RTC: Add rtc-omap

This creates a new RTC-framework driver for the RTC/calendar module
found in various OMAP chips, giving a more correct/standard replacement
for the older drivers/char/omap-rtc.c driver.  Differences include:

 - much smaller/simpler, because it reuses shared infrastructure
 - the RTC name will normally be "rtc0" not "rtc"
 - the /dev node has a different major and minor numbers
 - RTC_ALM_SET handled as on PCs (alarm within 24 hours)
 - RTC_WKALM_SET handled as on PCs (alarm within this century)
 - epoch not changeable (why bother)
 - rtc alarm may optionally be a system wakeup event (board-specific)

If you use udev and statically link this, some init script can just create
a symbolic link (rtc -> rtc0) so tools like "hwclock" will work as usual.
Or, updates to hwclock (and busybox) are available which teach it to use
the /dev/rtc0 path as a backup, and to support "hwclock --file=/dev/rtc0".
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>

arch/arm/mach-omap1/devices.c

@@ -26,7 +26,7 @@
 
 /*-------------------------------------------------------------------------*/
 
-#if	defined(CONFIG_OMAP_RTC) || defined(CONFIG_OMAP_RTC)
+#if defined(CONFIG_OMAP_RTC) || defined(CONFIG_RTC_DRV_OMAP) || defined(CONFIG_RTC_DRV_OMAP_MODULE)
 
 #define	OMAP_RTC_BASE		0xfffb4800
 

drivers/rtc/Kconfig

@@ -151,6 +151,14 @@ config RTC_DRV_DS1742
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-ds1742.
 
+config RTC_DRV_OMAP
+	tristate "TI OMAP1"
+	depends on RTC_CLASS && ( \
+		ARCH_OMAP15XX || ARCH_OMAP16XX || ARCH_OMAP730 )
+	help
+	  Say "yes" here to support the real time clock on TI OMAP1 chips.
+	  This driver can also be built as a module called rtc-omap.
+
 config RTC_DRV_PCF8563
 	tristate "Philips PCF8563/Epson RTC8564"
 	depends on RTC_CLASS && I2C

drivers/rtc/Makefile

@@ -17,6 +17,7 @@ obj-$(CONFIG_RTC_DRV_TEST)	+= rtc-test.o
 obj-$(CONFIG_RTC_DRV_DS1307)	+= rtc-ds1307.o
 obj-$(CONFIG_RTC_DRV_DS1672)	+= rtc-ds1672.o
 obj-$(CONFIG_RTC_DRV_DS1742)	+= rtc-ds1742.o
+obj-$(CONFIG_RTC_DRV_OMAP)	+= rtc-omap.o
 obj-$(CONFIG_RTC_DRV_PCF8563)	+= rtc-pcf8563.o
 obj-$(CONFIG_RTC_DRV_PCF8583)	+= rtc-pcf8583.o
 obj-$(CONFIG_RTC_DRV_RS5C372)	+= rtc-rs5c372.o