File content as of revision 87:085cde657901:

/* mbed Microcontroller Library
 * Copyright (c) 2014, STMicroelectronics
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. Neither the name of STMicroelectronics nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#include "analogin_api.h"
#include "wait_api.h"

#if DEVICE_ANALOGIN

#include "cmsis.h"
#include "pinmap.h"
#include "error.h"
#include "stm32f4xx_hal.h"

static const PinMap PinMap_ADC[] = {
    {PA_0, ADC_1, STM_PIN_DATA(STM_MODE_ANALOG, GPIO_NOPULL, 0)}, // ADC1_IN0
    {PA_1, ADC_1, STM_PIN_DATA(STM_MODE_ANALOG, GPIO_NOPULL, 0)}, // ADC1_IN1
    {PA_4, ADC_1, STM_PIN_DATA(STM_MODE_ANALOG, GPIO_NOPULL, 0)}, // ADC1_IN4
    {PB_0, ADC_1, STM_PIN_DATA(STM_MODE_ANALOG, GPIO_NOPULL, 0)}, // ADC1_IN8
    {PC_1, ADC_1, STM_PIN_DATA(STM_MODE_ANALOG, GPIO_NOPULL, 0)}, // ADC1_IN11
    {PC_0, ADC_1, STM_PIN_DATA(STM_MODE_ANALOG, GPIO_NOPULL, 0)}, // ADC1_IN10
    {NC,   NC,    0}
};

ADC_HandleTypeDef AdcHandle;

int adc_inited = 0;

void analogin_init(analogin_t *obj, PinName pin) {  
    // Get the peripheral name (ADC_1, ADC_2...) from the pin and assign it to the object
    obj->adc = (ADCName)pinmap_peripheral(pin, PinMap_ADC);

    if (obj->adc == (ADCName)NC) {
        error("ADC error: pinout mapping failed.");
    }

    // Configure GPIO
    pinmap_pinout(pin, PinMap_ADC);

    // Save pin number for the read function
    obj->pin = pin;

    // The ADC initialization is done once
    if (adc_inited == 0) {
        adc_inited = 1;
      
        // Enable ADC clock
        __ADC1_CLK_ENABLE();

        // Configure ADC
        AdcHandle.Instance = (ADC_TypeDef *)(obj->adc);
        AdcHandle.Init.ClockPrescaler        = ADC_CLOCKPRESCALER_PCLK_DIV2;
        AdcHandle.Init.Resolution            = ADC_RESOLUTION12b;
        AdcHandle.Init.ScanConvMode          = DISABLE;
        AdcHandle.Init.ContinuousConvMode    = DISABLE;
        AdcHandle.Init.DiscontinuousConvMode = DISABLE;
        AdcHandle.Init.NbrOfDiscConversion   = 0;
        AdcHandle.Init.ExternalTrigConvEdge  = ADC_EXTERNALTRIGCONVEDGE_NONE;
        AdcHandle.Init.ExternalTrigConv      = ADC_EXTERNALTRIGCONV_T1_CC1;
        AdcHandle.Init.DataAlign             = ADC_DATAALIGN_RIGHT;
        AdcHandle.Init.NbrOfConversion       = 1;
        AdcHandle.Init.DMAContinuousRequests = DISABLE;
        AdcHandle.Init.EOCSelection          = DISABLE;      
        HAL_ADC_Init(&AdcHandle);   
    }
}

static inline uint16_t adc_read(analogin_t *obj) {
  ADC_ChannelConfTypeDef sConfig;
  
  AdcHandle.Instance = (ADC_TypeDef *)(obj->adc);

  // Configure ADC channel
  sConfig.Rank         = 1;
  sConfig.SamplingTime = ADC_SAMPLETIME_3CYCLES;
  sConfig.Offset       = 0;

  switch (obj->pin) {
      case PA_0:
          sConfig.Channel = ADC_CHANNEL_0;
          break;
      case PA_1:
          sConfig.Channel = ADC_CHANNEL_1;
          break;
      case PA_4:
          sConfig.Channel = ADC_CHANNEL_4;
          break;
      case PB_0:
          sConfig.Channel = ADC_CHANNEL_8;
          break;
      case PC_1:
          sConfig.Channel = ADC_CHANNEL_11;
          break;
      case PC_0:
          sConfig.Channel = ADC_CHANNEL_10;
          break;
      default:
          return 0;
  }
  
  HAL_ADC_ConfigChannel(&AdcHandle, &sConfig);
    
  HAL_ADC_Start(&AdcHandle); // Start conversion
  
  HAL_ADC_PollForConversion(&AdcHandle, 10); // Wait end of conversion
  
  if (HAL_ADC_GetState(&AdcHandle) == HAL_ADC_STATE_EOC_REG)
  {  
      return(HAL_ADC_GetValue(&AdcHandle)); // Get conversion value
  }
  else
  {
      return 0;
  }
}

uint16_t analogin_read_u16(analogin_t *obj) {
  return(adc_read(obj));
}

float analogin_read(analogin_t *obj) {
  uint16_t value = adc_read(obj);
  return (float)value * (1.0f / (float)0xFFF); // 12 bits range
}

#endif