linux/drivers/i2c/busses/i2c-amd756.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3    Copyright (c) 1999-2002 Merlin Hughes <merlin@merlin.org>
   4
   5    Shamelessly ripped from i2c-piix4.c:
   6
   7    Copyright (c) 1998, 1999  Frodo Looijaard <frodol@dds.nl> and
   8    Philip Edelbrock <phil@netroedge.com>
   9
  10*/
  11
  12/*
  13    2002-04-08: Added nForce support. (Csaba Halasz)
  14    2002-10-03: Fixed nForce PnP I/O port. (Michael Steil)
  15    2002-12-28: Rewritten into something that resembles a Linux driver (hch)
  16    2003-11-29: Added back AMD8111 removed by the previous rewrite.
  17                (Philip Pokorny)
  18*/
  19
  20/*
  21   Supports AMD756, AMD766, AMD768, AMD8111 and nVidia nForce
  22   Note: we assume there can only be one device, with one SMBus interface.
  23*/
  24
  25#include <linux/module.h>
  26#include <linux/pci.h>
  27#include <linux/kernel.h>
  28#include <linux/delay.h>
  29#include <linux/stddef.h>
  30#include <linux/ioport.h>
  31#include <linux/i2c.h>
  32#include <linux/acpi.h>
  33#include <linux/io.h>
  34
  35/* AMD756 SMBus address offsets */
  36#define SMB_ADDR_OFFSET         0xE0
  37#define SMB_IOSIZE              16
  38#define SMB_GLOBAL_STATUS       (0x0 + amd756_ioport)
  39#define SMB_GLOBAL_ENABLE       (0x2 + amd756_ioport)
  40#define SMB_HOST_ADDRESS        (0x4 + amd756_ioport)
  41#define SMB_HOST_DATA           (0x6 + amd756_ioport)
  42#define SMB_HOST_COMMAND        (0x8 + amd756_ioport)
  43#define SMB_HOST_BLOCK_DATA     (0x9 + amd756_ioport)
  44#define SMB_HAS_DATA            (0xA + amd756_ioport)
  45#define SMB_HAS_DEVICE_ADDRESS  (0xC + amd756_ioport)
  46#define SMB_HAS_HOST_ADDRESS    (0xE + amd756_ioport)
  47#define SMB_SNOOP_ADDRESS       (0xF + amd756_ioport)
  48
  49/* PCI Address Constants */
  50
  51/* address of I/O space */
  52#define SMBBA           0x058           /* mh */
  53#define SMBBANFORCE     0x014
  54
  55/* general configuration */
  56#define SMBGCFG         0x041           /* mh */
  57
  58/* silicon revision code */
  59#define SMBREV          0x008
  60
  61/* Other settings */
  62#define MAX_TIMEOUT     500
  63
  64/* AMD756 constants */
  65#define AMD756_QUICK            0x00
  66#define AMD756_BYTE             0x01
  67#define AMD756_BYTE_DATA        0x02
  68#define AMD756_WORD_DATA        0x03
  69#define AMD756_PROCESS_CALL     0x04
  70#define AMD756_BLOCK_DATA       0x05
  71
  72static struct pci_driver amd756_driver;
  73static unsigned short amd756_ioport;
  74
  75/* 
  76  SMBUS event = I/O 28-29 bit 11
  77     see E0 for the status bits and enabled in E2
  78     
  79*/
  80#define GS_ABRT_STS     (1 << 0)
  81#define GS_COL_STS      (1 << 1)
  82#define GS_PRERR_STS    (1 << 2)
  83#define GS_HST_STS      (1 << 3)
  84#define GS_HCYC_STS     (1 << 4)
  85#define GS_TO_STS       (1 << 5)
  86#define GS_SMB_STS      (1 << 11)
  87
  88#define GS_CLEAR_STS    (GS_ABRT_STS | GS_COL_STS | GS_PRERR_STS | \
  89                         GS_HCYC_STS | GS_TO_STS )
  90
  91#define GE_CYC_TYPE_MASK        (7)
  92#define GE_HOST_STC             (1 << 3)
  93#define GE_ABORT                (1 << 5)
  94
  95
  96static int amd756_transaction(struct i2c_adapter *adap)
  97{
  98        int temp;
  99        int result = 0;
 100        int timeout = 0;
 101
 102        dev_dbg(&adap->dev, "Transaction (pre): GS=%04x, GE=%04x, ADD=%04x, "
 103                "DAT=%04x\n", inw_p(SMB_GLOBAL_STATUS),
 104                inw_p(SMB_GLOBAL_ENABLE), inw_p(SMB_HOST_ADDRESS),
 105                inb_p(SMB_HOST_DATA));
 106
 107        /* Make sure the SMBus host is ready to start transmitting */
 108        if ((temp = inw_p(SMB_GLOBAL_STATUS)) & (GS_HST_STS | GS_SMB_STS)) {
 109                dev_dbg(&adap->dev, "SMBus busy (%04x). Waiting...\n", temp);
