Those return either the corresponding number in the other namespace, or
else a negative errno code if the mapping can't be done. (For example,
some GPIOs can't used as IRQs.) It is an unchecked error to use a GPIO
Those return either the corresponding number in the other namespace, or
else a negative errno code if the mapping can't be done. (For example,
some GPIOs can't used as IRQs.) It is an unchecked error to use a GPIO