root / hw / max111x.c @ c1e1a491
History | View | Annotate | Download (3.5 kB)
1 |
/*
|
---|---|
2 |
* Maxim MAX1110/1111 ADC chip emulation.
|
3 |
*
|
4 |
* Copyright (c) 2006 Openedhand Ltd.
|
5 |
* Written by Andrzej Zaborowski <balrog@zabor.org>
|
6 |
*
|
7 |
* This code is licensed under the GNU GPLv2.
|
8 |
*/
|
9 |
|
10 |
#include "hw.h" |
11 |
#include "i2c.h" |
12 |
|
13 |
struct max111x_s {
|
14 |
qemu_irq interrupt; |
15 |
uint8_t tb1, rb2, rb3; |
16 |
int cycle;
|
17 |
|
18 |
int input[8]; |
19 |
int inputs, com;
|
20 |
}; |
21 |
|
22 |
/* Control-byte bitfields */
|
23 |
#define CB_PD0 (1 << 0) |
24 |
#define CB_PD1 (1 << 1) |
25 |
#define CB_SGL (1 << 2) |
26 |
#define CB_UNI (1 << 3) |
27 |
#define CB_SEL0 (1 << 4) |
28 |
#define CB_SEL1 (1 << 5) |
29 |
#define CB_SEL2 (1 << 6) |
30 |
#define CB_START (1 << 7) |
31 |
|
32 |
#define CHANNEL_NUM(v, b0, b1, b2) \
|
33 |
((((v) >> (2 + (b0))) & 4) | \ |
34 |
(((v) >> (3 + (b1))) & 2) | \ |
35 |
(((v) >> (4 + (b2))) & 1)) |
36 |
|
37 |
uint32_t max111x_read(void *opaque)
|
38 |
{ |
39 |
struct max111x_s *s = (struct max111x_s *) opaque; |
40 |
|
41 |
if (!s->tb1)
|
42 |
return 0; |
43 |
|
44 |
switch (s->cycle ++) {
|
45 |
case 1: |
46 |
return s->rb2;
|
47 |
case 2: |
48 |
return s->rb3;
|
49 |
} |
50 |
|
51 |
return 0; |
52 |
} |
53 |
|
54 |
/* Interpret a control-byte */
|
55 |
void max111x_write(void *opaque, uint32_t value) |
56 |
{ |
57 |
struct max111x_s *s = (struct max111x_s *) opaque; |
58 |
int measure, chan;
|
59 |
|
60 |
/* Ignore the value if START bit is zero */
|
61 |
if (!(value & CB_START))
|
62 |
return;
|
63 |
|
64 |
s->cycle = 0;
|
65 |
|
66 |
if (!(value & CB_PD1)) {
|
67 |
s->tb1 = 0;
|
68 |
return;
|
69 |
} |
70 |
|
71 |
s->tb1 = value; |
72 |
|
73 |
if (s->inputs == 8) |
74 |
chan = CHANNEL_NUM(value, 1, 0, 2); |
75 |
else
|
76 |
chan = CHANNEL_NUM(value & ~CB_SEL0, 0, 1, 2); |
77 |
|
78 |
if (value & CB_SGL)
|
79 |
measure = s->input[chan] - s->com; |
80 |
else
|
81 |
measure = s->input[chan] - s->input[chan ^ 1];
|
82 |
|
83 |
if (!(value & CB_UNI))
|
84 |
measure ^= 0x80;
|
85 |
|
86 |
s->rb2 = (measure >> 2) & 0x3f; |
87 |
s->rb3 = (measure << 6) & 0xc0; |
88 |
|
89 |
if (s->interrupt)
|
90 |
qemu_irq_raise(s->interrupt); |
91 |
} |
92 |
|
93 |
static void max111x_save(QEMUFile *f, void *opaque) |
94 |
{ |
95 |
struct max111x_s *s = (struct max111x_s *) opaque; |
96 |
int i;
|
97 |
|
98 |
qemu_put_8s(f, &s->tb1); |
99 |
qemu_put_8s(f, &s->rb2); |
100 |
qemu_put_8s(f, &s->rb3); |
101 |
qemu_put_be32(f, s->inputs); |
102 |
qemu_put_be32(f, s->com); |
103 |
for (i = 0; i < s->inputs; i ++) |
104 |
qemu_put_byte(f, s->input[i]); |
105 |
} |
106 |
|
107 |
static int max111x_load(QEMUFile *f, void *opaque, int version_id) |
108 |
{ |
109 |
struct max111x_s *s = (struct max111x_s *) opaque; |
110 |
int i;
|
111 |
|
112 |
qemu_get_8s(f, &s->tb1); |
113 |
qemu_get_8s(f, &s->rb2); |
114 |
qemu_get_8s(f, &s->rb3); |
115 |
if (s->inputs != qemu_get_be32(f))
|
116 |
return -EINVAL;
|
117 |
s->com = qemu_get_be32(f); |
118 |
for (i = 0; i < s->inputs; i ++) |
119 |
s->input[i] = qemu_get_byte(f); |
120 |
|
121 |
return 0; |
122 |
} |
123 |
|
124 |
static struct max111x_s *max111x_init(qemu_irq cb) |
125 |
{ |
126 |
struct max111x_s *s;
|
127 |
s = (struct max111x_s *)
|
128 |
qemu_mallocz(sizeof(struct max111x_s)); |
129 |
memset(s, 0, sizeof(struct max111x_s)); |
130 |
|
131 |
s->interrupt = cb; |
132 |
|
133 |
/* TODO: add a user interface for setting these */
|
134 |
s->input[0] = 0xf0; |
135 |
s->input[1] = 0xe0; |
136 |
s->input[2] = 0xd0; |
137 |
s->input[3] = 0xc0; |
138 |
s->input[4] = 0xb0; |
139 |
s->input[5] = 0xa0; |
140 |
s->input[6] = 0x90; |
141 |
s->input[7] = 0x80; |
142 |
s->com = 0;
|
143 |
|
144 |
register_savevm("max111x", -1, 0, max111x_save, max111x_load, s); |
145 |
|
146 |
return s;
|
147 |
} |
148 |
|
149 |
struct max111x_s *max1110_init(qemu_irq cb)
|
150 |
{ |
151 |
struct max111x_s *s = max111x_init(cb);
|
152 |
s->inputs = 8;
|
153 |
return s;
|
154 |
} |
155 |
|
156 |
struct max111x_s *max1111_init(qemu_irq cb)
|
157 |
{ |
158 |
struct max111x_s *s = max111x_init(cb);
|
159 |
s->inputs = 4;
|
160 |
return s;
|
161 |
} |
162 |
|
163 |
void max111x_set_input(struct max111x_s *s, int line, uint8_t value) |
164 |
{ |
165 |
if (line >= s->inputs) {
|
166 |
printf("%s: There's no input %i\n", __FUNCTION__, line);
|
167 |
return;
|
168 |
} |
169 |
|
170 |
s->input[line] = value; |
171 |
} |