RIOT/cpu/cc430/periph/rtc.c

/*
 * Copyright 2010, Freie Universitaet Berlin (FUB).
 * Copyright 2013, INRIA.
 *
 * This file is subject to the terms and conditions of the GNU Lesser
 * General Public License v2.1. See the file LICENSE in the top level
 * directory for more details.
 */

/**
 * @ingroup driver_periph_rtc
 * @file
 * @brief       CC430 real time clock implementation
 * @author      Oliver Hahm <oliver.hahm@inria.fr>
 */

#include <string.h>
#include <legacymsp430.h>
#include "irq.h"
#include "cpu.h"
#include "cc430-rtc.h"

/* Alarm callback */
static rtc_alarm_cb_t _cb;

/* Argument to alarm callback */
static void *_cb_arg;

static struct tm time_to_set;
static int set_time = 0;
kernel_pid_t rtc_second_pid = KERNEL_PID_UNDEF;

void rtc_init(void)
{
    /* Set to calendar mode */
    RTCCTL1 |= RTCMODE_H;
}

void rtc_poweron(void)
{
    /* Set RTC operational */
    RTCCTL1 &= ~RTCHOLD_H;
}

void rtc_poweroff(void)
{
    /* Stop RTC */
    RTCCTL1 |= RTCHOLD_H;
}

int rtc_set_time(struct tm *localt)
{
    if (localt == NULL) {
        return -1;
    }

    /* copy time to be set */
    memcpy(&time_to_set, localt, sizeof(struct tm));
    set_time = 1;
    return 0;
}

/*---------------------------------------------------------------------------
time_t rtc_time(void) {
    time_t sec;
    struct tm t;
    rtc_get_localtime(&t);
    sec = mktime(&t);
    return sec;
}
*/

int rtc_get_time(struct tm *localt)
{
    uint8_t success = 0;
    uint8_t i;
    uint16_t tmpyear;

    if (localt == NULL) {
        return -1;
    }

    while (!success) {
        for (i = 0; i < 8; i++) {
            /* try again when RTC is in transition */
            if (!(RTCCTL1 & RTCRDY_H)) {
                break;
            }

            switch(i) {
                case 0:
                    localt->tm_sec = RTCSEC;
                    break;

                case 1:
                    localt->tm_min = RTCMIN;
                    break;

                case 2:
                    localt->tm_hour = RTCHOUR;
                    break;

                case 3:
                    localt->tm_mday = RTCDAY;
                    break;

                case 4:
                    localt->tm_wday = RTCDOW;
                    break;

                case 5:
                    localt->tm_mon = RTCMON - 1;
                    break;

                case 6:
                    tmpyear = RTCYEARL;
                    tmpyear |= (RTCYEARH << 0x08);
                    localt->tm_year = tmpyear - 1900;
                    break;

                default:
                    success = 1;
                    break;
            }
        }
    }

    return 0;
}

int rtc_set_alarm(struct tm *localt, rtc_alarm_cb_t cb, void *arg)
{
    if (localt != NULL) {
        RTCAMIN = localt->tm_min;
        RTCAMIN |= BIT7;
        RTCAHOUR = localt->tm_hour;
        RTCAHOUR |= BIT7;
        RTCADOW = localt->tm_wday;
        RTCADOW |= BIT7;
        RTCADAY = localt->tm_mday;
        RTCADAY |= BIT7;

        RTCCTL0 |= RTCAIE;
        return 0;
    }

    else if (cb == NULL) {
        return -1;
    }

    return -2;
}

int rtc_get_alarm(struct tm *localt)
{
     if (localt != NULL) {
        localt->tm_sec = -1;
        localt->tm_min = RTCAMIN;
        localt->tm_hour = RTCAHOUR;
        localt->tm_mday = -1;
        localt->tm_wday = RTCADOW;
        localt->tm_yday = -1;
        localt->tm_mon = - 1;
        localt->tm_year = -1;
        localt->tm_isdst = -1; /* not available */

        return 0;
    }

    return -1;
}

void rtc_clear_alarm(void)
{
    /* reset all AE bits */
    RTCAHOUR &= ~BIT7;
    RTCAMIN  &= ~BIT7;
    RTCADAY  &= ~BIT7;
    RTCADOW  &= ~BIT7;

    /* reset alarm interrupt enable */
    RTCCTL0 &= ~RTCAIE;
}

interrupt(RTC_VECTOR) __attribute__((naked)) rtc_isr(void)
{
    __enter_isr();

    /* RTC is save to write for up to one second now */
    if (RTCIV == RTC_RTCRDYIFG) {
        /* disable interrupt */
        //RTCCTL0 &= ~RTCRDYIE;

        if (set_time) {
            set_time = 0;
            /* set previous set time and reset it */
            RTCSEC = time_to_set.tm_sec;
            RTCMIN = time_to_set.tm_min;
            RTCHOUR = time_to_set.tm_hour;
            RTCDAY = time_to_set.tm_mday;
            RTCDOW = time_to_set.tm_wday;
            RTCMON = time_to_set.tm_mon + 1;
            RTCYEARL = (time_to_set.tm_year + 1900) & 0xFF;
            RTCYEARH = (time_to_set.tm_year + 1900) >> 0x08;
        }

        if (rtc_second_pid != KERNEL_PID_UNDEF) {
            static msg_t m;
            m.type = RTCSEC;
            msg_send_int(&m, rtc_second_pid);
        }
    }
    /* RTC alarm */
    else if (RTCIV == RTC_RTCAIFG) {
        if (_cb) {
            _cb(_cb_arg);
        }
    }

    __exit_isr();
}