timer_driver.c

ARM9系列,s3c2410实验代码

/*
 *	timer_driver.c - timer_0 driver ( low-level )
 *	
 *	Author: 	li ming <[e-mail]>
 *	Date:		2005-6-12
 *	Copyleft:	http://www.lumit.org
 */

#include "timer_driver.h"
#include "led_api.h"

/* set timer related gpio */
int timer_open( void )
{	
	// disable timer_0
	TMOD = 0;	

	// Clear pending interrupts
	INTPND = 0x00000000; 	

	// enable timer 0
   	TMOD = 1;

	return 0;
}

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

int timer_write( char * buf, int count )
{	
	
	return count;
}

int timer_ioctl( unsigned int cmd, unsigned long arg )
{
	switch( cmd )
	{
		// set interrupt counter
		case	TIMER_SET_COUNTER:
			TDATA0 = *(unsigned int *)arg; 
			break;
	
		// Enable interrupt request and Unmask timer_0 interrupt
		case	TIMER_ENABLE_INTERRUPT:		
			INTMSK &= ~((1 << 21) | (1 <<10) );
			break;

		// clear timer 0 pending interrupts
		case	TIMER_CLEAR_INTERRUPT:
			INTPND |= 1 << 10;
					
		default:
			break;
	}	
	// do nothing 	
	return 0;
}

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