typedef irqreturn_t (*irq_handler_t)(int, void *);
+/**
+ * struct irqaction - per interrupt action descriptor
+ * @handler: interrupt handler function
+ * @flags: flags (see IRQF_* above)
+ * @mask: no comment as it is useless and about to be removed
+ * @name: name of the device
+ * @dev_id: cookie to identify the device
+ * @next: pointer to the next irqaction for shared interrupts
+ * @irq: interrupt number
+ * @dir: pointer to the proc/irq/NN/name entry
+ */
struct irqaction {
irq_handler_t handler;
unsigned long flags;