diff --git a/arch/arm/mach-iop32x/Kconfig b/arch/arm/mach-iop32x/Kconfig
index 9dd49cff21ff65a16d1b66f21fa5df75377827db..9bb02b6d7ae1622fbfb002fedc98bdfb9f1857fc 100644
--- a/arch/arm/mach-iop32x/Kconfig
+++ b/arch/arm/mach-iop32x/Kconfig
@@ -34,6 +34,14 @@ config MACH_N2100
 	  Say Y here if you want to run your kernel on the Thecus n2100
 	  NAS appliance.
 
+config IOP3XX_ATU
+        bool "Enable the PCI Controller"
+        default y
+        help
+          Say Y here if you want the IOP to initialize its PCI Controller.
+          Say N if the IOP is an add in card, the host system owns the PCI
+          bus in this case.
+
 endmenu
 
 endif
diff --git a/arch/arm/mach-iop32x/iq31244.c b/arch/arm/mach-iop32x/iq31244.c
index 60e74309a458853b80cdab4cd863fb46ba942aa8..7b21c6e13e59004c0244351b04d9312b91cac7a7 100644
--- a/arch/arm/mach-iop32x/iq31244.c
+++ b/arch/arm/mach-iop32x/iq31244.c
@@ -178,9 +178,10 @@ static struct hw_pci iq31244_pci __initdata = {
 
 static int __init iq31244_pci_init(void)
 {
-	if (is_ep80219())
-		pci_common_init(&ep80219_pci);
-	else if (machine_is_iq31244()) {
+	if (is_ep80219()) {
+		if (iop3xx_get_init_atu() == IOP3XX_INIT_ATU_ENABLE)
+			pci_common_init(&ep80219_pci);
+	} else if (machine_is_iq31244()) {
 		if (is_80219()) {
 			printk("note: iq31244 board type has been selected\n");
 			printk("note: to select ep80219 operation:\n");
@@ -189,7 +190,9 @@ static int __init iq31244_pci_init(void)
 			printk("\t2/ update boot loader to pass"
 				" the ep80219 id: %d\n", MACH_TYPE_EP80219);
 		}
-		pci_common_init(&iq31244_pci);
+
+		if (iop3xx_get_init_atu() == IOP3XX_INIT_ATU_ENABLE)
+			pci_common_init(&iq31244_pci);
 	}
 
 	return 0;
diff --git a/arch/arm/mach-iop32x/iq80321.c b/arch/arm/mach-iop32x/iq80321.c
index 361c70c0f64cfba07ee39d37f35bfdffeb052c9c..bc25fb91e7b971a07f74dfa4c1a23f5f5ecf4ef6 100644
--- a/arch/arm/mach-iop32x/iq80321.c
+++ b/arch/arm/mach-iop32x/iq80321.c
@@ -113,7 +113,8 @@ static struct hw_pci iq80321_pci __initdata = {
 
 static int __init iq80321_pci_init(void)
 {
-	if (machine_is_iq80321())
+	if ((iop3xx_get_init_atu() == IOP3XX_INIT_ATU_ENABLE) &&
+		machine_is_iq80321())
 		pci_common_init(&iq80321_pci);
 
 	return 0;
diff --git a/arch/arm/mach-iop33x/Kconfig b/arch/arm/mach-iop33x/Kconfig
index 9aa016bb18f9d1012b32d0a05ce320c7cbbe32d3..45598e09689859025143a233e5407194421d4715 100644
--- a/arch/arm/mach-iop33x/Kconfig
+++ b/arch/arm/mach-iop33x/Kconfig
@@ -16,6 +16,14 @@ config MACH_IQ80332
 	  Say Y here if you want to run your kernel on the Intel IQ80332
 	  evaluation kit for the IOP332 chipset.
 
