initial import of NetBSD tree

1 files changed, 876 insertions, 0 deletions

diff --git a/sys/arch/pc532/dev/lpt.c b/sys/arch/pc532/dev/lpt.c
new file mode 100644
index 00000000000..9811279385f
--- /dev/null
+++ b/sys/arch/pc532/dev/lpt.c
@@ -0,0 +1,876 @@
+/*	$NetBSD: lpt.c,v 1.6 1995/09/26 20:16:06 phil Exp $	*/
+
+/*
+ * Copyright (c) 1994 Matthias Pfaller.
+ * Copyright (c) 1994 Poul-Henning Kamp
+ * Copyright (c) 1993, 1994 Charles Hannum.
+ * Copyright (c) 1990 William F. Jolitz, TeleMuse
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This software is a component of "386BSD" developed by 
+ *	William F. Jolitz, TeleMuse.
+ * 4. Neither the name of the developer nor the name "386BSD"
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS A COMPONENT OF 386BSD DEVELOPED BY WILLIAM F. JOLITZ 
+ * AND IS INTENDED FOR RESEARCH AND EDUCATIONAL PURPOSES ONLY. THIS 
+ * SOFTWARE SHOULD NOT BE CONSIDERED TO BE A COMMERCIAL PRODUCT. 
+ * THE DEVELOPER URGES THAT USERS WHO REQUIRE A COMMERCIAL PRODUCT 
+ * NOT MAKE USE OF THIS WORK.
+ *
+ * FOR USERS WHO WISH TO UNDERSTAND THE 386BSD SYSTEM DEVELOPED
+ * BY WILLIAM F. JOLITZ, WE RECOMMEND THE USER STUDY WRITTEN 
+ * REFERENCES SUCH AS THE  "PORTING UNIX TO THE 386" SERIES 
+ * (BEGINNING JANUARY 1991 "DR. DOBBS JOURNAL", USA AND BEGINNING 
+ * JUNE 1991 "UNIX MAGAZIN", GERMANY) BY WILLIAM F. JOLITZ AND 
+ * LYNNE GREER JOLITZ, AS WELL AS OTHER BOOKS ON UNIX AND THE 
+ * ON-LINE 386BSD USER MANUAL BEFORE USE. A BOOK DISCUSSING THE INTERNALS 
+ * OF 386BSD ENTITLED "386BSD FROM THE INSIDE OUT" WILL BE AVAILABLE LATE 1992.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE DEVELOPER ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE DEVELOPER BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ */
+
+/*
+ * Device Driver for Matthias's parallel printer port.
+ * This driver is based on the i386 lpt driver and
+ * some IP code from Poul-Henning Kamp.
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/proc.h>
+#include <sys/user.h>
+#include <sys/buf.h>
+#include <sys/kernel.h>
+#include <sys/ioctl.h>
+#include <sys/uio.h>
+#include <sys/device.h>
+#include <sys/syslog.h>
+#include <sys/malloc.h>
+#include <machine/cpu.h>
+
+#include "lpt.h"
+#include "lptreg.h"
+
+#if defined(INET) && defined(PLIP)
+#include <sys/mbuf.h>
+#include <sys/socket.h>
+#include <net/if.h>
+#include <net/if_types.h>
+#include <net/netisr.h>
+#include <net/route.h>
+#include <netinet/in.h>
+#include <netinet/in_systm.h>
+#include <netinet/in_var.h>
+#include <netinet/ip.h>
+#include <netinet/if_ether.h>
+#endif
+
+#define	LPT_INVERT	(LPC_NBUSY|LPC_NERROR|LPC_NACK|LPC_ONLINE)
+#define	LPT_MASK	(LPC_NBUSY|LPC_NERROR|LPC_NACK|LPC_NOPAPER|LPC_ONLINE)
+
+#define	TIMEOUT		hz*16	/* wait up to 16 seconds for a ready */
+#define	STEP		hz/4
+
+#define	LPTPRI		(PZERO+8)
+#define	LPT_BSIZE	1024
+
+#if defined(INET) && defined(PLIP)
+#ifndef PLIPMTU			/* MTU for the plip# interfaces */
+#if defined(COMPAT_PLIP10)
+#define	PLIPMTU		1600
+#else
