1/* Copyright (c) 2013-2018 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 <mgba/gba/interface.h>
  7
  8#include <mgba/internal/gba/gba.h>
  9#include <mgba/internal/gba/io.h>
 10#include <mgba/internal/gba/sio.h>
 11
 12mLOG_DECLARE_CATEGORY(GBA_BATTLECHIP);
 13mLOG_DEFINE_CATEGORY(GBA_BATTLECHIP, "GBA BattleChip Gate", "gba.battlechip");
 14
 15enum {
 16	BATTLECHIP_STATE_COMMAND = 0,
 17	BATTLECHIP_STATE_UNK_0 = 1,
 18	BATTLECHIP_STATE_UNK_1 = 2,
 19	BATTLECHIP_STATE_DATA_0 = 3,
 20	BATTLECHIP_STATE_DATA_1 = 4,
 21	BATTLECHIP_STATE_ID = 5,
 22	BATTLECHIP_STATE_UNK_2 = 6,
 23	BATTLECHIP_STATE_UNK_3 = 7,
 24	BATTLECHIP_STATE_END = 8
 25};
 26
 27enum {
 28	BATTLECHIP_OK = 0xFFC6,
 29	PROGRESS_GATE_OK = 0xFFC7,
 30	BEAST_LINK_GATE_OK = 0xFFC4,
 31	BEAST_LINK_GATE_US_OK = 0xFF00,
 32	BATTLECHIP_CONTINUE = 0xFFFF,
 33};
 34
 35static bool GBASIOBattlechipGateInit(struct GBASIODriver* driver);
 36static bool GBASIOBattlechipGateLoad(struct GBASIODriver* driver);
 37static uint16_t GBASIOBattlechipGateWriteRegister(struct GBASIODriver* driver, uint32_t address, uint16_t value);
 38
 39static void _battlechipTransfer(struct GBASIOBattlechipGate* gate);
 40static void _battlechipTransferEvent(struct mTiming* timing, void* user, uint32_t cyclesLate);
 41
 42void GBASIOBattlechipGateCreate(struct GBASIOBattlechipGate* gate) {
 43	gate->d.init = GBASIOBattlechipGateInit;
 44	gate->d.deinit = NULL;
 45	gate->d.load = GBASIOBattlechipGateLoad;
 46	gate->d.unload = NULL;
 47	gate->d.writeRegister = GBASIOBattlechipGateWriteRegister;
 48
 49	gate->event.context = gate;
 50	gate->event.callback = _battlechipTransferEvent;
 51	gate->event.priority = 0x80;
 52
 53	gate->chipId = 0;
 54	gate->flavor = GBA_FLAVOR_BATTLECHIP_GATE;
 55}
 56
 57bool GBASIOBattlechipGateInit(struct GBASIODriver* driver) {
 58	struct GBASIOBattlechipGate* gate = (struct GBASIOBattlechipGate*) driver;
 59	return true;
 60}
 61
 62bool GBASIOBattlechipGateLoad(struct GBASIODriver* driver) {
 63	struct GBASIOBattlechipGate* gate = (struct GBASIOBattlechipGate*) driver;
 64	gate->state = BATTLECHIP_STATE_COMMAND;
 65	gate->data[0] = 0x00FE;
 66	gate->data[1] = 0xFFFE;
 67	return true;
 68}
 69
 70uint16_t GBASIOBattlechipGateWriteRegister(struct GBASIODriver* driver, uint32_t address, uint16_t value) {
 71	struct GBASIOBattlechipGate* gate = (struct GBASIOBattlechipGate*) driver;
 72	switch (address) {
 73	case REG_SIOCNT:
 74		value &= ~0xC;
 75		value |= 0x8;
 76		if (value & 0x80) {
 77			_battlechipTransfer(gate);
 78		}
 79		break;
 80	case REG_SIOMLT_SEND:
 81		break;
 82	case REG_RCNT:
 83		break;
 84	default:
 85		break;
 86	}
 87	return value;
 88}
 89
 90void _battlechipTransfer(struct GBASIOBattlechipGate* gate) {
 91	int32_t cycles;
 92	if (gate->d.p->mode == SIO_NORMAL_32) {
 93		cycles = GBA_ARM7TDMI_FREQUENCY / 0x40000;
 94	} else {
 95		cycles = GBASIOCyclesPerTransfer[gate->d.p->multiplayerControl.baud][1];
 96	}
 97	mTimingDeschedule(&gate->d.p->p->timing, &gate->event);
 98	mTimingSchedule(&gate->d.p->p->timing, &gate->event, cycles);
 99}
100
101void _battlechipTransferEvent(struct mTiming* timing, void* user, uint32_t cyclesLate) {
102	struct GBASIOBattlechipGate* gate = user;
103
104	if (gate->d.p->mode == SIO_NORMAL_32) {
