+/*
+ * Macbook7,1 firmware forcibly disables MCP89 AHCI and changes PCI ID when
+ * booting in BIOS compatibility mode. We restore the registers but not ID.
+ */
+static void ahci_mcp89_apple_enable(struct pci_dev *pdev)
+{
+ u32 val;
+
+ printk(KERN_INFO "ahci: enabling MCP89 AHCI mode\n");
+
+ pci_read_config_dword(pdev, 0xf8, &val);
+ val |= 1 << 0x1b;
+ /* the following changes the device ID, but appears not to affect function */
+ /* val = (val & ~0xf0000000) | 0x80000000; */
+ pci_write_config_dword(pdev, 0xf8, val);
+
+ pci_read_config_dword(pdev, 0x54c, &val);
+ val |= 1 << 0xc;
+ pci_write_config_dword(pdev, 0x54c, val);
+
+ pci_read_config_dword(pdev, 0x4a4, &val);
+ val &= 0xff;
+ val |= 0x01060100;
+ pci_write_config_dword(pdev, 0x4a4, val);
+
+ pci_read_config_dword(pdev, 0x54c, &val);
+ val &= ~(1 << 0xc);
+ pci_write_config_dword(pdev, 0x54c, val);
+
+ pci_read_config_dword(pdev, 0xf8, &val);
+ val &= ~(1 << 0x1b);
+ pci_write_config_dword(pdev, 0xf8, val);
+}
+
+static bool is_mcp89_apple(struct pci_dev *pdev)
+{
+ return pdev->vendor == PCI_VENDOR_ID_NVIDIA &&
+ pdev->device == PCI_DEVICE_ID_NVIDIA_NFORCE_MCP89_SATA &&
+ pdev->subsystem_vendor == PCI_VENDOR_ID_APPLE &&
+ pdev->subsystem_device == 0xcb89;
+}
+