/*
 * pga23xx.cpp: burr brown volume control chip (spi based)
 *
 *
 *  (part of the "VoluMaster(tm)" system)
 *
 *  An open-source arduino controller-based digital volume control and input/output selector
 *
 *
 *  LICENSE
 *  -------
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *  
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *  
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */


#include "pga23xx.h"

#include <Wire.h>
#include <stdio.h>  //not needed yet
#include <string.h> //needed for strlen()
#include <inttypes.h>

#include "WConstants.h"  //all things wiring / arduino


#include "config.h"



// ctor
PGA23XX::PGA23XX( void )
{
}



// dtor
//
//PGA23XX::~PGA23XX( void )
//{
//}




void
PGA23XX::init( void )
{
#ifdef USE_PGA_SPI
  pinMode(PGA_CS_PIN,    OUTPUT);    // pga-chipselect pin
  pinMode(PGA_SDATA_PIN, OUTPUT);    // pga-data-out (our data out to it) pin
  pinMode(PGA_SCK_PIN,   OUTPUT);    // pga-clock pin
#endif


#ifdef USE_PGA_I2C
  PCF8574_PE_write(0x00);
#endif
}



#ifdef SINGLE_DB_STEPS
void
PGA23XX::map_pga_value_to_db( uint8_t pga_int_value, uint8_t *db_value, uint8_t *negative_db, uint8_t *half_db_flag )
{
  int db = (pga_int_value - 96);

  *half_db_flag = 0;
  
  if (db < 0) {
    *negative_db = 1;  // true
    *db_value = (byte)(-db);   // make it positive (abs value)
  } 
  else {
    *negative_db = 0;  // false
    *db_value = (byte)db;
  }
}
#endif



#ifdef HALF_DB_STEPS
void
PGA23XX::map_pga_value_to_db( uint8_t pga_int_value, uint8_t *db_value, uint8_t *negative_db, uint8_t *half_db_flag )
{
  float db = 31.5 - (255.0 - (float)pga_int_value) / 2.0;

  // odd numbers in the 0..255 range mean half-db values
  if ( (pga_int_value & 0x01) == 1) {
    *half_db_flag = 1;
  } else {
    *half_db_flag = 0;
  }

  if (db < 0) {
    *negative_db = 1;  // true
    *db_value = (byte)(-db);   // make it positive (abs value)
  } 
  else {
    *negative_db = 0;  // false
    *db_value = (byte)db;
  }
}
#endif







/*
 * philips (like) i2c to parallel 8bit port expander chip
 */

#ifdef USE_PGA_I2C
void 
PGA23XX::PCF8574_PE_write( uint8_t _data ) 
{
  Wire.beginTransmission(I2C_PGA_PE_ADDR);
  Wire.send(_data);
  Wire.endTransmission();
}
#endif // USE_PGA_I2C






#ifdef USE_PGA_I2C
uint8_t
PGA23XX::PCF8574_PE_read( void ) 
{
  uint8_t _data;

  Wire.requestFrom(I2C_PGA_PE_ADDR, 1);
  if (Wire.available()) {
    _data = Wire.receive();
  }

  return _data;
}
#endif // USE_PGA_I2C





#ifdef USE_PGA_SPI
void 
PGA23XX::SPI_write( uint8_t out_spi_byte )
{
  uint8_t i;

#ifdef DEBUG_PGA
  Serial.print("PGA:");
  Serial.println((int)out_spi_byte);
#endif

  // loop thru each of the 8-bits in the byte
  for (i=0; i < 8; i++) {

    // strobe clock
    //PCF8574_PE_write(PGA_I2C_CS_LOW | PGA_I2C_SCK_LOW | PGA_I2C_SDATA_LOW);
    digitalWrite(PGA_SCK_PIN, LOW);
    

    // send the bit (we look at the high order bit and 'print' that to the remote device)
    if (0x80 & out_spi_byte) {  // MSB is set
      //PCF8574_PE_write(PGA_I2C_CS_LOW | PGA_I2C_SCK_LOW | PGA_I2C_SDATA_HI);
      digitalWrite(PGA_SDATA_PIN, HIGH);
    
