qemu/hw/sd/bcm2835_sdhost.c
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   1/*
   2 * Raspberry Pi (BCM2835) SD Host Controller
   3 *
   4 * Copyright (c) 2017 Antfield SAS
   5 *
   6 * Authors:
   7 *  Clement Deschamps <clement.deschamps@antfield.fr>
   8 *  Luc Michel <luc.michel@antfield.fr>
   9 *
  10 * This work is licensed under the terms of the GNU GPL, version 2 or later.
  11 * See the COPYING file in the top-level directory.
  12 */
  13
  14#include "qemu/osdep.h"
  15#include "qemu/log.h"
  16#include "qemu/module.h"
  17#include "sysemu/blockdev.h"
  18#include "hw/irq.h"
  19#include "hw/sd/bcm2835_sdhost.h"
  20#include "migration/vmstate.h"
  21#include "trace.h"
  22#include "qom/object.h"
  23
  24#define TYPE_BCM2835_SDHOST_BUS "bcm2835-sdhost-bus"
  25/* This is reusing the SDBus typedef from SD_BUS */
  26DECLARE_INSTANCE_CHECKER(SDBus, BCM2835_SDHOST_BUS,
  27                         TYPE_BCM2835_SDHOST_BUS)
  28
  29#define SDCMD  0x00 /* Command to SD card              - 16 R/W */
  30#define SDARG  0x04 /* Argument to SD card             - 32 R/W */
  31#define SDTOUT 0x08 /* Start value for timeout counter - 32 R/W */
  32#define SDCDIV 0x0c /* Start value for clock divider   - 11 R/W */
  33#define SDRSP0 0x10 /* SD card rsp (31:0)         - 32 R   */
  34#define SDRSP1 0x14 /* SD card rsp (63:32)        - 32 R   */
  35#define SDRSP2 0x18 /* SD card rsp (95:64)        - 32 R   */
  36#define SDRSP3 0x1c /* SD card rsp (127:96)       - 32 R   */
  37#define SDHSTS 0x20 /* SD host status                  - 11 R   */
  38#define SDVDD  0x30 /* SD card power control           -  1 R/W */
  39#define SDEDM  0x34 /* Emergency Debug Mode            - 13 R/W */
  40#define SDHCFG 0x38 /* Host configuration              -  2 R/W */
  41#define SDHBCT 0x3c /* Host byte count (debug)         - 32 R/W */
  42#define SDDATA 0x40 /* Data to/from SD card            - 32 R/W */
  43#define SDHBLC 0x50 /* Host block count (SDIO/SDHC)    -  9 R/W */
  44
  45#define SDCMD_NEW_FLAG                  0x8000
  46#define SDCMD_FAIL_FLAG                 0x4000
  47#define SDCMD_BUSYWAIT                  0x800
  48#define SDCMD_NO_RESPONSE               0x400
  49#define SDCMD_LONG_RESPONSE             0x200
  50#define SDCMD_WRITE_CMD                 0x80
  51#define SDCMD_READ_CMD                  0x40
  52#define SDCMD_CMD_MASK                  0x3f
  53
  54#define SDCDIV_MAX_CDIV                 0x7ff
  55
  56#define SDHSTS_BUSY_IRPT                0x400
  57#define SDHSTS_BLOCK_IRPT               0x200
  58#define SDHSTS_SDIO_IRPT                0x100
  59#define SDHSTS_REW_TIME_OUT             0x80
  60#define SDHSTS_CMD_TIME_OUT             0x40
  61#define SDHSTS_CRC16_ERROR              0x20
  62#define SDHSTS_CRC7_ERROR               0x10
  63#define SDHSTS_FIFO_ERROR               0x08
