--- a/arch/arm/mach-ixp4xx/cambria-setup.c
+++ b/arch/arm/mach-ixp4xx/cambria-setup.c
@@ -34,6 +34,7 @@
 #include <asm/mach/arch.h>
 #include <asm/mach/flash.h>
 #include <asm/setup.h>
+#include <linux/irq.h>
 
 struct cambria_board_info {
 	unsigned char	*model;
@@ -127,6 +128,45 @@ static struct platform_device cambria_ua
 	.resource	= &cambria_uart_resource,
 };
 
+static struct resource cambria_optional_uart_resources[] = {
+	{
+		.start	= 0x52000000,
+		.end	= 0x52000fff,
+		.flags	= IORESOURCE_MEM
+	},
+	{
+		.start	= 0x53000000,
+		.end	= 0x53000fff,
+		.flags	= IORESOURCE_MEM
+	}
+};
+
+static struct plat_serial8250_port cambria_optional_uart_data[] = {
+	{
+		.flags		= UPF_BOOT_AUTOCONF,
+		.iotype		= UPIO_MEM_DELAY,
+		.regshift	= 0,
+		.uartclk	= 1843200,
+		.rw_delay	= 2,
+	},
+	{
+		.flags		= UPF_BOOT_AUTOCONF,
+		.iotype		= UPIO_MEM_DELAY,
+		.regshift	= 0,
+		.uartclk	= 1843200,
+		.rw_delay	= 2,
+	},
+  { },
+};
+
+static struct platform_device cambria_optional_uart = {
+	.name		= "serial8250",
+	.id		= PLAT8250_DEV_PLATFORM1,
+	.dev.platform_data	= cambria_optional_uart_data,
+	.num_resources	= 2,
+	.resource	= cambria_optional_uart_resources,
+};
+
 static struct resource cambria_pata_resources[] = {
 	{
 		.flags	= IORESOURCE_MEM
@@ -283,6 +323,19 @@ static void __init cambria_gw23xx_setup(
 
 static void __init cambria_gw2350_setup(void)
 {
+	*IXP4XX_EXP_CS2 = 0xBFFF3C43;
+	set_irq_type(IRQ_IXP4XX_GPIO3, IRQ_TYPE_EDGE_RISING);
+	cambria_optional_uart_data[0].mapbase	= 0x52FF0000;
+	cambria_optional_uart_data[0].membase	= (void __iomem *)ioremap(0x52FF0000, 0x0fff);
+	cambria_optional_uart_data[0].irq		= IRQ_IXP4XX_GPIO3;
+
+	*IXP4XX_EXP_CS3 = 0xBFFF3C43;
+	set_irq_type(IRQ_IXP4XX_GPIO4, IRQ_TYPE_EDGE_RISING);
+	cambria_optional_uart_data[1].mapbase	= 0x53FF0000;
+	cambria_optional_uart_data[1].membase	= (void __iomem *)ioremap(0x53FF0000, 0x0fff);
+	cambria_optional_uart_data[1].irq		= IRQ_IXP4XX_GPIO4;
+
+	platform_device_register(&cambria_optional_uart);
 	platform_device_register(&cambria_npec_device);
 	platform_device_register(&cambria_npea_device);
 
@@ -294,6 +347,19 @@ static void __init cambria_gw2350_setup(
 
 static void __init cambria_gw2358_setup(void)
 {
+	*IXP4XX_EXP_CS3 = 0xBFFF3C43;
+	set_irq_type(IRQ_IXP4XX_GPIO3, IRQ_TYPE_EDGE_RISING);
+	cambria_optional_uart_data[0].mapbase	= 0x53FC0000;
+	cambria_optional_uart_data[0].membase	= (void __iomem *)ioremap(0x53FC0000, 0x0fff);
+	cambria_optional_uart_data[0].irq		= IRQ_IXP4XX_GPIO3;
+
+	set_irq_type(IRQ_IXP4XX_GPIO4, IRQ_TYPE_EDGE_RISING);
+	cambria_optional_uart_data[1].mapbase	= 0x53F80000;
+	cambria_optional_uart_data[1].membase	= (void __iomem *)ioremap(0x53F80000, 0x0fff);
+	cambria_optional_uart_data[1].irq		= IRQ_IXP4XX_GPIO4;
+
+	platform_device_register(&cambria_optional_uart);
+
 	platform_device_register(&cambria_npec_device);
 	platform_device_register(&cambria_npea_device);
 
