LXR linux/drivers/i2c/busses/i2c-ali1535.c

   1/*
   2 * Copyright (c) 2000  Frodo Looijaard <frodol@dds.nl>,
   3 *                      Philip Edelbrock <phil@netroedge.com>,
   4 *                      Mark D. Studebaker <mdsxyz123@yahoo.com>,
   5 *                      Dan Eaton <dan.eaton@rocketlogix.com> and
   6 *                      Stephen Rousset <stephen.rousset@rocketlogix.com>
   7 *
   8 *  This program is free software; you can redistribute it and/or modify
   9 *  it under the terms of the GNU General Public License as published by
  10 *  the Free Software Foundation; either version 2 of the License, or
  11 *  (at your option) any later version.
  12 *
  13 *  This program is distributed in the hope that it will be useful,
  14 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 *  GNU General Public License for more details.
  17*/
  18
  19/*
  20    This is the driver for the SMB Host controller on
  21    Acer Labs Inc. (ALI) M1535 South Bridge.
  22
  23    The M1535 is a South bridge for portable systems.
  24    It is very similar to the M15x3 South bridges also produced
  25    by Acer Labs Inc.  Some of the registers within the part
  26    have moved and some have been redefined slightly. Additionally,
  27    the sequencing of the SMBus transactions has been modified
  28    to be more consistent with the sequencing recommended by
  29    the manufacturer and observed through testing.  These
  30    changes are reflected in this driver and can be identified
  31    by comparing this driver to the i2c-ali15x3 driver.
  32    For an overview of these chips see http://www.acerlabs.com
  33
  34    The SMB controller is part of the 7101 device, which is an
  35    ACPI-compliant Power Management Unit (PMU).
  36
  37    The whole 7101 device has to be enabled for the SMB to work.
  38    You can't just enable the SMB alone.
  39    The SMB and the ACPI have separate I/O spaces.
  40    We make sure that the SMB is enabled. We leave the ACPI alone.
  41
  42    This driver controls the SMB Host only.
  43
  44    This driver does not use interrupts.
  45*/
  46
  47
  48/* Note: we assume there can only be one ALI1535, with one SMBus interface */
  49
  50#include <linux/module.h>
  51#include <linux/pci.h>
  52#include <linux/kernel.h>
  53#include <linux/stddef.h>
  54#include <linux/delay.h>
  55#include <linux/ioport.h>
  56#include <linux/i2c.h>
  57#include <linux/acpi.h>
  58#include <linux/io.h>
  59
  60
  61/* ALI1535 SMBus address offsets */
  62#define SMBHSTSTS       (0 + ali1535_smba)
  63#define SMBHSTTYP       (1 + ali1535_smba)
  64#define SMBHSTPORT      (2 + ali1535_smba)
  65#define SMBHSTCMD       (7 + ali1535_smba)
  66#define SMBHSTADD       (3 + ali1535_smba)
  67#define SMBHSTDAT0      (4 + ali1535_smba)
  68#define SMBHSTDAT1      (5 + ali1535_smba)
  69#define SMBBLKDAT       (6 + ali1535_smba)
  70
  71/* PCI Address Constants */
  72#define SMBCOM          0x004
  73#define SMBREV          0x008
  74#define SMBCFG          0x0D1
  75#define SMBBA           0x0E2
  76#define SMBHSTCFG       0x0F0
  77#define SMBCLK          0x0F2
  78
  79/* Other settings */
  80#define MAX_TIMEOUT             500     /* times 1/100 sec */
  81#define ALI1535_SMB_IOSIZE      32
  82
  83#define ALI1535_SMB_DEFAULTBASE 0x8040
  84
  85/* ALI1535 address lock bits */
  86#define ALI1535_LOCK            0x06    /* dwe */
  87
  88/* ALI1535 command constants */
  89#define ALI1535_QUICK           0x00
  90#define ALI1535_BYTE            0x10
  91#define ALI1535_BYTE_DATA       0x20
  92#define ALI1535_WORD_DATA       0x30
  93#define ALI1535_BLOCK_DATA      0x40
  94#define ALI1535_I2C_READ        0x60
  95
  96#define ALI1535_DEV10B_EN       0x80    /* Enable 10-bit addressing in  */
  97                                        /*  I2C read                    */
  98#define ALI1535_T_OUT           0x08    /* Time-out Command (write)     */
  99#define ALI1535_A_HIGH_BIT9     0x08    /* Bit 9 of 10-bit address in   */
 100                                        /* Alert-Response-Address       */
 101                                        /* (read)                       */
 102#define ALI1535_KILL            0x04    /* Kill Command (write)         */
 103#define ALI1535_A_HIGH_BIT8     0x04    /* Bit 8 of 10-bit address in   */
 104                                        /*  Alert-Response-Address      */
