328 lines
6.2 KiB
C
328 lines
6.2 KiB
C
/*
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* ds1302.c - Support for the Dallas Semiconductor DS1302 Timekeeping Chip
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*
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* Rex G. Feany <rfeany@zumanetworks.com>
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*
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*/
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#include <common.h>
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#include <command.h>
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#include <rtc.h>
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#if defined(CONFIG_RTC_DS1302) && (CONFIG_COMMANDS & CFG_CMD_DATE)
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/* GPP Pins */
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#define DATA 0x200
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#define SCLK 0x400
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#define RST 0x800
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/* Happy Fun Defines(tm) */
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#define RESET rtc_go_low(RST), rtc_go_low(SCLK)
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#define N_RESET rtc_go_high(RST), rtc_go_low(SCLK)
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#define CLOCK_HIGH rtc_go_high(SCLK)
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#define CLOCK_LOW rtc_go_low(SCLK)
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#define DATA_HIGH rtc_go_high(DATA)
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#define DATA_LOW rtc_go_low(DATA)
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#define DATA_READ (GTREGREAD(GPP_VALUE) & DATA)
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#undef RTC_DEBUG
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#ifdef RTC_DEBUG
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# define DPRINTF(x,args...) printf("ds1302: " x , ##args)
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static inline void DUMP(const char *ptr, int num)
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{
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while (num--) printf("%x ", *ptr++);
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printf("]\n");
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}
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#else
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# define DPRINTF(x,args...)
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# define DUMP(ptr, num)
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#endif
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/* time data format for DS1302 */
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struct ds1302_st
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{
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unsigned char CH:1; /* clock halt 1=stop 0=start */
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unsigned char sec10:3;
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unsigned char sec:4;
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unsigned char zero0:1;
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unsigned char min10:3;
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unsigned char min:4;
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unsigned char fmt:1; /* 1=12 hour 0=24 hour */
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unsigned char zero1:1;
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unsigned char hr10:2; /* 10 (0-2) or am/pm (am/pm, 0-1) */
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unsigned char hr:4;
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unsigned char zero2:2;
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unsigned char date10:2;
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unsigned char date:4;
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unsigned char zero3:3;
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unsigned char month10:1;
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unsigned char month:4;
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unsigned char zero4:5;
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unsigned char day:3; /* day of week */
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unsigned char year10:4;
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unsigned char year:4;
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unsigned char WP:1; /* write protect 1=protect 0=unprot */
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unsigned char zero5:7;
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};
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static int ds1302_initted=0;
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/* Pin control */
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static inline void
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rtc_go_high(unsigned int mask)
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{
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unsigned int f = GTREGREAD(GPP_VALUE) | mask;
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GT_REG_WRITE(GPP_VALUE, f);
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}
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static inline void
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rtc_go_low(unsigned int mask)
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{
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unsigned int f = GTREGREAD(GPP_VALUE) & ~mask;
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GT_REG_WRITE(GPP_VALUE, f);
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}
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static inline void
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rtc_go_input(unsigned int mask)
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{
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unsigned int f = GTREGREAD(GPP_IO_CONTROL) & ~mask;
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GT_REG_WRITE(GPP_IO_CONTROL, f);
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}
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static inline void
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rtc_go_output(unsigned int mask)
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{
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unsigned int f = GTREGREAD(GPP_IO_CONTROL) | mask;
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GT_REG_WRITE(GPP_IO_CONTROL, f);
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}
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/* Access data in RTC */
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static void
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write_byte(unsigned char b)
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{
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int i;
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unsigned char mask=1;
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for(i=0;i<8;i++) {
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CLOCK_LOW; /* Lower clock */
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(b&mask)?DATA_HIGH:DATA_LOW; /* set data */
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udelay(1);
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CLOCK_HIGH; /* latch data with rising clock */
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udelay(1);
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mask=mask<<1;
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}
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}
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static unsigned char
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read_byte(void)
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{
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int i;
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unsigned char mask=1;
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unsigned char b=0;
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for(i=0;i<8;i++) {
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CLOCK_LOW;
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udelay(1);
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if (DATA_READ) b|=mask; /* if this bit is high, set in b */
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CLOCK_HIGH; /* clock out next bit */
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udelay(1);
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mask=mask<<1;
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}
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return b;
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}
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static void
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read_ser_drv(unsigned char addr, unsigned char *buf, int count)
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{
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int i;
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#ifdef RTC_DEBUG
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char *foo = buf;
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#endif
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DPRINTF("READ 0x%x bytes @ 0x%x [ ", count, addr);
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addr|=1; /* READ */
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N_RESET;
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udelay(4);
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write_byte(addr);
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rtc_go_input(DATA); /* Put gpp pin into input mode */
