linux/drivers/i2c/busses/i2c-amd8111.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * SMBus 2.0 driver for AMD-8111 IO-Hub.
   4 *
   5 * Copyright (c) 2002 Vojtech Pavlik
   6 */
   7
   8#include <linux/module.h>
   9#include <linux/pci.h>
  10#include <linux/kernel.h>
  11#include <linux/stddef.h>
  12#include <linux/ioport.h>
  13#include <linux/i2c.h>
  14#include <linux/delay.h>
  15#include <linux/acpi.h>
  16#include <linux/slab.h>
  17#include <linux/io.h>
  18
  19MODULE_LICENSE("GPL");
  20MODULE_AUTHOR ("Vojtech Pavlik <vojtech@suse.cz>");
  21MODULE_DESCRIPTION("AMD8111 SMBus 2.0 driver");
  22
  23struct amd_smbus {
  24        struct pci_dev *dev;
  25        struct i2c_adapter adapter;
  26        int base;
  27        int size;
  28};
  29
  30static struct pci_driver amd8111_driver;
  31
  32/*
  33 * AMD PCI control registers definitions.
  34 */
  35
  36#define AMD_PCI_MISC    0x48
  37
  38#define AMD_PCI_MISC_SCI        0x04    /* deliver SCI */
  39#define AMD_PCI_MISC_INT        0x02    /* deliver PCI IRQ */
  40#define AMD_PCI_MISC_SPEEDUP    0x01    /* 16x clock speedup */
  41
  42/*
  43 * ACPI 2.0 chapter 13 PCI interface definitions.
  44 */
  45
  46#define AMD_EC_DATA     0x00    /* data register */
  47#define AMD_EC_SC       0x04    /* status of controller */
  48#define AMD_EC_CMD      0x04    /* command register */
  49#define AMD_EC_ICR      0x08    /* interrupt control register */
  50
  51#define AMD_EC_SC_SMI   0x04    /* smi event pending */
  52#define AMD_EC_SC_SCI   0x02    /* sci event pending */
  53#define AMD_EC_SC_BURST 0x01    /* burst mode enabled */
  54#define AMD_EC_SC_CMD   0x08    /* byte in data reg is command */
  55#define AMD_EC_SC_IBF   0x02    /* data ready for embedded controller */
  56#define AMD_EC_SC_OBF   0x01    /* data ready for host */
  57
  58#define AMD_EC_CMD_RD   0x80    /* read EC */
  59#define AMD_EC_CMD_WR   0x81    /* write EC */
  60#define AMD_EC_CMD_BE   0x82    /* enable burst mode */
  61#define AMD_EC_CMD_BD   0x83    /* disable burst mode */
  62#define AMD_EC_CMD_QR   0x84    /* query EC */
  63
  64/*
  65 * ACPI 2.0 chapter 13 access of registers of the EC
  66 */
  67
  68static int amd_ec_wait_write(struct amd_smbus *smbus)
  69{
  70        int timeout = 500;
  71
  72        while ((inb(smbus->base + AMD_EC_SC) & AMD_EC_SC_IBF) && --timeout)
  73                udelay(1);
  74
  75        if (!timeout) {
  76                dev_warn(&smbus->dev->dev,
  77                         "Timeout while waiting for IBF to clear\n");
  78                return -ETIMEDOUT;
  79        }
  80
  81        return 0;
  82}
  83
  84static int amd_ec_wait_read(struct amd_smbus *smbus)
  85{
  86        int timeout = 500;
  87
  88        while ((~inb(smbus->base + AMD_EC_SC) & AMD_EC_SC_OBF) && --timeout)
  89                udelay(1);
  90
  91        if (!timeout) {
  92                dev_warn(&smbus->dev->dev,
  93                         "Timeout while waiting for OBF to set\n");
  94                return -ETIMEDOUT;
  95        }
  96
  97        return 0;
  98}
  99
 100static int amd_ec_read(struct amd_smbus *smbus, unsigned char address,
 101                unsigned char *data)
 102{
 103        int status;
 104
 105        status = amd_ec_wait_write(smbus);
 106        if (status)
 107                return status;
 108        outb(AMD_EC_CMD_RD, smbus->base + AMD_EC_CMD);
 109
 110        status = amd_ec_wait_write(smbus);
 111        if (status)
 112                return status;
 113        outb(address, smbus->base + AMD_EC_DATA);
 114
 115        status = amd_ec_wait_read(smbus);
 116        if (status)
