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