[ARM] Add save_time_delta()/restore_time_delta()

These two functions provide the infrastructure to manage time keeping
across a suspend/resume cycle.

diff --git a/arch/arm/kernel/time.c b/arch/arm/kernel/time.c
index c30bf05675eef2e74c0089af4433ef8b1674974f..3043e6de75d9919277fa2315725fb70b8629c6ff 100644 (file)
--- a/arch/arm/kernel/time.c
+++ b/arch/arm/kernel/time.c
@@ -304,6 +304,39 @@ int do_settimeofday(struct timespec *tv)
 
 EXPORT_SYMBOL(do_settimeofday);
 
+/**
+ * save_time_delta - Save the offset between system time and RTC time
+ * @delta: pointer to timespec to store delta
+ * @rtc: pointer to timespec for current RTC time
+ *
+ * Return a delta between the system time and the RTC time, such
+ * that system time can be restored later with restore_time_delta()
+ */
+void save_time_delta(struct timespec *delta, struct timespec *rtc)
+{
+       set_normalized_timespec(delta,
+                               xtime.tv_sec - rtc->tv_sec,
+                               xtime.tv_nsec - rtc->tv_nsec);
+}
+EXPORT_SYMBOL(save_time_delta);
+
+/**
+ * restore_time_delta - Restore the current system time
+ * @delta: delta returned by save_time_delta()
+ * @rtc: pointer to timespec for current RTC time
+ */
+void restore_time_delta(struct timespec *delta, struct timespec *rtc)
+{
+       struct timespec ts;
+
+       set_normalized_timespec(&ts,
+                               delta->tv_sec + rtc->tv_sec,
+                               delta->tv_nsec + rtc->tv_nsec);
+
+       do_settimeofday(&ts);
+}
+EXPORT_SYMBOL(restore_time_delta);
+
 void timer_tick(struct pt_regs *regs)
 {
        profile_tick(CPU_PROFILING, regs);

diff --git a/arch/arm/mach-pxa/pm.c b/arch/arm/mach-pxa/pm.c
index 6c5fecc095e1e55efa6d343af1d11f3477777e47..5e84864a8313c27da177c8f1043f293c1cf21812 100644 (file)
--- a/arch/arm/mach-pxa/pm.c
+++ b/arch/arm/mach-pxa/pm.c
@@ -21,6 +21,7 @@
 #include <asm/system.h>
 #include <asm/arch/pxa-regs.h>
 #include <asm/arch/lubbock.h>
+#include <asm/mach/time.h>
 
 
 /*
@@ -69,14 +70,16 @@ static int pxa_pm_enter(u32 state)
 {
        unsigned long sleep_save[SLEEP_SAVE_SIZE];
        unsigned long checksum = 0;
-       unsigned long delta;
+       struct timespec delta, rtc;
        int i;
 
        if (state != PM_SUSPEND_MEM)
                return -EINVAL;
 
        /* preserve current time */
-       delta = xtime.tv_sec - RCNR;
+       rtc.tv_sec = RCNR;
+       rtc.tv_nsec = 0;
+       save_time_delta(&delta, &rtc);
 
        /* save vital registers */
        SAVE(OSMR0);
@@ -161,7 +164,8 @@ static int pxa_pm_enter(u32 state)
        RESTORE(ICMR);
 
        /* restore current time */
-       xtime.tv_sec = RCNR + delta;
+       rtc.tv_sec = RCNR;
+       restore_time_delta(&delta, &rtc);
 
 #ifdef DEBUG
        printk(KERN_DEBUG "*** made it back from resume\n");

diff --git a/arch/arm/mach-sa1100/pm.c b/arch/arm/mach-sa1100/pm.c
index 604e703b522662510815c9787dada4f6149c1c74..7120ec5aa726c897187b5138596dbeb4d6e63425 100644 (file)
--- a/arch/arm/mach-sa1100/pm.c
+++ b/arch/arm/mach-sa1100/pm.c
@@ -30,6 +30,7 @@
 #include <asm/hardware.h>
 #include <asm/memory.h>
 #include <asm/system.h>
+#include <asm/mach/time.h>
 
 extern void sa1100_cpu_suspend(void);
 extern void sa1100_cpu_resume(void);
@@ -58,14 +59,16 @@ enum {      SLEEP_SAVE_SP = 0,
 
 static int sa11x0_pm_enter(u32 state)
 {
-       unsigned long sleep_save[SLEEP_SAVE_SIZE];
-       unsigned long delta, gpio;
+       unsigned long gpio, sleep_save[SLEEP_SAVE_SIZE];
+       struct timespec delta, rtc;
 
        if (state != PM_SUSPEND_MEM)
                return -EINVAL;
 
        /* preserve current time */
-       delta = xtime.tv_sec - RCNR;
+       rtc.tv_sec = RCNR;
+       rtc.tv_nsec = 0;
+       save_time_delta(&delta, &rtc);
        gpio = GPLR;
 
        /* save vital registers */
@@ -136,7 +139,8 @@ static int sa11x0_pm_enter(u32 state)
        OSCR = OSMR0 - LATCH;
 
        /* restore current time */
-       xtime.tv_sec = RCNR + delta;
+       rtc.tv_sec = RCNR;
+       restore_time_delta(&delta, &rtc);
 
        return 0;
 }

diff --git a/include/asm-arm/mach/time.h b/include/asm-arm/mach/time.h
index edb6fcc6a2005402b52fe8ae7d595fbfe4d73927..51728edf7ba4a94f5bcff615bfc319efa60173c5 100644 (file)
--- a/include/asm-arm/mach/time.h
+++ b/include/asm-arm/mach/time.h
@@ -13,8 +13,11 @@
 extern void (*init_arch_time)(void);
 
 extern int (*set_rtc)(void);
-extern unsigned long(*gettimeoffset)(void);
+extern unsigned long (*gettimeoffset)(void);
 
-void timer_tick(struct pt_regs *);
+extern void timer_tick(struct pt_regs *);
+
+extern void save_time_delta(struct timespec *delta, struct timespec *rtc);
+extern void restore_time_delta(struct timespec *delta, struct timespec *rtc);
 
 #endif