 117                return status;
 118        *data = inb(smbus->base + AMD_EC_DATA);
 119
 120        return 0;
 121}
 122
 123static int amd_ec_write(struct amd_smbus *smbus, unsigned char address,
 124                unsigned char data)
 125{
 126        int status;
 127
 128        status = amd_ec_wait_write(smbus);
 129        if (status)
 130                return status;
 131        outb(AMD_EC_CMD_WR, smbus->base + AMD_EC_CMD);
 132
 133        status = amd_ec_wait_write(smbus);
 134        if (status)
 135                return status;
 136        outb(address, smbus->base + AMD_EC_DATA);
 137
 138        status = amd_ec_wait_write(smbus);
 139        if (status)
 140                return status;
 141        outb(data, smbus->base + AMD_EC_DATA);
 142
 143        return 0;
 144}
 145
 146/*
 147 * ACPI 2.0 chapter 13 SMBus 2.0 EC register model
 148 */
 149
 150#define AMD_SMB_PRTCL   0x00    /* protocol, PEC */
 151#define AMD_SMB_STS     0x01    /* status */
 152#define AMD_SMB_ADDR    0x02    /* address */
 153#define AMD_SMB_CMD     0x03    /* command */
 154#define AMD_SMB_DATA    0x04    /* 32 data registers */
 155#define AMD_SMB_BCNT    0x24    /* number of data bytes */
 156#define AMD_SMB_ALRM_A  0x25    /* alarm address */
 157#define AMD_SMB_ALRM_D  0x26    /* 2 bytes alarm data */
 158
 159#define AMD_SMB_STS_DONE        0x80
 160#define AMD_SMB_STS_ALRM        0x40
 161#define AMD_SMB_STS_RES         0x20
 162#define AMD_SMB_STS_STATUS      0x1f
 163
 164#define AMD_SMB_STATUS_OK       0x00
 165#define AMD_SMB_STATUS_FAIL     0x07
 166#define AMD_SMB_STATUS_DNAK     0x10
 167#define AMD_SMB_STATUS_DERR     0x11
 168#define AMD_SMB_STATUS_CMD_DENY 0x12
 169#define AMD_SMB_STATUS_UNKNOWN  0x13
 170#define AMD_SMB_STATUS_ACC_DENY 0x17
 171#define AMD_SMB_STATUS_TIMEOUT  0x18
 172#define AMD_SMB_STATUS_NOTSUP   0x19
 173#define AMD_SMB_STATUS_BUSY     0x1A
 174#define AMD_SMB_STATUS_PEC      0x1F
 175
 176#define AMD_SMB_PRTCL_WRITE             0x00
 177#define AMD_SMB_PRTCL_READ              0x01
 178#define AMD_SMB_PRTCL_QUICK             0x02
 179#define AMD_SMB_PRTCL_BYTE              0x04
 180#define AMD_SMB_PRTCL_BYTE_DATA         0x06
 181#define AMD_SMB_PRTCL_WORD_DATA         0x08
 182#define AMD_SMB_PRTCL_BLOCK_DATA        0x0a
 183#define AMD_SMB_PRTCL_PROC_CALL         0x0c
 184#define AMD_SMB_PRTCL_BLOCK_PROC_CALL   0x0d
 185#define AMD_SMB_PRTCL_I2C_BLOCK_DATA    0x4a
 186#define AMD_SMB_PRTCL_PEC               0x80
 187
 188
 189static s32 amd8111_access(struct i2c_adapter *adap, u16 addr,
 190                unsigned short flags, char read_write, u8 command, int size,
 191                union i2c_smbus_data *data)
 192{
 193        struct amd_smbus *smbus = adap->algo_data;
 194        unsigned char protocol, len, pec, temp[2];
 195        int i, status;
 196
 197        protocol = (read_write == I2C_SMBUS_READ) ? AMD_SMB_PRTCL_READ
 198                                                  : AMD_SMB_PRTCL_WRITE;
 199        pec = (flags & I2C_CLIENT_PEC) ? AMD_SMB_PRTCL_PEC : 0;
 200
 201        switch (size) {
 202        case I2C_SMBUS_QUICK:
 203                protocol |= AMD_SMB_PRTCL_QUICK;
 204                read_write = I2C_SMBUS_WRITE;
 205                break;
 206
 207        case I2C_SMBUS_BYTE:
 208                if (read_write == I2C_SMBUS_WRITE) {
 209                        status = amd_ec_write(smbus, AMD_SMB_CMD,
 210                                                command);
 211                        if (status)
 212                                return status;
 213                }
 214                protocol |= AMD_SMB_PRTCL_BYTE;
 215                break;
