diff options
| -rw-r--r-- | firmware/drivers/rtc/rtc_mc13783.c | 230 |
1 files changed, 121 insertions, 109 deletions
diff --git a/firmware/drivers/rtc/rtc_mc13783.c b/firmware/drivers/rtc/rtc_mc13783.c index d98ae9b..a1f78f7 100644 --- a/firmware/drivers/rtc/rtc_mc13783.c +++ b/firmware/drivers/rtc/rtc_mc13783.c @@ -26,62 +26,74 @@ /* NOTE: Defined the base to be original firmware compatible if needed - * ie. the day and year as it would interpret a DAY register value of zero. */ -/* Days passed since midnight 01 Jan, 1601 to midnight on the base date. */ +/* None of this code concerns itself with (year mod 100) = 0 leap year + * exceptions because all (year mod 4) = 0 years in the relevant range are + * leap years. A base year of 1901 to an end date of 28 Feb 2100 are ok. */ + #ifdef TOSHIBA_GIGABEAT_S /* Gigabeat S seems to be 1 day behind the ususual - this will * make the RTC match file dates created by retailos. */ - #define RTC_BASE_DAY_COUNT 138425 - #define RTC_BASE_MONTH 12 - #define RTC_BASE_DAY 31 + #define RTC_BASE_WDAY 1 /* Monday */ + #define RTC_BASE_YDAY 364 /* 31 Dec */ #define RTC_BASE_YEAR 1979 #elif 1 - #define RTC_BASE_DAY_COUNT 138426 - #define RTC_BASE_MONTH 1 - #define RTC_BASE_DAY 1 + #define RTC_BASE_WDAY 2 /* Tuesday */ + #define RTC_BASE_YDAY 0 /* 01 Jan */ #define RTC_BASE_YEAR 1980 #else - #define RTC_BASE_DAY_COUNT 134774 - #define RTC_BASE_MONTH 1 - #define RTC_BASE_DAY 1 + #define RTC_BASE_WDAY 4 /* Thursday */ + #define RTC_BASE_YDAY 0 /* 01 Jan */ #define RTC_BASE_YEAR 1970 #endif +/* Reference year for leap calculation - year that is on or before the base + * year and immediately follows a leap year */ +#define RTC_REF_YEAR_OFFS ((RTC_BASE_YEAR - 1) & 3) +#define RTC_REF_YEAR (RTC_BASE_YEAR - RTC_REF_YEAR_OFFS) + enum rtc_registers_indexes { RTC_REG_TIME = 0, RTC_REG_DAY, RTC_REG_TIME2, - RTC_NUM_REGS, + RTC_NUM_REGS_RD = 3, + RTC_NUM_REGS_WR = 2, }; -/* was it an alarm that triggered power on ? */ -static bool alarm_start = false; - -static const unsigned char rtc_registers[RTC_NUM_REGS] = +static const unsigned char rtc_registers[RTC_NUM_REGS_RD] = { [RTC_REG_TIME] = MC13783_RTC_TIME, [RTC_REG_DAY] = MC13783_RTC_DAY, [RTC_REG_TIME2] = MC13783_RTC_TIME, }; -static const unsigned char month_table[2][12] = +/* was it an alarm that triggered power on ? */ +static bool alarm_start = false; + +static const unsigned short month_table[13] = { - { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, - { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, + /* Since 1 Jan, how many days have passed this year? (non-leap) + +31 28 31 30 31 30 31 31 30 31 30 31 */ + 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 }; -/* Get number of leaps since the reference date of 1601/01/01 */ -static int get_leap_count(int d) +static bool read_time_and_day(uint32_t regs[RTC_NUM_REGS_RD]) { - int lm = (d + 1) / 146097; - int lc = (d + 1 - lm) / 36524; - int ly = (d + 1 - lm + lc) / 1461; - return ly - lc + lm; -} + /* Read time, day, time - 2nd read of time should be the same or + * greater */ + do + { + if (mc13783_read_regs(rtc_registers, regs, + RTC_NUM_REGS_RD) < RTC_NUM_REGS_RD) + { + /* Couldn't read registers */ + return false; + } + } + /* If TOD counter turned over - reread */ + while (regs[RTC_REG_TIME2] < regs[RTC_REG_TIME]); -static int is_leap_year(int y) -{ - return (y % 4) == 0 && ((y % 100) != 0 || (y % 400) == 0) ? 