/*      $NetBSD: ns16550.c,v 1.5 2008/04/29 15:24:50 tsutsui Exp $      */

/*-
* Copyright (c) 2008 Izumi Tsutsui.  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 ``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 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.
*/

#ifdef CONS_SERIAL

#include <lib/libsa/stand.h>
#include <lib/libkern/libkern.h>

#include <dev/ic/comreg.h>

#include <machine/cpu.h>

#include "boot.h"
#include "ns16550.h"

#define CSR_READ(base, reg)             (*(volatile uint8_t *)((base) + (reg)))
#define CSR_WRITE(base, reg, val)                                       \
       do {                                                            \
               *(volatile uint8_t *)((base) + (reg)) = (val);          \
       } while (/* CONSTCOND */ 0)

void *
com_init(int addr, int speed)
{
       uint8_t *com_port;

       com_port = (void *)MIPS_PHYS_TO_KSEG1(COM_BASE + addr);

       CSR_WRITE(com_port, com_lctl, LCR_DLAB);
       speed = comspeed(speed);
       CSR_WRITE(com_port, com_dlbl, speed);
       CSR_WRITE(com_port, com_dlbh, speed >> 8);

       CSR_WRITE(com_port, com_lctl, LCR_PNONE | LCR_8BITS);
       CSR_WRITE(com_port, com_mcr, MCR_RTS | MCR_DTR);
       CSR_WRITE(com_port, com_fifo,
           FIFO_XMT_RST | FIFO_RCV_RST | FIFO_ENABLE);
       CSR_WRITE(com_port, com_ier, 0);

       return com_port;
}

void
com_putc(void *dev, int c)
{
       volatile uint8_t *com_port = dev;

       while ((CSR_READ(com_port, com_lsr) & LSR_TXRDY) == 0)
               ;

       CSR_WRITE(com_port, com_data, c);
}

int
com_getc(void *dev)
{
       volatile uint8_t *com_port = dev;

       while ((CSR_READ(com_port, com_lsr) & LSR_RXRDY) == 0)
               ;

       return CSR_READ(com_port, com_data);
}

int
com_scankbd(void *dev)
{
       volatile uint8_t *com_port = dev;

       if ((CSR_READ(com_port, com_lsr) & LSR_RXRDY) == 0)
               return -1;

       return CSR_READ(com_port, com_data);
}
#endif /* CONS_SERIAL */