/*	$NetBSD: lpt.c,v 1.25 1994/11/18 22:03:28 mycroft Exp $	*/

/*
 * 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 AT parallel printer port
 */

#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 <machine/cpu.h>
#include <machine/pio.h>

#include <i386/isa/isavar.h>
#include <i386/isa/lptreg.h>

#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(DEBUG) || !defined(notdef)
#define lprintf
#else
#define lprintf		if (lptdebug) printf
int lptdebug = 1;
#endif

struct lpt_softc {
	struct device sc_dev;
	struct intrhand sc_ih;

	size_t sc_count;
	struct buf *sc_inbuf;
	u_char *sc_cp;
	int sc_spinmax;
	int sc_iobase;
	int sc_irq;
	u_char sc_state;
#define	LPT_OPEN	0x01	/* device is open */
#define	LPT_OBUSY	0x02	/* printer is busy doing output */
#define	LPT_INIT	0x04	/* waiting to initialize for open */
	u_char sc_flags;
#define	LPT_AUTOLF	0x20	/* automatic LF on CR */
#define	LPT_NOPRIME	0x40	/* don't prime on open */
#define	LPT_NOINTR	0x80	/* do not use interrupt */
	u_char sc_control;
	u_char sc_laststatus;
};

int lptprobe __P((struct device *, void *, void *));
void lptattach __P((struct device *, struct device *, void *));
int lptintr __P((struct lpt_softc *));

struct cfdriver lptcd = {
	NULL, "lpt", lptprobe, lptattach, DV_TTY, sizeof(struct lpt_softc)
};

#define	LPTUNIT(s)	(minor(s) & 0x1f)
#define	LPTFLAGS(s)	(minor(s) & 0xe0)

#define	LPS_INVERT	(LPS_SELECT|LPS_NERR|LPS_NBSY|LPS_NACK)
#define	LPS_MASK	(LPS_SELECT|LPS_NERR|LPS_NBSY|LPS_NACK|LPS_NOPAPER)
#define	NOT_READY()	((inb(iobase + lpt_status) ^ LPS_INVERT) & LPS_MASK)
#define	NOT_READY_ERR()	not_ready(inb(iobase + lpt_status), sc)
static int not_ready __P((u_char, struct lpt_softc *));

static void lptwakeup __P((void *arg));
static int pushbytes __P((struct lpt_softc *));

/*
 * Internal routine to lptprobe to do port tests of one byte value.
 */
int
lpt_port_test(port, data, mask)
	int port;
	u_char data, mask;
{
	int timeout;
	u_char temp;

	data &= mask;
	outb(port, data);
	timeout = 1000;
	do {
		delay(10);
		temp = inb(port) & mask;
	} while (temp != data && --timeout);
	lprintf("lpt: port=0x%x out=0x%x in=0x%x timeout=%d\n", port, data,
	    temp, timeout);
	return (temp == data);
}

/*
 * Logic:
 *	1) You should be able to write to and read back the same value
 *	   to the data port.  Do an alternating zeros, alternating ones,
 *	   walking zero, and walking one test to check for stuck bits.
 *
 *	2) You should be able to write to and read back the same value
 *	   to the control port lower 5 bits, the upper 3 bits are reserved
 *	   per the IBM PC technical reference manauls and different boards
 *	   do different things with them.  Do an alternating zeros, alternating
 *	   ones, walking zero, and walking one test to check for stuck bits.
 *
 *	   Some printers drag the strobe line down when the are powered off
 * 	   so this bit has been masked out of the control port test.
 *
 *	   XXX Some printers may not like a fast pulse on init or strobe, I
 *	   don't know at this point, if that becomes a problem these bits
 *	   should be turned off in the mask byte for the control port test.
 *
 *	3) Set the data and control ports to a value of 0
 */
int
lptprobe(parent, match, aux)
	struct device *parent;
	void *match, *aux;
{
	struct isa_attach_args *ia = aux;
	int iobase = ia->ia_iobase;
	int port;
	u_char mask, data;
	int i;

