-extern int dn_request_irq(unsigned int irq, irqreturn_t (*handler)(int, void *, struct pt_regs *), unsigned long flags, const char *devname, void *dev_id);
-extern void dn_free_irq(unsigned int irq, void *dev_id);
-extern void dn_enable_irq(unsigned int);
-extern void dn_disable_irq(unsigned int);
-extern int show_dn_interrupts(struct seq_file *, void *);