253 строки
6.0 KiB
C
253 строки
6.0 KiB
C
/*
|
|
* arch/blackfin/kernel/time.c
|
|
*
|
|
* This file contains the Blackfin-specific time handling details.
|
|
* Most of the stuff is located in the machine specific files.
|
|
*
|
|
* Copyright 2004-2008 Analog Devices Inc.
|
|
* Licensed under the GPL-2 or later.
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/profile.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/time.h>
|
|
#include <linux/irq.h>
|
|
#include <linux/delay.h>
|
|
|
|
#include <asm/blackfin.h>
|
|
#include <asm/time.h>
|
|
#include <asm/gptimers.h>
|
|
|
|
/* This is an NTP setting */
|
|
#define TICK_SIZE (tick_nsec / 1000)
|
|
|
|
static struct irqaction bfin_timer_irq = {
|
|
.name = "Blackfin Timer Tick",
|
|
.flags = IRQF_DISABLED
|
|
};
|
|
|
|
#if defined(CONFIG_IPIPE)
|
|
void __init setup_system_timer0(void)
|
|
{
|
|
/* Power down the core timer, just to play safe. */
|
|
bfin_write_TCNTL(0);
|
|
|
|
disable_gptimers(TIMER0bit);
|
|
set_gptimer_status(0, TIMER_STATUS_TRUN0);
|
|
while (get_gptimer_status(0) & TIMER_STATUS_TRUN0)
|
|
udelay(10);
|
|
|
|
set_gptimer_config(0, 0x59); /* IRQ enable, periodic, PWM_OUT, SCLKed, OUT PAD disabled */
|
|
set_gptimer_period(TIMER0_id, get_sclk() / HZ);
|
|
set_gptimer_pwidth(TIMER0_id, 1);
|
|
SSYNC();
|
|
enable_gptimers(TIMER0bit);
|
|
}
|
|
#else
|
|
void __init setup_core_timer(void)
|
|
{
|
|
u32 tcount;
|
|
|
|
/* power up the timer, but don't enable it just yet */
|
|
bfin_write_TCNTL(1);
|
|
CSYNC();
|
|
|
|
/* the TSCALE prescaler counter */
|
|
bfin_write_TSCALE(TIME_SCALE - 1);
|
|
|
|
tcount = ((get_cclk() / (HZ * TIME_SCALE)) - 1);
|
|
bfin_write_TPERIOD(tcount);
|
|
bfin_write_TCOUNT(tcount);
|
|
|
|
/* now enable the timer */
|
|
CSYNC();
|
|
|
|
bfin_write_TCNTL(7);
|
|
}
|
|
#endif
|
|
|
|
static void __init
|
|
time_sched_init(irqreturn_t(*timer_routine) (int, void *))
|
|
{
|
|
#if defined(CONFIG_IPIPE)
|
|
setup_system_timer0();
|
|
bfin_timer_irq.handler = timer_routine;
|
|
setup_irq(IRQ_TIMER0, &bfin_timer_irq);
|
|
#else
|
|
setup_core_timer();
|
|
bfin_timer_irq.handler = timer_routine;
|
|
setup_irq(IRQ_CORETMR, &bfin_timer_irq);
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Should return useconds since last timer tick
|
|
*/
|
|
#ifndef CONFIG_GENERIC_TIME
|
|
static unsigned long gettimeoffset(void)
|
|
{
|
|
unsigned long offset;
|
|
unsigned long clocks_per_jiffy;
|
|
|
|
#if defined(CONFIG_IPIPE)
|
|
clocks_per_jiffy = bfin_read_TIMER0_PERIOD();
|
|
offset = bfin_read_TIMER0_COUNTER() / \
|
|
(((clocks_per_jiffy + 1) * HZ) / USEC_PER_SEC);
|
|
|
|
if ((get_gptimer_status(0) & TIMER_STATUS_TIMIL0) && offset < (100000 / HZ / 2))
|
|
offset += (USEC_PER_SEC / HZ);
|
|
#else
|
|
clocks_per_jiffy = bfin_read_TPERIOD();
|
|
offset = (clocks_per_jiffy - bfin_read_TCOUNT()) / \
|
|
(((clocks_per_jiffy + 1) * HZ) / USEC_PER_SEC);
|
|
|
|
/* Check if we just wrapped the counters and maybe missed a tick */
|
|
if ((bfin_read_ILAT() & (1 << IRQ_CORETMR))
|
|
&& (offset < (100000 / HZ / 2)))
|
|
offset += (USEC_PER_SEC / HZ);
|
|
#endif
|
|
return offset;
|
|
}
|
|
#endif
|
|
|
|
static inline int set_rtc_mmss(unsigned long nowtime)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* timer_interrupt() needs to keep up the real-time clock,
