path: root/drivers/rtc/Kconfig
diff options
authorJohn Stultz <john.stultz@linaro.org>2011-02-11 17:45:40 -0800
committerJohn Stultz <john.stultz@linaro.org>2011-02-17 14:59:41 -0800
commit6e57b1d6a8d8ed1998229b71c102be1997e397c6 (patch)
tree941ae7ba1c168af5603bb47d3bbfba33a8f2760c /drivers/rtc/Kconfig
parent516373b8b60fa4152334b6b6f2ece0f178c540ce (diff)
RTC: Revert UIE emulation removal
Uwe pointed out that my alarm based UIE emulation is not sufficient to replace the older timer/polling based UIE emulation on devices where there is no alarm irq. This causes rtc devices without alarms to return -EINVAL to UIE ioctls. The fix is to re-instate the old timer/polling method for devices without alarm irqs. This patch reverts the following commits: 042620a018afcfba1d678062b62e46 - Remove UIE emulation 1daeddd5962acad1bea55e524fc0fa - Cleanup removed UIE emulation declaration b5cc8ca1c9c3a37eaddf709b2fd3e1 - Remove Kconfig symbol for UIE emulation The emulation mode will still need to be wired-in with a following patch before it will work. CC: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> CC: Thomas Gleixner <tglx@linutronix.de> Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
Diffstat (limited to 'drivers/rtc/Kconfig')
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index cdd97192dc6..4941cade319 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -97,6 +97,18 @@ config RTC_INTF_DEV
If unsure, say Y.
+ bool "RTC UIE emulation on dev interface"
+ 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
+ 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.
tristate "Test driver/device"