x86/platform: Add a wallclock_init func to x86_init.timers ops

Some wall clock devices use MMIO based HW register, this new
function will give them a chance to do some initialization work
before their get/set_time service get called, which is usually
in early kernel boot phase.

Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h
index 64642ad..643ebf2 100644
--- a/arch/x86/include/asm/x86_init.h
+++ b/arch/x86/include/asm/x86_init.h
@@ -83,11 +83,13 @@
  *				boot cpu
  * @tsc_pre_init:		platform function called before TSC init
  * @timer_init:			initialize the platform timer (default PIT/HPET)
+ * @wallclock_init:		init the wallclock device
  */
 struct x86_init_timers {
 	void (*setup_percpu_clockev)(void);
 	void (*tsc_pre_init)(void);
 	void (*timer_init)(void);
+	void (*wallclock_init)(void);
 };
 
 /**