sm501: Add missing arbitration control register
[qemu.git] / hw / i2c / smbus.c
1 /*
2 * QEMU SMBus device emulation.
3 *
4 * Copyright (c) 2007 CodeSourcery.
5 * Written by Paul Brook
6 *
7 * This code is licensed under the LGPL.
8 */
9
10 /* TODO: Implement PEC. */
11
12 #include "qemu/osdep.h"
13 #include "hw/hw.h"
14 #include "hw/i2c/i2c.h"
15 #include "hw/i2c/smbus.h"
16
17 //#define DEBUG_SMBUS 1
18
19 #ifdef DEBUG_SMBUS
20 #define DPRINTF(fmt, ...) \
21 do { printf("smbus(%02x): " fmt , dev->i2c.address, ## __VA_ARGS__); } while (0)
22 #define BADF(fmt, ...) \
23 do { fprintf(stderr, "smbus: error: " fmt , ## __VA_ARGS__); exit(1);} while (0)
24 #else
25 #define DPRINTF(fmt, ...) do {} while(0)
26 #define BADF(fmt, ...) \
27 do { fprintf(stderr, "smbus: error: " fmt , ## __VA_ARGS__);} while (0)
28 #endif
29
30 enum {
31 SMBUS_IDLE,
32 SMBUS_WRITE_DATA,
33 SMBUS_RECV_BYTE,
34 SMBUS_READ_DATA,
35 SMBUS_DONE,
36 SMBUS_CONFUSED = -1
37 };
38
39 static void smbus_do_quick_cmd(SMBusDevice *dev, int recv)
40 {
41 SMBusDeviceClass *sc = SMBUS_DEVICE_GET_CLASS(dev);
42
43 DPRINTF("Quick Command %d\n", recv);
44 if (sc->quick_cmd) {
45 sc->quick_cmd(dev, recv);
46 }
47 }
48
49 static void smbus_do_write(SMBusDevice *dev)
50 {
51 SMBusDeviceClass *sc = SMBUS_DEVICE_GET_CLASS(dev);
52
53 if (dev->data_len == 0) {
54 smbus_do_quick_cmd(dev, 0);
55 } else if (dev->data_len == 1) {
56 DPRINTF("Send Byte\n");
57 if (sc->send_byte) {
58 sc->send_byte(dev, dev->data_buf[0]);
59 }
60 } else {
61 dev->command = dev->data_buf[0];
62 DPRINTF("Command %d len %d\n", dev->command, dev->data_len - 1);
63 if (sc->write_data) {
64 sc->write_data(dev, dev->command, dev->data_buf + 1,
65 dev->data_len - 1);
66 }
67 }
68 }
69
70 static int smbus_i2c_event(I2CSlave *s, enum i2c_event event)
71 {
72 SMBusDevice *dev = SMBUS_DEVICE(s);
73
74 switch (event) {
75 case I2C_START_SEND:
76 switch (dev->mode) {
77 case SMBUS_IDLE:
78 DPRINTF("Incoming data\n");
79 dev->mode = SMBUS_WRITE_DATA;
80 break;
81 default:
82 BADF("Unexpected send start condition in state %d\n", dev->mode);
83 dev->mode = SMBUS_CONFUSED;
84 break;
85 }
86 break;
87
88 case I2C_START_RECV:
89 switch (dev->mode) {
90 case SMBUS_IDLE:
91 DPRINTF("Read mode\n");
92 dev->mode = SMBUS_RECV_BYTE;
93 break;
94 case SMBUS_WRITE_DATA:
95 if (dev->data_len == 0) {
96 BADF("Read after write with no data\n");
97 dev->mode = SMBUS_CONFUSED;
98 } else {
99 if (dev->data_len > 1) {
100 smbus_do_write(dev);
101 } else {
102 dev->command = dev->data_buf[0];
103 DPRINTF("%02x: Command %d\n", dev->i2c.address,
104 dev->command);
105 }
106 DPRINTF("Read mode\n");
107 dev->data_len = 0;
108 dev->mode = SMBUS_READ_DATA;
109 }
110 break;
111 default:
112 BADF("Unexpected recv start condition in state %d\n", dev->mode);
113 dev->mode = SMBUS_CONFUSED;
114 break;
