[PATCH] Add support to SB800 SMBus changes

[shane.huang at amd.com (Shane Huang)]

This version of driver adds support for the AMD SB800 Family series of products.
Major changes include the changes to addressing the SMBUS registers at different
location from the locations in the previous compatible parts from AMD such as
SB400/SB600/SB700. For SB800, the main features and register definitions of
SMBUS and other interfaces are still compatible with the previous products with
the only change being in how to access the internal registers for these blocks
may differ.

Signed-off-by: Shane Huang <shane.huang at amd.com>

diff -ruN a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c
--- a/drivers/i2c/busses/i2c-piix4.c	2009-02-07 00:58:32.000000000 +0800
+++ b/drivers/i2c/busses/i2c-piix4.c	2009-02-11 14:28:37.000000000 +0800
@@ -130,11 +130,20 @@
 				const struct pci_device_id *id)
 {
 	unsigned char temp;
+	int sbx00_quirk = 0;
+	u8 sbx00_a = 0, sbx00_b = 0, sbx00_i2ccfg = 0;
 
 	if ((PIIX4_dev->vendor == PCI_VENDOR_ID_SERVERWORKS) &&
 	    (PIIX4_dev->device == PCI_DEVICE_ID_SERVERWORKS_CSB5))
 		srvrworks_csb5_delay = 1;
 
+	if ((PIIX4_dev->vendor == PCI_VENDOR_ID_ATI) &&
+	    (PIIX4_dev->device == PCI_DEVICE_ID_ATI_SBX00_SMBUS) &&
+	    (PIIX4_dev->revision >= 0x40)) {
+		dev_info(&PIIX4_dev->dev, "Apply SBX00 SMBus quirk.\n");
+		sbx00_quirk = 1;
+	}
+
 	/* On some motherboards, it was reported that accessing the SMBus
 	   caused severe hardware problems */
 	if (dmi_check_system(piix4_dmi_blacklist)) {
@@ -157,13 +166,24 @@
 		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 (sbx00_quirk) {
+			/* SBX00 base address location changed in some revs */
+			dev_dbg(&PIIX4_dev->dev, "SBX00 SMBus base address "
+				"location changed in some revisions!\n");
+			outb_p(0x2c, 0xcd6);
+			sbx00_a = inb_p(0xcd7);
+			outb_p(0x2d, 0xcd6);
+			sbx00_b = inb_p(0xcd7);
+			piix4_smba = ((sbx00_b << 8) | sbx00_a) & 0xffe0;
+		} 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;
+			}
 		}
 	}
 
@@ -176,7 +196,13 @@
 		return -EBUSY;
 	}
 
-	pci_read_config_byte(PIIX4_dev, SMBHSTCFG, &temp);
+	if (sbx00_quirk) {
+		/* Assemble the compatible value for some SBX00 revisions */
+		sbx00_i2ccfg = inb_p(piix4_smba + 0x10);
+		temp = ((sbx00_i2ccfg << 1) & 0x2) | (sbx00_a & 0x1);
+	} else {
+		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. */
@@ -218,7 +244,12 @@
 		dev_err(&PIIX4_dev->dev, "Illegal Interrupt configuration "
 			"(or code out of date)!\n");
 
-	pci_read_config_byte(PIIX4_dev, SMBREV, &temp);
+	if (sbx00_quirk)
+		/* Assemble the compatible value for some SBX00 revisions */
+		temp = (sbx00_i2ccfg >> 4) & 0x0f;
+	else
+		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);