hw/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
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  19  * MA 02111-1307 USA
  20  */
  21 #include "hw.h"
  22 #include "i2c.h"
  23 #include "omap.h"
  24
  25 struct omap_i2c_s {
  26     target_phys_addr_t base;
  27     qemu_irq irq;
  28     qemu_irq drq[2];
  29     i2c_slave slave;
  30     i2c_bus *bus;
  31
  32     uint8_t revision;
  33     uint8_t mask;
  34     uint16_t stat;
  35     uint16_t dma;
  36     uint16_t count;
  37     int count_cur;
  38     uint32_t fifo;
  39     int rxlen;
  40     int txlen;
  41     uint16_t control;
  42     uint16_t addr[2];
  43     uint8_t divider;
  44     uint8_t times[2];
  45     uint16_t test;
  46 };
  47
  48 #define OMAP2_INTR_REV  0x34
  49 #define OMAP2_GC_REV    0x34
  50
  51 static void omap_i2c_interrupts_update(struct omap_i2c_s *s)
  52 {
  53     qemu_set_irq(s->irq, s->stat & s->mask);
  54     if ((s->dma >> 15) & 1)                                     /* RDMA_EN */
  55         qemu_set_irq(s->drq[0], (s->stat >> 3) & 1);            /* RRDY */
  56     if ((s->dma >> 7) & 1)                                      /* XDMA_EN */
  57         qemu_set_irq(s->drq[1], (s->stat >> 4) & 1);            /* XRDY */
  58 }
  59
  60 /* These are only stubs now.  */
  61 static void omap_i2c_event(i2c_slave *i2c, enum i2c_event event)
  62 {
  63     struct omap_i2c_s *s = (struct omap_i2c_s *) i2c;
  64
  65     if ((~s->control >> 15) & 1)                                /* I2C_EN */
  66         return;
  67
  68     switch (event) {
  69     case I2C_START_SEND:
  70     case I2C_START_RECV:
  71         s->stat |= 1 << 9;                                      /* AAS */
  72         break;
  73     case I2C_FINISH:
  74         s->stat |= 1 << 2;                                      /* ARDY */
  75         break;
  76     case I2C_NACK:
  77         s->stat |= 1 << 1;                                      /* NACK */
  78         break;
  79     }
  80
  81     omap_i2c_interrupts_update(s);
  82 }
  83
  84 static int omap_i2c_rx(i2c_slave *i2c)
  85 {
  86     struct omap_i2c_s *s = (struct omap_i2c_s *) i2c;
  87     uint8_t ret = 0;
  88
  89     if ((~s->control >> 15) & 1)                                /* I2C_EN */
  90         return -1;
  91
  92     if (s->txlen)
  93         ret = s->fifo >> ((-- s->txlen) << 3) & 0xff;
  94     else
  95         s->stat |= 1 << 10;                                     /* XUDF */
  96     s->stat |= 1 << 4;                                          /* XRDY */
  97
  98     omap_i2c_interrupts_update(s);
  99     return ret;
 100 }
 101
 102 static int omap_i2c_tx(i2c_slave *i2c, uint8_t data)
 103 {
 104     struct omap_i2c_s *s = (struct omap_i2c_s *) i2c;
 105
 106     if ((~s->control >> 15) & 1)                                /* I2C_EN */
 107         return 1;
 108
 109     if (s->rxlen < 4)
 110         s->fifo |= data << ((s->rxlen ++) << 3);
 111     else
 112         s->stat |= 1 << 11;                                     /* ROVR */
 113     s->stat |= 1 << 3;                                          /* RRDY */
 114
 115     omap_i2c_interrupts_update(s);
 116     return 1;
 117 }
 118
 119 static void omap_i2c_fifo_run(struct omap_i2c_s *s)
 120 {
 121     int ack = 1;
 122
 123     if (!i2c_bus_busy(s->bus))
 124         return;
 125
 126     if ((s->control >> 2) & 1) {                                /* RM */
 127         if ((s->control >> 1) & 1) {                            /* STP */
 128             i2c_end_transfer(s->bus);
 129             s->control &= ~(1 << 1);                            /* STP */
 130             s->count_cur = s->count;
