/*
    ChibiOS - Copyright (C) 2006..2015 Giovanni Di Sirio.

    This file is part of ChibiOS.

    ChibiOS is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.

    ChibiOS is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/
/*
   Concepts and parts of this file have been contributed by Uladzimir Pylinsky
   aka barthess.
 */

/**
 * @file    rtc.c
 * @brief   RTC Driver code.
 *
 * @addtogroup RTC
 * @{
 */

#include "hal.h"

#if (HAL_USE_RTC == TRUE) || defined(__DOXYGEN__)

/*===========================================================================*/
/* Driver local definitions.                                                 */
/*===========================================================================*/

/*===========================================================================*/
/* Driver exported variables.                                                */
/*===========================================================================*/

/*===========================================================================*/
/* Driver local variables and types.                                         */
/*===========================================================================*/

/*
 * Lookup table with months' length
 */
static const uint8_t month_len[12] = {
  31, 30, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
};

/*===========================================================================*/
/* Driver local functions.                                                   */
/*===========================================================================*/

/*===========================================================================*/
/* Driver exported functions.                                                */
/*===========================================================================*/

/**
 * @brief   RTC Driver initialization.
 * @note    This function is implicitly invoked by @p halInit(), there is
 *          no need to explicitly initialize the driver.
 *
 * @init
 */
void rtcInit(void) {

  rtc_lld_init();
}

/**
 * @brief   Initializes a generic RTC driver object.
 * @details The HW dependent part of the initialization has to be performed
 *          outside, usually in the hardware initialization code.
 *
 * @param[out] rtcp     pointer to RTC driver structure
 *
 * @init
 */
void rtcObjectInit(RTCDriver *rtcp) {

#if RTC_HAS_STORAGE == TRUE
  rtcp->vmt = &_rtc_lld_vmt;
#else
  (void)rtcp;
#endif
}

/**
 * @brief   Set current time.
 * @note    This function can be called from any context but limitations
 *          could be imposed by the low level implementation. It is
 *          guaranteed that the function can be called from thread
 *          context.
 * @note    The function can be reentrant or not reentrant depending on
 *          the low level implementation.
 *
 * @param[in] rtcp      pointer to RTC driver structure
 * @param[in] timespec  pointer to a @p RTCDateTime structure
 *
 * @special
 */
void rtcSetTime(RTCDriver *rtcp, const RTCDateTime *timespec) {

  osalDbgCheck((rtcp != NULL) && (timespec != NULL));

  rtc_lld_set_time(rtcp, timespec);
}

/**
 * @brief   Get current time.
 * @note    This function can be called from any context but limitations
 *          could be imposed by the low level implementation. It is
 *          guaranteed that the function can be called from thread
 *          context.
 * @note    The function can be reentrant or not reentrant depending on
 *          the low level implementation.
 *
 * @param[in] rtcp      pointer to RTC driver structure
 * @param[out] timespec pointer to a @p RTCDateTime structure
 *
 * @special
 */
void rtcGetTime(RTCDriver *rtcp, RTCDateTime *timespec) {

  osalDbgCheck((rtcp != NULL) && (timespec != NULL));

  rtc_lld_get_time(rtcp, timespec);
}

#if (RTC_ALARMS > 0) || defined(__DOXYGEN__)
/**
 * @brief   Set alarm time.
 * @note    This function can be called from any context but limitations
 *          could be imposed by the low level implementation. It is
 *          guaranteed that the function can be called from thread
 *          context.
 * @note    The function can be reentrant or not reentrant depending on
 *          the low level implementation.
 *
 * @param[in] rtcp      pointer to RTC driver structure
 * @param[in] alarm     alarm identifier
 * @param[in] alarmspec pointer to a @p RTCAlarm structure or @p NULL
 *
 * @special
 */
void rtcSetAlarm(RTCDriver *rtcp,
                 rtcalarm_t alarm,
                 const RTCAlarm *alarmspec) {

  osalDbgCheck((rtcp != NULL) && (alarm < (rtcalarm_t)RTC_ALARMS));

  rtc_lld_set_alarm(rtcp, alarm, alarmspec);
}

/**
 * @brief   Get current alarm.
 * @note    If an alarm has not been set then the returned alarm specification
 *          is not meaningful.
 * @note    This function can be called from any context but limitations
 *          could be imposed by the low level implementation. It is
 *          guaranteed that the function can be called from thread
 *          context.
 * @note    The function can be reentrant or not reentrant depending on
 *          the low level implementation.
 *
 * @param[in] rtcp      pointer to RTC driver structure
 * @param[in] alarm     alarm identifier
 * @param[out] alarmspec pointer to a @p RTCAlarm structure
 *
 * @special
 */
void rtcGetAlarm(RTCDriver *rtcp,
                 rtcalarm_t alarm,
                 RTCAlarm *alarmspec) {

