mfd: rtc-twl4030 driver

This adds a driver for the RTC inside the TWL4030 multi-function device.
It's a fairly basic RTC, with a wake-capable alarm.

Note that many of the pre-release Overo boards now in circulation can't
effectively use this RTC, because of a wiring error that puts its TWL
chip into "secure" mode.  (As in "secure yourself against tampering".)
This isn't an issue on other OMAP3 boards now supported in mainline,
such as Beagle and Labrador.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Samuel Ortiz <sameo@openedhand.com>

drivers/rtc/Kconfig

@@ -246,6 +246,16 @@ config RTC_DRV_TWL92330
 	  platforms.  The support is integrated with the rest of
 	  the Menelaus driver; it's not separate module.
 
+config RTC_DRV_TWL4030
+	tristate "TI TWL4030/TWL5030/TPS659x0"
+	depends on RTC_CLASS && TWL4030_CORE
+	help
+	  If you say yes here you get support for the RTC on the
+	  TWL4030 family chips, used mostly with OMAP3 platforms.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called rtc-twl4030.
+
 config RTC_DRV_S35390A
 	tristate "Seiko Instruments S-35390A"
 	select BITREVERSE

drivers/rtc/Makefile

@@ -63,6 +63,7 @@ obj-$(CONFIG_RTC_DRV_SA1100)	+= rtc-sa1100.o
 obj-$(CONFIG_RTC_DRV_SH)	+= rtc-sh.o
 obj-$(CONFIG_RTC_DRV_STK17TA8)	+= rtc-stk17ta8.o
 obj-$(CONFIG_RTC_DRV_TEST)	+= rtc-test.o
+obj-$(CONFIG_RTC_DRV_TWL4030)	+= rtc-twl4030.o
 obj-$(CONFIG_RTC_DRV_V3020)	+= rtc-v3020.o
 obj-$(CONFIG_RTC_DRV_VR41XX)	+= rtc-vr41xx.o
 obj-$(CONFIG_RTC_DRV_X1205)	+= rtc-x1205.o