src/hardware/parport/directlpt_linux.cpp

/*
 *  Copyright (C) 2002-2020  The DOSBox Team
 *
 *  This program 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 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */


#include "config.h"
#include "setup.h"

#if C_DIRECTLPT

/* Linux version */
#if defined (LINUX)

#include "parport.h"
#include "directlpt_linux.h"
#include "callback.h"
#include <linux/ppdev.h>
#include <sys/ioctl.h>
#include <sys/types.h>

#include <errno.h>
#include <fcntl.h>
#include <SDL.h>

CDirectLPT::CDirectLPT (Bitu nr, Bit8u initIrq, CommandLine* cmd)
                              :CParallel (cmd, nr, initIrq) {
        InstallationSuccessful = false;
        interruptflag=true; // interrupt disabled

        std::string str;

        if(!cmd->FindStringBegin("realport:",str,false)) {
                LOG_MSG("parallel%d: realport parameter missing.",(int)nr+1);
                return;
        }
        porthandle = open(str.c_str(), O_RDWR );
        if(porthandle == -1) {
                LOG_MSG("parallel%d: Could not open port %s.",(int)nr+1,str.c_str());
                if (errno == 2) LOG_MSG ("The specified port does not exist.");
                else if(errno==EBUSY) LOG_MSG("The specified port is already in use.");
                else if(errno==EACCES) LOG_MSG("You are not allowed to access this port.");
                else LOG_MSG("Errno %d occurred.",errno);
                return;
        }

        if(ioctl( porthandle, PPCLAIM, NULL ) == -1) {
                LOG_MSG("parallel%d: failed to claim port.",(int)nr+1);
                return;
        }
        // TODO check return value
        
        // go for it
        ack_polarity=false;
        initialize();

        InstallationSuccessful = true;
}

CDirectLPT::~CDirectLPT () {
        if(porthandle > 0) close(porthandle);
}

bool CDirectLPT::Putchar(Bit8u val)
{       
        //LOG_MSG("putchar: %x",val);

        // check if printer online and not busy
        // PE and Selected: no printer attached
        Bit8u sr=Read_SR();
        //LOG_MSG("SR: %x",sr);
        if((sr&0x30)==0x30)
        {
                LOG_MSG("putchar: no printer");
                return false;
        }
        // error
        if(sr&0x20)
        {
                LOG_MSG("putchar: paper out");
                return false;
        }
        if((sr&0x08)==0)
        {
                LOG_MSG("putchar: printer error");
                return false;
        }

        Write_PR(val);
        // busy
        Bitu timeout = 10000;
        Bitu time = timeout+SDL_GetTicks();

        while(SDL_GetTicks()<time) {
                // wait for the printer to get ready
                for(int i = 0; i < 500; i++) {
                        // do NOT run into callback_idle unless we have to (speeds things up)
                        sr=Read_SR();
                        if(sr&0x80) break;
                }
                if(sr&0x80) break;
                CALLBACK_Idle();
        }
        if(SDL_GetTicks()>=time) {
                LOG_MSG("putchar: busy timeout");
                return false;
        }
        // strobe data out
        // I hope this creates a sufficient long pulse...
        // (I/O-Bus at 7.15 MHz will give some delay)
        
        for(int i = 0; i < 5; i++) Write_CON(0xd); // strobe on
        Write_CON(0xc); // strobe off

#if PARALLEL_DEBUG
        log_par(dbg_putchar,"putchar  0x%2x",val);
        if(dbg_plainputchar) fprintf(debugfp,"%c",val);
#endif

        return true;
}
Bitu CDirectLPT::Read_PR() {
        Bitu retval;
        ioctl(porthandle, PPRDATA, &retval);
        return retval;
}
Bitu CDirectLPT::Read_COM() {
        Bitu retval;
        ioctl(porthandle, PPRCONTROL, &retval);
        return retval;
}
Bitu CDirectLPT::Read_SR() {
        Bitu retval;
        ioctl(porthandle, PPRSTATUS, &retval);
        return retval;
}

void CDirectLPT::Write_PR(Bitu val){
        ioctl(porthandle, PPWDATA, &val); 
}
void CDirectLPT::Write_CON(Bitu val) {
        ioctl(porthandle, PPWCONTROL, &val); 
}
void CDirectLPT::Write_IOSEL(Bitu val) {
        // switches direction old-style TODO
        if((val==0xAA)||(val==0x55)) LOG_MSG("TODO implement IBM-style direction switch");
}
void CDirectLPT::handleUpperEvent(Bit16u type) { (void)type; }
#endif
#endif