/**
   *	i2c-ali1563.c - i2c driver for the ALi 1563 Southbridge
   *
   *	Copyright (C) 2004 Patrick Mochel

   *		      2005 Rudolf Marek <r.marek@assembler.cz>

   *
   *	The 1563 southbridge is deceptively similar to the 1533, with a
   *	few notable exceptions. One of those happens to be the fact they
   *	upgraded the i2c core to be 2.0 compliant, and happens to be almost
   *	identical to the i2c controller found in the Intel 801 south
   *	bridges.
   *
   *	This driver is based on a mix of the 15x3, 1535, and i801 drivers,
   *	with a little help from the ALi 1563 spec.
   *
   *	This file is released under the GPLv2
   */
  
  #include <linux/module.h>
  #include <linux/delay.h>
  #include <linux/i2c.h>
  #include <linux/pci.h>
  #include <linux/init.h>

  #include <linux/acpi.h>

  
  #define ALI1563_MAX_TIMEOUT	500
  #define	ALI1563_SMBBA		0x80
  #define ALI1563_SMB_IOEN	1
  #define ALI1563_SMB_HOSTEN	2
  #define ALI1563_SMB_IOSIZE	16
  
  #define SMB_HST_STS	(ali1563_smba + 0)
  #define SMB_HST_CNTL1	(ali1563_smba + 1)
  #define SMB_HST_CNTL2	(ali1563_smba + 2)
  #define SMB_HST_CMD	(ali1563_smba + 3)
  #define SMB_HST_ADD	(ali1563_smba + 4)
  #define SMB_HST_DAT0	(ali1563_smba + 5)
  #define SMB_HST_DAT1	(ali1563_smba + 6)
  #define SMB_BLK_DAT	(ali1563_smba + 7)
  
  #define HST_STS_BUSY	0x01
  #define HST_STS_INTR	0x02
  #define HST_STS_DEVERR	0x04
  #define HST_STS_BUSERR	0x08
  #define HST_STS_FAIL	0x10
  #define HST_STS_DONE	0x80
  #define HST_STS_BAD	0x1c
  
  
  #define HST_CNTL1_TIMEOUT	0x80
  #define HST_CNTL1_LAST		0x40
  
  #define HST_CNTL2_KILL		0x04
  #define HST_CNTL2_START		0x40
  #define HST_CNTL2_QUICK		0x00
  #define HST_CNTL2_BYTE		0x01
  #define HST_CNTL2_BYTE_DATA	0x02
  #define HST_CNTL2_WORD_DATA	0x03
  #define HST_CNTL2_BLOCK		0x05

  #define HST_CNTL2_SIZEMASK	0x38

  static struct pci_driver ali1563_pci_driver;

  static unsigned short ali1563_smba;

  static int ali1563_transaction(struct i2c_adapter * a, int size)

  {
  	u32 data;
  	int timeout;

  	int status = -EIO;

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

  		dev_err(&a->dev, "ali1563: Trying to reset busy device
  ");

  		outb_p(data | HST_STS_BAD,SMB_HST_STS);
  		data = inb_p(SMB_HST_STS);
  		if (data & HST_STS_BAD)
  			return -EBUSY;
  	}
  	outb_p(inb_p(SMB_HST_CNTL2) | HST_CNTL2_START, SMB_HST_CNTL2);
  
  	timeout = ALI1563_MAX_TIMEOUT;

  	do {

  		msleep(1);

  	} while (((data = inb_p(SMB_HST_STS)) & HST_STS_BUSY) && --timeout);

  
  	dev_dbg(&a->dev, "Transaction (post): STS=%02x, CNTL1=%02x, "
  		"CNTL2=%02x, CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x
  ",
  		inb_p(SMB_HST_STS), inb_p(SMB_HST_CNTL1), inb_p(SMB_HST_CNTL2),
  		inb_p(SMB_HST_CMD), inb_p(SMB_HST_ADD), inb_p(SMB_HST_DAT0),
  		inb_p(SMB_HST_DAT1));
  
  	if (timeout && !(data & HST_STS_BAD))
  		return 0;

  	if (!timeout) {
  		dev_err(&a->dev, "Timeout - Trying to KILL transaction!
  ");

