linux/drivers/i2c/busses/i2c-ali15x3.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3    Copyright (c) 1999  Frodo Looijaard <frodol@dds.nl> and
   4    Philip Edelbrock <phil@netroedge.com> and
   5    Mark D. Studebaker <mdsxyz123@yahoo.com>
   6
   7*/
   8
   9/*
  10    This is the driver for the SMB Host controller on
  11    Acer Labs Inc. (ALI) M1541 and M1543C South Bridges.
  12
  13    The M1543C is a South bridge for desktop systems.
  14    The M1533 is a South bridge for portable systems.
  15    They are part of the following ALI chipsets:
  16       "Aladdin Pro 2": Includes the M1621 Slot 1 North bridge
  17       with AGP and 100MHz CPU Front Side bus
  18       "Aladdin V": Includes the M1541 Socket 7 North bridge
  19       with AGP and 100MHz CPU Front Side bus
  20       "Aladdin IV": Includes the M1541 Socket 7 North bridge
  21       with host bus up to 83.3 MHz.
  22    For an overview of these chips see http://www.acerlabs.com
  23
  24    The M1533/M1543C devices appear as FOUR separate devices
  25    on the PCI bus. An output of lspci will show something similar
  26    to the following:
  27
  28        00:02.0 USB Controller: Acer Laboratories Inc. M5237
  29        00:03.0 Bridge: Acer Laboratories Inc. M7101
  30        00:07.0 ISA bridge: Acer Laboratories Inc. M1533
  31        00:0f.0 IDE interface: Acer Laboratories Inc. M5229
  32
  33    The SMB controller is part of the 7101 device, which is an
  34    ACPI-compliant Power Management Unit (PMU).
  35
  36    The whole 7101 device has to be enabled for the SMB to work.
  37    You can't just enable the SMB alone.
  38    The SMB and the ACPI have separate I/O spaces.
  39    We make sure that the SMB is enabled. We leave the ACPI alone.
  40
  41    This driver controls the SMB Host only.
  42    The SMB Slave controller on the M15X3 is not enabled.
  43
  44    This driver does not use interrupts.
  45*/
  46
  47/* Note: we assume there can only be one ALI15X3, with one SMBus interface */
  48
  49#include <linux/module.h>
  50#include <linux/pci.h>
  51#include <linux/kernel.h>
  52#include <linux/stddef.h>
  53#include <linux/ioport.h>
  54#include <linux/delay.h>
  55#include <linux/i2c.h>
  56#include <linux/acpi.h>
  57#include <linux/io.h>
  58
  59/* ALI15X3 SMBus address offsets */
  60#define SMBHSTSTS       (0 + ali15x3_smba)
  61#define SMBHSTCNT       (1 + ali15x3_smba)
  62#define SMBHSTSTART     (2 + ali15x3_smba)
  63#define SMBHSTCMD       (7 + ali15x3_smba)
  64#define SMBHSTADD       (3 + ali15x3_smba)
  65#define SMBHSTDAT0      (4 + ali15x3_smba)
  66#define SMBHSTDAT1      (5 + ali15x3_smba)
  67#define SMBBLKDAT       (6 + ali15x3_smba)
  68
  69/* PCI Address Constants */
  70#define SMBCOM          0x004
  71#define SMBBA           0x014
  72#define SMBATPC         0x05B   /* used to unlock xxxBA registers */
  73#define SMBHSTCFG       0x0E0
  74#define SMBSLVC         0x0E1
  75#define SMBCLK          0x0E2
  76#define SMBREV          0x008
  77
  78/* Other settings */
  79#define MAX_TIMEOUT             200     /* times 1/100 sec */
  80#define ALI15X3_SMB_IOSIZE      32
  81
  82/* this is what the Award 1004 BIOS sets them to on a ASUS P5A MB.
  83   We don't use these here. If the bases aren't set to some value we
  84   tell user to upgrade BIOS and we fail.
