davinci: support different UART bases for zImage uncompress

The davinci pre-kernel boot code assumes that all platforms use the
same UART base address for the console.  That assumption is not longer
valid with some newer SoCs so determine the console UART base address
from the machine number passed in from bootloader.

Signed-off-by: Mark A. Greer <mgreer@mvista.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

arch/arm/mach-davinci/include/mach/uncompress.h

@@ -13,11 +13,24 @@
 #include <linux/serial_reg.h>
 #include <mach/serial.h>
 
+#include <asm/mach-types.h>
+
+extern unsigned int __machine_arch_type;
+
+static u32 *uart;
+
+static u32 *get_uart_base(void)
+{
+	/* Add logic here for new platforms, using __macine_arch_type */
+	return (u32 *)DAVINCI_UART0_BASE;
+}
+
 /* PORT_16C550A, in polled non-fifo mode */
 
 static void putc(char c)
 {
-	volatile u32 *uart = (volatile void *) DAVINCI_UART0_BASE;
+	if (!uart)
+		uart = get_uart_base();
 
 	while (!(uart[UART_LSR] & UART_LSR_THRE))
 		barrier();
@@ -26,7 +39,9 @@ static void putc(char c)
 
 static inline void flush(void)
 {
-	volatile u32 *uart = (volatile void *) DAVINCI_UART0_BASE;
+	if (!uart)
+		uart = get_uart_base();
+
 	while (!(uart[UART_LSR] & UART_LSR_THRE))
 		barrier();
 }