FoenixMCP/src/dev/rtc.c

/*
 * Definitions for access the bq4802LY real time clock
 */

#include "log.h"
#include "interrupt.h"
#include "rtc.h"
#include "rtc_reg.h"
#include "simpleio.h"

static long rtc_ticks;

/*
 * Interrupt handler for the real time clock
 */
void rtc_handle_int() {
    unsigned char flags;

    flags = *RTC_FLAGS;
    if (flags | RTC_PF) {
        /* Peridic interrupt: increment the ticks counter */
        rtc_ticks++;
    }
}

/*
 * Initialize the RTC
 */
void rtc_init() {
    unsigned char rates;
    unsigned char enables;

    // int_disable(INT_RTC);
    //
    // /* Reset the ticks counter */
    // rtc_ticks = 0;
    //
    // /* Set the periodic interrupt to 976.5625 microseconds */
    // *RTC_RATES = (*RTC_RATES & RTC_RATES_WD) | RTC_RATE_976us;
    //
    // /* Enable the periodic interrupt */
    *RTC_RATES = 0;
    *RTC_ENABLES = 0; // RTC_PIE;

    /* Make sure the RTC is on */
    *RTC_CTRL = RTC_STOP;

    /* Register our interrupt handler and clear out any pending interrupts */
    // int_register(INT_RTC, rtc_handle_int);
    // int_clear(INT_RTC);
    // int_enable(INT_RTC);
}

/*
 * Set the time on the RTC
 *
 * Inputs:
 * time = pointer to a t_time record containing the correct time
 */
void rtc_set_time(p_time time) {
    unsigned char ctrl;
    unsigned char century_bcd, year_bcd, month_bcd, day_bcd;
    unsigned char hour_bcd, minute_bcd, second_bcd;
    unsigned short century;
    unsigned short year;

    century = time->year / 100;
    year = time->year - (century * 100);

    /* Compute the BCD values for the time */

    century_bcd = i_to_bcd(century);
    year_bcd = i_to_bcd(year);
    month_bcd = i_to_bcd(time->month);
    day_bcd = i_to_bcd(time->day);
    hour_bcd = i_to_bcd(time->hour);
    minute_bcd = i_to_bcd(time->minute);
    second_bcd = i_to_bcd(time->second);

    log_num(LOG_INFO, "Century: ", century_bcd);
    log_num(LOG_INFO, "Year: ", year_bcd);
    log_num(LOG_INFO, "Month: ", month_bcd);
    log_num(LOG_INFO, "Day: ", day_bcd);
    log_num(LOG_INFO, "Hour: ", hour_bcd);
    log_num(LOG_INFO, "Minute: ", minute_bcd);
    log_num(LOG_INFO, "Second: ", second_bcd);

    if (time->is_24hours) {
        if (time->is_pm) {
            hour_bcd = hour_bcd | 0x80;
        }
    }
    minute_bcd = i_to_bcd(time->minute);
    second_bcd = i_to_bcd(time->second);

    /* Temporarily disable updates to the clock */
    ctrl = *RTC_CTRL;
    *RTC_CTRL = ctrl | RTC_UTI;
    log(LOG_INFO, "RTC Disabled");
    log_num(LOG_INFO, "RTC Rates: ", *RTC_RATES);
    log_num(LOG_INFO, "RTC Enables: ", *RTC_ENABLES);
    log_num(LOG_INFO, "RTC Flags: ", *RTC_FLAGS);
    log_num(LOG_INFO, "RTC Control: ", *RTC_CTRL);

    /* Set the time in the RTC */

    *RTC_CENTURY = century_bcd;
    *RTC_YEAR = year_bcd;
    *RTC_MONTH = month_bcd;
    *RTC_DAY = day_bcd;
    *RTC_HOUR = hour_bcd;
    *RTC_MIN = minute_bcd;
    *RTC_SEC = second_bcd;

    /* Verify */

    century_bcd = *RTC_CENTURY;
    year_bcd = *RTC_YEAR;
    month_bcd = *RTC_MONTH;
    day_bcd = *RTC_DAY;
    hour_bcd = *RTC_HOUR;
    minute_bcd = *RTC_MIN;
    second_bcd = *RTC_SEC;
    log_num(LOG_INFO, "REG Century: ", century_bcd);
    log_num(LOG_INFO, "REG Year: ", year_bcd);
    log_num(LOG_INFO, "REG Month: ", month_bcd);
    log_num(LOG_INFO, "REG Day: ", day_bcd);
    log_num(LOG_INFO, "REG Hour: ", hour_bcd);
    log_num(LOG_INFO, "REG Minute: ", minute_bcd);
    log_num(LOG_INFO, "REG Second: ", second_bcd);

