qemu/hw/char/ipoctal232.c
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   1/*
   2 * QEMU GE IP-Octal 232 IndustryPack emulation
   3 *
   4 * Copyright (C) 2012 Igalia, S.L.
   5 * Author: Alberto Garcia <berto@igalia.com>
   6 *
   7 * This code is licensed under the GNU GPL v2 or (at your option) any
   8 * later version.
   9 */
  10
  11#include "qemu/osdep.h"
  12#include "hw/ipack/ipack.h"
  13#include "hw/irq.h"
  14#include "hw/qdev-properties.h"
  15#include "migration/vmstate.h"
  16#include "qemu/bitops.h"
  17#include "qemu/module.h"
  18#include "chardev/char-fe.h"
  19
  20/* #define DEBUG_IPOCTAL */
  21
  22#ifdef DEBUG_IPOCTAL
  23#define DPRINTF2(fmt, ...) \
  24    do { fprintf(stderr, fmt, ## __VA_ARGS__); } while (0)
  25#else
  26#define DPRINTF2(fmt, ...) do { } while (0)
  27#endif
  28
  29#define DPRINTF(fmt, ...) DPRINTF2("IP-Octal: " fmt, ## __VA_ARGS__)
  30
  31#define RX_FIFO_SIZE 3
  32
  33/* The IP-Octal has 8 channels (a-h)
  34   divided into 4 blocks (A-D) */
  35#define N_CHANNELS 8
  36#define N_BLOCKS   4
  37
  38#define REG_MRa  0x01
  39#define REG_MRb  0x11
  40#define REG_SRa  0x03
  41#define REG_SRb  0x13
  42#define REG_CSRa 0x03
  43#define REG_CSRb 0x13
  44#define REG_CRa  0x05
  45#define REG_CRb  0x15
  46#define REG_RHRa 0x07
  47#define REG_RHRb 0x17
  48#define REG_THRa 0x07
  49#define REG_THRb 0x17
  50#define REG_ACR  0x09
  51#define REG_ISR  0x0B
  52#define REG_IMR  0x0B
  53#define REG_OPCR 0x1B
  54
  55#define CR_ENABLE_RX    BIT(0)
  56#define CR_DISABLE_RX   BIT(1)
  57#define CR_ENABLE_TX    BIT(2)
  58#define CR_DISABLE_TX   BIT(3)
  59#define CR_CMD(cr)      ((cr) >> 4)
  60#define CR_NO_OP        0
  61#define CR_RESET_MR     1
  62#define CR_RESET_RX     2
  63#define CR_RESET_TX     3
  64#define CR_RESET_ERR    4
  65#define CR_RESET_BRKINT 5
  66#define CR_START_BRK    6
  67#define CR_STOP_BRK     7
  68#define CR_ASSERT_RTSN  8
  69#define CR_NEGATE_RTSN  9
  70#define CR_TIMEOUT_ON   10
  71#define CR_TIMEOUT_OFF  12
  72
  73#define SR_RXRDY   BIT(0)
  74#define SR_FFULL   BIT(1)
  75#define SR_TXRDY   BIT(2)
  76#define SR_TXEMT   BIT(3)
  77#define SR_OVERRUN BIT(4)
  78#define SR_PARITY  BIT(5)
  79#define SR_FRAMING BIT(6)
  80#define SR_BREAK   BIT(7)
  81
  82#define ISR_TXRDYA BIT(0)
  83#define ISR_RXRDYA BIT(1)
  84#define ISR_BREAKA BIT(2)
  85#define ISR_CNTRDY BIT(3)
  86#define ISR_TXRDYB BIT(4)
  87#define ISR_RXRDYB BIT(5)
  88#define ISR_BREAKB BIT(6)
  89#define ISR_MPICHG BIT(7)
  90#define ISR_TXRDY(CH) (((CH) & 1) ? BIT(4) : BIT(0))
  91#define ISR_RXRDY(CH) (((CH) & 1) ? BIT(5) : BIT(1))
  92#define ISR_BREAK(CH) (((CH) & 1) ? BIT(6) : BIT(2))
  93
  94typedef struct IPOctalState IPOctalState;
