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