drivers/i2c/busses/i2c-piix4.c - kernel/bruno - Git at Google

 /*
     Copyright (c) 1998 - 2002 Frodo Looijaard <frodol@dds.nl> and
     Philip Edelbrock <phil@netroedge.com>

     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.
 */

 /*
    Supports:
 	Intel PIIX4, 440MX
 	Serverworks OSB4, CSB5, CSB6, HT-1000, HT-1100
 	ATI IXP200, IXP300, IXP400, SB600, SB700/SP5100, SB800
 	AMD Hudson-2, ML, CZ
 	SMSC Victory66

    Note: we assume there can only be one device, with one or more
    SMBus interfaces.
 */

 #include <linux/module.h>
 #include <linux/moduleparam.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/slab.h>
 #include <linux/dmi.h>
 #include <linux/acpi.h>
 #include <linux/io.h>


 /* PIIX4 SMBus address offsets */
 #define SMBHSTSTS	(0 + piix4_smba)
 #define SMBHSLVSTS	(1 + piix4_smba)
 #define SMBHSTCNT	(2 + piix4_smba)
 #define SMBHSTCMD	(3 + piix4_smba)
 #define SMBHSTADD	(4 + piix4_smba)
 #define SMBHSTDAT0	(5 + piix4_smba)
 #define SMBHSTDAT1	(6 + piix4_smba)
 #define SMBBLKDAT	(7 + piix4_smba)
 #define SMBSLVCNT	(8 + piix4_smba)
 #define SMBSHDWCMD	(9 + piix4_smba)
 #define SMBSLVEVT	(0xA + piix4_smba)
 #define SMBSLVDAT	(0xC + piix4_smba)

 /* count for request_region */
 #define SMBIOSIZE	8

 /* PCI Address Constants */
 #define SMBBA		0x090
 #define SMBHSTCFG	0x0D2
 #define SMBSLVC		0x0D3
 #define SMBSHDW1	0x0D4
 #define SMBSHDW2	0x0D5
 #define SMBREV		0x0D6

 /* Other settings */
 #define MAX_TIMEOUT	500
 #define  ENABLE_INT9	0

 /* PIIX4 constants */
 #define PIIX4_QUICK		0x00
 #define PIIX4_BYTE		0x04
 #define PIIX4_BYTE_DATA		0x08
 #define PIIX4_WORD_DATA		0x0C
 #define PIIX4_BLOCK_DATA	0x14

 /* insmod parameters */

 /* If force is set to anything different from 0, we forcibly enable the
    PIIX4. DANGEROUS! */
 static int force;
 module_param (force, int, 0);
 MODULE_PARM_DESC(force, "Forcibly enable the PIIX4. DANGEROUS!");

 /* If force_addr is set to anything different from 0, we forcibly enable
    the PIIX4 at the given address. VERY DANGEROUS! */
 static int force_addr;
 module_param (force_addr, int, 0);
 MODULE_PARM_DESC(force_addr,
 		 "Forcibly enable the PIIX4 at the given address. "
 		 "EXTREMELY DANGEROUS!");

 static int srvrworks_csb5_delay;
 static struct pci_driver piix4_driver;

 static const struct dmi_system_id piix4_dmi_blacklist[] = {
 	{
 		.ident = "Sapphire AM2RD790",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "SAPPHIRE Inc."),
 			DMI_MATCH(DMI_BOARD_NAME, "PC-AM2RD790"),
 		},
 	},
 	{
 		.ident = "DFI Lanparty UT 790FX",
 		.matches = {
 			DMI_MATCH(DMI_BOARD_VENDOR, "DFI Inc."),
 			DMI_MATCH(DMI_BOARD_NAME, "LP UT 790FX"),
 		},
 	},
 	{ }
 };

 /* The IBM entry is in a separate table because we only check it
    on Intel-based systems */
 static const struct dmi_system_id piix4_dmi_ibm[] = {
 	{
 		.ident = "IBM",
 		.matches = { DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
 	},
 	{ },
 };

 struct i2c_piix4_adapdata {
 	unsigned short smba;
 };

 static int piix4_setup(struct pci_dev *PIIX4_dev,
 		       const struct pci_device_id *id)
 {
 	unsigned char temp;
 	unsigned short piix4_smba;

 	if ((PIIX4_dev->vendor == PCI_VENDOR_ID_SERVERWORKS) &&
 	    (PIIX4_dev->device == PCI_DEVICE_ID_SERVERWORKS_CSB5))
 		srvrworks_csb5_delay = 1;

 	/* On some motherboards, it was reported that accessing the SMBus
 	   caused severe hardware problems */
 	if (dmi_check_system(piix4_dmi_blacklist)) {
 		dev_err(&PIIX4_dev->dev,
 			"Accessing the SMBus on this system is unsafe!\n");
 		return -EPERM;
 	}

 	/* Don't access SMBus on IBM systems which get corrupted eeproms */
 	if (dmi_check_system(piix4_dmi_ibm) &&
 			PIIX4_dev->vendor == PCI_VENDOR_ID_INTEL) {
 		dev_err(&PIIX4_dev->dev, "IBM system detected; this module "
 			"may corrupt your serial eeprom! Refusing to load "
 			"module!\n");
 		return -EPERM;
 	}

 	/* Determine the address of the SMBus areas */
 	if (force_addr) {
 		piix4_smba = force_addr & 0xfff0;
 		force = 0;
 	} else {
 		pci_read_config_word(PIIX4_dev, SMBBA, &piix4_smba);
 		piix4_smba &= 0xfff0;
 		if(piix4_smba == 0) {
 			dev_err(&PIIX4_dev->dev, "SMBus base address "
 				"uninitialized - upgrade BIOS or use "
 				"force_addr=0xaddr\n");
 			return -ENODEV;
 		}
 	}

 	if (acpi_check_region(piix4_smba, SMBIOSIZE, piix4_driver.name))
 		return -ENODEV;

 	if (!request_region(piix4_smba, SMBIOSIZE, piix4_driver.name)) {
 		dev_err(&PIIX4_dev->dev, "SMBus region 0x%x already in use!\n",
 			piix4_smba);
 		return -EBUSY;
 	}

 	pci_read_config_byte(PIIX4_dev, SMBHSTCFG, &temp);

