xref: /openbmc/qemu/hw/adc/max111x.c (revision 99367627)
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  * Contributions after 2012-01-13 are licensed under the terms of the
10  * GNU GPL, version 2 or (at your option) any later version.
11  */
12 
13 #include "qemu/osdep.h"
14 #include "hw/adc/max111x.h"
15 #include "hw/irq.h"
16 #include "migration/vmstate.h"
17 #include "qemu/module.h"
18 #include "hw/qdev-properties.h"
19 
20 /* Control-byte bitfields */
21 #define CB_PD0		(1 << 0)
22 #define CB_PD1		(1 << 1)
23 #define CB_SGL		(1 << 2)
24 #define CB_UNI		(1 << 3)
25 #define CB_SEL0		(1 << 4)
26 #define CB_SEL1		(1 << 5)
27 #define CB_SEL2		(1 << 6)
28 #define CB_START	(1 << 7)
29 
30 #define CHANNEL_NUM(v, b0, b1, b2)	\
31                         ((((v) >> (2 + (b0))) & 4) |	\
32                          (((v) >> (3 + (b1))) & 2) |	\
33                          (((v) >> (4 + (b2))) & 1))
34 
max111x_read(MAX111xState * s)35 static uint32_t max111x_read(MAX111xState *s)
36 {
37     if (!s->tb1)
38         return 0;
39 
40     switch (s->cycle ++) {
41     case 1:
42         return s->rb2;
43     case 2:
44         return s->rb3;
45     }
46 
47     return 0;
48 }
49 
50 /* Interpret a control-byte */
max111x_write(MAX111xState * s,uint32_t value)51 static void max111x_write(MAX111xState *s, uint32_t value)
52 {
53     int measure, chan;
54 
55     /* Ignore the value if START bit is zero */
56     if (!(value & CB_START))
57         return;
58 
59     s->cycle = 0;
60 
61     if (!(value & CB_PD1)) {
62         s->tb1 = 0;
63         return;
64     }
65 
66     s->tb1 = value;
67 
68     if (s->inputs == 8)
69         chan = CHANNEL_NUM(value, 1, 0, 2);
70     else
71         chan = CHANNEL_NUM(value & ~CB_SEL0, 0, 1, 2);
72 
73     if (value & CB_SGL)
74         measure = s->input[chan] - s->com;
75     else
76         measure = s->input[chan] - s->input[chan ^ 1];
77 
78     if (!(value & CB_UNI))
79         measure ^= 0x80;
80 
81     s->rb2 = (measure >> 2) & 0x3f;
82     s->rb3 = (measure << 6) & 0xc0;
83 
84     /* FIXME: When should the IRQ be lowered?  */
85     qemu_irq_raise(s->interrupt);
86 }
87 
max111x_transfer(SSIPeripheral * dev,uint32_t value)88 static uint32_t max111x_transfer(SSIPeripheral *dev, uint32_t value)
89 {
90     MAX111xState *s = MAX_111X(dev);
91     max111x_write(s, value);
92     return max111x_read(s);
93 }
94 
95 static const VMStateDescription vmstate_max111x = {
96     .name = "max111x",
97     .version_id = 1,
98     .minimum_version_id = 1,
99     .fields = (const VMStateField[]) {
100         VMSTATE_SSI_PERIPHERAL(parent_obj, MAX111xState),
101         VMSTATE_UINT8(tb1, MAX111xState),
102         VMSTATE_UINT8(rb2, MAX111xState),
103         VMSTATE_UINT8(rb3, MAX111xState),
104         VMSTATE_INT32_EQUAL(inputs, MAX111xState, NULL),
105         VMSTATE_INT32(com, MAX111xState),
106         VMSTATE_ARRAY_INT32_UNSAFE(input, MAX111xState, inputs,
107                                    vmstate_info_uint8, uint8_t),
108         VMSTATE_END_OF_LIST()
109     }
110 };
111 
max111x_input_set(void * opaque,int line,int value)112 static void max111x_input_set(void *opaque, int line, int value)
113 {
114     MAX111xState *s = MAX_111X(opaque);
115 
116     assert(line >= 0 && line < s->inputs);
117     s->input[line] = value;
118 }
119 
max111x_init(SSIPeripheral * d,int inputs)120 static int max111x_init(SSIPeripheral *d, int inputs)
121 {
122     DeviceState *dev = DEVICE(d);
123     MAX111xState *s = MAX_111X(dev);
124 
125     qdev_init_gpio_out(dev, &s->interrupt, 1);
126     qdev_init_gpio_in(dev, max111x_input_set, inputs);
127 
128     s->inputs = inputs;
129 
130     return 0;
131 }
132 
