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