115 }
116 break;
117
118 case I2C_FINISH:
119 switch (dev->mode) {
120 case SMBUS_WRITE_DATA:
121 smbus_do_write(dev);
122 break;
123 case SMBUS_RECV_BYTE:
124 smbus_do_quick_cmd(dev, 1);
125 break;
126 case SMBUS_READ_DATA:
127 BADF("Unexpected stop during receive\n");
128 break;
129 default:
130 /* Nothing to do. */
131 break;
132 }
133 dev->mode = SMBUS_IDLE;
134 dev->data_len = 0;
135 break;
136
137 case I2C_NACK:
138 switch (dev->mode) {
139 case SMBUS_DONE:
140 /* Nothing to do. */
141 break;
142 case SMBUS_READ_DATA:
143 dev->mode = SMBUS_DONE;
144 break;
145 default:
146 BADF("Unexpected NACK in state %d\n", dev->mode);
147 dev->mode = SMBUS_CONFUSED;
148 break;
149 }
150 }
151
152 return 0;
153 }
154
155 static int smbus_i2c_recv(I2CSlave *s)
156 {
157 SMBusDevice *dev = SMBUS_DEVICE(s);
158 SMBusDeviceClass *sc = SMBUS_DEVICE_GET_CLASS(dev);
159 int ret;
160
161 switch (dev->mode) {
162 case SMBUS_RECV_BYTE:
163 if (sc->receive_byte) {
164 ret = sc->receive_byte(dev);
165 } else {
166 ret = 0;
167 }
168 DPRINTF("Receive Byte %02x\n", ret);
169 dev->mode = SMBUS_DONE;
170 break;
171 case SMBUS_READ_DATA:
172 if (sc->read_data) {
173 ret = sc->read_data(dev, dev->command, dev->data_len);
174 dev->data_len++;
175 } else {
176 ret = 0;
177 }
178 DPRINTF("Read data %02x\n", ret);
179 break;
180 default:
181 BADF("Unexpected read in state %d\n", dev->mode);
182 dev->mode = SMBUS_CONFUSED;
183 ret = 0;
184 break;
185 }
186 return ret;
187 }
188
189 static int smbus_i2c_send(I2CSlave *s, uint8_t data)
190 {
191 SMBusDevice *dev = SMBUS_DEVICE(s);
192
193 switch (dev->mode) {
194 case SMBUS_WRITE_DATA:
195 DPRINTF("Write data %02x\n", data);
196 dev->data_buf[dev->data_len++] = data;
197 break;
198 default:
199 BADF("Unexpected write in state %d\n", dev->mode);
200 break;
201 }
202 return 0;
203 }
204
205 static int smbus_device_init(I2CSlave *i2c)
206 {
207 SMBusDevice *dev = SMBUS_DEVICE(i2c);
208 SMBusDeviceClass *sc = SMBUS_DEVICE_GET_CLASS(dev);
209
210 return sc->init(dev);
211 }
212
213 /* Master device commands. */
214 int smbus_quick_command(I2CBus *bus, uint8_t addr, int read)
215 {
216 if (i2c_start_transfer(bus, addr, read)) {
217 return -1;
218 }
219 i2c_end_transfer(bus);
220 return 0;
221 }
222
223 int smbus_receive_byte(I2CBus *bus, uint8_t addr)
224 {
225 uint8_t data;
226
227 if (i2c_start_transfer(bus, addr, 1)) {
228 return -1;
229 }
230 data = i2c_recv(bus);
231 i2c_nack(bus);
232 i2c_end_transfer(bus);
233 return data;
234 }
235
236 int smbus_send_byte(I2CBus *bus, uint8_t addr, uint8_t data)
237 {
238 if (i2c_start_transfer(bus, addr, 0)) {
239 return -1;
240 }
241 i2c_send(bus, data);
242 i2c_end_transfer(bus);
243 return 0;
244 }
245
246 int smbus_read_byte(I2CBus *bus, uint8_t addr, uint8_t command)
247 {
248 uint8_t data;
249 if (i2c_start_transfer(bus, addr, 0)) {
