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
 101     qemu_irq rx_irq;
 102     qemu_irq tx_irq;
 103
 104     uint32_t regs[R_MAX];
 105
 106     MilkymistMinimac2MdioState mdio;
 107
 108     uint16_t phy_regs[R_PHY_MAX];
 109
 110     uint8_t *rx0_buf;
 111     uint8_t *rx1_buf;
 112     uint8_t *tx_buf;
 113 };
 114 typedef struct MilkymistMinimac2State MilkymistMinimac2State;
 115
 116 static const uint8_t preamble_sfd[] = {
 117         0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0xd5
 118 };
 119
 120 static void minimac2_mdio_write_reg(MilkymistMinimac2State *s,
 121         uint8_t phy_addr, uint8_t reg_addr, uint16_t value)
 122 {
 123     trace_milkymist_minimac2_mdio_write(phy_addr, reg_addr, value);
 124
 125     /* nop */
 126 }
 127
 128 static uint16_t minimac2_mdio_read_reg(MilkymistMinimac2State *s,
 129         uint8_t phy_addr, uint8_t reg_addr)
 130 {
 131     uint16_t r = s->phy_regs[reg_addr];
 132
 133     trace_milkymist_minimac2_mdio_read(phy_addr, reg_addr, r);
 134
 135     return r;
 136 }
 137
 138 static void minimac2_update_mdio(MilkymistMinimac2State *s)
 139 {
 140     MilkymistMinimac2MdioState *m = &s->mdio;
 141
 142     /* detect rising clk edge */
 143     if (m->last_clk == 0 && (s->regs[R_MDIO] & MDIO_CLK)) {
 144         /* shift data in */
 145         int bit = ((s->regs[R_MDIO] & MDIO_DO)
 146                    && (s->regs[R_MDIO] & MDIO_OE)) ? 1 : 0;
 147         m->data = (m->data << 1) | bit;
 148
 149         /* check for sync */
 150         if (m->data == 0xffffffff) {
 151             m->count = 32;
 152         }
 153
 154         if (m->count == 16) {
 155             uint8_t start = (m->data >> 14) & 0x3;
 156             uint8_t op = (m->data >> 12) & 0x3;
 157             uint8_t ta = (m->data) & 0x3;
 158
 159             if (start == 1 && op == MDIO_OP_WRITE && ta == 2) {
 160                 m->state = MDIO_STATE_WRITING;
 161             } else if (start == 1 && op == MDIO_OP_READ && (ta & 1) == 0) {
 162                 m->state = MDIO_STATE_READING;
 163             } else {
 164                 m->state = MDIO_STATE_IDLE;
 165             }
 166
 167             if (m->state != MDIO_STATE_IDLE) {
 168                 m->phy_addr = (m->data >> 7) & 0x1f;
 169                 m->reg_addr = (m->data >> 2) & 0x1f;
 170             }
 171
 172             if (m->state == MDIO_STATE_READING) {
 173                 m->data_out = minimac2_mdio_read_reg(s, m->phy_addr,
 174                         m->reg_addr);
 175             }
 176         }
 177
 178         if (m->count < 16 && m->state == MDIO_STATE_READING) {
 179             int bit = (m->data_out & 0x8000) ? 1 : 0;
 180             m->data_out <<= 1;
 181
 182             if (bit) {
 183                 s->regs[R_MDIO] |= MDIO_DI;
 184             } else {
 185                 s->regs[R_MDIO] &= ~MDIO_DI;
 186             }
 187         }
 188
 189         if (m->count == 0 && m->state) {
 190             if (m->state == MDIO_STATE_WRITING) {
 191                 uint16_t data = m->data & 0xffff;
 192                 minimac2_mdio_write_reg(s, m->phy_addr, m->reg_addr, data);
 193             }
 194             m->state = MDIO_STATE_IDLE;
 195         }
 196         m->count--;
 197     }
 198
 199     m->last_clk = (s->regs[R_MDIO] & MDIO_CLK) ? 1 : 0;
 200 }
 201
 202 static size_t assemble_frame(uint8_t *buf, size_t size,
 203         const uint8_t *payload, size_t payload_size)
 204 {
 205     uint32_t crc;
 206