#ifdef DEBUG
#define	ABORT	do {printf("lptprobe: mask %x data %x failed\n", mask, data); \
		    return 0;} while (0)
#else
#define	ABORT	return 0
#endif

	port = iobase + lpt_data;
	mask = 0xff;

	for (;;) {
		data = 0x55;				/* Alternating zeros */
		if (!lpt_port_test(port, data, mask))
			ABORT;

		data = 0xaa;				/* Alternating ones */
		if (!lpt_port_test(port, data, mask))
			ABORT;

		for (i = 0; i < CHAR_BIT; i++) {	/* Walking zero */
			data = ~(1 << i);
			if (!lpt_port_test(port, data, mask))
				ABORT;
		}

		for (i = 0; i < CHAR_BIT; i++) {	/* Walking one */
			data = (1 << i);
			if (!lpt_port_test(port, data, mask))
				ABORT;
		}

		if (port == iobase + lpt_data) {
			port = iobase + lpt_control;
#if 1 /* XXX */
			mask = 0x04;
#else
			mask = 0x1e;
#endif
		} else
			break;
	}
	outb(iobase + lpt_data, 0);
	outb(iobase + lpt_control, 0);

	ia->ia_iosize = LPT_NPORTS;
	ia->ia_msize = 0;
	return 1;
}

void
lptattach(parent, self, aux)
	struct device *parent, *self;
	void *aux;
{
	struct lpt_softc *sc = (void *)self;
	struct isa_attach_args *ia = aux;
	int iobase = ia->ia_iobase;

	if (ia->ia_irq != IRQUNK)
		printf("\n");
	else
		printf(": polled\n");

	sc->sc_iobase = iobase;
	sc->sc_irq = ia->ia_irq;
	sc->sc_state = 0;
	outb(iobase + lpt_control, LPC_NINIT);

	if (ia->ia_irq != IRQUNK) {
		sc->sc_ih.ih_fun = lptintr;
		sc->sc_ih.ih_arg = sc;
		sc->sc_ih.ih_level = IPL_NONE;
		intr_establish(ia->ia_irq, &sc->sc_ih);
	}
}

/*
 * Reset the printer, then wait until it's selected and not busy.
 */
int
lptopen(dev, flag)
	dev_t dev;
	int flag;
{
	int unit = LPTUNIT(dev);
	u_char flags = LPTFLAGS(dev);
	struct lpt_softc *sc;
	int iobase;
	u_char control;
	int error;
	int spin;

	if (unit >= lptcd.cd_ndevs)
		return ENXIO;
	sc = lptcd.cd_devs[unit];
	if (!sc)
		return ENXIO;

	if (sc->sc_irq == IRQUNK && (flags & LPT_NOINTR) == 0)
		return ENXIO;

#ifdef DIAGNOSTIC
	if (sc->sc_state)
		printf("%s: stat=0x%x not zero\n", sc->sc_dev.dv_xname,
		    sc->sc_state);
#endif

	if (sc->sc_state)
		return EBUSY;

	sc->sc_state = LPT_INIT;
	sc->sc_flags = flags;
	lprintf("%s: open: flags=0x%x\n", sc->sc_dev.dv_xname, flags);
	iobase = sc->sc_iobase;

	if ((flags & LPT_NOPRIME) == 0) {
		/* assert INIT for 100 usec to start up printer */
		outb(iobase + lpt_control, LPC_SELECT);
		delay(100);
	}

	control = LPC_SELECT | LPC_NINIT;
	outb(iobase + lpt_control, control);

	/* wait till ready (printer running diagnostics) */
	for (spin = 0; NOT_READY_ERR(); 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;
		}
	}

	if ((flags & LPT_NOINTR) == 0)
		control |= LPC_IENABLE;
	if (flags & LPT_AUTOLF)
		control |= LPC_AUTOLF;
	sc->sc_control = control;
	outb(iobase + lpt_control, control);

	sc->sc_inbuf = geteblk(LPT_BSIZE);
	sc->sc_count = 0;
	sc->sc_state = LPT_OPEN;

	if ((sc->sc_flags & LPT_NOINTR) == 0)
		lptwakeup(sc);

	lprintf("%s: opened\n", sc->sc_dev.dv_xname);
	return 0;
}

int
not_ready(status, sc)
	u_char status;
	struct lpt_softc *sc;
{
	u_char new;

	status = (status ^ LPS_INVERT) & LPS_MASK;
	new = status & ~sc->sc_laststatus;
	sc->sc_laststatus = status;

	if (new & LPS_NOPAPER)
		log(LOG_NOTICE, "%s: out of paper\n", sc->sc_dev.dv_xname);
	else if (new & LPS_SELECT)
		log(LOG_NOTICE, "%s: offline\n", sc->sc_dev.dv_xname);
	else if (new & LPS_NERR)
		log(LOG_NOTICE, "%s: output error\n", sc->sc_dev.dv_xname);

