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    Status: beta
  21
  22    Supports:
  23         SIS 630
  24         SIS 730
  25         SIS 964
  26
  27    Notable differences between chips:
  28         +------------------------+--------------------+-------------------+
  29         |                        |     SIS630/730     |      SIS964       |
  30         +------------------------+--------------------+-------------------+
  31         | Clock                  | 14kHz/56kHz        | 55.56kHz/27.78kHz |
  32         | SMBus registers offset | 0x80               | 0xE0              |
  33         | SMB_CNT                | Bit 1 = Slave Busy | Bit 1 = Bus probe |
  34         |         (not used yet) | Bit 3 is reserved  | Bit 3 = Last byte |
  35         | SMB_PCOUNT             | Offset + 0x06      | Offset + 0x14     |
  36         | SMB_COUNT              | 4:0 bits           | 5:0 bits          |
  37         +------------------------+--------------------+-------------------+
  38         (Other differences don't affect the functions provided by the driver)
  39
  40    Note: we assume there can only be one device, with one SMBus interface.
  41 */
  42
  43 #include <linux/kernel.h>
  44 #include <linux/module.h>
  45 #include <linux/delay.h>
  46 #include <linux/pci.h>
  47 #include <linux/ioport.h>
  48 #include <linux/init.h>
  49 #include <linux/i2c.h>
  50 #include <linux/acpi.h>
  51 #include <linux/io.h>
  52
  53 /* SIS964 id is defined here as we are the only file using it */
  54 #define PCI_DEVICE_ID_SI_964    0x0964
  55
  56 /* SIS630/730/964 SMBus registers */
  57 #define SMB_STS                 0x00    /* status */
  58 #define SMB_CNT                 0x02    /* control */
  59 #define SMBHOST_CNT             0x03    /* host control */
  60 #define SMB_ADDR                0x04    /* address */
  61 #define SMB_CMD                 0x05    /* command */
  62 #define SMB_COUNT               0x07    /* byte count */
  63 #define SMB_BYTE                0x08    /* ~0x8F data byte field */
  64
  65 /* SMB_STS register */
  66 #define BYTE_DONE_STS           0x10    /* Byte Done Status / Block Array */
  67 #define SMBCOL_STS              0x04    /* Collision */
  68 #define SMBERR_STS              0x02    /* Device error */
  69
  70 /* SMB_CNT register */
  71 #define MSTO_EN                 0x40    /* Host Master Timeout Enable */
  72 #define SMBCLK_SEL              0x20    /* Host master clock selection */
  73 #define SMB_PROBE               0x02    /* Bus Probe/Slave busy */
  74 #define SMB_HOSTBUSY            0x01    /* Host Busy */
  75
  76 /* SMBHOST_CNT register */
  77 #define SMB_KILL                0x20    /* Kill */
  78 #define SMB_START               0x10    /* Start */
  79
  80 /* register count for request_region
  81  * As we don't use SMB_PCOUNT, 20 is ok for SiS630 and SiS964
  82  */
  83 #define SIS630_SMB_IOREGION     20
  84
  85 /* PCI address constants */
  86 /* acpi base address register  */
  87 #define SIS630_ACPI_BASE_REG    0x74
  88 /* bios control register */
  89 #define SIS630_BIOS_CTL_REG     0x40
  90
  91 /* Other settings */
  92 #define MAX_TIMEOUT             500
  93
  94 /* SIS630 constants */
  95 #define SIS630_QUICK            0x00
  96 #define SIS630_BYTE             0x01
  97 #define SIS630_BYTE_DATA        0x02
  98 #define SIS630_WORD_DATA        0x03
  99 #define SIS630_PCALL            0x04
 100 #define SIS630_BLOCK_DATA       0x05
 101
 102 static struct pci_driver sis630_driver;
 103
 104 /* insmod parameters */
 105 static bool high_clock;
 106 static bool force;
 107 module_param(high_clock, bool, 0);
 108 MODULE_PARM_DESC(high_clock,
 109         "Set Host Master Clock to 56KHz (default 14KHz) (SIS630/730 only).");
 110 module_param(force, bool, 0);
 111 MODULE_PARM_DESC(force, "Forcibly enable the SIS630. DANGEROUS!");
 112
 113 /* SMBus base adress */
 114 static unsigned short smbus_base;
 115
 116 /* supported chips */
 117 static int supported[] = {
 118         PCI_DEVICE_ID_SI_630,
 119         PCI_DEVICE_ID_SI_730,
 120         PCI_DEVICE_ID_SI_760,
 121         0 /* terminates the list */
 122 };
 123
 124 static inline u8 sis630_read(u8 reg)
 125 {
 126         return inb(smbus_base + reg);
 127 }
 128
 129 static inline void sis630_write(u8 reg, u8 data)
 130 {
 131         outb(data, smbus_base + reg);
 132 }
 133
