drivers/i2c/busses/i2c-i801.c - third_party/linux - Git at Google

 /*
     i2c-i801.c - Part of lm_sensors, Linux kernel modules for hardware
               monitoring
     Copyright (c) 1998 - 2002  Frodo Looijaard <frodol@dds.nl>,
     Philip Edelbrock <phil@netroedge.com>, and Mark D. Studebaker
     <mdsxyz123@yahoo.com>
     Copyright (C) 2007         Jean Delvare <khali@linux-fr.org>

     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.
 */

 /*
   Supports the following Intel I/O Controller Hubs (ICH):

                                   I/O                     Block   I2C
                                   region  SMBus   Block   proc.   block
   Chip name             PCI ID    size    PEC     buffer  call    read
   ----------------------------------------------------------------------
   82801AA  (ICH)        0x2413     16      no      no      no      no
   82801AB  (ICH0)       0x2423     16      no      no      no      no
   82801BA  (ICH2)       0x2443     16      no      no      no      no
   82801CA  (ICH3)       0x2483     32     soft     no      no      no
   82801DB  (ICH4)       0x24c3     32     hard     yes     no      no
   82801E   (ICH5)       0x24d3     32     hard     yes     yes     yes
   6300ESB               0x25a4     32     hard     yes     yes     yes
   82801F   (ICH6)       0x266a     32     hard     yes     yes     yes
   6310ESB/6320ESB       0x269b     32     hard     yes     yes     yes
   82801G   (ICH7)       0x27da     32     hard     yes     yes     yes
   82801H   (ICH8)       0x283e     32     hard     yes     yes     yes
   82801I   (ICH9)       0x2930     32     hard     yes     yes     yes
   Tolapai               0x5032     32     hard     yes     yes     yes
   ICH10                 0x3a30     32     hard     yes     yes     yes
   ICH10                 0x3a60     32     hard     yes     yes     yes

   Features supported by this driver:
   Software PEC                     no
   Hardware PEC                     yes
   Block buffer                     yes
   Block process call transaction   no
   I2C block read transaction       yes  (doesn't use the block buffer)

   See the file Documentation/i2c/busses/i2c-i801 for details.
 */

 /* Note: we assume there can only be one I801, with one SMBus interface */

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

 /* I801 SMBus address offsets */
 #define SMBHSTSTS	(0 + i801_smba)
 #define SMBHSTCNT	(2 + i801_smba)
 #define SMBHSTCMD	(3 + i801_smba)
 #define SMBHSTADD	(4 + i801_smba)
 #define SMBHSTDAT0	(5 + i801_smba)
 #define SMBHSTDAT1	(6 + i801_smba)
 #define SMBBLKDAT	(7 + i801_smba)
 #define SMBPEC		(8 + i801_smba)		/* ICH3 and later */
 #define SMBAUXSTS	(12 + i801_smba)	/* ICH4 and later */
 #define SMBAUXCTL	(13 + i801_smba)	/* ICH4 and later */

 /* PCI Address Constants */
 #define SMBBAR		4
 #define SMBHSTCFG	0x040

 /* Host configuration bits for SMBHSTCFG */
 #define SMBHSTCFG_HST_EN	1
 #define SMBHSTCFG_SMB_SMI_EN	2
 #define SMBHSTCFG_I2C_EN	4

 /* Auxillary control register bits, ICH4+ only */
 #define SMBAUXCTL_CRC		1
 #define SMBAUXCTL_E32B		2

 /* kill bit for SMBHSTCNT */
 #define SMBHSTCNT_KILL		2

 /* Other settings */
 #define MAX_TIMEOUT		100
 #define ENABLE_INT9		0	/* set to 0x01 to enable - untested */

 /* I801 command constants */
 #define I801_QUICK		0x00
 #define I801_BYTE		0x04
 #define I801_BYTE_DATA		0x08
 #define I801_WORD_DATA		0x0C
 #define I801_PROC_CALL		0x10	/* unimplemented */
 #define I801_BLOCK_DATA		0x14
 #define I801_I2C_BLOCK_DATA	0x18	/* ICH5 and later */
 #define I801_BLOCK_LAST		0x34
 #define I801_I2C_BLOCK_LAST	0x38	/* ICH5 and later */
 #define I801_START		0x40
 #define I801_PEC_EN		0x80	/* ICH3 and later */

 /* I801 Hosts Status register bits */
 #define SMBHSTSTS_BYTE_DONE	0x80
 #define SMBHSTSTS_INUSE_STS	0x40
 #define SMBHSTSTS_SMBALERT_STS	0x20
 #define SMBHSTSTS_FAILED	0x10
 #define SMBHSTSTS_BUS_ERR	0x08
 #define SMBHSTSTS_DEV_ERR	0x04
 #define SMBHSTSTS_INTR		0x02
 #define SMBHSTSTS_HOST_BUSY	0x01

 static unsigned long i801_smba;
 static unsigned char i801_original_hstcfg;
 static struct pci_driver i801_driver;
 static struct pci_dev *I801_dev;

 #define FEATURE_SMBUS_PEC	(1 << 0)
 #define FEATURE_BLOCK_BUFFER	(1 << 1)
 #define FEATURE_BLOCK_PROC	(1 << 2)
 #define FEATURE_I2C_BLOCK_READ	(1 << 3)
 static unsigned int i801_features;

 static int i801_transaction(int xact)
 {
 	int temp;
 	int result = 0;
 	int timeout = 0;

 	dev_dbg(&I801_dev->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 */
 	/* 0x1f = Failed, Bus_Err, Dev_Err, Intr, Host_Busy */
 	if ((temp = (0x1f & inb_p(SMBHSTSTS))) != 0x00) {
 		dev_dbg(&I801_dev->dev, "SMBus busy (%02x). Resetting...\n",
 			temp);
 		outb_p(temp, SMBHSTSTS);
 		if ((temp = (0x1f & inb_p(SMBHSTSTS))) != 0x00) {
 			dev_dbg(&I801_dev->dev, "Failed! (%02x)\n", temp);
 			return -1;
 		} else {
 			dev_dbg(&I801_dev->dev, "Successful!\n");
 		}
 	}

 	/* the current contents of SMBHSTCNT can be overwritten, since PEC,
 	 * INTREN, SMBSCMD are passed in xact */
 	outb_p(xact | I801_START, SMBHSTCNT);

