hw/pl181.c

   1 /*
   2  * Arm PrimeCell PL181 MultiMedia Card Interface
   3  *
   4  * Copyright (c) 2007 CodeSourcery.
   5  * Written by Paul Brook
   6  *
   7  * This code is licenced under the GPL.
   8  */
   9
  10 #include "hw.h"
  11 #include "primecell.h"
  12 #include "sd.h"
  13
  14 //#define DEBUG_PL181 1
  15
  16 #ifdef DEBUG_PL181
  17 #define DPRINTF(fmt, args...) \
  18 do { printf("pl181: " fmt , ##args); } while (0)
  19 #else
  20 #define DPRINTF(fmt, args...) do {} while(0)
  21 #endif
  22
  23 #define PL181_FIFO_LEN 16
  24
  25 typedef struct {
  26     SDState *card;
  27     uint32_t base;
  28     uint32_t clock;
  29     uint32_t power;
  30     uint32_t cmdarg;
  31     uint32_t cmd;
  32     uint32_t datatimer;
  33     uint32_t datalength;
  34     uint32_t respcmd;
  35     uint32_t response[4];
  36     uint32_t datactrl;
  37     uint32_t datacnt;
  38     uint32_t status;
  39     uint32_t mask[2];
  40     int fifo_pos;
  41     int fifo_len;
  42     /* The linux 2.6.21 driver is buggy, and misbehaves if new data arrives
  43        while it is reading the FIFO.  We hack around this be defering
  44        subsequent transfers until after the driver polls the status word.
  45        http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=4446/1
  46      */
  47     int linux_hack;
  48     uint32_t fifo[PL181_FIFO_LEN];
  49     qemu_irq irq[2];
  50 } pl181_state;
  51
  52 #define PL181_CMD_INDEX     0x3f
  53 #define PL181_CMD_RESPONSE  (1 << 6)
  54 #define PL181_CMD_LONGRESP  (1 << 7)
  55 #define PL181_CMD_INTERRUPT (1 << 8)
  56 #define PL181_CMD_PENDING   (1 << 9)
  57 #define PL181_CMD_ENABLE    (1 << 10)
  58
  59 #define PL181_DATA_ENABLE             (1 << 0)
  60 #define PL181_DATA_DIRECTION          (1 << 1)
  61 #define PL181_DATA_MODE               (1 << 2)
  62 #define PL181_DATA_DMAENABLE          (1 << 3)
  63
  64 #define PL181_STATUS_CMDCRCFAIL       (1 << 0)
  65 #define PL181_STATUS_DATACRCFAIL      (1 << 1)
  66 #define PL181_STATUS_CMDTIMEOUT       (1 << 2)
  67 #define PL181_STATUS_DATATIMEOUT      (1 << 3)
  68 #define PL181_STATUS_TXUNDERRUN       (1 << 4)
  69 #define PL181_STATUS_RXOVERRUN        (1 << 5)
  70 #define PL181_STATUS_CMDRESPEND       (1 << 6)
  71 #define PL181_STATUS_CMDSENT          (1 << 7)
  72 #define PL181_STATUS_DATAEND          (1 << 8)
  73 #define PL181_STATUS_DATABLOCKEND     (1 << 10)
  74 #define PL181_STATUS_CMDACTIVE        (1 << 11)
  75 #define PL181_STATUS_TXACTIVE         (1 << 12)
  76 #define PL181_STATUS_RXACTIVE         (1 << 13)
  77 #define PL181_STATUS_TXFIFOHALFEMPTY  (1 << 14)
  78 #define PL181_STATUS_RXFIFOHALFFULL   (1 << 15)
  79 #define PL181_STATUS_TXFIFOFULL       (1 << 16)
  80 #define PL181_STATUS_RXFIFOFULL       (1 << 17)
  81 #define PL181_STATUS_TXFIFOEMPTY      (1 << 18)
  82 #define PL181_STATUS_RXFIFOEMPTY      (1 << 19)
  83 #define PL181_STATUS_TXDATAAVLBL      (1 << 20)
  84 #define PL181_STATUS_RXDATAAVLBL      (1 << 21)
  85
  86 #define PL181_STATUS_TX_FIFO (PL181_STATUS_TXACTIVE \
  87                              |PL181_STATUS_TXFIFOHALFEMPTY \
  88                              |PL181_STATUS_TXFIFOFULL \
  89                              |PL181_STATUS_TXFIFOEMPTY \
