/* 
 * Author: Josh Holtrop
 * Date: 2009-05-03
 * See VFD.h for documentation
 */

#include <stdio.h>                  /* perror() */
#include <unistd.h>                 /* usleep() */
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <linux/parport.h>
#include <linux/ppdev.h>
#include <iostream>
using namespace std;

#include "VFD.h"

VFD::VFD()
{
    m_ppfd = -1;
}

bool VFD::connect(const std::string & parport)
{
    const int mode = IEEE1284_MODE_BYTE;
    const int direction = 0;

    if ( (m_ppfd = open(parport.c_str(), O_RDWR)) < 0)
    {
        cerr << "Error opening '" << parport << "'";
        perror("");
    }
    else if (ioctl(m_ppfd, PPCLAIM, NULL))
    {
        perror("Could not claim parallel port");
    }
    else if (ioctl(m_ppfd, PPSETMODE, &mode))
    {
        perror("Could not set parallel port mode");
        ioctl(m_ppfd, PPRELEASE);
    }
    else if (ioctl(m_ppfd, PPDATADIR, &direction))
    {
        perror("Could not set parallel port direction");
        ioctl(m_ppfd, PPRELEASE);
    }
    else
    {
        return true;
    }

    if (m_ppfd >= 0)
    {
        close(m_ppfd);
        m_ppfd = -1;
    }
    return false;
}

void VFD::disconnect()
{
    if (m_ppfd >= 0)
    {
        ioctl(m_ppfd, PPRELEASE);
        close(m_ppfd);
        m_ppfd = -1;
    }
}

void VFD::setPPLines(unsigned char bits)
{
    if (m_ppfd >= 0)
    {
        ioctl(m_ppfd, PPWDATA, &bits);
    }
}

void VFD::sendNibble(unsigned char rs, unsigned char dat)
{
    setPPLines(  (rs << PP_OFFSET_RS)
               | (E_DISABLE << PP_OFFSET_E)
               | (RW_WRITE << PP_OFFSET_RW)
               | ((dat & 0xF) << PP_OFFSET_DATA) );
    usleep(1);
    setPPLines(  (rs << PP_OFFSET_RS)
               | (E_ENABLE << PP_OFFSET_E)
               | (RW_WRITE << PP_OFFSET_RW)
               | ((dat & 0xF) << PP_OFFSET_DATA) );
    usleep(1);
}

void VFD::sendByte(unsigned char rs, unsigned char dat)
{
    sendNibble(rs, (dat >> 4) & 0xF);
    sendNibble(rs, dat & 0xF);
}