+config IOP3XX_ATU
+	bool "Enable the PCI Controller"
+	default y
+	help
+	  Say Y here if you want the IOP to initialize its PCI Controller.
+	  Say N if the IOP is an add in card, the host system owns the PCI
+	  bus in this case.
+
 endmenu
 
 endif
diff --git a/arch/arm/mach-iop33x/iq80331.c b/arch/arm/mach-iop33x/iq80331.c
index 1a9e36138d8046ff9a7ccbc427852141100f794c..376c932830be1c631e55cf8773c0e795c19d00b4 100644
--- a/arch/arm/mach-iop33x/iq80331.c
+++ b/arch/arm/mach-iop33x/iq80331.c
@@ -96,7 +96,8 @@ static struct hw_pci iq80331_pci __initdata = {
 
 static int __init iq80331_pci_init(void)
 {
-	if (machine_is_iq80331())
+	if ((iop3xx_get_init_atu() == IOP3XX_INIT_ATU_ENABLE) &&
+		machine_is_iq80331())
 		pci_common_init(&iq80331_pci);
 
 	return 0;
diff --git a/arch/arm/mach-iop33x/iq80332.c b/arch/arm/mach-iop33x/iq80332.c
index 96d6f0f3cd215d384348fb18b4add2a66cdc8658..58c81496c6f62e6b31aee42944fdca470c5af9a6 100644
--- a/arch/arm/mach-iop33x/iq80332.c
+++ b/arch/arm/mach-iop33x/iq80332.c
@@ -96,7 +96,8 @@ static struct hw_pci iq80332_pci __initdata = {
 
 static int __init iq80332_pci_init(void)
 {
-	if (machine_is_iq80332())
+	if ((iop3xx_get_init_atu() == IOP3XX_INIT_ATU_ENABLE) &&
+		machine_is_iq80332())
 		pci_common_init(&iq80332_pci);
 
 	return 0;
diff --git a/arch/arm/plat-iop/pci.c b/arch/arm/plat-iop/pci.c
index b5f6ec35aafb59e2b9fd1597e615e7000a157769..e2744b7227c579a0abc8a461aeb20ec930e9b923 100644
--- a/arch/arm/plat-iop/pci.c
+++ b/arch/arm/plat-iop/pci.c
@@ -55,7 +55,7 @@ static u32 iop3xx_cfg_address(struct pci_bus *bus, int devfn, int where)
  * This routine checks the status of the last configuration cycle.  If an error
  * was detected it returns a 1, else it returns a 0.  The errors being checked
  * are parity, master abort, target abort (master and target).  These types of
- * errors occure during a config cycle where there is no device, like during
+ * errors occur during a config cycle where there is no device, like during
  * the discovery stage.
  */
 static int iop3xx_pci_status(void)
@@ -223,8 +223,111 @@ struct pci_bus *iop3xx_pci_scan_bus(int nr, struct pci_sys_data *sys)
 	return pci_scan_bus(sys->busnr, &iop3xx_ops, sys);
 }
 