  85*/
  86#define ALI15X3_SMB_DEFAULTBASE 0xE800
  87
  88/* ALI15X3 address lock bits */
  89#define ALI15X3_LOCK            0x06
  90
  91/* ALI15X3 command constants */
  92#define ALI15X3_ABORT           0x02
  93#define ALI15X3_T_OUT           0x04
  94#define ALI15X3_QUICK           0x00
  95#define ALI15X3_BYTE            0x10
  96#define ALI15X3_BYTE_DATA       0x20
  97#define ALI15X3_WORD_DATA       0x30
  98#define ALI15X3_BLOCK_DATA      0x40
  99#define ALI15X3_BLOCK_CLR       0x80
 100
 101/* ALI15X3 status register bits */
 102#define ALI15X3_STS_IDLE        0x04
 103#define ALI15X3_STS_BUSY        0x08
 104#define ALI15X3_STS_DONE        0x10
 105#define ALI15X3_STS_DEV         0x20    /* device error */
 106#define ALI15X3_STS_COLL        0x40    /* collision or no response */
 107#define ALI15X3_STS_TERM        0x80    /* terminated by abort */
 108#define ALI15X3_STS_ERR         0xE0    /* all the bad error bits */
 109
 110
 111/* If force_addr is set to anything different from 0, we forcibly enable
 112   the device at the given address. */
 113static u16 force_addr;
 114module_param_hw(force_addr, ushort, ioport, 0);
 115MODULE_PARM_DESC(force_addr,
 116                 "Initialize the base address of the i2c controller");
 117
 118static struct pci_driver ali15x3_driver;
 119static unsigned short ali15x3_smba;
 120
 121static int ali15x3_setup(struct pci_dev *ALI15X3_dev)
 122{
 123        u16 a;
 124        unsigned char temp;
 125
 126        /* Check the following things:
 127                - SMB I/O address is initialized
 128                - Device is enabled
 129                - We can use the addresses
 130        */
 131
 132        /* Unlock the register.
 133           The data sheet says that the address registers are read-only
 134           if the lock bits are 1, but in fact the address registers
 135           are zero unless you clear the lock bits.
 136        */
 137        pci_read_config_byte(ALI15X3_dev, SMBATPC, &temp);
 138        if (temp & ALI15X3_LOCK) {
 139                temp &= ~ALI15X3_LOCK;
 140                pci_write_config_byte(ALI15X3_dev, SMBATPC, temp);
 141        }
 142
 143        /* Determine the address of the SMBus area */
 144        pci_read_config_word(ALI15X3_dev, SMBBA, &ali15x3_smba);
 145        ali15x3_smba &= (0xffff & ~(ALI15X3_SMB_IOSIZE - 1));
 146        if (ali15x3_smba == 0 && force_addr == 0) {
 147                dev_err(&ALI15X3_dev->dev, "ALI15X3_smb region uninitialized "
 148                        "- upgrade BIOS or use force_addr=0xaddr\n");
 149                return -ENODEV;
 150        }
 151
 152        if(force_addr)
 153                ali15x3_smba = force_addr & ~(ALI15X3_SMB_IOSIZE - 1);
 154
 155        if (acpi_check_region(ali15x3_smba, ALI15X3_SMB_IOSIZE,
 156                              ali15x3_driver.name))
 157                return -EBUSY;
 158
 159        if (!request_region(ali15x3_smba, ALI15X3_SMB_IOSIZE,
 160                            ali15x3_driver.name)) {
 161                dev_err(&ALI15X3_dev->dev,
 162                        "ALI15X3_smb region 0x%x already in use!\n",
 163                        ali15x3_smba);
 164                return -ENODEV;
 165        }
 166
 167        if(force_addr) {
 168                dev_info(&ALI15X3_dev->dev, "forcing ISA address 0x%04X\n",
 169                        ali15x3_smba);
 170                if (PCIBIOS_SUCCESSFUL != pci_write_config_word(ALI15X3_dev,
 171                                                                SMBBA,
 172                                                                ali15x3_smba))
 173                        goto error;
 174                if (PCIBIOS_SUCCESSFUL != pci_read_config_word(ALI15X3_dev,
 175                                                                SMBBA, &a))
 176                        goto error;
 177                if ((a & ~(ALI15X3_SMB_IOSIZE - 1)) != ali15x3_smba) {
 178                        /* make sure it works */
 179                        dev_err(&ALI15X3_dev->dev,
 180                                "force address failed - not supported?\n");
 181                        goto error;
 182                }
 183        }
 184        /* check if whole device is enabled */
 185        pci_read_config_byte(ALI15X3_dev, SMBCOM, &temp);
 186        if ((temp & 1) == 0) {
 187                dev_info(&ALI15X3_dev->dev, "enabling SMBus device\n");
 188                pci_write_config_byte(ALI15X3_dev, SMBCOM, temp | 0x01);
 189        }
 190
 191        /* Is SMB Host controller enabled? */
 192        pci_read_config_byte(ALI15X3_dev, SMBHSTCFG, &temp);
 193        if ((temp & 1) == 0) {
 194                dev_info(&ALI15X3_dev->dev, "enabling SMBus controller\n");
 195                pci_write_config_byte(ALI15X3_dev, SMBHSTCFG, temp | 0x01);
 196        }
 197
 198        /* set SMB clock to 74KHz as recommended in data sheet */
 199        pci_write_config_byte(ALI15X3_dev, SMBCLK, 0x20);
 200
 201        /*
 202          The interrupt routing for SMB is set up in register 0x77 in the
 203          1533 ISA Bridge device, NOT in the 7101 device.
