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 *  You should have received a copy of the GNU General Public License
  19 *  along with this program; if not, write to the Free Software
  20 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21*/
  22
  23/*
  24    This is the driver for the SMB Host controller on
  25    Acer Labs Inc. (ALI) M1535 South Bridge.
  26
  27    The M1535 is a South bridge for portable systems.
  28    It is very similar to the M15x3 South bridges also produced
  29    by Acer Labs Inc.  Some of the registers within the part
  30    have moved and some have been redefined slightly. Additionally,
  31    the sequencing of the SMBus transactions has been modified
  32    to be more consistent with the sequencing recommended by
  33    the manufacturer and observed through testing.  These
  34    changes are reflected in this driver and can be identified
  35    by comparing this driver to the i2c-ali15x3 driver.
  36    For an overview of these chips see http://www.acerlabs.com
  37
  38    The SMB controller is part of the 7101 device, which is an
  39    ACPI-compliant Power Management Unit (PMU).
  40
  41    The whole 7101 device has to be enabled for the SMB to work.
  42    You can't just enable the SMB alone.
  43    The SMB and the ACPI have separate I/O spaces.
  44    We make sure that the SMB is enabled. We leave the ACPI alone.
  45
  46    This driver controls the SMB Host only.
  47
  48    This driver does not use interrupts.
  49*/
  50
  51
  52/* Note: we assume there can only be one ALI1535, with one SMBus interface */
  53
  54#include <linux/module.h>
  55#include <linux/pci.h>
  56#include <linux/kernel.h>
  57#include <linux/stddef.h>
  58#include <linux/delay.h>
  59#include <linux/ioport.h>
  60#include <linux/i2c.h>
  61#include <linux/init.h>
  62#include <linux/acpi.h>
  63#include <linux/io.h>
  64
  65
  66/* ALI1535 SMBus address offsets */
  67#define SMBHSTSTS       (0 + ali1535_smba)
  68#define SMBHSTTYP       (1 + ali1535_smba)
  69#define SMBHSTPORT      (2 + ali1535_smba)
  70#define SMBHSTCMD       (7 + ali1535_smba)
  71#define SMBHSTADD       (3 + ali1535_smba)
  72#define SMBHSTDAT0      (4 + ali1535_smba)
  73#define SMBHSTDAT1      (5 + ali1535_smba)
  74#define SMBBLKDAT       (6 + ali1535_smba)
  75
  76/* PCI Address Constants */
  77#define SMBCOM          0x004
  78#define SMBREV          0x008
  79#define SMBCFG          0x0D1
  80#define SMBBA           0x0E2
  81#define SMBHSTCFG       0x0F0
  82#define SMBCLK          0x0F2
  83
  84/* Other settings */
  85#define MAX_TIMEOUT             500     /* times 1/100 sec */
  86#define ALI1535_SMB_IOSIZE      32
  87
  88#define ALI1535_SMB_DEFAULTBASE 0x8040
  89
  90/* ALI1535 address lock bits */
  91#define ALI1535_LOCK            0x06    /* dwe */
  92
  93/* ALI1535 command constants */
  94#define ALI1535_QUICK           0x00
  95#define ALI1535_BYTE            0x10
  96#define ALI1535_BYTE_DATA       0x20
  97#define ALI1535_WORD_DATA       0x30
  98#define ALI1535_BLOCK_DATA      0x40
  99#define ALI1535_I2C_READ        0x60
 100
 101#define ALI1535_DEV10B_EN       0x80    /* Enable 10-bit addressing in  */
 102                                        /*  I2C read                    */
 103#define ALI1535_T_OUT           0x08    /* Time-out Command (write)     */
 104#define ALI1535_A_HIGH_BIT9     0x08    /* Bit 9 of 10-bit address in   */
 105                                        /* Alert-Response-Address       */
 106                                        /* (read)                       */
 107#define ALI1535_KILL            0x04    /* Kill Command (write)         */
 108#define ALI1535_A_HIGH_BIT8     0x04    /* Bit 8 of 10-bit address in   */
 109                                        /*  Alert-Response-Address      */
 110                                        /*  (read)                      */
 111
 112#define ALI1535_D_HI_MASK       0x03    /* Mask for isolating bits 9-8  */
 113                                        /*  of 10-bit address in I2C    */
 114                                        /*  Read Command                */
 115
 116/* ALI1535 status register bits */
 117#define ALI1535_STS_IDLE        0x04
 118#define ALI1535_STS_BUSY        0x08    /* host busy */
 119#define ALI1535_STS_DONE        0x10    /* transaction complete */
 120#define ALI1535_STS_DEV         0x20    /* device error */
 121#define ALI1535_STS_BUSERR      0x40    /* bus error    */
 122#define ALI1535_STS_FAIL        0x80    /* failed bus transaction */
 123#define ALI1535_STS_ERR         0xE0    /* all the bad error bits */
 124
 125#define ALI1535_BLOCK_CLR       0x04    /* reset block data index */
 126
 127/* ALI1535 device address register bits */
 128#define ALI1535_RD_ADDR         0x01    /* Read/Write Bit in Device     */
 129                                        /*  Address field               */
 130                                        /*  -> Write = 0                */
 131                                        /*  -> Read  = 1                */
 132#define ALI1535_SMBIO_EN        0x04    /* SMB I/O Space enable         */
 133
 134static struct pci_driver ali1535_driver;
 135static unsigned long ali1535_smba;
 136static unsigned short ali1535_offset;
 137
 138/* Detect whether a ALI1535 can be found, and initialize it, where necessary.
