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authorLinus Torvalds <torvalds@linux-foundation.org>2013-02-19 19:05:45 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-02-19 19:05:45 -0800
commit266d7ad7f4fe2f44b91561f5b812115c1b3018ab (patch)
tree45acf12d5cb170205ccffe24b9f24672ff8bff2e /drivers/rtc
parentbcbd818c069b9e1bf82517401225b152a33968e2 (diff)
parent36dfbbf136db0d645bacfd42ce7d9d6928ea532d (diff)
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Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer changes from Ingo Molnar: "Main changes: - ntp: Add CONFIG_RTC_SYSTOHC: a generic RTC driver facility complementing the existing CONFIG_RTC_HCTOSYS, which uses NTP to keep the hardware clock updated. - posix-timers: Fix clock_adjtime to always return timex data on success. This is changing the ABI, but no breakage was expected and found - caution is warranted nevertheless. - platform persistent clock improvements/cleanups. - clockevents: refactor timer broadcast handling to be more generic and less duplicated with matching architecture code (mostly ARM motivated.) - various fixes and cleanups" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timers/x86/hpet: Use HPET_COUNTER to specify the hpet counter in vread_hpet() posix-cpu-timers: Fix nanosleep task_struct leak clockevents: Fix generic broadcast for FEAT_C3STOP time, Fix setting of hardware clock in NTP code hrtimer: Prevent hrtimer_enqueue_reprogram race clockevents: Add generic timer broadcast function clockevents: Add generic timer broadcast receiver timekeeping: Switch HAS_PERSISTENT_CLOCK to ALWAYS_USE_PERSISTENT_CLOCK x86/time/rtc: Don't print extended CMOS year when reading RTC x86: Select HAS_PERSISTENT_CLOCK on x86 timekeeping: Add CONFIG_HAS_PERSISTENT_CLOCK option rtc: Skip the suspend/resume handling if persistent clock exist timekeeping: Add persistent_clock_exist flag posix-timers: Fix clock_adjtime to always return timex data on success Round the calculated scale factor in set_cyc2ns_scale() NTP: Add a CONFIG_RTC_SYSTOHC configuration MAINTAINERS: Update John Stultz's email time: create __getnstimeofday for WARNless calls
Diffstat (limited to 'drivers/rtc')
-rw-r--r--drivers/rtc/Kconfig12
-rw-r--r--drivers/rtc/Makefile1
-rw-r--r--drivers/rtc/class.c7
-rw-r--r--drivers/rtc/systohc.c44
4 files changed, 63 insertions, 1 deletions
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 923a9da..5e44eaa 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -20,14 +20,24 @@ if RTC_CLASS
config RTC_HCTOSYS
bool "Set system time from RTC on startup and resume"
default y
+ depends on !ALWAYS_USE_PERSISTENT_CLOCK
help
If you say yes here, the system time (wall clock) will be set using
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
+ depends on !ALWAYS_USE_PERSISTENT_CLOCK
+ 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 4418ef3..ec2988b 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/class.c b/drivers/rtc/class.c
index 5143629..26388f1 100644
--- a/drivers/rtc/class.c
+++ b/drivers/rtc/class.c
@@ -50,6 +50,10 @@ static int rtc_suspend(struct device *dev, pm_message_t mesg)
struct rtc_device *rtc = to_rtc_device(dev);
struct rtc_time tm;
struct timespec delta, delta_delta;
+
+ if (has_persistent_clock())
+ return 0;
+
if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0)
return 0;
@@ -88,6 +92,9 @@ static int rtc_resume(struct device *dev)
struct timespec new_system, new_rtc;
struct timespec sleep_time;
+ if (has_persistent_clock())
+ return 0;
+
rtc_hctosys_ret = -ENODEV;
if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0)
return 0;
diff --git a/drivers/rtc/systohc.c b/drivers/rtc/systohc.c
new file mode 100644
index 0000000..bf3e242
--- /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;
+}