/*******************************************************************************
    OpenAirInterface
    Copyright(c) 1999 - 2014 Eurecom

    OpenAirInterface is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.


    OpenAirInterface is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with OpenAirInterface.The full GNU General Public License is
   included in this distribution in the file called "COPYING". If not,
   see <http://www.gnu.org/licenses/>.

  Contact Information
  OpenAirInterface Admin: openair_admin@eurecom.fr
  OpenAirInterface Tech : openair_tech@eurecom.fr
  OpenAirInterface Dev  : openair4g-devel@eurecom.fr

  Address      : Eurecom, Compus SophiaTech 450, route des chappes, 06451 Biot, France.

*******************************************************************************/

/*! \file device.c
* \brief Networking Device Driver for OpenAirInterface
* \author  navid nikaein,  Lionel Gauthier, raymond knopp
* \company Eurecom
* \email: raymond.knopp@eurecom.fr, navid.nikaein@eurecom.fr, lionel.gauthier@eurecom.fr

*/
/*******************************************************************************/

#ifndef OAI_NW_DRIVER_USE_NETLINK
#ifdef RTAI
#include "rtai_posix.h"
#define RTAI_IRQ 30 //try to get this irq with RTAI
#endif // RTAI
#endif // OAI_NW_DRIVER_USE_NETLINK

#include "constant.h"
#include "local.h"
#include "proto_extern.h"

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/moduleparam.h>
#include <asm/io.h>
#include <asm/bitops.h>
#include <asm/uaccess.h>
#include <asm/segment.h>
#include <asm/page.h>
#include <asm/delay.h>
#include <asm/unistd.h>
#include <linux/netdevice.h>



struct net_device *ue_ip_dev[UE_IP_NB_INSTANCES_MAX];

#ifdef OAI_NW_DRIVER_USE_NETLINK
extern void ue_ip_netlink_release(void);
extern int ue_ip_netlink_init(void);
#endif

//---------------------------------------------------------------------------
int ue_ip_find_inst(struct net_device *dev_pP) {
//---------------------------------------------------------------------------
  int i;

  for (i=0;i<UE_IP_NB_INSTANCES_MAX;i++)
    if (ue_ip_dev[i] == dev_pP)
      return(i);
  return(-1);
}

//---------------------------------------------------------------------------

#ifndef OAI_NW_DRIVER_USE_NETLINK
void *ue_ip_interrupt(void){
  //---------------------------------------------------------------------------
  uint8_t cxi;

  //  ue_ip_priv_t *priv_p=netdev_priv(dev_id);
  //  unsigned int flags;
  //  priv_p->lock = SPIN_LOCK_UNLOCKED;

#ifdef OAI_DRV_DEBUG_INTERRUPT
  printk("INTERRUPT - begin\n");
#endif
  //  spin_lock_irqsave(&priv_p->lock,flags);
  cxi=0;
  //    mesh_GC_receive();
  //    mesh_DC_receive(naspriv->cx+cxi);
#ifndef OAI_NW_DRIVER_USE_NETLINK
  ue_ip_common_wireless2ip();
#endif
  //  spin_unlock_irqrestore(&priv_p->lock,flags);
#ifdef OAI_DRV_DEBUG_INTERRUPT
  printk("INTERRUPT: end\n");
#endif
  //  return 0;
}
#endif //NETLINK
//---------------------------------------------------------------------------
void ue_ip_timer(unsigned long dataP){
  //---------------------------------------------------------------------------
  ue_ip_priv_t *priv_p=(ue_ip_priv_t *)dataP;
  spin_lock(&priv_p->lock);
  (priv_p->timer).function=ue_ip_timer;
  (priv_p->timer).expires=jiffies+UE_IP_TIMER_TICK;
  (priv_p->timer).data=dataP;
  add_timer(&priv_p->timer);
  spin_unlock(&priv_p->lock);
  return;
//  add_timer(&gpriv->timer);
//  spin_unlock(&gpriv->lock);
}

//---------------------------------------------------------------------------
// Called by ifconfig when the device is activated by ifconfig
int ue_ip_open(struct net_device *dev_pP){
  //---------------------------------------------------------------------------
  ue_ip_priv_t *priv_p=netdev_priv(dev_pP);

