RTC: Handle turn of the year correctly, detect uninitialized RTC (loss of VBAT)

[z180-stamp.git] / avr / pcf8583.c

diff --git a/avr/pcf8583.c b/avr/pcf8583.c
index 169e4e937baa4ad7aee475316c6332c0ae86cb94..bdb779f0c4f1bd5137c3f4f854fa262a0c077a48 100644 (file)
--- a/avr/pcf8583.c
+++ b/avr/pcf8583.c
@@ -48,14 +48,13 @@ static uint8_t bin2bcd (uint_fast8_t val)
 
 int rtc_get (struct tm *tmp)
 {
-       int rel = 0;
        uint8_t rtcbuf[NR_OF_REGS];
        int16_t year;
 
        i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, rtcbuf, NR_OF_REGS);
        i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0x10, 1, (uint8_t *) &year, 2);
 
-       debug_rtc("Get RTC year: %u, year/date: %02x, wdays/month: %02x, "
+       debug_rtc("Get RTC year: %u, wdays/month: %02x, year/date: %02x, "
                "hour: %02x, min: %02x, sec: %02x, (stat: %02x)\n", year,
                rtcbuf[6], rtcbuf[5], rtcbuf[4], rtcbuf[3], rtcbuf[2], rtcbuf[0]);
 
@@ -64,26 +63,26 @@ int rtc_get (struct tm *tmp)
        tmp->tm_hour = bcd2bin (rtcbuf[REG_HOUR]   & 0x3F);
        tmp->tm_mday = bcd2bin (rtcbuf[REG_YRDATE] & 0x3F);
        tmp->tm_mon  = bcd2bin (rtcbuf[REG_WDMON]  & 0x1F) - 1;
-       while (year%4 < (rtcbuf[REG_YRDATE]>>6)) {
+       while (year%4 != (rtcbuf[REG_YRDATE]>>6)) {
                year++;
-               /* TODO: update RTC ram */
+               i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0x10, 1, (uint8_t *) &year, 2);
        }
-       tmp->tm_year  = year;
+       tmp->tm_year  = year - 1900;
        tmp->tm_wday = rtcbuf[REG_WDMON] >> 5;
        tmp->tm_yday = 0;
        tmp->tm_isdst= 0;
 
-
        debug_rtc( "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;
+       return rtcbuf[REG_CS] == 0x04 ? 0 : 1;
 }
 
 int rtc_set (struct tm *tmp)
 {
        uint8_t rtcbuf[NR_OF_REGS];
+       int16_t year = tmp->tm_year + 1900;
 
        debug_rtc("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
@@ -92,16 +91,15 @@ int rtc_set (struct tm *tmp)
        rtcbuf[REG_CS] = 0x84;
        rtcbuf[REG_CSEC] = 0x00;
        rtcbuf[REG_WDMON ] = (bin2bcd(tmp->tm_mon) + 1) | ((tmp->tm_wday) << 5);
-       rtcbuf[REG_YRDATE] = ((tmp->tm_year % 4) << 6) | bin2bcd(tmp->tm_mday);
+       rtcbuf[REG_YRDATE] = ((year % 4) << 6) | bin2bcd(tmp->tm_mday);
        rtcbuf[REG_HOUR  ] = bin2bcd(tmp->tm_hour);
        rtcbuf[REG_MIN   ] = bin2bcd(tmp->tm_min);
        rtcbuf[REG_SEC   ] = bin2bcd(tmp->tm_sec);
 
        i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0,    1, rtcbuf, NR_OF_REGS);
-       i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0x10, 1, (uint8_t *) &tmp->tm_year, 2);
+       i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0x10, 1, (uint8_t *) &year, 2);
        rtcbuf[REG_CS] = 0x04;
        i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, rtcbuf, 1);
 
-
        return 0;
 }