+#define	PLIPMTU		(ETHERMTU - ifp->if_hdrlen)
+#endif
+#endif
+
+#ifndef PLIPMXSPIN1		/* DELAY factor for the plip# interfaces */
+#define	PLIPMXSPIN1	2000	/* Spinning for remote intr to happen */
+#endif
+
+#ifndef PLIPMXSPIN2		/* DELAY factor for the plip# interfaces */
+#define	PLIPMXSPIN2	6000	/* Spinning for remote handshake to happen */
+#endif
+
+#ifndef PLIPMXERRS		/* Max errors before !RUNNING */
+#define	PLIPMXERRS	20
+#endif
+#ifndef PLIPMXRETRY
+#define PLIPMXRETRY	20	/* Max number of retransmits */
+#endif
+#ifndef PLIPRETRY
+#define PLIPRETRY	hz/50	/* Time between retransmits */
+#endif
+#endif
+
+struct lpt_softc {
+	struct device sc_dev;
+	size_t sc_count;
+	u_char *sc_inbuf;
+	u_char *sc_cp;
+	volatile struct i8255 *sc_i8255;
+	int sc_irq;
+	u_char sc_state;
+#define	LPT_OPEN	0x01	/* device is open */
+#define	LPT_INIT	0x02	/* waiting to initialize for open */
+
+	u_char sc_status;
+	u_char sc_flags;
+#define	LPT_AUTOLF	0x20	/* automatic LF on CR */
+#define	LPT_NOPRIME	0x40	/* don't prime on open */
+
+#if defined(INET) && defined(PLIP)
+	struct	arpcom	sc_arpcom;
+	u_char		*sc_ifbuf;
+	int		sc_ifierrs;	/* consecutive input errors */
+	int		sc_ifoerrs;	/* consecutive output errors */
+	int		sc_ifsoftint;	/* i/o software interrupt */
+	volatile int	sc_pending;	/* interrputs pending */
+#define PLIP_IPENDING	1
+#define PLIP_OPENDING	2
+
+#if defined(COMPAT_PLIP10)
+	u_char		sc_adrcksum;
+#endif
+#endif
+};
+
+#define	LPTUNIT(s)	(minor(s) & 0x1f)
+#define	LPTFLAGS(s)	(minor(s) & 0xe0)
+
+static int lptmatch(struct device *, void *, void *aux);
+static void lptattach(struct device *, struct device *, void *);
+static void lptintr(struct lpt_softc *);
+static int notready(u_char, struct lpt_softc *);
+static void lptout(void *arg);
+static int pushbytes(struct lpt_softc *);
+
+#if defined(INET) && defined(PLIP)
+/* Functions for the plip# interface */
+static void plipattach(struct lpt_softc *,int);
+static int plipioctl(struct ifnet *, u_long, caddr_t);
+static void plipsoftint(struct lpt_softc *);
+static void plipinput(struct lpt_softc *);
+static void plipstart(struct ifnet *);
+static void plipoutput(struct lpt_softc *);
+#endif
+
+struct cfdriver lptcd = {
+	NULL,
+	"lpt",
+	lptmatch,
+	lptattach,
+	DV_TTY,
+	sizeof(struct lpt_softc),
+	NULL,
+	0
+};
+
+lptmatch(struct device *parent, void *cf, void *aux)
+{
+	volatile struct i8255 *i8255 =
+		(volatile struct i8255 *)((struct cfdata *)cf)->cf_loc[0];
+	int unit = ((struct cfdata *)cf)->cf_unit;
+
+	if (unit >= LPT_MAX)
+		return(0);
+
+	if ((int) i8255 == -1)
+		i8255 = LPT_ADR(unit);
+
+	i8255->port_control = LPT_PROBE_MODE;
+
+	i8255->port_control = LPT_PROBE_CLR;
+	if ((i8255->port_c & LPT_PROBE_MASK) != 0)
+		return 0;
+	
+	i8255->port_control = LPT_PROBE_SET;
+	if ((i8255->port_c & LPT_PROBE_MASK) == 0)
+		return 0;
+
+	i8255->port_control = LPT_PROBE_CLR;
+	if ((i8255->port_c & LPT_PROBE_MASK) != 0)
+		return 0;
+
+	i8255->port_control = LPT_MODE;
+	i8255->port_a = LPA_ACTIVE | LPA_NPRIME;
