drivers/i2c/busses/i2c-sis630.c

   1 /*
   2     i2c-sis630.c - Part of lm_sensors, Linux kernel modules for hardware
   3               monitoring
   4
   5     Copyright (c) 2002,2003 Alexander Malysh <amalysh@web.de>
   6
   7     This program is free software; you can redistribute it and/or modify
   8     it under the terms of the GNU General Public License as published by
   9     the Free Software Foundation; either version 2 of the License, or
  10     (at your option) any later version.
  11
  12     This program is distributed in the hope that it will be useful,
  13     but WITHOUT ANY WARRANTY; without even the implied warranty of
  14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15     GNU General Public License for more details.
  16
  17     You should have received a copy of the GNU General Public License
  18     along with this program; if not, write to the Free Software
  19     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22 /*
  23    Changes:
  24    24.08.2002
  25         Fixed the typo in sis630_access (Thanks to Mark M. Hoffman)
  26         Changed sis630_transaction.(Thanks to Mark M. Hoffman)
  27    18.09.2002
  28         Added SIS730 as supported.
  29    21.09.2002
  30         Added high_clock module option.If this option is set
  31         used Host Master Clock 56KHz (default 14KHz).For now we save old Host
  32         Master Clock and after transaction completed restore (otherwise
  33         it's confuse BIOS and hung Machine).
  34    24.09.2002
  35         Fixed typo in sis630_access
  36         Fixed logical error by restoring of Host Master Clock
  37    31.07.2003
  38         Added block data read/write support.
  39 */
  40
  41 /*
  42    Status: beta
  43
  44    Supports:
  45         SIS 630
  46         SIS 730
  47
  48    Note: we assume there can only be one device, with one SMBus interface.
  49 */
  50
  51 #include <linux/kernel.h>
  52 #include <linux/module.h>
  53 #include <linux/delay.h>
  54 #include <linux/pci.h>
  55 #include <linux/ioport.h>
  56 #include <linux/init.h>
  57 #include <linux/i2c.h>
  58 #include <asm/io.h>
  59
  60 /* SIS630 SMBus registers */
  61 #define SMB_STS                 0x80    /* status */
  62 #define SMB_EN                  0x81    /* status enable */
  63 #define SMB_CNT                 0x82
  64 #define SMBHOST_CNT             0x83
  65 #define SMB_ADDR                0x84
  66 #define SMB_CMD                 0x85
  67 #define SMB_PCOUNT              0x86    /* processed count */
  68 #define SMB_COUNT               0x87
  69 #define SMB_BYTE                0x88    /* ~0x8F data byte field */
  70 #define SMBDEV_ADDR             0x90
  71 #define SMB_DB0                 0x91
  72 #define SMB_DB1                 0x92
  73 #define SMB_SAA                 0x93
  74
  75 /* register count for request_region */
  76 #define SIS630_SMB_IOREGION     20
  77
  78 /* PCI address constants */
  79 /* acpi base address register  */
  80 #define SIS630_ACPI_BASE_REG    0x74
  81 /* bios control register */
  82 #define SIS630_BIOS_CTL_REG     0x40
  83
  84 /* Other settings */
  85 #define MAX_TIMEOUT             500
  86
  87 /* SIS630 constants */
  88 #define SIS630_QUICK            0x00
  89 #define SIS630_BYTE             0x01
  90 #define SIS630_BYTE_DATA        0x02
  91 #define SIS630_WORD_DATA        0x03
  92 #define SIS630_PCALL            0x04
  93 #define SIS630_BLOCK_DATA       0x05
  94
  95 /* insmod parameters */
