1 files changed, 72 insertions, 1 deletions

diff --git a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c
index 761f9dd53620..63d5e5978046 100644
--- a/drivers/i2c/busses/i2c-piix4.c
+++ b/drivers/i2c/busses/i2c-piix4.c
@@ -226,6 +226,70 @@ static int __devinit piix4_setup(struct pci_dev *PIIX4_dev,
         return 0;
 }
 
+static int __devinit piix4_setup_sb800(struct pci_dev *PIIX4_dev,
+                                const struct pci_device_id *id)
+{
+        unsigned short smba_idx = 0xcd6;
+        u8 smba_en_lo, smba_en_hi, i2ccfg, i2ccfg_offset = 0x10, smb_en = 0x2c;
+
+        /* SB800 SMBus does not support forcing address */
+        if (force || force_addr) {
+                dev_err(&PIIX4_dev->dev, "SB800 SMBus does not support "
+                        "forcing address!\n");
+                return -EINVAL;
+        }
+
+        /* Determine the address of the SMBus areas */
+        if (!request_region(smba_idx, 2, "smba_idx")) {
+                dev_err(&PIIX4_dev->dev, "SMBus base address index region "
+                        "0x%x already in use!\n", smba_idx);
+                return -EBUSY;
+        }
+        outb_p(smb_en, smba_idx);
+        smba_en_lo = inb_p(smba_idx + 1);
+        outb_p(smb_en + 1, smba_idx);
+        smba_en_hi = inb_p(smba_idx + 1);
+        release_region(smba_idx, 2);
+
+        if ((smba_en_lo & 1) == 0) {
+                dev_err(&PIIX4_dev->dev,
+                        "Host SMBus controller not enabled!\n");
+                return -ENODEV;
+        }
+
+        piix4_smba = ((smba_en_hi << 8) | smba_en_lo) & 0xffe0;
+        if (acpi_check_region(piix4_smba, SMBIOSIZE, piix4_driver.name))
+                return -EBUSY;
+
+        if (!request_region(piix4_smba, SMBIOSIZE, piix4_driver.name)) {
+                dev_err(&PIIX4_dev->dev, "SMBus region 0x%x already in use!\n",
+                        piix4_smba);
+                return -EBUSY;
+        }
+
+        /* Request the SMBus I2C bus config region */
+        if (!request_region(piix4_smba + i2ccfg_offset, 1, "i2ccfg")) {
+                dev_err(&PIIX4_dev->dev, "SMBus I2C bus config region "
+                        "0x%x already in use!\n", piix4_smba + i2ccfg_offset);
+                release_region(piix4_smba, SMBIOSIZE);
+                piix4_smba = 0;
+                return -EBUSY;
+        }
+        i2ccfg = inb_p(piix4_smba + i2ccfg_offset);
+        release_region(piix4_smba + i2ccfg_offset, 1);
+
+        if (i2ccfg & 1)
+                dev_dbg(&PIIX4_dev->dev, "Using IRQ for SMBus.\n");
+        else
+                dev_dbg(&PIIX4_dev->dev, "Using SMI# for SMBus.\n");
+
+        dev_info(&PIIX4_dev->dev,
+                 "SMBus Host Controller at 0x%x, revision %d\n",
+                 piix4_smba, i2ccfg >> 4);
+
+        return 0;
+}
+
 static int piix4_transaction(void)
 {
         int temp;
@@ -433,7 +497,14 @@ static int __devinit piix4_probe(struct pci_dev *dev,
 {
         int retval;
 
-        retval = piix4_setup(dev, id);
+        if ((dev->vendor == PCI_VENDOR_ID_ATI) &&
+            (dev->device == PCI_DEVICE_ID_ATI_SBX00_SMBUS) &&
+            (dev->revision >= 0x40))
+                /* base address location etc changed in SB800 */
+                retval = piix4_setup_sb800(dev, id);
+        else
+                retval = piix4_setup(dev, id);
+
         if (retval)
                 return retval;