x86: mrst: Add vrtc driver which serves as a wall clock device

Moorestown platform doesn't have a m146818 RTC device like traditional
x86 PC, but a firmware emulated virtual RTC device(vrtc), which provides
some basic RTC functions like get/set time. vrtc serves as the only
wall clock device on Moorestown platform.

[ tglx: Changed the exports to _GPL ]

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>
LKML-Reference: <20101110172837.3311.40483.stgit@localhost.localdomain>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/include/asm/mrst-vrtc.h

@@ -0,0 +1,9 @@
+#ifndef _MRST_VRTC_H
+#define _MRST_VRTC_H
+
+extern unsigned char vrtc_cmos_read(unsigned char reg);
+extern void vrtc_cmos_write(unsigned char val, unsigned char reg);
+extern unsigned long vrtc_get_time(void);
+extern int vrtc_set_mmss(unsigned long nowtime);
+
+#endif