diff --git a/include/linux/irq.h b/include/linux/irq.h
index 5e7c6ee..ce8171b 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -101,6 +101,9 @@
  * @set_type:		set the flow type (IRQ_TYPE_LEVEL/etc.) of an IRQ
  * @set_wake:		enable/disable power-management wake-on of an IRQ
  *
+ * @bus_lock:		function to lock access to slow bus (i2c) chips
+ * @bus_sync_unlock:	function to sync and unlock slow bus (i2c) chips
+ *
  * @release:		release function solely used by UML
  * @typename:		obsoleted by name, kept as migration helper
  */
@@ -124,6 +127,9 @@
 	int		(*set_type)(unsigned int irq, unsigned int flow_type);
 	int		(*set_wake)(unsigned int irq, unsigned int on);
 
+	void		(*bus_lock)(unsigned int irq);
+	void		(*bus_sync_unlock)(unsigned int irq);
+
 	/* Currently used only by UML, might disappear one day.*/
 #ifdef CONFIG_IRQ_RELEASE_METHOD
 	void		(*release)(unsigned int irq, void *dev_id);