rtc: max8997: add driver for max8997 rtc

Add an rtc driver for Maxim 8997 multifunction chip.  Max8997 has rtc
module in it.  and it can be used for timekeeping clock and system alarm.
It provide various operational mode those are BCD/binary, 24/12hour,
am/pm.  Driver sets binary/24/ for default.  Maxim 8997 also supports
SMPL(Sudden Momentary Power Loss), WTSR (Watchdog Timeout and Software
Reset).
Signed-off-by: Jonghwa Lee <jonghwa3.lee@samsung.com>
Cc: Devendra Naga <devendra.aaru@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/Kconfig

@@ -249,6 +249,16 @@ config RTC_DRV_MAX8998
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-max8998.
 
+config RTC_DRV_MAX8997
+	tristate "Maxim MAX8997"
+	depends on MFD_MAX8997
+	help
+	  If you say yes here you will get support for the
+	  RTC of Maxim MAX8997 PMIC.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called rtc-max8997.
+
 config RTC_DRV_MAX77686
 	tristate "Maxim MAX77686"
 	depends on MFD_MAX77686

drivers/rtc/Makefile

@@ -71,6 +71,7 @@ obj-$(CONFIG_RTC_DRV_MAX6900)	+= rtc-max6900.o
 obj-$(CONFIG_RTC_DRV_MAX8907)	+= rtc-max8907.o
 obj-$(CONFIG_RTC_DRV_MAX8925)	+= rtc-max8925.o
 obj-$(CONFIG_RTC_DRV_MAX8998)	+= rtc-max8998.o
+obj-$(CONFIG_RTC_DRV_MAX8997)	+= rtc-max8997.o
 obj-$(CONFIG_RTC_DRV_MAX6902)	+= rtc-max6902.o
 obj-$(CONFIG_RTC_DRV_MAX77686)	+= rtc-max77686.o
 obj-$(CONFIG_RTC_DRV_MC13XXX)	+= rtc-mc13xxx.o