 105                                        /*  (read)                      */
 106
 107#define ALI1535_D_HI_MASK       0x03    /* Mask for isolating bits 9-8  */
 108                                        /*  of 10-bit address in I2C    */
 109                                        /*  Read Command                */
 110
 111/* ALI1535 status register bits */
 112#define ALI1535_STS_IDLE        0x04
 113#define ALI1535_STS_BUSY        0x08    /* host busy */
 114#define ALI1535_STS_DONE        0x10    /* transaction complete */
 115#define ALI1535_STS_DEV         0x20    /* device error */
 116#define ALI1535_STS_BUSERR      0x40    /* bus error    */
 117#define ALI1535_STS_FAIL        0x80    /* failed bus transaction */
 118#define ALI1535_STS_ERR         0xE0    /* all the bad error bits */
 119
 120#define ALI1535_BLOCK_CLR       0x04    /* reset block data index */
 121
 122/* ALI1535 device address register bits */
 123#define ALI1535_RD_ADDR         0x01    /* Read/Write Bit in Device     */
 124                                        /*  Address field               */
 125                                        /*  -> Write = 0                */
 126                                        /*  -> Read  = 1                */
 127#define ALI1535_SMBIO_EN        0x04    /* SMB I/O Space enable         */
 128
 129static struct pci_driver ali1535_driver;
 130static unsigned long ali1535_smba;
 131static unsigned short ali1535_offset;
 132
 133/* Detect whether a ALI1535 can be found, and initialize it, where necessary.
 134   Note the differences between kernels with the old PCI BIOS interface and
 135   newer kernels with the real PCI interface. In compat.h some things are
 136   defined to make the transition easier. */
 137static int ali1535_setup(struct pci_dev *dev)
 138{
 139        int retval;
 140        unsigned char temp;
 141
 142        /* Check the following things:
 143                - SMB I/O address is initialized
 144                - Device is enabled
 145                - We can use the addresses
 146        */
 147
 148        retval = pci_enable_device(dev);
 149        if (retval) {
 150                dev_err(&dev->dev, "ALI1535_smb can't enable device\n");
 151                goto exit;
 152        }
 153
 154        /* Determine the address of the SMBus area */
 155        pci_read_config_word(dev, SMBBA, &ali1535_offset);
 156        dev_dbg(&dev->dev, "ALI1535_smb is at offset 0x%04x\n", ali1535_offset);
 157        ali1535_offset &= (0xffff & ~(ALI1535_SMB_IOSIZE - 1));
 158        if (ali1535_offset == 0) {
 159                dev_warn(&dev->dev,
 160                        "ALI1535_smb region uninitialized - upgrade BIOS?\n");
 161                retval = -ENODEV;
 162                goto exit;
 163        }
 164
 165        if (pci_resource_flags(dev, 0) & IORESOURCE_IO)
 166                ali1535_smba = pci_resource_start(dev, 0) + ali1535_offset;
 167        else
 168                ali1535_smba = ali1535_offset;
 169
 170        retval = acpi_check_region(ali1535_smba, ALI1535_SMB_IOSIZE,
 171                                   ali1535_driver.name);
 172        if (retval)
 173                goto exit;
 174
 175        if (!request_region(ali1535_smba, ALI1535_SMB_IOSIZE,
 176                            ali1535_driver.name)) {
 177                dev_err(&dev->dev, "ALI1535_smb region 0x%lx already in use!\n",
 178                        ali1535_smba);
 179                retval = -EBUSY;
 180                goto exit;
 181        }
 182
 183        /* check if whole device is enabled */
 184        pci_read_config_byte(dev, SMBCFG, &temp);
 185        if ((temp & ALI1535_SMBIO_EN) == 0) {
 186                dev_err(&dev->dev, "SMB device not enabled - upgrade BIOS?\n");
 187                retval = -ENODEV;
 188                goto exit_free;
 189        }
 190
 191        /* Is SMB Host controller enabled? */
 192        pci_read_config_byte(dev, SMBHSTCFG, &temp);
 193        if ((temp & 1) == 0) {
 194                dev_err(&dev->dev, "SMBus controller not enabled - upgrade BIOS?\n");
 195                retval = -ENODEV;
 196                goto exit_free;
 197        }
 198
 199        /* set SMB clock to 74KHz as recommended in data sheet */
 200        pci_write_config_byte(dev, SMBCLK, 0x20);
 201
 202        /*
 203          The interrupt routing for SMB is set up in register 0x77 in the
 204          1533 ISA Bridge device, NOT in the 7101 device.
