[PATCH] RTC: rtc-dev UIE emulation

Import genrtc's RTC UIE emulation (CONFIG_GEN_RTC_X) to rtc-dev driver with
slight adjustments/refinements.  This makes UIE-less rtc drivers work
better with programs doing read/poll on /dev/rtc, such as hwclock.  This
emulation should not harm rtc drivers with UIE support, since
rtc_dev_ioctl() calls underlaying rtc driver's ioctl() first.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 9e24965..725d6b6 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -73,6 +73,13 @@
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-dev.
 
+config RTC_INTF_DEV_UIE_EMUL
+	bool "RTC UIE emulation on dev interface"
+	depends on RTC_INTF_DEV
+	help
+	  Provides an emulation for RTC_UIE if the underlaying rtc chip
+	  driver did not provide RTC_UIE ioctls.
+
 comment "RTC drivers"
 	depends on RTC_CLASS