aboutsummaryrefslogtreecommitdiff
path: root/hw/misc/max111x.c
blob: 1b5da699b91ff3e80dcd5643b007919205abcd6e (plain)
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
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
/*
 * Maxim MAX1110/1111 ADC chip emulation.
 *
 * Copyright (c) 2006 Openedhand Ltd.
 * Written by Andrzej Zaborowski <balrog@zabor.org>
 *
 * This code is licensed under the GNU GPLv2.
 *
 * Contributions after 2012-01-13 are licensed under the terms of the
 * GNU GPL, version 2 or (at your option) any later version.
 */

#include "hw/ssi.h"

typedef struct {
    SSISlave ssidev;
    qemu_irq interrupt;
    uint8_t tb1, rb2, rb3;
    int cycle;

    uint8_t input[8];
    int inputs, com;
} MAX111xState;

#define TYPE_MAX_111X "max111x"

#define TYPE_MAX_1110 "max1110"
#define TYPE_MAX_1111 "max1111"

/* Control-byte bitfields */
#define CB_PD0		(1 << 0)
#define CB_PD1		(1 << 1)
#define CB_SGL		(1 << 2)
#define CB_UNI		(1 << 3)
#define CB_SEL0		(1 << 4)
#define CB_SEL1		(1 << 5)
#define CB_SEL2		(1 << 6)
#define CB_START	(1 << 7)

#define CHANNEL_NUM(v, b0, b1, b2)	\
			((((v) >> (2 + (b0))) & 4) |	\
			 (((v) >> (3 + (b1))) & 2) |	\
			 (((v) >> (4 + (b2))) & 1))

static uint32_t max111x_read(MAX111xState *s)
{
    if (!s->tb1)
        return 0;

    switch (s->cycle ++) {
    case 1:
        return s->rb2;
    case 2:
        return s->rb3;
    }

    return 0;
}

/* Interpret a control-byte */
static void max111x_write(MAX111xState *s, uint32_t value)
{
    int measure, chan;

    /* Ignore the value if START bit is zero */
    if (!(value & CB_START))
        return;

    s->cycle = 0;

    if (!(value & CB_PD1)) {
        s->tb1 = 0;
        return;
    }

    s->tb1 = value;

    if (s->inputs == 8)
        chan = CHANNEL_NUM(value, 1, 0, 2);
    else
        chan = CHANNEL_NUM(value & ~CB_SEL0, 0, 1, 2);

    if (value & CB_SGL)
        measure = s->input[chan] - s->com;
    else
        measure = s->input[chan] - s->input[chan ^ 1];

    if (!(value & CB_UNI))
        measure ^= 0x80;

    s->rb2 = (measure >> 2) & 0x3f;
    s->rb3 = (measure << 6) & 0xc0;

    /* FIXME: When should the IRQ be lowered?  */
    qemu_irq_raise(s->interrupt);
}

static uint32_t max111x_transfer(SSISlave *dev, uint32_t value)
{
    MAX111xState *s = FROM_SSI_SLAVE(MAX111xState, dev);
    max111x_write(s, value);
    return max111x_read(s);
}

static const VMStateDescription vmstate_max111x = {
    .name = "max111x",
    .version_id = 1,
    .minimum_version_id = 1,
    .minimum_version_id_old = 1,
    .fields      = (VMStateField[]) {
        VMSTATE_SSI_SLAVE(ssidev, MAX111xState),
        VMSTATE_UINT8(tb1, MAX111xState),
        VMSTATE_UINT8(rb2, MAX111xState),
        VMSTATE_UINT8(rb3, MAX111xState),
        VMSTATE_INT32_EQUAL(inputs, MAX111xState),
        VMSTATE_INT32(com, MAX111xState),
        VMSTATE_ARRAY_INT32_UNSAFE(input, MAX111xState, inputs,
                                   vmstate_info_uint8, uint8_t),
        VMSTATE_END_OF_LIST()
    }
};

static int max111x_init(SSISlave *d, int inputs)
{
    DeviceState *dev = DEVICE(d);
    MAX111xState *s = FROM_SSI_SLAVE(MAX111xState, d);

    qdev_init_gpio_out(dev, &s->interrupt, 1);

    s->inputs = inputs;
    /* TODO: add a user interface for setting these */
    s->input[0] = 0xf0;
    s->input[1] = 0xe0;
    s->input[2] = 0xd0;
    s->input[3] = 0xc0;
    s->input[4] = 0xb0;
    s->input[5] = 0xa0;
    s->input[6] = 0x90;
    s->input[7] = 0x80;
    s->com = 0;

    vmstate_register(dev, -1, &vmstate_max111x, s);
    return 0;
}

static int max1110_init(SSISlave *dev)
{
    return max111x_init(dev, 8);
}

static int max1111_init(SSISlave *dev)
{
    return max111x_init(dev, 4);
}

void max111x_set_input(DeviceState *dev, int line, uint8_t value)
{
    MAX111xState *s = FROM_SSI_SLAVE(MAX111xState, SSI_SLAVE_FROM_QDEV(dev));
    assert(line >= 0 && line < s->inputs);
    s->input[line] = value;
}

static void max111x_class_init(ObjectClass *klass, void *data)
{
    SSISlaveClass *k = SSI_SLAVE_CLASS(klass);

    k->transfer = max111x_transfer;
}

static const TypeInfo max111x_info = {
    .name          = TYPE_MAX_111X,
    .parent        = TYPE_SSI_SLAVE,
    .instance_size = sizeof(MAX111xState),
    .class_init    = max111x_class_init,
    .abstract      = true,
};

static void max1110_class_init(ObjectClass *klass, void *data)
{
    SSISlaveClass *k = SSI_SLAVE_CLASS(klass);

    k->init = max1110_init;
}

static const TypeInfo max1110_info = {
    .name          = TYPE_MAX_1110,
    .parent        = TYPE_MAX_111X,
    .class_init    = max1110_class_init,
};

static void max1111_class_init(ObjectClass *klass, void *data)
{
    SSISlaveClass *k = SSI_SLAVE_CLASS(klass);

    k->init = max1111_init;
}

static const TypeInfo max1111_info = {
    .name          = TYPE_MAX_1111,
    .parent        = TYPE_MAX_111X,
    .class_init    = max1111_class_init,
};

static void max111x_register_types(void)
{
    type_register_static(&max111x_info);
    type_register_static(&max1110_info);
    type_register_static(&max1111_info);
}

type_init(max111x_register_types)