  // Address has already been set at init
#ifndef OAI_NW_DRIVER_USE_NETLINK
  if (pdcp_2_ue_ip_irq==-EBUSY){
      printk("[UE_IP_DRV][%s] : irq failure\n", __FUNCTION__);
      return -EBUSY;
  }
#endif //OAI_NW_DRIVER_USE_NETLINK

  if(!netif_queue_stopped(dev_pP))
      netif_start_queue(dev_pP);
  else
      netif_wake_queue(dev_pP);

  init_timer(&priv_p->timer);
  (priv_p->timer).expires   = jiffies+UE_IP_TIMER_TICK;
  (priv_p->timer).data      = (unsigned long)priv_p;
  (priv_p->timer).function  = ue_ip_timer;
  //add_timer(&priv_p->timer);

  printk("[UE_IP_DRV][%s] name = %s\n", __FUNCTION__, dev_pP->name);
  return 0;
}

//---------------------------------------------------------------------------
// Called by ifconfig when the device is desactivated
int ue_ip_stop(struct net_device *dev_pP){
  //---------------------------------------------------------------------------
  ue_ip_priv_t *priv_p = netdev_priv(dev_pP);

  printk("[UE_IP_DRV][%s] Begin\n", __FUNCTION__);
  del_timer(&(priv_p->timer));
  netif_stop_queue(dev_pP);
  //    MOD_DEC_USE_COUNT;
  printk("[UE_IP_DRV][%s] End\n", __FUNCTION__);
  return 0;
}

//---------------------------------------------------------------------------
void ue_ip_teardown(struct net_device *dev_pP){
  //---------------------------------------------------------------------------
  ue_ip_priv_t    *priv_p;
  int              inst;

  printk("[UE_IP_DRV][%s] Begin\n", __FUNCTION__);
  if (dev_pP) {
      priv_p = netdev_priv(dev_pP);
      inst = ue_ip_find_inst(dev_pP);
      if ((inst<0) || (inst>=UE_IP_NB_INSTANCES_MAX)) {
          printk("[UE_IP_DRV][%s] ERROR, couldn't find instance\n", __FUNCTION__);
          return;
      }


      printk("[UE_IP_DRV][%s] End\n", __FUNCTION__);
  } // check dev_pP
  else {
      printk("[UE_IP_DRV][%s] Device is null\n", __FUNCTION__);
  }
}
//---------------------------------------------------------------------------
int ue_ip_set_config(struct net_device *dev_pP, struct ifmap *map_pP){
  //---------------------------------------------------------------------------
  printk("[UE_IP_DRV][%s] Begin\n", __FUNCTION__);
  if (dev_pP->flags & IFF_UP)
      return -EBUSY;
  if (map_pP->base_addr != dev_pP->base_addr) {
      printk(KERN_WARNING "[UE_IP_DRV][%s] Can't change I/O address\n", __FUNCTION__);
      return -EOPNOTSUPP;
  }
  if (map_pP->irq != dev_pP->irq)
      dev_pP->irq = map_pP->irq;
  printk("[UE_IP_DRV][%s] End\n", __FUNCTION__);
  return 0;
}

//---------------------------------------------------------------------------
//
int ue_ip_hard_start_xmit(struct sk_buff *skb_pP, struct net_device *dev_pP){
  //---------------------------------------------------------------------------
  int inst;

  if (dev_pP) {
      inst = ue_ip_find_inst(dev_pP);
  } else {
      printk("[UE_IP_DRV][%s] ERROR, device is null\n", __FUNCTION__);
      return -1;
  }

  if ((inst>=0) && (inst<UE_IP_NB_INSTANCES_MAX)) {
      #ifdef OAI_DRV_OAI_DRV_DEBUG_DEVICE
      printk("[UE_IP_DRV][%s] inst %d,  begin\n", __FUNCTION__,inst);
      #endif

