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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) |