 110                do {
 111                        msleep(1);
 112                        temp = inw_p(SMB_GLOBAL_STATUS);
 113                } while ((temp & (GS_HST_STS | GS_SMB_STS)) &&
 114                         (timeout++ < MAX_TIMEOUT));
 115                /* If the SMBus is still busy, we give up */
 116                if (timeout > MAX_TIMEOUT) {
 117                        dev_dbg(&adap->dev, "Busy wait timeout (%04x)\n", temp);
 118                        goto abort;
 119                }
 120                timeout = 0;
 121        }
 122
 123        /* start the transaction by setting the start bit */
 124        outw_p(inw(SMB_GLOBAL_ENABLE) | GE_HOST_STC, SMB_GLOBAL_ENABLE);
 125
 126        /* We will always wait for a fraction of a second! */
 127        do {
 128                msleep(1);
 129                temp = inw_p(SMB_GLOBAL_STATUS);
 130        } while ((temp & GS_HST_STS) && (timeout++ < MAX_TIMEOUT));
 131
 132        /* If the SMBus is still busy, we give up */
 133        if (timeout > MAX_TIMEOUT) {
 134                dev_dbg(&adap->dev, "Completion timeout!\n");
 135                goto abort;
 136        }
 137
 138        if (temp & GS_PRERR_STS) {
 139                result = -ENXIO;
 140                dev_dbg(&adap->dev, "SMBus Protocol error (no response)!\n");
 141        }
 142
 143        if (temp & GS_COL_STS) {
 144                result = -EIO;
 145                dev_warn(&adap->dev, "SMBus collision!\n");
 146        }
 147
 148        if (temp & GS_TO_STS) {
 149                result = -ETIMEDOUT;
 150                dev_dbg(&adap->dev, "SMBus protocol timeout!\n");
 151        }
 152
 153        if (temp & GS_HCYC_STS)
 154                dev_dbg(&adap->dev, "SMBus protocol success!\n");
 155
 156        outw_p(GS_CLEAR_STS, SMB_GLOBAL_STATUS);
 157
 158#ifdef DEBUG
 159        if (((temp = inw_p(SMB_GLOBAL_STATUS)) & GS_CLEAR_STS) != 0x00) {
 160                dev_dbg(&adap->dev,
 161                        "Failed reset at end of transaction (%04x)\n", temp);
 162        }
 163#endif
 164
 165        dev_dbg(&adap->dev,
 166                "Transaction (post): GS=%04x, GE=%04x, ADD=%04x, DAT=%04x\n",
 167                inw_p(SMB_GLOBAL_STATUS), inw_p(SMB_GLOBAL_ENABLE),
 168                inw_p(SMB_HOST_ADDRESS), inb_p(SMB_HOST_DATA));
 169
 170        return result;
 171
 172 abort:
 173        dev_warn(&adap->dev, "Sending abort\n");
 174        outw_p(inw(SMB_GLOBAL_ENABLE) | GE_ABORT, SMB_GLOBAL_ENABLE);
 175        msleep(100);
 176        outw_p(GS_CLEAR_STS, SMB_GLOBAL_STATUS);
 177        return -EIO;
 178}
 179
 180/* Return negative errno on error. */
 181static s32 amd756_access(struct i2c_adapter * adap, u16 addr,
 182                  unsigned short flags, char read_write,
 183                  u8 command, int size, union i2c_smbus_data * data)
 184{
 185        int i, len;
 186        int status;
 187
 188        switch (size) {
 189        case I2C_SMBUS_QUICK:
 190                outw_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 191                       SMB_HOST_ADDRESS);
 192                size = AMD756_QUICK;
 193                break;
 194        case I2C_SMBUS_BYTE:
 195                outw_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 196                       SMB_HOST_ADDRESS);
 197                if (read_write == I2C_SMBUS_WRITE)
 198                        outb_p(command, SMB_HOST_DATA);
 199                size = AMD756_BYTE;
 200                break;
 201        case I2C_SMBUS_BYTE_DATA:
 202                outw_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 203                       SMB_HOST_ADDRESS);
 204                outb_p(command, SMB_HOST_COMMAND);
 205                if (read_write == I2C_SMBUS_WRITE)
