/*******************************************************************
 *	Playstation USB Controller Program for Devasys EZ-USB Board
 *	
 *	This program simulates the Playstation host and recieves a signal
 *	from the Playstation controller representative of the current
 *  state of the buttons.  This code will read this value and place it
 * 	in a buffer to be read by a USB interrupt and transmitted to the
 *  computer.
 *
 *	Code written by Frederick N. Genthner & Patrick T. Phelan
 *
 *	Group: "Rokken Like Dokken"
 *
 *******************************************************************/

/*******************************************************************
 *
 *	Pin Description
 *
 *	Port B
 *	OUTB 4:
 *	OUTB 5:
 *	OUTB 6: DATA
 *	OUTB 7: ACK
 *
 *	Port A
 *	OUTA 4:
 *	OUTA 5: CMD
 *	OUTA 6: CLK
 *	OUTA 7: ATT
 *
 *******************************************************************/

#include <ezusb.h>
#include <ezregs.h>

#define CYCLECMD1 OUTA=0x30; OUTA=0x30; OUTA=0x70; OUTA=0x70;
#define CYCLECMD0 OUTA=0x10; OUTA=0x10; OUTA=0x50; OUTA=0x50;

/* Define global variables for PlayStation Controller Communication/Operation */
static unsigned timer0_tick;        // timer tick variable
BYTE t=0;
BYTE ps_count=0;
BYTE THIGH=0x00;
BYTE TLOW=0x00;
BYTE L1=0;
BYTE L2=0;
BYTE R1=0;
BYTE R2=0;
BYTE SQA=0;
BYTE CIR=0;
BYTE TRI=0;
BYTE X=0;
BYTE START=0;
BYTE SELECT=0;
BYTE UP=0;
BYTE DOWN=0;
BYTE LEFT=0;
BYTE RIGHT=0;

/*************************************************************
 *
 *	do_cmd(BYTE b) - Communicates w/ Playstation controller and
 *		stores data from button presses for later use
 *
 *	Parameters - BYTE b - case statement switch value
 *
 *  Return - void
 *
 *************************************************************/
void do_cmd(BYTE b) {
	switch(b) {
		case 1:
			CYCLECMD1	// CYCLE 1 CMD = 1
			CYCLECMD0	// CYCLE 1 CMD = 0
			CYCLECMD0	// CYCLE 1 CMD = 0
			CYCLECMD0	// CYCLE 1 CMD = 0

			CYCLECMD0	// CYCLE 1 CMD = 0
			CYCLECMD0	// CYCLE 1 CMD = 0
			CYCLECMD0	// CYCLE 1 CMD = 0
			CYCLECMD0	// CYCLE 1 CMD = 0
			
			OUTA = 0x70;	// idle high
			break;
		case 2:
			CYCLECMD0	// CYCLE 2 CMD = 0
			CYCLECMD1   // CYCLE 2 CMD = 1
			CYCLECMD0	// CYCLE 2 CMD = 0
			CYCLECMD0	// CYCLE 2 CMD = 0

			CYCLECMD0	// CYCLE 2 CMD = 0
			CYCLECMD0	// CYCLE 2 CMD = 0
			CYCLECMD1   // CYCLE 2 CMD = 1
			CYCLECMD0	// CYCLE 2 CMD = 0
			
			OUTA = 0x70;	// idle high
			break;
		case 3:
			CYCLECMD0	// CYCLE 3 CMD = 0
			CYCLECMD0	// CYCLE 3 CMD = 0
			CYCLECMD0	// CYCLE 3 CMD = 0
			CYCLECMD0	// CYCLE 3 CMD = 0

			CYCLECMD0	// CYCLE 3 CMD = 0
			CYCLECMD0	// CYCLE 3 CMD = 0
			CYCLECMD0	// CYCLE 3 CMD = 0
			CYCLECMD0	// CYCLE 3 CMD = 0

