u-boot/cpu/arm920t/serial.c

178 lines
3.6 KiB
C

/*
* (C) Copyright 2002
* Gary Jennejohn, DENX Software Engineering, <gj@denx.de>
*
* 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>
#if defined(CONFIG_S3C2400) || defined(CONFIG_TRAB)
#include <s3c2400.h>
#elif defined(CONFIG_S3C2410)
#include <s3c2410.h>
#endif
#ifdef CONFIG_SERIAL1
#define UART_NR S3C24X0_UART0
#elif defined(CONFIG_SERIAL2)
# if defined(CONFIG_TRAB)
# error "TRAB supports only CONFIG_SERIAL1"
# endif
#define UART_NR S3C24X0_UART1
#elif defined(CONFIG_SERIAL3)
# if defined(CONFIG_TRAB)
# #error "TRAB supports only CONFIG_SERIAL1"
# endif
#define UART_NR S3C24X0_UART2
#else
#error "Bad: you didn't configure serial ..."
#endif
void serial_setbrg (void)
{
DECLARE_GLOBAL_DATA_PTR;
S3C24X0_UART * const uart = S3C24X0_GetBase_UART(UART_NR);
int i;
unsigned int reg = 0;
/* value is calculated so : (int)(PCLK/16./baudrate) -1 */
reg = get_PCLK() / (16 * gd->baudrate) - 1;
/* FIFO enable, Tx/Rx FIFO clear */
uart->UFCON = 0x07;
uart->UMCON = 0x0;
/* Normal,No parity,1 stop,8 bit */
uart->ULCON = 0x3;
/*
* tx=level,rx=edge,disable timeout int.,enable rx error int.,
* normal,interrupt or polling
*/
uart->UCON = 0x245;
uart->UBRDIV = reg;
#ifdef CONFIG_HWFLOW
uart->UMCON = 0x1; /* RTS up */
#endif
for (i = 0; i < 100; i++);
}
/*
* 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);
}
/*
* 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)
{
S3C24X0_UART * const uart = S3C24X0_GetBase_UART(UART_NR);
/* wait for character to arrive */
while (!(uart->UTRSTAT & 0x1));
return uart->URXH & 0xff;
}
#ifdef CONFIG_HWFLOW
static int hwflow = 0; /* turned off by default */
int hwflow_onoff(int on)
{
switch(on) {
case 0:
default:
break; /* return current */
case 1:
hwflow = 1; /* turn on */
break;
case -1:
hwflow = 0; /* turn off */
break;
}
return hwflow;
}
#endif
#ifdef CONFIG_MODEM_SUPPORT
static int be_quiet = 0;
void disable_putc(void)
{
be_quiet = 1;
}
void enable_putc(void)
{
be_quiet = 0;
}
#endif
/*
* Output a single byte to the serial port.
*/
void serial_putc (const char c)
{
S3C24X0_UART * const uart = S3C24X0_GetBase_UART(UART_NR);
#ifdef CONFIG_MODEM_SUPPORT
if (be_quiet)
return;
#endif
/* wait for room in the tx FIFO */
while (!(uart->UTRSTAT & 0x2));
#ifdef CONFIG_HWFLOW
/* Wait for CTS up */
while(hwflow && !(uart->UMSTAT & 0x1))
;
#endif
uart->UTXH = c;
/* If \n, also do \r */
if (c == '\n')
serial_putc ('\r');
}
/*
* Test whether a character is in the RX buffer
*/
int serial_tstc (void)
{
S3C24X0_UART * const uart = S3C24X0_GetBase_UART(UART_NR);
return uart->UTRSTAT & 0x1;
}
void
serial_puts (const char *s)
{
while (*s) {
serial_putc (*s++);
}
}