qemu/hw/char/renesas_sci.c
<<
>>
Prefs
   1/*
   2 * Renesas Serial Communication Interface
   3 *
   4 * Datasheet: RX62N Group, RX621 Group User's Manual: Hardware
   5 *            (Rev.1.40 R01UH0033EJ0140)
   6 *
   7 * Copyright (c) 2019 Yoshinori Sato
   8 *
   9 * SPDX-License-Identifier: GPL-2.0-or-later
  10 *
  11 * This program is free software; you can redistribute it and/or modify it
  12 * under the terms and conditions of the GNU General Public License,
  13 * version 2 or later, as published by the Free Software Foundation.
  14 *
  15 * This program is distributed in the hope it will be useful, but WITHOUT
  16 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  17 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  18 * more details.
  19 *
  20 * You should have received a copy of the GNU General Public License along with
  21 * this program.  If not, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24#include "qemu/osdep.h"
  25#include "qemu/log.h"
  26#include "hw/irq.h"
  27#include "hw/registerfields.h"
  28#include "hw/qdev-properties.h"
  29#include "hw/qdev-properties-system.h"
  30#include "hw/char/renesas_sci.h"
  31#include "migration/vmstate.h"
  32
  33/* SCI register map */
  34REG8(SMR, 0)
  35  FIELD(SMR, CKS,  0, 2)
  36  FIELD(SMR, MP,   2, 1)
  37  FIELD(SMR, STOP, 3, 1)
  38  FIELD(SMR, PM,   4, 1)
  39  FIELD(SMR, PE,   5, 1)
  40  FIELD(SMR, CHR,  6, 1)
  41  FIELD(SMR, CM,   7, 1)
  42REG8(BRR, 1)
  43REG8(SCR, 2)
  44  FIELD(SCR, CKE,  0, 2)
  45  FIELD(SCR, TEIE, 2, 1)
  46  FIELD(SCR, MPIE, 3, 1)
  47  FIELD(SCR, RE,   4, 1)
  48  FIELD(SCR, TE,   5, 1)
  49  FIELD(SCR, RIE,  6, 1)
  50  FIELD(SCR, TIE,  7, 1)
  51REG8(TDR, 3)
  52REG8(SSR, 4)
  53  FIELD(SSR, MPBT, 0, 1)
  54  FIELD(SSR, MPB,  1, 1)
  55  FIELD(SSR, TEND, 2, 1)
  56  FIELD(SSR, ERR,  3, 3)
  57    FIELD(SSR, PER,  3, 1)
  58    FIELD(SSR, FER,  4, 1)
  59    FIELD(SSR, ORER, 5, 1)
  60  FIELD(SSR, RDRF, 6, 1)
  61  FIELD(SSR, TDRE, 7, 1)
  62REG8(RDR, 5)
  63REG8(SCMR, 6)
  64  FIELD(SCMR, SMIF, 0, 1)
  65  FIELD(SCMR, SINV, 2, 1)
  66  FIELD(SCMR, SDIR, 3, 1)
  67  FIELD(SCMR, BCP2, 7, 1)
  68REG8(SEMR, 7)
  69  FIELD(SEMR, ACS0, 0, 1)
  70  FIELD(SEMR, ABCS, 4, 1)
  71
  72static int can_receive(void *opaque)
  73{
  74    RSCIState *sci = RSCI(opaque);
  75    if (sci->rx_next > qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL)) {
  76        return 0;
  77    } else {
  78        return FIELD_EX8(sci->scr, SCR, RE);
  79    }
  80}
  81
  82static void receive(void *opaque, const uint8_t *buf, int size)
  83{
  84    RSCIState *sci = RSCI(opaque);
  85    sci->rx_next = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + sci->trtime;
  86    if (FIELD_EX8(sci->ssr, SSR, RDRF) || size > 1) {
  87        sci->ssr = FIELD_DP8(sci->ssr, SSR, ORER, 1);
  88        if (FIELD_EX8(sci->scr, SCR, RIE)) {
  89            qemu_set_irq(sci->irq[ERI], 1);
  90        }
  91    } else {
  92        sci->rdr = buf[0];
  93        sci->ssr = FIELD_DP8(sci->ssr, SSR, RDRF, 1);
  94        if (FIELD_EX8(sci->scr, SCR, RIE)) {
  95            qemu_irq_pulse(sci->irq[RXI]);
  96        }
  97    }
  98}
  99
 100static void send_byte(RSCIState *sci)
 101{
 102    if (qemu_chr_fe_backend_connected(&sci->chr)) {
 103        qemu_chr_fe_write_all(&sci->chr, &sci->tdr, 1);
 104    }
 105    timer_mod(&sci->timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + sci->trtime);
 106    sci->ssr = FIELD_DP8(sci->ssr, SSR, TEND, 0);
 107    sci->ssr = FIELD_DP8(sci->ssr, SSR, TDRE, 1);
 108    qemu_set_irq(sci->irq[TEI], 0);
 109    if (FIELD_EX8(sci->scr, SCR, TIE)) {
 110        qemu_irq_pulse(sci->irq[TXI]);
 111    }
 112}
 113
 114static void txend(void *opaque)
 115{
 116    RSCIState *sci = RSCI(opaque);
