serial.c

s3c2440的LCD控制器驱动程序 ps 无操作系统的情况

//#include "serial.h"
#include "s3c2440.h"


#define SERIAL_CHAR_READY()     (UTRSTAT0 & UTRSTAT_RX_READY)
#define SERIAL_READ_CHAR()      URXH0
#define SERIAL_READ_STATUS()    (UERSTAT0 & UART_ERR_MASK)
#define SERIAL_WRITE_STATUS()	(UTRSTAT0)
#define SERIAL_WRITE_READY()	((UTRSTAT0) & UTRSTAT_TX_EMPTY)
#define SERIAL_WRITE_CHAR(c)	((UTXH0) = (c))


/*
 * Reads and returns a character from the serial port
 *   - Times out after delay iterations checking for presence of character
 *   - Sets *error_p to UART error bits or - on timeout
 *   - On timeout, sets *error_p to -1 and returns 0
 */
 
char  awaitkey( unsigned int timeout, int *statp)
{
	char c;
	int rxstat;
	int	do_timeout = (timeout != 0) ;


	while(!SERIAL_CHAR_READY()) {

		if (do_timeout) {
			if (!timeout)
				break;
			timeout--;
		}

	}

	if (do_timeout && timeout == 0) {
		c = 0;
		rxstat = -1;
	} else {
		c = SERIAL_READ_CHAR();
		rxstat = SERIAL_READ_STATUS();
	}

	if (rxstat) {
		if (statp)
			*statp = rxstat;
	}
	return (c);
}




char UART_getchar(void)
{
	char c;

	while (!SERIAL_CHAR_READY()) /* nothing */;

	c = SERIAL_READ_CHAR();

	return c;
}



char UART_getchar_with_display(void)
{
	char c;

	while (!SERIAL_CHAR_READY()) 
		;                                /* nothing */

	c = SERIAL_READ_CHAR();
	
	
	while (!SERIAL_WRITE_READY()) 
		;                               /* nothing */ 
	  
	SERIAL_WRITE_CHAR(c); 

	return c;
}




void UART_putchar(char c)
{
	while (!SERIAL_WRITE_READY()) /* nothing */; 
	  
	SERIAL_WRITE_CHAR(c); 
}





void UART_puts( const char * str )
{
	while( *str != '\0' )
		UART_putchar( *str++ );
}