hw/milkymist-minimac2.c

   1 /*
   2  *  QEMU model of the Milkymist minimac2 block.
   3  *
   4  *  Copyright (c) 2011 Michael Walle <michael@walle.cc>
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  *
  19  *
  20  * Specification available at:
  21  *   not available yet
  22  *
  23  */
  24
  25 #include "hw.h"
  26 #include "sysbus.h"
  27 #include "trace.h"
  28 #include "net.h"
  29 #include "qemu-error.h"
  30 #include "qdev-addr.h"
  31
  32 #include <zlib.h>
  33
  34 enum {
  35     R_SETUP = 0,
  36     R_MDIO,
  37     R_STATE0,
  38     R_COUNT0,
  39     R_STATE1,
  40     R_COUNT1,
  41     R_TXCOUNT,
  42     R_MAX
  43 };
  44
  45 enum {
  46     SETUP_PHY_RST = (1<<0),
  47 };
  48
  49 enum {
  50     MDIO_DO  = (1<<0),
  51     MDIO_DI  = (1<<1),
  52     MDIO_OE  = (1<<2),
  53     MDIO_CLK = (1<<3),
  54 };
  55
  56 enum {
  57     STATE_EMPTY   = 0,
  58     STATE_LOADED  = 1,
  59     STATE_PENDING = 2,
  60 };
  61
  62 enum {
  63     MDIO_OP_WRITE = 1,
  64     MDIO_OP_READ  = 2,
  65 };
  66
  67 enum mdio_state {
  68     MDIO_STATE_IDLE,
  69     MDIO_STATE_READING,
  70     MDIO_STATE_WRITING,
  71 };
  72
  73 enum {
  74     R_PHY_ID1  = 2,
  75     R_PHY_ID2  = 3,
  76     R_PHY_MAX  = 32
  77 };
  78
  79 #define MINIMAC2_MTU 1530
  80 #define MINIMAC2_BUFFER_SIZE 2048
  81
  82 struct MilkymistMinimac2MdioState {
  83     int last_clk;
  84     int count;
  85     uint32_t data;
  86     uint16_t data_out;
  87     int state;
  88
  89     uint8_t phy_addr;
  90     uint8_t reg_addr;
  91 };
  92 typedef struct MilkymistMinimac2MdioState MilkymistMinimac2MdioState;
  93
  94 struct MilkymistMinimac2State {
  95     SysBusDevice busdev;
  96     NICState *nic;
  97     NICConf conf;
  98     char *phy_model;
  99     target_phys_addr_t buffers_base;
 100     MemoryRegion buffers;
 101     MemoryRegion regs_region;
 102
 103     qemu_irq rx_irq;
 104     qemu_irq tx_irq;
 105
 106     uint32_t regs[R_MAX];
 107
 108     MilkymistMinimac2MdioState mdio;
 109
 110     uint16_t phy_regs[R_PHY_MAX];
 111
 112     uint8_t *rx0_buf;
 113     uint8_t *rx1_buf;
 114     uint8_t *tx_buf;
 115 };
 116 typedef struct MilkymistMinimac2State MilkymistMinimac2State;
 117
 118 static const uint8_t preamble_sfd[] = {
 119         0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0xd5
 120 };
 121
 122 static void minimac2_mdio_write_reg(MilkymistMinimac2State *s,
 123         uint8_t phy_addr, uint8_t reg_addr, uint16_t value)
 124 {
 125     trace_milkymist_minimac2_mdio_write(phy_addr, reg_addr, value);
 126
 127     /* nop */
 128 }
 129
 130 static uint16_t minimac2_mdio_read_reg(MilkymistMinimac2State *s,
 131         uint8_t phy_addr, uint8_t reg_addr)
 132 {
 133     uint16_t r = s->phy_regs[reg_addr];
 134
 135     trace_milkymist_minimac2_mdio_read(phy_addr, reg_addr, r);
 136
 137     return r;
 138 }
 139
 140 static void minimac2_update_mdio(MilkymistMinimac2State *s)
 141 {
 142     MilkymistMinimac2MdioState *m = &s->mdio;
 143
 144     /* detect rising clk edge */
 145     if (m->last_clk == 0 && (s->regs[R_MDIO] & MDIO_CLK)) {
 146         /* shift data in */
