main.c

/* Dreamcast to USB : Sega dc controllers to USB adapter
 * Copyright (C) 2013 Raphaël Assénat
 *
 * 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 2 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, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * The author may be contacted at raph@raphnet.net
 */
#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/pgmspace.h>
#include <avr/wdt.h>
#include <avr/sleep.h>
#include <util/delay.h>
#include <string.h>

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

#include "dc_pad.h"

static usbMsgPtr_t rt_usbHidReportDescriptor = USB_NO_MSG;
static usbMsgLen_t rt_usbHidReportDescriptorSize = 0;

static usbMsgPtr_t rt_usbDeviceDescriptor = USB_NO_MSG;
static usbMsgLen_t rt_usbDeviceDescriptorSize = 0;

#if defined(__AVR_ATmega168__) || defined(__AVR_ATmega168A__) || \
	defined(__AVR_ATmega168P__) || defined(__AVR_ATmega328__) || \
	defined(__AVR_ATmega328P__) || defined(__AVR_ATmega88__) || \
	defined(__AVR_ATmega88A__) || defined(__AVR_ATmega88P__) || \
	defined(__AVR_ATmega88PA__)
#define AT168_COMPATIBLE
#endif



const PROGMEM int usbDescriptorStringSerialNumber[]  = {
 	USB_STRING_DESCRIPTOR_HEADER(4),
	'1','0','0','0'
};

char usbDescriptorConfiguration[] = { 0 }; // dummy

uchar my_usbDescriptorConfiguration[] = {    /* USB configuration descriptor */
    9,          /* sizeof(usbDescriptorConfiguration): length of descriptor in bytes */
    USBDESCR_CONFIG,    /* descriptor type */
    18 + 7 * USB_CFG_HAVE_INTRIN_ENDPOINT + 9, 0,
                /* total length of data returned (including inlined descriptors) */
    1,          /* number of interfaces in this configuration */
    1,          /* index of this configuration */
    0,          /* configuration name string index */
#if USB_CFG_IS_SELF_POWERED
    USBATTR_SELFPOWER,  /* attributes */
#else
    USBATTR_BUSPOWER,   /* attributes */
#endif
    USB_CFG_MAX_BUS_POWER/2,            /* max USB current in 2mA units */
/* interface descriptor follows inline: */
    9,          /* sizeof(usbDescrInterface): length of descriptor in bytes */
    USBDESCR_INTERFACE, /* descriptor type */
    0,          /* index of this interface */
    0,          /* alternate setting for this interface */
    USB_CFG_HAVE_INTRIN_ENDPOINT,   /* endpoints excl 0: number of endpoint descriptors to follow */
    USB_CFG_INTERFACE_CLASS,
    USB_CFG_INTERFACE_SUBCLASS,
    USB_CFG_INTERFACE_PROTOCOL,
    0,          /* string index for interface */
//#if (USB_CFG_DESCR_PROPS_HID & 0xff)    /* HID descriptor */
    9,          /* sizeof(usbDescrHID): length of descriptor in bytes */
    USBDESCR_HID,   /* descriptor type: HID */
    0x01, 0x01, /* BCD representation of HID version */
/* 22 */    15,       /* target country code : 15 = Japan */ 
/* 23 */    0x01,       /* number of HID Report (or other HID class) Descriptor infos to follow */
/* 24 */    0x22,       /* descriptor type: report */
/* 25 */    USB_CFG_HID_REPORT_DESCRIPTOR_LENGTH, 0,  /* total length of report descriptor */
//#endif
#if USB_CFG_HAVE_INTRIN_ENDPOINT    /* endpoint descriptor for endpoint 1 */
    7,          /* sizeof(usbDescrEndpoint) */
    USBDESCR_ENDPOINT,  /* descriptor type = endpoint */
    0x81,       /* IN endpoint number 1 */
    0x03,       /* attrib: Interrupt endpoint */
    8, 0,       /* maximum packet size */
    USB_CFG_INTR_POLL_INTERVAL, /* in ms */
#endif
};

static Gamepad *curGamepad;


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

static void hardwareInit(void)
{
	/* PORTB
	 * 
	 * Bit     Description       Direction    Level/pu 
	 * 0       Jumpers common    Out          0
	 * 1       JP1               In           1
	 * 2       JP2               In           1
	 * 3       MOSI              In           1
	 * 4       MISO              In           1
	 * 5       SCK               In           1
	 * 6       -
	 * 7       -
	 */
	DDRB = 0x01;
	PORTB = 0xFE;

	// temporaty debug pin PB4
	DDRB |= 0x10;


	/*
	 * PORTC
	 *
	 * Bit 
	 * 0        Pin 1
	 * 1        Pin 5
	 */
	DDRC = 0x00;
	PORTC = 0xff;

	/*
	 * For port D, activate pull-ups on all lines except the D+, D- and bit 1.
	 *
	 * For historical reasons (a mistake on an old PCB), bit 1
	 * is now always connected with bit 0. So bit 1 configured
	 * as an input without pullup.
	 *
	 * Usb pin are init as output, low. (device reset). They are released
	 * later when usbReset() is called.
	 */
	PORTD = 0xf8;
	DDRD = 0x01 | 0x04;    

