/***************************************************************************//**
 * @file
 * @brief Voltage Comparator (VCMP) peripheral API for EFM32
 * @author Energy Micro AS
 * @version 2.3.2
 *******************************************************************************
 * @section License
 * <b>(C) Copyright 2010 Energy Micro AS, http://www.energymicro.com</b>
 *******************************************************************************
 *
 * This source code is the property of Energy Micro AS. The source and compiled
 * code may only be used on Energy Micro "EFM32" microcontrollers.
 *
 * This copyright notice may not be removed from the source code nor changed.
 *
 * DISCLAIMER OF WARRANTY/LIMITATION OF REMEDIES: Energy Micro AS has no
 * obligation to support this Software. Energy Micro AS is providing the
 * Software "AS IS", with no express or implied warranties of any kind,
 * including, but not limited to, any implied warranties of merchantability
 * or fitness for any particular purpose or warranties against infringement
 * of any proprietary rights of a third party.
 *
 * Energy Micro AS will not be liable for any consequential, incidental, or
 * special damages, or any other relief, or for any claim by any third party,
 * arising from your use of this Software.
 *
 ******************************************************************************/
#ifndef __EFM32_VCMP_H
#define __EFM32_VCMP_H
#include "efm32.h"

#include <stdint.h>
#include <stdbool.h>

#ifdef __cplusplus
extern "C" {
#endif

/***************************************************************************//**
 * @addtogroup EFM32_Library
 * @{
 ******************************************************************************/

/***************************************************************************//**
 * @addtogroup VCMP
 * @{
 ******************************************************************************/

/*******************************************************************************
 ********************************   ENUMS   ************************************
 ******************************************************************************/

/** Warm-up Time in High Frequency Peripheral Clock cycles */
typedef enum
{
  /** 4 cycles */
  vcmpWarmTime4Cycles   = _VCMP_CTRL_WARMTIME_4CYCLES,
  /** 8 cycles */
  vcmpWarmTime8Cycles   = _VCMP_CTRL_WARMTIME_8CYCLES,
  /** 16 cycles */
  vcmpWarmTime16Cycles  = _VCMP_CTRL_WARMTIME_16CYCLES,
  /** 32 cycles */
  vcmpWarmTime32Cycles  = _VCMP_CTRL_WARMTIME_32CYCLES,
  /** 64 cycles */
  vcmpWarmTime64Cycles  = _VCMP_CTRL_WARMTIME_64CYCLES,
  /** 128 cycles */
  vcmpWarmTime128Cycles = _VCMP_CTRL_WARMTIME_128CYCLES,
  /** 256 cycles */
  vcmpWarmTime256Cycles = _VCMP_CTRL_WARMTIME_256CYCLES,
  /** 512 cycles */
  vcmpWarmTime512Cycles = _VCMP_CTRL_WARMTIME_512CYCLES
} VCMP_WarmTime_TypeDef;

/** Hyseresis configuration */
typedef enum
{
  /** Normal operation, no hysteresis */
  vcmpHystNone,
  /** Digital output will not toggle until positive edge is at least
   *  20mV above or below negative input voltage */
  vcmpHyst20mV
} VCMP_Hysteresis_TypeDef;

/*******************************************************************************
 *******************************   STRUCTS   ***********************************
 ******************************************************************************/

/** VCMP Initialization structure */
typedef struct
{
  /** If set to true, will reduce by half the bias current */
  bool                    halfBias;
  /** BIAS current configuration, depends on halfBias setting,
   *  above, see reference manual */
  int                     biasProg;
  /** Enable interrupt for falling edge */
  bool                    irqFalling;
  /** Enable interrupt for rising edge */
  bool                    irqRising;
  /** Warm-up time in clock cycles */
  VCMP_WarmTime_TypeDef   warmup;
  /** Hysteresis configuration */
  VCMP_Hysteresis_TypeDef hyst;
  /** Output value when comparator is inactive, should be 0 or 1 */
  int                     inactive;
  /** Enable low power mode for VDD and bandgap reference */
  bool                    lowPowerRef;
  /** Trigger level, according to formula
   *  VDD Trigger Level = 1.667V + 0.034V x triggerLevel */
  int                     triggerLevel;
  /** Enable VCMP after configuration */
  bool                    enable;
} VCMP_Init_TypeDef;

/** Default VCMP initialization structure */
#define VCMP_INIT_DEFAULT                                                  \
  { true,                /** Half Bias enabled */                          \
    0x7,                 /** Bias curernt 0.7 uA when half bias enabled */ \
    false,               /** Falling edge sense not enabled */             \
    false,               /** Rising edge sense not enabled */              \
    vcmpWarmTime4Cycles, /** 4 clock cycles warm-up time */                \
    vcmpHystNone,        /** No hysteresis */                              \
    0,                   /** 0 in digital ouput when inactive */           \
    true,                /** Do not use low power reference */             \
    39,                  /** Trigger level just below 3V */                \
    true,                /** Enable after init */                          \
  }

/*******************************************************************************
 *****************************   PROTOTYPES   **********************************
 ******************************************************************************/
void VCMP_Init(const VCMP_Init_TypeDef *vcmpInit);
void VCMP_LowPowerRefSet(bool enable);
void VCMP_TriggerSet(int level);

static __INLINE void VCMP_Enable(void);
static __INLINE void VCMP_Disable(void);
static __INLINE uint32_t VCMP_VoltageToLevel(float v);
static __INLINE bool VCMP_VDDLower(void);
static __INLINE bool VCMP_VDDHigher(void);
static __INLINE bool VCMP_Ready(void);
static __INLINE void VCMP_IntClear(uint32_t flags);
static __INLINE void VCMP_IntSet(uint32_t flags);
static __INLINE void VCMP_IntDisable(uint32_t flags);
static __INLINE void VCMP_IntEnable(uint32_t flags);
static __INLINE uint32_t VCMP_IntGet(void);
static __INLINE uint32_t VCMP_IntGetEnabled(void);