+	
+	return 1;
+}
+
+void
+lptattach(struct device *parent, struct device *self, void *aux)
+{
+	struct lpt_softc *sc = (struct lpt_softc *) self;
+	volatile struct i8255 *i8255 =
+			(volatile struct i8255 *)self->dv_cfdata->cf_loc[0];
+
+	if ((sc->sc_irq = self->dv_cfdata->cf_loc[1]) == -1)
+		sc->sc_irq = LPT_IRQ(self->dv_unit);
+
+	if ((int)i8255 == -1)
+		i8255 = LPT_ADR(self->dv_unit);
+	i8255->port_control = LPT_MODE;
+	i8255->port_a = LPA_ACTIVE | LPA_NPRIME;
+	i8255->port_control = LPT_IRQDISABLE;
+
+	sc->sc_state = 0;
+	sc->sc_i8255 = i8255;
+
+#if defined(INET) && defined(PLIP)
+	plipattach(sc, self->dv_unit);
+#endif
+	intr_establish(sc->sc_irq, lptintr, sc, sc->sc_dev.dv_xname,
+			IPL_NONE, FALLING_EDGE);
+	printf(" addr 0x%x, irq %d\n", (int) i8255, sc->sc_irq);
+}
+
+/*
+ * Reset the printer, then wait until it's selected and not busy.
+ */
+int
+lptopen(dev_t dev, int flag)
+{
+	struct lpt_softc *sc = (struct lpt_softc *) lptcd.cd_devs[LPTUNIT(dev)];
+	volatile struct i8255 *i8255 = sc->sc_i8255;
+	u_char flags = LPTFLAGS(dev);
+	int error;
+	int spin;
+
+	if (LPTUNIT(dev) >= NLPT || !sc)
+		return ENXIO;
+
+	if (sc->sc_state)
+		return EBUSY;
+
+#if defined(INET) && defined(PLIP)
+	if (sc->sc_arpcom.ac_if.if_flags & IFF_UP)
+		return EBUSY;
+#endif
+
+	sc->sc_state = LPT_INIT;
+	sc->sc_flags = flags;
+
+	if ((flags & LPT_NOPRIME) == 0) {
+		/* assert INIT for 100 usec to start up printer */
+		i8255->port_a &= ~LPA_NPRIME;
+		DELAY(100);
+	}
+
+	if (flags & LPT_AUTOLF)
+		i8255->port_a |= LPA_ALF | LPA_SELECT | LPA_NPRIME;
+	else
+		i8255->port_a = (i8255->port_a & ~LPA_ALF)
+				| LPA_SELECT | LPA_NPRIME;
+
+	/* wait till ready (printer running diagnostics) */
+	for (spin = 0; notready(i8255->port_c, sc); spin += STEP) {
+		if (spin >= TIMEOUT) {
+			sc->sc_state = 0;
+			return EBUSY;
+		}
+
+		/* wait 1/4 second, give up if we get a signal */
+		if (error = tsleep((caddr_t)sc, LPTPRI | PCATCH, "lptopen",
+		    STEP) != EWOULDBLOCK) {
+			sc->sc_state = 0;
+			return error;
+		}
+	}
+
+	sc->sc_inbuf  = malloc(LPT_BSIZE, M_DEVBUF, M_WAITOK);
+	sc->sc_status =
+	sc->sc_count  = 0;
+	sc->sc_state  = LPT_OPEN;
+
+	return 0;
+}
+
+int
+notready(u_char status, struct lpt_softc *sc)
+{
+	status ^= LPT_INVERT;
+
+	if (status != sc->sc_status) {
+		if (status & LPC_NOPAPER)
+			log(LOG_NOTICE, "%s: out of paper\n", sc->sc_dev.dv_xname);
+		if (status & LPC_ONLINE)
+			log(LOG_NOTICE, "%s: offline\n", sc->sc_dev.dv_xname);
+		if (status & LPC_NERROR)
+			log(LOG_NOTICE, "%s: output error\n", sc->sc_dev.dv_xname);
+		if (status & LPC_NACK)
+			log(LOG_NOTICE, "%s: NACK low\n", sc->sc_dev.dv_xname);
+		if (status & LPC_NBUSY)
+			log(LOG_NOTICE, "%s: NBUSY low\n", sc->sc_dev.dv_xname);
+		sc->sc_status = status;
+	}
+	return status & LPT_MASK;
+}
+
+void
+lptout(void *arg)
+{
+	struct lpt_softc *sc = (struct lpt_softc *) arg;
+	if (sc->sc_count > 0)
+		sc->sc_i8255->port_control = LPT_IRQENABLE;
+}
+
+/*
+ * Close the device, and free the local line buffer.