 117    if (!FIELD_EX8(sci->ssr, SSR, TDRE)) {
 118        send_byte(sci);
 119    } else {
 120        sci->ssr = FIELD_DP8(sci->ssr, SSR, TEND, 1);
 121        if (FIELD_EX8(sci->scr, SCR, TEIE)) {
 122            qemu_set_irq(sci->irq[TEI], 1);
 123        }
 124    }
 125}
 126
 127static void update_trtime(RSCIState *sci)
 128{
 129    /* char per bits */
 130    sci->trtime = 8 - FIELD_EX8(sci->smr, SMR, CHR);
 131    sci->trtime += FIELD_EX8(sci->smr, SMR, PE);
 132    sci->trtime += FIELD_EX8(sci->smr, SMR, STOP) + 1;
 133    /* x bit transmit time (32 * divrate * brr) / base freq */
 134    sci->trtime *= 32 * sci->brr;
 135    sci->trtime *= 1 << (2 * FIELD_EX8(sci->smr, SMR, CKS));
 136    sci->trtime *= NANOSECONDS_PER_SECOND;
 137    sci->trtime /= sci->input_freq;
 138}
 139
 140static bool sci_is_tr_enabled(RSCIState *sci)
 141{
 142    return FIELD_EX8(sci->scr, SCR, TE) || FIELD_EX8(sci->scr, SCR, RE);
 143}
 144
 145static void sci_write(void *opaque, hwaddr offset, uint64_t val, unsigned size)
 146{
 147    RSCIState *sci = RSCI(opaque);
 148
 149    switch (offset) {
 150    case A_SMR:
 151        if (!sci_is_tr_enabled(sci)) {
 152            sci->smr = val;
 153            update_trtime(sci);
 154        }
 155        break;
 156    case A_BRR:
 157        if (!sci_is_tr_enabled(sci)) {
 158            sci->brr = val;
 159            update_trtime(sci);
 160        }
 161        break;
 162    case A_SCR:
 163        sci->scr = val;
 164        if (FIELD_EX8(sci->scr, SCR, TE)) {
 165            sci->ssr = FIELD_DP8(sci->ssr, SSR, TDRE, 1);
 166            sci->ssr = FIELD_DP8(sci->ssr, SSR, TEND, 1);
 167            if (FIELD_EX8(sci->scr, SCR, TIE)) {
 168                qemu_irq_pulse(sci->irq[TXI]);
 169            }
 170        }
 171        if (!FIELD_EX8(sci->scr, SCR, TEIE)) {
 172            qemu_set_irq(sci->irq[TEI], 0);
 173        }
 174        if (!FIELD_EX8(sci->scr, SCR, RIE)) {
 175            qemu_set_irq(sci->irq[ERI], 0);
 176        }
 177        break;
 178    case A_TDR:
 179        sci->tdr = val;
 180        if (FIELD_EX8(sci->ssr, SSR, TEND)) {
 181            send_byte(sci);
 182        } else {
 183            sci->ssr = FIELD_DP8(sci->ssr, SSR, TDRE, 0);
 184        }
 185        break;
 186    case A_SSR:
 187        sci->ssr = FIELD_DP8(sci->ssr, SSR, MPBT,
 188                             FIELD_EX8(val, SSR, MPBT));
 189        sci->ssr = FIELD_DP8(sci->ssr, SSR, ERR,
 190                             FIELD_EX8(val, SSR, ERR) & 0x07);
 191        if (FIELD_EX8(sci->read_ssr, SSR, ERR) &&
 192            FIELD_EX8(sci->ssr, SSR, ERR) == 0) {
 193            qemu_set_irq(sci->irq[ERI], 0);
 194        }
 195        break;
 196    case A_RDR:
 197        qemu_log_mask(LOG_GUEST_ERROR, "reneas_sci: RDR is read only.\n");
 198        break;
 199    case A_SCMR:
 200        sci->scmr = val; break;
 201    case A_SEMR: /* SEMR */
 202        sci->semr = val; break;
 203    default:
 204        qemu_log_mask(LOG_UNIMP, "renesas_sci: Register 0x%" HWADDR_PRIX " "
 205                                 "not implemented\n",
 206                      offset);
 207    }
 208}
 209
 210static uint64_t sci_read(void *opaque, hwaddr offset, unsigned size)
 211{
 212    RSCIState *sci = RSCI(opaque);
 213
 214    switch (offset) {
 215    case A_SMR:
 216        return sci->smr;
 217    case A_BRR:
 218        return sci->brr;
 219    case A_SCR:
 220        return sci->scr;
 221    case A_TDR:
 222        return sci->tdr;
 223    case A_SSR:
 224        sci->read_ssr = sci->ssr;
 225        return sci->ssr;
 226    case A_RDR:
 227        sci->ssr = FIELD_DP8(sci->ssr, SSR, RDRF, 0);
 228        return sci->rdr;
 229    case A_SCMR:
 230        return sci->scmr;