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udelay(1);
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for(i=0;i<count;i++) *(buf++)=read_byte();
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RESET;
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rtc_go_output(DATA);/* Reset gpp for output */
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udelay(4);
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DUMP(foo, count);
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}
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static void
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write_ser_drv(unsigned char addr, unsigned char *buf, int count)
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{
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int i;
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DPRINTF("WRITE 0x%x bytes @ 0x%x [ ", count, addr);
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DUMP(buf, count);
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addr&=~1; /* WRITE */
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N_RESET;
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udelay(4);
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write_byte(addr);
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for(i=0;i<count;i++) write_byte(*(buf++));
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RESET;
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udelay(4);
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}
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void
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rtc_init(void)
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{
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struct ds1302_st bbclk;
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unsigned char b;
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int mod;
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DPRINTF("init\n");
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rtc_go_output(DATA|SCLK|RST);
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/* disable write protect */
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b = 0;
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write_ser_drv(0x8e,&b,1);
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/* enable trickle */
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b = 0xa5; /* 1010.0101 */
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write_ser_drv(0x90,&b,1);
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/* read burst */
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read_ser_drv(0xbe, (unsigned char *)&bbclk, 8);
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/* Sanity checks */
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mod = 0;
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if (bbclk.CH) {
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printf("ds1302: Clock was halted, starting clock\n");
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bbclk.CH=0;
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mod=1;
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}
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if (bbclk.fmt) {
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printf("ds1302: Clock was in 12 hour mode, fixing\n");
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bbclk.fmt=0;
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mod=1;
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}
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if (bbclk.year>9) {
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printf("ds1302: Year was corrupted, fixing\n");
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bbclk.year10=100/10; /* 2000 - why not? ;) */
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bbclk.year=0;
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mod=1;
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}
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/* Write out the changes if needed */
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if (mod) {
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/* enable write protect */
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bbclk.WP = 1;
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write_ser_drv(0xbe,(unsigned char *)&bbclk,8);
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} else {
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/* Else just turn write protect on */
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b = 0x80;
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write_ser_drv(0x8e,&b,1);
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}
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DPRINTF("init done\n");
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ds1302_initted=1;
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}
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void
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rtc_reset(void)
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{
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if(!ds1302_initted) rtc_init();
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/* TODO */
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}
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void
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rtc_get(struct rtc_time *tmp)
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{
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struct ds1302_st bbclk;
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if(!ds1302_initted) rtc_init();
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read_ser_drv(0xbe,(unsigned char *)&bbclk, 8); /* read burst */
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if (bbclk.CH) {
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printf("ds1302: rtc_get: Clock was halted, clock probably "
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"corrupt\n");
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}
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tmp->tm_sec=10*bbclk.sec10+bbclk.sec;
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tmp->tm_min=10*bbclk.min10+bbclk.min;
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tmp->tm_hour=10*bbclk.hr10+bbclk.hr;
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tmp->tm_wday=bbclk.day;
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tmp->tm_mday=10*bbclk.date10+bbclk.date;
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tmp->tm_mon=10*bbclk.month10+bbclk.month;
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tmp->tm_year=10*bbclk.year10+bbclk.year + 1900;
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tmp->tm_yday = 0;
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tmp->tm_isdst= 0;
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DPRINTF("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
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tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
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tmp->tm_hour, tmp->tm_min, tmp->tm_sec );
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}
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void
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rtc_set(struct rtc_time *tmp)
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{
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struct ds1302_st bbclk;
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unsigned char b=0;
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if(!ds1302_initted) rtc_init();
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DPRINTF("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
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tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
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tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
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memset(&bbclk,0,sizeof(bbclk));
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bbclk.CH=0; /* dont halt */
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bbclk.WP=1; /* write protect when we're done */
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bbclk.sec10=tmp->tm_sec/10;
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bbclk.sec=tmp->tm_sec%10;
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bbclk.min10=tmp->tm_min/10;
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bbclk.min=tmp->tm_min%10;
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bbclk.hr10=tmp->tm_hour/10;
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bbclk.hr=tmp->tm_hour%10;
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bbclk.day=tmp->tm_wday;
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bbclk.date10=tmp->tm_mday/10;
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bbclk.date=tmp->tm_mday%10;
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bbclk.month10=tmp->tm_mon/10;
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bbclk.month=tmp->tm_mon%10;
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tmp->tm_year -= 1900;
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bbclk.year10=tmp->tm_year/10;
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bbclk.year=tmp->tm_year%10;
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write_ser_drv(0x8e,&b,1); /* disable write protect */
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write_ser_drv(0xbe,(unsigned char *)&bbclk, 8); /* write burst */
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}
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#endif
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