text: /*
      SMBus driver for nVidia nForce2 MCP
  
      Added nForce3 Pro 150  Thomas Leibold <thomas@plx.com>,
  	Ported to 2.5 Patrick Dreker <patrick@dreker.de>,
      Copyright (c) 2003  Hans-Frieder Vogt <hfvogt@arcor.de>,
      Based on
      SMBus 2.0 driver for AMD-8111 IO-Hub
      Copyright (c) 2002 Vojtech Pavlik
  
      This program is free software; you can redistribute it and/or modify
      it under the terms of the GNU General Public License as published by
      the Free Software Foundation; either version 2 of the License, or
      (at your option) any later version.
  
      This program is distributed in the hope that it will be useful,
      but WITHOUT ANY WARRANTY; without even the implied warranty of
      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      GNU General Public License for more details.
  
      You should have received a copy of the GNU General Public License
      along with this program; if not, write to the Free Software
      Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
  
  /*
      SUPPORTED DEVICES		PCI ID
      nForce2 MCP			0064
      nForce2 Ultra 400 MCP	0084
      nForce3 Pro150 MCP		00D4
      nForce3 250Gb MCP		00E4
      nForce4 MCP			0052
      nForce4 MCP-04		0034
      nForce MCP51		0264
      nForce MCP55		0368
      nForce MCP61		03EB
      nForce MCP65		0446
      nForce MCP67		0542
      nForce MCP73		07D8
      nForce MCP78S		0752
      nForce MCP79		0AA2
  
      This driver supports the 2 SMBuses that are included in the MCP of the
      nForce2/3/4/5xx chipsets.
  */
  
  /* Note: we assume there can only be one nForce2, with two SMBus interfaces */
  
  #include <linux/module.h>
  #include <linux/pci.h>
  #include <linux/kernel.h>
  #include <linux/stddef.h>
  #include <linux/ioport.h>
  #include <linux/init.h>
  #include <linux/i2c.h>
  #include <linux/delay.h>
  #include <linux/dmi.h>
  #include <linux/acpi.h>
  #include <linux/slab.h>
  #include <linux/io.h>
  
  MODULE_LICENSE("GPL");
  MODULE_AUTHOR ("Hans-Frieder Vogt <hfvogt@gmx.net>");
  MODULE_DESCRIPTION("nForce2/3/4/5xx SMBus driver");
  
  
  struct nforce2_smbus {
  	struct i2c_adapter adapter;
  	int base;
  	int size;
  	int blockops;
  	int can_abort;
  };
  
  
  /*
   * nVidia nForce2 SMBus control register definitions
   * (Newer incarnations use standard BARs 4 and 5 instead)
   */
  #define NFORCE_PCI_SMB1	0x50
  #define NFORCE_PCI_SMB2	0x54
  
  
  /*
   * ACPI 2.0 chapter 13 SMBus 2.0 EC register model
   */
  #define NVIDIA_SMB_PRTCL	(smbus->base + 0x00)	/* protocol, PEC */
  #define NVIDIA_SMB_STS		(smbus->base + 0x01)	/* status */
  #define NVIDIA_SMB_ADDR		(smbus->base + 0x02)	/* address */
  #define NVIDIA_SMB_CMD		(smbus->base + 0x03)	/* command */
  #define NVIDIA_SMB_DATA		(smbus->base + 0x04)	/* 32 data registers */
  #define NVIDIA_SMB_BCNT		(smbus->base + 0x24)	/* number of data
  							   bytes */
  #define NVIDIA_SMB_STATUS_ABRT	(smbus->base + 0x3c)	/* register used to
  							   check the status of
  							   the abort command */
  #define NVIDIA_SMB_CTRL		(smbus->base + 0x3e)	/* control register */
  
  #define NVIDIA_SMB_STATUS_ABRT_STS	0x01		/* Bit to notify that
  							   abort succeeded */
  #define NVIDIA_SMB_CTRL_ABORT	0x20
  #define NVIDIA_SMB_STS_DONE	0x80
  #define NVIDIA_SMB_STS_ALRM	0x40
  #define NVIDIA_SMB_STS_RES	0x20
  #define NVIDIA_SMB_STS_STATUS	0x1f
  
  #define NVIDIA_SMB_PRTCL_WRITE			0x00
  #define NVIDIA_SMB_PRTCL_READ			0x01
  #define NVIDIA_SMB_PRTCL_QUICK			0x02
  #define NVIDIA_SMB_PRTCL_BYTE			0x04
  #define NVIDIA_SMB_PRTCL_BYTE_DATA		0x06
  #define NVIDIA_SMB_PRTCL_WORD_DATA		0x08
  #define NVIDIA_SMB_PRTCL_BLOCK_DATA		0x0a
  #define NVIDIA_SMB_PRTCL_PEC			0x80
  
