OUTPUT_ARCH(arm)
ENTRY(_start)
SECTIONS
{
    . = 0x00000000;
    . = ALIGN(4);
    .text : { *(.text) }
    .data : { *(.data) }
    .bss  : { *(.bss) }
}

    gpio_map();
    gpio_output(0,4);
    
    while(1)
    {
    GPIO_WRITE_PIN(4,1);
    sleep(1);
    GPIO_WRITE_PIN(4,0);
    sleep(1);
    
    }

    gpio_map();
    gpio_output(1,32);
    
    while(1)
    {
    GPIO_WRITE_PIN(32,1);
    sleep(1);
    GPIO_WRITE_PIN(32,0);
    sleep(1);
    
    }

#define     SIZENAM                  255

enum pinstatus {PIN_OFF,PIN_ON};
enum pindirection{PIN_IN,PIN_OUT};

int gpioexp(int pin_num,pindirection pd,pinstatus st);
int gpioini();
int gpioset(int pin_num,pinstatus ps);
pinstatus gpioget(int pin_num);

#include <stdio.h> /* For printf() */
#include <string.h> /* For strerror() */
#include <unistd.h> /* For read(), close() */
#include <fcntl.h> /* For open() */
#include <errno.h> /* For errno */
#include <sys/poll.h> /* For poll() */
#include <time.h>
#include <stdlib.h>
#include "gpio.h"


/*-------------------------------------------------------------------------------------------------------*/
int gpioexp(int pin_num,pindirection pd,pinstatus st){
FILE * fp = NULL;
char gpio_file_name[SIZENAM];
if ((fp = fopen("/sys/class/gpio/export", "ab")) != NULL)
{
rewind(fp);
fprintf(fp,"%d",pin_num);
fclose(fp);

}else{
printf("Cannot open GPIO value for %s\n","/sys/class/gpio/export");
return -1;
}

memset(gpio_file_name,0,SIZENAM);
sprintf(gpio_file_name,"/sys/class/gpio/gpio%d/direction",pin_num);
if ((fp = fopen(gpio_file_name, "rb+")) != NULL)
{
rewind(fp);
switch(pd){
case PIN_IN:{
fprintf(fp,"in");
break;
}//case
case PIN_OUT:{
fprintf(fp,"out");
break;
}//case
default:break;
}//switch
fclose(fp);
if(pd!= PIN_IN){

memset(gpio_file_name,0,SIZENAM);
sprintf(gpio_file_name,"/sys/class/gpio/gpio%d/value",pin_num);
if ((fp = fopen(gpio_file_name, "rb+")) != NULL)
{
switch(st){
case PIN_ON:{
fprintf(fp,"1");
break;
}//case
case PIN_OFF:{
fprintf(fp,"0");
break;
}//case
default:break;
}//switch
fclose(fp);
}
}

}
return 0;
}
/*-------------------------------------------------------------------------------------------------------*/
int gpioini(){
/* pin out */
gpioexp(32,PIN_OUT,PIN_OFF);
gpioexp(39,PIN_OUT,PIN_OFF);

/* pin in */
gpioexp(23,PIN_IN,PIN_OFF);

return 0;
}
/*-------------------------------------------------------------------------------------------------------*/
int gpioset(int pin_num,pinstatus ps){
FILE * fp = NULL;
char gpio_file_name[SIZENAM];

memset(gpio_file_name,0,SIZENAM);
sprintf(gpio_file_name,"/sys/class/gpio/gpio%d/value",pin_num);
if ((fp = fopen(gpio_file_name, "rb+")) != NULL)
{
switch(ps){
case PIN_ON:{
fprintf(fp,"1");
break;
}//case
case PIN_OFF:{
fprintf(fp,"0");
break;
}//case
default:break;
}//switch

fclose(fp);
}
return 0;
}
/*-------------------------------------------------------------------------------------------------------*/
pinstatus gpioget(int pin_num){
FILE * fp = NULL;
char gpio_file_name[SIZENAM];
long lSize;
char * buffer;
size_t result;
int temm =0;
pinstatus ret = PIN_OFF;

memset(gpio_file_name,0,SIZENAM);
sprintf(gpio_file_name,"/sys/class/gpio/gpio%d/value",pin_num);
if ((fp = fopen(gpio_file_name, "rb+")) != NULL)
{
fseek (fp , 0 , SEEK_END);
lSize = ftell (fp);
rewind (fp);

buffer = (char*) malloc (sizeof(char)*lSize);
if (buffer == NULL) {
printf("Memory error");
}else{

result = fread (buffer,1,lSize,fp);
temm = atoi(buffer);

switch(temm){
case 0:{
ret = PIN_OFF;;
break;
}//case
case 1:{
ret = PIN_ON;
break;
}//case
default:break;
}//switch


}
free (buffer);
fclose(fp);
}
return ret;
}
/*-------------------------------------------------------------------------------------------------------*/