105		gate->d.p->p->memory.io[REG_SIODATA32_LO >> 1] = 0;
106		gate->d.p->p->memory.io[REG_SIODATA32_HI >> 1] = 0;
107		gate->d.p->normalControl.start = 0;
108		if (gate->d.p->normalControl.irq) {
109			GBARaiseIRQ(gate->d.p->p, IRQ_SIO);
110		}
111		return;
112	}
113
114	uint16_t cmd = gate->d.p->p->memory.io[REG_SIOMLT_SEND >> 1];
115	uint16_t reply = 0xFFFF;
116	gate->d.p->p->memory.io[REG_SIOMULTI0 >> 1] = cmd;
117	gate->d.p->p->memory.io[REG_SIOMULTI2 >> 1] = 0xFFFF;
118	gate->d.p->p->memory.io[REG_SIOMULTI3 >> 1] = 0xFFFF;
119	gate->d.p->multiplayerControl.busy = 0;
120	gate->d.p->multiplayerControl.id = 0;
121
122	mLOG(GBA_BATTLECHIP, DEBUG, "> %04X", cmd);
123
124	uint16_t ok;
125	switch (gate->flavor) {
126	case GBA_FLAVOR_BATTLECHIP_GATE:
127	default:
128		ok = BATTLECHIP_OK;
129		break;
130	case GBA_FLAVOR_PROGRESS_GATE:
131		ok = PROGRESS_GATE_OK;
132		break;
133	case GBA_FLAVOR_BEAST_LINK_GATE:
134		ok = BEAST_LINK_GATE_OK;
135		break;
136	case GBA_FLAVOR_BEAST_LINK_GATE_US:
137		ok = BEAST_LINK_GATE_US_OK;
138		break;
139	}
140
141	switch (gate->state) {
142	case BATTLECHIP_STATE_COMMAND:
143		mLOG(GBA_BATTLECHIP, DEBUG, "C %04X", cmd);
144		switch (cmd) {
145		case 0x0000:
146		case 0x8FFF:
147		case 0xA380:
148		case 0xA390:
149		case 0xA3A0:
150		case 0xA3B0:
151		case 0xA3C0:
152		case 0xA3D0:
153		case 0xA6C0:
154			gate->state = -1;
155		// Fall through
156		case 0x5379:
157		case 0x537A:
158		case 0x537B:
159		case 0x537C:
160		case 0x537D:
161		case 0x537E:
162		case 0xB7D3:
163		case 0xB7D4:
164		case 0xB7D5:
165		case 0xB7D6:
166		case 0xB7D7:
167		case 0xB7D8:
168		case 0xC4D8:
169		case 0xC4D9:
170		case 0xC4DA:
171		case 0xC4DB:
172		case 0xC4DC:
173		case 0xC4DD:
174		case 0xD979:
175		case 0xD97A:
176		case 0xD97B:
177		case 0xD97C:
178		case 0xD97D:
179		case 0xD97E:
180			reply = ok;
181			break;
182		case 0x3545:
183		case 0x3546:
184		case 0x3547:
185		case 0x3548:
186		case 0x3549:
187		case 0x354A:
188		case 0x424A:
189		case 0x424B:
190		case 0x424C:
191		case 0x424D:
192		case 0x424E:
193		case 0x424F:
194		case 0x4250:
195		case 0x5745:
196		case 0x5746:
197		case 0x5747:
198		case 0x5748:
199		case 0x5749:
200		case 0x574A:
201		case 0xFC00:
202			// Resync
203			gate->state = BATTLECHIP_STATE_UNK_0;
204			break;
205		default:
206			mLOG(GBA_BATTLECHIP, STUB, "? %04X", cmd);
207			break;
208		}
209		break;
210	case BATTLECHIP_STATE_UNK_0:
211	case BATTLECHIP_STATE_UNK_1:
212		reply = 0xFFFF;
213		break;
214	case BATTLECHIP_STATE_DATA_0:
215		reply = gate->data[0];
216		gate->data[0] += 3;
217		gate->data[0] &= 0x00FF;
218		break;
219	case BATTLECHIP_STATE_DATA_1:
220		reply = gate->data[1];
221		gate->data[1] -= 3;
222		gate->data[1] |= 0xFC00;
223		break;
224	case BATTLECHIP_STATE_ID:
225		reply = gate->chipId;
226		break;
227	case BATTLECHIP_STATE_UNK_2:
228	case BATTLECHIP_STATE_UNK_3:
229		reply = 0;
230		break;
231	case BATTLECHIP_STATE_END:
232		reply = ok;
233		gate->state = -1;
234		break;
235	}
236	++gate->state;
237
238	mLOG(GBA_BATTLECHIP, DEBUG, "< %04X", reply);
239
240	gate->d.p->p->memory.io[REG_SIOMULTI1 >> 1] = reply;
241
242	if (gate->d.p->multiplayerControl.irq) {
243		GBARaiseIRQ(gate->d.p->p, IRQ_SIO);
244	}
245}