119 lines
2.3 KiB
C
119 lines
2.3 KiB
C
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/*
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* File : serial.c
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* This file is part of RT-Thread RTOS
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* COPYRIGHT (C) 2006, RT-Thread Development Team
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*
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* The license and distribution terms for this file may be
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* found in the file LICENSE in this distribution or at
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* http://openlab.rt-thread.com/license/LICENSE
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*
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* Change Logs:
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* Date Author Notes
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* 2006-09-06 XuXinming first version
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* 2006-09-20 Bernard clean code according code style
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*/
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#include <rtthread.h>
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#include <rthw.h>
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#include "s3c44b0.h"
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void rt_serial_init(void);
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void rt_console_puts(const char* str);
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void rt_serial_putc(const char c);
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#define USTAT_RCV_READY 0x01 /* receive data ready */
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#define USTAT_TXB_EMPTY 0x02 /* tx buffer empty */
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rt_inline void serial_flush_input(void)
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{
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volatile unsigned int tmp;
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/* keep on reading as long as the receiver is not empty */
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while(UTRSTAT0 & USTAT_RCV_READY) tmp = URXH0;
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}
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rt_inline void serial_flush_output(void)
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{
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/* wait until the transmitter is no longer busy */
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while(!(UTRSTAT0 & USTAT_TXB_EMPTY)) ;
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}
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/**
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* @addtogroup S3C44B0
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*/
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/*@{*/
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/**
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* This function is used to display a string on console, normally, it's
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* invoked by rt_kprintf
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*
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* @param str the displayed string
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*/
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void rt_console_puts(const char* str)
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{
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while (*str)
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{
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rt_serial_putc (*str++);
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}
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}
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/**
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* This function initializes serial
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*/
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void rt_serial_init()
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{
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rt_uint32_t divisor = 0;
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divisor = 0x20;
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serial_flush_output();
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serial_flush_input();
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/* UART interrupt off */
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UCON0 = 0;
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/* FIFO disable */
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UFCON0 =0x0;
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UMCON0 =0x0;
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/* set baudrate */
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UBRDIV0 = divisor;
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/* word length=8bit, stop bit = 1, no parity, use external clock */
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ULCON0 = 0x03|0x00|0x00;
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UCON0 = 0x5;
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}
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/**
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* This function read a character from serial without interrupt enable mode
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*
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* @return the read char
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*/
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char rt_serial_getc()
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{
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while ((UTRSTAT0 & USTAT_RCV_READY) == 0);
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return URXH0;
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}
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/**
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* This function will write a character to serial without interrupt enable mode
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*
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* @param c the char to write
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*/
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void rt_serial_putc(const char c)
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{
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/*
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to be polite with serial console add a line feed
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to the carriage return character
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*/
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if (c=='\n')rt_serial_putc('\r');
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/* wait for room in the transmit FIFO */
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while(!(UTRSTAT0 & USTAT_TXB_EMPTY));
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UTXH0 = (rt_uint8_t)c;
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}
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/*@}*/
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