summaryrefslogtreecommitdiffstatshomepage
path: root/src/emu/bus/snes_ctrl/joypad.c
blob: 4b26d35b8874e41a53e06d897d99ce78577decfd (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
/**********************************************************************

    Nintendo Super Famicom & SNES Joypad

    Copyright MESS Team.
    Visit http://mamedev.org for licensing and usage restrictions.

**********************************************************************/

#include "joypad.h"

//**************************************************************************
//  DEVICE DEFINITIONS
//**************************************************************************

const device_type SNES_JOYPAD = &device_creator<snes_joypad_device>;


static INPUT_PORTS_START( snes_joypad )
	PORT_START("JOYPAD")
	PORT_BIT( 0x0001, IP_ACTIVE_HIGH, IPT_BUTTON1 ) PORT_NAME("B")
	PORT_BIT( 0x0002, IP_ACTIVE_HIGH, IPT_BUTTON4 ) PORT_NAME("Y")
	PORT_BIT( 0x0004, IP_ACTIVE_HIGH, IPT_SELECT ) PORT_NAME("Select")
	PORT_BIT( 0x0008, IP_ACTIVE_HIGH, IPT_START1 ) PORT_NAME("Start")
	PORT_BIT( 0x0010, IP_ACTIVE_HIGH, IPT_JOYSTICK_UP )
	PORT_BIT( 0x0020, IP_ACTIVE_HIGH, IPT_JOYSTICK_DOWN )
	PORT_BIT( 0x0040, IP_ACTIVE_HIGH, IPT_JOYSTICK_LEFT )
	PORT_BIT( 0x0080, IP_ACTIVE_HIGH, IPT_JOYSTICK_RIGHT )
	PORT_BIT( 0x0100, IP_ACTIVE_HIGH, IPT_BUTTON2 ) PORT_NAME("A")
	PORT_BIT( 0x0200, IP_ACTIVE_HIGH, IPT_BUTTON5 ) PORT_NAME("X")
	PORT_BIT( 0x0400, IP_ACTIVE_HIGH, IPT_BUTTON6 ) PORT_NAME("L")
	PORT_BIT( 0x0800, IP_ACTIVE_HIGH, IPT_BUTTON3 ) PORT_NAME("R")
	PORT_BIT( 0xf000, IP_ACTIVE_HIGH, IPT_UNUSED )
INPUT_PORTS_END


//-------------------------------------------------
//  input_ports - device-specific input ports
//-------------------------------------------------

ioport_constructor snes_joypad_device::device_input_ports() const
{
	return INPUT_PORTS_NAME( snes_joypad );
}



//**************************************************************************
//  LIVE DEVICE
//**************************************************************************

//-------------------------------------------------
//  snes_joypad_device - constructor
//-------------------------------------------------

snes_joypad_device::snes_joypad_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) :
					device_t(mconfig, SNES_JOYPAD, "Nintendo SNES / SFC Control Pad", tag, owner, clock, "snes_joypad", __FILE__),
					device_snes_control_port_interface(mconfig, *this),
					m_joypad(*this, "JOYPAD")
{
}


//-------------------------------------------------
//  device_start - device-specific startup
//-------------------------------------------------

void snes_joypad_device::device_start()
{
	save_item(NAME(m_latch));
	save_item(NAME(m_strobe));
}


//-------------------------------------------------
//  device_reset - device-specific reset
//-------------------------------------------------

void snes_joypad_device::device_reset()
{
	m_latch = 0;
	m_strobe = 0;
}


//-------------------------------------------------
//  poll
//-------------------------------------------------

void snes_joypad_device::port_poll()
{
	UINT16 temp = m_joypad->read();
	// avoid sending signals that could crash games
	// if left, no right
	if (temp & 0x40)
		temp &= ~0x80;
	// if up, no down
	if (temp & 0x10)
		temp &= ~0x20;

	m_latch = temp | 0xffff0000;
}

//-------------------------------------------------
//  read
//-------------------------------------------------

UINT8 snes_joypad_device::read_pin4()
{
	UINT8 ret = m_latch & 1;
	m_latch >>= 1;
	return ret;
}

//-------------------------------------------------
//  write
//-------------------------------------------------

void snes_joypad_device::write_strobe(UINT8 data)
{
	int old = m_strobe;
	m_strobe = data & 0x01;

	if (m_strobe < old) // 1 -> 0 transition
		port_poll();
}