1#include "gba-sio.h"
  2
  3#include "gba-io.h"
  4
  5#include <limits.h>
  6
  7static struct GBASIODriver* _lookupDriver(struct GBASIO* sio, enum GBASIOMode mode) {
  8	switch (mode) {
  9	case SIO_NORMAL_8:
 10	case SIO_NORMAL_32:
 11		return sio->drivers.normal;
 12	case SIO_MULTI:
 13		return sio->drivers.multiplayer;
 14	case SIO_JOYBUS:
 15		return sio->drivers.joybus;
 16	default:
 17		return 0;
 18	}
 19}
 20
 21static void _switchMode(struct GBASIO* sio) {
 22	int mode = ((sio->rcnt >> 14) & 0xC) | ((sio->siocnt >> 12) & 0x3);
 23	enum GBASIOMode oldMode = sio->mode;
 24	if (mode < 8) {
 25		sio->mode = (enum GBASIOMode) (mode & 0x3);
 26	} else {
 27		sio->mode = (enum GBASIOMode) (mode & 0xC);
 28	}
 29	if (oldMode != mode) {
 30		if (sio->activeDriver && sio->activeDriver->unload) {
 31			sio->activeDriver->unload(sio->activeDriver);
 32		}
 33		sio->activeDriver = _lookupDriver(sio, mode);
 34		if (sio->activeDriver && sio->activeDriver->load) {
 35			sio->activeDriver->load(sio->activeDriver);
 36		}
 37	}
 38}
 39
 40void GBASIOInit(struct GBASIO* sio) {
 41	sio->rcnt = RCNT_INITIAL;
 42	sio->siocnt = 0;
 43	sio->mode = -1;
 44	sio->activeDriver = 0;
 45	_switchMode(sio);
 46}
 47
 48void GBASIODeinit(struct GBASIO* sio) {
 49	if (sio->drivers.multiplayer && sio->drivers.multiplayer->deinit) {
 50		sio->drivers.multiplayer->deinit(sio->drivers.multiplayer);
 51	}
 52	if (sio->drivers.joybus && sio->drivers.joybus->deinit) {
 53		sio->drivers.joybus->deinit(sio->drivers.joybus);
 54	}
 55}
 56
 57void GBASIOSetDriverSet(struct GBASIO* sio, struct GBASIODriverSet* drivers) {
 58	if (drivers->normal) {
 59		GBASIOSetDriver(sio, drivers->normal, SIO_NORMAL_8);
 60	}
 61	if (drivers->multiplayer) {
 62		GBASIOSetDriver(sio, drivers->multiplayer, SIO_MULTI);
 63	}
 64	if (drivers->joybus) {
 65		GBASIOSetDriver(sio, drivers->multiplayer, SIO_JOYBUS);
 66	}
 67}
 68
 69void GBASIOSetDriver(struct GBASIO* sio, struct GBASIODriver* driver, enum GBASIOMode mode) {
 70	struct GBASIODriver** driverLoc;
 71	switch (mode) {
 72	case SIO_NORMAL_8:
 73	case SIO_NORMAL_32:
 74		driverLoc = &sio->drivers.normal;
 75		break;
 76	case SIO_MULTI:
 77		driverLoc = &sio->drivers.multiplayer;
 78		break;
 79	case SIO_JOYBUS:
 80		driverLoc = &sio->drivers.joybus;
 81		break;
 82	default:
 83		GBALog(sio->p, GBA_LOG_ERROR, "Setting an unsupported SIO driver: %x", mode);
 84		return;
 85	}
 86	if (*driverLoc) {
 87		if ((*driverLoc)->unload) {
 88			(*driverLoc)->unload(*driverLoc);
 89		}
 90		if ((*driverLoc)->deinit) {
 91			(*driverLoc)->deinit(*driverLoc);
 92		}
 93	}
 94	if (driver) {
 95		driver->p = sio;
 96
 97		if (driver->init) {
 98			if (!driver->init(driver)) {
 99				driver->deinit(driver);
100				GBALog(sio->p, GBA_LOG_ERROR, "Could not initialize SIO driver");
101				return;
102			}
103		}
104		if (sio->mode == mode) {
105			sio->activeDriver = driver;
106			if (driver->load) {
107				driver->load(driver);
108			}
109		}
110	}
111	*driverLoc = driver;
112}
113
114void GBASIOWriteRCNT(struct GBASIO* sio, uint16_t value) {
115	sio->rcnt = value;
116	_switchMode(sio);
117	if (sio->activeDriver && sio->activeDriver->writeRegister) {
118		sio->activeDriver->writeRegister(sio->activeDriver, REG_RCNT, value);
119	}
120}
121
122void GBASIOWriteSIOCNT(struct GBASIO* sio, uint16_t value) {
123	if (sio->activeDriver && sio->activeDriver->writeRegister) {
124		value = sio->activeDriver->writeRegister(sio->activeDriver, REG_SIOCNT, value);
125	}
126	sio->siocnt = value;
127	_switchMode(sio);
128}
129
130void GBASIOWriteSIOMLT_SEND(struct GBASIO* sio, uint16_t value) {
131	if (sio->activeDriver && sio->activeDriver->writeRegister) {
132		sio->activeDriver->writeRegister(sio->activeDriver, REG_SIOMLT_SEND, value);
133	}
134}
135
136int32_t GBASIOProcessEvents(struct GBASIO* sio, int32_t cycles) {
137	if (sio->activeDriver && sio->activeDriver->processEvents) {
138		return sio->activeDriver->processEvents(sio->activeDriver, cycles);
139	}
140	return INT_MAX;
141}