1 : 0; + return true; } /** Public APIs **/ @@ -97,114 +109,110 @@ void rtc_init(void) int rtc_read_datetime(struct tm *tm) { - uint32_t regs[RTC_NUM_REGS]; - int year, leap, month, day, hour, min; + uint32_t regs[RTC_NUM_REGS_RD]; + int year, month, yday, x, n; - /* Read time, day, time - 2nd read of time should be the same or - * greater */ - do - { - if (mc13783_read_regs(rtc_registers, regs, - RTC_NUM_REGS) < RTC_NUM_REGS) - { - /* Couldn't read registers */ - return 0; - } - } - /* If TOD counter turned over - reread */ - while (regs[RTC_REG_TIME2] < regs[RTC_REG_TIME]); + if (!read_time_and_day(regs)) + return 0; + + /* TOD: 0 to 86399 */ + x = regs[RTC_REG_TIME]; - /* TOD: = 0 to 86399 */ - hour = regs[RTC_REG_TIME] / 3600; - regs[RTC_REG_TIME] -= hour*3600; - tm->tm_hour = hour; + /* Hour */ + n = x / 3600; + tm->tm_hour = n; - min = regs[RTC_REG_TIME] / 60; - regs[RTC_REG_TIME] -= min*60; - tm->tm_min = min; + /* Minute */ + x -= n*3600; + n = x / 60; + tm->tm_min = n; - tm->tm_sec = regs[RTC_REG_TIME]; + /* Second */ + x -= n*60; + tm->tm_sec = x; /* DAY: 0 to 32767 */ - day = regs[RTC_REG_DAY] + RTC_BASE_DAY_COUNT; + x = regs[RTC_REG_DAY]; /* Weekday */ - tm->tm_wday = (day + 1) % 7; /* 1601/01/01 = Monday */ + tm->tm_wday = (x + RTC_BASE_WDAY) % 7; - /* Get number of leaps for today */ - leap = get_leap_count(day); - year = (day - leap) / 365; + /* Year */ + x += RTC_REF_YEAR_OFFS*365 + RTC_BASE_YDAY; - /* Get number of leaps for yesterday */ - leap = get_leap_count(day - 1); + /* Lag year increment by subtracting leaps since the reference year + * on 31 Dec of each leap year, essentially removing them from the + * calculation */ + n = (x + 1) / 1461; + year = (x - n) / 365; - /* Get day number for year 0-364|365 */ - day = day - leap - year * 365; + /* Year day */ + yday = x - n - year*365; - year += 1601; + /* If (x + 1) mod 1461 == 0, then it is yday 365 of a leap year */ + if (n * 1461 - 1 == x) + yday++; - /* Get the current month */ - leap = is_leap_year(year); + tm->tm_yday = x = yday; - for (month = 0; month < 12; month++) + if (((year + RTC_REF_YEAR) & 3) == 0 && x >= month_table[2]) { - int days = month_table[leap][month]; - - if (day < days) - break; + if (x > month_table[2]) + yday--; /* 1 Mar or after; lag date by one day */ - day -= days; + x--; /* 29 Feb or after, lag month by one day */ } - tm->tm_mday = day + 1; /* 1 to 31 */ + /* Get the current month */ + month = x >> 5; /* yday / 32, close enough */ + + if (month_table[month + 1] <= x) + month++; /* Round to