void m48_watchdog_arm(int usec)
{
int mpy, res;
SYS_TOD_UNPROTECT();
if (usec == 0) {
res = 0;
mpy = 0;
} else if (usec < 2000000) { /* Resolution: 1/16s if below 2s */
res = 0;
mpy = (usec + 62499) / 62500;
} else if (usec < 8000000) { /* Resolution: 1/4s if below 8s */
res = 1;
mpy = (usec + 249999) / 250000;
} else if (usec < 32000000) { /* Resolution: 1s if below 32s */
res = 2;
mpy = (usec + 999999) / 1000000;
} else { /* Resolution: 4s up to 124s */
res = 3;
mpy = (usec + 3999999) / 4000000;
if (mpy > 31)
mpy = 31;
}
M48_ADDR[WATCH] = (0x80 | /* Steer to RST signal (IRQ = N/C) */
mpy << 2 |
res);
SYS_TOD_PROTECT();
}
int m48_tod_get(int *year, /* 1980-2079 */
int *month, /* 01-12 */
int *day, /* 01-31 */
int *hour, /* 00-23 */
int *minute, /* 00-59 */
int *second) /* 00-59 */
{
int y;
SYS_TOD_UNPROTECT();
M48_ADDR[CONTROL] |= 0x40; /* Set READ bit */
y = from_bcd(M48_ADDR[YEAR]);
*year = y < 80 ? 2000 + y : 1900 + y;
*month = from_bcd(M48_ADDR[MONTH]);
*day = from_bcd(M48_ADDR[DAY]);
/* day_of_week = M48_ADDR[DAY_OF_WEEK] & 0xf; */
*hour = from_bcd(M48_ADDR[HOUR]);
*minute = from_bcd(M48_ADDR[MINUTE]);
*second = from_bcd(M48_ADDR[SECOND] & 0x7f);
M48_ADDR[CONTROL] &= ~0x40; /* Clear READ bit */
SYS_TOD_PROTECT();
return 0;
}
int m48_tod_set(int year, /* 1980-2079 */
int month, /* 01-12 */
int day, /* 01-31 */
int hour, /* 00-23 */
int minute, /* 00-59 */
int second) /* 00-59 */
{
SYS_TOD_UNPROTECT();
M48_ADDR[CONTROL] |= 0x80; /* Set WRITE bit */
M48_ADDR[YEAR] = to_bcd(year % 100);
M48_ADDR[MONTH] = to_bcd(month);
M48_ADDR[DAY] = to_bcd(day);
M48_ADDR[DAY_OF_WEEK] = day_of_week(year, month, day) + 1;
M48_ADDR[HOUR] = to_bcd(hour);
M48_ADDR[MINUTE] = to_bcd(minute);
M48_ADDR[SECOND] = to_bcd(second);
M48_ADDR[CONTROL] &= ~0x80; /* Clear WRITE bit */
SYS_TOD_PROTECT();
return 0;
}
int m48_tod_init(void)
{
SYS_TOD_UNPROTECT();
M48_ADDR[CONTROL] = 0;
M48_ADDR[WATCH] = 0;
M48_ADDR[INTCTL] = 0;
/*
* If the oscillator is currently stopped (as on a new part shipped
* from the factory), start it running.
*
* Here is an example of the TOD bytes on a brand new M48T59Y part:
* 00 00 00 00 00 00 00 00 00 88 8c c3 bf c8 f5 01
*/
if (M48_ADDR[SECOND] & 0x80)
M48_ADDR[SECOND] = 0;
/* Is battery low */
if ( M48_ADDR[FLAGS] & 0x10) {
printf("NOTICE: Battery low on Real-Time Clock (replace SNAPHAT).\n");
}
SYS_TOD_PROTECT();
return 0;
}
/* Write to NVRAM */
void
nvram_write(long dest, const void *src, size_t count)
{
int i;
volatile unsigned char* d = (unsigned char*)dest;
volatile unsigned char* s = (unsigned char*)src;
SYS_TOD_UNPROTECT();
for( i = 0; i < count;i++)
d[i] = s[i];
SYS_TOD_PROTECT();
}
STATUS m48_tod_init(UINT8 *addr)
{
m48BaseAddr = addr;
SYS_TOD_UNPROTECT();
M48_ADDR[CONTROL] = 0;
M48_ADDR[WATCH] = 0;
M48_ADDR[INTCTL] = 0;
/*
* If the oscillator is currently stopped (as on a new part shipped
* from the factory), start it running.
*
* Here is an example of the TOD bytes on a brand new M48T59Y part:
* 00 00 00 00 00 00 00 00 00 88 8c c3 bf c8 f5 01
*/
if (M48_ADDR[SECOND] & 0x80)
M48_ADDR[SECOND] = 0;
SYS_TOD_PROTECT();
return OK;
}