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linux-stable-rt/arch/sparc/kernel/time.c

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/* $Id: time.c,v 1.60 2002/01/23 14:33:55 davem Exp $
* linux/arch/sparc/kernel/time.c
*
* Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
* Copyright (C) 1996 Thomas K. Dyas (tdyas@eden.rutgers.edu)
*
* Chris Davis (cdavis@cois.on.ca) 03/27/1998
* Added support for the intersil on the sun4/4200
*
* Gleb Raiko (rajko@mech.math.msu.su) 08/18/1998
* Support for MicroSPARC-IIep, PCI CPU.
*
* This file handles the Sparc specific time handling details.
*
* 1997-09-10 Updated NTP code according to technical memorandum Jan '96
* "A Kernel Model for Precision Timekeeping" by Dave Mills
*/
#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/timex.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/ioport.h>
#include <linux/profile.h>
#include <asm/oplib.h>
#include <asm/timer.h>
#include <asm/mostek.h>
#include <asm/system.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/idprom.h>
#include <asm/machines.h>
#include <asm/sun4paddr.h>
#include <asm/page.h>
#include <asm/pcic.h>
#include <asm/of_device.h>
DEFINE_SPINLOCK(rtc_lock);
enum sparc_clock_type sp_clock_typ;
DEFINE_SPINLOCK(mostek_lock);
void __iomem *mstk48t02_regs = NULL;
static struct mostek48t08 __iomem *mstk48t08_regs = NULL;
static int set_rtc_mmss(unsigned long);
static int sbus_do_settimeofday(struct timespec *tv);
#ifdef CONFIG_SUN4
struct intersil *intersil_clock;
#define intersil_cmd(intersil_reg, intsil_cmd) intersil_reg->int_cmd_reg = \
(intsil_cmd)
#define intersil_intr(intersil_reg, intsil_cmd) intersil_reg->int_intr_reg = \
(intsil_cmd)
#define intersil_start(intersil_reg) intersil_cmd(intersil_reg, \
( INTERSIL_START | INTERSIL_32K | INTERSIL_NORMAL | INTERSIL_24H |\
INTERSIL_INTR_ENABLE))
#define intersil_stop(intersil_reg) intersil_cmd(intersil_reg, \
( INTERSIL_STOP | INTERSIL_32K | INTERSIL_NORMAL | INTERSIL_24H |\
INTERSIL_INTR_ENABLE))
#define intersil_read_intr(intersil_reg, towhere) towhere = \
intersil_reg->int_intr_reg
#endif
unsigned long profile_pc(struct pt_regs *regs)
{
extern char __copy_user_begin[], __copy_user_end[];
extern char __atomic_begin[], __atomic_end[];
extern char __bzero_begin[], __bzero_end[];
extern char __bitops_begin[], __bitops_end[];
unsigned long pc = regs->pc;
if (in_lock_functions(pc) ||
(pc >= (unsigned long) __copy_user_begin &&
pc < (unsigned long) __copy_user_end) ||
(pc >= (unsigned long) __atomic_begin &&
pc < (unsigned long) __atomic_end) ||
(pc >= (unsigned long) __bzero_begin &&
pc < (unsigned long) __bzero_end) ||
(pc >= (unsigned long) __bitops_begin &&
pc < (unsigned long) __bitops_end))
pc = regs->u_regs[UREG_RETPC];
return pc;
}
__volatile__ unsigned int *master_l10_counter;
__volatile__ unsigned int *master_l10_limit;
/*
* timer_interrupt() needs to keep up the real-time clock,
* as well as call the "do_timer()" routine every clocktick
*/
#define TICK_SIZE (tick_nsec / 1000)
irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs * regs)
{
/* last time the cmos clock got updated */
static long last_rtc_update;
#ifndef CONFIG_SMP
profile_tick(CPU_PROFILING, regs);
#endif
/* Protect counter clear so that do_gettimeoffset works */
write_seqlock(&xtime_lock);
#ifdef CONFIG_SUN4
if((idprom->id_machtype == (SM_SUN4 | SM_4_260)) ||
(idprom->id_machtype == (SM_SUN4 | SM_4_110))) {
int temp;
intersil_read_intr(intersil_clock, temp);
/* re-enable the irq */
enable_pil_irq(10);
}
#endif
clear_clock_irq();
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode(regs));
#endif
/* Determine when to update the Mostek clock. */
