hw/i2c/omap_i2c.c

   1 /*
   2  * TI OMAP on-chip I2C controller.  Only "new I2C" mode supported.
   3  *
   4  * Copyright (C) 2007 Andrzej Zaborowski  <balrog@zabor.org>
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License as
   8  * published by the Free Software Foundation; either version 2 of
   9  * the License, or (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19 #include "qemu/osdep.h"
  20 #include "qemu/log.h"
  21 #include "hw/hw.h"
  22 #include "hw/i2c/i2c.h"
  23 #include "hw/arm/omap.h"
  24 #include "hw/sysbus.h"
  25 #include "qemu/error-report.h"
  26 #include "qapi/error.h"
  27
  28 #define TYPE_OMAP_I2C "omap_i2c"
  29 #define OMAP_I2C(obj) OBJECT_CHECK(OMAPI2CState, (obj), TYPE_OMAP_I2C)
  30
  31 typedef struct OMAPI2CState {
  32     SysBusDevice parent_obj;
  33
  34     MemoryRegion iomem;
  35     qemu_irq irq;
  36     qemu_irq drq[2];
  37     I2CBus *bus;
  38
  39     uint8_t revision;
  40     void *iclk;
  41     void *fclk;
  42
  43     uint8_t mask;
  44     uint16_t stat;
  45     uint16_t dma;
  46     uint16_t count;
  47     int count_cur;
  48     uint32_t fifo;
  49     int rxlen;
  50     int txlen;
  51     uint16_t control;
  52     uint16_t addr[2];
  53     uint8_t divider;
  54     uint8_t times[2];
  55     uint16_t test;
  56 } OMAPI2CState;
  57
  58 #define OMAP2_INTR_REV  0x34
  59 #define OMAP2_GC_REV    0x34
  60
  61 static void omap_i2c_interrupts_update(OMAPI2CState *s)
  62 {
  63     qemu_set_irq(s->irq, s->stat & s->mask);
  64     if ((s->dma >> 15) & 1)                                     /* RDMA_EN */
  65         qemu_set_irq(s->drq[0], (s->stat >> 3) & 1);            /* RRDY */
  66     if ((s->dma >> 7) & 1)                                      /* XDMA_EN */
  67         qemu_set_irq(s->drq[1], (s->stat >> 4) & 1);            /* XRDY */
  68 }
  69
  70 static void omap_i2c_fifo_run(OMAPI2CState *s)
  71 {
  72     int ack = 1;
  73
  74     if (!i2c_bus_busy(s->bus))
  75         return;
  76
  77     if ((s->control >> 2) & 1) {                                /* RM */
  78         if ((s->control >> 1) & 1) {                            /* STP */
  79             i2c_end_transfer(s->bus);
  80             s->control &= ~(1 << 1);                            /* STP */
  81             s->count_cur = s->count;
  82             s->txlen = 0;
  83         } else if ((s->control >> 9) & 1) {                     /* TRX */
  84             while (ack && s->txlen)
  85                 ack = (i2c_send(s->bus,
  86                                         (s->fifo >> ((-- s->txlen) << 3)) &
  87                                         0xff) >= 0);
  88             s->stat |= 1 << 4;                                  /* XRDY */
  89         } else {
  90             while (s->rxlen < 4)
  91                 s->fifo |= i2c_recv(s->bus) << ((s->rxlen ++) << 3);
  92             s->stat |= 1 << 3;                                  /* RRDY */
  93         }
  94     } else {
  95         if ((s->control >> 9) & 1) {                            /* TRX */
  96             while (ack && s->count_cur && s->txlen) {
  97                 ack = (i2c_send(s->bus,
  98                                         (s->fifo >> ((-- s->txlen) << 3)) &
  99                                         0xff) >= 0);
 100                 s->count_cur --;
 101             }
 102             if (ack && s->count_cur)
 103                 s->stat |= 1 << 4;                              /* XRDY */
 104             else
 105                 s->stat &= ~(1 << 4);                           /* XRDY */
 106             if (!s->count_cur) {
 107                 s->stat |= 1 << 2;                              /* ARDY */
