text: /****************************************************************************
   * arch/arm/src/stm32/stm32_freerun.h
   *
   * 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.
   *
   ****************************************************************************/
  
  #ifndef __ARCH_ARM_SRC_STM32_FREERUN_H
  #define __ARCH_ARM_SRC_STM32_FREERUN_H
  
  /****************************************************************************
   * Included Files
   ****************************************************************************/
  
  #include <nuttx/config.h>
  
  #include <stdint.h>
  #include <time.h>
  #include <debug.h>
  
  #include "stm32_tim.h"
  
  #ifdef CONFIG_STM32_FREERUN
  
  /****************************************************************************
   * Public Types
   ****************************************************************************/
  
  /* The freerun client must allocate an instance of this structure and called
   * stm32_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 stm32_freerun_s
  {
    uint8_t chan;                    /* The timer/counter in use */
    uint8_t width;                   /* Width of timer (16- or 32-bits) */
    FAR struct stm32_tim_dev_s *tch; /* Handle returned by stm32_tim_init() */
    uint32_t frequency;
  
  #ifndef CONFIG_CLOCK_TIMEKEEPING
    uint32_t overflow;               /* Timer counter overflow */
  #endif
  
  #ifdef CONFIG_CLOCK_TIMEKEEPING
    uint64_t counter_mask;
  #endif
  };
  
  /****************************************************************************
   * Public Data
   ****************************************************************************/
  
  #undef EXTERN
  #if defined(__cplusplus)
  #define EXTERN extern "C"
  extern "C"
  {
  #else
  #define EXTERN extern
  #endif
  
  /****************************************************************************
   * Public Function Prototypes
   ****************************************************************************/
  
  /****************************************************************************
   * Name: stm32_freerun_initialize
   *
   * Description:
   *   Initialize the freerun timer wrapper
   *
   * Input Parameters:
   *   freerun    Caller allocated instance of the freerun state structure
   *   chan       Timer counter 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 stm32_freerun_initialize(struct stm32_freerun_s *freerun, int chan,
                               uint16_t resolution);
  
  /****************************************************************************
   * Name: stm32_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
   *           stm32_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 stm32_freerun_counter(struct stm32_freerun_s *freerun,
                            struct timespec *ts);
  
  #else /* CONFIG_CLOCK_TIMEKEEPING */
  
  int stm32_freerun_counter(struct stm32_freerun_s *freerun,
                            uint64_t *counter);
  
  #endif /* CONFIG_CLOCK_TIMEKEEPING */
  
  /****************************************************************************
   * Name: stm32_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
   *           stm32_freerun_initialize();
   *
   * Returned Value:
   *   Zero (OK) is returned on success; a negated errno value is returned
   *   on failure.
   *
   ****************************************************************************/
  
  int stm32_freerun_uninitialize(struct stm32_freerun_s *freerun);
  
  #undef EXTERN
  #ifdef __cplusplus
  }
  #endif
  
  #endif /* CONFIG_STM32_FREERUN */
  #endif /* __ARCH_ARM_SRC_STM32_FREERUN_H */
  