hw/i2c/pm_smbus.c

   1 /*
   2  * PC SMBus implementation
   3  * splitted from acpi.c
   4  *
   5  * Copyright (c) 2006 Fabrice Bellard
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License version 2 as published by the Free Software Foundation.
  10  *
  11  * This library 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 GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see
  18  * <http://www.gnu.org/licenses/>.
  19  */
  20 #include "qemu/osdep.h"
  21 #include "hw/hw.h"
  22 #include "hw/boards.h"
  23 #include "hw/i2c/pm_smbus.h"
  24 #include "hw/i2c/smbus_master.h"
  25
  26 #define SMBHSTSTS       0x00
  27 #define SMBHSTCNT       0x02
  28 #define SMBHSTCMD       0x03
  29 #define SMBHSTADD       0x04
  30 #define SMBHSTDAT0      0x05
  31 #define SMBHSTDAT1      0x06
  32 #define SMBBLKDAT       0x07
  33 #define SMBAUXCTL       0x0d
  34
  35 #define STS_HOST_BUSY   (1 << 0)
  36 #define STS_INTR        (1 << 1)
  37 #define STS_DEV_ERR     (1 << 2)
  38 #define STS_BUS_ERR     (1 << 3)
  39 #define STS_FAILED      (1 << 4)
  40 #define STS_SMBALERT    (1 << 5)
  41 #define STS_INUSE_STS   (1 << 6)
  42 #define STS_BYTE_DONE   (1 << 7)
  43 /* Signs of successfully transaction end :
  44 *  ByteDoneStatus = 1 (STS_BYTE_DONE) and INTR = 1 (STS_INTR )
  45 */
  46
  47 #define CTL_INTREN      (1 << 0)
  48 #define CTL_KILL        (1 << 1)
  49 #define CTL_LAST_BYTE   (1 << 5)
  50 #define CTL_START       (1 << 6)
  51 #define CTL_PEC_EN      (1 << 7)
  52 #define CTL_RETURN_MASK 0x1f
  53
  54 #define PROT_QUICK          0
  55 #define PROT_BYTE           1
  56 #define PROT_BYTE_DATA      2
  57 #define PROT_WORD_DATA      3
  58 #define PROT_PROC_CALL      4
  59 #define PROT_BLOCK_DATA     5
  60 #define PROT_I2C_BLOCK_READ 6
  61
  62 #define AUX_PEC       (1 << 0)
  63 #define AUX_BLK       (1 << 1)
  64 #define AUX_MASK      0x3
  65
  66 /*#define DEBUG*/
  67
  68 #ifdef DEBUG
  69 # define SMBUS_DPRINTF(format, ...)     printf(format, ## __VA_ARGS__)
  70 #else
  71 # define SMBUS_DPRINTF(format, ...)     do { } while (0)
  72 #endif
  73
  74
  75 static void smb_transaction(PMSMBus *s)
  76 {
  77     uint8_t prot = (s->smb_ctl >> 2) & 0x07;
  78     uint8_t read = s->smb_addr & 0x01;
  79     uint8_t cmd = s->smb_cmd;
  80     uint8_t addr = s->smb_addr >> 1;
  81     I2CBus *bus = s->smbus;
  82     int ret;
  83
  84     SMBUS_DPRINTF("SMBus trans addr=0x%02x prot=0x%02x\n", addr, prot);
  85     /* Transaction isn't exec if STS_DEV_ERR bit set */
  86     if ((s->smb_stat & STS_DEV_ERR) != 0)  {
  87         goto error;
  88     }
  89
  90     switch(prot) {
  91     case PROT_QUICK:
  92         ret = smbus_quick_command(bus, addr, read);
  93         goto done;
  94     case PROT_BYTE:
  95         if (read) {
  96             ret = smbus_receive_byte(bus, addr);
  97             goto data8;
  98         } else {
  99             ret = smbus_send_byte(bus, addr, cmd);
 100             goto done;
 101         }
 102     case PROT_BYTE_DATA:
 103         if (read) {
 104             ret = smbus_read_byte(bus, addr, cmd);
 105             goto data8;
 106         } else {
 107             ret = smbus_write_byte(bus, addr, cmd, s->smb_data0);
 108             goto done;
 109         }
 110         break;
 111     case PROT_WORD_DATA:
 112         if (read) {
 113             ret = smbus_read_word(bus, addr, cmd);
 114             goto data16;
 115         } else {
 116             ret = smbus_write_word(bus, addr, cmd,
 117                                    (s->smb_data1 << 8) | s->smb_data0);
 118             goto done;
 119         }
 120         break;
 121     case PROT_I2C_BLOCK_READ:
 122         /* According to the Linux i2c-i801 driver:
 123          *   NB: page 240 of ICH5 datasheet shows that the R/#W
 124          *   bit should be cleared here, even when reading.