	return status;
}

void
lptwakeup(arg)
	void *arg;
{
	struct lpt_softc *sc = arg;
	int s;

	s = spltty();
	lptintr(sc);
	splx(s);

	timeout(lptwakeup, sc, STEP);
}

/*
 * Close the device, and free the local line buffer.
 */
lptclose(dev, flag)
	dev_t dev;
	int flag;
{
	int unit = LPTUNIT(dev);
	struct lpt_softc *sc = lptcd.cd_devs[unit];
	int iobase = sc->sc_iobase;

	if (sc->sc_count)
		(void) pushbytes(sc);

	if ((sc->sc_flags & LPT_NOINTR) == 0)
		untimeout(lptwakeup, sc);

	outb(iobase + lpt_control, LPC_NINIT);
	sc->sc_state = 0;
	outb(iobase + lpt_control, LPC_NINIT);
	brelse(sc->sc_inbuf);

	lprintf("%s: closed\n", sc->sc_dev.dv_xname);
	return 0;
}

int
pushbytes(sc)
	struct lpt_softc *sc;
{
	int iobase = sc->sc_iobase;
	int error;

	if (sc->sc_flags & LPT_NOINTR) {
		int spin, tic;
		u_char control = sc->sc_control;

		while (sc->sc_count > 0) {
			spin = 0;
			while (NOT_READY()) {
				if (++spin < sc->sc_spinmax)
					continue;
				tic = 0;
				/* adapt busy-wait algorithm */
				sc->sc_spinmax++;
				while (NOT_READY_ERR()) {
					/* exponential backoff */
					tic = tic + tic + 1;
					if (tic > TIMEOUT)
						tic = TIMEOUT;
					error = tsleep((caddr_t)sc,
					    LPTPRI | PCATCH, "lptpsh", tic);
					if (error != EWOULDBLOCK)
						return error;
				}
				break;
			}

			outb(iobase + lpt_data, *sc->sc_cp++);
			outb(iobase + lpt_control, control | LPC_STROBE);
			sc->sc_count--;
			outb(iobase + lpt_control, control);

			/* adapt busy-wait algorithm */
			if (spin*2 + 16 < sc->sc_spinmax)
				sc->sc_spinmax--;
		}
	} else {
		int s;

		while (sc->sc_count > 0) {
			/* if the printer is ready for a char, give it one */
			if ((sc->sc_state & LPT_OBUSY) == 0) {
				lprintf("%s: write %d\n", sc->sc_dev.dv_xname,
				    sc->sc_count);
				s = spltty();
				(void) lptintr(sc);
				splx(s);
			}
			if (error = tsleep((caddr_t)sc, LPTPRI | PCATCH,
			    "lptwrite2", 0))
				return error;
		}
	}
	return 0;
}

/* 
 * Copy a line from user space to a local buffer, then call putc to get the
 * chars moved to the output queue.
 */
lptwrite(dev, uio)
	dev_t dev;
	struct uio *uio;
{
	struct lpt_softc *sc = lptcd.cd_devs[LPTUNIT(dev)];
	size_t n;
	int error = 0;

	while (n = min(LPT_BSIZE, uio->uio_resid)) {
		uiomove(sc->sc_cp = sc->sc_inbuf->b_data, 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.
 */
int
lptintr(sc)
	struct lpt_softc *sc;
{
	int iobase = sc->sc_iobase;

#if 0
	if ((sc->sc_state & LPT_OPEN) == 0)
		return 0;
#endif

	/* is printer online and ready for output */
	if (NOT_READY() && NOT_READY_ERR())
		return 0;

	if (sc->sc_count) {
		u_char control = sc->sc_control;
		/* send char */
		outb(iobase + lpt_data, *sc->sc_cp++);
		outb(iobase + lpt_control, control | LPC_STROBE);
		sc->sc_count--;
		outb(iobase + lpt_control, control);
		sc->sc_state |= LPT_OBUSY;
	} else
		sc->sc_state &= ~LPT_OBUSY;

	if (sc->sc_count == 0) {
		/* none, wake up the top half to get more */
		wakeup((caddr_t)sc);
	}

	return 1;
}

int
lptioctl(dev, cmd, data, flag)
	dev_t dev;
	u_long cmd;
	caddr_t data;
	int flag;
{
	int error = 0;

	switch (cmd) {
	default:
		error = ENODEV;
	}

	return error;
}