i2c-amd756.c

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/*
    Copyright (c) 1999-2002 Merlin Hughes <[email protected]>

    Shamelessly ripped from i2c-piix4.c:

    Copyright (c) 1998, 1999  Frodo Looijaard <[email protected]> and
    Philip Edelbrock <[email protected]>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

/*
    2002-04-08: Added nForce support. (Csaba Halasz)
    2002-10-03: Fixed nForce PnP I/O port. (Michael Steil)
    2002-12-28: Rewritten into something that resembles a Linux driver (hch)
    2003-11-29: Added back AMD8111 removed by the previous rewrite.
                (Philip Pokorny)
*/

/*
   Supports AMD756, AMD766, AMD768, AMD8111 and nVidia nForce
   Note: we assume there can only be one device, with one SMBus interface.
*/

#include <linux/module.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/stddef.h>
#include <linux/ioport.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/acpi.h>
#include <linux/io.h>

/* AMD756 SMBus address offsets */
#define SMB_ADDR_OFFSET     0xE0
#define SMB_IOSIZE      16
#define SMB_GLOBAL_STATUS   (0x0 + amd756_ioport)
#define SMB_GLOBAL_ENABLE   (0x2 + amd756_ioport)
#define SMB_HOST_ADDRESS    (0x4 + amd756_ioport)
#define SMB_HOST_DATA       (0x6 + amd756_ioport)
#define SMB_HOST_COMMAND    (0x8 + amd756_ioport)
#define SMB_HOST_BLOCK_DATA (0x9 + amd756_ioport)
#define SMB_HAS_DATA        (0xA + amd756_ioport)
#define SMB_HAS_DEVICE_ADDRESS  (0xC + amd756_ioport)
#define SMB_HAS_HOST_ADDRESS    (0xE + amd756_ioport)
#define SMB_SNOOP_ADDRESS   (0xF + amd756_ioport)

/* PCI Address Constants */

/* address of I/O space */
#define SMBBA       0x058       /* mh */
#define SMBBANFORCE 0x014

/* general configuration */
#define SMBGCFG     0x041       /* mh */

/* silicon revision code */
#define SMBREV      0x008

/* Other settings */
#define MAX_TIMEOUT 500

/* AMD756 constants */
#define AMD756_QUICK        0x00
#define AMD756_BYTE     0x01
#define AMD756_BYTE_DATA    0x02
#define AMD756_WORD_DATA    0x03
#define AMD756_PROCESS_CALL 0x04
#define AMD756_BLOCK_DATA   0x05

static struct pci_driver amd756_driver;
static unsigned short amd756_ioport;

/* 
  SMBUS event = I/O 28-29 bit 11
     see E0 for the status bits and enabled in E2
     
*/
#define GS_ABRT_STS (1 << 0)
#define GS_COL_STS  (1 << 1)
#define GS_PRERR_STS    (1 << 2)
#define GS_HST_STS  (1 << 3)
#define GS_HCYC_STS (1 << 4)
#define GS_TO_STS   (1 << 5)
#define GS_SMB_STS  (1 << 11)

#define GS_CLEAR_STS    (GS_ABRT_STS | GS_COL_STS | GS_PRERR_STS | \
             GS_HCYC_STS | GS_TO_STS )

#define GE_CYC_TYPE_MASK    (7)
#define GE_HOST_STC     (1 << 3)
#define GE_ABORT        (1 << 5)


static int amd756_transaction(struct i2c_adapter *adap)
{
    int temp;
    int result = 0;
    int timeout = 0;

    dev_dbg(&adap->dev, "Transaction (pre): GS=%04x, GE=%04x, ADD=%04x, "
        "DAT=%04x\n", inw_p(SMB_GLOBAL_STATUS),
        inw_p(SMB_GLOBAL_ENABLE), inw_p(SMB_HOST_ADDRESS),
        inb_p(SMB_HOST_DATA));

    /* Make sure the SMBus host is ready to start transmitting */
    if ((temp = inw_p(SMB_GLOBAL_STATUS)) & (GS_HST_STS | GS_SMB_STS)) {
        dev_dbg(&adap->dev, "SMBus busy (%04x). Waiting...\n", temp);
        do {
            msleep(1);
            temp = inw_p(SMB_GLOBAL_STATUS);
        } while ((temp & (GS_HST_STS | GS_SMB_STS)) &&
                 (timeout++ < MAX_TIMEOUT));
        /* If the SMBus is still busy, we give up */
        if (timeout > MAX_TIMEOUT) {
            dev_dbg(&adap->dev, "Busy wait timeout (%04x)\n", temp);
            goto abort;
        }
        timeout = 0;
    }

    /* start the transaction by setting the start bit */
    outw_p(inw(SMB_GLOBAL_ENABLE) | GE_HOST_STC, SMB_GLOBAL_ENABLE);

