sb/intel/i82801gx: Autodisable functions based on devicetree

This removes the need to synchronize the devicetree and the romstage
writing to FD.

Change-Id: I83576599538a02d295fe00b35826f98d8c97d1cf
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/30244
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/southbridge/intel/i82801gx/i82801gx.c b/src/southbridge/intel/i82801gx/i82801gx.c
index eb0583f..a93d913 100644
--- a/src/southbridge/intel/i82801gx/i82801gx.c
+++ b/src/southbridge/intel/i82801gx/i82801gx.c
@@ -20,22 +20,86 @@
 #include "i82801gx.h"
 #include "sata.h"
 
+static void ich_hide_devfn(unsigned int devfn)
+{
+	switch (devfn) {
+	case PCI_DEVFN(27, 0): /* HD Audio Controller */
+		RCBA32_OR(FD, FD_HDAUD);
+		break;
+	case PCI_DEVFN(28, 0): /* PCI Express Root Port 1 */
+	case PCI_DEVFN(28, 1): /* PCI Express Root Port 2 */
+	case PCI_DEVFN(28, 2): /* PCI Express Root Port 3 */
+	case PCI_DEVFN(28, 3): /* PCI Express Root Port 4 */
+	case PCI_DEVFN(28, 4): /* PCI Express Root Port 5 */
+	case PCI_DEVFN(28, 5): /* PCI Express Root Port 6 */
+		RCBA32_OR(FD, ICH_DISABLE_PCIE(PCI_FUNC(devfn)));
+		break;
+	case PCI_DEVFN(29, 0): /* UHCI #1 */
+	case PCI_DEVFN(29, 1): /* UHCI #2 */
+	case PCI_DEVFN(29, 2): /* UHCI #3 */
+	case PCI_DEVFN(29, 3): /* UHCI #4 */
+		RCBA32_OR(FD, ICH_DISABLE_UHCI(PCI_FUNC(devfn)));
+		break;
+	case PCI_DEVFN(29, 7): /* EHCI #1 */
+		RCBA32_OR(FD, FD_EHCI);
+		break;
+	case PCI_DEVFN(30, 2): /* AC Audio */
+		RCBA32_OR(FD, FD_ACAUD);
+		break;
+	case PCI_DEVFN(30, 3): /* AC Modem */
+		RCBA32_OR(FD, FD_ACMOD);
+		break;
+	case PCI_DEVFN(31, 0): /* LPC */
+		RCBA32_OR(FD, FD_LPCB);
+		break;
+	case PCI_DEVFN(31, 1): /* PATA #1 */
+		RCBA32_OR(FD, FD_PATA);
+		break;
+	case PCI_DEVFN(31, 2): /* SATA #1 */
+		RCBA32_OR(FD, FD_SATA);
+		break;
+	case PCI_DEVFN(31, 3): /* SMBUS */
+		RCBA32_OR(FD, FD_SMBUS);
+		break;
+	}
+}
+
 void i82801gx_enable(struct device *dev)
 {
 	u32 reg32;
 
-	/* Enable SERR */
-	reg32 = pci_read_config32(dev, PCI_COMMAND);
-	reg32 |= PCI_COMMAND_SERR;
-	pci_write_config32(dev, PCI_COMMAND, reg32);
+	if (!dev->enabled) {
+		printk(BIOS_DEBUG, "%s: Disabling device\n",  dev_path(dev));
 
-	if (dev->path.pci.devfn == PCI_DEVFN(31, 2)) {
-		printk(BIOS_DEBUG, "Set SATA mode early\n");
-		sata_enable(dev);
+		/* Ensure memory, io, and bus master are all disabled */
+		reg32 = pci_read_config32(dev, PCI_COMMAND);
+		reg32 &= ~(PCI_COMMAND_MASTER |
+			   PCI_COMMAND_MEMORY | PCI_COMMAND_IO);
+		pci_write_config32(dev, PCI_COMMAND, reg32);
+
+		/* Hide this device if possible */
+		ich_hide_devfn(dev->path.pci.devfn);
+	} else {
+		/* Enable SERR */
+		reg32 = pci_read_config32(dev, PCI_COMMAND);
+		reg32 |= PCI_COMMAND_SERR;
+		pci_write_config32(dev, PCI_COMMAND, reg32);
+
+		if (dev->path.pci.devfn == PCI_DEVFN(31, 2)) {
+			printk(BIOS_DEBUG, "Set SATA mode early\n");
+			sata_enable(dev);
+		}
 	}
 }
 
+static void i82801gx_init(void *chip_info)
+{
+	/* Disable performance counter */
+	RCBA32_OR(FD, 1);
+}
+
 struct chip_operations southbridge_intel_i82801gx_ops = {
 	CHIP_NAME("Intel ICH7/ICH7-M (82801Gx) Series Southbridge")
-	.enable_dev = i82801gx_enable,
+	.enable_dev =	i82801gx_enable,
+	.init =		i82801gx_init,
 };
diff --git a/src/southbridge/intel/i82801gx/i82801gx.h b/src/southbridge/intel/i82801gx/i82801gx.h
index 29c8736..9fd9fd6 100644
--- a/src/southbridge/intel/i82801gx/i82801gx.h
+++ b/src/southbridge/intel/i82801gx/i82801gx.h
@@ -68,6 +68,8 @@
 #define   SEE	(1 << 1)
 #define   PERE	(1 << 0)
 
+#define ICH_PCIE_DEV_SLOT	28
+
 /* PCI Configuration Space (D31:F0): LPC */
 
 #define SERIRQ_CNTL		0x64
@@ -227,6 +229,13 @@
 #define RPC		0x0224	/* 32bit */
 #define RPFN		0x0238	/* 32bit */
 
+/* Get the function number assigned to a Root Port */
+#define RPFN_FNGET(reg, port)	(((reg) >> ((port) * 4)) & 7)
+/* Set the function number for a Root Port */
+#define RPFN_FNSET(port, func)	(((func) & 7) << ((port) * 4))
+/* Root Port function number mask */
+#define RPFN_FNMASK(port)	(7 << ((port) * 4))
+
 #define TRSR		0x1e00	/*  8bit */
 #define TRCR		0x1e10	/* 64bit */
 #define TWDR		0x1e18	/* 64bit */
@@ -269,16 +278,14 @@
 #define FD_PCIE3	(1 << 18)
 #define FD_PCIE2	(1 << 17)
 #define FD_PCIE1	(1 << 16)
+#define ICH_DISABLE_PCIE(x)	(1 << (16 + (x)))
 #define FD_EHCI		(1 << 15)
 #define FD_LPCB		(1 << 14)
 
 /* UHCI must be disabled from 4 downwards.
  * If UHCI controllers get disabled, EHCI
  * must know about it, too! */
-#define FD_UHCI4	(1 << 11)
-#define FD_UHCI34	((1 << 10) | FD_UHCI4)
-#define FD_UHCI234	((1 <<  9) | FD_UHCI3)
-#define FD_UHCI1234	((1 <<  8) | FD_UHCI2)
+#define ICH_DISABLE_UHCI(x)	(1 << (8 + (x)))
 
 #define FD_INTLAN	(1 <<  7)
 #define FD_ACMOD	(1 <<  6)