/*
 * 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 "conf_eth.h"

#include "netif/etharp.h"

/* FreeRTOS includes. */
#include "FreeRTOS.h"
#include "macb.h"

#define netifMTU              ( 1500 )
#define netifGUARD_BLOCK_TIME       ( 250 )
#define IFNAME0 'e'
#define IFNAME1 'm'


struct ethernetif {
  struct eth_addr *ethaddr;
  /* Add whatever per-interface state that is needed here. */
};

static const struct eth_addr ethbroadcast = {{0xff,0xff,0xff,0xff,0xff,0xff}};

/* Forward declarations. */
void  ethernetif_input(void * );
static err_t ethernetif_output(struct netif *netif, struct pbuf *p,
             struct ip_addr *ipaddr);
static struct netif *xNetIf = NULL;


static void
low_level_init(struct netif *netif)
{
//  struct ethernetif *ethernetif = netif->state;
  unsigned portBASE_TYPE uxPriority;

  /* maximum transfer unit */
  netif->mtu = netifMTU;
  
  /* broadcast capability */
  netif->flags = NETIF_FLAG_BROADCAST;
 
  /* Do whatever else is needed to initialize interface. */  
  xNetIf = netif;

  /* Initialise the MACB.  This routine contains code that polls status bits.
  If the Ethernet cable is not plugged in then this can take a considerable
  time.  To prevent this starving lower priority tasks of processing time we
  lower our priority prior to the call, then raise it back again once the
  initialisation is complete. */
  uxPriority = uxTaskPriorityGet( NULL );
  vTaskPrioritySet( NULL, tskIDLE_PRIORITY );
  while( xMACBInit(&AVR32_MACB) == FALSE )
  {
    __asm__ __volatile__ ( "nop" );
  }
  vTaskPrioritySet( NULL, uxPriority );

  /* Create the task that handles the MACB. */
  // xTaskCreate( ethernetif_input, ( signed portCHAR * ) "ETH_INT", netifINTERFACE_TASK_STACK_SIZE, NULL, netifINTERFACE_TASK_PRIORITY, NULL );
  sys_thread_new( ethernetif_input, NULL, netifINTERFACE_TASK_PRIORITY );
}

/*
 * low_level_output():
 *
 * 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.
 *
 */

static err_t
low_level_output(struct netif *netif, struct pbuf *p)
{
struct pbuf *q;
static xSemaphoreHandle xTxSemaphore = NULL;
err_t xReturn = ERR_OK;

  /* Parameter not used. */
  ( void ) netif;

  if( xTxSemaphore == NULL )
  {
    vSemaphoreCreateBinary( xTxSemaphore );
  }

  #if ETH_PAD_SIZE
    pbuf_header( p, -ETH_PAD_SIZE );    /* drop the padding word */
  #endif

  /* Access to the MACB is guarded using a semaphore. */
  if( xSemaphoreTake( xTxSemaphore, netifGUARD_BLOCK_TIME ) )
  {
    for( q = p; q != NULL; q = q->next )
    {
      /* Send the data from the pbuf to the interface, one pbuf at a
      time. The size of the data in each pbuf is kept in the ->len
      variable.  if q->next == NULL then this is the last pbuf in the
      chain. */
      if( !lMACBSend(&AVR32_MACB, q->payload, q->len, ( q->next == NULL ) ) )
      {
        xReturn = ~ERR_OK;
      }
    }
    xSemaphoreGive( xTxSemaphore );
  }
  

  #if ETH_PAD_SIZE
    pbuf_header( p, ETH_PAD_SIZE );     /* reclaim the padding word */
  #endif

  #if LINK_STATS
    lwip_stats.link.xmit++;
  #endif /* LINK_STATS */

    return xReturn;
}

/*
 * low_level_input():
 *
 * Should allocate a pbuf and transfer the bytes of the incoming
 * packet from the interface into the pbuf.
 *
 */

static struct pbuf *
low_level_input(struct netif *netif) {
struct pbuf         *p = NULL;
struct pbuf         *q;
u16_t               len = 0;
static xSemaphoreHandle xRxSemaphore = NULL;

  /* Parameter not used. */
  ( void ) netif;

  if( xRxSemaphore == NULL )
  {
    vSemaphoreCreateBinary( xRxSemaphore );
  }

  /* Access to the emac is guarded using a semaphore. */
  if( xSemaphoreTake( xRxSemaphore, netifGUARD_BLOCK_TIME ) )
  {
    /* Obtain the size of the packet. */
    len = ulMACBInputLength();

    if( len )
    {
      #if ETH_PAD_SIZE
        len += ETH_PAD_SIZE;    /* allow room for Ethernet padding */
      #endif
  
