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12#include "qemu/osdep.h"
13#include "hw/hw.h"
14#include "hw/i2c/i2c.h"
15#include "hw/i2c/smbus.h"
16
17
18
19#ifdef DEBUG_SMBUS
20#define DPRINTF(fmt, ...) \
21do { printf("smbus(%02x): " fmt , dev->i2c.address, ## __VA_ARGS__); } while (0)
22#define BADF(fmt, ...) \
23do { fprintf(stderr, "smbus: error: " fmt , ## __VA_ARGS__); exit(1);} while (0)
24#else
25#define DPRINTF(fmt, ...) do {} while(0)
26#define BADF(fmt, ...) \
27do { fprintf(stderr, "smbus: error: " fmt , ## __VA_ARGS__);} while (0)
28#endif
29
30enum {
31 SMBUS_IDLE,
32 SMBUS_WRITE_DATA,
33 SMBUS_RECV_BYTE,
34 SMBUS_READ_DATA,
35 SMBUS_DONE,
36 SMBUS_CONFUSED = -1
37};
38
39static 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
49static 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
70static 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
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
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
155static 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
189static 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
206int smbus_quick_command(I2CBus *bus, uint8_t addr, int read)
207{
208 if (i2c_start_transfer(bus, addr, read)) {
209 return -1;
210 }
211 i2c_end_transfer(bus);
212 return 0;
213}
214
215int smbus_receive_byte(I2CBus *bus, uint8_t addr)
216{
217 uint8_t data;
218
219 if (i2c_start_transfer(bus, addr, 1)) {
220 return -1;
221 }
222 data = i2c_recv(bus);
223 i2c_nack(bus);
224 i2c_end_transfer(bus);
225 return data;
226}
227
228int smbus_send_byte(I2CBus *bus, uint8_t addr, uint8_t data)
229{
230 if (i2c_start_transfer(bus, addr, 0)) {
231 return -1;
232 }
233 i2c_send(bus, data);
234 i2c_end_transfer(bus);
235 return 0;
236}
237
238int smbus_read_byte(I2CBus *bus, uint8_t addr, uint8_t command)
239{
240 uint8_t data;
241 if (i2c_start_transfer(bus, addr, 0)) {
242 return -1;
243 }
244 i2c_send(bus, command);
245 if (i2c_start_transfer(bus, addr, 1)) {
246 i2c_end_transfer(bus);
247 return -1;
248 }
249 data = i2c_recv(bus);
250 i2c_nack(bus);
251 i2c_end_transfer(bus);
252 return data;
253}
254
255int smbus_write_byte(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t data)
256{
257 if (i2c_start_transfer(bus, addr, 0)) {
258 return -1;
259 }
260 i2c_send(bus, command);
261 i2c_send(bus, data);
262 i2c_end_transfer(bus);
263 return 0;
264}
265
266int smbus_read_word(I2CBus *bus, uint8_t addr, uint8_t command)
267{
268 uint16_t data;
269 if (i2c_start_transfer(bus, addr, 0)) {
270 return -1;
271 }
272 i2c_send(bus, command);
273 if (i2c_start_transfer(bus, addr, 1)) {
274 i2c_end_transfer(bus);
275 return -1;
276 }
277 data = i2c_recv(bus);
278 data |= i2c_recv(bus) << 8;
279 i2c_nack(bus);
280 i2c_end_transfer(bus);
281 return data;
282}
283
284int smbus_write_word(I2CBus *bus, uint8_t addr, uint8_t command, uint16_t data)
285{
286 if (i2c_start_transfer(bus, addr, 0)) {
287 return -1;
288 }
289 i2c_send(bus, command);
290 i2c_send(bus, data & 0xff);
291 i2c_send(bus, data >> 8);
292 i2c_end_transfer(bus);
293 return 0;
294}
295
296int smbus_read_block(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t *data)
297{
298 int len;
299 int i;
300
301 if (i2c_start_transfer(bus, addr, 0)) {
302 return -1;
303 }
304 i2c_send(bus, command);
305 if (i2c_start_transfer(bus, addr, 1)) {
306 i2c_end_transfer(bus);
307 return -1;
308 }
309 len = i2c_recv(bus);
310 if (len > 32) {
311 len = 0;
312 }
313 for (i = 0; i < len; i++) {
314 data[i] = i2c_recv(bus);
315 }
316 i2c_nack(bus);
317 i2c_end_transfer(bus);
318 return len;
319}
320
321int smbus_write_block(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t *data,
322 int len)
323{
324 int i;
325
326 if (len > 32)
327 len = 32;
328
329 if (i2c_start_transfer(bus, addr, 0)) {
330 return -1;
331 }
332 i2c_send(bus, command);
333 i2c_send(bus, len);
334 for (i = 0; i < len; i++) {
335 i2c_send(bus, data[i]);
336 }
337 i2c_end_transfer(bus);
338 return 0;
339}
340
341static void smbus_device_class_init(ObjectClass *klass, void *data)
342{
343 I2CSlaveClass *sc = I2C_SLAVE_CLASS(klass);
344
345 sc->event = smbus_i2c_event;
346 sc->recv = smbus_i2c_recv;
347 sc->send = smbus_i2c_send;
348}
349
350static const TypeInfo smbus_device_type_info = {
351 .name = TYPE_SMBUS_DEVICE,
352 .parent = TYPE_I2C_SLAVE,
353 .instance_size = sizeof(SMBusDevice),
354 .abstract = true,
355 .class_size = sizeof(SMBusDeviceClass),
356 .class_init = smbus_device_class_init,
357};
358
359static void smbus_device_register_types(void)
360{
361 type_register_static(&smbus_device_type_info);
362}
363
364type_init(smbus_device_register_types)
365
