v4.19.13 snapshot.
diff --git a/drivers/i2c/busses/i2c-viapro.c b/drivers/i2c/busses/i2c-viapro.c
new file mode 100644
index 0000000..0dc45e1
--- /dev/null
+++ b/drivers/i2c/busses/i2c-viapro.c
@@ -0,0 +1,507 @@
+/*
+    Copyright (c) 1998 - 2002  Frodo Looijaard <frodol@dds.nl>,
+    Philip Edelbrock <phil@netroedge.com>, Kyösti Mälkki <kmalkki@cc.hut.fi>,
+    Mark D. Studebaker <mdsxyz123@yahoo.com>
+    Copyright (C) 2005 - 2008  Jean Delvare <jdelvare@suse.de>
+
+    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 the following VIA south bridges:
+
+   Chip name          PCI ID  REV     I2C block
+   VT82C596A          0x3050             no
+   VT82C596B          0x3051             no
+   VT82C686A          0x3057  0x30       no
+   VT82C686B          0x3057  0x40       yes
+   VT8231             0x8235             no?
+   VT8233             0x3074             yes
+   VT8233A            0x3147             yes?
+   VT8235             0x3177             yes
+   VT8237R            0x3227             yes
+   VT8237A            0x3337             yes
+   VT8237S            0x3372             yes
+   VT8251             0x3287             yes
+   CX700              0x8324             yes
+   VX800/VX820        0x8353             yes
+   VX855/VX875        0x8409             yes
+
+   Note: we assume there can only be one device, with one SMBus interface.
+*/
+
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/pci.h>
+#include <linux/kernel.h>
+#include <linux/stddef.h>
+#include <linux/ioport.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/acpi.h>
+#include <linux/io.h>
+
+static struct pci_dev *vt596_pdev;
+
+#define SMBBA1		0x90
+#define SMBBA2		0x80
+#define SMBBA3		0xD0
+
+/* SMBus address offsets */
+static unsigned short vt596_smba;
+#define SMBHSTSTS	(vt596_smba + 0)
+#define SMBHSTCNT	(vt596_smba + 2)
+#define SMBHSTCMD	(vt596_smba + 3)
+#define SMBHSTADD	(vt596_smba + 4)
+#define SMBHSTDAT0	(vt596_smba + 5)
+#define SMBHSTDAT1	(vt596_smba + 6)
+#define SMBBLKDAT	(vt596_smba + 7)
+
+/* PCI Address Constants */
+
+/* SMBus data in configuration space can be found in two places,
+   We try to select the better one */
+
+static unsigned short SMBHSTCFG = 0xD2;
+
+/* Other settings */
+#define MAX_TIMEOUT	500
+
+/* VT82C596 constants */
+#define VT596_QUICK		0x00
+#define VT596_BYTE		0x04
+#define VT596_BYTE_DATA		0x08
+#define VT596_WORD_DATA		0x0C
+#define VT596_PROC_CALL		0x10
+#define VT596_BLOCK_DATA	0x14
+#define VT596_I2C_BLOCK_DATA	0x34
+
+
+/* If force is set to anything different from 0, we forcibly enable the
+   VT596. DANGEROUS! */
+static bool force;
+module_param(force, bool, 0);
+MODULE_PARM_DESC(force, "Forcibly enable the SMBus. DANGEROUS!");
+
+/* If force_addr is set to anything different from 0, we forcibly enable
+   the VT596 at the given address. VERY DANGEROUS! */
+static u16 force_addr;
+module_param_hw(force_addr, ushort, ioport, 0);
+MODULE_PARM_DESC(force_addr,
+		 "Forcibly enable the SMBus at the given address. "
+		 "EXTREMELY DANGEROUS!");
+
+
+static struct pci_driver vt596_driver;
+static struct i2c_adapter vt596_adapter;
+
+#define FEATURE_I2CBLOCK	(1<<0)
+static unsigned int vt596_features;
+
+#ifdef DEBUG
+static void vt596_dump_regs(const char *msg, u8 size)
+{
+	dev_dbg(&vt596_adapter.dev, "%s: STS=%02x CNT=%02x CMD=%02x ADD=%02x "
+		"DAT=%02x,%02x\n", msg, inb_p(SMBHSTSTS), inb_p(SMBHSTCNT),
+		inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
+		inb_p(SMBHSTDAT1));
+
+	if (size == VT596_BLOCK_DATA