 216
 217        case I2C_SMBUS_BYTE_DATA:
 218                status = amd_ec_write(smbus, AMD_SMB_CMD, command);
 219                if (status)
 220                        return status;
 221                if (read_write == I2C_SMBUS_WRITE) {
 222                        status = amd_ec_write(smbus, AMD_SMB_DATA,
 223                                                data->byte);
 224                        if (status)
 225                                return status;
 226                }
 227                protocol |= AMD_SMB_PRTCL_BYTE_DATA;
 228                break;
 229
 230        case I2C_SMBUS_WORD_DATA:
 231                status = amd_ec_write(smbus, AMD_SMB_CMD, command);
 232                if (status)
 233                        return status;
 234                if (read_write == I2C_SMBUS_WRITE) {
 235                        status = amd_ec_write(smbus, AMD_SMB_DATA,
 236                                                data->word & 0xff);
 237                        if (status)
 238                                return status;
 239                        status = amd_ec_write(smbus, AMD_SMB_DATA + 1,
 240                                                data->word >> 8);
 241                        if (status)
 242                                return status;
 243                }
 244                protocol |= AMD_SMB_PRTCL_WORD_DATA | pec;
 245                break;
 246
 247        case I2C_SMBUS_BLOCK_DATA:
 248                status = amd_ec_write(smbus, AMD_SMB_CMD, command);
 249                if (status)
 250                        return status;
 251                if (read_write == I2C_SMBUS_WRITE) {
 252                        len = min_t(u8, data->block[0],
 253                                        I2C_SMBUS_BLOCK_MAX);
 254                        status = amd_ec_write(smbus, AMD_SMB_BCNT, len);
 255                        if (status)
 256                                return status;
 257                        for (i = 0; i < len; i++) {
 258                                status =
 259                                        amd_ec_write(smbus, AMD_SMB_DATA + i,
 260                                                data->block[i + 1]);
 261                                if (status)
 262                                        return status;
 263                        }
 264                }
 265                protocol |= AMD_SMB_PRTCL_BLOCK_DATA | pec;
 266                break;
 267
 268        case I2C_SMBUS_I2C_BLOCK_DATA:
 269                len = min_t(u8, data->block[0],
 270                                I2C_SMBUS_BLOCK_MAX);
 271                status = amd_ec_write(smbus, AMD_SMB_CMD, command);
 272                if (status)
 273                        return status;
 274                status = amd_ec_write(smbus, AMD_SMB_BCNT, len);
 275                if (status)
 276                        return status;
 277                if (read_write == I2C_SMBUS_WRITE)
 278                        for (i = 0; i < len; i++) {
 279                                status =
 280                                        amd_ec_write(smbus, AMD_SMB_DATA + i,
 281                                                data->block[i + 1]);
 282                                if (status)
 283                                        return status;
 284                        }
 285                protocol |= AMD_SMB_PRTCL_I2C_BLOCK_DATA;
 286                break;
 287
 288        case I2C_SMBUS_PROC_CALL:
 289                status = amd_ec_write(smbus, AMD_SMB_CMD, command);
 290                if (status)
 291                        return status;
 292                status = amd_ec_write(smbus, AMD_SMB_DATA,