  /* Misc definitions */
  #define MAX_TIMEOUT	100
  
  /* We disable the second SMBus channel on these boards */
  static struct dmi_system_id __devinitdata nforce2_dmi_blacklist2[] = {
  	{
  		.ident = "DFI Lanparty NF4 Expert",
  		.matches = {
  			DMI_MATCH(DMI_BOARD_VENDOR, "DFI Corp,LTD"),
  			DMI_MATCH(DMI_BOARD_NAME, "LP UT NF4 Expert"),
  		},
  	},
  	{ }
  };
  
  static struct pci_driver nforce2_driver;
  
  /* For multiplexing support, we need a global reference to the 1st
     SMBus channel */
  #if defined CONFIG_I2C_NFORCE2_S4985 || defined CONFIG_I2C_NFORCE2_S4985_MODULE
  struct i2c_adapter *nforce2_smbus;
  EXPORT_SYMBOL_GPL(nforce2_smbus);
  
  static void nforce2_set_reference(struct i2c_adapter *adap)
  {
  	nforce2_smbus = adap;
  }
  #else
  static inline void nforce2_set_reference(struct i2c_adapter *adap) { }
  #endif
  
  static void nforce2_abort(struct i2c_adapter *adap)
  {
  	struct nforce2_smbus *smbus = adap->algo_data;
  	int timeout = 0;
  	unsigned char temp;
  
  	dev_dbg(&adap->dev, "Aborting current transaction\n");
  
  	outb_p(NVIDIA_SMB_CTRL_ABORT, NVIDIA_SMB_CTRL);
  	do {
  		msleep(1);
  		temp = inb_p(NVIDIA_SMB_STATUS_ABRT);
  	} while (!(temp & NVIDIA_SMB_STATUS_ABRT_STS) &&
  			(timeout++ < MAX_TIMEOUT));
  	if (!(temp & NVIDIA_SMB_STATUS_ABRT_STS))
  		dev_err(&adap->dev, "Can't reset the smbus\n");
  	outb_p(NVIDIA_SMB_STATUS_ABRT_STS, NVIDIA_SMB_STATUS_ABRT);
  }
  
  static int nforce2_check_status(struct i2c_adapter *adap)
  {
  	struct nforce2_smbus *smbus = adap->algo_data;
  	int timeout = 0;
  	unsigned char temp;
  
  	do {
  		msleep(1);
  		temp = inb_p(NVIDIA_SMB_STS);
  	} while ((!temp) && (timeout++ < MAX_TIMEOUT));
  
  	if (timeout > MAX_TIMEOUT) {
  		dev_dbg(&adap->dev, "SMBus Timeout!\n");
  		if (smbus->can_abort)
  			nforce2_abort(adap);
  		return -ETIMEDOUT;
  	}
  	if (!(temp & NVIDIA_SMB_STS_DONE) || (temp & NVIDIA_SMB_STS_STATUS)) {
  		dev_dbg(&adap->dev, "Transaction failed (0x%02x)!\n", temp);
  		return -EIO;
  	}
  	return 0;
  }
  
  /* Return negative errno on error */
  static s32 nforce2_access(struct i2c_adapter * adap, u16 addr,
  		unsigned short flags, char read_write,
  		u8 command, int size, union i2c_smbus_data * data)
  {
  	struct nforce2_smbus *smbus = adap->algo_data;
  	unsigned char protocol, pec;
  	u8 len;
  	int i, status;
  
  	protocol = (read_write == I2C_SMBUS_READ) ? NVIDIA_SMB_PRTCL_READ :
  		NVIDIA_SMB_PRTCL_WRITE;
  	pec = (flags & I2C_CLIENT_PEC) ? NVIDIA_SMB_PRTCL_PEC : 0;
  
  	switch (size) {
  
  		case I2C_SMBUS_QUICK:
  			protocol |= NVIDIA_SMB_PRTCL_QUICK;
  			read_write = I2C_SMBUS_WRITE;
  			break;
  
  		case I2C_SMBUS_BYTE:
  			if (read_write == I2C_SMBUS_WRITE)
  				outb_p(command, NVIDIA_SMB_CMD);
  			protocol |= NVIDIA_SMB_PRTCL_BYTE;
  			break;
  
  		case I2C_SMBUS_BYTE_DATA:
  			outb_p(command, NVIDIA_SMB_CMD);
  			if (read_write == I2C_SMBUS_WRITE)
  				outb_p(data->byte, NVIDIA_SMB_DATA);
  			protocol |= NVIDIA_SMB_PRTCL_BYTE_DATA;
  			break;
  
