1/* Copyright (c) 2013-2017 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/internal/gba/sio.h>
 7
 8#include <mgba/internal/gba/gba.h>
 9#include <mgba/internal/gba/io.h>
10
11static uint16_t GBASIOJOYWriteRegister(struct GBASIODriver* sio, uint32_t address, uint16_t value);
12
13void GBASIOJOYCreate(struct GBASIODriver* sio) {
14	sio->init = NULL;
15	sio->deinit = NULL;
16	sio->load = NULL;
17	sio->unload = NULL;
18	sio->writeRegister = GBASIOJOYWriteRegister;
19}
20
21uint16_t GBASIOJOYWriteRegister(struct GBASIODriver* sio, uint32_t address, uint16_t value) {
22	switch (address) {
23	case REG_JOYCNT:
24		mLOG(GBA_SIO, DEBUG, "JOY write: CNT <- %04X", value);
25		return (value & 0x0040) | (sio->p->p->memory.io[REG_JOYCNT >> 1] & ~(value & 0x7) & ~0x0040);
26	case REG_JOYSTAT:
27		mLOG(GBA_SIO, DEBUG, "JOY write: STAT <- %04X", value);
28		return (value & 0x0030) | (sio->p->p->memory.io[REG_JOYSTAT >> 1] & ~0x30);
29	case REG_JOY_TRANS_LO:
30		mLOG(GBA_SIO, DEBUG, "JOY write: TRANS_LO <- %04X", value);
31		break;
32	case REG_JOY_TRANS_HI:
33		mLOG(GBA_SIO, DEBUG, "JOY write: TRANS_HI <- %04X", value);
34		break;
35	default:
36		mLOG(GBA_SIO, DEBUG, "JOY write: Unknown reg %03X <- %04X", address, value);
37		// Fall through
38	case REG_RCNT:
39		break;
40	}
41	return value;
42}
43
44int GBASIOJOYSendCommand(struct GBASIODriver* sio, enum GBASIOJOYCommand command, uint8_t* data) {
45	switch (command) {
46	case JOY_RESET:
47		sio->p->p->memory.io[REG_JOYCNT >> 1] |= JOYCNT_RESET;
48		if (sio->p->p->memory.io[REG_JOYCNT >> 1] & 0x40) {
49			GBARaiseIRQ(sio->p->p, IRQ_SIO, 0);
50		}
51		// Fall through
52	case JOY_POLL:
53		data[0] = 0x00;
54		data[1] = 0x04;
55		data[2] = sio->p->p->memory.io[REG_JOYSTAT >> 1];
56
57		mLOG(GBA_SIO, DEBUG, "JOY %s: %02X (%02X)", command == JOY_POLL ? "poll" : "reset", data[2], sio->p->p->memory.io[REG_JOYCNT >> 1]);
58		return 3;
59	case JOY_RECV:
60		sio->p->p->memory.io[REG_JOYCNT >> 1] |= JOYCNT_RECV;
61		sio->p->p->memory.io[REG_JOYSTAT >> 1] |= JOYSTAT_RECV;
62
63		sio->p->p->memory.io[REG_JOY_RECV_LO >> 1] = data[0] | (data[1] << 8);
64		sio->p->p->memory.io[REG_JOY_RECV_HI >> 1] = data[2] | (data[3] << 8);
65
66		data[0] = sio->p->p->memory.io[REG_JOYSTAT >> 1];
67
68		mLOG(GBA_SIO, DEBUG, "JOY recv: %02X (%02X)", data[0], sio->p->p->memory.io[REG_JOYCNT >> 1]);
69
70		if (sio->p->p->memory.io[REG_JOYCNT >> 1] & 0x40) {
71			GBARaiseIRQ(sio->p->p, IRQ_SIO, 0);
72		}
73		return 1;
74	case JOY_TRANS:
75		data[0] = sio->p->p->memory.io[REG_JOY_TRANS_LO >> 1];
76		data[1] = sio->p->p->memory.io[REG_JOY_TRANS_LO >> 1] >> 8;
77		data[2] = sio->p->p->memory.io[REG_JOY_TRANS_HI >> 1];
78		data[3] = sio->p->p->memory.io[REG_JOY_TRANS_HI >> 1] >> 8;
79		data[4] = sio->p->p->memory.io[REG_JOYSTAT >> 1];
80
81		sio->p->p->memory.io[REG_JOYCNT >> 1] |= JOYCNT_TRANS;
82		sio->p->p->memory.io[REG_JOYSTAT >> 1] &= ~JOYSTAT_TRANS;
83
84		mLOG(GBA_SIO, DEBUG, "JOY trans: %02X%02X%02X%02X:%02X (%02X)", data[0], data[1], data[2], data[3], data[4], sio->p->p->memory.io[REG_JOYCNT >> 1]);
85
86		if (sio->p->p->memory.io[REG_JOYCNT >> 1] & 0x40) {
87			GBARaiseIRQ(sio->p->p, IRQ_SIO, 0);
88		}
89		return 5;
90	}
91	return 0;
92}