  96 static int high_clock;
  97 static int force;
  98 module_param(high_clock, bool, 0);
  99 MODULE_PARM_DESC(high_clock, "Set Host Master Clock to 56KHz (default 14KHz).");
 100 module_param(force, bool, 0);
 101 MODULE_PARM_DESC(force, "Forcibly enable the SIS630. DANGEROUS!");
 102
 103 /* acpi base address */
 104 static unsigned short acpi_base = 0;
 105
 106 /* supported chips */
 107 static int supported[] = {
 108         PCI_DEVICE_ID_SI_630,
 109         PCI_DEVICE_ID_SI_730,
 110         0 /* terminates the list */
 111 };
 112
 113 static inline u8 sis630_read(u8 reg)
 114 {
 115         return inb(acpi_base + reg);
 116 }
 117
 118 static inline void sis630_write(u8 reg, u8 data)
 119 {
 120         outb(data, acpi_base + reg);
 121 }
 122
 123 static int sis630_transaction_start(struct i2c_adapter *adap, int size, u8 *oldclock)
 124 {
 125         int temp;
 126
 127         /* Make sure the SMBus host is ready to start transmitting. */
 128         if ((temp = sis630_read(SMB_CNT) & 0x03) != 0x00) {
 129                 dev_dbg(&adap->dev, "SMBus busy (%02x).Resetting...\n",temp);
 130                 /* kill smbus transaction */
 131                 sis630_write(SMBHOST_CNT, 0x20);
 132
 133                 if ((temp = sis630_read(SMB_CNT) & 0x03) != 0x00) {
 134                         dev_dbg(&adap->dev, "Failed! (%02x)\n", temp);
 135                         return -1;
 136                 } else {
 137                         dev_dbg(&adap->dev, "Successfull!\n");
 138                 }
 139         }
 140
 141         /* save old clock, so we can prevent machine for hung */
 142         *oldclock = sis630_read(SMB_CNT);
 143
 144         dev_dbg(&adap->dev, "saved clock 0x%02x\n", *oldclock);
 145
 146         /* disable timeout interrupt , set Host Master Clock to 56KHz if requested */
 147         if (high_clock)
 148                 sis630_write(SMB_CNT, 0x20);
 149         else
 150                 sis630_write(SMB_CNT, (*oldclock & ~0x40));
 151
 152         /* clear all sticky bits */
 153         temp = sis630_read(SMB_STS);
 154         sis630_write(SMB_STS, temp & 0x1e);
 155
 156         /* start the transaction by setting bit 4 and size */
 157         sis630_write(SMBHOST_CNT,0x10 | (size & 0x07));
 158
 159         return 0;
 160 }
 161
 162 static int sis630_transaction_wait(struct i2c_adapter *adap, int size)
 163 {
 164         int temp, result = 0, timeout = 0;
 165
 166         /* We will always wait for a fraction of a second! */
 167         do {
 168                 msleep(1);
 169                 temp = sis630_read(SMB_STS);
 170                 /* check if block transmitted */
 171                 if (size == SIS630_BLOCK_DATA && (temp & 0x10))
 172                         break;
 173         } while (!(temp & 0x0e) && (timeout++ < MAX_TIMEOUT));
 174
 175         /* If the SMBus is still busy, we give up */
 176         if (timeout >= MAX_TIMEOUT) {
 177                 dev_dbg(&adap->dev, "SMBus Timeout!\n");
 178                 result = -1;
 179         }
 180
 181         if (temp & 0x02) {
 182                 dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
 183                 result = -1;
 184         }
 185
 186         if (temp & 0x04) {
 187                 dev_err(&adap->dev, "Bus collision!\n");
 188                 result = -1;
 189                 /*
 190                   TBD: Datasheet say:
 191                   the software should clear this bit and restart SMBUS operation.
