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, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  */
  20 #include "hw.h"
  21 #include "i2c.h"
  22 #include "omap.h"
  23
  24 struct omap_i2c_s {
  25     qemu_irq irq;
  26     qemu_irq drq[2];
  27     i2c_bus *bus;
  28
  29     uint8_t revision;
  30     uint8_t mask;
  31     uint16_t stat;
  32     uint16_t dma;
  33     uint16_t count;
  34     int count_cur;
  35     uint32_t fifo;
  36     int rxlen;
  37     int txlen;
  38     uint16_t control;
  39     uint16_t addr[2];
  40     uint8_t divider;
  41     uint8_t times[2];
  42     uint16_t test;
  43 };
  44
  45 #define OMAP2_INTR_REV  0x34
  46 #define OMAP2_GC_REV    0x34
  47
  48 static void omap_i2c_interrupts_update(struct omap_i2c_s *s)
  49 {
  50     qemu_set_irq(s->irq, s->stat & s->mask);
  51     if ((s->dma >> 15) & 1)                                     /* RDMA_EN */
  52         qemu_set_irq(s->drq[0], (s->stat >> 3) & 1);            /* RRDY */
  53     if ((s->dma >> 7) & 1)                                      /* XDMA_EN */
  54         qemu_set_irq(s->drq[1], (s->stat >> 4) & 1);            /* XRDY */
  55 }
  56
  57 static void omap_i2c_fifo_run(struct omap_i2c_s *s)
  58 {
  59     int ack = 1;
  60
  61     if (!i2c_bus_busy(s->bus))
  62         return;
  63
  64     if ((s->control >> 2) & 1) {                                /* RM */
  65         if ((s->control >> 1) & 1) {                            /* STP */
  66             i2c_end_transfer(s->bus);
  67             s->control &= ~(1 << 1);                            /* STP */
  68             s->count_cur = s->count;
  69             s->txlen = 0;
  70         } else if ((s->control >> 9) & 1) {                     /* TRX */
  71             while (ack && s->txlen)
  72                 ack = (i2c_send(s->bus,
  73                                         (s->fifo >> ((-- s->txlen) << 3)) &
  74                                         0xff) >= 0);
  75             s->stat |= 1 << 4;                                  /* XRDY */
  76         } else {
  77             while (s->rxlen < 4)
  78                 s->fifo |= i2c_recv(s->bus) << ((s->rxlen ++) << 3);
  79             s->stat |= 1 << 3;                                  /* RRDY */
  80         }
  81     } else {
  82         if ((s->control >> 9) & 1) {                            /* TRX */
  83             while (ack && s->count_cur && s->txlen) {
  84                 ack = (i2c_send(s->bus,
  85                                         (s->fifo >> ((-- s->txlen) << 3)) &
  86                                         0xff) >= 0);
  87                 s->count_cur --;
  88             }
  89             if (ack && s->count_cur)
  90                 s->stat |= 1 << 4;                              /* XRDY */
  91             else
  92                 s->stat &= ~(1 << 4);                           /* XRDY */
  93             if (!s->count_cur) {
  94                 s->stat |= 1 << 2;                              /* ARDY */
  95                 s->control &= ~(1 << 10);                       /* MST */
  96             }
  97         } else {
  98             while (s->count_cur && s->rxlen < 4) {
  99                 s->fifo |= i2c_recv(s->bus) << ((s->rxlen ++) << 3);
 100                 s->count_cur --;
 101             }
 102             if (s->rxlen)
 103                 s->stat |= 1 << 3;                              /* RRDY */
 104             else
 105                 s->stat &= ~(1 << 3);                           /* RRDY */
 106         }
 107         if (!s->count_cur) {
 108             if ((s->control >> 1) & 1) {                        /* STP */
 109                 i2c_end_transfer(s->bus);
 110                 s->control &= ~(1 << 1);                        /* STP */
 111                 s->count_cur = s->count;
 112                 s->txlen = 0;
 113             } else {
 114                 s->stat |= 1 << 2;                              /* ARDY */
 115                 s->control &= ~(1 << 10);                       /* MST */
 116             }
 117         }
 118     }
 119
 120     s->stat |= (!ack) << 1;                                     /* NACK */
 121     if (!ack)
 122         s->control &= ~(1 << 1);                                /* STP */
 123 }
 124
 125 void omap_i2c_reset(struct omap_i2c_s *s)
 126 {
 127     s->mask = 0;
 128     s->stat = 0;
 129     s->dma = 0;
 130     s->count = 0;
 131     s->count_cur = 0;
 132     s->fifo = 0;
 133     s->rxlen = 0;
 134     s->txlen = 0;
 135     s->control = 0;
 136     s->addr[0] = 0;
 137     s->addr[1] = 0;
 138     s->divider = 0;
 139     s->times[0] = 0;
 140     s->times[1] = 0;
 141     s->test = 0;
 142 }
 143
 144 static uint32_t omap_i2c_read(void *opaque, target_phys_addr_t addr)
 145 {
 146     struct omap_i2c_s *s = (struct omap_i2c_s *) opaque;
 147     int offset = addr & OMAP_MPUI_REG_MASK;
 148     uint16_t ret;
 149
 150     switch (offset) {
 151     case 0x00:  /* I2C_REV */
 152         return s->revision;                                     /* REV */
 153
 154     case 0x04:  /* I2C_IE */
 155         return s->mask;
 156
 157     case 0x08:  /* I2C_STAT */
 158         return s->stat | (i2c_bus_busy(s->bus) << 12);
 159
 160     case 0x0c:  /* I2C_IV */
 161         if (s->revision >= OMAP2_INTR_REV)
 162             break;
 163         ret = ffs(s->stat & s->mask);
 164         if (ret)
 165             s->stat ^= 1 << (ret - 1);
 166         omap_i2c_interrupts_update(s);
 167         return ret;
 168
 169     case 0x10:  /* I2C_SYSS */
 170         return (s->control >> 15) & 1;                          /* I2C_EN */
 171
 172     case 0x14:  /* I2C_BUF */
 173         return s->dma;
 174
 175     case 0x18:  /* I2C_CNT */
 176         return s->count_cur;                                    /* DCOUNT */
 177
 178     case 0x1c:  /* I2C_DATA */
 179         ret = 0;
 180         if (s->control & (1 << 14)) {                           /* BE */
 181             ret |= ((s->fifo >> 0) & 0xff) << 8;
 182             ret |= ((s->fifo >> 8) & 0xff) << 0;
 183         } else {
 184             ret |= ((s->fifo >> 8) & 0xff) << 8;
 185             ret |= ((s->fifo >> 0) & 0xff) << 0;
 186         }
 187         if (s->rxlen == 1) {
 188             s->stat |= 1 << 15;                                 /* SBD */
 189             s->rxlen = 0;
 190         } else if (s->rxlen > 1) {
 191             if (s->rxlen > 2)
 192                 s->fifo >>= 16;
 193             s->rxlen -= 2;
 194         } else
 195             /* XXX: remote access (qualifier) error - what's that?  */;
 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 *omap_i2c_readfn[] = {
 413     omap_badwidth_read16,
 414     omap_i2c_read,
 415     omap_badwidth_read16,
 416 };
 417
 418 static CPUWriteMemoryFunc *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(0, 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(0, 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 }