qemu/hw/i2c/pm_smbus.c
<<
>>
Prefs
   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
  21#include "qemu/osdep.h"
  22#include "hw/boards.h"
  23#include "hw/i2c/pm_smbus.h"
  24#include "hw/i2c/smbus_master.h"
  25#include "migration/vmstate.h"
  26
  27#define SMBHSTSTS       0x00
  28#define SMBHSTCNT       0x02
  29#define SMBHSTCMD       0x03
  30#define SMBHSTADD       0x04
  31#define SMBHSTDAT0      0x05
  32#define SMBHSTDAT1      0x06
  33#define SMBBLKDAT       0x07
  34#define SMBAUXCTL       0x0d
  35
  36#define STS_HOST_BUSY   (1 << 0)
  37#define STS_INTR        (1 << 1)
  38#define STS_DEV_ERR     (1 << 2)
  39#define STS_BUS_ERR     (1 << 3)
  40#define STS_FAILED      (1 << 4)
  41#define STS_SMBALERT    (1 << 5)
  42#define STS_INUSE_STS   (1 << 6)
  43#define STS_BYTE_DONE   (1 << 7)
  44/* Signs of successfully transaction end :
  45*  ByteDoneStatus = 1 (STS_BYTE_DONE) and INTR = 1 (STS_INTR )
  46*/
  47
  48#define CTL_INTREN      (1 << 0)
  49#define CTL_KILL        (1 << 1)
  50#define CTL_LAST_BYTE   (1 << 5)
  51#define CTL_START       (1 << 6)
  52#define CTL_PEC_EN      (1 << 7)
  53#define CTL_RETURN_MASK 0x1f
  54
  55#define PROT_QUICK          0
  56#define PROT_BYTE           1
  57#define PROT_BYTE_DATA      2
  58#define PROT_WORD_DATA      3
  59#define PROT_PROC_CALL      4
  60#define PROT_BLOCK_DATA     5
  61#define PROT_I2C_BLOCK_READ 6
  62
  63#define AUX_PEC       (1 << 0)
  64#define AUX_BLK       (1 << 1)
  65#define AUX_MASK      0x3
  66
  67/*#define DEBUG*/
  68
  69#ifdef DEBUG
  70# define SMBUS_DPRINTF(format, ...)     printf(format, ## __VA_ARGS__)
  71#else
  72# define SMBUS_DPRINTF(format, ...)     do { } while (0)
  73#endif
  74
  75
  76static void smb_transaction(PMSMBus *s)
  77{
  78    uint8_t prot = (s->smb_ctl >> 2) & 0x07;
  79    uint8_t read = s->smb_addr & 0x01;
  80    uint8_t cmd = s->smb_cmd;
  81    uint8_t addr = s->smb_addr >> 1;
  82    I2CBus *bus = s->smbus;
  83    int ret;
  84
  85    SMBUS_DPRINTF("SMBus trans addr=0x%02x prot=0x%02x\n", addr, prot);
  86    /* Transaction isn't exec if STS_DEV_ERR bit set */
  87    if ((s->smb_stat & STS_DEV_ERR) != 0)  {
  88        goto error;
  89    }
  90
  91    switch(prot) {
  92    case PROT_QUICK:
  93        ret = smbus_quick_command(bus, addr, read);
  94        goto done;
  95    case PROT_BYTE:
  96        if (read) {
  97            ret = smbus_receive_byte(bus, addr);
  98            goto data8;
  99        } else {
 100            ret = smbus_send_byte(bus, addr, cmd);
 101            goto done;
 102        }
 103    case PROT_BYTE_DATA:
 104        if (read) {
 105            ret = smbus_read_byte(bus, addr, cmd);
 106            goto data8;
 107        } else {
 108            ret = smbus_write_byte(bus, addr, cmd, s->smb_data0);
 109            goto done;
 110        }
 111        break;
 112    case PROT_WORD_DATA:
 113        if (read) {
 114            ret = smbus_read_word(bus, addr, cmd);
 115            goto data16;
 116        } else {
 117            ret = smbus_write_word(bus, addr, cmd,
 118                                   (s->smb_data1 << 8) | s->smb_data0);
 119            goto done;
 120        }
 121        break;
 122    case PROT_I2C_BLOCK_READ:
 123        /* According to the Linux i2c-i801 driver:
 124         *   NB: page 240 of ICH5 datasheet shows that the R/#W
 125         *   bit should be cleared here, even when reading.
 126         *   However if SPD Write Disable is set (Lynx Point and later),
 127         *   the read will fail if we don't set the R/#W bit.
 128         * So at least Linux may or may not set the read bit here.
 129         * So just ignore the read bit for this command.
