4nes4snes/main.c

/* Name: main.c
 * Project: Multiple NES/SNES to USB converter
 * Author: Raphael Assenat <raph@raphnet.net>
 * Copyright: (C) 2007 Raphael Assenat <raph@raphnet.net>
 * License: Proprietary, free under certain conditions. See Documentation.
 * Tabsize: 4
 * Comments: Based on HID-Test by Christian Starkjohann
 */

#define F_CPU   12000000L  

#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/pgmspace.h>
#include <avr/wdt.h>
#include <util/delay.h>
#include <string.h>

#include "usbdrv.h"
#include "oddebug.h"
#include "gamepad.h"

#include "snes.h"

#include "leds.h"
#include "devdesc.h"

/* The maximum number of independent reports that are supported. */
#define MAX_REPORTS 8	

int usbCfgSerialNumberStringDescriptor[] PROGMEM = {
 	USB_STRING_DESCRIPTOR_HEADER(USB_CFG_SERIAL_NUMBER_LENGTH),
 	'1', '0', '0', '0'
 };

static Gamepad *curGamepad;


/* ----------------------- hardware I/O abstraction ------------------------ */

static void hardwareInit(void)
{
	uchar	i, j;

	// init port C as input with pullup
	DDRC = 0x00;
	PORTC = 0xff;
	
	/* 1101 1000 bin: activate pull-ups except on USB lines 
	 *
	 * USB signals are on bit 0 and 2. 
	 *
	 * Bit 1 is connected with bit 0 (rev.C pcb error), so the pullup
	 * is not enabled.
	 * */
	PORTD = 0xf8;   

	/* Usb pin are init as outputs */
	DDRD = 0x01 | 0x04;    

	
	j = 0;
	while(--j){     /* USB Reset by device only required on Watchdog Reset */
		i = 0;
		while(--i); /* delay >10ms for USB reset */
	}
	DDRD = 0x00;    /* 0000 0000 bin: remove USB reset condition */
			/* configure timer 0 for a rate of 12M/(1024 * 256) = 45.78 Hz (~22ms) */
	TCCR0 = 5;      /* timer 0 prescaler: 1024 */

	TCCR2 = (1<<WGM21)|(1<<CS22)|(1<<CS21)|(1<<CS20);
	OCR2 = 196; // for 60 hz

}

static uchar    reportBuffer[12];    /* buffer for HID reports */



/* ------------------------------------------------------------------------- */
/* ----------------------------- USB interface ----------------------------- */
/* ------------------------------------------------------------------------- */

static uchar    idleRates[MAX_REPORTS];           /* in 4 ms units */

static uchar reportPos=0;

uchar	usbFunctionSetup(uchar data[8])
{
	usbRequest_t    *rq = (void *)data;
	int i;

	usbMsgPtr = reportBuffer;

	/* class request type */
	if((rq->bmRequestType & USBRQ_TYPE_MASK) == USBRQ_TYPE_CLASS){    
		switch (rq->bRequest)
		{
			case USBRQ_HID_GET_REPORT:
				/* wValue: ReportType (highbyte), ReportID (lowbyte) */
				reportPos=0;
				return curGamepad->buildReport(reportBuffer, rq->wValue.bytes[0]);
			
			case USBRQ_HID_GET_IDLE:
				if (rq->wValue.bytes[0] > 0 && rq->wValue.bytes[0] <= MAX_REPORTS) {
					usbMsgPtr = idleRates + (rq->wValue.bytes[0] - 1);
					return 1;
				}
				break;			
			
			case USBRQ_HID_SET_IDLE:
				if (rq->wValue.bytes[0]==0) {
					for (i=0; i<MAX_REPORTS; i++)
						idleRates[i] = rq->wValue.bytes[1];	
				}
				else {
					if (rq->wValue.bytes[0] > 0 && rq->wValue.bytes[0] <= MAX_REPORTS) {
						idleRates[rq->wValue.bytes[0]-1] = rq->wValue.bytes[1];
					}
				}
				break;
		}
	} else {
		/* no vendor specific requests implemented */
	}
	return 0;
}

/* ------------------------------------------------------------------------- */

int main(void)
{
	char must_report = 0;	/* bitfield */
	uchar   idleCounters[MAX_REPORTS];
	int i;

	memset(idleCounters, 0, MAX_REPORTS);

	curGamepad = snesGetGamepad();

	// configure report descriptor according to
	// the current gamepad
	rt_usbHidReportDescriptor = curGamepad->reportDescriptor;
	rt_usbHidReportDescriptorSize = curGamepad->reportDescriptorSize;

	if (curGamepad->deviceDescriptor != 0)
	{
		rt_usbDeviceDescriptor = (void*)curGamepad->deviceDescriptor;
		rt_usbDeviceDescriptorSize = curGamepad->deviceDescriptorSize;
	}
	else
	{
		// use descriptor from devdesc.c
		//
		rt_usbDeviceDescriptor = (void*)usbDescrDevice;
		rt_usbDeviceDescriptorSize = getUsbDescrDevice_size();
	}

	//wdt_enable(WDTO_2S);
	hardwareInit();
	curGamepad->init();
	odDebugInit();
	usbInit();

	curGamepad->update();

	sei();
	DBG1(0x00, 0, 0);

	
	for(;;){	/* main event loop */
		wdt_reset();

		// this must be called at each 50 ms or less
		usbPoll();

		/* Read the controllers at 60hz */
		if (TIFR & (1<<OCF2))
		{
			TIFR = 1<<OCF2;
				
			curGamepad->update();

			/* Check what will have to be reported */
			for (i=0; i<curGamepad->num_reports; i++) {
				if (curGamepad->changed(i+1)) {
					must_report |= (1<<i);
				}
			}
		}

		/* Try to report at the granularity requested by
		 * the host. */
		if (TIFR & (1<<TOV0)) {   /* 22 ms timer */
			TIFR = 1<<TOV0;

			for (i=0; i<curGamepad->num_reports; i++)
			{
				// 0 means 
				if(idleRates[i] != 0){
					if (idleCounters[i] > 4) {
						idleCounters[i] -= 5;   /* 22 ms in units of 4 ms */
					} else {
						// reset the counter and schedule a report for this
						idleCounters[i] = idleRates[i];
						must_report |= (1<<i);
					}
				}
			}
		}

	
			
		if(must_report)
		{
			for (i = 0; i < curGamepad->num_reports; i++)
			{
				if ((must_report & (1<<i)) == 0) 
					continue;

				if (usbInterruptIsReady())
				{ 	
					char len;

					len = curGamepad->buildReport(reportBuffer, i+1);
					usbSetInterrupt(reportBuffer, len);

					while (!usbInterruptIsReady())
					{
						usbPoll();
						wdt_reset();
					}
				}
			}

			must_report = 0;
		}
	}
	return 0;
}

/* ------------------------------------------------------------------------- */