ARM: 7522/1: arch_timers: register a time/cycle counter

Some subsystems (KVM for example) need access to a cycle counter.
In the KVM case, this is used to measure the time delta between
host and guest in order to accurately generate timer events for
the guest.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/include/asm/arch_timer.h b/arch/arm/include/asm/arch_timer.h
index 62e7547..ad9b155 100644
--- a/arch/arm/include/asm/arch_timer.h
+++ b/arch/arm/include/asm/arch_timer.h
@@ -2,11 +2,13 @@
 #define __ASMARM_ARCH_TIMER_H
 
 #include <asm/errno.h>
+#include <linux/clocksource.h>
 
 #ifdef CONFIG_ARM_ARCH_TIMER
 #define ARCH_HAS_READ_CURRENT_TIMER
 int arch_timer_of_register(void);
 int arch_timer_sched_clock_init(void);
+struct timecounter *arch_timer_get_timecounter(void);
 #else
 static inline int arch_timer_of_register(void)
 {
@@ -17,6 +19,11 @@
 {
 	return -ENXIO;
 }
+
+static inline struct timecounter *arch_timer_get_timecounter(void)
+{
+	return NULL;
+}
 #endif
 
 #endif