  		/* Issue 'kill' to host controller */
  		outb_p(HST_CNTL2_KILL,SMB_HST_CNTL2);

  		data = inb_p(SMB_HST_STS);

  		status = -ETIMEDOUT;

   	}
  
  	/* device error - no response, ignore the autodetection case */

  	if (data & HST_STS_DEVERR) {
  		if (size != HST_CNTL2_QUICK)
  			dev_err(&a->dev, "Device error!
  ");
  		status = -ENXIO;

  	}

  	/* bus collision */
  	if (data & HST_STS_BUSERR) {
  		dev_err(&a->dev, "Bus collision!
  ");
  		/* Issue timeout, hoping it helps */

  		outb_p(HST_CNTL1_TIMEOUT,SMB_HST_CNTL1);

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

  	return status;

  }
  
  static int ali1563_block_start(struct i2c_adapter * a)
  {
  	u32 data;
  	int timeout;

  	int status = -EIO;

  
  	dev_dbg(&a->dev, "Block (pre): STS=%02x, CNTL1=%02x, "
  		"CNTL2=%02x, CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x
  ",
  		inb_p(SMB_HST_STS), inb_p(SMB_HST_CNTL1), inb_p(SMB_HST_CNTL2),
  		inb_p(SMB_HST_CMD), inb_p(SMB_HST_ADD), inb_p(SMB_HST_DAT0),
  		inb_p(SMB_HST_DAT1));
  
  	data = inb_p(SMB_HST_STS);
  	if (data & HST_STS_BAD) {
  		dev_warn(&a->dev,"ali1563: Trying to reset busy device
  ");
  		outb_p(data | HST_STS_BAD,SMB_HST_STS);
  		data = inb_p(SMB_HST_STS);
  		if (data & HST_STS_BAD)
  			return -EBUSY;
  	}
  
  	/* Clear byte-ready bit */
  	outb_p(data | HST_STS_DONE, SMB_HST_STS);
  
  	/* Start transaction and wait for byte-ready bit to be set */
  	outb_p(inb_p(SMB_HST_CNTL2) | HST_CNTL2_START, SMB_HST_CNTL2);
  
  	timeout = ALI1563_MAX_TIMEOUT;

  	do {

  		msleep(1);

  	} while (!((data = inb_p(SMB_HST_STS)) & HST_STS_DONE) && --timeout);

  
  	dev_dbg(&a->dev, "Block (post): STS=%02x, CNTL1=%02x, "
  		"CNTL2=%02x, CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x
  ",
  		inb_p(SMB_HST_STS), inb_p(SMB_HST_CNTL1), inb_p(SMB_HST_CNTL2),
  		inb_p(SMB_HST_CMD), inb_p(SMB_HST_ADD), inb_p(SMB_HST_DAT0),
  		inb_p(SMB_HST_DAT1));
  
  	if (timeout && !(data & HST_STS_BAD))
  		return 0;

  
  	if (timeout == 0)
  		status = -ETIMEDOUT;
  
  	if (data & HST_STS_DEVERR)
  		status = -ENXIO;

  	dev_err(&a->dev, "SMBus Error: %s%s%s%s%s
  ",

  		timeout ? "" : "Timeout ",

  		data & HST_STS_FAIL ? "Transaction Failed " : "",
  		data & HST_STS_BUSERR ? "No response or Bus Collision " : "",
  		data & HST_STS_DEVERR ? "Device Error " : "",
  		!(data & HST_STS_DONE) ? "Transaction Never Finished " : "");

  	return status;

  }
  
  static int ali1563_block(struct i2c_adapter * a, union i2c_smbus_data * data, u8 rw)
  {
  	int i, len;
  	int error = 0;
  