 131             s->txlen = 0;
 132         } else if ((s->control >> 9) & 1) {                     /* TRX */
 133             while (ack && s->txlen)
 134                 ack = (i2c_send(s->bus,
 135                                         (s->fifo >> ((-- s->txlen) << 3)) &
 136                                         0xff) >= 0);
 137             s->stat |= 1 << 4;                                  /* XRDY */
 138         } else {
 139             while (s->rxlen < 4)
 140                 s->fifo |= i2c_recv(s->bus) << ((s->rxlen ++) << 3);
 141             s->stat |= 1 << 3;                                  /* RRDY */
 142         }
 143     } else {
 144         if ((s->control >> 9) & 1) {                            /* TRX */
 145             while (ack && s->count_cur && s->txlen) {
 146                 ack = (i2c_send(s->bus,
 147                                         (s->fifo >> ((-- s->txlen) << 3)) &
 148                                         0xff) >= 0);
 149                 s->count_cur --;
 150             }
 151             if (ack && s->count_cur)
 152                 s->stat |= 1 << 4;                              /* XRDY */
 153             else
 154                 s->stat &= ~(1 << 4);                           /* XRDY */
 155             if (!s->count_cur) {
 156                 s->stat |= 1 << 2;                              /* ARDY */
 157                 s->control &= ~(1 << 10);                       /* MST */
 158             }
 159         } else {
 160             while (s->count_cur && s->rxlen < 4) {
 161                 s->fifo |= i2c_recv(s->bus) << ((s->rxlen ++) << 3);
 162                 s->count_cur --;
 163             }
 164             if (s->rxlen)
 165                 s->stat |= 1 << 3;                              /* RRDY */
 166             else
 167                 s->stat &= ~(1 << 3);                           /* RRDY */
 168         }
 169         if (!s->count_cur) {
 170             if ((s->control >> 1) & 1) {                        /* STP */
 171                 i2c_end_transfer(s->bus);
 172                 s->control &= ~(1 << 1);                        /* STP */
 173                 s->count_cur = s->count;
 174                 s->txlen = 0;
 175             } else {
 176                 s->stat |= 1 << 2;                              /* ARDY */
 177                 s->control &= ~(1 << 10);                       /* MST */
 178             }
 179         }
 180     }
 181
 182     s->stat |= (!ack) << 1;                                     /* NACK */
 183     if (!ack)
 184         s->control &= ~(1 << 1);                                /* STP */
 185 }
 186
 187 void omap_i2c_reset(struct omap_i2c_s *s)
 188 {
 189     s->mask = 0;
 190     s->stat = 0;
 191     s->dma = 0;
 192     s->count = 0;
 193     s->count_cur = 0;
 194     s->fifo = 0;
 195     s->rxlen = 0;
 196     s->txlen = 0;
 197     s->control = 0;
 198     s->addr[0] = 0;
 199     s->addr[1] = 0;
 200     s->divider = 0;
 201     s->times[0] = 0;
 202     s->times[1] = 0;
 203     s->test = 0;
 204 }
 205
 206 static uint32_t omap_i2c_read(void *opaque, target_phys_addr_t addr)
 207 {
 208     struct omap_i2c_s *s = (struct omap_i2c_s *) opaque;
 209     int offset = addr & OMAP_MPUI_REG_MASK;
 210     uint16_t ret;
 211
 212     switch (offset) {
 213     case 0x00:  /* I2C_REV */
 214         return s->revision;                                     /* REV */
 215
 216     case 0x04:  /* I2C_IE */
 217         return s->mask;
 218
 219     case 0x08:  /* I2C_STAT */
 220         return s->stat | (i2c_bus_busy(s->bus) << 12);
 221
 222     case 0x0c:  /* I2C_IV */
 223         if (s->revision >= OMAP2_INTR_REV)