 204          Don't bother with finding the 1533 device and reading the register.
 205        if ((....... & 0x0F) == 1)
 206                dev_dbg(&ALI15X3_dev->dev, "ALI15X3 using Interrupt 9 for SMBus.\n");
 207        */
 208        pci_read_config_byte(ALI15X3_dev, SMBREV, &temp);
 209        dev_dbg(&ALI15X3_dev->dev, "SMBREV = 0x%X\n", temp);
 210        dev_dbg(&ALI15X3_dev->dev, "iALI15X3_smba = 0x%X\n", ali15x3_smba);
 211
 212        return 0;
 213error:
 214        release_region(ali15x3_smba, ALI15X3_SMB_IOSIZE);
 215        return -ENODEV;
 216}
 217
 218/* Another internally used function */
 219static int ali15x3_transaction(struct i2c_adapter *adap)
 220{
 221        int temp;
 222        int result = 0;
 223        int timeout = 0;
 224
 225        dev_dbg(&adap->dev, "Transaction (pre): STS=%02x, CNT=%02x, CMD=%02x, "
 226                "ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTSTS),
 227                inb_p(SMBHSTCNT), inb_p(SMBHSTCMD), inb_p(SMBHSTADD),
 228                inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
 229
 230        /* get status */
 231        temp = inb_p(SMBHSTSTS);
 232
 233        /* Make sure the SMBus host is ready to start transmitting */
 234        /* Check the busy bit first */
 235        if (temp & ALI15X3_STS_BUSY) {
 236        /*
 237           If the host controller is still busy, it may have timed out in the
 238           previous transaction, resulting in a "SMBus Timeout" Dev.
 239           I've tried the following to reset a stuck busy bit.
 240                1. Reset the controller with an ABORT command.
 241                   (this doesn't seem to clear the controller if an external
 242                   device is hung)
 243                2. Reset the controller and the other SMBus devices with a
 244                   T_OUT command.  (this clears the host busy bit if an
 245                   external device is hung, but it comes back upon a new access
 246                   to a device)
 247                3. Disable and reenable the controller in SMBHSTCFG
 248           Worst case, nothing seems to work except power reset.
 249        */
 250        /* Abort - reset the host controller */
 251        /*
 252           Try resetting entire SMB bus, including other devices -
 253           This may not work either - it clears the BUSY bit but
 254           then the BUSY bit may come back on when you try and use the chip again.
 255           If that's the case you are stuck.
 256        */
 257                dev_info(&adap->dev, "Resetting entire SMB Bus to "
 258                        "clear busy condition (%02x)\n", temp);
 259                outb_p(ALI15X3_T_OUT, SMBHSTCNT);
 260                temp = inb_p(SMBHSTSTS);
 261        }
 262
 263        /* now check the error bits and the busy bit */
 264        if (temp & (ALI15X3_STS_ERR | ALI15X3_STS_BUSY)) {
 265                /* do a clear-on-write */
 266                outb_p(0xFF, SMBHSTSTS);
 267                if ((temp = inb_p(SMBHSTSTS)) &
 268                    (ALI15X3_STS_ERR | ALI15X3_STS_BUSY)) {
 269                        /* this is probably going to be correctable only by a power reset
 270                           as one of the bits now appears to be stuck */
 271                        /* This may be a bus or device with electrical problems. */
 272                        dev_err(&adap->dev, "SMBus reset failed! (0x%02x) - "
 273                                "controller or device on bus is probably hung\n",
 274                                temp);
 275                        return -EBUSY;
 276                }
 277        } else {
 278                /* check and clear done bit */
 279                if (temp & ALI15X3_STS_DONE) {
 280                        outb_p(temp, SMBHSTSTS);
 281                }
 282        }
 283
 284        /* start the transaction by writing anything to the start register */
 285        outb_p(0xFF, SMBHSTSTART);
 286
 287        /* We will always wait for a fraction of a second! */
 288        timeout = 0;
 289        do {
 290                msleep(1);
 291                temp = inb_p(SMBHSTSTS);
 292        } while ((!(temp & (ALI15X3_STS_ERR | ALI15X3_STS_DONE)))
 293                 && (timeout++ < MAX_TIMEOUT));
 294
 295        /* If the SMBus is still busy, we give up */
 296        if (timeout > MAX_TIMEOUT) {
 297                result = -ETIMEDOUT;
 298                dev_err(&adap->dev, "SMBus Timeout!\n");
 299        }
 300
 301        if (temp & ALI15X3_STS_TERM) {
 302                result = -EIO;
 303                dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
 304        }
 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.
