nuttx/boards/arm/stm32f0l0g0/b-l072z-lrwan1/src/stm32_adc.c

/****************************************************************************
 * boards/b-l072z-lrwan1/src/stm32_adc.c
 *
 *   Copyright (C) 2019 Gregory Nutt. All rights reserved.
 *   Author: Mateusz Szafoni <raiden00@railab.me>
 *
 * 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 <nuttx/config.h>

#include <stdbool.h>
#include <errno.h>
#include <debug.h>

#include <nuttx/board.h>
#include <nuttx/analog/adc.h>

#include "stm32.h"

#if defined(CONFIG_ADC) && defined(CONFIG_STM32F0L0G0_ADC1)

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

/* Configuration ************************************************************/

/* The number of ADC channels in the conversion list */

#define ADC1_NCHANNELS 2

/****************************************************************************
 * Private Function Prototypes
 ****************************************************************************/

/****************************************************************************
 * Private Data
 ****************************************************************************/

/* Identifying number of each ADC channel (even if NCHANNELS is less ) */

static const uint8_t g_chanlist1[2] =
{
  0,
  4,
};

/* Configurations of pins used by each ADC channel */

static const uint32_t g_pinlist1[2]  =
{
  GPIO_ADC1_IN0,                /* PA0/A0 */
  GPIO_ADC1_IN4                 /* PA4/A2 */
};

/****************************************************************************
 * Private Functions
 ****************************************************************************/

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: stm32_adc_setup
 *
 * Description:
 *   Initialize ADC and register the ADC driver.
 *
 ****************************************************************************/

int stm32_adc_setup(void)
{
  static bool initialized = false;
  FAR struct adc_dev_s *adc;
  int ret;
  int i;

  /* Check if we have already initialized */

  if (!initialized)
    {
      /* Configure the pins as analog inputs for the selected channels */

      for (i = 0; i < ADC1_NCHANNELS; i++)
        {
          stm32_configgpio(g_pinlist1[i]);
        }

      /* Call stm32_adcinitialize() to get an instance of the ADC interface */

      adc = stm32_adcinitialize(1, g_chanlist1, ADC1_NCHANNELS);
      if (adc == NULL)
        {
          aerr("ERROR: Failed to get ADC interface 1\n");
          return -ENODEV;
        }

      /* Register the ADC driver at "/dev/adc0" */

      ret = adc_register("/dev/adc0", adc);
      if (ret < 0)
        {
          aerr("ERROR: adc_register /dev/adc0 failed: %d\n", ret);
          return ret;
        }

      initialized = true;
    }

  return OK;
}

#endif /* CONFIG_ADC && CONFIG_STM32F0L0G0_ADC1 */