 130         */
 131        if (i2c_start_transfer(bus, addr, 0)) {
 132            goto error;
 133        }
 134        ret = i2c_send(bus, s->smb_data1);
 135        if (ret) {
 136            goto error;
 137        }
 138        if (i2c_start_transfer(bus, addr, 1)) {
 139            goto error;
 140        }
 141        s->in_i2c_block_read = true;
 142        s->smb_blkdata = i2c_recv(s->smbus);
 143        s->op_done = false;
 144        s->smb_stat |= STS_HOST_BUSY | STS_BYTE_DONE;
 145        goto out;
 146
 147    case PROT_BLOCK_DATA:
 148        if (read) {
 149            ret = smbus_read_block(bus, addr, cmd, s->smb_data,
 150                                   sizeof(s->smb_data), !s->i2c_enable,
 151                                   !s->i2c_enable);
 152            if (ret < 0) {
 153                goto error;
 154            }
 155            s->smb_index = 0;
 156            s->op_done = false;
 157            if (s->smb_auxctl & AUX_BLK) {
 158                s->smb_stat |= STS_INTR;
 159            } else {
 160                s->smb_blkdata = s->smb_data[0];
 161                s->smb_stat |= STS_HOST_BUSY | STS_BYTE_DONE;
 162            }
 163            s->smb_data0 = ret;
 164            goto out;
 165        } else {
 166            if (s->smb_auxctl & AUX_BLK) {
 167                if (s->smb_index != s->smb_data0) {
 168                    s->smb_index = 0;
 169                    goto error;
 170                }
 171                /* Data is already all written to the queue, just do
 172                   the operation. */
 173                s->smb_index = 0;
 174                ret = smbus_write_block(bus, addr, cmd, s->smb_data,
 175                                        s->smb_data0, !s->i2c_enable);
 176                if (ret < 0) {
 177                    goto error;
 178                }
 179                s->op_done = true;
 180                s->smb_stat |= STS_INTR;
 181                s->smb_stat &= ~STS_HOST_BUSY;
 182            } else {
 183                s->op_done = false;
 184                s->smb_stat |= STS_HOST_BUSY | STS_BYTE_DONE;
 185                s->smb_data[0] = s->smb_blkdata;
 186                s->smb_index = 0;
 187                ret = 0;
 188            }
 189            goto out;
 190        }
 191        break;
 192    default:
 193        goto error;
 194    }
 195    abort();
 196
 197data16:
 198    if (ret < 0) {
 199        goto error;
 200    }
 201    s->smb_data1 = ret >> 8;
 202data8:
 203    if (ret < 0) {
 204        goto error;
 205    }
 206    s->smb_data0 = ret;
 207done:
 208    if (ret < 0) {
 209        goto error;
 210    }
 211    s->smb_stat |= STS_INTR;
 212out:
 213    return;
 214
 215error:
 216    s->smb_stat |= STS_DEV_ERR;
 217    return;
 218}
 219
 220static void smb_transaction_start(PMSMBus *s)
 221{
 222    if (s->smb_ctl & CTL_INTREN) {
 223        smb_transaction(s);
 224        s->start_transaction_on_status_read = false;
 225    } else {
 226        /* Do not execute immediately the command; it will be
 227         * executed when guest will read SMB_STAT register.  This
 228         * is to work around a bug in AMIBIOS (that is working
 229         * around another bug in some specific hardware) where
 230         * it waits for STS_HOST_BUSY to be set before waiting
 231         * checking for status.  If STS_HOST_BUSY doesn't get
 232         * set, it gets stuck. */
 233        s->smb_stat |= STS_HOST_BUSY;
 234        s->start_transaction_on_status_read = true;
 235    }
 236}
 237
 238static bool
 239smb_irq_value(PMSMBus *s)
 240{
 241    return ((s->smb_stat & ~STS_HOST_BUSY) != 0) && (s->smb_ctl & CTL_INTREN);
 242}
 243
 244static bool
 245smb_byte_by_byte(PMSMBus *s)
 246{
 247    if (s->op_done) {
 248        return false;
 249    }
 250    if (s->in_i2c_block_read) {
 251        return true;
 252    }
 253    return !(s->smb_auxctl & AUX_BLK);
 254}
 255
 256static void smb_ioport_writeb(void *opaque, hwaddr addr, uint64_t val,