  		case I2C_SMBUS_WORD_DATA:
  			outb_p(command, NVIDIA_SMB_CMD);
  			if (read_write == I2C_SMBUS_WRITE) {
  				 outb_p(data->word, NVIDIA_SMB_DATA);
  				 outb_p(data->word >> 8, NVIDIA_SMB_DATA+1);
  			}
  			protocol |= NVIDIA_SMB_PRTCL_WORD_DATA | pec;
  			break;
  
  		case I2C_SMBUS_BLOCK_DATA:
  			outb_p(command, NVIDIA_SMB_CMD);
  			if (read_write == I2C_SMBUS_WRITE) {
  				len = data->block[0];
  				if ((len == 0) || (len > I2C_SMBUS_BLOCK_MAX)) {
  					dev_err(&adap->dev,
  						"Transaction failed "
  						"(requested block size: %d)\n",
  						len);
  					return -EINVAL;
  				}
  				outb_p(len, NVIDIA_SMB_BCNT);
  				for (i = 0; i < I2C_SMBUS_BLOCK_MAX; i++)
  					outb_p(data->block[i + 1],
  					       NVIDIA_SMB_DATA+i);
  			}
  			protocol |= NVIDIA_SMB_PRTCL_BLOCK_DATA | pec;
  			break;
  
  		default:
  			dev_err(&adap->dev, "Unsupported transaction %d\n", size);
  			return -EOPNOTSUPP;
  	}
  
  	outb_p((addr & 0x7f) << 1, NVIDIA_SMB_ADDR);
  	outb_p(protocol, NVIDIA_SMB_PRTCL);
  
  	status = nforce2_check_status(adap);
  	if (status)
  		return status;
  
  	if (read_write == I2C_SMBUS_WRITE)
  		return 0;
  
  	switch (size) {
  
  		case I2C_SMBUS_BYTE:
  		case I2C_SMBUS_BYTE_DATA:
  			data->byte = inb_p(NVIDIA_SMB_DATA);
  			break;
  
  		case I2C_SMBUS_WORD_DATA:
  			data->word = inb_p(NVIDIA_SMB_DATA) | (inb_p(NVIDIA_SMB_DATA+1) << 8);
  			break;
  
  		case I2C_SMBUS_BLOCK_DATA:
  			len = inb_p(NVIDIA_SMB_BCNT);
  			if ((len <= 0) || (len > I2C_SMBUS_BLOCK_MAX)) {
  				dev_err(&adap->dev, "Transaction failed "
  					"(received block size: 0x%02x)\n",
  					len);
  				return -EPROTO;
  			}
  			for (i = 0; i < len; i++)
  				data->block[i+1] = inb_p(NVIDIA_SMB_DATA + i);
  			data->block[0] = len;
  			break;
  	}
  
  	return 0;
  }
  
  
  static u32 nforce2_func(struct i2c_adapter *adapter)
  {
  	/* other functionality might be possible, but is not tested */
  	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
  	       I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
  	       I2C_FUNC_SMBUS_PEC |
  	       (((struct nforce2_smbus*)adapter->algo_data)->blockops ?
  		I2C_FUNC_SMBUS_BLOCK_DATA : 0);
  }
  
  static struct i2c_algorithm smbus_algorithm = {
  	.smbus_xfer	= nforce2_access,
  	.functionality	= nforce2_func,
  };
  
  
  static const struct pci_device_id nforce2_ids[] = {
  	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE2_SMBUS) },
  	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE2S_SMBUS) },
  	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE3_SMBUS) },
  	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE3S_SMBUS) },
  	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE4_SMBUS) },
  	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP04_SMBUS) },
  	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP51_SMBUS) },
  	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP55_SMBUS) },
  	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP61_SMBUS) },
  	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP65_SMBUS) },
  	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP67_SMBUS) },
  	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP73_SMBUS) },
  	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP78S_SMBUS) },
  	{ PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP79_SMBUS) },
  	{ 0 }
  };
  