 207     if (size < payload_size + 12) {
 208         error_report("milkymist_minimac2: received too big ethernet frame");
 209         return 0;
 210     }
 211
 212     /* prepend preamble and sfd */
 213     memcpy(buf, preamble_sfd, 8);
 214
 215     /* now copy the payload */
 216     memcpy(buf + 8, payload, payload_size);
 217
 218     /* pad frame if needed */
 219     if (payload_size < 60) {
 220         memset(buf + payload_size + 8, 0, 60 - payload_size);
 221         payload_size = 60;
 222     }
 223
 224     /* append fcs */
 225     crc = cpu_to_le32(crc32(0, buf + 8, payload_size));
 226     memcpy(buf + payload_size + 8, &crc, 4);
 227
 228     return payload_size + 12;
 229 }
 230
 231 static void minimac2_tx(MilkymistMinimac2State *s)
 232 {
 233     uint32_t txcount = s->regs[R_TXCOUNT];
 234     uint8_t *buf = s->tx_buf;
 235
 236     if (txcount < 64) {
 237         error_report("milkymist_minimac2: ethernet frame too small (%u < %u)",
 238                 txcount, 64);
 239         goto err;
 240     }
 241
 242     if (txcount > MINIMAC2_MTU) {
 243         error_report("milkymist_minimac2: MTU exceeded (%u > %u)",
 244                 txcount, MINIMAC2_MTU);
 245         goto err;
 246     }
 247
 248     if (memcmp(buf, preamble_sfd, 8) != 0) {
 249         error_report("milkymist_minimac2: frame doesn't contain the preamble "
 250                 "and/or the SFD (%02x %02x %02x %02x %02x %02x %02x %02x)",
 251                 buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
 252         goto err;
 253     }
 254
 255     trace_milkymist_minimac2_tx_frame(txcount - 12);
 256
 257     /* send packet, skipping preamble and sfd */
 258     qemu_send_packet_raw(&s->nic->nc, buf + 8, txcount - 12);
 259
 260     s->regs[R_TXCOUNT] = 0;
 261
 262 err:
 263     trace_milkymist_minimac2_pulse_irq_tx();
 264     qemu_irq_pulse(s->tx_irq);
 265 }
 266
 267 static void update_rx_interrupt(MilkymistMinimac2State *s)
 268 {
 269     if (s->regs[R_STATE0] == STATE_PENDING
 270             || s->regs[R_STATE1] == STATE_PENDING) {
 271         trace_milkymist_minimac2_raise_irq_rx();
 272         qemu_irq_raise(s->rx_irq);
 273     } else {
 274         trace_milkymist_minimac2_lower_irq_rx();
 275         qemu_irq_lower(s->rx_irq);
 276     }
 277 }
 278
 279 static ssize_t minimac2_rx(VLANClientState *nc, const uint8_t *buf, size_t size)
 280 {
 281     MilkymistMinimac2State *s = DO_UPCAST(NICState, nc, nc)->opaque;
 282
 283     uint32_t r_count;
 284     uint32_t r_state;
 285     uint8_t *rx_buf;
 286
 287     size_t frame_size;
 288
 289     trace_milkymist_minimac2_rx_frame(buf, size);
 290
 291     /* choose appropriate slot */
 292     if (s->regs[R_STATE0] == STATE_LOADED) {
 293         r_count = R_COUNT0;
 294         r_state = R_STATE0;
 295         rx_buf = s->rx0_buf;
 296     } else if (s->regs[R_STATE1] == STATE_LOADED) {
 297         r_count = R_COUNT1;
 298         r_state = R_STATE1;
 299         rx_buf = s->rx1_buf;
 300     } else {
 301         trace_milkymist_minimac2_drop_rx_frame(buf);
 302         return size;
 303     }
 304
 305     /* assemble frame */
 306     frame_size = assemble_frame(rx_buf, MINIMAC2_BUFFER_SIZE, buf, size);
 307
 308     if (frame_size == 0) {
 309         return size;
 310     }
 311
 312     trace_milkymist_minimac2_rx_transfer(rx_buf, frame_size);
 313
 314     /* update slot */
 315     s->regs[r_count] = frame_size;
 316     s->regs[r_state] = STATE_PENDING;
 317