+ */
+lptclose(dev_t dev, int flag)
+{
+	struct lpt_softc *sc = (struct lpt_softc *) lptcd.cd_devs[LPTUNIT(dev)];
+
+	if (sc->sc_count)
+		(void) pushbytes(sc);
+
+	sc->sc_i8255->port_control = LPT_IRQDISABLE;
+	sc->sc_state = 0;
+	free(sc->sc_inbuf, M_DEVBUF);
+
+	return 0;
+}
+
+int
+pushbytes(struct lpt_softc *sc)
+{
+	volatile struct i8255 *i8255 = sc->sc_i8255;
+	int error;
+
+	while (sc->sc_count > 0) {
+		i8255->port_control = LPT_IRQENABLE;
+		if (error = tsleep((caddr_t)sc, LPTPRI | PCATCH,
+		    "lptwrite", 0))
+			return error;
+	}
+	return 0;
+}
+
+/* 
+ * Copy a line from user space to a local buffer, then call pushbytes to
+ * get the chars moved to the output queue.
+ */
+lptwrite(dev_t dev, struct uio *uio)
+{
+	struct lpt_softc *sc = (struct lpt_softc *) lptcd.cd_devs[LPTUNIT(dev)];
+	size_t n;
+	int error = 0;
+
+	if (sc->sc_count) return EBUSY;
+	while (n = min(LPT_BSIZE, uio->uio_resid)) {
+		uiomove(sc->sc_cp = sc->sc_inbuf, n, uio);
+		sc->sc_count = n;
+		error = pushbytes(sc);
+		if (error) {
+			/*
+			 * Return accurate residual if interrupted or timed
+			 * out.
+			 */
+			uio->uio_resid += sc->sc_count;
+			sc->sc_count = 0;
+			return error;
+		}
+	}
+	return 0;
+}
+
+/*
+ * Handle printer interrupts which occur when the printer is ready to accept
+ * another char.
+ */
+void
+lptintr(struct lpt_softc *sc)
+{
+	volatile struct i8255 *i8255 = sc->sc_i8255;
+
+#if defined(INET) && defined(PLIP)
+	if(sc->sc_arpcom.ac_if.if_flags & IFF_UP) {
+		i8255->port_a &= ~LPA_ACKENABLE;
+		sc->sc_pending |= PLIP_IPENDING;
+		softintr(sc->sc_ifsoftint);
+		return;
+	}
+#endif
+
+	if ((sc->sc_state & LPT_OPEN) == 0) {
+		i8255->port_control = LPT_IRQDISABLE;
+		return;
+	}
+
+	if (sc->sc_count) {
+		/* is printer online and ready for output? */
+		if (notready(i8255->port_c, sc)) {
+			i8255->port_control = LPT_IRQDISABLE;
+			timeout(lptout, sc, STEP);
+			return;
+		}
+		/* send char */
+		i8255->port_a &= ~LPA_ACTIVE;
+		i8255->port_b = *sc->sc_cp++;
+		i8255->port_a |= LPA_ACTIVE;
+		sc->sc_count--;
+	}
+
+	if (sc->sc_count == 0) {
+		/* none, wake up the top half to get more */
+		i8255->port_control = LPT_IRQDISABLE;
+		wakeup((caddr_t)sc);
+	}
+}
+
+int
+lptioctl(dev_t dev, int cmd, caddr_t data, int flag)
+{
+	int error = 0;
+
+	switch (cmd) {
+	default:
+		error = EINVAL;
+	}
+
+	return error;
+}
+
+#if defined(INET) && defined(PLIP)
+
+static void
+plipattach(struct lpt_softc *sc, int unit)
+{
+	struct ifnet *ifp = &sc->sc_arpcom.ac_if;
+
+	sc->sc_ifbuf = NULL;
+	ifp->if_unit = unit;
+	ifp->if_name = "plip";
+	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_NOTRAILERS;
+	ifp->if_output = ether_output;
+	ifp->if_start = plipstart;
+	ifp->if_ioctl = plipioctl;
+	ifp->if_watchdog = 0;
+
+	ifp->if_type = IFT_ETHER;
+	ifp->if_addrlen = 6;
+	ifp->if_hdrlen = 14;
+	ifp->if_mtu = PLIPMTU;
+	sc->sc_ifsoftint = intr_establish(SOFTINT, plipsoftint, sc,
+					sc->sc_dev.dv_xname, IPL_NET, 0);
+
+	if_attach(ifp);
+}
+
+/*
+ * Process an ioctl request.
