--- /dev/null
+/*
+ * 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
Code Review / kvmfornfv.git / blobdiff