/* SPDX-License-Identifier: BSD-2-Clause */

/**
 * @file
 *
 * @ingroup RTEMSScoreTOD
 * @ingroup RTEMSScoreTODHooks
 *
 * @brief This header file provides the interfaces of the
 *   @ref RTEMSScoreTOD and the @ref RTEMSScoreTODHooks.
 */

/*
 *  COPYRIGHT (c) 1989-2009.
 *  On-Line Applications Research Corporation (OAR).
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef _RTEMS_SCORE_TODIMPL_H
#define _RTEMS_SCORE_TODIMPL_H

#include <rtems/score/status.h>
#include <rtems/score/timestamp.h>
#include <rtems/score/timecounterimpl.h>
#include <rtems/score/watchdog.h>
#include <rtems/score/watchdogticks.h>

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

#ifdef __cplusplus
extern "C" {
#endif

/**
 * @defgroup RTEMSScoreTOD Time of Day Handler
 *
 * @ingroup RTEMSScore
 *
 * @brief This group contains the Time of Day Handler implementation.
 *
 * The following constants are related to the time of day and are
 * independent of RTEMS.
 *
 * @{
 */

/**
 *  This constant represents the number of seconds in a minute.
 */
#define TOD_SECONDS_PER_MINUTE (uint32_t)60

/**
 *  This constant represents the number of minutes per hour.
 */
#define TOD_MINUTES_PER_HOUR   (uint32_t)60

/**
 *  This constant represents the number of months in a year.
 */
#define TOD_MONTHS_PER_YEAR    (uint32_t)12

/**
 *  This constant represents the number of days in a non-leap year.
 */
#define TOD_DAYS_PER_YEAR      (uint32_t)365

/**
 *  This constant represents the number of hours per day.
 */
#define TOD_HOURS_PER_DAY      (uint32_t)24

/**
 *  This constant represents the number of seconds in a day which does
 *  not include a leap second.
 */
#define TOD_SECONDS_PER_DAY    (uint32_t) (TOD_SECONDS_PER_MINUTE * \
                                TOD_MINUTES_PER_HOUR   * \
                                TOD_HOURS_PER_DAY)

/**
 *  This constant represents the number of seconds in a non-leap year.
 */
#define TOD_SECONDS_PER_NON_LEAP_YEAR (365 * TOD_SECONDS_PER_DAY)

/**
 *  This constant represents the number of millisecond in a second.
 */
#define TOD_MILLISECONDS_PER_SECOND     (uint32_t)1000

/**
 *  This constant represents the number of microseconds in a second.
 */
#define TOD_MICROSECONDS_PER_SECOND     (uint32_t)1000000

/**
 *  This constant represents the number of nanoseconds in a second.
 */
#define TOD_NANOSECONDS_PER_SECOND      (uint32_t)1000000000

/**
 *  This constant represents the number of nanoseconds in a mircosecond.
 */
#define TOD_NANOSECONDS_PER_MICROSECOND (uint32_t)1000

/**@}*/

/**
 *  Seconds from January 1, 1970 to January 1, 1988.  Used to account for
 *  differences between POSIX API and RTEMS core. The timespec format time
 *  is kept in POSIX compliant form.
 */
#define TOD_SECONDS_1970_THROUGH_1988 \
  (((1987 - 1970 + 1)  * TOD_SECONDS_PER_NON_LEAP_YEAR) + \
  (4 * TOD_SECONDS_PER_DAY))

/**
 * @brief Seconds from 1970-01-01T00:00:00Z to 2400-01-01T00:00:00Z.
 *
 * This is the latest time of day which should be set by _TOD_Set().  The year
 * 2400 was chosen to guarantee a defined CLOCK_REALTIME within the range of a
 * system uptime of about 114 years.
 */
#define TOD_SECONDS_1970_THROUGH_2400 13569465600

/**
 *  @brief Earliest year to which an time of day can be initialized.
 *
 *  The following constant define the earliest year to which an
 *  time of day can be initialized.  This is considered the
 *  epoch.
 */
#define TOD_BASE_YEAR 1988