+void __init iop3xx_atu_setup(void)
+{
+	/* BAR 0 ( Disabled ) */
+	*IOP3XX_IAUBAR0 = 0x0;
+	*IOP3XX_IABAR0  = 0x0;
+	*IOP3XX_IATVR0  = 0x0;
+	*IOP3XX_IALR0   = 0x0;
+
+	/* BAR 1 ( Disabled ) */
+	*IOP3XX_IAUBAR1 = 0x0;
+	*IOP3XX_IABAR1  = 0x0;
+	*IOP3XX_IALR1   = 0x0;
+
+	/* BAR 2 (1:1 mapping with Physical RAM) */
+	/* Set limit and enable */
+	*IOP3XX_IALR2 = ~((u32)IOP3XX_MAX_RAM_SIZE - 1) & ~0x1;
+	*IOP3XX_IAUBAR2 = 0x0;
+
+	/* Align the inbound bar with the base of memory */
+	*IOP3XX_IABAR2 = PHYS_OFFSET |
+			       PCI_BASE_ADDRESS_MEM_TYPE_64 |
+			       PCI_BASE_ADDRESS_MEM_PREFETCH;
+
+	*IOP3XX_IATVR2 = PHYS_OFFSET;
+
+	/* Outbound window 0 */
+	*IOP3XX_OMWTVR0 = IOP3XX_PCI_LOWER_MEM_PA;
+	*IOP3XX_OUMWTVR0 = 0;
+
+	/* Outbound window 1 */
+	*IOP3XX_OMWTVR1 = IOP3XX_PCI_LOWER_MEM_PA + IOP3XX_PCI_MEM_WINDOW_SIZE;
+	*IOP3XX_OUMWTVR1 = 0;
+
+	/* BAR 3 ( Disabled ) */
+	*IOP3XX_IAUBAR3 = 0x0;
+	*IOP3XX_IABAR3  = 0x0;
+	*IOP3XX_IATVR3  = 0x0;
+	*IOP3XX_IALR3   = 0x0;
+
+	/* Setup the I/O Bar
+	 */
+	*IOP3XX_OIOWTVR = IOP3XX_PCI_LOWER_IO_PA;;
+
+	/* Enable inbound and outbound cycles
+	 */
+	*IOP3XX_ATUCMD |= PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER |
+			       PCI_COMMAND_PARITY | PCI_COMMAND_SERR;
+	*IOP3XX_ATUCR |= IOP3XX_ATUCR_OUT_EN;
+}
+
+void __init iop3xx_atu_disable(void)
+{
+	*IOP3XX_ATUCMD = 0;
+	*IOP3XX_ATUCR = 0;
+
+	/* wait for cycles to quiesce */
+	while (*IOP3XX_PCSR & (IOP3XX_PCSR_OUT_Q_BUSY |
+				     IOP3XX_PCSR_IN_Q_BUSY))
+		cpu_relax();
+
+	/* BAR 0 ( Disabled ) */
+	*IOP3XX_IAUBAR0 = 0x0;
+	*IOP3XX_IABAR0  = 0x0;
+	*IOP3XX_IATVR0  = 0x0;
+	*IOP3XX_IALR0   = 0x0;
+
+	/* BAR 1 ( Disabled ) */
+	*IOP3XX_IAUBAR1 = 0x0;
+	*IOP3XX_IABAR1  = 0x0;
+	*IOP3XX_IALR1   = 0x0;
+
+	/* BAR 2 ( Disabled ) */
+	*IOP3XX_IAUBAR2 = 0x0;
+	*IOP3XX_IABAR2  = 0x0;
+	*IOP3XX_IATVR2  = 0x0;
+	*IOP3XX_IALR2   = 0x0;
+
+	/* BAR 3 ( Disabled ) */
+	*IOP3XX_IAUBAR3 = 0x0;
+	*IOP3XX_IABAR3  = 0x0;
+	*IOP3XX_IATVR3  = 0x0;
+	*IOP3XX_IALR3   = 0x0;
+
+	/* Clear the outbound windows */
+	*IOP3XX_OIOWTVR  = 0;
+
+	/* Outbound window 0 */
+	*IOP3XX_OMWTVR0 = 0;
+	*IOP3XX_OUMWTVR0 = 0;
+
+	/* Outbound window 1 */
+	*IOP3XX_OMWTVR1 = 0;
+	*IOP3XX_OUMWTVR1 = 0;
+}
+
+/* Flag to determine whether the ATU is initialized and the PCI bus scanned */
+int init_atu;
+
 void iop3xx_pci_preinit(void)
 {
+	if (iop3xx_get_init_atu() == IOP3XX_INIT_ATU_ENABLE) {
+		iop3xx_atu_disable();
+		iop3xx_atu_setup();
+	}
+
 	DBG("PCI:  Intel 803xx PCI init code.\n");
 	DBG("ATU: IOP3XX_ATUCMD=0x%04x\n", *IOP3XX_ATUCMD);
 	DBG("ATU: IOP3XX_OMWTVR0=0x%04x, IOP3XX_OIOWTVR=0x%04x\n",
@@ -245,3 +348,38 @@ void iop3xx_pci_preinit(void)
 
 	hook_fault_code(16+6, iop3xx_pci_abort, SIGBUS, "imprecise external abort");
 }
+
+/* allow init_atu to be user overridden */
+static int __init iop3xx_init_atu_setup(char *str)
+{
+	init_atu = IOP3XX_INIT_ATU_DEFAULT;
+	if (str) {
+		while (*str != '\0') {
+			switch (*str) {
+			case 'y':
+			case 'Y':
+				init_atu = IOP3XX_INIT_ATU_ENABLE;
+				break;
+			case 'n':
+			case 'N':
+				init_atu = IOP3XX_INIT_ATU_DISABLE;
+				break;
+			case ',':
+			case '=':
+				break;
+			default:
+				printk(KERN_DEBUG "\"%s\" malformed at "
+					    "character: \'%c\'",
+					    __FUNCTION__,
+					    *str);
+				*(str + 1) = '\0';
+			}
+			str++;
+		}
+	}
+
+	return 1;
+}
+
+__setup("iop3xx_init_atu", iop3xx_init_atu_setup);
+
diff --git a/include/asm-arm/arch-iop32x/iop32x.h b/include/asm-arm/arch-iop32x/iop32x.h
index 2e9469047eb14a0cc22dc4432e7bc0522337c92a..0d8af57221a12f8972af6ecc0bd498dac801a53e 100644
--- a/include/asm-arm/arch-iop32x/iop32x.h
+++ b/include/asm-arm/arch-iop32x/iop32x.h
@@ -24,5 +24,14 @@
 