 	/* If force_addr is set, we program the new address here. Just to make
 	   sure, we disable the PIIX4 first. */
 	if (force_addr) {
 		pci_write_config_byte(PIIX4_dev, SMBHSTCFG, temp & 0xfe);
 		pci_write_config_word(PIIX4_dev, SMBBA, piix4_smba);
 		pci_write_config_byte(PIIX4_dev, SMBHSTCFG, temp | 0x01);
 		dev_info(&PIIX4_dev->dev, "WARNING: SMBus interface set to "
 			"new address %04x!\n", piix4_smba);
 	} else if ((temp & 1) == 0) {
 		if (force) {
 			/* This should never need to be done, but has been
 			 * noted that many Dell machines have the SMBus
 			 * interface on the PIIX4 disabled!? NOTE: This assumes
 			 * I/O space and other allocations WERE done by the
 			 * Bios!  Don't complain if your hardware does weird
 			 * things after enabling this. :') Check for Bios
 			 * updates before resorting to this.
 			 */
 			pci_write_config_byte(PIIX4_dev, SMBHSTCFG,
 					      temp | 1);
 			dev_notice(&PIIX4_dev->dev,
 				   "WARNING: SMBus interface has been FORCEFULLY ENABLED!\n");
 		} else {
 			dev_err(&PIIX4_dev->dev,
 				"SMBus Host Controller not enabled!\n");
 			release_region(piix4_smba, SMBIOSIZE);
 			return -ENODEV;
 		}
 	}

 	if (((temp & 0x0E) == 8) || ((temp & 0x0E) == 2))
 		dev_dbg(&PIIX4_dev->dev, "Using IRQ for SMBus\n");
 	else if ((temp & 0x0E) == 0)
 		dev_dbg(&PIIX4_dev->dev, "Using SMI# for SMBus\n");
 	else
 		dev_err(&PIIX4_dev->dev, "Illegal Interrupt configuration "
 			"(or code out of date)!\n");

 	pci_read_config_byte(PIIX4_dev, SMBREV, &temp);
 	dev_info(&PIIX4_dev->dev,
 		 "SMBus Host Controller at 0x%x, revision %d\n",
 		 piix4_smba, temp);

 	return piix4_smba;
 }

 static int piix4_setup_sb800(struct pci_dev *PIIX4_dev,
 			     const struct pci_device_id *id, u8 aux)
 {
 	unsigned short piix4_smba;
 	unsigned short smba_idx = 0xcd6;
 	u8 smba_en_lo, smba_en_hi, smb_en, smb_en_status;
 	u8 i2ccfg, i2ccfg_offset = 0x10;

 	/* SB800 and later SMBus does not support forcing address */
 	if (force || force_addr) {
 		dev_err(&PIIX4_dev->dev, "SMBus does not support "
 			"forcing address!\n");
 		return -EINVAL;
 	}

 	/* Determine the address of the SMBus areas */
 	if ((PIIX4_dev->vendor == PCI_VENDOR_ID_AMD &&
 	     PIIX4_dev->device == PCI_DEVICE_ID_AMD_HUDSON2_SMBUS &&
 	     PIIX4_dev->revision >= 0x41) ||
 	    (PIIX4_dev->vendor == PCI_VENDOR_ID_AMD &&
 	     PIIX4_dev->device == PCI_DEVICE_ID_AMD_KERNCZ_SMBUS &&
 	     PIIX4_dev->revision >= 0x49))
 		smb_en = 0x00;
 	else
 		smb_en = (aux) ? 0x28 : 0x2c;

 	if (!request_region(smba_idx, 2, "smba_idx")) {
 		dev_err(&PIIX4_dev->dev, "SMBus base address index region "
 			"0x%x already in use!\n", smba_idx);
 		return -EBUSY;
 	}
 	outb_p(smb_en, smba_idx);
 	smba_en_lo = inb_p(smba_idx + 1);
 	outb_p(smb_en + 1, smba_idx);
 	smba_en_hi = inb_p(smba_idx + 1);
 	release_region(smba_idx, 2);

 	if (!smb_en) {
 		smb_en_status = smba_en_lo & 0x10;
 		piix4_smba = smba_en_hi << 8;
 		if (aux)
 			piix4_smba |= 0x20;
 	} else {
 		smb_en_status = smba_en_lo & 0x01;
 		piix4_smba = ((smba_en_hi << 8) | smba_en_lo) & 0xffe0;
 	}

 	if (!smb_en_status) {
 		dev_err(&PIIX4_dev->dev,
 			"SMBus Host Controller not enabled!\n");
 		return -ENODEV;
 	}

 	if (acpi_check_region(piix4_smba, SMBIOSIZE, piix4_driver.name))
 		return -ENODEV;

 	if (!request_region(piix4_smba, SMBIOSIZE, piix4_driver.name)) {
 		dev_err(&PIIX4_dev->dev, "SMBus region 0x%x already in use!\n",
 			piix4_smba);
 		return -EBUSY;
 	}

 	/* Aux SMBus does not support IRQ information */
 	if (aux) {
 		dev_info(&PIIX4_dev->dev,
 			 "Auxiliary SMBus Host Controller at 0x%x\n",
 			 piix4_smba);
 		return piix4_smba;
 	}

 	/* Request the SMBus I2C bus config region */
 	if (!request_region(piix4_smba + i2ccfg_offset, 1, "i2ccfg")) {
 		dev_err(&PIIX4_dev->dev, "SMBus I2C bus config region "
 			"0x%x already in use!\n", piix4_smba + i2ccfg_offset);
 		release_region(piix4_smba, SMBIOSIZE);
 		return -EBUSY;
 	}
 	i2ccfg = inb_p(piix4_smba + i2ccfg_offset);
 	release_region(piix4_smba + i2ccfg_offset, 1);

 	if (i2ccfg & 1)
 		dev_dbg(&PIIX4_dev->dev, "Using IRQ for SMBus\n");
 	else
 		dev_dbg(&PIIX4_dev->dev, "Using SMI# for SMBus\n");

 	dev_info(&PIIX4_dev->dev,
 		 "SMBus Host Controller at 0x%x, revision %d\n",
 		 piix4_smba, i2ccfg >> 4);

 	return piix4_smba;
 }

 static int piix4_setup_aux(struct pci_dev *PIIX4_dev,
 			   const struct pci_device_id *id,
 			   unsigned short base_reg_addr)
 {
 	/* Set up auxiliary SMBus controllers found on some
 	 * AMD chipsets e.g. SP5100 (SB700 derivative) */

 	unsigned short piix4_smba;

