qemu/hw/i2c/pm_smbus.c
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   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
  75static 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
 196data16:
 197    if (ret < 0) {
 198        goto error;
 199    }
 200    s->smb_data1 = ret >> 8;
 201data8:
 202    if (ret < 0) {
 203        goto error;
 204    }
 205    s->smb_data0 = ret;
 206done:
 207    if (ret < 0) {
 208        goto error;
 209    }
 210    s->smb_stat |= STS_INTR;
 211out:
 212    return;
 213
 214error:
 215    s->smb_stat |= STS_DEV_ERR;
 216    return;
 217}
 218
 219static 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
 237static bool
 238smb_irq_value(PMSMBus *s)
 239{
 240    return ((s->smb_stat & ~STS_HOST_BUSY) != 0) && (s->smb_ctl & CTL_INTREN);
 241}
 242
 243static bool
 244smb_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
 255static 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
 380static 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
 442static void pm_smbus_reset(PMSMBus *s)
 443{
 444    s->op_done = true;
 445    s->smb_index = 0;
 446    s->smb_stat = 0;
 447}
 448
 449static 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
 457bool 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
 464const 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
 487void 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}
 498