+	 || size == VT596_I2C_BLOCK_DATA) {
+		int i;
+
+		dev_dbg(&vt596_adapter.dev, "BLK=");
+		for (i = 0; i < I2C_SMBUS_BLOCK_MAX / 2; i++)
+			printk("%02x,", inb_p(SMBBLKDAT));
+		printk("\n");
+		dev_dbg(&vt596_adapter.dev, "    ");
+		for (; i < I2C_SMBUS_BLOCK_MAX - 1; i++)
+			printk("%02x,", inb_p(SMBBLKDAT));
+		printk("%02x\n", inb_p(SMBBLKDAT));
+	}
+}
+#else
+static inline void vt596_dump_regs(const char *msg, u8 size) { }
+#endif
+
+/* Return -1 on error, 0 on success */
+static int vt596_transaction(u8 size)
+{
+	int temp;
+	int result = 0;
+	int timeout = 0;
+
+	vt596_dump_regs("Transaction (pre)", size);
+
+	/* Make sure the SMBus host is ready to start transmitting */
+	if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
+		dev_dbg(&vt596_adapter.dev, "SMBus busy (0x%02x). "
+			"Resetting...\n", temp);
+
+		outb_p(temp, SMBHSTSTS);
+		if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
+			dev_err(&vt596_adapter.dev, "SMBus reset failed! "
+				"(0x%02x)\n", temp);
+			return -EBUSY;
+		}
+	}
+
+	/* Start the transaction by setting bit 6 */
+	outb_p(0x40 | size, SMBHSTCNT);
+
+	/* We will always wait for a fraction of a second */
+	do {
+		msleep(1);
+		temp = inb_p(SMBHSTSTS);
+	} while ((temp & 0x01) && (++timeout < MAX_TIMEOUT));
+
+	/* If the SMBus is still busy, we give up */
+	if (timeout == MAX_TIMEOUT) {
+		result = -ETIMEDOUT;
+		dev_err(&vt596_adapter.dev, "SMBus timeout!\n");
+	}
+
+	if (temp & 0x10) {
+		result = -EIO;
+		dev_err(&vt596_adapter.dev, "Transaction failed (0x%02x)\n",
+			size);
+	}
+
+	if (temp & 0x08) {
+		result = -EIO;
+		dev_err(&vt596_adapter.dev, "SMBus collision!\n");
+	}
+
+	if (temp & 0x04) {
+		result = -ENXIO;
+		dev_dbg(&vt596_adapter.dev, "No response\n");
+	}
+
+	/* Resetting status register */
+	if (temp & 0x1F)
+		outb_p(temp, SMBHSTSTS);
+
+	vt596_dump_regs("Transaction (post)", size);
+
+	return result;
+}
+
+/* Return negative errno on error, 0 on success */
+static s32 vt596_access(struct i2c_adapter *adap, u16 addr,
+		unsigned short flags, char read_write, u8 command,
+		int size, union i2c_smbus_data *data)
+{
+	int i;
+	int status;
+
+	switch (size) {
+	case I2C_SMBUS_QUICK:
+		size = VT596_QUICK;
+		break;
+	case I2C_SMBUS_BYTE:
+		if (read_write == I2C_SMBUS_WRITE)
+			outb_p(command, SMBHSTCMD);
+		size = VT596_BYTE;
+		break;
+	case I2C_SMBUS_BYTE_DATA:
+		outb_p(command, SMBHSTCMD);
+		if (read_write == I2C_SMBUS_WRITE)
+			outb_p(data->byte, SMBHSTDAT0);
+		size = VT596_BYTE_DATA;
+		break;
+	case I2C_SMBUS_WORD_DATA:
+		outb_p(command, SMBHSTCMD);
+		if (read_write == I2C_SMBUS_WRITE) {
+			outb_p(data->word & 0xff, SMBHSTDAT0);
+			outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
+		}
+		size = VT596_WORD_DATA;
+		break;
+	case I2C_SMBUS_PROC_CALL:
+		outb_p(command, SMBHSTCMD);
+		outb_p(data->word & 0xff, SMBHSTDAT0);
+		outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
+		size = VT596_PROC_CALL;
+		break;
+	case I2C_SMBUS_I2C_BLOCK_DATA:
+		if (!(vt596_features & FEATURE_I2CBLOCK))
+			goto exit_unsupported;
+		if (read_write == I2C_SMBUS_READ)
+			outb_p(data->block[0], SMBHSTDAT0);
+		/* Fall through */
+	case I2C_SMBUS_BLOCK_DATA:
+		outb_p(command, SMBHSTCMD);
+		if (read_write == I2C_SMBUS_WRITE) {
+			u8 len = data->block[0];
+			if (len > I2C_SMBUS_BLOCK_MAX)
+				len = I2C_SMBUS_BLOCK_MAX;
+			outb_p(len, SMBHSTDAT0);
+			inb_p(SMBHSTCNT);	/* Reset SMBBLKDAT */
+			for (i = 1; i <= len; i++)
+				outb_p(data->block[i], SMBBLKDAT);
+		}
+		size = (size == I2C_SMBUS_I2C_BLOCK_DATA) ?