  	/* Do we need this? */
  	outb_p(HST_CNTL1_LAST,SMB_HST_CNTL1);
  
  	if (rw == I2C_SMBUS_WRITE) {
  		len = data->block[0];
  		if (len < 1)
  			len = 1;
  		else if (len > 32)
  			len = 32;
  		outb_p(len,SMB_HST_DAT0);
  		outb_p(data->block[1],SMB_BLK_DAT);
  	} else
  		len = 32;
  
  	outb_p(inb_p(SMB_HST_CNTL2) | HST_CNTL2_BLOCK, SMB_HST_CNTL2);
  
  	for (i = 0; i < len; i++) {
  		if (rw == I2C_SMBUS_WRITE) {
  			outb_p(data->block[i + 1], SMB_BLK_DAT);
  			if ((error = ali1563_block_start(a)))
  				break;
  		} else {
  			if ((error = ali1563_block_start(a)))
  				break;
  			if (i == 0) {
  				len = inb_p(SMB_HST_DAT0);
  				if (len < 1)
  					len = 1;
  				else if (len > 32)
  					len = 32;
  			}
  			data->block[i+1] = inb_p(SMB_BLK_DAT);
  		}
  	}
  	/* Do we need this? */
  	outb_p(HST_CNTL1_LAST,SMB_HST_CNTL1);
  	return error;
  }
  
  static s32 ali1563_access(struct i2c_adapter * a, u16 addr,
  			  unsigned short flags, char rw, u8 cmd,
  			  int size, union i2c_smbus_data * data)
  {
  	int error = 0;
  	int timeout;
  	u32 reg;
  
  	for (timeout = ALI1563_MAX_TIMEOUT; timeout; timeout--) {
  		if (!(reg = inb_p(SMB_HST_STS) & HST_STS_BUSY))
  			break;
  	}
  	if (!timeout)
  		dev_warn(&a->dev,"SMBus not idle. HST_STS = %02x
  ",reg);
  	outb_p(0xff,SMB_HST_STS);
  
  	/* Map the size to what the chip understands */
  	switch (size) {

  	case I2C_SMBUS_QUICK:
  		size = HST_CNTL2_QUICK;
  		break;
  	case I2C_SMBUS_BYTE:
  		size = HST_CNTL2_BYTE;
  		break;
  	case I2C_SMBUS_BYTE_DATA:
  		size = HST_CNTL2_BYTE_DATA;
  		break;
  	case I2C_SMBUS_WORD_DATA:
  		size = HST_CNTL2_WORD_DATA;
  		break;
  	case I2C_SMBUS_BLOCK_DATA:
  		size = HST_CNTL2_BLOCK;
  		break;

  	default:
  		dev_warn(&a->dev, "Unsupported transaction %d
  ", size);
  		error = -EOPNOTSUPP;
  		goto Done;

  	}
  
  	outb_p(((addr & 0x7f) << 1) | (rw & 0x01), SMB_HST_ADD);

  	outb_p((inb_p(SMB_HST_CNTL2) & ~HST_CNTL2_SIZEMASK) | (size << 3), SMB_HST_CNTL2);

  
  	/* Write the command register */

  	switch(size) {
  	case HST_CNTL2_BYTE:
  		if (rw== I2C_SMBUS_WRITE)

  			/* Beware it uses DAT0 register and not CMD! */
  			outb_p(cmd, SMB_HST_DAT0);

  		break;
  	case HST_CNTL2_BYTE_DATA:
  		outb_p(cmd, SMB_HST_CMD);
  		if (rw == I2C_SMBUS_WRITE)
  			outb_p(data->byte, SMB_HST_DAT0);
  		break;
  	case HST_CNTL2_WORD_DATA:
  		outb_p(cmd, SMB_HST_CMD);
  		if (rw == I2C_SMBUS_WRITE) {
  			outb_p(data->word & 0xff, SMB_HST_DAT0);
  			outb_p((data->word & 0xff00) >> 8, SMB_HST_DAT1);
  		}
  		break;
  	case HST_CNTL2_BLOCK:
  		outb_p(cmd, SMB_HST_CMD);
  		error = ali1563_block(a,data,rw);
  		goto Done;
  	}

