/****************************************************************************
 * drivers/timers/arch_rtc.c
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.  The
 * ASF licenses this file to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the
 * License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations
 * under the License.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <nuttx/arch.h>
#include <nuttx/timers/arch_rtc.h>

/****************************************************************************
 * Private Data
 ****************************************************************************/

static FAR struct rtc_lowerhalf_s *g_rtc_lower;

/****************************************************************************
 * Public Data
 ****************************************************************************/

/* Variable determines the state of the RTC module.
 *
 * After initialization value is set to 'true' if RTC starts successfully.
 * The value can be changed to false also during operation if RTC for
 * some reason fails.
 */

volatile bool g_rtc_enabled = false;

/****************************************************************************
 * Public Functions
 ****************************************************************************/

void up_rtc_set_lowerhalf(FAR struct rtc_lowerhalf_s *lower)
{
  g_rtc_lower   = lower;
  g_rtc_enabled = true;

#ifdef CONFIG_RTC_EXTERNAL
  clock_synchronize();
#endif
}

/****************************************************************************
 * Name: up_rtc_time
 *
 * Description:
 *   Get the current time in seconds. This is similar to the standard time()
 *   function. This interface is only required if the low-resolution RTC/
 *   counter hardware implementation selected.  It is only used by the RTOS
 *   during initialization to set up the system time when CONFIG_RTC is set
 *   but neither CONFIG_RTC_HIRES nor CONFIG_RTC_DATETIME are set.
 *
 * Input Parameters:
 *   None
 *
 * Returned Value:
 *   The current time in seconds.
 *
 ****************************************************************************/

#ifndef CONFIG_RTC_HIRES
time_t up_rtc_time(void)
{
  time_t time = 0;

  if (g_rtc_lower != NULL)
    {
      struct rtc_time rtctime;

      if (g_rtc_lower->ops->rdtime(g_rtc_lower, &rtctime) == 0)
        {
          time = timegm((FAR struct tm *)&rtctime);
        }
    }

  return time;
}
#endif

/****************************************************************************
 * Name: up_rtc_gettime
 *
 * Description:
 *   Get the current time from the high resolution RTC clock/counter.  This
 *   interface is only supported by the high-resolution RTC/counter hardware
 *   implementation. It is used to replace the system timer.
 *
 * Input Parameters:
 *   tp - The location to return the high resolution time value.
 *
 * Returned Value:
 *   Zero (OK) on success; a negated errno value on failure.
 *
 ****************************************************************************/

#ifdef CONFIG_RTC_HIRES
int up_rtc_gettime(FAR struct timespec *tp)
{
  int ret = -EAGAIN;

  if (g_rtc_lower != NULL)
    {
      struct rtc_time rtctime;

      ret = g_rtc_lower->ops->rdtime(g_rtc_lower, &rtctime);
      if (ret == 0)
        {
          tp->tv_sec = timegm((FAR struct tm *)&rtctime);
          tp->tv_nsec = rtctime.tm_nsec;
        }
    }

  return ret;
}
#endif

/****************************************************************************
 * Name: up_rtc_getdatetime
 *
 * Description:
 *   Get the current date and time from the date/time RTC.  This interface
 *   is only supported by the date/time RTC hardware implementation.
 *   It is used to replace the system timer.  It is only used by the RTOS
 *   during initialization to set up the system time when CONFIG_RTC and
 *   CONFIG_RTC_DATETIME are selected (and CONFIG_RTC_HIRES is not).
 *
 *   NOTE: Some date/time RTC hardware is capability of sub-second accuracy.
 *   That sub-second accuracy is lost in this interface.  However, since the
 *   system time is reinitialized on each power-up/reset, there will be no
 *   timing inaccuracy in the long run.
 *
 * Input Parameters:
 *   tp - The location to return the high resolution time value.
 *
 * Returned Value:
 *   Zero (OK) on success; a negated errno value on failure.
 *
 ****************************************************************************/

#ifdef CONFIG_RTC_DATETIME
int up_rtc_getdatetime(FAR struct tm *tp)
{
  int ret = -EAGAIN;

  if (g_rtc_lower != NULL)
    {
      struct rtc_time rtctime;

      ret = g_rtc_lower->ops->rdtime(g_rtc_lower, &rtctime);
      if (ret == 0)
        {
          *tp = *((FAR struct tm *)&rtctime);
        }
    }

  return ret;
}
#endif

/****************************************************************************
 * Name: up_rtc_getdatetime_with_subseconds
 *
 * Description:
 *   Get the current date and time from the date/time RTC.  This interface
 *   is only supported by the date/time RTC hardware implementation.
 *   It is used to replace the system timer.  It is only used by the RTOS
 *   during initialization to set up the system time when CONFIG_RTC and
 *   CONFIG_RTC_DATETIME are selected (and CONFIG_RTC_HIRES is not).
 *
 *   NOTE: This interface exposes sub-second accuracy capability of RTC
 *   hardware. This interface allow maintaining timing accuracy when system
 *   time needs constant resynchronization with RTC, for example on MCU with
 *   low-power state that stop system timer.
 *
 * Input Parameters:
 *   tp   - The location to return the high resolution time value.
 *   nsec - The location to return the sub-second time value.
 *
 * Returned Value:
 *   Zero (OK) on success; a negated errno on failure
 *
 ****************************************************************************/

#if defined(CONFIG_RTC_DATETIME) && defined(CONFIG_ARCH_HAVE_RTC_SUBSECONDS)
int up_rtc_getdatetime_with_subseconds(FAR struct tm *tp, FAR long *nsec)
{
  int ret = -EAGAIN;

  if (g_rtc_lower != NULL)
    {
      struct rtc_time rtctime;

      ret = g_rtc_lower->ops->rdtime(g_rtc_lower, &rtctime);
      if (ret == 0)
        {
          *tp = *((FAR struct tm *)&rtctime);
          *nsec = rtctime.tm_nsec;
        }
    }

  return ret;
}
#endif

/****************************************************************************
 * Name: up_rtc_settime
 *
 * Description:
 *   Set the RTC to the provided time.  All RTC implementations must be able
 *   to set their time based on a standard timespec.
 *
 * Input Parameters:
 *   tp - the time to use
 *
 * Returned Value:
 *   Zero (OK) on success; a negated errno value on failure.
 *
 ****************************************************************************/

int up_rtc_settime(FAR const struct timespec *tp)
{
  int ret = -EAGAIN;

  if (g_rtc_lower != NULL)
    {
      struct rtc_time rtctime;

      gmtime_r(&tp->tv_sec, (FAR struct tm *)&rtctime);
#if defined(CONFIG_RTC_HIRES) || defined(CONFIG_ARCH_HAVE_RTC_SUBSECONDS)
      rtctime.tm_nsec = tp->tv_nsec;
#endif
      ret = g_rtc_lower->ops->settime(g_rtc_lower, &rtctime);
    }

  return ret;
}