int gpio_direction_input(unsigned gpio);
int gpio_direction_output(unsigned gpio, int value);
-The return value is zero for success, else a negative errno. It must
+The return value is zero for success, else a negative errno. It should
be checked, since the get/set calls don't have error returns and since
misconfiguration is possible. You should normally issue these calls from
a task context. However, for spinlock-safe GPIOs it's OK to use them