serial: core: Add big-endian iotype

Since most drivers interpret UPIO_MEM32 to mean "little-endian" and use
readl/writel to access the registers, add a parallel UPIO_MEM32BE to
request the use of big-endian MMIO accessors (ioread32be/iowrite32be).

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/serial_core.c

@@ -2153,6 +2153,7 @@ uart_report_port(struct uart_driver *drv, struct uart_port *port)
 		break;
 	case UPIO_MEM:
 	case UPIO_MEM32:
+	case UPIO_MEM32BE:
 	case UPIO_AU:
 	case UPIO_TSI:
 		snprintf(address, sizeof(address),
@@ -2796,6 +2797,7 @@ int uart_match_port(struct uart_port *port1, struct uart_port *port2)
 		       (port1->hub6   == port2->hub6);
 	case UPIO_MEM:
 	case UPIO_MEM32:
+	case UPIO_MEM32BE:
 	case UPIO_AU:
 	case UPIO_TSI:
 		return (port1->mapbase == port2->mapbase);

include/linux/serial_core.h

@@ -142,12 +142,13 @@ struct uart_port {
 	unsigned char		iotype;			/* io access style */
 	unsigned char		unused1;
 
-#define UPIO_PORT		(0)
-#define UPIO_HUB6		(1)
-#define UPIO_MEM		(2)
-#define UPIO_MEM32		(3)
-#define UPIO_AU			(4)			/* Au1x00 and RT288x type IO */
-#define UPIO_TSI		(5)			/* Tsi108/109 type IO */
+#define UPIO_PORT		(0)			/* 8b I/O port access */
+#define UPIO_HUB6		(1)			/* Hub6 ISA card */
+#define UPIO_MEM		(2)			/* 8b MMIO access */
+#define UPIO_MEM32		(3)			/* 32b little endian */
+#define UPIO_MEM32BE		(4)			/* 32b big endian */
+#define UPIO_AU			(5)			/* Au1x00 and RT288x type IO */
+#define UPIO_TSI		(6)			/* Tsi108/109 type IO */
 
 	unsigned int		read_status_mask;	/* driver specific */
 	unsigned int		ignore_status_mask;	/* driver specific */