serial.c

来自「vxworks bsp 的一个实际例子 完整工程」· C语言 代码 · 共 128 行

/*
 * (C) Copyright 2002
 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
 * Marius Groeger <[e-mail]>
 *
 * (C) Copyright 2002
 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
 * Alex Zuepke <[e-mail]>
 *
 * Copyright (C) 1999 2000 2001 Erik Mouw ([e-mail])
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include "armboot.h"
#include "pxa-regs.h"

void serial_setbrg(bd_t *bd, int baudrate)
{
    unsigned int quot = 0;

    if (baudrate == 1200)        quot = 192;
    else if (baudrate == 9600)   quot = 96;
    else if (baudrate == 19200)  quot = 48;
    else if (baudrate == 38400)  quot = 24;
    else if (baudrate == 57600)  quot = 16;
    else if (baudrate == 115200) quot = 8;
    else hang();

#ifdef CONFIG_FFUART

    CKEN |= CKEN6_FFUART;
        
    FFIER = 0;  /* Disable for now */
    FFFCR = 0;  /* No fifos enabled */

    /* set baud rate */
    FFLCR = LCR_WLS0 | LCR_WLS1 | LCR_DLAB;
    FFDLL = quot & 0xff;
    FFDLH = quot >> 8;
    FFLCR = LCR_WLS0 | LCR_WLS1;

    FFIER = IER_UUE;  /* Enable FFUART */

#elif CONFIG_STUART
#error "Bad: not implemented yet!"
#else
#error "Bad: you didn't configured serial ..."
#endif
}


/*
 * Initialise the serial port with the given baudrate. The settings
 * are always 8 data bits, no parity, 1 stop bit, no start bits.
 *
 */
void serial_init(bd_t *bd)
{
    const char *baudrate;

    if ((baudrate = getenv(bd, "baudrate")) != 0)
      bd->bi_baudrate = simple_strtoul(baudrate, NULL, 10);

    serial_setbrg(bd, bd->bi_baudrate);
}


/*
 * Output a single byte to the serial port.
 */
void serial_putc(const char c)
{
#ifdef CONFIG_FFUART
    /* wait for room in the tx FIFO on FFUART */
    while((FFLSR & LSR_TEMT) == 0) ;

    FFTHR = c;
#elif CONFIG_STUART
#endif

    /* If \n, also do \r */
    if(c == '\n')
      serial_putc('\r');
}

/*
 * Read a single byte from the serial port. Returns 1 on success, 0
 * otherwise. When the function is succesfull, the character read is
 * written into its argument c.
 */
int serial_tstc(void)
{
#ifdef CONFIG_FFUART
    return FFLSR & LSR_DR;
#elif CONFIG_STUART
#endif
}

/*
 * Read a single byte from the serial port. Returns 1 on success, 0
 * otherwise. When the function is succesfull, the character read is
 * written into its argument c.
 */
int serial_getc(void)
{
#ifdef CONFIG_FFUART
    while (!(FFLSR & LSR_DR))
    	;

    return (char)FFRBR & 0xff;
#elif CONFIG_STUART
#endif
}