 139   Note the differences between kernels with the old PCI BIOS interface and
 140   newer kernels with the real PCI interface. In compat.h some things are
 141   defined to make the transition easier. */
 142static int ali1535_setup(struct pci_dev *dev)
 143{
 144        int retval;
 145        unsigned char temp;
 146
 147        /* Check the following things:
 148                - SMB I/O address is initialized
 149                - Device is enabled
 150                - We can use the addresses
 151        */
 152
 153        retval = pci_enable_device(dev);
 154        if (retval) {
 155                dev_err(&dev->dev, "ALI1535_smb can't enable device\n");
 156                goto exit;
 157        }
 158
 159        /* Determine the address of the SMBus area */
 160        pci_read_config_word(dev, SMBBA, &ali1535_offset);
 161        dev_dbg(&dev->dev, "ALI1535_smb is at offset 0x%04x\n", ali1535_offset);
 162        ali1535_offset &= (0xffff & ~(ALI1535_SMB_IOSIZE - 1));
 163        if (ali1535_offset == 0) {
 164                dev_warn(&dev->dev,
 165                        "ALI1535_smb region uninitialized - upgrade BIOS?\n");
 166                retval = -ENODEV;
 167                goto exit;
 168        }
 169
 170        if (pci_resource_flags(dev, 0) & IORESOURCE_IO)
 171                ali1535_smba = pci_resource_start(dev, 0) + ali1535_offset;
 172        else
 173                ali1535_smba = ali1535_offset;
 174
 175        retval = acpi_check_region(ali1535_smba, ALI1535_SMB_IOSIZE,
 176                                   ali1535_driver.name);
 177        if (retval)
 178                goto exit;
 179
 180        if (!request_region(ali1535_smba, ALI1535_SMB_IOSIZE,
 181                            ali1535_driver.name)) {
 182                dev_err(&dev->dev, "ALI1535_smb region 0x%lx already in use!\n",
 183                        ali1535_smba);
 184                retval = -EBUSY;
 185                goto exit;
 186        }
 187
 188        /* check if whole device is enabled */
 189        pci_read_config_byte(dev, SMBCFG, &temp);
 190        if ((temp & ALI1535_SMBIO_EN) == 0) {
 191                dev_err(&dev->dev, "SMB device not enabled - upgrade BIOS?\n");
 192                retval = -ENODEV;
 193                goto exit_free;
 194        }
 195
 196        /* Is SMB Host controller enabled? */
 197        pci_read_config_byte(dev, SMBHSTCFG, &temp);
 198        if ((temp & 1) == 0) {
 199                dev_err(&dev->dev, "SMBus controller not enabled - upgrade BIOS?\n");
 200                retval = -ENODEV;
 201                goto exit_free;
 202        }
 203
 204        /* set SMB clock to 74KHz as recommended in data sheet */
 205        pci_write_config_byte(dev, SMBCLK, 0x20);
 206
 207        /*
 208          The interrupt routing for SMB is set up in register 0x77 in the
 209          1533 ISA Bridge device, NOT in the 7101 device.
