#include <p18f1320.h>
#include <sw_i2c.h>
#include <delays.h>
#include <ADC.h>

#define CS8416_ADDRESS 0x20
#define TAS5076_ADDRESS 0x36
#define I2C_WRITE   0
#define I2C_READ    1

unsigned char I2CWrite(unsigned char address, unsigned char subaddress, unsigned char writevalue)
{
	unsigned char  cnt;
	unsigned char var;
	char err;
	
	SWStartI2C();
	var = SWWriteI2C(address + I2C_WRITE);
	SWAckI2C();
	var = SWWriteI2C(subaddress); // word address
	SWAckI2C();
	var = SWWriteI2C(writevalue); // data
	SWAckI2C();
	SWStopI2C();
	
}

unsigned char I2CRead(unsigned char address, unsigned char subaddress)
{
	unsigned char  cnt;
	unsigned char var;
	char err;
	
	SWStartI2C();
	var = SWWriteI2C(address + I2C_WRITE);
	SWAckI2C();
	var = SWWriteI2C(subaddress); // word address
	SWAckI2C();
	
	SWRestartI2C();
	var = SWWriteI2C(address + I2C_READ);
	SWAckI2C();
	var = SWReadI2C();
	SWNotAckI2C();
	SWStopI2C();
	
	return var;	
}


int ADresult;
unsigned char CurrentVol;
unsigned char PrevVol;

void
main (void)
{
	char WriteData;
	char currentch;

	int i=0;

	Delay100TCYx(10);

	CurrentVol = 0xFF;
	PrevVol = 0xFF;

	TRISAbits.TRISA2 = 0;
	//MUTE
	PORTAbits.RA2 = 0;
	
	TRISBbits.TRISB0 = 1;
	INTCON2bits.NOT_RBPU = 0;
	

 	//CS8416
	//Serial Audio Format = 1 0 00 0 1 0 1   (I2S 24bit)
	WriteData = 0x85;   //I2S
	I2CWrite(CS8416_ADDRESS, 0x05, WriteData);

 	//Set channel = 1 
 	currentch = 1;
	WriteData = 0x80 + currentch * 8 + currentch;
	I2CWrite(CS8416_ADDRESS, 0x04, WriteData);

	//Setup TAS5076
	//Enable Factory PLL trim
	WriteData = 0x00;
	I2CWrite(TAS5076_ADDRESS, 0x1B, WriteData);

	WriteData = 0x40;	//all channel ON 0000 0000
	I2CWrite(TAS5076_ADDRESS, 0x05, WriteData);
	WriteData = 0x00;	//all channel ON 0000 0000
	I2CWrite(TAS5076_ADDRESS, 0x05, WriteData);

	WriteData = 0xC0;	//set master volume adequate
	I2CWrite(TAS5076_ADDRESS, 0x07, WriteData);

	//UNMUTE
	PORTAbits.RA2 = 1;

	while(1)
	{
		Delay100TCYx(5);
		OpenADC( 0b10100111,
				 0b00000001,
				 0b01111110 );
		Delay100TCYx(5);
		//Read Volume
		ConvertADC();
		while( BusyADC() );
		ADresult = ReadADC();
		CloseADC();
	
		CurrentVol = 0xFF - (ADresult>>2);				
		
		if ((PrevVol < (CurrentVol - 0x03)) || (CurrentVol + 0x03 < PrevVol) )
		{
			WriteData = CurrentVol;	//set master volume adequate
			I2CWrite(TAS5076_ADDRESS, 0x07, WriteData);
			PrevVol = CurrentVol;	//record volume
		}
		
		//Check Opt or Coax
		if (PORTBbits.RB0 == 0) // COAX, 3
		{
			if (currentch == 1)
			{
				currentch = 3;
				WriteData = 0x80 + currentch * 8 + currentch;
				I2CWrite(CS8416_ADDRESS, 0x04, WriteData);
			}
		}
		else	// OPT, 1
		{
			if (currentch == 3)
			{
				currentch = 1;
				WriteData = 0x80 + currentch * 8 + currentch;
				I2CWrite(CS8416_ADDRESS, 0x04, WriteData);
			}			
		}
		
	}
}