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>

3 files changed, 5 insertions, 0 deletions

diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h
index 64642ad019fb..643ebf2e2ad8 100644
--- a/arch/x86/include/asm/x86_init.h
+++ b/arch/x86/include/asm/x86_init.h
@@ -83,11 +83,13 @@ struct x86_init_paging {
  *                              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);
 };
 
 /**
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 21c6746338af..68d535a77df0 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1059,6 +1059,8 @@ void __init setup_arch(char **cmdline_p)
 #endif
         x86_init.oem.banner();
 
+        x86_init.timers.wallclock_init();
+
         mcheck_init();
 
         local_irq_save(flags);
diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c
index ceb2911aa439..c11514e9128b 100644
--- a/arch/x86/kernel/x86_init.c
+++ b/arch/x86/kernel/x86_init.c
@@ -70,6 +70,7 @@ struct x86_init_ops x86_init __initdata = {
                 .setup_percpu_clockev   = setup_boot_APIC_clock,
                 .tsc_pre_init           = x86_init_noop,
                 .timer_init             = hpet_time_init,
+                .wallclock_init         = x86_init_noop,
         },
 
         .iommu = {