/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (C) 2001 Benno Rice.
 * 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 Benno Rice ``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 TOOLS GMBH 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.
 */

#include <sys/cdefs.h>
#include "opt_ofw.h"

#include <sys/param.h>
#include <sys/kdb.h>
#include <sys/kernel.h>
#include <sys/priv.h>
#include <sys/systm.h>
#include <sys/types.h>
#include <sys/conf.h>
#include <sys/cons.h>
#include <sys/consio.h>
#include <sys/tty.h>

#include <dev/ofw/openfirm.h>

#include <ddb/ddb.h>

#ifndef OFWCONS_POLL_HZ
#define OFWCONS_POLL_HZ 4       /* 50-100 works best on Ultra2 */
#endif
#define OFBURSTLEN      128     /* max number of bytes to write in one chunk */

static tsw_open_t ofwtty_open;
static tsw_close_t ofwtty_close;
static tsw_outwakeup_t ofwtty_outwakeup;

static struct ttydevsw ofw_ttydevsw = {
        .tsw_flags      = TF_NOPREFIX,
        .tsw_open       = ofwtty_open,
        .tsw_close      = ofwtty_close,
        .tsw_outwakeup  = ofwtty_outwakeup,
};

static int                      polltime;
static struct callout           ofw_timer;

#if defined(KDB)
static int                      alt_break_state;
#endif

static void     ofw_timeout(void *);

static cn_probe_t       ofw_cnprobe;
static cn_init_t        ofw_cninit;
static cn_term_t        ofw_cnterm;
static cn_getc_t        ofw_cngetc;
static cn_putc_t        ofw_cnputc;
static cn_grab_t        ofw_cngrab;
static cn_ungrab_t      ofw_cnungrab;

CONSOLE_DRIVER(ofw);

static void
cn_drvinit(void *unused)
{
        phandle_t options;
        char output[32];
        struct tty *tp;

        if (ofw_consdev.cn_pri != CN_DEAD &&
            ofw_consdev.cn_name[0] != '\0') {
                tp = tty_alloc(&ofw_ttydevsw, NULL);
                tty_makedev(tp, NULL, "%s", "ofwcons");

                /*
                 * XXX: This is a hack and it may result in two /dev/ttya
                 * XXX: devices on platforms where the sab driver works.
                 */
                if ((options = OF_finddevice("/options")) == -1 ||
                    OF_getprop(options, "output-device", output,
                    sizeof(output)) == -1)
                        return;
                if (strlen(output) > 0)
                        tty_makealias(tp, "%s", output);
                callout_init_mtx(&ofw_timer, tty_getlock(tp), 0);
        }
}

SYSINIT(cndev, SI_SUB_CONFIGURE, SI_ORDER_MIDDLE, cn_drvinit, NULL);

static pcell_t  stdin;
static pcell_t  stdout;

static int
ofwtty_open(struct tty *tp)
{
        polltime = hz / OFWCONS_POLL_HZ;
        if (polltime < 1)
                polltime = 1;

        callout_reset(&ofw_timer, polltime, ofw_timeout, tp);

        return (0);
}

static void
ofwtty_close(struct tty *tp)
{

        callout_stop(&ofw_timer);
}

static void
ofwtty_outwakeup(struct tty *tp)
{
        int len;
        u_char buf[OFBURSTLEN];

        for (;;) {
                len = ttydisc_getc(tp, buf, sizeof buf);
                if (len == 0)
                        break;
                OF_write(stdout, buf, len);
        }
}

static void
ofw_timeout(void *v)
{
        struct  tty *tp;
        int     c;

        tp = (struct tty *)v;

        tty_assert_locked(tp);
        while ((c = ofw_cngetc(NULL)) != -1)
                ttydisc_rint(tp, c, 0);
        ttydisc_rint_done(tp);

        callout_schedule(&ofw_timer, polltime);
}

static void
ofw_cnprobe(struct consdev *cp)
{
        int chosen;

        if ((chosen = OF_finddevice("/chosen")) == -1) {
                cp->cn_pri = CN_DEAD;
                return;
        }

        if (OF_getencprop(chosen, "stdin", &stdin, sizeof(stdin)) == -1) {
                cp->cn_pri = CN_DEAD;
                return;
        }

        if (OF_getencprop(chosen, "stdout", &stdout, sizeof(stdout)) == -1) {
                cp->cn_pri = CN_DEAD;
                return;
        }

        cp->cn_pri = CN_LOW;
}

static void
ofw_cninit(struct consdev *cp)
{

        /* XXX: This is the alias, but that should be good enough */
        strcpy(cp->cn_name, "ofwcons");
}

static void
ofw_cnterm(struct consdev *cp)
{
}

static void
ofw_cngrab(struct consdev *cp)
{
}

static void
ofw_cnungrab(struct consdev *cp)
{
}

static int
ofw_cngetc(struct consdev *cp)
{
        unsigned char ch;

        if (OF_read(stdin, &ch, 1) > 0) {
#if defined(KDB)
                kdb_alt_break(ch, &alt_break_state);
#endif
                return (ch);
        }

        return (-1);
}

static void
ofw_cnputc(struct consdev *cp, int c)
{
        char cbuf;

        if (c == '\n') {
                cbuf = '\r';
                OF_write(stdout, &cbuf, 1);
        }

        cbuf = c;
        OF_write(stdout, &cbuf, 1);
}