  90                              |PL181_STATUS_TXDATAAVLBL)
  91 #define PL181_STATUS_RX_FIFO (PL181_STATUS_RXACTIVE \
  92                              |PL181_STATUS_RXFIFOHALFFULL \
  93                              |PL181_STATUS_RXFIFOFULL \
  94                              |PL181_STATUS_RXFIFOEMPTY \
  95                              |PL181_STATUS_RXDATAAVLBL)
  96
  97 static const unsigned char pl181_id[] =
  98 { 0x81, 0x11, 0x04, 0x00, 0x0d, 0xf0, 0x05, 0xb1 };
  99
 100 static void pl181_update(pl181_state *s)
 101 {
 102     int i;
 103     for (i = 0; i < 2; i++) {
 104         qemu_set_irq(s->irq[i], (s->status & s->mask[i]) != 0);
 105     }
 106 }
 107
 108 static void pl181_fifo_push(pl181_state *s, uint32_t value)
 109 {
 110     int n;
 111
 112     if (s->fifo_len == PL181_FIFO_LEN) {
 113         fprintf(stderr, "pl181: FIFO overflow\n");
 114         return;
 115     }
 116     n = (s->fifo_pos + s->fifo_len) & (PL181_FIFO_LEN - 1);
 117     s->fifo_len++;
 118     s->fifo[n] = value;
 119     DPRINTF("FIFO push %08x\n", (int)value);
 120 }
 121
 122 static uint32_t pl181_fifo_pop(pl181_state *s)
 123 {
 124     uint32_t value;
 125
 126     if (s->fifo_len == 0) {
 127         fprintf(stderr, "pl181: FIFO underflow\n");
 128         return 0;
 129     }
 130     value = s->fifo[s->fifo_pos];
 131     s->fifo_len--;
 132     s->fifo_pos = (s->fifo_pos + 1) & (PL181_FIFO_LEN - 1);
 133     DPRINTF("FIFO pop %08x\n", (int)value);
 134     return value;
 135 }
 136
 137 static void pl181_send_command(pl181_state *s)
 138 {
 139     struct sd_request_s request;
 140     uint8_t response[16];
 141     int rlen;
 142
 143     request.cmd = s->cmd & PL181_CMD_INDEX;
 144     request.arg = s->cmdarg;
 145     DPRINTF("Command %d %08x\n", request.cmd, request.arg);
 146     rlen = sd_do_command(s->card, &request, response);
 147     if (rlen < 0)
 148         goto error;
 149     if (s->cmd & PL181_CMD_RESPONSE) {
 150 #define RWORD(n) ((response[n] << 24) | (response[n + 1] << 16) \
 151                   | (response[n + 2] << 8) | response[n + 3])
 152         if (rlen == 0 || (rlen == 4 && (s->cmd & PL181_CMD_LONGRESP)))
 153             goto error;
 154         if (rlen != 4 && rlen != 16)
 155             goto error;
 156         s->response[0] = RWORD(0);
 157         if (rlen == 4) {
 158             s->response[1] = s->response[2] = s->response[3] = 0;
 159         } else {
 160             s->response[1] = RWORD(4);
 161             s->response[2] = RWORD(8);
 162             s->response[3] = RWORD(12) & ~1;
 163         }
 164         DPRINTF("Response received\n");
 165         s->status |= PL181_STATUS_CMDRESPEND;
 166 #undef RWORD
 167     } else {
 168         DPRINTF("Command sent\n");
 169         s->status |= PL181_STATUS_CMDSENT;
 170     }
 171     return;
 172
 173 error:
 174     DPRINTF("Timeout\n");
 175     s->status |= PL181_STATUS_CMDTIMEOUT;
 176 }
 177
 178 /* Transfer data between the card and the FIFO.  This is complicated by
 179    the FIFO holding 32-bit words and the card taking data in single byte
 180    chunks.  FIFO bytes are transferred in little-endian order.  */
 181
 182 static void pl181_fifo_run(pl181_state *s)
