lpt.c

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	/* check if we can use interrupt */
	lprintf("oldirq %x\n", sc->sc_irq);
	if (isdp->id_irq) {
		sc->sc_irq = LP_HAS_IRQ | LP_USE_IRQ | LP_ENABLE_IRQ;
		printf("lpt%d: Interrupt-driven port\n", unit);
#ifdef INET
		lpattach(sc, unit);
#endif
	} else {
		sc->sc_irq = 0;
		lprintf("lpt%d: Polled port\n", unit);
	}
	lprintf("irq %x\n", sc->sc_irq);

	kdc_lpt[unit].kdc_state = DC_IDLE;

#ifdef DEVFS
/* XXX */ /* what to do about the flags in the minor number? */
	sprintf(name,"lpt%d",unit);
			/*	path name devsw minor type  uid gid perm*/
	sc->devfs_token = devfs_add_devsw( "/", name, &lpt_cdevsw, unit,
					DV_CHR, 0, 0, 0600);
#endif
	return (1);
}

/*
 * lptopen -- reset the printer, then wait until it's selected and not busy.
 *	If LP_BYPASS flag is selected, then we do not try to select the
 *	printer -- this is just used for passing ioctls.
 */

int
lptopen (dev_t dev, int flags, int fmt, struct proc *p)
{
	struct lpt_softc *sc;
	int s;
	int trys, port;
	u_int unit = LPTUNIT(minor(dev));

	sc = lpt_sc + unit;
	if ((unit >= NLPT) || (sc->sc_port == 0))
		return (ENXIO);

#ifdef INET
	if (sc->sc_if.if_flags & IFF_UP)
		return(EBUSY);
#endif

	if (sc->sc_state) {
		lprintf("lp: still open %x\n", sc->sc_state);
		return(EBUSY);
	} else
		sc->sc_state |= INIT;

	sc->sc_flags = LPTFLAGS(minor(dev));

	/* Check for open with BYPASS flag set. */
	if (sc->sc_flags & LP_BYPASS) {
		sc->sc_state = OPEN;
		return(0);
	}

	s = spltty();
	lprintf("lp flags 0x%x\n", sc->sc_flags);
	port = sc->sc_port;

	/* set IRQ status according to ENABLE_IRQ flag */
	if (sc->sc_irq & LP_ENABLE_IRQ)
		sc->sc_irq |= LP_USE_IRQ;
	else
		sc->sc_irq &= ~LP_USE_IRQ;

	/* init printer */
	if ((sc->sc_flags & LP_NO_PRIME) == 0) {
		if((sc->sc_flags & LP_PRIMEOPEN) || sc->sc_primed == 0) {
			outb(port+lpt_control, 0);
			sc->sc_primed++;
			DELAY(500);
		}
	}

	outb (port+lpt_control, LPC_SEL|LPC_NINIT);

	/* wait till ready (printer running diagnostics) */
	trys = 0;
	do {
		/* ran out of waiting for the printer */
		if (trys++ >= LPINITRDY*4) {
			splx(s);
			sc->sc_state = 0;
			lprintf ("status %x\n", inb(port+lpt_status) );
			return (EBUSY);
		}

		/* wait 1/4 second, give up if we get a signal */
		if (tsleep ((caddr_t)sc, LPPRI|PCATCH, "lptinit", hz/4) !=
		    EWOULDBLOCK) {
			sc->sc_state = 0;
			splx(s);
			return (EBUSY);
		}

		/* is printer online and ready for output */
	} while ((inb(port+lpt_status) & (LPS_SEL|LPS_OUT|LPS_NBSY|LPS_NERR)) !=
		 (LPS_SEL|LPS_NBSY|LPS_NERR));

	sc->sc_control = LPC_SEL|LPC_NINIT;
	if (sc->sc_flags & LP_AUTOLF)
		sc->sc_control |= LPC_AUTOL;

	/* enable interrupt if interrupt-driven */
	if (sc->sc_irq & LP_USE_IRQ)
		sc->sc_control |= LPC_ENA;

	outb(port+lpt_control, sc->sc_control);

	sc->sc_state = OPEN;
	kdc_lpt[unit].kdc_state = DC_BUSY;
	sc->sc_inbuf = geteblk(BUFSIZE);
	sc->sc_xfercnt = 0;
	splx(s);

	/* only use timeout if using interrupt */
	lprintf("irq %x\n", sc->sc_irq);
	if (sc->sc_irq & LP_USE_IRQ) {
		sc->sc_state |= TOUT;
		timeout ((timeout_func_t)lptout, (caddr_t)sc,
			 (sc->sc_backoff = hz/LPTOUTINITIAL));
	}

	lprintf("opened.\n");
	return(0);
}

static void
lptout (struct lpt_softc * sc)
{	int pl;

	lprintf ("T %x ", inb(sc->sc_port+lpt_status));
	if (sc->sc_state & OPEN) {
		sc->sc_backoff++;
		if (sc->sc_backoff > hz/LPTOUTMAX)
			sc->sc_backoff = sc->sc_backoff > hz/LPTOUTMAX;
		timeout ((timeout_func_t)lptout, (caddr_t)sc, sc->sc_backoff);
	} else
		sc->sc_state &= ~TOUT;

	if (sc->sc_state & ERROR)
		sc->sc_state &= ~ERROR;