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

 	/* If the SMBus is still busy, we give up */
 	if (timeout >= MAX_TIMEOUT) {
 		dev_dbg(&I801_dev->dev, "SMBus Timeout!\n");
 		result = -1;
 		/* try to stop the current command */
 		dev_dbg(&I801_dev->dev, "Terminating the current operation\n");
 		outb_p(inb_p(SMBHSTCNT) | SMBHSTCNT_KILL, SMBHSTCNT);
 		msleep(1);
 		outb_p(inb_p(SMBHSTCNT) & (~SMBHSTCNT_KILL), SMBHSTCNT);
 	}

 	if (temp & SMBHSTSTS_FAILED) {
 		result = -1;
 		dev_dbg(&I801_dev->dev, "Error: Failed bus transaction\n");
 	}

 	if (temp & SMBHSTSTS_BUS_ERR) {
 		result = -1;
 		dev_err(&I801_dev->dev, "Bus collision! SMBus may be locked "
 			"until next hard reset. (sorry!)\n");
 		/* Clock stops and slave is stuck in mid-transmission */
 	}

 	if (temp & SMBHSTSTS_DEV_ERR) {
 		result = -1;
 		dev_dbg(&I801_dev->dev, "Error: no response!\n");
 	}

 	if ((inb_p(SMBHSTSTS) & 0x1f) != 0x00)
 		outb_p(inb(SMBHSTSTS), SMBHSTSTS);

 	if ((temp = (0x1f & inb_p(SMBHSTSTS))) != 0x00) {
 		dev_dbg(&I801_dev->dev, "Failed reset at end of transaction "
 			"(%02x)\n", temp);
 	}
 	dev_dbg(&I801_dev->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;
 }

 /* wait for INTR bit as advised by Intel */
 static void i801_wait_hwpec(void)
 {
 	int timeout = 0;
 	int temp;

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

 	if (timeout >= MAX_TIMEOUT) {
 		dev_dbg(&I801_dev->dev, "PEC Timeout!\n");
 	}
 	outb_p(temp, SMBHSTSTS);
 }

 static int i801_block_transaction_by_block(union i2c_smbus_data *data,
 					   char read_write, int hwpec)
 {
 	int i, len;

 	inb_p(SMBHSTCNT); /* reset the data buffer index */

 	/* Use 32-byte buffer to process this transaction */
 	if (read_write == I2C_SMBUS_WRITE) {
 		len = data->block[0];
 		outb_p(len, SMBHSTDAT0);
 		for (i = 0; i < len; i++)
 			outb_p(data->block[i+1], SMBBLKDAT);
 	}

 	if (i801_transaction(I801_BLOCK_DATA | ENABLE_INT9 |
 			     I801_PEC_EN * hwpec))
 		return -1;

 	if (read_write == I2C_SMBUS_READ) {
 		len = inb_p(SMBHSTDAT0);
 		if (len < 1 || len > I2C_SMBUS_BLOCK_MAX)
 			return -1;

 		data->block[0] = len;
 		for (i = 0; i < len; i++)
 			data->block[i + 1] = inb_p(SMBBLKDAT);
 	}
 	return 0;
 }

 static int i801_block_transaction_byte_by_byte(union i2c_smbus_data *data,
 					       char read_write, int command,
 					       int hwpec)
 {
 	int i, len;
 	int smbcmd;
 	int temp;
 	int result = 0;
 	int timeout;
 	unsigned char errmask;

 	len = data->block[0];

 	if (read_write == I2C_SMBUS_WRITE) {
 		outb_p(len, SMBHSTDAT0);
 		outb_p(data->block[1], SMBBLKDAT);
 	}

 	for (i = 1; i <= len; i++) {
 		if (i == len && read_write == I2C_SMBUS_READ) {
 			if (command == I2C_SMBUS_I2C_BLOCK_DATA)
 				smbcmd = I801_I2C_BLOCK_LAST;
 			else
 				smbcmd = I801_BLOCK_LAST;
 		} else {
 			if (command == I2C_SMBUS_I2C_BLOCK_DATA
 			 && read_write == I2C_SMBUS_READ)
 				smbcmd = I801_I2C_BLOCK_DATA;
 			else
 				smbcmd = I801_BLOCK_DATA;
 		}
 		outb_p(smbcmd | ENABLE_INT9, SMBHSTCNT);

 		dev_dbg(&I801_dev->dev, "Block (pre %d): CNT=%02x, CMD=%02x, "
 			"ADD=%02x, DAT0=%02x, DAT1=%02x, BLKDAT=%02x\n", i,
 			inb_p(SMBHSTCNT), inb_p(SMBHSTCMD), inb_p(SMBHSTADD),
 			inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1), inb_p(SMBBLKDAT));

 		/* Make sure the SMBus host is ready to start transmitting */
 		temp = inb_p(SMBHSTSTS);
 		if (i == 1) {
 			/* Erroneous conditions before transaction:
 			 * Byte_Done, Failed, Bus_Err, Dev_Err, Intr, Host_Busy */
 			errmask = 0x9f;
 		} else {
 			/* Erroneous conditions during transaction:
 			 * Failed, Bus_Err, Dev_Err, Intr */
 			errmask = 0x1e;
 		}
 		if (temp & errmask) {
 			dev_dbg(&I801_dev->dev, "SMBus busy (%02x). "
 				"Resetting...\n", temp);
 			outb_p(temp, SMBHSTSTS);
 			if (((temp = inb_p(SMBHSTSTS)) & errmask) != 0x00) {
 				dev_err(&I801_dev->dev,
 					"Reset failed! (%02x)\n", temp);
 				return -1;
 			}
 			if (i != 1)
 				/* if die in middle of block transaction, fail */
 				return -1;
 		}

 		if (i == 1)
 			outb_p(inb(SMBHSTCNT) | I801_START, SMBHSTCNT);

 		/* We will always wait for a fraction of a second! */
 		timeout = 0;
 		do {
 			msleep(1);
 			temp = inb_p(SMBHSTSTS);
 		}
 		while ((!(temp & SMBHSTSTS_BYTE_DONE))
 		       && (timeout++ < MAX_TIMEOUT));

 		/* If the SMBus is still busy, we give up */
 		if (timeout >= MAX_TIMEOUT) {
 			/* try to stop the current command */
 			dev_dbg(&I801_dev->dev, "Terminating the current "
 						"operation\n");
 			outb_p(inb_p(SMBHSTCNT) | SMBHSTCNT_KILL, SMBHSTCNT);
 			msleep(1);
 			outb_p(inb_p(SMBHSTCNT) & (~SMBHSTCNT_KILL),
 				SMBHSTCNT);
 			result = -1;
 			dev_dbg(&I801_dev->dev, "SMBus Timeout!\n");
 		}

 		if (temp & SMBHSTSTS_FAILED) {
 			result = -1;
 			dev_dbg(&I801_dev->dev,
 				"Error: Failed bus transaction\n");
 		} else if (temp & SMBHSTSTS_BUS_ERR) {
 			result = -1;
 			dev_err(&I801_dev->dev, "Bus collision!\n");
 		} else if (temp & SMBHSTSTS_DEV_ERR) {
 			result = -1;
 			dev_dbg(&I801_dev->dev, "Error: no response!\n");
 		}

 		if (i == 1 && read_write == I2C_SMBUS_READ
 		 && command != I2C_SMBUS_I2C_BLOCK_DATA) {
 			len = inb_p(SMBHSTDAT0);
 			if (len < 1 || len > I2C_SMBUS_BLOCK_MAX)
 				return -1;
 			data->block[0] = len;
 		}