 183 {
 184     uint32_t bits;
 185     uint32_t value;
 186     int n;
 187     int limit;
 188     int is_read;
 189
 190     is_read = (s->datactrl & PL181_DATA_DIRECTION) != 0;
 191     if (s->datacnt != 0 && (!is_read || sd_data_ready(s->card))
 192             && !s->linux_hack) {
 193         limit = is_read ? PL181_FIFO_LEN : 0;
 194         n = 0;
 195         value = 0;
 196         while (s->datacnt && s->fifo_len != limit) {
 197             if (is_read) {
 198                 value |= (uint32_t)sd_read_data(s->card) << (n * 8);
 199                 n++;
 200                 if (n == 4) {
 201                     pl181_fifo_push(s, value);
 202                     value = 0;
 203                     n = 0;
 204                 }
 205             } else {
 206                 if (n == 0) {
 207                     value = pl181_fifo_pop(s);
 208                     n = 4;
 209                 }
 210                 sd_write_data(s->card, value & 0xff);
 211                 value >>= 8;
 212                 n--;
 213             }
 214             s->datacnt--;
 215         }
 216         if (n && is_read) {
 217             pl181_fifo_push(s, value);
 218         }
 219     }
 220     s->status &= ~(PL181_STATUS_RX_FIFO | PL181_STATUS_TX_FIFO);
 221     if (s->datacnt == 0) {
 222         s->status |= PL181_STATUS_DATAEND;
 223         /* HACK: */
 224         s->status |= PL181_STATUS_DATABLOCKEND;
 225         DPRINTF("Transfer Complete\n");
 226     }
 227     if (s->datacnt == 0 && s->fifo_len == 0) {
 228         s->datactrl &= ~PL181_DATA_ENABLE;
 229         DPRINTF("Data engine idle\n");
 230     } else {
 231         /* Update FIFO bits.  */
 232         bits = PL181_STATUS_TXACTIVE | PL181_STATUS_RXACTIVE;
 233         if (s->fifo_len == 0) {
 234             bits |= PL181_STATUS_TXFIFOEMPTY;
 235             bits |= PL181_STATUS_RXFIFOEMPTY;
 236         } else {
 237             bits |= PL181_STATUS_TXDATAAVLBL;
 238             bits |= PL181_STATUS_RXDATAAVLBL;
 239         }
 240         if (s->fifo_len == 16) {
 241             bits |= PL181_STATUS_TXFIFOFULL;
 242             bits |= PL181_STATUS_RXFIFOFULL;
 243         }
 244         if (s->fifo_len <= 8) {
 245             bits |= PL181_STATUS_TXFIFOHALFEMPTY;
 246         }
 247         if (s->fifo_len >= 8) {
 248             bits |= PL181_STATUS_RXFIFOHALFFULL;
 249         }
 250         if (s->datactrl & PL181_DATA_DIRECTION) {
 251             bits &= PL181_STATUS_RX_FIFO;
 252         } else {
 253             bits &= PL181_STATUS_TX_FIFO;
 254         }
 255         s->status |= bits;
 256     }
 257 }
 258
 259 static uint32_t pl181_read(void *opaque, target_phys_addr_t offset)
 260 {
 261     pl181_state *s = (pl181_state *)opaque;
 262     uint32_t tmp;
 263
 264     offset -= s->base;
 265     if (offset >= 0xfe0 && offset < 0x1000) {
 266         return pl181_id[(offset - 0xfe0) >> 2];
 267     }
 268     switch (offset) {
 269     case 0x00: /* Power */
 270         return s->power;
 271     case 0x04: /* Clock */
 272         return s->clock;
 273     case 0x08: /* Argument */
 274         return s->cmdarg;
 275     case 0x0c: /* Command */
 276         return s->cmd;