      /* We allocate a pbuf chain of pbufs from the pool. */
      p = pbuf_alloc( PBUF_RAW, len, PBUF_POOL );
  
      if( p != NULL )
      {
        #if ETH_PAD_SIZE
          pbuf_header( p, -ETH_PAD_SIZE );    /* drop the padding word */
        #endif
  
        /* Let the driver know we are going to read a new packet. */
        vMACBRead( NULL, 0, len );
  
        /* We iterate over the pbuf chain until we have read the entire
        packet into the pbuf. */
        for( q = p; q != NULL; q = q->next )
        {
          /* Read enough bytes to fill this pbuf in the chain. The
          available data in the pbuf is given by the q->len variable. */
          vMACBRead( q->payload, q->len, len );
        }
  
        #if ETH_PAD_SIZE
          pbuf_header( p, ETH_PAD_SIZE );     /* reclaim the padding word */
        #endif
        #if LINK_STATS
          lwip_stats.link.recv++;
        #endif /* LINK_STATS */
      }
      else
      {
        #if LINK_STATS
          lwip_stats.link.memerr++;
          lwip_stats.link.drop++;
        #endif /* LINK_STATS */
      }
    }
    xSemaphoreGive( xRxSemaphore );
  }

  return p;
}

/*
 * ethernetif_output():
 *
 * This function is called by the TCP/IP stack when an IP packet
 * should be sent. It calls the function called low_level_output() to
 * do the actual transmission of the packet.
 *
 */

static err_t
ethernetif_output(struct netif *netif, struct pbuf *p,
      struct ip_addr *ipaddr)
{
  
 /* resolve hardware address, then send (or queue) packet */
  return etharp_output(netif, ipaddr, p);
 
}

/*
 * ethernetif_input():
 *
 * 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.
 *
 */

void ethernetif_input( void * pvParameters )
{
struct ethernetif   *ethernetif;
struct eth_hdr      *ethhdr;
struct pbuf         *p;

  ( void ) pvParameters;

  for( ;; )  {
   
    ethernetif = xNetIf->state;
    do
    {
      ethernetif = xNetIf->state;

      /* move received packet into a new pbuf */
      p = low_level_input( xNetIf );

      if( p == NULL )
      {
        /* No packet could be read.  Wait a for an interrupt to tell us
        there is more data available. */
        vMACBWaitForInput(100);
      }

    } while( p == NULL );

    /* points to packet payload, which starts with an Ethernet header */
    ethhdr = p->payload;
  
    #if LINK_STATS
      lwip_stats.link.recv++;
    #endif /* LINK_STATS */
  
    ethhdr = p->payload;
  
    switch( htons( ethhdr->type ) )
    {
      /* IP packet? */
      case ETHTYPE_IP:
        /* update ARP table */
        etharp_ip_input( xNetIf, p );
  
        /* skip Ethernet header */
        pbuf_header( p, (s16_t)-sizeof(struct eth_hdr) );
  
        /* pass to network layer */
        xNetIf->input( p, xNetIf );
        break;
  
      case ETHTYPE_ARP:
        /* pass p to ARP module */
        etharp_arp_input( xNetIf, ethernetif->ethaddr, p );
        break;
  
      default:
        pbuf_free( p );
        p = NULL;
        break;
    }
  }
}

static void
arp_timer(void *arg)
{
  etharp_tmr();
  sys_timeout(ARP_TMR_INTERVAL, arp_timer, NULL);
}

/*
 * ethernetif_init():
 *
 * 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.
 *
 */
extern struct netif MACB_if;
err_t
ethernetif_init(struct netif *netif)
{
  struct ethernetif *ethernetif;
  int i;
    
  ethernetif = (struct ethernetif *)mem_malloc(sizeof(struct ethernetif));
  
  if (ethernetif == NULL)
  {
    LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_init: out of memory\n"));
    return ERR_MEM;
  }
  
  netif->state = ethernetif;
  netif->name[0] = IFNAME0;
  netif->name[1] = IFNAME1;
  netif->output = ethernetif_output;
  netif->linkoutput = low_level_output;
  
  for(i = 0; i < 6; i++) netif->hwaddr[i] = MACB_if.hwaddr[i];
  
  low_level_init(netif);

  etharp_init();

  sys_timeout(ARP_TMR_INTERVAL, arp_timer, NULL);

  return ERR_OK;
}