i2c-nforce2.c

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/*
    SMBus driver for nVidia nForce2 MCP

    Added nForce3 Pro 150  Thomas Leibold <[email protected]>,
    Ported to 2.5 Patrick Dreker <[email protected]>,
    Copyright (c) 2003  Hans-Frieder Vogt <[email protected]>,
    Based on
    SMBus 2.0 driver for AMD-8111 IO-Hub
    Copyright (c) 2002 Vojtech Pavlik

    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.
*/

/*
    SUPPORTED DEVICES       PCI ID
    nForce2 MCP         0064
    nForce2 Ultra 400 MCP   0084
    nForce3 Pro150 MCP      00D4
    nForce3 250Gb MCP       00E4
    nForce4 MCP         0052
    nForce4 MCP-04      0034
    nForce MCP51        0264
    nForce MCP55        0368
    nForce MCP61        03EB
    nForce MCP65        0446
    nForce MCP67        0542
    nForce MCP73        07D8
    nForce MCP78S       0752
    nForce MCP79        0AA2

    This driver supports the 2 SMBuses that are included in the MCP of the
    nForce2/3/4/5xx chipsets.
*/

/* Note: we assume there can only be one nForce2, with two SMBus interfaces */

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

MODULE_LICENSE("GPL");
MODULE_AUTHOR ("Hans-Frieder Vogt <[email protected]>");
MODULE_DESCRIPTION("nForce2/3/4/5xx SMBus driver");


struct nforce2_smbus {
    struct i2c_adapter adapter;
    int base;
    int size;
    int blockops;
    int can_abort;
};


/*
 * nVidia nForce2 SMBus control register definitions
 * (Newer incarnations use standard BARs 4 and 5 instead)
 */
#define NFORCE_PCI_SMB1 0x50
#define NFORCE_PCI_SMB2 0x54


/*
 * ACPI 2.0 chapter 13 SMBus 2.0 EC register model
 */
#define NVIDIA_SMB_PRTCL    (smbus->base + 0x00)    /* protocol, PEC */
#define NVIDIA_SMB_STS      (smbus->base + 0x01)    /* status */
#define NVIDIA_SMB_ADDR     (smbus->base + 0x02)    /* address */
#define NVIDIA_SMB_CMD      (smbus->base + 0x03)    /* command */
#define NVIDIA_SMB_DATA     (smbus->base + 0x04)    /* 32 data registers */
#define NVIDIA_SMB_BCNT     (smbus->base + 0x24)    /* number of data
                               bytes */
#define NVIDIA_SMB_STATUS_ABRT  (smbus->base + 0x3c)    /* register used to
                               check the status of
                               the abort command */
#define NVIDIA_SMB_CTRL     (smbus->base + 0x3e)    /* control register */

#define NVIDIA_SMB_STATUS_ABRT_STS  0x01        /* Bit to notify that
                               abort succeeded */
#define NVIDIA_SMB_CTRL_ABORT   0x20
#define NVIDIA_SMB_STS_DONE 0x80
#define NVIDIA_SMB_STS_ALRM 0x40
#define NVIDIA_SMB_STS_RES  0x20
#define NVIDIA_SMB_STS_STATUS   0x1f

#define NVIDIA_SMB_PRTCL_WRITE          0x00
#define NVIDIA_SMB_PRTCL_READ           0x01
#define NVIDIA_SMB_PRTCL_QUICK          0x02
#define NVIDIA_SMB_PRTCL_BYTE           0x04
#define NVIDIA_SMB_PRTCL_BYTE_DATA      0x06
#define NVIDIA_SMB_PRTCL_WORD_DATA      0x08
#define NVIDIA_SMB_PRTCL_BLOCK_DATA     0x0a
#define NVIDIA_SMB_PRTCL_PEC            0x80

/* Misc definitions */
#define MAX_TIMEOUT 100

/* We disable the second SMBus channel on these boards */
static struct dmi_system_id __devinitdata nforce2_dmi_blacklist2[] = {
    {
        .ident = "DFI Lanparty NF4 Expert",
        .matches = {
            DMI_MATCH(DMI_BOARD_VENDOR, "DFI Corp,LTD"),
            DMI_MATCH(DMI_BOARD_NAME, "LP UT NF4 Expert"),
        },
    },
    { }
};

static struct pci_driver nforce2_driver;