 134 static int sis630_transaction_start(struct i2c_adapter *adap, int size,
 135                                     u8 *oldclock)
 136 {
 137         int temp;
 138
 139         /* Make sure the SMBus host is ready to start transmitting. */
 140         temp = sis630_read(SMB_CNT);
 141         if ((temp & (SMB_PROBE | SMB_HOSTBUSY)) != 0x00) {
 142                 dev_dbg(&adap->dev, "SMBus busy (%02x). Resetting...\n", temp);
 143                 /* kill smbus transaction */
 144                 sis630_write(SMBHOST_CNT, SMB_KILL);
 145
 146                 temp = sis630_read(SMB_CNT);
 147                 if (temp & (SMB_PROBE | SMB_HOSTBUSY)) {
 148                         dev_dbg(&adap->dev, "Failed! (%02x)\n", temp);
 149                         return -EBUSY;
 150                 } else {
 151                         dev_dbg(&adap->dev, "Successful!\n");
 152                 }
 153         }
 154
 155         /* save old clock, so we can prevent machine for hung */
 156         *oldclock = sis630_read(SMB_CNT);
 157
 158         dev_dbg(&adap->dev, "saved clock 0x%02x\n", *oldclock);
 159
 160         /* disable timeout interrupt,
 161          * set Host Master Clock to 56KHz if requested */
 162         if (high_clock)
 163                 sis630_write(SMB_CNT, SMBCLK_SEL);
 164         else
 165                 sis630_write(SMB_CNT, (*oldclock & ~MSTO_EN));
 166
 167         /* clear all sticky bits */
 168         temp = sis630_read(SMB_STS);
 169         sis630_write(SMB_STS, temp & 0x1e);
 170
 171         /* start the transaction by setting bit 4 and size */
 172         sis630_write(SMBHOST_CNT, SMB_START | (size & 0x07));
 173
 174         return 0;
 175 }
 176
 177 static int sis630_transaction_wait(struct i2c_adapter *adap, int size)
 178 {
 179         int temp, result = 0, timeout = 0;
 180
 181         /* We will always wait for a fraction of a second! */
 182         do {
 183                 msleep(1);
 184                 temp = sis630_read(SMB_STS);
 185                 /* check if block transmitted */
 186                 if (size == SIS630_BLOCK_DATA && (temp & BYTE_DONE_STS))
 187                         break;
 188         } while (!(temp & 0x0e) && (timeout++ < MAX_TIMEOUT));
 189
 190         /* If the SMBus is still busy, we give up */
 191         if (timeout > MAX_TIMEOUT) {
 192                 dev_dbg(&adap->dev, "SMBus Timeout!\n");
 193                 result = -ETIMEDOUT;
 194         }
 195
 196         if (temp & SMBERR_STS) {
 197                 dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
 198                 result = -ENXIO;
 199         }
 200
 201         if (temp & SMBCOL_STS) {
 202                 dev_err(&adap->dev, "Bus collision!\n");
 203                 result = -EAGAIN;
 204         }
 205
 206         return result;
 207 }
 208
 209 static void sis630_transaction_end(struct i2c_adapter *adap, u8 oldclock)
 210 {
 211         /* clear all status "sticky" bits */
 212         sis630_write(SMB_STS, 0xFF);
 213
 214         dev_dbg(&adap->dev,
 215                 "SMB_CNT before clock restore 0x%02x\n", sis630_read(SMB_CNT));
 216
 217         /*
 218          * restore old Host Master Clock if high_clock is set
 219          * and oldclock was not 56KHz
 220          */
 221         if (high_clock && !(oldclock & SMBCLK_SEL))
 222                 sis630_write(SMB_CNT, sis630_read(SMB_CNT) & ~SMBCLK_SEL);
 223
 224         dev_dbg(&adap->dev,
 225                 "SMB_CNT after clock restore 0x%02x\n", sis630_read(SMB_CNT));
 226 }
 227
 228 static int sis630_transaction(struct i2c_adapter *adap, int size)
 229 {
 230         int result = 0;
 231         u8 oldclock = 0;
 232
 233         result = sis630_transaction_start(adap, size, &oldclock);
 234         if (!result) {
 235                 result = sis630_transaction_wait(adap, size);
 236                 sis630_transaction_end(adap, oldclock);
 237         }
 238
 239         return result;
 240 }
 241
 242 static int sis630_block_data(struct i2c_adapter *adap,
 243                              union i2c_smbus_data *data, int read_write)
 244 {
 245         int i, len = 0, rc = 0;
 246         u8 oldclock = 0;
 247
 248         if (read_write == I2C_SMBUS_WRITE) {
 249                 len = data->block[0];
 250                 if (len < 0)
 251                         len = 0;
 252                 else if (len > 32)
 253                         len = 32;
