/*
>>:yam5scc.c 3-29-83
 *
 * Modem related functions.
 */

#include "yam.h"
#include "scc.h"

#define MIERROR (inpp(1)&(ROVERR+FRAMERR))
#define MI_ERROR_RESET outp(Sport, RESERROR)

#define BMAGIC 57600	/* 1.8432 mHz clock */
/*
 * setbaud(nbaud) If legal rate, set modem registers and Baudrate
 * Routine to init 8530 SCC, turn on DTR, and set baud rate
 *  Sets 2 stop bits iff baud rate is 110 baud or odd.
 *  Sets RTS iff baud rate >= 1100
 *  Steps performed in recommended squence according to Zilog Document
 *    00-2266-01 06/28/82
 * ********** N.B.: Resets entire chip  *************
 */
setbaud(nbaud)
unsigned nbaud;
{
	register unsigned bcmd;

	inp(Sport);	/* make sure register pointer is reset */
	outpp(9, RESCHIP);	/* reset the chip */
	if(nbaud==0)
		return ERROR;
	/* 8 data bits, 1 stop bit (2 if odd or 110 baud rate) */
	outpp(4, ((nbaud&1)||nbaud)==110? EN2STOP+X16CLOCK:EN1STOP+X16CLOCK);
	outpp(1, 0);
	outpp(3, RX8BITS);
	outpp(5, DTR+TX8BITS);
	outpp(10,NRZ);	/* nrz etc */
	outpp(11, TXCFBRGEN+RXCFBRGEN);	/* select clocking sources internal */

	bcmd= BMAGIC;
	bcmd /= nbaud;		/* this must be done unsigned! */

	outpp(12, bcmd);
	outpp(13, (bcmd>>8));
	outpp(14, BRGENPCLK+ENDTR+SETSRCBR);	/* Zilog sez do this twice */
	outpp(14, BRGENPCLK+ENDTR+SETSRCBR);	/* Zilog sez do this twice */
	Baudrate=nbaud;
/*
	printf("bcmd=%d bcmdms=0%o bcmdls=0%o\n",bcmd,(bcmd>>8),(bcmd&0377));
*/
	outpp(3, ENRX+RX8BITS);
	/* turn on dtr, also rts if baudrate is 1100 or more */
	outpp(5, nbaud >= 1100 ? DTR+TX8BITS+ENTX+RTS : DTR+TX8BITS+ENTX);
	outpp(14, ENBRGEN+BRGENPCLK+ENDTR+SETSRCBR);
	outpp(15,0);
	return OK;
}

/* fetch the baudrate from the modem port */
readbaud()
{
	unsigned div;

	div= inpp(12) | (inpp(13)<<8);	/* fetch divisor */
	if (div == 0) {
		Baudrate=300;		/* default if no baud rate in reg */
	} else {
		Baudrate=BMAGIC;	/* all this must be unsigned! */
		Baudrate /= div;
	}
}

/* Bye hangs up the line and then resets for another call */
bye()
{
	onhook();
	sleep(20*CLKMHZ);
	setbaud(Baudrate);
}

/* onhook goes off line for good */
onhook()
{
	outpp(5, 0);
}
sendbrk()
{
	outpp(5, SENDBRK);	/* set line to spacing */
	sleep(CLKMHZ);
	setbaud(Baudrate);	/* then restore it */
}


/*
 * Readline from MODEM13.C rewritten to allow much higher
 * baud rates.
 * Timeout is in deciseconds (1/10th's)
 * For top speed, character ready is checked in many places.
 * returns TIMEOUT if kbd character is ready.
 *
 */