 	/* Read address of auxiliary SMBus controller */
 	pci_read_config_word(PIIX4_dev, base_reg_addr, &piix4_smba);
 	if ((piix4_smba & 1) == 0) {
 		dev_dbg(&PIIX4_dev->dev,
 			"Auxiliary SMBus controller not enabled\n");
 		return -ENODEV;
 	}

 	piix4_smba &= 0xfff0;
 	if (piix4_smba == 0) {
 		dev_dbg(&PIIX4_dev->dev,
 			"Auxiliary SMBus base address uninitialized\n");
 		return -ENODEV;
 	}

 	if (acpi_check_region(piix4_smba, SMBIOSIZE, piix4_driver.name))
 		return -ENODEV;

 	if (!request_region(piix4_smba, SMBIOSIZE, piix4_driver.name)) {
 		dev_err(&PIIX4_dev->dev, "Auxiliary SMBus region 0x%x "
 			"already in use!\n", piix4_smba);
 		return -EBUSY;
 	}

 	dev_info(&PIIX4_dev->dev,
 		 "Auxiliary SMBus Host Controller at 0x%x\n",
 		 piix4_smba);

 	return piix4_smba;
 }

 static int piix4_transaction(struct i2c_adapter *piix4_adapter)
 {
 	struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(piix4_adapter);
 	unsigned short piix4_smba = adapdata->smba;
 	int temp;
 	int result = 0;
 	int timeout = 0;

 	dev_dbg(&piix4_adapter->dev, "Transaction (pre): CNT=%02x, CMD=%02x, "
 		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTCNT),
 		inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
 		inb_p(SMBHSTDAT1));

 	/* Make sure the SMBus host is ready to start transmitting */
 	if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
 		dev_dbg(&piix4_adapter->dev, "SMBus busy (%02x). "
 			"Resetting...\n", temp);
 		outb_p(temp, SMBHSTSTS);
 		if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
 			dev_err(&piix4_adapter->dev, "Failed! (%02x)\n", temp);
 			return -EBUSY;
 		} else {
 			dev_dbg(&piix4_adapter->dev, "Successful!\n");
 		}
 	}

 	/* start the transaction by setting bit 6 */
 	outb_p(inb(SMBHSTCNT) | 0x040, SMBHSTCNT);

 	/* We will always wait for a fraction of a second! (See PIIX4 docs errata) */
 	if (srvrworks_csb5_delay) /* Extra delay for SERVERWORKS_CSB5 */
 		msleep(2);
 	else
 		msleep(1);

 	while ((++timeout < MAX_TIMEOUT) &&
 	       ((temp = inb_p(SMBHSTSTS)) & 0x01))
 		msleep(1);

 	/* If the SMBus is still busy, we give up */
 	if (timeout == MAX_TIMEOUT) {
 		dev_err(&piix4_adapter->dev, "SMBus Timeout!\n");
 		result = -ETIMEDOUT;
 	}

 	if (temp & 0x10) {
 		result = -EIO;
 		dev_err(&piix4_adapter->dev, "Error: Failed bus transaction\n");
 	}

 	if (temp & 0x08) {
 		result = -EIO;
 		dev_dbg(&piix4_adapter->dev, "Bus collision! SMBus may be "
 			"locked until next hard reset. (sorry!)\n");
 		/* Clock stops and slave is stuck in mid-transmission */
 	}

 	if (temp & 0x04) {
 		result = -ENXIO;
 		dev_dbg(&piix4_adapter->dev, "Error: no response!\n");
 	}

 	if (inb_p(SMBHSTSTS) != 0x00)
 		outb_p(inb(SMBHSTSTS), SMBHSTSTS);

 	if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
 		dev_err(&piix4_adapter->dev, "Failed reset at end of "
 			"transaction (%02x)\n", temp);
 	}
 	dev_dbg(&piix4_adapter->dev, "Transaction (post): CNT=%02x, CMD=%02x, "
 		"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTCNT),
 		inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
 		inb_p(SMBHSTDAT1));
 	return result;
 }

 /* Return negative errno on error. */
 static s32 piix4_access(struct i2c_adapter * adap, u16 addr,
 		 unsigned short flags, char read_write,
 		 u8 command, int size, union i2c_smbus_data * data)
 {
 	struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(adap);
 	unsigned short piix4_smba = adapdata->smba;
 	int i, len;
 	int status;

 	switch (size) {
 	case I2C_SMBUS_QUICK:
 		outb_p((addr << 1) | read_write,
 		       SMBHSTADD);
 		size = PIIX4_QUICK;
 		break;
 	case I2C_SMBUS_BYTE:
 		outb_p((addr << 1) | read_write,
 		       SMBHSTADD);
 		if (read_write == I2C_SMBUS_WRITE)
 			outb_p(command, SMBHSTCMD);
 		size = PIIX4_BYTE;
 		break;
 	case I2C_SMBUS_BYTE_DATA:
 		outb_p((addr << 1) | read_write,
 		       SMBHSTADD);
 		outb_p(command, SMBHSTCMD);
 		if (read_write == I2C_SMBUS_WRITE)
 			outb_p(data->byte, SMBHSTDAT0);
 		size = PIIX4_BYTE_DATA;
 		break;
 	case I2C_SMBUS_WORD_DATA:
 		outb_p((addr << 1) | read_write,
 		       SMBHSTADD);
 		outb_p(command, SMBHSTCMD);
 		if (read_write == I2C_SMBUS_WRITE) {
 			outb_p(data->word & 0xff, SMBHSTDAT0);
 			outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
 		}
 		size = PIIX4_WORD_DATA;
 		break;
 	case I2C_SMBUS_BLOCK_DATA:
 		outb_p((addr << 1) | read_write,
 		       SMBHSTADD);
 		outb_p(command, SMBHSTCMD);
 		if (read_write == I2C_SMBUS_WRITE) {
 			len = data->block[0];
 			if (len == 0 || len > I2C_SMBUS_BLOCK_MAX)
 				return -EINVAL;
 			outb_p(len, SMBHSTDAT0);
 			i = inb_p(SMBHSTCNT);	/* Reset SMBBLKDAT */
 			for (i = 1; i <= len; i++)
 				outb_p(data->block[i], SMBBLKDAT);
 		}
 		size = PIIX4_BLOCK_DATA;
 		break;
 	default:
 		dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
 		return -EOPNOTSUPP;
 	}

