[ARM] 5276/1: ep93xx: allow selecting UART for early kernel messages

Currently on the EP93xx platform early kernel messages go to UART1.
Since this UART is the only one that has modem control signals it
might be used for another purpose and it is undesirable for those
messages to appear. This patch allows one of the other UARTs to be
selected in the kernel configuration. It is assumed that the
bootloader has configured and initialized the UART since this was the
previous assumption.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-ep93xx/Kconfig

@@ -88,6 +88,20 @@ config MACH_TS72XX
 	  Say 'Y' here if you want your kernel to support the
 	  Technologic Systems TS-72xx board.
 
+choice
+	prompt "Select a UART for early kernel messages"
+
+config EP93XX_EARLY_UART1
+	bool "UART1"
+
+config EP93XX_EARLY_UART2
+	bool "UART2"
+
+config EP93XX_EARLY_UART3
+	bool "UART3"
+
+endchoice
+
 endmenu
 
 endif

arch/arm/mach-ep93xx/include/mach/uncompress.h

@@ -31,10 +31,19 @@ static void __raw_writel(unsigned int value, unsigned int ptr)
 	*((volatile unsigned int *)ptr) = value;
 }
 
-
-#define PHYS_UART1_DATA		0x808c0000
-#define PHYS_UART1_FLAG		0x808c0018
-#define UART1_FLAG_TXFF		0x20
+#if defined(CONFIG_EP93XX_EARLY_UART1)
+#define UART_BASE		EP93XX_UART1_PHYS_BASE
+#elif defined(CONFIG_EP93XX_EARLY_UART2)
+#define UART_BASE		EP93XX_UART2_PHYS_BASE
+#elif defined(CONFIG_EP93XX_EARLY_UART3)
+#define UART_BASE		EP93XX_UART3_PHYS_BASE
+#else
+#define UART_BASE		EP93XX_UART1_PHYS_BASE
+#endif
+
+#define PHYS_UART_DATA		(UART_BASE + 0x00)
+#define PHYS_UART_FLAG		(UART_BASE + 0x18)
+#define UART_FLAG_TXFF		0x20
 
 static inline void putc(int c)
 {
@@ -42,11 +51,11 @@ static inline void putc(int c)
 
 	for (i = 0; i < 1000; i++) {
 		/* Transmit fifo not full?  */
-		if (!(__raw_readb(PHYS_UART1_FLAG) & UART1_FLAG_TXFF))
+		if (!(__raw_readb(PHYS_UART_FLAG) & UART_FLAG_TXFF))
 			break;
 	}
 
-	__raw_writeb(c, PHYS_UART1_DATA);
+	__raw_writeb(c, PHYS_UART_DATA);
 }
 
 static inline void flush(void)