  64/* Reserved */
  65/* Reserved */
  66#define SDHSTS_DATA_FLAG                0x01
  67
  68#define SDHCFG_BUSY_IRPT_EN     (1 << 10)
  69#define SDHCFG_BLOCK_IRPT_EN    (1 << 8)
  70#define SDHCFG_SDIO_IRPT_EN     (1 << 5)
  71#define SDHCFG_DATA_IRPT_EN     (1 << 4)
  72#define SDHCFG_SLOW_CARD        (1 << 3)
  73#define SDHCFG_WIDE_EXT_BUS     (1 << 2)
  74#define SDHCFG_WIDE_INT_BUS     (1 << 1)
  75#define SDHCFG_REL_CMD_LINE     (1 << 0)
  76
  77#define SDEDM_FORCE_DATA_MODE   (1 << 19)
  78#define SDEDM_CLOCK_PULSE       (1 << 20)
  79#define SDEDM_BYPASS            (1 << 21)
  80
  81#define SDEDM_WRITE_THRESHOLD_SHIFT 9
  82#define SDEDM_READ_THRESHOLD_SHIFT 14
  83#define SDEDM_THRESHOLD_MASK     0x1f
  84
  85#define SDEDM_FSM_MASK           0xf
  86#define SDEDM_FSM_IDENTMODE      0x0
  87#define SDEDM_FSM_DATAMODE       0x1
  88#define SDEDM_FSM_READDATA       0x2
  89#define SDEDM_FSM_WRITEDATA      0x3
  90#define SDEDM_FSM_READWAIT       0x4
  91#define SDEDM_FSM_READCRC        0x5
  92#define SDEDM_FSM_WRITECRC       0x6
  93#define SDEDM_FSM_WRITEWAIT1     0x7
  94#define SDEDM_FSM_POWERDOWN      0x8
  95#define SDEDM_FSM_POWERUP        0x9
  96#define SDEDM_FSM_WRITESTART1    0xa
  97#define SDEDM_FSM_WRITESTART2    0xb
  98#define SDEDM_FSM_GENPULSES      0xc
  99#define SDEDM_FSM_WRITEWAIT2     0xd
 100#define SDEDM_FSM_STARTPOWDOWN   0xf
 101
 102#define SDDATA_FIFO_WORDS        16
 103
 104static void bcm2835_sdhost_update_irq(BCM2835SDHostState *s)
 105{
 106    uint32_t irq = s->status &
 107        (SDHSTS_BUSY_IRPT | SDHSTS_BLOCK_IRPT | SDHSTS_SDIO_IRPT);
 108    trace_bcm2835_sdhost_update_irq(irq);
 109    qemu_set_irq(s->irq, !!irq);
 110}
 111
 112static void bcm2835_sdhost_send_command(BCM2835SDHostState *s)
 113{
 114    SDRequest request;
 115    uint8_t rsp[16];
 116    int rlen;
 117
 118    request.cmd = s->cmd & SDCMD_CMD_MASK;
 119    request.arg = s->cmdarg;
 120
 121    rlen = sdbus_do_command(&s->sdbus, &request, rsp);
 122    if (rlen < 0) {
 123        goto error;
 124    }
 125    if (!(s->cmd & SDCMD_NO_RESPONSE)) {
 126        if (rlen == 0 || (rlen == 4 && (s->cmd & SDCMD_LONG_RESPONSE))) {
 127            goto error;
 128        }
 129        if (rlen != 4 && rlen != 16) {
 130            goto error;
 131        }
 132        if (rlen == 4) {
 133            s->rsp[0] = ldl_be_p(&rsp[0]);
 134            s->rsp[1] = s->rsp[2] = s->rsp[3] = 0;
 135        } else {
 136            s->rsp[0] = ldl_be_p(&rsp[12]);
 137            s->rsp[1] = ldl_be_p(&rsp[8]);
 138            s->rsp[2] = ldl_be_p(&rsp[4]);
 139            s->rsp[3] = ldl_be_p(&rsp[0]);
 140        }
 141    }
 142    /* We never really delay commands, so if this was a 'busywait' command
 143     * then we've completed it now and can raise the interrupt.
