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x86: share rtc code

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Remove the rtc code from time_64.c and add the extra bits to the
i386 path. The ACPI century check is probably valid for i386 as
well, but this is material for a separate patch.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Thomas Gleixner
2008-01-30 13:30:27 +01:00
committed by Ingo Molnar
parent fe599f9fbc
commit 1122b134bc
3 changed files with 62 additions and 189 deletions
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92
arch/x86/kernel/rtc.c
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@ -1,11 +1,32 @@
/*
* RTC related functions
*/
#include <linux/acpi.h>
#include <linux/bcd.h>
#include <linux/mc146818rtc.h>
#include <asm/time.h>
#ifdef CONFIG_X86_32
# define CMOS_YEARS_OFFS 1900
/*
* This is a special lock that is owned by the CPU and holds the index
* register we are working with. It is required for NMI access to the
* CMOS/RTC registers. See include/asm-i386/mc146818rtc.h for details.
*/
volatile unsigned long cmos_lock = 0;
EXPORT_SYMBOL(cmos_lock);
#else
/*
* x86-64 systems only exists since 2002.
* This will work up to Dec 31, 2100
*/
# define CMOS_YEARS_OFFS 2000
#endif
DEFINE_SPINLOCK(rtc_lock);
EXPORT_SYMBOL(rtc_lock);
/*
* In order to set the CMOS clock precisely, set_rtc_mmss has to be
* called 500 ms after the second nowtime has started, because when
@ -22,10 +43,12 @@ int mach_set_rtc_mmss(unsigned long nowtime)
int real_seconds, real_minutes, cmos_minutes;
unsigned char save_control, save_freq_select;
save_control = CMOS_READ(RTC_CONTROL); /* tell the clock it's being set */
/* tell the clock it's being set */
save_control = CMOS_READ(RTC_CONTROL);
CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL);
save_freq_select = CMOS_READ(RTC_FREQ_SELECT); /* stop and reset prescaler */
/* stop and reset prescaler */
save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
cmos_minutes = CMOS_READ(RTC_MINUTES);
@ -40,8 +63,9 @@ int mach_set_rtc_mmss(unsigned long nowtime)
*/
real_seconds = nowtime % 60;
real_minutes = nowtime / 60;
/* correct for half hour time zone */
if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1)
real_minutes += 30; /* correct for half hour time zone */
real_minutes += 30;
real_minutes %= 60;
if (abs(real_minutes - cmos_minutes) < 30) {
@ -73,18 +97,32 @@ int mach_set_rtc_mmss(unsigned long nowtime)
unsigned long mach_get_cmos_time(void)
{
unsigned int year, mon, day, hour, min, sec;
unsigned int year, mon, day, hour, min, sec, century = 0;
do {
sec = CMOS_READ(RTC_SECONDS);
min = CMOS_READ(RTC_MINUTES);
hour = CMOS_READ(RTC_HOURS);
day = CMOS_READ(RTC_DAY_OF_MONTH);
mon = CMOS_READ(RTC_MONTH);
year = CMOS_READ(RTC_YEAR);
} while (sec != CMOS_READ(RTC_SECONDS));
/*
* If UIP is clear, then we have >= 244 microseconds before
* RTC registers will be updated. Spec sheet says that this
* is the reliable way to read RTC - registers. If UIP is set
* then the register access might be invalid.
*/
while ((CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP))
cpu_relax();
if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
sec = CMOS_READ(RTC_SECONDS);
min = CMOS_READ(RTC_MINUTES);
hour = CMOS_READ(RTC_HOURS);
day = CMOS_READ(RTC_DAY_OF_MONTH);
mon = CMOS_READ(RTC_MONTH);
year = CMOS_READ(RTC_YEAR);
#if defined(CONFIG_ACPI) && defined(CONFIG_X86_64)
/* CHECKME: Is this really 64bit only ??? */
if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID &&
acpi_gbl_FADT.century)
century = CMOS_READ(acpi_gbl_FADT.century);
#endif
if (RTC_ALWAYS_BCD || !(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY)) {
BCD_TO_BIN(sec);
BCD_TO_BIN(min);
BCD_TO_BIN(hour);
@ -93,24 +131,19 @@ unsigned long mach_get_cmos_time(void)
BCD_TO_BIN(year);
}
year += 1900;
if (year < 1970)
year += 100;
if (century) {
BCD_TO_BIN(century);
year += century * 100;
printk(KERN_INFO "Extended CMOS year: %d\n", century * 100);
} else {
year += CMOS_YEARS_OFFS;
if (year < 1970)
year += 100;
}
return mktime(year, mon, day, hour, min, sec);
}
DEFINE_SPINLOCK(rtc_lock);
EXPORT_SYMBOL(rtc_lock);
/*
* This is a special lock that is owned by the CPU and holds the index
* register we are working with. It is required for NMI access to the
* CMOS/RTC registers. See include/asm-i386/mc146818rtc.h for details.
*/
volatile unsigned long cmos_lock = 0;
EXPORT_SYMBOL(cmos_lock);
/* Routines for accessing the CMOS RAM/RTC. */
unsigned char rtc_cmos_read(unsigned char addr)
{
@ -138,8 +171,6 @@ static int set_rtc_mmss(unsigned long nowtime)
int retval;
unsigned long flags;
/* gets recalled with irq locally disabled */
/* XXX - does irqsave resolve this? -johnstul */
spin_lock_irqsave(&rtc_lock, flags);
retval = set_wallclock(nowtime);
spin_unlock_irqrestore(&rtc_lock, flags);
@ -150,8 +181,7 @@ static int set_rtc_mmss(unsigned long nowtime)
/* not static: needed by APM */
unsigned long read_persistent_clock(void)
{
unsigned long retval;
unsigned long flags;
unsigned long retval, flags;
spin_lock_irqsave(&rtc_lock, flags);
retval = get_wallclock();