readline(decisecs)
{
	if(MIREADY) {
		if(MIERROR)
			goto fubar;
		else
			return MICHAR;
	}
	while(--decisecs>=0) {
		if(MIREADY) {
			if(MIERROR)
				goto fubar;
			else
				return MICHAR;
		}
#ifdef CDO
		if(CDO)
			return TIMEOUT;
#endif
		if(CIREADY) {
			CICHAR;		/* dismiss character */
			return TIMEOUT;
		}
		for(Timeout=T1pause; --Timeout; )
			if(MIREADY) {
				if(MIERROR)
					goto fubar;
				else
					return MICHAR;
			}
	}
	return TIMEOUT;
fubar:
	MICHAR;		/* throw the turkey away */
	MI_ERROR_RESET;
	return ERROR;
}


sendline(data)
char data;
{
	while(!MOREADY)
		;
	outp(MODATA, data);
}

purgeline()
{
	while ((inpp(1)&ALLSENT)==0)
		;
	while(MIREADY)
		MICHAR;
	MI_ERROR_RESET;
}

#ifdef PORTSELAD
#define AUTODIAL
dial(name)
char *name;
{
	char *s;
	if((s=cisubstr(name, "\tm"))) {
		chngport(atoi(s+2));
		printf("Port %u ", Dport);
	}
	if((s=cisubstr(name, "\tb")))
		if(!setbaud(atoi(s+2)))
			printf(" %u baud\n", Baudrate);
	printf("%s", name);
	return OK;
}
#endif

#ifdef MICROCOM
#define AUTODIAL
dial(name)
char *name;
{
	int count, dp3;
	char *s;
	unsigned tbaudd;

	printf("%s", name);
	if((s=cisubstr(name, "\tb")))
		tbaudd=atoi(s+2);
	else
		tbaudd=0;
	if((s=cisubstr(name, "\tm"))) {
		chngport(atoi(s+2));
		printf(" Port %u ", Dport);
	}
	else {
		if (tbaudd>450)
			tbaudd=300;
		setbaud(300);
		for(count=5; --count>=0; ) {
			purgeline();
			sendline(' ');
			if(readline(5) != 'C') {
				/* send long break to reset */
				printf("Reset..");
				outpp(5, SENDBRK);
				sleep(5 * CLKMHZ); setbaud(300);
				while(readline(8) != TIMEOUT)
					;
				while(readline(4) != TIMEOUT)
					;
				sendge(ESC); sendge(EOT);
				continue;
			}
			for(dp3=5; --dp3>=0; )
				if (sendge('D')=='D')
					break;
			/* skip to 1st digit of number */
			s=cisubstr(name, "\t");
			for (; *s && !isdigit(*s); ++s)
				;
			for ( ; *s > ' '; ++s) {
				if(isdigit(*s) || *s=='X')
					sendge(*s);	/* send no dashes */
			}
			sendline('\r');
			while ((dp3=readline(100)) != 'D' && dp3 != 'C')
				;
			if(dp3!='D') {
				printf("\nCall Failed:%c\n", dp3);
				return ERROR;
			}
			else
				break;
		}
	}
	if(tbaudd) {
		setbaud(tbaudd);
	}
	printf(" Connected at %u Baud\n", Baudrate);
	return OK;
}
/* send char to modem controller, wait for echo, display and return it. */
sendge(c)
{
	register b;
	sendline(c);
	putcty(b=readline(5));
	return b;
}
#endif


/* default "autodial" routine */
#ifndef AUTODIAL
dial(name)
char *name;
{
	char *s;
	if((s=cisubstr(name, "\tb")))
		if(!setbaud(atoi(s+2)))
			printf("Baudrate set to %u: ", Baudrate);
	printf("%s", name);
	return OK;
}
#endif

/*
 * change modem port to n
 */
chngport(n)
{
	Sport=(Dport=n)+(SPORT-DPORT);
	readbaud();
}
/*
 * Special i/o routines for Z8530 SCC with pointer register
 *
 *  outpp(p, c) outputs c to subport p of chip selected by Sport
 *  inpp(p) returns value in subport p of chip slected by Sport
 */
outpp(p, c)
{
	outp(Sport, p); outp(Sport, c);
}
inpp(p)
{
	outp(Sport, p); return inp(Sport);
}