 144     */
 145    if ((s->cmd & SDCMD_BUSYWAIT) && (s->config & SDHCFG_BUSY_IRPT_EN)) {
 146        s->status |= SDHSTS_BUSY_IRPT;
 147    }
 148    return;
 149
 150error:
 151    s->cmd |= SDCMD_FAIL_FLAG;
 152    s->status |= SDHSTS_CMD_TIME_OUT;
 153}
 154
 155static void bcm2835_sdhost_fifo_push(BCM2835SDHostState *s, uint32_t value)
 156{
 157    int n;
 158
 159    if (s->fifo_len == BCM2835_SDHOST_FIFO_LEN) {
 160        /* FIFO overflow */
 161        return;
 162    }
 163    n = (s->fifo_pos + s->fifo_len) & (BCM2835_SDHOST_FIFO_LEN - 1);
 164    s->fifo_len++;
 165    s->fifo[n] = value;
 166}
 167
 168static uint32_t bcm2835_sdhost_fifo_pop(BCM2835SDHostState *s)
 169{
 170    uint32_t value;
 171
 172    if (s->fifo_len == 0) {
 173        /* FIFO underflow */
 174        return 0;
 175    }
 176    value = s->fifo[s->fifo_pos];
 177    s->fifo_len--;
 178    s->fifo_pos = (s->fifo_pos + 1) & (BCM2835_SDHOST_FIFO_LEN - 1);
 179    return value;
 180}
 181
 182static void bcm2835_sdhost_fifo_run(BCM2835SDHostState *s)
 183{
 184    uint32_t value = 0;
 185    int n;
 186    int is_read;
 187    int is_write;
 188
 189    is_read = (s->cmd & SDCMD_READ_CMD) != 0;
 190    is_write = (s->cmd & SDCMD_WRITE_CMD) != 0;
 191    if (s->datacnt != 0 && (is_write || sdbus_data_ready(&s->sdbus))) {
 192        if (is_read) {
 193            n = 0;
 194            while (s->datacnt && s->fifo_len < BCM2835_SDHOST_FIFO_LEN) {
 195                value |= (uint32_t)sdbus_read_byte(&s->sdbus) << (n * 8);
 196                s->datacnt--;
 197                n++;
 198                if (n == 4) {
 199                    bcm2835_sdhost_fifo_push(s, value);
 200                    s->status |= SDHSTS_DATA_FLAG;
 201                    if (s->config & SDHCFG_DATA_IRPT_EN) {
 202                        s->status |= SDHSTS_SDIO_IRPT;
 203                    }
 204                    n = 0;
 205                    value = 0;
 206                }
 207            }
 208            if (n != 0) {
 209                bcm2835_sdhost_fifo_push(s, value);
 210                s->status |= SDHSTS_DATA_FLAG;
 211                if (s->config & SDHCFG_DATA_IRPT_EN) {
 212                    s->status |= SDHSTS_SDIO_IRPT;
 213                }
 214            }
 215        } else if (is_write) { /* write */
 216            n = 0;
 217            while (s->datacnt > 0 && (s->fifo_len > 0 || n > 0)) {
 218                if (n == 0) {
 219                    value = bcm2835_sdhost_fifo_pop(s);
 220                    s->status |= SDHSTS_DATA_FLAG;
 221                    if (s->config & SDHCFG_DATA_IRPT_EN) {
 222                        s->status |= SDHSTS_SDIO_IRPT;
 223                    }
 224                    n = 4;
 225                }
 226                n--;
 227                s->datacnt--;
 228                sdbus_write_byte(&s->sdbus, value & 0xff);
 229                value >>= 8;
 230            }
 231        }
 232        if (s->datacnt == 0) {
 233            s->edm &= ~SDEDM_FSM_MASK;
 234            s->edm |= SDEDM_FSM_DATAMODE;
 235            trace_bcm2835_sdhost_edm_change("datacnt 0", s->edm);
 236        }
 237        if (is_write) {
 238            /* set block interrupt at end of each block transfer */
 239            if (s->hbct && s->datacnt % s->hbct == 0 &&
