/* $NetBSD: promcons.c,v 1.41 2020/09/03 02:09:09 thorpej 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>                  /* RCS ID & Copyright macro defns */

__KERNEL_RCSID(0, "$NetBSD: promcons.c,v 1.41 2020/09/03 02:09:09 thorpej Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/ioctl.h>
#include <sys/select.h>
#include <sys/tty.h>
#include <sys/proc.h>
#include <sys/file.h>
#include <sys/uio.h>
#include <sys/kernel.h>
#include <sys/syslog.h>
#include <sys/types.h>
#include <sys/device.h>
#include <sys/conf.h>
#include <sys/kauth.h>

#include <uvm/uvm_extern.h>

#include <machine/cpuconf.h>
#include <machine/prom.h>

#ifndef CONSPEED
#define CONSPEED 9600
#endif

#ifdef _PROM_MAY_USE_PROM_CONSOLE

dev_type_open(promopen);
dev_type_close(promclose);
dev_type_read(promread);
dev_type_write(promwrite);
dev_type_ioctl(promioctl);
dev_type_stop(promstop);
dev_type_tty(promtty);
dev_type_poll(prompoll);

const struct cdevsw prom_cdevsw = {
        .d_open = promopen,
        .d_close = promclose,
        .d_read = promread,
        .d_write = promwrite,
        .d_ioctl = promioctl,
        .d_stop = promstop,
        .d_tty = promtty,
        .d_poll = prompoll,
        .d_mmap = nommap,
        .d_kqfilter = ttykqfilter,
        .d_discard = nodiscard,
        .d_flag = D_TTY
};

#define PROM_POLL_HZ    50

static struct  tty *prom_tty[1];
static int polltime;

void    promstart(struct tty *);
void    promtimeout(void *);
int     promparam(struct tty *, struct termios *);

struct callout prom_ch;

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

        if (!callo) {
                callout_init(&prom_ch, 0);
                callo = true;
        }

        if (!prom_uses_prom_console() || unit >= 1)
                return ENXIO;

        s = spltty();

        if (!prom_tty[unit]) {
                tp = prom_tty[unit] = tty_alloc();
                tty_attach(tp);
        } else
                tp = prom_tty[unit];

        tp->t_oproc = promstart;
        tp->t_param = promparam;
        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 = CONSPEED;
                ttsetwater(tp);

                setuptimeout = 1;
        }

        splx(s);

        error = (*tp->t_linesw->l_open)(dev, tp);
        if (error == 0 && setuptimeout) {
                polltime = hz / PROM_POLL_HZ;
                if (polltime < 1)
                        polltime = 1;
                callout_reset(&prom_ch, polltime, promtimeout, tp);
        }
        return error;
}

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

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

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

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

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

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

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

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

int
promioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
{
        int unit = minor(dev);
        struct tty *tp = prom_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
promparam(struct tty *tp, struct termios *t)
{

        return 0;
}

void
promstart(struct tty *tp)
{
        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)
                promcnputc(tp->t_dev, getc(&tp->t_outq));
        tp->t_state &= ~TS_BUSY;
out:
        splx(s);
}

/*
 * Stop output on a line.
 */
void
promstop(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);
}

void
promtimeout(void *v)
{
        struct tty *tp = v;
        u_char c;

        while (promcnlookc(tp->t_dev, &c)) {
                if (tp->t_state & TS_ISOPEN)
                        (*tp->t_linesw->l_rint)(c, tp);
        }
        callout_reset(&prom_ch, polltime, promtimeout, tp);
}

struct tty *
promtty(dev_t dev)
{

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

        return prom_tty[0];
}

#else /* _PROM_MAY_USE_PROM_CONSOLE */

/*
 * If not defined _PROM_MAY_USE_PROM_CONSOLE,
 * this fake prom_cdevsw is attached to the kernel.
 * NEVER REMOVE!
 */
const struct cdevsw prom_cdevsw = {
        .d_open = noopen,
        .d_close = noclose,
        .d_read = noread,
        .d_write = nowrite,
        .d_ioctl = noioctl,
        .d_stop = nostop,
        .d_tty = notty,
        .d_poll = nopoll,
        .d_mmap = nommap,
        .d_kqfilter = nokqfilter,
        .d_discard = nodiscard,
        .d_flag = 0
};

#endif /* _PROM_MAY_USE_PROM_CONSOLE */