i2c-ali1563.c

Go to the documentation of this file.

#include <linux/module.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/acpi.h>

#define ALI1563_MAX_TIMEOUT 500
#define ALI1563_SMBBA       0x80
#define ALI1563_SMB_IOEN    1
#define ALI1563_SMB_HOSTEN  2
#define ALI1563_SMB_IOSIZE  16

#define SMB_HST_STS (ali1563_smba + 0)
#define SMB_HST_CNTL1   (ali1563_smba + 1)
#define SMB_HST_CNTL2   (ali1563_smba + 2)
#define SMB_HST_CMD (ali1563_smba + 3)
#define SMB_HST_ADD (ali1563_smba + 4)
#define SMB_HST_DAT0    (ali1563_smba + 5)
#define SMB_HST_DAT1    (ali1563_smba + 6)
#define SMB_BLK_DAT (ali1563_smba + 7)

#define HST_STS_BUSY    0x01
#define HST_STS_INTR    0x02
#define HST_STS_DEVERR  0x04
#define HST_STS_BUSERR  0x08
#define HST_STS_FAIL    0x10
#define HST_STS_DONE    0x80
#define HST_STS_BAD 0x1c


#define HST_CNTL1_TIMEOUT   0x80
#define HST_CNTL1_LAST      0x40

#define HST_CNTL2_KILL      0x04
#define HST_CNTL2_START     0x40
#define HST_CNTL2_QUICK     0x00
#define HST_CNTL2_BYTE      0x01
#define HST_CNTL2_BYTE_DATA 0x02
#define HST_CNTL2_WORD_DATA 0x03
#define HST_CNTL2_BLOCK     0x05


#define HST_CNTL2_SIZEMASK  0x38

static struct pci_driver ali1563_pci_driver;
static unsigned short ali1563_smba;

static int ali1563_transaction(struct i2c_adapter * a, int size)
{
    u32 data;
    int timeout;
    int status = -EIO;

    dev_dbg(&a->dev, "Transaction (pre): STS=%02x, CNTL1=%02x, "
        "CNTL2=%02x, CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
        inb_p(SMB_HST_STS), inb_p(SMB_HST_CNTL1), inb_p(SMB_HST_CNTL2),
        inb_p(SMB_HST_CMD), inb_p(SMB_HST_ADD), inb_p(SMB_HST_DAT0),
        inb_p(SMB_HST_DAT1));

    data = inb_p(SMB_HST_STS);
    if (data & HST_STS_BAD) {
        dev_err(&a->dev, "ali1563: Trying to reset busy device\n");
        outb_p(data | HST_STS_BAD,SMB_HST_STS);
        data = inb_p(SMB_HST_STS);
        if (data & HST_STS_BAD)
            return -EBUSY;
    }
    outb_p(inb_p(SMB_HST_CNTL2) | HST_CNTL2_START, SMB_HST_CNTL2);

    timeout = ALI1563_MAX_TIMEOUT;
    do {
        msleep(1);
    } while (((data = inb_p(SMB_HST_STS)) & HST_STS_BUSY) && --timeout);

    dev_dbg(&a->dev, "Transaction (post): STS=%02x, CNTL1=%02x, "
        "CNTL2=%02x, CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
        inb_p(SMB_HST_STS), inb_p(SMB_HST_CNTL1), inb_p(SMB_HST_CNTL2),
        inb_p(SMB_HST_CMD), inb_p(SMB_HST_ADD), inb_p(SMB_HST_DAT0),
        inb_p(SMB_HST_DAT1));

    if (timeout && !(data & HST_STS_BAD))
        return 0;

    if (!timeout) {
        dev_err(&a->dev, "Timeout - Trying to KILL transaction!\n");
        /* Issue 'kill' to host controller */
        outb_p(HST_CNTL2_KILL,SMB_HST_CNTL2);
        data = inb_p(SMB_HST_STS);
        status = -ETIMEDOUT;
    }

