ns16550: change to allow 32 bit access to registers

If CONFIG_SYS_NS16550_MEM32 is defined then 32 bit memory
mapped access will be used to read/write the uart registers.

This is especially useful for SoC devices that implement 16550
compatible uarts but that have peripheral access width constraints.
Signed-off-by: NDave Aldridge <fovsoft@gmail.com>

drivers/serial/ns16550.c

@@ -19,6 +19,12 @@
 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
 #define serial_out(x,y)	outb(x,(ulong)y)
 #define serial_in(y)	inb((ulong)y)
+#elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE > 0)
+#define serial_out(x,y) out_be32(y,x)
+#define serial_in(y) 	in_be32(y)
+#elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE < 0)
+#define serial_out(x,y) out_le32(y,x)
+#define serial_in(y) 	in_le32(y)
 #else
 #define serial_out(x,y) writeb(x,y)
 #define serial_in(y) 	readb(y)

include/ns16550.h

@@ -21,8 +21,12 @@
  * will not allocate storage for arrays of size 0
  */
 
+#include <linux/types.h>
+
 #if !defined(CONFIG_SYS_NS16550_REG_SIZE) || (CONFIG_SYS_NS16550_REG_SIZE == 0)
 #error "Please define NS16550 registers size."
+#elif defined(CONFIG_SYS_NS16550_MEM32)
+#define UART_REG(x) u32 x
 #elif (CONFIG_SYS_NS16550_REG_SIZE > 0)
 #define UART_REG(x)						   \
 	unsigned char prepad_##x[CONFIG_SYS_NS16550_REG_SIZE - 1]; \