UBOOT RTC驱动流程


typedef enum {
    RTC_ENABLE,
    RTC_DISABLE
} RTC_ACCESS;


static inline void SetRTC_Access(RTC_ACCESS a)
{
    struct s3c24x0_rtc *rtc = s3c24x0_get_base_rtc();

    switch (a) {
    case RTC_ENABLE:
        writeb(readb(&rtc->RTCCON) | 0x01, &rtc->RTCCON);
        break;

    case RTC_DISABLE:
        writeb(readb(&rtc->RTCCON) & ~0x01, &rtc->RTCCON);
        break;
    }
}

/* ------------------------------------------------------------------------- */

int rtc_get(struct rtc_time *tmp)
{
    struct s3c24x0_rtc *rtc = s3c24x0_get_base_rtc();
    uchar sec, min, hour, mday, wday, mon, year;
    uchar a_sec, a_min, a_hour, a_date, a_mon, a_year, a_armed;

    /* enable access to RTC registers */
    SetRTC_Access(RTC_ENABLE);

    /* read RTC registers */
    do {
        sec = readb(&rtc->BCDSEC);
        min = readb(&rtc->BCDMIN);
        hour = readb(&rtc->BCDHOUR);
        mday = readb(&rtc->BCDDATE);
        wday = readb(&rtc->BCDDAY);
        mon = readb(&rtc->BCDMON);
        year = readb(&rtc->BCDYEAR);
    } while (sec != readb(&rtc->BCDSEC));

    /* read ALARM registers */
    a_sec = readb(&rtc->ALMSEC);
    a_min = readb(&rtc->ALMMIN);
    a_hour = readb(&rtc->ALMHOUR);
    a_date = readb(&rtc->ALMDATE);
    a_mon = readb(&rtc->ALMMON);
    a_year = readb(&rtc->ALMYEAR);
    a_armed = readb(&rtc->RTCALM);

    /* disable access to RTC registers */
    SetRTC_Access(RTC_DISABLE);

#ifdef RTC_DEBUG
    printf("Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
     "hr: %02x min: %02x sec: %02x\n",
     year, mon, mday, wday, hour, min, sec);
    printf("Alarms: %02x: year: %02x month: %02x date: %02x hour: "
     "%02x min: %02x sec: %02x\n",
     a_armed, a_year, a_mon, a_date, a_hour, a_min, a_sec);
#endif

    tmp->tm_sec = bcd2bin(sec & 0x7F);
    tmp->tm_min = bcd2bin(min & 0x7F);
    tmp->tm_hour = bcd2bin(hour & 0x3F);
    tmp->tm_mday = bcd2bin(mday & 0x3F);
    tmp->tm_mon = bcd2bin(mon & 0x1F);
    tmp->tm_year = bcd2bin(year);
    tmp->tm_wday = bcd2bin(wday & 0x07);
    if (tmp->tm_year < 70)
        tmp->tm_year += 2000;
    else
        tmp->tm_year += 1900;
    tmp->tm_yday = 0;
    tmp->tm_isdst = 0;
#ifdef RTC_DEBUG
    printf("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);
#endif

    return 0;
}

int rtc_set(struct rtc_time *tmp)
{
    struct s3c24x0_rtc *rtc = s3c24x0_get_base_rtc();
    uchar sec, min, hour, mday, wday, mon, year;

#ifdef RTC_DEBUG
    printf("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);
#endif
    year = bin2bcd(tmp->tm_year % 100);
    mon = bin2bcd(tmp->tm_mon);
    wday = bin2bcd(tmp->tm_wday);
    mday = bin2bcd(tmp->tm_mday);
    hour = bin2bcd(tmp->tm_hour);
    min = bin2bcd(tmp->tm_min);
    sec = bin2bcd(tmp->tm_sec);

    /* enable access to RTC registers */
    SetRTC_Access(RTC_ENABLE);

    /* write RTC registers */
    writeb(sec, &rtc->BCDSEC);
    writeb(min, &rtc->BCDMIN);
    writeb(hour, &rtc->BCDHOUR);
    writeb(mday, &rtc->BCDDATE);
    writeb(wday, &rtc->BCDDAY);
    writeb(mon, &rtc->BCDMON);
    writeb(year, &rtc->BCDYEAR);

    /* disable access to RTC registers */
    SetRTC_Access(RTC_DISABLE);

    return 0;
}

void rtc_reset(void)
{
    struct s3c24x0_rtc *rtc = s3c24x0_get_base_rtc();

    writeb((readb(&rtc->RTCCON) & ~0x06) | 0x08, &rtc->RTCCON);
    writeb(readb(&rtc->RTCCON) & ~(0x08 | 0x01), &rtc->RTCCON);
}

#endif