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/****************************************************************************/
/*
* linux/arch/sh/boards/snapgear/rtc.c -- Secureedge5410 RTC code
*
* Copyright (C) 2002 David McCullough <davidm@snapgear.com>
* Copyright (C) 2003 Paul Mundt <lethal@linux-sh.org>
*
* The SecureEdge5410 can have one of 2 real time clocks, the SH
* built in version or the preferred external DS1302. Here we work out
* each to see what we have and then run with it.
*/
/****************************************************************************/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/time.h>
#include <linux/rtc.h>
#include <linux/mc146818rtc.h>
#include <asm/io.h>
static int use_ds1302;
/****************************************************************************/
/*
* we need to implement a DS1302 driver here that can operate in
* conjunction with the builtin rtc driver which is already quite friendly
*/
/*****************************************************************************/
#define RTC_CMD_READ 0x81 /* Read command */
#define RTC_CMD_WRITE 0x80 /* Write command */
#define RTC_ADDR_YEAR 0x06 /* Address of year register */
#define RTC_ADDR_DAY 0x05 /* Address of day of week register */
#define RTC_ADDR_MON 0x04 /* Address of month register */
#define RTC_ADDR_DATE 0x03 /* Address of day of month register */
#define RTC_ADDR_HOUR 0x02 /* Address of hour register */
#define RTC_ADDR_MIN 0x01 /* Address of minute register */
#define RTC_ADDR_SEC 0x00 /* Address of second register */
#define RTC_RESET 0x1000
#define RTC_IODATA 0x0800
#define RTC_SCLK 0x0400
#define set_dirp(x)
#define get_dirp(x) 0
#define set_dp(x) SECUREEDGE_WRITE_IOPORT(x, 0x1c00)
#define get_dp(x) SECUREEDGE_READ_IOPORT()
static void ds1302_sendbits(unsigned int val)
{
int i;
for (i = 8; (i); i--, val >>= 1) {
set_dp((get_dp() & ~RTC_IODATA) | ((val & 0x1) ? RTC_IODATA : 0));
set_dp(get_dp() | RTC_SCLK); // clock high
set_dp(get_dp() & ~RTC_SCLK); // clock low
}
}
static unsigned int ds1302_recvbits(void)
{
unsigned int val;
int i;
for (i = 0, val = 0; (i < 8); i++) {
val |= (((get_dp() & RTC_IODATA) ? 1 : 0) << i);
set_dp(get_dp() | RTC_SCLK); // clock high
set_dp(get_dp() & ~RTC_SCLK); // clock low
}
return(val);
}
static unsigned int ds1302_readbyte(unsigned int addr)
{
unsigned int val;
unsigned long flags;
local_irq_save(flags);
set_dirp(get_dirp() | RTC_RESET | RTC_IODATA | RTC_SCLK);
set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK));
set_dp(get_dp() | RTC_RESET);
ds1302_sendbits(((addr & 0x3f) << 1) | RTC_CMD_READ);
set_dirp(get_dirp() & ~RTC_IODATA);
val = ds1302_recvbits();
set_dp(get_dp() & ~RTC_RESET);
local_irq_restore(flags);
return(val);
}
static void ds1302_writebyte(unsigned int addr, unsigned int val)
{
unsigned long flags;
local_irq_save(flags);
set_dirp(get_dirp() | RTC_RESET | RTC_IODATA | RTC_SCLK);
set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK));
set_dp(get_dp() | RTC_RESET);
ds1302_sendbits(((addr & 0x3f) << 1) | RTC_CMD_WRITE);
ds1302_sendbits(val);
set_dp(get_dp() & ~RTC_RESET);
local_irq_restore(flags);
}
static void ds1302_reset(void)
{
unsigned long flags;
/* Hardware dependent reset/init */
local_irq_save(flags);
set_dirp(get_dirp() | RTC_RESET | RTC_IODATA | RTC_SCLK);
set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK));
local_irq_restore(flags);
}
/*****************************************************************************/
static inline int bcd2int(int val)
{
return((((val & 0xf0) >> 4) * 10) + (val & 0xf));
}
static inline int int2bcd(int val)
{
return(((val / 10) << 4) + (val % 10));
}
/*****************************************************************************/
/*
* Write and Read some RAM in the DS1302, if it works assume it's there
* Otherwise use the SH4 internal RTC
*/
void snapgear_rtc_gettimeofday(struct timespec *);
int snapgear_rtc_settimeofday(const time_t);
void __init secureedge5410_rtc_init(void)
{
unsigned char *test = "snapgear";
int i;
ds1302_reset();
use_ds1302 = 1;
for (i = 0; test[i]; i++)
ds1302_writebyte(32 + i, test[i]);
for (i = 0; test[i]; i++)
if (ds1302_readbyte(32 + i) != test[i]) {
use_ds1302 = 0;