 254                 sis630_write(SMB_COUNT, len);
 255                 for (i = 1; i <= len; i++) {
 256                         dev_dbg(&adap->dev,
 257                                 "set data 0x%02x\n", data->block[i]);
 258                         /* set data */
 259                         sis630_write(SMB_BYTE + (i - 1) % 8, data->block[i]);
 260                         if (i == 8 || (len < 8 && i == len)) {
 261                                 dev_dbg(&adap->dev,
 262                                         "start trans len=%d i=%d\n", len, i);
 263                                 /* first transaction */
 264                                 rc = sis630_transaction_start(adap,
 265                                                 SIS630_BLOCK_DATA, &oldclock);
 266                                 if (rc)
 267                                         return rc;
 268                         } else if ((i - 1) % 8 == 7 || i == len) {
 269                                 dev_dbg(&adap->dev,
 270                                         "trans_wait len=%d i=%d\n", len, i);
 271                                 if (i > 8) {
 272                                         dev_dbg(&adap->dev,
 273                                                 "clear smbary_sts"
 274                                                 " len=%d i=%d\n", len, i);
 275                                         /*
 276                                            If this is not first transaction,
 277                                            we must clear sticky bit.
 278                                            clear SMBARY_STS
 279                                         */
 280                                         sis630_write(SMB_STS, BYTE_DONE_STS);
 281                                 }
 282                                 rc = sis630_transaction_wait(adap,
 283                                                 SIS630_BLOCK_DATA);
 284                                 if (rc) {
 285                                         dev_dbg(&adap->dev,
 286                                                 "trans_wait failed\n");
 287                                         break;
 288                                 }
 289                         }
 290                 }
 291         } else {
 292                 /* read request */
 293                 data->block[0] = len = 0;
 294                 rc = sis630_transaction_start(adap,
 295                                 SIS630_BLOCK_DATA, &oldclock);
 296                 if (rc)
 297                         return rc;
 298                 do {
 299                         rc = sis630_transaction_wait(adap, SIS630_BLOCK_DATA);
 300                         if (rc) {
 301                                 dev_dbg(&adap->dev, "trans_wait failed\n");
 302                                 break;
 303                         }
 304                         /* if this first transaction then read byte count */
 305                         if (len == 0)
 306                                 data->block[0] = sis630_read(SMB_COUNT);
 307
 308                         /* just to be sure */
 309                         if (data->block[0] > 32)
 310                                 data->block[0] = 32;
 311
 312                         dev_dbg(&adap->dev,
 313                                 "block data read len=0x%x\n", data->block[0]);
 314
 315                         for (i = 0; i < 8 && len < data->block[0]; i++, len++) {
 316                                 dev_dbg(&adap->dev,
 317                                         "read i=%d len=%d\n", i, len);
 318                                 data->block[len + 1] = sis630_read(SMB_BYTE +
 319                                                                    i);
 320                         }
 321
 322                         dev_dbg(&adap->dev,
 323                                 "clear smbary_sts len=%d i=%d\n", len, i);
 324
 325                         /* clear SMBARY_STS */
 326                         sis630_write(SMB_STS, BYTE_DONE_STS);
 327                 } while (len < data->block[0]);
 328         }
 329
 330         sis630_transaction_end(adap, oldclock);
 331
 332         return rc;
 333 }
 334
 335 /* Return negative errno on error. */
 336 static s32 sis630_access(struct i2c_adapter *adap, u16 addr,
 337                          unsigned short flags, char read_write,
