drivers/i2c/busses/i2c-sis630.c

   1 /*
   2     Copyright (c) 2002,2003 Alexander Malysh <amalysh@web.de>
   3
   4     This program is free software; you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation; either version 2 of the License, or
   7     (at your option) any later version.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License
  15     along with this program; if not, write to the Free Software
  16     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17 */
  18
  19 /*
  20    Changes:
  21    24.08.2002
  22         Fixed the typo in sis630_access (Thanks to Mark M. Hoffman)
  23         Changed sis630_transaction.(Thanks to Mark M. Hoffman)
  24    18.09.2002
  25         Added SIS730 as supported.
  26    21.09.2002
  27         Added high_clock module option.If this option is set
  28         used Host Master Clock 56KHz (default 14KHz).For now we save old Host
  29         Master Clock and after transaction completed restore (otherwise
  30         it's confuse BIOS and hung Machine).
  31    24.09.2002
  32         Fixed typo in sis630_access
  33         Fixed logical error by restoring of Host Master Clock
  34    31.07.2003
  35         Added block data read/write support.
  36 */
  37
  38 /*
  39    Status: beta
  40
  41    Supports:
  42         SIS 630
  43         SIS 730
  44
  45    Note: we assume there can only be one device, with one SMBus interface.
  46 */
  47
  48 #include <linux/kernel.h>
  49 #include <linux/module.h>
  50 #include <linux/delay.h>
  51 #include <linux/pci.h>
  52 #include <linux/ioport.h>
  53 #include <linux/init.h>
  54 #include <linux/i2c.h>
  55 #include <linux/acpi.h>
  56 #include <linux/io.h>
  57
  58 /* SIS630 SMBus registers */
  59 #define SMB_STS                 0x80    /* status */
  60 #define SMB_EN                  0x81    /* status enable */
  61 #define SMB_CNT                 0x82
  62 #define SMBHOST_CNT             0x83
  63 #define SMB_ADDR                0x84
  64 #define SMB_CMD                 0x85
  65 #define SMB_PCOUNT              0x86    /* processed count */
  66 #define SMB_COUNT               0x87
  67 #define SMB_BYTE                0x88    /* ~0x8F data byte field */
  68 #define SMBDEV_ADDR             0x90
  69 #define SMB_DB0                 0x91
  70 #define SMB_DB1                 0x92
  71 #define SMB_SAA                 0x93
  72
  73 /* register count for request_region */
  74 #define SIS630_SMB_IOREGION     20
  75
  76 /* PCI address constants */
  77 /* acpi base address register  */
  78 #define SIS630_ACPI_BASE_REG    0x74
  79 /* bios control register */
  80 #define SIS630_BIOS_CTL_REG     0x40
  81
  82 /* Other settings */
  83 #define MAX_TIMEOUT             500
  84
  85 /* SIS630 constants */
  86 #define SIS630_QUICK            0x00
  87 #define SIS630_BYTE             0x01
  88 #define SIS630_BYTE_DATA        0x02
  89 #define SIS630_WORD_DATA        0x03
  90 #define SIS630_PCALL            0x04
  91 #define SIS630_BLOCK_DATA       0x05
  92
  93 static struct pci_driver sis630_driver;
  94
  95 /* insmod parameters */
  96 static bool high_clock;
  97 static bool 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;
 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 -EBUSY;
 136                 } else {
 137                         dev_dbg(&adap->dev, "Successful!\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 = -ETIMEDOUT;
 179         }
 180
 181         if (temp & 0x02) {
 182                 dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
 183                 result = -ENXIO;
 184         }
 185
 186         if (temp & 0x04) {
 187                 dev_err(&adap->dev, "Bus collision!\n");
 188                 result = -EIO;
 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                                 rc = sis630_transaction_start(adap,
 252                                                 SIS630_BLOCK_DATA, &oldclock);
 253                                 if (rc)
 254                                         return rc;
 255                         }
 256                         else if ((i-1)%8 == 7 || i==len) {
 257                                 dev_dbg(&adap->dev, "trans_wait len=%d i=%d\n",len,i);
 258                                 if (i>8) {
 259                                         dev_dbg(&adap->dev, "clear smbary_sts len=%d i=%d\n",len,i);
 260                                         /*
 261                                            If this is not first transaction,
 262                                            we must clear sticky bit.
