text: /****************************************************************************
   * arch/mips/src/pic32mz/chip/pic32mz_freerun.h
   *
   *   Copyright (C) 2019 Abdelatif Guettouche. All rights reserved.
   *   Author: Abdelatif Guettouche <abdelatif.guettouche@gmail.com>
   *
   * This file is a part of NuttX:
   *
   *   Copyright (C) 2019 Gregory Nutt. All rights reserved.
   *
   * 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.
   * 3. Neither the name NuttX nor the names of its contributors may be
   *    used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * 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 __ARCH_MIPS_SRC_PIC32MZ_PIC32MZ_FREERUN_H
  #define __ARCH_MIPS_SRC_PIC32MZ_PIC32MZ_FREERUN_H
  
  /****************************************************************************
   * Included Files
   ****************************************************************************/
  
  #include <nuttx/config.h>
  
  #include <stdint.h>
  #include <time.h>
  #include <debug.h>
  
  #include "pic32mz_timer.h"
  
  #ifdef CONFIG_PIC32MZ_FREERUN
  
  /****************************************************************************
   * Public Types
   ****************************************************************************/
  
  /* The freerun client must allocate an instance of this structure and call
   * pic32mz_freerun_initialize() before using the freerun facilities.
   * The client should not access the contents of this structure directly
   * since the contents are subject to change.
   */
  
  struct pic32mz_freerun_s
  {
    uint8_t chan;                            /* The timer in use            */
    uint8_t width;                           /* Width of timer (16- or 32)  */
    bool running;                            /* True: the timer is running  */
    FAR struct pic32mz_timer_dev_s *timer;   /* PIC32MZ timer driver        */
    uint32_t freq;                           /* Timer's frequency (Hz)      */
  
  #ifndef CONFIG_CLOCK_TIMEKEEPING
    uint32_t overflow;                       /* Timer's counter overflow    */
  #endif
  
  #ifdef CONFIG_CLOCK_TIMEKEEPING
    uint64_t counter_mask;                   /* Timer's count register mask */
  #endif
  };
  
  /****************************************************************************
   * Public Data
   ****************************************************************************/
  
  #undef EXTERN
  #if defined(__cplusplus)
  #define EXTERN extern "C"
  extern "C"
  {
  #else
  #define EXTERN extern
  #endif
  
  /****************************************************************************
   * Public Function Prototypes
   ****************************************************************************/
  
  /****************************************************************************
   * Name: pic32mz_freerun_initialize
   *
   * Description:
   *   Initialize the freerun timer wrapper
   *
   * Input Parameters:
   *   freerun    Caller allocated instance of the freerun state structure
   *   chan       Timer channel to be used.
   *   resolution The required resolution of the timer in units of
   *              microseconds. NOTE that the range is restricted to the
   *              range of uint16_t (excluding zero).
   *
   * Returned Value:
   *   Zero (OK) is returned on success; a negated errno value is returned
   *   on failure.
   *
   ****************************************************************************/
  
  int pic32mz_freerun_initialize(struct pic32mz_freerun_s *freerun, int chan,
                                 uint16_t resolution);
  
  /****************************************************************************
   * Name: pic32mz_freerun_counter
   *
   * Description:
   *   Read the counter register of the free-running timer.
   *
   * Input Parameters:
   *   freerun Caller allocated instance of the freerun state structure.  This
   *           structure must have been previously initialized via a call to
   *           pic32mz_freerun_initialize();
   *   ts      The location in which to return the time remaining on the
   *           oneshot timer.
   *
   * Returned Value:
   *   Zero (OK) is returned on success; a negated errno value is returned
   *   on failure.
   *
   ****************************************************************************/
  
  #ifndef CONFIG_CLOCK_TIMEKEEPING
  
  int pic32mz_freerun_counter(struct pic32mz_freerun_s *freerun,
                              struct timespec *ts);
  
  #else /* CONFIG_CLOCK_TIMEKEEPING */
  
  int pic32mz_freerun_counter(struct pic32mz_freerun_s *freerun,
                              uint64_t *counter);
  
  #endif /* CONFIG_CLOCK_TIMEKEEPING */
  
  /****************************************************************************
   * Name: pic32mz_freerun_uninitialize
   *
   * Description:
   *   Stop the free-running timer and release all resources that it uses.
   *
   * Input Parameters:
   *   freerun Caller allocated instance of the freerun state structure.  This
   *           structure must have been previously initialized via a call to
   *           pic32mz_freerun_initialize();
   *
   * Returned Value:
   *   Zero (OK) is returned on success; a negated errno value is returned
   *   on failure.
   *
   ****************************************************************************/
  
  int pic32mz_freerun_uninitialize(struct pic32mz_freerun_s *freerun);
  
  #undef EXTERN
  #ifdef __cplusplus
  }
  #endif
  
  #endif /* CONFIG_PIC32MZ_FREERUN */
  #endif /* __ARCH_MIPS_SRC_PIC32MZ_PIC32MZ_FREERUN_H */
  