Kontron KTAM3874-pITX - Manual (Page 67)

KTD-S0057-I Page 63 Linux® Programming Examples (DebianTM)
KTAM3874/pITX Software Guide
int gpio_unexport (int gpio_pin)
{
int
fd_tmp;
char str[8];
fd_tmp = open (dev_unexport, O_WRONLY);
if (fd_tmp < 0)
return -1;
sprintf (str, "%d", gpio_pin);
if (write (fd_tmp, str, strlen (str)) != strlen (str))
{
close (fd_tmp);
return -1;
}
close (fd_tmp);
return 0;
}
int gpio_set_direction (int gpio_pin, int out_in)
{
int
fd_tmp;
char str[128];
sprintf (str, dev_dir, gpio_pin);
fd_tmp = open (str, O_WRONLY);
if (fd_tmp < 0)
return -1;
if (out_in)
{
if (write (fd_tmp, DIR_OUT, sizeof(DIR_OUT)-1) != sizeof(DIR_OUT)-1)
{
close (fd_tmp);
return -1;
}
}
else
{
if (write (fd_tmp, DIR_IN, sizeof(DIR_IN)-1) != sizeof(DIR_IN)-1)
{
close (fd_tmp);
return -1;
}
}
close (fd_tmp);
return 0;
}