From b7b07a37eeb64c5a15ccf58e687cdd0934d36094 Mon Sep 17 00:00:00 2001
From: Raphael Assenat <raph@raphnet.net>
Date: Wed, 28 Oct 2015 23:30:26 -0400
Subject: [PATCH] Do away with the gcn64 work buffer (saves more memory!)

---
 gamecube.c       | 25 ++++++++++++-------------
 gcn64_protocol.c | 45 ++++++++++++++-------------------------------
 gcn64_protocol.h |  5 +----
 gcn64txrx.h      |  2 +-
 hiddata.c        |  3 +--
 main.c           |  2 ++
 n64.c            | 28 ++++++++++++++--------------
 7 files changed, 45 insertions(+), 65 deletions(-)

diff --git a/gamecube.c b/gamecube.c
index b9e07b7..e978572 100644
--- a/gamecube.c
+++ b/gamecube.c
@@ -41,7 +41,7 @@ static void gamecubeInit(void)
 	gamecubeUpdate();
 }
 
-void gc_decodeAnswer()
+void gc_decodeAnswer(unsigned char data[8])
 {
 	unsigned char x,y,cx,cy;
 
@@ -87,14 +87,14 @@ void gc_decodeAnswer()
  */
 
 	last_built_report.pad_type = PAD_TYPE_GAMECUBE;
-	last_built_report.gc.buttons = gcn64_protocol_getByte(0) | gcn64_protocol_getByte(8) << 8;
-	x = gcn64_protocol_getByte(16);
-	y = gcn64_protocol_getByte(24);
-	cx = gcn64_protocol_getByte(32);
-	cy = gcn64_protocol_getByte(40);
-	last_built_report.gc.lt = gcn64_protocol_getByte(48);
-	last_built_report.gc.rt = gcn64_protocol_getByte(56);
-	gcn64_protocol_getBytes(0, 8, last_built_report.gc.raw_data);
+	last_built_report.gc.buttons = data[0] | data[1] << 8;
+	x = data[2];
+	y = data[3];
+	cx = data[4];
+	cy = data[5];
+	last_built_report.gc.lt = data[6];
+	last_built_report.gc.rt = data[7];
+	memcpy(last_built_report.gc.raw_data, data, 8);
 
 	if (origins_set) {
 		last_built_report.gc.x = ((int)x-(int)orig_x);
@@ -117,8 +117,7 @@ void gc_decodeAnswer()
 
 static char gamecubeUpdate()
 {
-	//unsigned char tmp=0;
-	unsigned char tmpdata[8];
+	unsigned char tmpdata[GC_GETSTATUS_REPLY_LENGTH];
 	unsigned char count;
 
 #if 0
@@ -147,12 +146,12 @@ static char gamecubeUpdate()
 	tmpdata[1] = GC_GETSTATUS2;
 	tmpdata[2] = GC_GETSTATUS3(gc_rumbling);
 
-	count = gcn64_transaction(tmpdata, 3);
+	count = gcn64_transaction(tmpdata, 3, tmpdata, GC_GETSTATUS_REPLY_LENGTH);
 	if (count != GC_GETSTATUS_REPLY_LENGTH) {
 		return 1;
 	}
 
-	gc_decodeAnswer();
+	gc_decodeAnswer(tmpdata);
 
 	return 0;
 }
diff --git a/gcn64_protocol.c b/gcn64_protocol.c
index 14cec03..ce324ec 100644
--- a/gcn64_protocol.c
+++ b/gcn64_protocol.c
@@ -25,9 +25,6 @@
 
 #undef FORCE_KEYBOARD
 
-#define GCN64_BUF_SIZE	40
-static unsigned char gcn64_workbuf[GCN64_BUF_SIZE];
-
 /******** IO port definitions and options **************/
 #ifndef STK525
 	#define GCN64_DATA_PORT	PORTD
@@ -45,20 +42,6 @@ static unsigned char gcn64_workbuf[GCN64_BUF_SIZE];
 
 #define DISABLE_INTS_DURING_COMM
 
-
-/* Read a byte from the buffer (where 1 byte is 1 bit).
- * MSb first.
- */
-unsigned char gcn64_protocol_getByte(int offset)
-{
-	return gcn64_workbuf[offset/8];
-}
-
-void gcn64_protocol_getBytes(int offset, int n_bytes, unsigned char *dstbuf)
-{
-	memcpy(dstbuf, gcn64_workbuf + offset/8, n_bytes);
-}
-
 void gcn64protocol_hwinit(void)
 {
 	// data as input
@@ -79,22 +62,22 @@ void gcn64protocol_hwinit(void)
  *
  * The result is in gcn64_workbuf.
  */
-int gcn64_transaction(unsigned char *data_out, int data_out_len)
+unsigned char gcn64_transaction(const unsigned char *tx, int tx_len, unsigned char *rx, unsigned char rx_max)
 {
 	int count;
 	unsigned char sreg = SREG;
-//	int i;
+	//int i;
 