  95typedef struct SCC2698Channel SCC2698Channel;
  96typedef struct SCC2698Block SCC2698Block;
  97
  98struct SCC2698Channel {
  99    IPOctalState *ipoctal;
 100    CharBackend dev;
 101    bool rx_enabled;
 102    uint8_t mr[2];
 103    uint8_t mr_idx;
 104    uint8_t sr;
 105    uint8_t rhr[RX_FIFO_SIZE];
 106    uint8_t rhr_idx;
 107    uint8_t rx_pending;
 108};
 109
 110struct SCC2698Block {
 111    uint8_t imr;
 112    uint8_t isr;
 113};
 114
 115struct IPOctalState {
 116    IPackDevice parent_obj;
 117
 118    SCC2698Channel ch[N_CHANNELS];
 119    SCC2698Block blk[N_BLOCKS];
 120    uint8_t irq_vector;
 121};
 122
 123#define TYPE_IPOCTAL "ipoctal232"
 124
 125#define IPOCTAL(obj) \
 126    OBJECT_CHECK(IPOctalState, (obj), TYPE_IPOCTAL)
 127
 128static const VMStateDescription vmstate_scc2698_channel = {
 129    .name = "scc2698_channel",
 130    .version_id = 1,
 131    .minimum_version_id = 1,
 132    .fields = (VMStateField[]) {
 133        VMSTATE_BOOL(rx_enabled, SCC2698Channel),
 134        VMSTATE_UINT8_ARRAY(mr, SCC2698Channel, 2),
 135        VMSTATE_UINT8(mr_idx, SCC2698Channel),
 136        VMSTATE_UINT8(sr, SCC2698Channel),
 137        VMSTATE_UINT8_ARRAY(rhr, SCC2698Channel, RX_FIFO_SIZE),
 138        VMSTATE_UINT8(rhr_idx, SCC2698Channel),
 139        VMSTATE_UINT8(rx_pending, SCC2698Channel),
 140        VMSTATE_END_OF_LIST()
 141    }
 142};
 143
 144static const VMStateDescription vmstate_scc2698_block = {
 145    .name = "scc2698_block",
 146    .version_id = 1,
 147    .minimum_version_id = 1,
 148    .fields = (VMStateField[]) {
 149        VMSTATE_UINT8(imr, SCC2698Block),
 150        VMSTATE_UINT8(isr, SCC2698Block),
 151        VMSTATE_END_OF_LIST()
 152    }
 153};
 154
 155static const VMStateDescription vmstate_ipoctal = {
 156    .name = "ipoctal232",
 157    .version_id = 1,
 158    .minimum_version_id = 1,
 159    .fields = (VMStateField[]) {
 160        VMSTATE_IPACK_DEVICE(parent_obj, IPOctalState),
 161        VMSTATE_STRUCT_ARRAY(ch, IPOctalState, N_CHANNELS, 1,
 162                             vmstate_scc2698_channel, SCC2698Channel),
 163        VMSTATE_STRUCT_ARRAY(blk, IPOctalState, N_BLOCKS, 1,
 164                             vmstate_scc2698_block, SCC2698Block),
 165        VMSTATE_UINT8(irq_vector, IPOctalState),
 166        VMSTATE_END_OF_LIST()
 167    }
 168};
 169
 170/* data[10] is 0x0C, not 0x0B as the doc says */
 171static const uint8_t id_prom_data[] = {
 172    0x49, 0x50, 0x41, 0x43, 0xF0, 0x22,
 173    0xA1, 0x00, 0x00, 0x00, 0x0C, 0xCC
 174};
 175
 176static void update_irq(IPOctalState *dev, unsigned block)
 177{
 178    IPackDevice *idev = IPACK_DEVICE(dev);
 179    /* Blocks A and B interrupt on INT0#, C and D on INT1#.