 206                        outw_p(data->byte, SMB_HOST_DATA);
 207                size = AMD756_BYTE_DATA;
 208                break;
 209        case I2C_SMBUS_WORD_DATA:
 210                outw_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 211                       SMB_HOST_ADDRESS);
 212                outb_p(command, SMB_HOST_COMMAND);
 213                if (read_write == I2C_SMBUS_WRITE)
 214                        outw_p(data->word, SMB_HOST_DATA);      /* TODO: endian???? */
 215                size = AMD756_WORD_DATA;
 216                break;
 217        case I2C_SMBUS_BLOCK_DATA:
 218                outw_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 219                       SMB_HOST_ADDRESS);
 220                outb_p(command, SMB_HOST_COMMAND);
 221                if (read_write == I2C_SMBUS_WRITE) {
 222                        len = data->block[0];
 223                        if (len < 0)
 224                                len = 0;
 225                        if (len > 32)
 226                                len = 32;
 227                        outw_p(len, SMB_HOST_DATA);
 228                        /* i = inw_p(SMBHSTCNT); Reset SMBBLKDAT */
 229                        for (i = 1; i <= len; i++)
 230                                outb_p(data->block[i],
 231                                       SMB_HOST_BLOCK_DATA);
 232                }
 233                size = AMD756_BLOCK_DATA;
 234                break;
 235        default:
 236                dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
 237                return -EOPNOTSUPP;
 238        }
 239
 240        /* How about enabling interrupts... */
 241        outw_p(size & GE_CYC_TYPE_MASK, SMB_GLOBAL_ENABLE);
 242
 243        status = amd756_transaction(adap);
 244        if (status)
 245                return status;
 246
 247        if ((read_write == I2C_SMBUS_WRITE) || (size == AMD756_QUICK))
 248                return 0;
 249
 250
 251        switch (size) {
 252        case AMD756_BYTE:
 253                data->byte = inw_p(SMB_HOST_DATA);
 254                break;
 255        case AMD756_BYTE_DATA:
 256                data->byte = inw_p(SMB_HOST_DATA);
 257                break;
 258        case AMD756_WORD_DATA:
 259                data->word = inw_p(SMB_HOST_DATA);      /* TODO: endian???? */
 260                break;
 261        case AMD756_BLOCK_DATA:
 262                data->block[0] = inw_p(SMB_HOST_DATA) & 0x3f;
 263                if(data->block[0] > 32)
 264                        data->block[0] = 32;
 265                /* i = inw_p(SMBHSTCNT); Reset SMBBLKDAT */
 266                for (i = 1; i <= data->block[0]; i++)
 267                        data->block[i] = inb_p(SMB_HOST_BLOCK_DATA);
 268                break;
 269        }
 270
 271        return 0;
 272}
 273
 274static u32 amd756_func(struct i2c_adapter *adapter)
 275{
 276        return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 277            I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 278            I2C_FUNC_SMBUS_BLOCK_DATA;
 279}
 280
 281static const struct i2c_algorithm smbus_algorithm = {
 282        .smbus_xfer     = amd756_access,
 283        .functionality  = amd756_func,
 284};
 285
 286struct i2c_adapter amd756_smbus = {
 287        .owner          = THIS_MODULE,
 288        .class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
 289        .algo           = &smbus_algorithm,
 290};
 291
 292enum chiptype { AMD756, AMD766, AMD768, NFORCE, AMD8111 };
 293static const char* chipname[] = {
 294        "AMD756", "AMD766", "AMD768",
 295        "nVidia nForce", "AMD8111",
 296};
 297
 298static const struct pci_device_id amd756_ids[] = {
 299        { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_VIPER_740B),
 300          .driver_data = AMD756 },