      if (!skb_pP){
          printk("[UE_IP_DRV][%s] input parameter skb is NULL\n", __FUNCTION__);
          return -1;
      }
      // End debug information
      netif_stop_queue(dev_pP);
      dev_pP->trans_start = jiffies;
      #ifdef OAI_DRV_DEBUG_DEVICE
      printk("[UE_IP_DRV][%s] step 1\n", __FUNCTION__);
      #endif
      ue_ip_common_ip2wireless(skb_pP,inst);
      #ifdef OAI_DRV_DEBUG_DEVICE
      printk("[UE_IP_DRV][%s] step 2\n", __FUNCTION__);
      #endif
      dev_kfree_skb(skb_pP);
      #ifdef OAI_DRV_DEBUG_DEVICE
      printk("[UE_IP_DRV][%s] step 3\n", __FUNCTION__);
      #endif
      netif_wake_queue(dev_pP);
      #ifdef OAI_DRV_DEBUG_DEVICE
      printk("[UE_IP_DRV][%s] end\n", __FUNCTION__);
      #endif
  } else {
      printk("[UE_IP_DRV][%s] ERROR, couldn't find instance\n", __FUNCTION__);
      return(-1);
  }
  return 0;
}

//---------------------------------------------------------------------------
struct net_device_stats *ue_ip_get_stats(struct net_device *dev_pP){
//---------------------------------------------------------------------------
  ue_ip_priv_t *priv_p = netdev_priv(dev_pP);
  return &priv_p->stats;
}
//---------------------------------------------------------------------------
int ue_ip_set_mac_address(struct net_device *dev_pP, void *mac_pP) {
//---------------------------------------------------------------------------
  //struct sockaddr *addr = mac_pP;
  printk("[UE_IP_DRV][%s] CHANGE MAC ADDRESS UNSUPPORTED\n", __FUNCTION__);
  //memcpy(dev_pP->dev_addr, addr->sa_data, dev_pP->addr_len);
  return 0;
}
//---------------------------------------------------------------------------
int ue_ip_change_mtu(struct net_device *dev_pP, int mtuP){
  //---------------------------------------------------------------------------
  printk("[UE_IP_DRV][%s] CHANGE MTU %d bytes\n", __FUNCTION__, mtuP);
  if ((mtuP<50) || (mtuP>1500))
      return -EINVAL;
  dev_pP->mtu = mtuP;
  return 0;
}
//---------------------------------------------------------------------------
void ue_ip_change_rx_flags(struct net_device *dev_pP, int flagsP){
  //---------------------------------------------------------------------------
  ue_ip_priv_t *priv_p =  netdev_priv(dev_pP);
  printk("[UE_IP_DRV][%s] CHANGE RX FLAGS %08X\n", __FUNCTION__, flagsP);
  priv_p->rx_flags ^= flagsP;
}

//---------------------------------------------------------------------------
void ue_ip_tx_timeout(struct net_device *dev_pP){
  //---------------------------------------------------------------------------
  // Transmitter timeout, serious problems.
  ue_ip_priv_t *priv_p =  netdev_priv(dev_pP);

  printk("[UE_IP_DRV][%s] begin\n", __FUNCTION__);
  //  (ue_ip_priv_t *)(dev_pP->priv_p)->stats.tx_errors++;
  (priv_p->stats).tx_errors++;
  dev_pP->trans_start = jiffies;
  netif_wake_queue(dev_pP);
  printk("[UE_IP_DRV][%s] transmit timed out %s\n", __FUNCTION__,dev_pP->name);
}

static const struct net_device_ops ue_ip_netdev_ops = {
    .ndo_open               = ue_ip_open,
    .ndo_stop               = ue_ip_stop,
    .ndo_start_xmit         = ue_ip_hard_start_xmit,
    .ndo_validate_addr      = NULL,
    .ndo_get_stats          = ue_ip_get_stats,
    .ndo_set_mac_address    = ue_ip_set_mac_address,
    .ndo_set_config         = ue_ip_set_config,
    .ndo_do_ioctl           = NULL,
    .ndo_change_mtu         = ue_ip_change_mtu,
    .ndo_tx_timeout         = ue_ip_tx_timeout,
    .ndo_change_rx_flags    = ue_ip_change_rx_flags,
};
    /*.ndo_set_multicast_list = NULL,*/