 180       Thus, to get the status we have to check two blocks. */
 181    SCC2698Block *blk0 = &dev->blk[block];
 182    SCC2698Block *blk1 = &dev->blk[block^1];
 183    unsigned intno = block / 2;
 184
 185    if ((blk0->isr & blk0->imr) || (blk1->isr & blk1->imr)) {
 186        qemu_irq_raise(idev->irq[intno]);
 187    } else {
 188        qemu_irq_lower(idev->irq[intno]);
 189    }
 190}
 191
 192static void write_cr(IPOctalState *dev, unsigned channel, uint8_t val)
 193{
 194    SCC2698Channel *ch = &dev->ch[channel];
 195    SCC2698Block *blk = &dev->blk[channel / 2];
 196
 197    DPRINTF("Write CR%c %u: ", channel + 'a', val);
 198
 199    /* The lower 4 bits are used to enable and disable Tx and Rx */
 200    if (val & CR_ENABLE_RX) {
 201        DPRINTF2("Rx on, ");
 202        ch->rx_enabled = true;
 203    }
 204    if (val & CR_DISABLE_RX) {
 205        DPRINTF2("Rx off, ");
 206        ch->rx_enabled = false;
 207    }
 208    if (val & CR_ENABLE_TX) {
 209        DPRINTF2("Tx on, ");
 210        ch->sr |= SR_TXRDY | SR_TXEMT;
 211        blk->isr |= ISR_TXRDY(channel);
 212    }
 213    if (val & CR_DISABLE_TX) {
 214        DPRINTF2("Tx off, ");
 215        ch->sr &= ~(SR_TXRDY | SR_TXEMT);
 216        blk->isr &= ~ISR_TXRDY(channel);
 217    }
 218
 219    DPRINTF2("cmd: ");
 220
 221    /* The rest of the bits implement different commands */
 222    switch (CR_CMD(val)) {
 223    case CR_NO_OP:
 224        DPRINTF2("none");
 225        break;
 226    case CR_RESET_MR:
 227        DPRINTF2("reset MR");
 228        ch->mr_idx = 0;
 229        break;
 230    case CR_RESET_RX:
 231        DPRINTF2("reset Rx");
 232        ch->rx_enabled = false;
 233        ch->rx_pending = 0;
 234        ch->sr &= ~SR_RXRDY;
 235        blk->isr &= ~ISR_RXRDY(channel);
 236        break;
 237    case CR_RESET_TX:
 238        DPRINTF2("reset Tx");
 239        ch->sr &= ~(SR_TXRDY | SR_TXEMT);
 240        blk->isr &= ~ISR_TXRDY(channel);
 241        break;
 242    case CR_RESET_ERR:
 243        DPRINTF2("reset err");
 244        ch->sr &= ~(SR_OVERRUN | SR_PARITY | SR_FRAMING | SR_BREAK);
 245        break;
 246    case CR_RESET_BRKINT:
 247        DPRINTF2("reset brk ch int");
 248        blk->isr &= ~(ISR_BREAKA | ISR_BREAKB);
 249        break;
 250    default:
 251        DPRINTF2("unsupported 0x%x", CR_CMD(val));
 252    }
 253
 254    DPRINTF2("\n");
 255}
 256
 257static uint16_t io_read(IPackDevice *ip, uint8_t addr)
 258{
 259    IPOctalState *dev = IPOCTAL(ip);
 260    uint16_t ret = 0;
 261    /* addr[7:6]: block   (A-D)
 262       addr[7:5]: channel (a-h)
 263       addr[5:0]: register */
 264    unsigned block = addr >> 5;
 265    unsigned channel = addr >> 4;
 266    /* Big endian, accessed using 8-bit bytes at odd locations */
 267    unsigned offset = (addr & 0x1F) ^ 1;
 268    SCC2698Channel *ch = &dev->ch[channel];
 269    SCC2698Block *blk = &dev->blk[block];
 270    uint8_t old_isr = blk->isr;
 271
 272    switch (offset) {
 273
 274    case REG_MRa:
 275    case REG_MRb:
 276        ret = ch->mr[ch->mr_idx];
 277        DPRINTF("Read MR%u%c: 0x%x\n", ch->mr_idx + 1, channel + 'a', ret);
 278        ch->mr_idx = 1;
 279        break;
 280
 281    case REG_SRa:
 282    case REG_SRb:
 283        ret = ch->sr;
 284        DPRINTF("Read SR%c: 0x%x\n", channel + 'a', ret);
 285        break;
 286
 287    case REG_RHRa:
 288    case REG_RHRb:
 289        ret = ch->rhr[ch->rhr_idx];
 290        if (ch->rx_pending > 0) {
 291            ch->rx_pending--;
 292            if (ch->rx_pending == 0) {
 293                ch->sr &= ~SR_RXRDY;
 294                blk->isr &= ~ISR_RXRDY(channel);
 295                qemu_chr_fe_accept_input(&ch->dev);
 296            } else {
 297                ch->rhr_idx = (ch->rhr_idx + 1) % RX_FIFO_SIZE;
 298            }
 299            if (ch->sr & SR_BREAK) {
 300                ch->sr &= ~SR_BREAK;
 301                blk->isr |= ISR_BREAK(channel);
 302            }
 303        }
 304        DPRINTF("Read RHR%c (0x%x)\n", channel + 'a', ret);
 305        break;
 306
 307    case REG_ISR:
 308        ret = blk->isr;
 309        DPRINTF("Read ISR%c: 0x%x\n", block + 'A', ret);
 310        break;
 311
 312    default:
 313        DPRINTF("Read unknown/unsupported register 0x%02x\n", offset);
 314    }
 315
 316    if (old_isr != blk->isr) {
 317        update_irq(dev, block);
 318    }
 319
 320    return ret;
 321}
 322
 323static void io_write(IPackDevice *ip, uint8_t addr, uint16_t val)
 324{
 325    IPOctalState *dev = IPOCTAL(ip);
 326    unsigned reg = val & 0xFF;
 327    /* addr[7:6]: block   (A-D)
 328       addr[7:5]: channel (a-h)
 329       addr[5:0]: register */
 330    unsigned block = addr >> 5;
 331    unsigned channel = addr >> 4;
 332    /* Big endian, accessed using 8-bit bytes at odd locations */
 333    unsigned offset = (addr & 0x1F) ^ 1;
 334    SCC2698Channel *ch = &dev->ch[channel];
 335    SCC2698Block *blk = &dev->blk[block];
 336    uint8_t old_isr = blk->isr;
 337    uint8_t old_imr = blk->imr;
 338
 339    switch (offset) {
 340
 341    case REG_MRa:
 342    case REG_MRb:
 343        ch->mr[ch->mr_idx] = reg;
 344        DPRINTF("Write MR%u%c 0x%x\n", ch->mr_idx + 1, channel + 'a', reg);
 345        ch->mr_idx = 1;
 346        break;
 347
 348    /* Not implemented */
 349    case REG_CSRa:
 350    case REG_CSRb:
 351        DPRINTF("Write CSR%c: 0x%x\n", channel + 'a', reg);
 352        break;
 353
 354    case REG_CRa:
 355    case REG_CRb:
 356        write_cr(dev, channel, reg);
 357        break;
 358
 359    case REG_THRa:
 360    case REG_THRb:
 361        if (ch->sr & SR_TXRDY) {
 362            uint8_t thr = reg;
 363            DPRINTF("Write THR%c (0x%x)\n", channel + 'a', reg);
 364            /* XXX this blocks entire thread. Rewrite to use
 365             * qemu_chr_fe_write and background I/O callbacks */
 366            qemu_chr_fe_write_all(&ch->dev, &thr, 1);
 367        } else {
 368            DPRINTF("Write THR%c (0x%x), Tx disabled\n", channel + 'a', reg);
 369        }
 370        break;
 371
 372    /* Not implemented */
 373    case REG_ACR:
 374        DPRINTF("Write ACR%c 0x%x\n", block + 'A', val);
 375        break;
 376
 377    case REG_IMR:
 378        DPRINTF("Write IMR%c 0x%x\n", block + 'A', val);
 379        blk->imr = reg;
 380        break;
 381
 382    /* Not implemented */
 383    case REG_OPCR:
 384        DPRINTF("Write OPCR%c 0x%x\n", block + 'A', val);
 385        break;
 386
 387    default:
 388        DPRINTF("Write unknown/unsupported register 0x%02x %u\n", offset, val);
 389    }
 390
 391    if (old_isr != blk->isr || old_imr != blk->imr) {
 392        update_irq(dev, block);
 393    }
 394}
 395
 396static uint16_t id_read(IPackDevice *ip, uint8_t addr)
 397{
 398    uint16_t ret = 0;
