seg7_driver.c

嵌入式开发试验：七段数码管实验

/*
 *	seg7_driver.c - seg7 driver ( low-level )
 *	
 *	Author: 	li ming <[e-mail]>
 *	Date:		2005-6-11
 *	Copyleft:	http://www.lumit.org
 */

#include "seg7_driver.h"

/* set seg7 related gpio */
int seg7_open( void )
{
	// do nothing
	return 0;
}

int seg7_read( char * buf, int count )
{	
	// do nothing	
	return count;
}

int seg7_write( char * buf, int count )
{	
	int i = 0;
	int seg7_value = 0;
	
	// the count has exceeds the count of seg7
	if( count > SEG7_NUM )
		return -1;
	
	for( i = 0; i < count; i++ )
		seg7_value = seg7_value | (buf[i]? ( 1 << i ) : 0) ;
	
	// write the value to 7 segment leds
	SEG7 = seg7_value;
	
	return count;
}

int seg7_ioctl( unsigned int cmd, unsigned long arg )
{
	// do nothing 	
	return 0;
}

int seg7_release( void )
{
	// do nothing 
	return 0;	
}