 108                 s->control &= ~(1 << 10);                       /* MST */
 109             }
 110         } else {
 111             while (s->count_cur && s->rxlen < 4) {
 112                 s->fifo |= i2c_recv(s->bus) << ((s->rxlen ++) << 3);
 113                 s->count_cur --;
 114             }
 115             if (s->rxlen)
 116                 s->stat |= 1 << 3;                              /* RRDY */
 117             else
 118                 s->stat &= ~(1 << 3);                           /* RRDY */
 119         }
 120         if (!s->count_cur) {
 121             if ((s->control >> 1) & 1) {                        /* STP */
 122                 i2c_end_transfer(s->bus);
 123                 s->control &= ~(1 << 1);                        /* STP */
 124                 s->count_cur = s->count;
 125                 s->txlen = 0;
 126             } else {
 127                 s->stat |= 1 << 2;                              /* ARDY */
 128                 s->control &= ~(1 << 10);                       /* MST */
 129             }
 130         }
 131     }
 132
 133     s->stat |= (!ack) << 1;                                     /* NACK */
 134     if (!ack)
 135         s->control &= ~(1 << 1);                                /* STP */
 136 }
 137
 138 static void omap_i2c_reset(DeviceState *dev)
 139 {
 140     OMAPI2CState *s = OMAP_I2C(dev);
 141
 142     s->mask = 0;
 143     s->stat = 0;
 144     s->dma = 0;
 145     s->count = 0;
 146     s->count_cur = 0;
 147     s->fifo = 0;
 148     s->rxlen = 0;
 149     s->txlen = 0;
 150     s->control = 0;
 151     s->addr[0] = 0;
 152     s->addr[1] = 0;
 153     s->divider = 0;
 154     s->times[0] = 0;
 155     s->times[1] = 0;
 156     s->test = 0;
 157 }
 158
 159 static uint32_t omap_i2c_read(void *opaque, hwaddr addr)
 160 {
 161     OMAPI2CState *s = opaque;
 162     int offset = addr & OMAP_MPUI_REG_MASK;
 163     uint16_t ret;
 164
 165     switch (offset) {
 166     case 0x00:  /* I2C_REV */
 167         return s->revision;                                     /* REV */
 168
 169     case 0x04:  /* I2C_IE */
 170         return s->mask;
 171
 172     case 0x08:  /* I2C_STAT */
 173         return s->stat | (i2c_bus_busy(s->bus) << 12);
 174
 175     case 0x0c:  /* I2C_IV */
 176         if (s->revision >= OMAP2_INTR_REV)
 177             break;
 178         ret = ctz32(s->stat & s->mask);
 179         if (ret != 32) {
 180             s->stat ^= 1 << ret;
 181             ret++;
 182         } else {
 183             ret = 0;
 184         }
 185         omap_i2c_interrupts_update(s);
 186         return ret;
 187
 188     case 0x10:  /* I2C_SYSS */
 189         return (s->control >> 15) & 1;                          /* I2C_EN */
 190
 191     case 0x14:  /* I2C_BUF */
 192         return s->dma;
 193
 194     case 0x18:  /* I2C_CNT */
 195         return s->count_cur;                                    /* DCOUNT */
 196
 197     case 0x1c:  /* I2C_DATA */
 198         ret = 0;
 199         if (s->control & (1 << 14)) {                           /* BE */
 200             ret |= ((s->fifo >> 0) & 0xff) << 8;
 201             ret |= ((s->fifo >> 8) & 0xff) << 0;
 202         } else {
 203             ret |= ((s->fifo >> 8) & 0xff) << 8;
 204             ret |= ((s->fifo >> 0) & 0xff) << 0;
 205         }
 206         if (s->rxlen == 1) {
 207             s->stat |= 1 << 15;                                 /* SBD */
 208             s->rxlen = 0;
 209         } else if (s->rxlen > 1) {
 210             if (s->rxlen > 2)
 211                 s->fifo >>= 16;
 212             s->rxlen -= 2;
 213         } else {