 399    unsigned pos = addr / 2; /* The ID PROM data is stored every other byte */
 400
 401    if (pos < ARRAY_SIZE(id_prom_data)) {
 402        ret = id_prom_data[pos];
 403    } else {
 404        DPRINTF("Attempt to read unavailable PROM data at 0x%x\n",  addr);
 405    }
 406
 407    return ret;
 408}
 409
 410static void id_write(IPackDevice *ip, uint8_t addr, uint16_t val)
 411{
 412    IPOctalState *dev = IPOCTAL(ip);
 413    if (addr == 1) {
 414        DPRINTF("Write IRQ vector: %u\n", (unsigned) val);
 415        dev->irq_vector = val; /* Undocumented, but the hw works like that */
 416    } else {
 417        DPRINTF("Attempt to write 0x%x to 0x%x\n", val, addr);
 418    }
 419}
 420
 421static uint16_t int_read(IPackDevice *ip, uint8_t addr)
 422{
 423    IPOctalState *dev = IPOCTAL(ip);
 424    /* Read address 0 to ACK INT0# and address 2 to ACK INT1# */
 425    if (addr != 0 && addr != 2) {
 426        DPRINTF("Attempt to read from 0x%x\n", addr);
 427        return 0;
 428    } else {
 429        /* Update interrupts if necessary */
 430        update_irq(dev, addr);
 431        return dev->irq_vector;
 432    }
 433}
 434
 435static void int_write(IPackDevice *ip, uint8_t addr, uint16_t val)
 436{
 437    DPRINTF("Attempt to write 0x%x to 0x%x\n", val, addr);
 438}
 439
 440static uint16_t mem_read16(IPackDevice *ip, uint32_t addr)
 441{
 442    DPRINTF("Attempt to read from 0x%x\n", addr);
 443    return 0;
 444}
 445
 446static void mem_write16(IPackDevice *ip, uint32_t addr, uint16_t val)
 447{
 448    DPRINTF("Attempt to write 0x%x to 0x%x\n", val, addr);
 449}
 450
 451static uint8_t mem_read8(IPackDevice *ip, uint32_t addr)
 452{
 453    DPRINTF("Attempt to read from 0x%x\n", addr);
 454    return 0;
 455}
 456
 457static void mem_write8(IPackDevice *ip, uint32_t addr, uint8_t val)
 458{
 459    IPOctalState *dev = IPOCTAL(ip);
 460    if (addr == 1) {
 461        DPRINTF("Write IRQ vector: %u\n", (unsigned) val);
 462        dev->irq_vector = val;
 463    } else {
 464        DPRINTF("Attempt to write 0x%x to 0x%x\n", val, addr);
 465    }
 466}
 467
 468static int hostdev_can_receive(void *opaque)
 469{
 470    SCC2698Channel *ch = opaque;
 471    int available_bytes = RX_FIFO_SIZE - ch->rx_pending;
 472    return ch->rx_enabled ? available_bytes : 0;
 473}
 474
 475static void hostdev_receive(void *opaque, const uint8_t *buf, int size)
 476{
 477    SCC2698Channel *ch = opaque;
 478    IPOctalState *dev = ch->ipoctal;
 479    unsigned pos = ch->rhr_idx + ch->rx_pending;
 480    int i;
 481
 482    assert(size + ch->rx_pending <= RX_FIFO_SIZE);
 483
 484    /* Copy data to the RxFIFO */
 485    for (i = 0; i < size; i++) {
 486        pos %= RX_FIFO_SIZE;
 487        ch->rhr[pos++] = buf[i];
 488    }
 489
 490    ch->rx_pending += size;
 491
 492    /* If the RxFIFO was empty raise an interrupt */
 493    if (!(ch->sr & SR_RXRDY)) {
 494        unsigned block, channel = 0;
 495        /* Find channel number to update the ISR register */
 496        while (&dev->ch[channel] != ch) {
 497            channel++;
 498        }
 499        block = channel / 2;
 500        dev->blk[block].isr |= ISR_RXRDY(channel);
 501        ch->sr |= SR_RXRDY;
 502        update_irq(dev, block);
 503    }
 504}
 505
 506static void hostdev_event(void *opaque, int event)
 507{
 508    SCC2698Channel *ch = opaque;
 509    switch (event) {
 510    case CHR_EVENT_OPENED:
 511        DPRINTF("Device %s opened\n", ch->dev->label);
 512        break;
 513    case CHR_EVENT_BREAK: {
 514        uint8_t zero = 0;
 515        DPRINTF("Device %s received break\n", ch->dev->label);
 516
 517        if (!(ch->sr & SR_BREAK)) {
 518            IPOctalState *dev = ch->ipoctal;
 519            unsigned block, channel = 0;
 520
 521            while (&dev->ch[channel] != ch) {
 522                channel++;
 523            }
 524            block = channel / 2;
 525
 526            ch->sr |= SR_BREAK;
 527            dev->blk[block].isr |= ISR_BREAK(channel);
 528        }
 529
 530        /* Put a zero character in the buffer */
 531        hostdev_receive(ch, &zero, 1);
 532    }
 533        break;
 534    default:
 535        DPRINTF("Device %s received event %d\n", ch->dev->label, event);
 536    }
 537}
 538
 539static void ipoctal_realize(DeviceState *dev, Error **errp)
 540{
 541    IPOctalState *s = IPOCTAL(dev);
 542    unsigned i;
 543
 544    for (i = 0; i < N_CHANNELS; i++) {
 545        SCC2698Channel *ch = &s->ch[i];
 546        ch->ipoctal = s;
 547
 548        /* Redirect IP-Octal channels to host character devices */
 549        if (qemu_chr_fe_backend_connected(&ch->dev)) {
 550            qemu_chr_fe_set_handlers(&ch->dev, hostdev_can_receive,
 551                                     hostdev_receive, hostdev_event,
 552                                     NULL, ch, NULL, true);
 553            DPRINTF("Redirecting channel %u to %s\n", i, ch->dev->label);
 554        } else {
 555            DPRINTF("Could not redirect channel %u, no chardev set\n", i);
 556        }
 557    }
 558}
 559
 560static Property ipoctal_properties[] = {
 561    DEFINE_PROP_CHR("chardev0", IPOctalState, ch[0].dev),
 562    DEFINE_PROP_CHR("chardev1", IPOctalState, ch[1].dev),
 563    DEFINE_PROP_CHR("chardev2", IPOctalState, ch[2].dev),
 564    DEFINE_PROP_CHR("chardev3", IPOctalState, ch[3].dev),
 565    DEFINE_PROP_CHR("chardev4", IPOctalState, ch[4].dev),
 566    DEFINE_PROP_CHR("chardev5", IPOctalState, ch[5].dev),
 567    DEFINE_PROP_CHR("chardev6", IPOctalState, ch[6].dev),
 568    DEFINE_PROP_CHR("chardev7", IPOctalState, ch[7].dev),
 569    DEFINE_PROP_END_OF_LIST(),
 570};
 571
 572static void ipoctal_class_init(ObjectClass *klass, void *data)
 573{
 574    DeviceClass *dc = DEVICE_CLASS(klass);
 575    IPackDeviceClass *ic = IPACK_DEVICE_CLASS(klass);
 576
 577    ic->realize     = ipoctal_realize;
 578    ic->io_read     = io_read;
 579    ic->io_write    = io_write;
 580    ic->id_read     = id_read;
 581    ic->id_write    = id_write;
 582    ic->int_read    = int_read;
 583    ic->int_write   = int_write;
 584    ic->mem_read16  = mem_read16;
 585    ic->mem_write16 = mem_write16;
 586    ic->mem_read8   = mem_read8;
 587    ic->mem_write8  = mem_write8;
 588
 589    set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
 590    dc->desc    = "GE IP-Octal 232 8-channel RS-232 IndustryPack";
 591    dc->props   = ipoctal_properties;
 592    dc->vmsd    = &vmstate_ipoctal;
 593}
 594
 595static const TypeInfo ipoctal_info = {
 596    .name          = TYPE_IPOCTAL,
 597    .parent        = TYPE_IPACK_DEVICE,
 598    .instance_size = sizeof(IPOctalState),
 599    .class_init    = ipoctal_class_init,
 600};
 601
 602static void ipoctal_register_types(void)
 603{
 604    type_register_static(&ipoctal_info);
 605}
 606
 607type_init(ipoctal_register_types)
 608