AMD cimx/sb800: Fix PCI-to-PCI bridge 0:14.4 configuration

A set of pins can be configured for GPIO or (parallel) PCI bridge use.

When requested configuration is 0:14.4 enabled, register programming
must be done before attempting to enumerate devices behind the bridge.

When requested configuration is 0:14.4 disabled, we must not even
temporarily enable pins for PCI use to avoid spurious GPIO state changes.

As our PCI subsystem currently does not configure visible PCI bridges
that are marked disabled, we cannot mark 0:14.4 disabled just yet but
need to handle pcengines/apu1 as a special case.

Drop related dead code.

Change-Id: I8644ebae43b33121ef2a7ed30f745299716ce0df
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/8329
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>

4 files changed, 9 insertions, 57 deletions

diff --git a/src/mainboard/advansus/a785e-i/mainboard.c b/src/mainboard/advansus/a785e-i/mainboard.c
index 9b6450d09e..90d3342faa 100644
--- a/src/mainboard/advansus/a785e-i/mainboard.c
+++ b/src/mainboard/advansus/a785e-i/mainboard.c
@@ -37,10 +37,6 @@ void enable_int_gfx(void)
 {
 	volatile u8 *gpio_reg;
 
-#ifdef UNUSED_CODE
-	RWPMIO(SB_PMIOA_REGEA, AccWidthUint8, ~(BIT0), BIT0); /* Disable the PCIB */
-	RWPMIO(SB_PMIOA_REGF6, AccWidthUint8, ~(BIT0), BIT0); /* Disable Gec */
-#endif
 	/* make sure the Acpi MMIO(fed80000) is accessible */
         RWPMIO(SB_PMIOA_REG24, AccWidthUint8, ~(BIT0), BIT0);
 
diff --git a/src/mainboard/asus/m5a88-v/mainboard.c b/src/mainboard/asus/m5a88-v/mainboard.c
index 8ee338efc9..9be0ce99d2 100644
--- a/src/mainboard/asus/m5a88-v/mainboard.c
+++ b/src/mainboard/asus/m5a88-v/mainboard.c
@@ -37,10 +37,6 @@ void enable_int_gfx(void)
 {
 	volatile u8 *gpio_reg;
 
-#ifdef UNUSED_CODE
-	RWPMIO(SB_PMIOA_REGEA, AccWidthUint8, ~(BIT0), BIT0); /* Disable the PCIB */
-	RWPMIO(SB_PMIOA_REGF6, AccWidthuint8, ~(BIT0), BIT0); /* Disable Gec */
-#endif
 	/* make sure the MMIO(fed80000) is accessible */
 	RWPMIO(SB_PMIOA_REG24, AccWidthUint8, ~(BIT0), BIT0);
 
diff --git a/src/mainboard/avalue/eax-785e/mainboard.c b/src/mainboard/avalue/eax-785e/mainboard.c
index 6ce3469e78..0f5f7446a8 100644
--- a/src/mainboard/avalue/eax-785e/mainboard.c
+++ b/src/mainboard/avalue/eax-785e/mainboard.c
@@ -37,10 +37,6 @@ void enable_int_gfx(void)
 {
 	volatile u8 *gpio_reg;
 
-#ifdef UNUSED_CODE
-	RWPMIO(SB_PMIOA_REGEA, AccWidthUint8, ~(BIT0), BIT0); /* Disable the PCIB */
-	RWPMIO(SB_PMIOA_REGF6, AccWidthUint8, ~(BIT0), BIT0); /* Disable Gec */
-#endif
 	/* make sure the Acpi MMIO(fed80000) is accessible */
         RWPMIO(SB_PMIOA_REG24, AccWidthUint8, ~(BIT0), BIT0);
 
diff --git a/src/southbridge/amd/cimx/sb800/late.c b/src/southbridge/amd/cimx/sb800/late.c
index 747d3d63d6..19d7fb5379 100644
--- a/src/southbridge/amd/cimx/sb800/late.c
+++ b/src/southbridge/amd/cimx/sb800/late.c
@@ -260,51 +260,6 @@ static const struct pci_driver gec_driver __pci_driver = {
 };
 
 /**
- * @brief Enable PCI Bridge
- *
- * PcibConfig [PM_Reg: EAh], PCIDisable [Bit0]
- * 'PCIDisable' set to 0 to enable P2P bridge.
- * 'PCIDisable' set to 1 to disable P2P bridge and enable PCI interface pins
- *              to function as GPIO {GPIO 35:0}.
- */
-static void pci_init(device_t dev)
-{
-	/* PCI Bridge SHOULD be enabled by default according to SB800 rrg,
-	 * but actually was disabled in some platform, so I have to enabled it.
-	 */
-	RWMEM(ACPI_MMIO_BASE + PMIO_BASE + SB_PMIOA_REGEA, AccWidthUint8, ~BIT0, 0);
-}
-
-
-static struct device_operations pci_ops = {
-        .read_resources = pci_bus_read_resources,
-        .set_resources = pci_dev_set_resources,
-        .enable_resources = pci_bus_enable_resources,
-        .init = pci_init,
-        .scan_bus = pci_scan_bridge,
-        .reset_bus = pci_bus_reset,
-        .ops_pci = &lops_pci,
-};
-
-static const struct pci_driver pci_driver __pci_driver = {
-        .ops = &pci_ops,
-        .vendor = PCI_VENDOR_ID_ATI,
-        .device = PCI_DEVICE_ID_ATI_SB800_PCI,
-};
-
-
-struct device_operations bridge_ops = {
-	.read_resources   = pci_bus_read_resources,
-	.set_resources    = pci_dev_set_resources,
-	.enable_resources = pci_bus_enable_resources,
-	.init             = 0,
-	.scan_bus         = pci_scan_bridge,
-	.enable           = 0,
-	.reset_bus        = pci_bus_reset,
-	.ops_pci          = &lops_pci,
-};
-
-/**
  * South Bridge CIMx ramstage entry point wrapper.
  */
 void sb_Before_Pci_Init(void)
@@ -447,6 +402,15 @@ static void sb800_enable(device_t dev)
 		break;
 
 	case (0x14 << 3) | 4: /* 0:14:4 PCI */
+		/* PcibConfig [PM_Reg: EAh], PCIDisable [Bit0]
+		 * 'PCIDisable' set to 0 to enable P2P bridge.
+		 * 'PCIDisable' set to 1 to disable P2P bridge and enable PCI interface pins
+		 *              to function as GPIO {GPIO 35:0}.
+		 */
+		if (dev->enabled)
+			RWMEM(ACPI_MMIO_BASE + PMIO_BASE + SB_PMIOA_REGEA, AccWidthUint8, ~BIT0, 0);
+		else
+			RWMEM(ACPI_MMIO_BASE + PMIO_BASE + SB_PMIOA_REGEA, AccWidthUint8, ~BIT0, BIT0);
 		break;
 
 	case (0x14 << 3) | 6: /* 0:14:6 GEC */