 338                          u8 command, int size, union i2c_smbus_data *data)
 339 {
 340         int status;
 341
 342         switch (size) {
 343         case I2C_SMBUS_QUICK:
 344                 sis630_write(SMB_ADDR,
 345                              ((addr & 0x7f) << 1) | (read_write & 0x01));
 346                 size = SIS630_QUICK;
 347                 break;
 348         case I2C_SMBUS_BYTE:
 349                 sis630_write(SMB_ADDR,
 350                              ((addr & 0x7f) << 1) | (read_write & 0x01));
 351                 if (read_write == I2C_SMBUS_WRITE)
 352                         sis630_write(SMB_CMD, command);
 353                 size = SIS630_BYTE;
 354                 break;
 355         case I2C_SMBUS_BYTE_DATA:
 356                 sis630_write(SMB_ADDR,
 357                              ((addr & 0x7f) << 1) | (read_write & 0x01));
 358                 sis630_write(SMB_CMD, command);
 359                 if (read_write == I2C_SMBUS_WRITE)
 360                         sis630_write(SMB_BYTE, data->byte);
 361                 size = SIS630_BYTE_DATA;
 362                 break;
 363         case I2C_SMBUS_PROC_CALL:
 364         case I2C_SMBUS_WORD_DATA:
 365                 sis630_write(SMB_ADDR,
 366                              ((addr & 0x7f) << 1) | (read_write & 0x01));
 367                 sis630_write(SMB_CMD, command);
 368                 if (read_write == I2C_SMBUS_WRITE) {
 369                         sis630_write(SMB_BYTE, data->word & 0xff);
 370                         sis630_write(SMB_BYTE + 1, (data->word & 0xff00) >> 8);
 371                 }
 372                 size = (size == I2C_SMBUS_PROC_CALL ?
 373                         SIS630_PCALL : SIS630_WORD_DATA);
 374                 break;
 375         case I2C_SMBUS_BLOCK_DATA:
 376                 sis630_write(SMB_ADDR,
 377                              ((addr & 0x7f) << 1) | (read_write & 0x01));
 378                 sis630_write(SMB_CMD, command);
 379                 size = SIS630_BLOCK_DATA;
 380                 return sis630_block_data(adap, data, read_write);
 381         default:
 382                 dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
 383                 return -EOPNOTSUPP;
 384         }
 385
 386         status = sis630_transaction(adap, size);
 387         if (status)
 388                 return status;
 389
 390         if ((size != SIS630_PCALL) &&
 391                 ((read_write == I2C_SMBUS_WRITE) || (size == SIS630_QUICK))) {
 392                 return 0;
 393         }
 394
 395         switch (size) {
 396         case SIS630_BYTE:
 397         case SIS630_BYTE_DATA:
 398                 data->byte = sis630_read(SMB_BYTE);
 399                 break;
 400         case SIS630_PCALL:
 401         case SIS630_WORD_DATA:
 402                 data->word = sis630_read(SMB_BYTE) +
 403                              (sis630_read(SMB_BYTE + 1) << 8);
 404                 break;
 405         }
 406
 407         return 0;
 408 }
 409
 410 static u32 sis630_func(struct i2c_adapter *adapter)
 411 {
 412         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 413                 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 414                 I2C_FUNC_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_BLOCK_DATA;
 415 }
 416
 417 static int sis630_setup(struct pci_dev *sis630_dev)
 418 {
 419         unsigned char b;
 420         struct pci_dev *dummy = NULL;
 421         int retval, i;
 422         /* acpi base address */
 423         unsigned short acpi_base;
 424
 425         /* check for supported SiS devices */
 426         for (i = 0; supported[i] > 0; i++) {
 427                 dummy = pci_get_device(PCI_VENDOR_ID_SI, supported[i], dummy);
 428                 if (dummy)
 429                         break; /* found */
 430         }
 431
 432         if (dummy) {
 433                 pci_dev_put(dummy);
 434         } else if (force) {
 435                 dev_err(&sis630_dev->dev,
 436                         "WARNING: Can't detect SIS630 compatible device, but "
 437                         "loading because of force option enabled\n");
 438         } else {
 439                 return -ENODEV;
 440         }
 441
 442         /*
 443            Enable ACPI first , so we can accsess reg 74-75
 444            in acpi io space and read acpi base addr
 445         */
