/*
    ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
                 2011,2012,2013 Giovanni Di Sirio.

    This file is part of ChibiOS/RT.

    ChibiOS/RT 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/RT 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/>.
*/

/**
 * @file    chrt.h
 * @brief   Real Time Counter and Measurement module macros and structures.
 *
 * @addtogroup realtime_counter
 * @{
 */

#ifndef _CHRT_H_
#define _CHRT_H_

#if CH_CFG_USE_RT || defined(__DOXYGEN__)

#define port_rt_get_counter_value() 0

/*===========================================================================*/
/* Module constants.                                                         */
/*===========================================================================*/

/*===========================================================================*/
/* Module pre-compile time settings.                                         */
/*===========================================================================*/

/*===========================================================================*/
/* Derived constants and error checks.                                       */
/*===========================================================================*/

/*===========================================================================*/
/* Module data structures and types.                                         */
/*===========================================================================*/

/**
 * @brief   Type of a Time Measurement object.
 * @note    The maximum measurable time period depends on the implementation
 *          of the realtime counter and its clock frequency.
 * @note    The measurement is not 100% cycle-accurate, it can be in excess
 *          of few cycles depending on the compiler and target architecture.
 * @note    Interrupts can affect measurement if the measurement is performed
 *          with interrupts enabled.
 */
typedef struct {
  rtcnt_t               best;           /**< @brief Best measurement.       */
  rtcnt_t               worst;          /**< @brief Worst measurement.      */
  rtcnt_t               cumulative;     /**< @brief Cumulative measurement. */
  rtcnt_t               last;           /**< @brief Last measurement.       */
} time_measurement_t;

/*===========================================================================*/
/* Module macros.                                                            */
/*===========================================================================*/

/**
 * @name    Time conversion utilities for the realtime counter
 * @{
 */
/**
 * @brief   Seconds to realtime counter.
 * @details Converts from seconds to realtime counter cycles.
 * @note    The result is rounded upward to the next tick boundary.
 *
 * @param[in] sec       number of seconds
 * @return              The number of cycles.
 *
 * @api
 */
#define S2RTV(freq, sec) ((freq) * (sec))

/**
 * @brief   Milliseconds to realtime counter.
 * @details Converts from milliseconds to realtime counter cycles.
 * @note    The result is rounded upward to the next tick boundary.
 *
 * @param[in] msec      number of milliseconds
 * @return              The number of cycles.
 *
 * @api
 */
#define MS2RTC(freq, msec) (rtcnt_t)((((freq) + 999UL) / 1000UL) * (msec))

/**
 * @brief   Microseconds to realtime counter.
 * @details Converts from microseconds to realtime counter cycles.
 * @note    The result is rounded upward to the next tick boundary.
 *
 * @param[in] usec      number of microseconds
 * @return              The number of cycles.
 *
 * @api
 */
#define US2RTC(freq, usec) (rtcnt_t)((((freq) + 999999UL) / 1000000UL) * (usec))

/**
 * @brief   Realtime counter cycles to seconds.
 * @details Converts from realtime counter cycles number to seconds.
 *
 * @param[in] n         number of cycles
 * @return              The number of seconds.
 *
 * @api
 */
#define RTC2S(freq, n) (rtcnt_t)((n) / (freq))

/**
 * @brief   Realtime counter cycles to milliseconds.
 * @details Converts from realtime counter cycles number to milliseconds.
 *
 * @param[in] n         number of cycles
 * @return              The number of milliseconds.
 *
 * @api
 */
#define RTC2MS(freq, n) ((n) / ((freq) / 1000UL))

/**
 * @brief   Realtime counter cycles to microseconds.
 * @details Converts from realtime counter cycles number to microseconds.
 *
 * @param[in] n         number of cycles
 * @return              The number of microseconds.
 *
 * @api
 */
#define RTC2US(freq, n) ((n) / ((freq) / 1000000UL))
/** @} */

/*===========================================================================*/
/* External declarations.                                                    */
/*===========================================================================*/

#ifdef __cplusplus
extern "C" {
#endif
  void _rt_init(void);
  bool chRTIsCounterWithin(rtcnt_t start, rtcnt_t end);
  void chRTPolledDelay(rtcnt_t cycles);
  void chRTTimeMeasurementObjectInit(time_measurement_t *tmp);
  NOINLINE void chRTTimeMeasurementStartX(time_measurement_t *tmp);
  NOINLINE void chRTTimeMeasurementStopX(time_measurement_t *tmp);
#ifdef __cplusplus
}
#endif

/*===========================================================================*/
/* Module inline functions.                                                  */
/*===========================================================================*/

#endif /* CH_CFG_USE_RT */

#endif /* _CHRT_H_ */

/** @} */