+ */
+static int
+plipioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
+{
+	struct proc *p = curproc;
+	struct lpt_softc *sc = (struct lpt_softc *) lptcd.cd_devs[ifp->if_unit];
+	volatile struct i8255 *i8255 = sc->sc_i8255;
+	struct ifaddr *ifa = (struct ifaddr *)data;
+	struct ifreq *ifr = (struct ifreq *)data; 
+	int s;
+	int error = 0;
+
+	switch (cmd) {
+
+	case SIOCSIFFLAGS:
+		if (((ifp->if_flags & IFF_UP) == 0) &&
+		    (ifp->if_flags & IFF_RUNNING)) {
+		        ifp->if_flags &= ~IFF_RUNNING;
+			sc->sc_i8255->port_control = LPT_MODE;
+			i8255->port_a = LPA_ACTIVE | LPA_NPRIME;
+			if (sc->sc_ifbuf)
+				free(sc->sc_ifbuf, M_DEVBUF);
+			sc->sc_ifbuf = NULL;
+		}
+		if (((ifp->if_flags & IFF_UP)) &&
+		    ((ifp->if_flags & IFF_RUNNING) == 0)) {
+			if (sc->sc_state) {
+				error = EBUSY;
+				break;
+			}
+			if (!sc->sc_ifbuf)
+				sc->sc_ifbuf =
+					malloc(ifp->if_mtu + ifp->if_hdrlen,
+					       M_DEVBUF, M_WAITOK);
+		        ifp->if_flags |= IFF_RUNNING;
+			sc->sc_i8255->port_control = LPT_IRQDISABLE;
+			sc->sc_i8255->port_b = 0;
+			sc->sc_i8255->port_a |= LPA_ACKENABLE;
+		}
+		break;
+
+	case SIOCSIFADDR:
+		if (ifa->ifa_addr->sa_family == AF_INET) {
+			if (!sc->sc_ifbuf)
+				sc->sc_ifbuf =
+					malloc(PLIPMTU + ifp->if_hdrlen,
+					       M_DEVBUF, M_WAITOK);
+			sc->sc_arpcom.ac_enaddr[0] = 0xfc;
+			sc->sc_arpcom.ac_enaddr[1] = 0xfc;
+			bcopy((caddr_t)&IA_SIN(ifa)->sin_addr,
+			      (caddr_t)&sc->sc_arpcom.ac_enaddr[2], 4);
+			sc->sc_arpcom.ac_ipaddr = IA_SIN(ifa)->sin_addr;
+#if defined(COMPAT_PLIP10)
+			if (ifp->if_flags & IFF_LINK0) {
+				int i;
+				sc->sc_arpcom.ac_enaddr[0] = 0xfd;
+				sc->sc_arpcom.ac_enaddr[1] = 0xfd;
+				for (i = sc->sc_adrcksum = 0; i < 5; i++)
+					sc->sc_adrcksum += sc->sc_arpcom.ac_enaddr[i];
+				sc->sc_adrcksum *= 2;
+			}
+#endif
+			ifp->if_flags |= IFF_RUNNING | IFF_UP;
+#if 0
+			for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next) {
+				struct sockaddr_dl *sdl;
+				if ((sdl = (struct sockaddr_dl *)ifa->ifa_addr) &&
+				    sdl->sdl_family == AF_LINK) {
+					sdl->sdl_type = IFT_ETHER;
+					sdl->sdl_alen = ifp->if_addrlen;
+					bcopy((caddr_t)((struct arpcom *)ifp)->ac_enaddr,
+					      LLADDR(sdl), ifp->if_addrlen);
+					break;
+				    }
+			}
+#endif
+			sc->sc_i8255->port_control = LPT_IRQDISABLE;
+			sc->sc_i8255->port_b = 0;
