Add low-level debug support for MPS2, so that earlyprintk can be enabled
for debugging early boot issues.

Signed-off-by: Vladimir Murzin <vladimir.mur...@arm.com>
---
 arch/arm/Kconfig.debug        |   12 +++++++++++-
 arch/arm/include/debug/mps2.S |   27 +++++++++++++++++++++++++++
 2 files changed, 38 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm/include/debug/mps2.S

diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
index c6b6175..fcd2e15 100644
--- a/arch/arm/Kconfig.debug
+++ b/arch/arm/Kconfig.debug
@@ -485,6 +485,13 @@ choice
                  Say Y here if you want kernel low-level debugging support
                  on MMP UART3.
 
+       config DEBUG_MPS2_UART
+               bool "Kernel low-level debugging message via MPS2 UART0"
+               depends on ARCH_MPS2
+               help
+                 Say Y here if you want kernel low-level debugging support
+                 on MPS2 based platforms.
+
        config DEBUG_MVEBU_UART0
                bool "Kernel low-level debugging messages via MVEBU UART0 (old 
bootloaders)"
                depends on ARCH_MVEBU
@@ -1415,6 +1422,7 @@ config DEBUG_LL_INCLUDE
        default "debug/zynq.S" if DEBUG_ZYNQ_UART0 || DEBUG_ZYNQ_UART1
        default "debug/bcm63xx.S" if DEBUG_BCM63XX_UART
        default "debug/digicolor.S" if DEBUG_DIGICOLOR_UA0
+       default "debug/mps2.S" if DEBUG_MPS2_UART
        default "mach/debug-macro.S"
 
 # Compatibility options for PL01x
@@ -1463,6 +1471,7 @@ config DEBUG_UART_PHYS
        default 0x20201000 if DEBUG_BCM2835
        default 0x3f201000 if DEBUG_BCM2836
        default 0x3e000000 if DEBUG_BCM_KONA_UART
+       default 0x40004000 if DEBUG_MPS2_UART
        default 0x4000e400 if DEBUG_LL_UART_EFM32
        default 0x40081000 if DEBUG_LPC18XX_UART0
        default 0x40090000 if DEBUG_LPC32XX
@@ -1539,7 +1548,8 @@ config DEBUG_UART_PHYS
                DEBUG_S3C64XX_UART || \
                DEBUG_BCM63XX_UART || DEBUG_ASM9260_UART || \
                DEBUG_SIRFSOC_UART || DEBUG_DIGICOLOR_UA0 || \
-               DEBUG_AT91_UART
+               DEBUG_AT91_UART || \
+               DEBUG_MPS2_UART
 
 config DEBUG_UART_VIRT
        hex "Virtual base address of debug UART"
diff --git a/arch/arm/include/debug/mps2.S b/arch/arm/include/debug/mps2.S
new file mode 100644
index 0000000..0ced0ce
--- /dev/null
+++ b/arch/arm/include/debug/mps2.S
@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2015 ARM Limited
+ *
+ * Author: Vladimir Murzin <vladimir.mur...@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+       .macro  addruart, rp, tmp1, tmp2
+       ldr     \rp, =CONFIG_DEBUG_UART_PHYS
+       .endm
+
+       .macro  senduart, rd, rx
+       strb    \rd, [\rx]              @ Data Register
+       .endm
+
+       .macro  busyuart, rd, rx
+1001:  ldrb    \rd, [\rx, #0x4]        @ State Register
+       tst     \rd, #1                 @ busy
+       bne     1001b                   @ wait until transmit done
+       .endm
+
+       .macro  waituart,rd,rx
+       .endm
-- 
1.7.9.5

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