SNES multitap support

fournsnes.c

@@ -35,6 +35,11 @@
 #define SNES_DATA_BIT3	(1<<1)	/* controller 3 */
 #define SNES_DATA_BIT4	(1<<0)	/* controller 4 */
 
+#define MULTITAP_SELECT_PORT	PORTB
+#define MULTITAP_SELECT_DDR		DDRB
+#define MULTITAP_SELECT_PIN		PINB
+#define MULTITAP_SELECT_BIT		(1<<5)
+
 /********* IO port manipulation macros **********/
 #define SNES_LATCH_LOW()	do { SNES_LATCH_PORT &= ~(SNES_LATCH_BIT); } while(0)
 #define SNES_LATCH_HIGH()	do { SNES_LATCH_PORT |= SNES_LATCH_BIT; } while(0)
@@ -46,6 +51,9 @@
 #define SNES_GET_DATA3()	(SNES_DATA_PIN & SNES_DATA_BIT3)
 #define SNES_GET_DATA4()	(SNES_DATA_PIN & SNES_DATA_BIT4)
 
+#define MTAP_SELECT_HIGH()	do { MULTITAP_SELECT_PORT |= MULTITAP_SELECT_BIT; } while(0)
+#define MTAP_SELECT_LOW()	do { MULTITAP_SELECT_PORT &= ~MULTITAP_SELECT_BIT; } while(0)
+
 /*********** prototypes *************/
 static void fournsnesInit(void);
 static void fournsnesUpdate(void);
@@ -62,6 +70,7 @@ static unsigned char last_reported_controller_bytes[GAMEPAD_BYTES];
 // indicates if a controller is in NES mode
 static unsigned char nesMode=0;	/* Bit0: controller 1, Bit1: controller 2...*/
 static unsigned char fourscore_mode = 0;
+static unsigned char multitap_mode = 0; // SNES
 static unsigned char live_autodetect = 1;
 
 void disableLiveAutodetect(void)
@@ -69,6 +78,45 @@ void disableLiveAutodetect(void)
 	live_autodetect = 0;
 }
 
+static void autoDetectSNESMultiTap(void)
+{
+	// Detection is done by observing that DATA2 becomes 
+	// low when LATCH is high.
+	//
+	// Not sure which state of MTAP_SELECT_HIGH is reliable
+	// so I'm simply trying with both states.
+
+	MTAP_SELECT_LOW();
+
+	if (SNES_GET_DATA2()) {
+		SNES_LATCH_HIGH();
+		_delay_us(12);
+
+		if (!SNES_GET_DATA2()) {
+			SNES_LATCH_LOW();
+			_delay_us(12);
+			if (SNES_GET_DATA2()) {
+				multitap_mode = 1;
+			}
+		}
+	}
+
+	MTAP_SELECT_HIGH();
+
+	if (SNES_GET_DATA2()) {
+		SNES_LATCH_HIGH();
+		_delay_us(12);
+
+		if (!SNES_GET_DATA2()) {
+			SNES_LATCH_LOW();
+			_delay_us(12);
+			if (SNES_GET_DATA2()) {
+				multitap_mode = 1;
+			}
+		}
+	}
+}
+
 static void autoDetectFourScore(void)
 {
 	unsigned char dat18th_low = 0;
@@ -129,6 +177,11 @@ static void fournsnesInit(void)
 	// LATCH is Active HIGH
 	SNES_LATCH_PORT &= ~(SNES_LATCH_BIT);
 
+	
+	MULTITAP_SELECT_DDR |= MULTITAP_SELECT_BIT;
+	MULTITAP_SELECT_PORT |= MULTITAP_SELECT_BIT;
+
+
 	nesMode = 0;
 	fournsnesUpdate();
 
@@ -160,35 +213,13 @@ static void fournsnesInit(void)
 	}
 
 	autoDetectFourScore();
+	autoDetectSNESMultiTap();
 
 	SREG = sreg;
 }
 
 
-/*
+static void fournsnesUpdate_fourscore(void)
- *
-       Clock Cycle     Button Reported
-        ===========     ===============
-        1               B
-        2               Y
-        3               Select
-        4               Start
-        5               Up on joypad
-        6               Down on joypad
-        7               Left on joypad
-        8               Right on joypad
-        9               A
-        10              X
-        11              L
-        12              R
-        13              none (always high)
-        14              none (always high)
-        15              none (always high)
-        16              none (always high)
- *
- */
-
-static void fournsnesUpdate(void)
 {
 	int i;
 	unsigned char tmp1=0;
@@ -200,8 +231,6 @@ static void fournsnesUpdate(void)
 	_delay_us(12);
 	SNES_LATCH_LOW();
 
-	if (fourscore_mode) 
-	{
 	/* Nes controller buttons are sent in this order:
 	 * One byte: A B SEL START UP DOWN LEFT RIGHT */
 
