Kontron KTAM3874-pITX - Manual (Page 70)

KTD-S0057-I Page 66 Linux® Programming Examples (DebianTM)
KTAM3874/pITX Software Guide
else
{
printf ("\nCannot open GPIO !\n");
gpio_unexport (GP2_17);
return -1;
}
gpio_unexport (GP2_17);
}
else
{
printf ("\nGPIO init error !\n");
gpio_unexport (GP2_17);
return -1;
}
printf ("\n");
return 0;
}
You can add interrupt support with a simple extension (only an extract):
#include <poll.h>
#define IRQ_FALL 0
#define IRQ_RISE 1
#define EDGE_RISE "rising"
#define EDGE_FALL "falling"
#define POLL_TIMEOUT 20000
static const char *dev_edge = "/sys/class/gpio/gpio%d/edge";
int gpio_set_edge (int gpio_pin, int rise_fall)
{
int
fd_tmp;
char str[128];
sprintf (str, dev_edge, gpio_pin);
fd_tmp = open (str, O_WRONLY);
if (fd_tmp < 0)
return -1;
if (rise_fall)
{
if (write (fd_tmp, EDGE_RISE, sizeof(EDGE_RISE)-1) != sizeof(EDGE_RISE)-1)
{
close (fd_tmp);
return -1;
}
}