 257                              unsigned width)
 258{
 259    PMSMBus *s = opaque;
 260    uint8_t clear_byte_done;
 261
 262    SMBUS_DPRINTF("SMB writeb port=0x%04" HWADDR_PRIx
 263                  " val=0x%02" PRIx64 "\n", addr, val);
 264    switch(addr) {
 265    case SMBHSTSTS:
 266        clear_byte_done = s->smb_stat & val & STS_BYTE_DONE;
 267        s->smb_stat &= ~(val & ~STS_HOST_BUSY);
 268        if (clear_byte_done && smb_byte_by_byte(s)) {
 269            uint8_t read = s->smb_addr & 0x01;
 270
 271            if (s->in_i2c_block_read) {
 272                /* See comment below PROT_I2C_BLOCK_READ above. */
 273                read = 1;
 274            }
 275
 276            s->smb_index++;
 277            if (s->smb_index >= PM_SMBUS_MAX_MSG_SIZE) {
 278                s->smb_index = 0;
 279            }
 280            if (!read && s->smb_index == s->smb_data0) {
 281                uint8_t prot = (s->smb_ctl >> 2) & 0x07;
 282                uint8_t cmd = s->smb_cmd;
 283                uint8_t addr = s->smb_addr >> 1;
 284                int ret;
 285
 286                if (prot == PROT_I2C_BLOCK_READ) {
 287                    s->smb_stat |= STS_DEV_ERR;
 288                    goto out;
 289                }
 290
 291                ret = smbus_write_block(s->smbus, addr, cmd, s->smb_data,
 292                                        s->smb_data0, !s->i2c_enable);
 293                if (ret < 0) {
 294                    s->smb_stat |= STS_DEV_ERR;
 295                    goto out;
 296                }
 297                s->op_done = true;
 298                s->smb_stat |= STS_INTR;
 299                s->smb_stat &= ~STS_HOST_BUSY;
 300            } else if (!read) {
 301                s->smb_data[s->smb_index] = s->smb_blkdata;
 302                s->smb_stat |= STS_BYTE_DONE;
 303            } else if (s->smb_ctl & CTL_LAST_BYTE) {
 304                s->op_done = true;
 305                if (s->in_i2c_block_read) {
 306                    s->in_i2c_block_read = false;
 307                    s->smb_blkdata = i2c_recv(s->smbus);
 308                    i2c_nack(s->smbus);
 309                    i2c_end_transfer(s->smbus);
 310                } else {
 311                    s->smb_blkdata = s->smb_data[s->smb_index];
 312                }
 313                s->smb_index = 0;
 314                s->smb_stat |= STS_INTR;
 315                s->smb_stat &= ~STS_HOST_BUSY;
 316            } else {
 317                if (s->in_i2c_block_read) {
 318                    s->smb_blkdata = i2c_recv(s->smbus);
 319                } else {
 320                    s->smb_blkdata = s->smb_data[s->smb_index];
 321                }
 322                s->smb_stat |= STS_BYTE_DONE;
 323            }
 324        }
 325        break;
 326    case SMBHSTCNT:
 327        s->smb_ctl = val & ~CTL_START; /* CTL_START always reads 0 */
 328        if (val & CTL_START) {
 329            if (!s->op_done) {
 330                s->smb_index = 0;
 331                s->op_done = true;
 332                if (s->in_i2c_block_read) {
 333                    s->in_i2c_block_read = false;
 334                    i2c_end_transfer(s->smbus);
 335                }
 336            }
 337            smb_transaction_start(s);
 338        }
 339        if (s->smb_ctl & CTL_KILL) {
 340            s->op_done = true;
 341            s->smb_index = 0;
 342            s->smb_stat |= STS_FAILED;
 343            s->smb_stat &= ~STS_HOST_BUSY;
 344        }
 345        break;
 346    case SMBHSTCMD:
 347        s->smb_cmd = val;
 348        break;
 349    case SMBHSTADD:
 350        s->smb_addr = val;
 351        break;
 352    case SMBHSTDAT0:
 353        s->smb_data0 = val;
 354        break;
 355    case SMBHSTDAT1:
 356        s->smb_data1 = val;
 357        break;
 358    case SMBBLKDAT:
 359        if (s->smb_index >= PM_SMBUS_MAX_MSG_SIZE) {
 360            s->smb_index = 0;
 361        }
 362        if (s->smb_auxctl & AUX_BLK) {
 363            s->smb_data[s->smb_index++] = val;
 364        } else {
