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 != mode) {
 40		if (sio->activeDriver && sio->activeDriver->unload) {
 41			sio->activeDriver->unload(sio->activeDriver);
 42		}
 43		sio->activeDriver = _lookupDriver(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->rcnt = RCNT_INITIAL;
 52	sio->siocnt = 0;
 53	sio->mode = -1;
 54	sio->activeDriver = 0;
 55	sio->drivers.normal = 0;
 56	sio->drivers.multiplayer = 0;
 57	sio->drivers.joybus = 0;
 58	_switchMode(sio);
 59}
 60
 61void GBASIODeinit(struct GBASIO* sio) {
 62	if (sio->activeDriver && sio->activeDriver->unload) {
 63		sio->activeDriver->unload(sio->activeDriver);
 64	}
 65	if (sio->drivers.multiplayer && sio->drivers.multiplayer->deinit) {
 66		sio->drivers.multiplayer->deinit(sio->drivers.multiplayer);
 67	}
 68	if (sio->drivers.joybus && sio->drivers.joybus->deinit) {
 69		sio->drivers.joybus->deinit(sio->drivers.joybus);
 70	}
 71}
 72
 73void GBASIOSetDriverSet(struct GBASIO* sio, struct GBASIODriverSet* drivers) {
 74	GBASIOSetDriver(sio, drivers->normal, SIO_NORMAL_8);
 75	GBASIOSetDriver(sio, drivers->multiplayer, SIO_MULTI);
 76	GBASIOSetDriver(sio, drivers->joybus, SIO_JOYBUS);
 77}
 78
 79void GBASIOSetDriver(struct GBASIO* sio, struct GBASIODriver* driver, enum GBASIOMode mode) {
 80	struct GBASIODriver** driverLoc;
 81	switch (mode) {
 82	case SIO_NORMAL_8:
 83	case SIO_NORMAL_32:
 84		driverLoc = &sio->drivers.normal;
 85		break;
 86	case SIO_MULTI:
 87		driverLoc = &sio->drivers.multiplayer;
 88		break;
 89	case SIO_JOYBUS:
 90		driverLoc = &sio->drivers.joybus;
 91		break;
 92	default:
 93		GBALog(sio->p, GBA_LOG_ERROR, "Setting an unsupported SIO driver: %x", mode);
 94		return;
 95	}
 96	if (*driverLoc) {
 97		if ((*driverLoc)->unload) {
 98			(*driverLoc)->unload(*driverLoc);
 99		}
100		if ((*driverLoc)->deinit) {
101			(*driverLoc)->deinit(*driverLoc);
102		}
103	}
104	if (driver) {
105		driver->p = sio;
106
107		if (driver->init) {
108			if (!driver->init(driver)) {
109				driver->deinit(driver);
110				GBALog(sio->p, GBA_LOG_ERROR, "Could not initialize SIO driver");
111				return;
112			}
113		}
114		if (sio->mode == mode) {
115			sio->activeDriver = driver;
116			if (driver->load) {
117				driver->load(driver);
118			}
119		}
120	}
121	*driverLoc = driver;
122}
123
124void GBASIOWriteRCNT(struct GBASIO* sio, uint16_t value) {
125	sio->rcnt = value;
126	_switchMode(sio);
127	if (sio->activeDriver && sio->activeDriver->writeRegister) {
128		sio->activeDriver->writeRegister(sio->activeDriver, REG_RCNT, value);
129	}
130}
131
132void GBASIOWriteSIOCNT(struct GBASIO* sio, uint16_t value) {
133	if (sio->activeDriver && sio->activeDriver->writeRegister) {
134		value = sio->activeDriver->writeRegister(sio->activeDriver, REG_SIOCNT, value);
135	}
136	sio->siocnt = value;
137	_switchMode(sio);
138}
139
140void GBASIOWriteSIOMLT_SEND(struct GBASIO* sio, uint16_t value) {
141	if (sio->activeDriver && sio->activeDriver->writeRegister) {
142		sio->activeDriver->writeRegister(sio->activeDriver, REG_SIOMLT_SEND, value);
143	}
144}
145
146int32_t GBASIOProcessEvents(struct GBASIO* sio, int32_t cycles) {
147	if (sio->activeDriver && sio->activeDriver->processEvents) {
148		return sio->activeDriver->processEvents(sio->activeDriver, cycles);
149	}
150	return INT_MAX;
151}