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

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Copyright (c) 2000  Frodo Looijaard <frodol@dds.nl>,
   4 *                      Philip Edelbrock <phil@netroedge.com>,
   5 *                      Mark D. Studebaker <mdsxyz123@yahoo.com>,
   6 *                      Dan Eaton <dan.eaton@rocketlogix.com> and
   7 *                      Stephen Rousset <stephen.rousset@rocketlogix.com>
   8*/
   9
  10/*
  11    This is the driver for the SMB Host controller on
  12    Acer Labs Inc. (ALI) M1535 South Bridge.
  13
  14    The M1535 is a South bridge for portable systems.
  15    It is very similar to the M15x3 South bridges also produced
  16    by Acer Labs Inc.  Some of the registers within the part
  17    have moved and some have been redefined slightly. Additionally,
  18    the sequencing of the SMBus transactions has been modified
  19    to be more consistent with the sequencing recommended by
  20    the manufacturer and observed through testing.  These
  21    changes are reflected in this driver and can be identified
  22    by comparing this driver to the i2c-ali15x3 driver.
  23    For an overview of these chips see http://www.acerlabs.com
  24
  25    The SMB controller is part of the 7101 device, which is an
  26    ACPI-compliant Power Management Unit (PMU).
  27
  28    The whole 7101 device has to be enabled for the SMB to work.
  29    You can't just enable the SMB alone.
  30    The SMB and the ACPI have separate I/O spaces.
  31    We make sure that the SMB is enabled. We leave the ACPI alone.
  32
  33    This driver controls the SMB Host only.
  34
  35    This driver does not use interrupts.
  36*/
  37
  38
  39/* Note: we assume there can only be one ALI1535, with one SMBus interface */
  40
  41#include <linux/module.h>
  42#include <linux/pci.h>
  43#include <linux/kernel.h>
  44#include <linux/stddef.h>
  45#include <linux/delay.h>
  46#include <linux/ioport.h>
  47#include <linux/i2c.h>
  48#include <linux/acpi.h>
  49#include <linux/io.h>
  50
  51
  52/* ALI1535 SMBus address offsets */
  53#define SMBHSTSTS       (0 + ali1535_smba)
  54#define SMBHSTTYP       (1 + ali1535_smba)
  55#define SMBHSTPORT      (2 + ali1535_smba)
  56#define SMBHSTCMD       (7 + ali1535_smba)
  57#define SMBHSTADD       (3 + ali1535_smba)
  58#define SMBHSTDAT0      (4 + ali1535_smba)
  59#define SMBHSTDAT1      (5 + ali1535_smba)
  60#define SMBBLKDAT       (6 + ali1535_smba)
  61
  62/* PCI Address Constants */
  63#define SMBCOM          0x004
  64#define SMBREV          0x008
  65#define SMBCFG          0x0D1
  66#define SMBBA           0x0E2
  67#define SMBHSTCFG       0x0F0
  68#define SMBCLK          0x0F2
  69
  70/* Other settings */
  71#define MAX_TIMEOUT             500     /* times 1/100 sec */
  72#define ALI1535_SMB_IOSIZE      32
  73
  74#define ALI1535_SMB_DEFAULTBASE 0x8040
  75
  76/* ALI1535 address lock bits */
  77#define ALI1535_LOCK            0x06    /* dwe */
  78
  79/* ALI1535 command constants */
  80#define ALI1535_QUICK           0x00
  81#define ALI1535_BYTE            0x10
  82#define ALI1535_BYTE_DATA       0x20
  83#define ALI1535_WORD_DATA       0x30
  84#define ALI1535_BLOCK_DATA      0x40
  85#define ALI1535_I2C_READ        0x60
  86
  87#define ALI1535_DEV10B_EN       0x80    /* Enable 10-bit addressing in  */
  88                                        /*  I2C read                    */
  89#define ALI1535_T_OUT           0x08    /* Time-out Command (write)     */
  90#define ALI1535_A_HIGH_BIT9     0x08    /* Bit 9 of 10-bit address in   */
  91                                        /* Alert-Response-Address       */
  92                                        /* (read)                       */
  93#define ALI1535_KILL            0x04    /* Kill Command (write)         */
  94#define ALI1535_A_HIGH_BIT8     0x04    /* Bit 8 of 10-bit address in   */
  95                                        /*  Alert-Response-Address      */
  96                                        /*  (read)                      */
  97
  98#define ALI1535_D_HI_MASK       0x03    /* Mask for isolating bits 9-8  */
  99                                        /*  of 10-bit address in I2C    */
