I'm working on writing a module for the user button on the BeagleBoard-xM Rev C. For now, I'm just trying to print a message when the interrupt handler is called, i.e. when the user button is pressed.
The user button corresponds to GPIO pin 4. I'm performing a gpio_to_irq(4) to obtain the IRQ number which I'm passing to request_irq() with the handler, which is successful. In fact, this is my request_irq call.
irq_res = request_irq(4, interrupt_handler, IRQF_TRIGGER_FALLING, "Interrupt Test", NULL);
And my interrupt handler looks like this.
static irqreturn_t interrupt_handler(int, void*, struct pt_regs*);
But when the button is pressed, the interrupt handler is never called. Any pointers on how to debug this?
Thanks!