 214             /* XXX: remote access (qualifier) error - what's that?  */
 215         }
 216         if (!s->rxlen) {
 217             s->stat &= ~(1 << 3);                               /* RRDY */
 218             if (((s->control >> 10) & 1) &&                     /* MST */
 219                             ((~s->control >> 9) & 1)) {         /* TRX */
 220                 s->stat |= 1 << 2;                              /* ARDY */
 221                 s->control &= ~(1 << 10);                       /* MST */
 222             }
 223         }
 224         s->stat &= ~(1 << 11);                                  /* ROVR */
 225         omap_i2c_fifo_run(s);
 226         omap_i2c_interrupts_update(s);
 227         return ret;
 228
 229     case 0x20:  /* I2C_SYSC */
 230         return 0;
 231
 232     case 0x24:  /* I2C_CON */
 233         return s->control;
 234
 235     case 0x28:  /* I2C_OA */
 236         return s->addr[0];
 237
 238     case 0x2c:  /* I2C_SA */
 239         return s->addr[1];
 240
 241     case 0x30:  /* I2C_PSC */
 242         return s->divider;
 243
 244     case 0x34:  /* I2C_SCLL */
 245         return s->times[0];
 246
 247     case 0x38:  /* I2C_SCLH */
 248         return s->times[1];
 249
 250     case 0x3c:  /* I2C_SYSTEST */
 251         if (s->test & (1 << 15)) {                              /* ST_EN */
 252             s->test ^= 0xa;
 253             return s->test;
 254         } else
 255             return s->test & ~0x300f;
 256     }
 257
 258     OMAP_BAD_REG(addr);
 259     return 0;
 260 }
 261
 262 static void omap_i2c_write(void *opaque, hwaddr addr,
 263                 uint32_t value)
 264 {
 265     OMAPI2CState *s = opaque;
 266     int offset = addr & OMAP_MPUI_REG_MASK;
 267     int nack;
 268
 269     switch (offset) {
 270     case 0x00:  /* I2C_REV */
 271     case 0x0c:  /* I2C_IV */
 272     case 0x10:  /* I2C_SYSS */
 273         OMAP_RO_REG(addr);
 274         return;
 275
 276     case 0x04:  /* I2C_IE */
 277         s->mask = value & (s->revision < OMAP2_GC_REV ? 0x1f : 0x3f);
 278         break;
 279
 280     case 0x08:  /* I2C_STAT */
 281         if (s->revision < OMAP2_INTR_REV) {
 282             OMAP_RO_REG(addr);
 283             return;
 284         }
 285
 286         /* RRDY and XRDY are reset by hardware. (in all versions???) */
 287         s->stat &= ~(value & 0x27);
 288         omap_i2c_interrupts_update(s);
 289         break;
 290
 291     case 0x14:  /* I2C_BUF */
 292         s->dma = value & 0x8080;
 293         if (value & (1 << 15))                                  /* RDMA_EN */
 294             s->mask &= ~(1 << 3);                               /* RRDY_IE */
 295         if (value & (1 << 7))                                   /* XDMA_EN */
 296             s->mask &= ~(1 << 4);                               /* XRDY_IE */
 297         break;
 298
 299     case 0x18:  /* I2C_CNT */
 300         s->count = value;                                       /* DCOUNT */
 301         break;
 302
 303     case 0x1c:  /* I2C_DATA */
 304         if (s->txlen > 2) {
 305             /* XXX: remote access (qualifier) error - what's that?  */
 306             break;
 307         }
 308         s->fifo <<= 16;
 309         s->txlen += 2;
 310         if (s->control & (1 << 14)) {                           /* BE */
 311             s->fifo |= ((value >> 8) & 0xff) << 8;
 312             s->fifo |= ((value >> 0) & 0xff) << 0;
 313         } else {
 314             s->fifo |= ((value >> 0) & 0xff) << 8;
 315             s->fifo |= ((value >> 8) & 0xff) << 0;
 316         }
 317         s->stat &= ~(1 << 10);                                  /* XUDF */
 318         if (s->txlen > 2)