 100                                        /*  Read Command                */
 101
 102/* ALI1535 status register bits */
 103#define ALI1535_STS_IDLE        0x04
 104#define ALI1535_STS_BUSY        0x08    /* host busy */
 105#define ALI1535_STS_DONE        0x10    /* transaction complete */
 106#define ALI1535_STS_DEV         0x20    /* device error */
 107#define ALI1535_STS_BUSERR      0x40    /* bus error    */
 108#define ALI1535_STS_FAIL        0x80    /* failed bus transaction */
 109#define ALI1535_STS_ERR         0xE0    /* all the bad error bits */
 110
 111#define ALI1535_BLOCK_CLR       0x04    /* reset block data index */
 112
 113/* ALI1535 device address register bits */
 114#define ALI1535_RD_ADDR         0x01    /* Read/Write Bit in Device     */
 115                                        /*  Address field               */
 116                                        /*  -> Write = 0                */
 117                                        /*  -> Read  = 1                */
 118#define ALI1535_SMBIO_EN        0x04    /* SMB I/O Space enable         */
 119
 120static struct pci_driver ali1535_driver;
 121static unsigned long ali1535_smba;
 122static unsigned short ali1535_offset;
 123
 124/* Detect whether a ALI1535 can be found, and initialize it, where necessary.
 125   Note the differences between kernels with the old PCI BIOS interface and
 126   newer kernels with the real PCI interface. In compat.h some things are
 127   defined to make the transition easier. */
 128static int ali1535_setup(struct pci_dev *dev)
 129{
 130        int retval;
 131        unsigned char temp;
 132
 133        /* Check the following things:
 134                - SMB I/O address is initialized
 135                - Device is enabled
 136                - We can use the addresses
 137        */
 138
 139        retval = pci_enable_device(dev);
 140        if (retval) {
 141                dev_err(&dev->dev, "ALI1535_smb can't enable device\n");
 142                goto exit;
 143        }
 144
 145        /* Determine the address of the SMBus area */
 146        pci_read_config_word(dev, SMBBA, &ali1535_offset);
 147        dev_dbg(&dev->dev, "ALI1535_smb is at offset 0x%04x\n", ali1535_offset);
 148        ali1535_offset &= (0xffff & ~(ALI1535_SMB_IOSIZE - 1));
 149        if (ali1535_offset == 0) {
 150                dev_warn(&dev->dev,
 151                        "ALI1535_smb region uninitialized - upgrade BIOS?\n");
 152                retval = -ENODEV;
 153                goto exit;
 154        }
 155
 156        if (pci_resource_flags(dev, 0) & IORESOURCE_IO)
 157                ali1535_smba = pci_resource_start(dev, 0) + ali1535_offset;
 158        else
 159                ali1535_smba = ali1535_offset;
 160
 161        retval = acpi_check_region(ali1535_smba, ALI1535_SMB_IOSIZE,
 162                                   ali1535_driver.name);
 163        if (retval)
 164                goto exit;
 165
 166        if (!request_region(ali1535_smba, ALI1535_SMB_IOSIZE,
 167                            ali1535_driver.name)) {
 168                dev_err(&dev->dev, "ALI1535_smb region 0x%lx already in use!\n",
 169                        ali1535_smba);
 170                retval = -EBUSY;
 171                goto exit;
 172        }
 173
 174        /* check if whole device is enabled */
 175        pci_read_config_byte(dev, SMBCFG, &temp);
 176        if ((temp & ALI1535_SMBIO_EN) == 0) {
 177                dev_err(&dev->dev, "SMB device not enabled - upgrade BIOS?\n");
 178                retval = -ENODEV;
 179                goto exit_free;
 180        }
 181
 182        /* Is SMB Host controller enabled? */
 183        pci_read_config_byte(dev, SMBHSTCFG, &temp);
 184        if ((temp & 1) == 0) {
 185                dev_err(&dev->dev, "SMBus controller not enabled - upgrade BIOS?\n");
 186                retval = -ENODEV;
 187                goto exit_free;
 188        }
 189
 190        /* set SMB clock to 74KHz as recommended in data sheet */
 191        pci_write_config_byte(dev, SMBCLK, 0x20);
 192
 193        /*
 194          The interrupt routing for SMB is set up in register 0x77 in the
 195          1533 ISA Bridge device, NOT in the 7101 device.