 224             break;
 225         ret = ffs(s->stat & s->mask);
 226         if (ret)
 227             s->stat ^= 1 << (ret - 1);
 228         omap_i2c_interrupts_update(s);
 229         return ret;
 230
 231     case 0x10:  /* I2C_SYSS */
 232         return (s->control >> 15) & 1;                          /* I2C_EN */
 233
 234     case 0x14:  /* I2C_BUF */
 235         return s->dma;
 236
 237     case 0x18:  /* I2C_CNT */
 238         return s->count_cur;                                    /* DCOUNT */
 239
 240     case 0x1c:  /* I2C_DATA */
 241         ret = 0;
 242         if (s->control & (1 << 14)) {                           /* BE */
 243             ret |= ((s->fifo >> 0) & 0xff) << 8;
 244             ret |= ((s->fifo >> 8) & 0xff) << 0;
 245         } else {
 246             ret |= ((s->fifo >> 8) & 0xff) << 8;
 247             ret |= ((s->fifo >> 0) & 0xff) << 0;
 248         }
 249         if (s->rxlen == 1) {
 250             s->stat |= 1 << 15;                                 /* SBD */
 251             s->rxlen = 0;
 252         } else if (s->rxlen > 1) {
 253             if (s->rxlen > 2)
 254                 s->fifo >>= 16;
 255             s->rxlen -= 2;
 256         } else
 257             /* XXX: remote access (qualifier) error - what's that?  */;
 258         if (!s->rxlen) {
 259             s->stat &= ~(1 << 3);                               /* RRDY */
 260             if (((s->control >> 10) & 1) &&                     /* MST */
 261                             ((~s->control >> 9) & 1)) {         /* TRX */
 262                 s->stat |= 1 << 2;                              /* ARDY */
 263                 s->control &= ~(1 << 10);                       /* MST */
 264             }
 265         }
 266         s->stat &= ~(1 << 11);                                  /* ROVR */
 267         omap_i2c_fifo_run(s);
 268         omap_i2c_interrupts_update(s);
 269         return ret;
 270
 271     case 0x20:  /* I2C_SYSC */
 272         return 0;
 273
 274     case 0x24:  /* I2C_CON */
 275         return s->control;
 276
 277     case 0x28:  /* I2C_OA */
 278         return s->addr[0];
 279
 280     case 0x2c:  /* I2C_SA */
 281         return s->addr[1];
 282
 283     case 0x30:  /* I2C_PSC */
 284         return s->divider;
 285
 286     case 0x34:  /* I2C_SCLL */
 287         return s->times[0];
 288
 289     case 0x38:  /* I2C_SCLH */
 290         return s->times[1];
 291
 292     case 0x3c:  /* I2C_SYSTEST */
 293         if (s->test & (1 << 15)) {                              /* ST_EN */
 294             s->test ^= 0xa;
 295             return s->test;
 296         } else
 297             return s->test & ~0x300f;
 298     }
 299
 300     OMAP_BAD_REG(addr);
 301     return 0;
 302 }
 303
 304 static void omap_i2c_write(void *opaque, target_phys_addr_t addr,
 305                 uint32_t value)
 306 {
 307     struct omap_i2c_s *s = (struct omap_i2c_s *) opaque;
 308     int offset = addr & OMAP_MPUI_REG_MASK;
 309     int nack;
 310
 311     switch (offset) {
 312     case 0x00:  /* I2C_REV */
 313     case 0x0c:  /* I2C_IV */
 314     case 0x10:  /* I2C_SYSS */
 315         OMAP_RO_REG(addr);
 316         return;
 317
 318     case 0x04:  /* I2C_IE */
 319         s->mask = value & (s->revision < OMAP2_GC_REV ? 0x1f : 0x3f);
 320         break;
 321
 322     case 0x08:  /* I2C_STAT */
 323         if (s->revision < OMAP2_INTR_REV) {
 324             OMAP_RO_REG(addr);
 325             return;
 326         }
 327
 328         /* RRDY and XRDY are reset by hardware. (in all versions???) */
 329         s->stat &= ~(value & 0x27);
 330         omap_i2c_interrupts_update(s);
 331         break;
 332
