/*
 * Copyright 2008-2010, Freie Universitaet Berlin (FUB). All rights reserved.
 * Copyright 2014 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.
 */

#include <sys/time.h>
#include <stdint.h>
#include <string.h>

#include "kernel_types.h"

/* cpu */
#include "periph/rtc.h"
#include "VIC.h"
#include "lpc2387.h"
#include "lpm.h"

#define ENABLE_DEBUG (0)
#include "debug.h"

/* Alarm callback */
static rtc_alarm_cb_t _cb;

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

/* internal function to set time based on time_t */
static void _rtc_set(time_t time);

void RTC_IRQHandler(void) __attribute__((interrupt("IRQ")));

void rtc_init(void)
{
    PCONP |= BIT9;
    RTC_AMR = 0xff;                         /* disable alarm irq */
    RTC_CIIR = 0;                           /* disable increase irq */
    RTC_CISS = 0;                           /* disable subsecond irq */

    INTWAKE |= BIT15;                       /* rtc irq wakes up mcu from power down */

    RTC_CCR = CCR_CLKSRC;                   /* Clock from external 32 kHz Osc. */

    /* initialize clock with valid unix compatible values
     * If RTC_YEAR contains an value larger unix time_t we must reset. */
    if (RTC_YEAR > 2037) {
        _rtc_set(0);
    }

    DEBUG("%2lu.%2lu.%4lu  %2lu:%2lu:%2lu\n",
            RTC_DOM, RTC_MONTH, RTC_YEAR, RTC_HOUR, RTC_MIN, RTC_SEC);
}

/**
 * @brief   Sets the current time in broken down format directly from to RTC
 * @param[in]   localt      Pointer to structure with time to set
 */
int rtc_set_time(struct tm *localt)
{
    if (localt == NULL) {
        return -1;
    }

    /* set clock */
    RTC_SEC = localt->tm_sec;
    RTC_MIN = localt->tm_min;
    RTC_HOUR = localt->tm_hour;
    RTC_DOM = localt->tm_mday;
    RTC_DOW = localt->tm_wday;
    RTC_DOY = localt->tm_yday;
    RTC_MONTH = localt->tm_mon + 1;
    RTC_YEAR = localt->tm_year;

    return 0;
}

int rtc_get_time(struct tm *localt)
{
    if (localt != NULL) {
        localt->tm_sec = RTC_SEC;
        localt->tm_min = RTC_MIN;
        localt->tm_hour = RTC_HOUR;
        localt->tm_mday = RTC_DOM;
        localt->tm_wday = RTC_DOW;
        localt->tm_yday = RTC_DOY;
        localt->tm_mon = RTC_MONTH - 1;
        localt->tm_year = RTC_YEAR;
        localt->tm_isdst = -1; /* not available */
        return 0;
    }
    return -1;
}


int rtc_set_alarm(struct tm *localt, rtc_alarm_cb_t cb, void *arg)
{
    (void) arg;
    if (localt != NULL) {
        RTC_ALSEC = localt->tm_sec;
        RTC_ALMIN = localt->tm_min;
        RTC_ALHOUR = localt->tm_hour;
        RTC_ALDOM = localt->tm_mday;
        RTC_ALDOW = localt->tm_wday;
        RTC_ALDOY = localt->tm_yday;
        RTC_ALMON = localt->tm_mon + 1;
        RTC_ALYEAR = localt->tm_year;
        RTC_AMR = 0;                                            /* set wich alarm fields to check */
        DEBUG("alarm set %2lu.%2lu.%4lu  %2lu:%2lu:%2lu\n",
              RTC_ALDOM, RTC_ALMON, RTC_ALYEAR, RTC_ALHOUR, RTC_ALMIN, RTC_ALSEC);

        _cb = cb;
        return 0;
    }
    else if (cb == NULL) {
        return -1;
    }

    RTC_AMR = 0xff;
    return -2;
}

int rtc_get_alarm(struct tm *localt)
{
    if (localt != NULL) {
        localt->tm_sec = RTC_ALSEC;
        localt->tm_min = RTC_ALMIN;
        localt->tm_hour = RTC_ALHOUR;
        localt->tm_mday = RTC_ALDOM;
        localt->tm_wday = RTC_ALDOW;
        localt->tm_yday = RTC_ALDOY;
        localt->tm_mon = RTC_ALMON - 1;
        localt->tm_year = RTC_ALYEAR;
        localt->tm_isdst = -1; /* not available */

        return 0;
    }

    return -1;
}

void rtc_clear_alarm(void)
{
    RTC_AMR = 0xff;
}

void rtc_poweron(void)
{
    PCONP |= BIT9;
    RTC_ILR = (ILR_RTSSF | ILR_RTCCIF | ILR_RTCALF);    /* clear interrupt flags */
    RTC_CCR |= CCR_CLKEN;                               /* enable clock */
    install_irq(RTC_INT, &RTC_IRQHandler, IRQP_RTC);    /* install interrupt handler */
}

void rtc_poweroff(void)
{
    RTC_CCR &= ~CCR_CLKEN;  /* disable clock */
    install_irq(RTC_INT, NULL, 0);
    RTC_ILR = 0;
    PCONP &= ~BIT9;
}

void RTC_IRQHandler(void)
{
    lpm_begin_awake();

    if (RTC_ILR & ILR_RTSSF) {
        /* sub second interrupt (does not need flag-clearing) */
    }
    else if (RTC_ILR & ILR_RTCCIF) {
        /* counter increase interrupt */
    }
    else if (RTC_ILR & ILR_RTCALF) {
        RTC_ILR |= ILR_RTCALF;
        RTC_AMR = 0xff;                     /* disable alarm irq */
        if (_cb) {
            _cb(_cb_arg);
        }
        DEBUG("Ring\n");
        lpm_end_awake();
    }

    VICVectAddr = 0;                        /* Acknowledge Interrupt */
}

static void _rtc_set(time_t time)
{
    struct tm *localt;
    localt = localtime(&time);                      /* convert seconds to broken-down time */
    rtc_set_time(localt);
}