    /* device error - no response, ignore the autodetection case */
    if (data & HST_STS_DEVERR) {
        if (size != HST_CNTL2_QUICK)
            dev_err(&a->dev, "Device error!\n");
        status = -ENXIO;
    }
    /* bus collision */
    if (data & HST_STS_BUSERR) {
        dev_err(&a->dev, "Bus collision!\n");
        /* Issue timeout, hoping it helps */
        outb_p(HST_CNTL1_TIMEOUT,SMB_HST_CNTL1);
    }

    if (data & HST_STS_FAIL) {
        dev_err(&a->dev, "Cleaning fail after KILL!\n");
        outb_p(0x0,SMB_HST_CNTL2);
    }

    return status;
}

static int ali1563_block_start(struct i2c_adapter * a)
{
    u32 data;
    int timeout;
    int status = -EIO;

    dev_dbg(&a->dev, "Block (pre): STS=%02x, CNTL1=%02x, "
        "CNTL2=%02x, CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
        inb_p(SMB_HST_STS), inb_p(SMB_HST_CNTL1), inb_p(SMB_HST_CNTL2),
        inb_p(SMB_HST_CMD), inb_p(SMB_HST_ADD), inb_p(SMB_HST_DAT0),
        inb_p(SMB_HST_DAT1));

    data = inb_p(SMB_HST_STS);
    if (data & HST_STS_BAD) {
        dev_warn(&a->dev,"ali1563: Trying to reset busy device\n");
        outb_p(data | HST_STS_BAD,SMB_HST_STS);
        data = inb_p(SMB_HST_STS);
        if (data & HST_STS_BAD)
            return -EBUSY;
    }

    /* Clear byte-ready bit */
    outb_p(data | HST_STS_DONE, SMB_HST_STS);

    /* Start transaction and wait for byte-ready bit to be set */
    outb_p(inb_p(SMB_HST_CNTL2) | HST_CNTL2_START, SMB_HST_CNTL2);

    timeout = ALI1563_MAX_TIMEOUT;
    do {
        msleep(1);
    } while (!((data = inb_p(SMB_HST_STS)) & HST_STS_DONE) && --timeout);

    dev_dbg(&a->dev, "Block (post): STS=%02x, CNTL1=%02x, "
        "CNTL2=%02x, CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
        inb_p(SMB_HST_STS), inb_p(SMB_HST_CNTL1), inb_p(SMB_HST_CNTL2),
        inb_p(SMB_HST_CMD), inb_p(SMB_HST_ADD), inb_p(SMB_HST_DAT0),
        inb_p(SMB_HST_DAT1));

    if (timeout && !(data & HST_STS_BAD))
        return 0;

    if (timeout == 0)
        status = -ETIMEDOUT;

    if (data & HST_STS_DEVERR)
        status = -ENXIO;

    dev_err(&a->dev, "SMBus Error: %s%s%s%s%s\n",
        timeout ? "" : "Timeout ",
        data & HST_STS_FAIL ? "Transaction Failed " : "",
        data & HST_STS_BUSERR ? "No response or Bus Collision " : "",
        data & HST_STS_DEVERR ? "Device Error " : "",
        !(data & HST_STS_DONE) ? "Transaction Never Finished " : "");
    return status;
}

static int ali1563_block(struct i2c_adapter * a, union i2c_smbus_data * data, u8 rw)
{
    int i, len;
    int error = 0;

    /* Do we need this? */
    outb_p(HST_CNTL1_LAST,SMB_HST_CNTL1);

    if (rw == I2C_SMBUS_WRITE) {
        len = data->block[0];
        if (len < 1)
            len = 1;
        else if (len > 32)
            len = 32;
        outb_p(len,SMB_HST_DAT0);
        outb_p(data->block[1],SMB_BLK_DAT);
    } else
        len = 32;

    outb_p(inb_p(SMB_HST_CNTL2) | HST_CNTL2_BLOCK, SMB_HST_CNTL2);