 333     case 0x14:  /* I2C_BUF */
 334         s->dma = value & 0x8080;
 335         if (value & (1 << 15))                                  /* RDMA_EN */
 336             s->mask &= ~(1 << 3);                               /* RRDY_IE */
 337         if (value & (1 << 7))                                   /* XDMA_EN */
 338             s->mask &= ~(1 << 4);                               /* XRDY_IE */
 339         break;
 340
 341     case 0x18:  /* I2C_CNT */
 342         s->count = value;                                       /* DCOUNT */
 343         break;
 344
 345     case 0x1c:  /* I2C_DATA */
 346         if (s->txlen > 2) {
 347             /* XXX: remote access (qualifier) error - what's that?  */
 348             break;
 349         }
 350         s->fifo <<= 16;
 351         s->txlen += 2;
 352         if (s->control & (1 << 14)) {                           /* BE */
 353             s->fifo |= ((value >> 8) & 0xff) << 8;
 354             s->fifo |= ((value >> 0) & 0xff) << 0;
 355         } else {
 356             s->fifo |= ((value >> 0) & 0xff) << 8;
 357             s->fifo |= ((value >> 8) & 0xff) << 0;
 358         }
 359         s->stat &= ~(1 << 10);                                  /* XUDF */
 360         if (s->txlen > 2)
 361             s->stat &= ~(1 << 4);                               /* XRDY */
 362         omap_i2c_fifo_run(s);
 363         omap_i2c_interrupts_update(s);
 364         break;
 365
 366     case 0x20:  /* I2C_SYSC */
 367         if (s->revision < OMAP2_INTR_REV) {
 368             OMAP_BAD_REG(addr);
 369             return;
 370         }
 371
 372         if (value & 2)
 373             omap_i2c_reset(s);
 374         break;
 375
 376     case 0x24:  /* I2C_CON */
 377         s->control = value & 0xcf87;
 378         if (~value & (1 << 15)) {                               /* I2C_EN */
 379             if (s->revision < OMAP2_INTR_REV)
 380                 omap_i2c_reset(s);
 381             break;
 382         }
 383         if ((value & (1 << 15)) && !(value & (1 << 10))) {      /* MST */
 384             fprintf(stderr, "%s: I^2C slave mode not supported\n",
 385                             __FUNCTION__);
 386             break;
 387         }
 388         if ((value & (1 << 15)) && value & (1 << 8)) {          /* XA */
 389             fprintf(stderr, "%s: 10-bit addressing mode not supported\n",
 390                             __FUNCTION__);
 391             break;
 392         }
 393         if ((value & (1 << 15)) && value & (1 << 0)) {          /* STT */
 394             nack = !!i2c_start_transfer(s->bus, s->addr[1],     /* SA */
 395                             (~value >> 9) & 1);                 /* TRX */
 396             s->stat |= nack << 1;                               /* NACK */
 397             s->control &= ~(1 << 0);                            /* STT */
 398             s->fifo = 0;
 399             if (nack)
 400                 s->control &= ~(1 << 1);                        /* STP */
 401             else {
 402                 s->count_cur = s->count;
 403                 omap_i2c_fifo_run(s);
 404             }
 405             omap_i2c_interrupts_update(s);
 406         }
 407         break;
 408
 409     case 0x28:  /* I2C_OA */
 410         s->addr[0] = value & 0x3ff;
 411         i2c_set_slave_address(&s->slave, value & 0x7f);
 412         break;
 413
 414     case 0x2c:  /* I2C_SA */
 415         s->addr[1] = value & 0x3ff;
 416         break;
 417
 418     case 0x30:  /* I2C_PSC */
 419         s->divider = value;
 420         break;
 421
 422     case 0x34:  /* I2C_SCLL */
 423         s->times[0] = value;
 424         break;
 425
 426     case 0x38:  /* I2C_SCLH */
