serial.c.svn-base

RT-Thread是发展中的下一代微内核嵌入式实时操作系统

/*
 * File      : serial.c
 * This file is part of RT-Thread RTOS
 * COPYRIGHT (C) 2006, RT-Thread Development Team
 *
 * The license and distribution terms for this file may be
 * found in the file LICENSE in this distribution or at
 * http://openlab.rt-thread.com/license/LICENSE
 *
 * Change Logs:
 * Date           Author       Notes
 * 2006-03-13     Bernard      first version
 */

#include <rtthread.h>
#include <rthw.h>

#include "s3c2410.h"

#define	USTAT_RCV_READY         0x20   /* receive data ready */ 
#define	USTAT_TXB_EMPTY         0x40   /* tx buffer empty */
#define BPS						19200	/* serial baudrate		*/

extern rt_uint32 PCLK;
void rt_serial_init(void);

/**
 * @addtogroup S3C2410
 */
/*@{*/

/**
 * This function is used to display a string on console, normally, it's 
 * invoked by rt_kprintf
 *
 * @param str the displayed string
 */
void rt_console_puts(const char* str)
{
	while (*str) 
	{
		rt_serial_putc (*str++);
	}
}

/**
 * This function initializes serial
 */
void rt_serial_init()
{	
	unsigned long i, div;
	
	/* FIFO enable, Tx/Rx FIFO clear */
	UFCON0 = 0x07;
	/* disable the flow control */
	UMCON0= 0x0;
	/* Normal,No parity,1 stop,8 bit */
	ULCON0 = 0x3;
	/*
	 * tx=level,rx=edge,disable timeout int.,enable rx error int.,
	 * normal,interrupt or polling
	 */
	UCON0= 0x245;
	/*
	 * UBRDIVn = (int)(PCLK / (bps x 16) ) –1
	 */
	div = (int)(PCLK / (16 * BPS)) - 1;
	
	UBRD0 = div;
	// UBRD0 = 0x500;	/* baudrate = 19200bps */

	UFCON1 = 0x07;
	UMCON0 = 0x0;
	ULCON1 = 0x3;
	UCON1  = 0x245;
	UBRD1 = div;
	// UBRDIV1 = 0x500;

	/* output PCLK to UART0/1, PWMTIMER */
	CLKCON = 0x0D00;

	for (i = 0; i < 100; i++);
}

/**
 * This function read a character from serial without interrupt enable mode 
 *
 * @return the read char
 */
char rt_serial_getc()
{
	while ((USTAT0 & USTAT_RCV_READY) == 0);

	return URXB0;
}

/**
 * This function will write a character to serial without interrupt enable mode
 *
 * @param c the char to write
 */
void rt_serial_putc(const char c)
{
	/*
		to be polite with serial console add a line feed
		to the carriage return character
	*/
	if (c=='\n')rt_serial_putc('\r');

	/* wait for room in the transmit FIFO */
	while(!(USTAT0 & USTAT_TXB_EMPTY));

	UTXH0 = (rt_uint8)c;
}

/*@}*/