250 return -1;
251 }
252 i2c_send(bus, command);
253 if (i2c_start_transfer(bus, addr, 1)) {
254 i2c_end_transfer(bus);
255 return -1;
256 }
257 data = i2c_recv(bus);
258 i2c_nack(bus);
259 i2c_end_transfer(bus);
260 return data;
261 }
262
263 int smbus_write_byte(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t data)
264 {
265 if (i2c_start_transfer(bus, addr, 0)) {
266 return -1;
267 }
268 i2c_send(bus, command);
269 i2c_send(bus, data);
270 i2c_end_transfer(bus);
271 return 0;
272 }
273
274 int smbus_read_word(I2CBus *bus, uint8_t addr, uint8_t command)
275 {
276 uint16_t data;
277 if (i2c_start_transfer(bus, addr, 0)) {
278 return -1;
279 }
280 i2c_send(bus, command);
281 if (i2c_start_transfer(bus, addr, 1)) {
282 i2c_end_transfer(bus);
283 return -1;
284 }
285 data = i2c_recv(bus);
286 data |= i2c_recv(bus) << 8;
287 i2c_nack(bus);
288 i2c_end_transfer(bus);
289 return data;
290 }
291
292 int smbus_write_word(I2CBus *bus, uint8_t addr, uint8_t command, uint16_t data)
293 {
294 if (i2c_start_transfer(bus, addr, 0)) {
295 return -1;
296 }
297 i2c_send(bus, command);
298 i2c_send(bus, data & 0xff);
299 i2c_send(bus, data >> 8);
300 i2c_end_transfer(bus);
301 return 0;
302 }
303
304 int smbus_read_block(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t *data)
305 {
306 int len;
307 int i;
308
309 if (i2c_start_transfer(bus, addr, 0)) {
310 return -1;
311 }
312 i2c_send(bus, command);
313 if (i2c_start_transfer(bus, addr, 1)) {
314 i2c_end_transfer(bus);
315 return -1;
316 }
317 len = i2c_recv(bus);
318 if (len > 32) {
319 len = 0;
320 }
321 for (i = 0; i < len; i++) {
322 data[i] = i2c_recv(bus);
323 }
324 i2c_nack(bus);
325 i2c_end_transfer(bus);
326 return len;
327 }
328
329 int smbus_write_block(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t *data,
330 int len)
331 {
332 int i;
333
334 if (len > 32)
335 len = 32;
336
337 if (i2c_start_transfer(bus, addr, 0)) {
338 return -1;
339 }
340 i2c_send(bus, command);
341 i2c_send(bus, len);
342 for (i = 0; i < len; i++) {
343 i2c_send(bus, data[i]);
344 }
345 i2c_end_transfer(bus);
346 return 0;
347 }
348
349 static void smbus_device_class_init(ObjectClass *klass, void *data)
350 {
351 I2CSlaveClass *sc = I2C_SLAVE_CLASS(klass);
352
353 sc->init = smbus_device_init;
354 sc->event = smbus_i2c_event;
355 sc->recv = smbus_i2c_recv;
356 sc->send = smbus_i2c_send;
357 }
358
359 static const TypeInfo smbus_device_type_info = {
360 .name = TYPE_SMBUS_DEVICE,
361 .parent = TYPE_I2C_SLAVE,
362 .instance_size = sizeof(SMBusDevice),
363 .abstract = true,
364 .class_size = sizeof(SMBusDeviceClass),
365 .class_init = smbus_device_class_init,
366 };
367
368 static void smbus_device_register_types(void)
369 {
370 type_register_static(&smbus_device_type_info);
371 }
372
373 type_init(smbus_device_register_types)