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         }
 196         if (!s->rxlen) {
 197             s->stat &= ~(1 << 3);                               /* RRDY */
 198             if (((s->control >> 10) & 1) &&                     /* MST */
 199                             ((~s->control >> 9) & 1)) {         /* TRX */
 200                 s->stat |= 1 << 2;                              /* ARDY */
 201                 s->control &= ~(1 << 10);                       /* MST */
 202             }
 203         }
 204         s->stat &= ~(1 << 11);                                  /* ROVR */
 205         omap_i2c_fifo_run(s);
 206         omap_i2c_interrupts_update(s);
 207         return ret;
 208
 209     case 0x20:  /* I2C_SYSC */
 210         return 0;
 211
 212     case 0x24:  /* I2C_CON */
 213         return s->control;
 214
 215     case 0x28:  /* I2C_OA */
 216         return s->addr[0];
 217
 218     case 0x2c:  /* I2C_SA */
 219         return s->addr[1];
 220
 221     case 0x30:  /* I2C_PSC */
 222         return s->divider;
 223
 224     case 0x34:  /* I2C_SCLL */
 225         return s->times[0];
 226
 227     case 0x38:  /* I2C_SCLH */
 228         return s->times[1];
 229
 230     case 0x3c:  /* I2C_SYSTEST */
 231         if (s->test & (1 << 15)) {                              /* ST_EN */
 232             s->test ^= 0xa;
 233             return s->test;
 234         } else
 235             return s->test & ~0x300f;
 236     }
 237
 238     OMAP_BAD_REG(addr);
 239     return 0;
 240 }
 241
 242 static void omap_i2c_write(void *opaque, target_phys_addr_t addr,
 243                 uint32_t value)
 244 {
 245     struct omap_i2c_s *s = (struct omap_i2c_s *) opaque;
 246     int offset = addr & OMAP_MPUI_REG_MASK;
 247     int nack;
 248
 249     switch (offset) {
 250     case 0x00:  /* I2C_REV */
 251     case 0x0c:  /* I2C_IV */
 252     case 0x10:  /* I2C_SYSS */
 253         OMAP_RO_REG(addr);
 254         return;
 255
 256     case 0x04:  /* I2C_IE */
 257         s->mask = value & (s->revision < OMAP2_GC_REV ? 0x1f : 0x3f);
 258         break;
 259
 260     case 0x08:  /* I2C_STAT */
 261         if (s->revision < OMAP2_INTR_REV) {
 262             OMAP_RO_REG(addr);
 263             return;
 264         }
 265
 266         /* RRDY and XRDY are reset by hardware. (in all versions???) */
 267         s->stat &= ~(value & 0x27);
 268         omap_i2c_interrupts_update(s);
 269         break;
 270
 271     case 0x14:  /* I2C_BUF */
 272         s->dma = value & 0x8080;
 273         if (value & (1 << 15))                                  /* RDMA_EN */
 274             s->mask &= ~(1 << 3);                               /* RRDY_IE */
 275         if (value & (1 << 7))                                   /* XDMA_EN */
 276             s->mask &= ~(1 << 4);                               /* XRDY_IE */
 277         break;
 278
 279     case 0x18:  /* I2C_CNT */
 280         s->count = value;                                       /* DCOUNT */
 281         break;
 282
 283     case 0x1c:  /* I2C_DATA */
 284         if (s->txlen > 2) {
 285             /* XXX: remote access (qualifier) error - what's that?  */
 286             break;
 287         }
 288         s->fifo <<= 16;
 289         s->txlen += 2;
 290         if (s->control & (1 << 14)) {                           /* BE */
 291             s->fifo |= ((value >> 8) & 0xff) << 8;
 292             s->fifo |= ((value >> 0) & 0xff) << 0;
 293         } else {
 294             s->fifo |= ((value >> 0) & 0xff) << 8;
 295             s->fifo |= ((value >> 8) & 0xff) << 0;
 296         }
 297         s->stat &= ~(1 << 10);                                  /* XUDF */
 298         if (s->txlen > 2)
 299             s->stat &= ~(1 << 4);                               /* XRDY */
 300         omap_i2c_fifo_run(s);
 301         omap_i2c_interrupts_update(s);
 302         break;
 303
 304     case 0x20:  /* I2C_SYSC */
 305         if (s->revision < OMAP2_INTR_REV) {
 306             OMAP_BAD_REG(addr);
 307             return;
 308         }
 309
 310         if (value & 2)
 311             omap_i2c_reset(s);
 312         break;
 313
 314     case 0x24:  /* I2C_CON */
 315         s->control = value & 0xcf87;
 316         if (~value & (1 << 15)) {                               /* I2C_EN */
 317             if (s->revision < OMAP2_INTR_REV)
 318                 omap_i2c_reset(s);
 319             break;
 320         }
 321         if ((value & (1 << 15)) && !(value & (1 << 10))) {      /* MST */
 322             fprintf(stderr, "%s: I^2C slave mode not supported\n",
 323                             __FUNCTION__);
 324             break;
 325         }
 326         if ((value & (1 << 15)) && value & (1 << 8)) {          /* XA */