 125          *   However if SPD Write Disable is set (Lynx Point and later),
 126          *   the read will fail if we don't set the R/#W bit.
 127          * So at least Linux may or may not set the read bit here.
 128          * So just ignore the read bit for this command.
 129          */
 130         if (i2c_start_transfer(bus, addr, 0)) {
 131             goto error;
 132         }
 133         ret = i2c_send(bus, s->smb_data1);
 134         if (ret) {
 135             goto error;
 136         }
 137         if (i2c_start_transfer(bus, addr, 1)) {
 138             goto error;
 139         }
 140         s->in_i2c_block_read = true;
 141         s->smb_blkdata = i2c_recv(s->smbus);
 142         s->op_done = false;
 143         s->smb_stat |= STS_HOST_BUSY | STS_BYTE_DONE;
 144         goto out;
 145
 146     case PROT_BLOCK_DATA:
 147         if (read) {
 148             ret = smbus_read_block(bus, addr, cmd, s->smb_data,
 149                                    sizeof(s->smb_data), !s->i2c_enable,
 150                                    !s->i2c_enable);
 151             if (ret < 0) {
 152                 goto error;
 153             }
 154             s->smb_index = 0;
 155             s->op_done = false;
 156             if (s->smb_auxctl & AUX_BLK) {
 157                 s->smb_stat |= STS_INTR;
 158             } else {
 159                 s->smb_blkdata = s->smb_data[0];
 160                 s->smb_stat |= STS_HOST_BUSY | STS_BYTE_DONE;
 161             }
 162             s->smb_data0 = ret;
 163             goto out;
 164         } else {
 165             if (s->smb_auxctl & AUX_BLK) {
 166                 if (s->smb_index != s->smb_data0) {
 167                     s->smb_index = 0;
 168                     goto error;
 169                 }
 170                 /* Data is already all written to the queue, just do
 171                    the operation. */
 172                 s->smb_index = 0;
 173                 ret = smbus_write_block(bus, addr, cmd, s->smb_data,
 174                                         s->smb_data0, !s->i2c_enable);
 175                 if (ret < 0) {
 176                     goto error;
 177                 }
 178                 s->op_done = true;
 179                 s->smb_stat |= STS_INTR;
 180                 s->smb_stat &= ~STS_HOST_BUSY;
 181             } else {
 182                 s->op_done = false;
 183                 s->smb_stat |= STS_HOST_BUSY | STS_BYTE_DONE;
 184                 s->smb_data[0] = s->smb_blkdata;
 185                 s->smb_index = 0;
 186                 ret = 0;
 187             }
 188             goto out;
 189         }
 190         break;
 191     default:
 192         goto error;
 193     }
 194     abort();
 195
 196 data16:
 197     if (ret < 0) {
 198         goto error;
 199     }
 200     s->smb_data1 = ret >> 8;
 201 data8:
 202     if (ret < 0) {
 203         goto error;
 204     }
 205     s->smb_data0 = ret;
 206 done:
 207     if (ret < 0) {
 208         goto error;
 209     }
 210     s->smb_stat |= STS_INTR;
 211 out:
 212     return;
 213
 214 error:
 215     s->smb_stat |= STS_DEV_ERR;
 216     return;
 217 }
 218
 219 static void smb_transaction_start(PMSMBus *s)
 220 {
 221     if (s->smb_ctl & CTL_INTREN) {
 222         smb_transaction(s);
 223         s->start_transaction_on_status_read = false;
 224     } else {
 225         /* Do not execute immediately the command; it will be
 226          * executed when guest will read SMB_STAT register.  This
 227          * is to work around a bug in AMIBIOS (that is working
 228          * around another bug in some specific hardware) where
 229          * it waits for STS_HOST_BUSY to be set before waiting
 230          * checking for status.  If STS_HOST_BUSY doesn't get
 231          * set, it gets stuck. */
 232         s->smb_stat |= STS_HOST_BUSY;
 233         s->start_transaction_on_status_read = true;
 234     }
 235 }
 236
 237 static bool
 238 smb_irq_value(PMSMBus *s)
 239 {
 240     return ((s->smb_stat & ~STS_HOST_BUSY) != 0) && (s->smb_ctl & CTL_INTREN);
 241 }
 242
 243 static bool
 244 smb_byte_by_byte(PMSMBus *s)
 245 {
 246     if (s->op_done) {
 247         return false;
 248     }
 249     if (s->in_i2c_block_read) {
