text: /*
   * This file is part of the MicroPython project, http://micropython.org/
   *
   * The MIT License (MIT)
   *
   * Copyright 2019 Sony Semiconductor Solutions Corporation
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   */
  
  #include <fcntl.h>
  #include <unistd.h>
  #include <sys/ioctl.h>
  
  #include <arch/chip/scu.h>
  #include <arch/chip/adc.h>
  
  #include "py/runtime.h"
  
  #include "shared-bindings/analogio/AnalogIn.h"
  
  typedef struct {
      const char* devpath;
      const mcu_pin_obj_t *pin;
      int fd;
  } analogin_dev_t;
  
  STATIC analogin_dev_t analogin_dev[] = {
      {"/dev/lpadc0", &pin_LPADC0, -1},
      {"/dev/lpadc1", &pin_LPADC1, -1},
      {"/dev/lpadc2", &pin_LPADC2, -1},
      {"/dev/lpadc3", &pin_LPADC3, -1},
      {"/dev/hpadc0", &pin_HPADC0, -1},
      {"/dev/hpadc1", &pin_HPADC1, -1},
  };
  
  void common_hal_analogio_analogin_construct(analogio_analogin_obj_t *self, const mcu_pin_obj_t *pin) {
      if (!pin->analog) {
          mp_raise_ValueError(translate("AnalogIn not supported on given pin"));
      }
  
      self->number = -1;
  
      for (int i = 0; i < MP_ARRAY_SIZE(analogin_dev); i++) {
          if (pin->number == analogin_dev[i].pin->number) {
              self->number = i;
              break;
          }
      }
  
      if (self->number < 0) {
          mp_raise_ValueError(translate("Pin does not have ADC capabilities"));
      }
  
      if (analogin_dev[self->number].fd < 0) {
          analogin_dev[self->number].fd = open(analogin_dev[self->number].devpath, O_RDONLY);
          if (analogin_dev[self->number].fd < 0) {
              mp_raise_ValueError(translate("Pin does not have ADC capabilities"));
          }
      }
  
      // SCU FIFO overwrite
      ioctl(analogin_dev[self->number].fd, SCUIOC_SETFIFOMODE, 1);
  
      // ADC FIFO size
      ioctl(analogin_dev[self->number].fd, ANIOC_CXD56_FIFOSIZE, 2);
  
      // start ADC
      ioctl(analogin_dev[self->number].fd, ANIOC_CXD56_START, 0);
  
      self->pin = pin;
  }
  
  void common_hal_analogio_analogin_deinit(analogio_analogin_obj_t *self) {
      if (common_hal_analogio_analogin_deinited(self)) {
          return;
      }
  
      // stop ADC
      ioctl(analogin_dev[self->number].fd, ANIOC_CXD56_STOP, 0);
      close(analogin_dev[self->number].fd);
      analogin_dev[self->number].fd = -1;
  
      self->pin = NULL;
  }
  
  bool common_hal_analogio_analogin_deinited(analogio_analogin_obj_t *self) {
      return analogin_dev[self->number].fd < 0;
  }
  
  uint16_t common_hal_analogio_analogin_get_value(analogio_analogin_obj_t *self) {
      uint16_t value = 0;
  
      read(analogin_dev[self->number].fd, &value, sizeof(value));
  
      return value;
  }
  
  // Reference voltage is a fixed value which is depending on the board.
  // e.g.)
  // - Reference Voltage of A4 and A5 pins on Main Board is 0.7V.
  // - Reference Voltage of A0 ~ A5 pins on External Interface board
  //   is selected 3.3V or 5.0V by a IO Volt jumper pin.
  float common_hal_analogio_analogin_get_reference_voltage(analogio_analogin_obj_t *self) {
      return 0.0f;
  }
  
  void analogin_reset(void) {
      for (int i = 0; i < MP_ARRAY_SIZE(analogin_dev); i++) {
          if (analogin_dev[i].fd >= 0) {
              // stop ADC
              ioctl(analogin_dev[i].fd, ANIOC_CXD56_STOP, 0);
              close(analogin_dev[i].fd);
              analogin_dev[i].fd = -1;
          }
      }
  }
  