 		/* Retrieve/store value in SMBBLKDAT */
 		if (read_write == I2C_SMBUS_READ)
 			data->block[i] = inb_p(SMBBLKDAT);
 		if (read_write == I2C_SMBUS_WRITE && i+1 <= len)
 			outb_p(data->block[i+1], SMBBLKDAT);
 		if ((temp & 0x9e) != 0x00)
 			outb_p(temp, SMBHSTSTS);  /* signals SMBBLKDAT ready */

 		if ((temp = (0x1e & inb_p(SMBHSTSTS))) != 0x00) {
 			dev_dbg(&I801_dev->dev,
 				"Bad status (%02x) at end of transaction\n",
 				temp);
 		}
 		dev_dbg(&I801_dev->dev, "Block (post %d): CNT=%02x, CMD=%02x, "
 			"ADD=%02x, DAT0=%02x, DAT1=%02x, BLKDAT=%02x\n", i,
 			inb_p(SMBHSTCNT), inb_p(SMBHSTCMD), inb_p(SMBHSTADD),
 			inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1), inb_p(SMBBLKDAT));

 		if (result < 0)
 			return result;
 	}
 	return result;
 }

 static int i801_set_block_buffer_mode(void)
 {
 	outb_p(inb_p(SMBAUXCTL) | SMBAUXCTL_E32B, SMBAUXCTL);
 	if ((inb_p(SMBAUXCTL) & SMBAUXCTL_E32B) == 0)
 		return -1;
 	return 0;
 }

 /* Block transaction function */
 static int i801_block_transaction(union i2c_smbus_data *data, char read_write,
 				  int command, int hwpec)
 {
 	int result = 0;
 	unsigned char hostc;

 	if (command == I2C_SMBUS_I2C_BLOCK_DATA) {
 		if (read_write == I2C_SMBUS_WRITE) {
 			/* set I2C_EN bit in configuration register */
 			pci_read_config_byte(I801_dev, SMBHSTCFG, &hostc);
 			pci_write_config_byte(I801_dev, SMBHSTCFG,
 					      hostc | SMBHSTCFG_I2C_EN);
 		} else if (!(i801_features & FEATURE_I2C_BLOCK_READ)) {
 			dev_err(&I801_dev->dev,
 				"I2C block read is unsupported!\n");
 			return -1;
 		}
 	}

 	if (read_write == I2C_SMBUS_WRITE
 	 || command == I2C_SMBUS_I2C_BLOCK_DATA) {
 		if (data->block[0] < 1)
 			data->block[0] = 1;
 		if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
 			data->block[0] = I2C_SMBUS_BLOCK_MAX;
 	} else {
 		data->block[0] = 32;	/* max for SMBus block reads */
 	}

 	if ((i801_features & FEATURE_BLOCK_BUFFER)
 	 && !(command == I2C_SMBUS_I2C_BLOCK_DATA
 	      && read_write == I2C_SMBUS_READ)
 	 && i801_set_block_buffer_mode() == 0)
 		result = i801_block_transaction_by_block(data, read_write,
 							 hwpec);
 	else
 		result = i801_block_transaction_byte_by_byte(data, read_write,
 							     command, hwpec);

 	if (result == 0 && hwpec)
 		i801_wait_hwpec();

 	if (command == I2C_SMBUS_I2C_BLOCK_DATA
 	 && read_write == I2C_SMBUS_WRITE) {
 		/* restore saved configuration register value */
 		pci_write_config_byte(I801_dev, SMBHSTCFG, hostc);
 	}
 	return result;
 }

 /* Return -1 on error. */
 static s32 i801_access(struct i2c_adapter * adap, u16 addr,
 		       unsigned short flags, char read_write, u8 command,
 		       int size, union i2c_smbus_data * data)
 {
 	int hwpec;
 	int block = 0;
 	int ret, xact = 0;

 	hwpec = (i801_features & FEATURE_SMBUS_PEC) && (flags & I2C_CLIENT_PEC)
 		&& size != I2C_SMBUS_QUICK
 		&& size != I2C_SMBUS_I2C_BLOCK_DATA;

 	switch (size) {
 	case I2C_SMBUS_QUICK:
 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 		       SMBHSTADD);
 		xact = I801_QUICK;
 		break;
 	case I2C_SMBUS_BYTE:
 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 		       SMBHSTADD);
 		if (read_write == I2C_SMBUS_WRITE)
 			outb_p(command, SMBHSTCMD);
 		xact = I801_BYTE;
 		break;
 	case I2C_SMBUS_BYTE_DATA:
 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 		       SMBHSTADD);
 		outb_p(command, SMBHSTCMD);
 		if (read_write == I2C_SMBUS_WRITE)
 			outb_p(data->byte, SMBHSTDAT0);
 		xact = I801_BYTE_DATA;
 		break;
 	case I2C_SMBUS_WORD_DATA:
 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 		       SMBHSTADD);
 		outb_p(command, SMBHSTCMD);
 		if (read_write == I2C_SMBUS_WRITE) {
 			outb_p(data->word & 0xff, SMBHSTDAT0);
 			outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
 		}
 		xact = I801_WORD_DATA;
 		break;
 	case I2C_SMBUS_BLOCK_DATA:
 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 		       SMBHSTADD);
 		outb_p(command, SMBHSTCMD);
 		block = 1;
 		break;
 	case I2C_SMBUS_I2C_BLOCK_DATA:
 		/* NB: page 240 of ICH5 datasheet shows that the R/#W
 		 * bit should be cleared here, even when reading */
 		outb_p((addr & 0x7f) << 1, SMBHSTADD);
 		if (read_write == I2C_SMBUS_READ) {
 			/* NB: page 240 of ICH5 datasheet also shows
 			 * that DATA1 is the cmd field when reading */
 			outb_p(command, SMBHSTDAT1);
 		} else
 			outb_p(command, SMBHSTCMD);
 		block = 1;
 		break;
 	case I2C_SMBUS_PROC_CALL:
 	default:
 		dev_err(&I801_dev->dev, "Unsupported transaction %d\n", size);
 		return -1;
 	}

 	if (hwpec)	/* enable/disable hardware PEC */
 		outb_p(inb_p(SMBAUXCTL) | SMBAUXCTL_CRC, SMBAUXCTL);
 	else
 		outb_p(inb_p(SMBAUXCTL) & (~SMBAUXCTL_CRC), SMBAUXCTL);

 	if(block)
 		ret = i801_block_transaction(data, read_write, size, hwpec);
 	else
 		ret = i801_transaction(xact | ENABLE_INT9);