 446         if (pci_read_config_byte(sis630_dev, SIS630_BIOS_CTL_REG, &b)) {
 447                 dev_err(&sis630_dev->dev, "Error: Can't read bios ctl reg\n");
 448                 retval = -ENODEV;
 449                 goto exit;
 450         }
 451         /* if ACPI already enabled , do nothing */
 452         if (!(b & 0x80) &&
 453             pci_write_config_byte(sis630_dev, SIS630_BIOS_CTL_REG, b | 0x80)) {
 454                 dev_err(&sis630_dev->dev, "Error: Can't enable ACPI\n");
 455                 retval = -ENODEV;
 456                 goto exit;
 457         }
 458
 459         /* Determine the ACPI base address */
 460         if (pci_read_config_word(sis630_dev,
 461                                  SIS630_ACPI_BASE_REG, &acpi_base)) {
 462                 dev_err(&sis630_dev->dev,
 463                         "Error: Can't determine ACPI base address\n");
 464                 retval = -ENODEV;
 465                 goto exit;
 466         }
 467
 468         dev_dbg(&sis630_dev->dev, "ACPI base at 0x%04hx\n", acpi_base);
 469
 470         if (supported[i] == PCI_DEVICE_ID_SI_760)
 471                 smbus_base = acpi_base + 0xE0;
 472         else
 473                 smbus_base = acpi_base + 0x80;
 474
 475         dev_dbg(&sis630_dev->dev, "SMBus base at 0x%04hx\n", smbus_base);
 476
 477         retval = acpi_check_region(smbus_base + SMB_STS, SIS630_SMB_IOREGION,
 478                                    sis630_driver.name);
 479         if (retval)
 480                 goto exit;
 481
 482         /* Everything is happy, let's grab the memory and set things up. */
 483         if (!request_region(smbus_base + SMB_STS, SIS630_SMB_IOREGION,
 484                             sis630_driver.name)) {
 485                 dev_err(&sis630_dev->dev,
 486                         "I/O Region 0x%04hx-0x%04hx for SMBus already in use.\n",
 487                         smbus_base + SMB_STS,
 488                         smbus_base + SMB_STS + SIS630_SMB_IOREGION - 1);
 489                 retval = -EBUSY;
 490                 goto exit;
 491         }
 492
 493         retval = 0;
 494
 495 exit:
 496         if (retval)
 497                 smbus_base = 0;
 498         return retval;
 499 }
 500
 501
 502 static const struct i2c_algorithm smbus_algorithm = {
 503         .smbus_xfer     = sis630_access,
 504         .functionality  = sis630_func,
 505 };
 506
 507 static struct i2c_adapter sis630_adapter = {
 508         .owner          = THIS_MODULE,
 509         .class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
 510         .algo           = &smbus_algorithm,
 511         .retries        = 3
 512 };
 513
 514 static DEFINE_PCI_DEVICE_TABLE(sis630_ids) = {
 515         { PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_503) },
 516         { PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_LPC) },
 517         { PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_964) },
 518         { 0, }
 519 };
 520
 521 MODULE_DEVICE_TABLE(pci, sis630_ids);
 522
 523 static int sis630_probe(struct pci_dev *dev, const struct pci_device_id *id)
 524 {
 525         if (sis630_setup(dev)) {
 526                 dev_err(&dev->dev,
 527                         "SIS630 compatible bus not detected, "
 528                         "module not inserted.\n");
 529                 return -ENODEV;
 530         }
 531
 532         /* set up the sysfs linkage to our parent device */
 533         sis630_adapter.dev.parent = &dev->dev;
 534
 535         snprintf(sis630_adapter.name, sizeof(sis630_adapter.name),
 536                  "SMBus SIS630 adapter at %04hx", smbus_base + SMB_STS);
 537
 538         return i2c_add_adapter(&sis630_adapter);
 539 }
 540
 541 static void sis630_remove(struct pci_dev *dev)
 542 {
 543         if (smbus_base) {
 544                 i2c_del_adapter(&sis630_adapter);
 545                 release_region(smbus_base + SMB_STS, SIS630_SMB_IOREGION);
 546                 smbus_base = 0;
 547         }
 548 }
 549
 550
 551 static struct pci_driver sis630_driver = {
 552         .name           = "sis630_smbus",
 553         .id_table       = sis630_ids,
 554         .probe          = sis630_probe,
 555         .remove         = sis630_remove,
 556 };
 557
 558 module_pci_driver(sis630_driver);
 559
 560 MODULE_LICENSE("GPL");
 561 MODULE_AUTHOR("Alexander Malysh <amalysh@web.de>");
 562 MODULE_DESCRIPTION("SIS630 SMBus driver");