 365            s->smb_blkdata = val;
 366        }
 367        break;
 368    case SMBAUXCTL:
 369        s->smb_auxctl = val & AUX_MASK;
 370        break;
 371    default:
 372        break;
 373    }
 374
 375 out:
 376    if (s->set_irq) {
 377        s->set_irq(s, smb_irq_value(s));
 378    }
 379}
 380
 381static uint64_t smb_ioport_readb(void *opaque, hwaddr addr, unsigned width)
 382{
 383    PMSMBus *s = opaque;
 384    uint32_t val;
 385
 386    switch(addr) {
 387    case SMBHSTSTS:
 388        val = s->smb_stat;
 389        if (s->start_transaction_on_status_read) {
 390            /* execute command now */
 391            s->start_transaction_on_status_read = false;
 392            s->smb_stat &= ~STS_HOST_BUSY;
 393            smb_transaction(s);
 394        }
 395        break;
 396    case SMBHSTCNT:
 397        val = s->smb_ctl & CTL_RETURN_MASK;
 398        break;
 399    case SMBHSTCMD:
 400        val = s->smb_cmd;
 401        break;
 402    case SMBHSTADD:
 403        val = s->smb_addr;
 404        break;
 405    case SMBHSTDAT0:
 406        val = s->smb_data0;
 407        break;
 408    case SMBHSTDAT1:
 409        val = s->smb_data1;
 410        break;
 411    case SMBBLKDAT:
 412        if (s->smb_auxctl & AUX_BLK && !s->in_i2c_block_read) {
 413            if (s->smb_index >= PM_SMBUS_MAX_MSG_SIZE) {
 414                s->smb_index = 0;
 415            }
 416            val = s->smb_data[s->smb_index++];
 417            if (!s->op_done && s->smb_index == s->smb_data0) {
 418                s->op_done = true;
 419                s->smb_index = 0;
 420                s->smb_stat &= ~STS_HOST_BUSY;
 421            }
 422        } else {
 423            val = s->smb_blkdata;
 424        }
 425        break;
 426    case SMBAUXCTL:
 427        val = s->smb_auxctl;
 428        break;
 429    default:
 430        val = 0;
 431        break;
 432    }
 433    SMBUS_DPRINTF("SMB readb port=0x%04" HWADDR_PRIx " val=0x%02x\n",
 434                  addr, val);
 435
 436    if (s->set_irq) {
 437        s->set_irq(s, smb_irq_value(s));
 438    }
 439
 440    return val;
 441}
 442
 443static void pm_smbus_reset(PMSMBus *s)
 444{
 445    s->op_done = true;
 446    s->smb_index = 0;
 447    s->smb_stat = 0;
 448}
 449
 450static const MemoryRegionOps pm_smbus_ops = {
 451    .read = smb_ioport_readb,
 452    .write = smb_ioport_writeb,
 453    .valid.min_access_size = 1,
 454    .valid.max_access_size = 1,
 455    .endianness = DEVICE_LITTLE_ENDIAN,
 456};
 457
 458bool pm_smbus_vmstate_needed(void)
 459{
 460    MachineClass *mc = MACHINE_GET_CLASS(qdev_get_machine());
 461
 462    return !mc->smbus_no_migration_support;
 463}
 464
 465const VMStateDescription pmsmb_vmstate = {
 466    .name = "pmsmb",
 467    .version_id = 1,
 468    .minimum_version_id = 1,
 469    .fields = (VMStateField[]) {
 470        VMSTATE_UINT8(smb_stat, PMSMBus),
 471        VMSTATE_UINT8(smb_ctl, PMSMBus),
 472        VMSTATE_UINT8(smb_cmd, PMSMBus),
 473        VMSTATE_UINT8(smb_addr, PMSMBus),
 474        VMSTATE_UINT8(smb_data0, PMSMBus),
 475        VMSTATE_UINT8(smb_data1, PMSMBus),
 476        VMSTATE_UINT32(smb_index, PMSMBus),
 477        VMSTATE_UINT8_ARRAY(smb_data, PMSMBus, PM_SMBUS_MAX_MSG_SIZE),
 478        VMSTATE_UINT8(smb_auxctl, PMSMBus),
 479        VMSTATE_UINT8(smb_blkdata, PMSMBus),
 480        VMSTATE_BOOL(i2c_enable, PMSMBus),
 481        VMSTATE_BOOL(op_done, PMSMBus),
 482        VMSTATE_BOOL(in_i2c_block_read, PMSMBus),
 483        VMSTATE_BOOL(start_transaction_on_status_read, PMSMBus),
 484        VMSTATE_END_OF_LIST()
 485    }
 486};
 487
 488void pm_smbus_init(DeviceState *parent, PMSMBus *smb, bool force_aux_blk)
 489{
 490    smb->op_done = true;
 491    smb->reset = pm_smbus_reset;
 492    smb->smbus = i2c_init_bus(parent, "i2c");
 493    if (force_aux_blk) {
 494        smb->smb_auxctl |= AUX_BLK;
 495    }
 496    memory_region_init_io(&smb->io, OBJECT(parent), &pm_smbus_ops, smb,
 497                          "pm-smbus", 64);
 498}
 499