@@ -56,6 +56,42 @@ struct rk808_rtc {

int irq;

};

+/*

+ * The Rockchip calendar used by the RK808 counts November with 31 days. We use

+ * these translation functions to convert its dates to/from the Gregorian

+ * calendar used by the rest of the world. We arbitrarily define Jan 1st, 2016

+ * as the day when both calendars were in sync, and treat all other dates

+ * relative to that.

+ * NOTE: Other system software (e.g. firmware) that reads the same hardware must

+ * implement this exact same conversion algorithm, with the same anchor date.

+ */

+static time64_t nov2dec_transitions(struct rtc_time *tm)

+{

+ return (tm->tm_year + 1900) - 2016 + (tm->tm_mon + 1 > 11 ? 1 : 0);

+}

+

+static void rockchip_to_gregorian(struct rtc_time *tm)

+{

+ /* If it's Nov 31st, rtc_tm_to_time64() will count that like Dec 1st */

+ time64_t time = rtc_tm_to_time64(tm);

+ rtc_time64_to_tm(time + nov2dec_transitions(tm) * 86400, tm);

+}

+

+static void gregorian_to_rockchip(struct rtc_time *tm)

+{

+ time64_t extra_days = nov2dec_transitions(tm);

+ time64_t time = rtc_tm_to_time64(tm);

+ rtc_time64_to_tm(time - extra_days * 86400, tm);

+

+ /* Compensate if we went back over Nov 31st (will work up to 2381) */

+ if (nov2dec_transitions(tm) < extra_days) {

+ if (tm->tm_mon + 1 == 11)

+ tm->tm_mday++; /* This may result in 31! */

+ else

+ rtc_time64_to_tm(time - (extra_days - 1) * 86400, tm);

+ }

+}

+

/* Read current time and date in RTC */

static int rk808_rtc_readtime(struct device *dev, struct rtc_time *tm)

{

@@ -101,9 +137,10 @@ static int rk808_rtc_readtime(struct device *dev, struct rtc_time *tm)

tm->tm_mon = (bcd2bin(rtc_data[4] & MONTHS_REG_MSK)) - 1;

tm->tm_year = (bcd2bin(rtc_data[5] & YEARS_REG_MSK)) + 100;

tm->tm_wday = bcd2bin(rtc_data[6] & WEEKS_REG_MSK);

+ rockchip_to_gregorian(tm);

dev_dbg(dev, "RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d

",

1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,

- tm->tm_wday, tm->tm_hour , tm->tm_min, tm->tm_sec);

+ tm->tm_wday, tm->tm_hour, tm->tm_min, tm->tm_sec);

return ret;

}

@@ -116,6 +153,10 @@ static int rk808_rtc_set_time(struct device *dev, struct rtc_time *tm)

u8 rtc_data[NUM_TIME_REGS];

int ret;

+ dev_dbg(dev, "set RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d

",

+ 1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,

+ tm->tm_wday, tm->tm_hour, tm->tm_min, tm->tm_sec);

+ gregorian_to_rockchip(tm);

rtc_data[0] = bin2bcd(tm->tm_sec);

rtc_data[1] = bin2bcd(tm->tm_min);

rtc_data[2] = bin2bcd(tm->tm_hour);

@@ -123,9 +164,6 @@ static int rk808_rtc_set_time(struct device *dev, struct rtc_time *tm)

rtc_data[4] = bin2bcd(tm->tm_mon + 1);

rtc_data[5] = bin2bcd(tm->tm_year - 100);

rtc_data[6] = bin2bcd(tm->tm_wday);

- dev_dbg(dev, "set RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d

",

- 1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,

- tm->tm_wday, tm->tm_hour , tm->tm_min, tm->tm_sec);

/* Stop RTC while updating the RTC registers */

ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,

@@ -170,6 +208,7 @@ static int rk808_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)

alrm->time.tm_mday = bcd2bin(alrm_data[3] & DAYS_REG_MSK);

alrm->time.tm_mon = (bcd2bin(alrm_data[4] & MONTHS_REG_MSK)) - 1;

alrm->time.tm_year = (bcd2bin(alrm_data[5] & YEARS_REG_MSK)) + 100;

+ rockchip_to_gregorian(&alrm->time);

ret = regmap_read(rk808->regmap, RK808_RTC_INT_REG, &int_reg);

if (ret) {

@@ -227,6 +266,7 @@ static int rk808_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)

alrm->time.tm_mday, alrm->time.tm_wday, alrm->time.tm_hour,

alrm->time.tm_min, alrm->time.tm_sec);

+ gregorian_to_rockchip(&alrm->time);

alrm_data[0] = bin2bcd(alrm->time.tm_sec);

alrm_data[1] = bin2bcd(alrm->time.tm_min);

alrm_data[2] = bin2bcd(alrm->time.tm_hour);