 210          Don't bother with finding the 1533 device and reading the register.
 211        if ((....... & 0x0F) == 1)
 212                dev_dbg(&dev->dev, "ALI1535 using Interrupt 9 for SMBus.\n");
 213        */
 214        pci_read_config_byte(dev, SMBREV, &temp);
 215        dev_dbg(&dev->dev, "SMBREV = 0x%X\n", temp);
 216        dev_dbg(&dev->dev, "ALI1535_smba = 0x%lx\n", ali1535_smba);
 217
 218        return 0;
 219
 220exit_free:
 221        release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
 222exit:
 223        return retval;
 224}
 225
 226static int ali1535_transaction(struct i2c_adapter *adap)
 227{
 228        int temp;
 229        int result = 0;
 230        int timeout = 0;
 231
 232        dev_dbg(&adap->dev, "Transaction (pre): STS=%02x, TYP=%02x, "
 233                "CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
 234                inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
 235                inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
 236
 237        /* get status */
 238        temp = inb_p(SMBHSTSTS);
 239
 240        /* Make sure the SMBus host is ready to start transmitting */
 241        /* Check the busy bit first */
 242        if (temp & ALI1535_STS_BUSY) {
 243                /* If the host controller is still busy, it may have timed out
 244                 * in the previous transaction, resulting in a "SMBus Timeout"
 245                 * printk.  I've tried the following to reset a stuck busy bit.
 246                 *   1. Reset the controller with an KILL command. (this
 247                 *      doesn't seem to clear the controller if an external
 248                 *      device is hung)
 249                 *   2. Reset the controller and the other SMBus devices with a
 250                 *      T_OUT command. (this clears the host busy bit if an
 251                 *      external device is hung, but it comes back upon a new
 252                 *      access to a device)
 253                 *   3. Disable and reenable the controller in SMBHSTCFG. Worst
 254                 *      case, nothing seems to work except power reset.
 255                 */
 256
 257                /* Try resetting entire SMB bus, including other devices - This
 258                 * may not work either - it clears the BUSY bit but then the
 259                 * BUSY bit may come back on when you try and use the chip
 260                 * again.  If that's the case you are stuck.
 261                 */
 262                dev_info(&adap->dev,
 263                        "Resetting entire SMB Bus to clear busy condition (%02x)\n",
 264                        temp);
 265                outb_p(ALI1535_T_OUT, SMBHSTTYP);
 266                temp = inb_p(SMBHSTSTS);
 267        }
 268
 269        /* now check the error bits and the busy bit */
 270        if (temp & (ALI1535_STS_ERR | ALI1535_STS_BUSY)) {
 271                /* do a clear-on-write */
 272                outb_p(0xFF, SMBHSTSTS);
 273                temp = inb_p(SMBHSTSTS);
 274                if (temp & (ALI1535_STS_ERR | ALI1535_STS_BUSY)) {
 275                        /* This is probably going to be correctable only by a
 276                         * power reset as one of the bits now appears to be
 277                         * stuck */
 278                        /* This may be a bus or device with electrical problems. */
 279                        dev_err(&adap->dev,
 280                                "SMBus reset failed! (0x%02x) - controller or "
 281                                "device on bus is probably hung\n", temp);
 282                        return -EBUSY;
 283                }
 284        } else {
 285                /* check and clear done bit */
 286                if (temp & ALI1535_STS_DONE)
 287                        outb_p(temp, SMBHSTSTS);
 288        }
 289
 290        /* start the transaction by writing anything to the start register */
 291        outb_p(0xFF, SMBHSTPORT);
 292
 293        /* We will always wait for a fraction of a second! */
 294        timeout = 0;
 295        do {
 296                usleep_range(1000, 2000);
 297                temp = inb_p(SMBHSTSTS);
 298        } while (((temp & ALI1535_STS_BUSY) && !(temp & ALI1535_STS_IDLE))
 299                 && (timeout++ < MAX_TIMEOUT));
 300
 301        /* If the SMBus is still busy, we give up */
 302        if (timeout > MAX_TIMEOUT) {
 303                result = -ETIMEDOUT;
 304                dev_err(&adap->dev, "SMBus Timeout!\n");
 305        }
 306
 307        if (temp & ALI1535_STS_FAIL) {
 308                result = -EIO;
 309                dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
 310        }
 311
 312        /* Unfortunately the ALI SMB controller maps "no response" and "bus
 313         * collision" into a single bit. No response is the usual case so don't
 314         * do a printk.  This means that bus collisions go unreported.