  MODULE_DEVICE_TABLE (pci, nforce2_ids);
  
  
  static int __devinit nforce2_probe_smb (struct pci_dev *dev, int bar,
  	int alt_reg, struct nforce2_smbus *smbus, const char *name)
  {
  	int error;
  
  	smbus->base = pci_resource_start(dev, bar);
  	if (smbus->base) {
  		smbus->size = pci_resource_len(dev, bar);
  	} else {
  		/* Older incarnations of the device used non-standard BARs */
  		u16 iobase;
  
  		if (pci_read_config_word(dev, alt_reg, &iobase)
  		    != PCIBIOS_SUCCESSFUL) {
  			dev_err(&dev->dev, "Error reading PCI config for %s\n",
  				name);
  			return -EIO;
  		}
  
  		smbus->base = iobase & PCI_BASE_ADDRESS_IO_MASK;
  		smbus->size = 64;
  	}
  
  	error = acpi_check_region(smbus->base, smbus->size,
  				  nforce2_driver.name);
  	if (error)
  		return -1;
  
  	if (!request_region(smbus->base, smbus->size, nforce2_driver.name)) {
  		dev_err(&smbus->adapter.dev, "Error requesting region %02x .. %02X for %s\n",
  			smbus->base, smbus->base+smbus->size-1, name);
  		return -EBUSY;
  	}
  	smbus->adapter.owner = THIS_MODULE;
  	smbus->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
  	smbus->adapter.algo = &smbus_algorithm;
  	smbus->adapter.algo_data = smbus;
  	smbus->adapter.dev.parent = &dev->dev;
  	snprintf(smbus->adapter.name, sizeof(smbus->adapter.name),
  		"SMBus nForce2 adapter at %04x", smbus->base);
  
  	error = i2c_add_adapter(&smbus->adapter);
  	if (error) {
  		dev_err(&smbus->adapter.dev, "Failed to register adapter.\n");
  		release_region(smbus->base, smbus->size);
  		return error;
  	}
  	dev_info(&smbus->adapter.dev, "nForce2 SMBus adapter at %#x\n", smbus->base);
  	return 0;
  }
  
  
  static int __devinit nforce2_probe(struct pci_dev *dev, const struct pci_device_id *id)
  {
  	struct nforce2_smbus *smbuses;
  	int res1, res2;
  
  	/* we support 2 SMBus adapters */
  	if (!(smbuses = kzalloc(2*sizeof(struct nforce2_smbus), GFP_KERNEL)))
  		return -ENOMEM;
  	pci_set_drvdata(dev, smbuses);
  
  	switch(dev->device) {
  	case PCI_DEVICE_ID_NVIDIA_NFORCE2_SMBUS:
  	case PCI_DEVICE_ID_NVIDIA_NFORCE_MCP51_SMBUS:
  	case PCI_DEVICE_ID_NVIDIA_NFORCE_MCP55_SMBUS:
  		smbuses[0].blockops = 1;
  		smbuses[1].blockops = 1;
  		smbuses[0].can_abort = 1;
  		smbuses[1].can_abort = 1;
  	}
  
  	/* SMBus adapter 1 */
  	res1 = nforce2_probe_smb(dev, 4, NFORCE_PCI_SMB1, &smbuses[0], "SMB1");
  	if (res1 < 0)
  		smbuses[0].base = 0;	/* to have a check value */
  
  	/* SMBus adapter 2 */
  	if (dmi_check_system(nforce2_dmi_blacklist2)) {
  		dev_err(&dev->dev, "Disabling SMB2 for safety reasons.\n");
  		res2 = -EPERM;
  		smbuses[1].base = 0;
  	} else {
  		res2 = nforce2_probe_smb(dev, 5, NFORCE_PCI_SMB2, &smbuses[1],
  					 "SMB2");
  		if (res2 < 0)
  			smbuses[1].base = 0;	/* to have a check value */
  	}
  
  	if ((res1 < 0) && (res2 < 0)) {
  		/* we did not find even one of the SMBuses, so we give up */
  		kfree(smbuses);
  		return -ENODEV;
  	}
  
  	nforce2_set_reference(&smbuses[0].adapter);
  	return 0;
  }
  
  
  static void __devexit nforce2_remove(struct pci_dev *dev)
  {
  	struct nforce2_smbus *smbuses = (void*) pci_get_drvdata(dev);
  
  	nforce2_set_reference(NULL);
  	if (smbuses[0].base) {
  		i2c_del_adapter(&smbuses[0].adapter);
  		release_region(smbuses[0].base, smbuses[0].size);
  	}
  	if (smbuses[1].base) {
  		i2c_del_adapter(&smbuses[1].adapter);
  		release_region(smbuses[1].base, smbuses[1].size);
  	}
  	kfree(smbuses);
  }
  
  static struct pci_driver nforce2_driver = {
  	.name		= "nForce2_smbus",
  	.id_table	= nforce2_ids,
  	.probe		= nforce2_probe,
  	.remove		= __devexit_p(nforce2_remove),
  };
  
  static int __init nforce2_init(void)
  {
  	return pci_register_driver(&nforce2_driver);
  }
  
  static void __exit nforce2_exit(void)
  {
  	pci_unregister_driver(&nforce2_driver);
  }
  
  module_init(nforce2_init);
  module_exit(nforce2_exit);
  