 277     case 0x10: /* RespCmd */
 278         return s->respcmd;
 279     case 0x14: /* Response0 */
 280         return s->response[0];
 281     case 0x18: /* Response1 */
 282         return s->response[1];
 283     case 0x1c: /* Response2 */
 284         return s->response[2];
 285     case 0x20: /* Response3 */
 286         return s->response[3];
 287     case 0x24: /* DataTimer */
 288         return s->datatimer;
 289     case 0x28: /* DataLength */
 290         return s->datalength;
 291     case 0x2c: /* DataCtrl */
 292         return s->datactrl;
 293     case 0x30: /* DataCnt */
 294         return s->datacnt;
 295     case 0x34: /* Status */
 296         tmp = s->status;
 297         if (s->linux_hack) {
 298             s->linux_hack = 0;
 299             pl181_fifo_run(s);
 300             pl181_update(s);
 301         }
 302         return tmp;
 303     case 0x3c: /* Mask0 */
 304         return s->mask[0];
 305     case 0x40: /* Mask1 */
 306         return s->mask[1];
 307     case 0x48: /* FifoCnt */
 308         /* The documentation is somewhat vague about exactly what FifoCnt
 309            does.  On real hardware it appears to be when decrememnted
 310            when a word is transfered between the FIFO and the serial
 311            data engine.  DataCnt is decremented after each byte is
 312            transfered between the serial engine and the card.
 313            We don't emulate this level of detail, so both can be the same.  */
 314         tmp = (s->datacnt + 3) >> 2;
 315         if (s->linux_hack) {
 316             s->linux_hack = 0;
 317             pl181_fifo_run(s);
 318             pl181_update(s);
 319         }
 320         return tmp;
 321     case 0x80: case 0x84: case 0x88: case 0x8c: /* FifoData */
 322     case 0x90: case 0x94: case 0x98: case 0x9c:
 323     case 0xa0: case 0xa4: case 0xa8: case 0xac:
 324     case 0xb0: case 0xb4: case 0xb8: case 0xbc:
 325         if (s->fifo_len == 0) {
 326             fprintf(stderr, "pl181: Unexpected FIFO read\n");
 327             return 0;
 328         } else {
 329             uint32_t value;
 330             value = pl181_fifo_pop(s);
 331             s->linux_hack = 1;
 332             pl181_fifo_run(s);
 333             pl181_update(s);
 334             return value;
 335         }
 336     default:
 337         cpu_abort (cpu_single_env, "pl181_read: Bad offset %x\n", (int)offset);
 338         return 0;
 339     }
 340 }
 341
 342 static void pl181_write(void *opaque, target_phys_addr_t offset,
 343                           uint32_t value)
 344 {
 345     pl181_state *s = (pl181_state *)opaque;
 346
 347     offset -= s->base;
 348     switch (offset) {
 349     case 0x00: /* Power */
 350         s->power = value & 0xff;
 351         break;
 352     case 0x04: /* Clock */
 353         s->clock = value & 0xff;
 354         break;
 355     case 0x08: /* Argument */
 356         s->cmdarg = value;
 357         break;
 358     case 0x0c: /* Command */
 359         s->cmd = value;
 360         if (s->cmd & PL181_CMD_ENABLE) {
 361             if (s->cmd & PL181_CMD_INTERRUPT) {
 362                 fprintf(stderr, "pl181: Interrupt mode not implemented\n");
 363                 abort();
