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

  The following code is derived, directly or indirectly, from the SystemC
  source code Copyright (c) 1996-2008 by all Contributors.
  All Rights reserved.

  The contents of this file are subject to the restrictions and limitations
  set forth in the SystemC Open Source License Version 3.0 (the "License");
  You may not use this file except in compliance with such restrictions and
  limitations. You may obtain instructions on how to receive a copy of the
  License at http://www.systemc.org/. Software distributed by Contributors
  under the License is distributed on an "AS IS" basis, WITHOUT WARRANTY OF
  ANY KIND, either express or implied. See the License for the specific
  language governing rights and limitations under the License.

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

#ifndef __SIMPLE_LT_TARGET2_H__
#define __SIMPLE_LT_TARGET2_H__

#include "tlm.h"
#include "tlm_utils/passthrough_target_socket.h"
#include <cassert>
#include <vector>

class SimpleLTTarget2 : public sc_core::sc_module
{
public:
  typedef tlm::tlm_generic_payload             transaction_type;
  typedef tlm::tlm_phase                       phase_type;
  typedef tlm::tlm_sync_enum                   sync_enum_type;
  typedef tlm_utils::passthrough_target_socket<SimpleLTTarget2> target_socket_type;
  

public:
  target_socket_type socket;

public:
  SimpleLTTarget2(sc_core::sc_module_name name) :
    sc_core::sc_module(name),
    socket("socket")
  {
    // register nb_transport method
    socket.register_b_transport(this, &SimpleLTTarget2::myBTransport);
    socket.register_nb_transport_fw(this, &SimpleLTTarget2::myNBTransport);
    socket.register_get_direct_mem_ptr(this, &SimpleLTTarget2::myGetDMIPtr);

    // TODO: we don't register the transport_dbg callback here, so we
    // can test if something bad happens
    // REGISTER_DEBUGTRANSPORT(socket, transport_dbg, 0);
  }

  void myBTransport(transaction_type& trans,
                     sc_core::sc_time& t)
  {
    sc_dt::uint64 address = trans.get_address();
    assert(address < 400);

    unsigned int& data = *reinterpret_cast<unsigned int*>(trans.get_data_ptr());
    if (trans.get_command() == tlm::TLM_WRITE_COMMAND) {
      std::cout << name() << ": Received write request: A = 0x"
                << std::hex << (unsigned int)address
                << ", D = 0x" << data << std::dec
                << " @ " << sc_core::sc_time_stamp() << std::endl;

      *reinterpret_cast<unsigned int*>(&mMem[address]) = data;
      t += sc_core::sc_time(10, sc_core::SC_NS);

    } else {
      std::cout << name() << ": Received read request: A = 0x"
                << std::hex << (unsigned int)address << std::dec
                << " @ " << sc_core::sc_time_stamp() << std::endl;

      data = *reinterpret_cast<unsigned int*>(&mMem[address]);
      t += sc_core::sc_time(100, sc_core::SC_NS);
    }

    trans.set_response_status(tlm::TLM_OK_RESPONSE);

    trans.set_dmi_allowed(true);
  }

  sync_enum_type myNBTransport(transaction_type& trans,
                               phase_type& phase,
                               sc_core::sc_time& t)
  {
    assert(phase == tlm::BEGIN_REQ);

    // Never blocks, so call b_transport implementation
    myBTransport(trans, t);
    // LT target
    // - always return TLM_COMPLETED
    // - not necessary to update phase (if TLM_COMPLETED is returned)
    return tlm::TLM_COMPLETED;
  }

  unsigned int transport_dbg(transaction_type& r)
  {
    if (r.get_address() >= 400) return 0;

    unsigned int tmp = (int)r.get_address();
    unsigned int num_bytes;
    if (tmp + r.get_data_length() >= 400) {
      num_bytes = 400 - tmp;

    } else {
      num_bytes = r.get_data_length();
    }
    if (r.is_read()) {
      for (unsigned int i = 0; i < num_bytes; ++i) {
        r.get_data_ptr()[i] = mMem[i + tmp];
      }

    } else {
      for (unsigned int i = 0; i < num_bytes; ++i) {
        mMem[i + tmp] = r.get_data_ptr()[i];
      }
    }
    return num_bytes;
  }

  bool myGetDMIPtr(transaction_type& trans,
                   tlm::tlm_dmi&  dmi_data)
  {
    sc_dt::uint64 address = trans.get_address();
    if (address < 400) {
      dmi_data.allow_read_write();
      dmi_data.set_start_address(0x0);
      dmi_data.set_end_address(399);
      dmi_data.set_dmi_ptr(mMem);
      dmi_data.set_read_latency(sc_core::sc_time(100, sc_core::SC_NS));
      dmi_data.set_write_latency(sc_core::sc_time(10, sc_core::SC_NS));
      return true;

    } else {
      // should not happen
      dmi_data.set_start_address(address);
      dmi_data.set_end_address(address);
      return false;

    }
  }
private:
  unsigned char mMem[400];
};

#endif