 263                                            clear SMBARY_STS
 264                                         */
 265                                         sis630_write(SMB_STS,0x10);
 266                                 }
 267                                 rc = sis630_transaction_wait(adap,
 268                                                 SIS630_BLOCK_DATA);
 269                                 if (rc) {
 270                                         dev_dbg(&adap->dev, "trans_wait failed\n");
 271                                         break;
 272                                 }
 273                         }
 274                 }
 275         }
 276         else {
 277                 /* read request */
 278                 data->block[0] = len = 0;
 279                 rc = sis630_transaction_start(adap,
 280                                 SIS630_BLOCK_DATA, &oldclock);
 281                 if (rc)
 282                         return rc;
 283                 do {
 284                         rc = sis630_transaction_wait(adap, SIS630_BLOCK_DATA);
 285                         if (rc) {
 286                                 dev_dbg(&adap->dev, "trans_wait failed\n");
 287                                 break;
 288                         }
 289                         /* if this first transaction then read byte count */
 290                         if (len == 0)
 291                                 data->block[0] = sis630_read(SMB_COUNT);
 292
 293                         /* just to be sure */
 294                         if (data->block[0] > 32)
 295                                 data->block[0] = 32;
 296
 297                         dev_dbg(&adap->dev, "block data read len=0x%x\n", data->block[0]);
 298
 299                         for (i=0; i < 8 && len < data->block[0]; i++,len++) {
 300                                 dev_dbg(&adap->dev, "read i=%d len=%d\n", i, len);
 301                                 data->block[len+1] = sis630_read(SMB_BYTE+i);
 302                         }
 303
 304                         dev_dbg(&adap->dev, "clear smbary_sts len=%d i=%d\n",len,i);
 305
 306                         /* clear SMBARY_STS */
 307                         sis630_write(SMB_STS,0x10);
 308                 } while(len < data->block[0]);
 309         }
 310
 311         sis630_transaction_end(adap, oldclock);
 312
 313         return rc;
 314 }
 315
 316 /* Return negative errno on error. */
 317 static s32 sis630_access(struct i2c_adapter *adap, u16 addr,
 318                          unsigned short flags, char read_write,
 319                          u8 command, int size, union i2c_smbus_data *data)
 320 {
 321         int status;
 322
 323         switch (size) {
 324                 case I2C_SMBUS_QUICK:
 325                         sis630_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
 326                         size = SIS630_QUICK;
 327                         break;
 328                 case I2C_SMBUS_BYTE:
 329                         sis630_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
 330                         if (read_write == I2C_SMBUS_WRITE)
 331                                 sis630_write(SMB_CMD, command);
 332                         size = SIS630_BYTE;
 333                         break;
 334                 case I2C_SMBUS_BYTE_DATA:
 335                         sis630_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
 336                         sis630_write(SMB_CMD, command);
 337                         if (read_write == I2C_SMBUS_WRITE)
 338                                 sis630_write(SMB_BYTE, data->byte);
 339                         size = SIS630_BYTE_DATA;
 340                         break;
 341                 case I2C_SMBUS_PROC_CALL:
 342                 case I2C_SMBUS_WORD_DATA:
 343                         sis630_write(SMB_ADDR,((addr & 0x7f) << 1) | (read_write & 0x01));
 344                         sis630_write(SMB_CMD, command);
 345                         if (read_write == I2C_SMBUS_WRITE) {
 346                                 sis630_write(SMB_BYTE, data->word & 0xff);
 347                                 sis630_write(SMB_BYTE + 1,(data->word & 0xff00) >> 8);
 348                         }
 349                         size = (size == I2C_SMBUS_PROC_CALL ? SIS630_PCALL : SIS630_WORD_DATA);
 350                         break;
 351                 case I2C_SMBUS_BLOCK_DATA:
 352                         sis630_write(SMB_ADDR,((addr & 0x7f) << 1) | (read_write & 0x01));
 353                         sis630_write(SMB_CMD, command);
 354                         size = SIS630_BLOCK_DATA;
 355                         return sis630_block_data(adap, data, read_write);
 356                 default:
 357                         dev_warn(&adap->dev, "Unsupported transaction %d\n",
 358                                  size);
 359                         return -EOPNOTSUPP;
 360         }
 361
 362         status = sis630_transaction(adap, size);
 363         if (status)
 364                 return status;
 365
 366         if ((size != SIS630_PCALL) &&
 367                 ((read_write == I2C_SMBUS_WRITE) || (size == SIS630_QUICK))) {
 368                 return 0;
 369         }
 370
 371         switch(size) {
 372                 case SIS630_BYTE:
 373                 case SIS630_BYTE_DATA:
 374                         data->byte = sis630_read(SMB_BYTE);
