hw/misc/auxbus.c

   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 "qapi/error.h"
  37
  38 #ifndef DEBUG_AUX
  39 #define DEBUG_AUX 0
  40 #endif
  41
  42 #define DPRINTF(fmt, ...) do {                                                 \
  43     if (DEBUG_AUX) {                                                           \
  44         qemu_log("aux: " fmt , ## __VA_ARGS__);                                \
  45     }                                                                          \
  46 } while (0)
  47
  48
  49 static void aux_slave_dev_print(Monitor *mon, DeviceState *dev, int indent);
  50 static inline I2CBus *aux_bridge_get_i2c_bus(AUXTOI2CState *bridge);
  51
  52 /* aux-bus implementation (internal not public) */
  53 static void aux_bus_class_init(ObjectClass *klass, void *data)
  54 {
  55     BusClass *k = BUS_CLASS(klass);
  56
  57     /* AUXSlave has an MMIO so we need to change the way we print information
  58      * in monitor.
  59      */
  60     k->print_dev = aux_slave_dev_print;
  61 }
  62
  63 AUXBus *aux_bus_init(DeviceState *parent, const char *name)
  64 {
  65     AUXBus *bus;
  66     Object *auxtoi2c;
  67
  68     bus = AUX_BUS(qbus_new(TYPE_AUX_BUS, parent, name));
  69     auxtoi2c = object_new_with_props(TYPE_AUXTOI2C, OBJECT(bus), "i2c",
  70                                      &error_abort, NULL);
  71
  72     bus->bridge = AUXTOI2C(auxtoi2c);
  73
  74     /* Memory related. */
  75     bus->aux_io = g_malloc(sizeof(*bus->aux_io));
  76     memory_region_init(bus->aux_io, OBJECT(bus), "aux-io", 1 * MiB);
  77     address_space_init(&bus->aux_addr_space, bus->aux_io, "aux-io");
  78     return bus;
  79 }
  80
  81 void aux_bus_realize(AUXBus *bus)
  82 {
  83     qdev_realize(DEVICE(bus->bridge), BUS(bus), &error_fatal);
  84 }
  85
  86 void aux_map_slave(AUXSlave *aux_dev, hwaddr addr)
  87 {
  88     DeviceState *dev = DEVICE(aux_dev);
  89     AUXBus *bus = AUX_BUS(qdev_get_parent_bus(dev));
  90     memory_region_add_subregion(bus->aux_io, addr, aux_dev->mmio);
  91 }
  92
  93 static bool aux_bus_is_bridge(AUXBus *bus, DeviceState *dev)
  94 {
  95     return (dev == DEVICE(bus->bridge));
  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, 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 static void aux_slave_dev_print(Monitor *mon, DeviceState *dev, int indent)
 291 {
 292     AUXBus *bus = AUX_BUS(qdev_get_parent_bus(dev));
 293     AUXSlave *s;
 294
 295     /* Don't print anything if the device is I2C "bridge". */
 296     if (aux_bus_is_bridge(bus, dev)) {
 297         return;
 298     }
 299
 300     s = AUX_SLAVE(dev);
 301
 302     monitor_printf(mon, "%*smemory " TARGET_FMT_plx "/" TARGET_FMT_plx "\n",
 303                    indent, "",
 304                    object_property_get_uint(OBJECT(s->mmio), "addr", NULL),
 305                    memory_region_size(s->mmio));
 306 }
 307
 308 void aux_init_mmio(AUXSlave *aux_slave, MemoryRegion *mmio)
 309 {
 310     assert(!aux_slave->mmio);
 311     aux_slave->mmio = mmio;
 312 }
 313
 314 static void aux_slave_class_init(ObjectClass *klass, void *data)
 315 {
 316     DeviceClass *k = DEVICE_CLASS(klass);
 317
 318     set_bit(DEVICE_CATEGORY_MISC, k->categories);
 319     k->bus_type = TYPE_AUX_BUS;
 320 }
 321
 322 static const TypeInfo aux_slave_type_info = {
 323     .name = TYPE_AUX_SLAVE,
 324     .parent = TYPE_DEVICE,
 325     .instance_size = sizeof(AUXSlave),
 326     .abstract = true,
 327     .class_init = aux_slave_class_init,
 328 };
 329
 330 static void aux_register_types(void)
 331 {
 332     type_register_static(&aux_bus_info);
 333     type_register_static(&aux_slave_type_info);
 334     type_register_static(&aux_to_i2c_type_info);
 335 }
 336
 337 type_init(aux_register_types)