max1110_realize(SSIPeripheral * dev,Error ** errp)133 static void max1110_realize(SSIPeripheral *dev, Error **errp)
134 {
135     max111x_init(dev, 8);
136 }
137 
max1111_realize(SSIPeripheral * dev,Error ** errp)138 static void max1111_realize(SSIPeripheral *dev, Error **errp)
139 {
140     max111x_init(dev, 4);
141 }
142 
max111x_reset(DeviceState * dev)143 static void max111x_reset(DeviceState *dev)
144 {
145     MAX111xState *s = MAX_111X(dev);
146     int i;
147 
148     for (i = 0; i < s->inputs; i++) {
149         s->input[i] = s->reset_input[i];
150     }
151     s->com = 0;
152     s->tb1 = 0;
153     s->rb2 = 0;
154     s->rb3 = 0;
155     s->cycle = 0;
156 }
157 
158 static Property max1110_properties[] = {
159     /* Reset values for ADC inputs */
160     DEFINE_PROP_UINT8("input0", MAX111xState, reset_input[0], 0xf0),
161     DEFINE_PROP_UINT8("input1", MAX111xState, reset_input[1], 0xe0),
162     DEFINE_PROP_UINT8("input2", MAX111xState, reset_input[2], 0xd0),
163     DEFINE_PROP_UINT8("input3", MAX111xState, reset_input[3], 0xc0),
164     DEFINE_PROP_END_OF_LIST(),
165 };
166 
167 static Property max1111_properties[] = {
168     /* Reset values for ADC inputs */
169     DEFINE_PROP_UINT8("input0", MAX111xState, reset_input[0], 0xf0),
170     DEFINE_PROP_UINT8("input1", MAX111xState, reset_input[1], 0xe0),
171     DEFINE_PROP_UINT8("input2", MAX111xState, reset_input[2], 0xd0),
172     DEFINE_PROP_UINT8("input3", MAX111xState, reset_input[3], 0xc0),
173     DEFINE_PROP_UINT8("input4", MAX111xState, reset_input[4], 0xb0),
174     DEFINE_PROP_UINT8("input5", MAX111xState, reset_input[5], 0xa0),
175     DEFINE_PROP_UINT8("input6", MAX111xState, reset_input[6], 0x90),
176     DEFINE_PROP_UINT8("input7", MAX111xState, reset_input[7], 0x80),
177     DEFINE_PROP_END_OF_LIST(),
178 };
179 
max111x_class_init(ObjectClass * klass,void * data)180 static void max111x_class_init(ObjectClass *klass, void *data)
181 {
182     SSIPeripheralClass *k = SSI_PERIPHERAL_CLASS(klass);
183     DeviceClass *dc = DEVICE_CLASS(klass);
184 
185     k->transfer = max111x_transfer;
186     dc->reset = max111x_reset;
187     dc->vmsd = &vmstate_max111x;
188     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
189 }
190 
191 static const TypeInfo max111x_info = {
192     .name          = TYPE_MAX_111X,
193     .parent        = TYPE_SSI_PERIPHERAL,
194     .instance_size = sizeof(MAX111xState),
195     .class_init    = max111x_class_init,
196     .abstract      = true,
197 };
198 
max1110_class_init(ObjectClass * klass,void * data)199 static void max1110_class_init(ObjectClass *klass, void *data)
200 {
201     SSIPeripheralClass *k = SSI_PERIPHERAL_CLASS(klass);
202     DeviceClass *dc = DEVICE_CLASS(klass);
203 
204     k->realize = max1110_realize;
205     device_class_set_props(dc, max1110_properties);
206 }
207 
208 static const TypeInfo max1110_info = {
209     .name          = TYPE_MAX_1110,
210     .parent        = TYPE_MAX_111X,
211     .class_init    = max1110_class_init,
212 };
213 
max1111_class_init(ObjectClass * klass,void * data)214 static void max1111_class_init(ObjectClass *klass, void *data)
215 {
216     SSIPeripheralClass *k = SSI_PERIPHERAL_CLASS(klass);
217     DeviceClass *dc = DEVICE_CLASS(klass);
218 
219     k->realize = max1111_realize;
220     device_class_set_props(dc, max1111_properties);
221 }
222 
223 static const TypeInfo max1111_info = {
224     .name          = TYPE_MAX_1111,
225     .parent        = TYPE_MAX_111X,
226     .class_init    = max1111_class_init,
227 };
228 
max111x_register_types(void)229 static void max111x_register_types(void)
230 {
231     type_register_static(&max111x_info);
232     type_register_static(&max1110_info);
233     type_register_static(&max1111_info);
234 }
235 
236 type_init(max111x_register_types)
237