 147         int bit = ((s->regs[R_MDIO] & MDIO_DO)
 148                    && (s->regs[R_MDIO] & MDIO_OE)) ? 1 : 0;
 149         m->data = (m->data << 1) | bit;
 150
 151         /* check for sync */
 152         if (m->data == 0xffffffff) {
 153             m->count = 32;
 154         }
 155
 156         if (m->count == 16) {
 157             uint8_t start = (m->data >> 14) & 0x3;
 158             uint8_t op = (m->data >> 12) & 0x3;
 159             uint8_t ta = (m->data) & 0x3;
 160
 161             if (start == 1 && op == MDIO_OP_WRITE && ta == 2) {
 162                 m->state = MDIO_STATE_WRITING;
 163             } else if (start == 1 && op == MDIO_OP_READ && (ta & 1) == 0) {
 164                 m->state = MDIO_STATE_READING;
 165             } else {
 166                 m->state = MDIO_STATE_IDLE;
 167             }
 168
 169             if (m->state != MDIO_STATE_IDLE) {
 170                 m->phy_addr = (m->data >> 7) & 0x1f;
 171                 m->reg_addr = (m->data >> 2) & 0x1f;
 172             }
 173
 174             if (m->state == MDIO_STATE_READING) {
 175                 m->data_out = minimac2_mdio_read_reg(s, m->phy_addr,
 176                         m->reg_addr);
 177             }
 178         }
 179
 180         if (m->count < 16 && m->state == MDIO_STATE_READING) {
 181             int bit = (m->data_out & 0x8000) ? 1 : 0;
 182             m->data_out <<= 1;
 183
 184             if (bit) {
 185                 s->regs[R_MDIO] |= MDIO_DI;
 186             } else {
 187                 s->regs[R_MDIO] &= ~MDIO_DI;
 188             }
 189         }
 190
 191         if (m->count == 0 && m->state) {
 192             if (m->state == MDIO_STATE_WRITING) {
 193                 uint16_t data = m->data & 0xffff;
 194                 minimac2_mdio_write_reg(s, m->phy_addr, m->reg_addr, data);
 195             }
 196             m->state = MDIO_STATE_IDLE;
 197         }
 198         m->count--;
 199     }
 200
 201     m->last_clk = (s->regs[R_MDIO] & MDIO_CLK) ? 1 : 0;
 202 }
 203
 204 static size_t assemble_frame(uint8_t *buf, size_t size,
 205         const uint8_t *payload, size_t payload_size)
 206 {
 207     uint32_t crc;
 208
 209     if (size < payload_size + 12) {
 210         error_report("milkymist_minimac2: received too big ethernet frame");
 211         return 0;
 212     }
 213
 214     /* prepend preamble and sfd */
 215     memcpy(buf, preamble_sfd, 8);
 216
 217     /* now copy the payload */
 218     memcpy(buf + 8, payload, payload_size);
 219
 220     /* pad frame if needed */
 221     if (payload_size < 60) {
 222         memset(buf + payload_size + 8, 0, 60 - payload_size);
 223         payload_size = 60;
 224     }
 225
 226     /* append fcs */
 227     crc = cpu_to_le32(crc32(0, buf + 8, payload_size));
 228     memcpy(buf + payload_size + 8, &crc, 4);
 229
 230     return payload_size + 12;
 231 }
 232
 233 static void minimac2_tx(MilkymistMinimac2State *s)
 234 {
 235     uint32_t txcount = s->regs[R_TXCOUNT];
 236     uint8_t *buf = s->tx_buf;
 237
 238     if (txcount < 64) {
 239         error_report("milkymist_minimac2: ethernet frame too small (%u < %u)",
 240                 txcount, 64);
 241         goto err;