 301        { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_VIPER_7413),
 302          .driver_data = AMD766 },
 303        { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_OPUS_7443),
 304          .driver_data = AMD768 },
 305        { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_8111_SMBUS),
 306          .driver_data = AMD8111 },
 307        { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_SMBUS),
 308          .driver_data = NFORCE },
 309        { 0, }
 310};
 311
 312MODULE_DEVICE_TABLE (pci, amd756_ids);
 313
 314static int amd756_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 315{
 316        int nforce = (id->driver_data == NFORCE);
 317        int error;
 318        u8 temp;
 319        
 320        if (amd756_ioport) {
 321                dev_err(&pdev->dev, "Only one device supported "
 322                       "(you have a strange motherboard, btw)\n");
 323                return -ENODEV;
 324        }
 325
 326        if (nforce) {
 327                if (PCI_FUNC(pdev->devfn) != 1)
 328                        return -ENODEV;
 329
 330                pci_read_config_word(pdev, SMBBANFORCE, &amd756_ioport);
 331                amd756_ioport &= 0xfffc;
 332        } else { /* amd */
 333                if (PCI_FUNC(pdev->devfn) != 3)
 334                        return -ENODEV;
 335
 336                pci_read_config_byte(pdev, SMBGCFG, &temp);
 337                if ((temp & 128) == 0) {
 338                        dev_err(&pdev->dev,
 339                                "Error: SMBus controller I/O not enabled!\n");
 340                        return -ENODEV;
 341                }
 342
 343                /* Determine the address of the SMBus areas */
 344                /* Technically it is a dword but... */
 345                pci_read_config_word(pdev, SMBBA, &amd756_ioport);
 346                amd756_ioport &= 0xff00;
 347                amd756_ioport += SMB_ADDR_OFFSET;
 348        }
 349
 350        error = acpi_check_region(amd756_ioport, SMB_IOSIZE,
 351                                  amd756_driver.name);
 352        if (error)
 353                return -ENODEV;
 354
 355        if (!request_region(amd756_ioport, SMB_IOSIZE, amd756_driver.name)) {
 356                dev_err(&pdev->dev, "SMB region 0x%x already in use!\n",
 357                        amd756_ioport);
 358                return -ENODEV;
 359        }
 360
 361        pci_read_config_byte(pdev, SMBREV, &temp);
 362        dev_dbg(&pdev->dev, "SMBREV = 0x%X\n", temp);
 363        dev_dbg(&pdev->dev, "AMD756_smba = 0x%X\n", amd756_ioport);
 364
 365        /* set up the sysfs linkage to our parent device */
 366        amd756_smbus.dev.parent = &pdev->dev;
 367
 368        snprintf(amd756_smbus.name, sizeof(amd756_smbus.name),
 369                 "SMBus %s adapter at %04x", chipname[id->driver_data],
 370                 amd756_ioport);
 371
 372        error = i2c_add_adapter(&amd756_smbus);
 373        if (error)
 374                goto out_err;
 375
 376        return 0;
 377
 378 out_err:
 379        release_region(amd756_ioport, SMB_IOSIZE);
 380        return error;
 381}
 382
 383static void amd756_remove(struct pci_dev *dev)
 384{
 385        i2c_del_adapter(&amd756_smbus);
 386        release_region(amd756_ioport, SMB_IOSIZE);
 387}
 388
 389static struct pci_driver amd756_driver = {
 390        .name           = "amd756_smbus",
 391        .id_table       = amd756_ids,
 392        .probe          = amd756_probe,
 393        .remove         = amd756_remove,
 394};
 395
 396module_pci_driver(amd756_driver);
 397
 398MODULE_AUTHOR("Merlin Hughes <merlin@merlin.org>");
 399MODULE_DESCRIPTION("AMD756/766/768/8111 and nVidia nForce SMBus driver");
 400MODULE_LICENSE("GPL");
 401
 402EXPORT_SYMBOL(amd756_smbus);
 403