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -27,6 +27,7 @@ struct plat_serial8250_port {
 	void            *private_data;
 	unsigned char	regshift;	/* register shift */
 	unsigned char	iotype;		/* UPIO_* */
+	unsigned int rw_delay;	/* udelay for slower busses IXP4XX Expansion Bus */
 	unsigned char	hub6;
 	upf_t		flags;		/* UPF_* flags */
 	unsigned int	type;		/* If UPF_FIXED_TYPE */
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -288,6 +288,7 @@ struct uart_port {
 #define UPIO_TSI		(5)			/* Tsi108/109 type IO */
 #define UPIO_DWAPB		(6)			/* DesignWare APB UART */
 #define UPIO_RM9000		(7)			/* RM9000 type IO */
+#define UPIO_MEM_DELAY	(8)
 
 	unsigned int		read_status_mask;	/* driver specific */
 	unsigned int		ignore_status_mask;	/* driver specific */
@@ -330,6 +331,7 @@ struct uart_port {
 
 	unsigned int		mctrl;			/* current modem ctrl settings */
 	unsigned int		timeout;		/* character-based timeout */
+	unsigned int		rw_delay;		/* udelay for slow busses, IXP4XX Expansion Bus */
 	unsigned int		type;			/* port type */
 	const struct uart_ops	*ops;
 	unsigned int		custom_divisor;
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -409,6 +409,20 @@ static void mem_serial_out(struct uart_p
 	writeb(value, p->membase + offset);
 }
 
+static unsigned int memdelay_serial_in(struct uart_port *p, int offset)
+{
+	struct uart_8250_port *up = (struct uart_8250_port *)p;
+	udelay(up->port.rw_delay);
+	return mem_serial_in(p, offset);
+}
+
+static void memdelay_serial_out(struct uart_port *p, int offset, int value)
+{
+	struct uart_8250_port *up = (struct uart_8250_port *)p;
+	udelay(up->port.rw_delay);
+	mem_serial_out(p, offset, value);
+}
+
 static void mem32_serial_out(struct uart_port *p, int offset, int value)
 {
 	offset = map_8250_out_reg(p, offset) << p->regshift;
@@ -502,6 +516,11 @@ static void set_io_from_upio(struct uart
 		p->serial_out = mem32_serial_out;
 		break;
 
+	case UPIO_MEM_DELAY:
+		p->serial_in = memdelay_serial_in;
+		p->serial_out = memdelay_serial_out;
+		break;
+
 #ifdef CONFIG_SERIAL_8250_AU1X00
 	case UPIO_AU:
 		p->serial_in = au_serial_in;
@@ -534,6 +553,7 @@ serial_out_sync(struct uart_8250_port *u
 	switch (p->iotype) {
 	case UPIO_MEM:
 	case UPIO_MEM32:
+	case UPIO_MEM_DELAY:
 #ifdef CONFIG_SERIAL_8250_AU1X00
 	case UPIO_AU:
 #endif
@@ -2450,6 +2470,7 @@ static int serial8250_request_std_resour
 	case UPIO_MEM32:
 	case UPIO_MEM:
 	case UPIO_DWAPB:
+	case UPIO_MEM_DELAY:
 		if (!up->port.mapbase)
 			break;
 
@@ -2487,6 +2508,7 @@ static void serial8250_release_std_resou
 	case UPIO_MEM32:
 	case UPIO_MEM:
 	case UPIO_DWAPB:
+	case UPIO_MEM_DELAY:
 		if (!up->port.mapbase)
 			break;
 
@@ -2964,6 +2986,7 @@ static int __devinit serial8250_probe(st
 		port.serial_in		= p->serial_in;
 		port.serial_out		= p->serial_out;
 		port.dev		= &dev->dev;
+		port.rw_delay		= p->rw_delay;
 		port.irqflags		|= irqflag;
 		ret = serial8250_register_port(&port);
 		if (ret < 0) {
@@ -3113,6 +3136,7 @@ int serial8250_register_port(struct uart
 		uart->port.iotype       = port->iotype;
 		uart->port.flags        = port->flags | UPF_BOOT_AUTOCONF;
 		uart->port.mapbase      = port->mapbase;
+		uart->port.rw_delay			= port->rw_delay;
 		uart->port.private_data = port->private_data;
 		if (port->dev)
 			uart->port.dev = port->dev;
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -2144,6 +2144,7 @@ uart_report_port(struct uart_driver *drv
 		snprintf(address, sizeof(address),
 			 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
 		break;
+	case UPIO_MEM_DELAY:
 	case UPIO_MEM:
 	case UPIO_MEM32:
 	case UPIO_AU:
@@ -2557,6 +2558,7 @@ int uart_match_port(struct uart_port *po
 	case UPIO_HUB6:
 		return (port1->iobase == port2->iobase) &&
 		       (port1->hub6   == port2->hub6);
+	case UPIO_MEM_DELAY:
 	case UPIO_MEM:
 	case UPIO_MEM32:
 	case UPIO_AU:
