/*
   * Copyright (C) 2014 PHYTEC Messtechnik GmbH
   *               2017 HAW Hamburg
   *
   * This file is subject to the terms and conditions of the GNU Lesser
   * General Public License v2.1. See the file LICENSE in the top level
   * directory for more details.
   *
   */
  
  /**
   * @ingroup     drivers_tmp006
   * @{
   *
   * @file
   * @brief       Driver for the TI TMP006 Infrared Thermopile Sensor.
   *
   * @author      Johann Fischer <j.fischer@phytec.de>
   * @author      Peter Kietzmann <peter.kietzmann@haw-hamburg.de>
   * @author      Sebastian Meiling <s@mlng.net>
   *
   * @}
   */
  
  #include <stdint.h>
  #include <stdbool.h>
  #include <string.h>
  #include <math.h>
  
  #include "log.h"
  #include "periph/i2c.h"
  #include "tmp006.h"
  #include "tmp006_regs.h"
  
  #define ENABLE_DEBUG                (0)
  #include "debug.h"
  
  #define TMP006_CONFIG_RST           (1 << 15)
  
  #define TMP006_CONFIG_MOD_SHIFT     (12U)
  #define TMP006_CONFIG_MOD_MASK      (0x7000)
  #define TMP006_CONFIG_MOD(x)        (((uint16_t)(((uint16_t)(x)) << TMP006_CONFIG_MOD_SHIFT))\
                                       & TMP006_CONFIG_MOD_MASK)
  #define TMP006_CONFIG_MOD_CC        (0x07)
  #define TMP006_CONFIG_MOD_OFF       (0x00)
  
  #define TMP006_CONFIG_CR_SHIFT      (9U)
  #define TMP006_CONFIG_CR_MASK       (0x0E00)
  #define TMP006_CONFIG_CR(x)         (((uint16_t)(((uint16_t)(x)) << TMP006_CONFIG_CR_SHIFT))\
                                       & TMP006_CONFIG_CR_MASK)
  
  #define TMP006_CONFIG_DRDY_PIN_EN   (1 << 8)
  #define TMP006_CONFIG_DRDY          (1 << 7)
  
  #define TMP006_MID_VALUE            (0x5449) /**< Manufacturer ID */
  #define TMP006_DID_VALUE            (0x0067) /**< Device ID */
  
  #define I2C_SPEED                   I2C_SPEED_FAST
  #define BUS                         (dev->p.i2c)
  #define ADDR                        (dev->p.addr)
  
  int tmp006_init(tmp006_t *dev, const tmp006_params_t *params)
  {
      /* check parameters */
      assert(dev && params);
  
      uint8_t reg[2];
      uint16_t tmp;
  
      /* initialize the device descriptor */
      memcpy(&dev->p, params, sizeof(tmp006_params_t));
  
      if (dev->p.rate > TMP006_CONFIG_CR_AS16) {
          LOG_ERROR("tmp006_init: invalid conversion rate!\n");
          return -TMP006_ERROR_CONF;
      }
  
      /* setup the I2C bus */
      i2c_acquire(BUS);
      if (i2c_init_master(BUS, I2C_SPEED) < 0) {
          i2c_release(BUS);
          LOG_ERROR("tmp006_init: error initializing I2C bus\n");
          return -TMP006_ERROR_BUS;
      }
      /* test device id */
      if (i2c_read_regs(BUS, ADDR, TMP006_REGS_DEVICE_ID, reg, 2) != 2) {
          i2c_release(BUS);
          LOG_ERROR("tmp006_init: error reading device ID!\n");
          return -TMP006_ERROR_BUS;
      }
      tmp = ((uint16_t)reg[0] << 8) | reg[1];
      if (tmp != TMP006_DID_VALUE) {
          return -TMP006_ERROR_DEV;
      }
      /* set conversion rate */
      tmp = TMP006_CONFIG_CR(dev->p.rate);
      reg[0] = (tmp >> 8);
      reg[1] = tmp;
      if (i2c_write_regs(BUS, ADDR, TMP006_REGS_CONFIG, reg, 2) != 2) {
          i2c_release(BUS);
          LOG_ERROR("tmp006_init: error setting conversion rate!\n");
          return -TMP006_ERROR_BUS;
      }
      i2c_release(BUS);
  
      return TMP006_OK;
  }
  
  int tmp006_reset(const tmp006_t *dev)
  {
      uint8_t reg[2];
      uint16_t tmp = TMP006_CONFIG_RST;
      reg[0] = (tmp >> 8);
      reg[1] = tmp;
  
