/* $Id: time.c,v 1.12 2003/06/28 15:35:28 lethal Exp $
*
* linux/arch/sh/kernel/time.c
*
* Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka
* Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
* Copyright (C) 2002, 2003 Paul Mundt
* Copyright (C) 2002 M. R. Brown <mrbrown@linux-sh.org>
*
* Some code taken from i386 version.
* Copyright (C) 1991, 1992, 1995 Linus Torvalds
*/
#include <linux/config.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/time.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/smp.h>
#include <asm/processor.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/delay.h>
#include <asm/machvec.h>
#include <asm/rtc.h>
#include <asm/freq.h>
#ifdef CONFIG_SH_KGDB
#include <asm/kgdb.h>
#endif
#include <linux/timex.h>
#include <linux/irq.h>
#define TMU_TOCR_INIT 0x00
#define TMU0_TCR_INIT 0x0020
#define TMU_TSTR_INIT 1
#define TMU0_TCR_CALIB 0x0000
#if defined(CONFIG_CPU_SH3)
#define TMU_TOCR 0xfffffe90 /* Byte access */
#define TMU_TSTR 0xfffffe92 /* Byte access */
#define TMU0_TCOR 0xfffffe94 /* Long access */
#define TMU0_TCNT 0xfffffe98 /* Long access */
#define TMU0_TCR 0xfffffe9c /* Word access */
#elif defined(CONFIG_CPU_SH4)
#define TMU_TOCR 0xffd80000 /* Byte access */
#define TMU_TSTR 0xffd80004 /* Byte access */
#define TMU0_TCOR 0xffd80008 /* Long access */
#define TMU0_TCNT 0xffd8000c /* Long access */
#define TMU0_TCR 0xffd80010 /* Word access */
#ifdef CONFIG_CPU_SUBTYPE_ST40STB1
#define CLOCKGEN_MEMCLKCR 0xbb040038
#define MEMCLKCR_RATIO_MASK 0x7
#endif /* CONFIG_CPU_SUBTYPE_ST40STB1 */
#endif /* CONFIG_CPU_SH3 or CONFIG_CPU_SH4 */
extern unsigned long wall_jiffies;
#define TICK_SIZE (TICK_NSEC / 1000)
spinlock_t tmu0_lock = SPIN_LOCK_UNLOCKED;
u64 jiffies_64 = INITIAL_JIFFIES;
EXPORT_SYMBOL(jiffies_64);
/* XXX: Can we initialize this in a routine somewhere? Dreamcast doesn't want
* these routines anywhere... */
#ifdef CONFIG_SH_RTC
void (*rtc_get_time)(struct timespec *) = sh_rtc_gettimeofday;
int (*rtc_set_time)(const time_t) = sh_rtc_settimeofday;
#else
void (*rtc_get_time)(struct timespec *) = 0;
int (*rtc_set_time)(const time_t) = 0;
#endif
#if defined(CONFIG_CPU_SH3)
#error "FIXME"
static int ifc_table[] = { 1, 2, 4, 1, 3, 1, 1, 1 };
static int pfc_table[] = { 1, 2, 4, 1, 3, 6, 1, 1 };
static int stc_table[] = { 1, 2, 4, 8, 3, 6, 1, 1 };
#elif defined(CONFIG_CPU_SH4)
static int ifc_divisors[] = { 1, 2, 3, 4, 6, 8, 1, 1 };
static int ifc_values[] = { 0, 1, 2, 3, 0, 4, 0, 5 };
#define bfc_divisors ifc_divisors /* Same */
#define bfc_values ifc_values
static int pfc_divisors[] = { 2, 3, 4, 6, 8, 2, 2, 2 };
static int pfc_values[] = { 0, 0, 1, 2, 0, 3, 0, 4 };
#else
#error "Unknown ifc/bfc/pfc/stc values for this processor"
#endif
static unsigned long do_gettimeoffset(void)
{
int count;
unsigned long flags;
static int count_p = 0x7fffffff; /* for the first call after boot */
static unsigned long jiffies_p = 0;
/*
* cache volatile jiffies temporarily; we have IRQs turned off.
*/
unsigned long jiffies_t;
spin_lock_irqsave(&tmu0_lock, flags);
/* timer count may underflow right here */
count = ctrl_inl(TMU0_TCNT); /* read the latched count */
jiffies_t = jiffies;
/*
* avoiding timer inconsistencies (they are rare, but they happen)...
* there is one kind of problem that must be avoided here:
* 1. the timer counter underflows
*/
if( jiffies_t == jiffies_p ) {
if( count > count_p ) {
/* the nutcase */
if(ctrl_inw(TMU0_TCR) & 0x100) { /* Check UNF bit */
/*
* We cannot detect lost timer interrupts ...