 	outb_p((size & 0x1C) + (ENABLE_INT9 & 1), SMBHSTCNT);

 	status = piix4_transaction(adap);
 	if (status)
 		return status;

 	if ((read_write == I2C_SMBUS_WRITE) || (size == PIIX4_QUICK))
 		return 0;


 	switch (size) {
 	case PIIX4_BYTE:
 	case PIIX4_BYTE_DATA:
 		data->byte = inb_p(SMBHSTDAT0);
 		break;
 	case PIIX4_WORD_DATA:
 		data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
 		break;
 	case PIIX4_BLOCK_DATA:
 		data->block[0] = inb_p(SMBHSTDAT0);
 		if (data->block[0] == 0 || data->block[0] > I2C_SMBUS_BLOCK_MAX)
 			return -EPROTO;
 		i = inb_p(SMBHSTCNT);	/* Reset SMBBLKDAT */
 		for (i = 1; i <= data->block[0]; i++)
 			data->block[i] = inb_p(SMBBLKDAT);
 		break;
 	}
 	return 0;
 }

 static u32 piix4_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	= piix4_access,
 	.functionality	= piix4_func,
 };

 static const struct pci_device_id piix4_ids[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82371AB_3) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443MX_3) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_EFAR, PCI_DEVICE_ID_EFAR_SLC90E66_3) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP200_SMBUS) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP300_SMBUS) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP400_SMBUS) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_HUDSON2_SMBUS) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_KERNCZ_SMBUS) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
 		     PCI_DEVICE_ID_SERVERWORKS_OSB4) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
 		     PCI_DEVICE_ID_SERVERWORKS_CSB5) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
 		     PCI_DEVICE_ID_SERVERWORKS_CSB6) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
 		     PCI_DEVICE_ID_SERVERWORKS_HT1000SB) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
 		     PCI_DEVICE_ID_SERVERWORKS_HT1100LD) },
 	{ 0, }
 };

 MODULE_DEVICE_TABLE (pci, piix4_ids);

 static struct i2c_adapter *piix4_main_adapter;
 static struct i2c_adapter *piix4_aux_adapter;

 static int piix4_add_adapter(struct pci_dev *dev, unsigned short smba,
 			     struct i2c_adapter **padap)
 {
 	struct i2c_adapter *adap;
 	struct i2c_piix4_adapdata *adapdata;
 	int retval;

 	adap = kzalloc(sizeof(*adap), GFP_KERNEL);
 	if (adap == NULL) {
 		release_region(smba, SMBIOSIZE);
 		return -ENOMEM;
 	}

 	adap->owner = THIS_MODULE;
 	adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
 	adap->algo = &smbus_algorithm;

 	adapdata = kzalloc(sizeof(*adapdata), GFP_KERNEL);
 	if (adapdata == NULL) {
 		kfree(adap);
 		release_region(smba, SMBIOSIZE);
 		return -ENOMEM;
 	}

 	adapdata->smba = smba;

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

 	snprintf(adap->name, sizeof(adap->name),
 		"SMBus PIIX4 adapter at %04x", smba);

 	i2c_set_adapdata(adap, adapdata);

 	retval = i2c_add_adapter(adap);
 	if (retval) {
 		dev_err(&dev->dev, "Couldn't register adapter!\n");
 		kfree(adapdata);
 		kfree(adap);
 		release_region(smba, SMBIOSIZE);
 		return retval;
 	}

 	*padap = adap;
 	return 0;
 }

 static int piix4_probe(struct pci_dev *dev, const struct pci_device_id *id)
 {
 	int retval;

 	if ((dev->vendor == PCI_VENDOR_ID_ATI &&
 	     dev->device == PCI_DEVICE_ID_ATI_SBX00_SMBUS &&
 	     dev->revision >= 0x40) ||
 	    dev->vendor == PCI_VENDOR_ID_AMD)
 		/* base address location etc changed in SB800 */
 		retval = piix4_setup_sb800(dev, id, 0);
 	else
 		retval = piix4_setup(dev, id);

 	/* If no main SMBus found, give up */
 	if (retval < 0)
 		return retval;

 	/* Try to register main SMBus adapter, give up if we can't */
 	retval = piix4_add_adapter(dev, retval, &piix4_main_adapter);
 	if (retval < 0)
 		return retval;

 	/* Check for auxiliary SMBus on some AMD chipsets */
 	retval = -ENODEV;

 	if (dev->vendor == PCI_VENDOR_ID_ATI &&
 	    dev->device == PCI_DEVICE_ID_ATI_SBX00_SMBUS) {
 		if (dev->revision < 0x40) {
 			retval = piix4_setup_aux(dev, id, 0x58);
 		} else {
 			/* SB800 added aux bus too */
 			retval = piix4_setup_sb800(dev, id, 1);
 		}
 	}

 	if (dev->vendor == PCI_VENDOR_ID_AMD &&
 	    dev->device == PCI_DEVICE_ID_AMD_HUDSON2_SMBUS) {
 		retval = piix4_setup_sb800(dev, id, 1);
 	}

 	if (retval > 0) {
 		/* Try to add the aux adapter if it exists,
 		 * piix4_add_adapter will clean up if this fails */
 		piix4_add_adapter(dev, retval, &piix4_aux_adapter);
 	}

 	return 0;
 }

 static void piix4_adap_remove(struct i2c_adapter *adap)
 {
 	struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(adap);

 	if (adapdata->smba) {
 		i2c_del_adapter(adap);
 		release_region(adapdata->smba, SMBIOSIZE);
 		kfree(adapdata);
 		kfree(adap);
 	}
 }

 static void piix4_remove(struct pci_dev *dev)
 {
 	if (piix4_main_adapter) {
 		piix4_adap_remove(piix4_main_adapter);
 		piix4_main_adapter = NULL;
 	}

 	if (piix4_aux_adapter) {
 		piix4_adap_remove(piix4_aux_adapter);
 		piix4_aux_adapter = NULL;
 	}
 }

 static struct pci_driver piix4_driver = {
 	.name		= "piix4_smbus",
 	.id_table	= piix4_ids,
 	.probe		= piix4_probe,
 	.remove		= piix4_remove,
 };

 module_pci_driver(piix4_driver);