 319             s->stat &= ~(1 << 4);                               /* XRDY */
 320         omap_i2c_fifo_run(s);
 321         omap_i2c_interrupts_update(s);
 322         break;
 323
 324     case 0x20:  /* I2C_SYSC */
 325         if (s->revision < OMAP2_INTR_REV) {
 326             OMAP_BAD_REG(addr);
 327             return;
 328         }
 329
 330         if (value & 2) {
 331             omap_i2c_reset(DEVICE(s));
 332         }
 333         break;
 334
 335     case 0x24:  /* I2C_CON */
 336         s->control = value & 0xcf87;
 337         if (~value & (1 << 15)) {                               /* I2C_EN */
 338             if (s->revision < OMAP2_INTR_REV) {
 339                 omap_i2c_reset(DEVICE(s));
 340             }
 341             break;
 342         }
 343         if ((value & (1 << 15)) && !(value & (1 << 10))) {    /* MST */
 344             qemu_log_mask(LOG_UNIMP, "%s: I^2C slave mode not supported\n",
 345                           __func__);
 346             break;
 347         }
 348         if ((value & (1 << 15)) && value & (1 << 8)) {        /* XA */
 349             qemu_log_mask(LOG_UNIMP,
 350                           "%s: 10-bit addressing mode not supported\n",
 351                           __func__);
 352             break;
 353         }
 354         if ((value & (1 << 15)) && value & (1 << 0)) {          /* STT */
 355             nack = !!i2c_start_transfer(s->bus, s->addr[1],     /* SA */
 356                             (~value >> 9) & 1);                 /* TRX */
 357             s->stat |= nack << 1;                               /* NACK */
 358             s->control &= ~(1 << 0);                            /* STT */
 359             s->fifo = 0;
 360             if (nack)
 361                 s->control &= ~(1 << 1);                        /* STP */
 362             else {
 363                 s->count_cur = s->count;
 364                 omap_i2c_fifo_run(s);
 365             }
 366             omap_i2c_interrupts_update(s);
 367         }
 368         break;
 369
 370     case 0x28:  /* I2C_OA */
 371         s->addr[0] = value & 0x3ff;
 372         break;
 373
 374     case 0x2c:  /* I2C_SA */
 375         s->addr[1] = value & 0x3ff;
 376         break;
 377
 378     case 0x30:  /* I2C_PSC */
 379         s->divider = value;
 380         break;
 381
 382     case 0x34:  /* I2C_SCLL */
 383         s->times[0] = value;
 384         break;
 385
 386     case 0x38:  /* I2C_SCLH */
 387         s->times[1] = value;
 388         break;
 389
 390     case 0x3c:  /* I2C_SYSTEST */
 391         s->test = value & 0xf80f;
 392         if (value & (1 << 11))                                  /* SBB */
 393             if (s->revision >= OMAP2_INTR_REV) {
 394                 s->stat |= 0x3f;
 395                 omap_i2c_interrupts_update(s);
 396             }
 397         if (value & (1 << 15)) {                    /* ST_EN */
 398             qemu_log_mask(LOG_UNIMP,
 399                           "%s: System Test not supported\n", __func__);
 400         }
 401         break;
 402
 403     default:
 404         OMAP_BAD_REG(addr);
 405         return;
 406     }
 407 }
 408
 409 static void omap_i2c_writeb(void *opaque, hwaddr addr,
 410                 uint32_t value)
 411 {
 412     OMAPI2CState *s = opaque;
 413     int offset = addr & OMAP_MPUI_REG_MASK;
 414
 415     switch (offset) {
 416     case 0x1c:  /* I2C_DATA */
 417         if (s->txlen > 2) {
 418             /* XXX: remote access (qualifier) error - what's that?  */
 419             break;
 420         }
 421         s->fifo <<= 8;
 422         s->txlen += 1;
 423         s->fifo |= value & 0xff;