 196          Don't bother with finding the 1533 device and reading the register.
 197        if ((....... & 0x0F) == 1)
 198                dev_dbg(&dev->dev, "ALI1535 using Interrupt 9 for SMBus.\n");
 199        */
 200        pci_read_config_byte(dev, SMBREV, &temp);
 201        dev_dbg(&dev->dev, "SMBREV = 0x%X\n", temp);
 202        dev_dbg(&dev->dev, "ALI1535_smba = 0x%lx\n", ali1535_smba);
 203
 204        return 0;
 205
 206exit_free:
 207        release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
 208exit:
 209        return retval;
 210}
 211
 212static int ali1535_transaction(struct i2c_adapter *adap)
 213{
 214        int temp;
 215        int result = 0;
 216        int timeout = 0;
 217
 218        dev_dbg(&adap->dev, "Transaction (pre): STS=%02x, TYP=%02x, "
 219                "CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
 220                inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
 221                inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
 222
 223        /* get status */
 224        temp = inb_p(SMBHSTSTS);
 225
 226        /* Make sure the SMBus host is ready to start transmitting */
 227        /* Check the busy bit first */
 228        if (temp & ALI1535_STS_BUSY) {
 229                /* If the host controller is still busy, it may have timed out
 230                 * in the previous transaction, resulting in a "SMBus Timeout"
 231                 * printk.  I've tried the following to reset a stuck busy bit.
 232                 *   1. Reset the controller with an KILL command. (this
 233                 *      doesn't seem to clear the controller if an external
 234                 *      device is hung)
 235                 *   2. Reset the controller and the other SMBus devices with a
 236                 *      T_OUT command. (this clears the host busy bit if an
 237                 *      external device is hung, but it comes back upon a new
 238                 *      access to a device)
 239                 *   3. Disable and reenable the controller in SMBHSTCFG. Worst
 240                 *      case, nothing seems to work except power reset.
 241                 */
 242
 243                /* Try resetting entire SMB bus, including other devices - This
 244                 * may not work either - it clears the BUSY bit but then the
 245                 * BUSY bit may come back on when you try and use the chip
 246                 * again.  If that's the case you are stuck.
 247                 */
 248                dev_info(&adap->dev,
 249                        "Resetting entire SMB Bus to clear busy condition (%02x)\n",
 250                        temp);
 251                outb_p(ALI1535_T_OUT, SMBHSTTYP);
 252                temp = inb_p(SMBHSTSTS);
 253        }
 254
 255        /* now check the error bits and the busy bit */
 256        if (temp & (ALI1535_STS_ERR | ALI1535_STS_BUSY)) {
 257                /* do a clear-on-write */
 258                outb_p(0xFF, SMBHSTSTS);
 259                temp = inb_p(SMBHSTSTS);
 260                if (temp & (ALI1535_STS_ERR | ALI1535_STS_BUSY)) {
 261                        /* This is probably going to be correctable only by a
 262                         * power reset as one of the bits now appears to be
 263                         * stuck */
 264                        /* This may be a bus or device with electrical problems. */
 265                        dev_err(&adap->dev,
 266                                "SMBus reset failed! (0x%02x) - controller or "
 267                                "device on bus is probably hung\n", temp);
 268                        return -EBUSY;
 269                }
 270        } else {
 271                /* check and clear done bit */
 272                if (temp & ALI1535_STS_DONE)
 273                        outb_p(temp, SMBHSTSTS);
 274        }
 275
 276        /* start the transaction by writing anything to the start register */
 277        outb_p(0xFF, SMBHSTPORT);
 278
 279        /* We will always wait for a fraction of a second! */
 280        timeout = 0;
 281        do {
 282                usleep_range(1000, 2000);
 283                temp = inb_p(SMBHSTSTS);
 284        } while (((temp & ALI1535_STS_BUSY) && !(temp & ALI1535_STS_IDLE))
 285                 && (timeout++ < MAX_TIMEOUT));
 286
 287        /* If the SMBus is still busy, we give up */
 288        if (timeout > MAX_TIMEOUT) {
 289                result = -ETIMEDOUT;
 290                dev_err(&adap->dev, "SMBus Timeout!\n");
 291        }
 292
 293        if (temp & ALI1535_STS_FAIL) {
 294                result = -EIO;
 295                dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
 296        }
 297
 298        /* Unfortunately the ALI SMB controller maps "no response" and "bus
 299         * collision" into a single bit. No response is the usual case so don't
 300         * do a printk.  This means that bus collisions go unreported.