  osalDbgCheck((rtcp != NULL) &&
               (alarm < (rtcalarm_t)RTC_ALARMS) &&
               (alarmspec != NULL));

  rtc_lld_get_alarm(rtcp, alarm, alarmspec);
}
#endif /* RTC_ALARMS > 0 */

#if (RTC_SUPPORTS_CALLBACKS == TRUE) || defined(__DOXYGEN__)
/**
 * @brief   Enables or disables RTC callbacks.
 * @details This function enables or disables the callback, use a @p NULL
 *          pointer in order to disable it.
 * @note    This function can be called from any context but limitations
 *          could be imposed by the low level implementation. It is
 *          guaranteed that the function can be called from thread
 *          context.
 * @note    The function can be reentrant or not reentrant depending on
 *          the low level implementation.
 *
 * @param[in] rtcp      pointer to RTC driver structure
 * @param[in] callback  callback function pointer or @p NULL
 *
 * @special
 */
void rtcSetCallback(RTCDriver *rtcp, rtccb_t callback) {

  osalDbgCheck(rtcp != NULL);

  rtc_lld_set_callback(rtcp, callback);
}
#endif /* RTC_SUPPORTS_CALLBACKS == TRUE */

/**
 * @brief   Convert @p RTCDateTime to broken-down time structure.
 *
 * @param[in]  timespec   pointer to a @p RTCDateTime structure
 * @param[out] timp       pointer to a broken-down time structure
 *
 * @api
 */
void rtcConvertDateTimeToStructTm(const RTCDateTime *timespec,
                                  struct tm *timp) {
  int tmp;

  timp->tm_year  = (int)timespec->year + (1980 - 1900);
  timp->tm_mon   = (int)timespec->month - 1;
  timp->tm_mday  = (int)timespec->day;
  timp->tm_isdst = (int)timespec->dstflag;

  tmp = (int)timespec->millisecond / 1000;
  timp->tm_sec  = tmp % 60;
  tmp -= timp->tm_sec;
  timp->tm_min  = (tmp % 3600) / 60;
  tmp -= timp->tm_min * 60;
  timp->tm_hour = tmp / 3600;
}

/**
 * @brief   Convert broken-down time structure to @p RTCDateTime.
 *
 * @param[in] timp        pointer to a broken-down time structure
 * @param[in] tv_msec     milliseconds value
 * @param[out] timespec   pointer to a @p RTCDateTime structure
 *
 * @api
 */
void rtcConvertStructTmToDateTime(const struct tm *timp,
                                  uint32_t tv_msec,
                                  RTCDateTime *timespec) {

  /*lint -save -e9034 [10.4] Verified assignments to bit fields.*/
  timespec->year      = (uint32_t)timp->tm_year - (1980U - 1900U);
  timespec->month     = (uint32_t)timp->tm_mon + 1U;
  timespec->day       = (uint32_t)timp->tm_mday;
  timespec->dayofweek = (uint32_t)timp->tm_wday + 1U;
  if (-1 == timp->tm_isdst) {
    timespec->dstflag = 0U;  /* set zero if dst is unknown */
  }
  else {
    timespec->dstflag = (uint32_t)timp->tm_isdst;
  }
  /*lint -restore*/
  /*lint -save -e9033 [10.8] Verified assignments to bit fields.*/
  timespec->millisecond = tv_msec + (uint32_t)((timp->tm_hour * 3600) +
                                               (timp->tm_min * 60) +
                                               (timp->tm_sec * 1000));
  /*lint -restore*/
}

/**
 * @brief   Get current time in format suitable for usage in FAT file system.
 * @note    The information about day of week and DST is lost in DOS
 *          format, the second field loses its least significant bit.
 *
 * @param[out] timespec pointer to a @p RTCDateTime structure
 * @return              FAT date/time value.
 *
 * @api
 */
uint32_t rtcConvertDateTimeToFAT(const RTCDateTime *timespec) {
  uint32_t fattime;
  uint32_t sec, min, hour, day, month, tmp;

  tmp = timespec->millisecond / 1000U;
  sec = tmp % 60U;
  min = (tmp - sec) % 3600U;
  hour = ((tmp - sec) - (min * 60U)) / 3600U;
  day = timespec->day;
  month = timespec->month;

  /* handle DST flag */
  if (1U == timespec->dstflag) {
    hour += 1U;
    if (hour == 24U) {
      hour = 0U;
      day += 1U;
      if (day > month_len[month - 1U]) {
        day = 1U;
        month += 1U;
      }
    }
  }

  fattime  = sec   >> 1U;
  fattime |= min   << 5U;
  fattime |= hour  << 11U;
  fattime |= day   << 16U;
  fattime |= month << 21U;
  fattime |= (uint32_t)timespec->year << 25U;

  return fattime;
}

#endif /* HAL_USE_RTC == TRUE */

/** @} */