//---------------------------------------------------------------------------
// Initialisation of the network device
void ue_ip_init(struct net_device *dev_pP){
  //---------------------------------------------------------------------------
  ue_ip_priv_t *priv_p = NULL;
    if (dev_pP) {
        priv_p = netdev_priv(dev_pP);
        memset(priv_p, 0, sizeof(ue_ip_priv_t));
        spin_lock_init(&priv_p->lock);
        #ifdef KERNEL_VERSION_GREATER_THAN_2629
        dev_pP->netdev_ops = &ue_ip_netdev_ops;
        #else
        #error "KERNEL VERSION MUST BE NEWER THAN 2.6.29"
        #endif
        dev_pP->hard_header_len = 0;
        dev_pP->addr_len = UE_IP_ADDR_LEN;
        dev_pP->flags = IFF_BROADCAST|IFF_MULTICAST|IFF_NOARP;
        dev_pP->tx_queue_len = UE_IP_TX_QUEUE_LEN;
        dev_pP->mtu = UE_IP_MTU;
    } else {
        printk("[UE_IP_DRV][%s] ERROR, Device is NULL!!\n", __FUNCTION__);
        return;
    }
}
//---------------------------------------------------------------------------
int init_module (void) {
//---------------------------------------------------------------------------
  int err,inst;
  char devicename[100];


  // Initialize parameters shared with RRC
  printk("[UE_IP_DRV][%s] Starting OAI IP driver", __FUNCTION__);

  for (inst=0;inst<UE_IP_NB_INSTANCES_MAX;inst++) {
    printk("[UE_IP_DRV][%s] begin init instance %d\n", __FUNCTION__,inst);
    sprintf(devicename,"oip%d",inst);
    ue_ip_dev[inst]  = alloc_netdev(sizeof(ue_ip_priv_t),devicename, ue_ip_init);
    //netif_stop_queue(ue_ip_dev[inst]);
    if (ue_ip_dev[inst] == NULL) {
         printk("[UE_IP_DRV][%s][INST %02d] alloc_netdev FAILED\n", __FUNCTION__,inst);
    } else {
        // linux/net/core/dev.c line 4767
        err= register_netdev(ue_ip_dev[inst]);
        if (err){
          printk("[UE_IP_DRV][%s] (inst %d): error %i registering device %s\n", __FUNCTION__, inst,err, ue_ip_dev[inst]->name);
        }else{
          printk("[UE_IP_DRV][%s] registering device %s, ifindex = %d\n\n", __FUNCTION__,ue_ip_dev[inst]->name, ue_ip_dev[inst]->ifindex);
        }
    }
  }

  printk("[UE_IP_DRV][%s] NETLINK INIT\n", __FUNCTION__);
  if ((err=ue_ip_netlink_init()) == -1)
    printk("[UE_IP_DRV][%s] NETLINK failed\n", __FUNCTION__);

  return err;

}

//---------------------------------------------------------------------------
void cleanup_module(void){
//---------------------------------------------------------------------------
    int inst;

    printk("[UE_IP_DRV][CLEANUP]nasmesh_cleanup_module: begin\n");

    for (inst=0;inst<UE_IP_NB_INSTANCES_MAX;inst++) {
#ifdef OAI_DRV_DEBUG_DEVICE
        printk("nasmesh_cleanup_module: unregister and free net device instance %d\n",inst);
#endif
        if (ue_ip_dev[inst]) {
            unregister_netdev(ue_ip_dev[inst]);
            ue_ip_teardown(ue_ip_dev[inst]);
            free_netdev(ue_ip_dev[inst]);
        }
    }
    ue_ip_netlink_release();
    printk("nasmesh_cleanup_module: end\n");
}

#define DRV_NAME        "ue_ip"
#define DRV_VERSION     "1.0"DRV_NAME
#define DRV_DESCRIPTION "OPENAIR UE IP Device Driver"
#define DRV_COPYRIGHT   "-Copyright(c) GNU GPL Eurecom 2013"
#define DRV_AUTHOR      "Lionel GAUTHIER: <firstname.name@eurecom.fr>"DRV_COPYRIGHT