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 (set_rtc_mmss(xtime.tv_sec) == 0)
last_rtc_update = xtime.tv_sec;
else
last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */
}
write_sequnlock(&xtime_lock);
return IRQ_HANDLED;
}
/* Kick start a stopped clock (procedure from the Sun NVRAM/hostid FAQ). */
static void __init kick_start_clock(void)
{
struct mostek48t02 *regs = (struct mostek48t02 *)mstk48t02_regs;
unsigned char sec;
int i, count;
prom_printf("CLOCK: Clock was stopped. Kick start ");
spin_lock_irq(&mostek_lock);
/* Turn on the kick start bit to start the oscillator. */
regs->creg |= MSTK_CREG_WRITE;
regs->sec &= ~MSTK_STOP;
regs->hour |= MSTK_KICK_START;
regs->creg &= ~MSTK_CREG_WRITE;
spin_unlock_irq(&mostek_lock);
/* Delay to allow the clock oscillator to start. */
sec = MSTK_REG_SEC(regs);
for (i = 0; i < 3; i++) {
while (sec == MSTK_REG_SEC(regs))
for (count = 0; count < 100000; count++)
/* nothing */ ;
prom_printf(".");
sec = regs->sec;
}
prom_printf("\n");
spin_lock_irq(&mostek_lock);
/* Turn off kick start and set a "valid" time and date. */
regs->creg |= MSTK_CREG_WRITE;
regs->hour &= ~MSTK_KICK_START;
MSTK_SET_REG_SEC(regs,0);
MSTK_SET_REG_MIN(regs,0);
MSTK_SET_REG_HOUR(regs,0);
MSTK_SET_REG_DOW(regs,5);
MSTK_SET_REG_DOM(regs,1);
MSTK_SET_REG_MONTH(regs,8);
MSTK_SET_REG_YEAR(regs,1996 - MSTK_YEAR_ZERO);
regs->creg &= ~MSTK_CREG_WRITE;
spin_unlock_irq(&mostek_lock);
/* Ensure the kick start bit is off. If it isn't, turn it off. */
while (regs->hour & MSTK_KICK_START) {
prom_printf("CLOCK: Kick start still on!\n");
spin_lock_irq(&mostek_lock);
regs->creg |= MSTK_CREG_WRITE;
regs->hour &= ~MSTK_KICK_START;
regs->creg &= ~MSTK_CREG_WRITE;
spin_unlock_irq(&mostek_lock);
}
prom_printf("CLOCK: Kick start procedure successful.\n");
}
/* Return nonzero if the clock chip battery is low. */
static __inline__ int has_low_battery(void)
{
struct mostek48t02 *regs = (struct mostek48t02 *)mstk48t02_regs;
unsigned char data1, data2;
spin_lock_irq(&mostek_lock);
data1 = regs->eeprom[0]; /* Read some data. */
regs->eeprom[0] = ~data1; /* Write back the complement. */
data2 = regs->eeprom[0]; /* Read back the complement. */
regs->eeprom[0] = data1; /* Restore the original value. */
spin_unlock_irq(&mostek_lock);
return (data1 == data2); /* Was the write blocked? */
}
static void __init mostek_set_system_time(void)
{
unsigned int year, mon, day, hour, min, sec;
struct mostek48t02 *mregs;
mregs = (struct mostek48t02 *)mstk48t02_regs;
if(!mregs) {
prom_printf("Something wrong, clock regs not mapped yet.\n");
prom_halt();
}
spin_lock_irq(&mostek_lock);
mregs->creg |= MSTK_CREG_READ;
sec = MSTK_REG_SEC(mregs);
min = MSTK_REG_MIN(mregs);
hour = MSTK_REG_HOUR(mregs);
day = MSTK_REG_DOM(mregs);
mon = MSTK_REG_MONTH(mregs);
year = MSTK_CVT_YEAR( MSTK_REG_YEAR(mregs) );
xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
set_normalized_timespec(&wall_to_monotonic,
-xtime.tv_sec, -xtime.tv_nsec);
mregs->creg &= ~MSTK_CREG_READ;
spin_unlock_irq(&mostek_lock);
}
/* Probe for the real time clock chip on Sun4 */
static __inline__ void sun4_clock_probe(void)
{
#ifdef CONFIG_SUN4
int temp;
struct resource r;
memset(&r, 0, sizeof(r));
if( idprom->id_machtype == (SM_SUN4 | SM_4_330) ) {
sp_clock_typ = MSTK48T02;
r.start = sun4_clock_physaddr;
mstk48t02_regs = sbus_ioremap(&r, 0,
sizeof(struct mostek48t02), NULL);
mstk48t08_regs = NULL; /* To catch weirdness */
intersil_clock = NULL; /* just in case */
/* Kick start the clock if it is completely stopped. */
if (mostek_read(mstk48t02_regs + MOSTEK_SEC) & MSTK_STOP)
kick_start_clock();
} else if( idprom->id_machtype == (SM_SUN4 | SM_4_260)) {
/* intersil setup code */
printk("Clock: INTERSIL at %8x ",sun4_clock_physaddr);
