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10#include "qemu/osdep.h"
11#include "hw/i2c/i2c.h"
12#include "qemu/module.h"
13
14#define TYPE_MAX7310 "max7310"
15#define MAX7310(obj) OBJECT_CHECK(MAX7310State, (obj), TYPE_MAX7310)
16
17typedef struct MAX7310State {
18 I2CSlave parent_obj;
19
20 int i2c_command_byte;
21 int len;
22
23 uint8_t level;
24 uint8_t direction;
25 uint8_t polarity;
26 uint8_t status;
27 uint8_t command;
28 qemu_irq handler[8];
29 qemu_irq *gpio_in;
30} MAX7310State;
31
32static void max7310_reset(DeviceState *dev)
33{
34 MAX7310State *s = MAX7310(dev);
35
36 s->level &= s->direction;
37 s->direction = 0xff;
38 s->polarity = 0xf0;
39 s->status = 0x01;
40 s->command = 0x00;
41}
42
43static uint8_t max7310_rx(I2CSlave *i2c)
44{
45 MAX7310State *s = MAX7310(i2c);
46
47 switch (s->command) {
48 case 0x00:
49 return s->level ^ s->polarity;
50 break;
51
52 case 0x01:
53 return s->level & ~s->direction;
54 break;
55
56 case 0x02:
57 return s->polarity;
58
59 case 0x03:
60 return s->direction;
61
62 case 0x04:
63 return s->status;
64 break;
65
66 case 0xff:
67 return 0xff;
68
69 default:
70#ifdef VERBOSE
71 printf("%s: unknown register %02x\n", __func__, s->command);
72#endif
73 break;
74 }
75 return 0xff;
76}
77
78static int max7310_tx(I2CSlave *i2c, uint8_t data)
79{
80 MAX7310State *s = MAX7310(i2c);
81 uint8_t diff;
82 int line;
83
84 if (s->len ++ > 1) {
85#ifdef VERBOSE
86 printf("%s: message too long (%i bytes)\n", __func__, s->len);
87#endif
88 return 1;
89 }
90
91 if (s->i2c_command_byte) {
92 s->command = data;
93 s->i2c_command_byte = 0;
94 return 0;
95 }
96
97 switch (s->command) {
98 case 0x01:
99 for (diff = (data ^ s->level) & ~s->direction; diff;
100 diff &= ~(1 << line)) {
101 line = ctz32(diff);
102 if (s->handler[line])
103 qemu_set_irq(s->handler[line], (data >> line) & 1);
104 }
105 s->level = (s->level & s->direction) | (data & ~s->direction);
106 break;
107
108 case 0x02:
109 s->polarity = data;
110 break;
111
112 case 0x03:
113 s->level &= ~(s->direction ^ data);
114 s->direction = data;
115 break;
116
117 case 0x04:
118 s->status = data;
119 break;
120
121 case 0x00:
122 break;
123 default:
124#ifdef VERBOSE
125 printf("%s: unknown register %02x\n", __func__, s->command);
126#endif
127 return 1;
128 }
129
130 return 0;
131}
132
133static int max7310_event(I2CSlave *i2c, enum i2c_event event)
134{
135 MAX7310State *s = MAX7310(i2c);
136 s->len = 0;
137
138 switch (event) {
139 case I2C_START_SEND:
140 s->i2c_command_byte = 1;
141 break;
142 case I2C_FINISH:
143#ifdef VERBOSE
144 if (s->len == 1)
145 printf("%s: message too short (%i bytes)\n", __func__, s->len);
146#endif
147 break;
148 default:
149 break;
150 }
151
152 return 0;
153}
154
155static const VMStateDescription vmstate_max7310 = {
156 .name = "max7310",
157 .version_id = 0,
158 .minimum_version_id = 0,
159 .fields = (VMStateField[]) {
160 VMSTATE_INT32(i2c_command_byte, MAX7310State),
161 VMSTATE_INT32(len, MAX7310State),
162 VMSTATE_UINT8(level, MAX7310State),
163 VMSTATE_UINT8(direction, MAX7310State),
164 VMSTATE_UINT8(polarity, MAX7310State),
165 VMSTATE_UINT8(status, MAX7310State),
166 VMSTATE_UINT8(command, MAX7310State),
167 VMSTATE_I2C_SLAVE(parent_obj, MAX7310State),
168 VMSTATE_END_OF_LIST()
169 }
170};
171
172static void max7310_gpio_set(void *opaque, int line, int level)
173{
174 MAX7310State *s = (MAX7310State *) opaque;
175 if (line >= ARRAY_SIZE(s->handler) || line < 0)
176 hw_error("bad GPIO line");
177
178 if (level)
179 s->level |= s->direction & (1 << line);
180 else
181 s->level &= ~(s->direction & (1 << line));
182}
183
184
185
186static void max7310_realize(DeviceState *dev, Error **errp)
187{
188 I2CSlave *i2c = I2C_SLAVE(dev);
189 MAX7310State *s = MAX7310(dev);
190
191 qdev_init_gpio_in(&i2c->qdev, max7310_gpio_set, 8);
192 qdev_init_gpio_out(&i2c->qdev, s->handler, 8);
193}
194
195static void max7310_class_init(ObjectClass *klass, void *data)
196{
197 DeviceClass *dc = DEVICE_CLASS(klass);
198 I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
199
200 dc->realize = max7310_realize;
201 k->event = max7310_event;
202 k->recv = max7310_rx;
203 k->send = max7310_tx;
204 dc->reset = max7310_reset;
205 dc->vmsd = &vmstate_max7310;
206}
207
208static const TypeInfo max7310_info = {
209 .name = TYPE_MAX7310,
210 .parent = TYPE_I2C_SLAVE,
211 .instance_size = sizeof(MAX7310State),
212 .class_init = max7310_class_init,
213};
214
215static void max7310_register_types(void)
216{
217 type_register_static(&max7310_info);
218}
219
220type_init(max7310_register_types)
221