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