#include "ayn_sc8721.h"

SC8721::SC8721(unsigned char pin_sda, unsigned char pin_scl, unsigned char pin_ce) {
  _pin_sda = pin_sda;
  _pin_scl = pin_scl;
  _pin_ce = pin_ce;
  // 配置I2C通信引脚
  Wire.begin(_pin_sda, _pin_scl);
  // 设置芯片使能引脚
  pinMode(_pin_ce, OUTPUT);
  digitalWrite(_pin_ce, LOW);
}

void SC8721::chipStanby(bool enable) {
  digitalWrite(_pin_ce, HIGH);

  Wire.beginTransmission(i2c_address);
  Wire.write(REG_GLOBAL_CTRL);
  if (enable)
    Wire.write(0x04);
  else
    Wire.write(0x00);
  Wire.endTransmission();
}

void SC8721::chipShutdown(bool ce_signal) {
  digitalWrite(_pin_ce, ce_signal);
}

bool SC8721::setOutputCurrentLimitRegister(float iout_ilim) {
  int cso_set = 0;
  // 对输入值进行判断
  if (iout_ilim > max_iout_ilim)
    return 0;
  else {
    cso_set = ((iout_ilim * Rs * Rcso) / 8) - 1;

    Wire.beginTransmission(i2c_address);
    Wire.write(REG_CSO);
    Wire.write(cso_set);
    Wire.endTransmission();
  }
  return cso_set;
}

void SC8721::setCableDropCompensation(unsigned char level) {
  Wire.beginTransmission(i2c_address);
  Wire.write(REG_SLOPE_COMP);
  Wire.write(level);
  Wire.endTransmission();
}

void SC8721::setOutputVoltageRegister(float voltage) {
  unsigned int voltage_mv = voltage * 1000;
  unsigned int offset_div20 = 0;
  bool fb_dir = 0;

  // 判断偏移增量方向 datasheet8.3.2
  // offset = | VOUT ± VOUT_REF(5v) |
  //        = (REG_VOUT_SET_MSB*4 + REG_VOUT_SET<1:0>) * 20
  if (voltage_mv >= 5000) {
    fb_dir = 0;
    offset_div20 = (voltage_mv - 5000) / 20;
  } else {
    fb_dir = 1;
    offset_div20 = (5000 - voltage_mv) / 20;
  }
  //写入VOUT_SET_MSB Register
  Wire.beginTransmission(i2c_address);
  Wire.write(REG_VOUT_SET_MSB);
  Wire.write(offset_div20 >> 2);
  Wire.endTransmission();

  Wire.beginTransmission(i2c_address);
  Wire.write(REG_VOUT_SET);
  //判断增量方向决定写入VOUT_SET Registe内容
  if (!fb_dir) {
    Wire.write((offset_div20 & 0x03) | 0x18);
  } else {
    Wire.write((offset_div20 & 0x03) | 0x1C);
  }
  Wire.endTransmission();
}

void SC8721::loadSettingRegister() {
  Wire.beginTransmission(i2c_address);
  Wire.write(REG_GLOBAL_CTRL);
  Wire.write(0x02);
  Wire.endTransmission();
}

void SC8721::setSwitchFreq(unsigned char level) {
  Wire.beginTransmission(i2c_address);
  Wire.write(REG_FREQ_SET);
  Wire.write(level);
  Wire.endTransmission();
}

void SC8721::outputVoltage(float voltage) {
  setOutputVoltageRegister(voltage);
  loadSettingRegister();
}

void SC8721::outputCurrentLimit(float iout_ilim) {
  setOutputCurrentLimitRegister(iout_ilim);
  loadSettingRegister();
}