			OUTA = 0x70;	// idle high
			break;
		case 4:
			OUTA=0x10; OUTA=0x10; OUTA=0x50; SELECT=PINSB;
			OUTA=0x10; OUTA=0x10; OUTA=0x50; OUTA=0x50;
			OUTA=0x10; OUTA=0x10; OUTA=0x50; OUTA=0x50;
			OUTA=0x10; OUTA=0x10; OUTA=0x50; START=PINSB;

			OUTA=0x10; OUTA=0x10; OUTA=0x50; UP=PINSB;
			OUTA=0x10; OUTA=0x10; OUTA=0x50; RIGHT=PINSB;
			OUTA=0x10; OUTA=0x10; OUTA=0x50; DOWN=PINSB;
			OUTA=0x10; OUTA=0x10; OUTA=0x50; LEFT=PINSB;
			//////////////////////////
			OUTA = 0x70;			// idle high
			break;
		case 5:
			OUTA=0x10; OUTA=0x10; OUTA=0x50; L2=PINSB;
			OUTA=0x10; OUTA=0x10; OUTA=0x50; R2=PINSB;
			OUTA=0x10; OUTA=0x10; OUTA=0x50; L1=PINSB;
			OUTA=0x10; OUTA=0x10; OUTA=0x50; R1=PINSB;

			OUTA=0x10; OUTA=0x10; OUTA=0x50; TRI=PINSB;
			OUTA=0x10; OUTA=0x10; OUTA=0x50; CIR=PINSB;
			OUTA=0x10; OUTA=0x10; OUTA=0x50; X=PINSB;
			OUTA=0x10; OUTA=0x10; OUTA=0x50; SQA=PINSB;

			//////////////////////////
			OUTA = 0x70;			// idle high
			break;
	} // End switch(b)
} // End do_cmd(BYTE b)


/*************************************************************
 *
 *	timer0(void) - Interrupt to call do_cmd() function for 
 *  	PlayStation communication.
 *
 *	Parameters - void
 *
 *  Return - void
 *
 *************************************************************/
void timer0 (void) interrupt 1 using 1 {
	BYTE i;
	EA = 0;		// disable interrupts
	TR0 = 0;    // stop timer
	
	OUTA = 0x70;	// pull ATT low to communicate with psx controller
	i=0;
	for(i=0;i<30;i++) {}
	
	do_cmd(1);
	for(i=0;i<30;i++) {}
	do_cmd(2);
	for(i=0;i<30;i++) {}
	do_cmd(3);
	for(i=0;i<30;i++) {}
	do_cmd(4);
	for(i=0;i<30;i++) {}
	do_cmd(5);
	for(i=0;i<30;i++) {}

	//test_buttons();

	
	OUTA = 0xF0;		// all signals idle high
	TL0 = TL0 + TLOW;	// reset timer counter value
	TH0 = TH0 + THIGH;	// reset timer counter value

	TR0 = 1;		// start Timer 0
	EA = 1;			// enable interrupts
} // End timer0 interrupt


/*************************************************************
 *
 *	timer0_init(void) - Initializes timer0 interrupt.
 *
 *	Parameters - void
 *
 *  Return - void
 *
 *************************************************************/
void timer0_init (void) {
	EA = 0; 													// disables all interrupts
	TR0 = 0;                									// stops Timer 0
	CKCON = 0x03;												// Timer 0 using CLK24/12
	TMOD &= ~0x0F;												// clear Timer 0 mode bits
	TMOD |= 0x01;                   							// setup Timer 0 as a 16-bit timer
	TL0 = TL0 + THIGH;										// set low byte of counter
	TH0 = TH0 + TLOW;										// set high byte of counter
	PT0 = 0;													// sets the Timer 0 interrupt to low priority
	ET0 = 1;													// enables Timer 0 interrupt
	TR0 = 1;                       								// starts Timer 0
	EA =  1;                									// enables all interrupts
} // End timer0_init