 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
 		"Philip Edelbrock <phil@netroedge.com>");
 MODULE_DESCRIPTION("PIIX4 SMBus driver");
 MODULE_LICENSE("GPL");
	/*
	Copyright (c) 1998 - 2002 Frodo Looijaard <frodol@dds.nl> and
	Philip Edelbrock <phil@netroedge.com>

	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.
	*/

	/*
	Supports:
	Intel PIIX4, 440MX
	Serverworks OSB4, CSB5, CSB6, HT-1000, HT-1100
	ATI IXP200, IXP300, IXP400, SB600, SB700/SP5100, SB800
	AMD Hudson-2, ML, CZ
	SMSC Victory66

	Note: we assume there can only be one device, with one or more
	SMBus interfaces.
	*/

	#include <linux/module.h>
	#include <linux/moduleparam.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/slab.h>
	#include <linux/dmi.h>
	#include <linux/acpi.h>
	#include <linux/io.h>


	/* PIIX4 SMBus address offsets */
	#define SMBHSTSTS (0 + piix4_smba)
	#define SMBHSLVSTS (1 + piix4_smba)
	#define SMBHSTCNT (2 + piix4_smba)
	#define SMBHSTCMD (3 + piix4_smba)
	#define SMBHSTADD (4 + piix4_smba)
	#define SMBHSTDAT0 (5 + piix4_smba)
	#define SMBHSTDAT1 (6 + piix4_smba)
	#define SMBBLKDAT (7 + piix4_smba)
	#define SMBSLVCNT (8 + piix4_smba)
	#define SMBSHDWCMD (9 + piix4_smba)
	#define SMBSLVEVT (0xA + piix4_smba)
	#define SMBSLVDAT (0xC + piix4_smba)

	/* count for request_region */
	#define SMBIOSIZE 8

	/* PCI Address Constants */
	#define SMBBA 0x090
	#define SMBHSTCFG 0x0D2
	#define SMBSLVC 0x0D3
	#define SMBSHDW1 0x0D4
	#define SMBSHDW2 0x0D5
	#define SMBREV 0x0D6

	/* Other settings */
	#define MAX_TIMEOUT 500
	#define ENABLE_INT9 0

	/* PIIX4 constants */
	#define PIIX4_QUICK 0x00
	#define PIIX4_BYTE 0x04
	#define PIIX4_BYTE_DATA 0x08
	#define PIIX4_WORD_DATA 0x0C
	#define PIIX4_BLOCK_DATA 0x14

	/* insmod parameters */

	/* If force is set to anything different from 0, we forcibly enable the
	PIIX4. DANGEROUS! */
	static int force;
	module_param (force, int, 0);
	MODULE_PARM_DESC(force, "Forcibly enable the PIIX4. DANGEROUS!");

	/* If force_addr is set to anything different from 0, we forcibly enable
	the PIIX4 at the given address. VERY DANGEROUS! */
	static int force_addr;
	module_param (force_addr, int, 0);
	MODULE_PARM_DESC(force_addr,
	"Forcibly enable the PIIX4 at the given address. "
	"EXTREMELY DANGEROUS!");

	static int srvrworks_csb5_delay;
	static struct pci_driver piix4_driver;

	static const struct dmi_system_id piix4_dmi_blacklist[] = {
	{
	.ident = "Sapphire AM2RD790",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "SAPPHIRE Inc."),
	DMI_MATCH(DMI_BOARD_NAME, "PC-AM2RD790"),
	},
	},
	{
	.ident = "DFI Lanparty UT 790FX",
	.matches = {
	DMI_MATCH(DMI_BOARD_VENDOR, "DFI Inc."),
	DMI_MATCH(DMI_BOARD_NAME, "LP UT 790FX"),
	},
	},
	{ }
	};

	/* The IBM entry is in a separate table because we only check it
	on Intel-based systems */
	static const struct dmi_system_id piix4_dmi_ibm[] = {
	{
	.ident = "IBM",
	.matches = { DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
	},
	{ },
	};

	struct i2c_piix4_adapdata {
	unsigned short smba;
	};

	static int piix4_setup(struct pci_dev *PIIX4_dev,
	const struct pci_device_id *id)
	{
	unsigned char temp;
	unsigned short piix4_smba;

	if ((PIIX4_dev->vendor == PCI_VENDOR_ID_SERVERWORKS) &&
	(PIIX4_dev->device == PCI_DEVICE_ID_SERVERWORKS_CSB5))
	srvrworks_csb5_delay = 1;

	/* On some motherboards, it was reported that accessing the SMBus
	caused severe hardware problems */
	if (dmi_check_system(piix4_dmi_blacklist)) {
	dev_err(&PIIX4_dev->dev,
	"Accessing the SMBus on this system is unsafe!\n");
	return -EPERM;
	}

	/* Don't access SMBus on IBM systems which get corrupted eeproms */
	if (dmi_check_system(piix4_dmi_ibm) &&
	PIIX4_dev->vendor == PCI_VENDOR_ID_INTEL) {
	dev_err(&PIIX4_dev->dev, "IBM system detected; this module "
	"may corrupt your serial eeprom! Refusing to load "
	"module!\n");
	return -EPERM;
	}

	/* Determine the address of the SMBus areas */
	if (force_addr) {
	piix4_smba = force_addr & 0xfff0;
	force = 0;
	} else {
	pci_read_config_word(PIIX4_dev, SMBBA, &piix4_smba);
	piix4_smba &= 0xfff0;
	if(piix4_smba == 0) {
	dev_err(&PIIX4_dev->dev, "SMBus base address "
	"uninitialized - upgrade BIOS or use "
	"force_addr=0xaddr\n");
	return -ENODEV;
	}
	}

	if (acpi_check_region(piix4_smba, SMBIOSIZE, piix4_driver.name))
	return -ENODEV;

	if (!request_region(piix4_smba, SMBIOSIZE, piix4_driver.name)) {
	dev_err(&PIIX4_dev->dev, "SMBus region 0x%x already in use!\n",
	piix4_smba);
	return -EBUSY;
	}

	pci_read_config_byte(PIIX4_dev, SMBHSTCFG, &temp);

