/**
 * @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/def.h"
#include "lwip/mem.h"
#include "lwip/pbuf.h"
#include "lwip/sys.h"
#include <lwip/stats.h>
#include <lwip/snmp.h>
#include "netif/etharp.h"
#include "netif/ppp/pppoe.h"

//#include "err.h"
#include "lwip/err.h" // !!!!!!!!!!!!

#include "ethernetif.h"

#include "at32f435_437_emac.h"
#include <string.h>

/* TCP and ARP timeouts */
volatile int tcp_end_time, arp_end_time;

/* Define those to better describe your network interface. */
#define IFNAME0 'a'
#define IFNAME1 't'

#define EMAC_DMARxDesc_FrameLengthShift  16

/**
 * 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. */
    int unused;
};

/* Forward declarations. */
err_t ethernetif_input(struct netif *netif);

#define EMAC_RXBUFNB        4//4
#define EMAC_TXBUFNB        2//2

uint8_t MACaddr[6];
emac_dma_desc_type DMARxDscrTab[EMAC_RXBUFNB], DMATxDscrTab[EMAC_TXBUFNB];/* Ethernet Rx & Tx DMA Descriptors */
uint8_t Rx_Buff[EMAC_RXBUFNB][EMAC_MAX_PACKET_LENGTH], Tx_Buff[EMAC_TXBUFNB][EMAC_MAX_PACKET_LENGTH];/* Ethernet buffers */

extern emac_dma_desc_type *dma_tx_desc_to_set;
extern emac_dma_desc_type *dma_rx_desc_to_get;

typedef struct {
    u32 length;
    u32 buffer;
    emac_dma_desc_type *descriptor;
} FrameTypeDef;

FrameTypeDef emac_rxpkt_chainmode(void);

u32 emac_getcurrenttxbuffer(void);

error_status emac_txpkt_chainmode(u16 FrameLength);


/**
 * Setting the MAC address.
 *
 * @param netif the already initialized lwip network interface structure
 *        for this ethernetif
 */
void lwip_set_mac_address(uint8_t *macadd) {
    MACaddr[0] = macadd[0];
    MACaddr[1] = macadd[1];
    MACaddr[2] = macadd[2];
    MACaddr[3] = macadd[3];
    MACaddr[4] = macadd[4];
    MACaddr[5] = macadd[5];

    emac_local_address_set(macadd);
}


/**
 * 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) {
    /* set MAC hardware address length */
    netif->hwaddr_len = ETHARP_HWADDR_LEN;

    /* set MAC hardware address */
    netif->hwaddr[0] = MACaddr[0];
    netif->hwaddr[1] = MACaddr[1];
    netif->hwaddr[2] = MACaddr[2];
    netif->hwaddr[3] = MACaddr[3];
    netif->hwaddr[4] = MACaddr[4];
    netif->hwaddr[5] = MACaddr[5];

    /* maximum transfer unit */
    netif->mtu = 1500;

    /* device capabilities */
    /* don't set NETIF_FLAG_ETHARP if this device is not an ethernet one */
    netif->flags = NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP | NETIF_FLAG_LINK_UP;

    /* Initialize Tx Descriptors list: Chain Mode */
    emac_dma_descriptor_list_address_set(EMAC_DMA_TRANSMIT, DMATxDscrTab, &Tx_Buff[0][0], EMAC_TXBUFNB);
    /* Initialize Rx Descriptors list: Chain Mode  */
    emac_dma_descriptor_list_address_set(EMAC_DMA_RECEIVE, DMARxDscrTab, &Rx_Buff[0][0], EMAC_RXBUFNB);

    /* Enable Ethernet Rx interrrupt */
    {
        int i;
        for (i = 0; i < EMAC_RXBUFNB; i++) {
            emac_dma_rx_desc_interrupt_config(&DMARxDscrTab[i], TRUE);
        }
    }

    /* Enable MAC and DMA transmission and reception */
    emac_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 availale 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) {
    struct pbuf *q;
    int l = 0;
    u8 *buffer = (u8 *) emac_getcurrenttxbuffer();

    for (q = p; q != NULL; q = q->next) {
        memcpy((u8_t *) &buffer[l], q->payload, q->len);
        l = l + q->len;
    }

    if (emac_txpkt_chainmode(l) == ERROR) {
        return ERR_MEM;
    }

    return ERR_OK;
}

volatile uint32_t EMAC_COUNTER_DMARXDESC_DE = 0;                // desciptor error: no more descriptors for receive frame
volatile uint32_t EMAC_COUNTER_DMARXDESC_OE = 0;                // overflow error: frame was damaged due to buffer overflow
volatile uint32_t EMAC_COUNTER_DMARXDESC_IPV4HCE = 0;           // ipc checksum error: rx ipv4 header checksum error
volatile uint32_t EMAC_COUNTER_DMARXDESC_LC = 0;                // late collision occurred during reception
volatile uint32_t EMAC_COUNTER_DMARXDESC_RWT = 0;               // receive watchdog timeout: watchdog timer expired during reception
volatile uint32_t EMAC_COUNTER_DMARXDESC_RE = 0;                // receive error: error reported by mii interface
volatile uint32_t EMAC_COUNTER_DMARXDESC_CE = 0;                // crc error