 250         return true;
 251     }
 252     return !(s->smb_auxctl & AUX_BLK);
 253 }
 254
 255 static void smb_ioport_writeb(void *opaque, hwaddr addr, uint64_t val,
 256                               unsigned width)
 257 {
 258     PMSMBus *s = opaque;
 259     uint8_t clear_byte_done;
 260
 261     SMBUS_DPRINTF("SMB writeb port=0x%04" HWADDR_PRIx
 262                   " val=0x%02" PRIx64 "\n", addr, val);
 263     switch(addr) {
 264     case SMBHSTSTS:
 265         clear_byte_done = s->smb_stat & val & STS_BYTE_DONE;
 266         s->smb_stat &= ~(val & ~STS_HOST_BUSY);
 267         if (clear_byte_done && smb_byte_by_byte(s)) {
 268             uint8_t read = s->smb_addr & 0x01;
 269
 270             if (s->in_i2c_block_read) {
 271                 /* See comment below PROT_I2C_BLOCK_READ above. */
 272                 read = 1;
 273             }
 274
 275             s->smb_index++;
 276             if (s->smb_index >= PM_SMBUS_MAX_MSG_SIZE) {
 277                 s->smb_index = 0;
 278             }
 279             if (!read && s->smb_index == s->smb_data0) {
 280                 uint8_t prot = (s->smb_ctl >> 2) & 0x07;
 281                 uint8_t cmd = s->smb_cmd;
 282                 uint8_t addr = s->smb_addr >> 1;
 283                 int ret;
 284
 285                 if (prot == PROT_I2C_BLOCK_READ) {
 286                     s->smb_stat |= STS_DEV_ERR;
 287                     goto out;
 288                 }
 289
 290                 ret = smbus_write_block(s->smbus, addr, cmd, s->smb_data,
 291                                         s->smb_data0, !s->i2c_enable);
 292                 if (ret < 0) {
 293                     s->smb_stat |= STS_DEV_ERR;
 294                     goto out;
 295                 }
 296                 s->op_done = true;
 297                 s->smb_stat |= STS_INTR;
 298                 s->smb_stat &= ~STS_HOST_BUSY;
 299             } else if (!read) {
 300                 s->smb_data[s->smb_index] = s->smb_blkdata;
 301                 s->smb_stat |= STS_BYTE_DONE;
 302             } else if (s->smb_ctl & CTL_LAST_BYTE) {
 303                 s->op_done = true;
 304                 if (s->in_i2c_block_read) {
 305                     s->in_i2c_block_read = false;
 306                     s->smb_blkdata = i2c_recv(s->smbus);
 307                     i2c_nack(s->smbus);
 308                     i2c_end_transfer(s->smbus);
 309                 } else {
 310                     s->smb_blkdata = s->smb_data[s->smb_index];
 311                 }
 312                 s->smb_index = 0;
 313                 s->smb_stat |= STS_INTR;
 314                 s->smb_stat &= ~STS_HOST_BUSY;
 315             } else {
 316                 if (s->in_i2c_block_read) {
 317                     s->smb_blkdata = i2c_recv(s->smbus);
 318                 } else {
 319                     s->smb_blkdata = s->smb_data[s->smb_index];
 320                 }
 321                 s->smb_stat |= STS_BYTE_DONE;
 322             }
 323         }
 324         break;
 325     case SMBHSTCNT:
 326         s->smb_ctl = val & ~CTL_START; /* CTL_START always reads 0 */
 327         if (val & CTL_START) {
 328             if (!s->op_done) {
 329                 s->smb_index = 0;
 330                 s->op_done = true;
 331                 if (s->in_i2c_block_read) {
 332                     s->in_i2c_block_read = false;
 333                     i2c_end_transfer(s->smbus);
 334                 }
 335             }
 336             smb_transaction_start(s);
 337         }
 338         if (s->smb_ctl & CTL_KILL) {
 339             s->op_done = true;
 340             s->smb_index = 0;
 341             s->smb_stat |= STS_FAILED;
 342             s->smb_stat &= ~STS_HOST_BUSY;
 343         }
 344         break;
 345     case SMBHSTCMD:
 346         s->smb_cmd = val;
 347         break;
 348     case SMBHSTADD:
 349         s->smb_addr = val;
 350         break;
 351     case SMBHSTDAT0:
 352         s->smb_data0 = val;
 353         break;
 354     case SMBHSTDAT1:
 355         s->smb_data1 = val;
 356         break;
 357     case SMBBLKDAT:
 358         if (s->smb_index >= PM_SMBUS_MAX_MSG_SIZE) {
 359             s->smb_index = 0;
 360         }
 361         if (s->smb_auxctl & AUX_BLK) {