	/* If force_addr is set, we program the new address here. Just to make
	sure, we disable the PIIX4 first. */
	if (force_addr) {
	pci_write_config_byte(PIIX4_dev, SMBHSTCFG, temp & 0xfe);
	pci_write_config_word(PIIX4_dev, SMBBA, piix4_smba);
	pci_write_config_byte(PIIX4_dev, SMBHSTCFG, temp \| 0x01);
	dev_info(&PIIX4_dev->dev, "WARNING: SMBus interface set to "
	"new address %04x!\n", piix4_smba);
	} else if ((temp & 1) == 0) {
	if (force) {
	/* This should never need to be done, but has been
	* noted that many Dell machines have the SMBus
	* interface on the PIIX4 disabled!? NOTE: This assumes
	* I/O space and other allocations WERE done by the
	* Bios! Don't complain if your hardware does weird
	* things after enabling this. :') Check for Bios
	* updates before resorting to this.
	*/
	pci_write_config_byte(PIIX4_dev, SMBHSTCFG,
	temp \| 1);
	dev_notice(&PIIX4_dev->dev,
	"WARNING: SMBus interface has been FORCEFULLY ENABLED!\n");
	} else {
	dev_err(&PIIX4_dev->dev,
	"SMBus Host Controller not enabled!\n");
	release_region(piix4_smba, SMBIOSIZE);
	return -ENODEV;
	}
	}

	if (((temp & 0x0E) == 8) \|\| ((temp & 0x0E) == 2))
	dev_dbg(&PIIX4_dev->dev, "Using IRQ for SMBus\n");
	else if ((temp & 0x0E) == 0)
	dev_dbg(&PIIX4_dev->dev, "Using SMI# for SMBus\n");
	else
	dev_err(&PIIX4_dev->dev, "Illegal Interrupt configuration "
	"(or code out of date)!\n");

	pci_read_config_byte(PIIX4_dev, SMBREV, &temp);
	dev_info(&PIIX4_dev->dev,
	"SMBus Host Controller at 0x%x, revision %d\n",
	piix4_smba, temp);

	return piix4_smba;
	}

	static int piix4_setup_sb800(struct pci_dev *PIIX4_dev,
	const struct pci_device_id *id, u8 aux)
	{
	unsigned short piix4_smba;
	unsigned short smba_idx = 0xcd6;
	u8 smba_en_lo, smba_en_hi, smb_en, smb_en_status;
	u8 i2ccfg, i2ccfg_offset = 0x10;

	/* SB800 and later SMBus does not support forcing address */
	if (force \|\| force_addr) {
	dev_err(&PIIX4_dev->dev, "SMBus does not support "
	"forcing address!\n");
	return -EINVAL;
	}

	/* Determine the address of the SMBus areas */
	if ((PIIX4_dev->vendor == PCI_VENDOR_ID_AMD &&
	PIIX4_dev->device == PCI_DEVICE_ID_AMD_HUDSON2_SMBUS &&
	PIIX4_dev->revision >= 0x41) \|\|
	(PIIX4_dev->vendor == PCI_VENDOR_ID_AMD &&
	PIIX4_dev->device == PCI_DEVICE_ID_AMD_KERNCZ_SMBUS &&
	PIIX4_dev->revision >= 0x49))
	smb_en = 0x00;
	else
	smb_en = (aux) ? 0x28 : 0x2c;

	if (!request_region(smba_idx, 2, "smba_idx")) {
	dev_err(&PIIX4_dev->dev, "SMBus base address index region "
	"0x%x already in use!\n", smba_idx);
	return -EBUSY;
	}
	outb_p(smb_en, smba_idx);
	smba_en_lo = inb_p(smba_idx + 1);
	outb_p(smb_en + 1, smba_idx);
	smba_en_hi = inb_p(smba_idx + 1);
	release_region(smba_idx, 2);

	if (!smb_en) {
	smb_en_status = smba_en_lo & 0x10;
	piix4_smba = smba_en_hi << 8;
	if (aux)
	piix4_smba \|= 0x20;
	} else {
	smb_en_status = smba_en_lo & 0x01;
	piix4_smba = ((smba_en_hi << 8) \| smba_en_lo) & 0xffe0;
	}

	if (!smb_en_status) {
	dev_err(&PIIX4_dev->dev,
	"SMBus Host Controller not enabled!\n");
	return -ENODEV;
	}

	if (acpi_check_region(piix4_smba, SMBIOSIZE, piix4_driver.name))
	return -ENODEV;

	if (!request_region(piix4_smba, SMBIOSIZE, piix4_driver.name)) {
	dev_err(&PIIX4_dev->dev, "SMBus region 0x%x already in use!\n",
	piix4_smba);
	return -EBUSY;
	}

	/* Aux SMBus does not support IRQ information */
	if (aux) {
	dev_info(&PIIX4_dev->dev,
	"Auxiliary SMBus Host Controller at 0x%x\n",
	piix4_smba);
	return piix4_smba;
	}

	/* Request the SMBus I2C bus config region */
	if (!request_region(piix4_smba + i2ccfg_offset, 1, "i2ccfg")) {
	dev_err(&PIIX4_dev->dev, "SMBus I2C bus config region "
	"0x%x already in use!\n", piix4_smba + i2ccfg_offset);
	release_region(piix4_smba, SMBIOSIZE);
	return -EBUSY;
	}
	i2ccfg = inb_p(piix4_smba + i2ccfg_offset);
	release_region(piix4_smba + i2ccfg_offset, 1);

	if (i2ccfg & 1)
	dev_dbg(&PIIX4_dev->dev, "Using IRQ for SMBus\n");
	else
	dev_dbg(&PIIX4_dev->dev, "Using SMI# for SMBus\n");

	dev_info(&PIIX4_dev->dev,
	"SMBus Host Controller at 0x%x, revision %d\n",
	piix4_smba, i2ccfg >> 4);

	return piix4_smba;
	}

	static int piix4_setup_aux(struct pci_dev *PIIX4_dev,
	const struct pci_device_id *id,
	unsigned short base_reg_addr)
	{
	/* Set up auxiliary SMBus controllers found on some
	* AMD chipsets e.g. SP5100 (SB700 derivative) */

	unsigned short piix4_smba;

