Fill out SIO driver infrastructure

src/gba/gba-sio.c

@@ -2,14 +2,34 @@
 
 #include "gba-io.h"
 
+static struct GBASIODriver* _lookupDriver(struct GBASIO* sio, enum GBASIOMode mode) {
+	switch (mode) {
+	case SIO_MULTI:
+		return sio->drivers.multiplayer;
+	case SIO_JOYBUS:
+		return sio->drivers.joybus;
+	default:
+		return 0;
+	}
+}
+
 static void _switchMode(struct GBASIO* sio) {
 	int mode = ((sio->rcnt >> 14) & 0xC) | ((sio->siocnt >> 12) & 0x3);
+	enum GBASIOMode oldMode = sio->mode;
 	if (mode < 8) {
 		sio->mode = (enum GBASIOMode) (mode & 0x3);
 	} else {
 		sio->mode = (enum GBASIOMode) (mode & 0xC);
 	}
-	// TODO: hangup if we have an existing connection
+	if (oldMode != mode) {
+		if (sio->activeDriver && sio->activeDriver->detach) {
+			sio->activeDriver->detach(sio->activeDriver);
+		}
+		sio->activeDriver = _lookupDriver(sio, mode);
+		if (sio->activeDriver && sio->activeDriver->attach) {
+			sio->activeDriver->attach(sio->activeDriver);
+		}
+	}
 }
 
 void GBASIOInit(struct GBASIO* sio) {
@@ -18,12 +38,63 @@ void GBASIOInit(struct GBASIO* sio) {
 	_switchMode(sio);
 }
 
+void GBASIOSetDriverSet(struct GBASIO* sio, struct GBASIODriverSet* drivers) {
+	if (drivers->multiplayer) {
+		GBASIOSetDriver(sio, drivers->multiplayer, SIO_MULTI);
+	}
+	if (drivers->joybus) {
+		GBASIOSetDriver(sio, drivers->multiplayer, SIO_JOYBUS);
+	}
+}
+
+void GBASIOSetDriver(struct GBASIO* sio, struct GBASIODriver* driver, enum GBASIOMode mode) {
+	struct GBASIODriver** driverLoc;
+	switch (mode) {
+	case SIO_MULTI:
+		driverLoc = &sio->drivers.multiplayer;
+		break;
+	case SIO_JOYBUS:
+		driverLoc = &sio->drivers.joybus;
+		break;
+	default:
+		GBALog(sio->p, GBA_LOG_ERROR, "Setting an unsupported SIO driver: %x", mode);
+		return;
+	}
+	if (*driverLoc) {
+		if ((*driverLoc)->detach) {
+			(*driverLoc)->detach(*driverLoc);
+		}
+		if ((*driverLoc)->deinit) {
+			(*driverLoc)->deinit(*driverLoc);
+		}
+	}
+	if (*driverLoc == sio->activeDriver) {
+		sio->activeDriver = driver;
+	}
+	*driverLoc = driver;
+	if (driver && driver->init) {
+		driver->init(driver, sio);
+	}
+}
+
 void GBASIOWriteRCNT(struct GBASIO* sio, uint16_t value) {
 	sio->rcnt = value;
 	_switchMode(sio);
+	if (sio->activeDriver && sio->activeDriver->writeRegister) {
+		sio->activeDriver->writeRegister(sio->activeDriver, REG_RCNT, value);
+	}
 }
 
 void GBASIOWriteSIOCNT(struct GBASIO* sio, uint16_t value) {
 	sio->siocnt = value;
 	_switchMode(sio);
+	if (sio->activeDriver && sio->activeDriver->writeRegister) {
+		sio->activeDriver->writeRegister(sio->activeDriver, REG_SIOCNT, value);
+	}
+}
+
+void GBASIOWriteSIOMLT_SEND(struct GBASIO* sio, uint16_t value) {
+	if (sio->activeDriver && sio->activeDriver->writeRegister) {
+		sio->activeDriver->writeRegister(sio->activeDriver, REG_SIOMLT_SEND, value);
+	}
 }

src/gba/gba-sio.h

@@ -12,24 +12,32 @@ enum GBASIOMode {
 	SIO_JOYBUS = 12
 };
 
-enum GBASIOMultiMode {
-	VBA_LINK_COMPAT
-};
-
 enum {
 	RCNT_INITIAL = 0x8000
 };
 
+struct GBASIO;
+
 struct GBASIODriver {
+	void (*init)(struct GBASIODriver* driver, struct GBASIO* sio);
+	void (*deinit)(struct GBASIODriver* driver);
+
 	int (*attach)(struct GBASIODriver* driver);
+	int (*detach)(struct GBASIODriver* driver);
+	void (*writeRegister)(struct GBASIODriver* driver, uint32_t address, uint16_t value);
+};
+
+struct GBASIODriverSet {
+	struct GBASIODriver* multiplayer;
+	struct GBASIODriver* joybus;
 };
 
 struct GBASIO {
 	struct GBA* p;
 
 	enum GBASIOMode mode;
-	enum GBASIOMultiMode multiMode;
+	struct GBASIODriverSet drivers;
-	struct GBASIODriver* driver;
+	struct GBASIODriver* activeDriver;
 
 	uint16_t rcnt;
 	union {
@@ -64,6 +72,8 @@ struct GBASIO {
 };
 
 void GBASIOInit(struct GBASIO* sio);
+void GBASIOSetDriverSet(struct GBASIO* sio, struct GBASIODriverSet* drivers);
+void GBASIOSetDriver(struct GBASIO* sio, struct GBASIODriver* driver, enum GBASIOMode mode);
 
 void GBASIOWriteRCNT(struct GBASIO* sio, uint16_t value);
 void GBASIOWriteSIOCNT(struct GBASIO* sio, uint16_t value);

src/gba/gba-thread.c

@@ -99,6 +99,8 @@ static THREAD_ENTRY _GBAThreadRun(void* context) {
 		ARMDebuggerEnter(threadContext->debugger, DEBUGGER_ENTER_ATTACHED);
 	}
 
+	GBASIOSetDriverSet(&gba.sio, &threadContext->sioDrivers);
+
 	gba.keySource = &threadContext->activeKeys;
 
 	if (threadContext->startCallback) {

src/gba/gba-thread.h

@@ -36,6 +36,7 @@ struct GBAThread {
 
 	// Input
 	struct GBAVideoRenderer* renderer;
+	struct GBASIODriverSet sioDrivers;
 	struct ARMDebugger* debugger;
 	int fd;
 	int biosFd;