	/*
	 * Avoid possible hangs do to missed interrupts
	 */
	if (sc->sc_xfercnt) {
		pl = spltty();
		lptintr(sc - lpt_sc);
		splx(pl);
	} else {
		sc->sc_state &= ~OBUSY;
		wakeup((caddr_t)sc);
	}
}

/*
 * lptclose -- close the device, free the local line buffer.
 *
 * Check for interrupted write call added.
 */

int
lptclose(dev_t dev, int flags, int fmt, struct proc *p)
{
	struct lpt_softc *sc = lpt_sc + LPTUNIT(minor(dev));
	int port = sc->sc_port;

	if(sc->sc_flags & LP_BYPASS)
		goto end_close;

	sc->sc_state &= ~OPEN;
	kdc_lpt[minor(dev)].kdc_state = DC_IDLE;

	/* if the last write was interrupted, don't complete it */
	if((!(sc->sc_state  & INTERRUPTED)) && (sc->sc_irq & LP_USE_IRQ))
		while ((inb(port+lpt_status) & (LPS_SEL|LPS_OUT|LPS_NBSY|LPS_NERR)) !=
			(LPS_SEL|LPS_NBSY|LPS_NERR) || sc->sc_xfercnt)
			/* wait 1/4 second, give up if we get a signal */
			if (tsleep ((caddr_t)sc, LPPRI|PCATCH,
				"lpclose", hz) != EWOULDBLOCK)
				break;

	outb(sc->sc_port+lpt_control, LPC_NINIT);
	brelse(sc->sc_inbuf);

end_close:
	sc->sc_state = 0;
	sc->sc_xfercnt = 0;
	lprintf("closed.\n");
	return(0);
}

/*
 * pushbytes()
 *	Workhorse for actually spinning and writing bytes to printer
 *	Derived from lpa.c
 *	Originally by ?
 *
 *	This code is only used when we are polling the port
 */
static int
pushbytes(struct lpt_softc * sc)
{
	int spin, err, tic;
	char ch;
	int port = sc->sc_port;

	lprintf("p");
	/* loop for every character .. */
	while (sc->sc_xfercnt > 0) {
		/* printer data */
		ch = *(sc->sc_cp);
		sc->sc_cp++;
		sc->sc_xfercnt--;

		/*
		 * Wait for printer ready.
		 * Loop 20 usecs testing BUSY bit, then sleep
		 * for exponentially increasing timeout. (vak)
		 */
		for (spin=0; NOT_READY(port+lpt_status) && spin<MAX_SPIN; ++spin)
			DELAY(1);	/* XXX delay is NOT this accurate! */
		if (spin >= MAX_SPIN) {
			tic = 0;
			while (NOT_READY(port+lpt_status)) {
				/*
				 * Now sleep, every cycle a
				 * little longer ..
				 */
				tic = tic + tic + 1;
				/*
				 * But no more than 10 seconds. (vak)
				 */
				if (tic > MAX_SLEEP)
					tic = MAX_SLEEP;
				err = tsleep((caddr_t)sc, LPPRI,
					"lptpoll", tic);
				if (err != EWOULDBLOCK) {
					return (err);
				}
			}
		}

		/* output data */
		outb(port+lpt_data, ch);
		/* strobe */
		outb(port+lpt_control, sc->sc_control|LPC_STB);
		outb(port+lpt_control, sc->sc_control);

	}
	return(0);
}

/*
 * lptwrite --copy a line from user space to a local buffer, then call
 * putc to get the chars moved to the output queue.
 *
 * Flagging of interrupted write added.
 */

int
lptwrite(dev_t dev, struct uio * uio, int ioflag)
{
	register unsigned n;
	int pl, err;
	struct lpt_softc *sc = lpt_sc + LPTUNIT(minor(dev));

	if(sc->sc_flags & LP_BYPASS) {
		/* we can't do writes in bypass mode */
		return(EPERM);
	}

	sc->sc_state &= ~INTERRUPTED;
	while ((n = min(BUFSIZE, uio->uio_resid)) != 0) {
		sc->sc_cp = sc->sc_inbuf->b_un.b_addr ;
		uiomove(sc->sc_cp, n, uio);
		sc->sc_xfercnt = n ;
		while ((sc->sc_xfercnt > 0)&&(sc->sc_irq & LP_USE_IRQ)) {
			lprintf("i");
			/* if the printer is ready for a char, */
			/* give it one */
			if ((sc->sc_state & OBUSY) == 0){
				lprintf("\nC %d. ", sc->sc_xfercnt);
				pl = spltty();
				lptintr(sc - lpt_sc);
				(void) splx(pl);
			}
			lprintf("W ");
			if (sc->sc_state & OBUSY)
				if ((err = tsleep ((caddr_t)sc,
					 LPPRI|PCATCH, "lpwrite", 0))) {
					sc->sc_state |= INTERRUPTED;
					return(err);
				}
		}
		/* check to see if we must do a polled write */
		if(!(sc->sc_irq & LP_USE_IRQ) && (sc->sc_xfercnt)) {
			lprintf("p");
			if((err = pushbytes(sc)))
				return(err);
		}
	}
	return(0);
}

