/*      $NetBSD: arcbios_tty.c,v 1.25 2014/07/25 08:10:36 dholland Exp $        */

/*
 * Copyright (c) 1994, 1995, 1996 Carnegie-Mellon University.
 * All rights reserved.
 *
 * Author: Chris G. Demetriou
 *
 * Permission to use, copy, modify and distribute this software and
 * its documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 *
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 *
 * Carnegie Mellon requests users of this software to return to
 *
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 *
 * any improvements or extensions that they make and grant Carnegie the
 * rights to redistribute these changes.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: arcbios_tty.c,v 1.25 2014/07/25 08:10:36 dholland Exp $");

#include <sys/param.h>
#include <sys/uio.h>
#include <sys/systm.h>
#include <sys/callout.h>
#include <sys/kernel.h>
#include <sys/conf.h>
#include <sys/proc.h>
#include <sys/tty.h>
#include <sys/termios.h>
#include <sys/kauth.h>

#include <dev/cons.h>

#include <dev/arcbios/arcbios.h>
#include <dev/arcbios/arcbiosvar.h>

callout_t  arcbios_tty_ch;
bool arcbios_ch_init;
static struct tty *arcbios_tty[1];

void    arcbios_tty_start(struct tty *);
void    arcbios_tty_poll(void *);
int     arcbios_tty_param(struct tty *, struct termios *);

dev_type_open(arcbios_ttyopen);
dev_type_close(arcbios_ttyclose);
dev_type_read(arcbios_ttyread);
dev_type_write(arcbios_ttywrite);
dev_type_ioctl(arcbios_ttyioctl);
dev_type_stop(arcbios_ttystop);
dev_type_tty(arcbios_ttytty);
dev_type_poll(arcbios_ttypoll);

const struct cdevsw arcbios_cdevsw = {
        .d_open = arcbios_ttyopen,
        .d_close = arcbios_ttyclose,
        .d_read = arcbios_ttyread,
        .d_write = arcbios_ttywrite,
        .d_ioctl = arcbios_ttyioctl,
        .d_stop = arcbios_ttystop,
        .d_tty = arcbios_ttytty,
        .d_poll = arcbios_ttypoll,
        .d_mmap = nommap,
        .d_kqfilter = ttykqfilter,
        .d_discard = nodiscard,
        .d_flag = D_TTY,
};

int
arcbios_ttyopen(dev_t dev, int flag, int mode, struct lwp *l)
{
        int unit = minor(dev);
        struct tty *tp;
        int s, error = 0, setuptimeout = 0;

        if (!arcbios_ch_init) {
                arcbios_ch_init = true;
                callout_init(&arcbios_tty_ch, 0);
        }

        if (unit != 0)
                return (ENODEV);

        s = spltty();

        if (arcbios_tty[unit] == NULL) {
                tp = arcbios_tty[unit] = tty_alloc();
                tty_attach(tp);
        } else
                tp = arcbios_tty[unit];

        tp->t_oproc = arcbios_tty_start;
        tp->t_param = arcbios_tty_param;
        tp->t_dev = dev;

        if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp)) {
                splx(s);
                return (EBUSY);
        }

        if ((tp->t_state & TS_ISOPEN) == 0) {
                tp->t_state |= TS_CARR_ON;
                ttychars(tp);
                tp->t_iflag = TTYDEF_IFLAG;
                tp->t_oflag = TTYDEF_OFLAG;
                tp->t_cflag = TTYDEF_CFLAG | CLOCAL;
                tp->t_lflag = TTYDEF_LFLAG;
                tp->t_ispeed = tp->t_ospeed = 9600;
                ttsetwater(tp);

                setuptimeout = 1;
        }

        splx(s);

        error = (*tp->t_linesw->l_open)(dev, tp);
        if (error == 0 && setuptimeout)
                callout_reset(&arcbios_tty_ch, 1, arcbios_tty_poll, tp);

        return (error);
}

int
arcbios_ttyclose(dev_t dev, int flag, int mode, struct lwp *l)
{
        int unit = minor(dev);
        struct tty *tp = arcbios_tty[unit];

        callout_stop(&arcbios_tty_ch);
        (*tp->t_linesw->l_close)(tp, flag);
        ttyclose(tp);
        return (0);
}

int
arcbios_ttyread(dev_t dev, struct uio *uio, int flag)
{
        struct tty *tp = arcbios_tty[minor(dev)];

        return ((*tp->t_linesw->l_read)(tp, uio, flag));
}

int
arcbios_ttywrite(dev_t dev, struct uio *uio, int flag)
{
        struct tty *tp = arcbios_tty[minor(dev)];

        return ((*tp->t_linesw->l_write)(tp, uio, flag));
}

int
arcbios_ttypoll(dev_t dev, int events, struct lwp *l)
{
        struct tty *tp = arcbios_tty[minor(dev)];

        return ((*tp->t_linesw->l_poll)(tp, events, l));
}

int
arcbios_ttyioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
{
        int unit = minor(dev);
        struct tty *tp = arcbios_tty[unit];
        int error;

        error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
        if (error != EPASSTHROUGH)
                return (error);
        return (ttioctl(tp, cmd, data, flag, l));
}

int
arcbios_tty_param(struct tty *tp, struct termios *t)
{

        return (0);
}

void
arcbios_tty_start(struct tty *tp)
{
        u_long count;
        int s;

        s = spltty();
        if (tp->t_state & (TS_TTSTOP | TS_BUSY))
                goto out;
        ttypull(tp);
        tp->t_state |= TS_BUSY;
        while (tp->t_outq.c_cc != 0) {
                arcbios_Write(ARCBIOS_STDOUT, tp->t_outq.c_cf,
                    ndqb(&tp->t_outq, 0), &count);
                ndflush(&tp->t_outq, count);
        }
        tp->t_state &= ~TS_BUSY;
 out:
        splx(s);
}

void
arcbios_ttystop(struct tty *tp, int flag)
{
        int s;

        s = spltty();
        if (tp->t_state & TS_BUSY)
                if ((tp->t_state & TS_TTSTOP) == 0)
                        tp->t_state |= TS_FLUSH;
        splx(s);
}

static int
arcbios_tty_getchar(int *cp)
{
        char c;
        int32_t q;
        u_long count;

        q = arcbios_GetReadStatus(ARCBIOS_STDIN);

        if (q == 0) {
                arcbios_Read(ARCBIOS_STDIN, &c, 1, &count);
                *cp = c;

                return 1;
        }

        return 0;
}

void
arcbios_tty_poll(void *v)
{
        struct tty *tp = v;
        int c;

        while (arcbios_tty_getchar(&c)) {
                if (tp->t_state & TS_ISOPEN)
                        (void)(*tp->t_linesw->l_rint)(c, tp);
        }
        callout_reset(&arcbios_tty_ch, 1, arcbios_tty_poll, tp);
}

struct tty *
arcbios_ttytty(dev_t dev)
{

        if (minor(dev) != 0)
                panic("arcbios_ttytty: bogus");

        return (arcbios_tty[0]);
}