* well, that's why we call them lost, don't we? :)
* [hmm, on the Pentium and Alpha we can ... sort of]
*/
count -= LATCH;
} else {
printk("do_slow_gettimeoffset(): hardware timer problem?\n");
}
}
} else
jiffies_p = jiffies_t;
count_p = count;
spin_unlock_irqrestore(&tmu0_lock, flags);
count = ((LATCH-1) - count) * TICK_SIZE;
count = (count + LATCH/2) / LATCH;
return count;
}
void do_gettimeofday(struct timeval *tv)
{
unsigned long seq;
unsigned long usec, sec;
unsigned long lost;
do {
seq = read_seqbegin(&xtime_lock);
usec = do_gettimeoffset();
lost = jiffies - wall_jiffies;
if (lost)
usec += lost * (1000000 / HZ);
sec = xtime.tv_sec;
usec += xtime.tv_nsec / 1000;
} while (read_seqretry(&xtime_lock, seq));
while (usec >= 1000000) {
usec -= 1000000;
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 "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!
*/
nsec -= 1000 * (do_gettimeoffset() +
(jiffies - wall_jiffies) * (1000000 / HZ));
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);
time_adjust = 0; /* stop active adjtime() */
time_status |= STA_UNSYNC;
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
write_sequnlock_irq(&xtime_lock);
clock_was_set();
return 0;
}
EXPORT_SYMBOL(do_settimeofday);
/* last time the RTC clock got updated */
static long last_rtc_update;
/* Profiling definitions */
extern unsigned long prof_cpu_mask;
extern unsigned int * prof_buffer;
extern unsigned long prof_len;
extern unsigned long prof_shift;
extern char _stext;
static inline void sh_do_profile(unsigned long pc)
{
if (!prof_buffer)
return;
if (pc >= 0xa0000000UL && pc < 0xc0000000UL)
pc -= 0x20000000;
pc -= (unsigned long)&_stext;
pc >>= prof_shift;
/*
* Don't ignore out-of-bounds PC values silently,
* put them into the last histogram slot, so if
* present, they will show up as a sharp peak.
*/
if (pc > prof_len - 1)
pc = prof_len - 1;
atomic_inc((atomic_t *)&prof_buffer[pc]);
}
/*
* timer_interrupt() needs to keep up the real-time clock,
* as well as call the "do_timer()" routine every clocktick
*/
static inline void do_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
do_timer(regs);
if (!user_mode(regs))
sh_do_profile(regs->pc);
#ifdef CONFIG_HEARTBEAT
if (sh_mv.mv_heartbeat != NULL)
sh_mv.mv_heartbeat();
#endif
/*
* If we have an externally synchronized Linux clock, then update
* RTC 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 ((time_status & STA_UNSYNC) == 0 &&
xtime.tv_sec > last_rtc_update + 660 &&
(xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
(xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
if (rtc_set_time(xtime.tv_sec) == 0)
last_rtc_update = xtime.tv_sec;
else
last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */
}
}
/*
* This is the same as the above, except we _also_ save the current
* Time Stamp Counter value at the time of the timer interrupt, so that
* we later on can estimate the time of day more exactly.
*/
static irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
unsigned long timer_status;
/* Clear UNF bit */
timer_status = ctrl_inw(TMU0_TCR);
timer_status &= ~0x100;
ctrl_outw(timer_status, TMU0_TCR);
/*
* Here we are in the timer irq handler. We just have irqs locally
* disabled but we don't know if the timer_bh is running on the other
* CPU. We need to avoid to SMP race with it. NOTE: we don' t need
* the irq version of write_lock because as just said we have irq
* locally disabled. -arca
*/
write_seqlock(&xtime_lock);
do_timer_interrupt(irq, NULL, regs);
write_sequnlock(&xtime_lock);
return IRQ_HANDLED;
}
/*
* Hah! We'll see if this works (switching from usecs to nsecs).
*/
static unsigned int __init get_timer_frequency(void)
{
u32 freq;
struct timespec ts1, ts2;
unsigned long diff_nsec;
unsigned long factor;
/* Setup the timer: We don't want to generate interrupts, just
* have it count down at its natural rate.