 	/* Some BIOSes don't like it when PEC is enabled at reboot or resume
 	   time, so we forcibly disable it after every transaction. Turn off
 	   E32B for the same reason. */
 	if (hwpec || block)
 		outb_p(inb_p(SMBAUXCTL) & ~(SMBAUXCTL_CRC | SMBAUXCTL_E32B),
 		       SMBAUXCTL);

 	if(block)
 		return ret;
 	if(ret)
 		return -1;
 	if ((read_write == I2C_SMBUS_WRITE) || (xact == I801_QUICK))
 		return 0;

 	switch (xact & 0x7f) {
 	case I801_BYTE:	/* Result put in SMBHSTDAT0 */
 	case I801_BYTE_DATA:
 		data->byte = inb_p(SMBHSTDAT0);
 		break;
 	case I801_WORD_DATA:
 		data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
 		break;
 	}
 	return 0;
 }


 static u32 i801_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 | I2C_FUNC_SMBUS_WRITE_I2C_BLOCK |
 	       ((i801_features & FEATURE_SMBUS_PEC) ? I2C_FUNC_SMBUS_PEC : 0) |
 	       ((i801_features & FEATURE_I2C_BLOCK_READ) ?
 		I2C_FUNC_SMBUS_READ_I2C_BLOCK : 0);
 }

 static const struct i2c_algorithm smbus_algorithm = {
 	.smbus_xfer	= i801_access,
 	.functionality	= i801_func,
 };

 static struct i2c_adapter i801_adapter = {
 	.owner		= THIS_MODULE,
 	.id		= I2C_HW_SMBUS_I801,
 	.class		= I2C_CLASS_HWMON,
 	.algo		= &smbus_algorithm,
 };

 static struct pci_device_id i801_ids[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801AA_3) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801AB_3) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801BA_2) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801CA_3) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801DB_3) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801EB_3) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ESB_4) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH6_16) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH7_17) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ESB2_17) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH8_5) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH9_6) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_TOLAPAI_1) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH10_4) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH10_5) },
 	{ 0, }
 };

 MODULE_DEVICE_TABLE (pci, i801_ids);

 static int __devinit i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
 {
 	unsigned char temp;
 	int err;

 	I801_dev = dev;
 	i801_features = 0;
 	switch (dev->device) {
 	case PCI_DEVICE_ID_INTEL_82801EB_3:
 	case PCI_DEVICE_ID_INTEL_ESB_4:
 	case PCI_DEVICE_ID_INTEL_ICH6_16:
 	case PCI_DEVICE_ID_INTEL_ICH7_17:
 	case PCI_DEVICE_ID_INTEL_ESB2_17:
 	case PCI_DEVICE_ID_INTEL_ICH8_5:
 	case PCI_DEVICE_ID_INTEL_ICH9_6:
 	case PCI_DEVICE_ID_INTEL_TOLAPAI_1:
 	case PCI_DEVICE_ID_INTEL_ICH10_4:
 	case PCI_DEVICE_ID_INTEL_ICH10_5:
 		i801_features |= FEATURE_I2C_BLOCK_READ;
 		/* fall through */
 	case PCI_DEVICE_ID_INTEL_82801DB_3:
 		i801_features |= FEATURE_SMBUS_PEC;
 		i801_features |= FEATURE_BLOCK_BUFFER;
 		break;
 	}

 	err = pci_enable_device(dev);
 	if (err) {
 		dev_err(&dev->dev, "Failed to enable SMBus PCI device (%d)\n",
 			err);
 		goto exit;
 	}

 	/* Determine the address of the SMBus area */
 	i801_smba = pci_resource_start(dev, SMBBAR);
 	if (!i801_smba) {
 		dev_err(&dev->dev, "SMBus base address uninitialized, "
 			"upgrade BIOS\n");
 		err = -ENODEV;
 		goto exit;
 	}

 	err = pci_request_region(dev, SMBBAR, i801_driver.name);
 	if (err) {
 		dev_err(&dev->dev, "Failed to request SMBus region "
 			"0x%lx-0x%Lx\n", i801_smba,
 			(unsigned long long)pci_resource_end(dev, SMBBAR));
 		goto exit;
 	}

 	pci_read_config_byte(I801_dev, SMBHSTCFG, &temp);
 	i801_original_hstcfg = temp;
 	temp &= ~SMBHSTCFG_I2C_EN;	/* SMBus timing */
 	if (!(temp & SMBHSTCFG_HST_EN)) {
 		dev_info(&dev->dev, "Enabling SMBus device\n");
 		temp |= SMBHSTCFG_HST_EN;
 	}
 	pci_write_config_byte(I801_dev, SMBHSTCFG, temp);

 	if (temp & SMBHSTCFG_SMB_SMI_EN)
 		dev_dbg(&dev->dev, "SMBus using interrupt SMI#\n");
 	else
 		dev_dbg(&dev->dev, "SMBus using PCI Interrupt\n");

 	/* Clear special mode bits */
 	if (i801_features & (FEATURE_SMBUS_PEC | FEATURE_BLOCK_BUFFER))
 		outb_p(inb_p(SMBAUXCTL) & ~(SMBAUXCTL_CRC | SMBAUXCTL_E32B),
 		       SMBAUXCTL);

 	/* set up the sysfs linkage to our parent device */
 	i801_adapter.dev.parent = &dev->dev;

 	snprintf(i801_adapter.name, sizeof(i801_adapter.name),
 		"SMBus I801 adapter at %04lx", i801_smba);
 	err = i2c_add_adapter(&i801_adapter);
 	if (err) {
 		dev_err(&dev->dev, "Failed to add SMBus adapter\n");
 		goto exit_release;
 	}
 	return 0;

 exit_release:
 	pci_release_region(dev, SMBBAR);
 exit:
 	return err;
 }

 static void __devexit i801_remove(struct pci_dev *dev)
 {
 	i2c_del_adapter(&i801_adapter);
 	pci_write_config_byte(I801_dev, SMBHSTCFG, i801_original_hstcfg);
 	pci_release_region(dev, SMBBAR);
 	/*
 	 * do not call pci_disable_device(dev) since it can cause hard hangs on
 	 * some systems during power-off (eg. Fujitsu-Siemens Lifebook E8010)
 	 */
 }

 #ifdef CONFIG_PM
 static int i801_suspend(struct pci_dev *dev, pm_message_t mesg)
 {
 	pci_save_state(dev);
 	pci_write_config_byte(dev, SMBHSTCFG, i801_original_hstcfg);
 	pci_set_power_state(dev, pci_choose_state(dev, mesg));
 	return 0;
 }

 static int i801_resume(struct pci_dev *dev)
 {
 	pci_set_power_state(dev, PCI_D0);
 	pci_restore_state(dev);
 	return pci_enable_device(dev);
 }
 #else
 #define i801_suspend NULL
 #define i801_resume NULL
 #endif

 static struct pci_driver i801_driver = {
 	.name		= "i801_smbus",
 	.id_table	= i801_ids,
 	.probe		= i801_probe,
 	.remove		= __devexit_p(i801_remove),
 	.suspend	= i801_suspend,
 	.resume		= i801_resume,
 };

 static int __init i2c_i801_init(void)
 {
 	return pci_register_driver(&i801_driver);
 }

 static void __exit i2c_i801_exit(void)
 {
 	pci_unregister_driver(&i801_driver);
 }

