/* * DU-11 Synchronous interface driver */#include "../h/param.h"#include "../h/systm.h"#include "../h/dir.h"#include "../h/user.h"#include "../h/buf.h"/* device registers */struct dureg {	int	rxcsr, rxdbuf;#define	parcsr	rxdbuf	int	txcsr, txdbuf;};struct du {	struct dureg	*du_addr;	int		du_state;	struct proc	*du_proc;	struct buf	*du_buf;	caddr_t		du_bufb;	caddr_t		du_bufp;	int		du_nxmit;	int		du_timer;} du[] = {	{ (struct dureg *) 0160110 },};#define	NDU	(sizeof(du)/sizeof(du[0]))#define	DONE	0200#define	IE	0100#define	SIE	040#define CTS	020000#define	CARRIER	010000#define	RCVACT	04000#define	DSR	01000#define STRIP	0400#define SCH	020#define RTS	04#define	DTR	02#define MR	0400#define SEND	020#define	HALF	010#define	READ	0#define	WRITE	1#define PWRIT	2#define	DUPRI	(PZERO+1)duopen(dev)register dev;{	int dutimeout();	register struct du *dp;	register struct dureg *lp;	dev = minor(dev);	if (dev >= NDU ||	   ((dp = &du[dev])->du_proc!=NULL && dp->du_proc!=u.u_procp)) {		u.u_error = ENXIO;		return;	}	dp->du_proc = u.u_procp;	lp = dp->du_addr;	if (dp->du_buf==NULL) {		dp->du_buf = geteblk();		dp->du_bufb = dp->du_buf->b_un.b_addr;		dp->du_state = WRITE;		lp->txcsr = MR;		lp->parcsr = 035026;		/* Sync Int, 7 bits, even parity, sync=026 */		timeout(dutimeout, (caddr_t)dp, HZ);		duturn(dp);	}}duclose(dev){	register struct du *dp;	register struct dureg *lp;	dp = &du[minor(dev)];	lp = dp->du_addr;	lp->rxcsr = 0;	lp->txcsr = 0;	dp->du_timer = 0;	dp->du_proc = 0;	if (dp->du_buf != NULL) {		brelse(dp->du_buf);		dp->du_buf = NULL;	}}duread(dev){	register char *bp;	register struct du *dp;	dp = &du[minor(dev)];	bp = dp->du_bufb;	for(;;) {		if(duwait(dev))			return;		if (dp->du_bufp > bp)			break;		spl6();		if (dp->du_timer <= 1) {			spl0();			return;		}		sleep((caddr_t)dp, DUPRI);		spl0();	}	u.u_offset = 0;	iomove(dp->du_bufb, (int)min(u.u_count, (unsigned)(dp->du_bufp-bp)), B_READ);}duwrite(dev){	register struct du *dp;	register struct dureg *lp;	dev = minor(dev);	dp = &du[dev];	if (u.u_count==0 || duwait(dev))		return;	dp->du_bufp = dp->du_bufb;	dp->du_state = PWRIT;	dp->du_addr->rxcsr &= ~SCH;	dp->du_addr->rxcsr = SIE|RTS|DTR;	if (u.u_count > BSIZE)		u.u_count = BSIZE;	dp->du_nxmit = u.u_count;	u.u_offset = 0;	iomove(dp->du_bufb, (int)u.u_count, B_WRITE);	lp = dp->du_addr;	dp->du_timer = 10;	spl6();	while((lp->rxcsr&CTS)==0)		sleep((caddr_t)dp, DUPRI);	if (dp->du_state != WRITE) {		dp->du_state = WRITE;		lp->txcsr = IE|SIE|SEND|HALF;		dustart(dev);	}	spl0();}duwait(dev){	register struct du *dp;	register struct dureg *lp;	dp = &du[minor(dev)];	lp = dp->du_addr;	for(;;) {		if ((lp->rxcsr&DSR)==0 || dp->du_buf==0) {			u.u_error = EIO;			return(1);		}		spl6();		if (dp->du_state==READ &&			((lp->rxcsr&RCVACT)==0)) {			spl0();			return(0);		}		sleep((caddr_t)dp, DUPRI);		spl0();	}}dustart(dev){	register struct du *dp;	register struct dureg *lp;	dp = &du[minor(dev)];	lp = dp->du_addr;	dp->du_timer = 10;	if (dp->du_nxmit > 0) {		dp->du_nxmit--;		lp->txdbuf = *dp->du_bufp++;	} else {		duturn(dp);	}}durint(dev){	register struct du *dp;	register c, s;	int dustat;	dp = &du[minor(dev)];	dustat = dp->du_addr->rxcsr;	if(dustat<0) {		if((dustat&CARRIER)==0 && dp->du_state==READ)			duturn(dp);		else			wakeup((caddr_t)dp);	} else	if(dustat&DONE) {		dp->du_addr->rxcsr = IE|SIE|SCH|DTR;		c = s = dp->du_addr->rxdbuf;		c &= 0177;		if(s<0)			c |= 0200;		if (dp->du_bufp < dp->du_bufb+BSIZE)			*dp->du_bufp++ = c;	}}duxint(dev){	register struct du *dp;	register struct dureg *lp;	register int dustat;	dp = &du[minor(dev)];	lp = dp->du_addr;	dustat = lp->txcsr;	if(dustat<0)		duturn(dp);	else if(dustat&DONE)		dustart(dev);}duturn(dp)register struct du *dp;{	register struct dureg *lp;	lp = dp->du_addr;	if (dp->du_state!=READ) {		dp->du_state = READ;		dp->du_timer = 10;		dp->du_bufp = dp->du_bufb;	}	lp->txcsr = HALF;	lp->rxcsr &= ~SCH;	lp->rxcsr = STRIP|IE|SIE|SCH|DTR;	wakeup((caddr_t)dp);}dutimeout(dp)register struct du *dp;{	if (dp->du_timer == 0)		return;	if (--dp->du_timer == 0) {		duturn(dp);		dp->du_timer = 1;	}	timeout(dutimeout, (caddr_t)dp, HZ);}