      /* Acquire exclusive access to the bus. */
      i2c_acquire(BUS);
      if (i2c_write_regs(BUS, ADDR, TMP006_REGS_CONFIG, reg, 2) != 2) {
          i2c_release(BUS);
          return -TMP006_ERROR_BUS;
      }
      i2c_release(BUS);
      return TMP006_OK;
  }
  
  int tmp006_set_active(const tmp006_t *dev)
  {
      uint8_t reg[2];
  
      i2c_acquire(BUS);
      if (i2c_read_regs(BUS, ADDR, TMP006_REGS_CONFIG, reg, 2) != 2) {
          i2c_release(BUS);
          return -TMP006_ERROR_BUS;
      }
  
      reg[0] |= (TMP006_CONFIG_MOD(TMP006_CONFIG_MOD_CC) >> 8);
      if (i2c_write_regs(BUS, ADDR, TMP006_REGS_CONFIG, reg, 2) != 2) {
          i2c_release(BUS);
          return -TMP006_ERROR_BUS;
      }
      i2c_release(BUS);
      return TMP006_OK;
  }
  
  int tmp006_set_standby(const tmp006_t *dev)
  {
      uint8_t reg[2];
  
      i2c_acquire(BUS);
      if (i2c_read_regs(BUS, ADDR, TMP006_REGS_CONFIG, reg, 2) != 2) {
          i2c_release(BUS);
          return -TMP006_ERROR_BUS;
      }
  
      reg[0] &= ~(TMP006_CONFIG_MOD(TMP006_CONFIG_MOD_CC) >> 8);
      if (i2c_write_regs(BUS, ADDR, TMP006_REGS_CONFIG, reg, 2) != 2) {
          i2c_release(BUS);
          return -TMP006_ERROR_BUS;
      }
      i2c_release(BUS);
      return TMP006_OK;
  }
  
  int tmp006_read(const tmp006_t *dev, int16_t *rawv, int16_t *rawt, uint8_t *drdy)
  {
      uint8_t reg[2];
  
      i2c_acquire(BUS);
      /* Register bytes are sent MSB first. */
      if (i2c_read_regs(BUS, ADDR, TMP006_REGS_CONFIG, reg, 2) != 2) {
          i2c_release(BUS);
          return -TMP006_ERROR_BUS;
      }
      i2c_release(BUS);
  
      *drdy = reg[1] & (TMP006_CONFIG_DRDY);
      if (!(*drdy)) {
          LOG_DEBUG("tmp006_read: conversion in progress!\n");
          return -TMP006_ERROR;
      }
  
      i2c_acquire(BUS);
      if (i2c_read_regs(BUS, ADDR, TMP006_REGS_V_OBJECT, reg, 2) != 2) {
          i2c_release(BUS);
          return -TMP006_ERROR_BUS;
      }
      i2c_release(BUS);
  
      *rawv = ((uint16_t)reg[0] << 8) | reg[1];
  
      i2c_acquire(BUS);
      if (i2c_read_regs(BUS, ADDR, TMP006_REGS_T_AMBIENT, reg, 2) != 2) {
          i2c_release(BUS);
          return -TMP006_ERROR_BUS;
      }
      i2c_release(BUS);
      *rawt = ((uint16_t)reg[0] << 8) | reg[1];
      return TMP006_OK;
  }
  
  void tmp006_convert(int16_t rawv, int16_t rawt,  float *tamb, float *tobj)
  {
      /* calculate die temperature */
      *tamb = (double)rawt / 128.0;
      /* die temperature in Kelvin */
      double tdie_k = *tamb + 273.15;
  
      /* calculate sensor voltage */
      double sens_v = (double)rawv * TMP006_CCONST_LSB_SIZE;
  
      double tdiff = tdie_k - TMP006_CCONST_TREF;
      double tdiff_pow2 = pow(tdiff, 2);
  
      double s = TMP006_CCONST_S0 * (1 + TMP006_CCONST_A1 * tdiff
                                     + TMP006_CCONST_A2 * tdiff_pow2);
  
      double v_os = TMP006_CCONST_B0 + TMP006_CCONST_B1 * tdiff
                    + TMP006_CCONST_B2 * tdiff_pow2;
  
      double f_obj = (sens_v - v_os) + TMP006_CCONST_C2 * pow((sens_v - v_os), 2);
  
      double t = pow(pow(tdie_k, 4) + (f_obj / s), 0.25);
      /* calculate object temperature in Celsius */
      *tobj = (t - 273.15);
  }
  
  int tmp006_read_temperature(const tmp006_t *dev, int16_t *ta, int16_t *to)
  {
      int16_t rawtemp, rawvolt;
      float tamb, tobj;
      uint8_t drdy;
      tmp006_read(dev, &rawvolt, &rawtemp, &drdy);
  
      if (!drdy) {
          return TMP006_ERROR;
      }
      tmp006_convert(rawvolt, rawtemp,  &tamb, &tobj);
      *ta = (int16_t)(tamb*100);
      *to = (int16_t)(tobj*100);
  
      return TMP006_OK;
  }