 #ifdef DISABLE_INTS_DURING_COMM
 	cli();
 #endif
-	gcn64_sendBytes(data_out, data_out_len);
-	count = gcn64_receiveBytes(gcn64_workbuf, 0);
+	gcn64_sendBytes(tx, tx_len);
+	count = gcn64_receiveBytes(rx, rx_max);
 	SREG = sreg;
 #if 0
 	printf("Count: %d { ", count);
 	for (i=0; i<count; i++) {
-		printf("%02x ", gcn64_workbuf[i]);
+		printf("%02x ", rx[i]);
 	}
 	printf("}\r\n");
 #endif
@@ -123,8 +106,9 @@ int gcn64_detectController(void)
 	unsigned char tmp = GC_GETID;
 	unsigned char count;
 	unsigned short id;
+	unsigned char data[4];
 
-	count = gcn64_transaction(&tmp, 1);
+	count = gcn64_transaction(&tmp, 1, data, sizeof(data));
 	if (count == 0) {
 		return CONTROLLER_IS_ABSENT;
 	}
@@ -132,7 +116,7 @@ int gcn64_detectController(void)
 		return CONTROLLER_IS_UNKNOWN;
 	}
 
-	/* 
+	/*
 	 * -- Standard gamecube controller answer:
 	 * 0000 1001 0000 0000 0010 0011  : 0x090023  or
 	 * 0000 1001 0000 0000 0010 0000  : 0x090020
@@ -145,13 +129,13 @@ int gcn64_detectController(void)
 	 *
 	 * 1110 1001 1010 0000 0001 0111 : 0xE9A017
 	 * (controller on)
-	 * 
+	 *
 	 * 1010 1000 0000
 	 *
 	 * -- Intec wireless gamecube controller
 	 * 0000 1001 0000 0000 0010 0000 : 0x090020
 	 *
-	 * 
+	 *
 	 * -- Standard N64 controller
 	 * 0000 0101 0000 0000 0000 0000 : 0x050000 (no pack)
 	 * 0000 0101 0000 0000 0000 0001 : 0x050001 With expansion pack
@@ -164,8 +148,8 @@ int gcn64_detectController(void)
 	 * gamecube compatible controller is present. If on the other hand
 	 * we have a 5, then we are communicating with a N64 controller.
 	 *
-	 * This conclusion appears to be corroborated by my old printout of 
-	 * the document named "Yet another gamecube documentation (but one 
+	 * This conclusion appears to be corroborated by my old printout of
+	 * the document named "Yet another gamecube documentation (but one
 	 * that's worth printing). The document explains that and ID can
 	 * be read by sending what they call the 'SI command 0x00 to
 	 * which the controller replies with 3 bytes. (Clearly, that's
@@ -186,8 +170,7 @@ int gcn64_detectController(void)
 	 *
 	 * */
 
-	id = gcn64_protocol_getByte(0)<<8;
-	id |= gcn64_protocol_getByte(8);
+	id = (data[0]<<8) | data[1];
 
 #ifdef FORCE_KEYBOARD
 	return CONTROLLER_IS_GC_KEYBOARD;
@@ -209,7 +192,7 @@ int gcn64_detectController(void)
 			// wavebird, controller off.
 			return CONTROLLER_IS_GC;
 
-		default: 
+		default:
 			return CONTROLLER_IS_UNKNOWN;
 	}
 
diff --git a/gcn64_protocol.h b/gcn64_protocol.h
index 23336be..0c3ba24 100644
--- a/gcn64_protocol.h
+++ b/gcn64_protocol.h
@@ -161,9 +161,6 @@
 
 void gcn64protocol_hwinit(void);
 int gcn64_detectController(void);
-int gcn64_transaction(unsigned char *data_out, int data_out_len);
-
-unsigned char gcn64_protocol_getByte(int offset);
-void gcn64_protocol_getBytes(int offset, int n_bytes, unsigned char *dstbuf);
+unsigned char gcn64_transaction(const unsigned char *tx, int tx_len, unsigned char *rx, unsigned char rx_max);
 
 #endif // _gcn64_protocol_h__
diff --git a/gcn64txrx.h b/gcn64txrx.h
index 5bdd53c..a640db0 100644
--- a/gcn64txrx.h
+++ b/gcn64txrx.h
@@ -1,7 +1,7 @@
 #ifndef _gcn64txrx_h__
 #define _gcn64txrx_h__
 
-void gcn64_sendBytes(unsigned char *data, unsigned char n_bytes);
+void gcn64_sendBytes(const unsigned char *data, unsigned char n_bytes);
 
