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1 /*
2 * auxbus.c
3 *
4 * Copyright 2015 : GreenSocs Ltd
5 * http://www.greensocs.com/ , email: info@greensocs.com
6 *
7 * Developed by :
8 * Frederic Konrad <fred.konrad@greensocs.com>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation, either version 2 of the License, or
13 * (at your option)any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License along
21 * with this program; if not, see <http://www.gnu.org/licenses/>.
22 *
23 */
24
25 /*
26 * This is an implementation of the AUX bus for VESA Display Port v1.1a.
27 */
28
29 #include "qemu/osdep.h"
30 #include "qemu/units.h"
31 #include "qemu/log.h"
32 #include "qemu/module.h"
33 #include "hw/misc/auxbus.h"
34 #include "hw/i2c/i2c.h"
35 #include "monitor/monitor.h"
36 #include "monitor/hmp.h"
37 #include "qapi/error.h"
38
39 #ifndef DEBUG_AUX
40 #define DEBUG_AUX 0
41 #endif
42
43 #define DPRINTF(fmt, ...) do { \
44 if (DEBUG_AUX) { \
45 qemu_log("aux: " fmt , ## __VA_ARGS__); \
46 } \
47 } while (0)
48
49
50 #ifdef CONFIG_HMP
51 static void aux_slave_dev_print(MonitorHMP *hmp, DeviceState *dev, int indent);
52 #endif
53 static inline I2CBus *aux_bridge_get_i2c_bus(AUXTOI2CState *bridge);
54
55 /* aux-bus implementation (internal not public) */
56 static void aux_bus_class_init(ObjectClass *klass, const void *data)
57 {
58 #ifdef CONFIG_HMP
59 BusClass *k = BUS_CLASS(klass);
60
61 /* AUXSlave has an MMIO so we need to change the way we print information
62 * in monitor.
63 */
64 k->print_dev = aux_slave_dev_print;
65 #endif
66 }
67
68 AUXBus *aux_bus_init(DeviceState *parent, const char *name)
69 {
70 AUXBus *bus;
71 Object *auxtoi2c;
72
73 bus = AUX_BUS(qbus_new(TYPE_AUX_BUS, parent, name));
74 auxtoi2c = object_new_with_props(TYPE_AUXTOI2C, OBJECT(bus), "i2c",
75 &error_abort, NULL);
76
77 bus->bridge = AUXTOI2C(auxtoi2c);
78
79 /* Memory related. */
80 bus->aux_io = g_malloc(sizeof(*bus->aux_io));
81 memory_region_init(bus->aux_io, OBJECT(bus), "aux-io", 1 * MiB);
82 address_space_init(&bus->aux_addr_space, bus->aux_io, "aux-io");
83 return bus;
84 }
85
86 void aux_bus_realize(AUXBus *bus)
87 {
88 qdev_realize(DEVICE(bus->bridge), BUS(bus), &error_fatal);
89 }
90
91 void aux_map_slave(AUXSlave *aux_dev, hwaddr addr)
92 {
93 DeviceState *dev = DEVICE(aux_dev);
94 AUXBus *bus = AUX_BUS(qdev_get_parent_bus(dev));
95 memory_region_add_subregion(bus->aux_io, addr, aux_dev->mmio);
96 }
97
98 I2CBus *aux_get_i2c_bus(AUXBus *bus)
99 {
100 return aux_bridge_get_i2c_bus(bus->bridge);
101 }
102
103 AUXReply aux_request(AUXBus *bus, AUXCommand cmd, uint32_t address,
104 uint8_t len, uint8_t *data)
105 {
106 AUXReply ret = AUX_NACK;
107 I2CBus *i2c_bus = aux_get_i2c_bus(bus);
108 size_t i;
109
110 DPRINTF("request at address 0x%" PRIX32 ", command %u, len %u\n", address,
111 cmd, len);
112
113 switch (cmd) {
114 /*
115 * Forward the request on the AUX bus..
116 */
117 case WRITE_AUX:
118 case READ_AUX:
119 for (i = 0; i < len; i++) {
120 if (!address_space_rw(&bus->aux_addr_space, address++,
121 MEMTXATTRS_UNSPECIFIED, data++, 1,
122 cmd == WRITE_AUX)) {
123 ret = AUX_I2C_ACK;
124 } else {
125 ret = AUX_NACK;
126 break;
127 }
128 }
129 break;
130 /*
131 * Classic I2C transactions..
132 */
133 case READ_I2C:
134 if (i2c_bus_busy(i2c_bus)) {
135 i2c_end_transfer(i2c_bus);
136 }
137
138 if (i2c_start_recv(i2c_bus, address)) {
139 ret = AUX_I2C_NACK;
140 break;
141 }
142
143 ret = AUX_I2C_ACK;
144 for (i = 0; i < len; i++) {
145 data[i] = i2c_recv(i2c_bus);
146 }
147 i2c_end_transfer(i2c_bus);
148 break;
149 case WRITE_I2C:
150 if (i2c_bus_busy(i2c_bus)) {
151 i2c_end_transfer(i2c_bus);
152 }
153
154 if (i2c_start_send(i2c_bus, address)) {
155 ret = AUX_I2C_NACK;
156 break;
157 }
158
159 ret = AUX_I2C_ACK;
160 for (i = 0; i < len; i++) {
161 if (i2c_send(i2c_bus, data[i]) < 0) {
162 ret = AUX_I2C_NACK;
163 break;
164 }
165 }
166 i2c_end_transfer(i2c_bus);
167 break;
168 /*
169 * I2C MOT transactions.
170 *
171 * Here we send a start when:
172 * - We didn't start transaction yet.
173 * - We had a READ and we do a WRITE.