	/* Configure timers */	
#if defined(AT168_COMPATIBLE)
	TCCR2A= (1<<WGM21);
	TCCR2B=(1<<CS22)|(1<<CS21)|(1<<CS20);
//	OCR2A=196;  // for 60 hz
	OCR2A=50;  // for 60 hz
#else
	TCCR2 = (1<<WGM21)|(1<<CS22)|(1<<CS21)|(1<<CS20);
	//OCR2 = 196; // for 60 hz
	OCR2 = 50; // for 60 hz
#endif
}

#if defined(AT168_COMPATIBLE)

#define mustPollControllers()	(TIFR2 & (1<<OCF2A))
#define clrPollControllers()	do { TIFR2 = 1<<OCF2A; } while(0)

#else

#define mustPollControllers()	(TIFR & (1<<OCF2))
#define clrPollControllers()	do { TIFR = 1<<OCF2; } while(0)

#endif




static void usbReset(void)
{
	/* [...] a single ended zero or SE0 can be used to signify a device 
	   reset if held for more than 10mS. A SE0 is generated by holding 
       both th D- and D+ low (< 0.3V). 
	*/
	
	PORTD &= ~(0x01 | 0x04); // Set D+ and D- to 0
	DDRD |= 0x01 | 0x04;    
	_delay_ms(15);
	DDRD &= ~(0x01 | 0x04);
}

static uchar    reportBuffer[16];    /* buffer for HID reports */

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


usbMsgLen_t usbFunctionDescriptor(struct usbRequest *rq)
{
	if ((rq->bmRequestType & USBRQ_TYPE_MASK) != USBRQ_TYPE_STANDARD)
		return 0;

	if (rq->bRequest == USBRQ_GET_DESCRIPTOR)
	{
		// USB spec 9.4.3, high byte is descriptor type
		switch (rq->wValue.bytes[1])
		{
			case USBDESCR_DEVICE:
				usbMsgPtr = rt_usbDeviceDescriptor;		
				return rt_usbDeviceDescriptorSize;
			case USBDESCR_HID_REPORT:
				usbMsgPtr = rt_usbHidReportDescriptor;
				return rt_usbHidReportDescriptorSize;
			case USBDESCR_CONFIG:
				usbMsgPtr = (usbMsgPtr_t)my_usbDescriptorConfiguration;
				return sizeof(my_usbDescriptorConfiguration);
		}
	}

	return 0;
}

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

	usbMsgPtr = (usbMsgPtr_t)reportBuffer;
	if((rq->bmRequestType & USBRQ_TYPE_MASK) == USBRQ_TYPE_CLASS){    /* class request type */
		if(rq->bRequest == USBRQ_HID_GET_REPORT){  /* wValue: ReportType (highbyte), ReportID (lowbyte) */
			return curGamepad->buildReport(reportBuffer, rq->wValue.bytes[0]);
		}
	}else{
		/* no vendor specific requests implemented */
	}
	return 0;
}

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


int main(void)
{
	char must_report = 0;
	int i;

	hardwareInit();

	curGamepad = dcGetGamepad();
	curGamepad->init();

reconnect:
	// configure report descriptor according to
	// the current gamepad
	rt_usbHidReportDescriptor = (usbMsgPtr_t)curGamepad->reportDescriptor;
	rt_usbHidReportDescriptorSize = curGamepad->reportDescriptorSize;
	rt_usbDeviceDescriptor = (usbMsgPtr_t)curGamepad->deviceDescriptor;
	rt_usbDeviceDescriptorSize = curGamepad->deviceDescriptorSize;

	// patch the config descriptor with the HID report descriptor size
	my_usbDescriptorConfiguration[25] = rt_usbHidReportDescriptorSize;

	usbReset();
	usbInit();
	set_sleep_mode(SLEEP_MODE_IDLE);
	sei();
	
	for(;;){	/* main event loop */
		wdt_reset();

		if (curGamepad->descriptorsChanged && curGamepad->descriptorsChanged()) {
			goto reconnect;
		}

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

		if (mustPollControllers())
		{
			clrPollControllers();

			sleep_enable();
			sleep_cpu();
			sleep_disable();
			_delay_us(100);
				
			curGamepad->update();

			for (i=0; i<curGamepad->num_reports; i++) {			
				if (curGamepad->changed(i+1)) {
					must_report |= (1<<i);
				}
			}
			
		}
			
		if(must_report)
		{
			for (i=0; i<curGamepad->num_reports; i++) {
				int len;

				if (!(must_report & (1<<i)))
					continue;

				len = curGamepad->buildReport(reportBuffer, i+1);
				while(!usbInterruptIsReady()) {
					usbPoll();
				}
				usbSetInterrupt(reportBuffer, len);
				must_report &= ~(1<<i);
			}
			
		}
	}
	return 0;
}

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