 192                   Should we do it or user start request again?
 193                 */
 194         }
 195
 196         return result;
 197 }
 198
 199 static void sis630_transaction_end(struct i2c_adapter *adap, u8 oldclock)
 200 {
 201         int temp = 0;
 202
 203         /* clear all status "sticky" bits */
 204         sis630_write(SMB_STS, temp);
 205
 206         dev_dbg(&adap->dev, "SMB_CNT before clock restore 0x%02x\n", sis630_read(SMB_CNT));
 207
 208         /*
 209          * restore old Host Master Clock if high_clock is set
 210          * and oldclock was not 56KHz
 211          */
 212         if (high_clock && !(oldclock & 0x20))
 213                 sis630_write(SMB_CNT,(sis630_read(SMB_CNT) & ~0x20));
 214
 215         dev_dbg(&adap->dev, "SMB_CNT after clock restore 0x%02x\n", sis630_read(SMB_CNT));
 216 }
 217
 218 static int sis630_transaction(struct i2c_adapter *adap, int size)
 219 {
 220         int result = 0;
 221         u8 oldclock = 0;
 222
 223         result = sis630_transaction_start(adap, size, &oldclock);
 224         if (!result) {
 225                 result = sis630_transaction_wait(adap, size);
 226                 sis630_transaction_end(adap, oldclock);
 227         }
 228
 229         return result;
 230 }
 231
 232 static int sis630_block_data(struct i2c_adapter *adap, union i2c_smbus_data *data, int read_write)
 233 {
 234         int i, len = 0, rc = 0;
 235         u8 oldclock = 0;
 236
 237         if (read_write == I2C_SMBUS_WRITE) {
 238                 len = data->block[0];
 239                 if (len < 0)
 240                         len = 0;
 241                 else if (len > 32)
 242                         len = 32;
 243                 sis630_write(SMB_COUNT, len);
 244                 for (i=1; i <= len; i++) {
 245                         dev_dbg(&adap->dev, "set data 0x%02x\n", data->block[i]);
 246                         /* set data */
 247                         sis630_write(SMB_BYTE+(i-1)%8, data->block[i]);
 248                         if (i==8 || (len<8 && i==len)) {
 249                                 dev_dbg(&adap->dev, "start trans len=%d i=%d\n",len ,i);
 250                                 /* first transaction */
 251                                 if (sis630_transaction_start(adap, SIS630_BLOCK_DATA, &oldclock))
 252                                         return -1;
 253                         }
 254                         else if ((i-1)%8 == 7 || i==len) {
 255                                 dev_dbg(&adap->dev, "trans_wait len=%d i=%d\n",len,i);
 256                                 if (i>8) {
 257                                         dev_dbg(&adap->dev, "clear smbary_sts len=%d i=%d\n",len,i);
 258                                         /*
 259                                            If this is not first transaction,
 260                                            we must clear sticky bit.
 261                                            clear SMBARY_STS
 262                                         */
 263                                         sis630_write(SMB_STS,0x10);
 264                                 }
 265                                 if (sis630_transaction_wait(adap, SIS630_BLOCK_DATA)) {
 266                                         dev_dbg(&adap->dev, "trans_wait failed\n");
 267                                         rc = -1;
 268                                         break;
 269                                 }
 270                         }
 271                 }
 272         }
 273         else {
 274                 /* read request */
 275                 data->block[0] = len = 0;
 276                 if (sis630_transaction_start(adap, SIS630_BLOCK_DATA, &oldclock)) {
 277                         return -1;
 278                 }
 279                 do {
 280                         if (sis630_transaction_wait(adap, SIS630_BLOCK_DATA)) {
 281                                 dev_dbg(&adap->dev, "trans_wait failed\n");
 282                                 rc = -1;
 283                                 break;
 284                         }
 285                         /* if this first transaction then read byte count */
 286                         if (len == 0)
 287                                 data->block[0] = sis630_read(SMB_COUNT);
 288
 289                         /* just to be sure */
 290                         if (data->block[0] > 32)
 291                                 data->block[0] = 32;
 292
