diff --git a/arch/sh/drivers/pci/Makefile b/arch/sh/drivers/pci/Makefile
index 4a59e689087..82f0a335fd1 100644
--- a/arch/sh/drivers/pci/Makefile
+++ b/arch/sh/drivers/pci/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_SH_RTS7751R2D)		+= fixups-rts7751r2d.o
 obj-$(CONFIG_SH_SH03)			+= fixups-sh03.o
 obj-$(CONFIG_SH_HIGHLANDER)		+= fixups-r7780rp.o
 obj-$(CONFIG_SH_SH7785LCR)		+= fixups-r7780rp.o
+obj-$(CONFIG_SH_SDK7786)		+= fixups-sdk7786.o
 obj-$(CONFIG_SH_SDK7780)		+= fixups-sdk7780.o
 obj-$(CONFIG_SH_7780_SOLUTION_ENGINE)	+= fixups-sdk7780.o
 obj-$(CONFIG_SH_TITAN)			+= fixups-titan.o
diff --git a/arch/sh/drivers/pci/fixups-sdk7786.c b/arch/sh/drivers/pci/fixups-sdk7786.c
new file mode 100644
index 00000000000..058a65a1aa2
--- /dev/null
+++ b/arch/sh/drivers/pci/fixups-sdk7786.c
@@ -0,0 +1,68 @@
+/*
+ * SDK7786 FPGA PCIe mux handling
+ *
+ * Copyright (C) 2010  Paul Mundt
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#define pr_fmt(fmt) "PCI: " fmt
+
+#include <linux/init.h>
+#include <linux/clk.h>
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <mach/fpga.h>
+
+/*
+ * The SDK7786 FPGA supports mangling of most of the slots in some way or
+ * another. Slots 3/4 are special in that only one can be supported at a
+ * time, and both appear on port 3 to the PCI bus scan. Enabling slot 4
+ * (the horizontal edge connector) will disable slot 3 entirely.
+ *
+ * Misconfigurations can be detected through the FPGA via the slot
+ * resistors to determine card presence. Hotplug remains unsupported.
+ */
+static unsigned int slot4en __devinitdata;
+
+char *__devinit pcibios_setup(char *str)
+{
+	if (strcmp(str, "slot4en") == 0) {
+		slot4en = 1;
+		return NULL;
+	}
+
+	return str;
+}
+
+static int __init sdk7786_pci_init(void)
+{
+	u16 data = fpga_read_reg(PCIECR);
+
+	/*
+	 * Enable slot #4 if it's been specified on the command line.
+	 *
+	 * Optionally reroute if slot #4 has a card present while slot #3
+	 * does not, regardless of command line value.
+	 *
+	 * Card presence is logically inverted.
+	 */
+	slot4en ?: (!(data & PCIECR_PRST4) && (data & PCIECR_PRST3));
+	if (slot4en) {
+		pr_info("Activating PCIe slot#4 (disabling slot#3)\n");
+
+		data &= ~PCIECR_PCIEMUX1;
+		fpga_write_reg(data, PCIECR);
+
+		/* Warn about forced rerouting if slot#3 is occupied */
+		if ((data & PCIECR_PRST3) == 0) {
+			pr_warning("Unreachable card detected in slot#3\n");
+			return -EBUSY;
+		}
+	} else
+		pr_info("PCIe slot#4 disabled\n");
+
+	return 0;
+}
+postcore_initcall(sdk7786_pci_init);
diff --git a/arch/sh/drivers/pci/pci.c b/arch/sh/drivers/pci/pci.c
index af4191bbb17..60ee09a4e12 100644
--- a/arch/sh/drivers/pci/pci.c
+++ b/arch/sh/drivers/pci/pci.c
@@ -268,7 +268,7 @@ void __init pcibios_update_irq(struct pci_dev *dev, int irq)
 	pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq);
 }
 
-char * __devinit pcibios_setup(char *str)
+char * __devinit __weak pcibios_setup(char *str)
 {
 	return str;
 }
diff --git a/arch/sh/include/mach-sdk7786/mach/fpga.h b/arch/sh/include/mach-sdk7786/mach/fpga.h
index 416b621d94d..8cc784147b9 100644
--- a/arch/sh/include/mach-sdk7786/mach/fpga.h
+++ b/arch/sh/include/mach-sdk7786/mach/fpga.h
@@ -31,7 +31,16 @@
 #define EXTASR		0x110
 #define SPCAR		0x120
 #define INTMSR		0x130
+
 #define PCIECR		0x140
+#define  PCIECR_PCIEMUX1	BIT(15)
+#define  PCIECR_PCIEMUX0	BIT(14)
+#define  PCIECR_PRST4		BIT(12) /* slot 4 card present */
+#define  PCIECR_PRST3		BIT(11) /* slot 3 card present */
+#define  PCIECR_PRST2		BIT(10) /* slot 2 card present */
+#define  PCIECR_PRST1		BIT(9)  /* slot 1 card present */
+#define  PCIECR_CLKEN		BIT(4)
+
 #define FAER		0x150
 #define USRGPIR		0x160
 /* 0x170 reserved */