 310          This means that bus collisions go unreported.
 311        */
 312        if (temp & ALI15X3_STS_COLL) {
 313                result = -ENXIO;
 314                dev_dbg(&adap->dev,
 315                        "Error: no response or bus collision ADD=%02x\n",
 316                        inb_p(SMBHSTADD));
 317        }
 318
 319        /* haven't ever seen this */
 320        if (temp & ALI15X3_STS_DEV) {
 321                result = -EIO;
 322                dev_err(&adap->dev, "Error: device error\n");
 323        }
 324        dev_dbg(&adap->dev, "Transaction (post): STS=%02x, CNT=%02x, CMD=%02x, "
 325                "ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTSTS),
 326                inb_p(SMBHSTCNT), inb_p(SMBHSTCMD), inb_p(SMBHSTADD),
 327                inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
 328        return result;
 329}
 330
 331/* Return negative errno on error. */
 332static s32 ali15x3_access(struct i2c_adapter * adap, u16 addr,
 333                   unsigned short flags, char read_write, u8 command,
 334                   int size, union i2c_smbus_data * data)
 335{
 336        int i, len;
 337        int temp;
 338        int timeout;
 339
 340        /* clear all the bits (clear-on-write) */
 341        outb_p(0xFF, SMBHSTSTS);
 342        /* make sure SMBus is idle */
 343        temp = inb_p(SMBHSTSTS);
 344        for (timeout = 0;
 345             (timeout < MAX_TIMEOUT) && !(temp & ALI15X3_STS_IDLE);
 346             timeout++) {
 347                msleep(1);
 348                temp = inb_p(SMBHSTSTS);
 349        }
 350        if (timeout >= MAX_TIMEOUT) {
 351                dev_err(&adap->dev, "Idle wait Timeout! STS=0x%02x\n", temp);
 352        }
 353
 354        switch (size) {
 355        case I2C_SMBUS_QUICK:
 356                outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 357                       SMBHSTADD);
 358                size = ALI15X3_QUICK;
 359                break;
 360        case I2C_SMBUS_BYTE:
 361                outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 362                       SMBHSTADD);
 363                if (read_write == I2C_SMBUS_WRITE)
 364                        outb_p(command, SMBHSTCMD);
 365                size = ALI15X3_BYTE;
 366                break;
 367        case I2C_SMBUS_BYTE_DATA:
 368                outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 369                       SMBHSTADD);
 370                outb_p(command, SMBHSTCMD);
 371                if (read_write == I2C_SMBUS_WRITE)
 372                        outb_p(data->byte, SMBHSTDAT0);
 373                size = ALI15X3_BYTE_DATA;
 374                break;
 375        case I2C_SMBUS_WORD_DATA:
 376                outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 377                       SMBHSTADD);
 378                outb_p(command, SMBHSTCMD);
 379                if (read_write == I2C_SMBUS_WRITE) {
 380                        outb_p(data->word & 0xff, SMBHSTDAT0);
 381                        outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
 382                }
 383                size = ALI15X3_WORD_DATA;
 384                break;
 385        case I2C_SMBUS_BLOCK_DATA:
 386                outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 387                       SMBHSTADD);
 388                outb_p(command, SMBHSTCMD);
 389                if (read_write == I2C_SMBUS_WRITE) {
 390                        len = data->block[0];
 391                        if (len < 0) {
 392                                len = 0;
 393                                data->block[0] = len;
 394                        }
 395                        if (len > 32) {
 396                                len = 32;
 397                                data->block[0] = len;
 398                        }
 399                        outb_p(len, SMBHSTDAT0);
 400                        /* Reset SMBBLKDAT */