    /* We will always wait for a fraction of a second! */
    do {
        msleep(1);
        temp = inw_p(SMB_GLOBAL_STATUS);
    } while ((temp & GS_HST_STS) && (timeout++ < MAX_TIMEOUT));

    /* If the SMBus is still busy, we give up */
    if (timeout > MAX_TIMEOUT) {
        dev_dbg(&adap->dev, "Completion timeout!\n");
        goto abort;
    }

    if (temp & GS_PRERR_STS) {
        result = -ENXIO;
        dev_dbg(&adap->dev, "SMBus Protocol error (no response)!\n");
    }

    if (temp & GS_COL_STS) {
        result = -EIO;
        dev_warn(&adap->dev, "SMBus collision!\n");
    }

    if (temp & GS_TO_STS) {
        result = -ETIMEDOUT;
        dev_dbg(&adap->dev, "SMBus protocol timeout!\n");
    }

    if (temp & GS_HCYC_STS)
        dev_dbg(&adap->dev, "SMBus protocol success!\n");

    outw_p(GS_CLEAR_STS, SMB_GLOBAL_STATUS);

#ifdef DEBUG
    if (((temp = inw_p(SMB_GLOBAL_STATUS)) & GS_CLEAR_STS) != 0x00) {
        dev_dbg(&adap->dev,
            "Failed reset at end of transaction (%04x)\n", temp);
    }
#endif

    dev_dbg(&adap->dev,
        "Transaction (post): GS=%04x, GE=%04x, ADD=%04x, DAT=%04x\n",
        inw_p(SMB_GLOBAL_STATUS), inw_p(SMB_GLOBAL_ENABLE),
        inw_p(SMB_HOST_ADDRESS), inb_p(SMB_HOST_DATA));

    return result;

 abort:
    dev_warn(&adap->dev, "Sending abort\n");
    outw_p(inw(SMB_GLOBAL_ENABLE) | GE_ABORT, SMB_GLOBAL_ENABLE);
    msleep(100);
    outw_p(GS_CLEAR_STS, SMB_GLOBAL_STATUS);
    return -EIO;
}

/* Return negative errno on error. */
static s32 amd756_access(struct i2c_adapter * adap, u16 addr,
          unsigned short flags, char read_write,
          u8 command, int size, union i2c_smbus_data * data)
{
    int i, len;
    int status;

    switch (size) {
    case I2C_SMBUS_QUICK:
        outw_p(((addr & 0x7f) << 1) | (read_write & 0x01),
               SMB_HOST_ADDRESS);
        size = AMD756_QUICK;
        break;
    case I2C_SMBUS_BYTE:
        outw_p(((addr & 0x7f) << 1) | (read_write & 0x01),
               SMB_HOST_ADDRESS);
        if (read_write == I2C_SMBUS_WRITE)
            outb_p(command, SMB_HOST_DATA);
        size = AMD756_BYTE;
        break;
    case I2C_SMBUS_BYTE_DATA:
        outw_p(((addr & 0x7f) << 1) | (read_write & 0x01),
               SMB_HOST_ADDRESS);
        outb_p(command, SMB_HOST_COMMAND);
        if (read_write == I2C_SMBUS_WRITE)
            outw_p(data->byte, SMB_HOST_DATA);
        size = AMD756_BYTE_DATA;
        break;
    case I2C_SMBUS_WORD_DATA:
        outw_p(((addr & 0x7f) << 1) | (read_write & 0x01),
               SMB_HOST_ADDRESS);
        outb_p(command, SMB_HOST_COMMAND);
        if (read_write == I2C_SMBUS_WRITE)
            outw_p(data->word, SMB_HOST_DATA);  /* TODO: endian???? */
        size = AMD756_WORD_DATA;
        break;
    case I2C_SMBUS_BLOCK_DATA:
        outw_p(((addr & 0x7f) << 1) | (read_write & 0x01),
               SMB_HOST_ADDRESS);
        outb_p(command, SMB_HOST_COMMAND);
        if (read_write == I2C_SMBUS_WRITE) {
            len = data->block[0];
            if (len < 0)
                len = 0;
            if (len > 32)
                len = 32;
            outw_p(len, SMB_HOST_DATA);
            /* i = inw_p(SMBHSTCNT); Reset SMBBLKDAT */
            for (i = 1; i <= len; i++)
                outb_p(data->block[i],
                       SMB_HOST_BLOCK_DATA);
        }
        size = AMD756_BLOCK_DATA;
        break;
    default:
        dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
        return -EOPNOTSUPP;
    }