/* For multiplexing support, we need a global reference to the 1st
   SMBus channel */
#if defined CONFIG_I2C_NFORCE2_S4985 || defined CONFIG_I2C_NFORCE2_S4985_MODULE
struct i2c_adapter *nforce2_smbus;
EXPORT_SYMBOL_GPL(nforce2_smbus);

static void nforce2_set_reference(struct i2c_adapter *adap)
{
    nforce2_smbus = adap;
}
#else
static inline void nforce2_set_reference(struct i2c_adapter *adap) { }
#endif

static void nforce2_abort(struct i2c_adapter *adap)
{
    struct nforce2_smbus *smbus = adap->algo_data;
    int timeout = 0;
    unsigned char temp;

    dev_dbg(&adap->dev, "Aborting current transaction\n");

    outb_p(NVIDIA_SMB_CTRL_ABORT, NVIDIA_SMB_CTRL);
    do {
        msleep(1);
        temp = inb_p(NVIDIA_SMB_STATUS_ABRT);
    } while (!(temp & NVIDIA_SMB_STATUS_ABRT_STS) &&
            (timeout++ < MAX_TIMEOUT));
    if (!(temp & NVIDIA_SMB_STATUS_ABRT_STS))
        dev_err(&adap->dev, "Can't reset the smbus\n");
    outb_p(NVIDIA_SMB_STATUS_ABRT_STS, NVIDIA_SMB_STATUS_ABRT);
}

static int nforce2_check_status(struct i2c_adapter *adap)
{
    struct nforce2_smbus *smbus = adap->algo_data;
    int timeout = 0;
    unsigned char temp;

    do {
        msleep(1);
        temp = inb_p(NVIDIA_SMB_STS);
    } while ((!temp) && (timeout++ < MAX_TIMEOUT));

    if (timeout > MAX_TIMEOUT) {
        dev_dbg(&adap->dev, "SMBus Timeout!\n");
        if (smbus->can_abort)
            nforce2_abort(adap);
        return -ETIMEDOUT;
    }
    if (!(temp & NVIDIA_SMB_STS_DONE) || (temp & NVIDIA_SMB_STS_STATUS)) {
        dev_dbg(&adap->dev, "Transaction failed (0x%02x)!\n", temp);
        return -EIO;
    }
    return 0;
}

/* Return negative errno on error */
static s32 nforce2_access(struct i2c_adapter * adap, u16 addr,
        unsigned short flags, char read_write,
        u8 command, int size, union i2c_smbus_data * data)
{
    struct nforce2_smbus *smbus = adap->algo_data;
    unsigned char protocol, pec;
    u8 len;
    int i, status;

    protocol = (read_write == I2C_SMBUS_READ) ? NVIDIA_SMB_PRTCL_READ :
        NVIDIA_SMB_PRTCL_WRITE;
    pec = (flags & I2C_CLIENT_PEC) ? NVIDIA_SMB_PRTCL_PEC : 0;

    switch (size) {

        case I2C_SMBUS_QUICK:
            protocol |= NVIDIA_SMB_PRTCL_QUICK;
            read_write = I2C_SMBUS_WRITE;
            break;

        case I2C_SMBUS_BYTE:
            if (read_write == I2C_SMBUS_WRITE)
                outb_p(command, NVIDIA_SMB_CMD);
            protocol |= NVIDIA_SMB_PRTCL_BYTE;
            break;

        case I2C_SMBUS_BYTE_DATA:
            outb_p(command, NVIDIA_SMB_CMD);
            if (read_write == I2C_SMBUS_WRITE)
                outb_p(data->byte, NVIDIA_SMB_DATA);
            protocol |= NVIDIA_SMB_PRTCL_BYTE_DATA;
            break;

