alpha: Convert alpha to use read/update_persistent_clock

This patch converts the alpha architecture to use the generic
read_persistent_clock and update_persistent_clock interfaces, reducing
the amount of arch specific code we have to maintain, and allowing for
further cleanups in the future.

I have not built or tested this patch, so help from arch maintainers
would be appreciated.

igned-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <1267675049-12337-2-git-send-email-johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

2 files changed, 50 insertions, 54 deletions

diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index bd7261ea8f94..75fff7e5a0db 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -54,6 +54,9 @@ config ARCH_USES_GETTIMEOFFSET
         bool
         default y
 
+config GENERIC_CMOS_UPDATE
+        def_bool y
+
 config ZONE_DMA
         bool
         default y
diff --git a/arch/alpha/kernel/time.c b/arch/alpha/kernel/time.c
index 5d0826654c61..5465e932e568 100644
--- a/arch/alpha/kernel/time.c
+++ b/arch/alpha/kernel/time.c
@@ -75,8 +75,6 @@ static struct {
         __u32 last_time;
         /* ticks/cycle * 2^48 */
         unsigned long scaled_ticks_per_cycle;
-        /* last time the CMOS clock got updated */
-        time_t last_rtc_update;
         /* partial unused tick */
         unsigned long partial_tick;
 } state;
@@ -91,6 +89,52 @@ static inline __u32 rpcc(void)
     return result;
 }
 
+int update_persistent_clock(struct timespec now)
+{
+        return set_rtc_mmss(now.tv_sec);
+}
+
+void read_persistent_clock(struct timespec *ts)
+{
+        unsigned int year, mon, day, hour, min, sec, epoch;
+
+        sec = CMOS_READ(RTC_SECONDS);
+        min = CMOS_READ(RTC_MINUTES);
+        hour = CMOS_READ(RTC_HOURS);
+        day = CMOS_READ(RTC_DAY_OF_MONTH);
+        mon = CMOS_READ(RTC_MONTH);
+        year = CMOS_READ(RTC_YEAR);
+
+        if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
+                sec = bcd2bin(sec);
+                min = bcd2bin(min);
+                hour = bcd2bin(hour);
+                day = bcd2bin(day);
+                mon = bcd2bin(mon);
+                year = bcd2bin(year);
+        }
+
+        /* PC-like is standard; used for year >= 70 */
+        epoch = 1900;
+        if (year < 20)
+                epoch = 2000;
+        else if (year >= 20 && year < 48)
+                /* NT epoch */
+                epoch = 1980;
+        else if (year >= 48 && year < 70)
+                /* Digital UNIX epoch */
+                epoch = 1952;
+
+        printk(KERN_INFO "Using epoch = %d\n", epoch);
+
+        if ((year += epoch) < 1970)
+                year += 100;
+
+        ts->tv_sec = mktime(year, mon, day, hour, min, sec);
+}
+
+
+
 /*
  * timer_interrupt() needs to keep up the real-time clock,
  * as well as call the "do_timer()" routine every clocktick
@@ -123,19 +167,6 @@ irqreturn_t timer_interrupt(int irq, void *dev)
         if (nticks)
                 do_timer(nticks);
 
-        /*
-         * If we have an externally synchronized Linux clock, then update
-         * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
-         * called as close as possible to 500 ms before the new second starts.
-         */
-        if (ntp_synced()
-            && xtime.tv_sec > state.last_rtc_update + 660
-            && xtime.tv_nsec >= 500000 - ((unsigned) TICK_SIZE) / 2
-            && xtime.tv_nsec <= 500000 + ((unsigned) TICK_SIZE) / 2) {
-                int tmp = set_rtc_mmss(xtime.tv_sec);
-                state.last_rtc_update = xtime.tv_sec - (tmp ? 600 : 0);
-        }
-
         write_sequnlock(&xtime_lock);
 
 #ifndef CONFIG_SMP
@@ -304,7 +335,7 @@ rpcc_after_update_in_progress(void)
 void __init
 time_init(void)
 {
-        unsigned int year, mon, day, hour, min, sec, cc1, cc2, epoch;
+        unsigned int cc1, cc2;
         unsigned long cycle_freq, tolerance;
         long diff;
 
@@ -348,43 +379,6 @@ time_init(void)
            bogomips yet, but this is close on a 500Mhz box.  */
         __delay(1000000);
 
-        sec = CMOS_READ(RTC_SECONDS);
-        min = CMOS_READ(RTC_MINUTES);
-        hour = CMOS_READ(RTC_HOURS);
-        day = CMOS_READ(RTC_DAY_OF_MONTH);
-        mon = CMOS_READ(RTC_MONTH);
-        year = CMOS_READ(RTC_YEAR);
-
-        if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
-                sec = bcd2bin(sec);
-                min = bcd2bin(min);
-                hour = bcd2bin(hour);
-                day = bcd2bin(day);
-                mon = bcd2bin(mon);
-                year = bcd2bin(year);
-        }
-
-        /* PC-like is standard; used for year >= 70 */
-        epoch = 1900;
-        if (year < 20)
-                epoch = 2000;
-        else if (year >= 20 && year < 48)
-                /* NT epoch */
-                epoch = 1980;
-        else if (year >= 48 && year < 70)
-                /* Digital UNIX epoch */
-                epoch = 1952;
-
-        printk(KERN_INFO "Using epoch = %d\n", epoch);
-
-        if ((year += epoch) < 1970)
-                year += 100;
-
-        xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
-        xtime.tv_nsec = 0;
-
-        wall_to_monotonic.tv_sec -= xtime.tv_sec;
-        wall_to_monotonic.tv_nsec = 0;
 
         if (HZ > (1<<16)) {
                 extern void __you_loose (void);
@@ -394,7 +388,6 @@ time_init(void)
         state.last_time = cc1;
         state.scaled_ticks_per_cycle
                 = ((unsigned long) HZ << FIX_SHIFT) / cycle_freq;
-        state.last_rtc_update = 0;
         state.partial_tick = 0L;
 
         /* Startup the timer source. */