#define EMAC_DMARXDESC_DE                ((uint32_t)0x00004000) /*!< desciptor error: no more descriptors for receive frame  */
#define EMAC_DMARXDESC_OE                ((uint32_t)0x00000800) /*!< overflow error: frame was damaged due to buffer overflow */
#define EMAC_DMARXDESC_IPV4HCE           ((uint32_t)0x00000080) /*!< ipc checksum error: rx ipv4 header checksum error   */
#define EMAC_DMARXDESC_LC                ((uint32_t)0x00000040) /*!< late collision occurred during reception   */
#define EMAC_DMARXDESC_RWT               ((uint32_t)0x00000010) /*!< receive watchdog timeout: watchdog timer expired during reception    */
#define EMAC_DMARXDESC_RE                ((uint32_t)0x00000008) /*!< receive error: error reported by mii interface  */
#define EMAC_DMARXDESC_CE                ((uint32_t)0x00000002) /*!< crc error */


/**
 * 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) {
    struct pbuf *p, *q;
    u16_t len;
    int l = 0;
    FrameTypeDef frame;
    u8 *buffer;

    p = NULL;
    frame = emac_rxpkt_chainmode();


    if ((frame.descriptor->status & EMAC_DMARXDESC_ES) == (u32) RESET) {

        /* Obtain the size of the packet and put it into the "len"
           variable. */
        len = frame.length;

        buffer = (u8 *) frame.buffer;

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

        if (p != NULL) {
            for (q = p; q != NULL; q = q->next) {
                memcpy((u8_t *) q->payload, (u8_t *) &buffer[l], q->len);
                l = l + q->len;
            }
        }

    } else {

        if ((frame.descriptor->status & EMAC_DMARXDESC_DE) != (u32) RESET)
            ++EMAC_COUNTER_DMARXDESC_DE;                // desciptor error: no more descriptors for receive frame
        if ((frame.descriptor->status & EMAC_DMARXDESC_OE) != (u32) RESET)
            ++EMAC_COUNTER_DMARXDESC_OE;                // overflow error: frame was damaged due to buffer overflow
        if ((frame.descriptor->status & EMAC_DMARXDESC_IPV4HCE) != (u32) RESET)
            ++EMAC_COUNTER_DMARXDESC_IPV4HCE;           // ipc checksum error: rx ipv4 header checksum error
        if ((frame.descriptor->status & EMAC_DMARXDESC_LC) != (u32) RESET)
            ++EMAC_COUNTER_DMARXDESC_LC;                // late collision occurred during reception
        if ((frame.descriptor->status & EMAC_DMARXDESC_RWT) != (u32) RESET)
            ++EMAC_COUNTER_DMARXDESC_RWT;               // receive watchdog timeout: watchdog timer expired during reception
        if ((frame.descriptor->status & EMAC_DMARXDESC_RE) != (u32) RESET)
            ++EMAC_COUNTER_DMARXDESC_RE;                // receive error: error reported by mii interface
        if ((frame.descriptor->status & EMAC_DMARXDESC_CE) != (u32) RESET)
            ++EMAC_COUNTER_DMARXDESC_CE;                // crc error
    }

    /* Set Own bit of the Rx descriptor Status: gives the buffer back to ETHERNET DMA */
    frame.descriptor->status = EMAC_DMARXDESC_OWN;

    /* When Rx Buffer unavailable flag is set: clear it and resume reception */
    if (emac_dma_flag_get(EMAC_DMA_RBU_FLAG)) {
        /* Clear RBUS ETHERNET DMA flag */
        emac_dma_flag_clear(EMAC_DMA_RBU_FLAG);
        /* Resume DMA reception */
        EMAC_DMA->rpd_bit.rpd = FALSE;
    }


    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
 */
err_t
ethernetif_input(struct netif *netif) {
    err_t err;
    struct pbuf *p;

    /* move received packet into a new pbuf */
    p = low_level_input(netif);

    /* no packet could be read, silently ignore this */
    if (p == NULL) return ERR_MEM;

    err = netif->input(p, netif);
    if (err != ERR_OK) {
        LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_input: IP input error\n"));
        pbuf_free(p);
        p = NULL;
    }

    return err;
}


err_t ethernetif_set_queue_input(struct netif *netif, osMessageQueueId_t EthDataQueue) {
    err_t err;
    struct pbuf *p;

    /* move received packet into a new pbuf */
    p = low_level_input(netif);

    /* no packet could be read, silently ignore this */
    if (p == NULL)
        return ERR_MEM;

    osStatus_t status = osMessageQueuePut(EthDataQueue, &p, 0x0, 0U);

    if (status != osOK)
        return ERR_MEM;

    return ERR_OK;
}

err_t ethernetif_get_queue_input(struct netif *netif, struct pbuf *p) {
    err_t err;

    /* no packet could be read, silently ignore this */
    if (p == NULL) return ERR_MEM;

    err = netif->input(p, netif);
    if (err != ERR_OK) {
        LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_input: IP input error\n"));
        pbuf_free(p);
        p = NULL;
    }

    return err;
}


/**
 * 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.
     */
            NETIF_INIT_SNMP(netif, snmp_ifType_ethernet_csmacd, 100000000);

