/*      $NetBSD: lpt.c,v 1.40 2023/01/06 10:28:28 tsutsui Exp $ */

/*
 * Copyright (c) 1996 Leo Weppelman
 * 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 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 originally written for AT parallel printer port. Now
 * drives the printer port on the YM2149.
 *
 * 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.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: lpt.c,v 1.40 2023/01/06 10:28:28 tsutsui Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/callout.h>
#include <sys/proc.h>
#include <sys/buf.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 <machine/cpu.h>
#include <machine/iomap.h>
#include <machine/mfp.h>
#include <machine/intr.h>

#include <atari/dev/ym2149reg.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

#if !defined(DEBUG) || !defined(notdef)
#define lprintf         if (0) aprint_error_dev
#else
#define lprintf         if (lptdebug) aprint_error_dev
int lptdebug = 1;
#endif

struct lpt_softc {
        device_t        sc_dev;
        struct callout  sc_wakeup_ch;
        size_t          sc_count;
        struct buf      *sc_inbuf;
        u_char          *sc_cp;
        int             sc_spinmax;
        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 XXX: LWP - not yet... */
#define LPT_NOINTR      0x40    /* do not use interrupt */
        void            *sc_sicookie;
};

#define LPTUNIT(s)      (minor(s) & 0x1f)
#define LPTFLAGS(s)     (minor(s) & 0xe0)
#define NOT_READY()     (MFP->mf_gpip & IO_PBSY)

/* {b,c}devsw[] function prototypes */
static dev_type_open(lpopen);
static dev_type_close(lpclose);
static dev_type_write(lpwrite);
static dev_type_ioctl(lpioctl);

static void lptwakeup (void *arg);
static int pushbytes (struct lpt_softc *);
static void lptpseudointr (void *);
int lptintr (struct lpt_softc *);
int lpthwintr (void *);


/*
 * Autoconfig stuff
 */
static void lpattach (device_t, device_t, void *);
static int  lpmatch (device_t, cfdata_t , void *);

CFATTACH_DECL_NEW(lp, sizeof(struct lpt_softc),
    lpmatch, lpattach, NULL, NULL);

const struct cdevsw lp_cdevsw = {
        .d_open = lpopen,
        .d_close = lpclose,
        .d_read = noread,
        .d_write = lpwrite,
        .d_ioctl = lpioctl,
        .d_stop = nostop,
        .d_tty = notty,
        .d_poll = nopoll,
        .d_mmap = nommap,
        .d_kqfilter = nokqfilter,
        .d_discard = nodiscard,
        .d_flag = 0
};

/*ARGSUSED*/
static  int
lpmatch(device_t parent, cfdata_t cf, void *aux)
{
        static int      lpt_matched = 0;

        /* Match at most 1 lpt unit */
        if (strcmp((char *)aux, "lpt") || lpt_matched)
                return 0;
        lpt_matched = 1;
        return (1);
}

/*ARGSUSED*/
static void
lpattach(device_t parent, device_t self, void *aux)
{
        struct lpt_softc *sc = device_private(self);

        sc->sc_dev = self;
        sc->sc_state = 0;

        aprint_normal("\n");

        if (intr_establish(0, USER_VEC, 0, (hw_ifun_t)lpthwintr, sc) == NULL)
                aprint_error_dev(self, "Can't establish interrupt\n");
        ym2149_strobe(1);
        sc->sc_sicookie = softint_establish(SOFTINT_SERIAL, lptpseudointr, sc);

        callout_init(&sc->sc_wakeup_ch, 0);
}

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

        sc = device_lookup_private(&lp_cd, LPTUNIT(dev));
        if (!sc)
                return ENXIO;

#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(sc->sc_dev, "open: flags=0x%x\n", flags);

        /* wait till ready (printer running diagnostics) */
        for (spin = 0; NOT_READY(); 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((void *)sc, LPTPRI | PCATCH, "lptopen",
                     STEP)) != EWOULDBLOCK) {
                        sc->sc_state = 0;
                        return error;
                }
        }

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

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

                sps = splhigh();
                MFP->mf_imrb |= IB_PBSY;
                MFP->mf_ierb |= IB_PBSY;
                splx(sps);
        }

        lprintf(sc->sc_dev, "opened\n");
        return 0;
}

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

        lptpseudointr(sc);

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

/*
 * Close the device, and free the local line buffer.
 */
static int
lpclose(dev_t dev, int flag, int mode, struct lwp *l)
{
        struct lpt_softc *sc = device_lookup_private(&lp_cd, LPTUNIT(dev));
        int              sps;

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

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

                sps = splhigh();
                MFP->mf_ierb &= ~IB_PBSY;
                MFP->mf_imrb &= ~IB_PBSY;
                splx(sps);
        }

        sc->sc_state = 0;
        brelse(sc->sc_inbuf, 0);

        lprintf(sc->sc_dev, "closed\n");
        return 0;
}

int
pushbytes(struct lpt_softc *sc)
{
        int     error;

        if (sc->sc_flags & LPT_NOINTR) {
                int spin, tic;

                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()) {
                                        /* 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;
                        }

                        ym2149_write_ioport(YM_IOB, *sc->sc_cp++);
                        ym2149_strobe(0);
                        sc->sc_count--;
                        ym2149_strobe(1);

                        /* adapt busy-wait algorithm */
                        if (spin*2 + 16 < sc->sc_spinmax)
                                sc->sc_spinmax--;
                }
        } else {
                while (sc->sc_count > 0) {
                        /* if the printer is ready for a char, give it one */
                        if ((sc->sc_state & LPT_OBUSY) == 0) {
                                lprintf(sc->sc_dev, "write %d\n",
                                    sc->sc_count);
                                (void) lptpseudointr(sc);
                        }
                        if ((error = tsleep((void *)sc, LPTPRI | PCATCH,
                             "lptwrite2", 0)) != 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.
 */
static int
lpwrite(dev_t dev, struct uio *uio, int flags)
{
        struct lpt_softc *sc = device_lookup_private(&lp_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->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(struct lpt_softc *sc)
{
        /* is printer online and ready for output */
        if (NOT_READY())
                return 0;

        if (sc->sc_count) {

                /* send char */
                ym2149_write_ioport(YM_IOB, *sc->sc_cp++);
                ym2149_strobe(0);
                sc->sc_count--;
                ym2149_strobe(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 */
                wakeup((void *)sc);
        }

        return 1;
}

static void
lptpseudointr(void *arg)
{
        struct lpt_softc *sc;
        int     s;

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

int
lpthwintr(void *arg)
{
        struct lpt_softc *sc;

        sc = arg;
        softint_schedule(sc->sc_sicookie);
        return 1;
}

static int
lpioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
{
        int error = 0;

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

        return error;
}