+			sc->sc_i8255->port_a |= LPA_ACKENABLE;
+			arp_ifinit(&sc->sc_arpcom, ifa);
+		} else
+			error = EAFNOSUPPORT;
+		break;
+
+	case SIOCAIFADDR:
+	case SIOCDIFADDR:
+	case SIOCSIFDSTADDR:
+		if (ifa->ifa_addr->sa_family != AF_INET)
+			error = EAFNOSUPPORT;
+		break;
+
+	case SIOCSIFMTU:
+        	if ((error = suser(p->p_ucred, &p->p_acflag)))
+            		return(error);
+		if (ifp->if_mtu != ifr->ifr_metric) {
+		        ifp->if_mtu = ifr->ifr_metric;
+			if (sc->sc_ifbuf) {
+				s = splimp();
+				free(sc->sc_ifbuf, M_DEVBUF);
+				sc->sc_ifbuf =
+					malloc(ifp->if_mtu + ifp->if_hdrlen,
+					       M_DEVBUF, M_WAITOK);
+				splx(s);
+			}
+		}
+		break;
+
+        case SIOCGIFMTU:
+	        ifr->ifr_metric = ifp->if_mtu;
+		break;
+
+	default:
+		error = EINVAL;
+	}
+	return (error);
+}
+
+static void
+plipsoftint(struct lpt_softc *sc)
+{
+	int pending = sc->sc_pending;
+
+	while (sc->sc_pending & PLIP_IPENDING) {
+		pending |= sc->sc_pending;
+		sc->sc_pending = 0;
+		plipinput(sc);
+	}
+
+	if (pending & PLIP_OPENDING)
+		plipoutput(sc);
+}
+
+static int
+plipreceive(volatile struct i8255 *i8255, u_char *buf, int len)
+{
+	int i;
+	u_char cksum = 0, c;
+
+	while (len--) {
+		i = PLIPMXSPIN2;
+		while ((i8255->port_c & LPC_NBUSY) != 0)
+			if (i-- < 0) return -1;
+		c = i8255->port_c >> 4;
+		i8255->port_b = 0x11;
+		while ((i8255->port_c & LPC_NBUSY) == 0)
+			if (i-- < 0) return -1;
+		c |= i8255->port_c & 0xf0;
+		i8255->port_b = 0x01;
+		cksum += (*buf++ = c);
+	}
+	return(cksum);
+}
+
+static void
+plipinput(struct lpt_softc *sc)
+{
+	extern struct mbuf *m_devget(char *, int, int, struct ifnet *, void (*)());
+	struct ifnet *ifp = &sc->sc_arpcom.ac_if;
+	volatile struct i8255 *i8255 = sc->sc_i8255;
+	struct mbuf *m;
+	struct ether_header *eh;
+	u_char *p = sc->sc_ifbuf, minibuf[4];
+	int c, i = 0, s, len, cksum;
+
+	if (!(i8255->port_c & LPC_NACK)) {
+		i8255->port_a |= LPA_ACKENABLE;
+		ifp->if_collisions++;
+		return;
+	}
+	i8255->port_b = 0x01;
+	i8255->port_a &= ~(LPA_ACKENABLE | LPA_ACTIVE);
+
+#if defined(COMPAT_PLIP10)
+	if (ifp->if_flags & IFF_LINK0) {
+		if (plipreceive(i8255, minibuf, 3) < 0) goto err;
+		len = (minibuf[1] << 8) | minibuf[2];
+		if (len > (ifp->if_mtu + ifp->if_hdrlen)) goto err;
+
+		switch (minibuf[0]) {
+		case 0xfc:
+			p[0] = p[ 6] = ifp->ac_enaddr[0];