 301         */
 302        if (temp & ALI1535_STS_BUSERR) {
 303                result = -ENXIO;
 304                dev_dbg(&adap->dev,
 305                        "Error: no response or bus collision ADD=%02x\n",
 306                        inb_p(SMBHSTADD));
 307        }
 308
 309        /* haven't ever seen this */
 310        if (temp & ALI1535_STS_DEV) {
 311                result = -EIO;
 312                dev_err(&adap->dev, "Error: device error\n");
 313        }
 314
 315        /* check to see if the "command complete" indication is set */
 316        if (!(temp & ALI1535_STS_DONE)) {
 317                result = -ETIMEDOUT;
 318                dev_err(&adap->dev, "Error: command never completed\n");
 319        }
 320
 321        dev_dbg(&adap->dev, "Transaction (post): STS=%02x, TYP=%02x, "
 322                "CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
 323                inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
 324                inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
 325
 326        /* take consequent actions for error conditions */
 327        if (!(temp & ALI1535_STS_DONE)) {
 328                /* issue "kill" to reset host controller */
 329                outb_p(ALI1535_KILL, SMBHSTTYP);
 330                outb_p(0xFF, SMBHSTSTS);
 331        } else if (temp & ALI1535_STS_ERR) {
 332                /* issue "timeout" to reset all devices on bus */
 333                outb_p(ALI1535_T_OUT, SMBHSTTYP);
 334                outb_p(0xFF, SMBHSTSTS);
 335        }
 336
 337        return result;
 338}
 339
 340/* Return negative errno on error. */
 341static s32 ali1535_access(struct i2c_adapter *adap, u16 addr,
 342                          unsigned short flags, char read_write, u8 command,
 343                          int size, union i2c_smbus_data *data)
 344{
 345        int i, len;
 346        int temp;
 347        int timeout;
 348        s32 result = 0;
 349
 350        /* make sure SMBus is idle */
 351        temp = inb_p(SMBHSTSTS);
 352        for (timeout = 0;
 353             (timeout < MAX_TIMEOUT) && !(temp & ALI1535_STS_IDLE);
 354             timeout++) {
 355                usleep_range(1000, 2000);
 356                temp = inb_p(SMBHSTSTS);
 357        }
 358        if (timeout >= MAX_TIMEOUT)
 359                dev_warn(&adap->dev, "Idle wait Timeout! STS=0x%02x\n", temp);
 360
 361        /* clear status register (clear-on-write) */
 362        outb_p(0xFF, SMBHSTSTS);
 363
 364        switch (size) {
 365        case I2C_SMBUS_QUICK:
 366                outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 367                       SMBHSTADD);
 368                size = ALI1535_QUICK;
 369                outb_p(size, SMBHSTTYP);        /* output command */
 370                break;
 371        case I2C_SMBUS_BYTE:
 372                outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 373                       SMBHSTADD);
 374                size = ALI1535_BYTE;
 375                outb_p(size, SMBHSTTYP);        /* output command */
 376                if (read_write == I2C_SMBUS_WRITE)
 377                        outb_p(command, SMBHSTCMD);
 378                break;
 379        case I2C_SMBUS_BYTE_DATA:
 380                outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 381                       SMBHSTADD);
 382                size = ALI1535_BYTE_DATA;
 383                outb_p(size, SMBHSTTYP);        /* output command */
 384                outb_p(command, SMBHSTCMD);
 385                if (read_write == I2C_SMBUS_WRITE)
 386                        outb_p(data->byte, SMBHSTDAT0);
 387                break;
 388        case I2C_SMBUS_WORD_DATA:
 389                outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 390                       SMBHSTADD);
 391                size = ALI1535_WORD_DATA;
 392                outb_p(size, SMBHSTTYP);        /* output command */
 393                outb_p(command, SMBHSTCMD);
 394                if (read_write == I2C_SMBUS_WRITE) {
 395                        outb_p(data->word & 0xff, SMBHSTDAT0);
 396                        outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
 397                }
 398                break;
 399        case I2C_SMBUS_BLOCK_DATA:
 400                outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 401                       SMBHSTADD);
 402                size = ALI1535_BLOCK_DATA;
 403                outb_p(size, SMBHSTTYP);        /* output command */
 404                outb_p(command, SMBHSTCMD);
 405                if (read_write == I2C_SMBUS_WRITE) {