 205          Don't bother with finding the 1533 device and reading the register.
 206        if ((....... & 0x0F) == 1)
 207                dev_dbg(&dev->dev, "ALI1535 using Interrupt 9 for SMBus.\n");
 208        */
 209        pci_read_config_byte(dev, SMBREV, &temp);
 210        dev_dbg(&dev->dev, "SMBREV = 0x%X\n", temp);
 211        dev_dbg(&dev->dev, "ALI1535_smba = 0x%lx\n", ali1535_smba);
 212
 213        return 0;
 214
 215exit_free:
 216        release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
 217exit:
 218        return retval;
 219}
 220
 221static int ali1535_transaction(struct i2c_adapter *adap)
 222{
 223        int temp;
 224        int result = 0;
 225        int timeout = 0;
 226
 227        dev_dbg(&adap->dev, "Transaction (pre): STS=%02x, TYP=%02x, "
 228                "CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
 229                inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
 230                inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
 231
 232        /* get status */
 233        temp = inb_p(SMBHSTSTS);
 234
 235        /* Make sure the SMBus host is ready to start transmitting */
 236        /* Check the busy bit first */
 237        if (temp & ALI1535_STS_BUSY) {
 238                /* If the host controller is still busy, it may have timed out
 239                 * in the previous transaction, resulting in a "SMBus Timeout"
 240                 * printk.  I've tried the following to reset a stuck busy bit.
 241                 *   1. Reset the controller with an KILL command. (this
 242                 *      doesn't seem to clear the controller if an external
 243                 *      device is hung)
 244                 *   2. Reset the controller and the other SMBus devices with a
 245                 *      T_OUT command. (this clears the host busy bit if an
 246                 *      external device is hung, but it comes back upon a new
 247                 *      access to a device)
 248                 *   3. Disable and reenable the controller in SMBHSTCFG. Worst
 249                 *      case, nothing seems to work except power reset.
 250                 */
 251
 252                /* Try resetting entire SMB bus, including other devices - This
 253                 * may not work either - it clears the BUSY bit but then the
 254                 * BUSY bit may come back on when you try and use the chip
 255                 * again.  If that's the case you are stuck.
 256                 */
 257                dev_info(&adap->dev,
 258                        "Resetting entire SMB Bus to clear busy condition (%02x)\n",
 259                        temp);
 260                outb_p(ALI1535_T_OUT, SMBHSTTYP);
 261                temp = inb_p(SMBHSTSTS);
 262        }
 263
 264        /* now check the error bits and the busy bit */
 265        if (temp & (ALI1535_STS_ERR | ALI1535_STS_BUSY)) {
 266                /* do a clear-on-write */
 267                outb_p(0xFF, SMBHSTSTS);
 268                temp = inb_p(SMBHSTSTS);
 269                if (temp & (ALI1535_STS_ERR | ALI1535_STS_BUSY)) {
 270                        /* This is probably going to be correctable only by a
 271                         * power reset as one of the bits now appears to be
 272                         * stuck */
 273                        /* This may be a bus or device with electrical problems. */
 274                        dev_err(&adap->dev,
 275                                "SMBus reset failed! (0x%02x) - controller or "
 276                                "device on bus is probably hung\n", temp);
 277                        return -EBUSY;
 278                }
 279        } else {
 280                /* check and clear done bit */
 281                if (temp & ALI1535_STS_DONE)
 282                        outb_p(temp, SMBHSTSTS);
 283        }
 284
 285        /* start the transaction by writing anything to the start register */
 286        outb_p(0xFF, SMBHSTPORT);
 287
 288        /* We will always wait for a fraction of a second! */
 289        timeout = 0;
 290        do {
 291                usleep_range(1000, 2000);
 292                temp = inb_p(SMBHSTSTS);
 293        } while (((temp & ALI1535_STS_BUSY) && !(temp & ALI1535_STS_IDLE))
 294                 && (timeout++ < MAX_TIMEOUT));
 295
 296        /* If the SMBus is still busy, we give up */
 297        if (timeout > MAX_TIMEOUT) {
 298                result = -ETIMEDOUT;
 299                dev_err(&adap->dev, "SMBus Timeout!\n");
 300        }
 301
 302        if (temp & ALI1535_STS_FAIL) {
 303                result = -EIO;
 304                dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
 305        }
 306
 307        /* Unfortunately the ALI SMB controller maps "no response" and "bus
 308         * collision" into a single bit. No response is the usual case so don't
 309         * do a printk.  This means that bus collisions go unreported.
