diff options
| -rw-r--r-- | arch/powerpc/kernel/time.c | 2 | ||||
| -rw-r--r-- | drivers/rtc/Kconfig | 10 | ||||
| -rw-r--r-- | drivers/rtc/Makefile | 1 | ||||
| -rw-r--r-- | drivers/rtc/systohc.c | 44 | ||||
| -rw-r--r-- | include/linux/rtc.h | 1 | ||||
| -rw-r--r-- | kernel/time/ntp.c | 16 |
6 files changed, 68 insertions, 6 deletions
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index ce4cb772dc78..bc844a857e05 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -667,7 +667,7 @@ int update_persistent_clock(struct timespec now) struct rtc_time tm; if (!ppc_md.set_rtc_time) - return 0; + return -ENODEV; to_tm(now.tv_sec + 1 + timezone_offset, &tm); tm.tm_year -= 1900; diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index 19c03ab2bdcb..b377e9672497 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -25,9 +25,17 @@ 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 + depends on RTC_HCTOSYS = y || RTC_SYSTOHC = y default "rtc0" help The RTC device that will be used to (re)initialize the system diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index 56297f0fd388..69d11f1d76e4 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -6,6 +6,7 @@ ccflags-$(CONFIG_RTC_DEBUG) := -DDEBUG obj-$(CONFIG_RTC_LIB) += rtc-lib.o obj-$(CONFIG_RTC_HCTOSYS) += hctosys.o +obj-$(CONFIG_RTC_SYSTOHC) += systohc.o obj-$(CONFIG_RTC_CLASS) += rtc-core.o rtc-core-y := class.o interface.o diff --git a/drivers/rtc/systohc.c b/drivers/rtc/systohc.c new file mode 100644 index 000000000000..bf3e242ccc5c --- /dev/null +++ b/drivers/rtc/systohc.c @@ -0,0 +1,44 @@ +/* + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + * + */ +#include <linux/rtc.h> +#include <linux/time.h> + +/** + * rtc_set_ntp_time - Save NTP synchronized time to the RTC + * @now: Current time of day + * + * Replacement for the NTP platform function update_persistent_clock + * that stores time for later retrieval by rtc_hctosys. + * + * Returns 0 on successful RTC update, -ENODEV if a RTC update is not + * possible at all, and various other -errno for specific temporary failure + * cases. + * + * If temporary failure is indicated the caller should try again 'soon' + */ +int rtc_set_ntp_time(struct timespec now) +{ + struct rtc_device *rtc; + struct rtc_time tm; + int err = -ENODEV; + + if (now.tv_nsec < (NSEC_PER_SEC >> 1)) + rtc_time_to_tm(now.tv_sec, &tm); + else + rtc_time_to_tm(now.tv_sec + 1, &tm); + + rtc = rtc_class_open(CONFIG_RTC_HCTOSYS_DEVICE); + if (rtc) { + /* rtc_hctosys exclusively uses UTC, so we call set_time here, + * not set_mmss. */ + if (rtc->ops && (rtc->ops->set_time || rtc->ops->set_mmss)) + err = rtc_set_time(rtc, &tm); + rtc_class_close(rtc); + } + + return err; +} diff --git a/include/linux/rtc.h b/include/linux/rtc.h index 9531845c419f..11d05f9fe8b6 100644 --- a/include/linux/rtc.h +++ b/include/linux/rtc.h @@ -138,6 +138,7 @@ extern void rtc_device_unregister(struct rtc_device *rtc); extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm); extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm); extern int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs); +extern int rtc_set_ntp_time(struct timespec now); int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm); extern int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alrm); diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index 24174b4d669b..313b161504b7 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -15,6 +15,7 @@ #include <linux/time.h> #include <linux/mm.h> #include <linux/module.h> +#include <linux/rtc.h> #include "tick-internal.h" @@ -483,8 +484,7 @@ out: return leap; } -#ifdef CONFIG_GENERIC_CMOS_UPDATE - +#if defined(CONFIG_GENERIC_CMOS_UPDATE) || defined(CONFIG_RTC_SYSTOHC) static void sync_cmos_clock(struct work_struct *work); static DECLARE_DELAYED_WORK(sync_cmos_work, sync_cmos_clock); @@ -510,14 +510,22 @@ static void sync_cmos_clock(struct work_struct *work) } getnstimeofday(&now); - if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec / 2) + if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec / 2) { + fail = -ENODEV; +#ifdef CONFIG_GENERIC_CMOS_UPDATE fail = update_persistent_clock(now); +#endif +#ifdef CONFIG_RTC_SYSTOHC + if (fail == -ENODEV) + fail = rtc_set_ntp_time(now); +#endif + } next.tv_nsec = (NSEC_PER_SEC / 2) - now.tv_nsec - (TICK_NSEC / 2); if (next.tv_nsec <= 0) next.tv_nsec += NSEC_PER_SEC; - if (!fail) + if (!fail || fail == -ENODEV) next.tv_sec = 659; else next.tv_sec = 0; |