    } else {
      //PCF8574_PE_write(PGA_I2C_CS_LOW | PGA_I2C_SCK_LOW | PGA_I2C_SDATA_LOW);
      digitalWrite(PGA_SDATA_PIN, LOW);
    }


    // unstrobe the clock via local SPI
    digitalWrite(PGA_SCK_PIN, HIGH);

    // unstrobe via i2c
    if (0x80 & out_spi_byte) {  // MSB is set
      //PCF8574_PE_write(PGA_I2C_CS_LOW | PGA_I2C_SCK_HI | PGA_I2C_SDATA_HI);
    } else {
      //PCF8574_PE_write(PGA_I2C_CS_LOW | PGA_I2C_SCK_HI | PGA_I2C_SDATA_LOW);
    }
    

    // get the next bit  
    out_spi_byte <<= 1;   // left-shift the byte by 1 bit
  }
}
#endif






#ifdef USE_PGA_I2C
void 
PGA23XX::SPI_write( uint8_t out_spi_byte )
{
  uint8_t i;

#ifdef DEBUG_PGA
  Serial.print("PGA:");
  Serial.println((int)out_spi_byte);
#endif

  // loop thru each of the 8-bits in the byte
  for (i=0; i < 8; i++) {

    // strobe clock
    PCF8574_PE_write(PGA_I2C_CS_LOW | PGA_I2C_SCK_LOW | PGA_I2C_SDATA_LOW);
    //digitalWrite(PGA_SCK_PIN, LOW);
    

    // send the bit (we look at the high order bit and 'print' that to the remote device)
    if (0x80 & out_spi_byte) {  // MSB is set
      PCF8574_PE_write(PGA_I2C_CS_LOW | PGA_I2C_SCK_LOW | PGA_I2C_SDATA_HI);
      //digitalWrite(PGA_SDATA_PIN, HIGH);
    
    } else {
      PCF8574_PE_write(PGA_I2C_CS_LOW | PGA_I2C_SCK_LOW | PGA_I2C_SDATA_LOW);
      //digitalWrite(PGA_SDATA_PIN, LOW);
    }


    // unstrobe the clock via local SPI
    //digitalWrite(PGA_SCK_PIN, HIGH);

    // unstrobe via i2c
    if (0x80 & out_spi_byte) {  // MSB is set
      PCF8574_PE_write(PGA_I2C_CS_LOW | PGA_I2C_SCK_HI | PGA_I2C_SDATA_HI);
    } else {
      PCF8574_PE_write(PGA_I2C_CS_LOW | PGA_I2C_SCK_HI | PGA_I2C_SDATA_LOW);
    }
    

    // get the next bit  
    out_spi_byte <<= 1;   // left-shift the byte by 1 bit
  }
}
#endif






#ifdef USE_PGA_SPI
 
// note, for typical use, we assume left==right

void 
PGA23XX::PGA_set_volume( uint8_t left, uint8_t right )
{
  digitalWrite(PGA_CS_PIN, LOW);     // assert CS

  SPI_write(left /*<< 1*/);          // left value (0..255)
  SPI_write(right /*<< 1*/);	     // right value (0..255)

  digitalWrite(PGA_CS_PIN, HIGH);    // deassert CS
}
#endif






#ifdef USE_PGA_I2C
 
// note, for typical use, we assume left==right

void 
PGA23XX::set_volume( uint8_t left, uint8_t right )
{
  PCF8574_PE_write(PGA_I2C_CS_HI);     // start from high (logical-NOT on chip-select)
  //delayMicroseconds(5);
  PCF8574_PE_write(PGA_I2C_CS_LOW);    // begin getting the chip's attention

  SPI_write(left /*<< 1*/);            // left value (0..255)
  SPI_write(right /*<< 1*/);	       // right value (0..255)

  PCF8574_PE_write(PGA_I2C_CS_HI);
  //delayMicroseconds(5);
}
#endif