 424         s->stat &= ~(1 << 10);                                  /* XUDF */
 425         if (s->txlen > 2)
 426             s->stat &= ~(1 << 4);                               /* XRDY */
 427         omap_i2c_fifo_run(s);
 428         omap_i2c_interrupts_update(s);
 429         break;
 430
 431     default:
 432         OMAP_BAD_REG(addr);
 433         return;
 434     }
 435 }
 436
 437 static uint64_t omap_i2c_readfn(void *opaque, hwaddr addr,
 438                                 unsigned size)
 439 {
 440     switch (size) {
 441     case 2:
 442         return omap_i2c_read(opaque, addr);
 443     default:
 444         return omap_badwidth_read16(opaque, addr);
 445     }
 446 }
 447
 448 static void omap_i2c_writefn(void *opaque, hwaddr addr,
 449                              uint64_t value, unsigned size)
 450 {
 451     switch (size) {
 452     case 1:
 453         /* Only the last fifo write can be 8 bit. */
 454         omap_i2c_writeb(opaque, addr, value);
 455         break;
 456     case 2:
 457         omap_i2c_write(opaque, addr, value);
 458         break;
 459     default:
 460         omap_badwidth_write16(opaque, addr, value);
 461         break;
 462     }
 463 }
 464
 465 static const MemoryRegionOps omap_i2c_ops = {
 466     .read = omap_i2c_readfn,
 467     .write = omap_i2c_writefn,
 468     .valid.min_access_size = 1,
 469     .valid.max_access_size = 4,
 470     .endianness = DEVICE_NATIVE_ENDIAN,
 471 };
 472
 473 static void omap_i2c_init(Object *obj)
 474 {
 475     DeviceState *dev = DEVICE(obj);
 476     OMAPI2CState *s = OMAP_I2C(obj);
 477     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
 478
 479     sysbus_init_irq(sbd, &s->irq);
 480     sysbus_init_irq(sbd, &s->drq[0]);
 481     sysbus_init_irq(sbd, &s->drq[1]);
 482     sysbus_init_mmio(sbd, &s->iomem);
 483     s->bus = i2c_init_bus(dev, NULL);
 484 }
 485
 486 static void omap_i2c_realize(DeviceState *dev, Error **errp)
 487 {
 488     OMAPI2CState *s = OMAP_I2C(dev);
 489
 490     memory_region_init_io(&s->iomem, OBJECT(dev), &omap_i2c_ops, s, "omap.i2c",
 491                           (s->revision < OMAP2_INTR_REV) ? 0x800 : 0x1000);
 492
 493     if (!s->fclk) {
 494         error_setg(errp, "omap_i2c: fclk not connected");
 495         return;
 496     }
 497     if (s->revision >= OMAP2_INTR_REV && !s->iclk) {
 498         /* Note that OMAP1 doesn't have a separate interface clock */
 499         error_setg(errp, "omap_i2c: iclk not connected");
 500         return;
 501     }
 502 }
 503
 504 static Property omap_i2c_properties[] = {
 505     DEFINE_PROP_UINT8("revision", OMAPI2CState, revision, 0),
 506     DEFINE_PROP_PTR("iclk", OMAPI2CState, iclk),
 507     DEFINE_PROP_PTR("fclk", OMAPI2CState, fclk),
 508     DEFINE_PROP_END_OF_LIST(),
 509 };
 510
 511 static void omap_i2c_class_init(ObjectClass *klass, void *data)
 512 {
 513     DeviceClass *dc = DEVICE_CLASS(klass);
 514
 515     dc->props = omap_i2c_properties;
 516     dc->reset = omap_i2c_reset;
 517     /* Reason: pointer properties "iclk", "fclk" */
 518     dc->user_creatable = false;
 519     dc->realize = omap_i2c_realize;
 520 }
 521
 522 static const TypeInfo omap_i2c_info = {
 523     .name = TYPE_OMAP_I2C,
 524     .parent = TYPE_SYS_BUS_DEVICE,
 525     .instance_size = sizeof(OMAPI2CState),
 526     .instance_init = omap_i2c_init,
 527     .class_init = omap_i2c_class_init,
 528 };
 529
 530 static void omap_i2c_register_types(void)
 531 {
 532     type_register_static(&omap_i2c_info);
 533 }
 534
 535 I2CBus *omap_i2c_bus(DeviceState *omap_i2c)
 536 {
 537     OMAPI2CState *s = OMAP_I2C(omap_i2c);
 538     return s->bus;
 539 }
 540
 541 type_init(omap_i2c_register_types)