#include <linux/mc146818rtc.h>
#include <linux/time.h>
#include <linux/timex.h>
+#include <linux/clocksource.h>
#include "proto.h"
#include "irq_impl.h"
__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;
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
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
return rpcc();
}
+#ifndef CONFIG_SMP
+/* Until and unless we figure out how to get cpu cycle counters
+ in sync and keep them there, we can't use the rpcc. */
+static cycle_t read_rpcc(struct clocksource *cs)
+{
+ cycle_t ret = (cycle_t)rpcc();
+ return ret;
+}
+
+static struct clocksource clocksource_rpcc = {
+ .name = "rpcc",
+ .rating = 300,
+ .read = read_rpcc,
+ .mask = CLOCKSOURCE_MASK(32),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS
+};
+
+static inline void register_rpcc_clocksource(long cycle_freq)
+{
+ clocksource_calc_mult_shift(&clocksource_rpcc, cycle_freq, 4);
+ clocksource_register(&clocksource_rpcc);
+}
+#else /* !CONFIG_SMP */
+static inline void register_rpcc_clocksource(long cycle_freq)
+{
+}
+#endif /* !CONFIG_SMP */
+
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;
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);
__you_loose();
}
+ register_rpcc_clocksource(cycle_freq);
+
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. */
}
/*
- * Use the cycle counter to estimate an displacement from the last time
- * tick. Unfortunately the Alpha designers made only the low 32-bits of
- * the cycle counter active, so we overflow on 8.2 seconds on a 500MHz
- * part. So we can't do the "find absolute time in terms of cycles" thing
- * that the other ports do.
- */
-u32 arch_gettimeoffset(void)
-{
-#ifdef CONFIG_SMP
- /* Until and unless we figure out how to get cpu cycle counters
- in sync and keep them there, we can't use the rpcc tricks. */
- return 0;
-#else
- unsigned long delta_cycles, delta_usec, partial_tick;
-
- delta_cycles = rpcc() - state.last_time;
- partial_tick = state.partial_tick;
- /*
- * usec = cycles * ticks_per_cycle * 2**48 * 1e6 / (2**48 * ticks)
- * = cycles * (s_t_p_c) * 1e6 / (2**48 * ticks)
- * = cycles * (s_t_p_c) * 15625 / (2**42 * ticks)
- *
- * which, given a 600MHz cycle and a 1024Hz tick, has a
- * dynamic range of about 1.7e17, which is less than the
- * 1.8e19 in an unsigned long, so we are safe from overflow.
- *
- * Round, but with .5 up always, since .5 to even is harder
- * with no clear gain.
- */
-
- delta_usec = (delta_cycles * state.scaled_ticks_per_cycle
- + partial_tick) * 15625;
- delta_usec = ((delta_usec / ((1UL << (FIX_SHIFT-6-1)) * HZ)) + 1) / 2;
- return delta_usec * 1000;
-#endif
-}
-
-/*
* In order to set the CMOS clock precisely, set_rtc_mmss has to be
* called 500 ms after the second nowtime has started, because when
* nowtime is written into the registers of the CMOS clock, it will
projects / linux-flexiantxendom0-3.2.10.git / blobdiff