	/* Read address of auxiliary SMBus controller */
	pci_read_config_word(PIIX4_dev, base_reg_addr, &piix4_smba);
	if ((piix4_smba & 1) == 0) {
	dev_dbg(&PIIX4_dev->dev,
	"Auxiliary SMBus controller not enabled\n");
	return -ENODEV;
	}

	piix4_smba &= 0xfff0;
	if (piix4_smba == 0) {
	dev_dbg(&PIIX4_dev->dev,
	"Auxiliary SMBus base address uninitialized\n");
	return -ENODEV;
	}

	if (acpi_check_region(piix4_smba, SMBIOSIZE, piix4_driver.name))
	return -ENODEV;

	if (!request_region(piix4_smba, SMBIOSIZE, piix4_driver.name)) {
	dev_err(&PIIX4_dev->dev, "Auxiliary SMBus region 0x%x "
	"already in use!\n", piix4_smba);
	return -EBUSY;
	}

	dev_info(&PIIX4_dev->dev,
	"Auxiliary SMBus Host Controller at 0x%x\n",
	piix4_smba);

	return piix4_smba;
	}

	static int piix4_transaction(struct i2c_adapter *piix4_adapter)
	{
	struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(piix4_adapter);
	unsigned short piix4_smba = adapdata->smba;
	int temp;
	int result = 0;
	int timeout = 0;

	dev_dbg(&piix4_adapter->dev, "Transaction (pre): CNT=%02x, CMD=%02x, "
	"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTCNT),
	inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
	inb_p(SMBHSTDAT1));

	/* Make sure the SMBus host is ready to start transmitting */
	if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
	dev_dbg(&piix4_adapter->dev, "SMBus busy (%02x). "
	"Resetting...\n", temp);
	outb_p(temp, SMBHSTSTS);
	if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
	dev_err(&piix4_adapter->dev, "Failed! (%02x)\n", temp);
	return -EBUSY;
	} else {
	dev_dbg(&piix4_adapter->dev, "Successful!\n");
	}
	}

	/* start the transaction by setting bit 6 */
	outb_p(inb(SMBHSTCNT) \| 0x040, SMBHSTCNT);

	/* We will always wait for a fraction of a second! (See PIIX4 docs errata) */
	if (srvrworks_csb5_delay) /* Extra delay for SERVERWORKS_CSB5 */
	msleep(2);
	else
	msleep(1);

	while ((++timeout < MAX_TIMEOUT) &&
	((temp = inb_p(SMBHSTSTS)) & 0x01))
	msleep(1);

	/* If the SMBus is still busy, we give up */
	if (timeout == MAX_TIMEOUT) {
	dev_err(&piix4_adapter->dev, "SMBus Timeout!\n");
	result = -ETIMEDOUT;
	}

	if (temp & 0x10) {
	result = -EIO;
	dev_err(&piix4_adapter->dev, "Error: Failed bus transaction\n");
	}

	if (temp & 0x08) {
	result = -EIO;
	dev_dbg(&piix4_adapter->dev, "Bus collision! SMBus may be "
	"locked until next hard reset. (sorry!)\n");
	/* Clock stops and slave is stuck in mid-transmission */
	}

	if (temp & 0x04) {
	result = -ENXIO;
	dev_dbg(&piix4_adapter->dev, "Error: no response!\n");
	}

	if (inb_p(SMBHSTSTS) != 0x00)
	outb_p(inb(SMBHSTSTS), SMBHSTSTS);

	if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
	dev_err(&piix4_adapter->dev, "Failed reset at end of "
	"transaction (%02x)\n", temp);
	}
	dev_dbg(&piix4_adapter->dev, "Transaction (post): CNT=%02x, CMD=%02x, "
	"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTCNT),
	inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
	inb_p(SMBHSTDAT1));
	return result;
	}

	/* Return negative errno on error. */
	static s32 piix4_access(struct i2c_adapter * adap, u16 addr,
	unsigned short flags, char read_write,
	u8 command, int size, union i2c_smbus_data * data)
	{
	struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(adap);
	unsigned short piix4_smba = adapdata->smba;
	int i, len;
	int status;

	switch (size) {
	case I2C_SMBUS_QUICK:
	outb_p((addr << 1) \| read_write,
	SMBHSTADD);
	size = PIIX4_QUICK;
	break;
	case I2C_SMBUS_BYTE:
	outb_p((addr << 1) \| read_write,
	SMBHSTADD);
	if (read_write == I2C_SMBUS_WRITE)
	outb_p(command, SMBHSTCMD);
	size = PIIX4_BYTE;
	break;
	case I2C_SMBUS_BYTE_DATA:
	outb_p((addr << 1) \| read_write,
	SMBHSTADD);
	outb_p(command, SMBHSTCMD);
	if (read_write == I2C_SMBUS_WRITE)
	outb_p(data->byte, SMBHSTDAT0);
	size = PIIX4_BYTE_DATA;
	break;
	case I2C_SMBUS_WORD_DATA:
	outb_p((addr << 1) \| read_write,
	SMBHSTADD);
	outb_p(command, SMBHSTCMD);
	if (read_write == I2C_SMBUS_WRITE) {
	outb_p(data->word & 0xff, SMBHSTDAT0);
	outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
	}
	size = PIIX4_WORD_DATA;
	break;
	case I2C_SMBUS_BLOCK_DATA:
	outb_p((addr << 1) \| read_write,
	SMBHSTADD);
	outb_p(command, SMBHSTCMD);
	if (read_write == I2C_SMBUS_WRITE) {
	len = data->block[0];
	if (len == 0 \|\| len > I2C_SMBUS_BLOCK_MAX)
	return -EINVAL;
	outb_p(len, SMBHSTDAT0);
	i = inb_p(SMBHSTCNT); /* Reset SMBBLKDAT */
	for (i = 1; i <= len; i++)
	outb_p(data->block[i], SMBBLKDAT);
	}
	size = PIIX4_BLOCK_DATA;
	break;
	default:
	dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
	return -EOPNOTSUPP;
	}