 293                         dev_dbg(&adap->dev, "block data read len=0x%x\n", data->block[0]);
 294
 295                         for (i=0; i < 8 && len < data->block[0]; i++,len++) {
 296                                 dev_dbg(&adap->dev, "read i=%d len=%d\n", i, len);
 297                                 data->block[len+1] = sis630_read(SMB_BYTE+i);
 298                         }
 299
 300                         dev_dbg(&adap->dev, "clear smbary_sts len=%d i=%d\n",len,i);
 301
 302                         /* clear SMBARY_STS */
 303                         sis630_write(SMB_STS,0x10);
 304                 } while(len < data->block[0]);
 305         }
 306
 307         sis630_transaction_end(adap, oldclock);
 308
 309         return rc;
 310 }
 311
 312 /* Return -1 on error. */
 313 static s32 sis630_access(struct i2c_adapter *adap, u16 addr,
 314                          unsigned short flags, char read_write,
 315                          u8 command, int size, union i2c_smbus_data *data)
 316 {
 317         switch (size) {
 318                 case I2C_SMBUS_QUICK:
 319                         sis630_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
 320                         size = SIS630_QUICK;
 321                         break;
 322                 case I2C_SMBUS_BYTE:
 323                         sis630_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
 324                         if (read_write == I2C_SMBUS_WRITE)
 325                                 sis630_write(SMB_CMD, command);
 326                         size = SIS630_BYTE;
 327                         break;
 328                 case I2C_SMBUS_BYTE_DATA:
 329                         sis630_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
 330                         sis630_write(SMB_CMD, command);
 331                         if (read_write == I2C_SMBUS_WRITE)
 332                                 sis630_write(SMB_BYTE, data->byte);
 333                         size = SIS630_BYTE_DATA;
 334                         break;
 335                 case I2C_SMBUS_PROC_CALL:
 336                 case I2C_SMBUS_WORD_DATA:
 337                         sis630_write(SMB_ADDR,((addr & 0x7f) << 1) | (read_write & 0x01));
 338                         sis630_write(SMB_CMD, command);
 339                         if (read_write == I2C_SMBUS_WRITE) {
 340                                 sis630_write(SMB_BYTE, data->word & 0xff);
 341                                 sis630_write(SMB_BYTE + 1,(data->word & 0xff00) >> 8);
 342                         }
 343                         size = (size == I2C_SMBUS_PROC_CALL ? SIS630_PCALL : SIS630_WORD_DATA);
 344                         break;
 345                 case I2C_SMBUS_BLOCK_DATA:
 346                         sis630_write(SMB_ADDR,((addr & 0x7f) << 1) | (read_write & 0x01));
 347                         sis630_write(SMB_CMD, command);
 348                         size = SIS630_BLOCK_DATA;
 349                         return sis630_block_data(adap, data, read_write);
 350                 default:
 351                         printk("Unsupported I2C size\n");
 352                         return -1;
 353                         break;
 354         }
 355
 356         if (sis630_transaction(adap, size))
 357                 return -1;
 358
 359         if ((size != SIS630_PCALL) &&
 360                 ((read_write == I2C_SMBUS_WRITE) || (size == SIS630_QUICK))) {
 361                 return 0;
 362         }
 363
 364         switch(size) {
 365                 case SIS630_BYTE:
 366                 case SIS630_BYTE_DATA:
 367                         data->byte = sis630_read(SMB_BYTE);
 368                         break;
 369                 case SIS630_PCALL:
 370                 case SIS630_WORD_DATA:
 371                         data->word = sis630_read(SMB_BYTE) + (sis630_read(SMB_BYTE + 1) << 8);
 372                         break;
 373                 default:
 374                         return -1;
 375                         break;
 376         }
 377
 378         return 0;
 379 }
 380
 381 static u32 sis630_func(struct i2c_adapter *adapter)
 382 {
 383         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA |
 384                 I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_PROC_CALL |
 385                 I2C_FUNC_SMBUS_BLOCK_DATA;
 386 }
 387
 388 static int sis630_setup(struct pci_dev *sis630_dev)
 389 {
 390         unsigned char b;
 391         struct pci_dev *dummy = NULL;
 392         int retval = -ENODEV, i;
 393