 318     update_rx_interrupt(s);
 319
 320     return size;
 321 }
 322
 323 static uint32_t
 324 minimac2_read(void *opaque, target_phys_addr_t addr)
 325 {
 326     MilkymistMinimac2State *s = opaque;
 327     uint32_t r = 0;
 328
 329     addr >>= 2;
 330     switch (addr) {
 331     case R_SETUP:
 332     case R_MDIO:
 333     case R_STATE0:
 334     case R_COUNT0:
 335     case R_STATE1:
 336     case R_COUNT1:
 337     case R_TXCOUNT:
 338         r = s->regs[addr];
 339         break;
 340
 341     default:
 342         error_report("milkymist_minimac2: read access to unknown register 0x"
 343                 TARGET_FMT_plx, addr << 2);
 344         break;
 345     }
 346
 347     trace_milkymist_minimac2_memory_read(addr << 2, r);
 348
 349     return r;
 350 }
 351
 352 static void
 353 minimac2_write(void *opaque, target_phys_addr_t addr, uint32_t value)
 354 {
 355     MilkymistMinimac2State *s = opaque;
 356
 357     trace_milkymist_minimac2_memory_read(addr, value);
 358
 359     addr >>= 2;
 360     switch (addr) {
 361     case R_MDIO:
 362     {
 363         /* MDIO_DI is read only */
 364         int mdio_di = (s->regs[R_MDIO] & MDIO_DI);
 365         s->regs[R_MDIO] = value;
 366         if (mdio_di) {
 367             s->regs[R_MDIO] |= mdio_di;
 368         } else {
 369             s->regs[R_MDIO] &= ~mdio_di;
 370         }
 371
 372         minimac2_update_mdio(s);
 373     } break;
 374     case R_TXCOUNT:
 375         s->regs[addr] = value;
 376         if (value > 0) {
 377             minimac2_tx(s);
 378         }
 379         break;
 380     case R_STATE0:
 381     case R_STATE1:
 382         s->regs[addr] = value;
 383         update_rx_interrupt(s);
 384         break;
 385     case R_SETUP:
 386     case R_COUNT0:
 387     case R_COUNT1:
 388         s->regs[addr] = value;
 389         break;
 390
 391     default:
 392         error_report("milkymist_minimac2: write access to unknown register 0x"
 393                 TARGET_FMT_plx, addr << 2);
 394         break;
 395     }
 396 }
 397
 398 static CPUReadMemoryFunc * const minimac2_read_fn[] = {
 399     NULL,
 400     NULL,
 401     &minimac2_read,
 402 };
 403
 404 static CPUWriteMemoryFunc * const minimac2_write_fn[] = {
 405     NULL,
 406     NULL,
 407     &minimac2_write,
 408 };
 409
 410 static int minimac2_can_rx(VLANClientState *nc)
 411 {
 412     MilkymistMinimac2State *s = DO_UPCAST(NICState, nc, nc)->opaque;
 413
 414     if (s->regs[R_STATE0] == STATE_LOADED) {
 415         return 1;
 416     }
 417     if (s->regs[R_STATE1] == STATE_LOADED) {
 418         return 1;
 419     }
 420
 421     return 0;
 422 }
 423
 424 static void minimac2_cleanup(VLANClientState *nc)
 425 {
 426     MilkymistMinimac2State *s = DO_UPCAST(NICState, nc, nc)->opaque;
 427
 428     s->nic = NULL;
 429 }
 430
 431 static void milkymist_minimac2_reset(DeviceState *d)
 432 {
 433     MilkymistMinimac2State *s =
 434             container_of(d, MilkymistMinimac2State, busdev.qdev);
 435     int i;
 436
 437     for (i = 0; i < R_MAX; i++) {
 438         s->regs[i] = 0;
 439     }
 440     for (i = 0; i < R_PHY_MAX; i++) {
 441         s->phy_regs[i] = 0;
 442     }
 443
 444     /* defaults */
 445     s->phy_regs[R_PHY_ID1] = 0x0022; /* Micrel KSZ8001L */
 446     s->phy_regs[R_PHY_ID2] = 0x161a;
 447 }
 448
 449 static NetClientInfo net_milkymist_minimac2_info = {
 450     .type = NET_CLIENT_TYPE_NIC,
 451     .size = sizeof(NICState),
 452     .can_receive = minimac2_can_rx,
