/*-
 * Copyright (c) 2000 Doug Rabson
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 AUTHOR OR CONTRIBUTORS 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.
 *
 *	$FreeBSD$
 */
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/tty.h>
#include <sys/proc.h>
#include <sys/cons.h>

#include <vm/vm.h>
#include <vm/vm_param.h>
#include <sys/lock.h>
#include <vm/vm_kern.h>
#include <vm/vm_page.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <vm/vm_extern.h>
#include <vm/vm_pageout.h>
#include <vm/vm_pager.h>
#include <vm/vm_zone.h>

#define SSC_GETCHAR			21
#define SSC_PUTCHAR			31

#define	SSC_POLL_HZ	50

static	d_open_t	sscopen;
static	d_close_t	sscclose;
static	d_ioctl_t	sscioctl;

#define CDEV_MAJOR 97
static struct cdevsw ssc_cdevsw = {
	/* open */	sscopen,
	/* close */	sscclose,
	/* read */	ttyread,
	/* write */	ttywrite,
	/* ioctl */	sscioctl,
	/* poll */	ttypoll,
	/* mmap */	nommap,
	/* strategy */	nostrategy,
	/* name */	"ssc",
	/* maj */	CDEV_MAJOR,
	/* dump */	nodump,
	/* psize */	nopsize,
	/* flags */	0,
};

static struct tty *ssc_tp = NULL;
static int polltime;
static struct callout_handle ssctimeouthandle
	= CALLOUT_HANDLE_INITIALIZER(&ssctimeouthandle);

static void	sscstart(struct tty *);
static void	ssctimeout(void *);
static int	sscparam(struct tty *, struct termios *);
static void	sscstop(struct tty *, int);

static u_int64_t
ssc(u_int64_t in0, u_int64_t in1, u_int64_t in2, u_int64_t in3, int which)
{
	register u_int64_t ret0 __asm("r8");

	__asm __volatile("mov r15=%1\n\t"
			 "break 0x80001"
			 : "=r"(ret0)
			 : "r"(which), "r"(in0), "r"(in1), "r"(in2), "r"(in3));
	return ret0;
}

static void
ssccnputc(dev_t dev, int c)
{
	ssc(c, 0, 0, 0, SSC_PUTCHAR);
}

static int
ssccngetc(dev_t dev)
{
	int c;
	do {
		c = ssc(0, 0, 0, 0, SSC_GETCHAR);
	} while (c == 0);

	return c;
}

static int
ssccncheckc(dev_t dev)
{
    int c;
    c = ssc(0, 0, 0, 0, SSC_GETCHAR);
    if (!c)
	    return -1;
    return c;
}

static int
sscopen(dev_t dev, int flag, int mode, struct proc *p)
{
	struct tty *tp;
	int s;
	int error = 0, setuptimeout = 0;
 
	tp = ssc_tp = dev->si_tty = ttymalloc(ssc_tp);

	s = spltty();
	tp->t_oproc = sscstart;
	tp->t_param = sscparam;
	tp->t_stop = sscstop;
	tp->t_dev = dev;
	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 = TTYDEF_SPEED;
		ttsetwater(tp);

		setuptimeout = 1;
	} else if ((tp->t_state & TS_XCLUDE) && suser(p)) {
		splx(s);
		return EBUSY;
	}

	splx(s);

	error = (*linesw[tp->t_line].l_open)(dev, tp);

	if (error == 0 && setuptimeout) {
		polltime = hz / SSC_POLL_HZ;
		if (polltime < 1)
			polltime = 1;
		ssctimeouthandle = timeout(ssctimeout, tp, polltime);
	}
	return error;
}
 
static int
sscclose(dev_t dev, int flag, int mode, struct proc *p)
{
	int unit = minor(dev);
	struct tty *tp = ssc_tp;

	if (unit != 0)
		return ENXIO;

	untimeout(ssctimeout, tp, ssctimeouthandle);
	(*linesw[tp->t_line].l_close)(tp, flag);
	ttyclose(tp);
	return 0;
}
 
static int
sscioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
{
	int unit = minor(dev);
	struct tty *tp = ssc_tp;
	int error;

	if (unit != 0)
		return ENXIO;

	error = (*linesw[tp->t_line].l_ioctl)(tp, cmd, data, flag, p);
	if (error != ENOIOCTL)
		return error;
	error = ttioctl(tp, cmd, data, flag);
	if (error != ENOIOCTL)
		return error;

	return ENOTTY;
}

static int
sscparam(struct tty *tp, struct termios *t)
{

	return 0;
}

static void
sscstart(struct tty *tp)
{
	int s;

	s = spltty();

	if (tp->t_state & (TS_TIMEOUT | TS_TTSTOP)) {
		ttwwakeup(tp);
		splx(s);
		return;
	}

	tp->t_state |= TS_BUSY;
	while (tp->t_outq.c_cc != 0)
		ssccnputc(tp->t_dev, getc(&tp->t_outq));
	tp->t_state &= ~TS_BUSY;

	ttwwakeup(tp);
	splx(s);
}

/*
 * Stop output on a line.
 */
static void
sscstop(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 void
ssctimeout(void *v)
{
	struct tty *tp = v;
	int c;

	while ((c = ssccncheckc(tp->t_dev)) != -1) {
		if (tp->t_state & TS_ISOPEN)
			(*linesw[tp->t_line].l_rint)(c, tp);
	}
	ssctimeouthandle = timeout(ssctimeout, tp, polltime);
}

CONS_DRIVER(ssc, NULL, NULL, NULL, ssccngetc, ssccncheckc, ssccnputc, NULL);

void
ssccnattach(void)
{
	cn_tab = &ssc_consdev;
	ssc_consdev.cn_pri = CN_NORMAL;
	ssc_consdev.cn_dev = makedev(CDEV_MAJOR, 0);
	make_dev(&ssc_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "ssccons");
}