 394         /* check for supported SiS devices */
 395         for (i=0; supported[i] > 0 ; i++) {
 396                 if ((dummy = pci_get_device(PCI_VENDOR_ID_SI, supported[i], dummy)))
 397                         break; /* found */
 398         }
 399
 400         if (dummy) {
 401                 pci_dev_put(dummy);
 402         }
 403         else if (force) {
 404                 dev_err(&sis630_dev->dev, "WARNING: Can't detect SIS630 compatible device, but "
 405                         "loading because of force option enabled\n");
 406         }
 407         else {
 408                 return -ENODEV;
 409         }
 410
 411         /*
 412            Enable ACPI first , so we can accsess reg 74-75
 413            in acpi io space and read acpi base addr
 414         */
 415         if (pci_read_config_byte(sis630_dev, SIS630_BIOS_CTL_REG,&b)) {
 416                 dev_err(&sis630_dev->dev, "Error: Can't read bios ctl reg\n");
 417                 goto exit;
 418         }
 419         /* if ACPI already enabled , do nothing */
 420         if (!(b & 0x80) &&
 421             pci_write_config_byte(sis630_dev, SIS630_BIOS_CTL_REG, b | 0x80)) {
 422                 dev_err(&sis630_dev->dev, "Error: Can't enable ACPI\n");
 423                 goto exit;
 424         }
 425
 426         /* Determine the ACPI base address */
 427         if (pci_read_config_word(sis630_dev,SIS630_ACPI_BASE_REG,&acpi_base)) {
 428                 dev_err(&sis630_dev->dev, "Error: Can't determine ACPI base address\n");
 429                 goto exit;
 430         }
 431
 432         dev_dbg(&sis630_dev->dev, "ACPI base at 0x%04x\n", acpi_base);
 433
 434         /* Everything is happy, let's grab the memory and set things up. */
 435         if (!request_region(acpi_base + SMB_STS, SIS630_SMB_IOREGION, "sis630-smbus")) {
 436                 dev_err(&sis630_dev->dev, "SMBus registers 0x%04x-0x%04x already "
 437                         "in use!\n", acpi_base + SMB_STS, acpi_base + SMB_SAA);
 438                 goto exit;
 439         }
 440
 441         retval = 0;
 442
 443 exit:
 444         if (retval)
 445                 acpi_base = 0;
 446         return retval;
 447 }
 448
 449
 450 static struct i2c_algorithm smbus_algorithm = {
 451         .smbus_xfer     = sis630_access,
 452         .functionality  = sis630_func,
 453 };
 454
 455 static struct i2c_adapter sis630_adapter = {
 456         .owner          = THIS_MODULE,
 457         .class          = I2C_CLASS_HWMON,
 458         .name           = "unset",
 459         .algo           = &smbus_algorithm,
 460 };
 461
 462 static struct pci_device_id sis630_ids[] __devinitdata = {
 463         { PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_503) },
 464         { PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_LPC) },
 465         { 0, }
 466 };
 467
 468 MODULE_DEVICE_TABLE (pci, sis630_ids);
 469
 470 static int __devinit sis630_probe(struct pci_dev *dev, const struct pci_device_id *id)
 471 {
 472         if (sis630_setup(dev)) {
 473                 dev_err(&dev->dev, "SIS630 comp. bus not detected, module not inserted.\n");
 474                 return -ENODEV;
 475         }
 476
 477         /* set up the driverfs linkage to our parent device */
 478         sis630_adapter.dev.parent = &dev->dev;
 479
 480         sprintf(sis630_adapter.name, "SMBus SIS630 adapter at %04x",
 481                 acpi_base + SMB_STS);
 482
 483         return i2c_add_adapter(&sis630_adapter);
 484 }
 485
 486 static void __devexit sis630_remove(struct pci_dev *dev)
 487 {
 488         if (acpi_base) {
 489                 i2c_del_adapter(&sis630_adapter);
 490                 release_region(acpi_base + SMB_STS, SIS630_SMB_IOREGION);
 491                 acpi_base = 0;
 492         }
 493 }
 494
 495
 496 static struct pci_driver sis630_driver = {
 497         .name           = "sis630_smbus",
 498         .id_table       = sis630_ids,
 499         .probe          = sis630_probe,
 500         .remove         = __devexit_p(sis630_remove),
 501 };
 502
 503 static int __init i2c_sis630_init(void)
 504 {
 505         return pci_register_driver(&sis630_driver);
 506 }
 507
 508
 509 static void __exit i2c_sis630_exit(void)
 510 {
 511         pci_unregister_driver(&sis630_driver);
 512 }
 513
 514
 515 MODULE_LICENSE("GPL");
 516 MODULE_AUTHOR("Alexander Malysh <amalysh@web.de>");
 517 MODULE_DESCRIPTION("SIS630 SMBus driver");
 518
 519 module_init(i2c_sis630_init);
 520 module_exit(i2c_sis630_exit);