/***************************************************************************//**
 * @brief
 *   Enable Voltage Comparator
 ******************************************************************************/
static __INLINE void VCMP_Enable(void)
{
  VCMP->CTRL |= VCMP_CTRL_EN;
}


/***************************************************************************//**
 * @brief
 *   Disable Voltage Comparator
 ******************************************************************************/
static __INLINE void VCMP_Disable(void)
{
  VCMP->CTRL &= ~(VCMP_CTRL_EN);
}


/***************************************************************************//**
 * @brief
 *   Calculate voltage to trigger level
 *
 * @note
 *   You need soft float support for this function to be working
 *
 * @param[in] v
 *   Voltage Level for trigger
 ******************************************************************************/
static __INLINE uint32_t VCMP_VoltageToLevel(float v)
{
  return (uint32_t)((v - (float)1.667) / (float)0.034);
}


/***************************************************************************//**
 * @brief
 *   Returns true, if Voltage Comparator indicated VDD < trigger level, else
 *   false
 ******************************************************************************/
static __INLINE bool VCMP_VDDLower(void)
{
  if (VCMP->STATUS & VCMP_STATUS_VCMPOUT)
  {
    return false;
  }
  else
  {
    return true;
  }
}


/***************************************************************************//**
 * @brief
 *   Returns true, if Voltage Comparator indicated VDD > trigger level, else
 *   false
 ******************************************************************************/
static __INLINE bool VCMP_VDDHigher(void)
{
  if (VCMP->STATUS & VCMP_STATUS_VCMPOUT)
  {
    return true;
  }
  else
  {
    return false;
  }
}


/***************************************************************************//**
 * @brief
 *    VCMP output is ready
 ******************************************************************************/
static __INLINE bool VCMP_Ready(void)
{
  if (VCMP->STATUS & VCMP_STATUS_VCMPACT)
  {
    return true;
  }
  else
  {
    return false;
  }
}


/***************************************************************************//**
 * @brief
 *   Clear one or more pending VCMP interrupts.
 *
 * @param[in] flags
 *   VCMP interrupt sources to clear. Use a set of interrupt flags OR-ed
 *   together to clear multiple interrupt sources for the VCMP module
 *   (VCMP_IFS_nnn).
 ******************************************************************************/
static __INLINE void VCMP_IntClear(uint32_t flags)
{
  VCMP->IFC = flags;
}


/***************************************************************************//**
 * @brief
 *   Set one or more pending VCMP interrupts from SW.
 *
 * @param[in] flags
 *   VCMP interrupt sources to set to pending. Use a set of interrupt flags
 *   OR-ed together to set multiple interrupt sources for the VCMP module
 *   (VCMP_IFS_nnn).
 ******************************************************************************/
static __INLINE void VCMP_IntSet(uint32_t flags)
{
  VCMP->IFS = flags;
}


/***************************************************************************//**
 * @brief
 *   Disable one or more VCMP interrupts
 *
 * @param[in] flags
 *   VCMP interrupt sources to enable. Use a set of interrupt flags OR-ed
 *   together to set multiple interrupt sources for the VCMP module
 *   (VCMP_IFS_nnn).
 ******************************************************************************/
static __INLINE void VCMP_IntDisable(uint32_t flags)
{
  VCMP->IEN &= ~(flags);
}


/***************************************************************************//**
 * @brief
 *   Enable one or more VCMP interrupts
 *
 * @param[in] flags
 *   VCMP interrupt sources to enable. Use a set of interrupt flags OR-ed
 *   together to set multiple interrupt sources for the VCMP module
 *   (VCMP_IFS_nnn).
 ******************************************************************************/
static __INLINE void VCMP_IntEnable(uint32_t flags)
{
  VCMP->IEN |= flags;
}


/***************************************************************************//**
 * @brief
 *   Get pending VCMP interrupt flags
 *
 * @note
 *   The event bits are not cleared by the use of this function
 *
 * @return
 *   Pending VCMP interrupt sources. Returns a set of interrupt flags OR-ed
 *   together for multiple interrupt sources in the VCMP module (VCMP_IFS_nnn).
 ******************************************************************************/
static __INLINE uint32_t VCMP_IntGet(void)
{
  return(VCMP->IF);
}


/***************************************************************************//**
 * @brief
 *   Get enabled and pending VCMP interrupt flags.
 *
 * @details
 *   Useful for handling more interrupt sources in the same interrupt handler.
 *
 * @note
 *   The event bits are not cleared by the use of this function.
 *
 * @return
 *   Pending and enabled VCMP interrupt sources.
 *   The return value is the bitwise AND combination of
 *   - the OR combination of enabled interrupt sources in VCMP_IEN_nnn
 *   register (VCMP_IEN_nnn) and
 *   - the OR combination of valid interrupt flags of the VCMP module
 *   (VCMP_IF_nnn).
 ******************************************************************************/
static __INLINE uint32_t VCMP_IntGetEnabled(void)
{
  uint32_t tmp = 0U;

  /* Store VCMP->IEN in temporary variable in order to define explicit order
   * of volatile accesses. */
  tmp = VCMP->IEN;

  /* Bitwise AND of pending and enabled interrupts */
  return VCMP->IF & tmp;
}

/** @} (end addtogroup VCMP) */
/** @} (end addtogroup EFM32_Library) */

#ifdef __cplusplus
}
#endif

#endif /* __EFM32_VCMP_H */