+			p[1] = p[ 7] = ifp->ac_enaddr[1];
+			p[2] = p[ 8] = ifp->ac_enaddr[2];
+			p[3] = p[ 9] = ifp->ac_enaddr[3];
+			p[4] = p[10] = ifp->ac_enaddr[4];
+			p += 5;
+			if ((cksum = plipreceive(i8255, p, 1)) < 0) goto err;
+			p += 6;
+			if ((c = plipreceive(i8255, p, len - 11)) < 0) goto err;
+			cksum += c + sc->sc_adrcksum;
+			c = p[1]; p[1] = p[2]; p[2] = c;
+			cksum &= 0xff;
+			break;
+		case 0xfd:
+			if ((cksum = plipreceive(i8255, p, len)) < 0) goto err;
+			break;
+		default:
+			goto err;
+		}
+	} else
+#endif
+	{
+		if (plipreceive(i8255, minibuf, 2) < 0) goto err;
+		len = (minibuf[1] << 8) | minibuf[0];
+		if (len > (ifp->if_mtu + ifp->if_hdrlen)) {
+			log(LOG_NOTICE, "plip%d: packet > MTU\n", ifp->if_unit);
+			goto err;
+		}
+		if ((cksum = plipreceive(i8255, p, len)) < 0) goto err;
+	}
+
+	if (plipreceive(i8255, minibuf, 1) < 0) goto err;
+	if (cksum != minibuf[0]) {
+		log(LOG_NOTICE, "plip%d: checksum error\n", ifp->if_unit);
+		goto err;
+	}
+	i8255->port_b = 0x00;
+
+	s = splimp();
+	if (m = m_devget(sc->sc_ifbuf, len, 0, ifp, NULL)) {
+		/* We assume that the header fit entirely in one mbuf. */
+		eh = mtod(m, struct ether_header *);
+		m->m_pkthdr.len -= sizeof(*eh);
+		m->m_len -= sizeof(*eh);
+		m->m_data += sizeof(*eh);
+		ether_input(ifp, eh, m);
+	}
+	splx(s);
+	sc->sc_ifierrs = 0;
+	ifp->if_ipackets++;
+	i8255->port_a |= LPA_ACKENABLE | LPA_ACTIVE;
+	return;
+
+err:
+	i8255->port_b = 0x00;
+
+	if (sc->sc_ifierrs < PLIPMXERRS) {
+		i8255->port_a |= LPA_ACKENABLE | LPA_ACTIVE;
+	} else {
+		/* We are not able to send receive anything for now,
+		 * so stop wasting our time and leave the interrupt
+		 * disabled.
+		 */
+		if (sc->sc_ifierrs == PLIPMXERRS)
+			log(LOG_NOTICE, "plip%d: rx hard error\n", ifp->if_unit);
+		i8255->port_a |= LPA_ACTIVE;
+	}
+	ifp->if_ierrors++;
+	sc->sc_ifierrs++;
+	return;
+}
+
+static int
+pliptransmit(volatile struct i8255 *i8255, u_char *buf, int len)
+{
+	int i;
+	u_char cksum = 0, c;
+
+	while (len--) {
+		i = PLIPMXSPIN2;
+		cksum += (c = *buf++);
+		while ((i8255->port_c & LPC_NBUSY) == 0)
+			if (i-- < 0) return -1;
+		i8255->port_b = c & 0x0f;
+		i8255->port_b = c & 0x0f | 0x10;
+		c >>= 4;
+		while ((i8255->port_c & LPC_NBUSY) != 0)
+			if (i-- < 0) return -1;
+		i8255->port_b = c | 0x10;
+		i8255->port_b = c;
+	}
+	return(cksum);
+}
+
+/*
+ * Setup output on interface.
