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 "hw/qdev-properties-system.h"
  16#include "migration/vmstate.h"
  17#include "qemu/bitops.h"
  18#include "qemu/module.h"
  19#include "chardev/char-fe.h"
  20#include "qom/object.h"
  21
  22/* #define DEBUG_IPOCTAL */
  23
  24#ifdef DEBUG_IPOCTAL
  25#define DPRINTF2(fmt, ...) \
  26    do { fprintf(stderr, fmt, ## __VA_ARGS__); } while (0)
  27#else
  28#define DPRINTF2(fmt, ...) do { } while (0)
  29#endif
  30
  31#define DPRINTF(fmt, ...) DPRINTF2("IP-Octal: " fmt, ## __VA_ARGS__)
  32
  33#define RX_FIFO_SIZE 3
  34
  35/* The IP-Octal has 8 channels (a-h)
  36   divided into 4 blocks (A-D) */
  37#define N_CHANNELS 8
  38#define N_BLOCKS   4
  39
  40#define REG_MRa  0x01
  41#define REG_MRb  0x11
  42#define REG_SRa  0x03
  43#define REG_SRb  0x13
  44#define REG_CSRa 0x03
  45#define REG_CSRb 0x13
  46#define REG_CRa  0x05
  47#define REG_CRb  0x15
  48#define REG_RHRa 0x07
  49#define REG_RHRb 0x17
  50#define REG_THRa 0x07
  51#define REG_THRb 0x17
  52#define REG_ACR  0x09
  53#define REG_ISR  0x0B
  54#define REG_IMR  0x0B
  55#define REG_OPCR 0x1B
  56
  57#define CR_ENABLE_RX    BIT(0)
  58#define CR_DISABLE_RX   BIT(1)
  59#define CR_ENABLE_TX    BIT(2)
  60#define CR_DISABLE_TX   BIT(3)
  61#define CR_CMD(cr)      ((cr) >> 4)
  62#define CR_NO_OP        0
  63#define CR_RESET_MR     1
  64#define CR_RESET_RX     2
  65#define CR_RESET_TX     3
  66#define CR_RESET_ERR    4
  67#define CR_RESET_BRKINT 5
  68#define CR_START_BRK    6
  69#define CR_STOP_BRK     7
  70#define CR_ASSERT_RTSN  8
  71#define CR_NEGATE_RTSN  9
  72#define CR_TIMEOUT_ON   10
  73#define CR_TIMEOUT_OFF  12
  74
  75#define SR_RXRDY   BIT(0)
  76#define SR_FFULL   BIT(1)
  77#define SR_TXRDY   BIT(2)
  78#define SR_TXEMT   BIT(3)
  79#define SR_OVERRUN BIT(4)
  80#define SR_PARITY  BIT(5)
  81#define SR_FRAMING BIT(6)
  82#define SR_BREAK   BIT(7)
  83
  84#define ISR_TXRDYA BIT(0)
  85#define ISR_RXRDYA BIT(1)
  86#define ISR_BREAKA BIT(2)
  87#define ISR_CNTRDY BIT(3)
  88#define ISR_TXRDYB BIT(4)
  89#define ISR_RXRDYB BIT(5)
  90#define ISR_BREAKB BIT(6)
  91#define ISR_MPICHG BIT(7)
  92#define ISR_TXRDY(CH) (((CH) & 1) ? BIT(4) : BIT(0))
  93#define ISR_RXRDY(CH) (((CH) & 1) ? BIT(5) : BIT(1))
  94#define ISR_BREAK(CH) (((CH) & 1) ? BIT(6) : BIT(2))
  95
  96typedef struct IPOctalState IPOctalState;
  97typedef struct SCC2698Channel SCC2698Channel;
  98typedef struct SCC2698Block SCC2698Block;
  99
 100struct SCC2698Channel {
 101    IPOctalState *ipoctal;
