linux-user: stack_base is now mandatory on all targets
[qemu.git] / hw / max7310.c
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 "i2c.h"
11
12 typedef struct {
13 I2CSlave i2c;
14 int i2c_command_byte;
15 int len;
16
17 uint8_t level;
18 uint8_t direction;
19 uint8_t polarity;
20 uint8_t status;
21 uint8_t command;
22 qemu_irq handler[8];
23 qemu_irq *gpio_in;
24 } MAX7310State;
25
26 static void max7310_reset(DeviceState *dev)
27 {
28 MAX7310State *s = FROM_I2C_SLAVE(MAX7310State, I2C_SLAVE_FROM_QDEV(dev));
29 s->level &= s->direction;
30 s->direction = 0xff;
31 s->polarity = 0xf0;
32 s->status = 0x01;
33 s->command = 0x00;
34 }
35
36 static int max7310_rx(I2CSlave *i2c)
37 {
38 MAX7310State *s = (MAX7310State *) i2c;
39
40 switch (s->command) {
41 case 0x00: /* Input port */
42 return s->level ^ s->polarity;
43 break;
44
45 case 0x01: /* Output port */
46 return s->level & ~s->direction;
47 break;
48
49 case 0x02: /* Polarity inversion */
50 return s->polarity;
51
52 case 0x03: /* Configuration */
53 return s->direction;
54
55 case 0x04: /* Timeout */
56 return s->status;
57 break;
58
59 case 0xff: /* Reserved */
60 return 0xff;
61
62 default:
63 #ifdef VERBOSE
64 printf("%s: unknown register %02x\n", __FUNCTION__, s->command);
65 #endif
66 break;
67 }
68 return 0xff;
69 }
70
71 static int max7310_tx(I2CSlave *i2c, uint8_t data)
72 {
73 MAX7310State *s = (MAX7310State *) i2c;
74 uint8_t diff;
75 int line;
76
77 if (s->len ++ > 1) {
78 #ifdef VERBOSE
79 printf("%s: message too long (%i bytes)\n", __FUNCTION__, s->len);
80 #endif
81 return 1;
82 }
83
84 if (s->i2c_command_byte) {
85 s->command = data;
86 s->i2c_command_byte = 0;
87 return 0;
88 }
89
90 switch (s->command) {
91 case 0x01: /* Output port */
92 for (diff = (data ^ s->level) & ~s->direction; diff;
93 diff &= ~(1 << line)) {
94 line = ffs(diff) - 1;
95 if (s->handler[line])
96 qemu_set_irq(s->handler[line], (data >> line) & 1);
97 }
98 s->level = (s->level & s->direction) | (data & ~s->direction);
99 break;
100
101 case 0x02: /* Polarity inversion */
102 s->polarity = data;
103 break;
104
105 case 0x03: /* Configuration */
106 s->level &= ~(s->direction ^ data);
107 s->direction = data;
108 break;
109
110 case 0x04: /* Timeout */
111 s->status = data;
112 break;
113
114 case 0x00: /* Input port - ignore writes */
115 break;
116 default:
117 #ifdef VERBOSE
118 printf("%s: unknown register %02x\n", __FUNCTION__, s->command);
119 #endif
120 return 1;
121 }
122
123 return 0;
124 }
125
126 static void max7310_event(I2CSlave *i2c, enum i2c_event event)
127 {
128 MAX7310State *s = (MAX7310State *) i2c;
129 s->len = 0;
130
131 switch (event) {
132 case I2C_START_SEND:
133 s->i2c_command_byte = 1;
134 break;
135 case I2C_FINISH:
136 #ifdef VERBOSE
137 if (s->len == 1)
138 printf("%s: message too short (%i bytes)\n", __FUNCTION__, s->len);
139 #endif
140 break;
141 default:
142 break;
143 }
144 }
145
146 static const VMStateDescription vmstate_max7310 = {
147 .name = "max7310",
148 .version_id = 0,
149 .minimum_version_id = 0,
150 .minimum_version_id_old = 0,
151 .fields = (VMStateField []) {
152 VMSTATE_INT32(i2c_command_byte, MAX7310State),
153 VMSTATE_INT32(len, MAX7310State),
154 VMSTATE_UINT8(level, MAX7310State),
155 VMSTATE_UINT8(direction, MAX7310State),
156 VMSTATE_UINT8(polarity, MAX7310State),
157 VMSTATE_UINT8(status, MAX7310State),
158 VMSTATE_UINT8(command, MAX7310State),
159 VMSTATE_I2C_SLAVE(i2c, MAX7310State),
160 VMSTATE_END_OF_LIST()
161 }
162 };
163
164 static void max7310_gpio_set(void *opaque, int line, int level)
165 {
166 MAX7310State *s = (MAX7310State *) opaque;
167 if (line >= ARRAY_SIZE(s->handler) || line < 0)
168 hw_error("bad GPIO line");
169
170 if (level)
171 s->level |= s->direction & (1 << line);
172 else
173 s->level &= ~(s->direction & (1 << line));
174 }
175
176 /* MAX7310 is SMBus-compatible (can be used with only SMBus protocols),
177 * but also accepts sequences that are not SMBus so return an I2C device. */
178 static int max7310_init(I2CSlave *i2c)
179 {
180 MAX7310State *s = FROM_I2C_SLAVE(MAX7310State, i2c);
181
182 qdev_init_gpio_in(&i2c->qdev, max7310_gpio_set, 8);
183 qdev_init_gpio_out(&i2c->qdev, s->handler, 8);
184
185 return 0;
186 }
187
188 static void max7310_class_init(ObjectClass *klass, void *data)
189 {
190 I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
191
192 k->init = max7310_init;
193 k->event = max7310_event;
194 k->recv = max7310_rx;
195 k->send = max7310_tx;
196 }
197
198 static DeviceInfo max7310_info = {
199 .name = "max7310",
200 .size = sizeof(MAX7310State),
201 .vmsd = &vmstate_max7310,
202 .reset = max7310_reset,
203 .class_init = max7310_class_init,
204 };
205
206 static void max7310_register_devices(void)
207 {
208 i2c_register_slave(&max7310_info);
209 }
210
211 device_init(max7310_register_devices)