/* * 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_RTC_DS1302) && (CONFIG_COMMANDS & CFG_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; /* 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 */ } void rtc_get(struct rtc_time *tmp) { 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"); } 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 ); } void 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 */ } #endif