger than Rx buffer size*/
            while ((bytesCurrentBuffer + bufferOffset) > ETH_RX_BUF_SIZE)
            {
                /* Copy data to pbuf */
                memcpy((uint8_t*)((uint8_t*)q->payload + payloadOffset), (uint8_t*)((uint8_t*)pBuffer + bufferOffset), (ETH_RX_BUF_SIZE - bufferOffset));

                /* Point to next descriptor */
                DMARxDesc = (ETH_DMADescType *)(DMARxDesc->Buf2OrNextDescAddr);
                pBuffer = (uint8_t *)(DMARxDesc->Buf1Addr);

                bytesCurrentBuffer = bytesCurrentBuffer - (ETH_RX_BUF_SIZE - bufferOffset);
                payloadOffset = payloadOffset + (ETH_RX_BUF_SIZE - bufferOffset);
                bufferOffset = 0;
            }
            /* Copy remaining data in pbuf */
            memcpy((uint8_t*)((uint8_t*)q->payload + payloadOffset), (uint8_t*)((uint8_t*)pBuffer + bufferOffset), bytesCurrentBuffer);
            bufferOffset = bufferOffset + bytesCurrentBuffer;
        }
    }

    /* Release descriptors to DMA */
    /* Check if received frame with multiple DMA buffer segments */
    /* Point to first descriptor */
    DMARxDesc = DMARxFrameInfos->FirstSegmentRxDesc;
    /* Set Own bit in Rx descriptors: gives the buffers back to DMA */
    for (Index = 0; Index < DMARxFrameInfos->SegmentCount; Index++)
    {  
        DMARxDesc->Status |= ETH_DMA_RX_DESC_OWN;
        DMARxDesc = (ETH_DMADescType *)(DMARxDesc->Buf2OrNextDescAddr);
    }

    /* Clear Segment Count */
    DMARxFrameInfos->SegmentCount = 0;

    /* When Rx Buffer unavailable flag is set: clear it and resume reception */
    if ((ETH->DMASTS & ETH_DMASTS_RU) != (uint32_t)RESET)
    {
        /* Clear RBUS ETHERNET DMA flag */
        ETH->DMASTS = ETH_DMASTS_RU;

        /* Resume DMA reception */
        ETH->DMARXPD = 0;
    }

    return p;
}

/**
 * This function should be called when a packet is ready to be read
 * from the interface. It uses the function low_level_input() that
 * should handle the actual reception of bytes from the network
 * interface. Then the type of the received packet is determined and
 * the appropriate input function is called.
 *
 * @param netif the lwip network interface structure for this ethernetif
 */
void ethernetif_input(void *pArg)
{
    struct netif *netif;
    struct pbuf *p = NULL;
    netif = (struct netif *)pArg;
    
    while (1)
    {
        if (xSemaphoreTake(SemHandle, portMAX_DELAY) == pdTRUE)
        {
            taskENTER_CRITICAL();
            /* Move received packet into a new pbuf */
            p = low_level_input(netif);
            taskEXIT_CRITICAL();
            
            /* If no packet could be read, silently ignore this */
            if (p != NULL)
            {
                /* Pass all packets to ethernet_input, which decides what packets it supports */
                if (netif->input(p, netif) != ERR_OK)
                {
                    LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_input: IP input error\n"));
                    pbuf_free(p);
                    p = NULL;
                }
            }
        }
    }
}

/**
 * Should be called at the beginning of the program to set up the
 * network interface. It calls the function low_level_init() to do the
 * actual setup of the hardware.
 *
 * This function should be passed as a parameter to netif_add().
 *
 * @param netif the lwip network interface structure for this ethernetif
 * @return ERR_OK if the loopif is initialized
 *         ERR_MEM if private data couldn't be allocated
 *         any other err_t on error
 */
err_t ethernetif_init(struct netif *netif)
{
    struct ethernetif *ethernetif;

    LWIP_ASSERT("netif != NULL", (netif != NULL));

    ethernetif = mem_malloc(sizeof(struct ethernetif));
    if (ethernetif == NULL)
    {
        LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_init: out of memory\n"));
        return ERR_MEM;
    }

#if LWIP_NETIF_HOSTNAME
    /* Initialize interface hostname */
    netif->hostname = "lwip";
#endif /* LWIP_NETIF_HOSTNAME */

    /*
    * Initialize the snmp variables and counters inside the struct netif.
    * The last argument should be replaced with your link speed, in units
    * of bits per second.
    */
//    MIB2_INIT_NETIF(netif, snmp_ifType_ethernet_csmacd, LINK_SPEED_OF_YOUR_NETIF_IN_BPS);

    netif->state = ethernetif;
    netif->name[0] = IFNAME0;
    netif->name[1] = IFNAME1;

    /*
    * We directly use etharp_output() here to save a function call.
    * You can instead declare your own function an call etharp_output()
    * from it if you have to do some checks before sending (e.g. if link
    * is available...)
    */
#if LWIP_IPV4
    netif->output = etharp_output;
#endif /* LWIP_IPV4 */
#if LWIP_IPV6
    netif->output_ip6 = ethip6_output;
#endif /* LWIP_IPV6 */
    netif->linkoutput = low_level_output;

    /* Initialize the hardware */
    low_level_init(netif);
    
    ethernetif->ethaddr = (struct eth_addr *) &(netif->hwaddr[0]);

    return ERR_OK;
}