 #include <asm/hardware/iop3xx.h>
 
+/* ATU Parameters
+ * set up a 1:1 bus to physical ram relationship
+ * w/ physical ram on top of pci in the memory map
+ */
+#define IOP32X_MAX_RAM_SIZE            0x40000000UL
+#define IOP3XX_MAX_RAM_SIZE            IOP32X_MAX_RAM_SIZE
+#define IOP3XX_PCI_LOWER_MEM_BA        0x80000000
+#define IOP32X_PCI_MEM_WINDOW_SIZE     0x04000000
+#define IOP3XX_PCI_MEM_WINDOW_SIZE     IOP32X_PCI_MEM_WINDOW_SIZE
 
 #endif
diff --git a/include/asm-arm/arch-iop32x/memory.h b/include/asm-arm/arch-iop32x/memory.h
index 764cd3f0d416b4b943fb07ae86fbfcfaf85dacfd..c51072af214efad2a7f9d7f759ebbefb251bb89e 100644
--- a/include/asm-arm/arch-iop32x/memory.h
+++ b/include/asm-arm/arch-iop32x/memory.h
@@ -19,8 +19,8 @@
  * bus_to_virt: Used to convert an address for DMA operations
  *		to an address that the kernel can use.
  */
-#define __virt_to_bus(x)	(((__virt_to_phys(x)) & ~(*IOP3XX_IATVR2)) | ((*IOP3XX_IABAR2) & 0xfffffff0))
-#define __bus_to_virt(x)	(__phys_to_virt(((x) & ~(*IOP3XX_IALR2)) | ( *IOP3XX_IATVR2)))
+#define __virt_to_bus(x)	(__virt_to_phys(x))
+#define __bus_to_virt(x)	(__phys_to_virt(x))
 
 
 #endif
diff --git a/include/asm-arm/arch-iop33x/iop33x.h b/include/asm-arm/arch-iop33x/iop33x.h
index 7ac6e93db5ff4a42369f0a1c0eb2d7a0ddf297a0..766985b9a723c6064f56c9df85f4d2d52958110e 100644
--- a/include/asm-arm/arch-iop33x/iop33x.h
+++ b/include/asm-arm/arch-iop33x/iop33x.h
@@ -29,5 +29,15 @@
 #define IOP33X_UART1_PHYS	(IOP3XX_PERIPHERAL_PHYS_BASE + 0x1740)
 #define IOP33X_UART1_VIRT	(IOP3XX_PERIPHERAL_VIRT_BASE + 0x1740)
 
+/* ATU Parameters
+ * set up a 1:1 bus to physical ram relationship
+ * w/ pci on top of physical ram in memory map
+ */
+#define IOP33X_MAX_RAM_SIZE		0x80000000UL
+#define IOP3XX_MAX_RAM_SIZE		IOP33X_MAX_RAM_SIZE
+#define IOP3XX_PCI_LOWER_MEM_BA	(PHYS_OFFSET + IOP33X_MAX_RAM_SIZE)
+#define IOP33X_PCI_MEM_WINDOW_SIZE	0x08000000
+#define IOP3XX_PCI_MEM_WINDOW_SIZE	IOP33X_PCI_MEM_WINDOW_SIZE
+
 