 315         */
 316        if (temp & ALI1535_STS_BUSERR) {
 317                result = -ENXIO;
 318                dev_dbg(&adap->dev,
 319                        "Error: no response or bus collision ADD=%02x\n",
 320                        inb_p(SMBHSTADD));
 321        }
 322
 323        /* haven't ever seen this */
 324        if (temp & ALI1535_STS_DEV) {
 325                result = -EIO;
 326                dev_err(&adap->dev, "Error: device error\n");
 327        }
 328
 329        /* check to see if the "command complete" indication is set */
 330        if (!(temp & ALI1535_STS_DONE)) {
 331                result = -ETIMEDOUT;
 332                dev_err(&adap->dev, "Error: command never completed\n");
 333        }
 334
 335        dev_dbg(&adap->dev, "Transaction (post): STS=%02x, TYP=%02x, "
 336                "CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
 337                inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
 338                inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
 339
 340        /* take consequent actions for error conditions */
 341        if (!(temp & ALI1535_STS_DONE)) {
 342                /* issue "kill" to reset host controller */
 343                outb_p(ALI1535_KILL, SMBHSTTYP);
 344                outb_p(0xFF, SMBHSTSTS);
 345        } else if (temp & ALI1535_STS_ERR) {
 346                /* issue "timeout" to reset all devices on bus */
 347                outb_p(ALI1535_T_OUT, SMBHSTTYP);
 348                outb_p(0xFF, SMBHSTSTS);
 349        }
 350
 351        return result;
 352}
 353
 354/* Return negative errno on error. */
 355static s32 ali1535_access(struct i2c_adapter *adap, u16 addr,
 356                          unsigned short flags, char read_write, u8 command,
 357                          int size, union i2c_smbus_data *data)
 358{
 359        int i, len;
 360        int temp;
 361        int timeout;
 362        s32 result = 0;
 363
 364        /* make sure SMBus is idle */
 365        temp = inb_p(SMBHSTSTS);
 366        for (timeout = 0;
 367             (timeout < MAX_TIMEOUT) && !(temp & ALI1535_STS_IDLE);
 368             timeout++) {
 369                usleep_range(1000, 2000);
 370                temp = inb_p(SMBHSTSTS);
 371        }
 372        if (timeout >= MAX_TIMEOUT)
 373                dev_warn(&adap->dev, "Idle wait Timeout! STS=0x%02x\n", temp);
 374
 375        /* clear status register (clear-on-write) */
 376        outb_p(0xFF, SMBHSTSTS);
 377
 378        switch (size) {
 379        case I2C_SMBUS_QUICK:
 380                outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 381                       SMBHSTADD);
 382                size = ALI1535_QUICK;
 383                outb_p(size, SMBHSTTYP);        /* output command */
 384                break;
 385        case I2C_SMBUS_BYTE:
 386                outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 387                       SMBHSTADD);
 388                size = ALI1535_BYTE;
 389                outb_p(size, SMBHSTTYP);        /* output command */
 390                if (read_write == I2C_SMBUS_WRITE)
 391                        outb_p(command, SMBHSTCMD);
 392                break;
 393        case I2C_SMBUS_BYTE_DATA:
 394                outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 395                       SMBHSTADD);
 396                size = ALI1535_BYTE_DATA;
 397                outb_p(size, SMBHSTTYP);        /* output command */
 398                outb_p(command, SMBHSTCMD);
 399                if (read_write == I2C_SMBUS_WRITE)
 400                        outb_p(data->byte, SMBHSTDAT0);
 401                break;
 402        case I2C_SMBUS_WORD_DATA:
 403                outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 404                       SMBHSTADD);
 405                size = ALI1535_WORD_DATA;
 406                outb_p(size, SMBHSTTYP);        /* output command */
 407                outb_p(command, SMBHSTCMD);
 408                if (read_write == I2C_SMBUS_WRITE) {
 409                        outb_p(data->word & 0xff, SMBHSTDAT0);
 410                        outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
 411                }
 412                break;
 413        case I2C_SMBUS_BLOCK_DATA:
 414                outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 415                       SMBHSTADD);
 416                size = ALI1535_BLOCK_DATA;
 417                outb_p(size, SMBHSTTYP);        /* output command */
 418                outb_p(command, SMBHSTCMD);
 419                if (read_write == I2C_SMBUS_WRITE) {
