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| author | Xunlei Pang <pang.xunlei@linaro.org> | 2015-06-12 06:10:16 +0300 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@free-electrons.com> | 2015-06-25 02:13:42 +0300 |
| commit | 9c5150b31b49e3d89c52df9b1c1ebcea4e665ec3 (patch) | |
| tree | bba4dff4be684e676b1a148ea7eca8393cb39efb /drivers/rtc/Kconfig | |
| parent | 9033fd8ba7e96821e65fe3afc3f4077a8b66d1c9 (diff) | |
| download | linux-9c5150b31b49e3d89c52df9b1c1ebcea4e665ec3.tar.xz | |
rtc: NTP: Add CONFIG_RTC_SYSTOHC_DEVICE for NTP synchronization
Currently, CONFIG_RTC_SYSTOHC uses CONFIG_RTC_HCTOSYS_DEVICE which
is originally used by CONFIG_RTC_HCTOSYS, but this rtc device has
some limiations, for example, it must be battery-backed, be able
to work with irq off and through system suspension, etc.
So add CONFIG_RTC_SYSTOHC_DEVICE used exclusively for CONFIG_RTC_SYSTOHC,
it is more lenient compared to CONFIG_RTC_HCTOSYS_DEVICE, and could
be assigned any available RTC in the system.
Default value is CONFIG_RTC_HCTOSYS_DEVICE which is "rtc0" by default.
After this patch, NTP will sync up "rtc0" by default.
Cc: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Diffstat (limited to 'drivers/rtc/Kconfig')
| -rw-r--r-- | drivers/rtc/Kconfig | 29 |
1 files changed, 20 insertions, 9 deletions
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index c94bb6aded51..efaff368ee94 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -25,17 +25,9 @@ config RTC_HCTOSYS the value read from a specified RTC device. This is useful to avoid unnecessary fsck runs at boot time, and to network better. -config RTC_SYSTOHC - bool "Set the RTC time based on NTP synchronization" - default y - help - If you say yes here, the system time (wall clock) will be stored - in the RTC specified by RTC_HCTOSYS_DEVICE approximately every 11 - minutes if userspace reports synchronized NTP status. - config RTC_HCTOSYS_DEVICE string "RTC used to set the system time" - depends on RTC_HCTOSYS = y || RTC_SYSTOHC = y + depends on RTC_HCTOSYS default "rtc0" help The RTC device that will be used to (re)initialize the system @@ -56,6 +48,25 @@ config RTC_HCTOSYS_DEVICE sleep states. Do not specify an RTC here unless it stays powered during all this system's supported sleep states. +config RTC_SYSTOHC + bool "Set the RTC time based on NTP synchronization" + default y + help + If you say yes here, the system time (wall clock) will be stored + in the RTC specified by RTC_HCTOSYS_DEVICE approximately every 11 + minutes if userspace reports synchronized NTP status. + +config RTC_SYSTOHC_DEVICE + string "RTC used to synchronize NTP adjustment" + depends on RTC_SYSTOHC + default RTC_HCTOSYS_DEVICE if RTC_HCTOSYS + default "rtc0" + help + The RTC device used for NTP synchronization. The main difference + between RTC_HCTOSYS_DEVICE and RTC_SYSTOHC_DEVICE is that this + one can sleep when setting time, because it runs in the workqueue + context. + config RTC_DEBUG bool "RTC debug support" help |