[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>

2 files changed, 29 insertions, 6 deletions

diff --git a/arch/arm/mach-ep93xx/Kconfig b/arch/arm/mach-ep93xx/Kconfig
index ea8549bfbef2..5a1b8c05c958 100644
--- a/arch/arm/mach-ep93xx/Kconfig
+++ b/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
diff --git a/arch/arm/mach-ep93xx/include/mach/uncompress.h b/arch/arm/mach-ep93xx/include/mach/uncompress.h
index 1fd2f17de325..16026c2b1c8c 100644
--- a/arch/arm/mach-ep93xx/include/mach/uncompress.h
+++ b/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)