    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...) */
    netif->output = etharp_output;
    netif->linkoutput = low_level_output;

    ethernetif->ethaddr = (struct eth_addr *) &(netif->hwaddr[0]);

    /* initialize the hardware */
    low_level_init(netif);

    return ERR_OK;
}

/*******************************************************************************
* Function Name  : emac_rxpkt_chainmode
* Description    : Receives a packet.
* Input          : None
* Output         : None
* Return         : frame: farme size and location
*******************************************************************************/
FrameTypeDef emac_rxpkt_chainmode(void) {
    u32 framelength = 0;
    FrameTypeDef frame = {0, 0};

    /* Check if the descriptor is owned by the ETHERNET DMA (when set) or CPU (when reset) */
    if ((dma_rx_desc_to_get->status & EMAC_DMARXDESC_OWN) != (u32) RESET) {
        frame.length = FALSE;

        if (emac_dma_flag_get(EMAC_DMA_RBU_FLAG)) {
            /* Clear RBUS ETHERNET DMA flag */
            emac_dma_flag_clear(EMAC_DMA_RBU_FLAG);
            /* Resume DMA reception */
            EMAC_DMA->rpd_bit.rpd = FALSE;
        }
        /* Return error: OWN bit set */
        return frame;
    }

    if (((dma_rx_desc_to_get->status & EMAC_DMATXDESC_ES) == (u32) RESET) &&
        ((dma_rx_desc_to_get->status & EMAC_DMARXDESC_LS) != (u32) RESET) &&
        ((dma_rx_desc_to_get->status & EMAC_DMARXDESC_FS) != (u32) RESET)) {
        /* Get the Frame Length of the received packet: substruct 4 bytes of the CRC */
        framelength = ((dma_rx_desc_to_get->status & EMAC_DMARXDESC_FL)
                >> EMAC_DMARxDesc_FrameLengthShift) - 4;

        /* Get the addrees of the actual buffer */
        frame.buffer = dma_rx_desc_to_get->buf1addr;
    } else {
        /* Return ERROR */
        framelength = FALSE;
    }

    frame.length = framelength;

    frame.descriptor = dma_rx_desc_to_get;

    /* Update the ETHERNET DMA global Rx descriptor with next Rx decriptor */
    /* Chained Mode */
    /* Selects the next DMA Rx descriptor list for next buffer to read */
    dma_rx_desc_to_get = (emac_dma_desc_type *) (dma_rx_desc_to_get->buf2nextdescaddr);
    /* Return Frame */
    return (frame);
}

/*******************************************************************************
* Function Name  : emac_txpkt_chainmode
* Description    : Transmits a packet, from application buffer, pointed by ppkt.
* Input          : - FrameLength: Tx Packet size.
* Output         : None
* Return         : ERROR: in case of Tx desc owned by DMA
*                  SUCCESS: for correct transmission
*******************************************************************************/
error_status emac_txpkt_chainmode(u16 FrameLength) {
    /* Check if the descriptor is owned by the ETHERNET DMA (when set) or CPU (when reset) */
    if ((dma_tx_desc_to_set->status & EMAC_DMATXDESC_OWN) != (u32) RESET) {
        /* Return ERROR: OWN bit set */
        return ERROR;
    }

    /* Setting the Frame Length: bits[12:0] */
    dma_tx_desc_to_set->controlsize = (FrameLength & EMAC_DMATXDESC_TBS1);

    /* Setting the last segment and first segment bits (in this case a frame is transmitted in one descriptor) */
    dma_tx_desc_to_set->status |= EMAC_DMATXDESC_LS | EMAC_DMATXDESC_FS;

    /* Set Own bit of the Tx descriptor Status: gives the buffer back to ETHERNET DMA */
    dma_tx_desc_to_set->status |= EMAC_DMATXDESC_OWN;
    /* When Tx Buffer unavailable flag is set: clear it and resume transmission */
    if (emac_dma_flag_get(EMAC_DMA_TBU_FLAG)) {
        /* Clear TBUS ETHERNET DMA flag */
        emac_dma_flag_clear(EMAC_DMA_TBU_FLAG);
        /* Resume DMA transmission*/
        EMAC_DMA->tpd_bit.tpd = 0;
    }

    /* Update the ETHERNET DMA global Tx descriptor with next Tx decriptor */
    /* Chained Mode */
    /* Selects the next DMA Tx descriptor list for next buffer to send */
    dma_tx_desc_to_set = (emac_dma_desc_type *) (dma_tx_desc_to_set->buf2nextdescaddr);
    /* Return SUCCESS */
    return SUCCESS;
}


/*******************************************************************************
* Function Name  : emac_getcurrenttxbuffer
* Description    : Return the address of the buffer pointed by the current descritor.
* Input          : None
* Output         : None
* Return         : Buffer address
*******************************************************************************/
u32 emac_getcurrenttxbuffer(void) {
    /* Return Buffer address */
    return (dma_tx_desc_to_set->buf1addr);
}
