/*
* arch/sh/kernel/time.c
*
* Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka
* Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
* Copyright (C) 2002, 2003, 2004 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 <linux/profile.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>
#include <asm/cpu/timer.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
#ifdef CONFIG_CPU_SUBTYPE_ST40STB1
#define CLOCKGEN_MEMCLKCR 0xbb040038
#define MEMCLKCR_RATIO_MASK 0x7
#endif /* CONFIG_CPU_SUBTYPE_ST40STB1 */
extern unsigned long wall_jiffies;
#define TICK_SIZE (tick_nsec / 1000)
DEFINE_SPINLOCK(tmu0_lock);
/* 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 *);
int (*rtc_set_time)(const time_t);
#endif
#if defined(CONFIG_CPU_SUBTYPE_SH7300)
static int md_table[] = { 1, 2, 3, 4, 6, 8, 12 };
#endif
#if defined(CONFIG_CPU_SH3)
static int stc_multipliers[] = { 1, 2, 3, 4, 6, 1, 1, 1 };
static int stc_values[] = { 0, 1, 4, 2, 5, 0, 0, 0 };
#define bfc_divisors stc_multipliers
#define bfc_values stc_values
static int ifc_divisors[] = { 1, 2, 3, 4, 1, 1, 1, 1 };
static int ifc_values[] = { 0, 1, 4, 2, 0, 0, 0, 0 };
static int pfc_divisors[] = { 1, 2, 3, 4, 6, 1, 1, 1 };
static int pfc_values[] = { 0, 1, 4, 2, 5, 0, 0, 0 };
#elif defined(CONFIG_CPU_SH4)
#if defined(CONFIG_CPU_SUBTYPE_SH73180)
static int ifc_divisors[] = { 1, 2, 3, 4, 6, 8, 12, 16 };
static int ifc_values[] = { 0, 1, 2, 3, 4, 5, 6, 7 };
#define bfc_divisors ifc_divisors /* Same */
#define bfc_values ifc_values
#define pfc_divisors ifc_divisors /* Same */
#define pfc_values ifc_values
#else
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 };
#endif
#else
#error "Unknown ifc/bfc/pfc/stc values for this processor"
#endif
/*
* Scheduler clock - returns current time in nanosec units.
*/
unsigned long long sched_clock(void)
{
return (unsigned long long)jiffies * (1000000000 / HZ);
}
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);
ntp_clear();
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;
/*
* 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, struct pt_regs *regs)
{
do_timer(regs);
#ifndef CONFIG_SMP
update_process_times(user_mode(regs));
#endif
profile_tick(CPU_PROFILING, regs);
#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 (ntp_synced() &&
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, 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);
#if !defined(CONFIG_CPU_SUBTYPE_SH7300)
ctrl_outb(TMU_TOCR_INIT, TMU_TOCR);
#endif
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);
void (*board_timer_setup)(struct irqaction *irq);
static unsigned int sh_pclk_freq __initdata = CONFIG_SH_PCLK_FREQ;
static int __init sh_pclk_setup(char *str)
{
unsigned int freq;
if (get_option(&str, &freq))
sh_pclk_freq = freq;
return 1;
}
__setup("sh_pclk=", sh_pclk_setup);
static struct irqaction irq0 = { timer_interrupt, SA_INTERRUPT, CPU_MASK_NONE, "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)
#if defined(CONFIG_CPU_SUBTYPE_SH7300)