/*
 * lptintr -- handle printer interrupts which occur when the printer is
 * ready to accept another char.
 *
 * do checking for interrupted write call.
 */

void
lptintr(int unit)
{
	struct lpt_softc *sc = lpt_sc + unit;
	int port = sc->sc_port, sts;
	int i;

#ifdef INET
	if(sc->sc_if.if_flags & IFF_UP) {
	    lpintr(unit);
	    return;
	}
#endif /* INET */

	/*
	 * Is printer online and ready for output?
	 *
	 * Avoid falling back to lptout() too quickly.  First spin-loop
	 * to see if the printer will become ready ``really soon now''.
	 */
	for (i = 0;
	     i < 100 &&
	     ((sts=inb(port+lpt_status)) & RDY_MASK) != LP_READY;
	     i++) ;
	if ((sts & RDY_MASK) == LP_READY) {
		sc->sc_state = (sc->sc_state | OBUSY) & ~ERROR;
		sc->sc_backoff = hz/LPTOUTINITIAL;

		if (sc->sc_xfercnt) {
			/* send char */
			/*lprintf("%x ", *sc->sc_cp); */
			outb(port+lpt_data, *sc->sc_cp++) ;
			outb(port+lpt_control, sc->sc_control|LPC_STB);
			/* DELAY(X) */
			outb(port+lpt_control, sc->sc_control);

			/* any more data for printer */
			if(--(sc->sc_xfercnt) > 0) return;
		}

		/*
		 * No more data waiting for printer.
		 * Wakeup is not done if write call was interrupted.
		 */
		sc->sc_state &= ~OBUSY;
		if(!(sc->sc_state & INTERRUPTED))
			wakeup((caddr_t)sc);
		lprintf("w ");
		return;
	} else	{	/* check for error */
		if(((sts & (LPS_NERR | LPS_OUT) ) != LPS_NERR) &&
				(sc->sc_state & OPEN))
			sc->sc_state |= ERROR;
		/* lptout() will jump in and try to restart. */
	}
	lprintf("sts %x ", sts);
}

int
lptioctl(dev_t dev, int cmd, caddr_t data, int flags, struct proc *p)
{
	int	error = 0;
        struct	lpt_softc *sc;
        u_int	unit = LPTUNIT(minor(dev));
	u_char	old_sc_irq;	/* old printer IRQ status */

        sc = lpt_sc + unit;

	switch (cmd) {
	case LPT_IRQ :
		if(sc->sc_irq & LP_HAS_IRQ) {
			/*
			 * NOTE:
			 * If the IRQ status is changed,
			 * this will only be visible on the
			 * next open.
			 *
			 * If interrupt status changes,
			 * this gets syslog'd.
			 */
			old_sc_irq = sc->sc_irq;
			if(*(int*)data == 0)
				sc->sc_irq &= (~LP_ENABLE_IRQ);
			else
				sc->sc_irq |= LP_ENABLE_IRQ;
			if (old_sc_irq != sc->sc_irq )
				log(LOG_NOTICE, "lpt%c switched to %s mode\n",
					(char)unit+'0',
					(sc->sc_irq & LP_ENABLE_IRQ)?
					"interrupt-driven":"polled");
		} else /* polled port */
			error = EOPNOTSUPP;
		break;
	default:
		error = ENODEV;
	}

	return(error);
}

#ifdef INET

static void
lpattach (struct lpt_softc *sc, int unit)
{
	struct ifnet *ifp = &sc->sc_if;

	ifp->if_name = "lp";
	ifp->if_unit = unit;
	ifp->if_mtu = LPMTU;
	ifp->if_flags = IFF_SIMPLEX | IFF_POINTOPOINT | IFF_MULTICAST;
	ifp->if_ioctl = lpioctl;
	ifp->if_output = lpoutput;
	ifp->if_type = IFT_PARA;
	ifp->if_hdrlen = 0;
	ifp->if_addrlen = 0;
	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
	if_attach(ifp);
	printf("lp%d: TCP/IP capable interface\n", unit);

#if NBPFILTER > 0
	bpfattach(&ifp->if_bpf, ifp, DLT_NULL, LPIPHDRLEN);
#endif
}
/*
 * Build the translation tables for the LPIP (BSD unix) protocol.
 * We don't want to calculate these nasties in our tight loop, so we
 * precalculate them when we initialize.
 */
static int
lpinittables (void)
{
    int i;

    if (!txmith)
	txmith = malloc(4*LPIPTBLSIZE, M_DEVBUF, M_NOWAIT);

    if (!txmith)
	return 1;

    if (!ctxmith)
	ctxmith = malloc(4*LPIPTBLSIZE, M_DEVBUF, M_NOWAIT);

    if (!ctxmith)