diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 630deb7dd344..dd63aedb8675 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -474,16 +474,10 @@ static void set_io_from_upio(struct uart_port *p)
 static void
 serial_port_out_sync(struct uart_port *p, int offset, int value)
 {
-	switch (p->iotype) {
-	case UPIO_MEM:
-	case UPIO_MEM16:
-	case UPIO_MEM32:
-	case UPIO_MEM32BE:
-	case UPIO_AU:
+	if (uart_iotype_mmio(p->iotype)) {
 		p->serial_out(p, offset, value);
 		p->serial_in(p, UART_LCR);	/* safe, no side-effects */
-		break;
-	default:
+	} else {
 		p->serial_out(p, offset, value);
 	}
 }
@@ -2885,13 +2879,7 @@ static int serial8250_request_std_resource(struct uart_8250_port *up)
 	unsigned int size = serial8250_port_size(up);
 	struct uart_port *port = &up->port;
 
-	switch (port->iotype) {
-	case UPIO_AU:
-	case UPIO_TSI:
-	case UPIO_MEM32:
-	case UPIO_MEM32BE:
-	case UPIO_MEM16:
-	case UPIO_MEM:
+	if (uart_iotype_mmio(port->iotype)) {
 		if (!port->mapbase)
 			return -EINVAL;
 
@@ -2905,14 +2893,9 @@ static int serial8250_request_std_resource(struct uart_8250_port *up)
 				return -ENOMEM;
 			}
 		}
-		return 0;
-	case UPIO_HUB6:
-	case UPIO_PORT:
+	} else if (uart_iotype_io(port->iotype)) {
 		if (!request_region(port->iobase, size, "serial"))
 			return -EBUSY;
-		return 0;
-	case UPIO_UNKNOWN:
-		break;
 	}
 
 	return 0;
@@ -2923,15 +2906,9 @@ static void serial8250_release_std_resource(struct uart_8250_port *up)
 	unsigned int size = serial8250_port_size(up);
 	struct uart_port *port = &up->port;
 
-	switch (port->iotype) {
-	case UPIO_AU:
-	case UPIO_TSI:
-	case UPIO_MEM32:
-	case UPIO_MEM32BE:
-	case UPIO_MEM16:
-	case UPIO_MEM:
+	if (uart_iotype_mmio(port->iotype)) {
 		if (!port->mapbase)
-			break;
+			return;
 
 		if (port->flags & UPF_IOREMAP) {
 			iounmap(port->membase);
@@ -2939,14 +2916,8 @@ static void serial8250_release_std_resource(struct uart_8250_port *up)
 		}
 
 		release_mem_region(port->mapbase, size);
-		break;
-
-	case UPIO_HUB6:
-	case UPIO_PORT:
+	} else if (uart_iotype_io(port->iotype)) {
 		release_region(port->iobase, size);
-		break;
-	case UPIO_UNKNOWN:
-		break;
 	}
 }