 102    CharBackend dev;
 103    bool rx_enabled;
 104    uint8_t mr[2];
 105    uint8_t mr_idx;
 106    uint8_t sr;
 107    uint8_t rhr[RX_FIFO_SIZE];
 108    uint8_t rhr_idx;
 109    uint8_t rx_pending;
 110};
 111
 112struct SCC2698Block {
 113    uint8_t imr;
 114    uint8_t isr;
 115};
 116
 117struct IPOctalState {
 118    IPackDevice parent_obj;
 119
 120    SCC2698Channel ch[N_CHANNELS];
 121    SCC2698Block blk[N_BLOCKS];
 122    uint8_t irq_vector;
 123};
 124
 125#define TYPE_IPOCTAL "ipoctal232"
 126
 127OBJECT_DECLARE_SIMPLE_TYPE(IPOctalState, IPOCTAL)
 128
 129static const VMStateDescription vmstate_scc2698_channel = {
 130    .name = "scc2698_channel",
 131    .version_id = 1,
 132    .minimum_version_id = 1,
 133    .fields = (VMStateField[]) {
 134        VMSTATE_BOOL(rx_enabled, SCC2698Channel),
 135        VMSTATE_UINT8_ARRAY(mr, SCC2698Channel, 2),
 136        VMSTATE_UINT8(mr_idx, SCC2698Channel),
 137        VMSTATE_UINT8(sr, SCC2698Channel),
 138        VMSTATE_UINT8_ARRAY(rhr, SCC2698Channel, RX_FIFO_SIZE),
 139        VMSTATE_UINT8(rhr_idx, SCC2698Channel),
 140        VMSTATE_UINT8(rx_pending, SCC2698Channel),
 141        VMSTATE_END_OF_LIST()
 142    }
 143};
 144
 145static const VMStateDescription vmstate_scc2698_block = {
 146    .name = "scc2698_block",
 147    .version_id = 1,
 148    .minimum_version_id = 1,
 149    .fields = (VMStateField[]) {
 150        VMSTATE_UINT8(imr, SCC2698Block),
 151        VMSTATE_UINT8(isr, SCC2698Block),
 152        VMSTATE_END_OF_LIST()
 153    }
 154};
 155
 156static const VMStateDescription vmstate_ipoctal = {
 157    .name = "ipoctal232",
 158    .version_id = 1,
 159    .minimum_version_id = 1,
 160    .fields = (VMStateField[]) {
 161        VMSTATE_IPACK_DEVICE(parent_obj, IPOctalState),
 162        VMSTATE_STRUCT_ARRAY(ch, IPOctalState, N_CHANNELS, 1,
 163                             vmstate_scc2698_channel, SCC2698Channel),
 164        VMSTATE_STRUCT_ARRAY(blk, IPOctalState, N_BLOCKS, 1,
 165                             vmstate_scc2698_block, SCC2698Block),
 166        VMSTATE_UINT8(irq_vector, IPOctalState),
 167        VMSTATE_END_OF_LIST()
 168    }
 169};
 170
 171/* data[10] is 0x0C, not 0x0B as the doc says */
 172static const uint8_t id_prom_data[] = {
 173    0x49, 0x50, 0x41, 0x43, 0xF0, 0x22,
 174    0xA1, 0x00, 0x00, 0x00, 0x0C, 0xCC
 175};
 176
 177static void update_irq(IPOctalState *dev, unsigned block)
 178{
 179    IPackDevice *idev = IPACK_DEVICE(dev);
 180    /* Blocks A and B interrupt on INT0#, C and D on INT1#.
