hal_icu.h

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/*
    ChibiOS - Copyright (C) 2006..2018 Giovanni Di Sirio

    Licensed 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.
*/

/**
 * @file    hal_icu.h
 * @brief   ICU Driver macros and structures.
 *
 * @addtogroup ICU
 * @{
 */

#ifndef HAL_ICU_H
#define HAL_ICU_H

#if (HAL_USE_ICU == TRUE) || defined(__DOXYGEN__)

/*===========================================================================*/
/* Driver constants.                                                         */
/*===========================================================================*/

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

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

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

/**
 * @brief   Driver state machine possible states.
 */
typedef enum {
  ICU_UNINIT = 0,                   /**< Not initialized.                   */
  ICU_STOP = 1,                     /**< Stopped.                           */
  ICU_READY = 2,                    /**< Ready.                             */
  ICU_WAITING = 3,                  /**< Waiting for first front.           */
  ICU_ACTIVE = 4                    /**< First front detected.              */
} icustate_t;

/**
 * @brief   Type of a structure representing an ICU driver.
 */
typedef struct ICUDriver ICUDriver;

/**
 * @brief   ICU notification callback type.
 *
 * @param[in] icup      pointer to a @p ICUDriver object
 */
typedef void (*icucallback_t)(ICUDriver *icup);

#include "hal_icu_lld.h"

/*===========================================================================*/
/* Driver macros.                                                            */
/*===========================================================================*/

/**
 * @name    Macro Functions
 * @{
 */
/**
 * @brief   Starts the input capture.
 *
 * @param[in] icup      pointer to the @p ICUDriver object
 *
 * @iclass
 */
#define icuStartCaptureI(icup) do {                                         \
  icu_lld_start_capture(icup);                                              \
  (icup)->state = ICU_WAITING;                                              \
} while (false)

/**
 * @brief   Stops the input capture.
 *
 * @param[in] icup      pointer to the @p ICUDriver object
 *
 * @iclass
 */
#define icuStopCaptureI(icup) do {                                          \
  icu_lld_stop_capture(icup);                                               \
  (icup)->state = ICU_READY;                                                \
} while (false)

/**
 * @brief   Enables notifications.
 * @pre     The ICU unit must have been activated using @p icuStart() and the
 *          capture started using @p icuStartCapture().
 * @note    If the notification is already enabled then the call has no effect.
 *
 * @param[in] icup      pointer to the @p ICUDriver object
 *
 * @iclass
 */
#define icuEnableNotificationsI(icup) icu_lld_enable_notifications(icup)

/**
 * @brief   Disables notifications.
 * @pre     The ICU unit must have been activated using @p icuStart() and the
 *          capture started using @p icuStartCapture().
 * @note    If the notification is already disabled then the call has no effect.
 *
 * @param[in] icup      pointer to the @p ICUDriver object
 *
 * @iclass
 */
#define icuDisableNotificationsI(icup) icu_lld_disable_notifications(icup)

/**
 * @brief   Check on notifications status.
 *
 * @param[in] icup      pointer to the @p ICUDriver object
 * @return              The notifications status.
 * @retval false        if notifications are not enabled.
 * @retval true         if notifications are enabled.
 *
 * @notapi
 */
#define icuAreNotificationsEnabledX(icup)                                   \
  icu_lld_are_notifications_enabled(icup)

/**
 * @brief   Returns the width of the latest pulse.
 * @details The pulse width is defined as number of ticks between the start
 *          edge and the stop edge.
 * @note    This function is meant to be invoked from the width capture
 *          callback.
 *
 * @param[in] icup      pointer to the @p ICUDriver object
 * @return              The number of ticks.
 *
 * @xclass
 */
#define icuGetWidthX(icup) icu_lld_get_width(icup)

/**
 * @brief   Returns the width of the latest cycle.
 * @details The cycle width is defined as number of ticks between a start
 *          edge and the next start edge.
 * @note    This function is meant to be invoked from the width capture
 *          callback.
 *
 * @param[in] icup      pointer to the @p ICUDriver object
 * @return              The number of ticks.
 *
 * @xclass
 */
#define icuGetPeriodX(icup) icu_lld_get_period(icup)
/** @} */

/**
 * @name    Low level driver helper macros
 * @{
 */
/**
 * @brief   Common ISR code, ICU width event.
 *
 * @param[in] icup      pointer to the @p ICUDriver object
 *
 * @notapi
 */
#define _icu_isr_invoke_width_cb(icup) do {                                 \
  if (((icup)->state == ICU_ACTIVE) &&                                      \
      ((icup)->config->width_cb != NULL))                                   \
    (icup)->config->width_cb(icup);                                         \
} while (0)

/**
 * @brief   Common ISR code, ICU period event.
 * @note    A period event brings the driver into the @p ICU_ACTIVE state.
 *
 * @param[in] icup      pointer to the @p ICUDriver object
 *
 * @notapi
 */
#define _icu_isr_invoke_period_cb(icup) do {                                \
  if (((icup)->state == ICU_ACTIVE) &&                                      \
      ((icup)->config->period_cb != NULL))                                  \
    (icup)->config->period_cb(icup);                                        \
  (icup)->state = ICU_ACTIVE;                                               \
} while (0)

/**
 * @brief   Common ISR code, ICU timer overflow event.
 * @note    An overflow always brings the driver back to the @p ICU_WAITING
 *          state.
 *
 * @param[in] icup      pointer to the @p ICUDriver object
 *
 * @notapi
 */
#define _icu_isr_invoke_overflow_cb(icup) do {                              \
  (icup)->config->overflow_cb(icup);                                        \
  (icup)->state = ICU_WAITING;                                              \
} while (0)
/** @} */

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

#ifdef __cplusplus
extern "C" {
#endif
  void icuInit(void);
  void icuObjectInit(ICUDriver *icup);
  void icuStart(ICUDriver *icup, const ICUConfig *config);
  void icuStop(ICUDriver *icup);
  void icuStartCapture(ICUDriver *icup);
  bool icuWaitCapture(ICUDriver *icup);
  void icuStopCapture(ICUDriver *icup);
  void icuEnableNotifications(ICUDriver *icup);
  void icuDisableNotifications(ICUDriver *icup);
#ifdef __cplusplus
}
#endif

#endif /* HAL_USE_ICU == TRUE */

#endif /* HAL_ICU_H */

/** @} */