    /* How about enabling interrupts... */
    outw_p(size & GE_CYC_TYPE_MASK, SMB_GLOBAL_ENABLE);

    status = amd756_transaction(adap);
    if (status)
        return status;

    if ((read_write == I2C_SMBUS_WRITE) || (size == AMD756_QUICK))
        return 0;


    switch (size) {
    case AMD756_BYTE:
        data->byte = inw_p(SMB_HOST_DATA);
        break;
    case AMD756_BYTE_DATA:
        data->byte = inw_p(SMB_HOST_DATA);
        break;
    case AMD756_WORD_DATA:
        data->word = inw_p(SMB_HOST_DATA);  /* TODO: endian???? */
        break;
    case AMD756_BLOCK_DATA:
        data->block[0] = inw_p(SMB_HOST_DATA) & 0x3f;
        if(data->block[0] > 32)
            data->block[0] = 32;
        /* i = inw_p(SMBHSTCNT); Reset SMBBLKDAT */
        for (i = 1; i <= data->block[0]; i++)
            data->block[i] = inb_p(SMB_HOST_BLOCK_DATA);
        break;
    }

    return 0;
}

static u32 amd756_func(struct i2c_adapter *adapter)
{
    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 const struct i2c_algorithm smbus_algorithm = {
    .smbus_xfer = amd756_access,
    .functionality  = amd756_func,
};

struct i2c_adapter amd756_smbus = {
    .owner      = THIS_MODULE,
    .class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
    .algo       = &smbus_algorithm,
};

enum chiptype { AMD756, AMD766, AMD768, NFORCE, AMD8111 };
static const char* chipname[] = {
    "AMD756", "AMD766", "AMD768",
    "nVidia nForce", "AMD8111",
};

static DEFINE_PCI_DEVICE_TABLE(amd756_ids) = {
    { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_VIPER_740B),
      .driver_data = AMD756 },
    { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_VIPER_7413),
      .driver_data = AMD766 },
    { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_OPUS_7443),
      .driver_data = AMD768 },
    { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_8111_SMBUS),
      .driver_data = AMD8111 },
    { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_SMBUS),
      .driver_data = NFORCE },
    { 0, }
};

MODULE_DEVICE_TABLE (pci, amd756_ids);

static int __devinit amd756_probe(struct pci_dev *pdev,
                  const struct pci_device_id *id)
{
    int nforce = (id->driver_data == NFORCE);
    int error;
    u8 temp;
    
    if (amd756_ioport) {
        dev_err(&pdev->dev, "Only one device supported "
               "(you have a strange motherboard, btw)\n");
        return -ENODEV;
    }

    if (nforce) {
        if (PCI_FUNC(pdev->devfn) != 1)
            return -ENODEV;

        pci_read_config_word(pdev, SMBBANFORCE, &amd756_ioport);
        amd756_ioport &= 0xfffc;
    } else { /* amd */
        if (PCI_FUNC(pdev->devfn) != 3)
            return -ENODEV;

        pci_read_config_byte(pdev, SMBGCFG, &temp);
        if ((temp & 128) == 0) {
            dev_err(&pdev->dev,
                "Error: SMBus controller I/O not enabled!\n");
            return -ENODEV;
        }

        /* Determine the address of the SMBus areas */
        /* Technically it is a dword but... */
        pci_read_config_word(pdev, SMBBA, &amd756_ioport);
        amd756_ioport &= 0xff00;
        amd756_ioport += SMB_ADDR_OFFSET;
    }

    error = acpi_check_region(amd756_ioport, SMB_IOSIZE,
                  amd756_driver.name);
    if (error)
        return -ENODEV;

    if (!request_region(amd756_ioport, SMB_IOSIZE, amd756_driver.name)) {
        dev_err(&pdev->dev, "SMB region 0x%x already in use!\n",
            amd756_ioport);
        return -ENODEV;
    }

    pci_read_config_byte(pdev, SMBREV, &temp);
    dev_dbg(&pdev->dev, "SMBREV = 0x%X\n", temp);
    dev_dbg(&pdev->dev, "AMD756_smba = 0x%X\n", amd756_ioport);

    /* set up the sysfs linkage to our parent device */
    amd756_smbus.dev.parent = &pdev->dev;

    snprintf(amd756_smbus.name, sizeof(amd756_smbus.name),
         "SMBus %s adapter at %04x", chipname[id->driver_data],
         amd756_ioport);

    error = i2c_add_adapter(&amd756_smbus);
    if (error) {
        dev_err(&pdev->dev,
            "Adapter registration failed, module not inserted\n");
        goto out_err;
    }

    return 0;

 out_err:
    release_region(amd756_ioport, SMB_IOSIZE);
    return error;
}

static void __devexit amd756_remove(struct pci_dev *dev)
{
    i2c_del_adapter(&amd756_smbus);
    release_region(amd756_ioport, SMB_IOSIZE);
}

static struct pci_driver amd756_driver = {
    .name       = "amd756_smbus",
    .id_table   = amd756_ids,
    .probe      = amd756_probe,
    .remove     = __devexit_p(amd756_remove),
};

module_pci_driver(amd756_driver);

MODULE_AUTHOR("Merlin Hughes <[email protected]>");
MODULE_DESCRIPTION("AMD756/766/768/8111 and nVidia nForce SMBus driver");
MODULE_LICENSE("GPL");

EXPORT_SYMBOL(amd756_smbus);