 181       Thus, to get the status we have to check two blocks. */
 182    SCC2698Block *blk0 = &dev->blk[block];
 183    SCC2698Block *blk1 = &dev->blk[block^1];
 184    unsigned intno = block / 2;
 185
 186    if ((blk0->isr & blk0->imr) || (blk1->isr & blk1->imr)) {
 187        qemu_irq_raise(idev->irq[intno]);
 188    } else {
 189        qemu_irq_lower(idev->irq[intno]);
 190    }
 191}
 192
 193static void write_cr(IPOctalState *dev, unsigned channel, uint8_t val)
 194{
 195    SCC2698Channel *ch = &dev->ch[channel];
 196    SCC2698Block *blk = &dev->blk[channel / 2];
 197
 198    DPRINTF("Write CR%c %u: ", channel + 'a', val);
 199
 200    /* The lower 4 bits are used to enable and disable Tx and Rx */
 201    if (val & CR_ENABLE_RX) {
 202        DPRINTF2("Rx on, ");
 203        ch->rx_enabled = true;
 204    }
 205    if (val & CR_DISABLE_RX) {
 206        DPRINTF2("Rx off, ");
 207        ch->rx_enabled = false;
 208    }
 209    if (val & CR_ENABLE_TX) {
 210        DPRINTF2("Tx on, ");
 211        ch->sr |= SR_TXRDY | SR_TXEMT;
 212        blk->isr |= ISR_TXRDY(channel);
 213    }
 214    if (val & CR_DISABLE_TX) {
 215        DPRINTF2("Tx off, ");
 216        ch->sr &= ~(SR_TXRDY | SR_TXEMT);
 217        blk->isr &= ~ISR_TXRDY(channel);
 218    }
 219
 220    DPRINTF2("cmd: ");
 221
 222    /* The rest of the bits implement different commands */
 223    switch (CR_CMD(val)) {
 224    case CR_NO_OP:
 225        DPRINTF2("none");
 226        break;
 227    case CR_RESET_MR:
 228        DPRINTF2("reset MR");
 229        ch->mr_idx = 0;
 230        break;
 231    case CR_RESET_RX:
 232        DPRINTF2("reset Rx");
 233        ch->rx_enabled = false;
 234        ch->rx_pending = 0;
 235        ch->sr &= ~SR_RXRDY;
 236        blk->isr &= ~ISR_RXRDY(channel);
 237        break;
 238    case CR_RESET_TX:
 239        DPRINTF2("reset Tx");
 240        ch->sr &= ~(SR_TXRDY | SR_TXEMT);
 241        blk->isr &= ~ISR_TXRDY(channel);
 242        break;
 243    case CR_RESET_ERR:
 244        DPRINTF2("reset err");
 245        ch->sr &= ~(SR_OVERRUN | SR_PARITY | SR_FRAMING | SR_BREAK);
 246        break;
 247    case CR_RESET_BRKINT:
 248        DPRINTF2("reset brk ch int");
 249        blk->isr &= ~(ISR_BREAKA | ISR_BREAKB);
 250        break;
 251    default:
 252        DPRINTF2("unsupported 0x%x", CR_CMD(val));
 253    }
 254
 255    DPRINTF2("\n");
 256}
 257
 258static uint16_t io_read(IPackDevice *ip, uint8_t addr)
 259{
 260    IPOctalState *dev = IPOCTAL(ip);
 261    uint16_t ret = 0;
 262    /* addr[7:6]: block   (A-D)
 263       addr[7:5]: channel (a-h)
 264       addr[5:0]: register */
 265    unsigned block = addr >> 5;
 266    unsigned channel = addr >> 4;
 267    /* Big endian, accessed using 8-bit bytes at odd locations */
 268    unsigned offset = (addr & 0x1F) ^ 1;
 269    SCC2698Channel *ch = &dev->ch[channel];
 270    SCC2698Block *blk = &dev->blk[block];
 271    uint8_t old_isr = blk->isr;
 272
 273    switch (offset) {
 274
 275    case REG_MRa:
 276    case REG_MRb:
 277        ret = ch->mr[ch->mr_idx];
 278        DPRINTF("Read MR%u%c: 0x%x\n", ch->mr_idx + 1, channel + 'a', ret);
 279        ch->mr_idx = 1;
 280        break;
 281
 282    case REG_SRa:
 283    case REG_SRb:
 284        ret = ch->sr;
 285        DPRINTF("Read SR%c: 0x%x\n", channel + 'a', ret);
 286        break;
 287
 288    case REG_RHRa:
 289    case REG_RHRb:
 290        ret = ch->rhr[ch->rhr_idx];