*/
ctrl_outb(0, TMU_TSTR);
ctrl_outb(TMU_TOCR_INIT, TMU_TOCR);
ctrl_outw(TMU0_TCR_CALIB, TMU0_TCR);
ctrl_outl(0xffffffff, TMU0_TCOR);
ctrl_outl(0xffffffff, TMU0_TCNT);
rtc_get_time(&ts2);
do {
rtc_get_time(&ts1);
} while (ts1.tv_nsec == ts2.tv_nsec && ts1.tv_sec == ts2.tv_sec);
/* actually start the timer */
ctrl_outb(TMU_TSTR_INIT, TMU_TSTR);
do {
rtc_get_time(&ts2);
} while (ts1.tv_nsec == ts2.tv_nsec && ts1.tv_sec == ts2.tv_sec);
freq = 0xffffffff - ctrl_inl(TMU0_TCNT);
if (ts2.tv_nsec < ts1.tv_nsec) {
ts2.tv_nsec += 1000000000;
ts2.tv_sec--;
}
diff_nsec = (ts2.tv_sec - ts1.tv_sec) * 1000000000 + (ts2.tv_nsec - ts1.tv_nsec);
/* this should work well if the RTC has a precision of n Hz, where
* n is an integer. I don't think we have to worry about the other
* cases. */
factor = (1000000000 + diff_nsec/2) / diff_nsec;
if (factor * diff_nsec > 1100000000 ||
factor * diff_nsec < 900000000)
panic("weird RTC (diff_nsec %ld)", diff_nsec);
return freq * factor;
}
void (*board_time_init)(void) = 0;
void (*board_timer_setup)(struct irqaction *irq) = 0;
static struct irqaction irq0 = { timer_interrupt, SA_INTERRUPT, 0, "timer", NULL, NULL};
void get_current_frequency_divisors(unsigned int *ifc, unsigned int *bfc, unsigned int *pfc)
{
unsigned int frqcr = ctrl_inw(FRQCR);
#if defined(CONFIG_CPU_SH3)
unsigned int tmp;
tmp = (frqcr & 0x8000) >> 13;
tmp |= (frqcr & 0x0030) >> 4;
*bfc = stc_table[tmp];
tmp = (frqcr & 0x4000) >> 12;
tmp |= (frqcr & 0x000c) >> 2;
*ifc = ifc_table[tmp];
tmp = (frqcr & 0x2000) >> 11;
tmp |= frqcr & 0x0003;
*pfc = pfc_table[tmp];
#elif defined(CONFIG_CPU_SH4)
*ifc = ifc_divisors[(frqcr >> 6) & 0x0007];
*bfc = bfc_divisors[(frqcr >> 3) & 0x0007];
*pfc = pfc_divisors[frqcr & 0x0007];
#endif
}
/*
* This bit of ugliness builds up accessor routines to get at both
* the divisors and the physical values.
*/
#define _FREQ_TABLE(x) \
unsigned int get_##x##_divisor(unsigned int value) \
{ return x##_divisors[value]; } \
\
unsigned int get_##x##_value(unsigned int divisor) \
{ return x##_values[(divisor - 1)]; }
_FREQ_TABLE(ifc);
_FREQ_TABLE(bfc);
_FREQ_TABLE(pfc);
void __init time_init(void)
{
unsigned int timer_freq;
unsigned int ifc, pfc, bfc;
unsigned long interval;
if (board_time_init)
board_time_init();
/*
* XXX: Hmm... when cpu/ is proposed, this looks like a good spot for
* it, but we need a rtc to get the timer_freq so board_time_init()
* must always come before a CPU time_(rtc?)_init().
*/
get_current_frequency_divisors(&ifc, &bfc, &pfc);
timer_freq = get_timer_frequency();
current_cpu_data.module_clock = timer_freq * 4;
rtc_get_time(&xtime);
set_normalized_timespec(&wall_to_monotonic,
-xtime.tv_sec, -xtime.tv_nsec);
if (board_timer_setup) {
board_timer_setup(&irq0);
} else {
setup_irq(TIMER_IRQ, &irq0);
}
if (!current_cpu_data.master_clock)
current_cpu_data.master_clock = current_cpu_data.module_clock * pfc;
if (!current_cpu_data.bus_clock)
current_cpu_data.bus_clock = current_cpu_data.master_clock / bfc;
if (!current_cpu_data.cpu_clock)
current_cpu_data.cpu_clock = current_cpu_data.master_clock / ifc;
printk("CPU clock: %d.%02dMHz\n",
(current_cpu_data.cpu_clock / 1000000),
(current_cpu_data.cpu_clock % 1000000)/10000);
printk("Bus clock: %d.%02dMHz\n",
(current_cpu_data.bus_clock / 1000000),
(current_cpu_data.bus_clock % 1000000)/10000);
#ifdef CONFIG_CPU_SUBTYPE_ST40STB1
printk("Memory clock: %d.%02dMHz\n",
(current_cpu_data.memory_clock / 1000000),
(current_cpu_data.memory_clock % 1000000)/10000);
#endif
printk("Module clock: %d.%02dMHz\n",
(current_cpu_data.module_clock / 1000000),
(current_cpu_data.module_clock % 1000000)/10000);
interval = (current_cpu_data.module_clock/4 + HZ/2) / HZ;
printk("Interval = %ld\n", interval);
/* Start TMU0 */
ctrl_outb(0, TMU_TSTR);
ctrl_outb(TMU_TOCR_INIT, TMU_TOCR);
ctrl_outw(TMU0_TCR_INIT, TMU0_TCR);
ctrl_outl(interval, TMU0_TCOR);
ctrl_outl(interval, TMU0_TCNT);
ctrl_outb(TMU_TSTR_INIT, TMU_TSTR);
#if defined(CONFIG_SH_KGDB)
/*
* Set up kgdb as requested. We do it here because the serial
* init uses the timer vars we just set up for figuring baud.
*/
kgdb_init();
#endif
}
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