diff options
Diffstat (limited to 'arch/xtensa/kernel/time.c')
| -rw-r--r-- | arch/xtensa/kernel/time.c | 131 |
1 files changed, 26 insertions, 105 deletions
diff --git a/arch/xtensa/kernel/time.c b/arch/xtensa/kernel/time.c index 8df1e842f6d..8848120d291 100644 --- a/arch/xtensa/kernel/time.c +++ b/arch/xtensa/kernel/time.c @@ -14,7 +14,7 @@ #include <linux/errno.h> #include <linux/time.h> -#include <linux/timex.h> +#include <linux/clocksource.h> #include <linux/interrupt.h> #include <linux/module.h> #include <linux/init.h> @@ -25,27 +25,31 @@ #include <asm/timex.h> #include <asm/platform.h> - -DEFINE_SPINLOCK(rtc_lock); -EXPORT_SYMBOL(rtc_lock); - - #ifdef CONFIG_XTENSA_CALIBRATE_CCOUNT unsigned long ccount_per_jiffy; /* per 1/HZ */ unsigned long nsec_per_ccount; /* nsec per ccount increment */ #endif -static long last_rtc_update = 0; - -/* - * Scheduler clock - returns current tim in nanosec units. - */ - -unsigned long long sched_clock(void) +static cycle_t ccount_read(void) { - return (unsigned long long)jiffies * (1000000000 / HZ); + return (cycle_t)get_ccount(); } +static struct clocksource ccount_clocksource = { + .name = "ccount", + .rating = 200, + .read = ccount_read, + .mask = CLOCKSOURCE_MASK(32), + /* + * With a shift of 22 the lower limit of the cpu clock is + * 1MHz, where NSEC_PER_CCOUNT is 1000 or a bit less than + * 2^10: Since we have 32 bits and the multiplicator can + * already take up as much as 10 bits, this leaves us with + * remaining upper 22 bits. + */ + .shift = 22, +}; + static irqreturn_t timer_interrupt(int irq, void *dev_id); static struct irqaction timer_irqaction = { .handler = timer_interrupt, @@ -55,11 +59,11 @@ static struct irqaction timer_irqaction = { void __init time_init(void) { - time_t sec_o, sec_n = 0; + xtime.tv_nsec = 0; + xtime.tv_sec = read_persistent_clock(); - /* The platform must provide a function to calibrate the processor - * speed for the CALIBRATE. - */ + set_normalized_timespec(&wall_to_monotonic, + -xtime.tv_sec, -xtime.tv_nsec); #ifdef CONFIG_XTENSA_CALIBRATE_CCOUNT printk("Calibrating CPU frequency "); @@ -67,19 +71,10 @@ void __init time_init(void) printk("%d.%02d MHz\n", (int)ccount_per_jiffy/(1000000/HZ), (int)(ccount_per_jiffy/(10000/HZ))%100); #endif - - /* Set time from RTC (if provided) */ - - if (platform_get_rtc_time(&sec_o) == 0) - while (platform_get_rtc_time(&sec_n)) - if (sec_o != sec_n) - break; - - xtime.tv_nsec = 0; - last_rtc_update = xtime.tv_sec = sec_n; - - set_normalized_timespec(&wall_to_monotonic, - -xtime.tv_sec, -xtime.tv_nsec); + ccount_clocksource.mult = + clocksource_hz2mult(CCOUNT_PER_JIFFY * HZ, + ccount_clocksource.shift); + clocksource_register(&ccount_clocksource); /* Initialize the linux timer interrupt. */ @@ -87,69 +82,6 @@ void __init time_init(void) set_linux_timer(get_ccount() + CCOUNT_PER_JIFFY); } - -int do_settimeofday(struct timespec *tv) -{ - time_t wtm_sec, sec = tv->tv_sec; - long wtm_nsec, nsec = tv->tv_nsec; - unsigned long delta; - - if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) - return -EINVAL; - - write_seqlock_irq(&xtime_lock); - - /* This is revolting. We need to set "xtime" correctly. However, the - * value in this location is the value at the most recent update of - * wall time. Discover what correction gettimeofday() would have - * made, and then undo it! - */ - - delta = CCOUNT_PER_JIFFY; - delta += get_ccount() - get_linux_timer(); - nsec -= delta * NSEC_PER_CCOUNT; - - wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec); - wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec); - - set_normalized_timespec(&xtime, sec, nsec); - set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec); - - ntp_clear(); - write_sequnlock_irq(&xtime_lock); - return 0; -} - -EXPORT_SYMBOL(do_settimeofday); - - -void do_gettimeofday(struct timeval *tv) -{ - unsigned long flags; - unsigned long volatile sec, usec, delta, seq; - - do { - seq = read_seqbegin_irqsave(&xtime_lock, flags); - - sec = xtime.tv_sec; - usec = (xtime.tv_nsec / NSEC_PER_USEC); - - delta = get_linux_timer() - get_ccount(); - - } while (read_seqretry_irqrestore(&xtime_lock, seq, flags)); - - usec += (((unsigned long) CCOUNT_PER_JIFFY - delta) - * (unsigned long) NSEC_PER_CCOUNT) / NSEC_PER_USEC; - - for (; usec >= 1000000; sec++, usec -= 1000000) - ; - - tv->tv_sec = sec; - tv->tv_usec = usec; -} - -EXPORT_SYMBOL(do_gettimeofday); - /* * The timer interrupt is called HZ times per second. */ @@ -178,16 +110,6 @@ again: next += CCOUNT_PER_JIFFY; set_linux_timer(next); - if (ntp_synced() && - xtime.tv_sec - last_rtc_update >= 659 && - abs((xtime.tv_nsec/1000)-(1000000-1000000/HZ))<5000000/HZ) { - - if (platform_set_rtc_time(xtime.tv_sec+1) == 0) - last_rtc_update = xtime.tv_sec+1; - else - /* Do it again in 60 s */ - last_rtc_update += 60; - } write_sequnlock(&xtime_lock); } @@ -213,4 +135,3 @@ void __cpuinit calibrate_delay(void) (loops_per_jiffy/(10000/HZ)) % 100); } #endif - |