/*!
 * \file      adc-board.c
 *
 * \brief     Target board ADC driver implementation
 *
 * \copyright Revised BSD License, see section \ref LICENSE.
 *
 * \code
 *                ______                              _
 *               / _____)             _              | |
 *              ( (____  _____ ____ _| |_ _____  ____| |__
 *               \____ \| ___ |    (_   _) ___ |/ ___)  _ \
 *               _____) ) ____| | | || |_| ____( (___| | | |
 *              (______/|_____)_|_|_| \__)_____)\____)_| |_|
 *              (C)2013-2017 Semtech
 *
 * \endcode
 *
 * \author    Miguel Luis ( Semtech )
 *
 * \author    Gregory Cristian ( Semtech )
 */
#include <stdint.h>
#include <stdbool.h>
#include "stm32l0xx.h"
#include "board-config.h"
#include "adc-board.h"

ADC_HandleTypeDef AdcHandle;

void AdcMcuInit( Adc_t *obj, PinNames adcInput )
{
    AdcHandle.Instance = ( ADC_TypeDef* )ADC1_BASE;

    __HAL_RCC_ADC1_CLK_ENABLE( );

    HAL_ADC_DeInit( &AdcHandle );

    if( adcInput != NC )
    {
        GpioInit( &obj->AdcInput, adcInput, PIN_ANALOGIC, PIN_PUSH_PULL, PIN_NO_PULL, 0 );
    }
}

void AdcMcuConfig( void )
{
    // Configure ADC
    AdcHandle.Init.OversamplingMode      = DISABLE;
    AdcHandle.Init.ClockPrescaler        = ADC_CLOCK_SYNC_PCLK_DIV2;
    AdcHandle.Init.Resolution            = ADC_RESOLUTION_12B;
    AdcHandle.Init.SamplingTime          = ADC_SAMPLETIME_160CYCLES_5;
    AdcHandle.Init.ScanConvMode          = ADC_SCAN_DIRECTION_FORWARD;
    AdcHandle.Init.DataAlign             = ADC_DATAALIGN_RIGHT;
    AdcHandle.Init.ContinuousConvMode    = DISABLE;
    AdcHandle.Init.DiscontinuousConvMode = DISABLE;
    AdcHandle.Init.ExternalTrigConvEdge  = ADC_EXTERNALTRIGCONVEDGE_NONE;
    AdcHandle.Init.ExternalTrigConv      = ADC_SOFTWARE_START;
    AdcHandle.Init.DMAContinuousRequests = DISABLE;
    AdcHandle.Init.EOCSelection          = ADC_EOC_SINGLE_CONV;
    AdcHandle.Init.Overrun               = ADC_OVR_DATA_PRESERVED;
    AdcHandle.Init.LowPowerAutoWait      = DISABLE;
    AdcHandle.Init.LowPowerFrequencyMode = ENABLE; // To be enabled only if ADC clock < 2.8 MHz
    AdcHandle.Init.LowPowerAutoPowerOff  = DISABLE;
    HAL_ADC_Init( &AdcHandle );

    // Calibration
    HAL_ADCEx_Calibration_Start( &AdcHandle, ADC_SINGLE_ENDED );

}

uint16_t AdcMcuReadChannel( Adc_t *obj, uint32_t channel )
{
    ADC_ChannelConfTypeDef adcConf = { 0 };
    uint16_t adcData = 0;
    uint32_t tickStart = 0;
    bool isAdcReady = true;

    // Enable HSI
    __HAL_RCC_HSI_ENABLE( );

    // Wait till HSI is ready
    while( __HAL_RCC_GET_FLAG( RCC_FLAG_HSIRDY ) == RESET )
    {
    }

    __HAL_RCC_ADC1_CLK_ENABLE( );

    // Deselects all channels
    adcConf.Channel = ADC_CHANNEL_MASK;
    adcConf.Rank = ADC_RANK_NONE; 
    HAL_ADC_ConfigChannel( &AdcHandle, &adcConf );

    adcConf.Channel = channel;
    adcConf.Rank = ADC_RANK_CHANNEL_NUMBER;
    HAL_ADC_ConfigChannel( &AdcHandle, &adcConf );

    // Enable ADC1
    __HAL_ADC_ENABLE( &AdcHandle );

    // Wait for ADC to effectively be enabled
    tickStart = HAL_GetTick( );
    while( __HAL_ADC_GET_FLAG( &AdcHandle, ADC_FLAG_RDY ) == RESET )
    {
        if( ( HAL_GetTick( ) - tickStart ) > ADC_ENABLE_TIMEOUT )
        {
            isAdcReady = false;
            break;
        }
    }

    if( isAdcReady != false )
    {
        // Start ADC Software Conversion
        HAL_ADC_Start( &AdcHandle );

        HAL_ADC_PollForConversion( &AdcHandle, HAL_MAX_DELAY );

        adcData = HAL_ADC_GetValue( &AdcHandle );
    }

    __HAL_ADC_DISABLE( &AdcHandle );

    if( ( adcConf.Channel == ADC_CHANNEL_TEMPSENSOR ) || ( adcConf.Channel == ADC_CHANNEL_VREFINT ) )
    {
        HAL_ADC_DeInit( &AdcHandle );
    }
    __HAL_RCC_ADC1_CLK_DISABLE( );

    // Disable HSI
    __HAL_RCC_HSI_DISABLE( );

    return adcData;
}