    for (i = 0; i < len; i++) {
        if (rw == I2C_SMBUS_WRITE) {
            outb_p(data->block[i + 1], SMB_BLK_DAT);
            if ((error = ali1563_block_start(a)))
                break;
        } else {
            if ((error = ali1563_block_start(a)))
                break;
            if (i == 0) {
                len = inb_p(SMB_HST_DAT0);
                if (len < 1)
                    len = 1;
                else if (len > 32)
                    len = 32;
            }
            data->block[i+1] = inb_p(SMB_BLK_DAT);
        }
    }
    /* Do we need this? */
    outb_p(HST_CNTL1_LAST,SMB_HST_CNTL1);
    return error;
}

static s32 ali1563_access(struct i2c_adapter * a, u16 addr,
              unsigned short flags, char rw, u8 cmd,
              int size, union i2c_smbus_data * data)
{
    int error = 0;
    int timeout;
    u32 reg;

    for (timeout = ALI1563_MAX_TIMEOUT; timeout; timeout--) {
        if (!(reg = inb_p(SMB_HST_STS) & HST_STS_BUSY))
            break;
    }
    if (!timeout)
        dev_warn(&a->dev,"SMBus not idle. HST_STS = %02x\n",reg);
    outb_p(0xff,SMB_HST_STS);

    /* Map the size to what the chip understands */
    switch (size) {
    case I2C_SMBUS_QUICK:
        size = HST_CNTL2_QUICK;
        break;
    case I2C_SMBUS_BYTE:
        size = HST_CNTL2_BYTE;
        break;
    case I2C_SMBUS_BYTE_DATA:
        size = HST_CNTL2_BYTE_DATA;
        break;
    case I2C_SMBUS_WORD_DATA:
        size = HST_CNTL2_WORD_DATA;
        break;
    case I2C_SMBUS_BLOCK_DATA:
        size = HST_CNTL2_BLOCK;
        break;
    default:
        dev_warn(&a->dev, "Unsupported transaction %d\n", size);
        error = -EOPNOTSUPP;
        goto Done;
    }

    outb_p(((addr & 0x7f) << 1) | (rw & 0x01), SMB_HST_ADD);
    outb_p((inb_p(SMB_HST_CNTL2) & ~HST_CNTL2_SIZEMASK) | (size << 3), SMB_HST_CNTL2);

    /* Write the command register */

    switch(size) {
    case HST_CNTL2_BYTE:
        if (rw== I2C_SMBUS_WRITE)
            /* Beware it uses DAT0 register and not CMD! */
            outb_p(cmd, SMB_HST_DAT0);
        break;
    case HST_CNTL2_BYTE_DATA:
        outb_p(cmd, SMB_HST_CMD);
        if (rw == I2C_SMBUS_WRITE)
            outb_p(data->byte, SMB_HST_DAT0);
        break;
    case HST_CNTL2_WORD_DATA:
        outb_p(cmd, SMB_HST_CMD);
        if (rw == I2C_SMBUS_WRITE) {
            outb_p(data->word & 0xff, SMB_HST_DAT0);
            outb_p((data->word & 0xff00) >> 8, SMB_HST_DAT1);
        }
        break;
    case HST_CNTL2_BLOCK:
        outb_p(cmd, SMB_HST_CMD);
        error = ali1563_block(a,data,rw);
        goto Done;
    }

    if ((error = ali1563_transaction(a, size)))
        goto Done;

    if ((rw == I2C_SMBUS_WRITE) || (size == HST_CNTL2_QUICK))
        goto Done;

    switch (size) {
    case HST_CNTL2_BYTE:    /* Result put in SMBHSTDAT0 */
        data->byte = inb_p(SMB_HST_DAT0);
        break;
    case HST_CNTL2_BYTE_DATA:
        data->byte = inb_p(SMB_HST_DAT0);
        break;
    case HST_CNTL2_WORD_DATA:
        data->word = inb_p(SMB_HST_DAT0) + (inb_p(SMB_HST_DAT1) << 8);
        break;
    }
Done:
    return error;
}

static u32 ali1563_func(struct i2c_adapter * a)
{
    return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
        I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
        I2C_FUNC_SMBUS_BLOCK_DATA;
}


static int __devinit ali1563_setup(struct pci_dev * dev)
{
    u16 ctrl;

    pci_read_config_word(dev,ALI1563_SMBBA,&ctrl);