 /**
  * \brief Receive up to \max_bytes bytes
diff --git a/hiddata.c b/hiddata.c
index df36ce5..4f8751a 100644
--- a/hiddata.c
+++ b/hiddata.c
@@ -78,8 +78,7 @@ static void hiddata_processCommandBuffer(void)
 			// TODO : Range checking
 			// cmdbuf[] : RQ, CHN, LEN, data[]
 			channel = cmdbuf[1];
-			cmdbuf_len = gcn64_transaction(cmdbuf+3, cmdbuf[2]);
-			gcn64_protocol_getBytes(0, cmdbuf_len, cmdbuf + 3);
+			cmdbuf_len = gcn64_transaction(cmdbuf+3, cmdbuf[2], cmdbuf + 3, CMDBUF_SIZE-3);
 			cmdbuf[2] = cmdbuf_len;
 			cmdbuf_len += 3; // Answer: RQ, CHN, LEN, data[]
 			break;
diff --git a/main.c b/main.c
index 8db993b..1b9e1b5 100644
--- a/main.c
+++ b/main.c
@@ -222,10 +222,12 @@ Gamepad *detectPad(void)
 			return NULL;
 
 		case CONTROLLER_IS_N64:
+			printf("Detected N64 controller\n");
 			return n64GetGamepad();
 			break;
 
 		case CONTROLLER_IS_GC:
+			printf("Detected GC controller\n");
 			return gamecubeGetGamepad();
 	}
 
diff --git a/n64.c b/n64.c
index 4a04cee..09d455b 100644
--- a/n64.c
+++ b/n64.c
@@ -53,13 +53,14 @@ unsigned char tmpdata[40];
 static char initRumble(void)
 {
 	int count;
+	unsigned char data[4];
 
 	tmpdata[0] = N64_EXPANSION_WRITE;
 	tmpdata[1] = 0x80;
 	tmpdata[2] = 0x01;
 	memset(tmpdata+3, 0x80, 32);
 
-	count = gcn64_transaction(tmpdata, 35);
+	count = gcn64_transaction(tmpdata, 35, data, sizeof(data));
 	if (count == 1)
 		return 0;
 
@@ -69,12 +70,13 @@ static char initRumble(void)
 static char controlRumble(char enable)
 {
 	int count;
+	unsigned char data[4];
 
 	tmpdata[0] = N64_EXPANSION_WRITE;
 	tmpdata[1] = 0xc0;
 	tmpdata[2] = 0x1b;
 	memset(tmpdata+3, enable ? 0x01 : 0x00, 32);
-	count = gcn64_transaction(tmpdata, 35);
+	count = gcn64_transaction(tmpdata, 35, data, sizeof(data));
 	if (count == 1)
 		return 0;
 
@@ -86,7 +88,8 @@ static char n64Update(void)
 	unsigned char count;
 	unsigned char x,y;
 	unsigned char btns1, btns2;
-	unsigned char caps[3];
+	unsigned char caps[N64_CAPS_REPLY_LENGTH];
+	unsigned char status[N64_GET_STATUS_REPLY_LENGTH];
 
 	/* Pad answer to N64_GET_CAPABILITIES
 	 *
@@ -98,7 +101,7 @@ static char n64Update(void)
 	 * Bit 1 tells is if there was something connected that has been removed.
 	 */
 	tmpdata[0] = N64_GET_CAPABILITIES;
-	count = gcn64_transaction(tmpdata, 1);
+	count = gcn64_transaction(tmpdata, 1, caps, sizeof(caps));
 	if (count != N64_CAPS_REPLY_LENGTH) {
 		// a failed read could mean the pack or controller was gone. Init
 		// will be necessary next time we detect a pack is present.
@@ -106,10 +109,6 @@ static char n64Update(void)
 		return -1;
 	}
 
-	caps[0] = gcn64_protocol_getByte(0);
-	caps[1] = gcn64_protocol_getByte(8);
-	caps[2] = gcn64_protocol_getByte(16);
-
 	/* Detect when a pack becomes present and schedule initialisation when it happens. */
 	if ((caps[2] & 0x01) && (n64_rumble_state == RSTATE_UNAVAILABLE)) {
 		n64_rumble_state = RSTATE_INIT;
@@ -173,7 +172,7 @@ static char n64Update(void)
 	}
 
 	tmpdata[0] = N64_GET_STATUS;
-	count = gcn64_transaction(tmpdata, 1);
+	count = gcn64_transaction(tmpdata, 1, status, sizeof(status));
 	if (count != N64_GET_STATUS_REPLY_LENGTH) {
 		return -1;
 	}
@@ -200,10 +199,10 @@ static char n64Update(void)
 	24-31: analog Y axis
  */
 
-	btns1 = gcn64_protocol_getByte(0);
-	btns2 = gcn64_protocol_getByte(8);
-	x = gcn64_protocol_getByte(16); // X axis
-	y = gcn64_protocol_getByte(24); // Y axis
+	btns1 = status[0];
+	btns2 = status[1];
+	x = status[2];
+	y = status[3];
 
 #ifdef BUTTON_A_RUMBLE_TEST
 	if (btns1 & 0x80) {
@@ -256,6 +255,7 @@ static char n64Probe(void)
 	int count;
 	char i;
 	unsigned char tmp;
+	unsigned char data[4];
 
 	/* Pad answer to N64_GET_CAPABILITIES
 	 *
@@ -274,7 +274,7 @@ static char n64Probe(void)
 		_delay_ms(30);
 
 		tmp = N64_GET_CAPABILITIES;
-		count = gcn64_transaction(&tmp, 1);
+		count = gcn64_transaction(&tmp, 1, data, sizeof(data));
 
 		if (count == N64_CAPS_REPLY_LENGTH) {
 			return 1;