--- /dev/null
+From 76fc6d798113bb5d3c8499f8d61a9f74df10bdb0 Mon Sep 17 00:00:00 2001
+From: David Fries <David@Fries.net>
+Date: Sat, 25 Aug 2012 13:48:08 -0500
+Subject: [PATCH] update system time after N900 resumes
+
+enable with,
+CONFIG_RTC_HCTOSYS=m
+CONFIG_RTC_HCTOSYS_DEVICE="rtc0"
+
+Currently nothing updates the system clock after a suspend to memory
+operation, and date shows that almost no time elapsed.
+As ARM doesn't have a specific read_persistent_clock the default
+returns 0. The RTC rtc_suspend/rtc_resume will set the clock after
+resume, but requires CONFIG_RTC_HCTOSYS_DEVICE to be set, but that
+requires RTC to be compiled into the kernel.
+
+This splits up the configuration for setting the system time on bootup
+from setting the time on resume. This allows RTC_CLASS to be compiled
+as a module if the system needs the RTC for resume, but not for boot,
+which is the case for the N900.
+
+Note, v3.0-rc1 removed the support for compiling RTC_CLASS as a
+module, so this change isn't releavant upstream. One option is to
+compile RTC into the kernel and enable RTC_HCTOSYS, I just see this as
+the smaller change.
+
+Signed-off-by: David Fries <David@Fries.net>
+---
+ arch/arm/configs/rx51_defconfig | 2 ++
+ drivers/rtc/Kconfig | 39 ++++++++++++++++++++++++---------------
+ drivers/rtc/Makefile | 2 +-
+ 3 files changed, 27 insertions(+), 16 deletions(-)
+
+diff --git a/arch/arm/configs/rx51_defconfig b/arch/arm/configs/rx51_defconfig
+index d09af85..b61769b 100644
+--- a/arch/arm/configs/rx51_defconfig
++++ b/arch/arm/configs/rx51_defconfig
+@@ -1885,6 +1885,8 @@ CONFIG_LEDS_TRIGGER_HEARTBEAT=y
+ CONFIG_LEDS_TRIGGER_KEYB=y
+ CONFIG_RTC_LIB=y
+ CONFIG_RTC_CLASS=m
++CONFIG_RTC_HCTOSYS=m
++CONFIG_RTC_HCTOSYS_DEVICE="rtc0"
+
+ #
+ # RTC interfaces
+diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
+index 123092d..738ae0a 100644
+--- a/drivers/rtc/Kconfig
++++ b/drivers/rtc/Kconfig
+@@ -21,27 +21,24 @@ menuconfig RTC_CLASS
+ if RTC_CLASS
+
+ config RTC_HCTOSYS
+- bool "Set system time from RTC on startup and resume"
+- depends on RTC_CLASS = y
+- default y
++ tristate "Enable setting system time from RTC"
++ depends on RTC_CLASS
++ default RTC_CLASS
+ 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.
++ This enables RTC_HCTOSYS_DEVICE to set the RTC device used for
++ resume and optionally RTC_HCTOSYS_BOOT to also set the time on boot.
+
+ config RTC_HCTOSYS_DEVICE
+- string "RTC used to set the system time"
+- depends on RTC_HCTOSYS = y
++ string "RTC used to set the system time on startup or resume"
++ depends on RTC_HCTOSYS
+ default "rtc0"
+ help
+ The RTC device that will be used to (re)initialize the system
+ clock, usually rtc0. Initialization is done when the system
+- starts up, and when it resumes from a low power state. This
+- device should record time in UTC, since the kernel won't do
+- timezone correction.
+-
+- The driver for this RTC device must be loaded before late_initcall
+- functions run, so it must usually be statically linked.
++ starts up (if RTC_HCTOSYS is selected), and when it resumes from a
++ low power state. This device should record time in UTC, since the
++ kernel won't do timezone correction. The system clock is only
++ modified if the driver is loaded in resume (if compiled as a module).
+
+ This clock should be battery-backed, so that it reads the correct
+ time when the system boots from a power-off state. Otherwise, your
+@@ -49,9 +46,21 @@ config RTC_HCTOSYS_DEVICE
+
+ If the clock you specify here is not battery backed, it may still
+ be useful to reinitialize system time when resuming from system
+- sleep states. Do not specify an RTC here unless it stays powered
++ sleep states. Do not specify an RTC here unless it stays powered
+ during all this system's supported sleep states.
+
++config RTC_HCTOSYS_BOOT
++ bool "Set system time from RTC on startup"
++ depends on RTC_HCTOSYS = y
++ default y
++ 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.
++
++ The driver for the RTC_HCTOSYS_DEVICE must be loaded before
++ late_initcall functions run, so it must usually be statically linked.
++
+ config RTC_DEBUG
+ bool "RTC debug support"
+ depends on RTC_CLASS = y
+diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
+index 6e79c91..0a8ed8b 100644
+--- a/drivers/rtc/Makefile
++++ b/drivers/rtc/Makefile
+@@ -7,7 +7,7 @@ ifeq ($(CONFIG_RTC_DEBUG),y)
+ endif
+
+ obj-$(CONFIG_RTC_LIB) += rtc-lib.o
+-obj-$(CONFIG_RTC_HCTOSYS) += hctosys.o
++obj-$(CONFIG_RTC_HCTOSYS_BOOT) += hctosys.o
+ obj-$(CONFIG_RTC_CLASS) += rtc-core.o
+ rtc-core-y := class.o interface.o
+
+--
+1.7.10.4
+
projects / kernel-power / blobdiff