 242     }
 243
 244     if (txcount > MINIMAC2_MTU) {
 245         error_report("milkymist_minimac2: MTU exceeded (%u > %u)",
 246                 txcount, MINIMAC2_MTU);
 247         goto err;
 248     }
 249
 250     if (memcmp(buf, preamble_sfd, 8) != 0) {
 251         error_report("milkymist_minimac2: frame doesn't contain the preamble "
 252                 "and/or the SFD (%02x %02x %02x %02x %02x %02x %02x %02x)",
 253                 buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
 254         goto err;
 255     }
 256
 257     trace_milkymist_minimac2_tx_frame(txcount - 12);
 258
 259     /* send packet, skipping preamble and sfd */
 260     qemu_send_packet_raw(&s->nic->nc, buf + 8, txcount - 12);
 261
 262     s->regs[R_TXCOUNT] = 0;
 263
 264 err:
 265     trace_milkymist_minimac2_pulse_irq_tx();
 266     qemu_irq_pulse(s->tx_irq);
 267 }
 268
 269 static void update_rx_interrupt(MilkymistMinimac2State *s)
 270 {
 271     if (s->regs[R_STATE0] == STATE_PENDING
 272             || s->regs[R_STATE1] == STATE_PENDING) {
 273         trace_milkymist_minimac2_raise_irq_rx();
 274         qemu_irq_raise(s->rx_irq);
 275     } else {
 276         trace_milkymist_minimac2_lower_irq_rx();
 277         qemu_irq_lower(s->rx_irq);
 278     }
 279 }
 280
 281 static ssize_t minimac2_rx(VLANClientState *nc, const uint8_t *buf, size_t size)
 282 {
 283     MilkymistMinimac2State *s = DO_UPCAST(NICState, nc, nc)->opaque;
 284
 285     uint32_t r_count;
 286     uint32_t r_state;
 287     uint8_t *rx_buf;
 288
 289     size_t frame_size;
 290
 291     trace_milkymist_minimac2_rx_frame(buf, size);
 292
 293     /* choose appropriate slot */
 294     if (s->regs[R_STATE0] == STATE_LOADED) {
 295         r_count = R_COUNT0;
 296         r_state = R_STATE0;
 297         rx_buf = s->rx0_buf;
 298     } else if (s->regs[R_STATE1] == STATE_LOADED) {
 299         r_count = R_COUNT1;
 300         r_state = R_STATE1;
 301         rx_buf = s->rx1_buf;
 302     } else {
 303         trace_milkymist_minimac2_drop_rx_frame(buf);
 304         return size;
 305     }
 306
 307     /* assemble frame */
 308     frame_size = assemble_frame(rx_buf, MINIMAC2_BUFFER_SIZE, buf, size);
 309
 310     if (frame_size == 0) {
 311         return size;
 312     }
 313
 314     trace_milkymist_minimac2_rx_transfer(rx_buf, frame_size);
 315
 316     /* update slot */
 317     s->regs[r_count] = frame_size;
 318     s->regs[r_state] = STATE_PENDING;
 319
 320     update_rx_interrupt(s);
 321
 322     return size;
 323 }
 324
 325 static uint64_t
 326 minimac2_read(void *opaque, target_phys_addr_t addr, unsigned size)
 327 {
 328     MilkymistMinimac2State *s = opaque;
 329     uint32_t r = 0;
 330
 331     addr >>= 2;
 332     switch (addr) {
 333     case R_SETUP:
 334     case R_MDIO:
 335     case R_STATE0:
 336     case R_COUNT0:
 337     case R_STATE1:
 338     case R_COUNT1:
 339     case R_TXCOUNT:
 340         r = s->regs[addr];
 341         break;
 342
 343     default:
 344         error_report("milkymist_minimac2: read access to unknown register 0x"
 345                 TARGET_FMT_plx, addr << 2);
 346         break;
 347     }
 348
