/* This file is in the public domain. */

/* driver for the console slu at 1777746x, vectors 60 (rx) and 64 (tx) */

#include <stdio.h>
#include <fcntl.h>
#include <signal.h>
#include <unistd.h>
#include <termios.h>
#include <sys/ioctl.h>

#include "driver.h"

#include "cons__.h"

#define TICKS_PER_WRITE 20

#define CONS_ODT_CHAR 0x10 /* ^P - breaks back to ODT */

static char cons_in_char;
static char cons_out_char;
static word cons_in_stat;
static word cons_out_stat;
#define CONS_IE      0x40
#define CONS_READY   0x80
#define CONS_MUTABLE (CONS_IE)
static int state;
#define DIDINT_IN  0x00000001
#define DIDINT_OUT 0x00000002
#define PRINTING   0x00000004
static int printtime;
static int sigio;
static struct termios old_tty;
static struct termios new_tty;

extern DRIVER cons_driver;

#define WANTINT(statword) (((statword) & (CONS_IE|CONS_READY)) == (CONS_IE|CONS_READY))

static void chkint(void)
{
 if (WANTINT(cons_in_stat) && !(state & DIDINT_IN))
  { interrupt(&cons_driver,060,BR4);
    state |= DIDINT_IN;
  }
 if (WANTINT(cons_out_stat) && !(state & DIDINT_OUT))
  { interrupt(&cons_driver,064,BR4);
    state |= DIDINT_OUT;
  }
}

static void cons_tick(DRIVER *); /* forward */

static void getticks(void)
{
 cons_driver.tick = cons_tick;
}

static void startprinting(void)
{
 write(1,&cons_out_char,1);
 state |= PRINTING;
 printtime = TICKS_PER_WRITE;
 getticks();
 cons_out_stat |= CONS_READY;
 chkint();
}

static void cons_tick(UNUSED(DRIVER *d))
{
 int mask;

 cons_driver.tick = 0;
 if (printtime > 0)
  { if (halted) printtime = 0; else printtime --;
    if (printtime <= 0)
     { if (! (cons_out_stat & CONS_READY))
	{ startprinting();
	}
       else
	{ state &= ~PRINTING;
	}
     }
    else
     { getticks();
     }
  }
 if (sigio)
  { char ch;
    mask = sigblock(sigmask(SIGIO));
    if (read(0,&ch,1) == 1)
     { do
	{ if (ch == CONS_ODT_CHAR) halted = 1;
	} while (read(0,&ch,1) == 1);
       cons_in_char = ch;
       cons_in_stat |= CONS_READY;
       chkint();
     }
    sigio = 0;
    sigsetmask(mask);
  }
}

static void cons__sigio(UNUSED(int sig))
{
 sigio ++;
 getticks();
}

static void cons__sigint(UNUSED(int sig))
{
 halted = 1;
}

static void cons_init(UNUSED(DRIVER *d), char *iomask)
{
 int on;
 struct termios tio;

 iomask[IOMASK(0777560)] = 1; /* keyboard status */
 iomask[IOMASK(0777562)] = 1; /* keyboard data */
 iomask[IOMASK(0777564)] = 1; /* printer status */
 iomask[IOMASK(0777566)] = 1; /* printer data */
 cons_in_stat = 0;
 cons_out_stat = CONS_READY;
 state = 0;
 signal(SIGINT,cons__sigint);
 signal(SIGIO,cons__sigio);
 tcgetattr(0,&tio);
 old_tty = tio;
 cfmakeraw(&tio);
 tio.c_cc[VMIN] = 1;
 tio.c_cc[VTIME] = 0;
 new_tty = tio;
 tcsetattr(0,TCSADRAIN,&tio);
 on = 1;
 ioctl(0,FIONBIO,&on);
 ioctl(0,FIOASYNC,&on);
 fcntl(0,F_SETOWN,getpid());
}

static void cons_printchar(char c)
{
 state &= ~DIDINT_OUT;
 cons_out_char = c;
 cons_out_stat &= ~CONS_READY;
 if (! (state & PRINTING)) startprinting();
}

static int cons_io(UNUSED(DRIVER *d), int loc, int op, int data, UNUSED(void (*fxn)(void *)))
{
 int rv;

 rv = 0;
 switch (loc)
  { case IOMASK(0777560): /* keyboard status */
       rv = reg_access(loc,&cons_in_stat,op,~CONS_MUTABLE,data);
       chkint();
       break;
    case IOMASK(0777562): /* keyboard data */
       if ((op & IO_OP) == IO_R)
	{ cons_in_stat &= ~CONS_READY;
	  state &= ~DIDINT_IN;
	  rv = cons_in_char;
	}
       break;
    case IOMASK(0777564): /* printer status */
       rv = reg_access(loc,&cons_out_stat,op,~CONS_MUTABLE,data);
       chkint();
       break;
    case IOMASK(0777566): /* printer data */
       switch (op & IO_OP)
	{ case IO_W:
	     cons_printchar(data);
	     break;
	}
       break;
  }
 return(rv);
}

static void cons_busreset(UNUSED(DRIVER *d))
{
 cons_in_stat = 0;
 cons_out_stat = CONS_READY;
 state = 0;
}

static void cons_reset(UNUSED(DRIVER *d))
{
}

static int cons_intchk(INTRQ *irq)
{
 return((irq->vec == 060) ? WANTINT(cons_in_stat) : WANTINT(cons_out_stat));
}

DRIVER cons_driver = { DVR_NORMW, "console", cons_init, cons_tick, cons_io, cons_busreset, cons_reset, cons_intchk, 0 };

void cons__reset(void) /* called by odt when pausing or exiting */
{
 int off;

 tcsetattr(0,TCSANOW,&old_tty);
 off = 0;
 ioctl(0,FIONBIO,&off);
 ioctl(0,FIOASYNC,&off);
}

void cons__resume(void) /* called by odt when resuming */
{
 int on;

 tcsetattr(0,TCSANOW,&new_tty);
 on = 1;
 ioctl(0,FIONBIO,&on);
 ioctl(0,FIOASYNC,&on);
}

void cons__flush(void) /* called by odt to flush buffered character(s) */
{
 cons_tick(&cons_driver);
 cons_tick(&cons_driver);
}