File content as of revision 217:d0ccc61c1fd4:

/* 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 "analogout_api.h"

#if DEVICE_ANALOGOUT

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

#define DAC_RANGE (0xFFF) // 12 bits

static const PinMap PinMap_DAC[] = {
    {PA_4, DAC_1, STM_PIN_DATA(STM_MODE_ANALOG, GPIO_NOPULL, 0)}, // DAC_OUT
    {NC,   NC,    0}
};

static DAC_HandleTypeDef DacHandle;

void analogout_init(dac_t *obj, PinName pin) {
    DAC_ChannelConfTypeDef sConfig;

    DacHandle.Instance = DAC;

    // Get the peripheral name (DAC_1, ...) from the pin and assign it to the object
    obj->dac = (DACName)pinmap_peripheral(pin, PinMap_DAC);

    if (obj->dac == (DACName)NC) {
        error("DAC pin mapping failed");
    }

    // Configure GPIO
    pinmap_pinout(pin, PinMap_DAC);

    // Save the channel for future use
    obj->pin = pin;

    // Enable DAC clock
    __DAC_CLK_ENABLE();

    // Configure DAC
    sConfig.DAC_Trigger      = DAC_TRIGGER_NONE;
    sConfig.DAC_OutputBuffer = DAC_OUTPUTBUFFER_DISABLE;

    HAL_DAC_ConfigChannel(&DacHandle, &sConfig, DAC_CHANNEL_1);

    analogout_write_u16(obj, 0);
}

void analogout_free(dac_t *obj) {
    // Reset DAC and disable clock
    __DAC_FORCE_RESET();
    __DAC_RELEASE_RESET();
    __DAC_CLK_DISABLE();

    // Configure GPIO
    pin_function(obj->pin, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0));
}

static inline void dac_write(dac_t *obj, uint16_t value) {
    HAL_DAC_SetValue(&DacHandle, DAC_CHANNEL_1, DAC_ALIGN_12B_R, value);
    HAL_DAC_Start(&DacHandle, DAC_CHANNEL_1);
}

static inline int dac_read(dac_t *obj) {
    return (int)HAL_DAC_GetValue(&DacHandle, DAC_CHANNEL_1);
}

void analogout_write(dac_t *obj, float value) {
    if (value < 0.0f) {
        dac_write(obj, 0); // Min value
    } else if (value > 1.0f) {
        dac_write(obj, (uint16_t)DAC_RANGE); // Max value
    } else {
        dac_write(obj, (uint16_t)(value * (float)DAC_RANGE));
    }
}

void analogout_write_u16(dac_t *obj, uint16_t value) {
    if (value > (uint16_t)DAC_RANGE) {
        dac_write(obj, (uint16_t)DAC_RANGE); // Max value
    } else {
        dac_write(obj, value);
    }
}

float analogout_read(dac_t *obj) {
    uint32_t value = dac_read(obj);
    return (float)((float)value * (1.0f / (float)DAC_RANGE));
}

uint16_t analogout_read_u16(dac_t *obj) {
    return (uint16_t)dac_read(obj);
}

#endif // DEVICE_ANALOGOUT