 349     trace_milkymist_minimac2_memory_read(addr << 2, r);
 350
 351     return r;
 352 }
 353
 354 static void
 355 minimac2_write(void *opaque, target_phys_addr_t addr, uint64_t value,
 356                unsigned size)
 357 {
 358     MilkymistMinimac2State *s = opaque;
 359
 360     trace_milkymist_minimac2_memory_read(addr, value);
 361
 362     addr >>= 2;
 363     switch (addr) {
 364     case R_MDIO:
 365     {
 366         /* MDIO_DI is read only */
 367         int mdio_di = (s->regs[R_MDIO] & MDIO_DI);
 368         s->regs[R_MDIO] = value;
 369         if (mdio_di) {
 370             s->regs[R_MDIO] |= mdio_di;
 371         } else {
 372             s->regs[R_MDIO] &= ~mdio_di;
 373         }
 374
 375         minimac2_update_mdio(s);
 376     } break;
 377     case R_TXCOUNT:
 378         s->regs[addr] = value;
 379         if (value > 0) {
 380             minimac2_tx(s);
 381         }
 382         break;
 383     case R_STATE0:
 384     case R_STATE1:
 385         s->regs[addr] = value;
 386         update_rx_interrupt(s);
 387         break;
 388     case R_SETUP:
 389     case R_COUNT0:
 390     case R_COUNT1:
 391         s->regs[addr] = value;
 392         break;
 393
 394     default:
 395         error_report("milkymist_minimac2: write access to unknown register 0x"
 396                 TARGET_FMT_plx, addr << 2);
 397         break;
 398     }
 399 }
 400
 401 static const MemoryRegionOps minimac2_ops = {
 402     .read = minimac2_read,
 403     .write = minimac2_write,
 404     .valid = {
 405         .min_access_size = 4,
 406         .max_access_size = 4,
 407     },
 408     .endianness = DEVICE_NATIVE_ENDIAN,
 409 };
 410
 411 static int minimac2_can_rx(VLANClientState *nc)
 412 {
 413     MilkymistMinimac2State *s = DO_UPCAST(NICState, nc, nc)->opaque;
 414
 415     if (s->regs[R_STATE0] == STATE_LOADED) {
 416         return 1;
 417     }
 418     if (s->regs[R_STATE1] == STATE_LOADED) {
 419         return 1;
 420     }
 421
 422     return 0;
 423 }
 424
 425 static void minimac2_cleanup(VLANClientState *nc)
 426 {
 427     MilkymistMinimac2State *s = DO_UPCAST(NICState, nc, nc)->opaque;
 428
 429     s->nic = NULL;
 430 }
 431
 432 static void milkymist_minimac2_reset(DeviceState *d)
 433 {
 434     MilkymistMinimac2State *s =
 435             container_of(d, MilkymistMinimac2State, busdev.qdev);
 436     int i;
 437
 438     for (i = 0; i < R_MAX; i++) {
 439         s->regs[i] = 0;
 440     }
 441     for (i = 0; i < R_PHY_MAX; i++) {
 442         s->phy_regs[i] = 0;
 443     }
 444
 445     /* defaults */
 446     s->phy_regs[R_PHY_ID1] = 0x0022; /* Micrel KSZ8001L */
 447     s->phy_regs[R_PHY_ID2] = 0x161a;
 448 }
 449
 450 static NetClientInfo net_milkymist_minimac2_info = {
 451     .type = NET_CLIENT_TYPE_NIC,
 452     .size = sizeof(NICState),
 453     .can_receive = minimac2_can_rx,
 454     .receive = minimac2_rx,
 455     .cleanup = minimac2_cleanup,
 456 };
 457
 458 static int milkymist_minimac2_init(SysBusDevice *dev)
 459 {
 460     MilkymistMinimac2State *s = FROM_SYSBUS(typeof(*s), dev);
 461     size_t buffers_size = TARGET_PAGE_ALIGN(3 * MINIMAC2_BUFFER_SIZE);
 462
