rtc: add alarm/update irq interfaces
Add standard interfaces for alarm/update irqs enabling. Drivers are no
more required to implement equivalent ioctl code as rtc-dev will provide
it.
UIE emulation should now be handled correctly and will work even for those
RTC drivers who cannot be configured to do both UIE and AIE.
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Cc: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 123092d..165a818 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -102,9 +102,13 @@
depends on RTC_INTF_DEV
help
Provides an emulation for RTC_UIE if the underlying rtc chip
- driver does not expose RTC_UIE ioctls. Those requests generate
+ driver does not expose RTC_UIE ioctls. Those requests generate
once-per-second update interrupts, used for synchronization.
+ The emulation code will read the time from the hardware
+ clock several times per second, please enable this option
+ only if you know that you really need it.
+
config RTC_DRV_TEST
tristate "Test driver/device"
help