 310         */
 311        if (temp & ALI1535_STS_BUSERR) {
 312                result = -ENXIO;
 313                dev_dbg(&adap->dev,
 314                        "Error: no response or bus collision ADD=%02x\n",
 315                        inb_p(SMBHSTADD));
 316        }
 317
 318        /* haven't ever seen this */
 319        if (temp & ALI1535_STS_DEV) {
 320                result = -EIO;
 321                dev_err(&adap->dev, "Error: device error\n");
 322        }
 323
 324        /* check to see if the "command complete" indication is set */
 325        if (!(temp & ALI1535_STS_DONE)) {
 326                result = -ETIMEDOUT;
 327                dev_err(&adap->dev, "Error: command never completed\n");
 328        }
 329
 330        dev_dbg(&adap->dev, "Transaction (post): STS=%02x, TYP=%02x, "
 331                "CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
 332                inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
 333                inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
 334
 335        /* take consequent actions for error conditions */
 336        if (!(temp & ALI1535_STS_DONE)) {
 337                /* issue "kill" to reset host controller */
 338                outb_p(ALI1535_KILL, SMBHSTTYP);
 339                outb_p(0xFF, SMBHSTSTS);
 340        } else if (temp & ALI1535_STS_ERR) {
 341                /* issue "timeout" to reset all devices on bus */
 342                outb_p(ALI1535_T_OUT, SMBHSTTYP);
 343                outb_p(0xFF, SMBHSTSTS);
 344        }
 345
 346        return result;
 347}
 348
 349/* Return negative errno on error. */
 350static s32 ali1535_access(struct i2c_adapter *adap, u16 addr,
 351                          unsigned short flags, char read_write, u8 command,
 352                          int size, union i2c_smbus_data *data)
 353{
 354        int i, len;
 355        int temp;
 356        int timeout;
 357        s32 result = 0;
 358
 359        /* make sure SMBus is idle */
 360        temp = inb_p(SMBHSTSTS);
 361        for (timeout = 0;
 362             (timeout < MAX_TIMEOUT) && !(temp & ALI1535_STS_IDLE);
 363             timeout++) {
 364                usleep_range(1000, 2000);
 365                temp = inb_p(SMBHSTSTS);
 366        }
 367        if (timeout >= MAX_TIMEOUT)
 368                dev_warn(&adap->dev, "Idle wait Timeout! STS=0x%02x\n", temp);
 369
 370        /* clear status register (clear-on-write) */
 371        outb_p(0xFF, SMBHSTSTS);
 372
 373        switch (size) {
 374        case I2C_SMBUS_QUICK:
 375                outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 376                       SMBHSTADD);
 377                size = ALI1535_QUICK;
 378                outb_p(size, SMBHSTTYP);        /* output command */
 379                break;
 380        case I2C_SMBUS_BYTE:
 381                outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 382                       SMBHSTADD);
 383                size = ALI1535_BYTE;
 384                outb_p(size, SMBHSTTYP);        /* output command */
 385                if (read_write == I2C_SMBUS_WRITE)
 386                        outb_p(command, SMBHSTCMD);
 387                break;
 388        case I2C_SMBUS_BYTE_DATA:
 389                outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 390                       SMBHSTADD);
 391                size = ALI1535_BYTE_DATA;
 392                outb_p(size, SMBHSTTYP);        /* output command */
 393                outb_p(command, SMBHSTCMD);
 394                if (read_write == I2C_SMBUS_WRITE)
 395                        outb_p(data->byte, SMBHSTDAT0);
 396                break;
 397        case I2C_SMBUS_WORD_DATA:
 398                outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 399                       SMBHSTADD);
 400                size = ALI1535_WORD_DATA;
 401                outb_p(size, SMBHSTTYP);        /* output command */
 402                outb_p(command, SMBHSTCMD);
 403                if (read_write == I2C_SMBUS_WRITE) {
 404                        outb_p(data->word & 0xff, SMBHSTDAT0);
 405                        outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
 406                }
 407                break;
 408        case I2C_SMBUS_BLOCK_DATA:
 409                outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 410                       SMBHSTADD);
 411                size = ALI1535_BLOCK_DATA;
 412                outb_p(size, SMBHSTTYP);        /* output command */
 413                outb_p(command, SMBHSTCMD);
 414                if (read_write == I2C_SMBUS_WRITE) {