break;
}
if (use_ds1302) {
rtc_sh_get_time = snapgear_rtc_gettimeofday;
rtc_sh_set_time = snapgear_rtc_settimeofday;
}
printk("SnapGear RTC: using %s rtc.\n", use_ds1302 ? "ds1302" : "internal");
}
/****************************************************************************/
/*
* our generic interface that chooses the correct code to use
*/
void snapgear_rtc_gettimeofday(struct timespec *ts)
{
unsigned int sec, min, hr, day, mon, yr;
if (!use_ds1302)
return;
sec = bcd2int(ds1302_readbyte(RTC_ADDR_SEC));
min = bcd2int(ds1302_readbyte(RTC_ADDR_MIN));
hr = bcd2int(ds1302_readbyte(RTC_ADDR_HOUR));
day = bcd2int(ds1302_readbyte(RTC_ADDR_DATE));
mon = bcd2int(ds1302_readbyte(RTC_ADDR_MON));
yr = bcd2int(ds1302_readbyte(RTC_ADDR_YEAR));
bad_time:
if (yr > 99 || mon < 1 || mon > 12 || day > 31 || day < 1 ||
hr > 23 || min > 59 || sec > 59) {
printk(KERN_ERR
"SnapGear RTC: invalid value, resetting to 1 Jan 2000\n");
ds1302_writebyte(RTC_ADDR_MIN, min = 0);
ds1302_writebyte(RTC_ADDR_HOUR, hr = 0);
ds1302_writebyte(RTC_ADDR_DAY, 7);
ds1302_writebyte(RTC_ADDR_DATE, day = 1);
ds1302_writebyte(RTC_ADDR_MON, mon = 1);
ds1302_writebyte(RTC_ADDR_YEAR, yr = 0);
ds1302_writebyte(RTC_ADDR_SEC, sec = 0);
}
ts->tv_sec = mktime(2000 + yr, mon, day, hr, min, sec);
if (ts->tv_sec < 0) {
#if 0
printk("BAD TIME %d %d %d %d %d %d\n", yr, mon, day, hr, min, sec);
#endif
yr = 100;
goto bad_time;
}
ts->tv_nsec = 0;
}
int snapgear_rtc_settimeofday(const time_t secs)
{
int retval = 0;
int real_seconds, real_minutes, cmos_minutes;
unsigned long nowtime;
if (!use_ds1302)
return 0;
/*
* This is called direct from the kernel timer handling code.
* It is supposed to synchronize the kernel clock to the RTC.
*/
nowtime = secs;
/* STOP RTC */
ds1302_writebyte(RTC_ADDR_SEC, ds1302_readbyte(RTC_ADDR_SEC) | 0x80);
cmos_minutes = bcd2int(ds1302_readbyte(RTC_ADDR_MIN));
/*
* 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 - cmos_minutes) + 15)/30) & 1)
real_minutes += 30; /* correct for half hour time zone */
real_minutes %= 60;
if (abs(real_minutes - cmos_minutes) < 30) {
ds1302_writebyte(RTC_ADDR_MIN, int2bcd(real_minutes));
ds1302_writebyte(RTC_ADDR_SEC, int2bcd(real_seconds));
} else {
printk(KERN_WARNING
"SnapGear RTC: can't update from %d to %d\n",
cmos_minutes, real_minutes);
retval = -1;
}
/* START RTC */
ds1302_writebyte(RTC_ADDR_SEC, ds1302_readbyte(RTC_ADDR_SEC) & ~0x80);
return(0);
}
unsigned char secureedge5410_cmos_read(int addr)
{
unsigned char val = 0;
if (!use_ds1302)
return(__CMOS_READ(addr, w));
switch(addr) {
case RTC_SECONDS: val = ds1302_readbyte(RTC_ADDR_SEC); break;
case RTC_SECONDS_ALARM: break;
case RTC_MINUTES: val = ds1302_readbyte(RTC_ADDR_MIN); break;
case RTC_MINUTES_ALARM: break;
case RTC_HOURS: val = ds1302_readbyte(RTC_ADDR_HOUR); break;
case RTC_HOURS_ALARM: break;
case RTC_DAY_OF_WEEK: val = ds1302_readbyte(RTC_ADDR_DAY); break;
case RTC_DAY_OF_MONTH: val = ds1302_readbyte(RTC_ADDR_DATE); break;
case RTC_MONTH: val = ds1302_readbyte(RTC_ADDR_MON); break;
case RTC_YEAR: val = ds1302_readbyte(RTC_ADDR_YEAR); break;
case RTC_REG_A: /* RTC_FREQ_SELECT */ break;
case RTC_REG_B: /* RTC_CONTROL */ break;
case RTC_REG_C: /* RTC_INTR_FLAGS */ break;
case RTC_REG_D: val = RTC_VRT /* RTC_VALID */; break;
default: break;
}
return(val);
}
void secureedge5410_cmos_write(unsigned char val, int addr)
{
if (!use_ds1302) {
__CMOS_WRITE(val, addr, w);
return;
}
switch(addr) {
case RTC_SECONDS: ds1302_writebyte(RTC_ADDR_SEC, val); break;
case RTC_SECONDS_ALARM: break;
case RTC_MINUTES: ds1302_writebyte(RTC_ADDR_MIN, val); break;
case RTC_MINUTES_ALARM: break;
case RTC_HOURS: ds1302_writebyte(RTC_ADDR_HOUR, val); break;
case RTC_HOURS_ALARM: break;
case RTC_DAY_OF_WEEK: ds1302_writebyte(RTC_ADDR_DAY, val); break;
case RTC_DAY_OF_MONTH: ds1302_writebyte(RTC_ADDR_DATE, val); break;
case RTC_MONTH: ds1302_writebyte(RTC_ADDR_MON, val); break;
case RTC_YEAR: ds1302_writebyte(RTC_ADDR_YEAR, val); break;
case RTC_REG_A: /* RTC_FREQ_SELECT */ break;
case RTC_REG_B: /* RTC_CONTROL */ break;
case RTC_REG_C: /* RTC_INTR_FLAGS */ break;
case RTC_REG_D: /* RTC_VALID */ break;
default: break;
}
}
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