File content as of revision 291:bdc8a81aee9a:

/* 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 "mbed_assert.h"
#include "analogin_api.h"

#if DEVICE_ANALOGIN

#include "wait_api.h"
#include "cmsis.h"
#include "pinmap.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_2, ADC_1, STM_PIN_DATA(STM_MODE_ANALOG, GPIO_NOPULL, 0)}, // ADC1_IN2
    {PA_3, ADC_1, STM_PIN_DATA(STM_MODE_ANALOG, GPIO_NOPULL, 0)}, // ADC1_IN3
    {PA_4, ADC_1, STM_PIN_DATA(STM_MODE_ANALOG, GPIO_NOPULL, 0)}, // ADC1_IN4
    {PA_5, ADC_1, STM_PIN_DATA(STM_MODE_ANALOG, GPIO_NOPULL, 0)}, // ADC1_IN5
    {PA_6, ADC_1, STM_PIN_DATA(STM_MODE_ANALOG, GPIO_NOPULL, 0)}, // ADC1_IN6
    {PA_7, ADC_1, STM_PIN_DATA(STM_MODE_ANALOG, GPIO_NOPULL, 0)}, // ADC1_IN7
    {PB_0, ADC_1, STM_PIN_DATA(STM_MODE_ANALOG, GPIO_NOPULL, 0)}, // ADC1_IN8
    {PB_1, ADC_1, STM_PIN_DATA(STM_MODE_ANALOG, GPIO_NOPULL, 0)}, // ADC1_IN9
    {PC_0, ADC_1, STM_PIN_DATA(STM_MODE_ANALOG, GPIO_NOPULL, 0)}, // ADC1_IN10
    {PC_1, ADC_1, STM_PIN_DATA(STM_MODE_ANALOG, GPIO_NOPULL, 0)}, // ADC1_IN11
    {PC_2, ADC_1, STM_PIN_DATA(STM_MODE_ANALOG, GPIO_NOPULL, 0)}, // ADC1_IN12
    {PC_3, ADC_1, STM_PIN_DATA(STM_MODE_ANALOG, GPIO_NOPULL, 0)}, // ADC1_IN13
    {PC_4, ADC_1, STM_PIN_DATA(STM_MODE_ANALOG, GPIO_NOPULL, 0)}, // ADC1_IN14
    {PC_5, ADC_1, STM_PIN_DATA(STM_MODE_ANALOG, GPIO_NOPULL, 0)}, // ADC1_IN15
    {NC,   NC,    0}
};

ADC_HandleTypeDef AdcHandle;

int adc_inited = 0;

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

    // 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;

        AdcHandle.Instance = (ADC_TypeDef *)(obj->adc);

        // Enable ADC clock
        __ADC1_CLK_ENABLE();

        // Configure ADC
        AdcHandle.Init.OversamplingMode      = DISABLE;
        AdcHandle.Init.ClockPrescaler        = ADC_CLOCKPRESCALER_PCLK_DIV2; // ADCCLK = 8 MHz (HSI 16 MHz / 2)
        AdcHandle.Init.Resolution            = ADC_RESOLUTION12b;
        AdcHandle.Init.SamplingTime          = ADC_SAMPLETIME_7CYCLES_5;
        AdcHandle.Init.ScanDirection         = ADC_SCAN_DIRECTION_UPWARD;
        AdcHandle.Init.DataAlign             = ADC_DATAALIGN_RIGHT;
        AdcHandle.Init.ContinuousConvMode    = DISABLE;
        AdcHandle.Init.DiscontinuousConvMode = DISABLE;
        AdcHandle.Init.ExternalTrigConvEdge  = ADC_EXTERNALTRIG_EDGE_NONE;
        AdcHandle.Init.ExternalTrigConv      = ADC_EXTERNALTRIG0_T6_TRGO; // Not used here
        AdcHandle.Init.DMAContinuousRequests = DISABLE;
        AdcHandle.Init.EOCSelection          = EOC_SINGLE_CONV;
        AdcHandle.Init.Overrun               = OVR_DATA_PRESERVED;
        AdcHandle.Init.LowPowerAutoWait      = ENABLE;
        AdcHandle.Init.LowPowerFrequencyMode = DISABLE; // To be enabled only if ADC clock < 2.8 MHz
        AdcHandle.Init.LowPowerAutoOff       = DISABLE;
        HAL_ADC_Init(&AdcHandle);
        
        // Calibration
        HAL_ADCEx_Calibration_Start(&AdcHandle, ADC_SINGLE_ENDED);
        
        __HAL_ADC_ENABLE(&AdcHandle);
    }
}

static inline uint16_t adc_read(analogin_t *obj) {
    ADC_ChannelConfTypeDef sConfig;

    AdcHandle.Instance = (ADC_TypeDef *)(obj->adc);

    // Configure ADC channel
    switch (obj->pin) {
        case PA_0:
            sConfig.Channel = ADC_CHANNEL_0;
            break;
        case PA_1:
            sConfig.Channel = ADC_CHANNEL_1;
            break;
        case PA_2:
            sConfig.Channel = ADC_CHANNEL_2;
            break;
        case PA_3:
            sConfig.Channel = ADC_CHANNEL_3;
            break;
        case PA_4:
            sConfig.Channel = ADC_CHANNEL_4;
            break;
        case PA_5:
            sConfig.Channel = ADC_CHANNEL_5;
            break;
        case PA_6:
            sConfig.Channel = ADC_CHANNEL_6;
            break;
        case PA_7:
            sConfig.Channel = ADC_CHANNEL_7;
            break;
        case PB_0:
            sConfig.Channel = ADC_CHANNEL_8;
            break;
        case PB_1:
            sConfig.Channel = ADC_CHANNEL_9;
            break;
        case PC_0:
            sConfig.Channel = ADC_CHANNEL_10;
            break;
        case PC_1:
            sConfig.Channel = ADC_CHANNEL_11;
            break;
        case PC_2:
            sConfig.Channel = ADC_CHANNEL_12;
            break;
        case PC_3:
            sConfig.Channel = ADC_CHANNEL_13;
            break;
        case PC_4:
            sConfig.Channel = ADC_CHANNEL_14;
            break;
        case PC_5:
            sConfig.Channel = ADC_CHANNEL_15;
            break;
        default:
            return 0;
    }

    ADC1->CHSELR = 0; // [TODO] Workaround. To be removed after Cube driver is corrected.
    HAL_ADC_ConfigChannel(&AdcHandle, &sConfig);

    HAL_ADC_Start(&AdcHandle); // Start conversion

    // Wait end of conversion and get value
    if (HAL_ADC_PollForConversion(&AdcHandle, 10) == HAL_OK) {
        return (HAL_ADC_GetValue(&AdcHandle));
    } 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