 401                        outb_p(inb_p(SMBHSTCNT) | ALI15X3_BLOCK_CLR, SMBHSTCNT);
 402                        for (i = 1; i <= len; i++)
 403                                outb_p(data->block[i], SMBBLKDAT);
 404                }
 405                size = ALI15X3_BLOCK_DATA;
 406                break;
 407        default:
 408                dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
 409                return -EOPNOTSUPP;
 410        }
 411
 412        outb_p(size, SMBHSTCNT);        /* output command */
 413
 414        temp = ali15x3_transaction(adap);
 415        if (temp)
 416                return temp;
 417
 418        if ((read_write == I2C_SMBUS_WRITE) || (size == ALI15X3_QUICK))
 419                return 0;
 420
 421
 422        switch (size) {
 423        case ALI15X3_BYTE:      /* Result put in SMBHSTDAT0 */
 424                data->byte = inb_p(SMBHSTDAT0);
 425                break;
 426        case ALI15X3_BYTE_DATA:
 427                data->byte = inb_p(SMBHSTDAT0);
 428                break;
 429        case ALI15X3_WORD_DATA:
 430                data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
 431                break;
 432        case ALI15X3_BLOCK_DATA:
 433                len = inb_p(SMBHSTDAT0);
 434                if (len > 32)
 435                        len = 32;
 436                data->block[0] = len;
 437                /* Reset SMBBLKDAT */
 438                outb_p(inb_p(SMBHSTCNT) | ALI15X3_BLOCK_CLR, SMBHSTCNT);
 439                for (i = 1; i <= data->block[0]; i++) {
 440                        data->block[i] = inb_p(SMBBLKDAT);
 441                        dev_dbg(&adap->dev, "Blk: len=%d, i=%d, data=%02x\n",
 442                                len, i, data->block[i]);
 443                }
 444                break;
 445        }
 446        return 0;
 447}
 448
 449static u32 ali15x3_func(struct i2c_adapter *adapter)
 450{
 451        return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 452            I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 453            I2C_FUNC_SMBUS_BLOCK_DATA;
 454}
 455
 456static const struct i2c_algorithm smbus_algorithm = {
 457        .smbus_xfer     = ali15x3_access,
 458        .functionality  = ali15x3_func,
 459};
 460
 461static struct i2c_adapter ali15x3_adapter = {
 462        .owner          = THIS_MODULE,
 463        .class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
 464        .algo           = &smbus_algorithm,
 465};
 466
 467static const struct pci_device_id ali15x3_ids[] = {
 468        { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
 469        { 0, }
 470};
 471
 472MODULE_DEVICE_TABLE (pci, ali15x3_ids);
 473
 474static int ali15x3_probe(struct pci_dev *dev, const struct pci_device_id *id)
 475{
 476        if (ali15x3_setup(dev)) {
 477                dev_err(&dev->dev,
 478                        "ALI15X3 not detected, module not inserted.\n");
 479                return -ENODEV;
 480        }
 481
 482        /* set up the sysfs linkage to our parent device */
 483        ali15x3_adapter.dev.parent = &dev->dev;
 484
 485        snprintf(ali15x3_adapter.name, sizeof(ali15x3_adapter.name),
 486                "SMBus ALI15X3 adapter at %04x", ali15x3_smba);
 487        return i2c_add_adapter(&ali15x3_adapter);
 488}
 489
 490static void ali15x3_remove(struct pci_dev *dev)
 491{
 492        i2c_del_adapter(&ali15x3_adapter);
 493        release_region(ali15x3_smba, ALI15X3_SMB_IOSIZE);
 494}
 495
 496static struct pci_driver ali15x3_driver = {
 497        .name           = "ali15x3_smbus",
 498        .id_table       = ali15x3_ids,
 499        .probe          = ali15x3_probe,
 500        .remove         = ali15x3_remove,
 501};
 502
 503module_pci_driver(ali15x3_driver);
 504
 505MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
 506MODULE_AUTHOR("Philip Edelbrock <phil@netroedge.com>");
 507MODULE_AUTHOR("Mark D. Studebaker <mdsxyz123@yahoo.com>");
 508MODULE_DESCRIPTION("ALI15X3 SMBus driver");
 509MODULE_LICENSE("GPL");
 510