root / hw / max7310.c @ 59d94130
History | View | Annotate | Download (5.1 kB)
1 |
/*
|
---|---|
2 |
* MAX7310 8-port GPIO expansion chip.
|
3 |
*
|
4 |
* Copyright (c) 2006 Openedhand Ltd.
|
5 |
* Written by Andrzej Zaborowski <balrog@zabor.org>
|
6 |
*
|
7 |
* This file is licensed under GNU GPL.
|
8 |
*/
|
9 |
|
10 |
#include "hw.h" |
11 |
#include "i2c.h" |
12 |
|
13 |
struct max7310_s {
|
14 |
i2c_slave i2c; |
15 |
int i2c_command_byte;
|
16 |
int len;
|
17 |
|
18 |
uint8_t level; |
19 |
uint8_t direction; |
20 |
uint8_t polarity; |
21 |
uint8_t status; |
22 |
uint8_t command; |
23 |
qemu_irq handler[8];
|
24 |
qemu_irq *gpio_in; |
25 |
}; |
26 |
|
27 |
void max7310_reset(i2c_slave *i2c)
|
28 |
{ |
29 |
struct max7310_s *s = (struct max7310_s *) i2c; |
30 |
s->level &= s->direction; |
31 |
s->direction = 0xff;
|
32 |
s->polarity = 0xf0;
|
33 |
s->status = 0x01;
|
34 |
s->command = 0x00;
|
35 |
} |
36 |
|
37 |
static int max7310_rx(i2c_slave *i2c) |
38 |
{ |
39 |
struct max7310_s *s = (struct max7310_s *) i2c; |
40 |
|
41 |
switch (s->command) {
|
42 |
case 0x00: /* Input port */ |
43 |
return s->level ^ s->polarity;
|
44 |
break;
|
45 |
|
46 |
case 0x01: /* Output port */ |
47 |
return s->level & ~s->direction;
|
48 |
break;
|
49 |
|
50 |
case 0x02: /* Polarity inversion */ |
51 |
return s->polarity;
|
52 |
|
53 |
case 0x03: /* Configuration */ |
54 |
return s->direction;
|
55 |
|
56 |
case 0x04: /* Timeout */ |
57 |
return s->status;
|
58 |
break;
|
59 |
|
60 |
case 0xff: /* Reserved */ |
61 |
return 0xff; |
62 |
|
63 |
default:
|
64 |
#ifdef VERBOSE
|
65 |
printf("%s: unknown register %02x\n", __FUNCTION__, s->command);
|
66 |
#endif
|
67 |
break;
|
68 |
} |
69 |
return 0xff; |
70 |
} |
71 |
|
72 |
static int max7310_tx(i2c_slave *i2c, uint8_t data) |
73 |
{ |
74 |
struct max7310_s *s = (struct max7310_s *) i2c; |
75 |
uint8_t diff; |
76 |
int line;
|
77 |
|
78 |
if (s->len ++ > 1) { |
79 |
#ifdef VERBOSE
|
80 |
printf("%s: message too long (%i bytes)\n", __FUNCTION__, s->len);
|
81 |
#endif
|
82 |
return 1; |
83 |
} |
84 |
|
85 |
if (s->i2c_command_byte) {
|
86 |
s->command = data; |
87 |
s->i2c_command_byte = 0;
|
88 |
return 0; |
89 |
} |
90 |
|
91 |
switch (s->command) {
|
92 |
case 0x01: /* Output port */ |
93 |
for (diff = (data ^ s->level) & ~s->direction; diff;
|
94 |
diff &= ~(1 << line)) {
|
95 |
line = ffs(diff) - 1;
|
96 |
if (s->handler[line])
|
97 |
qemu_set_irq(s->handler[line], (data >> line) & 1);
|
98 |
} |
99 |
s->level = (s->level & s->direction) | (data & ~s->direction); |
100 |
break;
|
101 |
|
102 |
case 0x02: /* Polarity inversion */ |
103 |
s->polarity = data; |
104 |
break;
|
105 |
|
106 |
case 0x03: /* Configuration */ |
107 |
s->level &= ~(s->direction ^ data); |
108 |
s->direction = data; |
109 |
break;
|
110 |
|
111 |
case 0x04: /* Timeout */ |
112 |
s->status = data; |
113 |
break;
|
114 |
|
115 |
case 0x00: /* Input port - ignore writes */ |
116 |
break;
|
117 |
default:
|
118 |
#ifdef VERBOSE
|
119 |
printf("%s: unknown register %02x\n", __FUNCTION__, s->command);
|
120 |
#endif
|
121 |
return 1; |