 463     sysbus_init_irq(dev, &s->rx_irq);
 464     sysbus_init_irq(dev, &s->tx_irq);
 465
 466     memory_region_init_io(&s->regs_region, &minimac2_ops, s,
 467                           "milkymist-minimac2", R_MAX * 4);
 468     sysbus_init_mmio_region(dev, &s->regs_region);
 469
 470     /* register buffers memory */
 471     memory_region_init_ram(&s->buffers, NULL, "milkymist-minimac2.buffers",
 472                            buffers_size);
 473     s->rx0_buf = memory_region_get_ram_ptr(&s->buffers);
 474     s->rx1_buf = s->rx0_buf + MINIMAC2_BUFFER_SIZE;
 475     s->tx_buf = s->rx1_buf + MINIMAC2_BUFFER_SIZE;
 476
 477     sysbus_add_memory(dev, s->buffers_base, &s->buffers);
 478
 479     qemu_macaddr_default_if_unset(&s->conf.macaddr);
 480     s->nic = qemu_new_nic(&net_milkymist_minimac2_info, &s->conf,
 481                           dev->qdev.info->name, dev->qdev.id, s);
 482     qemu_format_nic_info_str(&s->nic->nc, s->conf.macaddr.a);
 483
 484     return 0;
 485 }
 486
 487 static const VMStateDescription vmstate_milkymist_minimac2_mdio = {
 488     .name = "milkymist-minimac2-mdio",
 489     .version_id = 1,
 490     .minimum_version_id = 1,
 491     .minimum_version_id_old = 1,
 492     .fields      = (VMStateField[]) {
 493         VMSTATE_INT32(last_clk, MilkymistMinimac2MdioState),
 494         VMSTATE_INT32(count, MilkymistMinimac2MdioState),
 495         VMSTATE_UINT32(data, MilkymistMinimac2MdioState),
 496         VMSTATE_UINT16(data_out, MilkymistMinimac2MdioState),
 497         VMSTATE_INT32(state, MilkymistMinimac2MdioState),
 498         VMSTATE_UINT8(phy_addr, MilkymistMinimac2MdioState),
 499         VMSTATE_UINT8(reg_addr, MilkymistMinimac2MdioState),
 500         VMSTATE_END_OF_LIST()
 501     }
 502 };
 503
 504 static const VMStateDescription vmstate_milkymist_minimac2 = {
 505     .name = "milkymist-minimac2",
 506     .version_id = 1,
 507     .minimum_version_id = 1,
 508     .minimum_version_id_old = 1,
 509     .fields      = (VMStateField[]) {
 510         VMSTATE_UINT32_ARRAY(regs, MilkymistMinimac2State, R_MAX),
 511         VMSTATE_UINT16_ARRAY(phy_regs, MilkymistMinimac2State, R_PHY_MAX),
 512         VMSTATE_STRUCT(mdio, MilkymistMinimac2State, 0,
 513                 vmstate_milkymist_minimac2_mdio, MilkymistMinimac2MdioState),
 514         VMSTATE_END_OF_LIST()
 515     }
 516 };
 517
 518 static SysBusDeviceInfo milkymist_minimac2_info = {
 519     .init = milkymist_minimac2_init,
 520     .qdev.name  = "milkymist-minimac2",
 521     .qdev.size  = sizeof(MilkymistMinimac2State),
 522     .qdev.vmsd  = &vmstate_milkymist_minimac2,
 523     .qdev.reset = milkymist_minimac2_reset,
 524     .qdev.props = (Property[]) {
 525         DEFINE_PROP_TADDR("buffers_base", MilkymistMinimac2State,
 526                 buffers_base, 0),
 527         DEFINE_NIC_PROPERTIES(MilkymistMinimac2State, conf),
 528         DEFINE_PROP_STRING("phy_model", MilkymistMinimac2State, phy_model),
 529         DEFINE_PROP_END_OF_LIST(),
 530     }
 531 };
 532
 533 static void milkymist_minimac2_register(void)
 534 {
 535     sysbus_register_withprop(&milkymist_minimac2_info);
 536 }
 537
 538 device_init(milkymist_minimac2_register)