text: /*****************************************************************************
   * configs/stm32butterfly2/src/stm32_adc.c
   *
   *   Copyright (C) 2016 Michał Łyszczek. All rights reserved.
   *   Author: Michał Łyszczek <michal.lyszczek@gmail.com>
   *
   * 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 NuttX 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 OWNER 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.
   ****************************************************************************/
  
  /*****************************************************************************
   * Included Files
   ****************************************************************************/
  
  #include <chip.h>
  #include <debug.h>
  #include <errno.h>
  
  #include "stm32_adc.h"
  
  /*****************************************************************************
   * Public Functions
   ****************************************************************************/
  
  /*****************************************************************************
   * Name: board_adc_setup
   *
   * Description:
   *   Function initializes channel 1 of adc1 and registers device as /dev/adc0
   ****************************************************************************/
  
  int board_adc_setup(void)
  {
    static bool initialized = false;
    uint8_t channel[1] = {10};
    struct adc_dev_s *adc;
    int rv;
  
    if (initialized)
      {
        return OK;
      }
  
    ainfo("INFO: Initializing ADC12_IN10\n");
    stm32_configgpio(GPIO_ADC12_IN10);
    if ((adc = stm32_adcinitialize(1, channel, 1)) == NULL)
      {
        aerr("ERROR: Failed to get adc interface\n");
        return -ENODEV;
      }
  
    if ((rv = adc_register("/dev/adc0", adc)) < 0)
      {
        aerr("ERROR: adc_register failed: %d\n", rv);
        return rv;
      }
  
    initialized = true;
    ainfo("INFO: ADC12_IN10 initialized succesfully\n");
    return OK;
  }
  