  	if ((error = ali1563_transaction(a, size)))

  		goto Done;
  
  	if ((rw == I2C_SMBUS_WRITE) || (size == HST_CNTL2_QUICK))
  		goto Done;
  
  	switch (size) {
  	case HST_CNTL2_BYTE:	/* Result put in SMBHSTDAT0 */
  		data->byte = inb_p(SMB_HST_DAT0);
  		break;
  	case HST_CNTL2_BYTE_DATA:
  		data->byte = inb_p(SMB_HST_DAT0);
  		break;
  	case HST_CNTL2_WORD_DATA:
  		data->word = inb_p(SMB_HST_DAT0) + (inb_p(SMB_HST_DAT1) << 8);
  		break;
  	}
  Done:
  	return error;
  }
  
  static u32 ali1563_func(struct i2c_adapter * a)
  {
  	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
  	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
  	    I2C_FUNC_SMBUS_BLOCK_DATA;
  }

  static int __devinit ali1563_setup(struct pci_dev * dev)
  {
  	u16 ctrl;
  
  	pci_read_config_word(dev,ALI1563_SMBBA,&ctrl);

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

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

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

  	if (!request_region(ali1563_smba, ALI1563_SMB_IOSIZE,
  			    ali1563_pci_driver.name)) {

  		dev_err(&dev->dev, "Could not allocate I/O space at 0x%04x
  ",
  			ali1563_smba);

  		goto Err;
  	}

  	dev_info(&dev->dev, "Found ALi1563 SMBus at 0x%04x
  ", ali1563_smba);

  
  	return 0;
  Err:
  	return -ENODEV;
  }
  
  static void ali1563_shutdown(struct pci_dev *dev)
  {
  	release_region(ali1563_smba,ALI1563_SMB_IOSIZE);
  }

  static const struct i2c_algorithm ali1563_algorithm = {

  	.smbus_xfer	= ali1563_access,
  	.functionality	= ali1563_func,
  };
  
  static struct i2c_adapter ali1563_adapter = {
  	.owner	= THIS_MODULE,

  	.class	= I2C_CLASS_HWMON | I2C_CLASS_SPD,

  	.algo	= &ali1563_algorithm,
  };
  
  static int __devinit ali1563_probe(struct pci_dev * dev,
  				const struct pci_device_id * id_table)
  {
  	int error;
  
  	if ((error = ali1563_setup(dev)))

  		goto exit;

  	ali1563_adapter.dev.parent = &dev->dev;

  	snprintf(ali1563_adapter.name, sizeof(ali1563_adapter.name),
  		 "SMBus ALi 1563 Adapter @ %04x", ali1563_smba);

  	if ((error = i2c_add_adapter(&ali1563_adapter)))

  		goto exit_shutdown;
  	return 0;
  
  exit_shutdown:
  	ali1563_shutdown(dev);
  exit:
  	dev_warn(&dev->dev, "ALi1563 SMBus probe failed (%d)
  ", error);

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

  static DEFINE_PCI_DEVICE_TABLE(ali1563_id_table) = {

  	{ PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1563) },
  	{},
  };
  
  MODULE_DEVICE_TABLE (pci, ali1563_id_table);
  
  static struct pci_driver ali1563_pci_driver = {

   	.name		= "ali1563_smbus",

  	.id_table	= ali1563_id_table,
   	.probe		= ali1563_probe,
  	.remove		= __devexit_p(ali1563_remove),
  };
  
  static int __init ali1563_init(void)
  {
  	return pci_register_driver(&ali1563_pci_driver);
  }
  
  module_init(ali1563_init);
  
  static void __exit ali1563_exit(void)
  {
  	pci_unregister_driver(&ali1563_pci_driver);
  }
  
  module_exit(ali1563_exit);
  
  MODULE_LICENSE("GPL");