[PATCH] Add support for word-length UART registers

UARTS on several Intel IXP2000 systems are connected in such a way that
they can only be addressed using full word accesses instead of bytes.
Following patch adds a UPIO_MEM32 io-type to identify these UARTs.
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/serial/8250.c

@@ -188,6 +188,9 @@ static _INLINE_ unsigned int serial_in(struct uart_8250_port *up, int offset)
 	case UPIO_MEM:
 		return readb(up->port.membase + offset);
 
+	case UPIO_MEM32:
+		return readl(up->port.membase + offset);
+
 	default:
 		return inb(up->port.iobase + offset);
 	}
@@ -208,6 +211,10 @@ serial_out(struct uart_8250_port *up, int offset, int value)
 		writeb(value, up->port.membase + offset);
 		break;
 
+	case UPIO_MEM32:
+		writel(value, up->port.membase + offset);
+		break;
+
 	default:
 		outb(value, up->port.iobase + offset);
 	}

drivers/serial/serial_core.c

@@ -1978,6 +1978,7 @@ uart_report_port(struct uart_driver *drv, struct uart_port *port)
 		printk("I/O 0x%x offset 0x%x", port->iobase, port->hub6);
 		break;
 	case UPIO_MEM:
+	case UPIO_MEM32:
 		printk("MMIO 0x%lx", port->mapbase);
 		break;
 	}

include/linux/serial_core.h

@@ -176,6 +176,7 @@ struct uart_port {
 #define UPIO_PORT		(0)
 #define UPIO_HUB6		(1)
 #define UPIO_MEM		(2)
+#define UPIO_MEM32		(3)
 
 	unsigned int		read_status_mask;	/* driver specific */
 	unsigned int		ignore_status_mask;	/* driver specific */