    /* Set the 24/12 hour control bit if needed */
    if (time->is_24hours) {
        ctrl = ctrl | RTC_2412;
    }

    /* Re-enable updates to the clock */
    *RTC_CTRL = (ctrl & 0x7f) | RTC_STOP;
    log(LOG_INFO, "RTC Enabled");
    log_num(LOG_INFO, "RTC Rates: ", *RTC_RATES);
    log_num(LOG_INFO, "RTC Enables: ", *RTC_ENABLES);
    log_num(LOG_INFO, "RTC Flags: ", *RTC_FLAGS);
    log_num(LOG_INFO, "RTC Control: ", *RTC_CTRL);
}

/*
 * Get the time on the RTC
 *
 * Inputs:
 * time = pointer to a t_time record in which to put the current time
 */
void rtc_get_time(p_time time) {
    unsigned char ctrl;
    unsigned char century_bcd, year_bcd, month_bcd, day_bcd;
    unsigned char hour_bcd, minute_bcd, second_bcd;

    /* Temporarily disable updates to the clock */
    ctrl = *RTC_CTRL;
    *RTC_CTRL = ctrl | RTC_UTI;
    log(LOG_INFO, "RTC Disabled");
    log_num(LOG_INFO, "RTC Rates: ", *RTC_RATES);
    log_num(LOG_INFO, "RTC Enables: ", *RTC_ENABLES);
    log_num(LOG_INFO, "RTC Flags: ", *RTC_FLAGS);
    log_num(LOG_INFO, "RTC Control: ", *RTC_CTRL);

    if (*RTC_CTRL & RTC_2412) {
        time->is_24hours = 1;
    } else {
        time->is_24hours = 0;
    }

    century_bcd = *RTC_CENTURY;
    year_bcd = *RTC_YEAR;
    month_bcd = *RTC_MONTH;
    day_bcd = *RTC_DAY;
    hour_bcd = *RTC_HOUR;
    minute_bcd = *RTC_MIN;
    second_bcd = *RTC_SEC;

    /* Re-enable updates to the clock */
    *RTC_CTRL = ctrl;
    log(LOG_INFO, "RTC Enabled");
    log_num(LOG_INFO, "RTC Rates: ", *RTC_RATES);
    log_num(LOG_INFO, "RTC Enables: ", *RTC_ENABLES);
    log_num(LOG_INFO, "RTC Flags: ", *RTC_FLAGS);
    log_num(LOG_INFO, "RTC Control: ", *RTC_CTRL);

    log_num(LOG_INFO, "Century: ", century_bcd);
    log_num(LOG_INFO, "Year: ", year_bcd);
    log_num(LOG_INFO, "Month: ", month_bcd);
    log_num(LOG_INFO, "Day: ", day_bcd);
    log_num(LOG_INFO, "Hour: ", hour_bcd);
    log_num(LOG_INFO, "Minute: ", minute_bcd);
    log_num(LOG_INFO, "Second: ", second_bcd);

    /* Fill out the time record */

    time->year = bcd_to_i(century_bcd) * 100 + bcd_to_i(year_bcd);
    time->month = bcd_to_i(month_bcd);
    time->day = bcd_to_i(day_bcd);
    time->hour = bcd_to_i(hour_bcd & 0x7f);
    time->is_pm = ((hour_bcd & 0x80) == 0x80) ? 1 : 0;
    time->minute = bcd_to_i(minute_bcd);
    time->second = bcd_to_i(second_bcd);
}

/*
 * Get the number of ticks since the system last booted.
 *
 * NOTE: a tick is almost, but not quite, 1ms. The RTC periodic interrupt
 *       period does not line up with a 1ms timer, but it comes close.
 *       Therefore, a tick will be 976.5625 microseconds... a little faster
 *       than 1ms.
 *
 * Returns:
 * the number of ticks since the last reset
 */
long rtc_get_ticks() {
    long result = 0;

    int_disable(INT_RTC);   /* Make sure we aren't changing the tick counter during the query */
    result = rtc_ticks;
    int_enable(INT_RTC);

    return rtc_ticks;
}