+		       VT596_I2C_BLOCK_DATA : VT596_BLOCK_DATA;
+		break;
+	default:
+		goto exit_unsupported;
+	}
+
+	outb_p(((addr & 0x7f) << 1) | read_write, SMBHSTADD);
+
+	status = vt596_transaction(size);
+	if (status)
+		return status;
+
+	if (size == VT596_PROC_CALL)
+		read_write = I2C_SMBUS_READ;
+
+	if ((read_write == I2C_SMBUS_WRITE) || (size == VT596_QUICK))
+		return 0;
+
+	switch (size) {
+	case VT596_BYTE:
+	case VT596_BYTE_DATA:
+		data->byte = inb_p(SMBHSTDAT0);
+		break;
+	case VT596_WORD_DATA:
+	case VT596_PROC_CALL:
+		data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
+		break;
+	case VT596_I2C_BLOCK_DATA:
+	case VT596_BLOCK_DATA:
+		data->block[0] = inb_p(SMBHSTDAT0);
+		if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
+			data->block[0] = I2C_SMBUS_BLOCK_MAX;
+		inb_p(SMBHSTCNT);	/* Reset SMBBLKDAT */
+		for (i = 1; i <= data->block[0]; i++)
+			data->block[i] = inb_p(SMBBLKDAT);
+		break;
+	}
+	return 0;
+
+exit_unsupported:
+	dev_warn(&vt596_adapter.dev, "Unsupported transaction %d\n",
+		 size);
+	return -EOPNOTSUPP;
+}
+
+static u32 vt596_func(struct i2c_adapter *adapter)
+{
+	u32 func = I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
+	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
+	    I2C_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_BLOCK_DATA;
+
+	if (vt596_features & FEATURE_I2CBLOCK)
+		func |= I2C_FUNC_SMBUS_I2C_BLOCK;
+	return func;
+}
+
+static const struct i2c_algorithm smbus_algorithm = {
+	.smbus_xfer	= vt596_access,
+	.functionality	= vt596_func,
+};
+
+static struct i2c_adapter vt596_adapter = {
+	.owner		= THIS_MODULE,
+	.class		= I2C_CLASS_HWMON | I2C_CLASS_SPD,
+	.algo		= &smbus_algorithm,
+};
+
+static int vt596_probe(struct pci_dev *pdev,
+		       const struct pci_device_id *id)
+{
+	unsigned char temp;
+	int error;
+
+	/* Determine the address of the SMBus areas */
+	if (force_addr) {
+		vt596_smba = force_addr & 0xfff0;
+		force = 0;
+		goto found;
+	}
+
+	if ((pci_read_config_word(pdev, id->driver_data, &vt596_smba)) ||
+	    !(vt596_smba & 0x0001)) {
+		/* try 2nd address and config reg. for 596 */
+		if (id->device == PCI_DEVICE_ID_VIA_82C596_3 &&
+		    !pci_read_config_word(pdev, SMBBA2, &vt596_smba) &&
+		    (vt596_smba & 0x0001)) {
+			SMBHSTCFG = 0x84;
+		} else {
+			/* no matches at all */
+			dev_err(&pdev->dev, "Cannot configure "
+				"SMBus I/O Base address\n");
+			return -ENODEV;
+		}
+	}
+
+	vt596_smba &= 0xfff0;
+	if (vt596_smba == 0) {
+		dev_err(&pdev->dev, "SMBus base address "
+			"uninitialized - upgrade BIOS or use "
+			"force_addr=0xaddr\n");
+		return -ENODEV;
+	}
+
+found:
+	error = acpi_check_region(vt596_smba, 8, vt596_driver.name);
+	if (error)
+		return -ENODEV;
+
+	if (!request_region(vt596_smba, 8, vt596_driver.name)) {
+		dev_err(&pdev->dev, "SMBus region 0x%x already in use!\n",
+			vt596_smba);
+		return -ENODEV;
+	}
+
+	pci_read_config_byte(pdev, SMBHSTCFG, &temp);
+	/* If force_addr is set, we program the new address here. Just to make
+	   sure, we disable the VT596 first. */
+	if (force_addr) {
+		pci_write_config_byte(pdev, SMBHSTCFG, temp & 0xfe);
+		pci_write_config_word(pdev, id->driver_data, vt596_smba);
+		pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01);
+		dev_warn(&pdev->dev, "WARNING: SMBus interface set to new "
+			 "address 0x%04x!\n", vt596_smba);
+	} else if (!(temp & 0x01)) {
+		if (force) {
+			/* 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(pdev, SMBHSTCFG, temp | 0x01);
+			dev_info(&pdev->dev, "Enabling SMBus device\n");
+		} else {
+			dev_err(&pdev->dev, "SMBUS: Error: Host SMBus "
