#include	"u.h"#include	"../port/lib.h"#include	"mem.h"#include	"dat.h"#include	"fns.h"#include	"io.h"#include	"../port/error.h" /* Centronix parallel (printer) port */ /* base addresses */static int lptbase[] = {	0x3bc,	/* lpt1 */	0x378,	/* lpt2 (sic) */	0x278	/* lpt3 (sic) */};#define NDEV	(sizeof lptbase/sizeof lptbase[0]) /* offsets, and bits in the registers */enum{	/* data latch register */	Qdlr=		0x0,	/* printer status register */	Qpsr=		0x1,	Fnotbusy=	0x80,	Fack=		0x40,	Fpe=		0x20,	Fselect=	0x10,	Fnoerror=	0x08,	/* printer control register */	Qpcr=		0x2,	Fie=		0x10,	Fselectin=	0x08,	Finitbar=	0x04,	Faf=		0x02,	Fstrobe=	0x01,	/* fake `data register' */	Qdata=		0x3,}; static int	lptready(void*);static void	outch(int, int);static void	lptintr(Ureg*, void*); static Rendez	lptrendez; Dirtab lptdir[]={	"dlr",		{Qdlr},		1,		0666,	"psr",		{Qpsr},		5,		0444,	"pcr",		{Qpcr},		0,		0222,	"data",		{Qdata},	0,		0222,};#define NLPT	(sizeof lptdir/sizeof lptdir[0]) static intlptgen(Chan *c, Dirtab *tab, int ntab, int i, Dir *dp){	Qid qid;	char name[NAMELEN]; 	if(tab==0 || i>=ntab)		return -1;	tab += i;	qid = tab->qid;	if(qid.path < Qdata)		qid.path += lptbase[c->dev];	qid.vers = c->dev;	sprint(name, "lpt%d%s", c->dev+1, tab->name);	devdir(c, qid, name, tab->length, eve, tab->perm, dp);	return 1;} voidlptreset(void){} voidlptinit(void){} Chan*lptattach(char *spec){	Chan *c;	int i  = (spec && *spec) ? strtol(spec, 0, 0) : 1;	static int set; 	if(!set){		set = 1;		setvec(Parallelvec, lptintr, 0);	}	if(i < 1 || i > NDEV)		error(Ebadarg);	c = devattach('L', spec);	c->dev = i-1;	return c;} Chan*lptclone(Chan *c, Chan *nc){	return devclone(c, nc);} intlptwalk(Chan *c, char *name){	return devwalk(c, name, lptdir, NLPT, lptgen);} voidlptstat(Chan *c, char *dp){	devstat(c, dp, lptdir, NLPT, lptgen);} Chan*lptopen(Chan *c, int omode){	return devopen(c, omode, lptdir, NLPT, lptgen);} voidlptcreate(Chan *c, char *name, int omode, ulong perm){	USED(c, name, omode, perm);	error(Eperm);} voidlptclose(Chan *c){	USED(c);} voidlptremove(Chan *c){	USED(c);	error(Eperm);} voidlptwstat(Chan *c, char *dp){	USED(c, dp);	error(Eperm);} longlptread(Chan *c, void *a, long n){	char str[16]; int size; 	if(c->qid.path == CHDIR)		return devdirread(c, a, n, lptdir, NLPT, lptgen);	size = sprint(str, "0x%2.2ux\n", inb(c->qid.path));	if(c->offset >= size)		return 0;	if(c->offset+n > size)		n = size-c->offset;	memmove(a, str+c->offset, n);	return n;} longlptwrite(Chan *c, void *a, long n){	char str[16], *p;	long base, k; 	if(n <= 0)		return 0;	if(c->qid.path != Qdata){		if(n > sizeof str-1)			n = sizeof str-1;		memmove(str, a, n);		str[n] = 0;		outb(c->qid.path, strtoul(str, 0, 0));		return n;	}	p = a;	k = n;	base = lptbase[c->dev];	if(waserror()){		outb(base+Qpcr, Finitbar);		nexterror();	}	while(--k >= 0)		outch(base, *p++);	poperror();	return n;} static voidoutch(int base, int c){	int status, tries; 	for(tries = 0;; tries++){		status = inb(base+Qpsr);		if(!(status & Fselect) || !(status & Fnoerror))			error(Eio);		if(status & Fnotbusy)			break;		if(tries > 1000){			outb(base+Qpcr, Finitbar|Fie);			tsleep(&lptrendez, lptready, (void *)base, MS2HZ);		}	}	outb(base+Qdlr, c);	outb(base+Qpcr, Finitbar|Fstrobe);	outb(base+Qpcr, Finitbar);} static intlptready(void *base){	return inb((int)base+Qpsr)&Fnotbusy;} static voidlptintr(Ureg *ur, void *a){	USED(ur, a);	wakeup(&lptrendez);}