 420                        len = data->block[0];
 421                        if (len < 0) {
 422                                len = 0;
 423                                data->block[0] = len;
 424                        }
 425                        if (len > 32) {
 426                                len = 32;
 427                                data->block[0] = len;
 428                        }
 429                        outb_p(len, SMBHSTDAT0);
 430                        /* Reset SMBBLKDAT */
 431                        outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
 432                        for (i = 1; i <= len; i++)
 433                                outb_p(data->block[i], SMBBLKDAT);
 434                }
 435                break;
 436        default:
 437                dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
 438                result = -EOPNOTSUPP;
 439                goto EXIT;
 440        }
 441
 442        result = ali1535_transaction(adap);
 443        if (result)
 444                goto EXIT;
 445
 446        if ((read_write == I2C_SMBUS_WRITE) || (size == ALI1535_QUICK)) {
 447                result = 0;
 448                goto EXIT;
 449        }
 450
 451        switch (size) {
 452        case ALI1535_BYTE:      /* Result put in SMBHSTDAT0 */
 453                data->byte = inb_p(SMBHSTDAT0);
 454                break;
 455        case ALI1535_BYTE_DATA:
 456                data->byte = inb_p(SMBHSTDAT0);
 457                break;
 458        case ALI1535_WORD_DATA:
 459                data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
 460                break;
 461        case ALI1535_BLOCK_DATA:
 462                len = inb_p(SMBHSTDAT0);
 463                if (len > 32)
 464                        len = 32;
 465                data->block[0] = len;
 466                /* Reset SMBBLKDAT */
 467                outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
 468                for (i = 1; i <= data->block[0]; i++) {
 469                        data->block[i] = inb_p(SMBBLKDAT);
 470                        dev_dbg(&adap->dev, "Blk: len=%d, i=%d, data=%02x\n",
 471                                len, i, data->block[i]);
 472                }
 473                break;
 474        }
 475EXIT:
 476        return result;
 477}
 478
 479
 480static u32 ali1535_func(struct i2c_adapter *adapter)
 481{
 482        return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 483            I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 484            I2C_FUNC_SMBUS_BLOCK_DATA;
 485}
 486
 487static const struct i2c_algorithm smbus_algorithm = {
 488        .smbus_xfer     = ali1535_access,
 489        .functionality  = ali1535_func,
 490};
 491
 492static struct i2c_adapter ali1535_adapter = {
 493        .owner          = THIS_MODULE,
 494        .class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
 495        .algo           = &smbus_algorithm,
 496};
 497
 498static DEFINE_PCI_DEVICE_TABLE(ali1535_ids) = {
 499        { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
 500        { },
 501};
 502
 503MODULE_DEVICE_TABLE(pci, ali1535_ids);
 504
 505static int ali1535_probe(struct pci_dev *dev, const struct pci_device_id *id)
 506{
 507        if (ali1535_setup(dev)) {
 508                dev_warn(&dev->dev,
 509                        "ALI1535 not detected, module not inserted.\n");
 510                return -ENODEV;
 511        }
 512
 513        /* set up the sysfs linkage to our parent device */
 514        ali1535_adapter.dev.parent = &dev->dev;
 515
 516        snprintf(ali1535_adapter.name, sizeof(ali1535_adapter.name),
 517                "SMBus ALI1535 adapter at %04x", ali1535_offset);
 518        return i2c_add_adapter(&ali1535_adapter);
 519}
 520
 521static void ali1535_remove(struct pci_dev *dev)
 522{
 523        i2c_del_adapter(&ali1535_adapter);
 524        release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
 525}
 526
 527static struct pci_driver ali1535_driver = {
 528        .name           = "ali1535_smbus",
 529        .id_table       = ali1535_ids,
 530        .probe          = ali1535_probe,
 531        .remove         = ali1535_remove,
 532};
 533
 534module_pci_driver(ali1535_driver);
 535
 536MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>, "
 537              "Philip Edelbrock <phil@netroedge.com>, "
 538              "Mark D. Studebaker <mdsxyz123@yahoo.com> "
 539              "and Dan Eaton <dan.eaton@rocketlogix.com>");
 540MODULE_DESCRIPTION("ALI1535 SMBus driver");
 541MODULE_LICENSE("GPL");
 542