 364             } if (s->cmd & PL181_CMD_PENDING) {
 365                 fprintf(stderr, "pl181: Pending commands not implemented\n");
 366                 abort();
 367             } else {
 368                 pl181_send_command(s);
 369                 pl181_fifo_run(s);
 370             }
 371             /* The command has completed one way or the other.  */
 372             s->cmd &= ~PL181_CMD_ENABLE;
 373         }
 374         break;
 375     case 0x24: /* DataTimer */
 376         s->datatimer = value;
 377         break;
 378     case 0x28: /* DataLength */
 379         s->datalength = value & 0xffff;
 380         break;
 381     case 0x2c: /* DataCtrl */
 382         s->datactrl = value & 0xff;
 383         if (value & PL181_DATA_ENABLE) {
 384             s->datacnt = s->datalength;
 385             pl181_fifo_run(s);
 386         }
 387         break;
 388     case 0x38: /* Clear */
 389         s->status &= ~(value & 0x7ff);
 390         break;
 391     case 0x3c: /* Mask0 */
 392         s->mask[0] = value;
 393         break;
 394     case 0x40: /* Mask1 */
 395         s->mask[1] = value;
 396         break;
 397     case 0x80: case 0x84: case 0x88: case 0x8c: /* FifoData */
 398     case 0x90: case 0x94: case 0x98: case 0x9c:
 399     case 0xa0: case 0xa4: case 0xa8: case 0xac:
 400     case 0xb0: case 0xb4: case 0xb8: case 0xbc:
 401         if (s->datacnt == 0) {
 402             fprintf(stderr, "pl181: Unexpected FIFO write\n");
 403         } else {
 404             pl181_fifo_push(s, value);
 405             pl181_fifo_run(s);
 406         }
 407         break;
 408     default:
 409         cpu_abort (cpu_single_env, "pl181_write: Bad offset %x\n", (int)offset);
 410     }
 411     pl181_update(s);
 412 }
 413
 414 static CPUReadMemoryFunc *pl181_readfn[] = {
 415    pl181_read,
 416    pl181_read,
 417    pl181_read
 418 };
 419
 420 static CPUWriteMemoryFunc *pl181_writefn[] = {
 421    pl181_write,
 422    pl181_write,
 423    pl181_write
 424 };
 425
 426 static void pl181_reset(void *opaque)
 427 {
 428     pl181_state *s = (pl181_state *)opaque;
 429
 430     s->power = 0;
 431     s->cmdarg = 0;
 432     s->cmd = 0;
 433     s->datatimer = 0;
 434     s->datalength = 0;
 435     s->respcmd = 0;
 436     s->response[0] = 0;
 437     s->response[1] = 0;
 438     s->response[2] = 0;
 439     s->response[3] = 0;
 440     s->datatimer = 0;
 441     s->datalength = 0;
 442     s->datactrl = 0;
 443     s->datacnt = 0;
 444     s->status = 0;
 445     s->linux_hack = 0;
 446     s->mask[0] = 0;
 447     s->mask[1] = 0;
 448 }
 449
 450 void pl181_init(uint32_t base, BlockDriverState *bd,
 451                 qemu_irq irq0, qemu_irq irq1)
 452 {
 453     int iomemtype;
 454     pl181_state *s;
 455
 456     s = (pl181_state *)qemu_mallocz(sizeof(pl181_state));
 457     iomemtype = cpu_register_io_memory(0, pl181_readfn,
 458                                        pl181_writefn, s);
 459     cpu_register_physical_memory(base, 0x00001000, iomemtype);
 460     s->base = base;
 461     s->card = sd_init(bd, 0);
 462     s->irq[0] = irq0;
 463     s->irq[1] = irq1;
 464     qemu_register_reset(pl181_reset, s);
 465     pl181_reset(s);
 466     /* ??? Save/restore.  */
 467 }