From 3a95b30d631fcbce31207d3e7d47924d0a0c1031 Mon Sep 17 00:00:00 2001
From: Vicki Pfau <vi@endrift.com>
Date: Fri, 12 Mar 2021 02:26:43 -0800
Subject: [PATCH] GBA SIO: Improve readability

---
 include/mgba/internal/gba/sio.h |  8 ++++++--
 src/gba/io.c                    |  5 +++--
 src/gba/sio/joybus.c            | 14 +++++++++-----
 3 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/include/mgba/internal/gba/sio.h b/include/mgba/internal/gba/sio.h
index 0f60f8f74..e5656da0c 100644
--- a/include/mgba/internal/gba/sio.h
+++ b/include/mgba/internal/gba/sio.h
@@ -29,8 +29,12 @@ enum {
 	JOY_CMD_TRANS = 0x14,
 	JOY_CMD_RECV = 0x15,
 
-	JOYSTAT_TRANS_BIT = 8,
-	JOYSTAT_RECV_BIT = 2,
+	JOYSTAT_TRANS = 8,
+	JOYSTAT_RECV = 2,
+
+	JOYCNT_RESET = 1,
+	JOYCNT_RECV = 2,
+	JOYCNT_TRANS = 4,
 };
 
 DECL_BITFIELD(GBASIONormal, uint16_t);
diff --git a/src/gba/io.c b/src/gba/io.c
index ea2e1dc8d..8088af38e 100644
--- a/src/gba/io.c
+++ b/src/gba/io.c
@@ -532,7 +532,7 @@ void GBAIOWrite(struct GBA* gba, uint32_t address, uint16_t value) {
 		break;
 	case REG_JOY_TRANS_LO:
 	case REG_JOY_TRANS_HI:
-		gba->memory.io[REG_JOYSTAT >> 1] |= JOYSTAT_TRANS_BIT;
+		gba->memory.io[REG_JOYSTAT >> 1] |= JOYSTAT_TRANS;
 		// Fall through
 	case REG_SIODATA32_LO:
 	case REG_SIODATA32_HI:
@@ -576,6 +576,7 @@ void GBAIOWrite(struct GBA* gba, uint32_t address, uint16_t value) {
 	case REG_DEBUG_FLAGS:
 		if (gba->debug) {
 			GBADebug(gba, value);
+
 			return;
 		}
 		// Fall through
@@ -835,7 +836,7 @@ uint16_t GBAIORead(struct GBA* gba, uint32_t address) {
 
 	case REG_JOY_RECV_LO:
 	case REG_JOY_RECV_HI:
-		gba->memory.io[REG_JOYSTAT >> 1] &= ~JOYSTAT_RECV_BIT;
+		gba->memory.io[REG_JOYSTAT >> 1] &= ~JOYSTAT_RECV;
 		break;
 
 	case REG_SOUNDBIAS:
diff --git a/src/gba/sio/joybus.c b/src/gba/sio/joybus.c
index 3b6a7111b..c5a339883 100644
--- a/src/gba/sio/joybus.c
+++ b/src/gba/sio/joybus.c
@@ -31,7 +31,7 @@ uint16_t GBASIOJOYWriteRegister(struct GBASIODriver* sio, uint32_t address, uint
 int GBASIOJOYSendCommand(struct GBASIODriver* sio, enum GBASIOJOYCommand command, uint8_t* data) {
 	switch (command) {
 	case JOY_RESET:
-		sio->p->p->memory.io[REG_JOYCNT >> 1] |= 1;
+		sio->p->p->memory.io[REG_JOYCNT >> 1] |= JOYCNT_RESET;
 		if (sio->p->p->memory.io[REG_JOYCNT >> 1] & 0x40) {
 			GBARaiseIRQ(sio->p->p, IRQ_SIO, 0);
 		}
@@ -40,16 +40,18 @@ int GBASIOJOYSendCommand(struct GBASIODriver* sio, enum GBASIOJOYCommand command
 		data[0] = 0x00;
 		data[1] = 0x04;
 		data[2] = sio->p->p->memory.io[REG_JOYSTAT >> 1];
+
 		mLOG(GBA_SIO, DEBUG, "JOY %s: %02X (%02X)", command == JOY_POLL ? "poll" : "reset", data[2], sio->p->p->memory.io[REG_JOYCNT >> 1]);
 		return 3;
 	case JOY_RECV:
-		sio->p->p->memory.io[REG_JOYCNT >> 1] |= 2;
-		sio->p->p->memory.io[REG_JOYSTAT >> 1] |= 2;
+		sio->p->p->memory.io[REG_JOYCNT >> 1] |= JOYCNT_RECV;
+		sio->p->p->memory.io[REG_JOYSTAT >> 1] |= JOYSTAT_RECV;
 
 		sio->p->p->memory.io[REG_JOY_RECV_LO >> 1] = data[0] | (data[1] << 8);
 		sio->p->p->memory.io[REG_JOY_RECV_HI >> 1] = data[2] | (data[3] << 8);
 
 		data[0] = sio->p->p->memory.io[REG_JOYSTAT >> 1];
+
 		mLOG(GBA_SIO, DEBUG, "JOY recv: %02X (%02X)", data[0], sio->p->p->memory.io[REG_JOYCNT >> 1]);
 
 		if (sio->p->p->memory.io[REG_JOYCNT >> 1] & 0x40) {
@@ -57,13 +59,15 @@ int GBASIOJOYSendCommand(struct GBASIODriver* sio, enum GBASIOJOYCommand command
 		}
 		return 1;
 	case JOY_TRANS:
-		sio->p->p->memory.io[REG_JOYCNT >> 1] |= 4;
-		sio->p->p->memory.io[REG_JOYSTAT >> 1] &= ~JOYSTAT_TRANS_BIT;
+		sio->p->p->memory.io[REG_JOYCNT >> 1] |= JOYCNT_TRANS;
+		sio->p->p->memory.io[REG_JOYSTAT >> 1] &= ~JOYSTAT_TRANS;
+
 		data[0] = sio->p->p->memory.io[REG_JOY_TRANS_LO >> 1];
 		data[1] = sio->p->p->memory.io[REG_JOY_TRANS_LO >> 1] >> 8;
 		data[2] = sio->p->p->memory.io[REG_JOY_TRANS_HI >> 1];
 		data[3] = sio->p->p->memory.io[REG_JOY_TRANS_HI >> 1] >> 8;
 		data[4] = sio->p->p->memory.io[REG_JOYSTAT >> 1];
+
 		mLOG(GBA_SIO, DEBUG, "JOY trans: %02X%02X%02X%02X:%02X (%02X)", data[0], data[1], data[2], data[3], data[4], sio->p->p->memory.io[REG_JOYCNT >> 1]);
 
 		if (sio->p->p->memory.io[REG_JOYCNT >> 1] & 0x40) {