ARM: vexpress: Motherboard RS1 memory map support

This patch adds support for RS1 memory map based Versatile Express
motherboard.

Signed-off-by: Pawel Moll <pawel.moll@arm.com>

1 files changed, 21 insertions, 1 deletions

diff --git a/arch/arm/mach-vexpress/include/mach/uncompress.h b/arch/arm/mach-vexpress/include/mach/uncompress.h
index 7972c5748d0..7dab5596b86 100644
--- a/arch/arm/mach-vexpress/include/mach/uncompress.h
+++ b/arch/arm/mach-vexpress/include/mach/uncompress.h
@@ -22,7 +22,27 @@
 #define AMBA_UART_CR(base)      (*(volatile unsigned char *)((base) + 0x30))
 #define AMBA_UART_FR(base)      (*(volatile unsigned char *)((base) + 0x18))
 
-#define get_uart_base() (0x10000000 + 0x00009000)
+#define UART_BASE       0x10009000
+#define UART_BASE_RS1   0x1c090000
+
+static unsigned long get_uart_base(void)
+{
+        unsigned long mpcore_periph;
+
+        /*
+         * Make an educated guess regarding the memory map:
+         * - the original A9 core tile, which has MPCore peripherals
+         *   located at 0x1e000000, should use UART at 0x10009000
+         * - all other (RS1 complaint) tiles use UART mapped
+         *   at 0x1c090000
+         */
+        asm("mrc p15, 4, %0, c15, c0, 0" : "=r" (mpcore_periph));
+
+        if (mpcore_periph == 0x1e000000)
+                return UART_BASE;
+        else
+                return UART_BASE_RS1;
+}
 
 /*
  * This does not append a newline