	outb_p((size & 0x1C) + (ENABLE_INT9 & 1), SMBHSTCNT);

	status = piix4_transaction(adap);
	if (status)
	return status;

	if ((read_write == I2C_SMBUS_WRITE) \|\| (size == PIIX4_QUICK))
	return 0;


	switch (size) {
	case PIIX4_BYTE:
	case PIIX4_BYTE_DATA:
	data->byte = inb_p(SMBHSTDAT0);
	break;
	case PIIX4_WORD_DATA:
	data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
	break;
	case PIIX4_BLOCK_DATA:
	data->block[0] = inb_p(SMBHSTDAT0);
	if (data->block[0] == 0 \|\| data->block[0] > I2C_SMBUS_BLOCK_MAX)
	return -EPROTO;
	i = inb_p(SMBHSTCNT); /* Reset SMBBLKDAT */
	for (i = 1; i <= data->block[0]; i++)
	data->block[i] = inb_p(SMBBLKDAT);
	break;
	}
	return 0;
	}

	static u32 piix4_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 = piix4_access,
	.functionality = piix4_func,
	};

	static const struct pci_device_id piix4_ids[] = {
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82371AB_3) },
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443MX_3) },
	{ PCI_DEVICE(PCI_VENDOR_ID_EFAR, PCI_DEVICE_ID_EFAR_SLC90E66_3) },
	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP200_SMBUS) },
	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP300_SMBUS) },
	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP400_SMBUS) },
	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS) },
	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_HUDSON2_SMBUS) },
	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_KERNCZ_SMBUS) },
	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
	PCI_DEVICE_ID_SERVERWORKS_OSB4) },
	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
	PCI_DEVICE_ID_SERVERWORKS_CSB5) },
	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
	PCI_DEVICE_ID_SERVERWORKS_CSB6) },
	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
	PCI_DEVICE_ID_SERVERWORKS_HT1000SB) },
	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
	PCI_DEVICE_ID_SERVERWORKS_HT1100LD) },
	{ 0, }
	};

	MODULE_DEVICE_TABLE (pci, piix4_ids);

	static struct i2c_adapter *piix4_main_adapter;
	static struct i2c_adapter *piix4_aux_adapter;

	static int piix4_add_adapter(struct pci_dev *dev, unsigned short smba,
	struct i2c_adapter **padap)
	{
	struct i2c_adapter *adap;
	struct i2c_piix4_adapdata *adapdata;
	int retval;

	adap = kzalloc(sizeof(*adap), GFP_KERNEL);
	if (adap == NULL) {
	release_region(smba, SMBIOSIZE);
	return -ENOMEM;
	}

	adap->owner = THIS_MODULE;
	adap->class = I2C_CLASS_HWMON \| I2C_CLASS_SPD;
	adap->algo = &smbus_algorithm;

	adapdata = kzalloc(sizeof(*adapdata), GFP_KERNEL);
	if (adapdata == NULL) {
	kfree(adap);
	release_region(smba, SMBIOSIZE);
	return -ENOMEM;
	}

	adapdata->smba = smba;

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

	snprintf(adap->name, sizeof(adap->name),
	"SMBus PIIX4 adapter at %04x", smba);

	i2c_set_adapdata(adap, adapdata);

	retval = i2c_add_adapter(adap);
	if (retval) {
	dev_err(&dev->dev, "Couldn't register adapter!\n");
	kfree(adapdata);
	kfree(adap);
	release_region(smba, SMBIOSIZE);
	return retval;
	}

	*padap = adap;
	return 0;
	}

	static int piix4_probe(struct pci_dev dev, const struct pci_device_id id)
	{
	int retval;

	if ((dev->vendor == PCI_VENDOR_ID_ATI &&
	dev->device == PCI_DEVICE_ID_ATI_SBX00_SMBUS &&
	dev->revision >= 0x40) \|\|
	dev->vendor == PCI_VENDOR_ID_AMD)
	/* base address location etc changed in SB800 */
	retval = piix4_setup_sb800(dev, id, 0);
	else
	retval = piix4_setup(dev, id);

	/* If no main SMBus found, give up */
	if (retval < 0)
	return retval;

	/* Try to register main SMBus adapter, give up if we can't */
	retval = piix4_add_adapter(dev, retval, &piix4_main_adapter);
	if (retval < 0)
	return retval;

	/* Check for auxiliary SMBus on some AMD chipsets */
	retval = -ENODEV;

	if (dev->vendor == PCI_VENDOR_ID_ATI &&
	dev->device == PCI_DEVICE_ID_ATI_SBX00_SMBUS) {
	if (dev->revision < 0x40) {
	retval = piix4_setup_aux(dev, id, 0x58);
	} else {
	/* SB800 added aux bus too */
	retval = piix4_setup_sb800(dev, id, 1);
	}
	}

	if (dev->vendor == PCI_VENDOR_ID_AMD &&
	dev->device == PCI_DEVICE_ID_AMD_HUDSON2_SMBUS) {
	retval = piix4_setup_sb800(dev, id, 1);
	}

	if (retval > 0) {
	/* Try to add the aux adapter if it exists,
	* piix4_add_adapter will clean up if this fails */
	piix4_add_adapter(dev, retval, &piix4_aux_adapter);
	}

	return 0;
	}

	static void piix4_adap_remove(struct i2c_adapter *adap)
	{
	struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(adap);

	if (adapdata->smba) {
	i2c_del_adapter(adap);
	release_region(adapdata->smba, SMBIOSIZE);
	kfree(adapdata);
	kfree(adap);
	}
	}

	static void piix4_remove(struct pci_dev *dev)
	{
	if (piix4_main_adapter) {
	piix4_adap_remove(piix4_main_adapter);
	piix4_main_adapter = NULL;
	}

	if (piix4_aux_adapter) {
	piix4_adap_remove(piix4_aux_adapter);
	piix4_aux_adapter = NULL;
	}
	}

	static struct pci_driver piix4_driver = {
	.name = "piix4_smbus",
	.id_table = piix4_ids,
	.probe = piix4_probe,
	.remove = piix4_remove,
	};

	module_pci_driver(piix4_driver);

	MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
	"Philip Edelbrock <phil@netroedge.com>");
	MODULE_DESCRIPTION("PIIX4 SMBus driver");
	MODULE_LICENSE("GPL");