 291        if (ch->rx_pending > 0) {
 292            ch->rx_pending--;
 293            if (ch->rx_pending == 0) {
 294                ch->sr &= ~SR_RXRDY;
 295                blk->isr &= ~ISR_RXRDY(channel);
 296                qemu_chr_fe_accept_input(&ch->dev);
 297            } else {
 298                ch->rhr_idx = (ch->rhr_idx + 1) % RX_FIFO_SIZE;
 299            }
 300            if (ch->sr & SR_BREAK) {
 301                ch->sr &= ~SR_BREAK;
 302                blk->isr |= ISR_BREAK(channel);
 303            }
 304        }
 305        DPRINTF("Read RHR%c (0x%x)\n", channel + 'a', ret);
 306        break;
 307
 308    case REG_ISR:
 309        ret = blk->isr;
 310        DPRINTF("Read ISR%c: 0x%x\n", block + 'A', ret);
 311        break;
 312
 313    default:
 314        DPRINTF("Read unknown/unsupported register 0x%02x\n", offset);
 315    }
 316
 317    if (old_isr != blk->isr) {
 318        update_irq(dev, block);
 319    }
 320
 321    return ret;
 322}
 323
 324static void io_write(IPackDevice *ip, uint8_t addr, uint16_t val)
 325{
 326    IPOctalState *dev = IPOCTAL(ip);
 327    unsigned reg = val & 0xFF;
 328    /* addr[7:6]: block   (A-D)
 329       addr[7:5]: channel (a-h)
 330       addr[5:0]: register */
 331    unsigned block = addr >> 5;
 332    unsigned channel = addr >> 4;
 333    /* Big endian, accessed using 8-bit bytes at odd locations */
 334    unsigned offset = (addr & 0x1F) ^ 1;
 335    SCC2698Channel *ch = &dev->ch[channel];
 336    SCC2698Block *blk = &dev->blk[block];
 337    uint8_t old_isr = blk->isr;
 338    uint8_t old_imr = blk->imr;
 339
 340    switch (offset) {
 341
 342    case REG_MRa:
 343    case REG_MRb:
 344        ch->mr[ch->mr_idx] = reg;
 345        DPRINTF("Write MR%u%c 0x%x\n", ch->mr_idx + 1, channel + 'a', reg);
 346        ch->mr_idx = 1;
 347        break;
 348
 349    /* Not implemented */
 350    case REG_CSRa:
 351    case REG_CSRb:
 352        DPRINTF("Write CSR%c: 0x%x\n", channel + 'a', reg);
 353        break;
 354
 355    case REG_CRa:
 356    case REG_CRb:
 357        write_cr(dev, channel, reg);
 358        break;
 359
 360    case REG_THRa:
 361    case REG_THRb:
 362        if (ch->sr & SR_TXRDY) {
 363            uint8_t thr = reg;
 364            DPRINTF("Write THR%c (0x%x)\n", channel + 'a', reg);
 365            /* XXX this blocks entire thread. Rewrite to use
 366             * qemu_chr_fe_write and background I/O callbacks */
 367            qemu_chr_fe_write_all(&ch->dev, &thr, 1);
 368        } else {
 369            DPRINTF("Write THR%c (0x%x), Tx disabled\n", channel + 'a', reg);
 370        }
 371        break;
 372
 373    /* Not implemented */
 374    case REG_ACR:
 375        DPRINTF("Write ACR%c 0x%x\n", block + 'A', val);
 376        break;
 377
 378    case REG_IMR:
 379        DPRINTF("Write IMR%c 0x%x\n", block + 'A', val);
 380        blk->imr = reg;
 381        break;
 382
 383    /* Not implemented */
 384    case REG_OPCR:
 385        DPRINTF("Write OPCR%c 0x%x\n", block + 'A', val);
 386        break;
 387
 388    default:
 389        DPRINTF("Write unknown/unsupported register 0x%02x %u\n", offset, val);
 390    }
 391
 392    if (old_isr != blk->isr || old_imr != blk->imr) {
 393        update_irq(dev, block);
 394    }
 395}
 396
 397static uint16_t id_read(IPackDevice *ip, uint8_t addr)
 398{
 399    uint16_t ret = 0;
