LXR linux/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
 102static struct pci_driver sis630_driver;
 103
 104/* insmod parameters */
 105static bool high_clock;
 106static bool force;
 107module_param(high_clock, bool, 0);
 108MODULE_PARM_DESC(high_clock,
 109        "Set Host Master Clock to 56KHz (default 14KHz) (SIS630/730 only).");
 110module_param(force, bool, 0);
 111MODULE_PARM_DESC(force, "Forcibly enable the SIS630. DANGEROUS!");
 112
 113/* SMBus base adress */
 114static unsigned short smbus_base;
 115
 116/* supported chips */
 117static 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
 124static inline u8 sis630_read(u8 reg)
 125{
 126        return inb(smbus_base + reg);
 127}
 128
 129static inline void sis630_write(u8 reg, u8 data)
 130{
 131        outb(data, smbus_base + reg);
 132}
 133
 134static 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
 177static 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
 209static 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
 228static 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
 242static 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. */
 336static 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
 410static 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
 417static 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
 495exit:
 496        if (retval)
 497                smbus_base = 0;
 498        return retval;
 499}
 500
 501
 502static const struct i2c_algorithm smbus_algorithm = {
 503        .smbus_xfer     = sis630_access,
 504        .functionality  = sis630_func,
 505};
 506
 507static 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
 514static 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
 521MODULE_DEVICE_TABLE(pci, sis630_ids);
 522
 523static 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
 541static 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
 551static struct pci_driver sis630_driver = {
 552        .name           = "sis630_smbus",
 553        .id_table       = sis630_ids,
 554        .probe          = sis630_probe,
 555        .remove         = sis630_remove,
 556};
 557
 558module_pci_driver(sis630_driver);
 559
 560MODULE_LICENSE("GPL");
 561MODULE_AUTHOR("Alexander Malysh <amalysh@web.de>");
 562MODULE_DESCRIPTION("SIS630 SMBus driver");
 563