@@ -249,9 +278,130 @@ static void fournsnesUpdate(void)
 	last_read_controller_bytes[3] = tmp4;
 
 	return;
+
 }
 
 
+/*
+ *
+       Clock Cycle     Button Reported
+        ===========     ===============
+        1               B
+        2               Y
+        3               Select
+        4               Start
+        5               Up on joypad
+        6               Down on joypad
+        7               Left on joypad
+        8               Right on joypad
+        9               A
+        10              X
+        11              L
+        12              R
+        13              none (always high)
+        14              none (always high)
+        15              none (always high)
+        16              none (always high)
+ *
+ */
+
+static void fournsnesUpdate(void)
+{
+	int i;
+	unsigned char tmp1=0;
+	unsigned char tmp2=0;
+	unsigned char tmp3=0;
+	unsigned char tmp4=0;
+
+	if (fourscore_mode) 
+	{
+		fournsnesUpdate_fourscore();
+		return;
+	}
+
+
+	if (multitap_mode) 
+	{
+		SNES_LATCH_HIGH();
+		_delay_us(12);
+		SNES_LATCH_LOW();
+		_delay_us(12);
+
+		MTAP_SELECT_HIGH();
+		_delay_us(6);
+		for (i=0; i<8; i++)
+		{
+			SNES_CLOCK_LOW();
+			_delay_us(6);
+
+			tmp1 <<= 1;	
+			tmp2 <<= 1;	
+
+			if (!SNES_GET_DATA1()) { tmp1 |= 1; }
+			if (!SNES_GET_DATA2()) { tmp2 |= 1; }
+			
+			SNES_CLOCK_HIGH();
+			_delay_us(6);
+		}
+		last_read_controller_bytes[0] = tmp1;
+		last_read_controller_bytes[2] = tmp2;
+		for (i=0; i<8; i++)
+		{
+			SNES_CLOCK_LOW();
+			_delay_us(6);
+
+			tmp1 >>= 1;	
+			tmp2 >>= 1;	
+
+			if (!SNES_GET_DATA1()) { tmp1 |= 0x80; }
+			if (!SNES_GET_DATA2()) { tmp2 |= 0x80; }
+			
+			SNES_CLOCK_HIGH();
+			_delay_us(6);
+		}
+
+
+		MTAP_SELECT_LOW();
+		_delay_us(6);
+		for (i=0; i<8; i++)
+		{
+			SNES_CLOCK_LOW();
+			_delay_us(6);
+
+			tmp3 <<= 1;	
+			tmp4 <<= 1;	
+
+			if (!SNES_GET_DATA1()) { tmp3 |= 1; }
+			if (!SNES_GET_DATA2()) { tmp4 |= 1; }
+			
+			SNES_CLOCK_HIGH();
+			_delay_us(6);
+		}
+		last_read_controller_bytes[4] = tmp3;
+		last_read_controller_bytes[6] = tmp4;
+		for (i=0; i<8; i++)
+		{
+			SNES_CLOCK_LOW();
+			_delay_us(6);
+
+			tmp3 >>= 1;	
+			tmp4 >>= 1;	
+
+			if (!SNES_GET_DATA1()) { tmp3 |= 0x80; }
+			if (!SNES_GET_DATA2()) { tmp4 |= 0x80; }
+			
+			SNES_CLOCK_HIGH();
+			_delay_us(6);
+		}
+
+
+	}
+	else // standard mode (not multitap)
+	{			
+		SNES_LATCH_HIGH();
+		_delay_us(12);
+		SNES_LATCH_LOW();
+
 		for (i=0; i<8; i++)
 		{
 			_delay_us(6);
@@ -294,6 +444,7 @@ static void fournsnesUpdate(void)
 			_delay_us(6);
 			SNES_CLOCK_HIGH();
 		}
+	}
 
 
 	if (live_autodetect) {	

usbconfig.h

@@ -5,7 +5,7 @@
  * Tabsize: 4
  * Copyright: (c) 2005 by OBJECTIVE DEVELOPMENT Software GmbH
  * License: GNU GPL v2 (see License.txt) or proprietary (CommercialLicense.txt)
- * This Revision: $Id: usbconfig.h,v 1.7 2009-05-02 13:55:11 cvs Exp $
+ * This Revision: $Id: usbconfig.h,v 1.8 2012-04-09 04:05:43 cvs Exp $
  */
 
 #ifndef __usbconfig_h_included__
@@ -143,7 +143,7 @@ rename it to "usbconfig.h". Then edit it accordingly.
 #define  USB_CFG_DEVICE_ID       0x9d, 0x0a
 
 
-#define USB_CFG_DEVICE_VERSION  0x02, 0x01
+#define USB_CFG_DEVICE_VERSION  0x03, 0x01
 /* Version number of the device: Minor number first, then major number.
  */
 #define USB_CFG_VENDOR_NAME     'r', 'a', 'p', 'h', 'n', 'e', 't', '.', 'n', 'e', 't'