 427         s->times[1] = value;
 428         break;
 429
 430     case 0x3c:  /* I2C_SYSTEST */
 431         s->test = value & 0xf80f;
 432         if (value & (1 << 11))                                  /* SBB */
 433             if (s->revision >= OMAP2_INTR_REV) {
 434                 s->stat |= 0x3f;
 435                 omap_i2c_interrupts_update(s);
 436             }
 437         if (value & (1 << 15))                                  /* ST_EN */
 438             fprintf(stderr, "%s: System Test not supported\n", __FUNCTION__);
 439         break;
 440
 441     default:
 442         OMAP_BAD_REG(addr);
 443         return;
 444     }
 445 }
 446
 447 static void omap_i2c_writeb(void *opaque, target_phys_addr_t addr,
 448                 uint32_t value)
 449 {
 450     struct omap_i2c_s *s = (struct omap_i2c_s *) opaque;
 451     int offset = addr & OMAP_MPUI_REG_MASK;
 452
 453     switch (offset) {
 454     case 0x1c:  /* I2C_DATA */
 455         if (s->txlen > 2) {
 456             /* XXX: remote access (qualifier) error - what's that?  */
 457             break;
 458         }
 459         s->fifo <<= 8;
 460         s->txlen += 1;
 461         s->fifo |= value & 0xff;
 462         s->stat &= ~(1 << 10);                                  /* XUDF */
 463         if (s->txlen > 2)
 464             s->stat &= ~(1 << 4);                               /* XRDY */
 465         omap_i2c_fifo_run(s);
 466         omap_i2c_interrupts_update(s);
 467         break;
 468
 469     default:
 470         OMAP_BAD_REG(addr);
 471         return;
 472     }
 473 }
 474
 475 static CPUReadMemoryFunc *omap_i2c_readfn[] = {
 476     omap_badwidth_read16,
 477     omap_i2c_read,
 478     omap_badwidth_read16,
 479 };
 480
 481 static CPUWriteMemoryFunc *omap_i2c_writefn[] = {
 482     omap_i2c_writeb,    /* Only the last fifo write can be 8 bit.  */
 483     omap_i2c_write,
 484     omap_badwidth_write16,
 485 };
 486
 487 struct omap_i2c_s *omap_i2c_init(target_phys_addr_t base,
 488                 qemu_irq irq, qemu_irq *dma, omap_clk clk)
 489 {
 490     int iomemtype;
 491     struct omap_i2c_s *s = (struct omap_i2c_s *)
 492             qemu_mallocz(sizeof(struct omap_i2c_s));
 493
 494     /* TODO: set a value greater or equal to real hardware */
 495     s->revision = 0x11;
 496     s->base = base;
 497     s->irq = irq;
 498     s->drq[0] = dma[0];
 499     s->drq[1] = dma[1];
 500     s->slave.event = omap_i2c_event;
 501     s->slave.recv = omap_i2c_rx;
 502     s->slave.send = omap_i2c_tx;
 503     s->bus = i2c_init_bus();
 504     omap_i2c_reset(s);
 505
 506     iomemtype = cpu_register_io_memory(0, omap_i2c_readfn,
 507                     omap_i2c_writefn, s);
 508     cpu_register_physical_memory(s->base, 0x800, iomemtype);
 509
 510     return s;
 511 }
 512
 513 struct omap_i2c_s *omap2_i2c_init(struct omap_target_agent_s *ta,
 514                 qemu_irq irq, qemu_irq *dma, omap_clk fclk, omap_clk iclk)
 515 {
 516     int iomemtype;
 517     struct omap_i2c_s *s = (struct omap_i2c_s *)
 518             qemu_mallocz(sizeof(struct omap_i2c_s));
 519
 520     s->revision = 0x34;
 521     s->irq = irq;
 522     s->drq[0] = dma[0];
 523     s->drq[1] = dma[1];
 524     s->slave.event = omap_i2c_event;
 525     s->slave.recv = omap_i2c_rx;
 526     s->slave.send = omap_i2c_tx;
 527     s->bus = i2c_init_bus();
 528     omap_i2c_reset(s);
 529
 530     iomemtype = l4_register_io_memory(0, omap_i2c_readfn,
 531                     omap_i2c_writefn, s);
 532     s->base = omap_l4_attach(ta, 0, iomemtype);
 533
 534     return s;
 535 }
 536
 537 i2c_bus *omap_i2c_bus(struct omap_i2c_s *s)
 538 {
 539     return s->bus;
 540 }