From 7557331605ecdcff1276979948dc8c4daf3ed2c3 Mon Sep 17 00:00:00 2001
From: "Steven J. Magnani" <steve@digidescorp.com>
Date: Wed, 21 Sep 2005 13:49:44 +0000
Subject: Rewrite i82801dbm_enable to do nothing if device does not have an
 enable/disable bit.

git-svn-id: svn://svn.coreboot.org/coreboot/trunk@2041 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
---
 src/southbridge/intel/i82801dbm/i82801dbm.c | 87 ++++++++++++++++-------------
 1 file changed, 48 insertions(+), 39 deletions(-)

(limited to 'src/southbridge')

diff --git a/src/southbridge/intel/i82801dbm/i82801dbm.c b/src/southbridge/intel/i82801dbm/i82801dbm.c
index 29804dfbc5..1e49205f90 100644
--- a/src/southbridge/intel/i82801dbm/i82801dbm.c
+++ b/src/southbridge/intel/i82801dbm/i82801dbm.c
@@ -6,48 +6,57 @@
 
 void i82801dbm_enable(device_t dev)
 {
-	device_t lpc_dev;
-	unsigned int index;
-	uint16_t reg_old, reg;
-
-//	all 82801dbm device ares in bus 0
-	unsigned int devfn;
-	devfn = PCI_DEVFN(0x1f, 0); // lpc
-	lpc_dev = dev_find_slot(0, devfn); // 0
-	if (!lpc_dev ) {
+	unsigned int index = 0;
+	uint8_t bHasDisableBit = 0;
+	uint16_t cur_disable_mask, new_disable_mask;
+
+//	all 82801dbm devices are in bus 0
+	unsigned int devfn = PCI_DEVFN(0x1f, 0); // lpc
+	device_t lpc_dev = dev_find_slot(0, devfn); // 0
+	if (!lpc_dev)
 		return;
-	}
-#if 0
-	if ((lpc_dev->vendor != PCI_VENDOR_ID_INTEL) ||
-	    (lpc_dev->device != PCI_DEVICE_ID_INTEL_82801DBM_1F0)) {
-		uint32_t id;
-		id = pci_read_config32(lpc_dev, PCI_VENDOR_ID);
-		if (id != (PCI_VENDOR_ID_INTEL | (PCI_DEVICE_ID_INTEL_82801DBM_1F0 << 16))) {
-			return;
+
+	// Calculate disable bit position for specified device:function
+	// NOTE: For ICH-4, only the following devices can be disabled:
+	//		 D31: F0, F1, F3, F5, F6, 
+	//		 D29: F0, F1, F2, F7
+
+    if (PCI_SLOT(dev->path.u.pci.devfn) == 31) {
+    	index = PCI_FUNC(dev->path.u.pci.devfn);
+
+		switch (index) {
+			case 0:
+			case 1:
+			case 3:
+			case 5:
+			case 6:
+				bHasDisableBit = 1;
+				break;
+			
+			default:
+				break;
+		};
+		
+		if (index == 0)
+			index = 14;		// D31:F0 bit is an exception
+
+    } else if (PCI_SLOT(dev->path.u.pci.devfn) == 29) {
+    	index = 8 + PCI_FUNC(dev->path.u.pci.devfn);
+
+		if ((PCI_FUNC(dev->path.u.pci.devfn) < 3) || (PCI_FUNC(dev->path.u.pci.devfn) == 7))
+			bHasDisableBit = 1;
+    }
+
+	if (bHasDisableBit) {
+		cur_disable_mask = pci_read_config16(lpc_dev, FUNC_DIS);
+		new_disable_mask = cur_disable_mask & ~(1<<index); 		// enable it
+		if (!dev->enabled) {
+			new_disable_mask |= (1<<index);  // disable it
+		}
+		if (new_disable_mask != cur_disable_mask) {
+			pci_write_config16(lpc_dev, FUNC_DIS, new_disable_mask);
 		}
 	}
-#endif
-
-	index = (dev->path.u.pci.devfn & 7);
-        if((dev->path.u.pci.devfn & ~0x7)==devfn) { // D=0x1f
-                if(index==0){   //1f0   
-                        index = 14;
-                } 
-        } else { // D=0x1d
-                index += 8;
-        }
-
-	reg_old = pci_read_config16(lpc_dev, FUNC_DIS);
-	reg = reg_old;
-	reg &= ~(1<<index); // enable it
-	if (!dev->enabled) {
-		reg |= (1<<index);  // disable it
-	}
-	if (reg != reg_old) {
-		pci_write_config16(lpc_dev, FUNC_DIS, reg);
-	}
-	reg = pci_read_config16(lpc_dev, FUNC_DIS);
-
 }
 
 struct chip_operations southbridge_intel_i82801dbm_control = {
-- 
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