kernel-ark/arch/ppc64/kernel/maple_time.c
Arnd Bergmann 10f7e7c15e [PATCH] ppc64: consolidate calibrate_decr implementations
pSeries and maple have almost the same code for calibrate_decr,
and BPA would need yet another copy. Instead, I'm moving the
code to arch/ppc64/kernel/time.c.

Some of the related declarations were missing from header
files, so I'm moving those as well.

It makes sense to merge this with the pmac function of the
same name, so we end up having just one implemetation for
iSeries and one for Open Firmware based machines.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-06-23 09:43:07 +10:00

176 lines
4.7 KiB
C

/*
* arch/ppc64/kernel/maple_time.c
*
* (c) Copyright 2004 Benjamin Herrenschmidt (benh@kernel.crashing.org),
* IBM Corp.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
*/
#undef DEBUG
#include <linux/config.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/time.h>
#include <linux/adb.h>
#include <linux/pmu.h>
#include <linux/interrupt.h>
#include <linux/mc146818rtc.h>
#include <linux/bcd.h>
#include <asm/sections.h>
#include <asm/prom.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/machdep.h>
#include <asm/time.h>
#ifdef DEBUG
#define DBG(x...) printk(x)
#else
#define DBG(x...)
#endif
extern void GregorianDay(struct rtc_time * tm);
static int maple_rtc_addr;
static int maple_clock_read(int addr)
{
outb_p(addr, maple_rtc_addr);
return inb_p(maple_rtc_addr+1);
}
static void maple_clock_write(unsigned long val, int addr)
{
outb_p(addr, maple_rtc_addr);
outb_p(val, maple_rtc_addr+1);
}
void maple_get_rtc_time(struct rtc_time *tm)
{
int uip, i;
/* The Linux interpretation of the CMOS clock register contents:
* When the Update-In-Progress (UIP) flag goes from 1 to 0, the
* RTC registers show the second which has precisely just started.
* Let's hope other operating systems interpret the RTC the same way.
*/
/* Since the UIP flag is set for about 2.2 ms and the clock
* is typically written with a precision of 1 jiffy, trying
* to obtain a precision better than a few milliseconds is
* an illusion. Only consistency is interesting, this also
* allows to use the routine for /dev/rtc without a potential
* 1 second kernel busy loop triggered by any reader of /dev/rtc.
*/
for (i = 0; i<1000000; i++) {
uip = maple_clock_read(RTC_FREQ_SELECT);
tm->tm_sec = maple_clock_read(RTC_SECONDS);
tm->tm_min = maple_clock_read(RTC_MINUTES);
tm->tm_hour = maple_clock_read(RTC_HOURS);
tm->tm_mday = maple_clock_read(RTC_DAY_OF_MONTH);
tm->tm_mon = maple_clock_read(RTC_MONTH);
tm->tm_year = maple_clock_read(RTC_YEAR);
uip |= maple_clock_read(RTC_FREQ_SELECT);
if ((uip & RTC_UIP)==0)
break;
}
if (!(maple_clock_read(RTC_CONTROL) & RTC_DM_BINARY)
|| RTC_ALWAYS_BCD) {
BCD_TO_BIN(tm->tm_sec);
BCD_TO_BIN(tm->tm_min);
BCD_TO_BIN(tm->tm_hour);
BCD_TO_BIN(tm->tm_mday);
BCD_TO_BIN(tm->tm_mon);
BCD_TO_BIN(tm->tm_year);
}
if ((tm->tm_year + 1900) < 1970)
tm->tm_year += 100;
GregorianDay(tm);
}
int maple_set_rtc_time(struct rtc_time *tm)
{
unsigned char save_control, save_freq_select;
int sec, min, hour, mon, mday, year;
spin_lock(&rtc_lock);
save_control = maple_clock_read(RTC_CONTROL); /* tell the clock it's being set */
maple_clock_write((save_control|RTC_SET), RTC_CONTROL);
save_freq_select = maple_clock_read(RTC_FREQ_SELECT); /* stop and reset prescaler */
maple_clock_write((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
sec = tm->tm_sec;
min = tm->tm_min;
hour = tm->tm_hour;
mon = tm->tm_mon;
mday = tm->tm_mday;
year = tm->tm_year;
if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
BIN_TO_BCD(sec);
BIN_TO_BCD(min);
BIN_TO_BCD(hour);
BIN_TO_BCD(mon);
BIN_TO_BCD(mday);
BIN_TO_BCD(year);
}
maple_clock_write(sec, RTC_SECONDS);
maple_clock_write(min, RTC_MINUTES);
maple_clock_write(hour, RTC_HOURS);
maple_clock_write(mon, RTC_MONTH);
maple_clock_write(mday, RTC_DAY_OF_MONTH);
maple_clock_write(year, RTC_YEAR);
/* The following flags have to be released exactly in this order,
* otherwise the DS12887 (popular MC146818A clone with integrated
* battery and quartz) will not reset the oscillator and will not
* update precisely 500 ms later. You won't find this mentioned in
* the Dallas Semiconductor data sheets, but who believes data
* sheets anyway ... -- Markus Kuhn
*/
maple_clock_write(save_control, RTC_CONTROL);
maple_clock_write(save_freq_select, RTC_FREQ_SELECT);
spin_unlock(&rtc_lock);
return 0;
}
void __init maple_get_boot_time(struct rtc_time *tm)
{
struct device_node *rtcs;
rtcs = find_compatible_devices("rtc", "pnpPNP,b00");
if (rtcs && rtcs->addrs) {
maple_rtc_addr = rtcs->addrs[0].address;
printk(KERN_INFO "Maple: Found RTC at 0x%x\n", maple_rtc_addr);
} else {
maple_rtc_addr = RTC_PORT(0); /* legacy address */
printk(KERN_INFO "Maple: No device node for RTC, assuming "
"legacy address (0x%x)\n", maple_rtc_addr);
}
maple_get_rtc_time(tm);
}