174 * - We changed the address.
175 */
176 case WRITE_I2C_MOT:
177 ret = AUX_I2C_NACK;
178 if (!i2c_bus_busy(i2c_bus)) {
179 /*
180 * No transactions started..
181 */
182 if (i2c_start_send(i2c_bus, address)) {
183 break;
184 }
185 } else if ((address != bus->last_i2c_address) ||
186 (bus->last_transaction != cmd)) {
187 /*
188 * Transaction started but we need to restart..
189 */
190 i2c_end_transfer(i2c_bus);
191 if (i2c_start_send(i2c_bus, address)) {
192 break;
193 }
194 }
195
196 bus->last_transaction = cmd;
197 bus->last_i2c_address = address;
198 ret = AUX_I2C_ACK;
199 for (i = 0; i < len; i++) {
200 if (i2c_send(i2c_bus, data[i]) < 0) {
201 i2c_end_transfer(i2c_bus);
202 ret = AUX_I2C_NACK;
203 break;
204 }
205 }
206 break;
207 case READ_I2C_MOT:
208 ret = AUX_I2C_NACK;
209 if (!i2c_bus_busy(i2c_bus)) {
210 /*
211 * No transactions started..
212 */
213 if (i2c_start_recv(i2c_bus, address)) {
214 break;
215 }
216 } else if ((address != bus->last_i2c_address) ||
217 (bus->last_transaction != cmd)) {
218 /*
219 * Transaction started but we need to restart..
220 */
221 i2c_end_transfer(i2c_bus);
222 if (i2c_start_recv(i2c_bus, address)) {
223 break;
224 }
225 }
226
227 bus->last_transaction = cmd;
228 bus->last_i2c_address = address;
229 for (i = 0; i < len; i++) {
230 data[i] = i2c_recv(i2c_bus);
231 }
232 ret = AUX_I2C_ACK;
233 break;
234 default:
235 qemu_log_mask(LOG_UNIMP, "AUX cmd=%u not implemented\n", cmd);
236 return AUX_NACK;
237 }
238
239 DPRINTF("reply: %u\n", ret);
240 return ret;
241 }
242
243 static const TypeInfo aux_bus_info = {
244 .name = TYPE_AUX_BUS,
245 .parent = TYPE_BUS,
246 .instance_size = sizeof(AUXBus),
247 .class_init = aux_bus_class_init
248 };
249
250 /* aux-i2c implementation (internal not public) */
251 struct AUXTOI2CState {
252 /*< private >*/
253 DeviceState parent_obj;
254
255 /*< public >*/
256 I2CBus *i2c_bus;
257 };
258
259 static void aux_bridge_class_init(ObjectClass *oc, const void *data)
260 {
261 DeviceClass *dc = DEVICE_CLASS(oc);
262
263 /* This device is private and is created only once for each
264 * aux-bus in aux_bus_init(..). So don't allow the user to add one.
265 */
266 dc->user_creatable = false;
267 }
268
269 static void aux_bridge_init(Object *obj)
270 {
271 AUXTOI2CState *s = AUXTOI2C(obj);
272
273 s->i2c_bus = i2c_init_bus(DEVICE(obj), "aux-i2c");
274 }
275
276 static inline I2CBus *aux_bridge_get_i2c_bus(AUXTOI2CState *bridge)
277 {
278 return bridge->i2c_bus;
279 }
280
281 static const TypeInfo aux_to_i2c_type_info = {
282 .name = TYPE_AUXTOI2C,
283 .parent = TYPE_AUX_SLAVE,
284 .class_init = aux_bridge_class_init,
285 .instance_size = sizeof(AUXTOI2CState),
286 .instance_init = aux_bridge_init
287 };
288
289 /* aux-slave implementation */
290 #ifdef CONFIG_HMP
291 static bool aux_bus_is_bridge(AUXBus *bus, DeviceState *dev)
292 {
293 return (dev == DEVICE(bus->bridge));
294 }
295
296 static void aux_slave_dev_print(MonitorHMP *hmp, DeviceState *dev, int indent)
297 {
298 AUXBus *bus = AUX_BUS(qdev_get_parent_bus(dev));
299 AUXSlave *s;
300
301 /* Don't print anything if the device is I2C "bridge". */
302 if (aux_bus_is_bridge(bus, dev)) {
303 return;
304 }
305
306 s = AUX_SLAVE(dev);
307
308 monitor_hmp_printf(hmp, "%*smemory " HWADDR_FMT_plx "/" HWADDR_FMT_plx "\n",
309 indent, "",
310 object_property_get_uint(OBJECT(s->mmio), "addr", NULL),
311 memory_region_size(s->mmio));
312 }
313 #endif
314
315 void aux_init_mmio(AUXSlave *aux_slave, MemoryRegion *mmio)
316 {
317 assert(!aux_slave->mmio);
318 aux_slave->mmio = mmio;
319 }
320
321 static void aux_slave_class_init(ObjectClass *klass, const void *data)
322 {
323 DeviceClass *k = DEVICE_CLASS(klass);
324
325 set_bit(DEVICE_CATEGORY_MISC, k->categories);
326 k->bus_type = TYPE_AUX_BUS;
327 }
328
329 static const TypeInfo aux_slave_type_info = {
330 .name = TYPE_AUX_SLAVE,
331 .parent = TYPE_DEVICE,
332 .instance_size = sizeof(AUXSlave),
333 .abstract = true,
334 .class_init = aux_slave_class_init,
335 };
336
337 static void aux_register_types(void)
338 {
339 type_register_static(&aux_bus_info);
340 type_register_static(&aux_slave_type_info);
341 type_register_static(&aux_to_i2c_type_info);
342 }
343
344 type_init(aux_register_types)