text: /* 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 "analogout_api.h"
  
  #if DEVICE_ANALOGOUT
  
  #include "cmsis.h"
  #include "pinmap.h"
  #include "mbed_error.h"
  #include "PeripheralPins.h"
  
  #define DAC_RANGE (0xFFF) // 12 bits
  
  static DAC_HandleTypeDef DacHandle;
  
  // These variables are used for the "free" function
  static int pa4_used = 0;
  static int pa5_used = 0;
  
  void analogout_init(dac_t *obj, PinName pin)
  {
      DAC_ChannelConfTypeDef sConfig;
  
      // Get the peripheral name from the pin and assign it to the object
      obj->dac = (DACName)pinmap_peripheral(pin, PinMap_DAC);
      MBED_ASSERT(obj->dac != (DACName)NC);
  
      // Configure GPIO
      pinmap_pinout(pin, PinMap_DAC);
  
      // Save the pin for future use
      obj->pin = pin;
  
      // Enable DAC clock
      if (obj->dac == DAC_1) {
          __DAC1_CLK_ENABLE();
      }
  
      if (obj->dac == DAC_2) {
          __DAC2_CLK_ENABLE();
      }
  
      // Configure DAC
      DacHandle.Instance = (DAC_TypeDef *)(obj->dac);
  
      sConfig.DAC_Trigger      = DAC_TRIGGER_NONE;
      sConfig.DAC_OutputBuffer = DAC_OUTPUTBUFFER_DISABLE;
  
      if (pin == PA_4) {
          HAL_DAC_ConfigChannel(&DacHandle, &sConfig, DAC_CHANNEL_1);
          pa4_used = 1;
      }
  
      if (pin == PA_5) {
          HAL_DAC_ConfigChannel(&DacHandle, &sConfig, DAC_CHANNEL_2);
          pa5_used = 1;
      }
  
      if (pin == PA_6) {
          HAL_DAC_ConfigChannel(&DacHandle, &sConfig, DAC_CHANNEL_1);
      }
  
      analogout_write_u16(obj, 0);
  }
  
  void analogout_free(dac_t *obj)
  {
      // Reset DAC and disable clock
      if (obj->pin == PA_4) pa4_used = 0;
      if (obj->pin == PA_5) pa5_used = 0;
  
      if ((pa4_used == 0) && (pa5_used == 0)) {
          __DAC1_FORCE_RESET();
          __DAC1_RELEASE_RESET();
          __DAC1_CLK_DISABLE();
      }
  
      if (obj->pin == PA_6) {
          __DAC2_FORCE_RESET();
          __DAC2_RELEASE_RESET();
          __DAC2_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)
  {
      if ((obj->pin == PA_4) || (obj->pin == PA_6)) {
          HAL_DAC_SetValue(&DacHandle, DAC_CHANNEL_1, DAC_ALIGN_12B_R, value);
          HAL_DAC_Start(&DacHandle, DAC_CHANNEL_1);
      }
  
      if (obj->pin == PA_5) {
          HAL_DAC_SetValue(&DacHandle, DAC_CHANNEL_2, DAC_ALIGN_12B_R, value);
          HAL_DAC_Start(&DacHandle, DAC_CHANNEL_2);
      }
  }
  
  static inline int dac_read(dac_t *obj)
  {
      if ((obj->pin == PA_4) || (obj->pin == PA_6)) {
          return (int)HAL_DAC_GetValue(&DacHandle, DAC_CHANNEL_1);
      } else if (obj->pin == PA_5) {
          return (int)HAL_DAC_GetValue(&DacHandle, DAC_CHANNEL_2);
      } else {
          return 0;
      }
  }
  
  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
  