/*      $NetBSD: lpt.c,v 1.82 2018/09/03 16:29:31 riastradh Exp $       */

/*
 * Copyright (c) 1993, 1994 Charles M. 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 style parallel printer port
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: lpt.c,v 1.82 2018/09/03 16:29:31 riastradh Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/kernel.h>
#include <sys/ioctl.h>
#include <sys/uio.h>
#include <sys/device.h>
#include <sys/conf.h>
#include <sys/syslog.h>
#include <sys/intr.h>

#include <sys/bus.h>

#include <dev/ic/lptreg.h>
#include <dev/ic/lptvar.h>

#include "ioconf.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

#define LPTDEBUG

#ifndef LPTDEBUG
#define LPRINTF(a)
#else
#define LPRINTF(a)      if (lptdebug) printf a
int lptdebug = 0;
#endif

dev_type_open(lptopen);
dev_type_close(lptclose);
dev_type_write(lptwrite);
dev_type_ioctl(lptioctl);

const struct cdevsw lpt_cdevsw = {
        .d_open = lptopen,
        .d_close = lptclose,
        .d_read = noread,
        .d_write = lptwrite,
        .d_ioctl = lptioctl,
        .d_stop = nostop,
        .d_tty = notty,
        .d_poll = nopoll,
        .d_mmap = nommap,
        .d_kqfilter = nokqfilter,
        .d_discard = nodiscard,
        .d_flag = D_OTHER
};

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

static void     lptsoftintr(void *);

void
lpt_attach_subr(struct lpt_softc *sc)
{
        bus_space_tag_t iot;
        bus_space_handle_t ioh;

        sc->sc_state = 0;

        iot = sc->sc_iot;
        ioh = sc->sc_ioh;

        bus_space_write_1(iot, ioh, lpt_control, LPC_NINIT);

        callout_init(&sc->sc_wakeup_ch, 0);
        sc->sc_sih = softint_establish(SOFTINT_SERIAL, lptsoftintr, sc);

        sc->sc_dev_ok = 1;
}

int
lpt_detach_subr(device_t self, int flags)
{
        struct lpt_softc *sc = device_private(self);

        sc->sc_dev_ok = 0;
        softint_disestablish(sc->sc_sih);
        callout_destroy(&sc->sc_wakeup_ch);
        return 0;
}

/*
 * Reset the printer, then wait until it's selected and not busy.
 */
int
lptopen(dev_t dev, int flag, int mode, struct lwp *l)
{
        u_char flags = LPTFLAGS(dev);
        struct lpt_softc *sc;
        bus_space_tag_t iot;
        bus_space_handle_t ioh;
        u_char control;
        int error;
        int spin;

        sc = device_lookup_private(&lpt_cd, LPTUNIT(dev));
        if (!sc || !sc->sc_dev_ok)
                return ENXIO;

#if 0   /* XXX what to do? */
        if (sc->sc_irq == IRQUNK && (flags & LPT_NOINTR) == 0)
                return ENXIO;
#endif

#ifdef DIAGNOSTIC
        if (sc->sc_state)
                aprint_verbose_dev(sc->sc_dev, "stat=0x%x not zero\n",
                    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", device_xname(sc->sc_dev),
            (unsigned)flags));
        iot = sc->sc_iot;
        ioh = sc->sc_ioh;

        if ((flags & LPT_NOPRIME) == 0) {
                /* assert INIT for 100 usec to start up printer */
                bus_space_write_1(iot, ioh, lpt_control, LPC_SELECT);
                delay(100);
        }

        control = LPC_SELECT | LPC_NINIT;
        bus_space_write_1(iot, ioh, 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 */
                error = tsleep((void *)sc, LPTPRI | PCATCH, "lptopen", STEP);
                if (error != 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;
        bus_space_write_1(iot, ioh, lpt_control, control);

        sc->sc_inbuf = malloc(LPT_BSIZE, M_DEVBUF, M_WAITOK);
        sc->sc_count = 0;
        sc->sc_state = LPT_OPEN;

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

        LPRINTF(("%s: opened\n", device_xname(sc->sc_dev)));
        return 0;
}

int
lptnotready(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 (sc->sc_state & LPT_OPEN) {
                if (new & LPS_SELECT)
                        log(LOG_NOTICE,
                            "%s: offline\n", device_xname(sc->sc_dev));
                else if (new & LPS_NOPAPER)
                        log(LOG_NOTICE,
                            "%s: out of paper\n", device_xname(sc->sc_dev));
                else if (new & LPS_NERR)
                        log(LOG_NOTICE,
                            "%s: output error\n", device_xname(sc->sc_dev));
        }

        return status;
}

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

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

        callout_reset(&sc->sc_wakeup_ch, STEP, lptwakeup, sc);
}

/*
 * Close the device, and free the local line buffer.
 */
int
lptclose(dev_t dev, int flag, int mode,
    struct lwp *l)
{
        struct lpt_softc *sc =
            device_lookup_private(&lpt_cd, LPTUNIT(dev));
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;

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

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

        bus_space_write_1(iot, ioh, lpt_control, LPC_NINIT);
        sc->sc_state = 0;
        bus_space_write_1(iot, ioh, lpt_control, LPC_NINIT);
        free(sc->sc_inbuf, M_DEVBUF);

        LPRINTF(("%s: closed\n", device_xname(sc->sc_dev)));
        return 0;
}

int
lptpushbytes(struct lpt_softc *sc)
{
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
        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((void *)sc,
                                            LPTPRI | PCATCH, "lptpsh", tic);
                                        if (error != EWOULDBLOCK)
                                                return error;
                                }
                                break;
                        }

                        bus_space_write_1(iot, ioh, lpt_data, *sc->sc_cp++);
                        DELAY(1);
                        bus_space_write_1(iot, ioh, lpt_control,
                            control | LPC_STROBE);
                        DELAY(1);
                        sc->sc_count--;
                        bus_space_write_1(iot, ioh, lpt_control, control);
                        DELAY(1);

                        /* 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 %lu\n",
                                    device_xname(sc->sc_dev),
                                    (u_long)sc->sc_count));
                                s = splvm();
                                (void) lptintr(sc);
                                splx(s);
                        }
                        error = tsleep((void *)sc, LPTPRI | PCATCH,
                            "lptwrite2", 0);
                        if (error)
                                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.
 */
int
lptwrite(dev_t dev, struct uio *uio, int flags)
{
        struct lpt_softc *sc =
            device_lookup_private(&lpt_cd, LPTUNIT(dev));
        size_t n;
        int error = 0;

        while ((n = uimin(LPT_BSIZE, uio->uio_resid)) != 0) {
                uiomove(sc->sc_cp = sc->sc_inbuf, n, uio);
                sc->sc_count = n;
                error = lptpushbytes(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(void *arg)
{
        struct lpt_softc *sc = arg;
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;

#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 */
                bus_space_write_1(iot, ioh, lpt_data, *sc->sc_cp++);
                DELAY(1);
                bus_space_write_1(iot, ioh, lpt_control, control | LPC_STROBE);
                DELAY(1);
                sc->sc_count--;
                bus_space_write_1(iot, ioh, lpt_control, control);
                DELAY(1);
                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 */
                softint_schedule(sc->sc_sih);
        }

        return 1;
}

static void
lptsoftintr(void *cookie)
{

        wakeup(cookie);
}

int
lptioctl(dev_t dev, u_long cmd, void *data,
    int flag, struct lwp *l)
{
        return ENODEV;
}