 293                                        data->word & 0xff);
 294                if (status)
 295                        return status;
 296                status = amd_ec_write(smbus, AMD_SMB_DATA + 1,
 297                                        data->word >> 8);
 298                if (status)
 299                        return status;
 300                protocol = AMD_SMB_PRTCL_PROC_CALL | pec;
 301                read_write = I2C_SMBUS_READ;
 302                break;
 303
 304        case I2C_SMBUS_BLOCK_PROC_CALL:
 305                len = min_t(u8, data->block[0],
 306                                I2C_SMBUS_BLOCK_MAX - 1);
 307                status = amd_ec_write(smbus, AMD_SMB_CMD, command);
 308                if (status)
 309                        return status;
 310                status = amd_ec_write(smbus, AMD_SMB_BCNT, len);
 311                if (status)
 312                        return status;
 313                for (i = 0; i < len; i++) {
 314                        status = amd_ec_write(smbus, AMD_SMB_DATA + i,
 315                                                data->block[i + 1]);
 316                        if (status)
 317                                return status;
 318                }
 319                protocol = AMD_SMB_PRTCL_BLOCK_PROC_CALL | pec;
 320                read_write = I2C_SMBUS_READ;
 321                break;
 322
 323        default:
 324                dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
 325                return -EOPNOTSUPP;
 326        }
 327
 328        status = amd_ec_write(smbus, AMD_SMB_ADDR, addr << 1);
 329        if (status)
 330                return status;
 331        status = amd_ec_write(smbus, AMD_SMB_PRTCL, protocol);
 332        if (status)
 333                return status;
 334
 335        status = amd_ec_read(smbus, AMD_SMB_STS, temp + 0);
 336        if (status)
 337                return status;
 338
 339        if (~temp[0] & AMD_SMB_STS_DONE) {
 340                udelay(500);
 341                status = amd_ec_read(smbus, AMD_SMB_STS, temp + 0);
 342                if (status)
 343                        return status;
 344        }
 345
 346        if (~temp[0] & AMD_SMB_STS_DONE) {
 347                msleep(1);
 348                status = amd_ec_read(smbus, AMD_SMB_STS, temp + 0);
 349                if (status)
 350                        return status;
 351        }
 352
 353        if ((~temp[0] & AMD_SMB_STS_DONE) || (temp[0] & AMD_SMB_STS_STATUS))
 354                return -EIO;
 355
 356        if (read_write == I2C_SMBUS_WRITE)
 357                return 0;
 358
 359        switch (size) {
 360        case I2C_SMBUS_BYTE:
 361        case I2C_SMBUS_BYTE_DATA:
 362                status = amd_ec_read(smbus, AMD_SMB_DATA, &data->byte);
 363                if (status)
 364                        return status;
 365                break;
 366
 367        case I2C_SMBUS_WORD_DATA:
 368        case I2C_SMBUS_PROC_CALL:
 369                status = amd_ec_read(smbus, AMD_SMB_DATA, temp + 0);
 370                if (status)
 371                        return status;
 372                status = amd_ec_read(smbus, AMD_SMB_DATA + 1, temp + 1);
 373                if (status)
 374                        return status;
 375                data->word = (temp[1] << 8) | temp[0];
 376                break;
 377
 378        case I2C_SMBUS_BLOCK_DATA:
 379        case I2C_SMBUS_BLOCK_PROC_CALL:
 380                status = amd_ec_read(smbus, AMD_SMB_BCNT, &len);
 381                if (status)
 382                        return status;
 383                len = min_t(u8, len, I2C_SMBUS_BLOCK_MAX);