 MODULE_AUTHOR("Mark D. Studebaker <mdsxyz123@yahoo.com>, "
 	      "Jean Delvare <khali@linux-fr.org>");
 MODULE_DESCRIPTION("I801 SMBus driver");
 MODULE_LICENSE("GPL");

 module_init(i2c_i801_init);
 module_exit(i2c_i801_exit);
	/*
	i2c-i801.c - Part of lm_sensors, Linux kernel modules for hardware
	monitoring
	Copyright (c) 1998 - 2002 Frodo Looijaard <frodol@dds.nl>,
	Philip Edelbrock <phil@netroedge.com>, and Mark D. Studebaker
	<mdsxyz123@yahoo.com>
	Copyright (C) 2007 Jean Delvare <khali@linux-fr.org>

	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.
	*/

	/*
	Supports the following Intel I/O Controller Hubs (ICH):

	I/O Block I2C
	region SMBus Block proc. block
	Chip name PCI ID size PEC buffer call read
	----------------------------------------------------------------------
	82801AA (ICH) 0x2413 16 no no no no
	82801AB (ICH0) 0x2423 16 no no no no
	82801BA (ICH2) 0x2443 16 no no no no
	82801CA (ICH3) 0x2483 32 soft no no no
	82801DB (ICH4) 0x24c3 32 hard yes no no
	82801E (ICH5) 0x24d3 32 hard yes yes yes
	6300ESB 0x25a4 32 hard yes yes yes
	82801F (ICH6) 0x266a 32 hard yes yes yes
	6310ESB/6320ESB 0x269b 32 hard yes yes yes
	82801G (ICH7) 0x27da 32 hard yes yes yes
	82801H (ICH8) 0x283e 32 hard yes yes yes
	82801I (ICH9) 0x2930 32 hard yes yes yes
	Tolapai 0x5032 32 hard yes yes yes
	ICH10 0x3a30 32 hard yes yes yes
	ICH10 0x3a60 32 hard yes yes yes

	Features supported by this driver:
	Software PEC no
	Hardware PEC yes
	Block buffer yes
	Block process call transaction no
	I2C block read transaction yes (doesn't use the block buffer)

	See the file Documentation/i2c/busses/i2c-i801 for details.
	*/

	/* Note: we assume there can only be one I801, with one SMBus interface */

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

	/* I801 SMBus address offsets */
	#define SMBHSTSTS (0 + i801_smba)
	#define SMBHSTCNT (2 + i801_smba)
	#define SMBHSTCMD (3 + i801_smba)
	#define SMBHSTADD (4 + i801_smba)
	#define SMBHSTDAT0 (5 + i801_smba)
	#define SMBHSTDAT1 (6 + i801_smba)
	#define SMBBLKDAT (7 + i801_smba)
	#define SMBPEC (8 + i801_smba) /* ICH3 and later */
	#define SMBAUXSTS (12 + i801_smba) /* ICH4 and later */
	#define SMBAUXCTL (13 + i801_smba) /* ICH4 and later */

	/* PCI Address Constants */
	#define SMBBAR 4
	#define SMBHSTCFG 0x040

	/* Host configuration bits for SMBHSTCFG */
	#define SMBHSTCFG_HST_EN 1
	#define SMBHSTCFG_SMB_SMI_EN 2
	#define SMBHSTCFG_I2C_EN 4

	/* Auxillary control register bits, ICH4+ only */
	#define SMBAUXCTL_CRC 1
	#define SMBAUXCTL_E32B 2

	/* kill bit for SMBHSTCNT */
	#define SMBHSTCNT_KILL 2

	/* Other settings */
	#define MAX_TIMEOUT 100
	#define ENABLE_INT9 0 /* set to 0x01 to enable - untested */

	/* I801 command constants */
	#define I801_QUICK 0x00
	#define I801_BYTE 0x04
	#define I801_BYTE_DATA 0x08
	#define I801_WORD_DATA 0x0C
	#define I801_PROC_CALL 0x10 /* unimplemented */
	#define I801_BLOCK_DATA 0x14
	#define I801_I2C_BLOCK_DATA 0x18 /* ICH5 and later */
	#define I801_BLOCK_LAST 0x34
	#define I801_I2C_BLOCK_LAST 0x38 /* ICH5 and later */
	#define I801_START 0x40
	#define I801_PEC_EN 0x80 /* ICH3 and later */

	/* I801 Hosts Status register bits */
	#define SMBHSTSTS_BYTE_DONE 0x80
	#define SMBHSTSTS_INUSE_STS 0x40
	#define SMBHSTSTS_SMBALERT_STS 0x20
	#define SMBHSTSTS_FAILED 0x10
	#define SMBHSTSTS_BUS_ERR 0x08
	#define SMBHSTSTS_DEV_ERR 0x04
	#define SMBHSTSTS_INTR 0x02
	#define SMBHSTSTS_HOST_BUSY 0x01

	static unsigned long i801_smba;
	static unsigned char i801_original_hstcfg;
	static struct pci_driver i801_driver;
	static struct pci_dev *I801_dev;

	#define FEATURE_SMBUS_PEC (1 << 0)
	#define FEATURE_BLOCK_BUFFER (1 << 1)
	#define FEATURE_BLOCK_PROC (1 << 2)
	#define FEATURE_I2C_BLOCK_READ (1 << 3)
	static unsigned int i801_features;

	static int i801_transaction(int xact)
	{
	int temp;
	int result = 0;
	int timeout = 0;

	dev_dbg(&I801_dev->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 */
	/* 0x1f = Failed, Bus_Err, Dev_Err, Intr, Host_Busy */
	if ((temp = (0x1f & inb_p(SMBHSTSTS))) != 0x00) {
	dev_dbg(&I801_dev->dev, "SMBus busy (%02x). Resetting...\n",
	temp);
	outb_p(temp, SMBHSTSTS);
	if ((temp = (0x1f & inb_p(SMBHSTSTS))) != 0x00) {
	dev_dbg(&I801_dev->dev, "Failed! (%02x)\n", temp);
	return -1;
	} else {
	dev_dbg(&I801_dev->dev, "Successful!\n");
	}
	}

	/* the current contents of SMBHSTCNT can be overwritten, since PEC,
	* INTREN, SMBSCMD are passed in xact */
	outb_p(xact \| I801_START, SMBHSTCNT);

