diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index 573819ef..0d96cde 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -143,7 +143,7 @@
  *			400-499: Perfect
  *				The ideal clocksource. A must-use where
  *				available.
- * @read:		returns a cycle value
+ * @read:		returns a cycle value, passes clocksource as argument
  * @mask:		bitmask for two's complement
  *			subtraction of non 64 bit counters
  * @mult:		cycle to nanosecond multiplier (adjusted by NTP)
@@ -162,7 +162,7 @@
 	char *name;
 	struct list_head list;
 	int rating;
-	cycle_t (*read)(void);
+	cycle_t (*read)(struct clocksource *cs);
 	cycle_t mask;
 	u32 mult;
 	u32 mult_orig;
@@ -271,7 +271,7 @@
  */
 static inline cycle_t clocksource_read(struct clocksource *cs)
 {
-	return cs->read();
+	return cs->read(cs);
 }
 
 /**