 453     .receive = minimac2_rx,
 454     .cleanup = minimac2_cleanup,
 455 };
 456
 457 static int milkymist_minimac2_init(SysBusDevice *dev)
 458 {
 459     MilkymistMinimac2State *s = FROM_SYSBUS(typeof(*s), dev);
 460     int regs;
 461     ram_addr_t buffers;
 462     size_t buffers_size = TARGET_PAGE_ALIGN(3 * MINIMAC2_BUFFER_SIZE);
 463
 464     sysbus_init_irq(dev, &s->rx_irq);
 465     sysbus_init_irq(dev, &s->tx_irq);
 466
 467     regs = cpu_register_io_memory(minimac2_read_fn, minimac2_write_fn, s,
 468             DEVICE_NATIVE_ENDIAN);
 469     sysbus_init_mmio(dev, R_MAX * 4, regs);
 470
 471     /* register buffers memory */
 472     buffers = qemu_ram_alloc(NULL, "milkymist_minimac2.buffers", buffers_size);
 473     s->rx0_buf = qemu_get_ram_ptr(buffers);
 474     s->rx1_buf = s->rx0_buf + MINIMAC2_BUFFER_SIZE;
 475     s->tx_buf = s->rx1_buf + MINIMAC2_BUFFER_SIZE;
 476
 477     cpu_register_physical_memory(s->buffers_base, buffers_size,
 478             buffers | IO_MEM_RAM);
 479
 480     qemu_macaddr_default_if_unset(&s->conf.macaddr);
 481     s->nic = qemu_new_nic(&net_milkymist_minimac2_info, &s->conf,
 482                           dev->qdev.info->name, dev->qdev.id, s);
 483     qemu_format_nic_info_str(&s->nic->nc, s->conf.macaddr.a);
 484
 485     return 0;
 486 }
 487
 488 static const VMStateDescription vmstate_milkymist_minimac2_mdio = {
 489     .name = "milkymist-minimac2-mdio",
 490     .version_id = 1,
 491     .minimum_version_id = 1,
 492     .minimum_version_id_old = 1,
 493     .fields      = (VMStateField[]) {
 494         VMSTATE_INT32(last_clk, MilkymistMinimac2MdioState),
 495         VMSTATE_INT32(count, MilkymistMinimac2MdioState),
 496         VMSTATE_UINT32(data, MilkymistMinimac2MdioState),
 497         VMSTATE_UINT16(data_out, MilkymistMinimac2MdioState),
 498         VMSTATE_INT32(state, MilkymistMinimac2MdioState),
 499         VMSTATE_UINT8(phy_addr, MilkymistMinimac2MdioState),
 500         VMSTATE_UINT8(reg_addr, MilkymistMinimac2MdioState),
 501         VMSTATE_END_OF_LIST()
 502     }
 503 };
 504
 505 static const VMStateDescription vmstate_milkymist_minimac2 = {
 506     .name = "milkymist-minimac2",
 507     .version_id = 1,
 508     .minimum_version_id = 1,
 509     .minimum_version_id_old = 1,
 510     .fields      = (VMStateField[]) {
 511         VMSTATE_UINT32_ARRAY(regs, MilkymistMinimac2State, R_MAX),
 512         VMSTATE_UINT16_ARRAY(phy_regs, MilkymistMinimac2State, R_PHY_MAX),
 513         VMSTATE_STRUCT(mdio, MilkymistMinimac2State, 0,
 514                 vmstate_milkymist_minimac2_mdio, MilkymistMinimac2MdioState),
 515         VMSTATE_END_OF_LIST()
 516     }
 517 };
 518
 519 static SysBusDeviceInfo milkymist_minimac2_info = {
 520     .init = milkymist_minimac2_init,
 521     .qdev.name  = "milkymist-minimac2",
 522     .qdev.size  = sizeof(MilkymistMinimac2State),
 523     .qdev.vmsd  = &vmstate_milkymist_minimac2,
 524     .qdev.reset = milkymist_minimac2_reset,
 525     .qdev.props = (Property[]) {
 526         DEFINE_PROP_TADDR("buffers_base", MilkymistMinimac2State,
 527                 buffers_base, 0),
 528         DEFINE_NIC_PROPERTIES(MilkymistMinimac2State, conf),
 529         DEFINE_PROP_STRING("phy_model", MilkymistMinimac2State, phy_model),
 530         DEFINE_PROP_END_OF_LIST(),
 531     }
 532 };
 533
 534 static void milkymist_minimac2_register(void)
 535 {
 536     sysbus_register_withprop(&milkymist_minimac2_info);
 537 }
 538
 539 device_init(milkymist_minimac2_register)