sp_clock_typ = INTERSIL;
r.start = sun4_clock_physaddr;
intersil_clock = (struct intersil *)
sbus_ioremap(&r, 0, sizeof(*intersil_clock), "intersil");
mstk48t02_regs = 0; /* just be sure */
mstk48t08_regs = NULL; /* ditto */
/* initialise the clock */
intersil_intr(intersil_clock,INTERSIL_INT_100HZ);
intersil_start(intersil_clock);
intersil_read_intr(intersil_clock, temp);
while (!(temp & 0x80))
intersil_read_intr(intersil_clock, temp);
intersil_read_intr(intersil_clock, temp);
while (!(temp & 0x80))
intersil_read_intr(intersil_clock, temp);
intersil_stop(intersil_clock);
}
#endif
}
#ifndef CONFIG_SUN4
static int __devinit clock_probe(struct of_device *op, const struct of_device_id *match)
{
struct device_node *dp = op->node;
char *model = of_get_property(dp, "model", NULL);
if (!model)
return -ENODEV;
if (!strcmp(model, "mk48t02")) {
sp_clock_typ = MSTK48T02;
/* Map the clock register io area read-only */
mstk48t02_regs = of_ioremap(&op->resource[0], 0,
sizeof(struct mostek48t02),
"mk48t02");
mstk48t08_regs = NULL; /* To catch weirdness */
} else if (!strcmp(model, "mk48t08")) {
sp_clock_typ = MSTK48T08;
mstk48t08_regs = of_ioremap(&op->resource[0], 0,
sizeof(struct mostek48t08),
"mk48t08");
mstk48t02_regs = &mstk48t08_regs->regs;
} else
return -ENODEV;
/* Report a low battery voltage condition. */
if (has_low_battery())
printk(KERN_CRIT "NVRAM: Low battery voltage!\n");
/* Kick start the clock if it is completely stopped. */
if (mostek_read(mstk48t02_regs + MOSTEK_SEC) & MSTK_STOP)
kick_start_clock();
mostek_set_system_time();
return 0;
}
static struct of_device_id clock_match[] = {
{
.name = "eeprom",
},
{},
};
static struct of_platform_driver clock_driver = {
.name = "clock",
.match_table = clock_match,
.probe = clock_probe,
};
/* Probe for the mostek real time clock chip. */
static int __init clock_init(void)
{
return of_register_driver(&clock_driver, &of_bus_type);
}
/* Must be after subsys_initcall() so that busses are probed. Must
* be before device_initcall() because things like the RTC driver
* need to see the clock registers.
*/
fs_initcall(clock_init);
#endif /* !CONFIG_SUN4 */
void __init sbus_time_init(void)
{
BTFIXUPSET_CALL(bus_do_settimeofday, sbus_do_settimeofday, BTFIXUPCALL_NORM);
btfixup();
if (ARCH_SUN4)
sun4_clock_probe();
sparc_init_timers(timer_interrupt);
#ifdef CONFIG_SUN4
if(idprom->id_machtype == (SM_SUN4 | SM_4_330)) {
mostek_set_system_time();
} else if(idprom->id_machtype == (SM_SUN4 | SM_4_260) ) {
/* initialise the intersil on sun4 */
unsigned int year, mon, day, hour, min, sec;
int temp;
struct intersil *iregs;
iregs=intersil_clock;
if(!iregs) {
prom_printf("Something wrong, clock regs not mapped yet.\n");
prom_halt();
}
intersil_intr(intersil_clock,INTERSIL_INT_100HZ);
disable_pil_irq(10);
intersil_stop(iregs);
intersil_read_intr(intersil_clock, temp);
temp = iregs->clk.int_csec;
sec = iregs->clk.int_sec;
min = iregs->clk.int_min;
hour = iregs->clk.int_hour;
day = iregs->clk.int_day;
mon = iregs->clk.int_month;
year = MSTK_CVT_YEAR(iregs->clk.int_year);
enable_pil_irq(10);
intersil_start(iregs);
xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
set_normalized_timespec(&wall_to_monotonic,
-xtime.tv_sec, -xtime.tv_nsec);
printk("%u/%u/%u %u:%u:%u\n",day,mon,year,hour,min,sec);
}
#endif
/* Now that OBP ticker has been silenced, it is safe to enable IRQ. */
local_irq_enable();
}
void __init time_init(void)
{
#ifdef CONFIG_PCI
extern void pci_time_init(void);
if (pcic_present()) {
pci_time_init();
return;
}
#endif
sbus_time_init();
}
static inline unsigned long do_gettimeoffset(void)
{
return (*master_l10_counter >> 10) & 0x1fffff;
}
/*
* Returns nanoseconds
* XXX This is a suboptimal implementation.