 406                        len = data->block[0];
 407                        if (len < 0) {
 408                                len = 0;
 409                                data->block[0] = len;
 410                        }
 411                        if (len > 32) {
 412                                len = 32;
 413                                data->block[0] = len;
 414                        }
 415                        outb_p(len, SMBHSTDAT0);
 416                        /* Reset SMBBLKDAT */
 417                        outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
 418                        for (i = 1; i <= len; i++)
 419                                outb_p(data->block[i], SMBBLKDAT);
 420                }
 421                break;
 422        default:
 423                dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
 424                result = -EOPNOTSUPP;
 425                goto EXIT;
 426        }
 427
 428        result = ali1535_transaction(adap);
 429        if (result)
 430                goto EXIT;
 431
 432        if ((read_write == I2C_SMBUS_WRITE) || (size == ALI1535_QUICK)) {
 433                result = 0;
 434                goto EXIT;
 435        }
 436
 437        switch (size) {
 438        case ALI1535_BYTE:      /* Result put in SMBHSTDAT0 */
 439                data->byte = inb_p(SMBHSTDAT0);
 440                break;
 441        case ALI1535_BYTE_DATA:
 442                data->byte = inb_p(SMBHSTDAT0);
 443                break;
 444        case ALI1535_WORD_DATA:
 445                data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
 446                break;
 447        case ALI1535_BLOCK_DATA:
 448                len = inb_p(SMBHSTDAT0);
 449                if (len > 32)
 450                        len = 32;
 451                data->block[0] = len;
 452                /* Reset SMBBLKDAT */
 453                outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
 454                for (i = 1; i <= data->block[0]; i++) {
 455                        data->block[i] = inb_p(SMBBLKDAT);
 456                        dev_dbg(&adap->dev, "Blk: len=%d, i=%d, data=%02x\n",
 457                                len, i, data->block[i]);
 458                }
 459                break;
 460        }
 461EXIT:
 462        return result;
 463}
 464
 465
 466static u32 ali1535_func(struct i2c_adapter *adapter)
 467{
 468        return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 469            I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 470            I2C_FUNC_SMBUS_BLOCK_DATA;
 471}
 472
 473static const struct i2c_algorithm smbus_algorithm = {
 474        .smbus_xfer     = ali1535_access,
 475        .functionality  = ali1535_func,
 476};
 477
 478static struct i2c_adapter ali1535_adapter = {
 479        .owner          = THIS_MODULE,
 480        .class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
 481        .algo           = &smbus_algorithm,
 482};
 483
 484static const struct pci_device_id ali1535_ids[] = {
 485        { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
 486        { },
 487};
 488
 489MODULE_DEVICE_TABLE(pci, ali1535_ids);
 490
 491static int ali1535_probe(struct pci_dev *dev, const struct pci_device_id *id)
 492{
 493        if (ali1535_setup(dev)) {
 494                dev_warn(&dev->dev,
 495                        "ALI1535 not detected, module not inserted.\n");
 496                return -ENODEV;
 497        }
 498
 499        /* set up the sysfs linkage to our parent device */
 500        ali1535_adapter.dev.parent = &dev->dev;
 501
 502        snprintf(ali1535_adapter.name, sizeof(ali1535_adapter.name),
 503                "SMBus ALI1535 adapter at %04x", ali1535_offset);
 504        return i2c_add_adapter(&ali1535_adapter);
 505}
 506
 507static void ali1535_remove(struct pci_dev *dev)
 508{
 509        i2c_del_adapter(&ali1535_adapter);
 510        release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
 511}
 512
 513static struct pci_driver ali1535_driver = {
 514        .name           = "ali1535_smbus",
 515        .id_table       = ali1535_ids,
 516        .probe          = ali1535_probe,
 517        .remove         = ali1535_remove,
 518};
 519
 520module_pci_driver(ali1535_driver);
 521
 522MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
 523MODULE_AUTHOR("Philip Edelbrock <phil@netroedge.com>");
 524MODULE_AUTHOR("Mark D. Studebaker <mdsxyz123@yahoo.com>");
 525MODULE_AUTHOR("Dan Eaton <dan.eaton@rocketlogix.com>");
 526MODULE_DESCRIPTION("ALI1535 SMBus driver");
 527MODULE_LICENSE("GPL");
 528