ChibiOS-Contrib/os/hal/include/eicu.h

/*
    ChibiOS/RT - Copyright (C) 2006-2013 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.
*/
/*
   Rewritten by Emil Fresk (1/5 - 2014) for extended input capture
   functionality. And fix for spurious callbacks in the interrupt handler.
*/

#ifndef _EICU_H_
#define _EICU_H_

#if HAL_USE_EICU || 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 {
  EICU_UNINIT   = 0,          /* Not initialized.                           */
  EICU_STOP     = 1,          /* Stopped.                                   */
  EICU_READY    = 2,          /* Ready.                                     */
  EICU_WAITING  = 3,          /* Waiting for first edge.                    */
  EICU_ACTIVE   = 4,          /* Active cycle phase.                        */
  EICU_IDLE     = 5           /* Idle cycle phase.                          */
} eicustate_t;

/** 
 * @brief EICU channel selection definition
 */
typedef enum {
  EICU_CHANNEL_1 = 0,
  EICU_CHANNEL_2 = 1,
  EICU_CHANNEL_3 = 2,
  EICU_CHANNEL_4 = 3
} eicuchannel_t;

/**
 * @brief   Type of a structure representing an EICU driver.
 */
typedef struct EICUDriver EICUDriver;

/**
 * @brief EICU notification callback type.
 *
 * @param[in] eicup     Pointer to a EICUDriver object
 * @param[in] channel   EICU channel that fired the interrupt
 */
typedef void (*eicucallback_t)(EICUDriver *eicup, eicuchannel_t channel);

#include "eicu_lld.h"

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

/**
 * @name    Macro Functions
 * @{
 */
/**
 * @brief   Enables the extended input capture.
 *
 * @param[in] eicup     Pointer to the @p EICUDriver object
 *
 * @iclass
 */
#define eicuEnableI(eicup) eicu_lld_enable(eicup)

/**
 * @brief   Disables the extended input capture.
 *
 * @param[in] eicup     Pointer to the @p EICUDriver object
 *
 * @iclass
 */
#define eicuDisableI(eicup) eicu_lld_disable(eicup)

/**
 * @brief   Returns the time of the latest measurement.
 * @details The pulse width is defined as number of ticks between the 2
 *          capture events depending on EICU mode (pulse width or period).
 * @note    This function is meant to be invoked from the capture
 *          callback only.
 *
 * @param[in] eicup     Pointer to the @p EICUDriver object
 * @param[in] channel   The timer channel that fired the interrupt.
 * @return              The number of ticks.
 *
 * @special
 */
#define eicuGetTime(eicup, channel) eicu_lld_get_time((eicup), (channel))

/**
 * @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 capture
 *          callback only.
 *
 * @param[in] eicup     Pointer to the @p EICUDriver object
 * @return              The number of ticks.
 *
 * @special
 */
#define eicuGetPeriod(eicup) eicu_lld_get_period(eicup)
/** @} */

/**
 * @name    Low Level driver helper macros
 * @{
 */
/**
 * @brief   Common ISR code, EICU PWM width event.
 *
 * @param[in] eicup     Pointer to the @p EICUDriver object
 * @param[in] channel   The timer channel that fired the interrupt.
 *
 * @notapi
 */
static inline void _eicu_isr_invoke_pwm_width_cb(EICUDriver *eicup,
                                                 eicuchannel_t channel) {
  if (eicup->state != EICU_WAITING) {
    eicup->state = EICU_IDLE;
    eicup->config->iccfgp[channel]->capture_cb(eicup, channel);
  }
}

/**
 * @brief   Common ISR code, EICU PWM period event.
 *
 * @param[in] eicup     Pointer to the @p EICUDriver object
 * @param[in] channel   The timer channel that fired the interrupt.
 *
 * @notapi
 */
static inline void _eicu_isr_invoke_pwm_period_cb(EICUDriver *eicup,
                                                  eicuchannel_t channel) {
  eicustate_t previous_state = eicup->state;
  eicup->state = EICU_ACTIVE;
  if (previous_state != EICU_WAITING)
    eicup->config->period_cb(eicup, channel);
}

/**
 * @brief   Common ISR code, EICU Pulse width event.
 * @details This macro needs special care since it needs to invert the
 *          correct polarity bit to detect pulses.
 * @note    This macro assumes that the polarity is not changed by some
 *          external user. It must only be changed using the HAL.
 * 
 * @param[in] eicup     Pointer to the @p EICUDriver object
 * @param[in] channel   The timer channel that fired the interrupt.
 *
 * @notapi
 */
static inline void _eicu_isr_invoke_pulse_width_cb(EICUDriver *eicup,
                                                   eicuchannel_t channel) {
  if (eicup->state == EICU_ACTIVE) {
    eicup->state = EICU_READY;
    eicu_lld_invert_polarity(eicup, channel);
    eicup->config->iccfgp[channel]->capture_cb(eicup, channel);
  }
  else {
    eicup->state = EICU_ACTIVE;
    eicup->last_count[channel] = eicu_lld_get_compare(eicup, channel);
    eicu_lld_invert_polarity(eicup, channel);
  }
}

/**
 * @brief   Common ISR code, EICU Edge detect event.
 *
 * @param[in] eicup     Pointer to the @p EICUDriver object
 * @param[in] channel   The timer channel that fired the interrupt.
 *
 * @notapi
 */
static inline void _eicu_isr_invoke_edge_detect_cb(EICUDriver *eicup,
                                                   eicuchannel_t channel) {
  eicup->state = EICU_READY;
  eicup->config->iccfgp[channel]->capture_cb(eicup, channel);
  eicup->last_count[channel] = eicu_lld_get_compare(eicup, channel);
}

/**
 * @brief   Common ISR code, EICU timer overflow event.
 *
 * @param[in] eicup      Pointer to the @p EICUDriver object
 *
 * @notapi
 */
#define _eicu_isr_invoke_overflow_cb(icup) {                                   \
  (eicup)->config->overflow_cb(eicup, 0);                                      \
}
/** @} */

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

#ifdef __cplusplus
extern "C" {
#endif
  void eicuInit(void);
  void eicuObjectInit(EICUDriver *eicup);
  void eicuStart(EICUDriver *eicup, const EICUConfig *config);
  void eicuStop(EICUDriver *eicup);
  void eicuEnable(EICUDriver *eicup);
  void eicuDisable(EICUDriver *eicup);
#ifdef __cplusplus
}
#endif

#endif /* HAL_USE_EICU */

#endif /* _EICU_H_ */

/** @} */