 240                (s->config & SDHCFG_BLOCK_IRPT_EN)) {
 241                s->status |= SDHSTS_BLOCK_IRPT;
 242            }
 243            /* set data interrupt after each transfer */
 244            s->status |= SDHSTS_DATA_FLAG;
 245            if (s->config & SDHCFG_DATA_IRPT_EN) {
 246                s->status |= SDHSTS_SDIO_IRPT;
 247            }
 248        }
 249    }
 250
 251    bcm2835_sdhost_update_irq(s);
 252
 253    s->edm &= ~(0x1f << 4);
 254    s->edm |= ((s->fifo_len & 0x1f) << 4);
 255    trace_bcm2835_sdhost_edm_change("fifo run", s->edm);
 256}
 257
 258static uint64_t bcm2835_sdhost_read(void *opaque, hwaddr offset,
 259    unsigned size)
 260{
 261    BCM2835SDHostState *s = (BCM2835SDHostState *)opaque;
 262    uint32_t res = 0;
 263
 264    switch (offset) {
 265    case SDCMD:
 266        res = s->cmd;
 267        break;
 268    case SDHSTS:
 269        res = s->status;
 270        break;
 271    case SDRSP0:
 272        res = s->rsp[0];
 273        break;
 274    case SDRSP1:
 275        res = s->rsp[1];
 276        break;
 277    case SDRSP2:
 278        res = s->rsp[2];
 279        break;
 280    case SDRSP3:
 281        res = s->rsp[3];
 282        break;
 283    case SDEDM:
 284        res = s->edm;
 285        break;
 286    case SDVDD:
 287        res = s->vdd;
 288        break;
 289    case SDDATA:
 290        res = bcm2835_sdhost_fifo_pop(s);
 291        bcm2835_sdhost_fifo_run(s);
 292        break;
 293    case SDHBCT:
 294        res = s->hbct;
 295        break;
 296    case SDHBLC:
 297        res = s->hblc;
 298        break;
 299
 300    default:
 301        qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
 302                      __func__, offset);
 303        res = 0;
 304        break;
 305    }
 306
 307    trace_bcm2835_sdhost_read(offset, res, size);
 308
 309    return res;
 310}
 311
 312static void bcm2835_sdhost_write(void *opaque, hwaddr offset,
 313    uint64_t value, unsigned size)
 314{
 315    BCM2835SDHostState *s = (BCM2835SDHostState *)opaque;
 316
 317    trace_bcm2835_sdhost_write(offset, value, size);
 318
 319    switch (offset) {
 320    case SDCMD:
 321        s->cmd = value;
 322        if (value & SDCMD_NEW_FLAG) {
 323            bcm2835_sdhost_send_command(s);
 324            bcm2835_sdhost_fifo_run(s);
 325            s->cmd &= ~SDCMD_NEW_FLAG;
 326        }
 327        break;
 328    case SDTOUT:
 329        break;
 330    case SDCDIV:
 331        break;
 332    case SDHSTS:
 333        s->status &= ~value;
 334        bcm2835_sdhost_update_irq(s);
 335        break;
 336    case SDARG:
 337        s->cmdarg = value;
 338        break;
 339    case SDEDM:
 340        if ((value & 0xf) == 0xf) {
 341            /* power down */
 342            value &= ~0xf;
 343        }
 344        s->edm = value;
 345        trace_bcm2835_sdhost_edm_change("guest register write", s->edm);
 346        break;
 347    case SDHCFG:
 348        s->config = value;
 349        bcm2835_sdhost_fifo_run(s);
 350        break;
 351    case SDVDD:
 352        s->vdd = value;
 353        break;
 354    case SDDATA:
 355        bcm2835_sdhost_fifo_push(s, value);
 356        bcm2835_sdhost_fifo_run(s);
 357        break;
 358    case SDHBCT:
 359        s->hbct = value;
 360        break;
 361    case SDHBLC:
 362        s->hblc = value;
 363        s->datacnt = s->hblc * s->hbct;
 364        bcm2835_sdhost_fifo_run(s);
 365        break;
 366
 367    default:
 368        qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
 369                      __func__, offset);
 370        break;
 371    }
 372}
 373
 374static const MemoryRegionOps bcm2835_sdhost_ops = {
 375    .read = bcm2835_sdhost_read,
 376    .write = bcm2835_sdhost_write,
 377    .endianness = DEVICE_NATIVE_ENDIAN,
 378};
 379
 380static const VMStateDescription vmstate_bcm2835_sdhost = {
 381    .name = TYPE_BCM2835_SDHOST,
 382    .version_id = 1,
 383    .minimum_version_id = 1,
 384    .fields = (VMStateField[]) {
 385        VMSTATE_UINT32(cmd, BCM2835SDHostState),
 386        VMSTATE_UINT32(cmdarg, BCM2835SDHostState),
 387        VMSTATE_UINT32(status, BCM2835SDHostState),
 388        VMSTATE_UINT32_ARRAY(rsp, BCM2835SDHostState, 4),
 389        VMSTATE_UINT32(config, BCM2835SDHostState),
 390        VMSTATE_UINT32(edm, BCM2835SDHostState),
 391        VMSTATE_UINT32(vdd, BCM2835SDHostState),
 392        VMSTATE_UINT32(hbct, BCM2835SDHostState),
 393        VMSTATE_UINT32(hblc, BCM2835SDHostState),
 394        VMSTATE_INT32(fifo_pos, BCM2835SDHostState),
 395        VMSTATE_INT32(fifo_len, BCM2835SDHostState),
 396        VMSTATE_UINT32_ARRAY(fifo, BCM2835SDHostState, BCM2835_SDHOST_FIFO_LEN),
 397        VMSTATE_UINT32(datacnt, BCM2835SDHostState),
 398        VMSTATE_END_OF_LIST()
 399    }
 400};
 401
 402static void bcm2835_sdhost_init(Object *obj)
 403{
 404    BCM2835SDHostState *s = BCM2835_SDHOST(obj);
 405
 406    qbus_create_inplace(&s->sdbus, sizeof(s->sdbus),
 407                        TYPE_BCM2835_SDHOST_BUS, DEVICE(s), "sd-bus");
 408
 409    memory_region_init_io(&s->iomem, obj, &bcm2835_sdhost_ops, s,
 410                          TYPE_BCM2835_SDHOST, 0x1000);
 411    sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem);
 412    sysbus_init_irq(SYS_BUS_DEVICE(s), &s->irq);
 413}
 414
 415static void bcm2835_sdhost_reset(DeviceState *dev)
 416{
 417    BCM2835SDHostState *s = BCM2835_SDHOST(dev);
 418
 419    s->cmd = 0;
 420    s->cmdarg = 0;
 421    s->edm = 0x0000c60f;
 422    trace_bcm2835_sdhost_edm_change("device reset", s->edm);
 423    s->config = 0;
 424    s->hbct = 0;
 425    s->hblc = 0;
 426    s->datacnt = 0;
 427    s->fifo_pos = 0;
 428    s->fifo_len = 0;
 429}
 430
 431static void bcm2835_sdhost_class_init(ObjectClass *klass, void *data)
 432{
 433    DeviceClass *dc = DEVICE_CLASS(klass);
 434
 435    dc->reset = bcm2835_sdhost_reset;
 436    dc->vmsd = &vmstate_bcm2835_sdhost;
 437}
 438
 439static TypeInfo bcm2835_sdhost_info = {
 440    .name          = TYPE_BCM2835_SDHOST,
 441    .parent        = TYPE_SYS_BUS_DEVICE,
 442    .instance_size = sizeof(BCM2835SDHostState),
 443    .class_init    = bcm2835_sdhost_class_init,
 444    .instance_init = bcm2835_sdhost_init,
 445};
 446
 447static const TypeInfo bcm2835_sdhost_bus_info = {
 448    .name = TYPE_BCM2835_SDHOST_BUS,
 449    .parent = TYPE_SD_BUS,
 450    .instance_size = sizeof(SDBus),
 451};
 452
 453static void bcm2835_sdhost_register_types(void)
 454{
 455    type_register_static(&bcm2835_sdhost_info);
 456    type_register_static(&bcm2835_sdhost_bus_info);
 457}
 458
 459type_init(bcm2835_sdhost_register_types)
 460