*ifc = md_table[((frqcr & 0x0070) >> 4)];
*bfc = md_table[((frqcr & 0x0700) >> 8)];
*pfc = md_table[frqcr & 0x0007];
#elif defined(CONFIG_CPU_SUBTYPE_SH7705)
*bfc = stc_multipliers[(frqcr & 0x0300) >> 8];
*ifc = ifc_divisors[(frqcr & 0x0030) >> 4];
*pfc = pfc_divisors[frqcr & 0x0003];
#else
unsigned int tmp;
tmp = (frqcr & 0x8000) >> 13;
tmp |= (frqcr & 0x0030) >> 4;
*bfc = stc_multipliers[tmp];
tmp = (frqcr & 0x4000) >> 12;
tmp |= (frqcr & 0x000c) >> 2;
*ifc = ifc_divisors[tmp];
tmp = (frqcr & 0x2000) >> 11;
tmp |= frqcr & 0x0003;
*pfc = pfc_divisors[tmp];
#endif
#elif defined(CONFIG_CPU_SH4)
#if defined(CONFIG_CPU_SUBTYPE_SH73180)
*ifc = ifc_divisors[(frqcr>> 20) & 0x0007];
*bfc = bfc_divisors[(frqcr>> 12) & 0x0007];
*pfc = pfc_divisors[frqcr & 0x0007];
#else
*ifc = ifc_divisors[(frqcr >> 6) & 0x0007];
*bfc = bfc_divisors[(frqcr >> 3) & 0x0007];
*pfc = pfc_divisors[frqcr & 0x0007];
#endif
#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);
#ifdef CONFIG_CPU_SUBTYPE_ST40STB1
/*
* The ST40 divisors are totally different so we set the cpu data
* clocks using a different algorithm
*
* I've just plugged this from the 2.4 code
* - Alex Bennee <kernel-hacker@bennee.com>
*/
#define CCN_PVR_CHIP_SHIFT 24
#define CCN_PVR_CHIP_MASK 0xff
#define CCN_PVR_CHIP_ST40STB1 0x4
struct frqcr_data {
unsigned short frqcr;
struct {
unsigned char multiplier;
unsigned char divisor;
} factor[3];
};
static struct frqcr_data st40_frqcr_table[] = {
{ 0x000, {{1,1}, {1,1}, {1,2}}},
{ 0x002, {{1,1}, {1,1}, {1,4}}},
{ 0x004, {{1,1}, {1,1}, {1,8}}},
{ 0x008, {{1,1}, {1,2}, {1,2}}},
{ 0x00A, {{1,1}, {1,2}, {1,4}}},
{ 0x00C, {{1,1}, {1,2}, {1,8}}},
{ 0x011, {{1,1}, {2,3}, {1,6}}},
{ 0x013, {{1,1}, {2,3}, {1,3}}},
{ 0x01A, {{1,1}, {1,2}, {1,4}}},
{ 0x01C, {{1,1}, {1,2}, {1,8}}},
{ 0x023, {{1,1}, {2,3}, {1,3}}},
{ 0x02C, {{1,1}, {1,2}, {1,8}}},
{ 0x048, {{1,2}, {1,2}, {1,4}}},
{ 0x04A, {{1,2}, {1,2}, {1,6}}},
{ 0x04C, {{1,2}, {1,2}, {1,8}}},
{ 0x05A, {{1,2}, {1,3}, {1,6}}},
{ 0x05C, {{1,2}, {1,3}, {1,6}}},
{ 0x063, {{1,2}, {1,4}, {1,4}}},
{ 0x06C, {{1,2}, {1,4}, {1,8}}},
{ 0x091, {{1,3}, {1,3}, {1,6}}},
{ 0x093, {{1,3}, {1,3}, {1,6}}},
{ 0x0A3, {{1,3}, {1,6}, {1,6}}},
{ 0x0DA, {{1,4}, {1,4}, {1,8}}},
{ 0x0DC, {{1,4}, {1,4}, {1,8}}},
{ 0x0EC, {{1,4}, {1,8}, {1,8}}},
{ 0x123, {{1,4}, {1,4}, {1,8}}},
{ 0x16C, {{1,4}, {1,8}, {1,8}}},
};
struct memclk_data {
unsigned char multiplier;
unsigned char divisor;
};
static struct memclk_data st40_memclk_table[8] = {
{1,1}, // 000
{1,2}, // 001
{1,3}, // 010
{2,3}, // 011
{1,4}, // 100
{1,6}, // 101
{1,8}, // 110
{1,8} // 111
};
static void st40_specific_time_init(unsigned int module_clock, unsigned short frqcr)
{
unsigned int cpu_clock, master_clock, bus_clock, memory_clock;
struct frqcr_data *d;
int a;
unsigned long memclkcr;
struct memclk_data *e;
for (a = 0; a < ARRAY_SIZE(st40_frqcr_table); a++) {
d = &st40_frqcr_table[a];
if (d->frqcr == (frqcr & 0x1ff))
break;
}
if (a == ARRAY_SIZE(st40_frqcr_table)) {
d = st40_frqcr_table;