+ */
+static void
+plipstart(struct ifnet *ifp)
+{
+	struct lpt_softc *sc = (struct lpt_softc *) lptcd.cd_devs[ifp->if_unit];
+	sc->sc_pending |= PLIP_OPENDING;
+	softintr(sc->sc_ifsoftint);
+}
+
+static void
+plipoutput(struct lpt_softc *sc)
+{
+	struct ifnet *ifp = &sc->sc_arpcom.ac_if;
+	volatile struct i8255 *i8255 = sc->sc_i8255;
+	struct mbuf *m0, *m;
+	u_char minibuf[4], cksum;
+	int len, i, s;
+
+	if (ifp->if_flags & IFF_OACTIVE)
+		return;
+	ifp->if_flags |= IFF_OACTIVE;
+
+	if (sc->sc_ifoerrs)
+		untimeout((void (*)(void *))plipoutput, sc);
+
+	for (;;) {
+		s = splnet();
+		IF_DEQUEUE(&ifp->if_snd, m0);
+		splx(s);
+		if (!m0)
+			break;
+
+		for (len = 0, m = m0; m; m = m->m_next)
+			len += m->m_len;
+#if defined(COMPAT_PLIP10)
+		if (ifp->if_flags & IFF_LINK0) {
+			minibuf[0] = 3;
+			minibuf[1] = 0xfd;
+			minibuf[2] = len >> 8;
+			minibuf[3] = len;
+		} else
+#endif
+		{
+			minibuf[0] = 2;
+			minibuf[1] = len;
+			minibuf[2] = len >> 8;
+		}
+
+		/* Trigger remote interrupt */
+		i = PLIPMXSPIN1;
+		do {
+			if (sc->sc_pending & PLIP_IPENDING) {
+				i8255->port_b = 0x00;
+				sc->sc_pending = 0;
+				plipinput(sc);
+				i = PLIPMXSPIN1;
+			} else if (i-- < 0)
+				goto retry;
+			/* Retrigger remote interrupt */
+			i8255->port_b = 0x08;
+		} while ((i8255->port_c & LPC_NERROR) == 0);
+		i8255->port_a &= ~(LPA_ACKENABLE | LPA_ACTIVE);
+
+		if (pliptransmit(i8255, minibuf + 1, minibuf[0]) < 0) goto retry;
+		for (cksum = 0, m = m0; m; m = m->m_next) {
+			i = pliptransmit(i8255, mtod(m, u_char *), m->m_len);
+			if (i < 0) goto retry;
+			cksum += i;
+		}
+		if (pliptransmit(i8255, &cksum, 1) < 0) goto retry;
+		i = PLIPMXSPIN2;
+		while ((i8255->port_c & LPC_NBUSY) == 0)
+			if (i-- < 0) goto retry;
+		i8255->port_b = 0x00;
+
+		ifp->if_opackets++;
+		ifp->if_obytes += len + 4;
+		sc->sc_ifoerrs = 0;
+		s = splimp();
+		m_freem(m0);
+		splx(s);
+		i8255->port_a |= LPA_ACKENABLE;
+	}
+	i8255->port_a |= LPA_ACTIVE;
+	ifp->if_flags &= ~IFF_OACTIVE;
+	return;
+
+retry:
+	if (i8255->port_c & LPC_NACK)
+		ifp->if_collisions++;
+	else
+		ifp->if_oerrors++;
+
+	ifp->if_flags &= ~IFF_OACTIVE;
+	i8255->port_b = 0x00;
+
+	if ((ifp->if_flags & (IFF_RUNNING | IFF_UP)) == (IFF_RUNNING | IFF_UP)
+	    && sc->sc_ifoerrs < PLIPMXRETRY) {
+		s = splnet();
+		IF_PREPEND(&ifp->if_snd, m0);
+		splx(s);
+		i8255->port_a |= LPA_ACKENABLE | LPA_ACTIVE;
+		timeout((void (*)(void *))plipoutput, sc, PLIPRETRY);
+	} else {
+		if (sc->sc_ifoerrs == PLIPMXRETRY) {
+			log(LOG_NOTICE, "plip%d: tx hard error\n", ifp->if_unit);
+		}
+		s = splimp();
+		m_freem(m0);
+		splx(s);
+		i8255->port_a |= LPA_ACTIVE;
+	}
+	sc->sc_ifoerrs++;
+}
+
+#endif