/**
 *  @brief Latest year to which a time of day can be initialized.
 *
 *  The following constant defines the latest year to which an
 *  RTEMS time of day can be set using rtems_clock_set().
 *
 *  32 bits can accept as latest point in time 2106-Feb-7 6:28:15
 *  but to simplify the implementation, is was decided to only
 *  check that the year is not greater than the year of this constant.
 *  The year 2099 was chosen because all years evenly divisible by 4 from 1988
 *  to 2099 are leap years.  In this time frame, years evenly divisible by 100
 *  are no leap years unless they are evenly divisible by 400.  Thus the year
 *  2000 is a leap year.
 *
 *  The internal CLOCK_REALTIME can run centuries longer but in
 *  contrast to the POSIX API, the RTEMS Classic API does not
 *  support this for efficiency reasons.
 */
#define TOD_LATEST_YEAR 2099

/**
 * @addtogroup RTEMSScoreTOD
 *
 * This handler encapsulates functionality used to manage time of day.
 *
 * @{
 */

/**
 *  @brief TOD control.
 */
typedef struct {
  /**
   *  @brief Indicates if the time of day is set.
   *
   *  This is true if the application has set the current
   *  time of day, and false otherwise.
   */
  bool is_set;
} TOD_Control;

/**
 * @brief TOD Management information
 */
extern TOD_Control _TOD;

/**
 * @brief This array contains the number of days in all months up to the month
 *   indicated by the index of the second dimension.
 *
 * The first dimension should be 0 for leap years, and 1 otherwise.
 */
extern const uint16_t _TOD_Days_to_date[ 2 ][ 13 ];

/**
 * @brief Locks the time of day mutex.
 */
void _TOD_Lock( void );

/**
 * @brief Unlocks the time of day mutex.
 */
void _TOD_Unlock( void );

/**
 * @brief Checks if api mutex is owner of the time of day mutex.
 *
 * @retval true It is owner of the time of day mutex.
 * @retval false It is not owner of the time of day mutex.
 */
#if defined(RTEMS_DEBUG)
bool _TOD_Is_owner( void );
#endif

/**
 * @brief Acquires the lock context for the timecounter.
 *
 * @param lock_context The lock to acquire.
 */
static inline void _TOD_Acquire( ISR_lock_Context *lock_context )
{
  _Timecounter_Acquire( lock_context );
}

/**
 * @brief Releases the lock context for the timecounter.
 *
 * @param lock_context The lock to release.
 */
static inline void _TOD_Release( ISR_lock_Context *lock_context )
{
  _Timecounter_Release( lock_context );
}

/**
 * @brief Maps the year to the leap year index.
 *
 * @param year is the year to map.
 *
 * @retval 0 The year is a leap year.
 *
 * @retval 1 The year is not a leap year.
 */
static inline size_t _TOD_Get_leap_year_index( uint32_t year )
{
  _Assert( year % 4 != 0 || year % 100 != 0 || year % 400 == 0 );
  return ( ( year % 4 ) + 3 ) / 4;
}

/**
 * @brief Checks the time point is a valid new time of day for _TOD_Set().
 *
 * @param tod the time of day to check.
 *
 * @retval STATUS_SUCCESSFUL The time of day is valid.
 *
 * @retval STATUS_INVALID_NUMBER The time of day is invalid.
 */
Status_Control _TOD_Is_valid_new_time_of_day( const struct timespec *tod );

/**
 * @brief Sets the time of day.
 *
 * The caller must be the owner of the TOD lock.
 *
 * @param tod The new time of day in timespec format representing
 *   the time since UNIX Epoch.  The new time of day shall be valid according
 *   to _TOD_Is_valid_new_time_of_day().
 * @param lock_context The ISR lock context used for the corresponding
 *   _TOD_Acquire().  The caller must be the owner of the TOD lock.  This
 *   function will release the TOD lock.
 *
 * @retval STATUS_SUCCESSFUL Successful operation.
 * @retval other Some error occurred.
 */
Status_Control _TOD_Set(
  const struct timespec *tod,
  ISR_lock_Context      *lock_context
);

/**
 * @brief Gets the current time in the timespec format.
 *
 * @param[out] time The value gathered by the request.
 */
static inline void _TOD_Get(
  struct timespec *tod
)
{
  _Timecounter_Nanotime( tod );
}