122 |
} |
123 |
|
124 |
return 0; |
125 |
} |
126 |
|
127 |
static void max7310_event(i2c_slave *i2c, enum i2c_event event) |
128 |
{ |
129 |
struct max7310_s *s = (struct max7310_s *) i2c; |
130 |
s->len = 0;
|
131 |
|
132 |
switch (event) {
|
133 |
case I2C_START_SEND:
|
134 |
s->i2c_command_byte = 1;
|
135 |
break;
|
136 |
case I2C_FINISH:
|
137 |
#ifdef VERBOSE
|
138 |
if (s->len == 1) |
139 |
printf("%s: message too short (%i bytes)\n", __FUNCTION__, s->len);
|
140 |
#endif
|
141 |
break;
|
142 |
default:
|
143 |
break;
|
144 |
} |
145 |
} |
146 |
|
147 |
static void max7310_save(QEMUFile *f, void *opaque) |
148 |
{ |
149 |
struct max7310_s *s = (struct max7310_s *) opaque; |
150 |
|
151 |
qemu_put_be32(f, s->i2c_command_byte); |
152 |
qemu_put_be32(f, s->len); |
153 |
|
154 |
qemu_put_8s(f, &s->level); |
155 |
qemu_put_8s(f, &s->direction); |
156 |
qemu_put_8s(f, &s->polarity); |
157 |
qemu_put_8s(f, &s->status); |
158 |
qemu_put_8s(f, &s->command); |
159 |
|
160 |
i2c_slave_save(f, &s->i2c); |
161 |
} |
162 |
|
163 |
static int max7310_load(QEMUFile *f, void *opaque, int version_id) |
164 |
{ |
165 |
struct max7310_s *s = (struct max7310_s *) opaque; |
166 |
|
167 |
s->i2c_command_byte = qemu_get_be32(f); |
168 |
s->len = qemu_get_be32(f); |
169 |
|
170 |
qemu_get_8s(f, &s->level); |
171 |
qemu_get_8s(f, &s->direction); |
172 |
qemu_get_8s(f, &s->polarity); |
173 |
qemu_get_8s(f, &s->status); |
174 |
qemu_get_8s(f, &s->command); |
175 |
|
176 |
i2c_slave_load(f, &s->i2c); |
177 |
return 0; |
178 |
} |
179 |
|
180 |
static void max7310_gpio_set(void *opaque, int line, int level) |
181 |
{ |
182 |
struct max7310_s *s = (struct max7310_s *) opaque; |
183 |
if (line >= ARRAY_SIZE(s->handler) || line < 0) |
184 |
hw_error("bad GPIO line");
|
185 |
|
186 |
if (level)
|
187 |
s->level |= s->direction & (1 << line);
|
188 |
else
|
189 |
s->level &= ~(s->direction & (1 << line));
|
190 |
} |
191 |
|
192 |
/* MAX7310 is SMBus-compatible (can be used with only SMBus protocols),
|
193 |
* but also accepts sequences that are not SMBus so return an I2C device. */
|
194 |
struct i2c_slave *max7310_init(i2c_bus *bus)
|
195 |
{ |
196 |
struct max7310_s *s = (struct max7310_s *) |
197 |
i2c_slave_init(bus, 0, sizeof(struct max7310_s)); |
198 |
s->i2c.event = max7310_event; |
199 |
s->i2c.recv = max7310_rx; |
200 |
s->i2c.send = max7310_tx; |
201 |
s->gpio_in = qemu_allocate_irqs(max7310_gpio_set, s, |
202 |
ARRAY_SIZE(s->handler)); |
203 |
|
204 |
max7310_reset(&s->i2c); |
205 |
|
206 |
register_savevm("max7310", -1, 0, max7310_save, max7310_load, s); |
207 |
|
208 |
return &s->i2c;
|
209 |
} |
210 |
|
211 |
qemu_irq *max7310_gpio_in_get(i2c_slave *i2c) |
212 |
{ |
213 |
struct max7310_s *s = (struct max7310_s *) i2c; |
214 |
return s->gpio_in;
|
215 |
} |
216 |
|
217 |
void max7310_gpio_out_set(i2c_slave *i2c, int line, qemu_irq handler) |
218 |
{ |
219 |
struct max7310_s *s = (struct max7310_s *) i2c; |
220 |
if (line >= ARRAY_SIZE(s->handler) || line < 0) |
221 |
hw_error("bad GPIO line");
|
222 |
|
223 |
s->handler[line] = handler; |
224 |
} |