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/*
* ds1302.c - Support for the Dallas Semiconductor DS1302 Timekeeping Chip
*
* Rex G. Feany <rfeany@zumanetworks.com>
*
*/
#include <common.h>
#include <command.h>
#include <rtc.h>
#if defined(CONFIG_CMD_DATE)
/* GPP Pins */
#define DATA 0x200
#define SCLK 0x400
#define RST 0x800
/* Happy Fun Defines(tm) */
#define RESET rtc_go_low(RST), rtc_go_low(SCLK)
#define N_RESET rtc_go_high(RST), rtc_go_low(SCLK)
#define CLOCK_HIGH rtc_go_high(SCLK)
#define CLOCK_LOW rtc_go_low(SCLK)
#define DATA_HIGH rtc_go_high(DATA)
#define DATA_LOW rtc_go_low(DATA)
#define DATA_READ (GTREGREAD(GPP_VALUE) & DATA)
#undef RTC_DEBUG
#ifdef RTC_DEBUG
# define DPRINTF(x,args...) printf("ds1302: " x , ##args)
static inline void DUMP(const char *ptr, int num)
{
while (num--) printf("%x ", *ptr++);
printf("]\n");
}
#else
# define DPRINTF(x,args...)
# define DUMP(ptr, num)
#endif
/* time data format for DS1302 */
struct ds1302_st
{
unsigned char CH:1; /* clock halt 1=stop 0=start */
unsigned char sec10:3;
unsigned char sec:4;
unsigned char zero0:1;
unsigned char min10:3;
unsigned char min:4;
unsigned char fmt:1; /* 1=12 hour 0=24 hour */
unsigned char zero1:1;
unsigned char hr10:2; /* 10 (0-2) or am/pm (am/pm, 0-1) */
unsigned char hr:4;
unsigned char zero2:2;
unsigned char date10:2;
unsigned char date:4;
unsigned char zero3:3;
unsigned char month10:1;
unsigned char month:4;
unsigned char zero4:5;
unsigned char day:3; /* day of week */
unsigned char year10:4;
unsigned char year:4;
unsigned char WP:1; /* write protect 1=protect 0=unprot */
unsigned char zero5:7;
};
static int ds1302_initted=0;
/* Pin control */
static inline void
rtc_go_high(unsigned int mask)
{
unsigned int f = GTREGREAD(GPP_VALUE) | mask;
GT_REG_WRITE(GPP_VALUE, f);
}
static inline void
rtc_go_low(unsigned int mask)
{
unsigned int f = GTREGREAD(GPP_VALUE) & ~mask;
GT_REG_WRITE(GPP_VALUE, f);
}
static inline void
rtc_go_input(unsigned int mask)
{
unsigned int f = GTREGREAD(GPP_IO_CONTROL) & ~mask;
GT_REG_WRITE(GPP_IO_CONTROL, f);
}
static inline void
rtc_go_output(unsigned int mask)
{
unsigned int f = GTREGREAD(GPP_IO_CONTROL) | mask;
GT_REG_WRITE(GPP_IO_CONTROL, f);
}
/* Access data in RTC */
static void
write_byte(unsigned char b)
{
int i;
unsigned char mask=1;
for(i=0;i<8;i++) {
CLOCK_LOW; /* Lower clock */
(b&mask)?DATA_HIGH:DATA_LOW; /* set data */
udelay(1);
CLOCK_HIGH; /* latch data with rising clock */
udelay(1);
mask=mask<<1;
}
}
static unsigned char
read_byte(void)
{
int i;
unsigned char mask=1;
unsigned char b=0;
for(i=0;i<8;i++) {
CLOCK_LOW;
udelay(1);
if (DATA_READ) b|=mask; /* if this bit is high, set in b */
CLOCK_HIGH; /* clock out next bit */
udelay(1);
mask=mask<<1;
}
return b;
}
static void
read_ser_drv(unsigned char addr, unsigned char *buf, int count)
{
int i;
#ifdef RTC_DEBUG
char *foo = buf;
#endif
DPRINTF("READ 0x%x bytes @ 0x%x [ ", count, addr);
addr|=1; /* READ */
N_RESET;
udelay(4);
write_byte(addr);
rtc_go_input(DATA); /* Put gpp pin into input mode */