 384                fallthrough;
 385        case I2C_SMBUS_I2C_BLOCK_DATA:
 386                for (i = 0; i < len; i++) {
 387                        status = amd_ec_read(smbus, AMD_SMB_DATA + i,
 388                                                data->block + i + 1);
 389                        if (status)
 390                                return status;
 391                }
 392                data->block[0] = len;
 393                break;
 394        }
 395
 396        return 0;
 397}
 398
 399
 400static u32 amd8111_func(struct i2c_adapter *adapter)
 401{
 402        return  I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 403                I2C_FUNC_SMBUS_BYTE_DATA |
 404                I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BLOCK_DATA |
 405                I2C_FUNC_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
 406                I2C_FUNC_SMBUS_I2C_BLOCK | I2C_FUNC_SMBUS_PEC;
 407}
 408
 409static const struct i2c_algorithm smbus_algorithm = {
 410        .smbus_xfer = amd8111_access,
 411        .functionality = amd8111_func,
 412};
 413
 414
 415static const struct pci_device_id amd8111_ids[] = {
 416        { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_8111_SMBUS2) },
 417        { 0, }
 418};
 419
 420MODULE_DEVICE_TABLE (pci, amd8111_ids);
 421
 422static int amd8111_probe(struct pci_dev *dev, const struct pci_device_id *id)
 423{
 424        struct amd_smbus *smbus;
 425        int error;
 426
 427        if (!(pci_resource_flags(dev, 0) & IORESOURCE_IO))
 428                return -ENODEV;
 429
 430        smbus = kzalloc(sizeof(struct amd_smbus), GFP_KERNEL);
 431        if (!smbus)
 432                return -ENOMEM;
 433
 434        smbus->dev = dev;
 435        smbus->base = pci_resource_start(dev, 0);
 436        smbus->size = pci_resource_len(dev, 0);
 437
 438        error = acpi_check_resource_conflict(&dev->resource[0]);
 439        if (error) {
 440                error = -ENODEV;
 441                goto out_kfree;
 442        }
 443
 444        if (!request_region(smbus->base, smbus->size, amd8111_driver.name)) {
 445                error = -EBUSY;
 446                goto out_kfree;
 447        }
 448
 449        smbus->adapter.owner = THIS_MODULE;
 450        snprintf(smbus->adapter.name, sizeof(smbus->adapter.name),
 451                "SMBus2 AMD8111 adapter at %04x", smbus->base);
 452        smbus->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
 453        smbus->adapter.algo = &smbus_algorithm;
 454        smbus->adapter.algo_data = smbus;
 455
 456        /* set up the sysfs linkage to our parent device */
 457        smbus->adapter.dev.parent = &dev->dev;
 458
 459        pci_write_config_dword(smbus->dev, AMD_PCI_MISC, 0);
 460        error = i2c_add_adapter(&smbus->adapter);
 461        if (error)
 462                goto out_release_region;
 463
 464        pci_set_drvdata(dev, smbus);
 465        return 0;
 466
 467 out_release_region:
 468        release_region(smbus->base, smbus->size);
 469 out_kfree:
 470        kfree(smbus);
 471        return error;
 472}
 473
 474static void amd8111_remove(struct pci_dev *dev)
 475{
 476        struct amd_smbus *smbus = pci_get_drvdata(dev);
 477
 478        i2c_del_adapter(&smbus->adapter);
 479        release_region(smbus->base, smbus->size);
 480        kfree(smbus);
 481}
 482
 483static struct pci_driver amd8111_driver = {
 484        .name           = "amd8111_smbus2",
 485        .id_table       = amd8111_ids,
 486        .probe          = amd8111_probe,
 487        .remove         = amd8111_remove,
 488};
 489
 490module_pci_driver(amd8111_driver);
 491