printk("ERROR: Unrecognised FRQCR value (0x%x), "
"using default multipliers\n", frqcr);
}
memclkcr = ctrl_inl(CLOCKGEN_MEMCLKCR);
e = &st40_memclk_table[memclkcr & MEMCLKCR_RATIO_MASK];
printk(KERN_INFO "Clock multipliers: CPU: %d/%d Bus: %d/%d "
"Mem: %d/%d Periph: %d/%d\n",
d->factor[0].multiplier, d->factor[0].divisor,
d->factor[1].multiplier, d->factor[1].divisor,
e->multiplier, e->divisor,
d->factor[2].multiplier, d->factor[2].divisor);
master_clock = module_clock * d->factor[2].divisor
/ d->factor[2].multiplier;
bus_clock = master_clock * d->factor[1].multiplier
/ d->factor[1].divisor;
memory_clock = master_clock * e->multiplier
/ e->divisor;
cpu_clock = master_clock * d->factor[0].multiplier
/ d->factor[0].divisor;
current_cpu_data.cpu_clock = cpu_clock;
current_cpu_data.master_clock = master_clock;
current_cpu_data.bus_clock = bus_clock;
current_cpu_data.memory_clock = memory_clock;
current_cpu_data.module_clock = module_clock;
}
#endif
void __init time_init(void)
{
unsigned int timer_freq = 0;
unsigned int ifc, pfc, bfc;
unsigned long interval;
#ifdef CONFIG_CPU_SUBTYPE_ST40STB1
unsigned long pvr;
unsigned short frqcr;
#endif
if (board_time_init)
board_time_init();
/*
* If we don't have an RTC (such as with the SH7300), don't attempt to
* probe the timer frequency. Rely on an either hardcoded peripheral
* clock value, or on the sh_pclk command line option. Note that we
* still need to have CONFIG_SH_PCLK_FREQ set in order for things like
* CLOCK_TICK_RATE to be sane.
*/
current_cpu_data.module_clock = sh_pclk_freq;
#ifdef CONFIG_SH_PCLK_CALC
/* XXX: Switch this over to a more generic test. */
{
unsigned int freq;
/*
* If we've specified a peripheral clock frequency, and we have
* an RTC, compare it against the autodetected value. Complain
* if there's a mismatch.
*/
timer_freq = get_timer_frequency();
freq = timer_freq * 4;
if (sh_pclk_freq && (sh_pclk_freq/100*99 > freq || sh_pclk_freq/100*101 < freq)) {
printk(KERN_NOTICE "Calculated peripheral clock value "
"%d differs from sh_pclk value %d, fixing..\n",
freq, sh_pclk_freq);
current_cpu_data.module_clock = freq;
}
}
#endif
#ifdef CONFIG_CPU_SUBTYPE_ST40STB1
/* XXX: Update ST40 code to use board_time_init() */
pvr = ctrl_inl(CCN_PVR);
frqcr = ctrl_inw(FRQCR);
printk("time.c ST40 Probe: PVR %08lx, FRQCR %04hx\n", pvr, frqcr);
if (((pvr >> CCN_PVR_CHIP_SHIFT) & CCN_PVR_CHIP_MASK) == CCN_PVR_CHIP_ST40STB1)
st40_specific_time_init(current_cpu_data.module_clock, frqcr);
else
#endif
get_current_frequency_divisors(&ifc, &bfc, &pfc);
if (rtc_get_time) {
rtc_get_time(&xtime);
} else {
xtime.tv_sec = mktime(2000, 1, 1, 0, 0, 0);
xtime.tv_nsec = 0;
}
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);
}
/*
* for ST40 chips the current_cpu_data should already be set
* so not having valid pfc/bfc/ifc shouldn't be a problem
*/
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);
#if !defined(CONFIG_CPU_SUBTYPE_SH7300)
ctrl_outb(TMU_TOCR_INIT, TMU_TOCR);
#endif
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
}