/**
 * @brief Gets the system uptime with potential accuracy to the nanosecond.
 *
 * This routine returns the system uptime with potential accuracy
 * to the nanosecond.
 *
 * The initial uptime value is undefined.
 *
 * @param[out] time Is a pointer to the uptime after the method call.
 */
static inline void _TOD_Get_uptime(
  Timestamp_Control *time
)
{
  *time = _Timecounter_Sbinuptime();
}

/**
 * @brief Gets the system uptime with potential accuracy to the nanosecond.
 *
 * The initial uptime value is zero.
 *
 * @param[out] time Is a pointer to the uptime after the method call.
 */
static inline void _TOD_Get_zero_based_uptime(
  Timestamp_Control *time
)
{
  *time = _Timecounter_Sbinuptime() - SBT_1S;
}

/**
 * @brief Gets the system uptime with potential accuracy to the nanosecond.
 *
 * The initial uptime value is zero.
 *
 * @param[out] time Is a pointer to the uptime after the method call.
 */
static inline void _TOD_Get_zero_based_uptime_as_timespec(
  struct timespec *time
)
{
  _Timecounter_Nanouptime( time );
  --time->tv_sec;
}

/**
 * @brief Returns Number of seconds Since RTEMS epoch.
 *
 * The following contains the number of seconds from 00:00:00
 * January 1, TOD_BASE_YEAR until the current time of day.
 *
 * @return The number of seconds since RTEMS epoch.
 */
static inline uint32_t _TOD_Seconds_since_epoch( void )
{
  return (uint32_t) _Timecounter_Time_second;
}

/**
 *  @brief Gets number of ticks in a second.
 */
#define TOD_TICKS_PER_SECOND _Watchdog_Ticks_per_second

/**
 * @brief This routine returns a timeval based upon the internal timespec
 *      format TOD.
 *
 * @param[out] time The timeval to be filled in by the method.
 */
static inline void _TOD_Get_timeval(
  struct timeval *time
)
{
  _Timecounter_Microtime( time );
}

/**
 * @brief Check if the TOD is Set
 *
 * @retval true The time is set.
 * @retval false The time is not set.
 */
static inline bool _TOD_Is_set( void )
{
  return _TOD.is_set;
}

/** @} */

/**
 * @defgroup RTEMSScoreTODHooks Time of Day Handler Action Hooks
 *
 * @ingroup RTEMSScoreTOD
 *
 * @brief This group contains the implementation to support Time of Day Handler
 *   action hooks.
 *
 * The following support registering a hook which is invoked
 * when the TOD is set. These can be used by a paravirtualized
 * BSP to mirror time changes to the hosting environment or a
 * regular BSP to program a real-time clock when the RTEMS TOD
 * is set.
 *
 * @{
 */

/**
 *  @brief Possible actions where a registered hook could be invoked
 */
typedef enum {
  /**
   *  @brief Constant to indicate the TOD is being set.
   */
  TOD_ACTION_SET_CLOCK
} TOD_Action;

/**
 * @brief Structure to manage each TOD action hook
 */
typedef struct TOD_Hook {
  /** This is the chain node portion of an object. */
  Chain_Node Node;

  /** This is the TOD action hook that is invoked. */
  Status_Control ( *handler )( TOD_Action, const struct timespec * );
} TOD_Hook;

/**
 * @brief Set of registered methods for TOD Actions
 */
extern Chain_Control _TOD_Hooks;

/**
 * @brief Add a TOD Action Hook
 *
 * This method is used to add a hook to the TOD action set.
 *
 * @brief hook is the action hook to register.
 */
void _TOD_Hook_Register(
  TOD_Hook *hook
);

/**
 * @brief Remove a TOD Action Hook
 *
 * This method is used to remove a hook from the TOD action set.
 *
 * @brief hook is the action hook to unregister.
 */
void _TOD_Hook_Unregister(
  TOD_Hook *hook
);

/**
 * @brief Run the TOD Action Hooks
 *
 * This method is used to invoke the set of TOD action hooks.
 *
 * @brief action The action which triggered this run.
 * @brief tod The current time of day.
 *
 * @retval STATUS_SUCCESSFUL Successful operation.
 * @retval other Some error occurred.
 */
Status_Control _TOD_Hook_Run(
  TOD_Action             action,
  const struct timespec *tod
);


/** @} */

#ifdef __cplusplus
}
#endif

#endif
/* end of include file */