MIPS: boot: Fixes for compressed/uart-16550.c

Fix uart-16550.c for adding XLR/XLP support, changes are:
* Make register read/write use volatile pointers
* Support 32 bit IO read/write
* Increase timeout in waiting for UART LSR
Signed-off-by: NJayachandran C <jchandra@broadcom.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5416/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

arch/mips/boot/compressed/uart-16550.c

@@ -23,23 +23,27 @@
 #define PORT(offset) (UART0_BASE + (4 * offset))
 #endif
 
+#ifndef IOTYPE
+#define IOTYPE char
+#endif
+
 #ifndef PORT
 #error please define the serial port address for your own machine
 #endif
 
 static inline unsigned int serial_in(int offset)
 {
-	return *((char *)PORT(offset));
+	return *((volatile IOTYPE *)PORT(offset)) & 0xFF;
 }
 
 static inline void serial_out(int offset, int value)
 {
-	*((char *)PORT(offset)) = value;
+	*((volatile IOTYPE *)PORT(offset)) = value & 0xFF;
 }
 
 void putc(char c)
 {
-	int timeout = 1024;
+	int timeout = 1000000;
 
 	while (((serial_in(UART_LSR) & UART_LSR_THRE) == 0) && (timeout-- > 0))
 		;