 #endif
diff --git a/include/asm-arm/arch-iop33x/memory.h b/include/asm-arm/arch-iop33x/memory.h
index 0d39139b241e543a93510a644a32ae6ba70bdae0..c8749127d6ab2a9ca322857281bf98e374d9ccd8 100644
--- a/include/asm-arm/arch-iop33x/memory.h
+++ b/include/asm-arm/arch-iop33x/memory.h
@@ -19,8 +19,8 @@
  * bus_to_virt: Used to convert an address for DMA operations
  *		to an address that the kernel can use.
  */
-#define __virt_to_bus(x)	(((__virt_to_phys(x)) & ~(*IOP3XX_IATVR2)) | ((*IOP3XX_IABAR2) & 0xfffffff0))
-#define __bus_to_virt(x)	(__phys_to_virt(((x) & ~(*IOP3XX_IALR2)) | ( *IOP3XX_IATVR2)))
+#define __virt_to_bus(x)	(__virt_to_phys(x))
+#define __bus_to_virt(x)	(__phys_to_virt(x))
 
 
 #endif
diff --git a/include/asm-arm/hardware/iop3xx.h b/include/asm-arm/hardware/iop3xx.h
index 15141a9caca8352a641117341caa042af3cedff2..ebbcd9be3fe55eac1a058a41a45c8f5353e730c7 100644
--- a/include/asm-arm/hardware/iop3xx.h
+++ b/include/asm-arm/hardware/iop3xx.h
@@ -28,6 +28,7 @@
 extern void gpio_line_config(int line, int direction);
 extern int  gpio_line_get(int line);
 extern void gpio_line_set(int line, int value);
+extern int init_atu;
 #endif
 
 
@@ -103,6 +104,21 @@ extern void gpio_line_set(int line, int value);
 #define IOP3XX_PCIXCMD		(volatile u16 *)IOP3XX_REG_ADDR(0x01e2)
 #define IOP3XX_PCIXSR		(volatile u32 *)IOP3XX_REG_ADDR(0x01e4)
 #define IOP3XX_PCIIRSR		(volatile u32 *)IOP3XX_REG_ADDR(0x01ec)
+#define IOP3XX_PCSR_OUT_Q_BUSY (1 << 15)
+#define IOP3XX_PCSR_IN_Q_BUSY	(1 << 14)
+#define IOP3XX_ATUCR_OUT_EN	(1 << 1)
+
+#define IOP3XX_INIT_ATU_DEFAULT 0
+#define IOP3XX_INIT_ATU_DISABLE -1
+#define IOP3XX_INIT_ATU_ENABLE	 1
+
+#ifdef CONFIG_IOP3XX_ATU
+#define iop3xx_get_init_atu(x) (init_atu == IOP3XX_INIT_ATU_DEFAULT ?\
+				IOP3XX_INIT_ATU_ENABLE : init_atu)
+#else
+#define iop3xx_get_init_atu(x) (init_atu == IOP3XX_INIT_ATU_DEFAULT ?\
+				IOP3XX_INIT_ATU_DISABLE : init_atu)
+#endif
 
 /* Messaging Unit  */
 #define IOP3XX_IMR0		(volatile u32 *)IOP3XX_REG_ADDR(0x0310)
@@ -253,14 +269,12 @@ extern void gpio_line_set(int line, int value);
 /*
  * IOP3XX I/O and Mem space regions for PCI autoconfiguration
  */
-#define IOP3XX_PCI_MEM_WINDOW_SIZE	0x04000000
-#define IOP3XX_PCI_LOWER_MEM_PA		0x80000000
-#define IOP3XX_PCI_LOWER_MEM_BA		(*IOP3XX_OMWTVR0)
+#define IOP3XX_PCI_LOWER_MEM_PA	0x80000000
 
 #define IOP3XX_PCI_IO_WINDOW_SIZE	0x00010000
 #define IOP3XX_PCI_LOWER_IO_PA		0x90000000
 #define IOP3XX_PCI_LOWER_IO_VA		0xfe000000
-#define IOP3XX_PCI_LOWER_IO_BA		(*IOP3XX_OIOWTVR)
+#define IOP3XX_PCI_LOWER_IO_BA		0x90000000
 #define IOP3XX_PCI_UPPER_IO_PA		(IOP3XX_PCI_LOWER_IO_PA +\
 					IOP3XX_PCI_IO_WINDOW_SIZE - 1)
 #define IOP3XX_PCI_UPPER_IO_VA		(IOP3XX_PCI_LOWER_IO_VA +\