Registering an interrupt handler (1)

Defined in include/linux/interrupt.h

• int request_irq( Returns 0 if successful unsigned int irq, Requested irq channel irq_handler_t handler, Interrupt handler unsigned long irq_flags, Option mask (see next page) const char * devname, Registered name void *dev_id); Pointer to some handler data Cannot be NULL and must be unique for shared irqs!

• void free_irq( unsigned int irq, void *dev_id);

• dev_id cannot be NULL and must be unique for shared irqs. Otherwise, on a shared interrupt line, free_irq wouldn't know which handler to free.