    /* SMB I/O Base in high 12 bits and must be aligned with the
     * size of the I/O space. */
    ali1563_smba = ctrl & ~(ALI1563_SMB_IOSIZE - 1);
    if (!ali1563_smba) {
        dev_warn(&dev->dev,"ali1563_smba Uninitialized\n");
        goto Err;
    }

    /* Check if device is enabled */
    if (!(ctrl & ALI1563_SMB_HOSTEN)) {
        dev_warn(&dev->dev, "Host Controller not enabled\n");
        goto Err;
    }
    if (!(ctrl & ALI1563_SMB_IOEN)) {
        dev_warn(&dev->dev, "I/O space not enabled, trying manually\n");
        pci_write_config_word(dev, ALI1563_SMBBA,
                      ctrl | ALI1563_SMB_IOEN);
        pci_read_config_word(dev, ALI1563_SMBBA, &ctrl);
        if (!(ctrl & ALI1563_SMB_IOEN)) {
            dev_err(&dev->dev, "I/O space still not enabled, "
                "giving up\n");
            goto Err;
        }
    }

    if (acpi_check_region(ali1563_smba, ALI1563_SMB_IOSIZE,
                  ali1563_pci_driver.name))
        goto Err;

    if (!request_region(ali1563_smba, ALI1563_SMB_IOSIZE,
                ali1563_pci_driver.name)) {
        dev_err(&dev->dev, "Could not allocate I/O space at 0x%04x\n",
            ali1563_smba);
        goto Err;
    }
    dev_info(&dev->dev, "Found ALi1563 SMBus at 0x%04x\n", ali1563_smba);

    return 0;
Err:
    return -ENODEV;
}

static void ali1563_shutdown(struct pci_dev *dev)
{
    release_region(ali1563_smba,ALI1563_SMB_IOSIZE);
}

static const struct i2c_algorithm ali1563_algorithm = {
    .smbus_xfer = ali1563_access,
    .functionality  = ali1563_func,
};

static struct i2c_adapter ali1563_adapter = {
    .owner  = THIS_MODULE,
    .class  = I2C_CLASS_HWMON | I2C_CLASS_SPD,
    .algo   = &ali1563_algorithm,
};

static int __devinit ali1563_probe(struct pci_dev * dev,
                const struct pci_device_id * id_table)
{
    int error;

    if ((error = ali1563_setup(dev)))
        goto exit;
    ali1563_adapter.dev.parent = &dev->dev;
    snprintf(ali1563_adapter.name, sizeof(ali1563_adapter.name),
         "SMBus ALi 1563 Adapter @ %04x", ali1563_smba);
    if ((error = i2c_add_adapter(&ali1563_adapter)))
        goto exit_shutdown;
    return 0;

exit_shutdown:
    ali1563_shutdown(dev);
exit:
    dev_warn(&dev->dev, "ALi1563 SMBus probe failed (%d)\n", error);
    return error;
}

static void __devexit ali1563_remove(struct pci_dev * dev)
{
    i2c_del_adapter(&ali1563_adapter);
    ali1563_shutdown(dev);
}

static DEFINE_PCI_DEVICE_TABLE(ali1563_id_table) = {
    { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1563) },
    {},
};

MODULE_DEVICE_TABLE (pci, ali1563_id_table);

static struct pci_driver ali1563_pci_driver = {
    .name       = "ali1563_smbus",
    .id_table   = ali1563_id_table,
    .probe      = ali1563_probe,
    .remove     = __devexit_p(ali1563_remove),
};

module_pci_driver(ali1563_pci_driver);

MODULE_LICENSE("GPL");