Round 2 of i82801AX fixes to get it into a usable shape.

[coreboot.git] / src / southbridge / intel / i82801ax / i82801ax.c

diff --git a/src/southbridge/intel/i82801ax/i82801ax.c b/src/southbridge/intel/i82801ax/i82801ax.c
index ea4cda67eb6e956feb183d698b8372c917fd53c5..7f4c7317c28df445efe177217067c7aa6bd77c16 100644 (file)
--- a/src/southbridge/intel/i82801ax/i82801ax.c
+++ b/src/southbridge/intel/i82801ax/i82801ax.c
@@ -27,38 +27,21 @@
 
 void i82801ax_enable(device_t dev)
 {
-       unsigned int index = 0;
-       uint16_t cur_disable_mask, new_disable_mask;
+       u16 reg16, index;
+       device_t lpc_dev;
 
-       /* All 82801xx devices should be on bus 0. */
-       unsigned int devfn = PCI_DEVFN(0x1f, 0);        // LPC
-       device_t lpc_dev = dev_find_slot(0, devfn);     // 0
+       /* Search for the 82801AA/AB LPC device (D31:F0) on PCI bus 0. */
+       lpc_dev = dev_find_slot(0, PCI_DEVFN(0x1f, 0));
        if (!lpc_dev)
                return;
 
-       /* We're going to assume, perhaps incorrectly, that if a function
-        * exists it can be disabled. Workarounds for ICH variants that don't
-        * follow this should be done by checking the device ID.
-        */
-       if (PCI_SLOT(dev->path.pci.devfn) == 31) {
-               index = PCI_FUNC(dev->path.pci.devfn);
-       } else if (PCI_SLOT(dev->path.pci.devfn) == 29) {
-               index = 8 + PCI_FUNC(dev->path.pci.devfn);
-       }
+       index = PCI_FUNC(dev->path.pci.devfn);
 
-       /* Function 0 is a bit of an exception. */
-       if (index == 0) {
-               index = 14;
-       }
-
-       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 desired. */
-       }
-       if (new_disable_mask != cur_disable_mask) {
-               pci_write_config16(lpc_dev, FUNC_DIS, new_disable_mask);
-       }
+       reg16 = pci_read_config16(lpc_dev, FUNC_DIS);
+       reg16 &= ~(1 << index);         /* Enable device. */
+       if (!dev->enabled)
+               reg16 |= (1 << index);  /* Disable device, if desired. */
+       pci_write_config16(lpc_dev, FUNC_DIS, reg16);
 }
 
 struct chip_operations southbridge_intel_i82801ax_ops = {