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sparc32: use RTC subsystem
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Use rtc subsystem for sparc32 architecture.
Actually, only one driver is needed: m48t59
as it supports the most common clocks on sparc32
machines: m48t08 and m48t02.

[ Add proper RTC layer calls to set_rtc_mmss() -DaveM ]

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
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David S. Miller committed Sep 3, 2008
1 parent 64151ad commit c4cbe6f
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Showing 3 changed files with 62 additions and 159 deletions.
2 changes: 2 additions & 0 deletions arch/sparc/Kconfig
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Original file line number Diff line number Diff line change
Expand Up @@ -75,6 +75,8 @@ config SPARC
select HAVE_ARCH_KGDB if !SMP
select HAVE_ARCH_TRACEHOOK
select ARCH_WANT_OPTIONAL_GPIOLIB
select RTC_CLASS
select RTC_DRV_M48T59

# Identify this as a Sparc32 build
config SPARC32
Expand Down
2 changes: 0 additions & 2 deletions arch/sparc/kernel/sparc_ksyms.c
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Original file line number Diff line number Diff line change
Expand Up @@ -123,8 +123,6 @@ EXPORT_SYMBOL(phys_cpu_present_map);
EXPORT_SYMBOL(__udelay);
EXPORT_SYMBOL(__ndelay);
EXPORT_SYMBOL(rtc_lock);
EXPORT_SYMBOL(mostek_lock);
EXPORT_SYMBOL(mstk48t02_regs);
#ifdef CONFIG_SUN_AUXIO
EXPORT_SYMBOL(set_auxio);
EXPORT_SYMBOL(get_auxio);
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217 changes: 60 additions & 157 deletions arch/sparc/kernel/time.c
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Original file line number Diff line number Diff line change
Expand Up @@ -23,17 +23,19 @@
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/time.h>
#include <linux/rtc.h>
#include <linux/rtc/m48t59.h>
#include <linux/timex.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/ioport.h>
#include <linux/profile.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.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>
Expand All @@ -46,10 +48,6 @@
#include "irq.h"

DEFINE_SPINLOCK(rtc_lock);
static 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);

Expand Down Expand Up @@ -118,107 +116,55 @@ static irqreturn_t timer_interrupt(int dummy, void *dev_id)
return IRQ_HANDLED;
}

/* Kick start a stopped clock (procedure from the Sun NVRAM/hostid FAQ). */
static void __devinit kick_start_clock(void)
static unsigned char mostek_read_byte(struct device *dev, u32 ofs)
{
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;
struct platform_device *pdev = to_platform_device(dev);
struct m48t59_plat_data *pdata = pdev->dev.platform_data;
void __iomem *regs = pdata->ioaddr;
unsigned char val = readb(regs + ofs);

/* the year 0 is 1968 */
if (ofs == pdata->offset + M48T59_YEAR) {
val += 0x68;
if ((val & 0xf) > 9)
val += 6;
}
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 val;
}

/* Return nonzero if the clock chip battery is low. */
static inline int has_low_battery(void)
static void mostek_write_byte(struct device *dev, u32 ofs, u8 val)
{
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? */
struct platform_device *pdev = to_platform_device(dev);
struct m48t59_plat_data *pdata = pdev->dev.platform_data;
void __iomem *regs = pdata->ioaddr;

if (ofs == pdata->offset + M48T59_YEAR) {
if (val < 0x68)
val += 0x32;
else
val -= 0x68;
if ((val & 0xf) > 9)
val += 6;
if ((val & 0xf0) > 0x9A)
val += 0x60;
}
writeb(val, regs + ofs);
}

static void __devinit 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);
}
static struct m48t59_plat_data m48t59_data = {
.read_byte = mostek_read_byte,
.write_byte = mostek_write_byte,
};

/* resource is set at runtime */
static struct platform_device m48t59_rtc = {
.name = "rtc-m48t59",
.id = 0,
.num_resources = 1,
.dev = {
.platform_data = &m48t59_data,
},
};

static int __devinit clock_probe(struct of_device *op, const struct of_device_id *match)
{
Expand All @@ -228,33 +174,21 @@ static int __devinit clock_probe(struct of_device *op, const struct of_device_id
if (!model)
return -ENODEV;

m48t59_rtc.resource = &op->resource[0];
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 */
m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0,
2048, "rtc-m48t59");
m48t59_data.type = M48T59RTC_TYPE_M48T02;
} 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;
m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0,
8192, "rtc-m48t59");
m48t59_data.type = M48T59RTC_TYPE_M48T08;
} 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();
if (platform_device_register(&m48t59_rtc) < 0)
printk(KERN_ERR "Registering RTC device failed\n");

return 0;
}
Expand All @@ -270,7 +204,7 @@ static struct of_platform_driver clock_driver = {
.match_table = clock_match,
.probe = clock_probe,
.driver = {
.name = "clock",
.name = "rtc",
},
};

Expand Down Expand Up @@ -400,43 +334,12 @@ static int sbus_do_settimeofday(struct timespec *tv)
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)
static int set_rtc_mmss(unsigned long secs)
{
int real_seconds, real_minutes, mostek_minutes;
struct mostek48t02 *regs = (struct mostek48t02 *)mstk48t02_regs;
unsigned long flags;
struct rtc_device *rtc = rtc_class_open("rtc0");

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;
if (rtc)
return rtc_set_mmss(rtc, secs);

/*
* 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;
}
return -1;
}

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