 400    unsigned pos = addr / 2; /* The ID PROM data is stored every other byte */
 401
 402    if (pos < ARRAY_SIZE(id_prom_data)) {
 403        ret = id_prom_data[pos];
 404    } else {
 405        DPRINTF("Attempt to read unavailable PROM data at 0x%x\n",  addr);
 406    }
 407
 408    return ret;
 409}
 410
 411static void id_write(IPackDevice *ip, uint8_t addr, uint16_t val)
 412{
 413    IPOctalState *dev = IPOCTAL(ip);
 414    if (addr == 1) {
 415        DPRINTF("Write IRQ vector: %u\n", (unsigned) val);
 416        dev->irq_vector = val; /* Undocumented, but the hw works like that */
 417    } else {
 418        DPRINTF("Attempt to write 0x%x to 0x%x\n", val, addr);
 419    }
 420}
 421
 422static uint16_t int_read(IPackDevice *ip, uint8_t addr)
 423{
 424    IPOctalState *dev = IPOCTAL(ip);
 425    /* Read address 0 to ACK INT0# and address 2 to ACK INT1# */
 426    if (addr != 0 && addr != 2) {
 427        DPRINTF("Attempt to read from 0x%x\n", addr);
 428        return 0;
 429    } else {
 430        /* Update interrupts if necessary */
 431        update_irq(dev, addr);
 432        return dev->irq_vector;
 433    }
 434}
 435
 436static void int_write(IPackDevice *ip, uint8_t addr, uint16_t val)
 437{
 438    DPRINTF("Attempt to write 0x%x to 0x%x\n", val, addr);
 439}
 440
 441static uint16_t mem_read16(IPackDevice *ip, uint32_t addr)
 442{
 443    DPRINTF("Attempt to read from 0x%x\n", addr);
 444    return 0;
 445}
 446
 447static void mem_write16(IPackDevice *ip, uint32_t addr, uint16_t val)
 448{
 449    DPRINTF("Attempt to write 0x%x to 0x%x\n", val, addr);
 450}
 451
 452static uint8_t mem_read8(IPackDevice *ip, uint32_t addr)
 453{
 454    DPRINTF("Attempt to read from 0x%x\n", addr);
 455    return 0;
 456}
 457
 458static void mem_write8(IPackDevice *ip, uint32_t addr, uint8_t val)
 459{
 460    IPOctalState *dev = IPOCTAL(ip);
 461    if (addr == 1) {
 462        DPRINTF("Write IRQ vector: %u\n", (unsigned) val);
 463        dev->irq_vector = val;
 464    } else {
 465        DPRINTF("Attempt to write 0x%x to 0x%x\n", val, addr);
 466    }
 467}
 468
 469static int hostdev_can_receive(void *opaque)
 470{
 471    SCC2698Channel *ch = opaque;
 472    int available_bytes = RX_FIFO_SIZE - ch->rx_pending;
 473    return ch->rx_enabled ? available_bytes : 0;
 474}
 475
 476static void hostdev_receive(void *opaque, const uint8_t *buf, int size)
 477{
 478    SCC2698Channel *ch = opaque;
 479    IPOctalState *dev = ch->ipoctal;
 480    unsigned pos = ch->rhr_idx + ch->rx_pending;
 481    int i;
 482
 483    assert(size + ch->rx_pending <= RX_FIFO_SIZE);
 484
 485    /* Copy data to the RxFIFO */
 486    for (i = 0; i < size; i++) {
 487        pos %= RX_FIFO_SIZE;
 488        ch->rhr[pos++] = buf[i];
 489    }
 490
 491    ch->rx_pending += size;
 492
 493    /* If the RxFIFO was empty raise an interrupt */
 494    if (!(ch->sr & SR_RXRDY)) {
 495        unsigned block, channel = 0;
 496        /* Find channel number to update the ISR register */
 497        while (&dev->ch[channel] != ch) {
 498            channel++;
 499        }
 500        block = channel / 2;
 501        dev->blk[block].isr |= ISR_RXRDY(channel);
 502        ch->sr |= SR_RXRDY;
 503        update_irq(dev, block);
 504    }
 505}
 506
 507static void hostdev_event(void *opaque, QEMUChrEvent event)
 508{
 509    SCC2698Channel *ch = opaque;
 510    switch (event) {
 511    case CHR_EVENT_OPENED:
 512        DPRINTF("Device %s opened\n", ch->dev->label);
 513        break;
 514    case CHR_EVENT_BREAK: {
 515        uint8_t zero = 0;
 516        DPRINTF("Device %s received break\n", ch->dev->label);
 517
 518        if (!(ch->sr & SR_BREAK)) {
 519            IPOctalState *dev = ch->ipoctal;
 520            unsigned block, channel = 0;
 521
 522            while (&dev->ch[channel] != ch) {
 523                channel++;
 524            }
 525            block = channel / 2;
 526
 527            ch->sr |= SR_BREAK;
 528            dev->blk[block].isr |= ISR_BREAK(channel);
 529        }
 530
 531        /* Put a zero character in the buffer */
 532        hostdev_receive(ch, &zero, 1);
 533    }
 534        break;
 535    default:
 536        DPRINTF("Device %s received event %d\n", ch->dev->label, event);
 537    }
 538}
 539
 540static void ipoctal_realize(DeviceState *dev, Error **errp)
 541{
 542    IPOctalState *s = IPOCTAL(dev);
 543    unsigned i;
 544
 545    for (i = 0; i < N_CHANNELS; i++) {
 546        SCC2698Channel *ch = &s->ch[i];
 547        ch->ipoctal = s;
 548
 549        /* Redirect IP-Octal channels to host character devices */
 550        if (qemu_chr_fe_backend_connected(&ch->dev)) {
 551            qemu_chr_fe_set_handlers(&ch->dev, hostdev_can_receive,
 552                                     hostdev_receive, hostdev_event,
 553                                     NULL, ch, NULL, true);
 554            DPRINTF("Redirecting channel %u to %s\n", i, ch->dev->label);
 555        } else {
 556            DPRINTF("Could not redirect channel %u, no chardev set\n", i);
 557        }
 558    }
 559}
 560
 561static Property ipoctal_properties[] = {
 562    DEFINE_PROP_CHR("chardev0", IPOctalState, ch[0].dev),
 563    DEFINE_PROP_CHR("chardev1", IPOctalState, ch[1].dev),
 564    DEFINE_PROP_CHR("chardev2", IPOctalState, ch[2].dev),
 565    DEFINE_PROP_CHR("chardev3", IPOctalState, ch[3].dev),
 566    DEFINE_PROP_CHR("chardev4", IPOctalState, ch[4].dev),
 567    DEFINE_PROP_CHR("chardev5", IPOctalState, ch[5].dev),
 568    DEFINE_PROP_CHR("chardev6", IPOctalState, ch[6].dev),
 569    DEFINE_PROP_CHR("chardev7", IPOctalState, ch[7].dev),
 570    DEFINE_PROP_END_OF_LIST(),
 571};
 572
 573static void ipoctal_class_init(ObjectClass *klass, void *data)
 574{
 575    DeviceClass *dc = DEVICE_CLASS(klass);
 576    IPackDeviceClass *ic = IPACK_DEVICE_CLASS(klass);
 577
 578    ic->realize     = ipoctal_realize;
 579    ic->io_read     = io_read;
 580    ic->io_write    = io_write;
 581    ic->id_read     = id_read;
 582    ic->id_write    = id_write;
 583    ic->int_read    = int_read;
 584    ic->int_write   = int_write;
 585    ic->mem_read16  = mem_read16;
 586    ic->mem_write16 = mem_write16;
 587    ic->mem_read8   = mem_read8;
 588    ic->mem_write8  = mem_write8;
 589
 590    set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
 591    dc->desc    = "GE IP-Octal 232 8-channel RS-232 IndustryPack";
 592    device_class_set_props(dc, ipoctal_properties);
 593    dc->vmsd    = &vmstate_ipoctal;
 594}
 595
 596static const TypeInfo ipoctal_info = {
 597    .name          = TYPE_IPOCTAL,
 598    .parent        = TYPE_IPACK_DEVICE,
 599    .instance_size = sizeof(IPOctalState),
 600    .class_init    = ipoctal_class_init,
 601};
 602
 603static void ipoctal_register_types(void)
 604{
 605    type_register_static(&ipoctal_info);
 606}
 607
 608type_init(ipoctal_register_types)
 609