        case I2C_SMBUS_WORD_DATA:
            outb_p(command, NVIDIA_SMB_CMD);
            if (read_write == I2C_SMBUS_WRITE) {
                 outb_p(data->word, NVIDIA_SMB_DATA);
                 outb_p(data->word >> 8, NVIDIA_SMB_DATA+1);
            }
            protocol |= NVIDIA_SMB_PRTCL_WORD_DATA | pec;
            break;

        case I2C_SMBUS_BLOCK_DATA:
            outb_p(command, NVIDIA_SMB_CMD);
            if (read_write == I2C_SMBUS_WRITE) {
                len = data->block[0];
                if ((len == 0) || (len > I2C_SMBUS_BLOCK_MAX)) {
                    dev_err(&adap->dev,
                        "Transaction failed "
                        "(requested block size: %d)\n",
                        len);
                    return -EINVAL;
                }
                outb_p(len, NVIDIA_SMB_BCNT);
                for (i = 0; i < I2C_SMBUS_BLOCK_MAX; i++)
                    outb_p(data->block[i + 1],
                           NVIDIA_SMB_DATA+i);
            }
            protocol |= NVIDIA_SMB_PRTCL_BLOCK_DATA | pec;
            break;

        default:
            dev_err(&adap->dev, "Unsupported transaction %d\n", size);
            return -EOPNOTSUPP;
    }

    outb_p((addr & 0x7f) << 1, NVIDIA_SMB_ADDR);
    outb_p(protocol, NVIDIA_SMB_PRTCL);

    status = nforce2_check_status(adap);
    if (status)
        return status;

    if (read_write == I2C_SMBUS_WRITE)
        return 0;

    switch (size) {

        case I2C_SMBUS_BYTE:
        case I2C_SMBUS_BYTE_DATA:
            data->byte = inb_p(NVIDIA_SMB_DATA);
            break;

        case I2C_SMBUS_WORD_DATA:
            data->word = inb_p(NVIDIA_SMB_DATA) | (inb_p(NVIDIA_SMB_DATA+1) << 8);
            break;

        case I2C_SMBUS_BLOCK_DATA:
            len = inb_p(NVIDIA_SMB_BCNT);
            if ((len <= 0) || (len > I2C_SMBUS_BLOCK_MAX)) {
                dev_err(&adap->dev, "Transaction failed "
                    "(received block size: 0x%02x)\n",
                    len);
                return -EPROTO;
            }
            for (i = 0; i < len; i++)
                data->block[i+1] = inb_p(NVIDIA_SMB_DATA + i);
            data->block[0] = len;
            break;
    }

    return 0;
}


static u32 nforce2_func(struct i2c_adapter *adapter)
{
    /* other functionality might be possible, but is not tested */
    return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
           I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
           I2C_FUNC_SMBUS_PEC |
           (((struct nforce2_smbus*)adapter->algo_data)->blockops ?
        I2C_FUNC_SMBUS_BLOCK_DATA : 0);
}

static struct i2c_algorithm smbus_algorithm = {
    .smbus_xfer = nforce2_access,
    .functionality  = nforce2_func,
};


static DEFINE_PCI_DEVICE_TABLE(nforce2_ids) = {
    { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE2_SMBUS) },
    { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE2S_SMBUS) },
    { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE3_SMBUS) },
    { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE3S_SMBUS) },
    { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE4_SMBUS) },
    { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP04_SMBUS) },
    { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP51_SMBUS) },
    { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP55_SMBUS) },
    { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP61_SMBUS) },
    { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP65_SMBUS) },
    { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP67_SMBUS) },
    { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP73_SMBUS) },
    { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP78S_SMBUS) },
    { PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP79_SMBUS) },
    { 0 }
};