*/
unsigned long long sched_clock(void)
{
return (unsigned long long)jiffies * (1000000000 / HZ);
}
/* Ok, my cute asm atomicity trick doesn't work anymore.
* There are just too many variables that need to be protected
* now (both members of xtime, et al.)
*/
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
unsigned long seq;
unsigned long usec, sec;
unsigned long max_ntp_tick = tick_usec - tickadj;
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
usec = do_gettimeoffset();
/*
* If time_adjust is negative then NTP is slowing the clock
* so make sure not to go into next possible interval.
* Better to lose some accuracy than have time go backwards..
*/
if (unlikely(time_adjust < 0))
usec = min(usec, max_ntp_tick);
sec = xtime.tv_sec;
usec += (xtime.tv_nsec / 1000);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
while (usec >= 1000000) {
usec -= 1000000;
sec++;
}
tv->tv_sec = sec;
tv->tv_usec = usec;
}
EXPORT_SYMBOL(do_gettimeofday);
int do_settimeofday(struct timespec *tv)
{
int ret;
write_seqlock_irq(&xtime_lock);
ret = bus_do_settimeofday(tv);
write_sequnlock_irq(&xtime_lock);
clock_was_set();
return ret;
}
EXPORT_SYMBOL(do_settimeofday);
static int sbus_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;
/*
* 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();
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();
return 0;
}
/*
* BUG: This routine does not handle hour overflow properly; it just
* sets the minutes. Usually you won't notice until after reboot!
*/
static int set_rtc_mmss(unsigned long nowtime)
{
int real_seconds, real_minutes, mostek_minutes;
struct mostek48t02 *regs = (struct mostek48t02 *)mstk48t02_regs;
unsigned long flags;
#ifdef CONFIG_SUN4
struct intersil *iregs = intersil_clock;
int temp;
#endif
/* Not having a register set can lead to trouble. */
if (!regs) {
#ifdef CONFIG_SUN4
if(!iregs)
return -1;
else {
temp = iregs->clk.int_csec;
mostek_minutes = iregs->clk.int_min;
real_seconds = nowtime % 60;
real_minutes = nowtime / 60;
if (((abs(real_minutes - mostek_minutes) + 15)/30) & 1)
real_minutes += 30; /* correct for half hour time zone */
real_minutes %= 60;
if (abs(real_minutes - mostek_minutes) < 30) {
intersil_stop(iregs);
iregs->clk.int_sec=real_seconds;
iregs->clk.int_min=real_minutes;
intersil_start(iregs);
} else {
printk(KERN_WARNING
"set_rtc_mmss: can't update from %d to %d\n",
mostek_minutes, real_minutes);
return -1;
}
return 0;
}
#endif
}
spin_lock_irqsave(&mostek_lock, flags);
/* Read the current RTC minutes. */
regs->creg |= MSTK_CREG_READ;
mostek_minutes = MSTK_REG_MIN(regs);
regs->creg &= ~MSTK_CREG_READ;
/*
* since we're only adjusting minutes and seconds,
* don't interfere with hour overflow. This avoids
* messing with unknown time zones but requires your
* RTC not to be off by more than 15 minutes
*/
real_seconds = nowtime % 60;
real_minutes = nowtime / 60;
if (((abs(real_minutes - mostek_minutes) + 15)/30) & 1)
real_minutes += 30; /* correct for half hour time zone */
real_minutes %= 60;
if (abs(real_minutes - mostek_minutes) < 30) {
regs->creg |= MSTK_CREG_WRITE;
MSTK_SET_REG_SEC(regs,real_seconds);
MSTK_SET_REG_MIN(regs,real_minutes);
regs->creg &= ~MSTK_CREG_WRITE;
spin_unlock_irqrestore(&mostek_lock, flags);
return 0;
} else {
spin_unlock_irqrestore(&mostek_lock, flags);
return -1;
}
}
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