 375                         break;
 376                 case SIS630_PCALL:
 377                 case SIS630_WORD_DATA:
 378                         data->word = sis630_read(SMB_BYTE) + (sis630_read(SMB_BYTE + 1) << 8);
 379                         break;
 380         }
 381
 382         return 0;
 383 }
 384
 385 static u32 sis630_func(struct i2c_adapter *adapter)
 386 {
 387         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA |
 388                 I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_PROC_CALL |
 389                 I2C_FUNC_SMBUS_BLOCK_DATA;
 390 }
 391
 392 static int sis630_setup(struct pci_dev *sis630_dev)
 393 {
 394         unsigned char b;
 395         struct pci_dev *dummy = NULL;
 396         int retval, i;
 397
 398         /* check for supported SiS devices */
 399         for (i=0; supported[i] > 0 ; i++) {
 400                 if ((dummy = pci_get_device(PCI_VENDOR_ID_SI, supported[i], dummy)))
 401                         break; /* found */
 402         }
 403
 404         if (dummy) {
 405                 pci_dev_put(dummy);
 406         }
 407         else if (force) {
 408                 dev_err(&sis630_dev->dev, "WARNING: Can't detect SIS630 compatible device, but "
 409                         "loading because of force option enabled\n");
 410         }
 411         else {
 412                 return -ENODEV;
 413         }
 414
 415         /*
 416            Enable ACPI first , so we can accsess reg 74-75
 417            in acpi io space and read acpi base addr
 418         */
 419         if (pci_read_config_byte(sis630_dev, SIS630_BIOS_CTL_REG,&b)) {
 420                 dev_err(&sis630_dev->dev, "Error: Can't read bios ctl reg\n");
 421                 retval = -ENODEV;
 422                 goto exit;
 423         }
 424         /* if ACPI already enabled , do nothing */
 425         if (!(b & 0x80) &&
 426             pci_write_config_byte(sis630_dev, SIS630_BIOS_CTL_REG, b | 0x80)) {
 427                 dev_err(&sis630_dev->dev, "Error: Can't enable ACPI\n");
 428                 retval = -ENODEV;
 429                 goto exit;
 430         }
 431
 432         /* Determine the ACPI base address */
 433         if (pci_read_config_word(sis630_dev,SIS630_ACPI_BASE_REG,&acpi_base)) {
 434                 dev_err(&sis630_dev->dev, "Error: Can't determine ACPI base address\n");
 435                 retval = -ENODEV;
 436                 goto exit;
 437         }
 438
 439         dev_dbg(&sis630_dev->dev, "ACPI base at 0x%04x\n", acpi_base);
 440
 441         retval = acpi_check_region(acpi_base + SMB_STS, SIS630_SMB_IOREGION,
 442                                    sis630_driver.name);
 443         if (retval)
 444                 goto exit;
 445
 446         /* Everything is happy, let's grab the memory and set things up. */
 447         if (!request_region(acpi_base + SMB_STS, SIS630_SMB_IOREGION,
 448                             sis630_driver.name)) {
 449                 dev_err(&sis630_dev->dev, "SMBus registers 0x%04x-0x%04x already "
 450                         "in use!\n", acpi_base + SMB_STS, acpi_base + SMB_SAA);
 451                 retval = -EBUSY;
 452                 goto exit;
 453         }
 454
 455         retval = 0;
 456
 457 exit:
 458         if (retval)
 459                 acpi_base = 0;
 460         return retval;
 461 }
 462
 463
 464 static const struct i2c_algorithm smbus_algorithm = {
 465         .smbus_xfer     = sis630_access,
 466         .functionality  = sis630_func,
 467 };
 468
 469 static struct i2c_adapter sis630_adapter = {
 470         .owner          = THIS_MODULE,
 471         .class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
 472         .algo           = &smbus_algorithm,
 473 };
 474
 475 static DEFINE_PCI_DEVICE_TABLE(sis630_ids) = {
 476         { PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_503) },
 477         { PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_LPC) },
 478         { 0, }
 479 };
 480
 481 MODULE_DEVICE_TABLE (pci, sis630_ids);
 482
 483 static int sis630_probe(struct pci_dev *dev, const struct pci_device_id *id)
 484 {
 485         if (sis630_setup(dev)) {
 486                 dev_err(&dev->dev, "SIS630 comp. bus not detected, module not inserted.\n");
 487                 return -ENODEV;
 488         }
 489
 490         /* set up the sysfs linkage to our parent device */
 491         sis630_adapter.dev.parent = &dev->dev;
 492
 493         snprintf(sis630_adapter.name, sizeof(sis630_adapter.name),
 494                  "SMBus SIS630 adapter at %04x", acpi_base + SMB_STS);
 495
 496         return i2c_add_adapter(&sis630_adapter);
 497 }
 498
 499 static void sis630_remove(struct pci_dev *dev)
 500 {
 501         if (acpi_base) {
 502                 i2c_del_adapter(&sis630_adapter);
 503                 release_region(acpi_base + SMB_STS, SIS630_SMB_IOREGION);
 504                 acpi_base = 0;
 505         }
 506 }
 507
 508
 509 static struct pci_driver sis630_driver = {
 510         .name           = "sis630_smbus",
 511         .id_table       = sis630_ids,
 512         .probe          = sis630_probe,
 513         .remove         = sis630_remove,
 514 };
 515
 516 module_pci_driver(sis630_driver);
 517
 518 MODULE_LICENSE("GPL");
 519 MODULE_AUTHOR("Alexander Malysh <amalysh@web.de>");
 520 MODULE_DESCRIPTION("SIS630 SMBus driver");