 327             fprintf(stderr, "%s: 10-bit addressing mode not supported\n",
 328                             __FUNCTION__);
 329             break;
 330         }
 331         if ((value & (1 << 15)) && value & (1 << 0)) {          /* STT */
 332             nack = !!i2c_start_transfer(s->bus, s->addr[1],     /* SA */
 333                             (~value >> 9) & 1);                 /* TRX */
 334             s->stat |= nack << 1;                               /* NACK */
 335             s->control &= ~(1 << 0);                            /* STT */
 336             s->fifo = 0;
 337             if (nack)
 338                 s->control &= ~(1 << 1);                        /* STP */
 339             else {
 340                 s->count_cur = s->count;
 341                 omap_i2c_fifo_run(s);
 342             }
 343             omap_i2c_interrupts_update(s);
 344         }
 345         break;
 346
 347     case 0x28:  /* I2C_OA */
 348         s->addr[0] = value & 0x3ff;
 349         break;
 350
 351     case 0x2c:  /* I2C_SA */
 352         s->addr[1] = value & 0x3ff;
 353         break;
 354
 355     case 0x30:  /* I2C_PSC */
 356         s->divider = value;
 357         break;
 358
 359     case 0x34:  /* I2C_SCLL */
 360         s->times[0] = value;
 361         break;
 362
 363     case 0x38:  /* I2C_SCLH */
 364         s->times[1] = value;
 365         break;
 366
 367     case 0x3c:  /* I2C_SYSTEST */
 368         s->test = value & 0xf80f;
 369         if (value & (1 << 11))                                  /* SBB */
 370             if (s->revision >= OMAP2_INTR_REV) {
 371                 s->stat |= 0x3f;
 372                 omap_i2c_interrupts_update(s);
 373             }
 374         if (value & (1 << 15))                                  /* ST_EN */
 375             fprintf(stderr, "%s: System Test not supported\n", __FUNCTION__);
 376         break;
 377
 378     default:
 379         OMAP_BAD_REG(addr);
 380         return;
 381     }
 382 }
 383
 384 static void omap_i2c_writeb(void *opaque, target_phys_addr_t addr,
 385                 uint32_t value)
 386 {
 387     struct omap_i2c_s *s = (struct omap_i2c_s *) opaque;
 388     int offset = addr & OMAP_MPUI_REG_MASK;
 389
 390     switch (offset) {
 391     case 0x1c:  /* I2C_DATA */
 392         if (s->txlen > 2) {
 393             /* XXX: remote access (qualifier) error - what's that?  */
 394             break;
 395         }
 396         s->fifo <<= 8;
 397         s->txlen += 1;
 398         s->fifo |= value & 0xff;
 399         s->stat &= ~(1 << 10);                                  /* XUDF */
 400         if (s->txlen > 2)
 401             s->stat &= ~(1 << 4);                               /* XRDY */
 402         omap_i2c_fifo_run(s);
 403         omap_i2c_interrupts_update(s);
 404         break;
 405
 406     default:
 407         OMAP_BAD_REG(addr);
 408         return;
 409     }
 410 }
 411
 412 static CPUReadMemoryFunc * const omap_i2c_readfn[] = {
 413     omap_badwidth_read16,
 414     omap_i2c_read,
 415     omap_badwidth_read16,
 416 };
 417
 418 static CPUWriteMemoryFunc * const omap_i2c_writefn[] = {
 419     omap_i2c_writeb,    /* Only the last fifo write can be 8 bit.  */
 420     omap_i2c_write,
 421     omap_badwidth_write16,
 422 };
 423
 424 struct omap_i2c_s *omap_i2c_init(target_phys_addr_t base,
 425                 qemu_irq irq, qemu_irq *dma, omap_clk clk)
 426 {
 427     int iomemtype;
 428     struct omap_i2c_s *s = (struct omap_i2c_s *)
 429             qemu_mallocz(sizeof(struct omap_i2c_s));
 430
 431     /* TODO: set a value greater or equal to real hardware */
 432     s->revision = 0x11;
 433     s->irq = irq;
 434     s->drq[0] = dma[0];
 435     s->drq[1] = dma[1];
 436     s->bus = i2c_init_bus(NULL, "i2c");
 437     omap_i2c_reset(s);
 438
 439     iomemtype = cpu_register_io_memory(omap_i2c_readfn,
 440                     omap_i2c_writefn, s);
 441     cpu_register_physical_memory(base, 0x800, iomemtype);
 442
 443     return s;
 444 }
 445
 446 struct omap_i2c_s *omap2_i2c_init(struct omap_target_agent_s *ta,
 447                 qemu_irq irq, qemu_irq *dma, omap_clk fclk, omap_clk iclk)
 448 {
 449     int iomemtype;
 450     struct omap_i2c_s *s = (struct omap_i2c_s *)
 451             qemu_mallocz(sizeof(struct omap_i2c_s));
 452
 453     s->revision = 0x34;
 454     s->irq = irq;
 455     s->drq[0] = dma[0];
 456     s->drq[1] = dma[1];
 457     s->bus = i2c_init_bus(NULL, "i2c");
 458     omap_i2c_reset(s);
 459
 460     iomemtype = l4_register_io_memory(omap_i2c_readfn,
 461                     omap_i2c_writefn, s);
 462     omap_l4_attach(ta, 0, iomemtype);
 463
 464     return s;
 465 }
 466
 467 i2c_bus *omap_i2c_bus(struct omap_i2c_s *s)
 468 {
 469     return s->bus;
 470 }