next */ + + tm->tm_mday = yday - month_table[month] + 1; /* 1 to 31 */ tm->tm_mon = month; /* 0 to 11 */ - tm->tm_year = year % 100 + 100; + + /* {BY to (BY+89 or 90)} - 1900 */ + tm->tm_year = year + RTC_REF_YEAR - 1900; return 7; } int rtc_write_datetime(const struct tm *tm) { - uint32_t regs[2]; - int year, leap, month, day, i, base_yearday; + uint32_t regs[RTC_NUM_REGS_WR]; + int year, month, x; - regs[RTC_REG_TIME] = tm->tm_sec + - tm->tm_min*60 + - tm->tm_hour*3600; - - year = tm->tm_year - 100; - - if (year < RTC_BASE_YEAR - 1900) - year += 2000; - else - year += 1900; + /* Convert time of day into seconds since midnight */ + x = tm->tm_sec + tm->tm_min*60 + tm->tm_hour*3600; - /* Get number of leaps for day before base */ - leap = get_leap_count(RTC_BASE_DAY_COUNT - 1); + /* Keep in range (it throws off the PMIC counters otherwise) */ + regs[RTC_REG_TIME] = MAX(0, MIN(86399, x)); - /* Get day number for base year 0-364|365 */ - base_yearday = RTC_BASE_DAY_COUNT - leap - - (RTC_BASE_YEAR - 1601) * 365; + year = tm->tm_year + 1900; - /* Get the number of days elapsed from reference */ - for (i = RTC_BASE_YEAR, day = 0; i < year; i++) - { - day += is_leap_year(i) ? 366 : 365; - } + /* Get the number of days elapsed from 1 Jan of reference year to 1 Jan of + * this year */ + x = year - RTC_REF_YEAR; + x = x*365 + (x >> 2); - /* Find the number of days passed this year up to the 1st of the - * month. */ - leap = is_leap_year(year); + /* Add the number of days passed this year since 1 Jan and offset by the + * base yearday and the reference offset in days from the base */ month = tm->tm_mon; + x += month_table[month] + tm->tm_mday - RTC_REF_YEAR_OFFS*365 + - RTC_BASE_YDAY; - for (i = 0; i < month; i++) - { - day += month_table[leap][i]; + if ((year & 3) != 0 || month < 2) { + /* Sub one day because tm_mday starts at 1, otherwise the offset is + * required because of 29 Feb */ + x--; } - regs[RTC_REG_DAY] = day + tm->tm_mday - 1 - base_yearday; + /* Keep in range */ + regs[RTC_REG_DAY] = MAX(0, MIN(32767, x)); - if (mc13783_write_regs(rtc_registers, regs, 2) == 2) + if (mc13783_write_regs(rtc_registers, regs, RTC_NUM_REGS_WR) + == RTC_NUM_REGS_WR) { return 7; } @@ -238,20 +246,24 @@ bool rtc_check_alarm_started(bool release_alarm) void rtc_set_alarm(int h, int m) { - int day = mc13783_read(MC13783_RTC_DAY); - int tod = mc13783_read(MC13783_RTC_TIME); + uint32_t regs[RTC_NUM_REGS_RD]; + uint32_t tod; - if (h*3600 + m*60 < tod) - day++; + if (!read_time_and_day(regs)) + return; - mc13783_write(MC13783_RTC_DAY_ALARM, day); - mc13783_write(MC13783_RTC_ALARM, h*3600 + m*60); + tod = h*3600 + m*60; + + if (tod < regs[RTC_REG_TIME]) + regs[RTC_REG_DAY]++; + + mc13783_write(MC13783_RTC_DAY_ALARM, regs[RTC_REG_DAY]); + mc13783_write(MC13783_RTC_ALARM, tod); } void rtc_get_alarm(int *h, int *m) { - int tod = mc13783_read(MC13783_RTC_ALARM); + uint32_t tod = mc13783_read(MC13783_RTC_ALARM); *h = tod / 3600; *m = tod % 3600 / 60; } - |