|
|
* as well as call the "do_timer()" routine every clocktick
|
|
*/
|
|
#ifdef CONFIG_CORE_TIMER_IRQ_L1
|
|
__attribute__((l1_text))
|
|
#endif
|
|
irqreturn_t timer_interrupt(int irq, void *dummy)
|
|
{
|
|
/* last time the cmos clock got updated */
|
|
static long last_rtc_update;
|
|
|
|
write_seqlock(&xtime_lock);
|
|
do_timer(1);
|
|
|
|
/*
|
|
* 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 > last_rtc_update + 660 &&
|
|
(xtime.tv_nsec / NSEC_PER_USEC) >=
|
|
500000 - ((unsigned)TICK_SIZE) / 2
|
|
&& (xtime.tv_nsec / NSEC_PER_USEC) <=
|
|
500000 + ((unsigned)TICK_SIZE) / 2) {
|
|
if (set_rtc_mmss(xtime.tv_sec) == 0)
|
|
last_rtc_update = xtime.tv_sec;
|
|
else
|
|
/* Do it again in 60s. */
|
|
last_rtc_update = xtime.tv_sec - 600;
|
|
}
|
|
write_sequnlock(&xtime_lock);
|
|
|
|
#ifdef CONFIG_IPIPE
|
|
update_root_process_times(get_irq_regs());
|
|
#else
|
|
update_process_times(user_mode(get_irq_regs()));
|
|
#endif
|
|
profile_tick(CPU_PROFILING);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
void __init time_init(void)
|
|
{
|
|
time_t secs_since_1970 = (365 * 37 + 9) * 24 * 60 * 60; /* 1 Jan 2007 */
|
|
|
|
#ifdef CONFIG_RTC_DRV_BFIN
|
|
/* [#2663] hack to filter junk RTC values that would cause
|
|
* userspace to have to deal with time values greater than
|
|
* 2^31 seconds (which uClibc cannot cope with yet)
|
|
*/
|
|
if ((bfin_read_RTC_STAT() & 0xC0000000) == 0xC0000000) {
|
|
printk(KERN_NOTICE "bfin-rtc: invalid date; resetting\n");
|
|
bfin_write_RTC_STAT(0);
|
|
}
|
|
#endif
|
|
|
|
/* Initialize xtime. From now on, xtime is updated with timer interrupts */
|
|
xtime.tv_sec = secs_since_1970;
|
|
xtime.tv_nsec = 0;
|
|
|
|
wall_to_monotonic.tv_sec = -xtime.tv_sec;
|
|
|
|
time_sched_init(timer_interrupt);
|
|
}
|
|
|
|
#ifndef CONFIG_GENERIC_TIME
|
|
void do_gettimeofday(struct timeval *tv)
|
|
{
|
|
unsigned long flags;
|
|
unsigned long seq;
|
|
unsigned long usec, sec;
|
|
|
|
do {
|
|
seq = read_seqbegin_irqsave(&xtime_lock, flags);
|
|
usec = gettimeoffset();
|
|
sec = xtime.tv_sec;
|
|
usec += (xtime.tv_nsec / NSEC_PER_USEC);
|
|
}
|
|
while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
|
|
|
|
while (usec >= USEC_PER_SEC) {
|
|
usec -= USEC_PER_SEC;
|
|
sec++;
|
|
}
|
|
|
|
tv->tv_sec = sec;
|
|
tv->tv_usec = usec;
|
|
}
|
|
EXPORT_SYMBOL(do_gettimeofday);
|
|
|
|
int do_settimeofday(struct timespec *tv)
|
|
{
|
|
time_t wtm_sec, sec = tv->tv_sec;
|
|
long wtm_nsec, nsec = tv->tv_nsec;
|
|
|
|
if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
|
|
return -EINVAL;
|
|
|
|
write_seqlock_irq(&xtime_lock);
|
|
/*
|
|
* This is revolting. We need to set the xtime.tv_usec
|
|
* correctly. However, the value in this location is
|
|
* is value at the last tick.
|
|
* Discover what correction gettimeofday
|
|
* would have done, and then undo it!
|
|
*/
|
|
nsec -= (gettimeoffset() * NSEC_PER_USEC);
|
|
|
|
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);
|
|
clock_was_set();
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(do_settimeofday);
|
|
#endif /* !CONFIG_GENERIC_TIME */
|
|
|
|
/*
|
|
* Scheduler clock - returns current time in nanosec units.
|
|
*/
|
|
unsigned long long sched_clock(void)
|
|
{
|
|
return (unsigned long long)jiffies *(NSEC_PER_SEC / HZ);
|
|
}
|