ARM programming mini2440 Friendly ARM NEWBIE SIMPLE CODES

int main(int argc, char **argv)
{
	int on;
	int led_no;
	int fd;
	if (argc != 3 || sscanf(argv[1], "%d", &led_no) != 1 || sscanf(argv[2],"%d", &on) != 1 ||
	    on < 0 || on > 1 || led_no < 0 || led_no > 3) {
		fprintf(stderr, "Usage: leds led_no 0|1\n");
		exit(1);
	}
	fd = open("/dev/leds0", 0);
	if (fd < 0) {
		fd = open("/dev/leds", 0);
	}
	if (fd < 0) {
		perror("open device leds");
		exit(1);
	}
	ioctl(fd, on, led_no);
	close(fd);
	return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <signal.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/mman.h>
#include "/usr/local/include/s3c2410-regs.h"
#include "uart.h"

#define FATAL do { fprintf(stderr, "Error at line %d, file %s (%d) [%s]\n", \
  __LINE__, __FILE__, errno, strerror(errno)); exit(1); } while(0)

int running = 1;

void done (int sig)
{
    running = 0;
}


#define REQCNT 100              //May 08, 2002 SOP
#define ADC_FREQ 2500000
#define LOOP 10000
unsigned long led;
 int fd,fd1,fd2,fd3,led_no;

int main(int argc, char *argv[])
{

    signal (SIGINT, done);  // set up signal handler
    fd = open ("/dev/mem", O_RDWR | O_SYNC);

   GPIOp = mmap (0, sizeof (S3C2410_GPIO), PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0x56000000);

    printf ("\nThe Embedded Linux \n");

    GPIOp->GPBDAT=0x0000;

    while(1)
    {
    	printf ("\nSelect the LED(s) to glow :");
    	scanf("%d",&led_no);
    	printf ("\n");

    	switch(led_no)
    	{
    	case 1 :     GPIOp->GPBDAT=0x0020;
    			printf ("LED 1 \n");
    			break;

    	case 2 :     GPIOp->GPBDAT=0x0040;
			printf ("LED 2\n");
			break;

    	case 3 :     GPIOp->GPBDAT=0x0080;
			printf ("LED 3\n");
    			break;

    	case 4 :     GPIOp->GPBDAT=0x0100;
			printf ("LED 4\n");
    			break;

    	case 5 :     GPIOp->GPBDAT=~0x01E0;
			printf ("ALL LED ON\n");
    			break;

    	default  :    GPIOp->GPBDAT=~0x0000;
    			printf ("ALL LED OFF\n");
			break;
    	}

    }

    close (fd);

    if (munmap (GPIOp, sizeof (S3C2410_GPIO)) == -1){ }// FATAL;
    return 0;
}