 362             s->smb_data[s->smb_index++] = val;
 363         } else {
 364             s->smb_blkdata = val;
 365         }
 366         break;
 367     case SMBAUXCTL:
 368         s->smb_auxctl = val & AUX_MASK;
 369         break;
 370     default:
 371         break;
 372     }
 373
 374  out:
 375     if (s->set_irq) {
 376         s->set_irq(s, smb_irq_value(s));
 377     }
 378 }
 379
 380 static uint64_t smb_ioport_readb(void *opaque, hwaddr addr, unsigned width)
 381 {
 382     PMSMBus *s = opaque;
 383     uint32_t val;
 384
 385     switch(addr) {
 386     case SMBHSTSTS:
 387         val = s->smb_stat;
 388         if (s->start_transaction_on_status_read) {
 389             /* execute command now */
 390             s->start_transaction_on_status_read = false;
 391             s->smb_stat &= ~STS_HOST_BUSY;
 392             smb_transaction(s);
 393         }
 394         break;
 395     case SMBHSTCNT:
 396         val = s->smb_ctl & CTL_RETURN_MASK;
 397         break;
 398     case SMBHSTCMD:
 399         val = s->smb_cmd;
 400         break;
 401     case SMBHSTADD:
 402         val = s->smb_addr;
 403         break;
 404     case SMBHSTDAT0:
 405         val = s->smb_data0;
 406         break;
 407     case SMBHSTDAT1:
 408         val = s->smb_data1;
 409         break;
 410     case SMBBLKDAT:
 411         if (s->smb_auxctl & AUX_BLK && !s->in_i2c_block_read) {
 412             if (s->smb_index >= PM_SMBUS_MAX_MSG_SIZE) {
 413                 s->smb_index = 0;
 414             }
 415             val = s->smb_data[s->smb_index++];
 416             if (!s->op_done && s->smb_index == s->smb_data0) {
 417                 s->op_done = true;
 418                 s->smb_index = 0;
 419                 s->smb_stat &= ~STS_HOST_BUSY;
 420             }
 421         } else {
 422             val = s->smb_blkdata;
 423         }
 424         break;
 425     case SMBAUXCTL:
 426         val = s->smb_auxctl;
 427         break;
 428     default:
 429         val = 0;
 430         break;
 431     }
 432     SMBUS_DPRINTF("SMB readb port=0x%04" HWADDR_PRIx " val=0x%02x\n",
 433                   addr, val);
 434
 435     if (s->set_irq) {
 436         s->set_irq(s, smb_irq_value(s));
 437     }
 438
 439     return val;
 440 }
 441
 442 static void pm_smbus_reset(PMSMBus *s)
 443 {
 444     s->op_done = true;
 445     s->smb_index = 0;
 446     s->smb_stat = 0;
 447 }
 448
 449 static const MemoryRegionOps pm_smbus_ops = {
 450     .read = smb_ioport_readb,
 451     .write = smb_ioport_writeb,
 452     .valid.min_access_size = 1,
 453     .valid.max_access_size = 1,
 454     .endianness = DEVICE_LITTLE_ENDIAN,
 455 };
 456
 457 bool pm_smbus_vmstate_needed(void)
 458 {
 459     MachineClass *mc = MACHINE_GET_CLASS(qdev_get_machine());
 460
 461     return !mc->smbus_no_migration_support;
 462 }
 463
 464 const VMStateDescription pmsmb_vmstate = {
 465     .name = "pmsmb",
 466     .version_id = 1,
 467     .minimum_version_id = 1,
 468     .fields = (VMStateField[]) {
 469         VMSTATE_UINT8(smb_stat, PMSMBus),
 470         VMSTATE_UINT8(smb_ctl, PMSMBus),
 471         VMSTATE_UINT8(smb_cmd, PMSMBus),
 472         VMSTATE_UINT8(smb_addr, PMSMBus),
 473         VMSTATE_UINT8(smb_data0, PMSMBus),
 474         VMSTATE_UINT8(smb_data1, PMSMBus),
 475         VMSTATE_UINT32(smb_index, PMSMBus),
 476         VMSTATE_UINT8_ARRAY(smb_data, PMSMBus, PM_SMBUS_MAX_MSG_SIZE),
 477         VMSTATE_UINT8(smb_auxctl, PMSMBus),
 478         VMSTATE_UINT8(smb_blkdata, PMSMBus),
 479         VMSTATE_BOOL(i2c_enable, PMSMBus),
 480         VMSTATE_BOOL(op_done, PMSMBus),
 481         VMSTATE_BOOL(in_i2c_block_read, PMSMBus),
 482         VMSTATE_BOOL(start_transaction_on_status_read, PMSMBus),
 483         VMSTATE_END_OF_LIST()
 484     }
 485 };
 486
 487 void pm_smbus_init(DeviceState *parent, PMSMBus *smb, bool force_aux_blk)
 488 {
 489     smb->op_done = true;
 490     smb->reset = pm_smbus_reset;
 491     smb->smbus = i2c_init_bus(parent, "i2c");
 492     if (force_aux_blk) {
 493         smb->smb_auxctl |= AUX_BLK;
 494     }
 495     memory_region_init_io(&smb->io, OBJECT(parent), &pm_smbus_ops, smb,
 496                           "pm-smbus", 64);
 497 }