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

	/* If the SMBus is still busy, we give up */
	if (timeout >= MAX_TIMEOUT) {
	dev_dbg(&I801_dev->dev, "SMBus Timeout!\n");
	result = -1;
	/* try to stop the current command */
	dev_dbg(&I801_dev->dev, "Terminating the current operation\n");
	outb_p(inb_p(SMBHSTCNT) \| SMBHSTCNT_KILL, SMBHSTCNT);
	msleep(1);
	outb_p(inb_p(SMBHSTCNT) & (~SMBHSTCNT_KILL), SMBHSTCNT);
	}

	if (temp & SMBHSTSTS_FAILED) {
	result = -1;
	dev_dbg(&I801_dev->dev, "Error: Failed bus transaction\n");
	}

	if (temp & SMBHSTSTS_BUS_ERR) {
	result = -1;
	dev_err(&I801_dev->dev, "Bus collision! SMBus may be locked "
	"until next hard reset. (sorry!)\n");
	/* Clock stops and slave is stuck in mid-transmission */
	}

	if (temp & SMBHSTSTS_DEV_ERR) {
	result = -1;
	dev_dbg(&I801_dev->dev, "Error: no response!\n");
	}

	if ((inb_p(SMBHSTSTS) & 0x1f) != 0x00)
	outb_p(inb(SMBHSTSTS), SMBHSTSTS);

	if ((temp = (0x1f & inb_p(SMBHSTSTS))) != 0x00) {
	dev_dbg(&I801_dev->dev, "Failed reset at end of transaction "
	"(%02x)\n", temp);
	}
	dev_dbg(&I801_dev->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;
	}

	/* wait for INTR bit as advised by Intel */
	static void i801_wait_hwpec(void)
	{
	int timeout = 0;
	int temp;

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

	if (timeout >= MAX_TIMEOUT) {
	dev_dbg(&I801_dev->dev, "PEC Timeout!\n");
	}
	outb_p(temp, SMBHSTSTS);
	}

	static int i801_block_transaction_by_block(union i2c_smbus_data *data,
	char read_write, int hwpec)
	{
	int i, len;

	inb_p(SMBHSTCNT); /* reset the data buffer index */

	/* Use 32-byte buffer to process this transaction */
	if (read_write == I2C_SMBUS_WRITE) {
	len = data->block[0];
	outb_p(len, SMBHSTDAT0);
	for (i = 0; i < len; i++)
	outb_p(data->block[i+1], SMBBLKDAT);
	}

	if (i801_transaction(I801_BLOCK_DATA \| ENABLE_INT9 \|
	I801_PEC_EN * hwpec))
	return -1;

	if (read_write == I2C_SMBUS_READ) {
	len = inb_p(SMBHSTDAT0);
	if (len < 1 \|\| len > I2C_SMBUS_BLOCK_MAX)
	return -1;

	data->block[0] = len;
	for (i = 0; i < len; i++)
	data->block[i + 1] = inb_p(SMBBLKDAT);
	}
	return 0;
	}

	static int i801_block_transaction_byte_by_byte(union i2c_smbus_data *data,
	char read_write, int command,
	int hwpec)
	{
	int i, len;
	int smbcmd;
	int temp;
	int result = 0;
	int timeout;
	unsigned char errmask;

	len = data->block[0];

	if (read_write == I2C_SMBUS_WRITE) {
	outb_p(len, SMBHSTDAT0);
	outb_p(data->block[1], SMBBLKDAT);
	}

	for (i = 1; i <= len; i++) {
	if (i == len && read_write == I2C_SMBUS_READ) {
	if (command == I2C_SMBUS_I2C_BLOCK_DATA)
	smbcmd = I801_I2C_BLOCK_LAST;
	else
	smbcmd = I801_BLOCK_LAST;
	} else {
	if (command == I2C_SMBUS_I2C_BLOCK_DATA
	&& read_write == I2C_SMBUS_READ)
	smbcmd = I801_I2C_BLOCK_DATA;
	else
	smbcmd = I801_BLOCK_DATA;
	}
	outb_p(smbcmd \| ENABLE_INT9, SMBHSTCNT);

	dev_dbg(&I801_dev->dev, "Block (pre %d): CNT=%02x, CMD=%02x, "
	"ADD=%02x, DAT0=%02x, DAT1=%02x, BLKDAT=%02x\n", i,
	inb_p(SMBHSTCNT), inb_p(SMBHSTCMD), inb_p(SMBHSTADD),
	inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1), inb_p(SMBBLKDAT));

	/* Make sure the SMBus host is ready to start transmitting */
	temp = inb_p(SMBHSTSTS);
	if (i == 1) {
	/* Erroneous conditions before transaction:
	* Byte_Done, Failed, Bus_Err, Dev_Err, Intr, Host_Busy */
	errmask = 0x9f;
	} else {
	/* Erroneous conditions during transaction:
	* Failed, Bus_Err, Dev_Err, Intr */
	errmask = 0x1e;
	}
	if (temp & errmask) {
	dev_dbg(&I801_dev->dev, "SMBus busy (%02x). "
	"Resetting...\n", temp);
	outb_p(temp, SMBHSTSTS);
	if (((temp = inb_p(SMBHSTSTS)) & errmask) != 0x00) {
	dev_err(&I801_dev->dev,
	"Reset failed! (%02x)\n", temp);
	return -1;
	}
	if (i != 1)
	/* if die in middle of block transaction, fail */
	return -1;
	}

	if (i == 1)
	outb_p(inb(SMBHSTCNT) \| I801_START, SMBHSTCNT);

	/* We will always wait for a fraction of a second! */
	timeout = 0;
	do {
	msleep(1);
	temp = inb_p(SMBHSTSTS);
	}
	while ((!(temp & SMBHSTSTS_BYTE_DONE))
	&& (timeout++ < MAX_TIMEOUT));

	/* If the SMBus is still busy, we give up */
	if (timeout >= MAX_TIMEOUT) {
	/* try to stop the current command */
	dev_dbg(&I801_dev->dev, "Terminating the current "
	"operation\n");
	outb_p(inb_p(SMBHSTCNT) \| SMBHSTCNT_KILL, SMBHSTCNT);
	msleep(1);
	outb_p(inb_p(SMBHSTCNT) & (~SMBHSTCNT_KILL),
	SMBHSTCNT);
	result = -1;
	dev_dbg(&I801_dev->dev, "SMBus Timeout!\n");
	}

	if (temp & SMBHSTSTS_FAILED) {
	result = -1;
	dev_dbg(&I801_dev->dev,
	"Error: Failed bus transaction\n");
	} else if (temp & SMBHSTSTS_BUS_ERR) {
	result = -1;
	dev_err(&I801_dev->dev, "Bus collision!\n");
	} else if (temp & SMBHSTSTS_DEV_ERR) {
	result = -1;
	dev_dbg(&I801_dev->dev, "Error: no response!\n");
	}

	if (i == 1 && read_write == I2C_SMBUS_READ
	&& command != I2C_SMBUS_I2C_BLOCK_DATA) {
	len = inb_p(SMBHSTDAT0);
	if (len < 1 \|\| len > I2C_SMBUS_BLOCK_MAX)
	return -1;
	data->block[0] = len;
	}