+				"controller not enabled! - upgrade BIOS or "
+				"use force=1\n");
+			error = -ENODEV;
+			goto release_region;
+		}
+	}
+
+	dev_dbg(&pdev->dev, "VT596_smba = 0x%X\n", vt596_smba);
+
+	switch (pdev->device) {
+	case PCI_DEVICE_ID_VIA_CX700:
+	case PCI_DEVICE_ID_VIA_VX800:
+	case PCI_DEVICE_ID_VIA_VX855:
+	case PCI_DEVICE_ID_VIA_VX900:
+	case PCI_DEVICE_ID_VIA_8251:
+	case PCI_DEVICE_ID_VIA_8237:
+	case PCI_DEVICE_ID_VIA_8237A:
+	case PCI_DEVICE_ID_VIA_8237S:
+	case PCI_DEVICE_ID_VIA_8235:
+	case PCI_DEVICE_ID_VIA_8233A:
+	case PCI_DEVICE_ID_VIA_8233_0:
+		vt596_features |= FEATURE_I2CBLOCK;
+		break;
+	case PCI_DEVICE_ID_VIA_82C686_4:
+		/* The VT82C686B (rev 0x40) does support I2C block
+		   transactions, but the VT82C686A (rev 0x30) doesn't */
+		if (pdev->revision >= 0x40)
+			vt596_features |= FEATURE_I2CBLOCK;
+		break;
+	}
+
+	vt596_adapter.dev.parent = &pdev->dev;
+	snprintf(vt596_adapter.name, sizeof(vt596_adapter.name),
+		 "SMBus Via Pro adapter at %04x", vt596_smba);
+
+	vt596_pdev = pci_dev_get(pdev);
+	error = i2c_add_adapter(&vt596_adapter);
+	if (error) {
+		pci_dev_put(vt596_pdev);
+		vt596_pdev = NULL;
+		goto release_region;
+	}
+
+	/* Always return failure here.  This is to allow other drivers to bind
+	 * to this pci device.  We don't really want to have control over the
+	 * pci device, we only wanted to read as few register values from it.
+	 */
+	return -ENODEV;
+
+release_region:
+	release_region(vt596_smba, 8);
+	return error;
+}
+
+static const struct pci_device_id vt596_ids[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596_3),
+	  .driver_data = SMBBA1 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596B_3),
+	  .driver_data = SMBBA1 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C686_4),
+	  .driver_data = SMBBA1 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233_0),
+	  .driver_data = SMBBA3 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233A),
+	  .driver_data = SMBBA3 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8235),
+	  .driver_data = SMBBA3 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237),
+	  .driver_data = SMBBA3 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237A),
+	  .driver_data = SMBBA3 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237S),
+	  .driver_data = SMBBA3 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8231_4),
+	  .driver_data = SMBBA1 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8251),
+	  .driver_data = SMBBA3 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_CX700),
+	  .driver_data = SMBBA3 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX800),
+	  .driver_data = SMBBA3 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX855),
+	  .driver_data = SMBBA3 },
+	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX900),
+	  .driver_data = SMBBA3 },
+	{ 0, }
+};
+
+MODULE_DEVICE_TABLE(pci, vt596_ids);
+
+static struct pci_driver vt596_driver = {
+	.name		= "vt596_smbus",
+	.id_table	= vt596_ids,
+	.probe		= vt596_probe,
+};
+
+static int __init i2c_vt596_init(void)
+{
+	return pci_register_driver(&vt596_driver);
+}
+
+
+static void __exit i2c_vt596_exit(void)
+{
+	pci_unregister_driver(&vt596_driver);
+	if (vt596_pdev != NULL) {
+		i2c_del_adapter(&vt596_adapter);
+		release_region(vt596_smba, 8);
+		pci_dev_put(vt596_pdev);
+		vt596_pdev = NULL;
+	}
+}
+
+MODULE_AUTHOR("Kyosti Malkki <kmalkki@cc.hut.fi>, "
+	      "Mark D. Studebaker <mdsxyz123@yahoo.com> and "
+	      "Jean Delvare <jdelvare@suse.de>");
+MODULE_DESCRIPTION("vt82c596 SMBus driver");
+MODULE_LICENSE("GPL");
+
+module_init(i2c_vt596_init);
+module_exit(i2c_vt596_exit);