MODULE_DEVICE_TABLE (pci, nforce2_ids);


static int __devinit nforce2_probe_smb (struct pci_dev *dev, int bar,
    int alt_reg, struct nforce2_smbus *smbus, const char *name)
{
    int error;

    smbus->base = pci_resource_start(dev, bar);
    if (smbus->base) {
        smbus->size = pci_resource_len(dev, bar);
    } else {
        /* Older incarnations of the device used non-standard BARs */
        u16 iobase;

        if (pci_read_config_word(dev, alt_reg, &iobase)
            != PCIBIOS_SUCCESSFUL) {
            dev_err(&dev->dev, "Error reading PCI config for %s\n",
                name);
            return -EIO;
        }

        smbus->base = iobase & PCI_BASE_ADDRESS_IO_MASK;
        smbus->size = 64;
    }

    error = acpi_check_region(smbus->base, smbus->size,
                  nforce2_driver.name);
    if (error)
        return error;

    if (!request_region(smbus->base, smbus->size, nforce2_driver.name)) {
        dev_err(&smbus->adapter.dev, "Error requesting region %02x .. %02X for %s\n",
            smbus->base, smbus->base+smbus->size-1, name);
        return -EBUSY;
    }
    smbus->adapter.owner = THIS_MODULE;
    smbus->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
    smbus->adapter.algo = &smbus_algorithm;
    smbus->adapter.algo_data = smbus;
    smbus->adapter.dev.parent = &dev->dev;
    snprintf(smbus->adapter.name, sizeof(smbus->adapter.name),
        "SMBus nForce2 adapter at %04x", smbus->base);

    error = i2c_add_adapter(&smbus->adapter);
    if (error) {
        dev_err(&smbus->adapter.dev, "Failed to register adapter.\n");
        release_region(smbus->base, smbus->size);
        return error;
    }
    dev_info(&smbus->adapter.dev, "nForce2 SMBus adapter at %#x\n", smbus->base);
    return 0;
}


static int __devinit nforce2_probe(struct pci_dev *dev, const struct pci_device_id *id)
{
    struct nforce2_smbus *smbuses;
    int res1, res2;

    /* we support 2 SMBus adapters */
    if (!(smbuses = kzalloc(2*sizeof(struct nforce2_smbus), GFP_KERNEL)))
        return -ENOMEM;
    pci_set_drvdata(dev, smbuses);

    switch(dev->device) {
    case PCI_DEVICE_ID_NVIDIA_NFORCE2_SMBUS:
    case PCI_DEVICE_ID_NVIDIA_NFORCE_MCP51_SMBUS:
    case PCI_DEVICE_ID_NVIDIA_NFORCE_MCP55_SMBUS:
        smbuses[0].blockops = 1;
        smbuses[1].blockops = 1;
        smbuses[0].can_abort = 1;
        smbuses[1].can_abort = 1;
    }

    /* SMBus adapter 1 */
    res1 = nforce2_probe_smb(dev, 4, NFORCE_PCI_SMB1, &smbuses[0], "SMB1");
    if (res1 < 0)
        smbuses[0].base = 0;    /* to have a check value */

    /* SMBus adapter 2 */
    if (dmi_check_system(nforce2_dmi_blacklist2)) {
        dev_err(&dev->dev, "Disabling SMB2 for safety reasons.\n");
        res2 = -EPERM;
        smbuses[1].base = 0;
    } else {
        res2 = nforce2_probe_smb(dev, 5, NFORCE_PCI_SMB2, &smbuses[1],
                     "SMB2");
        if (res2 < 0)
            smbuses[1].base = 0;    /* to have a check value */
    }

    if ((res1 < 0) && (res2 < 0)) {
        /* we did not find even one of the SMBuses, so we give up */
        kfree(smbuses);
        return -ENODEV;
    }

    nforce2_set_reference(&smbuses[0].adapter);
    return 0;
}


static void __devexit nforce2_remove(struct pci_dev *dev)
{
    struct nforce2_smbus *smbuses = pci_get_drvdata(dev);

    nforce2_set_reference(NULL);
    if (smbuses[0].base) {
        i2c_del_adapter(&smbuses[0].adapter);
        release_region(smbuses[0].base, smbuses[0].size);
    }
    if (smbuses[1].base) {
        i2c_del_adapter(&smbuses[1].adapter);
        release_region(smbuses[1].base, smbuses[1].size);
    }
    kfree(smbuses);
}

static struct pci_driver nforce2_driver = {
    .name       = "nForce2_smbus",
    .id_table   = nforce2_ids,
    .probe      = nforce2_probe,
    .remove     = __devexit_p(nforce2_remove),
};

module_pci_driver(nforce2_driver);