udelay(1);
for(i=0;i<count;i++) *(buf++)=read_byte();
RESET;
rtc_go_output(DATA);/* Reset gpp for output */
udelay(4);
DUMP(foo, count);
}
static void
write_ser_drv(unsigned char addr, unsigned char *buf, int count)
{
int i;
DPRINTF("WRITE 0x%x bytes @ 0x%x [ ", count, addr);
DUMP(buf, count);
addr&=~1; /* WRITE */
N_RESET;
udelay(4);
write_byte(addr);
for(i=0;i<count;i++) write_byte(*(buf++));
RESET;
udelay(4);
}
void
rtc_init(void)
{
struct ds1302_st bbclk;
unsigned char b;
int mod;
DPRINTF("init\n");
rtc_go_output(DATA|SCLK|RST);
/* disable write protect */
b = 0;
write_ser_drv(0x8e,&b,1);
/* enable trickle */
b = 0xa5; /* 1010.0101 */
write_ser_drv(0x90,&b,1);
/* read burst */
read_ser_drv(0xbe, (unsigned char *)&bbclk, 8);
/* Sanity checks */
mod = 0;
if (bbclk.CH) {
printf("ds1302: Clock was halted, starting clock\n");
bbclk.CH=0;
mod=1;
}
if (bbclk.fmt) {
printf("ds1302: Clock was in 12 hour mode, fixing\n");
bbclk.fmt=0;
mod=1;
}
if (bbclk.year>9) {
printf("ds1302: Year was corrupted, fixing\n");
bbclk.year10=100/10; /* 2000 - why not? ;) */
bbclk.year=0;
mod=1;
}
/* Write out the changes if needed */
if (mod) {
/* enable write protect */
bbclk.WP = 1;
write_ser_drv(0xbe,(unsigned char *)&bbclk,8);
} else {
/* Else just turn write protect on */
b = 0x80;
write_ser_drv(0x8e,&b,1);
}
DPRINTF("init done\n");
ds1302_initted=1;
}
void
rtc_reset(void)
{
if(!ds1302_initted) rtc_init();
/* TODO */
}
int
rtc_get(struct rtc_time *tmp)
{
int rel = 0;
struct ds1302_st bbclk;
if(!ds1302_initted) rtc_init();
read_ser_drv(0xbe,(unsigned char *)&bbclk, 8); /* read burst */
if (bbclk.CH) {
printf("ds1302: rtc_get: Clock was halted, clock probably "
"corrupt\n");
rel = -1;
}
tmp->tm_sec=10*bbclk.sec10+bbclk.sec;
tmp->tm_min=10*bbclk.min10+bbclk.min;
tmp->tm_hour=10*bbclk.hr10+bbclk.hr;
tmp->tm_wday=bbclk.day;
tmp->tm_mday=10*bbclk.date10+bbclk.date;
tmp->tm_mon=10*bbclk.month10+bbclk.month;
tmp->tm_year=10*bbclk.year10+bbclk.year + 1900;
tmp->tm_yday = 0;
tmp->tm_isdst= 0;
DPRINTF("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
tmp->tm_hour, tmp->tm_min, tmp->tm_sec );
return rel;
}
int rtc_set(struct rtc_time *tmp)
{
struct ds1302_st bbclk;
unsigned char b=0;
if(!ds1302_initted) rtc_init();
DPRINTF("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
memset(&bbclk,0,sizeof(bbclk));
bbclk.CH=0; /* dont halt */
bbclk.WP=1; /* write protect when we're done */
bbclk.sec10=tmp->tm_sec/10;
bbclk.sec=tmp->tm_sec%10;
bbclk.min10=tmp->tm_min/10;
bbclk.min=tmp->tm_min%10;
bbclk.hr10=tmp->tm_hour/10;
bbclk.hr=tmp->tm_hour%10;
bbclk.day=tmp->tm_wday;
bbclk.date10=tmp->tm_mday/10;
bbclk.date=tmp->tm_mday%10;
bbclk.month10=tmp->tm_mon/10;
bbclk.month=tmp->tm_mon%10;
tmp->tm_year -= 1900;
bbclk.year10=tmp->tm_year/10;
bbclk.year=tmp->tm_year%10;
write_ser_drv(0x8e,&b,1); /* disable write protect */
write_ser_drv(0xbe,(unsigned char *)&bbclk, 8); /* write burst */
return 0;
}
#endif
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