	/* Retrieve/store value in SMBBLKDAT */
	if (read_write == I2C_SMBUS_READ)
	data->block[i] = inb_p(SMBBLKDAT);
	if (read_write == I2C_SMBUS_WRITE && i+1 <= len)
	outb_p(data->block[i+1], SMBBLKDAT);
	if ((temp & 0x9e) != 0x00)
	outb_p(temp, SMBHSTSTS); /* signals SMBBLKDAT ready */

	if ((temp = (0x1e & inb_p(SMBHSTSTS))) != 0x00) {
	dev_dbg(&I801_dev->dev,
	"Bad status (%02x) at end of transaction\n",
	temp);
	}
	dev_dbg(&I801_dev->dev, "Block (post %d): CNT=%02x, CMD=%02x, "
	"ADD=%02x, DAT0=%02x, DAT1=%02x, BLKDAT=%02x\n", i,
	inb_p(SMBHSTCNT), inb_p(SMBHSTCMD), inb_p(SMBHSTADD),
	inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1), inb_p(SMBBLKDAT));

	if (result < 0)
	return result;
	}
	return result;
	}

	static int i801_set_block_buffer_mode(void)
	{
	outb_p(inb_p(SMBAUXCTL) \| SMBAUXCTL_E32B, SMBAUXCTL);
	if ((inb_p(SMBAUXCTL) & SMBAUXCTL_E32B) == 0)
	return -1;
	return 0;
	}

	/* Block transaction function */
	static int i801_block_transaction(union i2c_smbus_data *data, char read_write,
	int command, int hwpec)
	{
	int result = 0;
	unsigned char hostc;

	if (command == I2C_SMBUS_I2C_BLOCK_DATA) {
	if (read_write == I2C_SMBUS_WRITE) {
	/* set I2C_EN bit in configuration register */
	pci_read_config_byte(I801_dev, SMBHSTCFG, &hostc);
	pci_write_config_byte(I801_dev, SMBHSTCFG,
	hostc \| SMBHSTCFG_I2C_EN);
	} else if (!(i801_features & FEATURE_I2C_BLOCK_READ)) {
	dev_err(&I801_dev->dev,
	"I2C block read is unsupported!\n");
	return -1;
	}
	}

	if (read_write == I2C_SMBUS_WRITE
	\|\| command == I2C_SMBUS_I2C_BLOCK_DATA) {
	if (data->block[0] < 1)
	data->block[0] = 1;
	if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
	data->block[0] = I2C_SMBUS_BLOCK_MAX;
	} else {
	data->block[0] = 32; /* max for SMBus block reads */
	}

	if ((i801_features & FEATURE_BLOCK_BUFFER)
	&& !(command == I2C_SMBUS_I2C_BLOCK_DATA
	&& read_write == I2C_SMBUS_READ)
	&& i801_set_block_buffer_mode() == 0)
	result = i801_block_transaction_by_block(data, read_write,
	hwpec);
	else
	result = i801_block_transaction_byte_by_byte(data, read_write,
	command, hwpec);

	if (result == 0 && hwpec)
	i801_wait_hwpec();

	if (command == I2C_SMBUS_I2C_BLOCK_DATA
	&& read_write == I2C_SMBUS_WRITE) {
	/* restore saved configuration register value */
	pci_write_config_byte(I801_dev, SMBHSTCFG, hostc);
	}
	return result;
	}

	/* Return -1 on error. */
	static s32 i801_access(struct i2c_adapter * adap, u16 addr,
	unsigned short flags, char read_write, u8 command,
	int size, union i2c_smbus_data * data)
	{
	int hwpec;
	int block = 0;
	int ret, xact = 0;

	hwpec = (i801_features & FEATURE_SMBUS_PEC) && (flags & I2C_CLIENT_PEC)
	&& size != I2C_SMBUS_QUICK
	&& size != I2C_SMBUS_I2C_BLOCK_DATA;

	switch (size) {
	case I2C_SMBUS_QUICK:
	outb_p(((addr & 0x7f) << 1) \| (read_write & 0x01),
	SMBHSTADD);
	xact = I801_QUICK;
	break;
	case I2C_SMBUS_BYTE:
	outb_p(((addr & 0x7f) << 1) \| (read_write & 0x01),
	SMBHSTADD);
	if (read_write == I2C_SMBUS_WRITE)
	outb_p(command, SMBHSTCMD);
	xact = I801_BYTE;
	break;
	case I2C_SMBUS_BYTE_DATA:
	outb_p(((addr & 0x7f) << 1) \| (read_write & 0x01),
	SMBHSTADD);
	outb_p(command, SMBHSTCMD);
	if (read_write == I2C_SMBUS_WRITE)
	outb_p(data->byte, SMBHSTDAT0);
	xact = I801_BYTE_DATA;
	break;
	case I2C_SMBUS_WORD_DATA:
	outb_p(((addr & 0x7f) << 1) \| (read_write & 0x01),
	SMBHSTADD);
	outb_p(command, SMBHSTCMD);
	if (read_write == I2C_SMBUS_WRITE) {
	outb_p(data->word & 0xff, SMBHSTDAT0);
	outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
	}
	xact = I801_WORD_DATA;
	break;
	case I2C_SMBUS_BLOCK_DATA:
	outb_p(((addr & 0x7f) << 1) \| (read_write & 0x01),
	SMBHSTADD);
	outb_p(command, SMBHSTCMD);
	block = 1;
	break;
	case I2C_SMBUS_I2C_BLOCK_DATA:
	/* NB: page 240 of ICH5 datasheet shows that the R/#W
	* bit should be cleared here, even when reading */
	outb_p((addr & 0x7f) << 1, SMBHSTADD);
	if (read_write == I2C_SMBUS_READ) {
	/* NB: page 240 of ICH5 datasheet also shows
	* that DATA1 is the cmd field when reading */
	outb_p(command, SMBHSTDAT1);
	} else
	outb_p(command, SMBHSTCMD);
	block = 1;
	break;
	case I2C_SMBUS_PROC_CALL:
	default:
	dev_err(&I801_dev->dev, "Unsupported transaction %d\n", size);
	return -1;
	}

	if (hwpec) /* enable/disable hardware PEC */
	outb_p(inb_p(SMBAUXCTL) \| SMBAUXCTL_CRC, SMBAUXCTL);
	else
	outb_p(inb_p(SMBAUXCTL) & (~SMBAUXCTL_CRC), SMBAUXCTL);

	if(block)
	ret = i801_block_transaction(data, read_write, size, hwpec);
	else
	ret = i801_transaction(xact \| ENABLE_INT9);