 415                        len = data->block[0];
 416                        if (len < 0) {
 417                                len = 0;
 418                                data->block[0] = len;
 419                        }
 420                        if (len > 32) {
 421                                len = 32;
 422                                data->block[0] = len;
 423                        }
 424                        outb_p(len, SMBHSTDAT0);
 425                        /* Reset SMBBLKDAT */
 426                        outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
 427                        for (i = 1; i <= len; i++)
 428                                outb_p(data->block[i], SMBBLKDAT);
 429                }
 430                break;
 431        default:
 432                dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
 433                result = -EOPNOTSUPP;
 434                goto EXIT;
 435        }
 436
 437        result = ali1535_transaction(adap);
 438        if (result)
 439                goto EXIT;
 440
 441        if ((read_write == I2C_SMBUS_WRITE) || (size == ALI1535_QUICK)) {
 442                result = 0;
 443                goto EXIT;
 444        }
 445
 446        switch (size) {
 447        case ALI1535_BYTE:      /* Result put in SMBHSTDAT0 */
 448                data->byte = inb_p(SMBHSTDAT0);
 449                break;
 450        case ALI1535_BYTE_DATA:
 451                data->byte = inb_p(SMBHSTDAT0);
 452                break;
 453        case ALI1535_WORD_DATA:
 454                data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
 455                break;
 456        case ALI1535_BLOCK_DATA:
 457                len = inb_p(SMBHSTDAT0);
 458                if (len > 32)
 459                        len = 32;
 460                data->block[0] = len;
 461                /* Reset SMBBLKDAT */
 462                outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
 463                for (i = 1; i <= data->block[0]; i++) {
 464                        data->block[i] = inb_p(SMBBLKDAT);
 465                        dev_dbg(&adap->dev, "Blk: len=%d, i=%d, data=%02x\n",
 466                                len, i, data->block[i]);
 467                }
 468                break;
 469        }
 470EXIT:
 471        return result;
 472}
 473
 474
 475static u32 ali1535_func(struct i2c_adapter *adapter)
 476{
 477        return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 478            I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 479            I2C_FUNC_SMBUS_BLOCK_DATA;
 480}
 481
 482static const struct i2c_algorithm smbus_algorithm = {
 483        .smbus_xfer     = ali1535_access,
 484        .functionality  = ali1535_func,
 485};
 486
 487static struct i2c_adapter ali1535_adapter = {
 488        .owner          = THIS_MODULE,
 489        .class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
 490        .algo           = &smbus_algorithm,
 491};
 492
 493static const struct pci_device_id ali1535_ids[] = {
 494        { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
 495        { },
 496};
 497
 498MODULE_DEVICE_TABLE(pci, ali1535_ids);
 499
 500static int ali1535_probe(struct pci_dev *dev, const struct pci_device_id *id)
 501{
 502        if (ali1535_setup(dev)) {
 503                dev_warn(&dev->dev,
 504                        "ALI1535 not detected, module not inserted.\n");
 505                return -ENODEV;
 506        }
 507
 508        /* set up the sysfs linkage to our parent device */
 509        ali1535_adapter.dev.parent = &dev->dev;
 510
 511        snprintf(ali1535_adapter.name, sizeof(ali1535_adapter.name),
 512                "SMBus ALI1535 adapter at %04x", ali1535_offset);
 513        return i2c_add_adapter(&ali1535_adapter);
 514}
 515
 516static void ali1535_remove(struct pci_dev *dev)
 517{
 518        i2c_del_adapter(&ali1535_adapter);
 519        release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
 520}
 521
 522static struct pci_driver ali1535_driver = {
 523        .name           = "ali1535_smbus",
 524        .id_table       = ali1535_ids,
 525        .probe          = ali1535_probe,
 526        .remove         = ali1535_remove,
 527};
 528
 529module_pci_driver(ali1535_driver);
 530
 531MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>, "
 532              "Philip Edelbrock <phil@netroedge.com>, "
 533              "Mark D. Studebaker <mdsxyz123@yahoo.com> "
 534              "and Dan Eaton <dan.eaton@rocketlogix.com>");
 535MODULE_DESCRIPTION("ALI1535 SMBus driver");
 536MODULE_LICENSE("GPL");
 537