[PATCH] ARM: 2745/1: Fix IXP4xx debug macros

Patch from Deepak Saxena

Current IXP4xx debug macros do not work in the small window between
the MMU being enabled and the call to map_io() b/c the standard
peripheral mapping is not properly setup for use with the low-level
debug code. This patch creates a new section-aligned mapping for the
UART specifically for use with the debug macros.

Signed-off-by: Deepak Saxena
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

3 files changed, 19 insertions, 0 deletions

diff --git a/arch/arm/mach-ixp4xx/common.c b/arch/arm/mach-ixp4xx/common.c
index 267ba02d77dc..f39e8408488f 100644
--- a/arch/arm/mach-ixp4xx/common.c
+++ b/arch/arm/mach-ixp4xx/common.c
@@ -141,7 +141,15 @@ static struct map_desc ixp4xx_io_desc[] __initdata = {
                 .physical       = IXP4XX_PCI_CFG_BASE_PHYS,
                 .length         = IXP4XX_PCI_CFG_REGION_SIZE,
                 .type           = MT_DEVICE
+        },
+#ifdef CONFIG_DEBUG_LL
+        {       /* Debug UART mapping */
+                .virtual        = IXP4XX_DEBUG_UART_BASE_VIRT,
+                .physical       = IXP4XX_DEBUG_UART_BASE_PHYS,
+                .length         = IXP4XX_DEBUG_UART_REGION_SIZE,
+                .type           = MT_DEVICE
         }
+#endif
 };
 
 void __init ixp4xx_map_io(void)
diff --git a/include/asm-arm/arch-ixp4xx/debug-macro.S b/include/asm-arm/arch-ixp4xx/debug-macro.S
index 4499ae8e4b44..45a6c6cc29d5 100644
--- a/include/asm-arm/arch-ixp4xx/debug-macro.S
+++ b/include/asm-arm/arch-ixp4xx/debug-macro.S
@@ -14,6 +14,7 @@
                 mrc     p15, 0, \rx, c1, c0
                 tst     \rx, #1                 @ MMU enabled?
                 moveq   \rx, #0xc8000000
+                orrne   \rx, \rx, #0x00b00000
                 movne   \rx, #0xff000000
                 add     \rx,\rx,#3              @ Uart regs are at off set of 3 if
                                                 @ byte writes used - Big Endian.
diff --git a/include/asm-arm/arch-ixp4xx/ixp4xx-regs.h b/include/asm-arm/arch-ixp4xx/ixp4xx-regs.h
index 8eeb1db6309d..004696a95bdb 100644
--- a/include/asm-arm/arch-ixp4xx/ixp4xx-regs.h
+++ b/include/asm-arm/arch-ixp4xx/ixp4xx-regs.h
@@ -69,6 +69,16 @@
 #define IXP4XX_PERIPHERAL_BASE_VIRT     (0xFFBF2000)
 #define IXP4XX_PERIPHERAL_REGION_SIZE   (0x0000C000)
 
+/*
+ * Debug UART
+ *
+ * This is basically a remap of UART1 into a region that is section
+ * aligned so that it * can be used with the low-level debug code.
+ */
+#define IXP4XX_DEBUG_UART_BASE_PHYS     (0xC8000000)
+#define IXP4XX_DEBUG_UART_BASE_VIRT     (0xffb00000)
+#define IXP4XX_DEBUG_UART_REGION_SIZE   (0x00001000)
+
 #define IXP4XX_EXP_CS0_OFFSET   0x00
 #define IXP4XX_EXP_CS1_OFFSET   0x04
 #define IXP4XX_EXP_CS2_OFFSET   0x08