	/* Some BIOSes don't like it when PEC is enabled at reboot or resume
	time, so we forcibly disable it after every transaction. Turn off
	E32B for the same reason. */
	if (hwpec \|\| block)
	outb_p(inb_p(SMBAUXCTL) & ~(SMBAUXCTL_CRC \| SMBAUXCTL_E32B),
	SMBAUXCTL);

	if(block)
	return ret;
	if(ret)
	return -1;
	if ((read_write == I2C_SMBUS_WRITE) \|\| (xact == I801_QUICK))
	return 0;

	switch (xact & 0x7f) {
	case I801_BYTE: /* Result put in SMBHSTDAT0 */
	case I801_BYTE_DATA:
	data->byte = inb_p(SMBHSTDAT0);
	break;
	case I801_WORD_DATA:
	data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
	break;
	}
	return 0;
	}


	static u32 i801_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 \| I2C_FUNC_SMBUS_WRITE_I2C_BLOCK \|
	((i801_features & FEATURE_SMBUS_PEC) ? I2C_FUNC_SMBUS_PEC : 0) \|
	((i801_features & FEATURE_I2C_BLOCK_READ) ?
	I2C_FUNC_SMBUS_READ_I2C_BLOCK : 0);
	}

	static const struct i2c_algorithm smbus_algorithm = {
	.smbus_xfer = i801_access,
	.functionality = i801_func,
	};

	static struct i2c_adapter i801_adapter = {
	.owner = THIS_MODULE,
	.id = I2C_HW_SMBUS_I801,
	.class = I2C_CLASS_HWMON,
	.algo = &smbus_algorithm,
	};

	static struct pci_device_id i801_ids[] = {
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801AA_3) },
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801AB_3) },
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801BA_2) },
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801CA_3) },
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801DB_3) },
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801EB_3) },
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ESB_4) },
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH6_16) },
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH7_17) },
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ESB2_17) },
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH8_5) },
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH9_6) },
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_TOLAPAI_1) },
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH10_4) },
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH10_5) },
	{ 0, }
	};

	MODULE_DEVICE_TABLE (pci, i801_ids);

	static int __devinit i801_probe(struct pci_dev dev, const struct pci_device_id id)
	{
	unsigned char temp;
	int err;

	I801_dev = dev;
	i801_features = 0;
	switch (dev->device) {
	case PCI_DEVICE_ID_INTEL_82801EB_3:
	case PCI_DEVICE_ID_INTEL_ESB_4:
	case PCI_DEVICE_ID_INTEL_ICH6_16:
	case PCI_DEVICE_ID_INTEL_ICH7_17:
	case PCI_DEVICE_ID_INTEL_ESB2_17:
	case PCI_DEVICE_ID_INTEL_ICH8_5:
	case PCI_DEVICE_ID_INTEL_ICH9_6:
	case PCI_DEVICE_ID_INTEL_TOLAPAI_1:
	case PCI_DEVICE_ID_INTEL_ICH10_4:
	case PCI_DEVICE_ID_INTEL_ICH10_5:
	i801_features \|= FEATURE_I2C_BLOCK_READ;
	/* fall through */
	case PCI_DEVICE_ID_INTEL_82801DB_3:
	i801_features \|= FEATURE_SMBUS_PEC;
	i801_features \|= FEATURE_BLOCK_BUFFER;
	break;
	}

	err = pci_enable_device(dev);
	if (err) {
	dev_err(&dev->dev, "Failed to enable SMBus PCI device (%d)\n",
	err);
	goto exit;
	}

	/* Determine the address of the SMBus area */
	i801_smba = pci_resource_start(dev, SMBBAR);
	if (!i801_smba) {
	dev_err(&dev->dev, "SMBus base address uninitialized, "
	"upgrade BIOS\n");
	err = -ENODEV;
	goto exit;
	}

	err = pci_request_region(dev, SMBBAR, i801_driver.name);
	if (err) {
	dev_err(&dev->dev, "Failed to request SMBus region "
	"0x%lx-0x%Lx\n", i801_smba,
	(unsigned long long)pci_resource_end(dev, SMBBAR));
	goto exit;
	}

	pci_read_config_byte(I801_dev, SMBHSTCFG, &temp);
	i801_original_hstcfg = temp;
	temp &= ~SMBHSTCFG_I2C_EN; /* SMBus timing */
	if (!(temp & SMBHSTCFG_HST_EN)) {
	dev_info(&dev->dev, "Enabling SMBus device\n");
	temp \|= SMBHSTCFG_HST_EN;
	}
	pci_write_config_byte(I801_dev, SMBHSTCFG, temp);

	if (temp & SMBHSTCFG_SMB_SMI_EN)
	dev_dbg(&dev->dev, "SMBus using interrupt SMI#\n");
	else
	dev_dbg(&dev->dev, "SMBus using PCI Interrupt\n");

	/* Clear special mode bits */
	if (i801_features & (FEATURE_SMBUS_PEC \| FEATURE_BLOCK_BUFFER))
	outb_p(inb_p(SMBAUXCTL) & ~(SMBAUXCTL_CRC \| SMBAUXCTL_E32B),
	SMBAUXCTL);

	/* set up the sysfs linkage to our parent device */
	i801_adapter.dev.parent = &dev->dev;

	snprintf(i801_adapter.name, sizeof(i801_adapter.name),
	"SMBus I801 adapter at %04lx", i801_smba);
	err = i2c_add_adapter(&i801_adapter);
	if (err) {
	dev_err(&dev->dev, "Failed to add SMBus adapter\n");
	goto exit_release;
	}
	return 0;

	exit_release:
	pci_release_region(dev, SMBBAR);
	exit:
	return err;
	}

	static void __devexit i801_remove(struct pci_dev *dev)
	{
	i2c_del_adapter(&i801_adapter);
	pci_write_config_byte(I801_dev, SMBHSTCFG, i801_original_hstcfg);
	pci_release_region(dev, SMBBAR);
	/*
	* do not call pci_disable_device(dev) since it can cause hard hangs on
	* some systems during power-off (eg. Fujitsu-Siemens Lifebook E8010)
	*/
	}

	#ifdef CONFIG_PM
	static int i801_suspend(struct pci_dev *dev, pm_message_t mesg)
	{
	pci_save_state(dev);
	pci_write_config_byte(dev, SMBHSTCFG, i801_original_hstcfg);
	pci_set_power_state(dev, pci_choose_state(dev, mesg));
	return 0;
	}

	static int i801_resume(struct pci_dev *dev)
	{
	pci_set_power_state(dev, PCI_D0);
	pci_restore_state(dev);
	return pci_enable_device(dev);
	}
	#else
	#define i801_suspend NULL
	#define i801_resume NULL
	#endif

	static struct pci_driver i801_driver = {
	.name = "i801_smbus",
	.id_table = i801_ids,
	.probe = i801_probe,
	.remove = __devexit_p(i801_remove),
	.suspend = i801_suspend,
	.resume = i801_resume,
	};

	static int __init i2c_i801_init(void)
	{
	return pci_register_driver(&i801_driver);
	}

	static void __exit i2c_i801_exit(void)
	{
	pci_unregister_driver(&i801_driver);
	}

	MODULE_AUTHOR("Mark D. Studebaker <mdsxyz123@yahoo.com>, "
	"Jean Delvare <khali@linux-fr.org>");
	MODULE_DESCRIPTION("I801 SMBus driver");
	MODULE_LICENSE("GPL");

	module_init(i2c_i801_init);
	module_exit(i2c_i801_exit);