/*      $NetBSD: ns16550.c,v 1.5 2022/09/05 14:14:42 tsutsui Exp $      */

/*
 * Copyright (c) 2002 Wasabi Systems, Inc.
 * All rights reserved.
 *
 * Written by Jason R. Thorpe for Wasabi Systems, Inc.
 *
 * 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 product includes software developed for the NetBSD Project by
 *      Wasabi Systems, Inc.
 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
 *    or promote products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``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 WASABI SYSTEMS, INC
 * 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.
 */

/* 
 * This file provides the cons_init() function and console I/O routines
 * for boards that use 16550-compatible UARTs.
 */

#include <sys/types.h>
#include <dev/ic/comreg.h>
#include <lib/libsa/stand.h>

#include "board.h"

#ifdef NS16550_AX4
#define INB(x)          *((volatile uint8_t *) (CONADDR + ((x) * 4)))
#define OUTB(x, v)      *((volatile uint8_t *) (CONADDR + ((x) * 4))) = (v)
#else
#define INB(x)          *((volatile uint8_t *) (CONADDR + (x)))
#define OUTB(x, v)      *((volatile uint8_t *) (CONADDR + (x))) = (v)
#endif

#ifndef NS16550_FREQ
#define NS16550_FREQ    COM_FREQ
#endif

static int
comspeed(int speed)
{
#define divrnd(n, q)    (((n)*2/(q)+1)/2)       /* divide and round off */

        int x, err;

        if (speed <= 0)  
                return (-1);
        x = divrnd((NS16550_FREQ / 16), speed);
        if (x <= 0)
                return (-1);
        err = divrnd((((quad_t)NS16550_FREQ) / 16) * 1000, speed * x) - 1000;
        if (err < 0)
                err = -err; 
        if (err > COM_TOLERANCE)
                return (-1);
        return (x);
#undef divrnd
}

void
cons_init(void)
{
        int rate;

        OUTB(com_cfcr, LCR_DLAB);
        rate = comspeed(CONSPEED);
        OUTB(com_dlbl, rate);
        OUTB(com_dlbh, rate >> 8);
        OUTB(com_cfcr, LCR_8BITS);
        OUTB(com_mcr, MCR_DTR | MCR_RTS); 
        OUTB(com_fifo,
            FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);
        OUTB(com_ier, 0);
}

int
getchar(void)
{
        uint8_t stat;

        while (!ISSET(stat = INB(com_lsr), LSR_RXRDY))
                /* spin */ ;
        return (INB(com_data));
}

static void
iputchar(int c)
{
        uint8_t stat;
        int timo;

        /* Wait for any pending transmission to finish. */
        timo = 50000;   
        while (!ISSET(stat = INB(com_lsr), LSR_TXRDY) && --timo)
                /* spin */ ;

        OUTB(com_data, c);

        /* Wait for this transmission to complete. */
        timo = 1500000;
        while (!ISSET(stat = INB(com_lsr), LSR_TXRDY) && --timo)
                /* spin */ ;

        /* Clear any interrupts generated by this transmission. */
        (void) INB(com_iir);
}

void
putchar(int c)
{

        if (c == '\n')
                iputchar('\r');
        iputchar(c);
}