From Documentation/gpio.txt
/* map GPIO numbers to IRQ numbers */
int gpio_to_irq(unsigned gpio);
/* map IRQ numbers to GPIO numbers */
int irq_to_gpio(unsigned irq);
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 be used as IRQs.) It is an unchecked error to use a GPIO
number that wasn't set up as an input using gpio_direction_input(), or
to use an IRQ number that didn't originally come from gpio_to_irq().
------------------------------------------------------------
Isn't an irq now an unsigned int? And the only possible error return
is NO_IRQ (ie 0).
--
Jon Smirl
jonsmirl@gmail.com
--