 231    case A_SEMR:
 232        return sci->semr;
 233    default:
 234        qemu_log_mask(LOG_UNIMP, "renesas_sci: Register 0x%" HWADDR_PRIX
 235                      " not implemented.\n", offset);
 236    }
 237    return UINT64_MAX;
 238}
 239
 240static const MemoryRegionOps sci_ops = {
 241    .write = sci_write,
 242    .read  = sci_read,
 243    .endianness = DEVICE_NATIVE_ENDIAN,
 244    .impl.max_access_size = 1,
 245    .valid.max_access_size = 1,
 246};
 247
 248static void rsci_reset(DeviceState *dev)
 249{
 250    RSCIState *sci = RSCI(dev);
 251    sci->smr = sci->scr = 0x00;
 252    sci->brr = 0xff;
 253    sci->tdr = 0xff;
 254    sci->rdr = 0x00;
 255    sci->ssr = 0x84;
 256    sci->scmr = 0x00;
 257    sci->semr = 0x00;
 258    sci->rx_next = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
 259}
 260
 261static void sci_event(void *opaque, QEMUChrEvent event)
 262{
 263    RSCIState *sci = RSCI(opaque);
 264    if (event == CHR_EVENT_BREAK) {
 265        sci->ssr = FIELD_DP8(sci->ssr, SSR, FER, 1);
 266        if (FIELD_EX8(sci->scr, SCR, RIE)) {
 267            qemu_set_irq(sci->irq[ERI], 1);
 268        }
 269    }
 270}
 271
 272static void rsci_realize(DeviceState *dev, Error **errp)
 273{
 274    RSCIState *sci = RSCI(dev);
 275
 276    if (sci->input_freq == 0) {
 277        qemu_log_mask(LOG_GUEST_ERROR,
 278                      "renesas_sci: input-freq property must be set.");
 279        return;
 280    }
 281    qemu_chr_fe_set_handlers(&sci->chr, can_receive, receive,
 282                             sci_event, NULL, sci, NULL, true);
 283}
 284
 285static void rsci_init(Object *obj)
 286{
 287    SysBusDevice *d = SYS_BUS_DEVICE(obj);
 288    RSCIState *sci = RSCI(obj);
 289    int i;
 290
 291    memory_region_init_io(&sci->memory, OBJECT(sci), &sci_ops,
 292                          sci, "renesas-sci", 0x8);
 293    sysbus_init_mmio(d, &sci->memory);
 294
 295    for (i = 0; i < SCI_NR_IRQ; i++) {
 296        sysbus_init_irq(d, &sci->irq[i]);
 297    }
 298    timer_init_ns(&sci->timer, QEMU_CLOCK_VIRTUAL, txend, sci);
 299}
 300
 301static const VMStateDescription vmstate_rsci = {
 302    .name = "renesas-sci",
 303    .version_id = 1,
 304    .minimum_version_id = 1,
 305    .fields = (VMStateField[]) {
 306        VMSTATE_INT64(trtime, RSCIState),
 307        VMSTATE_INT64(rx_next, RSCIState),
 308        VMSTATE_UINT8(smr, RSCIState),
 309        VMSTATE_UINT8(brr, RSCIState),
 310        VMSTATE_UINT8(scr, RSCIState),
 311        VMSTATE_UINT8(tdr, RSCIState),
 312        VMSTATE_UINT8(ssr, RSCIState),
 313        VMSTATE_UINT8(rdr, RSCIState),
 314        VMSTATE_UINT8(scmr, RSCIState),
 315        VMSTATE_UINT8(semr, RSCIState),
 316        VMSTATE_UINT8(read_ssr, RSCIState),
 317        VMSTATE_TIMER(timer, RSCIState),
 318        VMSTATE_END_OF_LIST()
 319    }
 320};
 321
 322static Property rsci_properties[] = {
 323    DEFINE_PROP_UINT64("input-freq", RSCIState, input_freq, 0),
 324    DEFINE_PROP_CHR("chardev", RSCIState, chr),
 325    DEFINE_PROP_END_OF_LIST(),
 326};
 327
 328static void rsci_class_init(ObjectClass *klass, void *data)
 329{
 330    DeviceClass *dc = DEVICE_CLASS(klass);
 331
 332    dc->realize = rsci_realize;
 333    dc->vmsd = &vmstate_rsci;
 334    dc->reset = rsci_reset;
 335    device_class_set_props(dc, rsci_properties);
 336}
 337
 338static const TypeInfo rsci_info = {
 339    .name = TYPE_RENESAS_SCI,
 340    .parent = TYPE_SYS_BUS_DEVICE,
 341    .instance_size = sizeof(RSCIState),
 342    .instance_init = rsci_init,
 343    .class_init = rsci_class_init,
 344};
 345
 346static void rsci_register_types(void)
 347{
 348    type_register_static(&rsci_info);
 349}
 350
 351type_init(rsci_register_types)
 352