text: /************************************************************************************
   * configs/zkit-arm-1769/src/up_adc.c
   * arch/arm/src/board/up_adc.c
   *
   *   Copyright (C) 2013 Zilogic Systems. All rights reserved.
   *   Author: Kannan <code@nuttx.org>
   *
   * Based on configs/stm3220g-eval/src/up_adc.c
   *
   *   Copyright (C) 2012 Gregory Nutt. All rights reserved.
   *   Author: Gregory Nutt <gnutt@nuttx.org>
   *
   * 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 <errno.h>
  #include <debug.h>
  
  #include <nuttx/analog/adc.h>
  #include <arch/board/board.h>
  
  #include "chip.h"
  #include "up_arch.h"
  
  #include "lpc17_adc.h"
  #include "zkitarm_internal.h"
  
  #ifdef CONFIG_ADC
  
  /************************************************************************************
   * Definitions
   ************************************************************************************/
  
  /************************************************************************************
   * Private Data
   ************************************************************************************/
  
  /************************************************************************************
   * Private Functions
   ************************************************************************************/
  
  /************************************************************************************
   * Public Functions
   ************************************************************************************/
  
  /************************************************************************************
   * Name: adc_devinit
   *
   * Description:
   *   All LPC17 architectures must provide the following interface to work with
   *   examples/adc.
   *
   ************************************************************************************/
  
  int adc_devinit(void)
  {
    static bool initialized = false;
    struct adc_dev_s *adc;
    int ret;
  
    /* Check if we have already initialized */
  
    if (!initialized)
      {
        /* Call lpc17_adcinitialize() to get an instance of the ADC interface */
  
        adc = lpc17_adcinitialize();
        if (adc == NULL)
          {
            adbg("ERROR: Failed to get ADC interface\n");
            return -ENODEV;
          }
  
        /* Register the ADC driver at "/dev/adc0" */
  
        ret = adc_register("/dev/adc0", adc);
        if (ret < 0)
          {
            adbg("adc_register failed: %d\n", ret);
            return ret;
          }
  
        /* Now we are initialized */
  
        initialized = true;
      }
  
    return OK;
  }
  
  #endif /* CONFIG_ADC */
  