1/* Copyright (c) 2013-2015 Jeffrey Pfau
  2 *
  3 * This Source Code Form is subject to the terms of the Mozilla Public
  4 * License, v. 2.0. If a copy of the MPL was not distributed with this
  5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
  6#include "sio.h"
  7
  8#include "gba/io.h"
  9
 10const int GBASIOCyclesPerTransfer[4][MAX_GBAS] = {
 11	{ 38326, 73003, 107680, 142356 },
 12	{ 9582, 18251, 26920, 35589 },
 13	{ 6388, 12167, 17947, 23726 },
 14	{ 3194, 6075, 8973, 11863 }
 15};
 16
 17static struct GBASIODriver* _lookupDriver(struct GBASIO* sio, enum GBASIOMode mode) {
 18	switch (mode) {
 19	case SIO_NORMAL_8:
 20	case SIO_NORMAL_32:
 21		return sio->drivers.normal;
 22	case SIO_MULTI:
 23		return sio->drivers.multiplayer;
 24	case SIO_JOYBUS:
 25		return sio->drivers.joybus;
 26	default:
 27		return 0;
 28	}
 29}
 30
 31static void _switchMode(struct GBASIO* sio) {
 32	unsigned mode = ((sio->rcnt & 0xC000) | (sio->siocnt & 0x3000)) >> 12;
 33	enum GBASIOMode oldMode = sio->mode;
 34	if (mode < 8) {
 35		sio->mode = (enum GBASIOMode) (mode & 0x3);
 36	} else {
 37		sio->mode = (enum GBASIOMode) (mode & 0xC);
 38	}
 39	if (oldMode != sio->mode) {
 40		if (sio->activeDriver && sio->activeDriver->unload) {
 41			sio->activeDriver->unload(sio->activeDriver);
 42		}
 43		sio->activeDriver = _lookupDriver(sio, sio->mode);
 44		if (sio->activeDriver && sio->activeDriver->load) {
 45			sio->activeDriver->load(sio->activeDriver);
 46		}
 47	}
 48}
 49
 50void GBASIOInit(struct GBASIO* sio) {
 51	sio->drivers.normal = 0;
 52	sio->drivers.multiplayer = 0;
 53	sio->drivers.joybus = 0;
 54	GBASIOReset(sio);
 55}
 56
 57void GBASIODeinit(struct GBASIO* sio) {
 58	if (sio->activeDriver && sio->activeDriver->unload) {
 59		sio->activeDriver->unload(sio->activeDriver);
 60	}
 61	if (sio->drivers.multiplayer && sio->drivers.multiplayer->deinit) {
 62		sio->drivers.multiplayer->deinit(sio->drivers.multiplayer);
 63	}
 64	if (sio->drivers.joybus && sio->drivers.joybus->deinit) {
 65		sio->drivers.joybus->deinit(sio->drivers.joybus);
 66	}
 67}
 68
 69void GBASIOReset(struct GBASIO* sio) {
 70	GBASIODeinit(sio);
 71	sio->rcnt = RCNT_INITIAL;
 72	sio->siocnt = 0;
 73	sio->mode = -1;
 74	sio->activeDriver = 0;
 75	_switchMode(sio);
 76}
 77
 78void GBASIOSetDriverSet(struct GBASIO* sio, struct GBASIODriverSet* drivers) {
 79	GBASIOSetDriver(sio, drivers->normal, SIO_NORMAL_8);
 80	GBASIOSetDriver(sio, drivers->multiplayer, SIO_MULTI);
 81	GBASIOSetDriver(sio, drivers->joybus, SIO_JOYBUS);
 82}
 83
 84void GBASIOSetDriver(struct GBASIO* sio, struct GBASIODriver* driver, enum GBASIOMode mode) {
 85	struct GBASIODriver** driverLoc;
 86	switch (mode) {
 87	case SIO_NORMAL_8:
 88	case SIO_NORMAL_32:
 89		driverLoc = &sio->drivers.normal;
 90		break;
 91	case SIO_MULTI:
 92		driverLoc = &sio->drivers.multiplayer;
 93		break;
 94	case SIO_JOYBUS:
 95		driverLoc = &sio->drivers.joybus;
 96		break;
 97	default:
 98		GBALog(sio->p, GBA_LOG_ERROR, "Setting an unsupported SIO driver: %x", mode);
 99		return;
100	}
101	if (*driverLoc) {
102		if ((*driverLoc)->unload) {
103			(*driverLoc)->unload(*driverLoc);
104		}
105		if ((*driverLoc)->deinit) {
106			(*driverLoc)->deinit(*driverLoc);
107		}
108	}
109	if (driver) {
110		driver->p = sio;
111
112		if (driver->init) {
113			if (!driver->init(driver)) {
114				driver->deinit(driver);
115				GBALog(sio->p, GBA_LOG_ERROR, "Could not initialize SIO driver");
116				return;
117			}
118		}
119		if (sio->mode == mode) {
120			sio->activeDriver = driver;
121			if (driver->load) {
122				driver->load(driver);
123			}
124		}
125	}
126	*driverLoc = driver;
127}
128
129void GBASIOWriteRCNT(struct GBASIO* sio, uint16_t value) {
130	sio->rcnt &= 0xF;
131	sio->rcnt |= value & ~0xF;
132	_switchMode(sio);
133	if (sio->activeDriver && sio->activeDriver->writeRegister) {
134		sio->activeDriver->writeRegister(sio->activeDriver, REG_RCNT, value);
135	}
136}
137
138void GBASIOWriteSIOCNT(struct GBASIO* sio, uint16_t value) {
139	if ((value ^ sio->siocnt) & 0x3000) {
140		sio->siocnt = value & 0x3000;
141		_switchMode(sio);
142	}
143	if (sio->activeDriver && sio->activeDriver->writeRegister) {
144		value = sio->activeDriver->writeRegister(sio->activeDriver, REG_SIOCNT, value);
145	} else {
146		// Dummy drivers
147		switch (sio->mode) {
148		case SIO_NORMAL_8:
149		case SIO_NORMAL_32:
150			value |= 0x0004;
151			if ((value & 0x4080) == 0x4080) {
152				// TODO: Test this on hardware to see if this is correct
153				GBARaiseIRQ(sio->p, IRQ_SIO);
154			}
155			value &= ~0x0080;
156			break;
157		default:
158			// TODO
159			break;
160		}
161	}
162	sio->siocnt = value;
163}
164
165void GBASIOWriteSIOMLT_SEND(struct GBASIO* sio, uint16_t value) {
166	if (sio->activeDriver && sio->activeDriver->writeRegister) {
167		sio->activeDriver->writeRegister(sio->activeDriver, REG_SIOMLT_SEND, value);
168	}
169}
170
171int32_t GBASIOProcessEvents(struct GBASIO* sio, int32_t cycles) {
172	if (sio->activeDriver && sio->activeDriver->processEvents) {
173		return sio->activeDriver->processEvents(sio->activeDriver, cycles);
174	}
175	return INT_MAX;
176}