[PATCH v3 07/10] ARM: mps2: add low-level debug support

Vladimir Murzin
2016-02-16T10:08:12Z

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

Signed-off-by: Vladimir Murzin <vladimir.murzin@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.murzin@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