u-boot/cpu/ixp/serial.c

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/*
* (C) Copyright 2002
* Wolfgang Denk, DENX Software Engineering, <wd@denx.de>
*
* (C) Copyright 2002
* Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Marius Groeger <mgroeger@sysgo.de>
*
* (C) Copyright 2002
* Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Alex Zuepke <azu@sysgo.de>
*
* Copyright (C) 1999 2000 2001 Erik Mouw (J.A.K.Mouw@its.tudelft.nl)
*
* 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 <common.h>
#include <asm/arch/ixp425.h>
/*
* 14.7456 MHz
* Baud Rate = --------------
* 16 x Divisor
*/
#define SERIAL_CLOCK 921600
DECLARE_GLOBAL_DATA_PTR;
void serial_setbrg (void)
{
unsigned int quot = 0;
int uart = CFG_IXP425_CONSOLE;
if ((gd->baudrate <= SERIAL_CLOCK) && (SERIAL_CLOCK % gd->baudrate == 0))
quot = SERIAL_CLOCK / gd->baudrate;
else
hang ();
IER(uart) = 0; /* Disable for now */
FCR(uart) = 0; /* No fifos enabled */
/* set baud rate */
LCR(uart) = LCR_WLS0 | LCR_WLS1 | LCR_DLAB;
DLL(uart) = quot & 0xff;
DLH(uart) = quot >> 8;
LCR(uart) = LCR_WLS0 | LCR_WLS1;
IER(uart) = IER_UUE;
}
/*
* Initialise the serial port with the given baudrate. The settings
* are always 8 data bits, no parity, 1 stop bit, no start bits.
*
*/
int serial_init (void)
{
serial_setbrg ();
return (0);
}
/*
* Output a single byte to the serial port.
*/
void serial_putc (const char c)
{
/* wait for room in the tx FIFO on UART */
while ((LSR(CFG_IXP425_CONSOLE) & LSR_TEMT) == 0);
THR(CFG_IXP425_CONSOLE) = c;
/* 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)
{
return LSR(CFG_IXP425_CONSOLE) & LSR_DR;
}
/*
* 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)
{
while (!(LSR(CFG_IXP425_CONSOLE) & LSR_DR));
return (char) RBR(CFG_IXP425_CONSOLE) & 0xff;
}
void
serial_puts (const char *s)
{
while (*s) {
serial_putc (*s++);
}
}